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INCORPORATED BY REFERENCE
The entire disclosure of Japanese Patent Application No. 2010-052823, filed Mar. 10, 2010 is expressly incorporated by reference herein.
BACKGROUND
1. Technical Field
The present invention relates to printing control apparatuses and printing control methods.
2. Related Art
Some image forming apparatuses, such as printers, copy machines, and so on, have layout printing functions for laying out multiple pages on a single sheet and printing those pages. In such layout printing, for example, A4-size originals are shrunk and multiple pages (for example, two pages, four pages, or the like) are printed onto a single A4 sheet. Such layout printing conserves paper, and is being widely used in today's climate of increased awareness of environmental issues.
JP-A-2008-257563, for example, discloses a printer driver that, when carrying out layout printing of document data in which different paper sizes are intermixed, carries out the layout according to the paper size and executes printing.
However, because the layout printing settings are carried out according to the paper size, the printing is executed using an uniform layout that has been set for all of the data, even in the case where text, graphics, and the like are intermixed throughout pages of the same paper size. Accordingly, pages that include small graphics, pictures, or the like are also laid out and printed, and because the graphics, pictures, or the like are shrunk, it is difficult to see the details in those graphics, pictures, or the like.
SUMMARY
An advantage of some aspects of the invention is to make it easy to set layout printing on a page-by-page basis. Having been conceived in order to solve at least some of the aforementioned problems, the invention can be implemented as the following aspects or application examples.
First Application Example
A printing control apparatus according to a first application example of the invention includes: an accepting unit that accepts a setting regarding layout printing for laying out multiple document pages in order on a sheet-by-sheet basis; a selection unit that, in the case where the layout printing setting has been accepted by the accepting unit, displays graphic images of the multiple document pages and allows a specific page for which layout printing is not to be carried out to be selected from among the graphic images; a layout processing unit that does not perform the layout for the specific page selected through the selection unit and does perform the layout for the document pages aside from the specific page; and a print data generation unit that generates print data of the multiple document pages based on a result of the processing performed by the layout processing unit.
According to this configuration, in the case where print data for layout printing is generated, the printing control apparatus displays the graphic images of the multiple document pages, allows the selection of a specific page to which the layout printing is not to be applied from among the displayed graphic images, and carries out settings so that the layout is not carried out on the selected specific page but is carried out on the document pages aside from the specific page. Accordingly, because the specific page to which the layout printing is not to be applied can be selected while visually confirming the graphic images of the multiple document pages, it is easy to carry out layout printing settings on a page-by-page basis.
Second Application Example
In the printing control apparatus according to the stated first application example, in the case where the multiple document pages include a page of a size that differs from the size of the sheet, the selection unit further allows a selection of whether or not to fit the size of the page to the size of the sheet, and the apparatus further includes a scaling processing unit that fits the size of the page to the size of the sheet by enlarging or shrinking the page based on a result selected through the selection unit.
According to this configuration, in the case where a page of a different size than the size of the sheet is included in the multiple document pages, the size of the page can be fit to the size of the sheet as necessary by enlarging or shrinking the page.
Third Application Example
In the printing control apparatus according to the above stated application examples, it is preferable that the selection unit classifies the graphic images into groups based on attributes of the graphic images and allows the selection of a group created through the classification.
Fourth Application Example
A printing control method according to a fourth application example of the invention includes: accepting a setting regarding layout printing for laying out multiple document pages in order on a sheet-by-sheet basis; allowing, in the case where the layout printing setting has been accepted in the accepting, a specific page for which layout printing is not to be carried out to be selected from among the graphic images by displaying graphic images of the multiple documents pages; performing the layout for the document pages aside from the specific page, not performing the layout for the specific page selected in the selecting; and generating print data of the multiple document pages based on a result of the processing performed in the layout performing.
According to this method, in the case where print data for layout printing is generated, the graphic images of the multiple document pages are displayed respectively, the selection of a specific page to which the layout printing is not to be applied is allowed from among the displayed graphic images, and settings are carried out so that the layout is not carried out on the selected specific page but is carried out on the document pages aside from the specific page. Accordingly, because the specific page to which the layout printing is not to be applied can be selected while visually confirming the graphic images of the multiple document pages, it is easy to carry out layout printing settings on a page-by-page basis.
Fifth Application Example
A printing control apparatus according to a fifth application example of the invention includes: an accepting unit that accepts a setting regarding layout printing for laying out multiple document pages in order on a sheet-by-sheet basis; a layout processing unit that, in the case where the layout printing setting has been accepted by the accepting unit, determines whether or not to perform the layout on the document pages based on attribute information of the document pages, and performs the layout on the document pages based on a result of the determination; and a print data generation unit that generates print data of the multiple document pages based on a result of the processing performed by the layout processing unit.
According to this configuration, in the case where print data for layout printing is generated, the printing control apparatus determines whether or not to carry out the layout on the document pages based on attribute information of the document pages, and carries out the layout on the document pages based on the result of the determination. Accordingly, the layout printing settings for the document pages can be carried out easily on a page-by-page basis.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
FIG. 1 is a diagram illustrating the overall configuration of a computer in which a printer driver according to an embodiment of the invention has been installed.
FIG. 2 is a diagram illustrating the module configuration of a printer driver according to an embodiment of the invention.
FIG. 3 is a diagram illustrating a printing conditions setting window.
FIG. 4 is a diagram illustrating a layout printing settings input window.
FIG. 5 is a diagram illustrating a layout exclusions setting window.
FIG. 6 is a diagram illustrating a layout exclusions setting window.
FIG. 7 is a diagram illustrating a result of printing excluded from layout.
FIG. 8 is a flowchart illustrating the flow of processes performed by a layout processing module.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
Hereinafter, a printing control apparatus that controls a printer will be described with reference to the drawings.
Embodiment
FIG. 1 is a diagram illustrating the overall configuration of a computer 10 , in which a printer driver 50 has been installed, functioning as a printing control apparatus. As shown in FIG. 1 , the computer 10 includes a CPU (Central Processing Unit) 11 that functions as the center of computational processes, and the CPU 11 is capable of accessing a ROM (Read-Only Memory) 13 , a RAM (Random Access Memory) 14 , and the like via a system bus 12 . A hard disk drive 15 , a CD-ROM drive 16 , and a Floppy® disk drive 17 , serving as external storage units, are connected to the system bus 12 ; an operating system, an application program capable of creating document information, image information, and so on (not shown) and the like are stored as software in a hard disk 22 that is connected to the hard disk drive 15 and that stores data. The software is transferred to the RAM 14 as appropriate by the CPU 11 when the software is to be executed. The CPU 11 accesses the RAM 14 as appropriate and executes the software. In other words, various programs are executed using the RAM 14 as a temporary work area.
An input interface 18 is connected to the stated system bus 12 , and a keyboard 27 , a mouse 28 , or the like are connected to the input interface 18 as operation input devices. In addition, a CRT interface 19 is connected to the system bus 12 , and a display 29 is connected via this CRT interface 19 . Furthermore, a printer interface 20 is connected to the system bus 12 , and a printer 30 that prints predetermined print jobs is connected via this printer interface 20 . In this embodiment, the configuration of the computer 10 is described in a simplified manner, but it goes without saying that a typically-configured personal computer can be employed as the computer 10 .
However, the computer 10 applied in this embodiment is not intended to be limited to a personal computer. The computer 10 is also not limited to a desktop computer, and may instead be a laptop computer or another type of mobile computer. Furthermore, the connection interface between the computer 10 and the printer 30 need not be limited to a parallel connection, and various types of connections, such as a serial interface, SCSI (Small Computer System Interface), USB (Universal Serial Bus), or the like, can be used.
In addition, although the various types of software mentioned above are stored in the hard disk 22 , the recording medium capable of storing the various pieces of software is not limited to the hard disk 22 . For example, the recording medium may be a CD-ROM 23 , a Floppy® disk 24 , or the like. The software recorded on these recording media are thus loaded into the computer 10 via the CD-ROM drive 16 , the Floppy® disk drive 17 , or the like, and are then installed in the hard disk 22 . The software is loaded into the RAM 14 from the hard disk 22 by the CPU 11 as mentioned above, and the various processes are then executed. The recording medium is not limited to the aforementioned examples, however, and a magneto-optical disk or the like may be used as well. Furthermore, a non-volatile memory such as a flash memory serving as a semiconductor device may also be employed. Alternatively, a predetermined communication line 25 can be connected to through a communication interface 21 such as a modem connected to the system bus 12 , and the various types of software can then be downloaded by accessing a file server 26 located on the communication line 25 that is capable of storing such program types.
The printer 30 includes a CPU, firmware, and the like (not shown), and, in accordance with a program denoted in the firmware, receives print job data configured of CMYK data, page description language, or the like sent by the computer 10 through the printer interface 20 . Then, the printer 30 executes printing while driving a print head, a print paper transport mechanism, and so on using a predetermined driving device, based on the print job data.
Next, FIG. 2 is a diagram illustrating the configuration of modules in the printer driver 50 . The printer driver 50 includes a print settings obtainment module 54 , a layout processing module 56 , an image processing module 60 , a halftone processing module 62 , a print image data formation module 64 , and a function control module 52 that controls the various functional units; the modules 54 to 64 generate print job data by operating together while realizing predetermined functions based on the control of the function control module 52 .
The print settings obtainment module 54 obtains various types of print settings. In this embodiment, print settings set through a UI (User Interface) window of the printer driver 50 are stored in a storage region called “Devmode”. The print settings obtainment module 54 obtains print setting information from the Devmode storage region.
The layout processing module 56 is a layout processing unit, and arranges, upon a single sheet, the bitmaps of multiple pages expanded based on the print settings when the print image data formation module 64 forms print image data. This layout processing module 56 includes a scaling processing unit 58 (a scaling processing unit) that carries out a process for enlarging or shrinking the bitmaps.
Here, in, for example, the case in which two pages of an A4 original (in portrait orientation) are laid out on A4 paper (in landscape orientation) (2-up), the scaling processing unit 58 shrinks to develop the bitmaps of the originals to an A5 portrait region by communicating a resolution that is lower than the resolution of the originals to a GDI (Graphical Device Interface). The layout processing module 56 then arranges the bitmap of the first page in a printing start position on the A4 paper (in landscape orientation) and cancels a page break control command. Next, the layout processing module 56 arranges the bitmap of the next page in a position located one A5 page's worth of space from the printing start position on the A4 paper (in landscape orientation), and adds the page break control command; through this, the layout process can be executed.
Meanwhile, for specified pages, the layout processing module 56 allocates a single original to a single page without carrying out the layout process (1-up). In this embodiment, pages for which the layout process is not to be carried out (excluded pages) are specified through a UI window, mentioned later. In this case, the scaling processing unit 58 can carry out only enlargement or shrinking processes for the pages to be excluded from the layout process by communicating a resolution that differs from the resolution of the original to the GDI. These settings are defined in an extension region of the Devmode storage region.
The image processing module 60 carries out image processes such as color correction processes or the like. Meanwhile, the halftone processing module 62 carries out a halftone process on the print data on which the image process such as the color correction process or the like has been carried out. The print image data formation module 64 is a print data generation unit, and creates print job data by forming the print image data created by the layout processing module 56 , the image processing module 60 , and the halftone processing module 62 on a page-by-page basis. The created print job data is sent to the printer 30 via a spooler, where printing is executed based on the print job data.
Here, in this embodiment, when a user prints a document or the like by selecting printing in an application program, predetermined print settings are carried out in the printer driver 50 that is launched when printing is selected. At this time, the user calls a printing conditions setting window 100 , shown in FIG. 3 , in order to select printing functions in the application program.
The printing conditions setting window 100 accepts the input of print settings specified by the user. The printing conditions setting window 100 includes regions for accepting specifications of items, such as paper size 101 , orientation 102 , paper source 103 , paper type 104 , color 105 , dual-sided printing 106 , layout 108 , and so on. The user can set his or her desired conditions in the respective regions.
The printing conditions setting window 100 also includes a layout settings button 110 . The layout settings button 110 can be pressed in the case where layout 108 is checked. When the layout settings button 110 is pressed, a layout settings input window 200 , shown in FIG. 4 , is displayed.
The layout settings input window 200 is an accepting unit for accepting the input of layout settings specified by the user for layout printing. The layout settings input window 200 includes a layout number of pages setting region 210 , a layout order setting region 220 , and a layout exclusions setting button 230 for setting pages to be excluded from layout.
The layout number of pages setting region 210 accepts settings for the number of pages to allocate to a single page. In the example shown in FIG. 4 , two pages or four pages can be selected. Meanwhile, the layout order setting region 220 accepts the selection of an order by which to allocate multiple pages to a sheet.
When the layout exclusions setting button 230 is pressed, a selection unit, or in other words, a first layout exclusions setting window 250 , shown in FIG. 5 , or a second layout exclusions setting window 270 , shown in FIG. 6 , is displayed. Which of the windows to display may be set by the user in advance. Alternatively, the printer driver 50 may analyze the document information to be printed and determine which window to display based on, for example, whether document data and image data are intermixed. Furthermore, in the case where automatic processing has been set in advance and the layout exclusions setting button 230 has been pressed, predetermined layouts may be excluded according to the automatic processing settings, instead of displaying the setting windows. In this case, the layout exclusions may be determined based on the attribute information, the data type, and so on for the respective pages. In other words, the layout exclusions may be determined automatically in the case where graphics, photographs, and so on have been allocated to the page.
The first layout exclusions setting window 250 displays graphic images 253 of the respective pages in page order, and displays layout exclusion checkboxes 255 in a selectable manner for each of the graphic images 253 . Meanwhile, in the case where a document size that is different from the output paper size set by the printer driver 50 is included, a setting checkbox 260 is displayed for the graphic image 253 of that page so as to be selectable, regardless of layout exclusion settings.
In addition, in the lower portion of the first layout exclusions setting window 250 , all-set buttons 265 are displayed in a selectable manner so that the graphic images 253 for all pages can be set at once.
The second layout exclusions setting window 270 displays graphic images 273 for the respective pages in page order, and furthermore displays the graphic images 273 in groups based on data type information 275 indicating attributes of the respective graphic images 273 ; further still, layout exclusion checkboxes 280 are displayed so that selections can be carried out by groups. In this embodiment, in the case where a page of a document size that differs from the output paper size set by the printer driver 50 is included in a group, a set checkbox 285 is displayed in a selectable manner for that group regardless of the settings for layout exclusion. Note that the data type of the graphic images 273 , information indicating whether or not objects are included, and so on are determined based on information exchanged between the GDI and the printer driver 50 (that is, font image information, pass rendering information, image rendering information, and so on). In this embodiment, the data type is either “document” or “image”, but the data type is not limited to these two. Furthermore, in the case where “document” data and “image” data are intermixed in the same page, the page is placed into an “image” group.
In addition, in the lower portion of the second layout exclusions setting window 270 , all-set buttons 290 are displayed in a selectable manner so that the graphic images 273 for all pages can be set at once.
The information set in the first layout exclusions setting window 250 shown in FIG. 5 or the second layout exclusions setting window 270 illustrated in FIG. 6 are written into a predetermined location in the Devmode storage region. FIG. 7 illustrates examples of printing results in this embodiment in the case where A3 or L-sized originals are intermixed in an A4 document and the output paper is set to A4.
FIG. 8 is a flowchart illustrating the flow of processes performed by the layout processing module 56 . This process is called in the case where the printer driver 50 is to carry out a layout process. When this process is started, first, the CPU 11 of the computer 10 obtains the layout settings written into the Devmode storage region (step S 300 ). Then, the CPU 11 obtains information of a predetermined first page (step S 310 ). Next, the CPU 11 determines whether or not a shrinking or enlargement process has been instructed for that page (step S 315 ).
In the case where it has been determined that a shrinking or enlargement process has been instructed for that page (Yes in step S 315 ), the CPU 11 carries out the enlargement or shrinking process on that page in accordance with the output paper that is set (step S 320 ), and the process advances to step S 325 . On the other hand, in the case where it has been determined that a shrinking or enlargement process has not been instructed for that page (No in step S 315 ), the process advances to step S 325 .
In step S 325 , the CPU 11 determines whether or not that page has been excluded from layout. Here, in the case where it has been determined that that page has not been excluded from layout (No in step S 325 ), the CPU 11 carries out a layout process (step S 330 ), and the process advances to step S 335 . On the other hand, in the case where it has been determined that that page has been excluded from layout (Yes in step S 325 ), the process advances to step S 335 .
In step S 335 , the CPU 11 forms the print image data for the first page. Then, the CPU 11 determines whether or not all of the pages have been processed (step S 340 ).
Here, in the case where it has been determined that all of the pages have not yet been processed (No in step S 340 ), the CPU 11 obtains the information of the next page (step S 345 ), returns to the step of determining whether or not a shrinking or enlargement process has been instructed (step S 315 ), and processes the pages thereafter in order. On the other hand, in the case where it has been determined that all the pages have been processed (Yes in step S 340 ), the CPU 11 generates the print data (step S 350 ) and ends the series of processes.
According to the embodiment described thus far, pages that are to be excluded from layout can be set through a UI window such as the first layout exclusions setting window 250 or the second layout exclusions setting window 270 , and thus it is possible to specify, visually and easily, which pages are to be excluded from layout. Furthermore, even in the case where a page of a document size that differs from the output paper size set by the printer driver 50 is included, such a page can be visually identified and laid out in accordance with the output paper size.
Although an embodiment of the invention has been described with reference to the drawings, the specific configuration thereof is not intended to be limited to this embodiment, and various alterations, variations, and the like are possible without departing from the essential spirit of the invention. Furthermore, the apparatuses that execute the aforementioned methods may be realized by single, independent apparatuses, or may be realized by a combination of multiple apparatuses; all such forms are considered to fall within the scope of the invention. | A printing control apparatus includes: an accepting unit that accepts a setting regarding layout printing for laying out multiple document pages in order on a sheet-by-sheet basis; a selection unit that, in the case where the layout printing setting has been accepted by the accepting unit, displays graphic images of the multiple document pages and allows a specific page for which layout printing is not to be carried out to be selected from among the graphic images; a layout processing unit that does not perform the layout for the specific page selected through the selection unit and does perform the layout for the document pages aside from the specific page; and a print data generation unit that generates print data of the multiple document pages based on a result of the processing performed by the layout processing unit. | 6 |
FIELD OF INVENTION
[0001] The present invention relates to devices for multi-stage, horizontal well isolation and fracturing.
BACKGROUND OF THE INVENTION
[0002] An important challenge in oil and gas well production is accessing hydrocarbons that are locked in formation and not readily flowing. In such cases, treatment or stimulation of the formation is necessary to fracture the formation and provide passage of hydrocarbons to the wellbore, from where they can be brought to the surface and produced.
[0003] Fracturing of formations via horizontal wellbores traditionally involves pumping a stimulant fluid through either a cased or open hole section of the wellbore and into the formation to fracture the formation and produce hydrocarbons therefrom.
[0004] In many cases, multiple sections of the formation are desirably fractured either simultaneously or in stages. Tubular strings for the fracing of multiple stages of a formation typically include one or more fracing tools separated by one or more packers.
[0005] In some circumstances frac systems are deployed in cased wellbores, in which case perforations are provided in the cemented in system to allow stimulation fluids to travel through the fracing tool and the perforated cemented casing to stimulate the formation beyond. In other cases, fracing is conducted in uncased, open holes.
[0006] In the case of multistage fracing, multiple frac valve tools are used in a sequential order to frac sections of the formation, typically starting at a toe end of the wellbore and moving progressively towards a heel end of the wellbore. It is crucial that the frac valves be triggered in the desired order and that they do not open earlier than desired. Once open, it is also important that the frac valves do not become closed until it is desirable to close them.
[0007] Many configurations have been developed in the field to frac multiple stages of a formation. For example fracing tools are known in which a ball is pumped into the tool and sits in a seat to block fluid flow through the central bore, thereby causing fluid pressure to build up and forcing fluid to flow through multiple jet nozzles located circumferentially around the liner.
[0008] Other frac valve tools are known for use with coiled tubing, in which a ball is dropped to block flow down the liner and redirect flow through pressure firing heads in a fracking sleeve. Some downhole tools teach including a packer with a ball seat and a ball, in which fluid can be redirected to fracking ports on a fracing tool. Others teach the use of balls of different sizes to control downhole surge pressure.
[0009] A need still however exists for frac valve tools that are simple in construction, small in size and effective at fracing formations in multiple stages
SUMMARY OF THE INVENTION
[0010] In a first aspect, a frac valve tool is taught, said tool comprising one or more ports a sleeve movable between a closed position in which the sleeve prevents fluid flow through said one or more ports and an open position in which the sleeve allows fluid flow through said one or more ports and a ball receiving seat removably connected to the sleeve wherein receipt of a ball on the ball receiving seat moves said seat and said sleeve from closed to open positions.
[0011] In a second aspect, a frac valve tool is taught, said tool comprising a ball receiving seat removably received within said tool, said seat comprising a seating profile for receiving a ball; wherein said seating profile matches a radius of said ball to nondeformably grip said ball.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is a schematic diagram of a horizontal well fitted with the tools of the present invention;
[0013] FIG. 2 is a cross sectional view of one example of the frac valve of the present invention in a closed position;
[0014] FIG. 3 is a cross sectional view of one example of the frac valve of the present invention in an opened position;
[0015] FIG. 4 is a cross sectional view of one example of the frac valve of the present invention in an open position with the seat drilled out;
[0016] FIG. 5 is a cross sectional view of one example of the frac valve of the present invention in a closed position with the seat drilled out; and
[0017] FIG. 6 is a cross sectional elevation view of a quality control inspection fixture for use with the frac valve of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] A frac valve tool is provided that improve on existing ball drop, multi-stage, horizontal fracturing tools, by providing increased safety during installation, reduced rig time and greater dependability in fracing multiple stages in a horizontal section of the wellbore.
[0019] By combining both a slim outside diameter and short length, the present frac valve tool eliminates the need for handling pup joints, thereby reducing the rigidity of the liner. These features permit the more flexible, reduced outside diameter tool string to be deployed into the wellbore with greater ease.
[0020] The present frac valve tools can be lifted by hand and hand threaded onto the liner, which is typically gripped at the rig floor, and then a section of upper liner, typically gripped in an elevator or similar device, can lowered onto the frac valve tool and the one piece body of the frac valve tool allows torque to be applied from the upper liner section, through the frac valve tool and into the liner to make up the liner string.
[0021] The present frac valve tool can be deployed with associated tools along a liner and deployed into the open hole section of the wellbore. The present frac valve tools provide a means of stimulating a section of the formation to induce fracturing of the formation and flow of formation fluids. The short length of the frac valve tool 400 eliminates the need for pup joints on either end. The small outside diameter and short length increases liner flexibility, further aiding deployment into the wellbore. In a preferred embodiment, the present frac valve tool 400 eliminates the typical threaded connection between the top of the tool and the mandrel. Instead, a box end connection and the mandrel are integral and an installation tool is utilized to insert the frac valve tool 400 inside the mandrel. The use of the special installation tool permits the elimination of a threaded connection thereby shortening the frac valve tool length.
[0022] With reference to FIG. 1 , in a preferred method of deployment, the present frac valve tools can be deployed on a tubing string further comprising a float shoe or guide 50 at the toe of the liner, an activation tool 100 at a pre-determined distance from the guide shoe 50 , a first stage frac valve tool 200 , and then an series comprising an open hole packer 300 alternated with the present frac valve tools 400 to a final cased hole packer 500 . It would be well understood by a person of skill in the art that FIG. 1 merely represents one example of a tubular fracing string of tools and that additions, omissions and alterations to the illustrated string and its components can be made without departing from the scope of the present invention.
[0023] The present frac valve 400 is located in the liner between two open hole packers 300 and is depicted in FIGS. 2 , 3 , 4 , 5 and 6 . The frac valve 400 comprises a mandrel 420 that is preferably full bore and has an inside diameter matching the inside diameter of the liner. One or more ports 410 are formed around the circumference of the mandrel, said ports 410 providing fluid communication between the inside of the liner and the open hole wellbore. The mandrel 420 contains within it a sleeve 408 connected to the mandrel by one or more shear screws 406 . In a closed position, the sleeve 408 blocks fluid passage through the one or more ports 410 . Within the sleeve 408 is a seat 404 that can receive a ball 402 that is deployed into the liner from the rig floor and pumped onto the seat 404 by fluid pressure.
[0024] The present frac valve 400 is preferably pressure balanced due to sealing by o-rings that straddle the ports, such that the sleeve 408 is not shifted to the open position until the ball 402 lands on the seat 404 . After the ball 402 is pumped onto the seat 404 , liner pressure generates a force which shears shear screws 406 allowing the seat 404 and sleeve 408 to shift, opening communication through the one or more ports 410 .
[0025] The seat 404 of the present frac valve 400 is preferably surface hardened to prevent erosion that can be caused by proppants pumped through them. The seats 404 are manufactured from a material and in a geometry that can withstand the stress generated by the ball 402 landing and seating under high differential pressure, while providing adequate support for the ball 402 . Suitable materials for the present seat 404 may be most cast irons, including Class 40 Gray Iron or Class 50 Gray Iron, although other suitable materials would be known to a person of skill in the art and are encompassed by the scope of the present invention. The seats are more preferably treated with liquid nitrogen to achieve a Rockwell hardness rating of HRC 50 to 55.
[0026] The present seat preferably comprises a seating profile 416 that receives and in part grips the ball 402 in the seat to ensure the ball 402 is not inadvertently unseated until desired. The seat radius 416 is advantageously designed to allow gripping of the ball 402 without sheering the ball 402 or causing plastic deformation. The present seating profiles requires only low pump off pressure to lift the ball 402 off of the seat 404 by pressure from the formation, after fracturing is complete. This is due to the seating profile 416 being preferably matched to a corresponding ball 402 radius to prevent the ball 402 from deforming and becoming wedged into the seat 404 .
[0027] The relationship between the geometry of the seating profile 416 and the matching ball 402 is preferably designed to permit a variety of ball 402 to seat 404 size ratios for a number of liner applications. The matching geometry of the seating profile 416 and the ball 402 permits a seat 404 of the present design to be adapted for use with many ball and seat sizes, thereby reducing the size increments of seats 404 that need to be manufactured. In a preferred embodiment, the size and geometry of the seating profile 416 can be adjusted relation to the size of ball 402 to be used, this reduces potential hoop stresses that can build up in the ball 402 , and ensure that an optimal relationship between proper seating and low pump off pressure.
[0028] The ball 402 used with the present invention can be any ball well known and used in ball drop tools found in the state of the art. More preferably, the ball 402 is composed of a non-elastomeric material that shows strength, corrosion resistance against stimulant fluids and wellbore fluids and a degree of flexibility. Such materials can include but are not limited to phenolics, composites or aluminum.
[0029] The seat 404 is preferably manufactured with a minimum amount of material to allow the seat 404 to be drilled out after use, thereby minimizing drill out times. In particular, the seat material is designed to be friable and crumble upon drilling, thereby reducing the chance of large drilled out fragments from blocking the liner.
[0030] With reference to FIG. 4 , the seat 404 of the present frac valve 400 is drilled out after fracturing is complete. The geometry of the seat 404 and the method used to fasten it to the sleeve 408 ensures the seat 404 will drill up into fine particles, eliminating the possibility of large pieces of debris falling onto the next seat 404 to be drilled out. Such debris adds to the time required for the subsequent seat 404 to be drilled out and tends to rotate and grind against the next seat 404 .
[0031] Preferably one or more anti-rotation tabs 414 located inside the frac valve 400 assists seat drill out by holding the seat 404 stationary. More preferably the seat 404 is threaded into the sleeve 408 in such an orientation that drilling out the seat 404 urges the threads into tightening, thereby additionally serving to hold the seat 404 in place in the sleeve 408 . The threads 418 on the seat 404 and on the sleeve 408 are most preferably left hand threads that tend towards tightening when the seat 404 is drilled. These threads 418 also allow the seats 404 of any frac valve tool 400 to be changed as needed, for example should damage be detected in a seat 404 , or should on-site adjustments need to be made for different ball and seat sizes for one or more frac valve tools 400 .
[0032] In a further preferred embodiment, a quality control inspection fixture 700 , illustrated in FIG. 6 is used to check five dimensional characteristics of each frac valve 400 , to ensure correct placement of each valve in the liner. The quality control fixture 700 checks the bore hole size through the seat 404 , and the bore in which the ball 402 lands. It checks the concentricity of both bores to ensure proper sealing whenever the ball 402 lands on the seat 404 . The quality control inspection fixture 700 checks the geometry of the seat profile 416 and also the distance from the seat 404 to the top of the frac valve 400 , to ensure proper assembly of the frac valve tool 400 . The quality control inspection fixture 700 is preferably attached to a seat installation tool (not shown) to assist in ensuring the correct seat 404 is being installed into the frac valve tool 400 .
[0033] In some cases, the frac valve seat 404 can be drilled out to the drift inside diameter of the liner Drift diameters are specified by the American Petroleum Institute (API) for each weight of casing. An object of a given drift diameter and given length as specified by API must fit through the inside diameter of the pipe.
[0034] Although it is common to run one frac valve 400 per isolated section of the formation, it is also possible to place multiple frac valves 400 in any given isolated section. In a preferred embodiment, the frac valve 400 can be configured to have a closable feature. The closable frac valve 400 can be closed by a number of means. One embodiment permits the frac valve 400 to be closed before drilling out the seats, in this case a shifting tool run on tubing is used to close the frac valve 400 . A second embodiment, illustrated in FIG. 5 , allows the frac valve 400 to be closed after the seat 404 is drilled out. Multiple frac valves 400 or a single frac valve 400 may be shifted from an open to a closed position with a further second style of shifting tool 412 .
[0035] The total flow area through all of the fracture ports 410 of the frac valve 400 is preferably greater than the flow area through the liner.
[0036] Sometimes a sand off occurs during the fracing operation when no more sand can be pumped into the formation and the sand remains indie the liner preventing the ability to pump the next ball down the well. In such cases, an opening tool (not shown) can be run through the tubing and landed on the seat 404 . In such cases, applied pressure in the annular area between the inside wall of the liner and the outside diameter of the tubing is used to pump the frac valve 400 into the open position.
[0037] In one example of operation of the present frac valve tool 400 , a liner may be assembled with a float shoe 50 , an activation tool 100 , a liner, a first stage frac valve tool 200 , and then a series comprising a liner, an open hole packer 300 , a liner and the present frac valve tools 400 . Optionally, an open hole anchor may be used between the activation tool 100 and the first stage frac valve tool 200 to anchor the liner to the wellbore. Alternative to an open hole anchor centralizers, stabilizers or other suitable means known in the art may also be used for this purpose.
[0038] Preferably up to 40 frac valves 400 , on a 4½″ liner for example, separated with open hole packer 300 s can be used in a string. In operation, the seats 404 of the frac valve tools 400 sequentially increase in the size of ball 402 they can receive; with the smallest seat 404 being closest the toe end of the wellbore and the largest seat 404 being at the heel end. A cased hole packer 500 is attached to the upper end of the liner. A latch seal assembly or other known means can be used to attach the cased hole packer 500 to the work string.
[0039] The liner is run into the conditioned bore hole by a work string or on a frac string. At a predetermined depth the activation tool 100 is activated to stop fluid flow. Pressure in the liner now increases from a triggering pressure at which both the cased hole packer 500 and the open hole packers 300 begin to set, to a final pack off pressure at which the cased hole packer 500 and open hole packers 300 are fully set. A pressure test may optionally be performed inside the casing to determine if the cased hole packer 500 has set properly. If the liner was run on a work string, the latch seal assembly or other connection means can next be removed from the cased hole packer 500 and the work string and latch seal assembly are removed from the well and a frac string and latch seal assembly are deployed. Otherwise, if the liner was run downhole on a frac string, no replacement has to be made.
[0040] Further pressure is applied to the fracture string. At a pre-determined opening pressure that is higher than the pack off pressure, the first stage frac valve tool 200 shifts to the open position and stimulation fluid is pumped into the formation and causes it to fracture. Proppant is then pumped into the fracture. Next, a first ball 402 is pumped into the liner corresponding to the seat sizes of the frac valve tool 400 closest the toe of the wellbore. By this process the frac valve tool 400 is activated to thereby open ports 410 to allow communication between the inside of the liner and the isolated section of the formation between the two open hole packer 300 straddling the particular frac valve 400 . Subsequent frac valve tools 400 are similarly activated by pumping subsequent balls 402 into the liner in sequential size order.
[0041] The stimulation fluid pumped through the ports of the frac valve 400 fractures the exposed formation between the open hole packers 300 used to isolate that stage. Whenever this stage has been fractured, a next frac valve 400 is activated and the process is repeated. The process can be repeated up to 40 times in total in a 4½″ liner, for example. Other sizes of liners have a different number of frac valve tools 400 and open hole packers 300 . When all the desired stages have been fractured, the well is allowed to flow and formation pressure from formation fluid flow acts to deactivate the frac valves 400 by pumping balls 402 off of the seats 404 , and allows formation fluid flow into the liner. Afterwards the frac string and connecting means can be removed from the well.
[0042] If desired, the seats of the frac valves 400 can be drilled out at a later date.
[0043] In the foregoing specification, the invention has been described with specific embodiments thereof; however, it will be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. | In a first aspect, a frac valve tool is taught, said tool comprising one or more ports a sleeve movable between a closed position in which the sleeve prevents fluid flow through said one or more ports and an open position in which the sleeve allows fluid flow through said one or more ports and a ball receiving seat removably connected to the sleeve wherein receipt of a ball on the ball receiving seat moves said seat and said sleeve from closed to open positions. In a second aspect, a frac valve tool is taught, said tool comprising a ball receiving seat removably received within said tool, said seat comprising a seating profile for receiving a ball; wherein said seating profile matches a radius of said ball to nondeformably grip said ball. | 4 |
This application is a division of application Ser. No. 386,219, filed Jul. 28, 1989.
BACKGROUND OF THE INVENTION
This invention relates to a metal gasket for use in automobile engines, screw engines, freezing equipment, air conditioning units and the like and a method of producing the metal gasket.
As gaskets for automobile engines, so-called asbestos type gaskets have been widely used which are made of single, jointed or beat sheets of asbestos as sole or composite materials. Recently, however, various kinds of new type gaskets have been progressively practically used which are made of metals, graphites, fibers and the like as sole or composite materials in place of the asbestos causing a problem of public nuisance. Particularly, metal gaskets provided on their surfaces with rubber layers are superior in performance and cost to other new gaskets in substitution for the asbestos gaskets and expected to be widely used in future.
Sealing faculty and durability are important among various faculties required as gaskets for automobiles. It has been proposed to deposit a rubber coating layer directly on surfaces of a metal plate as a substrate in order to improve the sealing faculty. In case of metal gaskets, however, the sealing faculty and durability depend mainly upon bonding power between the metal plate and the rubber coating layer. It is therefore important in manufacturing the rubber coated metal gaskets to improve the bonding power therebetween and to prevent the bonding power from lowering in used conditions.
Therefore, attempt has been made to improve the bonding power between the metal plate and the bonding layer or the rubber layer and to maintain the improved bonding power for a long period of time with the aid of an activation treatment or galvanizing which is applied to the surfaces of the metal plate.
Recently, however, high performance automobile engines have been developed and widely used so that metal gaskets are also used under severer conditions, with the result that the durability of the gaskets becomes more important. Under such circumstances, even the above gaskets of metals coated with rubber coating layers encounter a problem of insufficient durability.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a metal gasket and a method of producing the same which eliminate all the disadvantages of the prior art and provide an improved metal gasket which has high bonding power of rubber layers to a metal substrate to improve the durability of the metal gasket for long use.
In order to achieve the object, a metal gasket according to the invention comprises a metal plate, a chromate film on at least one surface of the metal plate formed by coating a non-rinse chemical for chromate conversion thereon, an adhesive coating on the chromate film and a rubber compound layer provided thereon.
A method of producing a metal gasket according to the invention comprises steps of coating a non-rinse chemical for chromate conversion on at least one surface of a metal plate and drying it in a first process, coating an adhesive thereon in a second process, and providing a rubber compound layer thereon and vulcanizing it in a third process.
According to the invention, by coating the non-rinse chemical for chromate conversion on a metal plate before providing a rubber type coating layer on the metal plate, the bonding power of the rubber layers to the metal plate is further improved to obtain the superior durability for long use.
Moreover, the chromate treatment with the non-rinse chemical for chromate conversion used in the invention is easy in operation in comparison with the chemical reaction conversion and the electrolytic treatment. Furthermore, the chromate treatment has an advantage enabling thicknesses of the chromate films to adjust easily.
The invention will be more fully understood by referring to the following detailed specification and claims taken in connection with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of one embodiment of a metal gasket according to the invention;
FIG. 2 is an enlarged sectional view of the gasket shown in FIG. 1;
FIG. 3 is a partial enlarged view of FIG. 2;
FIG. 4 is a block diagram illustrating processes for carrying out the method according to the invention; and
FIGS. 5a and 5b are views for explaining the boiling water and antifreeze coolant durability tests for metal gaskets.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates one embodiment of the metal gasket according to the invention. The metal gasket comprises a metal plate 1 as a substrate and coating layers C coated on both surfaces of the metal plate 1 (FIGS. 2 and 3). The gasket is formed with a cylinder opening 2, cooling water openings 3 and bolt apertures 4. The gasket is further formed with beads 5 about the cylinder opening 2 and the cooling water openings 3.
As shown in FIG. 3 illustrating a section of the gasket on an enlarged scale, the metal gasket is made in the following processes. First, a metal plate 1 is pickled or cleaned and water-rinsed. Surfaces of the metal plate 1 are then coated with a non-rinse chemical for chromate conversion shown at 6 in FIG. 3. After the coated metal plate 1 has been dried, the coated surfaces are further coated with a rubber adhesive 7 and baked. Moreover, the surfaces coated with the rubber adhesive are coated with a rubber compound 8. Thereafter, the rubber compound on the metal surfaces is vulcanized to complete the coating layers C on the surfaces of the metal plate 1.
The metal plate as substrate may be a stainless steel sheet or a carbon steel sheet. As an alternative, it may be zinc-plated stainless plate or a zinc-plated carbon steel plate.
The method of producing the metal gasket according to the invention will be explained in detail hereinafter.
Processes of the method is shown in a process flow diagram in FIG. 4. As shown in FIG. 4, the chromate film 6 on the metal plate 1 is produced in a first process and the rubber adhesive 7 is provided in a second process. The rubber compound 8 is provided in a third process. The chromate film 6 is produced by a tarnishing reaction of the chromate conversion in the first process. A stainless steel plate coil having a predetermined thickness is used as a blank material which is pickled and water-rinsed in the first process.
In the first process, a chemical for chromate conversion for steel materials consisting mainly of an aqueous chrome composition and functional chemicals is coated on the metal surface and dried to form the chromate film 6 which is closely bonded to the metal plate 1 and has a chromium of the order of 20-30 mg/m 2 as shown in FIG. 3.
In the second process, the rubber adhesive as a primer is coated on the chromate film 6 and baked to form the rubber adhesive layer 7. The adhesive layer 7 is closely bonded onto the chromate film 6 and has a thickness of the order of 5-30 μm.
In the third process, moreover, the heat-resistant rubber compound is coated on the adhesive layer 7 to a predetermined thickness and vulcanized to form the rubber layer 8 closely bonded to the adhesive layer 7. In this manner, a rubber coated metal as a substrate for the metal gasket is obtained.
In stead of coating the rubber compound in the third process, a rubber compound in the form of a sheet or kneaded amorphous rubber compound having a predetermined thickness may be attached to the adhesive layer. In the third process, after the rubber compound is coated on the adhesive layer, the rubber compound layer may be heated and vulcanized, while surface pressure is being applied to a surface of the rubber compound layer.
The chromate film 6 formed in the first process of the method according to the invention has great effects to improve the practical use of the metal gasket. In more detail, the chromate film 6 servers to increase the bonding force and improve the scratch-resistance, water-resistance, antifreeze coolant-resistance and the like.
By providing the chromate film 6, the resistance to physical or mechanical scratching is increased so that occurrence of scores in the adhesive layer and the rubber layer is prevented. The scratch-resistance is estimated by a coin scratch test wherein surfaces in question are scratched by a jig in the form of a coin having serrations at its edge.
There are various testing methods for estimating the performance of rubber coated metals, such as Erichsen test, water-resistance test, antifreeze coolant-resistance test, brine-resistance test, oil-resistance test and the like. The sealing faculty and durability are important as useful properties for metal gaskets and depend mainly upon the bonding power for a long period of time between the metal plate and the rubber layer. Therefore, in order to ascertain the bonding power of the rubber layer for long time, rubber coated metals as substrates of metal gaskets are often tested by boiling water durability test and antifreeze coolant durability test as durability tests for metal gaskets for automobiles. With these tests, it can be judged that the longer the time until rubber layers separate, the higher is the bonding power for long time.
In order to compare the rubber coated metals of the embodiment of the invention with those of the prior art (Comparative Example), a comparative test was effected. At the same time, performances of the rubber coated metals according to the invention were tested by changing ingredients of the adhesive and the rubber compound used in the second and third processes and changing amounts of chromium of the chromate film formed in the first process.
TABLE I______________________________________Comparative Test Comparative Embodiment 1 example______________________________________Blank material SUS * SUSAmount of chromium by 30 mg/m.sup.2 nonechromate treatmentAdhesive NBR type NBR type (standard (standard ingredient) ingredient)Rubber compound NBR type NBR type (standard (standard ingredient) ingredient)Boiling water durability >2,000 h 72 htest (100° C.)Antifreeze coolant 168 h 24 hdurability test (130° C.)______________________________________ * Stainless steel (Japanese Industrial Standard)
TABLE II______________________________________Amounts of chromium affectingperformances of metal gaskets Embodiment Embodiment Embodiment 1 2 3______________________________________Blank material SUS SUS SUSAmount of chro- 30 mg/m.sup.2 60 mg/m.sup.2 100 mg/m.sup.2mium by chromatetreatmentAdhesive NBR type NBR type NBR type (standard (standard (standard ingredient) ingredient) ingredient)Rubber compound NBR type NBR type NBR type (standard (standard (standard ingredient) ingredient) ingredient)Boiling water dura- >2,000 h >4,000 h >5,000 hbility test (100° C.)Antifreeze coolant 168 h 240 h 336 hdurability test(130° C.)______________________________________
TABLE III______________________________________Ingredients of rubber affectingperformances of metal gaskets Embodiment Embodiment Embodiment 1 4 5______________________________________Blank material SUS SUS SUSAmount of chro- 30 mg/m.sup.2 30 mg/m.sup.2 30 mg/m.sup.2mium by chromatetreatmentAdhesive NBR type NBR type NBR type (standard (ingredient (ingredient ingredient) to enhance to heat- antifreeze resistance) coolant resistance)Rubber compound NBR type NBR type NBR type (standard (ingredient (ingredient ingredient) to enhance to heat- antifreeze resistance) coolant resistance)Boiling water dura- >2,000 h >2,000 h >3,000 hbility test (100° C.)Antifreeze coolant 168 h 216 h 312 hdurability test(130° C.)______________________________________
The ingredient of the rubber compound in the above tests was an NBR (acrylonitrile butadiene rubber) polymer, a curing agent, a reinforcer, a plasticizer, an accelerator, an antioxidant and a filler. In the embodiments 4 and 5 in Table III, different kinds of the polymer and different amounts thereof from those of the standard ingredient were used.
The boiling water durability test and the antifreeze coolant durability test were carried out in the following manner. As shown in FIG. 5a, specimens of the rubber coated metals were rectangular plates 11 of a size 50 mm × 100 mm. Each specimen was formed on upper and lower halves with marking-off lines 12 in a checkerboard pattern whose distances between the lines were about 1 mm as shown in FIG. 5a.
The lower half of the specimen 11 was immersed in a liquid 14 in a vessel 13 as shown in FIG. 5b. The liquid 14 was maintained at 100° C. in the boiling water durability test and at 130° C. in the antifreeze coolant durability test. Hours until the marking-off lines 12 disappeared were measured. The longer the time, the better was the durability. The upper portion of the specimen was exposed to vapour 15 of the liquid 14 in the test.
As can be seen from Table I, the metal gasket according to the invention is considerably improved in the boiling water durability and the antifreeze coolant durability.
As shown in Table II, the boiling water durability and antifreeze coolant durability are significantly improved by increasing the amount of chromium in the chromate treatment.
Moreover, the boiling water durability and antifreeze coolant durability are also remarkably improved by changing the ingredients of the rubber compound to enhance the heat-resistance and the antifreeze coolant resistance as shown in Table III.
It is clear that the metal gasket according to the invention is superior in keeping high bonding power of the coating in long use.
As can be seen from the above description, according to the invention by coating the non-rinse chemical for chromate conversion on a metal plate before providing a rubber type coating layer on the metal plate, the bonding power of the rubber layers to the metal plate is further improved to obtain the superior durability for long use.
Moreover, the chromate treatment with the non-rinse chemical for chromate conversion used in the invention is easy in operation in comparison with the chemical reaction conversion and the electrolytic treatment. Furthermore, the chromate treatment has an advantage enabling thicknesses of the chromate films to adjust easily.
According to the invention as above described, by introducing the process of coating and drying the non-rinse chemical for chromate conversion, the bonding power of the rubber layer is increased to improve the sealing faculty and the durability of the metal gasket for automobiles without making difficult the operation in the production line.
Moreover, the invention is applicable to metal gaskets not only for automobiles but also screw engines, freezing equipment, air conditioning units and various industrial apparatuses.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details can be made therein without departing from the spirit and scope of the invention. | A method of producing a metal gasket includes steps of alkaline cleaning a metal plate, coating a non-rinse chemical for chromate conversion of surfaces of the metal plate and drying to form chromate films, coating an adhesive on the chromate films and drying or baking the adhesive to form adhesive layers, and coating rubber compound of a sheet-like or an amorphous mixed compound to a predetermined thickness on the adhesive layers and heating and vulcanizing the rubber compound to form rubber coated metal plate. A metal gasket manufactured in this manner has a high bonding power of the rubber layers to the metal plate to obtain an improved durability for long use. | 8 |
[0001] This application is a Divisional of co-pending application Ser. No. 11/221,898 filed on Sep. 9, 2005, which claims priority on Taiwan Application No. 94123341 filed Jul. 11, 2005. The entire contents of each of these applications is hereby incorporated by reference.
BACKGROUND
[0002] The present invention relates to a method for nanofiber fabrication, and more particularly to a method for fabricating nanofibers with controllable diameter.
[0003] Nanofibers are fibers having diameter less than 1 micrometer and have been developed for use in a wide range of applications such as high performance filters, drug delivery, scaffolds for tissue engineering, optical, and electronic applications, due to the advantages of increased specific surface area, extremely thin diameter, and super light weight.
[0004] In manufacture of nanofibers, the electrospinning process provides advantages of high productivity and continuous production, making it an industry choice. The nanofibers fabricated by conventional electrospinning, however, present a wide variation in configuration and diameter and have an average diameter not less than 800 nm. In other conventional electrospinning processes, lower feed rate or lower concentration of polymer solution, and larger distance between the nozzle and the receiving plate are suggested to decrease the average diameter of obtained nanofibers. The aforementioned electrospinning processes, however, fail to yield sufficient quantities of nanofibers.
[0005] As well, since the rheological properties and intramolecular interaction of polymer solutions depend on the characteristics and structure of the polymer molecules thereof, the variety of polymers applied to the conventional electrospinning processes is limited.
[0006] Accordingly, it is desirable to develop a novel electrospinning process, in which the variety of polymer sources is unlimited, to provide nanofibers of uniform configuration with reduced average diameter, further enabling mass production for common use.
SUMMARY
[0007] Embodiments of the invention provide a nanofiber comprising the products of electrospinning composition subjected to an electrospinning process, wherein the electrospinning composition comprises a polymer and an additive as a uniform solution in an organic solvent, and the additive renders the electronic characteristic of the polymer solution. Particularly, the embodiments provide nanofibers with an average diameter of 15˜500 nm, preferably 15˜250 nm, wherein no decrease of dope feeding rate or no decrease concentration of electrospinning composition is required in the process.
[0008] Embodiments of the invention further provide a method for fabricating nanofiber. An electrospinning composition is provided and subjected to an electrospinning process, wherein the electrospinning composition comprises a polymer and an additive as a uniform solution in an organic solvent, and the additive renders the unique electronic characteristic of the polymer.
[0009] A detailed description is given in the following with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention can be more fully understood by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein:
[0011] FIG. 1 is a SEM (scanning electron microscope) photograph of the polyvinyl alcohol nanofiber according to Comparative Example 1.
[0012] FIGS. 2˜6 are SEM (scanning electron microscope) photographs of the polyvinyl alcohol nanofiber according to Examples 1˜5.
[0013] FIG. 7 is a SEM (scanning electron microscope) photograph of the polystyrene nanofiber according to Comparative Example 2.
[0014] FIGS. 8˜10 are SEM (scanning electron microscope) photographs of the polystyrene nanofiber according to Examples 6˜8.
[0015] FIG. 11 is a SEM (scanning electron microscope) photograph of the polycarbonate nanofiber according to Comparative Example 3.
[0016] FIGS. 12˜15 are SEM (scanning electron microscope) photographs of the polycarbonate nanofiber according to Examples 9˜12.
[0017] FIG. 16 is a SEM (scanning electron microscope) photograph of the polyvinylidene fluoride nanofiber according to Comparative Example 4.
[0018] FIGS. 17˜19 are SEM (scanning electron microscope) photographs of the polyvinylidene fluoride nanofiber according to Examples 13˜15.
[0019] FIG. 20 is a SEM (scanning electron microscope) photograph of the polyvinylidene fluoride hexafluoropropylene nanofiber according to Comparative Example 5.
[0020] FIGS. 21˜22 are SEM (scanning electron microscope) photographs of the polyvinylidene fluoride hexafluoropropylene nanofiber according to Examples 16˜17.
[0021] FIG. 23 is a SEM (scanning electron microscope) photograph of the polyvinylidene fluoride hexafluoropropylene nanofiber according to Comparative Example 6.
[0022] FIGS. 24˜26 are SEM (scanning electron microscope) photographs of the polyvinylidene fluoride hexafluoropropylene nanofiber according to Examples 18˜20.
DETAILED DESCRIPTION
[0023] According to embodiments of the invention, the electrospinning composition comprises a polymer and an additive as a uniform solution in water or an organic solvent. As a main feature and a key aspect, the additive used in embodiments of the invention is selected to render the electronic characteristic of the polymer solution.
[0024] In embodiments of the invention, the polymer can comprise water-soluble polymer, solvent-soluble polymer, biopolymer or combinations thereof, such as polyethylene, polyvinyl alcohol, sodium alginate, gelatin, collagen, polystyrene, polycarbonate, chitosan, fluorine polymer, polyester, polyamide, or polyimide.
[0025] In embodiments of the invention, the additive can comprise organic or inorganic salt, organic or inorganic acid, organic or inorganic base, polar compound, oligomer (C 1-18 ) or combinations thereof. Particularly, the additive is an electrolyte comprising organic or inorganic salts. Preferably, the organic or inorganic salt can comprise fluorine salt, chlorine salt, bromine salt, iodine salt, sulfate salt, nitrate salt, carboxylate salt, oxalate salt, borate salt, sulfonate salt, perchlorate salt, citrate salt, lithium salt, sodium salt, potassium salt, beryllium salt, calcium salt, aluminum salt, magnesium salt, titanium salt, or combinations thereof. Preferably, the organic acid, inorganic acid, organic base, or inorganic base can be monoacid, polyacid, monobase, or polybase, comprising C 1-18 carboxylic acid, C 1-18 alcohol, ammonia, imidazole, metal hydroxyl compound, hydrochloric acid, nitric acid, boric acid, perchloric acid, sulfuric acid, phosphoric acid, lactic acid, benzoic acid, or citric acid. Preferably, the polar compound can comprise pyridine, formamide, dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, valerolactam, caprolactam, o-dichlorobenzene, tetramethylurea, acetonitrile, or combinations thereof, more preferably pyridine. It should be noted that the additive is present in an amount of 0.01 wt % to 15 wt % of the electrospinning composition, preferably 0.05 wt % to 12 wt %, more preferably 0.1 wt % to 10 wt %.
[0026] The electrospinning composition is loaded into a spinneret to perform an electrospinning process. Since the additive enhances the electronic characteristic of the polymer solution, the average diameter of obtained nanofiber can be reduced to 15˜500 nm without decreasing the feed rate or the concentration of electrospinning composition, or increasing the distance between nozzle and receiving plate of the spinneret. The electrospinning process can have an applied voltage of 20˜50 KV and employ a spinneret with a distance from a needle tip to a receiving plate of 10˜30 cm, preferably less than 20 cm. Moreover, in embodiments of the invention, the feed rate of electrospinning composition in the electrospinning process can be more than 10 μl/min per nozzle.
[0027] The following examples are intended to demonstrate the invention more fully without limiting its scope, since numerous modifications and variations will be apparent to those skilled in the art.
COMPARATIVE EXAMPLE 1
[0028] Polyvinyl alcohol powder (molecular weight: 88000 g/mol and chemical purity >99.5%) was dissolved in water at 80° C. to prepare a solution with 10 wt % polyvinyl alcohol. After cooling to room temperature, the polyvinyl alcohol solution was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the polyvinyl alcohol solution 15 μl/min. The deposit was cut and polyvinyl alcohol nanofiber obtained at the receiving plate. The polyvinyl alcohol nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 1 . The average diameter thereof was then further measured, and the result is shown in Table 1.
EXAMPLE 1
[0029] Polyvinyl alcohol powder (molecular weight: 88000 g/mol and chemical purity >99.5%) was dissolved in water at 80° C. to prepare a solution with 10 wt % polyvinyl alcohol. After cooling to room temperature, acetic acid was added into the above solution to prepare an electrospinning composition, wherein the acetic acid was present in an amount of 5 wt % of the electrospinning composition. After mixing completely, the electrospinning composition was loaded into a spinneret. Particularly, the applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the electrospinning composition 15 μl/min. The deposit was cut and polyvinyl alcohol nanofiber obtained at the receiving plate. The polyvinyl alcohol nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 2 . The average diameter thereof was then further measured, and the result is shown in Table 1.
EXAMPLE 2
[0030] Example 2 was performed the same as Example 1 with the exception of substitution of 5 wt % acetic acid with 10 wt % acrylic acid to prepare the electrospinning composition. The obtained polyvinyl alcohol nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 3 . The average diameter thereof was then further measured, and the result is shown in Table 1.
EXAMPLE 3
[0031] Example 3 was performed the same as Example 1 with the exception of substitution of 5 wt % acetic acid with 2.4 wt % adipic acid to prepare the electrospinning composition. The obtained polyvinyl alcohol nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 4 . The average diameter thereof was then further measured, and the result is shown in Table 1.
EXAMPLE 4
[0032] Example 4 was performed the same as Example 1 with the exception of substitution of 5 wt % acetic acid with 5 wt % ethanol to prepare the electrospinning composition. The obtained polyvinyl alcohol nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 5 . The average diameter thereof was then further measured, and the result is shown in Table 1.
EXAMPLE 5
[0033] Example 5 was performed the same as Example 1 with the exception of substitution of 5 wt % acetic acid with 0.5 wt % water-soluble titania to prepare the electrospinning composition. The obtained polyvinyl alcohol nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 6 . The average diameter thereof was then further measured, and the result is shown in Table 1.
[0000]
TABLE 1
average diameter of polyvinyl alcohol nanofiber
Average diameter
Conventional wet
>30
μm
spinning
Comparative Example 1
270
nm
Example 1
50
nm
Example 2
68
nm
Example 3
51
nm
Example 4
150
nm
Example 5
186
nm
COMPARATIVE EXAMPLE 2
[0034] Polystyrene pellet (molecular weight: 170000 g/mol) was dissolved in dimethylacetamide to prepare a solution with 10 wt % polystyrene. The polystyrene solution was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the polystyrene solution 15 μl/min. The deposit was cut and polystyrene nanofibers obtained at the receiving plate. The polystyrene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 7 . The average diameter thereof was then further measured, and the result is shown in Table 2.
EXAMPLE 6
[0035] Polystyrene pellet (molecular weight: 170000 g/mol) was dissolved in dimethylacetamide to prepare a solution with 10 wt % polystyrene. Acetic acid was added into the above solution to prepare an electrospinning composition, wherein the acetic acid was present in an amount of 0.14 wt % of the electrospinning composition. After mixing completely, the electrospinning composition was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the electrospinning composition 15 μl/min. The deposit was cut and polystyrene nanofiber obtained at the receiving plate. The polystyrene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 8 . The average diameter thereof was then further measured, and the result is shown in Table 2.
EXAMPLE 7
[0036] Example 7 was performed the same as Example 6 with the exception of substitution of 0.14 wt % acetic acid with 0.2 wt % pyridine to prepare the electrospinning composition. The obtained polystyrene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 9 . The average diameter thereof was then further measured, and the result is shown in Table 2.
EXAMPLE 8
[0037] Example 8 was performed the same as Example 6 with the exception of substitution of 0.14 wt % acetic acid with 0.1 wt % lithium chloride to prepare the electrospinning composition. The obtained polystyrene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 10 . The average diameter thereof was then further measured, and the result is shown in Table 2.
[0000]
TABLE 2
average diameter of polystyrene nanofiber
Average diameter (nm)
conventional spinning
Nanofiber not obtained
Comparative Example 2
250
Example 6
160
Example 7
165
Example 8
104
COMPARATIVE EXAMPLE 3
[0038] Polycarbonate pellet (molecular weight: 26000 g/mol) was dissolved in chloroform to prepare a solution with 10 wt % polycarbonate. The polycarbonate solution was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the polycarbonate solution 15 μl/min. The deposit was cut and polystyrene nanofibers obtained at the receiving plate. The polystyrene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 11 . The average diameter thereof was then further measured, and the result is shown in Table 3.
EXAMPLE 9
[0039] Polycarbonate pellet (molecular weight: 26000 g/mol) was dissolved in chloroform to prepare a solution with 10 wt % polycarbonate. Pyridine was added into the above solution to prepare an electrospinning composition, wherein the pyridine was present in an amount of 0.2 wt % of the electrospinning composition. After mixing completely, the electrospinning composition was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the electrospinning composition 15 μl/min. The deposit was cut and polycarbonate nanofiber obtained at the receiving plate. The polycarbonate nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 12 . The average diameter thereof was then further measured, and the result is shown in Table 3.
EXAMPLE 10
[0040] Example 10 was performed the same as Example 9 with the exception of substitution of 0.2 wt % pyridine with 2.0 wt % dimethylacetamide to prepare the electrospinning composition. The obtained polycarbonate nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 13 . The average diameter thereof was then further measured, and the result is shown in Table 3.
EXAMPLE 11
[0041] Example 11 was performed the same as Example 9 with the exception of substitution of 0.2 wt % pyridine with 2.0 wt % dimethylacetamide and 0.4 % lithium chloride to prepare the electrospinning composition. The obtained polycarbonate nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 14 . The average diameter thereof was then further measured, and the result is shown in Table 3.
EXAMPLE 12
[0042] Example 12 was performed the same as Example 9 with the exception of substitution of 0.2 wt % pyridine with 4.0 wt % dimethylacetamide and 0.4 % lithium chloride to prepare the electrospinning composition. The obtained polycarbonate nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 15 . The average diameter thereof was then further measured, and the result is shown in Table 3.
[0000]
TABLE 3
average diameter of polycarbonate nanofiber
Average diameter (nm)
conventional spinning
Nanofiber not obtained
Comparative Example 3
1500
Example 9
300
Example 10
330
Example 11
480
Example 12
550
COMPARATIVE EXAMPLE 4
[0043] Polyvinylidene fluoride pellet (molecular weight: 64000 g/mol) was dissolved in dimethylacetamide to prepare a solution with 10 wt % polycarbonate. The polyvinylidene fluoride solution was loaded into a spinneret to perform an electrospinning process. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the polyvinylidene fluoride solution 15 μl/min. The deposit was cut and polyvinylidene fluoride nanofibers obtained at the receiving plate. The polyvinylidene fluoride nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 16 . The average diameter thereof was then further measured, and the result is shown in Table 4.
EXAMPLE 13
[0044] Polyvinylidene fluoride pellet (molecular weight: 64000 g/mol) was dissolved in dimethylacetamide to prepare a solution with 10 wt % polycarbonate. Lithium chloride was added into the above solution to prepare an electrospinning composition, wherein the lithium chloride was present in an amount of 0.5 wt % of the electrospinning composition. After mixing completely, the electrospinning composition was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the supply rate of the electrospinning composition 15 μl/min. The deposit was cut and polyvinylidene fluoride nanofibers obtained at the receiving plate. The polyvinylidene fluoride nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 17 . The average diameter thereof was then further measured, and the result is shown in Table 4.
EXAMPLE 14
[0045] Example 14 was performed the same as Example 13 with the exception of substitution of 0.5 wt % lithium chloride with 0.5 wt % lithium chloride and 0.14 wt % acetic acid to prepare the electrospinning composition. The obtained polyvinylidene fluoride nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 18 . The average diameter thereof was then further measured, and the result is shown in Table 4.
EXAMPLE 15
[0046] Example 15 was performed the same as Example 13 with the exception of substitution of 0.5 wt % lithium chloride with 0.5 wt % lithium chloride and 0.2 wt % pyridine to prepare the electrospinning composition. The obtained polyvinylidene fluoride nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 19 . The average diameter thereof was then further measured, and the result is shown in Table 4.
[0000]
TABLE 4
average diameter of polyvinylidene fluoride nanofiber
Average diameter (nm)
Conventional spinning
Nanofiber not obtained
Comparative Example 4
1500
Example 13
300
Example 14
330
Example 15
480
COMPARATIVE EXAMPLE 5
[0047] Polyvinylidene fluoride hexafluoropropylene copolymer powder (molecular weight: 64000 g/mol) was dissolved in acetone to prepare a solution with 10 wt % polyvinylidene fluoride hexafluoropropylene copolymer. Polyvinylidene fluoride hexafluoropropylene solution was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the polyvinylidene fluoride hexafluoropropylene solution 15 μl/min. The deposit was cut and polyvinylidene fluoride-hexafluoropropylene nanofibers obtained at the receiving plate. The polyvinylidene fluoride hexafluoropropylene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIGS. 20 . The average diameter thereof was then further measured, and the result is shown in Table 5.
EXAMPLE 16
[0048] Polyvinylidene fluoride hexafluoropropylene copolymer powder (molecular weight: 64000 g/mol) was dissolved in acetone to prepare a solution with 10 wt % polyvinylidene fluoride hexafluoropropylene copolymer. Acetic acid, serving as additive, was added into the above solution to prepare an electrospinning composition, wherein the acetic acid was present in an amount of 0.14 wt % of the electrospinning composition. After mixing completely, the electrospinning composition was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the supply rate of the electrospinning composition 15 μl/min. The deposit was cut and polyvinylidene fluoride hexafluoropropylene nanofibers obtained at the receiving plate. The polyvinylidene fluoride hexafluoropropylene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 21 . The average diameter thereof was then further measured, and the result is shown in Table 5.
EXAMPLE 17
[0049] Example 17 was performed the same as Example 13 with the exception of substitution of 0.14 wt % pyridine with 0.14 wt % acetic acid to prepare the electrospinning composition. The obtained polyvinylidene fluoride hexafluoropropylene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 22 . The average diameter thereof is then further measured, and the result was shown in Table 5.
COMPARATIVE EXAMPLE 6
[0050] Comparative Example 6 was performed the same as comparative Example 5 with the exception of substitution of dimethylacetamide for acetone as solvent. The obtained polyvinylidene fluoride hexafluoropropylene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 23 . The average diameter thereof was then further measured, and the result is shown in Table 5.
EXAMPLE 18
[0051] Polyvinylidene fluoride hexafluoropropylene copolymer powder (molecular weight: 64000 g/mol) was dissolved in dimethylacetamide to prepare a solution with 10 wt % polyvinylidene fluoride hexafluoropropylene copolymer. Acetic acid was added into the above solution to prepare an electrospinning composition, wherein the acetic acid was presence in an amount of 0.14 wt % of the electrospinning composition. After mixing completely, the electrospinning composition was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the electrospinning composition 15 μl/min. The deposit was cut and polyvinylidene fluoride hexafluoropropylene nanofibers obtained at the receiving plate. The polyvinylidene fluoride hexafluoropropylene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 24 . The average diameter thereof was then further measured, and the result is shown in Table 5.
EXAMPLE 19
[0052] Example 19 was performed the same as Example 18 with the exception of substitution of 0.20 wt % pyridine with 0.14 wt % acetic acid to prepare the electrospinning composition. The obtained polyvinylidene fluoride hexafluoropropylene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 25 . The average diameter thereof was then further measured, and the result is shown in Table 5.
EXAMPLE 20
[0053] Example 20 was performed the same as Example 18 with the exception of substitution of 0.5 wt % lithium chloride with 0.14 wt % acetic acid to prepare the electrospinning composition. The obtained polyvinylidene fluoride hexafluoropropylene nanofiber was identified by scanning electron microscopy (SEM) as shown in FIG. 26 . The average diameter thereof was then further measured, and the result is shown in Table 5.
[0000]
TABLE 5
average diameter of polyvinylidene fluoride
hexafluoropropylene nanofiber.
Average diameter (nm)
Conventional spinning
Nanofiber not obtained
Comparative Example 5
550
Example 16
350
Example 17
400
Comparative Example 6
80
Example 18
54
Example 19
60
Example 20
33
EXAMPLE 21
[0054] Collagen freeze-dried powder (extracted from animal and dried) was dissolved in water at 25° C. to prepare a solution with 3 wt % collagen. Hydrogen chloride was added into the above solution to prepare an electrospinning composition, wherein the hydrogen chloride was presence in an amount of 0.05 wt % of the electrospinning composition. After mixing completely, the electrospinning composition was loaded into a spinneret. The applied voltage of the electrospinning process was 40 KV, the diameter of the nozzle 0.4 mm, the distance between the nozzle to the receiving plate 20 cm, and the feed rate of the electrospinning composition 15 μl/min. The deposit was cut and collagen nanofibers obtained at the receiving plate. The average diameter of the collagen nanofiber is 100 nm.
[0055] Use of the additives disclosed the polymer suitable for use in the electrospinning composition is not limited, and includes the polymers not suitable for conventional electrospinning such as biopolymer. The same solvent and polymer components generate nanofiber, fabricated from electrospinning composition in the absence of the additive as disclosed, with average diameter of 300˜1500 nm (referring to Comparative Examples 1˜6), and the nanofiber fabricated from electrospinning composition in the presence of the additive as disclosed has an average diameter of 50˜500 nm (referring to Examples 1˜20). Accordingly, the nanofiber of the invention is 60%˜85% thinner than that obtained by conventional electrospinning. Moreover, since the electrospinning process of the invention utilizes conventional electrospinning spinnerets and is performed with unlimited supply rate and concentration of electrospinning composition, the invention readily provides at high throughput and yield compared with conventional electrospinning.
[0056] While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. It is therefore intended that the following claims be interpreted as covering all such alteration and modifications as fall within the true spirit and scope of the invention. | A nanofiber and fabrication methods thereof. The method for fabricating the nanofiber includes preparing an electrospinning composition and performing an electrospinning process employing the electrospinning composition. Particularly, the electrospinning composition includes a polymer and an additive as a uniform solution in an organic solvent, wherein the additive renders the electronic characteristic of the polymer. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional application of U.S. non-provisional application Ser. No. 11/825,567, filed 6 Jul. 2007, now U.S. Pat. No. 7,459,924 entitled “Methods And Apparatus For Planar Extension Of Electrical Conductors Beyond The Edges Of A Substrate”, which claimed the benefit of provisional application 60/819,318, filed 7 Jul. 2006, entitled “Methods And Apparatus For Planar Extension Of Electrical Conductors Beyond The Edges Of A Substrate”, the entirety of each is hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates generally to semiconductor test equipment, and more particularly relates to methods and apparatus for routing electrical conductors to and from integrated circuits, microelectromechanical systems (MEMS), or similar structures in a test environment.
BACKGROUND
Advances in semiconductor manufacturing technology have resulted in, among other things, reducing the cost of sophisticated electronics to the extent that integrated circuits have become ubiquitous in the modern environment.
As is well-known, integrated circuits are typically manufactured in batches, and these batches usually contain a plurality of semiconductor wafers within and upon which integrated circuits are formed through a variety of semiconductor manufacturing steps, including, for example, depositing, masking, patterning, implanting, etching, planarizing, and so on.
Completed wafers are tested to determine which die, or integrated circuits, on the wafer are capable of operating according to predetermined specifications. In this way, integrated circuits that cannot perform as desired are not packaged, or otherwise incorporated into finished products.
It is common to manufacture integrated circuits on roughly circular semiconductor substrates, or wafers. Further, it is common to form such integrated circuits so that conductive regions disposed on, or close to, the uppermost layers of the integrated circuits are available to act as terminals for connection to various electrical elements disposed in, or on, the lower layers of those integrated circuits. In testing, these conductive regions are commonly contacted with a probe card.
With respect to probe card technology, the maintenance of probe tip accuracy, good signal integrity, and overall dimensional accuracy severely strains even the best of these highly developed fabrication methods because of the multiple component and assembly error budget entries for such assemblies.
What is needed are lower-cost, less-complex apparatus and methods to increase test efficiency.
SUMMARY OF THE INVENTION
Briefly, concurrent electrical access to the pads of integrated circuits on a wafer is provided by an edge-extended wafer translator that carries signals from one or more pads on one or more integrated circuits to contact terminals on the inquiry-side (i.e., the non-wafer-side) of the edge-extended wafer translator, including portions of the inquiry-side that are superjacent the wafer when the wafer and the edge-extended wafer translator are in a removably attached state, and portions of the inquiry side that reside outside a region defined by the intersection of the wafer and the edge-extended wafer translator.
In a further aspect of the present invention, access to the pads of integrated circuits on a wafer is additionally provided by contact terminals in a second inquiry area located on the wafer-side of the edge-extended wafer translator in a region thereof bounded by its outer circumference and the circumference of the attached wafer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional representation of a wafer and an edge-extended wafer translator in a removably attached state, with a gasket disposed between the wafer and the edge-extended wafer translator, forming an assembly having conductive pathways extending beyond the edges of the wafer, and coupled to conductive pads disposed on the inquiry-side the edge-extended wafer translator.
FIG. 2 is a schematic cross-sectional representation of a wafer and an edge-extended wafer translator in a removably attached state, with a gasket disposed between the wafer and the edge-extended wafer translator, forming an assembly having conductive pathways extending beyond the edges of the wafer, and coupled to conductive pads disposed on both the inquiry-side and the wafer-side of the edge-extended wafer translator.
FIG. 3 is a top view of an edge-extended wafer translator wherein wire paths extend past from the circumferential edge of a wafer in one direction (perpendicular to a diameter of the wafer in the illustrated embodiment), to electrically conductive pads disposed on the inquiry-side of the edge-extended wafer translator.
FIG. 4 is a top view of an edge-extended wafer translator wherein wire paths extend past the circumferential edge of a wafer in more than one direction.
FIG. 5 is a cross-sectional view of a portion of a wafer and an edge-extended wafer translator wherein some wire paths of the edge-extended wafer translator lead away from the edge of a wafer, while other wire paths lead to pads disposed superjacent an area defined by the wafer.
FIG. 6 is a top-view of an edge-extended wafer translator in which some wire paths extend beyond the edge of a wafer in a single direction, while other conductive pathways contact pads disposed within an area defined by the wafer.
DETAILED DESCRIPTION
Reference herein to “one embodiment”, “an embodiment”, or similar formulations, means that a particular feature, structure, operation, or characteristic described in connection with the embodiment, is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or formulations herein are not necessarily all referring to the same embodiment. Furthermore, various particular features, structures, operations, or characteristics may be combined in any suitable manner in one or more embodiments.
Terminology
Reference herein to “circuit boards”, unless otherwise noted, is intended to include any type of substrate upon which circuits may be placed. For example, such substrates may be rigid or flexible, ceramic, flex, epoxy, FR4, or any other suitable material.
Pad refers to a metallized region of the surface of an integrated circuit, which is used to form a physical connection terminal for communicating signals to and/or from the integrated circuit.
The expression “wafer translator” refers to an apparatus facilitating the connection of pads (sometimes referred to as terminals, I/O pads, contact pads, bond pads, bonding pads, chip pads, test pads, or similar formulations) of unsingulated integrated circuits, to other electrical components. It will be appreciated that “I/O pads” is a general term, and that the present invention is not limited with regard to whether a particular pad of an integrated circuit is part of an input, output, or input/output circuit. A wafer translator is typically disposed between a wafer and other electrical components, and/or electrical connection pathways. The wafer translator is typically removably attached to the wafer (alternatively the wafer is removably attached to the translator). The wafer translator includes a substrate having two major surfaces, each surface having terminals disposed thereon, and electrical pathways disposed through the substrate of the wafer translator to provide for electrical continuity between at least one terminal on a first surface and at least one terminal on a second surface. The wafer-side of the wafer translator has a pattern of terminals that matches the layout of at least a portion of the pads of the integrated circuits on the wafer. The wafer translator, when disposed between a wafer and other electrical components such as an inquiry system interface, makes electrical contact with one or more pads of a plurality of integrated circuits on the wafer, providing an electrical pathway therethrough to the other electrical components. The wafer translator is a structure that is used to achieve electrical connection between one or more electrical terminals that have been fabricated at a first scale, or dimension, and a corresponding set of electrical terminals that have been fabricated at a second scale, or dimension. The wafer translator provides an electrical bridge between the smallest features in one technology (e.g., pins of a probe card) and the largest features in another technology (e.g., bonding pads of an integrated circuit). For convenience, wafer translator is referred to simply as translator where there is no ambiguity as to its intended meaning. In some embodiments a flexible wafer translator offers compliance to the surface of a wafer mounted on a rigid support, while in other embodiments, a wafer offers compliance to a rigid wafer translator. The surface of the translator that is configured to face the wafer in operation is referred to as the wafer-side of the translator. The surface of the translator that is configured to face away from the wafer is referred to as the inquiry-side of the translator. An alternative expression for inquiry-side is tester-side.
The expression “edge-extended wafer translator” refers to an embodiment of a translator in which electrical pathways disposed in and/or on the translator lead from terminals, which in use contact the wafer under test, to at least electrical terminals disposed outside of a circumferential edge of a wafer aligned for connection with, or attached to the edge-extended translator. These electrical terminals disposed outside of a circumferential edge of an attached wafer may be disposed on the inquiry-side and/or the wafer-side of the edge-extended wafer translator.
The expression “translated wafer” refers to a wafer that has a wafer translator attached thereto, wherein a predetermined portion of, or all of, the contact pads of the integrated circuits on the wafer are in electrical contact with corresponding electrical connection means disposed on the wafer side of the translator. Typically, the wafer translator is removably attached to the wafer. Alternatively, it may be said that the wafer is removably attached to the wafer translator, or that the wafer/wafer translator pair are removably attached to each other. In a further alternative, it may be said that the wafer and wafer translator are disposed in an attached state, and the attached state may be further qualified by indicating whether the attached state is permanent or temporary. Removable attachment may be achieved, for example, by means of vacuum, or pressure differential, attachment.
The terms chip, integrated circuit, semiconductor device, and microelectronic device are sometimes used interchangeably in this field. The present invention relates to the manufacture and test of chips, integrated circuits, semiconductor devices and microelectronic devices as these terms are commonly understood in the field.
FIG. 1 is a schematic cross-sectional representation of an assembly 100 of an edge-extended wafer translator 102 and wafer 104 . The illustrative edge-extended wafer translator of FIG. 1 is substantially planar. A plurality of electrically conductive pads 106 disposed on the top surface of wafer 104 are brought into contact with a corresponding plurality of electrically conductive pads 108 disposed on the wafer-side surface of edge-extended wafer translator 102 . The wafer and edge-extended wafer translator are typically removably attached to each other by means of a vacuum, or pressure differential, formed between the wafer, edge-extended wafer translator, and a gasket 110 . In this illustrative embodiment, a plurality of wire paths 112 disposed within edge-extended wafer translator 102 lead from conductive pads 108 to a plurality of conductive pads 114 disposed on the inquiry-side of edge-extended wafer translator 102 . It is noted that alternative arrangements for removably attaching the wafer and edge-extended wafer translator are contemplated by the present invention.
FIG. 2 is a schematic cross-sectional representation of a planar edge-extended wafer translator 202 and a wafer 204 aligned for attachment to form assembly 200 . It can be seen that edge-extended wafer translator 202 has two major surfaces, one which faces towards wafer 204 and is referred to as the wafer-side of edge-extended wafer translator 202 ; and one which faces away from wafer 204 and is referred to as the inquiry-side, or non-wafer-side, of the edge-extended wafer translator. Conductive pads 214 disposed on the inquiry-side are typically used to make connections with test equipment, but are not limited to such connections. Conductive pads 222 disposed on the wafer-side are also typically used to make connections with test equipment, but are not limited to such connections. It is noted that, since edge-extended wafer translator 202 extends beyond the edges of wafer 204 , there is surface area of the wafer-side that is not covered by wafer 204 , and therefore this area is available for pads and connections with other electronic devices and equipment. In the illustrated embodiment, an annular region of the wafer-side of edge-extended wafer translator 202 , bounded by its outer circumference and the circumference of wafer 204 , is available for conductive pads which may be coupled to other electrical nodes via wire paths disposed within and/or upon edge-extended wafer translator 202 .
Still referring to FIG. 2 , electrically conductive pads 214 , 222 are disposed on both of the major surfaces of edge-extended wafer translator 202 . A plurality of electrically conductive pads 206 , 216 disposed on the top-side of wafer 204 are brought into contact with a corresponding plurality of electrically conductive pads 208 , 218 disposed on the wafer-side surface of PE translator 202 . Removable attachment of edge-extended wafer translator 202 and wafer 204 may be accomplished by means of vacuum, or pressure differential, between the atmosphere and the space bounded by edge-extended wafer translator 202 , wafer 204 , and a gasket 210 . In this embodiment, a plurality of wire paths 212 disposed within edge-extended wafer translator 202 lead from conductive pads 208 to a plurality of conductive pads 214 disposed on the inquiry-side of edge-extended wafer translator 202 . A plurality of wire paths 220 , disposed within edge-extended wafer translator 202 , lead from conductive pads 218 to a plurality of conductive pads 222 disposed on the portion of the wafer-side of edge-extended wafer translator 202 that is not covered by wafer 204 .
FIG. 3 is a schematic top view of an embodiment of an edge-extended wafer translator 300 with a D-shaped form factor, wherein a plurality of conductive pathways 302 extend beyond the circumferential edge 306 of a wafer in a single direction (i.e., perpendicular to a diameter of the wafer contact area). The plurality of conductive pathways 302 contact a plurality of electrically conductive pads disposed on the inquiry-side of edge-extended wafer translator 300 . It is noted that in alternative embodiments, conductive pathways may extend beyond the circumferential margin of a wafer in more than one direction, and that an edge-extended wafer translator may exhibit any form factor, such as, but not limited to, a circle, square or rectangle (as shown in FIG. 4 ).
FIG. 4 is a schematic top view of an alternative embodiment of an edge-extended wafer translator 300 A with a rectangular form factor, wherein conductive pathways 302 A extend beyond the circumferential margin 306 A of a wafer in two directions, contacting a plurality of electrically conductive pads 304 A disposed on the inquiry-side of edge-extended wafer translator 300 A.
FIG. 5 is a close-up, schematic cross-sectional view of an edge-extended wafer translator 402 in accordance with the present invention, wherein wire paths 404 , 422 lead to electrically conductive pads disposed both within and without the circumferential margin of wafer 428 . Wire paths 404 contact electrically conductive pads 424 , disposed on the wafer-side of edge-extended wafer translator 402 , and lead beyond the circumferential edge of wafer 428 , to contact a plurality of electrically conductive pads disposed on the inquiry-side of edge-extended wafer translator 402 , as shown in FIG. 6 . Wire paths 422 contact electrically conductive pads 426 disposed on the wafer-side of edge-extended wafer translator 404 , and lead to pads 408 disposed on the inquiry-side of edge-extended wafer translator 404 within the circumferential margin of wafer 420 .
FIG. 6 is a schematic top view of an edge-extended wafer translator 500 , in accordance with the present invention, wherein conductive pathways 502 extend beyond the circumferential edge 506 of a wafer, contacting a plurality of electrically conductive pads 504 disposed on the non-wafer-side of PE translator 500 . Electrical paths (such as those depicted in FIG. 5 ) contact a plurality of electrically conductive pads 508 disposed on the non-wafer-side of PE translator 500 within the circumferential margin of the wafer. It is noted that in alternative embodiments, an edge-extended wafer translator with electrically conductive pads disposed both within and without the circumferential margin of a wafer may exhibit any form factor, such as, but not limited to, a circle, square, or rectangle.
An edge-extended wafer translator, as illustrated in FIGS. 1-6 , provides an electrical interface between the translated wafer and a test system (not shown). Such a test system may provide power and signals to the device under test, and may further receive signals from the device under test. Such a system may alternatively serve to plug a wafer full of processors into a computer system; mesh routing may be facilitated by edge-extended wafer translators.
Apparatus in accordance with the present invention are suitable for providing electrical connections between a first set of pads on at least one die of a wafer and a corresponding second set of pads disposed on an insulating body removably attached to that wafer. More particularly, the insulating body has a form factor such that, when attached to the wafer, a portion of the insulating body extends beyond the area defined by the wafer. At least portions of the second set of pads may be disposed on portions of the wafer-side of the insulating body that are not covered by the attached wafer; may be disposed on portions of the inquiry-side of the insulating body that extend beyond the area defined by the wafer; may be disposed on portions of the non-wafer side of insulating body that are superjacent the wafer attachment area; and may be disposed in any combination of the foregoing.
An illustrative method of providing electrical access to one or more pads of one or more integrated circuits on a wafer, in accordance with the present invention, includes providing an edge-extended wafer translator having a wafer-side and an inquiry-side, a first plurality of contact terminals disposed on a first portion of the wafer-side, a second plurality of contact terminals disposed on a second portion of the wafer-side, a third plurality of contact terminals disposed on a first portion of the inquiry-side, and a fourth plurality of contact terminals disposed on a second portion the inquiry-side; aligning the wafer and the edge-extended wafer translator to each other; and removably attaching the aligned wafer and edge-extended wafer translator such that the first plurality of contact terminals are in electrical contact with the one or more pads of the one or more integrated circuits; wherein the second portion of the wafer-side is an area outside the region where the wafer is removably attached to the edge-extended wafer translator, and wherein the first plurality of contact terminals and the second plurality of contact terminals have different contact areas and different spacing therebetween.
CONCLUSION
The exemplary methods and apparatus illustrated and described herein find application in the field of integrated circuit test and analysis.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the subjoined Claims and their equivalents. | Concurrent electrical access to the pads of integrated circuits on a wafer is provided by an edge-extended wafer translator that carries signals from one or more pads on one or more integrated circuits to contact terminals on the inquiry-side of the edge-extended wafer translator, including portions of the inquiry-side that are superjacent the wafer when the wafer and the edge-extended wafer translator are in a removably attached state, and portions of the inquiry side that reside outside a region defined by the intersection of the wafer and the edge-extended wafer translator. In a further aspect of the present invention, access to the pads of integrated circuits on a wafer is additionally provided by contact terminals in a second inquiry area located on the wafer-side of the edge-extended wafer translator in a region thereof bounded by its outer circumference and the circumference of the attached wafer. | 6 |
[0001] This is a divisional of U.S. application Ser. No. 10/683,204, filed on Oct. 9, 2003, issuing as U.S. Pat. No. 8,136,233 on Mar. 20, 2012, which is incorporated by reference herein. The present invention relates to connector tools for seating connectors on a substrate such as a printed circuit board (PCB).
BACKGROUND
[0002] Connectors are used for data transfer interfaces in computers, buses, servers, and storage and networking systems. Some examples of connectors include the Tyco/AMP Z-PACK HS3 Backplane Connectors, the 2 mm hard metric connectors and the 2 mm VHDM connectors from Tyco/AMP, Molex, Erni, and FCI.
[0003] The long, small diameter pins of these connectors may have gold plating to improve conductivity and performance at high frequencies and for corrosion protection. Care is required to prevent damage to the pins and the plating when seating the connector on a PCB. If the connector does not seat, extracting and reseating connector may destroy the connector, damage the vias (i.e., the holes in the PCB) and any thin conductive traces in nearby vias.
[0004] A single connector tool mounted on a tool press controlled by computer numerical controlled (CNC) seats the connectors. However, multiple connector tools can be mounted on the tool press in rows so all connectors are seated onto the PCB in a single press operation. Thus, more than one connector can be damaged in a single seating operation.
[0005] Connector tools have delicate structures that are machined to tight tolerance and are typically made of high strength material such as heat treated tool steel. Despite use of high strength material, the delicate structures are susceptible to damage if dropped during a tool change or transportation.
[0006] To understand the problems we now describe certain connector tools. FIG. 1A illustrates one conventional connector tool 10 that is used to seat the Tyco/AMP Z-PACK HS3 Backplane Connector and the 2 mm hard metric connectors. FIG. 1B is an enlarged view of the thin end wall 22 of the connector tool 10 shown in FIG. 1A , while FIG. 1C is an enlarged view of the thin end wall 28 . FIG. 1D is a front view of the thin end wall 28 . Thin end walls 22 , 28 are vulnerable to damage if dropped on the floor, for example, during a tool change or transportation.
[0007] FIG. 2A illustrates a conventional connector seating tool 120 for a custom VDHM 6×10 (60-pin) connector made by Molex and Teradyne. FIG. 2B is a top view of the connector tool 120 . FIG. 2C is an enlarged view showing the individually machined pin holes such as hole 122 for mating with connector pins.
[0008] FIG. 3A is a perspective view of a conventional connector tool 170 used to seat the 2 mm hard metric connector shown in FIG. 10A . FIG. 3B is a front view showing a base 171 with two sets of spaced walls 173 , 175 protruding from the base. The spaced walls 173 , 175 define two slot arrays 177 , 179 that mate with the connector pins. The spaced walls 173 , 175 have thin outer end walls 178 , 180 and thin inner end walls 184 , 186 . The spaced walls 173 , 175 are spaced from each other by gap 176 . FIG. 3C is an enlarged view of the thin outer end wall 178 . FIG. 3D is an enlarged view of gap 176 , and the thin inner end walls 184 , 186 that are susceptible to damage.
[0009] FIG. 4A is a front view of a conventional connector tool 330 for seating the power connector 270 shown in FIG. 5A . FIG. 4B is a perspective view of the connector tool 330 showing the push shoulders such as push shoulder 336 that push on the seating areas such as area 286 of the power connector 270 in FIG. 5A . FIG. 4C is an enlarged view of tool ribs 338 , 340 for sliding into the slots such as slots 280 , 285 of the power connector 270 shown in FIG. 5A . Because this tool has no guiding structure, misalignment between the conventional connector tool 330 and the power connector 270 before the tool ribs 338 , 340 fully engage and slide into slots 280 , 285 can crush the power connector 270 on the PCB.
SUMMARY OF THE INVENTION
[0010] The present invention relates to connector tools for seating connectors on a substrate. In various embodiments, the connector tools can be made by the wire electrode discharge machining (WEDM) process. The connector tools include features such as reinforced ribbed end walls, ribbed internal walls, interconnected walls and contours that reduce tool and connector damage. The connector tools may include guiding structures that align the connector tool to the connector before seating the connector so that the connector tool aligns to the connector pins and body to avoid damage to the connector and/or the substrate. The connector tools may have guiding skirts and surfaces to capture the connector in position then seat the connector. Thus, the invention reduces connector and substrate damage during manufacturing, reduces tool damage, and lowers product costs by boosting manufacturing yields.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1A illustrates a conventional connector tool for a Tyco/Amp HS3 connector.
[0012] FIG. 1B is an enlarged view of the end wall and the adjacent walls of the connector tool shown in FIG. 1A .
[0013] FIG. 1C is an enlarged view of the opposite end wall and the adjacent walls of the connector tool shown in FIG. 1A .
[0014] FIG. 1D is a front view of the end wall and the adjacent walls of the connector tool shown in FIG. 1C .
[0015] FIG. 2A is a perspective view of a conventional connector tool used to seat a VDHM 6×10 (60-pin) connector.
[0016] FIG. 2B is a top view of the conventional connector tool shown in FIG. 2A .
[0017] FIG. 2C is an enlarged view of part of the conventional connector tool shown in FIG. 2B .
[0018] FIG. 3A is a perspective view of a conventional connector tool for seating a 2 mm hard metric connector.
[0019] FIG. 3B is a front view showing the thin end walls and a gap in the tool base separating the set of walls in the conventional connector tool shown in FIG. 3A .
[0020] FIG. 3C is an enlarged view of the end wall of the conventional connector tool shown in FIG. 3A .
[0021] FIG. 3D is an enlarged view of the gap between the two sets of walls of the conventional connector tool shown in FIG. 3A .
[0022] FIG. 4A is a front view of a conventional connector tool for the power connector shown in FIG. 5A .
[0023] FIG. 4B is a perspective view of the conventional connector tool shown in FIG. 4A .
[0024] FIG. 4C is an enlarged view of the inner wall of the conventional connector tool shown in FIG. 4B .
[0025] FIG. 5A is a perspective view of a power connector with slots.
[0026] FIG. 5B is a top view of the power connector shown in FIG. 5A .
[0027] FIG. 6A is a perspective view of a connector tool with ribbed end walls for a Tyco/Amp HS3 connector.
[0028] FIG. 6B is an enlarged view of the ribbed end wall of the connector tool shown in FIG. 6A .
[0029] FIG. 6C is an enlarged view of the ribbed outer surface of the end wall of the connector tool shown in FIG. 6A .
[0030] FIG. 6D is a front view of the ribbed outer end wall of the connector tool shown in FIG. 6C .
[0031] FIG. 7A is a perspective view of a connector, a conventional connector tool and a connector tool with interconnected walls and contour slots.
[0032] FIG. 7B is a detailed view of the connector tool with interconnected walls and contour slots shown in FIG. 7A .
[0033] FIG. 8A is a front view of the conventional connector tool for seating a connector alongside the connector tool with interconnected walls shown in FIG. 7A .
[0034] FIG. 8B illustrates and compares a conventional connector tool with brittle thin walls with the connector tool shown in FIG. 8A .
[0035] FIG. 8C is a bottom view of the connector tool shown in FIG. 8A .
[0036] FIG. 8D is a bottom view showing the connector pin arrays of FIG. 8A .
[0037] FIG. 9A is a perspective view of a connector tool with interconnected walls for a VHDM 60-pin connector.
[0038] FIG. 9B is a top view of the connector tool with interconnected walls shown in FIG. 9A .
[0039] FIG. 10A is a perspective view of a high pin density connector for a 2 mm hard metric connector.
[0040] FIG. 10B is a top view of the high pin density connector shown in FIG. 10A .
[0041] FIG. 10C illustrates the connector slots of the high pin density connector shown in FIG. 10A .
[0042] FIG. 11A is an exploded perspective view of a connector tool with strengthened end walls and guiding structures for seating a high pin density connector on a PCB.
[0043] FIG. 11B is an exploded end view of the connector tool with guiding structures for alignment when seating a connector.
[0044] FIG. 11C is an exploded front view of the connector tool with guiding structures seating the connector shown in FIG. 11A .
[0045] FIG. 12A is a perspective bottom view of a connector tool with reinforced end walls and guiding structures.
[0046] FIG. 12B is a bottom view of the connector tool shown in FIG. 12A .
[0047] FIG. 12C is an enlarged view of the interconnected outer end wall of the connector tool shown in FIG. 12A .
[0048] FIG. 12D is an enlarged view of the guiding structure and the interconnected inner end walls of the connector tool shown in FIG. 12A .
[0049] FIG. 13A is a front view of a connector tool with a guiding skirt structure for the power connector shown in FIG. 5A .
[0050] FIG. 13B is a side view of the connector tool shown in FIG. 13A .
[0051] FIG. 13C is a bottom view showing the guiding skirt structure in FIG. 13A .
[0052] FIG. 14A is a perspective view of the connector tool shown in FIG. 13A .
[0053] FIG. 14B is a detailed view showing the guiding skirt structure of the connector tool shown in FIG. 14A .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] The following description includes the best mode of carrying out the invention. The detailed description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is determined by reference to the claims.
[0055] We assign each part, even if structurally identical to another part, its own reference number to help distinguish where the part appears in the drawings. We use dashed circles to indicate the parts that are enlarged in separate Figures. The separate Figure is indicated by the reference number tied to the dashed circle.
[0056] FIG. 6A is a perspective view of a connector tool 30 that includes a machined structure that has intersecting slots such as slots 36 , 38 from wall-to-wall to mate with connector pins. In an embodiment, the machined structure is machined by WEDM. The connector tool 30 is used for the Tyco/AMP Z-PACK HS3 Backplane Connectors but the type of construction can be used on other connectors as well.
[0057] FIG. 6B is an enlarged view showing ribbed end walls 42 , 43 with ribs 31 , 33 and 35 on outer surface. The ribs 31 , 33 and 35 can be disposed on the outer, the inner or both surfaces to strengthen the end walls 42 , 43 .
[0058] FIG. 6C is an enlarged view of the ribbed end wall 48 and a push shoulder 44 on the top of wall 46 . The push shoulders contact the connector during seating onto a substrate. FIG. 6D is a front view of illustrative rib 37 that strengthens an end wall 48 without obstructing connector pins such as pin 153 shown in FIG. 10A being inserted into pin slot 47 . The ribbed end wall 48 helps to reduce breakage and warping when the tool is dropped on the floor and the like. The thickness, number and location of the rib(s) on a wall can vary. The rib(s) can be on the inside and/or outside surface of the end wall, and on any internal walls such as wall 46 as long as the rib(s) do not interfere with insertion of the mating pins, or alignment of the connector and the connector tool. This rib feature is applicable therefore to many connector tools.
[0059] FIG. 7A is a perspective of the bottom of a future buss 2 mm connector 50 built to the EIA-616 industry standard. The connector includes board side connector pins 54 and mating side connector pins 49 . Also shown is a conventional connector tool 58 which has wall-to-wall pin slots such as illustrative pin slot 51 . In contrast, the connector tool 60 shown has an array of contours such as H-shaped contours 75 , 81 with pin slots to mate with the connector pins. In addition, the conventional connector tool 58 , the end wall 76 and wall edges are susceptible to warping damage and breakage when the tool is dropped.
[0060] FIG. 7B is an enlarged view of the H-shaped contour 75 with pin slots 74 , 77 . Also shown are portions of two adjacent H-shaped contours. The H-shaped contour 81 below the H-shaped contour 75 has a pin slot 84 that aligns with the pin slot 77 . Similarly, the pin slot 82 aligns with the pin slot 74 . The pin slots 77 , 84 in H-shaped contours 75 , 81 therefore mate with the connector pins and eliminate the need for a wall-to-wall pin slot such as the pin slot 51 found in the conventional connector tool 58 . This machined structure provides therefore interconnected walls such as wall 53 that strengthen the connector tool 60 . The interconnected walls 55 and 57 also serve to strengthen the tool without obstructing the connector pins. Interconnected walls 53 , 55 , 57 , and 71 provide planar surfaces for seating the connector 50 on a substrate while the closed side wall 64 is beveled to reduce damage if the connector tool is dropped on the floor.
[0061] FIG. 8A is a front view of the conventional connector tool 58 for seating a connector 50 alongside the connector tool 60 having interconnected walls just described. FIG. 8B is an enlarged view of the pin slot 72 of the conventional connector tool 58 follows the insertion path 61 shown in FIG. 8A to accommodate the mating side connector pin array 49 (partially shown in FIG. 7A ). The push shoulder 68 follows the tool seating path 63 to seat the connector 50 onto the substrate such as PCB 86 . Each of the board side connector pins such as pin 54 has a collapsible spring eyelet 59 that collapses in diameter by deformation when forced through the smaller PCB Plated Thru Hole (PTH) 88 holding the connector 50 snugly in place. The brittle end wall 66 is vulnerable to damage due to its small thickness and the protrusion. In contrast, the connector tool 60 shown in FIG. 8B has no such protrusion and has a closed side wall 64 that keeps the tool from damaging its walls when accidentally dropped.
[0062] FIG. 8C is a bottom view of the connector tool 60 shown in FIGS. 7A and 8A . WEDM can be used to form the array of contours shown. WEDM has the advantages of machining very fine geometry deep into hard material such as tool steel within desired tolerances. A WEDM start hole 80 is first established before migrating to form a set of H-shaped pin slots such as slots 82 , 84 . The interconnected walls surrounding the slots 82 , 84 strengthen the connector tool 60 and provide increased seating surface compared to the conventional connector tool 58 . The end wall 78 and the closed side wall 64 are integral reducing warping damage and breakage if the tool is dropped. FIG. 8D shows the bottom view with connector pins such as pin 54 of the connector 50 that are to be seated into the PCB PTH 88 by the connector tool 60 .
[0063] FIG. 9A is a perspective view of an embodiment of a connector tool 90 . It can be used for example in seating a custom VDHM 6×10 (60-pin) connector made by Molex and Teradyne. FIG. 9B is an enlarged top view of the connector tool 90 shown in FIG. 9A . WEDM is used to form a crab-shaped contour 93 from starting location of the WEDM start hole 104 then migrating out to form contiguous pin slots 106 , 108 , 110 and 112 . WEDM also forms the recess 101 indicated by the light shading that aligns with pin slots 108 , 112 that are sandwiched by elevated shoulders 105 , 107 (darker shading). The elevated shoulders 105 , 107 form beveled sides 102 , 103 with the recess 101 to help guide the mating connector pins into pin slots 108 , 112 in case of slight misalignment between the tool and the connector. Slots such as slots 92 , 94 , 114 , and 116 are ground shield clearance slots for a VHDM connector (not shown). Thus, a crab-shaped contour 93 can replace four individual connector pin holes such as hole 122 shown in FIG. 2C .
[0064] FIG. 10A is a perspective view of a high density multi-pin connector 140 such as the 2 mm hard metric connector built to IEC-1076 standards with an array of connector pins such as pin 153 . Rows of reinforcement ribs such as rib 150 on each side of the wall are staggered with respect to the rows of connector pins such as pin 153 to increase connector rigidity. Connector 140 also has slots 142 , 144 that will be explained below in connection with FIG. 11B .
[0065] FIG. 10B is a top view showing an array of connector pins such as pins 141 , 143 , 145 , 146 , 147 , 149 and 151 , the slots 142 , 144 , and a connector polarity key such as pin zero 232 that is positioned to identify the connector. FIG. 10C is an enlarged view showing the connector walls 154 , 156 , 162 and 164 with chamfered corners forming the slots 142 , 144 .
[0066] FIG. 11A is a perspective view of a connector tool 200 with slotted outer end walls 220 , 221 and guiding structure 202 , 204 seating the high density multi-pin connector 140 described in FIG. 10A onto a substrate with connector pin vias such as via 212 in a substrate such as the PCB 210 . A number of slots 234 , 236 , and 238 are formed by WEDM to accommodate the end row of connector pins such as connector pin 237 .
[0067] FIG. 11B is an end view of FIG. 11A showing the guiding structures having protruding heads with chamfered edges 206 , 208 sliding through the connector slots 142 , 144 to seat the connector 140 onto the PCB 210 .
[0068] FIG. 11C is a front view of connector tool 200 shown in FIGS. 11A-11B . The slotted outer end wall 220 follows the pin insertion path 222 to accommodate the connector pin 230 that is to be seated into the PCB PTH 212 on the PCB 210 . The guiding structure 204 has a protruding head with chamfered edges 208 that follows path 223 into the slot 144 to align the connector 140 before seating the connector pins such as pin 230 and pin zero 232 onto the PCB 210 .
[0069] FIG. 12A is a perspective view of the connector tool 200 shown in FIGS. 11A-11C . The connector tool 200 includes a structure with a base 226 with two opposite sets of spaced walls 224 , 228 protruding from each end of the base. The two opposite sets of spaced walls 224 , 228 define slot arrays 260 , 261 . The slot arrays 260 , 261 include slotted outer end walls 220 , 221 and inner end walls 243 , 245 that are reinforced through interconnected structures.
[0070] Also is shown the protruding heads with chamfered edges 206 , 208 for connector alignment. FIG. 12B is a bottom view of the connector tool 200 shown in FIG. 12A .
[0071] FIG. 12C is an enlarged view of the slotted outer end wall 220 which is no longer a thin wall susceptible to warping and breaking if accidentally dropped. Instead the slotted outer end wall 220 is adjoined to the adjacent inner wall 266 . A plurality of pin slots 234 , 236 , and 238 can be formed using WEDM so as to accommodate the end row connector pins such as pin 237 shown in FIG. 11A . The starting location of the WEDM start holes are holes 251 , 253 , and 255 . It is not important that the pin slots 234 , 236 and 238 be perforated from top to bottom since blind slotting with sufficient depth will accommodate the end row connector pins. The slotted outer end wall 220 maintains its strength and integrity through the adjoining interconnected structures 246 , 248 , 250 , and 252 that may extend partially or fully into the base 226 . Slots such as slot 262 provide clearance for the connector ribs such as rib 150 shown in FIG. 10A and pin slot 264 accommodates the mating connector pin.
[0072] FIG. 12D is an enlarged view showing the protruding heads with chamfered edges 206 , 208 that align the connector tool 200 with the connector slots 142 , 144 shown in FIG. 11B . The opposite inner end walls 243 , 245 are strengthened by adjoining to a common interconnecting structure 244 that extends fully or partially into the base between the spaced apart opposite inner end walls 243 , 244 . In this embodiment, the interconnecting structure 244 fills the gap 176 that exists in the conventional connector tool 170 shown in FIG. 3B .
[0073] FIG. 5A is a perspective view of a power connector 270 by Tyco/Amp where the connector top surface is chamfered on four sides into beveled surfaces such as surfaces 274 , 276 . The side walls 277 , 278 have slots such as slot 280 . The base of slot 280 is a seating area 279 for the push shoulder. A skirt 288 is slanted at the base of the connector. The power connector 270 consists of five mating pin slots such as slots 272 , 273 . FIG. 5B is a top view of the power connector 270 showing the slots 280 and 285 where the connector tool ribs must slide down to avoid crushing the connector during seating of the connector on the substrate.
[0074] FIG. 13A is a front view of a power connector tool 290 . The tool includes a guiding skirt structure such as skirt 299 . FIG. 13B is a front view of the connector tool 290 which is a machined structure with opposite vertical parallel walls 342 , 344 and skirts 289 , 305 as retaining corners. FIG. 13C is the bottom view of the connector tool 290 showing a vertical parallel wall 344 with guiding skirt structure such as skirts 303 and 305 . These structures help to position the power connector 270 under the connector tool 290 .
[0075] FIG. 14A is a perspective view of the power connector tool 290 shown in FIGS. 13A-13C . FIG. 14B is an enlarged view of the guiding skirt structure. The power connector tool 290 includes a plurality of spaced and corner chamfered tool ribs such as tool ribs 296 , 326 . The tool ribs 296 , 326 can be any suitable length, but are illustrated as terminating at the level of the vertical parallel wall 344 . The tool ribs 296 , 326 protrude orthogonally from the inner surface of the vertical parallel wall 344 and slide into the corresponding connector slots of the power connector 270 . The corner chamfered end of the tool ribs 296 , 326 are surfaces such as push shoulders 320 , 324 for seating the connector onto the substrate or PCB. The guiding skirt structure may include discrete skirts such as skirts 293 , 299 , 303 , 305 and 307 that extend above the vertical parallel walls such as walls 342 , 344 and are spaced with a guiding rib separation. The guiding skirt structure has discrete internal beveled or chamfered surfaces such as 314 , 316 , and 318 that align the power connector 270 with the connector tool 290 before seating the power connector 270 shown in FIG. 5A onto the substrate with an evenly distributed force. The guiding skirt structure solves the problem of the connector tool crushing the connector due to slight misalignment that arises from tolerances build up by the equipment, the connector tool precision, connector and substrate placement.
[0076] In another embodiment not shown, the guiding skirt structure does not have to be discrete. The guiding skirt structure may include a skirt with an internal beveled or chamfered surface that extends continuous along the vertical parallel walls. The guiding skirt structure with internal beveled surface is applicable to other connector tools to reduce connector damage by connector positioning before seating the connector onto the substrate. | The present invention relates to connector tools for seating connectors on a substrate such as a printed circuit board. In various embodiments, the connector tools can be made by wire electrode discharge machining (WEDM) process. In the embodiments, the connector tool includes reinforced ribbed end walls, ribbed internal walls, interconnected walls and contours that reduce tool and connector damage. In other embodiments, the connector tools include guiding structures that align the connector tool to the connector before seating the connector so that the connector tool aligns to the connector pins and body to avoid damage to the connector and/or the substrate. In another embodiment, the connector tool has guiding skirts and surfaces to capture the connector in position then seat the connector. Thus, the invention reduces connector and substrate damage during manufacturing, reduces tool damage, and lowers product costs by boosting manufacturing yields. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation and claims the priority benefit of U.S. patent application Ser. No. 14/690,254, titled “Conduction a Diagnostic Session for Monitored Business Tracking,” filed Apr. 17, 2015, which is a continuation and claims the priority benefit of U.S. patent application Ser. No. 14/071,525, titled “Conduction a Diagnostic Session for Monitored Business Tracking,” filed Nov. 4, 2013, which is a continuation and claims the priority benefit of U.S. patent application Ser. No. 13/189,360, titled “Automatic Capture of Diagnostic Data Based on Transaction Behavior Learning,” filed Jul. 22, 2011, which is a continuation-in-part and claims the priority benefit of U.S. patent application Ser. No. 12/878,919, titled “Monitoring Distributed Web Application Transactions,” filed Sep. 9, 2010, which claims the priority benefit of U.S. provisional application 61/241,256, titled “Automated Monitoring of Business Transactions,” filed Sep. 10, 2009, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The World Wide Web has expanded to provide web services faster to consumers. Web services may be provided by a web application which uses one or more services to handle a transaction. The applications may be distributed over several machines, making the topology of the machines that provides the service more difficult to track and monitor.
[0003] Monitoring a web application helps to provide insight regarding bottle necks in communication, communication failures and other information regarding performance of the services the provide the web application. When a web application is distributed over several machines, tracking the performance of the web service can become impractical with large amounts of data collected from each machine.
[0004] When a distributed web application is not operating as expected, additional information regarding application performance can be used to evaluate the health of the application. Collecting the additional information can consume large amounts of resources and often requires significant time to determine how to collect the information.
[0005] There is a need in the art for web service monitoring which may accurately and efficiently monitor the performance of distributed applications which provide a web service.
SUMMARY OF THE CLAIMED INVENTION
[0006] The present technology monitors a distributed network application system and may detect an anomaly based the learned behavior of the system. The behavior may be learned for each of one or more machines which implement a distributed business transaction. The present system may automatically collect diagnostic data for one or more business transactions and/or requests based on learned behavior for the business transaction or request. The diagnostic data may include detailed data for the operation of the distributed web application and be processed to identify performance issues for a transaction. Detailed data for a distributed web application transaction may be collected by sampling one or more threads assigned to handle portions of the distributed business transaction. Data regarding the distributed transaction may then be reported from agents monitoring portions of the distributed transaction to one or more central controllers and assembled by one or more controllers into business transactions. Data associated with one or more anomalies may be reported via one or more user interfaces.
[0007] Collection of diagnostic data at a server may be initiated locally by an agent or remotely from a controller. An agent may initiate collection of diagnostic data based on a monitored individual request or a history of monitored requests associated with a business transaction. For example, an agent at an application or Java Virtual Machine (JVM) may trigger the collection of diagnostic runtime data for a particular request if the request is characterized as an outlier. The agent may also trigger a diagnostic session for a business transaction or other category of request if the performance of requests associated with the business transaction varies from a learned baseline performance for the business transaction. The agent may determine baselines for request performance and compare the runtime data to the baselines to identify the anomaly. A controller may receive aggregated runtime data reported by the agents, process the runtime data, and determine an anomaly based on the processed runtime data that doesn't satisfy one or more parameters, thresholds or baselines.
[0008] In an embodiment, a method for performing a diagnostic session for a request may begin with initiating collection of diagnostic data associated with a request. An application thread on each of two or more servers may be sampled. The application threads may be associated with the same business transaction and the business transaction may be associated with the request. The diagnostic data may be stored.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram of an exemplary system for monitoring a distributed application.
[0010] FIG. 2 is a block diagram of an exemplary application server.
[0011] FIG. 3A is a flow chart of an exemplary method for performing a diagnostic session for a distributed web application transaction.
[0012] FIG. 3B is a flow chart of an exemplary method for collecting diagnostic data.
[0013] FIG. 4 is a flow chart of a method for locally identifying an anomaly.
[0014] FIG. 5 is a flow chart of an exemplary method for collecting diagnostic data.
[0015] FIG. 6A is a flow chart of an exemplary method for sampling a thread.
[0016] FIG. 6B is an illustration of an exemplary thread call stack data over time.
[0017] FIG. 7 is a flow chart of an exemplary method for modifying an application call.
[0018] FIG. 8 is a flow chart of an exemplary method for processing a received request.
[0019] FIG. 9A is a flow chart of an exemplary method for controller operation.
[0020] FIG. 9B is a flow chart of an exemplary method for instructing agents by a controller.
[0021] FIG. 10 is an exemplary interface providing a transaction flow map.
[0022] FIG. 11A is an exemplary interface for providing a call graph.
[0023] FIG. 11B is an exemplary interface for providing more information for selected call within a call graph.
[0024] FIG. 12 is an exemplary interface for providing SQL call information.
[0025] FIG. 13 is a block diagram of an exemplary system for implementing a computing device.
DETAILED DESCRIPTION
[0026] The present technology monitors a network or web application provided by one or more distributed applications. The web application may be provided by one or more web services each implemented as a virtual machine or one or more applications implemented on a virtual machine. Agents may be installed on one or more servers at an application level, virtual machine level, or other level. An agent may monitor a corresponding application (or virtual machine) and application communications. Each agent may communicate with a controller and provide monitoring data to the controller. The controller may process the data to learn and evaluate the performance of the application or virtual machine, model the flow of the application, and determine information regarding the distributed web application performance. The monitoring technology determines how each distributed web application portion is operating, establishes a baseline for operation, and determines the architecture of the distributed system.
[0027] The present technology may monitor a distributed web application that performs one or more business transactions. A business transaction may be a set of tasks performed by one or more distributed web applications in the course of a service provide over a network. In an e-commerce service, a business transaction may be “add to cart” or “check-out” transactions performed by the distributed application.
[0028] The behavior of a system which implements a distributed web transaction may be learned for each of one or more machines which implement the distributed transaction. The behavior may be learned for a business transaction which includes multiple requests and a particular request. The present system may automatically collect diagnostic data for one or more business transactions and/or requests based on learned behavior of the business transaction or request. The diagnostic data may include detailed data for the operation of the distributed web application and be processed to identify performance issues for a transaction. Detailed data for a distributed web application transaction may be collected by sampling one or more threads assigned to handle portions of the distributed business transaction. Data regarding the distributed transaction may then be reported from agents monitoring portions of the distributed transaction to one or more central controllers and assembled by one or more controllers into business transactions. Data associated with one or more anomalies may be reported via one or more user interfaces.
[0029] The present technology may perform a diagnostic session for an anomaly detected in the performance of a portion of a distributed web application, such as a business transaction or category of request. During the diagnostic session, detailed data may be collected for the operation of the distributed web application. The data may be processed to identify performance issues for a transaction. Detailed data for a distributed web application transaction may be collected by sampling one or more threads assigned to handle portions of the distributed business transaction. Data regarding the distributed transaction may be reported from one or more agents at an application or Java Virtual Machine (JVM) to one or more controllers. The data may be received and assembled by the one or more controllers into business transactions.
[0030] The monitoring system may monitor distributed web applications across a variety of infrastructures. The system is easy to deploy and provides end-to-end business transaction visibility. The monitoring system may identify performance issues quickly and has a dynamical scaling capability across a monitored system. The present monitoring technology has a low footprint and may be used with cloud systems, virtual systems and physical infrastructures.
[0031] Agents may communicate with code within virtual machine or an application. The code may detect when an application entry point is called and when an application exit point is called. An application entry point may include a call received by the application. An application exit point may include a call made by the application to another application, virtual machine, server, or some other entity. The code within the application may insert information into an outgoing call or request (exit point) and detect information contained in a received call or request (entry point). By monitoring incoming and outgoing calls and requests, and by monitoring the performance of a local application that processes the incoming and outgoing request, the present technology may determine the performance and structure of complicated and distributed business transactions.
[0032] FIG. 1 is a block diagram of an exemplary system for monitoring a distributed web application. The system of FIG. 1 may be used to implement a distributed web application and detect anomalies in the performance of the distributed web application. System 100 of FIG. 1 includes client device 105 , mobile device 115 , network 120 , network server 125 , application servers 130 , 140 , 150 and 160 , asynchronous network machine 170 , data stores 180 and 185 , and controller 190 .
[0033] Client device 105 may include network browser 110 and be implemented as a computing device, such as for example a laptop, desktop, workstation, or some other computing device. Network browser 110 may be a client application for viewing content provided by an application server, such as application server 130 via network server 125 over network 120 . Mobile device 115 is connected to network 120 and may be implemented as a portable device suitable for receiving content over a network, such as for example a mobile phone, smart phone, or other portable device. Both client device 105 and mobile device 115 may include hardware and/or software configured to access a web service provided by network server 125 .
[0034] Network 120 may facilitate communication of data between different servers, devices and machines. The network may be implemented as a private network, public network, intranet, the Internet, or a combination of these networks.
[0035] Network server 125 is connected to network 120 and may receive and process requests received over network 120 . Network server 125 may be implemented as one or more servers implementing a network service. When network 120 is the Internet, network server 125 maybe implemented as a web server.
[0036] Application server 130 communicates with network server 125 , application servers 140 and 150 , controller 190 . Application server 130 may also communicate with other machines and devices (not illustrated in FIG. 1 ). Application server 130 may host an application or portions of a distributed application and include a virtual machine 132 , agent 134 , and other software modules. Application server 130 may be implemented as one server or multiple servers as illustrated in FIG. 1 .
[0037] Virtual machine 132 may be implemented by code running on one or more application servers. The code may implement computer programs, modules and data structures to implement a virtual machine mode for executing programs and applications. In some embodiments, more than one virtual machine 132 may execute on an application server 130 . A virtual machine may be implemented as a Java Virtual Machine (JVM). Virtual machine 132 may perform all or a portion of a business transaction performed by application servers comprising system 100 . A virtual machine may be considered one of several services that implement a web service.
[0038] Virtual machine 132 may be instrumented using byte code insertion, or byte code instrumentation, to modify the object code of the virtual machine. The instrumented object code may include code used to detect calls received by virtual machine 132 , calls sent by virtual machine 132 , and communicate with agent 134 during execution of an application on virtual machine 132 . Alternatively, other code may be byte code instrumented, such as code comprising an application which executes within virtual machine 132 or an application which may be executed on application server 130 and outside virtual machine 132 .
[0039] Agent 134 on application server 130 may be installed on application server 130 by instrumentation of object code, downloading the application to the server, or in some other manner. Agent 134 may be executed to monitor application server 130 , monitor virtual machine 132 , and communicate with byte instrumented code on application server 130 , virtual machine 132 or another application on application server 130 . Agent 134 may detect operations such as receiving calls and sending requests by application server 130 and virtual machine 132 . Agent 134 may receive data from instrumented code of the virtual machine 132 , process the data and transmit the data to controller 190 . Agent 134 may perform other operations related to monitoring virtual machine 132 and application server 130 as discussed herein. For example, agent 134 may identify other applications, share business transaction data, aggregate detected runtime data, and other operations.
[0040] Each of application servers 140 , 150 and 160 may include an application and an agent. Each application may run on the corresponding application server or a virtual machine. Each of virtual machines 142 , 152 and 162 on application servers 140 - 160 may operate similarly to virtual machine 132 and host one or more applications which perform at lease a portion of a distributed business transaction. Agents 144 , 154 and 164 may monitor the virtual machines 142 - 162 , collect and process data at runtime of the virtual machines, and communicate with controller 190 . The virtual machines 132 , 142 , 152 and 162 may communicate with each other as part of performing a distributed transaction. In particular each virtual machine may call any application or method of another virtual machine.
[0041] Controller 190 may control and manage monitoring of business transactions distributed over application servers 130 - 160 . Controller 190 may receive runtime data from each of agents 134 - 164 , associate portions of business transaction data, communicate with agents to configure collection of runtime data, and provide performance data and reporting through an interface. The interface may be viewed as a web-based interface viewable by mobile device 115 , client device 105 , or some other device. In some embodiments, a client device 192 may directly communicate with controller 190 to view an interface for monitoring data.
[0042] Asynchronous network machine 170 may engage in asynchronous communications with one or more application servers, such as application server 150 and 160 . For example, application server 150 may transmit several calls or messages to an asynchronous network machine. Rather than communicate back to application server 150 , the asynchronous network machine may process the messages and eventually provide a response, such as a processed message, to application server 160 . Because there is no return message from the asynchronous network machine to application server 150 , the communications between them are asynchronous.
[0043] Data stores 180 and 185 may each be accessed by application servers such as application server 150 . Data store 185 may also be accessed by application server 150 . Each of data stores 180 and 185 may store data, process data, and return queries received from an application server. Each of data stores 180 and 185 may or may not include an agent.
[0044] FIG. 2 is a block diagram of an exemplary application server 200 . The application server in FIG. 2 provides more information for each application server of system 100 in FIG. 1 . Application server 200 of FIG. 2 includes a virtual machine 210 , application 220 executing on the virtual machine, and agent 230 . Virtual machine 210 may be implemented by programs and/or hardware. For example, virtual machine 134 may be implemented as a JAVA virtual machine. Application 220 may execute on virtual machine 210 and may implement at least a portion of a distributed application performed by application servers 130 - 160 . Application server 200 , virtual machine 210 and agent 230 may be used to implement any application server, virtual machine and agent of a system such as that illustrated in FIG. 1 .
[0045] Application server 200 and application 220 can be instrumented via byte code instrumentation at exit and entry points. An entry point may be a method or module that accepts a call to application 220 , virtual machine 210 , or application server 200 . An exit point is a module or program that makes a call to another application or application server. As illustrated in FIG. 2 , an application server 200 can have byte code instrumented entry points 240 and byte code instrumented exit points 260 . Similarly, an application 220 can have byte code instrumentation entry points 250 and byte code instrumentation exit points 270 . For example, the exit points may include calls to JDBC, JMS, HTTP, SOAP, and RMI. Instrumented entry points may receive calls associated with these protocols as well.
[0046] Agent 230 may be one or more programs that receive information from an entry point or exit point. Agent 230 may process the received information, may retrieve, modify and remove information associated with a thread, may access, retrieve and modify information for a sent or received call, and may communicate with a controller 190 . Agent 230 may be implemented outside virtual machine 210 , within virtual machine 210 , and within application 220 , or a combination of these.
[0047] FIG. 3A is a flow chart of an exemplary method for performing a diagnostic session for a distributed web application transaction. The method of FIG. 3 may be performed for a web transaction that is performed over a distributed system, such as the system of FIG. 1 .
[0048] Diagnostic parameters may be configured for one or more agents at step 310 . The diagnostic parameters may be used to implement a diagnostic session conducted for a distributed web application business transaction. The parameters may be set by a user, an administrator, may be pre-set, or may be permanently configured.
[0049] Examples of diagnostic parameters that may be configured include the number of transactions to simultaneously track using diagnostic sessions, the number of transactions tracked per time period (e.g., transactions tracked per minute), the time of a diagnostic session, a sampling rate for a thread, a threshold percent of requests detected to run slow before triggering an anomaly, outlier information, and other data. The number of transactions to simultaneously track using diagnostic sessions may indicate the number of diagnostic sessions that may be ongoing at any one time. For example, a parameter may indicate that only 10 different diagnostic sessions can be performed at any one time. The time of a diagnostic session may indicate the time for which a diagnostic session will collect detailed data for operation of a transaction, such as for example, five minutes. The sampling rate of a thread may be automatically set to a sampling rate to collect data from a thread call stack based on a detected change in value of the thread, may be manually configured, or otherwise set. The threshold percent of requests detected to run slow before triggering an anomaly may indicate a number of requests to be detected that run at less than a baseline threshold before triggering a diagnostic session. Diagnostic parameters may be set at either a controller level or an individual agent level, and may affect diagnostic tracking operation at both a controller and/or an agent.
[0050] Requests may be monitored and runtime data may be collected at step 320 . As requests are received by an application and/or JVM, the requests are associated with a business transaction by an agent residing on the application or JVM, and may be assigned a thread within a thread pool by the application or JVM itself. The business transaction is associated with the thread by adding business transaction information, such as a business transaction identifier, to the thread by an agent associated with the application or JVM that receives the request. The thread may be configured with additional monitoring parameter information associated with a business transaction. Monitoring information may be passed on to subsequent called applications and JVMs that perform portions of the distributed transaction as the request is monitored by the present technology.
[0051] Diagnostic data is collected by an agent at step 330 . Diagnostic data may be collected for one or more transactions or requests. Diagnostic data may be collected based on the occurrence of an outlier or an anomaly. Collecting diagnostic data is discussed in more detail below with respect to FIG. 3B .
[0052] A determination is made as to whether instructions have been received from a controller to collect diagnostic data at step 340 . A diagnostic session may be triggered “centrally” by a controller based on runtime data received by the controller from one or more agents located throughout a distributed system being monitored. If a controller determines that an anomaly is associated with a business transaction, or portion of a business transaction for which data has been reported to the controller, the controller may trigger a diagnostic session and instruct one or more agents residing on applications or JVMs that handle the business transaction to conduct a diagnostic session for the distributed business transaction. Operation of a controller is discussed in more detail below with respect to the method of FIG. 9A .
[0053] If no instructions are received from a controller to collect diagnostic data, the method of FIG. 3 continues to step 360 . If instructions are received from a controller to collect diagnostic data, diagnostic data is collected based on the controller instructions at step 350 . An agent receiving the instructions may collect data for the remainder of the current instance of a distributed application as well as subsequent instances of the request. Collecting diagnostic data based on instructions received by a controller is described below with respect to the method of FIG. 5 . Next, data collected by a particular agent is reported to a controller at step 360 . Each agent in a distributed system may aggregate collected data and send data to a controller. The data may include business transaction name information, call chain information, the sequence of a distributed transaction, and other data, including diagnostic data collected as part of a diagnostic session involving one or more agents.
[0054] FIG. 3B is a flow chart of an exemplary method for collecting diagnostic data. The method of FIG. 3B provides more detail for step 330 of the method of FIG. 3A . A determination is made as to whether an individual request is locally identified as an outlier by an agent at step 370 . The identification may be determined based on runtime data collected for the particular request. An outlier may be identified as a request having a characteristic that satisfies a certain threshold. For example, an outlier may have a response time, or time of completion, that is greater than a threshold used to identify outliers. The threshold may be determined based on an average and a standard deviation for the request characteristic. For example, the average time for a request to complete may be 200 milliseconds, and the standard deviation may be 20 milliseconds. A request having a duration within the standard deviation of the average may be considered normal, a request outside the standard deviation but within a range of twice the standard deviation may be considered slow, and a request having a duration outside twice the standard deviation from the average may be considered an outlier.
[0055] If the request is locally identified locally as an outlier at step 370 , a diagnostic data (i.e., detailed data regarding the request) associated with the particular request associated with the outlier is collected at step 375 . Diagnostic data may be collected by sampling a thread call stack for the thread that is locally handling the request associated with the outlier. The agent may collect data for the remainder of the request duration. After collecting diagnostic data, the method of FIG. 3B continues to step 380 . If the request is not identified locally as an anomaly, the method of FIG. 3 continues at step 380 .
[0056] A determination is made as to whether a business transaction is locally identified as an anomaly at step 380 . A business transaction may be locally identified as an anomaly by an agent that resides on an application or JVM and processes runtime data associated with the business transaction. The agent may identify the anomaly based on aggregated abnormal behavior for the business transaction, such as an increase in the rate of outliers for the business transaction. For example, if the business transaction has a higher rate of outliers in the last ten minutes than a learned baseline of outliers for the previous hour for the business transaction, the agent may identify the corresponding business transaction performance as an anomaly and trigger a diagnostic session to monitor the business transaction. Identifying a business transaction as an anomaly is discussed in more detail below with respect to the method of FIG. 4 .
[0057] If the business transaction is identified locally as an anomaly at step 380 , a diagnostic session is triggered and diagnostic data associated with the anomalous business transaction is collected at step 385 . Diagnostic data may be collected by sampling a thread call stack for the thread that is locally handling one or more requests that form the business transaction that triggered the diagnostic session. The agent may collect data for future occurrences of the business transaction. Outgoing calls associated with the monitored transaction may be monitored to initiate called applications to perform collect diagnostic data as part of the diagnostic session for the transaction. Collecting diagnostic data associated with an anomaly is discussed in more detail below with respect to FIG. 5 . After collecting diagnostic data, the method of FIG. 3B ends. If the request is not identified locally as an anomaly, the method of FIG. 3B ends.
[0058] FIG. 4 is a flow chart of an exemplary method for locally identifying an anomaly for a business transaction. The method of FIG. 4 may be performed by an agent, such as agent 134 , 144 , 164 or 154 , and may provide more detail for step 380 of the method of FIG. 3B . Locally identifying an anomaly may begin with determining a business transaction performance baseline from collected runtime data at step 410 . The runtime data may include the time for an application or JVM to complete a business transaction. The performance baseline may be for a rate of outliers which occur for the business transaction for a period of time. The performance baseline may be determined for the particular machine, or virtual machine (such as a Java Virtual Machine) on which the agent is monitoring data.
[0059] A performance baseline may be determined automatically and continuously by an agent. The moving average may be associated with a particular window, such as one minute, ten minutes, or an hour, the time of day, day of the week, or other information to provide a context which more accurately describes the typical performance of the system being monitored. For example, baselines may be determined and updated for transactions occurring within a specific time range within a day, such as 11:00 AM to 2:00 PM. The baseline may be, for example, a moving average of the time to perform a request, the number of outliers occurring, or other data collected during the particular baseline window. For purposes of discussion, a baseline is discussed with respect to a rate of outliers occurring for a business transaction within a time window at a particular machine.
[0060] In some embodiments, a standard deviation may be automatically determined by the agent, controller, or other source and used to identify an anomaly. For example, a baseline may be determined from an average response time of one second for a particular transaction. The standard deviation may be 0.3 seconds. As such, a response time of 1.0-1.3 seconds may be an acceptable time for the business transaction to occur. A response time of 1.3-1.6 seconds may be categorized as “slow” for the particular request, and a response time of 1.6-1.9 seconds may be categorized as very slow and may be identified as an anomaly for the request. An anomaly may also be based on a number requests having a response time within a particular derivative range. For example, an anomaly may be triggered if 15% or more of requests have performed “slow”, or if three or more instances of a request have performed “very slow.”
[0061] The runtime data collected for current outliers is compared to the business transaction performance baseline at step 420 by the particular agent. For example, the number of outliers occurring for a business transaction in the time window is compared to the baseline of outlier occurrence for the business transaction.
[0062] An anomaly may be identified by the agent based on the comparison at step 430 . For example, if an agent detects that the number of outliers that occurred for a business transaction within a the past ten minutes is greater than the baseline outlier rate for the business transaction, the agent may identify an anomaly.
[0063] FIG. 5 is a flow chart of an exemplary method for collecting diagnostic data. The method of FIG. 5 may provide more detail for step 350 of the method of FIG. 3A . A request global unique identifier (GUID) may be created and associated with the request at step 510 . The request GUID may be generated locally by an agent or remotely by a controller. When generated by a controller, the agent may create a temporary identifier for the anomaly, report the temporary identifier to the controller, and then receive the diagnostic session GUID to use subsequently to identify the anomaly.
[0064] A thread call stack may be sampled, stored and processed at step 520 . The thread assigned to handle a request may be sampled to determine what the thread is presently handling for the request. The thread call stack data received from the sampling may be stored for later processing for the particular distributed web transaction. Sampling and storing a thread call stack is discussed in more detail below with respect to the method at FIG. 6A .
[0065] An outgoing application call may be modified with diagnostic tracking information at step 530 . When a call to an outside application is detected, the call may be modified with diagnostic information for the receiving application. The diagnostic information may include the diagnostic session GUID and other data. Modifying an outgoing application call with diagnostic tracking information is discussed in more detail with respect to the method at FIG. 7 .
[0066] A completed request is detected at step 540 . At the completion of the request, data for the request associated with the anomaly may be stored by the agent and eventually sent to a controller. The diagnostic session may be continued for a period of time specified in a corresponding diagnostic parameter for the agent.
[0067] FIG. 6A is a flow chart of an exemplary method for sampling a thread. The method of FIG. 6A may provide more detail for step 520 of the method of FIG. 5 . Thread identification information may be accessed at step 605 . The thread identification information may be accessed from a JVM or application server that manages the thread pool from which a thread was selected to handle a request associated with the anomaly.
[0068] An initial sampling rate for the thread may be set at step 610 . The initial sampling rate may be set to a default rate, for example a rate of every 10 milliseconds.
[0069] The current thread call stack is accessed at the set thread sampling rate at step 615 . Sampling the thread call stack may detect what the thread is currently doing. For example, sampling the thread call stack may reveal that the thread is currently processing a request, processing a call to another application, executing an EJB, or performing some other process. The thread call stack may be sampled and the sampled data may be stored locally by the agent sampling the stack.
[0070] After sampling of the thread call stack, the agent may determine whether the thread call stack data retrieved as a result of the sampling has changed at step 620 . The change is determined by the agent by comparing the most recent call stack data to the previous call stack data. A thread snapshot is updated at step 640 based on the most recent sampling. The snapshot indicates what the thread call stack has performed. An example of a call stack is discussed below with respect to the interface of FIG. 11 . The update may be based on calls, requests, or timelines identified from the sampling.
[0071] A thread snapshot is updated at step 625 . The thread snapshot is updated to indicate changes to the thread call stack. A determination is made at step 630 to determine if an event has been detected at step 630 . The event may be the expiration of a period of time (for example, based on thread sampling rate), the detection of a new request made by a thread, or some other event. If an event is detected, the thread call stack is sampled at step 635 and the method of FIG. 6A continues to step 640 . If no event is detected, the method of FIG. 6A continues to step 640 .
[0072] A determination is made at step 640 as to whether the thread has completed at step 640 . If the thread is complete, the method of FIG. 6A ends. If the thread is not complete, a determination is made as to whether the thread sampling rate should be adjusted. In some embodiments, the sampling rate may be adjusted after a period of time, for example every two minutes. If the sampling rate is determined not to be adjusted at step 645 , the method of FIG. 6A continues to step 615 . If the sampling rate is adjusted, the new sampling rate is set at step 650 and the method continues to step 615 . The sampling rate may be adjusted to save processing cycles and resources after a set period of time.
[0073] FIG. 6B is an illustration of an exemplary thread call stack data representation over time. The method of FIG. 6B indicates exemplary states of a thread call stack sampled at different times. Each state includes a snapshot of data in the call stack at the corresponding sampling times. For example, for a sampling at time of 0 milliseconds (ms), the call stack indicates that an initial request A is being executed. At a time of 10 ms, the thread call stack indicates that the thread is executing a request to an application B. As such, it can be inferred that request A has made a call to application B. At a time of 20 ms, the thread call stack indicates that application B has called application C. At a time of 30 ms, there is no change in the stack.
[0074] At a time of 34 ms, a call to D may be detected. As a result, the thread call stack may be sampled as a result of detecting the call at a time of 34 ms. Hence, a thread call stack may be sampled in response to detecting a call in addition to periodically.
[0075] At a time of 40 ms in FIG. 6B , the thread call stack indicates that application C is no longer present at the top of the stack. Rather, application D has been called by application B. The agent sampling the call stack may determine from this series of thread call stack data that application C executed for 20 ms and that application B called application D after calling application C. At a time of 50 ms, there is no change in the call stack.
[0076] At a time of 60 ms, application D has completed and application B has again called application C. An agent processing the thread call stack data may determine that application D executed for 20 ms, and application B called C a second time. The second call to application C may be represent a sequence of calls to application C (one at 20 ms sampling, and one at 60 ms sampling). The present technology may differentiate between each call to application C as part of the request. At 70 ms in time, application C has completed, corresponding to an execution of 10 milliseconds for the second call to application C. At a time of 80 ms, B has completed, corresponding to an execution time of 70 milliseconds for application B.
[0077] FIG. 7 is a flow chart of an exemplary method for modifying an application call. The method of FIG. 7 may provide more detail for step 530 of the method of FIG. 5 and may be performed by an agent located at an application or JVM that is calling the application.
[0078] First, an application call is detected at step 710 . The application call may be detected by sampling a thread call stack associated with the thread handling a request being monitored.
[0079] The application call recipient may be added to a call chain at step 720 . Once the call is detected at step 710 , information regarding the call can be accessed from the thread call stack, including the recipient of the detected call. The call recipient may be added to a call chain maintained in the thread being monitored. The call chain may include call sequence information if more than one call is made to a particular application as part of processing a request locally.
[0080] The call chain attribute and call sequence attribute may be added to the call header at step 730 . A diagnostic session GUID may be added to the call header at step 740 . An application receives the call with a diagnostic session GUID, and an agent at the receiving application detects the diagnostic session GUID. The agent on the receiving application may then monitor the thread processing the received call, associated collected data with the particular diagnostic session GUID, and report the data to a controller. The application call may then be sent with the modified call header to an application at step 750 .
[0081] FIG. 8 is a flow chart of an exemplary method for processing a received request. The method of FIG. 8 may be performed by an application which receives a request sent with a modified call header from an application collecting data as part of a diagnostics session. For example, the method of FIG. 8 describes how an application processes the received call that is originated by the application call of step 750 .
[0082] A request is received by the application at step 810 . An agent may detect a request GUID in the request header at step 820 . The request GUID may indicate an identifier for a diagnostic session currently underway for a distributed transaction that includes the particular request. The received request may be performed and monitored at step 830 . Runtime data, including diagnostic data, may be collected throughout processing of the request at step 840 . The request's completion is detected at step 850 , and a response to the received request is generated and transmitted to the requesting application at step 860 . Eventually, collected runtime data including diagnostic data and other data associated with the request may be reported to a controller at step 870 .
[0083] FIG. 9A is a flow chart of an exemplary method for controller operation. The method of FIG. 9 may be performed by control 190 . Aggregated runtime data may be received from one or more agents by a controller at step 910 . The aggregated runtime data may include diagnostic data generated in response to triggering one or more diagnostic sessions.
[0084] A call chain may be constructed for each business transaction at step 920 . The call chain is constructed from the aggregated runtime data. For example, transactions may be pieced together based on request GUIDs and other data to build a call chain for each business transaction. Received diagnostic data for locally identified anomalies may be processed by the controller at step 930 . Processing the diagnostic data may include determining the response times for portions of a distributed business transaction as well as the transaction as a whole, identifying locally detected anomalies, and other processing. Baseline performance for a business transaction call chain is determined at step 940 . The baseline performance may be determined based on past performance for each business transaction and portions thereof, including for example each request that is made as part of a business transaction.
[0085] Selected agents associated with the applications and JVMs that perform the transaction associated with the anomaly are instructed to collect diagnostic data based on diagnostic parameters at step 950 . The diagnostic data may be collected as part of a diagnostic session already triggered by an agent (locally determined anomaly) or triggered by the controller. In some embodiments, the controller may determine whether the maximum number of diagnostic sessions is already reached, and if so may place the presently detected diagnostic session in a queue for execution as soon as a diagnostic session is available.
[0086] Diagnostic data is received from selected agents collecting data as part of the diagnostic session at step 960 . Performance data is generated from the collected diagnostic data received from one or more agents, and the performance data may be reported by the controller at step 970 . The performance data may be reported via one or more interfaces, for example through an interface discussed in more detail with respect to FIGS. 10-12 .
[0087] FIG. 9B is a flow chart of an exemplary method for instructing agents by a controller. A determination is made as to whether any anomalies are identified by the controller based on baseline performance or received locally identified anomalies at step 975 . If no anomaly is detected, the method continues to step 985 . If an anomaly is detected, selected agents associated with the anomaly are instructed to collect diagnostic data based on diagnostic parameters at step 980 . The method then continues to step 985 .
[0088] A determination is made as to whether selected agents are identified to perform a diagnostic session per performance sampling at step 985 . If no agents are identified, the method ends. If one or more agents are selected, the selected agents are instructed to collect diagnostic data based on the diagnostic parameters.
[0089] During a diagnostic session, deep diagnostic data may be retrieved for one or more distributed business transactions associated with a diagnostic session which are performed by one or more applications or JVMs. FIGS. 10-12 illustrate exemplary interfaces for displaying information associated with a diagnostic session.
[0090] FIG. 10 is an exemplary interface providing a transaction flow map. Interface 1000 in FIG. 10 includes a transaction flow map frame 1010 , a load information frame 1020 , average response time frame 1030 , incident description frame 1040 , and request summary frame. Transaction flow map frame 1010 provides a map of the applications or JVMs that comprise the distributed web transaction associated with a diagnostic session triggered by an anomaly. The upper portion of frame 1010 indicates the status of the anomaly request, the duration, the name of the business transaction, a triggering policy, a start time, an end time, and may include other additional data. The status of the request is “open,” the duration is ongoing and has been ongoing for 10 minutes, the business transaction associated with the anomaly is a “checkout” transaction.
[0091] The transaction flow map 1010 includes an e-commerce service application, an inventory service application, an inbound inventory database, another inventory database, an order processing service application, and an orders database. The time spent at each application or database by the request is indicated in the flow map, as well as a percentage of the overall time the request spent at that application. Other information such as the type of request received between two applications is also shown to illustrate the relationships between the applications which perform the distributed application.
[0092] Load information frame 1020 indicates the load result for the particular request in a format of calls received per minute. The average response time frame indicates the average response time for the request over time. The incident description frame 1020 indicates a description of the incident associated with the anomaly. The request summary indicates the number of requests which fall into different categories, such as normal, slow, very slow, errors, and stalls. Other information, including recent request snapshots with call graphs and recent errors, may also be illustrated within a transaction flow map interface 1000 .
[0093] FIG. 11A is an exemplary interface for providing a call graph. Interface 1100 includes a selection menu 1110 on the left side of the interface in which a call graph is selected. The main window 1120 of interface 1100 illustrates the call graph and in particular a hierarchical representation of calls made while executing the current request. An indication 1130 of an incident is indicated within the call graph. For each step in the call graph, the name of the application called, the time at which the application executed, external calls made by the application, and other details are illustrated in the call graph.
[0094] FIG. 11B is an exemplary interface for providing more information for selected call within a call graph. In FIG. 11B , a window appears in the in the lower right portion of the interface. The window provides more information for a selected portion of a call stack. The selected portion is a method titled “OrderServiceSDAP11Binding Stub:createOrder.” The information provided in the window includes the web service name “Order Service”, the operation name “createOrder”, and the time, 10008 ms, taken to complete the call.
[0095] FIG. 12 is an exemplary interface for providing SQL call information. Interface 1200 of FIG. 12 indicates that SQL calls are indicated in a selection menu within the interface. The SQL call information is illustrated in a list of calls. An incident 1220 may be highlighted which indicates an incident associated with a particular SQL call. For each SQL call, information is illustrated such as the query type, the query, a count, the time of execution, the percentage time of the total transaction, the tier the call is received from, the tier the call is made to, and other data.
[0096] FIG. 13 illustrates an exemplary computing system 1300 that may be used to implement a computing device for use with the present technology. System 1300 of FIG. 13 may be implemented in the contexts of the likes of data store 130 , application server 120 , network server 130 , database 122 , and clients 150 - 160 . The computing system 1300 of FIG. 13 includes one or more processors 1310 and memory 1310 . Main memory 1310 stores, in part, instructions and data for execution by processor 1310 . Main memory 1310 can store the executable code when in operation. The system 1300 of FIG. 13 further includes a mass storage device 1330 , portable storage medium drive(s) 1340 , output devices 1350 , user input devices 1360 , a graphics display 1370 , and peripheral devices 1380 .
[0097] The components shown in FIG. 13 are depicted as being connected via a single bus 1390 . However, the components may be connected through one or more data transport means. For example, processor unit 1310 and main memory 1310 may be connected via a local microprocessor bus, and the mass storage device 1330 , peripheral device(s) 1380 , portable storage device 1340 , and display system 1370 may be connected via one or more input/output (I/O) buses.
[0098] Mass storage device 1330 , which may be implemented with a magnetic disk drive or an optical disk drive, is a non-volatile storage device for storing data and instructions for use by processor unit 1310 . Mass storage device 1330 can store the system software for implementing embodiments of the present invention for purposes of loading that software into main memory 1310 .
[0099] Portable storage device 1340 operates in conjunction with a portable non-volatile storage medium, such as a floppy disk, compact disk or Digital video disc, to input and output data and code to and from the computer system 1300 of FIG. 13 . The system software for implementing embodiments of the present invention may be stored on such a portable medium and input to the computer system 1300 via the portable storage device 1340 .
[0100] Input devices 1360 provide a portion of a user interface. Input devices 1360 may include an alpha-numeric keypad, such as a keyboard, for inputting alpha-numeric and other information, or a pointing device, such as a mouse, a trackball, stylus, or cursor direction keys. Additionally, the system 1300 as shown in FIG. 13 includes output devices 1350 . Examples of suitable output devices include speakers, printers, network interfaces, and monitors.
[0101] Display system 1370 may include a liquid crystal display (LCD) or other suitable display device. Display system 1370 receives textual and graphical information, and processes the information for output to the display device.
[0102] Peripherals 1380 may include any type of computer support device to add additional functionality to the computer system. For example, peripheral device(s) 1380 may include a modem or a router.
[0103] The components contained in the computer system 1300 of FIG. 13 are those typically found in computer systems that may be suitable for use with embodiments of the present invention and are intended to represent a broad category of such computer components that are well known in the art. Thus, the computer system 1300 of FIG. 13 can be a personal computer, hand held computing device, telephone, mobile computing device, workstation, server, minicomputer, mainframe computer, or any other computing device. The computer can also include different bus configurations, networked platforms, multi-processor platforms, etc. Various operating systems can be used including Unix, Linux, Windows, Macintosh OS, Palm OS, and other suitable operating systems.
[0104] The foregoing detailed description of the technology herein has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the technology to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the technology and its practical application to thereby enable others skilled in the art to best utilize the technology in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the technology be defined by the claims appended hereto. | The present technology may determine an anomaly in a portion of a distributed business application. Data can automatically be captured and analyzed for the portion of the application associated with the anomaly. By automatically capturing data for just the portion associated with the anomaly, the present technology reduces the resource and time requirements associated with other code-based solutions for monitoring transactions. A method for performing a diagnostic session for a request may begin with initiating collection of diagnostic data associated with a request. An application thread on each of two or more servers may be sampled. The application threads may be associated with the same business transaction and the business transaction may be associated with the request. The diagnostic data may be stored. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a U.S. National Stage entry under 35 U.S.C. §371 based on International Application No. PCT/JP2010/054056, filed Mar. 10, 2010, published under PCT Article 21(2) on Sep. 16, 2010 as WO2010/104135, which claim priority to Japanese Patent Application No. 2009-059790, filed Mar. 12, 2009.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a simulation of a physical system such as an automobile. In particular the present invention relates to a simulation system, method, and article of manufacture in which a continuous simulator and discrete-event simulators are improved by loosely synchronizing the simulators thereby reducing the frequency and cost of inter-thread or inter-processor communication.
2. Description of Related Art
Automobiles in the early years of the 20th century were made up of mechanical parts, including an engine, which is a power source to move the automobile, a brake, an accelerator, a steering wheel, a transmission, and a suspension, and used few electrical mechanisms; exceptions include spark ignition of the engine and a headlight.
Electronic control units (ECUs) have come into use for controlling engines in about the 1970s because of the need for efficiently controlling engines in order to reduce air pollution and in preparation for oil crunch. An ECU typically includes an input interface which converts an analog input signal coming from a sensor to a digital signal, a logic unit (microcomputer) which processes the digital input signal according to a predetermined logic, and an output interface which converts the processed signal to an actuator activation signal.
In addition to mechanical components, electronic components and software form a significant proportion of engine and transmission control systems, Anti-lock Braking Systems (ABSs), Electronic Stability Controls (ESCs), and power steering as well as wiper control and security monitoring systems of today's automobiles. Development costs relating to the electronic components and software are said to be 25 or 40% of the total development cost and make up 70% of the development cost for hybrid electric vehicles.
Electronic control is accomplished by providing multiple ECUs. The ECUs are interconnected through an in-vehicle network, for example a Controller Area Network (CAN). The components such as the engine and transmission which are to be controlled are directly connected to their respective ECUs through wires.
An ECU is a small computer that operates in response to an interrupt from a sensor input and the like. The engine and other components, on the other hand, are continuously mechanically operating. That is, digital systems, which are computer systems, and physical systems, which are mechanical systems, are cooperating simultaneously in the single system of the automobile. Naturally, the complexity of software that supports the cooperation is increasing. Therefore, there is demand for implementation of a mechanism that not only separately tests operation of each ECU but also tests multiple ECUs simultaneously.
On the other hand, actuators such as electromagnetic solenoids and motors are driven by signals output from the ECUs. Solenoids are used in an engine injector, the shift control of the transmission, brake valve controls, and door locks.
A conventional technique used for such tests is Hardware In the Loop Simulation (HILS). An environment in which the ECUs of a whole automobile are tested in particular is called Whole Vehicle HILS (Whole Vehicle Hardware In the Loop Simulation). In the whole vehicle HILS, real ECUs are connected to a dedicated hardware device that emulates components, such as an engine and a transmission mechanism in a laboratory, and tests are conducted according to predetermined scenarios. Outputs from the ECUs are input into a monitoring computer and are displayed on a display. A person responsible for the testing checks the outputs displayed on the display for an abnormal operation.
However, HILS involves burdensome preparations because it uses the dedicated hardware device, which needs to be physically connected to each real ECU. Furthermore, when an ECU is replaced with another one for testing, again the ECU needs to be physically connected to the dedicated hardware device, which is time-consuming. Moreover, testing requires actual time since real ECUs are used. Accordingly, testing many scenarios takes huge amounts of time. In addition, the hardware devices for HILS emulations in general are very expensive.
Therefore, more recently a method in which simulations are configured by software without using expensive emulation hardware devices has been made available. In the method, called Software In the Loop Simulation (SILS), all elements such as microcomputers and input/output circuits contained in ECUs as well as control scenarios are all formed by software simulators. This enables test to be conducted without the hardware of the ECUs.
A simulation system for automobile includes continuous simulators and discrete-event simulators. An example of the continuous simulator is a simulator that simulates a mechanical section of an engine. An example of discrete-event simulator is a simulator for an ECU that operates with the timing of a pulse of engine rotation to control the timings of fuel injection and ignition.
An example of continuous simulator that simulates a 4WD is a simulator that repeatedly calculates operation of the vehicle from torque apportioned to each wheel. An example of discrete-event simulator for 4WD is a simulator that operates with pulsed signals at regular intervals of 10 milliseconds, and that simulates an ECU that determines torque to be apportioned to each wheel from a sensor input such as the yaw rate of the vehicle.
In addition to receiving the pulse signal, the discrete-event simulator reads and writes data through an I/O port asynchronously to a time slice of the continuous simulator. Typically, the discrete-event simulator reads and updates data from a sensor.
FIG. 1 illustrates a block diagram of a configuration of a typical conventional discrete-event/continuous simulation system. The discrete-event simulator of the system includes ECU emulators 102 , 104 and 106 . While the system in practice includes more ECU emulators, only three ECU emulators are depicted for illustrative purposes.
Since the ECU emulators 102 , 104 and 106 are substantially identical in function to one another, only the ECU emulator 102 will be described as a representative example. The ECU emulator 102 includes a CPU emulator 102 a and a peripheral emulator 102 b . The CPU emulator 102 a is a module that emulates a logical function of a real ECU.
The peripheral emulator 102 b receives a continuous pulse signal from a plant simulator 108 , which is a continuous simulator such as an engine simulator, converts the continuous pulse signal to an interrupt event signal, passes the interrupt event signal to the discrete CPU emulator 102 a , or converts an interrupt event signal received from the CPU emulator 102 a to a continuous pulse signal.
Enclosed in the dashed rectangular blocks in FIG. 1 are individual threads of a simulation program. The individual threads are preferably allocated to individual cores or processors in a multi-core or multiprocessor environment.
FIG. 2 illustrates a timing chart of communications between the ECU emulators 102 , 104 and 106 and the plant simulator 108 . As can be seen from FIG. 2 , the ECU emulator, which is a discrete system, and the plant simulator, which is a continuous system, in the configuration in FIG. 1 are in synchronization with each other at clock intervals.
However, inter-thread communication occurs at every clock pulse because the plant simulator 108 and the ECU emulators 102 , 104 and 106 are executed in different threads as can be seen from the dashed blocks in FIG. 1 . If the individual threads are assigned to separate cores or processors for parallel execution, inter-processor communication occurs. The inter-thread communication or the inter-processor communication that occurs once every clock interval involves enormous cost, which inhibits improvement of the speed of operation of the simulation system.
Japanese Published Unexamined Patent Application No. 2001-290860 aims to provide a hardware/software cooperative simulator to improve the speed of simulation by finding an unnecessary synchronization process between simulators and reducing the synchronization process, and discloses a simulator including simulation coordinating means for synchronizing CPU simulation means and peripheral circuit simulation means and determination means for determining whether or not to suppress synchronization in the simulation coordinating means, wherein the synchronization in the simulation coordinating means is suppressed according to the determination means.
Japanese Published Unexamined Patent Application No. 8-227367 aims to provide a debugger that uses a fast simulator that ignores all system operations excluding system operations in which design errors are expected to appear to increase the speed of debugging, and discloses a debugger including a bus simulator of a bus providing a signal corresponding to a bus cycle for interconnecting simulators and means for omitting a bus cycle unnecessary for simulation, wherein a CPU bus cycle irrelevant to simulation is omitted or a periodic clock signal is explicitly avoided from being simulated so that only a schedule of the clock signal is generated.
Japanese Published Unexamined Patent Application No. 2004-30228 discloses a simulator including a CPU simulator, one or more peripheral macro-simulators, and synchronous execution control processing unit controlling synchronous execution of these, wherein the peripheral macro-simulator(s) execute simulation based on a terminal signal when the terminal signal, which is input to a terminal on the basis of simulation in the CPU simulator, has changed. The peripheral macro-simulator(s) detect a change in the input terminal signal, registers the changed terminal signal on a terminal signal list 22, and performs simulation only for the registered terminal signal.
Japanese Published Unexamined Patent Application No. 2006-65758 discloses a circuit simulation method, wherein a response function is provided to a first discrete time model generated from circuit data to generate a second discrete time model, an edge timing of a clock and an effective signal value of a signal input into and output from a clock synchronization circuit at the timing are calculated using the second discrete model, and simulation is performed using these.
SUMMARY OF THE INVENTION
The existing techniques described above conditionally synchronizes simulators or find an edge timing of a clock in order to reduce the cost of communication between the simulators. However, none of the techniques adequately solve the problem of the cost of inter-thread communication or inter-processor communication between a continuous system and a discrete system in a simulation system.
Therefore, it is an object of the present invention to reduce the cost of communication between a continuous system and a discrete system in a simulation system.
It is another object of the present invention to provide a simulation system in which a continuous system and a discrete system appropriately operate with only infrequent synchronization between them.
To solve the problem described above, the inventors have made studies and focused attention on a peripheral portion of discrete-event simulators such as ECU emulators. As illustrated in FIG. 1 , an ECU emulator includes a CPU emulator portion and a peripheral portion. The inventors considered that this is where the bottleneck of communication cost exists.
As a result of the studies, the inventors conceived the idea of allowing at least a portion of the peripheral of the ECU emulator to operate in the same thread as the continuous system. Since the continuous system and a portion of the peripheral operate in the same thread, the configuration achieves low communication cost.
Although inter-thread communication between the peripheral and the ECU emulator is still required, such communication occurs only sparsely such as at interrupt events or periodic access at long regular intervals and therefore places only a little load in terms of communication cost.
According to another feature of the present invention, a continuous system and a discrete system appropriately operate with only infrequent synchronization between them. Specifically, according to a first embodiment of the present invention, a discrete system operates independently of a clock of a continuous system. The discrete system can access a clock module of the continuous system and accesses the clock module only when the discrete system requires a time instant of the clock module. Accordingly, the system places little load in terms of communication cost.
According to a second embodiment of the present invention, a discrete system can access a clock module of a continuous system at a clock pulse out of a certain number of clock pulses (for example 1/1000) of the continuous system for maintaining synchronization with the continuous system. The second embodiment is used when a software timer (time calculation) is used in the discrete system. Operation of the software timer is guaranteed by synchronization at intervals smaller than the minimum granularity of the software timer.
According to the present invention, the frequency of inter-thread communications between a discrete system and a continuous system is significantly reduced since at least a portion of a peripheral of the discrete system is incorporated in the continuous system so that the portion operates in the same thread as the continuous system. Accordingly, the cost of inter-thread communication is significantly reduced to remarkably improve the operation speed of the simulation system.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a functional block diagram of a typical conventional simulation system including a discrete system and a continuous system.
FIG. 2 illustrates a timing chart of the simulation system in FIG. 1 .
FIG. 3 illustrates an exemplary feedback closed loop system, which is a typical control of an ECU.
FIG. 4 illustrates an exemplary description of the feedback closed loop system using response functions.
FIG. 5 is a block diagram of hardware of a computer used for carrying out the present invention.
FIG. 6 illustrates a functional block diagram of a simulation system according to an embodiment of the present invention.
FIG. 7 illustrates a timing chart of the simulation system in FIG. 6 .
FIG. 8 illustrates a more detailed functional block diagram of the simulation system according to the embodiment of the present invention.
FIG. 9 illustrates flowcharts of process of operations of a continuous system and a hybrid peripheral.
FIG. 10 illustrates an ordered list of components of the hybrid peripheral.
FIG. 11 illustrates a flowchart of a process of operation of an interrupt controller.
FIG. 12 illustrates a flowchart of a process of operation of an advanced timer unit.
FIG. 13 illustrates flowcharts of process of operations of a continuous system and a hybrid peripheral in another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A configuration and processes of embodiments of the present invention will be described below with reference to drawings. Like elements are given like reference numerals in the following description and throughout the drawings unless otherwise specified. Configurations and processes described herein are provided as exemplary embodiments and are not intended to limit the technical scope of the present invention to the embodiments.
Prior to describing a configuration for carrying out the present invention, an ECU will be described for understanding of the present invention. An ECU in general includes an input interface which converts an analog signal input from a sensor to a digital signal, a logic unit (microcomputer) which processes the digital input signal according to a predetermined logic, and an output interface which converts the processed signal to an actuator activation signal.
For convenience of explanation, the present invention will be described with respect to ECUs for automobile. However, it should be understood that the present invention is not limited to this and is applicable to mechatronics mechanisms in general such as aircraft and robots that have other ECUs.
ECUs receive as signals the status of surroundings and an environment, the status of a driving mechanism such as an engine, and instructions and actions from a human operator detected by sensors. Specifically, examples of signals include signals from a water temperature sensor, an inlet temperature sensor, a charging pressure sensor, a pump angle sensor, a crank angle sensor, a vehicle speed sensor, an accelerator position sensor, an A/T shift position, a starter switch, and an air conditioner ECU.
The ECUs receive the signals and output signals that drive components such as an electromagnetic spill valve, a fuel cut solenoid, a timing control valve, an inlet throttle VSV, a glow plug relay, a tachometer, and an air conditioner relay.
While it is not impossible to enable a single ECU to output drive signals for controlling different mechanisms, it is not efficient that a single CPU controls components that differ in responsivity and precision of control, such as an engine and an air conditioner. Therefore, typically multiple ECUs are provided in an automobile.
FIG. 3 illustrates an exemplary feedback closed loop system, which is a typical control of an ECU. In FIG. 3 , a target signal is input into the controller 302 , which is an ECU. The ECU internally processes the target signal to provide a drive signal, which drives a plant 304 such as an engine which is a model to be controlled. An output from the plant 304 is fed back to an input of the controller 302 through a sensor 306 .
The target signal provided may be a parameter such as the degree of throttle opening, idle control, brake force, shift, starter on/off, battery voltage, injection energization time, the number of injection energizations, deposit, dwell angle, advance angle, inlet completion flag, ignition completion flag, atmospheric pressure, the weight of the vehicle, rolling resistance coefficient, road gradient, adhesion coefficient, and inlet temperature.
The sensor signal fed back may be the degree of throttle opening, inlet pressure, the amount of inlet air, shift, engine RPM, vehicle speed, exhaust temperature, O 2 , cooling water temperature, air-fuel ratio, knock, or abnormal ignition.
The ECU may control a mechanical system that can be solved by a Newtonian mechanics equation or an electric drive circuit that can be solved by an electric circuit response equation, or a combination of these. They are basically differential equations. According to control engineering, these equations can be transformed by Laplace transform to response functions which can be described.
FIG. 4 illustrates an exemplary description using such response functions. The block enclosed in a dashed box 402 in FIG. 4 corresponds to the controller 302 in FIG. 3 , the block enclosed in a dashed box 404 corresponds to the model to be controlled 304 , and the block 406 corresponds to the sensor 306 . It should be understood that FIG. 4 illustrates an example of a representation using response functions and is not intended to limit the present invention.
Hardware of a computer used for carrying out the present invention will be described with reference to FIG. 5 . In FIG. 5 , multiple CPUs, CPU 0 504 a , CPU 1 504 b , CPU 2 504 c and CPU 3 504 d are connected onto a host bus 502 . Also connected onto the host bus 502 is a main memory 506 used by CPU 0 504 a , CPU 1 504 b , CPU 2 504 c and CPU 3 504 d for computations.
A keyboard 510 , a mouse 512 , a display 514 , and a hard disk drive 516 are connected onto an I/O bus 508 . The I/O bus 508 is connected to the host bus 502 through an I/O bridge 518 . The keyboard 510 and the mouse 512 are used by an operator for entering commands and performing operations such as clicking on a menu. The display 514 is used for displaying menus for operating a program according to the present invention, which will be described later, through a GUI as needed.
Preferable hardware of the computer system used for the present purpose is IBM (R) System X. For that case, CPU 0 504 a , CPU 1 504 b , CPU 2 504 c and CPU 3 504 d may be Intel (R) Core 2 DUO, for example, and an operating system may be Windows (trademark) Server 2003, for example. The operation system is stored in the hard disk drive 516 and is loaded from the hard disk drive 516 onto the main memory 506 during startup of the computer system.
While four CPUs are illustrated here, the number of CPUs is not limited to four. A single-processor system, or a multi-core or multi-processor system including any number of cores or processors may be used.
Hardware of the computer system that can be used for carrying out the present invention is not limited to IBM (R) System X; any computer system on which a simulation program of the present invention can be run can be used. The operating system is not limited to Windows (R); any operating system such as Linux (R) or Mac OS (R) may be used. Furthermore, in order to allow logical processes such as ECU emulator programs and plant simulators to operate fast, a POWER (trademark) 6-based computer system such as IBM (R) System P on which an AIX (trademark) operating system is running may be used.
Multiple logical processes such as ECU emulators and plant simulators, and a program for causing the multiple logical processes to cooperate are also stored in the hard disk drive 516 and can be activated and operated using the keyboard 510 and the mouse 512 .
Preferably, emulator programs for all ECUs used in one automobile are stored in the hard disk drive 516 for implementing full-vehicle SILS.
Also stored in the hard disk drive 516 are a scheduler for ECU emulator programs, which will be described later, plant simulator programs for an engine, transmission, steering, wipers and other components, a global time manger for managing time instants for the whole system, and a scenario generator program containing scenarios for testing, such as upslope, express way, and winding road scenarios.
The terms “emulator” and “simulator” are used herein as follows. Causing an original ECU code intended to run on a different processor to run on a target such as CPU 0 to CPU 3 is referred to as emulation and a program that performs such emulation is referred to as an emulator. A system that virtually computes operations of a physical system such as an engine is referred to as a simulator.
A functional logic block diagram of a simulation system according to the present invention including a discrete system and a continuous system will be described below with reference to FIG. 6 . The discrete-event simulator of the system includes ECU emulators 602 , 604 and 606 . While the system actually includes more ECU emulators, only three ECU emulators are depicted for illustrative purposes.
Program modules illustrated in FIG. 6 are stored in the hard disk drive 516 , and are loaded from the hard disk drive 516 onto the main memory 506 during startup of the simulation system and run by operation of an operating system.
The ECU emulators 602 , 604 and 606 are about identical to one another in function and therefore only the ECU emulator 602 will be described as a representative example. The ECU emulator 602 includes a CPU emulator 602 a and a hybrid peripheral 602 b.
Bridges 608 , 610 and 612 are logic blocks each executes functions of a data input and output section of a plant simulator such as an engine simulator. The bridges 608 , 610 and 612 communicate with the hybrid peripherals 602 b , 604 b and 606 b , respectively, at intervals Δt of a clock of the continuous plant simulator.
Dashed rectangular blocks in FIG. 6 represent separate threads of the simulation program. In a multi-core or multi-processor environment, preferably the individual threads are assigned to separate cores or processors.
As illustrated in FIG. 6 , the hybrid peripherals 602 b , 604 b and 606 b function as interfaces between CPU emulators 602 a , 604 a and 606 a , respectively, and the bridges 608 , 610 and 612 , respectively, for the ECU emulators 602 , 604 and 606 , respectively. The hybrid peripherals 602 b , 604 b and 606 b as modules are controlled so as to operate across the threads in which the plant simulators in which the plant simulators and the bridges 608 , 610 and 612 exist and operate and the threads in which the ECU emulators 602 , 604 and 606 operate. The name “hybrid” of the hybrid peripherals is derived from the fact that they are such coresident existences. Specifically, a portion of each hybrid peripheral exists within the same thread as the ECU emulator 602 , 604 and 606 and another portion of the hybrid peripheral exists in the same thread as the plant simulator.
As illustrated, the hybrid peripherals 602 b , 604 b and 606 b include shared memories 602 c , 604 c and 606 c , respectively, for data read and write. The memories 602 c , 604 c and 606 c are preferably areas of the main memory 506 . Data can be read from and written on the memories by blocks making up the hybrid peripherals, and the ECU emulators.
FIG. 7 schematically illustrates a timing chart for the simulation system illustrated in the functional block diagram of FIG. 6 . As illustrated, a continuous simulator such as a plant simulator and a hybrid peripheral communicate with each other at clock intervals Δt and therefore the communication is dense. However, according to the present invention, since the plant simulator and a portion of the hybrid peripheral are within the same thread, inter-thread communication does not occur between them and excessive communication cost is not incurred.
On the other hand, communication between the hybrid peripheral and the ECU emulator, which is a discrete-event simulator, occurs only at the timings of interrupts in the discrete-event simulator or scheduled, sparse timings. Communication from the hybrid peripheral to the ECU emulator is accomplished by transmission of an event signal.
FIG. 8 illustrates a more detailed function block diagram of the simulation system. It should be understood that while only the block diagram relating to the ECU emulator 602 and the bridge 608 are illustrated, the block diagram is the same for the ECU emulators 604 , 606 and the bridges 610 , 612 .
In FIG. 8 , a ROM 802 and a RAM 804 are connected to the CPU emulator 602 a . Since the simulation system described herein is basically an SILS, all functional blocks are implemented by software modules. Accordingly, the ROM 802 is just a set of constant declarations and the RAM 804 is a memory area allocated in the main memory 506 .
Operation of the CPU emulator 602 a may be execution of a binary code generated by reassembling a code generated by disassembling a binary code of an original emulator program or may be execution of binary instructions of an emulator program while converting the instructions stepwise in sequence.
As illustrated in FIG. 8 , the hybrid peripheral 602 b includes an interrupt controller (INT-C) 806 , an advanced timer unit (ATU) 808 , a pin function controller (PFC) 810 , and a watch dog timer (WDT) 812 .
It should be understood that the configuration including the INT-C 806 , the ATU 808 , the PFC 810 and the WDT 812 is one exemplary configuration of the hybrid peripheral 602 b and the configuration of the hybrid peripheral is not limited to this.
The bridge 608 uses a variable mapping function to convert a signal input to the bridge 608 to a value to be provided to a pin of the PFC 810 . The conversion can be represented by a C-like pseudo code, for example, as given below:
switch (link_type) {
case NE_PULSE:
data.pi0 = link_value;
break;
case A_F:
data.pe23 = link_value;
break;
...
}
That is, a value given to link_type provides the value to an element of a different structure, “data”. Here, NE_PULSE is a pulse representing the RPM of an engine. In one example of real vehicle, 24 pulses occur per rotation of the crankshaft. A_F is air-fuel ratio, which is the ratio of the amount of air to the amount of fuel in the cylinder. It should be understood that these are illustrative only and there are many other signals in practice.
The PFC 810 includes the function of multiplexing data provided from the bridge 608 as a variable corresponding to the pin by the variable mapping function and providing the resulting data to the INT-C 806 or the ATU 808 .
The INT-C 806 sends an event to the CPU emulator 602 a in response to a change of a value or state provided to the PFC 810 in each clock interval. The event includes a parameter value provided from the PFC 810 .
A time instant of the ATU 808 is updated according to a signal from the bridge. On the other hand, the CPU emulator 602 a sets start timing and duration in the ATU 808 on the basis of the result of computation by the CPU emulator 602 a . The ATU 808 generates pulses based on the start timing and the duration received and sends the pulses to the continuous system in time slices. Examples of timing and duration calculated in this way include the start timing and duration of fuel injection.
The WDT 812 is a timer that constantly counts up and, in response to a signal from the CPU emulator 602 a , clears its count value. If the count value exceeds a threshold value because the WDT 812 has received no signal from the CPU emulator 602 a for a predetermined period of time, the WDT 812 outputs a signal indicating that the CPU emulator 602 a is not properly operating.
FIG. 9 is a flowchart of a process of operations of the hybrid peripheral 602 b and the CPU emulator 602 a . It should be understood that operations of the hybrid peripheral 604 b and the CPU emulator 604 a are substantially the same as the operations. The hybrid peripheral 602 b and the CPU emulator 602 a will be described here as a representative example.
The process is invoked in each time slice Δt. The process can be said to be asynchronous in that the discrete-event simulator does not synchronize to a pulse of the continuous simulator.
At steps 902 and 908 in FIG. 9 , processes specific to component blocks making up the peripheral are performed in the order of the ordered component blocks of the peripheral. The term “component block” here refers to the INT-C 806 , ATU 808 , PFC 810 , and WDT 812 in the example in FIG. 8 . The order is determined according to an ordered list 1002 as illustrated in FIG. 10 . The list is preferably provided in a predetermined location in the main memory 506 . The list indicates the order is PFC→ATU→WDT→INT-C. FIG. 10 also indicates that the process should be performed in the order on the list, from the input to output of the continuous system.
In particular, step 902 includes step 904 in which data is read from the shared memory 602 c of the hybrid peripheral 602 b as an output from the CPU emulator 602 a and step 906 in which data is written over data in the shared memory 602 c of the hybrid peripheral 602 b as an input from the CPU emulator 602 a.
When the process is completed for all component blocks, the process of the hybrid peripheral 602 b (in particular the continuous system portion) ends.
On the other hand, the CPU emulator 602 a performs the process at step S 910 up to the point immediately before I/O access. At step 912 , the CPU emulator 602 a makes I/O access to the shared memory 602 c of the hybrid peripheral 602 b . During the access to the shared memory 602 c , exclusive control is performed to prevent any other process block from overwriting a value in the shared memory 602 c.
FIG. 11 illustrates a flowchart of a process performed by the INT-C 806 of the hybrid peripheral 602 b . The process is the process specific to INT-C 806 performed at peripheral-component-block-specific process step 910 of FIG. 9 . At step 1102 of FIG. 11 , the INT-C takes in input data from the PFC 810 . At step 1104 , the INT-C determines whether or not the input data is to be converted to an interrupt. For example, a value previous to a certain value may be held and the determination may be made on the basis of whether or not the value has been changed from the previous value. Typically, a falling edge of a pulse is detected.
If the INT-C determines to convert the input data to an interrupt, the INT-C sends an interrupt event message to the CPU emulator at step 1106 , and then the process will end.
FIG. 12 illustrate a flowchart of the ATU 808 of the hybrid peripheral 602 b . The process is specific to the ATU 808 performed at the peripheral-component-block-specific process step 910 of FIG. 9 . At step 1202 of FIG. 12 , the ATU takes in input data from the PFC.
At step 1204 , the ATU determines whether or not the timer has hit, that is, the value of the timer has reached a predetermined value. If so, the ATU changes the status of the output at step 1206 ; otherwise, the process immediately proceeds to step 1208 .
Then, at step 1208 , the ATU writes the output data in the PFC, and then the process will end.
More specifically, start time and duration can be set in the ATU 808 from the CPU emulator 602 a . A timer hit at step 1204 means that it is within the duration from the start time. The ATU 808 outputs a logical 1, for example, during the duration from the start time through the PFC and outputs a logical 0 in other times.
FIG. 13 illustrates a flowchart of a process according to another embodiment relating to process of operations between a peripheral and an ECU emulator. The process of the embodiment differs from the process in FIG. 9 in that a synchronization process is performed in each specified cycle in the embodiment. The process in the flowchart of FIG. 13 is invoked in each time slice Δt. The embodiment is employed when a software timer (time calculation) is used in a discrete system. Operation of the software timer is guaranteed by synchronization at intervals smaller than the minimum granularity of the software timer.
At steps 1302 and 1308 in FIG. 13 , processes specific to component blocks making up the peripheral are performed in the order of the ordered component blocks of the peripheral. The term “component block” here refers to the INT-C 806 , ATU 808 , PFC 810 , and WDT 812 in the example in FIG. 8 . The order is determined according to an ordered list 1002 as illustrated in FIG. 10 . The list is preferably provided in a predetermined location in the main memory 506 . The list indicates the order is PFC→ATU→WDT→INT-C. FIG. 10 also indicates that the process should be performed in the order on the list, from the input to output of the continuous system.
Processes specific to the INT-C 806 and ATU 808 are performed in the same way as the processes described with respect to FIGS. 11 and 12 , respectively.
In particular, step 1302 includes step 1304 in which data is read from the shared memory 602 c of the hybrid peripheral 602 b as an output from the CPU emulator 602 a and step 1306 in which data is written over data in the shared memory 602 c of the hybrid peripheral 602 b as an input from the CPU emulator 602 a.
When the process is completed for all component blocks, the process of the hybrid peripheral 602 b proceeds to step 1310 , where determination is made as to whether or not t≦T<t+Δt. If not, the process immediately ends. Here, t represents the current time in the continuous system, Δt represents the size of a time slice, and T represents the synchronization time of the CPU emulator.
If it is determined at step 1310 that t≦T<t+Δt, the hybrid peripheral 602 b waits for a notification from the CPU emulator 602 a at step 1312 . Upon arrival of the notification, the hybrid peripheral 602 b updates T and notifies the CPU emulator 602 a of the update at step 1314 .
On the other hand, the CPU emulator 602 a performs the process at S 1316 up to the point immediately before I/O access. At step 1318 , the CPU emulator 602 a makes I/O access to the shared memory 602 c of the hybrid peripheral 602 b . During the access to the shared memory 602 c , exclusive control is performed to prevent any other process block from overwriting a value in the shared memory 602 c.
At step 1320 , determination is made as to whether the specified cycle has ended or not. If not, the process returns to step 1316 .
When it is determined at step 1320 that the specified cycle has ended, the CPU emulator 602 a notifies the hybrid peripheral 602 b of the end of the cycle at step 1322 . The notification is the notification from the CPU emulator 602 a at step 1312 described above.
At step 1324 , the CPU emulator 602 a waits for specification of the next cycle, which is the notification at step 1314 described above. Then the process returns to step 1316 .
While particular embodiments of the present invention have been described with respect to multiple simulation systems for automobile, it will be apparent to those skilled in the art that the present invention is not limited to the particular embodiments but is applicable to simulation systems for electronic machine control systems in general.
While a peripheral portion of an ECU emulator and a continuous system exist within the same thread in the embodiments described above, they may exist in a wider unit, a process, that can be allocated to a single processor or core. | A simulation system, method, and article of manufacture. A simulation system has a discrete and a continuous portion. The discrete portion further has a peripheral emulator in communication with the continuous portion of the simulation system. A portion of a peripheral emulator is separated and is caused to operate in a thread of a continuous system. The continuous system and the peripheral are in loose synchronization and therefore sparsely communicate with each other. The configuration significantly reduces the frequency of inter-thread communications between the continuous system and the discrete system that are performed in response to a continuous clock in a simulation system including the continuous system and the discrete system, thereby reducing communication cost. Accordingly, the operation speed of the simulation system can be increased. | 8 |
SUMMARY OF THE INVENTION
This invention relates to new derivatives of 8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine and salts thereof. These new compounds have the general formula ##STR2## R 1 is hydrogen, lower alkyl, phenyl, phenyl-lower alkylene, benzoyl or substituted benzoyl.
R 2 and R 3 each is hydrogen, lower alkyl or phenyl.
R 4 is hydrogen, lower alkyl, phenyl, carboxy or lower alkoxycarbonyl.
R 5 is lower alkoxy, substituted lower alkoxy wherein the substituent is ##STR3## phenyl-lower alkoxy, phenyloxy, substituted phenyloxy wherein the phenyl ring bears one or two simple substituents including lower alkyl, halogen or trifluoromethyl (preferably only one), halo, the group ##STR4## or the group --S--R 9 . R 6 is hydrogen or lower alkyl.
R 7 is hydrogen, lower alkyl or substituted lower alkyl wherein the lower alkyl substituent is ##STR5## phenyl or substituted phenyl wherein the phenyl wherein the phenyl substituent is halogen, lower alkyl or trifluoromethyl, R 8 is hydrogen or lower alkyl. When R 7 is substituted lower alkyl, R 8 is preferably hydrogen. In addition R 7 and R 8 together with the nitrogen may form an unsubstituted or substituted heterocyclic radical including pyrrolidino, morpholino, thiamorpholino, piperidino, pyrazolyl, dihydropyridazinyl or piperazinyl wherein the substituent on the heterocycle is lower alkyl or hydroxy-lower alkyl.
R 9 , R 10 and R 11 each is hydrogen or lower alkyl.
DETAILED DESCRIPTION OF THE INVENTION
The various groups represented by the symbols are of the following types and have the same meanings throughout this specification:
The lower alkyl groups are straight or branched chain hydrocarbon groups having up to seven carbon atoms like methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl and the like. The lower alkylene groups are divalent radicals of the same kind. Examples of the phenyl-lower alkylene groups are benzyl, phenethyl, phenylisopropyl and the like. The C 1 -C 4 and especially the C 1 -C 2 lower alkyl and lower alkylene groups are preferred. The lower alkoxy groups are of the same type. The C 1 -C 4 and C 1 -C 2 groups are similarly preferred and especially preferred groups, respectively.
The substituted phenyloxy and substituted benzoyl groups (i.e., R 12 -phenyloxy, R 12 -benzoyl) are simply substituted groups bearing on the phenyl ring one or two (preferably one), lower alkyl or trifluoromethyl groups (R 12 ), for example, p-chlorophenyloxy, o-chlorophenyloxy, p-bromophenyloxy, m-chlorophenyloxy, m-bromophenyloxy, p-tolyloxy, o-tolyloxy, o-ethylphenyloxy, p-trifluoromethylphenyloxy, 3,4-dichlorophenyloxy, 3,5-dimethylphenyloxy, p-bromobenzoyl, m-bromobenzoyl, 3,5-dichlorobenzoyl, p-methylbenzoyl, o-ethylbenzoyl, p-trifluoromethylbenzoyl and the like. Chlorine, bromine and methyl are the preferred substituents (only one) in both instances.
The halogens in each instance are the four common halogens but chlorine and bromine, especially chlorine, are preferred.
The amino group ##STR6## wherein R 7 and R 8 each represents hydrogen or lower alkyl include the amino group, lower alkylamino groups like methylamino, ethylamino, propylamino, isopropylamino, butylamino, etc., and di-lower alkylamino groups like dimethylamino, diethylamino, methylethylamino, dipropylamino, dibutylamino and the like (preferably, but not necessarily, both lower alkyl groups are the same in a given compound). R 7 and R 8 can also join with the nitrogen to form one of the heterocyclic radicals pyrrolidino, morpholino, thiamorpholino, piperidino, pyrazolyl, dihydropyridazinyl or piperazinyl. These heterocyclic radicals may be unsubstituted or substituted with a lower alkyl or hydroxy-lower alkyl group (R 13 ). The preferred heterocyclics are piperidino, morpholino and 4-methylpiperazino.
The substituted lower alkoxy groups represented by R 5 and the substituted lower alkylamino groups represented by R 7 may bear an amino group ##STR7## as described above resulting in R 5 substituents which are amino-lower alkoxy groups ##STR8## and amino-lower alkyleneamino groups ##STR9## respectively, including, for example, aminomethoxy, aminoethoxy, aminopropoxy, methylaminoethoxy, ethylaminoethoxy, ethylaminopropoxy, dimethylaminomethoxy, dimethylaminoethoxy, dimethylaminopropoxy, diethylaminoethoxy, dimethylaminobutoxy, diethylaminopropoxy, aminoethylamino, aminopropylamino, methylaminopropylamino, ethylaminoethylamino, dimethylaminomethylamino, diethylaminomethylamino, dimethylaminoethylamino, diethylaminoethylamino, dimethylaminopropylamino, and the like. Preferred are those groups wherein the lower alkyl and lower alkylene groups have up to 4 carbons, especially 1 to 2 carbons. Especially preferred group of this type are di-lower alkylamino-lower alkoxy, especially dimethylaminopropoxy and di-lower alkylamino-lower alkyleneamino, especially dimethylaminopropylamino.
Preferred groups of compounds of formula I are those wherein R 1 is hydrogen or lower alkyl, especially the latter and most especially ethyl; R 2 is hydrogen or lower alkyl, especially hydrogen; R 3 is hydrogen or lower alkyl, especially methyl; R 4 is hydrogen or lower alkoxycarbonyl, especially ethoxycarbonyl; R 5 is amino, mercapto, lower alkylmercapto, especially methylmercapto, lower alkylamino, especially C 1 -C 4 -lower alkylamino, lower alkoxy, especially C 1 -C 5 -lower alkoxy, di(lower alkyl)amino, especially C 1 -C 4 -di(lower alkyl)amino, di(lower alkyl)amino-lower alkylamino, especially wherein the lower alkyl groups are C 1 -C 4 and most especially dimethylaminoethylamino and dimethylaminopropylamino, or di(lower alkyl)amino-lower alkoxy, especially wherein the lower alkyl and lower alkoxy groups are C 1 -C 4 and most especially dimethylaminopropoxy. R 6 is hydrogen or lower alkyl, especially hydrogen.
The products of the examples are representative of the various compounds of this invention and constitute especially preferred embodiments.
The new compounds of formula I are formed by the following series of reactions. The symbols in the structural formulas have the same meaning as previously described.
A 4-hydrazinopyrazolo[3,4-b]pyridine-5-carboxylic acid ester of the formula ##STR10## (produced according to the procedure given in U.S. Pat. No. 3,761,487, Sept. 25, 1973) is made to react with a 3-aminocrotonic acid nitrile of the formula ##STR11## or with an alkoxymethylene compound of the formula ##STR12## in a high boiling alcohol like n-butyl alcohol or n-amyl alcohol, or the like, at about reflux temperature.
By this reaction a compound of the formula ##STR13## is formed.
Treatment of the compound of formula V with a base, e.g., an alkali metal alkoxide like sodium ethoxide, potassium ethoxide or the like in alcoholic solution or with a Lewis acid like zinc chloride, boron trifluoride or the like in a solvent like acetic acid yields a compound of the formula ##STR14##
Reaction of the compound of formula VI with a chlorinating agent like phosphorus oxychloride, or phosphorus pentachloride results in the formation of a compound of the formula ##STR15##
Compounds of formula I wherein R 5 is lower alkoxy or amino-lower alkoxy are now produced by reaction of the compound of formula VII with an alcoholate of the formula
R.sup.12 --O--Me (VIII)
wherein Me is an alkali metal like sodium or potassium and R 12 is lower alkyl or amino-lower alkyl ##STR16##
Compounds of formula I wherein R 5 is lower alkylthio are obtained by reaction of a compound of formula VII with an alkali metalmercaptide of the formula
R.sup.12 --S--Me (IX)
wherein Me is again an alkali metal like sodium or potassium and R 12 is lower alkyl. Compounds of formula I wherein R 5 is mercapto are obtained by reaction of a compound of formula VI with an alkali metal sulfide like sodium sulfide. Compounds of formula I wherein R 5 is an amino group or amino-lower alkylene group are produced by reaction of a compound of formula VII with an amine of the formula ##STR17## at elevated temperatures.
When R 4 is lower alkoxycarbonyl, the free carboxylic acid is obtained by hydrolysis, e.g., with a base like sodium hydroxide.
The new compounds of formula I form salts which are also part of this invention. The salts include acid addition salts, particularly the non-toxic, physiologically acceptable members. These salts are formed by reaction with one or more equivalents of a variety of inorganic and organic acids providing acid addition salts including, for example, hydrohalides (especially hydrochloride and hydrobromide), sulfate, nitrate, borate, phosphate, oxalate, tartrate, maleate, citrate, acetate, ascorbate, succinate, aryl- and alkanesulfonates like benzenesulfonate, methanesulfonate, cyclohexanesulfamate and toluenesulfonate, etc. The acid addition salts frequently provide a convenient means for isolating the product, e.g., by forming and precipitating a salt (which is not necessarily non-toxic) in an appropriate medium in which the salt is insoluble, then after separation of the salt, neutralizing with a base such as barium hydroxide or sodium hydroxide, to obtain the free base of formula I. Other salts can then be formed from the free base by reaction with an equivalent or more of acid containing the desired anion.
Additional experimental details are found in the examples.
The new compounds of this invention have central nervous system depressant activity and can be used as psychotropic agents, e.g., as ataractic agents for the relief of anxiety and tension states, for example, in mice, cats, rats, dogs and other mammalian species. For this purpose a compound or mixture of compounds of formula I, or non-toxic, physiologically acceptable acid addition salt thereof, is preferably administered orally, but parenteral routes such as subcutaneously, intramuscularly, intravenously or intraperitoneally in the described dosages, can also be employed. A single dose, or preferably 2 to 4 divided daily doses, provided on a basis of about 5 to 50 mg. per kilogram per day, preferably about 10 to 25 mg. per kilogram per day, is appropriate.
The new compounds of this invention also have anti-inflammatory properties and are useful as anti-inflammatory agents, for example, to reduce local inflammatory conditions such as those of an edematous nature or resulting from proliferation of connective tissue in various mammalian species such as rats, dogs and the like when given orally in dosages of about 1 to 50 mg/kg/day, preferably 2 to 15 mg/kg/day, in single or 2 to 4 divided doses, as indicated by the carageenan edema or delayed hypersensitivity skin reaction tests in rats. They can also be used topically.
The compounds of the invention can be utilized by formulation in compositions such as tablets, capsules or elixirs for oral administration or in sterile solutions or suspensions for parenteral administration. About 10 to 300 mg. of a compound or mixture of compounds of formula I or physiologically acceptable acid addition salt is compounded with a physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage form as called for by accepted pharmaceutical practice. The amount of active substance in these compositions or preparations is such that a suitable dosage in the range indicated is obtained.
Illustrative of the adjuvants which may be incorporated in tablets, capsules and the like are the following: a binder such as gum tragacanth, acacia, corn starch or gelatin; an excipient such as dicalcium phosphate, a disintegrating agent such as corn starch, potato starch, alginic acid and the like; a lubricant such as magnesium stearate; a sweetening agent such as sucrose, lactose or saccharin; a flavoring agent such as peppermint, oil of wintergreen or cherry. When the dosage unit form is a capsule, it may contain in addition to materials of the above type a liquid carrier such as a fatty oil. Various other materials may be present as coatings or to otherwise modify the physical form of the dosage unit. For instance, tablets or capsules may be coated with shellac, sugar or both. A syrup or elixir may contain the active compound, sucrose as a sweetening agent, methyl and propyl parabens as preservatives, a dye and a flavoring such as cherry or orange flavor. Of course, any material used in preparing the dosage unit should be pharmaceutically pure and substantially non-toxic in the amounts employed.
For topical administration as an anti-inflammatory agent, a conventional lotion, ointment or cream containing about 0.1 to 3 percent by weight of a compound of formula I or its salt is formulated.
The following examples are illustrative of the invention and constitute especially preferred embodiments. They also serve as models for the preparation of other members of the group which can be produced by suitable substitution of starting materials. All temperatures are in degrees celsius.
EXAMPLE 1
N-Butyl-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
(a) 4-[2-(2-Cyano-1-methylethylidene)hydrazino]-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester
249 g of 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]-pyridine-5-carboxylic acid, ethyl ester (1 mol) and 82 g of 3-aminocrotononitrile (1 mol) are heated together in 1.5 liters of butyl alcohol with stirring for 24 hours. The solvent is removed in vacuo and the residual 4-[2-(2-cyano-1-methylethylidene)hydrazino]-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester is recrystallized from alcohol, yield 309 g (80%); m.p. 190°-191°.
(b) 8-Ethyl-2-methyl-4H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]-pyrido[3,4-e]pyrimidin-5(8H)-one
309 g of 4-[2-(2-cyano-1-methylethylidene)hydrazino]-1-ethyl-1H-pyrazolo[3,4-e]pyridine-5-carboxylic acid, ethyl ester (0.8 mol) are refluxed with stirring in 1 liter of acetic acid, containing 50 g of zinc chloride, for 24 hours. The solution is cooled to room temperature and after addition of about 1 liter of cold water, 8-ethyl-2-methyl-4H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin5-(8H)-one crystallizes and is filtered off. Purification of the compound is accomplished by dissolving in the theoretical amount of aqueous sodium hydroxide and acidifying the solution with acetic acid, yield 161 g (75%), m.p. 285°-286°.
(c) 5-Chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
161 g of 8-ethyl-2-methyl-4H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4e]pyrimidin-5(8H)-one (0.06 mol) are heated with stirring in 1 liter of phosphorus oxychloride at 80° for 48 hours. The mixture is decomposed by pouring onto crushed ice. The 5-chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is filtered off and recrystallized from butyl alcohol, yield 148 g (86%); m.p. 179°-180°.
(d) N-Butyl-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
5.7 g of 5-chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]-pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine (0.02 mol) are dissolved in 50 ml of dry alcohol. After addition of 1.5 g of n-butylamine, the mixture is heated at reflux temperature with stirring for 12 hours. The solvent is removed and the crystalline residue is treated with water. The N-butyl-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[4,3e]pyrimidin-5-amine is filtered off and recrystallized from ethyl acetate, yield 5 g (77%); m.p. 160°-162°.
EXAMPLE 2
8-Ethyl-2-methyl-N-(1-methylpropyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine, hydrate (1:1)
By substituting 1-methylpropylamine for the n-butylamine in the procedure of Example 1d, 8-ethyl-2-methyl-N-(1-methylpropyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]-pyrimidin-5-amine, hydrate (1:1) is obtained in 81% yield, m.p. 94°-97° (alcohol).
EXAMPLE 3
8-Ethyl-2-methyl-N-(1-methylethyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting 1-methylethylamine, for the n-butylamine in the procedure of Example 1d, 8-ethyl-2-methyl-N-(1-methylethyl)-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine is obtained, yield 78%; m.p. 98°-100° (alcohol).
EXAMPLE 4
N-[3-(Dimethylamino)propyl]-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
2.9 g of 5-chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]-pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine (0.01 mol) are dissolved in 30 ml of alcohol. 2.5 g of 3-(dimethylamino)propyl-1-amine are added and the mixture is refluxed for 5 hours. The solvent is distilled off in vacuo and the crystalline residue extracted twice with 50 ml portions of ethyl acetate. The solvent is removed until the volume is about 20 ml and then cooled. N-[3-(dimethylamino)propyl]-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine crystallizes and is filtered off, yield 2.8 g (80%); m.p. 178°-179° (ethyl acetate).
EXAMPLE 5
N-[2-(Dimethylamino)ethyl]-8-ethyl-2-methyl-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting 2-(dimethylamino)ethyl-1-amine for the 3-(dimethylamino)propyl-1-amine in the procedure of Example 4, N-[2-(dimethylamino)ethyl]-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine is formed, yield 75%; m.p. 124°-126° (ethyl acetate).
EXAMPLE 6
8-Ethyl-2-methyl-5-(4-methyl-1-piperazinyl)-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4e]pyrimidine
By substituting 4-methylpiperazine for the 3-(dimethylamino)propyl-1-amine in the procedure of Example 4, 8-ethyl-2-methyl-5-(4-methyl-1-piperazinyl)-8H-pyrazolo[1,5-a]-pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is formed in 69% yield; m.p. 167°-169° (ethyl acetate).
EXAMPLE 7
8-Ethyl-2-methyl-5-(1-piperidinyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting piperidine for the 3-(dimethylamino)propyl-1-amine in the procedure of Example 4, 8-ethyl-2-methyl-5-(1-piperidinyl)-8H-pyrazolo[1,5-a]pyrazolo[4'3,':5,6]pyrido[3,4-e]pyrimidine is obtained, yield 71%; m.p. 176°-177° (alcohol).
EXAMPLE 8
8-Ethyl-2-methyl-5-(4-morpholinyl)-8H-pyrazolo[1,5a]-pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting morpholine for 3-(dimethylamino)propyl-1-amine in the procedure of Example 4, 8-ethyl-2-methyl-5-(4-morpholinyl)8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained, yield 76%; m.p. 179°-180° (alcohol).
EXAMPLE 9
8-Ethyl-2-methyl-N-[3-(trifluoromethyl)phenyl]-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
5.8 g of 5-chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine (0.02 mol), 3 g of triethylamine and 3.3 g of 3-trifluoromethylaniline are refluxed in butyl alcohol for 24 hours with stirring. The solvent is removed in vacuo and the residue treated with 20 ml of water and filtered off. Recrystallization from alcohol yields 6 g of 8-ethyl-2-methyl-N-[3-(trifluoromethyl)phenyl]-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine; yield (73%) m.p. 205°-206°.
EXAMPLE 10
N,N,8-Triethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
8.6 g of 5-chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine (0.03 mol) and 7.2 g of diethylamine are suspended in 50 ml of butyl alcohol and heated with stirring in an autoclave for 10 hours at 150°. After this time, the solvent is removed, the residue is treated with water and filtered off. Recrystallization from alcohol yields 8 g (83%) of N,N,8-triethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine; m.p. 106°-108°.
EXAMPLE 11
8-Ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting aqueous ammonia (70%) for the diethylamine in the procedure of Example 10, 8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine is obtained, yield 69%; m.p. 248°-250° (DMF).
EXAMPLE 12
8-Ethyl-N,2-dimethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting methylamine for the diethylamine in the procedure of Example 10, 8-ethyl-N,2-dimethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine is obtained, yield 76%; m.p. 254°-255° (butyl alcohol).
EXAMPLE 13
5-(Butylamino)-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
(a) 4-[2-(Cyano-3-ethoxy-3-oxo-1-propenyl)hydrazino]-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester
249 g of 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]-pyridine-5-carboxylic acid, ethyl ester (1 mol) are suspended in 1.5 liters of n-butyl alcohol. The mixture is heated with stirring at reflux temperature. At this point, 169 g of ethoxymethylenecyanoacetic acid, ethyl ester (1 mol), dissolved in 500 ml of warm butyl alcohol, are dropped in. After the addition is completed, heating is continued for 2 hours. The solution is cooled in an ice-bath and the precipitated 4-[2-(2-cyano-3-ethoxy-3-oxo-1-propenyl)hydrazino]-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester is filtered off, yield 351 g (94%); m.p. 170°-172° (butyl alcohol).
(b) 8-Ethyl-5,8-dihydro-5-oxo-4H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
351 g of 4-[2-(2-cyano-3-ethoxy-3-oxo-1-propenyl)hydrazino]-1-ethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester are heated in 2 liters of acetic acid containing 50 g of zinc chloride for 24 hours. After this time, the solution is cooled and 2 liters of cold water are added. The precipitated 8-ethyl-5,8-dihydro-5-oxo-4H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is filtered off and purified by dissolving in the theoretical amount of sodium hydroxide in water and precipitating the compound with acetic acid, yield 256 g (83%); m.p. 263°-265°.
(c) 5-Chloro-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
256 g of 8-ethyl-5,8-dihydro-5-oxo-4H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester are refluxed in 1 liter of phosphorus oxychloride for 24 hours. The excess phosphorus oxychloride is decomposed by pouring the solution on ice and the crystallized 5-chloro-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4', 3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is filtered off, yield 245 g (91%); m.p. 170°-172° (butyl alcohol).
(d) 5-(Butylamino)-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
3.5 g of 5-chloro-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester (0.01 mol) and 7.3 g of n-butylamine are refluxed together with 30 ml of alcohol with stirring for 8 hours. The solution is evaporated to dryness and the residue treated with water and filtered off. Recrystallization from ethyl acetate yields 3.2 g (84%) of 5-(n-butylamino)-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester; m.p. 275°-277°.
EXAMPLE 14
5-[(1-Methylpropyl)amino]-8-ethyl-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
By substituting 1-methylpropylamine for the n-butylamine in the procedure of Example 13d, 5-[(1-methylpropyl)amino]-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is obtained, yield 71%; m.p. 94°-97°. Hydrolysis with aqueous sodium hydroxide solution yields the free carboxylic acid.
EXAMPLE 15
8-Ethyl-5-(methylamino)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
3.5 g of 5-chloro-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester (0.01 mol) and 3.5 g of methylamine are heated in 50 ml of alcohol in an autoclave for 10 hours at 100°. The solvent is removed in vacuo and the residue treated with water, filtered off and recrystallized from butyl alcohol, yield 2.9 g (86%); m.p. 321°-322°.
EXAMPLE 16
5-(Diethylamino)-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
By substituting diethylamine for the methylamine in the procedure of Example 15, 5-(diethylamino)-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is formed, yield 73%; m.p. 170°-172° (alcohol).
EXAMPLE 17
5-Amino-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
By substituting an equivalent amount of 30% aqueous ammonia for the methylamine in the procedure of Example 15, 5-amino-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is formed, yield 68%; m.p. 331°-332° (DMF).
EXAMPLE 18
8-Ethyl-5-(4-methyl-1-piperazinyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
3.5 g of 5-chloro-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester (0.01 mol) are dissolved in 20 ml of butanol. 2 g of N-methylpiperazine are added and the solution is refluxed with stirring for 12 hours. After evaporation of the solvent, the residue is extracted three times with 50 ml portions of ethyl acetate. The ethyl acetate is distilled off until the volume is about 30 ml. The 8-ethyl-5-(4-methyl-1-piperazinyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester crystallizes, yield 3.1 g (76%); m.p. 111°-113° (ethyl acetate).
EXAMPLE 19
8-Ethyl-5-(1-piperidinyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
By substituting piperidine for the N-methylpiperazine in the procedure of Example 18, 8-ethyl-5-(1-piperidinyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is obtained, yield 2.6 g (67%); m.p. 183°-184° (ethyl acetate).
EXAMPLE 20
5-[[3-(Dimethylamino)propyl]amino]-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
By substituting 3-(dimethylamino)propylamine for the N-methylpiperazine in the procedure of Example 18, 5-[[3-(dimethylamino)propyl]amino]-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is obtained, yield 62%; m.p. 212°-215° (ethyl acetate).
EXAMPLE 21
5-[3-(Dimethylamino)propoxy]-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
To a suspension of 3.6 g of sodium hydride in 100 ml of dry benzene 15.3 g of 3-(dimethylamino)propanol are added and the mixture is refluxed for 6 hours. After this time, 28.6 g of 5-chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine are added in small portions with stirring. The solution is refluxed for 10 hours, and then the solvent is distilled off. The residue is treated with water, filtered off and recrystallized from ethyl acetate, yield 25 g (71%); m.p. 62°-64°.
EXAMPLE 22
5-Butoxy-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting n-butyl alcohol for the 3-(dimethylamino)propanol in the procedure of Example 21, 5-butoxy-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained, yield 71%; m.p. 103°-104° (methanol).
EXAMPLE 23
8-Ethyl-2-methyl-5-(1-methylethoxy)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting 2-propanol for the 3-(dimethylamino)propanol in the procedure of Example 21, 8-ethyl-2-methyl-5-(1-methylethoxy)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained, yield 68%; m.p. 129°-130° (ethyl acetate).
EXAMPLE 24
8-Ethyl-2-methyl-5-(3-methylbutoxy)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting 3-methylbutyl alcohol for the 3-(dimethylamino)propanol in the procedure of Example 21, 8-ethyl-2-methyl-5-(3-methylbutoxy)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained, yield 67%; m.p. 60°-62° (ethyl acetate).
EXAMPLE 25
5-Ethoxy-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
2.3 g of sodium are dissolved in 100 ml of dry alcohol with stirring. The solution is heated at reflux temperature and, at this point, 28.6 g of 5-chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine are added in small portions. Heating and stirring is continued for 6 hours. The precipitated sodium chloride is filtered off, the solvent is removed and the residual 5-ethoxy-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is recrystallized from methanol, yield 82%; m.p. 142°-144°.
EXAMPLE 26
5-[3-(Dimethylamino)propoxy]-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
To a suspension of 3.6 g of sodium hydride in 100 ml of dry benzene 15.3 g of 3-(dimethylamino)propanol are added dropwise at reflux temperature with stirring. Heating is continued for 10 hours. After this time, 34.4 g of 5-chloro-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester are added and the solution is refluxed for 5 additional hours. The solution is evaporated to dryness and the residue is treated with water, filtered off and recrystallized from ethyl acetate. 12 g of 5-[3-(dimethylamino)propoxy]-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester are obtained (29.3%); m.p. 106°-107°.
EXAMPLE 27
8-Ethyl-5-(3-methylbutoxy)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
By substituting 3-methylbutyl alcohol for the 3-(dimethylamino)propanol in the procedure of Example 26, 8-ethyl-5-(3-methylbutoxy)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is obtained, yield 61%; m.p. 117°-118° (ethyl acetate). Hydrolysis with aqueous sodium hydroxide yields the free carboxylic acid.
EXAMPLE 28
5-Ethoxy-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
By substituting for the 5-chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine in the procedure of Example 25 5-chloro-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester, 5-ethoxy-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is formed, yield 75%; m.p. 167°-168° (alcohol).
EXAMPLE 29
8-Ethyl-2-methyl-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-5-thiol
5.6 g of 5-chloro-8-ethyl-2-methyl-4H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine (0.02 mol) are dissolved in 100 ml of dimethylformamide. 2 g of powdered sodium sulfite are added and the mixture is stirred for 1 hour. After this time, the solution is carefully acidified with acetic acid. 8-Ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-5-thiol precipitates and is filtered off, yield 5.1 g (91%); m.p. 320°-322° (DMF).
EXAMPLE 30
8-Ethyl-5-mercapto-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester
By substituting for the 8-ethyl-2-methyl-4H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5(8H)-one in the procedure of Example 29 5-chloro-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester, 8-ethyl-5-mercapto-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-3-carboxylic acid, ethyl ester is formed, yield 86%; m.p. 238°-240° (DMF).
EXAMPLE 31
8-Ethyl-2-methyl-5-(methylthio)-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
5.6 g of 5-chloro-8-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine (0.02 mol) and 3 g of sodium methylmercaptide are refluxed together in 50 ml of dimethylformamide with stirring for 2 hours. The mixture is cooled to room temperature and diluted with 50 ml of water. 8-Ethyl-2-methyl-5-(methylthio)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is filtered off and recrystallized from butyl alcohol, yield 3.5 g (59%); m.p. 168°-169°.
EXAMPLE 32
N-Butyl-2-methyl-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine,
By substituting an equivalent amount of 4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester in the procedure of Example 1 a and continuing as in parts b, c and d, 5-chloro-2-methyl-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine and N-butyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine respectively, are obtained.
EXAMPLE 33
N,2,8,10-Tetramethyl-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting 1,3-dimethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester in the procedure of Example 1 a and proceeding as in parts b and c, and substituting methylamine for the butylamine in part d, 5-chloro-2,8,10-trimethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine and N,2,8,10-tetramethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine are obtained.
EXAMPLE 34
2,3-Diethyl-8-isopropyl-5-phenoxy-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting 1-isopropyl-4-hydrazino-1H-pyrazolo[3,4b]pyridine-5-carboxylic acid, ethyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester and 3-amino-2-ethyl-2-pentenonitrile for the 3-aminocrotononitrile in the procedure of Example 1 a, proceeding as in parts b and c, then following the procedure of Example 21 but substituting phenol for the 3-(dimethylamino)propanol, 5-chloro-2,3-diethyl-8-isopropyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine and 2,3-diethyl-8-isopropyl-5-phenoxy-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine, respectively, are obtained.
EXAMPLE 35
5-(4-Chlorophenyloxy)-10-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting 4-hydrazino-3-ethyl-1H-pyrazolo1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid propyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester in the procedure of Example 1 a, proceeding as in parts b and c, then following the procedure of Example 21 but substituting 4-chlorophenol for the 3-(dimethylamino)propanol, 5-chloro-10-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine and 5-(4-chlorophenyloxy)-10-ethyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine, respectively, are obtained.
EXAMPLE 36
5-Benzyloxy-2-methyl-8-phenyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting 4-hydrazino-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester in the procedure of Example 1 a, proceeding as in parts b and c, then proceeding as in Example 21 but substituting phenylmethanol for the 3-(dimethylamino)propanol, 5-chloro-2-methyl-8-phenyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine and 5-benzyloxy-2-methyl-8-phenyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine, respectively, are obtained.
EXAMPLE 37
N-Butyl-8-ethyl-2,6-dimethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting 1-ethyl-4-hydrazino-6-methyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester in the procedure of Example 1, 5-chloro-2,6-dimethyl-8-ethyl-8H-pyrazolo[1,5a]pyrazolo[4',3':5,6]pyrido[3,4e]pyrimidine and N-butyl-8-ethyl-2,6-dimethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-5-amine, respectively, are obtained.
EXAMPLE 38
8-Benzyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-thiol
By substituting 1-benzyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester in the procedure of Example 1 a, proceeding as in part b, then proceeding as in Example 29, 8-benzyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine-5-thiol is obtained.
EXAMPLE 39
N-Butyl-8-phenylethyl-3-propyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting 1-phenylethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, methyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester and 2-aminomethylenepentanonitrile for the 3-aminocrotonitrile in the procedure of Example 1 a and proceeding as in parts b, c and d, 5-chloro-8-phenylethyl-3-propyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine and N-butyl-8-phenylethyl-3-propyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin5-amine, respectively, are obtained.
EXAMPLE 40
N-butyl-8-ethyl-2-phenyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting 3-amino-3-phenylcrotononitrile for the 3-aminocrotononitrile in the procedure of Example 1 a and proceeding as in parts b, c and d, 5-chloro-8-ethyl-2-phenyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine and N-butyl-8-ethyl-2-phenyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine, respectively, are obtained.
EXAMPLE 41
8-Benzoyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5(8H)-one
(a) N-Butyl-8-furfuryl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting 4-hydrazino-1-furfurylpyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester in Example 1 a and proceeding as in parts a and b, 8-furfuryl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5(8H)-one is obtained. This compound is now processed as in Example 1, parts c and d to obtain N-butyl-8-furfuryl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine.
(b) N-Butyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]-pyrido[3,4-e]pyrimidin-5-amine
0.01 mol of N-butyl-8-furfuryl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine is heated in 50 ml of diethyleneglycol dimethyl ether containing 0.01 mol of selenium dioxide at reflux temperature with stirring for two hours. The mixture is filtered hot and evaporated to dryness. N-butyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine remains.
(c) 8-Benzoyl-N-butyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3'-5,6]pyrido[3,4-3]pyrimidin-5-amine
0.01 mol of N-butyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine and 0.02 mol of benzoyl chloride are stirred overnight in 50 ml of dry pyridine at room temperature. On addition of 50 ml of water, 8-benzoyl-N-butyl-2-methyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine is filtered off.
EXAMPLE 42
N-Butyl-2-methyl-8-(4-methylbenzoyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3'-5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting 1-(4-methylbenzoyl)-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester for the 1-ethyl-4-hydrazino-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, ethyl ester in the procedure of Example 1 a and proceeding as in parts b, c and d, 5-chloro-2-methyl-8-(4-methylbenzoyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine and N-butyl-2-methyl-8-(4-methylbenzoyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine, respectively, are obtained.
EXAMPLE 43
5-(2-Aminoethoxy)-2,6-dimethyl-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting the 5-chloro-2,6-dimethyl-8-ethyl-8H pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine obtained in Example 37 in the procedure of Example 21 and substituting ethanolamine for the 3-(dimethylamino)propanol, 5-(2-aminoethoxy)-2,6-dimethyl-8-ethyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained.
The hydrochloride salt is obtained by treating the above product with ethanolic HCl.
EXAMPLE 44
8-Ethyl-2-methyl-5-[(3-propylamino)propoxy]-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting 3-(propylamino)propanol for the 3-(dimethylamino)propanol in the procedure of Example 21, 8-ethyl-2-methyl-5-[(3-propylamino)propoxy]-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained.
EXAMPLE 45
8-Ethyl-2-methyl-5-(1-piperazinyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting piperazine for the 3-(dimethylamino)propyl-1-amine in the procedure of Example 4, 8-ethyl-2-methyl-5-(1-piperazinyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained.
EXAMPLE 46
N-Butyl-8-ethyl-2,3-diphenyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5-amine
By substituting 3-amino-2,3-diphenylcrotononitrile for the 3-aminocrotononitrile in the procedure of Example 1, 5-chloro-8-ethyl-2,3-diphenyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrazolo[3,4-e]pyrimidine and N-butyl-8-ethyl-2,3-diphenyl-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidin-5amine, respectively, are obtained.
EXAMPLE 47
8-Ethyl-2-methyl-5-thiamorpholino-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting thiamorpholine for the 3-(dimethylamino)propyl-1-amine in the procedure of Example 4, 8-ethyl-2-methyl-5-thiamorpholino-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained.
EXAMPLE 48
8-Ethyl-2-methyl-5-(1-pyrazolyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting pyrazole for the 3-(dimethylamino)propyl-1-amine in the procedure of Example 4, 8-ethyl-2-methyl-5-(1-pyrazolyl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained.
EXAMPLE 49
8-Ethyl-2-methyl-5-pyrrolidino-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting pyrrolidine for the 3-(dimethylamino)propyl-1-amine in the procedure of Example 4, 8-ethyl-2-methyl-5-pyrrolidino-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained.
EXAMPLE 50
8-Ethyl-2-methyl-5-(dihydropyridazin-1-yl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine
By substituting dihydropyridazine for the 3-(dimethylamino)propyl-1-amine in the procedure of Example 4, 8-ethyl-2-methyl-5-(dihydropyridazin-1-yl)-8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[3,4-e]pyrimidine is obtained.
EXAMPLE 51
The following ingredients are used to make 1,000 200 mg tablets each containing 100 mg of active ingredient:
______________________________________N-butyl-8-ethyl-2-methyl-8H-pyrazolo-[1,5-a]pyrazolo[4',3':5,6]pyrido-[3,4-e]pyrimidine-5-amine 100 gm.Polyvinyl pyrrolidone 7.5 gm.Lactose 20 gm.Magnesium stearate 3.5 gm.Corn starch 17.5 gm.Avicel (microcrystalline cellulose) 51.5 gm.______________________________________
The medicament and lactose are thoroughly admixed. The polyvinyl pyrrolidone is dissolved in ethanol USP to make a 30% solution. This solution is used to granulate the mixture of medicament and lactose. The granulation is passed through a No. 16 screen and air dried. The dried granulation is then passed through a No. 20 screen. To the screened granulate are added the magnesium stearate, Avicel and the corn starch and the mixture is blended. The blend is then compressed into 200 mg. tablets on a standard concave punch. The tablets are then veneer coated with methyl cellulose in a spray pan. | New derivatives of 8H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]-pyrido[3,4-e]pyrimidine have the general formula ##STR1## The compounds are useful as anti-inflammatory agents and central nervous system depressants. | 2 |
FIELD OF THE INVENTION
[0001] This invention relates generally to earth-boring drill bits and particularly to improved cutting structures for such bits.
BACKGROUND OF THE INVENTION
[0002] In drilling bore holes in earthen formations by the rotary method, rock bits fitted with one, two, or three rolling cutters are employed. The bit is secured to the lower end of a drill string that is rotated from the surface, or the bit is rotated by downhole motors or turbines. The cutters or cones mounted on the bit roll and slide upon the bottom of the bore hole as the bit is rotated, thereby engaging and disengaging the formation material to be removed. The rolling cutters are provided with cutting elements that are forced to penetrate and gouge the bottom of the borehole by weight of the drill string. The cuttings from the bottom of the borehole are washed away by drilling fluid that is pumped down from the surface through the hollow drill string.
[0003] The earliest rolling cutter, earth boring bits had teeth machined integrally from steel, earth disintegrating cutters. These bits, typically known as “steel tooth” or “milled tooth” bits, are used for penetrating the relatively soft geological formations of the earth. The strength and fracture toughness of steel teeth enables the aggressive gouging and scraping action that is advantageous for rapid penetration of soft formations with low compressive strengths. However the same cutting structure that drills sand formations fast, slows down considerably when it encounters shales. This is due in part to the shale sticking to the bit when it cannot be readily removed by the drilling fluid because of the chisel shape of the teeth and their location on the bit.
[0004] It has been common in the arts since at least the 1930s to provide a layer of wear-resistance metallurgical material called “hardfacing” over those portions of the steel teeth exposed to the severest wear. The hardfacing typically consists of extremely hard particles, such as sintered, cast, or macrocrystalline tungsten carbide dispersed in a steel matrix. Such hardfacing materials are applied by welding a metallic matrix to the surface to be hardfaced and applying the hard particles to the matrix to form a uniform dispersion of hard particle in the matrix.
[0005] Typical milled tooth bits have their teeth milled such that the inner and outer ends and leading and trailing flanks are fairly wide flat surfaces. The flat wide surfaces normal to the direction of rotation increase the tendency for the bit to ball up when sliding in shales. Typical hardfacing deposits are welded over a steel tooth that have a shape similar to the shape of the underlying tooth.
BRIEF SUMMARY OF THE INVENTION
[0006] An earth-boring bit has a bit body and at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body. A cutter is mounted for rotation on each bearing shaft wherein each cutter includes a plurality of hardfaced teeth. At least some of the teeth have a leading side that has a streamlined contour. The leading side has an advance portion that leads inner and outer portions of the leading side. The advance portion has a narrow width compared to the base of the tooth.
[0007] In one embodiment, the streamlined contour is defined by making at least the leading portion of the tooth conical. The apex is rounded, and the trailing flank may be either conical or conventional in shape. Heel row teeth can be streamlined with a conical leading and inner side. The outer or gage side may remain flat.
[0008] In another embodiment, the streamlined contour is defined by providing the leading side with a leading edge. The leading edge is formed by the corner junction of inner and outer diverging sides, which may be flat. Preferably, the included angle of the corner junction is at least 90 degrees.
[0009] Also, at least one inner row may have teeth that incline in opposite directions. Each inclined tooth has a central axis that is inclined relative to an axis of rotation of the cone. Preferably, the inclined teeth alternate with each other, with half of the teeth inclining inward and the other half inclining outward.
[0010] The teeth of the various embodiments have a crest and a base. The crest may be rounded, as in the case of an apex of a conical contour, or it may be flat. Preferably, the crest is narrow compared to the base, having a width that is less than one-third the width of the base.
[0011] In manufacturing, tooth-stubs are machined on the cutter in the desired streamlined configuration. The tooth-stubs have a hardfacing on their surfaces that is a composition of carbide particles dispersed in a metallic matrix. Each tooth-stub and the hardfacing define one of the cutting elements of the cutter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a perspective view of an earth-boring bit of the steel tooth type constructed in accordance with this invention.
[0013] [0013]FIG. 2 is an enlarged perspective view of a heel row tooth of the earth-boring bit shown in FIG. 1.
[0014] [0014]FIG. 3 is a cross sectional view, taken along the line 3 - 3 of FIG. 2, of the heel row tooth illustrated in FIG. 2.
[0015] [0015]FIG. 4 is an enlarged perspective view of an inner row tooth of the earth-boring bit shown in FIG. 1.
[0016] [0016]FIG. 5 is a cross sectional view, taken along the line 5 - 5 of FIG. 4, of the inner row tooth illustrated in FIG. 4.
[0017] [0017]FIG. 6 is a front elevational view of an alternate embodiment of a tooth for the earth-boring bit shown in FIG. 1, the tooth being a three-sided pyramid in configuration.
[0018] [0018]FIG. 7 is a top plan view of the tooth of FIG. 6.
[0019] [0019]FIG. 8 is a front elevational view of another alternate embodiment of a tooth for the earth boring bit of FIG. 1, the tooth being a four-sided pyramid in configuration.
[0020] [0020]FIG. 9 is a top plan view of the tooth of FIG. 8.
[0021] [0021]FIG. 10 is a front elevation view of another alternate embodiment of a tooth for the earth boring bit of FIG. 1, the tooth having a leading side that is conical.
[0022] [0022]FIG. 11 is a top plan view of the tooth of FIG. 10.
[0023] [0023]FIG. 12 is a schematic view of an alternate embodiment of an inner row of teeth for the earth boring bit of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] Referring to FIG. 1, an earth-boring bit 11 according to the present invention is illustrated. Bit 11 includes a bit body 13 having threads 15 at its upper extent for connecting bit 11 into a drill string (not shown). Each leg of bit 11 is provided with a lubricant compensator 17 . At least one nozzle 19 is provided in bit body 13 for directing pressurized drilling fluid from within the drill string to cool and lubricate bit 11 during drilling operations. At least one cutter 21 is rotatably secured to a leg of bit body 13 . Typically, each bit 11 has three cutters 21 , two of which are shown in FIG. 1 and another that is obscured from view in FIG. 1.
[0025] Each cutter 21 has a shell surface including a gage surface 25 . Heel row teeth 29 are the outermost teeth and are located at the junction of the conical surface of cutter 21 and gage surface 25 . As shown in FIGS. 2 and 3, each heel row tooth 29 has an underlying support member 31 , or tooth-stub, that is machined from the conical surface of cutter 21 . A layer of hardfacing material 33 is welded over tooth-stub 31 . Hardfacing 33 typically consists of extremely hard particles, such as sintered, cast, or macrocrystalline tungsten carbide, dispersed in a steel matrix. Hardfacing materials 33 are typically applied by welding a metallic matrix to the surface to be hardfaced and applying the hard particles to the matrix to form a uniform dispersion of hard particle in the matrix. Each heel row tooth-stub 31 has an outer end 35 that is substantially flat and flush with gage surface 25 . Hardfacing 33 is applied to outer end 35 so that gage surface 25 is substantially continuous up the outer end of heel row tooth 29 , as illustrated in FIG. 1.
[0026] In the embodiment shown in FIGS. 2 and 3, at least the leading portion of each heel row tooth 29 is shaped to be streamlined. The term “streamline” herein means a contour of a tooth constructed so as to offer minimum resistance to material flow. The leading side of the tooth is designed to provide less resistance than in the prior art to the flow of sticky shale and mud around the tooth as the tooth rotates and slides through the shale. The leading side is configured so that the flow vectors of the shale and mud do not make sharp turns as they pass the tooth. Generally that means that there will be little, if any, portion of the leading side that is flat and normal to the direction of rotation of the cutter. Preferably, all surfaces having any significant width on the leading side are at least 45° from a position facing into the direction of rotation.
[0027] In the embodiment of FIGS. 2 and 3, heel row tooth 29 is generally conical except for the flat outer end 35 . Rather than being elongated, the crest or apex 36 is rounded and dome-shaped. The leading and trailing flanks and the inner end, referenced as inner portion 37 , are rounded into the shape of a cone. Inner portion 37 forms a heel row tooth 29 that is thus partially conical in shape. The width or diameter of apex 36 is measured at the point of curvature from the sloping sides. The width or diameter of the base of tooth 29 is measured at the point where tooth 29 joins the supporting metal of cone 21 , and it is measured from outer end 35 to the inner portion 37 . The width of apex 36 is preferably less than one-third the width of the base.
[0028] The underlying support metal or tooth-stub 31 is formed in this partially conical shape. Hardfacing 33 is applied over tooth-stub 31 , typically, in a generally uniform thickness. The leading side of conical inner portion 37 has no flat areas that might impede the flow of viscous shale and drilling mud.
[0029] Referring again to FIG. 1, a plurality of inner row teeth 39 are formed on each cutter 21 radially inward from heel row teeth 29 up to the apex of cutter 21 . One of cutters 21 typically has a spear point (not shown) on its apex, another an inner row of teeth 39 (not shown) near its apex, and the third has a conical apex free of inner row teeth 39 . Each cutter 21 will have one or more rows of inner row teeth 39 .
[0030] Referring to FIGS. 4 and 5, at least some of the inner row teeth 39 have an underlying support metal or tooth-stub 41 that has a leading side with a streamlined configuration. Tooth-stub 41 is machined from the metal of cutters 21 and may have different shapes. In this embodiment, tooth-stub 41 is conical with a rounded apex 43 . The width of apex 43 is less than one-third the width of the base of tooth-stub 41 . A uniform hardfacing layer 45 is applied over tooth-stub 41 . The exterior of inner row tooth 39 , being conical, does not have any flat areas normal to the direction of rotation.
[0031] Referring to FIG. 6, tooth 47 is another embodiment of an inner row tooth. Tooth 47 has a configuration of a three-sided pyramid. Tooth 47 has a base 48 that is triangular, as shown in FIG. 7. Three sides 49 , 51 and 53 , each being triangular, lead to an apex 55 . Although apex 55 is shown as sharp, it could be truncated and rounded. If truncated or rounded, preferably the width of apex 55 will be less than one-third the width of base 48 of tooth 47 . Sides 49 and 51 form the leading side of tooth 47 , while side 53 trails, considering the direction of rotation or sliding indicated by the arrow. Sides 49 , 51 are outer and inner portions, respectively, of the leading side. Sides 49 , 51 intersect each other at an advance portion, the advance portion being a portion of tooth 47 that leads the remaining portions of tooth 47 . This advance portion comprises a leading edge or corner 57 defined by the intersection of outer and inner sides 49 , 51 . Corner 57 is fairly sharp, thus has a width much smaller than the width of tooth 47 . Outer and inner sides 49 , 51 are shown to be flat, but they could be curved, either concave or convex. The included angle 59 of corner junction 57 is preferably less than 90°, and in this embodiment it is 60°. Consequently, outer and inner sides 49 , 51 are oriented 60° from the direction of rotation. Tooth 47 is hardfaced as in the other embodiments.
[0032] Referring to FIGS. 8 and 9, tooth 61 is another embodiment of an inner row tooth that has the shape of a pyramid. Tooth 61 has a rectangular base 62 and four sides 63 , 65 , 67 and 69 . Sides 63 , 65 are on the leading side of tooth 61 considering the direction of rotation. Sides 67 , 69 are on the trailing sides. Sides 63 , 65 , 67 , 69 join each other at an apex 70 . Apex 70 could be rounded or truncated rather than sharp as shown. Also, its width will be less than one-third the width of base 62 if truncated or rounded.
[0033] Sides 63 , 65 are the inner and outer portions, respectively, of the leading side of tooth 61 . Sides 63 , 65 join each other at a corner junction 71 . Corner junction 71 is the advance portion of tooth 61 because it leads all the remaining portions. Corner 71 is defined by the intersection of the diverging inner and outer sides 63 , 65 . In this embodiment the included angle 73 of corner junction 71 is 90°. Consequently, each inner and outer side 63 , 65 is oriented 45° relative to the direction of rotation. Outer and inner sides 63 , 65 , although shown to be flat, could be concave or convex to some extent. The width of corner 71 is very small compared to the width of base 62 from corner to the other corner.
[0034] In the embodiment of FIGS. 10 and 11, tooth 75 has a leading side 77 that is conical and a trailing side 79 that is a generally flat flank. The conical leading side 77 joins an outer side 81 and an inner side 83 , both of which are flat and parallel to the direction of rotation. The conical contour of leading side 77 is truncated, defining a flat crest 85 . Crest 85 preferably has a width that is less than one-third the width of the base of tooth 77 . The advance portion of leading side 77 is a center line 87 of conical leading side 77 that extends from the base to crest 85 . Preferably, leading side 77 extends a full 180° to junctions 89 with sides 81 and 83 . The angle 91 between advance center line 87 and each junction line 89 is 45°. Tooth 75 is also hardfaced in the same manner as the other embodiments.
[0035] [0035]FIG. 12 illustrates an inward inclined tooth 93 that is in an alternate embodiment row to one of the inner rows shown in FIG. 1. Inward inclined tooth 93 has a central axis 95 that extends from its base to its apex. Axis 95 is located equidistant between an inner side 94 and outer side 96 of tooth 93 . Axis 95 is inclined or skewed relative to an axis of rotation rather than being in a plane perpendicular as in the prior art. Axis 95 inclines inward, and the row contains a number of similar inward inclined teeth 93 .
[0036] The same row contains a number of outward inclined teeth 97 . Each outward inclined tooth 97 has a central axis 99 that inclines also, but in an opposite direction from axis 95 . Each axis 99 is located equidistant between the inner and outer sides of outward inclined tooth 97 . The amount of inclination relative to a line that is perpendicular to the rotational axis may vary.
[0037] Preferably, each inward inclined tooth 93 alternates with one of the outward inclined teeth 97 . This results in a clearance between teeth 93 , 97 that is parallel to the direction of rotation to facilitate the flow of sticky shales through teeth 93 , 97 of the row. Teeth 93 , 97 are shown schematically, and could be conventional. Alternately, they could have streamlined contours, similar to any of the embodiments above. Although teeth 93 , 97 are shown schematically to have a base and a crest that are about the same width, the crest could be much smaller than the width of the base. As in the other embodiments, the crest could have a width less than one-third the width of the base of each tooth 93 and 97 .
[0038] The invention has significant advantages. Streamlined teeth as described facilitate better cuttings removal while maintaining an aggressive cutting structure. The particular shape for the teeth can vary depending on each drilling application. Not all of the inner teeth need to be the same shape. The shape of the heel row teeth can differ as well. Shapes other than conical or pyramidal are feasible.
[0039] While the invention has been shown in only a few of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention. | An earth-boring bit has a bit body, at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body, and a cutter mounted for rotation on the bearing shaft. The cutter includes a plurality of teeth that are covered with a hardfacing layer. At least some of the teeth have a leading side that has a streamlined contour. The streamlined contour is generally conical in some of the embodiments. In others, the streamlined contour is defined by a corner between diverging inner and outer sections of the leading side. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an improved construction of filtration media of a wedge filter providing a performance on both surface and inner filtration mechanisms with offering many times recycled use by washable functions. Particularly a wedge filter plate is used to construct a hollow cylindrical type media of wedge filter. The whole construction of a wedge filter plate of the present invention is a flat plate with a web pattern manufactured by several different radius wedge-shaped strings of concentrically circular arc and several radial struts. The radial sedimentation chambers are established between each adjacent different radius wedge-shaped string. The sectional view of a wedge-shaped string is wedge or triangle. The thickness of a wedge-shaped string is less than a radial strut of the wedge filter plate. When wedge filter plates are laminated so as to construct a hollow cylinder, the differences of thickness become wedge-shaped apertures between each adjacent plate, and these filtering apertures of circular arc constitute a plurality of concentrically cylindrical filter screens with different radius. The sedimentation chambers are between each adjacent filter screen whereby to separate each filter screen. The mesh size of filter screen can increase progressively either from inner filter screen to outer filter screen or from outer filter screen to inner filer screen. The particles of different size are classified according to filter screens of different mesh size and left in the sedimentation chambers to accumulate filter cakes, which approaches the performance of applying a series of filter screen with different mesh size. When filter cakes accumulate excessively, it only needs to take the filtration media out, loosen the nuts at the ends of rod, and wash each individual filter plate completely. When all done, reassemble and tighten all elements up, then the filtration media can be reused.
[0002] 1. Technical Field of the Invention
[0003] The present invention focus its efforts on developing an improved construction of filtration medium of a wedge filter, which particularly focus on a wedge filter plate which is used to construct a hollowly cylindrical filtration medium. The construction of the wedge filter plate is manufactured by several concentrically wedge-shaped strings of different radius that constitute concentrically multi-layered filter screens to classify the particles of different size, then deposit them in sedimentation chambers established between each adjacent filter screen and form filter cakes in order to promote the efficiency of water treatment greatly.
[0004] 2. Prior Art Technique
[0005] Currently, the wedge filter is popular used in industrial fluid filter system and residential drinking waster filter system, especially a use of a device for pre-filtration to remove large particles, and the wedge filter is used widely in a need for only removing particles that are above 10s μm. The reason of the wedge filter is used widely substantially in many field is its virtues of the filter surface of easy wash, large volumes of outflow, and low filtration pressure.
[0006] FIG. 1 shown a wedge filtration media ( 01 ) of a filter is manufactured by winding a stainless steel wedge wire ( 02 ) in an equal interval pitch into a spiral cylinder of same radius, and there are several axial stainless steel struts ( 03 ) inside the cylinder to fix the stainless wire ( 02 ) by welding to enhance the wedge filtration media ( 01 ) strength to withstand high operation pressure during the filtration process. The mesh size of a wedge filtration media ( 01 ) is determined in course of production and based on the axial pitch between each adjacent wire, in other word, the aperture between each adjacent wire is the size of the mesh, and the minimum size is 0.025 mm. It costs expensive to make a wedge filtration media ( 01 ) because the production process is very precise. The wedge filtration media ( 01 ) adopts surface filter system that causes filter cakes to easily accumulate on the filter surfaces, which increases the filtration pressure and decreases the filtered outflow volume. Therefore, a periodical removal of filter cakes becomes an important job for the wedge filtration media ( 01 ), for this reason, the inventions of a wedge filtration media always focus on how to reduce the growth of filter cakes in order to lengthen the periodicity of re-washing. Two of most popular methods for washing the wedge filtration media ( 01 ) are hand washing and mechanical cleaning. The wedge filtration media ( 01 ) with small mesh needs a high pressure water flow or high pressure air to spray washing on reverse side by hand, but for industrial purpose of large volume of flow and continuous filtration usually employ the cleaning mechanism, such as:
1. A use of parallel filtration mechanism to reduce filter cakes growth, U.S. Pat. No. 4,311,591. 2. A use of a self-cleaning brush mechanism to remove filter cakes, U.S. Pat. No. 6,861,004 B2. 3. A use of rotational bar to shake the filtration media continuously to reduce filter cakes growth, JP9024216. 4. A device of synchronous reverse washing for the filtration media cylindrical surface.
[0011] Since the mesh size of the wedge filtration media ( 01 ) is uniform, thus the tempo and the thickness of filter cakes accumulation become important factors in affecting the filtration efficiency. The cleaning methods described above are rarely employed for residential purpose or other medium and small size filter system because of the facilities cost and the filtered flow volume.
[0012] Besides the methods described above, increasing the filtering surface is also a popular method, such as:
1. A use of a series of wedge filters with different mesh size to lengthen the periodicity of washing and promote the efficiency of filter system. 2. A use of concentric C-shaped wedge filtration media, US2006/0201873 A1.
[0015] From prior art technique described above, there are some solutions were addressed successively for the wedge filter, but for residential purpose of medium and small size still has some issues needed improvement as the following:
1. A wedge filtration media is manufactured by winding a stainless steel wedge wire and formed by welding, the process of production is high precise and costs expensive. 2. The surface filter system of uniform mesh size causes filter cakes easily formed and increasing filtration pressure needed. Therefore, applying a series of wedge filters of different mesh size becomes a necessary method for lengthening the periodicity of washing. 3. A wedge filtration media of small mesh has a need of applying reverse high pressure water flow or high pressure air to spray washing on reverse side or use a small brush to clean.
[0019] The reason of a conventional wedge filter till popular now is its virtues of strength, large volume of flow, and reusability. The present invention not only retains these previous advantages, but also has developed several innovative virtues, such as easy production, low cost, series filtration mechanism to reduce filter cakes growth and easy to wash, so that the wedge filter of the present invention will be helpful for end user and more widely application.
SUMMARY OF THE INVENTION
[0020] According to the issues of prior art technique described above, the present invention has developed an innovative design to improve construction of a wedge filtration media as the following:
[0021] The present invention addressed an improved construction of a wedge filtration media that improve not only with surface but also inner filtration mechanism, and washable function, more particularly, a wedge filter plate which used to construct a hollowly cylindrical wedge filtration media. The construction of the wedge filter plate of the present invention is a flat plate with a web pattern manufactured by several different radius wedge-shaped strings of concentrically circular arc and several radial struts.
[0022] Another object of the present invention is to provide an improved construction of a wedge filtration media which is simple construction, easy production, low cost and high strength in order to be applied under high operation pressure.
[0023] A more object of the present invention is to provide such an improved construction of a wedge filtration media which can easily dismantle the wedge filtration media to separate each wedge filter plate completely and apply a simple method to clean.
[0024] A more object of the present invention is to provide such an improved construction of a wedge filtration media with back washable function, which doesn't need to dismantle the wedge filtration media but just open a drain valve at the bottom of the filter casing with suitable pipe connected when backwash is needed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 illustrates a prior art technique for manufacturing a wedge filtration media.
[0026] FIG. 2 illustrates a sectional view of a construction of a wedge filter plate of the present invention.
[0027] FIG. 3 is an enlarged view of filtration mechanism of the filter system of the present invention
[0028] FIG. 4 is a construction view of the wedge filtration media of the present invention
[0029] FIG. 5 is a view of disassembled process of the wedge filtration media of the present invention.
[0030] FIG. 6 is a practical example for the applying use of the wedge filter of the present invention
DETAILED DESCRIPTION OF THE INVENTION
[0031] The present invention provides an innovative design for an improved construction of a wedge filtration media wherein the wedge filter plate is manufactured as a web pattern by several strings of concentrically circular arc radiating outward from the hollow, and comprising several different radius wedge-shaped strings of concentrically circular arc, several radial struts, a hollow at central part, and radial sedimentation chambers between each adjacent different radius wedge-shaped string. When wedge filter plates are overlapping, the spaces between each adjacent wedge filter plate become the apertures that perform the filter function. The characters are disclosed in detail below:
[0032] There are several different radius wedge-shaped strings of circular arc, and a sectional view of a string is wedge or triangle, the long-axis X and the short-axis Y of the section are perpendicular to each other, the long-axis X of the section is perpendicular to the central line of the hollow and presents the length of the section, the short-axis Y of the section is parallel to the central line of the hollow and presents the thickness of the section. Every different radius wedge-shaped string has different thickness and is thinner than a wedge filter plate. A radial strut has same thickness as a wedge filter plate. When wedge filter plates are overlapping, the difference of the thickness between a wedge-shaped string and a wedge filter plate becomes the filtering aperture between each adjacent wedge filter plate, and the sizes of the filtering apertures are the sizes of the meshes of the wedge filtration media. The aperture resulting from wedge filter plates overlapping is formed from the lower side of an upper wedge-shaped string and the upper side of a lower wedge-shaped string and has a narrow throat for entrance and a wide opening for exit. There are several different radius filtering apertures of circular arc constitute a series of concentrically cylindrical filter screens of different radius inside the wedge filtration media. The radial sedimentation chambers are established between each adjacent different radius wedge-shaped string, so that the sedimentation chambers link the apertures together and make combinations in series, and creating several series of filter systems of different mesh size from the outer to the inner, therefore the particles larger than the apertures will be captured and left in the sedimentation chambers. The hollow is located in the center of a wedge filter plate and provides a passageway for a fluid flow when wedge filter plates are overlapping.
EMBODIMENT OF THE INVENTION
[0033] As illustrated as the following description to further explain the features, purpose and function of the present invention:
[0034] FIG. 2 is a detail of the construction of a wedge filter plate ( 1 ) of the present invention. The construction of a wedge filter plate ( 1 ) is manufactured by several different radius wedge-shaped strings ( 10 ) of concentrically circular arc and several radial struts ( 14 ), at central part has a hollow ( 33 ), and radial sedimentation chambers ( 34 ) between each adjacent different radius wedge-shaped string, therefore, the wedge filter plate ( 1 ) is manufactured as a porous web pattern by wedge-shaped strings of concentrically circular arc radiating outward from the hollow. A sectional view of a wedge-shaped string ( 10 ) is wedge or triangle, the long-axis (X) of the section points to the hollow ( 33 ), the short-axis (Y) of the section is parallel to the central line of the hollow ( 33 ). Every wedge-shaped string ( 10 ) has different thickness (t 2 ). A radial struts ( 14 ) has same thickness (t 1 ) as a wedge filter plate ( 1 ). There is a difference (t 3 ) between a wedge-shaped string and a wedge filter plate ( 1 ). The outermost wedge-shaped string ( 11 ) has least thickness, the innermost wedge-shaped string ( 12 ) has most thickness, and every wedge-shaped string ( 10 ) is thinner than a wedge filter plate ( 1 ).
[0035] As illustrated in FIG. 2 and FIG. 3 in the present invention, when several wedge filter plates ( 1 ) are overlapping, the wedge-shaped filtering apertures ( 31 ) between each adjacent wedge filter plate ( 1 ) result from the differences (t 3 ) of thickness and are the sizes of the filter meshes. These wedge-shaped filtering apertures ( 31 ) resulting from the differences (t 3 ) of wedge-shaped strings of concentrically circular arc ( 10 ) constitute a plurality of concentrically cylindrical wedge filter screens. While two adjacent wedge filter plates are overlapping, the lower side ( 112 ) of the upper wedge-shaped string and the upper side ( 111 ) of the lower wedge-shaped string become the upper side and the lower side of the wedge-shaped aperture. The narrow throat ( 320 ) of the wedge-shaped aperture has the smallest space, and the wide opening ( 319 ) of the wedge-shaped aperture has the biggest space. The wide opening ( 319 ) faces inwardly the hollow ( 33 ). The outermost wedge-shaped string ( 11 ) has most difference (t 3 ), so its filtering aperture throat ( 317 ) is the biggest; the innermost wedge-shaped string ( 12 ) has least difference (t 3 ), so its filtering aperture throat ( 318 ) is the smallest, and the minimum size of a filtering aperture is 0.025 mm.
[0036] As shown in FIG. 3 in the present invention, the arrow ( 312 ) indicates the direction of an unfiltered fluid flow contains particles entering from the inlet of enclosure. The big particles ( 51 ) larger than the filtering aperture ( 317 ) are separated by the filtering aperture ( 317 ) that is established by the outermost wedge-shaped string ( 11 ) and deposited on the exterior surface of the filtration media ( 22 ). Smaller particle ( 50 ) has passed through the filtering aperture ( 317 ) will continually flow to the hollow ( 33 ) of the wedge filtration media according to the direction of arrow ( 311 ). After being classified by multi-layered filtering apertures ( 31 ), the extremely small particles ( 52 ) will pass through the smallest filtering aperture ( 318 ) and arrive at the hollow ( 33 ) of the wedge filtration media, then flow out according to the direction of arrow ( 314 ). A large percentage of particles ( 50 ) are captured because their sizes are larger than one of the filtering apertures ( 31 ) and left in sedimentation chambers ( 34 ). When more and more particles ( 50 ) are deposited in sedimentation chambers ( 34 ), filter cakes are gradually growing and accumulating, and a need for filtration pressure is increasing too. When sedimentation chambers are full of filter cakes, only to wash the wedge filtration media ( 22 ), then can reuse it. This filter system approaches the performance as same as applying a series of wedge filters of different mesh size, that ensures the outflow volume will not decrease deeply during a period because of particles blocking up and the filtration pressure will not increase rapidly also.
[0037] FIG. 4 is a part cross section view of a wedge filtration media ( 22 ) of the present invention, which is constructed from laminated wedge filter plates ( 1 ). The wedge filtration media ( 22 ) shown in FIG. 4 comprises a fixed round plate ( 231 ) at the top, a fixed round plate ( 232 ) at the bottom, and a hollow cylinder ( 21 ) between them constructed from laminated several wedge filter plates ( 1 ) of certain length. There is a fixed rod ( 24 ) at the hollow ( 33 ) of the hollow cylinder ( 21 ). The both ends of rod ( 24 ) pass through a top fixed round plate ( 231 ) and a bottom fixed round plate ( 232 ), and each end has a tightened nut ( 241 ) and ( 242 ) to tighten up all elements of the wedge filtration media ( 22 ). At central part of a top fixed round plate ( 231 ) has a concave opening ( 331 ) where is an exit of the wedge filtration media ( 22 ) to combine with the downward elongation ( 64 ) of an exit at a top cap ( 65 ) of the wedge filter ( 60 ), shown on FIG. 6 . The bottom fixed round plate ( 232 ) can completely isolated an unfiltered fluid flow from entering the hollow ( 33 ) of the wedge filtration media ( 22 ).
[0038] FIG. 5 illustrates one of cleaning processes of a wedge filtration media ( 22 ) of the present invention. First, taking the wedge filtration media ( 22 ) out from the wedge filter ( 60 ), then loosing the tightened nuts ( 241 ) and ( 242 ) at the both fixed round plates ( 231 ) and ( 232 ) at ends of rod ( 24 ), so that all elements of the wedge filtration media ( 22 ) are dismantled, each wedge filter plate ( 1 ) is completely separated piece by piece, and particles ( 50 ) are easy to be removed from sedimentation chambers ( 34 ).
[0039] In FIG. 6 , showing a wedge filtration media ( 22 ) of the present invention is installed inside a wedge filter ( 60 ). There is a hollowly cylindrical wedge filtration media ( 22 ) is constructed from laminated wedge filter plates ( 1 ). A top cap ( 65 ) of the wedge filter ( 60 ) has an inlet ( 61 ) and an outlet ( 62 ) with the downward elongation ( 64 ) which connected with an exit of the wedge filtration media ( 22 ). The threads ( 73 ) of casing ( 71 ) of the wedge filter ( 60 ) hooks up with the threads ( 63 ) of the top cap ( 65 ). The wedge filtration media ( 22 ) is installed in and fixed at the bottom ( 75 ) of the casing ( 71 ). The fluid flow moves forward according to the direction of arrow ( 315 ).
[0040] The wedge filtration media of the present invention has several features as the following:
1. The wedge filter plate is formed by a model directly, so the cost is low. When wedge filter plates are laminated and construct a hollowly cylindrical wedge filtration media, the strength of construction has been largely enhanced and able to bear high operation pressure. 2. There are several cylindrical filter screens and sedimentation chambers established by several series wedge-shaped strings of concentrically circular arc, which perform a result that employ a series of multi-layered filter screens from the exterior to the interior and increase the filter efficiency. The mesh size of the filter screen increases progressively from inner filter screen to outer filter screen to classify particles of different size, so that a wide range distribution of filter cakes within the wedge filtration media from the exterior to the interior to lengthen the periodicity of filtration and maintain low filtration pressure. 3. When the filter cakes need to be removed, only loosen the nuts which fixed at the ends of rod, separate and wash each wedge filter plate piece by piece completely, that will not have a washing dead space and don't need a high pressure water flow or a high pressure air to wash.
[0044] Conclusion of above descriptions, the present invention obviously possesses the above efficiencies and practical values, and can promote the benefit of economic values, so the present invention is an excellent innovation indeed. There is no same or similar product in this technical field has been used in public, so the present invention is qualified for a claim for applying the patent. The above descriptions just only are one of practical examples of the present invention that could not be a limit to the filed in the present invention. Whatever an adaptation, an alternation or a modification as long as bases on the patent field of the present invention and still retains the essence of the present invention or not beyond the spirit and the field of the present invention substantially should be viewed as the further practical situation of the present invention.
[0000]
DESCRIPTION OF THE SYMBOLS FOR THE ELEMENTS IN THE
DRAWING
01
A Wedge Filtration Medium
50
Particles
02
A Stainless Steel
51
The Biggest Particles On
Wedge-Shaped
Out Surface of The
Wire
Filtration Medium
03
Axial Stainless Steel Struts
52
The Extremely Small
Particles In The Hollow
of A Filtration media
1
A Wedge Filter Plate
60
A Wedge Filter
10
The Wedge-Shaped String
61
Inlet Of A Wedge Filter
11
The Outermost
62
Outlet Of A Wedge Filter
Wedge-Shaped String
111
The Upper Side Of The
63
The Threads OF A Top Cap
Sectional View Of A
Of A Wedge Filter
Wedge-Shaped Aperture
112
The Low Side Of The
64
The Downward Elongation
Sectional View Of A
Of Outlet At Top Cap Of A
Wedge-Shaped Aperture
Wedge Filter
12
The Innermost
71
A Wedge Filter Casing
Wedge-Shaped String
14
The Radial Struts
73
The Opening Threads OF
A Wedge Filter Casing
21
A Hollow Cylinder By
75
The Bottom Of A Wedge
Laminated Wedge Filter
Filter Casing
Plates
22
A Filtration Medium By
t1
The Thickness Of A Wedge
Laminated Wedge Filter
Filter Plate Same As
Plates
Radial Struts Thickness
231
A Fixed Round Plate At The
t2
The Thickness Of A
Top
Wedge-Shaped String
232
A Fixed Round Plate At The
t3
The Differential Thickness
Bottom
Between Radial Struts and
Wedge-Shaped String
24
A Fixed Screw Rod
X
The X-Axis Of The Section
Of A Wedge-Shaped String
Is Orthogonal To The
Central Line
241
A Tightened Nut
Y
The Y-Axis Of The Section
Of A Wedge-Shaped String
Is Parallel To The Central
Line
242
A Tightened Nut
31
The Wedge-Shaped
Apertures
311
The Direction Of A Fluid Flow
312
The Direction Of A Fluid Flow
314
The Direction Of A Fluid Flow
315
The Direction Of A Fluid Flow
317
The Outermost
Wedge-Shaped Filtering
Aperture
318
The Innermost
Wedge-Shaped Filtering
Aperture
319
A Wide Opening Of A
Wedge-Shaped Filtering
Aperture
320
A Narrow Throat Of A
Wedge-Shaped Filtering
Aperture
33
The Central Hollow of A
Wedge Filter Plate
331
The Opening of A Top Fixed
Round Plate
34
The Sedimentation Chambers
Between Two Wedge-Shaped
Strings | An improved construction of filtration media of a wedge filter provides a performance on both surface and inner filtration mechanisms with offering many times recycled use by washable functions. Particularly a wedge filter plate is used to construct a hollow cylindrical type media of wedge filter. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to decorticated and fibrillated bast fibers as reinforcement for polymeric, thermoplastic, and thermoset composites.
[0003] 2. Description of the Related Art
[0004] A polymer matrix composite (PMC) is defined as a matrix of plastic resins reinforced by fibers or other reinforcements with a discernible aspect ratio of length to diameter. Materials used to reinforce resins to provide superior strength, stiffness, impact resistance relative to weight include primarily glass, carbon, boron, aramids and cellulosic, or organic fibers. The fibrous reinforcements with a relatively high aspect ratios are distinctly different from fillers which are primarily in particulate or powdered form. Fillers for plastics include calcium carbonate, talc, mica, wollastonite, fly ash and other inorganic or organic compounds. The polymers may be either thermoset or thermoplastic resins and include polyesters, vinyl esters, epoxies, polyvinylchloride (PVC) and polyolefins such as polypropylene (PP) and low/medium/ high density polyethylene (LDPE, MDPE, HDPE).
[0005] The superior properties of the reinforced plastics makes them particularly useful for load bearing and structural applications. Polyolefins currently account for approximately 11.92 billion pounds of material, over 51% of the potential market. The total global annual consumption of reinforced plastics surpassed 23 billion pounds in 1999, and continues to grow at an overall rate of 5.4% per year. While both continuous and short fibers are used as reinforcement, a particular need is evident for the use of short lignocellulosic bast fibers such as flax, kenaf, jute, ramie, sisal, and hemp.
[0006] Natural bast fibers such as hemp, jute, flax, kenaf and sisal, have been used for tens of thousands of years to make paper, textiles, cordage and other products essential to human existence. Recently, there has been a resurgent interest in utilizing agricultural products as feedstock for industrial application. This trend is driven by several key factors, among them: 1) Reduction of dependence upon forest products and foreign petroleum; 2) Need to find alternatives to farm subsidies to support rural communities; 3) Elimination of air pollution caused by burning waste straw; 4) Desire to utilize more sustainable, less toxic natural resources.
[0007] In 1996, German environmental legislation mandated that cars must be able to be recycled. While the European automobile manufacturers found that they could successfully recover and recycle steel and rubber materials, they could do little with the glass fiber reinforced plastics used throughout vehicle interiors.
[0008] By combining natural fibers with polypropylene fibers in to non-woven mat products, then heating and pressing these mats into three-dimensional shapes, manufacturers could effectively produce interior trim components such as door panels, seat backs, package trays and instrument panels. Automobile manufacturers found that these natural fiber composites achieved a number of important benefits, including improved impact strength, significant weight reduction, lower manufacturing costs, greater dimensional stability, better acoustical performance, reduced waste generation, ability to recycle products, and safer work environments.
[0009] Flax ( Linum usitatissimum L.) is grown as a commercial crop in Canada and the U.S. and harvested primarily for oil seed. Flax oil yields high quality solvents and lubricants such as linseed oil, and building materials such as linoleum flooring. Once harvested, the flax stalk becomes waste field straw. Because this straw cannot typically be plowed under, it poses a significant waste management problem for growers. The traditional disposal method is to burn it in the field, but this practice generates significant environmental and human health problems. Every 100,000 acres of flax straw burned produces the equivalent annual emissions of approximately 43,000 cars, or over 2 million pounds of green house gasses.
[0010] The traditional process for preparing the straw for reinforcement involves decortication. During decortication, the ‘shive’ core from the plant is removed and the fibers from the ‘bark’ of the plant is extracted. These long fibers, typically 4 to 6 inches in length are then used to prepare a non-woven, or needle punched mat with other polymeric fibers for use in compression molded parts.
[0011] For many years there has been a significant effort in research laboratories in North America, Europe and Asia to develop process technologies to effectively exploit the reinforcement properties of bast fibers in plastics. While a number of technologies have worked on a laboratory scale, the only commercial application of bast fibers has been in non-woven mats in compression molded automotive parts as described above. Since compression molding constitutes only about 20% of the installed base, the focus of research efforts has been to develop other methods to address a much larger market sector.
[0012] Every attempt in the past has resulted in problems similar to that quoted in U.S. Pat. No. 6,114,416 where the bast decorticated fiber due to its low bulk density ‘balls up’. Other terms used to describe the phenomenon is ‘clumping’, ‘matting’ or ‘hanging together’ of the fibers during compounding. The result of this has been an uneven and inconsistent distribution of the fiber in the resin matrix in the final product with areas that are resin rich and those that resin starved (fiber rich). Also, the surface finish of the parts is not smooth due to the effect of ‘clumping. Additionally, as reported in U.S. Pat. No. 6,114,416, the percent of bast fiber by weight that may be added to the resin is also very limited, typically much less than 10% by weight beyond which compounding, and molding of the composite specimen is not possible.
[0013] A prior method of fibrillation of bast fibers includes steam explosion. The STEX (steam explosion) process uses hydrolysis at elevated temperatures as its main method of removing unwanted constituents of flax, especially pectins, hemicellulose, and lignin. The processes described in the technical literature generally soak the flax with aqueous solutions prior to steam explosion. The thoroughly wet flax has adherent water, the acidity of which has been adjusted to the alkaline side in an attempt to reduce the degradation of the cellulose. A typical successful STEX process exposes the flax to 200 C. temperatures for 10 to 20 minutes. After quick release of the pressure, the steam-exploded flax usually is washed with an alkaline solution.
[0014] The effect of this procedure leads to a product that is high in cellulose percentage because most of the other polymers have been removed. Nevertheless, the composition of the cellulose has changed due to partial hydrolysis of this glucose polymer. The key indication of this damage is the degree of polymerization (DP) of the cellulose. Flax cellulose has DP of 1000 to 2000 glucose units. The reduction in DP depends on the severity of the conditions under which the STEX takes place. If the severity exceeds 3.0, the degradation is so drastic that the product is worthless. The most sophisticated STEX processes have a severity of about 2.7 which still provides a strong, useful product. Nevertheless, about 20% to 50% of the DP will be lost to associated hydrolytic action.
SUMMARY OF THE INVENTION
[0015] Through a combination of special processes, decorticated bast fibers are converted to a unique fibrillated state of matter, herein termed Fibex (FIBEX™), that overcomes all the difficulties in the stated above during compounding and molding. Fibex fibrillated bast fibers, also have superior characteristics over prior bast fibers.
[0016] While waste flax straw has been used as for demonstration of the invention, the general methodology covers all bast fiber materials listed above including flax, hemp, kenaf, jute, sisal, ramie, and similar bast fibers and lignocellulosic fibers. FIG. 1 shows the relative strengths of various pure bast fibers. As shown, flax is one of the strongest of the natural fibers.
[0017] The invention, in one form, comprises a fibrillated bast fiber composition including a decorticated bast fibers of which at least approximately 90% of the fibers have a cross-sectional area of less than approximately 700 micrometers squared.
[0018] The invention, in another, comprises form a fibrillated bast fiber composition including decorticated bast fibers which have been fibrillated without auto-hydrolysis, such that the fibrillated fibers have a molecular weight at least 75% of the molecular weight of the pre-fibrillated decorticated fibers.
[0019] The invention, in yet another form, comprises a fibrillated bast fiber composition including decorticated bast fibers which have been fibrillated without auto-hydrolysis such that the fibrillated fibers have a molecular weight at least 90% of the molecular weight of the pre-fibrillated decorticated fibers.
[0020] The invention, in still another form, is a process of forming a bast fiber composition comprising providing decorticated bast fibers; fibrillating the decorticated bast fibers utilizing mechanical impact; and admixing the fibrillated bast fibers with a polymeric resin. The fibrillating step, in the preferred form comprises the application of ultrasonic energy to the decorticated bast fibers. The application of ultrasonic energy in one form of the invention is conducted through liquid to said decorticated bast fibers.
[0021] One advantage of the present invention is having a much finer fiber that conventional decorticated materials as seen the scanning electron micrographs, FIG. 2 a and 2 b.
[0022] Another advantage of the present invention is that significantly greater surface area for bonding with the resin for the same quantity as compared to decorticated materials, as shown in FIG. 4.
[0023] Another advantage of the present invention is that effective wetting and dispersion during compounding with polymeric resins up to 50% by weight loading in the polymers.
[0024] Yet another advantage of the present invention is the availability, due to the prevention of clumping, of development of standard compounded pellets for ease of storage, transportation and handling.
[0025] Still another advantage of the present invention is the injection molding of specimens without any problems with ‘clumping’ or balling up of fibers. Further, injection molding of parts using conventional equipment may be utilized and is now possible.
[0026] Yet another advantage of the present invention is a significant increases in stiffness and strength of the formed composites. Significant benefits in strength and stiffness to weight ratios approaching those of glass reinforced materials have been shown.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
[0028] [0028]FIG. 1 is a graph indicating the strength of various natural fibers showing flax fiber to be the strongest;
[0029] [0029]FIG. 2 is a Scanning Electron Micrograph of (a) decorticated flax fiber (25X) and (b) Fibex fiber of one form of the invention (100X);
[0030] [0030]FIG. 3 is typical surface of molded specimen with decorticated fiber demonstrating ‘clumping’ or ‘balling up’ of fiber during compounding and molding (prior art);
[0031] [0031]FIG. 4 is a cross sectional area comparison of decorticated fiber and the Fibex material of one form of the invention;
[0032] [0032]FIG. 5 is a photograph of one form of Fibex reinforced polypropylene pellets;
[0033] [0033]FIG. 6 is a photograph of injection molded specimens with Fibex (40% by weight) reinforced polypropylene pellets of showing smooth surface without any ‘balling up’ of fibers;
[0034] [0034]FIG. 7 is a photo of injection molded part (hemispherical shell from a double cavity mold) at 30% Fibex fiber loading showing even dispersion of fiber in invention composite resin;
[0035] [0035]FIG. 8 is a graph showing a comparison of strength (a) and stiffness (b) of Fibex reinforced polypropylene with other reinforcements and fillers;
[0036] [0036]FIG. 9 is a graph showing a comparison of strength (a) and stiffness (b) to weight ratio of Fibex reinforced polypropylene with other reinforcements and fillers; and
[0037] [0037]FIG. 10 a and FIG. 10 b are photographs of fibers (a) before and (b) after ultrasonic processing.
[0038] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0039] Unlike other fiber processing technologies applied to bast fibers such as steam explosion (STEX), Fibex does not rely upon the use of solvents, chemicals, microbes or enzymes. As a result, there is no chemical residue. Products made with Fibex will not off-gas volatile organic compounds (VOC's) or emit strong odors commonly associated with flax. The mechanism by which Fibex is made differs fundamentally from the mechanism of the STEX process that is now practiced in Europe. The result is therefore a different composition of matter. Fibex and STEX cellulosic fibers are different compositions of matter when made from the same sample of flax. The compositional differences arise from differences in their manufacturing procedures.
[0040] During the STEX process, pretreatment is necessary in addition to STEX. The pretreatments use one or more of the following: alkaline solutions, surfactants, metal salts, complexing agents, and acid buffers. All of them act in aqueous environments and are intended to hydrolyze and/or dissolve hemicellulose and pectins without much damage to the cellulose polymer in the bast fiber.
[0041] The STEX process is an autohydrolysis process aimed at depolymerizing carbohydrates other than cellulose. In general, the hydrolysis cleaves the polymer chain at the hemiacetal functional groups. It involves cleavage of carbon-to-oxygen bonds. It is operated in a temperature/pH range known to leave cellulose mostly undisturbed while attacking hemicellulose, lignin, and pectins. That is, the temperature is well under the Tg of cellulose and well above the Tg of the other polymers. The end of the process involves release of pressure in which 10 bar to 15 bar pressure is reduced to one bar, suddenly. This mechanical action helps to free the partly depolymerized and solubilized substances from the cellulose fiber.
[0042] In contrast, Fibex processing is a primarily mechanical technology in which the unwanted flax constituents are abraded or scraped from the underlying cellulose. Although water is not rigorously excluded, no water or alkali is necessarily added for Fibex processing. The process does not feature hydrolysis. Brief periods of intensive heating occur as part of the mechanical action. There may be some chemical action under these conditions. The mechanical forces may press some of the non cellulosic material into the cellulose fibers to form thin coatings or even graft polymers. Depending on the Fibex processing conditions that are selected, there may be some decrease in DP of the order of 5% to 15% due to fracture of the polymer chains which is a radical chemical reaction, not a hydrolytic reaction.
[0043] It follows from the above description that the differences in composition of these two products (STEX and Fibex) can be determined by standard analytical methods. Fibex fibers will have a lower percentage of cellulose that STEX fibers will have. Fibex cellulose will have a distinctly higher DP than STEX fibers will have. Detailed analysis of samples of the two types of fibers will show differences in the chemical compositions of the residual films that cling to the cellulose framework.
[0044] In addition to these differences in composition, differences in the polymer morphology can be detected. STEX fibers are likely to show a higher percentage of crystallinity in its cellulose than is found with Fibex. The prolonged heating at elevated temperature and hydrolysis reactions provide the opportunity for the STEX product to move toward the most thermodynamically stable (crystalline) form. Fibex processing does not provide this opportunity due to its quick mechanical action. Based on such differences, Fibex and STEX products are distinctly different compositions of matter.
[0045] The present invention of fibrillated bast type fibers, Fibex production, uses any number of processes, all of which are likely to involve mechanical or shock waves. The preferred process, an ultrasonic process, is one possible method of dispersing the fiber, uses a burst of energy from transducers that operate in an aqueous, air, fluid, or other environment, in which cavitation phenomena are clearly present. The implosion of the tiny bubbles or other particles abrade the hemicellulose and pectin sheath off of the raw cellulose bast fiber.
EXAMPLE
[0046] An experiment was designed to apply ultrasonic energy to selectively break the weaker inter-fiber bonds of flax bast without breaking the main fibers by appropriate levels and modalities of ultrasonic energy.
[0047] The key ultrasonic processing parameters are:
[0048] Ultrasonic vibration amplitude at the active face of the applicator;
[0049] Ultrasonic horn design;
[0050] Ultrasonic frequency;
[0051] Active surface area of the horn;
[0052] Treatment time;
[0053] Fiber-to-water weight ratio;
[0054] Initial state or condition of the decorticated fibers
[0055] Total treatment volume of the water;
[0056] Differing Water treatments (e.g., “alkaline water, 5-μm filtered water, alkaline 5-μm filtered water, tap water etc.”); and
[0057] Post processing of the fibers (e.g., air drying at room temperature).
[0058] A Dukane Corporation 20-kHz ultrasonic power supply with automatic power control was used for all tests. The vibration amplitude of the converter was 20 μm peak-to-peak (pp). Since the power supply is power controlled, this vibration amplitude is a constant at all power settings. A booster with a mechanical gain or amplification of 2.5 was used to amplify the vibration to 50-μm pp. Several types of “horns” or mechanical resonant amplifiers were tried for adequate mixing as well as amplification and control of the vibration amplitude. Visual observations were used for all feedback on performance. An axis-symmetric ultrasonic horn with a gain of 2 and an active surface diameter of 1 inch, was found to perform the best and was used for all subsequent tests. Therefore, the net amplitude at the active surface is 100-μm pp.
[0059] Several trials indicated that a water-to-fiber weight ratio of 400 appears to work the best, when the total weight of water was 200 gm. For each experiment carefully weighed 0.5 gm of dry fiber were added to 200 gm of 5-μm filtered water. Treatment times of 5, 10, 15, 20, 30 and 60 seconds at power settings of 5, 15 and 25 on the ultrasonic generator were utilized. For commercial success, the objective was to investigate good performance with minimum power and time. This led to the selection of treatment time of 20 seconds at the minimum power setting of 5. At these settings, decorticated fibers were place in the ultrasonic field fibrillated to yield sufficient quantities of Fibex for characterization. FIGS. 10 a and 10 b are photographs of the fibers before and after treatment. The fibers were subsequently air dried prior to further evaluation.
[0060] The trials indicated that:
[0061] 1. Ultrasonic fibrillation of decorticated bast fibers in the water medium is very effective;
[0062] 2. Commercially available 20-kHz, 1-kW ultrasonic power supply was adequate;
[0063] 3. The treatment time of 20 seconds was sufficient at the minimum power setting value of 5.
[0064] The fibrillated Fibex material from any of the mechanical wave processing methods can be used to compound with polymers using appropriate coupling agents to promote adhesion between the fibers and the resin. In the first case the Fibex was compounded with and 18 melt flow index (MFI) polypropylene homopolymer (Aristech 180M) using a standard roll mill at 420 F. A maleated polypropylene (MAPP Polybond 3200) was used as the coupling agent. The compound consisted of 30 to 40% by weight Fibex and 1 to 4% by weight MAPP with the balance being the PP homopolymer. The resulting compound was injection molded into standard specimens for evaluating density (per ASTM 638), tensile properties (per ASTM 6), flexural properties, and Izod Impact. The results obtained using Fibex as compared to other data from the literature for flax shives as well as other fillers and reinforcements is shown in FIGS. 8 and 9. As seen in FIG. 8, both the tensile and flexural strength of the new Fibex fibrillated fiber and compound is far superior to all other reinforcements and approach those of glass fibers in PP resins. The results are even more pronounced when compared on a strength to weight ratio basis in FIG. 9.
[0065] The method of formulating Fibex fibers and Fibex composites includes:
[0066] 1. Decortication of the bast fibers from raw materials;
[0067] 2. Fibrillation, decorticated bast fibers with mechanical impact forces; and
[0068] 3. In the preferred form, application of sufficient ultrasonic energy to remove the cellulose polymers from the other constituents. The ultrasonic process may occur in different regimes of power, frequency, container designs, and treatment time. The method then includes taking the fibrillated fibers and compounding same with polymeric thermoplastics (such as, PP, HDPE, LDPE, PVC, Nylon, SAN, Polyurethanes, Polystyrenes) or thermoset (polyesters, vinyl esters, epoxies, etc.), in particular resins that have processing temperatures below 325° C. The method of creation further includes the use of MAPP based coupling agents, or alternate coupling agents between the Fibex fibrillated fibers and the polymeric resins, such as acrylic acid coupling agents, silanes, aminosilanes, and isocynates. Such use of the above coupling agents increase the strength of the resin composition.
[0069] While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. | A decorticated bast fiber such as from flax that is particularly suitable as a reinforcement for polymeric resins, thermoplastic, and thermoset composites. The invention specifically overcomes past difficulties involving compounding and injection molding of composite specimens with bast fiber reinforcements. In one form, ultrasonic energy is applied to decorticated bast fibers to cause fibrillation. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to German Patent Application No. 10 2012 024 977.2 filed Dec. 20, 2012, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
The technical field relates to a light, in particular an exterior light, for a motor vehicle as well as a method for manufacturing such a light and a kit for manufacturing such a light.
BACKGROUND
Exterior lights for motor vehicles such as head lights are these days frequently composed of a plurality of light-emitting diode modules, which are disposed and mounted on a common carrier element. The DE 10 2009 052 340 A1 has disclosed a light-emitting diode module for a motor vehicle illuminating device, which comprises a carrier element and at least one light-emitting diode. The at least one light-emitting diode is mounted and contacted on a lead holder, and the lead holder in turn is mounted and contacted on the carrier element, in order to simplify and standardize the attachment of the light-emitting diode on the light-emitting diode module.
In order to achieve optimal optical conditions in a light, positioning of the illuminant relative to the optics is important. Although it is possible these days to equip circuit boards with light-emitting diodes at negligibly small tolerances, accurate positioning of light-emitting diodes relative to the optical system for conventional lights is, as a rule, relatively cumbersome and thus cost-intensive. This problem needs to be carefully addressed when making changes to the manufacturing process and adapting to changed general conditions (such as changed installation dimensions, beam radiation angle, light outputs, etc.).
In view of the foregoing, it is at least one object to provide an improved light which is easy to adapt to changed general conditions. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
SUMMARY
According to an embodiment, a light comprises a carrier element, an optics and an illuminating device arranged between the carrier element and one or more illuminants mounted on the circuit board. One of the optics and the carrier element comprises one or more positioning elements, which pass through an opening in the circuit board and engage in a recess in the other of the optics and the carrier element, in particular pass therethrough. In one embodiment therefore the optics may comprise one or more positioning elements, which pass through one or more openings in the circuit board and engage in one or more recesses in the carrier element, in particular pass therethrough. Additionally or alternatively the carrier element may comprise one or more positioning elements which pass through one or more openings in the circuit board and engage in one or more recesses in the optics, in particular pass therethrough.
A light according to one embodiment is characterized by being of modular construction comprising, in particular, the following components: the carrier element, the illuminating device and the optics. This allows the light to be easily adapted to changed general conditions, by in particular selecting at least one component from a larger available selection of a (construction) kit and/or adapting at least one component.
When using another illuminant for the light, the light properties for example remain frequently essentially unchanged, allowing a uniform optics to be used. In order to adapt the light to the changed package data by using another illuminant, only the carrier element e.g. needs to be slightly adapted, and this can be achieved in a simple and low-cost manner. Instead of providing several different optics or adapting available optics at increased cost, with this embodiment it is sufficient for a change of illuminant, to simply adapt the carrier element.
The at least one illuminant is preferably a light-emitting diode (LED), an organic light-emitting diode (OLED), a group of light-emitting diodes, a LED chip or the like. The illuminating device preferably contains one illuminant, but in terms of the embodiments two, three or more illuminants may be employed in an illuminating device. Different illuminants comprise at least one different property, which is preferably selected from the following: beam radiation angle, radiation surface, light intensity, color location, power input, etc.
The term carrier element in particular describes an element that is suitable for disposing the illuminating device and the optics in a desired position, in particular a desired position within a light housing. The carrier element is preferably plate-shaped, it may be essentially planar, or alternatively bent one or more times. The carrier element is preferably designed to carry several illuminating devices with associated optics. The shape and size of the carrier element are preferably adapted to the desired number and distribution of the illuminating devices.
The term optics in particular describes an element such as a lens, an aperture, a filter, a reflector and such like. The optics preferably comprises a housing, a frame or the like, in particular a holding structure, which holds the at least one optical element in a desired position. An optics is preferably associated with an illuminating device such that at least one optical element of the optics is arranged in the path of the beam downstream of an illuminant of the illuminating device. At least one positioning element is preferably, in particular permanently or detachably, immovably fixed to the optics or the carrier element, i.e., preferably formed in one piece with the holding structure of the optics or molded onto the same (e.g., by injection molding).
In one embodiment the illuminating device can additionally comprise a substrate, and the at least one illuminant may be attached to the circuit board with this substrate, or may be mounted to the circuit board via this substrate. The use of such a substrate allows for different illuminants to be mounted on a circuit board in a simple way.
According to one embodiment the substrate of the illuminating device may be a substrate selected from several different substrates corresponding to the at least one selected illuminant, and/or may be adapted to the at least one selected illuminant. With the aid of a substrate adapted to the respective illuminant the at least one illuminant can be mounted on a (preferably essentially uniform) circuit board in a simple way. This can further enhance the modularity of this embodiment of the light.
In one embodiment the carrier element can comprise, on its side facing the illuminating device, an adaption recess for at least partially receiving the illuminating device. Provision of such an adaption recess in the carrier element makes it possible, in a simple way, to mount different illuminating devices on a circuit board. With the aid of an adaption recess adapted to the respective illuminant the illuminating device can be mounted in a simple way on a carrier element, in particular an initially essentially uniform carrier element. This can further increase the modularity of this embodiment of the light. The dimensions of the adaption recess, in this embodiment, are preferably adapted to the respective illuminating device. In this context the adaption recess may comprise a depth of zero, i.e., be non-existing, depending upon the illuminating device. An adaption recess may, in particular, be cast in one with the carrier or be manufactured subsequently, in particular by machining.
The at least one positioning element, in one embodiment, can comprise at least one mounting pin provided on the optics, which pin engages in a bore in the circuit board, the substrate and/or the carrier element. In one embodiment three or four mounting pins and a corresponding number of bores are provided, in order to ensure positioning which is as accurate and reproducible as possible; but less than three or more than four mounting pins may be alternatively provided.
Preferably the illuminating device is arranged on the carrier element in such a way that the bores of the two components are essentially positioned so as to be in alignment with each other so that a mounting pin of the optics can engage in the bores of both components. With this embodiment the mounting pin of the optics preferably extends through the bore in the carrier element and is, on the side of the carrier element facing away from the optics, attached by a fixing element, in particular by reshaping the mounting pin. Reshaping preferably means that the mounting pin is reshaped by a process of stamping, in particular hot-stamping, welding, in particular hot-welding, bending, clinching, riveting, etc. According to one embodiment the carrier element is at least partially configured as a cooling body or provided with such a cooling body. Preferably the carrier element is configured as an aluminium die casting for this purpose.
According to a further embodiment the method for manufacturing a light comprises the following steps: attaching or mounting the at least one illuminant on a circuit board of an illuminating device; disposing this illuminating device on a carrier element; and positioning an optics in a predefined position relative to the illuminating device in that at least one positioning element of one of the optics and the carrier element passes through an opening in the circuit board and engages in a recess in the other of the optics and the carrier element.
This method is preferably used for manufacturing the above described light. Using this method allows the same advantages to be achieved as with the above-described light. In one embodiment the at least one illuminant can be attached or mounted on the circuit board via or with a substrate.
The at least one illuminant, in this embodiment, can be selected from several different illuminants. The substrate can then be selected from several different substrates corresponding to the at least one selected illuminant and/or can be adapted to at least one selected illuminant. In one embodiment the at least one illuminant can be selected from several different illuminants, and the carrier element can be adapted to the illuminating device corresponding to the at least one selected illuminant. Additionally or alternatively the optics can be elected from several different optics. The carrier element, in one embodiment, can be provided with an adaption recess corresponding to the at least one selected illuminant for at least partially receiving the illuminating device therein.
In one embodiment the at least one positioning element may comprise at least one mounting pin provided on the optics, which pin, during positioning of the optics, engages in a bore in the circuit board, the substrate and/or the carrier element. The mounting pin of the optics, with this embodiment, may be passed through the bore in the carrier element during positioning of the optics and attached, in particular by reshaping it, on the side of the carrier element facing away from the optics.
According to a embodiment a (construction) kit for manufacturing a light comprises a circuit board, several different illuminants, a carrier element for attaching an illuminating device formed of a circuit board and at least one illuminant, and an optics which can be positioned with the aid of at least one positioning element in a predefined position relative to the illuminating device. Additionally or alternatively to the selection of different illuminants the (construction) kit may comprise several different optics from which one is selected corresponding to the illuminating device, in particular its illuminants, and positioned. Using this kit a light of the above description can preferably be manufactured. With this (construction) kit the same advantages can be achieved as with the above-described embodiment of a light.
In one embodiment the kit may comprise several different substrates for mounting at least one illuminant on the circuit board. The light, the manufacturing process and the (construction) kit can all be used, respectively, for an exterior light of a motor vehicle, preferably for a motor vehicle headlight.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and:
FIG. 1 is a partial cross-sectional view of a light according to an embodiment;
FIG. 2A is a partial cross-sectional view of a first assembly stage of the light according to FIG. 1 ;
FIG. 2B is a partial cross-sectional view of a second assembly stage of the light according to FIG. 1 ;
FIG. 2C is a partial cross-sectional view of a third assembly stage of the light according to FIG. 1 ;
FIG. 3 is a top view of an illuminating device of the light according to FIG. 1 ; and
FIG. 4 is a partial cross-sectional view of a light of a further embodiment.
DETAILED DESCRIPTION
The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description.
FIG. 1 shows an example of part of a motor vehicle headlight according to a first embodiment. The headlight comprises a plate-shaped carrier element 1 , which is manufactured as an aluminium casting and thus simultaneously serves as a cooling body. The carrier element 1 carries a number of light-emitting diode modules as requested by the vehicle manufacturer and disposed as requested by him, but where only one such module is shown in FIG. 1 .
On one side of the carrier element 1 (at the bottom in FIG. 1 ) an illuminating device is arranged. This illuminating device comprises an illuminant 2 , preferably a light-emitting diode (LED) or a LED chip. This illuminant 2 is mounted, i.e., mechanically attached and electrically contacted, to a circuit board 4 via a substrate 3 . The illuminant 2 can be mounted on the circuit board 4 with conventional means and at negligibly small tolerances. The illuminating device 2 - 4 and in particular its illuminant 2 is associated with an optics 5 . The optics 5 comprises a housing which holds a reflector and a lens as optical elements.
The optics housing has several positioning elements 6 in the form of mounting pins molded onto it. These positioning elements 6 allow the optics 5 to be accurately and reproducibly positioned relative to the illuminating device 2 - 4 and to the carrier element 1 . The optics 5 receives the illuminating device 2 - 4 between itself and the carrier element 1 .
Assembly of this light will now be explained in detail with reference to FIGS. 2A-C . After the illuminating device 2 - 4 has been formed by mounting a light-emitting diode 2 via a substrate on the circuit board 4 , this illuminating device 2 - 4 is disposed on the carrier element 1 (See FIG. 2A ).
As illustrated in FIG. 2A , several bores 7 are provided in the circuit board 4 and several bores 8 are provided in the carrier element 1 . The illuminating device 2 - 4 is arranged on the carrier element 1 such that the bores 7 in the circuit board 4 and the bores 8 in the carrier element 1 are in alignment with each other. Preferably the bores 7 and 8 have essentially the same diameter and are disposed congruent with each other.
The number of bores 7 , 8 in the circuit board 4 /in the carrier element 1 coincide with each other and with the number of positioning elements 6 of the optics 5 . As illustrated in FIG. 3 preferably three bores 7 , 8 for three mounting pins 6 are provided. The bores 7 , 8 are all shaped as fitting bores, i.e., their diameter is only slightly larger than the diameter of the mounting pins 6 of the optics 5 .
The optics 5 is pushed onto the illuminating device 2 - 4 with its mounting pins 6 until it is firmly seated on it (See FIG. 2B ). Due to the three mounting pins engaging in the bores 7 , 8 the optics is positioned relative to, and aligned with, the illuminant 2 so as to ensure a precise fit.
The mounting pins 6 of the optics 5 are dimensioned such that in this state of assembly they protrude through the bores 8 in the carrier element 1 (See FIG. 2B ). As indicated in FIG. 2B , the ends of the mounting pins 6 are then reshaped, for example by a process of hot-stamping. In this way the optics 5 is fixed on the carrier element 1 and also attached in its exact position relative to the illuminating device 2 - 4 . The above-described construction of the headlight is characterized by its high modularity, which permits easy adaption to suit changed general conditions.
As an example, for an LED change during running production due to, e.g., end-of-life, supply shortage, or similar, there is the problem with conventional systems that although the optical properties of the LED chip are essentially the same (e.g. Lambertian spotlight), the package data does not match the optical surfaces. With conventional systems the layout of the optics had to be changed in such a case. By contrast, the modular light in the described embodiment makes it possible, to carry out a small adaption of the carrier element 1 to suit the new conditions, at only a small amount of expense.
As illustrated in FIG. 4 , the light in this embodiment contains another light-emitting diode 2 which is of a greater constructional height. The substrate 3 in this case has been adapted to suit the selected light-emitting diode 2 and is also of a greater constructional height. In order to assemble this changed illuminating device 2 - 4 without modification to the optics 5 , a recess is milled into the carrier element 1 . This recess 10 is dimensioned such that it can receive the illuminating device 2 - 4 to a certain extent.
The milled recess 10 in FIG. 4 the non-existing recess in FIG. 1 forms an adaption recess. Due to the above-described modularization of the light a distinct cost reduction in the production process of the light such as, e.g., motor vehicle headlights may result. All that needs to be provided are different illuminants 2 and correspondingly different substrates 3 , whilst the optics 5 can remain the same throughout, and the carrier element 1 requires being adapted to only a minor extent.
Although exemplary embodiments have been discussed in the above description, it is pointed out that a multitude of variations is possible. Besides it is pointed out that the exemplary embodiments are merely examples and not intended to limit the scope of protection, the applications and the construction in any way. Rather the above description is meant to be a guideline for the expert to help realize at least one exemplary embodiment, wherein various changes, in particular in view of the function and layout of the described components, can be carried out without leaving the scope of the protection, as revealed in the claims and these equivalent feature combinations. | A light is provided and a method is provided for manufacturing a light, with a carrier element, an illuminating device disposed on the carrier element with a circuit board and an illuminant mounted on the circuit board, and an optic. The one of the optics and the carrier element comprises at least one positioning element, which passes through an opening in the circuit board and engages in a recess in the other of the optics and the carrier element. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bootstrap pilot circuit in N-MOS technology for capacitive loads.
2. The Prior Art
A bootstrap circuit is known to be a circuit capable of bringing about an oversupply of the gate of the load transistor for a high conduction of said transistor.
Due to the effect of these characteristics the use of bootstrap circuits is frequent in N-MOS technology when it is desired to pilot with short response time a capacitive load of considerable value. The high conduction of the load transistor developed with the bootstrap circuit makes it possible to have rapid commutation of the output from low to high level.
A typical bootstrap circuit calls for separate piloting (but made appropriately sequential) of a load transistor and of a drive transistor in series and the interposition of a bootstrap condenser between the gate of the load transistor and the output, coinciding with an intermediate point between the two transistors.
With the drive transistor on and the load transistor off a pilot signal is first sent to the load transistor gate, which goes on, bringing about a simultaneous conduction condition of the two transistors. The same signal brings about loading of the bootstrap condenser, which holds the load transistor gate high. A second pilot signal is then sent to the drive transistor gate, which turns off, allowing the load transistor to make the output level rise and thus bring the load transistor gate higher due to its superconduction.
This known circuit has several drawbacks which can be summarized as (a) strong absorption of current between one pilot signal and the next due to the simultaneous conduction effect of the two transistors, (b) the need to oversize the drive transistor to obtain in the abovesaid phase as well as a good output voltage at low level, and (c) sequential piloting of two inputs with the resulting signal timing problems, in general by the use of delay lines which can be rather complex and cumbersome.
SUMMARY OF THE INVENTION
Considering this, the object of the present invention is to accomplish a pilot circuit equipped with a bootstrap conceived in such a manner as to achieve the objective of rapid commutation of the output while remaining free of the above drawbacks.
In accordance with the invention said object has been achieved by means of a pilot circuit with bootstrap comprising a load transistor and a normally on drive transistor connected in series between a supply and ground, a pilot input connected to the drive transistor gate in such a manner as to bring about extinction in response to a pilot signal applied to said input, a bootstrap condenser, and an output connected to a node intermediate between said transistors, characterized in that said bootstrap condenser is interposed between the circuit output and a circuit node controlled by said pilot signal in such a manner as to be commutable from a condition of normal operational connection to the circuit supply to a condition of operational conection to the gate of the load transistor to turn on the latter with bootstrap effect.
With this arrangement current consumption is minimal because the load and drive transistors are never in conduction at the same time. This obviates any need for oversizing the drive transistor to obtain a good output voltage at low level.
In addition there is only one pilot signal so that there are no longer any problems of timing as found with the known arrangement.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention will be made clearer by the following detailed description of some practical embodiments thereof illustrated as examples in the annexed drawings in which:
FIG. 1 shows an example of accomplishment of the pilot circuit with bootstrap in accordance with the invention,
FIG. 2 shows a variant of the above circuit, and
FIG. 3 shows another variant of the circuit of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1 there is illustrated a pilot circuit including a load transistor 1 of the enhancement type, the natural type or the depletion type and a drive transistor 2 of the enhancement type connected in series between a positive supply V cc and ground. A node 3 intermediate between the transistors 1 and 2 constitutes the circuit output to which is applied the capacitive load C under control.
A pilot input 4 suppliable with a pilot signal for commutation of the output 3 from a normal low level to the high level suitable for piloting the capacitive load C is connected to the gate of the drive transistor 2.
Said input 4 is also connected to the gate of a depletion transistor 5 connected in series with an enhancement transistor 6 between a supply V cc and the input 4.
Again the input 4 is connected to the gate of an enhancement transistor 7 inserted in series with two depletion transistors 8 and 9 between a supply V cc and ground. A circuit node 10 intermediate between the transistors 7 and 8 is connected to the gate of the transistor 6 and to the gate of the load transistor 1. The gate of the transistor 9 is in turn connected to a circuit node 11 intermediate between the transistors 5 and 6.
The input 4 is finally connected to the gate of an enhancement transistor 12 which together with a depletion transistor 13 is connected in parallel to the transistors 7 and 8 between a circuit node 14 and earth. The gate of the transistor 13 is connected to its own source and to the gate of the transistor 8.
A bootstrap condenser 15 is finally interposed between the output 3 of the circuit and the circuit node 14. The condenser 15 is thus connected to the gate of the load transistor 1 through the depletion transistor 8, i.e. through a circuit element controlled in accordance with the known art instead of directly.
When at rest the signal at the pilot input 4 is at high level and the enhancement transistors 2, 7 and 12 are therefor on, i.e. they conduct current. The circuit node 10 is thus low and keeps the transistor 6 extinguished. The transistor 5 is on together with the transistor 9 which is strongly on and has a load the transistor 8 and 13, both at low conduction because their gate and source are low and the drain is connected to the node 14 (configuration with current generator). The transistor 9 has to be sized in such a manner that the voltage drop in the node 14 in relation to the supply voltage V cc is not excessively high since said drop results in a loss of efficiency.
Since the node 10 is low the load transistor 1 has its gate grounded so that it is in a minimum current condition. Then if the transistor 1 is of the enhancement type the current absorption in the output branch 1, 2 is null and the only absorption in the entire circuit is given by the transistors 8 and 13.
Under these conditions, i.e. with the transistor 2 on and the transistor 1 in weak or null conduction the output 3 is low and the bootstrap condenser 15 which is interposed between said low output and the high node 14, is preloaded at the voltage of the node 14, which is just below V cc .
Upon arrival of a low level pilot signal at the piloting input 4 the transistors 2, 7 and 12 go off and the transistor 8 through the transistor 13 still in conduction has its gate connected to the drain (node 14). The transistor 8 is thus in strong conduction, i.e. in the best condition to describe a low-resistance path for rapid transfer of loads from the condenser 15 to the gate of the load transistor 1. That is, the condenser 15 is connected in parallel between the output 3 and the gate of the transistor 1, i.e. between the source and the gate of the transistor 1.
This operation must take place necessarily with time constant lower than the rise time of the output 3 if it is desired to avoid its becoming a limiting factor.
The transistor 6 being still momentarily extinguished ensures that the gate of the transistor 9 is brought to ground only when there is occurring transfer of loads from the condenser 15 to the transistor 1 preventing, during commutation, discharge, even though partial, of the condenser 15 due to the effect of the transistors 8 and 13 which are no longer supported due to extinction of the transistor 9.
In this manner the efficiency of the bootstrap function no longer depends strongly on the commutation time of the input signal although it should be remembered that an excessively loose commutation front of the input signal would tend to not justify use of the bootstrap circuit to speed up commutation.
Returning to the operation of the circuit of FIG. 1 the described connection of the bootstrap condenser 15 to the gate of the load transistor 1 turns on the transistor 1 which begins to take the output 3 high. As said output 3 rises so does the voltage of the circuit node 14 which, not finding discharge paths, can go above the supply voltage V cc . Once the paths constituted by the transistors 7 and 12, which are safety extinguished, are excluded there can also be excluded the path constituted by the transistor 9 since having drain at the voltage V cc and gate to ground (node 11) the transistor 9 is extinguished by source voltage (node 14) higher than the Pinch voltage (negative gate voltage which would extinguish the transistor), a condition usually respected in the characteristics typical of the load transistor used in N-MOS technology.
With the described diagram there can readily be obtained bootstrap efficiencies over 70% thus making easy the use of an enhancement transistor as the load transistor 1. In this manner as already mentioned the load transistor normally does not conduct so that there is maximum efficiency in terms of consumption of the output branch 1, 2. Good efficiency is obtainable in any case by utilizing as a load transistor even natural or slightly depleted transistors.
Upon increase of implantation of the transistor 1, the more the absolute Pinch voltage value of said transistor approaches the supply voltage and the less efficient the system will become in terms of performance/consumption.
It should be noted that employment of the circuit diagram of FIG. 1 is amply justified for high capacitive loads (a few dozen picofarad).
For lower output loads (up to 10 picofarad) it may be profitable, if there are surface area saving problems, to use a simpler diagram such as the one shown in FIG. 2 which does not have the transistors 13 and 12 and the related circuit branch and has the gate of the transistor 8 connected to the node 10.
If the commutation front of the input signal from high to low is extremely fast and there is no concern for a small loss of bootstrap efficiency, there may be used the diagram of FIG. 3 which likewise does not have the transistors 5 and 6 and the related circuit branch and has the gate of the transistor 9 connected directly to the input 4. | A bootstrap condenser connected to the output of the circuit is preloaded during the low output state when the load transistor is off and the drive transistor is normally on. A commutation signal brings about extinction of the drive transistor and connection of the condenser to the gate of the load transistor to turn on the latter and secure the resulting rise of the circuit output. Transistors of the pilot circuit are arranged for maximum bootstrap efficiency. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates, in general, to an embroidery machine and, more particularly, to an apparatus for lifting the presser foot of an embroidery machine.
[0003] 2. Description of the Related Art
[0004] Generally, an embroidery machine is a biaxial positioning control machine in which an embroidery stitch frame for fixing fabric undergoes horizontal motion in x-axis and y-axis directions while a needle bar thereof moves up and down.
[0005] Since this embroidery machine does needlework while the embroidery stitch frame fixing the fabric is transferred in x-axis and y-axis directions, the precise and constant-speed movement of the embroidery frame has a close relationship to the quality of an embroidered pattern.
[0006] Thus, as a source of power for driving the needle bar of the embroidery machine in a vertical direction, a servo motor, an induction motor capable of controlling speed, or the like is used. As the power source for transferring the embroidery stitch frame in x-axis and y-axis directions, a stepping motor, ensuring good positioning and easy control, is typically used.
[0007] The embroidery machine has a sewing frame movably installed on a table, and comprises a lifting mechanism, in which, during sewing, a presser foot, described below, is supported at the bottom dead point and moves the presser foot back to the top dead point, which is higher than the bottom dead point.
[0008] FIG. 1 is a perspective view illustrating one example of an embroidery machine, and FIG. 2 is a perspective view illustrating the driving structure of a presser foot in a known embroidery machine. As illustrated in FIG. 1 , an embroidery machine 1 has a plurality of heads, which is installed at the front thereof in a longitudinal direction. Each head includes a needle bar supporting case 4 , which is provided with a plurality of presser feet 5 (each of which is a member used to press a sewing material such as a sheet of cloth to be sewn), at the front of an arm 3 .
[0009] As illustrated in FIG. 2 , each presser foot 5 is adapted to cooperate with a needle bar 8 so as to pivot in a vertical direction. A motor (not shown), providing power, is installed below one side of a table of the embroidery machine, and is connected to a controller for controlling sewing operation. The motor is connected with an upper shaft 6 , which provides driving force and passes through the arm 3 in a horizontal direction.
[0010] Further, a driving cam 10 for the presser foot is mounted on the upper shaft 6 . The driving cam 10 is coupled with a transmission member, which is made up of a cam roller 9 and a driving lever 11 for the presser foot, in an orbital groove thereof. Thus, the transmission member makes an oscillating motion, and pivots around a predetermined pivoting point in a vertical direction.
[0011] In addition, a needle bar guide shaft 7 is mounted on the arm 3 in a vertical direction. A needle bar 8 is installed parallel to the needle bar guide shaft 7 , and passes through the head 4 in a vertical direction. The presser foot 5 is coupled to the lower end of the needle bar 8 .
[0012] A driving block 13 for the presser foot is fitted around the needle bar guide shaft 7 , so that the driving block 13 reciprocates along the needle bar guide shaft 7 in proportion to the amount that the driving lever 11 is pivoted, and thus moves the presser foot 5 in a vertical direction.
[0013] At this time, it is difficult to adjust the height at which the presser foot 5 is placed on the sewing material because it is bent in a stepped shape at a predetermined length when viewed overall.
[0014] Further, in order to adjust the position of the presser foot 5 , the parts of the head 4 , such as a head cover plate (not shown), must be removed. Reference numeral 12 , which has not yet been described, indicates a driving lever connecting link for the presser foot.
SUMMARY OF THE INVENTION
[0015] Accordingly, the present invention has been made to solve the foregoing problems with the related art, and the present invention is intended to propose an apparatus for lifting a presser foot of an embroidery machine, which can adjust the height of the presser foot.
[0016] Another object of the present invention is to provide an apparatus for lifting a presser foot of an embroidery machine, which easily replaces a sewing material or a sewing frame when replaced.
[0017] In order to achieve the above objects, according to one aspect of the present invention, there is provided an apparatus for lifting the presser foot of an embroidery machine, which includes an arm having an upper shaft providing a driving force; a presser foot driving cam mounted on the upper shaft; a transmission member coupled to the presser foot driving cam and making an oscillating motion; a presser foot driving lever connected to the transmission member and pivoting around a predetermined pivoting point thereof in a vertical direction; a presser foot driving block reciprocating along a needle bar guide shaft according to an amount that the presser foot driving lever is pivoted and moving the presser foot in a vertical direction; and a presser foot height adjustor, which displaces the pivoting point of the presser foot driving lever so as to adjust the height of the presser foot.
[0018] According to an embodiment of the present invention, the presser foot height adjustor includes a driving motor, generating the driving force, a driving pulley, rotatably coupled to the driving motor, a driven pulley, pivotably coupled to the driving pulley, an eccentric member, installed on the driven pulley, and a presser foot driving lever, hinged to the eccentric member at a pivoting point thereof.
[0019] According to another embodiment of the present invention, the apparatus further comprises a cylindrical supporting means for an eccentric member, which is connected to the driven pulley and has a hole through which the eccentric member passes.
[0020] According to a further embodiment of the present invention, the eccentric member includes large and small spindles on opposite sides of a circular body thereof, the small spindle being connected in a hinge hole of the presser foot driving lever, and the large spindle passing through the supporting means to be connected to the driven pulley.
[0021] According to another embodiment of the present invention, the presser foot height adjustor adjusts the height of a bottom dead point of the presser foot according to the thickness of the sewing material.
[0022] According to yet another embodiment of the present invention, the presser foot height adjustor adjusts the height of the bottom dead point of the presser foot to a programmed height according to the thickness of the sewing material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:
[0024] FIG. 1 is a perspective view illustrating one example of an embroidery machine;
[0025] FIG. 2 is a perspective view illustrating the driving structure of a presser foot in a known embroidery machine;
[0026] FIG. 3A is a perspective view illustrating the state in which an apparatus for lifting the presser foot of an embroidery machine according to an exemplary embodiment of the present invention is installed;
[0027] FIG. 3B is an enlarged view illustrating part “A” of FIG. 3A ;
[0028] FIG. 4 is an exploded perspective view illustrating an apparatus for lifting the presser foot of an embroidery machine according to an exemplary embodiment of the present invention;
[0029] FIG. 5A is a partial perspective view illustrating the state in which an apparatus for lifting the presser foot of an embroidery machine according to an exemplary embodiment of the present invention is installed;
[0030] FIG. 5B is an enlarged view illustrating part “B” of FIG. 5A ; and
[0031] FIG. 6 is a side view illustrating the operation of an apparatus for lifting the presser foot of an embroidery machine according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Reference will now be made in greater detail to an apparatus for lifting the presser foot of an embroidery machine according to an exemplary embodiment of the invention with reference to the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.
[0033] FIG. 3A is a perspective view illustrating the state in which an apparatus for lifting the presser foot of an embroidery machine according to an exemplary embodiment of the present invention is installed, and FIG. 3B is an enlarged view illustrating part “A” of FIG. 3A . FIG. 4 is an exploded perspective view illustrating an apparatus for lifting the presser foot of an embroidery machine according to an exemplary embodiment of the present invention.
[0034] Further, FIG. 5A is a partial perspective view illustrating the state in which an apparatus for lifting the presser foot of an embroidery machine according to an exemplary embodiment of the present invention is installed, and FIG. 5B is an enlarged view illustrating part “B” of FIG. 5A . FIG. 6 is a side view illustrating the operation of an apparatus for lifting the presser foot of an embroidery machine according to an exemplary embodiment of the present invention. Referring to the drawings, the apparatus for lifting the presser foot of an embroidery machine according to the present invention comprises a height adjustor for a presser foot, which displaces the pivoting point of a presser foot driving lever to adjust a height of the presser foot.
[0035] The presser foot height adjustor functions to displace the pivoting point of the presser foot driving lever to adjust the height of the presser foot. To this end, as illustrated in FIGS. 3A and 4 , the presser foot height adjustor comprises a driving motor, a driving pulley rotatably coupled to the driving motor, a driven pulley pivotably coupled to the driving pulley, an eccentric member installed on the driven pulley, and a presser foot driving lever hinged to the eccentric member at a pivoting point thereof.
[0036] As illustrated in FIGS. 3A and 4 , the driving motor 40 has a protruding shaft on one side thereof, and is fastened to one side of an arm 23 through a connecting bracket 41 , which is connected to a motor case housing of the driving motor 40 and has a C-shaped cross-section when viewed from the side of the motor case, using screws (not shown).
[0037] Further, the driving pulley 42 is coupled to the shaft of the driving motor 40 , and is connected to the driven pulley 43 , which has a relatively greater diameter, through a belt 46 . The eccentric member 45 passes through a cylindrical supporting means 44 having a hole 44 a , and is installed on the driven pulley 43 .
[0038] In the present invention, the driving pulley 42 and the driven pulley 43 are connected with each other through the belt 46 . Alternatively, the driving pulley 42 and the driven pulley 43 may be engaged with each other.
[0039] As illustrated in FIG. 4 , the eccentric member 45 includes large and small spindles on opposite sides of a circular body 45 a . The small spindle 45 b protrudes from an edge of the body 45 a , which is displaced from the center of the body 45 a , and is connected in a hinge hole 31 a of the presser foot driving lever 31 . The large spindle 45 c passes through the supporting means 44 and the driven pulley 43 in series.
[0040] As illustrated in FIG. 4 , the presser foot driving lever 31 has an obtuse V shape, includes the hinge hole 31 a in the middle thereof and large and small through-holes 31 b and 31 c in opposite ends thereof, and is hinged to the eccentric member 45 through the hinge hole 31 a.
[0041] As for a transmission member of the prevent invention, which is equivalent to the transmission member constituted of the cam roller 9 and the presser foot driving lever 11 , as illustrated in FIG. 2 , a presser foot driving cam 30 is coupled to the outer circumference of the upper shaft 26 , as illustrated in FIG. 4 . An arm protruding from the outer circumference of the presser foot driving rod 30 is connected to the through-hole 31 b of the presser foot driving lever 31 , and the through-hole 31 c of the presser foot driving lever 31 is connected with a stub 34 a of one end of a presser foot connecting link 34 , as illustrated in FIG. 3B . The other end of the presser foot connecting link 34 is fixedly coupled to one side of a presser foot driving block 33 , which slides on a guide shaft 27 ( FIG. 3A ) for the needle bar in a vertical direction.
[0042] Further, the presser foot driving block 33 is provided therein with a presser foot connecting holder 37 ( FIG. 5B ), which drives a presser foot driving holder 36 , which is installed so as to be able to slide on the outer circumference of the needle bar 28 . Thereby, the presser foot driving shaft 32 , which is installed parallel to the needle bar 28 under the presser foot driving holder 36 , moves up and down, and thus the presser foot 25 , installed below the presser foot driving shaft 32 , moves up and down.
[0043] The reference numeral 33 indicated in FIGS. 3B , 5 A and 6 is the presser foot driving block, which has the same configuration and driving mechanism as one (reference numeral 26 ) disclosed in Korean Patent Application No. 10-2007-0005680 (entitled Presser Foot Guide Structure of Embroidery Machine), which was filed by the present applicant. The configuration and driving mechanism of the presser foot 25 coupled to the presser foot driving block 33 are described in detail in the above-mentioned prior application and in an application (Korean Patent Application No. 10-2007-0020471, entitled Presser Foot Driving Structure of Embroidery Machine) that establishes the internal right of priority for this patent application, and so a detailed description thereof will be omitted.
[0044] Now, the operation of the present invention having the above-mentioned configuration will be described.
[0045] As illustrated in FIG. 6 , when the upper shaft 26 is rotated by the driving force of the motor (not shown), the presser foot driving rod 30 rotates around the upper shaft 26 . Simultaneously, the presser foot driving block 33 , which is connected to the presser foot driving lever 31 through the connecting link 34 , repeats upward and downward movement.
[0046] Further, the needle bar 28 , which is connected to the lower portion of the presser foot driving holder 36 , which is engaged with the presser foot driving block 33 , moves in the head 24 in a vertical direction, and the presser foot 25 , which is connected to the lower end of the presser foot driving shaft 32 , installed parallel to the needle bar 28 , also moves up and down.
[0047] Meanwhile, in the case in which an attempt is made to raise the presser foot 25 to a predetermined height, as necessary, the driving pulley 42 is rotated by the counterclockwise operation of the driving motor 40 . This rotating force is transmitted to the driven pulley 43 through the belt 46 , and then to the presser foot driving lever 31 through the cylindrical supporting means 44 and the eccentric member 45 .
[0048] Thus, the transmitted rotating force moves the presser foot driving block 33 upwards through the connecting link 34 connected to the presser foot driving lever 31 , and the needle bar 28 connected to the presser foot driving holder 36 engaged with the presser foot driving block 33 moves upwards. At this time, the presser foot 25 connected to the presser foot driving shaft 32 is also raised to a predetermined height.
[0049] In contrast, in the case in which an attempt is made to lower the presser foot 25 to a predetermined height, the rotating force caused by clockwise operation of the driving motor 40 moves the presser foot driving block 33 downwards through the connecting link 34 , and the needle bar 28 connected to the presser foot driving holder 36 moves downwards. At this time, the presser foot 25 connected to the presser foot driving shaft 32 is also lowered.
[0050] Thus, the apparatus for lifting the presser foot makes it possible to adjust the height of the bottom dead point of the presser foot 25 on the basis of the thickness of the sewing material. In other words, the pivoting point of the presser foot driving lever 31 , which is connected to the apparatus for lifting the presser foot, is displaced to make it possible to adjust the height of the presser foot 25 . In the case in which the sewing material is relatively thick, the height of the bottom dead point of the presser foot 25 is increased through the apparatus for lifting the presser foot. In contrast, in the case in which the sewing material is relatively thin, the height of the bottom dead point of the presser foot 25 is decreased through the apparatus for lifting the presser foot. Thereby, sewing is performed.
[0051] Meanwhile, the driving motor 40 can be automatically controlled through a program that takes into account the thickness of the sewing material if necessary. For example, the embroidery sewing frame fixing the fabric is slightly transferred in x-axis and y-axis directions when a sewing pattern is input, and then the position at which the thickness of the sewing material is changed is checked manually. The position and the height from the needle plate (not shown) of the presser foot 25 , depending on the thickness of the sewing material at the position (or the number of driving pulses from the driving motor), are input as data. Alternatively, instead of the input data, the number of needles counted up to the position at which the thickness of the sewing material is changed may be set.
[0052] With this configuration, when the presser foot reaches the position at which the thickness of the sewing material changes during sewing, a number of pulses (or a predetermined number of needles) is supplied according to the height input to the driving motor 40 . Thereby, the position of the bottom dead point of the presser foot 25 can be automatically controlled.
[0053] As apparent from the above description, according to the present invention, the height of the presser foot can be adjusted according to the type and thickness of the sewing material.
[0054] Further, when the sewing material or the sewing frame is replaced by an operator, the presser foot is manually or automatically displaced to the top dead point, which is higher than the bottom dead point. Thereby, the replacement can be easily performed.
[0055] In addition, the trouble of removing the parts of the head, such as a head cover plate, in order to adjust the position of the presser foot, is eliminated.
[0056] Although an exemplary embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. | An apparatus for lifting the presser foot of an embroidery machine includes an arm having an upper shaft providing a driving force, a presser foot driving cam mounted on the upper shaft, a transmission member coupled to the presser foot driving cam and making an oscillating motion, a presser foot driving lever connected to the transmission member and pivoting around a predetermined pivoting point thereof in a vertical direction, a presser foot driving block reciprocating along a needle bar guide shaft according to an amount that the presser foot driving lever is pivoted and moving the presser foot in a vertical direction, and a presser foot height adjustor, displacing the pivoting point of the presser foot driving lever to adjust a height of the presser foot. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part application of the following applications: (1) U.S. patent application Ser. No. 09/840,920, entitled “Scene-based non-uniformity correction for detector arrays”, filed Apr. 25, 2001, and published as Publication No. 2002/0159101 on Oct. 31, 2002; (2) U.S. patent application Ser. No. 09/841,081, entitled “Dynamic range compression”, filed Apr. 25, 2001, and published as Publication No. 2002/0159648 on Oct. 31, 2002; (3) U.S. patent application Ser. No. 09/841,079, entitled “Extended range image processing for electro-optical systems”, filed Apr. 25, 2001, and published as Publication No. 2002/0159651 on Oct. 31, 2002; and (4) U.S. patent application Ser. No. 10/125,348, entitled “Scene-based non-uniformity offset correction for staring arrays”, filed Apr. 19, 2002, and published as Publication No. 2003/0198400 on Oct. 23, 2003, and the specifications thereof are incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable.
COPYRIGHTED MATERIAL
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention (Technical Field)
The present invention relates to image enhancement of digital images, particularly via processing image data acquired via Electro-Optical (EO) systems.
2. Description of Related Art
EO systems are often used for “remote sensing.” The term “remote sensing” generally refers to the acquisition and measurement of data/information related to one or more properties of a phenomenon, object, or material by a recording device not in physical contact with the object under surveillance. Imaging techniques often involve gathering information by measuring electromagnetic fields, electromagnetic radiation, or acoustic energy using cameras, radiometers, scanners, lasers, radio frequency receivers, radar systems, sonar, thermal devices, seismographs, magnetometers, gravimeters, scintillometers, and like instruments. For example, such data can be acquired and interpreted to remotely sense information about features associated with a target.
Intelligence gathering, particularly within strategic, tactical, or otherwise hostile environments, often relies on technology generally referred to as Enhanced Vision (EV) systems. Through the use of imaging sensors, such as Charge-Coupled Device (CCD) cameras, Forward-Looking Infrared (FLIR), vidicon cameras, Low Light Level cameras, laser illuminated cameras, and the like, targets can be acquired and imagery can be processed and viewed at significantly longer ranges than otherwise possible.
With reference to, for example, FLIR systems, remote sensing can refer to the detecting and measuring of electromagnetic energy, usually thermal or photonic, emanating from distant objects made of various materials. Using FLIR imaging, objects can be identified and categorized by, for example, class, type, substance, or spatial distribution.
To facilitate the acquisition and processing of information from EO systems, sensors can be used on a system's front end to generate raw data for processing. Such sensors can be radar imaging sensors, infrared imaging sensors, electro-optic sensors and the like. In each case, information from which image features can be derived can be used to generate image frames which can then be input to, for example, a display system. Image frames can be integrated with other operational features to form a stable display and to allow for such functions as target identification, acquisition, and tracking to be performed. Such systems can be linked to defense systems to provide guidance input and ordnance control.
In conventional EO systems, the sensors used are limited in their resolution by the fixed spacing between sensor elements. Because of the Nyquist frequency of the sensor as determined by element spacing, image artifacts such as aliasing can be evident in the displayed imagery. A similar type of distortion can arise in, for example, a scene containing edge transitions which are so close together that a sensor cannot accurately resolve them. Resultant distortion can manifest itself as color fringes, in a color camera, around an edge or the like, reducing the ability of a viewer to perceive, for example, letters or object outlines with clarity. Range performance of an EO sensor is also often limited by the Nyquist frequency of the sensor, particularly those containing staring focal-plane arrays. In addition, sensor range can be limited by distortion levels or noise associated with sensor construction.
A conventional method of improving the range performance of an EO system is to improve upon the optics of the system. Such improvements include increasing the focal length of the optics and improving the F/number, i.e., the ratio between the focal length and the aperture size (diameter of a lens), of the system. These types of improvements, however, increase the cost and size of the system, which can lead to a design that is too costly or too large to fit the application.
One technique for addressing the range performance and Nyquist frequency limitations of an EO system is to dither the system, such that the system will sample once, then move the sensor over some sub-pixel amount, and then sample again. Such a technique gives the EO system the appearance that the image is sampled twice as often, and, therefore, the Nyquist frequency of the sensor has effectively doubled. This is often implemented using a dither mechanism such as a Fast Scan Mirror (FSM). However, dither mechanisms, such as a FSM, are usually very expensive and are sensitive to vibrations and alignment.
Accordingly, it is desirable to improve the range performance of EO systems while preserving the integrity of existing EO systems.
The base XR (extended range) technology as disclosed in U.S. patent application Ser. No. 09/841,079, referenced above, is an excellent first step toward image fidelity enhancement; however, this approach is limited in a number of ways. First, the base XR algorithm is limited in practice to a very small sub-image of about 64×64 pixels. Second, the base XR algorithm can only improve those pixels within the image that are moving in unison such that if the XR window is tracking a moving target, all other details outside that target are obscured. Third, if one were to try to utilize the base XR algorithm on a fixed wing aircraft, the change in perspective caused by the aircraft's own motion will degrade the XR algorithm's effectiveness. Finally, for target classification purposes, the base XR algorithm is useful for classification of an already detected target, but one cannot effectively employ it until after one has already located the target, particularly because of the small sub-image limitation.
The approach taken by the present invention solves such problems, though it comes at some hardware expense. In order to offer the best fidelity improvement at each location within the image, each pixel needs to be compensated independently of every other pixel. This requires that a unique motion vector be generated for each and every pixel of the output region.
The base XR algorithm of U.S. patent application Ser. No. 09/841,079 employs a motion vector used to align the current (electronically zoomed) input image with a reference image. This works perfectly as long as all the pixels in the input image experience the same motion relative to the sensor. Of course, all pixels that move differently than the average motion of the group will be blurred by the algorithm or at best case, they will receive no improvement.
The present invention dedicates a separate correlation tracking algorithm to each pixel within the desired output image. Using this technique, each pixel receives individual motion compensation based on matching the local neighborhood between the reference frame and the input image.
BRIEF SUMMARY OF THE INVENTION
The present invention is of a method for processing imagery using an Electro-Optical (EO) system, comprising: selecting a first frame of data as a template frame; capturing a second frame of data using the EO system; for a plurality of pixels of the second frame, correlating the plurality of pixels of the second frame with pixels of the template frame to generate a plurality of shift vectors, one for each pixel of the plurality of pixels of the second frame; registering the second frame with the template frame by interpolating the second frame using the plurality of shift vectors and re-sampling at least a portion of the second frame to produce a registered frame; re-sampling the template frame; and combining the re-sampled template frame and the registered frame to generate an averaged frame. In the preferred embodiment, re-sampling comprises electronic zooming. It is preferred to digitally enhance and/or filter the second frame. Registering motion compensate aligns the second frame to the template frame or motion compensate aligns the template frame to the second frame. Preferably, at least the registering step is executed by a Geometric Arithmetic Parallel Processor (GAPP) processor, with each pixel of the second frame having a one-to-one correspondence with processing elements of the GAPP processor. Alternatively, at least the registering step is executed by a Field Programmable Gate Array (FPGA). Registering and resampling result in a unique reference image comprising the re-sampled template frame for each pixel of the second frame. A user is preferably permitted to switch to an alternate method of image enhancement providing a single shift vector rather than one for each pixel of the second frame.
The invention is also of an Electro-Optical (EO) system for processing imagery, comprising: a sensor for generating input data; and a processor module coupled to the sensor, the processor module configured to: select a first frame of data as a template frame; capture a second frame of data using the EO system; for a plurality of pixels of the second frame, correlate the plurality of pixels of the second frame with pixels of the template frame to generate a shift vector a plurality of shift vectors, one for each pixel of the plurality of pixels of the second frame; register the second frame with the template frame by interpolating the second frame using the plurality of shift vectors and re-sampling at least a portion of the second frame to produce a registered frame; re-sample the template frame; and combine the re-sampled template frame and the registered frame to generate an averaged frame. In the preferred embodiment, the processor module re-samples via electronic zooming. The processor module is additionally configured to digitally enhance and/or filter the second frame. The processor module registers by motion compensate aligning the second frame to the template frame or by motion compensate aligning the template frame to the second frame. The processor module preferably comprises a Geometric Arithmetic Parallel Processor (GAPP) processor, wherein each pixel of the second frame has a one-to-one correspondence with processing elements of the GAPP processor. Alternatively, the processor module comprises a Field Programmable Gate Array (FPGA). The processor module by registering and resampling creates a unique reference image comprising the re-sampled template frame for each pixel of the second frame. It preferably additionally permits a user to switch to an alternate type of image enhancement providing a single shift vector rather than one for each pixel of the second frame.
The invention is further of an Electro-Optical (EO) system for processing imagery, comprising: a sensor for generating input data; and a processor module coupled to the sensor, the processor module comprising a Geometric Arithmetic Parallel Processor (GAPP) processor and configured to: select a first frame of data as a template frame; capture a second frame of data using the EO system; and for a plurality of pixels of the second frame, correlate the plurality of pixels of the second frame with pixels of the template frame to generate a shift vector a plurality of shift vectors, one for each pixel of the plurality of pixels of the second frame.
Objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings:
FIG. 1 is a block diagram of the preferred image enhancement system of the present invention; and
FIG. 2 is a flow diagram of the preferred method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is of a system and method for enhancing digital images, particularly those acquired by EO systems. The invention dedicates a separate correlation tracking algorithm to each pixel within the desired output image. Using this technique, each pixel receives individual motion compensation based on matching the local neighborhood between the reference frame and the input image. The invention provides a larger coverage area than with existing technology, thereby providing enhanced imagery for any application, particularly for target detection. The invention also provides per-pixel motion compensation, with concomitant higher quality images, particularly in scenarios where the current XR technology would have difficulty.
The invention preferably performs a per-pixel registration of electronically zoomed successive video frames to provide enhanced image fidelity. Electronic zoom normally just creates pseudo-data between pixels; however, by temporally blending in motion adjusted data, the invention can actually “fill in the data holes” with real image detail. The invention preferably proceeds via the following steps:
(1) Input image is electronically zoomed by 2×, 4×, or even 8× or more;
(2) The electronically zoomed input image is preferably digitally enhanced/filtered according to known methods as described, for example, in the four related applications first mentioned above;
(3) The filtered, zoomed input image is compared to a reference image to determine the per-pixel motion between the reference and the input image pixels;
(4) Depending upon the operational mode, either the input pixels are motion compensation aligned to the reference image, or the reference image pixels are motion compensation aligned to the input image; and
(5) If the comparison results in a sufficiently close match, the aligned data is blended together into the output image. The output image becomes the new reference image.
FIG. 1 is a block diagram of the preferred system 10 of the invention. An input image is provided by a video device 12 to a sensor interface unit 14 , which then outputs a processed image to a receiving device 16 (e.g., a personal computer, computer monitor, or like processing or display apparatuses).
The video device can be, for example, a CCD camera, FLIR, a vidicon camera, a Low Light Level camera, a laser illuminated camera, or any other EO sensor capable of collecting image data. The sensor interface unit preferably comprises a processor module including a Bi-Linear Interpolation (BLI) chip for zoom operations, a Field Programmable Gate Array (FPGA) for initial image filtering and enhancement, and a Geometric Arithmetic Parallel Processor (GAPP) processor for performing the algorithm of the invention. The processor module can alternately be implemented with a general purpose microprocessor (e.g., a general purpose microprocessor from Intel, Motorola, or AMD). The FPGA is preferably a Virtex Series FPGA from Xilinx that can have from, for example, one million to three million gates per FPGA, or an equivalent device with the same or more gates.
The GAPP processor is a fine-grained, massively parallel, two dimensional mesh computer that is uniquely efficient for two dimensional video processing applications. The preferred embodiment of the invention employs a massively parallel super-computer organized in a two-dimensional Single Instruction Multiple Data (SIMD) architecture. Effectively, this is a collection of thousands of Reduced Instruction Set Computer (RISC) type computers operating in unison. The computers, called Processing Elements (PE's), are arranged in a two dimensional grid—each PE linked to the four PE's closest to it in the grid. Each PE has its own data memory, and all PE's run the same program simultaneously. For example, there may be 1024 PE's on each chip, arranged in a grid 32 PE's wide by 32 PE's high. Running at a clock speed of 90 MHz, each chip can execute over 90 billion operations per second (BOPS). Furthermore, the architecture is fully scalable—the chips can be combined in two-dimensional arrays to build computers with over 1 million PE's, yielding computing performance measured in trillions of operations per second (TeraOPs). While capable of enormous processing power, computers built to the SIMD architecture are highly specialized in function. SIMD works well on problems that require large amounts of data to be processed in exactly the same way. GAPP is therefore ideally suited to perform the digital image processing tasks of the present invention. The preferred GAPP units are those available from Teranex Inc.
FIG. 2 illustrates the preferred method 20 of the invention. An input image 22 (e.g., FLIR or an NTSC format image) is passed to a zoom operation 24 (e.g., one done by Bi-Linear Interpolation (BLI); rotation may optionally be performed). The zoomed image is then passed to image enhancement and/or filtering 26 (preferably performed by FPGA) as well as to the image blending routine 28 of the invention (preferably performed by GAPP or, alternatively, FPGA). A reference image 30 is passed to the image blending routine and to image enhancement and/or filtering 32 (preferably performed by FPGA). Routines 26 and 32 pass their output to an image correlation and alignment routine 34 (preferably performed by GAPP or, alternatively, FPGA), which passes its resulting image to the image blending routine, which generates an updated reference image.
GAPP is preferred for image blending for the following reasons:
The alignment computation for image blending is based on correlation:
Metric( m,n )=Σ i=0,i−1 Σ j=0,J−1 |Reference( i,j )−Input( i+m,j+n )|.
The base XR algorithm compares a single reference image to the current input frame. The present invention utilizes a unique reference image centered about every pixel in the image and a unique “metric image” is computed for each pixel as well. This is a formidable task to implement in FPGA; however, GAPP is admirably suited.
With GAPP, each zoomed, filtered input pixel can be assigned to a single processor cell. By shifting either the input image or the reference image by some known amount, one can align the two images for analysis. One then computes the absolute difference at each location, then performs the local box summation to compute one element of the correlation metric surface for each cell in the array. One can then retain that result and compare it to subsequent results, which one gets by repeating the process with different alignments. Pseudo-code for this preferred method is next supplied.
/*** How to Simultaneously Compute motion vector at all locations ***/
for( x_off = x_left ; x_off < x_right ; ++x_off )
{
for( y_off = y_top ; y_off < y_bottom ; ++y_off ) {
ShiftImage( ZoomedInputImage, ShiftedInput, x_off, y_off ); Subtract( ShiftedInput, ReferenceImage, temp ); AbsValue( temp, temp ); BoxSum( temp, temp, RefSizeX, RefSizeY ); CmpLE( temp, BestMetricValue, MaxFlag );
/*** if MaxFlag is TRUE, BestMetricValue replaces RunnerUp ***/ Fork( RunnerUp, BestMetricValue, MaxFlag, RunnerUp ); Fork( PixelValue2, PixelValue1, MaxFlag, PixelValue2 );
Fork( VectorX_R2, VectorX, MaxFlag, VectorX_R2 ); Fork( VectorY_R2, VectorY, MaxFlag, VectorY_R2 );
/*** if MaxFlag is TRUE, temp replaces BestMetricValue ***/ Fork( BestMetricValue, temp, MaxFlag, BestMetricValue ); Fork( PixelValue1, ShiftedInput, MaxFlag, PixelValue1 );
Fork( VectorX, x_off, MaxFlag, VectorX ); Fork( VectorY, y_off, MaxFlag, VectorY );
}
}
ShiftImage( input, output, x, y ): shifts input image by x columns and y rows.
Requires 1 + sizeof( input ) = 17 clock cycles.
Subtract( a, b, c ): c(i,j) = a(i,j)−b(i,j)
Requires 2+ sizeof(MAX( a, b )) = 18 clock cycles.
AbsValue( input, output ): output(i,j) = | input(i,j) |
Requires 2 + sizeof( input ) = 17 clock cycles.
BoxSum( input, output, size_x, size_y ): computes the area summation over a box of size specified by size_x and size_y dimensions. Requires 2 + sizeof(input) clock cycles per add, so a 16×16 reference would require 8 add operations which would total 8*[2+16]=144 clock cycles.
CmpLE( A, B, C ): C(i,j) = (A(i,j) <= B(i,j))
Requires 2 + sizeof( MAX(A,B) )=18 clock cycles.
Fork( A, B, S, C ): C(i,j) = (A(i,j)* /S (i,j)) + (B(i,j)* S (i,j) )
Requires 2 + sizeof( MAX(A,B) ) = 18 clock cycles. 8 of these are preferred, resulting in use of 144 clock cycles.
Total cycles = 358 clock cycles per search area pixel.
At a clock speed of 133 MHz (150 MHz or faster chips are also presently available), this results in a 2.69 μS per pixel of search area. A 32×32 search area requires 2.76 μS total processing time, while a 16×16 search area requires 689 μS total processing time
The present invention can also be implemented within an FPGA, which has the advantage that hardware engineers are more familiar with FPGA interfacing issues but which has the disadvantages that FPGA is not as flexible as GAPP and it would be utilized to nearly its total capacity.
With the present invention, local motion estimation may become distracted by external detail at the target's perimeter. In cases where uniform group motion occurs, one large central correlation calculation may provide a better motion estimation for the entire grouping. This can be overcome by adding additional logic that responds when poor correlation occurs and falls back to prior art XR for those affected pixels.
A system according to the present invention preferably can improve image fidelity in at least three different ways:
Mode 1—The invention can perform the identical functionality of the base XR algorithm. As a bonus, it has at least enough processing capability to support at least four concurrent base XR processes.
Mode 2—The invention can perform per-pixel reference stabilized XR which offers the operator a stabilized picture while producing the best possible picture. This helps with multiple moving targets going in different directions; however, the algorithm would attempt to force successive frames back into their original position which can be very misleading.
Mode 3—The invention performs per-pixel input stabilized XR, which offers the operator the highest fidelity live video, using previous imagery to improve the image detail without distorting the motion within the scene. Multiple moving targets are enhanced to facilitate detection and recognition.
As may now be understood by the reader, the present invention provides the following advantages:
The invention gives the operator a wide view, and so is useful for detecting threats and objects of interest. The base XR algorithm can only enhance objects that have already been detected and tracked. Therefore, with the invention the operator gains a huge advantage in being the first to detect his/her opponent.
The invention attempts to enhance all regions of the imagery, not just the target. This allows the operator to notice additional threats while currently tracking a known threat. The base XR algorithm gives the operator a great picture of the object of interest, but it locks him/her into a “tunnel vision” image where he/she cannot see new threats.
The invention is less sensitive to target rotation, size variation, and changes in viewing angle. The invention is far better suited for fixed wing applications than would be the prior art XR algorithm.
With this invention, the operator can choose between the traditional reference stabilized view as well as an input stabilized mode. This input stabilized mode shows the live motion as it happens, only with enhanced detail derived from previous frames.
As previously noted, EO sensor performance can often be limited in resolution by stabilization performance in high contrast conditions. Sensitivity, as can be represented, for example, by a signal-to-noise ratio (SNR) measure, also can limit performance in low contrast conditions. Thus, extended range image processing in accordance with the present invention can overcome limitations associated with conventional systems and significantly increase the effective performance range of an associated EO system. Additional effective range capabilities provide higher probability of target/object recognition and identification which can, for example, enhance the battlefield survivability of a military aircraft equipped with a system in accordance with the present invention, and reduce the risk of casualties due to friendly fire. Additional range provided in accordance with the present invention can also provide an increased margin of recognition and identification in poorer atmospheric conditions.
To reiterate, the base XR algorithm utilizes a single reference image and produces a motion vector for relating the current input video to that reference image. The base XR algorithm then attempts to align the zoomed up input image to a reference image. It determines the best alignment, and then blends the zoomed input image into the reference image, assuming a satisfactory correlation is declared. This provides a disadvantage for all pixels that do not happen to align optimally with the average motion of the region of interest.
The present invention allows one to operate in three unique modes. First, the hardware required to perform this algorithm enhancement is still fully capable of performing the base XR as presently known. This mode still has one motion vector for the whole field of view, which still results in smearing of detail outside of the target region of interest.
The present invention offers two additional modes: reference stabilized and input stabilized. In the reference stabilized mode, one maintains a reference image by lag filtering in shifted input pixels to improve the reference image just as the base XR algorithm does. A difference between the two approaches is that one aligns each reference pixel with the best match in the input image on an individual pixel basis. If the target is rotating or one is rotating about it, the pixels have a better chance of not being smeared because the motion vector for each pixel is allowed to deviate from the average motion vector of the whole target. Additionally, if there were a number of targets all moving within the field of view, those targets would also be enhanced whereas the base XR algorithm would totally distort any target that was not moving in unison with the target of interest
In the third mode, one attempts to enhance the input image at all times via a “transparent” XR algorithm. This tries to align the best match within the reference image to the current input image. This avoids the stabilization effect that one currently gets from the prior art XR algorithm, which can mislead the observer into thinking that the object of interest is stationary. In this mode, the sensor image looks just like it does without XR, only the resolution and image fidelity is much higher. This is ideal for surveillance operations where the operator just wants to look out at the scene and does not want to track any objects. Multiple targets all moving in different directions can be enhanced without the operator worrying about whether he/she was being fooled into thinking that a moving object was not really moving. In this mode, the user would not even realize that any form of image enhancement was running. Instead, he/she would simply think the picture was much clearer than is usual.
The present invention is useful in numerous commercial applications such as:
(1) Security/surveillance systems—improve video resolution of live or previously recorded video.
(2) Police, Fire/Rescue—can provide much sharper picture for helicopter based search and/or tracking applications.
(3) Motion Picture Restoration—can be used to extract lost detail while averaging out Gaussian noise.
(4) Television Broadcast—can provide improved image detail to most any video signal that has consistent distinguishable detail.
(5) Television Receivers—can be used to provide improved picture sharpness as well as 2×, 4×, and even higher electronic zoom features while bringing out detail (without this algorithm, electronic zoom would either appear blocky or blurry).
(6) Home Video Enthusiasts—can improve the image fidelity for people who wish to transfer their home movies from VHS to DVD.
Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference. | A method and Electro-Optical (EO) system for processing imagery comprising selecting a first frame of data as a template frame; capturing a second frame of data using the EO system, for a plurality of pixels of the second frame, correlating the plurality of pixels of the second frame with pixels of the template frame to generate a plurality of shift vectors, one for each pixel of the plurality of pixels of the second frame, registering the second frame with the template frame by interpolating the second frame using the plurality of shift vectors and re-sampling at least a portion of the second frame to produce a registered frame, re-sampling the template frame, and combining the re-sampled template frame and the registered frame to generate an averaged frame. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to provisional application 61/138,060, filed Dec. 16, 2008.
FIELD OF THE INVENTION
This invention relates in general to well pumps, and in particular to a well pump housing varying geometry to increase heat transfer.
BACKGROUND
Referring to FIG. 1 , a well contains a casing 10 . The casing 10 lines a wellbore (not shown) and is cemented in place. A pump 12 is located inside the casing 10 , frequently at great depths below the surface of the earth. The pump is used to pump production fluid from the depths of the well up to the surface. A shaft (not shown) connects pump 12 to motor 16 . Production fluid enters the pump inlet 17 and is pumped out through tubing 18 .
The motor tends to produce heat that must be removed to prolong the life of the motor. External devices used to decrease heat create additional costs. External cooling devices, for example, use a coolant pump above the well and coolant lines running through the wellbore to the pump. These cooling devices cool the pump by circulating the coolant through the pump and transferring the coolant back to the surface. The coolant pump, coolant lines, and coolant all create additional costs. Furthermore, the coolant lines may interfere with well operations.
The motor-pump assembly is located inside a wellbore so it is desirable to transfer heat to the production fluid that is flowing past the motor. It is common to arrange the pump and motor such that the production fluid flows past the motor on its way to the pump. Heat is transferred to the production fluid and carried away as the production fluid moves to the surface. It is desirable to increase the rate of heat transfer from the motor to the production fluid.
One method to increase the rate of heat transfer is to increase the surface area of the pump that is in contact with the production fluid. This can be done by elongating the motor housing or attaching a shroud to the pump or motor. The production fluid flows between the motor and the shroud so that heat can move from both the motor and the shroud into the production fluid. Other devices, such as fins, may be used to increase surface area of the motor. All of these methods of increasing surface area are limited by the small space available inside the wellbore. Furthermore, there is a problem with fins breaking off and creating blockages within the production fluid flow.
Fins may be used to create vortices within the production fluid. The vortices in the production fluid increase the rate of heat transfer between the motor and the production fluid. Unfortunately, the vortice-inducing fins, like fins used to increase the surface area, can break off and obstruct fluid flow. Fins also make pump manufacture and maintenance more difficult because they interfere with the assembly, disassembly, and the movement within the wellbore of the pump assembly.
Assembly is more difficult because the fins must be installed on the motor before the motor is inserted into the cylindrical shroud. The difficulty arises because the fins tend to interfere with the fit between the motor and the shroud. The height of the fins must be limited to allow for insertion, but even with a limited height they can still catch on other fins, the sides of the motor, or the wellbore. If the fin is attached to the motor, for example, there must be a gap between the outer edge of the fin and the shroud to allow clearance during assembly. Clearance issues also make it extremely difficult to attach fins to both the motor and the shroud in the same assembly because the fins interfere with each other during assembly and disassembly. Furthermore, fin clearance issues prevent the fin from spanning the entire gap between the shroud and the motor.
It is also difficult to perform maintenance on the motor when fins are attached directly to the motor housing because the fins make it more difficult to put the motor on a flat surface or hold it in a vice. In addition to increased assembly and maintenance costs, there is a cost associated with manufacturing and attaching the fins to the shroud and pump. It is desirable to increase the rate of heat transfer without incurring the disadvantages of fins.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of prior art pump assembly in a wellbore.
FIG. 2 is a sectional view of the pump assembly of FIG. 1 with a shroud having an irregular-shaped side wall.
FIG. 3 is a sectional view of a pump assembly with a “stair-step” shroud attached.
FIG. 4 is a sectional view of a pump assembly with dimples on the shroud.
FIG. 5 is a sectional view of a pump assembly with dimples on the pump motor housing.
FIG. 6 is a sectional view of a pump assembly with a wire coil attached to the inside of the shroud.
FIG. 7 is a sectional view of a pump assembly with a wire coil attached to the motor housing.
FIG. 8 is a sectional view of a pump assembly and shroud with screws protruding from the inside of the shroud.
FIG. 9 is an orthogonal view of a clamshell shroud in which two halves of the clamshell are shown in the closed position.
FIG. 10 is an orthogonal view of one half of a two-part clamshell shroud and pins in the clamshell.
FIG. 11 is an orthogonal view of one half of a two-part clamshell shroud with fins.
DETAILED DESCRIPTION
Referring to FIG. 1 , the casing 10 is shown in a vertical orientation, but it could be inclined. A pump 12 is suspended inside casing 10 and is used to pump fluid up from the well. The pump 12 may be centrifugal or any other type of pump and may have an oil-water separator or a gas separator. The pump 12 is driven by a shaft (not shown), operably connected to a motor 16 . A seal section 14 is mounted between the motor 16 and pump 21 . The seal section reduces a pressure differential between lubricant in the motor and well fluid. The motor 16 is encased in a housing 19 . Preferably, the fluid produced by the well (“production fluid”) flows past the motor 16 , enters an intake 17 of pump 12 , and is pumped up through a tubing 18 . Preferably, the motor 16 is located below the pump 12 in the wellbore. The production fluid may enter the pump 12 at a point above the motor 16 , such that the fluid is drawn up, past the motor housing 19 of the motor 16 , and into the pump inlet 17 .
The rate of heat transfer is determined by the equation Q=h(A)(T); where Q=rate of heat transfer, h=the heat transfer coefficient, A=surface area, and T=the difference in temperature (in this case, T is the difference in temperature between the motor housing 19 and the production fluid).
Referring to FIG. 2 , a shroud 22 is mounted around motor 16 to increase the velocity of fluid flowing past the motor housing 19 . The shroud 22 has an open lower end 24 and an upper end 26 sealingly secured around pump 12 above intake 17 . The shroud 22 may be secured by other means and in other locations. The shroud 22 reduces the cross sectional area of the path of fluid flow and thus increases velocity. Increased velocity, or changing velocity, or both, will generally increase turbulence, which in turn increases the heat transfer coefficient (h) of the production fluid flow across the surface of the motor housing 19 . A device that increases turbulence in the fluid flow is referred to herein as a “turbulator.”
A turbulator may be a feature on a shroud, on the motor housing, or any other part of the motor. As shown in FIG. 2 , the turbulator comprises shroud 22 , which may have an irregular sidewall 28 shape, and thus creates pockets of increased velocity and turbulence as the production fluid flows within shroud 22 . In FIG. 2 , the sidewall 28 of the shroud 22 is formed into a pattern that is sinusoidal when viewed in cross section. The period of each rounded peak and valley may vary considerably. For example, the length of each curve could be much shorter than the length of the motor. The annular flow area varies along the length of the motor 16 as a result.
Referring to FIG. 3 , turbulence is increased by using a “stair-step” shaped shroud 23 as the turbulator. The production fluid develops a higher velocity, and thus more turbulence, as the inner diameter (“ID”) of the shroud 23 decreases. The laminar flow is further disrupted as the fluid flows past the corners 30 of the indentations in the shroud 23 . In one example embodiment, the motor housing 19 has a 7.25″ diameter and the shroud 22 has a 10.75″ diameter, leaving a 1.75″ maximum gap between the motor housing 19 and the shroud 23 . The shroud 23 could constrict to allow, for example, a 0.5″ clearance between the motor housing 19 and shroud 23 , thus increasing the velocity. The steps of the shroud 23 may be various lengths measured in the direction of the shroud 23 axis, including, for example, 0.5″ or 1″. For example, section 30 a has a smaller inner diameter and shorter axial length than section 30 b . Steps also could have a uniform, corrugated appearance such that, for example, every other step has the same inner diameter.
Another embodiment of the stair-step shroud 23 is an asymmetrical stair step (not shown) in which the inner diameter varies in one or more quadrants of the shroud 23 . This asymmetrical shape further disrupts laminar flow by creating pockets of higher and lower pressure from side-to-side across the motor housing 19 thus promoting lateral flow of the production fluid.
Referring to FIG. 4 , the turbulator comprises multiple dimples 32 on the shroud 25 . The dimples 32 are indentations or protrusions in the interior face of the shroud 25 . The size of the indentations 32 may vary and could be, for example, made from a ¼″ or ½″ diameter round punch driven to a ⅛″ depth. Dimples 32 could also have a significantly larger or smaller diameter and be driven to a greater or lesser depth. Furthermore, the dimples 32 may have different shapes such as round, oval, square, and the like. The dimples 32 may be distributed about the surface in a symmetric pattern or they may be placed randomly. The dimples 32 may be concave or convex in relation to the interior of the shroud 25 . The dimples 32 increase the turbulence of the production fluid and thus increase the rate of heat transfer from the motor housing 19 to the production fluid. The dimples give the shroud a textured surface. Other kinds of textured surfaces may also be used to increase turbulence. Furthermore, the dimples 32 are an inexpensive design modification and are not detrimental to the maintenance, handling, and installation of the motor 16 . The dimples 32 may be used alone or in combination with other devices that increase production fluid turbulence.
Referring to FIG. 5 , the turbulator comprises multiple dimples 33 on the motor housing 16 . The dimples 33 are indentations or protrusions in the exterior surface of the motor housing 27 . The size of the indentations 33 may vary and could be, for example, made from a ¼″ or ½″ diameter round punch driven to a ⅛″ depth. Dimples 33 could also have a significantly larger or smaller diameter and be driven to a greater or lesser depth. Furthermore, the dimples 33 may have different shapes such as round, oval, square, and the like. The dimples 33 may be distributed about the surface in a symmetric pattern or they may be placed randomly. The dimples 33 may be concave or convex in relation to the exterior of the motor housing 27 and may be used regardless of whether a shroud is used. The dimples 33 increase the turbulence of the production fluid and thus increase the rate of heat transfer from the motor housing 27 to the production fluid. The dimples give the housing a textured surface. Other kinds of textured surfaces may also be used to increase turbulence. Furthermore, the dimples 33 are an inexpensive design modification and are not detrimental to the maintenance, handling, and installation of the motor 16 . The dimples 33 may be used alone or in combination with other devices that increase production fluid turbulence.
Referring to FIG. 6 , a wire coil 34 may be attached to the inside of a shroud 35 to form a turbulator. The presence of the helical coil 34 serves to disrupt the laminar flow of the production fluid and thus increase the rate of heat transfer. The coil 34 can be installed in any variety of positions. For example, it could be attached to the shroud 35 in one or more places as it loops around the motor housing 19 , or it could use spacers to hold the wire in the gap between the motor housing 19 and the shroud 35 . In other embodiments, more than one wire could be attached to the inside of the shroud 35 . The wire may have, for example, twists or coils to further disrupt laminar flow. In still other embodiments, the wire may be attached in two places near the inlet such that the wire forms a “horseshoe” shape inside the shroud. The wire may be used by itself or in conjunction with other means of flow disruption such as dimples 32 ( FIG. 4 ) or irregularly shaped shrouds.
Referring to FIG. 7 , the turbulator may be a wire coil 37 attached in helical fashion to the outside surface of the motor 39 . The presence of the coil 37 serves to disrupt the laminar flow of the production fluid and thus increase the rate of heat transfer. The coil 37 can be installed in any variety of positions. For example, it could be looped around the motor 16 and attached directly to the motor housing 39 , or it could use spacers to hold the wire at a distance from the motor housing 39 . The wire may have, for example, twists or coils to further disrupt laminar flow. The wire may be used by itself without a shroud, or in conjunction with other means of flow disruption such as dimples 33 ( FIG. 5 ) or irregularly shaped shrouds.
Referring to FIG. 8 , the turbulator comprises pins or screws 36 attached to the shroud 41 and extending radially inward to disrupt flow. The pins 36 may be, for example, ¼″ diameter studs that could be installed by inserting them through holes drilled shroud 41 such that they protrude from the interior of the shroud 41 . In other embodiments, screws 36 or bolts could be installed by screwing them through threaded holes tapped in the shroud 41 . The pins or screws 36 may be held in place by a variety of means, including, for example, their own threads, bolts, welding, and the like. The pins or screws 36 may be distributed around the entire circumference and along the entire length of the shroud 41 . The pins or screws 36 may be arranged in a symmetrical or in a random pattern. Furthermore, the pins or screws 36 may be used to disrupt flow in straight cylindrical shrouds or in irregularly shaped shrouds, as shown in FIGS. 2 and 3 .
The pins or screws 36 serve to disrupt the laminar flow of the production fluid and thus increase the rate of heat transfer. In a preferred embodiment, the pins or screws 36 are inserted to a depth such that they contact or nearly contact the motor housing 19 . By contacting or nearly contacting the motor housing 19 , the pins or screws 36 create turbulence close to the motor and thus increase the rate of heat transfer. The user may insert the screws 36 or pins through the shroud 41 after the motor 16 is already installed in the shroud 41 . This embodiment allows easy insertion of the motor 16 , followed by installation of screws 36 that nearly contact the motor and the shroud 41 . The screws 36 may be removed prior to removal of the motor 16 from the shroud 41 , thus providing the heat transfer benefits of the screws 36 while still allowing for easy maintenance access. The pins or screws 36 may be used in combination with any other embodiment of invention, including irregularly shaped shrouds and dimples 32 .
Referring to FIG. 9 , the shroud 44 may be split into two or more halves or pieces 46 that may be joined together around the motor 16 in a “clamshell” configuration. The joint 48 may be any variety of joint types, including flange, tongue-and-groove, dowel pin, and the like. The pieces 46 may be held together with bolts, quick release latches, interlocking pieces, and the like. The clamshell may divide the shroud 44 into two, three, or more segments or pieces 46 . Each piece 46 may be a segment of a cylinder. One or more joints between the components may have a hinge. The clamshell design may be used to facilitate easier installation of the turbulators.
Referring to FIG. 10 , the clamshell shroud 44 overcomes the difficulty, for example, of installing and removing the motor 16 when other devices, such as pins 50 , screws, fins 52 , and the like are present between the motor and shroud 44 . Separating the clamshell segments facilitates installation of objects located between the shroud 44 and the motor 16 by giving better access to the inside surface of the shroud 44 . Furthermore, it is easier to manufacture irregularly shaped shrouds when the shroud 44 is split. It is easier, for example, because the pieces can be produced by metal-stamping rather than requiring extrusion, turning, or otherwise shaping a cylindrical object.
Referring to FIG. 11 , in one embodiment of the clamshell configuration, fins 52 may be installed on the motor housing 19 or the shroud 54 , and the fins 52 may be so long in radial dimensions that they contact both components. A fin 52 could, for example, be welded to the shroud 54 and contact or nearly contact the motor housing 19 when the motor 16 is installed. This embodiment overcomes the inherent manufacturing and maintenance difficulties associated with attaching fins 52 directly to the motor housing 19 , yet still creates turbulent flow immediately adjacent to the motor.
The fins 52 may be oriented in a variety of positions. In one embodiment, the fins 52 are attached at a 90 degree angle or normal in relation to the wall of the shroud 54 . Fins 52 may be slanted in relation to the axis of the shroud 54 , such as at a 45 degree angle. As illustrated by group 56 of fins 52 , adjacent fins 52 may incline at the same inclination relative to the axis of shroud 54 . Also, some of the adjacent fins 52 may slant at alternating angles to each other. For example, one fin 52 is slanted at a 45 degree angle in one direction, and the adjacent fin is slanted at an opposing 45 degree angle in the opposite direction, such that the bottom most edges 58 of the fins 52 are nearest each other and the fins diverge as they go up along the axis of the shroud. Other fins 52 may have the same 90 degree opposed orientation, but with the top most part 60 of the fins 52 nearest each other. The angle between opposed sets of fins 58 could be any angle. The fins 52 may be set at any variety of angles, and the fins need not be uniform in layout or in angles. In some embodiments, the fins join shroud 54 at an angle other than 90 degrees or normal relative to the surface of the shroud.
The various fin 52 configurations serve to disrupt the laminar flow of the production fluid as it flows past the motor housing 19 and shroud 54 . In some embodiments, the flow develops swirling or vortexes. The fins 52 may be various lengths, including, for example, 1 to 3 inches long. The fins 52 may be attached to the clamshell shroud 54 by, for example, welding or adhesives before the halves of the clamshell 54 are joined.
While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention. | The motor of an electrical submersible pump generates a significant amount of heat that can be removed by transferring it to the well production fluid. The motor housing may have turbulators that increase the turbulence of the production fluid to increase the rate of heat transfer. The turbulators are designed for manufacturability and maintenance. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The invention relates to a process for manufacturing a flat gasket, and particularly a cylinder head gasket for a combustion engine.
[0003] 2. Related Art
[0004] If an elastomer gasket is required to seal against media such as water or oil, for example in a cylinder head gasket for a combustion engine, certain prerequisites apply to the surfaces to be sealed and to the space required. Two basic possibilities are available in this concept:
[0005] Individual gaskets against oil/water. This type of gasket usually has a larger surface area requirement, especially in connection with the gas seal required in the area of the combustion chamber.
[0006] The other type of gasket would be a circulating gasket for at least one medium, with a separate gasket for the other medium. This pushes against the limits of current solutions.
[0007] So-called ‘On Top Molding’ is generally known and used for sealing of fluid media. A circulating gasket would be possible in this case. This technology requires the use of stopper devices to limit the deformation of the elastomeric bond; to protect the elastomer against destruction. These stoppers are built up of lugs which are supplementally attached to the carrier, and which essentially serve only this function. Also, an additional sealing by means of a discrete element or supplemental lugs on the carrier frame is needed, in conjunction with the necessary gas seal in the combustion chamber area of the motor. The carrier frame alone cannot be used as a gas seal without additional design elements.
[0008] One other possibility is so-called “edge molding”, where the edges of the metal carrier frame are sprayed with elastomer for sealing use. With edge molding, the gasket is limited at this time to individual openings. A circulating gasket, combined with a half or full bead in certain lugs is not possible at this time. The typical edge molding, using a free circulating elastomer lip, would be too weak against the relative movements that occur in cylinder head gaskets in a combustion engine, and would immediately be destroyed.
[0009] DE-A 40 10 991 discloses a metallic flat gasket, specifically, a cylinder head gasket, with insert ring seals made of metallic-reinforced soft cloth material on the outer surface and having radial protruding ledges inserted into at least one of the duct channels. The ledges are formed by the metallic reinforcing rings. Indentations are stamped into the edge area of the duct channel, corresponding to the ledges of the insertion ring seals. The insertion ring seals are secured against falling out of position by bending and folding of the cavity edge over them.
[0010] U.S. Pat. No. 5,267,740 discloses a metal cylinder head gasket with integrated sealing features. Partially interleaving channels are punched in to the channels to guide the flow of media through duct channel openings so that connecting areas arise between the carrier frame and the supports. The supports are equipped with a sealing profile extending beyond their own edge, and beyond the edge of the carrier frame material.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0011] The invention provides a process to meet the requirements of an ever smaller space for the gasket while simultaneously providing for a low cost, and a concurrently providing a simple method flat gasket, especially a cylinder head gasket for a combustion engine.
[0012] According to one aspect of the invention, the process involves the manufacture of a flat gasket, specifically a cylinder head gasket for a combustion engine, where at least one metallic carrier material, at least one internal and at least one external metal part having a predefined contour can be separated out, such that the form of the contours, when the pieces are placed together into each other, forms a gap, resulting in at least one sealed area filled with elastomer material.
[0013] According to another aspect of the invention, a flat gasket is provided, specifically a cylinder head gasket for a combustion engine, including at least two metal parts having predefined contours, arranged on one level, creating a gap when the pieces are placed together into each other, having at least one sealed area filled with elastomer material.
[0014] According to a further aspect of the invention, the at least two metal parts are stamped simultaneously from the same carrier material and the elastomer material is sprayed into the gap between the parts.
[0015] According to a further aspect of the invention, the elastomer material is sprayed simultaneously on both sides of the metal parts, such that an encapsulated profile is formed. This elastomer profile runs completely around for sealing of a medium, and advantageously encircles other media which must also be sealed into the internal area. The advantage of the use of metal parts from the same carrier metal is based on the premise that varying sheet metal thicknesses can be avoided.
[0016] According to a further aspect of the invention, the at least two parts include an internal metal part and or external metal part. The internal metal part can additionally serve as an individual gasket to seal other small holes via edge molding, and thereby seal up at least a second medium. If the flat gasket is a cylinder head gasket, then the combustion chamber duct channels can be foreseen in the inner metal parts, and be equipped with a stamped bead.
[0017] According to a further aspect of the invention, the deformation of the elastomer material is limited by the metal parts placed together into each other in the one level.
[0018] In this simple way, a single layer metallic flat gasket, especially a cylinder head gasket, can be advantageously manufactured. The use of thick sheet metal design with edge molding can provide a relatively significant savings as compared to the more complicated on-top molding. As a result of the encapsulated edge molding, the elastomer material is less sensitive to relative motion and is held in position.
[0019] Compared to the state of the art, a reduction in the space needed for an individual seal, and between a gas seal and, for example, water and oil media, is realized with the encircling seal compared to the individual seal.
THE DRAWINGS
[0020] These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appended drawings, wherein:
[0021] FIG. 1 is a fragmentary top view looking down onto a cylinder head gasket as per the invention; and
[0022] FIG. 2 is a fragmentary cross-sectional view of the gasket of FIG. 1 .
DETAILED DESCRIPTION
[0023] FIG. 1 depicts a cylinder head gasket 1 for a combustion engine (not shown). The cylinder head gasket 1 includes an internally mounted metal part 2 and an externally attached metal part 3 , which may be stamped out of the same material, forming a gap therebetween.
[0024] The matching contours of the metal parts 2 , 3 are to be fitted into the same geometric profile of the individual combustion engines in a corresponding manner. In this example, beginning from the adjusting edge, elastomer material 4 is to be sprayed into the gap a formed by the circulating channel. The elastomer material 4 thereby forms a circulating (i.e., circumferentially continuous) sealed area where the distortion of the elastomer material 4 is limited by the single layer cylinder head gasket 1 , made of the metal parts 2 , 3 . The internal metal part 2 is equipped with at least one combustion chamber duct channel opening 5 , that is stamped out at the same time as the production of metal parts 2 , 3 . There may be formed a plurality of such openings 5 , and at each combustion chamber duct channel opening, at least one bead 6 is stamped in to surround the opening 5 . In like manner, holes 7 may be stamped into internal and external metal parts 2 , 3 , which may serve different purposes; for example, as bolt holes for mounting of the cylinder head gasket 1 . Further, the shaping of the metal parts 2 , 3 may be carried out in such a way that recesses facing each other 8 , 9 are formed, and are then generated in the same run of elastomer material 4 with the media flow through channels 10 being formed in the elastomer in the vicinity of the recesses 8 , 9 . Additional media flow through holes 11 may be formed in the internal metal part 2 and covered with elastomer material 12 by edge molding.
[0025] FIG. 2 shows a schematic fragmentary cross section of the cylinder head gasket 1 installed as per FIG. 1 . Cylinder head 13 and cylinder block 14 are shown. Using reference mark 15 , 16 the constructed areas of the cylinder block for guiding the flow of oil 15 and water 16 are indicated. One can also make out a portion of the internal metal part 2 , and a portion of external metal part 3 . The elastomer material 4 running around the area forms a first sealed area, whereby the protruding profile 19 , 20 of the frontal surface 17 , 18 on metal parts 2 , 3 is sprayed. In assembling the cylinder head gasket 1 , specifically when cylinder head 13 is placed onto cylinder block 14 , and is firmly attached by parts which are not depicted herein, the elastomer material of the profile bodies 19 , 20 can move expansively into the free spaces 21 , 22 preformed or shaped into the elastomer material 4 . The distortion of the elastomer material 4 is limited solely by the thickness of metal parts 2 , 3 .
[0026] The metal parts 2 , 3 can be equipped with additional saved areas of adjoining spaces 8 ′, 9 ′, as the need arises. These regions may be spaced at larger distances between each other than regions 8 , 9 , and can accept individual insert metal parts 23 , that have been attached with internal metal parts 2 and/or external metal parts 3 , in the course of the spraying process of the elastomer material 4 . | A flat metal gasket includes exterior and interior metal gasket parts formed with a gap therebetween and in which elastomeric material is introduced to bridge the parts and form a seal therebetween. The elastomeric material can be formed with one or more media flow openings. | 5 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to ultrasound devices and, more particularly, to a method and apparatus that enables battery packs of different sizes to be used with an ultrasound device.
BACKGROUND OF THE INVENTION
An ongoing effort is being made by manufacturers of medical ultrasound imaging systems to make them small and portable so that clinicians can easily carry them to the patient location. This is viewed in the ultrasound industry as a superior alternative in many situations to the conventional approach of having a large, expensive and immobile ultrasound system located in an examination room.
Currently, portable ultrasound systems are available that are capable of being powered by a battery pack that is attached by some mechanism to the ultrasound device. For example, SonoSite, Inc. of Bothell, Wash. provides a small, battery-powered, portable medical ultrasound imaging system that is powered by a rechargeable 3.0 ampere hour battery that is located inside the ultrasound system and that is easily removable. The ultrasound system can operate for 1.5 to 4 hours on a charged battery. The battery is designed to be removable so that a discharged battery can be removed and a fully charged battery can be installed. The ultrasound system can then be used while the discharged battery is being recharged.
One of the disadvantages of this type of solution is that, because the battery packs are installed either in a compartment within the ultrasound system or within a recessed region of the ultrasound system, a larger battery pack or a battery pack having a slightly different form factor cannot be used with the ultrasound system. In other words, the physical structure of the ultrasound system, or at least the mechanisms for securing the battery pack to the ultrasound system, would have to be altered to accommodate the change in the battery pack.
Accordingly, a need exists for a method and apparatus that would enable battery packs of different sizes and/or that have different form factors to be used with an ultrasound device without having to change the physical structure of the ultrasound device to accommodate the change in the battery pack and without having to change the mechanism for securing the battery pack to the ultrasound device.
SUMMARY OF THE INVENTION
A method and apparatus for enabling battery packs of different sizes to be used with an ultrasound device. The apparatus of the present invention comprises an ultrasound device having a battery pack installment apparatus configured to be capable of being coupled with battery packs of different sizes. The method comprises the step of providing the ultrasound device with a battery pack installment apparatus that is configured to couple with battery packs of different sizes.
These and other features and advantages of the present invention will become apparent from the following description, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial representation of an ultrasound device that can be used with a battery pack of various sizes and/or form factors in accordance with one example embodiment without having to change the physical structure of the ultrasound device or the mechanism for securing the battery pack to the ultrasound device to accommodate a change in the size and/or form factor of the battery pack.
FIG. 2 is a pictorial representation of an ultrasound device that can be used with a battery pack of various sizes and/or form factors in accordance with another example embodiment without having to change the physical structure of the ultrasound device or the mechanism for securing the battery pack to the ultrasound device to accommodate a change in the size and/or form factor of the battery pack.
FIG. 3 is a pictorial representation of an ultrasound device that can be used with a battery pack of various sizes and/or form factors in accordance with another example embodiment without having to change the physical structure of the ultrasound device or the mechanism for securing the battery pack to the ultrasound device to accommodate a change in the size and/or form factor of the battery pack.
DETAILED DESCRIPTION OF THE INVENTION
The present invention enables an ultrasound device to be used with battery packs of various sizes and/or form factors without having to change the physical structure of the ultrasound device or the mechanism(s) used to secure the battery pack to the ultrasound device. Since the present invention is not limited to any particular ultrasound device design, battery pack design, or mechanisms for securing the battery packs to the ultrasound devices, three different examples that demonstrate the overall concept of the present invention and the manner in which this concept can be implemented are illustrated in FIGS. 1-3.
However, these examples are merely demonstrative of the various manners in which the concepts of the present invention can be implemented and are not intended to represent the only embodiments of the present invention. Those skilled in the art will understand, in view of the discussion provided herein, that there are an infinite number of ways in which the size of a battery pack can be made independent of the physical design of the ultrasound device with which it is used. Multiple examples of ultrasound device designs and battery pack designs, as well as the associated battery pack securing apparatus of the ultrasound device and the coupling mechanism of the battery pack, will be given to demonstrate examples of the ways that ultrasound device designs, battery pack designs, ultrasound device battery pack securing apparatus designs and battery pack coupling mechanism designs can be created or selected to achieve the goals of the invention.
FIG. 1 is a perspective, pictorial representation of an ultrasound device 1 that is portable, capable of being battery powered and that has a design that is similar to a typical laptop computer. The ultrasound device 1 has a control panel 2 , a display monitor 4 and a hinging mechanism 3 that enables the display monitor 4 to be rotated in the y-direction toward and away from the control panel 2 to open, close and adjust the positioning of the display monitor 4 . The bottom surface 10 of the ultrasound device has negative and positive contact terminals (not shown) that are positioned to be in contact with negative and positive contact terminals 8 and 9 , respectively, of a rechargeable battery pack 5 when the battery pack 5 is secured to the ultrasound device via latches 6 A and 6 B that interlock with latching receptacles 7 A and 7 B, respectively. Latching receptacle 7 B cannot be seen in the view shown in FIG. 1, but it is identical to latching receptacle 7 A. The dashed lines along the bottom surface 10 of the ultrasound device 1 represent the battery pack 5 when it is secured to the bottom surface 10 of the ultrasound device 1 .
The size of the battery pack 5 could be increased in a number of ways without having to alter the physical structure of the ultrasound device 1 and without having to alter the designs of the mechanisms 6 A, 6 B, 7 A and 7 B used to secure the battery pack 5 to the ultrasound device 1 . For example, the battery pack 5 has a thickness, T, in the z-direction and this thickness is generally proportional to the amount of time that the battery pack 5 will power the ultrasound device before having to be recharged. If the battery pack 5 were made larger by increasing its thickness, T, in the downward z-direction, the battery pack would power the ultrasound device 1 for an even longer period of time before needing to be recharged. It is apparent from FIG. 1 that the thickness of the battery pack 5 could be increased and that neither the physical structure of the ultrasound device 1 nor the design or structure of the securing mechanisms 6 A, 6 B, 7 A, and 7 B would need to be changed.
It should be noted that, rather than changing the entire thickness, T, of the battery pack 5 in the downward z-direction, the thickness T of a certain portion, or portions, of the battery pack 5 could be increased in the downward z-direction without having to change the physical structure of the ultrasound device 1 or the design or structure of the securing mechanisms 6 A, 6 B, 7 A, and 7 B to accommodate the change in the thickness of the battery pack 5 . Of course, the battery pack 5 could also be decreased in thickness without having to change the physical structure of the ultrasound device 1 or the design or structure of the securing mechanisms 6 A, 6 B, 7 A, and 7 B to accommodate the change in the thickness of the battery pack 5 .
It should also be noted that the width (y-direction) and/or length (x-direction) of the battery pack 5 could also be altered without having to change the physical structure of the ultrasound device 1 or the design or structure of the securing mechanisms 6 A, 6 B, 7 A, and 7 B to accommodate the change in the thickness of the battery pack 5 . However, in these cases, it would be necessary to ensure that the latching mechanisms 6 A and 6 B remain at their respective x, y coordinate locations so that they will remain aligned with the latching receptacles 7 A and 7 B. The securing mechanisms 6 A and 6 B correspond to one example of a suitable design for the battery pack coupling mechanism. The securing mechanisms 7 A and 7 B correspond to one example of a suitable design for the ultrasound device battery pack securing apparatus.
Practical reasons exist for wanting to be able to enable a portable ultrasound device to be capable of being equipped with battery packs of different sizes (and thus of different ampere hours). One reason is that this allows the size and weight of the ultrasound device to be tailored to the application. For example, if the ultrasound device is likely to sit in a charging cradle in a doctor's office the majority of the time and only be used intermittently for short periods of time, the battery pack size can be relatively small. On the other hand, if the ultrasound device is intended to be used by a healthcare worker doing rounds in a hospital for relatively long periods of time, it would be desirable to use a battery pack of a larger size to eliminate the need to recharge the battery during rounds. In all of these cases, an ultrasound device having a particular physical structure or design could be equipped with different size batteries depending on the manner in which the ultrasound device is going to be used.
FIG. 2 is a pictorial representation of an ultrasound device that can be used with a battery pack of various sizes and/or form factors in accordance with another example embodiment without having to change the physical structure of the ultrasound device or the mechanism for securing the battery pack to the ultrasound device to accommodate a change in the size and/or form factor of the battery pack. In this example, the ultrasound device 10 has rails 11 A and 11 B located on the bottom surface 12 of the ultrasound device 10 . A rechargeable, removable battery pack 13 has grooves 14 A and 14 B formed in the sides of the battery pack 13 that are shaped to slidably engage rails 11 A and 11 B so that the battery pack 13 can be fully inserted into the ultrasound device 10 in the y-direction. When the battery pack 13 is fully inserted into the ultrasound device 10 in the y-direction, the positive and negative electrical contacts 15 A and 15 B will be in contact with positive and negative electrical contacts (not shown) disposed on the bottom surface 12 of the ultrasound device 10 .
When the battery pack 13 is in its fully-installed position, an upwardly projecting latch 16 is received in a receptacle (not shown) located on the bottom surface 12 of the ultrasound device 10 . The interlocking of the latch 16 and the receptacle (not shown) prevents the battery pack 13 from moving in the y-directions. In order to remove the battery pack 13 , a tab 17 is pushed in the downward z-direction, thereby causing the latch 16 to move in the downward z-direction so that it is no longer engaged in the receptacle located on the bottom surface of the ultrasound device 10 . The battery pack 13 can then be removed from the ultrasound device 10 by sliding the battery pack in the rearward y-direction.
The dashed box 18 indicates how the thickness of the battery pack 13 can be increased in the downward z-direction without having to alter the physical structure or design of the ultrasound device and without having to alter the engagement/securing mechanisms 11 A, 11 B, 14 A, 14 B 16 and 17 . Of course, the battery pack could be decreased in thickness in a similar manner.
FIG. 3 is a pictorial representation of an ultrasound device that can be used with a battery pack of various sizes and/or form factors in accordance with another example embodiment without having to change the physical structure of the ultrasound device or the mechanism for securing the battery pack to the ultrasound device to accommodate a change in the size and/or form factor of the battery pack. In accordance with this embodiment, the ultrasound device 20 has a laptop computer design similar to that shown in FIG. 1 . However, in this embodiment, the rechargeable battery pack 21 is removably securable to the side 22 of the ultrasound device 20 . The battery pack 21 has clips 23 A and 23 B on it that are shaped and adapted to be engaged by receptacles 24 A and 24 B, respectively. When the clips 23 A and 23 B are engaged in the receptacles 24 A and 24 B, the battery pack 21 is rotated upwards in the z-direction and forward in the x-direction until the downward projecting walls 26 A and 26 B of the latch 25 grasp a recess in the cutaway area 27 of the battery pack 21 . The latch 25 comprises a pivot mechanism (not shown) such that pressure placed on the rear portion of the latch (i.e., the end opposite the end comprising wall 26 B) in the downward z-direction causes walls 26 A and 26 B to move in the upward z-direction. The latch 25 is spring-loaded so that it is biased to its closed position, thus preventing the battery pack 21 from being unintentionally separated from the ultrasound device 20 .
In the installed position, the positive and negative electrical contacts 28 A and 28 B on the battery pack 21 are in contact with the positive and negative electrical contacts 29 A and 29 B on the side 22 of the ultrasound device 20 . This is also the case with the designs shown in FIGS. 1 and 2. In these cases, preferably protection (not shown) is provided about each contact of the ultrasound device and about each contact of the battery pack to prevent short circuits from occurring between the contacts.
It should be noted that it is not necessary that installation result in enabling power to be supplied from the battery pack to the ultrasound device. This is true regardless of the shape and design of the battery pack and the ultrasound device with which it is used. For example, once the battery pack is installed, electrical connection between the battery pack and the ultrasound device can be accomplished in some other way, such as, for example, by connecting the battery pack to the ultrasound device via a wire and plug arrangement that enables power to be supplied from the battery pack to the ultrasound device.
The latching configuration is sufficient to maintain the battery pack 21 in its installed position until a force is applied to the rear portion of the latch 25 (i.e., the end of the latch 25 opposite the end of the latch having wall 26 B extending therefrom) in the downward z-direction. When such a force is applied, the battery pack 21 can be rotated away from the ultrasound device, thereby disengaging the clips 23 A and 23 B from the receptacles 24 A and 24 B. The dashed lines 30 mirroring the shape of the battery pack 21 are intended to indicate that the dimensions of the battery pack 21 can be increased or decreased in shape without having to change the physical structure of the ultrasound device 20 or the mechanisms 23 A, 23 B, 24 A, 24 B, 25 , 26 A, 26 B or 27 that are used to secure the battery pack 21 to the ultrasound device 20 . It should also be noted that the configuration of the side 22 of the ultrasound device 20 could alternatively be located on one of the other sides 31 , 32 or 33 of the ultrasound device 20 and that the battery pack 21 could installed on one of those sides rather than on side 22 of the ultrasound device.
It should be noted that the present invention has been described with reference to example embodiments and that the present invention is not limited these example embodiments. Multiple examples of ultrasound device designs and battery pack designs, as well as the associated battery pack securing apparatus of the ultrasound device and the coupling mechanism of the battery pack, have been given simply to demonstrate that virtually an infinite number of ultrasound device designs, battery pack designs, ultrasound device battery pack securing apparatus designs and battery pack coupling mechanism designs can be created or selected to achieve the goals of the invention. With respect to a given ultrasound device, multiple variations in the dimensions of the battery pack can be made without having to alter the physical design of the ultrasound device or the physical designs of the associated battery pack securing apparatus of the ultrasound device and the coupling mechanism of the battery pack. Therefore, those skilled in the art will understand from the discussion provided herein that there are many ways of achieving the goals of the present invention without deviating from the scope of the present invention. | A method and apparatus are provided for enabling battery packs of different sizes to be used with an ultrasound device. The apparatus of the present invention comprises an ultrasound device having a battery pack installment apparatus configured to be capable of being coupled with battery packs of different sizes. The method comprises the step of providing the ultrasound device with a battery pack installment apparatus that is configured to couple with battery packs of different sizes. | 0 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent Application, Serial No. 10 2013 108 065.0, filed 29 Jul. 2013, pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an elastomer bearing, the use of an elastomer bearing as bearing for a motor vehicle component and the production of an elastomer bearing.
[0003] The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
[0004] Elastomer bearings are used in the motor vehicle field in a broad range of applications. They serve for supporting vehicle parts such as stabilizers or control arms on subframes or on the vehicle body, where they serve for dampening vibrations or decoupling of sounds in order to provide a comfortable driving experience.
[0005] Particularly important is the rotation-proof connection of an elastomer bearing to the vehicle body or a subframe in order to ensure sufficient durability and stability of the connection and with this safety during driving. In most cases an elastomer bearing is connected with a subframe or the vehicle body via a metallic outer sleeve or bearing bracket. In order to be able to ensure a rotation-proof connection between an elastomer part and the outer sleeve, both parts are for example connected to each other by vulcanizing. A method for producing composite systems made of metal and polymer form parts is for example disclosed in WO2003/097333 A1. Here the metal parts, for example the outer bracket of a stabilizer bearing, are first provided with a bonding agent or primer, are then pressed with a polymer form part and the two parts then connected to each other by inductive heating.
[0006] A similar method is disclosed in DE 199 19 573 A1. Also in this case a metal part, which can be a bearing shell or an outer connection sleeve, is pretreated with an adhesive system. Subsequent thereto an elastomer form part is pressed under moderate pre-tension against the metal part and then the elastomer part, which up to this point is not yet completely vulcanized, is connected by full vulcanization with the metal part.
[0007] A disadvantage of these methods is that for the vulcanization an additional labor intensive step with additional tools, heating elements and the like is required, which also increases the costs due to the required energy.
[0008] It is also known from the state of the art to press an elastomer part into a metallic outer sleeve and to produce the rotation-proof arrangement by a press fit. The stability of such a press fit however is limited especially when the outer sleeve is provided with a corrosion protective layer which lowers the friction force between the elastomer part and the outer sleeve. There is therefore the risk that the elastomer part slides out of its position in case of high stress in the outer sleeve.
[0009] It would therefore be desirable and advantageous to provide an improved elastomer bearing which has a rotation-proof arrangement of its components and in addition can be easily manufactured and mounted.
SUMMARY OF THE INVENTION
[0010] According to one aspect of the present invention, an elastomer bearing includes a cylindrical inner metal part, a metallic outer sleeve arranged at a radial distance around the inner metal part; and an elastomer part arranged between the inner metal part and the metallic outer sleeve, the elastomer part having an outer sheath provided with a plastic layer, the outer sleeve being constructed as a one-piece extruded part made of lightweight metal, the outer sleeve having an inner sheath surface provided with a profiling which form fittingly engages in the plastic layer.
[0011] An elastomer bearing according to the invention has a cylindrical inner metal part a metallic outer sleeve, which is arranged at a radial distance about the inner metal part and an elastomer part, which is arranged between the inner metal part and the outer sleeve. The elastomer part has at its outer sheath surface a plastic layer. The outer sleeve is a one-piece extruded part made of light metal and has at its inner sheath surface a profiling which form fittingly engages in the plastic layer of the elastomer part.
[0012] Such elastomer bearings can be used especially in the vehicle body region of motor vehicles at many locations. For example they can serve as bearings for stabilizers wherein then a section of the stabilizer forms the cylindrical inner metal part of the bearing. These elastomer bearings are also suited for connection of camber and toes control arms, of longitudinal control arms of composite steering axles, of swing connectors or axle carriers.
[0013] The outer sleeve is made of a lightweight metal for example aluminum and is produced as cut-to-size extruded profiles. The profiling on the inner sheath surface of the outer sleeve results in a form fit with the plastic layer of the elastomer part. This form fit results in a rotation-proof fixation so that the outer sleeve and the elastomer part always have the same position relative to each other.
[0014] For the producing of the inner profiling extrusion is particularly advantageous. The inner profiling can then be formed directly during the production process of the outer sleeve and does not have to be introduced retroactively into the outer sleeve by a material removing method.
[0015] The use of aluminum or another extrudable lightweight metal is advantages for many reasons. Conventional is the use of steel shells or steel sleeves, which due to their corrosion proneness have to be provided with an additional protective layer. Such steel sleeves are made of high-strength steel in order to account for the constant stress during use in the vehicle, and to achieve a smallest possible weight at sufficient strength.
[0016] On the other hand aluminum on the other hand offers a significant weight advantage also compared high strength steel, which is advantageous, in particular considering the current desire for lightweight construction.
[0017] When using aluminum it is also not necessary to provide the other sleeve with an addition corrosion protective layer because aluminum is naturally very corrosion resistant.
[0018] The production of a profiling according to the invention for forming a form fit between the outer sleeve and the elastomer part is hard to accomplish especially in the case of high-strength steel materials. In this case a material removing treatment of the steel elements would be necessary, which in the case of high-strength materials can be performed only with high effort. This additional work step in the case of steel materials can be conveniently integrated in the production process of the metallic outer sleeve.
[0019] In a particular embodiment of the invention, the profiling is configured as a number of webs, which extend on the inner sheath surface at least in sections parallel to the longitudinal axis of the outer sleeve.
[0020] The longitudinal axis of the outer sleeve means the axis which lies parallel to the inner sheath surfaces of the outer sleeve and along which the cylindrical inner metal part extends.
[0021] The webs thus extend from one axial end of the inner sheath surface to the other axial end, wherein they can be configured continuous and may also have interruptions.
[0022] It is also possible that the webs extend in a helical winding from one axial end to the other axial end of the outer sleeve. In this case, the webs form a type of inner threading, wherein the outer sleeve as a consequence has to be pressed onto the elastomer part in a rotating movement.
[0023] In a particularly preferred embodiment the webs, which extend parallel to the longitudinal axis, have an essentially triangular cross section. In this configuration the webs can burrow into the plastic layer of the elastomer part with the triangular tip which points in the direction of the elastomer part when pressing the outer sleeve onto the elastomer part. This also means a cutting/milling. This creates a form fit between the outer sleeve and the plastic layer of the elastomer part with minimal effort.
[0024] The corner of the triangle, which protrudes into the inner space of the outer sleeve, in this case does not necessarily have to be formed as a tip. It can also be a rounded tip which also enables a form fit with the plastic layer and can technically be formed easier during the extrusion method.
[0025] For the triangular shape of the webs different configurations are conceivable. The webs can have a cross section in the form of an equilateral triangle. When on the other hand a deeper engagement of the profiling into the plastic layer is required, a configuration as isosceles triangle is also possible, wherein in this case the height of the triangle is greater than the base of the, triangle. The height or the width of the triangle cross sections depends on the demands placed on the respective inner profiling. It may thus be necessary to provide a greater number of webs that engage deeper into the plastic layer. On the other hand it is also possible that only a small number of webs is required, which are distributed spaced apart along the circumference of the inner sheath surface and which have a smaller height of the webs.
[0026] In particular the expected torsion stress plays a role in the exact configuration of the outer sleeve according to the invention. At high torsion forces a greater number of webs is necessary in order to ensure the rotation resistance of the elastomer bearing. When only the elastomer part is to be non-detachably held on the outer sleeve a smaller number of webs can be selected.
[0027] In case of an uneven stress in both rotational directions it is useful to configure the cross section of the inner profiling as non-symmetric triangle. This means that the two sides of the triangle, which points into the inner space oft the outer sleeve, enclose different angles with the base surface of the triangle. In an elastomer bearing, which for example is exclusively exposed to stress in one rotational direction, the side of the triangle, which absorbs this rotational stress protrudes steeper into the inner space than the other triangle side. The base angle, which is enclosed by the stressed side, is then greater than the opposing base angle. The averted side surface of the triangle on the other hand extends shallower so that the elastomer part in case of a rotational stress can glide over this side of the triangle.
[0028] Also a mandrel-shaped configuration of the triangular cross section of the webs of the profiling is possible. In this case the side surfaces of the triangle which protrude into the inner region of the outer sleeve are configured concave, which results in a sharp tip compared to the base surface, which facilitates the forming of the form fit between the profiling and the plastic layer.
[0029] Preferably the webs are evenly distributed over the circumference of the inner sheath surface. As a result in particular an even load on the elastomer part is created so that in case of a strong torsional load the forces are evenly distributed across the elastomer part.
[0030] As described above the height of the profiling also depends on the magnitude of the occurring forces. Preferably the height of the profiling is 0.1% to 3% of the diameter of the elastomer bearing. In particular the overall height of the elastomer bearing plays an important role in this case. When the elastomer bearing has a great diameter, the profilings also have to be adjusted correspondingly in order to be able to compensate the occurring forces.
[0031] Of course the profiling should however not be configured so large so as to perforate the plastic layer of the elastomer part and burrows into the elastomer part itself. This would lead to crack formation in the elastomer part, which in turn would adversely affect the durability of the entire elastomer bearing.
[0032] All embodiments of the outer sleeve mentioned above can be advantageously generated very easily by means of different templates on the extrusion device. Almost any desired variations are possible. In order to change from one variant to the next it is not necessary to change the production tools in a laborious manner. Only exchange of the template of the extrusion system is required. As a result the production times of outer sleeves according to the invention are significantly reduced.
[0033] In a further embodiment of the elastomer bearing, it is provided that the elastomer part forms a press fit with the outer sleeve by integrating the plastic layer.
[0034] Hereby the elastomer part is pre-tensioned during pressing into the outer sleeve. As a result the plastic layer, which surrounds the elastomer part, is pressed against the outer sleeve. Overall a press fit is generated which in addition to the profiling of the outer sleeves effectively counteracts an undesired rotation of the components. A dual protection against the rotating of the components is generated, wherein the press fit and the form fit of profiling and plastic layer cooperate. This distinguishes the invention from conventional elastomer bearings with a bearing bracket or a steel bearing eye as outer sleeve, which due to the high strength of the material cannot be provided with a corresponding profiling, and where the rotation-proof connection is only generated by a press fit. Because steel is sensitive against corrosion and correspondingly has to be provided with a coating which lowers the friction between the outer sleeve and the elastomer part, such conventional elastomer bearings often involve the risk that the outer sleeves slip from the elastomer part or the elastomer parts rotate in the outer sleeves.
[0035] In a further preferred embodiment of the invention, the elastomer part is configured multi-part. The elastomer part as a whole usually has a cylindrical basic shape with a bore for the inner metal part and can be pushed onto the inner metal part. In case of components with complex shapes such as stabilizers it is often not possible to simply push the elastomer part into the provided bearing region. In this case it is advantageous to form the elastomer part from two or more individual elements.
[0036] In a preferred embodiment of the elastomer bearing the outer sleeve is configured as multi-chamber extruded profile.
[0037] Such an extruded profile has a chamber, which serves as outer sleeve for the elastomer part. This chamber is usually circular and has the profiling according to the invention at its inner sheath surface. The additional chambers serve as connection elements by means of which the outer sleeve can be arranged on the vehicle body or a subframe or on a control arm. The shape of these additional chambers can be adjusted to the predetermined attachment sites in any desired manner.
[0038] For example a circular opening can also be generated so that a connection via a bolt or a threaded connection is possible. By a subsequent material removing processing a threading can be introduced here.
[0039] Also any other desired connection element can be molded by which then a form fitting connection with the vehicle body of the subframe can be generated.
[0040] The outer sleeve further has preferably attachment elements and/or openings, which are generated by material removing processing. Also these embodiments of the invention serve for enabling attachment of the outer sleeve on the vehicle body or subframe and the like. Thus it is possible that oblong holes, grooves or threadings are introduced into the aluminum extruded profiles by which then in turn bolts or screws can be guided in order to enable the attachment of the outer sleeve.
[0041] Especially in combination with the configuration of the outer sleeve described above as multi chamber extruded profiles, many design possibilities exist in order to produce attachment elements and/or attachment openings that are adjusted to the mounting space and the constructive demands.
[0042] A further particular embodiment of the invention provides that the inner metal part is a hollow cylinder. In this embodiment an attachment site for the control arm, for example on the wheel carrier, is created when using the elastomer bearing on a vehicle control arm.
[0043] In a further embodiment of the invention, it is provided that the elastomer part is connected with the inner metal part via an adhesive connection or is vulcanized onto the inner metal part.
[0044] Also on the connection site between the inner metal part and the elastomer part it is necessary to obtain a sufficient rotation resistance and stability of the elastomer par. This can be achieved by a material bonding connection such as an adhesive connection or vulcanizing. The adhesive connection as wells as the vulcanizing can be realized very easily during assembly because the inner metal part is easily accessible and can easily be provided with glue or adhesives.
[0045] After arranging the elastomer part on the thus pretreated inner metal part, the metallic outer sleeve can also already be pushed on so that the adhesive connection or vulcanizing can be produced under the pre-tension generated by the outer sleeve.
[0046] A further embodiment of the invention provides that the plastic layer is vulcanized onto the elastomer part.
[0047] In order to ensure that the rotation resistance, which is generated by the form fit between the profiling of the outer sleeve and the plastic layer, is stable a durable connection between the plastic player and the elastomer part also has to be established. Because here a load bearable mechanical connection is difficult to achieve, a vulcanizing is most appropriate to generate a rotation-proof connection between the elastomer part and the plastic layer.
[0048] In a further embodiment of the invention, the elastomer part of the elastomer bearing has a circumferential shoulder on the axial borders of its outer sheath surface.
[0049] Beside the rotation resistance of the elastomer part in the outer sleeve, the axial non-displacability of the elastomer part in the outer sleeve is also an important criteria for the proper functioning of the elastomer bearing. The elastomer part therefore has a shoulder its front side ends. This means that the diameter of the elastomer part at its axial borders is slightly greater than in the remaining regions. As a result the elastomer part overlaps the outer sleeve with the shoulders and thus ensures that the outer sleeve cannot slide off the elastomer part in case of an axial load on the elastomer bearing. This also occurs in cooperation with the press fit between the elastomer part and the outer sleeve, which additionally supports the axial direction.
[0050] In a preferred embodiment, the outer sleeve has on the axial borders if its inner sheath surface a circumferential chamfer, which is in engagement with the shoulder of the elastomer part.
[0051] This means that the outer sleeve at its axial ends has a slightly greater inner diameter than in the center regions. This border region is configured complementary to the shoulder of the elastomer part so that the chamfer of the outer sleeve and the shoulder of the elastomer part engage in each other. As a result the axial securement is further improved so that the elastomer part is securely held in the outer sleeve.
[0052] Preferably the plastic layer on the outer sheath surface of the elastomer part is made of polyamide.
[0053] The elastomer bearing according to the invention may be used as a bearing for a motor vehicle part. In particular this involves applications in parts in the vehicle chassis area, for example a stabilizer bearing or as attachment bearing for a control arm. It can also be used on a subframe or on a twist beam axle, as connection to the vehicle body or the like.
[0054] The configuration of the outer sleeve as extruded profiles allows using the elastomer bearing according to the invention in a broad range of applications. The configuration of the extruded profiles can be adjusted to the application, wherein multiple geometrical configurations are available.
[0055] According to another aspect of the invention, a method for producing an elastomer bearing, includes providing a cylindrical inner metal part, an elastomer part having a plastic layer on its outer sheath surface, and an outer sleeve, which is produced as one-piece extruded part from lightweight metal; pre-treating a surface of the cylindrical inner metal part; bringing the elastomer part into contact with the inner metal part; joining the elastomer part with the inner metal part with an adhesive or by vulcanizing; and pressing the outer sleeve onto the elastomer part during or after the joining, so that a profiling of an inner sheath surface of the outer sleeve comes into form fitting engagement with the plastic layer.
[0056] In this method the cylindrical inner metal part, which can be a solid or hollow cylinder or a bearing section of a stabilizer, is thus first provided with an adhesive or a bonding agent of the vulcanizing.
[0057] Subsequent thereto an elastomer part is brought into contact with the inner metal part in the region, which is provided with adhesive or bonding agent. The elastomer part can be made of a single piece, which has a cylindrical bore and is then pushed onto the cylindrical inner metal part.
[0058] However, it is also possible to use a multi-part elastomer part for example two half shells which then together form the elastomer part for the elastomer bearing. This variant is particularly advantageous when, as in the case of a stabilizer, the pushing on of a one-piece elastomer part is difficult or even impossible due to the geometrical configuration of the cylindrical inner metal part.
[0059] The outer sleeve is then pressed onto the elastomer part. This can occur before the adhesive connection or the vulcanizing is performed, for example in order to use the pre-tension generated by the outer sleeve in the elastomer part to support the generation of the materially bonding connection during the gluing or vulcanizing. On the other hand the outer sleeve can also be pressed onto the elastomer part, which is already securely connected with the inner metal part.
[0060] The outer sleeve has at its inner sheath surface a profiling, which during the pressing on comes into form fitting engagement with the plastic payer. As a result of this form fit an undesired rotation of the outer sleeve relative to the elastomer part is prevented.
[0061] For generating the form fitting engagement, the plastic layer is treated with material removing processing, cutting or is plastically deformed by the profiling during pressing on.
[0062] The pressing of the outer sleeve onto the elastomer part generates a pre-tension in the elastomer part, which in turn presses the elastomer part outwardly against the profiling. Depending on the strength of the pre-tension and the geometrical configuration of the profiling, the form fit is generated in different ways. Thus it is for example possible that the inner profiling removes a portion of the plastic layer, and so to speak mills a groove, in which the profiling then engages. The removed plastic material pushes the profiling during the pressing on process along in front of it. After completing the pressing on the removed material falls off.
[0063] When the profiling as described above is configured web-shaped and with a sharp tip, the engagement can also be generated by a cut of the inner profiling into the plastic layer.
[0064] It is also possible that the plastic layer is plastically deformed by the profiling without resulting in cracks, a tension or the like in the plastic. Then, the plastic layer is pressed against the profiling due to the pre-tension and is thereby plastically deformed. The resulting grooves can then engage in the profiling.
[0065] A further embodiment of the method provides that the surface of the cylindrical inner metal part is cleaned during the pretreatment and/or are provided with a primer.
[0066] A cleaning of the region in which the elastomer part is to be connected with the cylindrical inner metal part is advantageous because it significantly improves the subsequently generated material bonding connection. The cleaning can occur by means of chemicals, by heat treatment or by mechanical treatment. As a result of the cleaning the surface of the inner metal part is cleared of dirt and contaminations so that the subsequently generated material bonding is of higher quality.
[0067] Also the application of a primer serves to improve the adhesion between the inner metal part and the glue or the vulcanizing process.
[0068] It is further provided to heat the elastomer part to a temperature of 50° C. to 100° C., preferably of 60° C. to 80° C. prior to pressing on the outer sleeve.
[0069] As a result of this temperature treatment the elastomer part and the plastic layer become softer and more flexible thereby facilitating the generation of the form fitting engagement between the profiling and the outer sleeve and the plastic layer. In this case lower pressing forces are required so that the elastomer part is exposed to less stress during the pressing in process. This minimizes the risk of crack formation and with this less waste is produced or the durability of the elastomer bearings improved.
[0070] In a further embodiment of the method, the plastic layer is connected with the elastomer part by vulcanizing. This allows generating a stable and rotation-proof connection between the plastic and the elastomer part in a simple manner.
BRIEF DESCRIPTION OF THE DRAWING
[0071] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
[0072] FIG. 1 shows an elastomer bearing according to the invention in an embodiment as stabilizer bearing;
[0073] FIG. 2 shows an elastomer bearing according to the invention;
[0074] FIG. 3 shows an outer sleeve in a perspective view;
[0075] FIG. 4 a shows an outer sleeve in a cross section;
[0076] FIG. 4 b shows a section of FIG. 4 a;
[0077] FIG. 4 c shows the outer sleeve with inserted elastomer part; and
[0078] FIGS. 5 a to e show individual variants of the cross sectional shape of the profiling.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0079] Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
[0080] An exemplary embodiment for an elastomer bearing according to the invention is the use of such a bearing for connecting a stabilizer to the vehicle body or a subframe. FIG. 1 shows an end side section of a stabilizer 1 . Not shown are the center section and the other end of the stabilizer. The latter is configured equivalent to the here shown end. The stabilizer 1 as a stabilizer bearing 2 which is arranged on a bearing region 3 of the stabilizer 1 .
[0081] This stabilizer. 2 has an elastomer part 4 which surrounds the Bering region 3 of the stabilizer 1 . On its outer sheath surface the elastomer part 4 has a plastic layer which is here not further shown. The elastomer part 4 is surrounded by an outer sleeve 5 . This outer sleeve 5 past on its inner sheath surface a profiling which is here also not for the show and which form fittingly engages in the plastic layer of the elastomer part 4 .
[0082] For producing a stabilizer bearing 2 that bearing region 3 of the stabilizer 1 is first cleaned of contaminations for example lubricant residues zunder or oxidations. Thereafter a primer and a bonding agent are applied whereupon the elastomer part 4 is pushed onto the stabilizer 1 and contacts to stabilize a 1 in the bearing region 3 . The elastomer part 4 is at this time point already provided is a plastic layer on its outer sheath surface.
[0083] The elastomer part 4 is then pressed against the bearing region 3 and vulcanized onto the bearing region 3 under pre-tension and temperature influence.
[0084] The outer sleeve 5 is then pressed onto the elastomer part 4 . Hereby the elastomer part 4 was first heated to a temperature of 50° C. to 100° C., preferably 60° C. to 80° C. During pressing the outer sleeve 5 onto the elastomer part 4 the inner sheath surface of the outer sleeve 5 comes into form fitting engagement with the plastic layer of the elastomer part 4 . During the pressing on of the outer sleeve 5 the elastomer part 4 is pre-tensioned. As a result of this pre-tension the elastomer part 4 is pressed against the outer sleeve 5 . As a result of this pressing force the inner profiling of the outer sleeve 5 is pressed into the plastic layer of the elastomer part 4 . The plastic layer is thereby plastically deformed so that together with the inner profiling it forms a form fit. As a result of the heating the elastomer part 4 becomes softer and with this slightly more malleable thus facilitating the generation of the form fit.
[0085] As a result of the pre-tension of the elastomer part 4 a press fit is formed between the elastomer part 4 and the outer sleeve 5 by integrating the plastic layer.
[0086] As a result of the combination of press fit and form fit, a rotation-proof connection between the elastomer part 4 and the outer sleeve 5 is generated which prevents that during springing out of a vehicle wheel and the resulting rotation of the stabilizer the elastomer part 4 can slide in the outer sleeve 5 , whereby the stabilizer bearing 2 is stably connected to the vehicle body.
[0087] An elastomer bearing 6 according to the invention is shown in FIG. 2 . This embodiment is for example suited as control arm connection.
[0088] In this case, the elastomer bearing 6 has a cylindrical inner metal part 8 , which is surrounded by an elastomer part 4 . The elastomer part 4 has a plastic layer 7 at its outer sheath surface. The elastomer part 4 in turn is surrounded by an outer sleeve 5 . On the axial borders of its outer sheath surface the elastomer part 4 forms a shoulder 9 . This shoulder 9 overlaps the end faces 11 of the outer sleeve 5 . Together with the press fit this achieves that the elastomer part 4 is also non-displaceably held in the outer sleeve 5 . The outer sleeve 5 also has a connection opening 10 by which the elastomer bearing 6 can be connected to another vehicle part by means of a bolt or a threaded connection.
[0089] FIG. 3 shows an outer sleeve 5 without inner metal part 8 or elastomer part 4 . Here the profiling 12 can be clearly seen, which is configured in the form of webs which extend on the inner sheath surface 15 parallel to the longitudinal axis of the outer sleeve 5 .
[0090] On the axial borders of the inner sheath surface 15 , the outer sleeve 5 has a chamfer 13 which engages with the shoulder 9 of the elastomer part 4 shown in FIG. 2 . As a result the elastomer part 4 is secured in the outer sleeve 5 against displacement in axial direction.
[0091] In addition the outer sleeve 5 has a connection opening 10 and connection elements 14 .
[0092] The outer sleeve 5 according to the invention is made of a lightweight metal, preferably aluminum, and is produced as extruded profile. This embodiment represents an extruded profile with three chambers. One chamber forms the receiving opening 16 for the elastomer part 4 , whereas the other two chambers form the connection elements 14 . During the extrusion, the profiling 12 is already formed on the inner sheath surface 15 . A further material removing processing of the outer sleeve after producing the outer sleeve is therefore not strictly required to produce this profiling 12 .
[0093] Nevertheless further processing steps may follow for example in order to produce the chamfer 13 or a connection opening 10 .
[0094] Using aluminum or another lightweight metal as working material in addition saves weight. This weight saving can be further improved in that superfluous material is omitted. For example the additional chambers, which are here configured as connection elements 14 , can also be configured without the requirement of a connection possibility. This saves material and with this costs and additional weight.
[0095] By using aluminum as material it is further not necessary to apply an additional corrosion protection to the outer sleeve 5 as it would be required in the case of conventional sleeves made of steel, because aluminum is already corrosion resistant itself.
[0096] By using extrusion as manufacturing method it is also possible to configure the outer sleeve 5 very application oriented and to adjust it to the requirements.
[0097] Thus for example the number and position of the web shaped profilings 12 can be very easily varied in this exemplary embodiment depending of the demands on the entire component.
[0098] In this exemplary embodiment, the cross section of the profiling 12 is configured substantially triangular as shown in FIG. 4 b . FIG. 4 b shows an enlargement of a section of FIG. 4 a , which in turn shows a cross section of the outer sleeve 5 .
[0099] The triangular cross section of the profiling 12 is in this case equilateral triangles, wherein the tips of the triangles which point into the receiving opening 16 are not configured pointed but are rounded.
[0100] A variation of the cross sectional shape of the profiling is readily possible. Thus it is conceivable to configure asymmetric triangles for example in the form of a saw tooth, or mandrel-like triangles.
[0101] FIG. 4 c also shows the principle construction of the elastomer bearings ( 6 ) according to the invention, and illustrates particularly well that the plastic layer 7 circumferentially embraces the elastomer part 4 and is in form fitting engagement with the profiling 12 which extends radially inward. The inner metal part 8 itself in turn is located in the elastomer part 4 .
[0102] Individual variants of the cross sectional shape of the profiling 12 are shown in FIG. 5 . FIG. 5 a shows the configuration of a profiling 12 with an equilateral triangle as cross section. The base 17 of the triangle is formed by the inner sheath surface 15 of the outer sleeve 5 . The two side surfaces 18 , 19 of the triangle enclose the base angles α, β with the base 17 . The tip 20 of the triangle protrudes into the receiving opening 16 of the other sleeve 5 . FIG. 5 b shows a variation of the equilateral triangle, wherein the tip 21 is rounded and not tapered pointed as in the preceding exemplary embodiment.
[0103] When the profiling 12 is to engage deeper into the plastic layer 7 , an isosceles triangle is formed as possible cross sectional shape as shown in FIG. 5 c . Hereby the length of the base 17 remains constant relative to the preceding examples. However, the sides 18 , 19 of the triangle are longer. The height of the triangle is thus greater than the length of its base.
[0104] A possible embodiment of the asymmetric configuration of the triangle cross section is shown in FIG. 5 d . Here a rotational force 22 occurs which pushes against the side 18 of the triangle. In order to account for this one sided load the triangle is configured asymmetric where the angle α, which is enclosed between the side 18 and the base 17 , is greater than the angle β, which is enclosed by the side 19 and the base 17 . The side 18 correspondingly extends much steeper than the side 19 almost perpendicular to the base 17 so that a such configured profiling represents an effective resistance against the force 22 .
[0105] A mandrel-like configuration of the triangle is shown in FIG. 5 e . Here the triangle has concave sides 23 , 24 , which allows the tip 25 to be configured sharper than for example in the examples 5a and 5c.
[0106] While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and, practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
[0107] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein: | An elastomer bearing, includes a cylindrical inner metal part, a metallic outer sleeve arranged at a radial distance around the inner metal part; and an elastomer part arranged between the inner metal part and the metallic outer sleeve. The elastomer part has an outer sheath provided with a plastic layer. The outer sleeve is constructed as a one-piece extruded part made of lightweight metal, and the outer sleeve has an inner sheath surface provided with a profiling which form fittingly engages in the plastic layer. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority to Provisional Application No. 60/439,024, filed Jan. 10, 2003, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a ski sled with boot blocks and a rider-operated weight-transfer device for steering. The boot blocks are provided with fixed and/or variable angle adjustment devices for changing the angle of the ski bottoms with respect to the snow surface, and the toe-in angle of the skis with respect to each other. Further, the boot blocks are provided with lengthwise adjustment mechanisms so that the boot blocks may be attached to any standard ski binding used on any ski without modification or any special attachments to the bindings or the skis.
2. Description of Background Art
A variety of snow sleds are available, some requiring the rider to be in a lying down, prone position, while others are provided with a seat. Conventionally, in order for a snow sled to be steerable, either of two mechanisms is used. In the first steering mechanism, the sled has two runners fixed to a mid and rear portion the sled body. The front end of these runners are not fixed to the sled body and can be flexed laterally with respect to the direction of travel, thus enabling the sled to turn. In the second steering mechanism, one or two runners are attached at the front of the sled body by means of a pivot mechanism, thus allowing them to be turned laterally with respect to the direction of travel. Two more runners are fixed to the sled body rearward of the front runner(s).
Each of the above steering mechanisms is complicated. Moreover, conventional sleds do not emulate the experience of skiing.
SUMMARY AND OBJECT OF THE INVENTION
One object of the present invention is to solve the above-mentioned problems, by providing a simple snow sled created with a seat with a weight transfer device for steering. Another object of the present invention is to provide a simple device for attaching the seat body to runners or skis, the attachment device being adjustable in a longitudinal direction and pivotable about a longitudinal axis thereof.
According to a first aspect of the present invention, two skis are arranged side-by-side, the skis having forward tips arranged closer together than rear ends thereof, and inward edges angled downwardly at least while the sled is turning; a seat is supported by two legs, each of the legs being rotatably attached at a pivot point at a rear end of a chair rail; adjustable blocks fit into ski bindings on the skis, the blocks having angle adjustment devices mounted thereon for changing lateral pitches of the two skis, the chair rails being attached to the angle adjustment devices and the angle adjustment devices being attached to the blocks forward of the pivot points; and a weight transfer device operable by a rider is provided for transferring a partial weight of the rider from one of the two skis to the other, thus enabling the ski sled to turn.
With this novel invention, a user is able to use his existing skis, and by attaching a seat thereto, is able to create another sporty snow vehicle. Further, the user is able to change the pitch of the skis to accommodate different terrains.
According to a second aspect of the present invention, the weight transfer device of the ski sled includes hand-levers mounted adjacent to each side of the seat; cables extending from the hand-levers and being connected to the angle adjustment devices so that when the hand lever on one side of the sled is pulled, the block on an opposite side of the sled is articulated; right and left connecting members having lower ends attached to forward portions of the chair rails, and upper ends attached to right and left sides of a pivot member pivotably attached to the seat.
With this novel aspect of the present invention, the user is able to steer the ski sled by shifting the weight from one ski to another by pulling on either the right or the left hand lever.
According to a third aspect of the present invention, the weight transfer mechanism includes weight transfer device includes chair rail extensions extending forwardly from the chair rails; foot pedals rotatably attached to the chair rail extensions for actuating cables connected to the angle adjustment devices so that when the foot pedal on one side of the sled is pushed, the block on the same side of the sled is articulated.
With this novel aspect of the present invention, the user is able to steer using foot pedals.
According to a fourth aspect of the present invention, the boot blocks include a forward section having a toe piece and a rear hole; a rear section having a heel piece and a forward extension, the forward extension being inserted into the rear hole of the front section, the forward section being provided with an adjuster screw mechanism for adjusting a longitudinal position of the forward section relative to the rear section, so that the adjustable blocks are capable of fitting multiple ski bindings of the skis; an adjustable bracket attachable to the blocks in a plurality of different angles with respect to the longitudinal direction of the blocks to accommodate different toe-in angles of skis to which the blocks are mounted.
With this aspect of the invention, the boot blocks are usable with any standard ski bindings, and provide for easy toe-in adjustment to accommodate riders of different abilities.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIGS. 1( a )–( c ) illustrate a first embodiment of the ski sled of the present invention equipped with a hand-operated weight transfer device, in which FIG. 1( a ) is a side view, FIG. 1 ( b ) is a front view, and FIG. 1( c ) is a plan (top down) view;
FIGS. 2( a )–( c ) illustrate a second embodiment of the ski sled of the present invention equipped with foot-operated weight transfer device, in which FIG. 2( a ) is a side view, FIG. 2( b ) is a front view, and FIG. 2( c ) is a plan (top down) view;
FIGS. 3( a )–( b ) show front and side views of a folding seat configuration of the present invention, and FIG. 3 ( c ) shows the seat being a go-cart seat;
FIG. 4 shows a third embodiment (aircraft yoke steering) of the weight transfer device;
FIGS. 5( a ) and ( b ) show a fourth embodiment (handlebar steering) of the weight transfer device;
FIGS. 6( a ) and ( b ) show a fourth embodiment (tractor steering) of the weight transfer device;
FIGS. 7( a ) and ( b ) are side and top down views of the adjustable boot block with a mounting plate, FIG. 7( c ) shows the detail of the adjuster mechanism of the adjustable boot block;
FIGS. 8( a ), ( b ), and ( c ) are side, top down, and end views of the fixed bracket and the rotatable bracket included variable angle adjustment device of the present invention;
FIGS. 9( a ) and ( b ) show side and top down views of the left chair rail attached to the left articulating boot block through a variable angle adjustment device equipped with an infinite angle pivot adjuster;
FIGS. 10( a ), ( b ), and ( c ) show side, top down, and end views of the left chair rail attached to the left boot block through a fixed angle adjustment device equipped with multiple fixed angle blocks;
FIGS. 11 ( a ) and ( b ) show side and front views of a single boot block attached to a mono-ski, with FIGS. 11 ( c ) and ( d ) showing detailed side and top down views of the foot plate and braking mechanism of the single boot block; and
FIG. 12 is a simplified front view sketch of a weight transfer operation in which more weight is put on one ski while weight is taken away from the other ski.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment will be described with reference to FIGS. 1( a )–( c ). FIG. 1( a ) shows a side view of the ski sled 1 , including left ski 10 L with ski tip 10 t and ski tail 10 T, seat 11 , left leg 12 L, left chair rail 14 L, left leg 12 L being rotatably connected to the left chair rail 14 L at pivot pin P, left adjustable boot block 13 L, hand-operated weight transfer device 20 connnected to the seat at pivot pin L, and left connecting member 23 L.
FIG. 1( b ) is a front view of the seat 11 (shown is a bucket go-cart seat, however as described below, other seat types a possible) and weight transfer device 20 of the first embodiment of the present invention. The weight transfer device 20 includes handle bar 21 equipped with hand levers 21 L, 21 R for articulating left and right boot blocks 13 L, 13 R. In FIG. 1( b ), the right boot block 13 R is shown as being articulated by pulling on hand lever 21 L, which is attached by cable 21 C to the variable angle adjustment device 5 . Legs 12 L, 12 R and connecting members 23 L, 23 R are attached to right and left chair rails 14 L, 14 R by releasable pins 6 .
FIG. 1( c ) is a top down view of the first embodiment showing chair rails 14 L, 14 R parallel to each other and skis 10 L, 10 R toed inwardly. Details of the toe-in mechanism will be provided below.
As can be seen in FIGS. 1( a ) and 1 ( c ), boot blocks 1311 , 13 R fit into a standard ski bindings 9 L, 9 R. Boot blocks 13 L, 13 R are the same and may be used interchangeably on either ski 10 L, or 10 R.
Also, the seat 11 is inclined to the rear, and the rider's center of gravity is located between legs 12 L, 12 R and connecting member 23 L, 23 R.
The second embodiment will be described with reference to FIGS. 2( a )–( c ). FIG. 2( a ) shows a side view of the ski sled 1 , including left ski 10 L, seat 11 (go-cart seat), left leg 12 L, left chair rail 14 L, left adjustable boot block 13 L, foot-operated weight transfer device 8 which includes chair rail extensions 14 E.
FIG. 2( b ) is a front view of the seat 11 (bucket go-cart seat) and weight transfer device 8 of the second embodiment of the present invention. The weight transfer device 8 includes cable activators (pedals) 8 A, which are attached under left and right foot pegs 8 L, 8 R mounted on forward ends of chair rail extensions, for pulling cable 8 Cs attached respectively to variable angle adjustment devices 5 for articulating left and right boot blocks 13 L, 13 R. In FIG. 2( c ), the left boot block 13 L is shown as being articulated by pressing on left foot pedal (peg) 8 L.
FIG. 2( c ) is a top down view of the second embodiment showing chair rails 14 L, 14 R parallel to each other and skis 10 L, 10 R toed inwardly.
FIGS. 2( a ) and ( c ) show straps 7 L, 7 R which are provided to prevent seat 11 , which is attached to each of the chair rails 14 L, 14 R by pivot pins P, from falling over backwards. Unlike the first embodiment described above, the second embodiment does not have connecting member 23 L, 23 R. Instead, the seat is held upright when the rider's feet are placed on foot pedals (pegs) 8 L, 8 R.
FIGS. 3( a )–( c ) show various examples of the seat of the ski sled of the present invention, with FIGS. 3( a ) and ( b ) being front and side views of a collapsible folding seat, FIG. 3( c ) being a bucket go-cart seat.
FIG. 4 shows a third embodiment of the weight transfer device (aircraft yoke steering) in which pivot member 30 is attached to a midpoint of the seat, and vertical steering handle 31 is attached by hinge 33 to the pivot member 30 . The steering handle is moved to the left or right to apply downward pressure on either the left or right extending members 23 L, 23 R which are attached at upper ends to pivot member 30 . The hinge 33 allows the steering handle 31 to be folded down (in a forward direction) when sitting or getting up from the seat 11 . With the third embodiment, weight transfer from one ski to the other is accomplished by pressure applied to connecting member 23 L, 23 R as shown in FIG. 12 .
FIGS. 5( a ) and ( b ) show a fourth embodiment of the weight transfer device (handlebar steering with no brake levers) in which left and right hand grips 41 L, 41 R attached to pivot member 30 can be grasped on ends thereof to apply a steering force through connecting members 23 L, 23 R which are fixed at upper ends thereof to pivot member 30 . The pivot member is suspended from a front portion of seat 11 . With the fourth embodiment, weight transfer from one ski to the other is accomplished by pressure applied to connection members 23 L or 23 R as shown conceptually in FIG. 12 .
FIGS. 6( a ) and ( b ) shows front and side views of a fifth embodiment. In this embodiment, left and right tractor steering handles 60 L, 60 R are provided instead of the hand levers (embodiment 1 ), the foot pedals (embodiment 2 ), the yoke steering handle (embodiment 3 ), or the handle bar (embodiment 4 ). Tractor steering handles 60 L, 60 R attached to seat 11 by pins 61 L, 61 R and are connected to pivot member 30 for shifting weight through connecting members 23 L, 23 R to either of the skis 10 L, 10 R.
FIGS. 7( a ) and ( b ) are side and top down views of the boot block 13 with a mounting plate 130 attached to the boot block 13 by screws. The designation F indicates the front of the boot blocks. FIG. 7( b ) shows the detail of the lengthwise adjuster mechanism 132 inserted into a hole at the front end of each adjustable boot block 13 for the purpose of adjusting the length of the boot blocks 13 to the bindings 9 of the skis, as shown in FIGS. 1( a ) and 2 ( a ). Also shown in FIG. 7( b ) are forward section 13 F of the boot block 13 with toe piece 13 T and rear hole 13 H, rear section 13 r , heal piece 13 h , and forward extension 13 E.
FIGS. 8( a ), ( b ), and ( c ) show side, top down, and end views, respectively, of the toe-in mechanism, including the fixed bracket 133 , the rotatable bracket 134 , and fixing members 136 which firmly hold together the fixed bracket 133 and the rotatable bracket 134 . Chair rails 14 (shown in FIGS. 1( c ) and 2 ( c )) are attached to inside faces 137 of rotatable brackets 134 . As shown in FIG. 8( b ), position adjustment holes 135 are provided on the fixed angle brackets 133 for adjusting the longitudinal angle of the fixed angle brackets 133 with respect to the longitudinal direction the flat mounting plate 130 fixed to each boot block 13 . By altering the longitudinal angle of the fixed angle brackets 133 , the toe-in angle of the ski sled can be easily adjusted to accommodate riders having different abilities, as well as for varying snow and ski slope conditions. Bolt attachments are shown here, but other attachable/detachable mounting attachments are possible.
FIGS. 9( a ) and ( b ) show side and top down views of the left chair rail 14 L attached to the left articulating boot block 13 equipped with a variable angle adjustment device 138 having an infinite angle pivot adjuster mechanism 139 . The chair rail 14 L is attached to the boot block as can be seen in both FIGS. 9( a ) and ( b ). Note in FIG. 9( b ) that the chair rail 14 L is mounted at an angle relative to the boot block 13 L, which means the left ski is toed-in. The toe-in angle is adjustable for riders of different abilities and for different snow conditions.
FIG. 9( b ) shows cable 21 C, 8 C, which is operable by either the hand lever 21 R (shown in embodiment 1 , FIG. 1( c )), or foot pedal (peg) 8 L (shown in embodiment 2 , FIG. 2( c )).
FIGS. 10( a ), ( b ), and ( c ) show side, top down, and end views of the left chair rail attached to the left boot block through a fixed angle adjustment device 140 equipped with multiple fixed angle blocks 141 , 142 , 143 . Blocks 141 , 142 , 143 may be substituted on the boot blocks to accommodate riders having different abilities as well as for different snow and slope conditions.
Other elements described above are not repeated here.
FIGS. 11 ( a ) and ( b ) show side and front views of a single boot block attached to a mono-ski, with FIGS. 11 ( c ) and ( d ) showing detailed side and top down views of the foot plate and “run away ski” braking mechanism of the single boot block.
Applications for the ski sled of the present are many.
For handicapped skiers, the invention provides a sled with a comfortable seat that is easy to sit in and stand up from. The sled is suitable for either ski slopes rated as “green” or “mild blue”. Further, the sled can be easily adapted to a rope tow or a J-bar lift. In addition, the sled is practical to use on back yard hills.
For beginning and handicapped skiers, the sled provides an excellent way for inexperienced skiers to experience the feeling and mechanics of skiing around a mountain, giving the rider a true taste of the skiing experience.
For expert skiers, the fold up version provides the mobility to ski downhill on “black diamond” slopes, with the sled being carried on the skier's back. When a “green” or “blue” slope is approached, the skier can snap the seat onto the skis, sit back and relax as the ski sled glides downward. The foldable seat version is particularly suited to back country skiers.
A wide stance, foot steer version of the present invention with a seat belt could even be used with a wind-powered traction kite, giving the user holding the traction kite the run of the country side when it snows.
Operation of the ski sled is simple. The skis are set in a ski stance, with the inner edges bearing and distributing the weight at proper places on the skis. For the first embodiment of the present invention, to turn left, pull on the right hand lever on the end of the handle bar. To turn right, pull on the left hand lever on the handle bar. The other embodiments operate is a similar manner.
Production of the ski sled can be made simple by merely using a few lightweight, molded plastic, metal or composite parts, assorted bars and handles, fasteners for connecting the parts devices, an instruction sheet, and a traveling bag.
Numerous variations to the above-described embodiments are to be considered within the scope of this invention. For example, a prone platform may be substituted for a seat. Various types of skis may be used including cross-country skis, mountaineering skis, and downhill skis of many styles. The sled may be adapted with a hand or foot operated braking mechanism to cause a dragging force in the snow. Various attachment mechanisms are possible, such as quick-release fastening devices, screws and other adjustment mechanisms, and hydraulic activators. Gas shock absorbers or springs may be included in the legs and or the connecting members. A heavy-duty version of the ski sled may include an extruded aluminum swing arm, bucket seat, with a fully articulated suspension and harness.
A motor sled is possible using a small horsepower motor and a tank track or tread device for applying power to the snow.
These and other variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | A ski sled with adjustable boot blocks and a rider-operated weight-transfer device for rider-controlled steering. The boot blocks are provided with fixed and/or variable angle adjustment devices for changing the angle of the ski bottoms with respect to the snow surface, and the toe-in angle of the skis with respect to each other. Further, the boot blocks are provided with lengthwise adjustment mechanisms so that the boot blocks may be attached to any standard ski binding used on any ski without modification or any special attachments to the bindings or the skis. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to the control of phytopathogens which attack plants through the soil. More particularly, the invention provides a new method of protecting plants from soil-borne phytophthora phytopathogens.
Beginning in the early 1960's, Soper disclosed that 2,6-dinitroanilines possess herbicidal activity, most notably preemergent herbicidal activity. See, for example, U.S. Pat. Nos. 3,111,403; 3,257,190; 3,332,769; and 3,367,949. Following Soper's lead, a large number of related dinitroanilines have also been shown to possess similar herbicidal activity. See, for example, U.S. Pat. Nos. 3,321,292; 3,617,251; 3,617,252; 3,672,864; 3,672,866; 3,764,624; and 3,877,924 and Belgian Pat. No. 787,939.
Malichenko et al., Fiziol. Aktiv. Veschestva 1969, 2, 75-8; C.A. 73, 13451e (1970), disclose that some 2,6-dinitroanilines bearing a trifluoromethyl group in the 4-position possess some activity against Phytophthora infestans, the causative organism of late blight of tomatoes.
Clark et al., U.S. Pat. No. 3,119,736, disclose a broad class of compounds alleged to be fungicides. The generic description of such compounds includes dinitroanilines, but there is no specific disclosure of 2,6-dinitroanilines.
Zsolnai, Biochemical Pharmacology 5, 287-304 (1961), discloses that certain 2,4-dinitroanilines possess some fungicidal activity against various organisms. No 2,6-dinitroaniline was disclosed.
Buczacki, Ann. Appl. Biol. 75, 25 (1973), tested five dinitroanilines against clubroot of cabbage with variable results. He concluded, however, that "dinitroanilines are unlikely to be of value in the control of clubroot."
Eshel and Katan, Weed Science 20, 243 (1972), observed the effects of four dinitroanilines against Rhizoctonia solani and Fusarium oxysporum. Three of the four test compounds decreased the growth of R. solani at the highest rates tested, but none of the four appreciably decreased the growth of F. oxysporum at any rate tested.
A study of trifluralin-treated soil by Breazeale and Camper, Appl. Microbiol. 19, 379 (1970), indicated that the actinomycete population increased as compared to the control, while the population of bacteria and fungi decreased.
SUMMARY OF THE INVENTION
The present invention provides a method for reducing the vigor of soil-borne phytophthora phytopathogens which comprises applying to soil infested with the phytopathogens a fungicidally-effective amount of a 2,6-dinitroaniline of one of the following formulae: ##STR1## wherein R 1 is H, C 2 -C 3 alkyl, chloroethyl, cyanoethyl, C 3 -C 4 alkenyl or halo C 3 -C 4 alkenyl;
when R 1 is H, R 2 is N(R 3 ) 2 , normal C 3 -C 6 alkyl, branched C 4 -C 7 alkyl containing no tertiary carbon atoms, 1-hydroxy-2-propyl, methallyl, N-ethyl-3-piperidyl, 2,6-dimethyl-1-piperidyl, 2,5-dimethylpyrrolidino or 2-ethyl-1-piperidyl;
when R 1 is not H, R 2 is 3-chloro-n-butyl, C 3 -C 4 alkenyl, halo C 3 -C 4 alkenyl, chloroethyl, cyclopropylmethyl, cyanoethyl, hydroxyethyl, n-C 3 H 7 , or epoxypropyl;
each R 3 is independently C 1 -C 3 alkyl; ##STR2## wherein R 4 is H or C 1 -C 3 alkyl;
when R 4 is H, R 5 is N(R 6 ) 2 , C 1 -C 7 normal or branched alkyl containing no tertiary carbon atoms, C 3 -C 4 alkenyl or N-methyl-2-propionamido;
when R 4 is C 1 -C 3 alkyl, R 5 is C 1 -C 4 alkyl or C 3 -C 4 alkenyl;
and each R 6 is independently C 1 -C 3 alkyl; ##STR3## wherein R 7 is H, CN, C 1 -C 3 alkyl or C 2 -C 3 alkanoyl;
R 8 is H or C 1 -C 3 alkyl;
when R 8 is H, R 9 is N(R 10 ) 2 , C 1 -C 6 normal or branched alkyl containing no tertiary carbon atoms, or C 3 -C 4 alkenyl;
when R 8 is C 1 -C 3 alkyl, R 9 is C 1 -C 3 alkyl, halo C 3 -C 4 alkenyl, propargyl, tetrahydrofurfuryl or C 3 -C 4 alkenyl; and
each R 10 is independently C 1 -C 3 alkyl; ##STR4## wherein R 11 is H or C 1 -C 3 alkyl;
when R 11 is H, R 12 is N(R 13 ) 2 , C 1 -C 4 normal or branched alkyl containing no tertiary carbon atoms, or C 3 -C 4 alkenyl;
when R 11 is C 1 -C 3 alkyl, R 12 is C 1 -C 3 alkyl or C 3 -C 4 alkenyl;
and each R 13 is independently C 1 -C 3 alkyl; ##STR5## wherein X is N(R 16 ) 2 , chloro, CH 3 , N═S(R 17 ) 2 , N(R 18 )CH 2 Het, C 1 -C 2 alkoxy, N═CHN(CH 3 ) 2 , N═C(R 19 )OR 20 , N═CHOR 21 or N 3 ;
R 14 is H, C 3 -C 4 alkenyl or C 1 -C 4 alkyl;
when R 14 is H, R 15 is C 3 -C 7 secondary alkyl;
when R 14 is not H, R 15 is C 1 -C 5 alkyl, cyclopropylmethyl, C 5 -C 6 cycloalkyl, C 3 -C 4 alkenyl, halo C 2 -C 3 alkyl or halo C 3 -C 4 alkenyl; one of R 16 is H or CH 3 and the other is H, SCCl 3 , CH 3 , phenylthio, OH, C 1 -C 4 alkoxy or NH 2 ;
each R 17 is independently C 1 -C 2 alkyl, phenyl or benzyl;
Het is 2,5-dimethylpyrrolidino, piperidino, morpholino, C 1 -C 2 alkylpiperidino, hexahydroazepino, 2,2-dimethylaziridino, or C 1 -C 2 alkylpiperazino;
R 18 is H or methyl;
R 19 is C 1 -C 2 alkyl or phenyl;
R 20 is C 1 -C 4 alkyl; and
R 21 is C 1 -C 2 alkyl; ##STR6## wherein R 22 is cyano C 1 -C 3 alkyl, halo, or C 1 -C 4 alkyl;
R 23 is H, chloroethyl, hydroxyethyl or C 1 -C 4 nontertiary alkyl; and
when R 23 is H, R 24 is C 3 -C 7 secondary alkyl;
when R 23 is not H, R 24 is C 1 -C 4 nontertiary alkyl, chloroethyl, hydroxyethyl, halo C 3 -C 4 alkenyl or C 3 -C 4 alkenyl; ##STR7## wherein Y is H or CH 3 ;
Z is NH 2 , Cl, CH 3 , or OCH 3 ;
R 25 is H or C 2 -C 4 nontertiary alkyl; and
when R 25 is H, R 26 is C 3 -C 7 secondary alkyl or N-methyl-2-propionamido;
when R 25 is C 2 -C 4 nontertiary alkyl, R 26 is C 2 -C 4 nontertiary alkyl or C 3 -C 4 alkenyl; ##STR8## wherein Q is OH, OCH 3 , SCH 3 , SCN, SCH 2 CH 2 CN, SCH 2 CN, SCH 2 CO 2 CH 3 , CO 2 H, CONH 2 , or CH;
R 27 is H or C 1 -C 3 alkyl; and
when R 27 is H, R 28 is N(CH 3 ) 2 or C 1 -C 6 normal or branched alkyl containing no tertiary carbon atoms; and
when R 27 is C 1 -C 3 alkyl, R 28 is propargyl, tetrahydrofurfuryl or C 1 -C 4 nontertiary alkyl.
A particularly preferred embodiment is the method as described above wherein the dinitroaniline is a compound of the formula ##STR9## wherein X' is N(R 31 ) 2 , chloro, CH 3 , N═S(R 32 ) 2 , N(R 33 )CH 2 Het', C 1 -C 2 alkoxy, N═CHN(CH 3 ) 2 , N═C(R 34 )OR 35 , N═CHOR 36 or N 3 ;
R 29 is H, C 3 -C 4 alkenyl or C 1 -C 4 alkyl;
when R 29 is H, R 30 is C 3 -C 7 secondary alkyl;
when R 29 is not H, R 30 is C 1 -C 5 alkyl, cyclopropylmethyl, C 5 -C 6 cycloalkyl, C 3 -C 4 alkenyl, halo C 2 -C 3 alkyl or halo C 3 -C 4 alkenyl;
one of R 31 is H or CH 3 and the other is H, SCCl 3 , CH 3 , phenylthio, OH, C 1 -C 4 alkoxy or NH 2 ;
each R 32 is independently C 1 -C 2 alkyl, phenyl or benzyl;
Het' is 2,5-dimethylpyrrolidino, piperidino, morpholino, C 1 -C 2 alkylpiperidino, hexahydroazepino, 2,2-dimethylaziridino, or C 1 -C 2 alkylpiperazino;
R 33 is H or methyl;
R 34 is C 1 -C 2 alkyl or phenyl;
R 35 is C 1 -C 4 alkyl; and
R 36 is C 1 -C 2 alkyl.
It will be noted that the above formula is equivalent to Formula V above.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the most part, the compounds used in the method of this invention are well known in the agricultural chemical art. In order to assure that the reader fully understands the invention, however, the following compounds exemplary of those used in the invention are mentioned. It will be understood that these compounds are by no means exhaustive of the invention, nor do they bound its scope. They are, however, typical examples of the compounds useful herein.
__________________________________________________________________________ ##STR10##Q.sup.1 Q.sup.2 R R.sup.0__________________________________________________________________________CF.sub.3 H H n-C.sub.3 H.sub.7CF.sub.3 H H CH(CH.sub.3)CH(CH.sub.3)C.sub.2 H.sub.5CF.sub.3 H H CH(CH.sub.3)CH.sub.2 CH(CH.sub.3)C.sub.2 H.sub.5CF.sub.3 H H CH(CH.sub.3)CH.sub.2 CH.sub.2 CH(CH.sub.3) .sub.2CF.sub.3 H H n-C.sub.5 H.sub.11CF.sub.3 H H n-C.sub.6 H.sub.13CF.sub.3 H H CH.sub.2 CH(CH.sub.3).sub.2CF.sub.3 H H CH(CH.sub.3)C.sub.2 H.sub.5CF.sub.3 H H CH(CH.sub.3)C.sub.5 H.sub.11CF.sub.3 H H CH(CH.sub.3)C.sub.4 H.sub.9CF.sub.3 H H CH(CH.sub.3)C.sub.3 H.sub.7CF.sub.3 H H CH(C.sub.2 H.sub.5).sub.2CF.sub.3 H H CH(CH.sub.3 )CH(CH.sub.3).sub.2CF.sub.3 H H N(C.sub.3 H.sub.7).sub.2CF.sub.3 H C.sub.2 H.sub.5 CH.sub.2 CH.sub.2 CHClCH.sub.3CF.sub.3 H H ##STR11##CF.sub.3 H H CH(CH.sub.3)CH.sub.2 OHCF.sub.3 H H ##STR12##CF.sub.3 H H N(C.sub.2 H.sub.5).sub.2CF.sub.3 H H ##STR13##CF.sub.3 H H ##STR14##CF.sub.3 H H ##STR15##CF.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 H n-C.sub.3 H.sub.7 C.sub.2 H.sub.4 ClCF.sub.3 H n-C.sub.3 H.sub.7 cyclopropylmethylCF.sub.3 H C.sub.2 H.sub.5 methallylCF.sub.3 Cl CH.sub.3 CH.sub.3CF.sub.3 Cl H CH.sub.3CF.sub.3 Cl H CH(CH.sub.3)C.sub.2 H.sub.5CF.sub.3 Cl C.sub.2 H.sub.5 n-C.sub.3 H.sub.7CF.sub.3 Cl n-C.sub.3 H.sub.7 methallylCF.sub.3 Cl n-C.sub.3 H.sub.7 allylCF.sub.3 Cl C.sub.2 H.sub.5 methallylCF.sub.3 Cl n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 Cl H N(CH.sub.3).sub.2CF.sub.3 N.sub.3 C.sub.2 H.sub.5 C.sub.2 H.sub.5CF.sub.3 N.sub.3 CH.sub.3 n-C.sub.3 H.sub.7CF.sub.3 N.sub.3 H CH(CH.sub.3)C.sub.2 H.sub.5CF.sub.3 N.sub.3 H ##STR16##CF.sub.3 N.sub.3 H CH.sub.3CF.sub.3 N.sub.3 H CH(C.sub.2 H.sub.5).sub.2CF.sub.3 N.sub.3 H CH(C.sub.2 H.sub.5)C.sub.3 H.sub.7CF.sub.3 N.sub.3 CH.sub.3 CH.sub.3CF.sub.3 N.sub.3 C.sub.2 H.sub.5 n-C.sub.4 H.sub.9CF.sub.3 N.sub.3 C.sub.2 H.sub.5 n-C.sub.3 H.sub.7CF.sub.3 N.sub.3 C.sub.2 H.sub.5 methallylCF.sub.3 N.sub.3 n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 N.sub.3 H N(CH.sub.3).sub.2CF.sub.3 N.sub.3 H CH(CH.sub.3)CONHCH.sub.3 ##STR17## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NS(CH.sub.3).sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NH.sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 CH.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NCHN(CH.sub.3).sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR18## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR19## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NCHOC.sub.2 H.sub.5 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR20## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7H Cl C.sub.2 H.sub.5 C.sub.2 H.sub.5H NH.sub.2 C.sub.2 H.sub.5 C.sub.2 H.sub.5H OCH.sub.3 C.sub.2 H.sub.5 C.sub.2 H.sub.5CH.sub.3 Cl CH.sub.2 CH(CH.sub.3).sub.2 methallylCH.sub.3 Cl n-C.sub.4 H.sub.9 methallylCH.sub.3 Cl H CH(CH.sub.3)CONHCH.sub.3CH.sub.3 CH.sub.3 H CH(C.sub.2 H.sub.5).sub.2H CH.sub.3 n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CH(CH.sub.3).sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7C(CH.sub.3).sub.3 H H CH(CH.sub.3).sub.2 H.sub.5CF.sub.3 OCH.sub.3 H CH(C.sub.2 H.sub.5).sub.2CF.sub.3 OCH.sub.3 n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 OCH.sub.3 C.sub.2 H.sub.5 C.sub.2 H.sub.5CF.sub.3 OH C.sub.2 H.sub.5 C.sub.2 H.sub.5CF.sub.3 OCH.sub.3 H CH.sub.3CF.sub.3 CH.sub.3 n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 CO.sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 CONH.sub.2 H CH(C.sub.2 H.sub.5).sub.2CF.sub.3 CN n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 CONH.sub.2 C.sub.2 H.sub.5 n-C.sub.4 H.sub.9CF.sub.3 OCH.sub.3 CH.sub.3 CH.sub.3CF.sub.3 SCH.sub.3 H CH(C.sub.2 H.sub.5).sub.2CF.sub.3 SCN H CH(C.sub.2 H.sub.5).sub.2CF.sub.3 SCH.sub.2 CO.sub.2 CH.sub.3 H CH(C.sub.2 H.sub.5).sub.2CF.sub.3 SCH.sub.2 CH.sub.2 CN H CH.sub.3CF.sub.3 SCH.sub.2 CN C.sub.2 H.sub.5 C.sub.2 H.sub.5CF.sub.3 SCN H CH.sub.3CF.sub.3 SCH.sub.2 CH.sub.2 CN H CH)C.sub.2 H.sub.5).sub.2CF.sub.3 SCN CH.sub.3 CH.sub.3CF.sub.3 SCN H N(CH.sub.3).sub.2CF.sub.3 SCN n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 SCN C.sub.2 H.sub.5 C.sub.2 H.sub.5CF.sub.3 NHCH.sub.3 H CH.sub.3CF.sub.3 NHCN H CH(C.sub.2 H.sub.5).sub. 2CF.sub.3 NHCN n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 NH.sub.2 H CH(C.sub.2 H.sub.5).sub.2CF.sub.3 NH.sub.2 n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 NH.sub.2 C.sub.2 H.sub.5 C.sub.2 H.sub.5CF.sub.3 NH.sub.2 C.sub.2 H.sub.5 methallylCF.sub.3 NH.sub.2 CH.sub.3 CH.sub.3CF.sub.3 NH.sub.2 H CH.sub.3CF.sub.3 NH.sub.2 H N(CH.sub.3).sub.2CF.sub.3 NH.sub.2 H CH(C.sub.2 H.sub.5)C.sub.3 H.sub.7CF.sub.3 HN.sub.2 H CH(CH.sub.3)C.sub.3 H.sub.7CF.sub.3 H H N(CH.sub.3).sub.2CF.sub.3 H H ##STR21##CF.sub.3 NHCN H n-C.sub.3 H.sub.7SO.sub.2 N.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 N(CH.sub.3)OCH.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NH.sub.2 H CH.sub.3 C.sub.2 H.sub.5SO.sub.2 NH.sub.2 H H CH(C.sub.2 H.sub.5).sub.2SO.sub.2 NHNH.sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 N(CH.sub.3).sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NHCH.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NH.sub.2 H C.sub.2 H.sub.5 C.sub.2 H.sub.5SO.sub.2 N(CH.sub.3)OH H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NHOCH.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NH.sub.2 H C.sub.2 H.sub.5 methallylSO.sub.2 NH.sub.2 H C.sub.2 H.sub.5 ##STR22##CF.sub.3 NHCOCH.sub.3 C.sub.2 H.sub.5 C.sub.2 H.sub.5CF.sub.3 Cl H n-C.sub.3 H.sub.7CF.sub.3 Cl CH.sub.3 C.sub.2 H.sub.5CF.sub.3 SCN C.sub.2 H.sub.5 C.sub.2 H.sub.5CF.sub.3 NHCN C.sub.2 H.sub.5 C.sub.2 H.sub.5CF.sub.3 H CH.sub.2 CH.sub.2 Cl CH.sub.2 CH.sub.2 ClCF.sub.3 H C.sub.2 H.sub.5 CH.sub.2 CH.sub.2 OHCF.sub.3 H C.sub.2 H.sub.5 ##STR23##CF.sub.3 H n-C.sub.3 H.sub.7 CH.sub.2 CHCH.sub.2CF.sub.3 H n-C.sub.3 H.sub.7 ##STR24## ##STR25## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR26## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR27## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR28## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR29## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR30## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR31## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 ##STR32## H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NH.sub.2 H CH.sub.2 CHCH.sub.2 CH.sub.2 CHCH.sub.2SO.sub.2 N.sub.3 H CH.sub.2 CHCH.sub.2 CH.sub.2 CHCH.sub.2SO.sub.2 NHOCH.sub.3 H CH.sub.2 CHCH.sub.2 CH.sub.2 CHCH.sub.2SO.sub.2 NS(C.sub.2 H.sub.5).sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NS(CH.sub.3)C.sub.2 H.sub.5 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NHSC.sub.6 H.sub.5 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NS(CH.sub.3)C.sub.6 H.sub.5 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NS(C.sub.6 H.sub.5).sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NS(CH.sub.2 C.sub.6 H.sub.5).sub.2 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 SCN CH.sub.3 ##STR33##C(CH.sub.3).sub.2 CN H C.sub.2 H.sub.5 C.sub.2 H.sub.5SO.sub.2 NC(C.sub.2 H.sub.5)OC.sub.2 H.sub.5 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NC(C.sub.6 H.sub.5)OCH.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 H CH.sub.2 CHCH.sub.2 CH.sub.2 CHCH.sub.2CF.sub.3 H CH.sub.2 CH.sub.2 CN CH.sub.2 CH.sub.2 CNCH.sub.3 H CH.sub.2 CH.sub.2 Cl CH.sub.2 CH.sub.2 ClCH.sub.3 H CH.sub.2 CH.sub.2 OH CH.sub.2 CH.sub.2 OHCF.sub.3 H n-C.sub.3 H.sub.7 CH.sub.2 CH.sub.2 OHC(CH.sub.3).sub.2 CN H H CH(CH.sub.3)C.sub.2 H.sub.5CF.sub.3 SCN CH.sub.3 2 CCHC(CH.sub.3).sub.2 H n-C.sub.3 H.sub.7 ##STR34##CH.sub.2 CN H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.3 CH.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NH.sub.2 H n-C.sub.3 H.sub.7 cyclopropylmethylSO.sub.2 NH.sub.2 H CH.sub.3 CH(CH.sub.3)C.sub.3 H.sub.7SO.sub.2 NH.sub.2 H CH.sub.2 CHCH.sub.2 ##STR35##SO.sub.2 NH.sub.2 H n-C.sub.3 H.sub.7 CH.sub.2 CH(CH.sub.3).sub.2SO.sub.2 Cl H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7CF.sub.3 NHCN CH.sub.3 2 CCHCF.sub.3 NHCN CH.sub.3 ##STR36##CF.sub.3 NHCN n-C.sub.3 H.sub.7 ##STR37##SO.sub.2 N(CH.sub.3)SCCl.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NC(CH.sub. 3)OC.sub.4 H.sub.9 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NC(C.sub.6 H.sub.5)OC.sub.2 H.sub.5 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NHOC.sub.4 H.sub.9 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NC(C.sub.2 H.sub.5)OCH.sub.3 H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NH.sub.2 H CH.sub.3 cyclopentylSO.sub.2 NHCH.sub.3 H n-C.sub.3 H.sub.7 cyclopropylmethylCl H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7SO.sub.2 NHOH H n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7__________________________________________________________________________
in general, the compounds used in this invention are prepared by methods now known to agricultural chemists.
Exceptions to this general rule are the 3-azido compounds of Formula II, the cyanamines of Formula III and some of the sulfur-containing compounds of Formula VIII, all of which are recently synthesized compounds.
Those compounds useful in this invention which are known in the herbicide art are prepared by methods described in the various patents listed in the prior art section of this specification and all of which are incorporated herein by reference. Since the preparative procedures described in such patents are sufficient to allow those skilled in the art to prepare the compounds, no attempt will be made here to further describe the preparation of such compounds.
The 3-azido compounds of Formula II, the cyanamines of Formula III and the sulfur-containing compounds of Formula VIII are prepared from the corresponding 3-chloro compounds. The 3-chloro compounds are intermediates in the preparation of the 1,3-phenylenediamines of U.S. Pat. No. 3,617,252 and the 3-alkoxy and alkylthio compounds of U.S. Pat. No. 3,764,624 and the preparation of the 3-chloro intermediates is described in both such patents.
The 3-azido compounds are prepared, for example, by the reaction of the corresponding 3-chloro compound with an alkali metal azide such as sodium azide in the presence of an inert solvent such as dimethylformamide. The reaction is conveniently run at room temperature. The 3-thiocyanato compounds are prepared in a similar manner employing an alkali metal sulfide such as sodium sulfide and cyanogen chloride. Compounds bearing a cyanomethylthio group in the 3-position are prepared from the corresponding 3-chloro compound by reaction with sodium sulfide and chloroacetonitrile. The other sulfur-containing compounds are prepared by reaction of the 3-chloro compound with the appropriate mercapto compound in the presence of an alkali metal hydroxide such as lithium hydroxide or potassium hydroxide. The cyanamines are prepared by heating the 3-chloro intermediate with cyanamide in the presence of a tertiary amine such as triethylamine.
While it is believed that those skilled in the art can prepare all the compounds useful in the present invention, the following preparative examples are given to insure that the novel compounds described above can be readily prepared.
EXAMPLE 1
A solution of 2.3 g. of sodium azide in 15 ml. of water was added dropwise to a solution of 7 g. of 3-chloro-N,N-dimethyl-2,6-dinitro-4-trifluoromethylaniline in 90 ml. of dimethylformamide at room temperature. The mixture was stirred at room temperature for one hour, poured over ice-water and filtered to recover 6.9 g. (94%) of 3-azido-N,N-dimethyl-2,6-dinitro-4-trifluoromethylaniline, m.p. 66°-67° C. The structure was confirmed by the NMR and IR spectra and elemental analysis.
Calculated: C, 33.76; H, 2.20; N, 26.25. Found: C, 33.98; H, 2.19; N, 26.53.
EXAMPLE 2
A solution of 0.75 g. of sodium azide in 15 ml. of water was added dropwise to a solution of N-n-butyl-3-chloro-2,6-dinitro-N-ethyl-4-trifluoromethylaniline in 75 ml. of dimethylformamide at room temperature. The mixture was stirred at room temperature for 2 hours and poured over ice-water. The product separated as an oil. The mixture was extracted three times with metylene chloride, the methylene chloride was evaporated, the residue taken up in ether, and the ether solution extracted three times with water. Evaporation of the ether left 3.1 g. (92%) of 3-azido-N-n-butyl-2,6-dinitro-N-ethyl-4-trifluoromethylaniline as an oil. The structure was confirmed by the NMR and IR spectra and elemental analysis.
Calculated: C, 41.49; H, 4.02; N, 22.33. Found: C, 41,39; H, 3.89; N, 22.10.
EXAMPLE 3
A solution of 1.0 g. of sodium azide in 10 ml. of water was added dropwise to a solution of 3.2 g. of N-(3-chloro-2,6-dinitro-4-trifluoromethylphenyl)-N',N'-dimethylhydrazine in 80 ml. of dimethylformamide at room temperature. The mixture was stirred at room temperature for one hour, poured over ice-water and filtered. The solid product was dried and recrystallized from 2B ethanol to yield 3.1 g. (93%) of N-(3-azido-2,6-dinitro-4-trifluoromethylphenyl)-N',N'-dimethylhydrazine, m.p. 123°-125° C. The structure was confirmed by the NMR and IR spectra and elemental analysis.
Calculated: C, 32.25; H, 2.41; N, 29.25. Found: C, 32.21; H, 2.39; N, 29.34.
Following the procedure of Example 1, 2 or 3, the following additional compounds of Formula II were prepared.
______________________________________ R.sup.4 R.sup.5 Melting Point, ° C.______________________________________C.sub.2 H.sub.5 C.sub.2 H.sub.5 OilH CH(CH.sub.3)C.sub.3 H.sub.7 OilH CH(CH.sub.3)C.sub.2 H.sub.5 77-78H CH[CH(CH.sub.3).sub.2 ].sub.2 OilH CH(C.sub.2 H.sub.5)C.sub.3 H.sub.7 27-28H CH.sub.3 118-120C.sub.2 H.sub.5 n-C.sub.3 H.sub.7 OilH CH(C.sub.2 H.sub.5).sub.2 77-79n-C.sub.3 H.sub.7 n-C.sub.3 H.sub.7 OilH CH(CH.sub.3)CONHCH.sub.3 163, dec.H n-C.sub.3 H.sub.7 70-72C.sub.2 H.sub.5 methallyl 46-48______________________________________
EXAMPLE 4
A solution of 40 g. of 3-chloro-2,6-dinitro-N-(3-pentyl)-4-trifluoromethylaniline, 10.5 g. of cyanamide and 30 g. of triethylamine in 250 ml. of 3A ethanol was heated under reflux for 5 days. The solution was allowed to cool and was then poured over ice-water. The product which separated was recrystallized from 3A ethanol-water to give 36 g. (71%) of 3-cyanamino-2,6-dinitro-N-(3-pentyl)-4-trifluoromethylaniline, triethylamine salt, m.p. 135°-137° C. The structure was confirmed by the NMR and IR spectra and elemental analysis.
Calculated: C, 49.35; H, 6.32; N, 18.17. Found: C, 49.56; H, 6.06; N, 18.37.
Following the procedure of Example 4, the following additional compounds of Formula III were prepared. All were obtained as the triethylamine salt.
______________________________________R.sup.7 R.sup.8 R.sup.9 Melting Point, ° C.______________________________________CN n-C.sub.3 H.sub.7 nC.sub.3 H.sub.7 102-103CN C.sub.2 H.sub.5 C.sub.2 H.sub.5 122-124CN H nC.sub.3 H.sub.7 130-131CN CH.sub.3 C.sub.2 H.sub.5 84-86CN CH.sub.3 ##STR38## 98-100CN CH.sub.3 ##STR39## 129-132CN nC.sub.3 H.sub.7 ##STR40## 68-70______________________________________
the following cyanamino free bases were prepared by neutralizing the corresponding triethylamine salts with dilute hydrochloric acid in diethyl ether at room temperature.
______________________________________R.sup.7 R.sup.8 R.sup.9 Melting Point, ° C.______________________________________CN C.sub.2 H.sub.5 C.sub.2 H.sub.5 195-198CN H CH(C.sub.2 H.sub.5).sub.2 106-110CN H n-C.sub.3 H.sub.7 140-143______________________________________
EXAMPLE 5
To a cold solution of 40 g. of 3-chloro-2,6-dinitro-N-(3-pentyl)-4-trifluoromethylaniline in 400 ml. of dimethylformamide was added 36 g. of sodium sulfide nonahydrate in 100 ml. of water. The mixture was stirred for one-half hour and cyanogen chloride was bubbled into the cold solution for 10 minutes. The dark solution became light red. The reaction mixture was poured over ice-water and the solid product separated. Recrystallization from 3A ethanol-water gave 39 g. (89%) of 2,6-dinitro-N-(3-pentyl)-3-thiocyanato-4-trifluoromethylaniline, m.p. 97°-99° C. The structure was confirmed by the NMR spectrum and elemental analysis.
Calculated: C, 41.27; H, 3.46; N, 14.81. Found: C, 41.02; H, 3.40; N, 14.56.
Following the procedure of Example 5, the following additional compounds of Formula VIII were prepared.
______________________________________Q R.sup.23 R.sup.24 Melting Point, ° C.______________________________________SCN H CH.sub.3 125-126SCN CH.sub.3 CH.sub.3 153-155SCN H N(CH.sub.3).sub.2 146-148SCN nC.sub.3 H.sub.7 nC.sub.3 H.sub.7 OilSCN C.sub.2 H.sub.5 C.sub.2 H.sub.5 116-118SCN CH.sub.3 ##STR41## 75-76SCN CH.sub.3 ##STR42## 84-86SCN C.sub.2 H.sub.5 ##STR43## 92-94______________________________________
the preparation of 3-cyanomethylthio compounds is illustrated by the following example.
EXAMPLE 6
A mixture of 3.4 g. of 3-chloro-N,N-diethyl-2,6-dinitro-4-trifluoromethylaniline and 2.4 g. of sodium sulfide nonahydrate in dimethyl sulfoxide was stirred for 1 hour at 0° C. Chloroacetonitrile (0.76 g.) was added and the mixture was stirred overnight at room temperature. The reaction mixture was poured over ice and extracted with ether. The ether was evaporated and the residue was recrystallized twice from ethanol to yield 2.7 g. of 3-cyanomethylthio-N,N-diethyl-2,6-dinitro-4-trifluoromethylaniline, m.p. 77°-79° C. The structure was confirmed by the NMR spectrum.
The dinitroanilines of this invention have been shown to be effective in reducing the vigor of soil-borne phytophthora phytopathogens in in vivo tests. The tests reported below are exemplary of the compounds' potency.
The tests were performed by growing soybean seedlings in the greenhouse in soil heavily infested with Phytophthora megasperma var. sojae. The soil was obtained from a field where phytophthora-infected soybeans had been grown, and was further inoculated by mixing into the soil chopped soybean plants infected with P. megasperma.
The test compounds were formulated by dissolving them in a minimum amount of ethanol, and dispersing the ethanol solution in about 25 ml. of water which was mixed into approximately 10 kg. of screened phytophthora-infested soil. The soil was then spread into metal greenhouse flats, and Corsoy soybean seeds were planted.
Application rates of the test compounds were measured in kilograms per hectare of soil surface, and a sufficient quantity of each test compound was used to supply the application rates named in the tables below.
The flats were stored in the greenhouse and watered regularly for about 4 weeks, at which time the disease control effected by the test compounds was observed. The control was reported as percent control, compared to infested, untreated control plants.
Table 1______________________________________ Appln. Rate PercentCompound kg./ha. Control______________________________________3,5-dinitro-N.sup.4,N.sup.4 - 0.28 62di(n-propyl)-N.sup.1 -(2,5-dimethyl- 0.56 72pyrrolidinomethyl)-sulfanilamide 1.1 90 2.2 89 4.5 1003,5-dinitro-N.sup.4,N.sup.4 - 0.28 27di(n-propyl)-N.sup.1 -hexahydroazepino- 0.56 28methylsulfanil-amide 1.1 55 2.2 100 4.5 1003,5-dinitro-N.sup.4,N.sup.4 - 0.28 12di(n-propyl)-N.sup.1 -(1-methoxyethyli- 0.56 0dene)sulfanilamide 1.1 84 2.2 100 4.5 1003,5-dinitro-N.sup.4 - 0.56 34ethyl-N.sup.4 -propyl-sulfanilamide 1.1 34 2.2 80N.sup.4 -(2-chloro 0.56 50allyl)-N.sup.4 -ethyl-3,5-dinitro- 1.1 63sulfanilamide 2.2 803,5-dinitro-N.sup.4,N.sup.4 - 1.1 42di(n-propyl)-N.sup.1 -methyl-N.sup.1 -trichloro- 2.2 62methylthiosulfa-nilamide 4.5 622,6-dinitro-N- 1.1 67(2-hydroxyethyl)-N-(n-propyl)- 2.2 134-trifluoromethyl-aniline 4.5 80N.sup.4 -cyclopen- 1.1 80tyl-3,5-dinitro-N.sup.4 - 2.2 70methylsulfa-nilamide 4.5 613-cyanamino- 1.1 702,6-dinitro-N-(3-pentyl)- 2.2 624-trifluoro-methylaniline, 4.5 15triethylaminesalt2,6-dinitro- 1.1 63N-(3-pentyl)-3-thiocyanato- 2.2 814-trifluoro-methylaniline 4.5 632,6-dinitro- 0.56 55N.sup.1,N.sup.1 -diethyl-4-trifluoro- 1.1 52methyl-1,3-phenylene- 2.2 84diamine2,6-dinitro- 1.1 59N,N-di(n-propyl)-4-methylsulfonyl- 2.2 62aniline 4.5 1003,5-dinitro-N.sup.4,N.sup.4 - 1.1 6di(n-propyl)sul-fanilamide 2.2 80 4.5 912,6-dinitro-N,N- 1.1 16di(n-propyl)-4-trifluoromethyl- 2.2 55aniline 4.5 78N.sup.4,N.sup.4 -diethyl- 1.1 293,5-dinitro-sulfanilamide 2.2 51 4.5 494-azidosulfonyl- 1.1 353,5-dinitro-N,N-di(n-propyl)- 2.2 86aniline 4.5 100______________________________________
The test data reported above show that the compounds of this invention are particularly useful for the protection of plants from the adverse effects of soil-borne phytophthora phytopathogens. Accordingly, the invention is a new method of reducing the adverse effects of soil-borne phytophthora phytopathogens which comprises applying to phytophthora-infested soil a fungicidally-effective amount of a compound described herein.
As agricultural chemists will understand, practice of the method does not necessarily kill all, or even any, of the phytopathogens. As the data above show, application of a fungicidally-effective amount of a compound reduces the adverse effects of the disease, even though only a part, or even none, of the phytopathogen population may be killed by the compound. The term "fungicidally-effective amount" is used here to describe an amount which is sufficient to reduce the adverse effects of a soil-borne phytophthora phytopathogen. The term "reducing the adverse effects" refers to weakening the pathogen sufficiently that its reproduction rate and its vigor are decreased, with the result that the express signs of the disease, and the concomitant injury to the host plant, are decreased as compared with phytopathogens affecting plants growing in untreated soil.
The method of this invention is widely useful against the various plant diseases which are caused by soil-borne phytophthora phytopathogens. The following phytophthora organisms and diseases caused thereby are typical and illustrative of the phytopathogens controlled by this invention, but are by no means exhaustive thereof.
Phytophthora cactorum and P. parasitica, causative of stem and crown rot of tomato, cucurbits, rhubarb, apple, pear, strawberry, eggplant and pea
P. capsici, causative of root and fruit rot of pepper
P. cinnamoni, causative of root rot of avocado
P. fragariae, causative of red stele of strawberry
P. megasperma, causative of root rot of crucifers
P. palmivora, causative of root rot of citrus fruit trees and rubber
P. parasitica var. nicotianae, causative of black shank of tobacco
The method is preferably used for protecting soybeans from Phytophthora megasperma, the causative phytopathogen of soybean root rot. The compounds with which the method is preferably carried out are 3,5-dinitro-N 4 ,N 4 -di(n-propyl)-N 1 -(2,5-dimethylpyrrolidinomethyl)sulfanilamide, 3,5-dinitro-N 4 ,N 4 -di(n-propyl)-N 1 -hexahydroazepinomethylsulfanilamide, 3,5-dinitro-N 4 ,N 4 -di (n-propyl)-N 1 -(1-methoxyethylidene)sulfanilamide, 2,6-dinitro-N,N-di(n-propyl)-4-methylsulfonylaniline, 3,5-dinitro-N 4 ,N 4 -di (n-propyl)sulfanilamide, and 4-azidosulfonyl-3,5-dinitro-N,N-di(n-propyl)aniline.
As is usual in the protection of plants from soil-borne phytopathogens, the method of this invention will be usually carried out by applying the compounds to the soil at approximately the same time that the crop is being planted, as by incorporating the compound in the soil as the seed bed is being prepared. The method may also be used to benefit established plants by applying a compound of the invention to the soil around such plants.
The methods of formulating the compounds and preparing dispersions of the formulations, and the methods of applying dispersions of the compounds to the soil, are entirely conventional in the plant protection art. Some explanation of the methods of application will be given merely to assure that those skilled in the art can readily carry out the invention.
It is most meaningful to describe the application rate in terms of the amount of compound applied per unit area of soil. Compound application rates in the range of from about 0.1 to about 10 kg./ha. are used in the practice of this invention. Application rates higher and lower than the named range will at times be useful, depending upon the severity of the phytopathogenic invention, the weather, which has a strong effect on the vigor of phytopathogens, and the characteristics of the specific compound in use. Preferred application rates are in the general range of from about 0.5 to about 5 kg./ha.
The dispersions in which the compounds are applied are most often aqueous suspensions or emulsions prepared from concentrated formulations of the compounds. Such water-suspendible or emulsifiable formulations are either solids usually known as wettable powders or liquids usually known as emulsifiable concentrates. Wettable powders comprise an intimate mixture of the active compound, an inert carrier and surfactants. The concentration of the active compound is usually from about 10 percent to about 90 percent by weight. The inert carrier is usually chosen from among the attapulgite clays, the montmorillonite clays, the diatomaceous earths, or the purified silicates. Effective surfactants, comprising from about 0.5 percent to about 10 percent of the wettable powder, are found among the sulfonated lignins, the condensed naphthalenesulfonates, the naphthalenesulfonates, the alkylbenzenesulfonates, the alkyl sulfates, and nonionic surfactants such as ethylene oxide adducts of alkyl phenol.
Typical emulsifiable concentrates of the compounds comprise a convenient concentration of the compound, such as from about 100 to about 500 g. per liter of liquid, dissolved in an inert carrier which is a mixture of water-immiscible organic solvent and emulsifiers. Useful organic solvents include the aromatics, especially the xylenes, and the petroleum fractions, especially the high-boiling naphthalenic and olefinic portions of petroleum such as heavy aromatic naphtha. Other organic solvents may also be used, such as the terpenic solvents including rosin derivatives, and complex alcohols such as 2-ethoxyethanol. Suitable emulsifiers for emulsifiable concentrates are chosen from the same types of surfactants used for wettable powders.
The compounds can economically and conveniently be applied to the soil in the form of granular formulations . Such formulations, well known to the agricultural chemical art, are prepared by dispersing the compound on an inert carrier of controlled granular character. Most often, the carrier is a coarsely ground clay, such as attapulgite or kaolin clay, having a particle size in the range of from 0.5 to 3 mm. Such granular formulations are easily applied to the soil with applicators which are specially designed to apply accurately controlled amounts of the granular products to the soil. | A class of 2,6-dinitroanilines having a broad range of substituent groups on the anilino nitrogen and in the 3- and 4-positions of the phenyl ring are used for the protection of plants against soil-borne phytopathogens of the genus Phytophthora. | 0 |
This application is a continuation of application Ser. No. 07/988,530, filed Dec. 10, 1992, now abandoned, which is a continuation of application Ser. No. 07/656,797, filed Feb. 19, 1991, now abandoned, which is a divisional application of application Ser. No. 07/038,330, filed Apr. 13, 1987, now U.S. Pat. No. 5,030,714.
BACKGROUND OF THE INVENTION
The present invention relates to a virus capable of inducing lymphadenopathies (hereinafter "LAS") and acquired immuno-depressive syndromes (hereinafter "AIDS"), to antigens of this virus, particularly in a purified form, and to a process for producing these antigens, particularly antigens of the envelope of this virus. The invention also relates to polypeptides, whether glycosylated or not, produced by the virus and to DNA sequences which code for such polypeptides. The invention further relates to cloned DNA sequences hybridizable to genomic RNA and DNA of the lymphadenopathy associated virus (hereinafter "LAV") of this invention and to processes for their preparation and their use. The invention still further relates to a stable probe including a DNA sequence which can be used for the detection of the LAV virus of this invention or related viruses or DNA proviruses in any medium, particularly biological, and in samples containing any of them.
An important genetic polymorphism has been recognized for the human retrovirus which is the cause of AIDS and other diseases like LAS, AIDS-related complex (hereinafter "ARC") and probably some encephalopathies (for review, see Weiss, 1984). Indeed all of the isolates, analyzed until now, have had distinct restriction maps, even those recovered at the same place and time Benn et al., 1985!. Identical restriction maps have only been observed for the first two isolates which were designated LAV Alizon et al., 1984! and human T-cell lymphotropic virus type 3 (hereinafter "HTLV-3") Hahn et al., 1984! and which appear to be exceptions. The genetic polymorphism of the AIDS virus was better assessed after the determination of the complete nucleotide sequence of LAV Wain-Hobson et al., 1985!, HTLV-3 Ratner et al., 1985; Muesing et al., 1985! and a third isolate designated AIDS-associated retrovirus (hereinafter "ARV2") Sanchez-Pescador et al., 1985!. In particular, it appeared that, besides the nucleic acid variations responsible for the restriction map polymorphism, isolates could differ significantly at the protein level, especially in the envelope (up to 13% of difference between ARV and LAV), by both amino acids substitutions and reciprocal insertions-deletions Rabson and Martin, 1985!.
Nevertheless, such differences did not go so far as to destroy the immunological similarity of such isolates as evidenced by the capabilities of their similar proteins, (e.g., core proteins of similar nature, such as the p25 proteins, or similar envelope glycoproteins, such as the 110-120 kD glycoproteins) to immunologically cross-react. Accordingly, the proteins of any of said LAV viruses can be used for the in vitro detection of antibodies induced in vivo and present in biological fluids obtained from individuals infected with the other LAV variants. Therefore, these viruses are grouped together as a class of LAV viruses (hereinafter "LAV-1 viruses").
SUMMARY OF THE INVENTION
In accordance with this invention, a new virus has been discovered that is responsible for diseases clinically related to AIDS and that can be classified as a LAV-1 virus but that differs genetically from known LAV-1 viruses to a much larger extent than the known LAV-1 viruses differ from each other. The new virus is basically characterized by the cDNA sequence which is shown in FIGS. 7A to 7I and this new virus is hereinafter generally referred to as "LAV MAL "
Also in accordance with this invention, variants of the new virus are provided. The RNAs of these variants and the related cDNAs derived from said RNAs are hybridizable to corresponding parts of the cDNA of LAV MAL . The DNA of the new virus also is provided, as well as DNA fragments derived therefrom hybridizable with the genomic RNA of LAV MAL , such DNA and DNA fragments particularly consisting of the cDNA or cDNA fragments of LAV MAL or of recombinant DNAs containing such cDNA or cDNA fragments.
DNA recombinants containing the DNA or DNA fragments of LAV MAL or its variants are also provided. It is of course understood that fragments which would include some deletions or mutations which would not substantially alter their capability of also hybridizing with the retroviral genome of LAV MAL are to be considered as forming obvious equivalents of the DNA or DNA fragments referred to hereinabove.
Cloned probes are further provided which can be made starting from any DNA fragment according to the invention, as are recombinant DNAs containing such fragments, particularly any plasmids amplifiable in procaryotic or eucaryotic cells and carrying said fragments. Using cloned DNA containing a DNA fragment of LAV MAL as a molecular hybridization probe--either by marking with radionucleotides or with fluorescent reagents--LAV virion RNA may be detected directly, for example, in blood, body fluids and blood products (e.g., in antihemophylic factors such as Factor VIII concentrates). A suitable method for achieving such detection comprises immobilizing LAV MAL on a support (e.g., a nitrocellulose filter), disrupting the virion and hybridizing with a labelled (radiolabelled or "cold" fluorescent-- or enzyme-labelled) probe. Such an approach has already been developed for Hepatitis B virus in peripheral blood (according to Scotto J. et al. Hepatology (1983), 3, 379-384).
Probes according to the invention can also be used for rapid screening of genomic DNA derived from the tissue of patients with LAV related symptoms to see if the proviral DNA or RNA present in their tissues is related to LAV MAL . A method which can be used for such screening Comprises the following steps: extraction of DNA from tissue, restriction enzyme cleavage of said DNA, electrophoresis of the fragments and Southern blotting of genomic DNA from tissues and subsequent hybridization with labelled cloned LAV provil DNA. Hybridization in situ can also be used. Lymphatic fluids and tissues and other non-lymphatic tissues of humans, primates and other mammalian species can also be screened to see if other evolutionary related retroviruses exist. The methods referred to hereinabove can be used, although hybridization and washings would be done under non-stringent conditions.
The DNA according to the invention can be used also for achieving the expression of LAV viral antigens for diagnostic purposes, as well as for the production of a vaccine against LAV. Fragments of particular advantage in that respect will be discussed later. The methods which can be used are multifold:
a) DNA can be transfected into mammalian cells with appropriate selection markers by a variety of techniques, such as calcium phosphate precipitation, polyethylene glycol, protoplast-fusion, etc.
b) DNA fragments corresponding to genes can be cloned into expression vectors for E. coli, yeast or mammalian cells and the resultant proteins purified.
c) The provril DNA can be "shot-gunned" (fragmented) into procaryotic expression vectors to generate fusion polypeptides.
Recombinants, producing antigenically competent fusion proteins, can be identified by simply screening the recombinants with antibodies against LAV MAL antigens. Particular reference in this respect is made to those portions of the genome of LAV MAL which, in the figures, are shown to belong to open reading frames and which encode the products having the polypeptidic backbones shown.
Different polypeptides which appear in FIGS. 7A to 7I are still further provided. Methods disclosed in European application O 178 978 and in PCT application PCT/EP 85/00548, filed Oct. 18, 1985, are applicable for the production of such peptides from LAV MAL . In this regard, polypeptides are provided containing sequences in common with polypeptides comprising antigenic determinants included in the proteins encoded and expressed by the LAV MAL genome. Means are also provided for the detection of proteins of LAV MAL particularly for the diagnosis of AIDS or pre-AIDS or, to the contrary, for the detection of antibodies against LAV MAL or its proteins, particularly in patients afflicted with AIDS or pre-AIDS or more generally in asymtomatic carriers and in blood-related products. Further provided are immunogenic polypeptides and more particularly protective polypeptides for use in the preparation of vaccine compositions against AIDS or related syndromes.
Yet further provided are polypeptide fragments having lower molecular weights and having peptide sequences or fragments in common with those shown in FIGS. 7A to 7I. Fragments of smaller sizes can be obtained by resorting to known techniques, for instance, by cleaving the original larger polypeptide by enzymes capable of cleaving it at specific sites. By way of examples may be mentioned the enzyme of Staphylococcyus aureusV8, α-chymotrypsin, "mouse sub-maxillary gland protease" marketed by the Boehringer company, Vibrio alginolyticus chemovar iophaquscollagenase, which specifically recognizes the peptides Gly-Pro, Gly-Ala, etc.
Other features of this invention will appear in the following disclosure of data obtained starting from LAV MAL , in relation to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B provide comparative restriction maps of the genomas of LAV MAL as compared to LAV ELI (Applicants' related new LAV virus which is the subject of their copending application; filed herewith) and LAV BRU (a known LAV isolate deposited at the Collection Nationale des Cultures de Micro-organismes (hereinafter "CNCM") of the Pasteur Institute, Paris, France under No. I-232 on Jul. 15, 1983);
FIG. 2 shows comparative maps setting forth the relative positions of the open reading frames of the above genomas;
FIGS. 3A-3F (also designated generally hereinafter "FIG. 3") indicate the relative correspondence between the proteins (or glycoproteins) encoded by the open reading frames, whereby amino acid residues of protein sequences of LAV MAL are in vertical alignment with corresponding amino acid residues (numbered) of corresponding or homologous proteins or glycoproteins of LAV BR U, as well as LAVELI and ARV 2.
FIGS. 4A-4B (also designated generally hereinafter "FIG. 4") provide tables quantitating the sequence divergence between homologous proteins of LAV BR U, LAV ELI and LAV MAL ;
FIG. 5 shows diagrammatically the degree of divergence of the different virus envelope proteins;
FIGS. 6A and 6B ("FIG. 6" when consulted together) render apparent the direct repeats which appear in the proteins of the different AIDS virus isolates.
FIGS. 7A-7I show the full nucleotide sequences of LAV MAL .
DETAILED DESCRIPTION OF THE INVENTION
CHARACTERIZATION AND MOLECULAR CLONING OF AN AFRICAN ISOLATE
The different AIDS virus isolates concerned are designated by three letters of the patients name, LAV BRU referring to the prototype AIDS virus isolated in 1983 from a French homosexual patient with LAS and thought to have been infected in the USA in the preceding years Barre-Sinoussi et al., 1983!. LAV MAL was recovered in 1985 from a 7-year old boy from Zaire.
Related LAV ELI was recovered in 1983 from a 24-year old woman with AIDS from Zaire. Recovery and purification of the LAV MAL virus were performed according to the method disclosed in European Patent Application 84 401834/138 667 filed on Sep. 9, 1984.
LAV MAL is indistinguishable from the previously characterized isolates by its structural and biological properties in vitro. Virus metabolic labelling and immune precipitation by patient MAL sera, as well as reference sera, showed that the proteins of LAV MAL had the same molecular weight (hereinafter "MW") as, and cross-reacted immunologically with those of, prototype AIDS virus (data not shown) of the LAV-1 class.
Reference is again made to European Application 178 978 and International Application PCT/EP 85/00548 as concerns the purification, mapping and sequencing procedures used herein. See also the discussion under the headings "Experimental Procedures" and "significance of the Figures" hereinafter.
Primary restriction enzyme analysis of LAV MAL genome was done by Southern blot with total DNA derived from acutely infected lymphocytes, using cloned LAVBRU complete genome as probe. Overall cross-hybridization was observed under stringent conditions, but the restriction profile of the Zairian isolate was clearly different. Phage lambda clones carrying the complete viral genetic information were obtained and further characterized by restriction mapping and nucleotide sequence analysis. A clone (hereinafter "M-H11") was obtained by complete HindIII restriction of DNA from LAV MAL -infected cells, taking advantage of the existence of a unique HindIII site in the long terminal repeat (hereinafter "LTR"). M-H11 is thus probably derived from unintegrated viral DNA since that species was at least ten times more abundant than integrated provirus.
FIG. 1B gives a comparison of the restriction maps derived from the nucleotide sequences of LAV ELI , LAV MAL and prototype LAV BRU as well as from three other Zairian isolates (hereinafter "Z1", "Z2", and "Z3" respectively) previously mapped for seven restriction enzymes Benn et al., 1985!. Despite this limited number, all of the profiles are clearly different (out of the 23 sites making up the map of LAV BRU only seven are present in all six maps presented), confirming the genetic polymorphism of the AIDS virus. No obvious relationship is apparent between the five Zairian maps, and all of their common sites are also found in LAV BRU .
Conservation of the Gemetic Organization
The genetic organization of LAV MAL as deduced from the complete nucleotide sequences of its cloned genome is identical to that found in other isolates, i.e., 5' gag-pol-central region-env-F3 '. Most noticeable is the conservation of the "central region" (FIG. 2), located between the pol and env genes, which is composed of a series of overlapping open reading frames (hereinafter "orf") previously designated Q, R, S, T, and U in the ovine lentivirus visna Sonigo et al., 1985!. The product of orf S (also designated "tat") is implicated in the transactivation of virus expression Sodroski et al., 1985; Arya et al., 1985! ; the biological role of the product of orf Q (also designated "sor" or "orf A") is still unknown Lee et al., 1986;
Kang et al., 1986!. Of the three other orfs, R, T, and U, only orf R is likely to be a seventh viral gene, for the following reasons : the exact conservation of its relative position with respect to Q and S (FIG. 2), the consistent presence of a possible splice acceptor and of a consensus AUG initiator codon, its similar codon usage with respect to viral genes, and finally the fact that the variation of its protein sequence within the different isolates is comparable to that of gag, pol and Q (see FIG. 4).
Also conserved are the sizes of the U3, R and
U5 elements of the LTR (data not shown), the location and sequence of their regulatory elements such as TATA box and AATAAA polyadenylation signal, and their flanking sequences, i.e., primer binding site (hereinafter "PBS") complementary to 3' end of tRNA LYS and polypurine tract (hereinafter "PPT"). Most of the genetic variability within the LTR is located in the 5' half of U3 (which encodes a part of orf F) while the 3' end of U3 and R, which carry most of the cis-acting regulatory elements, promoter, enhancer and trans-activating factor receptor Rosen et al., 1985!, as well as the U5 element, are well-conserved.
Overall, it clearly appears that this Zairian isolate, LAV MAL , is the same type of retrovirus as the previously sequenced isolates of American or European origin.
Variability of the Viral Proteins.
Despite their identical genetic organization, the LAV ELI and LAV MAL shows substantial differences in the primary structure of their proteins. The amino acid sequences of LAV ELI and LAV MAL proteins are presented in FIGS. 3A-3F, aligned with those of LAV BRU and ARV 2. Their divergence was quantified as the percentage of amino acids substitutions in two-by-two alignments (FIG. 4). The number of insertions and deletions that had to be introduced in each of these alignments has also been scored.
Three general observations can be made. First, the protein sequences of the LAV ELI and LAV ELI are more divergent from LAV BRU than are those of HTLV-3 and ARV 2 (FIG. 4A); similar results are obtained if ARV 2 is taken as reference (not shown). The range of genetic polymorphism between isolates of the AIDS virus is considerably greater than previously observed. Second, our two sequences confirm that the envelope is more variable than the gag and pol genes. Here again, the relatively small difference observed between the env of LAV BRU and HTLV-3 appears as an exception. Third, the mutual divergence of the LAV ELI and LAV MAL (FIG. 4B) is comparable to that between LAV BRU and either of them; as far as we can extrapolate from only three sequenced isolates from the USA and Europe and two (LAV ELI and LAV MAL ) from Africa, this is indicative of a wider evolution of the AIDS virus in Africa.
gag and pol Their greater degree of conservation compared to the envelope is consistent with their encoding important structural or enzymatic activities. Of the three mature gag proteins, the p25 which was the first recognized immunogenic protein of LAV Barre-Sinoussi et al., 1983) is also the better conserved (FIG. 3). In gag and pol, differences between isolates are principally due to point mutations, and only a small number of insertional or deletional events is observed. Among these, we must note the presence in the overlapping part of gag and pol of LAV BRU of an insertion of 12 amino acids (AA) which is encoded by the second copy of a 36 bp direct repeat present only in this isolate and in HTLV-3. This duplication was omitted because of a computing error in the published sequence of LAV BRU (position 1712, Wain-Hobson et al., 1985) but was indeed present in the HTLV-3 sequences Ratner et al., 1985 Muesing et al., 1985!.
env: Three segments can be distinguished in the envelope glycoprotein precursor Allan et al., 1985; Montagnier et al., 1985; DiMarzoVeronese et al., 1985!. The first is the signal peptide (positions 1-33 in FIG. 3), and its sequence appears as variable; the second segment (pos. 34-530) forms the outer membrane protein (hereinafter "OMP" or "gp110") and carries most of the genetic variations, and in particular almost all of the membrane. A better conservation of the TMP than the OMP has also been observed between the different murine leukemia viruses (hereinafter "MLV") Koch et al., 1983! and could be due to structural constraints.
From the alignment of FIG. 3 and the graphical representation of the envelope variability shown in FIG. 5, we clearly see the existence of conserved domains, with little or no genetic variation, and hypervariable domains, in which even the alignment of the different sequences is very difficult, because of the existence of a large number of mutations and of reciprocal insertions and deletions. We have not included the sequence of the envelope of the HTLV-3 isolate since it so close to that of LAV RU (cf. FIG. 4), even in the hypervariable domains, that it did not add anything to the analysis. While this graphical representation will be refined by more sequence data, the general profile is already apparent, with three hypervariable domains (Hyl, 2 and 3) all being located in the OMP and separated by three well-conserved stretches (residues 37-130, 211-289, and 488-530 of FIG. 3 alignment) probably associated with important biological functions.
In spite of the extreme genetic variability, the folding pattern of the envelope glycoprotein is probably constant. Indeed the position of virtually all of the cysteine residues is conserved within the different isolates (FIGS. 3 and 5), and the only three variable cysteines fall either in the signal peptide or in the very C-terminal part of the TMP. The hypervariable domains of the OMP are bounded by conserved cysteines, suggesting that they may represent loops attached to the common folding pattern. Also the calculated hydropathic profiles Kyte and Doolittle, 1982! of the different envelope proteins are remarkably conserved (not shown).
About half of the potential N-glycosylation sites, Asn-X-Ser/Thr, found in the envelopes of the Zairian isolates map to the same positions in LAV BRU (17/26 for LAV ELI and 17/28 for LAV MAL ). The other sites appear to fall within variable domains of env, suggesting the existence of differences in the extent of envelope glycosylation between different isolates. Other viral proteins : Of the three other identified viral proteins, the p27 encoded by orf F, 3' of env Allan et al., 1985b! is the most variable (FIG. 4). The proteins encoded by orfs Q and S of the central region are remarkable by their absence of insertions/deletions. Surprisingly, a high frequency of amino acids substitutions, comparable to that observed in env, is found for the product of orf S (trans-activating factor). On the other hand, the protein encoded by orf Q is no more variable than gag. Also noticeable is the lower variation of the proteins encoded by the central regions of LAV ELI and LAV MAL .
With the availability of the complete nucleotide sequence from five independent isolates, some general features of the AIDS virus' genetic variability are now emerging. Firstly, its principal cause is point mutations which very often result in amino acid substitutions and which are more frequent in the 3' part of the genome (orf S, env and orf F). Like all RNA viruses, the retroviruses are thought to be highly subject to mutations caused by errors of the RNA polymerases during their replication, since there is no proofreading, of this step Holland et al., 1982; Steinhauer and Holland, 1986!.
Another source of genetic diversity is insertions/deletions. From the FIG. 3 alignments, insertional events seem to be implicated in most of the cases, since otherwise deletions should have occurred in independent isolates at precisely the same locations. Furthermore, upon analyzing these insertions, we have observed that they most often represent one of the two copies of a direct repeat (FIG. 6). Some are perfectly conserved like the 36 bp repeat in the gag-pol overlap of LAV BRU (FIG. 6-a); others carry point mutations resulting in amino acid substitutions, and as a consequence, they are more difficult to observe, though clearly present, in the hypervariable domains of env (cf. FIG. 6-g and -h). As noted for point mutations, env gene and orf F also appear as more susceptible to that form of genetic variation than the rest of the genome. The degree of conservation of these repeats must be related to their date of occurrence in the analyzed sequences: the more degenerated, the more ancient. A very recent divergence of LAV BRU and HTLV-3 is suggested by the extremely low number of mismatched AA between their homologous proteins. However, one of the LAV BRU repeats (located in the Hyl domain of env, FIG. 6-f) is not present in HTLV-3, indicating that this generation of tandem repeats is a rapid source of genetic diversity. We have found no traces of such a phenomenon, even when comparing very closely related viruses, such as the Mason-Pfizer monkey virus (hereinafter "MPMV") Sonigo et al., 1986!, and an immunosuppressive simian virus (hereinafter "SRV-1") Power et al., 1986!. Insertion or deletion of one copy of a direct repeat have been occasionally reported in mutant retroviruses Shimotohno and Temin, 1981; Darlix, 1986!, but the extent to which we observe this phenomenon is unprecedented. The molecular basis of these duplications is unclear, but could be the "copy-choice" phenomenon, resulting from the diploidy of the retroviral genome varmus and Swanstrom, 1984; Clark and Mak, 1983!. During the synthesis of the firststrand of the viral DNA, jumps are known to occur from one RNA molecule to another, especially when a break or a stable secondary structure is present on the template; an inaccurate re-initiation on the other RNA template could result in the generation (or the elimination) of a short direct repeat.
Genetic variability and subsequent antigenic modifications have often been developed by microorganisms as a means for avoiding the host's immune response, either by modifying their epitopes during the course of the infection, as in trypanosomes Borst and Cross, 1982!, or by generating a large repertoire of antigens, as observed in influenza virus (Webster et al., 1982!. As the human AIDS virus is related to animal lentiviruses Sonigo et al., 1985; Chiu et al., 1985!, its genetic variability could be a source of antigenic variation, as can be observed during the course of the infection by the ovine lentivirus visna Scott et al., 1979; Clements et al., 1980! or by the equine infectious anemia virus (hereinafter "EIAV") Montelaro et al., 1984!. However, a major discrepancy with these animal models is the extremely low, and possibly non-existant, neutralizing activity of the sera of individuals infected by the AIDS virus, whether they are healthy carriers, displaying minor symptoms, or afflicted with AIDS Weiss et al., 1985; Clavel et al., 1985!. Furthermore, even for the visna virus the exact role of antigenic variation in the pathogenesis is unclear Thormar et al., 1983; Lutley et al., 1983!. We rather believe that genetic variation represents a general selective advantage for lentiviruses by allowing an adaptation to different environments, for example by modifying their tissue or host tropisms. In the particular case of the AIDS virus, rapid genetic variations are tolerated, especially in the envelope. This could allow the virus to become adapted to different "micro-environments" of the membrane of their principal target cells, namely the T4 lymphocytes. These "micro-environments" could result from the immediate vicinity of the virus receptor to polymorphic surface proteins, differing either between individuals or between clones of lymphocytes.
Conserved Domains in the AIDS Virus Envelope
Since the proteins of most of the isolates are antigenically cross-reactive, the genotypic differences do not seem to affect the sensitivity of actual diagnostic tests, based upon the detection of antibodies to the AIDS virus and using purified virions as antigens. They nevertheless have to be considered for the development of the "second-generation" tests, that are expected to be more specific, and will use smaller synthetic or genetically-engineered viral antigens. The identification of conserved domains in the highly immunogenic envelope glycoprotein and the core structural proteins (gag) is very important for these tests. The conserved stretch found at the end of the OMP and the beginning of the TMP (490-620, FIG. 3) could be a good candidate, since a bacterial fusion protein containing this domain was well-detected by AIDS patients' sera Chang et al., 1985!.
The envelope, specifically the OMP, mediates the interaction between a retrovirus and its specific cellular receptor DeLarco and Todaro, 1976; Robinson et al., 1980!. In the case of the AIDS virus, in vitro binding assays have shown the interaction of the envelope glycoprotein gpllO with the T4 cellular surface antigen McDougal et al., 1986!, already thought to be closely associated with the virus receptor Klatzmann et al., 1984; Dagleish et al., 1984!. Identification of the AIDS virus envelope domains that are responsible for this interaction (receptor-binding domains) appears to be fundamental for understanding of the host-viral interactions and for designing a protective vaccine, since an immune response against these epitopes could possibly elicit neutralizing antibodies. As the AIDS virus receptor is at least partly formed of a constant structure, the T4 antigen, the binding site of the envelope is unlikely to be exclusively encoded by domains undergoing drastic genetic changes between isolates, even if these could be implicated in some kind of an "adaptation". One or several of the conserved domains of the OMP (residues 37-130, 211-289, and 488-530 of FIG. 3 alignment), brought together by the folding of the protein, must play a part in the virus-receptor interaction, and this can be explored with synthetic or genetically-engineered peptides derived from these domains, either by direct binding assays or indirectly by assaying the neutralizing activity of specific antibodies raised against them.
African AIDS Viruses
Zaire and the neighbouring countries of Central Africa are considered as an area endemic with the AIDS virus infection, and the possibility that the virus has emerged in Africa has became a subject of intense controversy (see Norman, 1985). From the present study, it is clear that the genetic organization of Zairian isolates is the same as that of american isolates, thereby indicating a common origin. The very important sequence differences observed between the proteins are consistent with a divergent evolutionary process. In addition, the two African isolates are mutually more divergent than the American isolates already analyzed; as far as that observation can be extrapolated, it suggests a longer evolution of the virus in Africa and is also consistent with the fact that a larger fraction of the population is exposed than in developed countries.
A novel human retrovirus with morphology and biologocal properties (cytopathogenicity, T4 tropism) similar to those of LAV, but nevertheless clearly genetically and antigenically distinct from it, was recently isolated from two patients with AIDS originating from Guinea Bissau, West-Africa Clavel et al., 1986!. In neighboring Senegal, the population was seemingly exposed to a retrovirus also distinct from LAV but apparently non-pathogenic (Barin et al., 1985; Kanki et al., 1986). Both of these novel African retroviruses seem to be antigenically related to the simian T-cell lymphotropic virus (hereinafter "STLV-III") shown to be widely present in healthy African green monkeys and other simian species Kanki et al. 1985!. This raises the possibility of a large group of African primate lentiviruses, ranging from the apparently non-pathogenic simian viruses to the LAV-type viruses. Their precise relationship will only be known after their complete genetic characterization, but it is already very likely that they have evolved from a common progenitor. The important genetic variability we have observed between isolates of the AIDS virus in Central Africa is probably a hallmark of this entire group and may account for the apparently important genetic divergence between its members (loss of cross-antigenicity in the envelopes). In this sense, the conservation of the tropism for the T4 lymphocytes suggests that it is a major advantage aquired by these retroviruses.
EXPERIMENTAL PROCEDURES
Virus Isolation
LAV MAL was isolated from the peripheral blood lymphocytes of the patient as described Barre-Sinoussi et al., 1983!. Briefly, the lymphocytes were fractionated and co-cultivated with phytohaemagglutinin-stimulated normal human lymphocytes in the presence of interleukin 2 and anti-alpha interferon serum. Viral production was assessed by cell-free reverse transcriptase (hereinafter "RT") activity assay in the cultures and by electron microscopy.
Molecular Cloning
Normal donor lymphocytes were acutely infected (10 4 cpm of RT activity/10 6 cells) as described Barre-Sinoussi et al., 1983!, and total DNA was extracted at the beginning of the RT activity peak. A lambda library using the L47-1 vector Loenen and Brammar, 1982! was constructed by partial HindIII digestion of the DNA as already described Alizon et al., 1984!. DNA from infected cells was digested to completion with HindIII, and the 9-10 kb fraction was selected on 0.8% low melting point agarose gel and ligated into L47-1 HindIII arms. About 2×10 5 plaques for LAV MAL , obtained by in vitro packaging (Amersham), were plated on E. coli LA101 and screened in situ under stringent conditions,using the 9 kb SacI insert of the clone lambda J19 Alizon et al., 1984! carrying most of the LAV BRU genome as probe. Clones displaying positive signals were plaque-purified and propagated on E. coli C600 recBC, and the recombinant phage M-H11 carrying the complete genetic information of LAV MAL was further characterized by restriction mapping.
Nucleotide Sequence Strategy
Viral fragments derived from M-H11 were sequenced by the dideoxy chain terminator procedure Sanger et al., 1977! after "shotgun" cloning in the M13mp8 vector Messing and Viera, 1982! as previously described Sonigo et al., 1985!. The viral genome of LAV MAL is 9229 nucleotides long as shown in FIGS. 7A-7I. Each nucleotide of LAV ML was determined from more than 5 independent clones on average.
Significance of the Figures
FIG. 1 contains an analysis of AIDS virus isolates, showing:
A/ Restriction maps of the inserts of phage lambda clones derived from cells infected with LAV ELI (hereinafter "E-H12") and with LAV MAL (M-H11). The schematic genetic organization of the AIDS virus has been drawn above the maps. The LTRs are indicated by solid boxes. Restriction sites are indicated as follows: A: Aval; B: BamHI; Bg: BG1II; E: EcoRI; H: HindIII; Hc: HincII; K: KpnI; N: NdeI; P: PstI; S: SacI; and X: XbaI. Asterisks indicate the HindIII cloning sites in lambda L47-1 vector.
B/ A comparison of the sites for seven restriction enzymes in six isolates : the prototype AIDS virus LAV BRU LAV MAL and LAV ELI ; and Z1, Z2 and Z3. Restriction sites are represented by the following symbols vertically aligned wih the symbols in FIG. 1A : : BgIII; * :EcoRI; ∇:HincII; ▾:HindIII; ♦:KpnI; ⋄:NdeI; and o: SacI.
FIG. 2 shows the genetic organization of the central region in AIDS virus isolates. Stop codons in each phase are represented as vertical bars. Vertical arrows indicate possible AUG initiation codons. Splice acceptor (A) and donor (D) sites identified in subgenomic viral mRNA Muesing et al., 1985! are shown below the graphic of LAV BRU , and corresponding sites in LAV ELI and LAV MAL are indicated. PPT indicates the repeat of the polypurine tract flanking the 3'LTR. As observed in LAV BRU Wain-Hobson et al., 19851!, the PPT is repeated 256 nucleotides 5' to the end of the pol gene in both the ELV EAI and LAV MAL sequences, but this repeat is degenerated at two positions in LAV ELI .
FIG. 3 shows an alignment of the protein sequences of four AIDS virus isolates. Isolate LAV BRU Wain-Hobson et al., 1985! is taken as reference; only differences with LAV BRU are noted for ARV 2 Sanchez-Pescador et al., 1985! and the two Zairian isolates LAV MAL and LAV ELI . A minimal number of gaps (-) were introduced in the alignments. The NH 2 -termini of p 25 gag and p18gag are indicated Sanchez-Pescador, 1985!. The potential cleavage sites in the envelope precursor Allan et al., 1985a; diMarzoVeronese, 1985! separating the signal peptide (hereinafter "SP"), OMP and TMP are indicated as vertical arrows; conserved cysteines are indicated by black circles and variable cysteines are boxed. The one letter code for each amino acid is as follows: A:Ala C:Cys; D:Asp; E:Glu; F:Phe; G:Gly; H :His; I:Ile K:Lys; L:Leu; M:Met; N:Asn; P:Pro; Q:Gln; R:Arg S:Ser; T:Thr; V:Val; W:Trp; Y:Tyr.
FIG. 4 shows a quantitation of the sequence divergence between homologous proteins of different isolates. Part A of each table gives results deduced from two-by-two alignments using the proteins of LAV BRU as reference, part B, those of LAV ELI as reference. Sources: Muesing et al., 1985 for HTLV-3; Sanchez-Pescador et al., 1985 for ARV 2 and Wain-Hobson et al., 1985 for LAV BRU . For each case in the tables, the size in amino acids of the protein (calculated from the first methionine residue or from the beginning of the orf for pol) is given at the upper left part. Below are given the number of deletions (left) and insertions (right) necessary for the alignment. The large numbers in bold face represent the percentage of amino acids substitutions (insertions/deletions being excluded). Two by two alignments were done with computer assistance Wilburg and Lipman, 1983!, using a gag penalty of 1, K-tuple of 1, and window of 20, except for the hypervariable domains of env, where the number of gaps was made minimum, and which are essentially aligned as shown in FIG. 3. The sequence of the predicted protein encoded by orf R of HTLV-3 has not been compared because of a premature termination relative to all other isolates.
FIG. 5 shows the variability of the AIDS virus envelope protein. For each position x of the alignment of env (FIG. 3), variability V(x) was calculated as: V(x)=number of different amino-acids at position x/ frequency of the most abundant amino acid at position x. Gaps in the alignments are considered as another amino acid. For an alignment of 4 proteins, V(x) ranges from 1 (identical AA in the 4 sequences) to 16 (4 different AA). This type of representation has previously been used in a compilation of the AA sequence of immunoglobulins variable regions Wu and Kabat, 1970!. Vertical arrows indicate the cleavage sites; asterisks represent potential N-glysosylation sites (N-X-S/T) conserved in all three four isolates; black triangles represent conserved cysteine residues. Black lozanges mark the three major hydrophobic domains: OMP, TMP and SP; and the hypervariable domains: Hy1, 2 and 3.
FIG. 6 shows the direct repeats in the proteins of different AIDS virus isolates. These examples are derived from the aligned sequences of gag (a, b), F (c,d) and env (e, f, g, h) shown in FIG. 3. The two elements of the direct repeat are boxed, while degenerated positions are underlined.
FIGS. 7A-7I show the complete cDNA sequence of LAV MAL of this invention.
The invention thus pertains more specifically to the proteins, glycoproteins and other polypeptides including the polypeptide structures shown in the FIGS. 1-7. The first and last amino acid residues of these proteins, glycoproteins and polypeptides carry numbers computed from a first amino acid of the open-reading frames concerned, although these numbers do not correspond exactly to those of the LAV MAL proteins concerned, rather to the corresponding proteins of the LAV BRU or sequences shown in FIGS. 3A, 3B and 3C. Thus a number corresponding to a "first amino acid residue" of a LAV MAL protein corresponds to the number of the first amino-acyl residue of the corresponding LAV BRU protein which, in any of FIGS. 3A, 3B or 3C, is in direct alignment with the corresponding first amino acid of the LAV MAL protein. Thus the sequences concerned can be read from FIGS. 7A-7I to the extent where they do not appear with sufficient clarity from FIGS. 3A-3F.
The preferred protein sequences of this invention extend between the corresponding "first" and "last" amino acid residues. Also preferred are the protein(s)-- or glycoprotein(s)--portions including part of the sequences which follow
OMP or gp110 proteins, including precursors: 1 to 530
OMP or gp110 without precursor: 34-530
Sequence carrying the TMP or gp41 protein: 531-877, particularly 680-700
well conserved stretches of OMP: 37-130, 211-289 and 488-530
well conserved stretch found at the end of the OMP and the beginning of TMP: 490-620.
Proteins containing or consisting of the "well conserved stretches" are of particular interest for the production of immunogenic compositions and (preferably in relation to the stretches of the env protein) of vaccine compositions against the LAV-1 viruses.
The invention concerns more particularly all the DNA fragments which have been more specifically referred to in the drawings and which correspond to open reading frames. It will be understood that one skilled in the art will be able to obtain them all, for instance by cleaving an entire DNA corresponding to the complete genome of LAV MAL , such as by cleavage by a partial or complete digestion thereof with a suitable restriction enzyme and by the subsequent recovery of the relevant fragments. The DNA disclosed above can be resorted to also as a source of suitable fragments. The techniques disclosed in PCT application for the isolation of the fragments which can then be included in suitable plasmids are applicable here too. Of course, other methods can be used, some of which have been exemplified in European Application No. 178,978, filed Sep. 17, 1985. Reference is for instance made to the following methods:
a) DNA can be transfected into mammalian cells with appropriate selection markers by a variety of techniques, such as calcium phosphate precipitation, polyethylene glycol, protoplast-fusion, etc.
b) DNA fragments corresponding to genes can be cloned into expression vectors for E. coli, yeast- or mammalian cells and the resultant proteins purified.
c) The provival DNA can be "shot-gunned" (fragmented) into procaryotic expression vectors to generate fusion polypeptides. Recombinants, producing antigenically competent fusion proteins, can be identified by simply screening the recombinants with antibodies against LAV antigens.
The invention further refers to DNA recombinants, particularly modified vectors, including any of the preceding DNA sequences adapted to transform corresponding microorganisms or cells, particularly eucaryotic cells such as yeasts, for instance Saccharomyces cerevisiae, or higher eucaryotic cells, particularly cells of mammals, and to permit expression of said DNA sequences in the corresponding microorganisms or cells. General methods of that type have been recalled in the abovesaid PCT international patent aplication PCT/EP 85/00548, filed Oct. 18, 1985.
More particularly the invention relates to such modified DNA recombinant vectors modified by the abovesaid DNA sequences and which are capable of transforming higher eucaryotic cells particularly mammalian cells. Preferably, any of the abovesaid sequences are placed under the direct control of a promoter contained in said vectors and recognized by the polymerases of said cells, such that the first nucleotide codons expressed correspond to the first triplets of the above-defined DNA sequences. Accordingly, this invention also relates to the corresponding DNA fragments which can be obtained from the genome of LAV MAL or its cDNA by any appropriate method. For instance, such a method comprises cleaving said LAV MAL genome or its cDNA by restriction enzymes preferably at the level of restriction sites surrounding said fragments and close to the opposite extremities respectively thereof, recovering and identifying the fragments sought according to sizes, if need be checking their restriction maps or nucleotide sequences (or by reaction with monoclonal antibodies specifically directed against epitopes carried by the polypeptides encoded by said DNA fragments), and further if need be, trimming the extremities of the fragment, for instance by an exonucleolytic enzyme such as Bal31, for the purpose of controlling the desired nucleotidsequences of the extremities of said DNA fragments or, conversely, repairing said extremities with Klenow enzyme and possibly ligating the latter to synthetic polynucleotide fragments designed to permit the reconstitution of the nucleotide extremities of said fragments. Those fragments may then be inserted in any of said vectors for causing the expression of the corresponding polypeptide by the cell transformed therewith. The corresponding polypeptide can then be recovered from the transformed cells, if need be after lysis thereof, and purified by methods such as electrophoresis. Needless to say, all conventional methods for performing these operations can be resorted to.
The invention also relates more specifically to cloned probes which can be made starting from any DNA fragment according to this invention, thus to recombinant DNAs containing such fragments, particularly any plasmids amplifiable in procaryotic or eucaryotic cells and carrying said fragments. Using the cloned DNA fragments as a molecular hybridization probe - either by labelling with radionucleotides or with fluorescent reagents--LAV virion RNA may be detected directly in the blood, body fluids and blood products (e.g. of the antihemophylic factors such as Factor VIII concentrates) and vaccines (e.g., hepatitis B vaccine). It has already been shown that whole virus can be detected in culture supernatants of LAV producing cells. A suitable method for achieving that detection comprises immobilizing virus on a support (e.g., a nitrocellulose filter), disrupting the virion and hybridizing with labelled (radiolabelled or "cold" fluorescent- or enzyme-labelled) probes. Such an approach has already been developed for Hepatitis B virus in peripheral blood SCOTTO J. et al. Hepatology (1983), 3, 379-384!.
Probes according to the invention can also be used for rapid screening of genomic DNA derived from the tissue of patients with LAV related symptoms, to see if the proviral DNA or RNA present in host tissue and other tissues can be related to that of LAV MAL .
A method which can be used for such screening comprises the following steps: extraction of DNA from tissue, restriction enzyme cleavage of said DNA, electrophoresis of the fragments and Southern blotting of genomic DNA from tissues, subsequent hybridization with labelled cloned LAV proviral DNA. Hybridization in situ can also be used.
Lymphatic fluids and tissues and other nonlymphatic tissues of humans, primates and other mammalian species can also be screened to see if other evolutionnary related retrovirus exist. The methods referred to hereinabove can be used, although hybridization and washings would be done under non-stringent conditions.
The DNAs or DNA fragments according to the invention can be used also for achieving the expression of viral antigens of LAV MAL for diagnostic purposes.
The invention relates generally to the polypeptides themselves, whether synthesized chemically, isolated from viral preparations or expressed by the different DNAs of the invention, particularly by the ORFs or fragments thereof in appropriate hosts, particularly procaryotic or eucaryotic hosts, after transformation thereof with a suitable vector previously modified by the corresponding DNAs.
More generally, the invention also relates to any of the polypeptide fragments (or molecules, particularly glycoproteins having the same polypeptidic backbone as the polypeptides mentioned hereinabove) bearing an epitope characteristic of a protein or glycoprotein of LAV MAL , which polypeptide or molecule then has N-terminal and C-terminal extremities, respectively, either free or, independently from each other, covalently bonded to amino acids other than those which are normally associated with them in the larger polypeptides or glycoproteins of the LAV virus, which last mentioned amino acids are then free or belong to another polypeptidic sequence. Particularly, the invention relates to hybrid polypeptides containing any of the epitopebearing-polypeptides which have been defined more specifically hereinabove, recombined with other polypeptides fragments normally foreign to the LAV proteins, having sizes sufficient to provide for an increased immunogenicity of the epitope-bearing-polypeptide yet, said foreign polypeptide fragments either being immunogenically inert or not interfering with the immunogenic properties of the epitope-bearing-polypeptide.
Such hybrid polypeptides, which may contain from 5 up to 150, even 250 amino acids, usually consist of the expression products of a vector which contained, ab initio, a nucleic acid sequence expressible under the control of a suitable promoter or replicon in a suitable host, which nucleic acid sequence had, however, beforehand been modified by insertion therein of a DNA sequence encoding said epitope-bearing-polypeptide.
Said epitope-bearing-polypeptides, particularly those whose N-terminal and C-terminal amino acids are free, are also accessible by chemical synthesis according to techniques well known in the chemistry of proteins.
The synthesis of peptides in homogeneous solution and in solid phase is well known. In this respect, recourse may be had to the method of synthesis in homogeneous solution described by Houbenweyl in the work entitled "Methoden der Organischen Chemie" (Methods of Organic Chemistry) edited by E. WUNSCH., vol. 15-I and II, THIEME, Stuttgart 1974. This method of synthesis consists of successively condensing either the successive amino acids in twos, in the appropriate order or successive peptide fragments previously available or formed and containing already several amino-acyl residues in the appropriate order respectively. Except for the carboxyl and aminogrocips which will be engaged in the formation of the peptide bonds, care must be taken to protect beforehand all other reactive groups borne by these amino-acyl groups or fragments. However, prior to the formation of the peptide bonds, the carboxyl groups are advantageously activated, according to methods well known in the synthesis of peptides. Alternatively, recourse may be had to coupling reactions bringing into play conventional coupling reagents, for instance of the carbodiimide type, such as 1-ethyl-3-(3-dimethyl-amino-propyl)-carbodiimide. When the amino acid group used carries an additional amine group (e.g., lysine) or another acid function (e.g., glutamic acid), these groups may be protected by carbobenzoxy or t-butyloxycarbonyl groups, as regards the amine groups, or by t-butylester groups, as regards the carboxylic groups. Similar procedures are available for the protection of other reactive groups. for example, an -SH group (e.g., in cysteine) can be protected by an acetamidomethyl or paramethoxybenzyl group.
In the case of a progressive synthesis, amino acid by amino acid, the synthesis starts preferably with the condensation of the C-terminal amino acid with the amino acid which corresponds to the neighboring aminoacyl group in the desired sequence and so on, step by step, up to the N-terminal amino acid. Another preferred technique which can be used is that described by R. D. Merrifield in "Solid Phase Peptide Synthesis" J. Am. Chem. Soc., 45:2149-2154!. In accordance with the Merrifield process, the first C-terminal amino acid of the chain is fixed to a suitable porous polymeric resin, by means of its carboxylic group, the amino group of the amino acid then being protected, for example by a t-butyloxycarbonyl group. When the first C-terminal amino acid is thus fixed to the resin, the protective group of the amine group is removed by washing the resin with an acid, i.e., trifluoroacetic acid, when the protective group of the amine group is a t-butyloxycarbonyl group. Then, the carboxylic group of the second amino acid, which is to provide the second amino-acyl group of the desired peptidic sequence, is coupled to the deprotected amine group of the C-terminal amino acid fixed to the resin. 1ferably, the carboxyl group of this second amino acid has been activated, for example by dicyclohexyl-carbodiimide, while its amine group has been protected, for example by a t-butyloxycarbonyl group. The first part of the desired peptide chain, which comprises the first two amino acids, is thus obtained. As previously, the amine group is then deprotected, and one can further proceed with the fixing of the next amino-acyl group and so forth until the whole peptide sought is obtained. The protective groups of the different side groups, if any, of the peptide chain so formed can then be removed. The peptide sought can then be detached from the resin, for example by means of hydrofluoric acid, and finally recovered in pure form from the acid solution according to conventional procedures.
As regards the peptide sequences of smallest size bearing an epitope or immunogenic determinant, and more particularly those which are readily accessible by chemical synthesis, it may be required, in order to increase their in vivo immunogenic character, to couple or "conjugate" them covalently to a physiologically acceptable and non-toxic carrier molecule. By way of examples of carrier molecules or macromolecular supports which can be used for making the conjugates according to the invention can be mentioned natural proteins, such as tetanus toxoid, ovalbumin, serum-albumins, hemocyanins, etc. Synthetic macromolecular carriers, for example polylysines or poly(D-L-alanine)-poly(L-lysine)s, can be used too. Other types of macromolecular carriers that can be used, which generally have molecular weights higher than 20,000, are known from the literature. The conjugates can be synthesized by known processes such as are described by Frantz and Robertson in "rnfect. and Immunity", 33, 193-198 (1981) and by P. E. Kauffman in "Applied and Environmental Microbiology", October 1981 Vol. 42, No. 4, pp. 611-614. For instance, the following coupling agents can be used : glutaric aldehyde, ethyl chloroformate, water-soluble carbodiimides such as(N-ethyl-N'(3-dimethylamino-propyl) carbodiimide, HCl), diisocyanates, bis-diazobenzidine, di- and trichloro-s-triazines, cyanogen bromides and benzaquinone, as well as the coupling agents mentioned in "Scand. J. Immunol.", 1978, vol. 8, pp. 7-23 (Avrameas, Ternynck, Guesdon).
Any coupling process can be used for bonding one or several reactive groups of the peptide, on the one hand, and one or several reactive groups of the carrier, on the other hand. Again coupling is advantageously achieved between carboxyl and amine groups carried by the peptide and the carrier or vice-versa in the presence of a coupling agent of the type used in protein synthesis, e.g., 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide, N-hydroxybenzotriazole, etc. Coupling between amine groups respectively borne by the peptide and the carrier can also be made with glutaraldehyde, for instance, according to the method described by BOQUET, P. et al. (1982) Molec. Immunol., 19, 1441-1549, when the carrier is hemocyanin.
The immunogenicity of epitope-bearing-peptides can also be reinforced by oligomerisation thereof, for example in the presence of glutaraldehyde or any other suitable coupling agent. In particular, the invention relates to the water soluble immunogenic oligomers thus obtained, comprising particularly from 2 to 10 monomer units.
The glycoproteins, proteins and other polypeptides (generally designated hereinafter as "antigens" of this invention) whether obtained by methods, such as are disclosed in the earlier patent applications referred to above, in a purified state from LAV MAL virus preparations or - as concerns more particularly the peptides by chemical synthesis, are useful in processes for the detection of the presence of anti-LAV antibodies in biological media, particularly biological fluids such as sera from man or animal, particularly with a view of possibly diagnosing LAS or AIDS.
Particularly the invention relates to an in vitro process of diagnosis making use of an envelope glycoprotein or of a polypeptide bearing an epitope of this glycoprotein of LAV MAL for the detection of anti-LAV antibodies in the serums of persons who carry them. Other polypeptides--particular those carrying an epitope of a core protein--can be used too.
A preferred embodiment of the process of the invention comprises:
depositing a predetermined amount of one or several of said antigens in the cups of a titration microplate;
introducing increasing dilutions of the biological fluid, to be diagnosed (e.g., blood serum, spinal fluid, lymphatic fluid, and cephalo-rachidian fluid), into these cups;
incubating the microplate;
washing carefully the microplate with an appropriate buffer;
adding into the cups specific labelled antibodies directed against blood immunoglobulins and
detecting the antigen-antibody-complex formed, which is then indicative of the presence of LAV antibodies in the biological fluid.
Advantageously the labelling of the anti-immunoglobulin antibodies is achieved by an enzyme selected from among those which are capable of hydrolysing a substrate, which substrate undergoes a modification of its radiation-absorption, at least within a predetermined band of wavelenghts. The detection of the substrate, preferably comparatively with respect to a control, then provides a measurement of the potential risks, or of the effective presence, of the disease.
Thus, preferred methods of immuno-enzymatic and also immunofluorescent detections, in particular according to the ELISA technique, are provided. Titrations may be determinations by immunofluorescence or direct or indirect immuno-enzymatic determinations. Quantitative titrations of antibodies on the serums studied can be made.
The invention also relates to the diagnostic kits themselves for the in vitro detection of antibodies against the LAV virus, which kits comprise any of the polypeptides identified herein and all the biological and chemical reagents, as well as equipment, necessary for peforming diagnostic assays. Preferred kits comprise all reagents required for carrying out ELISA assays. Thus preferred kits will include, in addition to any of said polypeptides, suitable buffers and anti-human immunoglobulins, which anti-human immunoglobulins are labelled either by an immunofluorescent molecule or by an enzyme. In the last instance, preferred kits also comprise a substrate hydrolysable by the enzyme and providing a signal, particularly modified absorption of a radiation, at least in a determined wavelength, which signal is then indicative of the presence of antibody in the biological fluid to be assayed with said kit.
It can of course be of advantage to use several proteins or polypeptides not only of LAV MA L but also of LAV EL I together with homologous proteins or polypeptides of earlier described viruses, such as LAV BR U, HTLV-3, ARV 2, etc.
The invention also relates to vaccine compositions whose active principle is to be constituted by any of the antigens, i.e., the hereinabove disclosed polypeptides of LAV MA L, particularly the purified gp110 or immunogenic fragments thereof, fusion polypeptides or oligopeptides in association with a suitable pharmaceutically or physiologically acceptable carrier. A first type of preferred active principle is the gp110 immunogen of said immunogens. Other preferred active principles to be considered in that fields consist of the peptides containing less than 250 amino acid units, preferably less than 150, particularly from 5 to 150 amino acid residues, as deducible for the complete genome of LAV MAL and even more preferably those peptides which contain one or more groups selected from Asn-X-Thr and Asn-X-Ser as defined above. Preferred peptides for use in the production of vaccinating principles are peptides (a) to (f) as defined above. By way of example, there may be mentioned that suitable dosages of the vaccine compositions are those which are effective to elicit antibodies in vivo, in the host, particularly a human host. Suitable doses range from 10 to 500 micrograms of polypeptide, protein or glycoprotein per kg, for instance 50 to 100 micrograms per kg.
The different peptides according to this invention can also be used themselves for the production of antibodies, preferably monoclonal antibodies specific for the respective different peptides. For the production of hybridomas secreting said monoclonal antibodies, conventional production and screening methods can be used. These monoclonal antibodies, which themselves are part of the invention, provide very useful tools for the identification and even determination of relative proportions of the different polypeptides or proteins in biological samples, particularly human samples containing LAV or related viruses.
The invention further relates to the hosts (procaryotic or eucaryotic cells) which are transformed by the above mentioned recombinants and which are capable of expressing said DNA fragments.
Finally the invention also concerns vectors for transforming eucaryotic cells of human origin, particularly lymphocytes, the polymerase of which are capable of recognizing the LTRs of LAV. Particularly said vectors are characterized by the presence of a LAV LTR therein, said LTR being then active as a promoter enabling the efficient transcription and translation in a suitable host of a DNA insert coding for a determined protein placed under its controls.
Needless to say, the invention extends to all variants of genomes and corresponding DNA fragments (ORFs) having substantially equivalent properties, all of said genomes belonging to retroviruses which can be considered as equivalents of LAV MA L. It must be understood that the claims which follow are also intended to cover all equivalents of the products (glycoproteins, polypeptides, DNAs, etc.) whereby an equivalent is a product, e.g., a polypeptide, which may distinguish from a product defined in any of said claims, say through one or several amino acids, while still having substantially the same immunological or immunogenic properties. A similar rule of equivalency shall apply to the DNAs, it being understood that the rule of equivalency will then be tied to the rule of equivalency pertaining to the polypeptides which they encode.
It will also be understood that all the literature referred to hereinbefore and hereinafter and all patent applications and patents not specifically identified herein but which form counterparts of those specifically designated herein, must be considered as incorporated herein by reference.
It should further be mentioned that the invention further relates to immunogenic compositions that contain preferably one or more of the polypeptides, which are specifically identified above and which have the amino acid sequences of LAV MAL that have been identified, or peptide sequences corresponding to previously defined LAV proteins. In this respect, the invention relates more particularly to the particular polypeptides which have the sequences corresponding more specifically to the LAV BR U sequences which have been referred to earlier, i.e., the sequences extending between the following first and last amino acids, of the LAV BRU proteins themselves, i.e., the polypeptides having sequences contained in the LAV BR U OMP or LAV BRU TMP or sequences extending over both, particularly those extending from between the following positions of the amino acids included in the env open reading frame of the LAV BR U genome,
1-530
34-530
and more preferably
531-877, particularly 680-700,
37-130
211-289
488-530
490-620.
These different sequences can be used for any of the above defined purposes and in any of the compositions which have been disclosed.
Finally the invention also relates to the different antibodies which can be formed specifically against the different peptides which have been disclosed herein, particularly to the monoclonal antibodies which recognize them specifically. The corresponding hybridomas which can be formed starting from spleen cells previously immunized with such peptides which are fused with appropriate myeloma cells and selected according to standard procedures also form part of the invention.
Phage λ clone E-H12 derived from LAV ELI infected cells has been deposited at the CNCM under No. I-550 on May 9, 1986. Phage clone M-H11 derived from LAV MA L infected cells has been deposited at the CNCM under No. I-551 on May 9, 1986.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method of analyzing materials, and more particularly, to a method of accurately measuring the effective temperature inside a sealed container, such as a headspace vial.
BACKGROUND OF THE INVENTION
[0002] The technique of equilibrium headspace extraction involves placing a liquid or solid sample into a suitable sealed vial and allowing volatile analytes within the sample to reach equilibration in concentration between the sample matrix and the vapor above it (i.e., the headspace). A fixed volume of the vapor is then transferred to a gas chromatograph for analysis. At equilibration, the concentration of each analyte in the headspace is defined by the amount of the analyte present, the volumes of the two phases and the partition coefficient for that analyte between the two phases. The partition coefficient, which is a thermodynamic property, is highly dependent on temperature and so must be carefully controlled within the instrumentation if good analytical precision is to be achieved.
[0003] Current state-of-the-art headspace samplers, such as the model TurboMatrix Automatic Headspace Sampler distributed by PerkinElmer Instruments LLC, are designed to maintain a very stable vial temperature by making use of a large thermostatted metal oven block. However, despite the fact that stable vial temperatures can be maintained, a number of issues regarding temperature control remain.
[0004] For example, the true temperature of the vial may not be accurately measured. The electronic sensor used to monitor temperature is typically located within a heating belt that surrounds the oven block and is remote from the vial. As such, the temperature reading may not reflect the true vial temperature at all settings. Moreover, it is possible that all vial positions may not be at the same temperature.
[0005] Another issue may arise when a new (cold) vial is inserted into the oven block. In such a case, there may be a drop in temperature in one or more of the other vials which cannot be readily detected using known methods. Furthermore, known methods of temperature measurement may not take into account the fact that the vial temperature may change over time.
[0006] Another potential issue is that certain requirements, such as GLP (Good Laboratory Practices) certification standards and FDA (Food and Drug Administration) approval requirements, may require that the vial temperature be monitored and/or calibrated.
[0007] In addition, some instruments which are not state-of-the-art may be weak in the area of vial temperature control. As such, it may be desirable to evaluate the performance of such instruments using a simple method for temperature measurement.
[0008] Traditionally, a thermocouple or similar temperature-measuring probe would be inserted into the vial. However, this technique is tedious to perform, interrupts the normal operation of the instrument, and requires special tools. Moreover, taking a reading from a single point inside the vial may not truly reflect the “effective” temperature of the whole vial. Instead, it would be more desirable to make use of a suitable sample in a vial and use chromatography to determine temperature—after all, it is this process for which standardization is being attempted.
[0009] What is desired, therefore, is a method of measuring the effective temperature inside a sealed container which accurately reflects the true container temperature at all instrument settings, which takes into account temperature variations across various container positions, which measures the temperature of each container separately from other containers when a plurality of containers are used, which takes into account the fact that the container temperature may change over time, which allows for temperature calibration, which can be used to evaluate the temperature control performance of an instrument, which is easy to perform, which does not interrupt the normal operation of the instrument, which does not require special tools, and which uses chromatography to determine temperature.
SUMMARY OF THE INVENTION
[0010] Accordingly, it is an object of the present invention to provide a method of measuring the effective temperature inside a sealed container which accurately reflects the true container temperature at all instrument settings.
[0011] Another object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which takes into account temperature variations across various container positions.
[0012] A further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which measures the temperature of each container separately from other containers when a plurality of containers are used.
[0013] Still another object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which takes into account the fact that the container temperature may change over time.
[0014] Yet a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which allows for temperature calibration.
[0015] Still a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which can be used to evaluate the temperature control performance of an instrument.
[0016] Still a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which is easy to perform.
[0017] Yet another object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which does not interrupt the normal operation of the instrument.
[0018] Still a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which does not require special tools.
[0019] Yet still a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which uses chromatography to determine temperature.
[0020] These and other objects of the present invention are achieved by provision of method of measuring the effective temperature inside a sealed container having a headspace. A liquid solvent is added to the container, and a solid compound is added to the liquid solvent to create a saturated solution. Vapor of the saturated solution is allowed to equilibrate in the headspace of the sealed container, and a volume thereof is transferred to a chromatographic column, where chromatographic readings of the equilibrated vapor are taken. A temperature within the sealed container is then calculated based upon the chromatographic readings of the equilibrated vapor, wherein the temperature calculation is based upon the concentrations of the liquid solvent and the solid compound in the equilibrated vapor.
[0021] Preferably, the chromatographic readings comprise readings of peak areas of the liquid solvent and the solid compound. Most preferably, the calculating step comprises the step of calculating a temperature within the sealed container based upon a ratio of the readings of peak areas of the liquid solvent and the solid compound.
[0022] In one preferred embodiment, the liquid solvent comprises n-dodecane and the solid compound comprises naphthalene. In another embodiment, the liquid solvent comprises n-octadecane and the solid compound comprises anthracene.
[0023] The invention and its particular features and advantages will become more apparent from the following detailed description considered with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a schematic view of a sealed vial for which the temperature can be measured in accordance with the present invention;
[0025] [0025]FIG. 2 is a graphical representation of the ideal vapor pressure behavior for a binary mixture according to Raoult's Law as employed by the present invention;
[0026] [0026]FIG. 3 is a graphical representation of chromatograms of a n-dodecane and naphthalene test mix thermostatted over a range of temperatures which illustrates a portion of the theory underlying the present invention;
[0027] [0027]FIG. 4 is a plot of area ratio (naphthalene/n-dodecane) versus set temperature in ° C. which illustrates a portion of the theory underlying the present invention; and
[0028] [0028]FIG. 5 is a plot of a linear relationship between the areas of naphthalene and n-dodecane which illustrates a portion of the theory underlying the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] In arriving at the present invention, consideration was given to making use of temperature dependence of partition coefficients in order to determine the effective temperature within a vial. In accordance with such a method, a solution of two solutes in a suitable solvent would be prepared. The solutes and solvent would be chosen so that their partition coefficients exhibited different temperature profiles. Their relative concentrations (hence chromatographic peak sizes) would be a measure of the temperature.
[0030] However, it was found that this approach may be undesirable because it would rely on very precise control of concentrations and volumes. Moreover, the compounds would have to be chemically similar so that their relative response factors on the GC detector would be constant, and differences in partition coefficient profiles would therefore be subtle.
[0031] Consideration was also given to making use of temperature dependence of vapor pressures in order to determine the effective temperature within a vial. In accordance with this method, an excess of a suitable compound disposed in a thermostatted headspace vial would saturate the headspace with compound vapor. The concentration of the vapor at the saturation point would be proportional to the vapor pressure. Vapor pressure is dependent upon temperature and so the concentration of vapor in the headspace is temperature dependent. By choosing two compounds with different vapor pressure curves, the ratio of their concentrations (hence chromatographic peak sizes) would be a measure of temperature.
[0032] However, it was found that this approach may be undesirable because when two compounds are mixed together, there is a change to their respective vapor pressures that is concentration dependent and so results are difficult to predict.
[0033] In order to overcome the deficiencies of the prior art and to avoid the concerns expressed with respect to the approaches described above, it was decided upon to make use of temperature dependence of solubility and vapor pressure.
[0034] Referring to FIG. 1, this method relies on the solubility of a solid compound 10 in a suitable liquid solvent. Sufficient solid 10 is added to ensure that a saturated solution 12 is produced. The saturation concentration is highly temperature dependent but should always be the same at any given temperature. This effect will also mean that the concentration of both compound vapors in the headspace 14 inside a sealed vial 16 containing the saturated solution 12 will also be predictable at any given temperature. The compound concentrations in the headspace 14 are now dependent on both liquid solubility and vapor pressure and should give an enhanced temperature effect.
[0035] In one preferred embodiment, naphthalene was chosen as the solid compound and n-dodecane was chosen as the liquid solvent. These compounds were found to be appropriate for a number reasons, such as the fact that they are both hydrocarbons and should give relative response factor reproducibility on all flame ionization detectors. Moreover, n-dodecane becomes saturated with naphthalene at concentrations of approximately 30% at ambient temperature, which simplifies the measuring process. Furthermore, the vapor pressures of pure n-dodecane and pure naphthalene are similar, they are chromatographically-friendly compounds that can be run on almost any column, and their vapor pressure curves are significantly different.
[0036] However, it should be understood that the combination of n-dodecane and naphthalene is not meant to be limiting in any way, and the use of numerous combinations of compounds with the inventive measurement method is contemplated. More specifically, experiments have shown that the use of n-dodecane and naphthalene may be limited to temperatures in the region of about 40 to 70° C. (naphthalene melts at 800° C.). For higher temperatures, other compounds, such a combination of n-octadecane and anthracene, may be used without departing from the present invention.
[0037] The general procedure employed with the present invention involves the following steps. First, a vial containing an approximately 10-90 mix of n-dodecane and naphthalene is placed into a headspace sampler and allowed to thermostat (i.e., typically for about 20 minutes) at the set temperature. Next, a suitable volume of the equilibrated headspace vapor is transferred to a chromatographic column for determination. Finally, the temperature of the headspace vial is derived from the ratio of the two peak areas, as more fully discussed below.
[0038] Theoretical Model
[0039] The vapor pressure of a component in a binary mixture may be conveniently described by Raoult's Law as:
( p 0 - p ) p 0 = x = n 2 ( n 1 + n 2 ) ( 1 )
[0040] Where:
[0041] p 0 is the vapor pressure of the compound in the mixture
[0042] p is the vapor pressure of the pure compound
[0043] x is the mole fraction of the compound in the mixture
[0044] n 1 is the number of moles of the other compound
[0045] n 2 is the number of moles of the compound being studied
[0046] [0046]FIG. 2, which graphically illustrates the ideal vapor pressure behavior for a binary mixture according to Raoult's Law, shows how the relative vapor pressure, hence vapor phase concentration, of each component depends on the concentration of that component in the liquid mixture and the vapor pressure of the pure compound. If the vapor were to be chromatographed, then the peak area ratio for the two compounds would be dependent on both their liquid concentrations and pure vapor pressures.
[0047] The concentration of a saturated solution of naphthalene in n-dodecane is temperature dependent and may again be described by another form of Raoult's Law as:
x = n 2 ( n 1 + n 2 ) = [ - L f R ( T 0 - T T 0 T ) ] ( 2 )
[0048] Where:
[0049] L f is the molar heat of fusion
[0050] R is the gas constant
[0051] T 0 is the compound freezing point absolute temperature
[0052] T is the absolute temperature of the solution
[0053] The dependence of vapor pressure of a pure substance on temperature may be described by the Clapeyron-Clausius Equation as:
p = ( - L v RT + C ) ( 3 )
[0054] Where:
[0055] L v is the molar heat of vaporization
[0056] C is a constant
[0057] It should be noted, however, that in practice, deviations from Equations 1, 2 and 3 may be expected because of inter-molecular forces. Therefore, these relationships should be used only for guidance.
[0058] Equations 1, 2 and 3 may be combined to give Equations 4 or 5, which relate the predicted vapor pressure, p 0 , for a component in a saturated mixture to temperature, T, as follows:
p 0 = ( - L v RT + C ) 1 - [ L f R ( T 0 - T T 0 T ) ] or ( 4 ) p 0 = a · b T 1 - c · d T ( 5 )
[0059] Where:
[0060] a is a constant
[0061] b is a constant
[0062] c is a constant
[0063] d is a constant
[0064] The ratio of the observed vapor pressures would be:
p 0 p 0 ′ = a · b T a ′ · b ′ T 1 - c ′ · d ′ T 1 - c · d T ( 6 )
[0065] Where:
[0066] p 0 ′ is the predicted vapor pressure for the second compound
[0067] a′ is a constant relating to the second compound
[0068] b′ is a constant relating to the second compound
[0069] c′ is a constant relating to the second compound
[0070] d′ is a constant relating to the second compound
[0071] Equation 6 may be reduced to the final form:
p 0 p 0 ′ = a · b T - c · d T 1 - f · g T ( 7 )
[0072] Where:
[0073] a is a constant
[0074] b is a constant
[0075] c is a constant
[0076] d is a constant
[0077] f is a constant
[0078] g is a constant
[0079] Because compound concentration and hence chromatographic peak area is proportional to the vapor pressure, Equation 7 also applies to the peak area ratio, as described more fully below.
[0080] [0080]FIG. 3 shows chromatograms of the n-dodecane and naphthalene test mix thermostatted over a range of temperatures. The experimental conditions are given in Table 1. FIG. 4 shows a plot of area ratio (naphthalene/n-dodecane to give a positive slope) versus set temperature in ° C. The non-smoothness in the plot may be caused by errors in the measurement or may be a true indication of varying vial temperature (readings were taken with different vials, in different carousel positions and at different times).
TABLE 1 Experimental Conditions Chromatograph AutoSystem XL (PerkinElmer Instruments) Column 30 m × 0.32 mm × 1.0 μm PE-5 (PerkinElmer Instruments) Oven 200° C. Isothermal Carrier Gas Helium at 12.5 psig with PPC Interface Split injector at 250° C. with low dead volume liner Detector FID at 300 ° C., range x1, attenuation x4 Headspace HS40 XL (PerkinElmer Instruments) Thermostat Temp. 44° C. to 72° C. in 4° increments Thermostat Time 20 min. Pressure 15 psig with PPC Press Time 1 min. Inject Time 0.02 min. Withdrawal Time 0.5 min. Sample 180 mg naphthalene and 20 mg n-dodecane in 22-ml vial
[0081] By inverting the area ratios, the data seems to approximate to the following simple linear relationship, which is also plotted in FIG. 5:
Area Dodecane Area Naphthalene = 2.094 - 0.02313 · T ( 8 )
[0082] Thus, solving Equation 8 for T, the temperature of the vial can be determined by employing a chromatograph to measure the peak areas for n-dodecane and naphthalene.
[0083] The present invention, therefore, provides a method of measuring the effective temperature inside a sealed container which accurately reflects the true container temperature at all instrument settings, which takes into account temperature variations across various container positions, which measures the temperature of each container separately from other containers when a plurality of containers are used, which takes into account the fact that the container temperature may change over time, which allows for temperature calibration, which can be used to evaluate the temperature control performance of an instrument, which is easy to perform, which does not interrupt the normal operation of the instrument, which does not require special tools, and which uses chromatography to determine temperature.
[0084] Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many other modifications and variations will be ascertainable to those of skill in the art. | A method of measuring the effective temperature inside a sealed container having a headspace is provided. A liquid solvent is added to the container, and a solid compound is added to the liquid solvent to create a saturated solution. Vapor of the saturated solution is allowed to equilibrate in the headspace of the sealed container, and a volume thereof is transferred to a chromatographic column, where chromatographic readings of the equilibrated vapor are taken. A temperature within the sealed container is then calculated based upon the chromatographic readings of the equilibrated vapor, wherein the temperature calculation is based upon the concentrations of the liquid solvent and the solid compound in the equilibrated vapor. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to a large-sized transportable projection screen, having a fillable, shape-variable hollow body in the form of a structure made of fillable tubes.
A large-sized projection screen is known from US 2004/0211100 A1. WO 02/47057 A1 describes another apparatus with a three-dimensional construction for displaying visible images, with an inflatable body and a base. The body is formed by tube-like parts which, in the inflated state, have a predetermined shape in order to provide at least one display surface for displaying the visible images. U.S. Pat. No. 6,008,938 describes another transportable projection screen which can be inflated with cold air and is clamped between two inflatable towers and an inflatable tube connecting the towers. The two-dimensional structure is held upright by holding lines and extension arms fastened to the towers and is fastened to the ground.
A further two-dimensional projection screen has, according to DE 3028258 A1, a flexible, concave projection surface and an inflatable frame, and therefore said frame can be placed under pressure for stiffening purposes and in order to keep the projection surface stretched, with the frame being designed in such a manner that it forms a stray-light shade. Planar, two-dimensional large-sized projection screens which have inflatable supports are also known.
A planar structure of a large-sized transportable projection screen is known from DE 100 34 912 A1 and DE 203 18 473 U1. In DE 100 34 912 A1, a frame is formed by bringing together the ends of elongated tubes which can be filled with gaseous media and are made of flexible materials. According to DE 203 18 473, a virtually flat, inflatable hollow surface is formed, said hollow surface being formed from a plurality of individual, fixedly interconnected, sequentially fillable hollow bodies which are arranged parallel to one another. This planar structure also requires ropes, straps or rods for anchoring the structure in a stabilizing manner on the ground.
A screen which can be inflated with cold air, is inflated in a manner similar to a balloon and which is also bounded by walls formed by pockets which can likewise be inflated is known from U.S. Pat. No. 4,802,734. In order to keep the balloon-like structure in shape, the top and bottom surfaces within the balloon are pulled counter to each other by ropes. Only a curved realization of a projection surface is possible with the balloon-like structure. It also has an extremely high loss of air for the operation and, due to the pressurized interior filling, can only be walked on to a limited extent.
It would be desirable to improve both the stability and the picture quality of a large-sized projection screen.
This is the starting point of the invention, the object of which is to provide a large-sized transportable projection screen, the stability and picture quality of which are substantially improved.
SUMMARY OF THE INVENTION
The object is achieved by the invention wherein a large-sized projection screen comprises a three-dimensional internal space which is defined by the structure and is bounded on all sides, with the tubes being oriented in three directions in space, and with the internal space being bounded by at least one display surface which is arranged on an edge formed by one part of the tubes.
A tube is understood as meaning, according to the invention, any desired, fillable, shape-variable hollow body of elongate design. In this case, a tube can adopt both a bead-like shape determined to a greater or a lesser extent by the internal pressure and also—as also explained in detail—a defined, for example, cylindrical shape with any desired predetermined base area.
In other words, by means of the tubes which are oriented in three directions in space, the structure according to the invention forms a scaffolding-like or framework-like construct, by means of which the three-dimensional internal space is defined, i.e. there are open scaffolding or framework areas between the tubes.
The invention has recognized that, owing to the three-dimensional structure formed by the tubes, a hollow body is formed which, owing to its three-dimensional configuration, has intrinsic stability—as compared with the large-sized transportable projection screens which are mentioned at the beginning and are essentially realized only in two-dimensional form, the intrinsic stability as a rule not having to be ensured by additional ropes, frames or supporting structures. In other words, the invention has recognized that, with the large-sized transportable projection screen formed according to the above concept, a fillable, shape-variable hollow body is provided which can be filled within a very short period of time—for example within 10 to 30 min., and, in the process, develops intrinsic stability. The anchoring measures which are especially time-consuming and expensive are avoided with the large-sized transportable projection screen according to the above-described concept. Furthermore, operations at a height of customarily some meters are also avoided with the large-sized transportable screen according to the present concept. In general terms, it virtually involves a “turn-key system”, in which the large-sized transportable projection screen is provided by the filling of the shape-variable hollow body without further measures.
Furthermore, the large-sized transportable projection screen according to the present concept has considerably improved picture quality over the customary large-sized projection screens which are of planar and two-dimensional design. This is achieved above all by the fact that, in addition to the possibility of projection in dark surroundings, the possibility of projection in daylight conditions is also provided. The invention has recognized in this case that, in order to improve the image quality, a projector in the internal space of the structure can be arranged for rear-side projection onto the display surface, with the internal space expediently being bounded on all sides in order to form a space which is darkened against light incidence from the outside, preferably in order to form a dark chamber. In other words, the intermediate spaces formed by the scaffolding or framework of the tubes are advantageously bounded on all sides by light-proof darkening surfaces. That is to say, the internal space is preferably bounded by further darkening surfaces which are arranged on further edges formed by a further part of the tubes. The internal space of the structure is thereby darkened, which permits considerably improved rear projections onto the display surface even during daylight. In contrast thereto, the two-dimensional large-sized projection screens mentioned at the beginning are suitable only for projections in dark surroundings, since they do not have a darkened space for the arrangement of the projector. One darkening surface is preferably formed by a display surface.
According to the present invention, a display surface is understood as meaning, in particular, a projection surface. In this case, the projection surface is formed in the form of a rear projection surface, i.e. a projection surface which is impinged upon from the rear side—for example by a projector arranged in the structure—by an image which can be viewed from the front side—i.e., for example, by an audience looking at the large-sized transportable projection screen from the outside. In this case, it also lies within the scope of the concept of the present invention to use the display surface as a surface for displaying images which are not projected—either from the front side or rear side. Images of this type may be provided on the display surface, for example in the form of advertising images.
Consequently, it also lies within the scope of the concept of the present invention, to arrange not only one display surface but rather a multiplicity of display surfaces on an edge or edges formed by a further part of the tubes, which display surfaces can serve in each case either for the projection of moving or non-moving images or as a large display surface for non-projected images. For example, a structure also lies within the scope of the concept of the invention, in which only a single display surface is used as the projection surface and the further display surfaces—for example at the sides and on the roof—are used as advertising surfaces. The concept also includes a structure in which all of the available display surfaces or at least all of the lateral display surfaces are used as projection surfaces. For this purpose, a corresponding number of projectors or a projector guided in an appropriately movable manner in order to impinge in an alternating manner on the display surfaces can be arranged within the internal space.
According to the invention, the internal space forms a space which is darkened against light incidence from the outside. The all-sided boundary expediently has light-proof surfaces. The latter are preferably formed in the form of a display surface. In this case, it has proven particularly advantageous to design one surface to be dark on the inside and to be bright on the outside. This also counteracts a heating up of the internal space.
As already mentioned, it is advantageous, in particular for the provision of a large-sized transportable projection screen for daylight conditions, that the internal space is bounded on all sides in order to form a dark chamber. The boundary may be formed by non-inflatable darkening surfaces which, depending on requirements, can likewise be used as display surfaces—either as a projection surface or as a simple printed display surface. Less advantageous, but nevertheless conceivable, is also the possibility of arranging between the tubes planar, fillable, in particular inflatable elements which are fastened releaseably or non-releaseably. This would have the advantage, however, that the dark chamber formed by the structure can be entirely provided by the fact that the tubes and the planar elements are filled, preferably inflated. Further removal or covering of the open surfaces of the structure is therefore unnecessary. Irrespective of the manner in which the dark chamber structure is realized, the fillable tubes of the structure constitute a three-dimensional scaffolding or framework which imparts inner stability and intrinsic stability to the large-sized projection screen.
In accordance with the invention, it is provided to arrange the display surface which is arranged on an edge formed by one part of the tubes on a side of the tubes which faces the internal space. In other words, in this embodiment, the display surface is set back from the outside to the inside, toward the internal space. As a result, owing to the tubes which are, as a rule, of large-sized design, a shadow space is formed in front of the display surface. In this development, use is advantageously made of the fact that the tubes are already of a size sufficient for forming light protection. In the case of a tubular frame structure around the display surface, a shadow space which bounds the display surface on all sides is therefore provided, the shadow space limiting the light incidence from the outside in a particularly preferred manner. It has been shown that this brings about a very considerable improvement in the light conditions in the region in front of a display surface, in particular in the region in front of a projection surface. Even in the case of weak-light projectors, a projection in daylight conditions can nevertheless be realized with the large-sized projection screen according to this development. As an alternative, cost-effective projectors, such as, for example, a beamer, can be used.
In order to improve the shadow space, it is provided in particular to provide a tube which forms the edge with a diameter which corresponds at least to one third of the height of the display surface.
Advantageous developments of the invention are to be found in the subclaims and in particular provide advantageous possibilities for realizing the above-explained concept of the invention within the scope of the objective and also with regard to further advantages.
A filling medium is preferably air, in particular, cold air. Heated air or hot air may also be advantageous in winter. Further filling media, such as water or gas (for example N 2 or N e ) are likewise possible.
A preferred development of the invention makes provision for the tubes to be formed from a flexible two-wall material, between the two walls of which connections which define a predetermined distance between the walls of the two-wall material are arranged. A two-wall material of the above-mentioned type can be found in the international application which has not yet been published and was filed under the official designation PCT/EP2004/009040 on Aug. 12, 2004, the disclosure of which, in particular in respect of the design of the two-wall material, is herein incorporated into the disclosure of this application by this citation. A two-wall material of this type is formed in the form of a non-woven fabric, between the two walls of which there are connections. These connections may be, in particular, threads which are woven into the woven structure of the two-wall material and which, by means of their length, define a maximum distance between the walls of the two-wall material. A cavity is formed around the connections between the walls, which cavity can be filled in principle with any desired fluid, in particular with air as medium, in order to stiffen the material and, in the process, is closed in an air-proof manner. The two-wall material is shown in particular in FIGS. 1 , 2 and 3 , of the publication mentioned and is explained with reference thereto. The use of the abovementioned two-wall material for the tubes permits virtually any desired shape to be realized for the tubes. Without the use of the two-wall material, tubes can be of bead-like design—essentially defined by the size of their covering. Furthermore, when the two-wall material is used, a tube can be assigned a predetermined, defined shape, for example a cylindrical shape with a rectangular basic cross section or hexagonal basic cross section—depending on requirements.
The abovementioned two-wall material can also be used particularly advantageously for inflatable planar elements which, according to the abovementioned development, can be arranged on the tubes in a releasable or non-releasable manner in the intermediate spaces of the structure formed by the tubes.
The tubes, or planar elements, preferably communicate with one another via filling openings. In particular, the tubes, even in the case of an abovementioned development, can communicate with a planar, fillable—in particular inflatable—element via filling openings. As a result, the structure of the large-sized transportable projection screen can advantageously be filled by a single connection. In other words, fillable elements, in particular the tubes of the structure, are filled, in particular inflated, together and at the same time. However, this does not rule out separate structure elements or tubes which are joined or can be joined to one another being also able to be filled independently of one another, i.e., if appropriate, successively.
As already mentioned above, it has proven advantageous within the scope of a particularly preferred development for the structure to be free from planar, fillable partial hollow bodies. In other words, the hollow body in the form of the structure is composed entirely of the tubes. This guarantees the intrinsic stability of the hollow body, and a dark chamber can be realized in a particularly simple manner by removal of the intermediate spaces.
Furthermore, it has proven particularly advantageous within the scope of a development for a light shield and/or one or more panels to be arranged at the edge. This applies in particular to the edge on which a display surface used as the projection surface is arranged. According to this development, not only is light incidence from the back of the projection screen therefore limited—by the realization of a dark chamber, but also light incidence onto the projection surface from the front side is limited by the light shield. The light shield advantageously forms a shadow space in front of the display surface, in particular the projection surface. The capability of the large-size projection screen to operate in daylight conditions is thereby further improved.
A projector for rear projection onto the projection surface is preferably arranged in the internal space of the large-sized projection screen in a manner such that it can be adjusted variably in position. In particular, a projector is arranged in a height-adjustable manner, for example on a lifting platform. In particular, the light intensities of the projector on the rear side of the projection surface can thereby be matched to the light conditions prevailing outside the large-size projection screen.
Different embodiments have proven advantageous with regard to the design of the display surface. In the case of a projection surface, the latter is advantageously formed in the form of a semi-transparent screen. Depending on the surrounding light conditions, said screen may be designed to be a light milky color or else brownish beige. In the case of a display surface in the form of printing surfaces, for example in the form of mega-print screens, the display surface can be designed in a particularly advantageous manner as a tarpaulin. Such a tarpaulin may be holed or perforated. This has advantages in terms of weight.
For the attachment of a display surface, a tube which forms the edge preferably has an eyelet strip.
In order to permit entrance to the structure, it is advantageously provided that at least one point at the edge of a base area of the structure is free from tubes. In other words, a tube which edges the base area of the structure # 15 has an interruption or ends at an entrance opening. Such an entrance is provided in particular on the rear side, i.e. that side of the structure which lies opposite the projection surface.
For the structure, in principle very different spatial geometries can be realized in accordance with the concept of the invention. In particular with regard to the format, an image format which is customary for cinema presentations and in which the structure surrounds a cube-shaped internal space has proven particularly advantageous. Furthermore, three-dimensional shapes in the form of a cuboid, a sphere or spherical cap or a polyhedron are also possible. Cylindrical shapes with any desired base area can also be realized.
While the invention proves particularly useful for projection displays relevant to the use and is to be understood within this context and while the invention is also described in detail below with reference to examples which relate to the projection of moving images onto a large-sized projection screen, it should nevertheless be clear that the concept described here, as claimed, is likewise usable within the scope of other applications which lie outside the projection of movable images and concern uses which do not lie within the sphere of cinema or image transmission. For example, the concept presented could likewise be used for pure advertising purposes or in general in order to realize devices which require an intrinsic stability to be preferential. One example of this in the case of a cubic large-sized projection screen would be the use as a pure advertising cube. The concept could advantageously also be used, for example, to realize a simple display object or in order to realize platforms on which displays are to take place.
The large-sized projection screen can preferably have dimensions which are clearly more than two meters for length, width and height. Dimensions of around five to ten meters are particularly advantageous. A tube may have a diameter of significantly more than one meter.
Exemplary embodiments of the invention are described below with reference to the drawing in comparison to the prior art. The drawing is not intended to illustrate the exemplary embodiments to scale but rather is executed in a schematized and/or slightly distorted form wherever expedient for the purposes of explanation. For supplementary information about the teachings which can be directly discerned from the drawing, reference is made to the relevant prior art.
It should be taken into account here that various modifications and changes to the form and details of an embodiment can be made without departing from the general concept of the invention. The features of the invention which are disclosed in the description above, in the drawing and in the claims may be essential to the development of the invention either individually or in any desired combination. The general concept of the invention is not restricted to the precise form or the detail of the embodiments which are shown and described below or restricted to a subject matter which would be constricted compared to the subject matter claimed in the claims. For specified ranges of dimensions, values which lie within the aforesaid limits should also be disclosed as limiting values and be capable of being used and claimed as desired.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to explain the invention further, a preferred embodiment of the invention using the example of a large-sized projection screen with a projection surface for moving images is explained with reference to the figures of the drawing. In the drawing:
FIG. 1 shows a perspective view of a structure of a large-sized projection screen according to a particularly preferred embodiment of the invention as illustrated graphically in FIG. 6 to FIG. 11 ;
FIG. 2 shows a perspective rear view of the structure of the large-sized projection screen of FIG. 1 ;
FIG. 3 shows a perspective illustration of the large-sized projection screen with display surfaces inserted, with, according to a particularly preferred embodiment, the projection surface being set back and further display surfaces for accommodating advertising surfaces being removed and, as a result, a large-sized projection screen capable of projection in daylight conditions and with a dark chamber for accommodating the projector being formed;
FIG. 4 shows a perspective frontal view of the large-sized projection screen of FIG. 1 ;
FIG. 5 shows a front view of a large-sized projection screen of FIG. 3 according to a particularly preferred embodiment of the invention;
FIG. 6 shows a side view of the large-sized projection screen of FIG. 3 ;
FIG. 7 shows a plan view of a large-sized projection screen of FIG. 3 ;
FIG. 8 shows a rear view of a large-sized projection screen of FIG. 3 ;
FIG. 9 shows a sectional view of a large-sized projection screen of FIG. 5 along the line A-A;
FIG. 10 shows a sectional view of a large-sized projection screen of FIG. 6 along the line B-B;
FIG. 11 shows a sectional view of a large-sized projection screen of FIG. 8 along the line C-C.
DETAILED DESCRIPTION
FIG. 1 shows a hollow body 1 which is fillable, here with cold air, is inflatable and shape-variable and is in the form of a structure 1 made of fillable tubes 3 as part of a large-sized transportable projection screen. The tubes 3 serve here to define a three-dimensional internal space 5 , which is defined by the structure 1 and is surrounded here by it, and, for this purpose, are oriented in three directions in space x, y, z. As shown in FIG. 3 , the internal space 5 is bounded by at least one display surface 7 , in the present case in the form of a projection surface. In the present case, the projection surface 7 is arranged on an edge formed by one part of the tubes 3 A. In particular, in the embodiment described here, the internal space 6 is bounded on all sides by further display surfaces 8 , of which one can be seen in FIG. 3 , in order to form a dark chamber. In other words, the planar intermediate space 9 which is shown in FIG. 1 and is formed by the framing tubes 3 A is covered by the projection surface 7 shown in FIG. 3 , and the further planar intermediate spaces 6 shown in FIG. 1 , in the case of the scaffolding/framework of the structure 1 that is formed by the tubes 3 , are covered by further display surfaces 8 . The tubes 3 , 3 A therefore form a bordering structure 1 which defines the internal space 5 here on all sides and in this sense surrounds it while the lateral intermediate spaces between the scaffolding/framework of the tubes 3 , 3 A are covered by display surfaces—either in the form of a projection surface 7 or in the form of an advertising surface 8 . The large-sized transportable projection screen of the embodiment described here is thereby designed in the form of a large-dimensioned, three-dimensional structure similar to a cube in order to permit screen projections during mobile use in daylight conditions.
Use is made here of the technique of rear projection from a darkened space formed by the internal space 5 . As can be seen in FIG. 4 , a projector which is located in the dark internal space 5 and is described in more detail in FIGS. 5 to 11 is used in order to project an image 11 onto a special rear projection film which forms the projection screen 7 and on which an observer can see the image 11 from the outside with sufficient brightness and contrast even during daylight conditions. Without the internal space 5 designed as a dark space, such a projection during daylight conditions would be virtually impossible. This is the most serious disadvantage of the two-dimensional screens of the prior art explained at the beginning. Furthermore, the particularly preferred embodiment described here of the large-sized transportable projection screen ensures stability and mobility to a particularly improved extent owing to the structure 1 of an inflatable tubular frame, which structure is formed by tubes 3 , 3 A. The tubes have a comparatively large tube diameter in the range of 1.5 m. A special fan blower shown in FIGS. 5 to 11 ensures a simple and sufficiently stable construction of the structure 1 which, as a result, has sufficient intrinsic stability even during adverse weather conditions.
The main characteristic of the large-sized projection screen, which is illustrated perspectively in FIG. 3 and FIG. 4 , lies in the projection of transmissions. However, film and advertising presentations can likewise also be shown. Furthermore, the side surfaces and the back wall are designed for the attachment of advertising prints. For this purpose, the structure 1 has, inter alia, eyelet strips 14 , which are indicated in FIG. 1 and FIG. 2 , for the attachment, for example, of a projection surface 7 . Furthermore, it can be seen in the perspective rear view of FIG. 2 that at least one point 13 at the edge of a base area 4 of the structure 1 is free from tubes. In other words, a tube 3 B which borders the base area 4 of the structure 1 has an interruption 13 for the interruption of the tube-free point 13 . The point 13 serves as an opening in order to permit people to enter at the rear side, i.e. on the side 16 lying opposite the side 17 provided for the projection surface 7 .
Two different materials are chiefly used in order to produce the large-sized projection screen 10 .
In the case of the embodiment described here, all of the tubes 3 , 3 A, 3 B of the structure 1 are produced from a PCV-coated artificial fiber. Said fiber achieves sufficient stability at an internal pressure, which is to be set up in accordance with requirements, during the inflation of the tubes 3 , 3 A, 3 B. Furthermore, an artificial fiber of the type mentioned has proven sufficiently durable since, during repeated dismantling and construction within the course of long-term use of the large-sized projection screen 10 , both durability and airtightness are ensured.
The planar intermediate spaces 6 , 9 indicated in FIG. 1 and the planar intermediate spaces 17 , 16 indicated in FIG. 2 are provided for darkening purposes. In the case of the embodiment illustrated here, a darkening film 8 which is illustrated in FIG. 3 and is fastened to an eyelet strip 14 , which is provided on the outside of the structure 1 , serves for this purpose. The darkening film 8 serves as a display surface and, in addition, is impermeable to daylight and is water-proof. That is to say, even when there is increased sunshine, the internal space is reliably darkened and protected against overheating.
The large-sized projection screen 10 has proven completely mobile and can be constructed and dismantled extremely flexibly. Construction and dismantling are particularly uncomplicated, since all of the elements important for a screen presentation are fastened to the inflatable tubes 3 , 3 A, 3 B. The selection of the location can be as desired, since even non-secured underlying surfaces, such as grassy areas, earth, sand and the like do not have an adverse effect on the stability. Despite the intrinsic stability of the large-sized projection screen 10 ensured by the structure 1 , nevertheless no damage is caused to the underlying surface. Furthermore, specialized staff do not necessarily have to be acquired for the construction, since a responsible introduction to the object is sufficient in terms of safety for the construction and dismantling and for the operation of the large-sized projection screen 10 . After the air is let out of the structure 1 and, in the collapsed state, the hollow body 1 is accommodated on a Europallet in order to be able to be transported to the next location.
Furthermore, the embodiment illustrated here has particular safety advantages. As already explained, solid components which could cause damage in the event of a current failure are not used. Even if people are located in the internal space 5 of the structure 1 as the air is being let out, there is no risk to the people during the lowering operation because of the low weight of the woven fabric forming the structure 1 . The intrinsic stability and the reliability of the intrinsic stability are ensured above all by the provision of ballast in the lower edge region of the internal space. The intrinsic stability can be further increased, for example, also by means of weight barrels 15 , which are illustrated in more detail in FIG. 7 . Dimensions in the range of a diameter of 0.7 m and a height of 1.2 m are suitable for the realization of a weight barrel 15 of this type. Weight barrels filled with water increase the intrinsic stability of the structure 1 even further against sliding and tilting, for example should strong winds or squalls occur. In the event that, in the case of bad weather and severe storms or hurricanes, essential locking of the large-sized projection screen 10 or of the structure 1 to the ground has to be ensured, there is the possibility, as also in the case of known concepts, to fasten the structure 1 to the ground by means of ropes. In this case, both weights and earth anchors may be used. These additional safety measures are not illustrated in FIGS. 1 to 11 , since they are not necessary for the intrinsic stability of the structure 1 or of the large-sized projection screen 10 under normal ambient conditions.
The particularly preferred embodiment of the large-sized projection screen 10 shown in FIG. 1 to FIG. 4 has a tube diameter of 1.5 m and an overall weight in the constructed state of approximately 500 kg. It operates with display surfaces which have a white color to the outside and a dark color, for example black, to the inside. In particular, a darkening film made of coated PVC material is used as the darkening film. This is preferably a PVC film which is hardly inflammable and at most scorches even at high flame temperatures. The locking barrels 15 used to increase the intrinsic stability have a water-holding capacity of 350 liters.
In the case of the particularly preferred embodiment 10, described here, of a large-sized projection screen, a further convincing measure for realizing weakened light conditions even during projection in daylight conditions is the realization of a shadow space 19 , which can clearly be seen in FIG. 3 and FIG. 4 , in the region in front of the projection surface 7 . It is provided in this case that the display surface 7 , which is arranged on an edge formed by one part of the tubes 3 A, is arranged on a side which faces the internal space 5 —i.e. the inner side 2 of the tubes 3 A. As can clearly be seen in FIG. 3 , the display surface 7 which is designed as a projection surface is set back from the outside to the inside in order to form the shadow space 19 in front of the display surface 7 . In this case, the bead-like tubes 3 A which form the frame form a light protection which limits a potential light incidence on the display surface 7 from the front. As can likewise be seen in FIG. 3 and FIG. 4 , the tubes 3 A here have a diameter which corresponds approximately to half of the height of the display surface 7 . A sufficient light-shielding effect is thereby realized by the tubes 3 A. Nevertheless, in a development of the embodiment explained here, a light shield can additionally be arranged on the tubes 3 A. The latter can be extended or anchored, for example, in the form of a canvas blind or an upper and/or lateral panel, if appropriate a plurality of upper and/or lateral panels or the like. At least one panel arranged below the display surface 7 may also prove expedient sometimes.
In FIG. 5 to FIG. 11 , the preferred embodiment of a large-sized projection screen 10 that is explained in FIG. 1 to FIG. 4 is illustrated as a technical drawing in corresponding sides and sectional views. A size, which is suitable in particular for a cinema and television format, for the large-sized projection screen 10 is indicated here by way of example in the form of meters as the dimensions.
FIG. 5 shows a front view of the large-sized projection screen 10 with the structure 1 , in which, in the front view present, the tubes 3 A which form the frame for the projection screen 7 can be seen. The projection surface 7 is fastened to the structure 1 and to the tubes 3 A by clamping connections 21 and corresponding eyelet strips 14 and by a further eyelet strip 24 on the projection surface 7 . The projection surface itself has a size of 4.8 m×2.7 m. Other dimensions can likewise be realized that are preferably of between two and five meters in length or width.
The side view illustrated in FIG. 6 shows tubes 3 and 3 A of the structure. The display surface which is realized in the form of a darkening of the side wall is designed as an alternative to the display surface 8 of FIG. 3 . The side wall 8 A illustrated in FIG. 6 is fastened to the outside of the structure 1 via an eyelet strip connection 26 . It has a size in the present case of 7.3 m×5.2 m. FIG. 6 furthermore shows, as concealed elements of the internal space 5 , the display surface 7 , which is designed as the projection surface, on the inside 2 of the tubes 3 A. Furthermore, the projector 27 which is arranged in the internal space 5 and is arranged on a height-adjustable lifting platform 29 is shown. Via the height positioning of the projector 27 by means of the lifting platform 29 , the light conditions on the rear side of the projection wall 7 can be set in such a manner that they are appropriate for the light conditions of the surroundings in the external region 31 of the large-sized projection screen 10 .
FIG. 7 shows the plan view of the large-sized projection screen 10 with the fastening barrels 15 which serve to ensure the intrinsic stability. A display surface 8 B which forms the roof serves in addition for darkening purposes and, in a similar manner as in FIG. 6 , is fastened to the tubes 3 and 3 A of the structure 1 via an eyelet connection 26 . In the present case, the display surface 8 B has a size of 7.3 m×7.3 m. All of the other reference numbers are selected as in FIG. 6 .
In the rear view, illustrated in FIG. 8 , of the large-sized projection screen 10 , the elements which have already been explained are each provided with the same reference numbers as in the previous figures. In a modification of the structure 1 illustrated in FIG. 2 , the provision of an interrupted tube 3 B—in other words the provision of tube connecting pieces—on the rear side has been left out. On the contrary, the rear-side frame, which is formed by the tubes 3 , of the structure 1 is formed as a downwardly open, U-shaped profile which is covered by a display surface 8 C for the purpose of darkening the internal space 5 . Said profile is fastened, in a similar manner as the display surfaces 8 A, 8 B in FIG. 6 and FIG. 7 , to the outside of the tube 3 of the construction 1 by an eyelet connection 26 . The display surface 8 C which is designed as the back wall has a size of 7.3 m×6 m here.
The sectional drawing illustrated in FIG. 9 shows a view along the line A-A in FIG. 5 . In addition to the parts which are provided with the same reference numbers as in the previous drawings, a drainage 33 which is to be designed in accordance with requirements is furthermore provided in FIG. 9 on the display surface 8 B in order to form a water drain on the roof. Furthermore, a shadow frame 37 which surrounds the rear projection surface 7 is illustrated in FIG. 9 . The shadow frame 37 has a width of approximately 1.5 m. The shadow projection of the shadow space formed by the tubes 3 A of the structure 1 goes beyond said shadow frame in order to protect the display surface 7 against light incidence and thereby, in particular, to improve the capability of the large-sized projection screen 10 to project in daylight conditions.
FIG. 10 shows a sectional view of the large-sized projection screen 10 along the line B-B in FIG. 6 . In this case, the reference numbers used in the previous drawings have been used again for the same elements.
FIG. 11 shows a sectional view of the large-sized projection screen 10 along the line C-C in FIG. 8 . Again, the reference numbers which have already been used previously have been used for the same elements.
In order to provide a large-sized transportable projection screen 10 with improved stability and at the same time to realize the possibility of improved projection in daylight conditions, the invention starts from a large-sized transportable projection screen 10 , having a fillable, shape-variable hollow body in the form of a structure made of tubes 3 , 3 A, 3 B which can be crammed together. The invention makes provision here for a three-dimensional internal space 5 which is surrounded by the structure to be defined, with the tubes 3 , 3 A, 3 B being oriented in three directions in space and with the internal space being bounded by at least one display surface 7 which is arranged on an edge formed by one part of the tubes. | A large-sized transportable projection screen comprising an any-shaped fillable hollow body, which is embodied in the form of a structure consisting of fillable tubes. The aim is to develop a large-sized transportable projection screen exhibiting an increased stability and making it possible to obtain an improved projection at daylight. For this purpose, the structure defines a three-dimensional internal space limited on all sides thereof, wherein the tubes are oriented in three directions in space and the internal space is limited by at least one display surface arranged at the level of an edge formed by a part of tubes. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates generally to concrete shoring apparatus used in forming concrete structures and, more specifically, to a latch that can be utilized to rapidly and securely attach U-heads to concrete shore towers.
[0003] 2. Background of the Prior Art
[0004] Concrete forming apparatuses are in wide use in the construction of buildings, bridges, and other concrete structures. The formwork against which the concrete is formed is often held into place by shoring apparatus. In creating shoring apparatus having the desired configuration, it is beneficial to be able to interconnect various components of the shoring apparatus in a wide variety of adjusted positions and to be able to quickly and easily connect, disconnect, and adjust the positions of the components. Further, it is advantageous to have the ability to interconnect the various components of the shoring apparatus in a wide variety of configurations without unduly multiplying the number of distinct components that are required to assemble the shoring apparatus of desired diversity.
[0005] Concrete shoring suppliers deliver truckloads of shoring equipment to a customer's job site, to facilitate shipping purposes, the equipment is dissembled. When the shoring equipment arrives at the customer's job site, the customer is then required to assemble the shoring towers prior to use. Thus, to save time and money, it is desirable to have rapid attachment methods during the assembly of the towers.
[0006] Previously, a U-head has been attached to shoring posts using a pipe welded to the base of the U-head. This pipe has a drilled hole that permits a pin to secure the head through the shore post. Another method utilized uses a pipe that has a spring pin that secures the U-head to the shore post. These previous methods utilize many loose pieces that must be attached, are easy to lose, and are time consuming to assemble. Accordingly a need exists for the rapid attachment and release of the U-head to the concrete shoring tower.
SUMMARY OF THE INVENTION
[0007] An object of the invention comprises providing a device for attaching the U-head to a concrete shoring tower, where the device provides for rapid and secure attachment.
[0008] These and other objects of the present invention will become apparent to those skilled in the art upon reference to the following specification, drawings, and claims.
[0009] The present invention intends to overcome the difficulties encountered heretofore. To that end, a U-head plate is provided having a channel for capturing a base plate of a shoring apparatus. A latch is attached to the U-head plate and has a tongue for engaging a notch in the base plate of the shoring apparatus, upon capture of the base plate of the shoring apparatus within the channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a perspective view of a U-head assembly and a shoring apparatus.
[0011] [0011]FIG. 2 a is a side view of a shoring post.
[0012] [0012]FIG. 2 b is a cross-sectional end view of the shoring post of FIG. 2 a , taken along the line A-A in FIG. 2 a.
[0013] [0013]FIG. 3 is an end view of a base plate of the shoring apparatus.
[0014] [0014]FIG. 4 a is a side view of the U-head assembly.
[0015] [0015]FIG. 4 b is a bottom view of the U-head assembly.
[0016] [0016]FIG. 4 c is a cross-sectional view of the U-head assembly, taken along the line A-A in FIG. 4 b.
[0017] [0017]FIG. 5 a is a side view of a U-head channel plate.
[0018] [0018]FIG. 5 b is a bottom view of the U-head channel plate.
[0019] [0019]FIG. 5 c is a cross-sectional view of the U-head channel plate, taken along the line A-A in FIG. 5 b.
[0020] [0020]FIG. 6 is an end view of the U-head channel plate.
[0021] [0021]FIG. 7 a is bottom view of a latch of the U-head assembly.
[0022] [0022]FIG. 7 b is a side view of the latch of the U-head assembly.
[0023] [0023]FIG. 7 c is a top view of the latch of the U-head assembly.
[0024] [0024]FIG. 7 d is a cross-sectional view of the latch of the U-head assembly taken along the line A-A shown in FIG. 7 b.
[0025] [0025]FIG. 7 e is a cross-sectional view of the latch of the U-head assembly taken along the line B-B shown in FIG. 7 b.
[0026] [0026]FIG. 7 f is a cross-sectional view of the latch of the U-head assembly taken along the line C-C shown in FIG. 7 b.
[0027] [0027]FIG. 7 g is a cross-sectional view of the latch of the U-head assembly taken the line D-D shown in FIG. 7 b.
DETAILED DESCRIPTION OF THE INVENTION
[0028] In the Figures, FIG. 1 shows a U-head assembly 10 attached to a concrete shoring apparatus 12 . The U-head assembly 10 comprises a U-head channel plate 14 . The U-head channel plate 14 includes two opposing channel walls 16 , 18 , a channel base 20 therebetween, and two inwardly opposing L-shaped extensions 22 , 24 extending downward from opposite sides of the channel base 20 . Holes 26 in the channel base 20 provide for securing beams (not shown) within the U-head assembly 10 . A latch 28 is attached to one of the L-shaped extensions 22 . Those of ordinary skill in the art will understand that the latch 28 can attach to either extension 22 , 24 . The U-head plate 14 of the U-head assembly 10 is attached to the shoring apparatus 12 by capturing a base plate 30 of the shoring apparatus 12 within a channel created by the opposing L-shaped extensions 22 , 24 . The base plate 30 also contains notches 32 , centered on each side of the base plate 30 . The shoring apparatus 12 also comprises an adjustable jackscrew 34 that is then attached to another identical notched base plate 30 of a shoring post 36 . Of course, the U-head assembly 10 can attach to either base plate 30 of the shoring apparatus 12 .
[0029] For further detail of the shoring apparatus 10 , FIG. 2 a shows a side view of the aluminum shoring post 36 , with base plates 30 located on each end. FIG. 2 b illustrates the cross-sectional end view of the shoring post 36 , taken along the line A-A in FIG. 2 a , detailing the base plate 30 , showing the notches 32 centered on each side of the base plate 30 .
[0030] The latch 28 of the U-head assembly 10 attaches to the L-shaped extension 24 . Shown best in FIGS. 4 a - c , the base 20 of the U-head channel plate 14 includes a hole 38 (see also FIGS. 5 a - c ). The hole 38 aligns with a hole 42 in an ear 40 of the latch 28 . A nut and bolt combination 44 releaseably secures the latch 28 to the base 20 , through the holes 38 , 42 in the U-head plate 14 and latch 28 . The bolt head of the nut and bolt combination 44 is recessed so as to not interfere with the movement of beams in and out of the U-head assembly 10 . The L-shaped extension 22 includes a hole 46 aligned with a tongue 48 of the latch 28 such that the tongue 48 extends into, and through, the hole 46 . On the end of the latch 28 opposite to the tongue 48 is a spring post 50 and spring 52 captured on the spring post 50 .
[0031] The movement of the latch 28 , best illustrated in reference to FIGS. 7 a - c and 4 a - c , allows the tongue 48 to engage the notch 32 of the base plate 30 under the biasing force of the spring 52 . The spring 52 biases the latch 28 such that the tongue 48 of the latch is forced inward through the hole 46 in the L-shaped extension 22 . Engaging the U-head assembly 10 with the shoring apparatus 12 is accomplished by slideably moving the U-head assembly 10 onto the base plate 30 such that the channel created by the inwardly opposing L-shaped extensions 22 , 24 captures the edges of the base plate 30 . The tongue 48 rides along the outside edge of the base plate 30 until the hole 46 in the L-shaped extension 24 approaches the notch 32 in the base plate 30 . At this point the spring 52 biases the tongue 48 into the notch 32 thereby engaging the U-head assembly 10 and the shoring apparatus 12 . The hole 46 is positioned at the midpoint of the L-shaped extension 24 in order to best balance the U-head assembly 10 on the shoring apparatus 12 .
[0032] To disengage the U-head assembly 10 merely requires compressing the spring 52 until the tongue 48 disengages from the notch 32 of the base plate 30 . The latch 28 pivots about the hole 42 in the ear 40 . In other words, pressure applied to the outside of the latch 28 at the end adjacent to the spring 52 will disengage the tongue 48 of the latch 28 , thereby allowing for slideably removing the U-head assembly 10 from the base plate 30 of the shoring apparatus 12 .
[0033] In the preferred embodiment of the invention, the shoring post 36 shown in FIG. 2 a is measured at a length of 11′-5½″, with a weight of 41.94 lbs., and is constructed of aluminum. The base plate 30 measures approximately 6″ along each side, taking into consideration the rounded edges, and is ⅜″ thick. The base plate 30 is affixed to the shoring post 36 with four 1 {fraction (3/16)}″ welds equally spaced around the outside of the center diameter of the shoring post 36 . The base plate 30 is also constructed of aluminum. The base plate 30 , best shown in FIG. 3, includes holes 54 to allow for interconnection of the components of the shoring apparatus 12 . The notches 32 in the base plate 30 are centered on each side of the base plate 26 and have an inside width of 1{fraction (1/16)}″.
[0034] The compression spring 52 is measured at a free length of 0.875″, with an outside diameter of 0.480″ and an inside diameter of 0.354″. The spring rate is 65 lbs/inch, with closed and ground ends. The bolt and nut combination 44 is composed of a ¼-20 steel center lock nut with a lock nut with rectangular indentation. The screw for this combination is a ¼-20×⅞″ hexagon socket flat countersunk head cap screw.
[0035] The U-head channel plate 14 is extruded aluminum and measures 8⅛″×2⅜″×14″. The outside of the L-shaped extensions 22 , 24 are located on the base 20 of the U-head channel plate 14 inset at a distance of 0.750″ from the outside rounded corners. The L-shaped extensions 22 , 24 extend down from the U-head channel plate 14 a distance of 0.438″+/−0.014″ and corner in at the bottom a length of 1″. The length from the outside sharp corner of L-shaped extension 16 to the outside sharp corner L-shaped extension 18 is 6.625″. The inside distance from the end of L-shaped extension 16 to L-shaped extension 18 is 5.125″+/−0.044″.
[0036] The latch 28 has a length of 5{fraction (3/16)}″. The tongue 48 is ⅞″ wide at a height of 1⅜″ from the base of the latch 28 . The compression spring 42 is positioned at a distance of 1″ from the center of the bolt and nut combination 44 . At this length, the latch 28 has a height of ½″, which then increases to {fraction (9/16)}″ at the center of the bolt and nut combination 44 . The height of the lever latch 28 stays at ½″ until it increases to ¾″ at a distance of approximately 2{fraction (5/16)}″ from the inside edge of the bolt and nut combination 44 , then it is at a height of ¾″ for a distance of ¼″, when it then raises to the top height of 1⅜″, where it is notched for ⅞″ before returning to the height of ¾″ until the end of the latch 28 .
[0037] The U-head assembly 10 allows for quick and easy assembly. It utilizes a minimum of moving parts, and eliminates the need for any lose parts. The assembly 10 allows does not require any special tools to attach or remove the assembly 10 from the shoring apparatus 12 . The latch 28 is easy to operate due to the fact that it self engages with the notch 32 of the base plate 30 , and disengages with a reasonable amount of pressure. In this manner, the assembly substantially reduces, or eliminates the problems associated with prior art assemblies.
[0038] The foregoing description and drawings comprise an illustrative embodiment of the present invention. The foregoing embodiments and the methods described herein may vary based on the ability, experience, and preference of those skilled in the art. Merely listing the steps of the method in a certain order does not constitute any limitation on the order of the steps of the method. The foregoing description and drawings merely explain and illustrate the invention, and the invention is not limited thereto, except insofar as the claims are so limited. It is anticipated that those of ordinary skill in the art with this disclosure before them will be able to make modifications in variations therein without departing from the scope of the invention. | A U-head plate is provided having a channel for capturing a base plate of a shoring apparatus. A pair of inwardly opposing L-shaped extensions extending downwardly from the U-head plate forms the channel. A latch attached to the U-head plate has a tongue for engaging a notch in the base plate of the shoring apparatus upon capture of the base plate of the shoring apparatus within the channel. The tongue is biased toward the notch by a spring. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates in general to the field of hot forming articles and especially to a method of and an apparatus for hot forming of at least a part of an article, and to articles which at least in part are hot formed.
2. Description of Related Art
In the field of hot forming of articles exists a huge experience, especially in the field of drawing of fiber optic articles, as single fibers, hollow fibers, multi fiber rods or of optical face plates, inverters, and tapers.
Optical fibers or multi fiber rods may consist of glass or synthetic material as plastic, especially polymeric material, or any combination of these materials.
Further, hot ductile material as glass ceramic material is heated to initiate micro crystallization or ceramization processes.
In shaping processes, especially hot forming or hot post-processing, semi-transparent or transparent glasses and/or glass ceramic materials and plastics are heated up to a processing point where a viscosity η between 10 14.5 and 10 4 dPas is encountered or beyond that. Semi-transparent or transparent glasses and/or glass ceramics, for the setting-in of certain material properties, for example ceramization, are heated mostly to temperatures which lie preferably above the lower cooling point at a viscosity η of about 10 14.5 dPas.
Typical, lower cooling points for glasses can be, depending on the type of glass, between 555 K and 1063 K, and typically the processing point can be up to 1978 K. For plastics the cooling and the processing point can be even much lower, typically being in the range of 250 K up to 580 K.
Hitherto according to the state of the art semi-transparent or transparent glasses and for glass ceramics, for example for ceramization, were heated preferably with surface heating by hot air and/or long-wave infrared is radiation. As surface heating there are designated processes in which at least 50% of the total heat output of the heat source is introduced into the surface or surface-near layers of the object to be heated.
Since most glasses in this wavelength range exhibit an absorption edge, 50% or more of the radiation output is absorbed by the surface or in surface-near layers.
As glass or glass ceramic material has as a rule a very low heat conductivity in the range 1 W/(mK), it was believed that glass or glass ceramic material with increasing thickness must be heated up more and more slowly in order to keep tensions in the glass or glass ceramics low. It was believed that when a homogeneous heating-up of the glass or of the glass ceramic is not achieved or is only inadequately successful, then this unfailingly would result in inhomogeneities in the process and/or in the product quality and/or in destroying the material.
From DE 42 02 944 C2 there has become known a process and a device comprising IR radiators for the rapid heating of materials which have a high absorption above 2500 nm. In order to rapidly introduce the heat given off from the IR radiators, into the material, DE 42 02 944 C2 proposes the use of a radiation converter from which secondary radiation is emitted with a wavelength range shifted into the long-wave direction with respect to the primary radiation.
A heating of transparent glass homogeneous in depth with use of short-wave IR radiators is described in U.S. Pat. No. 3,620,706. The process according to U.S. Pat. No. 3,620,706 is based on the principle that the absorption length of the radiation used in glass is very much greater than the dimensions of the glass object to be heated, so that the major part of the impinging radiation is transmitted through the glass and the absorbed energy per volume is nearly equal at every point of the glass body. What is disadvantageous in this process, however, is that no homogeneous irradiation over the surface of the glass objects is ensured, so that the intensity distribution of the IR radiation source is replicated on the glass to be heated. Moreover, in this process only a small part of the electric energy used is utilized for the heating of the glass.
In production processes of fiber optical image or light guides made of glass or plastic a preform which consists of multi-component transparent, semi-transparent and/or opaque glasses or plastics is heated by means of an electrical resistance heating and drawn to a fiber/multi fiber rod. If necessary, the developing fibers/fiber rods can be brought together again afterwards to build new preforms, which are again drawn to fibers/fiber rods. These new fibers/fiber rods thereby contain a multitude of the fibers/fiber rods drawn in the previous step. After several of such process steps one can get a fiber rod with several million single fibers, which can be used as image guides.
It proved to be difficult even for preforms with diameters greater than 50 mm to achieve a temperature distribution which is as homogenous as possible within the preform consisting of multi-component transparent, semi-transparent and/or opaque glasses or plastics, in a way that the drawing to a fiber/multi fiber rod does not lead to irregularities within the fibers/fiber rods. With plastics especially, the thermal damage at the surface has to be mentioned. Furthermore, the heating speed of the preform is crucial, since for drawing the fiber the preform can only be inputted and drawn as fast as mass is sufficiently heated.
A conventional resistance heating with temperatures of typically 1300 K at the heating coil is inadequate in this respect especially with preforms of diameters larger than 50 mm, since the emitted radiation is in a wavelength range absorbed on the surface or in layers near the surface of the glass or the plastic (penetration depth<1 mm), the heating thereby being a surface heating. The inner part of the preform has to be heated completely by thermal conduction. Since glass and plastic have a poor thermal conductivity, a lot of time is needed for the heating process especially of preforms with large dimensions, because it is necessary also for the inner part of the preform to reach the temperature needed for drawing and to reduce the average temperature within the preform. Also the subsequent drawing of the fiber or rod therefore can be done only with a limited speed, since new material of the preform has to be provided and heated continuously.
A possibility to avoid these difficulties should be, according to EP 1 171 392, to replace the heating elements usually used until now by appropriate short wave IR radiation sources arranged in a radiation cavity, the color temperature of which is above 1500 K and thus, a maximum radiation intensity at a wavelength shorter than 2000 nm. In this range, many glasses and plastics are almost transparent and absorb little of the incoming radiation. That way, a depth effective heating is achieved. Only negligible temperature inhomogenieties still arise, because every volume element absorbs the almost same amount of radiation. These amounts are each very small, since the absorption is very low.
By means of multiple reflections of the short-wave IR radiation at the walls of the radiation cavity the part of radiation reaching the material to be heated indirectly is above 50%. Furthermore, the associated rise in efficiency results in extremely high heating rates without damage to the material or disturbing temperature gradients.
However, in the production of image guides many, up to several million, single fibers/fiber rods are brought together to build a preform and often additionally single fibers of high-absorbing material are placed in between for contrast increase. The penetration depth from the side for short-wave IR radiation is drastically reduced by these high-absorbing fibers/fiber rods and by the Fresnel-reflection at the transparent fibers. That is because the radiation hitting from the side during the heating has to cross each single fiber/multi fiber rod, thereby passing two surfaces. Since there is a change in the refractive index at each surface crossing from glass or plastic to air or vice versa, according to Fresnel about 4% of the incoming radiation is reflected at each surface, which amounts to a total of 8% of the radiation per single fiber.
The reflected radiation hits surfaces of fibers crossed on the way to the inner region of the fiber again on the way back towards the periphery and is thereby again partly reflected, so that the effective penetration depth of the radiation into the inner region of the preform is up to 30 mm depending on the design. That means that in contradiction to the teachings of EP 1 171 392 neither is the preform completely penetrated by all of the IR radiation, so that an important amount of the radiation is reflected at the opposite wall of the radiation cavity, nor is only a small amount of the incoming radiation absorbed by the preform. Rather, an important amount of the total radiation is absorbed by the preform through multiple reflections and absorptions within the preform. A homogenous heating according to EP 1 171 392 especially of large preforms therefore is not possible.
It is an object of the invention, to improve the performance of hot forming processes.
BRIEF SUMMARY OF THE INVENTION
The invention depicts a method of hot forming of at least a part of an article, wherein said article comprises
a material selected from the group consisting of transparent and semitransparent materials,
wherein said at least a part of said article is heated by means of radiation and
said heated part of said article is formed and whereby
said heating is a semi-homogeneous heating.
The invention further teaches
an apparatus for forming at least a part of an article comprising
a holding means for holding said article
a heater means for heating said at least a part of the article
a forming means for forming of at least said part of the article,
whereby said means for heating comprises a radiation source for heating said at least part of the article, and whereby
said forming means is a drawing means.
The invention also covers articles formed according to an embodiment of the inventive method.
Preferably said semi-homogeneous heating causes a decrease of the draw temperature being both lower at a central portion of said article and at the surface of said article compared to conventional heating methods as for instance surface heating methods as discussed before.
According to the invention, semi-homogeneous heating is defined as heating at least one part or section of the article homogeneously or substantially homogeneously and at least one other part or section inhomogeneously with respect to the primary radiation source. Homogeneous heating may be, e.g., achieved by irradiating the part or section with radiation having a considerably larger penetration depth than the measure of the section in the direction of the incident radiation.
Inhomogeneous heating may result from a penetration depth of the heating radiation which is lower than the dimensions of the section to be heated.
Although inhomogeneous heating of a section of the article is applied, the temperature distribution according to semi-inhomogeneous heating is at least partly homogenized due to light guiding from a homogeneously heated region with nearly uniform radiation distribution inside the section to the inhomogeneously heated section.
Further, a transparent material is defined herein as a material which transmits more than 50% of the impinging radiation. A semi-transparent material is defined as a material which transmits more than 0% but less than 50% of the impinging radiation and an opaque material as a material that transmits 0% of the radiation.
Of course, the features of transparency, semi-transparency and opacity depend on the spectral distribution of the impinging radiation so that these features are always defined with respect to the spectrum of the radiation.
Although a more homogeneous distribution of the heating radiation is achieved by means of the invention, the temperature distribution may not be entirely uniform. Thus, according to one embodiment of the invention, the semi-inhomogeneous heating causes an increase of temperature of the heated article being lower at a more central portion and higher at a more peripheral portion of the article.
According to a development of this embodiment the more central portion is closer to the middle than the more peripheral portion. In example, the central portion may, e.g., be located in the middle and the peripheral portion at the periphery of the article.
In a preferred embodiment of the invention the material of at least said part of the article consists of glass.
In a further preferred embodiment of the invention, the material comprises an organic material selected from the group consisting of plastic, synthetic, and polymeric material.
In a still further preferred embodiment of the invention the material comprises glass and a material selected from the group consisting of plastic, synthetic, and polymeric material.
In a most preferred embodiment a radiation source is emitting electromagnetic radiation whereby more than 50% of the emitted radiation is in a wavelength range of 200 to 2700 nm and is a radiator having a temperature of more than 1500 K, especially having a temperature of about 3000 K.
A most preferred forming process according to the invention is a draw process.
The invention addresses a down-draw process and alternatively may be applied to an up-draw process.
Conventional heating methods used to draw articles comprising glass usually encounter the problem that peripheral portions of the article are heated up to considerably higher temperatures compared to more central portions. However, in order to draw the article, the more central portions need to be heated beyond the drawing temperature. In this case the higher temperature of the more peripheral portions may exceed a level at which undesirable changes of the material occurs. For example, the crystallization temperature may be exceeded. By employing semi-inhomogeneous heating according to the invention, however, the temperature difference between central and peripheral portions can be kept lower compared to conventional heating.
Accordingly, the invention provides a method of forming of at least a part of an article, preferably by employing a draw process, whereby the heated part of the article comprises glass and has a diameter of at least 50 mm, and whereby a temperature difference of 100 K at the most exists between a more central portion of the article and a more peripheral portion when the at least part of the article is heated.
According to another aspect of the invention, there is provided a method of forming of at least a part of an article, preferably by employing a draw process, whereby the heated part of the article comprises glass and has a diameter of at least 50 mm, and whereby even a temperature difference of only 40 K at the most exists between a more central portion of the article and a more peripheral portion when the at least part of the article is heated. Thus, with respect to articles comprising glass, semi-inhomogeneous heating may also be defined as heating of an article comprising glass and having a diameter of at least 50 mm, whereby a temperature difference of 100 K, or even of only 40 K at the most exists between a more central portion of the article and a more peripheral portion.
Generally, the temperature gradient within the heated material can be kept considerably lower compared to conventional heating methods. In particular, it has been established that by using semi-homogeneous heating the temperature gradient between a peripheral and a central portion of a heated part of the article comprising glass and having a diameter of more than 100 mm may lie below 1 Kelvin per millimeter, whereby the central portion has a temperature of more than 580 K.
Coming along with the low temperature differences inside of a heated article by utilizing inventive semi-inhomogeneous heating, a material can be drawn with reduced maximum temperature at peripheral portions, thereby avoiding undesirable effects such as liquefying and dropping-off of peripheral portions of the heated part.
The method is applicable within a large temperature range depending on the drawing material chosen. Thus, an article may be formed according to the invention with the more peripheral portion having a temperature of between 290 K and 2000 K.
In example, a material comprising a typical optical glass may be formed whereby a more peripheral portion of the article has a temperature of between 835 K and 915 K when the article is formed.
Another advantage of the invention is the comparably short heat-up time coming along with semi-inhomogeneous heating. Specifically, an article as defined above, comprising a more central portion and a more peripheral portion may be heated according to the invention so that the more peripheral portion of the heated part is heated in a period of time of less than six hours from a temperature of lower than 300 K to a temperature of higher than 890 K. Depending on the material to be heated and the dimensions of the preform, the more peripheral portion of the heated part may be heated from a temperature of lower than 300 K to a temperature of higher than 890 K in a shorter period of time, without generating tension cracks in the material. Specifically, the period may be less than 3 hours or even less than 1 hour.
Furthermore, it has been established that the inventive mechanism of semi-homogeneous heating works for many different cross-sectional shapes of a preform, such as for preforms having circular, elliptic, octagonal, hexagonal or quadratic cross-section.
Surprisingly, a rate of drawing may exceed a velocity of 10 mm per minute of the drawn part of the article relative to a clamped part of the article, the article being a multi fiber preform having a diameter of 115 mm and the drawn part having a diameter of about 25 mm or more. Generally, the processing of large preforms, which becomes possible using the invention also allows to fabricate multi fiber rods with larger diameters. Specifically, multi-fiber rods having diameters of greater than 25 mm, greater than 50 mm, or even greater than 79 mm may be drawn in a single drawing step.
Surprisingly also a multi fiber bundle having a diameter of more than 115 mm, of more than 125 mm and of more than 150 mm could be drawn to a diameter of up to 76 mm having optical grade quality.
The inventive method as well applies to forming a multi fiber rod out of a preform with a diameter greater than 25 mm, or greater than 50 mm or even greater than 75 mm with considerable drawing speed, whereby the preform may have large diameters of more than 100 mm, of more than 125 mm or even more than 150 mm.
According to still another aspect of the invention, an improved method of processing a multi fiber preform is provided, comprising the steps:
i) a multi fiber preform obtained by arranging a plurality of mono fibers is heated semi-homogeneously,
ii) the semi-homogeneously heated multi fiber preform is drawn,
iii) the drawn multi fiber preform is separated at predetermined length intervals, and
iv) a plurality of drawn multi fiber preforms being separated at the predetermined length intervals is arranged in parallel forming a multi fiber bundle having an increased number of fibers, whereby the multi fiber bundle having an increased number of fibers is processed according to process steps i), ii) and iii).
Due to the very efficient semi-homogeneous heating, the improved method enables considerably higher drawing speeds. Thus, the inventive method enables fast fabrication of multi fiber rods with a very large number of fibers.
During the drawing step, the plurality of drawn multi fiber rods may additionally be twisted. Alternatively, the plurality of drawn multi fiber rods may be twisted after the drawing step.
Preferred articles formed at least in part by a process according to the invention comprise a fiber or a multi fiber rod. As well, an article may be formed from a preform comprising a cladding tube surrounding at least in part a core of a multi fiber preform.
Further preferred embodiments of the invention comprise an optical face plate, an optical inverter, an optical twister, a taper, a hollow fiber or a photonic crystal fiber, or a combination of these components.
The invention is described in more detail below in the light of preferred and most preferred embodiments thereof.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Reference is made in the detailed description of the preferred embodiments of the invention to the appended drawings in which
FIG. 1 shows a cross sectional view in a vertical plane extending across the center of a heating unit for semi-homogeneously heating at least a part of a multi fiber preform;
FIG. 2 shows emission spectra of a radiator emitting at a temperature of 1500 K and of a radiator emitting at a temperature of 3000 K and absorption characteristics of Schott Glass' 8505 Glass;
FIG. 3 shows wavelength dependent re-emission, absorption and transmission characteristics of electromagnetic radiation directed to a multi fiber bundle having a thickness of about 2.6 mm;
FIG. 4 shows a cross sectional schematic view in a vertical plane extending across the center of a multi fiber bundle down draw apparatus;
FIG. 5 shows a cross sectional view in a vertical plane extending across the center of a multi fiber bundle up draw apparatus;
FIG. 6 shows temperature distributions along a cross sectional view extending perpendicular to the longest dimension of a square shaped multi fiber bundle preform before drawing and in the course of drawing the multi fiber bundle preform;
DETAILED DESCRIPTION OF THE INVENTION
Surprisingly, the invention succeeded in heating preforms of so far unknown diameters of more than 100 mm by means of a radiation unit utilizing short-wave radiation sources and walls, which have very good back scattering or reflecting properties, in a fast and semi-homogenous way and in drawing these afterwards with speeds of more than 10 mm/min and with a diameter of the drawn multi fiber rod of 25 mm whereby the preform features 115 mm in diameter.
The effect results from the instantaneous absorption of the radiation hitting the preform in a way that only a part of less than 50% of this radiation crosses the part of the preform, which is not tapered and may hit the preform again indirectly after reflection at the opposite wall of the radiation unit. The walls of the radiation unit are important for the homogenization of the radiation emitted by the radiation sources and reflected or scattered by the walls and for increasing the efficiency.
Furthermore, a part of the radiation emitted from the radiation sources, which hits the fibers under an angle below a certain value, is coupled into the single fibers/fiber rods and is axially transported, that way also contributing to the heating of the whole preform. This effect is especially noteworthy after starting the actual drawing of the fiber, since the radiation can penetrate up or down to the center of the preform in the part, which is tapered to a fiber/multi fiber rod, and the part of the radiation there being coupled into the fibers/fiber rods is axially transported also to the part of the preform, which is not tapered. Thereby, the inner fibers/fiber rods of this part of the preform, which are not directly reached from outside because of the limited penetration depth of the radiation, are indirectly heated.
Furthermore, as mentioned above, the tapered part of the preform can be penetrated by the radiation almost completely leading to an almost homogeneous temperature distribution and homogeneous heating. Therefore, beginning from this area less tapered parts of the preform which may be heated inhomogeneously by the primary radiation sources can be heated homogeneously or nearly homogeneously by conducting the heat and/or guiding the radiation, too.
Solid state emitters such as halogen tungsten emitters, but also gas discharge or electric-arc emitters can be utilized as radiation sources, wherein more than 50% of the complete radiation power of each emitter shall be within the wavelength range between 200 nm and 2700 nm.
The possibility to combine several process steps is one of the advantages of using large preforms besides economical aspects. Furthermore, the size of radiation units according to the invention can be minimized compared to conventional furnaces, which leads to reduced losses of the preform when starting up and shutting down the facility.
Subsequently, the invention is described with regard to the figures and by means of the preferred embodiments:
With the facility 1 shown schematically in FIG. 1 various fiber drawing experiments have been performed. In the experiments glass and plastic preforms have been used. Generally, all drawable transparent or semitransparent glasses or partly opaque glasses or combinations of these or plastics can be utilized. As well, preforms comprising glass ceramics can be drawn by employing the inventive method of semi-homogeneous radiation heating.
The diameter of the preforms was between 5 mm and 115 mm, wherein these are only exemplary values with no limiting meaning in upward or downward direction.
The preforms can either comprise only one glass or plastic in any conceivable geometry, like for instance round, square, triangular or polygonal rods and/or tubes or the like, or they can comprise several glasses or plastics, like for instance tubes of glass type 1/plastic type 1, in and/or around which rods of glass type 2/plastic type 2 are positioned. The preforms can also consist of several different single fibers/multi fiber rods put together, which can also be positioned inside a round or polyhedral tube.
The prototype facility can continuously produce fiber rods or fibers depending on the length and the diameter of the preform. This is carried out according to the following principle:
1. Pre-Heating
The pre-heating process has to be carried out once each time the facility is started up to prevent breaking of the preform 3 due to thermal tensions between the part 31 inside and the part 32 outside of the furnace 5 . For this purpose the preform is transported into the radiation unit 7 . The preform 3 is heated by means of a ramp temperature or power controlled. This only concerns that part of the preform 3 within the radiation unit, the part outside is not heated and has a temperature at the clamping point, which is slightly above room temperature depending if this part of the preform is insulated or not.
2. Fiber Drawing
Following the pre-heating, the actual fiber drawing starts: For this purpose, the preform 3 is further heated. When the end of the preform 3 reaches a certain temperature, it is tapered due to gravity or by exerting a force with an appropriate tool and the end of the fiber cane 9 , fiber 10 or multi fiber rod 11 moves downward or upward, respectively, relative to the bulk of the preform 3 .
By means of a device attached below the radiation unit, e.g. a belt or clamping mechanism, the fiber cane 9 , fiber 10 or multi fiber rod 11 has to be moved away or rolled up from the tapered section 33 , so that a constant diameter of the fiber 10 or fiber cane 9 or multi fiber rod 11 is achieved. Certainly, this facility can also be turned around by 180°, so that the fiber 10 or fiber cane 9 or multi fiber rod 11 is upwardly moved away.
The crucial part of the facility is a radiation unit 7 with one or more heating zones built from a material, preferably quarzal, which is highly reflecting in the wavelength range of the radiation sources. For radiation source any type of short-wave radiators 8 , for instance halogen tungsten emitters or gas discharge lamps, can be utilized. The radiators 8 may advantageously be horizontally arranged essentially omega shaped radiation elements. Alternatively or additionally, vertically arranged straight radiators and/or round discharge bulbs may be provided as radiators 8 . Generally, the shape and arrangement of the radiators 8 may be adapted to the dimensions an shape of the radiation unit 7 and the preform 3 in order to obtain a homogeneous distribution of the radiation power. Separation discs (not shown in FIG. 1 ) having a centric bore through which the preform 3 is guided can be inserted into radiation units with multiple heating zones in order to prevent crosstalk between the zones.
The radiation unit 7 is provided with an reflecting insulation 13 to the outside to reduce energy loss and temperature inhomogeneities. The insulation 13 may advantageously comprise quarzal, which is both highly reflecting and heat insulating.
The facility 1 described above enables a semi-continuously draw of fiber canes 9 or fibers 10 or multi fiber rods 11 as desired from the preform 3 . With such a facility preforms 3 with a diameter of 115 mm have already been successfully drawn to multi fiber rods with a diameter of 25 to 76 mm.
FIG. 2 shows emission spectra of a radiator emitting at a temperature of 1500 K and of a radiator emitting at a temperature of 3000 K and absorption characteristics of Schott Glass' 8505 Glass. As can be seen from the emission spectra, a radiator emitting at a temperature of 3000 K emits radiation in a wavelength range of above 200 nm with maximum power at about 960 nm, whereas a conventional heater operated at 1500 K emits at considerably longer wavelengths above approximately 900 nm with maximum power at about 2000 nm. Considering the transmission characteristics of a typical glass like Schott Glass' 8505 Glass, a radiator emitting at a temperature of 3000 K is more favourable, as it emits more than 50% of its power within the transparency window of the glass in the wavelength range of 200 nm to 2700 nm. Thus, by employing a radiator emitting at a temperature of 3000 K a large penetration depth of the radiation can be achieved.
FIG. 3 shows wavelength dependent re-emission, absorption and transmission characteristics of electromagnetic radiation directed to a multi fiber rod 11 drawn out from the tapered section 33 of a preform 3 as shown in FIG. 1 . The fiber rod 11 of this example has a thickness of about 2.6 mm.
The scale of the axis of the ordinate denotes the percental contributions of the factors re-emission, absorption and transmission to the total amount of irradiated power. Apart from the wavelength ranges around two minor absorption edges at 1900 nm and 1400 nm, the absorption amounts to approximately 20% within the wavelength range of 500 nm to 2500 nm. Due to the small absorption of the thin fiber rod, homogeneous heating is achieved in the tapered section 33 in the region of the apex. Additionally, due to the low absorption, radiation coupled into the fibers of the fiber bundle is transported along the fibers, so that the radiation also reaches those sections of the preform which are not primarily heated homogeneously. In particular, the center portions of the non-tapered part of the preform is heated by this light guiding mechanism so that at least a partly homogenisation of the radiation distribution inside the preform is achieved.
FIG. 4 shows a cross sectional outline in a vertical plane extending across the center of a multi fiber bundle down draw apparatus according to the invention which is suitable for execution of the inventive method utilizing semi-homogeneous heating.
The apparatus 2 comprises holding means 17 for holding the preform 3 . The holding means 17 is movable by means of a driving gear in order to feed the preform 3 to the furnace.
Similar to the apparatus shown in FIG. 1 , the apparatus according to FIG. 4 comprises radiators 8 as heater means, whereby the radiators 8 preferably emit short wave IR, e.g., at a temperature of 3000 K with considerable power of more than 50% of the total radiation power in the wavelength range of 200 nm to 2700 nm. The radiators 8 may be solid state emitters such as halogen tungsten emitters and/or gas discharge and/or electric-arc emitters. Reflective insulation walls 13 are provided to reflect transmitted or re-emitted radiation back to the preform 3 .
Furthermore, the furnace 5 is divided into two heating zones 19 , 20 which are separated by a separation disc 15 . The first heating zone may advantageously be used to heat the preform 3 near to the drawing temperature. Subsequently, the preform 3 which is slowly inserted by the driving gear is heated up to the drawing temperature within the second heating zone 20 .
The apparatus 2 as shown in FIG. 4 is designed as a down-draw tower. However, it may as well be constructed as an up-draw tower as shown in FIG. 5 . Furthermore, the apparatus 2 may be adapted to be turned at least in part thereof by an angle of about 180° from a first angular position to a second angular position and is adapted to be used as a down draw apparatus in the first angular position and as an up draw apparatus in the second angular position.
Drawing means are provided to exert a drawing force onto the preform in order to draw a multi fiber cane 9 , multi fiber rod 11 or fiber 10 out of the preform. As well, a fiber rod 11 comprising a cladding may be formed from a preform 3 comprising a cladding tube surrounding at least in part a core of a multi fiber preform.
The drawing means of the example shown in FIG. 4 comprise motor driven drawing rollers 25 . Alternatively, a motor driven reel 27 may be provided as drawing means to exert a drawing force by reeling the drawn-out fiber 10 . As well, a pair of clamps may be provided as means to exert a drawing force in order to draw a large diameter rod greater than 10 mm out of the preform.
The drawing procedure is controlled by means of a control unit 21 controlling both the drawing means 25 , 27 and the driving gear 23 . Additionally, means for controlling the power for the radiation units and the temperature of the preform, particularly of the tapered section 33 may be provided.
A fiber rod 11 obtained by drawing a fiber bundle preform utilizing an apparatus as shown in FIG. 4 or 5 and by employing the inventive method of semi-homogeneous heating may itself be a fiber preform for further processing, particularly for a further drawing procedure. Thus, the apparatus 2 as shown in FIGS. 4 and 5 may advantageously be employed to process a multi fiber preform 3 , whereby
i) a multi fiber preform 3 is heated semi-homogeneously by means of the radiators a,
ii) the semi-homogeneously heated multi fiber preform 3 is drawn by means of the drawing rollers 25 ,
iii) the drawn multi fiber preform being a fiber rod 11 is separated at predetermined length intervals,
iv) a plurality of the drawn multi fiber preforms or fiber rods 11 which are separated according to step iii) are arranged in parallel forming a multi fiber bundle having an increased number of fibers. This multi fiber bundle obtained by steps i) to iii) is used as a new multi fiber preform 3 . Steps i), ii) and iii) may be repeated one or more times by drawing the respective new multi fiber preform 3 , until a multi fiber rod 11 is obtained having the desired number of fibers.
Additionally, the plurality of the drawn multi fiber preforms being a multi fiber rod 11 may be twisted at or after the drawing step. Twisting of the multi fiber rod may advantageously be carried out in order to produce fiber optical inverters.
A multi fiber rod 11 obtained by a respective drawing step may have a diameter of greater than 25 mm, greater than 50 mm, or even greater than 79 mm.
Besides of single fibers or fiber rods, other articles, particularly articles comprising fiber-optical components may be obtained which are formed at least in part or apt to be formed by a process according to the invention. In example, an article obtained by employing the inventive method whereby semi-homogeneous heating is applied may comprise an optical face plate, an optical taper, a photonic crystal fiber, a hollow fiber, a hollow fiber rod, an optical fiber inverter or fiber straight-through. Specifically, twisting the multi fiber rod 11 at or after the drawing step may advantageously applied in order to obtain a fiber optical inverter.
The draw apparatus as shown in FIGS. 4 and 5 or the facility as depicted in FIG. 1 may advantageously be adapted to work in a wide temperature range so as to enable drawing of many different materials including plastics and glass with the same apparatus. For instance, fiber canes 9 , fibers 10 or multi fiber rods 11 may be formed using the facility 1 or the multi fiber draw apparatus 2 , whereby more peripheral portions of the heated part of the preform have a temperature of between 290 K and 2000 K.
In FIG. 6 , temperature distributions along a cross sectional view extending perpendicular to the longest dimension of a square shaped multi fiber bundle preform are displayed before drawing and in the course of drawing the multi fiber bundle preform. The temperature distributions have been photographed by means of a digital camera. Darker areas in the images indicate lower temperatures. As can be seen from the image on the right hand side of FIG. 6 , radiation heating of a fiber bundle without tapered area results in a very inhomogeneous temperature distribution, whereby the temperature in the center portion of the bundle is lower than at the peripheral portion. This effects results from the low penetration depth of the radiation, although short wave infrared within the transparency window of the glass material has been applied. Thus, the non-tapered region of the preform is heated inhomogeneously by direct heating of the radiation sources.
On the other hand, the temperature distribution shown on the left hand side is nearly homogeneous. This effect results from a homogeneous heating of small-diameter parts of the tapered section of the preform. These parts are heated nearly homogeneously. The more homogeneous temperature distribution results from radiation coupled into the homogeneously heated parts of the tapered section and guided along the fibers into the inhomogeneously heated non-tapered section of the preform. Thus, semi-homogeneous heating has been applied, resulting in a nearly homogeneous temperature distribution across the entire cross section of the fiber bundle. However, there may still be small temperature differences between portions located in the middle and portions located at the periphery of the fiber bundle. Specifically, the temperature of a portion in the middle of the fiber bundle is lower than the temperature of a portion located at the periphery. It has been established, however, that the temperature gradient between a peripheral and a central portion within the heated part of a glass preform with a diameter of of more than 100 mm lies below 1 Kelvin per millimeter, whereby the central portion has a temperature of more than 580 K. Specifically, a preform with a diameter of 120 mm with a surface temperature or temperature of peripheral portions of about 630 K could be drawn easily using the inventive semi-homogeneous heating. The preform material is known to be drawable at temperatures of at least 595 K, appointing the minimum temperature at central portions of the preform. Thus, the preform has been heated with a temperature difference of 35 K at the most, resulting in a temperature gradient of less than 0.6 K/mm. In comparison, the maximum preform sizes that can be drawn with conventional heating are about 60 mm in diameter. If using a preform of the same glass, a surface temperature of 715 K has been measured, resulting in a temperature gradient of about 4 K/mm.
According to further experiments, the remaining temperature difference between more central and more peripheral portions within fiber bundles having diameters of at least 50 mm have been estimated to be 40 K at the most, whereby peripheral portions have a temperature of between 835 K and 915 K.
A heat-up time from a temperature of below 300 K up to more than 890 K of the peripheral portions of less than one hour could be applied without generating tension cracks. If drawing larger preforms, the heat-up period may be extended to less than 3 hours or less than six hours.
In the experiment illustrated in FIG. 6 , a preform having quadratic cross-sectional shape has been chosen. However, the invention utilizing semi-homogeneous heating works as well with preforms having other cross-sectional shapes, e.g., preforms with circular, elliptic, octagonal or hexagonal cross-sections.
While this invention has been described in conjunction with the specific embodiments described above, other modifications, alternatives and variations of the present invention may occur to one of ordinary in the skill in the art based upon a review of the present application and these modifications, including equivalents thereof, are intended to be included within the scope of the present invention.
REFERENCE SIGNS
1
Fiber drawing facility
2
Multi fiber bundle draw apparatus
3
Preform
5
Furnace
7
Radiation unit
8
Radiator
9
Fiber cane
10
Fiber
11
Multi fiber rod
13
Insulation
15
Separation disc
17
Preform holding means
19,
Heating zones
20
21
Control unit
23
Driving gear
25
Drawing rollers
27
Reel
31
Part of 3 inside of furnace 5
32
Part of 3 outside of furnace 5
33
Tapered section of 3 | A method of hot forming of at least a part of an article is provided. The article includes a material selected from the group consisting of transparent and semitransparent materials. The method includes semi-homogeneously heating at least a part of the article by radiation and forming the heated part of the article. | 2 |
BACKGROUND TO THE INVENTION
1. Field of the Invention
The invention relates to processes for using electrophotographic systems to make and assemble a number of color toned images to give a full color reproduction. More particularly the invention relates to the use of such systems to make accurate color proofs for the printing industry.
2. Background of the Art
Full color reproductions by electrophotography have been generally known for many years (e.g., U.S. No. 2,297,691) but no detailed mechanisms were described and the toners disclosed were dry powders. U.S. Pat. Nos. 2,899,335 and 2,907,674 pointed out that dry toners had many limitations with respect to image quality used for superimposed color images. Liquid toners were recommended for the purpose of improved image quality. These toners comprised carrier liquids which were of high resistivity, e.g. 10 9 ohm-cm or more, with colorant particles dipersed in the liquid, and preferably an additive intended to enhance the charge carried by the colorant particles. U.S. No. 3,337,340 disclosed that one toner deposited first may be sufficiently conductive to interfere with a succeeding charging step. It was claimed that the use of resins which are both insulative (resistivity greater than 10 10 ohm-cm) and a of low dielectric constant (less than 3.5) to cover each colorant particle was necessary to provide good images. U.S. No. 3,135,695 disclosed toner particles stably dispersed in an insulating aliphatic liquid, the toner particles comprising a charged colorant core encapsulated by an aromatic soluble resin treated with a small quantitiy of an aryl-alkyl material.
The use of metal soaps as charge contol and stabilizing additives to liquid toners is disclosed in many earlier patents (e.g. U.S. No. 3,900,412; U.S. No. 3,417,019; U.S. No. 3,779,924; U.S. No. 3,788,995). (Concern has also been expressed and corrective measures offered for the inefficient action experienced when charge control additives or other charged additives migrate from the toner particles into the carrier liquid (U.S. No. 3,900,413; U.S. No. 3,954,640; U.S. No. 3,977,983; U.S. No. 4,081,391; U.S. No. 4,264,699). In U.S. No. 3,890,240 it is disclosed that typical liquid toners known in the art have conductivities in the range 1×10 -11 to 10×10 -11 mho/cm. GB No. 2,023,860 discloses centrifuging the toner particles out of a liquid toner and redispersing them in fresh liquid as a way of reducing conductivity in the liquid itself. After repeating the process several times the conductivity of the liquid toner was reduced by a factor of about 23 and was disclosed as a sensitive developer for low contrast charge images.
In several patents the idea is advanced that the level of free charge within the liquid toner as a function of the mass of toner particles is important to the efficiency of the developing process. In U.S. No. 4,547,449 this measure was used to evaluate the unwanted charge buildup on replenishment of the toner during use, and in U.S. No. 4,606,989 it was used as a measure of deterioration of the toner on aging. In U.S. No. 4,525,446 the aging of the toner was measured by the charge present and it was shown how the charge was generally related to the zeta potential of the individual particles. U.S. No. 4,564,574, discloses chelating charge director salts onto the polymer, used in liquid toners and discloses measured values of zeta potential on toner particles. Values of 33 mV and 26.2 mV with particle diameters of 250 nm and 400 nm are given. The purpose of the salts is to improve stability of the liquid toner. A literature reference, "Research into the Electrokinetic Properties of Electrographic Liquid Developers", V. M. Muller et al, IEE on Industry Applications, vol. 1A-16, pages 771-776 (1980), treats the liquid toner system theoretically but also gives experimental results on certain toners. Using very small toner particles (all less than about 0.1 micron), zeta potentials in the range 15 mV to 99 mV with related conductivity ratios were used. These latter ratios appear to relate the conductivity of the toner immediately after the current is initiated to the conductivity value after prolonged passage of the current. The former values are believed to contain both toner particle and soluble ionic species conductivities; the latter is believed to be the basic conductivity of the carrier liquid after most of the added charged carriers have been deposited by the current flow. Finally in U.S. No. 4,155,862 the charge per unit mass of the toner was related to difficulties experienced in the art in superposing several layers of different colored toners. This latter problem was approached in a different way in U.S. No. 4,275,136 where adhesion of one toner layer to another was enhanced by an aluminum or zinc hydroxide additive on the surface of the toner particles.
Diameters of toner particles in liquid toners vary from a range of 2.5 to 25.0 microns in U.S. No. 3,900,412 to values in the sub-micron range in U.S. No. 4,032,463 U.S. No. 4,081,391, and U.S. No. 4,525,446, and are even smaller in the Muller paper. It is stated in U.S. No. 4,032,463 that the prior art makes it clear that sizes in the range 0.1 to 0.3 microns are not preferred because they give low image densities.
Liquid toners which provide developed images which rapidly self-fix to a smooth surface at room temperature after removal of the carrier liquid are disclosed in U.S. No. 4,480,022 and U.S. No. 4,507,377. These toner images are said to have higher adhesion to the substrate and to be less liable to crack. No disclosure is made of their use in multicolor image assemblies.
The art therefore discloses an awareness of the importance of the physical parameters of the liquid toner-conductivities, zeta potentials of toner particles, charge per particle or per unit mass of particles, and the localization of the charge on the particles. Most of the references above are concerned with the efficiency of liquid toners in the context of monochomatic image development. Only U.S. No. 4,155,862 and U.S. No. 4,275,136 are explicitly concerned with multicolor toned images, and only the first of these relates the quality of the multicolor toned assembly to the charge per gram of the toner particles.
SUMMARY OF THE INVENTION
The invention provides a process for making high quality color images by electrophotography, wherein two or more different colored toner images are assembled on a positively charged photoconductor and are then transferred to a receptor surface. Such a system provides the high degree of control necessary to ensure the levels of accuracy in registration and color rendition required by color proofing and other high quality multicolor imaging processes. The invention further provides for liquid toners which when used one overlaying another to make these multicolor images, give good reproduction without image distortion or density loss, e.g. give greater than 85% trapping. The assembled image layers are capable of transfer together to a receptor surface in one or two steps without image loss.
This disclosure shows that novel liquid toners of the present invention may be uniquely characterized by two parameters:
(a) more than 40% of the conductivity is contributed by the charged toner particles as opposed to the ionic species in solution in the carrier liquid,
(b) the charge on the toner particles is of such a magnitude that the zeta potential of the particles are within a defined range around +140 mV.
This disclosure further shows that in the production of multicolor images the efficiency of overlaying of such liquid toner developers is enhanced by the satisfaction of a third parameter requirement, namely
(c) toner particle compositions which form a continous film immediately after deposition on the photoconductor surface and removal of the carrier liquid.
Two related prior art patents U.S. No. 4,507,377 and No. 4,480,022 may be relevant to parameter (c) in that they disclose and claim Tg in the range 30° C. and -10° C. as a means to self-fix the deposited toner to a smooth surface without requiring a subsequent heating treatment; two other related patents (U.S. No. 4,525,446 and 4,564,574) and the Muller et al paper disclose the use of the parameter zeta potential as a descriptive mechanism of toner properties and disclose zeta potential values for toners. These patents use zeta potential values only to determine the sign of the charge on the toner particles, while the Muller paper has a wider interest particularly in the control of particle size and dispersion stability. The above patents and the Muller paper discuss the need to reduce the total number of charged species in solution in the carrier liquid without recognizing the importance the parameter (a) described above. None of these references presents the parameters either singly or in combination as requirements for faithful multicolor image reproduction when assembling two or more colored toners one on top of another on the photoconductor.
U.S. Pat. No. 4,547,489 is conscious of the requirement of designing the electrical properties of the liquid toner to obtain good overlay properties, but uses simple conductivity values and charge per unit mass of toner as the arbiters. It is shown in the present invention that these parameters are not definative of the required overlay properties. No combination of the references teaches the importance of the two or three parameters found necessary for good overlay properties and the levels and ranges specified here have not been disclosed in the art. Nowhere is it disclosed -hat all the toners in an overlay set must satisfy the parameters.
In addition to the three parameter requirements, the values of conductivity and related to it the solids concentration, and of toner particle size are shown to be of practical importance in any given example of a liquid toner.
In summary, the toners of the present invention comprise a pigment particle having on its exterior surface polymer particles usually of smaller average dimensions than said pigment particle, said polymer particles having charge carrying coordination moieties extending from the surface of said polymeric particles. Polymeric particles in the practice of the present invention are defined as distinct volumes of liquid, gel, or solid material and are inclusive of globules, droplets etc. which may be produced by any of the various known techniques such as latex, hydrosol or organosol manufacturing.
DETAILED DESCRIPTION OF THE INVENTION
In the practice of electrophotography it is more common to use negatively charged photoconductors than positively charged ones. It has been found, however, that static noise is a much more common difficulty with negatively charged photoconductors and is very difficult to eliminate. The present invention is directed towards high quality multicolor images, especially for proofing purposes, for which there is a low tolerance for the effects of static noise. The invention is therefore directed towards a process using positively charged photoconductors and positive-acting, toner development sometimes known as reverse toner development. The liquid toners of the present invention are therefore positively charged.
The liquid toners according to the invention comprise a carrier liquid having a resistivity of at least 10 13 ohm-cm and a dielectric constant less than 3.5, and dispersed in the carrier liquid, colored or black toner particles containing at least one resin or polymer conferring amphipathic properties with respect to the carrier liquid. Optionally at least one moiety is present which acts as a charge directing agent. The said resin or polymer may advantageously have a Tg of less than 25° and preferably less than -10°. We have found that examples of liquid toners represented in the art as positively charged, when used with a positively charged photoconductor, give unacceptable overlay properties of one toner over another, together with low image sharpness and low half tone dot quality. More precisely these prior art toners exhibit unacceptable flow of the toner during imaging which results in distortion of the produced images. Desorption of the charge director from the toner particles is also a common problem. It has been further found that these shortcomings are related to certain electrical and chemical parameters of the liquid toner used.
Liquid toners according to the invention are required to have the following two properties:
(a) a ratio of less than 0.6, preferably less than 0.5, more preferably less than 0.4 and most preferably less than 0.3 between the conductivity of the carrier liquid containing unwanted dissolved ionic species which is present in the liquid toner, and the conductivity of the liquid toner itself,
(b) toner particles with zeta potentials between +60 mV and +200 mV. Preferably the potentials have a narrow distribution with at least 80% of the particles being within the broad range and within +/-40 mV of the average zeta potential.
The liquid toner according to our invention preferably also should satisfy the following parameter,
(c) deposited toner particles have a Tg of less than 25°.
Additionally, it is advantageous if the toner has the following properties,
(d) substantially monodispersed toner particle size with an average diameter in the range 0.1 micron to 1.5 micron,
(e) a conductivity in the range 0.1×10 -11 mho/cm and 2.0×10 -11 mho/cm with solids concentration in the liquid toner in the range 0.1 wt. % to 2.0 wt. % and preferably 0.2 wt. % to 0.75 wt. %.
The liquid toners we disclose here are stable on keeping and maintain their good properties during use. They produce accurate color rendition by their ability to be overlayed one over another without distortion of the tone or color rendition of the individual toner layers. They give what is known in the printing art as a trapping factor with values greater than 85%. "Trapping factor" is defined as the percentage ratio of the amount of toner deposited over a previously deposited toner layer compared with the amount which would be deposited on the receptor surface free from any previous toner deposition. Finally, they give fast consistent toning action under reverse development conditions.
Another characteristic of the present invention that has previously been alluded to is the ability of the toners to form films rather than lumps of particles upon being deposited on the photoconductor and/or upon being transferred to a receptor sheet or intermediate transfer sheet. This film forming capability of the toners of the present invention is in part due to the capability of providing layer proportions of binder particles (the surrounding polymeric particles of latex, organosol or hydrosol) in the individual toner particles. The technology of U.S. Pat. No. 4,564,574 generally allows for the deposition of only very thin layers of polymer on the surface of the pigment (thought to be on the order of monolayer of the polymer molecules). This would at first glance see to provide for high color densities but there is a distinct problem with the technology. The low proportions of polymer/pigment do not facilitate good adhesion and cohesion of the toner parties. The coating efficiency is low, the toner of the prior art acting more like solid powder toners. The toners adhere only on the surface of the particles forming a porous or reticulated network rather than a film. The maximum proportions of polymer/pigment attainable by this method are about 1:1.
In the present invention, the range of proportions of polymer/pigment in the toner particles is between about 3:2 to 20:1, preferably 3:1 to 18:1, and most preferably between 3.5:1 and 15:1. These proportions enable more of the binder to flow during drying or fusion so that more film or plane-like characteristics exist in the toned image. Transfer of the image from the photoconductor is facilitated and there is a shinier character to the image.
These performance properties are a requirement for an electrophotographic system acceptable for proofing and are advantageous for any such system requiring high quality multicolor imaging. It is an important aspect of the invention that all the toners to be used as an overlay set must satisfy the requirements listed above.
These performance properties will now be related to the physical and chemical properties of the liquid toners which are disclosed above as satisfying these requirements.
(a) Conductivity of a liquid toner has been well established in the art as a measure of the effectiveness of a toner in developing electrophotographic images. A range of values from 1.0×10 -11 mho/cm to 10.0×10 -11 mho/cm has been disclosed as advantageous in U.S. No. 3,890,240. High conductivities generally indicated inefficient disposition of the charges on the toner particles and were seen in the low relationship between current density and toner deposited during development. Low conductivities indicated little or no charging of the toner particles and led to very low development rates. The use of charge director compounds to ensure sufficient charge associated with each particle is a common practice. There has in recent times been a realization that even with the use of charge directors there can be much unwanted charge situated on charged species in solution in the carrier liquid. Such unwanted charge produces inefficiency, instability and inconsistency in the development. It has been found in the present invention that at least 40% and preferably at least 80% of the total charge in the liquid toner should be situated and remain on the toner particles. Suitable efforts to localize the charges onto the toner particles and to ensure that there is substantially no migration of charge from those particles into the liquid, give substantial improvements. As a measure of the required properties, the present description uses the ratio between the conductivity of the carrier liquid as it appears in the liquid toner and the conductivity of the liquid toner as a whole. This ratio must be less than 0.6 preferably less than 0.4 and most preferably less than 0.3.
Prior art toners that have been examined have shown ratios much larger than this, in the region of 0.95.
(b) The charge carried by each of the toner particles is known in the art to be important in stabilising the dispersion of the particles in the carrier liquid especially upon long term storage. It has also been found that it is also a prime factor in ensuring the adhesion of the freshly deposited toner particles to the receiving surface whether this is the photoconductor or a previously deposited toner layer. It is believed that the adhesion is connected with the velocity with which the particle impinges on the imaging surface under the influence of the electric bias field produced by the development electrode in the reverse development procedure. The effectiveness of the charge in increasing mobility (and therefore the velocity under the influence of the electric bias field) of the toner particles in the environment of the carrier liquid is measured by the zeta potential of the particle. By definition the zeta potential is the potential gradient across the difuse double layer, which is the region between the rigid layer attached to the toner particle and the bulk of the solution (ref. Physical Chemistry of Surfaces, by Arthur Adamson, 4th.Edition, pages 198-200). The zeta potential was evaluated here from a measurement of toner particle mobility using a parallel plate capacitor arrangement. The capacitor plate area was large compared with the distance between the plates so as to obtain a uniform electric field E=V/d where V was the applied voltage and d the plate separation. The liquid toner filled the space between the plates and the current resulting from the voltage V was monitored with a Keithley 6/6 Digital Electrometer as a function of time. Typically the current was found to show an exponential decay due to the sweeping out of charged ions and charged toner particles. The legitimate assumption was made that the time constant for the toner particles was much longer than that for the ionic species and therefore the two values could be separated in the decay curves. If t is the time constant then the velocity (u) of the charged toner particles under the influence of the field E is u=d/t and the toner mobility (m) is m=u/E.
The zeta potential (z) is then given by z=3 sm/(2 ee o ) where s is the viscosity of the liquid, e o is the electric permitivity, and e is the dielectric constant of the carrier liquid. References in the literature to zeta potential of toner particles (U.S. No. 4,564,574 and Muller et al above) are limited to the stabilising effect of the zeta potential on the dispersion of the toner particles in the liquid. We found that the values given in the patent, 26 mV to 33 mV, are too small for the purposes of the present invention.
Although the zeta values in Muller et al are higher, and within the range of those recited in the practice of the present inventions, they are combined with conductivity values much lower than are required. It has also been found that the zeta potential should be relatively uniform in a given toner and be centered within the range +60 mV and +200 mV.
(c) It has been found that toners which remain in a particulate form after deposition on the photoconductor surface or over a previously deposited toner are not satisfactory. Overprinting capability of a toner is related to the ability of the toner particles to deform and coalesce into a resinous film. The coalesced particles permit the creation of a new electrostatic latent image immediately after development so that another image can be overprinted.
Non-coalesced particles tend to retain charge because of poor contact with the surface on which they are deposited, and can prevent proper charging of the photoconductor for the next image. Coalesced particles also tend to form a non-scattering layer with more acceptable optical properties.
It is known in the art to heat toners after deposition to coalesce them into a film, but in the process of this invention the necessity to apply a heat treatment between each of the toner developments would be a serious disadvantage and could interfere with the proper action of the photoconductor. The ability of the deposited toner particles to coalesce and film-form at a given temperature is known to be related to the glass transition temperature, Tg, of the resins or polymers involved (U.S. No. 4,024,292). The resins or polymers used in the toner particles of the invention are therefore defined as having Tg values less than about 25° C. and preferably less than -10° C. so that they coalesce and form a film at the ambient temperature of the process after removal of the carrier liquid at a coating thickness of less than 0.3 microns. This film forming ability can be observed on polyethyleneterephthalate at room temperature.
The coalescence of the toner particles of the invention although not causing unacceptable flow of the deposited image, does give advantageous smoothing of image edges on a microscopic scale. Half-tone dot images formed by laser scan methods frequently have castellated edges unless very high resolution scanning is employed. The toners of the invention in the process of coalescing after deposition smooth out the castellations and give the type of dot favored for burning half-tone plates and which printing personnel regard as a necessary quality.
(d) Size and uniformity of size of the toner particles are important to both the film-forming properties and the zeta potential effectiveness; smaller particles will in general coalesce more easily and, however, higher velocities are obtained with larger ones. Toner particle diameters in the sub-micron range are well known in the art but are mostly in the range of 0.5 micron or more, and in fact some references declare there are difficulties with image density if the size is less than about 0.3 micron. We have found that diameters from about 0.1 microns through to about 0.7 microns are not only acceptable, but that the smaller sizes in the range of from about 0.1 through about 0.3 microns are often advantageous in film-forming and in zeta potential requirements. Typically in the present invention, all size ranges have size distributions of the particles with a standard deviation of less than 25%.
(e) With the conductivity ratios specified above for the present invention, the conductivity of the liquid toner should be in the range 0.1×10 -11 and 2.0×10 -11 mho/cm and preferably should be in the range 0.1×10 -11 and 0.5×10 -11 mho/cm. Thus the conductivities and the conductivity ratio of a toner according to the present invention are both substantially lower than levels commonly found in the prior art.
The conductivities are also related to the concentration of the charged toner particles in the liquid toner at working strength. Concentration of solids in the range 0.1 wt. % to 2.0 wt. % are generally permissible in this invention. At higher values the development is normally too fast and gives high background development together with a lack of control of maximum density. Values below 0.1 wt. % give very low development rates and therefore lead to incomplete development in the times alloted in the process. The preferred range of concentrations in the liquid toners are found to be 0.2 wt. % to 0.75 wt. %.
It is a requirement of the invention that the physical and chemical properties (a) & (b) should be all satisfied in a liquid toner if the performance requirements of color proofing are to be met. For highest quality images the requirements of parameter (c) should also be met. Ranges of the properties (d) and (e) provide further advantages but are not presented here as definative for high quality multicolor overlay images.
Multicolor electrophotographic processes are herein disclosed in which all of the different toners used satisfy the requirements disclosed above, and thereby ensure good overlay of the successive toner images and give high quality image characteristics. A description of suitable apparatus and processes in which the toners of this invention may be used is to be found in U.S. Pat. No. 4,728,983, which is hereby incorporated by reference. One embodiment of the process and apparatus was as follows.
A metal drum 2 of diameter 20 cm and length 36 cm rotated on journals supported on a substantial frame (not shown) driven by a DC servo motor with encoder and tachometer 10 controlled in speed to 0.42 revolutions per minute by speed controller 12. A layer of photoconductor 4 coated on a plastic substrate 6 having an electrically conductive surface layer, was wrapped around the drum 2 and fixed firmly to it and grounded. The photoconductor comprised bis-5,5'-(N-ethylbenzo(a)carbazolyl)-phenylmethane (BBCPM) in a Vitel PE207 polyester binder, sensitized with an indolenine dye having a peak absorption in solution at a wavelength of 787 nm.
Infra-red light of power 2 mw and wavelength 780 nm emitted by self-modulated laser diode 14 was focused by lens system 16 onto the the photoconductor surface at 38 as a spot with 1/2 Imax diameter of about 30 microns. The focused beam 40 modulated by signals supplied from memory unit 34 by control unit 32 to laser diode 14, was directed to a rotating two-surface mirror 18 driven by motor 36. The mirror speed of 5600 revolutions per minute and the synchronization of its scans with the image signals to the laser diode 14 were controlled accurately by the control unit 32. The sensor 12 supplied to the control unit 32 signals for start of cycle of rotation of the drum 2 which were used to commence signals to the laser diode 14 for the beginning of picture frame information.
The scorotron 20 charged the surface of the photoconductor 4 to a voltage of about +700 immediately before the exposure point 38. The toning developer unit 22 contained four identical units 24 containing respectively black, cyan, magenta, and yellow liquid toner. In each unit 24 there were means to supply the toner to the surface of a roller 26 which was driven at the same surface speed as the drum 2. Motor means 30 enabled any desired toner station to be selected to engage the roller 26 with the surface of the photoconductor at 28 so that toner was applied to the surface. Means were provided to apply a bias voltage of +350 between the roller 26 and the electrically conducting layer 8.
The complete cycle was repeated for each of the required color separation images. Four color images were laid down in register in the order black, cyan, magenta, and yellow and the resulting assembly transferred to a receptor paper 42 by actuating the drive roller 44 heated to 1200 C and engaging the receptor surface with the photoconductor surface at a pressure of 1.79 kg/cm after the fourth toner image had been laid down. The resulting four color half-tone picture was found to have a highly accurate registration between the separation images and a high level of color fidelity.
The toners of the present invention have low Tg values with respect to most available toner materials. This enables the toners of the present invention to form films at room temperature. It is not necessary for any specific drying procedures or heating elements to be present in the apparatus. Normal room temperature 19°-20 ° C. is sufficient to enable film forming and of course the ambient internal temperatures of the apparatus during operation which tends to be at a higher temperature (e.g. 25°-40° C.) even without specific heating elements is sufficient to cause the toner or allow the toner to form a film. It is therefore possible to have the apparatus operate at an internal temperature of 40° C. or less at the toning station and immediately thereafter where a fusing operation would ordinarily be located.
EXAMPLES
A. Properties of Commercial Liquid Toners
Example 1
Liquid toner concentrates from Hunt Chemical Company were evaluated as follows.
Magenta SN-7102C diluted 40 g/L
Cyan SN-7102B diluted 40 g/L
Yellow SN-7102A diluted 40 g/L
The toners were drip diluted and allowed to set overnight before imaging. Measured conductivities were:
Magenta: 10.4×10 -11 mho/cm
Cyan: 8.9×10 -11 mho/cm
Yellow: 5.4×10 -11 mho/cm
These toners were imaged onto an organic receptor layer comprising BBCPM charged to +520 volts and discharged with a laser scanner emitting light of wavelength 633 nm to a potential of +60 volts at 1500 scan lines per inch. Reverse development mode was used with a gap of 15/1000 inch between the electrode and the photoconductor the bias potential of the electrode being +350 volts. Dwell time between the development electrodes was 1.5 seconds. The developed images were transferred to a coated paper and evaluated. Each toner as laid down showed a tendancy to flow, thus giving unsharpness and reduced contrast, and there was some appreciable background developed. Attempts to lay down one toner over another with the cyan toner last, were not successful.
Example 2
Liquid toners from Panacopy were evaluated.
Concentrates of magenta, cyan, and yellow toners were diluted to 0.1 wt. % with Isopar G, and held overnight after thorough shaking.
Conductivities of these liquid toners were measured (ctot mho/cm).
Samples of each were centrifuged at 15,000 rpm for 30 mins. to precipitate all solids; conductivities of the remaining liquids were measured (cres mho/cm).
Mobilities and zeta potentials for the toner particles in each of the toners were measured as described above in the detailed description of the invention. Values found were as follows:
______________________________________Toner m cm2/volt.sec zeta mV______________________________________Magenta 1.15 × 10.sup.-5 114Cyan 0.88 × 10.sup.-5 87Yellow 0.94 × 10.sup.-5 94______________________________________
Measured conductivities and ratios were as follows:
______________________________________Toner ctot cres cres/ctot______________________________________Magenta 1.27 × 10.sup.-11 0.86 × 10.sup.-11 0.68Cyan 2.6 × 10.sup.-11 2.28 × 10.sup.-11 0.88Yellow 1.55 × 10.sup.-11 0.84 × 10.sup.-11 0.54______________________________________
Although all of these liquid toners have zeta potentials in the range we claim to be effective for good overlay properties, only one of these toners has a conductivity ratio which is low enough to satisfy our requirement (a), and that is marginal. None of these toners was film-forming at room temperature. This set of toners did not overprint successfully when used in an imaging system similar to that described in Example 1, thus indicating that all the toners in an overlay set must satisfy the requirements put forward in this invention. The liquid toners themselves had low stability and had separated after 3 days standing.
B. Properties of Liquid Toners of the Invention.
These examples relate to liquid toners made by the procedures given in the later examples. These toners were based on small organosol particles surrounding a pigment particle and having attached chelating moieties to which metal soap charge generators were chelated. The inner core of the organosol particles was insoluble in the carrier liquid whereas the outer linking groups were compatible with said liquid thus giving a stable dispersion. Compatibility means the ability of the materials to be associated without rejection, as by dispersibility, solubility, or other physical association. The presence of polar groups for a polar solvent or non-polar group for a non-polar solvent will provide this effect. The metal soap charge generators were firmly attached to the organosol by chelating action so that their migration into the body of the liquid was precluded.
Example 3
A four-color set of toners based on the preparations of Example 4 below were made using hydroxyquinoline (HQ) as a chelating agent for attaching the charge generator, and having an ethylacrylate core of Tg=-12.5° C. Measured properties were:
__________________________________________________________________________SAMPLE Ctot × 10.sup.11 Cres × 10.sup.11 RATIO M × 10.sup.5 ZETA mV SOLIDS__________________________________________________________________________BLACK 0.95 0.33 0.35 1.01 86.3 0.6 wt. %MAGENTA 0.53 0.22 0.42 0.71 60.7 0.3 wt. %CYAN 0.57 0.14 0.25 1.34 114.3 0.3 wt. %YELLOW 0.75 0.19 0.25 1.37 117.0 0.3 wt. %__________________________________________________________________________ A similar toner prepared with carboxyhyroxybenzylmethacrylate-salicylate (CHBM) as a chelate for attaching the charge generator had the following properties: polyethylacrylate core still gave Tg=- 12.5° C. and
______________________________________YELLOW 0.76 0.43 0.57 1.21 103.4 0.3 wt. %______________________________________
Yet another similar toner made with CHBM and with a polymethylacrylate core of Tg=13° C. had properties:
______________________________________MAGENTA 0.52 0.28 0.54 1.11 94.9 0.3 wt. %______________________________________
Any selection of these liquid toners used to produce multitoned images by the methods disclosed herein was found to give very good overlay properties.
C. Preparation of Liquid Toners of the Invention
Preparation of an organosol consists of four steps:
(a) Preparation of stabilizer precurser
(b) Addition reaction of a coupling reagent, e.g., hydroxyethylmethacrylate
(c) latex formation by polymerization of the stabilizer (a & b above) with core monomer
(d) addition of metal soap for chelation and toner charge generation.
EXAMPLE 4
This is illustrated in the preparation of a lauryl methacrylate/salicylate (CHBM) stabilizer; ethyl acrylate core latex.
Preparation of a stabilizer containing salicylic acid groups
1. Preparation of a stabilizer precurser: In a 500 ml 2-necked flask fitted with a thermometer, and a reflux condenser connected to a N 2 source, a mixture of 95 g of lauryl methacrylate, 2 g of 2-vinyl-4,4-dimethylazlactone (VDM), 3 g of CHBM, 1 g of azobis-isobutyronitrile (AIBN), 100 g of toluene and 100 g of ethylacetate was introduced.
The flask was purged with N 2 and heated at 70° C. for 8 hours. A clear polymeric solution was obtained. An IR spectra of a dry film of the polymeric solution showed an azlactone carbonyl at 5.4 microns.
2. Reaction of (1) above with 2-hydroxyethylmeth-acrylate (HEMA):
A mixture of 2 g of HEMA, 1.5 g of 10% p-dodecylbenzene sufonic acid (DBSA) in heptane and 15 ml of ethyl acetate was added to the polymer solution of (1) above. The reaction mixture was stirred at room temperature overnight. The IR spectra of a dry film of the polymeric solution showed the disappearance of the azlactone carbonyl peak, indicting the completion of the reaction of the azlactone with HEMA.
Ethyacetate and toluene were removed from the stabilizer by adding an equal volume of Isopar G# and distilling the ethylacetate and the toluene under reduced pressure. The polymeric solution looked turbid. The polymer solution was filtered through Whatman filter paper #2 to collect the unreacted salicylic acid. There was no remaining solid on the filter paper, indicating that all the CHBM has been incorporated. The turbidity may have been due to the insolubiltiy of the pendant salicylic groups.
Preparation of Latices
3. General Procedure:
To a 2L - 2 necked flask fitted with a thermometer and a reflux condenser connected to a N 2 source, were introduced a mixture of a 1200 ml of Isopar G™, a solution of a stabilizer of the above examples containing 35 g of solid polymer, 1.5 g of AIBN and 70 g of the core monomer*. The flask was purged with N 2 and heated at 70° C. while stirring. The reaction temperature was maintained at 70° C. for 22 hours. A portion of the Isopar G™ was distilled under reduced pressure.
4. Preparation of metal chelate latices
(20% zirconium neodecanoate in Isopar G™)
To a hot solution of the metal soap in Isopar G™ (reactions conditions are shown in table III) was added portionwise a latex (10% by weight in Isopar G™) containing 1 (wt)% cf a coordinating compound equimolar with the metal soap present in the hot isopar solution. The mixture was heated for 5 hour at 60° C.
Resultant latex had a core Tg-12.5° C. and an overall particle size =197 +/-47 mm.
PIGMENTS
Commercial pigments (Sun Chemical) were purified prior to dispersing with the chelate organosols. For example Sun Chem. Cyan 249-1282 was soxhlet extracted with ethanol (EtOH) or EtOH/Toluene 80/20 mix until the extracted liquid was clear (24-72 hrs). Then the solvent-wet pigment was stirred with Isopar G™ to make the percent solids 10-20%. While the slurry was stirring the temperature was kept at 75°-95° C. and N 2 is bubbled through for 4-6 hours to drive off any excess extraction solvents. The resultant pigment--Isopar G slurry was used for toner prepration.
TONER PREPARATION
Example 5
A weight ratio of 2:1 to 10:1 organosol to pigment was blended together and then mechanically dispersed, usually by said milling or silversion mixer. The dispersion was kept at a temperature of between 40° C. and 30° C. and normally took 4-6 hours to disperse. The resultant toner (e.g. Cyan) had the following properties.
______________________________________Particle Size Cond(0.3% wt) Cond Ratio Zeta Pot______________________________________220 +/- 40 nm 0.9 × 10.sup.-11 mho/cm 0.57 76.8 mV______________________________________
The resultant mill base had a weight percent in the range of 8-10.0%. Toners were prepared by dilution with Isopar G™ to 0.3% wt.
The preferred stabilizer precursor used in the present invention is a graft copolymer prepared by the polymerization reaction of at least two comonomers. At least one comonomer is selected from each of the groups of those containing anchoring groups, and those containing solubilizing groups. The anchoring groups are further reacted with functional groups of an ethylenically unsaturated compound to form a graft copolymer stabilizer. The ethylenically unsaturated moieties of the anchoring groups can then be used in subsequent copolymerization reactions with the core monomers in organic media to provide a stable polymer dispersion. The prepared stabilizer consists mainly of two polymeric components, which provide one polymeric component soluble in and another component insoluble in the continuous phase. The soluble component constitutes the major proportion of the stabilizer. Its function is to provide a layophilic layer completely covering the surface of the particles. It is responsible for the stabilization of the dispersion against flocculation, by preventing particles from approaching each other so that a sterically-stabilized colloidal dispersion is achieved. The anchoring group constitutes the insoluble component and it represents the minor proportion of the dispersant. The function of the anchoring group is to provide a covalent-link between the core part of the particle and the soluble component of the steric stabilizer.
Graft copolymer stabilizer precursors have been prepared by the polymerization of comonomers of unsaturated fatty esters (the solubilizing group) and alkenylazlactones (the anchoring group) of the structure ##STR1## where R 1 =H, alkyl less than or equal to C 5 , preferably C 1 ,
R 2 , R 3 are independently lower alkyl of less than or equal to C 8 and preferably less than or equal to C 4 ,
R 4 , R 5 are independently selected from a single bond, a methylene, and a substituted methylene having 1 to 12 carbon atoms,
R 6 is selected from a single bond, R 7 , and ##STR2## where R 7 is an alkylene having 1 to 12 carbon atoms, and W is selected from 0, S and NH,
in a non-polar organic liquid, preferably an aliphatic hydrocarbon, in the presence of at least one free radical polymerization initiator. The azlactone constitutes from 1-5% by weight of the total monomers used in the reaction mixture.
Examples of comonomers contributing solubilizing groups are lauryl methacrylate, octadecyl methacrylate, 2-ethylhexylacrylate, poly(12-hydroxystearic acid), PS 429 (Petrarch Systems, Inc., a polydimethylsiloxane with 0.5-0.6 mole % methacryloxypropylmethyl groups, which is trimethylsiloxy terminated).
When polymerization is terminated, the catalyst (1-5 mole % based on azlactone) and an unsaturated nucleophile (generally in an approximately equivalent amount with the azlactone present in the copolYmer) are added to the polymer solution. Adducts are formed of the azlactone with the unsaturated nucleophile containing hydroxy, amino, or mercaptan groups. Examples of suitable nucleophiles are
2-hydroxyethylmethacrylate
3-hydroxypropylmethacrylate
2-hydroxyethylacrylate
pentaerythritol triacrylate
4-hyroxybutylvinylether
9-octadecen-l-ol
cinnamyl alcohol
allyl mercaptan
methallylamine
The mixture is well stirred for several hours at room temperature. Catalysts for the reaction of the azlactone with the nucleophite that are soluble in aliphatic hydrocarbons are preferred. For example p-dodecylbenzene sulfonic acid (DBSA) has good solubility in hydrocarbons and was found to be a very effective catalyst with hydroxyfunctional nucleophiles. In the case of immiscible nucleophiles such as hydroxyalkylacrylate, strong stirring is sufficient to ensure emulsification of the nucleophile in the polymer solution. The completion of the reaction is detected by taking the IR spectrum of successive samples during the reaction period. The disappearance of the azlactone carbonyl characteristic absorption at a wavelength of 5.4 microns is an indication of 100% conversion.
The azlactone can be employed in the preparation of graft copolymer stabilizers derived from poly(l2-hydroxystearic acid) (PSA). This may be achieved by reacting the terminal hydroxy group of PSA with for example 2-vinyl-4,4-dimethyl-2-oxazolin-5-one (VDM) to give a macromonomer, and then copolymerizing the latter with methyl-methacrylate (MMA) and VDM in the ratio of nine parts of MMA to one of VDM, followed by the reaction of a proportion of the azlactone groups with an unsaturated nucleophile, such as 2-hydroxyethylmethacrylate (HEMA).
The preparation of latices (organosols), by using graft copolymer stabilizers containing azlactone as anchoring sites, can be achieved using any type of known polymerization mechanism free radical, ionic addition, condensation, ring opening and so on. The most preferred method is free radical polymerization. In this method, a monomer of acrylic or methacrylic ester together with the stabilizer and an azo or peroxide initiator is dissolved in a hydrocarbon diluent and heated to form an opaque white latex. Particle diameters in such latices have been found to be well below a micron and frequently about 0.1 micron.
Example I
A. Preparation of a stabilizer precursor based on poly(2-ethylhexyl acrylate-co-VDM) 98:2 w/w
In a 500 ml 2-necked flask fitted with a thermometer, and a reflux condenser connected to a N 2 source, were introduced a mixture of 98 g of 2-ethylhexylacrylate, 2 g of VDM , 1 g of azobisisobutyronitrile (AIBN) and 200 g of Isopar G™ (a mixture of aliphatic hydrocarbons marketed by Exxon and having high electrical resistivity, dielectric constant below 3.5, and boiling point in the region of 150° C.). The flask was purged with N 2 and heated at 70° C. After about 10 minutes of heating, an exothermic polymerization reaction began and the reaction temperature climbed to 118° C. The heating element was removed, and the reaction mixture was allowed to cool down without external cooling. When the reaction temperature dropped to 65° C., the heating element was replaced and the reaction temperature was maintained at that temperature over-night and the reaction mixture was then cooled to room temperature. A clear polymeric solution was obtained. An IR spectrum of a dry film of the polymeric solution showed an azlactone carbonyl peak at 5.4 microns.
B. Preparation of graft copolymer stabilizer by reacting the result of A above with 2-hydroxyethyl methacrylate (HEMA).
A mixture of 2 g of HEMA, 1.5 g of 10% p-dodecylbenzene sulfonic acid in heptane and 15 ml of ethylacetate was added to the polymer solution of (A) above. The reaction mixture was stirred at room temperature over-night. An IR spectrum of dry film of the polymeric solution showed the disappearance of the azlactone carbonyl peak.
C. Preparation of polyvinylacetate latex using stabilizer B above.
In a 250 ml 2-necked flask fitted with a thermometer and a reflux condenser connected to a N 2 source was placed 70 g of Isopar G™, 11 g of stabilizer B above, 0.5 g of AIBN and 33.3 g of vinylacetate. The stirred reaction mixture was heated gently to 85° C. under N 2 atmosphere. After 10 minutes of heating, an exotherm started and the temperature climbed to 100° C. A small amount of petroleum ether was added to lower the reaction temperature to 85° C. Heating was continued for 3 hours, then 200 mg of AIBN was added and the reaction temperature was maintained at 85° C. for 3 hours. A portion (about 20 ml) of the Isopar G™ was distilled off under reduced pressure. A white latex with particle size of 0.18±0.05 micron was obtained.
D. Preparation of polyethylacrylate latex using stabilizer (B) above
In a 1 liter 2-necked flask fitted with a thermometer and a reflux condenser connected to a N 2 source, was introduced a mixture of 425 g of Isopar G™, 50 g of stabilizer (B) above, 35 g of ethylacrylate and 0.5 g of AIBN. The flask was purged with N 2 and heated at 70° C. while stirring. The reaction temperature was maintained at 70° C. for 12 hours. A portion of Isopar G™ was distilled off under reduced pressure.
A white latex with particle size of 96 nm±15 nm was obtained.
E. Preparation of poIymethacrylate latex using stabilizer B above.
This latex was prepared as in D above using methylacrylate instead of ethylacrylate.
F. Preparation of polymethylmethacrylate latex using stabilizer B above.
This latex has been prepared by two methods.
Method-1
As in D above, using methylmethacrylate instead of ethylacrylate.
Method-2
A 250 ml 3-necked flask fitted with a thermometer, reflux condenser and dropping funnel was charged with:
Seed stage--a mixture of:
12 g of methylmethacrylate (MMA)
11 g of stabilizer of example IB
200 mg of AIBN
5 g of Isopar G™
30 ml of petroleum ether 35°-60° C.
The stirred mixture was heated to reflux at 81±° C. The temperature was maintained by evaporating or adding petroleum ether as necessary. After 15 min. of refluxing, the mixture turned white, indicating that a latex particle formation had occurred, after which the following mixture was added:
Feed stage--a mixture of:
20 g MMA
5 g stabilizer of example IB
120 mg AIBN
0.2 g lauryl mercaptane (10% in Isopar G™)
10 g Isopar G™
7 g petroleum ether 35°-60° C.
The mixture was added at a constant rate over a period of 3 hours. After the addition was finished, refluxing was continued for another half hour. After cooling to room temperature, the petroleum ether was distilled off under reduced pressure. The resulting product was a white latex with a particle size of 0.15±0.05 micron.
Example II
A. Preparation of a stabilizer precurser based on poly (Laurylmethacrylate-co-VDM) 96:4 w/w
In a 500 m) 2-necked flask fitted with a thermometer and a reflux condenser connected to a N2 source, was introduced a mixture of 96 g of laurylmethacrylate, 4 g of VDM, 1 g of AIBN and 200 ml ethylacetate. The flask was purged with N 2 and heated at 70° C. for 12 hours. An IR spectrum of a dry film showed an azlactone carbonyl peak at 5.4 micron.
B. Preparation of graft copolymer stabilizer by reacting a portion of the azlactone groups with HEMA and the remainder with a different nucleophile
1. Attaching a nucleophile of coordinating compound:
a. Attaching 2-hydroxyethylsalicylate: A mixture of 1.4 g of HEMA, 3.27 g of 2-hydroxyethylsalicylate and 2 g of 10% DBS in heptane was added to the polymeric solution of example II A above and the reaction mixture was stirred over-night at room temperature. An IR spectrum of a dry film of the polymeric solution showed the disappearance of 95% of the azlactone carbonyl-only. The primary hydroxy groups of the salicylate compound apparently participate in the reaction with the azlactone groups.
b. Attaching 4-hydroxyethyl-4,-methyl-2,2'-bipyridine:
Example IIB 1-a was repeated except using 0.018 mole of the bipyridine compound instead of the salicylate compounds and 0.3 g of 1,8-diazabicyclo [5,4,0] undec-7-ene as a basic catalyst instead of DBSA. After 24 hours of stirring at room temperature, an IR spectrum showed the disappearance of >85% of the azlactone carbonyl peak.
c. Attaching 4-hydroxymethylbenzo-15-crown-5
Example IIB 1-a was repeated except 0.018 mole of 4-hydroxymethylbenzo-15-crown-5 was used instead of the salicylate compound.
2. Attaching nucleophiles of chromophoric substances.
Example IIB 1-a was repeated using 0.018 mole of 4-butyl-N-hydroxyethyl-1,8-naphthalimide instead of the salicylate compound.
C. Preparation of latices from the stabilizer of example II.
Ethylacetate was removed from the stabilizer by adding an equal volume of Isopar G™ and distilling the ethylacetate under reduced pressure. A clear polymeric solution in Isopar G™ was obtained. Latices were prepared from these stabilizers according to example I-D, E, F.
Example III
This example illustrates the preparation of latex particles having attached ethylenically unsaturated groups t the soluble moiety of the particle.
A. Preparation of a stabilizer precursor based on Poly(Lauryl meth-acrylate-co-VDM) 92:8 w/w
This copolymer was prepared according to example II-A from 92 g of laurylmethacrylate, 8 g VDM and 1 g of AIBN in 200 g of Isopar G™. A clear polymeric solution was obtained.
B. Preparation of graft copolymer stabilizer by reacting a proportion of the azlactone groups with HEMA
A mixture of l.4 g of HEMA, 1 g of 10% DBS in heptane and 15 ml of ethylacetate was added to the polymeric solution of example III-A above. The reaction mixture was stirred over night at room temperature. An IR spectrum of a dry film of the polymeric solution showed a decrease in the azlactone carbonyl peak by about 25%.
C. Preparation of a latex from stabilizer B above:
This latex is prepared according to example I-D from 50 g of stabilizer B above, 35 g ethylacetate, 0.5 g of AlBN and 425 g of Isopar G™. A white latex with particle size of 95 nm+/-5 nm was obtained. Aa portion of the Isopar G™ (about 25 ml) was distilled off.
D. Attaching pentaerythritol triacrylate
A mixture of 2 g pentaerythritoltriacrylate, 2 g of 10% DBSA in heptane and 15 ml ethylacetate was added to the polymer dispersion of C above. The mixture was stirred over night at room temperature. An IR spectrum showed the disappearance of the azlactone carbonyl peak. | Liquid toners are generally recognized as being capable of providing sharper electrophotographic images, but have been found to provide less than desirable results in multicolor imaging processes. The selection of a unique combination of (a) the ratio of conductivities between the toner liquid and the total toner composition, and (b) the zeta potential of the toner particles in the carrier liquid have been found to provide unique benefits to the quality of the liquid tone multicolor images. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a method for diffusion bonding of ceramics, and in particular to a method for forming internal cavities of small dimensions in ceramics by bonding ceramic bodies together.
2. Description of the Background Art
Ceramic microwave components such as phase-shifters and latching switches for use in microwave devices utilize shapes such as toroidal configurations having internal cavity dimensions which are dictated in part by the frequency of the microwaves with which the components are to be used. As present technology advances toward very high frequencies, holes are required in the ceramics having diameters on the order of 0.05 centimeters or less. When such small diameter holes are required with lengths greater than 0.6 cm., it has been found that conventional methods will not reliably produce the desired parts. Such methods include drilling with diamond tipped tools, pressing ceramic powder around a mandrel which is removed before final firing, pressing powder around a burnout insert which is consumed during firing, and laser cutting and drilling of previously fired ceramic masses. These techniques, while useful, especially where small dimensions are not necessary, produce such shortcomings as warping during forming and firing which causes unacceptable dimensional variances. In addition, cracking of parts during firing causes parts to be rejected as unusable after they have been machined. Moreover, intricate shapes are not attainable, and, as pointed out above, holes of small diameter are difficult, if not impossible to produce except in short lengths.
Therefore, it is an object of this invention to provide a method which overcomes the aforementioned inadequacies of the prior art methods and provides an improvement which is a significant contribution to the advancement of the ceramic arts.
Another object of this invention is to permit the forming of cavity configurations in a ceramic body having dimensions usable for microwave components.
It is also an object of this invention to provide a method which will result in a higher percentage of usable parts when small internal cavity configurations are incorporated.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
The invention is a method wherein the desired cavity configuration is formed on a polished, flat surface of one piece of ceramic which has already been fired to the point of optimum (greater than 95% of X-ray) density. The desired cavity configuration may be formed by machining or, in the case of more intricate shapes, by using a pantograph machine or laser. This surface is then placed in intimate contact with a similarly sized flat, polished surface of a second piece of ceramic and the two pieces are then fired to their maturing temperature, thereby forming a unitary ceramic body containing the desired cavity configuration. Large numbers of patterns may be formed on a single ceramic piece, and, after bonding to the second piece, individual patterns may be sliced off. Unless the mating surfaces are flat with respect to one another on the order of two light bands, pressure may be applied to maintain the desired juxtapositioning of the two ceramic pieces during firing.
The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific method disclosed may be readily utilized as a basis for modifying or designing other methods for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent methods do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 represents a ceramic body partially prepared in accordance with the invention;
FIG. 2 represents a ceramic body at a further stage of preparation in accordance with the invention;
FIG. 3 represents ceramic bodies positioned for further processing in accordance with the invention;
FIG. 4 shows a completed toroid formed in accordance with the invention; and
FIG. 5 is a photomicrograph of a toroid fabricated in accordance with the invention.
Similar reference characters refer to similar parts through the several views of the drawings.
DETAILED DESCRIPTION OF THE INVENTION
Fabrication of ceramic members which will have desired dimensions when completed is difficult, particularly when powdered ceramic materials are being formed by sintering. A lack of uniformity in packing density and uneven rates of heating tend to cause distortion during firing. With some products, forming processes such as the machining of external shapes may be performed after firing. Internal cavity configurations, traditionally formed by molding techniques, are not readily achieved after firing where small dimensions are involved.
The present invention overcomes the problem of distortion during firing by performing machining or other forming operations after the ceramic body has already been fired sufficiently to reach optimum density. Optimum density, as used herein, is density in excess of 90 percent of theoretical maximum density.
FIG. 1 shows ceramic body 10 which has been pressed into the general configuration illustrated and then fired to reach optimum density. After this firing, surface 12 of body 10 was next machined to remove surface irregularities. Surface 12 was then lapped to obtain a flat surface and then polished to a mirror finish using 1 μm grain size diamond abrasive or other suitable abrasive.
FIG. 2 shows ceramic body 14 which has already undergone the process steps of body 10 of FIG. 1. In addition, groove 16 has thereafter been formed in the flat, polished face 18. Groove 16 may be formed using any well known techniques for forming in ceramic bodies which have been fired, such as sawing with diamond tipped saws, using laser or electron beams, etc. Where a simple groove such as that shown in FIG. 2 is all that is necessary, sophisticated guidance mechanisms may not be necessary. For more intricate or elaborate cavity configurations, pantograph machines, or masking techniques may be necessary.
Referring next to FIG. 3, as the next step in the process, the flat, polished surface of ceramic body 20, which has been prepared as described with respect to FIG. 2 so as to have a desired cavity configuration, is placed in intimate contact with the flat, polished surface of ceramic body 22, which has been prepared as described with respect to FIG. 1. Typically, both body 20 and body 22 will be formed to have matching edges at the surface interface 24, and these edges will be aligned. The thus assembled part is placed on a firing tray and positioned in a furnace.
It is important to maintain the desired juxtapositioning of the bodies while they are in the furnace. One method for achieving this is to assure that the mating surfaces are flat with respect to one another on the order of two light bands, and then mating the surfaces together in such manner that air is forced out of the mating surfaces. The bodies will then remain in proper juxtaposition during later firing to maturing temperature. Another method of achieving this is to use a weight 26 equivalent to 50 grams per square centimeter of mating polished surface. These weights may be made of A12O3 or other non-reactive materials.
The part is then fired to the maturing temperature for the compound used in forming the part. In the case of yttrium iron garnet, the temperature is 1475 degrees centigrade. Detrimental effects to the material characteristics may occur due to vaporization if too long a firing time is used. To eliminate overfiring, the total firing time for the compound should not be exceeded. Thus, the time required for the initial firing to achieve optimum density and the time for firing to the maturing temperature should total the recommended firing time for the compound.
Referring to FIG. 4, the completed part is represented. The final processing steps involve machining the outer surfaces of the integrally formed ceramic body to the desired dimensions, and if multiple parts are to be obtained from the integrally formed ceramic body, slicing off the appropriate portion. Thus, as shown in FIG. 4, a ceramic toroid may be obtained.
The microstructure of the joined surfaces is shown in the photomicrograph of FIG. 5. A slight increase in the number of pores may be observed along the bonding plane as compared to the number of pores in the rest of the material. The quantity of pores is reduced as the surface finish and parallelism of the welding plane is improved. The more intimate the surface contact, the fewer pores are produced. The crystal size and shape at the interface are identical, confirming a bond produced by surface atoms melding together across the polished interfaces.
This formation of crystal structure across the interface is important not only for structural strength, but it also reduces discontinuities or pores which would interfere with the continuous arrangement of magnetic moments around the toroid, thereby producing higher remanent characteristics. Through the use of the present process, machining of the desired cavity configuration after firing of the ceramic mass has eliminated the pressing fluctuations by molecular transport (crystal growth) and has swept away the voids. The part has obtained a uniform density; and, if it is properly supported during subsequent firings, no further deformation or shrinkage will occur. The stabilization of this warpage and shrinkage contribute significantly to the dimensional stability of the resulting part.
Testing has proved that garnets, ferrites, and dielectrics (BaTi x O y ) are suitable ceramics that can be bonded according to the method of the invention. More specifically, it is contemplated that all garnets could be bonded according to the method of the invention. Cubic ferrites including all lithium ferrites and ferrites with substitution of aluminum, titanium, manganese, copper, and other metal ions should bond according the method of the invention, whereas cubic ferrites including nickel ferrites with aluminum substitution, nickel ferrites (unless zinc is added) and manganese magnesium ferrites should not. All hexagonal ferrites should be capable of being bonded by the method. Finally, dielectrics including magnesium titanates and silicates should be capable of being bonded, whereas aluminum oxides should not. The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of the method may be resorted to without departing from the spirit of the invention. | Unfired ceramic bodies which are to be joined together, are separately fired to the point of optimum density. The surfaces to be joined are machined to remove surface irregularities, lapped and polished. At least one of the two surfaces is machined to provide a desired cavity configuration. The polished surfaces are then juxtaposed and fired to the maturing temperature of the ceramic involved. A weight may be used to maintain the desired juxtapositioning. The outer surfaces of the now integral ceramic body are then machined to desired dimensions. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of Application Serial No. 847,344, filed Oct. 31, 1977 and now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to wheelchairs suitable for invalids or geriatric patients and is a continuation-in-part of my U.S. Patent Application No. 847,344 filed Oct. 31, 1977 and now abandoned.
Wheelchairs hitherto have had a number of disadvantages particularly as regards the comfort of the user when traversing uneven ground or ascending and descending curbs. The vertical movement of the side wheels in negotiating an uneven surface or a curb is transmitted to the seat and the occupant resulting in a bumpy and unpleasant ride unless compensated by complex expensive and bulky springing. It is also difficult to negotiate steps, curbs or depressions since when the wheels lift the chair over such steps, curbs or depressions, the chair and its occupant is lifted in one movement.
SUMMARY OF THE INVENTION
A wheelchair according to the invention comprises a castor frame assembly formed of forward and rearward castor frames pivotally connected one to the other about a transverse pivotal axis and each carrying at least one ground-engaging castor, a pair of independently rotatable ground-engaging wheels mounted one on each side of the castor frame assembly between the castors of the forward and rearward castor frames respectively, and a chair mounted on the forward castor frame rearwardly of the forward castor or castors and mounted on and pivotable relative to, the rearward castor frame forwardly of the rearward castor or castors.
The ground-engaging side wheels adjacent the sides of the chair preferably rotate about the transverse pivotal axis of the castor frame assembly and are preferably each provided with a conventional hand-wheel, of diameter slightly less than that of the ground-engaging wheels, to enable a user to propel the chair manually.
Because the chair is mounted straddling the front and rear castor frames, the weight of a user is distributed between the side wheels, the forward castor wheel or wheels and the rearward castor wheel or wheels. If the wheelchair travels over an uneven surface the forward and rearward castor wheels can rise or fall with accompanying pivoting of the forward and rearward castor frames. The mounting of the chair ensures that only a proportion of this movement is transmitted to the chair and occupant. Similarly when the side wheels rise or fall when riding over an obstacle, only a proportion of that vertical movement is transmitted to the chair and occupant. The result is a pleasant and comfortable ride without the need for complex expensive and bulky springing.
The positioning of the forward and rearward mountings of the chair dictates the ability of the wheelchair to negotiate steps, curbs or depressions in a satisfactory manner. It has been found suitable to mount the chair on the rear half of the forward castor frame and on the front half of the rearward castor frame. Not only does this provide for satisfactory negotiation of obstacles, but also enables the side wheels more easily to be placed in a position comfortable to the user and avoids excessive protrusion of the rear castor frame behind the chair where it could be a nuisance to a person pushing the chair.
Because the rear castor wheel or wheels exerts a stabilizing influence, the wheelchair is not prone to tipping backwards when travelling up steep slopes. Even if only one castor wheel is provided at the front and only one at the back, the wheelchair is particularly maneuverable.
The wheelchair may be folded for storage by removing the side wheels, collapsing the seat and pivoting the forward and rearward castor frames to lie one over the other. Preferably the mounting of the chair on both the forward and rearward castor frames is by means of pivotal linkages which do not have to be disconnected in order to fold the wheelchair, the chair structure in the folded condition of the wheelchair lying between the castor frames.
The seat and backrest are preferably rigid and shaped to suit medical requirements, but may be of canvas.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view of a wheelchair according to the invention, with only one side wheel shown for clarity;
FIG. 2 is a plan view from above of the wheelchair of FIG. 1 with the back support armrests and cross members removed;
FIG. 3 is an exploded view of the frame of the wheelchair shown in FIG. 1 with the seat shown in phantom and with the side wheels not shown for the sake of clarity;
FIG. 4 is a diagrammatic view of the chair approaching a step;
FIG. 5 is a similar view showing the chair with its front castor wheel having surmounted the step; and
FIG. 6 is a similar view showing the chair with its ground wheels having surmounted the step.
DESCRIPTION
The wheelchair shown in the drawings comprises a forward castor frame A carrying at its front end a castor wheel A' and pivoted at its rear end about a pair of stub axles M defining a central pivotal axis. A rearward castor frame B carries at its rear end a castor wheel B' and is pivoted at its front end about the stub axles M. Side wheels G are detachably secured to the stub axles M and are provided with hand wheels G' for movement of the wheelchair by an occupant. Pivot pins N mounted on the forward castor frame A provide a forward chair mounting by pivotally mounting front chair legs C. Each leg C is provided with an upward extension C' forming an armrest support member. Collars R rotatable on a transverse portion S of the rearward castor frame B provide a rearward chair mounting by supporting rear chair legs E. The top ends of each pair of legs C and E, at seat height, are connected by a longitudinal member H. The seat T is secured to the members H. The members H are pivotally mounted on the front chair legs C by means of pivot pins K and on the rear ends of rearward rigid extensions E' of the rear chair legs E by pivot pins J. The members H are releasably secured to the front ends of the rigid extensions E' of the rear chair legs E by locking pins F passing through the members H beneath the seat T.
The seat T has a back T' which can be folded flat against the base of the seat by pivoting on pins U. Armrests P are pivoted to the armrest support members C' and to the back of the seat T at pivot pins Q and Q'.
In the operational position of the wheelchair the rear chair legs E are rigidly secured to the longitudinal chair frame members H by means of locking pins F. The rear legs E and longitudinal membes H pivot together on collars R which are rotatable on the transverse portion S of rearward castor frame B. The pivot pins N and collars R respectively securing the lower ends of the forward and rearward chair legs C and E to the castor frames A and B are located to opposite sides of the stub axles M. The weight of an occupant of the wheelchair transmitted via legs C and E therefore urges castor wheels A' and B' downwardly and reinforces the inherent stability of the wheelchair. The pins N permit relative angular movement between the forward castor frame A and the front chair legs C. The pins K permit relative angular movement between the front legs C and the rear legs E. The collars R permit relative angular movement between the rear legs E and the rear castor frame B. In consequence, when relative angular movement between castor frames A and B takes place, this can be accommodated by pivotal movement between the chair legs C and E and the longitudinal seat member H. The armrests P and the seat back T' pivot about pins Q, Q' and U and offer no resistance to relative movement of the legs C and E and member H consequent on relative movement of the castor frames A and B'.
A footrest L is carried beneath the forward castor frame A by members Y and chains Z which are connected to the footrest L at Z'. For stowage, each member Y slides telescopically within an associated member C, permitting the footrest L to lie flush with the forward castor frame A. Rearmost portions of the footrest L are pivoted at Y' to the base of the members Y to enable the footrest to be lifted to a vertical condition beneath the front of the seat and parallel to the front legs C. A cutaway portion of the footrest L is provided to avoid interference with the forward castor frame A when the footrest is in the vertical condition.
In use, when the wheelchair rides over, for example, a curb, first the forward castor A' contacts the curb and rises. Some but not all of this lift is transferred to the chair and occupant due to the lifting of the forward chair mounting on the forward castor frame A. When the side wheels ride over the curb, which they are better able to do because of their larger diameter, the forward castor frame A resumes the horizontal condition and a part of the lift is again transferred to the chair and occupant. However, not until the rear castor B' rises over the curb is the final portion of the lift imparted to the chair and occupant. Analogous considerations apply when descending a curb.
The sequence of operations is clearly shown in FIGS. 4 to 6. As the wheelchair approaches the curb X, and the castor A' rides over it, the forward castor frame A pivots about the pin M while the rear castor frame B remains horizontal as shown in FIG. 5. The seat is raised during this first stage by reason of its support from the frame A. On further forward movement, the ground wheels G contact the curb X and ride over it, lifting the seat through a second stage. When the ground wheels G have surmounted the curb, the front castor frame A resumes its horizontal position while the rear castor frame B assumes an inclined position as shown in FIG. 6. Further forward movement of the wheelchair raises the rear castor wheel B' to surmount the curb, raising the seat through the third stage and returning the wheelchair to the position shown in FIG. 4.
To fold the wheelchair, each-cross member H is unlocked from its horizontal condition by releasing the locking pins F. The chair legs C and E, the cross members H and the seat T are then pivoted forwards until the legs E are inside and parallel to the corresponding sections of the rearward castor frame B. The folded combination of the frame B, the rear legs E and the cross member H is then lifted and rotated about the central axis M until the frame B lies over the frame A, with the chair assembly sandwiched between the frames A and B. The rear end of the frame A is in fact upturned to provide a space between the frames, in the folded condition, to accomodate the chair assembly.
Finally the two side wheels G are removed completely and the castors A' and B' are adjusted to lie flush with the framework. | A wheelchair suitable for invalids or geriatric patients has a chair or seat supported on independant forward and rearward castor frames pivotally connected together at a transverse axis to form a castor frame assembly. The chair is pivotally mounted on the forward and rearward castor frames so that in negotiating a step or other obstacle, the lifting movement of the occupant is divided into stages so that a pleasant or comfortable ride is obtained. The wheelchair may be folded into a collapsed condition with the chair itself located between the castor frames. | 0 |
BACKGROUND
[0001] The invention relates to a cryosurgical instrument and a method for separating a tissue sample from surrounding tissue of a biological tissue to be treated.
[0002] In cryosurgery, targeted controlled use of low temperatures are employed for devitalizing biological tissue. With flexible probes in particular, cryosurgery can be employed to remove foreign bodies from body cavities by freezing them solid to the cryoprobe or to a probe head, for example, foreign bodies which have been accidentally inhaled and must be removed from the respiratory tract. Cryosurgery is also suitable for collection of tissue samples (biopsy). In this context, a tissue sample can be frozen to the probe head and, after separation from the surrounding tissue, made accessible to an investigation.
[0003] There are various possibilities for deep-freezing in surgery; one is based on the Joule-Thomson effect: the atoms or molecules of an expanding gas below the inversion temperature counteract mutual attraction, such that the gas loses internal energy and cools. CO 2 or N 2 O is conventionally employed as the expanding gas. These gases are—referred to as working or coolant gases.
[0004] Cryosurgical instruments of the type just described conventionally have a probe which can be brought to the tissue to be treated, and gas conduits which pass through the probe and release working gas into the inner lumen of the probe, where the working gas expands and consequently cools the tips of the probe (the probe head). Since the probe head is generally produced from a thermally conductive material, conduction of the heat of the tissue via the probe head and cooling is consequently ensured.
[0005] Tissue samples are usually collected by conventional routes by means of forceps biopsy. However, the specimen obtained is very small and is usually squeezed during removal. Biopsy by means of cryosurgery makes it possible to collect tissue samples considerably more efficiently. For the purpose of a biopsy, the cryoprobe (rigid or flexible) is conventionally guided to the desired place, e.g., in a gastrointestinal tract, via a working channel of an endoscope (which may also be either rigid or flexible). The tip of the probe or probe head is positioned on the tissue to be treated, e.g. a mucous membrane, and a desired region of tissue (the tissue sample) freezes solid on the probe head due to the cooling mechanisms described above. The tissue sample thus adheres to the cooled probe head and the frozen tissue can be detached from the surrounding tissue by a pulling movement.
[0006] The detachment requires application of a relatively high force, which must be applied by the user. This presents numerous problems if the tissue to be treated also moves during the separation operation (that is to say during a pulling movement). For example, a high pulling force cannot be exerted on the large intestine (if a biopsy sample is to be obtained from that organ), since the large intestine floats free in the abdomen. The necessary pulling force can be applied here—if at all—only in pulses. Because of this, injuries may occur in the surrounding tissue (from too much force being applied), or a tissue sample cannot be removed at all because the surrounding tissue yields too much. Under such conditions, the frozen tissue sample can prematurely detach from the probe head.
[0007] The invention is therefore based on the object of developing a cryosurgical instrument that can reliably remove a tissue sample without damage to the tissue or to the patient. The object of the invention is furthermore to provide a method for separating a tissue sample from surrounding tissue of a biological tissue to be treated, which solves the problems described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention is described in the following with the aid of embodiment examples which are explained in more detail with the aid of the figures.
[0009] FIG. 1 shows an embodiment of the cryosurgical instrument according to the invention, the instrument being partly shown, in section;
[0010] FIG. 2 shows a section of the instrument according to the invention which is connected to a cryosurgery apparatus, with a diagram of gas conduits and the distal end of a probe with the probe head, in section;
[0011] FIG. 3 shows a section of the instrument according to the invention with a diagram of the fixing of a support means to a receiving means;
[0012] FIG. 4 shows the distal end of the probe, with a support means, guided in a working channel of an endoscope, in section;
[0013] FIG. 5 shows the probe head;
[0014] FIG. 6 shows a part of the gas delivery line with an aperture, in section;
[0015] FIG. 7A shows the distal end of the probe, this being positioned on a tissue to be treated;
[0016] FIG. 7B shows the distal end of the probe, a tissue sample having been removed.
SUMMARY OF THE INVENTION
[0017] An object of the present invention is achieved by a cryosurgical instrument which comprises a probe for guiding a probe head on to a biological tissue to be treated, and gas conduits for delivering coolant gas from a gas source to the probe head and for removing the coolant gas from the probe head, wherein the probe head is designed in such a way that, in order to collect a tissue sample, a limited region of the tissue can be cooled by means of the gas delivered and can be separated from the surrounding tissue in a state in which it is frozen on the probe head. The instrument has a support means in which the probe is guided and which can be moved relative to the probe in such a way that the surrounding tissue can be supported by means of the support means during separation of the tissue sample.
[0018] An important point of the invention lies in the fact that by means of the support means a counter bearing is created, which, during separation of the tissue sample from the surrounding tissue, supports the latter and holds it in position. The probe and support means can be further moved relative to one another in such a way that the support means comes to rest on the tissue surrounding the tissue sample, while the tissue (in principle the biopsy sample) is pulled on via the probe. In other words, the support means and probe can be moved relative to one another in such a way that either the probe head and, where appropriate, parts of a probe body of the probe can be released, or the support means can be moved beyond the probe head. By positioning the support means on the tissue, a force of the support means acts on the surrounding tissue and an equal and opposite pulling force acts by the pull on the frozen tissue via the probe (action and equal and opposite reaction) when the frozen tissue is removed from the surrounding tissue by means of the probe head. The support means thus exerts a counter-force on the tissue, while the tissue part frozen on the probe head is pulled on via the probe. The pulling force therefore acts only on a small area, and not on the entire surrounding tissue. The surrounding tissue can therefore be left essentially in its original position and is not adversely stressed.
[0019] In a preferred embodiment, the probe has a rigid or flexible shaft or catheter and can be guided through an instrument channel of a rigid or flexible endoscope to the tissue to be treated. In other words, the probe with the probe body and probe head is preferably designed for endoscopic interventions and can be guided in this manner to an operation region in a simple way.
[0020] The instrument preferably has a gripping means for handling the probe, a proximal end of the probe being mounted in the gripping means. The gripping means facilitates handling of the instrument.
[0021] The gas conduits preferably comprise a gas delivery line running through the probe, so that a hollow space inside the probe or probe body can be filled with gas for cooling the probe head. Since the probe head must be cooled by means of the working gas or coolant gas, the gas conduits are designed in such a way that the coolant gas can be brought into contact with the probe head. For this, for example, a hollow space which can be filled with the coolant gas is arranged in the immediate vicinity of the probe head. The gas thus flows through the gas delivery line within the probe in the direction of the probe head into the hollow space and during this cools (e.g. due to the expansion, as described above) the probe head. The gas delivery line is preferably arranged in such a way that it lies within a gas removal line of the gas conduits which is likewise arranged in the probe, the gas removal line preferably being designed in such a way that it includes the hollow space.
[0022] The gas conduits not only comprise the line sections (gas delivery line, gas removal line) within the probe, but in one embodiment lead via the gripping means through a tube means. The tube means can then be connected to the cryosurgical apparatus via a further extension of the gas conduits or directly. The cryosurgical instrument therefore preferably includes the probe with the gripping means and the tube means for connection to the cryosurgical apparatus.
[0023] Cryosurgery apparatuses are envisaged for the most diverse intended uses and operate, for example, by the abovementioned Joule-Thomson effect. It would also be possible to perform cryosurgical interventions by means of liquid nitrogen.
[0024] Preferably, the support means is designed in such a way that it encloses the probe in the form of a tube or hose. In other words, the support means is designed as a hose or a tube into which the probe is inserted. The support tube is therefore provided here as an outer probe body. The support means and probe are arranged relative to one another in such a way that they can be moved relative to one another or also against one another. By the moving relative to one another, the probe head can be moved beyond an end of the support means close to the probe head (distal end) and is therefore exposed (so that the probe head can reach the tissue for removal of the tissue sample). Conversely, the support tube can be pushed beyond the probe head and the probe head can be received completely in the support tube (with the tissue sample). The support tube can therefore be pushed against the tissue from which the tissue sample is to be taken to support this after the tissue sample has been deposited on the probe head due to freezing.
[0025] In one embodiment, a receiving means for receiving a proximal end of the support means is provided, the receiving means and the gripping means being connected to one another and displaceable with respect to one another by means of a coupling unit. This makes it possible for the probe and support means to be moved relative to one another by the receiving means and gripping means being moved relative to one another. The receiving means and gripping means (and therefore support means and probe) can be displaced relative to one another over a defined path length, it being possible for the path length to be determined, e.g., via correspondingly cooperating stops between the receiving means and gripping means, in other words, in the coupling unit.
[0026] As already explained above, the probe is preferably guided in the support means. The probe and support means are therefore arranged, e.g., coaxially with respect to one another, the support means enclosing the probe only up to the receiving means, while the probe can run further through the receiving means into the gripping means.
[0027] Preferably, the coupling unit is designed in such a way that a pushing means of the receiving means and a channel region of the gripping means interlock at least in part regions, so that the support means and the probe can be moved relative to one another, by means of a pushing or pulling movement of the gripping means and/or receiving means, along a direction of extension of the probe over the defined path length in such a way that at least the probe head can be received in the support means or can be released from this. The tubular (or other shaped) pushing means is therefore guided with one end in the channel region of the gripping means, so that the pushing means and the gripping means can be moved away from one another and towards one another. In other words, a relative movement between the probe and support means takes place in such a way that the probe fixed to the gripping means (at least with a distal end) can be moved out of the support means fixed to the gripping means, and conversely the support means can be pushed over the probe head to such a distance that it holds back the surrounding tissue while the tissue sample is separated. The pushing means here is preferably tubular in design, so that the probe or probe body can be guided further to the gripping means or into this.
[0028] Depending on the dimensions of the support means and working channel of the endoscope, the support means can be arranged in a fixed manner (in principle the support means is clamped) in the working channel in such a way that relative movement between the support means and working channel is possible only with difficulty. In this case the probe would then essentially be moved via the gripping means and pushed in the support tube. The aim can also be to move the support means via the pushing means. In any case, the arrangement is envisioned in such a way that it is a matter of the relative movement between the probe on the gripping means and the support means on the receiving means, it also being possible for the probe and support means both to be movable relative to one another; it must be possible to push the support means beyond the probe head or to receive the probe head in the support means to such a distance during separation of the tissue sample that the tissue can be supported and separation can be carried out. Displaceable mounting of the receiving means in the gripping means makes relative movement possible.
[0029] The support means is preferably designed in such a way that the tissue region (the tissue sample) frozen on to the probe head can be received in the support means with the probe head. In other words, in order to be able to receive the biopsy sample in the lumen of the support means (the support tube), the support means must have a sufficiently large lumen. Needless to say, the support means including the probe is to be designed in such a way that it can be inserted without problems in a working channel of an endoscope. The possibility of being able to receive the tissue sample in the support means facilitates recovery of the biopsy sample. The probe can be pulled out of the working channel, the biopsy sample safely contained in the lumen of the support means.
[0030] If the support means is designed as a tube, the tissue can be contacted at the distal end of the support means via an opening of the positioning edge enclosing the support means. This positioning edge is preferably blunt in design so that it does not cut into the tissue. Needless to say, when designing the positioning edge it must be ensured that this can be guided through the working channel of the endoscope. Furthermore, a material which can undergo elastic deformation up to a certain degree can be used for the support means. Injury to the surrounding tissue can also be avoided by this means.
[0031] The probe head, which is preferably constructed from metal (e.g., high-grade steel), is connected to a probe which is preferably constructed from plastic. A polyether ketone (PEK) or polyether ether ketone (PEEK), is envisaged, for example, as the probe material (material for the probe body). PEEK has a high strength, a good resistance to chemicals and a very good heat resistance. The support means is preferably constructed from perfluoro-(ethylene-propylene) plastic (FEP), polytetrafluoroethylene (PTFE) or a plastic of the like.
[0032] The method object is achieved in that in a method for separating a tissue sample from surrounding tissue of a biological tissue to be treated, using a cryosurgical instrument which comprises a probe with a probe head and gas conduits for coolant gas from a gas source of a cryosurgical apparatus with a gas delivery line and gas removal line each running through the probe, to the probe head and away from this, and a support means in which the probe is guided and which can be moved relative to the probe, the following steps are envisioned:
guiding the probe to the tissue to be treated, preferably via a working channel of an endoscope, positioning the probe head on the tissue to be treated, delivering coolant gas to cool the probe head, so that, in order to collect the tissue sample, a limited region of the tissue is cooled and freezes on to the probe head, moving the support means and probe relative to one another in such a way that the tissue sample is separated and the surrounding tissue is supported by means of the support means during separation of the tissue sample, and recovering the tissue sample.
[0038] By means of this method, a tissue sample can be removed reliably and with a high degree of safety for the patient, since the support means also holds the tissue from which the tissue sample is to be taken in the corresponding position when a pulling force (for separating the tissue sample) acts on the tissue. As soon as the probe with the support means is guided to the tissue to be treated and the probe head has been positioned on the tissue, the probe head is cooled accordingly, so that the tissue sample is frozen and deposited on the probe head. An activation time of, for example, at most two seconds for the cooling means, avoids undesirable freezing-on also of the positioned support means, or a resulting biopsy sample which would be too large to be able to be received in the support means.
[0039] As already mentioned above, the probe and support means can be displaced relative to one another. By displacing the elements relative to one another, the support means is pressed against the tissue to be treated. Preferably, the support means is designed in such a way that the tissue sample is dragged into the lumen of the support means at the same time as the probe head. The tissue sample is separated from the surrounding tissue (the sample tears off). This happens very much more gently than in conventional methods, since the pulling force necessary for separating the tissue sample and the force acting on tissue due to the support means oppose each other.
[0040] As soon as the tissue sample has been separated from the surrounding tissue and received in the support means, the tissue sample can be recovered. In other words, the tissue sample, safely contained in the support means, can be pulled out of the working channel by means of the cryosurgical instrument.
[0041] Preferred embodiments of the invention emerge from the subclaims.
DETAILED DESCRIPTION OF THE INVENTION
[0042] In the following description, the same reference numbers are used for the same parts and parts which have the same action.
[0043] FIG. 1 shows an embodiment of the cryosurgical instrument 10 according to the invention. With this instrument for biopsy, tissue samples of biological tissue can be collected in a simple manner. The instrument 10 is designed in such a way that it can be employed in endoscopy. The instrument has a gripping means 20 , a probe 40 , preferably for insertion into a working channel of an endoscope (not shown here), being provided at a distal end 22 of the gripping device. For this, the probe 40 is rigid or flexible in design and can be used with the corresponding endoscopes. The instrument 10 can in principle also be designed in such a way that it can be used without an endoscope, In other words, directly.
[0044] The probe 40 has, in addition to a probe body 43 , a probe head 42 at a distal end 41 and is sheathed by a tube (or also hose) designed as a support means 60 . The support means 60 is fixed to a receiving means 64 , the receiving means 64 being mounted such that it is displaceable with respect to the gripping means 20 . The receiving means 64 is arranged on the distal end 22 of the gripping means 20 in such a way that an operator can displace the gripping means 20 and the receiving means 64 relative to one another without problems, in order finally to displace the probe 40 and support means 60 against one another, In other words, relative to one another. The probe 40 passes through the receiving means 64 and is guided in the gripping means 20 and coupled there.
[0045] At a proximal end 21 of the gripping means 20 a hose 30 is attached, which in turn has a connection means 31 at a proximal end (in principle the proximal end of the instrument). In the state shown, this is covered by a blind plug 33 . After removal of the blind plug 33 , the instrument 10 can be connected to a cryosurgical apparatus 80 and to a gas source via a knurled nut 32 . At least one gas delivery line 50 (shown in FIG. 2 ) and at least one gas removal line 52 (shown in FIG. 2 ) are arranged in the hose 30 , so that on the one hand the probe 40 can be supplied with coolant gas or working gas and on the other hand the gas can be removed from this again. The hose 30 itself can also serve as the gas removal line 52 . The gas lines pass through the hose 30 and are guided via the gripping means 20 and the probe 40 up to the probe head 42 . For this, a coupling means (not shown) mounted in the gripping means 20 is provided, in order to connect the probe 40 to the gas lines coming out of the hose 30 .
[0046] The cryosurgical instrument 10 is preferably guided via the endoscope to the tissue to be treated, from which a biopsy sample is to be collected, and in particular in such a way that the probe head 42 touches the tissue. By delivery of the coolant gas to the probe head 42 or at least in the vicinity thereof, this can be cooled in such a way that a region of the tissue freezes on to this. The probe head 42 is therefore constructed from thermally conductive material, preferably from metal, in order to make freezing on of the tissue possible. The Joule-Thomson effect is utilized for cooling the probe head, i.e. cooling of a real gas under throttled expansion. The gas is therefore only used for cooling the probe head and does not come into contact with the tissue. The tissue frozen on can now be separated from surrounding regions of tissue. The support means 60 facilitates this separation operation. Conventionally, the tissue frozen on to the probe head 42 would have had to be torn off from the remaining tissue by jerking, for example by pulling the probe 40 back from the tissue by jerking. Application of a high force is therefore required when detaching the frozen specimen, e.g. a mucous membrane. This presents problems if the tissue to be treated also moves during the separation operation (during a pulling movement). In this case a high pulling force cannot be exerted on, for example, a large intestine (if a biopsy sample is to be obtained from this), since the large intestine floats free in the abdomen.
[0047] To counteract these problems, the cryosurgical instrument 10 according to the invention has the abovementioned support means 60 . This is designed such that it acts or can be utilized as a counter bearing during separation of the biopsy specimen from the surrounding tissue. The instrument 10 is designed in principle such that after freezing of the tissue on to the probe head 42 , the support tube 60 can be moved, by the cooperation of the gripping means 20 and receiving means 64 , relative to the probe 40 in the distal direction, In other words, in the direction of the tissue, in such a way until it lies or is positioned on the tissue (surrounding the actual biopsy specimen). By the movement of the probe 40 and support means 60 or support tube relative to one another, the probe head 42 can be received in the support means 60 , so that the biopsy specimen is thereby separated from the surrounding tissue. In other words, the probe head 42 must have dimensions such that the support means 60 can be pushed over this. Only in this way can separation of the tissue sample be effected by the pulling movement on the tissue. By positioning a distal end 62 of the support tube 60 with the edge (positioning edge) 63 enclosing the opening of the tube on the tissue, the force of the support tube (In other words, the support means) 60 acts on the tissue surrounding the biopsy sample and is equal and opposite to the pulling force for separating the frozen tissue (action and equal and opposite reaction). The pulling force on the tissue for “tearing off” the tissue sample is now moderated by the support means on the tissue surrounding the tissue sample. The surrounding tissue can therefore be left essentially in its original position and is not adversely stressed. In all cases the probe 40 and support means 60 can therefore be moved relative to one another in such a way that the surrounding tissue can be supported by means of the support means 60 during separation of the tissue sample, the tissue sample frozen on to the probe head being received into the support tube.
[0048] Since the support means 60 simultaneously serves as a means for recovering the biopsy specimen, the tissue sample received in the support means can be removed from the working channel 90 under protection with the probe 40 .
[0049] As shown further in FIG. 1 , the receiving means 64 comprises a holding means 65 in which the support means 60 is received (e.g. clamped or screwed) with a proximal end 61 . In this embodiment example the support means 60 therefore encloses the probe 40 only up to the receiving means 64 , while the probe 40 is guided further in the gripping means 20 without this casing. The receiving means 64 furthermore comprises a pushing means 66 , to which the holding means 65 is connected, e.g. screwed or clamped. The pushing means 66 is guided in the gripping means 20 in a channel region 23 of the gripping means 20 , so that the probe 40 and support means 60 can be moved relative to one another in the direction E, that of the extension of the probe, as already described above. The pushing means 66 and channel region 23 form a coupling unit 70 . The pushing means 66 abuts, for example, with corresponding regions on stops formed by the gripping means 20 , in order to limit or to define the displacement path of the pushing means 66 in this way and to retain the pushing means 66 in the gripping means 20 or in the channel region 23 . The elements for mounting the probe in the gripping means can also form path-limiting stops. In this embodiment example, the pushing means 66 is designed in a tubular form with a channel in such a way that the probe 40 can be guided through the pushing means 66 .
[0050] In this embodiment example, the pushing means is received in the channel region of the gripping means with an end facing the gripping means, while the opposite end of the pushing means projects out of the gripping means. The gripping means and the pushing means can therefore be grasped by an operator and the two elements can be moved relative to one another, In other words, moved towards one another or away from one another.
[0051] The proximal region 61 of the support means 60 can additionally be surrounded by a further hose element (not shown) as protection from kinking, so that the probe with the support means is extremely stable in design in the region of the gripping means and cannot be kinked during use.
[0052] FIG. 2 shows a section of the instrument according to the invention which is connected to the cryosurgery apparatus 80 , diagrams of the gas conduits 50 , 52 in part and the distal end 41 of the probe 40 with the probe body 43 and probe 42 being shown in section. Via the gas source (not shown) connected to the cryosurgery apparatus 80 , the working gas for cooling the probe head 42 is led through the gas delivery lines 50 to the probe head 42 . The distal end 41 of the probe 40 comprises the probe head 42 . The gas lines reach to the probe head 42 . In this embodiment example, the gas delivery line 50 of the probe 40 is arranged within the gas removal line 52 , the gas removal line 52 having a larger diameter than the gas delivery line 50 for this purpose. The gas delivery line 50 has an aperture 51 at its end close to the probe head, via which the gas enters into a hollow space 53 formed directly adjacent to the probe head 42 .
[0053] In principle, this hollow space 53 is an end of the gas removal line 52 close to the probe head. The gas is expanded here through the aperture 51 and can then cool the probe head 42 , which is preferably constructed from metal (e.g. high-grade steel). By the expansion of the gas, the Joule-Thomson effect causes cooling of the probe head 42 . In this context, the gas, which is under high pressure, cools severely on passage through a narrow nozzle (here the aperture), so that the cryoprobe tip (probe head) cools, and freezes the adjacent tissue. Thereafter, the gas can be removed from the hollow space 53 again and therefore from the probe 40 via the gas removal line 52 . The gas delivery line 50 mounted eccentrically here could also be arranged, for example, coaxially with the gas removal line 52 .
[0054] Such cryosurgery apparatuses are envisioned as having diverse possible uses, as shown here operating, for example, by the abovementioned Joule-Thomson effect. Cryosurgical interventions can also be performed by means of liquid nitrogen.
[0055] FIG. 3 shows the probe 40 with support means 60 , the proximal end 61 of the support means 60 being fixed in the holding means 65 , shown in section, of the receiving means 64 . The support means 60 is fixed in the holding means 65 in such a way that the two means cannot be moved relative to one another. Needless to say, the clamping or fixing of the support means 60 in the receiving means 64 should not impede the possibility of moving the probe 40 and support means 60 relative to one another.
[0056] FIG. 4 shows the distal end 41 of the probe 40 in section, the support means 60 or here the support tube being pushed over the probe head 42 . The support tube 60 is therefore guided in a manner enclosing the probe 40 , so that at least the probe head 42 can be received in the support tube 40 and can be released from this again. The working channel 90 of an endoscope in which the probe 40 with the support means 60 is inserted is furthermore shown.
[0057] The probe head is preferably—as already explained above—constructed from metal. The probe itself, i.e. the probe body, is preferably constructed from a polyether ketone (PEK), preferably from a polyether ether ketone (PEEK) or plastic of the like. The support means is also preferably constructed from a plastic, e.g. from perfluoro-(ethylene-propylene) plastic (FEP), from polytetrafluoroethylene (PTFE) or a plastic of the like.
[0058] In FIG. 5 , the probe head 42 is shown by itself, such as it can then be received in the probe body. It is essentially spherical in design here, and has a roughened surface. A roughened surface has the effect of increasing the surface area, so that deposition (better adhesion) of the tissue on to the probe head 42 is assisted due to the structure. This prevents the biopsy sample from being lost during recovery. The probe head can also have a coating (which, for example, facilitates deposition of the tissue). A polished configuration of the probe head is of course also possible. The spherical form simplifies collection of samples when the cryoprobe is applied laterally to the tissue to be treated.
[0059] The probe head here is provided with a type of carrier element integrally with the latter, in order to position the probe via the carrier element and to fix the probe head in this way. The carrier element has an elongated hole at one end, to which the gas delivery line 50 is fixed, e.g. welded, to release tension. The gas delivery line is thus fixed around the periphery of the elongated hole e.g. by laser welding.
[0060] FIG. 6 shows the aperture 51 constructed on the end of the gas delivery line close to the probe head. On passage through the hole region, expansion of the gas takes place in such a way that it is cooled and cooling of the probe head 42 therefore takes place.
[0061] FIG. 7A and 7B show the removal of the tissue sample 101 from the tissue 100 to be treated. Only the probe end with the probe head 42 and support tube 60 are shown here. The endoscope is not shown. In FIG. 7A , the probe head projects out of the support tube (the support means) and is positioned on the tissue 100 to be treated. As soon as a region of the tissue has frozen on the probe head, this region, which finally forms the tissue sample 101 , can be separated from the surrounding tissue 100 by moving the probe 40 and support means 60 relative to one another (via the gripping means and pushing means) and dragged into the support tube 60 —as shown in FIG. 7 B—while at the same time the support tube 60 is positioned on the tissue 100 which surrounds or surrounded the tissue sample 101 and holds back against the pulling force by the probe 40 . The arrows indicate any possible directions of movement A, B of the probe 40 and/or support tube 60 , respectively, relative to the direction E—the direction in which the probe is extended.
[0062] Finally, it is to be noted that it is an essential point of the invention to provide in the cryosurgical instrument a means which supports a tissue, from which a tissue sample is to be removed, in such a way that a pulling force on the surrounding tissue necessary for the removal of the tissue sample is moderated. This is advantageous in particular if the tissue to be treated is suspended in the patient's body in a movable manner and/or is elastic in such a way that it would follow the pulling movement. | The invention relates to a cryosurgical instrument and a method for separating a tissue sample from surrounding tissue of a biological tissue that is to be treated. The cryosurgical instrument comprises a probe for guiding a probe head on to a biological tissue to be treated, and gas conduits for delivering coolant gas, wherein the probe head is designed in such a way that, in order to collect a tissue sample, a limited region of the tissue can be cooled by means of the gas delivered and can be separated from the surrounding tissue in a state in which it is frozen on the probe head. The instrument is intended to permit reliable removal of a tissue sample without damaging the tissue and to ensure a high degree of safety for the patient. To this end, the instrument has a support means in which the probe is guided and which can be moved relative to the probe in such a way that the surrounding tissue can be counter-supported during separation of the tissue sample. The corresponding method carried out by means of the cryosurgical instrument involves separation of a tissue sample from surrounding tissue of a biological tissue to be treated. | 0 |
This application is a continuation-in-part of application Ser. No. 139,587, filed Dec. 30, 1983 now abandoned, which is a continuation-in-part of application Ser. No. 866,913, filed May 27, 1986 now U.S. Pat. No. 4,732,944, which is a division of application Ser. No. 642,042, filed Aug. 17, 1984, now U.S. Pat. No. 4,619,973.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to ionomer resins, to transparent ionomer resin films, and in particular relates to individual sheets of ionomer resin films and ionomer resin films for use in laminates, including laminated glass, and further relates to ionomer resins which are neutralized with polyamines to produce thicker, stronger transparent films.
2. Description of Prior Art
Safety glass can be reinforced by lamination with an inner layer of polycarbonate. The resulting lamination, however, is impractical for two principal reasons. One reason is insufficient bond strength when the polycarbonate is bonded directly to the glass. A second, and even more important reason stems from polycarbonate and glass having different co-efficients of thermal expansion. In safety glass laminates wherein polycarbonate is bonded directly to glass, the polycarbonate can crack and craze on cooling from the temperature necessary to bond the two together, because of the different thermal expansion co-efficients of the components.
Initial attempts to solve these problems involved interposing additional interlayers of polyvinyl butyral between the polycarbonate and the glass. Adhesion between the polycarbonate and the glass proved insufficient unless a plasticizer was also used. However, when a plasticizer was used, the plasticizer often caused the polycarbonate to develop stress cracks, and accordingly, to have low light transmission properties.
The initial problems appear to have been solved by using the laminated safety glass described in U.S. Pat. No. 3,888,032, which has achieved wide commercial success. The laminate comprises polycarbonate reinforced glass wherein the polycarbonate and glass are bonded to one another by an interlayer of polyurethane. Polyurethane provides sufficient adhesion to glass and to the polycarbonate, and no stress cracking or cloudiness develops in the product.
Despite the commercial success of polyurethane laminated product, there has been a continuing effort to develop less expensive products, particularly as polyurethane is an expensive component. This invention provides new glass laminates, with and without layers of polycarbonates, and other reinforcing transparent plastics, which are considerably less expensive than the polyurethane laminates, yet which at the same time are every bit as satisfactory, if not more so, with regard to adhesion, strength and clarity. Laminates according to this invention comprise at least one layer of glass laminated with an ionomer resin film.
In the specification and claims the term "ionomer" or "ionomer resin" mean an extrudable resin comprising ionically crosslinked ethylene-methacrylic acid and ethylene-acrylic acid copolymers. Properties which distinguish these ionomer resins from other polyolefin heat-seal polymers are high clarity, tear resistance, abrasion resistance, solid-state toughness and resistance to oil-fat permeation. The starting ionomer resins are generally partially neutralized with one or more cations. Preferably the cations are selected from the group consisting of alkali metals, aluminum, ammonium salt and zinc. Advantageously, the cation is sodium alone or together with zinc. However, as will be discussed hereafter, the esters or the non-neutralized form of the resin are also adaptable to the present invention.
Various grades of ionomer resins are available for extrusion coating and film extrusion. It is also known that ionomer resins can be co-extruded with other plastic resins and exhibit adhesion to other polyolefins, nylon resins and coextrudable adhesive resins often used as bonding layers in multi-ply coextruded structures. A very wide variety of partially neutralized ionomer resins are manufactured by E.I. DuPont de Nemours and Company under the registered trademark "SURLYN".
Ionomer resins have been suggested for use primarily in the area of packaging, for foods, liquids and pharmaceuticals, as well as certain industrial applications including lightweight sails, bonded cable sheath, roof underlayments and flame retardant products. In most applications, ionomer resins are offered as a superior substitute for polyethylene. Moreover, it has been generally assumed that ionomer resin films thicker than 10 mil cannot be obtained while still maintaining optical clarity of at least 60% light transmission.
Layers of ionomer resins can be formed by casting, forming blown film or extrusion, the latter being preferred. Once formed, there are no significant differences between cast, blown and extruded layers. When the ionomer resin layer is sufficiently thick, polycarbonate layers can be eliminated altogether in forming layered materials, and if the ionomer layer can be made sufficiently thick without interfering with optical clarity, an unsupported film can be provided.
Ionomer resins have several advantages over polyurethane. Polyurethane is difficult to manufacture, is expensive and is hard to fabricate. Also, polyurethane is frequently not clear enough for use in windshields and the like. By contrast, ionomer resin films can be easily extruded to desired thicknesses, and at about one-half the material cost of polyurethane. Ionomer resins have demonstrated better adhesion characteristics to glass and polycarbonates, as well as better resistance to lower temperatures. In preferred embodiments, the surface to which the ionomer resin is bonded may be primed to get good adhesion, as is the case with polyurethane. Silane coupling agents are suitable primers. With regard to optical properties, ionomer resins demonstrate better clarity than polyurethanes when prepared according to the invention.
When films of the ionomers of copolymers of ethylenemethacrylic acid or ethlyene-acrylic acid have previously been formed, they usually only retain their clarity when formed in very thin films. The clarity of the films is insured because the ionomers can be cooled quickly after being melted. Rapid cooling prevents finely dispersed crystalites from being formed and, thereby, creating a hazy film. These crystalites lower the light transmission of the film and give lower clarity to the film. In thicker films and sheets of the ionomer, the degree of clarity becomes an important problem since a larger mass of the film cools much more slowly and allows the crystalites a greater opportunity to form and grow. In fact, clear sheets of 20 mils or thicker are not obtained with clarity under normal cooling conditions. Rapid quenching of the thick layers can help, but rapid quenching becomes impossible or at least very difficult if the ionomer sheet is laminated or is a part of a larger object. When transparent windshields are to be made from ionomer films, some means is required in order to prevent the crystalites from forming and creating the resulting haze in the film during processing and cooling.
The present invention primarily concerns development of diamine neutralized carboxylic acid-containing hydrocarbon polymers which can be formed into transparent sheets or films which are substantially thicker than previously thought obtainable.
U.S. Pat. No. 3,471,460 to Rees also teaches diaminemodified acrylic or methacrylic acid hydrocarbon copolymers, and in the discussion thereof indicates that diamines may also be used as modifying or neutralizing materials. The present invention, however, provides a group of diamines which are an improvement over that patent in that only primary diamines and polyamines are preferred. The Rees patent includes many diamines, but does not include: ##STR1## wherein R 1 , R 2 and R 3 are each alkyl groups of 1-4 carbon atoms, and M is CR, nitrogen, phenyl and cycloalkyl having 5-8 carbon atoms, wherein R is hydrogen, alkyl of 1-4 carbon atoms, lower alkyl amine, or cycloalkyl of 5 to 8 carbon atoms.
The present invention preferably excludes all diamines or polyamines that are not primary or aryl groups.
The present invention also excludes aromatic primary amines, i.e. ##STR2## and focuses on diamines and polyamines that have one or more (H 2 N--CH 2 --) groups per molecule.
The amine groups in --CH 2 NH 2 structure should form the strongest interaction with free carboxyl groups in the ethylene methacrylic acid or ethylene-acrylic acid copolymers or in the acrylic acid homopolymers. Therefore, the selected group of diamines which includes BAC, 1,6 hexane diamine and 1,12 dodecanediamine, form the strongest amine salt or ionomer bonds. These diamines form stable ionic bonds at the highest temperatures of all the amines, at which point these polymers will be in their most disordered and non-crystalline state. By forming strong amine salt bonds these diamines cross-link these polymers and fix them in their least crystalline form. Upon cooling these polymers become "frozen" in their non-crystalline form and remain optically clear. The broader general groups of amines that Rees described include mostly amines that will not produce significant optical clarity in the resulting neutralized polymer. The selected groups of diamines of the present invention form strong diamine ionomer bonds and the resulting polymers are tougher, stronger, and have greater optical clarity on the average than the groups of diamines which Rees teaches.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an ionomer resin which is a polyamine neutralized carboxylic acid containing hydrocarbon polymer
It is an object of this invention to provide a laminated article of glass and ionomer resins, and depending upon application, laminates of glass, ionomer resin and polycarbonate or other high impact transparent plastics as well. The laminated articles have all of the advantages and positive features of laminates of glass and polyurethane, but are significantly less expensive to produce and have other enhanced features such as increased clarity and more stable to delamination.
It is another object of this invention to provide a laminated article of glass, ionomer resin and high impact plastic which has good adhesion and which is transparent and resistant to breakage.
It is still another object of this invention to provide a laminated article of glass, ionomer resin and high impact plastic which has good strength properties over a wide temperature range.
And still further, it is an object of this invention to provide an ionomer film of thicker dimensions than previously possible without hazing or disruption of the clarity of light transmission through the film.
These and other objects of this invention are accomplished by providing an ionomer resin film which can be laminated to a sheet of glass, high plastic plastic such as acrylic, or which can be used alone in thicknesses greater than 50 mils. The preferable ionomer resin film is an ionically crosslinked ethylene-methacrylic acid copolymer further crosslinked with a polyamine. The laminated articles may also comprise a sheet of plastic laminated to the ionomer resin film opposite the glass or plastic ionomer laminates themselves. The laminated articles may further comprise the ionomer resin film sandwiched between two sheets of glass. The laminated articles may still further comprise a sheet of ionomer-resin film sandwiched between sheets of the plastics. The laminated articles may still further comprise the ionomer resin film sandwiched between a sheet of glass and a sheet of plastic, and the ionomer resin film sandwiched between a sheet of glass and a sheet of metal. The laminated articles may also comprise any number of lamina of glass sandwiched with a lamina of ionomer resin, the resultant laminate having glass as the outer lamina. Further, the multi-layer laminate of glass and ionomer resin may have a glass/ionomer configuration, with glass as the outer layer and ionomer resin as the interior layer, the interior ionomer resin layer having further a polyester film layer laminated thereto on the side opposite the glass layer.
In fulfillment of further objects of this invention, the ionomer resin composition used in the laminate, or by itself, may be prepared by combining a copolymer of ethylene-methacrylic acid or ethylene-acrylic acid and a polyamine which contains at least two --CH 2 --NH 2 groups.
Still further, the ionomer resin may also be prepared by combining a partially neutralized copolymer of ethylenemethacrylic acid or ethylene-acrylic acid and polyamine as described above.
BRIEF DESCRIPTION OF THE DRAWING
The Figures illustrate cross-section views through portions of laminated articles made in accordance with this invention, wherein:
FIG. 1 is a glass/ionomer resin laminate;
FIG. 2 is a glass/ionomer resin laminate having a hard coat on the otherwise exposed surface of the ionomer resin layer;
FIG. 3 is a glass/ionomer resin/plastic laminate;
FIG. 4 is a glass/ionomer resin/plastic laminate having a hard coat on the otherwise exposed surface of the plastic layer;
FIG. 5 is a glass/ionomer resin/glass laminate;
FIG. 6 is a glass/ionomer resin/plastic/ionomer resin/glass laminate;
FIG. 7 is a glass/ionomer resin/metal laminate;
FIG. 8 is a glass/ionomer resin/glass/ionomer resin/glass/ionomer resin/glass laminate;
FIG. 9 is an ionomer resin/plastic laminate;
FIG. 10 is a plastic/ionomer resin/hardcoat laminate;
FIG. 11 is an plastic/ionomer resin/plastic laminate;
FIG. 12 is an individual ionomer resin layer having a thickness greater than 50 mils; and,
FIG. 13 is a glass/ionomer resin/glass/ionomer resin/polyester film laminate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The basic laminated article according to this invention is shown in FIG. 1. The laminated article 10 comprises a sheet of glass 12 laminated to an ionomer resin layer 14. The ionomer resin layer 14 is thicker in the basic laminated article than in articles including a layer of high impact plastic or a second layer of glass.
A second embodiment of a laminated article according to this invention is shown in FIG. 2. The laminate 20 comprises a sheet of glass 22 and an ionomer resin layer 24, similar to the laminate 10 of FIG. 1. However, the embodiment of FIG. 2 is further provided with a hard coat 26 on the otherwise exposed surface of the ionomer resin film, in order to enhance the ionomer resin film from scratching, abrasion and other similar damage. A "hard coat" provides abrasion resistant, optically transparent coatings which serve to protect the surface and render the laminate more resistant to scratching and the like. Useful "hard coat" compositions are described in U.S. Letters Patent No. 4,027,073, and U.S. patent application Ser. No. 473,790, filed Mar. 10, 1983, now abandoned and assigned to the owner of this application.
A third embodiment of a laminated article according to this invention is shown in FIG. 3. The laminate 30 comprises a sheet of glass 32 laminated to an ionomer resin film 34, which is in turn laminated to a high impact transparent plastic layer 36. As additional strength is provided by the plastic layer 36, the ionomer resin layer 34 may be thinner than the ionomer resin layer 14 in the embodiment shown in FIG. 1. Examples of high impact, transparent plastic useful in this invention include polycarbonate and acrylic plastic, i.e. polymethylmethacrylate (PMMA), and such commercial plastics as the registered trademark materials LUCITE and PLEXIGLASS.
A fourth embodiment of a laminated article according to this invention is shown in FIG. 4. The laminate 40 is similar to that of FIG. 3, in comprising a glass sheet 42, an ionomer resin layer 44 and a high impact plastic layer 46. Although the plastic is used to provide additional strength to the laminate, some plastics, like polycarbonate, are usually too soft and susceptible to solvents, and therefore subject to scratches and abrasion. Accordingly, the laminate 40 is provided with a hard coat layer 48 for protecting the otherwise exposed surface of the plastic layer 46.
A fifth embodiment of a laminated article according to this invention is shown in FIG. 5. The laminate 50 comprises two sheets of glass 52, 54 joined by an ionomer resin layer 56. As no soft surfaces are exposed, no hard coat layer is necessary.
A sixth embodiment of a laminated article according to this invention is shown in FIG. 6. The laminate 60 comprises first a plastic layer 62 sandwiched between two ionomer resin layers 64, 66. The ionomer resin/plastic/ionomer resin laminate is itself sandwiched between two glass sheets 68 and 70. As might be expected, the thicker and more complex laminate 60 shown in FIG. 6 is more expensive to produce than the laminates shown in FIGS. 1-5, but it exhibits greater strength and resistance to shattering and spalling.
A seventh embodiment of a laminated article according to this invention is shown in FIG. 7. The laminated article 70 comprises a sheet of glass 72 and a sheet of metal 76 joined by an ionomer resin film layer 74. The metal layer 76 may be any metal such as aluminum, silver, iron and copper.
An eighth embodiment of a laminated article according to this invention is shown in FIG. 8. The laminated article 80 comprises sheets of glass 82, 86, 87 and 82 sandwiching ionomer resin film layers 84, 88 and 89.
A ninth embodiment of the laminated article according to this invention is shown in FIG. 9. The laminated article 90 comprises a high impact transparent plastic layer 92 laminated to the ionomer resin layer 94. The ionomer resin layer 94 is thinner than the plastic layer 92.
A tenth embodiment of the laminated article according to this invention is shown in FIG. 10. The laminated article 100 comprises an ionomer resin film 104 laminated to a plastic layer 102. The article is further provided with a hardcoat 106 on the otherwise exposed surface of the resin layer 104 in order to protect the resin layer from scratching, abrasion and other similar damage. In addition a protective hardcoat layer can also be provided on the otherwise exposed surface of the plastic layer 102 (not shown). As previously stated with respect to the second embodiment, useful "hardcoat" compositions are described in U.S. Letters Patent No. 4,027,073 and U.S. patent application Ser. No. 473,790, filed Mar. 10, 1983, and assigned to the owner of this application.
An eleventh embodiment of the laminated article according to this invention is shown in FIG. 11. The laminate 110 comprises an ionomer resin film 116 between two plastic layers 112, 114. Hardcoat layers on the plastic layers may also be provided (not shown).
A twelfth embodiment of the article according to the present invention is shown in FIG. 12. Therein, a single ionomer resin film layer 122 has a thickness greater than fifty mils.
Finally a thirteenth embodiment of a laminated article according to the present invention is shown in FIG. 13. Therein, a laminate 130 comprises an outer glass layer 131; an ionomer resin layer 132 sandwiched the outer glass layer 131 and an inner glass layer 133; a second ionomer resin layer 133 laminated to the second glass layer 132; and a polyester film 135 laminated to the second ionomer resin layer 133. This embodiment is particularly useful for windshield laminates where the interior polyester film helps to provide an anti-lacerative surface which will help to prevent injury in the event of high impact contact. The preferred polyester film is MYLAR with a thickness of 0.005
The ionomer or ionomer resin of the invention is obtained by combining a copolymer of ethylene-methacrylic acid or ethylene-acrylic acid and a polyamine which contains at least two --CH 2 --NH 2 groups, and the R may contain: (--CH 2 NH 2 ) x ; (--NH 2 ) x ; or, (R'R"NH) y , where x=1 or more, and y=0 or more. R' and R" may be any organic groups. The preferable structure of the diamine is:
NH.sub.2 CH.sub.2 --(R)--CH.sub.2 NH.sub.2
where R contains from one to twenty five carbon atoms; R may be aliphatic, alicylic or aromatic; and R may also contain: ##STR3##
Examples of the diamines which can be used are
1, 12-diaminododecane;
1, 6-diaminohexane;
Bis [1, 3-aminomethyl]cyclohexane (BAC); and 1, 3-diaminomethylxylene.
Adding from 0.3% to 10% by weight one of the diamines or polyamines of this group or a mixture thereof to the copolymers neutralizes the free acidic carboxyl groups: ##STR4## forming an amine salt: ##STR5##
In addition, the copolymer may already be partially neutralized with up to 90% of a metal cation such as sodium or other alkali metal, ammonium salt, zinc or even an aluminum salt. A particular example of such a copolymer is "SURLYN"1601, manufactured by the Polymer Products Department of the DuPont Company. A data information sheet on SURLYN 1601 ionomer resin is available under No. E-29173(7/81). The information in this technical release, including the rheology curves, is incorporated herein by reference. SURLYN type 1707 is also a preferred sodium ionomer resin for use in this invention as a starting material for mixing with the polyamine.
When the ethylene-methacrylic acid or ethylene-acrylic acid copolymer is heated above the melting point (usually over 200° F. and preferably to 280° F.) the polymeric chains lose most of their crystallinity and the chains, particularly the polyethylene segments, become intertwined. When this randomization and intertwining occur in the presence of a diamine, the amine groups interact with the free carboxylic acid groups and form an amine salt locking the disorder which occurs at the high temperature into the polymer.
At the higher temperatures, this reaction is reversible and even reversible in the presence of the diamine; the polymer chains become less crystalline and random and become interwound upon being heated above the melting point. As the copolymer begins to cool, the diamine or polyamine reacts and forms amine salts with the free carboxyl groups. The more basic the amine and the less strictly hindered the amine groups, i.e., --CH 2 --NH 2 groups, the stronger the bonds which are formed with the carboxyl, and the higher the temperature at which a non-reversible diamine or polyamine salt forms. In the case of the described diamine, the diamine salt can form non-reversibly at a temperature above the temperature whereat significant segments of the polyethylene chain or other segments of the polymeric chain can re-align and start forming larger crystalline segments. The diamine or polyamine in effect cross-links the copolymer through the carboxyl groups in the form of diamine or polyamine salts in a more random and less crystalline form. This cross-linking is reversible so that the ionomer sheet when heated to the melting point becomes formable and processible and can be used in a laminate or substrate or even used alone without any additional substrate.
Some amount of irreversible cross-linking can be accomplished if desired by heating the ionomer resin film to 325°-400° F. for varying lengths of time under vacuum to cause the amine salts to convert to amides: ##STR6##
The conversion to the amides may range from 10%-100% conversion, depending on the length of time of the heating. This high temperature cross-linking of the finished article provides some cross-linking and heat set and thereby can increase the melting point of the ionomer sheet in the final article if desired in addition to adding toughness to the sheet material.
The primary aliphatic or alicyclic diamines or polyamines containing the --CH 2 --NH 2 group can form the strongest bonds with the carboxyl group and therefore form the amino salt bond at the highest possible temperature of all the diamines or polyamines. If there is too great a distance between the --NH 2 groups and the chain is not rigid, too much flexibility occurs and the cross-linking effect becomes diminished and the diamine or polyamine may not be effective. Similarly, if the --CH 2 --NH 2 groups are too close together there is steric interaction between the resultant amine salt groups causing weakening of amine salt formation and additionally, the amino groups cannot bridge the gap as readily between active carboxyl groups.
CH 2 --NH 2 group maximizes the basicity and minimizes steric inhibition to forming the amino salt bond. When secondary diamines or aromatic diamines are used, the basicity or steric inhibition to salt formation does not cause the diamine salt formation to occur soon enough on cooling of the ionomer sheet and haze formation occurs.
Primers may also be used to promote adhesion between the ionomer resin and the glass and polycarbonate respectively. Primers suitable for glass, and the glass/ionomer resin interface in particular, may include silanes, such as those produced under the registered trademarks "Z-6040" and "Z-6020" by Dow Chemical Company. Other primers suitable for the polycarbonate/ionomer resin interface in particular, include organic amines, usually in a diluted solution with an inert solvent (unlikely to attack the polycarbonate, e.g. alkanes and alcohols), such as aliphatic or polyethylene amines or ethanolamines, and specifically diethylenetriamine. Other specific primers include diisocyanates (toluene diisocyantate) and polyacrylic acid (produced under the registered trademark "ACRYSOL" by the Rohm and Haas Company).
The basic building block of this invention, namely a laminate comprising a sheet of glass laminated to an ionomer resin film, may be used in multiples to achieve nearly any desired strength. This is illustrated in FIG. 8, wherein lamina of varying thickness of glass are sandwiched with lamina of varying thickness of ionomer resin film. By varying the number and the thickness of the lamina of glass and ionomer resin film, always, however, laminating in the alternating order shown in the FIGURE, it is possible to produce laminates having resistance to exceptionally large force. The principles of this invention may also be applied to curved laminates articles, such as windshields and face masks. The laminates and films shown in the figures are flat merely for purposes of facilitating illustration. Where transparency is not critical, the bonding techniques taught herein may be used for laminating metal as well as glass such as illustrated in FIG. 7. Furthermore, by producing the ionomer resin neutralized by the diamines or polyamines discussed herein, it is possible to provide a clear film of substantial thickness and strength so that it can be used alone; i.e., without any additional laminated layer for support or enhanced impart resistance.
In providing the ionomer resin film of this invention, the preferred combination is ethylene methacrylic acid or ethylene-acrylic acid and a polyamine. The polyamines are preferably diamines of the general formula: ##STR7## wherein: contains 1-25 carbon atoms and may contain =NH, =N--CH 3 ,
--CH2-0--CH2, other hetero atoms and halogens
R 1 , R 2 , R 3 and R 4 =H, alkyl, alicyclic, and aromatic groups
y=1 or more
The preferred general structural formula of the diamine is:
NH 2 CH 2 --R--CH 2 NH 2
where R contains from 1-25 carbon atoms and R may be aliphatic, alicyclic or aromatic.
Still further, particularly useful polyamines are those of the formula: ##STR8## wherein: R"' and R"=H, alkyl, aryl
q=1, 2 or 3
z-0-5
w=0-5
y=0-4
x+y=4
x=0-4
or (CH 2 NH 2 ) x ##STR9## wherein w is 0 to 4
x is 0 to 3
y is 0 to 5
z is 0 to 5
with the proviso that x+w≦1 or ##STR10## wherein R 1 , R 2 and R 3 are each alkyl of 1-4 carbon atoms, and M is CR, nitrogen, phenyl and cycloalkyl having 5-8 carbon atoms, wherein R is hydrogen, alkyl of 1-4 carbon atoms or lower alkyl amine.
Specific polyamines of this generic formula which can be used in the invention include:
Tris-(2-aminoethyl) amine,
Tris-(3-aminopropyl) amine,
Tris-(3-aminopropyl) methane,
1,2,4-tri(3-aminopropyl) benzene,
1,2,4-tri(2-aminoethyl) cyclohexane,
Tetra(2-aminoethyl) tetrahydro dicyclopentane,
1,2,3-tri-(3-aminopropyl) propane,
Tetrakis(2-aminoethyl) ethane,
Tetrakis(2-aminoethyl) methane,
1,2,3,4-Tetra(2-aminoethyl) butane and
N,N,N',N'-tetra(2-aminoethyl) ethylene diamine.
Other polyamines which are particularly useful in combination with the ethylene methacrylic acid or ethylene-acrylic acid are: isophorone diamine; 1,12 dodecanediamine; 1,6 hexanediamine; 1,4 butane diamine; 1,3 bis (aminomethylcyclohexane); 1,3 diaminomethyl benzene; m-xylenediamine; diethylene triamine; N, N, bis (3-aminopropyl) piperidine; 1,4 butanediamine; 1,5 pentanediamine; triethylenetetramine; tris(2-aminoethyl) amine and trimethyl hexamethylene diamine.
The ionomer resin film produced from the polyamines is intended to have a thickness of at least 50 mils when unsupported and at least 10 mil or more when used in laminates. Furthermore, this ionomer resin has superior optical clarity, i.e. light transmission greater than 60%, over previous ionomer resins of similar compositions for such thickness.
Various acid polymers which are useful in the invention in addition to ethylene-methacrylic acid copolymer and ethylene-acrylic acid copolymer include polyacrylic acid copolymer and polymethacrylic acid copolymer.
The ionomer resin of the invention may also be prepared from the esterified form of the polymer material rather than beginning with the free acid. For example, the polymer starting materials may be: polymethylmethacrylate (PMMA), other polyacrylic esters, polyethylene and methamethacrylate copolymer, and ethylene methylacrylate (EMA) copolymer, styrene methylmethacrylate copolymer. Various other ester forms may be used as well, including the methyl, ethyl and propyl forms.
Furthermore, it is also possible to use only the partially esterified polymers, for example: ##STR11## wherein: R=H or CH 3
w=at least 1
x=at least 1
y=at least 1
z=at least 10
(It is preferable to have some small amount of water present during the reaction of the polyamine with the ester groups.)
It has been found that the ionomer resin films formed from the esterified or partially esterified forms of these polymers also have the required optical clarity in the ranges of thickness greater than 50 mils as well as in the film thickness ranges less than 50 mils.
In yet another combination of materials to produce the ionomer resin of the invention, it is possible to begin with a partially neutralized ionomer resin; an ionomer resin which has been previously at least partially neutralized with a metal. Thereafter, more complete the neutralization of the ionomer resin with the polyamine can be achieved according to the invention. Partially neutralized ionomer resin such as the ionomer resin SURLYN, previously discussed, which is either partially neutralized with zinc or sodium or both is a preferable starting resin. This partially neutralized resin may be combined with any of the polyamines of the general formula previously discussed.
EXAMPLE 1
In utilizing the preferred diamines discussed above in conjunction with the ionomers, satisfactory results have been obtained by mixing 1%-6% by weight of 1, 12 diaminododecane, 1,6 diaminohexane, and BAC(bis [1,3-aminomethyl] cyclohexane) to a commercial sodium ionomer (about 50% neutralized) of a copolymer of ethylene methacrylic acid (SURYLN 1701-DuPont). The resulting ionomer films whether containing both sodium and diamine salts or with diamine salts alone produced even tougher (more impact resistant), more solvent resistant, higher melting point films, more ultraviolet resistant and most importantly, higher clarity films and sheets.
EXAMPLE 2
A diamine was selected from the group of diamines listed below and was mixed with a partially neutralized Surlyn 1707 resin. The mixture was added to the resin port of a small extruder (Wayne Machine Co., 7-in extruder, with a nine inch die). The extruding barrel was maintained at 325°-400° F. A 50 to 60 mil film was extruded and cut into six inch squares stacked to about one-half inch thickness and laminated between two primed one-fourth inch glass plates in an autoclave at 255° F. for three minutes under 150-200 psi pressure in a vacuum. The final ionomer layer was optically clear and one-half inch or more in thickness with a light transmittance over 50%.
The following amines in the weight percents given were combined with Surlyn 1707. For each amine, excellent optical clarity was achieved.
______________________________________Amine Weight Percent______________________________________(a) tris (2-aminoethyl)amine 1(b) 1,6-hexanediamine 1(c) BAC 1(d) isophorone diamine 3(e) tetrakis(2-aminoethyl)ethane 1______________________________________
EXAMPLE 3
Polyethyleneacrylic acid (Primacore 3440) was mixed with 8% by weight BAC and then heated to 280° F. in a flat plate mold under pressure to produce a flat, thick (1/2 inch) amine ionomer plate. The material was clear with some haze.
EXAMPLE 4
The same procedure disclosed in Example 3 was repeated using polyethylenemethacrylic acid, NUCREL by Dupont, plus water and 5% by weight 1, 12 diaminododecane. The resultant material was clear with some haze, but was exceptionally hard and tough.
EXAMPLE 5
In this example, 5% BAC was mixed with Nucrel (Dupont) resin The mixture was heated to 300° F. The resin obtained was very hard, tough and optically clear.
EXAMPLE 6
The inch plastic sheet of Example 3 was further heated at 350° F. for 15 minutes. The plastic became very hard. As discussed above, this heating is believed to be the result in the partial conversion of the amine salt ionomer to a cross-linked polyamide formation.
It is to be understood that the foregoing examples are given for the purpose of illustration and that any other suitable glass, ionomer resin, reinforcing plastics or the like could be used provided that the teachings of this disclosure are followed.
This invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention. | An ionomer resin, a film or sheet of the ionomer resin and laminated articles having a lamina of the ionomer resin film are provided. The ionomer resin consists of ionically crosslinked ethylene-methacrylic acid copolymer or ethylene-arcylic acid copolymer which is neutralized with a polyamine. The polyamine neutralized ionomer resin may be formed into a film or sheet which may be self-supporting or may be laminated to glass to form a safety glass. | 2 |
PRIOR APPLICATION
This application is a U.S. national phase application that is based on and claims priority from International Application No. PCT/SE2009/050482, filed 4 May 2009.
BACKGROUND AND SUMMARY OF THE INVENTION
Field of Invention
This application relates to a high pressure sluice.
The high pressure sluice feeder is an important component of the conventional Kamyr continuous pulping system. The high pressure sluice feeder is used to transfer steamed wood chips from a chute in a liquid from low pressure to high pressure and towards the top of the continuous digester. A typical high pressure sluice feeder comprises a rotor having through extending pockets disposed in first and second sets spaced along the axis of rotation of the rotor housing. The rotor pockets each have opposite end openings which function as both inlets and outlets depending upon the rotational position of the rotor, and the trough pockets in the rotor are offset from those of the other, typically orthogonally offset in the rotor in each set and 45 degrees offset between sets of trough pockets. The housing encloses the rotor and has an exterior periphery with first, second, third to fourth ports for each set disposed around the exterior periphery for registry with the inlets to and outlets from the pockets of the rotor. The first and third ports are opposite, typically arranged vertically, and the second and fourth ports are opposite, typically arranged horizontally, and the first and second ports may be adjacent in succession in the direction of rotation of the rotor.
In a conventional high pressure feeder are screen means disposed in the third port of each set for screening chips out of the liquid passing through the third port, and a low pressure pump is connected to the third port to provide the suction for sucking liquid through the third port while filling the rotor pocket with a chip slurry. However, in later conventional system with high pressure feeders have this screen means been removed, as is standard in Metso Papers Compact Feed™ systems. A high pressure pump or source of high pressure liquid is operatively connected to the fourth port to provide the flow of liquid under high pressure through the fourth port for emptying of the rotor pocket filed with chip slurry towards the digester via the second port. Normally the first port is on the top, and the third port on the bottom, the first port connected to the chip chute, and the second port connected to the top of the digester.
The rotor is slightly conical and have a form of a truncated cone and rests in a corresponding conical interior of the housing, and in order to minimize leakage of flow from the high pressure side to the low pressure side, i.e. from one rotor pocket to another, could the axial position of the rotor be adjusted in order to minimize the play between the conical circumference of the rotor and the conical interior surface of the housing. An automated system for pushing the rotor in the axial direction in order to maintain a predefined play, as these surfaces tends to wear, is shown in U.S. Pat. No. 7,350,674, and sold by Metso Paper.
However, it has been found that some high pressure feeders are worn down rather fast, and it has been identified that this accelerated process of wear is due to high content of abrasive particles in the chip slurry handled by the high pressure feeder. In some pulp mills is the chips stored in piles in outdoor wood yards, and even stored on gravel surface, and when chips are brought to feed systems is also some amount of grit and gravel brought together with the chips. This is often the main reason for excessive wear in subsequent equipment.
According to the present invention, the root cause of this excessive wear and an effective cure for reducing this wear has been found. After testing it has surprisingly been found that the wear rate in high pressure sluice feeders could be reduced by more than half, thus extending the operational time for a high pressure feeder between overhauls by over 100%.
According to the present invention the problem has been solved by providing flush out grooves in the complementary conical surface of the high pressure sluice feeder that are not swept by the trough going pockets of the rotor. Even though the play between the outer conical surface of the rotor and the conical interior surface of the housing should be kept at a minimum, could a better function be obtained by arranging grooves in these surfaces that are not swept by the trough going pockets of the rotor. Said grooves directing a flush out flow of liquid trough the grooves, thus emptying all abrasive particles caught in the grooves into the trough pockets of the rotor and into the passing chip slurry flow.
According to one embodiment of the invention are the grooves located in the rotor, and in another embodiment are the grooves located in the housing. These two alternatives could be combined such that grooves are located in the rotor as well as the housing.
It is the primary object of the present invention to provide for extended available operational life time between necessary overhauls of the high pressure sluice feeder. This and other objectives of the invention will become apparent from following description of the invention, and from the enclosed claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross sectional side view of a high pressure feeder;
FIG. 2 a is a side view of the rotor of the high pressure feeder with FIG. 2 b showing a detail of the rotor in an enlarged view;
FIG. 3 a is a cross sectional view of the housing in a high pressure feeder, as seen from below in FIG. 1 , and FIG. 3 b is a tilted view as seen from below in FIG. 1 , while FIG. 3 c is a detail of the housing in an enlarged view;
FIG. 4 a is a cross sectional view of the housing in a high pressure feeder, as seen from above in FIG. 1 , and FIG. 4 b is a tilted view as seen from above in FIG. 1 ;
FIG. 5 is a detail view of the groove in the housing.
DETAILED DESCRIPTION
FIG. 1 shows the general design of a conventional high pressure sluice feeder 1 according state of the art. The high pressure sluice feeder 1 is connected to a chip chute 9 , which is supplied with steamed chips from a conventional steaming vessel or bin, the chips being slurried with liquid. The chute 9 is connected to a first port P 1 of a housing 20 . The housing 20 also has a second port P 2 , a third port P 3 , and a fourth port P 4 , disposed at 90 degrees interval in the direction of rotation R of the rotor 10 within the housing 20 . The rotor 10 has at least first and second through going pockets in one set (only one pocket shown in FIG. 1 ), wherein each individual pocket could be rotated into position of liquid communication with first and third ports, P 1 and P 3 respectively, of the housing, as shown in FIG. 1 , or into position of liquid communication with second and fourth ports P 2 and P 4 of the housing.
Connected to the fourth port P 4 is any suitable means for supplying high pressure liquid L HP . Said high pressure liquid L HP could be obtained from a high pressure pump or a pressurized liquid from the digester, depending upon how the high pressure sluice feeder is installed in the feeding system.
A sealing liquid L WL is conventionally added to the housing via supply pipe 23 . The sealing liquid is most often white liquor, or the cooking chemicals used, as most cooking systems need addition of cooking liquor early on, and thus could be added in this way and in this position. The sealing liquid is added to the end gable of the housing and lubricates the conical surfaces of the rotor and housing that are held in a predetermined minimal play against each other in order to minimize the leakage of high pressure liquid from one pocket to another, i.e. from the high pressure position to the low pressure position.
As shown in FIG. 1 is the individual pocket of the rotor 10 filled with chip slurry when the pocket is in register with ports P 1 and P 3 , which is the low pressure position of the rotor. As shown in the figure could a screen member 24 be located in the port P 3 , such that the chips are prevented from escaping from the pocket, while liquid L LP being drained therefrom.
When the pocket is filled with chips in the position shown in FIG. 1 , the rotor 10 continue the rotation in the direction R and expose the through going pocket for the second and fourth ports, P 2 and P 4 respectively. In this position the through going pocket is pressurized from the port P 4 with a liquid L HP that expels the chips held in the pocket trough port P 2 and further to the pressurized digester. Once the pocket is emptied, the rotor 10 continues to rotate in the direction R, and once again occupies the filling position as shown in FIG. 1 , but at this time with inlets and outlets of the through going pocket being switched.
In a conventional manner is also the inside of the conical surface of the housing equipped with “pre-filling” grooves 22 running in the circumferential direction of the housing. The purpose of these “pre-filling” grooves 22 is to introduce a smooth pressurization of the through going pocket as it approaches the high pressure position. These grooves are running in the circumferential direction and should not be mixed up with the grooves of the invention, having an entirely different objective.
FIG. 2 a illustrates the rotor 10 of the high pressure sluice feeder which is tapered from a first end thereof to the second gable end 104 . As the wear increase the play between rotor and housing could the entire rotor be pushed towards the gable end, i.e. towards the right hand side in FIG. 2 a . The rotor 10 includes a plurality of (e.g. four shown here) diametrically through-going pockets TP 1 1 , TP 2 1 , TP 1 2 , and TP 2 2 . Typically two pockets, TP 1 1 (only inlet and outlet contours shown) and TP 2 1 are disposed in a first set, and two pockets TP 1 2 and TP 2 2 in a second set, the sets spaced along the axial direction of the rotor, and the pockets of one set are orthogonally offset to each other in the circumferential direction, and sets being offset from each other at 45 degrees. The entire rotor 10 is journal led in bearings and connected to any appropriate drive unit via shaft ends 101 and 102 .
According to the invention is the rotor equipped with a cleaning groove 105 a as shown in FIG. 2 a . This groove is arranged in the conical surfaces of the rotor, and said groove being oriented in a direction having at least one component running in parallel with the generatrix of the conical surface of the rotor, i.e. inclined as shown in FIG. 2 a . Said groove 105 a connecting one pocket TP 2 2 with a fluid pressure source, said fluid pressure source establishing a flushing action trough said groove in a direction having one component in parallel with the generatrix of the conical surface of the rotor 2 a . As shown in this embodiment is the groove 105 a running between first and second through going pockets, here TP 2 2 and TP 2 1 in the outer peripheral surface of the conical rotor 10 , and wherein the fluid pressure source is the pocket held at high pressure. The groove 105 a is thus located in the outer peripheral surface of the conical rotor 10 that are not swept by the trough going pockets of the rotor during rotation thereof. If any grit or gravel is caught in this area it will not be emptied out into the trough going pockets when they are passing.
In FIG. 2 b is shown a detail view of this groove 105 a . In order to catch gravel and grit being caught between the conical surfaces of the rotor and the housing, in parts of the housing not being swept by the openings of the trough going pockets, it is sufficient if this groove has a width and depth laying in the range of 2-5 millimeter in the entire extension of the groove. In the embodiment shown in FIG. 2 b is the width and depth 3 millimeters, and preferably with a radius of 1.5 millimeter in the bottom of the groove.
According to the invention could also the housing 20 be equipped with cleaning grooves 205 b as shown in FIGS. 3 a and 3 b . One groove 205 b is running between a gable end 204 a of the interior conical surface 203 of said housing to the neighboring port P 1 2 closest to the gable end in said housing, and wherein the fluid pressure source is the supply of sealing liquid L WL added to the gable end of the rotor. As shown could a similar groove be applied, running between the opposite end 204 b of the interior conical surface 203 of said housing to the neighboring port P 1 1 closest to the gable end in said housing. In FIG. 3 c is shown a detail view of this groove 205 b , having similar preferred configuration as that of FIG. 2 b . These ports P 1 1 and P 1 2 are both preferably located in the low pressure position of the high pressure sluice feeder, and preferably the inlet ports for the low pressure filling position.
In FIGS. 4 a and 4 b is shown that a cleaning grove 205 a also could be located running between two neighboring ports P 3 1 and P 3 2 in the interior conical surface of the housing. These ports P 3 1 and P 3 2 are both preferably located in the low pressure position of the high pressure sluice feeder, and preferably the inlet ports for the low pressure filling position.
The groove 205 b , as shown by the upper groove in FIG. 3 a , and its general direction DG is shown in FIG. 5 , stretching from a port P 1 1 in the housing and towards the end opposite the gable end 204 , and located in the interior conical surface of the housing that is not swept by the trough going channels of the rotor. The groove being oriented in a general direction DG having at least one component C 1 running in parallel with the generatrix of the interior conical surface of the housing, i.e. with an inclination angle of α, in relation to the generatrix of the interior conical surface of the housing as shown in FIG. 5 . The inclination angle α is lying in the range 10-50 degrees, preferably 30 degrees, in relation to the generatrix of the interior conical surface of the housing or rotor. Said groove 205 b establishing a flushing action trough said groove in a general direction DG having one component C 1 in parallel with the generatrix of the interior conical surface of the housing. If the rotor is equipped with a similar groove for cleaning purposes, this groove in the rotor is preferably oriented such that it may cross the groove of the housing when passing, as indicated by dotted lines of a ghost groove 105 b in the rotor.
While the invention has been herein shown and described in what is presently conceived to be the most preferred embodiment, it will be apparent to those skilled in the art that many modifications may be made thereof within the scope of the invention, which scope is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and procedures.
While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims. | The high pressure sluice feeder has a conical rotor mounted in a housing having a complementary conical interior. The rotor has a plurality of trough-going pockets arranged offset to each other in the rotor. The housing has ports distributed evenly around a circumference of the housing and exposed to the pockets during rotation of the rotor. A conical exterior surface of the rotor or the conical interior surface of the housing is equipped with a flush-out groove. The groove catches any abrasive particles caught between the complementary conical surfaces of the rotor and housing. The abrasive particles are flushed out towards the trough-going pockets of the rotor when one end of the groove is pressurized by either one neighboring trough-going pocket or a sealing liquid supply to a gable end of the rotor/housing. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of co-pending U.S. Provisional Patent Application Ser. No. 60/554,077, filed on Sep. 18, 2007, which application is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to completion operations in a wellbore. More particularly, the invention relates to running casings in extended reach wells.
[0004] 2. Description of the Related Art
[0005] In extended reach wells or wells with complex trajectory, operators often experience difficulty in running a liner/casing past a certain depth or reach. The depth or reach of the liner is typically limited by the drag forces exerted on the liner. If further downward force is applied, the liner may be pushed into the sidewall of the wellbore and become stuck or threaded connections in the liner may be negatively impacted. As a result, the liners are prematurely set in the wellbore, thereby causing hole downsizing.
[0006] Various methods have been developed to improve liner running abilities. For example, special low friction centralizers or special fluid additives may be used to reduce effective friction coefficient. In another example, floating a liner against the wellbore may be used to increase buoyancy of the liner, thereby reducing contact forces.
[0007] There is a need, therefore, for apparatus and methods to improve tubular running operations.
SUMMARY OF THE INVENTION
[0008] In one embodiment, a method of running tubulars, such as liners and casings, include running the tubular to a target depth or to a depth determined by frictional resistance. Then, the tubular may be urged down by generating an active piston force between a seal and a liner shoe.
[0009] In one embodiment, an apparatus for running a liner into a wellbore may comprise an inner string having a bore therethrough, and a tubular engagement device coupled to the inner string. The device is operable to engage the interior of the liner. The device is also operable to facilitate movement of the liner relative to the inner string using a fluid pressure.
[0010] In one embodiment, a method of running a liner into a wellbore may comprise the step of positioning an inner string in the liner. The inner string may have a seal member operable to engage the interior of the liner. The method may also include the step of pressurizing an internal area between the seal member and the interior of the liner to provide a pressure force against the interior of the liner. The method may further include the step of displacing the liner relative to the inner string using the pressure force.
[0011] In one embodiment, a method of running a liner into a wellbore may comprise the step of positioning an inner string into the liner. The inner string may have a piston operable to engage the interior of the liner. The method may also include the step of actuating the piston to engage the interior of the liner. The method may further include the step of displacing the liner relative to the inner string using the piston.
[0012] In one embodiment, a method of running a liner into a wellbore may comprise the step of positioning an inner string into the liner. The inner string may have a device operable to engage the interior of the liner. The method may also include the step of engaging the interior of the liner using the device. The method may further include the step of supplying a fluid pressure to move the liner relative to the inner string.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0014] FIGS. 1A and 1B are views of a liner equipped with an inner string having a piston device. The liner is located at a first position in a wellbore.
[0015] FIGS. 2A and 2B are views of the liner in a second location in the wellbore, the liner being moved by actuation of the piston device.
[0016] FIG. 3 shows the liner having an expandable liner hanger expanded against a casing.
[0017] FIG. 4 shows an inner string equipped with another embodiment of the piston device. As shown, the piston device is in the unactuated position.
[0018] FIG. 5 shows the piston device of FIG. 4 in the actuated position.
[0019] FIG. 6 shows an inner string equipped with yet another embodiment of the piston device. As shown, the piston device is in the unactuated position.
[0020] FIG. 7 shows the piston device of FIG. 6 in the actuated position.
[0021] FIG. 8 shows a telescopic liner assembly.
[0022] FIG. 9 shows the telescopic liner assembly extended using an embodiment of the piston device.
[0023] FIG. 10 shows expansion of the telescopic liner assembly after extension.
DETAILED DESCRIPTION
[0024] In one embodiment, a liner 100 is assembled conventionally on a rig floor. The liner 100 is suspended from the rig floor and held in place using slips, such as from a spider or a rotary table. A false rotary table may be mounted above the slips holding the liner 100 . Then, an inner string 120 is run into the liner 100 , as shown in FIGS. 1A and 1B .
[0025] FIG. 1A is an external view of the liner 100 , and FIG. 1B is an internal view of the liner 100 . The liner 100 may include a casing shoe 130 disposed at an end thereof. A lower portion of the inner string 120 may include a device, such as a seal cup 125 , to allow pressurizing the internal area 115 of the liner 100 between the shoe 130 and the seal cup 125 . In one embodiment, the inner string 120 may include a piston assembly instead of or in addition too the seal cup 125 . The inner string 120 may also include an anchoring or latching device 140 to prevent relative axial movement between liner 100 and the inner string 120 . In one embodiment, the inner string 120 may be a drill pipe. The inner string 120 may also include an expansion tool 160 , such as a rotary expander, a compliant expander, and/or a fixed cone expander, to expand at least a portion of the liner 100 .
[0026] The inner string 120 may be run all the way to the shoe 130 or to any depth within the liner 100 . After the inner string is located in the liner 100 , the anchoring device 140 may be actuated to secure the inner string 120 to the liner 100 . After the inner string 120 is assembled, the liner 100 is released from the rig floor and is run into the wellbore 150 to a particular depth. The depth to which the liner 100 is run may be limited by torque or drag forces, as illustrated in FIG. 1A . In one embodiment, a ball 132 or dart is dropped to close a circulation valve at the shoe 130 . In another embodiment, circulation may also be closed using a control mechanism, such as a velocity valve or another closure device known to a person of ordinary skill. When the released ball 132 passes by the anchor device 140 , the ball 132 may de-actuate the anchor device 140 to release the liner 100 from the inner string 120 . After the ball 132 closes circulation, pressure is supplied to increase the pressure in the internal area 115 between the seal cup 125 and the shoe 130 . The pressure increase exerts an active liner pushing force against the shoe 130 , thereby causing the liner 100 to travel down further into the wellbore 150 . In this respect, the active liner pushing force is equal to the pumping pressure multiplied by the piston area within the liner 100 . The internal pressurization of the liner 100 may help alleviate a tendency of the liner 100 to buckle as it travels further into the wellbore 150 . In one embodiment, the active liner pushing force is provided in a direction that is similar or parallel to the direction of the wellbore 150 . In this respect, the effect of the drag forces is reduced to facilitate movement of the liner 100 within the wellbore 150 .
[0027] After the liner 100 has been extended into the wellbore 150 , the pressure in the internal area 115 may be released. The inner string 120 may then be lowered and/or relocated in the liner 100 , thereby repositioning the seal cup 125 . The tools, such as the seal cups 125 , may be positioned at the top or at any location within the liner 100 . The seal cups 125 may be stroked within the liner 100 numerous times. The pressure may again be supplied to the internal area 115 to facilitate further movement of the liner 100 within the wellbore 150 . This process may be repeated multiple times by releasing the pressure in the liner 100 and re-locating the inner string 120 .
[0028] In one embodiment, a hydraulic slip 170 , or other similar anchoring device, may be coupled to the liner 100 and/or the inner string 120 to resist any reactive force provided on the string or the liner that will push the string or liner in an upward direction or in any direction toward the well surface. The hydraulic slip 170 may be operable to prevent the inner string 120 from being pumped back to the surface, while forcing the liner 100 into the wellbore 150 . In one embodiment, the hydraulic slip 170 may be coupled to the interior of the liner 100 to engage the inner string 120 . In one embodiment, the hydraulic slip 170 may be coupled to the inner string 120 to engage the liner 100 . In one embodiment, the hydraulic slip 170 may be coupled to the exterior of the liner 100 to engage the wellbore 150 .
[0029] In another embodiment, the liner 100 may optionally include an expandable liner hanger 108 , as shown in FIGS. 2A and 2B . As shown, the liner hanger 108 is equipped will a sealing member 109 , such as an elastomer. FIG. 2A is an external view of the liner 100 , and FIG. 2B is an internal view of the liner 100 . When the inner string 120 is pulled all the way to the liner hanger 108 , the expansion tool 160 may be activated. The expansion tool 160 may be activated from a (collapsed) travel position to a (enlarged) working position. The liner hanger 108 may be expanded using any tool and technique known in the art. Expansion of the liner hanger 108 anchors the liner 100 and seals the liner top. Alternatively, a conventional liner hanger may be used.
[0030] FIG. 3 shows the liner hanger 108 expanded and set against casing 101 . The inner string 120 may then be pulled out of the wellbore 150 . In one embodiment, the liner 100 may be cemented in the wellbore 150 . In one embodiment, the liner 100 may be radially expanded. In one embodiment, the liner 100 may be expanded at one or more discrete locations to effect zonal isolation or sand production control. In one embodiment, the liner 100 may include a sand control screen, such as an expandable screen.
[0031] FIG. 4 shows one embodiment of the inner string 120 (also referred to as a “running tool”) equipped with a jack piston device 200 . The inner string 120 is shown disposed in a liner 100 . The liner 100 is provided with a shoe 130 . The inner string 120 includes a seal 225 for sealing against the liner 100 . In one embodiment, the piston device 200 includes a housing 250 movably disposed on the exterior of the inner string 120 . A port 255 is provided to allow fluid communication between the interior of the inner string 120 and the housing 250 . Seals may be disposed between the piston device 200 and the inner string 120 . A slip 260 is supported in the housing 250 and is radially movable in response to a pressure in the housing 250 .
[0032] In operation, the liner 100 and the inner string 120 may be lowered into the casing 101 to a depth at which further progress is impeded. A ball 132 is released into the liner 100 to seat in a valve in the shoe 130 to close fluid circulation. Pressure increase in the inner string 120 causes the slips 260 to move radially outward into engagement with the liner 100 . Further pressure increase causes the piston device 200 to move relative to the inner string 120 and in the direction of the shoe 130 . This movement is due to the fluid pressure acting on piston surface 258 provided in the housing 250 . Because the piston device 200 is engaged to the liner 100 via the slips 260 , the liner 100 is moved along with the piston device 200 , thereby advancing the liner 100 further into the wellbore 150 . In FIG. 5 , it can be seen that the piston device 200 has moved closer to the seal 225 and that the liner 100 has traveled down. After the liner 100 has moved, the pressure in the inner string 120 may be reduced to retract the slips 260 . Thereafter, the piston device 200 may be re-pressurized so that the process may be repeated to advance the liner 100 further into the wellbore 150 . In one embodiment, the inner string 120 may be repositioned so that the process may be repeated to advance the liner 100 further into the wellbore 150 . In one embodiment, the pressure contained by the seal 225 also acts on the liner shoe 130 so that the combination of this pressure plus the force exerted by the piston device 200 pushes the liner 100 further into the wellbore 150 .
[0033] In one embodiment, a biasing member 270 may be provided to facilitate repositioning of the piston device 200 relative to the port 255 . In one embodiment, the biasing member 270 may be a spring that is disposed between the seal 225 and the piston device 200 , such that it engages a shoulder on the inner string 120 at one end and engages the housing 250 at the opposite end. As the piston device 200 is moved toward the seal 225 , the spring is compressed, as shown in FIG. 5 . After the pressure in the inner string 120 is reduced and the slips 260 are disengaged from the liner 100 , the spring will exert a biasing force to move the piston device 200 to its original position relative to the port 255 .
[0034] In one embodiment, a plurality of piston devices may be used on an inner string 120 . FIG. 6 shows an inner string 120 with two piston devices 301 and 302 . In one embodiment, a first biasing member 311 is disposed between a shoulder 305 on the inner string 120 and the first piston device 301 , and a second biasing member 312 is disposed between the two piston devices 301 and 302 . A landing seat 320 is provided in the inner string 120 to close circulation between the inner string 120 and the liner 100 , and/or the inner string 120 and the wellbore 150 . In one embodiment, the inner string 120 may be equipped with the seal configuration as shown in FIG. 1B or 4 .
[0035] In operation, a ball 132 is released into the inner string 120 to seat in the landing seat 320 to close fluid circulation. Pressure increase in the inner string 120 causes the slips 360 to move radially outward into gripping engagement with the liner 100 . Further pressure increase causes the piston devices 301 and 302 to move relative to the inner string 120 and in the direction of the shoe 130 . This movement is due to the piston surfaces 358 provided in the housings 350 of the piston devices 301 and 302 . Because the piston devices 301 and 302 are engaged to the liner 100 via the slips 360 , the liner 100 is moved along with the piston devices 301 and 302 , thereby advancing the liner 100 further into the wellbore 150 .
[0036] In FIG. 7 , it can be seen that the piston devices 301 and 302 have moved closer to the shoulder 305 and that the liner 100 has traveled down. After the liner 100 has moved, the pressure in the inner string 120 may be reduced to retract the slips 360 . After the pressure is reduced, the biasing members 311 and 312 are operable to move the piston devices 301 and 302 back to their original position. Thereafter, the piston devices 301 and 302 may be re-pressurized so that the process may be repeated to advance the liner 100 further into the wellbore 150 . In one embodiment, the inner string 120 may be repositioned so that the process may be repeated to advance the liner 100 further into the wellbore 150 .
[0037] In one embodiment, the inner string 120 may be used to extend a telescope liner assembly 400 , as shown in FIG. 8 . FIG. 8 shows the liner assembly 400 having an inner liner 401 at least partially disposed within an outer liner 402 . One or more seals 405 may be disposed between the inner liner 401 and the outer liner 402 . In one embodiment, the inner string 120 disposed in the liner assembly 400 is equipped with a seal piston configuration as shown in FIGS. 1B and/or 4 .
[0038] A seal piston 420 may be positioned in the liner assembly 400 such that the seal 125 is adapted to engage the outer liner 402 , as shown in FIG. 9 . The seal piston 420 may further include an anchoring device 140 and/or an expansion tool 160 . In one embodiment, a seal piston 410 may be positioned in the inner liner 401 such that the seal 125 engages the inner liner 401 . The seal piston 410 may further include an anchoring device 140 and/or an expansion tool 160 . In one embodiment, the inner string 120 may include two seal pistons 410 and 420 with one located in each liner 401 and 402 . In one embodiment, the inner string 120 may equipped with jack piston devices instead of the seal piston and/or both.
[0039] In operation, the inner string 120 , having either seal piston 420 or 410 , or both, may be introduced into the liner assembly 400 and secured in the liner assembly 400 via anchoring devices 125 . The inner string 120 and the liner assembly 400 may be lowered into the wellbore 150 to a predetermined depth. As described above, a ball, a dart, or other triggering mechanism may be used to deactivate one or both of the anchoring devices 125 from engagement with the liner assembly 400 . Pressure may then be supplied through the inner string 120 , thereby pressurizing the liner assembly 400 against the seal pistons 420 and/or 410 , and providing an active liner force to telescope the inner liner 401 into the wellbore 150 relative to the outer liner 402 . Further pressurization may then allow the inner liner 401 and the outer liner 402 to advance further into the wellbore 150 relative to the inner string 120 . The pressure may be released to allow relocation and/or removal of the inner string 120 . This process may be repeated to even further advance the liner assembly 400 into the wellbore 150 .
[0040] In one embodiment, the liner assembly 400 may be equipped with a locking mechanism such that after the inner liner 401 is extended, the piston devices 410 and/or 420 may be used to move the inner liner 401 and the outer liner 402 .
[0041] In one embodiment, the inner liner 401 and the outer liner 402 may initially be releasably connected. During operation, the inner and outer liners 401 and 402 are moved along in the wellbore 150 . At a predetermined depth, the releasable connection may be sheared or otherwise disconnected, thereby allowing the inner liner 401 to be extended relative to the outer liner 402 .
[0042] In one embodiment, after the inner liner 401 has been extended from the outer liner 402 , the inner liner 401 may be optionally radially expanded, as shown in FIG. 10 . In one embodiment, the outer liner 402 may also be radially expanded.
[0043] In further embodiments, the liner (any of 100 , 400 , 401 , 402 ) may be equipped with a drilling or reaming device at or on the shoe, such that the borehole may be drilled or reamed during the running operation.
[0044] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | An apparatus for running a liner into a wellbore may comprise an inner string, a device coupled to the inner string that is operable to engage the interior of the liner and facilitates running of the liner into the wellbore, and a control mechanism operable to control fluid communication between the interior of the liner and the wellbore. A method of running a liner into a wellbore may comprise the steps of providing an inner string into the liner, wherein the inner string includes a device operable to engage the interior of the liner, engaging the interior of the liner, and supplying a fluid pressure to move the liner relative to the inner string to advance the liner into the wellbore. | 4 |
BACKGROUND OF THE INVENTION
The present invention is directed to an improved process for producing metal castings using the lost foam casting process.
Lost Foam Casting (Full Mold Casting) involves placing a plastic pattern of the desired cast part in sand and then pouring molten metal onto the plastic casting causing it to vaporize. The molten metal exactly reproduces the plastic pattern to provide the ultimate casting. Many patents have issued covering the Lost Foam Casting process.
It is known that polystyrene, the major polymer used in this application, produces surface defects when casting iron due to carbon residues left by the polymer. When casting low carbon steel the carbon formed from the polystyrene dissolves in the metal degrading the properties of the cast part. A number of patents describe variations in the Lost Foam Casting process that are intended to minimize the residues left by the polymer after the metal has been poured. Most of these variations involve changing the coating on the pattern or changing the flask in which the casting is made. For example, U.S. Pat. Nos. 4,448,235 and 4,482,000 describe a variable permeability casting designed to avoid entrapment of polymer vapors in the casting. U.S. Pat. No. 3,572,421 describes a flask containing many air breathing holes to allow the escape of polymer degradation products to decrease the formation of carbon. Similarly, U.S. Pat. Nos. 3,842,899, 3,861,447 and 4,612,968 describe the addition of vacuum to the casting flask to aid in the removal of the polymer residues.
The Dow Chemical Company has reported the development of a polymethyl methacrylate foam bead useful to replace polystyrene for the casting process. (Moll and Johnson, "Eliminate the Lustrous Carbon Defect With New Moldable Foam", Evaporative Foam Casting Technology II Conference, Nov. 12-13, 1986, Rosemont, Ill.). Although this polymer reduces residues left on the cast part, it carries with it other disadvantages. The higher glass transition temperature (130° C.) of the polymer causes longer molding cycles when preparing patterns. It uses a Freon blowing agent which has been shown to cause corrosion of molds. It also rapidly gives off a large volume of gas when castings are made. It is very difficult to control the evolution of gas and often the molten metal is blown back out of the flask.
There is still a great need for a polymer that provides the advantages of polystyrene but produces no carbon defects. U.S. Pat. Nos. 4,773,466 and 4,763,715 teach to use polycarbonate copolymers and terpolymers, respectively, to make patterns for the lost foam casting process.
BRIEF SUMMARY OF THE INVENTION
We have now developed a process for the preparation of a polystyrene suitable for Lost Foam Casting applications. Pre-expanded beads prepared from polystyrene containing from 0.50 to 1.50 percent of tert-butyl cumyl peroxide can be used in conventional steam molding equipment to produce low density patterns. Iron castings made from the polystyrene/peroxide material show significantly less signs of lustrous carbon defects. The polystyrene smoothly and controllably decomposes to give a smooth, clean casting.
DETAILED DESCRIPTION OF THE INVENTION
The polymers useful in the present invention include polystyrene having a molecular weight of 150,000 to 300,000.
Preparation of low density, strong uniform patterns with good surface finish requires small spherical beads of polymer having bead diameters between 100 and 1000 microns, preferably between 200 and 500 microns. The beads, once formed, are impregnated with blowing agent by a process similar to that used for polystyrene as described in U.S. Pat. No. 2,983,692 issued to Koppers Company. The beads are suspended in an aqueous suspension containing finely divided calcium phosphate and an anionic surfactant. Any of a number of low boiling blowing agents such as butane, n-pentane, isopentane, cyclopentane, hexane, carbon dioxide, Freon 11, Freon 113, Freon 114, Freon 22, or mixtures of these is then added, and the suspension is sealed and heated to 95°-135° C. for 2-6 hours. During the impregnation, a high temperature peroxide, tert-butyl cumyl peroxide, is added in amounts between 0.5 and 1.5 weight-percent. The use of high temperature peroxide is necessary to prevent its decomposition during the normal expansion and molding of the casting.
After impregnation the beads are acid washed and air dried to remove water. The blowing agent incorporation is determined by weighing a sample of dry beads before and after subjecting them to 130° C. for 2 hours. The weight loss under these conditions corresponds to the blowing agent level. Typically 5-15 weight percent of blowing agent can be incorporated into the beads.
The impregnated beads are then pre-expanded to about 0.5 to 2 pounds per cubic foot (pcf) by subjecting them to atmospheric steam. The lowest density beads are obtained using vacuum expansion as described by Immel (U.S. Pat. No. 3,577,360). Using these techniques 0.8 to 1.2 pcf beads are obtained. A typical expansion/cooling cycle requires 3 minutes. Following pre-expansion the beads are aged to allow for equilibration of gas pressure within the foam cells.
The expanded, aged beads are molded into the desired pattern using techniques similar to those described by Stastny in U.S. Pat. No. 2,787,809. The mold cavity is charged with pre-expanded, aged beads Steam is then injected into the mold to cause the particles to fill voids and fuse to form a single pattern. The mold is then cooled until the pattern can be removed without distortion.
The molded patterns are attached, using a hot-melt adhesive, to runners and a down-sprue to allow the molten metal to travel from the top of the flask to the pattern. The pattern and runners are then coated with a refractory such as an aqueous silica suspension and allowed to dry. The coated pattern is then placed on a bed of loose sand in the casting flask and covered with loose, unbonded sand leaving only the top of the down-sprue exposed for metal pouring. The sand is then compacted around the pattern by vibration of the casting flask.
Molten grey iron at 1427° C. is then poured onto the down-sprue. The molten metal flows into the flask, vaporizing the polymer and forming the cast part. After the flask is allowed to cool for approximately ten minutes the sand and casting are dumped out of the flask. The casting is an exact replica of the polymer pattern with a smooth surface with significantly less signs of carbon deposits.
The following examples are meant to illustrate, but not limit the invention.
EXAMPLE I
Fine granular polystyrene beads with a size range of 200 to 500 microns and having a molecular weight of 225,000 were impregnated with a mixture of pentanes by placing 100 cc of distilled water, 2.0 g of tricalcium phosphate, 2.0 g of a 1% aqueous solution of sodium dodecylbenzene sulfonate, and 0.1 g polyoxyethylene(20)-sorbitan monolaurate, 0.23 g of paraffin wax together with 100 g of polymer beads and 7.8 g of pentanes in an 8 oz citrate bottle. If peroxide was added, the peroxide was added at this time. The bottles were capped and heated in an oil bath with agitation for 3/4 hr. to 105° C. and maintained at 105° C. for 2 hours. The bottle was then cooled, opened and the polymer was separated from the aqueous layer. The beads were then washed with 100 cc of 0.1N HCl to remove residual phosphate salts, centrifuged and tray dried.
The impregnated beads were lubed with Silene-732D from PPG Co., and pre-expanded in a Drispander made by Kohler General Corporation. They were then aged at least one day.
The beads were then injected into a 3/4"×53/4"×133/4" plaque mold and heated to 100° C. with steam to expand and fuse. Following cooling for 2 minutes the pattern was ejected from the mold to provide a smooth surface, resilient pattern with good mechanical strength.
The pattern was then attached to a runner system and sprue with Styro Bond 52.3 Hot Melt Adhesive from Thiem Corporation. The runner and sprue system was also prepared using the copolymer. An identical polystyrene pattern was also attached to the same sprue with a separate runner. The pattern was then coated with Styro Kote Refractory Coating (a silica based aqueous coating from Thiem Corp.) and allowed to dry overnight. The assembled pattern was then packed with loose sand into a casting flask and the sand was compacted using a General Kinematics Compaction Table.
Five patterns were made from each of six compositions as follows:
______________________________________Sample Density Additive______________________________________A 0.90 0.50% tert-Butyl Cumyl PeroxideB 0.80 1.25% tert-Butyl Cumyl PeroxideC 1.05 0.50% Di-tert-butyl PeroxideD 0.95 1.25% Di-tert-Butyl PeroxideE 1.00 NoneF 1.35 None (PS Mol. Wt. = 280,000)______________________________________
Molten grey iron at 1427° C. was then poured onto the sprue to fill the patterns and evaporate the polymers. After cooling for 10 minutes, the castings were dumped out of the flask. The relative rankings of the casting surfaces are shown in Table I.
TABLE I______________________________________Ranking Sample Ranking Sample______________________________________1 B 16 E2 C 17 E3 B 18 D4 B 19 C5 E 20 D6 C 21 C7 C 22 B8 A 23 D9 A 24 A10 B 25 D11 A 26 F12 E 27 F13 D 28 F14 E 29 F15 A 30 F______________________________________ Ranking 1 has the least amount of lustrous carbon Ranking 30 has the most amount of lustrous carbon
The castings produced using the higher molecular weight polystyrene patterns (F) showed obvious pitting and lustrous carbon on the surface. The use of the tert-butyl cumyl peroxide showed significant improvement over all the other additives. As is seen from Table I, Sample B had four of the five samples ranked in the top 10. In contrast, the patterns produced using di-tert-butyl peroxide (C and D) showed no improvement over the lower molecular weight polystyrene (E). | The evaporative casting of molten metals has been shown to produce casting having smooth surfaces with significantly less sign of carbon deposits thereon by using a polystyrene containing a high temperature peroxide, tert-butyl cumyl peroxide. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to blends comprising 1 to 100% of (co)polyamide-block graft copolymers and 99 to 0% of flexible polyolefins. The flexible polyolefins may be, for example, ethylene/alkyl (meth)acrylate copolymers, and the (co)polyamide-block graft copolymers consist of a polyolefin backbone to which polyamide grafts are attached. More specifically, the polyamide-block graft copolymer is obtained, for example, by reacting a polyamide having a chain end terminated by an amine group with a polyolefin containing acid anhydride groups incorporated either by polymerization or by grafting of an unsaturated carboxylic acid anhydride.
THE TECHNICAL PROBLEM
[0002] Flexible polyolefins, having a flexural elastic modulus of less than 100 MPa at 23° C., have crystalline melting points of between 100° C. and 60° C. and are characterized by a significant drop in elastic modulus as soon as the temperature approaches the melting point. In general, this handicaps their use in an environment characterized by high temperature rises such as, for example, inside a motor-vehicle compartment or exposure to full sunlight. These flexible polyolefins are, for example, copolymers of ethylene and a comonomer such as an alpha-olefin, vinyl acetate or an alkyl (meth)acrylate.
THE PRIOR ART
[0003] U.S. Pat. No. 3,976,720 describes polyamide-block graft copolymers and their use as a compatibilizer in polyamide/polyolefin blends. Their production starts by polymerizing caprolactam in the presence of N-hexylamine in order to obtain a PA-6 having an amine end group and an alkyl end group. This PA-6 is then attached to a backbone consisting of an ethylene/maleic anhydride copolymer by reacting the anhydride with the amine end group of the PA-6. A polyamide-block graft copolymer is thus obtained which is used in an amount ranging from 2 to 5 parts by weight in order to compatibilize blends comprising 75 to 80 parts of PA-6 and 20 to 25 parts of high-density polyethylene (HDPE). The polyethylene in these blends is dispersed in the form of 0.3 to 0.5 μm nodules in the polyamide.
[0004] U.S. Pat. No. 3,963,799 is very similar to the previous patent and specifies that the flexural modulus of blends of PA-6, HDPE and compatibilizer is about 210 000 psi to 350 000 psi, i.e. 1400 to 2200 MPa.
[0005] Patent EP 1 036 817 describes graft copolymers similar to those described in the aforementioned US patents and their use as a primer or binder for inks or paints on a polyolefin substrate. For these usages, the copolymers are applied in solution in toluene.
[0006] U.S. Pat. No. 5,342,886 describes polymer blends comprising a compatibilizer and, more particularly, polyamide/polypropylene blends. The compatibilizer consists of a polypropylene backbone to which polyamide grafts are attached. The compatibilizer is prepared from a polypropylene homopolymer or copolymer (the backbone) to which maleic anhydride is grafted. Separately, a polyamide with a monoamine terminal group, that is to say one having an amine end group and an alkyl end group, is prepared. Then, by melt blending, the monoamine-terminated polyamide is attached to the polypropylene backbone by reacting the amine functional group with the maleic anhydride.
[0007] It has now been discovered that these polyamide-block graft copolymers organize themselves into a structure on a nanometric scale, which gives them exceptional thermomechanical strength properties. Surprisingly, these properties are maintained when these polyamide-block graft copolymers are redispersed in flexible polyolefins such as flexible ethylene polymers.
[0008] Thus, when it is desired to increase the operating temperature of a flexible polyolefin, it can be modified by attaching a polyamide graft thereto. If the backbone of the flexible polyolefin does not contain a reactive site for the attachment of the graft, it is firstly necessary to introduce it into the backbone by grafting. Depending on the desired properties, it is not necessary to attach grafts to the entire flexible polyolefin but it is sufficient to do so only over a fraction of this flexible polyolefin [this being done in situ]. It is also possible to blend this modified part with the rest of the flexible polyolefin. It is also possible, in order to increase the operating temperature of a flexible temperature, to add another polyolefin to it, but one containing polyamide grafts. Preferably, this other polyolefin must be compatible with the flexible polyolefin. Depending on the amount added, this polyolefin must preferably have a flexibility such that the flexibility of the blend is not excessively modified.
BRIEF DESCRIPTION OF THE INVENTION
[0009] The present invention relates to a blend comprising, by weight, the total being 100%:
[0010] 1 to 100% of a polyamide-block graft copolymer consisting of a polyolefin backbone and on average at least one polyamide graft, characterized in that copolymer:
[0011] the grafts are attached to the backbone by the residues of an unsaturated monomer (X) having a functional group capable of reacting with an amine-terminated polyamide,
[0012] the residues of the unsaturated monomer (X) are attached to the backbone by grafting or copolymerization from its double bond;
[0013] 99 to 0% of a flexible polyolefin having an elastic flexural modulus of less than 150 MPa at 23° C. and a crystalline melting point between 60° C. and 100° C.
[0014] These polyamide-block graft copolymers organize themselves into a structure on a nanometric scale, which gives them exceptional thermomechanical strength properties. The nanometric nature is even more pronounced when the amount of polyamide with respect to the backbone is within certain proportions.
[0015] The blends of the present invention are characterized by an elastic modulus plateau above the melting point of the flexible polyolefin, which results in practice in an improvement in the hot creep properties and the possibility of use at markedly higher temperatures than those of the flexible polyolefin used by itself. Such properties are particularly desirable in cable jackets, in trim for the internal lining of cars, such as heat-sheathed skins, which is thermoformed, calendered or made by slush molding, in tarpaulins and geomembranes exposed to the external environment and in adhesives.
[0016] The present invention also relates to an adhesive essentially consisting of the above blends of a graft copolymer and a flexible polyolefin. Preferably, the blend is reduced to a powder, and then this powder is placed between the substrates to be bonded. The powder may be deposited, for example, on one of the substrates or on the other, or even on both substrates, are then pressed against each other while heating sufficiently for the powder to melt. The bond is obtained after cooling.
[0017] The present invention also relates to films that can be obtained by extruding the above blends of a graft copolymer and a flexible polyolefin.
[0018] The present invention also relates to tarpaulins or geomembranes that can be obtained by extruding the above blends of a graft copolymer and a flexible polyolefin. These tarpaulins or geomembranes advantageously consist of at least one layer of the above blends combined with a backing. Preferably, they are obtained by extrusion-coating them onto a backing which may be a nonwoven, a woven, for example made of PET, or a PET mesh.
[0019] The present invention also relates to all products obtained by calendering since the above blends of a graft copolymer and a flexible polyolefin are very easily converted by this process and do not adhere to the rolls of the calendering machine.
[0020] The present invention also relates to power cables or telecommunication cables, comprising a protective layer based on the above blends of a graft copolymer and a flexible polyolefin. Advantageously, the layer used in the power cables also contains a fire retardant such as, for example, magnesium hydroxide.
[0021] The present invention also relates to the use of the above blends of a graft copolymer and a flexible polyolefin in powder form for the slush molding process, as well as to the articles obtained. The term “slush molding” used by a person skilled in the art denotes a molding process characterized in that powder flows freely on a hot mold (hereafter called slush molding process). Slush molding is used to manufacture skins for dashboards, door panels and consoles in the motor vehicle field. The powder is brought into contact with the hot mold, for example, by the slush molding technique, the powder melting to form a skin. This skin has a very soft feel and has no residual stresses, thereby making it possible, during ageing of the skin, to prevent the risk of cracks appearing caused by residual stresses relaxing. The invention also relates to the articles obtained by this slush molding process and by rotomolding.
DETAILED DESCRIPTION OF THE INVENTION
[0022] With regard to the flexible polyolefin, this is an olefin homopolymer or a copolymer of at least one alpha-olefin and of at least one other copolymerizable monomer, provided that, of course, the modulus and crystalline melting point conditions are satisfied.
[0023] Advantageously, the flexible polyolefin is chosen from polyethylene homopolymers or copolymers.
[0024] By way of comonomers, mention may be made of:
[0025] alpha-olefins, advantageously those having from 3 to 30 carbon atoms.
[0026] Examples of alpha-olefins having 3 to 30 carbon atoms as possible comonomers include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, 1 -dococene, 1 -tetracocene, 1-hexacocene, 1 -octacocene and 1 -triacontene. These alpha-olefins may be used by themselves or as a mixture of two or more of them;
[0027] esters of unsaturated carboxylic acids such as, for example, alkyl (meth)acrylates, the alkyls possibly having up to 24 carbon atoms.
[0028] Examples of alkyl acrylates or methacrylates are especially methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate and 2-ethylhexyl acrylate;
[0029] vinyl esters of saturated carboxylic acids such as, for example, vinyl acetate or vinyl propionate;
[0030] unsaturated epoxides.
[0031] Examples of unsaturated epoxides are especially:
[0032] aliphatic glycidyl esters and ethers such as allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate, glycidyl itaconate, glycidyl acrylate and glycidyl methacrylate; and
[0033] alicyclic glycidyl esters and ethers, such as 2-cyclohex-1-ene glycidyl ether, diglycidyl cyclohexene-4-5-dicarboxylate, glycidyl cyclohexene-4-carboxylate, glycidyl 2-methyl-5-norbornene-2-carboxylate and diglycidyl endo-cis-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate;
[0034] unsaturated carboxylic acids, their salts and their anhydrides.
[0035] Examples of anhydrides of an unsaturated dicarboxylic acid are especially maleic anhydride, itaconic anhydride, citraconic anhydride and tetrahydrophthalic anhydride;
[0036] dienes such as, for example, 1,4-hexadiene.
[0037] The flexible polyolefin may comprise several comonomers.
[0038] By way of example, mention may be made of:
[0039] low-density polyethylene (LDPE)
[0040] linear low-density polyethylene (LLDPE)
[0041] very low-density polyethylene (VLDPE)
[0042] polyethylene obtained by metallocene catalysis, that is to say polymers obtained by the copolymerization of ethylene and of an alpha-olefin such as propylene, butene, hexene or octene in the presence of a single-site catalyst generally consisting of a zirconium or titanium atom and of two alkyl cyclic molecules linked to the metal. More specifically, the metallocene catalysts are usually composed of two cyclopentadiene rings linked to the metal. These catalysts are frequently used with aluminoxanes as cocatalysts or activators, preferably methylaluminoxane (MAO). Hafnium may also be used as the metal to which the cyclopentadiene is attached. Other metallocenes may include transition metals of Groups IV A, V A and VI A. Metals from the series of lanthanides may also be used;
[0043] EPR (ethylene-propylene-rubber) elastomers;
[0044] EPDM (ethylene-propylene-diene) elastomers;
[0045] blends of polyethylene with an EPR or an EPDM;
[0046] ethylene/alkyl (meth)acrylate copolymers possibly containing up to 60%, and preferably 2 to 40%, by weight of (meth)acrylate;
[0047] ethylene/alkyl (meth)acrylate/maleic anhydride copolymers obtained by copolymerizing the three monomers, the proportions of (meth)acrylate being as in the above copolymers and the amount of maleic anhydride being up to 10% and preferably 0.2 to 6% by weight;
[0048] ethylene/vinyl acetate/maleic anhydride copolymers obtained by copolymerizing the three monomers, the proportions being the same as in the above copolymer.
[0049] By way of example, mention may be made of flexible ethylene copolymers, such as the copolymers obtained by the radical copolymerization at high pressure of ethylene with vinyl acetate, (meth)acrylic esters of (meth)acrylic acid and of an alcohol having from 1 to 24, and advantageously from 1 to 9, carbon atoms, radical terpolymers using, in addition, a third monomer chosen from unsaturated monomers copolymerizable with ethylene, such as acrylic acid, maleic anhydride and glycidyl methacrylate. These flexible copolymers may also be copolymers of ethylene with alpha-olefins containing from 3 to 8 carbon atoms, such as EPRS, very low-density copolymers of ethylene with butene, hexene or octene, having a density of between 0.870 and 0.910 g/cm 3 which are obtained by metallocene or Ziegler-Natta catalysis. By the term “flexible polyolefins” we also mean blends of two or more flexible polyolefins.
[0050] The invention is particularly useful for ethylene/alkyl (meth)acrylate copolymers. The alkyl may have up to 24 carbon atoms. Preferably, the (meth)acrylates may be chosen from those mentioned above. These copolymers advantageously comprise up to 40%, and preferably 3 to 35%, by weight of (meth)acrylate. Their MFI is advantageously between 0.1 and 50 (at 190° C.-2.16 kg).
[0051] Advantageously, the flexural modulus is between 5 and 150.
[0052] With regard to the polyamide-block graft copolymer, this may be obtained by reacting a polyamide having an amine terminal group with the residues of an unsaturated monomer X attached by grafting or copolymerization to a polyolefin backbone.
[0053] This monomer X may, for example, be an unsaturated epoxide or an anhydride of an unsaturated carboxylic acid. The anhydride of an unsaturated carboxylic acid may be chosen, for example, from maleic, itaconic, citraconic, allylsuccinic, cyclohex-4-ene-1,2-dicarboxylic, 4-methylenecyclohex-4-ene-1,2-dicarboxylic, bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic and x-methylbicyclo[2.2.1]hept-5-ene-2,2-dicarboxylic anhydrides. Advantageously, maleic anhydride is used. It would not be outside the scope of the invention to replace all or part of the anhydride with an unsaturated carboxylic acid such as, for example, (meth)acrylic acid. Examples of unsaturated epoxides were mentioned above.
[0054] With regard to the polyolefin backbone, a polyolefin is defined as a homopolymer or an alpha-olefin or diolefin copolymer, such as, for example, ethylene, propylene, 1-butene, 1-octene and butadiene. By way of example, mention may be made of:
[0055] polyethylene homopolymers and copolymers, particularly LDPE, HDPE, LLDPE (linear low-density polyethylene), VLDPE (very low-density polyethylene) and metallocene polyethylene;
[0056] propylene homopolymers or copolymers;
[0057] ethylene/alpha-olefin copolymers, such as ethylene/propylene, EPR (ethylene-propylene-rubber) and ethylene/propylene/diene (EPDM);
[0058] styrene/ethylene-butylene/styrene (SEBS), styrene/butadiene/styrene (SBS), styrene/isoprene/styrene (SIS) and styrene/ethylene-propylene/styrene (SEPS) block copolymers;
[0059] copolymers of ethylene with at least one product chosen from salts or esters of unsaturated carboxylic acids, such as alkyl (meth)acrylate (for example methyl acrylate), or vinyl esters of saturated carboxylic acids such as vinyl acetate, the proportion of comonomer possibly being up to 40% by weight.
[0060] Advantageously, the polyolefin backbones to which the X residues are attached are polyethylenes grafted by X or ethylene/X copolymers which are obtained, for example, by radical polymerization.
[0061] With regard to the polyethylenes to which X is grafted, polyethylene is understood to mean homopolymers or copolymers.
[0062] By way of comonomers, mention may be made of:
[0063] alpha-olefins, advantageously those having from 3 to 30 carbon atoms. Examples are mentioned above. These alpha-olefins may be used by themselves or as a mixture of two or more of them;
[0064] esters of unsaturated carboxylic acids such as, for example, alkyl (meth)acrylates, the alkyls possibly having up to 24 carbon atoms; examples of alkyl acrylates or methacrylates are, especially, methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate and 2-ethylhexyl acrylate;
[0065] vinyl esters of saturated carboxylic acids such as, for example, vinyl acetate or vinyl propionate;
[0066] dienes such as, for example, 1,4-hexadiene;
[0067] the polyethylene may comprise several of the above comonomers.
[0068] Advantageously, the polyethylene, which may be a blend of several polymers, comprises at least 50% and preferably 75% (in mol) of ethylene and its density may be between 0.86 and 0.98 g/cm 3 . The melt flow index (viscosity index at 190° C./2.16 kg) is advantageously between 5 and 100 g/10 minutes.
[0069] By way of example of polyethylenes, mention may be made of:
[0070] low-density polyethylene (LDPE);
[0071] high-density polyethylene (HDPE);
[0072] linear low-density polyethylene (LLDPE);
[0073] very low-density polyethylene (VLDPE);
[0074] polyethylene obtained by metallocene catalysis;
[0075] EPR (ethylene-propylene-rubber) elastomers;
[0076] EPDM (ethylene-propylene-diene) elastomers;
[0077] blends of polyethylene with an EPR or an EPDM;
[0078] ethylene/alkyl (meth)acrylate copolymers possibly containing up to 60%, and preferably 2 to 40%, by weight of (meth)acrylate.
[0079] The grafting is an operation known per se.
[0080] With regard to ethylene/X copolymers, that is to say those characterized in that X is not grafted, these are copolymers of ethylene with X and optionally with another monomer which may be chosen from the comonomers that were mentioned above for the ethylene copolymers intended to be grafted.
[0081] Advantageously, ethylene/maleic anhydride and ethylene/alkyl (meth)acrylate/maleic anhydride copolymers are used. These copolymers comprise from 0.2 to 10% by weight of maleic anhydride and from 0 to 40%, and preferably 5 to 40% by weight of alkyl (meth)acrylate. Their MFI is between 5 and 100 (190° C./2.16 kg). The alkyl (meth)acrylates have already been described above. The melting point is between 60 and 100° C.
[0082] Advantageously, there are on average at least 1.3, preferably from 1.3 to 10, and better still from 1.3 to 7 mol of X per chain attached to the polyolefin backbone. A person skilled in the art can easily determine this number of moles of X by FTIR analysis.
[0083] With regard to the amine-terminated polyamide, a polyamide is understood to mean the product of the condensation:
[0084] of one or more amino acids, such as aminocaproic, 7-amino-heptanoic, 11 -aminoundecanoic and 12-aminododecanoic acids of one or more lactams, such as caprolactam, oenantholactam and lauryllactam;
[0085] of one or more salts or mixtures of diamines, such as hexamethylenediamine, dodecamethylenediamine, metaxylylenediamine, bis-p-aminocyclohexylmethane and trimethylhexamethylenediamine with diacids, such as isophthalic, terephthalic, adipic, azelaic, suberic, sebacic and dodecanedicarboxylic acids;
[0086] or of mixtures of several monomers, resulting in copolyamides.
[0087] It is also possible to use blends of polyamides or of copolyamides. It is advantageous to use PA-6, PA-11, PA-12, a copolyamide containing 6-type units and 11-type units (PA-6/11), a copolyamide containing 6-type units and 12-type units (PA-6/12) and a copolyamide based on caprolactam, hexamethylenediamine and adipic acid (PA-6/6,6).
[0088] Advantageously the grafts are homopolymers consisting of caprolactam residues, 11-aminoundecanoic acid residues or dodecalactam residues or of copolyamides consisting of residues chosen from at least two of the three above monomers.
[0089] The degree of polymerization may vary over wide proportions; depending on its value, it is a polyamide or a polyamide oligomer. In the rest of the text, both expressions will be used for the grafts without distinction.
[0090] In order for the polyamide to have a monoamine terminal group, it is sufficient to use a chain terminator of formula
[0091] characterized in that:
[0092] R 1 is hydrogen or a linear or branched alkyl group containing up to 20 carbon atoms;
[0093] R 2 is a linear or branched alkyl or alkenyl group having up to 20 carbon atoms, a saturated or unsaturated cycloaliphatic radical, an aromatic radical or a combination of the above. The chain terminator may, for example, be laurylamine or oleylamine.
[0094] Advantageously, the amine-terminated polyamide has a molar mass of between 1000 and 5000 g/mol and preferably between 2000 and 4000 g/mol.
[0095] The preferred amino acid monomers or lactams for the synthesis of the monoaminated oligomer as claimed in the invention are chosen from caprolactam, 11-aminoundecanoic acid or dodecalactam. The preferred monofunctional polymerization terminators are laurylamine and oleylamine. The polycondensation defined above is carried out as claimed in the usual known processes, for example at a temperature generally between 200 and 300° C., under vacuum or under an inert atmosphere, and with the reaction mixture being stirred. The average chain length of the oligomer is determined by the initial molar ratio of the polycondensable monomer or lactam to the monofunctional polymerization terminator. In order to calculate the average chain length, it is usual to count one chain terminator molecule per oligomer chain.
[0096] The addition of the monoaminated polyamide oligomer to the polyolefin backbone containing X is carried out by reacting an amine functional group of the oligomer with X. Advantageously, X carries an anhydride or acid functional group; thus, amide or imide links are created.
[0097] The addition of the amine-terminated oligomer to the polyolefin backbone containing X is preferably carried out in the melt. Thus, it is possible, in an extruder, to mix the oligomer and the backbone at a temperature generally of between 230 and 250° C. The average residence time of the melt in the extruder may be between 15 seconds and 5 minutes, and preferably between 1 and 3 minutes. The efficiency of this addition is evaluated by selectively extracting the free polyamide oligomers, that is to say those which have not reacted to form the final polyamide-block graft copolymer.
[0098] The preparation of such amine-terminated polyamides, and their addition to a polyolefin backbone containing X, is described in U.S. Pat. No. 3,976,720, U.S. Pat. No. 3,963,799, U.S. Pat. No. 5,342,886 and FR 2 291 225.
[0099] The polyamide-block graft copolymers of the present invention are characterized by a nanostructured organization with polyamide lamellae having a thickness of between 10 and 50 nanometers.
[0100] Advantageously, the proportion of polyamide-block graft copolymer is from 5 to 50% per 95 to 50% of flexible polyolefin, respectively.
[0101] The blends of the invention have a very good creep resistance at temperatures at least equal to 80° C. and possibly up to 130° C., that is to say they do not fail below 25 kPa.
[0102] The blends of the invention may be prepared by melt-blending in extruders (single-screw or twin-screw), Buss kneaders, Brabender mixers and, in general, the usual devices for mixing thermoplastics, and preferably twin-screw extruders. The blends of the invention may also include processing aids such as silica, ethylenebisamide, calcium stearate or magnesium stearate. They may also include antioxidants, UV stabilizers, mineral fillers and coloration pigments.
[0103] The blends of the invention may be prepared in one step in an extruder. Introduced into the first zones are the backbone containing X (for example, an ethylene/alkyl (meth)acrylate/maleic anhydride copolymer) and the amine-terminated polyamide, and then a few zones further downstream the flexible polyolefin. It is also possible to introduce all the ingredients dry-blended into the first zone of the extruder.
EXAMPLES
Example 1
[0104] An ethylene terpolymer, having a flexural modulus of 30 MPa, a weight-average molar mass M w of 95 000 g/mol, copolymerized with 28% by weight of ethyl acrylate and 1.2% by weight of maleic anhydride and having a melt flow index of 6 g/10 minutes (at 2.16 kg/190° C.), was mixed in a Leistritz® corotating twin-screw extruder fitted with several mixing zones, having a temperature profile of between 180 and 220° C., with an amine-terminated polycaprolactam of 2500 g/mol molecular mass, synthesized as claimed in the method described in U.S. Pat. No. 5,342,886. This terpolymer contains on average 1 anhydride unit per chain. The proportions introduced into the extruder were such that the backbone polyolefin/amine-terminated polyamide ratio was 80/20 by weight.
[0105] The product obtained consisted, by weight, of 50% of the terpolymer to which a polyamide graft was attached, of 14% of the amine-terminated PA-6 and of 36% of the terpolymer.
[0106] The product thus produced was analysed by transmission electron microscopy, revealing the polyamide phase by a treatment consisting in making ultrafine sections and then in treating them in an aqueous phosphotungstic acid solution for 30 minutes at 60° C.; the PA appeared dark. The morphology of this alloy was characterized by polyamide particles having a mean size of between 1 and 3 microns. The thermomechanical properties of this product were mediocre and the product broke after a time of less than 1 minute at a stress of 25 kPa at 150° C.
Example 2
[0107] A grafting reaction in the extruder was repeated under the conditions in Example 1 with the amine-terminated polyamide of Example 1 and an ethylene/ethyl acrylate/maleic anhydride terpolymer of 50 000 M w , having a respective comonomer weight composition of 77/20/3, a melting point of 76° C., a flexural modulus of 30 MPa and a melt flow index of 70 g/10 minutes (at 2.16 kg/190° C.). This terpolymer contained 2.3 anhydride units per chain. The proportions introduced into the extruder were such that the backbone polyolefin/amine-terminated polyamide ratio was 80/20 by weight and the ratio of the amine functional groups to the maleic anhydride functional groups was 0.35. SEM analysis showed that the polymer obtained was organized in terms of lamellae having a thickness of about 10 nm. This polymer was characterized by an elastic modulus plateau of between 9 and 3 MPa between 80° C. and 180° C. This polymer had an elongation of 8% in the creep test under a stress of 50 kPa at 180° C.
[0108] Analysis of the polymer obtained showed that it contained (i) 50% by weight of the terpolymer to which polyamide grafts were attached, (ii) 45% of terpolymer, having a flexural modulus of 30 MPa and not having reacted with the amine-terminated polyamide and (iii) 5% of the amine-terminated PA-6.
Example 3
[0109] A grafting reaction as claimed in Example 1 was repeated with an ethylene/butyl acrylate/maleic anhydride radical terpolymer having an M w of 105 000 and a respective weight composition of 80/17/3, a melting point of 95° C., a flexural modulus of 60 MPa and an MFI of 5 g/10 minutes (at 2.16 kg/190° C.) and a monoaminated PA-6 having a molecular mass of 2400 g/mol. This terpolymer contained 4.8 anhydride units per chain. The proportions introduced into the extruder were such that the backbone polyolefin/amine-terminated polyamide ratio was 80/20 by weight.
[0110] The polymer obtained was nanostructured. It was characterized by an elastic plateau of between 10 and 8 MPa between 100° C. and 180° C. This polymer had an elongation of 5% in the creep test under a stress of 200 kPa at 120° C. This copolymer had an elongation of 8% in the creep test under a stress of 50 kPa at 180° C.
[0111] Analysis of this polymer showed that it contained more than 50% of the terpolymer to which polyamide grafts were attached via the backbone (the terpolymer) (ii) the other 50% being the terpolymer, of 60 MPa flexural modulus, that had not reacted with the amine-terminated polyamide and a small amount of amine-terminated PA-6.
Example 4
[0112] Flexible polyolefins were mixed in a twin-screw extruder, having a temperature profile of between 180 and 220° C., with the nanostructured polymer obtained in Example 3. Next, the creep resistance of these modified polyolefins was tested at various temperatures and under various loads. The analysis of the response of these materials is given in Table 1. This shows the creep behavior of polyolefins modified by a PA-6 block graft copolymer. The compositions by weight were:
[0113] EVATANE® 28.05 is an EVA copolymer having a vinyl acetate content of 28% by weight and an MFI (190° C./2.16 kg) of 5 g/10 minutes;
[0114] LOTRYL® 30 BA 02 is an ethylene/n-butyl acrylate copolymer having an acrylate weight content of 30% and an MFI of 2 g/10 minutes (190° C./2.16 kg).
[0115] Indicated in the “Content” column of Table 1 are the amount of EVATANE®, or of LOTRYL®, and of the polymer obtained in Example 3, respectively. This polymer of Example 3 is the same as a blend containing 50% of terpolymer to which PA grafts are attached, terpolymer, terpolymer having only one graft and a little amine-terminated PA-6.
TABLE 1 Temperature Stress Elongation Composition Content ° C. kPa (%) Time EVATANE 100/0 120 25 Failure 36 s 28.05 100/0 100 25 Failure 70 s 100/0 80 25 Failure 2 min. 30 70/30 120 25 Failure 120 s 70/30 100 25 Failure 4 min. 30 70/30 80 25 30% >20 min. 50/50 80 25 10% >20 min. LOTRYL 100/0 120 25 Failure 60 s 30 BA 02 100/0 100 25 Failure 90 s 100/0 80 25 225% >20 min. 80/20 100 25 Failure 4 min. 80/20 80 25 50% >20 min. 70/30 120 25 80% >20 min. 70/30 100 25 70% >20 min. 70/30 80 25 15% >20 min. 50/50 120 100 30% >20 min.
Example 5
[0116] I) Characteristics of the Products Used
[0117] 1.1) Polyolefin backbone comprising maleic anhydride. The LOTADER® used for synthesizing the PA-grafted LOTADER was an ethylene/acrylic ester/maleic anhydride terpolymer whose characteristics were:
Theoretical Theoretical Theoretical Melting Name of the % of MAH % of BA MFI Density point product by mass by mass (2.16 kg/190° C.) (g/cm 3 ) (° C.) LOTADER 3410 3.3 to 3.5 37 3 to 6 0.9 95
[0118] 1.2) Characteristics of the amine-terminated polyamide oligomer: the oligomer used was a mono-NH 2 -terminated nylon-6 whose formula is:
Molecular mass Mono-NH 2 PA-6 2445
[0119] 1.3) Characteristics of the flexible polyolefin (LOTRYL®) The LOTRYL® used was an ethylene/butyl acrylate copolymer whose characteristics are:
Theoretical Theoretical Melting Name of the % of BA MFI Density point product by mass (2.16 kg/190° C.) (g/cm 3 ) (° C.) LOTRYL 30 BA 02 30 2 0.93 78
[0120] II) Experimental Part:
[0121] A) Two-step process: the attachment of the amine-terminated polyamide to the backbone was firstly carried out and then the polymer was diluted in the flexible polyolefin.
[0122] A1) Step of synthesizing the mono-NH 2 -terminated-PA-grafted LOTADER (attachment of the amine-terminated polyamide to the backbone). Attachment is carried out in a Leistritz extruder under the following conditions (by weight):
[0123] 80% LOTADER® 3410 and 20% of mono-NH 2 -terminated PA-6 were dry-blended and introduced into the extruder:
Temperature profile of zones 1 to 9 200-210-220-220-220-210-200-180-180° C. Screw speed 75 rpm Output 10 kg/h
[0124] A2) Step of diluting the mono-NH 2 -terminated-PA-grafted LOTADER in the LOTRYL®.
[0125] The dilution in the LOTRYL 30BA02 was carried out in a Leistritz extruder at 220° C.; 50 parts by weight of the product obtained in step A1 and 50 parts of LOTRYL® were used.
[0126] B) One-step process: the amine-terminated polyamide was attached to the backbone and simultaneously diluted in the flexible polyolefin in the extruder. The grafting and the diluting were carried out at the same time in the Leistritz extruder under the following conditions (by weight):
[0127] 40% of LOTADER® 3410, 10% of mono-NH 2 -terminated PA-6 and 50% of LOTRYL® 30BA02 were dry-blended and compounded:
Temperature profile of zones 1 to 9 200-210-220-220-220-210-200-180-180° C. Screw speed 75 rpm Output 10 kg/h
[0128] III) Evaluation of the Thermomechanical Properties of the Compounds: Comparison Between One-Step and Two-Step Compounds.
[0129] A) Thermomechanical properties of the compounds: creep resistance (internal method).
[0130] This property was evaluated by measuring the creep resistance at 100° C. and 120° C. under various loads. IFC (Institut Francais du Caoutchouc [French Rubber Institute]) test pieces were cut from plaques 2 mm in thickness produced by compression-molding in an Enerpac® press. The PA-grafted LOTADER plaques and the diluted products were produced at 240° C. The test piece had to withstand a load of 1 bar at 100° C. and 0.5 bar at 120° C. for at least 20 minutes.
[0131] B) Mechanical properties of the compounds: the mechanical properties were evaluated by measuring the tensile strength and elongation at break (ISO 527 dumbbells; pull rate 100 mm/minute).
[0132] The results are given in Table 2 below.
TABLE 2 Creep at Tensile strength 100° C. under Creep at 120° C., Creep at 120° C. and elongation at Product 100 kPa under 50 kPa under 100 kPa break LOTADER Creep at Creep at 70 s Creep 10 MPa 3410 2 min. Under 25 kPa 700% Under 25 kPa LOTRYL Creep at Creep at 60 s Creep 6 MPa 30BA02 90 s Under 25 kPa 850% Under 25 kPa Obtained in 20 min., 20 min., 20 min., 10.2 +/− 0.6 MPa two steps 30% 15% elongation 30% elongation 501 +/− 20% elongation Obtained in 20 min., 20 min., 20 min., 11.0 +/− 1.1 MPa one step 25% 20% elongation 39% elongation 541 +/− 37% elongation
[0133] IV) Results of the Morphological Evaluation.
[0134] Ultrathin sections were cut at −100° C. and then treated in a 2% aqueous phosphotungstic acid solution for 30 minutes at 60° C. before being examined by transmission electron microscopy. The difference between the products obtained in one step and two steps is small: in both cases, a homogeneous dispersion of the LOTADER containing the polyamide grafts was obtained, the one-step process resulting in a more visible structuration of the latter.
Example 6
[0135] Adhesive.
[0136] The following products were used:
[0137] LOTADER® 7500, an ethylene/ethyl acrylate/maleic anhydride terpolymer:
[0138] Properties of LOTADER 7500:
% mass MFI a) Melt- of MAH % mass (melt Shore A ing (maleic of ethyl flow hard- point anhydride) acrylate index) M n M w M w /M n ness (° C.) 2.9 17.5 70 8000 50000 6.25 82 83
[0139] PA-6/11-g-LOTADER: this is the LOTADER 7500 grafted with 20% of mono-NH 2 -terminated 6/11 copolyamide produced by extrusion in a Leistritz extruder. The 6/11 copolyamide had a 55/45 (caprolactam/11-amino-undecanoic) composition, with an M n of 3200 g/mol, and is mono-NH 2 -terminated.
[0140] Properties of LOTADER 7500 grafted with PA-6/11 (6/11-7500):
Tensile Elongation % mass strength TS at break EB Melting point of PA-6/11 MFI a) (MPa) (%) (° C.) 20 9 13 400 83,151
[0141] The two products were cryogenically ground.
[0142] Tests were carried out on a dusting apparatus.
[0143] Three types of backing were tested:
[0144] PP carpet on aluminum foil with polyester reinforcement;
[0145] gray nonwoven on PE foam;
[0146] gray nonwoven on white felt.
[0147] The PP carpet on aluminum foil was chosen inter alia for its thermal resistance so as to be able to carry out thermal resistance tests at 120° C.
[0148] The application weight was fixed at 20 g/m 3 and the temperature of the fixing press was varied, namely 100, 120, 140, 160, 180 and 200° C. A test with steam bonding was also carried out.
[0149] In the following tables, the tests carried out are listed. The adhesion is assessed qualitatively (the symbol − indicates a poor result, the symbol + indicates a good result, the symbol ++ indicates a better result, etc.).
[0150] Bonding: PP carpet on aluminum foil with polyester reinforcement
LOTADER 7500 Press LOTADER grafted with 15 s/0.35 bar 7500 6/11 coPA 100° C. ++ 120° C. ++ 140° C. ++ + Thermal resistance Delamination No (120° C.) after 9 min delamination
[0151] Bonding: Gray nonwoven on PE foam
LOTADER 7500 Press LOTADER grafted with 15 s/0.35 bar 7500 6/11 coPA 100° C. − 120° C. − 140° C. ++ +
[0152] Bonding: Gray nonwoven on white felt
LOTADER 7500 LOTADER grafted with Press 15 s/0.35 bar 7500 6/11 coPA 100° C. + + 120° C. + + − 140° C. + + + 160° C. + + 180° C. + + 200° C. + +
Example 7
[0153] Tarpaulins
[0154] I—Characteristics of the Products Used:
[0155] I.1—Characteristics of the LOTADER Based Used for the Grafting:
[0156] This is an ethylene/butyl acrylate/maleic anhydride terpolymer containing 20% by weight of butyl acrylate, the characteristics of which are:
Theoretical Measured Measured Measured Measured Theoretical MFI MFI MFI MFI MFI Melting Name of the % of MAH (190° C./ (190° C./ (190° C./ (230° C./ (230° C./ Density point product by mass 2.16 kg) 2.16 kg) 5 kg) 2.16 kg) 5 kg) (g/cm 3 ) (° C.) M n LOTADER 3410 3.1 5 6.8 25.6 18.57 61.5 0.940 95 23000 (MFI is the Melt Flow Index)
[0157] I.2—Characteristics of the Oligomer Used:
[0158] The oligomer used was a mono-NH 2 -terminated nylon-6 of expanded formula:
[0159] This prepolymer had a molecular mass of 2500 g/mol.
[0160] I.3—Characteristics of the LOTRYL Polymers Used for Diluting the PA-Grafted LOTADER Polymers:
[0161] These are ethylene/methyl acrylate or ethylene/butyl acrylate copolymers, the characteristics of which are:
Theoretical Melting Name of % of MA or Theoretical MFI Measured MFI Measured MFI Density point product BA by mass (190° C./2.16 kg) (230° C./2.16 kg) (230° C./5 kg) (g/cm 3 ) (° C.) LOTRYL 18% MA 2 — — 87 18MA 02 LOTRYL 30% BA 2 4.8 14.8 0.930 78 30MA 02 LOTRYL 17% BA 7 17BA 02
[0162] II—Results
[0163] II.1—Preparation of the Products
[0164] II.1.1—Operating Method (General Extrusion Conditions):
[0165] The extruder used to manufacture the grafts and to make the dilutions was a co-rotating twin-screw Leistritz extruder, model LSM 30.34.
[0166] Extrusion Conditions:
[0167] screw profile: G01;
[0168] water on barrel, venting in zone 7 and water cooling;
[0169] total throughput: 15 to 18 kg/h;
[0170] screw speed: 100 to 125 rpm;
[0171] Separate introduction of the reactants (one for the PA-6 powder and one for the granulated blend(s));
[0172] The temperature profiles used were:
Profile Z1 Z2 Z3 Z4 Z5 Z6 Z7 Z8 Z9 Other 200° C. 210° C. 230° C. 240° C. 240° C. 220° C. 210° C. 200° C. 180° C. examples Examples 200° C. 220° C. 240° C. 240° C. 240° C. 240° C. 220° C. 200° C. 180° C. with PA- grafted LOTADER
[0173] The extruder was conditioned for 5 minutes without incident. Sampling took place thereafter;
[0174] The final packaging of the products was done in sealed aluminum bags labeled after treatment in a vacuum oven overnight at 70° C.
[0175] II.1.2—Results of the Evaluation of the Compounds:
[0176] Mechanical properties of the materials on compression-molded plaques.
[0177] In the table below, 3410-6/denotes the PA-6-grafted LOTADER 3410.
3410-6/ 3410-6/ 3410-6/ 30BA 02 30BA 02 18MA 02 in 30/70 in 50/50 in 50/50 PP/ proportions proportions proportions PVC EDPM 30BA02 17BA07 18MA02 (weight) (weight) (weight) 3410-6 Tensile strength 16.0 13.7 6 13 15 8.2 10.2 14.0 16.5 (MPa) Elongation at 250 590 850 800 700 520 500 620 460 break (%) Flexural 20 46 1) 9 40 2) 50 2) 29 1) 44 1) 91 1) modulus (MPa) Shore A 75 n.m. 75 85 90 93 95 hardness Shore D 25 n.m. 33 25 28 30 37 39 hardness Density (g/cm 3 ) n.m. 0.93 0.94 0.94 0.971 MFI (230° C./ 60 n.m. 4.8 n.m. n.m. 5.0 3.9 4.0 1.5 2.16 kg) Melting point 78 91 87 (° C.) MFI (230° C./ n.m. n.m. 14.8 n.m. n.m. 21 19 20 10 5 kg)
[0178] Thermomechanical Properties of the Materials Measured on Compression-Molded or Injection-Molded Plaques
[0179] Compression-Molded Plaques
Creep elongation Creep elongation Creep elongation (100° C./0.25 bar) (120° C./0.5 bar) (140° C./0.5 bar) Product (%) (%) (%) PP/EDPM 0 0 ∞ PVC 20 ∞ 17BA 07 ∞ ∞ ∞ 18MA 02 ∞ ∞ ∞ 30BA 02 ∞ ∞ ∞ 3410- 70 ∞ ∞ 6/30BA 02 30/70 3410- 5 15 25 6/30BA 02 50/50 3410- 5 10 35 6/18BA 02 50/50 3410-6 0 0 3
[0180] The elongation is measured after 15 minutes.
[0181] Comparison of the Thermal Resistance with that of PVC/PP/EPDM:
[0182] The following figures show the elastic modulus as a function of temperature for the 50/50 mixtures of LOTRYL 30BA 02 and PA-grafted LOTADER 3410, for PVC and for PP/EPDM: it may be seen that, above 140° C., the storage modulus of the 50/50 blends of LOTRYL 30BA 02 and PA-grafted LOTADER 3410 is higher than that of the PVC and PP/EPDM products. In addition, examining the loss tangent plotted as a function of temperature shows that the cold properties of the 50/50 blends of LOTRYL 30BA 02 and PA-grafted LOTADER 3410 are higher than the other products, PVC and PP/EPDM.
[0183] II.2 Preparation and Evaluation of Tarpaulins
[0184] The coating was carried out on a SAMAFOR® 4EX. Several backings were used: PET mesh, PP nonwoven and PET woven. The drawability test showed that the product is extrudable up to 100 m/min. 2×100 g/m 2 sheets were produced at 30 m/min.
[0185] The processing and the adhesion of the 50/50 blends of LOTRYL 30BA 02 and PA-grafted LOTADER 3410 are comparable to LOTRYL.
Example 8
[0186] Calendering
[0187] The 50/50 blend of LOTRYL 30BA 02 and PA-grafted LOTADER 3410 of the previous example was used. Its characteristics were:
Tensile strength in MPa 8.6 Elongation at break in % 630 Shore A hardness 91 Shore D hardness 35 MFI (230° C./2.16 kg) 4 Creep resistance at 120° C. >15 min. with an under a load of 0.5 bar elongation of 15% E′ (120° C.) in MPa 1.08 E′ (25° C.) in MPa Density in g/cm 3 0.97
[0188] 3—Calendering Tests
[0189] The calendering tests were carried out at temperatures between 120 and 200° C.
Material homo- geneity Appearance of Temperature Speed of the (trans- the calendered of the rolls rolls parency) sheet Comments 120° C. Front: 20 rpm poor Shark skin Rear: 20 rpm 140 Front: 20 rpm average idem Rear: 20 rpm 160 Front: 20 rpm good Beautiful Rear: 20 rpm appearance 180 Front: 20 rpm good Slight bulk Rear: 20 rpm yellowing 200 Front: 20 rpm good Bulk yellowing Product Rear: 20 rpm sticks to the metal (rollers and blades)
[0190] It may be seen that between 120 and 140° C. the product does not have a beautiful appearance and that it remains opaque, a sign of poor homogeneity of the blend; between 180 and 200° C. the product yellows and sticks to the metal.
[0191] The best working temperature for this type of polymer is about 160° C., the material not oxidizing and not adhering to the rolls of the calender.
Example 9
[0192] Cables
[0193] The material used was LOTADER 3410 either grafted with a mono-NH 2 -terminated PA-6, as in Example 7, or grafted with a 6/12 coPA having the following characteristics:
PA-6/PA-12 Melting point weight ratio (° C.) Mono-NH 2 — 40/60 133 terminated 6/12 coPA
[0194] Characteristics of the Other Constituents
Melt flow Melting index MFl Elongation point (190° C./ Tensile strength at break Name (° C.) 2.16 kg) in MPa in % EVA 2803 75 3-4.5 33 700-1000 (ethylene/vinyl acetate copolymer) LOTRYL 3OBA 02 78 2 6 850 LOTADER 3200
[0195] LOTADER 3200 is a terpolymer containing 9% by weight of butyl acrylate and 2% by weight of maleic anhydride.
[0196] Characteristics of the Filler Used
[0197] The filler used was MAGNIFIN H10 magnesium hydroxide Mg(OH) 2 . This filler has a high thermal stability and can be used to 340° C., water being liberated at a temperature of 350° C.
[0198] II.6) Compositions for the Tests (Theoretical Values)
Control Product name formulation Test 1 Test 2 Test 3 EVA 28-03 16.65% 16.2 LOTADER 3200 11.0 CLEARPLEX 9.1 8.1 11.1 (VLDPE) PA-6-grafted 10.7 10.7 12 LOTADER PA-6/12-grafted LOTADER LOTRYL 3OBA 24.9 28 02 MAGNIFIN H10 63 56.1 61.7 60 (Mg(OH) 2 ) SANTONOX R 0.25 0.2 IRGANOX B 225 0.3
[0199] Evaluation of the (Thermo)Mechanical Properties of the Compounds:
[0200] A) Thermomechanical Properties of the Compounds
[0201] Creep resistance (internal method).
[0202] This property was evaluated by measuring the creep resistance at 180° C. and 200° C. under various loads. IFC (Institut Francaise du Caoutchouc [French Rubber Institute]) test samples were cut from plaques 2 mm in thickness produced by calendering and compression-molding. The test specimen must withstand a load for at least 20 minutes.
Control Test 1 Test 2 Test 3 Test 4 Test 5 Compression 170° C. 250° C. 250° C. 170° C. 250° C. 250° C. temperature (° C.)
[0203] B) Mechanical Properties of the Compounds
[0204] The mechanical properties were evaluated by measuring the tensile strength and the elongation at break (ISO 527 dumbbells; pull rate 100 mm/min).
[0205] C) 600° C. Ash Content
[0206] The ash contents were measured at the LEM (Materials Testing Laboratory) on a TXG CEM 300 apparatus.
[0207] III) Results of the Evaluations of the Compounds
[0208] III.1) Mechanical and Thermomechanical Properties
Expected Tensile 180° C. 180° C. filler strength in Elongation at creep at creep at content MPa in break in % 0.5 bar 1 bar Control 60 13.6 143 Broke at Broke at 45 s 30 s Test 1 60 10.5 52.7 5% elong. 5% 20 min. elong. 20 min. Test 2 60 12.5 150 5% elong. Broke at >20 min. 4 min. Test 3 60 10.4 40 5% elong. Broke at >20 min. 5.
Example 10
[0209] Slush Molding
[0210] LOTADER 7500 grafted with 20% mono-NH 2 -terminated PA-11 of M n =2500 g/mol was used.
[0211] LOTRYL 35BA 40 is an ethylene/butyl acrylate copolymer containing 35% by weight of butyl acrylate and having an MFI of 40 g/10 min (190° C./2.16 kg).
[0212] The products were cryogenically ground after extrusion.
Control Test 1 Test 2 Test 3 Test 4 Composition by PVC 50% 7500-11 75% 7500-11 50% 7500-11 100% weight 35% 30BA 02 25% 35BA 50% 35BA 40 7500-11 15% 35BA 40 40 Tensile strength 16 9.2 6.8 4.5 10 (MPa) Elongation at break 250 500 250 225 300 (%) Shore A hardness <85 84 89 82 89 Shore D hardness <25 25 29 24 35 MFI at 230° C./ >40 25 61 69 70 2.16 kg (g/10 min) Creep at 120° C./ 20 1 0 6 0 0.5 bar after 15 min (%)
[0213] The products were manufactured by extrusion in a Leistritz® machine;
[0214] 7500-11 denotes LOTADER 7500 grafted with PA-11;
[0215] 30BA 02 and 35BA 40 denote LOTRYL ethylene/alkyl acrylate copolymers. | The invention concerns a mixture comprising by weight, the total being 100%, 1 to 100% of a polyamide block copolymer consisting of a basic polyolefin chain and on an average at least a polyamide graft wherein: the grafts are fixed to the basic chain by the radicals of an unsaturated monomer (X) having a function capable of reacting with a polyamide with amine terminal, the radicals of the unsaturated monomer (X) are fixed to the basic chain by grafting or copolymerisation from its double bond; 99 to 0% of a flexible polyolefin with elastic modulus in flexure less than 150 MPa at 23° C. and having a crystalline melting point ranging between 60° C. and 100° C. Said mixtures are useful for making films, tanks, geomembrane protective fabrics produced by extrusion, products obtained by calendering, thermocladding/forming, protective films for electric cables and skins using slush moulding technique. | 2 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to the removal of grips from handles or shafts. More particularly, the present invention relates to an apparatus and method for facilitating the removal of a golf grip from its associated golf club shaft.
2. Description of the Prior Art
Hand grips are used for a variety of devices, including sporting goods equipment. Used and/or worn grips, particularly in the golf field, present problems during the removal process. As basic components, a golf club includes a club head, a shaft and a grip. A golf shaft is generally a hollow tube that is tapered from its butt end to its tip. The club head is attached to the tapered tip of the golf shaft and provides the ball striking surface. A golf grip is attached to the "fat" butt end of the club that exhibits a more or less constant diameter and provides the handle for the golfer's hands.
A grip is generally a rubber sheath that fits around the butt end of the shaft. To attach a grip to the shaft of the golf club, the shaft is usually first wrapped with double-sided tape over a length of the shaft equivalent to the length of the grip. A solvent is then used to dissolve and lubricate the adhesive on the outside of the double-sided tape and lubricate the internal portion of the grip. Finally, the grip is slid into place over the double-sided tape at the butt end of the club. Once the solvent dries and the adhesive sets again, the grip should not move so that the position of the grip on the shaft remains constant.
When one desires to remove a grip from a golf club, e.g., to regrip the golf club, the old grip must be separated from the double-sided tape. One technique for removing a grip is to cut a longitudinal slit in the grip with the tip of a knife blade, razor blade or other cutting utensil (referred to herein as the "slit technique"). Once the grip has been cut along its length, the grip may be peeled away from the double-sided tape. The double-sided tape may then be removed to expose the original, ungripped shaft.
A different technique for removing a grip is to strip a section of the grip off the shaft using the broad face of a horizontally positioned razor blade (referred to herein as the "strip technique"). Once the strip is removed, the rest of grip may be pulled away from the double-sided tape.
If the shaft is made of some sort of fibre, as opposed to steel, and penetration of the blade into the grip during a removal process is too deep, the cutting tool may score and thereby damage the underlying shaft of the golf club. Particularly, with graphite fibre shafts, this scoring may lead to subsequent, undesirable fractures of the shaft during use. Such a fracture necessarily leads to an expensive replacement of the golf club shaft.
An additional disadvantage of most previously known devices is that they use nonstationary or hand-held blades, which exposes the person removing the grip to the danger of minor cuts to severe lacerations if a blade or club slips during cutting.
One prior device provides a horizontally positioned razor blade that is adapted to the strip technique. In use, this prior art device is held in place by a vise, while the grip of a club is pulled against the broad face of the razor blade to strip a section of the grip down the full length of the grip. However, it is believed that this device requires greater force to effect the cut (than is used for the slit technique) because the blade must essentially cut through more of the grip to actually remove a strip of finite width. In turn, requirement of greater force increases the possibility that the application of such force could bend, break, or otherwise harm a club. It is therefore desirable to provide a device that requires less effort in handling.
In turn, the fact that the blade encounters more of the grip increases the likelihood that the blade might become dull and increases the need to repeatedly sharpen or replace the blade to maintain performance of the device. Absent such measures, such previously known devices might quickly deteriorate in use.
By the same token, while there exist devices that utilize the slit technique, it is believed that such devices fail to provide a means to maintain a constant orientation of the blade relative to the grip and shaft. The provision of such consistent orientation is desirable to enhance cutting efficiency and consistency. In turn, such efficiency and consistency is desirable both for providing consistent quality of grip replacement and for minimizing club damage or injury to those performing the grip replacement.
Thus, a device is needed to facilitate the removal of a grip from the shaft of a golf club without the associated problems of damage to the shaft or injury to the operator.
SUMMARY OF THE INVENTION
The present invention addresses the problems discussed above by providing a relatively simple and effective grip removing device that facilitates the removal of golf grips. The grip removing device includes a mountable base that is adapted to be secured to a work surface. A cutting member is secured to the mountable base, and is positioned such that the cutting member has a cutting surface that extends upwardly and is substantially perpendicularly disposed to the golf club in use. The cutting member may comprise a blade having a grip-engaging hook or lip. Specifically, it may have a noncutting top surface and a lateral cutting surface that are configured to define a guide-tip for receiving the lip of a grip in use. The cutting member may further be positioned to be in an offset alignment with the center-line of the golf shaft in use so that the blade will not be positioned exactly perpendicularly to the grip (and shaft) in use, thereby lessening the possibility that the blade will deeply score a golf shaft in use.
The grip removing device may further include an alignment member secured to the base and adapted to receive and guide a golf club shaft in a selected path relative to the cutting member in use. The alignment member may be movably mounted to the back portion of the mountable base in order to provide alignment and guidance for a golf shaft when the invention is used. In a preferred embodiment, the alignment member comprises a cylindrical, club-receiving sheath appropriately sized to receive and guide a golf shaft in use. This sheath may include a blade receiving slit, if the sheath is adapted to extend over the blade. Further, the cylindrical, club-receiving sheath may be securable to a work surface to provide constant alignment for use of the invention.
The present invention also contemplates a method for facilitating the removal of a grip from a golf club having a butt end including a grip coupled to a shaft. The method includes the steps of inserting a butt end of a golf club into a grip receiving portion of a grip removing device; engaging the grip with a substantially perpendicularly oriented cutting member of said grip removing device; and pulling the butt end of the golf club from the grip receiving end of the grip removing device to slit the grip along a longitudinal line to accommodate removal of the grip from the shaft. In a further embodiment, the grip removing device includes a movably mounted alignment member, and the method is characterized in the inserting step by inserting the butt end of the golf club into such a alignment member and moving the alignment member into a cutting position to position the butt end of the club proximate the cutting member to engage the grip with the cutting member.
Accordingly, the present invention provides a device that enables the use of the slit technique to remove a grip while also providing a means to consistently align a golf club in the device for consistent performance and operation. Because the cutting member cuts only a single groove or slit in the grip (rather than an entire section from the grip) the resistance to cutting is less, and it is believed the life of the blade will be enhanced over that encountered for blades used in devices using the strip technique.
These advantages and features of the present invention may be better understood by reference to the following description and appended drawings, which form a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
It should be noted that the appended drawings illustrate only particular embodiments of the invention and are, therefore, not to be considered limiting of its scope, for the invention may admit to other effective embodiments.
FIG. 1 is a top, right perspective view of a grip removing device according to the present invention with the sheath in a raised position.
FIG. 2 is a top, right perspective view of a grip removing device according to the present invention with the sheath in a lowered position.
FIG. 3 is a top, right perspective view of the grip receiving end of a grip removing device according to the present invention, with the sheath in a lowered position.
FIG. 4 is a front plan view of a grip receiving end of a grip removing device according to the present invention with the sheath in a lowered position.
FIG. 5 is a side plan view of a blade cutting member for a grip removing device according to the present invention.
DETAILED DESCRIPTION
Referring first to FIG. 1, there is shown a top, right perspective view of a grip removing device 100 according to the present invention. The grip removing device 100 generally includes a mountable base 102, a cutting member or blade 104, and an alignment member 108. The base 102 may have any of a number of configurations adapted to support cutting member 104 in a selected orientation, while providing a stable, secure base for the cutting member 104. The base 102 is further adapted to be secured or mounted to a work surface such as a table, work bench or similar surface by suitable fasteners, such as the hex-head bolts 112 shown in FIG. 1, or removable clamps (not shown) if transportability of the device is desired. By so securing the grip removing device 100 to a work surface, the user may eliminate the need (that exists with many devices) for holding the cutting member, and gain the advantage of using a work surface to provide the opposing force on the cutting member 104.
The grip removing device 100 further includes a cutting member 104, that is removably secured to the base 102 to provide a selected alignment and orientation for the cutting member 104. The cutting member 104 may be secured to the base 102 in a number of suitable manners that will be apparent to those of skill in the art from the present disclosure. In the illustrated embodiment, the base 102 comprises channel-shaped member, as best seen in FIG. 1 and FIG. 2. The base further includes a receiving plate or fixing plate 106 that is sized complementary to the inner dimensions of the channel of the base 102 such that the receiving plate 106 is snugly received within the channel. The receiving plate 106 has a receiving slit having a position and configuration that is adapted to provide the desired position and orientation for the cutting member 104 when the cutting member 104 is positioned within the slit of the receiving plate 106.
The cutting member 104, receiving plate 106 and base 102 further have an aligned aperture passing there through such that the three members may be held together by use of a suitable fastener, such as retaining screw 114, as best shown in FIG. 1. In this manner, the cutting member 104 may be securely fixed so that the cutting member 104 has the desired angle of orientation and alignment for use of the grip removing device 100 of the present invention.
In the preferred embodiment, the cutting member 104 is positioned such that the cutting surface 132 (see, e.g., FIG. 5) of the cutting member 104 is oriented to be "substantially perpendicular" to a golf club shaft in use. By "substantially perpendicular," it is meant (and is important) that the cutting surface 132 of the cutting member 104 is positioned such that when in use, it penetrates into the grip of such a golf club substantially to the shaft of the golf club to cut a slit in the grip, but does not cut totally through the grip to remove a portion of the grip during the cutting action. This limited cutting depth is believed to minimize the required force for cutting and improve overall cutting efficiency. As shown in FIG. 1 and FIG. 4, in the preferred embodiment, the cutting member 104 is a blade that is vertically disposed such that the cutting member 104 would be perpendicular to the golf club shaft if the centerline of the shaft were aligned with the blade 104 in use. As is described in greater detail below, however, in the preferred embodiment and preferred method of the present invention, the grip removal device 100 is configured so that the cutting member 104 is not positioned in alignment with the centerline of the shaft of the golf club in use, but rather is slightly offset in order to minimize the possibility for the cutting member 104 to score or damage the golf club shaft during the slitting operation.
The present invention further includes an alignment member 108 for providing guidance and alignment of a golf club shaft when the grip removing device 100 is utilized. The alignment member 108 of the grip removing device 100 may have many different configurations so long as the alignment member 108 is adapted to align a golf club shaft in the desired orientation relative to the cutting member 104 to effectively slit a golf club grip 120 in use.
In the illustrated embodiment, the alignment member 108 comprises a substantially cylindrical, grip-receiving sheath that is rotatably mounted to the base 102. The alignment member 108 is aligned with the cutting surface of the cutting member 104 so that movement of a golf club shaft within the sheath 108 causes movement of the golf grip along the cutting member 104 to effect the desired slitting motion. The sheath 108 may be connected to the base 102 by any of the number of means that will be apparent to those of ordinary skill in the art in view of the present disclosure. In the illustrated embodiment, the base 102 includes an upwardly extending channel member. The channel member and the sheath 108 are complementarily sized so that the sheath 108 fits within the channel member as shown in FIG. 1. The sheath 108 is then rotatably connected to the channel member of the base 102 by pin 116 so that the sheath 108 may be rotated into and out of a cutting position as shown in FIG. 1 and FIG. 2.
Additionally, the alignment member 108 has a length suitable to provide alignment of a golf club shaft for the full cutting operation. In a further aspect, the alignment member 108 may extend past the cutting member 104 to insure such alignment of a club in use. The alignment member 108 therefore includes a cutting member receiving slit 110 to accommodate passage of the cutting member 104 into the alignment member 108 to engage the golf club grip 120 in use. This configuration provides greater alignment and enhanced safety since the cutting member 104 remains covered for the cutting operation.
The base 102 and the alignment member 108 may be comprised of any of the number of suitable materials that will be known to those of skill in the art in view of the present disclosure. For example, the alignment member 108 and the base 102 may be comprised of machined aluminum. It will be appreciated by those of skill in the art, however, that other materials may be utilized so long as the requisite strength and functionality of the device are maintained. Within these parameters, it is believed that the particular material chosen for the grip removing device 100 is not critical.
Referring now to FIG. 5, there is shown a side plan view of an embodiment of a cutting member 104, which is a hooked blade. In this embodiment, the cutting member 104 includes a noncutting top surface 130 and a lateral cutting surface 132. Cutting member 104 also includes a screw receiving hole 134. Additionally, cutting member 104 is generally planar (for insertion into the slit in receiving plate 106), and may be provided with two cutting surfaces 132 (as shown in FIG. 5) so that cutting member 104 may be rotated to use the second cutting member surface when the first becomes dull or damaged. Further, cutting member 104 may be shaped to provide a guide-tip 136 that may be easily fit under the lip 124 formed between a grip 120 and a shaft 122. Top surface 130 may be a noncutting surface to avoid unnecessary damage to shaft 122. Cutting member 104, however, may have a variety of configurations or structures as long as it provides an adequate lateral cutting surface for engaging and slitting a grip in use. For example, cutting member 104 may also be a straight razor-blade cutting member with a triangularly shaped tip, having a lateral cutting edge on one face. Cutting members that may be used are available from Golfsmith International, Inc. under Stock No. 853R (straight cutting members) and Stock No. 8533 (hooked cutting members).
FIG. 4 is a from plan view of a grip receiving end of grip removing device 100. As shown in FIG. 4, base 102 and alignment member 108 may be positioned in vertical alignment along their respective center-lines, as represented by common center-line 140. In one aspect of the present invention, cutting member 104 may be off-set from center-line 140 of base 102 and alignment member 108 such that cutting member 104 receives grip 120 at a position offset from the center-line 143 of shaft 122. This off-set is advantageous because it reduces the potential of damage to shaft 120. The degree of off-set between the cutting member 104 and the center-line 140 of the alignment member 108, the structure of the alignment member 108, the distance to which the cutting member 104 extends above the bottom side wall of the alignment member 108, and the diameter of alignment member 108 may be adjusted so that cutting member 104 engages grip 120 at a variety of different locations relative to center-line 143 of shaft 122 and grip 120.
To add flexibility, cutting member 104 may be adjustably secured to base 102 such that the degree of off-set between cutting member 104 and center-line 140 of alignment member 108 may be adjusted as desired by the user. Accordingly, the golf clubs with differing diameters for the shaft 122 and the grip 120 may easily be accommodated.
As shown in FIG. 4, with respect to a substantially cylindrical sheath alignment member 108, cutting member 104 forces the grip 120 and the shaft 122 of the butt end of a golf club against one side-wall of the substantially cylindrical sheath alignment member 108. The off-set of cutting member 104 from center-line 140 of alignment member 108, as shown in FIG. 4, is relatively small, and the inner diameter of alignment member 108 is larger than the outer diameter of shaft 122 and grip 120. As can be seen in FIG. 4, enlarging the inner diameter of the alignment member 108 would cause the shaft 122 and the grip 120 to be forced further to the side when they engage with the cutting member 104, and center-line 143 of the shaft 122 would be displaced further from the center-line 140 of the alignment member 108. Similarly, modifying the height and position of cutting member 104 will cause the cutting member 104 to engage the grip 120 at differing distances from the center-line 143 of the shaft 122. For example, the alignment member 108 and cutting member 104 may be configured so that cutting member 104 engages grip 120 and shaft 122 at engaging point 142. Line 144 represents a perpendicular line to center-line 140 of shaft 122, and angle 146 is, therefore, 90°. As would be evident to one of skill in the art from this disclosure, further variations on this structure are possible to provide varying degrees of off-set between cutting member 104, center-line 140 of alignment member 108, and center-line 143 of shaft 122 and grip 120 as desired.
The present invention also comprises a method for removing a golf grip from a golf club. Referring again to FIG. 1, FIG. 2, FIG. 3 and FIG. 4, the operation of grip removing device 100 is shown. The operator first inserts the butt end of a golf club into alignment member 108 as shown in FIG. 1. This is the grip receiving end of grip removing device 100. Alignment member 108 may have sufficient length to receive all of grip 120 or may be provided to only receive part of grip 120. Base 102 is preferably of sufficient length to allow grip 120 to easily fit between cutting member 104 and the back end of grip removing device 100.
Once inserted, the golf club is lowered to the mountable base 102 in the alignment member 108, as shown in FIG. 2. Cutting member 104 pushes the butt end of the golf club to the side of alignment member 108, if substantially cylindrical as shown in FIG. 4. The golf club is then pulled from alignment member 108, while applying pressure against cutting member 104, so that the cutting member 104 engages grip 120 as shown in FIG. 2 to cut a longitudinal slit into grip 120. When completed, grip 120 may be peeled off of shaft 122, as shown in FIG. 3. In operation, alignment member 108 stabilizes the golf club, facilitates positioning of the grip 120 with respect to cutting member 104, retains the golf club in relative position with cutting member 104, and protects the operator from cutting member 104. If cutting member 104 includes a guide-tip 136, the guide-tip 136 slips beneath and receives the lip 124 of the grip 120 to initiate the engagement of the grip 120 with the cutting surface 132 of the cutting member 104.
It should be noted that in an alternative embodiment, alignment member 108 may be mounted to a fixed work surface instead of base 102. In this embodiment, the base 102 and cutting member 104 are movably mounted to the alignment member 108. In such an embodiment, the butt end of the golf club is first inserted into alignment member 108. Then the base 102 is lowered and the cutting member 104 positioned so that the cutting member 104 engages the grip 120.
Further modifications and alternative embodiments of this invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be understood that the forms of the invention herein shown and described are to be taken as the presently preferred embodiments. Various changes may be made in the shape, size, and arrangement of parts. For example, equivalent elements or materials may be substituted for those illustrated and described herein, and certain features of the invention may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. | A novel method and apparatus for cutting a slit in the grip of a golf club to facilitate the removal of a golf grip from a golf club is disclosed. The disclosed grip removing device includes a mountable base having a club receiving portion and a back portion; a cutting member secured to the mountable base proximate the club receiving portion of the mountable base; and an alignment member movably secured to the back end of the mountable base. The disclosed method includes inserting a butt end of a golf club into the grip receiving portion of the grip removing device, positioning the cutting member to engage the grip, and pulling the butt end of the golf club from the grip receiving portion of the grip removing device to slit the grip along a longitudinal line to facilitate removal of the grip from the shaft. The inserting step may further include inserting the butt end of the golf club into an alignment member and moving the golf club within the alignment member relative to the base of the grip removing device to position the butt end of the club proximate to the cutting member. | 8 |
CROSS REFERENCES TO RELATED APPLICATIONS
This application is a continuation of my previously filed co-pending application bearing the same title, Ser. No. 894,181, filed Apr. 6, 1978 now U.S. Pat. No. 4,241,517.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the art of drying wet grain, continuously or batchwise, and to the air pollution problem it creates.
2. Description of the Prior Art
The Francis U.S. Pat. No. 3,449,840 and Lambert, Jr. U.S. Pat. Nos. 3,755,917 and 4,085,520 all disclose a grain drying apparatus of the continuous (or batch) rotary sweep type and are all owned by a common assignee, the Clayton & Lambert Manufacturing Company of Buckner, Kentucky 40010. As a continuous drier, the lag side of the sweep continuously deposits wet grain as it rotates, say counter-clockwise (CCW), over a circular perforated floor, to form a circular layer of grain extending clockwise (CW) on the floor from the wet lag side of the sweep to the lead side thereof. This circular layer of grain dries progressively from the wet lag side to the dry lead side of the sweep as hot air is blown upwardly through the layer. As it dries, its thickness decreases; hence, its dry end is much thinner than its wet end. The dry lead side of the sweep continuously retrieves dried grain from the adjacent dry end of the circular layer. The moist or wet hot air, flowing from the entire layer, is contaminated with fugitive dust. It is discharged from the bin into the ambient atmosphere, thereby polluting the atmosphere.
SUMMARY OF THE INVENTION
Objects of the Invention
The principal objects of the present invention are: to reduce the loss of heat passing through the dry grain and flowing into the suction system on the dry lead side of the sweep; to increase the recovery of fugitive dust created within the confines of the sweep as a whole; to reduce the emission of fugitive dust into the ambient atmosphere; and to improve the general design.
Statement of the Invention
The aforesaid Lambert, Jr. U.S. Pat. No. 4,085,520, which adds said anti-pollution system to the prior art grain driers, includes a suction canopy chamber embracing the fugitive dust created along the lead side of the sweep and a duct system leading to a high efficiency cyclone separator for separating and recovering that dust and discharging the clean air into the ambient atmosphere.
I have come to appreciate that, since the depth of the dry end portion of the grain layer decreases more or less progressively as it approaches the point of retrieval, there is, in said Lambert anti-pollution system, a progressive increase in the amount of unused hot air flowing from that progressively thinner layer of grain; hence, I propose to provide the lead side of the sweep with an overflow dam, which compels the grain in the dry end portion of the layer to build up to and remain at a desired thickness and then overflow into the dry grain retrieving or removal means. In this way, the resistance of the dry end portion of the layer to the flow of hot air is increased over what it would otherwise be with a consequent decrease in the amount and temperature of the hot air discharging from that portion and flowing into the suction system.
Moreover, I have found that fugitive dust is also created on the wet lag side of the sweep by the incoming wet grain as it falls toward the floor and that much of this wet-side dust, together with the dust created by the outgoing dry grain discharging into the center well, can be sucked through the suction canopy chamber into the anti-pollution duct system and thus prevented from escaping through the bin atmosphere to the outside ambient atmosphere.
Furthermore, in accordance with my invention, the clean air, discharging from the outlet of the high efficiency cyclone used in the anti-pollution system, may be directed back into the grain drying bin under its perforated floor so that the dust and heat content are once again subject to recapture. Preferably, the cyclone outlet air is recycled into the bin through one of its air heaters. Finally, I improve the design, particularly the inner end support of the rotary sweep.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the accompanying drawing wherein:
FIG. 1 is a top plan view of a grain bin installation embodying the present invention;
FIG. 2 is a partly broken side elevation of FIG. 1;
FIG. 3 is a somewhat schematic top plan view showing the positional relationship of important rotary sweep parts between the outer wall of the bin and the vertical axis thereof;
FIG. 4 is a section taken along line 4--4 of FIG. 3 to show the left or lag and right or lead sides of the sweep;
FIG. 5 is a partly broken vertical section taken along line 5--5 of FIG. 4;
FIG. 6 is a perspective view of the parti-cylindrical cap covering the outermost part of the top of the center cylinder;
FIG. 7 is a fragmentary perspective view of the innermost end of the canopy;
FIG. 8 is a horizontal section through the upper part of the center cylinder, this view, which looks downward, omits the funnel-mouthed grain inlet conduit and the inner ends of the upper and lower grain-handling augers;
FIG. 9 is an enlarged section along line 9--9 of FIG. 2 with the rotary sweep swung 90° CCW from its position in FIG. 2; and
FIG. 10 is a vertically exploded view of the center support means and grain trough.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The structure illustrated comprises: a Lambert-type of anti-pollution grain drying apparatus; and my improvement.
THE LAMBERT APPARATUS
The Lambert apparatus illustrated, which includes a grain drier of the type disclosed in the Francis and Lambert U.S. Pat. Nos. 3,449,840 and 3,775,917, and which also includes the Lambert anti-pollution apparatus of said U.S. Pat. No. 4,085,520, conventionally comprises: a grain bin; grain drying means; wet grain feed means; dry grain discharge means; a rotary sweep; sweep drive means; sweep support means; and Lambert's anti-pollution means.
GRAIN BIN
The grain bin 10 has a bottom plenum chamber 11 under a perforated partition or floor 12 separating the plenum chamber 11 from an upper drying chamber 13, having one or more wall openings (not shown) for discharging the hot moisture-laden air into the ambient atmosphere. The top of the grain bin is covered by a conical roof 14.
GRAIN DRYING MEANS
The grain drying means simply comprises a "hot air" blower 16 mounted to blow atmospheric air through a heater (not shown) into the bottom plenum chamber 11 to establish a continuous flow of hot drying air from the bottom plenum chamber successively through the floor 12, a grain layer on the floor 12, the drying chamber 13 and one or more air discharge openings in the bin wall.
WET GRAIN FEED MEANS
The wet grain feed means includes: an inlet conduit 18, feeding grain to and downwardly through the center of the conical roof 14; a conical wet grain hopper 19, mounted on the interior bin walls to receive the incoming wet grain; and a funnel-mouthed conduit 20 centrally positioned not only to receive wet grain from the bottom of conical hopper 19 but also to feed that grain downwardly along the axis of the bin into the lag side of the rotary sweep. The vertical conduit terminates at its lower end in a horizontal sleeve 21 having an inner closed end and an outwardly projecting outer end.
DRY GRAIN DISCHARGE MEANS
The dry grain discharge means comprises: a stationary trough 22 having an open top positioned adjacent the level of a centrally disposed opening in the bin floor, straight end walls and V-slanted side walls which terminate in a rounded or semicylindrical bottom wall 23; and a conveyor auger or screw 24 extending radially along the rounded bottom 23 of trough 22 and through a conveyor pipe 25 projecting, from an opening in one end wall of the trough, successively through the plenum chamber 11 and an outer wall of the bin to a desired discharge area outside of the bin.
ROTARY SWEEP
The rotary sweep 27 comprises: a rotary cylinder 28 concentric to the vertical axis of the sweep 27 and vertically arranged, at the floor level of the bin, to open downwardly into said V-shaped trough 22 with which it cooperates to form a vertical center well 29; a wet grain distributing conveyor 30 arranged on the lag side of the sweep with its inner end house in sleeve 21; a dry grain retrieving conveyor 31 arranged on the lead side thereof with its inner end housed in choke sleeve 31A; a horizontally elongate vertical partition wall 32 projecting radially from the rotary cylinder 28 to separate the lag side of the sweep from the lead side thereof, and having horizontally offset upper and lower vertically straight portions and a rearwardly declining or slanted vertical mid-portion separating the upper lag-side wet grain distributing conveyor 30 from the lower underlying lead-side dry grain retrieving conveyor 31; and a radially-elongate leveling wall 33, on the lag side of the lag conveyor 30. The cylinder 28 is slotted on its auger side, its slot edges flanged and its slot closed by a shallow U-shaped channel 28A, through which the augers pass.
Rotary sweeps may be arranged to rotate horizontally in sweep fashion in either direction. For the sake of clarity, the sweep illustrated will be referred to throughout this application as moving counter-clockwise (CCW). It receives an incoming stream of wet grain from the wet grain feed means through conduit 20, 21 and drops it on the floor where it piles up, its lag side conveyor 30 distributes that pile of grain radially over the floor, its leveling wall 33 scrapes the distributed grain to maintain the wet end of the circular layer at a desired thickness, and its lead side conveyor 31 moves the dry end of the circular layer inwardly to the center well 29 where it drops into trough 22 of the dry grain discharge means.
A suitable seal 34 is interposed between the round bottom of rotary cylinder 28 and a round hole in a plate placed on the top of the stationary trough 22 to facilitate relative rotation therebetween. The seal 34 doesn't transmit weight.
DRIVE MEANS
The drive means requires only one outside electric motor 36 to drive the dry grain discharge and retrieving augers 24 and 31, the wet grain distributing auger 30 and the rotary sweep 27. To drive the dry grain discharge auger 24, motor 36 is connected to the outer end thereof. To drive the retrieving auger 31, the inner end of the bottom grain discharge auger 24 is connected to the retrieving auger 31 through a vertically spaced pair of intermediate and terminal gear boxes 37 and 38 in the center well. As seen in FIG. 5, the intermediate gear box 37 is located in the upper half of stationary trough 22 while the terminal gear box 38 is located in the lower half of rotary cylinder 28. To drive the distributing auger 30, the terminal gear box 38 is connected by chain 39 to the receiving end of the shaft of auger 30. As seen in FIG. 8, the rotary sweep 27 terminal gear box 38 is connected through chain 40 and tracking shaft 41 to a tracking gear 42 which, when rotated, tracks along stationary ring gear 43 carrying the outer end of the sweep with it.
ROTARY SWEEP SUPPORT MEANS
The rotary sweep is supported at its outer and inner ends. The outer end of the sweep is conventionally supported from rollers on the lower flanges of the stationary ring gear 43 and, since this type of support is in the form of a widely known and used outer roller-bracket assembly, it is not deemed necessary to illustrate or describe it.
The inner end of the Lambert rotary sweep was supported largely by an end-to-end vertical post arrangement, including a stationary lower center post and an upper rotatable post, wherein the center weight was transmitted downwardly through the floor level by a power transmitting shaft. My arrangement, which will be subsequently described, supports and transmits all of the center weight upon and through structural members.
THE ANTI-POLLUTION MEANS
The Lambert anti-pollution means, which is in the form of a suction system for removing and capturing airborne dust coming from the grain in the vicinity of the lead side of the sweep, comprises: a suction chamber 45 arranged on the front side of the partition wall 32 to extend over and above the lead side of the sweep, this suction chamber being composed of a canopy 46 forming the roof of the chamber and a depending curtain 47 extending from the periphery of the canopy's opposite end and front walls downwardly into contact with the underlying grain so as to form the vertical end walls and the front wall of the suction chamber; a pair of orbital conduits 48; a hollow donut casing 49; stationary conduit means 50; blower 51; and an outside dust separator 52.
The orbital conduits 48 connect outlets in the roof of the suction chamber canopy 46 to the interior of the donut casing 49 through an inlet in the casing's bottom wall, which is rotationally mounted on the casing's stationary side walls. The stationary conduit means 50 connects the interior of the donut casing 49, through an opening in a stationary wall thereof, to a blower 51 which suctions air from the suction chamber 45 successively through orbital conduits 48, donut casing 49 and the approaching portion of the conduit means 50 and then blows that air through dust separator 52 where the dust is separated from the air and the cleaned air discharged either to atmosphere or in accordance with my invention.
MY IMPROVEMENT
I propose: to improve the support means; to provide an overflow dam, which is useful in the grain drying apparatus whether or not it is equipped with anti-pollution means; and to improve the anti-pollution means.
IMPROVED SUPPORT MEANS
My support means comprises: a lower stationary integrated support assembly; and an upper rotary integrated support assembly.
The lower assembly includes: a pair of trough supporting base brackets 55, one on each slanted outer side of the trough 22 to bridge the vertical space between that side and the bottom of the bin; a cross-bracket 56 arranged transversely within and mounted on the inner slanted faces of the walls of the trough adjacent the upper ends of the vertical brackets 55; a pair of horizontally-spaced upright brackets 57 mounted on cross-bracket 56, one located on each side of the vertical axis of the grain bin adjacent opposite sides of intermediate gear box 37; and an axis-concentric top plate 58 on the upper end of upright brackets 57, which terminate in the vicinity of the floor level. These stationary parts 55-58 and trough 22 are all rigidly connected together and remain stationary at all times.
The upper rotary assembly, which rests rotationally on the top plate 58, includes: a base plate 60 resting on, and in rotational face-to-face relation to, said top plate 58; an integrated three-sided vertical casing having two opposed side walls 61, 62 located at and connected to the opposite sides of terminal gear box 38; and a third or bight wall 63 extending transversely from one side wall 61 to the other side wall 62 and integrated with both. The side walls extend the full vertical length of cylinder 28. The bight wall 63 projects beyond the upper end of the cylinder 28.
The side walls 61, 62 incline for a short distance outwardly upward from the top of the terminal gear box 38 to widen the space therebetween sufficiently to receive the incoming wet feed sleeve 21 which houses the inner end portion of the distributing auger 31 within rotary cylinder 28. The side walls 61, 62 continue straight upwardly along opposite sides of the upper distributing auger 30 and terminate at or near the top of rotary cylinder 28. Bight wall 63 is in the form of a straight plate vertically arranged within the cylinder 28 between the bin axis and the distributing auger 30 and tracking shaft 41 drive chains 39, 40. It extends upwardly beyond the top of rotary cylinder 28 sufficiently to receive and support the inner end of the tracking shaft 41 and terminates near the bottom level of the funnel-mouth of the wet grain receiving conduit 20.
The inner end of dry auger 31 is supported by the housing of terminal gear box 38. The inner end of wet auger 30 is supported on the bight wall 63 of the integrated casing 61-63. Likewise, the inner end of the tracking shaft 41 is supported on the upper end portion of the bight wall 63. Thus the weight of the apparatus at the inner ends of wet and dry augers 30, 31 and of track shaft 41 is transmitted through the integrated casing 61-63, and associated structural parts, directly to base plates 60 of the upper assembly 60-63, thence to the top plate 58 of the lower assembly 55-58.
The innermost roof truss 65 of the canopy rests upon the upper end of the side walls of the integrated casing 61-63. The rotary cylinder 28 is supported on casing 61-63 by means including a T-bracket 66 connecting two points on the inner wall of the cylinder to the casing through the cross bar of bracket 66 and a 3rd point of the cylinder to the casing through the stem of bracket 66. The casing also supports the funnel-mouthed conduit 20, its sleeve 21 and air-locking choke sleeve 31A of retrieving auger 31. The roof of canopy 46 covers a small portion of the open top of rotary cylinder 28. The remainder of the open top of cylinder 28 is covered by a parti-cylindrical cap 68, i.e. a partial band-shaped or ring-shaped cap, having a closed top and an open bottom. The top of cap 68 is on a level slightly above the uppermost level of canopy 46. Suitable walls (not shown) close any vertical openings resulting from this difference in levels.
OVERFLOW DAM
In accordance with a particular feature of my invention, an overflow dam is arranged on but near the lead side of the lead auger 31 so that, as the rotary sweep 27 sweeps forwardly, it piles up the dry grain in front of it until the dry grain layer thickness exceeds the vertical height of the dam whereupon the dry grain begins to overflow the dam.
The dam is in the form of an elongate metal plate 70 which is slightly longer than the horizontal space between the bin wall and the outer end of the air-locking sleeve 31A of dry auger 31. The plate 70 is supported from the lead side of partition wall 32 by two or more horizontally spaced vertical bars 71 and from the truss system of the canopy 46 by two or more slanted bars 72 which may be lengthened or shortened by turn-buckles 73 or other suitable adjustable means. The overflow feature is useful in continuous batch driers of the type illustrated with or without any anti-pollution means.
IMPROVED ANTI-POLLUTION MEANS
The anti-pollution means is improved, in accordance with my invention, by extending the canopy 46 rearwardly over the lag side of the rotary sweep so as to extend over the lag space 75, which extends on all sides of lag auger 30 between partition wall 32 and leveling wall 33. The lag space 75 communicates with the space extending under the canopy 46 between the roof trusses of the canopy 46. As a consequence, space 75 is also subject to the suction exerted through orbital conduits 48 connecting the suction chamber 45 to the donut casing 49.
Again, in accordance with my invention, the suction chamber 45 is extended to the center well 29 of rotary cylinder 28. Suction from the orbital conduits 48 causes air to flow from the center well 29 of the rotary cylinder 28 upwardly into and obliquely through the suction space 76 lying under the canopy 46 between the innermost truss 65 and the adjacent canopy-supporting member of its truss system.
My invention contemplates either the conventional discharge of the cleaned air from the high efficiency cyclone separator 52 directly into the ambient atmosphere or the unconventional discharge of that air back into the plenum chamber 11 so that its dust and heat contents are once again subject to recapture. The cyclone air outlet is recycled into the plenum chamber 11 through outlet pipe 78, which, preferably, is connected to the intake of one of the hot air blowers 16.
Both the partition wall 32 and the leveling board 33 are conventionally provided with yieldable sealing means (not shown) which scrape the wall of the bin. | An improved grain drying apparatus of the type having a bin with a perforated floor through which hot air is blown upward for grain drying purposes, and a rotary sweep assembly employing a wet grain distributing auger on its lag side and a dried grain retrieving auger on its lead side. One improvement includes an inclined elongate plate forming an overflow dam which extends along the floor on the lead side of the retrieving auger and which is connected to the sweep assembly for rotation therewith so as to build up the thickness of dried grain on the floor ahead of the retrieving auger to increase the resistance of the dried grain to the upward flow of hot air on the lead side such that a greater proportion of hot air will flow upwardly through the floor on the lag side through the wet grain being deposited thereon. Additional features include provision for connecting the suction system of the apparatus to the wet lag side of the bin as well as to a central well into which the retrieving auger deposits dried grain for removal from the bin, and a system for recycling air suctioned from the bin through an external cyclone dust separator back into a plenum chamber under the perforated floor. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This Patent Application is a non-provisional utility application which claims the benefit under 35 U.S.C. 119(e) from U.S. Provisional Patent Application No. 61/937,208 filed on Feb. 7, 2014, entitled, “DETECTING PERIODICITY IN A STREAM OF EVENTS”, the contents and teachings of which are hereby incorporated by reference in their entirety.
BACKGROUND
Systems that support online services, such as internet banking, receive many inputs from computer users interacting with an online service. For example, an online banking service that provides a website to account holders may receive many mouse clicks, or web clicks, or key strokes over the course of a single online banking session. Each of the individual clicks or strokes represents a discrete event. There may be a pattern to a sequence of clicks in a single online banking session, and this pattern may reveal information about the source of the clicks. Specifically, a periodic set of clicks may raise concerns that the source of the clicks is a threat, such as a password cracker program.
Conventional online support services detect periodicity in a sequence of clicks by using algorithms that seek out equally spaced clicks via direct measurement, or by other means such as Fourier transforms.
SUMMARY
Unfortunately, there are deficiencies with the above-described conventional online support services. For example, mouse or web clicks are typically received in a noisy environment. Specifically, mouse or web clicks may travel through a noisy network and meet with random delays. Consequently, algorithms that base a determination of periodicity solely on finding equally spaced clicks lack the robustness needed to find periodic behavior in such an environment.
In contrast to the above-described conventional transaction servers that lack robustness in detecting periodic click streams in a noisy environment, an improved technique involves assigning a periodicity score in a click stream that is indicative of the confidence that the click stream forms a periodic sequence. Along these lines, a server forms an autocorrelation function from clicks in a click stream that contains a series of spikes at time differences between the receive times of each click. The server then convolves this autocorrelation with a jitter kernel that is representative of the temporal noise distribution in the network environment in which the clicks were received. From this convolution, the server may make an estimate of a period T of the click stream. From further analysis, the server may then assign a periodicity score indicative of the confidence level that the click stream is periodic with period T.
Advantageously, the improved techniques may be employed to evaluate periodicity in a sequence of discrete events to robustly determine whether there is an attack occurring, whether there has been a change in a specific routine practice, whether there are patterns in a market activity, or many other situations where the either the presence or absence, or of a change in periodicity of any sequence of discrete events has occurred. With such an arrangement, a sequence of discrete events may be analyzed as to whether or not there is a periodic nature, and a score representing the degree of periodicity may be generated. Knowledge of the periodicity, or lack of periodicity, may be useful in determining the likelihood of an attack being in progress, or for data mining items that may be buried in a noisy data stream. Such a system may provide a more robust determination of periodic threats, or periodic opportunities, than prior art methods. Such an arrangement is more capable of accounting for deviations in periodicity caused by communication variations such as jitter, and thus discovering hidden periodicity.
One embodiment of the improved technique is directed to a method of evaluating a likelihood that a sequence of discrete events displays periodic patterns. The method includes receiving a sequence of discrete events over a time period, for example the clicks made by a client accessing a bank website, and forming a window in time encompassing a temporal extent over which the sequence of discrete events was received. The method may also include generating a first autocorrelation function for the sequence of discrete events. The method may also include generating a convolution of the first autocorrelation function using a jitter kernel to form a smoothed autocorrelation function having a set of peaks. The method may include generating a period value of the first autocorrelation function corresponding to a highest peak in the smoothed autocorrelation function, and generating a likelihood that the sequence of discrete events is periodic based upon the set of peaks.
Other embodiments of the improved techniques are directed to a computer program product which includes a non-transitory computer readable medium storing a set of instructions that, when carried out by a computer, cause the computer to perform the method of evaluating a likelihood that a sequence of discrete events displays periodic patterns.
Another embodiment of the improved techniques is directed to a computing circuit, including a communications interface connected to a network, a memory circuit, a receiving circuit constructed and arranged to evaluate a likelihood that a sequence of discrete events displays periodic patterns.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments of the invention.
FIG. 1 is a diagram of an electronic apparatus for detecting periodicity.
FIG. 2 is a flowchart of steps in a method for detecting periodicity.
FIG. 3 is a diagram showing the time of arrival of a sequence of clicks and an autocorrelation of the time differences between the arrival times of each of the clicks.
FIG. 4 is a diagram showing a convolution of the autocorrelation with a jitter kernel and the resulting smoothed autocorrelation.
FIG. 5 is a diagram showing a convolution of the autocorrelation with a second jitter kernel and the resulting second smoothed autocorrelation.
DETAILED DESCRIPTION
An improved technique involves assigning a periodicity score in a click stream that is indicative of the confidence that the click stream forms a periodic sequence. Along these lines, a server forms an autocorrelation function from clicks in a click stream that contains a series of spikes at time differences between the receive times of each click. The server then convolves this autocorrelation with a jitter kernel that is representative of the temporal noise distribution in the network environment in which the clicks were received. From this convolution, the server may make an estimate of a period T of the click stream. From further analysis, the server may then assign a periodicity score indicative of the confidence level that the click stream is periodic with period T.
The convolution results in a smoothed autocorrelation function having a set of peaks, which provide an estimated period value for a potential pattern. The period is used to estimate a second jitter kernel for another convolution R s ′ and a confidence level.
The method improves evaluation of periodicity for discrete events, such as clicks, and provides a confidence score that indicates the likelihood that a series of events contains a periodic sequence. The discrete events may be characterized by virtue of the events originating from a single internet address, or from a single user, or having some other common feature such as using the same protocol. Thus, a specific discrete event may become part of two or more click streams.
The improved methods may include receiving a sequence of discrete events, such as mouse clicks. The method may include generating an autocorrelation function of the sequence of discrete events, for example fourteen discrete events, where the autocorrelation function may comprise spikes representing pairwise differences in the time received for each individual discrete event. The autocorrelation function may be an arithmetic sum of all the spikes, and spikes that arrive at the measuring location essentially simultaneously may be treated as multiple spikes or as a single spike of proportionally higher strength. In some situations the autocorrelation function may include the differences in time received for a selected portion of all of the spikes received at the measuring location.
The method may include generating a convolution R s between the autocorrelation function and what a jitter kernel to form a smoothed autocorrelation function having a set of peaks. Jitter kernels may be a probability distribution function for a random variable representing a time delay between discrete events in the sequence of discrete events, and may have any of a variety of shapes such as a monotonic function, a Gaussian, a raised cosine window, a Hamming window, a Hanning window, a top hat, or a sin(ωt)/t function. The method may also include generating a period value corresponding to a highest peak in the smoothed autocorrelation function, and generating a likelihood of periodic patterns based upon the set of peaks.
In some arrangements, the shape maybe a Gaussian function having a standard deviation that may be varied as desired to be indicative of the noise environment and to obtain the desired result in smoothing the autocorrelation function. This will produce a smoothed autocorrelation function R s of the discrete events that may capture slightly delayed clicks, for example due to delays in transmission path, and show them to be part of a periodic pattern. The calculated score may be calculated for each individual peak.
In some arrangements, the method includes calculating a period T using the location of the highest peak and compute a second smoothed autocorrelation function using a second jitter kernel, where the width of the second jitter kernel is scaled using the calculated period T, for example a Gaussian having a standard deviation that is a tenth of the period T. In this case, the method also includes generating a final score over the number of discrete events sampled at multiple times.
Each of the click streams is evaluated to determine a relative degree of confidence that the sequence of discrete events in the stream actually does exhibit periodic behavior. The periodicity is evaluated for each individual discrete event based upon a selected number of clicks leading up to that individual click, and a confidence score is determined. The number of clicks evaluated may be any number, for example the fourteen previous clicks, with the preceding clicks being ignored for the calculation.
The selected number of clicks in an evaluation period may be adjusted to accommodate streams having a large variation in signal travel time, which may be known as jitter. For example, remote access attempts made by a denial of service attack where the network route may vary in length due to changes in network traffic loads would have a certain amount of signal jitter.
The above discussion has focused on examples of the use of periodic behavior for determining the presence of potential security threats, but there are other uses as well. Discrete events of various types may have periodic sequences of signal events, or may occur at periodic times. For example, an employer may run a payroll program at the same time each week, or a vertical password guesser may try a new password guess every ten minutes until success is achieved. Some periodic sequences may be benign, and some may indicate an attack. Even in the case where the periodic activity is benign, deviations from the expected benign periodicity may indicate a problem that may indicate a potential issue that needs additional attention.
The examples presented will be applied to a general case where an online business uses an outside vendor to perform the periodicity analysis. The online business could directly analyze the sequence of discrete events in the same computer that received the discrete events, but the information on the time of arrival of the discrete events may be sent to a central location for reasons such as maintaining the bandwidth of the computer handling the business events, or because a central vendor may have computer equipment with greater data handling capability and provide faster analysis results than may be obtained using the online business computer.
FIG. 1 is a diagram of an electronic apparatus 100 for evaluating a likelihood that a sequence of discrete events displays periodic patterns. The apparatus 100 includes a computing circuit 102 having a receiving circuit 104 for receiving a sequence of discrete events. The receiving circuit 104 is communicatively connected by bidirectional communications means 106 to a network 108 . The communications means 106 may be a wired, a wireless, an RF, an IR connection, or any of many other well-known communication means. The network 108 may be the internet, an intranet, the cloud, a token ring, or any of many other well-known networking devices.
The network 108 is communicatively connected to users 112 , 116 , 120 and 124 by bidirectional communications means 110 , 114 , 118 and 122 respectively. Users 112 , 116 , 120 and 124 may represent a bank 112 , a credit card agency 116 , a retail store 120 , a manufacturer 124 , or any person or organization that has a website or electronic devices that use streams of discrete events, such as clicks or keystrokes.
Users may employ the network 108 to send information on the discrete event timing to the computing circuit 102 . As an example, when a bank 112 website receives clicks from a customer using a remote terminal, the bank may want to know if the received sequence of clicks includes a periodic pattern. The periodicity of the pattern of clicks may be used to determine if the customer is a machine rather than a person. This may be useful in preventing fraud or spoofing.
The sequence of clicks sent to the computing circuit 102 by the user ( 112 , 116 , 120 , 124 ) is received by the receiving circuit 104 , and transmitted via bidirectional communications means 126 to a memory circuit 128 for storage, and to a controller circuit 132 via bidirectional communication means 130 . The sequence of clicks may be an actual recording of the clicks as they were received by the user, or it may be a data file that includes the reception time of each of the individual clicks, or other method of transmitting information concerning the sequence of clicks, including arrival times, signal strength, and whether multiple clicks were received in a single time window. A flowchart of the steps of the operation of the computing circuit 102 is found in FIG. 2 , and will be discussed in greater detail below.
The controller 132 transmits the sequence of discrete events via bidirectional communication means 134 to logic circuit 136 , and directs logic circuit 136 to calculate an appropriate window in time that will encompass a time period or temporal extent, over which the sequence of discrete events, in this example mouse clicks, was received by the user. A graphical example of the sequence of discrete events as a function of time is found in the upper half of FIG. 3 , and will be discussed in greater detail below.
The controller 132 may direct the logic circuit 136 to calculate an autocorrelation function of the sequence of discrete events, the autocorrelation function comprising spikes representing pairwise differences in time received for each individual one of the discrete events in the window in time. An autocorrelation function has a form of R(t)=Σ i=1 N−1 Σ j=i+1 N δ(t, t j =t i ) where N is the number of discrete events, t is the time the clicks occur, and δ is the Kroneker delta, where δ(x,y)=1, if x=y, and zero if not.
A graphical example of the autocorrelation function with respect to differences in arrival time is found in the lower half of FIG. 3 , and will be discussed in greater detail below. The autocorrelation function is an arithmetic sum of all of the spikes representing differences in time at which discrete events arrive. In this example the time difference between each of the clicks is shown as being very regular and consequently the autocorrelation is also very regular and shows a clear pattern, however, the describe apparatus is not so limited, and in common situations the arrival time of the discrete events would likely not be so regular due to variations in the electronic pathways that each individual event traverses on the way to the recording location of the user.
The controller 132 may direct the logic circuit 136 to calculate a convolution R s between the autocorrelation function and an estimated jitter kernel to form a smoothed autocorrelation function having a set of peaks. A graphical example of the autocorrelation function of FIG. 3 including a representation of a jitter kernel is found in the upper half of FIG. 4 , and the resulting smoothed autocorrelation function is found in the lower half of FIG. 4 .
It should be noted that the shape of the jitter kernel may be any function, and in particular any function that describes a probability distribution function for a random variable between members of the sequence of discrete events. For example, in some arrangements the jitter kernel takes the form of a Gaussian function of time difference t as follows: K(t)=e −t 2 /2σ 2 /√{square root over (2πσ)}, where σ is the standard deviation. Generally speaking, the jitter kernel may include a width that is indicative of the sort of noise, or travel delays, experienced by the mouse clicks discussed in the given examples. It should be understood that, in performing the convolution of the autocorrelation function with the jitter kernel, logic circuit 136 only considers 4 σ-wide regions which contain at least three peaks.
The controller 132 may direct the logic circuit 136 to calculate an estimated period value, for example the value T shown in FIG. 4 , using a distance to a highest peak in the smoothed autocorrelation function. The highest peak corresponds to the time difference having the most individual discrete event occurrences, and thus is a valuable initial estimate of a possible periodic value. The logic circuit may now calculate a likelihood that the sequence of discrete events is periodic based upon the set of peaks and their locations. The controller 132 may direct the logic circuit 136 to calculate a second jitter kernel, where a width of the second jitter kernel is selected to be proportional to the period T, as found above and as shown in FIG. 3 . As an example calculation, the logic circuit may adjust the width of the initial kernel by a factor of the standard deviation being set to 0.1T, such that the width of the kernel would approximate 40% of the distance between each peak, and thus include spikes having substantial random delays in arrival at the recording location. It should be noted at this point that the second jitter kernel should be more accurate than the initial jitter kernel, which was not based upon the results of the present sequence of discrete events. Thus, the second jitter kernel may be either narrower or wider than the initial jitter kernel, and may result in a smoothed autocorrelation function having either wider or narrower peaks than the first smoothed autocorrelation. The second jitter kernel may be used in a convolution with the autocorrelation function to improve the accuracy of the smoothed autocorrelation.
The controller 132 may direct the logic circuit 136 to calculate a second convolution between the second jitter kernel and the autocorrelation function to form a second smoothed autocorrelation function, as shown in FIG. 5 , where the example shows a Gaussian jitter kernel that is narrower than the first jitter kernel related to the use of the proportionality of the estimated period T for this sequence of discrete events being applied to the width of the jitter kernel.
The controller 132 may direct the logic circuit 136 to calculate a periodicity measure as the sum of the values in the second smoothed autocorrelation evaluated at points T, 2T, 3T, etc. This may be known as the anomaly, or how much the calculated periodicity varies from a perfect period. The anomaly may be represented as an equation, anomaly=Σ n R s ′(nT).
To generate a final score the anomaly value may be normalized by dividing by the number of spike timing differences used in the calculation. In the case of N spikes the normalization factor would equal (N(N−1))/2 if every possible time of arrival difference were to be included. In addition, it may be desirable to convert the normalized anomaly to a final score form more easily understood by users, by setting the final score to be equal to (1−(1−normalized anomaly))×(100) which provides a simple percentage value for use in evaluating whether or not a sequence of discrete events, such as clicks, has a periodic pattern.
In an apparatus 100 , in order to enable what may be known as real time analysis of a sequence of discrete events for periodicity, considerations of the maximum computing speed available in computing circuit 102 may limit the number of discrete events or spikes that may be examined. This is because the number of pairwise time differences that need to be examined, and which enter into the calculation, increases as (N(N−1))/2 as the number of spikes increases. The memory requirements of memory 128 also increase, as well as other limitations of all of the entities shown in FIG. 1 , for example bandwidth in the network 108 . In view of these limitations, the number of discrete events or spikes allowed in a window of time may beneficially be limited to a constant value, for example 14 discrete events. In such a case, each new event could be added to the window, and an oldest event could be removed, to provide a rolling calculation of periodic patterns in real time.
A computer program product which includes a non-transitory computer readable medium storing a set of computer instructions to perform the above described calculations and operations in a computerized device, may include a computer disk, such as disk 140 of FIG. 1 , which may be used to load instructions to a memory location, such as memory 128 of the computing circuit 102 . Many other well-known methods of providing computer instructions to a computing circuit may also be used.
A method for calculating and providing the steps of evaluating a sequence of discrete events for a likelihood of periodic patterns will now be discussed with reference to FIG. 2 . FIG. 2 is a flowchart of steps in a method 200 for detecting periodicity and providing a confidence score that the detected periodic pattern is correct.
The method begins at step 202 and the computing circuit 102 receives the sequence of discrete events to be analyzed at step 204 at the receiving circuit 104 . The sequence is examined by the logic circuit 136 under the control of the controller 132 and an appropriate window in time which contains a selected number of discrete events, for example 14 computer mouse or web clicks, is created at step 206 .
At step 208 the logic circuit 136 generates an autocorrelation function of the sequence of discrete events, and forms a jitter kernel at step 210 , which may represent an estimation of a width of a distribution of random events occurring in the arrival of each of the discrete events, and affecting the timing of the arrival. At step 212 the logic circuit 136 generates a convolution between the initial jitter kernel and the autocorrelation function, and forms a first smoothed autocorrelation function at step 214 .
At step 216 the logic circuit 136 finds a highest peak in the first smoothed autocorrelation function and generates a period value T at step 218 . A level of confidence may be obtained by the logic circuit 136 forming a second jitter kernel at step 222 , where the second kernel is formed with a shape that is calculated to better fit the sequence of discrete events than the first jitter kernel, which was estimated from known average variations. The second jitter kernel may be narrower or wider than the first.
At step 224 the logic circuit 136 sets the second kernel width using the value T generated at step 218 to further refine the relationship of the width of the jitter kernel to the specific sequence of discrete events being examined. For example, the second jitter kernel may be formed having a standard deviation proportional to one tenth of the period T, and maybe determined to allow maximum arrival variation without missing an event.
At step 224 the logic circuit 136 generates a second convolution using the second jitter kernel and the autocorrelation function. The convolution results in a second smoothed autocorrelation function R s ′ at step 228 , and the generation of a confidence score that provides the likelihood that the found periodic pattern with period T is actually a periodic function at step 230 . The level of confidence may be obtained by examining how closely the various multiples of the period T match with the actual peaks of the smoothed autocorrelation function. The method of detecting periodicity in a stream of discrete events ends at step 232 .
FIG. 3 is a diagram showing the time of arrival of a sequence of clicks and an autocorrelation of the time differences between the arrival times of each of the clicks. An upper portion 302 of the graph shows a horizontal time axis 304 with five illustrated clicks 306 , 308 , 310 , 312 and 314 . Each of the clicks is shown as having arrived at a different time, and the time difference between the arrival times are shown as being equal, but the method and apparatus are not limited to regularly spaced arrival times, and normal random statistical variations are expected in real world situations. These normal variations are what the present arrangement is designed to measure and to determine if an actual periodicity exists in the sequence of discrete events, such as the clicks shown, or whether the sequence is simply random.
A lower portion 352 of the graph shows a horizontal time delta axis 354 the results of an autocorrelation function performed with the spikes 306 - 314 , and resulting in groups of spikes 356 , 358 , 360 , 362 and 364 . The autocorrelation represents every pairwise combination of differences in arrival times for the spikes 306 - 314 . The example shows that the evenly spaced spikes 306 - 314 of the upper portion 302 of the graph result in an autocorrelation where the time differences are very bunched up and reflect a strong periodicity, but the normal real world result would likely be much less periodic and chaotic due to random time delays.
FIG. 4 is a diagram showing a convolution of the autocorrelation of FIG. 3 with a jitter kernel and the resulting smoothed autocorrelation. The graph includes an upper portion 402 with a jitter kernel 404 convolved with the five shown groups of spikes 406 , 408 , 410 , 412 and 414 . The jitter kernel is shown as being a Gaussian function, but different window functions, such as raised cosine, Hamming, Hanning, or sin(ωt)/t, may be used as appropriate for the type of sequence of discrete events being evaluated. The jitter kernel will have a horizontal width measure, for example a standard deviation for a Gaussian function as shown, that may be selected to reflect the normal variations found in the environment of the discrete events.
A lower portion 452 of the graph shows the result of the convolution of the jitter kernel 404 with an autocorrelation function, resulting in a smoothed autocorrelation function having peaks 456 , 458 , 460 , 462 and 464 . The time 454 between a start and a peak of the largest individual peak, in this example 456 , is labeled T* and may be used as an estimate of a period of the potential periodic pattern.
FIG. 5 is a diagram showing a convolution of the autocorrelation with a second jitter kernel and the resulting second smoothed autocorrelation. The graph includes an upper portion 502 illustrating a second jitter kernel 504 convolved with the five shown groups of spikes 506 , 508 , 510 , 512 and 514 . The jitter kernel is again illustrated as being a Gaussian function, but has a different horizontal width as compared to the jitter kernel 404 of FIG. 4 , because jitter kernel 504 has been adjusted by a proportionality based in part upon the value T* found in FIG. 4 . For example, a Gaussian jitter kernel as shown may be selected to have a standard deviation of one tenth of T*. The second jitter kernel will have a horizontal width that may be greater or less than that of the first jitter kernel, but may be selected to better represent the actual variations found in the sequence of discrete events being examined for periodicity as compared to the first jitter kernel. In the example, the Gaussian second jitter kernel is shown as having a narrower horizontal width that the first jitter kernel, which may result in narrower autocorrelation peaks.
A lower portion 552 of the graph shows the result of the convolution of the jitter kernel 504 with an autocorrelation function, resulting in a smoothed autocorrelation function (R s ′) having peaks 556 , 558 , 560 , 562 and 564 . The time 566 between a start and a peak of the largest individual peak, in this example peak 556 , is labeled T, while the time 558 between the start and a second highest peak 558 is labeled T2, and the time 570 to the third peak 560 is labeled T3. As many peaks as desired may be used in determining the elapsed time to various peaks of the second smoothed autocorrelation function.
The values T, 2T, 2T and etc. may be compared with each other to determine if the value T to the first peak is close to a peak at the value of 2T, and close to a peak at the third value of 3T. Mathematical methods to determine if the measured times to each peak represent multiples of a single period, and to evaluate the probability that the determined period is actually a periodic pattern or not may be used. A confidence measure of the probability of periodicity may be computed as the sum of the points of R s ′ evaluated at the period T, at twice the period 2T, at three times the period 3T, and etc.
While various embodiments of the invention have been particularly shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Furthermore, it should be understood that some embodiments are directed to controller 132 , which is constructed and arranged to evaluate a likelihood that a sequence of discrete events displays periodic patterns. Some embodiments are directed to a process of evaluating a likelihood that a sequence of discrete events displays periodic patterns. Also, some embodiments are directed to a computer program product which enables computer logic to cause a computer to evaluate a likelihood that a sequence of discrete events displays periodic patterns.
In some arrangements, controller 132 is implemented by a set of processors or other types of control/processing circuitry running software. In such arrangements, the software instructions can be delivered, within controller 132 , either in the form of a computer program product 140 (see FIG. 1 ) or simply instructions on disk or in pre-loaded in memory circuit 128 , each computer program product having a computer readable storage medium which stores the instructions in a non-volatile manner. Alternative examples of suitable computer readable storage media include tangible articles of manufacture and apparatus such as CD-ROM, flash memory, disk memory, tape memory, and the like. | Sequences of discrete events, such as clicks on a website, are evaluated for periodic behavior, a period is calculated, and the sequence is scored to determine the confidence that the sequence really exhibits periodicity. The random variations on the timing of the discrete events due to transmission delays or other factors may be reduced or eliminated from the evaluation. An apparatus for performing the method of evaluation may include a computer programmed to carry out the method. | 6 |
FIELD OF THE INVENTION
The present invention relates to a self-supporting biphasic collagen membrane for guided tissue regeneration in a human or other mammal and to a method of using such a membrane in bone grafting, particularly in vertical augmentation of the alveolar ridge.
BACKGROUND OF THE INVENTION
Collagen has been used as an implantable biomaterial for more than 50 years. The collagen used for biomedical implants is either derived from animals (e.g., cows, pigs, horses) and humans, or it is manufactured in vitro using recombinant engineering. It is known to be biocompatible and is resorbed and remodeled like natural tissues, via cellular and enzymatic processes.
Conventional collagen implants typically have been made of highly porous, reconstituted bovine (i.e., cow) collagen. These collagen implants are commercially sold to surgeons as rectilinear sheets with uniform thicknesses and porosity. Their low density and high porosity make these collagen membranes supple and conformable. Unfortunately they therefore have inadequate tensile strength and stiffness, particularly after wetting with saline or blood, for use as a containment device in surgical applications.
Bone is the body's primarily structural tissue; consequently it can fracture and biomechanically fail. Fortunately, it has a remarkable ability to regenerate because bone tissue contains stem cells which are stimulated to form new bone within bone tissue and adjacent to the existing bone. Boney defects regenerate from stem cells residing in viable bone, stimulated by signally proteins, and multiplying on existing cells or on an extracellular matrix (i.e., trellis). Like all tissues, bone requires support via the vascular system to supply nutrients and cells, and to remove waste. Bone will not regenerate without prompt regeneration of new blood vessels (i.e., neovascularization), typically with the first days and weeks of the regenerative cascade.
After tooth loss, the adjacent jawbone (maxilla or mandible) frequently resorbs or atrophies. This may cause problems when it is desired to replace a missing tooth with a dental implant because the required depth of bone needed to adequately support the implant may not be present. Thus, prior to implanting a dental implant, it is often necessary for the oral surgeon to regenerate the adjacent bone to at least the minimum depth to provide adequate osteointegration of the dental implant. A common procedure for this purpose is alveolar ridge augmentation.
Various attempts have been made in the past to stimulate or augment bone regeneration by introducing a bone regenerating material proximate a deteriorated bone structure. Such efforts have met with limited success, however, because they have not been able adequately to control the placement of the bone regenerating material and thus guide the development of new or additional bone. Bone regenerating materials are classified as “bioactive” because they are biocompatible and stimulate new bone formation. Examples of bioactive materials are autograft, osteogenic stem cells, osteoinductive proteins, and osteoconductive matrices. Bioactive agents are typically delivered to the operative site by the surgeon as deformable, flowable biomaterials. The predictability of bioactive agents is poor, however because it is difficult to adequately control the placement of the bone regenerating material and thus guide the development of new or additional bone. Liquids, gels, granules, composites can be easily injected from syringes, but they can also go to unintended locations causing severe complications. Moreover, bioactive materials often migrate over time from the desired site. Measures undertaken to control the placement of the bone regenerating material may hinder cell ingrowth and formation of blood vessels needed for development of additional bone and thus impede the desired bone regeneration.
In alveolar ridge augmentation of atrophied jawbones to provide sufficient bone depth to facilitate stable implantation of a dental implant, a principal difficulty is the maintenance of the desired ridge shape, both as to height and as to width. While many answers exist for horizontal grafting, there are very few constructs to facilitate vertical grafting. In the past, bone graft material containment members constructed of titanium mesh have been used to address this problem. Titanium mesh is used because it has the requisite structural strength and integrity to provide containment and yet does not induce adverse effects in proximate tissues. However, because of its long term stability, it is necessary to carry out a second surgery to remove the containment member after the bone graft has achieved the desired degree of osseointegration before a dental implant can be implanted in the augmented bone. This results in concomitant tissue damage and often further delays the installation of the dental implant while the tissues damaged during removal of the titanium mesh containment member heal.
Thus, despite considerable efforts of the prior art, there has remained a long felt need for better methods of bone regeneration, especially for alveolar ridge augmentation in preparation for the installation of dental implants.
SUMMARY OF THE INVENTION
The present invention provides a self-supporting, arcuately curved sheet or tunnel of resorbable collagen which may be used by surgeons as an implantable medical device to aid in a variety of tissue regenerative indications. The self-supporting collagen tunnel provides resorbable biomaterial structure for containing or retaining cells, growth factors or particulate matrices for guided tissue regeneration or augmentation. The collagen tunnel of the present invention is particularly suitable for alveolar ridge augmentation, especially vertical alveolar ridge augmentation.
Assuring precise positioning of implanted tissue augmentation materials in a living body can be a difficult task. Moreover, because a living body is a dynamic environment, implanted materials may shift in position over time. The use of strategically shaped and implanted membranes according to the present invention, however, facilitates precise placement of implanted biomaterials and enables containment or retention of the implanted biomaterial at the desired location within the body.
The present invention makes use of collagen as a resorbable biomaterial for implantable medical devices to aid in tissue regeneration and repair.
Conventional highly porous implantable collagen membranes typically have been made of reconstituted, reticulated bovine (i.e., cow) collagen. Such materials are conventionally provided to surgeons as rectilinear sheets with uniform thicknesses of approximately 1 mm. Their low density and high porosity make such materials supple and conformable. Unfortunately, however, they therefore also have a low tensile strength and stiffness, particularly after wetting with saline or blood, and are inadequate for use as a containment device in surgical applications. Rather, they are difficult to handle and liable to tear themselves. In addition, such materials are difficult to retain in a desired position because they are so thin and fragile that they are difficult to attach at the desired location with a bone tack or suture.
Depending on the extent of cross linking, collagen biomaterials can be manufactured to resorb over a prescribed range, typically from 6 weeks to one year. For alveolar ridge augmentation, it is preferred that the collagen membrane of the tunnel be such that it maintains its shape and structural integrity for a period of from 4 to 6 months before breakdown and resorption occur.
The present invention uses collagen membranes with a curved or arcuately configured shape to facilitate tissue regeneration, particularly bone. This self-supporting curved shape is produced by casting collagen in an appropriately configured mold and lyophilizing, to form a porous collagen structure. The collagen membrane is then collapsed and cross linked to provide a self-supporting membranes of sufficient strength to function as a containment member for the required length of time.
The self-supporting collagen tunnels for guided tissue regeneration in accordance with the present invention may be produced by the following processes.
Collagen suitable for use in the containment members may be obtained by known techniques, for example, from bovine tendons. The collagen may be suitably purified for use by the process described in Nimni et al., U.S. Pat. No. 5,374,539, the entire disclosure of which is hereby incorporated herein by reference. The collagen fibers may also be treated for implantation by the process of Cheung, U.S. Pat. No. 7,008,763, the entire disclosure of which is likewise incorporated herein by reference.
The arcuately curved, self-supporting collagen membrane can be manufactured by a casting process using an appropriately shaped mold. The mold is filled with a collagen suspension. After lyphilization, the mold is opened and the membrane removed. The membrane can then be rehydrated and dried to provide a high strength three dimensional form.
The thickness of the curved, collagen membrane can be adjusted for biological, mechanical or intra-operative handling advantages. Thickness also can alter the resorption rate of the membrane. It can also alter the strength of the membrane, thus modifying the resistance to forces applied by the bioactive or bioinert materials forced into the device. Also, varying the thickness can assist the clinician to locate the device intra-operatively by facilitating handling. Because the thicker portions exhibit stronger mechanical properties, such as tensile strength or tear strength, due to its larger cross-sectional area, the collagen membrane containment member exhibits greatly improved resistance to tearing.
The thickness of the collagen membrane may range from about 0.3 mm to about 3 mm, preferably about 0.4 mm to about 2 mm, particularly preferably about 0.5 mm to 1.5 mm, and especially preferably from about 0.5 mm to 1 mm. The thickness of the resultant membrane can be modified by adjusting the gap between the mold surfaces of the mold in which it is formed.
If increased porosity is desired, macroscopic holes may be made in the membrane with strategically placed pins transecting the mold cavity. Alternatively, holes can be formed in the completed membrane with strategically placed pins, cuts or laser cutting. A third alternative is to use a selective rehydration/drying process in targeted areas of the membrane.
The self-sustaining, curved collagen containment member of the invention is malleable, by which is meant that the membrane can be folded to a desired shape or configuration and then will retain that configuration. This is achieved by bending the membrane beyond the elastic limit of the material and then creasing the membrane at the bending site. As a result, the membrane will retain its shape after being custom bent, intra-operatively by the surgeon.
The curved, collagen tunnel containment member of the invention is preferably distributed in a sterile package.
The self-sustaining collagen tunnel of the invention has a number of important advantages for guided tissue regeneration. It can be readily produced in lengths sufficient to contain a relatively long bone graft and can be readily trimmed to a desired length for shorter bone grafts. Thus, it is unnecessary to manufacture and maintain an inventory of different sized containment members for bone grafts of different lengths because a single standard size can be readily adapted to differing size requirements.
Because the collagen tunnel containment member of the invention is biocompatible and resorbable, it is unnecessary to perform a second surgery to remove the containment member after the bone graft has achieved a sufficient degree of osseointegration. Instead, the containment member of the invention can simply be left in place until it is naturally resorbed by the patient's body.
The self-supporting collagen tunnel of the invention also provides convenience for the surgeon who uses it. For example, if desired, a dental implant can be installed in a patient first without removing the collagen containment member or waiting for it to resorb. Instead, the implant may be successfully installed through the collagen tunnel containment member merely by making a small slit through the containment member at the desired implant location once the desired degree of osseointegration of the bone augmentation material has been achieved. Thus, scheduling flexibility is maximized and overall operating time for the surgeon and staff, as well as the patient, can be conserved by using the collagen tunnel containment member of the invention.
As used herein, the term “lyphilization” refers to “freeze drying” or vacuum drying.
In the process for producing the membranes of the invention, the a molded collagen suspension is placed in a freezer and then a vacuum is applied. Under vacuum, the water within the collagen moves directly from the solid phase to the gas phase. Consequently, there is no shrinking or change to the dimensions. This makes a highly porous, but relatively weak collagen structure. A key step in the production process according to the invention is then to lightly wet the porous collagen with water which collapses the porosity. The material is then air dried. This makes a much stronger/stiffer collagen membrane. Air drying also crosslinks some of the collagen molecules to further increase the strength and decrease the resorption rate.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be described in further detail hereinafter with reference to illustrative examples of a preferred embodiments shown in the accompanying drawing figures, in which:
FIG. 1 is a schematic perspective representation of a first embodiment of a self-supporting collagen tunnel containment member according to the present invention;
FIGS. 2 a , 2 b and 2 c are, respectively, a side view, an end view and a perspective view of a second preferred embodiment of the collagen tunnel containment member of the invention designed specifically for posterior mandible applications; and
FIGS. 3 a , 3 b and 3 c are, respectively, a side view, a plan view and an end view of a third preferred embodiment of the collagen tunnel containment member of the invention designed specifically for anterior maxilla applications.
It should be understood that these illustrations are only examples and that the collagen tunnel containment member of the invention may exist is a variety of configurations other than those shown in the drawings.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an illustrative collagen tunnel containment member according to the present invention. The containment member of the invention is comprised of single curved sheet of collagen having sufficient strength and structural integrity to be self-supporting. By “self-supporting” is meant that the collagen sheet must be sufficiently rigid that when the longitudinal edges of the curved collagen sheet are placed on a flat surface, it will not limply collapse against the surface, but instead will maintain its curved configuration with the central portion of the curved sheet elevated above the supporting surface.
However, the collagen sheet should not be absolutely rigid. Rather it is desirable for the collagen tunnel containment member to have sufficient flexibility that the oral surgeon can bend it to a desired configuration to fit the surgical installation site without cracking or creasing. After placement by the surgeon, the collagen tunnel can be held in the desired location by conventional bone tacks or bone screws.
As can be seen in FIG. 1 , a preferred embodiment of the collagen tunnel membrane of the invention may have the configuration of a circumferential segment of an elongated tube such that the tube has a radially open face (see also FIGS. 2 b and 2 c ). The collagen tunnel containment member of the invention typically may have a radius of curvature a in the range from about 5 to about 10 mm, an overall curved width b in the range from about 10 to about 25 mm, a tunnel width c in the range from about 10 to about 20 mm, a height h in the range from about 3 to about 8 mm and an overall length I in the range from about 10 to about 40 mm. Of course, the shape of the collagen tunnel can be varied in height and width allowing for various grafting needs. It is understood that the collagen tunnel may be readily trimmed using either scissors or a scalpel and/or bent to fit a desired installation site. In particular, it is understood that the collagen tunnel containment members will be manufactured in lengths longer than the length of a typical bone augmentation site and then trimmed to fit the site by the surgeon at the time of installation. In this way, it is possible to use a single size of collagen tunnel to fit various sized installation sites, and it is unnecessary to maintain an inventory of different sized containment members.
FIGS. 2 a , 2 b and 2 c show another preferred embodiment of the collagen tunnel containment member of the invention. This embodiment is particularly designed for posterior mandible applications. The posterior mandible containment member takes the form of a sheet bent into a bight with two legs of uneven length joined by a curved center section. This design allows the containment member to be placed securely over the mandible, after which it can be securely tacked in place by placing bone tacks through one or both legs. The uneven lengths of the two legs allow the containment member to better fit the typical dimensions of the oral cavity adjacent the posterior mandible. The optimum dimensions of the containment member will necessarily vary depending on the size of the patient in whom the containment member is to be employed. However, in general the containment member may advantageously have an overall length of 35±5 mm; the two legs may have heights of 25±5 mm and 16±3 mm, respectively; and the spacing between the legs (i.e. the diameter of the curved section joining the two legs) may be about 8±1 mm. Moreover, the resorbable collagen material, from which the containment member is formed, can readily be trimmed to fit by the surgeon upon implantation. Then the tunnel or chamber formed under the curved center section between the containment member and the mandible can be filled as needed with bone augmentation material.
FIGS. 3 a , 3 b and 3 c depict another especially advantageous embodiment of the containment member of the invention designed particularly for anterior maxilla applications. This embodiment takes the general form of a segment of a circle having a curvature that generally matches the curvature of the jaw of the patient in whom the containment member is to be employed. The containment member is bent or folded along a circumferential line “C” to form a peaked structure, best visualized in FIG. 3 c . A tab “T” may be provided to facilitate handling of the containment member, as well as providing a securing site for insertion of a bone tack to fasten the containment member in place in a patient. In the illustrated embodiment, the tab is shown projecting radially inwardly from the center of the containment member, but persons skilled in the art will appreciate that such tabs could alternatively be located at other positions on the containment member. Likewise, only a single tab is shown, but persons skilled in the art will appreciate that more than one tab could be provided as needed. After the containment member is installed in a patient over the anterior maxilla, the resulting tunnel or chamber formed between the peaked portion of the containment member and the patient's maxilla can be packed as needed with bone augmentation material.
After installation of the collagen tunnel containment member at the desired surgical site, the tunnel is filled or packed with a suitable bone regeneration material, such as autograft, allograft, growth factors, or ceramic particles, for example apatite. Numerous such materials are well known in the art and are commercially available from various manufacturers. The collagen tunnel assures proper space maintenance and restrains the bone grafting material to exactly the correct location and configuration for maximum bone formation.
The capsule can be filled with bone graft material such as autograft, allograft, growth factors, or ceramic particles. The apical portion and lingual side are formed with a matrix of perforations which give these regions a high porosity for facilitating neovascular ingrowth. The buccal portion has high stiffness to retain the bone graft material crestally. As a result of this advantageous capsule structure, when the capsule is filled with bone regenerating material and properly inserted into the socket of an extracted tooth, the buccal plate is restored with regenerated bone to the height desired by the surgeon.
The self-supporting, curved, collagen tunnel containment members of the invention may be produced by the following casting process:
A 10-60 mg/ml suspension of purified collagen in 5-25% alcohol/water is formed. A particularly preferred suspension contains 15 mg of collagen per ml of a 10% solution of ethanol in water. The collagen fibers preferably have a native fibrous structure and a length of from 0.2 to 3 mm, particularly preferably about 1.5 mm. After removing air bubbles from the suspension, a fixed amount of the suspension is poured into a mold comprised of mating male and female mold members which form a curved mold cavity between them. The mold cavity is completely filled with the collagen suspension, and the main frame of the mold is tightly attached to the elastic surface of bottom plate.
The filled mold was then placed in −70° C. freezer. After solidification of the collagen matrix, one of the two vertical plates holding the frozen collagen was removed. The other vertical plate was also removed with the collagen on it. The plate with the frozen collagen was subsequently freeze-dried in a freeze-dryer.
The dried collagen was removed from the Freeze-dryer and sprayed with an alcohol solution. A preferred alcohol solution will contain 40 to 70% alcohol. A particularly preferred solution contains about 50% alcohol. The collagen material was then subjected to air drying followed by vacuum drying. The material was then heated at 100 to 140° C. for from 15 minutes to 2 hours. A preferred heat treatment is effected at 130° C. for 30 minutes. The heat treated collagen tunnel was then removed and cut to the desired size. The resulting material has a tensile strength of approximately 3600 g/mm 2 (35 MPa), a tensile modulus of approximately 95,000 g/mm 2 (932 MPa), pore diameters of less than 50 microns, and a porosity of less than 20%.
The thickness of the resorbable sheet material used to make the containment member of the invention may be varied, depending on circumstances, but typically the collagen material will have a thickness of about 0.7±0.2 mm.
The properties of the collagen structure may be varied to adjust the time frame for tissue break down and the loss of the structure of the geometric shape. Depending on the extent of cross-linking, collagen biomaterials can be manufactured to resorb over a prescribed period of time ranging from 6 weeks to a year or more. The rate of break down and resorption can also be varied by adjusting the thickness of the collagen membrane. Preferably, the collagen tunnel containment member of the invention will maintain its shape and structural integrity for a minimum of 4 months, especially preferably 4 to 6 months, to provide time for the bone graft material to integrate into the bone, after which time the collagen tunnel will break down naturally and be resorbed by the patient's body.
The self-supporting, curved collagen tunnel containment member of the present invention provides predictable space maintenance while at the same time being able to achieve ultimate biologic resorption (i.e., dissolution of the barrier) not heretofore available in the medical/dental grafting world. The collagen tunnel of the invention provides horizontal and vertical containment while promoting tissue healing using the unique properties of collagen. The collagen tunnel of the invention is capable of providing both graft containment and height and width space maintenance at the same time. The collagen fiber construction allows predictable breakdown of the geometric shape and maintains the desired geometry for the needed time frame of from four to six months so that the bone graft can mature and attain the strength to support the adjacent soft tissues and, ultimately, one or more dental implants.
The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed broadly to include all variations within the scope of the appended claims and equivalents thereof. | A biocompatible, self-supporting, curved, collagen membrane adapted to be secured by bone tacks or bone screws over exposed bone at a desired bone graft site in the alveolar ridge of a patient such that the membrane defines a space having a predetermined height and width over the exposed bone, in which the membrane maintains its structural integrity for at least 4 months after implantation at the bone graft site and then naturally breaks down and is resorbed by the patient's body, a method of making such a membrane, and a method of using such a membrane for vertical augmentation of the alveolar ridge of the patient. | 0 |
RELATED APPLICATIONS
[0001] This is a continuation of U.S. application Ser. No. 11/972,094, filed Jan. 10, 2008, the entirety of which is incorporated herein by reference. This application claims priority from U.S. application Ser. No. 11/972,094.
FIELD OF THE INVENTION
[0002] Generally, the invention relates to litter boxes for pets. More specifically, the invention relates to litter boxes that can be used by dogs as well as cats and that does not require the use of traditional cat litter material.
BACKGROUND
[0003] The following description provides a summary of information relevant to the present invention. It is not an admission that any of the information provided herein is prior art to the presently claimed invention, nor that any of the publications or devices specifically or implicitly referenced are prior art to that invention.
[0004] Cat litter boxes have been in general use by the public for quite some time, and there are many types from which to choose. Generally, the traditional cat litter box is a rectangular container with raised walls on three sides and a lowered wall on the entry side where the cat enters the container. The traditional container holds cat litter material, which is used to attract the cat and absorb cat feces and urine odor. This has worked well for cats, but has not generally been adopted for use by dogs.
[0005] Dogs have traditionally had few options when it comes to relieving themselves indoors. Traditionally, dogs tended to live outdoors and were free to relieve themselves in outdoor areas. More recently, dog owners have been bringing their dogs indoors for several reasons. One reason is that smaller breed dogs have become increasingly popular, and these breeds are suited for indoor living. In fact, they tend to prefer living indoors in close relationship with their owners.
[0006] Another reason for this shift in the living relationship between dogs and humans is that more and more people have been moving into smaller dwelling units that do not have back yards, or have very small outdoor spaces. This shift from traditional homes with yards to smaller homes, such as condos, townhomes and apartments has not reduced people's desire to share their lives with pets. Instead, it has created a greater demand for products that enable indoor living for pets, particularly dogs. Thus, there is now a particular need for products and services that allow pet owners to potty train their pets. There is a corresponding need for indoor pet potties, particularly those suitable for use by dogs.
[0007] As explained above, cats presently have many options that involve using cat litter inside of some form of cat litter box indoors. Dogs, however, have just a few options when it comes to housebreaking and using the bathroom indoors.
[0008] One option is to use a litter box with litter in a manner very similar to what cats use. The problem with such litter boxes for dogs is that dogs like to bury their waste, which results in litter being flung all over the room in which the litter box is placed. In addition, puppies, and some dogs, tend to eat the litter, which is very unhealthy and can lead to serious digestive and other health problems.
[0009] Another option is to lay newspaper or other suitable paper product on the floor and housetrain the dog to use it exclusively. The problem with such an approach is that most paper products don't absorb urine very well, and they tend to leak through to the floor. Moreover, dogs tend to step in the urine on the newspaper and track it all over the house with their paws. Another problem is that puppies tend to tear the paper into shreds and create a big mess all over the house.
[0010] To address these deficiencies in newspaper use, absorbent pads have been created. These pads tend to have one or more layers of absorbent material and a backing layer of material that is impervious to fluid so as to prevent urine from leaking through to the floor beneath the pad. The problem with these absorbent pads, however, is threefold: (1) puppies tend to tear them to shreds as they do with paper products; (2) in their attempt to bury their waste dogs tend to fling the pads out of position and scatter them around so that they are not useful after one use; and (3) the pads do not absorb the urine quickly enough so that dogs tend to track the urine around the house with their paws after stepping in it just after urinating.
[0011] Another solution has been to use large crates that house artificial grass or real sod that is periodically replaced. There are several companies that make various versions of such a product. The problems with that solution are threefold: (1) the artificial grass or sod must be replaced every week or two weeks at most, and even then there is a buildup in odor; (2) these crates tend to be very expensive and can cost between $150 to $600 just for the crate and the first installation of sod; and (3) the replacement sod or grass is also very expensive and results in recurring costs over the entire lifetime of the product.
[0012] Another solution has been the creation of an indoor dog potty that can hold absorbent pads or newspapers in a manner inaccessible to dogs. One such type of dog potty is made of a rectangular base plate fitted with a unitary removable grid. The base plate can hold a newspaper or absorbent pad inside with the grid placed atop the newspaper or absorbent pad. The dog goes to the bathroom atop the grid and the pee passes through the grid to the newspaper or absorbent pad below. The problem with such a product is that the unitary grids tend to be large and difficult to handle and clean. In addition, the grids are often made from lighting louver material or other material and may not be suited for all dogs' paws.
[0013] Thus, there is a need for an affordable, safe, convenient, and clean pet potty that can be used to housetrain pets and provide them with a means to relieve themselves indoors. The present invention solves all of the aforementioned problems associated with current housetraining and indoor potty devices.
SUMMARY OF THE INVENTION
[0014] In accordance with one embodiment, a pet potty includes a base plate and a grid. The base plate has a base and a wall along the perimeter of the base, the base and wall being impermeable to fluid and forming a cavity capable of retaining fluid. The grid is sized to fit within the cavity of the base plate and has a complex of beams that can support a pet atop the grid. The beams have a top side and a bottom side, and substantially all of the beams are convex in shape on their top side.
[0015] In accordance with another embodiment, a pet potty includes a base plate and two or more grids. The base plate has a base and a wall along the perimeter of the base, the base and wall being impermeable to fluid and forming a cavity capable of retaining fluid. The two or more grids are sized to fit within the cavity of the base plate such that when the grids are placed in the cavity the grids are substantially immovable in any horizontal direction. The grids each have a complex of beams that can support a pet atop the grid. The beams have a top side and a bottom side, and substantially all of the beams are convex in shape on their top side.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] These and other features and advantages will be apparent from the following more particular description thereof, presented in conjunction with the following drawings, wherein:
[0017] FIG. 1 is a perspective view of a pet potty in accordance with one embodiment.
[0018] FIG. 2 is an exploded view of the pet potty depicted in FIG. 1 .
[0019] FIG. 3 is a top view of the pet potty depicted in FIG. 1 .
[0020] FIG. 4 is a bottom view of one of the grids of the pet potty depicted in FIG. 1 .
[0021] FIG. 4A is a side view of the grid through lines A-A in FIG. 4 .
[0022] FIG. 4B is a side view of the grid through lines B-B in FIG. 4 .
[0023] FIG. 5 is a three-dimensional close-up view of a portion of the grid depicted in FIG. 4 .
[0024] FIG. 6 is a perspective view of the pet potty depicted in FIG. 1 with a raised drainage attachment.
[0025] FIG. 7A shows a side cut-out view of one of the grids of the pet potty depicted in FIG. 1 with a series of disposable layers adhered to the grid.
[0026] FIG. 7B shows one of the disposable layers of FIG. 7A being peeled off the grid.
[0027] FIG. 8 shows a three-dimensional close-up view of a portion of the grid depicted in FIG. 4 with one of the disposable layers depicted in FIGS. 7A and 7B being peeled off the grid.
DETAILED DESCRIPTION
[0028] The pet potty systems depicted herein can be used to housetrain and act as an indoor potty for dogs and cats. They are, however, particularly suitable for dogs.
[0029] Turning now to FIG. 1 , a pet potty 100 in accordance with one embodiment depicts a rectangular base plate 110 fitted with a double grid system having grids 150 and 160 . The grids 150 and 160 are removable from the base plate 110 . When the grids 150 and 160 are positioned in the base plate 110 the grids fit snuggly in the base plate such that there is little or no movement in any horizontal direction between the grids 150 and 160 and the base plate 110 . The grids are capable of supporting the weight of any breed of dog.
[0030] As shown in FIG. 2 , the base plate 110 is formed of a base 111 surrounded on its perimeter by a raised wall 114 . A raised wall 114 extending upward from the base 111 forms a cavity 115 in the base plate 110 . The wall is preferably about ¾ of an inch tall, but can be from between about ¼ of an inch tall to about 3 inches tall. The grids 150 and 160 fit snuggly within the cavity 115 . The grids 150 and 160 can be removed from the base plate 110 by lifting them vertically upward. Finger ports 157 are provided for this purpose and are positioned on the outer sides of each of the grids 150 and 160 . The grids 150 and 160 are mirror images of each other. The finger ports 157 are placed on the outer sides of the grids 150 and 160 , because there is less likelihood of the outer edges of the grids 150 and 160 being covered with feces.
[0031] The grids 150 and 160 each have a number of spacers 155 along the three outer sides 156 of the grids 150 and 160 . There are no spacers along the side 158 of the grids 150 and 160 that touch each other. The spacers 155 form a space between the outer sides 156 of the grids 150 and 160 and the wall 114 of the base plate 110 . The spacers 155 ensure that there is no horizontal movement between the grids 150 and 160 and the base plate 110 when the grids 150 and 160 are positioned inside the cavity 111 of the base plate 110 . As best shown in FIG. 3 , the spacing between the grids 150 and 160 and the wall 114 of the base plate 110 established by the spacers 155 also makes it easier to grip the finger ports 157 with two fingers. Alternatively, the grids can be sized exactly to fit the cavity 115 of the base plate 110 . As best shown in FIG. 3 , there is no space between the inner sides 158 of the grids, which touch each other.
[0032] The base 111 has a plurality of upwardly projecting bumps 116 formed thereon. The bumps 116 are curved, but can be of any shape and size. The bumps 116 help to stabilize the base 111 and prevent it from warping during the manufacturing process or over time.
[0033] FIG. 4 depicts grid 150 as an example. Each structure and element of grid 150 is mirrored in grid 160 . Grid 150 is formed by a complex of beams 165 that are interconnected within the boundaries of the outer edges 156 and 158 of the grid 150 . The beams 165 of grid 150 are supported by edges 156 and 158 , which extend downward a distance x from the beams 165 of the grid 150 , and by a plurality of columns 170 , which also extend downward a same distance x from the beams 165 . The distance x is preferably about ¾ of an inch, but can be anywhere from about ¼ of an inch to about 3 inches. There can be as few as one column 170 supporting the beams 165 and as many as fifty columns 170 supporting the beams. Preferably, there are at least five columns 170 supporting the beams, as shown in FIG. 4 .
[0034] As best shown in FIGS. 4A and 4B , the beams 165 have a top side 167 and a bottom side 168 . The bottom side 168 of the beams 165 do not extend downward the same distance x as the columns 170 and edges 156 and 158 of the grid 150 . Therefore, the bottom side 168 of the beams 165 do not touch the base 111 of the base plate 110 (both shown in phantom in FIGS. 4A and 4B ).
[0035] As best shown in FIGS. 4A and 5 , the bottom side 168 of the beams 165 can be flat, concave, convex, or any shape. The top side 167 of the beams 165 can be convex (i.e., slightly rounded) in shape. The convex shape of the top side 167 of the beams 165 helps to cushion the paw pads of dogs and cats. The beams 165 are at least 0.15 inches thick (as shown in distance z in FIG. 5 ), which further ensures the safety and comfort of dogs' and cats' paw pads. As shown in FIG. 5 , there are holes or openings between the beams, and the beams 165 are separated by a distance y across the openings between the beams 165 . This distance y between the beams 165 is preferably no greater than about ⅜ of an inch. In any case, distance y is less than ⅝ of an inch. The small distance between the beams reduces the risk that the smallest paw pads of the smallest dog breeds gets stuck inside of the openings between the beams 165 rather than being supported atop the beams 165 .
[0036] An additional feature of the pet potty 100 can be a series 200 of protective disposable layers of material 210 adhered atop the grids 150 and 160 . This feature is best shown in FIGS. 7A , 7 B and 8 . Each disposable layer 210 is made of at least one layer having adhesive material on the bottom side 212 and non-adhesive material on the top side 214 . Alternatively, each disposable layer 210 can be made of two layers of material, a top layer 214 and a bottom layer 212 . The top layer 212 does not have an adhesive, and the bottom layer 214 has an adhesive. The bottom layer 214 (or bottom side) of each disposable layer 210 adheres to the top layer 212 (or top side) of the disposable layer 210 below it. As shown in FIGS. 7B and 8 , each disposable layer 210 can be periodically removed after it is soiled by the pet revealing a clean disposable layer 210 below it. The series of protective disposable layers 200 can be provided in packets of two, three, four, five, six, seven, eight, nine, ten, or more disposable layers 210 . The series of disposable layers 200 preferably has the same general shape and dimensions of the grids 150 and 160 and the length and width of each adhesive layer 210 of the series of disposable layers 200 is generally the same as the beams 165 of the grids 150 and 160 .
[0037] The pet potty 100 is depicted in the figures as being rectangular, but it can be round, oval, square, or any shape that provides enough space for a dog or cat to sit atop and relieve herself or himself. For example, it can be shaped like a bone or a fire hydrant or any other fanciful shape. In one embodiment, such as that shown in the figures herein, the pet potty 100 is about 19 inches in width (shown as W in FIG. 3 ) by about 26 inches in length (shown as L in FIG. 3 ), and the cavity 115 or elimination space can be about 16 inches in width by about 24 inches in length. In other rectangular embodiments, the pet potty 100 can be about 14 inches in width and 19 inches in length with a cavity or elimination space of about 12 inches in width and 15.5 inches in length.
[0038] The grids 150 and 160 can also be of any size or shape. In the embodiment shown in the figures, the grids can be about 12 inches in length by about 16 inches in width each. In yet another embodiment (not shown in the figures), the pet potty can have one large single grid that is about 24 inches in length by about 16 inches in width, rather than having a double grid system such as that shown in the figures.
[0039] As shown in FIG. 6 , the pet potty 100 can be fitted with a raised drainage attachment 300 . The raised drainage attachment 300 can best be utilized by male dogs that raise their legs when they urinate. The drainage attachment 300 can have three walls, leaving an opening along one of the long sides of the pet potty 100 so that the dog has a way to get on the pet potty. Alternatively, the raised drainage attachment 300 can have just one wall, preferably along one of the long sides of the pet potty 100 . The three walls of the drainage attachment 300 can be of a unibody construction made from a single mold. Alternatively, the drainage attachment 300 can be constructed by attaching the three walls together through various types of attachments that are known in the art. Each wall of the drainage attachment 300 has an internal side 315 facing the pet potty 100 , and an external side 320 facing outward and away from the pet potty 100 . The bottom edge of the internal side 315 of the walls forms a drainage lip 310 . The drainage lip 310 extends laterally inward toward the cavity 115 of the base plate 110 of the pet potty 100 . The drainage lip 310 extends just over the internal edge of the perimeter wall 114 of the pet potty such that fluid that drains down the internal walls of the drainage attachment 300 flows into the cavity 115 of the base plate 110 of the pet potty 100 . A retention lip (not shown) can extend inwardly from the bottom edge of the external wall 320 and under the bottom of the base plate 110 . The retention lip can be used to firmly secure the drainage attachment 300 to the pet potty 100 . The drainage attachment 300 can be attached to the pet potty 100 by sliding the pet potty into the groove formed between the bottom of the drainage lip 310 and the top of the retention lip (not shown). The height of the drainage attachment 300 can be any height between about four inches and about twenty-four inches, preferably between about twelve inches and about eighteen inches, and preferably about sixteen inches.
[0040] Although illustrative embodiments of the present invention have been described herein in connection with the accompanying drawings, it is to be understood that this invention is not limited to these embodiments and that various changes and modifications may be effected therein by those skilled in the art without departing from the spirit of the invention. | A pet potty includes a base plate and a grid. The base plate has a base and a wall along the perimeter of the base, the base and wall impermeable to fluid and forming a cavity capable of retaining fluid. The grid is sized to fit within the cavity of the base plate and has a complex of beams that can support a pet atop the grid. The beams have a top side and a bottom side, and substantially all of the beams are convex in shape on their top side. | 0 |
BACKGROUND OF THE INVENTION
AND MATERIAL DISCLOSURE STATEMENT
The present invention relates to a methodology for precision cutting of discrete devices such as found, for example, in the MEMS (Micro-Electro-Mechanical Systems) arts. In particular the present invention is directed to the utilization of resin bond and nickel bond dicing blades in a methodology for the dicing of very small discrete devices such as ink jet printheads.
There are many prior art discrete devices which are formed as a plurality of substrates integrally formed in a wafer or the like and which require intermediate cuts and/or separation into individual sub-units as a step in the fabrication process. Examples of such discrete devices and MEMS are ink jet printheads, lasers, magnetic heads, and semiconductor sensor devices. Most, but not all, of the devices are formed in silicon-based wafers. A preferred technique for separating the sub-units is to saw through the wafer in a procedure referred to as “dicing”. The device used to perform the cutting is referred to as a dicing blade or dicing saw. For cutting operations requiring high precision (±10 microns) resin bonded or resinold/diamond blades have been preferred, especially in the production of thermal ink jet printheads, because they form precisely placed, smooth chip-less cuts. These resin bond blades have been typically constructed of a resin-diamond blend. For example, a resinold/diamond blade is disclosed in U.S. Pat. No. 4,878,992 incorporated in its entirety for its teaching, which is constructed of a relatively hard, dense resin bonded material and a 60 to 90% concentration of natural or synthetic diamonds. Other resinold/diamond blades and their use are disclosed in U.S. Pat. Nos. 5,160,403, 5,266,528 and 4,851,371 also incorporated in their entirety for their teaching.
These resin bonded or resinold/diamond blades still suffer from performance variability manifested in the asymmetric wear of the blade periphery and shortened blade life due to chipping caused by the forces generated when pieces of silicon or diamond particles loosened from the dicing blade become jammed between the rotating dicing blade and the silicon wafers being cut. The use of natural or synthetic diamonds also adds to the expense and thereby the desirability of limiting wear and extending blade life.
For a thermal ink jet device it is extremely difficult to produce a high quality cut surface on the device, while maintaining a high cut placement accuracy. The accuracy of cut placement is limited by the necessary use of a soft (phenolic resin) bond dicing blade. A resin bond dicing blade provides the necessary cutting quality, without causing chipping and cracking damage to a relatively brittle silicon device. However, the resin bond blade has a number of limitations when used to dice an ink jet device. These limitations include: (1) rapid and (2) uneven blade wear, (3) decreased cut placement accuracy (+/−6 μm @ 1σ) due to both blade bending and abnormal blade wear, and (5) limited feed rate throughput (1-3 mm/sec. Feed rate).
Use of nickel bonded dicing blades overcomes the limitations of resin bonded blades. But, nickel bonded blades have problems of their own. In particular they cannot provide the required cut quality that must be achieved for the proper functioning of an ink jet printhead. Nickel bond dicing blades are used throughout the semiconductor industry in applications where silicon devices need to be diced on wafers. In most applications, the cut quality requirements are driven by a need to minimize cut edge chipping only along the top and bottom surface of the wafers. Many dicing applications like IC chip fabrication can withstand levels of chipping that are unacceptable when applied to dicing thermal ink jet, micro-lasers, or MEMS devices. This is due to the fact that the function of the dicing cut in standard applications is only to separate the devices and any expected chipping can be accounted for in the design of the wafer dicing street width (chip kerf area) and by blade selection. Because of the greater strength of nickel bonded blades they can be used at much greater feed rates for increased throughput. Feed rates for standard wafer dicing operations may approach and even exceed 100 mm/sec., depending on the material being diced. Nickel bond blades also provide excellent cut placement accuracy due to the high strength and low wear rate which provide resistance to bending and uneven blade wear.
With thermal ink jet devices there are two requirements which must be met. The first purpose is of course to separate the devices. However the second and more critical purpose of the cut is to expose and define the ink outlet surface of the die. To achieve this a high quality surface finish is necessary to ensure that uniform ink drop formation generation and directionality when used in the printer. It is critical that chipping is minimized on this surface to prevent misdirection of the ink drop, which thereby degrades print quality. Tests utilizing nickel bond blades has shown that that the surface finish therein provided is not acceptable.
Therefore, as discussed above there exists a need for a technique and methodology which will solve the problem of providing an acceptable surface finish while also providing greater throughput, less rapid and uneven wear, greater cut placement accuracy, and avoid undesirable cut angles. Thus, it would be desirable to solve this and other deficiencies and disadvantages with an improved methodology.
SUMMARY OF THE INVENTION
The present invention relates to a method for micro-machining ink jet printheads on a substrate, comprising sawing the substrate with a first saw blade to yield a first pass kerf on the substrate. Where the first pass kerf has a first kerf width. This is followed with polishing the first pass kerf with a second saw blade to yield a second pass kerf from the first pass kerf. The second pass kerf has a second kerf width, which is wider than the first kerf width.
More particularly, the present invention relates to a method for dicing ink jet printheads from a substrate having a front side and a back side. First by sawing the substrate with a first saw blade to yield a first pass kerf on the front side of the substrate. The first pass kerf has a first kerf width. Then polishing the first pass kerf with a second saw blade to yield a second pass kerf from the first pass kerf, where the second pass kerf width is wider than the first pass kerf width. The final step being sawing the substrate from the back side of the substrate in alignment with the second pass kerf and intersecting the second pass kerf.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an isometric depiction of two types of saw blade arrangements with their respective mounting on a dicing machine.
FIG. 2 depicts a cross-sectional view of a substrate being diced according to the present invention.
DESCRIPTION OF THE INVENTION
FIG. 1 provides an isometric depiction of two types of saw blade arrangements with their respective mounting on a dicing machine. A typical flange-less blade arrangement 100 is commonly employed with nickel bonded blades. Spindle 101 has stacked upon it wheel mount 102 followed by flange 103 . Saw blade 104 is located between flange 103 and flange 105 . Flange 105 , is in turn, bounded by flange nut 106 and lock nut 107 . A resin bonded blade however, is typically employed as a hub type saw arrangement 110 . Spindle 101 has placed upon it hub wheel mount 111 which receives thereon hub type blade 112 . The hub type blade 112 is held in place with hub flange nut 113 and lock nut 107 .
FIG. 2 depicts a schematical representation of a typical substrate 200 of undiced ink jet printer heads as viewed in cross-section and ready for dicing. The substrate is actually composed of a sandwich of bonded silicon wafers having a polyimide layer between. The lower silicon wafer is referred to as a heater wafer 201 . Arranged upon the heater wafer 201 is the polyimide layer 202 which is approximately 30 microns thick. On top of the polyimide 202 is placed the channel wafer 203 . It is in this channel wafer 203 that the ink jets have been etched into with prior processing steps. These layers are aligned and bonded under heat and pressure to form substrate 200 having a typical composite thickness of approximately 1.15 millimeters. Prior to the dicing operation, a relief 204 is cut into the backside of the substrate 200 . The substrate is placed upon tacky tape and put in a frame which is secured to the dicing saw by a vacuum chuck.
In a preferred embodiment of the invention, two saw passes are made in the dicing operation. A first pass cut 205 is performed in a preferred embodiment with a nickel bonded blade type. This first pass cut 205 is narrow in kerf, typically 150 microns in a preferred arrangement, and has a depth of cut at least sufficient to cut through and past the polyimide layer 202 . In our current example this is a cut depth of approximately 600 microns. However, what is important to a preferred embodiment operation of the invention is that the polyimide layer 202 is cut completely through with the first pass cut 205 .
The first pass kerf 205 is not centered in the street between printheads. The street is that area allowed for by design for dicing to take place. The street is indicated here by alignment lines 206 and 207 . Alignment lines 206 and 207 are provided in the figure as visual aides in delineating the street and the bounds of the ink jet heads. Alignment line 206 represents where the polished ink jet printhead face is desired and is where the jet outlets are to be formed by the dicing operation. The amount of material on the side wall of the first pass kerf 205 to the face alignment line 206 is in a preferred embodiment about 20 microns. This leaves about 50 microns of material on the other side wall to alignment line 207 . However, the amount left here is not critical. This first pass cut 205 may have relatively poor surface finish so long as it has cut through the more abrasive and difficult to cut polyimide layer 202 .
The second pass polishing cut 208 is aligned with the first pass cut but uses a wider kerf blade on the dicing saw. Dotted line 209 is provided as a visual aid in depicting the preferred arrangement for the alignment of the first pass cut 205 relative to the second pass cut 208 . In a preferred embodiment the blade used for the second pass cut 208 is a resin bonded type. In a more preferred embodiment the blade is a phenolic resin diamond type such as described in U.S. Pat. No. 5,637,388 to White, et al., which is incorporated by reference herein in its entirety for its teaching. In a preferred embodiment the kerf width is 220 microns in width. It is also arranged such that the blade cutting depth completes the cut through the relatively softer silicon of heater wafer 201 to separate the ink jet heads. However, the invention may be practiced without providing the final separation of ink jet devices as will be evident to those skilled in the art. Examples of various dicing approaches may be found in U.S. Pat. Nos. 5,057,853, 5,306,370, 5,506,610, and 5,408,739, which are herein incorporated by reference for their teaching.
The primary aim of the second pass cut 208 is to polish the first pass cut 205 . In a preferred embodiment it is to polish the face of the ink jet print head back to alignment line 206 . As noted above, the second pass cut 208 while wider of kerf is not necessarily centered on the previous first pass cut 205 . In a preferred embodiment arrangement, the alignment of second pass cut 208 overlaps the first pass cut 205 (as depicted by dotted line 209 ) on one side by 20 microns and by 50 microns on the other. This arrangement is based upon empirical data which shows that 20 microns to the ink jet face achieves the best result in cutting the ink jet outlets. This arrangement provides the requisite amount of accuracy, avoiding any chipping of the ink jet outlet channel at the ink jet face, while providing an exemplary degree of surface finish.
In effect first pass cut 205 acts as an alignment guide for the second pass polishing cut 208 . By virtue of first pass cut 205 keeping the resin bonded blade of cut 208 in alignment there is considerably less flexure of the blade. This significantly helps to reduce uneven blade wear for the resin bonded blade. This reduction of blade flexure also contributes to improved accuracy of cut, as there is less blade wander in the street. This reduction of uneven blade wear in combination with prior cutting of the relatively more abrasive polyimide by the first pass cut, yields the improved wear data as shown in the following table:
Blade Wear (μm/wafer)
Trial #
Resin
Resin & Nickel
1
18
5
2
12
2
3
10
6
4
18
1
5
16
1
Average
15
3
As can be seen from examination of the above table there is an approximate five to one reduction in resin bonded blade wear utilizing the present invention. Furthermore, all of the above attributes contribute to allowing a more than double increase in the bonded blade saw feed rate, from about 3 mm/sec feed rate to one of approximately 7 mm/sec.
In a preferred embodiment, a double spindle feed saw is utilized. One example of which is as sold by the manufacturing company Disco™. In a preferred approach the resin bonded blade is mounted in-line behind the nickel blade. However, as will be apparent to one skilled in the art other approaches may be used as for example by offsetting the blades by the street-to-street distance so that a first pass cuts just the narrow kerf, with each subsequent pass cutting both a new narrow kerf while polishing wider the prior pass narrow kerf. That is until the last pass on the wafer of course, where only the last polishing for the wider kerf is cut.
In a further embodiment, a surfactant may be used in the second pass polishing cut. This has some benefit in improving the surface polish finish achieved on the face of the ink jet printhead. For fabrication of other types of micro devices this can be of particular importance (lasers for example). One such surfactant which has been successful is Diamaflow™. But those skilled in the art will be readily able to determine other surfactant choices.
In summary, practicing the methodology of the present invention reduces rapid blade wear and abates uneven blade wear for resin bonded type blades. Due to the reduced blade wear coupled with reduced blade bending, the cut placement accuracy is improved. Finally, the present invention allows a greater feed rate throughput. This means that a dicing tool will be down less for blade changes while also achieving greater product throughput in the manufacturing environment.
While the embodiment disclosed herein is preferred, it will be appreciated from this teaching that various alternative, modifications, variations or improvements therein may be made by those skilled in the art, which are intended to be encompassed by the following claims. | A method for dicing small devices including MEMS, ink jet printheads, lasers etc. The method comprises making a first pass cut into a substrate with a blade of narrow kerf and having long wear characteristics. This first pass cut is then followed with a polishing blade of wider kerf having desirable smooth cutting qualities. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 14/829,136, filed on Aug. 18, 2015, (issuing as U.S. Pat. No. 9,528,325 on Dec. 27, 2016), which is a continuation of U.S. patent application Ser. No. 13/710,644, filed on Dec. 11, 2012 (now U.S. Pat. No. 9,109,417), which claims benefit of U.S. Provisional Patent Application Ser. No. 61/665,110, filed Jun. 27, 2012, each of which applications are incorporated herein by reference and to which priority is hereby claimed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for cleaning a wellbore with specially configured drill string mounted tools. More particularly, the present invention relates to a tool apparatus that enables debris removal tools (e.g., scraper blades, brushes or magnetic members/magnets) to be mounted to the outer cylindrically shaped surface of a section or joint of a drill string/drill pipe with a specially configured locking clamp or clamps.
2. General Background of the Invention
The Drilling of an oil well typically requires the installation into the wellbore of steel walled casing. This casing is cemented into place to provide a gas tight seal between the overlapping casing strings and also between the casing and the formation or rock through which the well is drilled. Typical cementing practice requires the cement to be pumped from the surface area or wellhead down a string of internal tubing or down the inner most casing string and displaced through the bottom of the casing string into the casing annulus. This procedure may contaminate the inside of the casing wall or wellbore with the cement. After cementation is completed, it is often required to drill out cement and the associated cementation equipment (commonly referred to as shoe track, floats shoe, landing collar, and darts).
Chemicals, solids, greases and other fluids used in the drilling process can and do adhere to the casing wall. These chemicals often mix to become a sticky and viscous substance which is largely resilient to chemical treatments and difficult to remove. As the wellbore casing is steel walled, it can and is prone to rusting and scaling. During the drilling and other downhole activities, pieces of the drilling or wellbore equipment may need to be milled. Through various other processes (purposeful or accidental), pieces or parts can be left inside the wellbore. The aforementioned situations result in contaminants being left in the wellbore, which will for the purposes of this document be referred to as debris.
During the completion phase in a well lifecycle, several pieces of hardware are semi-permanently installed into the wellbore. These vary greatly in complexity and cost. Their primary function is the transportation of produced hydrocarbons (or injection from surface of other fluids) between the reservoir and the Christmas tree /wellhead (or vice versa) as well as maintaining hydrostatic control of the wellbore at all times. Completions typically include steel tubular piping to transport the fluids, at least one hydrostatic sealing device (packer) and one safety valve. More complex completions may include gauges to measure pressure and temperature at multiple points in the wellbore. Other items may include chokes, screens, valves and pumps. Advancements in downhole electronics make the placement of measuring and controlling equipment more accessible and more commonplace.
Typically these components are sensitive to debris. It has been well documented that debris is a leading root cause of failure during completion operations. In response, a niche industry has developed since the late 1990s, which is focused on the removal of debris and the cleaning of the wellbore. This niche of the oil industry is known as wellbore cleanup. The wellbore cleanup operations will typically take place between the drilling and completion of the well.
Generally speaking, the practice of wellbore cleanup is not new. Examples of prior art go back many years when basic embodiments of wellbore cleanup tools were developed, including scrapers, brushes, magnets, junk catchers and variations thereof These were basic tools designed to fit a basic need, examples of which are still in use today.
As advancements in drilling and completion technologies were made (particularly starting in the 1990's with the inclusion of downhole electronics, sand control, intelligent completions and extended reach drilling) improvements to the design and functionality of wellbore cleanup tools were marketed, and the practice of improving the cleanliness of oil wells prior to installation of the completion components became almost standard practice.
During the wellbore cleanup operations, an assembly of tools (referred to as a bottom hole assembly or BHA) will be run into the wellbore to clean each casing section. These tools are fastened together using threaded connections located at either end of the tool. The tools or BHA are then fastened together with the drill string or work string consisting of multiple lengths of drill pipe, collars, heavy weight drill pipe, wash pipe or tubing also featuring threaded connections. These threaded connections are typically industry standard connections as defined in ANSI/API Specification 7-2 (for example 4-½″ IF/NC50 or 3-½″ IF/NC38) and commonly referred to as API connections. Also available are proprietary connections which are licensed from manufacturers of high strength drill pipe. Popular proprietary connections are supplied by NOV—Grant Prideco (eXtreme Torque, HI Torque, Turbo Torque), Hydrill (Wedge Thread) and others. The proprietary connections are often referred to as premium drill pipe connections and are typically used when higher mechanical strengths are required (e.g., torque, tensile strength, fatigue resistance, etc.) or when larger diameter drill pipe is preferred relating to the improvement of drilling hydraulics. For example, it is common now to use 5-⅞″ OD drill pipe inside 9-⅝″ casing to improve hydraulics whereas in the past it would have been more common to use 5″ drill pipe).
The table below shows some examples of drill pipe and connection combinations used for a typical casing size; however, due to the many manufacturers and standards available, there may be thousands of combinations.
Note: The Drill Pipe OD refers to the Pipe Body OD and not the maximum external of the component. The Tool Joints are always of larger diameter. Also the Casing Size is defined by the Nominal OD and the linear weight per foot. API 5-CT allows for a tolerance in the diameter and ovality. Therefore the Casing ID may vary significantly.
Casing Size
Typical Nominal
Drill Pipe
Drill Pipe
Drill Pipe
OD
Casing ID
Connections
OD
Tool Joint OD
9.625″
8.374″-8.921″
API NC50 (4-1/2″ IF)
5.0″
6.375″-6.750″
9.625″
8.374″-8.921″
TT/HT/XT50
5.0″
6.375″-6750″
9.625″
8.374″-8.921″
TT/HT/XT55
5.5″
7.0″-7375″
9.625″
8.374″-8.921″
TT/HT/XT57
5.875″
7.0″-7.375″
9.625″
8.374″-8.921″
WT50
5.0″
6.5/8″-7.0″
9.625″
8.374″-8.921″
WT54
5.5″
7″
9.625″
8.374″-8.921″
WT56
5.875″
7″-7-1/4″
Wellbore cleanup tools come in a variety of types and brand names. However, they can be categorized generally as one of the following: a scraper, brush, magnet, junk basket, debris filter, circulation sub, drift or a combination of two or more of these. These tools shall typically consist of a tool body onto which the various components can be attached. The tool body may consist of one or more pieces, but shall in all cases include threaded drill pipe connections, either API or Premium type. The tool body is typically an integral drill string component when made up into the drill string and shall bear all the tensile, torque, fatigue and pressure loading of the drill string. The tool body is typically made of steel and customized to allow attachment of the various components in order for it to function in the manner described.
Due to the many variations of drill pipe connections, the variety of casing sizes, and the many types of wellbore cleanup tools required, it would be commercially impractical for a company providing wellbore cleanup tools to stock every combination required from every customer. Therefore the practice of designing wellbore cleanup tools to cover a range of casing sizes as well as a variety of functions has become common practice, whereby the tool body can be used with interchangeable external components to cover both the size range and in some cases also to alter the function of the tool (for example from a scraper to a brush). This allows standardization of the tool body, however as the drill pipe connections are hard cut onto the tool body, a degree of standardization of the tool body connections are required. Typically this is the API drill pipe connection common to that casing size (NC50 for 9-⅝″ casing or NC38 for 7″ casing). In some cases the wellbore cleanup tool manufacturer may supply the tools with premium drill pipe connections, however for commercial reasons this is usually limited to specific projects or markets where the use of the corresponding drill pipe justifies this.
It is common for suppliers of wellbore cleanup tools to supply either individual tools or assemblies of tools where the individual tools have a type of drill pipe connection which is not the same as that used in the drill string. In this case it is common for the tools to be supplied with crossovers. Crossovers are typically short “subs” (joints of tubing) with differing connections at each end. For example, a XT-57 box thread can be at the top with an API NC50 pin at the bottom. This allows components of the drill string with non-interchangeable threaded end connections to be made up together into a singular integral drill string. Further to this, it is often practice to supply pup joints which are typically ten feet (10′) or less in length and have a profiled external diameter which matches the drill pipe and which fits into the drilling elevators and drill pipe slips to facilitate the installation and removal of the drill string into/from the wellbore in a timely fashion. There also exists pup-overs which are a combination of pup joint and crossover and which combines the functionality of both.
Wellbore cleanup tools and drill string often have mismatching threaded connections, and the wellbore cleanup tools are usually rated to lower strengths. The lower strength of the cleanup tools in effect reduces the overall strength of the drill string, which is typically rated by the strength of its weakest link. This has become an acceptable practice provided the drilling parameters do not exceed the limitations of the weakest point. The situation can arise during the cleanup operations that high torque can be observed during rotation of the drill string which results in rotation of the string being suspended. Drill string rotation is a key function of wellbore cleanup in the removal of debris from the wellbore, the lack of which significantly impacts the efficiency and effectiveness of the wellbore cleanup.
The requirement to include crossovers and pup joint into the drill string increases the number of threaded connections into the drill string which in turn increases the time and cost to deploy the drill string, increases the inspection costs and increases the likelihood of failure. The inventory of crossovers and pup joints needs to be managed, which includes storage, handling, inspections and maintenance. Due to the many types of drill pipe connections and the varying sizes, and the need to maintain sufficient inventory for multiple overlapping operations, the stocking and management of these inventories is a cost prohibitive endeavor.
BRIEF SUMMARY OF THE INVENTION
The apparatus of the present invention solves the problems confronted in the art in a simple and straightforward manner.
The present invention provides an improved wellbore cleaning method and apparatus whereby wellbore cleanup tools perform the functions of a scraper, brush, magnet and wellbore filter. The tool apparatus of the present invention provides external mounting to the drill pipe cylindrical portion in between the pipe “pin” and “box” end portions and securely attached by a special method and configuration which prevents the tools from being accidentally removed during the wellbore cleanup operations.
Drill pipe joints provide a solid tubular body with uniform diameter and external ‘tool joints’ (i.e., pin and box) of larger diameter which contain the threaded connections.
Since the tools are mounted externally to the drill pipe, there are no tool bodies as such, and therefore there is no reduction in the drill string strength through the introduction of a tool body, crossover, pup joint, and drill pipe connection. This arrangement eliminates the need to maintain an inventory of crossovers or to have stock of tool bodies with multiple threaded connections.
The wellbore cleanup tools of the present invention are designed with the principal that if one component were to fail, it would not result in the equipment coming loose from the drill pipe and being left in the wellbore.
In one embodiment the tool internal components are split longitudinally and bolted together about the drill pipe. Robust external rings of single piece construction and with robust internal threads are mated to the split internal components. This external ring covers the aforementioned bolts to prevent them from loosening. The external ring is prevented from loosening by two methods. First, the thread is orientated in such a way that rotating the drill pipe in the conventional manner (clockwise) will tighten the thread due to the friction of the tool against the casing. Secondly grub screws are backed out into internal pockets and secured with springs which prevent any movement of the external ring once secured. This arrangement works positively with the resultant centrifugal forces imparted during rotation of the string.
The tool designs of the present invention are modular and can be deployed individually or in any combination as required by a user or customer. The tools are mounted to the drill pipe body only radially and are free to rotate or move longitudinally along the pipe. They could not move past a tool joint (pin or box end) due to the larger external diameter. There can also be included in the present invention a locking device which consists of a set of toothed dogs, external threaded rings, and an internal split type clamp. When fully made up, the teeth grip the drill pipe, preventing any longitudinal movement. The purpose of this arrangement is to allow mounting of the locking device at any location on the drill pipe. This location may be above or below the mountable wellbore cleanup tools and be designed to limit the longitudinal movement of these tools which the drill string is being moved in the wellbore.
Prior art wellbore cleanup tools typically include drill pipe connections at either end, and have particular components allowing the tools to perform their designed actions, such as a scraper, brush, magnets, junk sub, debris filter or a combination thereof In the prior art, it is common practice to deploy several such tools screwed together end on end, and it is also common to include crossovers, due to frequent incompatibility between the wellbore cleanup tool connections and the drill pipe connections. To reduce handling time on the rig floor while picking up and laying down such equipment, the installation of pup joints and/or handling pups is also common practice.
The main disadvantages to the above prior art systems are as follows:
Drill String Integrity—a drill string can be analogized as being similar to a chain, being only as strong as its weakest link:
Introducing connections which are not the same as the drill string compromises the mechanical integrity of that string. Most wellbore cleanup tools are designed with API connections, which are typically of lower mechanical strength than premium drill pipe connections. As such, introducing the required crossovers to the string reduces the overall strength of the string. Many such tools include internal connections, which introduces another element of risk to overall drill string integrity. These internal connections are typically non-standard (do not conform to API). Drill pipe connections are typically made from a high strength steel, typically of higher strength than the wellbore cleanup tools. An important factor in prevention of fatigue failures of the drill string are bending strength ratios of the string and the connections. Adding additional wellbore cleanup tools as integral components may result in sub-optimal bending strength ratios at critical connections reducing the overall drill string integrity.
Rig Time—the daily operational costs of running a rig are one of the most significant cost impacts in drilling operations. Saving rig time reduces the overall cost of drilling a well, and those involved in this business know the importance the drilling operators place on time management.
Drilling rigs are designed generally to run drill pipe in an efficient manner. There are many examples of prior art where technology has been adapted or improved to reduce the time to handle the drill pipe on the drilling rig, including automated systems for handling the pipe, and for making and breaking connections. Drilling rigs are generally not well adapted to running individual tools, whether they be wellbore cleanup tools or other types, as they are of non-standard lengths and shapes. With the assistance of pulleys, cranes and winches, these are manhandled onto the rig floor and made up either individually or in short pre-made sub-assemblies. This is generally a time-consuming practice and there is also an impact on the safety of the individuals running the equipment as they are exposed to manual handling of heavy equipment, pressure, dropped objects and other hazards typical of a rig floor.
Prior art methods of installation of prior art wellbore cleanup tools typically involve the following steps:
1. Placement or ‘layout’ of the required tools onto the ‘catwalk’ (temporary storage place for drill pipe and equipment being run into or pulled out of the wellbore) using slings, cranes, and/or forklifts. Risks include exposure to dropped objects and accidental crushing from working in proximity to heavy moving equipment.
2. Installation of lifting subs or handling pups to the individual tools and/or making the tools into small sub-assemblies to reduce handling time of the rig. Risks include manual handling of heavy equipment with injuries to fingers and toes.
3. Lifting the sub-assemblies and/or tools to the rig floor using the crane, tugger lines (winches) and/or forklifts. Risks include exposure to dropped objects.
4. In the case that the tools are already made into a completed assembly with pup joints that are of the correct type, it may be possible to install the pup joint directly into the drill pipe elevators and by use of the crane/tugger lines and other devices lift the entire assembly and make it up into the drill string.
5. More commonly the tools and sub-assemblies will be picked up individually. Typically one or more joints of drill pipe (or drill collars) will be suspended in the elevators with the lower pin connection around shoulder height on the rig floor. Alternatively a ‘lifting sub’ may be suspended in the elevators which has an external upset and a pin connection facing down typically compatible with the tools which shall be suspended from it.
6. Depending on the design of the BHA and drill string, there may be either drill pipe, or drill collars suspended from the rotary table by slips. The use of either type requires specialized ‘slips’ and possibly the installation of a ‘dog collar’ (a safety device designed to catch the string should the drill collar slips fail). There may be no lower string, in which case a bit or mill will be installed at the end of the wellbore cleanup BHA.
7. The sub-assemblies or tools are picked up one at a time using winches and the connections made up manually to the drill string. This is a time consuming process which involves the manual use of chain/strap wenches, pipe wenches, drill collar slips, dog collars and hammers. Each connection is also ‘torqued’ using either the semi-manual pipe tongs or using an automated unit such as a ‘mechanical rough neck’ before being lowered into the wellbore.
8. This process presents a risk to personnel as it involves multiple persons working with heavy equipment in close proximity. Drill pipe tongs and associated equipment are notorious for causing injuries to fingers while being used or causing crushing injuries when being handled or swinging free.
9. A further risk is accidental dropping of the string during make-up. Most tools typically come with ‘slick’ tool joints (no external upset) and are often shorter than ideal to allow safe installation of the drill collar type slips and the necessary dog collar. Drill collar slips rely on friction to suspend the drill string and are typically less reliable than drill pipe slips which suspend the string from an upset. If the drill collar were to fail and the dog collar not to hold, then the string would be dropped and free-fall into the wellbore resulting in a costly retrieval (fishing) operation.
Drilling operations are often conducted in remote locations, whether on land, or at sea. Often drilling may take place in countries with limited operational support bases, requiring equipment to be transported to and from the rig over vast distances requiring the use of air, land and sea transportation. Compounding this issue, downhole oilfield equipment tends to be elongated and heavy, requiring specialized baskets to deliver the equipment to the rig site as well as special boats with large deck space. These baskets can be as long as 40 ft. Furthermore, transportation of equipment by air is expensive due to length and weight of equipment and there is typically a premium to be paid to transport such equipment. Offshore drilling rigs have limited deck space to store equipment and minimizing the use of deck space is important to efficient operations. Servicing of the equipment at a logistics base is a labor intense process and requires specialized equipment, trained operators as well as access to third party inspectors.
The application of the invention in the method outlined in the following steps mitigates, eliminates or improves the problems listed above in the following manner.
1. Drill String Integrity—The wellbore cleanup tools as disclosed are externally mounted and secured to the drill pipe without the use of tool bodies. The drill string integrity remains intact as there are no inclusions of additional integral components and therefore no reduction in the integrity of the drill string.
2. Rig Time—The wellbore cleanup tools can be mounted to a single joint of drill pipe at the rig site. This action can be completed on the deck or catwalk away from the main area of operation. When required to be run in the hole, the single joint can be picked up to the rig floor either using the rig's automated systems or in the same manner as running a single joint from the catwalk or mouse-hole which would be the same method used when picking up single joints of drill pipe. It would also be possible to rack the joint in the derrick as part of a stand of pipe in the same manner as the other drill pipe stands are racked.
3. Logistics—As the wellbore cleanup tools do not have tool bodies, and are not required to be made into sub-assemblies prior to shipping, it is possible to ship them in short containers, without the need for the elongated basket typically used to ship other types of tools. This reduces the burden on the deck space onboard the rigs, supply boats and trucks. Furthermore, it reduces the cost of air transportation as the shipping boxes are no longer required to be elongated.
4. Safety—The use of this technology eliminates the need to perform single or sub-assembly pickups on the rig floor, which reduces exposure to common hazards of working on a rig floor such as finger injuries and crushing injuries while using the manual and semi-automated tools and equipment.
The following method describes the general application of one embodiment of attaching a mountable wellbore cleanup tool of the present invention to a joint of drill pipe on a rig location.
1. Begin with a single joint or section of drill pipe which is identical to the joints of drill pipe that comprise the drill string which is to be deployed in the wellbore.
2. Attach a support sleeve, which consists of two or more mated and largely identical pieces split longitudinally, about the drill pipe. These pieces when mated shall make a complete concentric part. The support sleeve can have an internal diameter slightly larger than the external diameter of the drill pipe body to permit rotation of the support sleeve relative to the drill pipe. The internal diameter of the support sleeve can be less than the external diameter of the drill pipe tool joints, such that the support sleeve can be abutted against the tool joint to limit the longitudinal movement of the support sleeve relative to the drill pipe.
3. The pieces of the support sleeve are mated using bolts, pins, hinges, or similar screw type fasteners. Depending on the configuration of the tools, either scraper, brush or magnetic elements may be attached to the support sleeve.
4. Typically the fasteners which secure the support sleeve together may not be of sufficient strength alone to prevent accidental detachment of the support sleeve downhole with disastrous effect. It is therefore necessary to install a plurality of centralizer rings to the support sleeve, which are to be inserted (slide) over the ends of the drill pipe tool joints. These centralizer rings can be of singular piece construction for strength. The internal diameters of the centralizer rings can be slightly larger than the external diameter of the drill pipe tool joints. The centralizer rings can be threaded internally and mated to an external thread on the support sleeve. Alternatively they may be secured to the support sleeve using bolts, pins, or screws and a combination of these fasteners/methods. Once installed, the centralizer rings shall completely or partially cover the fasteners used to mate the support sleeve pieces (e.g. halves) to prevent them from accidentally being removed.
5. To prevent the support sleeve and the assembled components from traveling longitudinally relative to the drill pipe it is necessary to install a locking clamp assembly. Once installed, the support sleeve and assembled components shall abut against the locking clamp at one end and can abut against a drill pipe tool joint at the other, thus preventing any longitudinal movement relative to the drill pipe. Alternatively, two locking clamps can be used to secure the support sleeve and assembled components.
6. To install the locking clamp to the drill pipe, the split slip ring is installed about the drill pipe body. This consists of a plurality of near identical pieces which when mated together make a concentric component. The internal diameter of the split slip ring is slightly larger than the drill pipe body to allow it to be installed and moved into position. The split slip ring pieces are mated using bolts, pins, hinges or similar screw type fasteners.
7. A plurality of slip segments are installed into or adjacent to the split slip ring. The slip segments have an internal profile which matches the external diameter of the drill pipe body and includes a toothed or serrated surface which engages the drill pipe body and prevents longitudinal and rotational movement once sufficient collapsing force is applied. The external profile of the slip segments is conical such that when a mated external component applies a longitudinal force, this conical section converts this force into a collapsing force using the mechanical advantage of the conic shape.
8. A plurality of slip cone rings are installed over the slip segments with an internal conical mating profile to engage the slip segment.
9. To complete the installation of the locking clamp, a tensioner sleeve is slid over the drill pipe tool joints and engaged by a thread to the split slip ring. This can be of singular piece construction. As the tensioner sleeve thread is tightened, it drives the slip cone rings longitudinally which in turn engage the slip segments, which in turn engage the drill pipe body. The tensioner sleeve internal diameter is slightly larger than the drill pipe tool joints to allow installation from one end.
10. The drill pipe single joint complete with installed mountable wellbore cleanup tool can then be picked up to the rig floor by whatever methods are employed upon that particular rig. This may include laying the single joint on the catwalk, placing it in the mouse-hole, making it up to a stand, or racking it in the derrick.
11. After completion of the wellbore cleanup operations, the installation process is reversed. The components can be stored back in their box for later operations or returned to the supply base.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
FIG. 1 is an elevation view of a normal drilling operation showing the handling of drill pipe;
FIGS. 2-4 are elevation views illustrating the method of the present invention and showing the mountable wellbore cleanup tool apparatus of the present invention as part of drilling operations;
FIG. 5 is a perspective view of the preferred embodiment of the apparatus of the present invention;
FIG. 6 is an exploded perspective view of the preferred embodiment of the apparatus of the present invention;
FIG. 7 is a partial sectional elevational view of the preferred embodiment of the apparatus of the present invention;
FIG. 8 is a sectional view taken along lines E-E of FIG. 7 ;
FIG. 9 is a sectional view taken along lines F-F of FIG. 7 ;
FIG. 10 is a sectional view taken along lines G-G of FIG. 7 ;
FIG. 11 is a partial perspective view of the preferred embodiment of the present invention showing a centralizer ring;
FIG. 12 is a partial exploded perspective view of the preferred embodiment of the apparatus of the present invention showing a locking clamp;
FIG. 13 is a perspective view of the locking clamp of FIG. 12 ;
FIG. 14 is a sectional view of the locking clamp portion of the preferred embodiment of the apparatus of the present invention;
FIG. 15 is a sectional view taken along lines A-A of FIG. 13 ;
FIG. 16 is an exploded perspective view of the preferred embodiment of the apparatus of the present invention showing the debris removing tool in the form of a mountable scraper;
FIG. 17 is an exploded perspective view of the preferred embodiment of the apparatus of the present invention illustrating a mountable scraper tool;
FIG. 18 is a perspective view of the mountable scraper tool of FIGS. 15 and 16 ;
FIG. 19 is a sectional view of the mountable scraper tool of FIGS. 16 through 18 ;
FIG. 20 is a sectional view taken along lines A-A of FIG. 19 ;
FIG. 21 is a sectional view taken along lines B-B of FIG. 19 ;
FIG. 22 shows a perspective view of a preferred scraper broach;
FIG. 23 shows various broach arrangements;
FIG. 24 is a perspective view showing a brush type broach;
FIG. 25 is a sectional view showing a broach concentric ID construction;
FIG. 26 is a sectional view showing a broach eccentric broach construction;
FIG. 27 is an exploded perspective view of the preferred embodiment of the apparatus of the present invention showing a mountable brush tool;
FIG. 28 is a perspective view of the preferred embodiment of the apparatus of the present invention showing a mountable brush tool;
FIG. 29 is a sectional view of the mountable brush tool of FIGS. 27 and 28 ;
FIG. 30 is a sectional view taken along lines C-C of FIG. 29 ;
FIG. 31 is a sectional view taken along lines D-D of FIG. 29 ;
FIG. 32 is a sectional view showing an alternate embodiment where the centralizers are an integral component of the split housing;
FIG. 33 is another alternate embodiment with free rotating centralizers and different locking methods;
FIG. 34 is a sectional view showing an alternate centralizer that is attached with grub screws;
FIG. 35 is a sectional view showing centralizers attached with a spline;
FIGS. 36A-36C are sectional views showing various secondary attachment methods;
FIGS. 37A-37C are sectional views showing various brush insert attachment methods;
FIG. 38 is a sectional view showing a generic mountable well brush cleanup tool having a split housing;
FIG. 39 is a sectional view showing a cleanup tool having a hinged housing;
FIG. 40 is an end view showing a cleanup tool having a hinged housing; and
FIG. 41 is a sectional view of a wellbore cleanup tool having a customized tool mandrel.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-10 show the preferred embodiment of the apparatus of the present invention designated generally by the numeral 20 (see for example, FIGS. 2, 6 ). FIGS. 1-4 illustrate the method of the present invention. In FIGS. 1-4 , a derrick 1 is shown having a block 2 and elevator 3 . The derrick 1 can be provided with a tugger line 4 . In FIGS. 1-3 there is shown a rotary table with slips designated by the numeral 5 . Finger boards 6 and mouse hole 7 can be used to store individual drill pipe joints or sections 12 . A mouse hole 7 can be used to store a drill pipe joint 12 that can then be lifted using tugger line 4 as shown in FIG. 1 . Individual joints of drill pipe 12 are stored on catwalk 9 . These joints 12 can be moved as indicated by arrows 13 , 14 to Vee door 8 and then to the derrick platform 17 . In FIGS. 1-4 , a wellbore 10 is shown. Drill string 11 is shown being lowered into wellbore 10 . The drill string 11 is comprised of drill pipe joints 12 connected end to end. In FIG. 1 , the drill string 11 is supported by the rotary table with slips 5 .
The tool apparatus 20 provides a tool assembly 15 which can be mounted to a standard, commercially available drill pipe joint or section 12 as will be described more fully hereinafter. In FIG. 1 , arrows 13 , 14 illustrate the travel of a drill pipe joint or section 12 from catwalk 9 to platform 17 . FIGS. 2, 3 and 4 illustrate the travel path of a joint of drill pipe 12 fitted with tool assembly 15 as it travels from catwalk 9 ( FIG. 2 ) to the platform 17 (see FIG. 3 ) and into the wellbore 10 (see FIG. 4 ). In FIG. 4 , the tool assembly 15 mounted on a drill pipe joint or section 12 is shown as part of the drill string 11 . FIG. 3 illustrates that the tool apparatus 20 (which includes the tool assembly 15 and a joint of drill pipe 12 ) can be placed in the mouse hole 7 , or finger boards 6 , or gripped by the block 2 and elevator 3 or placed in the mouse hole 7 prior to being lowed into wellbore 10 .
FIGS. 5-10 show tool assembly 15 and tool apparatus 20 in more detail. The tool apparatus 20 is shown in FIGS. 5-10 with tool assembly 15 mounted to drill pipe joint or section 12 and more particularly to the cylindrically shaped portion 23 , which has a cylindrical outer surface 24 . Each drill pipe joint or section 12 can provide connector end portions 21 , 22 such as a pin end portion 21 and a box end portion 22 . In between the pin end portion 21 and the box end portion 22 is cylindrical portion 23 having cylindrically shaped outer surface 24 to which tool assembly 15 is attached.
In one embodiment, tool assembly 15 can be mounted to cylindrical portion 23 in between a connector end portion 21 , 22 and a locking clamp 28 (see FIG. 5 ). However, it should be understood that the tool assembly 15 could be mounted in between a pair of locking clamps 28 which are both spaced away from either connector end portion 21 or 22 .
Tool assembly 15 provides a support sleeve 25 . The support sleeve 25 has sleeve halves 26 , 27 (see FIGS. 7-11 ). Centralizer rings 29 are provided at each end portion of support sleeve 25 and attached thereto with threaded connections 31 . The sleeve halves 26 , 27 can be connected together using bolts or bolted connections 30 . In FIG. 7 , split bearings 32 are shown attached to each end portion of support sleeve 25 . Compression springs 33 are provided in between support sleeve 25 and centralizer ring 29 at each end portion of tool assembly 15 . One or more recesses or sockets 34 are provided in between each centralizer ring 29 and support sleeve 25 . These recesses or sockets 34 are receptive of conical spring 36 and grub screw 35 . The grub screw 35 can be tightened to occupy recess or socket 34 of sleeve 25 .
Once centralizer ring 29 is threaded upon the external threads 37 of support sleeve 25 , a threaded connection 31 is perfected between centralizer ring 29 and support sleeve 25 . Grub screw 35 is spring loaded using conical spring 36 . After the threaded connection 31 is perfected, the grub screw 35 can be backed out slightly to engage a correspondingly shaped recess or socket 43 on centralizer ring 29 (see FIGS. 7, 11 ). The threaded connection 31 is thus perfected by engaging the external threads 37 of sleeve 25 with the internal threads 38 of centralizer ring 29 .
A plurality of magnets 40 are mounted to magnet spacers 41 and magnet internal support sleeve 39 . The support sleeve 25 has minimal thickness sections 42 that cover the magnets 40 as shown in FIG. 9 .
FIGS. 13-18 show locking clamp 28 in more detail. Locking clamp 28 has a plurality of slip segments 45 that are circumferentially spaced around pipe joint 12 cylindrical portion 23 . A split cone ring 46 provides two portions that engage and surround the plurality of slip segments 45 as shown in FIGS. 13, 15 and 17 . A split slip ring 47 can be a two part ring that forms a connection at interlocking connection 56 with each slip segment 45 . Thus, each slip segment 45 is installed into a mating groove of the split slip ring 47 as shown. Bolted connections or bolts 48 connect the segments 53 , 54 of the split slip ring 47 together. Each of the segments 53 , 54 has openings 55 that receive bolts or bolted connections 48 and internally threaded openings 60 that engage the threaded end portion of a bolt 48 as shown in FIGS. 13-14, 16 and 18 .
A snap ring 49 is placed in between split slip ring 47 and tensioner sleeve 50 . Annular grooves can be provided on the outside surface of split slip ring 47 and on the inside surface of tensioner sleeve 50 . In FIG. 13 , the numeral 63 designates the annular groove on the outside surface of each segment 53 , 54 of split slip ring 47 . In FIG. 12 , the numeral 64 designates the annular groove 64 on the inside surface of tensioner sleeve 50 .
Each of the slips or slip segments 45 has an inner toothed portion 51 that grips the cylindrical outer surface 24 of cylindrical portion 23 of drill pipe joint 12 . A gap 52 is provided in between each of the slip segments 45 (see FIG. 12 ). A threaded connection 57 is formed between the external threads 58 of split slip ring 47 and the internal threads 59 of tensioner sleeve 50 . Correspondingly shaped and sized annular shoulders are provided on split cone ring 46 and tensioner sleeve 50 . In FIG. 14 , split cone ring 46 has annular shoulder 61 . Tensioner sleeve 50 has annular shoulder 62 .
FIGS. 16-22 show a scraper or broach tool designated generally by the numeral 65 . FIG. 22 shows perspective views of a scraper broach 70 . As with the preferred embodiment, the scraper tool 65 provides a support sleeve 66 which can be a split support sleeve having sleeve halves 67 , 68 . External split bearings 69 attach to the support sleeve 66 as shown in FIGS. 22 and 25 . Centralizer rings 29 connect to the support sleeve 66 with threaded connections as with the preferred embodiment. The support sleeve 66 thus provides external thread 71 (see FIG. 17 ). The centralizer rings 29 provide internal threads 38 (see FIG. 11 ). A scraper or broach 70 is a cleaning member that attaches to the outer surface of support sleeve 66 , being held in position by the centralizer rings 29 which overlap it as seen in FIGS. 22 and 25 . C-rings 72 are provided in between support sleeve 66 and centralizers 29 as shown. Also provided between centralizer rings 29 and support sleeve 66 are spring support ring 78 and compression spring 75 . As with the preferred embodiment, grub screws 35 and conical springs 36 can be used to complete the connection between the centralizer ring 29 and support sleeve 66 . External split bearings 69 form an interlocking connection with support sleeve 66 at interlocking connection 76 . Snap ring 77 can be placed in between external split bearing 69 and centralizer 29 .
Pins 74 attaches to sleeve 66 and to broach or scraper 70 as shown in FIGS. 19 through 22 . Pins 74 attached to corresponding holes 93 on scraper broach 70 . Pins 74 are attached to the support sleeve 66 by welding and become an integral part of the support sleeve 66 .
FIGS. 22-26 show various scraper and brush type broaches. In FIG. 24 , three different configurations of longitudinal cuts are shown for a broach 89 . These can include helical longitudinal cut 90 , straight longitudinal cut 91 and tortuous longitudinal cut 92 . FIG. 24 shows a brush type broach 89 . FIG. 25 illustrates a concentric ID for the broach 89 whereas FIG. 26 shows an eccentric ID for the broach 89 . In FIG. 22 , the broach 89 is shown having a mating hole 93 for a pin 74 , scraper teeth 94 and helical bypass grooves 95 . The longitudinal cut 90 is shown in FIG. 22 . However, it should be understood that the FIG. 22 configuration could have the straight longitudinal cut 91 or the tortuous longitudinal cut 92 of FIG. 23 .
FIGS. 27-31 show a brush tool 80 that can be used to brush the wellbore. Brush tool 80 provides a support sleeve 81 that has a helical split 87 as shown in FIG. 27 . Support sleeve 81 has split bearings 82 at its end portion (see FIG. 29 ). Each end portion of support sleeve 81 has external threaded sections 86 for forming a connection with a centralizer ring 29 as with the earlier embodiments (see FIG. 27 ). Grub screws 35 and conical springs 36 can be used to form a connection between the support sleeve 81 and centralizer ring s 29 as shown in FIGS. 23 and 25 . Compression spring 83 is placed in between centralizer ring 29 and sleeve 81 at interlocking connection 88 which can be in the form of correspondingly shaped annular shoulders provided on both the sleeve 81 and centralizer 29 . Compression spring 83 is provided in between the annual shoulders at the interlocking connection 88 as shown in FIG. 29 .
A plurality of brush segments 84 are mounted to support sleeve 81 at provided mating grooves 85 (see FIGS. 28 and 29 ).
FIG. 32 provides a sectional view of a wellbore cleaning tool having integral centralizers which are non-rotating. The well cleaning tool 96 of FIG. 32 is shown mounted to drill pipe section 12 . The well cleaning tool 96 provides a split housing or split support sleeve 97 having integral centralizers 98 . Cleaning members 99 , such as a brush, scraper and/or magnet are mounted to the split housing or support sleeve 97 . External rings 100 are provided. The split housing or split support sleeve 97 is placed on drill pipe 12 in between locking clamps 28 .
FIG. 33 shows an additional embodiment of the apparatus of the present invention which provides free rotating centralizers or centralizer rings 103 . Well cleaning tool 101 has a split housing 102 to which is affixed cleaning members 104 . Bolted connections 30 can be used to secure the halves of the split housing together as with the preferred and other embodiments. The centralizer rings 103 engage the outer surface of the split housing 102 and are held in position with a locking ring 105 or 106 . The locking ring 105 is a threaded type that engages threads provided on the split housing 102 . The locking ring 106 is a lock wire type. Cleaning members 99 , such as a brush, scraper and/or magnet are mounted to the split housing or support sleeve 97 .
FIG. 34 shows a well cleaning tool designated generally by the numeral 110 . The well cleaning tool 110 provides centralizers that are attached with grub screws 35 . In FIG. 34 , split housing 111 carries cleaning members 112 . External rings 113 are secured to split housing 111 using grub screws 35 and conical springs 36 . Split housing 111 can provide a recess or socket portion 114 that aligns generally with the recessed or socket portion 115 on external ring 113 . The aligned recesses or sockets 114 , 115 can be occupied with a grub screw 35 and conical spring 36 .
FIG. 35 shows a well cleaning tool 116 wherein centralizers are attached with a spline. In FIG. 35 there is provided well cleaning tool 116 which has a split housing 117 that carries a plurality of cleaning members 118 . External centralizer rings 119 are attached to split housing 117 with splines 120 . Locking clamps 28 are placed on either side of split housing 117 to maintain its position upon drill pipe joint 12 .
FIGS. 36A through 36C show a well cleaning tool 121 with various secondary attachment methods. FIG. 36A shows a version of the secondary attachment method of the external ring to the slip housing using grub screws. FIG. 36B shows a version of the secondary attachment method of the external ring to the slip housing using a snap ring. FIG. 36C shows a secondary attachment method of the external ring to the slip housing using a locking ring and lock wire. In FIGS. 36A, 36B, and 36C there are seen split housing 123 , external rings 122 , cleaning members 124 and locking clamps 28 . Bolted connections 30 are also shown for holding the locking clamp 28 to the drill pipe 12 as well as for securing the split housing 123 to the drill pipe 12 .
In FIG. 36A , the secondary attachment method is in the form of grub screws 35 . The grub screws 35 can be provided with conical springs 36 .
In FIG. 36B , the secondary attachment method of the external ring 122 to the slip housing 123 using a snap ring 125 .
In FIG. 36C , the second method of attaching the external ring to the slip housing uses a locking ring and lock wire 126 .
FIGS. 37A through 37C show various brush insert and attachment methods on a well cleaning tool 130 . In FIG. 37A , a dove tail groove and crimped style brush insert is shown designated as 131 . In FIG. 37B , a crimped bullet style brush insert is designated by the numeral 132 . In FIG. 37C , a stuffed style brush insert is shown, designated by the numeral 133 . In each of the FIGS. 37A, 37B , there can also be seen locking clamp 28 , a split housing 134 and external centralizer rings 135 . It should be understood that any of the brush inserts of FIGS. 37A, 37B, 37C can be used with any embodiment of the brush tool.
FIG. 38 shows a generic mountable wellbore cleaning tool designated by the numeral 140 . The well cleaning tool 140 provides a split housing 141 , cleaning member or members 142 , external rings 143 , locking clamps 28 and bolts or bolted connections 30 .
FIGS. 39 and 40 show the well cleaning tool that provides a hinged housing. Well cleaning tool 145 is attached to a section of drill pipe 12 using split housing 146 that includes a pair of halves 147 , 148 . The split housing halves 147 , 148 are pivotally attached at hinge 149 and are connectable using bolted connections 30 . As with other embodiments, the well cleaning tool 145 provides cleaning members 150 , external rings 151 , bolted connections 30 , and locking clamps 28 .
FIG. 41 shows a well cleaning tool 155 that is shown attached to a customized tool mandrel 156 . In FIG. 50 there is provided tool mandrel 156 holding split housing 157 . Shown on split housing 157 are cleaning members 158 and external rings 159 .
The following is a list of Reference Numerals used in the present invention:
LIST OF REFERENCE NUMERALS:
REFERENCE
NUMBER
DESCRIPTION
1
derrick
2
block
3
elevator
4
tugger line
5
rotary table with slips
6
finger boards
7
mouse hole
8
Vee door
9
catwalk
10
wellbore
11
drill string
12
drill pipe joint/section
13
arrow
14
arrow
15
tool assembly
16
arrow
17
platform
18
arrow
19
arrow
20
tool apparatus
21
pin end portion/connector end portion
22
box end portion/connector end portion
23
cylindrical portion/connector end
portion
24
cylindrical outer surface
25
support sleeve
26
sleeve half
27
sleeve half
28
locking clamp
29
centralizer ring
30
bolt/bolted connection
31
threaded connection
32
split bearing
33
compression spring
34
recess/socket
35
grub screw
36
conical spring
37
external threads
38
internal threads
39
magnet internal support sleeve
40
magnet
41
magnet spacer
42
minimal thickness section
43
socket/recess/bolt hole
44
bypass slot
45
slip segment
46
split cone ring
47
split slip ring
48
bolt/bolted connection
49
snap ring
50
tensioner sleeve
51
toothed portion
52
gap
53
segment
54
segment
55
opening
56
interlocking connection
57
threaded connection
58
external threads
59
internal threads
60
internally threaded opening
61
annular shoulder
62
annular shoulder
63
annular groove
64
annular groove
65
scraper tool
66
support sleeve
67
sleeve half
68
sleeve half
69
external split bearing
70
scraper/broach
71
external thread
72
C-ring
73
split bearing
74
pin
75
compression spring
76
interlocking connection
77
snap ring
78
spring support ring
79
annular end portion
80
brush tool
81
support sleeve
82
split bearing
83
compression spring
84
brush segment
85
mating groove
86
external thread
87
helical split
88
interlocking connection
89
broach
90
helical longitudinal cut
91
straight longitudinal cut
92
tortuous longitudinal cut
93
hole
94
scraper teeth
95
helical bypass groove
96
well cleaning tool
97
split housing/support sleeve
98
integral centralizer
99
cleaning member
100
external ring
101
well cleaning tool
102
split housing
103
centralizer ring
104
cleaning member
105
locking ring, threaded type
106
locking ring, lock wire type
110
well cleaning tool
111
split housing
112
cleaning member
113
external ring
114
recess/socket
115
recess/socket
116
well cleaning tool
117
split housing
118
cleaning member
119
external centralizer ring
120
spline
121
well cleaning tool
122
external ring
123
split housing
124
cleaning member
125
snap ring
126
locking ring/lock wire
130
well cleaning tool
131
dovetailed and crimped style brush
insert
132
bullet style brush insert
133
stuffed style brush insert
134
split housing
135
external centralizer ring
140
well cleaning tool
141
split housing
142
cleaning member
143
external ring
145
well cleaning tool
146
split housing
147
half
148
half
149
hinge
150
cleaning member
151
external ring
155
well cleaning tool
156
tool mandrel
157
split housing
158
cleaning member
159
external ring
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims. | A drill pipe mountable wellbore cleaning tool apparatus is of an improved configuration that enables attachment to a drill pipe joint having first and second connector end portions and a cylindrically shaped portion in between the connector end portions. The drill pipe joint with attached debris cleaning tool or tools is made part of a drill string. The apparatus includes a support sleeve that is mounted to the drill pipe joint in between the connector end portions. The support sleeve abuts but does not invade the integrity of the cylindrical portion. Centralizers are attached to the opposing ends of the support sleeve, with each centralizer overlapping a portion of the support sleeve. The support sleeve carries one or more debris cleaning tools in between the centralizers. These tools enable debris to be removed from a wellbore. At least one locking clamp is attached to the cylindrical portion next to a said centralizer. | 4 |
BACKGROUND OF THE INVENTION
Persons visiting beach areas often carry with them a variety of equipment and supplies which may be both heavy and awkward to handle while traversing pavement, walkway, stair and sandy beach surfaces and which preferably are most conveniently used by setting some of the equipment or supplies on a table top. The present invention provides a combined table/dolly/sled carrier structure which can be conveniently used to transport a variety of equipment and supplies in such a situation.
SUMMARY OF THE INVENTION
In accordance with the present invention a wooden table structure having legs suitable for supporting it on a sandy beach has incorporated therein a plurality of relatively small diameter recessed wheels which project only slightly above the broad smooth flat top surface of the table whereby when the table is inverted, the top surface provides a sliding surface for sliding it upon a sandy surface and the wheels provide rolling support on a hard walkway or sheet surface while this carrier structure transports equipment or supplies thereon over such surfaces. Except for the slight projection of the wheels above the broad smooth flat surface of the structure, this surface is unobstructed. The recessed wheels provide minimal interference with the sliding movement of the structure when it is used as a sled on a sandy surface. The wheels are supported in apertures in the top surface and may be the same type of wheels used on skateboards or rollerskates, and which are typically constructed from a resilient abrasion resistant polyurethane plastic material. The wheels are easily manually removable to further minimize any obstruction of the top surface when the structure is used as a table. A rigid handle is detachably connected at one end of the structure to pull the structure in its transporting mode of use. To facilitate movement of heavy loads on hard surfaces the wheels at one end of the structure may be mounted to swivel using conventional small swiveling casters. The table legs are hingedly mounted relative to the table top so they can be compactly folded against the top for storage or transporting the table in the trunk of an automobile. The leg assemblies in their extended positions serve as front and rear stops to help retain loads on the carrier during transporting of the loads. The removable handle is stored in clips at the underside of the table when not in use.
It is an object of the invention to provide a multipurpose transporting device for movement of material over both loose granular and hard flat surfaces.
It is a further object of the present invention to provide such a multipurpose device which can also function as a table on a sandy beach or other surface.
Another object of the invention is to provide a transporting device which is useful around a home for transporting heavy objects as in a basement.
Still another object of the invention is to provide a device which is useful in carrying heavy or awkward loads to and from an ice fishing site on a frozen lake which may be partially snowcovered.
A further object of the invention is to provide a transporting device which is low cost and made of relatively few simple or off the shelf parts.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a sled/dolly/table device in a position for carrying a load by sliding or rolling movement over a supporting surface.
FIG. 2 is a perspective view of the sled/dolly/table device arranged for use as a table.
FIG. 3 is a section taken through a wheel mounting assembly parallel to the wheel axis.
FIG. 4 is a view of a spring clip for retaining a wheel on the end of its axle as seen in FIG. 3.
FIG. 5 is a perspective view of a clip used for storage of a handle beneath the table top.
FIG. 6 is a perspective view of a detachable handle for pulling the structure as seen in FIG. 1.
FIG. 7 is a perspective view of a bracket secured to the underside of the table top at one end for attachment of a pulling handle.
FIG. 8 is a section showing a portion of the upper left leg structure of FIG. 1 in which the leg is in its extended position.
FIG. 9 is a side view of the sled/dolly/table device with the wheels and smooth surface of the table at the underside.
FIG. 10 is a plan view of the table top.
FIG. 11 is a side view of FIG. 10 with the legs folded to their retracted positions.
FIG. 12 is a view of the underside of FIG. 11 or the top side of FIG. 9 with the pulling handle shown in its stowed position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a table/dolly/sled in accordance with the present invention is shown in its position for use as a dolly or sled and comprises a flat generally rectangular plate-like member having a broad smooth bottom surface which is raised or spaced at a substantial distance from the ground surface which becomes a top table surface when assuming the position shown in FIG. 2. Extending end to end on the upper surface as seen in FIG. 1 are two parallel rails 6 which are secured to the plate member 1 for strengthening and rigidizing or stiffening it. The rails are located near the outer elongated edges of the plate member 1 and secure wheels assemblies to the plate and provide pivotable support for leg structures which enable the device to be inverted and used as a table as seen in FIG. 2.
The table leg structures comprise four legs 4 in two pairs at opposite ends of the device. The legs 4 of each pair are interconnected by a pair of cross braces 3 and a further reinforcing cross bar 5 between the ends of the legs. The brace 3 and bar 5 at the ends of the legs provide a large flotation area to keep the legs from sinking into loose sand when the device is used as a table on a beach.
As seen in FIG. 8, each leg is pivotably supported on a respective rail 6 by means of a flat-headed bolt 16 having an unthreaded portion extending through coaxial holes in the leg 4 and in the rail 6 with a short threaded portion extending beyond the rail 6 with a washer and self-locking nut secured thereon. The unthreaded portions of bolt 16 within the parts 4 and 6 reduce the wear in the holes of these members which would occur in the case of threaded bolt portions in these holes. The counterclockwise pivoted movement of the leg 4 as seen in FIG. 8 is limited by engagement of the lower end of the leg with the upper surface of the plate 1 and by engagement of the cross bar 3 with the upper surface of the rail 6.
As seen in FIGS. 1, 3 and 12 the wheels 9 are supported on the ends of removable axles 10. The free-floating axle 10 is held close and parallel to the plate 1 at each side of the carrier in a notch in the side of rail 6 which faces the plate 1 as seen in FIG. 3. Each wheel is located in an aperture in the plate 1 so that its lower or rolling surface extends only a slight distance below the lower sliding surface of the plate 1. Except for the slight projection of the wheels from the broad smooth flat sliding surface, this surface is unobstructed. Each wheel is spaced from the rail 6 and the inner edge of the aperture in plate 1 by a friction reducing washer 11. Each wheel is retained on the end of the axle by a spacing collar which in turn is held in place by a spring clip having one part extending through a transverse hole in the axle and another part engaging the outer surface of the axle to retain the clip in the position shown in FIG. 3. The wheels are provided with bearings 13 to reduce rolling friction thereat.
At the forward topside of the device as seen in FIGS. 1 and 12 is mounted a metal towing bracket 7 as seen in FIG. 7. This bracket is bolted to the plate 1 and has a raised forwardly projecting tongue 7' with a hole therein to receive a hook portion at one end of an elongated T-shaped metal pulling handle 15 shown in FIG. 6. The handle is removable from the tongue 7' by manipulating a spring biased slide member 15' to open the hook for removal from the hole in tongue 7'. Upon removal the handle may be stowed in spring clips 17, of a configuration shown in FIG. 5, secured between the rails 6 as seen in FIG. 12.
The table top has a plurality of annular recesses 8 in its top surface to retain therein tapered food or beverage containers when the device is functioning as a table. If desired, these recesses can be provided with underlying plates suspended a short distance, approximating the height of rails 6, below the plate 1 to hold in the recesses containers which do not precisely fit the annular recesses for retention therein.
The table top dimensions are approximately 20 by 42 inches with a thickness of the plate 1 of 1/2 inch. Plate 6 is made from a sturdy weatherproof plywood. The rails 6 are about 11/4 inches thick and 21/2 inches high.
The wheels for the device are preferably rollerskate or skateboard wheels having diameters in the range from approximately 55 to 72 millimeters and are mounted on steel axles of 7 or 8 millimeters diameter. With an axle of 8 millimeters diameter this range of wheel diameters provides projections of the wheels above the sliding surface of the plate 1 in a range of approximately 11 to 20 millimeters.
A hole 2 is provided in the center rear portion of the plate 1 to enable two carriers to be tied together end to end using a line passing through the hole 2 and the hole in the bracket tongue 7'.
The rails 6 and the parts 3-5 of the leg assemblies are made of a strong hardwood and are secured together in the illustrated configuration using screw or bolt fasteners. The rails are similarly secured to the plate 1 with such fasteners having flat heads in countersunk recesses in the plate 1 so that the heads are flush with the smooth sliding surface of the plate. To provide further strength, a water resistant epoxy or other adhesive may be used where non-movable wood surfaces abut each other. The wood parts are finished with a suitable wear and weather resistant coating. The sliding surface may be covered with a layer of high density polyethylene plastic or similar material with a high degree of abrasion resistance a low coeficient of friction.
To facilitate carrying the carrier device up or down stairs, elongated bars, extending beyond both ends of the carrier, may be passed beneath the upper or lower bars 3 of the leg assemblies so that the carrier can be carried like a stretcher. The elongated bars as well as the transverse bars 3 may have mating notches to keep the parts from sliding relative to each other while carrying a load, particularly when the carrier is tilted slightly from side-to-side or end-to-end.
To further facilitate sliding movement of the carrier over sand, the front edge of the plate 1 may be upwardly bevelled, bent or inclined with respect to the bottom sliding surface. The rails may be beveled or shaped to accommodate and support such an inclined portion of approximately 2 to 3 inches which may be mitered to the main portion of the plate 1 at an angle of approximately 30 degrees, for example.
The wheels at the front end of the carrier when mounted on a single fixed axle as shown make it difficult to use the device as a dolly for a heavy load in a small space such as in a basement. In such case one centrally located front wheel or two front wheels spaced laterally as shown can each be supported in a box depending from the top plate 1 between the rails 6 or alongside thereof. A box for a centrally located swiveling wheel may be located at the location of the bracket 7 and may have an apertured tongue extension cut and bent out of a side thereof serving the function of tongue 7'. Such a box may be a five-sided metal generally cubical box with flanges around its one open side to secure it to the plate 1. One of the rails 6 and plate 1 may form two sides of such a box. A conventional swiveled wheel with a flat mounting plate normal to the swiveling axis can have its plate secured to the side of the box which is parallel to and spaced from the surface of plate 1. A strong thin-walled metal four-sided shell can be positioned over each front wheel position and provided with flanges for securing it to and complementing portions of a rail 6 and plate 1 to form a generally cubical box to enclose and support a swiveled wheel at each of these front wheel locations. As an alternative, a conventional easily detachable swiveled wheel having a stem for swiveling support can be provided with a stem socket similarly secured to that box side which is spaced from and parallel to the plate 1. For swiveled wheels the apertures in the plate 1 are enlarged and made annular to accommodate swiveling movement. The height of the rolling surfaces of such swiveled wheels would similarly project only a slight distance outwardly from the smooth sliding surface of the top plate 1.
Other variations within the scope of this invention will be apparent from the described embodiment and it is intended that the present descriptions be illustrative of the inventive features encompassed by the appended claims. | A combined collapsible beach table, dolly and sled structure having a flat smooth table-top surface slidable over a sandy beach when the table is inverted and having recessed wheels with rolling surfaces projecting only slightly from the sliding surface to rollably support the inverted structure on a hard smooth surface. A pair of folding dual-leg members are extended to support the structure as a table and to retain loads thereon when the structure is inverted and used as a sled or dolly. The dual-leg members are folded against the table top to form a compact storable structure. A detachable pulling handle is storable in the compact folded structure. | 1 |
This Appln claims the benefit of Provisional No. 60/093,959 filed Jul. 24, 1998.
BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates generally to downhole tools and methods for completing a well and, more particularly, to a downhole tool and method for placing a gravel pack in a well.
2. Background Art
In the petroleum industry, completion of a well drilled through subterranean formations generally involves lining the well with a casing and using a perforating gun to create perforation tunnels through the casing and the formation adjacent the casing. The perforation tunnels are usually created adjacent the formation at pay zones to allow reservoir fluids to flow from the formation into the well. During production of the reservoir fluids, sand may flow from the formation into the well if the formation is composed of unconsolidated sand. Typically, production of sand along with reservoir fluids is undesirable for many reasons, some of which include clogging of surface equipment, erosion of the tubing strings and wellhead, and bridging of the well such that further production of reservoir fluids is prevented.
However, production of sand along with reservoir sands is not a new problem in the petroleum industry, and there has been a lot of research and development in the area of sand control during reservoir fluid production. One sand control technique that has been found to be successful and reliable is gravel pack completion. Gravel pack completion involves placing a screen in the well adjacent the perforation tunnels and filling an annular area between the casing and the screen, as well as the perforation tunnels, with well-sorted, coarse sand, called gravel pack. The gravel pack is highly porous and permeable and serves to filter formation sand from the reservoir fluids entering the well. The filtering performance of the gravel pack depends on the size and shape of the gravel pack sand and how well the gravel pack fills the annular area between the casing and the screen. If there are voids in the gravel pack, the formation sand can fill the voids and reduce the rate at which the reservoir fluids are produced, or the produced sand can erode the screen and cause the gravel pack to fail.
One method for efficiently placing gravel pack in the well and the perforation tunnels is circulating gravel packing. A gravel pack tool is lowered into the well on the end of a tubing string and gravel suspended in a carrier fluid is pumped down the bore of the tubing string and through a crossover tool into the annular area between the screen and the casing. The gravel is held in place by the screen while the carrier fluid flows through the screen and crossover tool into the casing annulus and back to the surface. Generally, the gravel pack tool is substantially larger than the tubing string and would typically require that any existing tubing string and other restrictions in the well be removed before the gravel pack tool is run into the well. However, retrieval of existing tubing in a well is a relatively expensive operation and may not be economically viable for marginally producing or nearly depleted wells.
Another method for placing gravel pack in the well and the perforation tunnel involves pumping a gravel slurry in a viscous carrier fluid through a tubing string. The carrier fluid is squeezed into the formation and placed across the perforated interval. Again, while the tubing string may be lowered through an existing tubing in the well, the cost of deploying the tubing string may be fairly expensive for marginally producing wells. Thus, it would be beneficial to have a tool that can efficiently place a gravel pack in a well and that can be lowered into the well through a tubing and other restrictions in the well. U.S. Pat. Nos. 5,033,549 and 5,115,860 to Champeaux et al. disclose a gravel pack tool that can be lowered through a tubing on the end of an electric wireline. The gravel pack tool features radially extending members that collapse while the gravel pack tool is lowered through the tubing and extends when the gravel pack is placed below the tubing. Gravel is disposed in the well annulus using a dump bailer.
SUMMARY OF THE INVENTION
One aspect of the invention is an apparatus for use in gravel packing a well which comprises a tool body adapted to be lowered into the well and a screen coupled to the tool body. A resilient member is coupled to the screen to vibrate the screen in response to an excitation force.
Another aspect of the invention is a method for gravel packing a well which comprises placing a screen at a selected position in the well, disposing sand control media in an annulus between the screen and the well, and periodically vibrating the screen to allow for even filling of the annulus.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a downhole tool suspended in a well.
FIG. 2A is a cross-sectional view of the oscillating assembly referenced in FIG. 1 .
FIG. 2B is a cross-sectional view of the lower anchor shown in FIG. 2A in a deployed position.
FIG. 3A is a cross-sectional view of the latching head assembly shown in FIG. 1 in a running-in position.
FIG. 3B is a cross-sectional view of the latching head assembly shown in FIG. 3A in a deployed position.
FIG. 3C is a cross-sectional view of the latching head assembly attached to the vent pipe shown in FIG. 1 .
FIG. 4A shows a dump bailer attached to the latching head assembly shown in FIG. 3 A.
FIG. 4B shows the dump bailer actuator shown in FIG. 4A released from the latching head assembly.
DETAILED DESCRIPTION
Referring to the drawings wherein like characters are used for like parts throughout the several views, FIG. 1 shows a downhole tool 100 suspended in a well 102 . A casing 104 extends along the length of the well 102 . The downhole tool 100 is concentrically received in the well 102 such that an annular area 106 is defined between the casing 104 and the tool 100 . The casing 104 includes perforations 108 which permit formation fluids from the formation adjacent the casing 104 to flow into the well 102 . The portion of the annular area 106 adjacent the perforations 108 is isolated at the bottom by a plug 110 and cement section 112 . The annular area above the cement section 112 is filled with a gravel pack 114 . The gravel pack 114 may be composed of any uniform, graded, commercial silica sand. The gravel pack 114 may also be composed of appropriately sized spherical ceramic beads. A cement cap 116 above the gravel pack 114 prevents the gravel pack 114 from loosening.
The tool 100 includes a flow segment 118 , a screen 120 , and an oscillating assembly 200 . The flow segment 118 includes a section of blank pipe 122 , a vent pipe 124 , and a latching head assembly 300 . The latching head assembly 300 includes an upper centralizer 302 which centers the tool 100 within the well and helps locate the top of the tool. The latching head assembly 300 also includes a latching head 304 which allows for easy retrieval of the tool and for latching onto the tool to operate the oscillating assembly 200 . The oscillating assembly 200 may be operated to oscillate the screen 120 to allow for efficient packing of gravel in the annular area between the casing and the screen. The lower end of the blank pipe 122 includes a threaded collar which mates with a similarly threaded collar on the upper end of the screen 120 . The blank pipe 122 provides a reservoir for extra gravel above the screen 120 .
Formation fluid flowing through the gravel pack 114 enters the screen 120 and flows upward into the vent pipe 124 , where it exits into the annular area above the cement cap 116 . The fluid in the annular area above the cement cap 116 may be returned to the surface through a tubing string (not shown). The screen 120 may be a wire-wrapped screen or other type of screen. There are many types of wire-wrapped screens, including ribbed, all-welded, groove, and wrapped-on-pipe. Typically, the all-welded screen is stronger and more corrosion-resistant and will not unravel if the wire is eroded or broken. The diameter of the screen 120 should be as large as possible and yet leave room for a gravel pack and be able to enter restricted diameter areas, such as tubing and valves, in the well. The screen size should be such that any formation sand entrained in the formation fluid does not get into the screen. The gravel size should be selected to restrict the movement of fine formation sand and, at the same time, allow production of formation fluids at economical rates.
Referring to FIGS. 2A and 2B, the oscillating assembly 200 includes an oscillating housing 202 and a mandrel 204 . The mandrel 204 is secured to an anchor assembly 206 that is adapted to engage the casing 104 upon landing on the cement section 112 (shown in FIG. 1 ). The anchor assembly 206 includes a fishing neck 208 that is secured to the lower end of the mandrel 204 by a shear pin 205 . A rod 210 extends from the fishing neck 208 through an anchor 212 . The anchor 212 is supported on an upper annular body 214 . Extending through the annular body 214 is an annular piston 216 . The upper end of the annular piston 216 is attached to the rod 210 . A mandrel 218 disposed within the annular piston 216 has one end attached to a bull nose 220 . The bull nose 220 is secured to the annular piston 216 by a shear pin 222 .
The bull nose 220 extends through a lower annular body 224 . An annular plate 226 is disposed about the annular piston 216 . The annular plate 226 is slidable along the length of the annular piston 216 . The annular plate 226 is coupled to the lower annular body 222 by a spring 228 . In the compressed state of the spring, collapsible collets 230 on the annular piston 216 restrict upward movement of the annular plate 226 . When the tool 100 lands on the cement section 112 with sufficient force to shear the shear pin 222 , the bull nose 220 retracts into the lower annular body 222 and pushes the mandrel 218 and rod 210 upwardly. This movement creates a gap between the annular plate 226 and the collets 230 , allowing the spring 228 to be released. The force of the spring 228 pushes the annular plate 226 over the collets and against the upper annular body 214 to deploy the anchor 212 .
The oscillating housing 202 includes a chamber 232 which houses a resilient member, for example, spring 234 . At the lower end of the spring 234 is a plate 236 which is attached to the mandrel 204 . The oscillating housing 202 may be moved up and down the mandrel 204 by compressing and extending the spring 234 . The axial axis of the mandrel 204 is generally aligned with the axial axis of the well 102 (shown in FIG. 1) so that the oscillating housing 202 moves along the axial axis of the well 102 . As the oscillating housing 202 moves, the screen 120 mounted on top of the oscillating housing 202 also moves. This allows for even filling of the annular area between the casing 104 and the screen 120 during gravel packing. A key 238 and slot 240 is provided on the mandrel 204 to allow the oscillating housing 202 and other components above the oscillating housing 202 to turn as the oscillating housing 202 moves relative to the mandrel 204 . The shear pin 205 holding the mandrel 204 to the fishing neck 208 is not sheared when the oscillating housing 202 moves relative to the mandrel 204 or when the anchor 212 is deployed. However, the shear pin 205 may be sheared at a later time to permit the tool 100 to be retrieved from the well.
Referring to FIGS. 3A and 3B, the latching head assembly 300 includes a body 306 . The latching head 304 , previously illustrated in FIG. 1, is attached to the body 306 . The upper end of the body 306 includes a threaded collar 308 which allows another threaded tool section to be attached to the body 306 . The upper centralizer 302 has one end connected to the threaded collar 308 and a second end connected to a washer 310 that is disposed about the body 306 . A spring 312 has one end connected to the washer 310 and another end connected to the lower end 314 of the body 306 . The spring 312 is held in a compressed state by locking pins 316 . The locking pins 316 are located in grooves in the body 306 . Extending through the center of the body 306 is a deployment rod 318 . The deployment rod 318 is movable within the body 306 by a releasing tool (not shown).
When the deployment rod 318 is used to run the tool 100 into the well, the locking pins 316 have one end abutting against the washer 310 and another end abutting against the deployment rod 318 . The locking pins 316 move inwardly into the body 306 to allow the spring 312 to extend when the deployment rod 318 is released from the body 306 . As the spring 312 extends, the upper centralizer 302 extends and centers the tool 100 within the well. The anchor of the upper centralizer 302 is such that when the tool 100 is retrieved, the upper centralizer 302 collapses back to allow the tool to be pulled through restricted diameter area.
Referring to FIG. 3C, the latching head assembly 300 includes a mechanical jar 320 which is fixed to the lower end 314 of the body 306 . The mechanical jar 320 extends into the vent pipe 124 and is held in place in the vent pipe 124 by a shear pin 322 . The shear pin 322 is sheared when the tool is dropped on the cement section 112 . When the shear pin 322 is sheared, the lower end 314 of the body 306 sits on a shoulder 324 at the upper end of the vent pipe 124 . The mechanical jar 320 is like a hammer and may be stroked to vibrate the spring 234 in the oscillating housing 202 such that the oscillating housing 202 moves up and down the mandrel 204 . As the oscillating housing 202 moves up and down, the screen 120 also moves up and down. The mechanical jar 320 may be stroked by latching onto the latching head 304 , raising the latching assembly 300 to a sufficient height, and then subsequently dropping the latching assembly 300 . When the latching assembly 300 is dropped, the mechanical jar 320 provides the energy required to vibrate the spring 234 . At the end of the mechanical jar 320 is a retaining nut 326 which ensures that the latching head assembly remains coupled to the vent pipe 124 .
Referring to FIGS. 4A and 4B, a release tool, for example, a dump bailer actuator 400 , is shown attached to the latching head assembly 300 . The dump bailer actuator 400 includes an extension sleeve 402 which is mounted on a tapered skirt 404 and a grapple 406 that latches onto the latching head 304 . At the upper end of the grapple 406 is a plate 408 . A deployment rod 410 extends from the plate 408 into the latching head assembly 300 . The deployment rod 410 and lock pins 316 prevent the spring 312 from extending to open the upper centralizer 302 before the dump bailer actuator 400 releases the latching head assembly 300 . A weight bar extension 412 is mounted on the plate 408 . The bar extension 412 is connected to a body 414 by a collet 416 . A spring 418 extends between the body 414 and the plate 408 . The spring 418 is in a compressed state until the dump bailer actuator 400 is actuated to release the latching head assembly 300 .
The dump bailer actuator 400 is operated by moving the extension sleeve 402 and the tapered skirt 404 upwardly such that the grapple 406 slides into the tapered skirt 404 . When the grapple 406 slides into the tapered skirt, the spring 418 is extended and the bar extension 412 is separated from the body 414 . The grapple 406 releases the latching head 304 when it engages the tapered skirt 404 , thus allowing the dump bailer actuator 400 to be separated from the latching head assembly 300 . As the dump bailer actuator 400 is pulled from the latching head assembly, the deployment rod 410 is pulled out of the latching head assembly 300 and the locking pins 316 move inwardly to allow the spring 312 to open the centralizer 302 .
In operation, when it is desired to gravel pack a new zone, the plug 110 and the cement 112 are set below the new zone. Then a perforating gun is lowered to the new zone to make perforations in the casing 104 and the formation adjacent the casing. When the perforations are made, a release tool, for example, the dump bailer actuator 400 , is attached to the tool 100 and the release tool and the tool 100 are lowered to the new zone on the end of a wireline, a slickline or other suitable conveyance device. The release tool is then operated to release the tool 100 such that the tool 100 lands on the cement 112 with sufficient force to release the anchor 212 . The released anchor 212 tightly engages the casing 104 and holds the tool 100 in place in the well. The upper centralizer 302 opens when the release tool is detached from the tool 100 and centers the tool 100 within the well. At the same time that the tool 100 is anchored and the upper centralizer 302 is opened, the mechanical jar 320 is sheared from the vent pipe 124 . This makes it possible to latch on the latching head assembly 300 and stroke the mechanical jar 320 . The latching head assembly 300 can also be used to retrieve the tool 100 .
Gravel may be dumped between casing 104 and the screen 120 by a dump bailer. The dump bailer may be a bailer with a frangible bottom that can be opened with an explosive charge. The dump bailer may also be a bailer that can be latched onto the latching head assembly 300 and that has a dump port that can be mechanically opened to dump gravel into the well. The dump bailer is small enough that it can fit through restricted diameters, such as a tubing string, in the well. When the gravel is dumped, the oscillating assembly 200 can be operated to oscillate the screen 120 to ensure that voids in the gravel pack are filled with gravel. More gravel can be dumped into the well until the gravel pack level rises above the upper end of the screen 120 . Then the cement cap 116 can be put in place to keep the gravel from loosening.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous variations therefrom without departing from the spirit and scope of the invention. For example, the latching head assembly 300 is shown as having one latching head 304 , but additional fishing necks can be added to the latching head to allow different types of tools to be latched onto the latching head assembly 300 . The latching head and fishing neck may be provided with magnetic markers which will allow a magnetic sensor, for example, a collar locator, to locate them downhole. Additional centralizers may be added to the tool 100 below the flow segment 118 to further centralize the tool 100 within the well. | An apparatus for use in gravel packing a well includes a tool body adapted to be lowered into the well, a screen coupled to the tool body, and a resilient member coupled to the screen. The apparatus is placed at a selected position in the well, and sand control media is disposed between the screen and the well while the resilient member is periodically excited to vibrate the screen. | 4 |
BACKGROUND OF THE INVENTION
The dissociation of oxygen from the hemoglobin molecule, an intregal part of the transport of oxygen, can be described by the oxyhemoglobin dissociation curve. This assessment of the respiratory function of the blood takes on clinical significance in the characterization of congenital hemoglobinopathies, in evaluation of blood oxygen transport capability during respiratory and metabolic acid-base disturbances, and more recently in the evaluation of certain forms of ischemic heart disease. The oxyhemoglobin dissociation curve, together with its characteristic parameter P 50 , the partial pressure of oxygen at half-saturation of hemoglobin with oxygen, is known to be affected by changes in temperature, the partial pressure of carbon dioxide, pH, blood organic phosphate concentration and hemoconcentration. Furthermore, the dissociation of oxygen from hemoglobin or whole blood can best be described by a method which measures or controls the majority of these variables, while recording the dissociation process. Presently, there are many methods available for oxygen dissociation curve analysis as, for example, those described by J. D. Torrance and C. Lenfant, in an article entitled "Methods For Determination of O 2 Dissociation Curves, Including Bohr Effect", Respiratory Physiology, Volume 8, pages 127-136 (1970). The most acceptable of these are methods which record the oxyhemoglobin dissociation reaction as a continuous function of blood oxygen tension, and which continuously record pH change in order to assess the Bohr effect on the hemoglobin-oxygen reaction.
The Laver method, described in an article by M. A. Duvelleroy, R. G. Buckles, S. Rosenkaimer, C. Tung and M. B. Laver, entitled "An Oxyhemoglobin Dissociation Analyzer", published in the Journal of Applied Physiology, Volume 28, pages 227-233 (1970), characterizes the oxyhemoglobin dissociation process in this manner. However, this method falls short of perfect assessment of this equilibrium reaction, because it fails to account for changes in the intracellular hydrogen ion concentration or the transcellular hydrogen ion gradient caused by fluctuations in the concentration of the impermeable intracellular anion 2,3-diphosphoglycerate (2,3-DPG). At present there exists no satisfactory prediction formula for the correction of P 50 due to changes in 2,3-DPG concentration. Nevertheless, 2,3-DPG concentration can be measured separately and the P 50 can be interpreted in light of its 2,3-DPG magnitude. Finally, the clinical usefulness of even the Laver apparatus is limited, however, by such factors as cost of apparatus, occasional instability of the gas phase P 02 electrode, time of procedure, method for calculation of P 50 , and sample size. The latter of these is a critical limitation in that newborns and young infants do not have a blood volume large enough to justify such a blood sample (approximately 8.0 ml).
SUMMARY OF THE INVENTION
It is an object of this invention to provide an apparatus for the determination of the dissociation characteristics of oxygen from blood which is simple in construction, inexpensive of manufacture and extremely reliable in use.
It is another object of this invention to provide a simple method for determining the dissociation characteristics of oxygen from blood.
It is another object of this invention to provide method and apparatus for the determination of the dissociation characteristics of oxygen from blood which produce the desired results more quickly than heretofore known.
Another object of this invention is to provide method and apparatus for the determination of the dissociation characteristics of oxygen from blood which produce the desired results with smaller blood samples than heretofore required.
It is an even still further object of this invention to provide method and apparatus for the determination of the dissociation characteristics of oxygen from blood which are more reliable than prior art methods and apparatus.
These, and other, objects are obtained according to the instant invention by providing method and apparatus for the determination of the dissociation characteristics of oxygen from blood. The functional relationship between increasing liquid phase P 02 and decreasing pH is determined and presented in the form of a continuous curve for values ranging from desaturation to saturation. By analyzing this data through linear regression techniques, the characteristic parameter of the oxygen dissociation curve, P 50 , may be easily determined.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention as well as other objects and further features thereof, reference is made to the following detailed disclosure of the invention taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a schematic representation of the apparatus of the instant invention.
FIG. 2 is a graph showing the curve generated by employment of the method and apparatus of the instant invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The descriptive parameter of the oxyhemoglobin dissociation curve, P 50 , may be defined as the liquid phase oxygen tension, i.e., whole blood or hemoglobin solution, at which the hemoglobin is half saturated with oxygen. The instant invention relies upon the fact that P 50 may be determined as the mid-point of the pH vs. P 02 (liquid) curve, which is characteristic of the dissociation reaction.
Referring now to FIG. 1, there is shown the general apparatus arrangement, 10, according to the instant invetion. A reaction block 11 comprises a bottom section 12 and a top section 13, lapped together for a sealing relationship and mounted on a common central axis 15. The two sections 12 and 13 are shown separated in the drawing; however, during use they are in intimate contact with each other as shown by the dotted lines. The top section 13 can be rotated 180° relative to the bottom section 12 for reasons to be explained below.
Each of sections 12 and 13 contain two half chambers 14, 16, 17 and 18 arranged symmetrically about central axis 15, and by making the 180° rotation of section 13 the cooperative relationship between the half chambers may be changed. More specifically, initially the half chambers 14 and 17 make up a complete chamber 14-17 and half chambers 16 and 18 make up a complete chamber 16-18; however, rotation of section 13 makes new complete chambers 14-18 and 16-17.
Half chamber 14 contains an outlet passage 19 through which gases may pass to either a reservoir or the atmosphere. Half chamber 16 is in communication with the ends of three instrument holders 21, 22 and 23, the function of which will be further described below. A source of oxygen gas (97% oxygen--3% CO 2 ), not shown, is in fluid communication with half chamber 17 via tube 24. Half chamber 18 is in communication with a source of nitrogen gas, also not shown, via tube 26. Finally, half chamber 18 is further in communication with sample inlet control device 27.
Instrument holders 21, 22 and 23 are designed to sealingly accept, respectively, a liquid phase P 02 electrode 31, a calomel electrode 32 and a pH electrode 33. The P 02 electrode measures the partial pressure of oxygen of the liquid sample to be placed within the chamber. Calomel electrode 32 provides a reference measurement relative to the sample pH to insure accurate pH measurement by the electrode 33. Each of the electrodes is in communication with the interior of half chamber 16 so that intimate contact may be made with the sample placed therein.
P 02 electrode 31 is electrically connected via line 37 to meter 36 which provides a visual indication of the variation of the partial pressure of oxygen within the sample. Similarly, electrodes 32 and 33 are connected, respectively, via lines 34 and 38 to meter 39 which shows the continuous changes in pH.
The signals generated by meters 36 and 39 are fed, via lines 41 and 42, to an interface unit 43. The interface unit merely modifies the incoming electrical signals to a voltage and pattern suitable for input to X-Y recorder 47. The modified signals are transferred from unit 43 to recorder 47 through lines 44 and 46.
Recorder 47 includes an arm 48 which traverses paper 49 in a left-to-right direction. Simultaneously with the movement of arm 48, slidable pen 51 moves vertically on the arm. The signal from pH meter 39 controls movement of pen 51 in the Y-direction, and the signal from P 02 meter 36 controls the X-movement of arm 48. The resulting printed curve 52, as will be described further below, represents the relationship between changing pH and liquid phase partial pressure of oxygen.
In operation, the reaction block 11 is positioned to define complete chambers 14-17 and 16-18. Oxygen is flushed through chamber 14-17 via tube 24 and outlet tube 19 to provide an oxygen atmosphere therein. Chamber 16-18 is then, or simultaneously with the oxygen flush of chamber 14-17, flushed with a nitrogen gas through inlet 26 and out through sample control device 27 to provide a 100% nitrogen atmosphere therein. A blood sample of from about 1/2 ml to about 4 ml. is then inserted into the chamber 16-18 by inserting a syringe through sample control device 27 and forcing the blood into the chamber. The sample has been "tonometered", to a partial pressure of oxygen equal to zero, i.e., the oxygen has been driven out in a nitrogen flush. The oxygen may be taken from the blood either before insertion into the chamber 16-18 or thereafter by continuing the nitrogen flow through tube 26 and control device 27. The process may be aided by inclusion of a magnetic stirring rod within the half chamber 16 to continuously agitate the sample. Thus, the initial conditions of chamber 14-17 having an oxygen rich atmosphere and the sample having a partial pressure of oxygen equal to zero have been created.
Section 13 of reaction block 11 is then rotated through 180°to reposition half chambers 17 and 18 above, respectively, half chambers 16 and 14. Chamber 16-17 thus contains a sample having a partial pressure of oxygen equal to zero below an oxygen rich atmosphere. Chamber 14-18 is no longer of any consideration and the contents thereof may be flushed to a waste reservoir.
As the oxygen in half chamber 17 is absorbed by the blood sample in half chamber 16 over a period of time, electrodes 31, 32 and 33 measure the changes therein. The changes are read visually on meters 36 and 39 and are printed out on the X-Y recorder 47. As the oxygen is being absorbed by the blood sample pressure variations may occur in half chamber 17, so, to alleviate this a nitrogen bleed 25 is used to admit small amounts of gas from a source, not shown.
Referring now to FIG. 2, the curve printed on X-Y recorder 47 can be seen. The changes in partial pressure of oxygen in the liquid sample are in the X-direction and the changes in pH are shown in the Y-direction ranging from 6.8 to 7.8. The curve 52 starts at point A, which represents zero saturation and levels off at point B which represents 100% saturation. Half way between points A and B a line C is extended horizontally to intersect curve 52 to determine P 50 at point D. Point D thus represents the partial pressure of oxygen at 50% saturation.
One of ordinary skill in the art will readily recognize and understand the various elements which together comprise the novel apparatus and method of the instant invention. All of the structural components mentioned above except the X-Y recorder are available from RADIOMETER of Copenhagen, Denmark, and distributed in the United States by the London Company, 811 Sharon Drive, Cleveland, Ohio. For example, the RADIOMETER parts numbers correspond with the elements as follows:
pH meters -- PHM 71
interface -- L101
P 02 electrode -- E5043-0
pH electrode -- G267C
calomel electrode -- K4018
A suitable reaction block and associated hardware is also sold by RADIOMETER under the designation DCA-1. It should be noted at this time that the reaction block 11 preferably includes other hardware, not shown, such as thermostatic controls and gas humidifiers. These elements are not shown or described in detail because they are well known in the art and contribute only insignificantly to the instant invention.
Any suitable X-Y recorder may be used to graph the output of the instrumentation. Obviously, even an X-Y-Y recorder such as a Honeywell model 540 may be used, without employing the second Y-axis printer.
It will be understood various changes in the details, materials, steps and arrangements of parts, which have herein been described and illustrated in order to explain the nature of the invention, will occur to and may be made by those skilled in the art upon a reading of the disclosure within the principles and scope of the invention.
For example, it is contemplated an important advantage may be attained by making half chambers 14, 16, 17 and 18 quite small and accordingly modifying the location of the insertion points of electrodes 31, 32 and 33. It is possible, with such structure, to employ samples as small as 1/2 ml. and still obtain accurate results. | Method and apparatus are disclosed for the determination of the dissociation characteristics of oxygen from blood. The functional relationship between increasing liquid phase P 02 and decreasing pH is determined and presented in the form of a continuous curve for values ranging from desaturation to saturation. By analyzing this data through linear regression techniques, the characteristic parameter of the oxygen dissociation curve P 50 , may be easily determined. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to a process for the preparation of [S(−) amlodipine-L(+)-hemi taratarte] from RS amlodipine base using L(+) tartaric acid in the presence of dimethyl sulfoxide.
BACKGROUND OF THE INVENTION
[0002] Amlodipine and its salts are long acting calcium channel blockers and are useful for the treatment of cardiovascular disorders. Racemic Amlodipine is currently being used as its besylate in the treatment of hypertension and angina. The preparation of racemic compound is described in European patent 0089167. Amlodipine is racemic compound and has chiral center at 4 position of the dihydropyridine ring.
[0003] It has also been reported that the R(+) isomer is a potent inhibitor of smooth muscle cell migration (PCT/EP-94/02697). The S(−) isomer is having calcium channel blocker activity while the R(+) isomers has little or no calcium channel blocking activity.
[0004] Prior art for the preparation of R and S enantiomers of amlodipine are a) resolution of amlodipine azide ester with optically active 2-methoxy-2-phenylethanol (J. Med. Chem., 29, 1696, 1986. J. E. Arrowsmith, S. F. Campbell, P. E. Cross, J. K Stabs, R. A., Burges and EP Appl. 0331315A) or b) resolution of Amlodipine base with optically active camphanic acid [J. Med. Chem., 35, 3341, 1992, S. Goldman, J. Stoltefuss and L. Born) or c) resolution of RS.-amlodipine base to R(+) and S(−) isomer with L or D tartaric acid respectively in organic solvent DMSO {Peter L., Spargo U.S. Pat. No. 6,046,338; (2000), PCT 95/25722 (1995)] which indicate the use of both tartaric acids is essential.
[0000] The Disadvantages:
[0000] The main disadvantages of the prior art are:
[0000]
1. The use of unnatural tartaric acid for the separation of S(−) amlodipine
2. The use of costlier camphanic acid or 2-methoxy-2-phenylethanol as a resolving agents.
OBJECTS OF THE INVENTION
[0007] The main object of the invention is to develop a technology for the preparation of S(−) amlodipine from racemic amlodipine using naturally occurring L-tataric acid.
SUMMARY OF THE INVENTION
[0008] Accordingly, the invention provides a new and efficient process for the preparation of [S(−) amlodipine-L(+)hemi tartarte] in good yield with high enantiomeric purity by reacting RS amlodipine base with L(+) tartaric acid in an organic solvent at a temperature ranging from 20-35° C. for a period ranging from 16 to 24 hours, separating by filtration solid [R(+) amlodipine-L(+)-hemi taratarte], seeding the filtrate to obtain solid [S(−) amlodipin-L(+)-hemi taratarte], filtering and recrystallising the solid, basifying to obtain S(−) amlodipine.
[0009] In one embodiment of the present invention the organic solvent used for the reaction is dimethyl sulfoxide.
[0010] In another embodiment of the present invention 0.5 mole of L(+) tartaric acid is used for the reaction.
[0011] In another embodiment the solvent used for crystallization is selected from the group consisting of methanol, ethanol and butanol.
[0012] In another embodiment of the invention basification is done using metal hydroxides, carbonates or aq. Ammonia
DETAILED DESCRIPTION OF THE INVENTION
[0013] The unique feature of the invention is preferential crystallization of enantiomer salt with respect to quantity of DMSO and time. The process of resolution of RS amlodipine using L(+) tartaric acid is shown in the scheme below:
[0014] The process of the present invention is described herein below with reference to examples which are illustrative only and should not be construed to limit the scope of the present invention in any manner.
EXAMPLE-1
[0015] Amlodipine hemi L tartarate-mono-DMSO solvate mp 160-162° C. [α] t =+24.32 (c=1, R(+) Amlodipine-hemi-L-tartarate mono DMSO solvate and S(−) Amlodipine-hemi-L tartarate mono DMSO solvate from (RS) Amlodipine.
[0016] To a stirred solution of 10.50 gm (0.0256 mole), of RS Amlodipine in 30 ml of DMSO was added a solution of 1.93 (0.128) mole (0.5 equiv) of L(+) Tartaric acid in 30 ml DMSO. The solid starts separating from clear solution within 5-10 min. This was stirred for 3 hrs. and the solid was filtered off, washed with acetone and dried to give 6.66 gm, 46.15% R(+) MeOH). The filtrate was seeded with S(−) amlodipine hemi L(+) tartarate salt. and left overnight the solid was filtered off and washed with 10 ml acetone and dried to give 6.41 gm, 44.4% S(−) amlodipine-hemi L(+)-tartarate mono DMSO solvate. mp 169.5-171.5° C.=−14.1 (c=1, MeOH) 90% de by chiral HPLC. (J. Chrom., B 693, 367 (1997) J. Luksa, Dj. Josic, B. Podobinc, B. Furlan, M. Kremser]
EXAMPLE-2
[0017] RS Amlodipine L(+) tartarate mono DMSO solvate from RS Amlodipine
[0018] The procedure as described in example 1 was repeated and the reaction was kept overnight. The solid filtered and dried to yeidl 14 gm, 97.9% RS Amlodipine L(+) tartarate mono DMSO solvate. Mp 148.5-151° C. (c=1 MeOH) 3.3% de by chiral HPLC.
EXAMPLE-3
[0019] S(−) Amlodipine hemi L(+) tartarate monohydrate from S(−) Amlodipine-hemi-L (+) tartarate monohydrate DMSO solvate-methanol as solvent.
[0020] 50 gms of S(−) Amlodipine-hemi-L(+)-tartarate mohohydrate DMSO solvate was dissolved in 250 ml refluxing methanol (30 min). The solution was kept overnight at room temperature (25-28° C.) with stirring. The solid was collected by filtration, washed with 100 ml methanol and dried at 50° C. in vacuo (2 hrs till constant wt.) to give 35 gm (80%). S(−) Amlodipine-hemi-L(+)-tartarate monohydrate. Mp 171-172° C.=114.1 (c=1, MeOH); 90% de chiral HPLC.
EXAMPLE-4
[0021] S(−) Amlodipine hemi L(+)-tartarte mohohydrate from S(−) Amlodipine-hemi-L-(+) tartarate monohydrate DMSO solvate—Ethanol as solvent.
[0022] The procedure was followed as mentioned in example 3 was using ethanol (150 ml) instead of methanol. The solid obtained was collected by filtration, washed with 50 ml cold ethanol and dried at 50° C. in vacuo (2 hrs till constant wt.) to give 30 gms (68%). S(−) Amlodipine hemi L(+) tartarate monohydrate mp 172.5-174° C.=17.44 (C=1, MeOH), 97% de chiral HPLC.
EXAMPLE-5
[0023] S(−) Amlodipine from (S) (−) amlodipine hemi L (+) tartarte mobonydrate.
[0024] S(−) Amlodipine hemi L(+) tartarate mohohydrate (30 gms) was slurried in 60 ml CH 2 Cl 2 and 60 ml (6%) aqueous ammonia for 30 mm. The organic solution was separated and washed with water. The organic extract was dried to give solid. The solid was filtered and dried at room temperature under vacuo to give 20 gms (82%) S(−) amlodipine mp 108-109° C. 30.55 (c=1, MeOH), 97.4% ee by chiral HPLC.
EXAMPLE-6
[0025] S(−) Amlodipine from S(−) amlodipine hemi L(+) tartarte mono DMSO solvate
[0026] S(−) Amlodipine hemi L(+)-tartarate mono DMSO solvate (30 gms) was slurried in 60 ml CH 2 Cl 2 and 60 ml (6%) aqueous ammonia for 30 min. The organic solution was separated and washed with water. The organic extract was dried over anhydrous sodium sulphate and concentrated. The residue was triturated with hexane to give solid 20.1 gms (92%) S(−) amlodipine. Mp 107-107.5° C. 27.3 (c=1, MeOH), 90% ee by chiral HPLC. | The present invention relates to a process for the preparation of [S(−) amlodipine-L(+)-hemi taratarte] from RS amlodipine base using L(+) tartaric acid in the presence of dimethyl sulfoxide. | 2 |
This is a continuation of application Ser. No. 07/966,232, filed Oct. 26, 1992, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a method for imparting color to a contact lens. More specifically, it relates to an improved method for uniformly dispersing a dye throughout a soft, hydrogel contact lens.
The conventional method for imparting an evenly dispersed tint in a soft contact lens is described, for example, in U.S. Pat. No. 4,468,229. Generally, the lens is first soaked in an aqueous solution of the dye, and then the dye is bonded to the lens in a separate solution. The lens is typically composed of a hydrophilic polymer derived from the polymerization of hydrophilic monomers. The bonding of the dye to the lens is carried out by contacting the soaked lens with an aqueous base prior to the final hydration step, which is intended to provide the soft, hydrogel lens with the desired amount of water at an acceptable pH.
The dyes which are used in the conventional method are typically derived from a halotriazine such as a dihalotriazine or monohalotriazine, especially water-soluble dichlorotriazines. Dichlorotriazine or monohalotriazine dyes that carry sulfonate functionalities, for example, are soluble in water, so it is necessary that bonding occur with the hydrophilic polymer from which the lens is composed before the final hydration step. Otherwise, the dye could migrate within the lens to create an uneven dispersion, or leach out from the lens into the eye of the wearer.
The dye which imparts the tint to a soft lens made using the conventional method not only is dispersed in the lens, but also does not migrate within the lens or leach out of the lens after the bond has formed. The tinted lens is also stable in an aqueous medium and after repeated high temperature cycling, conditions which are present during routine wear and cleaning. The conventional method requires that the lens be soaked in a solution containing the dye which is at a specific concentration, and at a specific conductivity, so that the dye diffuses into the polymer. The conductivity is important since one may control the swelling of a lens by selecting various salt concentrations. It is also important that the dye concentration and time the lens stays in the dye soak be precisely controlled since the diffusion kinetics determine the intensity of the tinted contact lens. The conventional method employs a high concentration of dye in the dye wash so that the continuous tinting can be managed. Unfortunately, this method is cumbersome and requires multiple steps, especially at commercial scale production, because it is necessary to soak the lens in a solution of the dye at a specific concentration and time to create a dispersion of the dye in the lens. Therefore, because of this difficulty, alternative methods have been sought.
U.S. Pat. No. 4,157,892 discloses adding a functionality to the polymer from which the lens is derived which is reactive with the dye. The functionalized polymer is prepared by reacting a "coupler monomer" with a conventional hydrophilic monomer. This coupler monomer has a high probability of changing the physical properties of the polymer. The lens prepared from the functionalized polymer is immersed in a solution of a diazonium dye, where the dye then bonds to the polymer. Although adequate bonding occurs, this method still requires immersion of the finished lens in a solution of the dye.
Another interesting method for imparting color to a soft lens is disclosed in U.S. Pat. No. 4,640,805. This patent describes preparing a tinted lens using a conventional spin casting technique. A suspension of dye pigment in liquid monomer is applied to the mold surface prior to polymerization of bulk monomer in the spin cast mold. Although this method provides a simple way for imparting color to the surface of the lens, it does require that the mold be stamped or printed with specific geometries and spacing.
Attempts have been made to incorporate the dye in the lens by polymerizing the hydrophilic monomer from which the lens is derived in the presence of the dye. For example, U.S. Pat. No. 4,252,421 discloses polymerizing a hydrophilic monomer in the presence of a water-insoluble phthalocyanine dye. The dye is supposed to become entrapped in the finished, hydrated lens because of its incompatibility with water. Unfortunately, the dye will leach out of a lens derived from polymerizing the most commonly used hydrophilic monomer, hydroxyethylmethacrylate (HEMA), when the lens is fully hydrated to greater than about 40 weight percent water. This is even more of a problem with higher water content materials.
The '421 patent also discloses functionalizing the dye with a polymerizable vinyl group, and then subsequently bonding the functionalized dye during polymerization of the monomers from which the lens is derived. Although this eliminates the need for a post-bonding step, the water content of the lens is adversely affected unless hydrophilic --SO 3 H or --SO 3 Na groups are added to the phthalocyanine dye nucleus (as discussed at column 8 of the patent). This simply adds another burdensome step in the manufacturing process to make a contact lens suitable for extended wear applications.
In a similar manner, European Patent Application 0 396 376 discloses the use of a non-charged anthraquinone dye which is functionalized with a polymerizable group to facilitate bonding of the functionalized dye during polymerization of the hydrophilic monomer. Unfortunately, the non-charged dye leads to lower water solubility, if any at all, which in turn restricts the concentration of the dye which can be present in the lens. More importantly, however, the functionalized anthraquinone dye is by necessity a difunctional dye in this case. This difunctionality creates in effect a dye which is a crosslinker. As a result, the water content of the lens is further lowered, and lenses made with this difunctional dye are unacceptably brittle when the concentration of the dye in the lens is increased.
Finally, another attempt to impart color to a contact lens is disclosed in U.S. Pat. No. 4,639,105. This patent discloses spin casting a mixture of liquid monomer, soluble dye and pigment particles to prepare a lens with variations in color achieved by migration of the pigment particles during spin casting. Although this patent indicates that the dyes do not migrate, no reference is made of what specific dyes are used, and it is believed that such dyes will indeed migrate or leach during wear unless the dye used is functionalized with polymerizable groups as described above. Furthermore, such a lens is unsuitable for those applications where a uniform dispersion of dye or colorant is necessary or desired.
In view of the deficiencies of the prior art, a method of uniformly dispersing a water-soluble dye throughout a soft contact lens, without requiring the step of immersing the finished lens in a solution of the dye, is needed. Additionally, such a method would be extremely desirable if it could be used to prepare a tinted contact lens with physical and optical properties which substantially equal those of a conventional untinted lens. Specifically, a tinted contact lens with a water content and flexibility equivalent to those of a conventional untinted lens is needed.
SUMMARY OF THE INVENTION
The invention is an improved method for preparing a soft, hydrogel contact lens which has a dye dispersed substantially uniformly throughout the lens. The invention is an improvement of the conventional method of preparing such a lens, in which the lens is derived from the polymerization of a hydrophilic monomer and the lens is dyed with a coloringly effective amount of a water-soluble halotriazine dye. The improvement comprises reacting the dye with the hydrophilic monomer prior to polymerizing the monomer. The reaction occurs, under conditions effective to prepare a reactive dye which is predominantly a monofunctional dye. The hydrophilic monomer is then polymerized in the presence of a homogeneous solution of the reactive dye in the monomer.
The improved method of this invention eliminates the need to immerse the lens in an aqueous solution of the dye after polymerization of the hydrophilic monomer from which the finished lens is derived. Additionally, it is unnecessary to bond the dye to the lens after the lens is formed. This is so because the monofunctional dye reacts with, and bonds to, the polymer backbone of the lens. Therefore, it is unnecessary to wash the lens with large volumes of aqueous base to bond the dye to the lens.
The dye is uniformly dispersed throughout the lens, and it does not leach out of the lens into the eye of the wearer or migrate within the lens to create an uneven dispersion of the dye in the lens. In addition, the amount of dye necessary to achieve the desired degree of tinting of the lens is significantly less than the amount necessary when the finished lens is soaked in a solution of the dye according to conventional methods.
The intensity of the tint in the lens can be controlled accurately depending on the concentration of the monofunctional dye in the hydrophilic monomer. This contrasts with the conventional method, which requires precise control of not only the concentration of the dye in the aqueous soaking solution, but also the soaking time for the lens in the aqueous solution.
Furthermore, the physical and optical properties of the tinted lens are essentially equivalent to the physical and optical properties of a corresponding lens without the incorporation of the dye. For example, handling characteristics, wearer comfort, and lens clarity are not sacrificed when the dye is incorporated into the lens using the improved method of this invention. Most significantly, the water-soluble nature of the dye, and the fact that it does not act as a crosslinking agent because of its predominant monofunctionality, allows for the incorporation of increased amounts of the dye in the lens without sacrificing the water content and handling characteristics, e.g. flexibility, of the lens.
DETAILED DESCRIPTION OF THE INVENTION
The preferred class of halotriazine dyes are dihalotriazine dyes, especially dichlorotriazine dyes with at least one sulfonate functionality to render the dye water-soluble. Such dichlorotriazine dyes are described, for example, in U.S. Pat. Nos. 4,559,059 and 4,891,046, each of which is incorporated by reference herein. The most preferred dichlorotriazine dye is Color Index Reactive Blue 4. Monochlorotriazine dyes with at least one sulfonate functionality such as Reactive Blue #2 can also be incorporated into the lens material. The water soluble dyes which can be utilized in addition to Color Index Reactive Blue 4 include Procion Blue MRS; Fiber Reactive Brilliant Blue MRS; 2-anthracenesulfonic acid, 1-amino-4-(3-((4,6-dichloro-s-triazin-2-yl)amino)-4-sulfoanilino)-9,10-dihydro-9,10-dioxo, disodium salt; 2-anthracenesulfonic acid, 1-amino-4-(3-((4,6-dichloro-1,3,5-triazin-2-yl)amino)-4-sulfophenyl)amino)-9,10-dihydro-9,10-dioxo-, disodium salt; and 2-anthracenesulfonic acid, 1-amino-4-(3-((4,6-dichloro-s-triazin-2-yl)amino)-4-sulfoanilino)-9,10-dihydro-9,10-dioxo.
The conditions for reacting the water soluble halotriazine dye with the hydrophilic monomer in order to prepare a predominantly monofunctional dye will depend on the specific monomer chosen and the type of halotriazine dye used. These conditions can readily be determined empirically.
The reactive dye is "predominantly" monofunctional if as a result of the reaction not less than 50 percent of the active dye compounds formed have only one site of reactive functionality derived from the reaction of the dye with the hydrophilic monomer. If more than 50 percent of the active dye compounds were difunctional, then the dye would act as a crosslinker which may adversely affect the physical properties of the finished lens. Preferably, not less than 80 percent of the active dye compounds are monofunctional. Ideally, at least 95 percent of the dye is monofunctional.
The reaction of the dye with the monomer advantageously occurs in the presence of an organic Lewis base solvent which is capable of solubilizing the monomer and the dye. The reaction can be driven faster to completion if an equimolar or molar excess of the monomer is added to the reaction mixture. The reaction temperature is preferably raised above room temperature, e.g. 35-70° C., for about 16 to 32 hours. When the reaction is complete, the mixture is preferably neutralized to a pH of between 5-8. Any excess reactants, solvent and byproducts can be removed from the reactive dye compounds using conventional methods.
The Lewis base solvent acts as an inert diluent for the reaction between the monomer and the dye. Examples of suitable solvents include pyridine, tetrahydrofuran (THF), and dimethylsulfoxide (DMSO). However, the preferred solvent is an aqueous base, preferably an alkali or alkaline earth metal carbonate, or phosphate.
As used herein, a soft hydrogel contact lens refers to a gel-like lens derived from polymerizing a monomeric composition containing a hydrophilic monomer. A hydrophilic monomer refers to any monomer which, when polymerized, yields a hydrophilic polymer capable of forming a hydrogel when contacted with water. Examples of hydrophilic monomers include, but are not limited to, hydroxy esters of acrylic or methacrylic acid, N,N dimethylacryamide (DMA), N-vinyl pyrrolidone (NVP), and styrene sulfonic acid, and other hydrophilic monomers known in the art. The subsequently formed polymeric lens is swollen with a significant amount of water to form the hydrogel lens, typically greater than 30 percent and preferably at least 65 percent water.
The preferred hydrophilic monomer is a hydroxy ester of acrylic or methacrylic acid. Examples of hydroxy esters of acrylic and methacrylic acid include, but are not limited to, hydroxyethylmethacrylate (HEMA) hydroxyethylacrylate (HEA), glycerylmethacrylate, hydroxypropylmethacrylate, hydroxypropylacrylate and hydroxytrimethyleneacrylate. The most preferred hydroxy ester of acrylic or methacrylic acid is HEMA, which is the monomer most commonly used in the preparation of soft hydrogel contact lenses.
The hydrophilic monomer is preferably copolymerized with comonomers in a monomer reaction mixture to impart specific improvements in chemical and physical properties, depending on the particular application desired. For example, the equilibrium water content of the lens can be increased if methacrylic acid (MAA) is used as a comonomer. Additionally, polyfunctional crosslinking monomers, such as ethylene glycol dimethacrylate (EGDMA) and trimethylolpropane trimethacrylate (TMPTMA), can be used as comonomers in relatively small amounts in the reaction mixture to improve the dimensional stability and other physical properties of the lens. Similarly, other components may be added for specific applications, for example, to impart UV absorbing properties to the lens.
The monomer reaction mixture also includes an initiator, usually from about 0.05 to 1 percent of a free radical initiator which is thermally activated. Typical examples of such initiators include lauroyl peroxide, benzoyl peroxide, isopropyl percarbonate, azobisisobutyronitrile and known redox systems such as the ammonium persulfate-sodium metabisulfite combination and the like. Irradiation by ultraviolet light, electron beam or a radioactive source may also be employed to initiate the polymerization reaction, optionally with the addition of a polymerization initiator, e.g. benzoin and its ethers.
The polymerization of the monomer reaction mixture is carried out after the mixture is contacted with the required amount of the reactive dye, and a homogeneous solution of the dye in the mixture is formed. The amount of time required to form the homogeneous solution can be readily determined empirically.
The amount of reactive dye added to the reaction mixture is an amount of dye effective to impart the desired degree of tinting or coloring to the lens. This amount can be readily determined empirically, and will depend on the thickness of the periphery of the lens, the components of the reactive monomer mixture, as well as other factors.
Preferably, the improved method of this invention is used to impart a visibility or handling tint to the lens. This is an amount which enables a wearer to visibly notice the lens during handling if temporarily misplaced, but the amount should not be such that the colored periphery of the lens is easily distinguishable from the cornea of the wearer during use. The amount of reactive dye added to the homogeneous solution before polymerization to achieve a desired visibility tint will depend significally on the purity of the dye added to the solution and therefore it should be determined empirically. Generally, it should range from about 0.01 to about 0.35 percent based on the weight of the hydrophilic monomer, preferably from about 0.01 to about 0.20 weight percent, when the dye added has at least 20 weight percent of active dye compounds. The most preferred range is from about 0.05 to about 0.15 percent.
Alternatively, the improved method of this invention offers the flexibility to impart an enhancement tint to the lens. An enhancement tint simply enhances the wearer's original eye color so that, for example, blue eyes will appear more "blue" with the enhancement tint on the lens. The amount of reactive dye added to the homogeneous solution for an enhancement tint desirably ranges from about 0.35 to about 0.75 percent based on the weight of the hydrophilic monomer, preferably from about 0.35 to about 0.50 percent, when the dye added has at least 20 weight percent of active dye compounds.
The polymerization can be carried out in the presence or absence of an inert diluent. If the polymerization is carried out in the absence of a diluent the resulting polymeric composition can be formed, as for example by lathe cutting, into the desired lens shape, and then swollen with the requisite amount of water following this operation. Alternatively, and more preferably, the polymerization is carried out in the presence of a suitable inert diluent. The preferred inert diluent is a water-displaceable boric acid ester. The characteristics of desired boric acid esters as well as the preferred concentration of ester in the polymerization reaction mixture is described in detail in U.S. Pat. No. 4,680,336, which is incorporated by reference herein. The preferred methods for forming the desired lens when a diluent is used include centrifugal casting and cast molding, for example using molds described in U.S. Pat. No. 4,565,348, as well as combinations of these methods with the other methods described generally herein.
When the polymerization reaction to prepare the lens is sufficiently complete, the lens can be hydrated to its equilibrium water content. Preferably, the water content of the lens will range from about 35 to about 80 weight percent, more preferably from about 55 to about 65 weight percent. This range is considered ideal for extended wear applications where patient comfort and handling characteristics are critical properties.
The following Example is intended to illustrate the claimed invention and are not in any way designed to limit its scope. Numerous additional embodiments within the scope and spirit of the claimed invention will become apparent to those skilled in the art.
The components used in the preparation of the contact lenses of the Example are abbreviated as follows: 2-hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA), ethyleneglycol dimethacrylate (EGDMA), boric acid ester of glycerin (0.16 moles boron per mole of glycerin) (GBAE), an ethoxylated methylglucosidilaurate (MLE-80), Reactive Blue #4 2-anthracenesulfonic acid, 1-amino-4-(3-(4,6-dichloro-s-triazin-2-yl)amino)-4-sulfoanilino)-9,10-dihydro-9,10-dioxo! (RB4) which is a dichlorotriazine dye, and α-hydroxy-α, α-dimethylacetophenone (Darocur 1173) which is a UV reactive initiator. The HEMA used in all of the examples is highly purified HEMA with less than 0.1 wt % impurities.
The test methods for determining the physical and optical properties set forth in Table 1 of the Example are as follows:
Oxygen Permeability
The oxygen permeability through the lens is expressed as the Dk value multiplied by 10 -11 , in units of cm.ml 0 2 /sec.ml.mm Hg. It is measured using a polarographic oxygen sensor consisting of a 4 mm diameter gold cathode and silver-silver chloride ring anode.
Tensile Properties (Modulus, Elongation and Strength)
The lens to be tested is cut to the desired specimen size and shape and the cross-sectional area measured. The specimen is then attached into the upper grip of a constant rate-of-crosshead-movement type of testing machine equipped with a load cell. The crosshead is lowered to the initial gauge length and the specimen attached to the fixed grip. The specimen is then elongated at a constant rate of strain and the resulting stress-strain curve is recorded. The elongation is expressed in percent and the tensile modulus and strength is expressed in psi (pounds per square inch).
UV Transmission
This method is applicable to the determination of light transmission through the lens. A beam of light (200-800 nm) is passed through a quartz cell containing the lens in solution. The intensity of light exiting the cell is measured and ratioed against the incident (reference) beam. The values are express in % transmission.
Tint Stability
The lens is sterilized in an autoclave for 30 mins and qualitatively compared to a non-autoclaved lens for loss of tint intensity. This procedure is repeated 5 times and a lens which does not lose tint intensity passes the test.
EXAMPLE
Synthesis of Reactive Dye RB4
To a 500 ml round bottom flask is placed 350 ml of a 5% solution of K 2 CO 3 . To this is added 0.10 moles of HEMA, and the mixture is stirred for 10 minutes. To the above solution is added 0.08 mole of RB4. After the dye is fully dispersed, the temperature is raised between 40-50° C. The reaction is followed using the chromatographic HPLC method described in Hanggi et al, Analytical Biochemistry 149, 91-104 (1985), for monitoring the reaction of chlorotriazine dyes with monofunctional alcohols. Using this method, the formation of the monosubstituted monochlorotriazine--HEMA reactive dye is seen at approximately 42 minutes.
When sufficient conversion is achieved after 40-50 hours, the reaction mixture can be filtered and the filter cake collected and dried. This filter cake can be used "as is" to tint contact lenses. The filtrate can be vacuum stripped using a rotary evaporator to remove the water from the reaction product. The remaining blue powder can be used to tint lenses. The inorganics can be removed depending on the requirements of the tint. The conversion of the halotriazine can be increased by decreasing the amount of water in the reaction mixture. This would also increase the amount of the difunctional derivative of the dye.
Preparation of Tinted Contact Lens with High Water Content
The following components are mixed to form a homogeneous blend: 58.08 parts HEMA, 0.71 parts EGDMA, 0.96 parts MAA, 0.14 parts Darocur 1173. 0.07 parts of the UV-Reactive RB4 synthesized as described above, and 40 parts GBAE. The above blend is polymerized by exposure to UV light while being contained in a contact lens mold. The mold is opened after the polymerization is complete, the molded lens is submerged in either an aqueous solution of 0.50 percent MLE-80 or a 0.90% NaCl solution to which 0.50 percent MLE-80 has been added. The molds are put into the above solutions at a solution temperature between 60-70° C. The physical and optical properties of this tinted lens are shown in Table 1 as Example 1.
For comparison purposes, the physical and optical properties of an untinted lens, and a lens tinted using the conventional method, are shown in Table 1 as Control Examples A and B respectively. The untinted lens is prepared substantially identically to the method described above except no dye is used. The lens tinted using the conventional method is prepared by first soaking the untinted lens in a solution of RB4 containing 0.50 percent MLE-80, and then bonding the RB4 to the soaked lens by contact with aqueous base prior to final hydration.
TABLE 1______________________________________Physical and Optical Properties of Tinted Contact Lenses Control ControlProperties Example 1 Example A Example B______________________________________Physical PropertiesWater Content % 60 60 60Oxygen Permeability 28 26 28Tensile Modulus, psi 36 36 34Elongation, % 120 118 128Tensile Strength, psi 32 35 34Optical PropertiesUV Transmission 85 85 85Minimum %Tint Stability yes -- yes______________________________________
The results shown in Table 1 illustrate that the physical and optical properties of the tinted contact lens made according to the improved method of the invention are substantially the same as those properties for the corresponding untinted contact lens and the contact lens tinted by the conventional process. | An improved method for imparting a tint or color to a soft, hydrogel contact lens by uniformly dispersing a dye throughout the lens. The dye is a water-soluble halotriazine dye. The dye is reacted with a hydrophilic monomer to prepare a reactive dye containing predominantly monofunctionality. The monomer is then subjected to polymerization in the presence of a homogeneous solution of the reactive dye in the monomer under conditions to yield the hydrophilic polymer from which the lens is formed. The dye becomes bonded to the polymer during polymerization. The finished lens does not require soaking in an aqueous solution of the dye to impart the desired tint or color to the lens. Additionally, the dye uniformly dispersed throughout the lens according to the improved method does not leach out of the lens or migrate within the lens. Furthermore, the lens does not need to be washed with aqueous base to bond the dye to the lens. | 3 |
RELATED APPLICATIONS
[0001] This application is a continuation-in-part, under 35 U.S.C. § 120, of International Patent Application No. PCT/ZA2004/000054, filed on May 19, 2004 under the Patent Cooperation Treaty (PCT), which was published by the International Bureau in English on Nov. 25, 2004, which designates the U.S. and claims the benefit of South African Provisional Patent Application No. 2003/3844, filed May 19, 2003, the disclosures of which are hereby incorporated by reference in their entireties and are made a portion of this application.
FIELD OF THE INVENTION
[0002] The invention relates to a hydrocarbon composition for use in Compression Ignition (CI) engines and to a process related to its preparation.
BACKGROUND TO THE INVENTION
[0003] There has been considerable discussion within the European Union (EU) since the late eighties on strategies and programmes to improve air quality. The EU motor vehicle emission regulations and fuel specifications subsequently became tighter with current EURO 3 emission limits for carbon monoxide (CO), hydrocarbons (HC)+nitrogen oxides (NOx) and particulate matter (PM) of 0.64 g/km, 0.56 g/km and 0.05 g/km respectively for passenger vehicles. Fuel with low sulphur and aromatic contents would improve PM emissions. Although fuel sulphur does not influence NOx emissions directly, its elimination from the fuel enables the use of NOx after-treatment methods in new vehicles. Californian Air Resources Board (CARB) diesel and Swedish Environmental Class 1 (EC1) diesel are examples of fuels with a low sulphur and low polycyclic aromatic hydrocarbon (PAH) content that are available in the market.
[0004] The highly paraffinic related properties of Sasol Slurry Phase Distillate™ (Sasol SPD™) Low Temperature Fischer-Tropsch (LTFT) derived diesel, also known as Gas-to-Liquid (GTL) diesel, such as high H:C ratio, high cetane number and low density together with virtually zero-sulphur and very low aromatics content give Sasol SPD™ diesel its very good emission performance advantage over crude oil-derived diesel. Compared to CARB diesel and Swedish EC1 diesel, Sasol SPD™ diesel has the lowest regulated and unregulated exhaust emissions.
[0005] The LTFT process is a well known process in which synthesis gas, a mixture of gases including carbon monoxide and hydrogen, are reacted over an iron, cobalt, nickel or ruthenium containing catalyst to produce a mixture of straight and branched chain hydrocarbons ranging from methane to waxes with molecular masses above 1400 and smaller amounts of oxygenates. The LTFT process may be derived from coal, natural gas, biomass or heavy oil streams as feed. While the term Gas-to-Liquid (GTL) process refers to schemes based on natural gas, i.e. methane, to obtain the synthesis gas, the quality of the synthetic products is essentially the same once the synthesis conditions and the product work-up are defined. As a matter of reference, the Sasol SPD™ process is a well known LTFT scheme and is also one of the leading GTL conversion technologies.
[0006] Some reactors for the production of heavier hydrocarbons using the LTFT process are slurry bed or tubular fixed bed reactors, while operating conditions are generally in the range of 160-280° C., in some cases in the 210-260° C. range, and 18-50 bar, in some cases between 20-30 bar. The molar ratio of Hydrogen to Carbon Monoxide in the synthesis gas may be between 1.0 and 3.0, generally between 1.5 and 2.4.
[0007] The LTFT catalyst may comprise active metals such as iron, cobalt, nickel or ruthenium. While each catalyst will give its own unique product slate, in all cases it includes some waxy, highly paraffinic material which needs to be further upgraded into usable products. The FT products are typically hydroconverted into a range of final products, such as middle distillates, naphtha, solvents, lube oil bases, etc. Such hydroconversion, which usually consists of a range of processes such as hydrocracking, hydrotreatment and distillation, can be termed a FT products work-up process.
[0008] The complete process can include gas reforming which converts natural gas to synthesis gas (H 2 and CO) using well-established reforming technology. Alternatively, synthesis gas can also be produced by gasification of coal or suitable hydrocarbonaceous feedstocks like petroleum based heavy fuel oils. Other products from this unit include a gas stream consisting of light hydrocarbons, a small amount of unconverted synthesis gas and a water stream. The waxy hydrocarbon stream is then upgraded in the third step to middle distillate fuels such as diesel, kerosene and naphtha. Heavy distillates are hydrocracked and olefins and oxygenates are hydrogenated to form a final product that is highly paraffinic.
[0009] As it is the case with the LTFT process, the High Temperature Fischer-Tropsch (HTFT) process also makes use of the FT reaction albeit at a higher process temperature. A typical catalyst for HTFT process, and the one considered herebelow, is iron based.
[0010] Known reactors for the production of heavier hydrocarbons using the HTFT process are the circulating bed system or the fixed fluidized bed system, often referred in the literature as Synthol processes. These systems operate at temperatures in the range 290-360° C., and typically between 310-340° C., and at pressures between 18-50 bar, in some cases between 20-30 bar. The molar ratio of Hydrogen to Carbon Monoxide in the synthesis gas is essentially between 1.0 and 3.0, generally between 1.5 and 2.4.
[0011] Products from the HTFT process are somewhat lighter than those derived from the LTFT process and, as an additional distinction, contain a higher proportion of unsaturated species.
[0012] The HTFT process is completed through various steps which include natural gas reforming or gasification of coal or suitable hydrocarbonaceous feedstocks like petroleum based heavy fuel oils to produce synthesis gas (H 2 and CO). This is followed by the HTFT conversion of synthesis gas in a reactor system like the Sasol Synthol or the Sasol Advanced Synthol. One of the products from this synthesis is an olefinic distillate, also known as Synthol Light Oil (SLO). This SLO is fractionated into naphtha and distillate fractions. The distillate fraction of SLO is further hydrotreated and distilled to produce at least two distillates boiling in the diesel range: a Light and a Heavy product. The former is also known as Hydrotreated Distillate (DHT) diesel and the latter as a Distillate Selective Cracked (DSC) heavy diesel.
[0013] The HTFT derived DHT diesel also contains ultra-low sulphur levels, has a cetane number greater than fifty and a density that meets current European National Specifications for Special Low Sulphur and Low Aromatics Grade Diesel Fuel with a mono-aromatic content of ±25 vol %.
[0014] Description of these two FT processes, LTFT and HTFT, may be found in Appl Ind Catalysis vol. 2 chapter 5 pp 167-213 (1983), amongst others.
[0015] Material compatibility in fuel systems is a concern whenever fuel composition changes. Exposure of an elastomer that has been exposed to high aromatic fuel and then to low aromatic, severely hydrotreated fuel, may cause leaching of absorbed aromatics, causing it to shrink. If the elastomer is still pliable, this shrinkage will not cause a leak, but an aged elastomer will loose its elasticity and a leak may occur. It is therefore not the low aromatic hydrocarbon diesel that causes fuel system leaks, but the combination of a change from higher to lower aromatics fuel. The above was confirmed with the ageing of nitrile rubber and Viton® in LTFT derived diesel and US No. 2-D diesel without pre-conditioning.
SUMMARY OF THE INVENTION
[0016] Thus, according to a first aspect of the invention, there is provided a hydrocarbon composition for use in CI engines, said composition comprising a blend of hydrocarbons derived from a LTFT and from a HTFT process, said LTFT derived hydrocarbon being blended with said HTFT derived hydrocarbon in a volumetric ratio of from 1:20 to 20:1.
[0017] The LTFT:HTFT ratio may be from 1:8 to 8:1.
[0018] The LTFT:HTFT ratio may be from 1:4 to 4:1.
[0019] The LTFT:HTFT ratio may be from 1:2 to 2:1.
[0020] The LTFT:HTFT ratio may be 1:1.
[0021] The hydrocarbon composition may have an aromatics content of above 1% by mass, typically above 3% by mass.
[0022] The hydrocarbon composition may have an aromatics content in excess of 9% by mass.
[0023] The aromatics content comprises mostly the least harmful mono-aromatics species which are derived primarily from the HTFT component of the blend.
[0024] The hydrocarbon composition may have a density of above 0.78 kg/m 3 @15° C.
[0025] The net heating value of the hydrocarbon composition may be between 43.0 and 44.0 MJ/kg on a mass basis or 33.5 to 35.0 MJ/l on a volume basis.
[0026] The hydrogen content may be from 13.5 mass % to 15 mass %
[0027] The hydrogen to carbon ratio of the hydrogen composition may be from 1.8 mol/mol to 2.2 mol/mol
[0028] The hydrocarbon composition may have an initial boiling point as measured according to the ASTM D86 method above 150° C. and T95 below 360° C.
[0029] The hydrocarbon composition may have a final boiling point as measured according to the ASTM D86 method of below 390° C.
[0030] The hydrocarbon composition may have a bromine number below 10.0 g Br/100 g.
[0031] The hydrocarbon composition may have an acid number below 0.006 mg KOH/g.
[0032] The hydrocarbon composition may have an Oxidation Stability below 0.7 mg/100 ml insolubles formed.
[0033] The hydrocarbon composition may be stable over two years with the total amount of insolubles formed being less than 1.35 mg/100 ml and an acid number less than 0.02 mgKOH/g.
[0034] The hydrocarbon composition may have a water content below 0.005% on a volume basis.
[0035] The hydrocarbon composition may be benign to elastomers used in CI engines and which have been exposed to crude oil derived diesel fuels.
[0036] The invention extends to a fuel composition including from 1% to 99% by volume of a hydrocarbon composition as described above.
[0037] The fuel composition may include 15% by volume of the hydrocarbon composition as described above.
[0038] The fuel composition may be a CI engine fuel composition.
[0039] According to another aspect of this invention, the fuel composition may include, in addition to the hydrocarbon composition, one or more component selected from the group including a crude oil derived diesel fuel, a crude oil derived naphtha, a lubricant or light cycle oil (LCO).
[0040] According to yet a further aspect of the invention there is provided a process for the production of a hydrocarbon composition for use in CI engines, said process including the steps of:—
[0000] a. producing one or more synthesis gas products from solid, liquid or gaseous carbonaceous feedstock by one or more synthesis gas production process;
[0000] b. optionally, blending two or more synthesis gas products to produce a synthesis gas blend for a synthesis gas reaction process;
[0000] c. processing the synthesis gas product or synthesis gas blend by a High Temperature Fischer-Tropsch synthesis process to produce synthetic hydrocarbon and water;
[0000] d. processing synthesis gas or synthesis gas blend by a Low Temperature Fischer-Tropsch synthesis process to produce synthetic hydrocarbon and water;
[0000] e hydroconverting at least a fraction of the hydrocarbon of step c. to produce one or more HTFT process derived hydrocarbons in the boiling range 150° C. to 390° C. for blending to produce a hydrocarbon composition for use as a fuel in a C1 engine;
[0041] f. hydroconverting at least a fraction of the hydrocarbon of step d. to produce one or more LTFT process derived hydrocarbons in the boiling range 150° C. to 390° C. for blending to produce a hydrocarbon composition for use as a fuel in a C1 engine; and
[0000] g blending the hydrocarbons produced in steps e and f to form the hydrocarbon composition.
[0042] The hydrocarbon composition may be prepared by blending a LTFT process derived hydrocarbon with a HTFT derived hydrocarbon.
[0043] The process may include the step of blending two or more of the hydrocarbons in the boiling range 150° C. to 390° C. to produce the hydrocarbon composition for use in C1 engines.
[0044] The synthesis gas may be produced by reforming natural gas.
[0045] The synthesis gas may be produced by gasification of suitable hydrocarbon feed stock, for example, coal.
[0046] The synthetic hydrocarbon may be an olefinic hydrocarbon.
[0047] The synthetic hydrocarbon may be a hydrocarbon suited for conversion to distillate range hydrocarbons.
[0048] Two of the hydrocarbons produced by the hydrocarbon processes may be a DHT diesel and a Sasol SPD™ diesel.
[0049] The DHT diesel is an example of HTFT derived hydrocarbons and GTL diesel is an example of LTFT derived hydrocarbons.
[0050] The DHT diesel and Sasol SPD™ diesel may be blended at a ratio from 1:100 to 100:1 on a volume basis.
[0051] The DHT diesel and Sasol SPD™ diesel may be blended at a ratio from 1:40 to 40:1 on a volume basis.
[0052] The DHT diesel and Sasol SPD™ diesel may be blended at a ratio from 1:20 to 20:1 on a volume basis.
[0053] The synthesis gas feeds produced from the reforming of natural gas and gasification may be blended prior to synthesis gas reaction process in a ratio of 1:100 to 100:1 on a volume basis.
[0054] The synthesis gas feeds produced from the reforming of natural gas and gasification may be blended prior to synthesis gas reaction process in a ratio of 1:40 to 40:1 on a volume basis.
[0055] The LTFT synthetic hydrocarbon and HTFT synthetic hydrocarbon produced from the LTFT synthesis gas reaction process and HTFT synthesis gas reaction process respectively may be blended prior to hydroconversion in a ratio of 1:100 to 100:1 on a volume basis.
[0056] The LTFT synthetic hydrocarbon and HTFT synthetic hydrocarbon produced from the LTFT synthesis gas reaction process and HTFT synthesis gas reaction process respectively may be blended prior to hydroconversion in a ratio of 1:40 to 40:1 on a volume basis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] FIG. 1 shows a linear relationship of fuel density with various Sasol SPD™ diesel-DHT diesel blends.
[0058] FIG. 2 shows gravimetrical and volumetric net heating values of hydrocarbon compositions of the invention.
[0059] FIG. 3 shows a distillation profile of Sasol SPD™ diesel and DHT diesel.
[0060] FIG. 4 shows a linear cetane number relationship of hydrocarbon compositions of the invention.
[0061] FIG. 5 shows percentage change in mass and thickness of new nitrile rubber dumbbells, pre-conditioned in US No. 2-D and then further aged in a hydrocarbon composition comprising DHT/Sasol SPD™ diesel and US No. 2-D diesel.
[0062] FIG. 6 shows percentage change in tensile strength of nitrile rubber dumbbells, pre-conditioned in US No. 2-D and then further aged in a hydrocarbon composition of the invention and US No. 2-D diesel.
[0063] FIG. 7 shows: Percentage change in hardness of nitrile rubber dumbbells, pre-conditioned in US No. 2-D and then further aged in the hydrocarbon composition of the invention and US No. 2-D diesel.
[0064] FIG. 8 provides a schematic representation of a process for producing hydrocarbons according to the preferred embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0065] The hydrocarbon composition of the invention was prepared by blending a LTFT process derived hydrocarbon with a HTFT derived hydrocarbon.
[0066] In the examples that follow the following abbreviations have been used:
[0067] DHT—refers to the hydroconversion process used primarily to upgrade the distillate contained in the HTFT SLO.
[0068] DHT Diesel—it refers to a HTFT process derived hydrocarbon which has been hydrotreated.
[0069] GTL—This is a LTFT process based on natural gas that optionally can also make use of alternative hydrocarbonaceous feeds to produce synthesis gas.
[0070] Sasol Slurry Phase Distillate™ (Sasol SPD™) diesel or GTL diesel—it refers to a LTFT process derived hydrocarbon that is fully hydroconverted.
[0071] Two base fuels were used to prepare five hydrocarbon compositions including Sasol SPD™ diesel and DHT diesel for this investigation.
[0072] The experimental blends contained mixtures of 15%, 30%, 50%, 70% and 85% by volume Sasol SPD™ diesel with the DHT diesel. The properties of the neat Sasol SPD™ diesel and DHT diesel and blends thereof are summarised in Table 1, 2, 3 and 4. An example of the fuel properties of the Fischer-Tropsch hydrocarbon compositions of the invention and crude oil derived diesel (US 2-D diesel) blends are also tabulated as illustrated in Table 5.
TABLE 1 Selected properties of Sasol SPD ™ - DHT Hydrocarbon Compositions 15% 30% 50% 70% 85% Sasol DHT Sasol Sasol Sasol Sasol Sasol SPD ™ Analysis Units Method diesel SPD ™ SPD ™ SPD ™ SPD ™ SPD ™ diesel Colour ASTM 1 1 1 1 1 <1 <1 D1500 Appearance Caltex 1 1 1 1 1 1 1 CMM76 Density @ kg/l ASTM 0.809 0.803 0.797 0.789 0.781 0.775 0.769 15° C. D4052 Distillation ASTM D86 IBP ° C. 184 180 166 159 153 152 151 T10 ° C. 208 205 200 195 189 184 182 T50 ° C. 239 242 242 243 245 246 249 T95 ° C. 363 359 351 343 336 330 325 FBP ° C. 385 385 379 367 358 345 334 Flash point ° C. ASTM 78 74 72 66 63 60 58 D93 Viscosity @ cSt ASTM 2.14 2.11 2.10 2.07 2.03 2.01 1.97 40° C. D445 CFPP ° C. IP 309 0 −1 −3 −6 −11 −20 −19 Water vol % ASTM 0.003 0.003 0.004 0.003 0.003 0.003 0.003 D1744 Sulphur mass % ASTM 0.0003 0.0002 0.0002 <0.0001 <0.0001 <0.0001 <0.0001 D5453 Acid mgKOH/g ASTM 0.004 0.005 0.003 0.004 0.002 0.002 0.001 number D664 Total Mass % 23.88 20.32 16.76 12.01 7.26 3.70 0.14 Aromatics (HPLC) Cetane ASTM 57 59 61 66 67 69 73 Number D613 Oxidation mg/100 ml ASTM 0.5 0.5 0.5 0.4 0.3 0.3 0.6 Stability D2274 Bromine gBr/100 g IP 129 9.4 8.2 6.7 5.4 3.2 1.9 0.6 Number Long term mgKOH/g ASTM 0.008 0.007 0.008 0.008 0.006 0.009 0.013 Storage D4625 stability Acid number Total mg/100 ml 0.68 0.63 0.45 0.96 1.31 0.53 0.35 insolubles
[0073]
TABLE 2
Heating values of DHT-Sasol SPD ™ Hydrocarbon Compositions
15%
30%
50%
70%
85%
Sasol
DHT
Sasol
Sasol
Sasol
Sasol
Sasol
SPD ™
diesel
SPD ™
SPD ™
SPD ™
SPD ™
SPD ™
diesel
Gross heating value (MJ/kg)
46.037
46.248
46.331
46.816
46.845
46.954
46.964
Net Heating Value (MJ/kg)
43.164
43.368
43.422
43.775
43.774
43.818
43.787
Hydrogen content (mass %)
13.54
13.57
13.71
14.33
14.47
14.78
14.97
Density @ 15° C. (kg/l)
0.8092
0.8031
0.7971
0.7888
0.7806
0.7747
0.7685
Net heating value (MJ/l)
34.928
34.829
34.611
34.530
34.170
33.946
33.651
H:C ratio (mol/mol)
1.87
1.87
1.90
1.98
2.01
2.06
2.10
[0074]
TABLE 3
High-frequency reciprocating rig (HFRR)
and scuffing load ball-on-cylinder
(SL BOCLE) lubricity evaluation of Sasol
SPD ™ - DHT Hydrocarbon Compositions
15%
30%
50%
70%
85%
Sasol
DHT
Sasol
Sasol
Sasol
Sasol
Sasol
SPD ™
diesel
SPD ™
SPD ™
SPD ™
SPD ™
SPD ™
diesel
HFRR
547
549
552
556
560
612
617
(WSD
μm)
SL
4400
2800
2800
2800
2500
1700
1500
BOCLE
load
(g)
[0075] Another property which was considered was the heating value of the hydrocarbon compositions. There are two values, Gross (or High) and Net (or Low) commonly quoted which vary according to whether the water content in the products of combustion is considered to be in liquid or gaseous form. The gross heating values (Q gross ) of the Sasol SPD™ diesel—DHT diesel blends were determined according to the American Society for Testing and Material (ASTM) D240 test method. The net heating value (Q nett ) per mass was calculated using the following equation:
Q nett 25° C. =Q gross 25° C. −0.2122 ×H (mass %)
where the difference between the two values is a function of the latent heat of condensation of water and hydrogen content of the composition. Table 2 shows these results.
[0076] The issue of lubricity is pertinent in the case of severely hydrotreated low-sulphur diesel.
[0077] There are two common methods of assessing lubricity; namely the Scuffing Load Ball-On-Cylinder (SL BOCLE) method and the HFRR. Lubricity evaluation tests of the various hydrocarbon compositions are shown in Table 3 and conducted according to both the ASTM D6078 and ASTM D6079 test methods.
[0078] Finally, the long-term storage stability of the neat Sasol SPD™ diesel and DHT diesel and hydrocarbon compositions comprising blends thereof was investigated according to the standard ASTM D4625 test method. The acid number and total insolubles formed over a period of 24 weeks at 43° C. were measured and reported to be smaller than 0.02 mgKOH/g and 1.35 mg/100 ml respectively.
[0079] The Bromine number (IP 129 Procedure), the Acid number (ASTM D694 test method), Oxidation Stability (ASTM D2274) and the water content (ASTM D1744 test method) of the fuel and the proposed blends were also measured and the results are shown in Table 1. It is evident that in all blends of DHT diesel and Sasol SPD™ diesel, the following measured quality characteristics apply:
[0000] 1—Bromine number below 10.0 g Br/100 g. This is an indication of the residual olefin in the product. Olefinic compounds are susceptible to gum formation and are less stable.
[0000] 2—Acid number below 0.004 mg KOH/g. This is an indication of, mostly, the residual organic acids and alcohols in the product and the tendency of the fuel to corrode.
[0080] 3—Oxidation Stability below 0.6 mg/100 ml. Oxygen stability is tested through the calculation of the amount of insolubles formed in the presence of oxygen. This is an indication of the behaviour of the fuel when exposed to atmospheric oxygen under standard storage conditions and measures the fuel's resistance to degradation.
[0000] 4—Water content below 0.004% on a volume basis. This is an indication of the quality of the final fractionated product. Entrained water can form stable emulsions and suspended matter, which cloud plug filters.
[0081] Characterisation and quantification of the composition of the neat Sasol SPD™ diesel and DHT diesel was obtained through Fluorescent Indicator Adsorption (FIA) and High Performance Liquid Chromatography (HPLC) (see Table 4).
TABLE 4 Sasol SPD ™ diesel and DHT diesel hydrocarbon components Sasol Component SPD ™ DHT Total Aromatics (vol %) <1 24 Mono-aromatics (mass %) 0.1439 23.658 Dicyclic-aromatics (mass %) <0.0001 0.118 Polycyclic-aromatics (mass %) <0.0001 0.104 Olefins (vol %) 2 1 Paraffins (vol %) 98 75
[0082] The diesel properties that are most important to ensure good engine performance and which influence emissions include cetane number, aromatics, density, heat content, distillation profile, sulphur, viscosity, and cold flow characteristics. These properties, among others, will be discussed below for the hydrocarbon compositions.
[0083] DENSITY—Diesel density specifications are tending to become tighter. This is due to the conflicting requirements of a lower density fuel to reduce particulate matter emissions, whilst retaining a minimum density to ensure adequate heat content, which relates to fuel economy. Increasing ratios of DHT to Sasol SPD™ diesel would increase the hydrocarbon composition density, even beyond the minimum requirement of 0.800 kg/l, but not higher than its upper specified limit of 0.845 kg/l@ 15° C. (see FIG. 1 ).
[0084] FIG. 1 shows a linear relationship of fuel density with various Sasol SPD™ diesel—DHT diesel blends.
[0085] HEATING VALUES—Fischer-Tropsch synthetic fuels have much higher gravimetrical heating values than severely hydrotreated crude derived diesel and lower net volumetric heating values. Aromatic compounds have a much higher density and volumetric heating value than naphthenes or paraffins with the same carbon number. The net volumetric heating value of the hydrocarbon composition increases with increasing DHT diesel content. The net volumetric heating value of the composition containing equal amounts of Sasol SPD™ and DHT is 34.5 MJ/l (see FIG. 2 ).
[0086] FIG. 2 shows gravimetrical and volumetric net heating values of hydrocarbon compositions of the invention
[0087] VISCOSITY—A fuel viscosity that is excessively low causes the injection spray not to penetrate far enough into the cylinder and could cause idling and hot start problems whereas high viscosity reduces fuel flow rates. All the hydrocarbon compositions described above are within the EN 590:1999 Diesel Specification viscosity requirement.
[0088] DISTILLATION PROFILE—DHT diesel has a much higher initial boiling point (IBP) than Sasol SPD™ diesel (see DHT diesel distillation profile in FIG. 3 ) and therefore a higher flash point than that of Sasol SPD™ diesel. The hydrocarbon compositions of the invention comply with the EN 590:1999 T95 Diesel Specification. Fuels with higher end points tend to have worse cold flow properties than fuels with lower final boiling points and therefore the low maximum T95 limit for arctic grade diesel. Sasol SPD™ diesel on the other hand has good cold flow properties as well as a high cetane number because of the predominately mono- and to a lesser extent di-methyl branching of the paraffins. Sasol SPD™ diesel improves the cold flow properties of DHT diesel with its higher T95 to meet the European Summer Climate Grade CFPP values of −5° C. and −10° C.
[0089] FIG. 3 shows a distillation profile of Sasol SPD™ diesel and DHT diesel.
[0090] CETANE NUMBER—Sasol SPD™ diesel, with a cetane number rating of 72, improves the 57 cetane number of DHT diesel linearly (see FIG. 4 ). Fuels with a high cetane number ignite quicker and hence exhibit a milder uncontrolled combustion because the quantity of fuel involved is less. A reduction of the uncontrolled combustion implies an extension of the controlled combustion, which results in better air/fuel mixing and more complete combustion with lower NOx emissions and better cold start ability. The shorter ignition delay implies lower rates of pressure rise and lower peak temperatures and less mechanical stress. The cetane numbers of the hydrocarbon compositions of the present invention are far beyond all specification requirements.
[0091] FIG. 4 shows a linear cetane number relationship of hydrocarbon compositions of the invention.
[0092] Other excellent properties of hydrocarbon compositions of the invention include their ultra-low sulphur content (less, than 5 ppm), no unsaturates or polycyclic aromatic hydrocarbons, low bromine number. According to the very low acid number and water content observed, the likelihood of the hydrocarbon compositions of the invention to corrode are very slim.
TABLE 5 Selected properties of Sasol SPD ™ - DHT Hydrocarbon Compositions blends with US 2-D diesel Sasol SPD ™:DHT:US 2-D volumetric blend ratio Analysis Units Method US2-D 0.3:0.7:1 0.7:0.3:1 1:1:1 2:2:1 Density @ kg/l ASTM D4052 0.861 0.8293 0.8210 0.813 0.8033 15° C. Distillation ASTM D86 IBP ° C. 147 167 155 156 154 T10 ° C. 215 206 200 200 198 T50 ° C. 268 256 257 252 249 T95 ° C. 340 344 339 342 343 FBP ° C. 353 372 355 362 363 Flash point ° C. ASTM D93 69 66 60 67 59 Viscosity @ cSt ASTM D445 2.60 2.34 2.30 2.24 2.17 40° C. CFPP ° C. IP 309 −14 −7 −12 −8 −7 Sulphur mass % ASTM D5453 0.04 0.021 0.021 0.014 0.0086 Cetane no. ASTM D613 41 52 56 59 62 Lubricity (WSD μm) ASTM D6079 293 423 427 468 503 (HFRR) Total mass % 34.44 25.93 21.48 19.88 16.77 aromatics
[0093] ELASTOMER COMPATIBILITY—The effect of mono-aromatics in Sasol SPD™ diesel on the physical properties of seals was studied with a hydrocarbon composition comprising 50 vol % DHT with 50 vol % Sasol SPD™ (FT blend). The physical properties of the untreated elastomers were taken as baseline. The overall change in mass, thickness, tensile strength and hardness of pre-conditioned standard nitrile rubber being exposed to the composition was compared with nitrile rubber being exposed to the base fuels. The nitrile rubber, an acrylonitrile butadiene copolymer, was pre-conditioned in highly aromatic US No. 2-D diesel for 166 hours according to the ASTM test method for Rubber Property—Effect of Liquids (ASTM D471), Vulcanised Rubber and Thermoplastic Elastomers—Tension (ASTM D412) and Durometer Hardness (ASTM D 2240) respectively. Average mass change, change in thickness, tensile strength and hardness of five new dumbbells, pre-conditioned and thereafter exposed to US No. 2-D, Fischer-Tropsch diesel and a blend thereof are tabulated in Table 6.
TABLE 6 Percentage physical property change of new nitrile rubber, pre-conditioned in US 2-D diesel and further exposed to hydrocarbon composition samples. Sasol SPD ™ Fuel US No. 2-D DHT diesel diesel FT blend Mass 10.01 0.60 −4.12 −1.50 Thickness 6.98 1.89 1.24 0.75 Tensile −38.81 −35.88 −25.80 −26.04 strength Hardness −10.20 −5.77 −2.68 −4.70
[0094] MASS AND DIMENSION CHANGE—Ageing of nitrile rubber in the Sasol SPD™ diesel caused the swollen pre-conditioned dumbbells to shrink and to loose weight (see FIG. 5 ). This effect was reduced with the blend of DHT and Sasol SPD™ causing the nitrile rubber to return to its original thickness and within 1.5% of its original mass. Exposure of the pre-conditioned nitrile rubber for another 166 hours to US No. 2-D diesel causes a total increase of 10% in the mass of new dumbbells. According to Chemical Resistance Guide for Elastomers II, if loss in dimensions are smaller than 15% from 30 days to one year, the description of attack can still be seen as excellent and little surface deterioration.
[0095] FIG. 5 shows percentage change in mass and thickness of new nitrile rubber dumbbells, pre-conditioned in US No. 2-D and then further aged in a hydrocarbon composition comprising DHT/Sasol SPD™ diesel and US No. 2-D diesel.
[0096] TENSILE STRENGTH—All the diesel samples softens new elastomers. The Sasol SPD™ diesel hardens the pre-conditioned nitrile rubber dumbbells and therefore increases its tensile strength (see FIG. 6 ). The mono-aromatic hydrocarbon content of the DHT diesel reduces the tensile strength of the nitrile rubber to a lesser extent than that of US No. 2-D diesel.
[0097] FIG. 6 shows percentage change in tensile strength of nitrile rubber dumbbells, pre-conditioned in US No. 2-D and then further aged in a hydrocarbon composition of the invention and US No. 2-D diesel.
[0098] HARDNESS—Exposure of nitrile rubber to the hydrocarbon composition of the invention makes indentation more difficult and hardens the pre-conditioned dumbbells. Continuous exposure of the pre-conditioned dumbbells with US No. 2-D diesel softens it further. The presence of DHT diesel in the Sasol SPD™ diesel reduces its hardening effect on the dumbbells.
[0099] FIG. 7 shows: Percentage change in hardness of nitrile rubber dumbbells, pre-conditioned in US No. 2-D and then further aged in the hydrocarbon composition of the invention and US No. 2-D diesel.
[0100] The hydrocarbon compositions of the invention have a very high consistent quality with an ultra-low sulphur content and a high cetane number. These compositions provide future fuel characteristics in a form that is compatible with current infrastructure and technology.
[0000] Process Scheme
[0101] This process is illustrated in FIG. 8 .
[0102] Synthesis gas can be produced either using reforming 4 of natural gas or gasification 1 of a suitable hydrocarbonaceous feedstock. The first process option results in synthesis gas 10 a and the latter 10 b , two streams possible of being interchangeable and/or manipulated to a required primary composition. This is illustrated by means of the dotted line linking 10 a and 10 b in said FIG. 8 .
[0103] Either synthesis gas or a blend thereof is sent to a HTFT synthesis process 2 , resulting in a mixture of synthetic hydrocarbons and water. This is separated into at least two streams: stream 11 is an olefinic distillate and stream 17 which for illustration groups all non-distillate range hydrocarbons which might undergo further processing not shown in this description. Stream 11 is sent to hydroconversion unit 3 to obtain the DHT diesel 12 along with other by-products 16 not specifically defined in this invention but know to a person skilled in the art.
[0104] In parallel, another portion of either synthesis gas or a blend thereof is sent to a LTFT synthesis process 5 , also resulting in a mixture of synthetic hydrocarbons and water. This is separated into at least two streams. Stream 13 comprises synthetic hydrocarbon species suitable to be hydroconverted in hydroconversion unit 6 to a distillate range Sasol SPD™ diesel 14 and other products that for the purpose of this illustration are lumped as stream 18 . Stream 19 from LTFT unit 5 comprises all synthesis products not sent to the hydroconversion unit 6 . It will be apparent to a person skilled in the art that this product might be further processed beyond the scope of this invention.
[0105] Streams 12 —DHT diesel—and 14 —Sasol SPD™ diesel—can then be blended resulting in the C1 fuel matter of this invention, stream 15 . The blending ratio for the two synthetic fuels might be between 1:100 to 100:1, preferably 1:40 to 40:1, and even more preferably 1:20 to 20:1 on a volume basis.
[0106] Hydroprocessing to obtain the synthetic distillates can be done in parallel units—as described before—or in a single one to optimize the process. In the latter case, illustrated by the dotted line linking streams 11 and 13 in FIG. 8 , the blending ratio for the two synthetic feeds might be between 1:100 to 100:1, preferably 1:40 to 40:1, and even more preferably 1:20 to 20:1 on a volume basis.
[0107] It is noted that while the two FT processes can be operated at separate locations respectively, there might be some significant synergy effects in running them together at the same location. These effects include better utilisation of the synthesis gas and integration of process utilities, as well as those derived from the product blend matter of this invention. | The invention provides a hydrocarbon composition for use in CI engines, said composition comprising a blend of hydrocarbons derived from a LTFT and from a HTFT process, said LTFT derived hydrocarbon being blended with said HTFT derived hydrocarbon in a volumetric ratio of from 1:20 to 20:1. The invention further provides a process for the production of the hydrocarbon composition and a the fuel composition including, in addition to the hydrocarbon composition, one or more component selected from the group including a crude oil derived diesel fuel, a crude oil derived naphtha, a lubricant or light cycle oil (LCO). | 8 |
FIELD OF THE INVENTION
[0001] The invention relates to chemical additives for use in hydraulic fracturing fluids used in oil and natural gas recovery from shale formations.
BACKGROUND OF THE INVENTION
[0002] The intensifying societal quest for more energy, and in particular hydrocarbon based energy, has driven exploration further afield, from deep sea drilling for oil to the search for oil and gas ever deeper in the earth's crust. In recent years, gas entrained in deep shale formations has come very much into focus. The improved technology of gas extraction combined with an increased understanding of the vast extent of gas bearing shale underlying many of the world's continents has given rise to a development rate and scale of almost land rush proportion. Early development is currently most pronounced in the United States. In that regard, North America is blessed with enormous shale deposits that hold the promise of abundant, relatively low cost natural gas supply for a century or longer. There are, however, several difficulties in recovering this gas. The gas is held tightly in the shale deposits at depths of 2 thousand feet and more. Thus, recovery must involve breaking up or hydraulically fracturing the shale to induce release of the gas. Typically, water containing suspended sand, ceramics, clays or other particulates are pumped at high pressure into the shale through vertical and horizontal bore-holes. The particulate material in the fracturing mixture is entrained in the fractured shale and serves to hold open fracture sites facilitating gas release.
[0003] Fracturing fluids also contains a variety of chemicals, often from 3 to more than a dozen, in total up to about 2 percent of the mixture. These chemicals impart certain properties to the fluid, properties critical for oil and gas recovery and optimum well operation. Biocides, clay stabilizers, corrosion inhibitors, crosslinkers, fluid friction reducers, gelling agents, scale inhibitors, surfactants, pH control agents and other materials are among the necessary chemical additives used in fracturing fluids. The chemicals selected for a given fracture fluid are site specific for the type of shale to be fractured. Variations in shale thickness, presence of natural fractures, borehole geometry and site drilling density all play a role in additive choice. Since each gas well requires millions of gallons of fracturing fluid, significant quantities of these water-soluble chemical additives are injected into the shale layers. This leads directly to another major shale fracturing concern: potential chemical contamination of ground water thousands of feet above the shale layers.
[0004] For example, the drilling and hydraulic fracturing of a typical gas well in the Marcellus Shale formation underlying most of western, central and northern Pennsylvania requires nearly 4 million gallons of fracturing fluid. While the exact composition of a fracturing fluid will vary depending on geological conditions of the individual well, it is reasonable to assume that 0.5-2% of the primarily water/sand fracturing suspension is composed of chemical additives. Approximately 60% of the fluid pumped into the well returns up the wellbore once applied pressure is released and this recovery liquid can be reused. This calculates to 14-32 thousand gallons of chemical additives injected into the fractured shale for each and every well drilled, and this is the fraction that would remain in the shale and surrounding strata. The danger of widespread ground water contamination over time caused by slow upward migration of some of these chemicals has the potential to become a genuine environmental catastrophe. Chemical additive leakage from well flowback holding basins is another possible source of ground water contamination. As federal, state and local authorities are now engaged in collecting and analyzing ground water near drilling sites and further afield, evidence is beginning to accumulate suggesting the environmental concerns are real. Low levels of some of these chemical additives have been detected in rivers and streams in those areas of intense drilling activity, although the origin of most of these chemicals remains in controversy. Monitoring studies continue and both the energy companies, the EPA and state environmental authorities remain at work to find ways to recover the needed oil or gas at much lower risk.
[0005] An examination of the chemical additive package indicates that just three components make up about 60% of the total. Hydrochloric acid is typically the largest fraction of the additive mix at about 25%, and it is generally believed that most or all of this dilute acid is neutralized by carbonate rock almost always present to some degree in underlying strata. Thus, no hydrochloric acid is expected to reach ground water and so far there is little evidence that this has occurred. The acid serves to solubilize certain minerals to foster crack initiation in the shale layer, and to some extent clear damage caused by drilling mud in the vicinity of the wellbore. Another important fraction of the additive package is a friction reducer at about 18-20% of the total; these materials are often referred to ‘slickwater’. The friction reducers allow fracturing fluids and proppant (sand) to be pumped to the target zone at higher rates and reduced pressures than if they were not used. Fluid friction reduction is critical to the effective fracturing process. Generally the friction reducer in common use is polyacrylamide. This water-soluble polymer does not easily degrade in the environment and is considered a toxic contaminant when found in ground water. A surfactant, often lauryl sulfate, is the third most predominant component of the additive mix at about 16-17%. Lauryl sulfate serves the dual function of increasing the viscosity of the fracture fluid while preventing emulsion formation. Again, it would be an environmental hazard should this material reach the water table in high concentration.
[0006] Present in lower concentration (˜9-10%) in fracture fluids, and similar to polyacryamide, are copolymers of acrylamide and sodium acrylate used as scale inhibitors. Sodium polyvinylcarboxylate is also used for this function. And again, these materials do not easily degrade and represent biohazards when found in the water table.
[0007] In summary, shale gas and oil recovery is vital to any nation's welfare and that is particularly true for the United States, but recovery must be accomplished in an optimized fracturing process at the lowest possible cost to the environment.
[0000]
Compound*
Purpose
Common application
Acids
Helps dissolve minerals
Swimming pool cleaner
and initiate fissure in rock
(pre-fracture)
Glutaraldehyde
Eliminates bacteria in the
Disinfectant; Sterilizer for
water
medical and dental
equipment
Sodium Chloride
Allows a delayed break
Table salt
down of the gel polymer
chains
N,N-Dimethylformamide
Prevents the corrosion of
Used in pharmaceuticals,
the pipe
acrylic fibers and plastics
Borate salts
Maintains fluid viscosity
Used in laundry
as temperature increases
detergents, hand soaps
and cosmetics
Polyacrylamide
Minimizes friction
Water treatment, soil
between fluid and pipe
conditioner
Petroleum distillates
“Slicks” the water to
Make-up remover,
minimize friction
laxatives, and candy
Guar gum
Thickens the water to
Thickener used in
suspend the sand
cosmetics, baked goods,
ice cream, toothpaste,
sauces, and salad
dressing
Citric Acid
Prevents precipitation of
Food additive; food and
metal oxides
beverages; lemon juice
Potassium chloride
Creates a brine carrier
Low sodium table salt
fluid
substitute
Ammonium bisulfite
Removes oxygen from
Cosmetics, food and
the water to protect the
beverage processing,
pipe from corrosion
water treatment
Sodium or potassium
Maintains the
Washing soda,
carbonate
effectiveness of
detergents, soap, water
other components, such
softener, glass and
as crosslinkers
ceramics
Proppant
Allows the fissures to
Drinking water filtration,
remain open so the gas
play sand
can escape
Ethylene glycol
Prevents scale deposits
Automotive antifreeze,
in the pipe
household cleansers,
deicing, and caulk
Isopropanol
Used to increase the
Glass cleaner,
viscosity of the fracture
antiperspirant, and hair
fluid
color
SUMMARY OF THE INVENTION
[0008] It is therefore the primary object of the invention to render the most dangerous of the chemical additives used in fracturing fluids less harmful to the environment. Another objective of this invention is to transform the fracturing process of gas and oil bearing shale formations into one that uses lower quantities of certain chemical additives, particularly those that might be considered “loose” or migratory in such shale formations.
[0009] Yet another objective of the invention is to allow a more efficient use of these chemicals in the process during subsequent fracturing fluid injections of the same wellbore. These objectives are all accomplished selecting a proppant or other particulate and by binding these additives to these particulate materials in such a manner so that the additives can perform their function as a component in the fracturing fluid during the shale fracturing process, yet present minimal contamination to ground water in contact with human communities and the surface environment. Further, as these bound additives become entrained in the shale strata, the additives are then able to continue to perform their functions during later fluid injections. It is expected that upward chemical additive migration to the water table or surface water bodies would be eliminated or significantly retarded using the technology of this invention. It is further anticipated that these additive bound particulates will perform the function of shale release far more efficiently. Particulate-bound chemical additives of course may be easily filtered should these be found in flowback holding basins thus ensuring no leakage into the environment.
[0010] Attaching the water-soluble chemical additives, such polyacrylamide, to water insoluble particulate materials ensures that additives are entrained or captured in or near the fractured shale strata. This capturing mechanism actually tends to increase the concentration of certain additives in regions where they are required for efficient gas release. The captured chemical additives continues to perform their function in the fracturing process but are prevented from migration and possible contamination of surface water. Many kinds of particulate minerals may be used in this invention but those most preferred include silica, quartz, clays and metal oxides such as alumina and titanium dioxide. Clays generally arise from four major classes: kaolinite, illite, chlorite, and/or montmorillonite-smectite, including but not limited to: ripidolite, rectorite, bentonite, ferriginous-smectite, vermiculite, saponite, sepiolite, cookeite, beidellite, nontronite, barasym, and corrensite. Many polymers and copolymers useful as chemical additives in gas-bearing shale fracturing fluids may also be attached to particulate materials. These would include but not be limited to any polymers derived from vinyl based monomers, for example, acrylic acid and methacrylic acid and, for example, their salts of alkali metals and alkaline earth metals, acrylamide, methacrylamide, mono- and dialkyl(meth)acrylamides. In fact, almost any monomer capable of free radical polymerization is compatible and useful for the technology of this invention.
[0011] A broad variety of surfactants may also be attached to particulate materials of this invention. For example, these include but are limited to polymers derived from ethylene oxide, vinyl monomers of organic carboxylic acids, organic sulfonic acids, and their salts of alkali metals and alkaline earth metals. Also, for example, metal organic sulfonates and sarcosinates are particularly useful. The surfactant materials such as the organic sulfonates may be bound to particles themselves or in combination with the water soluble chemical additives such as polyacrylamide or polyacrylic acid.
[0012] In many instances, reversible addition fragmentation techniques (RAFT) and atom transfer radical polymerization (ATRP) polymerization procedures have been found to be most effective in preparing the particulate bonded chemical additives of this invention.
[0013] Further, by tailoring the structure of polymers and surfactants, many the functions of small molecules used in fracturing fluids may be developed in particulate bonded moieties. Thus, the useful properties of small molecule chemical additives may be captured in particulate bonded additives with desirable very low migration rates or these moieties. Laboratory experimental evidence presented here indicates that in some instances these particulate bonded chemicals may be completely and permanently entrained in the shale strata or adjacent strata.
[0014] The following table shows chemical additives used in hydraulic fracturing fluids, particularly some of the types of chemicals currently used in oil and gas shale fracturing fluids and the function each material performs.
[0000]
Chemical Name
Chemical Purpose
Product Function
Hydrochloric acid
Dissolves minerals and initiates cracks
acid
in the rock
Quaternary ammonium
Controls aqueous bacteria that
biocide
chloride
produce corrosive by-products
Tetrakis-
Controls aqueous bacteria that
biocide
hydroxymethylphosphonium
produce corrosive by-products
sulfate
Ammonium persulfate
Allows a delayed breakdown of the gel
breaker
Calcium chloride
Allows a delayed breakdown of the gel
breaker
Choline chloride
Prevents clay from swelling or shifting
clay stabilizer
Tetramethyl ammonium
Prevents clay from swelling or shifting
clay stabilizer
chloride
Methanol
Product stabilizer and/or winterizing
corrosion
agent
inhibitor
Formic acid, N,N-
Prevents pipe corrosion
corrosion
dimethylformamide
inhibitor
Petroleum distillate
Carrier fluid for borate, zirconate
crosslinker
crosslinker, polyacrylamide and Guar
gum
Borate and/or zirconium
Maintains fluid viscosity as
crosslinker
complex
temperature increases
Polyacrylamide
“slicks” the water to minimize friction
friction reducer
Polysaccharide blend (e.g.,
Thickens water to suspend sand
gelling agent
Guar gum)
Ethylene glycol
Product stabilizer and winterizing
gelling agent
agent
Citric acid, acetic acid,
Prevents precipitation of metal oxides
iron control
thioglycolic acid, sodium
erythrorbate
Lauryl sulfate, isopropanol,
Prevent emulsion formation in the
non-emulsifier
ethylene glycol
fracture fluid
Sodium/potassium
Adjusts the pH of fluid to maintain
pH adjusting
hydroxide,
effectiveness of other components
agent
sodium/potassium
such as crosslinkers
carbonate
Copolymer of acrylamide
Prevents scale deposits in pipe
scale inhibitor
and sodium acrylate
Sodium polyacrylate
Prevents scale deposits in pipe
scale inhibitor
Phosphoric acid salts
Prevents scale deposits in pipe
scale inhibitor
Lauryl sulfate
Used here to increase the viscosity of
surfactant
the fracture fluid
naphthalene
Carrier fluid for surfactants
surfactant
support
Ethanol, methanol,
Product stabilizer and/or winterizing
surfactant
isopropanol
gent
support
2-butoxyethanol
Product stabilizer
Surfactant
support
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings constitute a part of the Specification and serve to assist in further characterizing certain embodiments of the invention.
[0016] FIG. 1 is a representative UV analysis calibration curve useful to calculate grafting densities of RAFT agents to silica particles as described hereafter.
[0017] FIG. 2 is a representative UV analysis calibration curve useful to determine the concentration of RAFT agents on silica particles as described hereafter.
[0018] FIG. 3 is a representative UV analysis absorbance curve useful to determine the graft density on silica particles as described hereafter.
DETAILED DESCRIPTION
[0019] Reference now will be made to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of an explanation of the invention, not as a limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as one embodiment can be used on another embodiment to yield still a further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied exemplary constructions.
[0020] Generally speaking, the present disclosure is directed to the composition, preparation and application of chemical additives for shale gas fracturing fluid market through the versatile and widely applicable methods of attaching chains to particles via grafting-to or grafting-from or grafting through methods. An example of the grafting-from processes is through polymerization from the particle surface (e.g., RAFT polymerization) to synthesize particles with multiple polymeric assemblies. In this technique, consecutive step-by-step polymerizations (e.g., utilizing RAFT polymerization) can be used to prepare particles with multiple polymeric assemblies. In another version of this technique, RAFT polymerization followed by ATRP polymerization can be used to synthesize particles with multiple polymeric assemblies. In the grafting-to technique, polymerization techniques can be used to initially prepare polymers with binding functionalities, and then the preformed polymer can be subsequently attached to the particle surfaces. In the grafting-through technique, polymerization techniques can be used to prepare polymers which react with a reactive functionality on the surface of the particles during the polymerization.
[0021] Through these methods, particulate materials can be functionalized with multiple polymeric assemblies. In particular each particle can have one or more different polymeric chains extending therefrom. In certain embodiments, the particles with multiple polymeric assemblies can be formed while maintaining simultaneous control over multiple variables, including but not limited to monomer-type, grafted chain molecular weight, polydispersity, etc. The grafted polymer chains, which are covalently attached to the particle surface, can perform the same function in a fracturing fluid as that polymer not bonded to particulate materials.
[0022] In one embodiment, two different types of polymeric assemblies (e.g., a first polymeric chain and a second polymeric chain) can be attached to a particle. In other embodiments, a third type of polymeric assembly (i.e., a third polymeric chain) can also be attached. Additional polymeric assemblies (e.g., a fourth polymeric chain) can also be attached to the surface, depending on the available surface area on the particles and/or the size, dispersity, and/or density of the first, second, and third polymeric chains already present on the surface of the particle.
[0023] A preferred embodiment is the attachment of any of the following or combinations of the following to silica particles: polyacrylic acid, polyacrylic acid copolymers, sodium or potassium salts of polyacrylic acid and its copolymers, polyacrylamide and polyacrylamide copolymers. Surfactants such as lauryl sulfate may also be attached to the same particles.
[0000] Preparation of Particulate Materials with One or More Polymeric Assemblies
1. Particulate Materials:
[0024] The presently disclosed methods can be utilized on a variety of different types of particles. The particles may comprise for example natural or synthetic clays (including those made from amorphous or structured clays), inorganic metal oxides (e.g., silica, alumina, and the like), latexes, etc. Particularly suitable particulate materials include inorganic materials such as silica, alumina, titania (TiO 2 ), indium tin oxide (ITO), CdSe, etc., or mixtures thereof. Organic particulate materials suitable for use include polymeric particles, carbon, graphite, graphene, etc., or mixtures thereof.
[0025] Particulates as used herein means particles (including but not limited to rod-shaped particles, spherical-shaped particles, disc-shaped particles, platelet-shaped particles, tetrahedral-shaped particles), fibers, or similarly shaped materials. In one embodiment, the particulates have an average particle size of about 0.01 micron to about 2 millimeters, preferably 10 microns to about 1 mm. That is, the particles have a dimension (e.g., a diameter or length) of about 0.01 micron to 2 mm. A specific particle size distribution (PSD) is selected depending on known morphologies of the underlying shale.
[0026] The particles may be crystalline or amorphous. A single type of particulate material may be used, or mixtures of different types of particulates may be used. If a mixture of particles is used they may be homogeneously or non-homogeneously distributed in the fracturing fluid composition. Non-limiting examples of suitable particle size distributions of particles are those within the range of less than about 1 mm, alternatively less than about 0.1 mm, and alternatively less than about 0.01 mm.
[0027] It should also be understood that certain particle size distributions may be useful to provide certain benefits, and other ranges of particle size distributions may be useful to provide other benefits (for instance, ‘slickwater’ property enhancement in a given fracturing fluid composition may require a different particle size range than the other properties desired). The average particle size of a batch of particles may differ from the particle size distribution of those particles. For example, a layered synthetic silicate can have an average particle size of about 25 nanometers while its particle size distribution can generally vary between about 10 nm to about 40 nm.
[0028] In one embodiment, the particles can be exfoliated from a starting material to form the particles of varying particle size depending on the defoliation process. Such starting material may have an average size of up to about 50 microns. In another embodiment, the particles can be grown to the desired average particle size. Various lots of known average particle size can be blended to prepare particulate with a desired PSD.
2. Attaching a First Anchoring Compound to the Particulate Material:
[0029] In certain embodiments, a first anchoring compound can be attached to the surface of the particle for subsequent attachment of the first polymeric chains (e.g., via a “grafting-from” or “grafting-to” approach, as described in greater detail below). The first anchoring compound is covalently bonded to the surface of the particle, either directly or via a first functionalization group. The given anchor compound can be selected based upon the type of particle and/or the type of polymeric chain to be attached thereto.
[0030] The first anchoring compound has a functional group for further reaction. Suitable functional groups for further reaction can include, but are not limited to, amine groups (e.g., amide groups, azide groups, cyanate groups; nitrate groups, nitrite groups, etc.), thiol groups (e.g., sulfinic acid, sulfonic acid, thiocyanates, etc.), phosphonate groups, hydroxyl groups (e.g., —OH), carboxylic acid groups (e.g., —COOH), aldehyde groups (e.g., —CHO), halogen groups (e.g., haloalkanes, haloformyls, etc.), epoxy groups, alkenes, alkynes, and the like. For example, the anchoring compound can be a RAFT agent, when used with a grafting-from polymerization technique. For example, in one particular embodiment, 4-cyanopentanoic acid dithiobenzoate (CPDB) can be attached to the surface of the particle as a first anchor. In this embodiment, the dithioester anchoring compound can be immobilized onto the surface of the particles (e.g., colloidal silica particles). For instance, the 4-cyanopentanoic acid dithiobenzoate anchoring compound can be attached on the surface of the particles by first functionalizing the surface of the particles with amine groups using 3-aminopropyldimethylethoxysilane. Use of a mono-functional silane such as 3-aminopropyldimethylethoxysilane compared to a trifunctional silane ensures the formation of a monolayer of initiator on the silica surface and prevents particle agglomeration by crosslinking during processing. The ratio of the 3-aminopropyldimethylethoxysilane to silica particles is critical in determining the grafting density. In addition to adjusting the ratio by varying the concentration of amino-silane, addition of a small amount of an inert dimethylmethoxy-n-octylsilane helps to partially cover the silica surface by inert alkyl groups and helps to tune the grafting density along with preventing aggregation of the particles. To attach the anchoring compound onto the amine functional silica, the 4-cyanopentanioc acid dithiobenzoate can be first activated by using 2-mercaptothiazoline. It can then immobilized onto the surface of silica via a condensation reaction with the amine groups on the silica surface. Using this approach, various CPDB-functionalized particles can be synthesized having a grafting density varying from 0.01-0.7 anchoring compounds/nm 2 . An inherent advantage of this technique compared to the other “grafting-from” methods is the ease and accuracy in measuring the grafting density before carrying out the polymerization. The CPDB molecule is UV-VIS active and hence by comparing the absorption at 302 nm from the CPDB-functionalized particles to a standard absorption curve made from known amounts of free CPDB, the concentration of the anchoring compounds attached onto the particles can be calculated. Knowledge of the concentration of the anchoring compounds attached onto the particles before the reaction provides the reaction with control and predictability, which is the key to controlling molecular weight and molecular weight distribution should those factors prove important for the efficacy of a given fracturing fluid composition.
3. Attaching a First Polymeric Chain to the First Anchoring Compound:
[0031] Two methods can be utilized to form the first polymeric chain extending from the particles via the first anchoring compound: a “grafting-from” approach and a “grafting-to” approach. These strategies will be explained in more details in the following sections.
[0032] A. “Grafting-From” Methods
[0033] In one embodiment, the first polymeric chain can be formed by polymerizing a first plurality of first monomers on the first anchoring compound, resulting in the first polymeric chain being covalently bonded to the particle via the first anchoring compound. According to this method, the polymerization of the first polymeric chain can be conducted through any suitable type of polymerization, such as RAFT polymerization, ATRP, etc., which are discussed in greater detail below. The particular types of monomer(s) and/or polymerization technique can be selected based upon the desired polymeric chain to be formed. For example, for RAFT polymerization, monomers containing acrylate, methacrylate groups, acrylamides, styrenics, etc., are particularly suitable for formation of the first polymeric chain. Thus, the “grafting-from” method involves formation of the first polymeric chain onto the first anchoring compound and results in the first polymeric chain being covalently bonded to the particle via the first anchoring compound (and, if present, a first functionalization compound).
[0034] B. “Grafting-To” Methods
[0035] In one embodiment, the first polymeric chain can be first polymerized and subsequently covalently bonded to the surface of the particle, either directly or via a first anchoring compound (and, if present, a first functionalization compound). Thus, in this embodiment, the first polymeric chain has been polymerized prior to attachment to the first anchoring compound. In this embodiment, the first polymeric chain is not limited to the type of polymerization and/or types of monomer(s) capable of being polymerized directly to the first anchoring compound. As such, as long as the first polymeric chain defines a functional group that can react and bond to the first anchoring compound, any polymeric chain can be bonded to the particle.
[0036] C. “Grafting Through” Methods
[0037] In another embodiment, a polymerizable monomer bound directly on the surface of the particle is used to initiate the polymerization of many monomers or mixture of monomers, resulting in the attachment of polymer chains to the particle surface. In such polymerization reaction, the surface-attached monomers are incorporated into the growing polymer chains in a “grafting-through” manner, where the polymers are eventually bound to the surface of the particle. According to this method, the polymerization of the first polymeric chain can be conducted through any suitable type of polymerization, such as RAFT polymerization, ATRP, etc. Thus in this embodiment the macromonomer is essentially the functionalized particle.
4. Deactivating the First Polymeric Chain:
[0038] No matter the method used to attach the first polymeric chain to first anchoring compound on the particle, upon attachment, the first polymeric chain can be deactivated to prevent further polymerization thereon. For example, if the “grafting-from” method was utilized to attach the first polymeric chain to the first anchoring compound via polymerization through a controlled living polymerization (CLP) technique (e.g., RAFT), a deactivation agent can be attached to the end of each polymeric chain to inhibit further polymerization thereon. The deactivation agents can be selected based upon the type of polymerization and/or the type(s) of monomers utilized, but can generally include but are not limited to amines, peroxides, or mixtures thereof. On the other hand, if the “grafting-to” method was utilized to attach the first polymeric chain to the first anchoring compound via attaching a pre-formed first polymeric chain, the first polymeric chain can be deactivated after covalently bonding the first polymeric chain to the first anchoring compound and prior to attaching the second anchoring compound to the particle. Alternatively, the first polymeric chain can be deactivated prior to covalently bonding the first polymeric chain to the first anchoring compound.
5. Attaching a Second Anchoring Compound to the Particulate Material:
[0039] After attachment and deactivation of the first polymeric chain to the particle, a second anchoring compound can be attached to the remaining surface defined on the particle. This second anchoring compound can be attached via any of the methods described above with respect to the first anchoring compound. The second anchoring compound and/or method of its attachment need not be the same as the first anchoring compound. However, in one particular embodiment, the first anchoring compound and the second anchoring compound are the same.
[0000] 6. Formation of a Second Polymeric Chain Extending from the Particulate Material:
[0040] The second polymeric chain can be attached to the second anchoring compound on the particle via the “grafting-from” method described above with respect to the first polymeric chain. The type(s) of monomers and/or polymerization technique for the formation of the second polymeric chain can be selected independently of the type of first polymeric chain already present on the particle. However, without wishing to be bound by any particular theory, it is presently believed that the use of a “grafting-to” method, which would utilize a pre-formed second polymeric chain, may not be suitable due to the limited access of such a pre-formed polymeric chain to the second anchoring agent on the surface of the particle between the first polymeric chains.
7. Additional Polymeric Chains
[0041] Additional polymeric chains (e.g., a third polymeric chain, fourth polymeric chain, etc.) can be attached to the particle as desired following the description above with respect to the attachment of the second polymeric chain.
[0000] 8. Particulate Materials with Multiple Polymeric Assemblies:
[0042] According to these methods, particles with multiple polymeric assemblies can be formed that have a first polymeric chain covalently bonded to its surface via a first anchoring compound and a second polymeric chain covalently bonded to its surface via a second anchoring compound. As stated, additional polymeric chains (e.g., a third polymeric chain) can be further attached to the particles.
[0043] As used herein, the term “first polymeric chain” is meant to describe a first type of polymeric chain, and one of ordinary skill in the art would recognize that a multiple first polymeric chains could be present on the particle (i.e., a first plurality of first polymeric chains). Likewise, the term “second polymeric chain” is meant to describe a second type of polymeric chain, and one of ordinary skill in the art would recognize that a multiple second polymeric chains could be present on the particle (i.e., a second plurality of second polymeric chains). Even further, the term “third polymeric chain” is meant to describe a third type of polymeric chain, and one of ordinary skill in the art would recognize that a multiple third polymeric chains could be present on the particle (i.e., a third plurality of third polymeric chains).
[0044] As stated, the first polymeric chain can be different than the second polymeric chain (e.g., the polymeric first polymeric chain can have a different polydispersity index, molecular weight, etc. than the second polymeric chain). For instance, in one embodiment, the first polymeric chain can have a molecular weight up to 50,000 g/mol (e.g., up to 25,000, up to 10,000, or about 500 to about 50,000 g/mol), and the second polymeric chain can have a molecular weight of about 50,000 g/mol or more. The use of such a relatively small molecular weight for the first polymeric chain can help ensure access to the remaining surface defined on the particle for attachment of the second anchoring compound.
[0045] In one embodiment, more first polymeric chains can be attached to the surface of the particle than second polymeric chains.
[0046] In another embodiment, a polymerization initiator can be placed on the surface of the particle and used to initiate the polymerization of many monomers or mixture of monomers, resulting in the attachment of polymer chains to the particle surface. Initiators such as peroxides, azo containing compounds, peracetates, photoinitiators and many others known to those skilled in the art can be prepared with one or more functional groups which are capable of reacting with the silica particle surface. Such functional groups include carboxylic acid, silane coupling groups, phosphate groups, and phosphonate groups. The functional groups are reacted with the silica particle surface to attach the initiator to the surface and then added to the polymerization mixture during the polymerization of the monomers. The initiators, already bound to the surface of the particles then initiate chain growth of the monomers. Conventional chain growth polymerization, controlled radical polymerizations, and photochemical initiated polymerizations may be carried out with the initiator-bound particles resulting in the attachment of the polymer chains to the particles.
Polymerization Techniques
[0047] As stated, the first and second polymeric chains can be formed via controlled polymerizations, such as controlled living polymerizations or controlled ring-opening polymerizations, which may be independently selected for each of the first and second polymeric chains based upon the particular anchoring agent present on the particle, type of monomer(s) used to form the polymeric chain, and/or desired properties of the polymeric chains formed. Through the use of these controlled polymerizations, each polymeric chain can be produced with low polydispersity and diverse architectures. Thus, these methods are ideal for block polymer and/or graft polymer synthesis.
[0048] Controlled living polymerization generally refers to chain growth polymerization that proceeds with significantly suppressed termination or chain transfer steps. Thus, polymerization in CLP proceeds until all monomer units have been consumed or until the reaction is terminated (e.g., through quenching and/or deactivating), and the addition of monomer results in continued polymerization, making CLP ideal for block polymer and graft polymer synthesis. The molecular weight of the resulting polymer is generally a linear function of conversion so that the polymeric chains are initiated and grow substantially uniformly. Thus, CLPs provide precise control on molecular structures, functionality and compositions. Thus, these polymers can be tuned with desirable compositions and architectures most suitable for optimum performance of the shale hydraulic fracturing fluid.
[0049] Controlled living polymerizations can be used to produce block copolymers because CLP can leave a functional terminal group on the polymer formed (e.g., a halogen functional group). For example, in the copolymerization of two monomers (A and B) allowing A to polymerize via CLP will exhaust the monomer in solution with minimal termination. After monomer A is fully reacted, the addition of monomer B will result in a block copolymer. Controlled ring-opening polymerizations can utilize suitable catalysts such as tin-derived catalysts to open the rings of monomers to form a polymer. Several of such polymerization techniques are discussed in this application. These techniques are generally known to those skilled in the art. A brief general description of each technique is below, and is provided for further understanding of the present invention, and is not intended to be limiting:
[0050] A. Reversible Addition-Fragmentation Chain Transfer Polymerization
[0051] Reversible Addition-Fragmentation chain Transfer polymerization is one type of controlled radical polymerization. RAFT polymerization uses thiocarbonylthio compounds, such as dithioesters, dithiocarbamates, trithiocarbonates, and xanthates, in order to mediate the polymerization via a reversible chain-transfer process. RAFT polymerization can be performed by simply adding a chosen quantity of appropriate RAFT agents (thiocarbonylthio compounds) to a conventional free radical polymerization. RAFT polymerization is particularly useful with monomers having a vinyl functional group (e.g., a (meth)acrylate group). Typically, a RAFT polymerization system includes the monomer, an initiator, and a RAFT agent (also referred to as a chain transfer agent). Because of the low concentration of the RAFT agent in the system, the concentration of the initiator is usually lower than in conventional radical polymerization. Suitable radical initiators can be azobisisobutyronitrile (AIBN), 4,4′-azobis(4-cyanovaleric acid) (ACVA), etc. RAFT agents are generally thiocarbonylthio compounds, such as generally shown below:
[0000]
[0000] where the Z group primarily stabilizes radical species added to the C═S bond and the R group is a good homolytic leaving group which is able to initiate monomers. For example, the Z group can be an aryl group (e.g., phenyl group, benzyl group, etc.), an alkyl group, an alkoxy group, a substituted amine group, etc.
[0052] As stated, RAFT is a type of living polymerization involving a conventional radical polymerization in the presence of a reversible chain transfer reagent. Like other living radical polymerizations, there is minimized termination step in the RAFT process. The reaction is started by radical initiators (e.g., AIBN or peroxides). In this initiation step, the initiator reacts with a monomer unit to create a radical species that starts an active polymerizing chain. Then, the active chain reacts with the thiocarbonylthio compound, which ejects the homolytic leaving group (R). This is a reversible step, with an intermediate species capable of losing either the leaving group (R) or the active species. The leaving group radical then reacts with another monomer species, starting another active polymer chain. This active chain is then able to go through the addition-fragmentation or equilibration steps. The equilibration keeps the majority of the active propagating species into the dormant thiocarbonyl compound, limiting the possibility of chain termination. Thus, active polymer chains are in equilibrium between the active and dormant species. While one polymer chain is in the dormant stage (bound to the thiocarbonyl compound), the other is active in polymerization. By controlling the concentration of initiator and thiocarbonylthio compound and/or the ratio of monomer to thiocarbonylthio compound, the molecular weight of the polymeric chains can be controlled with low polydispersities.
[0053] Depending on the target molecular weight of final polymers, the monomer to RAFT agent ratios can range from about less than about 10 to more than about 10,000 (e.g., about 10 to about 5,000). Other reaction parameters can be varied to control the molecular weight of the final polymers, such as solvent selection, reaction temperature, and reaction time. For instance, solvents can include conventional organic solvents such as tetrahydrofuran, toluene, dimethylformamide, anisole, acetonitrile, dichloromethane, aqueous media, etc. The reaction temperature can range from room temperature (e.g., about 20° C.) to about 120° C. The reaction time can be from less than about 1 h to about 72 h. The RAFT process allows the synthesis of polymers with specific macromolecular architectures such as block, gradient, statistical, comb/brush, star, hyperbranched, and network copolymers although the simplest structures will likely suffice for application in a shale fracturing fluid.
[0054] Nevertheless, because RAFT polymerization is a form of living radical polymerization, it is ideal for synthesis of block copolymers. For example, in the copolymerization of two monomers (A and B), allowing A to polymerize via RAFT will exhaust the monomer in solution with significantly suppressed termination. After monomer A is fully reacted, the addition of monomer B will result in a block copolymer. One requirement for maintaining a narrow polydispersity in this type of copolymer is to have a chain transfer agent with a high transfer constant to the subsequent monomer (monomer B in the example). Using a multifuntional RAFT agent can result in the formation of a star copolymer. RAFT differs from other forms of CLPs because the core of the copolymer can be introduced by functionalization of either the R group or the Z group. While utilizing the R group results in similar structures found using ATRP or NMP, the use of the Z group makes RAFT unique. When the Z group is used, the reactive polymeric arms are detached from the core while they grow and react back into the core for the chain-transfer reaction.
[0055] B. Atom Transfer Radical Polymerization
[0056] Atom transfer radical polymerization (ATRP) is another example of a living radical polymerization. The control is achieved through an activation-deactivation process, in which most of the reaction species are in dormant format, thus significantly reducing chain termination reaction. The four major components of ATRP include the monomer, initiator, ligand, and catalyst. ATRP is particularly useful monomers having a vinyl functional group (e.g., a (meth)acrylate group). Organic halides are particularly suitable initiators, such as alkyl halides (e.g., alkyl bromides, alkyl chlorides, etc.). For instance, in one particular embodiment, the alkyl halide can be ethyl 2-bromoisobutyrate. The shape or structure of the initiator can also determine the architecture of the resulting polymer. For example, initiators with multiple alkyl halide groups on a single core can lead to a star-like polymer shape.
[0057] The catalyst can determine the equilibrium constant between the active and dormant species during polymerization, leading to control of the polymerization rate and the equilibrium constant. In one particular embodiment, the catalyst is a metal having two accessible oxidation states that are separated by one electron, and a reasonable affinity for halogens. One particularly suitable metal catalyst for ATRP is copper (I). The ligands can be linear amines or pyridine-based amines.
[0058] Depending on the target molecular weight of final polymers, the monomer to initiator ratios can range from less than about 10 to more than about 1,000 (e.g., about 10 to about 1,000). Other reaction parameters can be varied to control the molecular weight of the final polymers, such as solvent selection, reaction temperature, and reaction time. For instance, solvents can include conventional organic solvents such as tetrahydrofuran, toluene, dimethylformamide, anisole, acetonitrile, dichloromethane, etc. The reaction temperature can range from room temperature (e.g., about 20° C.) to about 12° C. The reaction time can be from less than about 1 h to about 48 h.
[0059] C. Nitroxide-Mediated Polymerization
[0060] Nitroxide-mediated polymerization (NMP) is another form of controlled living polymerization utilizing a nitroxide radical, such as shown below:
[0000]
[0000] where R1 and R2 are, independently, organic groups (e.g., aryl groups such as phenyl groups, benzyl groups, etc.; alkyl groups, etc.). NMP is particularly useful with monomers having a vinyl functional group (e.g., a (meth)acrylate group).
[0061] D. Ring-Opening Metathesis Polymerization
[0062] Ring-opening metathesis polymerization (ROMP) is a type of olefin metathesis polymerization. The driving force of the reaction is relief of ring strain in cyclic olefins (e.g. norbornene or cyclopentene) in the presence of a catalyst. The catalysts used in a ROMP reaction can include a wide variety of metals and range from a simple RuCl 3 /alcohol mixture to Grubbs' catalyst. In this embodiment, the monomer can include a strained ring functional group, such as a norbornene functional group, a cyclopentene functional group, etc. to form the polymeric chains. For example, norbornene is a bridged cyclic hydrocarbon that has a cyclohexene ring bridged with a methylene group in the para position.
[0063] The ROMP catalytic cycle generally requires a strained cyclic structure because the driving force of the reaction is relief of ring strain. After formation of the metal-carbene species, the carbene attacks the double bond in the ring structure forming a highly strained metallacyclobutane intermediate. The ring then opens giving the beginning of the polymer: a linear chain double bonded to the metal with a terminal double bond as well. The new carbene reacts with the double bond on the next monomer, thus propagating the reaction.
[0064] E. Ring-Opening Polymerization
[0065] In one particular embodiment, where the monomer includes a strained ring function group (e.g., a caprolactone or lactide), ring-opening polymerization (ROP) may be used to form the polymeric chain. For example, a caprolcatone-substituted monomer is a polymerizable ester, which can undergo polymerization with the aid of an alcohol as an initiator and a tin-based reagent as a catalyst.
EXAMPLES
1. Synthesis of CPDB Anchored Silica Particles
[0066] A solution (10 ml) of colloidal silica particles (30 wt % in MIBK, Nissan Chemical, 15 nm diameter) was added to a two necked round-bottom flask and diluted with 75 ml of THF. To it was added 3-aminopropyldimethylethoxysilane (0.16 ml, 1 mmol) and the mixture was refluxed at 75° C. overnight under nitrogen protection. The reaction was then cooled to room temperature and precipitated in large amount of hexanes. The particles were then recovered by centrifugation and dispersed in THF using sonication and precipitated in hexanes again. The amino functionalized particles were then dispersed in 40 ml of THF for further reaction.
[0067] A THF solution of the amino functionalized silica particles (40 ml, 1.8 g) was added drop wise to a THF solution (30 ml) of activated CPDB (0.25 g, 0.65 mmol) at room temperature. After complete addition, the solution was stirred overnight. The reaction mixture was then precipitated into a large amount of 4:1 mixture of cyclohexane and ethyl ether (2500 ml). The particles were recovered by centrifugation at 3000 rpm for 8 minutes. The particles were then re-dispersed in 30 ml THF and precipitated in 4:1 mixture of cyclohexane and ethyl ether. This dissolution-precipitation procedure was repeated 2 more times until the supernatant layer after centrifugation was colorless. The red CPDB anchored silica particles were dried at room temperature and analyzed using UV analysis for the chain density. Several such CPDB anchored silica particles having different grafting density from 0.05 to 0.6 chains/nm 2 were prepared by adjusting the ratio of the 3-aminopropyldimethylethoxysilane to colloidal silica particles.
2. Synthesis of Bimodal Silica Grafted Polymethylmethacrylate (PMMA) Particles by Step-by-Step RAFT Polymerization
[0068] A. Graft Polymerization of Methyl Methacrylate Monomer from CPDB Anchored Colloidal Silica Particles to Graft 1 st Chain from Surface of Particles
[0069] A solution of methyl methacrylate (7 mL), CPDB anchored silica particles (300 mg, 80 μmol/g), AIBN (2.40 μmol), and THF (7 mL) was prepared in a dried Schlenk tube. The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath at 60° C. for 3 h. The polymerization solution was quenched in ice water and poured into cold methanol to precipitate polymer grafted silica particles. The polymer chains were cleaved by treating a small amount of particles with HF and the resulting polymer chains were analyzed by GPC. The polymer cleaved from the Si-g-PMMA particles had a molecular weight of 24,400 g/mol and PDI of 1.07.
[0070] B. Cleavage of RAFT Agent from 1 st Brush:
[0071] Solid AIBN (24 μmol) was added to a solution of Si-g-PMMA in THF (0.4 g in 20 ml) and heated at 65° C. under nitrogen for 30 minutes. The resulting white solution mixture was poured into 100 ml hexanes and centrifuged at 8000 rpm for 5 minutes to recover Si-g-PMMA particles.
[0072] C. Functionalization of Si-g-PMMA by 2 nd RAFT Agent:
[0073] The second RAFT agent was attached onto the surface of the silica which was not covered by the first polymer chain. The remaining bare surface of the particles was functionalized by amine groups using 0.01 ml of 3-aminopropyldimethylethoxysilane in a process similar to the first RAFT agent attachment. The second RAFT agent was attached by reaction of 30 mg of activated CPDB (0.030 g) at room temperature with the amino-functional particles.
[0074] D. Graft Polymerization of Methyl Methacrylate from Si-g-PMMA to Synthesize 2 nd Brush:
[0075] The CPDB anchored Si-g-PMMA particles (0.4 g) dissolved in 10 mL THF were added to a dried Schlenk tube along with 15 ml MMA and AIBN (45 μl of 0.005M THF solution). The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath at 65° C. for 12 hours. The polymerization was quenched in ice water. The polymer was recovered by precipitating into hexane and centrifugation at 8000 rpm. GPC results indicated the 2 nd chain has a molecular weight of 103,000 g/mol and PDI of 1.13.
3. Synthesis of Bimodal Silica Grafted Polystyrene (PS) Particles by Step-by-Step RAFT Polymerization
[0076] A. Graft Polymerization of Styrene from CPDB Anchored Colloidal Silica Particles to Graft 1 st Chain from Surface of Particles:
[0077] A solution of styrene (25 ml), CPDB anchored silica particles (1.4 g, 80 μmol/g), AIBN (1.8 ml, 5 mM solution in THF), and THF (25 ml) was prepared in a dried Schlenk tube. The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath at 65° C. for 4 hours. The polymerization solution was quenched in ice water and poured into cold methanol to precipitate polymer grafted silica particles. The polymer chains were cleaved by treating a small amount of particles with HF and the resulting polymer chains were analyzed by GPC. The polymer cleaved from the Si-g-PS particles had a molecular weight of 1600 g/mol and PDI of 1.26.
[0078] B. Cleavage of RAFT Agent from 1 st Brush:
[0079] Solid AIBN (250 mg) was added to a solution of Si-g-PS in THF (2g in 50 ml) and heated at 65° C. under nitrogen for 30 minutes. The resulting white solution mixture was poured into 200 ml hexanes and centrifuged at 8000 rpm for 5 minutes to recover Si-g-PS particles.
[0080] C. Functionalization of Si-g-PS by 2 nd RAFT Agent:
[0081] The second RAFT agent was attached onto the surface of the silica which was not covered by the first polymer chain. The bare surface of the particles was functionalized by amine groups using 0.01 ml of 3-aminopropyldimethylethoxysilane in a process similar to the first RAFT agent attachment. The second RAFT agent was attached by reaction 30 mg of activated CPDB (0.030 g) at room temperature with the amino-functional particles.
[0082] D. Graft Polymerization of Styrene from Si-g-PS to Synthesize 2 nd Brush:
[0083] The CPDB anchored Si-g-PS particles (1.4 g by weight of bare silica) dissolved in 10 ml THF were added to a dried Schlenk tube along with 20 ml styrene and AIBN (1.8 mL of 0.005M THF solution). The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath at 65° C. for 18 hours. The polymerization was quenched in ice water. The polymer was recovered by precipitating into hexane and centrifugation at 8000 rpm. GPC results indicated the 2 nd chain has a molecular weight of 40,000 g/mol and PDI of 1.19.
4. Synthesis of Mixed Brush of Polystyrene and Polymethylmethacrylate (PMMA) Grafted Silica Particles by Step-by-Step RAFT Polymerization
[0084] A. Graft Polymerization of Styrene from CPDB Anchored Colloidal Silica Particles to Graft 1 st Chain from Surface of Particles:
[0085] A solution of styrene (10 ml), CPDB anchored silica particles (0.5 g, 80 μmol/g), AIBN (0.600 ml, 5 mM solution in THF), and THF (10 ml) was prepared in a dried Schlenk tube. The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath at 65° C. for 4 hours. The polymerization solution was quenched in ice water and poured into cold methanol to precipitate polymer grafted silica particles. The polymer chains were cleaved by treating a small amount of particles with HF and the resulting polymer chains were analyzed by GPC. The polymer cleaved from the Si-g-PS particles had a molecular weight of 5000 g/mol and PDI of 1.13.
[0086] B. Cleavage of RAFT Agent from 1 st Brush:
[0087] Solid AIBN (108 mg) was added to a solution of Si-g-PS in THF (0.5 g in 50 ml) and heated at 65° C. under nitrogen for 30 minutes. The resulting white solution mixture was poured into 200 ml hexanes and centrifuged at 8000 rpm for 5 minutes to recover Si-g-PS particles.
[0088] C. Functionalization of Si-g-PS by 2 nd RAFT Agent:
[0089] The second RAFT agent was attached onto the surface of the silica which was not covered by the first polymer chain. The bare surface of the particles was functionalized by amine groups using 0.0025 ml of 3-aminopropyldimethylethoxysilane in a process similar to the first RAFT agent attachment. The second RAFT agent was attached by reaction 30 mg of activated CPDB (0.030 g) at room temperature with the amino-functional particles.
[0090] D. Graft Polymerization of Methyl Methacrylate from Si-g-PS to Synthesize 2 nd Brush:
[0091] The CPDB anchored Si-g-PS particles (0.5 g by weight of bare silica) dissolved in 10 mL THF were added to a dried Schlenk tube along with 20 ml methyl methacrylate and AIBN (0.01 ml of 0.005M THF solution). The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath at 60° C. for 14 hours. The polymerization was quenched in ice water. The polymer was recovered by precipitating into hexane and centrifugation at 8000 rpm. GPC results indicated the 2 nd chain has a molecular weight of 205,000 g/mol and PDI of 1.17.
5. Synthesis of Mixed Brush of Polymethyl Methacrylate and Poly(t-Butyl Methacrylate) Grafted Silica Particles by Step-by-Step RAFT Polymerization
[0092] A. Graft Polymerization of Methyl Methacrylate from CPDB Anchored Colloidal Silica Particles to Graft 1 st Chain from Surface of Particles:
[0093] A solution of methyl methacrylate (10 mL), CPDB anchored silica particles (0.5 g, 80 μmol/g), AIBN (0.600 ml, 5 mM solution in THF), and THF (10 mL) was prepared in a dried Schlenk tube. The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath at 60° C. for 3 hours. The polymerization solution was quenched in ice water and poured into cold methanol to precipitate polymer grafted silica particles. The polymer chains were cleaved by treating a small amount of particles with HF and the resulting polymer chains were analyzed by GPC. The polymer cleaved from the Si-g-PMMA particles had a molecular weight of 5000 g/mol and PDI of 1.17.
[0094] B. Cleavage of RAFT Agent from 1 st Brush:
[0095] Solid AIBN (108 mg) was added to a solution of Si-g-PMMA in THF (0.5 g in 50 ml) and heated at 65° C. under nitrogen for 30 minutes. The resulting white solution mixture was poured into 100 ml hexanes and centrifuged at 8000 rpm for 5 minutes to recover Si-g-PMMA particles.
[0096] C. Functionalization of Si-g-PS by 2 nd RAFT Agent:
[0097] The second RAFT agent was attached onto the surface of the silica which was not covered by the first polymer chain. The bare surface of the particles was functionalized by amine groups using 0.0025 ml of 3-aminopropyldimethylethoxysilane in a process similar to the first RAFT agent attachment. The second RAFT agent was attached by reaction 30 mg of activated CPDB (0.030 g) at room temperature with the amino-functional particles.
[0098] D. Graft Polymerization of t-Butyl Methacrylate from Si-g-PMMA to Synthesize 2 nd Brush:
[0099] The CPDB anchored Si-g-PMMA particles (0.105 g) dissolved in 7 ml THF were added to a dried Schlenk tube along with 0.500 ml t-butyl methacrylate and AIBN (10 μl of 0.005M THF solution). The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath at 65° C. for 12 hours. The polymerization was quenched in ice water. The polymer was recovered by precipitating into hexane and centrifugation at 8000 rpm. GPC results indicated the 2 nd chain has a molecular weight of 17,000 g/mol and PDI of 1.24.
6. Synthesis of Bimodal Polystyrene Brush Grafted Silica Particles by Step-by-Step RAFT and ATRP Polymerization
[0100] A. Graft Polymerization of Styrene from CPDB Anchored Colloidal Silica Particles to Graft 1 st Chain from Surface of Particles:
[0101] A solution of styrene (10 ml), CPDB anchored silica particles (0.3 g, 80 μmol/g), AIBN (0.240 ml, 5 mM solution in THF), and THF (10 ml) was prepared in a dried Schlenk tube. The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath at 65° C. for 4 hours. The polymerization solution was quenched in ice water and poured into cold methanol to precipitate polymer grafted silica particles. The polymer chains were cleaved by treating a small amount of particles with HF and the resulting polymer chains were analyzed by GPC. The polymer cleaved from the Si-g-PS particles had a molecular weight of 10,400 g/mol and PDI of 1.12.
[0102] B. Cleavage of RAFT Agent from 1 st Brush:
[0103] Solid AIBN (110 mg) was added to a solution of Si-g-PS in THF (0.5 g in 50 ml) and heated at 65° C. under nitrogen for 30 minutes. The resulting white solution mixture was poured into 100 ml hexanes and centrifuged at 8000 rpm for 5 minutes to recover Si-g-PS particles.
[0104] C. Functionalization of Si-g-PS by ATRP Initiator Agent:
[0105] The ATRP initiator was attached onto the surface of the silica which was not covered by the first polymer chain. A solution (0.3 g by weight of silica) of Si-g-PS was added to a two-necked round-bottom flask and diluted with 25 ml of THF. To it was added 0.025 ml of 3-trimethoxysilylpropyl-2-bromo-2-methylpropionate and the mixture was refluxed at 75° C. overnight under nitrogen protection. The reaction was then cooled to room temperature and precipitated in large amount of hexanes. The particles were then recovered by centrifugation and dispersed in THF using sonication and precipitated in hexanes again. The ATRP initiator functionalized particles were then dispersed in 10 ml of THF for further reaction.
[0106] D. ATRP Polymerization of Styrene from Si-g-PS to Synthesize 2 nd PS Brush:
[0107] The styrene monomer (10 ml), Cu(I)Cl (0.189 mmol) and Me 6 Tren ligand (0.38 mmol) was added to a Schlenk flask and degassed by purging nitrogen for 10 minutes. In another flask ATRP initiator anchored Si-g-PS particles (0.3 g by weight of silica) were dissolved in 10 mL THF and the solution was degassed using nitrogen for 10 minutes. The particle solution was then added to the Schlenk flask and the Schlenk flask was then placed in an oil bath at 90° C. for 36 hours. The polymerization was quenched in ice water. The polymer was recovered by precipitating into methanol and centrifugation at 8000 rpm, followed by redispersion in THF. The process was repeated 4 more times to remove the copper catalyst. GPC results indicated the 2 nd chain has a molecular weight of 255,000 g/mol and PDI of 1.43.
UV Analysis
[0108] In order to calculate grafting densities of RAFT agents on Syloid (silica particles, Grace Chemical, average diameter 3.2 microns) particles, a calibration curve was made using the absorbance of the RAFT agent at wavelength=308 nm at a range of 0.0269 μmol/ml to 0.42 μmol/ml ( FIG. 1 ). The calibration curve in FIG. 2 was used to determine the concentration of RAFT agents on Syloid (silica) based on the absorbance of the particular Syloid-RAFT sample at 308 nm. Concentrations are presented as μmol of RAFT/g of Syloid.
1.1 Synthesis of an Activated Trithiocarbonate
[0109] 4-Cyano-4-(dodecylsulfanylthiocarbonyl)sulfanylpentanoic acid (CTD) (1 g, 2.48 mmol), 2-mercaptothiazoline (0.295 g, 2.48 mmol), and dicyclohexylcarbodiimide (DCC) (0.613 g, 2.97 mmol) were dissolved in 20 ml of dichloromethane. (Dimethylamino)pyridine (DMAP) (30 mg, 0.25 mmol) was added slowly to the solution under ice, which was stirred at room temperature overnight under nitrogen. The solution was filtered to remove the salt. After silica gel column chromatography (5:4 mixture of hexane and ethyl acetate) and removal of solvent, the activated trithiocarbonate was obtained as a yellow oil.
1.2 Preparation of Amino-Functionalized Syloid
[0110] A suspension of Syloid (silica) particles (2.0 g) in THF (20 ml) was added to a three-necked round-bottom flask with 3-aminopropyldimethylethoxysilane (0.60 μL) and THF (80 ml). The reaction mixture was heated at 75° C. under N 2 protection overnight and then cooled to room temperature. The reaction mixture was precipitated into a large amount of hexanes (500 ml, ACS Reagent). The particles were recovered by centrifugation at 3000 rpm for 15 min. The particles were then redissolved in 20 mL of THF and reprecipitated in 100 mL of hexanes. The amino functionalized particles were dispersed directly into 50 mL of THF and used directly for the next modification.
1.3 Preparation of Trithiocarbonate Anchored Syloid
[0111] A THF solution (20 ml) of the high surface density amino-functionalized Syloid (1.8 g, 0.319 mmol of anime groups) was added dropwise to a THF solution (10 ml) of activated CTD (0.18 g, 0.351 mmol) at 0° C. After complete addition, the solution was stirred overnight at room temperature under nitrogen. The reaction mixture was then precipitated into a large amount of 4:1 mixture of cyclohexane and ethyl ether (200 ml). The particles were recovered by centrifugation at 3000 rpm for 15 min. The particles were then redissolved in 20 mL of THF and reprecipitated in 4:1 mixture of cyclohexane and ethyl ether. This dissolution-precipitation procedure was repeated another two times until the supernatant layer after centrifugation was colorless. The Syloid particles were dried under vacuum for 1 hr and subjected to analysis by UV to determine the graft density ( FIG. 3 ). The particles had a density of 36.26 μmol/g.
[0000] 1.4 Acrylamide Graft Polymerization from Trithiocarbonate Anchored Syloid
[0112] RAFT agent anchored Syloid (0.050 g, 36.36 μmol/g), dimethylsulfoxide (DMSO) (3 ml), acrylamide (AM) (0.5 g, 6.94 mmol) and trioxane (25 mg, internal standard) were added to a 15 mL Schlenk tube followed by sonication and addition of AIBN (69 μL of 10 mM DMSO solution). The tubes were subjected to three cycles of freeze-pump-thaw to remove oxygen. They were then placed in an oil bath preset to 70° C. for various intervals. The polymerizations were stopped by quenching the tubes in ice water, and the polymerization mixtures were precipitated into acetone. The polymer was collected by centrifugation of the acetone mixture at 3000 rpm for 5 min. Nuclear magnetic resonance (NMR) analysis of the reaction mixture were taken both prior to and directly after the polymerization to calculate conversion. A monomer conversion of 34% was reached after 23 h.
[0000] 1.5 General Procedures for Cleaving Grafted Polymer from Syloid
[0113] 100 mg of polyacrylamide (PAM) grafted Syloid particles was dissolved in 3 mL of DMSO. Aqueous HF (49%, 0.2 ml) was added, and the solution was allowed to stir at room temperature overnight. The solution was poured into a PTFE Petri dish and allowed to stand in a fume hood overnight to evaporate the volatiles. The recovered PAM was subjected to analysis by NMR.
2.1 Preparation of CPDB Anchored Syloid
[0114] Activated CPDB was prepared as outlined in the literature, 1 and was attached in a similar fashion as described in procedure 1.3. Grafting densities of CPDB on the syloid particles ranged from 60-142 μmol/g.
[0000] 2.2 Graft Polymerization of Acrylic Acid from CPDB Anchored Syloid
[0115] In a dried Schlenk tube, CPDB anchored Syloid (0.50 g, 30.56 μmol/g) was dissolved in DMF (14 ml). Acrylic acid (13.84 ml) and AIBN (152 μL, 0.01M in DMF) were then added to the tube. The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath preset at 65° C. The polymerization was quenched by submersion of the reaction vessel in ice water. The polymer solution was precipitated into ether, and redispersed in DMF. The precipitation-redispersion process was repeated once more.
[0116] 3.1 Preparation of Poly(PEG-co-NMS)
[0117] In a dried Schlenk flask, CTD (0.005 g, 0.0124 mmol) was dissolved in DMF (0.127 ml). To this solution was added N-methacryloxy succinimide (NMS) (0.034 g, 0.186 mmol), PEG-methacrylate (Mn: 500 g/mol), 0.093 g, 0.1858 mmoles) and AIBN (310 μL, 0.01M in DMF). The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath preset at 65° C. The polymerization was quenched by submersion of the reaction vessel in ice water. The polymer solution was precipitated into ether, and redispersed in DMF. The precipitation-redispersion process was repeated once more to obtain Poly(PEG-co-NMS) with Mn: 17,687 g/mol and PDI of 1.27.
3.2 Grafting-To Procedure for PEG Functionalized Syloid
[0118] Amine functionalized Syloid (82.5 mg, 136.6 μmol/g) was dispersed in THF (2 ml) in a round bottom flask, followed by the addition of triethylamine (17.1 mg, 0.17 mmol). The mixture was purged with nitrogen for 10 min, and the Poly(PEG-co-NMS) (17,687 g/mol, 0.845 mmol of NMS) in 1 ml THF was added via a syringe. The flask was attached to a condenser, purged for 10 min, and then stirred at 70° C. overnight. The mixture were diluted with THF (10 ml) and then centrifuged at 3000 rpm for 5 min. The particles were recovered and then dried under vacuum for 2 h. The particles were subjected to NMR analysis, where the presence of PEG and lack of signal from the succinimide group confirmed attachment of the polymer to the Syloid particles.
Preparation of Poly(PAM-co-NMS)
[0119] In a dried Schlenk flask, CTD (0.005 g, 0.0124 mmol) was dissolved in DMSO (0.8 ml). To this solution was added N-methacryloxy succinimide (0.0566 g, 0.309 mmol), acrylamide (0.089 g, 1.23 mmol) and AIBN (246 μL, 0.01M in DMSO). The mixture was degassed by three freeze-pump-thaw cycles, back filled with nitrogen, and then placed in an oil bath preset at 70° C. The polymerization was quenched by submersion of the reaction vessel in ice water. The polymer solution was precipitated into acetone, and redispersed in H 2 0. The precipitation-redispersion process was repeated once more to obtain Poly(PAM-co-NMS) with conversions of 47.83% and 80.1% for the NMS and acrylamide respectively. The Mn of the polymer was confirmed to be 15,345 g/mol with a PDI of 1.24.
3.2 Grafting-To Procedure for PAM Functionalized Syloid
[0120] Amine functionalized Syloid (82.5 mg, 136.6 μmol/g) was dispersed in THF (2 ml) in a round bottom flask, followed by the addition of triethylamine (17.1 mg, 0.17 mmol). The mixture was purged with nitrogen for 10 min, and the Poly(PAM-co-NMS) in 2 ml THF was added via a syringe. The flask was attached to a condenser, purged for 10 min, and then stirred at 70° C. overnight. The mixture was diluted with acetone (10 ml) and then centrifuged at 3000 rpm for 5 min. The particles were recovered and then dried under vacuum for 2 h. The particles were subjected to NMR analysis, where the presence of PAM and lack of signal from the succinimide group confirmed attachment of the polymer to the Syloid particles.
4.1 Filtration Procedure
[0121] Filter columns were made with a plug of cotton, sand (1 mm) and filter material (4 cm) in a Fisherbrand™ Disposable Borosilicate Glass Pasteur Pipette (length: 5.75 in., 146 mm). Filter materials used include Syloid particles, silica gel (70-200 μm), and diatomaceous earth. A typical method involved the dissolution of the sample in water (1 ml) and its addition to the column to be filtered into a vial. The vial was then freeze-dried to calculate the mass of its contents. All experiments involved three sets of samples including the control (1 ml of water), free polymer (for PAA, Mn:1800 g/mol) and Syloid-polymer. Retention efficiencies were calculated based on the amount of Syloid-polymer and free polymer had passed through the column compared to the original amounts of each used. A retention efficiency of 0% for the free polymer indicated that all the free polymer had passed through the column. Conversely, a retention efficiency of 100% for the Syloid-polymer indicated that none of the Syloid-polymer had passed through the column.
4.2 Filtration Procedure (Extended Wash)
[0122] In order to simulate real world conditions, extended washing procedures were tested to see the retention efficiency after several additions of water to the column. In this procedure, samples were dissolved in water (2 ml), passed through the column, and followed up with two separate additions of water (1 ml) each. Similar to the procedure outlined above, each experiment included a control (2 ml of water), and the free polymer and Syloid-polymer respectively.
Results
[0123] 4.2.1
[0000]
TABLE 1
Syloid-PAA (Mn: 140,000 g/mol), water (1 ml), Filter
(Diatomaceous Earth)
Amount
Amount After
Efficiency
Adjusted
Used (mg)
Filtration (mg)
(%)
Efficiency (5)
Control
—
1
PAA only
15
8
46.7
53.3
Syloid-PAA
15
1
93.3
100
[0124] Polyacrylic acid of 140,000 g/mol on Syloid silica particles prepared by grafting-from techniques was tested by the procedures outlined in section 4.1. The adjusted efficiency data showed that 53.3% of the free polymer was retained in the column, as compared to 100% retention of the Syloid-polymer in the diatomaceous earth.
[0000] 4.2.2
[0000]
TABLE 2
Syloid-PAA (Mn: 200,000 g/mol), water (1 ml), Filter
(Diatomaceous Earth)
Amount
Amount After
Retention
Adjusted
Used (mg)
Filtration (mg)
Efficiency (%)
Efficiency (5)
Control
—
0.05
PAA
22
8
63.63
65.9
Syloid-
22
1.5
93.1
95.4
PAA
[0125] Polyacrylic acid of 200,000 g/mol on Syloid silica particles prepared by grafting-from techniques was tested by the procedures outlined in section 4.1. The adjusted efficiency data showed that 65.9% of the free polymer was retained in the column, as compared to 95.4% retention of the Syloid-polymer in the diatomaceous earth.
[0000] 4.2.3
[0000]
TABLE 3
Syloid-PAA (Mn: 140,000 g/mol), water (2 ml), Extended wash
with water (2 ml), Filter (Diatomaceous Earth)
Amount
Amount After
Retention
Adjusted
Used (mg)
Filtration (mg)
Efficiency (%)
Efficiency (%)
Control
—
0.5
PAA
14
13.6
2.85
6.4
Syloid-
13
2
84.6
88.46
PAA
[0126] Polyacrylic acid of 140,000 g/mol on Syloid silica particles prepared by grafting-from techniques was tested by the procedures outlined in section 4.2.1. The adjusted efficiency data showed that 6.4% of the free polymer was retained in the column, as compared to 88.46% retention of the Syloid-polymer in the diatomaceous earth.
[0000] 4.2.4
[0000]
TABLE 4
Syloid-PAA (Mn: 200,000 g/mol), water (2 ml), Extended
wash with water (2 ml), Filter (Diatomaceous Earth)
Amount
Amount After
Retention
Adjusted
Used (mg)
Filtration (mg)
Efficiency (%)
Efficiency (%)
Control
—
0.1
PAA
16
15.5
3.1
3.75
Syloid-
16
2.7
83.1
83.7
PAA
[0127] Polyacrylic acid of 200,000 g/mol on Syloid silica particles prepared by grafting-from techniques was tested by the procedures outlined in section 4.2.1. The adjusted efficiency data showed that 3.75% of the free polymer was retained in the column, as compared to 83.7% retention of the Syloid-polymer in the diatomaceous earth.
[0000] 4.2.5
[0000]
TABLE 5
Syloid-PEG (Grafted-to. Mn: 17,687 g/mol, PDI: 1.27), PEG-co-NMS
(Mn: 38,888, PDI: 1.46), water (2 ml), Extended wash with water
(2 ml), Filter (Diatomaceous Earth)
Amount
Adjusted
Amount
After
Retention
Efficiency
Used (mg)
Filtration (mg)
Efficiency (%)
(%)
Control
—
1.7
PEG-co-NMS
78
58
25.64
27.8
Syloid-PEG
20
2
90
98.5
[0128] PEG of 17,687 g/mol on Syloid silica particles prepared by grafting-to techniques was tested by the procedures outlined in section 4.2.1. The adjusted efficiency data showed that 27.8% of the free polymer was retained in the column, as compared to 98.5% retention of the Syloid-polymer in the diatomaceous earth.
[0000] 4.2.6
[0000]
TABLE 6
Syloid-PAM (Grafted-from. Mn: 180,000 g/mol), Free PAM
(Mn: 310,000 g/mol), water (2 ml), Extended wash with water
(2 ml), Filter (Diatomaceous Earth)
Amount
Amount After
Retention
Adjusted
Used (mg)
Filtration (mg)
Efficiency (%)
Efficiency (%)
Control
—
1.8
PAM
25
8.7
65.2
72.4
Syloid-
34
7.2
78.8
88.46
PAM
[0129] Polyacrylamide of 180,000 g/mol on Syloid silica particles prepared by grafting-from techniques was tested by the procedures outlined in section 4.2.1. The adjusted efficiency data showed that 72.4% of the free polymer of 310,000 g/mol was retained in the column, as compared to 84.1% retention of the Syloid-polymer in the diatomaceous earth.
Reaction Schemes
[0130]
[0000]
[0000]
[0000]
[0000]
[0000]
[0131] These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood the aspects of the various embodiments may be interchanged both, in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in the appended claims.
[0132] While the preferred embodiments of the invention have been illustrated and described, it will be understood that the invention is not so limited. Numerous modifications, alterations, variants, changes, additions and substitutions and equivalents will occur to those with ordinary skill in the art without departing from the spirit and scope of the present invention as described in the claims.
REFERENCES
[0000]
(1) Li, C. H., J.; Ryu, C. J.; Benicewicz, B. C. Macromolecules 2006, 31, 3175. | The present invention relates to improved chemical additives for use in hydraulic fracturing fluids for the recovery of oil or natural gas entrained in deep-layer shale formations. Many chemical agents currently in use in such water/sand (or other proppants) mixtures could pose human and animal health risks if these chemicals migrate from the shale beds into the environment contaminating the water table, rivers, streams and lakes. The fracturing fluid chemical additives of this invention are designed to be retained or anchored in or near the deep shale layers and are prevented, or greatly delayed from upward migration. Specifically, many chemical additives required for proper fracturing fluid performance can be chemically bonded to inert particulate materials before incorporation into said fluids. The fracturing fluid chemical additives are able to perform their function in the shale fracturing process, and then become nearly permanently trapped in the shale layers protecting the environment above. | 4 |
TECHNICAL FIELD
[0001] The present invention relates to computer managed communication networks such as the World Wide Web (Web) and, particularly, to systems, processes and programs for the distribution of computer power, i.e. distributed data processing carried out over the Web.
BACKGROUND OF RELATED ART
[0002] The past decade has been marked by a technological revolution driven by the convergence of the data processing industry with the consumer electronics industry. The effect has, in turn, driven technologies that have been known and available but relatively quiescent over the years. A major one of these technologies is the Internet or Web (the two terms are used interchangeably) related distribution of documents, media and programs. The convergence of the electronic entertainment and consumer industries with data processing exponentially accelerated the demand for wide ranging communications distribution channels, and the Web or Internet, which had quietly existed for over a generation as a loose academic and government data distribution facility, reached “critical mass” and commenced a period of phenomenal expansion. With this expansion, businesses and consumers have direct access to all matter of documents, media and computer programs.
[0003] Because of the pervasiveness of the Internet or Web, it is expected that it would be considered as an available network for distributed data processing or distributed computing. Distributed computing has conventionally been used for projects that require large amounts of computing power. One typical example is finding a 100,000 digit prime number. It has been estimated that testing just one 100,000 prime number would take a 500 mhz computer one year. Thus, such tasks have been cumbersome for even super computers. This need initially gave rise to distributed computing to cover projects related to the environment, genetics, disease control and like scientific research related to the preservation and advancement of civilization. Now, with the availability of the Web linking computers throughout the world, important research projects requiring the application of tremendous computing power have been using volunteers to permit research project management to distribute computing functions over the Web to the volunteer computers that perform such functions as secondary or background functions that do not interfere with the primary functioning of the volunteer computers. In such distributed computing, the reward to the volunteer computer host is the spiritual compensation that they are doing something in the progress of civilization.
[0004] On the other hand, distributed data processing has been available for years within business organizations to break down functions requiring large amounts of computer power over relatively short periods of time, and networks and even the Web have been used in the distribution of such data processing internal to business organizations.
[0005] However, in light of the extensive distributive network offered by the Web to all matter of computers and computing power, together with continuous advancement of distributive computing technology, greater opportunities are offered for distributive computing over the Web. The present invention develops such an approach to distributive computing over the Web.
SUMMARY OF THE PRESENT INVENTION
[0006] The present invention provides a method, system and program of doing business that enables a computer power service broker operating over the Web to distribute and track such distribution of computer power. The computer power service broker solicits: each of a plurality of client computer stations on the Web to offer for general distribution over the Web computer power in excess to the computer power requirements of each respective client computer station; and a plurality of consumer stations on the Web to request the performance of functions requiring computer power. The broker then distributes each of said requested functions requiring computer power among a plurality of said client stations offering said computer power; and then tracks and bills consumer stations for computer power used in performance of requested functions. Finally, the computer power broker tracks and compensates the client stations for the excess computer power that they contribute in performance of the requested functions. The compensation may be determined by the market value of the broken down functions or tasks.
[0007] It should be noted that with such a broker arrangement, the consumer stations need not be the previously described projects or organizations requiring tremendous amounts of computer power for large scale scientific research. The consumers may just be stations wishing to outsource, i.e. request the performance of, some computer functions. With the current emphasis on “lean and mean” business organizations, it may very well be the case that a business may wish to wait before it is ready to invest in more data processing resources upon an increase in computer power demands that may turn out to be temporary. Under such conditions, businesses may be very amenable to the outsourcing of computer functions enabled by this invention.
[0008] On the other hand, in the case where the client computer makes a voluntary contribution wherein the consumer stations requesting the performance of functions requiring computer power are owned by charitable organizations, then the step of compensating said client stations for said computer power compensates said client stations by providing a Web document indicating the contribution of the market value of the computer power supplied.
[0009] In the fundamental application of the present invention, the market value of the computer power provided by each client station is determined by the amount of data processed and the type of data processing used in processing the data.
[0010] When a client computer station solicited by the computer power service broker agrees to participate in the distributed Web computing system, the client station permits the computer power service broker to access, via the Web, the computer power of said client station, and there is then distributed through the broker via the Web to said client station, a process, e.g. program or routine, permitting said computer power service broker to access the computer power of said client station.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art by reference to the following drawings, in conjunction with the accompanying specification, in which:
[0012] FIG. 1 is a block diagram of a data processing system including a central processing unit and network connections via a communications adapter that is capable of implementing the receiving display station on which the received Web pages may be displayed. The system may be used for conventional servers used throughout the Web for Web access servers, source database servers, as well as the servers used by the service providers in accordance with this invention;
[0013] FIG. 2 is a generalized diagrammatic view of a Web portion upon which the present invention may be implemented;
[0014] FIG. 3 is a general flowchart of a program set up to implement the present invention for a computer power service broker tracking distributed computer power to users and compensating client computer power providers; and
[0015] FIG. 4 is a flowchart of an illustrative run of the program set up in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Referring to FIG. 1 , a typical data processing terminal is shown that may function as the receiving, both computer power consumer and computer power provider, clients display station on which the received Web documents may be displayed. The system may also be used for conventional servers used throughout the Web for Web servers, as well as the servers used by the computer power service brokers in accordance with this invention.
[0017] Before there is any further description of the respective computer functions in the present invention, a generalized example of distributed computing via the Web will be considered with respect to FIG. 2 , which shows a generalized portion of the Web to illustrate the invention. It will be helpful to understand from a more general perspective the various elements and methods that may be related to the present invention. Since a major aspect of the present invention is directed to documents, such as Web pages and media content therein, transmitted over networks, an understanding of networks and their operating principles would be helpful. We will not go into great detail in describing the networks to which the present invention is applicable. Reference has also been made to the applicability of the present invention to a global network, such as the Internet or Web. For details on Internet nodes, objects and links, reference is made to the text, Mastering the Internet, G. H. Cady et al., published by Sybex Inc., Alameda, Calif., 1996.
[0018] The Internet or Web is a global network of a heterogeneous mix of computer technologies and operating systems. Higher level objects are linked to the lower level objects in the hierarchy through a variety of network server computers. These network servers are the key to network distribution, such as the distribution of Web pages and related documentation. In this connection, the term “documents” is used to describe data transmitted over the Web or other networks and is intended to include Web pages with displayable text, graphics and other images, as well as computer programs. This displayable information may be still, in motion or animated, e.g. animated GIF images.
[0019] Web documents are conventionally implemented in HTML language, which is described in detail in the text entitled Just Java, van der Linden, 1997, SunSoft Press, particularly at Chapter 7, pp. 249-268, dealing with the handling of Web pages; and also in the text, Mastering the Internet, particularly at pp. 637-642, on HTML in the formation of Web pages. In addition, aspects of this description will refer to Web browsers. A general and comprehensive description of browsers may be found in the above-mentioned Mastering the Internet text at pp. 291-313. More detailed browser descriptions may be found in the text, Internet: The Complete Reference, Millennium Edition, M. L. Young et al., Osborne/McGraw-Hill, Berkeley Calif., 1999, Chapter 19, pp. 419-454, on the Netscape Navigator; Chapter 20, pp. 455-494, on the Microsoft Internet Explorer; and Chapter 21, pp. 495-512, covering Lynx, Opera and other browsers.
[0020] As for distributed computing or data processing systems, in its broadest sense, it may involve an environment wherein idle CPU cycles and storage spaces of from tens to thousands of computers networked together, e.g. over the Web to work on problems that conventionally have been processing intensive. Such distributed computing over the Web and like networks was, in the past, hampered by bandwidth limitations. However, recent dramatic increases in available bandwidth, as well as the greatly increased CPU power on the ubiquitous desktop computers, has made potential applications for distributed computing via the Internet or Web much more practical.
[0021] The concepts of the present invention are applicable to grid computing that usually involves larger computer systems initially set up for distributed computing so that the computing power needed is distributed among powerful workstations, even mainframes and super computers, and the problems involve the processing of very large data sets. In the embodiment of the invention to be described, the distributed computing will involve the soliciting and pooling of the computer power of many networked end users or receiving stations, “client computers”, of more limited processing power and whose primary function is not distributed computing.
[0022] It is primarily to this latter group of client computers that the present invention is directed. In the present invention, a Web service provider, such as service provider 53 in FIG. 2 , assumes a computer power service broker in order to track the distributed computer power from the group of client computer power supplier stations 63 through 66 on the Web supplied to computer power consumer stations 57 , 42 and 43 also on the Web; and accordingly bill the consumer stations for the computer power used and compensate the client supplier stations for the supplied computer power. For purposes of the present embodiment, computer 57 serves as a typical receiving Web display station that will access Web documents, e.g. pages that are displayed 56 . Reference may be made to the above-mentioned Mastering the Internet, pp. 136-147, for typical connections between local display stations to the Web via network servers; any of which may be used to implement the system on which this invention is used. The system embodiment of FIG. 2 has a host-dial connection. Such host-dial connections have been in use for over 30 years through network access servers 53 that are linked 61 to the Web 60 . The Web server 53 functions as a computer power service broker, and may be maintained by a Web Service Provider to display terminal 57 . Such Web or Internet Service Providers (ISPs) are described generally in the above-mentioned text, Internet: The Complete Reference, Millennium Edition at pages 14-18. The Web server 53 is accessed by the receiving terminal 57 through a normal dial-up telephone linkage 58 via modem 54 , telephone line 55 and modem 52 . Any conventional digital or analog linkages, including wireless connections, are also usable. Web browser program 59 functions as described above to access the service provider 53 that functions herein as the computer power service broker. Receiving terminal computers 42 and 43 that are similar to terminal 57 are connected to the computer power service broker 53 and are just illustrative of other computer power consuming terminals on the Web.
[0023] Now in an illustrative operation, computer power broker 53 solicits computer stations on the Web for jobs or projects that may require distributed computing or data processing. Assume that each of Web computer stations 57 , 42 and 43 responds, e.g. interactively, to a Web page from broker 53 offering to have such projects completed through distributed processing. Broker 53 has also solicited client computer power supplier stations 63 through 66 together with their respective database resources 67 through 70 to agree to do the distributed data processing as required by broker 53 . This provision of computer power and storage resources by computer stations 63 through 66 is agreed to be only resources and power in excess of those required by stations to perform their own respective functions. At this point, stations 63 through 66 have interactively, via the Web through their Web service provider 62 , agreed to participate in the distributed data processing during background or computer idle time. As will be hereinafter described in greater detail with respect to the programming of the present invention, service provider broker 53 distributes and installs over the Web 60 via the server of service provider 62 a relatively simple program routine that detects when the computer station 63 through 66 is idle and notifies a management server, e.g. server 62 . The client computer 63 through 66 then receives a data package via the Web that it runs when it has spare CPU cycles and sends the results back through server 62 via the Web to broker 53 that collects the distributed processing, puts the job or project function results together, bills the respective consumer station 57 , 42 or 43 and compensates the client computer power providers station compensation, as will be hereinafter described.
[0024] Returning now to the description of the basic computer of FIG. 1 , the illustrative computer shown may function as any of stations 42 , 42 , 57 and 63 through 67 . The system may also be used for conventional servers used throughout the Web for Web access servers, source database servers, as well as the servers used by the service providers in accordance with this invention, e.g. for the computer power service broker. A central processing unit (CPU) 10 , such as one of the PC microprocessors or workstations, e.g. RISC System/6000™ series available from International Business Machines Corporation (IBM), or Dell PC microprocessors, is provided and interconnected to various other components by system bus 12 . An operating system 41 runs on CPU 10 , provides control and is used to coordinate the function of the various components of FIG. 1 . Operating system 41 may be one of the commercially available operating systems, such as IBM's AIX 6000™ operating system or Microsoft's WindowsXP™ or Windows2000™, as well as UNIX and other IBM AIX operating systems. Application programs 40 , controlled by the system, are moved into and out of the main memory Random Access Memory (RAM) 14 . These programs include the program of the present invention that will be described hereinafter for operations wherein the system of FIG. 1 functions as the server used by the service providers in accordance with this invention. The programs will distribute job or project computer functions requested to be done by computer power consumer stations to the client computers providing the computer power and, accordingly, bill and compensate the respective computer hosts and owners. A Read Only Memory (ROM) 16 is connected to CPU 10 via bus 12 and includes the Basic Input/Output System (BIOS) that controls the basic computer functions. RAM 14 , I/O adapter 18 and communications adapter 34 are also interconnected to system bus 12 . I/O adapter 18 may be a Small Computer System Interface (SCSI) adapter that communicates with the disk storage device 20 . Communications adapter 34 interconnects bus 12 with an outside Internet or Web network. I/O devices are also connected to system bus 12 via user interface adapter 22 and display adapter 36 . Keyboard 24 and mouse 26 are all interconnected to bus 12 through user interface adapter 22 . It is through such input devices that the user may interactively relate to the programs of this invention. Display adapter 36 includes a frame buffer 39 that is a storage device that holds a representation of each pixel on the display screen 38 . Images may be stored in frame buffer 39 for display on monitor 38 through various components, such as a digital to analog converter (not shown) and the like. By using the aforementioned I/O devices, a user is capable of inputting information to the system through keyboard 24 or mouse 26 and receiving output information from the system via display 38 .
[0025] FIG. 3 is a flowchart showing the development of a process according to the present invention for distributing job or project computer functions requested to be done by computer power consumer stations to the client computers providing the computer power, and accordingly billing and compensating the respective computer hosts and owners. Many of the programming functions in the process of FIG. 3 have already been described in general with respect to FIGS. 1 and 2 . In the Web, service providers are available between the Web document requesting and receiving display stations and other of such requesting and receiving stations and the database sources on the Web. These Web service providers conventionally provide servers to aid users in accessing documents from the Web and/or providing servers to distribute documents to and from the Web receiving computer stations and other database sources, e.g. Web sites. In such a Web environment, there is set up distributed computing in which client Web stations supply computer power to perform functions for Web computer stations, i.e. consumer stations requesting outside distributed computer power to perform such functions under the control of a computer power service broker, step 71 . In the preferred implementation, as described above, a Web service provider would take this broker function. The service provider/broker would solicit computer stations on the Web to offer their excess computer power for carrying out distributed functions over the Web, step 72 . The service broker would also be set up to solicit other computer stations on the Web having functions needing additional computer power beyond their capacity to carry out high computation projects to request the distributed performance of such functions, step 73 . An implementation is set up in the service provider broker for distributing each requested function requiring computer power among the client stations offering such power for distribution, step 74 . The service broker is set up to total the computer power provided and to bill the consumer stations for the total computer power provided. The charge for the computer power could be based upon market value of such power, e.g. the total number of bytes processed; or the total of computer time used. Both of these calculations could be varied dependent on the type of function being performed, step 75 . The service broker is also set up to track the computer power provided by each client station in the distributed function and for compensating the respective client stations for such functions, step 76 . A further implementation, step 77 , is set up for determining the market value of the computer power supplied as determined in step 76 by using the criteria set forth above with respect to step 75 . A special compensation arrangement is set up for a prevalent arrangement wherein the computer power is supplied to a charitable organization. In such a set up, the client computer is provided with a receipt for the charitable contribution of the value of the provided computer power instead of a payment, step 78 . In the Web set up, an implementation is provided in which the service broker installs over the Web into each client station wishing to participate in the distribution, a program routine that will enable the broker to access and distribute the computer power and to track and compensate for such supplied computer power, step 79 .
[0026] The running of the process set up in FIG. 3 will now be described with respect to the flowchart of FIG. 4 . First, step 81 , a determination is made as to whether there has been a request for computer power by a user or consumer computer station. If No, such a request is awaited. If Yes, then step 82 , the service broker breaks down the requested function into a set of subfunctions. These subfunctions are distributed to a plurality of participating client computers over the Web, step 83 . The distributed subfunctions are carried out until a determination is made in step 84 that Yes, all such subfunctions have been completed. Then, step 85 , the respective market values of all of the subfunctions performed are calculated, as well as the total market value of the whole function. At this point, a determination is made as to whether the requester or consumer is a charitable organization, step 86 . If Yes, then each client is sent a receipt for the value of his computer power supplied as a charitable contribution, step 87 . If No, then the requesting consumer station is billed for the total computer power supplied market value, step 88 , and each client station is paid for its supplied computer power, step 89 . At this point, or after step 87 , a determination may conveniently be made as to whether the session is at an end, step 90 . If Yes, it is exited. If No, the process is returned to initial step 81 where the next request is awaited.
[0027] Although certain preferred embodiments have been shown and described, it will be understood that many changes and modifications may be made therein without departing from the scope and intent of the appended claims. | A method of doing business that enables a computer power service broker operating over the World Wide Web (Web) to distribute and track such distribution of computer power. The computer power service broker solicits: each of a plurality of client computer stations on the Web to offer for general distribution over the Web computer power in excess to the computer power requirements of each respective client computer station; and a plurality of consumer stations on the Web to request the performance of functions requiring computer power. The broker then distributes each of said requested functions requiring computer power among a plurality of said client stations offering said computer power and then tracks and bills consumer stations for computer power used in performance of requested functions. Finally, the computer power broker tracks and compensates the client stations for the excess computer power that they contribute in performance of the requested functions. The compensation may be determined by the market value of the broken down functions or tasks. | 6 |
[0001] This claims priority to U.S. Ser. No. 60/563,096 filed Apr. 16, 2004; U.S. Ser. No. 60/545,771 filed Feb. 19, 2004; U.S. Ser. No. 60/534,065 filed Jan. 2, 2004; and U.S. Ser. No. 60/469,469 filed May 8, 2003.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to textile and fiber-based medical devices derived from poly-4-hydroxybutyrate and its copolymers.
[0003] Poly-4-hydroxybutyrate (available from Tepha, Inc., Cambridge, Mass. as PHA4400) is a strong pliable thermoplastic that is produced by a fermentation process (see U.S. Pat. No. 6,548,569 to Williams et al.). Despite its biosynthetic route, the structure of the polyester is relatively simple ( FIG. 1 ). The polymer belongs to a larger class of materials called polyhydroxyalkanoates (PHAs) that are produced by numerous microorganisms, Steinbüchel, A. Polyhydroxyalkanoic acids, Biomaterials, 123-213 (1991); Steinbüchel A., et al. Diversity of Bacterial Polyhydroxyalkanoic Acids, FEMS Microbial. Lett. 128:219-228 (1995); and Doi, Y. Microbial Polyesters (1990). In nature these polyesters are produced as storage granules inside cells, and serve to regulate energy metabolism. They are also of commercial interest because of their thermoplastic properties, and relative ease of production. Several biosynthetic routes are currently known to produce poly-4-hydroxybutyrate, as shown in FIG. 2 . Chemical synthesis of poly-4-hydroxybutyrate has been attempted, but it has been impossible to produce the polymer with a sufficiently high molecular weight necessary for most applications, Hori, Y., et al. Chemical Synthesis of High Molecular Weight poly(3-hydroxybutyrate-co-4-hydroxybutyrate, Polymer 36:4703-4705 (1995).
[0004] Tepha, Inc. (Cambridge, Mass.) produces PHA4400 and related copolymers for medical use, and has filed a Device Master Files with the United States Food and Drug Administration (FDA) for PHA4400. Related copolymers include 4-hydroxybutyrate copolymerized with 3-hydroxybutyrate or glycolic acid (U.S. Ser. No. 60/379,583 to Martin & Skraly, U.S. Pat. No. 6,316,262 to Huisman et al., and U.S. Pat. No. 6,323,010 to Skraly et al.). Tepha has also filed a Device Master File with the United States FDA for copolymers containing 3-hydroxybutyrate and 4-hydroxybutyrate. Methods to control molecular weight of PHA polymers have been disclosed by U.S. Pat. No. 5,811,272 to Snell et al., and methods to purify PHA polymers for medical use have been disclosed by U.S. Pat. No. 6,245,537 to Williams et al. PHAs with degradation rates in vivo of less than one year have been disclosed by U.S. Pat. No. 6,548,569 to Williams et al. and PCT WO 99/32536 to Martin et al. The use of PHAs as tissue engineering scaffolds has also been disclosed by U.S. Pat. No. 6,514,515 to Williams, and other applications of PHAs have been reviewed in Williams, S. F., et al. Applications of PHAs in Medicine and Pharmacy, in Biopolymers, Polyesters, III Vol. 4:91-127 (2002).
[0005] In the practice of surgery there currently exists a need for absorbable fibers and surgical meshes with improved performance. For example, there is currently a need for an absorbable monofilament fiber with a prolonged strength retention that can be used as a suture material. Such a product would potentially be useful in the treatment of patients with diabetes, obesity, nutritional impairment, compromised immune systems, or other conditions such as malignancy or infection that compromise wound healing.
[0006] There also exists a need for improved surgical meshes. For example, an absorbable hernia mesh with prolonged strength retention could have many advantages over the non-absorbable synthetic meshes currently used in hernia operations (Klinge, U., et al., Functional Assessment and Tissue Response of Short- and Long-term Absorbable Surgical Meshes, Biomaterials 22:1415-1424 (2001). Long-term implantation of these non-absorbable meshes is not considered ideal because they can lead to complications such as adhesions (fistula formation), pain, and restriction of physical capabilities (Klinge et al., 2001). If implanted into surgical sites that are contaminated or have the potential to become contaminated, 50-90% of these non-absorbable implants will need to be removed (Dayton et al. 1986). These implants are also not ideal for use in pediatric patients where they could hinder growth (Klinge et al., 2001). To date, the use of absorbable synthetic surgical meshes in hernia repair has been found to almost invariably result in large incisional hernias that require revision operations because of the relatively short-term strength retention of these materials (Klinge et al., 2001). However, it is thought that an absorbable hernia mesh with prolonged strength retention could solve this problem providing a mechanically stable closure, reduce the incidence of adhesions and risks of infection, and be suitable for use in pediatric patients.
[0007] In addition to the need for improved meshes for hernia repair, there are also needs for improved meshes and patches for other procedures. In pericardial repair there exists a need for a surgical material that will prevent adhesions between the sternum and heart following open-heart surgery. There are also similar needs to prevent adhesions in spinal and gynecology procedures that could be addressed with improved surgical meshes and patches.
[0008] Biomaterial patches derived from animal and human tissue are currently used fairly extensively in cosmetic surgery, cardiovascular surgery, general surgery (including hernia repair), and in urology and gynecology procedures for the treatment of conditions that include vaginal prolapse and urinary incontinence. There is however reported to be growing concern about the use of animal and human derived biomaterials because of the risks associated with disease transmission. Synthetic absorbable meshes and patches that may offer decreased risks of disease transmission are currently limited, can be inflammatory, and do not provide prolonged strength retention. Thus there currently exists a need to develop new absorbable meshes for these procedures as well. Ideally, these products should have prolonged strength retention, induce minimal inflammatory responses that resolve, provide mechanically stable reinforcement or closure, offer anti-adhesion properties (where necessary), minimize the risks of disease transmission, and after absorption leave a healthy natural tissue structure.
[0009] There is thus a need to develop absorbable fibers with prolonged strength retention that could be used as suturing materials, or in surgical meshes. The latter, offering longer-term mechanical stability, could also be used in other procedures such as pelvic floor reconstruction, urethral suspension (to prevent stress incontinence using the mesh as a sling), pericardial repair, cardiovascular patching, cardiac support (as a sock that fits over the heart to provide reinforcement), organ salvage, elevation of the small bowel during radiation of the colon in colorectal cancer patients, retentive devices for bone graft or cartilage, guided tissue regeneration, vascular grafting, dural substitution, nerve guide repair, as well as in procedures needing anti-adhesion membranes and tissue engineering scaffolds. Strong absorbable fibers could also find other uses, for example, in synthetic ligament and tendon devices or scaffolds. Further uses include combinations with other synthetic and natural fibers, meshes and patches. For example, the absorbable fibers and devices such as meshes and tubes derived from the fibers could be combined with autologous tissue, allogenic tissue, and/or xenogenic tissues to provide reinforcement, strengthening and/or stiffening of the tissue. Such combinations could facilitate implantation of the autologous, allogenic and/or xenogenic tissues, as well as provide improved mechanical and biological properties. Combination devices could be used for example in hernia repair, mastopexy/breast reconstruction, rotator cuff repair, vascular grafting/fistulae, tissue flaps, pericardial patching, tissue heart valve implants, bowel interposition, and dura patching.
[0010] It is therefore an object of this invention to provide absorbable fibers, surgical meshes, and medical devices with one or more of the following features: prolonged strength retention in vivo, anti-adhesion properties, minimal inflammatory reaction upon implantation, minimal risk for disease transmission or to potentiate infection, remodeling in vivo to a healthy natural tissue.
[0011] It is another object of this invention to provide methods for fabricating the articles and devices with prolonged strength retention.
[0012] It is yet another object of the invention to provide absorbable multifilament fibers, and methods for fabricating these multifilaments into surgical meshes.
[0013] It is still yet another object of the invention to combine the fibers and meshes with autologous, allogenic and/or xenogenic tissues to provide improved mechanical, biological and handling properties of the autologous, allogenic and/or xenogenic tissues.
SUMMARY OF THE INVENTION
[0014] Absorbable polyester fibers, braids, and surgical meshes with prolonged strength retention have been developed. These devices are preferably derived from biocompatible copolymers or homopolymers of 4-hydroxybutyrate. These devices provide a wider range of in vivo strength retention properties than are currently available, and offer additional benefits such as anti-adhesion properties, reduced risks of infection or other post-operative problems resulting from absorption and eventual elimination of the device, and competitive cost.
[0015] The devices are also particularly suitable for use in pediatric populations where their absorption should not hinder growth, and provide in all patient populations wound healing with long-term mechanical stability. The devices may additionally be combined with autologous, allogenic and/or xenogenic tissues to provide implants with improved mechanical, biological and handling properties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is the chemical structure of poly-4-hydroxybutyrate (P4HB, poly-4-hydroxybutyrate).
[0017] FIG. 2 shows some of the known biosynthetic pathways for the production of P4HB. Pathway enzymes are: 1. Succinic semialdehyde dehydrogenase, 2. 4-hydroxybutyrate dehydrogenase, 3. diol oxidoreductase, 4. aldehyde dehydrogenase, 5. Coenzyme A transferase and 6. PHA synthetase.
[0018] FIG. 3 is a graph of strength retention data of PHA4400 fibers (in vitro and in vivo) compared with PDS control fiber (in vivo).
[0019] FIG. 4 is a graph comparing the tensile mechanical properties of PHA4400 and commercially available monofilament sutures.
[0020] FIG. 5 is a graph of the degradation of PHA4400 (P4HB) samples in vivo compared to in vitro controls. The Mw for implanted (in vivo) and buffer control sutures (in vitro) is plotted versus time.
[0021] FIG. 6 is a graph of the ratio of mass and length of the PHA4400 sutures (in vitro and in vivo) plotted as a function of degradation time.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Absorbable fibers and meshes with prolonged strength retention have been developed.
I. DEFINITION
[0023] Strength retention refers to the amount of time that a material maintains a particular mechanical property following implantation into a human or animal. For example, if the tensile strength of an absorbable fiber decreased by half over 3 months when implanted into an animal, the fiber's strength retention at 3 months would be 50%.
[0024] Biocompatible refers to the biological response to the material or device being appropriate for the device's intended application in vivo. Any metabolites of these materials should also be biocompatible.
[0025] Poly-4-hydroxybutyrate means a homopolymer comprising 4-hydroxybutyrate units. It may be referred to as P4HB, PHA4400 or TephaFLEX™ biomaterial and is manufactured by Tepha Inc., Cambridge, Mass.
[0026] Copolymers of poly-4-hydroxybutyrate mean any polymer comprising 4-hydroxybutyrate with one or more different hydroxy acid units.
II. SOURCE OF POLY-4-HYDROXYBUTYRATE AND COPOLYMERS THEREOF
[0027] Tepha, Inc. of Cambridge, Mass. produces poly-4-hydroxybutyrate and copolymers thereof using transgenic fermentation methods.
III. POLY-4-HYDROXYBUTYRATE FIBERS WITH PROLONGED STRENGTH RETENTION
[0028] Around 1984, a division of Johnson and Johnson (Ethicon) first introduced a monofilament synthetic absorbable suture known as PDS™, made from polydioxanone. This suture retains about 50% of its strength up to 6 weeks after implantation, and is completely absorbed in the body within 6 months. Davis and Geck subsequently introduced a monofilament suture based on a copolymer of glycolide and trimethylene carbonate that is sold under the tradename of Maxon™. This suture has a similar strength retention to PDS™. Two other monofilament sutures were introduced more recently. Monocryl™ based on segmented copolymers of glycolide and caprolactone, and Biosyn™ based on a terpolymer of glycolide, p-dioxanone, and trimethylene carbonate. Monocryl™ is reported to have a 20-30% breaking strength after 2-3 weeks, and be completely absorbed after 3-4 months. Biosyn™ has an absorption profile similar to Monocryl™. Despite continued innovation in the development of absorbable synthetic monofilament sutures there is still a need for a synthetic absorbable suture with extended strength retention for patients requiring long-term wound support, for example, a monofilament suture with 50% strength retention at 3-6 months (after implantation). There are also limited options for synthetic absorbable meshes with prolonged strength retention.
[0029] U.S. Pat. No. 6,548,569 to Williams et al. discloses that poly-4-hydroxybutyrate has a slower absorption rate in vivo than many materials used as absorbable sutures, and provides absorption data for unoriented poly-4-hydroxybutyrate films and porous samples. It does not, however, disclose the strength retention of fibers of poly-4-hydroxybutyrate following implantation.
[0030] It has now been discovered that oriented fibers of PHA4400 and copolymers thereof can be prepared with tensile strengths comparable to existing synthetic absorbable suture fibers (such as PDS™), but have a prolonged strength retention in vivo of over 20-30% at 3-6 months. In comparison, a control PDS suture had little tensile strength remaining after 12-15 weeks.
[0031] It has also been discovered that oriented poly-4-hydroxybutyrate fibers can be used to prepare surgical meshes and tubes with prolonged strength retention. These fiber and textile devices may further be combined with autologous, allogenic and/or xenogenic tissues to impart improved properties to these implantable tissues. Properties that can be improved through this combination include mechanical properties such as tensile strength and modulus, for example, to reinforce the tissues to make them stronger, stiffer, more durable, and easier to implant.
[0032] Non-limiting examples are given herein to describe the methods for preparing the fibers, meshes, and composite devices with autologous, allogenic and/or xenogenic tissues, and to illustrate the strength retention of the fibers upon implantation.
Example 1
Melt Extrusion of PHA4400 to Produce Monofilament Fibers
[0033] PHA4400 (Tepha, Inc., Cambridge, Mass.) (Mw 575K) was ground into small pieces using a Fritsch cutting mill (Pulversette 15, 10 mm bottom sieve) and dried under vacuum overnight prior to melt processing. Monofilament fibers of PHA4400 were melt extruded using an AJA (Alex James Associates, Greer, S.C.) ¾″ single screw extruder (24:1 L:D, 3:1 compression) equipped with a Zenith type metering pump (0.16 cc/rev) and a die with a single hole spinnerette (0.026″, 2:1 L:D). The 4 heating zones of the extruder were set at 140°, 190°, 200° and 205° C. The extruder was set up with a 15 ft drop zone, 48″ air quench zone (10° C.), a guide roll, three winders and a pickup. The fiber was oriented in-line with extrusion by drawing it in a multi-stage process to provide fiber with high tensile strength and a reduced extension to break. The fiber was drawn in-line to stretch ratios of 6 to 11×. A spin finish (Goulston, Lurol PT-6A) was dissolved in iso-propanol at 10 vol/vol % and applied to the fiber before the first roll to act as a lubricant and protect the fiber during downstream processing. A series of fibers of different sizes were produced by varying the extrusion conditions (metering pump speed) and drawing conditions (draw ratio). Tensile mechanical properties of the melt extruded fibers were determined using a universal mechanical tester, and results are shown in Table 1. As is evident, the tensile strength of the oriented PHA4400 fiber is comparable to 450-560 MPa reported for the commercial suture fiber, PDS™, Chu, C. C., et al. Wound Closure Biomaterials and Devices , CRC Press (1997). The weight average molecular weight (Mw) of the fibers was determined by gel permeation chromatography (GPC) and is also shown in Table 1.
[0000]
TABLE 1
Properties of melt extruded PHA4400 monofilament.
Tensile
Elongation
Draw
Diameter
Load at
Strength
to Break
Mw**
Sample
Ratio
(μm)
break (g)
(MPa)
(%)
(K)
1
5.95
125
533
426
107
338
2
5.95
113
274
268
126
293
3
5.95
82
68
126
34
278
4
5.95
128
389
297
134
302
5
6.00
134
426
296
118
313
6
10.75
120
569
494
32
348
7
10.75
120
446
387
29
356
10*
10.75
217
1304
346
70
395
11*
5.95
190
1291
447
135
396
*Note: Samples 10 and 11 were spun through a larger spinnerette (0.045″, 2:1 L:D).
**Note Mw of starting polymer was 575 K.
Example 2
Strength Retention and Biocompatibility of PHA4400 Monofilament Fibers
[0034] An implantation study to determine the strength retention of PHA4400 fibers was undertaken in a rabbit model. Sample 10 (shown in Table 1) was selected for these studies because the fiber had an elongation to break of 70% and tensile strength of 346 MPa (60,000 psi) that is comparable to commercial monofilament absorbable sutures. Prior to implantation the fiber was sterilized using cold ethylene oxide gas (40° C., ethylene oxide pressure of 13.7 INHGA, humidity of 1.7 INHGA, dwell time 4 hr, and aeration time 10 hr). A small amount of fiber shrinkage (2%) was noted to result during the sterilization process. A commercial monofilament absorbable suture material, PDS™, was used as a control.
[0035] Under sterile conditions, the sterilized sutures were placed perpendicular to the dorsal midline of the rabbit. After making a small incision, a large hemostat was introduced through the incision into the subcutaneous tissue and tunneled approximately 9 inches into the subcutis layer. The PHA4400 and control (3/0 PDS™) suture fibers were threaded individually through separate surgically created implant areas and left in place. The incisions were closed with tissue glue. A total of four test and four control samples were implanted in each rabbit. Animals were maintained for periods of 1, 4, 8, 12, 16 and 26 weeks (2 rabbits per time point) and were observed daily to ensure proper healing of the implant sites. At the end of the appropriate time points, the animals were weighed and euthanized by an injectable barbituate. Tissue sections containing the implanted sutures were excised from the animals. One test and one control sample were fixed in formalin and retained for histological analysis of the tissue surrounding the suture implants. The remaining three samples from each group were cleaned of tissue, wrapped in sterile, saline soaked gauze and returned on the day of explantation for further analysis. Suture samples were further cleaned of residual tissue and dried.
[0036] In parallel with the in vivo degradation study, an in vitro degradation study was conducted to generate comparative data. Sterilized PHA4400 monofilament fibers, identical with those used in the implantation study, were incubated in Dulbeco's phosphate buffered saline (pH 7.4, 37° C.) containing sodium azide (0.05%) as a preservative. Six control PHA4400 sutures per time point were enclosed in sterile polyethylene sample bags and removed at the same time as each of the implant samples. The in vivo and in vitro samples were processed identically.
Strength Retention
[0037] The explanted suture samples were subject to tensile testing according to the procedure of ASTM D2256-97. The results of this tensile testing are shown in FIG. 3 . As can be seen, the PHA4400 and PDS™ control sutures had very comparable starting tensile strengths (60,000 psi). As expected, the PDS™ control sutures maintained 50% of their initial tensile strength until approximately the 6 th week. In contrast, the implanted PHA4400 sutures retained approximately 30% of their tensile strength through the 26 th week. A comparison of the tensile mechanical properties of PHA4400 and commercially available monofilament sutures is shown in FIG. 4 .
[0038] Unlike the implanted suture, the PHA4400 in vitro control suture showed a more gradual loss of strength during the entire 26-week degradation study, retaining 80% of its original strength. This result demonstrates the mechanical stability of the polymeric material to simple hydrolysis.
Molecular Weight and Mass Loss
[0039] In addition to the strength retention of the PHA4400 suture fibers, the Mw of the PHA4400 samples were analyzed by GPC. As shown in FIG. 5 , the Mw of the implanted and control PHA4400 sutures decreased gradually during the course of the degradation study to approximately 43% of their original Mw at 26 weeks. Additionally, there does not appear to be a significant difference between the Mw of the implanted and the in vitro control PHA4400 sutures. This result shows that the hydrolytic stability of the implanted sample is very similar to the in vitro control.
[0040] In order to determine the mass loss of the samples over time, the mass and length of the PHA4400 sutures (in vitro and in vivo) were determined and plotted as a function of degradation time. The ratio of mass to length of the PHA4400 samples (implanted and buffer control) is plotted vs. degradation time and shown in FIG. 6 . The mass/length ratio was determined rather than just the mass of the sample, because this ratio normalizes for samples that were cut during implantation or that break during harvest. As can be seen in this figure, the implanted sutures appear to loose mass more rapidly than the in vitro controls. This data shows that the implanted samples lost mass more rapidly than the in vitro control samples and suggests that surface degradation is occurring in vivo.
Tissue Reaction
[0041] The tissue surrounding the implanted PHA4400 and PDS™ control sutures was analyzed for the tissue reaction to the implanted articles through the 26-week time point. Formalin fixed tissue samples (PHA4400 and PDS™ control) from each test animal were sectioned and graded by a board certified veterinarian for the following: inflammation, fibrosis, hemorrhage, necrosis, degeneration, foreign debris and relative size of involved area.
[0042] Hisotopathological evaluation indicated that the finding at the PDS™ control and PHA4400 sites were similar and there were no significant indications of a local toxic effect in either the control or the test sites.
Example 3
Knitted Mesh of PHA4400 Monofilament Fibers with Prolonged Strength Retention
[0043] A warp knitted mesh of PHA4400 was produced from 100 μm diameter oriented monofilament PHA4400 fiber produced as described in Example 1. A warp knit type of construction is desirable as an implant because it can be cut by the surgeon and will not readily unravel. The mesh was fabricated using fiber of 100 μm monofilament PHA4400, tensile strength 92,000 psi, and an elongation to break of 77%. Fabric construction was as follows: Mach #30 Raschel Knit 36 gauge fabric, 150 ends, 16 courses, 40 stitches per inch, using 18 needles per inch. Specifications for the finished fabric were: Weight: 58 g/m 2 (1.72 oz/sq. yard), Thickness: 0.29 mm.
Example 4
Extrusion of Suture Fibers of a Copolymer of Glycolate and 4-hydroxybutyrate (PHA4422)
[0044] PHA4422 containing 5% glycolic acid comonomer (Mw 305,000 by GPC) was melt extruded into a fiber and converted to a suture as follows. The polymer was prepared by milling the bulk polymer into approximately 1 mm sized particles using a P-15 laboratory cutting mill (Fritsch, Germany) dried in a vacuum desicator. The polymer was extruded using an AJA ⅝″ single screw extruder (Alex James and Associates) with a single-hole spinneret (0.040″, 2:1 L/D). The extruder had five separate temperature zones that were set to 120, 154, 155, 160 and 160° C. from the inlet to the outlet, with a gear pump at the outlet. The total residence time in the extruder was estimated at 9 minutes.
[0045] After extrusion there was a 10 ft drop zone through air before a quenching water bath (5° C.). Following the quench bath, three winders were used to collect the fiber. A first winder was set for a speed of about 2.5 meters per minute. The bath length was about 3-4 ft and the residence time for the fiber in the bath was estimated at about 30 seconds. Crystallization of the fiber occurred before the first winder. Two additional winders (17.5 and 19.5 meters/minute) extended the fiber about 8 times (8× draw). A take up unit was used with only slight tension. Varying the polymer extrusion rate while keeping the downstream orientation and take up rates the same produced fibers of different diameters. Initially, the extruder was set at a gear pump rate of 7, and then successively slowed resulting in fibers of approximately 375, 275 and 200 μm diameter, see Table 2.
[0046] Suture needles were attached to each of the different diameter fibers and the sutures were packaged for sterilization. Tensile strength (straight and knot pull) was determined for representative samples of the sutures, see Table 2.
[0000]
TABLE 2
Physical characterization of sutures prepared by melt extrusion
of PHA4422 (5% glycolic acid comonomer, Mw 300K).
Fiber
Corresponding
Tensile Strength
Elongation
Tensile Strength
Elongation
diameter
USP size
Straight Pull
Straight Pull
Knot Pull
Knot Pull
(μm)
approx.
(lbf)
(%)
(lbf)
(in)
375 +/− 6
0
9.2 +/− 1.6
128 +/− 33
4.6 +/− 0.4
51 +/− 4.2
256 +/− 1
2/0
5.3 +/− 0.3
65 +/− 13
3.8 +/− 0.8
49 +/− 18
199 +/− 5
4/0
3.0 +/− 0.3
130 +/− 24
1.6 +/− 0.3
44 +/− 15
Example 5
Monofilament Fiber with Peak Tensile Stress of Greater that 70 kg/mm 2
[0047] Melt spinning of Poly-4-hydroxybutyrate “PHA4400” polymer has been extremely difficult to accomplish due to melt flow instability and tackiness of resulting fiber. Melt leaving the spinning die exhibited periodic diameter fluctuation and helical structure. These flow irregularities are known as melt fracture or “elastic turbulence” and are generated while the melt is entering and passing through spinneret hole. The reason for such flow irregularities is very high viscosity of the viscoelastic melt and a very high elastic function at the exiting point of spinneret capillary.
[0048] The low glass transition temperature of about −50° C., and the low tendency to crystallize of this polymer explain the stickiness of the fibers. In addition to that, the orientation, which was generated during melt spinning, relaxed after a very short time so that the fibers offered a low tenacity for further drawing.
[0049] This example illustrates our ability to overcome the above processing problems and produce high strength fiber. PHA4400 polymer was dried to less than 0.01% moisture. Dried pellets of the PHA4400 were fed to an extruder barrel under a blanket of nitrogen. Barrel temperatures zones were kept at 100° C. feed, 150° C. transition and 200° C. metering. Molten polymer passed through a heated block to a metering pump then extruded from a die with a single hole spinneret. The block, metering pump and the die were kept at 220° C. temperature. Pump discharge pressure was kept below 1000 psi by control of temperatures, and the speed of the metering pump. Spun extrudate filament was free from all melt irregularities. The extrudate was allowed dwell time to crystallize after which further multi stage drawing was possible to increase crystal orientation and gain strength. The fiber was then heat treated and rolled on a winding spool. Properties of the ensuing fiber are shown in Table 3.
[0000]
TABLE 3
Physical characterization of fibers
prepared by melt spinning of PHA4400
Fiber
Fiber
Peak
Min Break
Min Break
Min Break
Min Diam.
Max Diam.
Load
Strength
Strength
Strength
microns
microns
kgf
kgf/mm{circumflex over ( )}2
PSI
MPa
0.070
0.089
0.46
73.98
1.05E+05
726
0.129
0.178
1.80
72.37
1.03E+05
710
0.256
0.305
5.50
75.32
1.07E+05
739
0.421
0.470
13.00
74.97
1.07E+05
735
0.523
0.622
22.70
74.74
1.06E+05
733
“Diam” means Diameter
Example 6
Monofilament Fibers with Prolonged In Vivo Strength Retention
[0050] The PHA4400 monofilaments prepared as in Example 5 were sterilized using cold ethylene oxide gas (40° C., ethylene oxide pressure of 13.7 INHGA, humidity of 1.7 INHGA, dwell time 4 hr, and aeration time 10 hr).
[0051] Under sterile conditions, the sterilized monofilament fibers were placed perpendicular to the dorsal midline of the rabbit. After making a small incision, a large hemostat was introduced through the incision into the subcutaneous tissue and tunneled approximately 9 inches into the subcutis layer. The PHA4400 fibers were threaded individually through separate surgically created implant areas and left in place. A total of four test and four control samples were implanted in each rabbit. Animals were maintained for a period of 2 weeks (2 rabbits) and were observed daily to ensure proper healing of the implant sites. At the end of the appropriate time points, the animals were weighed and euthanized. Tissue sections containing the implanted sutures were excised from the animals. Samples were cleaned of tissue, wrapped in sterile, saline soaked gauze and returned on the day of explantation for further analysis. Suture samples were further cleaned of residual tissue and dried. Tensile strength was determined on a universal testing machine. The tensile breaking load of the explanted fiber after 2 weeks implantation was found to be 8.5 lbf peak load, which is 87% of that of the starting fiber (9.8 lbf). Thus these fibers demonstrated a higher strength retention in vivo (87% at 2 weeks) when compared to the fibers in Example 2, FIG. 3 (50% at 2 weeks).
Example 7
Multifilament Yarn
[0052] Fiber spinning was carried out in the same manner as example 5 except with the die having a multi hole spinneret (20 holes×0.0065 inches). Extrudate yarn was allowed time to crystallize, and a super cooled stream of gaseous media/liquid mist perpendicular to the fiber axis was introduced. A subzero bath was also used and proved a suitable substitute for the gaseous media. The resulting filaments were further processed through cold and heated godets, and the filaments could be oriented and heat set. Yarn tenacity of greater than 3.5 gpd (gram per denier) with 30% elongation was obtained. Representative data for the multifilament yarns is shown in Table 4.
[0000]
TABLE 4
Tensile properties for PHA4400 multifilament yarns.
Denier per
Peak Load
Strain at
Tenacity
Sample
filament
Kg
break (%)
g/denier
1
33.8
2.43
97
3.6
2
27.1
1.69
114
3.1
3
23.7
1.92
58
4.1
4
16.2
1.12
113
3.4
5
12.8
0.99
107
3.9
6
10.3
0.71
74
3.5
Example 8
Knitted Fabric from a Multifilament Yarn
[0053] A multifilament yarn was knitted into a tube using a single feed, circular weft knitting machine (Lamb Knitting Co., model ST3A/ZA). The width of the flat tube was approximately 9 mm. The yarn knitted very well without evidence of fiber breakage even without the addition of a spin finish as a lubricant. After cleaning and sterilization, the knitted tube appears well suited for use as an absorbable medical fabric.
Example 9
Absorbable Polymeric Support Structure for Biological Tissue Implant
[0054] PHA4400 fiber woven, knitted or braided into semi rigid support tubes or PHA4400 polymer directly extruded into support tubes can be prepared with an inner diameter closely matching that of a biological substrate implant (e.g. autologous, allogenic and/or xenogenic tissue). The biological implant can be inserted into the support tube, and may optionally be secured in place, for example, by suturing, prior to implantation. The addition of the support tube provides improved strength, modulus, and can make implantation easier. Similarly sheets of extruded film, woven, non-woven or knitted fabric may be rolled over a biological tissue implant and the fabric ends may be tied, sutured or glued to maintain a semi-rigid construct over the biological implant.
[0055] A woven tube was produced from 0.300 mm diameter monofilament PHA4400 fiber extruded as described in Example 5. Using circular weaving equipment a 10 mm inside diameter tube was produced. The tube construction allowed insertion of an implant biological substrate and provided enough stiffness to position and suture an otherwise flaccid biological implant. | Absorbable polyester fibers, braids, and surgical meshes with prolonged strength retention have been developed. These devices are preferably derived from biocompatible copolymers or homopolymers of 4-hydroxybutyrate. These devices provide a wider range of in vivo strength retention properties than are currently available, and could offer additional benefits such as anti-adhesion properties, reduced risks of infection or other post-operative problems resulting from absorption and eventual elimination of the device, and competitive cost. The devices may also be particularly suitable for use in pediatric populations where their absorption should not hinder growth, and provide in all patient populations wound healing with long-term mechanical stability. The devices may additionally be combined with autologous, allogenic and/or xenogenic tissues to provide implants with improved mechanical, biological and handling properties. | 1 |
FIELD OF THE INVENTION
The present invention relates to a method for protecting a control device against manipulation, a method for executing cryptographic functions in a control device, and a control device for executing cryptographic functions.
BACKGROUND INFORMATION
Frequently, embedded systems are attacked in order to manipulate them, for example, in order to increase the performance of an internal combustion engine by exchanging programs or data. Algorithms and methods have therefore been developed to protect embedded systems (ES) from being manipulated by third parties unauthorized to do so. To this end, cryptographic functions, for example, that are based on symmetric or asymmetric sets of keys are implemented in digital circuits in order to increase security. The use of OTP (one-time programmable) and ROM memory areas or switches (“fuses”) in digital circuits, such as, for example, microcontrollers, is also known.
A control device and method are described, for example, in German Patent No. DE 10131576. In the described microprocessor system and method, a check program is provided in a read-only memory, which check program is in a position to check the content of a rewritable memory for impermissible modifications. In the method, the central processing unit is first put in a position to carry out input and output operations that are necessary for the processing of instructions. After executing such a minimum program, or a boot routine of that kind, a code word, such as a check sum, is determined from at least a portion of the data in a rewritable memory.
A code word may be determined using more or less complicated mathematical encryption methods that do not permit an unauthorized person without exact knowledge of the encryption algorithm to determine the code word from the content of the rewritable memory.
Then the system compares the code word that was determined in this way to a comparison code word that is saved, for example, in the rewritable memory. If the code word and the comparison code word match each other, the program continues. If the code word and the comparison code word do not match, further operation of the microprocessor system is blocked. An authorized user who wants to modify the content of the rewritable memory thus determines, with the encryption algorithm that is known to him alone, a comparison code word from the program to be stored in the memory and then stores this in the memory. After executing the check program, the microprocessor system will then operate properly. An unauthorized modification of the memory content of the rewritable memory fails due to the fact that the encryption algorithm is not known, so that it is not possible to store a correct comparison code word in the rewritable memory. The check program recognizes that the code word and the comparison code word are different and blocks the microprocessor system from processing additional tasks.
SUMMARY OF THE INVENTION
The present invention relates to a method for protecting a control device from being manipulated in which a number of sets of keys is provided for decoding data via cryptographic functions, a key switch being additionally provided via which the cryptographic functions access sets of keys.
To increase security, the present invention thus provides that a key switch enables an assignment of cryptographic functions to corresponding sets of keys, the sets of keys being encapsulated and thereby protected against manipulation. The present invention thus makes it possible to hinder or prevent attacks on sets of keys that are in use.
Increasingly, for various reasons, digital circuits/microcontrollers provided with a low memory capacity or even having no program memory at all are being used in embedded systems (ES). In principle, systems having such digital circuits/microcontrollers have weak points from the perspective of protection against manipulation. For motor vehicles, the performance of an internal combustion engine, for example, could be increased by exchanging programs or data in a rewritable memory. This performance improvement through manipulation of the control program or the data may, however, result in an overloading of the internal combustion engine and ultimately even lead to a defect in the internal combustion engine.
Using the control device and the method of the present invention, it is possible to implement a secured but still configurable key storage in an ES and thereby to increase the protection against manipulation.
The present invention also relates to a method for executing cryptographic functions in a control device in which the cryptographic functions use assigned sets of keys to decode data, the assignment of the cryptographic functions to the assigned set of keys in each instance being performed via a provided key switch.
The present invention furthermore relates to a control device, which has a first memory area for recording sets of keys for decoding data. The control device has a second memory area for recording a key switch that enables an assignment of cryptographic functions to corresponding sets of keys.
In the control device and method according to the present invention, the sets of keys are encapsulated and thereby protected against manipulation. It is possible to configure various sets of keys for different applications. For reasons of manipulation protection, this configuration is allowed only once, for example, in the production of the ES. To encapsulate the sets of keys, the control device of the present invention has a key switch that enables an assignment of cryptographic functions to corresponding sets of keys.
The key switch is stored in an OTP memory area so that the key switch may no longer be modified. The key switch makes it possible, depending on the programmed configuration of the sets of keys (for example, through OTP memory cells, so-called “fuses”), to refer to different memory locations when accessing the key array.
A ROM key memory area may be populated only by the manufacturer of the digital circuit/microcontroller. Typically, multiple memory locations as well as one identification exist.
An internal or external program memory may, among other things, include the cryptographic functions that access the sets of keys via the key switch. To increase protection, these may be stored in the internal flash and, in the ideal case, be stored there in a ROM.
Each cryptographic function may access the sets of keys transparently via the key switches. Different sets of keys are provided in order to be able to configure another sentence, for example, in the case of a compromised set of keys, without having to modify the ROM of the key memory.
The position of the key switch is set in the OTP key configuration, for example, during the production of the ES, and after this can never again be modified (for example, by an attacker).
The cryptographic functions check, via the existence of the key switch as well as the identification information in the key array or the key field, whether the digital circuit/microcontroller even offers this feature in the correct version. If not, then the suspicion exists that an attacker exchanged the digital circuit/microcontroller with a module not having these functions or for another (old) set of keys.
The present invention furthermore relates to a computer program having program code means for executing one of the described methods, and a computer program product having these code means stored on a computer-readable medium.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic representation of a control device according to the present invention in accordance with a preferred specific embodiment.
FIG. 2 shows a method according to the present invention in accordance with a preferred specific embodiment in a flow chart.
DETAILED DESCRIPTION
FIG. 1 shows a control device 11 , which includes a digital circuit/microcontroller 10 , a key switch 12 , a key memory 14 , and an internal program memory 16 . An external memory area 18 is additionally shown. In different specific embodiments of the present invention, control device 10 has an internal or external program memory 16 , 18 or an internal and external program memory 16 , 18 .
Key memory 14 is a ROM memory area. Different sets of keys 24 , 26 are stored in this memory area 14 . A piece of identification information 22 also exists.
ROM key memory area 14 may be populated only by the manufacturer of control device 10 , so that sets of keys 24 , 26 may no longer be manipulated at a later point in time. It is possible to configure different sets of keys 24 , 26 for different applications. Different sets of keys 24 , 26 are provided in order to be able to configure another key, for example, in the case of a compromised set of keys 24 , 26 , without having to modify the ROM of key memory 14 .
Key switch 12 enables an assignment of cryptographic functions to corresponding sets of keys 24 , 26 and may be stored in an OTP memory area so that it may not be manipulated. Depending on the programmed configuration of sets of keys 24 , 26 , key switch 12 makes it possible to refer to different memory locations when accessing the key array.
Internal and external program memories 16 , 18 include among other things cryptographic functions 28 , 30 , which access sets of keys 24 , 26 via key switch 12 . To increase protection, these may be located in the flash, and in the ideal case, be located there as ROM.
Each cryptographic function 28 , 30 may transparently access sets of keys 24 , 26 via key switch 12 , in order to decode the cryptographic functions 28 , 30 .
Cryptographic functions 28 , 30 check, via the existence of key switch 12 as well as identification information 22 in the key array, whether control device 10 even offers this feature or characteristic in the correct version. If not, then the suspicion exists that an attacker exchanged control device 10 with a module not having these functions or having other (old) sets of keys.
FIG. 2 shows a method in which for the execution of a cryptographic function in a control device, cryptographic function 28 and/or 30 first decodes data 32 using assigned set of keys 14 , the assignment of cryptographic functions 28 , 30 to the assigned sets of keys taking place via a provided key switch 12 .
Cryptographic function 28 may be stored in an internal ROM/OTP/Flash or RAM program memory. To increase protection, these are located in the internal flash, and in the ideal case, are located there as ROM.
Cryptographic function 30 may also be stored in an external program memory. In this example, an OTP memory area is provided for recording key switch 12 . | A method for protecting a control device against manipulation in which a number of set of keys for decoding cryptographic functions is provided, a key switch being additionally provided, via which the cryptographic functions access sets of keys. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a protective element particularly for shorts for sports use, such as for example for cycling, motorcycling, and gymnastic activity such as spinning and triathlon.
[0002] Currently, in cycling it is known to use shorts, made of optionally partially elasticated material, which cling to the body considerably and are usually worn without underwear.
[0003] The main problem for the athlete is that during races or practice the crotch is subjected to continuous stresses, since this part of the body is continuously in contact with the saddle and is therefore subjected to all the jolts produced by the unevenness of the terrain and by the vibrations transmitted by the bicycle frame.
[0004] Accordingly, localized reddenings are produced which can degenerate into cuts or blisters that make it difficult, if not impossible, to perform sports practice.
[0005] As a partial solution to these drawbacks, it is known to use shorts inside which padding, constituted by a cloth of suitable thickness made of textile material, is sewn internally at the crotch.
[0006] However, this solution is not ideal, since although the thickness of the padding can provide relief initially, it has been found that it tends to overheat the crotch and especially that also due to sweating there is continuous sliding between the crotch and the padding, which very soon cancels out the initial benefits.
[0007] Moreover, it has been found that the crotch rests on the padding, and the padding rests on the saddle, so as to form compression concentration regions that depend on the stresses applied during sports practice, and this entails even the onset of aches.
[0008] As a partial solution to these drawbacks, it is also known to provide shorts with which a bottom is associated by sewing at the crotch region, such bottom having a plurality of chambers arranged laterally to an axis that is longitudinal with respect to the saddle, the chambers being mutually separate and forming diversified contact regions for the crotch.
[0009] Although the chambers solve part of the drawbacks mentioned above, this solution and the preceding ones have the drawback that the padding or bottom are made of materials that are substantially rigid or scarcely elastic in a percentage that varies between approximately 0 and 2%, and this renders ineffective any small elastic deformation of the fabric that constitutes the shorts.
[0010] This fact limits considerably the freedom of movement of the body; moreover, the larger the padding, the thicker it becomes, further increasing overall rigidity and weight and thus preventing movements even more.
[0011] Moreover, a “diaper effect” is produced: when the cyclist dismounts from the bicycle and walks normally, he is thus further hindered in his movements by the presence of the padding or bottom.
[0012] Reducing the padding can provide greater freedom of movement, but has a considerable negative effect on the ability to protect from impacts and vibrations on the saddle.
[0013] Moreover, the use of padding or bottoms has been found to be subject, during cycling, to the formation of creases, owing to the arc-like shape of the crotch, and these creases produce further regions of discomfort both longitudinally and transversely to the crotch region.
[0014] Finally, it is noted that the use of padding in known bottoms affects the entire extension of the product, and this entails a further increase of the mentioned “diaper effect”.
[0015] In all of the known background art, the padding is in fact present over the entire extension of the product; even in the method that uses differentiated thicknesses, the flat padding part is obtained by compressing the padding, which thus affects also the apparently flat portions of the bottom.
SUMMARY OF THE INVENTION
[0016] The aim of the present invention is to eliminate the drawbacks of the cited prior art, by providing a protective element that allows to achieve optimum comfort at the crotch and at the same time great freedom of movement both on the saddle and off the saddle together with an overall light weight of the shorts, thus avoiding the mentioned “diaper effect”.
[0017] Within this aim, an object of the invention is to provide a protective element that allows to achieve greater comfort for the user while maintaining light weight and/or low thickness characteristics.
[0018] Another important object is to provide a protective element that allows optimum adaptation to the anatomical shape of the male or female user once the shorts have been put on.
[0019] Another important object is to provide a protective element that can be used in a distinct manner even for users having different clothing sizes.
[0020] Another object is to provide a protective element that associates with the preceding characteristics that of having low costs and of being structurally simple, said invention being reliable and safe in use.
[0021] This aim and these and other objects that will become better apparent hereinafter are achieved by a protective element, particularly for shorts, characterized in that it is constituted by a support that has, in an upper region, regions that protrude differently and, in a lower region, a layer of material that can be coupled detachably by simple resting on said shorts.
[0022] Advantageously, the support has grip means for the user which are suitable to simplify removal and/or positioning of said support on the shorts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Further characteristics and advantages of the invention will become better apparent from the following detailed description of a particular embodiment thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
[0024] [0024]FIG. 1 is a plan view of the protective element;
[0025] [0025]FIG. 2 is a schematic perspective view of a pair of shorts, illustrating the protective element associated therewith;
[0026] [0026]FIG. 3 is a front view of the shorts, illustrating the presence of a tape;
[0027] [0027]FIG. 4 is a sectional view, taken along the line IV-IV of FIG. 1; FIG. 5 is a sectional view, taken along the line V-V of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] With reference to the figures, the reference numeral 1 designates a protective element, which is used particularly at the crotch region 2 of shorts 3 , for example cycling shorts.
[0029] The protective element is constituted by a support 4 , which has a lower surface 5 made of a material having a non-smooth, highly porous neoprene base; this material interacts, by contact, with the shorts, which advantageously but not necessarily have very fine grooves that allow to facilitate strong grip between the two parts.
[0030] It is therefore sufficient for the user to place the support against the shorts, simply adapting its position according to his or her anatomical shape.
[0031] The support 4 further has an upper surface 6 on which differentiated relief regions 7 are provided by thermoforming so as to further increase user comfort.
[0032] There are also grip means 8 for the user which are suitable to simplify the removal or positioning of the support with respect to said shorts; such means are constituted by a tab 9 , which protrudes frontally with respect to the support 2 in its front region.
[0033] Other grip means are constituted by a tape 10 , which protrudes inside the shorts in the crotch region 2 .
[0034] The tape has an opening 11 that allows passage and engagement of the support to the shorts.
[0035] The tape is advantageously rectangular and also elastic and acts as a sort of coupling guide, which thus allows to insert the support inside it, ensuring greater stability thereof and simultaneously ensuring that it remains at the center of the fork while leaving it free to be positioned at will by the user.
[0036] It has thus been observed that the invention has achieved the intended aim and objects, a protective element having been obtained that can be applied to shorts rapidly and easily for the user, the protective element adapting in an optimum manner to the crotch during sports practice or being easily removable during walking or during sports practice.
[0037] Moreover, the protective element can be positioned perfectly, with respect to the shorts, by the male or female user by virtue of the temporary mechanical connection provided by simple mutual resting contact.
[0038] Moreover, the use of optional shorts without lateral seams increases user comfort, also by way of the presence of the differentiated relief regions: the use of yarns with a higher elasticity modulus allows optimum adaptation to the body, in a manner that is far more effective than conventional products, regardless of adaptability to a clothing size.
[0039] The supports of the protective element are produced by thermoforming and/or high frequency technology, which allow to form the differentiated relief regions in order to better protect the more delicate parts of the body in contact with the saddle.
[0040] These supports adhere naturally to the shorts without requiring uncomfortable stitched seams, by way of fabrics that are mechanically compatible with the shorts, and it is sufficient to position them as required and, if necessary, move them freely forward or backward, to the right or to the left, without limitations.
[0041] These supports can therefore be washed separately and be removed at any time and can therefore be used with any type of shorts.
[0042] Advantageously, the supports are made of a temperature-regulating microfiber covering, which ensures antibacterial protection and facilitates rapid evaporation of perspiration.
[0043] Moreover, removability allows to solve any drawbacks due to possible overheating of the crotch.
[0044] Further, removability allows the user to change, during sports practice, the type of protective element according to the sport being practiced, such as for example on-road or off-road use.
[0045] Moreover, the particular shape of the protective element, whose surface practically affects only the region of contact with the crotch, has dimensions and a volume that minimize user discomfort, for example during walking.
[0046] The materials used may of course be the most pertinent according to specific requirements.
[0047] The disclosures in Italian Patent Application No. TV2001A000116 from which this application claims priority are incorporated herein by reference. | A protective element, particularly for shorts, for example for cycling, comprising a support that has, in an upper region, regions that protrude differently and, in a lower region, a layer of material that can be coupled detachably by simple resting on the shorts. | 0 |
This application is a continuation-in-part of my commonly assigned, co-pending U.S. Pat. application Ser. No. 07/957,160 filed Oct. 7, 1992, now abandoned.
FIELD OF INVENTION
The invention relates to the art of papermaking. In particular, the invention relates to a paper sizing process which produces paper that is uniquely suitable for use in the aseptic packaging of foods, beverages, and the like.
BACKGROUND OF THE INVENTION
Sizing is a term used in the papermaking art to describe processes which reduce the water absorbency of a paper sheet. Functionally, a sized paper sheet resists wicking by water-based ink applied to the sheet surface. Sizing also improves the dimensional stability of a sheet by inhibiting absorption of atmospheric moisture.
Sizing effectiveness in paper is measured by either or both of two standardized edge-wicking tests wherein the face surfaces of a paper sample are protected by waterproof tape and the exposed edge sample immersed in a penetrating solution for a measured time interval. Afterward, the sample is weighed and the value obtained is compared with the preimmersion sample weight to determine the quantity of solution absorbed by the sample. This absorbed quantity is then normalized by the edge area of the sample
One such edge-wicking test utilizes a 35% solution of hydrogen peroxide as the penetrating solution. The other such test subjects the sample to a 1% solution of lactic acid. Depending on the utility of the paper product, one test may be more significant than the other. For example, paper used for milk containers must have a low capacity for lactic acid edge-wicking.
Historically, sizing agents have been formulated from a mixture of about 1% per ton of dry pulp natural, anionic rosin, and about 1.5 to 2% alum (Al 2 SO 4 ) 3 . In an acidic papermachine headbox furnish of about 4.0 to 4.5 pH, these compounds coprecipitate onto the cellulose fiber to be subsequently stabilized by drying to form a hydrophobic coating. This process of blending the size formulation with the headbox furnish is characterized as "internal sizing" due to the fact that the sizing is distributed homogeneously throughout the thickness of a paper web formed from such headbox furnish.
Although natural anionic rosin sized paper formed from an acidic headbox furnish has good hydrogen peroxide holdout, the lactic acid holdout is normally poor.
Supplemental to the internal size, paper manufactured for converted utility as a liquid or beverage container is frequently "surface sized" with a solution of glue and/or starch. In such cases, the size solution is coated onto the surface of a dry web as the web runs into a pond of the solution confined between the web surface and a roll or doctor blade surface. When applied to both web surfaces simultaneously, respective ponds are confined between opposite web surfaces and respective members of a roll nip pair. This common arrangement is characterized as a "size press."
More recently, synthetic sizing agents such as alkyl ketene dimer, stearic anhydride, and alkenyl succinic have been developed to form true chemical covalent bonds with cellulose rather than the ionic or polar bonds of natural size. Most prevalent of these synthetic size compounds is alkyl ketene dimer (AKD).
Once cured, synthetic size is more stable against water, acids, and alkalis. Consequently, synthetically sized paper has good lactic acid holdout but normally poor hydrogen peroxide holdout. The process solution of synthetic size is acid/alkali sensitive, however, and, when used as an internal size, must be blended to a substantially neutral 6.5 to 8.5 pH headbox furnish. This circumstance gives rise to the trade characterization of "neutral sizing." Synthetic size has also been used as a surface size constituent; following a synthetic or "neutral" internal size treatment, however.
Although synthetic size may be blended with cationic resins in an internal sizing process to improve hydrogen peroxide holdout, the necessary neutral pH headbox solution limits available brightness. Distinctly acid pulps are required for paper of the greatest brightness value.
It is, therefore, an object of the present invention to provide a paper sizing process by which high brightness values, low bacteriological contamination, and good holdout against hydrogen peroxide and lactic acid may be obtained.
SUMMARY OF THE INVENTION
This object and others of the invention to be hereafter described are accomplished by a process that includes both internal and surface sizing.
As a first step in the present process, headbox furnish is blended with an internal size formulation comprising about 1% (of the dry pulp weight) anionic rosin and about 1.3 to 2.6% alum. The pH of the furnish is adjusted to a range of about 4.0 to 4.5. Thus formed, the resulting web is dried to less than 10% moisture content, preferably about 2% moisture content, and surface sized. Such surface size is formulated with about 0.025 to 0.050% of the dry pulp weight being AKD and with sufficient sodium bicarbonate added (usually about 0.125 to 0.150% sodium bicarbonate) to both neutralize any unreacted alum present near the surface of the internally sized web and to assure the resulting formation of paper having a water extractable pH in the range of about 4.0 to below 6.0. A conventional starch mixture may also be included with the surface size formulation. To set the surface size and complete the web, subsequent drying reduces the web moisture again to 7% or less.
DESCRIPTION OF THE PREFERRED EMBODIMENT
To confirm and test the present invention effectiveness, six paper production runs were scheduled over a six month operating period for the same papermachine using the same fiber furnish. Paper was produced using the present invention size formulation and also a size formulation representative of prior art practice as a control or reference sample. These formulations are comparatively described in Table I below.
TABLE I______________________________________SIZE CONTROLFORMULATION SAMPLE INVENTION______________________________________Internal SizingAnionic Rosin 0 1%Alum 0.4% 1.3-2.6%Polyamide resin 0.25% 0AKD 0.4-0.5% 0Sodium Bicarbonate 150 ppm alkalinity 0pH 7.0 4.0-4.5Surface SizingAKD 0.025-0.050% 0.025-0.050%Sodium Bicarbonate 0.045-0.075% 0.125-0.150%Starch Mixture Conventional ConventionalpH 7.0 7.0______________________________________
In the case of webs internally sized with synthetics (such as the Control Sample in Table I), alum is added to the internal size formulation to improve web runnability on the papermachine by inhibiting such fiber from sticking to the papermachine roll surfaces. When alum is added to a synthetic internal sizing system, the alum acidity must be neutralized by a corresponding amount of alkaline material (such as sodium hydroxide, sodium bicarbonate, potassium bicarbonate, and the like). Additional alkaline material may be combined with the subsequently applied synthetic surface size to neutralize that mixture with starch.
Alum is also blended with the headbox fiber furnish in many mill circumstances for the purpose of pH control prior to and independent of an anionic rosin addition. Such practice consequently influences the quantity of alum blended with such a headbox furnish for the purpose of internal size rosin precipitation and the degree of internally sized web acidity.
Moreover, excess alum is frequently added to the headbox formulation of naturally sized paper furnish to assure complete rosin precipitation. As a result paper webs internally sized with anionic rosin are normally strongly acidic. Synthetic size (e.g. AKD) is not normally compatible with strongly acidic webs. In practice of the present invention, however, the incompatible circumstances of a pH neutral synthetic surface size applied to a strongly acidic web are reconciled by the addition of sufficient sodium bicarbonate to the synthetic surface size mixture to both neutralize any unreacted alum in the web surface elements penetrated by the surface size mixture and to assure the formation of paper having a water extractable pH in the range of about 4.0 to below 6.0.
The foregoing invention surface size formulation specifies a range of about 0.125 to 0.150% of sodium bicarbonate to be mixed with AKD synthetic size. This quantity of sodium bicarbonate is predicated on a correspondingly specified quantity of alum (e.g. about 1.3 to 2.6%) as being all the alum in the cellulosic system: including the normal excess to assure complete precipitation of the anionic rosin. Presence in the web of greater quantities of alum or other sources of free ions will necessarily change the quantity of sodium bicarbonate required to neutralize the web surface.
Developmental experience with the present invention empirically revised the quantity of sodium bicarbonate necessary for combination with the surface size mixture. Sporadically and within a variable time period of days to weeks, a fine "dust" appeared spontaneously on the invention paperboard surface. Analysis proved the "dust" to be uncured AKD that released from the fiber matrix. Although the chemical nature of the "dust" was apparent from the analysis, it was not obvious why the unbound AKD was present or how the occurrence could be prevented. Negatively, such dust tended to disrupt the operation of printing presses and converting machines.
Continued experimentation and development resolved the "dusting" phenomena by increasing the relative quantity of sodium bicarbonate buffer present in the surface size mixture to the 0.125 to 0.150% range described above. Nevertheless, it remains unobvious as to why the buffer concentration needs to be this high.
Mechanical and other properties respective to paper produced according to the Table I size formulations during the said six trial periods were measured and recorded. Table II below describes representative averages corresponding to the present invention sizing process and to the control process, respectively.
TABLE II__________________________________________________________________________ Control InventionTrial Range Average 1 2 3 4 5 6 Average__________________________________________________________________________Basis Weight, g/m.sup.2 197-201 199 204 171 170 204 198 198 --Caliper μm 263-267 265 256 211 211 256 262 262 --Coated Brightness % Elrepho 79.4 79.4 81.2 81.6 81.3 81.7 82.3 81.6 81.6Sheffield Smoothness 94-165 120 31 15 27 52 47 74 41Coated SideSheffield Smoothness 208-230 220 175 173 164 181 206 234 189Uncoated Side2 min. - 20% Lactic 25-30 27.5 39 38 33 28 41 29 35Acid Cobb g/m.sup.2Hydrogen Peroxide 1.5-2.3 1.9 0.81 0.80 0.82 0.84 0.84 0.80 0.81Edge Wicking kg/m.sup.21% Lactic Acid 0.36-0.37 0.37 0.58 0.58 0.5 0.57 0.53 0.52 0.547Edge Wicking kg/m.sup.2Bacterial Organisms 170-1250 603 Not NT NT NT 75 55 65colonies/gram Tested__________________________________________________________________________
Although the data reported by Table II is self explanatory, some observations are noteworthy. It will be recalled that paper made with a natural rosin internal sizing has superior hydrogen peroxide wicking resistance but usually poor lactic acid resistance. Just the opposite is true of paper internally sized with synthetic or AKD sizing. Since the reference or control paper described by Table II was produced with an AKD internal sizing, good lactic acid holdout is expected. However the invention, with no synthetic in the internal size, performed as well. Additionally, the invention hydrogen peroxide wicking performance was 57% better than the control paper.
Observe next, the brightness characteristic. Here, the invention clearly gains a two percentage point Elrepho advantage over the control paper. This advantage may be directly attributed to the low or acid pH of the formation furnish. Surprisingly, however, the invention product is smoother than the control product. On the web coated side, the smoothness improvement is three times greater than the control. The uncoated side gains a 14% improvement. Although still unconfirmed, it would appear upon exiting the headbox that the fiber distribution accruing from the invention sizing process is more uniform, thereby permitting improved web formation. Good papermachine fiber distribution generally translates to web surface smoothness. The direct commercial value in paper surface smoothness derives from the quality of applicable print. An extremely smooth paper surface is required for high fidelity print reproduction.
In another test program, samples of laminated, aseptic food cartons were fabricated from the aforedescribed control and invention papers. Before scoring, cutting and erecting, 0.0104 in. caliper paperboard sample sheets received: (1) an exterior surface coating of polyethylene, (2) an interior surface coating, adjacent the paperboard, of polyethylene, (3) an interior layer of aluminum foil, and (4) an interior coating of polyethylene over the foil to serve as the content contact surface. A first production run of fifteen thousand such sample cartons from each paper source, control and invention, were fabricated in a 250 ml volume size. All fold lines in the first test series were double scored prior to carbon erection. The exterior polyethylene coated surface of this first production run paperboard was decorated by an offset printing process.
Mechanical erection of these double scored cartons revealed a great discrepancy of corner-fold capacity. Corner-fold defects may be either: (a) aesthetically undesirable, non-crisp corners or (b) functional failures such as score cracking wherein a lamination break permits biological contamination of contents from the outside or leakage and liquid loss from the carton inside. From the control sized paperboard, 25% of the erected cartons were rejected for corner-fold defects. A second, first test series production run of fifteen thousand cartons from control sized paperboard produced 22% corner-fold defects.
In contrast, a fifteen thousand carton first test series production run of paperboard, sized according to the present invention and double scored, caused only 12.1% corner fold defects: a performance improvement of approximately 50%.
Similar results were obtained from a second corner-fold test series wherein the cartons were flexographically printed and single scored. Two fifteen thousand carton production runs of control sized paperboard produced 17.1% and 17.9% corner fold defects, respectively. Two fifteen thousand carton production runs of corresponding invention sized paperboard produced 8.3% and 8.9% corner fold defects. Again, a 50% performance improvement.
In a final test program, three separate reel strip samples of uncoated paper produced using the invention process were tested to determine their water extractable pH values via the standard procedure outlined in TAPPI T 509 OM-83. In this procedure one-half inch wide reel samples were taken from three different production runs. Each strip was cut into one-half by one-half inch squares, which were subsequently mixed together. One gram of this paper was placed into a beaker with 70.0 ml. of water for one hour. After one hour of soaking, the mixture was stirred and the pH measured. When the pH was steady for 30 seconds, the measurement was recorded. The results are listed in Table III below:
TABLE III______________________________________Water Extracted pH Levels of PaperReel Strip No. pH Average pH______________________________________1 5.30 5.321 5.332 5.25 5.282 5.313 5.26 5.283 5.29______________________________________
The metabolic activity of microorganisms in an environment is directly and indirectly affected by the hydrogen ion concentration (pH) of that environment. For paper (and paperboard) to be used in the aseptic packaging of food products, the low or acid pH furnish permitted by the natural rosin internal size of the present invention is of commercial significance, as this condition helps provide a highly reduced level of bacteriological contamination.
Furthermore, the fact that the paper produced via the invention process has a water extractable pH in the range of about 4.0 to below 6.0 is also of commercial importance, as this pH level contributes greatly to the aseptic properties of the paper. That is, the pH of the paper affects the ionic state and the availability of many metabolites and inorganic ions. This, in turn, influences the stability of macromolecules present in the biological systems of microorganisms.
Table IV below contains a list of common microorganisms with which aseptic packagers must contend, as well as the minimum, optimum, and maximum pH levels at which these microorganisms can multiply.
TABLE IV______________________________________Minimum Optimum, And Maximum pH Levels ForMultiplication Of Common MicroorganismsMicroorganism Minimum Optimum Maximum______________________________________Thiobacillus thiooxidans 1.0 2.0-2.8 4.0-6.0Enterobacter aerogenes 4.4 6.0-7.0 9.0Escherichia coli 4.4 6.0-7.0 9.0Proteus vulgaris 4.4 6.0-7.0 8.4Clostridium sporogenes 5.0-5.8 6.0-7.6 8.5-9.0Sphaerotilus natans 5.5 6.5-7.5 8.5-9.0Pseudomonas aeruginosa 5.6 6.6-7.0 8.0______________________________________
It should be noted that the optimum pH level for each of the above microorganisms falls outside of the pH range of the paper produced via the invention process, thereby confirming that paper produced via the invention process will inhibit the growth rate of each of these microorganisms. This inhibition is clearly shown by the results contained in Table II. There the control paper (which had a pH of 6.0 and above) was measured to contain from 170-1250 bacterial organism colonies per gram of paper, with an average count of 603 colonies/gram. On the other hand, paper made by the invention process contained from 55-75 bacterial organism colonies per gram of paper, with an average of count of 65 colonies/gram. This equates to a ten-fold reduction in contamination.
Many modifications and variations of the present invention will be apparent to one of ordinary skill in the art in light of the above teachings. It is therefore understood that the scope of the invention is not to be limited by the foregoing description, but rather is to be defined by the claims appended hereto. | Paper that is uniquely suitable for use in the aseptic packaging of foods, beverages, and the like is produced via a two step sizing process comprising an internal size step and a surface size step. The internal size includes approximately 1.0% anionic rosin and about 1.3 to 2.6% alum (based on the dry pulp weight) blended to a 4.0 to 4.5 pH controlled papermachine headbox stock furnish. Following web formation and drying, the surface size is applied with a composition including about 0.025 to 0.050% alkyl ketene dimer (based on the dry pulp weight) blended with a traditional starch formulation and sufficient sodium bicarbonate to both neutralize any unreacted alum present near the surface of the internally sized web and to produce a paper having a water extractable pH level of from about 4.0 to below 6.0. Secondary web drying follows the surface size application. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to method and unit for processing a contaminated liquid, and more particularly relates to formation of a field of super critical conditions within an agitation chamber containing a liquid contaminated with a harmful compound or compounds such as polychlorinated biphenyl (PCB) unsuited for any chemical reactions under normal conditions for the purpose of liberation and removal of such a compound or compounds.
In this specification, the term “a harmful compound” refers to a compound which poses malign influences, in any forms, on healthy human life and is unsuited for any chemical reactions under normal conditions.
Further, the term “perforated” encompasses a substantially planar construction which is provided with one or more holes opening in both surfaces of an agitator and/or one or more recesses formed in at least one of both surfaces of an agitator.
Conventionally, the following expedients have been generally employed in order to convert a harmful compound, which is unsuited for chemical reactions by use of reactants under normal conditions, into a harmless compound via reactions.
One of such expedients is called “separation of super critical water by oxidation”. Here the term “super critical water” refers to a kind of water placed under a condition in which the temperature is 374° C. or higher and the pressure exceeds 22 MPa. Such a water has a property to move actively just like gases to separate a target, i.e. a harmful compound. In practice it is required that the temperature is about 600° C. and the pressure is about 22 MPa.
Another of such expedients is called “separation by alkali catalyst”. In the case of this process, hydrogen provider, carbon type catalyst and alkali such as potassium hydroxide are added to a harmful compound, and the mixture is heated at a temperature in a range from 300 to 350° C. under presence of nitrogen in order to eliminate a part of the harmful compound, for example chlorine in the case of PCB.
In the case of such conventional expedients, however, it is necessary to carry out the process within a closed environment under high temperature and high-pressure conditions and/or under presence of nitrogen gas. This entails use of a reaction device well resistant to corrosions by high temperature, high pressure and reaction gas. In addition, high level of process control and maintenance of the device are required. For these reasons, the conventional expedients are suited for only batch-type processing but not for continuous processing. Consequently, all of the conventional expedients were not feasible in practice from the viewpoint of economic efficiency.
SUMMARY OF THE INVENTION
It is thus the primary object of the present invention to enable rapid conversion of a harmful compound into a harmless compound such as dechlorination of PCB under normal temperatures and normal pressures in a continuous mode.
In accordance with one aspect of the present invention, an agitation chamber is provided which incorporates two or more horizontal perforated agitators arranged in a vertically spaced superposed positions, a mixed solution of contaminated liquid containing harmful compounds and reactant capable of coupling to free radicals from the compounds is prepared, the mixed solution is charged into the agitation chamber, the agitators are driven for rotation at a speed in a range from 10,000 to 18,000 rpm, and a processed solution is discharged from the agitation chamber.
In accordance with another aspect of the present invention, a vertical-type agitation chamber is formed in a substantially closed construction, two or more horizontal perforated agitators are incorporated in the agitation chamber in a vertically spaced superposed arrangement, means are provided for charging into the agitation chamber a mixed solution of a contaminated liquid containing harmful compounds and a reactant capable of coupling to free radicals from the compounds, means are provided for driving the agitators for rotation at a speed in a range from 10,000 to 18,000 rpm, and means are provided for discharging a processed solution from the agitation chamber.
The agitator may take the form of either a circular disc or a branched disc.
In the system of the present invention of the above-described aspects, high-speed rotation of the agitators causes intense and dynamic frictional contact of the mixed solution with the surfaces of the agitators. This frictional contact generates heat of high temperature (from 230 to 300° C.). In addition, centrifugal force caused by the frictional contact strongly compresses the mixed solution within the holes and/or recesses in the agitators and the mixed solution in the region near the side wall of the agitation chamber, thereby creating a high pressure condition of 22 MPa or higher. Further, due to Bernoulli effect, high speed rotation of the agitators causes a large pressure drop in the mixed solution and such pressure drop causes generation of lots of fine bubbles via cavitation. These fine bubbles are destroyed by shearing force created by the high-speed rotation of the agitators.
Combination of the high temperature with the high pressure creates a field of super critical conditions within the agitation chamber. Such conditions induce a radical reaction by which a part of the contaminated liquid is liberated in the form of free radicals. In addition, destruction of the fine bubbles generates super sonic which promotes the above-described radical reaction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional side view of one embodiment of the unit for processing a contaminated liquid in accordance with the present invention,
FIG. 2 is a sectional plan view of the unit shown in FIG. 1,
FIG. 3 is a plan view of one embodiment of the agitator used for the unit shown in FIGS. 1 and 2,
FIG. 4 is a plan view of another embodiment of the agitator used for the unit shown in FIGS. 1 and 2,
FIG. 5 is a sectional side view of the other embodiment of the agitator used for the unit shown in FIGS. 1 and 2,
FIG. 6 is a plan view of a further embodiment of the agitator used for the unit shown in FIGS. 1 and 2,
FIG. 7 is a plan view of a still other embodiment of the agitator used for the unit shown in FIGS. 1 and 2,
FIG. 8 is a sectional side view of another embodiment of the unit for processing a contaminated liquid in accordance with the present invention,
FIG. 9 is a plan view of the hood usable for said unit, and
FIG. 10 is a schematic side view of one example of a plant incorporating the unit of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the unit for processing a contaminated liquid in accordance with the present invention is shown in FIGS. 1 and 2, in which circular discs are used for the agitators.
The unit includes a processing unit 1 of a substantially closed construction and of an octagonal cross-sectional profile. Connections to later described conduits and partition are all sealed properly in a known manner. The interior of the processing unit 1 is divided into an upper cooling chamber 20 and a lower agitation chamber 10 by a horizontal partition 2 .
The cooling chamber 20 is used for suppressing rise in temperature within the agitation chamber 10 to be caused by the radical reaction. To this end, the cooling chamber 20 is associated with supply and exhaust conduits 21 , 22 and the supply conduit 21 is connected to a proper supply source of cooling water not shown. A proper cooling device may be provided between the supply and exhaust conduits 21 , 22 for constant circulation of the cooling water.
A rotary shaft 3 extends vertically thorough the center of the agitation chamber 10 in connection to an outside drive motor 5 via a bearing case 4 arranged in the cooling chamber 20 . The drive motor 5 is properly mounted atop the processing unit 1 . The drive motor 5 is designed to drive the rotary shaft 3 for rotation at a speed from 10,000 to 18,000 rpm.
Three sets of circular discs 16 are horizontally and concentrically secured to the rotary shaft 3 in a vertically spaced superposed arrangement. Each circular disc 16 is provided with one or more vertical through holes or one or more recesses 19 formed in at least one surface thereof. In the following description, however, it is assumed that the through holes are formed in the circular disc 16 . The superposed circular discs 16 may be different in diameter.
A supply conduit 11 of the mixed solution opens in the agitation chamber 10 near the bottom end thereof. The supply conduit 11 is connected, via a pump 12 and a control valve 13 to a supply source (not shown) of the mixed solution. The supply source contains the contaminated liquid containing a harmful compound and a reactant capable of coupling to free radicals to be liberated from the compound. As an alternative, the supply source may be accompanied with a separate reservoir for such a reactant.
An exhaust conduit 17 associated with a control valve 18 opens in the agitation chamber 10 near the top end thereof. A plurality of supply and exhaust conduits 11 , 17 may be connected to the agitation chamber 10 .
A plurality of baffle pieces 14 are secured to the side wall of the agitation chamber 10 with circumferential distribution near the top and bottom ends of the agitation chamber 10 . As best seen in FIG. 2, each baffle pieces 14 is triangular in shape and projects toward the center of the agitation chamber 10 .
At positions between adjacent circular discs 16 , deflector rings 15 are secured to the sidewall of the agitation chamber 10 . As shown in FIG. 2, the inner edge of each deflector ring 15 extends toward the center of the agitation chamber 10 beyond the outer edge of the associated circular discs 16 .
In operation, the mixed solution is charged into the agitation chamber 10 via the supply conduit 11 . As the circular discs 16 are driven for high speed rotation, the mixed solution first tends to flow upwards from the bottom region in the chamber while convoluting about the center of the agitation chamber 10 . The upward flow of the mixed solution is, however, hampered by the lowest deflector ring 15 and directed inwards along the surface of the lowest circular disc 16 . This deflection of flow results in increased dynamic contact between the mixed solution and the adjacent circular discs 16 .
Next, the mixed solution changes its flow direction outwards due to centrifugal force generated by the high-speed rotation of the circular discs 16 . On collision against the sidewall of the chamber, the mixed solution again tends to flow upwards. This upward flow is hampered by the next deflector ring 15 and the mixed solution again flows towards the center of the chamber.
While repeating this process, the mixed solution gradually flows upwards within the agitation chamber 10 while convoluting. During this process, the convoluting mixed solution is directed towards the center of the chamber by the baffle pieces 14 to further increase its dynamic contact with the circular discs 16 .
When the agitation chamber 10 is provided with neither the baffle pieces nor the deflector rings, the mixed solution charged into the agitation chamber 10 would flow directly upwards while convoluting along the side wall of the chamber due to the centrifugal force, thereby reducing dynamic contact with the circular discs 16 . The baffle pieces 14 and the deflector rigs 15 are used to avoid such an undesirable situation.
As the circular discs 16 rotate at a high speed under increased dynamic contact with the mixed solution, dynamic friction between the mixed solution and the circular discs generates heat of high temperature from 230 to 300° C. or higher. Concurrently with this process, the centrifugal force generated by the high-speed rotation of the circular discs strongly compresses the mixed solution against the sidewall of the agitation chamber 10 , thereby resulting in significant rise in pressure of the mixed solution (higher than 22 Mpa). Such rise in pressure occurs also in the holes 19 in the circular discs 16 . That is, the mixed solution within each hole 19 is strongly compressed against the sidewall of the hole 19 remote from the center of the chamber. In addition, the pressure of the mixed solution drops greatly due to Bernoulli effect following the high-speed rotation of the circular discs 16 and lots of fine bubbles arm generated via cavitation. These bubbles are destroyed by the shearing force generated by the high-speed rotation of the circular discs 16 to generate super sonic speed which promotes rise in pressure of the mixed solution.
Due to the combined effect of the high temperature caused by frictional heat and the high pressure caused by centrifugal force, a field of super critical conditions is created within the agitation chamber 10 and the radical reaction occurs to liberate a part of the harmful compounds contained in the contaminated liquid in the form of free radicals. The free radicals are coupled to the reactant to convert the harmful compounds into harmless compounds. Destruction of the fine bubbles generates super sonic speed which well promotes the above-described radical reaction.
Thus, processing of the mixed solution is completed and processed solution flows upwards near the top end of the agitation chamber 10 while convoluting so as to be discharged outside the processing unit 1 via the exhaust conduit 17 .
One example of the design of the processing unit is shown in Table 1.
TABLE 1
Specification of a processing unit
capacity of agitation chamber
20 liters
diameter of circular disc
280 mm
thickness of circular disc
8 mm
number of circular disc
4
gap between discs
25 mm
diameter of hole
10˜20 mm
number of hole
56
surface percentage of holes
24%
arrangment of holes
12 radical directions
center angle
30 degrees
The system of this invention is applicable to processing of contaminated liquids containing various harmful compounds. Most typically, the system is well suited for processing of a contaminated liquid containing PCB (polychlorinated biphenyl). In this case, a solid sodium is used for the reactant. As stated above, the radical reaction liberates chlorine in PCB as free radicals which reacts with sodium to produce sodium chloride. That is, harmful PCB is converted into harmless sodium chloride. Thus, the processed solution contains biphenyl and sodium chloride can be discharged outside the system without any detriment to healthy human life.
The system of the present invention is additionally applicable to processing of industrial wastes such as liquid isolation oils for capacitors and exhaust oils. In the case of contaminated soils, proper liquidation is employed for processing by the system of the present invention.
Another embodiment of the circular disc usable for the processing unit of the present invention is shown in FIG. 3, in which a circular disc 16 is provided with a plurality of vanes 161 secured onto at least one of its upper and lower surfaces near the outer edge. Each vane 161 is arranged with some bias with respect to the radial direction of the disc. As the circular discs 16 rotate at a high speed, the vanes 161 force the mixed solution near the surface or surfaces of the disc to flow radially outwards to enhance the centrifugal effect and the shearing effect on the fine bubbles.
The other embodiment of the circular disc 16 is shown in FIG. 4, in which a plurality of annular vanes 162 are secured onto at least one of its upper and lower surfaces. The annular vanes 162 have different diameters and arranged concentrically around the rotary shaft 3 . As the circular discs 16 rotate, the mixed solution is compressed against the inner wall of each annular vane 162 on the side remote from the center of the disc to promote its pressure rise. Shearing of the fine bubbles generated by cavitation is also reinforced.
The other embodiment of the circular disc 16 is shown in FIG. 5, in which the circular disc 16 has a hollow construction. More specifically, the circular disc 16 is internally provided an annular chamber 163 formed around the center thereof, which communicates with outside via holes 19 . As the disc 16 rotates at a high speed, the mixed solution outside the disc flows into the annular chamber 163 and strongly compressed against inner wall on a side remote from the center of the disc to promote rise in pressure.
Although circular discs are used for the agitator in the foregoing embodiments of the present invention, various different types of agitators are usable for the present invention. FIG. 6 shows a three-branched disc 36 whereas FIG. 7 shows an eight-branched disc 37 . Since the disc as the agitator is subjected to high speed rotation, the shapes and the arrangement of the branches need to be designed carefully so as to assure good dynamic balance during rotation.
As the discs rotate at a high speed, the branches strongly agitate the mixed solution within the agitation chamber 10 for increased pressure rise and, concurrently, furiously destroy the fine bubbles by shearing effect for promoted liberation of free radicals.
Another embodiment of the unit for processing contaminated liquid in accordance with the present invention is shown in FIG. 8, which provides increased cooling effect of the agitation chamber. Parts substantially same as those in the embodiment show in FIG. 1 are indicated with same reference numerals.
A processing unit 1 is divided by a horizontal partition 2 into upper and lower cooling chambers 20 a , 20 b . Like the embodiment in FIG. 1, the cooling chambers are associated with supply and exhaust conduits 21 , 22 of cooling water. The two cooling chambers may communicate each other.
A hollow cylindrical case 6 extends into the lower cooling chamber 20 b to internally define an agitation chamber 10 . This agitation chamber 10 is mostly embraced by the lower cooling chamber 20 b for increased cooling effect. A supply conduit 11 of mixed solution opens in the bottom section of the agitation chamber 10 while an exhaust conduit 17 of processed solution opens near the top end of the agitation chamber 10 .
A bearing case 4 secured to the processing unit 1 rotatably holds a rotary shaft 40 projecting centrally into the agitation chamber 10 . The rotary shaft 40 has a hollow construction and provided with an axial hole 41 opening at the upper end. The rotary shaft 40 is connected in operation to a drive motor 5 secured atop the processing unit 1 .
In the agitation chamber 10 , the lower section of the rotary shaft 40 holds circular discs 16 in an arrangement same as that in the embodiment shown in FIG. 1 . The bottom end of the rotary shaft 40 securely holds a conical hood 44 which converges downwards. As shown in FIG. 9, the inner surface of this hood 44 is provided with a plurality of vanes 45 which are somewhat biased in arrangement from the radial direction of the hood 44 .
A supplementary cooling chamber 20 c is defied by a hollow case 7 whilst surrounding the top end of the rotary shaft 40 . Within the cooling chamber 20 c , the top end of the rotary shaft 40 securely holds a conical hood 46 which converges upwards. A supply conduit 42 of cooling water connected to a given supply source (not shown) extends downwards through the axial hole 41 in the rotary shaft 40 and opens at the bottom end into the axial hole 41 . The cooling chamber 20 c is associated with one or more exhaust conduit 43 of the cooling water.
In operation, cooling water charged into the cooling chambers 20 a , 20 b is discharged outside the system via the exhaust conduits 22 while cooling the agitation chamber 10 and the bearing case 4 . Cooling water introduced into the axial hole 41 of the rotary shaft 40 flows upwards while cooling the rotary shaft 40 . At the top end of the axial hole 41 , it overflows into the supplementary cooling chamber 20 c and is spattered radially outwards so as to be discharged outside the system through the exhaust conduit 43 . The mode of flow of the mixed solution charged into the agitation chamber is substantially same as that in the embodiment shown in FIG. 1 .
One example of a batch-type plant incorporating the processing unit of the present invention is shown in FIG. 10 . The processing unit 101 is connected on the upstream side to a reservoir tank 102 of contaminated liquid via a mixing unit 104 for addition of reactant. On the downstream side, the processing unit 101 is connected to a reservoir tank 108 of processed solution via a cooling unit 107 . The processing unit 101 is further connected to an activated carbon unit 110 via a cooling unit 109 .
In accordance with the preset invention, successful creation of the field of super critical conditions enables continuous processing of contaminated liquid under normal temperature and pressure conditions. It is not required for the processing to utilize burning steps and to employ advanced preparation of high temperature and/or pressure conditions. The system accompanies no production of undesirable arisings, harmful ashes thereby assuring safe operation of the system.
Possibility of continuous processing at high operation efficiency allows large scale processing at a small plant, thereby reducing the operation and installation costs greatly. Since the system is an entirely closed construction, it produces substantially no harmful substances to be discharged outside the system. | For conversion of harmful compound in contaminated liquid into harmless compound by use of reactant, a plurality of agitators are arranged in a vertical superposition within a closed agitation chamber and, after the contaminated liquid is charged into the agitation chamber, the agitators are driven for rotation at a high speed in a rage from 10,000 to 18,000 rpm in order to create a field of super critical conditions in which free radicals are liberated from the harmful compound and coupled by the reactant. Neither high temperature heating nor high level pressurization is needed for processing of the contaminated liquid. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to thrust augmentation in gas turbine engines, and more particularly to pilot stabilized combustion in a swirl augmentor.
2. Description of the Prior Art
Turbojet engines for aircraft use operatively produce a stream of gases exiting from the engine. The thrust generated by an engine is a function of the exhaust gas velocity and of the exhaust gas pressure. The higher the velocity and the higher the pressure of the exiting gases, the higher the corresponding thrust becomes. To obtain high velocities, fuel and high pressure air are burned in a combustion chamber within the engine. The high pressure air is supplied to the combustion chamber by a compressor upstream of the chamber. A predominant amount of the energy added to the medium gases in the combustion process is used to drive the compressor. The remaining portion of the added energy is convertible to engine thrust.
Early in the development of turboject engines and in response to the military need for high performance aircraft, a second combustion station was added downstream of the turbine section to augment the thrust contribution of the main combustor. At the second combustion station the velocity of the gases is increased by adding additional energy to the gases. Combustion at the second station has become commonly known as "augmenting" or "after-burning", reburning of the gases originally burned in the main combustor.
Techniques employed in afterburners were at their inception, and remain today, quite distinct from those employed in main combustors. In particular, combustion concepts directed to the stabilization of a flame front at each respective combustion station differ widely. In main combustors the aerodynamic effects of locally swirling gases are employed to stabilize the flame front at the desired location. U.S. Pat. No. 2,676,460 to Brown entitled "Burner Construction of the Can-Annular Type Having Means For Distributing Airflow to Each Can" is representative of swirl stabilized main combustors. In augmentors, on the other hand, bluff body flameholders are disposed across the path of the medium gases to induce recirculation of gases behind the flameholders. Recirculation of the gases stabilizes and holds the flame front at the proximate location of the flameholder. U.S. Pat. No. 2,702,452 to Taylor entitled "Flameholder Construction" is representative of early concepts for flameholder stabilization in augmentors.
The augmentor of Taylor is directed to a turbojet type gas turbine engine. Since the early 1960's, however, gas turbine engines of prime importance have been those based upon the turbofan cycle. In a turbofan cycle engine a substantial portion of the air flowing through the engine is caused to bypass the main combustor. At the augmentor, therefore, the gas stream is comprised of a central core stream of relatively hot gases from the main combustor and a surrounding bypass stream of relatively cool gases. Before effective combustion of the combined streams can be affected, the cold air stream must be heated as through mixing with the hot core gases. One widely accepted technique for mixing the gases is to shape the afterburner flameholder such that it causes hot gases of the core to be directed outwardly into the cold air stream. U.S. Pat. No. 3,295,325 to Nelson entitled "Jet Engine Afterburner Flameholder" illustrates such a shaped flameholder and describes its operation.
Very recent advances in combustor and augmentor technology are disclosed in U.S. Pat. No. 3,788,065 to Markowski entitled "Annular Combustion Chamber For Dissimilar Fluids in Swirling Flow Relationship" and in U.S. Pat. No. 3,747,345 to Markowski entitled "Shortened Afterburner Construction For Turbine Engine" which adapts the concepts of the U.S. Pat. No. 3,788,065 to augmentor embodiments. The concepts disclosed in these Markowski patents are now known in the industry as "swirl burning". Note in the U.S. Pat. No. 3,747,345 that, even with these most recent combustion techniques, the flame stabilization concepts of prior turbojet and turbofan augmentors are utilized.
Scientists and engineers in the gas turbine field are continuing to search for new stabilization concepts and techniques, and particularly those which can adapt swirl burning techniques to effective embodiments.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a thrust augmentor capable of reliable and stable operation over a wide range of engine operating conditions. The employment of swirl burning principles in the augmentor is one particular aim, and effective means for stabilizing the flame front in such an augmentor is sought.
According to the present invention, a continuously operative pilot burner positioned in the radially outward region of a thrust augmentor ignites and stabilizes the combustion of differing density gases in a strongly swirling flow field.
A primary feature of the present invention is the swirl augmentor. An inner row of vanes in the core duct and an outer row of vanes in the bypass duct are adapted to establish two concentric swirling flows. In at least one embodiment the inner and outer vanes are rotatable so as to vary the amount of swirl imparted to the gases flowing thereacross. Another feature is the pilot burner positioned radially outward of the concentric flows. Means for supplying fuel to the augmentor is positioned inwardly of the flow divider. The pilot burner is of the annular premixing type and includes a plurality of circumferentially spaced vanes disposed across the fuel/air mixture. The burner has a convergent passage immediately upstream of the vanes and a divergent passage immediately downstream of the vanes. An essentially cylindrical flow guide extends downstream of the inner ends of the vanes into the divergent passage.
A principal advantage of augmentor apparatus incorporating the concepts of the present invention is reduced susceptibility to lean blowouts. In the apparatus disclosed, the blowout limit of the augmentor is defined by the lean flammability limit of the pilot burner alone. Another advantage is reduced drag losses in the augmentor as enabled through the elimination of a mechanical flameholder in the main flow of the augmentor. The pilot burner positions and stabilizes the flame front within the augmentor and is operable over a wide range of inlet pressures.
The foregoing and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of the preferred embodiment thereof as shown in the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a simplified, partial cross section illustration of a turbofan, gas turbine engine showing detailed components of the thrust augmentor;
FIG. 2 is a simplified, partial perspective view of the augmentor illustrated in FIG. 1; and
FIG. 3 is an enlarged view of the augmentor pilot.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An augmented turbofan engine is illustrated in FIG. 1. The engine principally includes a fan section 10, a compressor section 12, a main combustor section 14, a turbine section 16, a thrust augmentor section 18 and an exhaust nozzle section 20. A core duct 22 carries to the compressor section a portion of the working medium gases discharged from the fan section. These gases are subsequently flowed through the main combustor section and through the turbine section to the augmentor section of the engine. The gases flowing through the core duct are hereinafter referred to as "core gases". A bypass duct 24 carries the remaining portion of the working medium gases discharged from the fam section, around the compressor, main combustor, and turbine sections to the augmentor section. The gases flowing through the bypass duct are hereinafter referred to as "bypass gases".
The thrust augmentor section is enclosed within a casing 26. A tailcone 28 is centered about the engine axis 30. An intermediate casing 32 separates the core gases entering the augmentor and the bypass gases entering the augmentor into two concentric streams. A flow divider 34 is spaced radially between the intermediate casing and the augmentor casing to divide the bypass gases into an inner stream 36 and an outer stream 38.
A plurality of core vanes 40 is disposed across the core gases between the tailcone and the intermediate casing. A plurality of bypass vanes 42 is disposed across the inner stream of the bypass gases between the intermediate casing and the flow divider. Both the core vanes and the bypass vanes are adapted to swirl the flow passing thereacross circumferentially about the engine and in the same direction. A plurality of circumferentially extending spray rings 44 is disposed across the augmentor downstream of the core vanes and the bypass vanes. Fuel supply means 46 direct the main augmentor fuel to the spray rings.
A pilot burner 48 is positioned radially outward of the flow divider. The pilot burner, as shown in greater detail in FIG. 3, has an essentially cylindrical outer liner 50 which is concentric with the augmentor casing 26. A plurality of circumferentially spaced pilot vanes 52 extend radially inward from the outer liner to an inner liner 54. A convergent passage 56 is formed between the inner and outer liners upstream of the vanes and a divergent passage 58 is formed immediately downstream of the vanes. Fuel injection means, such as the spray ring 60 is disposed to discharge fuel into the convergent passage 56 where the fuel becomes mixed with air flowing into the pilot burner. A cylindrical flow guide 62 extends into the divergent passage 58 from the radially inner ends of the pilot vanes. The flow guide extends over a comparatively short axial length and, in the contour illustrated one hundred thousandths to two hundred thousandths of an inch (0.100-0.200 inch) is known to be adequate. The outer liner 50 is penetrated by an igniter 64.
During operation of the augmentor fuel and air are mixed in the convergent passage 56 of the pilot burner. The fuel/air mixture accelerates as the passage decreases in the cross-sectional area. As the mixture is directed across the pilot vanes 52, the vanes impart a circumferential swirl to the mixture. Swirling the mixture establishes a radial static pressure gradient across the flow. A swirl angle of discharge across the vanes of fifty degrees (50°) is known to be effective in establishing the gradient. The flow containing the radial pressure gradient is directed into the divergent passage 58, past the flow guide 62. Sudden expansion of the flow into the divergent passage at the end of the flow guide causes recirculation of the fuel/air mixture and a substantial residence time of the mixture in the region. As a result of the substantial residence time, combustion in the pilot burner is quite stable once the mixture is ignited by the igniter 64.
Hot gases of low density are discharged from the pilot burner. The temperature of the gases is on the order of thirty-six hundred degrees Rankine (3600° R.) and the density is approximately twenty-seven thousandths of a pound per cubic foot (0.27 lb/ft 3 ).
As is illustrated in FIG. 2, the core vanes 40 and the bypass vanes 42 are adapted to swirl the respective streams flowing thereacross in a circumferential direction about the axis of the engine. A swirl angle of discharge from the vanes on the order of twenty to thirty-five degrees (20°-35°) during augmentor operation is desired such that a strongly swirling flow field is established. The density of the core gases in the swirling field at sea level takeoff condition is approximately sixty-seven thousandths of a pound per cubic foot (0.067 lb/ft 3 ) and the density of the bypass gases at sea level takeoff condition in the swirling field is approximately one hundred sixty-seven thousandths of a pound per cubic foot (0.167 lb/ft 3 ).
One of the major attributes of the augmentor of the present invention is the ability of the apparatus to cause mixing of the bypass and core streams. Directing the core and bypass streams across the core vanes and bypass vanes respectively induces a strongly swirling flow field. The bypass gases are centrifuged radially outward in the swirling flow field thereby displacing the hot pilot gases discharged by the pilot burner. The bypass gases become ignited by the pilot and a flame front is established. The flame front progresses radially inward toward the axis of the engine in a conical pattern as illustrated in FIG. 2. As soon as the flame front penetrates the path of the bypass gases, the core gases become the relatively more dense medium and the core gases in turn become centrifuged outwardly into the combined pilot and bypass gas streams. Complete mixing and burning of both the core and bypass streams without the need of mechanical flameholders or mixers results.
The pilot burner is operative over the entire range of augmentor conditions and serves to position, hold and stabilize the augmentor flame front downstream of the spray rings 44. The pilot burning concepts are particularly advantageous in preventing lean blowout of the augmentor such as occurs in more conventional augmentors under low fuel flow conditions. In effect, the lean blowout point becomes the lean flammability limit of the pilot. As long as the pilot is operating the mainstream augmentor flow can be ignited and stabilized.
Although the invention has been shown and described with respect to preferred embodiments thereof, it should be understood by those skilled in the art that various changes and omissions in the form and detail thereof may be made therein without departing from the spirit and the scope of the invention. | A thrust augmentor for a turbofan, gas turbine engine is disclosed. Techniques for mixing and burning dissimilar density gases in a thrust augmentor are developed. In accordance with one specific teaching the flame front in a swirl augmentor is stabilized by a continuously operative pilot burner. The pilot burner is positioned in the radially outward portion of the augmentor. The pilot burner employs fuel premixing techniques and is adapted to operate at low inlet pressure levels. | 5 |
This application is a division of application Ser. No. 07/443,332, filed Dec. 1, 1989, now U.S. Pat. No. 5,029,046.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to illuminated indicator gauges used, for example, as speedometers and tachometers for a motor vehicle or the like, and more particularly to such gauges of a type which has a visual alarm indicator.
2. Description of the Prior Art
In order to clarify the task of the present invention, one conventional gauge of the above-mentioned type will be described with reference to FIGS. 3 and 4 of the accompanying drawings.
As is seen from FIG. 3, the gauge comprises a meter panel 1 formed with circular openings 3a and 3b which have respective dial boards 2a and 2b received therein. The meter panel 1 has further two visual alarm indicators 4a and 4b mounted thereto and a turning direction indicator 5 mounted thereto.
FIG. 4 shows in detail the meter panel 1 and each of the visual alarm indicators 4a and 4b mounted to the meter panel 1.
The meter panel 1 comprises a transparent base plate 1a made of a rigid plastic, such as polycarbonate or the like, a transparent coloured layer 1b printed on a back surface of the base plate 1a and a smoked layer 1c printed on a front surface of the base plate 1a. The layer 1b is usually coloured red, blue or yellow. A fluorescent transparent substance layer 1d is coated on the smoked layer 1c except the portions with which the visual alarm indicators 4a and 4b and the turning direction indicator 5 are associated. As is known, the fluorescent substance layer 1d emits visible and visionary light under the action of ultraviolet rays. An electric ultraviolet lamp 10 is arranged in front of the meter panel 1.
Each visual alarm indicator 4a or 4b comprises various opaque marks le printed on the smoked layer 1c, lamp housings 6 each having an open end connected to the back surface of the meter panel 1 at the position where the corresponding mark 1e is located, and alarm electric lamps 7 respectively installed in the lamp housings 6.
Thus, when one of the alarm lamps 7 is energized to light upon sensing any trouble of the vehicle, the limited surrounding of the corresponding opaque mark 1e is illuminated to emphasize the mark 1e. With this, a viewer, that is, a driver, can recognize the vehicle trouble.
Of course, none of the alarm lamps 7 lights when the vehicle is in order.
However, due to its inherent construction, the conventional gauge has the following drawbacks.
That is, when, at night, the front surface (that is, the fluorescent substance layer 1d) of the meter panel 1 is visionally illuminated under the action of ultraviolet rays from the ultraviolet lamp 10, the portions of the meter panel 1 where the visual alarm indicators 4a and 4b are positioned appear dark. This phenomenon makes the external view of the illuminated meter panel 1 poor. Furthermore, the difference in brightness between the illuminated portion of the meter panel 1 and the non-illuminated portions of the same sometimes causes difficulties to arise in clearly and quickly reading the indicia on the dial boards 2a and 2b.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an illuminated indicator gauge which is free of the above-mentioned drawbacks.
According to the present invention, there is provided an indicator gauge which comprises a meter panel, the meter panel including a transparent base plate, a transparent coloured layer applied to a rear surface of the transparent base plate and a fluorescent transparent substance layer applied to a front surface of the transparent base plate; a visual alarm indicator including an opaque mark mounted to a given portion of the meter panel, a lamp housing having an open end which is connected to a rear surface of the meter panel in such a manner as to face toward the given portion and an electric lamp installed in the lamp housing; and an ultraviolet lamp arranged in front of the meter panel and generating ultraviolet rays upon electric energization thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a front view of an illuminated indicator gauge according to the present invention;
FIG. 2A is a sectional view of a visual alarm indicator which is used in a first embodiment of the illuminated indicator gauge of the present invention;
FIG. 2B is a view similar to FIG. 2A, but showing an alarm indicator employed in a second embodiment;
FIG. 2C is a view also similar to FIG. 2A, but showing an alarm indicator employed in a third embodiment;
FIG. 2D is a view also similar to FIG. 2A, but showing an alarm indicator employed in a fourth embodiment;
FIG. 2E is a view also similar to FIG. 2A, but showing an alarm indicator employed in a fifth embodiment; and
FIG. 2F is a view also similar to FIG. 2A, but showing an alarm indicator employed in a sixth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is shown an illuminated indicator gauge of the present invention.
Similar to the above-mentioned conventional one, the gauge of the invention comprises generally a meter panel 1 formed with circular openings 3a and 3b which have respective dial boards 2a and 2b received therein. The meter panel 1 has further two visual alarm indicators 4a and 4b mounted thereto and a turning direction indicator 5 mounted thereto. A electric ultraviolet lamp 10 is arranged in front of the meter panel 1.
FIG. 2A shows in detail the meter panel 1 and each of the visual alarm indicators 4a and 4b, which are employed in a first embodiment of the present invention.
The meter panel 1 comprises a transparent base plate 1a made of a rigid plastic such as polycarbonate or the like, a transparent coloured layer 1b printed on a back surface of the base plate 1a and a smoked layer 1c printed on a front surface of the base plate 1a.
Each visual alarm indicator 4a or 4b comprises various opaque marks 1e printed on the smoked layer 1c, lamp housings 6 each having an open end connected to the back surface of the meter panel 1 at the position where the corresponding mark 1e is located, and electric alarm lamps 7 respectively received in the lamp housings 6.
In this first embodiment, a fluorescent transparent substance layer 1d is coated on the opaque marks 1e as well as the smoked layer 1c, and the opaque marks 1e are made of a suitable light reflecting paint.
Thus, when one of the alarm lamps 7 is energized to light upon sensing any trouble of the vehicle, the limited surrounding of the corresponding opaque mark 1e is illuminated to emphasize the mark 1e.
Table-I shows the visibility of each mark 1e and the limited surrounding of the mark 1e which are exhibited when the corresponding alarm lamp 7 is ON and OFF in day time and night time.
As is seen from the table, in day time with the alarm lamp 7 being OFF, the entire outer surface of the meter panel 1, which includes the surfaces for the visual alarm indicators 4a and 4b, shows the colour of the smoked layer 1c, and only the marks 1e are illuminated whity due to reflection of natural light. When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour possessed by the transparent coloured layer 1b, and the mark 1e is shown like a silhouette (dark).
In night time with the alarm lamp 7 being OFF, the entire outer surface of the meter panel 1, which includes the surfaces for the visual alarm indicators 4a and 4b, is visionally illuminated under the action of the ultraviolet rays from the ultraviolet lamp 10, and the marks 1e are visionally illuminated with a colour possessed thereby. When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour which is provided by the combination of the colour of the fluorescent transparent substance layer 1d and the colour of the transparent coloured layer 1b, and the mark 1e is shown like a silhouette (dark).
Referring to FIG. 2B, there is shown a visual alarm indicator 4a or 4b which is employed in a second embodiment of the invention.
In this second embodiment, opaque marks 1e made of a suitable light reflecting white paint are printed on a front surface of the transparent base plate 1a, and a smoked layer 1c is coated on the opaque marks 1e as well as the front surface of the base plate 1a. A fluorescent transparent substance layer 1d is coated on the smoked layer 1c.
Table-II shows the visibility of each mark 1e and the limited surrounding of the mark 1e which are exhibited when the corresponding alarm lamp 7 is ON and OFF in day time and night time.
As is seen from the table, in day time with the alarm lamp 7 being OFF, the entire outer surface of the meter panel 1, which includes the surfaces for the visual alarm indicators 4a and 4b, shows the colour of the smoked layer 1c, and only the marks 1e are illuminated with a colour (glay) which is provided by the combination of the colour of the white marks 1e and the colour of the smoked layer 1c due to reflection of natural light. When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour possessed by the transparent coloured layer 1b, and the mark 1e is shown like a silhouette (dark).
In night time with the alarm lamp 7 being OFF, the entire outer surface of the meter panel 1, which includes the surfaces for the visual alarm indicators 4a and 4b, is visionally illuminated under the action of the ultraviolet rays from the ultraviolet lamp 10, and the marks 1e are out of sight. When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour which is provided by the combination of the colour of the fluorescent transparent substance layer 1d and the colour of the transparent coloured layer 1b, and the mark 1e is shown like a silhouette (dark).
Referring to FIG. 2C, there is shown a visual alarm indicator 4a or 4b which is employed in a third embodiment of the present invention.
In this third embodiment, a smoked layer 1c is coated on the entire outer surface of the transparent base plate 1a. A fluorescent transparent substance layer 1d is coated on the entire outer surface of the smoked layer 1c. Opaque marks 1e made of a white paint are printed on an outer surface of the fluorescent layer 1d. Each mark 1e is coated with another fluorescent transparent substance layer 1d' which emits light whose colour is different from that of the above-mentioned fluorescent layer 1d.
Table-III shows the visibility of each mark 1e and the limited surrounding of the mark 1e which are exhibited when the corresponding alarm lamp 7 is ON and OFF in day time and night time.
As is seen from the table, in day time with the alarm lamp 7 being OFF, substantially entire outer surface of the meter panel 1, which includes the surfaces for the limited surroundings of the marks 1e, shows the colour of the smoked layer 1c, and only the marks 1e are illuminated whity due to reflection of natural light. When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour possessed by the transparent coloured layer 1b and the mark 1e is shown like a silhouetter (dark).
In night time with the alarm lamp 7 being OFF, the entire outer surface of the meter panel 1, which includes the surfaces for the visual alarm indicators 4a and 4b, is visionally illuminated under the action of the ultraviolet rays from the ultraviolet lamp 10, and the marks 1e are also visionally illuminated with a different colour. When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour which is provided by the combination of the colour of the fluorescent transparent substance layer 1d and the colour of the transparent coloured layer 1b, and the mark 1e is kept illuminated with the different colour.
Referring to FIG. 2D, there is shown a visual alarm indicator 4a or 4b which is employed in a fourth embodiment of the invention.
In the fourth embodiment, a smoked layer 1c is coated on the entire outer surface of the transparent base plate 1a. A fluorescent transparent substance layer 1d is coated on the entire outer surface of the smoked layer 1c. Opaque marks 1e made of a white paint are printed on an outer surface of the fluorescent layer 1d.
Table-IV shows the visibility of each mark 1e and the limited surrounding of the mark 1e which are exhibited when the corresponding alarm lamp 7 is ON and OFF in day time and night time.
As is seen from the table, in day time with the alarm lamp 7 being OFF, substantially entire outer surface of the meter panel 1, which includes the surfaces for the limited surroundings of the marks 1e, shows the colour of the smoked layer 1c, and only the marks 1e are illuminated whity due to reflection of natural light. When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour possessed by the transparent coloured layer 1b and the mark 1e is shown like a silhouetter (dark).
In night time with the alarm lamp 7 being OFF, substantially entire outer surface of the meter panel 1, which includes the limited surroundings of the marks 1e, is visionally illuminated under the action of the ultraviolet rays from the ultraviolet lamp 10, and each mark 1e is shown like a silhouette (dark). When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour which is provided by the combination of the colour of the fluorescent transparent substance layer 1d and the colour of the transparent coloured layer 1b, and the mark 1e is shown like a silhouette (dark).
Referring to FIG. 2E, there is shown a visual alarm indicator 4a or 4b which is employed in a fifth embodiment of the invention.
In this fifth embodiment, opaque marks 1e made of a suitable light blocking paint are printed on the exposed surface of the transparent coloured layer 1b which is printed on the back surface of the transparent base plate 1a. A smoked layer 1c is coated on a front surface of the base plate 1a and a fluorescent transparent substance layer 1d is coated on the smoked layer 1c.
Table-V shows the visibility of each mark 1e and the limited surrounding of the mark 1e which are exhibited when the corresponding alarm lamp 7 is ON and OFF in day time and night time.
As is seen from the table, in day time with the alarm lamp 7 being OFF, the entire outer surface of the meter panel 1, which includes the surfaces for the visual alarm indicators 4a and 4b, shows the colour of the smoked layer 1c and the marks 1e are out of sight. When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour passessed by the transparent coloured layer 1b, and the mark 1e is shown like a silhouette (dark).
In night time with the alarm lamp 7 being OFF, the entire outer surface of the meter panel 1, which includes the surfaces for the visual alarm indicators 4a and 4b, is visionally illuminated under the action of the ultraviolet rays from the ultraviolet lamp 10, and the marks 1e are out of sight. When one alarm lamp 7 is lit, the limited surrounding of the corresponding mark 1e is illuminated with a colour which is provided by the combination of the colour of the fluorescent transparent substance layer 1d and the colour of the transparent coloured layer 1b, and the mark 1e is shown like a silhouette (dark).
Referring to FIG. 2F, there is shown a visual alarm indicator 4a or 4b employed in a sixth embodiment of the present invention.
The indicator in this embodiment is substantially the same as that in the second embodiment (FIG. 2B), except for the marks 1e. That is, the marks 1e in the sixth embodiment are made of a light blocking paint.
Thus, the visibility of each mark 1e and the limited surrounding of the mark 1e of this sixth embodiment are substantially the same as those of the second embodiment.
As will be understood from the going description, the illuminated indicator gauge of the present invention has the following advantageous features.
That is, in night time, the substantially entire outer surface of the metal panel 1, which includes the surfaces for the visual alarm indicators 4a and 4b, is illuminated evenly by the action of the ultraviolet rays from the ultraviolet lamp 10, unlike in the case of the afore-mentioned conventional gauge of FIGS. 3 and 4. That is, in the invention, the unsightly non-illuminated portions which would be caused by provision of the visual alarm indicators 4a and 4b do not appear on the illuminated meter panel 1. This improves the external view of the panel 1. For the same reason, clear and quick reading of the indicia on the dial boards 2a and 2b is assured in the invention.
TABLE I______________________________________ Alarm lamp (7) OFF ON______________________________________Mark (1e)Day Whity DarkTime (Silhouette)Night Visionally DarkTime Illuminated (Silhouette)LimitedSurroundingof Mark (1e)Day Colour of Red, Blue, YellowTime Smoked Layer etc.,Night Visionally Red, Blue, YellowTime Illuminated etc.,______________________________________
TABLE II______________________________________ Alarm lamp (7) OFF ON______________________________________Mark (1e)Day Glay DarkTime (Silhouette)Night Out of Sight DarkTime (Silhouette)LimitedSurroundingof Mark (1e)Day Colour of Red, Blue, YellowTime Smoked Layer etc.,Night Visionally Red, Blue, YellowTime Illuminated etc.,______________________________________
TABLE III______________________________________ Alarm lamp (7) OFF ON______________________________________Mark (1e)Day Whity DarkTime (Silhouette)Night Visionally DarkTime Illuminated (Silhouette)LimitedSurroundingof Mark (1e)Day Colour of Red, Blue, YellowTime Smoked Layer etc.,Night Visionally Red, Blue, YellowTime Illuminated etc.,______________________________________
TABLE IV______________________________________ Alarm lamp (7) OFF ON______________________________________Mark (1e)Day Whity DarkTime (Silhouette)Night Dark DarkTime (Silhouette) (Silhouette)LimitedSurroundingof Mark (1e)Day Colour of Red, Blue, YellowTime Smoked Layer etc.,Night Visionally Red, Blue, YellowTime Illuminated etc.,______________________________________
TABLE V______________________________________ Alarm lamp (7) OFF ON______________________________________Mark (1e)Day Out of Sight DarkTime (Silhouette)Night Out of Sight DarkTime (Silhouette)LimitedSurroundingof Mark (1e)Day Dark (Colour of Red, Blue, YellowTime Smoked Layer) etc.,Night Visionally Red, Blue, YellowTime Illuminated etc.,______________________________________ | An indicator gauge is disclosed, which comprises a meter panel. The meter panel includes a transparent base plate, a transparent colored layer applied to a rear surface of the transparent base plate and a fluorescent transparent substance layer applied to a front surface of the transparent base plate. A visual alarm indicator includes an opaque mark mounted to a given portion of the meter panel, a lamp housing having an open end which is connected to a rear surface of the meter panel in such a manner as to face toward the given portion and an electric lamp installed in the lamp housing. An ultraviolet lamp is arranged in front of the meter panel and generates ultraviolet rays upon electric energization thereof. | 1 |
TECHNICAL FIELD
This invention relates to a power plant facility having a first gas-turbine group and, arranged downstream thereof, a first waste-heat boiler, which is in flow connection with a condensing steam turbine.
BACKGROUND OF THE INVENTION
In European patent document EP-A-0 439 754 there is described a power plant facility that has a gas-turbine group having waste-heat boiler and steam turbine ("GuD"=gas and steam turbine process). These processes today achieve electrical efficiencies of up to 58%.
A method of operating a gas turbine described in European patent document EP-B-0 650 554 discloses a mixed gas/steam turbine process in which the injected steam finds use for cooling the combustion chamber. By this means method, the combustion air is no longer required for cooling the combustion chamber, as in conventional gas turbines, but only for controlling the combustion process. For this reason, the ratio of compressor power to turbine power in such mixed gas/steam turbines can be markedly lower than in conventional gas turbines.
A further improvement in heat utilization can be achieved in this process by virtue of the fact that the waste heat of the mixed gas/steam turbine is also partly used for interheating of the steam-unit spent steam supplied to the combustion chamber.
In the processes described, a fact detrimental to the approach to the isothermal combustion power process is that the pressure level declines with the temperature upon the expansion of the working fluid, and so said approach is practically possible only with a few stages. As a consequence, however, substantial elements of the adiabatic combustion power process are preserved.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the invention to design a combustion power process in such a fashion that its approach to an isothermal course in a plurality of stages is possible.
This object is achieved by virtue of the fact that the upstream gas and steam turbine process serves as a steam source of a mixed gas/steam turbine process, downstream of which a steam turbine process is arranged. In this way, the heat supply to the overall process by means of the renewed interheating of the spent steam from the upstream gas and steam turbine process can better approach isothermal heat supply than in a gas- and steam-turbine process alone, by which process the thermodynamic average temperature of the actual process of heat supply is markedly increased. The also important isothermal heat removal takes place with the aid of a downstream steam process in condensing operation, which steam process utilizes the waste-heat streams of the mixed gas/steam turbine.
The use of economizers for feedwater preheating also serves to carnotize the steam or gas/steam mixed-turbine processes. Interlacing of the economizers enhances their efficiency.
The constructive cost for final heat recovery is minimized by use of various inlet points into the condensing steam turbine for the various pressures of various steam streams.
By interheating the working fluid in a gas-turbine group having high-pressure and low-pressure sections, an approach to isothermal heat supply is achieved, which approach in combination with off-gas heat utilization effects an improvement in the thermal efficiency. The same holds for the successively arranged mixed gas/steam turbine groups with interheating. Their waste heat is used in a second waste-heat boiler to generate high-pressure steam, which is utilized in a back-pressure turbine in such a way as to boost the efficiency.
By arranging a third mixed gas/steam turbine group, the waste heat of the first and second mixed gas/steam turbine groups is recovered and further heat is furnished for the condensing steam turbine. This turbine utilizes the residual heat of all three waste-heat boilers in the form of steam streams at various pressure levels. The thermal efficiency is also increased by means of these practices. The constructive cost for the power plant facility according to the invention is reduced by virtue of the fact that a low-pressure compressor of the second mixed gas/steam turbine group is arranged as the first stage of a high-pressure compressor of the first mixed gas/steam mixed-turbine group.
Further process stages arranged in "zipper" fashion can be realized, the closure of the chain being formed by the gas/steam turbine group having downstream waste-heat system and condensing steam turbine.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features of the invention can be inferred from the further Claims, the description that follows, and the drawing, in which
FIG. 1 shows the flow sheet of a power plant facility having one gas-turbine group and one mixed gas/steam turbine group.
FIG. 2 shows the flow sheet of a power plant facility having one gas-turbine group and two mixed gas/steam turbine groups.
DETAILED DESCRIPTION OF THE INVENTION
The power plant facility of FIG. 1 shows a first gas-turbine group 1 having a compressor 2, a combustion chamber 3 and a gas turbine 4. The first gas-turbine group 1 can also, in departure from FIG. 1, be designed in two stages with interheating, in order to approach isothermal heat supply.
Downstream of the first gas-turbine group 1 is a first waste-heat boiler 5, which has a high-pressure section 6, an intermediate-pressure section 7, which can also be equipped with a superheater, not illustrated, and an economizer unit 8. The last accommodates the stack-gas-heated feedwater preheating of the high-pressure section 6 and of the intermediate-pressure section 7, preferably in interlaced arrangement.
The steam generated in the high-pressure section 6 is expanded in the first back-pressure turbine 9 down to a back pressure that lies somewhat above the combustion-chamber pressure of a first mixed gas/steam turbine group 10.
Arranged downstream of the first mixed gas/steam turbine group 10 is a second waste-heat boiler 11, which contains a superheater 12 and an intermediate-pressure section 13 as heating surfaces. The spent steam of the first back-pressure turbine 9 is conveyed via the superheater 12 to a combustion chamber 14 of the first mixed gas/steam turbine group 10. There it mixes with the combustion gases, cools the combustion chamber 14, and is expanded in a first gas/steam mixed turbine 15 to a pressure slightly higher than atmospheric pressure, in order that the flow losses in the second waste-heat boiler 11 can be compensated. A compressor 36 is connected in compressed air delivery relation to the combustion chamber 14.
The steam generated in the intermediate-pressure section 7 of the first waste-heat boiler 5, with the steam generated in the intermediate-pressure section 13 of the second waste-heat boiler 11, is expanded in a condensing steam turbine 16 and condensed in a condenser 17. The pressure of the intermediate-pressure sections 7, 13 can also be different if this leads to better heat utilization. In such a case, in departure from the situation illustrated in FIG. 1, the higher-pressure steam would be admitted to the condensing steam turbine 16 at the inlet while the lower-pressure steam would be admitted at a point of corresponding pressure.
An enlarged power plant facility is shown in FIG. 2. In a second stage, the first mixed gas/steam turbine group 10' is supplemented by a second mixed gas/steam turbine group 18 with interheating.
The first process stage of the power plant facility according to the invention begins with the first gas-turbine group 1, which, as already noted above, can also be designed in departure from the simplified illustration in FIG. 2, preferably with interheating.
Arranged downstream of the first gas-turbine group 1 is a first, enlarged waste-heat boiler 5', which, in addition to the high-pressure section 6, the intermediate-pressure section 7, which here again can be equipped with a superheater, not illustrated, and the economizer unit 8, additionally has a low-pressure section 19. The stack-gas-heated feedwater preheater of the high-pressure section 6 and of the intermediate-pressure section 7, preferably in interlaced arrangement, are located in the economizer unit 8. For the most complete possible heat recovery, the low-pressure section 19 is partly interlaced with the feedwater preheaters of the economizer unit 8 at the end of the first enlarged waste-heat boiler 5'. In accordance with the layout, an arrangement of a superheater belonging to the low-pressure section 19 on the stack-gas side upstream of the economizer unit 8 is also possible.
The steam generated in the high-pressure section 6 of the first enlarged waste-heat boiler 5' is expanded in the first back-pressure turbine 9 to a back pressure that lies somewhat higher than the pressure of the combustion chamber 14 of the first mixed gas/steam turbine group 10'. The steam generated in the intermediate-pressure section 7 exits the first waste-heat boiler 5' at a pressure somewhat higher than the pressure of the combustion chamber 20 of a second mixed gas/steam turbine group 18.
The second process stage of the power plant facility according to the invention begins on the gas side in the successively connected first mixed gas/steam turbine group 10' and the second gas/steam mixed-turbine group 18 with an interheating of the partly expanded off-gases of the first gas/steam turbine group 10'. The off-gas of the second mixed gas/steam turbine group 18 flows through a second enlarged waste-heat boiler 11', which has an interlaced superheater 12', a high-pressure section 21, an intermediate-pressure section 13', which here again can be equipped with a superheater, not illustrated, an interlaced economizer unit 22, and a low-pressure section 23. The combustion chamber 14 of the first mixed gas/steam turbine group 10' is charged with the spent steam of the first back-pressure turbine 9, which is superheated to the greatest possible degree in the interlaced superheater 12'. The quantity of air required for nearly stoichiometric combustion in the combustion chamber 14 is supplied by a high-pressure compressor 25. The combustion chamber 20 of the second mixed gas/steam turbine group 18 is charged with the partly expanded stack-gas/steam mixture of the first mixed gas/steam turbine group 10', the intermediate-pressure steam generated in the intermediate-pressure section 7 and superheated in the superheater 12', and the combustion air delivered by a low-pressure compressor 26.
Given an appropriate layout, it is possible to adapt the spent-steam pressure of the back-pressure turbine 9 to the pressure level of the intermediate-pressure section 7 and thus, in place of the mixed gas/steam turbine groups 10' and 18, to combine into a single machine.
On the other hand, it is also possible to place the low-pressure compressor 26 and the high-pressure compressor 25 in one housing in order to reduce the construction cost.
In a second mixed gas/steam turbine 27 of the second mixed gas/steam turbine group 18, which functions as a low-pressure turbine, the stack gas is expanded to the final pressure, which is less than atmospheric pressure by the stack-gas-side pressure loss of the downstream second enlarged waste-heat boiler 11'.
In the high-pressure section 21 of the second enlarged waste-heat boiler 11', high-pressure steam is generated for a second back-pressure turbine 28. This turbine expands the high-pressure steam to the pressure level of the intermediate-pressure section 13' of the second enlarged waste-heat boiler 11'.
The third process stage of the power plant facility according to the invention begins on the gas side with a third mixed gas/steam turbine group 29, downstream of which is a third waste-heat boiler 30. This waste-heat boiler exhibits a superheater 31, an intermediate-pressure section 32 and a low-pressure section 33. The spent steam of the second back-pressure turbine 28 and the steam from the intermediate-pressure section 13' are superheated in the superheater 31 and conveyed to the combustion chamber 34 of the third mixed gas/steam turbine group 29. There also, the steam for cooling the combustion chamber is utilized in a nearly stoichiometric combustion and is expanded in a mixed gas/steam turbine 35 of the third mixed gas/steam turbine group 29, together with the combustion off-gas formed in the combustion chamber 34, to a pressure lying slightly above atmospheric pressure, so that the stack-gas-side pressure losses of the third waste-heat boiler 30 can be compensated.
The condensing steam turbine 16' serves as the fourth process stage. This turbine has various steam inlets for the various pressure levels of the individual steam streams. As a general rule, the steam from the intermediate-pressure section 32 of the third waste-heat boiler 30 will exhibit the highest pressure, while the pressure of the steam streams from the low-pressure section 19, the low-pressure section 23 and the low-pressure section 33 is lower. The low-pressure section 23 can be arranged in a way comparable to what was described for the low-pressure section 19. After the expansion of the steam in the condensing steam turbine 16', the steam is condensed in the condenser 17'.
An advantageous development of the invention, which is, however, not illustrated, consists in that the third process stage is effected by provision of a third gas/steam mixed turbine group with interheating. All that has to be done here is to adapt the pressure level of the spent steam of the second back-pressure turbine 28 to the pressure of the high-pressure combustion chamber and to adapt the pressure of the intermediate-pressure section 13' to the pressure of the low-pressure combustion chamber. In this way, further process stages can be implemented similarly to a "zipper" system. The closure of the chain is formed by the third waste-heat boiler 30 and the condensing steam turbine 16' with condenser 17'.
If there is a need for process heat or district heating, the low-pressure sections 19, 23 and 33 can be adapted and/or omitted in such a way that the off-gas streams of the waste-heat boilers 5', 11' and 30 are employed for extracting these quantities of available heat. The condensing turbine 16' can then be designed as a back-pressure turbine and/or the condenser 17' can be designed as a heating condenser. 1
An advantageous embodiment of the invention consists in that the combustion chambers 3, 14, 20, 34 of the gas turbines are replaced by high-temperature fuel cell modules, so as to serve as heat sources for the gas turbines. The efficiency of the facility is enhanced in this way. | A power plant facility having gas turbines, steam turbines and mixed gas/steam turbines. By use of appropriate networking of the three turbine facilities, an approach to isothermal heat supply and removal is achieved with optimal utilization of waste heat. | 5 |
BACKGROUND OF THE INVENTION 1. Field Of The Invention
The invention relates to a process for the production of 4-amino-2-chloro-5-cyano-6-(methylthio)pyrimidine (I) of the formula: ##STR1## wherein 2-chloropyrimidines are intermediate products for the synthesis of 2-aminopyrimidines, a class of substances which contains numerous effective pesticides. 2. Background Art
An important representative of the 2-chloropyrimidines is 4-amino-2-chloro-5-cyano-6-(methylthio)pyrimidine, whose methylthio group can be nucleophilically exchanged optionally after oxidation to the methanesulfonyl group [European Published Patent Application No. 0244360].
The known process for the production of 4-amino-2-chloro-5-cyano-6-(methylthio)pyrimidine [H. Kristinsson, J. Chem. Soc. Chem. Commun., (1974), page 350] starts from cyanamide and carbon disulfide, which with potassium hydroxide yield the dipotassium salt of cyanimidodithiocarbonic acid [A. Hantzsch and M. Wolvekamp, Justus Liebigs Ann. Chem., Vol. 331, (1904), page 282]. This is reacted with dimethyl sulfate to dimethyl cyanimidedithiocarbonate which adds malononitrile in the presence of sodium methylate. By adding hydrochloric acid the addition product is cyclized to the corresponding pyrimidine. In this way, not only the desired product results but also the isomeric 2-amino-4-chloro-5-cyano-6-(methylthio)pyrimidine, namely in the ratio of 3:2 (2-amino/4-amino-) so that with a total yield of 88 percent, the effective yield is only about 35 percent.
BROAD DESCRIPTION OF THE INVENTION
The main object of the invention is to provide a process which results in a high yield of 4-amino-2-chloro-5-cyano-6-(methylthio)pyrimidine and only small amounts of by-products. Other objects and advantages of the invention are set out herein or are obvious herefrom to one skilled in the art.
The objects and advantages of the invention are achieved by the process of the invention.
The invention involves a process for the production of 4-amino-2-chloro-5-cyano-6-(methylthio)pyrimidine of the formula: ##STR2## In a first step, malononitrile is reacted with carbon disulfide in the presence of a strong base to a dianion of dicyanodithioacetic acid of the formula: ##STR3## The latter then is methylated with a methylating agent to dicyanoketene dimethyl thioacetal of the formula: ##STR4## The latter is condensed with cyanamide in the presence of a base to the anion of 2-cyano-3-cyanamino-3-methylthio-acrylonitrile of the formula: ##STR5## The latter is cyclized in the presence of hydrochloric acid to 4-amino-2-chloro-5-cyano-6-(methylthio)pyrimidine.
Preferably an alkali alcoholate each is used as the base. Preferably in each case the corresponding alcohol is used as solvent in the reactions in the presence of alkali alcoholate. Preferably sodium ethylate is used as the alkali alcoholate. Preferably, in the reaction of malononitrile with the carbon disulfide, the malononitrile is introduced with an equivalent of base and the carbon disulfide is added synchronously with a second equivalent of base. Preferably dimethyl sulfate is used as the methylating agent. Preferably the hydrogen chloride is used as aqueous hydrochloric acid.
DETAILED DESCRIPTION OF THE INVENTION
It was found that surprisingly, 4-amino-2-chloro-5-cyano-6-(methylthio)pyrimidine can be obtained in a very good yield and practically free of by-products, by first reacting the malononitrile with carbon disulfide and an alkali-alcoholate to the corresponding dialkali salt of dicyanodithioacetic acid of the formula: ##STR6## and then converting it with a methylating agent, for example, dimethyl sulfate, into the dicyanoketene dimethyl thioacetal of the formula: ##STR7## The latter is condensed with cyanamide in the presence of a base to the anion of the corresponding dicyanoketene S,N-acetal of the formula: ##STR8## which is cyclized to the target compound analogously to the known process in the presence of hydrochloric acid.
The first part of the synthesis up to dicyanoketene dimethyl thioacetal is known in the art [R. Gompper and W. Topfl, Chem. Ber., Vol. 95, (1962), pages 2861 to 2870 ]. The yield according to the literature (68 percent) can also be markedly increased, when first the anion is formed from the introduced malonitriles with an equivalent of base and the carbon disulfide is added simultaneously with the second equivalent of base instead of carbon disulfide and base being alternately added in portions.
As the base for the condensation of the dimethyl mercaptal with cyanamide, an alkali alcoholate is preferably used. Especially preferred are sodium alcoholates, especially sodium ethylate. However, other bases, for example, alkali hydroxides, can be used.
The condensation is performed suitably in a polar solvent, for example, in a lower alcohol. If an alcoholate is used as the base, the corresponding alcohol is preferably used as the solvent, for example, ethanol with sodium ethylate as the base. With the use of hydroxides or weaker bases, water or an aqueous solvent mixture can also be used.
The condensation is performed preferably at approximately ambient temperature so that neither heating nor cooling is required, i.e., approximately in the range of 10° to 40° C.
After distilling off the solvent, the reaction product of formula IV is advantageously mixed without purification with hydrochloric acid and cyclized. Hydrogen chloride is prefereably used in the form of aqueous hydrochloric acid, especially preferred in a concentration of 4 to 8M. Also the cyclization can be performed in the ambient temperature range without special temperature control measures.
The following examples illustrate the performance of the process according to the invention.
EXAMPLE 1
Dicyanoketene Dimethyl Thioacetal
To a sodium methylate solution of 2.3 g (0.1 mol) of sodium and 41 g of ethanol, 6.6 g (0.1 mol) of malononitrile (melted) was instilled under exclusion of moisture within 5 minutes at room temperature with stirring and then stirred for another 5 minutes at room temperature. The resultant suspension was cooled to 15° C. and, at this temperature, solutions of 7.6 g (0.1 mol) of carbon disulfide in 36 g of ethanol and 2.3 g (0.1 mol) of sodium in 41 g of ethanol were added within 60 minutes from two injection syringes operated synchronously. During the addition, a clear yellow-green solution formed, which was stirred for another 60 minutes. Then 26.5 g (0.21 mol) of dimethyl sulfate from a dropping funnel was added within 30 minutes with stirring. The temperature rose in this connection and was held at 20° C. by cooling. A yellow suspension resulted, which was stirred another 4 hours at 20° C. and then poured with stirring in 400 g of ice water. The aqueous ethanolic suspension was stirred for 2 hours more at room temperature for the decomposition of excess dimethyl sulfate,cooled to 5° C. and filtered. The filter cake was washed with a little water and dried at room temperature in a vacuum. There was a yield of 14.1 g of yellowish crystal with a content (HPLC) of 99.9 percent (83 percent of theory, relative to malononitrile.
The product had a melting point of 78° to 79.5° C. (Lit. 81° C.)
EXAMPLE 2
4-Amino-2-chloro-5-cyano-6-(methylthio)pyrimidine
A sodium methylate solution was produced from 0.23 g of sodium (10 mmol) and 25 ml of ethanol. 0.42 g of cyanamide (10 mmol) was dissolved in it and<then 1.70 g of dicyanoketene dimethyl thioacetal (10 mmol) was added. The yellowish suspension which formed was stirred 1 hour at 20° C. and then evaporated to dryness. A mixture of 20 ml of concentrated hydrochloric acid and 12 ml of water was added to the residue (1.98 g of yellow powder) at O° C. within 15 minutes. The resultant yellowish suspension was stirred another 20 hours at room temperature. The solid product was filtered off , washed with a little water, suspended in 60 ml of 10 percent sodium carbonate solution, again filtered off and washed with water. Finally the product was dried at 30° C./30 mbar. There was a yield of 1.95 g of yellowish power with a content (GC) of 96 percent (93 percent of theory). The product had a melting point of about 268° C. | 4-Amino-2-chloro-5-cyano-6-(methylthio)primidine is produced from dicyanoketene dimethyl thioacetal and cyanamide by condensation in the presence of a base and subsequent cyclization in the presence of hydrochloric acid. The dicyanoketenedimeth thioacetal is available by reaction of malononitrile, with carbon disulfide and a base and subsequent methylation with dimethyl sulfate. The reaction sequence yields the pyrimidine derivative in good yield and practically free of by-products. | 2 |
[0001] This invention relates to an improved hand tool and to an improved multibit folding screwdriver tool; and more particularly to a hex key tool having in addition to a set of conventional hex keys, a 4-in-1 or 8-in-1 driver tool, such as disclosed in our copending U.S. patent applications, Ser. Nos. 08/451,398, filed May 26, 1995, and 08/620,471, filed Mar. 22, 1996, both of which are intended to be and are hereby incorporated herein by reference. Also, this application relates to our copending U.S. patent application, entitled “Improved Hand/Survival Tool Having Multiple Implements” Ser. No. (not yet known), filed concurrently with the instant patent application on Aug. 1, 1997.
BACKGROUND OF THE INVENTION
[0002] Heretofore, hex key tools made and sold by various well-known manufacturers, such as Allen, a Daneher Tool Group of West Hartford, Conn. 06110, comprise either a set of loose hex keys in a pouch, or a set of hex keys pivotably mounted on one or both ends of a small handle, whereby the hex keys are stored between the sides of a handle, and individually pivoted outwardly to be used either in a right angle position or in an extending position axially aligned with the longitudinal axis of the handle. Other fold-up hex key sets include at most two or three separately pivoted screwdriver blades, such as a slotted blade and a Phillips type screwdriver. While such conventional tools are handy, they have limited use and do not have multiple drive bits of different shapes and/or sizes or one or more pivoted drive tools embodying an outer sleeve and an inner sleeve removably fixed relative thereto, and having therein replaceable drive bits for torquing fasteners or nuts.
SUMMARY OF THE INVENTION
[0003] The improved hand tool of the invention incorporates with or without a hex key set, a 4-in-1 or 8-in-1 driver tool which is pivotable at an end of the tool handle. With such a driver tool and its multiple drive bits, removably secured to mateable drive sleeves, the tool of the present invention enables a collection of various sizes and types of drive bits, such as Phillips, flat, star, etc., to be immediately available to the user of such tool, thereby eliminating the need for seeking out a different tool. Mechanics, machinists and other tradespeople, as well as “do-it-yourselfers,” have a clear need for such improved hand tool since it eliminates having to have in hand on any job multiple tools of various sizes and types, and contributes to saving space in one's toolbox, besides being of economic benefit in that fewer overall tools need be purchased by the user. In addition, other pivotable tools, such as a flashlight and/or telescoping magnetic pick-up may also be employed in the practice of the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0004] [0004]FIG. 1 is a side elevational view, partly broken away, of the improved hex key hand tool of the present invention with various sized hex keys pivoted to both ends of the tool handle, and with a 4-in-1 driver tool pivotably mounted at one end thereof.
[0005] [0005]FIG. 2 is a plan view looking into the cavity/compartment of the improved hand tool of FIG. 1, but with the 4-in-1 driver tool, and all of the set of hex keys, shown in the stored condition, except for the set of hex keys grouped at one end which keys are shown extending downwardly out of view, but at right angles to the handle.
[0006] [0006]FIG. 3 is another embodiment of the improved hex key hand tool shown in a side elevational view, partly in section, but with a formed cut-away handle allowing for an improved grip by the user's fingers, and for a bigger/wider bit holder, with all hex keys and the 4-in-1 driver tool, at opposite ends of the tool handle, and with a conventional U-shaped loop for use in handing the tool on a peg or chain.
[0007] [0007]FIG. 4 is a side-elevational view, similar to that of FIG. 3, and also partly in section, but showing the hex keys pivoted out of the way for access to the 4-in-1 driver tool.
[0008] [0008]FIG. 5 is a side elevational view partly in section of the hex key hand tool of FIGS. 3 and 4, but showing the 4-in-1 driver tool in its fully extended operative position.
[0009] [0009]FIG. 6 is an alternative embodiment of the improved hex key hand tool of FIGS. 1 and 2, but with an additional pivotable tool, such as a small flashlight.
[0010] [0010]FIG. 7 is a plan view of the embodiment in FIG. 6 showing the 4-in-1 driver tool fully extended alongside the flashlight, and with one hex key at the opposite end fully extended outwardly with all other hex keys extended downwardly at right angles thereto with the cavity/compartment of the handle shown empty.
[0011] [0011]FIG. 8 is a plan view, similar to that of FIG. 7, but showing the 4-in-1 driver tool and flashlight in the stored position, with the set of hex keys extending downwardly at right angles to the handle for ease of illustration.
[0012] FIGS. 9 - 11 show a couple of alternate 8-in-1 pocket drive tools, with FIG. 9 showing in plan view, and partly in section, a pair of 4-in-1 drive tools offset from each other at opposite pivot axes of the handle. FIG. 10 illustrates a longitudinal section showing a pair of 4-in-1 drive tools axially in line with the longitudinal axis of the handle, but with one of the drive tools stored and the other ready for use; and FIG. 11 shows both 4-in-1 drive tools stored between the side walls of the handle.
[0013] [0013]FIGS. 12 and 13 is another modification of the improved hand tool with a set of hex keys pivotable at one end, and a 4-in-1 hand tool pivotable at the opposite end of the handle and with an adjacent telescoping magnetic pick-up for use in seeking out “loose” fasteners/nuts, etc.
[0014] [0014]FIGS. 14 and 15 are views similar to that of FIGS. 3 - 5 , but with a “closed-type” cutout handle, and a pivotable 4-in-1 hand tool at one end thereof.
[0015] [0015]FIGS. 16 and 17 are views similar to that of FIGS. 14 and 15, but showing an 8-in-1 hand tool (in lieu of a 4-in-1 hand tool); and
[0016] FIGS. 18 - 20 are views similar to that of FIGS. 16 and 17, except that the 8-in-1 (or 4-in-1 if desired) drive tool is also provided with one or more crossbores for torquing the hexagonal sleeves or drive bits using the handle as a lever arm.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] With reference to FIGS. 1 - 20 and in particular FIGS. 1 and 2, there is shown a hex key set 10 pivotably mounted on axes 11 , suitably, at the ends of a pair of side bolsters or at opposite ends of an integrally formed one-piece handle 12 . In the improved hex key hand tool of the invention, a 4-in-1 (or 8-in-1) drive tool is suitably pivotably connected at one end of an outer sleeve 14 , with a removably mounted inner sleeve 16 having a pair of drive bits 18 and 20 removably retained in place by conventional biasable ball detent means, with only balls shown on the flat planar hex surfaces. Other suitable securing means, which are well known, include magnets, retaining clips, mating grooves and protrusions (ears or wings), may likewise be employed in lieu of the biasable ball detent means. The innards of the inner sleeve 16 comprise hexagonal bores which drive the hexagonal drive bits 18 or 20 ; and the inner sleeve 16 is also suitably connected in any conventional, removable manner, while enabling rotational transmission of torque between the inner and outer sleeves. Such well-known drive rotation connections, for example, may comprise a pair of opposite grooves (not shown) on the inner wall of the outer sleeve 14 , and a mateable pair of ears (not shown) on the outer wall of the inner sleeve 16 as described hereinabove with respect to the connection between the drive bits and the inner sleeve. Alternatively, mating hexagonal elements may be used to transfer driving forces from one element or sleeve to another element or sleeve. Also, as noted herein, other more conventional means, such as the biasable ball detents, magnets, retaining clips, mating grooves and protrusions or wings (ears), etc., may be used to retain in place the drive bits in the inner sleeve and the inner sleeve in the outer sleeve, so that such elements cannot fall out or be dislodged during use.
[0018] Also shown for use with the embodiments of the improved hex key hand tool of the invention is a hexagonal crossbore 17 in the handle and side 12 where the sidewall is of a single thickness. Where a laminate of two materials are employed (see lines in phantom), dual crossbores are employed to engage both the hex drive bit and the hexagonal outer surface of the inner sleeve (not shown). Such crossbore(s) enable the tool to be used as a “T-handle” drive tool. In addition, the pivotable drive tool is preferably suitably locked in the fully extended, open, longitudinal position (or even in the right angle position or both, if desired) by any of the well known and conventional means for locking a tool or “knife blade” in place so that it cannot swing back into the closed, stored position.
[0019] It will be appreciated that a pair of 4-in-1 drive tools can be used in one end or at opposite ends of the hex key tool handle. Alternatively, in lieu of a pair of 4-in-1 drive tools, a “single” 8-in-1 drive tool could be employed, such as that disclosed in our copending U.S. patent application. Ser. No. 08/620,471, filed Mar. 22, 1996, the contents of which is intended to and is hereby incorporated herein by reference. Such an 8-in-1 drive tool would, however generally increase the length and width of the hex key tool handle to a size which would be bigger than that of a conventional hex key tool depending upon the length and diameter of the drive bits. The only difference is that a pair of inner or servant sleeves would mate with a single master sleeve, with each of the inner or servant sleeves having a pair of drive bits and with the master sleeve mating similarly with the outer sleeve. In this connection, the drive bits may be either of the male or female types, so that both regular fasteners can be driven/undriven, and also nuts (hexagonal and the like) likewise driven to a tight condition or loosened by the various hexagon tubular-like elements (bores of the inner or servant sleeves and the master bore(s) in the master sleeve and/or pivotable sleeve itself).
[0020] FIGS. 3 - 5 , while similar to that of FIGS. 1 and 2, embody essentially an “open” cavity in a one-piece, integrally constructed handle 30 . Such open cavity facilitates access to the hex keels and/or other tool implements pivotably mounted to the handle 30 . The handle 30 is further provided with a conventional U-shaped loop 32 for storing of the tool on a peg or other hook, as well as for securing the tool on a chain.
[0021] In FIGS. 6 - 8 , which show an embodiment similar to that of FIGS. 1 and 2, there is shown the addition of a small flashlight 22 (battery operated—not shown) pivotably mounted to the handle 12 ′ about axis 11 ′. Such a flashlight tool feature is convenient, and very handy, especially where the tool may be used in close dark quarters having little light source.
[0022] The improved hex key tool of the present invention provides a new tool having generally in the same single place a plurality of drive tool bits, in lieu of a plurality of separately pivoted tool blades, such as flat type, Phillips, Torx or star, pin type, etc., all of which individually take up considerable space as each only performs a single type of function, be it driving a slotted screw, Phillips head screw or other type of fastener.
[0023] Preferably, the 4-in-1 or 8-in-1 driver tool element should not normally be offset, and is centered in the tool handle so that its axis is generally in line with the rotational tool handle axis.
[0024] As shown in FIGS. 9 - 11 , handle 12 ′ with a pair of sides and pivot axes at opposite ends pivotably supports a pair of 4-in-1 drive tools with dual drive bits of varying styles and sizes releasably secured in a conventional manner, and preferably to a hexagonal inner sleeve 16 ′ which is pivotably mounted about the oppositely disposed pivot axes by means of the outer sleeves 14 ′. Here the 4-in-1 drive tools are offset from each other to minimize the length of the tool handle, as if the pair of 4-in-1 drive tools were in the line with each other along the longitudinal axis of the handle, the tool handle would normally be twice as long.
[0025] Where it is preferred to have in-line “pressing-rotational” forces always acting along and about the drive tool axis (without any “eccentric” effect), the dual 4-in-1 hand tools may be disposed directly in line axially as shown in FIGS. 10 - 11 , but here the dual 4-in-1 hand tools are stored obliquely inside the handle cavity or compartment (between the side walls). With this arrangement, the handle length is basically of the same length as the tool handle of FIG. 9.
[0026] Referring now to FIGS. 12 - 13 , the improved hand tool is shown with a set of pivotable hex keys at one end and with a pivotable 4-in-1 hand tool like that of FIGS. 1 - 2 and 9 , and also with a telescoping element 36 having magnet means 38 suitably secured at the distal end of the telescoping sections, such as powerful disc magnets which are well known and conventional. This device is a very handy tool for facilitating the easy pick up of “loose” metal fasteners, nuts, or the like which are lost during assembly/disassembly of an apparatus, vehicle, etc., and have dropped into small crevices or other areas inaccessible to one's fingers.
[0027] In FIGS. 14 - 17 simply show the improved hand tool without a set of hex keys, with FIGS. 14 - 15 illustrating the 4-in-1 hand tool foldable into the handle cavity/compartment, and FIGS. 16 - 17 illustrating the 8-in-1 hand tool foldable into the handle cavity. It will be appreciated that the tool handles of both embodiments may be generally of the same length as the length of improved hand tools of the invention are all primarily dependent upon the particular length and diameter of the drive bits, both of which can be varied to accommodate a particular sized pocket hand tool or other type drive tool.
[0028] FIGS. 18 - 20 are similar to that of FIGS. 16 - 17 , but showing the 8-in-1 drive tool with the outer “master” sleeve 40 to send its inner “servant” sleeves 42 (each having a pair of drive bits of varying styles and/or sizes) removed from the pivotable sleeve 44 shown seated in the cavity/compartment of the handle in its stored position (but without the sleeve elements and their drive bits). Here all of the sleeve elements ( 40 and 42 and the interior of the pivoted sleeve 44 are polygonal in shape, but preferably hexagonal as shown (in lieu of other type “rotatable connection,” such as the conventional mating grooves and protruding wings/ears.
[0029] Also shown in FIGS. 18 and 20 are crossbores 46 and 48 , the former of a size to mate with the inner “servant” sleeves 42 , and the latter to mate with the hexagonal drive bits (not shown in either of the hex holes 48 of the figures). Crossbore 50 in FIG. 20 is shown mated with the larger outer “master” sleeve 40 . With this embodiment, one obtains the lever arm advantage of the handle in achieving higher torquing power.
[0030] Although the present invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will of course be understood that various changes and modifications may be made in the form, details and arrangements of the parts without departing from the scope of the invention as set forth in the following claims. | A pocket hand tool has tow opposing sleeves which are pivotally connected to opposite ends of a new pocket tool handle. Each sleeve slidably receives interchangeable tool bits. The sleeves are selectively pivoted from an inoperable position within the handle to an operable position disposed away from the handle. | 1 |
FIELD OF THE INVENTION
This invention relates to heterogeneous elastomeric blends having improved rheological properties of a major portion of a neutralized sulfonated elastomeric polymer with a minor portion of a polystyrene thermoplastic resin or a neutralized sulfonated polystyrene resin and mixtures thereof. Both the sulfonated elastomeric polymer and the sulfonated thermoplastic resin have about 0.2 to about 10.0 mole percent of SO 3 H groups, at least 90% of which are neutralized with an organic amine.
BACKGROUND OF THE PRIOR ART
U.S. Pat. No. 3,642,728, herein incorporated by reference, teaches a new class of sulfonated polymers which are derived from polymers containing olefinic unsaturation, especially elastomeric polymers, e.g. butyl and ethylene-propylene terpolymers. These materials may be neutralized with organic amines or basic materials selected from Groups I, II, III, IV, V, VI-B, VII-B and VIII and mixtures thereof of the Periodic Table of Elements. These materials, especially the butyl and the ethylene-propylene terpolymer (EPDM) derivatives, may broadly be classified as thermoelastomers, that is these materials may be processed at high temperatures by use of shear force in the presence of selected polar additives and yet at the temperature of use, e.g. room temperature, the materials, through the association of the sulfonate group behave as cross-linked elastomers. Thus, these materials represent one form of reprocessable elastomers, which are very desirable in industry.
However, although these materials are commercially useful, the melt viscosity even at very high temperature tends to be sufficiently high as to preclude the use of conventional plastic fabrication techniques. Thus, the very purpose for which these compounds are derived is not adequately fulfilled. In this invention, it has unexpectedly been discovered that decreased melt viscosity may be obtained by combining these polymers with a minor portion of a polystyrene thermoplastic resin or a sulfonated polystyrene in a heterogeneous polymer blend. Further, it has been unexpectedly discovered that the tensile properties of these blends, as measured at room temperature, can be substantially improved as compared to the sulfonated elastomers alone.
The sulfonated elastomers described in U.S. Pat. No. 3,647,728, herein incorporated by reference, when used as gums possess a relatively low level of rigidity or stiffness which yields rather limp materials incapable of supporting themselves when prepared in thin sections. This is a major limitation, if one desires to prepare dimensionally stable parts, e.g. automotive or appliance applications. It is known in the art that stiffness of elastomers may be increased by the combination of carbon black or inorganic material such as clays, calcium carbonate or silicates, etc. However, these materials, while increasing the hardness, further deteriorate the melt viscosity of the above-described ionic elastomers. Thus, systems which at best have borderline processability even at very low metal sulfonate levels further deteriorate in their flow behavior and thus cannot be processed at all. It has unexpectedly been discovered that in the compositions of the instant invention, wherein minor amounts of the unsulfonated or sulfonated polystyrene are combined with the sulfonated elastomers described above, result in increased tensile modulus at room temperature.
Thus, this invention teaches compositions of matter which represent significant improvement over the prior art in that low melt viscosity is obtained at no loss in tensile properties.
The present application is related to two other filed application Ser. Nos. 514,502, now U.S. Pat. No. 3905586 and 514,512, now U.S. Pat. No. 3923370, herein incorporated by reference. These two applications, which have issued, are related to elastomeric blends of a crystalline polyolefinic resin and a neutralized sulfonated elastomeric blends. These blends are of a homogeneous nature, wherein the crystalline polyolefinic resin appears completely soluble in the sulfonated elastomeric polymer at elevated temperatures. The melt rheology and tensile properties of these homogeneous blends are improved as compared to the unmodified sulfonated elastomeric polymer due to the plasticization of the polymeric backbone of the elastomeric polymer. However, the blending of an inorganic filler with neutralized sulfonated elastomeric polymer creates a heterogeneous blend, wherein the rheological and physical properties are adversely affected due to incomplete interfacial bonding between the inorganic particles and the elastomeric matrix. Blends of a neutralized sulfonated elastomeric polymer and a polystyrene thermoplastic resin or a sulfonated polystyrene thermoplastic resin, wherein the thermoplastic resin is at a concentration level in excess of 20 parts per hundred by weight based on 100 parts of the neutralized sulfonated elastomeric polymer, exhibit a general deterioration in physical properties due to the manifestation of gross incompatibility. Surprisingly, it has been found that the incorporation of the polystyrene or sulfonated polystyrene at a concentration level of below about 20 parts per hundred by weight results in compositions exhibiting both improved physical and rheological properties.
SUMMARY OF THE INVENTION
It has been unexpectedly discovered that novel elastomeric heterogeneous blend compositions comprising a major portion of a sulfonated elastomeric polymer having at least 90% of the SO 3 H groups combined with an organic amine and a minor portion of a polystyrene thermoplastic resin or a neutralized sulfonated polystyrene and mixtures thereof show unexpectedly improved melt viscosity properties and improved room temperature physical properties (as compared to the sulfonated elastomer) itself. More particularly, the sulfonated elastomer is derived from an EPDM terpolymer (i.e., a terpolymer of ethylene, propylene, and a small amount, e.g., <10 mole % of a diene monomer).
Accordingly, it is an object of my present invention to provide elastomeric heterogeneous blend compositions of a neutralized sulfonated elastomeric polymer and a polystyrene thermoplastic resin or a sulfonated polystyrene, wherein these heterogeneous blend compositions have both improved physical and rheological properties as compared to the unmodified neutralized sulfonated elastomeric polymer.
A further object of my present invention is to provide a unique and novel process for the formation of these elastomeric heterogeneous blend compositions having improved physical and rheological properties.
GENERAL DESCRIPTION OF THE INVENTION
This present invention relates to unique and novel heterogeneous blend compositions of a neutralized sulfonated elastomeric polymer and a polystyrene thermoplastic resin or a sulfonated polystyrene, wherein the polystyrene is microdispersed as discrete particles in the neutralized sulfonated elastomeric polymer matrix. These heterogeneous blend compositions exhibit improved physical and rheological properties thereby permitting these heterogeneous blend compositions to be processed by conventional plastic fabricating techniques such as injection molding or extrusion.
Various chemical additives can be incorporated into the heterogeneous blend compositions for modification of a particular physical property.
The EPDM terpolymers are low unsaturated polymers having about 0.1 to about 10 mole % olefinic unsaturation defined according to the definition as found in ASTM-D-1418-64 and is intended to mean terpolymers containing ethylene and propylene in the backbone and a diene in the side chain. Illustrative methods for producing these terpolymers are found in U.S. Pat. No. 3,280,082, British Pat. No. 1,030,289 and French Pat. No. 1,386,600, which are incorporated herein by reference. The preferred polymers contain about 40 to about 80 wt. % ethylene and about 1 to about 10 wt. % of a diene monomer, the balance of the polymer being propylene. Preferably the polymer contains about 50 to about 60 wt. % ethylene, e.g. 50 wt. % and about 2.6 to about 9.0 wt. % diene monomer, e.g. 5.0 wt. %. The diene monomer is preferably a nonconjugated diene.
Illustrative of these nonconjugated diene monomers which may be used in the terpolymer (EPDM) are 1,4 hexadiene, dicyclopentadiene, ethylidene norbornene, methylene norbornene, propenyl norbornene, and methyl tetrahydroindene. The EPDM terpolymer has a number average molecular weight of about 10,000 to about 200,000, more preferably of about 15,000 to about 100,000, most preferably of about 20,000 to about 60,000. The Mooney viscosity of the EPDM terpolymer at (1+8) min. at 212° F. is about 5 to about 90, more preferably about 10 to about 50, most preferably about 15 to about 25. The Mv of the EPDM terpolymer is preferably below about 350,000 and more preferably below about 300,000. The Mw of the EPDM terpolymer is preferably below about 500,000 and more preferably below about 350,000.
A typical EPDM terpolymer is Vistalon 3708 (Exxon Chemical Co.). Vistalon 3708 is a terpolymer having a Mooney viscosity at (1+8) min. at 212° F. of about 45-55 and having about 64 wt. % ethylene, about 3.3 wt. % of 5-ethylidene-2-norbornene, and having about 53 wt. % of ethylene, about 3.5 wt. % of 1,4 hexadiene, and about 43.5 wt. % of propylene.
The polystyrene thermoplastic resins of the present invention are selected from the group consisting essentially of polystyrene, poly-t-butyl-styrene, polychlorostyrene, polyalpha methyl styrene or co- or terpolymers of the aforementioned with acrylonitrile or vinyl toluene.
The polystyrene thermoplastics suitable for use in the practice of the invention have a glass transition temperature from about 90° C. to about 150° C., more preferably about 90° C. to about 140° C. and most preferably about 90° C. to about 120° C. These polystyrene resins have a weight average molecular weight of about 5,000 to about 500,000, more preferably about 20,000 to about 350,000 and most preferably about 90,000 to about 300,000. These base polystyrene thermoplastic resins can be prepared directly by any of the known polymerization processes. The term "thermoplastic" is used in its conventional sense to mean a substantially rigid (flexus modulus >10,000 psi) material capable of retaining the ability to flow at elevated temperatures for relatively long times.
The preferred polystyrene thermoplastic resin is a homopolymer of styrene having a number average molecular weight of about 180,000, and an intrinsic viscosity in toluene of about 0.8. These polymers are widely available commercially in large volume. A suitable material is Dow Polystyrene 666 which affords a suitable molecular weight.
In carrying out the invention, the EPDM terpolymer or the polystyrene thermoplastic resin is dissolved in a nonreactive solvent such as chlorinated aromatic hydrocarbon, a chlorinated aliphatic hydrocarbon, an aromatic hydrocarbon, of an aliphatic hydrocarbon such as chlorobenzene, benzene, toluene, xylene, cyclohexane, pentane, hexane, or heptane. The preferred solvents is carbon tetrachloride for both the EPDM terpolymer and the polystyrene thermoplastic resin. A sulfonating agent is added to the solution of the EPDM terpolymer and nonreactive solvent at a temperature of about -100° C. to about 100° C. for a period of time of about 5 to about 60 minutes, more preferably at room temperature for 45 minutes, and most preferably at room temperature for 30 minutes. Typical sulfonating agents are described in U.S. Pat. Nos. 3,642,728 and 3,836,511, incorporated herein by reference. These sulfonating agents are selected from an acyl sulfate, a mixture of sulfuric acid and an acid anhydride of a complex of a sulfur trioxide donor and a Lewis base containing oxygen, nitrogen, or phosphorous. Typical sulfur trioxide donors are SO 3 , chlorosulfonic acid, fluorosulfonic acid, sulfuric acid, oleum, etc. Typical Lewis bases are: dioxane, tetrahydrofuran, phosphorous acid, phosphonic acid, triethylphosphate, trimethylamine, or piperidine. The most preferred sulfonation agent for the polystyrene thermoplastic is an acyl sulfate selected from the group consisting essentially of benzoyl, acetyl, propionyl or butyryl acetate. The acyl sulfate can be formed in situ in the reaction medium or pregenerated before its addition to the reaction medium. A preferred acyl sulfate is acetyl sulfate. The most preferred sulfonation agent for the EPDM terpolymer is a complex of sulfur trioxide and dioxane. It should be pointed out that neither the sulfonating agent nor the manner of sulfonation is critical, provided that the sulfonating method does not degrade the polymeric backbone. The reaction is quenched with an aliphatic alcohol being selected from methanol, ethanol, n-propanol or isopropanol, with an aromatic phenol, or with water. The acid form of the sulfonated EPDM terpolymer a polystyrene thermoplastic resin has about 10 to about 100 meq. of SO 3 H groups per 100 grams of polymer, more preferably about 15 to about 40; and most preferably about 20 to about 35. The mole percent of SO 3 H groups is about 0.2 to about 20, more preferably about 0.2 to about 10.0. The meq. of SO 3 H/100 grams of polymer was determined by both titration of the polymeric sulfonic acid and Dietert Sulfur analysis. In the titration of the sulfonic acid the polymer was dissolved in a solvent consisting of 95 parts of toluene and 5 parts of methanol at a concentration level of 50 grams per liter of solvent. The acid form is titrated with ethanolic sodium hydroxide to an Alizarin Thymolphthalein endpoint.
The solution of the acid form of the sulfonated EPDM terpolymer and the sulfonated polystyrene thermoplastic resin are mixed together and neutralized with a neutralizing agent. Neutralization of the acid forms of the sulfonated EPDM terpolymer and the sulfonated polystyrene thermoplastic resin is done by the addition of an organic amine to form an amine salt.
The organic amines used to form the ionic bonds can be primary, secondary, or tertiary amines, wherein the organic radicals are C 1 to C 30 alkyl, phenyl, aralkyl or alkaryl. More preferably, the organic radical is a phenyl, C 1 to C 10 alkyl, C 7 to C 10 alkylaryl or C 7 to C 10 aralkyl. Illustrative of such amines are anhydrous piperazine, triethylamine, tri-n-propylamine and tetraethylene-pentamine, piperazine and tri-n-propylamine.
Guanidines are preferred neutralizing agents for the sulfonic acid groups to produce ionic sites. The preferred guanidines are guanidine or substituted guanidines, wherein the substituent organic radicals are C 1 to C 30 alkyl, phenyl, aralkyl, or alkaryl. Illustrative of such guanidines are tetra-methyl guanidine, di-phenyl guanidine and di-ortho-tolyl guanidine.
The preferred neutralizing agent for the acid forms of the sulfonated EPDM terpolymer and sulfonated polystyrene thermoplastic resin is di-ortho-tolyl guanidine (DOTG). Sufficient meq. of the metal salt of the carboxylic acid or the organic amine are added to the solution of the acid forms of the sulfonated EPDM terpolymer and the sulfonated polystyrene thermoplastic to effect at least about 1 to about 100% neutralization of the acid groups, more preferably about 50 to about 100%, and most preferably about 90 to about 100%.
The mixture of the neutralized sulfonated EPDM terpolymer and the neutralized sulfonated polystyrene thermoplastic resin is isolated from solution by steam stripping to give a heterogeneous blend of the neutralized sulfonated polystyrene microdispersed in the neutralized sulfonated elastomeric polymer.
Alternatively, a polystyrene dissolved in the carbon tetrachloride resin can be added to the solution of the acid form of the sulfonated elastomeric polymer. The DOTG is added to the solution to neutralize the acid form of sulfonated elastomeric polymer. The mixture of the polystyrene thermoplastic resin and the neutralized sulfonated elastomeric polymer are isolated from solution by steam stripping to give a heterogeneous blend of the polystyrene thermoplastic resin microdispersed in the neutralized sulfonated elastomeric polymer.
In order to maximize the compatability of the polystyrene or sulfonated polystyrene into the neutralized sulfonated elastomeric polymer, it is necessary to employ a solution process. Intensive mixing process such as a Banbury extruder or a two-roll mill results in compositions, wherein the physical and rheological properties have not been maximized.
The polystyrene thermoplastic resin or the sulfonated polystyrene is a minor proportion of the heterogeneous blend at a concentration level of about 1 to about 20 parts per hundred based on 100 parts of the neutralized sulfonated elastomeric polymer, more preferably about 2 to about 15; and most preferably about 3 to about 10.
Various chemical additives can be incorporated in the blend such as fillers and oils. These chemical additives are incorporated into the heterogeneous elastomeric blend by a conventional dry blend two-roll mill technique, or by a conventional intensive mixing process such as a high steam batch Banbury or a continuous twin screw extruder. The concentration level of these additives is from about 25 to about 300 parts per hundred based on 100 parts of the neutralized sulfonated elastomeric polymer, more preferably about 30 to about 250; and most preferably about 50 to about 200.
The fillers employed in the present invention are selected from carbon blacks, talcs, ground calcium carbonate, water precipitated calcium carbonate, or delaminated, calcined or hydrated clays and mixtures thereof. Examples of carbon black are oxides, acetylinics, lamp, furnace or channel blacks. Typically these fillers have a particle size of about 0.03 to about 15 microns, more preferably about 0.5 to about 10, and most preferably about 2 to about 10. The oil absorption of the filler as measured by grams of oil absorbed by 100 grams of filler is about 10 to about 70, more preferably about 10 to about 50 and most preferably about 10 to about 30. Typical fillers employed in this invention are illustrated in Table 1.
The oils employed in the present invention are non-polar backbone process oils having less than about 3.5 wt. % polar type compounds as measured by molecular clay gel analysis. These oils are selected from paraffinics ASTM Type 104B as defined in ASTM-D-2226-70, aromatic ASTM Type 102 or naphthenics ASTM 104A, wherein the oil has a flash point by the Cleveland open cup of at least 350° F.; a pour point of less than 40° F., a viscosity of about 70 to about 3000 s.s.u.'s and a number average molecular weight of about 300 to about 1000, more preferably about 400 to about 75°. The preferred oils are napthenics. Table II illustrates typical oils encompassed by the scope of this invention.
TABLE I__________________________________________________________________________ Oil Absorption Specific Avg. ParticleFiller Code # grams of oil/100 grams of filler Gravity Size Micron pH__________________________________________________________________________calcium carbonate ground 15 2.71 9.3calcium carbonateprecipitated 35 2.65 .03-.04 9.3delaminated clay 30 2.61 4.5 6.5-7.5hydrated clay 2.6 2 4.0calcined clay 50-55 2.63 1 5.0-6.0magnesium silicate (talc) 60-70 2.75 2 9.0-9.5__________________________________________________________________________
TABLE II__________________________________________________________________________ Viscosity % % %Type Oil Oil Code # ssu 100° F. Mn Polars Aromatic Saturates__________________________________________________________________________Paraffinic Sunpar 115 155 400 0.3 12.7 87.0Paraffinic Sunpar 180 750 570 0.7 17.0 82.3Paraffinic Sunpar 2280 2907 720 1.5 22.0 76.5Aromatic Flexon 340 120 -- 1.3 70.3 28.4Naphthenic Flexon 765 505 -- 0.9 20.8 78.3Naphthenic Flexon 580 1855 -- 3.3 47.0 49.7__________________________________________________________________________
Alternatively, the oils can be incorporated in the elastomeric heterogeneous blend by the addition of the oil under agitation to the solution of the mixture of the neutralized sulfonated elastomeric polymer and the polystyrene or sulfonated polystyrene prior to the steam stripping step.
Compression molded pads were made of the heterogeneous blends at 350° F. for 5 min. wherein the sample pads were 2"×2"×0.040". Micro specimens were cut out from the pads for tensile, hardness, compression set, and stress relaxation measurements.
Tensile measurements were made by an Instron Tester at the crosshead speed of 2 in./min. using micro-dumbbell specimens. Melt rheological properties were measured by an Instron Capillary Rheometer with a 0.050" D×1", L, 90° entrance angle capillary.
The application for the heterogeneous blends of this invention are diverse. The blends have excellent injection molding and extrusion properties. For example, injection molded shoe soles may be prepared from the instant blends because of their excellent abrasion resistance and flex fatigue properties which are highly desired in such application. Injection molded parts for automotive applications may be prepared from the blends of this invention, e.g., automobile sight shields, flexible bumpers, grill parts, etc. It is readily apparent to those skilled in the art that the properties, such as rigidity, can be varied widely depending on the level of the polystyrene or sulfonated polystyrene incorporated in the sulfonated elastomeric polymer, thus fabrication of rigid or semiflexible articles from the instant blends is contemplated. Articles from the blends of the instant invention may also be prepared by extrusion techniques. For example, garden hose, having outstanding strength in combination with light weight is one application. The electrical properties of these materials also allow the use of the instant blends as insulation for wire. Insulation prepared from rubber or polyethylene often requires a curing or vulcanization step to obtain optimum properties. The blends of this invention have excellent physical properties, and excellent electrical properties without the need for any curing step. The fact that chemical curing is not required permits a relatively high speed extrusion operation which are not feasible with those systems requiring a curing step.
Other fabrication processes for these materials include vacuum forming, flow molding, slit extrusion, profile extrusion and similar operations. The wide versatility, from a fabrication viewpoint, permits the use of these blends in film, containers such as bottles, oriented sheet, fibers, especially oriented monofilament, packaging, appliance housing, floor mats, carpet backing, toys, sporting goods such as swim fins, face masks, and similar applications.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the invention may be understood with reference to the following detailed description of an illustrative embodiment of the invention taken together with the accompanying drawings in which:
FIG. 1 illustrates a graph of gum tensile properties at room temperature and the effect of sulfonation on an EPDM terpolymer;
FIG. 2 illustrates a graph of gum tensile properties at 200° C.;
FIG. 3 illustrates a graph of stress relaxation as a function of temperature;
FIGS. 4 and 5 illustrates a graph of the rheological properties of a sulfo-EPDM at 200° C.;
FIG. 6 illustrates a graph of the tensile properties of a sulfo-EPT (EPDM) at room temperature;
FIG. 7 illustrates a graph of the tensile properties of sulfo-EPT (EPDM) compound at room temperature;
FIG. 8 illustrates a graph of the tensile properties of a sulfo-EPT (EPDM) gum at room temperature;
FIG. 9 illustrates a graph of the tensile properties of a sulfo-EPT (EPDM) compound at room temperature;
FIG. 10 illustrates a graph of the tensile properties of the sulfo-EPT (EPDM) gum at room temperature;
FIG. 11 illustrates a graph of the tensile properties of the sulfo-EPT (EPDM) compound at room temperature;
FIG. 12 illustrates a graph of the tensile properties of the sulfo-EPT (EPDM) gum at room temperature as effected by the sulfonation level of a polystyrene; and
FIG. 13 illustrates a graph of the tensile properties of the sulfo EPT (EPDM) gum at room temperature as effected by the sulfonation level of a polystyrene.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The advantages of the unique and novel elastomeric heterogeneous blend compositions and the unique and novel process for the formation of these compositions can be more readily appreciated by reference to the following examples, tables, and figures.
EXAMPLE I--PREPARATION OF AN ACID FORM OF A SULFONATED EPDM TERPOLYMER
To a solution of 90 grams of EPDM terpolymer (Vistalon 3708--Exxon Chemical Co.) in 3 liters of carbon tetrachloride at 50° C. was added a solution of a sulfonating agent which was formed at 10° from 141 ml. of methylene chloride, 2.4 ml. of sulfur trioxide, and 5 ml. of dioxane. Sulfonation was terminated after 30 min. by quenching with methanol. The acid form of the sulfonated EPDM terpolymer had 0.8 mole percent of SO 3 H groups/100 grams of terpolymer.
EXAMPLE II--PREPARATION OF AN ACID FORM OF A SULFONATED POLYSTYRENE RESIN
To a solution 20.8 grams of a polystyrene resin having an Mw of 287×10 3 (Styron 666) in 100 ml. of carbon tetrachloride at 50° C. was added a solution of a sulfonating agent which was formed at 10° C. from 4.762 ml. of ethylene dichloride, 0.905 ml. of anhydrous acetic anhydride and 0.333 ml. of 96.5% concentrated sulfuric acid and sulfonation was terminated after 60 min. by quenching with methanol. The acid form of the sulfonated polystyrene resin had 3.0 mole percent of SO 3 H groups/grams of polystyrene resin. Sulfonated polystyrene resins having an Mw of 93×10 3 were also prepared, wherein the mole percent of SO 3 H was 3.0 or 6.0.
EXAMPLE III--PREPARATION OF ELASTOMERIC BLEND COMPOSITIONS
To the quenched solution of the sulfonated EPDM terpolymer, prepared according to Example I, was added a solution of polystyrene resin dissolved in carbon tetrachloride having an Mw of 93×10 3 or 287×10 3 . The resultant blended solution was neutralized at room temperature for 30 min. with di-ortho-tolyl guanidine (DOTG). The elastomeric blend compositions were recovered from solution by steam stripping.
Alternatively, to the quenched solution of the sulfonated EPDM terpolymer prepared according to Example I was added the solutions of Example II of the acid form of the sulfonated polystyrene resin having an Mw of 287×10 3 or 93×10 3 . The resultant blended solution was neutralized at room temperature for 30 minutes with di-ortho-tolyl guanidine. The elastomeric blend compositions were isolated from solution by steam stripping.
The elastomeric blend compositions were compounded on a hot micro-rubber mill. Sample pads of 2"×2"×0.040" were molded at 35° F. for 5 min. Micro-specimens were cut out from the pads for tensile hardness, compression set and stress relaxation measurements.
Table III illustrates the formulas for these blend compositions and their physical properties as compared to an unsulfonated EPDM 3708 terpolymer, a sulfonated EPDM 3708 terpolymer, and Kraton 101.
TABLE III__________________________________________________________________________ELASTOMERIC BLEND COMPOSITIONSwt. % ofsulfonated wt. % ofEPDM ter- sulfonatedpolymer polystyrene Compression Set Other0.8 mole % Sample wt. % of 3.0 mole % --Mw Shore A ASTM-R Elastomericof SO.sub.3 . DOTG # polystyrene of SO.sub.3 . DOTG polystyrene Hardness RT 40° C. Resin__________________________________________________________________________100 1-1 -- -- -- 73.0 43.5 76.990 1-2 10 -- 287 × 10.sup.3 74.0 48.8 10090 1-3 -- 10 287 × 10.sup.3 73.0 39.9 10080 1-4 20 -- 287 × 10.sup.3 80.0 52.2 10080 1-5 -- 20 287 × 10.sup.3 76.0 46.2 10090 1-6 10 -- 93 × 10.sup.3 76.0 43.0 77.190 1-7 -- 10 93 × 10.sup.3 80.0 39.3 77.7-- 1-8 -- -- -- 65.0 39.0 84.9-- 1-9 -- -- -- 63.0 41.0 61.0 EPDM 3708 Kraton 101__________________________________________________________________________
Sulfonation of EPDM 3708 improves the tensile properties as shown in FIG. 1 as compared to unsulfonated EPDM 3708; however, sulfonation and neutralization severely deteriorates the rheological properties of EPDM as shown in FIG. 2. The neutralized sulfonated EPDM 3708 has very poor flow stability manifested by melt fracture at a low shear rate of 15 sec -1 and about 3 times as high viscosity at 200° C. as that of unsulfonated EPDM 3708. The hardness as seen in Table I of the EPDM terpolymer increases upon sulfonation and neutralization. The addition of 10 percent of polystyrene having an Mw of 287×10 3 or sulfonated polystyrene having an Mw of 287×10 3 does not change the hardness. However, the addition of either 10% of sulfonated or unsulfonated polystyrene having an Mw of 93×10 3 increases the hardness. Increasing the wt. % of the sulfonated or unsulfonated polystyrene increases slightly the hardness. The addition of the sulfonated or unsulfonated polystyrene has little effect on the compression set, wherein the compositions with sulfonated polystyrene has somewhat lower compression set than samples from unsulfonated polystyrene.
FIG. 3 shows the effect of the sulfonated polystyrene on the equilibrium stress relaxation modulus of sulfonated EPDM 3708 as a function of temperature. Ten percent of sulfonated polystyrene has no effect on the equilibrium stress relaxation modulus of the sulfonated EPDM 3708.
FIGS. 4 and 5 show the improvements in the rheological properties of the DOTG neutralized sulfonated EPDM 3708 by the addition of the sulfonated or unsulfonated polystyrene. In both cases, the viscosity is reduced and the flow stability is improved. FIGS. 4 and 5 also show that the rheological properties are uneffected by changes in the Mw of the sulfonated or unsulfonated polystyrene.
FIGS. 6-11 show the effect on tensile properties of the addition of the sulfonated or unsulfonated polystyrene to the sulfonated EPDM 3708 matrix. The sulfonated polystyrene appears to improve the tensile properties better than does the unsulfonated polystyrene.
FIGS. 12 and 13 show the effect of the sulfonation level of the polystyrene on the tensile properties of the blended elastomeric composition. Six mole percent sulfonated polystyrene gives somewhat inferior tensile properties as compared to 3 mole percent sulfonated polystyrene at the same loading.
EXAMPLE IV
The compositions of Example III including the sulfonated EPDM 3708 were blended according to the following formula and compounded on a micro-two roll rubber mill to give extended elastomeric blend compositions.
______________________________________ wt. percent______________________________________Blend Compositions of Example III 28.57Flexon Oil 580 (Exxon Chemical Co.) 28.57HAF Carbon Black (Cabot Corp.) 42.86______________________________________
Sample pads of 2"×2"×0.040" were molded at 350° F. for five min. and micro-specimens were cut out for physical testing.
Tables III and IV clearly show that the incorporation of the filler and oil generally increases the hardness and compression set for the elastomeric blend compositions of the neutralized sulfonated EPDM 3708 and either the neutralized sulfonated or unsulfonated polystyrene.
FIGS. 7, 9 and 10 show the tensile properties for the extended elastomeric blend compositions that the tensile properties are improved by the addition of either neutralized sulfonated or unsulfonated polystyrene, wherein the neutralized sulfonated polystyrene seems to be somewhat more effective.
The elastomeric blend compositions prepared by the improved unique and novel process of this invention can be fabricated by conventional rubber fabricating techniques into a number of useful articles. For example, film, washer hose and radiator hose have been made by an extrusion process.
Since, many modifications of this invention may have been made without departing from the spirit or scope of the invention thereof, it is not intended to limit the scope or spirit to the specific examples thereof.
TABLE IV__________________________________________________________________________ELASTOMERIC BLEND COMPOSITIONSEXTENDED WITH FILLER AND OILwt. % ofsulfonated wt. % ofEPDM ter- sulfonatedpolymer polystyrene Compression Set0.8 mole % Sample wt. % of 3.0 mole % --Mw Shore A ASTM-Rof SO.sub.3.DOTG # polystyrene of SO.sub.3.DOTG polystyrene Hardness RT 40° C.__________________________________________________________________________100 2-1 -- -- -- 81 100 10090 2-2 10 -- 287 × 10.sup.3 85 100 10090 2-3 -- 10 287 × 10.sup.3 83 80.7 10080 2-4 20 -- 287 × 10.sup.3 87 100 10080 2-5 -- 20 287 × 10.sup.3 85 100 10090 2-6 10 -- 93 × 10.sup.3 72 71.5 10090 2-7 -- 10 93 × 10.sup.3 81 87.1 96.3__________________________________________________________________________ | This invention relates to heterogeneous elastomeric blends having improved rheological properties of a major portion of a neutralized sulfonated elastomeric polymer with a minor portion of a polystyrene thermoplastic resin or a neutralized sulfonated polystyrene resin and mixtures thereof. Both the sulfonated elastomeric polymer and the sulfonated thermoplastic resin have about 0.2 to about 10.0 mole percent of SO 3 H groups, at least 90% of which are neutralized with an organic amine. | 2 |
FIELD
The present invention relates to the control of policy management in devices, especially user equipment and communications devices, and most particularly to the control of policy management in telecommunications equipment.
BACKGROUND
Communication networks typically operate in accordance with a given standard or specification which sets out what the various elements of the network are permitted to do and how that should be achieved. For example, the standard may define whether the user or more precisely, user equipment is provided with a circuit switched service or a packet switched service. The standard may also define the communication protocols which shall be used for the connection. The given standard also defines one or more of the required connection parameters. The connection parameters may relate to various features of the connection. The parameters may define features such as the maximum number of traffic channels, quality of service and so on or features that relate to multislot transmission.
In other words, the standard defines the “rules” and parameters on which the communication within the communication system can be based. Examples of the different standards and/or specifications include, without limiting to these, specifications such as GSM (Global System for Mobile communications) or various GSM based systems (such as GPRS: General Packet Radio Service), AMPS (American Mobile Phone System), DAMPS (Digital AMPS), WCDMA (Wideband Code Division Multiple Access) or CDMA in UMTS (Code Division Multiple Access in Universal Mobile Telecommunications System) and so on.
The user equipment i.e. a terminal that is to be used for communication over a particular communication network has to be implemented in accordance with the predefined “rules” of the network. A terminal may also be arranged to be compatible with more than one standard or specification, i.e. the terminal may communicate in accordance with several different types of communication services. These user equipment are often called multi-mode terminals, the basic example thereof being a dual-mode mobile station.
It is important that in order to make such communication systems behave as required, the users and operators of the systems use a set of policies that specify how the system should respond to various situations. Policy may be considered to be a combination of rules and services where rules define the criteria for resource access and usage. Policy is required for certain services in order to define which services are supported and how they are supported.
Important functions in policy control are the configuration and management of the policies (e.g. typically via a human interface of the policy control mechanism), and the resolution and enforcement of the policies (e.g. typically via an automated part of the mechanism). The policy resolution and enforcement applies the configured policies by first receiving as an input a trigger event that initiates the resolution of a policy, and then sending as output instructions that enforce the outcome of the resolved policy action.
One example of policy control area is multi-access, i.e. where a multi-mode device has multiple interfaces, logical accesses and connected network domains over which it has connections and traffic flows. The device can have access over these multiple networks sequentially or simultaneously, and policies are needed to describe which connection is acceptable over which network, as well as whether it can or should be moved to a new network.
An example of policy resolution is when a trigger event such as a detection of an interface losing connectivity to a network causes the policy action of attempting detection of a new network with a different interface, joining the new network and then moving all traffic to it from the previous network. The policies involved in this task easily become very complicated, and multiple trigger events can be received during very short periods of time. The policy actions may also become available for sending as outputs at different times, because resolution of some consists of more steps and takes more time than for the others.
Additionally, policies may be created for very different purposes but nevertheless for the same device. For example, a mobile terminal may contain employer's policies that enforce a wide range of parameters in a strictly controlled fashion. But it can also contain policies defined by the employee for use during his leisure time, with lenient interpretation of only a few key parameters. And it may contain yet further policies defined by the provider of a software application running in the terminal, and being able to very exactly define the preferred values for a certain type of traffic. It would be desirable to use all these policies at the same time, but still keep the overall policy framework (including provisioning and configuration) easy to use and efficient to execute.
Known policy management methods may be platform specific due to the use of compilers producing executable binaries, or may not be available to end users, or may involve drastic resource consumption or delays during compilation, or may require rebooting of the device. In addition, policy syntax and formats that would allow detailed processing of versatile inputs are complex and heavy, and the same applies to interpreters using such policies. Policy control methods using lookups are limited to a few parameters or parameter values, or otherwise take a large amount of memory.
Accordingly, there is a need for an improved method of policy management in a user equipment, which provides high performance and versatile policy resolution but in which policies can be easily entered, configured or modified. Embodiments of the present invention aim to address one or more of the above-mentioned problems.
SUMMARY
Accordingly, in one embodiment the present invention provides a method (for example for controlling policy management in a user equipment) comprising storing in a device (e.g. a communication device or user equipment) a static policy framework and one or more (e.g. a plurality of) dynamic policy algorithms, and controlling policy management in the device by operating the static policy framework and executing one or more of the dynamic policy algorithms.
In a further embodiment, the present invention provides an apparatus (e.g. a device such as a user equipment) comprising a memory for storing a static policy framework and one or more dynamic policy algorithms, and a processor, wherein the processor is configured to control policy management in the apparatus by operating the static policy framework and executing one or more of the dynamic policy algorithms.
In a further embodiment, the present invention provides an apparatus (e.g. a device such as a user equipment) comprising a storage means for storing a static policy framework and a plurality of dynamic policy algorithms, and a policy management means for controlling policy management by operating the static policy framework and executing the dynamic policy algorithms.
In a further embodiment, the present invention provides a computer program product (for example a set of instructions or program code means stored on a computer-readable medium) which when executed on a processor in a device (for example a user equipment) causes the processor to operate a static policy framework and execute a plurality of dynamic policy algorithms for controlling policy management in the device.
In one embodiment the device or apparatus (e.g. user equipment) comprises a mobile terminal, more preferably a multi-access or multi-mode mobile terminal, e.g. a terminal which is capable of connecting to two or more different access networks. Thus one or more of the dynamic policy algorithms may be associated with a policy controlling connectivity of the user equipment to different networks, for instance in selecting an appropriate access mode for the terminal.
Each dynamic policy algorithm can be modified by two or more policy owners, for instance using an input means provided in the user equipment. The input means may comprise any suitable data input means, for instance a keyboard, selection device or text editor. The policy algorithms may be considered to be “dynamic” in the sense that they are capable of being changed, modified, entered or deleted by the policy owners.
Each dynamic policy algorithm can have a static set of inputs and a static set of outputs, for example a defined or controlled range of inputs and outputs which are considered to be compatible with the algorithm. The dynamic policy algorithms may be stored in memory as a structure of commands which operate on registers. The structure of the commands may be varied according to different embodiments of the present invention.
In one such embodiment, the structure comprises a table of values and an operation is performed on each input register in turn in a single pass. In a second embodiment, the structure comprises a list of commands, each command being preceded by a pointer to a register on which an operation is to be performed. In a third embodiment, which may be considered to be a hybrid of the first and second embodiments mentioned above, the structure comprises both a table structure and a list structure, and a toggling command switches a mode of operation of the algorithm between a table mode and a list mode.
Typically the input values for a dynamic policy algorithm to be executed are provided by the static policy framework, and are read to registers before execution of the dynamic policy algorithm. In some embodiments, the method may further comprise checking that the input values provided by the static policy framework are within a parameter range defined in a configured policy.
In a similar way, output values are preferably written from the registers to the static policy framework after execution of the dynamic policy algorithm. The method may comprise a further preferred step of checking that the output values to be written to the static policy framework are within a range defined in a configured policy.
In some embodiments each command comprises an argument field.
The static policy framework may typically comprise a plurality of specific policy algorithms for controlling policy management, e.g. static, non-modifiable algorithms designed for controlling defined policies.
In one embodiment, the processor of the user equipment operates an algorithm management function, which may comprise a step of checking that the dynamic policy algorithms stored or entered into the user equipment are compatible with the static policy framework. The algorithm management function may further operate to verify that the dynamic policy algorithms entered or stored in the user equipment were entered by an authorised policy creator. In another embodiment, the algorithm management function may operate to initiate storage of entered dynamic policy algorithms locally (e.g. within memory in the user equipment) or it may initiate transmission of the entered or stored dynamic policy algorithms to a remote device or location, for instance to a node within a telecommunications network to which the user equipment is connected.
In another embodiment, the processor is configured to operate an algorithm interpreter function for reading and executing the dynamic policy algorithms. Thus in some embodiments the dynamic policy algorithms may be executed using an interpreter. Embodiments of the invention may utilise an interpreter supporting relevant parts of a language such as Lua, APL, awk, or Scheme (with e.g. GNU Guile interpreter). Alternatively, the interpreter may interpret an assembly language (e.g. GNU Assembler or Netwide Assembler).
Embodiments of the present invention may split policies into a combination of dynamic and specific algorithms within a static policy framework. Each dynamic policy algorithm may have a static set of inputs and outputs that fit to its placement in the static policy framework, but the logic within the dynamic policy algorithm may be modifiable by various policy owners. Therefore, the same overall policy engine can be customized for a particular policy owner, or it can simultaneously support the divergent needs of multiple policy owners. The dynamic policy algorithms may be stored in memory as a structure of simple commands that operate on registers. The commands contain e.g. arithmetic and logical operations, and can be interpreted using an efficient dynamic algorithm interpreter function. The inputs of the algorithm may be stored into the registers before the algorithm execution, and the outputs can be read from the registers afterwards. The range of input and output values may be controlled. Embodiments of the invention may allow tailoring and very fast changing of policy contents while supporting high performance execution. There is no need for platform specific compilers, complex and heavy policy syntax and interpreters, or limitation of policy control to a few parameters.
Embodiments of the present invention may be an enhancement of current policy engines, especially for use in multi-access terminals, that complements a static and purpose specific, high performance policy framework with additional and more detailed dynamic algorithms for specific parts of functionality where it is likely that different policy owners may need to have different type of policy execution, or where different terminal models or variants may require easily upgradable policies. The static policy framework uses the dynamic algorithms as necessary, and may need to execute them very frequently (e.g. an algorithm may be evaluated inside an O(N 3 ) loop).
The dynamic algorithms used in the present invention may resemble low level programming languages such as assembler and in certain embodiments can conveniently be written by proficient device or software vendors or system administrators. In preferred embodiments the end users of the device would at most need to choose the appropriate policy owner (unless chosen automatically by the device).
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example only with respect to the following specific embodiment, in which:
FIG. 1 shows a user equipment according to one embodiment of the present invention;
FIG. 2 shows aspects of dynamic policy algorithm creation and storage in a terminal according to one embodiment;
FIG. 3 shows aspects of dynamic policy algorithm execution according to one embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
FIG. 1 shows a user equipment in the form of a multi-access mobile terminal 1 according to one embodiment of the present invention. Only selected features of the terminal 1 which are relevant for the present discussion are shown in FIG. 1 . The terminal 1 comprises a processor 2 , a memory 3 , registers 4 and an input device 5 .
The memory 3 stores a static policy framework 8 and a plurality of dynamic policy algorithms 9 . The dynamic policy algorithms 9 stored in the memory may be modified using the input device 5 , and further dynamic algorithms may also be entered into the terminal in a similar manner. The static policy framework 8 comprises a plurality of specific algorithms for controlling various aspects of policy management in the terminal 1 . The specific algorithms of the static policy framework 8 are typically non-modifiable.
The processor 2 is configured to operate an algorithm management function 7 and an algorithm interpreter function 6 . The operation of these functions is described below.
Policy management in the terminal 1 may be controlled by the processor 2 using the static policy framework 8 and the dynamic policy algorithms 9 . The algorithm management function 7 knows the definitions for dynamic algorithms used by various policy engines in the terminal, including expected inputs and outputs. Various aspects of algorithm management may be performed by this function.
As shown in FIG. 2 , in a first aspect the algorithm management function 7 controls the entry and configuration of dynamic policy algorithms in the terminal. Thus a policy creator may enter a new dynamic algorithm or modify an existing algorithm (see step 21 in FIG. 2 ) using the input device 5 . This can be as simple as using a text editor, but it can also be a more complete translator that converts higher level syntax into the strictly defined syntax and commands defined in the invention. After this, the algorithm manager stores the dynamic algorithm as a table of values.
In another aspect, the algorithm management function 7 performs a validity check on entered or modified algorithms (see 22 in FIG. 2 ). This confirms that the policy contents uses valid commands and parameter ranges, and the inputs and outputs are as required by the policy framework that uses this dynamic algorithm. It also confirms that there is no division by zero or similar logical errors.
In another aspect, the algorithm management function 7 performs a policy configuration access control function (see 23 in FIG. 2 ). Prior to application of the policies, the manager checks that the policy creator is authorized to update this particular policy, possibly including a currently existing policy by another policy owner. The algorithm management function 7 may decide whether the policy creator is authorised to update the policy based, for example, on the use of a priority list or may derive the authorized policy owner information from terminal rights administrator settings.
In another aspect, the algorithm management function 7 initiates provisioning and storage of the dynamic algorithm to an appropriate policy engine in the terminal (see 24 in FIG. 2 ). This step can be set to take place at a certain time or upon a certain condition, such as change of device user or change of user profile. The policy can be stored directly locally, or provisioned to a remote device. The ready made policies are stored into memory starting from the given address (usable with a pointer).
As an alternative to updating by replacing an existing dynamic policy algorithm, the algorithm management function 7 may select a dynamic policy algorithm that performs the same task (but differently, e.g. due to being created by different administrators) as the currently active dynamic algorithm (see 31 in FIG. 3 ), while still storing the other equivalent algorithms as inactive versions that can be activated as needed. In other embodiments multiple dynamic policy algorithms may be active simultaneously. The algorithm management function may select one of the active dynamic policy algorithms for execution (see 32 in FIG. 3 ) according to the user (or his/her administrator, or an application whose session the decision affects).
Before execution of the dynamic algorithms 9 , inputs given by static policy framework 8 are read to the registers 4 (see 33 in FIG. 3 ), typically so that the dynamic algorithm interpretation (execution) function 6 is given a pointer to the registers 4 where the values are stored. The processor 2 performs a validity checking operation (see 34 in FIG. 3 ) such that the range of input values from the policy framework 8 is controlled so that they remain within the limits set in the configured policy (which was in turn validity checked based on the knowledge of the policy engine requirements for that particular algorithm). For this purpose, each input has associated minimum and maximum thresholds. Any value outside of this range is replaced with the threshold value.
Execution of the dynamic policy algorithms 9 is performed by the algorithm interpreter function 6 (see 35 in FIG. 3 ), operating on registers 4 . The dynamic algorithm is stored in memory 3 as a structure of commands. The execution/interpreter function 6 reads and executes each command sequentially.
The structure can be a table where the execution function performs an operation on each input register in turn in one pass, and then makes a second pass starting with the first register again, and so on. This is useful for cases where some operations are applied in parallel (i.e. at the same time) to many sets of inputs, at least most of the time (e.g. the same ten operations to registers 1 - 3 , 4 - 6 , 7 - 9 , and 10 - 12 ).
The structure can also be a list of individual commands that always refer to the register that is operated. In this case, each command is preceded with a pointer to (index of) such a register.
The structure can also be a hybrid, where a special command (or found by testing a masked command bit pattern with e.g. if (cmd & 0x30)==0x30) toggles the mode between a table based and a list based structure and execution.
The commands describe very simple and basic operations, including arithmetic and logical operations. For the purposes of fast execution, the commands are arranged into an order that can be narrowed down with binary operations. Each command also includes an argument field.
The highest bit describes the use of the argument field. For example:
0 means that the argument field is not used. The following bit 0 means that there is an argument of 0 or 1 to the operation, and 1 means that the currently processed register is used as argument;
1 means that the argument field is used. The following bit 0 means that the argument field is an argument to the operation, and 1 means that the argument field is a pointer to the register used as argument to the operation;
The following two bits mostly describe whether the second operand is the currently processed register (bits 10 ), or the additional (singular) memory register (bits 11 ). Other interpretations are also possible, depending on the values of the highest two bits.
The fifth bit describes whether the result of the operation is stored in the currently processed register ( 0 ) or the additional (singular) memory register ( 1 ).
The last three bits mostly describe the exact operation that the command describes.
Following execution of a dynamic algorithm, the outputs are written to the static policy framework 8 (see 37 in FIG. 3 ), typically by using the same registers 4 and pointer as with the inputs. There is similar validity checking (including minimum and maximum thresholds) before the outputs are written (see 36 in FIG. 3 ) as was after the inputs were read.
By way of specific example, the execution of an individual command can be done as shown in the following source code (in pseudocode) for an interpreter that takes as input an 8-bit operator (op) and an argument (arg). The interpreter also contains a temporary value register (mem) and a register set corresponding to the interpreted dynamic policy table (which initially stores the input values, and at the end the output values). This pseudocode is executed by the processor once per (op, arg) pair, i.e. N times for each dynamic policy table column and M times for each two dynamic policy table rows (assuming odd row is op, even row is arg). The variable ctr indicates the column on whose (op,arg) pair the interpreter is currently executing.
//DynAlg expression generation and execution loop
opb67=op&0xc0; opb45=op&0x30;
if
opb67==0xc0
expr2=reg[arg[ctr]];
else if
opb67==0x80
expr2=arg[ctr];
else if
opb67==0x40
expr2=reg[ctr];
else
expr2=1;
if
opb67!=0x00 || op&ox1f==0x00 {
if
opb45==0x30
expr1=mem;
else if
opb45==0x20
expr1=reg[ctr];
else if
opb45==0x10 {
if
op&0x04==0x04 expr1=mem;
else
expr1=reg[ctr];
else {
if
op&0x04==0x04 expr1=mem;
else
expr1=reg[ctr];
}
if
opb67!=0x00 && op&0x20!=0x20 {
switch
(op&0x07) {
case 0:
expr0=expr1*expr2; break;
case 2:
expr0=expr1/expr2; break;
case 3:
expr0=expr1%expr2; break;
case 4:
expr0=expr1&expr2; break;
case 5:
expr0=expr1|expr2; break;
case 6:
expr0=expr1{circumflex over ( )}expr2; break;
}
if
op&0x08==0x08 mem=expr0;
else
reg[ctr]=expr0;
}
else {
if
opb45==0x10 {
switch
(op&0x03) {
case 0:
expr0=expr1+expr2; break;
case 1:
expr0=expr1−expr2; break;
case 2:
expr0=expr1<<expr2; break;
case 3:
expr0=expr1>>expr2; break;
}
if
op&0x08==0x08
mem=expr0;
else
reg[ctr]=expr0;
}
else if
opb45==0x00 {
if
op&0x04==0x04 {
if
opb67==0x00 expr2=0;
switch
(op&0x03) {
case 0:
if reg[ctr]==expr2
{ expr0=expr1; flag==1;
break; }
case 1:
if reg[ctr]<expr2
{ expr0=expr1; flag==1;
break; }
case 2:
if mem==expr2
{ expr0=expr1; flag==1;
break; }
case 3:
if mem<expr2
{ expr0=expr1;
flag==1; break; }
}
if flag==1 {
if
op&0x08==0x08
mem=expr0;
else
reg[ctr]=expr0;
}
else if
opb67!=0x00 {
if
op&0x02 {
if
op&0x01
mem=expr2;
else
mem=−expr2;
}
else {
if
op&0x01
reg[ctr]=expr2;
else
reg[ctr]=−expr2;
}
if
op&0x0a==0x02
reg[ctr]=mem;
else if
op&0x0a==0x08
mem=reg[ctr];
}
else {
switch
(op&0x0b) {
case 1:
reg[ctr]=mem; break;
case 2:
reg[ctr]=(reg[ctr]<<1)>>1; break;
case 3:
reg[ctr]=(mem<<1)>>1; break;
case 9:
mem=mem; break;
case 10:
mem=(reg[ctr]<<1)>>1; break;
case 11:
mem=(mem<<1)>>1; break;
}
}
else if
op&0xf0==0x20 {
switch
(op&0x07) {
case 0:
expr0=0; break;
case 1:
expr0=1; break;
case 4:
expr0=ctr_tot; break;
case 5:
expr0=ctr_mem; break;
}
if
op&0x08==0x08
mem=expr0;
else
reg[ctr]=expr0;
}
else {
}
}
By way of example, the structure of some commands which can be used in embodiments of the present invention are shown in the table below:
Operation
Operd2
type
Operd1
type
Result
Opclass
Optype
result
1st operand
2nd operand
0
0
0
0
0
0
0
0
0
reg
=
reg
1
0
0
0
0
0
0
0
1
reg
=
mem
2
0
0
0
0
0
0
1
0
reg
=
reg<<1; reg
>>
1
3
0
0
0
0
0
0
1
1
reg
=
mem<<1; mem
>>
1
4
0
0
0
0
0
1
0
0
reg
=
mem if reg
==
0
5
0
0
0
0
0
1
0
1
reg
=
mem if reg
>
0
6
0
0
0
0
0
1
1
0
reg
=
mem if mem
==
0
7
0
0
0
0
0
1
1
1
reg
=
mem if mem
>
0
8
0
0
0
0
1
0
0
0
mem
=
reg
9
0
0
0
0
1
0
0
1
mem
=
10
0
0
0
0
1
0
1
0
mem
=
reg<<1; reg
>>
1
11
0
0
0
0
1
0
1
1
mem
=
mem<<1; mem
>>
1
12
0
0
0
0
1
1
0
0
mem
=
reg if reg
==
0
13
0
0
0
0
1
1
0
1
mem
=
reg if reg
>
0
14
0
0
0
0
1
1
1
0
mem
=
reg if mem
==
0
15
0
0
0
0
1
1
1
1
mem
=
reg if mem
>
0
16
0
0
0
1
0
0
0
0
reg
=
reg
+
1
17
0
0
0
1
0
0
0
1
reg
=
reg
−
1
18
0
0
0
1
0
0
1
0
reg
=
reg
<<
1
19
0
0
0
1
0
0
1
1
reg
=
reg
>>
1
20
0
0
0
1
0
1
0
0
reg
=
mem
+
1
21
0
0
0
1
0
1
0
1
reg
=
mem
−
1
22
0
0
0
1
0
1
1
0
reg
=
mem
<<
1
23
0
0
0
1
0
1
1
1
reg
=
mem
>>
1
The invention has been described above for 8 bit architectures in order to be usable even for low performance devices, but it can be optimized for other architectures as necessary.
Although the present invention has been described above with reference to specific embodiments, it will be appreciated by a skilled person that many modifications and variations are possible within the scope of the appended claims.
Although in the appended claims the dependent claims may refer only to an independent claim on which they depend, embodiments of the present invention may encompass any combination of features disclosed in the claims. In particular, embodiments of the present invention may comprise features from any two or more dependant claims in combination with an independent claim on which they depend. | According to one embodiment a method is disclosed involving storing in a device a static policy framework and one or more dynamic policy algorithms, and controlling policy management in the device by operating the static policy framework and executing the dynamic policy algorithms. The invention also provides in other embodiments an apparatus configured to perform such a method and a computer program product for performing the method. | 7 |
BACKGROUND
[0001] 1. Technical Field
[0002] An embodiment of this invention relates to the field of gesture detection and localization, and more specifically, to a system, method, and apparatus for detecting and classifying a gesture represented in a stream of positional data.
[0003] 2. Description of the Related Arts
[0004] There are current gesture detection systems in the art for acquiring a stream of positional data and determining what gestures, if any, are represented in the stream of positional data. The stream of positional data often includes data representing multiple gestures. Such systems typically provide a start and an end point of a gesture represented in the positional data, and then compare the positional data located between the start and the end points with data representing a set of known gestures. The known gesture which most closely resembles the positional data located between the start and end points is then determined to be the gesture represented, and is returned as the represented gesture.
[0005] Such systems are deficient, however, because the start and the end points must be known prior to determining the gesture represented. In other words, the system cannot determine which gesture is represented unless prior knowledge about the start and the end points is provided. Also, such systems typically return the gesture most closely matching the positional data between the start and the end points, even if the correlation between the most closely matching gesture and the positional data between the start and the end points is very small.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1A illustrates a spline according to an embodiment of the invention;
[0007] [0007]FIG. 1B illustrates a spline and associated control points (i.e., first control point, second control point, third control point, fourth control point, fifth control point, sixth control point, and seventh control point) according to an embodiment of the invention;
[0008] [0008]FIG. 2 illustrates a gesture recognition device according to an embodiment of the invention;
[0009] [0009]FIG. 3A illustrates a raw data acquisition device utilizing a mouse according to an embodiment of the invention;
[0010] [0010]FIG. 3B illustrates a raw data acquisition device utilizing an I/O device according to an embodiment of the invention; FIG. 3C illustrates a raw data acquisition device utilizing a touchpad according to an embodiment of the invention;
[0011] [0011]FIG. 3D illustrates a raw data acquisition device utilizing a videocamera according to an embodiment of the invention;
[0012] [0012]FIG. 4 illustrates a spline-generating method according to an embodiment of the invention;
[0013] [0013]FIG. 5 illustrates an expanded view of the normalization device according to an embodiment of the invention;
[0014] [0014]FIG. 6 illustrates a normalization process according to an embodiment of the invention;
[0015] [0015]FIG. 7 illustrates a goodness determination method according to an embodiment of the invention;
[0016] [0016]FIG. 8A illustrates a first part of a process to detect a gesture according to an embodiment of the invention; and
[0017] [0017]FIG. 8B illustrates a second part of the process to detect a gesture according to an embodiment of the invention.
DETAILED DESCRIPTION
[0018] An embodiment of the invention may receive a stream of positional data and determine whether a predetermined gesture is represented by the positional data within the stream. The stream may be sampled positional data of a user waving his/her hand in front of a video camera, or a user moving a mouse or a finger moving while in contact with a touchpad, for example. An embodiment may determine whether a gesture (e.g., waving or writing the number “2”) is represented based on a comparison of the data in the data stream with prestored data relating to known gestures. The prestored data relating to known gestures may be stored as a spline such as a B-spline in a memory. A B-spline is a type of parametric curve. A B-spline may be represented by parametric basis functions (or alternatively by knot vectors) and weights. The basis functions (or knot vectors) and weights may be utilized to represent a plurality of curved line segments that together form the B-spline. Each of the curved segments may be associated with a set of control points. Each of the control points is a weighting factor for a basis function which is defined over an interval. Each of the curved segments may have its own set of control points. The curved segments may share some control points with adjacent curved segments.
[0019] A B-spline is one specific type of parametric curve of which there are several. These types of curves may be used extensively in Computer Aided Design (CAD) and other graphics applications requiring compound, non-circular curves.
[0020] A B-spline is defined by an ordered set of control points or control polygon, and parametric basis functions, which determine what path the curve will follow and consequently how the curve will look. A point on a particular curve segment may be calculated by summing the coordinate values of the curve's defining control points after they have been multiplied by the parametric basis functions. For each curve segment, a subset of basis functions are defined. The value of the basis functions across the range of the parameter multiplied by the control point's coordinates define a number of intermediate points, which form a curve when connected.
[0021] An embodiment may compare sets of positional data from the positional data stream with gestures stored in a memory to determine (a) whether a gesture is represented in the data set, and (b) how closely the data set represents the closest matching gesture. The sets of positional data may be formed by the minimal number of data points necessary to represent a gesture, or by the maximum number of data points necessary to represent a gesture. A B-spline may then be determined for the data set, and compared with B-splines represented by the gestures in the memory.
[0022] [0022]FIG. 1A illustrates a spline 100 according to an embodiment of the invention. The spline 100 may be generated based upon a set of input data. For example, a user may move a mouse in different directions, changing the direction of the mouse at various times. A computing device may then acquire positional data from the mouse and supply such positional data to a processing device. The processing device may represent the user's movement of the mouse as the curved spline 100 . The spline 100 may be a B-spline, for example. The processing device may then determine a parametric function to represent the spline 100 . In other embodiments, a positional data input device other than a mouse may be utilized. For example, a camera may sample digital images and determine the movement of an object in the image, such as the user's finger, to determine the positional data.
[0023] [0023]FIG. 1B illustrates the spline 100 and associated control points (first control point 125 , second control point 130 , third control point 135 , fourth control point 140 , fifth control point 145 , sixth control point 150 , and seventh control point 155 ) according to an embodiment of the invention. The spline 100 may be represented as the combination of several curved segments (e.g., first segment 105 , second segment 110 , third segment 115 , and fourth segment 120 ). Each of the line segments may be represented by a parametric curve that is a function of a single variable. The variable may be time, for example. In an embodiment, the first segment 105 may be represented by a function of the first control point 125 , the second control point 130 , the third control point 135 , and the fourth control point 140 . For example, the function for the first line segment 105 as a function of time may be L 1 (t)=C 1 (t)P 1 +C 2 (t)P 2 +C 3 (t)P 3 +C 4 (t)P 4 , where t is a measurement of time, and C 1 , C 2 , C 3 , and C 4 are basis functions, and P 1 , P 2 , P 3 , and P 4 represent the first four control points, 125 , 130 , 135 , and 140 , respectively.
[0024] Accordingly, a spline 100 is a multi-segment curve defined by parametric basis functions (or alternatively by knot vectors) and weights. The actual points that the segments pass through may be defined by the sum of weights times basis functions value, for every point that the basis function is defined. Typically, the basis functions are defined only on a small interval, meaning that the weights only affect the curve in some small locality. A control point may generally only effect a couple of curve segments. In the case of 2-dimensional splines, there are actually 2 weights (one for the x-direction, and one for the y-direction) and these weights are known as the control point.
[0025] In the spline 100 of FIG. 1B, the first 125 , second 130 , third 135 , and the fourth 140 control points may affect the shape of the first segment 105 . The second 130 , third 135 , fourth 140 , and fifth 145 control points may affect the shape of the second segment 110 . The third 135 , fourth 140 , fifth 145 , and sixth 150 control points may affect the shape of the third segment 115 , etc.
[0026] The segments may be joined together at knots. These knots are not the (x, y) coordinates on the curve, rather they define changes in the parametric value used in the basis functions. Knot values can also be used to define the basis functions in a recursive manner. Knot vectors are non-decreasing sequences of knots. Knot vectors are used to define the basis functions. Examples of knot vectors include [1 2 3 4 5] or [1 11 1 2 3 4 5 5 5 5], where “1” represents the first control point 125 , “2” represents the second control point 130 , “3” represents the third control point 135 , “4” represents the fourth control point 140 , and “5” represents the fifth control point 145 . By using the multiple knots in the second knot vector, the basis functions may be manipulated to cause a segment to pass through a point, have a sharp corner, etc. By manipulating the knot vectors, and the subsequent basis functions, non-smooth curves may be formed.
[0027] [0027]FIG. 2 illustrates a gesture recognition device 200 according to an embodiment of the invention. A raw data acquisition device 205 may acquire raw positional data and supply such data to the gesture recognition device 200 . As discussed above with respect to FIG. 1A, the raw data acquisition device 205 may be a computer mouse which acquires positional data based upon directions in which a user moves the mouse, or a touchpad which calculates positional data based upon the movement of a stylus or the user's finger, for example, across the touchpad. The raw data acquisition device 205 may also be a combination of a videocamera and a processor. The videocamera may sample image of the user's movements (e.g., the movement of a neon green pen held by the user) and a processor may extract the positional data for the movement of objects of interest in the image (e.g., the movement of the pen). In other embodiments, an analysis of “pixel flow” in a series of sampled images from the videocamera may be utilized to determine the movement of an object in the sampled images. Pixel flow is the movement of pixels from one image to the next, the pixels being representative of an object in the sampled images. For example, if the user moves his/her hand, the videocamera may sample images of the user, and the processor may determine that the user's hand is moving based upon movement of pixels representing the user's hand. In other words, if the user's hands are a different color than the background, the processor may be able to track the movement of the user's hands based upon the movement of pixels representing the user's hands from one a first position in a first sampled image, to a second position in a second sampled image, to a third position in a third sampled image, etc. In an embodiment, the process may isolate the pixel flow of pixels representing the user's hands from those representing the background based upon the number of pixels moving in similar directions. For example, if the user's hands are closer to the videocamera, they may appear relatively larger than other objects in the image; accordingly, when the user moves his or her hands, more pixels may represent the user's hand than those representing objects in the background. Therefore, the movement of objects in the background may be ignored because a smaller number of pixels representing such background objects are moving from one digital image to the next.
[0028] After the raw data acquisition device 205 outputs the raw positional data, such data may be received by a spline generating device 210 of the gesture recognition device 200 . The spline generating device 210 may have a function of determining a spline, such as a B-spline, based upon the raw positional data. The spline generating device 210 may have its own processor. In other embodiments, a Central Processing Unit (CPU) 230 in the gesture recognition device 200 may control the spline generating device 210 .
[0029] After calculating a spline based upon the raw positional data, the data representing the calculated spline may be output to a normalization device 215 . The normalization device 215 may have a function of normalizing the data representing the calculated spline. The normalization device 215 may process the data representing the calculated spline so that it can be compared with splines representing gestures stored in a gesture vocabulary device 220 . The normalization device 215 may process the data to make it size-indifferent (e.g., a large spline representing a large gesture may be matched with a smaller spline representing the gesture). The data may also be rotation-indifferent, i.e., this may used to remove the effect of the user physically moving while making the gesture (e.g., the user makes a hand signal in front the videocamera while rotating counterclockwise). Finally, the data may also be made translation-indifferent, in order to get the same results regardless of whether the gesture occurs in the upper left of an image sampled from the videocamera, or in the lower right of the image, for example.
[0030] The normalized data may then be output to a goodness determination device 225 , which may have a function of comparing the normalized spline with a set of splines representing gestures stored in the gesture vocabulary device 220 . The gesture vocabulary device 220 may include a memory, for example, to store the splines representing gestures. The goodness determination device 225 may compare the normalized spline with each spline representing gestures and determine a “goodness” value for each of the splines representing gestures. “Goodness” may be a relative measure of how closely the calculated spline matches a stored spline. The gesture may then output data representing the stored spline having the largest goodness value or may output data indicating that the normalized spline does not match any of the stored splines if none of the stored spline have a goodness value above a minimum threshold. A minimum threshold may be utilized to ensure that a minimal amount of similarity exists between the calculated spline and a stored spline. This ensures that where the user makes a gesture not represented within the gesture vocabularly, none of the stored gestures are matched with it.
[0031] The gesture recognition device 200 may also include a memory device 235 to store instructions executable by the CPU 230 or processor in each of the: spline generating device 210 , the normalization device 215 and the goodness determination device 225 , as well as the gesture recognition device 200 itself, for example.
[0032] [0032]FIG. 3A illustrates a raw data acquisition device 205 utilizing a mouse 300 according to an embodiment of the invention. The mouse 300 may output raw data to a position rendering device 305 , which may determine positional data based on the movement of the mouse 300 . The raw data acquisition device 205 may then output the positional data to the gesture recognition device 200 .
[0033] [0033]FIG. 3B illustrates a raw data acquisition device 205 utilizing an I/O device 310 according to an embodiment of the invention. The I/O device 300 may be an infrared device, which may calculate positional data based on an infrared signal received from an infrared glove or boot, for example. As a user moves the glove or boot, infrared signals may be sent to the position rendering device 305 , which may determine corresponding position data, and may transmit such position data to the gesture recognition device 200 .
[0034] [0034]FIG. 3C illustrates a raw data acquisition device 205 utilizing a touchpad 315 according to an embodiment of the invention. A user may touch his/her finger to the touchpad 315 and make gestures such as writing the number “2” on the touchpad 315 , for example. The touchpad 315 may determine positional data based upon where the touchpad 315 is physically contacted by the user. The touchpad 315 may transmit such data to the position rendering device 305 , which may determine corresponding position data, and may transmit such position data to the gesture recognition device 200 .
[0035] [0035]FIG. 3D illustrates a raw data acquisition device 205 utilizing a videocamera 320 according to an embodiment of the invention. The videocamera 320 may be a digital digital videocamera, and may sample images of a user, and transmit such images to the position rendering device 305 . The position rendering device 305 may determine the user's movement based by tracking the movement of pixels of a preset color through consecutively sampled images. For example, the position rendering device may track the movement of a neon green pen held by the user through consecutively sampled images. The movement of the neon green pen may be determined based upon the movement of neon green pixels between consecutively sampled images. In other words, the position rendering device 305 may track the user's movements based upon the “pixel flow” of pixels between consecutively sampled images. The raw data acquisition device 205 may then output the positional data to the gesture recognition device 200 .
[0036] In other embodiments, the color of the user, or an object held by the user, need not be preset. Instead, the position rendering device 305 may determine the user's movements by determining the largest movements between consecutively sampled images (i.e., the position rendering device 305 may ignore smaller movements because they usually do not represent the gesture). In such an embodiment, smaller movements may be ignored by the position rendering device 305 . Such an embodiment may require more processing power to effectively isolate the large movements of the user.
[0037] [0037]FIG. 4 illustrates a spline-generating method according to an embodiment of the invention. The spline-generating method may be utilized to form a spline based upon the raw positional data received from the raw data acquisition device 205 . The spline-generating method may be implemented by the spline generating device 210 , for example. First, the raw position data may be received 400 from the raw data acquisition device 205 . Next, a regression of the positional data may be performed 405 . The regression may be a method of fitting a curve through a set of points minimizing a function until a goodness value is determined. A smoothing process may also be performed 410 . The smoothing process may be a method for modifying a set of data to make a resulting curve smooth and nearly continuous and remove or diminish outlying points. Regression and smoothing are similar methods of fitting curves to a set of data points, with smoothing proving more control over error. The spline-generating method may be implemented by a processor within the spline generating device 210 , or by the CPU 230 , for example.
[0038] [0038]FIG. 5 illustrates an expanded view of the normalization device 215 according to an embodiment of the invention. The normalization device 215 may include a convex hull determination and scale device 500 . A convex hull is the smallest-sized shape which may be used as a container of a set of data points. For example, the convex hull is analogous to stretching a rubber band around the outside of the data points. Once the convex hull of the spline has been determined, the convex hull can be scaled to a predetermined size. The scaling may be used to ensure that a particular gesture can be recognized regardless of whether a small movement was used to make the gestures versus a large movement to make the gesture. For example, if a touchpad 315 is used, the user may use a stylus to make a small “2”, or the user may draw a large “2”. The convex hulls of the spline and the control points representing each of the small and the large “2” may be scaled to the same size. Accordingly, the scaled convex hull of the small “2” would be substantially identical to the scaled convex hull of the large “ 2 ”.
[0039] The normalization device 215 may also include a moment calculation device 505 . The moment calculation device 505 may be used to calculate a moment of the calculated spline and control points. The moment calculation device 505 may also remove the effects of the rotation about a moment while the gesture was made. In other words, if a user were drawing a letter on the touchpad 315 of FIG. 3C while simultaneously physically rotating his/her body, the drawn letter may appear to twist about a moment, thereby skewing the drawing of the letter. The moment calculation device 505 may be used to remove the effect of such rotation after a moment has been calculated for a calculated spline.
[0040] The normalization device 215 may also include a translation invariance device 510 . The translation invariance device may be utilized to remove the effect of the user making a gesture at a varying rate of speed. For example, if the user is drawing a letter on the touchpad 315 , the user might draw the beginning portion of the letter more quickly than the end portion of the letter. Accordingly, if the sampling rate is constant, fewer sampled points may be acquired while the user drew the end portion than those acquired while the user drew the beginning portion. Accordingly, it may be necessary to account for the speed change to prevent erroneous results. The translation invariance device 510 may therefore be utilized to detect and remove the effect of a speed change while the user drew the letter.
[0041] The normalization device 215 may include a processor 515 to control the convex hull determination and scale device 500 , the moment calculation device 505 , and the translation invariance device 510 . Alternatively, each of the aforementioned devices may include their own processors.
[0042] [0042]FIG. 6 illustrates a normalization process according to an embodiment of the invention. First, the calculated spline and control points may be received 600 from the spline generating device 210 . Next, a convex hull of the calculated spline and control points is determined 605 and scaled. The effected of rotation about a moment is then determined 610 and removed. Finally, the effect of a translation change is determined 615 and removed.
[0043] [0043]FIG. 7 illustrates a goodness determination method according to an embodiment of the invention. The goodness determination method may be implemented by the goodness determination device 225 , for example. The goodness determination method may be utilized to compare the calculated spline with splines representing gestures of the gesture vocabulary device 220 . The spline for each gesture may include a knot vector and associated control points. The goodness determination device may have a minimum threshold of “goodness” or correlation that a calculated spline must have with a spline represented in the gesture vocabulary in order to be matched up with the gesture.
[0044] According to the goodness determination method, a spline representing a gesture in the gesture vocabulary may be loaded 700 into a memory. Next, a “distance” between the control points of the calculated spline and the control points of a spline representing the gesture in the gesture vocabulary is determined 702 . The “distance” may be a measurement of how correlated a control point of the calculated spline is with a control point of a spline representing a gesture stored in the gesture vocabulary.
[0045] Each distance measurement may then be squared 705 . In other words, if a calculated spline has “5” control points and a spline representing a gesture stored in the gesture vocabulary also has “5” control points, the distance between the first control point of the caculated spline and the first control point of a stored spline may be determined and calculated. Likewise, the ditance between the second control point of the calculated spline and the second control point of the stored spline may be determined and squared, and so on.
[0046] The calculated squares of the distance measurements may then be summed 710 . The square root of the sum may then be determined 715 . The calculated square root may then be compared 720 with goodness values stored in memory. At operation 725 , if another spline representing another gesture is still present in the gesture vocabulary, the processing continues at operation 700 . If no more splines are left, however, processing proceeds to operation 730 , where a gesture having the highest goodness value is returned, if it exists, provided the square root is below a predetermined threshold value. The gesture that is returned may be the gesture most closely matching a gesture made by the user.
[0047] The mathematical computations by which the goodness value is calculated in the method of FIG. 7 is known as an “L2 norm.” The L2 norm for a set of distances [x1, . . . , xn] is defined as (with x r representing a distance):
L2 norm = ∑ r = 1 n x r 2
[0048] According to the gesture determination method, only the gesture most closely matching (i.e., having the highest goodness value) the gesture made be the user may be determined to be the matching gesture from the gesture vocabulary. The calculated spline from the data representing user's gesture may be compared against each spline representing the gestures stored in the gesture vocabulary.
[0049] Only the gesture most closely matching that of the user's gesture may be returned, provided the goodness value is above a minimum threshold goodness value. Therefore, if the gesture made by the user does not closely match any of the stored gestures, then no gesture may be returned.
[0050] Another aspect of an embodiment of the invention is directed to gesture localization (i.e., determining the presence of a gesture is a set of raw data). Gesture localization may be necessary before the gesture detection described above with respect to FIGS. 1 - 7 may take place. In other words, prior to detecting the gesture and matching it with a gesture of the gesture vocabulary, raw data representing a gesture may first be extracted from a stream of raw data. The key is to determine the existence of an intentional gesture in a raw data trajectory. For gesture localization, the raw data may be analyzed and a pair of pointers may be utilized to indicate the first point of the data representing the start of a gesture and the last point of the raw data representing the end of a gesture.
[0051] Given a trajectory T(x), where T represents a set of the raw data and x represents time, the gesture localization method may be utilized to determine the start and end points, e.g., x start and x end of a gesture in the trajectory T(x). The system may have prior knowledge based on the minimum and maximum acceptable lengths of time during which a complete gesture may be made. For example, a valid gesture may be made between “4” and “8” seconds. In such a situation, an amount of the raw positional data may be tested for “4”-“8” second intervals to determine whether a gesture was likely made.
[0052] [0052]FIG. 8A illustrates a first part of a process to detect a gesture according to an embodiment of the invention. First, counter X is set 800 to “1”. Counter X may be utilized to represent the starting point in a set of data (e.g., set “Z”) of the position data in which to search for a gesture. Next, counter Y may be set 805 to “0”. Data set Z may then by cleared 810 . Data set Z may be utilized to store a set of position points in which to search for a gesture. Next, data point T y+x is added 815 to data set Z. An entire set of positional data points, {T1, T2, . . . , Tn} may be received from the raw data acquisition device 205 and may be continually searched for a gesture. Next, the process may determine 820 whether counter Y is greater than or equal to MIN. MIN may be a value equal to the minimal amount of data points used to represent a known gesture. More specifically, the system may have prior knowledge about the minimum length of time necessary to make a known gesture. Then, based upon the sampling rate of a data acquisition device, the system may then determine how many data point would be present with than known time interval. At operation 820 , if the answer is “no,” counter Y may be incremented 825 , and then processing may continued at operation 815 . Accordingly, the positional data in data set Z is only analyzed for gestures after a minimum number of data points (i.e., MIN) are stored in data set Z. However, at operation 820 , if the answer is “yes,” processing may proceed to operation 830 . If the answer is “yes” at operation 820 , then the system has determined that the minimum amount of data points necessary to represent a gesture is currently stored in data set Z.
[0053] At operation 830 , the spline and control points for data set Z may be determined. Next, the calculated spline may be compared with every spline representing a gesture in the gesture vocabulary, and the gesture having the lowest L2 norm between its control points and the control points for data set Z may be determined 835 .
[0054] [0054]FIG. 8B illustrates a second part of the process to detect a gesture according to an embodiment of the invention. The method may determine 840 whether the L2 norm of T x, x+y is less than any other L2 norm already calculated for data set T. If “no,” processing returns to operation 825 . If “yes,” processing proceeds to operation 845 , where B(X) is loaded with T x, x+y . B(X) may be used to stored the gesture resulting in the lowest L2 norm. Next, the processing determines 850 whether counter Y is greater than MAX, a value representing the number of data points necessary to represent the longest allowable gesture. If “yes,” the value stored in B(X) is returned 855 , as the gesture. In other embodiments, the system may only return B(X) if the L2 norm stored in B(X) exceeds a minimum threshold.
[0055] Counter X may then be incremented 860 , and the process may repeat at operation 805 , where the system may search for gestures within a data set beginning with the second positional point. In other embodiments, counter X may be incremented by a value equal to the total number of data points in data set Z that resulted in the lowest L2 norm, for example.
[0056] In other embodiments, an implementation of a conjugate gradient process may be utilized to determine whether a gesture has been made. In such an embodiment, the system may take turns fixing one parameter and minimizing the other. The conjugate gradient process may be utilized to find the minimum in the data set. In real conjugate gradient methods, a recursive process may be utilized to solve a system of equations. One parameter may be varied at a time, the minimum value may be determined, and this minimum may then be utilized while varying another parameter, etc. The process may repeat until convergence.
[0057] In this case, first fixing the beginning the of data set Z, (i.e., T x ) and searching for the end point of data set Z that yields the data set most closely matching (i.e., having the lowest L2 norm) and vice-versa until convergence. To expedite spline-fitting computations, a course to fine pyramid scheme may also be implemented. The pyramid scheme may be utilized to calculate local values (at a low level in the pyramid) and combine them together (at a higher level in the pyramid). This may be used to calculate local spline segments and combine the segments together into the larger spline. In an embodiment, there may be the possibility that an additional point to the end of a potential spline does not require a recomputation of the complete spline, but instead can use this pyramid scheme technique. Also, a sub-sampling technique may be used where only every 4th data point (or the mean of every 4 data points) to speed up processing, for example.
[0058] Embodiments of the invention may be utilized for a dancing game, for example. The user may perform dance moves in front of a videocamera 320 , and the system may determine gestures (i.e., the dance moves) of the user and may provide an accuracy score that is related to the goodness value of the user's gestures.
[0059] Other embodiments may be used with a sign language instruction program. The user may make sign language signs in front of the videocamera, and the system may determine gestures (i.e., the signs) of the user and may provide an accuracy score that is related to the goodness value of the user's signs.
[0060] Additional embodiments may be used with a writing instruction program, for example. The user may write letters or words on the touchpad 315 , and the system may determine gestures (i.e., written letters or words) and may provide an accuracy score that is related to the goodness value of the user's written letters or words.
[0061] While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of an embodiment of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of an embodiment of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | A gesture classification method includes receiving position data. A detected spline is generated based on the position data. A normalization scheme is applied to the detected spline to generate a normalized spline. A goodness value is determined by comparing the normalized spline with gesture splines representing gestures stored in a gesture database. | 6 |
This application is a nonprovisional application of provisional patent application serial No. 60/181,142 filed on Feb. 8, 2000, this disclosure of which is incorporated herein by reference, as though in full.
BACKGROUND OF THE INVENTION
1. Field of the Invention
2. Brief Description of the Prior Art
Valve regulated lead acid batteries (VRLA) were introduced in the late 1980's as “maintenance free.” In this type of battery, oxygen and hydrogen produced during electrochemical reactions in the battery recombine to maintain an aqueous liquid electrolyte at a constant level with the cell. As a result, these batteries have only a small amount of liquid electrolyte. Discharge of a VRLA battery module to a current compensated voltage of less than substantially 1.5 volts significantly increases the likelihood of irreversible conversion of the active battery material, lead oxide, to lead sulfate due to pinch-off or isolation effects. A drop in capacity proportional to the damage subsequently results.
When VRLA batteries are being charged, they often suffer a charge deficit that cumulatively increases with each charge. The amount of charge deficit varies from battery to battery and those with a smaller deficit are referred to as “more receptive” to charging current and those with a large deficit are “less receptive.” One way of compensating for the charge deficit of a battery is to increase the voltage to which the battery is charged, i.e. the “float” voltage. When the voltage of a battery reaches a manufacturer specified float-voltage, it is deemed fully charged. However, increasing the float-voltage to remedy the charge deficit of a less receptive battery can overcharge those batteries in the string that are more receptive. Overcharging causes disassociation of the electrolyte and consequent gas pressurization in a VRLA battery. If the pressure exceeds the relief valve setting, gas escapes and electrolyte is lost, with permanent loss of capacity as the result. The mismatch in charge receptivity grows with the number of charge cycles. When one battery in the string finally suffers an unacceptable loss of capacity, all of the batteries in the string must usually be discarded, although many of them have substantial useful life remaining.
SUMMARY OF THE INVENTION
A method and apparatus for monitoring the capacity of a valve regulated lead acid battery is disclosed that includes connecting at least one battery monitor to the valve regulated lead acid battery, connecting the battery monitor to a central office through a centralized system using an industry standard data system, and connecting an alarm to the centralized system. Short-term discharge tests are performed on the battery using the battery monitor, which provides input parameters for a neural network and fuzzy logic network used in combination with a prediction algorithm to calculate the predicted capacity. The alarm is activated when said predicted capacity falls below eighty percent, when an individual cell voltage is reduced to 1.95 volts or less, or when a system failure occurs.
In the preferred embodiment of the invention, the battery monitor consists of hardware for monitoring the voltages of each battery cell and currents that are flowing into and out of the battery, and, further, the monitor contains a serial port enabling data to be downloaded onto a network, computer, or printer as well as a real time clock which stamps the tests and data.
The short-term discharge test is preferably a four hour test during which the battery monitor acquires specific data parameters including the cell age, open circuit voltage, voltage after one hour of discharge, voltage after three hours of discharge, and voltage after four hours of discharge. These parameters are used by the neural network to derive three additional parameters including the slope of discharge curve, the delta between the voltages at three and four hours, and the proximity to two volts of the four-hour voltage.
The four-hour discharge test is performed repeatedly as necessary on the battery, while the neural network is trained only once for a specific kind of battery. The neural network is trained in a lab by determining the actual capacity of a battery then using this actual capacity along with the various parameters noted previously to yield a set of neural network coefficients that are used by the fuzzy logic network and the neural network combined with the prediction algorithm to predict the battery capacity.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages of the instant disclosure will become more apparent when read with the specification and the drawings, wherein:
FIG. 1 is a block diagram for the disclosed monitoring system.
DETAILED DESCRIPTION OF THE INVENTION
It is desirable to be able to predict capacity of batteries used in back-up application. An example of a typical back up system that relies on the batteries would be at railroad crossings for the barrier and warning light activation in case of a power failure.
Most batteries exhibit a discharge curve that will allow the use to accurately predict battery capacity. The exception is the VRLA batteries. These sealed, “dry” cell batteries have a very flat discharge curve until capacity reaches a very low value, about ten-percent (10%). At this point, this battery terminal voltage will drop dramatically. The prior art method for determining capacity of these batteries is to discharge the batteries to the lowest system value of 1.75V, and compare the actual time to the calculated time, i.e.
Capacity = Actual Calculated × 100 %
This method is impossible to use in most, if not all, VRLA back-up systems. Unlike primary systems, where the battery can be out of service for a short period of time, because of a back-up system, back-up system batteries must be available at all times in the event of primary system failure. For any type of back-up battery system, the discharge of the batteries to 1.75V would leave the batteries in a heavily discharged condition. In this condition, if the batteries were needed as a back-up power source, they would quickly fail to provide the required current.
It has been determined that a neural network, in combination with a novel prediction algorithm, can be configured to accurately predict the VRLA battery capacity. The basic neural net was designed by Matlab and was modified to determine the weighting coefficients for the prediction algorithm. The input parameters to the neural net were “fuzzified” to incorporate the prediction algorithm's math functionality needed to predict the capacity. However, any equivalent software that can be modified to accept the algorithm as disclosed herein can be used. The capacity prediction algorithm consists of two steps that, when used in combination, provide an unprecedented level of accuracy. The first step is a fizzy logic process that determines the wide range of standardized capacity values for which the particular cell will qualify. The second step uses the neural network to reduce the wide capacity range to a narrow range of approximately 15-20%. The fuzzy logic process contains membership sets of capacity ranges. A membership defines how each point in the input space is mapped to a degree of membership. The degree of membership within a particular capacity range is determined by comparing the cell under test voltages with historical cell voltages from standard cells of the same type. The capacity ranges with positive membership values are used to provide the overall capacity range limits in which the current cell will qualify. The neural network takes the data from the particular cell's four-hour discharge test and determines how much of the broad capacity range is kept.
In the physical arrangement of the disclosed, as illustrated in the block diagram of FIG. 1 , the battery cells 12 are connected in series with a PowerCheck battery monitor 10 . The battery monitor 10 consists of hardware for monitoring the voltages of the battery cells and currents that are flowing into and out of the batteries. All of the data that is needed for the prediction algorithm is acquired with the monitor 10 .
The data required for the neural net is obtained from a short-term, four (4) hour, discharge of the battery. The testing of the battery is automatically run once a year and periodically, as preprogrammed by the system or through manual activation. The system can be preprogrammed to initiate testing of the batteries on any periodic basis. For example, on a monthly basis a twenty (20) minute catastrophic failure test is run to determine if a premature failure will occur on an individual cell. A typical battery bank consists of six (6) or seven (7) separate cells. The entire bank is tested, and the results logged into the system by bank, as well as cell by cell. The four (4) hour discharge is done at a discharge rate calculated from the amp-hour size of the battery and a 24-hour period. The system is monitored to maintain a constant current discharge regardless of load requirements Since in many instances these batteries are used for back up in critical safety areas, such as railroad crossings, even during testing the battery must not be depleted to the extent that it cannot provide immediate full load service. Therefore, the constant current load designed for testing uses a 24-hour load to provide enough data (time loaded) while not significantly depleting the battery. The testing procedure used is a load test recommended by IEEE (Institute of Electrical and Electronic Engineers). Specific data parameters from the four (4) hour test is fed directly into the prediction algorithm. The parameters used are the cells age, open circuit voltage, voltage after one hour of discharge, voltage after three hours of discharge and voltage after four hours of discharge. From these voltage values three additional data points are derived: the three hour slope is calculated from the one and four cell voltages, the delta between the three and four hour voltages and a slope adjusted data point calculated by the difference between the four hour voltage and 2 volts divided by the slope.
The process of learning and testing is as follows. In the lab, a bank of seven cells (same type and ampere-hour size) is fully charged and then discharged at the 24 hour rate until each cell's voltage is 1.75V. This process is done with a data logger/PC recording the cells voltage once per minute. The PowerCheck is used to provide the proper 24 hour rate load to the batteries. Once each cell reaches 1.75V, the actual capacity of the battery is determined by noting the length of time it takes the cell to discharge to 1.75V (typically around 26 hours for a 100% capacity battery). The actual capacity of the battery is determined by the formula: (time to discharge to 1.75V×24 hour discharge rate in amps)/(24×24 hour discharge rate in amps). The parameters that were mentioned above are used to train the neural network/fuzzification network with the actual capacity value used as a target. The results of training a neural network yield a set of coefficients that are programmed into an EEPROM which is inserted in the PowerCheck battery monitor 10 . This constitutes the training of the network.
The four hour tests that are performed at the site location of the PowerCheck (i.e. railroad crossings) use the neural network coefficients to predict the capacity of the batteries at that location. The four hour test logs the parameters mentioned above, inputs them into the neural network and the network outputs a predicted capacity. The parameters obtained from these four hour tests do not provide any additional training data beyond the 24 hour discharge tests performed in the lab. As more 24 hour discharge tests are performed in the lab, the actual capacity and cell voltage data are applied to the training data for the network and new, smarter coefficients are obtained. An example of typical data parameters for a VRLA battery set would be:
Open Circuit Voltage—13.5 volts DC, 2.25 volts per cell Voltage minimum, while still enabling testing,—11.7 volts DC; Dead battery voltage—10.5 volt D.C., 1.75 volts per cell Voltage start—This is dependent upon load applied and charge of the battery. If load is applied for any length of time and the battery is fully charged, the voltage start will be close to the open circuit voltage. Slope—approximately 6 millivolts per hour.
Upon setting up the unit, the age of the battery is entered. Based on the foregoing, the algorithm is fed the cell voltages at specified points in time, the algorithm is then able to obtain additional data points by manipulating the entered cell voltage data.
Since, by its nature, a neural network refines its processes as it “learns”, as more data is obtained, the error margin will be reduced. The neural network predicts capacity at +/−10% error based on about 60 data sets. Optimum reliability in the training of neural networks is achieved by at least 50,000 data sets, thereby reducing the percentage of error.
Dependent upon the application, a variety of types of alarms, or different situations, will need to be activated. In the preferred embodiment, all of the batteries are connected to a centralized system through an industry standard data system, such as SCADA, that collects and transfers data from the field to a central office. In most instances, alarms will be activated if the individual cell voltage is reduced to 1.95 volts or less per cell for one or more cells; the capacity falls below 80%; or a system failure, such as a bad connection, occurs. A serial port in the battery monitor enables the data to be downloaded onto a network, laptop computer or printer. A real time clock that is, preferably, automatically verified and updated, if necessary, through the network, stamps the tests and data. The disclosed is an encapsulated system with any data transfer being from the unit to a laptop, modem or printer. The software used for the printer is contained within the unit and the software for the laptop/PC can be Windows HyperTerminal or an equivalent. The prediction algorithm receives data values from the batteries at one location. For each location and set of batteries, there is one battery monitor 10 that contains the prediction algorithm. Each Powerheck battery monitor 10 can accommnodate up to 7 cells in one set and additional sets will require an additional monitor 10 .
The open, one, three and four hour cell voltages from the foregoing four (4) hour discharge are used in the fuzz portion of the algorithm. The total battery capacity (time to death) is broken into capacity spans of 10%. There is a voltage range associated with each of the 10 spans of battery capacities, which was determined from the previous 24-hour rate discharge lab tests. Each of the open, one, three and four hour cell voltage are compared with the known base lines for the specific battery type to determine which capacity spans the voltages ranges fall within. For example, a one-hour cell voltage of 2.07V will fall into three capacity spans: 70-80, 80-90 and 90-100.
Once the potential capacity spans are determined, another series of calculations occur that indicate the “strength” of the cell's voltage within a particular span. The strength is indicative of the probability of the voltage falling within a specific 10% span. The strength is calculated as follows: the average voltage is calculated for each capacity range using the max and min voltage values. The cell under test voltage (open, one, three or four hour) is divided by this average, then the quotient is subtracted from one and the absolute value of this difference is obtained. Using this same formula, the numbers are obtained from the cell under test open, one, three and four-hour cell voltages. The values of the four are added and the sum is divided by seventy (70) and the quotient subtracted from one. This yields the final strength value for that capacity range which can be positive or negative.
Each capacity range produces a strength value determined by the above formulas and using the same cell under test voltages. The capacity range with the most positive strength value (highest probability that the cell is within that capacity range) is allowed to keep its full 10% range. The neighboring ranges are adjusted by the value of their strength. The range that is immediately above the strongest range gets it strength value added to its lowest capacity value, which yields the upper capacity limit. The range that is immediately below the strongest range gets it strength value subtracted from its highest capacity value, which yields the lower capacity limit. This delta from the two limits produces a high and low range span from the fuzzification portion of the prediction algorithm. For example:
Capacity (%)
Strength Value
90-100
3
80-90
9
<Strongest strength value
70-80
5
Upper capacity limit: 90+3=93
Lower capacity limit: 80−5=75
Final fuzzification capacity range span = 93 − 75 = 18 with the limits as the upper and lower capacity limits.
The neural network portion of the capacity prediction algorithm is used to narrow the capacity span obtained in the fuzzification portion. The neural network receives the open (data point #1), one-hour (data point #2), three-hour (data point #3), and four-hour (data point #4) cell voltages and the age (data point #8), of the batteries. Three more data points are obtained from these input voltages, they are: the slope of the discharge curve (data point #5), the delta between voltages at three and four hours (data point #6), and the proximity to two volts of the four hour voltage (data point #7). The slope (data point #5) of the discharge curve is calculated by taking the difference of the one and four hour cell voltages and dividing by three. The delta (data point #6) between three and four hours is simply the difference between the two values. Data point #7 is determined by subtracting the number two from the four-hour voltage and dividing the difference by the slope (data point #5). This calculation for data point #7 determines the proximity of the four-hour cell voltage to two volts. These eight data points are input to the neural network and the output of the network produces a number between zero and one. The neural network performs its calculations as any standard neural net using the coefficients determined from the training of the network using the lab data.
The output of the neural net is multiplied by the span of the capacity range obtained from the fuzzification portion (18 in the example above). This product is added to the low range value (75 in the example above) and this sum is the final capacity prediction of the algorithm. | A method and apparatus for monitoring the capacity of a valve regulated lead acid battery comprising at least one battery monitor connected to the valve regulated lead acid battery; a centralized system connecting the battery monitor through an industry standard data system to a central office; and an alarm connected to the centralized system; wherein, a short-term discharge test is performed on the battery using the battery monitor which provides input parameters for a neural network and fuzzy logic network used in combination with a prediction algorithm to calculate the predicted capacity; and, wherein, the alarm is activated when said predicted capacity falls below eighty percent, when an individual cell voltage is reduced to 1.95 volts or less, or when a system failure occurs | 6 |
REFERENCE TO RELATED APPLICATION
Certain features of the apparatus shown and claimed in the present application have been disclosed in our prior copending application Ser. No. 478,519 filed June 12, 1974, now U.S. Pat. No. 3,926,230.
BACKGROUND OF THE INVENTION
This invention relates to improved apparatus for collecting and disposing of gasoline vapors or other flammable vapors which might otherwise escape into and pollute the atmosphere, as for instance during the filling of fuel into an automobile tank at a service station.
With the greatly increased emphasis in recent years on attaining improvement of environmental conditions, considerable effort has been expended, among other things, in attempting to prevent escape of gasoline vapors into the atmosphere at service stations, and particularly during the filling of gasoline into an automobile tank, as well as during the filling of the service station tanks themselves from a fuel delivery truck. One type of proposed prior art arrangement for the purpose is disclosed in U.S. Pat. No. 3,581,782 issued June 1, 1971, in which vapors withdrawn from the vicininty of a service station dispensing nozzle are absorbed onto a mass of activated charcoal or other adsorbent material, and are ultimately desorbed from that material for disposal. Various forms of the invention shown in that patent dispose of the vapors by injection into the carburetor of the engine of a fuel delivery truck, or refrigeration to liquify the vapors and return them to a main storage tank, or oxidation in a catalytic converter. At one point, the patent mentions that the vapors may be "burned in a controlled system", but gives no details of the type of system contemplated.
SUMMARY OF THE INVENTION
The major object of the present invention is to provide an improved vapor recovery system which is capable of collecting and disposing of flammable vapors from a service station or the like with increased effectiveness as compared with prior systems of which I am aware. A system embodying the invention is capable of collecting close to 100 percent of the vapors which would otherwise escape into the atmosphere during a fueling operation, and does so with no disruption of or adverse effect on the dispensing procedure, and at a minimum cost of operation. Further, the equipment can be essentially silent in operation, and can function over very long periods of time with little or no maintenance.
In the equipment, the vapors are withdrawn from the vicinity of the fuel dispensing nozzle or nozzles by a vapor pump, and are ultimately delivered to a burner system in which complete combustion converts the vapors to carbon dioxide and water, which are then emitted into the atmosphere without pollution thereof. Some of the vapors collected by the pump may be returned into the main underground storage tank or tanks of the service station, to replace the liquid removed from those tanks by the dispensing operation. Any excess vapors which may be accumulated at a particular time are adsorbed onto an adsorbent substance in a filter cannister or cannisters, with intermixed air ultimately discharging to the atmosphere from the cannisters after adsorption of the vapors. At appropriate times, the flow of air may be reversed, to remove the vapors from the adsorbent material, and feed the air-vapor mixture to the burner system.
Certain particular features of the invention relate to a preferred burner arrangement in which two different burners are employed for burning vapor-air mixtures of different B.T.U. contents, with automatic control means serving to shift between one of the burners and the other in accordance with the B.T.U. content of the mixture. The automatic control equipment attempts to light the burners intermittently, preferably in response to manual actuation of a control part at the commencement of a dispensing operation. A control timer may attempt to light the two burners in a predetermined sequence, to first ignite a burner in which low B.T.U. content vapors are burned without addition of extra air at the burner, and then attempt to light a second burner designed especially for handling air-vapor mixtures of higher B.T.U. content, with the addition of extra air at that burner. When the adsorbed vapors have ultimately been removed fairly completely from the adsorption bed, the high B.T.U. content burner may go out, or reduce its flame to a level causing response of an automatic control element, with the latter then causing the remaining vapors to be diverted to and burned by the low B.T.U. content burner, until substantially all of the vapors are removed from the adsorbent substance which is then left in a clean condition until the next successive dispensing operation.
As another feature of considerable significance to the invention, it is preferred that the apparatus include a vapor pump interposed operatively between the adsorbent chamber and burner or burners, with the pump acting to take suction through the adsorbent material and acting to discharge an air-vapor mixture to the burners. In one form of the invention, a single vapor pump may serve dual purposes as this burner feed pump and as the previously mentioned vapor pump which withdraws vapors from the vicinity of the fuel dispensing nozzles. A unique piping arrangement permits this dual functioning of a single pump. In another form of the invention, two separate pumps are employed for accomplishing the two purposes.
Still another feature of the invention resides in the structure of a burner unit which may be employed in the equiqment, and in which products of combustion from a burner pass upwardly through a vertically elongated stack to ultimately discharge from the top of the stack to the atmospere, with incoming air being directed downwardly along a passage at the outside of the stack, to maintain the outer walls of the unit cool and isolate the burner flame or flames from direct lateral communication with the outside of the unit.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiments illustrated in the acompanying drawings in which:
FIG. 1 is a representation of a service station installation embodying the invention;
FIG. 2 is an enlarged fragmentary showing of one of the fuel dispensing nozzles of the FIG. 1 apparatus;
FIG. 3 is a flow diagram illustrating the vapor recovery system of the FIG. 1 apparatus;
FIG. 4 shows the electrical control circuitry of the FIG. 1 apparatus;
FIG. 5 is a vertical section through the vapor burning stack unit of the invention, taken on line 5--5 of FIG. 1;
FIG. 5a is a vertical section on line 5a--5a of FIG. 5;
FIG. 6 is an enlarged horizontal section taken on line 6--6 of FIG. 5;
FIG. 7 is a further enlarged vertical section taken on line 7--7 of FIG. 6;
FIG. 8 is a flow diagram representing fragmentarily a variational form of the invention; and
FIG. 9 is an electrical control circuit representing fragmentarily a circuit which may be utilized in conjunction with the FIG. 8 arrangement.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates generally at 10 a service station island having a number of fuel dispensing pump assemblies 11 for filling gasoline or other fuel into the tank 12 of a motor vehicle 13. The pump assemblies or fuel dispensing units 11 receive fuel from one or more underground tanks 14 through lines represented at 15, with each dispensing unit containing a pump 16 driven by an electric motor 17. Upon energization of motor 17, pump forces the flammable fuel from tank 14 through a conventional flexible hose 18 to a dispensing nozzle unit 19 whose discharge end 20 is adapted and dimensioned to project into the filling neck 21 of vehicle tank 12 to deliver fuel thereto. The nozzle unit 19 has the usual manually actuated trigger element 22, which actuates a valve 23 to start and stop the discharge of fuel from the discharge portion 20 of the nozzle assembly.
In accordance with the usual practice, each of the dispensing units or pump assemblies 11 has a manually actuated element 24 of some type which serves when manually moved between two different predetermined positions, as from the full line position to the broken line position represented diagrammatically in the circuitry of FIG. 4, to condition that particular dispensing unit for delivery of fuel from its nozzle device 19. Preferably, such actuation of element 24 serves a number of different functions, including a usual first function of commencing fuel delivering operation of pump 16, a usual second function of freeing the associated nozzle unit 19 for removal from a storage recess 28 in a side of the housing 29 of dispensing unit 11, and an additional function of commencing operation of a vapor pump 30 (FIG. 3) and driving motor 31 for commencing withdrawal of vapors from the vicinity of the nozzle. With regard to the second of these functions, the element 24 may take the form of a lever which swings between a position in which it blocks removal of the nozzle from recess 28, to lock the nozzle against removal from housing 29, and a retracted or inactive second position in which lever 24 is out of the path of and permits removal of nozzle 19 from recess 28.
For removing the fuel vapors from the vicinity of nozzle unit 19 during a dispensing operation, each such nozzle carries a vapor pick-up element 32 (FIG. 2) which delivers vapors to a flexible suction hose 33 extending along and parallel to the corresponding fuel delivery hose 18. In the preferred arrangement, a valve 34 closes off the flow of vapors from pick-up element 32 to hose 33 except during delivery of liquid through nozzle unit 19. Valve 32 is designed to automatically open when fuel is being fed through the outlet portion 20 of the nozzle into tank 12, and for this purpose may typically be mechanically or otherwise operated by the same trigger element 22 which opens valve 23. FIG. 2 represents diagrammatically at 35 such a mechanical actuating mechanism which simultaneously opens fuel valve 23 and vapor valve 34 in response to operation of trigger 22. Alternatively, the valve 34 may be of a known type which is responsive to the flow of liquid through the nozzle to automatically open vapor valve 34 to an extent proportional to the rate of liquid flow.
When a particular one of the vapor shut-off valves 34 is opened, it places the connected suction hose 33, through a flame arrestor 36, in communication with an underground suction suction line 31 leading to the previously mentioned motor driven vapor pump 30, which acts when in operation to maintain a sub-atmospheric pressure in line 31 and the pick-up element 32 on the nozzle, with the latter then acting to withdraw fuel vapors and some intermixed air from the vicinity of nozzle unit 19, and particularly its discharge portion 20, to thus prevent escape of the vapors outwardly past the nozzle during a filling operation. Pick-up element 32 is disposed about the tubular nozzle structure, and contains an appropriate suction passage which preferably has an annular open end at the location 37 of FIG. 2, positioned to be received within the filling neck 21 of the vehicle tank during a filling operation. Vapors thus enter the inlet opening 37 at the end of pick-up element 32, and flow through a passage within the interior of element 32 to valve 34 and vapor removal hose 33. Pump 30 is capable of maintaining a sufficiently rapid flow of air into element 32 and hose 33 to effectively withdraw all vapors from the vicinity of the nozzle without the necessity for maintaining a seal between the filling neck 21 and the nozzle or pick-up element 32. The vapor pump may therefore actually draw some air into neck 21 for admixture with the fuel vapors, so that both air and fuel enter the suction line 31. This line 31 has a downwardly inclined portion 38 (FIG. 1) which communicates at 39 with a drain line 40 through which any liquid contained within the suction line can drain back by gravity into one or more of the tanks 14 past a swing check valve 41. The remaining vapors, free of any liquid, then flow from the point 39 slightly upwardly at 42 for delivery to vapor pump 30 past a flame arrestor 43.
The vapor from the discharge side of pump 30 flows through a line 44, which leads into three different vapor discharge lines 45, 46 and 47. The first of these lines, number 45, delivers vapor through a pressure regulating valve 48 to a burner system 49 which will be described in greater detail at a later point. Vapor which does not enter this line 45 passes through a check valve 50, from which it may enter either the line 46 flowing to a first of two adsorption chambers 51 and 52, or the line 47 which connects through a check valve 53, flame arrestor 54, and float check valve 55 with a vent line 56 extending upwardly from the underground storage tanks 14. The check valves 50 and 53 pass fluid only in the directions indicated by the arrows in FIG. 3. Float check valve 55 acts to pass vapors in either direction therethrough, that is, either for return of some of the pump vapors to tanks 14 or flow of vapors from the tanks to adsorption chambers 51 and 52, but contains a float which is responsive to a rise in the liquid level to the height of valve 55 to close off this valve and thus prevent the flow of any liquid past valve 55 to the adsorption chambers 51 and 52. The upper end of the vent line 56 from tanks 14 may be connected to a pressure/vacuum vent cap 57, which will discharge vapors from line 56 to the atmosphere in response to the attainment of a predetermined very slightly super-atmospheric pressure within line 56, and which will admit air from the atmosphere into line 56 in response to the development of a predetermined very slight sub-atmospheric vacuum in line 56. Liquid is filled into tanks 14 through conventional vertical fill pipes 58, which extend upwardly to the surface of the earth and have removable caps 59.
The line 60 upwardly beyond float check valve 55, in addition to being connected to the previously mentioned check valve 53, is also connected through an additional opposite flow check valve 61 and connected line 62 to the upper end of adsorption chamber 51. The upper end of the second adsorption chamber 52 is connected through a flame arrestor 63 with the atmosphere, with an additional check valve 64 being connected between the upper ends of the two adsorption chambers and permitting flow leftwardly in FIG. 3. The lower ends of the two adsorption chambers 51 and 52 are interconnected by line 65, connected to a line 66 leading through a check valve 67 to a point of connection 68 to the suction line 69 of vapor pump 30, so that the vapor pump can take suction from the adsorption chambers.
Each of the adsorption chambers includes an outer hollow shell 70, filled with a mass or bed of an adsorbent substance 71, such as activated charcoal, capable of adsorbing the flammable gasoline vapors and thereby separating the vapors from any air intermixed therewith, and then permitting the escape of the cleaned air into the atmosphere at 72. At various times, these adsorbed vapors are withdrawn from the material 71 by downward flow of clean atmospheric air through the beds, and are then burned in the combustion apparatus 49.
As seen in FIGS. 5 to 7, this combustion unit 49 preferably includes two burners 73 and 74 (or two sets of burners if desired), the first of which (73) is a relatively large burner and acts to burn vapors which when delivered through line 75 of FIG. 3 are in a relatively rich vapor-air ratio, and have a relatively high B.T.U. content, desirably between about 180 and 1,000 B.T.U.s per cubic foot of mixture. For this purpose, the line 76 which conducts the rich vapor-air mixture to burner 73 has connected into it an air inductor 77 which communicates with the atmosphere in a relation drawing additional air into line 76 for admixture with the supplied vapor and air to reduce the ratio of fuel to air to a value effectively combustible by burner 73.
The second burner or burner assembly 74 is utilized for burning a supplied mixture of lower B.T.U. content, (desirably between about 50 and 200 B.T.U.s per cu. ft.), and consequently its supply line 78 does not contain an air inductor. Thus, burner 74 burns the supplied mixture without the addition of more air. In the particular arrangement illustrated, the burner assembly 74 includes three individual burner elements 79, which may be cup shaped as shown in FIG. 7, and have short inlet tubes 80 projecting upwardly thereinto from line 78 to introduce the vapor-air mixture into the cups. These elements 79 are positioned closely enough together that ignition of one of the elements will cause ignition of all three. Both the burner 73 and the burner assembly 74 are lighted by a common spark type ignitor 81 positioned between the two burners, and which is close enough to each burner to cause its ignition if flammable vapors in sufficient quantity are supplied thereto. The two supply lines 76 and 78 receive vapors from the previously mentioned line 75 downstream of valve 48, and contain a pair of electrically operated solenoid valve 82 and 83 for closing off the flow of vapors through the two lines, with flame arrestors 84 being interposed downstream of the solenoic valves.
With reference now to FIGS. 5 and 6, the combustion unit 49 includes a vertical stack 85 defining an updraft passage 185 within the lower portion of which the two burners 73 and 74 are located, so that the gases of combustion pass upwardly within passage 185 for discharge from the upper end thereof. More particularly, the stack 85 may be of square horizontal cross section, having four vertical side walls 86, 87, 88, and 89 as seen in FIG. 6. The lower ends of these four walls of the stack may terminate at locations 90 spaced above an imperforate bottom wall 189, so that inlet air can flow through the gaps 91 to the underside of the burners. About stack 85, an outer imperforate housing 92 of larger square horizontal cross section extends vertically upwardly from the bottom wall 189 to an upper edge 94 spaced beneath a horizontal wall 95 to define gaps 96 through which air may enter the upper ends of the passages 97 at the various sides of stack 85. Perforated screens 196 may be provided in these gaps 96. Four additional walls 98 may extend downwardly from top wall 95 at locations spaced outwardly with respect to the four walls of housing 92, to define short upflow passages 99 communicating with the atmosphere at their lower ends through inlet screens 100. Thus, all inlet air from the atmosphere must flow upwardly within passages 99, and then reverse its flow to pass downwardly within passages 97, to then enter the lower end of the stack through the gaps 91 in flowing downwardly, the relatively cool air within passages 97 absorbs heat from the walls of stack 85 in a relation shielding outer housing 92 from that heat and maintaining that housing in cool condition. Further, the circuitous path which air must follow to the burners isolates the burners from direct lateral low level communication with the atmosphere and permits such communication only through the high level air inlets at 100, to prevent accidental ignition of any combustable material in the vicinity of burner unit 49 by the burners. The vertical extent of the stack 85 is such as to assure complete combustion of all vapors before they reach the upper end of the stack. At the upper end of the stack, the products of combustion discharge laterally through two oppositely directed perforated plates or screens 101. A top wall 102 extends across the upper end of the stack in spaced relation to wall 95, and may be connected by spaced vertical walls 201 to two opposite ones of the walls 98, to define at the other two sides of the stack the lateral discharge passages 103 within which screens 101 are located.
To describe now the electrical control circuitry of FIG. 4, each of the dispensing units includes, in association with its nozzle releasing manually actuated lever 24, a pair of electric switches 104 and 105, which are normally open and are closed by swinging movement of the lever 24 to the position in which it permits removal of the nozzle for a dispensing operation. Switch 105 closes a circuit from power supply 106 to the gasoline pump motor 17 of that unit 11, to start the pumping of liquid fuel through hose 18 to the nozzle. Closure of the second switch 104 closes the circuit through two lines 107 and 108 to the coil 109 of a relay 110, to close both of the contacts 111 and 112 of the relay. Simultaneously, closure of switch 104 also energizes the motor of a rotary timer 113, which has a 30 second cycle and acts by cams or otherwise during each cycle to first close upper contact 213 of the timer for a predetermined short interval (preferably two to three seconds), with the lower contact 114 being closed immediately after opening of upper contact 213 and remaining closed for a short interval (desirably two to four seconds). During the remainder of the thirty second cycle of timer 113, both of the switches 213 and 114 are open. The timer repeats this cycle continuously as long as it is energized. The periods of closure of switches 213 and 114 are long enough to enable ignitor 81 to light either of the burners 73 or 74 if sufficient fuel is present to burn.
The closure of lower contact 112 of relay 110 closes a circuit through line 115 to vapor pump motor 31, to commence the operation of vapor pump 30 for creating a sub-atmospheric pressure in line 42 acting to draw vapors by suction from the vicinity of the dispensing nozzle 19 through hose 33, as soon as the delivery of gasoline is commenced by actuation of trigger 22. The closure of upper contact 111 of relay 110 energizes a line 116 leading to the timer. When the first movable contact 213 of the timer closes during a first cycle of the timer, it closes a circuit through the normally closed movable contact 117 of a thermal time delay relay 118, to the coil 119 of a load relay 120, with the second side of coil 119 being connected to the previously mentioned power supply line 107. This closes the two contacts 121 and 122 of relay 120, the first of which contacts in turn closes a circuit through a line 123 to the coil 124 of a relay 125. The lower contact 126 of relay 125 closes a holding circuit to the vapor pump motor 31, while the upper contact 127 of relay 125 closes a holding circuit through a line 128 to the line 129 leading to thermal time delay relay 118, to thereby maintain line 129 energized after contact 213 of the timer opens. Energization of line 123 by relay 120 acts also to deliver power to the upper one of two normally closed contacts 130 of a burner selecting double-pole double-throw relay 131, and to the upper one of two normally open contacts 132 of the same relay. Contacts 130 act when closed to energize solenoid valve 82 for admitting a flammable vapor-air mixture to the low B.T.U. burner assembly 74, while closure of contacts 132 upon energization of the coil 133 of relay 131 opens the circuit to solenoid valve 82 and closes the circuit to solenoid valve 83 to admit vapor and air to burner 73.
In addition to its discussed effect of energizing line 123, closure of movable contact 121 of relay 120 also closes the circuit to the upper one of two normally open contacts of a conventional flame rectification relay 135. The details of such flame rectification relays are well-known in the art, and have not been illustrated in detail in FIG. 4. For simplicity, this relay has been illustrated only diagrammatically by the broken line box 135 of FIG. 4, with the coil of the relay being represented at 136, and acting when energized to open movable contact 137 and close movable contact 138. The flame rectification relay is connected to a flame sensing rod 139 which has portions extending over the flame area of each of the two burner units 73 and 74. An electrical circuit is completed between the flame rectification relay and each of the burners, as by grounding these elements at 140. The flame rectification relay contains a power source which causes current to flow between each of the burners and rod 139 whenever the burner is ignited, as a result of the ionization of the gases between these elements produced by the flame extending upwardly from the burner to rod 139. When this current flows as a result of burning of gases in either of the burners 73 or 74, the resultant current passing from the burner to rod 139 causes energization of coil 136 of the flame rectification relay, to pull contacts 137 and 138 leftwardly. Until such ignition of the one of burners, contact 137 of relay 135 is closed to complete a circuit through relay 118 and contact 122 of relay 120 to the primary side of spark coil 141, and in parallel to the heater coil 142 of thermal relay 118. So long as the primary of spark coil 141 is left energized, igniter 81 produces a continuous spark attempting to ignite the two burners 73 and 74. If the igniter is thus energized for more than a predetermined very short interval sufficient to light the burners if fuel is present (say for example more than five seconds), thermal relay 118 opens to break the main power supply line 143 to relay 120 and thereby deenergize holding relay 125, solenoid valves 82 and 83, spark coil 141 and coil 142 of relay 118.
Besides being connected into the circuit to line 123, the left hand movable contact 121 of relay 120 also acts when closed to energize the upper one of two normally open contacts 134 associated with movable contact 138 of flame rectification relay 135. When this contact 138 is closed, as a result of the sensing of flame in either of the burners by rod 139, contact 138 closes a circuit to the upper one of two normally open contacts 145 of relay 131, whose closure by movable contact 146 of relay 131 closes a holding circuit to coil 133 maintaining relay 131 in its energized state until contacts 134 of the flame rectification relay are opened.
The second movable contact 114 of timer 113 acts through a line 147 to close a primary energizing circuit to coil 133 of relay 131 during the short interval of closure of contact 114 on each cycle of the timer, to thus during that interval deenergize solenoid valve 82 and energize solenoid valve 83 to attempt to light 73 if enough high B.T.U. vapor mixture is present.
To describe briefly a cycle of operation of the apparatus of FIGS. 1 to 4, assume that the carbon cannisters 51 and 52 are initially substantially free of hydrocarbon vapors, and that none of the dispensing units 11 is in operation. In this condition, the vapor pump 30 and the burners are all inactive. When an operator then desires to dispense fuel into a vehicle, he first actuates lever 24 of one of the units 11, to free the associated nozzle 19 for insertion into the filling neck of the vehicle tank, to deliver liquid thereto. The actuation of lever 24 closes a circuit to fuel pump motor 17, to deliver fuel to the nozzle, and also starts operation of timer 113 of FIG. 4 and closes relay 110 to commence operation of vapor pump motor 31. When valve 34 of the nozzle assembly is opened during delivery of fuel to the tank, vapor pump 30 draws vapors from the vicinity of the nozzle through lines 42 and 69, and discharges the vapors through line 44 to the three lines 45, 46 and 47. If enough vapors are present for ignition in the burners, they are burned within unit 49. Enough vapors to replace the amount of liquid withdrawn from storage tanks 14 returns to those tanks through line 47, and excess vapors pass through line 46 into chamber 51, to pass downwardly through the carbon within that chamber, then cross through line 65 to the bottom of chamber 52, and pass upwardly through the carbon in that second chamber. The carbon adsorbs all of the vapors within chambers 51 and 52, and discharges only cleaned air to the atmosphere at 72.
After completion of a dispensing operation, vapor pump 30 remains in operation, and then takes suction through check valve 67 from the adsorption chambers 51 and 52, rather than vapor collection line 42, to desorb the collected vapors from the carbon within chambers 51 and 52, and continue delivery of a vapor-fuel mixture to the burners through line 45 so long as there are enough flammable vapors to support combustion in the burners. During this desorbing process, air flows downwardly through flame arrestor 63, with some of the air flowing down through chamber 52, and the rest of the air flowing in parallel through check valve 64 and then downwardly through chamber 51, and with the two streams then meeting at line 65 to thus draw air through both of the carbon beds. The vapor pump 30 therefore serves two different functions in two different conditions of the apparatus, either to withdraw collected vapors from the vicinity of the nozzles, or to take suction downwardly through the carbon beds during a desorbing process.
As long as dispensing continues, timer 113 turns continuously to attempt to ignite each of the burners 73 and 74 during each 30 second cycle. The short interval of closure of timer contact 213 during each cycle energizes relays 120 and 125 as discussed, to close a circuit through contacts 117, 122 and 137 to the spark coil to attempt to light the burners. During this interval, solenoid valve 82 is open to attempt to light the burner 74. When contact 114 of timer 113 subsequently closes for a short period, this energizes relay 131 to close the circuit to solenoid valve 83 instead of solenoid valve 82, thus stopping the burning of gases within burner 74, and attempting to ignite the burner 73. If a rich enough mixture for combustion in burner 73 is not present, it will not ignite, and upon opening of timer contact 114 relay 131 will return to its normal condition for opening the circuit to solenoid valve 83 and closing the circuit to solenoid valve 82, with resultant relighting by igniter 81 of low B.T.U. content burner 74. If this burner does light, the flame will be sensed by flame rectification relay 135, whose coil 136 will be energized to stop the spark. Ultimately, the mixture will become rich enough for combustion in burner 73, which burner will therefore be ignited during one of the intervals of closure of timer contact 114, to deenergize the ignitor 81 and close a holding circuit through contacts 134 and 145 acting to maintain relay 131 energized. The apparatus will remain in this condition, with the rich mixture burning in burner 73, until the mixture becomes so lean that the flame in burner 73 goes out or falls to a predetermined level at which it does not contact rod 139 and is not sensed by that rod. This releases the contacts of flame rectification relay 135 for rightward movement, to open the holding circuit to relay 131, and allow it to return to its normal condition in which solenoid valve 82 rather than solenoid valve 83 opened, with the igniter 81 then attempting to ignite the reduced B.T.U. content mixture in burner 74. This burning is sensed by flame rod 139, which deenergizes the igniter 81, and the combustion in burner 74 continues until the carbon beds are substantially free of hydrocarbons, at which time the flame in burner 74 goes out or falls to a level at which it cannot be sensed by flame rod 139 to again release the flame rectification relay to energize spark coil 141 and igniter 81 for a further try at ignition and at the same time energize heater 142 of relay 118, which ultimately opens if the igniter cannot produce a flame within 5 seconds, thus deenergizing the entire relay system to its original condition until the next dispensing operation.
FIG. 8 is a fragmentary flow diagram of a variational arrangement which may be considered as identical with that of FIG. 3 except that two seperate vapor pumps 30a and 130a are provided for forming the described dual functions of the single pump 30 of FIG. 3. In FIG. 8, a flame arrestor 43a corresponds to flame arrestor 43 of FIG. 3, and is connected through line 42a (corresponding to line 42) to the fuel dispensing pump assemblies and storage tanks in the same manner illustrated in FIG. 3. The two adsorption chambers 51a and 52a of FIG. 8 correspond to chambers 51 and 52, and are connected to the storage tanks etc. in the same manner as in FIG. 3. The lines 46a and 47a of FIG. 8 correspond to lines 46 and 47 of FIG. 3, with the discharge line 44a from vapor pump 30a connecting to these lines as in FIG. 3, but with the deletion of the check valve 50 of FIG. 3 and the additional discharge line 45 leading to the burners. The second vapor pump 130a takes suction from line 65a interconnecting the lower portions of the two adsorption chambers 51a and 52a, and discharges to the burners through a pressure regulator valve 48a corresponding to valve 48 of FIG. 3.
During a dispensing operation with the equipment of FIG. 8, pump 30a operates to draw vapors from the dispenser nozzles and discharge the vapors partially through line 47a to the storage tanks 14 of FIG. 3, and partially through line 46a to adsorption chambers 51a and 52a, with these vapors passing downwardly through the lower portions of chamber 51a and upwardly through the chamber 52a for adsorption onto the material of the carbon bed, with discharge of the cleaned air upwardly from the upper end of chamber 52a to atmosphere. During the dispensing operation and as long thereafter as a burnable mixture is present in either of the burners 73 or 74 of FIG. 6, the burner pump 130a of FIG. 8 is kept in operation to deliver the vapor-air mixture to the burners.
The circuitry for controlling the variational arrangement of FIG. 8 is the same as that illustrated in FIG. 4 except for the changes represented in FIG. 9. More particularly, it will be noted in FIG. 9 that lower movable contact 126a of relay 125a (corresponding to relay 125 of FIG. 4), instead of being connected to motor 31a of vapor pump 30, is connected into the circuit to motor 131a of burner pump 130a, to keep that burner pump energized as long as relay 125a is actuated. When relay 125a is ultimately deenergized, as a result of opening of the thermal time delay relay 118 of FIG. 4 as discussed above, the burner pump motor 131a is similarly deenergized to become inactive along with the rest of the equipment until the next successive dispensing operation. The timer 113a and relay 110a of FIG. 9 are of course identical to corresponding units 113 and 110 of FIG. 4, and have been included in FIG. 9 to assure an adequate understanding of the circuit changes represented by that figure.
While certain specific embodiments of the present invention have been disclosed as typical, the invention is of course not limited to these particular forms, but rather is applicable broadly to all such variations as fall within the scope of the appended claims. | A vapor recovery system in which gasoline vapors or other flammable vapors are withdrawn from the vicinity of a like, and are disposed of by combustion in a burner system, preferably consisting of two burners selectively usable for burning vapor-air mixtures of different B.T.U. contents. The vapors may be temporarily stored by adsorption onto an adsorbing substance, and then be removed from that substance by conducting a flow of air therepast. | 1 |
This application is a divisional of application Ser. No. 08/684,389, filed Jul. 19, 1996, now U.S. Pat. No. 5,783,127.
BACKGROUND OF THE INVENTION
The invention relates to a method and an apparatus for spinning a synthetic multi-filament yarn.
A method and apparatus of the described type is known, for example, from U.S. Pat. No. 3,103,407, wherein a freshly spun synthetic filament yarn (polyester) is advanced by means of a withdrawal roll or godet from a spin zone to a draw zone and drawn between the withdrawal roll and a draw roll or godet. In this process, the yarn is heated in two stages by contacting the heated withdrawal roll and a heated metal plate directly adjacent thereto. The withdrawal roll is heated to a temperature from 60 to 90° C. and the metal plate to a temperature from 160 to 200° C. The withdrawal speed is in a range of less than 1,000 m/min.
The above-described method has the disadvantage that the heating of the yarn is dependent exclusively on the contact between the heated surfaces and the yarn. Furthermore, the long contact length and high contact force lead to increased yarn frictions, which have disadvantageous effects on the yarn quality. These adverse effects amplify rapidly at higher withdrawal speeds, so that an even heat transfer is no longer possible.
It is an object of the present invention to achieve in the thermal treatment of an advancing synthetic multi-filament yarn, which may be polyester, polyamide, polytrimethylene terephthalate, and polypropylene, a uniform heating of the yarn with a correspondingly uniform drawing, and uniform, well adjustable yarn properties.
SUMMARY OF THE INVENTION
The above and other objects and advantages of the present invention are achieved by the provision of an apparatus which includes an extruder for extruding a polymeric melt to form a plurality of advancing filaments which are gathered to form an advancing yarn, and a drawing system for drawing the advancing yarn as it advances through a drawing zone. A heater is provided for heating the advancing yarn in the drawing zone, and the heater includes a first heater over which the yarn is guided and a second downstream heater which has an elongate heating surface and a plurality of guides for guiding the yarn along the heating surface. After the heat treatment, the advancing yarn is wound into a package.
During at least one of the first and second heat treatments, the yarn is subjected to a temperature higher than the melt point temperature of the yarn, which is at least 100 degrees C. higher than the melt point temperature of the yarn and preferably between about 200 and 300 degrees C. higher than the melt point temperature of the yarn. Also, during the drawing step, the yarn is subjected to a tension which is sufficient for the plastic deformation of the yarn during or immediately downstream of the first heating step.
The high temperature of the heat treatment causes immediately a shocklike heating of the yarn shortly after its entry into the heating zone. This allows, on the one hand, to accurately localize a so-called yield point. The yield point is a very narrow range of the yarn, in which plastic deformation starts by a uniform flow. On the other hand, the shocklike heating results preferably in structural changes. The mechanical stress on the yarn caused by friction is minimized, so that the yarn tension, which is necessary for the plastic deformation, follows a constant course.
A special advantage is that a continuous drawing and setting do not require an increase in the yarn tension, but that same may remain substantially constant. The shocklike heat treatment, along with the draw tension, allows to realize already an adequately satisfactory setting effect. A further advantage is that it is possible to omit means, such as, for example godets, for increasing the yarn tension between the individual stages of the heat treatment.
A variant of the method includes increasing the yarn tension within the draw zone, which may be used advantageously for processing materials, such as, for example, polypropylene, which require a subsequent drawing.
The first heat treatment may include guiding the advancing yarn over a first heating surface which has a surface temperature above the melt point of the yarn material. This embodiment has the advantage that the heat treatment in the first stage may occur, in particular, by a heated draw pin, so that despite a small contact length and high withdrawal speeds, the high surface temperatures cause the yield point to form on the draw pin. The draw pin may have a curved surface with a radius of, for example, 10 cm or even far higher. The draw pin is mounted stationarily and not for rotation, and its surface is contacted or looped by the yarn in part. Due to the high surface temperatures, the contact length and the contact force may be kept very small. This allows to lessen the wear of the draw pins. Furthermore, the frictional forces on the yarn are very small, so that damage to the yarn is prevented.
It should expressly be noted that the draw pin may also be replaced with a plate, which is contacted by the yarn.
The invention turns deliberately away from an "only" contactfree guidance of the yarn. In accordance with an embodiment wherein the surface temperature of the second heat treatment is above the melt point of the yarn, the heat transfer occurs in the first stage by contact, which is made such as to result in only small frictional forces on the yarn. In particular, the first stage of the heat treatment may occur with the use of a heated godet, which withdraws the yarn from the spinneret. This godet is arranged at a location, in which the freshly spun yarn is again substantially cooled (about 40° C.). This godet may be heated to a temperature from 70 to 120° C. A subsequent draw roll withdraws the yarn from the first godet under such a yarn tension, that the yield point forms in the yarn directly upon its leaving the godet. Alternatively, a draw pin that is heated from the inside or a heated plate may be used in the place of the godet or withdrawal roll. The contact length on the draw pin may be so small that the developing frictional forces are just adequate for a plastic flow to occur for the first time on the draw pin and, accordingly, for the formation of a yield point. Thus, the draw pin acts as a brake surface, similar to that disclosed in DE 38 23 337. In the second stage, however, the yarn is advanced substantially without contact, i.e., it is guided very precisely at a close distance from a heating surface, which is heated to a temperature from 350 to 550° C. The spacing between the yarn and the heating surface ranges from 0.5 to 3.5 mm, so that the yarn is suddenly heated when entering into the heating zone.
The yarn is guided by yarn guides, which provide, on the one hand, a smooth run of the yarn and, on the other hand, a precise distance from the heating surface.
In a third stage, the yarn may then be heated in a different embodiment, likewise without contact and at a close distance from a further heating surface, which is heated to a temperature from 300 to 500° C.
In another embodiment, the drawing occurs between two godets, with the first godet being unheated, and with the first heat treatment occurring downstream of the first godet by means of a stationary draw pin which is partially looped or at least contacted by the yarn. This permits a very accurate adjustment of the draw ratio. Even at withdrawal speeds higher than 5,000 m/min, the draw pin ensures the formation of the yield point.
Another embodiment provides for the first heat treatment to occur downstream of the first godet by means of a heated plate, along which the yarn is guided without contact. This has the advantage that larger looping angles allow to produce higher yarn tensions.
A further embodiment provides for the drawing to start in the spin zone, with the withdrawal speed of the takeup being above 5,000 m/min. This has the advantage of utilizing the entrained spinning heat already in the first stage of the heat treatment. In this instance, it is not necessary to guide the yarn over a curved heating surface. As a result, withdrawal speeds can be reached in a range from 6,000 to 7,500 m/min.
The drawing may occur by means of a godet, which withdraws the freshly spun yarn directly from the spinneret at a speed greater than 3,500 m/min, and wherein the first heat treatment is provided by means of a stationary draw pin which is partially looped or at least contacted by the yarn. This results in a very simple process control.
The first heat treatment may be provided by a draw pin which is arranged within an elongate heating surface and adjacent the yarn inlet end thereof, and with the temperature of the heating surface being greater than the melt point of the yarn. This provides the advantage that the yarn forms, under little draw tension, a very precisely localized yield point, and undergoes a preferred structural change already in the first drawing stage as a result of its sudden heating.
The method may be applied to all commonly used polymer types. For the physical properties of yarns, it may be advantageous that same are spun from a formulation of different polymers. For example, it is known that the addition of up to 5% PBT (polybutylene terephthalate) to PET improves the spinnability and the elastic properties of the fibers.
Preferably, this method may be applied to process polypropylenes with a very narrow molecular weight distribution in a range smaller than 3, in particular types produced on the basis of metallocenes.
The apparatus is characterized in that a very short heater may be used, which has, however, due to its configuration, the advantage that it permits in the yarn a very purposeful temperature control, which is adapted to the speed of the yarn, and a very uniform heating over the length of the yarn. The sudden supply. of heat upon the start of the plastic flow prevents an interference with the crystalline structure and, thus, permits an optimal orientation of the yarn molecules.
The shocklike supply of heat in the first stage of the heating results in reaching the yield point suddenly, and it also reduces the length and force of contact.
A particular embodiment of the heater takes the form of an elongate, U-shaped body having a longitudinal heating groove, and guides for guiding the advancing yearn along the groove without contacting the groove walls. This provides the advantage that it is simple to operate, in particular that it facilitates the threading of the yarn. Likewise, it is easy to monitor.
The elongate heater as described above may comprise a plurality of body segments positioned in an end to end relationship. Also, the body segments may be positioned with respect to each other so as to define an obtuse angle when viewed in side elevation. This ensures a smooth yarn guidance and, further, permits a temperature control that may be adapted to particular requirements. As a result, strength, elongation, and shrinkage tendency of the yarn can largely be influenced and adjusted to desired values. Also, short guide elements may be distributed along the heated surface to establish the yarn path relative to the heated surface and to smoothen the yarn path.
In another specific embodiment, the heater of the first treatment may comprise a heated draw pin which is partially looped by the yarn, with the surface of the draw pin having a temperature above the melt point of the yarn, preferably greater than 150° C. above the melt point. Alternatively, the first heat treatment may be provided by a heated plate along which the yarn advances without contacting the same, and with the temperature of the plate being above the melt point of the yarn, by at least 150° C. These embodiments provide a simple configuration from the viewpoint of mechanical engineering. The looping of the yarn on the draw pin may be adjusted very simply by positioning the draw pin, so that with regard to the temperature of the draw pin, the yarn tension is increased so much that a yield point forms on the draw pin. This embodiment may also be operated without withdrawal roll, which is simple with respect to the machine construction, on the one hand, but also permits, on the other hand, to already utilize for the formation of the yield point the heat which is entrained in the yarn from the spin zone.
The draw zone may be arranged between a withdrawal godet and a downstream drawing godet. This permits very far reaching possibilities for adjusting the draw ratio and the resulting orientation and other properties of the yarn.
BRIEF DESCRIPTION OF THE DRAWINGS
Some of the objects and advantages of the present invention having been stated, others will appear as the description proceeds, when considered in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic view of a spin process and apparatus which embodies the present invention;
FIG. 2 illustrates a modification of the method and apparatus;
FIGS. 3a, 3b, and 3c are sectional side, sectional transverse, and front views, respectively, of a heater which may be used with the present invention;
FIG. 4 schematically illustrates a modification of the draw zone and its apparatus;
FIG. 5 schematically illustrates a further modification of the draw zone and apparatus; and
FIG. 6 illustrates an embodiment of the method and its apparatus of the present invention and which does not employ godets.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 illustrate a yarn spinning method and apparatus wherein a yarn 1 is spun from a thermoplastic material. The thermoplastic material is supplied through a feed hopper 2 to an extruder 3. The extruder 3 is driven by a motor 4, which is controlled by a motor control unit 49. In extruder 3, the thermoplastic material is melted. The work of deformation (shearing energy) which is applied by the extruder to the material assists in the melting process on the one hand. In addition, a heater 5, for example, in the form of a resistance heater, is provided, which is controlled by a heating control unit 50. Through a melt line 6, which accommodates a pressure sensor 7 for measuring the melt pressure for a pressure-speed control of the extruder, the melt reaches a gear pump 9, which is driven by a pump motor 44. The pump motor is controlled by a pump control unit 45 such as to permit a very fine adjustment of the pump speed. The pump 9 delivers the melt flow to a heated spin box 10 which mounts on its underside a spinneret 11. From spinneret 11, the melt emerges in the form of a web of fine filaments 12. The web of filaments 12 advances through a cooling shaft 14. In cooling shaft 14, an air flow 51 is directed transversely or radially toward the web of filaments 12 from a housing 15, thereby cooling the filaments.
At the end of cooling shaft 14, a spin finish applicator roll 13 or an applicator pin combines the web of filaments to form a yarn 1 and applies to the yarn a liquid spin finish.
Referring now only to the embodiment of FIG. 1, the yarn is withdrawn from cooling shaft 14 and from spinneret 11 by a godet 16. The yarn loops about godet 16 several times. To this end, a guide roll 17 which is axially inclined relative to godet 16 is used. The guide roll 17 is freely rotatable. Godet 16 is driven by a godet motor 18 and a frequency changer 23 at a preadjustable speed. This speed is by a multiple higher than the natural exit speed of filaments 12 from spinneret 11, and it is higher than the filament speed after solidification by the air flow.
Referring now only to the embodiment of FIG. 2, the yarn is withdrawn from cooling shaft 14 and spinneret 11 by a godet 54. The yarn loops about godet 54 several times. To this end, a guide roll 55 which is axially inclined relative to godet 54 is used. The guide roll 55 is freely rotatable. The godet 54 is driven by a motor at a preadjustable speed. This withdrawal speed is by a multiple higher than the natural exit speed of the filaments 12 from the spinneret. From godet 54, the yarn advances through a heater 20b to a further godet 16, also referred to as draw roll in the present embodiment. The draw roll 16 is driven at a higher speed than the aforesaid godet 54. As a result, the yarn is drawn between the two godets 54 and 16.
Referring now again to both embodiments, from draw roll 16 of FIG. 2 or draw roll 16 of FIG. 1, the yarn 1 advances to a so-called "apex yarn guide" 25 and thence into a traversing triangle 26. Not shown in the Figures is a yarn traversing mechanism 27, which may, for example, comprise counterrotating blades which reciprocate the yarn 1 over the length of a package 33. In so doing, the yarn loops, downstream of the traversing mechanism 27, about a contact roll 28. The roll 28 rests against the surface of a package 33, which is formed on a tube 35. The tube 35 is clamped on a winding spindle 34, which is driven by a spindle motor 36 and a spindle control unit 37 such that the surface speed of the package 33 remains constant. To this end, the speed of contact roll 28 which rotates freely about a shaft 29 is scanned as a controlled variable by means of a ferromagnetic insert 30 and a magnetic pulse generator 31. A comparator 46 may be provided for comparing the rotational speeds of the spindle 34 and shaft 29.
It should be remarked that the yarn traversing mechanism 27 may also be a standard cross-spiralled roll with a traversing yarn guide reciprocating in a groove over the width of the traverse.
In FIG. 1, the diameter or a value derived therefrom is continuously measured as parameter of the condition of the package 33. For measuring the diameter, the speed of spindle 34 and the speed of contact roll 28 resting against the surface of the package are measured. To this end, use is made of ferromagnetic inserts 30, 38 both in spindle 34 and in contact roll 28, as well as corresponding pulse generators 31, 39. Whereas the speed of the contact roll 28 is used simultaneously as a control variable for the adjustment of spindle motor 36 via spindle control unit 37, the speed of spindle 34, which is not described in more detail, is used to control the yarn traversing mechanism 27.
As shown in the embodiment of FIG. 1, draw pins 56 and heater 20b are arranged between cooling shaft 14 and godet 16. The last of draw pins 56 has a heated surface 32, so as to define a first heater 20a, and so that the heater 20b defines a second or downstream heater. Preferably, the draw pins are not rotatable and they are mounted stationarily. They are partially looped by the yarn. By the adjustment of the first draw pin perpendicularly to the yarn path, the looping angle and, thus, the contact length on the surfaces of each draw pin may be reduced or enlarged as desired. In an arrangement comprising three draw pins (FIG. 5), it is preferred to adjust the intermediate draw pin. In FIGS. 1, 4, and 5, the illustration of the offset is exaggerated. In reality, a small offset will suffice. At least one of the draw pins, as aforesaid, preferably the last one, is heated. The temperature, to which the yarn is heated, is higher than the glass transition temperature of the yarn, which is 55° C. and less than 120° C. for polyester.
At a surface temperature of the heating surface 32 of heated draw pin 56, which is above the melt point of the yarn material, withdrawal speeds higher than 5,000 m/min are reached. In this instance, the contact lengths on draw pins 56 are kept very short.
In the embodiment of FIG. 2, the heater 20b is positioned between withdrawal roll 54 and draw roll 16. In this embodiment, the surface 32 of withdrawal roll 54 is heated, so as to define a first heater 20a, and so that the yield point of the yarn forms directly downstream of or on the godet. For a further heat treatment, the yarn advances through the heater 20b, which may be described as a second heater.
FIG. 4 illustrates a modification of the embodiment of FIG. 2. In this embodiment, the withdrawal roll 54 is unheated. Instead, upstream of heater 20b, draw pins 56 are arranged, of which at least one has a heated surface 32, so as to define the first heater 20a. Otherwise, the configuration and temperature control of these draw pins corresponds to those of the draw pins, as have been described with reference to FIG. 1.
An advantageous further development of the arrangement of FIG. 4 is realized, when the draw pins 56 are arranged in the yarn inlet region of the second heater 20b. In this instance, the yield point of the yarn will form directly downstream of the last draw pin 56, so that drawing and setting occur in the directly following heat treatment.
FIG. 5 shows likewise a modification of the embodiment of FIG. 2. The withdrawal roll 54 is unheated. Upstream of heater 20b, unheated draw pins 56 are arranged. Opposite to the looping side of the intermediate draw pin is a heated plate 58, which defines the first heater 20a, so that both the yarn and, indirectly, the draw pins are heated.
In this embodiment, the method may be modified to the extent that the draw pins 56 are omitted. In this instance, the yarn advances barely contacting, or even without contacting the heated plate 58.
In the embodiments of FIGS. 4 and 5, each of which replaces the boxed-in portion in FIG. 2, the draw pins and the second heater 20b are arranged between the withdrawal roll 54 and the draw roll 16.
In the embodiment of FIG. 2, the withdrawal roll 54 is heated to a temperature from 70 to 120° C.
In both cases, the withdrawal roll 16 may also be heated to a temperature of about 150°±40° C., so as to achieve a shrinkage and heat setting of the yarn. However, this is not subject matter of the invention.
In the embodiment illustrated in FIG. 6, the yarn is withdrawn directly, without godets, at a speed greater than 5,000 m/min directly by the takeup unit, which as illustrated comprises a contact roll 28 and a package 33. A drawing starts initially in the spin zone. A first stage of the heat treatment is formed by entrained spinning heat, and the yarn need not be guided over a curved surface. Subsequently, the yarn advances through an eyelet or yarn guide 8 to a second stage of the heat treatment by means of heater 20b. The heat treatment occurs in that the yarn 1 is guided substantially over a heating surface 117a, 117b. The heating surface 117a, 117b has a surface temperature, which is above the melt point of the yarn material. After drawing, the yarn is wound directly onto the package 33. This modification allows withdrawal speeds in a range from 6,000 to 7,500 m/min to be reached.
The heater 20b may be constructed in two sections. Both sections have about the same length, namely from 300 to 500 mm, or they may be made deliberately shorter in the inlet region and longer in the following zones, so that the temperature in the inlet region can be exceeded considerably in comparison with the subsequent zones. The temperature is controlled such that in the inlet section, the surface temperature ranges from 450 to 550° C. and in the outlet section from 400 to 500° C. The yarn is guided at a small distance from the respective surface, for example a distance from about 0.5 to 3.5 mm.
The heater 20b, is more particularly described with reference to FIGS. 3a-3c. As shown, the heater 20b may consist of a plurality of, in the present embodiment two, body segments 114a and 114b. The two body segments are of a different length, but otherwise have an identical cross sectional configuration. Such a bipartite arrangement may serve the purpose of heating heater 20b in different axial segments to a different temperature, so as to treat the yarn 1 in a heat profile that meets with its properties. This means, that more than the two shown segments may be used. Of special importance is that the angle, which the two heating segments 114a, 114b form with each other, is identically adjusted in each processing station of a spin-draw machine, so that all processing stations produce yarns of the same quality. To mount the two heating segments 114a, 114b, a mounting rail 158 is used, which has the length of both heating segments. The mounting rail has a U-shaped cross section. The heating segments 114a, 114b are attached with spacers 160 to the bottom of the mounting rail. As a result of the dimensioning of the spacers and their position relative to the heating segments 114a, 114b, the inclination of the heating segments is established with respect to the straight mounting rail 158. In this arrangement, the two heating segments are oppositely inclined relative to the mounting rail and, moreover, they form an obtuse angle with respect to each other. On the one hand, the mounting rail 158 is used to accurately mount the two heating segments. However, since the mounting rail 158 has a U-shaped profile, it also surrounds the two heating segments. Therefore, the mounting rail 158 is also used to equalize the temperature over the length and width of the heating segments.
Each of the heating segments 114a, 114b is provided with two longitudinal grooves 112, and each heating segment includes a substantially flat base portion 116 which defines an upper heating surface 117. Outer side walls 118, 122 are thus defined which lie on the outside of the longitudinal grooves, and a central wall 120 is defined which lies between the longitudinal grooves.
Inserted in walls 118, 120, 122 are recesses or bores 128. The recesses 128 arranged in central wall 120 are offset by the spacing A from the recesses 128 in side walls 118 and 122. The recesses have a circular-cylindrical shape. Each recess 128 in the outer walls 118, 122 is intersected by a longitudinal groove 112, and each recess 128 in the central wall 120 intersects both grooves 112. Thus the walls 118, 120, 122 and the yarn guides 132 form therebetween slots 133.
Each recess 128 accommodates a yarn guide 132, the cross sectional shape of which corresponds to the cross section of the recess both in size and shape. A portion of each yarn guide 132 extends in the groove 112 such that, on opposite sides of grooves 112, successively arranged yarn guides 132 extend by a certain dimension, beyond the walls 118, 120, 122.
Caps 152 are positioned on top of the walls 118,120,122. The side walls 118 and 122 are provided on their upper edge portions with a head 156, which is wider than the respective wall, note FIG. 3b. The central wall 120 is provided on its upper edge portion with retaining grooves 154. In cross sectional view, the caps 152 have a C-shaped profile, so that in the case of central wall 120 they extend into retaining grooves 154, or in the case of side walls 118, 122 they embrace wall head 156.
The yarn guides 132 are conically beveled on their ends facing away from the base portion 116, as is indicated at 134. As a result, the yarn guides 132 successively arranged in opposite walls 118 and 120, or 122 and 120 form a V-shape 136, as seen in FIG. 3b. The yarn 1 resting against the contact surfaces of the yarn guides then forms a zigzagged yarn path of travel along the groove.
It is possible to provide bar-shaped spacers 140, which bridge over the bottom of an axial groove 112, i.e., the heating surface 117a, 117b, and define the yarn path at a precise distance from the groove bottom. Alternatively or additionally, some or all yarn guides 132 may be provided with a peripheral guide edge, for example, a peripheral groove 142 (FIG. 3a), whose height from the bottom is adapted to the height of the yarn path that is predetermined by guide elements 140. In this manner, the yarn which is guided in the groove is guided in addition by the side edges of the groove. The peripheral grooves have the same depth over the circumference and, thus, are made concentric with yarn guides 132. However, it is also possible to provide the peripheral groove with a depth changing over the course of the circumference, for example, in that the groove bottom is cut in circular-cylindrical shape, but off-center relative to the yarn guides 132. This makes it possible to finely adjust the contact between yarn 1 and yarn guides 132 and define a zigzag yarn path by rotating the yarn guides. To this end, the yarn guides 132 may be rotated jointly and to a same extent, for example, by means of a linkage (not shown), to which they are connected.
The heater is preferably accommodated in an insulated box (not shown), in which it is embedded in a heat-insulating material, for example fiber glass. The insulated box may be provided with a flap, which permits the box to be opened for accessing the heater and threading the yarn. Furthermore, the insulated box with its portions overlying the heater serves to axially position the yarn guides 132 in the rail 114. To this end, the insulated box is provided with slots, which align with the central plane and bevels 134 of the yarn guides 132 and permit a yarn 1 to be inserted for its treatment between yarn guides 132. On their side walls, the slots are provided with wear-resistant insulated sheets. Likewise accommodated, if need be, in the insulated box are the necessary electrical contacts for heating elements 124, 126.
The surfaces of the yarn guides which contact the yarn have a relatively large diameter. In contrast thereto, the zigzag line, along which the yarn advances as a result of an overlap U of successive yarn guides, has a relatively small amplitude with a relatively large spacing A between two adjacent yarn guides. This allows the looping angle, at which the yarn loops about the yarn guides or the contact surfaces formed thereon to be small, when added up.
In the illustrated embodiment, the heater 20b includes two parallel grooves 112 of like construction, and the heater has two channels below the grooves which accommodate the heating elements 124 and 126. The heating elements are clamped in place by a mounting plate 159 which extends over the entire length of the heater. To this end, the mounting plate is provided with grooves which enclose the heating elements 124, 126. By disengaging the mounting plate 159, the heating elements 124, 126 can easily be replaced.
The spacing between the yarn and heating surface 117 is very small and ranges from 0.5 to 5 mm. Preferably the upper value is no more than 3.5 mm, so as to realize a good heat transfer and an accurate, troublefree temperature control.
As a result of heating the heater 20b to a correspondingly high temperature of more than 350° C., a sudden heating occurs. At least in part, the yarn guides 132 may also be omitted or removed, should they exert a negative influence. However, the yarn guides contribute to a smoothing of the yarn path and heating the yarn by contact and, in addition, they exert only little friction on the yarn due to the small looping. However, their essence is the contactfree guidance in close vicinity to the heating surface which is heated to a high temperature.
In the drawings and the specification, there has been set forth preferred embodiments of the invention, and, although specific terms are employed, the terms are used in a generic and descriptive sense only and not for the purpose of limitation, the scope of the invention being set forth in the following claims. | An apparatus for spinning, drawing, and winding a synthetic filament yarn, wherein the yarn is subjected during its drawing in a draw zone to a multi-stage heat treatment by heated surfaces. In the first heat treatment, the yarn is heated to the range of the glass transition temperature of the yarn material, and the yarn is guided over the heating surface while partially looping thereabout. The second stage of the heat treatment is formed by an elongate heating surface, and at least one of the heating surfaces is heated to a surface temperature above the melt point of the yarn material. In the draw zone, the yarn is subjected to a tension, which is necessary for a plastic deformation in or directly downstream of the first stage of the heat treatment. The process performed by the apparatus causes the yarn to be drawn and set. | 3 |
OBJECT OF THE INVENTION
[0001] The present invention, tooth and adaptor for dredging machines, relates to a tooth or wear member which, attached to an adaptor, creates an stabilized assembly against all the forces exerted on the point of the tooth. The purpose of the tooth and the adaptor of the present invention is to dredge the seabed and deepen and clean the beds of ports, rivers, channels, etc., removing therefrom sludge, stones, sand, etc., the adaptors being attached to the arms of the cutter head of the dredging machine.
[0002] The dredging machine, or dredger, allows excavating, transporting and depositing material that is located under the water, using cutting members, teeth or adaptors on different kinds of terrains.
[0003] The tooth and adaptor object of the present invention are preferably intended to be used in dredging machines having a suctioning cutter head of the type which while at the same time it excavates the terrain under the water, the loosened material is suctioned by a pump and transported somewhere else through a pipe.
STATE OF THE ART
[0004] Systems of tooth and adaptor are known in the state of the art for their application in dredging operations. The main objective of said operations is to remove material from marine or river beds, usually made using cutter suction dredgers that include cutter head on which various teeth are arranged via adaptors.
[0005] As stated, in order to dredge underwater soil, a cutter suction dredger is used. The cutter suction dredger is a stationary dredger equipped with a cutter head that excavates the soil and afterwards said soil is suctioned up by the dredge pump or pumps.
[0006] Such cutter suction dredger is anchored to the ground by means called spud poles, and through them, the strong reaction forces occurring during dredging are absorbed and transferred to the ground. The cutter head is mounted to the cutter suction dredger through a ladder. In the known suction dredger the ladder forms a more or less rigid connection between the cutter head and the cutter suction dredger. In order to dredge underwater soil, the cutter head with ladder and suction pipe is lowered under water in a usually slanting direction, until the cutter head touches the bottom, or until it reaches the maximum depth. The movement of the dredger round the spud pole is initiated by slacking the starboard anchor cable and pulling in the port side anchor cable or reverse, so that a more or less circular soil path is formed. These anchor cables are connected via sheaves close to the cutter head to winches (dredging side winches) on deck. The paying out winch ensures the correct tension in both cables, this being particularly important when dredging in hard rock.
[0007] The cutter head is rotated relatively slowly (common rotation speeds of 20 to 40 rpm), as a result of which soil pieces are beaten off by the dredging teeth at great force. By each time moving the suction dredger over a given distance and repeating the above described ladder movement, a complete soil area can be dredged.
[0008] The cutter suction dredger can tackle almost all types of soil, although of course this depends on the installed cutting power. For heavy cutter suction dredgers the limit will be rocks with a compression strength of around 80 MPa, if the rock is weathered and has many crocks, it is possible to go a little further than that.
[0009] The cutter head is provided with wear elements that penetrate and tear up the ground. These wear elements are teeth connected to adaptors fixed to the arm of the cutter head, the teeth connected to said adaptors in a detachable way.
[0010] The cutter head works in a rotational movement, so the teeth tear up the ground forming an arched path. Depending on the direction in which the tooth starts to penetrate the ground a different cut is obtained. When the tooth starts penetrating the surface area of the ground and tears up downwards of the ground till the rotation movement leaves the ground, an over-cutting is obtained. On the other hand, when the tooth starts to tear up from inside the ground and tears up upwards till the surface area of the ground, an under-cutting is obtained.
[0011] When the teeth tear up the ground in over-cutting and under-cutting, reaction forces appear on the point of the teeth. All reaction forces from the cutter head have to be transferred in a certain way to the surroundings, either by the side winch forces or the spud poles to the soil, or via the ladder wires and the pontoon to water. Besides that, these cutting forces determine the weight of the dredger, while the forces to move the dredger through the water can have influences on the design of the dredging parts.
[0012] Cutter heads have seldom a cylindrical shape but rather have profiles with parabolic shape. This profile is determined by a plane through the surface of revolution formed by the tooth points. The cutter head is composed by arms in which the teeth are attached. The teeth are normally positioned in such a way that the projection of it's center line is normal to the profile. An imaginary line from the center line of the cutter head to the point of the tooth is created, normal to said profile.
[0013] The active point of the tooth is provided with three surfaces, a working surface which is the surface that has direct contact with the ground, an opposite surface which is opposite to the working surface and a normal surface that separates the working surface and the opposite surface.
[0014] As such, three reaction forces appear on the point of the teeth
Normal force or radial force (F N ): in a same direction of the imaginary line between the center line of the cutter head and point of the tooth, applied on a normal surface of the tooth. Tangential force (F T ): perpendicular to the normal force and applied on the working surface of the tooth. This tangential force is in direction parallel to the ground. Lateral force: Mainly caused by the interaction of neighboring cuts.
[0018] During the overcutting, the ladder will tend to move upwards when the tooth impacts against the surface area of the ground when it starts to penetrate the surface area of the ground. These impacts are larger when the hardness of the soil and the layer thickness are also harder.
[0019] Water conditions also affect the dredging development and the dropping of the production ratio. With certain types of waves, the ship will start moving; therefore the cutter head will move up and down because of the vertical movement of the waves and this provokes undesired hits of the cutter head and above all the teeth over the ground, causing a cut that is either too deep or too shallow.
[0020] Furthermore, in hard soil the cutting force is a decisive factor, therefore a heavy load on the construction of the ladder and on the spud, in particular, is added to facilitate the dredge work.
[0021] When said undesired vertical movement of the ladder appears due to the overcutting, water conditions and an overweight of the cutter for hard soil, the cutter teeth are loaded over the opposite surface with a wrong direction causing an important damage to the teeth, to the adaptors and to the pin system. In certain conditions the dredging process has to be stopped. An unexpected inverse force (F I ) appears on the opposite surface of the cutter tooth.
[0022] When these unexpected inverse forces (F I ) appear during work, which are worst when working on hard soil, the tooth moves/rotates due to the effects of said forces on the point of the tooth and when the coupling is not correctly stabilized which makes unstable the coupling between the tooth and the adaptor, that causes the unbalanced movement between the contact surfaces of the tooth and the adaptor. This situation makes the stability of the system worse and in some occasions it can even cause the breakage of the pin. The fact that a system is not correctly stabilized makes that the efforts from the tooth to the adaptor, and therefore from the adaptor to the arm of the cutter head, are transmitted in an incorrect way. The efforts are always withstood by the contact surfaces between the tooth and the adaptor, but when the coupling is not stabilized and a secure and uniform contact between the surfaces is not achieved, the efforts are transmitted to the pin too. The consequence of this instability is that the movement between the tooth and the adaptor increases and accordingly the gap between them increases too. At the same time a non-desired wearing on the contact surfaces between the tooth and the adaptor also gets worse. This happens because the inverse forces are not compensated by the reactions between the contact surfaces of the tooth and the adaptor.
[0023] When the tooth tries to move in the direction of the inverse force there is no contact surface on the adaptor and the tooth to prevent said movement and therefore the efforts can get to the pin that is the one that supports the same. As the pin is not designed to support said efforts the same usually deforms or breaks. If the same deforms it will be difficult to extract the pin from its housing when the tooth has to be replaced, and if it breaks the tooth can fall and the adaptor is damaged due to impacts and wearing.
[0024] Therefore, it is important that the tooth and adaptor have contact surfaces that counteract all the forces that can be exerted on different places of the wear part of the tooth, so that all the possible contacts between the tooth and the adaptor are balanced.
[0025] In the state of the art there are different teeth for dredge working but none of them are really prepared to resist in an effective way the inverse forces exerted on the point of the tooth without the breakage of the pin, tooth or even the adaptor.
[0026] The closest prior art is EP06807940 that describes a tooth with a rear coupling part or nose for engaging to an adaptor with the assistance of a transversal pin that goes through the nose and the adaptor. The contact surfaces between the tooth and the adaptor contribute to the stabilization during work against the normal and tangential forces, but not against inverse forces, that as previously explained cause the movement of the tooth inside the cavity of the adaptor due to the lack of contact surfaces against said movements. These movements transfer the efforts to the pin, that suddenly changes it function from a retaining function to a resistance function. As the pin is not designed to resist excessive forces, the same deforms or even breaks depending of the force suffered and this turns out in the problems mentioned above, and mainly losing the tooth under the water and preventing the extraction of the pin due to its deformation in a hammerless way. In FIG. 18 , the reaction forces when a tooth according to the cited prior art document is subjected to an inverse force are shown. In the figure it can be seen a reaction force at the free end of the upper surface of the nose and another reaction in the lower side of the inclined surface. The horizontal (Rx) reaction on the lower side of the inclined surface of the collar, which is not compensated by other reaction, tends the tooth to go out (to be ejected) of the system and therefore making the contact area and, above all, the pin suffer excessive forces as previously described. The forces (F I ) applied on the point of the tooth make the tooth rotate in respect of the adaptor, as the upper surface of the free end of the nose and the lower surface of the inclined surface of the collar of the tooth contact with the adaptor, causing the mentions reactions. As stated the reaction Rx is the one that tends to eject the tooth from the coupling, and is the one that the present invention counteracts.
[0027] U.S. Pat. No. 7,694,443B2 and WO2011149344 describe teeth for dredge working where the tooth is fastened to the adaptor through a retention system that does not go through the tooth and the adaptor but retains the tooth through the end of the nose by pulling it against the adaptor using elastic means. This solution reduces the gaps between the tooth and the adaptor. These systems comprise at the free end of the nose of the tooth a hook that is used to exert a traction force on the tooth. This hook makes this part of the tooth the weakest one and therefore is subjected to breakage because there are traction reactions confronted between the tooth and the adaptor. Said elastic means in the retention system to maintain the tooth and the adaptor in contact due to the traction force exerted do not prevent the appearance sometimes of gaps between the contact surfaces. When these gaps appear the system is not well stabilized and the tooth and adaptor can move one in respect of the other because they do not have good contacts between both elements. The invention object of the present application prevent the formation of gaps due to the stabilization between the contact surfaces.
[0028] Spanish patent document number ES-2077412-A describes an asymmetric tooth and adaptor assembly made up of three parts requiring the use of two fastening systems. The fact that it has three parts complicates the entire system because it requires a larger number of spare parts and three fastening systems, one of which requires the use of a hammer whereas the other two fastening systems are formed by welding, making the tasks for replacing them long and complex. Further, the pin is placed on a side of the nose of the tooth, on a slot, making the system asymmetric and therefore providing a system less stable against the forces exerted on the tip of the tooth, specifically only stabilized on one side. The grooves in the nose of the tooth makes the system less resistant too because the section of the nose is smaller where the grooves are placed.
[0029] The present invention solves the drawbacks of the solutions existing in the state of the art for dredging machines, and among others:
Great stability of the coupling between the adaptor and the tooth to prevent the action of the inverse forces, contributing to an optimal distribution of the reaction forces along the contact surfaces between the tooth and the adaptor to prevent the tooth from moving on the adaptor. Minimize or remove reaction forces on the assembly that tend to extract the tooth from the adaptor Protect the pin connecting the adaptor and the tooth, from deformation and breakage due to said stabilization. Reduce the material needed for the pin, as the efforts resisted by the pin are diminished. This reduction of material turns in a reduction of the diameter of the pin and therefore in a reduction of the diameter in the holes of the housing for said pin in the tooth and the adaptor. The coupling parts in the tooth and the adaptor of the present solution are more robust than the state of the art ones.
DESCRIPTION OF THE INVENTION
[0034] The invention describes a tooth with a front wear part and a symmetric rear coupling part, respect a vertical plane ZY, intended for being housed within a cavity arranged in the body of an adaptor, object too of the present invention, and an assembly formed by both for dredging machines, both parts being attached to one another by means of a preferably hammerless, preferably vertical-type locking system. The adaptor is attached to the arm of the cutter head of the dredging machine at the end opposite to the cavity by means of a coupling adapted for such purpose.
[0035] According to the above, the vertical plane ZY is defined by the z axis and the y axis. The z axis extends longitudinally along the body of the rear coupling part of the tooth and the cavity of the adaptor. The y axis is orthogonal to axis z and extends vertically. The x axis is orthogonal to the previous defined axis z and y.
[0036] The main purpose of the present invention is to support or resist the previously described inverse forces that appear on the point of the teeth during dredging works at the same that the other reaction forces due to the normal and tangential forces, as well as the lateral or side forces, on the tooth are minimized.
[0037] A first object of the invention is to provide a tooth which enables coupling to the cutter head of a cutter suction dredger, via an adaptor, which presents a complete stabilized coupling, including the stabilization against inverse forces. Said first object is achieved by a tooth according to claim 1 .
[0038] A second object of the invention is to provide an adaptor which enables coupling of a tooth to a cutter head of a cutter suction dredger, which presents a complete stabilized coupling, including the stabilization against inverse forces. Said second object is achieved by an adaptor according to claim 6 .
[0039] A third object of the invention is a coupling system or a tooth and adaptor assembly, according to claim 10 , made up by a tooth and adaptor according to the previous claims.
[0040] In a first aspect, the invention relates to a tooth for coupling to the cutter head of a cutter suction dredger, via an adaptor, the tooth having a front wear part and a symmetric rear coupling part, respect a vertical plane ZY. The rear coupling part has a main body with a rear free end and a forward end that is bounded to the front wear part, having the main body a first upper surface and a first lower surface joined by two side surfaces. Adjacent to the rear free end of the first upper surface there is an upper segment that extends a certain distance from said rear free end towards the forwards end. A lower segment, approximately parallel to the upper segment, is provided too on the first lower surface.
[0041] Each side surface of the main body defines a side projection with a second upper surface that is parallel to a second lower surface, being said second upper surface approximately parallel to the lower segment on the first lower surface of the main body and the second lower surface approximately parallel to the upper segment on the first upper surface. The parallelism between said surfaces is important to counteract the forces exerted on the tip of the wear part of the tooth. The wider the projections are the better for counterbalancing the reactions on the contact surfaces, but this dimension depends on the geometry of the coupling between the tooth and the adaptor. The distance between the second upper surface and the second lower surface of the projections is smaller than the distance between the upper segment on the first upper surface and the lower segment on the first lower surface of the main body. The second upper surface of the projection is preferably an extension of the first upper surface, forming both surfaces one contact surface at the same level. Anyway, the first upper surface and the second upper surface could conform two different contact surfaces, therefore at different levels.
[0042] The tooth can include a centered upper rib on the first upper surface that increases the section of the rear coupling part. Said rib extends between the upper segment of the first upper surface and ends at the front wear part. Specifically, the rib starts where the upper segment ends in the direction of the forward end of the nose, and ends where the rear coupling part binds the front wear part.
[0043] The tooth can include too a stopper placed between the front wear part and the rear coupling part or nose, determining the place where both parts bind. Said stopper surrounds as a collar, perimeter projection or flange the first main body and comprises two V-shaped sides, being the distance between said two V-shaped sides larger than the distance between the side projections. The purpose of said stopper is:
Protecting the adaptor from wear through the deflectors in the upper and lower areas and which have been designed to redirect the flow of loosened material, preventing such material from friction or hitting against the adaptor and therefore preventing the wear thereof, and Making contact with the adaptor after prolonged wear, being thicker to resist the larger stresses to which it is subjected when contact with the adaptor is made, determining a further contact area between the tooth and the adaptor.
[0046] Said stopper can have variable thickness along its length depending on the stresses to which it is subjected during the work of the coupling. Specifically, said stopper has the thickest areas in its upper and lower area. The upper and lower second surfaces of the projections of the coupling part of the tooth extend until they meet the V-shaped sides of the stopper, defining said union between said second surfaces and the V-shaped sides an increase of the upper rib area, Further, said union is made through curved surfaces to reinforce the union between the different surfaces.
[0047] In a second aspect, the invention relates to an adaptor for coupling or attaching a tooth to the arm of a cutter head, said adaptor having a rear coupling end to attach the adaptor to the arm of the cutter head and a symmetric front coupling end, respect a vertical plane ZY, to couple to the tooth. This front coupling has a main cavity with a bottom end and an open end, said bottom end being bounded to the rear coupling end, and having the cavity a first upper surface and a first lower surface joined by two side surfaces that determine two side walls. The geometry of the cavity of the adaptor is complementary to the geometry of the nose of the tooth to allow the coupling between both.
[0048] Each side surface or wall of the main cavity has a side groove with a second upper surface approximately parallel to a second lower surface, being said second upper surface approximately parallel to a lower segment, adjacent to the bottom end on the first lower surface of the main cavity and the second lower surface parallel to an upper segment adjacent to the bottom end on the first upper surface. The upper segment is part of the first upper surface of the cavity and the lower segment is part of the first lower surface of said cavity. The approximate parallelism between said surfaces is important for the reaction forces that appear of the same to counteract the forces exerted on the tip of the wear part of the tooth. Said grooves are preferably continuous, therefore without interruptions along its surfaces, to achieve a uniform distribution of said reaction forces along the second surfaces.
[0049] The distance between the second upper surface and the second lower surface of the grooves is smaller than the distance between the segments of first upper surface and the first lower surface of the cavity. The second upper surface of the groove is preferable at the same level of the first upper surface, but it could be too on a different level.
[0050] The two side walls of the cavity, and specifically the free end of said side walls may have, in conjunction with the shape of the tooth, a V-shape.
[0051] According to the above, the tooth defines a front wear part and a rear coupling part, or nose, intended for being housed within a cavity arranged in an adaptor. Both the tooth and adaptor, when coupled, form an assembly or coupling system for dredging machines, both members being attached to one another by means of a preferably hammerless, vertical-type retaining system. The adaptor is attached to the arm of the cutter head of the cutting suction dredger at the end opposite to the cavity by means of a coupling adapted for such purpose.
[0052] Therefore, and as previously stated, the main object of the present invention is a tooth, an adaptor and the assembly formed by both, preferably applied to dredging machinery, that due to an increased and optimized stability of the contact surfaces between the tooth and the adaptor it allows that the forces exerted on the point of the tooth, independently of its direction, are transferred to the adaptor and at the same time to the arm of the cutter head. Therefore, the efforts are moved away from the contact surfaces of the assembly, existing between the tooth and the adaptor, to liberate the same from said efforts and to prevent, as much as possible, the breakage and loosening of any of the parts.
[0053] This object of the invention is achieved due to a particular construction of the contact surfaces between both members, that resist all the forces that appear on the point or tip of the tooth, and among all the forces, it is stabilized against the inverse forces previously described.
[0054] Said stability is achieved due to the configuration of the contact surfaces, which allow a distribution of stresses that favors the resistance and reduction of the stresses to which the retaining system and the tooth is subjected. In order to improve the stability, the rear coupling part of the tooth and the front coupling end of the adaptor are symmetric to achieve a balanced distribution of the efforts.
[0055] The cutting tooth and the adaptor objects of the present invention have contact surfaces and constructive features that allow the coupling between both members to increase its performance, particularly the efficiency of each tooth, thus improving the efficiency of the dredging machine.
[0056] An assembly that is well stabilized prevents an excessive wear of the contact surfaces between the tooth and the adaptor, and therefore prevents too that the gaps between both members increase during the use of the assembly.
[0057] The tooth is made up of two different parts, a front wear part, which is the part acting on the ground and is subjected to erosion due to the terrain, and a rear coupling part or nose, which is the part that is inserted in a cavity arranged for such purpose in the adaptor, and subjected to the reactions and stresses generated by the work of the tooth on the terrain. Said rear coupling part or nose is formed by a first main body with one free end and a forward end, opposite to the free end and bounded to the front wear part. The main body has two side surfaces having each of the surfaces a side projection which has the function of resisting the inverse forces.
[0058] The adaptor is also made up of two parts, a rear coupling end to attach the adaptor to the machine, and provided with a configuration that can vary depending on the type of machinery to which it is connected, to an arm of a cutter head of a dredging machine, whereas at the opposite end or front coupling end has a cavity intended to receive the rear coupling part or nose of the tooth. The inner configuration of the surfaces of the cavity of the adaptor for receiving the tooth are complementary to that of the nose of the tooth, comprising too each side surface of the cavity a side groove for the side projection of the tooth, thus assuring a perfect coupling between both members. For the coupling between the tooth and the adaptor, both parts preferably have a hole or through borehole from the upper part to the lower part of the adaptor, traversing the nose of the tooth.
[0059] A pin preferably with surfaces of revolution and with a preferably hammerless retaining system (which does not require striking with a hammer or mallet for being inserted or removed) is used.
[0060] The assembly of the rear coupling part or nose of the tooth in the cavity of the adaptor is possible due to the conjunction of the planes defining the described contact surfaces. A resisting or crushing effect between the tooth and the adaptor is furthermore achieved by means of said contact surfaces when the forces are applied to the wear tip of the tooth in a working situation of a tooth in a cutter head of a cutter suction dredger.
[0061] Due to this stabilized contact between the surfaces of the tooth and the adaptor, the pin is subjected to fewer stresses than in conventional interlocking systems since the tooth-adaptor system absorbs the great stresses when it is subjected to unexpected direction forces on the opposite surfaces, releasing stresses into the retaining system and the tooth/adapter contact surfaces, and therefore allowing designing pins of the retaining system with a smaller size and section since they are subjected to fewer stresses. The fact of reducing the size of the pin, and specifically the diameter, allows the design of a tooth and adaptor with smaller holes (smaller diameter) to access the housing of the pin. Therefore the nose of the tooth and the adaptor can be more robust.
[0062] According to the previous description, it is important to emphasize that the first and second upper and lower surfaces, on the tooth and on the adaptor, are stabilization planes that represent contact surfaces. Said stabilization planes serve to stabilize the tearing out forces that are produced at the point of the tooth, specifically the normal, tangential and inverse forces. The purpose of said surfaces is to nullify the reactions that tend to separate the tooth from the adaptor. It is necessary to nullify the horizontal reactions of the inverse forces applied on the contact surfaces between the tooth and the adaptor and that tend to extract the tooth from the adaptor. To prevent said extraction reactions, the reactions forces on the contact surfaces must have the same direction to the force, and to achieve this objective the approximately parallel first and second upper and lower surfaces are provided.
DETAILED DESCRIPTION OF THE DRAWINGS
[0063] To complement the description being made and for the purpose of aiding to better understand the features of the invention, according to a preferred practical embodiment thereof, a set of drawings is attached as an integral part of said description which show the following with an illustrative and non-limiting character:
[0064] FIG. 1 shows a perspective view of a tooth and an adaptor prior to their coupling.
[0065] FIG. 2 shows a side view of a tooth and an adaptor prior to their coupling.
[0066] FIG. 3 shows a perspective view of a tooth.
[0067] FIG. 4 shows a plan view of a tooth.
[0068] FIG. 5 shows a side view of a tooth.
[0069] FIG. 6 shows a front view of a tooth.
[0070] FIG. 7 shows another side view of a tooth.
[0071] FIG. 8 a shows a section, according to A-A, of the tooth of FIG. 7 .
[0072] FIG. 8 b shows a section, according to B-B, of the tooth of FIG. 7 .
[0073] FIG. 8 c shows a section, according to C-C, of the tooth of FIG. 7 .
[0074] FIG. 9 shows a perspective view of an adaptor.
[0075] FIG. 10 shows a plan view of an adaptor.
[0076] FIG. 11 shows a section, according to B-B of the adaptor of FIG. 10 .
[0077] FIG. 12 shows a side view of a tooth coupled to and adaptor.
[0078] FIG. 13 a shows a section, according to A-A, of the assembly of FIG. 12 .
[0079] FIG. 13 b shows a section, according to B-B, of the assembly of FIG. 12 .
[0080] FIG. 13 c shows a section, according to C-C, of the assembly of FIG. 12 .
[0081] FIG. 14 shows a plan view of a tooth coupled to an adaptor.
[0082] FIG. 15 shows a section, according to A-A, of the assembly of FIG. 14 .
[0083] FIG. 16 shows a section, according to B-B, of the assembly of FIG. 14 .
[0084] FIG. 17 shows a tooth coupled to an adaptor showing the forces (normal, FN, and positive tangential, FT) to which the assembly might be subjected during the work of the tooth in a determined cutter turn direction.
[0085] FIG. 18 shows a prior art tooth subjected to a negative tangential force (-FT) and the reactions on the tooth to said force. The reactions on the tooth to a positive tangential force (FT) are also indicated.
[0086] FIG. 19 shows a tooth subjected to a negative tangential force (-FT) and the reactions on the tooth to said force. The reactions on the tooth to a positive tangential force (FT) are also indicated.
DESCRIPTION OF A PREFERRED EMBODIMENT
[0087] As observed in FIGS. 1 and 2 , the objects of the present application, tooth and adaptor for dredging, is formed by an interchangeable tooth 10 , an adaptor 20 coupled to an arm of a cutter head (not shown) of a dredging machine, and a retaining member 30 responsible for assuring the connection between the tooth and the adaptor. Said retaining member or pin 30 enters the adaptor 20 through a hole 23 and enters the tooth through a hole 13 . The pin 30 goes through the tooth 10 and the adaptor 20 and is placed in a housing.
[0088] As can be observed in FIGS. 3 to 8 , the tooth 10 comprises a front wear part 11 or tip of the tooth responsible for the task of tearing out the terrain, in contact with the ground and stones, and a rear coupling part or nose 12 intended for being housed in a cavity 29 arranged in an adaptor 20 .
[0089] The rear coupling part 12 of the tooth 10 comprises a rear free end 16 and a forward end 19 , being this forward end 19 bounded to the front wear part 11 of the tooth 10 . The rear coupling part 12 has a first upper surface 123 , a first lower surface 122 and two side surfaces 121 joining both upper 123 and lower 122 surfaces. Said first upper surface 123 and said first lower surface 122 comprise each at least a segment 1230 , 1220 on its surface 123 , 122 where both segments 1230 , 1220 are approximately parallel between them. Said approximately parallel segments 1230 , 1220 , an upper segment 1230 on the first upper surface 123 and a lower segment 1220 on the first lower surface 122 , are preferably placed adjacent to the free end 16 of the rear coupling part 12 .
[0090] The nose or rear coupling part 12 of the tooth 10 is formed by a main body and an upper rib 15 centered on the upper surface 123 of said main body, increasing the section of the rear coupling part 12 where the hole 13 for the pin 30 goes through the nose 12 , and being the part of the tooth that more efforts has to resist. Said rib 15 extends between a point from the upper surface 123 of the main body of the rear coupling part 12 and the place where said part 12 binds the front wear part 11 . The separation between the front wear part 11 and the rear coupling part 12 is determined by two inclined planes U, D, forming an angle smaller than 90° between both and therefore determining a V shape, where the corner of the V is placed towards the tip front wear part 11 of the tooth 10 , on the opposite side of the free end 16 of the rear coupling part or nose 12 .
[0091] According to the previous definition of the axis x, y and z, it should be mentioned that inclined planes U and D cross themselves in axis x.
[0092] As previously explained, the upper rib 15 of the nose 12 of the tooth 10 has a shape that increases the section of the nose 12 towards the forward end 19 , having the upper rib 15 a triangular or trapezoidal longitudinal section, preferably. The rib 15 will not extend along the whole distance of the nose 12 of the tooth 10 , it will be shorter. The rib 15 can be narrower, smaller width, or have the same width, than the first upper surface 123 of the first main body of the nose 12 and it is centered with respect to said main body 12 . The height of said rib 15 is nil in an area close to the free end 16 of the nose 12 , preferably when the upper segment 1230 adjacent to the free end starts, and its height gradually increases until it reaches the wear part of the tooth 11 .
[0093] On both side surfaces 121 of the main body 12 , continuous side projections 14 are placed. Said projections 14 have a second upper surface 141 and a second lower surface 142 that are approximately parallel between them. The purpose of these projections 14 is help to optimize the complete stabilization of the coupling between the tooth 10 when coupled to an adaptor 20 when the same is subjected to Inverse forces. These projections 14 have its second upper surfaces 141 parallel to the lower segment 1220 on the first lower surface 122 of the main body 12 approximately and its second lower surfaces 142 approximately parallel to the upper segment on the first upper surface 1230 of the main body 12 . The thickness or distance between the second upper 141 and lower 142 surfaces of the projections 14 is smaller than the distance between the upper segment 1230 of the first upper surface 123 of the main body 12 and the lower segment 1220 of the first lower surface 122 of the main body 12 .
[0094] The second upper surfaces 141 of the projections 14 are preferably placed as an extension of the first upper surface 123 of the main body 12 , meaning that the second upper surface 141 of the projection 14 and the first upper surface 123 of the main body 12 are placed at the same level. Anyway, instead of coinciding the upper surfaces 141 of the projections 14 with the upper surfaces 123 of the main body 12 , it would be possible that the second lower surfaces 142 do coincide with the lower surface 122 of the main body 12 , or even that none of the upper nor lower surfaces coincide, being in this last case the side projections 14 placed between the first upper 123 and lower 122 surfaces of the main body 12 .
[0095] In the present description, when the term approximately parallel is used, it should be understood that the lines, planes or surfaces referred, could not be exactly parallel but a difference between 0° and 8° could exist between them. This difference will mainly be due to construction or fabrication restrictions that prevent the exact parallelism between the lines, planes or surfaces.
[0096] The tooth preferably comprises a stopper, with the shape of a collar, flange or perimeter projection, located on the perimeter of the tooth 10 where the front wear part 11 and the rear coupling part 12 bind. The stopper has two V-shaped sides on both sides of the tooth 10 , each with a superior part 17 and a lower part 18 , that coincide with the inclination of the previously mentioned planes U and D. The width between the V-shaped sides 17 , 18 of the stopper is preferably larger than the distance between the sides of the projections 14 and the height or distance between the upper and lower sides of said stopper coincides with the maximum distance between the upper surface of the upper rib 15 on the main body 12 and the lower surface 122 of the main body 12 . The thickness or width of said collar varies depending on the area of the tooth it surrounds and depending on the stresses to which said area is subjected.
[0097] FIG. 8 a shows a section of the tooth 10 at the segment ( 1220 o 1230 ) of the nose 12 , FIG. 8 b shows a section of the tooth 10 at the hole 13 for the pin 30 , and FIG. 8 c shows a section of the tooth 10 showing the side projections 14 on the side surfaces 121 of the nose 12 .
[0098] The adaptor 20 , shown in FIGS. 9 to 11 is formed by a body having a rear coupling 200 at one end to be attached to an arm of the cutter head of a dredging machine and at the opposite end it has an open end 210 with a cavity 29 for receiving the rear coupling part or nose 12 of a tooth 10 , which is inserted in said cavity 29 . The inner surfaces, of said cavity 29 of the adaptor 20 are complementary to the surfaces of the rear coupling part or nose 12 of the tooth 10 . In other words, said cavity 29 is formed by an open end 210 , a bottom end 26 opposite to the previous one and bounded to the rear coupling end 200 , a first lower surface 222 , a first upper surface 223 , and two side surfaces 221 joining both upper 223 and lower 222 surfaces. The shape of said open end 210 of the cavity 29 is defined by the shape of the two side surfaces 221 belonging to the lateral or side walls of the adaptor 20 , which have an V shape with a superior part 27 and a lower part 28 . Said V shape coincide with the two inclined planes U and D.
[0099] As previously described, the inner surfaces of the cavity 29 are complementary to the surfaces of the rear coupling part or nose 12 of the tooth 10 .
[0100] Each of the side surfaces 221 of the cavity 29 comprises a groove 24 that extends from the open end 210 of the cavity 29 to nearly the first segment 2220 , 2230 of the cavity 29 , being the second upper surface 242 of the groove 24 parallel to the first segment 2220 of the first lower surface 222 of the cavity 29 and the second lower surface 241 of the groove 24 parallel to the first segment 2230 of the first upper surface 223 of the cavity 29 . The distance between the second upper 242 and lower 241 surfaces of the grooves 24 is smaller than the distance between the first upper 2230 and lower 2220 segments of the cavity 29 . The second upper surface 242 of the groove 24 is preferably an extension of the first upper surface 223 of the cavity 29 . Anyway the grooves 24 could be placed at any level of the side surfaces 221 .
As shown in FIGS. 12 to 16 , the tooth 10 and adaptor 20 are coupled together by inserting the rear coupling part or nose 12 of the tooth 10 into the cavity 29 of the adaptor 20 , the different complementary surfaces of the nose 12 and of the cavity 29 coming into contact with one another.
[0102] In FIGS. 13 a to 13 c , the matching of the different contact surfaces along the rear coupling part or nose 12 of the tooth 10 and the cavity 29 of the adaptor 20 can be seen. FIG. 13 a shows a section where it can be seen the coupling between the projections 14 , with its upper 141 and lower 142 surfaces, and the grooves 24 , with its upper 242 and lower 241 surfaces.
[0103] FIG. 13 b shows a section of the assembly where the pin goes through both members.
[0104] FIG. 13 c shows the section near to the free end 16 of the nose 12 , where the first segment 1230 , 1220 of the first upper 123 and lower 122 surfaces of the nose 12 of the tooth 10 are parallel with the first segment 2230 , 2220 of the first upper 223 and lower 222 surfaces of the cavity 29 of the adaptor 20 . The side surfaces 121 of the nose 12 are parallel to the side surfaces 221 of the cavity 29 .
[0105] FIGS. 15 and 16 show different longitudinal sections of the coupling between a tooth 10 and an adaptor 20 according to the present invention. In particular it can be seen the different contact surfaces between both members and in FIG. 16 it can be seen that the second upper surface 141 of the projection 14 is at the same level of the first segment 1230 of the first upper surface 123 of the nose 12 of the tooth. The same happens with the complementary surfaces of the groove and the segment 2230 of the upper surface 223 of the cavity 29 .
[0106] Once the adaptor 20 has been attached through its rear coupling end 200 in the arm of the cutter head of the suction cutting dredger, the tooth 10 is coupled to the adaptor using for that purpose a preferably hammerless retaining member 30 , i.e. a member that does not require the action of a mallet or hammer for removing it from or inserting it in the housings intended for such purpose in the tooth and in the adaptor. The retaining system is preferably vertical, being inserted and removed through the upper part of the tooth and of the adaptor, going through the rear coupling part or nose 12 of the tooth 10 and the adaptor 20 through respective through holes 13 , 23 .
[0107] Once the assembly is coupled, as previously describe, and during the working operations, the tooth 10 is subjected at its tip to different forces. Said forces make that reactions forces with orthogonal components appear on said tip:
Normal force or radial force: in a same direction of the imaginary line between the center line of the cutter head and the point of the tooth, applied on a normal surface. Tangential force: perpendicular to the normal force and applied on the working surface of the tooth. Parallel to the ground. Lateral force: Mainly caused by the interaction of neighboring cuts.
[0111] As already described, the teeth and adaptors are ready to be stabilized to resist the normal, and tangential forces. The unexpected inverse forces in prior art solutions make some of the components of the assembly move or even break, therefore showing that the assembly is not completely stabilized against all the possible reaction forces.
[0112] Once the tooth and the adaptor have been coupled the assembly is ready to work on the cutter head. When the point of the tooth is subjected to tangential forces, the surfaces where reactions are created, to equilibrate said forces, are the first segment on the lower surface of the tooth and the upper surface of the main body of the nose, near the forward end 19 of the main body. With these contact surfaces between the tooth and the adaptor the tangential forces are counteracted to resist the efforts and diminish the strain in critical points of the assembly as well as in the pin.
[0113] However, when the unexpected inverse forces appear, usually when working on hard soil, it is necessary to counteract the same and the reactions are translated to the first segment on the upper surface of the nose of the tooth and on the lower surface of the projections ( FIG. 19 ).
[0114] Due to the projections on the tooth (and the grooves in the adaptor) placed near the center of both members, the maximum effort that has to be resisted by the coupling is placed in the neutral part of said coupling. | The tooth and adaptor for dredging machines object of the present invention relates to a tooth which, attached to an adaptor, creates an assembly the purpose of which is to deepen and clean the beds of ports, rivers, channels, etc., removing therefrom sludge, stones, sand, etc., the adaptors being attached to the blades thus forming the cutter head of the dredging machine. The constructive features of the coupling between the tooth and the adaptor allow a great stability between both elements, among other advantages. | 4 |
TECHNICAL FIELD OF THE INVENTION
The present invention is directed, in general, to wireless communications networks and, more specifically, to a time division multiple access system capable of providing multiple single-phase access.
BACKGROUND OF THE INVENTION
The field of wireless communications encompass a variety of products, including personal devices such as pagers, cellular phones, and PCS phones, and information systems, such as wireless LANs (local area networks) and smaller wireless office networks. These products are widely used due to their convenience and comparatively low cost. This widespread usage has greatly burdened the available RF bandwidth used by these devices.
To maximize usage of the available bandwidth, a number of multiple access technologies have been implemented to allow more than one subscriber to communicate simultaneously with each base transceiver station (BTS) in a wireless system. These multiple access technologies include time division multiple access (TDMA), frequency division multiple access (FDMA), and code division multiple access (CDMA). These technologies assign each system subscriber to a specific traffic channel that transmits and receives subscriber voice/data signals via a selected time slot, a selected frequency, a selected unique code, or a combination thereof.
TDMA technology is used in wireless computer networks, paging (or wireless messaging) systems, and cellular telephony. In a TDMA protocol, each device (e.g., pager, cell phone, laptop PC) receives and/or transmits data in an assigned channel that corresponds to a specific time slot (or phase) in a specific frequency bandwidth (typically 30 KHz wide).
Additionally, addresses may be used within each channel to distinguish between users and to increase thereby the number of users that a TDMA wireless network may serve at one time. This is particularly true in paging systems and wireless LANs, where a mobile unit (e.g., pager or laptop PC) does not continually receive data traffic from a network BTS, but rather receives data traffic in large bursts that are separated by periods of inactivity. Thus, for example, a pager having address “7” will only respond to data if the data is received in the correct frequency bandwidth and in the correct phase (time slot), and if the data has the correct address (i.e., “7”) in the header.
Within a selected frequency bandwidth, a TDMA user device may be assigned to receive data sent to the correct address in one fixed phase/time slot. This operating mode is sometimes referred to as “single phase” operation. For example, if the pager or computer used by User A is operating in single-phase mode, the device may receive only data that is sent to Address 4 in Phase 1 of Frequency Band X.
Alternatively, a TDMA user device may be assigned to receive data sent to the correct address in one phase/time slot that may vary. This operating mode is sometimes referred to as “any phase” operation. For example, if the pager or computer used by User A is operating in any-phase mode, the device may receive data sent to Address 4 in Phase 1 of Frequency Band X at one point in time, but at another point in time may receive data sent to Address 4 in Phase 2 of the same Frequency Band X. In this manner, if a large number of user addresses are added to the wireless network in Phase 1, the wireless network can use the any-phase mode to send data to User A in Phase 2.
Finally, a TDMA user device may be assigned to receive data sent to the correct address in all of the phases/time slots. This operating mode is sometimes referred to as “all phase” operation. For example, if the pager or computer used by User A is operating in all-phase mode, the device receives all data sent to Address 4 in Phases 1, 2 and 3 of Frequency Band X. This mode allows a large amount of data to be sent in a relatively short period of time to a single device, by is rarely used because it limits the number of users that may access the wireless network.
The prior art systems do not provide sufficient flexibility to allow a wireless mobile unit to receive data in more than one phase, but less than all of the phases, as in the case of all-phase mode. Typically, if a BTS sends data in more than one phase to a mobile device, the mobile device defaults to an all-phase mode of operation. This causes the mobile device to receive and to process data in every phase, including phases that do not contain data intended for the mobile device.
Furthermore, the prior art systems do not provide sufficient flexibility to allow a wireless mobile unit to receive data sent to different addresses in multiple phases. The address of a mobile unit in the prior art systems is always the same in each phase, whether the mobile unit is operating in single phase mode, any phase mode, or all phase mode.
There is therefore a need in the art for wireless networks and wireless devices that allow the wireless device to receive data in more than one phase, but less than all of the phases, as in the case of all-phase mode. There is a further need in the art for wireless networks and wireless devices that allow the wireless device to receive data sent to different addresses in multiple phases.
SUMMARY OF THE INVENTION
To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide, for use in a TDMA wireless communications network, a communications device that is capable of receiving data from a base station in a variable number of up to N phases, including one phase (single phase mode), N phases (all phase mode), and M phases (multi-phase mode), where M is less than N. The present invention implements the multi-phase mode of operation by capturing data from all phases (as in all phase mode) and discarding data from all phases except selected phases that are assigned to the wireless communications device. Furthermore, the wireless communications device can also be assigned different network addresses within each assigned phase, and both the assigned phase(s) and the assigned network address9es) can be modified “on-the-fly” by the base station during routine operations.
Accordingly, in one embodiment of the present invention, there is provided, for use in a time division multiple access (TDMA) wireless network, a wireless communications device comprising 1) a receiver capable of receiving a TDMA signal transmitted from a base station in the wireless network, the TDMA signal comprising a plurality of user data streams arranged in N phases; and 2) a data controller capable of processing the user data streams in a multiphase mode, the multi-phase mode enabling the data controller to retrieve from M selected ones of the N phases of the TDMA signal at least one user data stream directed to the wireless communications device, where M may be greater than 1 and is less than N.
In another embodiment of the present invention, the data controller retrieves user data streams from all N phases and processes only data retrieved from the M selected phases.
In still another embodiment of the present invention, a value of M is modifiable.
In yet another embodiment of the present invention, the value of M is modified by the base station.
In a further embodiment of the present invention, the data controller determines a transmitted user address associated with the at least one retrieved user data stream and processes the at least one retrieved user data stream if the transmitted user address is the same as an assigned user address associated with the wireless communications device.
In a yet further embodiment of the present invention, the assigned user address is modifiable by the base station.
In a still further embodiment of the present invention, the data controller determines a first transmitted user address associated with a first one of the at least one retrieved user data stream and a second transmitted user address associated with a second one of the at least one retrieved user data stream and processes the first and second retrieved user data streams if the first and second transmitted user addresses are the same as a first assigned user address and a second assigned user address associated with the wireless communications device.
In yet another embodiment of the present invention, the first assigned user address is different than the second assigned user address.
The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.
Before undertaking the DETAILED DESCRIPTION, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like numbers designate like objects, and in which:
FIG. 1 illustrates an exemplary wireless network in accordance with one embodiment of the present invention;
FIG. 2 is a timing diagram depicting exemplary TDMA data traffic in a wireless network in accordance with one embodiment of the present invention;
FIG. 3 illustrates phase and address assignments of a plurality of users in an exemplary wireless network in accordance with one embodiment of the present invention;
FIG. 4 illustrates an exemplary mobile unit in accordance with one embodiment of the present invention;
FIG. 5 is a flow chart depicting the operation of the exemplary mobile unit in FIG. 2 in accordance with one embodiment of the present invention;
FIG. 6 is a flow chart depicting the operation of the exemplary mobile unit in FIG. 4 in accordance with one embodiment of the present invention; and
FIG. 7 is a flow chart depicting the operation of the exemplary base transceiver station in FIG. 5 in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
FIGS. 1 through 7, discussed below, and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged TDMA wireless communications network.
FIG. 1 illustrates an exemplary wireless network 100 in accordance with one embodiment of the present invention. The wireless network 100 comprises a plurality of cell sites 121 - 123 , each containing one of the base transceiver stations, BTS 101 , BTS 102 , or BTS 103 . In a preferred embodiment of the present invention, the wireless telephone network 100 is a TDMA-based network. Base transceiver stations 101 - 103 are operable to communicate with a plurality of mobile units (M) 111 - 114 . Mobile units 111 - 114 may be any suitable wireless devices, including conventional cellular telephones, PCS handset devices, portable computers, metering devices, and the like.
Dotted lines show the approximate boundaries of the cells sites 121 - 123 in which base transceiver stations 101 - 103 are located. The cell sites are shown approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the cell sites may have other shapes, such as hexagonal, depending on the cell configuration selected and natural and man-made obstructions.
BTS 101 , BTS 102 and BTS 103 transfer voice and data signals between each other and the public telephone system (not shown) via communications line 131 . Communications line 131 may be any suitable connection means, including a T1 line, a T3 line, a fiber optic link, a network backbone connection, and the like. In some embodiments, BTS 101 , BTS 102 and BTS 103 may be wirelessly linked to one another and/or the public telephone network by a satellite link.
In the exemplary wireless network 100 , mobile unit 111 is located in cell site 121 and is in communication with BTS 101 , mobile unit 113 is located in cell site 122 and is in communication with BTS 102 , and mobile unit 114 is located in cell site 123 and is in communication with BTS 103 . The mobile unit 112 is located in cell site 121 , close to the edge of cell site 123 . The direction arrow proximate mobile unit 112 indicates the movement of mobile unit 112 towards cell site 123 . At some point as mobile unit 112 moves into cell site 123 and out of cell site 121 , a “handoff” will occur.
A “handoff” is a well-known process for transferring control of a call from a first cell to a second cell. For example, if mobile unit 112 is in communication with BTS 101 and senses that the signal from BTS 101 is becoming unacceptably weak, mobile 112 may then switch to a BTS that has a stronger signal, such as the signal transmitted by BTS 103 . Mobile unit 112 and BTS 103 establish a new communication link and a signal is sent to BTS 101 and the public telephone network to transfer the on-going voice and/or data signals through the BTS 103 . The call is thereby seamlessly transferred from BTS 101 to BTS 103 .
The base transceiver stations, BTS 101 -BTS 103 , communicate with mobile units 111 , 112 , 113 and 114 by means of a time division multiple access (TDMA) protocol. The TDMA protocol divides the available RF spectrum into a plurality of data traffic channels and one or more control channels. Each data traffic channel and control channel comprises a specific frequency band that is, for example, 30 kilohertz wide, and a specified phase (or time slot) within the specified frequency band. The mobile units transmit on one 30 KHz wide carrier frequency signal located at, for example, approximately 800 MHz, and receive on another 30 KHz wide carrier frequency signal located, for example, about 45 MHz higher.
BTS 101 , BTS 102 , and BTS 103 transmit control messages in a forward control channel to the respective ones of mobile units 111 , 112 , 113 , and 114 and receive control messages in a reverse control channel from the mobile units. The control messages are transmitted in pre-determined control channels and are used to establish, to maintain, and to break down the data traffic communication links carrying the voice and/or data signals between the base transceiver stations and the mobile units. As will be described below in greater detail, BTS 101 through BTS 103 use forward control channels to send to mobile unit 111 through mobile unit 114 control messages that switch the operating modes of mobile units 111 - 114 to receive data in a data traffic channel in more than one phase at a time, using different network addresses, and without operating in an “all-phase” operating mode.
FIG. 2 is a timing diagram 200 depicting TDMA data traffic in exemplary wireless 100 network in accordance with one embodiment of the present invention. The TDMA traffic depicted in FIG. 2 represents streams of data traffic transmitted in a forward data traffic channel from any one of the base transceiver stations, BTS 101 -BTS 103 , to any one of mobile units 111 - 114 .
A burst of TDMA data traffic begins with a synchronization block 201 that synchronizes the receivers in mobile units 111 - 114 to thereby enable the mobile units to capture the data traffic following synchronization block 201 . In the exemplary timing diagram 200 shown, the data traffic is broken into three phases, or time slots, that follow each other in sequence. The first phase block 202 a, labeled “Phase 1,” is followed by a second phase block 203 a, labeled “Phase 2,” which is followed in turn by a third phase block 204 a, labeled “Phase 3.” The Phase 1-Phase 2-Phase 3 sequence repeats until an entire frame of data traffic is transmitted. The length of a data traffic frame may vary according to the number of phases in each frame, the number of bits in each phase, and other system parameters.
When a communication link is established between a base transceiver station and one of the mobile units, control messages direct the mobile unit to receive data in one or more of Phase 1, Phase 2, or Phase 3. The number of bits in each phase may vary according to selected system parameters. For example, a phase may be only one bit wide. In such a scenario, a block of data sent to the mobile unit is converted into a data stream that is transmitted one bit at a time in Phase 1. A mobile unit operating in Phase 1 in single-phase mode reads only every third bit. In alternate embodiments, the number of bits in each phase may be greater than one bit, such as a four-bit phase or an eight-bit phase.
FIG. 3 illustrates phase and address assignments of a plurality of network users in exemplary wireless network 100 in accordance with one embodiment of the present invention. The network users are arbitrarily labeled “User A” through “User S.” In the exemplary embodiment, the users may be assigned one of eight addresses within each phase. For example, User A is assigned binary address 000 in Phase 1. User B is assigned binary address 001 in Phase 1, User C is assigned binary address 010 in Phase 1, etc.
Several of the network users are assigned to receive data in more than one phase and at different addresses. For example, User A receives a data stream in Phase 1 at binary address 000 and receives a data stream in Phase 2 at binary address 010. Likewise, User B receives a data stream in Phase 1 at binary address 001 and in Phase 2 at binary address 100. User F and User M also receive data in multiple phases, although User F has binary address 101 in both phases, whereas User M receives data at different addresses in each phase.
The phase and address assignments shown in FIG. 3 illustrate the advantages of the present application. The devices used by User A through User M may be assigned addresses and phases for receiving data in a flexible manner by wireless network 100 . Thus, as new users are added to the network, and old users are deleted from the network, addresses may be allocated or reallocated to selected users in each phase without reconfiguring the address and phase assignments of other users. This may be done without causing the user's mobile device to default to an all-phase mode.
FIG. 4 illustrates exemplary mobile unit 112 in accordance with one embodiment of the present invention. Mobile unit 112 comprises an antenna 401 , transceiver front end circuitry 402 , demodulation circuitry 403 and modulation circuitry 404 . Transceiver front end circuitry 402 contains low-noise amplification circuitry for amplifying forward channel RF signals received by antenna 401 . The amplified forward channel RF signals are demodulated by demodulation circuitry 403 , thereby recovering the baseband data traffic or control message signal that was sent in the forward channel. Modulation circuitry 404 receives data traffic and control messages from control processor 405 and modulates these signals to produce a modulated reverse channel RF signal. Transceiver front end circuitry 402 also contains power amplifiers for amplifying the modulated reverse channel RF signals received from modulation circuitry 404 .
Within mobile unit 112 , control processor 405 controls the flow of data traffic that is being sent and received by transceiver front end circuitry 402 . Control processor 405 receives data and instructions from user application 409 and also sends data to user application 409 . Control processor 405 receives forward channel data traffic and command messages from demodulation circuitry 403 and stores the received data/commands in memory 406 . Control processor 405 may also store data and/or commands generated by user application 409 in memory 406 in preparation for transfer to modulation circuitry 404 and subsequent transmission in the reverse channel by transceiver front end circuitry 402 .
User application 409 is intended as a “generic” representation of a user device control module that varies according to the type of mobile unit in which user application 409 is disposed. For example, if mobile unit 112 is a portable computer, user application 409 may be, for example, an operating system program, a word processing application, an e-mail application, a web browser application, or the like, or a combination of the foregoing. If mobile unit 112 is a wireless messaging device, such as a pager, user application 409 may be the user interface software and hardware that displays messages to the user and receives user inputs for transmission to wireless network 100 .
Control processor 405 monitors the control channels in wireless network 100 via transceiver front end circuitry 402 and demodulation circuitry 403 in order to receive control messages from wireless network 100 . When mobile unit 112 first accesses wireless network 100 , control messages are sent to mobile unit 112 and control processor 405 that assign mobile unit 112 to a selected phase and a selected address in the TDMA access scheme. Control processor 405 stores the phase information in Assigned Phase(s) table 407 and stores the network address information in Assigned Phase Address table 408 in memory 406 . Thereafter, control processor 405 processes data traffic received in the correct phase and having the correct address and continues to monitor the control channel for control messages that may subsequently modify the phase and address assignments of mobile unit 112 .
FIG. 5 illustrates exemplary base transceiver station (BTS) 101 in accordance with one embodiment of the present invention. BTS 101 comprises an antenna 501 , transceiver front end circuitry 502 , demodulation circuitry 503 and modulation circuitry 504 . Transceiver front end circuitry 502 contains low-noise amplification circuitry for amplifying reverse channel RF signals received by antenna 501 . The amplified reverse channel RF signals are demodulated by demodulation circuitry 503 , thereby recovering the baseband data traffic or control message signal that was sent in the reverse channel by one or more of the mobile units. Modulation circuitry 504 receives data traffic and control messages from data traffic controller 505 and modulates these signals to produce a modulated forward channel RF signal. Transceiver front end circuitry 502 also contains power amplifiers for amplifying the modulated forward channel RF signals received from modulation circuitry 504 .
Within BTS 101 , data traffic controller 505 controls the flow of data traffic that is being sent and received by transceiver front end circuitry 502 . Data traffic controller 505 receives voice and/or data traffic destined for a mobile unit from other bases transceiver stations or the public phone system via communications line 131 and network interface 509 . Data traffic controller 505 also sends voice and/or data traffic received form one or more mobile units to other base transceiver stations, to a server, or to the public phone system via communications line 131 and network interface 509 .
Data traffic controller 505 is coupled to a configuration database 506 that is used to store the phase information and the address information of every mobile unit that is in communication with BTS 101 . Network Phase Assignments table 507 stores the current phase assignment of each user in communication with BTS 101 . Network Address Assignments table 508 stores the current address assignment in each phase of each user in communication with BTS 101 . Data traffic controller 505 transmits data traffic in the correct phase and at the correct address according to the information stored in Network Phase Assignments table 507 and in Network Address Assignments table 508 .
If traffic conditions require modifying the bandwidth available to a particular user, data traffic controller 505 is capable of changing phase and address data in Network Phase Assignments table 507 and in Network Address Assignments table 508 . Data traffic controller 505 can then transmit the new phase and address information to the user by means of control messages in the forward control channel.
FIG. 6 is a flow chart 600 depicting the operation of exemplary mobile unit 112 in FIG. 4 in accordance with one embodiment of the present invention. In an advantageous embodiment of the present invention, mobile unit 112 uses a “capture and discard” technique to receive traffic data in multiple phases and at multiple addresses. According to this technique, mobile unit 112 operates in a modified all-phase mode of operation. Mobile unit 112 therefore captures all traffic data and discards traffic data from unwanted phases.
Mobile unit 112 initiates the establishment of a communication link with wireless network 100 and BTS 101 by transmitting in a control channel an origination message that contains, or is followed by, identification (ID) information that identifies mobile unit 112 to wireless network 100 (process step 601 ). In response to the origination message transmitted by mobile unit 112 , BTS 101 transmits a phase assignment and an address assignment to mobile unit 112 . The phase assignment may initially be for single-phase mode of operation, and the address assignment may assign only one address within that single phase.
Mobile unit 112 receives the phase and address assignments from BTS 101 (process step 602 ) and begins to capture all data traffic in all phases of the data traffic channels (process step 603 ). Mobile unit 112 filters out the data traffic in the assigned phase(s) by discarding data from any unwanted phase(s) (process step 604 ). For example, if mobile unit 112 is assigned to receive data traffic in phase A and phase C, mobile unit 112 captures data traffic from all phases and discards the data captured from phase B. Finally, mobile unit 112 verifies the address associated with the data traffic from the assigned phases and processes the received data if the address matches the assigned address given to mobile unit 112 by BTS 101 (process step 605 ).
FIG. 7 is a flow chart 700 depicting the operation of BTS 101 in FIG. 5 in accordance with one embodiment of the present invention. Initially, BTS 101 receives an origination message from mobile unit 112 and verifies the ID information provided by mobile unit 112 (process step 701 ). If the ID information provided by mobile unit 112 indicates that mobile unit 112 is authorized to access wireless network 100 , BTS 101 transmits a control channel message that assigns a phase assignment and an address assignment to mobile unit 112 (process step 702 ).
Thereafter, as BTS 101 receives data traffic directed to mobile unit 112 from other portions of wireless network 100 or from the public telephone system (process step 703 ), BTS 101 transmits the data traffic to mobile unit 112 in the assigned phase(s) and at the assigned address(es) that were previously sent to mobile unit 112 (process step 704 ). If the amount of data traffic directed to mobile unit 112 is large, BTS 101 may transmit control messages to mobile unit 112 directing mobile unit 112 to receive data traffic in additional phases and at different addresses within the additional phases in order to increase the bandwidth available to mobile unit 112 .
Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form. | A communications device for receiving data from a base station in up to N phases, including in one phase, all phases, or multiple phases. The multi-phase mode captures data from all phases and discards all but selected phases assigned to the wireless communications device. The wireless communications device may have different network addresses within each phase and the phases and network addresses may be modified during operation. The wireless communications device includes 1) a receiver for receiving a TDMA signal transmitted from a base station, the TDMA signal having user data streams arranged in N phases, and 2) a data controller for processing the user data streams in a multi-phase mode, wherein the data controller retrieves from M selected phases at least one user data stream directed to the wireless communications device, where M may be greater than 1 and is less than N. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of Korea patent Application No. 2000-65483, filed on Nov. 6, 2000.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a method for controlling a continuously variable transmission (CVT), and more particularly to a method capable of automatically controlling a speed ratio between economic and power modes without manual mode selection.
(b) Description of the Related Art
An automotive transmission is a device for transmitting engine torque to a drive shaft of a vehicle in variable speed ratios, and transmissions are usually classified into manual, automatic, and continuously variable transmissions (CVT).
Unlike manual and automatic transmissions that adapt a step variable is gear mechanism to provide fixed speed ratios, the CVT can vary the speed ratio continuously.
Accordingly, engine revolution speed can be optimally selected such that an engine operates at a preferred revolution-per-minute (rpm) relative to one of intended conditions such as maximum mileage, maximum output, minimum noise, minimum toxic gas emission, etc.
Typically, the speed ratio of the CVT is determined by engine torque-rpm maps that are preset according to intended conditions such as maximum mileage (economy mode) and maximum power (power mode).
FIG. 4 is a graph showing engine performance curves. Curve 1 indicates a plurality of iso-Brake Specific Fuel Consumption (iso-BSFC) curves and P 0 indicates a point where the fuel consumption is the lowest. Curve 2 indicates a plurality of iso-power curves, which are equivalent to graphs of the equation y=power/x with various values of power, because the engine power is calculated by multiplying the engine rpm by the engine torque. Curve 3 indicates a maximum mileage curve, which passes through the lowest fuel consumption point P 0 . Curve 4 indicates a maximum power control curve.
In the CVT, the speed ratio can be randomly shifted in an available range such that the engine rpm and the engine torque can be randomly set regardless of the vehicle speed.
As a result, the CVT is controlled in such a way that the engine performs with a specific torque and rpm along the maximum mileage curve C 3 to provide maximum mileage of a vehicle, and it performs with another specific torque and rpm along the maximum power control curve C 4 for maximum power driving.
Accordingly, the speed ratio of the CVT is determined on the basis of a throttle valve opening and vehicle speed values specified in the map corresponding to the control mode that are determined relative to the intended driving condition, such as maximum mileage or maximum power.
Therefore, in order to accommodate the driver's intention, a conventional CVT control method requires mode selection input from the driver, and the mode selection process can cause the speed ratio to be abruptly changed, resulting in shift shock, vibration, and engine shaking.
SUMMARY OF THE INVENTION
The present invention has been made in an effort to solve the above problems of the prior art.
It is an object of the present invention to provide a CVT control method capable of determining an optimal speed ratio that lies betweenspeed ratios of the economy and power modes without manual mode selection.
To achieve the above object, a CVT control method of the present invention comprises the steps of calculating a target speed ratio of a CVT between maximum and minimum values of a plurality of speed ratios preset corresponding to a plurality of engine operation modes and controlling the CVT according to the target speed ratio.
The step of calculating the target speed ratio includes the steps of calculating a driving pattern index on the basis of throttle opening change rate, throttle operation frequency, and vehicle acceleration, and calculating the target speed ratio on the basis of the driving pattern index.
The target speed ratio can be calculated using a formula such as Tm=(Tp−Te)X+Te, where X is the driving pattern index, Te is an economy mode speed ratio, Tp is a power mode speed ratio, and Tm is the target speed ratio between Te and Tp.
The driving pattern index X can be calculated using a formula: X = ( α × a A0 + β × b B0 + γ × c C0 ) / 3
where, α, β, and γ are proportional weights;
a, b, and c are respectively a learned throttle opening change rate, learned throttle operation frequency, and learned vehicle acceleration; and
A 0 , B 0 , and C 0 are respectively a preset throttle opening change rate, preset throttle operation frequency, and preset vehicle acceleration.
In addition, the CVT control method according to the present invention can further includes the steps of determining if a learning condition is satisfied, and learning the driving pattern index when the learning condition is satisfied.
The learning condition can be defined as 'The present change rate of throttle opening is different from an average change rate of throttle opening up to this point by more than a predetermined difference, or the present throttle operation frequency is different from an average throttle operation frequency up to this point by more than a predetermined frequency, or the present acceleration is different from an average acceleration up to this point by more than a predetermined acceleration.
Furthermore, the CVT control method of the present invention can further include the step of determining whether the vehicle is running at a constant speed, wherein the step of calculating a driving pattern index is performed if the vehicle is not running at a constant speed.
When the vehicle is running at a constant speed, the target speed ratio is determined to be one of default engine operation modes, which is preferably an economy mode.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention,and together with the description, serve to explain the principles of the invention:
FIG. 1 is a block diagram illustrating a CVT control system according to the present invention;
FIG. 2 is a flow chart illustrating a CVT control method according to a preferred embodiment of the present invention;
FIG. 3 is a flow chart illustrating sub-steps of a fuzzy calculation step of FIG. 2; and
FIG. 4 is a graph illustrating exemplary engine performance curves.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will be described hereinafter with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating a CVT control system according to the present invention.
As shown in FIG. 1, the CVT control system comprises a throttle sensor 110 for sensing throttle opening, a speed sensor for sensing vehicle speed, a CVT 130 for transmitting torque from an engine (not shown) to an output shaft, and a transmission control unit (TCU) 140 electrically connected to the throttle sensor 110 , speed sensor 120 , and CVT 130 such that the TCU 140 controls the CVT 130 on the basis of parameters from the throttle and speed sensors 110 and 120 .
A CVT control method for the above structured CVT control system will now be described with reference to the drawings.
In FIG. 2, the TCU 140 determines whether the vehicle is running at a constant speed or not on the basis of the parameters from the speed sensor 120 at step S 210 .
If the vehicle is running at a constant speed at step S 210 , the TCU 140 calculates a target speed ratio for the CVT according to a default control mode at step S 230 and then controls the CVT according to the calculated target speed ratio at step S 260 . In this case, a mode conversion is not required such that the CVT control is performed in the preset default control mode. It is preferred to set an economy mode as the default.
If it is determined that the vehicle is not running at a constant speed at step S 210 , the TCU 140 starts a fuzzy calculation for obtaining a target speed ratio at step S 220 . The fuzzy calculation is a calculation to determine the speed ratio between a preset power mode speed ratio and a preset economy mode speed ratio using a learning process.
The fuzzy calculation method for obtaining the target speed ratio in step S 220 will be described in more detail hereinafter, with reference to FIG. 3 .
In FIG. 3, the TCU 140 firstly receives the throttle opening and vehicle speed parameters detected by the throttle opening sensor 110 and vehicle speed sensor 120 at step S 310 . The vehicle speed obtained at step S 210 can also be used instead of sensing again at step S 310 .
Next, the TCU 140 calculates the throttle opening change rate, throttle operation frequency, and vehicle acceleration at step S 320 .
The throttle opening change rate means how fast an acceleration pedal is depressed , that is, how fast the throttle opening is changed.
The throttle operation frequency means how frequently the acceleration pedal is operated in a predetermined period.
On the basis of the above parameters regarding the throttle opening change rate, throttle operation frequency, and vehicle acceleration, a driving pattern index (X) is calculated at step S 330 , using equation 1. X = ( α × a A0 + β × b B0 + γ × c C0 ) / 3 Equation 1
In Equation 1, parameters a, b, and c respectively indicate a learned throttle opening change rate, a learned throttle operation frequency, and a learned vehicle acceleration.
The learned throttle opening change rate “a” is obtained by adding a throttle opening change rate index (F a ) to the previously calculated throttle opening rate. The result value is mapped to 0 if it is less than 0, and mapped to A 0 if it is greater than A 0 . It is preferred that the throttle opening change rate index (F a ), which is learned as driving history is accumulated, is initially set to 0.
The learned throttle operation frequency “b” is calculated on the basis of throttle operation index (F b ) and B 0 , and a learned vehicle acceleration “c” is calculated on the basis of vehicle acceleration index (F c ) and C 0 , in the same way as the learned throttle opening rate “a.”
The parameters A 0 , B 0 , and C 0 respectively indicate a preset throttle opening change rate, a preset throttle operation frequency, and a preset vehicle acceleration. The preset throttle opening change rate, preset throttle operation frequency, and preset vehicle acceleration A 0 , B 0 , and C 0 are respectively set to a maximum throttle opening change ratio, a maximum throttle operation frequency, and a maximum vehicle acceleration that can be generated by the driver's manipulation.
Accordingly, the pattern indices according to the throttle opening change rate, throttle operation frequency, and vehicle acceleration can be expressed as a/A 0 , b/B 0 , and c/C 0 , each value of which is greater than 0 and less than 1.
Also, the constants α, β, and γ are weights for the corresponding parameters. These constants are set as positive numbers under the condition “α+γ=1.”
Thus, the driving pattern index (X) calculated through Equation 1 has a value greater than 0 and less than 1.
After the calculation of the driving pattern index (X), the TCU 140 calculates a target speed ratio (Tm) at step S 340 .
The target speed ratio is calculated between the economy mode speed ratio (Te) and the power mode speed ratio (Tp) on the basis of the driving pattern index (X) using Equation 2.
Tm= ( Tp−Te ) X+Te Equation 2
The driving pattern index (X) has a value between 0 and 1 through Equation 2 such that the target speed ratio (Tm) has a value between the economy mode speed ratio (Te) and the power mode speed ratio (Tp).
Referring back to FIG. 2, after the calculation of the target speed ratio at step S 220 , the TCU 140 determines whether a predetermined learning condition is satisfied at step S 240 . The predetermined learning condition can be deliberately set as in the following example: The present change rate of the throttle opening is different from an average change rate of the throttle opening up to this point by more than a predetermined difference, or the present throttle operation frequency is different from an average throttle operation frequency up to this point by more than a predetermined frequency, or the present acceleration is different from an average acceleration up to this point by more than a predetermined acceleration amount.
If the learning condition is satisfied, the TCU 140 starts learning the present driving pattern represented by indices including throttle opening, throttle operation frequency and vehicle acceleration at step S 250 , and then controls the CVT according to the target speed ratio.
The driving pattern learning can be performed using a function that processes the driving pattern index in such a way that a function increases/decreases the throttle opening index according to whether the throttle opening change rate is greater than or less than the average throttle opening change rate, increases/decreases the throttle operation frequency index according to whether the throttle operation frequency is greater than or less than the average throttle operation frequency, and increases/decreases the vehicle's acceleration index according to whether the vehicle's acceleration is greater than or less than the vehicle's average acceleration.
Finally, the TCU 140 controls the CVT according to the previously calculated target speed ratio at step S 260 . If the learning condition is not satisfied at step S 240 , the TCU 140 controls the CVT 130 according to the target speed ratio calculated at step S 220 without learning the driving pattern.
As described above, the CVT control method of the present invention controls the CVT in a continuously variable speed ratio between the economy and power modes on the basis of the driving pattern index so as to reflect the driver's driving pattern well as well as in the economy mode so as to obtain the maximum mileage when the vehicle is running at a constant speed. This eliminates the inconvenience of manual mode selection.
Furthermore, the driving pattern index is accumulatively updated and learned to reflect the latest driving pattern so as to prevent discontinuous driving pattern index changes in spite of the driver's abrupt change of the driving pattern, resulting in stable speed ratio control.
While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A CVT control method includes the steps of calculating a target speed ratio of a CVT between maximum and minimum values of a plurality of speed ratios preset corresponding to a plurality of engine operation modes, and controlling the CVT according to the target speed ratio. | 8 |
This is a continuation of application Ser. No. 85,688, filed Oct. 17, 1979, abandoned.
BACKGROUND OF THE INVENTION
This application relates to apparatus for synchronizing the aiming and firing of the rapid-fire gun of a microballistic printer or the like.
In copending application Ser. No. 39,372, filed May 15, 1979, I describe a printer which directs a plurality of solid projectiles such as balls about one millimeter in diameter in extremely rapid succession against a printing medium such as a ribbon overlying a sheet of paper. In the gun of the printer, which is movable about orthogonal axes for targeting, balls are introduced successively into a resilient breech which is slightly smaller in diameter than the balls and behind which air is maintained under pressure. The ball is fired by pushing it sufficiently far into the breech to snap the ball through to the barrel side and allow the pressurized air to expand into the barrel and propel the ball outwardly.
In the ballistic printer disclosed in my copending application, it is extremely important that the aiming of the ball gun and the firing of projectiles therefrom be accurately synchronized relative to each other. If the ball gun is moved while a ball is traversing the barrel, the trajectory of the ball is disturbed in an unpredictable manner, causing the ball to strike the medium widely off target. If the aiming and firing steps are poorly synchronized or performed asynchronously, a significant number of balls will miss their mark, giving the sheet a speckled, aesthetically displeasing appearance.
In the previously disclosed ballistic printer, the synchronizing signal is obtained from a disc which rotates on a common shaft with a rotary saw blade used to inject the balls into the ball gun. The disc is formed with a plurality of equidistantly spaced apertures around its periphery equal in number to the teeth on the saw blade. A stationary photodetector disposed adjacent the periphery of the disc generates the synchronizing pulse. Accuracy of synchronization in a system of this type depends, of course, on the registry of the disc apertures with the teeth of the saw blade, which may be difficult to achieve reliably. In such a system, moreover, one is detecting only that a projectile should have been fired, rather than the event that a projectile actually has been fired.
SUMMARY OF THE INVENTION
One of the objects of my invention is to provide a ballistic printer which accurately directs projectiles against a printing medium.
Another object of my invention is to provide a ballistic printer which accurately synchronizes the aiming and firing of the print projectiles.
Still another object of my invention is to provide a ballistic printer which is capable of high-speed operation.
A further object of my invention is to provide a ballistic printer which is simple and inexpensive.
Other and further objects of my invention will be apparent from the following description.
In general, my invention contemplates apparatus fo synchronizing the aiming and firing of the gun of a microballistic printer in which a suitable sensor, such as a microphone, is used to detect the firing of a ball or other projectile by the ball gun. The output of the firing sensor is in turn used by the ball gun control system to determine when the ball has left the muzzle of the ball gun, allowing the ball gun to be aimed at a new target location. In the preferred form of my invention, the firing sensor comprises a microphone acoustically coupled to the air inlet supplying pressurized air to the pressure chamber of the ball gun. Alternatively, the firing sensor may comprise a microphone or an optical detector disposed adjacent the muzzle of the gun. By controlling the aiming of the ball gun in response to the actual firing of a projectile therefrom, I am able to achieve accurate synchronization of the aiming and firing steps, thereby permitting high-speed firing operation while retaining aiming accuracy.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings to which reference is made in the instant specification and in which like reference characters are used to indicate like parts in the various views:
FIG. 1 is a fragmentary front elevation of the gun and associated positioning assembly of my ballistic printer with the gun in a neutral position.
FIG. 2 is a fragmentary section of the ball gun and ball injector of my ballistic printer, taken along line 2--2 of FIG. 1.
FIG. 3 is a schematic diagram of the control circuit for the ball gun shown in FIG. 1.
FIG. 4 is a fragmentary elevation of the ball gun of my ballistic printer with an alternative form of firing sensor.
FIG. 5 is a fragmentary elevation of the ball gun of my ballistic printer with another alternative form of firing sensor.
FIG. 6 is a flowchart of a control subroutine used by the circuit shown in FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2, in one embodiment of my printer, indicated generally by the reference numeral 10, a gun indicated generally by the reference numeral 12 is arranged to direct a plurality of projectiles such as balls 14 successively against a ribbon 16 overlying a sheet of paper 18 on a platen 20. Balls 14 may be, for example, 0.8 mm diameter so as to produce a spot size on the paper of 0.3 mm diameter. A pair of vertical pivots 22 carried by a ring 24 support ball gun 12 for movement about a vertical pivot axis, while a pair of fixed horizontal pivots 26 suport ring 24, and hence the ball gun 12, for movement about a horizontal pivot axis. Ball gun 12 is thus capable of being independently pivoted around the X, or horizontal, axis and around the Y, or vertical, axis to direct successively fired balls 14 against desired impact points on the ribbon 16.
A deflection rod 28 moved in the direction of the X axis by an X actuator unit 38 shown schematically in FIG. 3 bears with its head 30 against a portion of the ball gun 12 disposed forwardly of the vertical pivot axis to pivot it through the desired angle around the Y axis. Similarly, a Y deflection rod 32 moved in the direction of the Y axis by a Y actuator unit 40 shown schematically in FIG. 3 bears with its head 34 against a portion of the ball gun 12 disposed forwardly of the horizontal pivot axis to pivot it through the desired angle in the Y direction. A tension spring 36 maintains ball gun 12 in intimate contact with the actuator heads 30 and 34.
Referring now to FIG. 3, actuators 38 and 40 are controlled by a computer 42 of any suitable type, such as an Intel 8048 or other microcomputer, associated with the printer 10. Units 38 and 40 supply position signals X and Y representing the instantaneous displacement of the rods 28 and 32 to the computer 42, which in turn supplies correction signals ΔX and ΔY to move the rods 28 and 32 to new positions if different from the current positions. The construction and operation of the actuator units 38 and 40, while in themselves forming no part of the present invention, are described in detail in my copending application Ser. No. 39,372.
Referring again to FIG. 2, in the ball injector of my printer 10, indicated generally by the reference numeral 44, a rotary saw blade 50 provided with teeth 52 guides balls 14 to be fired to the left as viewed in the figure along a channel 46 formed in a guide 48. A ball advance motor 54 indicated schematically in FIG. 3 drives saw blade 50 clockwise in response to a ball advance signal from computer 42. Balls 14 driven along channel 46 in this manner enter a second guide 56 which injects them into the rear of the ball gun 12, as will be described in more detail below.
Gun 12 includes a body 58 having a conical bore 60 which receives the gun barrel 62. The gun barrel 62, which is formed of a suitable resilient material, has an outer conical surface conforming to the conical bore 60 so that the barrel is self-locating in the housing or body 58. Barrel 62 has a length of about 3 mm in the embodiment shown and is formed with an inner cylindrical bore 64 of a diameter which is slightly greater than that of the balls 14. Bore 64 extends from the front of the barrel rearwardly toward a tapered portion 66 leading into a cylindrical sphincter or breech 70, having an opening 68 with a normal diameter, shown in dotted lines in FIG. 2, slightly less than that of the balls 14.
A recess 72 in the body 58 behind the conical bore 60 receives a loading guide 76 which bears against a shoulder 74 at the juncture between bore 60 and recess 72. Guide 76 has a central opening 78 of a diameter which is slightly greater than that of a ball 14 by, for example, 0.01 mm. I position a pressure seal 80 within recess 72 behind guide 76 and spaced therefrom by spacers 82. A spring clip 84 disposed in an annular recess 86 holds the pressure seal in position. I form the seal 80 with a central passage 87 having a diameter substantially equal to the diameter of a ball 14, which passage 87 leads from the outlet of guide 56 and is aligned with the opening 78 in guide 76. An air inlet 88 admits air under a pressure of 4 to 6 atmospheres through the wall of body 58 to the antechamber 90 between guide 76 and seal 80. The arrangement of my gun assembly is such that the rear of barrel 62 is spaced from guide 76 to form a pressure chamber 92.
I assemble a designator cam 94 of the assembly 12 on a reduced forward end portion of the main body 58 of the gun. Cam 94 is so formed as to provide a surface contour on which actuator heads 30 and 34 ride.
Computer 42 is programmed in a manner known to those skilled in the art to follow a subroutine such as shown in FIG. 6 for successively directing N balls 14 against the ribbon 16 at respective locations (X1, Y1) through (XN, YN). Such a subroutine may, for example be entered to print a particular stroke of a character supplied to the computer by an input device such as a keyboard 106. After entering the subroutine (block 114), the program first initializes the index I at 1 (block 116). Next, the program enables the ball advance motor 54 (block 118) to cause blade 50 to begin feeding balls. After enabling the ball advance, the program provides (block 120) suitable output signals ΔX and ΔY to respective X and Y actuator units 38 and 40 to cause them to aim the gun assembly at a location which is initially (X1, Y1).
In operation of my microballistic printer, if the apparatus is in the quiescent state, blade 50 will have advanced balls to such a position that the leading ball engages the breech 70 so as to form a seal therewith to permit the pressure buildup in pressure chamber 92. From the leading ball counting rearwardly three balls, there will be a ball 14 which is positioned at the rear of seal 80 and which is in engagement with the ball 14 about to emerge from the guide 56.
As the blade 50 rotates, the force of a tooth 52 thereof is exerted on the line of balls 14 between the ball in the breech 70 and the last ball being acted on by the tooth so as to dislodge the ball from the breech. This permits the air in the pressure chamber 92 to expand into the bore 64, expelling the ball 14 therefrom at an exit velocity of from about 20 to about 40 meters per second. After the first ball has been fired, the next ball moves into position in opening 68 to form a seal therewith and the pressure in the chamber 92 again builds up to a value equal to the initial pressure of 4 to 6 atmospheres.
A side conduit 96 forming a T-junction in the air inlet 88 couples the inlet acoustically to a chamber 98 within which I dispose a pressure microphone 100 of any suitable type, such as a piezoelectric microphone, capacitor microphone or the like. The pressure drop occurring in chambers 90 and 92 when the ball 14 is fired propagates a wave along air inlet 88 and conduit 96 to chamber 98, in which it produces a negative-going output from microphone 100. In response to the microphone output, an edge sensor 104 of any suitable type known to the art, such as a differentiator followed by a Schmitt trigger followed by a one-shot multivibrator, supplies computer 42 with a synchronizing pulse. Preferably, air inlet 88 is formed with a constriction 102 on the upstream side of conduit 96 to reduce the rate of pressure drop to a rate readily detectable by microphone 100. To minimize undesirable delay, side conduit 96 and the portion of air inlet 88 connecting conduit 96 to the ball gun 12 should be relatively short.
After aiming the ball gun 12, the subroutine waits (block 122) for a signal from microphone 100 indicating that the ball 14 has been fired. Then subroutine then delays (block 124) for a period sufficient to permit the ball 14 just fired to exit from the ball gun 12. In the ball gun 12 shown, a delay of about 0.3 milliseconds after firing from the breech is sufficient to allow the ball 14 to travel the length of the bore 64. Next, the subroutine tests I to see if it equals N, indicating that N balls have already been fired (block 126). If more balls are to be fired (i.e., I is less than N), the subroutine increments I by one (block 128) and then returns to block 120 to allow the ball gun to be aimed at a new target location. The subroutine continues along the loop comprising blocks 120 to 128, at a rate of up to 2000 times a second or more, as determined by the ball advance rate, until N balls have been fired, at which time the subroutine disables the ball advance motor 54 (block 130) and returns (block 132) to the program that had invoked the subroutine.
While I have shown a microphone 100 acoustically coupled to the air inlet 88 as the preferred means for fire detection, other means may also be employed. Thus, one may also dispose a microphone 108 adjacent to the exit of the barrel 64, as shown in FIG. 4, to sense the pressure wave created by the expanding air in the barrel when the ball 14 is fully expelled. Alternatively, if desired, one may optically sense the ball 14 as it leaves the barrel 64 by directing a light beam from a source 110 across the path of the exiting ball and sensing the beam by a suitable photodetector 112, as shown in FIG. 5. These alternative means, however, are less desirable than the microphone 100 shown in FIG. 2, since they do not sense the firing of the ball 14 until it has actually left the barrel 64. This inherent delay, coupled with the additional delays inevitably introduced by the external control circuit, limits the maximum firing rate that can be achieved while properly synchronizing aiming and firing.
It should also be noted that, rather than using actuator units 38 and 40 responsive to correction signals ΔX and ΔY, one may instead employ servo units having internal control loops which are directly responsive to desired position signals X and Y. Since, in such a case, the control loop is external to computer 42, the computer need only be programmed to supply the basic position signals X and Y rather than correction signals ΔX and ΔY.
It will be seen that I have accomplished the objects of my invention. My ballistic printer accurately directs projectiles against a printing medium by precisely synchronizing the aiming and firing of the print projectiles. My ballistic printer is capable of high-speed operation, while at the same time being simple and inexpensive.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of my claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is, therefore, to be understood that my invention is not to be limited to the specific details shown and described. | Apparatus for synchronizing the aiming and firing of the solid projectile gun of a microballistic printer or the like. In the preferred embodiment, a microphone acoustically coupled to an inlet used to supply pressurized air to the ball gun senses the pressure drop occurring in the ball gun pressure chamber when a ball is fired. The microphone output is used by the ball gun control system to determine when the ball has left the ball gun, allowing the ball gun to be redirected at a new target location. In alternative embodiments of the invention, a microphone disposed adjacent the muzzle of the ball gun and an optical detector are respectively used to sense when a ball has been fired. | 1 |
FIELD OF THE INVENTION
The present invention relates to a process for neutralizing petroleum acids.
BACKGROUND OF THE INVENTION
Whole crudes with high organic acid content such as those containing naphthenic acids are corrosive to the equipment used to extract, transport and process the crude.
Efforts to minimize naphthenic acid corrosion have included a number of approaches. U.S. Pat. No. 5,182,013 refers to such recognized approaches as blending of higher naphthenic acid content oil with low naphthenic acid content oil. Additionally, a variety of attempts have been made to address the problem by using corrosion inhibitors for the metal surfaces of equipment exposed to the acids, or by neutralizing and removing the acids from the oil. Examples of these technologies include treatment of metal surfaces with corrosion inhibitors such as polysulfides (U.S. Pat. No. 5,182,013) or oil soluble reaction products of an alkynediol and a polyalkene polyamine (U.S. Pat. No. 4,647,366), or by treatment of a liquid hydrocarbon with a dilute aqueous alkaline solution, specifically dilute aqueous NaOH or KOH (U.S. Pat. No. 4,199,440). U.S. Pat. No. 4,199,440 notes, however, that a problem arises with the use of aqueous solutions that contain higher concentrations of base. These solutions form emulsions with the oil, necessitating use of only dilute aqueous base solutions. U.S. Pat. No. 4,300,995 discloses the treatment of carbonous material particularly coal and its products, heavy oils, vacuum gas oil petroleum resids having acidic functionalities with a dilute quaternary base such as tetramethylammonium hydroxide in a liquid (alcohol or water). IR data of the untreated crude show a peak at 3300-3600 cm -1 corresponding to a phenolic hydroxide (Example 6). The C 13 NMR spectrum of O-methylated crude shows a signal at 55 ppm corresponding to a methyl phenoxide (Examples 3 and 4). This patent was aimed at improving yields and physical characteristics of the products and did not address the question of acidity reduction.
While these processes have achieved varying degrees of success there is a continuing need to develop more efficient methods for treating these acidic crudes.
SUMMARY OF THE INVENTION
A process for decreasing the acidity of an acidic crude oil comprising: contacting an organic acid containing crude oil at an elevated temperature with an effective amount of tetraalkylammonium hydroxide, preferably solid, to produce a treated crude oil having a reduced acidity.
The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed.
DETAILED DESCRIPTION OF THE INVENTION
Some crude oils contain organic acids that contribute to corrosion or fouling of refinery equipment and that are difficult to separate from the processed oil. These organic acids generally fall within the category of naphthenic and other organic acids. Naphthenic acids alone or in combination with other organic acids can cause corrosion at temperatures ranging from about 65° C. (150° F.) to 420° C. (790° F.).
The crudes that may be used are any naphthenic acid-containing crude oils that are liquid or liquefiable at the temperatures at which the present invention is carried out. As used herein the term whole crudes means unrefined, non-distilled crudes.
Applicants have discovered that acidic crude oils, i.e., those containing naphthenic acids, may be treated by contacting the crude with an effective amount of tetraalkylammonium hydroxide, preferably tetramethylammonium hydroxide, and preferably in solid form, to produce a treated or final crude having a reduced or essential absence of acidity. The naphthenic acids may be present either alone or in combination with other organic acids, such as phenols. The acidic crudes are preferably whole crudes. However, acidic fractions of whole crudes also may be treated. An additional benefit of the treatment process is the absence or substantial absence of emulsion formation. Emulsion formation is undesirable and a particular problem that is encountered during treatment of naphthenic acid-containing crudes with aqueous bases. The formation of a crude oil-aqueous emulsion tends to interfere with the efficient separation of the whole crude oil and water phases and thus with recovery of the whole crude oil. Thus, in addition to their corrosivity such acids must be removed from the crude oil due to their tendency to encourage emulsion formation during processing. The process of the present invention when carried out in the essential absence of added solvent (i.e., water or alcohol) for the tetraalkylammonium hydroxide, reduces the volume of liquid, particularly solvent, that must be handled.
The contacting is typically carried out at an elevated temperature sufficient to reflux the solution. Typically, this is from about 50° C. to 350° C., preferably 100° C. to 170° C., more preferably 120° to 150° C. Desirably this results in esterification of the naphthenic acids in the crude oil.
Tetraalkylammonium hydroxides may be purchased commercially or synthesized using known procedures. Tetramethylammonium hydroxide, for example, typically occurs in solid form as crystals of the pentahydrate, represented by the formula (CH 3 ) 4 NOH.5H 2 O. The tetraalkylammonium hydroxide is added to the acidic crude in an amount effective to produce a neutralized final crude oil. Typically, it is added in a molar ratio of tetraalkylammonium hydroxide to total acid of from 1:1 to about 10:1, preferably of from 2:1 to 1:1. The addition of smaller amounts of tetraalkylammonium hydroxide may result in an incomplete neutralization of the starting crude. Each alkyl chain typically contains up to about four carbon atoms.
Reaction times depend on the nature of the crude to be treated, its acid content, and the amount and type of tetraalkylammonium hydroxide added, but typically may be carried out for from about 1 hour to about 20 hours to produce a product having a decrease in naphthenic acid and other acid content.
The concentration of acid in the crude oil is typically expressed as an acid neutralization number or acid number, which is the number of milligrams of KOH required to neutralize the acidity of one gram of oil. Included are acidic crudes wherein the oil has a neutralization number of 0.5 to 10 mg KOH/g. It may be determined according to ASTM D-664. Typically, the decrease in acid content may be determined by a decrease in the neutralization number or in the intensity of the carboxyl band in the infrared spectrum at about 1708 cm -1 . Whole crude oils with acid numbers of about 1.0 and lower are considered to be of moderate to low corrosivity. Crudes with acid numbers greater than 1.5 are considered corrosive. Acidic crudes having free carboxyl groups may be effectively treated using the process of the present invention.
While not wishing to be bound by any theory it is believed that the reaction takes place by neutralization of the acid groups on the naphthenic acid to produce an aliphatic ester as follows: ##STR1##
Regeneration of the tetraalkylammonium hydroxide, e.g., tetramethyl-ammonium hydroxide, can be carded out in a number of ways, ideally:
(CH.sub.3).sub.3 N+CH.sub.3 OH→(CH.sub.3).sub.4 NOH
Whole crude oils are very complex mixtures in which a large number of competing reactions may occur. Unexpectedly, the reaction occurs completely although the acid is dilute in comparison to the large excess of crude and other reactive species typically present.
The process of the present invention has utility in processes in which inhibiting or controlling liquid phase corrosion, e.g., of metal surfaces, is desired. More generally, the present invention may be used in applications in which a reduction in the acidity, typically, as evidenced by a decrease in the neutralization number of the acidic whole crude or a decrease in intensity of the carboxyl band in the infrared spectrum at about 1708 cm -1 of the treated (neutralized) crude, would be beneficial and in which oil-aqueous emulsion formation and large solvent volumes are not desirable. The present invention also provides a method for controlling emulsion formation in acidic crudes, by treating a major contributing component of such emulsions, naphthenic and similar organic acids, and by reducing the attendant handling and processing problems.
The present invention may be demonstrated with reference to the following non-limiting examples.
EXAMPLE 1
The reaction apparatus was a flask equipped with a stirrer, Dean-Stark trap and reflux condenser, immersed in an oil bath. 50 g of San Juaquim Valley whole crude, having a neutralization number of 4.17 mg KOH/g, and 6.5 g of tetramethylammonium hydroxide pentahydrate were added to the flask. The oil bath temperature was gradually increased until water began to collect in the Dean-Stark trap. The temperature of the oil bath was brought to 140° C. and held for 16 hours. After cooling, the flask content was analyzed and found to have a neutralization number of 0.12 mg KOH/g.
EXAMPLE 2
The reaction apparatus was the same as in Example 1. 50 g of San Juaquim Valley acid whole crude, with neutralization number 4.17 mg KOH/g and 0.68 g of tetramethylammonium hydroxide pentahydrate were put into the flask. The oil bath temperature was gradually increased, until no more water collected in the Dean-Stark trap. The final temperature was 140° C. After cooling, the flask content had a neutralization number of 0.55 mg KOH/g.
The infrared spectrum of untreated San Juaquim Valley crude showed a band at 1708 cm -1 , corresponding to free carboxyl groups. After treatment with tetramethylammonium hydroxide, the band at 1708 cm -1 became less intense and a new band appeared at 1742 cm -1 , indicating presence of ester groups.
EXAMPLE 3
The reaction apparatus was the same as in Example 1. 50 g of Bolobo 2/4 crude, with a neutralization number of 8.2 mg KOH/g and 1.8 g of a 38 weight % solution of tetramethylammonium hydroxide in water were put into the flask. The oil bath temperature was gradually increased until no more water condensed in the Dean-Stark trap. After cooling, the flask content was analyzed and found to have a neutralization number of 0.21 mg KOH/g. | The invention relates to a process for treating naphthenic acid--containing whole crudes or fractions thereof to reduce or eliminate their acidity by contacting the acidic whole crude or fraction at a temperature of from about 50° C. to 350° C. with a neutralizing amount of tetraalkylammonium hydroxide, preferably tetramethyl-ammonium hydroxide. The process has the additional benefits of reducing materials handling problems associated with treating oils using liquid solvents and in reducing emulsion formation. | 2 |
BACKGROUND OF THE INVENTION
The invention relates to a guide bar bearing arrangement for warp knitting machines comprising a guide bar bracket and guide bar frame connected together through a connecting arrangement and, in particular, to a connecting arrangement having at least one linear bearing bolt and a bearing displaceable with respect thereto, as well as, a guide bar which is attached to the guide bar frame.
An arrangement of this type is known from German Utility Model DE-GM 1857100. In this arrangement the guide bars are carried by the frame in which the linear bearing bolts are fastened. The linear bearing bolts are located in roller bearing sleeves in the guide bar bracket and are axially displaceable therein. It has been shown in practice that in this arrangement, substantial frictional losses occur in the drive means. Specifically, losses occur at the roller and the cam which transmit the axial movement required by the fabric design features, to the guides themselves.
It is therefore the purpose of the present invention to provide for a guide bar a bearing arrangement which operates with a lower level of frictional loss when interacting with the parts to be moved.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a guide arrangement for a warp knitting machine. This guide arrangement includes a guide bar bracket and a guide bar frame. A guide bar is attached to the guide bar frame. Also included is a connecting arrangement connecting between the guide bar frame and the guide bar bracket. The connecting arrangement has at least one linear bearing bolt attached to the guide bar bracket. The connecting arrangement also has a bearing slidable relative to the linear bearing bolt. This bearing is attached to the guide bar frame.
Accordingly an improved guide bar bearing arrangement is achieved when the linear bearing bolt is attached to the guide bar bracket and the bearing itself is attached to the guide bar frame. This mode of construction gives rise to a substantial savings in weight in the moving parts. This, in turn, reduces the mass which must be accelerated. Also the drive means is subject to less stress.
Furthermore, the return spring for returning the guide bar can be reduced in size which thus, similarly reduces the power required for the return action. Utilizing a smaller return spring reduces the forces acting upon the drive means.
The bolt, which because of the carrying task ascribed to it, is generally speaking constructed as a rather massive part, need no longer move in the new arrangement. The builder of the equipment is thus provided with a range of choices in selecting the size of the bolts. In one embodiment the bolts can be decreased in size since they no longer need to carry their own weight. This can lead to savings in construction costs. Equally, the bolts can be made larger than heretofore because their weight, relative to the mass of the guide bar to be moved is no longer relevant. This in turn leads to a more solid fixing of the guide bar frame.
Generally speaking a guide bar bracket can be constructed in a distortion free manner more readily than the guide bar frame. When the bolts are rigidly fixed in the guide bar bracket there is provided a greater security against distortion of the bearings with respect to each other, which previously caused misalignment of the bolts from their normally parallel relation with each other.
The savings in weight also permits a higher working speed of the equipment without an increase in frictional losses. A portion of the weight saving can be utilized to make the guide bar more stable so that it no longer vibrates too readily. When the guide bar is more stable, it is possible to reduce the number of guide bar frames which, in turn, leads to an additional savings in weight.
Furthermore, the arrangement in accordance with the present invention requires a smaller return spring which again results in a cost savings.
In a particularly preferred embodiment the center of gravity of the guide bar frame is located in a region perpendicularly below the bearing, this results in a very small moment of rotation being exercised upon the bearing. Thus, it is no longer so necessary to guard the bearing against binding due to misalignment.
It has been found desirable that the guide bar frame comprises a fastening flange for the guide bar whose width is between 11/2 and 21/2 times (preferably 2 times) the width of the guide bar frame. Such an arrangement permits the weight of the guide bar frame to be reduced further. The marginal loss of stability of the guide bar bearing can be compensated for by constructing the guide bar in a somewhat more rigid manner.
It is further desirable that the fastening flange be symmetrical to the central axis of the guide bar frame. This geometry serves to reduce the turning moment on the bearing as much as possible.
It is further advantageous that the guide bar frames are provided in the area of their upper and lower ends with a pair of mutually parallel sleeves, operating as bearings. Since the guide bar frames need only slide back and forth on the guide bolts, they can be slighter than when they must support the bolts themselves. The demands on the guide bar frames are much greater when they must hold the slide bolts fixed and parallel to each other, that is to say, secured against distortion.
It is preferred that the sleeves are connected to each other by means of ribs. This arrangement leads to a further saving in weight in contrast to a massive solid construction form for the guide bar frames. It is particularly advantageous to provide the guide bar frames in H-shaped cross sections with two border ribs and one transverse rib. This gives rise to a greater degree of rigidity while utilizing a smaller amount of material.
It is further preferred that the width of the border ribs should correspond to the outer cross-section of the sleeve. (The term breath is not intended to mean the height of the border ribs, but rather its dimension in a plane perpendicular to the axis of the bolt.) This provides the guide bar frame with a compact form which has been found to be useful in the retention of the bearing and is also advantageous in construction.
It is also preferred that the breadth of the transverse bar, that is to say, the dimension in the direction of the bolt axis, corresponds to the length of the sleeve. The guide bar frame is thus provided with a compact form which does not interfere on the one hand, with the axial movement possibilities of the guide bar frame and on the other hand, yields the greatest possible stability.
It is further advantageous that the transverse rib extends beyond the border bars and protrudes outwardly. That is to say, the border bars are not necessarily located at the end of the sleeve but are somewhat displaced towards the middle of the sleeves. This enables a simple upper surface treatment of the face side of the sleeves since only the face surface of the transverse bar need be involved.
It is advantageous that the guide bar frames are forged. This gives rise to a weight savings relative to a cast guide bar frame since, forged materials have a higher rigidity then cost ones.
In a preferred embodiment the height of the guide bars is at least double that of their width, this provides an additional stability in the up and down movement direction.
It is particularly preferred that the guide bar height is 21/2 times the breadth.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments, in accordance with the present invention, when taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a general elevational view of the guide bar arrangement;
FIG. 2 is a detailed view of a portion of FIG. 1;
FIG. 3 is a transverse-section of FIG. 2 taken along line A--A; and
FIG. 4 is a perspective view of a portion of the guide bar bearing arrangement of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, guide bar 1 having guides 18 attached thereto is moveable to and from by means of a guide rod 22. Guide rod 22 is axially reciprocatable to interact with cam 19 mounted in a cam bearing 20. The movement to the left in the drawing occurs upon the action of a protuberance shown in cam 19 upon guide bars 22 through guide rod 22. The return movement, which is shown in the drawing as being directed to the right, occurs by means of spring 21 which is located between the spring connection 23 and the cam bearing 20.
Guide bar 1 is carried by a plurality of guide bar frames 6 each of which is provided with a guide bar bracket 4 so that guide bar 1 is moveable with respect to said guide bar brackets 4. Guide bar brackets 4 are affixed in a non-rotatable fashion to a common shaft 15 which in turn is rotatably mounted in bearing 16. The shaft 15 is rotatable through a predetermined angle by swing lever 17.
In each guide bar bracket 4 there are provided two mutually parallel linear bearing bolts 2 and 7 which are fixed so as to be immovable with respect to each other. Since the guide bar brackets 4 may be constructed in stable ways, the possibility that the linear bearing bolts 2 and 7 lose their mutual parallelism and become distorted with respect to each other is exceedingly small.
Referring to FIGS. 2, 3 and 4, each guide bar frame 6 comprises two hollow cylindrical sleeves 5 and 9 in which linear bearing bolts 2 and 7 are slidably mounted and which form the bearing of the guide bar frame 6.
Basically, all types of bearings which permit an axial movement are permitted, that is to say, slide bearings. In the illustrated case however, ball bearings are preferred in which the balls 26 are provided in ball bearing sleeves 3 and 8. The balls 26 are permanently held in the ball bearing sleeves 3 and 8, all located in the annular space between sleeves 5, 9 and bolts 2, 7. The movement of the ball bearing sleeves 3 and 8 on the linear bearing bolts 2 and 7 are limited on the one side by guide bar bracket 4 and on the other side by split rings 10 and 11 which are lodged in a groove at the end of the linear bearing bolts 2 and 7.
The ball bearing sleeves themselves 3 and 8 move with half the relative speed of guide bar frame 6, with respect to the fixed linear bearing bolts 2 and 7. When the ball bearing sleeves 3 and 8 find themselves in their rightmost position, that is to say, in contact with the split rings 10 and 11, the guide bar frame 6 similarly finds itself in the rightmost setting. Thus the rightmost face of the sleeves 5 and 9 come close to alignment with the face of the ball bearing sleeves 3 and 8. When the ball bearing sleeves 3 and 8 are at their leftmost end position, that is to say, in contact with guide bar bracket 4, the guide bar frames 6 similarly find themselves at the leftmost end of the linear bearing bolts 7. Thus the left face of sleeves 5 and 9 are substantially in alignment with the left face of the ball bearing sleeves 3 and 8.
Thus the ball bearing sleeves 3 and 8 are longer than sleeves 5 and 9 of the guide bar frame 6 and, in fact, preferably by an amount approximately half the distance by which the guide bar is displaced.
Referring to FIGS. 2 and 3, the two sleeves 5 and 9 of the guide bar frame 6 are connected to each other by means of ribs which have an H-shaped transverse section. This H comprises two border ribs 12 and 13 and a transverse rib 14 which is located in the middle of the border ribs 12 and 13 over the entire breadth of the guide bar frame 6, that is to say, over the entire length of sleeves 5 and 9. The border ribs 12 and 13 are not located directly at the face ends of guide bar frame 6 but are displaced somewhat towards the middle, so that treatment of the face surfaces of sleeves 5 and 9 is readily possible without the need for operation upon the longitudinal ribs 12 and 13 in this particular location.
The width of the border ribs 12 and 13 correspond substantially to the external diameter of sleeves 5 and 9. The guide bar frames 6 are thus provided with a compact outer surface since no part extends outwardly. They are thus easily stackable which considerably simplifies storage and handling.
Guide bar frames 6 terminate in the direction of guide bar 1 in a flange 27, which has a breadth of approximately 11/2 to 21/2 times the breadth of guide bar frame 6. It is particularly desirable that this be a two-fold breadth. In the ends of the flange 27 located over the breadth of the guide bar frame, holes are provided through which screws 24 and 25 may be passed in order to secure the guide bar 1 to the guide bar frame 6.
Guide bar 1 should be at least twice as high as it is broad. The breadth is thus the dimension measurable perpendicular to the plane of the drawing of FIG. 2. This provides guide bar 1 with a relatively high rigidity in the direction perpendicular to the axial displacement direction of the guide bar frame, that is to say, in the direction parallel to the longitudinal axis of the guides 18 (FIG. 1).
A movement in this direction during operation, overlays the axial displacement movement and can, with improper dimensioning, readily lead to a through-swing of the guide bars. This is prevented by means of the stability introduced into the guide bar 1.
In order to construct the guide bar 1, frame 6 is fixed to the guide bar by means of screws 24 and 25. Thereafter, guide bar frames 6 are slid on to the linear bearing bolts 2 and 7. Then the split rings 10 and 11 are mounted on the linear bearing bolts 2 and 7 in order to secure the guide bar frames 6 therein. | A guide arrangement for a warp knitting machine includes a guide bar bracket and a guide bar frame. A guide bar is attached to the guide bar frame. Also included is a connecting arrangement connecting between the guide bar frame and the guide bar bracket. The connecting arrangement has at least one linear bearing bolt attached to the guide bar bracket. The connecting arrangement also has a bearing slidable relative to the linear bearing bolt. This bearing is attached to the guide bar frame. | 3 |
This application claims the benefit of U.S. provisional application, Ser. No. 60/124,444 filed on Mar. 15, 1999, in Express Mail Label No. EL287032906US by the same inventor, Howard J. Trickett, entitled DEVICE AND METHOD FOR TRANSPORTING MATERIALS.
BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention pertains to the field of transporting materials and, more particularly, to transporting materials by a fork-lift and push-pull type truck. This invention eliminates the pallets commonly used in the transportation cycle and provides a better and more advantageous pallet.
II. Description of the Related Art
The present invention contemplates a new and improved method and device for transporting materials which is simple in design, effective in use, and overcomes the foregoing difficulties and others while providing better and more advantageous overall results.
The world population is increasing. In fact, the UN Food & Agriculture Organization projects an increase of 5 to 7 billion people over the next 30 years. This is like adding a new China or India every 10 years.
Population increase and economic expansion consumes land for housing and infrastructure. The earth's land and its resources are limited. Science and technology have provided us with the ability to do more while using less of the available land and resources. However, science and technology are limited as to what they can provide. Mother Earth will be stressed to keep up with world population expansion.
Quality of life is inextricably linked to the basics: reproduction, food, housing, packaging and transportation. Technology plays a major role by providing for a better standard of living for the worlds' people. However, responsible business managers must be at the forefront of developing, providing and using environmentally responsible products.
For over sixty years products have been placed on wood pallets and we have used forklifts to load these products into trailers, containers and railcars. In today's world of high technology this equates to farming with a pair of oxen and a shovel plow. Packaging on wooden pallets can no longer be rationalized nor can shipping the product to a customer who throws the wood pallet into a trash receptacle with the pallet ultimately ending up in a landfill. Landfills are being closed and the trees required to make a good quality wood pallet are becoming scarce thus making the wood more expensive. Today's U.S. wood pallet average cost is over eight dollars. Landfill expense pushes the total cost of using a wood pallet to about ten dollars. This cost adds to the packaging, logistics and ultimately to the consumer's cost of the products they purchase.
Data indicates the global market for wood pallets is in excess of one billion units annually. The data does not include remanufactured or reused pallets. This data also indicates that the U.S. uses over five hundred million wood pallets annually. About four hundred and fifteen million (83%) end up in landfills, about eighty million (16%) are recycled/reused and about five million (1%) disposed of as firewood.
One of the challenges being addressed is the depletion of the world forest to manufacture wood pallets which are then disposed into landfills. We will teach how to use commercially and economical feasible replacement products made from recycled material and/or commercially and economical feasible replacement products that can be recycled back into themselves. These products will be used as the material handling system for the 21st century.
The material handling industry is an industry seeking a change, but until now lacked an uncomplicated economical alternative to the wood pallet. The slip sheet disclosed and claimed within U.S. Pat. No. 5,613,447 and co-pending patent application, Ser. No. 08/823,698 (now U.S. Pat. No. 5,881,651) are those unpretentious economical alternatives. The use of such a slip sheet in conjunction with a captive pallet system leads the way to the future of material handling. These two items taken together, finally accomplish what so many have tried for so long to achieve.
A captive pallet system is one where the shipper and receiver use a good quality wood, plastic or metal pallet to handle the product in-house while the product is packaged on a slip sheet.
The unit of product has hereto been pulled by means of a forklift attachment called a push-pull, from the captive pallet at the point of shipment and the slip sheet becomes the article of conveyance to transfer the unit of product from the shipper to the receiver. Thus the captive pallet is kept or “captured” for reuse at the point of shipment.
At the receiving point, the product is pulled from the trailer using a push-pull attachment or a regular fork-lift truck and placed on the purchaser's captive pallet. From that point, it is handled as a normal palletized load using a regular forklift and normal warehouse storage techniques. The shipping/receiving cycle is described in greater detail later in this application.
Both the producer and his customer keep their good quality wood, metal or plastic pallet in-house. The issue of who destroyed or damaged a $50-$200 plastic pallet, who pays for a lost pallets, cost of returning empty pallets and all the associated problems of using inferior quality wood pallets and wood pallets in general are eliminated.
The slip sheet utilized by the present invention is a product which utilizes and creates a market for virgin and/or recycled and/or off- specification polymeric material. The design of the slip sheet corrects the inherent problems of current plastic and fiber slip sheets. To teach the scope of these problems, later herein is a short synopsis of the problems associated with prior known slip sheets.
The disclosed slip sheet allows the material handling industry to adopt it as a shipping medium, currently performed by pallets. The design this slip sheet eliminates the need for a forklift attachment called a push-pull at the shipping location for many products.
The purpose of this invention is to eliminate the need for a push-pull attachment at the receiving end after product has been shipped using the disclosed slip sheet.
There are two major obstacles associated with current slip sheets. One obstacle is the occurrence of inaccessibility of the lip/tab due to crumpling during transit or shifting of the load. The other obstacle is maintenance of the product on the slip sheet in transit.
Additionally, there are related issues with current slip sheets. Product damage and/or spillage caused by the push-pull gripper jaws colliding with the packaged unit in the operators attempt to grasp the deficient lip/tab. Product damage and/or spillage caused by the push-pull gripper jaws colliding with the packaged unit during the push-pull's jaw release and push cycle. Further, cost considerations need to be made because of the need to have a push-pull at both the shipping and receiving points to handle the current slip sheets. Also, the increasing cost of more sophisticated designed push-pull in an attempt to overcome the inadequacy of current slip sheets lip/tab and their resultant cost as a high maintenance item must be considered.
Field interviews verify that slip sheet and push-pulls in general, do not work well and exhibit these shortcomings, preventing slip sheets from enjoying a greater share of the material handling market.
One material handling area that slip sheets have made an impact is in the grocery industry. However it is one thing to shift a few hundred pound palletized unit of potatoes chips or corn flakes back unto the slip sheet and another thing to restack 2500 pounds of 40 or 80 pounds bags of salt that has shifted in transit. It should be noted that with present slip sheet design, it is only necessary that the product shift as little as ⅛ inch and the lip/tab crease will be covered pushing the lip/tab tightly against the floor of the trailer/container/railcar. With certain bagged products, simply settling during transit will cause the footprint of the product to expand covering the creased area, causing it to be pushed tightly against the floor. Obviously, this creates a problem at the receiving end as it is impossible to grasp the tab/lip and the jaws and platens of the push-pull slide over the top of the product, resulting in product damage. It then become incumbent upon the receiver to unload the unit by hand with manual labor called “humping”.
The technique to make the slanted lip disclosed within U.S. Pat. No. 5,881,651, was added to further enhance and ensure the ability of the lip/tab to fold-up and not crumple when units are added in-line. It was this concept that assured good presentation of the lip/tab for the push-pull's jaws to clamp and/or make an accentuated angle so an operator could simply drop the lift trucks push-pull's platens and/or forks and slip under the slip sheet.
By having a compressible convex airfoil-type cross-sectional area to facilitate the grasping of this type lip/tab in conjunction with the front sidewall, several of the needs of a slip sheet were met. Obviously, it was discovered this design also allowed us to employ a conventional lift truck with tapered forks, meeting several of the additional needs of the material handling industry.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is disclosed a new and improved captive pallet and slip sheet combination which overcomes the problems associated with both a wood pallets transport system and a captive pallet transport system.
Further in accordance with the invention, the slip sheet of the present invention is formed from a flat sheet of material having a flat load receiving portion and four side edges. It is within the scope of the present invention to provide a slip sheet of the type disclosed in U.S. Pat. No. 5,881,651. However, it is further within the scope of the present invention to provide a slip sheet having conventional tabs, or having no tabs. Slip sheets having other designs may require the receiver to use push/pull attachments on forklifts.
Further in accordance with the invention, the captive pallet of the present invention comprises a first fork receiving area for reception of the forks of a conventional forklift for use when the captive pallet is moved, whether in a loaded or unloaded state. The captive pallet also provides a second fork receiving area for reception of the forks of a conventional forklift when it is desired to move only the load, either to load onto the captive pallet or remove from the captive pallet. Various embodiments of captive pallets are provided in the present invention, all having the common feature of providing first and second fork receiving areas. When the captive pallet is engaged on a ground surface in position for normal usage, the second fork receiving area is located higher from the ground surface than the first fork receiving area. The first fork receiving area is characterized by the presence of at least one upper barrier member against which the forks abut when the captive pallet is raised off the ground by the action of the associated forklift. The second fork receiving area is characterized by the absence of any upper barrier. The captive pallet further includes a plurality of planar load supporting surfaces adjacent the second fork receiving areas.
Further in accordance with the invention, there is provided a method of transporting materials. The method includes utilization of a captive pallet and slip sheet combination. A captive pallet having a first fork reception area adapted for use with the forks of an associated forklift. The captive pallet further includes a second fork reception area adapted for use with the forks of an associated forklift. An unloaded captive pallet may be properly positioned for reception of a load by placing the forks of an associated forklift into the first fork receiving area, raising the captive pallet from its resting position, transporting the captive pallet to a load receiving area, and lowering the captive pallet to the ground (or loading platform, etc). A slip sheet may then be positioned onto the load supporting surfaces. A load of material may be placed onto the load receiving portion of the slip sheet. The material may be secured to the slip sheet by any means known in the art such as binding, shrink wrapping and the like. The combination of loaded slip sheet and the captive pallet may be transported to another area by utilizing the associated forklift and the first fork receiving areas as discussed above. In order to move only the loaded slip sheet, the forks of the associated forklift are inserted into the second fork receiving areas. Upward movement of the forks cause the forks to abut the underside of the slip sheet and lift it off the captive pallet.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangement of parts. A preferred embodiment of these parts will be described in detail in the specification and illustrated in the accompanying drawings, which form a part of this disclosure and wherein:
FIG. 1 is a side view of a push-pull type truck's forks and push-pull apparatus;
FIG. 2 is a front view of a push-pull type truck's forks and push-pull apparatus;
FIG. 3 is a perspective view of a captive pallet disclosed herein;
FIG. 4 is a side view of the captive pallet of FIG. 3 ;
FIG. 5 is a front view of the captive pallet of FIG. 3 ;
FIG. 6 is a perspective view of an inverted captive pallet;
FIG. 7 shows the nesting of the inverted captive pallets;
FIG. 8 is a perspective view of a slip sheet;
FIG. 9 is a perspective view of a slip sheet of the invention described herein;
FIG. 10 is an enlarged side view showing the compressible tab of the slip tray of FIG. 9 .
FIG. 11 is an exploded view of a captive pallet/slip sheet combination of the present invention;
FIG. 12 is a perspective view of a further embodiment of a captive pallet;
FIG. 13 is an exploded view of another embodiment of a captive pallet/slip sheet combination according to the invention; and,
FIG. 14 is a perspective view of yet another embodiment of a captive pallet.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Push-pulls were originally designed over forty years ago to be used with cardboard and fiberboard slip sheets. The ambition for the slip sheet was to replace a wood pallet and/or pallets in general as the instrument which move products from a shipping location to a receiving location.
Referring now to the drawings, which are for purposes of illustrating a preferred embodiment of the invention only, and not for purposes of limiting the invention, FIGS. 1 and 2 show a push-pull 10 having two forks 12 which have an extreme taper at the end. These forks are also known within the industry as platens. The platens 12 support the weight of the material as it is pulled from the captive pallet.
The push-pull hydraulics extend the attachment jaw 14 to grip a lip/tab 22 (best shown in FIG. 8 ) which extends beyond the footprint or surface loading area 24 of the slip sheet 20 . As the push-pull gripper jaws 14 close, the hydraulic extension 16 retracts and pulls the load that is packaged on the slip sheet 20 from the captive pallet onto the platens 12 . The load is taken to the loading dock and the push-pull hydraulic extension 16 pushes the load into the conveyance vehicle. Next, the hydraulic extension 16 opens the gripper jaws 14 and hydraulically pushes the load from the platens 12 simultaneously as the lift truck backs away from under the load. Thus, the load is deposited on the floor of the trailer or double-stacked onto a similar load.
At the receiving end, the purchaser/receiver, using a push-pull 10 grips the edge of the slip sheet 20 , pulling it onto the platens 12 , carries it to a captive pallet and pushes the load onto a waiting captive pallet. From that point, the material is handled in-house in the same manner as if it had been originally shipped on a conventional wood, plastic, or metal pallet.
In another embodiment, a captive pallet may not be used, and the slip sheet 20 will serve as the support base while the material is stored in-house.
FIGS. 3-5 depict a preferred embodiment of the invention herein. A captive pallet 30 is shown having a front 32 , a rear 34 and sides 36 , 38 . The front 32 and rear 34 of the captive pallet 30 are both able to receive the forks 12 of a fork-lift type truck. The captive pallet 30 shown is preferably rectangular in configuration but also could be square or other shapes and still be within the scope of this invention.
The captive pallet 30 comprises a top 40 and bottom 42 both of which have a centerline 41 , 43 . The centerlines 41 , 43 are taken from the width W of the captive pallet 30 . In its preferred embodiment, the center line 41 of the top 40 and the centerline 43 of the bottom 42 lie along the same vertical plane and in-line with one another. This creates vertical plane 44 formed by centerline 41 of the top 40 and centerline 43 of the bottom 42 .
The top 40 comprises a plurality of members 50 that preferably have an inverted u-shape. The inverted u-shaped members 50 are preferably spaced apart according to the width W of the captive pallet 30 and preferably comprise four (4) rows and four (4) columns. The columns C extend from the front 32 to the rear 34 of the captive pallet 30 . The rows R extend from the side 36 to the other side 38 of the captive pallet 30 . Therefore, in its most preferred embodiment, the captive pallet 30 comprises sixteen (16) inverted u-shaped members 50 . However, alternative arrangements and either eliminating the rows R or columns C are within the scope of this invention.
The inverted unshaped members 50 each have a length L M and a width W M . Preferably, the overall width W is 45 inches (114.3 cm) and the column W C is preferably 6.5 inches (16.51 cm). Therefore, the width of the members W M is 6.25 inches (15.875 cm) and 6.5 inches. The members 50 nearest the sides 36 , 38 are typically 6.25 inches in width, while the two center members are typically 6.5 inches. However, the width W of the captive pallet 30 can vary as well as the width W M of the members, as well as the column width W C .
The preferred embodiment of the inverted u-shaped members 50 are disclosed as having a hollow portion 52 thus creating the u-shape. However, the hollow portion 52 can be eliminated thus leaving the member 50 as solid. Again, in its most preferred embodiment, the center columns 54 of the members 50 have a centerline 56 such that they lie along the same line and in the same plane of their respective later-described dividers 70 . The overall preferred embodiment is such that there is equal distribution of weight over the center 31 of the captive pallet 30 . This is accomplished by having the center columns 54 in their most preferred embodiment, as described above.
Dividers 70 are mounted between the top 40 and bottom 42 of the captive pallet 30 . The dividers 70 join the top 40 and bottom 42 of the captive pallet 30 . The dividers 70 extend from the pallet front 32 and terminate at the pallet rear 34 . The dividers 70 aid in support of the material the captive pallet 30 is supporting. Further, the dividers 70 create the later-described slots 80 . The dividers 70 are preferably rectangular in shape. The dividers 70 are located such that their centerline 72 , which runs from the pallet front 32 to the pallet rear 34 , is parallel with the sides 36 , 38 of the captive pallet 30 . However, having the centerline 72 of the dividers 70 can also be situated such that their centerline is not parallel to the sides 36 , 38 . However, having the centerlines 56 situated such that they are parallel with the sides 36 , 38 allows for the forks 12 to enter within the later-described slots 80 and not be interfered by, or with the dividers 70 . The dividers 70 must have a height H great enough to allow the forks to enter between the top 40 and bottom 42 of the captive pallet 30 . Additionally, the height H must be such that it allows the forks 12 to enter the captive pallet 30 easily and without having to be extremely precise. Preferably, the dividers 70 comprise sixteen (16) equally spaced in rows and columns.
Slots 80 are formed by the top 40 , bottom 42 and the dividers 70 . The slots 80 are located along the front 32 and rear 34 of the captive pallet 30 . In its preferred embodiment, one of the slots 80 is located within the center of the captive pallet 30 such that it shares the same vertical centerline as that of the top 40 and bottom 42 of the captive pallet 30 . Or put another way, the centerline 84 of the center slot 82 is in-line with the centerlines 41 , 43 . Preferably, the captive pallet 30 comprises three (3) slots thereby equalizing the captive pallet 30 .
With reference to FIGS. 6 and 7 , an alternative embodiment of the present invention is disclosed. An inverted captive pallet 90 is shown having a front 92 , rear 94 , sides 96 , 98 , top 100 and base 102 . A plurality of first channels 104 , 106 , 108 , form the base 102 . A plurality of second channels 110 , 112 , 114 , 116 form the top 100 . The first channels 104 , 106 , 108 have a width, centerline and extend from the pallet front 92 to the pallet rear 94 . The first channels 104 , 106 , 108 accept the forks 12 of the truck. Preferably, the first and second channels are rectangular.
The second channels 110 , 116 have a length, width and centerline and are mounted to the first channels 104 , 108 . The centerline 118 of the first channels are perpendicular to the centerlines 120 of the second channels. The second channels 110 can also form, by themselves, the sides 96 , 98 of the inverted captive pallet 90 . The second channels preferably have a plurality of u-shaped openings 122 . The u-shaped openings 122 allow for the insertion of a securing means 130 to underlie a load placed upon the inverted captive pallet 90 . The securing means 130 is typically some sort of a strap, belt or other means to secure the load placed upon the inverted captive pallet 90 .
In its preferred embodiment, the inverted captive pallet 90 comprises three (3) first channels 104 , 106 , 108 and the second channels 110 , 112 , 114 , 116 comprise four (4) each having three (3) u-shaped openings 122 . Each u-shaped opening 122 has a centerline that corresponds with the centerline 120 of the 118 first channels 104 106 , 108 . Put another way, each u-shaped opening 122 is located directly above the first channels 104 106 , 108 such that the centerline of the u-shaped opening and the centerline of the first channel lie along the same vertical plane. Preferably, the ushaped openings each have a width Wo 3.5-8.0 inches, inclusive. Again, in the preferred embodiment, the width Wo of the openings 122 are greater than the width of the first channels 104 , 106 , 108 . As shown within FIG. 7 , this allows for proper stacking of the captive pallets 90 upon themselves. The first channels 104 , 106 , 108 fit within each of the openings 122 , which also allow for proper removal by a fork-lift type truck.
The slip sheet 130 of the present invention has upstanding walls 132 , 133 , 134 , 135 , as well as grasping tab 136 . Folded portions 137 , 138 , 139 and 140 are registered and affixed to the walls within slotted portions 141 as shown. The advantage of the grasping tab 136 from those known in the prior art is the cross-section which has one offset crease to allow for a “spring” action of an elliptical lip 144 . This serves to keep an elliptical lip 144 off of the supporting surface. Additionally, this keeps the elliptical lip 144 from being compressed and/or crushed from material set on top and/or pushed up against its opposite lip 144 . This is accomplished by the off-set crease wherein the length L 144 of the elliptical lip 144 exceeds the length L 142 of the lip 142 . The length L 144 is measured as its perimeter, thus yielding the length L 144 . Thus, the tab 136 has two (2) lips, an elliptical lip 144 having a radius of curvature R, and lip 142 being relatively flat, or having multiple creases to allow for ridged off-set lips, i.e., fiber board. This elliptical lip 144 permits the grasping fingers on a push-pull type lift truck to obtain a better grip.
A method of transporting materials utilizes a slip sheet and captive pallet combination. The slip sheet is typically upon the captive pallet whereby the material to be transported is within the slip sheet. The method comprises placing the material to be transported within the slip sheet from a shipping location. The material within the slip sheet is preferably secured by the above-mentioned securing means. The slip sheet and its material are then removed from the captive pallet by a push-pull or fork-lift type truck. The push-pull type truck typically utilizes its features to grasp the tab portion 136 of the slip sheet 130 to pull the slip sheet from the captive pallet. The captive pallet does not leave the shipping location and it used for incoming slip sheets.
The slip sheet, along with the material contained therein, is placed within a movable carrier such as a tractor-trailer type truck, or other means, and shipped to its receiving location. At the receiving location, the slip sheet is removed from the movable carrier by use of a push-pull or fork-lift type truck similar to the manner described above. The slip sheet is then placed upon a pallet, or captive pallet.
The present invention, is further directed to a new and improved captive pallet and slip sheet combination 150 as shown in FIG. 11 . The slip sheet 154 is formed from a flat sheet of material having a flat load receiving portion 158 and four side edges 160 . It is within the scope of the present invention to provide a slip sheet of the type disclosed in U.S. Pat. No. 5,881,651. However, it is further within the scope of the present invention to provide a slip sheet having conventional tabs, or having no tabs. Slip sheets having these other designs may require the receiver to use push/pull attachments on forklifts.
The captive pallet 164 comprises a first fork receiving area 166 for reception of the forks of a conventional forklift (not shown) for use when the captive pallet 166 is moved, whether in a loaded or unloaded state. The captive pallet 164 also provides a second fork receiving area 170 for reception of the forks of a conventional forklift when it is desired to move the slip sheet 154 with or without a load 174 (shown in phantom lines), either to place it upon the captive pallet 164 or remove it from the captive pallet 164 . Various embodiments of captive pallets 164 A- 164 C are shown in FIGS. 12-14 , all having the common feature of providing first and second fork receiving areas 166 , 170 . When the captive pallet 164 is engaged on a ground surface in position for normal usage, the second fork receiving area 170 is located higher from the ground surface than the first fork receiving area 164 . The first fork receiving area 164 is characterized by the presence of at least one upper barrier member 176 against which the forks abut when the captive pallet 164 is raised off the ground by the action of the associated forklift. The second fork receiving area 170 is characterized by the absence of any upper barrier. The captive pallet 164 further includes a plurality of planar load supporting surfaces 180 adjacent the second fork receiving areas 170 .
With reference to FIG. 11 , a method of transporting materials includes utilization of a captive pallet 164 and slip sheet 154 combination. A captive pallet 164 having a first fork reception area 166 adapted for use with the forks of an associated forklift (not shown). The captive pallet 164 further includes a second fork reception area 170 adapted for use with the forks of an associated forklift. An unloaded captive pallet 164 may be properly positioned for reception of a load by placing the forks of an associated forklift into the first fork receiving area 166 , raising the captive pallet 164 from its resting position, transporting the captive pallet 164 to a load receiving area, and lowering the captive pallet 164 to the ground (or loading platform, etc). A slip sheet 150 may then be positioned onto the load supporting surfaces 180 . A load 174 of material may be placed onto the load receiving portion 158 of the slip sheet 154 . The load 174 may be secured to the slip sheet by any means known in the art such as binding, shrink wrapping and the like. The combination of loaded slip sheet 154 and the captive pallet 164 may be transported to another area by utilizing the associated forklift and the first fork receiving areas 166 as discussed above. In order to move only the loaded slip sheet 154 , the forks of the associated forklift are inserted into the second fork receiving areas 170 . Upward movement of the forks cause the forks to abut the underside of the slip sheet 154 and lift it off the captive pallet 164 .
The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of the specification. It is intended by applicant to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | Disclosed is a method and device for transporting materials from a shipping end to a receiving end. The device is a slip sheet formed from a flat sheet of material having a flat portion with four side edges. One of the side edges has a compressible tab portion that extends outwardly therefrom. The compressible tab portion has an elliptical lip and an upper lip that forms a convex air foil-type cross-sectional area. The compressible tab portion is canted upwardly from a plane defined by the flat portion of the slip sheet. The slip sheet can be used in combination with a captive pallet to transport materials. Further, a method of transporting materials is disclosed whereby the shipping and receiving ends house the captive pallet whereby only the slip sheet is transported by a push-pull or fork-lift type truck. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hydraulic accumulators and more particularly, relates to a compact hydraulic accumulator suitable for use with a power pack of an automatic door actuator of the type as shown in U.S. Pat. No. 3,620,014 which patent is assigned to the same Assignee as the present application.
With the increasing usage of electrically controlled automatic doors for entrances of commercial establishments and the like, it has been a problem to provide a door actuator which is powerful enough to open a relatively heavy door in rapid fashion and then close the door after the traffic has passed through the entrance. This problem is most readily solved by use of an accumulator to store hydraulic fluid under pressure for release as required and particularly there is a need for an accumulator which is reliable and operates with a minimum of service and maintenance difficulties. Because of the relatively high power requirements in these types of applications, it has been necessary to utilize hydraulic systems which employ relatively high pressure and thereby reduce the size of the door operator unit so that it can be hidden from view by mounting in a transom bar or the like above the door entrance. This arrangement results in greater architectural flexibility in the design of entrances and does not require a large, unsightly mechanism as often are common with other types of door operators. In addition, in establishments such as super markets and the like, it is neccessary to provide a rapid door opening cycle to accommodate the large volume of traffic flow and this in turn requires a relatively high power system which is capable of developing high energy during short periods of time to handle the large heavy duty type entrance doors.
2. Description of the Prior Art
In the aforementioned U.S. Pat. No. 3,620,014, therein is illustrated an automatic door actuator employing a power pack which is electrically actuated by an electric control module in turn actuated by the presence of traffic on a switch mat or the like. The control module may also be activated by other traffic presence detectors and when activated to open a door, the control module activates a control valve in the power pack in order to supply high pressure hydraulic fluid to a hydraulic door actuator which rapidly swings the door to an open position. As the actuator opens the door, a return spring is compressed and once the traffic is clear of the entrance, the control spring then returns the door back to a closed position. The hydraulic actuator of such a unit requires a relatively high rate of flow of high pressure fluid to cause the door to swing open rapidly, that is with enough speed to accommodate the high volume traffic rates required. Accordingly, the motor powered hydraulic pump of the power pack must be supplemented with additional hydraulic fluid under pressure available from an accumulator or pressurized reservoir.
Accumulators and reservoirs of this type are commonly pressurized by means of a charge of nitrogen gas acting on one side of a flexible diaphragm or piston to pressurize the hydraulic fluid in a chamber on the adjacent opposite side. Because in theory, the pressure of the nitrogen gas and hydraulic fluid is equal, there are normally few leakage problems during operation of these types of accumulators. However, when an accumulator is shut down, for instance at night time, the nitrogen gas tends to leak past the seals on the pistons and the like and in addition, because the nitrogen charge is usually lost if servicing of the unit is required, servicing is difficult and costly and unskilled maintenance or servicemen cannot be used. In addition, because accumulators of the nitrogen gas type are often located in positions where the temperatures may vary in a wide range, the sealing and gas leakage problems often are acute and greatly amplified and many times when sealing failures occur, it is necessary to return the whole pack unit to the factory for a complete overhaul or rebuilding job by skilled personnel to insure continued operation. In the particular entrance door application as shown in the aforementioned U.S. Patent, an electric switch for controlling the pump motor of the system is positioned in the nitrogen filled chamber, and replacement of the switch is often difficult, In addition, sealing around the electrical leads, where the leads pass out of the gas chamber is another area where leakage of nitrogen may occur.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a new and improved hydraulic accumulator of the character described and more particularly, a hydraulic accumulator or a design especially adapted for use in a power pack like that shown in the aforementioned U.S. patent.
Another object of the present invention is to provide a new and improved hydraulic accumulator employing a plurality of coil springs in a cylindrical array and eliminating the need for pressurized nitrogen gas.
Another object of the present invention is to provide a new and improved hydraulic accumulator which requires fewer precision parts, a simpler assembly procedure, has an indefinite shelf life, better operating pressure stability and which is more easily repairable in the field by relatively unskilled personnel, yet relatively small in size, relatively low in cost in comparison to a nitrogen gas accumulator, and operationally reliable.
Another object of the present invention is to provide a new and improved hydraulic accumulator of the character described which provides long trouble-free operation in comparison with a nitrogen gas type and which has a much lower maintenance and repair cost, and fewer requirements for servicing.
Moreover, another object of the present invention is to provide a new and improved hydraulic accumulator which does not require as high a skill level for maintenance and periodic adjustment as does a nitrogen gas type accumulator.
Still another object of the present invention is to provide a new and improved hydraulic accumulator which can be installed in a door actuator of the type shown in the aforementioned U.S. Patent in place of a nitrogen gas filled accumulator with few, if any, changes being required.
SUMMARY OF THE INVENTION
The foregoing and other objects and advantages of the present invention are accomplished in an illustrated embodiment, by way of example and not limitation, comprising a hydraulic accumulator for holding and supplying a volume of hydraulic fluid under pressure. The accumulator includes a variable volume, fluid pressure chamber having a piston member and a cylinder member. A plurality of coil springs are mounted in a cylindrical array acting on one of said members for biasing the same toward the other member to continuously tend to minimize the volume of the pressure chamber and maintain the needed fluid pressure. A fluid conduit is provided for directing fluid into and out of the chamber and switch means externally of the fluid chamber is mounted for actuation by one of the piston or cylinder members in response to a selected value of volume change so that fluid under pressure is automatically supplemented by fluid from an external pump to provide the volume flow rate neeeded for operation of a fluid device such as a door actuator.
BRIEF DESCRIPTION OF THE DRAWINGS
For better understanding of the present invention, reference should be had to the following detailed description taken in conjunction with the drawings in which:
FIG. 1 is a longitudinal cross-sectional view of a new and improved hydraulic accumulator constructed in accordance with the features of the present invention;
FIG. 2 is a transverse cross-sectional view taken substantially along lines 2--2 of FIG. 1;
FIG. 3 is a fragmentary, elevational view looking in the direction of the arrows 3--3 of FIG. 2;
FIG. 4 is a fragmentary, elevational view looking in the direction of the arrows 4--4 of FIG. 2;
FIG. 5 is a fragmentary, elevational view looking in the direction of the arrows 5--5 of FIG. 2;
FIG. 6 is a transverse, cross-sectional view taken substantially along lines 6--6 of FIG. 1;
FIG. 7 is a transverse, cross-sectional view taken substantially along lines 7--7 of FIG. 1;
FIG. 8 is a transverse, cross-sectional view taken substantially along lines 8--8 of FIG. 1;
FIG. 9 is an elevational view looking in the direction of the arrows 9--9 of FIG. 8; and
FIG. 10 is a fragmentary, elevational view looking in the direction of the arrows 10--10 of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings, therein is illustrated a new and improved hydraulic accumulator constructed in accordance with the features of the present invention and referred to generally by the reference numeral 20. The accumulator 20 is specifically designed as a replacement for a nitrogen gas filled accumulator of the type utilized in a power pack for an automatic door actuator as shown and described in U.S. Pat. No. 3,620,014, which patent is incorporated herein by reference.
The accumulator 20 of the present invention is of relatively small size and is compact so that it may be placed in a transom bar above an entrance door and the accumulator is especially adapted for connection with an integral pump and motor housing 22 of the type similar or identical to that described in the aforementioned U.S. Patent. The accumulator includes a variable volume fluid pressure chamber 24 adapted to contain a supply of hydraulic fluid or the like under suitable operating pressure for use in activating a fluid device such as the door actuator as shown in the aforementioned U.S. patent. The variable volume fluid chamber 24 is formed by a fixed cylindrical piston member 26 which is secured onto a pump block plate 28 by means of a single bolt type fastener 29 having a socket type head seated within an enlarged axial recess provided in an axial bore of the piston member. The fastener 29 is threaded into an aperature 33 formed in the pump block plate and an 0-ring 31 is provided to seal around the fastener between the base of the piston and the abutting surface of the pump block plate.
The fluid chamber changes volume with relative movement between the piston 26 and a cylinder body 30 which is slidably mounted thereon and formed with an axial bore 32 open at an end facing the pump block plate. The bore of the cylinder is slightly larger in diameter than the piston and a sealing ring 34 having an hourglass shaped cross-section is carried in a groove on the piston to seal between the piston and the bore of the cylinder. A pair of piston rings 36 and 38 are mounted in grooves on the piston on opposite sides of the sealing ring 34 to support the cylinder for smooth sliding movement.
The cylinder body 30 is formed with a cylinder head 40 intermediate its ends and a cup indentation or recess 42 is provided adjacent the outer, free end of the cylinder body as shown in FIG. 1. The cylinder includes an outer surface which is generally cylindrical in shape and a plurality of longitudinally extending recesses 44, each of circular cross-section are formed in the cylinder body in a generally cylindrical array in order to accommodate a plurality of pairs of coaxially aligned coil springs 46 and 48 as best shown in FIGS. 1 and 7. The cylindrical spring recesses 44 are spaced equilaterally around the cylinder body and terminate short or the end of the cylinder that faces the pump block plate in a flange 49. This flange transmits the thrust of the coil springs to the body of the sliding cylinder. The opposite ends of each pair of coil springs 46 and 48 bear against a heavy thrust washer 50 which in turn is seated against an inwardly directed annular end flange 52 formed in a hollow extruded casing member or shell 54 having a cylindrical bore 56 dimensioned slightly larger than the cylinder body 30. The thrust washer 50 is formed of strong alloy steel or the like with suitable thickness to withstand the heavy bearing pressures exerted by the pairs of coil springs 46 and 48. The interior bore 56 of the casing 54 is formed by drilling or machining and terminates short of the outer free end of the cylinder body to form the retaining end flange 52 as shown. A precision fit between the bore 56 of the casing 54 and the cylinder body 30 is not required and the only surfaces that require precise machining are the outer cylindrical surfaces of the piston 26 and the inner bore surface 32 on the cylinder body. Because the cylinder is supported for sliding reciprocal movement on the piston by the piston rings 36 and 38 honing or laping of the piston is not needed and the rings provide sufficient alignment of the cylinder and piston to guide the cylinder as it moves back and forth in the outer casing 54.
As best shown in FIG. 7, the casing or shell 54 is preferably formed of an aluminum extrusion and includes a plurality of pairs of equilaterally spaced apart longitudinally extending, external ribs 58, pairs of which define cylindrical bores 59 adapted to receive elongated tie rods 60 having threaded end portions 60a (FIG. 2) engaged within threaded aperatures 61 formed in the pump block plate 28 (FIG. 5). As viewed in FIG. 7, the casing extrusion 54 is also formed with a pair of irregularly cross-sectional external ribs 62 and 64, respectively, having fluid passages 66 and 68 formed therein for supplying and returning hydraulic fluid to and from the actuator of the door operator. The casing or shell extrusion includes rib sections 70 and 72 defining bores 74 and 76 in order to accommodate cap screws 78 (FIG. 1) threaded into these bores for attaching a solenoid block member 80 against an outer end of the casing 54 as shown in FIG. 1.
As best shown in FIG. 7, the interior bore 56 of the extruded casing is larger than the cylinder 30 which slides freely within the bore dependant upon the demands for hydraulic fluid and the biasing force of the coil springs 46 and 48 carried thereby. The casing is secured to the pump block plate 28 with the elongated tie rods 60 and nuts 63 and washers 65 on the outer ends of the tie rods and the inner threaded end portions 60a of the tie rods extend into the threaded aperatures 61 in the pump block as described. Similarly, the solenoid block 80 is secured against the outer end of the casing by the pair of cap screws 78 having threaded shank portions threadedly engaging the bores 74 and 76 of the rib portions 70 and 72 and the washers 79 are provided to better distribute the forces from the heads of the cap screws against the aluminum pump block.
As shown in FIG. 1, 0-rings 90 are provided at opposite ends of the hydraulic supply passage 66 and the return passage 68 in the casing 54 and coaxial supply and return passage 82 and 84, respectively, in the pump block 28 are in direct communication therewith. The 0-rings 90 are mounted in shallow annular recesses formed at opposite ends of the passages in the casing 54 and bear against the faces of the pump block 28 and the solenoid block 80. The pump block is preferrably formed of aluminum plate with a flat face fitting tightly against the end of the casing. The opposite parallel face of the pump block bears against the pump housing 22. As shown in FIGS. 1 and 3, the outer end portion of the passages 82 and 84 is threaded in order to receive a closure plug 85 and the supply passage 82 is in communication with a laterally inwardly extending transverse passage 92 having a threaded portion adjacent the outer end for receiving a closure plug 85 (FIG. 2). The inner end of the passage 92 is in communication with the upper portion of a vertical passage 94 also having a threaded outer end portion for receiving a closure plug 85. The lower end of the vertical passage 94 is in communication with an arcuate slot 96 which is supplied with pressurized hydraulic fluid from a pump mounted in the attached pump and motor housing 22. The passage 94 is in communication with a short, blind end passage 98 which is in coaxial alignment with a passage 100 formed in the piston 26 in communication with the variable volume fluid pressure chamber 24. An 0-ring 101 is mounted in a recess in the piston to seal between the abutting faces of the pump block and the piston around the passages 98 and 100. Because the passage 94 is in direct communication with the variable volume fluid chamber 24 via the passages 98 and 100, and also in communication with the pump through the arcuate passage 96, pressurized fluid may be supplied to the passage 66 for use by an actuator of a door operator from either or both sources of pressurized fluid, namely the chamber 24 of the hydraulic pump in the housing. On demand, pressurized fluid flows in the direction of the arrows "A" (FIGS. 1 and 2) via the passages 100, 98, 96, 94, 92, 82 and 66 into a passage 102 in the solenoid block 80. The solenoid block 80 is also provided with a return passage 104 and the passages 102 and 104 are arranged in coaxial alignment with the passages 66 and 68 respectively, in the housing or casing 54.
The return passage 104 in the solenoid block directs fluid back from a door actuator or the like via the passage 68 in the casing 64 into the passage 84 of the pump block 28. The passage 84 is closed adjacent its outer end by a closure plug 85 (FIG. 2) and at the inner end is in communication with the short passage 106 which in turn is in communication with a vertical passage 108. At the lower end, the passage 108 is in communication with a blind end, return passage 110 which directs the returning fluid back into the reservoir of the pump and motor housing 22. The passages 84, 106 and 108 are closed adjacent their outer ends by closure plugs 85.
The pressurized fluid and the returning fluid moving to and from the solenoid block 80 is directed via flexible hydraulic hoses (not shown) which are connected to the door actuator and these hoses in turn, are connected to the accumulator system by means of quick disconnect fittings 112 (FIG. 1) which have threaded upper end portions engaged within threaded passages 114 and 116 in the pump block 80 as shown in FIGS. 8 and 10. The return passage 116 is in direct communication with the passage 104 (FIGS. 8 and 10). The supply passage 114 is in communication with passage 118 extending from an enlarged, central, valve bore section 120.
The lower portion of the bore section 120 is threaded in order to receive a threaded upper end portion of an electrically controlled solenoid valve 122. When activated, the solenoid valve 122 directs a flow of pressurized fluid from the chamber 24 of the accumulator 20 or the pump in the housing 22 into the door actuator and when the actuation is completed, the solenoid valve then shuts off the flow of fluid. Pressurized fluid is supplied to the solenoid valve bore 120 via a passage 124 in communication with the central valve bore 120 approximately at mid-level as shown in FIG. 8. When the solenoid valve 122 is opened, this pressurized fluid is then directed outwardly via a passage 118 into the upper end of the supply passage 114 (FIGS. 8 and 10). Any leakage of high pressure fluid from the upper end of the valve bore 120, is directed back to the return system through a passage 126 in communication with the upper end of the passage 116 and the passage 104. Suitable closure plugs 127 are provided at the outer end portions of the passages 118, 124 and 126 (FIG. 10).
The moving cylinder 30 is adapted to control the operation of the pump in the pump and motor housing 22 and for this purpose, the accumulator 20 includes a bracket 128 at the outer end of the casing 64 for supporting a microswitch 130 (as shown in FIG. 1). The microswitch 130 includes a pivoting operator having a roller 132 adjacent the outer end adapted to engage the frustroconical tapered surface of the recess 42 on the outer end of the cylinder member 30.
On operation of the valve 122 whenever the switch mat or other traffic presence detector electronic system senses the presence of a person wishing to pass through the entrance, pressurized fluid from the accumulator is directed to the door actuator via the supply passages as described. When this occurs, fluid is taken from the chamber 24 and the springs 46 and 48 bias the cylinder to reduce the volume of the fluid chamber 24 and maintain operating pressure on the hydraulic fluid. When the piston member 30 moves far enough towards the right (as shown in FIG. 1), the cam surface of the recess 42 on the outer end of the piston no longer depresses the operator roller 132 on the arm of the microswitch and the switch is thereby activated to start the hydraulic pump in the housing 22. As the pump begins to supply pressurized fluid to the accumulator and the door actuator via the passages 96 and 98, the demand for fluid from the accumulator chamber 24 decreases, and the flow of pressurized fluid to the door actuator of the door operator unit is maintained at a relatively constant pressure. After the demand for fluid is satisfied in the door actuator, continued operation of the pump begins to expand the variable volume accumulator chamber 24 against the force of the biasing springs 46 and 48. As fluid flows into the chamber through the passages 98 and 100, the piston 30 is moved outwardly (to the left as shown in FIG. 1) and this movement continues until the frustroconical cam surface of the recess 42 on the outer end of the cylinder 30 engages and depresses the roller 132 on the microswitch 130 to shut off the hydraulic pump. In this condition, the pressurized fluid in the chamber 24 exerts just enough force against the cylinder 30 to balance the force of the pairs of accumulator springs 46 and 48 and the chamber remains with a supply of pressurized fluid ready for the next cycle of operation when demand for fluid occurs.
From the foregoing it will be seen that the mechanical accumulator system 20 in accordance with the present invention does not require the use of nitrogen gas and accordingly, eliminates the troublesome problems often associated therewith. The pump controlling microswitch 130 does not have to be mounted within a nitrogen filled chamber and there is no problem associated with passage of electrical leads and the like through a gas pressurized chamber wall.
The bias springs 46 and 48 are chosen of a size needed to provide the desired working pressure for the system. The cylinder 30 is supported for reciprocal sliding movement on the fixed piston 26 by the piston rings 36 and 38 and extremely close dimensional tolerances are not required as fluid sealing is accomplished by the sealing ring 34 which provides extremely good sealing during operational as well as dormant periods. Because no gas is required in the accumulator, sealing is considerably less difficult. The machining of the cylinder 30 and the casing 54 need not require great precision and the tolerances for the spring receiving bores 44 on the cylinder and the internal bore 56 of the casing 54 are such that drilling alone is precise enough.
The accumulator thus is considerably less expensive and troublesome than its nitrogen gas filled counterpart and is free of many of the defects heretofore mentioned and problems associated with a containment, sealing and storage of nitrogen gas.
Because the accumulator 20 may be located in severe weather environments where low temperatures and moisture are present, the pump block plate 28 is provided with a blind end bore or passage 134 in order to receive a thermostatically controlled electric heater assembly 136 for insuring that hydraulic fluid in the passage of the accumulator pump block plate 28 and associated components do not become congealed in extremely cold weather.
Although the present invention has been described with reference to a single illustrative embodiment thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention. | A mechanical accumulator for holding and supplying a volume of hydraulic fluid under pressure comprising a variable volume fluid pressure chamber including a piston and a cylinder member, a plurality of coil springs acting on one of said members for biasing the same towards the other of said members to minimize the volume of said chamber and pressurize the fluid therein, a fluid conduit for directing pressurized fluid into and out of said chamber and switch means externally of said chamber and actuated by one of said members in response to the volume changes of said chamber for controlling the operation of a fluid device using fluid from the chamber. | 4 |
This application is a continuation-in part application of the U.S. patent application Ser. No. 12/090,352, which is a National Stage Entry of International Patent Application No. PCT/GB2006/050256, filed Aug. 23, 2006, which claims priority to United Kingdom Patent Application No. 0523927.2, filed Nov. 24, 2005 and United Kingdom Patent Application No. 0606408.3, filed Mar. 30, 2006. The entirety of all of the aforementioned applications is incorporated herein by reference.
FIELD
The present invention relates to gabions and especially to a single box gabion that can be used without a lining material.
BACKGROUND
Gabions are temporary or semi-permanent fortification structures which are used to protect military or civilian installations from weapons assault or from elemental forces, such as flood waters, lava flows, avalanches, slope erosion, soil instability and the like.
WO-A-90/12160 discloses wire mesh cage structures useful as gabions. The cage structure is made up of pivotally interconnected open mesh work frames which are connected together under factory conditions so that the cage can fold concertina-wise to take a flattened form for transportation to site, where it can be erected to take an open multi-compartmental form for filling with a suitable fill material, such as sand, soil, earth or rocks.
WO-A-00/40810 also concerns a multi-compartmental gabion which folds concertina-wise for transportation, and which comprises side walls extending along the length of the multi-compartmental gabion, the side walls being connected at spaced intervals along the length of the gabion by partition walls which are formed from two releasably connected sections, which after use of the gabion can be released and the gabion unzipped for recovery purposes.
Existing gabions have certain disadvantages with respect to construction and longevity. For example, such gabions frequently comprise a wire mesh cage structure lined with a geotextile material, the lining adding to the cost and complexity of the gabion structure, and constituting a significant limitation on the functionality of the gabion after deployment over a long period of time. Particularly in harsh environmental conditions (intense sunlight, wind, rain, snow, sand or salt spray, or a combination of any two or more of these), the geotextile material tends to degrade and this can weaken the functionality of the gabion by, for example, the occurrence of rips, tears or holes in the liner, through which the gabion fill material can fall.
Accordingly, there is a need for an improved gabion. There is also a need for improved multi-compartmental and single box gabions with the adaptability to form larger structures such as modular walls.
SUMMARY
One aspect of the present invention relates to a single box gabion comprising a plurality of interconnected side walls, each side wall comprising at least one substantially closed side wall element panel, wherein each substantially closed side wall element panel is manufactured of a rigid sheet material, wherein pivotal connections are provided between neighbouring side wall element panels allowing the gabion to fold for storage or transport, wherein the substantially closed side wall element panel is provided with means for receiving a hinge member for the purpose of connecting the substantially closed side wall element panel pivotally to a neighbouring side wall element panel, wherein the means for receiving a hinge member comprises one or more apertures in the panel and means for covering or blocking the one or more apertures to prevent or hinder a gabion fill material from escaping through said one or more apertures.
In one embodiment, the substantially closed side wall element panel acts in use of the gabion to prevent a gabion fill material from falling through the side wall.
In a related embodiment, the action of the substantially closed side wall element panel is effective without the aid of a gabion lining material.
In another embodiment, the rigid sheet material has a rigidity that is sufficient to prevent excessive bulging of the side wall element panel when the gabion is filled with a fill material.
In another embodiment, the hinge receiving means are provided on a region of the closed panel of greater thickness than an adjacent region of the panel.
In a related embodiment, the relatively greater thickness of the hinge receiving means section of the panel helps to prevent tearing of the panel by the hinge member in use of the gabion when the side walls of the gabion act to restrain the gabion fill material.
In a related embodiment, the region of the closed panel of relatively greater thickness is provided at or in the region of an interconnection edge of the closed panel.
In a related embodiment, the region of relatively greater thickness is an elongate panel region alongside or at the interconnection edge.
In a related embodiment, the elongate panel section of relatively greater thickness is provided by a folded over edge section of the substantially closed panel.
In a related embodiment, the corners of the panel at either or both ends of the edge being folded are removable so that they can be removed prior to folding in order to facilitate the folding over of the panel under factory conditions.
In another embodiment, the single box gabion further comprises a top panel that functions as a lid of the single box gabion.
In a related embodiment, the top panel is a substantially closed panel.
In another embodiment, the means for covering the one or more apertures to prevent or hinder a gabion fill material from escaping through said one or more apertures is selected from cover strips, cover sheets, cover tapes, cover bands, cover ribbons, cover plates, cover coatings, cover layers, cover tabs, covering adhesives and covering gels, doughs, and putties.
In another embodiment, the means for blocking the one or more apertures to prevent or hinder a gabion fill material from escaping through said one or more apertures is selected from blocking strips, blocking sheets, blocking tapes, blocking bands, blocking ribbons, blocking plates, blocking coatings, blocking layers, blocking tabs, blocking adhesives and blocking gels, doughs, and putties.
In another embodiment, the single box gabion further comprises coupling means to couple to another single box gabion.
In another embodiment, the pivotal connection between neighbouring side wall element panels is achieved by providing a coil member helically threaded through a plurality of apertures along the interconnecting edges of the neighbouring side wall element panels
In another embodiment, each substantially closed panel of the single box gabion has releasable interconnections which when released allow the side wall element panels to open with respect to the gabion to allow access from the side of the gabion to any contents of the gabion compartments.
Another aspect of the present invention relates to a modular gabion structure, comprising a plurality of the single box gabions described above.
Another aspect of the present invention relates to a method for deploying the foldable single box gabion described above, comprising transporting a folded gabion to a deployment site, unfolding the gabion and filling the gabion with a fill material.
In a related embodiment, the fill material is selected from sand, earth, soil, stones, rocks, rubble, concrete, debris, snow, ice and combinations of two or more thereof.
In a related embodiment, the method further comprises coupling the unfolded single box gabion to another unfolded single box gabion.
BRIEF DESCRIPTION OF THE FIGURES
The accompanying drawings illustrate one or more embodiments of the invention and, together with the written description, serve to explain the principles of the invention. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment.
The invention will now be more particularly described with reference to the following drawings, in which:
FIG. 1A shows a perspective view of a single box gabion with six side wall panels in accordance with the invention; FIG. 1B shows a perspective view of a single box gabion with four side wall panels in accordance with the invention; FIG. 1C shows a single box gabion with a top panel in accordance with the invention;
FIG. 2 shows a single box gabion filled with a gabion fill material;
FIG. 3A shows a perspective view of a modular gabion structure formed with a plurality of single box gabions interconnected through pivotal connections in accordance with the invention; FIG. 3B show the two single box gabions interconnected with coupling means; FIG. 3C shows another modular gabion structure.
FIG. 4 shows in close-up perspective view the pivotal connection between neighbouring side wall element panels of the single box gabion;
FIG. 5 shows in close-up perspective view the optional openable pivotal connection between neighbouring side wall element panels of the modular gabion of FIG. 1 , 2 or 3 , before the releasable locking member is installed;
FIG. 6 shows in close-up perspective view the openable pivotal connections were made between the components of the FIG. 5 drawing.
FIG. 7 shows a close-up of a hinged connection of a single box gabion according to the invention;
FIG. 8 shows a close-up of a hinged connection of a single box gabion according to the invention under load;
FIG. 9 shows a close-up of a hinged connection of a gabion according to the invention being broken;
FIGS. 10 to 15 show different partial cross-sections through edges of the walls;
FIGS. 16 to 19 show different partial cross-sections through edges of the walls; and
FIG. 20 shows a side view of a wall of the single box gabion.
DETAILED DESCRIPTION
According to the present invention there is provided a single box gabion comprising side walls connected together to form an enclosed compartment, the side walls comprising at least one substantially closed side wall element panel, wherein the or each substantially closed side wall element is manufactured of a relatively rigid sheet material.
In certain embodiments, the single box gabion further comprise a top panel that serves as a lid of the gabion. In other embodiments, the top panel are substantially closed panels.
In certain embodiments, the single box gabion has a hexagonal compartment with six side walls. The hexagonal compartment optionally contains two larger elongated side walls on opposite sides, which folds inwardly in a manner so that the width of the flattened gabion is substantially the same as the width of the larger elongated side walls. Alternatively, the single box gabion can fold outwardly so that the width of the flattened gabion is larger than the width of elongated side wall, but the flattened gabion will be more compact in its length with this means of folding. The former manner is generally preferable as the resulting folded gabion will have a relatively smaller cross-sectional surface area in a plane orthogonal to the central longitudinal axis of the gabion.
In other embodiments, the single box gabion has a square or rectangle compartment with four side walls.
The substantially closed panel acts in use of the gabion to prevent a gabion fill material (sand, earth, soil, stones or fines, for example) from falling through the side wall without the aid of a gabion lining material.
Preferably, the rigidity of the material is sufficient to prevent excessive bulging of the side wall element panel when the gabion is filled with a fill material.
Other desirable characteristics of the sheet material include, either alone or in combination:
Durability
Toughness
Tear resistance
Scratch and erosion resistance
Corrosion resistance
Thermal stability
Ultraviolet stability
Low density
Low cost
Recyclability
Suitable materials include steel, aluminium, titanium, other metals, alloys, plastics or certain natural materials, or combinations of two or more thereof. Where a metal is used, it is preferably either treated for corrosion resistance, e.g. by galvanisation and/or painting or is inherently corrosion resistant, e.g. a stainless steel.
Where the sheet material is a plastics material it may be polyethylene (PE), polypropylene (PP) or a composite such as glass fibre reinforced polymer (GFRP). The molecular weight of the chosen plastic can be selected to suit the application (e.g. LDPE, HDPE, LDPP, HDPP). Where plastics are used, they are preferably ultraviolet stabilised e.g. by the addition of fillers to prevent them becoming discoloured and/or brittle upon extended exposure to sunlight.
In certain circumstances, it may be desirable to add coloured fillers to the plastics material to provide a desired aesthetic effect. In one aspect of the invention, more than one colour filler is added to the plastics material and partially blended therewith to create a non-homogeneous coloured/marbled effect. For example; green and brown; white and grey; or yellow and brown colour fillers could be added to provide camouflage for vegetated, snowy or dessert environments, respectively. Because such colours are integral with the sheet material (i.e. not a surface decoration), they are less susceptible to removal by erosion (e.g. by sand in a sandstorm).
It is desirable to make the sheet material as thin as possible to reduce the folded volume of the gabion when being stored or transported. A major advantage of using thin-sheet materials is weight saving, which reduces transportation costs and facilitates manual deployment/rearrangement of the gabion.
The substantially closed panel is preferably provided with means for receiving a hinge member for the purpose of connecting the substantially closed panel pivotally to a neighbouring side wall element panel. The hinge receiving means are preferably provided on a region of the closed panel of greater thickness than an adjacent region of the panel. This helps to prevent tearing of the panel by the hinge member in use of the gabion when the side walls of the gabion act to restrain the gabion fill material. The region of the closed panel of relatively greater thickness is preferably provided at or in the region of an interconnection edge of the closed panel. Preferably, the region of relatively greater thickness is an elongate panel region alongside or at the interconnection edge.
In one preferred embodiment of the invention, the pivotal interconnection between connected walls and/or wall sections and/or wall elements is achieved by providing interconnected walls, wall sections and/or wall elements with a row of apertures along or in the region of an interconnection edge thereof and by providing a coil member helically threaded through a plurality of apertures along the interconnection edge. In the case of a straightforward (i.e. non-openable) pivotal connection, a single coil member may be helically threaded through the connection edge apertures of two (or more) neighbouring walls, wall sections and/or wall elements to achieve pivotal interconnection therebetween. Thus, there is provided in accordance with the invention a single box gabion as described wherein the or at least one hinge member comprises a helical coil.
In one example, illustrated by FIG. 7 , the hinged connections 10 comprise helical springs 112 threaded through apertures 114 disposed towards the edges off each wall 116 , 118 , which are manufactured of sheet material. In FIG. 8 , it can be seen that when a force F is applied to the hinged connection 110 , the apertures 114 tend to deform. Upon application to sufficient force, as illustrated in FIG. 9 , the apertures 114 tear-through, thereby disconnecting the hinged connection. One solution is to provide thicker sheet material. Where mesh-type walls are used, this is not necessarily a problem because the wires of the mesh can be thicker for a given overall gabion weight. However, to use sheet metal of the same thickness as the wire diameter could give rise to a prohibitively heavy gabion.
It is therefore desirable, additionally or alternatively to the aforementioned variants, to reinforce the sheet material walls in regions of increased stress.
The elongate panel section of relatively greater thickness may be provided by a folded over edge section of the substantially closed panel. In order to facilitate the folding over of the panel under factory conditions, the corners of the panel at either or both ends of the edge being folded may be removed prior to folding.
If further reinforcement is required, the edge of the sheet material can be folded a number of times or rolled-up.
Additionally or alternatively, additional reinforcing members may be affixed at or near to the edges of the sheet material. Preferably, such reinforcing members are strips that can be welded, glued or otherwise fastened in-situ.
Apertures in the sheet material may pass through one or more layers.
Where the sheet material is provided with reinforcement, the reinforcement may be faired to minimize/prevent snagging with other objects and/or a user's hands.
Fairings may be provided by way of trimming corners, removing burrs and/or providing rounded edges.
Suitably, the substantially closed panel is provided with means for connecting the panel pivotally to a neighbouring panel in the gabion. When such means comprise one or more apertures in the panel, for receiving a hinge member for example, the gabion may be provided with means for covering the one or more apertures to prevent or hinder a gabion fill material from escaping through said one or more apertures. Suitable covering means include cover strips, cover sheets, cover tapes, cover bands, cover ribbons, cover plates, cover coatings, cover layers, cover tabs, covering adhesives and covering gels, doughs, putties and the like. Alternatively, or as well, the one or more apertures may be provided with blocking means for at least partly blocking the egress of fines and other gabion fill materials from the gabion in use thereof. Suitable blocking means include blocking strips, blocking sheets, blocking tapes, blocking bands, blocking ribbons, blocking plates, blocking coatings, blocking layers, blocking tabs, blocking adhesives and blocking gels, doughs, putties and the like.
Other forms of pivotal connection between neighbouring side wall element panels are also contemplated within the scope of the invention—for example an interconnecting edge of a first neighbouring panel may be provided with a protruding portion interconnecting with a corresponding inset portion in the corresponding interconnection edge of a second neighbouring panel. A locking member may extend through the protruding portion and be received in the second neighbouring panel interconnection edge either side of the inset portion to lock the protruding portion into the inset portion in a pivotal fashion.
Alternatively, a locking member may be provided in the interconnection edge of a first neighbouring side wall element panel, extending slightly beyond the interconnection edge at the top and bottom of the panel, and one or more linking members may then secure the locking member to the second neighbouring side wall element panel in the region extending slightly beyond the interconnection edge. Many other forms of pivotal connection may also be suitable in the realisation of the invention.
The single box gabion of the invention may be provided with a plurality of side wall element panels, each comprising a substantially closed panel having releasable interconnections which when released allow the side wall element panels to open with respect to the gabion to allow access from the side of the gabion to any contents of the gabion compartments.
The single box gabion of the invention therefore facilitates post-deployment recovery of the gabion by providing at least one openable side wall section along the peripheral of the gabion. Preferably, a plurality of openable side wall sections are provided. Most preferably, all of the side wall sections of the single box gabion are openable. By “openable” is meant that the pivotal connection between the connected side wall element panels of the side wall section is provided by a hinge member provided on one or both of the connected side wall element panels and by a releasable locking member cooperating with the hinge member releasably to secure the pivotal connection therebetween. In some preferred embodiments of the invention, a first hinge member is provided on a first neighbouring side wall element panel and a second hinge member is provided on a second neighbouring side wall element panel, the releasable locking member cooperating with both the first hinge member and the second hinge member releasably to secure the pivotal connection. Opening of an openable side wall section is achievable by releasing the locking member and pulling apart the resulting unconnected side wall element panels.
Each side wall section may comprise a single side wall element panel, in which case the openable pivotal connection between neighbouring side wall element panels is located between neighbouring side wall sections. In this case the pivotal connection between neighbouring side wall element panels and the partition wall marking the boundary between corresponding neighbouring side wall sections is also openable to allow the first neighbouring side wall element panel to be released from the second neighbouring side wall element panel. Alternatively, each side wall section may comprise a plurality of side wall element panels, in which case the openable pivotal connection may be provided between neighbouring side wall element panels of a given side wall section. However, even when side wall sections comprise a plurality of side wall element panels, openable pivotal connections may be provided between neighbouring side wall sections as well as or instead of between neighbouring side wall element panels of a given side wall section.
In certain embodiments, the single box gabion further contains coupling means on one or more side wall element panels so that two single box gabions can coupled together. In one embodiment, a single box gabion is coupled to another single box gabion by aligning two side wall sections next to each other and providing a coupling means such as a nut and bolt to tie two or more single box gabions together.
The single box gabion of the invention may comprise pivotally interconnected, substantially closed, side wall element panels which are connected together under factory conditions so that the gabion can take a flattened form for transportation to site where it can be erected to take a form in which panels thereof define side walls and an open top through which the compartments of each single box gabion may be filled. Preferably, under factory conditions said panels define side walls and are pivotally interconnected edge to edge and are relatively foldable to lie face to face in the flattened form for transportation to site and can be relatively unfolded to bring the gabion to the erected condition without the requirement for any further connection of the side walls on site.
In preferred embodiments of the invention, the side walls of the single box gabion each comprise a plurality of side panels pivotally connected edge to edge and folded one relative to another. The side walls are pivotally connected thereto, the single box gabion structure being adapted to be erected on site by pulling it apart so that when it is moved from the flattened form to the erected condition the side walls unfold and having a cavity to be filled with a fill material.
Deployment of the single box gabion of the invention is generally effected by transporting the folded gabion to a deployment site, unfolding the gabion and filling each single box compartment of the gabion with a fill material. Generally the fill material will be dictated at least partly by the availability of suitable materials at the deployment site. Suitable fill materials include, but are not limited to, sand, earth, soil, stones, rocks, rubble, concrete, debris, snow, ice and combinations of two or more thereof.
According to the present invention there is also provided a modular gabion structure comprising a plurality of the single box gabions described above. In one embodiment, one or more single box gabions in the modular gabion structure are coupled or interconnected to another single box gabion. In another embodiments, all the single box gabions in the modular structure are interconnected to each other. The modular structure comprised of interconnected single box gabions can each vary in width and/or height to accommodate different configurations and purposes. The adaptability of interconnecting single box gabions has an advantage of protecting structures with corners or irregular shaped and rough terrains, which cannot be achieved by conventional gabions.
Deployment of the modular gabion structure is generally effected by transporting folded single box gabions to a deployment site, unfolding the single box gabions and coupling the unfolded single box gabions to each other, then filling each single box gabions with a fill material. Generally the fill material will be dictated at least partly by the availability of suitable materials at the deployment site. Suitable fill materials include, but are not limited to, sand, earth, soil, stones, rocks, rubble, concrete, debris, snow, ice and combinations of two or more thereof. There are a number of reasons why it could be desirable to open side wall sections of the modular gabion structure. For example, when the deployed modular structured formed from the single box gabions is to be decommissioned, it is often desirable to recover the gabion for environmental or aesthetic reasons, or simply out of consideration for the local population. Recovery of the gabion of the invention is facilitated by opening up all of the openable side wall sections of the gabion, at least partly removing the fill material from the compartments, and removing the gabion from site.
By way of further example, if the deployed modular gabion structure is damaged in use it may be desirable to replace or repair the damaged section of the gabion. Access via the openable side walls of the damaged section facilitates this. Similarly, when it is desired for reasons unconnected with damage to move, alter or replace a gabion section (for example if the position or orientation of the gabion requires alteration), such replacement is again facilitated by the capacity to remove at will fill material from selected single box gabion sections.
Therefore, it is desirable to provide one or more single box gabions in the modular gabion structure with openable side wall sections. Accordingly there is provided in accordance with the invention a single box gabion as described wherein the pivotal connection between the connected side wall element panels of each of the side wall sections, or between each neighbouring side wall section, optionally with the exception of the end side wall sections, is provided by a hinge member provided between the first side wall element panel of a given side wall section and a second neighbouring side wall element panel of the given or a neighbouring side wall section, and a releasable locking member cooperating with the hinge member releasably to secure the pivotal connection. Preferably, a first hinge member is provided on the first side wall element panel and a second hinge member is provided on the second neighbouring side wall element panel, and the releasable locking member cooperates with both first and second hinge members releasably to secure the pivotal connection.
It is also contemplated that openable side wall sections may be provided on two opposed side wall sections of a single box gabion compartment to allow access to the fill material from both sides. Accordingly the invention provides a modular structure gabion as described wherein the pivotal connection between side wall element panels of at least two single box gabions is provided by a hinge member provided between a first side wall element panel of a given side wall section of a first single box gabion and a second side wall element panel of a given side wall section of a second single box gabion, and by a releasable locking member cooperating with the releasable hinge member releasably to secure the pivotal connection.
Also contemplated is that openable side wall sections may be provided alternately on first and second opposed side walls along at least part of the length of the modular gabion structure. In this way when a modular gabion is being recovered, cooperating excavating equipment or personnel can be deployed on opposite sides of the gabion to remove fill material from neighbouring compartments simultaneously or in rapid succession if simultaneous excavation is undesirable for safety or other reasons. Thus, the invention provides a modular gabion as described wherein the connection between the connected side wall element panels of at least a plurality of side wall sections staggered on alternating opposite side walls along at least part of the length of the modular gabion is provided by a hinge member provided between a first side wall element panel of a given side wall section and a second neighbouring side wall element panel of the given, and by a releasable locking member cooperating with the hinge member releasably to secure the pivotal connection. Also contemplated within the scope of the invention is a modular gabion as described wherein the pivotal connection between the connected side wall element panels of at least a plurality of side wall sections staggered on alternating opposite side walls along at least part of the length of the modular gabion is provided by a first hinge member provided on a first side wall element panel of a given side wall section and by a second hinge member on a second side wall element panel of the given side wall section and by a releasable locking member connecting the first hinge member to the second hinge member.
In one preferred embodiment of the invention the openable pivotal interconnection of a modular structure comprising multiple single box gabions between connected side wall element panels is achieved by providing the interconnected side wall element panels with a row of apertures along or in the region of an interconnection edge thereof and by providing a first coil member helically threaded through a plurality of apertures along the interconnection edge of a first side wall element panel, a second coil member helically threaded through a plurality of apertures along the interconnection edge of a second side wall element panel (connected to the first side wall element panel along the interconnection edge) and a releasable locking member threaded through overlapped first and second coil members. Thus, in the case of an openable pivotal connection, a pair of coil members may be helically threaded through the respective opposed connection edge apertures of two neighbouring side wall element panels, and a releasable locking member inserted through the overlapped coils of the opposed pair of coil members. Accordingly, there is provided in accordance with the invention a modular gabion as described wherein at least one openable pivotal connection between neighbouring side wall element panels is provided by the presence of a pair of coil members helically threaded through respective connection edge apertures of neighbouring side wall element panels and by a releasable locking member threaded through the respective coil members when overlapped.
Thus, there is provided in accordance with the invention a modular gabion as described wherein the or at least one hinge member comprises a helical coil.
The releasable locking member may be of any suitable shape or size and may for example comprise an elongate locking pin. The pin may be provided with a gripping protrusion at one end to facilitate manual insertion and/or removal of the locking pin. The gripping protrusion may for example comprise a loop at one end of the locking pin. Accordingly there is provided in accordance with the invention a modular gabion as described wherein at least one locking member comprises an elongate locking pin.
The side walls, side wall sections, side wall element panels preferably comprise one or more panel sections of any suitable material, for example steel, aluminium, titanium, any other suitable metal or alloy, or from a plastics, ceramic or natural material such as timber, sisal, jute, coir or seagrass. Normally, steel is preferred, in which case the steel is preferably treated to prevent or hinder steel erosion during deployment of the gabion. The panel is a substantially closed panel which acts in use of the gabion to contain a gabion fill material without the need for a gabion compartment lining material, such as a geotextile liner. However, the gabion of the invention may be used together with a suitable lining material if necessary. In the case of a closed panel, connection edge apertures where needed will normally be machined or otherwise provided in or in the region of the panel edge.
Referring in more detail to FIG. 1A , there is shown a single box gabion 100 comprising side wall element panels 11 , 12 , 13 , 13 ′, 14 and 14 ′ connected together to form an enclosed compartment 10 . The neighbouring side wall element panels are interconnected through pivotal connections 15 . FIG. 1B shows another single box gabion 100 with four side walls. As shown in FIG. 1C , the single box gabion 100 may further contain a top panel 16 that serves as lid for the gabion.
The side wall panels may be provided with texture, ribbing or other irregularities in order to maintain effective strength of the panel whilst minimising its weight, and/or to provide decorative effect.
Referring to FIG. 2 , a single box gabion 100 is shown filled with a gabion fill material 21 . Fill material 21 may be selected from any suitable available material, as hereinbefore described. Rough earth and stones are shown as the fill material in FIG. 2 . FIG. 2 also shows a cover strip 22 , 22 ′ over the hinged interconnection edges of the gabion.
Referring now to FIG. 3A , there is shown a modular gabion structure 300 formed with a plurality of single box gabion 100 , each comprises side wall element panels 34 , 35 , 312 and 313 . The single box gabions are interconnected to each other by pivotal connections 321 , 322 , 323 and 324 . FIG. 3B shows another embodiment of modular gabion structure 300 in which the single box gabions 100 and 100 ′ contain coupling means 200 that connects the side wall element panel 12 of the single box gabion 100 to the side wall element panel 11 ′ of the neighbouring single box gabion 100 ′. FIG. 3C shows another modular gabion structure 300 formed with a plurality of single box gabions 100 . In this embodiment, the single box gabions 100 may or may not be coupled to each other by pivotal connection or the coupling means.
Referring now to FIG. 4 , there is shown a close-up perspective view of the pivotal connection between neighbouring side wall element panels 13 and 13 ′ This pivotal connection may be between two side wall element panels only. Referring to FIG. 4 , side wall element 13 comprises a substantially closed panel 41 comprising a folded over edge region 42 in which is machined a row of interconnection edge apertures 43 . Prior to folding of folded over edge portion 42 , the corners of side wall element panel 41 at either end of the interconnection edge are removed to facilitate folding. Pivotal connection therebetween is effected by a helical coil 45 which is helically threaded through the interconnection edge apertures of the neighbouring panels. Although not shown in FIG. 4 , loose end 45 of helical coil 44 may be bent round or otherwise prevented from accidentally disengaging with the top most aperture of side wall element 13 , and weakening the pivotal connection by such disengagement.
Referring now to FIG. 5 , there is shown in close-up perspective view the optional openable pivotal connection between neighbouring side wall elements 13 , 13 . In this case, both neighbouring closed panels are provided with helical coil members threaded helically through the interconnection edge apertures thereof. The first hinge member 51 and the second hinge member 52 are thereby provided. Releasable locking member 53 is shown in FIG. 6 connecting the overlapped helical coils. Referring now to FIGS. 10 to 15 , cross-sections through the gabion are shown where the walls 126 are manufactured of sheet metal. As can be seen, a helical spring 112 is threaded through apertures 114 in the side wall 126 .
In FIG. 10 , a single fold 130 is provided to reinforce the edge of the wall 126 . The aperture 114 passes through both thicknesses 132 of the fold 130 .
In FIG. 11 , a double fold 134 is provided and the aperture 114 passes through all three thicknesses 136 of the fold 134 .
In FIG. 12 , a single fold 130 is provided, but the aperture 114 only passes through a single thickness 132 .
In FIG. 13 , a double fold 134 is provided, but the aperture 114 only passes through a single thickness 136 .
In FIGS. 14 and 15 , a reinforcing strip 138 is stuck to the wall 126 using a layer of adhesive 140 . The aperture can either pass through the reinforcing strip 138 , or the wall 126 , respectively.
In FIGS. 16 , 17 and 18 , the aperture only passes through the wall 126 . Strength/reinforcement advantages can nonetheless be attained so long as the spring 112 is pulled in the direction indicated by arrow A. This arrangement has the further advantage that the aperture 114 need only be drilled or punched through one thickness of material, which reduces manufacturing costs and/or complexity.
FIGS. 16 to 19 show partial cross-sections of the gabion where the wall 126 is manufactured of a plastics material. As can be seen, a thicker, reinforced region 142 is relatively easily formed using a suitable moulding technique. In FIGS. 17 to 19 , a reinforcing wire 144 has been co-moulded with the wall 126 to further reinforce the edge thereof.
A further possible variant of the invention sees reinforcing wires or a reinforcing mesh 146 being integrally mounded with the wall 126 as illustrated in FIG. 17 . This feature means that much thinner wall thicknesses can be provided for a given strength requirement.
FIG. 20 shows a side view of a wall panel 126 having an edge reinforcement as illustrated in FIG. 6 . As can be seen, the corners of the fold 130 have been cut away 150 to prevent sharp edges 151 (indicated by a dotted line) protruding above the edge 152 of the wall 126 .
As can also be seen in FIG. 16 , the top and bottom edges 153 of the wall 126 have also been folded over to facilitate manual handling of the gabion and to prevent damage to neighbouring objects (not shown) such as a floor surface.
The above description is for the purpose of teaching the person of ordinary skill in the art how to practice the present invention, and it is not intended to detail all those obvious modifications and variations of it which will become apparent to the skilled worker upon reading the description. It is intended, however, that all such obvious modifications and variations be included within the scope of the present invention, which is defined by the following embodiments. The embodiments are intended to cover the claimed components and steps in any sequence which is effective to meet the objectives there intended, unless the context specifically indicates the contrary. | A single box gabion is disclosed. The gabion comprises interconnected side walls. Each side wall comprises at least one substantially closed side wall element panel that prevents a gabion fill material from falling through the side wall without the aid of a gabion lining material. The single box gabion can be coupled together to form a modular gabion structure to protect military or civilian installations from weapons assault or from elemental forces, such as flood waters, lava flows, avalanches, soil instability, slope erosion and the like. | 4 |
FIELD OF THE INVENTION
The invention relates to a protective device for use for exterior prostheses, where the protective device is dimensionally conformed to the shape and size of the body or adapted to the contours of the anatomy of the person wearing the protective device, respectively.
BACKGROUND OF THE INVENTION
Exterior prostheses in the form of arm and leg prostheses are known in the art. They are made particularly from metals and/or carbon or other plastics and fibre materials. However, these materials do not lend themselves especially well to being worn when showering or pursuing water sports, because water, and particularly salt water, can attack and damage the very valuable, expensive materials of the prosthesis. Therefore, it is known to use “bathing prostheses”. These are made from plastics, but they do not have the advantages of the valuable metal or carbon prostheses, either with regard to wearing comfort or handling, the person who is wearing the bathing prosthesis can take a shower with it on or use it to walk to a body of water for recreation. It can even be worn for brief periods in the water, to cool down. But the disadvantage remains in that it usually must be removed for swimming and left on the bank at the point of entry into the water. In this context, the further problem arises in that in the case of rocky shores or unsupervised beaches, this is often not possible. Moreover, as the person in question removes the prosthesis, his handicap becomes evident to third parties and accordingly draws irritating attention to him. Since the design of such bathing prostheses usually is relatively unsophisticated, the prosthetic-wearing person is also prevented from getting to bodies of water that can only be reached by walking over rocks, stones and paths, because such routes usually do not offer a secure purchase.
Tubes are also known that are made from thin material and may be tightened on one side with a rubber drawstring or similar. In order to be able to adapt these to the anatomical shape of the person wearing the prosthesis or plaster cast, underpressure is created inside the tube. A valve and pumping bulb are provided in the skin of the tube for this purpose or another kind of device for producing an underpressure. Such a solution for sealing casts is especially known from AT 61218 E or from products of the company Dry Corp., LLC under the name Dry Pro™. Alternatively, it is known to use heat to fit it closely to the body of the person wearing the prosthesis or cast in the manner of a shrink tube. In either of these cases, the result is not very appealing. Moreover, if a valve with pumping bulb is provides, the problem arises that the valve may be damaged or opened during use later, and the sealing effect will be lost. In addition, swimming in bodies of water is rendered awkward because of the excessive amount of material. The short service life of these tubes or shrink tubes represents a further problem, since they can become damaged and start to leak very easily. In case of breakdown or malfunction of the valve or damage of the tube, respectively, an excessive amount of water will penetrate into the inner of the tube within a very short time. Moreover, the shrink tube variant can only be used once, and takes a great deal of effort to remove afterwards. This variant is thus a disposable product which is difficult to take off after use.
DE 41 25 635 A1 discloses a cover for a femoral or shank prosthesis and a method for producing the same wherein the cover is made of an elastic material with a closely tight surface such that the cover is watertight and water absorption is prevented. The cover is tube-like with a shape adapted to the limbs to be replaced. It can be fastened to the respective parts of the prosthesis with its both opening portions spaced from one another. Thus, only the prosthesis is watertightly sealed such that in principal some kind of bathing prosthesis is provided on the basis of a regular prosthesis. The transition from the upper prosthesis edge to the skin of the person wearing the prosthesis is, however, not watertight or protected against the penetration of water into the inside the cover or the prosthesis, respectively, such that water can penetrate into the same. Without the outside sealing the material of the cover is not watertight but will absorb water, since here a regular textile is pulled over the prosthesis and is sealed.
U.S. Pat. No. 5,593,453A discloses a prosthesis cover of a watertight latex material which closely conforms to the shape of the limb being covered. On the inner surface the cover has an anti-friction inner surface. Further, the cover has an anti-skid sole in the case of a leg cover. The anti-skid surface is provided with a plurality of inwardly directed ribs formed on the inner surface of the leg portion of the cover, the plurality of ribs being spaced apart from each other with each rib extending concentrically of the leg portion. The plurality of ribs extends from just above an ankle portion throughout the height of the leg portion to just an upper segment to space the cover from the prosthesis and to thereby reduce the frictional engagement when the cover is being applied by sliding over the prosthesis. At the outside the cover has finger loops for enabling the pulling on and off which finger loops will negatively affect the aesthetic of the cover and cannot provide the impression of a human skin.
The object of the present invention is therefore to overcome the problems mentioned with regard to the known protective devices and to create a device to replace both the bathing prosthesis and vacuum or shrink tubes as well as the above mentioned protective devices which enables the wearer to shower and swim safely, and to participate fully in beach life actively and without attracting undue attention, wherein the penetration of water and foreign bodies, respectively, like sand, dirt, dust, into the inside of the protective device can securely be prevented.
SUMMARY OF THE INVENTION
The object is solved for a protective device for use for exterior prostheses in that the protective covering is made from an at least semi-elastic, waterproof or watertight or custom-designed sufficiently preventing water from penetrating the inside of the protective covering resilient and durable and damage-resistant material, and has a cuff or sleeve or collar like at least semi-elastic device at one end thereof the dimensions of which are adapted to the contours and size of the anatomy of the person wearing the protective covering to prevent water or moisture or foreign bodies from penetrating into the protective covering. Refinements and advanced embodiments of the invention are defined in the dependent claims.
Accordingly, a protective device for use for exterior prostheses is created that is worn as a protective covering over a conventional prosthesis. In this way, it serves as protection therefore, since it is thus possible to effectively prevent water and foreign bodies from penetrating the prosthesis and, thus, damaging the prosthesis by penetrating water or penetrating foreign embodiments, like especially sand, can be effectively avoided. The term watertight means waterproof and splash water resistant and water resistant as well as moisture proof. The feature of a custom-designed sufficient obviation of a penetration of water into the protective covering means that dependant on the respective use the protection by the material of the protective device as well as the protective device itself is made such that the entrance of water or moisture into the protective device can be avoided. The material of the protective device thereby is watertight, the construction of the protective device as well as its treatment especially with regard to the connection area of the material is custom-designed or with regard to the respective use avoids the penetration of water into the protective device. Hereby, especially splash water but also water during a shower or bathing can be prevented from entering the inside of the protective device. Therefore, the cuff or sleeve or collar like at least semi-elastic device is provided which provides a secure bearing of the protective device on the skin of the person wearing the prosthesis by optimally adapting its shape to the body part next to the prosthesis where the protective covering holds tightly on. By this shape adapting combined with the at least semi-elasticity the protective device adheres optimally onto the skin of the person wearing the protective device. The protective covering according to U.S. Pat. No. 5,593,453 A only has a conically shaped upper end portion which is, however, made as one part with the rest of the protective covering. No cuff or sleeve or collar like device is, thus, added contrary to the present invention, where the device is made of a material providing a very good bearing on the extremity stump which device is made of at least semi-elastic material. So, the prosthesis is optimally protected against damages by the material of the protective covering and the prosthesis is further optimally protected against damages by penetration of water, moisture, foreign bodies etc. by the sleeve or collar of cuff like at least semi-elastic device attached to the rest of the protective covering such that the device and the rest or main body of the protective covering can be made of optimal materials each being attached to one another. Thus, the prosthesis is optimally protected in every aspect.
By the use of an at least semi-elastic material, that is to say a material of which at least a part has elastic properties, and which is adapted to the contours of the body, the protective device fits closely, at least at the pertinent points, against the extremity stump to which the prosthesis is attached, and possibly also against the prosthesis, so that the protective device remains in the desired position, this alone helping to prevent penetration at least by dirt such as dust, but also by sand. The dimensional conformation to the shape of the body is understood to mean dimensional conformation to the anatomy of a person, not necessarily a specific person, but generally to the shape and size of human bodies. Mass production is possible in this context, but so is individual adaptation to a specific person, of course. In mass production, the protective device may offered in various sizes, reflecting the differing anatomies of people, some of whom may be taller or stouter, according to the same principle that is applied for clothing in different sizes. In this way, an adaptation to the body of the person wearing the protective device may also be made visually, which represents an aesthetic advantage over the tubes of the prior art, which cannot be adjusted dimensionally to the body shape, but are instead significantly oversize, and accordingly hang over the anatomical shape of the person like a cloth, particularly in the area of a person's arm or leg, after shrinking or removal of the air.
Using a durable, damage-resistant material helps to prevent cracks from forming when the protective device is used, which would allow water and foreign bodies to enter the inside of the protective device. A durable, damage-resistant material is understood to be material that is relatively tear-resistant, and thick enough not to rip for example if it scrapes on stones or other hard objects in passing. In this context, durable means that the material is capable of withstanding stresses without suffering any, or at least essentially any damage, particularly without ripping. In this context, damage-resistant particularly means that the material may only be separated by deliberate cutting, but is otherwise stable enough to protect the person wearing the protective device from the entry of moisture or foreign bodies. Watertight non hydrophilic materials such as chloroprene rubber, polychlorophene rubber or chlorobutadiene rubber, thus, foamed rubber materials, have proven to be particularly suitable for this purpose. Latex material is not understood to be a damage-resistant or durable material. The materials mentioned in the prior art, such as latex, do not show the desired stability and durability. Especially an easy moving and sporting at the beach or any gardening is not possible with these kinds of protective devices. Further, the protective devices according to the prior art may not be combined with bathing shoes worn over the protective devices. This means an essential disadvantage since the normal prosthesis has an ankle which is always set in a specific angle dependent on the desired heel height. Without a shoe the leg may be brought automatically and inadvertently into a hyper extended position. In such a position someone can do swimming without any problems. When he wants to run or walk this is not possible without any risk when he does not wear shoes which wearing of shoes is possible with the protective device according to the present invention and which is, however, not possible with the protective devices according to the prior art as cited above. Walking or running along the beach, especially sporting, as well as gardening is, thus, not possible without any difficulty with protective devices according to the prior art.
Of special advantage is a cuff or sleeve or collar like device which is added to the material provided for the rest of the extension of the protective device which is, thus, added as a sleeve or collar to the end side of the protective device. By this cuff or sleeve or collar like device it is possible to provide the inner surface of the cuff or sleeve or collar like device directed to the inside of the protective device with an adhesive effect or with an adhesive, respectively. A penetration of humidity or moisture or water is securely avoided by use of the sleeve or collar like device. The device is furnished with an opening. This is usually at least the opening through which the wearer slides the protective device on, that is to say the end of the protective device that subsequently lies against the extremity stump. Since the device is dimensioned so as to conform to the wearer's anatomy, it fits particularly closely against the extremity stump, which already helps to prevent water and foreign bodies, especially dust, from getting into the protective device.
The cuff or sleeve or collar like device may include a long-lasting elastic material with adhesive effect, particularly latex and/or silicone, and/or a material having a smooth surface with adhesive property. Simply by virtue the material's elasticity, as already mentioned, the cuff or sleeve or collar like device already lies very close against the wearer's skin adjacent to the prosthesis, which also provides good protection against penetrating moisture but also against the entrance of dust. Unlike a shrink tube, the protective device may also be removed very easily after use, and may, thus, be used repeatedly.
As has been described, the protective device is made at least in part from a chloroprene rubber, polychloroprene rubber or chlorobutadiene rubber. The side of the chloroprene, polychloroprene or chlorobutadiene rubber that is intended to lie against the skin of the wearer may be provided in the end or side area or in the area of the sleeve or collar like device of the protective device, which is shaped so as to cover the prosthetic wearer's skin, with a smooth surface having adhesion properties, designed as smooth skin Neoprene® for example. Providing such a border or selvage or designing the device with such cuffs that are attached to rest of the material of the protective device also serves as a further measure for preventing water from getting inside the protective device when this border or cuff or sleeve or collar like device fits tightly against the skin of the person wearing the prosthesis.
The device shaped as a selvage or shaped as an attached sleeve or collar having a wedge of silicone or latex may be provided to create good grip on the skin of a person wearing the protective device. The device also may be made of silicone or latex material. Since the device advantageously has an adhesive effect, thus an adhesive or gluing effect, a very good and tight sticking on the skin surface of a person is possible by such an adhesive effect.
To achieve particularly good waterproofing and a much better sticking on the skin surface of a person, in this area, a skin adhesive may be applied to the smooth border area of the protective device that has adhesive properties, i.e. the cuff like or sleeve like or collar like device. This may be a liquid or have the form of a double-sided adhesive tape or another form of an adhesive. It is applied to the end on the inside of the protective device that is designed as the protective covering, in other words the side intended to contact the person's skin, where an opening is provided for putting on and taking off the protective covering. When the protective covering is shaped like a long stocking for protecting a leg prosthesis, the device and the skin adhesive are advantageously provided in the area in which the protective covering is in contact with the prosthetic wearer's skin.
Alternatively to applying skin adhesive, or possibly in addition to such application, a separate, cuff-like covering element made from a waterproof material or a material preventing the penetration of water, particularly silicone and/or latex, may be provided. This may cover both the border area of the protective device and the skin of the person wearing the protective device, thus providing protection against penetration particularly by moisture and water and dust. A material having an adhesive effect can be printed e.g. to the outside of the cuff or sleeve or collar like device provided at the end of the protective device, so that a watertight connection is possible by overlapping the sleeve or collar like device by the cuff-like element. Thus, attaching the protective device to the skin of the prosthetic wearer adhesively or providing the cuff-like element in this way helps to reliably prevent water and foreign bodies from getting inside the protective device, even while pursuing various types of water sport. Providing a latex or silicone cuff to form the end of the protective device's border, that is to say either as a border edge or sleeve or collar like device previously attached to the protective device or as a separate covering element, is able to create a waterproof attachment to a person's skin even without using a skin adhesive.
The unfurling effect of the end side boarder area, thus the boarder portion, or the cuff of sleeve or collar like device during the wearing by a person can be avoided by sticking the device to the person's skin. Further, it is possible to provide the device with at least one device preventing the unfurling movement. The same can be built as at least one pocket like unfurling preventing device with at least one stick like reinforcing insert. The pocket like unfurling preventing device can be applied onto the material of the protective device, e.g. in the form of an ironed material patch, when provided as a rubber material or being applied adhesively or in another way when coated with an adhesive material. For providing a stiffening or reinforcing effect in order to avoid any unfurling movement of the edge or boarder portion of the protective device at least one reinforcing insert is inserted, e.g. in the form of a stick, in the pocket like unfurling preventing device. By the subsequent inserting it is possible to withdraw the reinforcing insert for cleaning the pocket like unfurling preventing device. Alternatively, it is possible to provide at least one reinforcing device which is not removably fixed onto the material of the protective device.
Here it should be emphasized that the providing of a skin adhesive, of a separate cuff like covering element or of an unfurling preventing device advantageously provides additional components which are not necessary for the protective device. By use of these additional components the water tightness may be increased for specific cases of operation or use, where larger forces impact the protective device and result in a releasing effect of the protective device with regard to the skin surface of the person wearing the same. This effect may for example appear during diving or if the body shape in the area of the extremity stump of the person wearing the protective device is distinctively conical.
It is further advantageous if the protective device is constructed in multiple layers. In this case, the protective device may include at least one foam layer, for example a layer of foam chloroprene rubber, polychloroprene rubber or chlorobutadiene rubber. To ensure a sturdy, easy to handle surface, at least one side of the protective device is also furnished with a surface coating, in particular it is laminated. Such a surface coating or lamination may be provided on one or both sides, that is to say on the outside and/or the inside of the protective device. In all cases it is also possible not to provide any surface coating or lamination. Suitable materials for such surface lamination particularly include lycra and nylon, which are particularly applied as a woven surface.
The selvage or the sleeve or collar like device of the protective device may be made from a chloroprene rubber, polychloroprene rubber or chlorobutadiene rubber, which may be laminated or unlaminated. This is advantageously made from smooth skin Neoprene® on the side facing towards the person wearing the protective device, and in this context it has a lamination on one side and is unlaminated on the other side and has a smooth surface of chloroprene rubber, polychloroprene rubber or chlorobutadiene rubber to show the intended adhesive effect directed to the skin of the person wearing the protective device. If a selvage or a sleeve or collar like device, respectively, of silicone and/or latex is provided, this advantageously has the form of a cuff in solid material. If technically possible, the cuffs may also be laminated on the side facing away from the person wearing the protective device. The device for protecting against wet and moisture and for preventing penetration by dust, sand and dirt may thus have the form either of a cuff made particularly from the materials described above and be connected to the rest of the material of the protective device or affixed thereto, or it may be conformed directly with the rest of the material of the protective device or fitted onto it.
The abutting points of the protective device material may be essentially sealed to make them watertight, particularly by sewing, welding or adhesion. A mixture of these joining methods is also easily possible, The material used to manufacture the protective devices may have a material thickness from 0.5 mm to 5 mm, for example, particularly from 1 to 3 mm. This lends the protective device very good stability combined with sufficient but not excessive rigidity, while still retaining all possible dimensional stability. When a thin material is used for the protective device, that is to say precisely with chloroprene rubber, polychloroprene rubber or chlorobutadiene rubber, such material may be butt welded and the weld seam may be covered with corresponding strips. In this way, the abutting points may be rendered sufficiently waterproof and durable even when a thinner material is used. Besides the foam layer, other material layers may also be provided, which are joined together one on top of the other to create the material of the protective device. For example, the outer layers may also be provided using materials that are highly abrasion-resistant and for example resistant to seawater.
In addition, at least one material or material patches that increase friction may be provided on the sole area of a foot, ensuring good grip when the wearer is walking over rocks or other slippery surfaces. The sole is thus rendered non-slip by design, particularly by coating.
The sealed construction of the protective device itself and its close fit against the skin of the person wearing the prosthesis, particularly if no adhesion is applied there and no separate cuff-like covering element is used, serves to effectively keep out of the protective device's inside not only water, but also sand and dust of course, thus also successfully preventing the prosthesis from being damaged. Accordingly, it is not necessary to use additional waterproofing means or means to prevent dust and sand from getting in.
The protective device may be designed in the manner of a sleeve or legging with integral hand or foot element. It is also possible to design the protective device as a tubular arm or leg covering without a hand or foot element. If the hand or foot element is created integrally with the protective device, particularly secure protection is provided against penetration by water or moisture, since then only one opening must be securely closed and sealed. In the case of a tubular protective device that has however been adapted dimensionally to fit the person wearing it, and in which the hand or foot of the person wearing the prosthesis protrudes out of the protective device, two openings are provided in the protective device, and these are located and particularly secured by adhesion at the wrist or ankle, that is to say in the area of the hand or foot of the person wearing the prosthesis, and in the area of the shoulder or thigh or hip of the person wearing the prosthesis.
The protective device may also be designed as a one-legged trouser-like covering incorporating the form of the body part or the torso of the person wearing the protective device. Such a design is particularly suitable for people who only have very short stumps in the area of their extremity, making it almost impossible to affix the protective device securely there. For this purpose, the protective device is then designed as a trouser-like covering of a covering incorporating the form of the torso, so that it may be affixed elsewhere on the body and not at the extremity stump. In this case too, an adhesive material or skin adhesive or a respective cuff or sleeve or collar like device may be applied to the respective openings where water or moisture, or also dust and sand might enter, in order to provide waterproofing or at least to make it difficult for water, moisture, dust, sand and foreign bodies to get in.
In terms of appearance, the protective device may be adapted to the normal skin colour of the wearer, or it may be coloured differently. Contrary to the prior art this is possible and will lead to a result having a very good appearance. Conventional methods such as silk-screen printing, or also lacquering and airbrushing may be used to colour the material. The natural colour of a laminating material, which may be in a variety of colours, may also be used on the side of the protective device that faces outwards, that is to say away from the wearer. The material used for the protective device may also be dyed in all cases.
The protective devices may be cut into shaped panels from a chloroprene rubber, a polychloroprene rubber or chlorobutadiene rubber, and subsequently joined at their abutting points, for example by sewing, adhesion or welding. The lamination or coating is applied to the base material or along the abutting points of the material panels of the sleeve and legging shapes where applicable before joining. A coating may be or may have been applied to both sides or also to just one side, so that in the finished legging or sleeve shapes a coating is provided only on the outside, or only on the inside, of on both the outside and the inside, by placing another material layer over the top of it, or laminating over it. The material specification or design, that is to say its colour, the material used one-sided or double-sided lamination or coating, one-sided smooth surface and so on, may be incorporated in the base material, that is to say in the yard goods or when the panels are cut. One layer of a foam chloroprene rubber, polychloroprene rubber or chlorobutadiene rubber for example, such as are marketed under the Neoprene® brand by DuPont for example, is provided as the middle layer in a multilayer construction of the protective device. However, it may also be prepared as the only layer. Accordingly, the possible construction variants are such having only one semi-elastic and essentially water impermeable material layer, such having a lamination or coating only on the outside, that is to say facing away from the person wearing the protective device, such having a lamination or coating only on the inside, that is to say facing towards the person wearing the protective device, and such having both an inner and outer coating or lamination. A solid material mad from a material having adhesive properties, such as latex or silicone, may be provided for the selvages or cuffs. The base material of the protective device may also be designed with a smooth surface on the inside, facing towards the person wearing the protective device, in which case in particular an outer lamination or coating may also be provided. Not only the base material, but also the selvages or cuffs or sleeve or collar like devices may be prefabricated and merely cut to size according to the intended application before they are joined to the rest of the protective device material.
In the case of injured limbs, water sports and visits to the beach are avoided to protect the wound from exposure to moisture and dirt. To enable the injured person to actively participate in beach activities, and even pursue water sports despite this, a protective device for protecting limbs against contact with moisture, and particularly foreign bodies such as dirt, includes furnished with a protective covering made from an at least semi-elastic, water impermeable or custom-designed sufficiently preventing the inside of the protective device from the penetration of water, resilient and damage-resistant material and that has been adapted to conform to the body size and shape and at least one end of which is equipped with a cuff-like, sleeve like or collar like device having a size and anatomically conformed shape for preventing penetration by water or moisture and foreign bodies. The devices may be or have been constructed in the same way that the device described previously for protecting an exterior prosthesis.
The present protective device thus has the advantage with regard to known bathing prostheses in that it is very much smaller and easier to handle, which is a significant advantage, particularly when travelling. An extra bathing prosthesis does not need to be included in luggage, only the small, folding protective device, which fits into luggage like any normal item of clothing. Moreover, it is not necessary to bring a pumping bulb or a heat radiating device for shrinking protective devices so that they lie flush against the wearer's skin, and this is also an important advantage over the tube-like protective devices according to the prior art, which are only available in standard sizes. These advantages may be enjoyed not only when travelling but during any other leisure activities, particularly in recreational sport, since here too the protective device may be carried in a sports bag much more easily than other protective devices, such as bathing prostheses above all but also such tube-like devices that must be shrunk or require means for creating a vacuum. Also with regard to the other above mentioned protective devices according to the prior art the protective device according to the present invention is more comfortable during use, thus, also during its pulling on and off as well as during maintenance and cleaning. Also, any necessary repairs can be done much easier since on one hand the multilayer material can be better repaired and on the other hand the cuff or sleeve or collar like device can be much easier and better changed or repaired when being deteriorated or damaged because of the attachment of the cuff or sleeve or collar like device to the rest of the protective device.
DESCRIPTION OF THE DRAWINGS
In the following text, embodiments of the invention will be described in greater detail, with reference to the drawing for detailed explanation thereof.
In the drawing:
FIG. 1 a is a side view of a first embodiment of a protective device according to the invention for use for arm prostheses,
FIG. 1 b is a side view of a variant of the embodiment of the protective device of FIG. 1 a,
FIG. 2 a is a side view of a second embodiment of a protective device according to the invention for use for an arm prosthesis,
FIG. 2 b is a side view of a variant of the embodiment of the protective device of FIG. 2 a,
FIG. 3 is a side view of an embodiment of a protective device according to the invention for use for a leg prosthesis,
FIG. 4 is a side view of a further embodiment of a protective device according to the invention for use for a leg prosthesis,
FIG. 5 is a side view of a seventh embodiment of a protective device according to the invention for use for an arm prosthesis,
FIG. 6 is a side view of an eighth embodiment of a protective device according to the invention for use for a leg prosthesis,
FIG. 7 is a side view of a ninth embodiment of a protective device according to the invention for use for an arm prosthesis, in the form of a protective covering that incorporates the upper body,
FIG. 8 is a side view of a tenth embodiment of a protective device according to the invention for use for a leg prosthesis, in the form of a trouser-like protective covering.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 a and 1 b show embodiments of a protective device 1 in the form of a “sleeve”, that is to say a protective covering for an arm prosthesis. The protective device is furnished with an arm section 10 and a hand section 11 with a finger section 12 , which is shown fully with clearly illustrated fingers in the embodiment in FIG. 1 a , but only indicated or reproduced as a mitten in the embodiment in FIG. 1 b . The finger section covers the fingers of the hand prosthesis like a glove, just as the hand section of protective device 1 covers the rest of the hand prosthesis. The arm section covers both the arm portion of the prosthesis and a part of the extremity stump of the person wearing the prosthesis, that is to say it fits closely against the skin. This close fitting against the skin occurs at least at the upper arm end area 13 . At least the inside of this area is provided with an adhesive material or consists of such an adhesive material to provide watertightness and ensure a good grip in this area. For example, protective device 1 has a cuff or sleeve or collar like device 130 , for example in the form of an affixed cuff in upper arm end area 13 . It can be made from latex and/or silicone. Another smooth surface having adhesive properties may also be provided here directed to the extremity stump, thus, on the inside of the protective device 1 or the cuff or sleeve or collar like device 130 . If a material other than latex and/or silicone is used for upper arm end 13 , if necessary a wedge-shaped insert or an insert made from latex and/or silicone may be provided and this significantly increases grip on the extremity stump and skin of a person wearing the protective device. Otherwise, the material of the protective device or the cuff or sleeve or collar like device 130 has a degree of elasticity at least in the area of the arm section adjacent to the upper arm end and in the upper arm end area so that it is able to lie particularly snugly and tight against the extremity stump, and is able to create a tight closure against the skin of the person wearing the prosthesis.
FIGS. 2 a and 2 b show a second embodiment of a protective device 1 in the form of a sleeve, this embodiment being very similar in principle to the embodiment shown in FIGS. 1 a and 1 b . Unlike that embodiment, however, the protective device 1 of FIGS. 2 a and 2 b does not have an upper arm end with affixed latex and/or silicone. Instead, inside of the upper arm end in the form of a cuff or sleeve or collar like device 130 , facing towards the person wearing the protective device, is provided with a smooth surface having adhesive properties, particularly produced from a smooth skin Neoprene®. The upper arm end may be attached to the rest of the material of the protective device or it may be produced as an integral part thereof. In order to ensure waterproofing when lying on the skin of a person wearing the protective device 1 , a skin adhesive 131 may additionally be applied to the smooth surface, which already has inherent adhesive properties, thus enabling a particularly secure and tight connection with the skin of the person wearing the sleeve. This variant is used particularly when smooth skin Neoprene® is provided, but it may be used equally well with an attached silicone cuff. A silicone material can advantageously be used especially for people who react on latex material or are allergic with regard to latex material. It should be noted that an additional waterproof seal is assured by just a latex or silicone cuff such that no further means are necessary for providing a protection against the penetration of water, especially in case of a desired splash water protection.
Instead of a skin adhesive, a cuff-like covering element 132 may be pulled over the selvage of the protective device and the wearer's skin to provide good protection against penetration by moisture and water and dust or dirt. Such a covering element is shown in FIG. 2 b by broken lines. For a specific watertight connection the protective device may be provided with an adhesive material in the area of the upper arm and on the outside 133 , e.g. in the form of a printing 134 . This is indicated in FIG. 2 b.
For use for a right and left arm, either the same protective devices 1 or correspondingly adapted, differently conformed protective devices may be provided. Coatings may be provided to improve anti-slip characteristics particularly on the palm, and optionally in the area of the finger sections. This enables the person wearing the prosthesis to support himself on the prosthetic hand if necessary without fear of slipping over, particularly on wet and therefore slippery surfaces.
FIG. 3 shows protective device 1 in the form of a “legging” for pulling over a leg prosthesis. This protective device is designed analogously with protective device 1 shown in FIGS. 1 a and 1 b , but is provided with a leg section 14 and a foot section 15 . Instead of an upper arm end 13 , hear a thigh end 16 is provided, which also ensures protection against penetration by water and foreign bodies, if necessary even without use of a skin adhesive. For this purpose, the thigh end also has a surface having adhesive properties in the area of the cuff or sleeve or collar like device 130 . This consists in particular of a long-lasting elastic material with adhesive effect. As for upper arm end 13 , thigh end 16 may also often be realised as a separate element and attached to leg section 14 or arm section 11 . Thigh end 16 is made for example from latex and/or silicone or it has a corresponding insert made from latex and/or silicone. It is also possible to apply an adhesive coating or lamination to the thigh end or upper arm end in the area of the cuff or sleeve or collar like device 130 on the side thereof facing the skin of the wearer, or to use a material with corresponding adhesive properties, particularly smooth skin Neoprene®.
Such an alternative embodiment to the embodiment of a legging of FIG. 3 is shown in FIG. 4 . The legging shown here differs from the embodiment of FIG. 3 only in that a smooth surface having adhesive properties, particularly a smooth skin Neoprene®, is provided in the thigh end area or the area of the cuff or sleeve or collar like device as an inner surface, that is to say facing towards the person wearing the protective device. The thigh end may be attached to the rest of the material of the protective device as a cuff, or it may be produced integrally therewith. Is for the embodiment of FIGS. 2 a and 2 b , a skin adhesive is also used here, ensuring a much better watertightness when it is applied to the skin of the person wearing the prosthetic. Otherwise, watertightness may also be assured simply by providing a wedge insert made from latex and/or silicone. A further alternative to this embodiment consists in providing a separate cuff-like covering element 135 , made from latex and/or silicone for example. This is pulled over the border of the protective device and over the skin of the person wearing the protective device, and is thus able to prevent particularly moisture and water and dust and dirt from penetrating the protective device as just mentioned above with regard to FIGS. 2 a and 2 b . Like there an additional sealing by for example printing an adhesive material onto the outside 136 of the protective device in the form of a printing 137 in the area of the thigh end is possible here (at least indicated in FIG. 4 ). To avoid an unfurling of the thigh end a number of pocket like unfurling preventing devices 180 with rod or stick like reinforcing inserts 181 is applied there. The reinforcing inserts 181 can be removed for cleaning such that the pocket like unfurling preventing devices 180 are open at one side. They can also be totally closed such that the removing of the reinforcing inserts is no longer possible. The reinforcing inserts 181 can also be directly applied to the material of the protective device in the area of the thigh end, for example they can be sewn on or stitched in there. However, no removing of the sticks or rods is possible then.
In the embodiments of the protective device shown in FIGS. 3 and 4 , both soles 17 of the two leggings may be furnished with an anti-slip coating 170 . Particularly on wet and slippery surfaces, this is able to provide better grip for the prosthesis wearer.
Since the sleeves in FIGS. 1 a , 1 b and 2 a , 2 b are each shown with an attached or integral hand section 11 and finger section 12 , the hand and finger sections of protective device 1 are not shown in FIG. 5 . This protective device is simply tube-shaped like arm section 10 . However, this embodiment also has an upper arm end 13 with a cuff or sleeve or collar like device 130 exactly like the embodiment of FIG. 1 . In addition, a wrist end 18 is also provided in the wrist area of the arm prosthesis to create a seal. As before, upper arm end 13 is advantageously made from a long-lasting elastic material with adhesive effect, particularly latex and/or silicone or provided with a material having adhesive effect and optionally a skin adhesive to create a seal sealing against the penetration of water with the skin of the person wearing the prosthesis. Since wrist end 18 lies flush with the prosthesis surface, so that the prosthetic hand is uncovered, a sealing end is created with the surface of the prosthesis in the area of wrist end 18 , and a long-lasting elastic material with adhesive effect may be advantageously used here too.
FIG. 6 shows a corresponding legging design without a foot section. In this case, the prosthetic foot of the person wearing the this prosthesis is uncovered, and the legging has an ankle end 19 in the area of the ankle of the prosthesis. Thus, protective device 1 as shown in FIG. 6 only includes one leg section 14 with a thigh end 16 at one end, and accordingly there are two openings, which are in watertight contact with the skin of the person wearing the prosthesis and also with the prosthesis itself. Here too, long-lasting elastic materials with an adhesive effect may be provided, particularly as a solid material, for example latex and/or silicone, in the area of the thigh end and the ankle end, in the form of cuff or sleeve or collar like devices 130 .
The two opposite ends of both the sleeve of FIG. 5 and the legging of FIG. 6 may also be provided only with a smooth surface having at least a small amount of adhesiveness, and may be affixed to the skin or the surface of the prosthesis in watertight manner by adhesion with the aid of a skin adhesive. However, the provision of an adhesive material that is able to function without the use of an adhesive is more suitable, particularly in the area close to the prosthesis, since the adhesive would have to be removed from the prosthesis without causing it any damage when the protective device is removed. Accordingly, the use of materials, such as latex and silicone, for example, which have inherent adhesive qualities, and which can be removed from the surface of the prosthesis without residue and without attacking the prosthesis, is advisable. For this reason, a cuff-like covering element made from latex and/or silicone that is arranged to cover the respective selvage of the protective device and the uncovered prosthesis is most suitable.
FIG. 7 shows a further embodiment of a protective device 1 , which in this example is configured as a protective covering incorporating the upper body. This example is similar in shape to a pullover in which the sleeve on one side is conformed to a hand section, but there is no second sleeve. Thus, protective device 1 has a torso section 20 , an arm section 21 and a hand section 22 with finger section 23 . The arm prosthesis arranged on the side of arm section 21 , hand section 22 and finger section 23 may thus be fully covered and protected. Especially when the extremity stump is too short to allow a protective device to be attached securely here, attachment is assured in such manner that very good attachment to the body of the person wearing the prosthesis is possible via torso section 20 . The healthy arm protrudes through a corresponding arm opening 24 in the torso section. Torso section 20 is also furnished with a neck opening 25 and a bottom opening 26 facing towards the abdomen. Cuff or sleeve or collar like devices or elements for protecting against penetration by water, moisture and dirt are advantageously provided in the area of these three openings 24 to 26 , particularly a long-lasting elastic material having an adhesive effect on at least one side, such as smooth skin Neoprene® or latex or silicone as solid materials, wherein material coatings or laminations having adhesive properties may be applied to another material. It is also possible to use for example a chloroprene rubber, polychloropene rubber or chlorobutadiene rubber with a smooth, adhesive surface, in which case a skin adhesive may be applied additionally here as well to provide a watertight seal in the area of openings 24 to 26 .
FIG. 8 shows a corresponding counterpart to the embodiment for the arm prosthesis in the form of a protective device 1 constructed in the manner of a single trouser leg for a leg prosthesis. One leg of this trouser-like protective device is then designed in the manner of a pair of tights, while the other only extends with a thigh section 27 over a portion of the healthy thigh of a person wearing a one-sided leg prosthesis. The leg prosthesis is accommodated completely in the leg section 28 conformed in the manner of one half of a pair of tights. The leg section is also furnished with a foot section 29 . In this manner, it is possible to fully enclose the leg prosthesis, thus ensuring reliable protection for the leg prosthesis even if the extremity stump is too short at the thigh to allow a protective device as shown in FIG. 3 or 4 to be attached securely thereto.
The two remaining openings 30 , 31 in the thigh section and in the area of the thigh of the person wearing the protective device may also be conformed variously to provide a watertight seal, and in particular cuff or sleeve or collar like devices 130 made of a long-lasting elastic material having adhesive properties and having a smooth surface with adhesive properties may be provided, and may optionally be affixed to the skin surface of the person wearing the protective device using a skin adhesive. It is also possible to provide for example a cuff made from latex and/or silicone.
A design that is conformed to the body shape of the person wearing the protective device is particularly advantageous especially in the embodiments shown in FIGS. 7 and 8 , since when the material is lying very closely against the person's skin, the desired sealing effect may be assured, and the person is also not impeded unnecessarily by the protective device.
Many other shapes may be created besides those shown, particularly also combination shapes of the variants illustrated. In particular, the two embodiments of FIGS. 7 and 8 may also be realised without a hand section or a foot section respectively, that is to say they may be equipped correspondingly with a wrist end or ankle end. In any case, it is advantageous to provide a secure attachment to the body of the person wearing the prosthesis in order to protect the valuable prosthesis from damage, particularly caused by penetrating dust, sand and water, especially seawater. An injured arm or leg may also be protected from contact with moisture and foreign bodies by a protective device of such kind.
Chloroprene rubber, polychloroprene rubber or chlorobutadiene rubber, particularly in the foam forms, are suitable materials for the protective device, and the material of the protective device may also be created using multiple layers as indicated e.g. in FIG. 6 . In this case the layer 171 of foam material may be provided particularly effectively as the inner material layer, while other material layers 172 , 173 having greater resistance to wear are arranged above and below it. Layers of such kind may be made from lycra and/or nylon or other wear-resistant materials. The cut material panels are joined by sewing, adhesion, welding, or by some other process to form a sealed protective device. A seam 32 of such kind is indicated in FIGS. 5 and 6 . The surface of the protective device may be dyed, in particular to match the skin colour of the individual wearing the prosthesis. A lamination or coating may also be coloured. It is even possible to simulate body hair with colouring methods.
Besides the embodiments described above of protective devices for use for exterior prostheses, many other embodiments may also be created, in which the protective device in each case is a protective covering made from an at least semi-elastic, watertight or essentially watertight, or resistant to water penetration or splash water or waterproof, durable, tear-resistant and damage-resistant material that is dimensionally conformed to the shape of the body, and at least one end of which is furnished with a cuff or sleeve or collar like at least semi-elastic device the dimensions of which are conformed to the body shape of the person wearing the protective device so that water or moisture and foreign bodies are unable to penetrate. The elastic device especially adheres to the person's skin and prevents penetration of water or moisture or dirt or dust, respectively, or foreign bodies into the inside of the protective device.
While in accordance with the patent statutes, the best mode and preferred embodiment have been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.
REFERENCE NUMERALS
1 Protective device
10 Arm section
11 Hand section
12 Finger section
13 Upper arm end
14 Leg section
15 Foot section
16 Thigh end
17 Sole
18 Wrist end
19 Ankle end
20 Torso section
21 Arm section
22 Hand section
23 Finger section
24 Arm opening
25 Neck opening
26 Lower opening
27 Thigh section
28 Leg section
29 Foot section
30 Opening
31 Opening
32 Seam
130 cuff or sleeve or collar like device
131 Skin adhesive
132 covering element
133 outside
134 printing with adhesive material
135 covering element
136 outside
137 printing
170 Anti-slip coating
171 layer of foamed material/inner material layer
172 upper material layer
173 lower material layer
180 pocket like unfurling preventing device
181 stick rod like reinforcing insert | People who wear a prosthesis currently have to use a bathing prosthesis if they wish to pursue water sports or take a shower or reach a body of water for recreational purposes and take active part in beach pursuits safely. However, these are usually taken off for swimming though this is very often not possible in the case of rocky shores or unsupervised beaches, quite apart from the unwelcome attention to which the person wearing the prosthesis is sometimes exposed in doing so. To solve this problem, a protective device for use for exterior prostheses is suggested, in which the protective device is a protective covering made from an at least semi-elastic, durable and damage resistant material being watertight or custom-designed sufficiently preventing a penetration of water into the inside of the protective covering and being dimensionally conformed to the shape of the body, and at least one end of which is furnished with a cuff or sleeve or collar like semi-elastic device that is dimensionally adapted to the contours of the anatomy of the person wearing the protective covering to prevent water or moisture or foreign bodies from penetrating the protective covering. This is particularly convenient and easy to carry and use when travelling and for recreational sport. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
Electric Power Supplying Well Head Assembly.
2. Description of the Prior Art
In the past, well head assemblies have been devised and used that permit discharge of fluid from a well bore, as well as supplying electrical power to a electric motor driven down hole pump. Such a well head assembly is disclosed in U.S. Pat. No. 3,437,149 that issued on Apr. 8, 1969 to E. T. Cugini and Wallace S. Jeannerett.
The well head assembly in the Cugini patent has the operational disadvantage that the electric power supply conduit extends upwardly above the assembly and precludes a christmas tree array of valves being mounted directly on the assembly. As a result the array of valves is disposed a substantial distance above the Cugini well head assembly.
On wells that are drilled closely together, such as on off shore islands, christmas tree array of valves that have a high vertical profile are undesirable as equipment must be moved periodically over the array in the maintenance of the wells as well as further drilling operations.
A major object of the present invention is to supply a well head assembly that eliminates the operational disadvantage of the Cugini unit by allowing the christmas tree assembly of valves to be supported directly on the uppermost portion thereof, with the assembly including a first horizontal electrical conducting cartridge and second downwardly extending cartridge both of which are disposed below the uppermost portion of the assembly, and the cartridges slidably engaging one another to provide electric power to an electric motor actuated down hole pump.
A further object of the assembly is to support a tubing string in a centered downwardly extending position relative to a casing string, with the tubing string in communication with a normally open pressure actuated valve, and the casing head assembly defining a confined space that may be externally pressurized to actuate the valve to assume a closed position in the event of an emergency.
Another object of the invention is to supply a well head assembly that has a tubing hanger removably and rotatably supported therein with the first electrical conducting cartridge occupying a fixed but removable position, with the second cartridge supported from the tubing hanger, and the well head assembly including indexing means to dispose the tubing hanger in a predetermined position where the first and second cartridges may slidably engage one another to supply electric energy to a down hole pump or other electrical apparatus in the well bore.
A still further object of the invention is to furnish a well head assembly in which the tubing hanger supports the second electrical conducting cartridge in a position a substantial distance below a mounting flange with the second electrical conducting cartridge in a first form of the well head assembly being an integral part of the tubing hanger, and in a second form the second electrical conducting cartridge being removably supported from the tubing hanger.
Yet another object of the invention is to furnish a second electrical conducting cartridge in which the body thereof may be formed completely from a non-metallic, corrosion resistant material that maintains a number of metallic electrical conductors associated therewith in spaced relationship, and eliminates the possibility of these conductors shorting out.
These and other objects of the invention will become apparent from the following description of preferred forms thereof.
SUMMARY OF THE INVENTION
The well head assemblies of the present invention are used in combination with a well bore that has at least one string of casing extending downwardly therein. An electric motor driven down hole pump is located in the bore hole at an appropriate depth, and has a string of tubing extending upwardly therefrom to terminate in an upper threaded end portion. An electric cable that includes a number of electrically insulated electrical conductors extends upwardly in the bore hole from the electric motor of the pump to terminate in an upper end.
The flow of fluid from the bore hole is controlled by a conventional christmas tree array of valves, which array has a lower supporting flange that has a vertical passage therein through which well fluid may flow upwardly.
Each of the well head assemblies of the present invention not only permits electric power to be supplied to the electric motor driven down hole pump, but so supports a christmas tree array of fluid controlling valves that the array will have a minimum height above the well head assembly. Such minimum height is most desirable on wells that are drilled close together, such as on off shore islands, for equipment must be periodically moved over the array of valves on each well in conjunction with maintenance work and further drilling operations.
First and second forms of a well head assembly are disclosed and claimed in the present application. Each of the forms of the well head assembly includes a heavy walled tubular well head member, secured to the upper end of a string of casing, and the tubular well head member held at a fixed location relative to the ground surface by conventional means. The tubular well head member has interior and exterior cylindrical surfaces, an upper end surface, and a transverse bore that extends between the interior and exterior surfaces intermediate the upper and lower end surfaces of the tubular well head member. The transverse bore serves to slidably and sealingly receive a first electrical conducting cartridge that has a number of inwardly disposed, electrical conducting, engaging members that are insulated from one another, and the first cartridge being connected to a source of electric power.
A cylindrical tubing hanger is rotatably and sealingly disposed in the well head member, with the tubing hanger including a top surface, bottom surface, and a generally cylindrical side surface, with the tubing hanger having a centered bore extending upwardly and longitudinally therethrough. The bore includes a lower threaded portion that engages the upper threaded end of the tubing string. A first passage is formed in the tubing hanger that extends upwardly from the bottom surface and intersects a second horizontal passage that is transversely disposed and extends inwardly from the side surface of the tubing hanger. The second passage and the transverse bore have center lines that lie in the same horizontal plane.
First means are provided in the tubular well head member for maintaining the cylindrical tubular hanger at a fixed longitudinal, rotatable position relative to the well head member. A second electrical conducting cartridge is disposed in the first passage and includes electrical conductors that have first engageable conductors extending into the second passage that may be removably engaged by the first electrical conducting cartridge, and second engageable electrical conductors that extend downwardly in the second passage and are engageable by engaging electrical conductors on a connector secured to the upper end of the electrical conducting cable.
In the first form of the invention, the second electrical conducting cartridge forms an integral part of the tubing hanger. In the second form of the well head assembly the second cartridge may be removed from the tubing hanger when desired for maintenance purposes or replacement. Indexing means are provided on both the first and second form of the assemblies for rotating the tubing hanger from the exterior of the assembly to the extent that the second passage is axially aligned with the transverse bore, and the first electrical conducting cartridge then capable of being moved inwardly to removably engage the second electrical conducting cartridge and furnish electric power through the cable to the electric motor that drives the down hole pump. The upper end of the tubular well head member has a mounting flange removably secured thereto on which a lower flange of the christmas tree array of valves is mounted to maintain the array of valves at a minimum vertical profile.
In either the first or second form of the well head assembly, the tubing string may have a normally open pressure actuated valve therein, and the well head assemblies having cooperating passages therein through which pressure may be exerted on the valve to close the same in an emergency to prevent upward flow of fluid through the tubing string.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross sectional view of a first form of the well head assembly, in which the second cartridge is formed as an integral part of the tubing hanger;
FIG. 2 is a longitudinal cross sectional view of a second form of the well head assembly, in which the tubing string has a normally open pressure actuateable valve therein, and in this form of the assembly the valve may be actuated by fluid under pressure that flows from a source thereof to a confined space defined between the well head member and tubing hanger support to a conduit that extends downwardly to the valve;
FIG. 3 is a transverse cross sectional view of the first form of well head assembly illustrated in FIG. 1 taken on the line 3--3 thereof, and illustrating the indexing means prior to the latter being actuated from the exterior of the assembly to rotate the tubing hanger to a position where the second passage and transverse bore are co-axially aligned;
FIG. 4 is the same view as shown in FIG. 3 after the indexing has been completed, and the first cartridge having been moved inwardly into electrical communication with the second electrical conducting cartridge;
FIG. 5 is a combined horizontal cross sectional and bottom plan view of the connector secured to the upper end of the electric cable and taken on the line 5--5 of FIG. 1;
FIG. 6 is an exploded vertical cross sectional view illustrating the first electrical conducting cartridge connected to a source of power and slidably mounted in the transverse bore, of the electrical connector secured to the cable disposed below the tubing hanger, and a section of the tubing hanger being illustrated in which the second electrical cartridge is permanently positioned as an integral part thereof;
FIG. 7 is a perspective view of a pair of blocks of micarda like polymerized resin, with the lower block having prongs extending upwardly therefrom that engage recesses formed in the upper block to maintain the two blocks in a fixed position relative to one another;
FIG. 8 is a perspective view of the blocks being supported in a centered position, for the right hand sections of the two blocks to be turned to a cylindrical configuration that has a pair of sealing ring supporting grooves defined therein;
FIG. 9 is a perspective view of the blocks after the above described operation has been completed, with the block being rotatably supported in an off centered position to permit an off centered cylindrical end portion to be formed on the block by a turning operation;
FIG. 10 is a side elevational view of the turned blocks, that are bonded together with the blocks being drilled both longitudinally and transversely to have first and second passages formed therein as illustrated in FIG. 2;
FIG. 11 is an end elevational view of the turned blocks that form a part of the second cartridge as shwon in FIG. 2;
FIG. 12 is a longitudinal cross sectional view of the block that forms a part of the second cartridge that is removably mounted in the tubing hanger as shown in FIG. 2;
FIG. 13 is an end elevational view of the second cartridge of the removable type shown in FIG. 2, with three electrical conducting prongs projecting outwardly from the off centered end portion thereof;
FIG. 14 is a fragmentary side elevational view of the block that forms a part of the second removably supported cartridge, and illustrating three electrical conducting sockets that are engageable by forwardly projecting prongs on the first cartridge; and
FIG. 15 is a fragmentary vertical cross sectional view of the second cartridge removably supported in the tubing hanger and in engagement with a first cartridge removably and sealingly supported in the transverse bore of the tubular well head member.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first form A-1 of the well head assembly is illustrated in FIG. 1 and in FIGS. 3 to 6 inclusive. The well head assembly A-1 includes a heavy walled tubular well head member B that is maintained at a fixed location relative to the ground surface by conventional means (not shown). The well head member B has a flat ring shaped top surface 10 in which a circumferentially extending groove 10a is formed.
A well head member B has a generally cylindrical exterior side surface 12 that has a circumferentially extending recess 14 formed in the upper portion thereof.
An upper set of circumferentially spaced radially extending threaded rods 16 are rotatably supported in transverse tapped bores (not shown) in the well head member B, with each rod including an inner end portion 16a and an outer end portion 16b that is engageable by a wrench (not shown) for rotating the rod. A lower set of circumferentially threaded rods 18 that are radially disposed are rotatably supported in transverse tapped bores (not shown) defined in the tubular well member B, with each of the rods having an inner end 18a and an outer end 18b that is wrench engageable to permit rotating the rod.
A mounting flange 20 is provided as shown in FIG. 1 that has a ring shaped groove 20a formed in the lower surface thereof and vertically aligned with the groove 10a. The grooves 10a and 20a are engaged by a sealing ring 22. Conventional fastening means 24 removably engage the mounting flange 20 and the recess 14 as shown in FIG. 1 to sealingly maintain the mounting flange on the well head member B.
A first flange 26 that forms a part of a christmas tree valve supporting assembly 28 is mounted directly on the mounting flange 20 and removably secured thereto by bolts 30 as shown in FIG. 1. A transverse bore 32 is formed in the well head member B below the recess 14 as shown in FIG. 1, with the bore 32 having threads 32a defined in the outer portion thereof. The well head member B includes a ring shaped bottom 34 that has an interior surface 36 extending upwardly therefrom, with threads 36a on surface 36 being engaged by threads 38a on the upper end of an outer casing string 38 as shown in FIG. 1.
The interior surface 36 as best seen in FIG. 1 has a body shoulder 36b above threads 36a. The well head member B has an interior cylindrical wall section 36 defined therein above the body shoulder 36b. Upper and lower interior wall sections 36d and 36e are also defined above the wall section 36c as shown in FIG. 1.
A casing hanger 40 is mounted within the well head member B and is in the form of a generally cylindrical shell, which shell includes a horizontal ring shaped abutment 40a from which a first internally threaded tubular portion 40b extends upwardly. The casing hanger 40 as shown in FIG. 1 includes a downwardly and inwardly tapered portion 40c that rests on the body shoulder 36b. The casing hanger 40 also includes a second internally threaded portion 40d as shown in FIG. 1 that engages threads 42a defined on the upper end of an inner casing string 42 that is separated from the outer casing 38 by an annulus shaped space 53.
A tubing hanger C as may be seen in FIG. 1 is situated within the well head member B, which tubing hanger includes a top surface 44, and a bottom surface 46. The tubing hanger is further defined by an upper cylindrical side wall section of 48a that on its lower end develops into a downwardly and outwardly tapering first body shoulder 48b. The body shoulder 48b on the lower end develops into a cylindrical wall surface 48c, which wall surface on the lower end merges into a cylindrical wall section 48d of smaller diameter. The wall section 48d terminates on the lower end in an inwardly extending horizontal abutment 48e that has a cylindrical side wall section 48f extending downwardly therefrom to terminate in the bottom 46.
The tubing hanger C has a centered bore 50 extending upwardly and longitudinally therethrough, with the bore having a lower threaded portion 50a and an upper threaded portion 50b defined therein. An extension 50c of the bore 50 extends upwardly from the upper threaded portion 50b and is of smooth cylindrical configuration.
The lower threaded portion 50a of the bore 50 is engaged by the upper threaded end portion 52a of a tubing string 52 that extends downwardly therefrom in a centered position through the inner casing 42, and is separated therefrom by an annulus shaped space 53. A second electrical conducting cartridge D is provided that is best seen in detail in FIG. 6 and is an integral part of the tubing hanger C. The second cartridge D is defined by a first passage 58 that extends upwardly in tubing hanger D and has a lower cylindrical end section 58a. A second transverse passage 60 is formed in the tubing hanger C and intersects the first passage 58, with the second passage having an outwardly disposed cylindrical end section 60a.
In FIG. 6 it will be seen that the first and second passages 58 and 60 are partially filled with a rigid electrical insulating material 62, such as an epoxy or the like, in which a number of electrical conductors of inverted L shaped configuration are embedded with the conductors having first engaging end portions 64a preferably in the form of prongs extending into the cylindrical end section 60a. The electrical conductors 64 also include engaging end portions 64b that extend downwardly into the cylindrical end section 58a. Grooves 65 are preferably formed in the portions of passages 58 and 60 in which the insulating material 62 is disposed to minimize movement of the material relative to the tubing hanger C.
A first electrical conducting cartridge E is provided as shown in FIGS. 1 and 6 that is defined by a generally cylindrical body 66 formed of an electrical insulating material, such as an epoxy or one of the commercially available polymerized resins. The body 66 includes a forwardly disposed cylindrical portion 66a that is of sufficiently small diameter as to be slipped inwardly through the transverse bore 32 formed in the well head member B.
The body 66 includes an intermediately disposed portions 66b that may snuggly and slidably engage the transverse bore 32, and the body 66 also including a rearward portion 66c of substantially smaller diameter than the intermediate portion 66b. The forward portion 66a has a transverse circumferentially extending groove 66e therein in which a sealing ring 66f is disposed. The forward portion 66a on the rearward end thereof develops into a body shoulder 66g of ring shaped configuration, which body shoulder has a groove 66h therein in which a resilient sealing ring 66j is disposed.
The intermediate portion 66b of the body 66 develops into a rearwardly disposed ring shaped body shoulder 66k. The body 66 has a longitudinal recess 66p therein that extends rearwardly from the forward end 66d, and the recess developing into a longitudinal extending bore 66m that is defined in the rearward portion 66c. A number of first engaging members 68, preferably in the form of electrical conducting sockets, are situated within the recess 66p and are in communication with a number of electrical conductors 70 that extend rearwardly to a cable F that is in communication with a source of electric power (not shown). The recess 66p as may be seen in FIG. 6 is filled with an electrical insulating material 72 such as an epoxy or the like. The rearward portion 66c of the body 60 has a number of resilient rings 74 of the chevron type mounted on the exterior surface thereof.
In FIG. 6 it will be seen that a collar G is provided that includes a tubular portion 76 that has a bore 76a extending longitudinally therethrough and threads 76b being formed on the exterior surface of the tubular portion 76. The rearward portion of the collar G has an enlarged wrench engageable portion 76c defined thereon, which wrench engageable portion permits the collar G to be rotated. The collar G has a forwardly disposed ring shaped end surface 76d.
An electrical conducting cable H extends upwardly in the annulus shaped space 53 shown in FIG. 1 from the motor driven down hole pump (not shown), with the cable as shown in FIG. 6 including an outer sheet 78 that terminates on the upper end in an enlarged portion 78a. The enlarged portion 78a has a lower body shoulder 78b the purpose of which will later be explained.
In FIG. 6 it will be seen that an electrical connector J is provided that is defined by a tubular shell formed from an electrical insulating material, which shell includes an upper cylindrical portion 84a and an intermediately disposed outwardly extending rib 84b. The shell includes a lower cylindrical portion 84c situated below the rib 84b. A circumferentially extending groove 84d is formed in the upper cylindrical portion 84a and has a resilient sealing ring 84e mounted therein. The rib 84b has a groove 84f extending downwardly from the upward surface thereof as shown in FIG. 6 in which a sealing ring 84g is disposed. A bore 84h extends upwardly through the shell 84 and in the lower portion develops into an inwardly extending ring shaped abutment 84j.
A number of insulated electrical conductors 86 are held in spaced relationship within the cable H, with the conductors having second engageable members 88 on the upper ends thereof as shown in FIG. 6. The second engaging members 88 are held in spaced relationship within the connector J by a body of electrical insulating material 90.
The rib 84b has a pair of spaced bores therein through which bolts 94 extend to engage tapped recesses (not shown) in the lower surface of 46 of the tubing hanger, and removably support the connector J from the tubing hanger C.
The well head assembly A-1 includes a retaining ring 96 best seen in FIG. 1 that has an external cylindrical surface 96a in which a pair of spaced circumferentially extending grooves 96b are defined that support a pair of resilient sealing rings 96c. The retaining ring has a bottom 96d and an interior surface 96e. A pair of spaced circumferentially extending grooves 96f are defined on the interior surface 96e, with the pair of grooves supporting resilient sealing rings 96g. The retaining ring includes a ring shaped top surface 96h from which a downwardly and outwardly tapered wall section 96j extends as shown in FIG. 1.
When the retaining ring 96 is disposed as shown in FIG. 1, and the threaded rods 18 rotated, the inner ends 18a of the rods pressure contact the tapered sections 96j of the retaining ring and force the same downwardly, with the downward force being exerted on the casing hanger 40 to force the latter into seating engagement with the body shoulder 36d of the well head member B.
When the tubing hanger C is disposed as shown in FIG. 1, the threaded members 16 when rotated have the inner ends 16a forced into pressure contact with the body shoulder 48b of the tubing hanger, and the center lines S of the second passage 60 and the transverse bore 32 now lying in the same horizontal plane. Although the second passage 60 and transverse bore 32 have the center lines S thereof in the same horizontal plane, the center lines may not be co-axially aligned.
An indexing device K is provided as a part of the well head assembly A-1 that permits limited rotation of the tubing hanger assembly C relative to the well head member B to the extent that the second passage 60 as shown in FIGS. 1 and 6 is co-axially aligned on a center line S with the transverse bore 32. Such alignment permits the first electrical conducting cartridge E to be moved inwardly to removably engage the second cartridge D as shown in FIG. 4.
The indexing device K as best seen in FIGS. 3 and 4 includes a bushing 98 that has a wrench engageable outer end portion 100, and external threads formed on the bushing inwardly therefrom. The bushing has threads (not shown) formed on the interior thereof. The bushing 98 engages a tapped recess 102 in well head member B that is diametrically aligned with the bore 32. The tapped recess 102 on the inner end thereof develops into a transverse bore 102a in the well head member B that is also diametrically aligned with the bore 32. A rod 104 is provided that has a wrench engageable outer end 104a and intermediate externally threaded section 104b and a cylindrical inner end portion 104c. An inwardly tapering recess 106 is formed in the exterior surface of the tubing hanger C and on the inner end thereof developed into a cylindrical cavity 106a that is diametrically aligned with the second passage 60.
When the rod 104 is rotated in a clockwise direction as illustrated by the arrow 108 in FIG. 3, the rod 104 moved inwardly relative to the well head member B. As such inward movement takes place the cylindrical end portion 104c of the rod 104 pressure contacts inwardly tapering recess 106 and rotates the tubing hanger C relative to the well head member B in the direction of the arrow 110 shown in FIG. 3.
Rotation of the tubing hanger C in the direction of the arrow 110 due to the turning of the rod 104 results in the tubing hanger C being rotated to a position where the cylindrical inner end portion of the rod 104 may enter the cavity 106a, with the second cartridge D now being axially aligned with the first cartridge E, and the center line S extending therethrough as well as through the center of the rod 104 as shown in FIG. 4.
The first electrical conducting cartridge E may now be moved inwardly from the positions shown in FIGS. 3 and 6 to that illustrated in FIG. 4, wherein the first engaging electrical conductors 64a are engaged by the first engageable members 68. When such an engagement is achieved, the engagement is fluid tight as the resilient ring 66f is in sealing contact with the cylindrical section 60a shown in FIG. 6. The resilient sealing ring 66j is in abutting sealing contact with the surface 48c of the tubing hanger C. The collar G as shown in FIG. 4 has the threads 76b thereof in engagement with the threads 32a, and as the collar is tightened, the chevron packers 74 are compressed into sealing engagement between the external surface of the body 66, the bore 32, and body shoulder 66k, and the ring shaped end surface 76d of the collar G.
Prior to the engagement above described taking place, the connector J is moved upwardly for the second engageable members 64d to be engaged by the second engaging members 88 of the connector. This engagement is fluid tight, as the resilient sealing rings 84e are in sealing engagement with the cylindrical end section 58a in the tubing hanger C. The sealing ring 84g of the connector J are in sealing abutting contact with the bottom surface 46 of the tubing hanger C. The fastening plate 82 is moved upwardly into abutting contact with the lower surface of the rib 84b and the bolt 94 then tightened to hold the upper portion of the connector J within the confines of the end section 58a of the first passage 58.
The mounting flange 20 as shown in FIG. 1 has a centered vertically extending bore 112 therein that communicates with the interior of the christmas tree assembly 28. The bore 112 end mounting flange 20 develops on the lower thereof into an enlarged cylindrical section 112a. The section 112a is longitudinally aligned with the bore extension 50c formed in the tubing hanger C. The bore 112 and the enlarged cylindrical end portion 112a at their junction define a body shoulder 112b. The bore extension 50c as shown in FIG. 1 at the junction with the threaded portion 50b also defines a body shoulder 50d.
In FIG. 1 it will be seen that a tubular sleeve 114 is provided that has an upper ringed shaped end surface 114 and lower end surface 114b. The sleeve has an exterior surface 114c of cylindrical shape, and a bore 114b extending longitudinally through the sleeve. The exterior surface 114c has a pair of upper recesses 114e formed in the exterior surface 114c thereof as well as a pair of lower circumferentially extending recesses 114f. The upper recesses 114e serve to support a pair of resilient sealing rings 116, and the lower recesses similarly support a pair of lower sealing rings 118. In FIG. 1 it will be seen that the sleeve 114 is so disposed that the lower portion thereof extends into the bore extension 50c, with the lower sealing rings 118 sealingly engaging the bore extension 50c, with the lower end 114b of the sleeve 114 resting on the body shoulder 50d of the tubing hanger C. The upper portion of the sleeve 114 is disposed in the enlarged cylindrical end portion 112a of the bore 112 defined in the mounting flange 20, with the upper sealing rings 116 sealingly engaging the surface defining the enlarged cylindrical end portion 112a.
When it is desired to separate the components of the well head assembly A-1 the first electrical conducting cartridge E is moved outwardly to the position shown in FIG. 6 relative to the well head member B. The indexing device K is moved outwardly to the extent that it is free of the tubing hanger C. The upper rods 16 are now rotated in a direction to move outwardly free of the tubing hanger C. The fastening means 24 are now removed which permits the christmas tree array of valves 28, mounting flange 20, and sleeve 114 to be moved upwardly and away from the well head member B. The upper threads 50b of the hanger C may be engaged by a threaded member (not shown) on which an upward force may be exerted to lift the tubing hanger C above the well head member B, together with the tubing string 52, where connector J and cable H may be disconnected from the tubing hanger.
The casing hanger 40 may have the interior threaded portion 40d engaged by a threaded member (not shown) on which an upward force may be exerted to lift the casing hanger above the well head member D. The inner casing 42 will move upwardly with the casing hanger 40. Prior to the casing hanger 40 being moved upwardly the lower rods 18 are rotated to move them outwardly from engagement with the retaining ring 96. As the casing hanger 40 is moved upwardly in the well head member B, the retainer 96 will also be moved upwardly therewith.
When it is desired to reassemble the components, the procedure above described is simply reversed, and alignment of the first cartridge E with the second cartridge D being achieved by use of the indexing means K. The cable H will normally be banded to the tubing string 52 as the latter is lowered into the well, and sufficient slack is left in the cable H to permit the tubing hanger C to be moved above the well head member B without the cable H having a strain exerted thereon.
A second form A-2 of the well head assembly is shown in FIG. 2 and FIGS. 7 to 15 inclusive, and differs from the first form A-1 in that the second electrical conducting cartridge D' is removably supported within the tubing hanger C'. Elements of the second form A-2 that are common to the first form A-1 are identified by the numerals and letters previously used, but with primes being added thereto.
The second electrical conducting cartridge D' has a body 198 that is preferably defined by first and second rectangular blocks 200 and 202 formed from "Micarta" or a like material. The second block 202 has prongs 200a projecting upwardly therefrom as shown in FIG. 7 that engages recesses 200a formed in the first block 200. When the prongs and recesses are in engagement the side surfaces 200b and 202b of the blocks 200 and 202 are in abutting contact as shown in FIG. 8. A conventional fixture 206 rotates the blocks 200 and 202 as shown in FIG. 8 on a center line 204, and by a cutting member (not shown) the blocks are formed to have a cylindrical upper body portion 208. Also during the cutting operation a pair of grooves 210 are formed in the upper cylindrical body portion 208. The rotating fixture 206 is now moved to rotate the blocks on an off centered line 212, and by a cutting operation the body 198 has a lower cylindrical body portion 212 formed therein as well as a pair of circumferantially extending grooves 216.
A drill 218 as shown in FIG. 10 is moved inwardly from the lower end 214a to form a first upwardly extending passage 220 in the body 198, and thereafter the drill is used to form a transverse passage 222, or as may be seen in FIG. 10 and more clearly in FIG. 12. The upper end 208b of the body 198 has a tapped recess 224 extending downwardly therein.
A cylindrical recess 222a is formed in the first and second blocks 200 and 202 at the outer end of the second passage 222. The first and second blocks 200 and 202 are now separated, and a body 226 defined by an electrical insulating material such as epoxy or the like is provided that is of such shape as to fill all of the first passage 220 and second passage 222 when the blocks are in the form shown in FIG. 15 and have the surfaces 200b and 202b in abutting contact.
The body 226 has a number of L-shaped electrical conductors 228 supported therein in spaced relationship. The conductors 228 have first engageable means, preferably in the form of prongs 230, that extend outwardly from the portion of the body 226 disposed in the first passage 222. The conductors 228 have second engageable means, preferably in the form of sockets 232, embedded in the body 226 as shown in FIGS. 14 and 15.
The side surfaces 200b and 202b are now bonded together in abutting contact by an adhesive or the like to define the first electrical conducting cartridge D' as may be seen in FIG. 15 which has the cylindrical body 198 defined by the shaped blocks 200 and 202. The prongs 230 are shown in FIG. 13. Likewise, the sockets 232 are illustrated in FIG. 14.
In FIGS. 2 and 15 it will be seen that a first bore 234 extends downwardly from the top 44' of the tubing hanger C' and develops into an off centered downwardly extending second bore 236, which first and second bores at their junction define a transverse crescent shape body shoulder 238. The second bore 236 at the lower end thereof terminates in a body shoulder 240 from which a bore extension 242 extends towards the bottom 46' of the tubing hanger C. The body shoulder 238 as shown in FIG. 15 is situated below the second passage 68'.
The cartridge D' may now be slid downwardly in the first bore 234 as shown in FIG. 15, with the lower portion of the cartridge being disposed in the second bore 236, and the second passage 222 being axially aligned with the passage 60a' formed in the tubing hanger C'. The grooves 210 and 216 support sealing rings 210a and 216a that removably seal with the first bore 234 and second bore 236 as shown in FIG. 15. A sealing ring 244 rests on the upper surface 208b of the body 198 as may be seen in FIG. 15.
A first cartridge E' is provided that has the same general structure as the first cartridge E, but with the sockets 68 of the first cartridge being omitted. The sockets 66d of first cartridge E are replaced in first cartridge E' as may be seen in FIG. 15 by electrical conducting prongs 246 that may slidably engage the sockets 232. When the tubing hanger D' is rotated relative to the well head member B' as shown in FIG. 15 where the cylindrical passage 60a' is co-axially aligned with the transverse bore 32', the first cartridge E may be moved inwardly through the transverse bore 32' for the prongs 246 to engage the sockets 232. The forward portion of the first electrical conducting cartridge E', will then be disposed in the cylindrical end section 60a' and extend into the cylindrical recess 222a as shown in FIG. 15. The collar G' when screwed inwardly to the position shown in FIG. 15 compresses the sealing rings 74' into sealing engagement with the first electrical conducting cartridge E' and the well head member B'.
The second electrical conducting cartridge D' is removably held in the seated position shown in FIG. 15 in the tubing hanger C' by a cylindrical plug 248 that has a top 250, bottom 252 and sidewall 254. Plug 248 has threads 254a formed on the upper portion of the sidewall 254, which threads engage the threads 234a in the tubing hanger C'. A non-circular wrench engageable cavity 250a extends downwardly in the plug 248 to permit the plug to be rotated and removably disposed in the position shown in FIG. 15 where it exerts a downward force on the sealing ring 244 and the second electrical conducting cartridge C'. Sidewall 254 has a pair of spaced circumferantially extending grooves 256 formed therein that support sealing rings 256a that seal with the first bore 234.
An internally threaded cavity 256 extends downwardly in second electrical conducting cartridge D' from the end surface 208b, with the cavity being engageable by a threaded rod (not shown) to lift the second cartridge from the tubing hanger C' after the plug 248 and sealing ring have been removed from the tubing hanger C'. The connector J' shown in FIG. 15 is of the same structure as connector J. Connector J' removably engages the prongs 230, and when so engaged supplies electric power from cable F' to cable H'.
The tubing string 52' in FIG. 2 is illustrated as being a normally open valve 260 interposed therein, which valve is placed in the closed position by a pressurized fluid being applied to the port 260a therein. A source of pressurized fluid 264 is provided for actuating the valve 260 when it is desired to place the latter in a closed position. Tubing 262 extends upwardly from the port 260a to engage a recess 266 that extends upwardly from the bottom surface 46' of the tubing hanger C' as shown in FIG. 2.
The tubing hanger C' has an upwardly extending bore 268 formed therein in communication with the recess 266, and the upwardly extending bore being intersected by a horizontal bore 270. The two sealing rings 54a' and 56a' as may be seen in FIG. 15 pressure contact the interior surface of the well head member B' and cooperate with the well head member and the surface 12' of the tubing hanger to define a thin annulus shape confined space 276 therebetween.
The horizontal bore 270 on the outer end thereof develops into a cylindrical cavity 272 that is co-axially aligned with a second transverse bore 274 formed in the well head member B', with the cavity and second bore 274 being co-axially aligned when the first electrical conducting cartridge E' is in engagement with the first electrical conducting cartridge C' as shown in FIG. 2. The second bore 274 has threads 274a defined on the outer portion thereof.
A tubular member 278 is provided that has a cylindrical head 280 on the inner end thereof as illustrated in FIG. 2, which head has a groove 282 extending circumferentially there around and in which a sealing ring 284 is mounted. An externally threaded tubular collar 286 is shown in FIG. 2 that threadedly engages the threads 274a, and the collar having a wrench engageable outer end 288. The outer end of the tubular member 278 is connected to a length of tubing 290 that extends to the discharge port of a valve 292 which valve is normally in the closed position, but is adapted by hand operated means (not shown) to be moved to the open position. The fluid inlet to the valve 292 is connected by tubing 294 to the source of pressurized fluid.
Sealing rings 284a encircle the portion of the tubular member 278 between the head 280 and the inner end of the collar 286.
When the collar is rotated in an appropriate direction the sealing rings 284a are compressed, and are forced into pressure sealing contact with the head 280, the surface defining the cavity 272 in the tubing hanger C', and the surface of the well head member B' that defines the bore 274. In an emergency, the valve 292 may be placed in the open position to permit pressurized fluid to flow from the source 264 to the valve 260 to close the same, and prevent undesired fluid from discharging upwardly through the bore 50' to the christmas tree assembly of valves 28'.
The well head assembly A-2 as above described supplies electric power to the cable H' in the same manner as the assembly A-1, but differs from the assembly A-1 in that the second cartridge C' is removable from the supporting tubing hanger C'.
In both the forms A-1 and A-2 of the well head assembly, the well head assemblies 28 and 28' are mounted directly thereon and accordingly have a minimum vertical profile, the tubing strings 52 and 52' are supported at centered positions within the well bore, and electric power is supplied to the well head assemblies below the upper ends thereof.
The use and operation of the invention has been described previously in detail and need not be repeated. | A well head assembly that terminates on the upper end in a horizontal mounting flange on which the flange of a christmas tree array of valves may be sealingly mounted to control the flow of fluid from the well associated therewith, and the well head assembly including slidably engageable first and second electrical conducting cartridges below the mounting flange for supplying electric power to a number of insulated electrical conductors that extend downwardly in the well to an electric motor driven down hole pump or other electrical apparatus. The positioning of the christmas tree array of valves at a minimum height relative to the well head is most desirable in those situations where a number of wells are drilled close together, such as on an off shore island, and equipment must be periodically moved over the array of valves for maintenance or drilling purposes. The well head assembly also includes means for pressurizing a normally open pressure actuated valve in communication with a tubing string operatively associated with the assembly to place the valve in a closed position. Closing of the valve eliminates the possibility of continued undesired fluid discharge from the well in the event of a catastrophe or malfunctioning of the well. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to ultraviolet light curable compositions that form high gloss decorative metallic appearance on various substrates.
BACKGROUND OF THE INVENTION
[0002] Bright metallic finishes are used in applications requiring a high degree of reflection over wide wavelengths. These finishes are typically used in decorations and ornamentations for aesthetic value. Packages with these brilliant metallic finishes outperformed those without metallic enhancement in 80% of the test cases in marketing study (Brand Packaging, Jan. 1, 2004).
[0003] It is often desirable to spot metallize (also known as spot application) a portion of a package. The metallic finishes are typically transferred from a two-dimensional sheet or web of metallized films, metallized papers or metallized foil onto the packages. However, creating spot metallization from the two-dimensional sheet creates wastes and additional steps. In one method, the metallized film is hot-stamped on designated areas of the package. In another method, the entire surface of the package is first covered with the two dimensional metallized film, and then portions of the metallic area is covered with a layer or layers of high opacity white ink to coat over the metallized portions. Both of these methods increase the overall cost, time and waste.
[0004] Alternatively, metallic particles are incorporated in a solvent-based binder system. However, solvent-based metallic coatings are not preferred in high production and large scale operations because they must be physically dried or heat cured, often incurring large amounts of energy, time and cost. Mills (U.S. Pat. No. 4,233,195) teaches a metallic ink composition; however, this composition is a pasty solvent-based ink that must be applied through an offset ink station at 300° F. heated roller to create a metallic paper. Kruger et. al., (US 2008/0131383), describe an in-situ solvent-based resin binder system that includes physical vapor deposition aluminum flake and a leafing additive to form artificial nails; however, the resin binder system must be physically dried to form the metallic effects. Volt et. al., (US 2010/0064938), describe a water polymer and/or organic binder solvent system containing silver-dollar leafing aluminum and an organofunctional siliane to create a high brilliant metallic finish. Again, this is a solvent and water based system, which must undergo a drying process.
[0005] Maintaining high gloss for metallic surfaces can be challenging in a water based system. Low et al., (US 2010/0151139) describe an aqueous polyurethane based metallic coating that can be physically and/or thermally curable with PVD aluminum flakes. However, the gloss level is less than 104 gloss units (GU), which is less than high brilliant finish (typically 190 GU or higher as measured with a 60 degrees gloss meter).
[0006] While a system without physical drying or thermal curing is desirable, a balance of fast cure speed and shelf-stability is a challenge, especially for aluminum and copper metal flakes. Ikeya et al., (U.S. Pat. No. 7,837,777) describe the use of nitrocellulose to provide shelf stability and to stop premature gellation for a surface treated metal flakes in a UV-curable metallic inks, but nitrocellulose fails to contribute to cure speed enhancement.
[0007] To date, only a limited number of combinations of components are known to create a high gloss metallic effect for UV curable composition. Krohn (U.S. Pat. No. 6,805,917) teaches a UV-curable system that utilizes Novolac epoxy acrylate with isobonyl acrylate and isobonyl methacrylate. A flow additive, ethyl acrylate/2-ethylhexyl acrylate copolymer (Modaflow), is further added to metallic pigments. While the cure speed of the composition is adequate due to high initiator loading, Krohn is silent as to the gloss measurement of the finish.
[0008] There remains a need in the art for energy-efficient and environmentally-friendly metallic compositions, which are UV-curable in high speeds, shelf-stable, and can be cured to high gloss levels. The current invention fulfils this need.
BRIEF SUMMARY OF THE INVENTION
[0009] It has been discovered that the instant UV-curable metallic compositions provide a high gloss level of metallic finish, retain the gloss level over the storage duration, and maintain press and shelf stability, while maintaining cure speeds similar to those of non-metallic UV-curable compositions. The metallic finishes of the instant cure compositions are similar in gloss (brilliancy/reflectivity) to those of foil-like finishes.
[0010] In one aspect, the UV curable metallic decorative composition comprises (a) a plurality of a leafing metallic pigment flakes; (b) an acrylate oligomer and/or an acrylate monomer; (c) a initiator or mixture of initiators; and (d) a cure accelerator that is a tertiary amine with a structure of:
[0000] R 1 R 2 N—Y
[0000] wherein R 1 and R 2 are independently, an aliphatic and/or aromatic substituent, and Y is an electron withdrawing substituent. In one embodiment, Y is a substituted benzene substituent with an electron withdrawing substituent. In another embodiment, Y is a benzoate.
[0011] In another aspect, the cured UV curable metallic decorative composition has a gloss level of above 190 GU at 60 degrees angle, as measured in accordance with ASTM D523, D2457, DIN 67530 or JIS Z8741. In another embodiment, the cured UV curable metallic decorative composition has a gloss level of above 65 GU at 20 degrees angle, as measured in accordance with ASTM D523, D2457, DIN 67530 or JIS Z8741.
[0012] Another aspect is directed to a UV-curable top coating composition that overlays at least a portion of the cured UV curable metallic decorative composition. In one embodiment, the UV-curable top coating composition comprises (1) an acrylate oligomer; (2) an acrylate monomer; (3) a photoinitiator or a mixture of initiators (4) a conventional cure synergist; and (5) an additive selected from the group consisting of wetting agent, defoamer, slip agent, stabilizer, optical brightener, dye, and pigment dispersion. In another embodiment, the UV-curable top coating composition is a water-based top coating, comprising (1) an acrylate oligomer that is water-dispersible, water-emulsified acrylate oligomer or polymer; (2) a water dispersible initiator; (3) an additive selected from the group consisting of wetting agent, defoamer, antioxidant, optical brightener, dye, and pigment dispersion; (4) an optional water dispersible or water soluble monomer.
[0013] Another aspect is directed to an article comprising a cured UV-curable decorative coating composition on a substrate.
[0014] In another aspect, the invention is directed to an article comprising a cured UV curable metallic decorative coating composition and a cured top coating composition, wherein the cured metallic decorative coating composition is coated on at least a portion of the surface of a substrate, and the cured top coating is coated on at least a portion of the surface of the cured metallic decorative coating surface.
[0015] In another aspect, the invention is directed to an article comprising a cured UV curable metallic decorative coating composition on at least a portion of the surface of a substrate, and a cured top coating that is coated on at least a portion of the surface of the cured UV curable metallic decorative coating composition. The UV curable top coating may be applied in multiple layers, where some layers include a colorant.
[0016] Yet another aspect is directed to a method of fabricating a metallic-finished article. The steps include (1) applying a UV-curable metallic composition on a substrate, (2) curing the UV-curable metallic composition. Optional steps include (3) applying a UV curable top coating with a colorant to at least a portion of the surface of the cured UV curable metallic composition and (4) curing or drying the colorant layer. In another embodiment, additional optional steps include (5) applying a second UV-curable top coating composition on at least a portion of the surface of the cured metallic composition and/or the surface of the cured colorant layer; and (6) curing the second UV-curing the top coating composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIGS. 1A and 1B show cross sectional views of spot coating substrate with UV metallic coating, protective top coating and optional color treatments. FIG. 1C shows the method of fabricating a metallic-finish article.
[0018] FIG. 2 shows a conventional hot foil stamping techniques utilized in spot metallization.
[0019] FIG. 3 shows a conventional foil film lamination technique creating spot metallization effect.
[0020] FIG. 4 is a photographic image of cured UV curable metallic compositions.
DETAILED DESCRIPTION OF THE INVENTION
[0021] All references cited are incorporated herein.
[0022] The UV curable metallic decorative composition comprises (a) a plurality of a leafing metallic pigment flakes; (b) an acrylate oligomer and/or an acrylate monomer; (c) an initiator or mixture of initiators; and (d) a cure accelerator that is a tertiary amine with a structure of:
[0000] R 1 R 2 N—Y
[0000] wherein R 1 and R 2 are independently, an aliphatic and/or aromatic substituent, and Y is an electron withdrawing substituent.
[0023] In one embodiment, the cured UV curable metallic decorative compositions have a 60 degree gloss level greater than 190 GU, more preferably greater than 200 GU, measured in accordance with ASTM D523, ASTM D2457, DIN 67530 or JIS Z8741. In another embodiment, the cured UV curable metallic decorative compositions have a 20 degree gloss level greater than 65 GU, more preferably greater than 70 GU, measured in accordance with ASTM D523, ASTM D2457, DIN 67530 or JIS Z8741. The gloss level of the cured UV curable metallic decorative compositions rival those of conventional metallic finishes, including foil board, metallized paper, hot foil stamping, and the like, which also have a gloss level greater than 190 GU.
[0024] The basis for the bright metallic finishings and coatings are metal particles, including, for example aluminum, zinc, copper, sliver, gold, nickel, titanium, and stainless steel and alloys of these metals. Aluminum is often chosen for silver metallic finishes and coatings for its excellent reflectance over a wide optical spectrum, including from UV to infrared. Similarly, copper and copper alloys are typically chosen for gold metallic finishes and coatings for their excellent reflectance. The highly reflective particles include powders, flakes and/or platelets (hereinafter referred to as “flakes”). The metal particles generated from the atomization process of molten metal may be further formed by conventional ball milling process to form shape known in the industry as “cornflake,” “silver dollar” and “mini-silver dollar.”
[0025] Aluminum flakes can also be generated by physical vapor deposition PVD (Physical Vapor Deposition) or VMP (Vacuum Metallized Process). Aluminum flakes formed by these means are thinner, have higher brilliance, and have higher reflectivity than those made by the conventional ball mill process. Also, these flakes form a micron size thin platelet shape and their packing structure is defined by x-ray diffraction method to be different from flakes form by conventional methods, as described in US 2010/0047199A1. While higher throughput of such PVD aluminum flakes makes commercial production feasible (US 2004/0146642), the resulting aluminum flakes are predominantly supplied in a solvent-based dispersion, and used for solvent-based metallic coating where physical drying and/or heat curing is still required.
[0026] The surface treatment further determines the behavior of the metal particles/flakes distribution, as either leafing or non-leafing, in bulk matrix. Typical surface treatments include fatty acids, phosphorous compounds, silianes, and aliphatic amines for metallic pigments. Surface treatment of metal flakes with stearic acid, for example, produces metallic flakes with high interfacial surface tension and hinders the binder from wetting out, and as a result, leafing metallic flakes rise to the surface during the drying process and form a scale-like, shinny metallic finish. Non-leafing pigments are created, for example, with the use of an oleic acid during the milling process. The metal flakes can be “wet out” by the binder, and therefore, are uniformly distributed in the dried or cured matrix. The non-leafing metallic flakes result in a “dull,” non-shinny metallic finish. Various treatments to form leafing and non-leafing pigments are described in U.S. Pat. No. 4,629,512, U.S. Pat. No. 4,486,225, US 2004/0226480, US 2010/0269733, U.S. Pat. No. 4,565,716, US 2011/0094412A1, U.S. Pat. No. 7,837,777 and Metallic Effect Pigments-Fundamentals and Applications,” Vincentz Network, ISBN 3-87870-171-3 (2006).
[0027] Preferred metal particles include leafing aluminum flakes, mixtures of PVD leafing aluminum flakes of various flake thickness and treatments, mixtures of PVD leafing and conventional ball-mill leafing aluminum flakes for silver metallic finishes. Preferred metal particles also include leafing copper and/or copper alloy flakes, for gold metallic finishes.
[0028] The UV curable metallic decorative compositions contain from about 0.1 to about 20 wt % of metallic flakes, more preferably from about 0.5 to about 15 wt %, and even more preferably from about 1 to about 12 wt %, based on the total solid weight of the composition.
[0029] Acrylate monomers useful for the UV-curable metallic compositions include mono-functional, di-functional, tri-functional and multi-functional acrylate monomers. Exemplary mono-functional acrylate monomers include, but not limited to, octyl acrylate, decyl acrylate, tridecyl acrylate, 2-phenoxyethyl acrylate, isobornyl acrylate, 2(2-ethoxyethoxy)ethyl acrylate, nonylphenoe acrylate, ethoxylated nonylphenol acrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, aliphatic acrylate (Ebecryl 113, Cytec Industries Inc.), caprolactone acrylate, lauryl acrylate, cyclic trimethylolpropane formal acrylate, and the like. Exemplary di-functional acrylate monomers include, but not limited to, tripropylene glycol diacrylate, dipropylene glycol diacrylate; 1,6 hexanediol diacrylate; ethoxylated hexanediol diacrylate; 1,3-biutanedial diacrylate; 1,4-butanediol diacrylate; neopentyl glycol diacrylate; propoxylated neopentyl glycol diacrylate; diethylene glycol diacrylate; triethylene glycol diacrylate; tetraethylene glycol diacrylate; polyethylene glycol-200-diacrylate; polyethylene glycol-400-diacrylate; polyethylene glycol-600-diacrylate; 3-ethoxylated bisphenol-A diacrylate; 4-ethoxylated bisphenol A diacrylate; 10-ethoxylated bisphenol-A diacrylate; and the like. Exemplary tri-functional acrylate monomers include, but not limited to, trimethyol propane triacrylate, ethoxylated trimethyol propane triacrylate, 6-ethoxylated trimethyol propane triacrylate, 9-ethoxylated trimethyol propane triacrylate, 15-ethoxylated trimethyol propane triacrylate, 20-ethoxylated trimethyol propane triacrylate, propoxylated trimethylol triacrylate, propoxylated glyceryl triacrylate, pentaerythritol triacrylate, and the like. Exemplary multi-functional acrylate monomers include, but not limited to, pentaerythritol tetraacrylate, di-trimethylol propane tetraacrylate, di-pentaerythritol pentaacrylate, and the like.
[0030] Acrylates containing carboxylic acid (such as acrylic acid, e.g., CD9051, CD9051 from Sartomer; UCB Ebecryl 168, Ebecryl 170 from Cytec Industries Inc.), tertiary amines that contains electron donating substituents on the nitrogen (e.g., Ebecryl P104, P105, Ebecryl 7100 from Cytec Industries Inc.) and metallic acrylates (e.g., SR633, SR635, SR636, SR705, SR706, SR708, SR709, SR9016 from Sartomer) should be avoided since they would tarnish aluminum and copper metallic flakes.
[0031] Preferred acrylate monomers for UV-curable metallic compositions include 2-phenoxyethyl acrylate, isobornyl acrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, aliphatic acrylate (Ebecryl 113 from Cytec Industries, Inc.), tripropylene glycol diacrylate, dipropylene glycol diacrylate; 1,6 hexanediol diacrylate, ethoxylated hexanediol diacrylate; 1,4-butanediol diacrylate; neopentyl glycol diacrylate; propoxylated neopentyl glycol diacrylate; 4-ethoxylated bisphenol A diacrylate; trimethyol propane triacrylate; ethoxylated trimethyol propane triacrylate; propoxylated glyceryl triacrylate, pentaerythritol triacrylate, di-trimethylol propane tetraacrylate.
[0032] The UV-curable metallic compositions further comprise an acrylate oligomer with epoxy, polyester, urethane or acrylic backbones. Preferably, this acrylate oligomer component is an acrylate terminated oligomer with film-forming properties and does not contain any carboxylic acid, amine, and silicones functional groups. For example, and without limitation, the oligomer of this embodiment can be an acrylate oligomer such as a polyester acrylate oligomer with a plurality of acrylate functional group per oligomer molecule. In some embodiments, the acrylate oligomer can have two to six acrylate sequences per oligomer molecule.
[0033] Examples of epoxy acrylate oligomers include, but are not limited to, bisphenol-A epoxy diacrylate (Ebecryl 3700, Ebecryl 3720 from Cytec Industries Inc.; CN120, CN104 from Sartomer), modified bisphenol-A epoxy diacrylate (Ebecryl 3701 from Cytec Industries Inc.), epoxy acrylate (CN121, CNUVE151 from Sartomer), UVE2200 epoxy acrylate (from Polymer Technologies, Ltd.) and the like. Examples of acrylic acrylate oligomers include, but not limited to, CN2285 and CN549 from Sartomer. Typically, epoxy acrylate oligomers are available in a mixture with an acrylate monomer, wherein the oligomer is the major (typically greater than 50 weight percent) component of the mixture. Examples of polyester acrylate oligomers include, but are not limited to, CN292, CN293, CN704, CN710, CN2200, CN2203, CN2270, CN2262, CN2283, and CN2298 from Sartomer; and Ebecryl 40, Ebecryl 810 Ebecryl 885, Ebecryl 888 from Cytec Industries Inc.; and the like. Examples of urethane acrylate oligomers include, but are not limited to, aromatic urethane acrylate (Ebecryl 4827, Ebecryl 4849 from Cytec Industries Inc.), aromatic urethane hexa-acrylate (Ebecryl 220), aliphatic urethane diacrylate (Ebecryl 230, Ebecryl 270, Ebecryl 284, Ebecryl 4883, Ebecryl 8210, Ebecryl 8301 from Cytec Industries Inc.; CN9009, CN9024, CN966, from Sartomer. One example of acrylic Acrylate oligomer is Ebecryl 745 from Cytec Industries Inc., and CN704, CN711, CN821, CN822 from Sartomer.
[0034] Preferred acrylate oligomer components include bisphenol-A epoxy diacrylate, UVE2200 modified epoxy acrylate, and various monomer dilutions thereof and.
[0035] Also preferred are polyester acrylate oligomers including CN2203, CN2262, CN2283, CN2298, Ebecryl 40, Ebecryl 810; aromatic urethane acrylate Ebecryl 4849, Ebecryl 220; aliphatic urethane diacrylate, Ebecryl 8210, and various monomer dilutions thereof.
[0036] The UV-curable metallic compositions further comprise a photoinitiator. One or mixtures of photoinitiators may be used in the UV-curable metallic compositions to produce fully cured compositions. Examples of photoinitiator include, but not limited to, benzophenone, 4-methyl benzophenone, liquid benzophenone (eutectic mixture of benzophenone and methyl benzophenone), 4-phenylbenzyophenone, methyl-2-benzoylbenzoate, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxy-cyclohexyl-phenyl-ketone, a mixture benzophenone and 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 500 from Ciba); 2,2-dimethoxy-2phenyl acetophenone/benzyldimethyl ketal; methylbenzoylformate; 2-hydroxy-1[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone; dimethylhydroxy acetophenone; 1-[4-(1,1-dimethylethyl)phenyl]-2-hydroxy-2-methylpropan-1-one (Chivacure 2173 from Chitec. Technology); 2,4,6-trimethylbenzoyl phosphine oxide; ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate; phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide; a mixture of 2,4,6-trimethylbenzoyl phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone (Daracur 4265 from Ciba); a 25/75 blend of bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone; a 20/80 blend of phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide and proprietary phosphine derivative; a mixture of oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester; oligo(2-hydroxy-2-methyl-1-(4-(1-methyl vinyl)phenyl) propanone) (Esacure one from Lamberti); oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] (Esacure KIP150 from Lamberti); 1-propanone, 1-[4-[(4-benzoylphenyl)thio]phenyl]-2-methyl-2-[(4-methylphenyl)sulfonyl] (Esacure 1001 from Lamberti); poly {1-[4-(phenylcarbonyl)-4′-(methyldiphenylsulphide)]ethylene} (Speedcure 7003 from Lambson); a mixture of: 1,3-di({α-2-(phenylcarbonyl)benzoylpoly[oxy(1-methylethylene)]}oxy)-2,2-bis({α-2-phenylcarbonyl)-benzoylpoly[oxy(1-methylethylene)]}oxymethyl) propane and {α-2-(phenylcarbonyl)benzoylpoly(oxyethylene)-poly[oxy(1-methyl-ethylene)]-poly(oxyethylene)}2-(phenylcarbonyl)benzoate (Speedcure 7005 from Lambson); poly{1-[4-(phenylcarbonyl)phenyl]ethylene} (Speedcure 7006 from Lambson); poly{1-[4-(phenylcarbonyl)-4′-(chlorophenyl)]ethylene} (Speedcure 7020 from Lambson); polymeric benzophenonic derivative (Genopol BP-1); and mixtures thereof.
[0037] In conjunction with the above mentioned initiators, cure initiators designed for pigmented UV systems may be used in the UV-curable metallic compositions. Exemplary initiators for pigmented system include isopropylthioxanthone; 2,4-diethylthioxanthone; 1-chloro-4-propoxythioxanthone; bis(p-(N,N-dimethylamino)phenyl)ketone (Michler's ketone); 2-benzyl-2N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone; 2-(4-Methylbenzyl)-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone; 1-butanone, 2-(dimethylamino)-1-[4-[(2-hydroxyethyl)methylamino]phenyl]-2-(phenylmethyl) (R-Gen 988 form Chitec); 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino propan-1-one; 4-(p-tolythio)benzophenone; 1,3-di({α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]}oxy)-2,2-bis({α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]}oxymethyl) propane (Speedcure 7010 from Lambson,); polybutyleneglycol bis(9-oxo-9H-thioxanthenyloxy)acetate (Genopol TX-1 from Rahn Ag); diester of carboxymethoxy thioxanthone and polytetramethyleneglycol 250 (Omnipol TX from IGM Resins); and mixtures thereof.
[0038] Preferred initiators includes benzophenone; 2-hydroxy-2-methyl-1-phenyl-1-propanone; 1-hydroxy-cyclohexyl-phenyl-ketone; 2,2-dimethoxy-2-phenyl acetonephenenone/benzyldimethyl ketal; 2,4,6-trimethylbenzoyl phosphine oxide; ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate; phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide; a 20/80 blend of phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide and various phosphine oxide derivatives; a mixture of oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester; isopropylthioxanthone; bis(p-(N,N-dimethylamino)phenyl)ketone (Michler's ketone); oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] (Esacure KIP150 from Lamberti); 1-propanone, 1-[4-[(4-benzoylphenyl)thio]phenyl]-2-methyl-2-[(4-methylphenyl)sulfonyl] (Esacure 1001 from Lamberti); 2-(4-Methylbenzyl)-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone; polybutyleneglycol bis(9-oxo-9H-thioxanthenyloxy)acetate (Genopol TX-1 from Rahn Ag); diester of carboxymethoxy thioxanthone and polytetramethyleneglycol 250 (Omnipol TX from IGM Resins) and mixtures thereof.
[0039] The UV-curable metallic compositions further comprise a cure accelerator. The cure accelerator of the UV-curable metallic composition is a tertiary amine with a structure of:
[0000] R 1 R 2 N—Y
[0000] wherein R 1 and R 2 are independently, an aliphatic and/or aromatic substituent, and Y is an electron withdrawing substituent. In one embodiment, Y is a substituted benzene substituent with an electron withdrawing group. In another embodiment, Y is a benzoate.
[0040] Preferred accelerators include ethyl 4-(dimethylamino)benzoate, 2-ethylhexyl-4-(dimethylamino)benzoate, ethyl 2-(dimethylamino)benzoate, n-butoxyethyl 4-(dimethylamino)benzoate; poly[oxy(methyl-1,2-thanediyl)], α-[4-(dimethylamino)benzyl-ω-butoxy (Speedcure PDA from Lambson); poly(ethyleneglycol)bis(p-dimethylamino benzoate) (Omipol ASA from IGM Resin); a mixture of 1,3-di({α-4-(dimethylamino)benzoylpoly[oxy(1-methylethylene)]}oxy)-2,2-bis({α-4-(dimethylamino)-benzoylpoly[oxy(1-methylethylene)]}oxymethyl) propane and {α-4-(dimethylamino)benzoylpoly(oxyethylene)-poly[oxy(1-methylethylene)]-poly(oxyethylene)}4-dimethyl-amino)benzoate (Speedcure 7040 from Lambson); polymeric aminobenzoate derivative (Genopol AB-1 from Rhan USA); and mixtures thereof.
[0041] Conventional tertiary amine synergists differ from the tertiary amine cure accelerators. The conventional tertiary amine cure synergists contain an electron donating substituent on the nitrogen, whereas the tertiary amine cure accelerators contain an electron withdrawing substituent. Metal flakes are typically pre-treated with a surface treating agents such as amines, fatty acids, phosphorous compounds, and/or siliane. Thus, care should be taken to avoid further adding the aforementioned surface treating agents to prevent any adverse effect to the metals. Typically, the addition of a conventional tertiary amine synergist, such as methyldiethanol amine (MDEA), triethanol amine (TEOA), and amine acrylates (such as Ebecryl P104, Ebecryl P105, Ebecryl 7100 from Cytec Industries Inc. or their equivalent) to aluminum or copper containing UV curable composition negatively affects the metal brilliance and/or its stability (gels the composition, immediately or within several days), rendering the UV curable composition unusable. It is surprising that the addition of particular tertiary amine cure accelerator as described above, to a UV curable composition filled with aluminum or copper accelerates the cure speed, retains the high gloss finish (greater than 190 GU measured at 60° measured in accordance with ASTM D523, ASTM D2457, DIN 67530 or JIS Z8741) and allows for shelf-stability for at least several months. Without being bound to any particular theory, it is believed that the electron withdrawing group of the cure accelerator distributes the lone electron pair of the nitrogen in the cure accelerator, preventing metal oxidation reaction and premature polymerization reaction of acrylate compositions. It is also believed that the hydrogen groups from the adjacent carbon atom (R 1 , R 2 ) enhance cure acceleration of the UV curing process.
[0042] Optional additives such as antioxidants, stabilizers, anti-misting agents, optical brighteners, slip agents such as waxes, fillers, and/or dyes can be added up to about 10 wt % of the curable coating composition. Solvents may also be added as an optional component to achieve a desired viscosity or thickness of the coating composition. Optional solvents such as ethanol, isopropyl alcohol, ethyl acetate, isopropyl acetate, 2-methoxy-1-methylethyl acetate, 1-methoxy-1-propanol, butyl glycol, methyl ethyl ketone, or other suitable solvents can be added to adjust the viscosity for specific application methods or for achieving low coating thickness.
[0043] The UV-curable metallic compositions may be formed by combining the solid and liquid components together. Heat and shear in the mixing can be adjusted to assure a uniform mixture. The viscosities of the compositions can be adjusted with a solvent to suit a particular application method and to obtain a desired application viscosity and thickness. Typically, the desirable viscosity is in the range of about 10 centipoise (cps) to about 100,000 cps at 25 to 40° C.
[0044] Gloss is the attribute of surfaces that causes the appearance to have shiny or lustrous, metallic or matte finish. Gloss effects are based on the interaction of light with the physical properties of the surface. The gloss of a surface can be greatly influenced by a number of factors, for example the smoothness and quality of the substrate, and the amount and type of coating applied. Gloss is measured by shining a known amount of light at a surface at a specific angle and quantifying the reflectance with a gloss meter. The measurement results are related to the amount of reflected light from a black glass standard with a defined refractive index, and not to the amount of incident light. The measurement value for this defined standard is equal to 100 gloss units (GU). Materials with a higher refractive index can have a measurement value above 100 GU.
[0045] The gloss of the cured UV-curable metallic compositions is greater than 190 GU measured at 60 degree with a gloss meter, measured in accordance with ASTM D523, D2457, DIN 67530 or JIS Z8741. With the gloss level greater than 190 GU, the UV-curable metallic composition gloss rivals foil board, metallized paper, and hot foil stamping. In another embodiment, the cured UV curable metallic decorative composition has a gloss level of above 65 GU at 20 degrees, as measured in accordance with ASTM D523, D2457, DIN 67530 or JIS Z8741. Gloss measured from the UV-curable metallic compositions that have been stored, for even up to three months, exceeded 190 GU (measured at 60 degrees, measured in accordance with ASTM D523, D2457, DIN 67530 or JIS Z8741). The UV-curable metallic composition is shelf-stable for at least up to two months, four months, and even up to six months.
[0046] Another aspect is directed to a UV-curable top coating composition that overlays at least a portion of the cured UV curable metallic composition. It is desirable to apply the top coating onto the cured surfaces to avoid disturbing the leafing effect of the metallic flake. Several layers of the top coating compositions may be applied onto the cured UV curable metallic composition. One of the top coating composition is a colorant layer. Various metallic shades and designs can be created by selecting an appropriate dye, pigments, inks or paints in the top coating composition as the colorant. The colorant is applied onto the surface of the cured UV curable metallic composition to form different metallic shade. For example, application of a colorant with a transparent yellow pigment onto a cured metallic composition made with aluminum flakes is visible as a gold shade on the metallic coating. The colorants can be dried or cured to give a desirable ornamental or design effect. In one embodiment, a second top coating composition overlays the colorant layer.
[0047] The top coating composition may be a non-water-based or a water-based UV curable coating. Depending upon the substrate, appropriate UV-curable top coating compositions are selected. Water-based top coating is preferred for plastic and metal substrates coated with metallic coatings. A better adhesion is formed at the interface of the two coatings with minimal swelling and shrinkage.
[0048] In one embodiment, the UV-curable top coating composition comprises (1) an acrylate oligomer and monomer mixture; (2) a photoinitiator that is compatible with the acrylate oligomer and monomer mixture; and (3) a conventional cure synergist; and optionally, (4) an additive selected from the group consisting of wetting agent, defoamer, antioxidants, stabilizers, anti-misting agents, optical brighteners, slip agents such as waxes, fillers, dye and pigment dispersion. Among others, conventional cure synergists include tertiary amines that contain electron donating substituent.
[0049] In another embodiment, the top coating composition is a water based UV curable coating comprising (1) an acrylate oligomer that is water-dispersible, water-emulsified acrylate oligomer or polymer; (2) a photoinitiator that is compatible with the acrylate oligomer/polymer; and (3) optionally an additive selected from the group consisting of wetting agent, slip agent, stabilizer, optical brightener, defoamer, dye and pigment dispersion; and (4) an optional water dispersible or water soluble monomer. As used herein, acrylate oligomers typically have a weight average molecular weight (Mw) less than about 5,000 and acrylate polymers typically have a weight average molecular weight (Mw) greater than about 5,000. Acrylate oligomers are recognized as having a film forming properties as having higher viscosities than monomers, which typically do not have film forming properties.
[0050] The water-dispersible acrylate oligomer generally contains a water dispersible component, such as a repeating ethoxylated unit —(CH 2 CH 2 O) n — or an ionic functional group. Examples include: LR8765 from BASF, Desmolux XP2587 from Bayer Material Science; UVECOAT 6558 and 6590 from Cytec Industries Inc. Water-emulsified acrylate oligomer or water-emulsified acrylate polymer have the structure of
[0000]
[0000] wherein R 11 is selected from the group consisting of polyester acrylate, epoxy acrylate or polyether acrylate, R 12 is a diisocyanate, R 13 is a diol. The acrylate functional group of R 11 is the reactive site. Water-emulsified acrylate oligomer/polymer include Bayhydrol UV 2282, 2317, VPLS2280, XP2629, XP2649, XP2661, XP2687, XP2689, XP2690, XP2720, XP2721, XP2736, XP2775 from Bayer Material Science; LUX250, LUX260, LUX286, LUX399, LUX430, LUX441, LUX481, LUX515, LUX701, LUX1215 from Alberdingk Boley; UVECOAT 7710, 7730, 7890, 7571, 7578, 7655, 7674, 7689, 7699 polyurethane dispersion from Cytec Industries Inc.; and mixtures thereof.
[0051] Preferred water emulsified acrylate oligomer/polymer dispersions include Bayhydrol XP2649, XP2690, XP2720, XP2736 from Bayer Material Science Material Science; LUX250, LUX260, LUX441, LUX399, and LUX481 from Alberdingk Boley; and mixtures thereof.
[0052] Compatible photoinitators are selected for the water-based UV-curable top coating compositions. The term “compatible” herein is defined as either soluble or dispersible in water diluted acrylate oligomer or water emulsified oligomer/polymer mentioned above without causing curd-like separation.
[0053] Exemplary water-soluble or water-dispersible liquid photoinitiators include 2-hydroxy-2-methyl-1-phenyl-1-propanone, a mixture benzophenone and 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 500 from Ciba), ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate; 50/50 mixture of 2,4,6-trimethylbenzoyl phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone (Daracur 4265 from Ciba); 25/75 blend of bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone (Irgacure 1700); 20/80 blend of phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide and a phosphine derivative (Irgacure 2100 from Ciba); a mixture of oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester (Irgacure 819W from Ciba); 20/80 mixture of phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide with 2-hydroxy-2-methyl-1-phenyl-1-propanone (Irgacure 2022 from Ciba); phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide dispersed in water (50 wt %/50 wt %); oligo(2-hydroxy-2-methyl-1-(4-(1-methyl vinyl)phenyl) propanone) in 75% in TMPEOTA (Esacure One 75 from Lamberti); and mixtures thereof. The photoinitiator may also be pre-dissolved in a miscible solvent, e.g., isopropyl alcohol, or a water dispersible/soluble acrylate monomer, and above mentioned liquid photoinitiator, and can be utilized as a compatible photoinitiator.
[0054] Preferred water-soluble or water-dispersible photoinitiators include 2-hydroxy-2-methyl-1-phenyl-1-propanone, a mixture benzophenone and 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 500 from Ciba); 50/50 mixture of 2,4,6-trimethylbenzoyl phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone (Daracur 4265 from Ciba); 20/80 blend of phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide and a phosphine derivative (Irgacure 2100 from Ciba); 20/80 mixture of phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide with 2-hydroxy-2-methyl-1-phenyl-1-propanone (Irgacure 2022 from Ciba); a mixture of oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester & oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester; ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate; phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide dispersed in water (50 wt %/50 wt %) and mixtures thereof.
[0055] Another embodiment is directed to an article that comprises a substrate with a cured high gloss metallic coating and a cured top coating on top of the metallic coating. The gloss level of this article is greater than 160 GU measured at 60 degree angle in accordance with ASTM D523, D2457, DIN 67530 or JIS Z8741.
[0056] An article comprises, in one embodiment, a cured UV-curable metallic composition on at least a portion of the substrate surface of the article. In one embodiment, and as demonstrated in FIG. 1A , a substrate ( 100 ) is spot coated with a UV metallic coating ( 110 ), and further spot coated with a top coating, which also performs as a protective coating ( 120 ). In another embodiment, and as demonstrated in FIG. 1B , a UV curable top coating with transparent colors (paint/ink) ( 130 ) is spot coated or printed on the UV metallic coating ( 110 ), and a UV curable top coating ( 120 ) is applied over all area. Articles include packaging containers in a variety of shapes and sizes.
[0057] The UV curable metallic compositions allow for various print presses, e.g., offset printing, flexo-printing, gravure printing, silk screen, or inkjet presses, to be aligned to form a single pass process and with minimal or no waste. The UV metallic coating composition is spot applied by a print press and cured, a UV curable top coating with colors (ink/color) is spot applied by the same or different print press and cured, and a UV top coating is spot applied by the same or different print press and cured.
[0058] Unlike the fast curing UV curable metallic composition process, conventional hot foil stamping and foil film lamination techniques operate at lower speeds. Moreover, as shown in FIG. 2B , foil stamping generates waste from the non-transferred foil area. As shown in FIG. 3 , foil film lamination requires portions of the metallic coating to be covered with an opaque white ink to create the spot metallization effect.
[0059] Substrates include paper, plastics, wood, composite wood and metals. The substrates may be in two- or three-dimensional configurations, and in more than one plane. The substrate may be substantially smooth two-dimensional surface or have plurality of surfaces, including rounded edges. For paper substrates, the paper may be a clay-coated or a primer-sealed paper. For plastic substrates, the plastic may be an oriented polypropylene, polystyrene, polyvinylchloride, polycarbonate, polyethylene, polyethylene terephthalate or acrylic.
[0060] In another embodiment, the article is formed by the steps of (1) applying a UV-curable metallic composition on at least a portion of a substrate surface, (2) optionally evaporating the solvent in the UV-curable metallic composition; (3) curing the UV-curable metallic composition.
[0061] In another embodiment, the article is formed by further comprising the steps of (4) applying a UV curable top coating with colorant on at least a portion of the surface of the cured metallic composition; and (5) curing or drying the colorant.
[0062] Yet in another embodiment, the article is formed by further comprising the steps of (6) applying a UV-curable top coating composition on at least a portion of the surface of the cured metallic composition and/or colorant; (7) optionally evaporating the solvent in the UV-curable top coating composition; and (8) UV-curing the top coating composition.
[0063] The UV-curable metallic composition, UV curable top coating composition with colorant, and UV-curable top coating composition may be applied with by various means. Applicators including all conventional application means such as offset printing, lithography printing, gravure printing, digital ink jet printing, flexographic printing, silk-screen printing, pad printing, roller coater, spraying, air brushing, spinning, dipping, and the like, by adjusting the viscosity and rheology of the metallic composition. Heat, alone or with air flow, can be used to evaporate the solvents or colorants in the article formation. Also, ultraviolet radiations, typically ranging from 50 mJ/cm 2 to 5 J/cm 2 , by standard mercury lamp or doped mercury lamp or UV LED can be used to cure the compositions. Depending on the distance and the wavelength, the time for full cure ranges from millisecond to 5 minutes. The addition of the cure accelerator, as specified above, in the UV curable metallic composition, as specified above, allows the metallic composition to cure 20, 30 or even 35% faster than metallic compositions without the cure accelerator. Thus, the addition of the cure accelerator allows the UV curable metallic composition to cure at similar conditions and speeds as those of UV clear coatings and UV pigmented inks/paints.
Examples
[0064] The components of UV-curable metallic compositions are shown in Table 1. The base UV-curable metallic compositions were made by combining the oligomer, photoinitiators, additives, and the first two monomers in a stainless metal cup on a hot plate at 50° C. with saw tooth mixing blade mixer until the mixture dissolved, and then cooling the mixture to room temperature. The remaining components were added and mixed until uniform. Cure accelerators or conventional cure synergist was added in parts per hundred based on the base UV-curable metallic compositions (however, the addition of solid ethyl 4-(dimethylamino) benzoate in Example 3 was added in the heating step). The compositions were then applied onto a clay coated paper with a wire-wound rod #4 bar from Paul N. Gardner Co., Inc.
[0000]
TABLE 1
UV-curable metallic compositions
Com
Com
Component
Ex 1
Ex 2
Ex3
Ex4
Acrylate
Ebecryl 3720TM40 (60%
10.00
oligomer
Bisphenol-A-epoxy
diacrylate oligomer
diluted in 40%
TMPTA monomer)
Acrylate
Trimethylolpropane
26.30
monomer
triacrylate (TMPTA)
monomer
(Cytec Industries Inc.)
di-trimethylol propane
13.80
tetracrylate
Propoxylated (2) Neopentyl
1.20
glycol diacrylate
Photoinitiator
2-hydroxy-2-methyl-1-
4.62
phenyl-1-propanone
1-hydroxy-cyclohexyl-
1.26
phenyl-ketone
2,4,6-trimethylbenzoyl
2.52
phosphine oxide
Additive
Hydroquinone monomethyl
0.12
ether
Irgastab UV-10 (BASF)
0.18
Metal Flake
Leafing PVD aluminum,
40.00
8% dispersed in
Propoxylated (2)
Neopentyl glycol diacrylate
Conventional
methyldiethanol
3 pph
Cure
amine (MDEA)
Synergist
Cure
ethyl 4-(dimethylamino)
2 pph
Accelerator
benzoate (EDB)
2-ethylhexyl-4-
2 pph
(dimethylamino)
benzoate (EHA)
[0065] Table 2 shows the physical properties of the UV-curable metallic compositions, set forth in Table 1.
[0066] Viscosity was measured with a Brookfield Viscometer model LV using #3 spindle, 60 rpm at 25° C. immediately after the compositions were made, unless otherwise stated.
[0067] Metallic coating was applied onto a clay coated paper with a wire-wound rod #4 bar from Paul N. Gardner Co., Inc., unless otherwise stated.
[0068] The gloss reading was taken for draw-down sample cured at 100 mJ/cm 2 . Gloss was measured at 60 and 20 degrees with a BYK micro-Tri-gloss Gloss Meter in accordance with ASTM D523, ASTM D2457, DIN 67530 or JIS Z8741.
[0069] The lowest smear-free cure dosage indicates the amount of cure dosage required to cure the composition to initial gel formation stage. This was determined by incrementally curing the composition at 5 mJ/cm 2 intervals and the cured surface was immediately rubbed with a finger for any smears. The cure dosage (speed) was calibrated with by UVICURE Plus II radiometer.
[0070] The total amount of aluminum was calculated by the amount of aluminum dispersion in total weight of the composition.
[0071] The appearance of the uncured and cured coatings was visually determined.
[0072] The stability of the uncured composition was determined measuring the time it took for the composition to gel or significantly change its viscosity. The uncured composition was left at room temperature in an amber glass bottle.
[0000]
TABLE 2
Physical properties of the UV-curable metallic composition
Com Ex 1
Com Ex 2
EX 3
Ex 4
Brookfield Viscosity (cps) at
520-580
520-580
520-580
500-550
25° C.
20 degree Gloss (Gloss Unit)
77.4-80.9
16.2-20.9
70.9-77.0
69.6-72.6
60 degree Gloss (Gloss Unit)
206-211
62-69
192-197
190-195
Lowest smear-free cure dose,
80
ND
55
60
mJ/cm 2
Aluminum, %
3.2
3.11
3.14
3.14
Appearance (uncured and
Lustrous
Turn grey
Lustrous
Lustrous
cured coating)
immediately
Stability
Stable for
gelled
Stable for
Stable for
greater than
within 48
greater than
greater than
3 months
hours
3 months
3 months
[0073] As shown in Table 2, Examples 3 and 4 had high gloss, low smear free cure dosage, and had shelf stability of greater than 3 months. Also, the lowest smear-free cure dose of the examples 3 and 4 is far lower than the comparative example 1. Thus, the UV curable metallic compositions can cure faster than those without the cure accelerator. Also, the addition of methyldiethanol amine (MDEA), a conventional cure synergist decreased gloss level, tarnished the coating appearance and decreased shelf-stability of the composition.
[0074] As shown in FIG. 4 , Example 3 (left) had higher reflectivity than Comparative Example 2 (right). An object ( 400 ) is place atop of the two coating samples, and the luster or the reflectivity is visible by the shadow ( 410 ). As shown in the photograph, the object's shadow is more visible in Example 3 than in Comparative Example 2.
[0075] For Examples 5-8, a mixture of Ebecryl 3720 TP40, hexanediol diacrylate, ethoxylated trimethylol propane triacrylate, hydroquinone monomethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate and were combined in similar fashion to Examples 1-4. Additions of Modaflow and different leafing aluminums were added as described in Table 3, and the total amount of the composition was 100 wt %. The compositions were coated on clay coated paper using with a wire-wound rod #4 bar from Paul N. Gardner Co., Inc. The gloss reading was taken for sample cured at 100 mJ/cm 2 . The liquid samples are stored in amber glass jars at room temperature for stability monitoring.
[0000]
TABLE 3
UV-curable metallic compositions
Com
Component
EX 5
Ex 6
EX 7
EX 8
Additive #2
Modaflow (Cytec Industries
—
—
—
3.00
Inc.)
Metal Flake #1
Leafing PVD aluminum 20%
12.00
10.00
8.00
12.00
dispersed in ethoxylated
trimethyol propane triacrylate
Metal Flake #2
Leafing conventional aluminum
—
3.00
6.00
—
from ball mill process, 33%
dispersion in propoxylated (2)
neopentyl glycol diacrylate
Cure Accelerator
Ethyl 4-(dimethylamino)
3.00
3.00
3.00
—
benzoate
Total
100.00
100.00
100.00
100.00
[0076] Table 4 shows the physical properties of the UV-curable metallic compositions of Table 3. Table 4 also indicates the percent of PVD aluminum.
[0000]
TABLE 4
Physical properties of the UV-curable metallic composition
EX 5
Ex 6
EX 7
Com EX 8
Brookfield Viscosity (cP)
610-620
360-370
390-400
350-360
20 degree Gloss, points
101-130
112-121
82-87
53.2-58.7
60 degree Gloss, points
276-279
224-238
170-172
110-118
Lowest smear-free cure
60
65
75
—
dose (mJ/cm 2 )
Total Aluminum, %
2.4
2.4
2.4
2.4
PVD Aluminum, %
2.4
1.8
1.2
2.4
Appearance (liquid &
lustrous
Reduced
Further
dull liquid & loss
cured coating)
luster but
reduced luster
of aluminum
acceptable
than Ex 6 &
flakes during
reflectivity
lighter in
printing due to
color
agglomeration
Stability
Stable for
Stable for
Stable for
dull liquid within
more than 3
more than 3
more than 3
24 hours
months
months
months
[0077] As shown in Table 4, the decreasing the content of PVD aluminium generally decreases the gloss and negatively affects the appearance. It further indicates that substitution of less than 25% with conventional leafing aluminium would yield acceptable reflectivity: the gloss level is higher than 190 GU at 60 degree measurement. While U.S. Pat. No. 6,805,917 teaches the addition of Modoflow as a flow additive to improve flow and wetting, the addition of such additive destroyed the leafing effects of metal flakes and rendered the coating composition unusable.
[0078] The components of Example 9 are listed in Table 5. The viscosity of this composition was measured to be 185-190 cP. The oligomer, two monomers, optical brightener, and initiator were mixed in an amber jar at room temperature with a lab mixer until the solids were completely dissolved. The rest of the components were then added and mixed until uniform.
[0000]
TABLE 5
UV-Curable Top Coating Composition
UV topcoat
Component
EX 9 (wt %)
Acrylate
Ebecryl 3720 TM20 (80% Bisphenol-A-epoxy diacrylate
26.00
oligomer
oligomer diluted in 20% TMPTA monomer)
Acrylate
trimethylol propane triacrylate
45.33
monomer
Tripropylene glycol diacrylate
5.00
Photoinitiator
Benzophenone
15.00
Cure
methyldiethanol amine (MDEA)
7.00
Accelerator
Additive
Optical brightener, (OB)
0.07
Paint additive 57 (Dow Chemical)
1.60
Total
100.00
[0079] The components of a water-based UV-curable colorant and water-based UV-curable top coating composition are described in Table 6. The components were added in sequence, as listed in Table 6, in an amber glass jar using a lab mixer. Each component was added while mixing to avoid precipitation or crashing out the emulsion. This was then stored in an amber jars for storage.
[0000]
TABLE 6
Water-based UV-curable Colorant and Water-based UV-curable
Top Coating Composition
WB UV
Ex 10
Ex 11
topcoat
Component
(wt %)
(wt %)
Acrylate
LUX484 (Alberdingk Boley)
55.21
91.50
polymer
dispersion
Photoinitiator
Liquid mixture of benzophenone
1.21
2.00
and 1-hydroxy-cyclohexyl-
phenyl-ketone
Irgacure 819W
0.91
1.50
Additive
BYK 333 flow additive
1.21
2.00
BYK349 wetting additive
1.21
2.00
Isopropyl alcohol
0.60
1.00
Water-Deionized
15.09
RD6210 red pigment dispersion
19.62
(Spectrachem)
RYL6832 yellow pigment
dispersion (Spectrachem)
4.95
Total
100.00
100.00
Viscosity: #1 Spindle, 60 rpm
12-14 cps
24-26 cps
% Solid
38-40%
40-42%
[0080] On clay treated paper substrate, various combinations of metallic coating, colorants and UV curable top coating and water-based UV curable top coating were applied. As indicated in Table 7, each layer was applied successively and then fully cured before applying the next layer. The gloss of each finish was then measured and reported in Table 7. All samples were coated with a wire-wound rod #4, unless otherwise noted (#2.5 wire-wound rod was used for UV topcoat). The metallic coating and the UV coatings were both cured at 100 mJ/cm 2 ; and the water based composition was first dried at 60-70° C. for 20 seconds and then cured at 100 mJ/cm 2 .
[0000]
TABLE 7
Gloss Measurements on Various Coating Finishes
20 degree
60 degree
Clay Treated Paper Substrate
Gloss (GU)
Gloss (GU)
Appearance
1. UV curable metallic coating (EX 5)
101-130
276-279
Lustrous metallic
finishes
1. UV curable top coating (Ex 9)
80-83
98-98.9
Typical UV topcoat
appearance
1. UV curable metallic coating (EX 5)
Still lustrous metallic
2. UV curable top coating (Ex 9)
117-129
172-175
finishes
1. UV curable metallic coating (EX 5)
11-16
58-65
Metallic red but with
2. Water-based Red Colorant (EX 10)
typical lower gloss of
water based inks partly
due to pigment loading
1. UV curable metallic coating (EX 5)
78-82
103-104
Regained shinny
2. Water-based Red Colorant (EX 10)
metallic red with the
3. UV curable top coating (EX 9)
UV top coat
1. Water-based UV Top coating (EX
22-24
68-71
Slightly higher gloss
11)
than a typical water
based coating.
1. UV curable metallic coating (EX 5)
64-85
160-167
Regained shinny
2. Water-based UV-curable top coating
metallic with Water-
(EX 11)
based UV top coating
[0081] The application of the UV curable top coating or water-based UV curable top coating on cured UV curable metallic coating resulted in a metallic finish. While the application of a water-based colorant decreased the gloss level, application of a UV top coating increased gloss of the entire system.
[0082] To demonstrate plastic substrate coated with a UV curable metallic coating composition, Example 12 was combined in similar fashion to Example 5. Acrylate oligomer, acrylate monomers, photoinitiators, cure accelerator, and additive were combined in a stainless steel container, and mixed with a lab mixer at 40-50° C. until the mixture became uniform. After cooling to room temperature, metal flakes and solvent were added and mixed until uniform.
[0000]
TABLE 8
UV-curable Metallic Composition
Component
Ex 12 (wt %)
Acrylate
Polyester acrylate oligomer
19.93
oligomer
(CN2298 from Sartomer)
Acrylate
Hexanediol diacrylate
22.86
monomer
Trimethylolpropane triacrylate
4.28
Photoinitiator
1-hydroxy-cyclohexyl-phenyl-
4.28
ketone
Eutectic mixture of benzophenone
2.86
and methyl benzophenone
Ethyl (2,4,6-trimethylbenzoyl)
4.29
phenylphosphinate
Cure
Ethyl 4-(dimethylamino) benzoate
1.43
Accelerator
Additive
Hydroquinone monomethyl ether
0.35
Metal Flake #1
Leafing PVD aluminum 20%
6.86
dispersed in ethoxylated trimethyol
propane triacrylate
Metal Flake #2
Leafing PVD aluminum flake, 8%
32.86
dispersed in propoxylated (2)
neopentyl glycol diacrylate
Sub-Total
100.00
Solvent
Isopropyl alcohol
57.00
Total
157.00
% Solid
62-64%
% Aluminum per total solid*
6.34%
Viscosity: #1 spindle, 60 rpm
22-24 cps
*Aluminum wt % was calculated based on the total weight of the composition, excluding solvent
[0083] On corona treated polyethylene terephalate substrate, various combinations of metallic coating, colorants, UV curable top coating, and water-based UV curable top coating were applied. As indicated in Table 9, each layer was applied successively using wire wound rod #4 and then fully cured before applying the next layer. Each sample was applied on to a substrate with a wire wound rod #4, dried at 60-80° C. for 20 seconds, and cured at 400 mJ/cm 2 .
[0084] The gloss of each finish was then measured and reported in Table 9. The following is a low viscosity composition for low viscosity applicator of for low coating thickness.
[0000]
TABLE 9
Plastic Substrate
20 degree
60 degree
Cross-hatch
Corona treated PET
Gloss (GU)
Gloss (GU)
tape adhesion
Comment
1. UV-curable metallic
144-149
235-242
100%
Lustrous
composition (EX 12)
metallic finishes
1. UV-curable metallic
112-118
165-170
95-100%
Good shinny
composition (EX 12)
metallic color
2. Water-based UV curable
top coating (EX 11)
1. UV-curable metallic
139-146
167-171
60%
Good shinny
composition (EX 12)
metallic color
2. UV curable top coating
(EX 9) diluted with 24%
isopropyl alcohol (viscosity:
20-22 cps)
[0085] The measured gloss values in Table 9 exceeded 160 GU, even with the inks and top coats. The cross-hatch tape adhesion test (tested in accordance with ASTM D3359) indicates that Example 12 alone, and Example 11 coated on top of cured Example 12 had good adhesion (100% as having no coating flake off). Due to the high cross-hatch tape adhesion rating, the UV-curable metallic composition may be used alone, even without the top coating for protecting the metal flakes. The solvent UV topcoat diluted with isopropyl alcohol showed degraded adhesion due to high shrinkage crosslinking of low molecular weight oligomer and monomer. The water based UV top coat on the cured UV-curable metallic composition, however, exhibited lower shrinkage, and may be attributed to the higher molecular weight polymer emulsion of the water-based top coat.
[0086] Many modifications and variations of this invention can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. The specific embodiments described herein are offered by way of example only, and the invention is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. | The invention provides an ultraviolet light curable metallic composition, and articles made therewith. The UV-curable metallic compositions provide a high gloss metallic finish, retain the gloss level over storage duration, and maintain press and shelf stability, while maintaining fast cure speeds. The metallic finishes of the instant compositions have gloss above 190 GU measured at 60°. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a dental prosthodontic apparatus and a method of securing and recovering a dental prosthesis. In more detail, the present invention relates to a dental prosthodontic apparatus which is provided with a gap for insertion of a prying instrument with surfaces formed in the gap against which the prying instrument bears for removing the prosthesis, the gap being formed by the lower margin of the prosthesis and the top surface of a riser which is fitted into the abutment on which the prosthesis is received, the fitted riser being sized so as to be slightly coronal to the patient's gum line.
Present dental practice tends toward the replacement of lost teeth with cylindrical or plate metal alloy abutments embedded in the bone of the mandible or maxilla to support the artificial tooth restoration. If extensive replacement of several teeth is needed, several abutments, alone or in conjunction with existing teeth prepared as abutments, are used to anchor the replacement prosthetic teeth.
In the last two decades, significant advances have occurred in both the abutments which are used for such replacements and in the methods used to implant the prosthodontic apparatus in the jaw. In one currently favored practice, titanium alloy abutment cylinders or plates are intimately installed in holes or slots drilled in the underlying bone of the jaw. Several months are allotted to allow the underlying bone to bond to the surfaces of the implant. For this reason, implant bodies are provided with at least one threaded hole on the crestal surface or edge. These holes are temporarily capped with a healing screw to prevent the invagination of soft tissue and/or bone into the internal threads. The soft tissue is sutured over the abutment until an intimate implant-bone bond is completed.
At the next surgical encounter, the soft tissue is resected and the healing screw is replaced with a metal alloy perimucosal extension of selectable height and emergence profile and the soft tissue is sutured around the base of this extension. This extension is usually bolted in place and prevented from rotating by locating pins and holes or internal and external matching hexagonal (or other regular polygonally-shaped) projections. These perimucosal extensions form the support for the artificial abutment(s) used to support the final prosthetic restoration.
The final prosthodontic restoration requires close mechanical mating between the abutment(s) and the internal aspect and underside of the prosthesis which is fitted on and cemented to the abutment. These closely matched parts often consist of telescoped, tapered conical surfaces requiring a tight, non-binding, "passive" fit on the abutment. This requirement demands inordinate precision from the laboratory technician and tests the technical skills of both the dentist and the laboratory technician. Parallel alignment of the axes of each abutment to prevent binding of the tapered fit is not easily achieved.
The methods and apparatus disclosed in Applicant's prior U.S. Pat. No. 5,564,928, in combination with an appropriate dental cement, yield a predictable, controllable technique for securing and, if necessary, retrieving the final restoration by providing a gap, or window, formed in the implant between the cemented prosthesis and abutment. The gap is formed of opposing surfaces on the prosthesis and the abutment with enough space between the surfaces to allow introduction of a prying instrument which can be manipulated to impose a force couple on the opposed surfaces. The dentist uses the prying instrument to apply even, measured force to gradually separate the prosthesis from the cement and gently remove it from the abutment.
Although the prosthodontic abutment described in Applicant's prior patent provides a satisfactory result, there is room for improvement. Specifically, because patients' gums are of varying thicknesses, the distance from the bone in which the abutment is implanted and the gum line varies from patient to patient and even in the same patient receiving multiple restorations. This variability creates a situation in which, even several sizes of the prosthodontic apparatus described in Applicant's Pat. No. 5,564,928 does not provide enough options to the restoring dentist to size the implant so that the gap between the prosthesis and the implant is positioned just coronal to the gum line. Even if several sizes of the prosthodontic apparatus described in that prior patent did provide enough variability, the mere fact that it must be provided in several sizes increases its cost and requires that the restoring dentist, lab or implant/abutment vendor keep a supply of parts of enough different sizes so as to provide the necessary variability.
It is, therefore, an object of the present invention to overcome this disadvantage by providing a dental prosthodontic apparatus which, even though provided in only several different sizes, is capable of being adapted for use in nearly every circumstance likely to be encountered by the restoring dentist or laboratory technician.
It is another object of the present invention to provide a dental prosthodontic apparatus with a gap between abutment and prosthesis the height of which can be changed relative to the patient's bone and soft tissue in which the abutment is sized to accommodate varying gum thicknesses.
It is another object of the present invention to provide a method of forming a gap in an implanted dental prosthodontic apparatus for allowing insertion of a prying instrument for retrieval of the prosthesis.
Yet another object of the present invention is to provide a method of mounting a dental prosthesis to an abutment connected to an implant placed in a jaw.
It is another object of the present invention to provide a dental prosthodontic kit having a plurality of risers of different heights for selection and insertion into a slot formed in an abutment so as to form a gap between the abutment having the riser of selected height therein and the prosthesis.
Other objects, and the advantages of the dental prosthesis of the present invention will be made clear to those skilled in the art by the following description of the presently preferred embodiments thereof.
SUMMARY OF THE INVENTION
The prosthodontic apparatus of the present invention achieves these objects by providing an elongate slot formed as part of an abutment with the longitudinal axis of the slot substantially parallel to the longitudinal axis of the abutment and on the lingual side of the abutment. The abutment is configured with a first portion comprising a substantially frustroconically tapered shaft and a second, central portion the surface of which is substantially flat and orthogonal to the longitudinal axis of the abutment and which forms the platform which the prosthetic restoration will contact. The abutment may be attached to the implant body by a compression screw directed through a shaft in the abutment and screwing into a threaded shaft in the implant body, which is a substantially cylindrical shaft and which is implanted into the bone of the maxilla or mandible. Alternatively, the implant body may be blade shaped.
The slot is configured to receive a riser which fits into and is retained in the slot. The risers are of various lengths and one end of the riser comprises a shelf which is substantially orthogonal to the longitudinal axis of the abutment-implant complex and preferably substantially parallel to the margin of the prosthesis mounted on the abutment when the riser is placed in the slot. The length of the riser is chosen so as to position the end comprising the shelf at a position which is just coronal to the gum line of the patient in which the prosthodontic apparatus is secured.
The present invention further teaches the formation of a groove in the surface of the abutment orthogonal to the longitudinal groove formed in the abutment connecting to the gap formed between the top of the riser and the margin of the prosthesis.
The present invention also teaches the provision of one or more holes for receiving means for gripping said fitted riser. In an alternative embodiment, the fitted riser is provided with an additional threaded shaft accepting a set screw to prevent dislodgement of said riser in a coronal direction. In the preferred embodiment, the gripping means is provided with prongs which fit into the holes and the restoring dentist uses the gripping means to insert and remove the fitted riser into/from the slot.
The present invention also teaches the use of a shield made of a material which is applied in liquid or paste form, subsequently hardens but which is easily removable from the surfaces of the abutment to which it is applied. The shield is used to fill the longitudinal groove in the abutment, the orthogonal groove, and the slot formed in the abutment prior to making an impression on the interior of the mold used to cast the prosthesis so that when the shield is removed and the positive cast of the prosthesis is fitted onto the abutment, the grooves and slot formed in the abutment will be free of excess material. In an alternative, the shield may be applied with the fitted riser in place in the slot so that the shield fills the grooves and the space forming the gap proximate to the shelf of the fitted riser.
A further teaching of the present invention is the method of securing a dental prosthesis on an abutment formed as part of an abutment-implant complex in a jaw comprising the steps of forming a shield in a first, longitudinal groove in an abutment, a second, orthogonal groove, and a slot formed the abutment and making an impression of the shielded abutment. The impression is then used to form a dental prosthesis and the shield is then removed from the slot and the grooves. A fitted riser is inserted into the slot and the prosthesis is applied to the abutment. The prosthesis is pressed onto the abutment while excess dental cement is extruded through the grooves until the top of the riser and the margin of the prosthesis form a gap into which a prying tool can be inserted for subsequent removal of the prosthesis.
The present invention further teaches the utilization of a dental prosthesis kit comprising a dental implant and abutment and a plurality of fitted risers of varying lengths, each riser being insertable into a slot formed in said abutment, and a tool formed to grip said fitted riser for insertion or removal from said slot.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are partially schematic views of a preferred embodiment of the dental prosthodontic apparatus of the present invention from the lingual side as implanted in the jaw of a patient, the gum and bone lines being shown in phantom lines and of different relative dimensions.
FIG. 3 is a side, elevational view of the dental prosthodontic apparatus of FIGS. 1 and 2 having the prosthesis removed therefrom for showing the grooves in the abutment and the fitted riser in the slot of the abutment.
FIG. 4 is an elevational view of the lingual aspect of the dental prosthodontic apparatus of FIG. 3.
FIG. 5 is a perspective, partially exploded view of the dental prosthodontic apparatus of FIG. 3.
FIG. 6 is a perspective view of the dental prosthodontic apparatus of FIG. 3 showing a fitted riser in place in the longitudinal slot formed in the abutment and a phantom line representing the patient's gum line to illustrate the manner in which the shelf formed by the top surface of the fitted riser approximates the gum line.
FIG. 7.1 is a perspective view of the dental prosthodontic apparatus of FIG. 3 showing a shield in place in the grooves and shelf formed in the abutment for casting an impression.
FIG. 7.2 is a perspective view of the dental prosthodontic apparatus of FIG. 3 showing a shield in place in the grooves and slot formed in the abutment for casting an impression.
FIG. 8 is a top plan view of the dental prosthodontic apparatus of FIG. 3.
FIGS. 9, 10 and 11 show top plan views of three alternative embodiments of the dental prosthodontic apparatus of the present invention.
FIGS. 12.1, 13, and 14 are side elevational views of three fitted risers, each of different heights, shown removed from the longitudinal slot of the dental prosthodontic apparatus of FIG. 3.
FIG. 12.2 shows a side elevational view of a fitted riser provided additionally with a threaded shaft to accept a set screw also shown ready for placement.
FIG. 15 is a longitudinal sectional, partially-exploded view (lingual aspect to the right) of a presently preferred embodiment of the dental prosthodontic apparatus of the present invention.
FIG. 16 is an exploded, side elevational view of the dental prosthodontic apparatus of FIG. 15.
FIG. 17 is an exploded, side elevational view of another alternative embodiment of the dental prosthodontic apparatus of the present invention.
FIG. 18 is a top plan view of a preferred embodiment of a kit constructed in accordance with the teachings of the present invention including a plurality of fitted risers and means for engaging the risers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the dental prosthodontic apparatus of the present invention is shown from the lingual aspect implanted in the jaw of a patient in FIGS. 1 and 2. The apparatus, indicated generally at reference numeral 10, is comprised of an elongate abutment 26 to which a prosthesis 12 is mounted and is implanted in the mandible or maxilla of the patient's jaw, the bone being represented by the dotted line B in the figures. FIGS. 1 and 2 further show the apparatus 10 situated between two normal teeth 14 and 16. The abutment 26 is formed with a transverse hole 8 which allows bony invagination when the abutment is implanted into the bone to add strength and stability. Although not shown well in FIGS. 1 and 2 because of the scale, the gap 38 formed between the proximal margin 11 of the prosthesis 12 and the shelf 37 comprised of the distal surface 36 of the fitted riser 30 (best shown in FIG. 5) receives a prying instrument (not shown) for removing the prosthesis 12 from abutment 26 as taught in prior U.S. Pat. No. 5,564,928, hereby incorporated into this disclosure in its entirety by this specific reference.
In the preferred embodiment, the abutment 26 is comprised of a first, preferably (although not necessarily) frustroconical portion 20, a second rounded portion 27 with a substantially flat surface 28, said flat surface 28 proximate to the first portion 20, the abutment 26 provided with a shaft accepting a compression screw 23. In the preferred embodiment, the compression screw 23 is inserted through the abutment 26 contacting and threadably inserted into the implant 1. In an alternative embodiment, the abutment 26 and the implant 1 are constructed as a unified piece. In a proper surgical implantation, the implant 1 is implanted into a hole (not numbered) in the bone of the maxilla or mandible and set deeply enough in the hole that the rounded surface 29 of the second portion 27 of abutment 26 rests on the surface 4 of the bone. As can be seen by comparison of FIGS. 1 and 2, the amount of tissue comprising the gum, the margin of which is represented by the line at 2, varies between the figures, as does the thickness of the gum tissue from patient to patient and even from location to location in the mouth of a single patient. The differences in the thickness of the gum tissue, represented by the dimensions x 1 in FIG. 1 and x 2 in FIG. 2, requires that the shelf 36 comprising one surface of the gap 38 into which a prying instrument is inserted for removing the prosthesis 12 from the implanted abutment 26 be at different heights so as to always be located above the gum line 2. In other words, the dimensions x 1 and x 2 representing the distance from the top surface 4 of the bone to the top surface 2 of the patient's gum also represent the distance along the longitudinal axis of abutment 26 between the shelf 36 and the rounded surface 29 of the abutment 26 which rests on the top surface of the bone 4.
If constructed in accordance with the above-incorporated patent, to obtain a proper fit of the abutment 26 in the patient's gum, the abutment 26 must be provided to the restoring dentist in a variety of sizes and/or relative proportions. To overcome the need for providing the abutment in such a wide variety of sizes and proportions, the abutment 26 of the prosthodontic apparatus of the present invention is provided with an elongate slot 22, best shown in FIGS. 3-6, in the second portion 27 thereof. Slot 40 is shaped to receive and affirmatively retain the fitted riser 30 therein so that, when the riser 30 rests therein, the distal surface 37 (this surface is referred to as a "distal," rather than a top, surface because when the prosthodontic apparatus 10 is implanted in the maxilla, the surface faces downwardly such that referring to a "top" surface is misleading, it being understood from this disclosure by those skilled in the art that the surface 37 is distal from the bone 4 of the patient's jaw) forms the shelf 36 which comprises one surface of the gap 38 into which a prying instrument is inserted for removing the prosthesis 12 from abutment 26.
When the abutment of the prosthodontic apparatus of the present invention is constructed as shown in FIGS. 3-6, risers of different longitudinal dimensions as shown in FIGS. 12-14 are inserted by the restoring dentist into slot 40 to provide the proper spacing along the longitudinal axis of the abutment 26 so that the distal surface 36 of the riser 30 is located proximate the patient's gum line 2. Each of the risers shown in FIGS. 12-14 is provided with a plurality of holes 32 and 34 for receiving means for engaging the riser 30 top facilitate insertion and removal of the riser 30 in/from the longitudinal slot 40 in abutment 26. In the embodiment shown in FIG. 12.2, the fitted riser is additionally provided with a threaded shaft 33 penetrating through the fitted riser and into which may be inserted a set screw 35. In the embodiment shown in FIG. 18, the riser engaging means comprises a fork 52 with prongs 54 spaced so as to engage both of the holes 32 and 34 of riser 30. In the particularly preferred embodiment, the fork 52 is comprised of a resilient material such as plastic so that the prongs 54 and the axes of the holes 32 and 34 are not quite parallel so that the prongs 54 are deflected slightly upon insertion into the holes 32 and 34 so as to help provide a tight friction fit of the engaging means to the riser 30. However, because of the small size of the riser 30 and the tendency of the riser to be wetted by the oral mucosa, it is preferred that the riser engaging means be able to grip the riser 30 for removal from the slot 40.
Those skilled in the art who have the benefit of this disclosure will recognize that the fork 52 is but one form of riser engaging means which may be used to advantage. Other such engaging means may take the form of a clamp on the end of a handle, a fork with a single prong, a handle having a blade or point on the end for engaging a cleat or nipple formed on the lingual aspect of the riser, or a chisel which is simply driven into the abutment between the slot 40 and the riser 30 to pop the riser up out of the slot 40.
FIGS. 15 and 16 show the prosthesis 12 positioned for fitting onto the first portion 20 of the abutment 26. In the embodiment shown, the third portion 23 of abutment 26 is comprised of a compression screw penetrating through the abutment 26 and threadable into the implant body 1 whereby the abutment 26 is secured to the implant body 1. In the alternative embodiment shown in FIG. 17, the abutment 26 and implant 1 are provided as a single, unified piece.
Referring once again to FIGS. 5-7, reference is made to the longitudinal groove 22 formed in the first portion of abutment 26. A second groove 24, perpendicular to groove 22 and substantially orthogonal to the longitudinal axis of abutment 26, is formed in the surface 28 of the second portion 27 of abutment 26 which connects to the longitudinal groove 22 and leads from groove 22 to the gap 38 that is formed between the proximal margin 11 of prosthesis 12 and the shelf 36 comprised of the distal surface 37 of fitted riser 30. The combination of the longitudinal and orthogonal grooves 22 and 24 functions in the same manner as the hydrostatic pressure relief channel described in Applicant's application Ser. No. 08/730,092, which is hereby incorporated into this disclosure in its entirety by this specific reference. Briefly, after an appropriate dental cement is applied to the prosthesis 12 and the prosthesis is then forced down over the first portion 20 of abutment 26, the excess cement is squeezed out from between the prosthesis 12 and abutment 26 through the channel formed by the grooves 22 and 24 into the gap 38. However, a difference between the apparatus described in Applicant's application Ser. No. 08/730,092 and the dental prosthodontic apparatus 10 of the present invention is that the fitted riser 30 of the apparatus 10 of the present invention is inserted into the slot 40 before the prosthesis 12 is pressed down over the first portion 20 of abutment 26.
As noted above, to achieve the proper fit between the surgically implanted abutment 26 and the prosthesis, an impression must be made. FIG. 7.1 shows a shield 50 in place in grooves 22 and 24 and the gap 38 in abutment 26. FIG. 7.2 shows the shield 50 in place in grooves 22 and 24 and the slot 40 in abutment 26. The shield 50 is preferable comprised of a medical grade, moldable material which is cast in place in the implanted abutment 26 so as to fill the grooves 22 and 24 and the gap 38. Alternatively, the shield can also be used to fill the longitudinal slot 40 as shown in FIG. 7.2. In a presently preferred embodiment, this material is a curable silicone material such as SILASTIC® (Dow Coming) silicone polymer which is mixed with a curative while it is squeezed from a tube in a manner known in the art into the grooves 22 and 24 and gap 38. Polymers such as SILASTIC® have the advantage of being easily trimmed so as to remove excess polymer and then, once the impression has been taken, easily removed from the abutment.
FIG. 17 shows the abutment-implant complex 10 as a unified construct rather than two threadably connected pieces.
Referring now to FIG. 18, there is shown a kit which is provided in accordance with the teachings of the present invention. In the preferred embodiment, the kit, indicated generally at reference numeral 60, is comprised of a vacuum-formed plastic tray 62 to which a sterile film 64 can be heat or otherwise bonded as known in the art so that the tray and its contents are sterile around the outer periphery 66 thereof. The tray 62 is formed into a plurality of compartments 68, some 70 of which are sized and shaped so as to provide an exact fit for different size risers 30s, 30m, and 30l, which are contained therein. Because the risers 30s, 30m, and 30l, as a result of their shape and relatively small size, sometimes have a tendency to be a bit elusive, the compartments 70 formed in tray 62 serve the function of restraining the risers 30s, 30m, and 30l from movement when the restoring dentist is using the riser engaging means to handle the riser.
One of the compartments in tray 62 provides an elongate handle 72 having prongs 54 formed on the end thereof of the type described above to provide a fork 52 for engaging the complementary holes 32 and 34 on the risers 30s, 30m, and 30l. Because the tray 62, in its preferred embodiment, is comprised of plastic, when it is desired to utilize the fork 52 for handling the risers, fork 52, which is molded from the same plastic and integrally with the tray 62, is broken off from its compartment in the tray 62 for use in the manner described above.
From the foregoing it is apparent that the present invention is well adapted to attain the properties and features set forth. While several preferred embodiments of the present invention have been shown and described, various modifications and changes may be made to those embodiments without departing from the true spirit and scope of the invention. It will be understood from this disclosure by persons skilled in the art that the apparatus and methods illustrated and described hereinabove are given by way of example only and may be varied widely within the scope of the appended claims. | A dental prosthodontic apparatus including an abutment which is implanted into the jaw of a patient and which is provided with a slot which accepts fitted risers of different lengths. The end of the riser is substantially flat and forms a shelf and the length of the riser is selected so that when the riser is inserted into the slot, the end is approximately level with the gum line of the patient. When a prostheses is mounted to the abutment, the proximal margin of the prosthesis forms a gap between the margin of the prosthesis and the shelf formed by the inserted riser. The gap provides opposed surfaces against which a prying instrument can be worked in the event the prosthesis needs to be removed from the abutment. | 0 |
NOTICE OF RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/341,565, filed Jul. 13, 1999, entitled FIELD PROGRAMMABLE PROCESSOR DEVICES, and naming Alan Marshall, Anthony Stansfield and Jean Vuillemin as joint inventors, which application is hereby incorporated by reference in its entirety, which application is itself a US counterpart to EP Patent Application 97300562.2, filed Jan. 29, 1997, entitled FIELD PROGRAMMABLE PROCESSOR DEVICES, and naming Alan Marshall, Anthony Stansfield and Jean Vuillemin as joint inventors, which application is hereby incorporated by reference in its entirety. This application claims the benefit of both above-cited applications.
BACKGROUND OF THE INVENTION
[0002] This invention relates to field programmable devices.
[0003] In particular, the invention relates to such a device comprising: a plurality of processing devices; a connection matrix interconnecting the processing devices and including a plurality of switches; a plurality of memory cells for storing data for controlling the switches to define the configuration of the interconnections of the connection matrix.
[0004] The problems with which the present invention (or at least preferred embodiments of it) is concerned are to provide more flexible use of memory, to enable higher memory density and higher circuit density.
SUMMARY OF THE INVENTION
[0005] In accordance with a first aspect of the present invention, there is provided means for isolating the effect of the data stored in at least one group of the memory cells and switches on the configuration of the interconnections so that the memory cells in that group are available for storing other data. Accordingly, the memory cells can be selectively used (a) for controlling the interconnections and (b) as user memory. By providing this feature using the configuration memory for the switches, higher memory density can be achieved.
[0006] In one embodiment, the isolating means comprises means for isolating each of the memory cells in the group from the switches. This enables isolation without requiring additional switches to be introduced into the wiring of the connection matrix, which would increase signal propagation delay and so reduce circuit speed.
[0007] This latter feature may be provided in devices which do not require memory cells to be isolated in groups. Therefore, in accordance with a second aspect of the present invention, there is provided a field programmable device, comprising: a plurality of processing devices; a connection matrix interconnecting the processing devices and including a plurality of switches; a plurality of memory cells for storing data for controlling the switches to define the configuration of the interconnections of the connection matrix; and means for isolating each of the memory cells from the switch or switches controllable by that memory cell.
[0008] The isolating means is preferably operable to set each of the switches in the group to a predetermined state upon isolation from the respective memory cell. Accordingly, when isolated, the switches may still provide a predetermined connection in the connection matrix, but they may all be set to “off”.
[0009] The isolating means preferably comprises, for each memory cell, a respective gate having inputs connected to the memory cell and to a control signal, and having an output connected to the or each switch which can be controlled by that memory cell. The use of a gate ensures that the switch is controlled by a well defined logic level at all times, whether it is being controlled by the memory cell or the control signal. Each gate may provided by four transistors, and one of the transistors of each gate may be common to a plurality of the gates, thus enabling an increased circuit density to be achieved.
[0010] In another embodiment, the isolating means comprises means for isolating each of the switches in the group from the remainder of the connection matrix.
[0011] At least some of the interconnections provided by the connection matrix may be in the form of plural-bit busses, with those of the switches for the busses each comprising a plurality of switch elements each for a respective bit of the bus.
[0012] The positions of the memory cells are preferably distributed across the device to substantially the same extent as the switches, and each of the memory cells is disposed adjacent the switch or switches controllable by that memory cell, thus enabling a high circuit density to be achieved.
[0013] This latter feature may be provided, whether or not the memory cells are isolatable. Therefore, in accordance with a third aspect of the present invention, there is provided a field programmable device, comprising: a plurality of processing devices; a connection matrix interconnecting the processing devices and including a plurality of switches; and a plurality of memory cells for storing data for controlling the switches to define the configuration of the interconnections of the connection matrix; wherein the positions of the memory cells are distributed across the device to substantially the same extent as the switches, and each of the memory cells is disposed adjacent the switch or switches controllable by that memory cell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A specific embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0015] [0015]FIG. 1 shows part of a processor array, illustrating six switching sections and the locations of six arithmetic logic units;
[0016] [0016]FIG. 2 is a diagram of part of the arrangement shown in FIG. 1 on a larger scale, illustrating one of the switching sections and one of the locations of the arithmetic logic units;
[0017] [0017]FIG. 3 shows part of the processor array shown in FIG. 1 on a smaller scale, illustrating the locations of the arithmetic logic units and “vertical” busses extending across them;
[0018] [0018]FIG. 4 is similar to FIG. 3, but illustrating “horizontal” busses extending across the locations of the arithmetic logic units;
[0019] [0019]FIG. 5 shows the interconnections between the busses of FIGS. 2, 3 and 4 at the location of one of the arithmetic logic units;
[0020] [0020]FIG. 6A shows in detail the circuitry of one type of programmable switch in the switching sections, for connecting a pair of 4-bit busses which cross each other;
[0021] [0021]FIG. 6B shows in detail the circuitry of another type of programmable switch in the switching sections, for connecting a pair of 4-bit busses which meet each other end to end;
[0022] [0022]FIG. 6C shows in detail the circuitry of another type of programmable switch in the switching sections, for connecting carry-bit busses;
[0023] [0023]FIG. 7 shows the circuitry of a series of NOR gates which may be used in the programmable switches of FIGS. 5 and 6;
[0024] [0024]FIG. 8 shows a modification to the circuitry of FIG. 7;
[0025] [0025]FIG. 9 shows a buffer and register which may be used in each switching section;
[0026] [0026]FIG. 10 is a schematic drawing illustrating how enable signals may be distributed to the programmable switches in the switching sections; and
[0027] [0027]FIG. 11 shows in more detail the circuitry of the arrangement shown in FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] In the following description, the terms “horizontal”, “vertical”, “North”, “South”, “East” and “West” have been used to assist in an understanding of relative directions, but their use is not intended to imply any restriction on the absolute orientation of the embodiment of the invention.
[0029] The processor array which forms the embodiment of the invention is provided in an integrated circuit. At one level, the processor array is formed by a rectangular (and preferably square) array of “tiles” 10 , one of which is shown bounded by a thick line in FIG. 1. Any appropriate number of tiles may be employed, for example in a 16×16, 32×32 or 64×64 array. Each tile 10 is rectangular (and preferably square) and is divided into four circuit areas. It is preferable for these tiles to be logically square (to provide symmetry in connection), although it is of less significance that they be physically square (this may have some advantage in providing symmetry in timing, but this will generally be less likely to be of significance). Two of the circuit areas 12 , which are diagonally opposed in the tile 10 , provide the locations for two arithmetic logic units (“ALUs”). The other two circuit areas, which are diagonally opposed in the tile 10 , provide the locations for a pair of switching sections 14 .
[0030] Referring to FIGS. 1 and 2, each ALU has a first pair of 4-bit inputs a, which are directly connected within the ALU, a second pair of 4-bit inputs b, which are also directly connected within the ALU, and four 4-bit outputs f, which are directly connected within the ALU. Each ALU also has an independent pair of 1-bit carry inputs hci, vci, and a pair of 1-bit carry outputs co, which are directly connected within the ALU. The ALU can perform standard operations on the input signals a, b, hci, vci to produce the output signals f, co, such as add, subtract, AND, NAND, OR, NOR, XOR, NXOR and multiplexing and optionally can register the result of the operation. The instructions to the ALUs may be provided from respective 4 -bit memory cells whose values can be set via the “H-tree” structure described below, or may be provided on the bus system which will be described below.
[0031] At the level shown in FIGS. 1 and 2, each switching section 14 has eight busses extending across it horizontally, and eight busses extending across it vertically, thus forming an 8×8 rectangular array of 64 crossing points, which have been numbered in FIG. 2 with Cartesian co-ordinates. All of the busses have a width of four bits, with the exception of the carry bus vc at X=4 and the carry bus hc at Y=3, which have a width of one bit. At many of the crossing points, a 4-gang programmable switch 16 is provided which can selectively connect the two busses at that crossing point. At some of the crossing points, a 4-gang programmable switch 18 is provided which can selectively connect two busses which meet end to end at that crossing point, without any connection to the bus at right angles thereto. At the crossing point at (4, 3), a programmable switch 20 (for example as shown in FIG. 6C) is provided which can selectively connect the carry busses vc, he which cross at right angles at that point.
[0032] The horizontal busses in the switching section 14 will now be described.
[0033] At Y=0, busses h 2 s are connectable by programmable switches 16 to the vertical busses at X=0, 1, 2, 5, 6. The busses h 2 s have a length of two tiles and are connectable end to end in every other switching section 14 by a programmable switch 18 at (4, 0).
[0034] At Y=1, a bus be extending from an input b of the ALU to the West is connectable by switches 16 to the vertical busses at X=0, 1, 2, 3. Also, a bus fw extending from an output f of the ALU to the East is connectable by switches 16 to the vertical busses at X=5, 6, 7. The ends of the busses be, fw are connectable by a programmable switch 18 at (4, 1).
[0035] At Y=2, a bus hregs is connectable by programmable switches 16 to the vertical busses at X—1, 2.3, 5, 6, 7.
[0036] At Y=3, a bus hco extends from the carry output co of the ALU to the West to a programmable switch 20 at (4, 3), which can connect the bus hco (a) to a carry bus hci extending to the carry input hci of the ALU to the East or (b) to a carry bus vci extending to the carry input vci of the ALU to the South.
[0037] At Y=4, a bus hregn is connectable by programmable switches 16 to the vertical busses at X=0, 1, 2, 3, 5, 6.
[0038] At Y=5, busses h 1 are connectable to the vertical busses at X=0, 1, 2, 3, 5, 6, 7. The busses h 1 have a length of one tile and are connectable end to end in each switching section 14 by a programmable switch 18 at (4, 5).
[0039] At Y=6, a bus fe extending from an output f of the ALU to the West is connectable by switches 16 to the vertical busses at X=0, 1, 2, 3. Also, a bus aw extending from an input a of the ALU to the East is connectable by switches 16 to the vertical busses at X=5, 6, 7. The ends of the busses fe, aw are connectable by a programmable switch 18 at (4, 6).
[0040] At Y=7, busses h 2 n are connectable by programmable switches 16 to the vertical busses at X=1, 2, 3, 6, 7. The busses h 2 n have a length of two tiles and are connectable end to end in every other switching section 14 by a programmable switch 18 at (4, 7), staggered with respect to the programmable switches 18 connecting the busses h 2 s at (4,0).
[0041] The vertical busses in the switching section 14 will now be described.
[0042] At X=0, busses v 2 w are connectable by programmable switches 16 to the horizontal busses at Y=0, 1, 4, 5, 6. The busses v 2 w have a length of two tiles and are connectable end to end in every other switching section 14 by a programmable switch 18 at (0, 3).
[0043] At X=1, a bus fn extending from an output f of the ALU to the South is connectable by programmable switches 16 to the horizontal busses at Y=0, 1, 2. Also, a bus bs extending from an input b of the ALU to the North is connectable by switches 16 to the horizontal busses at Y=4, 5, 6, 7. The ends of the busses fn, bs are connectable by a programmable switch 18 at (1, 3).
[0044] At X=2, busses v 1 are connectable to the horizontal busses at Y=0, 1, 2, 4, 5, 6, 7. The busses v 1 have a length of one tile and are connectable end to end in each switching section 14 by a programmable switch 18 at (2, 3).
[0045] At X=3, a bus vregw is connectable by programmable switches 16 to the horizontal busses at Y=1, 2, 4, 5, 6, 7.
[0046] At X=4, a bus vco extends from the carry output co of the ALU to the North to the programmable switch 20 at (4, 3), which can connect the bus vco (a) to the carry bus hci extending to the carry input hci of the ALU to the East or (b) to the carry bus vci extending to the carry input vci of the ALU to the South.
[0047] At X=5, a bus vrege is connectable by programmable switches 16 to the horizontal busses at Y=0, 1, 2, 4, 5, 6.
[0048] At X=6, a bus an extending from an input a of the ALU to the South is connectable by switches 16 to the horizontal busses at Y=0, 1, 2. Also, a bus fs extending from an output f of the ALU to the North is connectable by programmable switches 16 to the horizontal busses at Y=4, 5, 6, 7. The ends of the busses an, fs are connectable by a programmable switch 18 at (6, 3).
[0049] At X=7, busses v 2 e are connectable by programmable switches 16 to the horizontal busses at Y=1, 2, 5, 6, 7. The busses v 2 e have a length of two tiles and are connectable end to end in every other switching section 14 by a programmable switch 18 at (7, 3) staggered with respect to the programmable switches 18 connecting the busses v 2 w at (0. 3).
[0050] As shown in FIG. 2, the busses bs, vco, fs are connected to input b, output co and output f, respectively, of the ALU to the North of the switching section 14 . Also, the busses fe, hco, be are connected to the output f, output co and input b of the ALU, respectively, to the West of the switching section 14 . Furthermore, the busses aw, hci, fw are connected to the input a, input ci and output f, respectively, of the ALU to the East of the switching section 14 . Moreover, the busses m, vci, an are connected to the output f, input ci and input a, respectively, of the ALU to the south of the switching section 14 .
[0051] In addition to these connections, the busses vregw, vrege are connected via respective programmable switches 18 to 4-bit connection points vtsw, vtse, respectively, (shown by crosses in FIG. 2) in the area 12 of the ALU to the North of the switching section 14 . Also, the busses hregs, hregn are connected via respective programmable switches 18 to 4-bit connection points htse, htne, respectively, in the area 12 of the ALU to the West of the switching section 14 . Furthermore, the busses hregs, hregn are connected via respective programmable switches 18 to 4-bit connection points htsw, htnw, respectively, in the area 12 of the ALU to the East of the switching section 14 . Moreover, the busses vregw, vrege are connected via respective programmable switches 18 to 4-bit connection points vtnw, vtne, respectively, in the area 12 of the ALU to the south of the switching section 14 . These connection points vtnw, vtne, htne, htse, vtse, vtsw, htsw, htnw will be described below in further detail with reference to FIGS. 3 to 5 .
[0052] Also, as shown in FIG. 2, the busses hregn, vrege, hregs, vregw have respective 4-bit connection points 22 (shown by small squares in FIG. 2) which will be described below in further detail with reference to FIG. 9.
[0053] [0053]FIG. 3 shows one level of interconnections between the locations of the arithmetic logic units, which are illustrated by squares with rounded corners. A group of four 4-bit busses v 8 , v 4 w , v 4 e , v 16 extend vertically across each column of ALU locations 12 . The leftmost bus v 8 in each group is in segments, each having a length generally of eight tiles. The leftmost but one bus v 4 w in each group is in segments, each having a length generally of four tiles. The rightmost but one bus v 4 e in each group is in segments, again each having a length generally of four tiles, but offset by two tiles from the leftmost but one bus v 4 w . The rightmost bus v 16 in each group is in segments, each having a length generally of sixteen tiles. At the top edge of the array, which is at the top of FIG. 4, and at the bottom edge the lengths of the segments may be slightly greater than or shorter than specified above.
[0054] Referring to FIGS. 3 and 5, where each group of four busses v 8 , v 4 w , v 4 e , v 16 crosses each ALU location 12 , four 4-bit tap connections are made at the connection points htnw, htsw, htse, htne. The ends of the bus segments take priority in being so connected over a connection to a bus segment which crosses the ALU location.
[0055] Similarly, as shown in FIGS. 4 and 5, a group of four 4-bit busses h 8 , h 4 n , h 4 s , h 16 extend horizontally across each row of ALU locations 12 . The uppermost bus h 8 in each group is in segments, each having a length generally of eight tiles. The uppermost but one bus h 4 n in each group is in segments, each having a length generally of four tiles. The lowermost but one bus h 4 s in each group is in segments, again each having a length generally of four tiles, but offset by two tiles from the uppermost but one bus h 4 n . The lowermost bus h 16 in each group is in segments, each having a length generally of sixteen tiles. At the left hand edge of the array, which is at the left of FIG. 4, and at the right hand edge the lengths of the segments may be slightly greater than or shorter than specified above. Where each group of busses h 8 , h 4 n , h 4 s , h 16 crosses each ALU location 12 , a further four 4-bit tap connections are made at the connection points vtnw, vtsw, vtse, vtne. The ends of the bus segments take priority in being so connected over a connection to a bus segment which crosses the ALU location.
[0056] As shown in FIG. 5, the connection points htnw, htsw, htne, htse are connected via programmable switches to the busses hregn, hregs of the switching sections to the West and the East of the ALU location. Also, the connection points vtnw, vtne, vtsw, vtse are connected via programmable switches to the busses vregw, vrege of the switching sections to the North and the South of the ALU location.
[0057] The programmable connections 16 between pairs of 4-bit busses which cross at right angles will now be described with reference to FIG. 6A. The conductors of the horizontal busses are denoted as x 0 , x 1 , x 2 , x 3 , and the conductors of me vertical busses are denoted as y 0 , y 1 , y 2 , y 3 . Between each pair of conductors of the same bit significance, a respective transistor 160 , 161 , 162 , 163 is provided. The gates of the transistors 160 , 161 , 162 , 163 are connected in common to the output of a NOR gate 16 g , which receives as its two inputs an inverted ENABLE signal from a single bit memory cell, which may be shared by a group of the switches, and the inverted content of a single bit memory cell 24 . Accordingly, only when the ENABLE signal is high and the content of the memory cell 24 is high, the conductors x 0 , x 1 , x 2 , x 3 are connected by the transistors 160 , 161 , 162 , 163 , respectively, to the conductors y 0 , y 1 , y 2 , y 3 , respectively.
[0058] The programmable connections 18 between pairs of 4-bit busses which meet each other end to end in line will now be described with reference to FIG. 6B. The conductors of one bus are denoted as x 10 , x 11 , x 12 , x 13 , and the conductors of the other bus are denoted as x 20 , x 21 , x 22 , x 23 . Between each pair of conductors of the same bit significance, a respective transistor 180 , 181 , 182 , 183 is provided. The gates of the transistors 180 , 181 , 182 , 183 are connected in common to the output of a NOR gate 18 g , which receives as its two inputs an inverted ENABLE signal from a single bit memory cell, which may be shared by a group of the switches, and the inverted content of a single bit memory cell 24 . Accordingly, only when the ENABLE signal is high and the content of the memory cell 24 is high, the conductors x 10 , x 11 , x 12 , x 13 are connected by the transistors 180 , 181 , 182 , 183 , respectively, to the conductors x 20 , x 21 , x 22 , x 23 , respectively.
[0059] The programmable connections 20 between the carry conductors hco, vco, hci, vci will now be described with reference to FIG. 6C. The horizontal carry output conductor hco is connected to the horizontal carry input conductor hci and the vertical carry input conductor vci via transistors 20 hh , 20 hv , respectively. Furthermore, the vertical carry output conductor vco is connected to the vertical carry input conductor vci and the horizontal carry input conductor hci via transistors 20 vv , 20 vh , respectively. The gates of the transistors 20 hh , 20 vv are connected in common to the output of an inverter 20 i , and the gates of the transistors 20 hv , 20 vh and the input to the inverter 20 i are connected to the output of a NOR gate 20 g . The NOR gate 20 g receives as its two inputs an inverted ENABLE signal from a single bit memory cell. which may be shared by a group of the switches, and the inverted content of a single bit memory cell 24 . Accordingly, when the ENABLE signal is high, the conductors hco, vco are connected to the conductors hci, vci, respectively, or to the conductors vci, hci, respectively, in dependence upon the content of the memory cell 24 .
[0060] It will be noted that each of the switchable connections 16 , 18 , 20 described with reference to FIGS. 6A to 6 C includes a NOR gate 16 g , 18 g , 20 g . As shown in FIG. 7, a NOR gate 16 g is typically formed by four transistors 16 g 1 , 16 g 2 , 16 g 3 , 16 g 4 , two 16 g 1 , 16 g 3 of which are responsive to the inverted ENABLE signal, and two 16 g 2 , 16 g 4 of which are responsive to the inverted content of the memory cell 24 . In the embodiment of the invention, it is desirable that a group of the switchable collections 16 , 18 , 20 may be disabled in common, without any need for only part of such a group to be disabled. Such a group might consist of all of the switchable connections in one switching section 14 , all of the switchable connections in the two switching sections 14 in a particular tile, or all of the switchable connections in a larger area of the array. In this case, the transistor 16 g 1 may be made common to all of the switchable connections 16 , 18 , 20 in the group, as shown in FIG. 8. This enables a 25 % less one saving in the number of transistors required for the gates, but does require a further conductor linking the gate, as shown in FIG. 8.
[0061] The man skilled in the art will appreciate that the structures depicted in FIGS. 7 and 8 can be modified for optimisation. For example, the arrangement of FIGS. 7 and 8 would not fully exploit memory cells 24 designed to return both a stored value and a complement of that stored value. Use of the complement obtained from such cells 24 could be used to obviate any need for both the ENABLE and inverted ENABLE signals to be carried to all of the switchable connections in a group, as is the case in FIG. 8.
[0062] As mentioned above with reference to FIGS. 1 and 2, at each switching section 14 , the busses hregn, hregs, vregw, vrege are connected by respective 4-bit connections 22 to a register or buffer circuit, and this circuit will now be described in more detail with reference to FIG. 9. The four connections 22 are each connected to respective inputs of a multiplexer 26 . The multiplexer 26 th selects one of the inputs as an output, which is supplied to a register or buffer 28 . The output of the register or buffer 28 is supplied to four tri-state buffers 30 s , 30 w , 30 n , 30 e , which are connected back to the connections 22 to the busses hregs, vregw, hregn, vrege, respectively. In the case where a buffer 28 is used, the 4-bit signal on a selected one of the busses hregs, vregw, hregn, vrege is amplified and supplied to another selected one of the busses hregs, vregw, hregn, vrege. In the case where a register 28 is used, the 4 -bit signal on a selected one of the busses hregs, vregw, hregn, vrege is amplified and supplied to any selected one of the busses hregs, vregw, hregn, vrege after the next active clock edge.
[0063] It will be appreciated that the arrangement described above provides great flexibility in the routing of signals around and across the array. With appropriate setting of the switches 16 , 18 , 20 using the memory cells 24 and with appropriate setting of the multiplexers 26 and registers or buffers 28 , signals can been sent over large distances, primarily using the busses v 16 , h 16 , v 8 , h 8 , v 4 e , v 4 w , h 4 n , h 4 s from the edge of the array to a particular ALU, between ALUs, and from a particular ALU to the edge of the array. These busses can be joined together in line, or at right angles, by the switching sections 14 , with amplification by the registers or buffers 28 in order to reduce propagation delays, and with pipeline stages introduced by the registers 28 . Also, these busses can be tapped part way along their lengths, so that the siting of the ALUs to perform a particular processing operation is not completely dictated by the lengths of the busses, and so that signals can be distributed to more than one ALU. Furthermore, the shorter length busses described with reference to FIGS. 1 and 2 can be used to route signals between the switching sections 14 and the ALUs, and to send signals primarily over shorter distances, for example from one ALU to an adjacent ALU in the same row or column, or diagonally adjacent, even though the busses extend horizontally or vertically. Again, the registers or buffers 28 can be used to amplify the signals or introduce programmable delays into them.
[0064] In the arrangement described above, the memory cells 24 are distributed across the array to the same extent as the switching sections 14 and the ALU locations 12 . Each memory cell 24 is disposed adjacent the switch or switches, multiplexer, register or buffer which it controls. This enables a high circuit density be achieved.
[0065] A description will now be made of the manner in which data is written to or read from the memory cells 24 , the way in which the ENABLE signals for the programmable switches 16 , 18 , 20 are written to their memory cells, the way in which instructions, and possibly constants, are distributed to the ALUs, and the way in which other control signals, such as a clock signal, are transmitted across the array. For all of these functions, an “H-tree” structure (which is known per se) may be employed, as shown in FIG. 10. Referring to FIGS. 10 and 11, in order to distribute an ENABLE signal to any of 64 locations in the example shown, the ENABLE signal 30 a and a 6-bit address 32 a for it are supplied to a decoder 34 a . The decoder 34 a determines which of the four branches from it leads to the address and supplies an ENABLE signal 30 b to a further decoder 34 b in that branch, together with a 4-bit address 32 b to the decoders 34 b in all four branches. The decoder 34 b receiving the ENABLE signal 30 b determines which of the four branches from it leads to the required address and supplies an ENABLE signal 30 c to a further decoder 34 c in that branch, together with a 4-bit address 32 c to the decoders 34 c in all four branches. The decoder 34 c receiving the ENABLE signal 30 c then supplies the ENABLE signal 34 d to the required address where it can be stored in a single bit memory cell. An advantage of the H-tree structure is that the lengths of the signal paths to all of the destinations are approximately equal, which is particularly advantageous in the case of the clock signal.
[0066] A great advantage of the arrangement described above is that groups of the memory cells 24 in for example one switching section 14 , or in the two switching sections in one tile, or in the switching sections in a sub-array of the tiles may be disabled en bloc by the inverted ENABLE signals so that the contents of those memory cells do not affect the associated switches. It is then possible for those memory cells 24 to be used as “user” memory by an application, rather than being used for configuring the wiring of the array.
[0067] The embodiment of the invention has been described merely by way of example, and many modifications and developments may be made in keeping with the present invention. For example, the embodiment employs ALUs as the processing units, but other processing units may additionally or alternatively be used, for example look-up tables, programmable logic arrays and/or self-contained CPUs which are able to fetch their own instructions.
[0068] Furthermore, the embodiment has been described as if the whole array is covered by ALUs and switching sections. However, other types of section may be included in the array. For example, a sub-array might be composed of a 4×4 arrangement of tiles of ALUs and switching sections as described above, and the array might be composed of such sub-arrays and memory in a 4 x 4 array, or such sub-arrays and RISC CPUs in a 4×4 array.
[0069] In the embodiment described above, each ALU location is square, and each switching section is square and of the same size as the ALU locations, but it should be noted that the controllable switches 18 in the register busses vregw, vrege, hregn, hregs encroach into the square outline of the ALU locations. The ALU locations need not be of the same size as the switching sections, and in particular may be smaller, thus permitting one or more busses to pass horizontally or vertically directly from one switching section 14 to a diagonally adjacent switching section 14 , for example running between the busses h 2 s , h 2 n or between the busses v 2 e , v 2 w.
[0070] In the embodiment described above, each ALU has two independent carry inputs vci, hci and a connected pair of carry outputs co. If required, the ALUs may be arranged to deal with two types of carry: a fast carry between adjacent ALUs which may be of particular use for multi-bit adding operations; and a slow carry which can be routed more flexibly and may be of particular use for digital serial arithmetic. The fast carry might be arranged in a similar manner to that described above with reference to the drawings, whereas the slow carry might employ programmable switches in the switching sections 14 between the carry conductor and particular bits of the 4-bit busses.
[0071] In the embodiment described above, particular bit widths, sizes of switching section and sizes of array have been mentioned, but it should be noted that all of these values may be changed as appropriate. Also, the programmable switches 16 , 18 , 20 have been described as being disposed at particular locations in each switching section 14 , but other locations may be used as required and desired.
[0072] In the embodiment described above, the array is two-dimensional, but the principles of the invention are also applicable to three-dimensional arrays, for example by providing a stack of the arrays described above, with the switching sections in adjacent layers staggered with respect to each other. The stack might include just two layers, but preferably at least three layers, and the number of layers is preferably a power of two. In the embodiment described above, the memory cells 24 can be isolated by the gates 16 g , 18 g , 20 g from the switches which they control so that the memory cells can be used for other purposes, that is put in the “user plane”. The ENABLE signal memory cells, however, cannot be transferred to the user plane. In an alternative embodiment, the switches in a particular switching section 14 may be disconnectable from the remainder of the array by further switches in the busses at the boundary of that switching section 14 , with the further switches being controlled by a further memory cell which cannot be transferred to the user plane.
[0073] Many other modifications and developments may also be made. | A field programmable device comprising an array of processing devices, a connection matrix interconnecting the processing device and including switches, and memory cells for storing data for controlling the switches to define the configuration of the interconnections of the connection matrix. In order to provide flexible use of memory and to enable higher memory densities, gates are provided which can be used to isolate the effect of the data stored in groups of the memory cells and switches on the configuration of the interconnections so that the memory cells in that group are available for storing other data. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a valve performance control apparatus for an internal combustion engine, which controls the valve performance of intake valves and exhaust valves provided in an internal combustion engine, such as the opening and closing timings of the valves, in accordance with the running condition of the engine.
2. Description of the Related Art
Each intake valve or exhaust valve in an internal combustion engine is reciprocatively driven by the rotation of the camshaft to periodically open and close the associated intake port or exhaust port, which is communicates with the associated combustion chamber of the engine. As the intake valve opens, air-fuel mixture is drawn into the combustion chamber through the intake port. The gas produced by combustion in the combustion chamber is discharged from the chamber through the exhaust port as the exhaust valve opens.
In a typical internal combustion engine, the times at which the individual ports are opened and closed by the associated valves are determined by the profiles of the cams of the associated camshafts.
To improve the output power or the performance of an internal combustion engine, some schemes have recently been proposed to alter the timing of opening and closing the valves, i.e., the valve timing, in accordance with the running condition of the engine. Japanese Unexamined Patent Publication No. 4-228843 discloses an example of such an intake/exhaust control apparatus for an internal combustion engine.
The control apparatus will be discussed below. As shown in the schematic structural diagram of FIG. 15, the control apparatus includes an intake camshaft 101, an exhaust camshaft 102, variable valve timing (VVT) mechanisms 103, 104, which are respectively provided on the ends of the camshafts 101, 102, a hydraulic pressure circuit 105 for supplying oil into the VVTs 103, 104, and an electronic control unit (ECU) 108.
Pulleys 109, 110 of the VVTs 103, 104 are respectively coupled to the crankshaft (not shown) of an engine (not shown) via a timing belt (not shown). The pulleys 109, 110 transmit the torque of the crankshaft to the camshafts 101, 102, respectively.
Each camshaft 101, 102 has a plurality of cams 111, 112, respectively, which cause the reciprocative motion of the corresponding intake valve or the exhaust valve in accordance with the rotation of the camshafts 101, 102. The intake valve or the exhaust valve opens and closes the corresponding intake port (not shown) or the exhaust port (not shown).
Each VVT 103, 104 has a pair of pressure chambers (not shown) formed therein where oil is supplied via the hydraulic pressure circuit 105. The pressure of the oil supplied to the pressure chambers causes the associated VVT 103, 104 to rotate relative to the pulley 109, 110 of the associated camshaft 101, 102. As a result, the relative rotational phase of the camshaft 101, 102 with respect to the crankshaft changes and alters the valve timing of the associated intake valve or the exhaust valve.
The hydraulic pressure circuit 105 has an oil pan 113 for retaining oil, an oil pump 114, which is driven by the crankshaft (not shown) of the engine, and an oil filter 115. The oil pump 114 supplies the oil in the oil pan 113 to the individual pressure chambers of the VVT 103, 104 via respective passages 106a, 106b and 106c, 106d. Electromagnetic valves 107a, 107b, 107c, 107d are arranged in the passages 106a, 106b, 106c, 106d, respectively, to open and close the associated passages 106a-106d and adjust the amount of oil to be supplied to the individual pressure chambers.
Various sensors 116, including an engine speed sensor, output detection signals to the ECU 108 in accordance with the running condition of the engine (not shown). The ECU 108 controls the individual electromagnetic valves 107a-107d based on the detection signals. This enables the control apparatus to optimize the valve timing of each valve in accordance with the running condition of the engine.
The control apparatus supplies oil to the VVTs 103, 104 from the common oil pump 114. Therefore, the amount of oil supplied to each VVT 103, 104 when oil is supplied to both VVTs 103, 104 to drive the VVTs 103, 104, simultaneously, is reduced as compared with the case where only one of the VVTs 103, 104 is driven. Accordingly, the amount of oil supplied to the VVTs 103, 104 may sometimes be insufficient. This may slow the operational speed of the VVTs 103, 104 and thus may slow the speed of altering the valve timing of the individual valves. Therefore, it may be difficult to quickly change the valve timing of each valve to the optimal timing in response to a change in the running condition of the engine. This may slow the valve timing control response.
As a solution to this shortcoming, the discharge performance of the oil pump 114 (the discharge amount per unit time) may be increased to prevent the valve timing control response from becoming slow. Since the oil pump 114 is normally driven by the crankshaft, this structure increases the driving resistance of the crankshaft, reducing the net output of the engine. The structure further results in a larger oil pump 114. This leads to a larger engine.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide a valve performance control apparatus for an internal combustion engine, which has a pair of mechanisms for changing the valve performance of intake valves and exhaust valves in an internal combustion engine, and supplies fluid to both mechanisms from a common fluid source to drive the mechanisms to thereby control the valve performance of the individual valves, and which has an improved control response characteristic without increasing the driving resistance of the crankshaft or enlarging the fluid source.
To achieve the above objective, the present invention provides an apparatus for controlling valve performance of an internal combustion engine. The engine has a combustion chamber communicating with an air intake passage and an air exhaust passage. The intake passage has an air intake valve that is selectively opened and closed to control airflow passing in the intake passage to the combustion chamber. The exhaust passage has an air exhaust valve that is selectively opened and closed to control exhaust gas flow passing in the exhaust passage from the combustion chamber. Each of the valves is actuated by a camshaft based on valve performance affecting opening and closing timing and a lift amount of the valve. The apparatus includes a first changing means for changing the valve performance of the intake valve. The first changing means is actuated by fluid pressure. A second changing means changes the valve performance of the exhaust valve. The second changing means is actuated by the fluid pressure. A fluid source is connected with the first changing means and the second changing means to supply fluid to the first changing means and the second changing means. An adjusting means adjusts the amount of the fluid supplied from the fluid source to the first changing means and the second changing means. A detecting means detects the running condition of the engine. A control means controls the adjusting means to change each valve performance so as to coincide the engine torque with the desired engine torque. The control means includes selecting means for selecting one of the valves based on the detected running condition of the engine. The selected valve is capable of coinciding the engine torque with the desired torque faster than the other one of valves to allow a larger amount of the fluid supplied to one of the changing means that is associated with the selected valve than the other one of the changing means.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principals of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings.
FIG. 1 is a schematic structural diagram illustrating a first embodiment of an engine system according to a first embodiment of the present invention;
FIG. 2 is a cross-sectional view showing the intake-side VVT;
FIG. 3 is a cross-sectional view showing the intake-side oil control valve (OCV);
FIG. 4 is a cross-sectional view showing the exhaust-side OCV;
FIG. 5 is a flowchart illustrating individual processes in the VVT control routine of the first embodiment;
FIG. 6 is a graph showing the relation between the deviation and the compensation deviation;
FIG. 7 is a graph showing the relation between the final deviation and the duty ratio;
FIG. 8 is a timing chart showing the time-dependent behaviors of parameters such as the amount of oil supplied to each VVT and the displacement angle;
FIG. 9 is an explanatory diagram for explaining the operation of the first embodiment;
FIG. 10 is a graph showing a time-dependent change in the output torque;
FIG. 11 is a flowchart illustrating individual processes in the VVT control routine of a second embodiment according to the present invention;
FIG. 12 is an explanatory diagram for explaining the operation of the second embodiment;
FIG. 13 is a graph showing the relation between the final deviation and the duty ratio in a further embodiment according to the present invention;
FIG. 14 is a timing chart showing the time-dependent behaviors of parameters such as the amount of oil to be supplied to each VVT and the displacement angle of the second embodiment; and
FIG. 15 is a schematic system structural diagram of an intake/exhaust control apparatus for an internal combustion engine in the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
A first embodiment of a valve performance control apparatus according to the present invention and applied to a gasoline engine for a vehicle will now be described referring to FIGS. 1 through 10.
FIG. 1 shows the schematic structure of a gasoline engine 10. As shown in FIG. 1, the engine 10 includes an intake camshaft 11, an exhaust camshaft 12, intake-side and exhaust-side variable valve timing mechanisms (hereinafter referred to as intake VVT and exhaust VVT) 13, 14, which are provided on the camshafts 11, 12, respectively, a crankshaft 15, and an electronic control unit (ECU) 16 for controlling the VVTs 13, 14.
The engine 10 has a cylinder block 17, an oil pan 18 fixed to the bottom of the cylinder block 17, and a cylinder head 19 fixed to the top of the block 17. The oil pan 18 retains lubrication oil which is supplied to the individual sections of the engine 10. The cylinder block 17 has a plurality of cylinders 20 each having a combustion chamber 20a. While there are a total of four cylinders 20 in this embodiment, only one of them is illustrated in FIG. 1.
The cylinder block 17 supports the crankshaft 15 in a rotational manner. A piston 21 located in each cylinder 20 is coupled via a connecting rod 22 to the crankshaft 15, which rotates as the pistons 21 move up and down.
The cylinder head 19 has a plurality of intake valves 23 and exhaust valves 24 in association with the individual cylinders 20, and the intake ports 25a and exhaust ports 26a communicate with the associated combustion chambers 20a. Each intake port 25a is connected to an intake passage 25 and each exhaust port 26a is connected to an exhaust passage 26. The intake valves 23 and the exhaust valves 24 selectively open and close the associated intake and exhaust ports 25a, 26a.
The cylinder head 19 rotatably supports the intake camshaft 11 and the exhaust camshaft 12, which is arranged parallel to the shaft 11. The intake camshaft 11 and exhaust camshaft 12 have a plurality of pairs of cams 27, 28, respectively, which are provided at predetermined intervals in the axial direction. As the camshafts 11, 12 rotate, the cams 27, 28 cause the intake valves 23 and the exhaust valves 24 to reciprocate.
The VVTs 13, 14 provided on the ends of the camshafts 11, 12, respectively, function to change the timing of opening and closing the associated valves 23, 24, that is, the valve timing.
FIG. 2 shows the cross section of the intake camshaft 11 and the exhaust VVT 13. The structure of the exhaust camshaft 12 and the exhaust VVT 14 is the same as that of the intake camshaft 11 and the intake VVT 13. Thus, the exhaust camshaft 12 and the exhaust VVT will not be described below to avoid redundant description.
The intake VVT 13 has a pulley 30, an inner cap 31, a cover 32, and a ring gear 33. The cylinder head 19 and a bearing cap 34 rotatably support a journal 11a of the intake camshaft 11. The pulley 30 has a disk portion 301, a plurality of external teeth 35 formed on the outer periphery of the disk portion 301, and a boss 36 formed in the center of the disk portion 301. The pulley 30 is rotatably coupled to the boss 36 at the distal end portion (the left side as viewed in FIG. 2) of the intake camshaft 11.
A timing belt 37 is wound around the outer teeth 35 of the pulley 30 and connected to a pulley 38 of the exhaust VVT 14 and a crank pulley 39 of the crankshaft 15, as shown in FIG. 1. The torque of the crankshaft 15 is transmitted to the pulleys 38, 30 via the crank pulley 39 and the timing belt 37, and further transmitted to both camshafts 11, 12 via the pulleys 38, 30.
The cover 32 is cup shaped. The cover 32 covers the disk portion 301 of the pulley 30 and the distal end portion of the intake camshaft 11. A hole 323 is formed in the center of the cover 32. This hole 323 is closed by a cap 324. The cover 32 is fixed to the disk portion 301 by a plurality of pins 321 and bolts 322, so that the pulley 30 and the cover 32 rotate together.
A plurality of inner teeth 40 are formed on the inner periphery of the cover 32. The inner teeth 40 are helical teeth and are inclined by a predetermined angle with respect to the axis L of the intake camshaft 11.
The inner cap 31 is attached to the distal end of the intake camshaft 11 by a hollow bolt 41. The inner cap 31 is secured to the intake camshaft 11 by a pin 411, so that the inner cap 31 and the intake camshaft 11 rotate integrally.
Formed on the outer periphery of the inner cap 31 are a plurality of external helical teeth 42 which are similar to the inner teeth 40 of the cover 32.
The ring gear 33 is placed in an annular space 43 defined between the pulley 30, the cover 32, and the inner cap 31. Inner helical teeth 45 and external helical teeth 46, similar to the inner teeth 40, are formed on the inner periphery and the outer periphery of the ring gear 33. The inner teeth 45 engage with the external teeth 42 of the inner cap 31, and the external teeth 46 engage with the inner teeth 40 of the cover 32. The torque transmitted to the pulley 30 is therefore transmitted to the intake camshaft 11 via the ring gear 33 and the inner cap 31.
The ring gear 33 partitions the space 43 into two pressure chambers 50 and 52. The distal end portion (left side as viewed in FIG. 2) of the space 43 with respect to the ring gear 33 forms the first pressure chamber 50, while the proximal end portion (right side as viewed in FIG. 2) of the space 43 with respect to the ring gear 33 forms the second pressure chamber 52. The inner cap 31, the cover 32, the cap 324, and the hollow bolt 41 form a space 325, which communicates with the first pressure chamber 50.
A first pressure passage 51 and a second pressure passage 53 for supplying oil to the first pressure chamber 50 and the second pressure chamber 52 will now be described.
A pair of oil holes 54, 55 are formed in the bearing cap 34. The oil holes 54, 55 are connected to an intake-side oil control valve (hereinafter referred to as intake OCV) 60 by associated oil passages 56, 57.
An oil groove 63 is formed extending around the entire journal 11a of the camshaft 11. The oil groove 63 is connected to the oil hole 54. The oil hole 54 is located at the proximal end side (right side as viewed in FIG. 2) of the oil hole 55. An oil passage 64, which communicates with the oil groove 63, is defined in the intake camshaft 11. A center hole 65 extends through the bolt 41 axially. The center hole 65 connects the oil passage 64 to the space 325. The oil passage 56, the oil hole 54, the oil groove 63, the oil passage 64, the center hole 65, and the space 325 constitute the first pressure passage 51.
Another oil groove 66 is formed extending around the entire journal 11a of the camshaft 11 at a position closer to the distal end of the camshaft 11 than the oil groove 63. The oil groove 66 is connected to the oil hole 55. The oil hole 55 is located at the distal end side (left side as viewed in FIG. 2) of the oil hole 54. Another oil passage 67, which communicates with the oil groove 66, is formed in the intake camshaft 11. The oil passage 67 is connected to the second pressure chamber 52 via a space 311, which is defined between the inner cap 31, the distal end portion of the intake camshaft 11, and the boss 36 of the pulley 30. The oil passage 57, the oil hole 55, the oil groove 66, the oil passage 67, and the space 311 constitute the second pressure passage 53.
A structure for supplying oil to the first pressure passage 51 and the second pressure passage 53 will now be described.
As shown in FIG. 1, an oil pump 62 is connected to the crankshaft 15 so that it is driven by the rotation of the crankshaft 15. The oil pump 62 draws in oil that is retained in the oil pan 18 and forces the oil to the intake OCV 60 via a discharge passage 59. An oil filter 61 is disposed in the discharge passage 59 to sieve out foreign matter contained in the oil.
The intake OCV 60 serves to adjust the amount of oil (the level of the hydraulic pressure) supplied to the pressure chambers 50, 52 via the first and second pressure passages 51, 53. The intake OCV 60 has a substantially cylindrical casing 70 and a spool 75, which is reciprocally retained in the casing 70. The intake OCV 60 further includes an electromagnetic solenoid 79, which reciprocates the spool 75 and which is located at the rear side (right side as viewed in FIG. 2) of the casing 70, and a spring 78, which is located at the front side (left side as viewed in FIG. 2) of the casing 70 to normally urge the spool 75 rearward.
The casing 70 has a tank port 71, a pair of reservoir ports 72a, 72b, and a pair of discharge ports 73, 74. The tank port 71 is connected to the oil pump 62 via the discharge passage 59. The reservoir ports 72a, 72b are connected to the oil pan 18 via drain passages 58a, 58b, respectively. The discharge ports 73, 74 are supplied to the oil holes 54, 55, which are formed in the bearing cap 34, by way of the associated oil passages 56, 57.
The spool 75 has four lands 76 one of which blocks the flow of oil between each of the pairs of ports 71, 73; 71, 74; 73, 72a; and 74, 72b. The spool 75 has three passages 77a, 77b, and 77c extending between the adjacent lands 76. The passages 77a to 77c connect the ports 71, 73; 71, 74; 73, 72a; and 74, 72b to permit the flow of oil.
The spool 75 moves to a position where the forward urging force of the electromagnetic solenoid 79 is balanced with the rearward urging force of the spring 78. The urging force generated by the solenoid 79 is determined by the duty ratio of an exciting signal input to the solenoid 79. As the spool 75 moves to a predetermined position in accordance with the duty ratio, the connected state of the ports 71-74 is altered. The level of the hydraulic pressure communicated to the first and second pressure chambers 50, 52 is adjusted by altering the connected states of the individual ports 71-74 in this manner.
As shown in FIG. 1, the exhaust VVT 14 provided on the exhaust camshaft 12 is connected to the oil pump 62 by the discharge passage 59 via the oil filter 61 in the same manner as the intake VVT 13. An exhaust OCV 80, which communicates with the discharge passage 59, has the same structure as the intake OCV 60, and adjusts the amount of oil (the levels of the hydraulic pressure) supplied from the oil pump 62 to the first and second pressure chambers (not shown) of the exhaust VVT 14.
As shown in FIG. 1, the engine 10 is provided with sensors 81, 82, 83, 84 to detect the running condition of the engine 10.
Cam angle sensors 81, 82 are respectively provided with rotors 81a, 82a, which rotate integrally with the intake and exhaust camshafts 11, 12, and electromagnetic pickups 81b, 82b, which are opposed to the rotors 81a, 82a. The rotors 81a, 82a are disk-shaped magnetic bodies each having multiple teeth projecting from their outer peripheries. The electromagnetic pickups 81b, 82b output cam angle pulse signals SGIN2, SGEX2 each time the teeth of the rotors 81a, 82a pass by the pickups 81b, 82b as the camshafts 11, 12 rotate.
The crank angle sensor 83 has a rotor 83a, which rotates together with the crankshaft 15, and an electromagnetic pickup 83b facing the rotor 83a. The rotor 83a is formed of a disk-shaped magnetic body having multiple teeth formed at the outer periphery. The electromagnetic pickup 83b outputs a crank angle pulse signal SG1 every time a tooth of the rotor 83a passes by the pickup 83b as the crankshaft 15 rotates.
The intake pressure sensor 84 arranged in the intake passage 25 detects the pressure in the passage 25 by comparing the pressure to a vacuum state. The pressure in the intake passage is hereafter referred to as the manifold pressure PM.
The ECU 16 controls the OCVs 60 and 80 based on detection signals from the sensors 81-84. The ECU 16 includes a central processing unit (CPU) 85, a read only memory (ROM) 86, a random access memory (RAM) 87, a backup RAM 88, an input interface circuit 89, and an output interface circuit 90. A bus 91 connects the interface circuits 89 and 90 to each other.
Predetermined control programs and initial data are stored in the ROM 86. For example, a program for controlling the valve timing is stored in the ROM 86. The CPU 85 executes various processes in accordance with the control programs and initial data stored in the ROM 86. The RAM 87 temporarily stores the results of the processing performed by the CPU 85. The backup RAM 88 holds various data in the RAM 87 even after the supply of power to the ECU 16 is stopped.
The cam angle sensors 81, 82, the crank angle sensor 83, and the intake pressure sensor 84 are electrically connected to the input interface circuit 89. The OCVs 60, 80 are electrically connected to the output interface circuit 90. The ECU 16 computes the speed NE of the engine 10, displacement angles VT1, VT2 of the respective camshafts 11, 12 and other parameters based on the detection signals input to the input interface circuit 89 from the sensors 81-84. The ECU 16 controls the OCVs 60, 80 based on the computed values.
For instance, the ECU 16 measures the pulse interval of the crank angle signal SG1 output from the crank angle sensor 83 to compute the number of rotations of the crankshaft 15 per unit time, or the engine speed NE of the engine 10. Based on the cam angle signals SGIN2, SGEX2 and the crank angle signal SG1, the ECU 16 computes the relative rotational phases of the intake and exhaust camshafts 11, 12 with respect to the crankshaft 15, i.e., the displacement angles VT1, VT2. The displacement angles VT1, VT2 correspond to the altered rotational angle of the intake and exhaust camshafts 11, 12, which are altered by the VVTs 13, 14 in order to adjust the valve timing of the intake and exhaust valves 23, 24, respectively.
The ECU 16 controls the level of the hydraulic pressure supplied to the first pressure chamber 50 and the second pressure chamber 52 of the intake VVT 13 by changing the duty ratio DVT1 of the exciting signal, which is sent to the electromagnetic solenoid 79, within the range of 0% to 100%. The ECU 16 alters the valve timing of the intake valve 23 by controlling the hydraulic pressure in the pressure chambers 50, 52.
For example, the ECU 16 excites the electromagnetic solenoid 79 to move the spool 75 forward against the urging force of the spring 78 by holding the duty ratio DVT1 at a value greater than 50%. This moves the spool 75 to a timing advancing position, as shown in FIG. 3.
When the spool 75 reaches the advancing position, the tank port 71 and the discharge port 73 are connected by the passage 77b. This supplies the oil discharged from the oil pump 62 to the first pressure chamber 50 via the discharge passage 59 and the first pressure passage 51. Accordingly, the hydraulic pressure in the first pressure chamber 50 increases.
Furthermore, when the spool 75 reaches the advancing position, the discharge port 74 and the reservoir port 72b are connected by the passage 77c. This allows the oil in the second pressure chamber 52 to return to the oil pan 18 via the second pressure passage 53 and the drain passage 58b. This decreases the hydraulic pressure in the second pressure chamber 52.
Consequently, the hydraulic pressure applied to the ring gear 33 through the first pressure chamber 50 becomes greater than the hydraulic pressure applied to the gear 33 through the second pressure chamber 52. This moves the ring gear 33 toward the proximal end (right side as viewed in FIG. 2) of the intake camshaft 11 as the gear 33 rotates. As a result, torque is applied to the cap 31 thus rotating the inner cap 31 with respect to the pulley 30. The inner cap 31 and the intake camshaft 11 therefore rotate with respect to the pulley 30. The relative rotation changes the rotational phase of the intake camshaft 11 with respect to the pulley 30 and advances the valve timing of the intake valve 23.
When advancing the valve timing of the intake valve 23 in this manner, an increase in the duty ratio DVT1 results in a decrease in the portion of the discharge port 73 closed by the associated land 76. This increases the area of the opening of the port 73. As a result, the amount of oil supplied to the first pressure chamber 50 of the intake VVT 13 increases. This increases the speed of advancing the valve timing.
The ECU 16 moves the spool 75 rearward using the urging force of the spring 78 by exciting the electromagnetic solenoid 79 with the duty ratio DVT1 maintained at a value smaller than 50%. This causes the spool 75 to move to a timing delaying position, as shown in FIG. 2.
When the spool 75 reaches the delaying position, the tank port 71 and the discharge port 74 are connected by the passage 77b. Consequently, the oil discharged from the oil pump 62 is supplied to the second pressure chamber 52 via the discharge passage 59 and the second pressure passage 53. This increases the hydraulic pressure in the second pressure chamber 52.
Furthermore, when the spool 75 reaches the delaying position, the discharge port 73 and the reservoir port 72a are connected by the passage 77a. This allows the oil in the first pressure chamber 50 to return to the oil pan 18 via the first pressure passage 51 and the drain passage 58a. This decreases the hydraulic pressure in the first pressure chamber 50.
Consequently, the hydraulic pressure applied to the ring gear 33 through the second pressure chamber 52 becomes greater than the hydraulic pressure applied to the gear 33 through the first pressure chamber 50. This moves the ring gear 33 toward the distal end (the left side as viewed in FIG. 2) of the intake camshaft 11 as the gear 33 rotates. As a result, torque is applied to the inner cap 31 thus rotating the cap 31 with respect to the pulley 30. The inner cap 31 and the intake camshaft 11 therefore rotate with respect to the pulley 30. The relative rotation changes the rotational phase of the intake camshaft 11 with respect to the pulley 30 and delays the valve timing of the intake valve 23.
When delaying the valve timing of the intake valve 23 in this manner, a decrease in the duty ratio DVT1 results in a decrease in the portion of the discharge port 74 that is closed by the associated land 76. This increases the area of the opening of the port 74. As a result, the amount of oil supplied to the second pressure chamber 52 of the intake VVT 13 increases. This increases the speed of delaying the valve timing.
The ECU 16 moves the spool 75 to a middle position between the advancing position and the delaying position by exciting the electromagnetic solenoid 79 with the duty ratio DVT1 maintained at 50%. (This ratio will hereafter be referred to as sustaining duty ratio DVTH.) As a result, the spool 75 moves to a sustaining position, as shown in FIG. 4.
When the spool 75 reaches the sustaining position, the discharge ports 73, 74 are closed by the associated lands 76. Therefore, oil is neither supplied to nor discharged from the pressure chambers 50, 52. The ring gear 33 is thus held by the hydraulic pressures of the pressure chambers 50, 52. This maintains the current valve timing of the intake valve 23.
As described above, the intake VVT 13 is capable of continuously varying the valve timing of the intake valve 23 with the desirable speed and is also capable of maintaining a desirable timing.
In the same manner, the exhaust VVT 14 is capable of continuously varying the valve timing of the exhaust valve 24 with the desirable speed and also capable of maintaining the desirable timing by changing the duty ratio DVT2 of the electromagnetic solenoid (not shown) employed in the exhaust OCV 80.
Control procedures for controlling the valve timing according to this embodiment will now be discussed with reference to the flowchart in FIG. 5. FIG. 5 illustrates the individual processes in a valve timing control routine (hereafter referred to as the VVT control routine). The ECU 16 executes the routine in a cyclic manner with a predetermined time interval between each cycle.
In step 100, the ECU 16 reads the crank angle signal SG1, the cam angle signals SGIN2, SGEX2, and the manifold pressure PM that are detected by the crank angle sensor 83, the cam angle sensors 81, 82, and the intake pressure sensor 84, respectively.
In step 101, the ECU 16 computes the engine speed NE based on the crank angle signal SG1, and computes the displacement angles VT1, VT2 of the associated camshafts 11, 12 based on the signal SG1 and the cam angle signals SGIN2, SGEX2.
In step 102, the ECU 16 computes target displacement angles VTT1, VTT2 of the associated camshafts 11, 12 in accordance with the engine speed NE and the manifold pressure PM. The ECU 16 also refers to function data stored in the ROM 86. In this embodiment, the function data is set so as to maximize the output torque of the engine 10 when the displacement angles VT1, VT2 become equal to the target displacement angles VTT1, VTT2, respectively, in correspondence with the running condition of the engine 10.
In step 103, the ECU 16 subtracts the displacement angles VT1, VT2 from the target displacement angles VTT1, VTT2, respectively, to compute the deviation ΔVT1 between the displacement angles VTT1, VT1 and the deviation ΔVT2 between the displacement angles VTT2, VT2.
In step 104, the ECU 16 computes compensation deviations ΔVTK1, ΔVTK2 that correspond to the deviations ΔVT1, ΔVT2, respectively. The ECU 16 also refers to function data stored in the ROM 86. This function data differs from the aforementioned function data.
FIG. 6 shows a graph representing the function data. The solid line indicates the relation between the deviation ΔVT1 and the compensation deviation ΔVTK1 for the intake camshaft 11, and the single dotted line indicates the relation between the deviation ΔVT2 and the compensation deviation ΔVTK2 for the exhaust camshaft 12.
It is apparent from the graph that as the deviations ΔVT1, ΔVT2 increases, the compensation deviations ΔVTK1, ΔVTK2 increase. The increase rate of the compensation deviation ΔVTK1 with respect to the deviation ΔVT1, or the inclination of the solid line, is greater than the increase rate of the compensation deviation ΔVTK2 with respect to the deviation ΔVT2, or the inclination of single-dotted line. Accordingly, the compensation deviation ΔVTK1 corresponding to the deviation ΔVT1 is set larger than the compensation deviation ΔVTK2 corresponding to the deviation ΔVT2 even if the deviations ΔVT1, ΔVT2 are equal to each other. In this embodiment, as apparent from the above, the deviations ΔVT1, ΔVT2 are set so that the compensation deviation ΔVTK1 of the intake camshaft 11 becomes larger while the compensation deviation ΔVTK2 of the exhaust camshaft 12 becomes smaller when carrying out step 104.
The valve timings of the intake valve 23 and the exhaust valve 24 influence the characteristics of the engine 10. It is generally known that the valve timing of the intake valve 23 greatly contributes to the enhancement of the output torque of the engine 10 and to the improvement of the fuel consumption. The valve timing of the exhaust valve 24 significantly contributes to suppressing undesirable engine emissions.
With regard to the function data shown in FIG. 6, the inclinations of the solid line and the single dotted-line are determined based on the contribution ratio of the valve timings with respect to a change in the output torque of the engine 10, that is, the change in the output torque, when the individual valve timings are varied by a predetermined level. Since the valve timing of the intake valve 23 contributes to increasing the output torque more than the valve timing of the exhaust valve 24, the inclination of the solid line is set greater than the inclination of the single dotted line in FIG. 6.
In step 105, the ECU 16 determines whether the absolute value |ΔVTK1| of the compensation deviation ΔVTK1 is equal to or greater than the absolute value |ΔVTK2| of the compensation deviation ΔVTK2. When the condition in step 105 is satisfied (|ΔVTK1|≧|ΔVTK2|), the ECU 16 proceeds to step 106.
In step 106, the ECU 16 sets the final deviation ΔVTFIN1 to a value equal to the compensation deviation ΔVTK1 and computes the final deviation ΔVTFIN2 from the following equation (1).
ΔVTFIN2=|ΔVTK2/ΔVTK1|ΔVTK2 (1)
Since the value |ΔVTK2/ΔVTK1| in the equation (1) is equal to or smaller than "1", the value of the computed final deviation ΔVTFIN2 is equal to or smaller than the compensation deviation ΔVTK2. The small value of the computed final deviation ΔVTFIN2 restricts the amount of oil supplied to the exhaust VVT 14.
When the condition in step 105 is not satisfied (|ΔVTK1|<|ΔVTK2|), the ECU 16 proceeds to step 109.
In step 109, the ECU 16 sets the final deviation ΔVTFIN2 as a value equal to the compensation deviation ΔVTK2 and computes the final deviation ΔVTFIN1 from the following equation (2).
ΔVTFIN1=|ΔVTK1/ΔVTK2|ΔVTK1 (2)
Since the value |ΔVTK1/ΔVTK2| in the equation (2) is smaller than "1", the final deviation ΔVTFIN1 is smaller than the compensation deviation ΔVTK1. The small value of the computed final deviation ΔVTFIN1 restricts the amount of oil supplied to the intake VVT 13.
After computing the final deviations ΔVTFIN1, ΔVTFIN2 in either one of the steps 106, 109, the ECU 16 proceeds to step 107.
In step 107, the ECU 16 computes the duty ratios DVT1, DVT2 corresponding to the final deviations ΔVTFIN1, ΔVTFIN2. The ECU 16 also refers to function data stored in the ROM 86. FIG. 7 shows a graph representing the function data. As apparent from this graph, the duty ratios DVT1, DVT2 increase as the final deviations ΔVTFIN1, ΔVTFIN2 increase.
In step 108, the ECU 16 sends exciting signals VS1, VS2 corresponding to the duty ratios DVT1, DVT2 to the OCVs 60, 80, respectively. As a result, the VVTs 13, 14 are actuated to advance or delay the valve timings of the valves 23 and 24 or to sustain the current valve timings. After executing step 108, the ECU 16 temporarily terminates the routine.
The operation of this embodiment when advancing the valve timing will now be described. It is assumed that the displacement angles VT1, VT2 are increased to the target displacement angles VTT1, VTT2 (VTT1=VTT2=4α) from the same predetermined value of 2α (α>0).
FIG. 8 is a timing chart showing time-dependent changes in the target displacement angles VTT1, VTT2, the displacement angles VT1, VT2, the oil amount Q1 supplied to the intake VVT 13, and the oil amount Q2 supplied to the exhaust VVT 14. The ECU 16 executes the individual processes in the VVT control routine every predetermined control cycle after starting the engine 10. Timings t1, t2, t3, t4 in the diagram show representative control timings.
As shown in FIG. 10, when the target displacement angles VTT1, VTT2 are set at 4α at the timing t1, the ECU 16 computes the deviations ΔVT1, ΔVT2 as a predetermined value 2α (=4α-2α).
The ECU 16 then computes the compensation deviations ΔVTK1, ΔVTK2 corresponding to the deviations ΔVT1, ΔVT2, respectively. In this case, the ECU 16 computes the compensation deviation ΔVTK1 corresponding to the deviation ΔVT1 (=2α) as 3α. The ECU 16 also computes the compensation deviation ΔVTK2 corresponding to the deviation ΔVT2 (=2α) as α, as shown in FIG. 6.
Since the absolute value |ΔVTK1| of the compensation deviation ΔVTK1 is equal to or greater than the absolute value |ΔVTK2| of the compensation deviation ΔVTK2 (i.e., |ΔVTK1=3α≧|ΔVTK2|=.alpha.), the ECU 16 sets the final deviation ΔVTFIN1 to a value of 3α, which is equal to the compensation deviation ΔVTK1. The ECU 16 also sets the final deviation ΔVTFIN2 to α/3 in accordance with the equation (1). Afterwards, the ECU 16 computes the duty ratios DVT1, DVT2 according to the final deviations ΔVTFIN1 (=3α), ΔVTFIN2 (=α/3), and sends the exciting signals VS1, VS2 corresponding to the duty ratios DVT1, DVT2 to the OCVs 60, 80, respectively.
In this embodiment, the final deviation ΔVTFIN1 is set greater than the final deviation ΔVTFIN2 (ΔVTFIN1=3α and ΔVTFIN2=α/3) even when the deviations ΔVT1, ΔVT2 are equal to each other (ΔVT1=ΔVT2=2α). The duty ratio DVT1 of the exciting signal VS1 output to the intake OCV 60 therefore becomes greater than the duty ratio DVT2 of the exciting signal VS2 output to the exhaust OCV 80. As shown in FIGS. 8(b) and 8(e), the oil amount Q1 supplied to the intake VVT 13 becomes greater than the oil amount Q2 supplied to the exhaust VVT 14 at the timing t1.
Consequently, as shown in FIGS. 8(c) and 8(f), the displacement angle VT1 increases at an altering rate that is greater than that of the displacement angle VT2 so that the alteration of the valve timing of the intake valve 23 is given priority over the alteration of the valve timing of the exhaust valve 24. Between timings t1 and t2, the oil amount Q1 supplied to the intake VVT 13 is greater than the oil amount Q2 supplied to the exhaust VVT 14. This advances the valve timing of the intake valve 23.
Between timings t1 and t2, an increase in the displacement angles VT1, VT2 decreases the difference between the compensation deviations ΔVTK1, ΔVTK2. This enables the compensation deviations ΔVTK1, ΔVTK2 to eventually coincide with each other. More specifically, when the displacement angles VT1, VT2 respectively become 3.5α and 2.5α (VT1=3.5α and VT2=2.5α) at the timing t2, the ECU 16 computes the deviations ΔVT1, ΔVT2 as 0.5α, 1.5α (ΔVT1=0.5α, ΔVT2=1.5α), respectively. The ECU 16 then computes the compensation deviations ΔVTK1, ΔVTK2 corresponding to the deviations ΔVT1, ΔVT2 as 0.75α.
Consequently, the ECU 16 sends the exciting signals VS1, VS2 corresponding with the duty ratios DVT1, DVT2 to the OCVs 60, 80, respectively. This equalizes the oil amounts Q1, Q2 supplied to the VVTs 13, 14, respectively, and advances the valve timings at an equal altering rate.
In the period starting from the timing t2, the compensation deviations ΔVTK1, ΔVTK2 become equal to each other and the same amount of oil is supplied to the VVTs 13, 14. As the deviations ΔVT1, ΔVT2 decrease, the duty ratios DVT1, DVT2 decrease, as shown in FIG. 7. This gradually decreases the oil amounts Q1, Q2 supplied to the VVTs 13, 14.
At the timing t3, the displacement angle VT1 of the intake camshaft 11 reaches the target displacement angle VTT1 (4α) and the deviation ΔVT1 and the compensation deviation ΔVTK1 both become "0". Therefore, the ECU 16 sets the final deviation ΔVTFIN1 as "0". Since the value of the duty ratio DVT1 is set as the value of the sustaining duty ratio DVTH, the oil amount Q1 supplied to the intake VVT 13 becomes "0".
During the period between the timings t3 and t4, oil is supplied only to the exhaust VVT 14. Thus, only the valve timing of the exhaust valve 24 is varied. At the timing t4, the displacement angle VT2 of the exhaust camshaft 12 reaches the target displacement angle VTT2 (=4α). As a result, the duty ratios DVT1, DVT2 are set to the sustaining duty ratio DVTH after the timing t4. This maintains the current valve timings.
The solid line in FIG. 9 is a characteristic curve indicating the relationship between the displacement angles VT1, VT2 in the above-described example. Points A, C, D and B on this curve correspond to the states of the displacement angles VT1, VT2 at the timings t1 to t4. The displacement angles VT1, VT2 vary along the characteristic curve proceeding in the order of points A, C, D, B.
The dotted lines in FIG. 9 indicate equal torque lines. When displacement angles VT1, VT2 change along the equal torque lines, the change in the output torque of the engine 10 is small. When the displacement angles VT1, VT2 change in a manner exceeding the equal torque line, the output torque of the engine 10 changes greatly.
The double-dotted line in FIG. 9 is a characteristic curve indicating the relationship between the displacement angles VT1, VT2 in a comparative example. The comparative example differs from the preferred embodiment in that the deviations ΔVT1, ΔVT2 are processed equally.
As apparent from the solid line in FIG. 9, priority is given to altering the displacement angle VT1 of the intake camshaft 11 between points A and C (between the timings t1 and t2). Therefore, the characteristic curve (the solid line) in this embodiment is inclined from the characteristic curve (the double-dotted line) of the comparative example, in which the altering rates of the displacement angles VT1, VT2 are equal to each other. Furthermore, between points A and C, the characteristic curve of the preferred embodiment extends substantially perpendicularly with respect to the equal torque lines.
FIG. 10 shows a graph indicating time-dependent changes in the output torque of the preferred embodiment and the comparative example. The solid line shows time-dependent changes in the output torque of the preferred embodiment while the double-dotted line shows time-dependent changes in the output torque of the comparative example.
As apparent from the FIG. 10, the output torques of both the preferred embodiment and the comparative example increase from the initial torque TO at timing t1 to the target torque TTRG at timing t4.
In the comparative example, the output torque increases in a linear manner as time elapses. In comparison, the output torque increases at a greater altering rate between timings t1 to t2 in the preferred embodiment. This is because the characteristic curve (the solid line) showing the relation between the displacement angles VT1, VT2 traverses the equal torque lines substantially perpendicularly, as shown in FIG. 9, when the characteristic curve changes from the state indicated by point A to the state indicated by point C (between the timings t1 and t2).
In the preferred embodiment, the output torque reaches the target torque TTRG earlier than in the comparative example. For example, the output torque requires time Δt2 from the timing t1 to reach a predetermined value T1 in the comparative example. In comparison, the output torque requires a shorter time Δt1 to reach the predetermined value T1.
The foregoing describes the case where the deviations ΔVT1 and ΔVT2 become equal to each other. A description will now be given of the case in which the deviation ΔVT2 of the exhaust camshaft 12 is greater than the deviation ΔVT1 of the intake camshaft 11 at the timing t1 while the condition in step 105 is not satisfied (e.g., when ΔVT1=0.5α and ΔVT2=2α). In this case, since the final deviation ΔVTFIN1 of the intake camshaft 11 is computed from the equation (2) as a smaller value, the alteration of the valve timing of the exhaust valve 24 is given priority over the alteration of the valve timing of the intake valve 23.
The reason for giving priority to the alteration of the valve timing of the exhaust valve 24 when the condition in step 105 is not fulfilled will now be described. As mentioned above, the valve timing of the intake valve 23 contributes more to improving the output torque of the engine 10 than the valve timing of the exhaust valve 24. When the absolute value |ΔVTFIN1| of the final deviation ΔVTFIN1 is small, the duty ratio DVT1 is computed as a small value, as shown in FIG. 7, so that the speed of changing the valve timing of the intake valve 23 becomes slower. In this case, if priority is given to the alteration of the valve timing of the intake valve 23, the rate of increase of the output torque is decreased.
In this embodiment, the absolute values |ΔVTFIN1|, |ΔVTFIN2| of the final deviations ΔVTFIN1, ΔVTFIN2 are compared with each other to determine whether the altering speed of the valve timing of the intake valve 23 is slow enough. If it is determined that this speed is slow enough, priority is given to the alteration of the valve timing of the exhaust valve 24 over the alteration of the valve timing of the intake valve 23. This prevents the rate of increase of the output torque from becoming slower.
Although the foregoing description has been given of the case where the displacement angles VT1, VT2 are both increased (the valve timings are advanced), the valve timing of one of the valves 23, 24, which increases the rate of increase in the output torque of the engine 10, is given priority even when the displacement angles VT1, VT2 are both decreased (the valve timings are delayed) or in the case where one of the displacement angles VT1, VT2 increases while the other displacement angle decreases.
As apparent from above, in this embodiment, the absolute values |ΔVTK1|, |ΔVTK2| of the compensation deviations ΔVTK1, ΔVTK2 are compared with each other to accurately select the valve timing of either the valve 23 or the valve 24, whichever contributes more to increasing the output torque. Accordingly, the amount of oil supplied to the other (unselected) VVT 13, 14 used to vary the valve timing is restricted.
This permits a sufficient amount of oil to be supplied from the oil pump 62 to the VVT 13 or VVT 14 that varies the selected valve timing. This enables the valve timing to be altered at a faster speed. It is thus possible to increase the output torque of the engine 10 to the target torque at an earlier time. This improves the responsiveness of the valve timing control.
Furthermore, the preferred embodiment does not require the enlargement of the oil pump 62 unlike a structure designed to increase the discharge performance of the oil pump 62 in order to acquire the same responsiveness. A substantial decrease in the output torque of the engine 10, which would be caused by driving an oil pump 62 with a larger discharge performance, is also avoided in this embodiment.
Additionally, the preferred embodiment improves the output torque of the engine 10 merely by changing the control of the OCVs 60, 80. Unlike a structure which requires a separate oil pump to actuate the VVTs 13, 14, the preferred embodiment therefore avoids an increase in the cost of the control apparatus.
Second Embodiment
A second embodiment according to the present invention will now be described with reference to FIGS. 11, 12 and 14. In this embodiment, several processes in the VVT control routine differ from the first embodiment. The camshafts 11, 12, the VVTs 13, 14, and the OCVs 60, 80 have the same structures as those of the first embodiment.
FIG. 11 shows a flowchart illustrating the VVT control routine. To avoid redundant description, same numerals are given to those steps that are the same as the corresponding steps in the VVT control routine of the first embodiment, which is shown in FIG. 5.
In this routine, the ECU 16 proceeds to step 200 after executing the steps 100 to 102.
In step 200, the ECU 16 subtracts the displacement angles VT1, VT2 from the target displacement angles VTT1, VTT2 to compute the final deviations ΔVTFIN1, ΔVTFIN2, respectively.
In step 201, the ECU 16 determines whether the absolute value |ΔVTFIN1| of the final deviation ΔVTFIN1 of the intake camshaft 11 is greater than a first determination value ΔJVT1. If this condition is fulfilled (|ΔVTFIN1|>ΔJVT1), the ECU 16 proceeds to step 202.
In step 202, the ECU 16 computes the duty ratio DVT1 in accordance with the final deviation ΔVTFIN1 and sets the value of the duty ratio DVT2 as the value of the sustaining duty ratio DVTH (50%). When computing the duty ratio DVT1, the ECU 16 refers to the function data shown in FIG. 7.
When the condition in step 201 is not fulfilled (|ΔVTFIN1|≦ΔJVT1), the ECU 16 proceeds to step 203.
In step 203, the ECU 16 determines whether the absolute value |ΔVTFIN2| of the final deviation ΔVTFIN2 is greater than a second determination value ΔJVT2. If this condition is satisfied (|ΔVTFIN2|>ΔJVT2), the ECU 16 proceeds to step 204.
In step 204, the ECU 16 sets the value of the duty ratio DVT1 as the value of the sustaining duty ratio DVTH (50%) and computes the duty ratio DVT2 in accordance with the final deviation ΔVTFIN2. When computing the duty ratio DVT2, the ECU 16 refers to the function data shown in FIG. 7.
If the condition in step 203 is not fulfilled (|ΔVTFIN2|≦ΔJVT2), the ECU 16 proceeds to step 205.
In step 205, the ECU 16 computes the duty ratios DVT1, DVT2 in accordance with the final deviations ΔVTFIN1, ΔVTFIN2. During the computation, the ECU 16 refers to the function data shown in FIG. 7.
After executing steps 202, 204, and 205, the ECU 16 proceeds to step 108 and then temporarily terminates the routine after execution of step 108.
In this routine, the first determination value ΔJVT1 is a value for determining whether or not priority should be given to the alteration of the valve timing of the intake valve 23 when varying the valve timings of the intake valve 23 and the exhaust valve 24.
On the other hand, the second determination value ΔJVT2 is a value for determining whether or not priority should be given to the alteration of the valve timing of the exhaust valve 24 when changing the valve timings. The ECU 16 compares the determination values ΔJVT1, ΔJVT2 with the absolute values |ΔVTFIN1|, |ΔVTFIN2| of the final deviations ΔVTFIN1, ΔVTFIN2, respectively, to determine which valve timing should be given priority when changing the valve timings.
FIG. 12 shows a graph for explaining which valve timing should be given priority when changing the valve timings of the intake valve 23 and the exhaust valve 24.
In FIG. 12, priority is given to the valve timing of the intake valve 23 when the absolute value |ΔVTFIN1| of the final deviation ΔVTFIN1 is included in range R1, which includes values greater than the first determination value ΔJVT1. Priority is not given to the valve timing of the exhaust valve 24 in range R1.
Priority is given to the valve timing of the exhaust valve 24 when the absolute value |ΔVTFIN2| of the final deviation ΔVTFIN2 is included in range R2, which includes values greater than the second determination value ΔJVT2. Priority is not given to the valve timing of the intake valve 23 in range R2.
The valve timings are altered based on the duty ratios DVT1, DVT2, which are computed in accordance with the final deviations ΔVTFIN1, ΔVTFIN2, respectively, in range R3, which excludes ranges R1, R2.
In this embodiment, the first determination value ΔJVT1 is set smaller than the second determination value ΔJVT2 (JVT1<JVT2). Accordingly, range R1, in which priority is given to the valve timing of the intake valve 23, is set over a wider range than the other ranges R2, R3, as shown in FIG. 12.
When the absolute values |ΔVTFIN1|, |ΔVTFIN2| of the final deviations ΔVTFIN1, ΔVTFIN2 are equal to each other at point A in FIG. 12 (|ΔVTFIN1|=|VTFIN2|=a), only the valve timing of the intake valve 23 is altered.
As mentioned above, the valve timing of the intake valve 23 contributes more to improving the output torque of the engine 10 than the valve timing of the exhaust valve 24. Thus, in this embodiment, the output torque of the engine 10 is enhanced by setting the first determination value JVT1 smaller than the second determination value JVT2 by giving priority to the alteration of the valve timing of the intake valve 23 over the alteration of the valve timing of the exhaust valve 24.
The operation of this embodiment will now be described when the displacement angles VT1, VT2 of both camshafts 11, 12 sustained at the same predetermined value α are increased to the target displacement angles VTT1, VTT2, which are equal to each other (VTT1=VTT2=β). In this case, the absolute values |VTFIN1|, |ΔVTFIN2| of the final deviations ΔVTFIN1, ΔVTFIN2 vary in the order of the states indicated by points A, B, C, D, and E.
FIG. 14 is a timing chart showing time-dependent changes of the target displacement angles VTT1, VTT2, the displacement angles VT1, VT2, the oil amount Q1 supplied to the intake VVT 13, and the oil amount Q2 supplied to the exhaust VVT 14.
As shown in the FIG. 14, the target displacement angles VTT1, VTT2 are changed to the predetermined value β at timing t1. At this time (at the state shown by the point A in FIG. 12), the absolute value |ΔVTFIN1| of the final deviation ΔVTFIN1 is greater than the determination value ΔJVT1. Thus, the ECU 16 computes the duty ratio DVT1 according to the final deviation ΔVTFIN1 and sets the duty ratio DVT2 to the sustaining duty ratio DVTH.
The ECU 16 then controls the OCVs 60, 80 based on the exciting signals VS1, VS2 corresponding to the duty ratios DVT1, DVT2, respectively. Thus, although oil is not supplied to the exhaust VVT 14, oil amount Q1 is supplied to the intake VVT 13, as shown in FIGS. 14(c) and 14(e). As a result, only the displacement angle VT1 of the intake camshaft 11 is increased to advance the valve timing of the intake valve 23 as shown in FIGS. 14(b) and 14(d). Between the timings t1 and t2, only the valve timing of the intake valve 23 is changed.
At timing t2, the absolute values |ΔVTFIN1|, |ΔVTFIN2| of the final deviations ΔVTFIN1, ΔVTFIN2 come to the states indicated by the point B in FIG. 12. Thus, the absolute value |ΔVTFIN1| of the final deviation ΔVTFIN1 becomes equal to the first determination value ΔJVT1. Consequently, the ECU 16 sets the value of the duty ratio DVT1 as the value of the sustaining duty ratio DVTH and computes the duty ratio DVT2 according to the final deviation ΔVTFIN2.
The ECU 16 then controls the OCVs 60, 80 based on the exciting signals VS1, VS2, which correspond to the duty ratios DVT1, DVT2. Accordingly, the oil amount Q1 supplied to the intake VVT 13 is decreased to "0" while the oil amount Q2 supplied to the exhaust VVT 14 is increased, as shown in FIGS. 14(c) and (e). As a result, the displacement angle VT2 of the exhaust camshaft 12 is increased to advance only the valve timing of the exhaust valve 24 as apparent from FIGS. 14(b) and (d). That is, only the valve timing of the exhaust valve 24 is changed between the timings t2 and t3.
Between the timings t1 and t2, only the valve timing of the intake valve 23 is changed so that the absolute value |ΔVTFIN1| of the final deviation ΔVTFIN1 is decreased to be equal to the determination value ΔJVT1, as shown in FIG. 12. As the absolute value |ΔVTFIN1| decreases, the duty ratio DVT1 is set to a smaller value, as shown in FIG. 7. This reduces the oil amount Q1 supplied to the intake VVT 13. Consequently, the rate of altering the valve timing of the intake valve 23 becomes slower. This reduces the rate of increasing the output torque.
Therefore, in this embodiment, the VVT to which oil is supplied from the oil pump 62 is switched to the exhaust VVT 14 from the intake VVT 13 to give priority to the alteration of the valve timing of the exhaust valve 24. This permits the output torque to be increased more than that in the case where priority is given to the alteration of the valve timing of the intake valve 23.
As shown in FIG. 12, between the timings t2 and t3, the absolute values |ΔVTFIN1| and |ΔVTFIN2| of the final deviations ΔVTFIN1 and ΔVTFIN2 proceed from point C to point B. As a result, the ECU 16 computes the duty ratios DVT1, DVT2 according to the respective final deviations ΔVTFIN1, ΔVTFIN2 at timing t3.
The ECU 16 then controls the OCVs 60, 80 based on the exciting signals VS1, VS2, which correspond to the duty ratios DVT1, DVT2, respectively. Accordingly, the predetermined oil amounts Q1, Q2 are supplied to the VVTs 13, 14, respectively, as apparent from FIGS. 14(c) and 14(e). As a result, both displacement angles VT1, VT2 are increased to advance the valve timings of the valves 23, 24, as shown in FIGS. 14(b) and 14(d). That is, between the timings t3 and t4, the valve timings of both valves 23 and 24 are changed.
The changes in the oil amounts Q1 and Q2 indicated by the double-dotted line in FIGS. 14(c) and 14(e) show changes in the oil amounts Q1 and Q2 when oil is supplied to only one of the VVTs 13, 14. As apparent from FIGS. 14(c) and 14(e), the oil amounts Q1, Q2 supplied to the VVTs 13, 14 (both indicated by the solid lines) are smaller than the oil amounts indicated by the double-dotted lines in this embodiment. The reason for this phenomenon will now be described.
In this embodiment, oil is supplied to the VVTs 13, 14 from the common oil pump 62. Thus, in the period starting at timing t3, the oil pumped out from the pump 62 is distributed to the VVTs 13, 14. As a result, the oil amounts Q1, Q2 supplied to the VVTs 13, 14 are reduced.
At timing t4, the final deviations ΔVTFIN1 and ΔVTFIN2 come to the states at the point D in FIG. 12 so that the final deviation ΔVTFIN1 becomes "0". That is, the displacement angle VT1 of the intake camshaft 11 reaches the target displacement angle VTT1 (=β) as indicated in FIG. 14(c). The ECU 16 therefore sets the value of the duty ratio DVT1 as the value of the sustaining duty ratio DVTH. Consequently, the oil amount Q1 supplied to the intake VVT 13 becomes "0", as shown in FIG. 14(b). Thus, during the period between timings t4 and t5, the valve timing of the intake valve 23 is sustained at the current timing while only the valve timing of the exhaust valve 24 is advanced.
As shown in FIG. 12, at timing t5, the final deviations ΔVTFIN1, ΔVTFIN2 proceeds to point E so that both final deviations ΔVTFIN1, ΔVTFIN2 become "0". That is, the displacement angles VT1, VT2 of the camshafts 11, 12, respectively, reach the associated target displacement angles VTT1, VTT2 (=β), as shown in FIGS. 14 (b) and 14(d). Consequently, the oil amounts Q1, Q2 of oil supplied to the VVTs 13, 14 become "0". Therefore, the valve timings of the valves 23 and 24 are sustained at the current timings.
The double-dotted line in FIG. 14(f) indicates changes in the absolute values |ΔVTFIN1|, |ΔVTFIN2| of the final deviations ΔVTFIN1, ΔVTFIN2, respectively, in the comparative example that is compared to this embodiment. In the comparative example, the absolute values |ΔVTFIN1|, |ΔVTFIN2| are linearly changed to the state indicated by point E from the state indicated by point A in FIG. 12.
More specifically, the oil discharged from the oil pump 62 is equally distributed to the VVTs 13, 14 in the comparative example. The amount of oil supplied to the VVTs 13, 14 become relatively smaller than in the case which oil is supplied to only one of the VVTs 13, 14. This slows the valve timing altering speed in comparison to when only one valve timing is altered.
However, in this embodiment, oil is supplied only to either one of the intake VVT 13 or the exhaust VVT 14 between the timings t1 and t3. Thus, sufficient amount of oil is supplied to both VVTs 13, 14. This embodiment enables the valve timings to be altered at sufficiently fast rates, and thus increases the output torque of the engine 10 more than in the comparative example.
Accordingly, as apparent from FIG. 14(f), this embodiment allows the output torque of the engine 10 to reach the target output torque TTRG more quickly than the comparative example (change in the output torque is indicated by the double-dotted line). It is thus possible to improve the responsiveness of the valve timing control.
Further, according to this embodiment, the absolute values |ΔVTFIN1|, |ΔVTFIN2| of the final deviations ΔVTFIN1, ΔVTFIN2 are respectively compared with determination values ΔJVT1, ΔJVT2 to accurately select the valve timing of either the valve 23 or the valve 24, whichever contributes more to increasing the output torque more significantly. Oil is then supplied to only one of the VVTs 13, 14 so that the priority is given only to the selected valve timing. It is thus possible to supply a sufficient amount of oil to one of the VVTs 13, 14 from the oil pump 62. This allows the selected valve timing to quickly increase the output torque of the engine 10.
Although only two embodiments of the present invention have been described herein, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms.
In the above-described embodiments, when controlling the individual valve timings, priority is given to the valve timing that increases the output torque of the engine 10 more. Instead of this structure, among the two valve timings, the valve timing that contributes more to suppressing the deterioration of emission may be selected and given priority for alteration. Likewise, the valve timing that contributes more to improving various characteristics of the engine 10, such as the fuel consumption and the idling stability, may be selected and given priority.
In the above-described embodiments, the valve timings of opening and closing both valves 23, 24 are changed. Instead, the valve performance control apparatus according to this invention may be adapted to an engine whose VVTs are designed to change only the timings of opening both valves 23 and 24 or only the timings of closing both valves 23 and 24.
In the first embodiment, the compensation deviations ΔVTK1, ΔVTK2 corresponding to the deviations ΔVT1, ΔVT2 are computed based on the function data shown in FIG. 6. The relation between the deviations ΔVT1, ΔVT2 and the compensation deviations ΔVTK1, ΔVTK2 may be stored as a function map in the ROM 86 for each engine speed NE and each manifold pressure PM. This enables the compensation deviations ΔVTK1, ΔVTK2 corresponding to the deviations ΔVT1, ΔVT2 to be computed based on the function map.
In the first embodiment, the valve timing of the intake valve 23 is changed by giving priority to the deviation ΔVT1 of the intake camshaft 11 when computing the compensation deviations ΔVTK1, ΔVTK2 from the deviations ΔVT1, ΔVT2, respectively. Function data as shown in FIG. 13 may however be stored in the ROM 86 so that the duty ratios DVT1 and DVT2 are calculated based on this function data.
In FIG. 13, the solid line shows the relation between the final deviation ΔVTFIN1 and the duty ratio DVT1, and the single-dotted line shows the relation between the final deviation ΔVTFIN2 and the duty ratio DVT2. As the duty ratios DVT1, DVT2 are computed based on the function data, the duty ratio DVT1 for controlling the intake OCV 60 is computed to be greater than the duty ratio DVT2 for controlling the exhaust OCV 80 even when the final deviations ΔVTFIN1, ΔVTFIN2 are the same. This further embodiment therefore changes the valve timing of the intake valve 23 by giving priority to the valve 23 that contributes more to increasing the output torque of the engine 10 in the same manner as the first embodiment.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | An apparatus for controlling valve performance of an internal combustion engine. The apparatus includes a first changing means for changing the valve performance of an intake valve. The first changing means is actuated by fluid pressure. A second changing means changes the valve performance of an exhaust valve. The second changing means is actuated by the fluid pressure. A fluid source is connected with the first changing means and the second changing means to supply fluid to the first changing means and the second changing means. An adjusting means adjusts the amount of the fluid supplied from the fluid source to the first changing means and the second changing means. A detecting means detects the running condition of the engine. A control means controls the adjusting means to change each valve performance so as to coincide the engine torque with the desired engine torque. The control means includes selecting means for selecting one of the valves based on the detected running condition of the engine. The selected valve is capable of coinciding the engine torque with the desired torque faster than the other one of valves to allow a larger amount of the fluid supplied to one of the changing means that is associated with the selected valve than the other one of the changing means. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to an injection molding method for manufacturing a thermoplastic part with thick and thin wall sections. The method inhibits the formation of surface defects, such as sink marks, which are typically present in such complex parts when manufactured by conventional injection molding method.
In the case of a large-sized part such as a housing for a TV set or a bumper for an automobile, the part must have structural strength as well as excellent surface appearance and dimensional accuracy. In order to obtain structural strength suitable for large parts, it is preferable that the part be designed to include thick wall sections which will reinforce the strength of the part. Hence, the structural integrity of the molded part will not be solely dependent upon the strength of the resin. These conflicting requirements often result in the sacrifice of appearance for strength or vice versa due to the dynamics of the conventional injection molding process.
When a part having both thick and thin wall sections is injection molded, the molten resin in the interior of the mold cavity is cooled and solidified at a slower rate than the exterior surface. Due to this delay of cooling and solidification, the volumetric shrinkage of the resin is likely to be accumulated in the more interior sections of the part. The accumulation of the volumetric shrinkage often causes the formation of sink marks which especially occur on the surface of the thick wall sections, deformations and other defects (which are hereinafter referred to as sink marks) of the part. Consequently, it is difficult to obtain a high quality surface in the molded part.
Due to this phenomenon, in a conventional injection molding process, parts are designed to avoid thick wall sections. When a part with thick wall sections must be manufactured by the conventional injection molding process, a dwelling step immediately after the injection of a molten resin into the cavity of a mold is performed. In the dwelling step, a dwelling pressure is applied to the molten resin existing in the cavity of the mold to maintain the packing density of the injected molten resin. However, when a part has a complicated configuration, a gate sealing precedes the completion of dwelling. As a result, sufficient dwelling pressure cannot be applied to the molten resin at a position far from a gate. The resulting part will not have a satisfactory surface appearance.
Japanese Patent Application Publication 61-53208, Japanese Patent Application Laid Open 63-268611 and Japanese Patent Application Laid Open 64-63122 disclose methods using a high-pressure gas as an auxiliary means of aiding the conventional injection molding process to inhibit the formation of sink marks. These methods comprise a two step process to inhibit surface defects in a molded part. In the first step, the molten resin, in an amount insufficient to fill the cavity of the mold is injected into the cavity. At the same time or after, high-pressure gas is injected into the molten resin to form a hollow portion through a resin flow passage. In the second step, the application of dwelling pressure derived from the high-pressure gas through the hollowed resin flow passage to the interior of the molten resin is maintained so that the molten resin in the cavity is cooled and solidified against the inner wall of the mold to inhibit the formation of surface defects.
However, when a part having a complicated configuration is to be manufactured, the thick wall portion(s) connected with a gate are likely to act as flow leaders for the molten resin, so that the supply of the molten resin to each portion of the mold cavity becomes unbalanced. The result of this unbalance is air traps and flow marks which result in surface defects on the part. In extreme cases, the high-pressure gas may break the surface layer of the solidifying resin part so that the injection molding cycle itself is interrupted and a defective part is manufactured. Moreover, there is a restriction on the design configurations of parts to which these methods are applicable. If a hollow portion sufficient to inhibit the formation of sink marks cannot be formed in the mold cavity, the formation of sink marks on the surface of the part will result. Thus, these methods are not satisfactory for insuring parts with superior surface appearance.
Japanese Patent Publication 48-41264 discloses another injection molding method using high-pressure gas as auxiliary means, when an article having a thick wall throughout the part is to be manufactured. In this method, after molten resin is injected into the cavity of a mold, a gas nozzle is directly projected into the molten resin in the cavity. High-pressure gas is supplied through the gas nozzle into the molten resin to perform the aforementioned first step while forming a hollow portion in the molten resin. This avoids the first step problems enumerated above. However, the configuration of a part to which this method is applicable is limited to uniformly thick wall sections. Moreover, this process requires a reciprocal carrying mechanism for inserting the gas nozzle into the molten resin during injection molding and withdrawing the gas nozzle from the solidified part. This method lacks in practicality, since it requires a driving mechanism with a withdrawing power larger than a constraining force derived from the shrinkage of the resin during solidification t remove the gas nozzle from the part.
Besides, these methods have significant problems such as the danger which accompanies the use and handling of high-pressure gas.
Japanese Patent Publication 61-9126 discloses the method wherein the cavity of a mold is filled with a molten resin, and the thick wall portion of the part is then pressed by a gas pressure from a position corresponding to the back side of the part. However, the direct application of the gas pressure causes the formation of irregular sink marks on the back surface of the part resulting in an unsatisfactory surface appearance.
When a resin such as polycarbonate or polymethyl-methacrylate, which set up quickly, is injection molded under conditions that permit the surface layer to rapidly cool and solidify, the formed surface layer of the part exhibits higher strength than the force derived from the volumetric shrinkage of the resin. Consequently, voids are formed in the thick wall portion of the part without deformation of the surface layer. In this case, sink marks are not formed on the surface of the thick wall portion.
The formation of these internal voids is regarded as a defect which causes a reduction of the strength in the part. However, this phenomenon of forming voids can be effectively controlled to inhibit the formation of sink marks, as disclosed in Japanese Patent Application Publication 2-13886. In this method, a void control member is projected through the inner surface of a mold into the cavity where sink marks are apt to form on the surface of the part. The void control member promotes the formation of a void in the resin body near the top end of the void control member, thereby inhibiting the formation of sink marks. This method has the advantage that the formation of sink marks can be inhibited by a simple, economical means.
However, the void control means must be made of a material having large heat capacity, so as to be held at a higher temperature in order to spontaneously form voids. Consequently, it is difficult to make the void control members smaller in size. The position where the void control members may be located in the mold are restricted, and the void control members cannot be held at a high temperature under a stable condition. As a result, it is difficult to ensure the thick wall sections of the part will be free of sink marks.
In addition, the positions where sink marks will be likely to be formed are irregularly affected by the molding conditions. For instance, the sink marks are formed at different positions during every molding cycle, even when the same part is manufactured. In this regard, it is difficult to predetermine the position where sink marks will b formed. The size and the configuration of the thick wall portion has an influence on the positions where sink marks are to be formed as well. Furthermore, in some resins, such as polycetal, the voids do not expand to the extent sufficient to compensate for the volumetric shrinkage of the resin, so that the formation of sink marks on the surface of a part cannot be completely eliminated.
An object of the present invention is to overcome the above-mentioned problems which causes defects in a molded part, and to obtain a molded part with excellent surface appearance, free from sink marks, even when the part has wall sections that vary significantly in thickness.
The present invention to realize the above-mentioned object is to induce a void in the portion near the top end of a void inducing member provided at position of each thick wall portion by the application of a gas pressure along the void inducing member, and then to make the void larger by the shrinkage force of the resin, without using a high-pressure gas which causes various defects. The present invention provides an injection molding method for manufacturing a thermoplastic part having thick and thin wall portions while inhibiting the formation of sink marks on the surface of the part. The steps in this process are:
1. providing at least one void inducing member having an acute top end at a position, corresponding to a thick wall portion where sink marks will be easily formed in a state that the acute top end is located in the cavity of the mold,
2. injecting molten resin in an amount sufficient to fill the cavity of the mold,
3. supplying compressed gas along the periphery of the void inducing member to the acute top end, wherein a resin skin layer is formed in contact with the top end of the void inducing member and is penetrated by the compressed gas, and one fine bubble serving as a void nucleus is formed in the molten resin, and
4. cooling and solidifying the resin, such that the void nucleus is expanded to a large void in response to the volumetric shrinkage of the resin by the shrinkage force of the resin during cooling and solidification.
The application of the gas pressure may be started just after the completion of the resin injection into the cavity of the mold or may be started after the dwelling step wherein the thermoplastic resin injected to fill the mold cavity is held at a predetermined pressure for a predetermined period. In this dwelling process, the molten resin is circulated to all parts of the mold cavity and the counter flow of the injected resin from the cavity to reduce the packing density is also inhibited.
After the void nucleus is formed in the molten resin at an inner part near the top end of the void inducing member by the application of the gas pressure, the application of the gas pressure to the void nucleus may be continued until the molten resin, at the part corresponding to the thick wall portion, loses its fluidity. Thereby, the shrinkage force of the molten resin during cooling and solidification effectively promotes the growth of the void nucleus up to a volume sufficiently corresponding to the volumetric shrinkage of the resin.
The mold to be used in this method has a cavity, comprising at least one large space, corresponding to the configuration of the part to be manufactured. The void inducing member is located in the cavity in such a manner that its acute top end is projected into the large space from the inner surface of the mold cavity. The void inducing member has a passage extending longitudinally along its surface for introducing the compressed gas. The void inducing member has the form of a simple pin, and is secured to the mold in the same manner that of other pins. The void inducing member can, thereby, be easily prepared and incorporated in the mold. In addition, the void inducing member may be used as a core pin of a sleeve ejector for ejecting the sleeve of the part from the mold.
The mold cavity is filled with molten resin, and then the gas pressure is applied to the molten resin along the periphery of the void inducing member projected into the mold cavity immediately after the resin injection or after the completion of the dwelling step. When the interior of the molten resin reaches a negative pressure owing to the volumetric shrinkage of the molten resin during cooling and solidification, the compressed gas breaks through the skin layer of the resin being formed around the acute top end of the void inducing member and a fine bubble is induced in the molten resin. The bubble acts as the void nucleus for the formation of the void. The pressure of the compressed gas which is applied is much lower than the above-mentioned conventional methods using high-pressure gas, since the interior of the molten resin is at the negative pressure and the resin skin layer near the top end of the void inducing member is still thin.
Once the void nucleus is formed, a volumetric shrinkage force derived from the cooling and solidification of the resin near the void inducing member is accumulated as negative pressure in the void nucleus, even if the application of the gas pressure is stopped. Consequently, the void nucleus acts as a seed for the growth of the void, and the void continuously becomes larger in volume while introducing the atmospheric gas through a hole formed at the top end of the void inducing member to compensate for the volumetric shrinkage of the resin. Thus, the function of the void to inhibit the formation of sink marks extends not only to the portion of the part near the void inducing member but also to the entire thick wall portion of the part. When the application of the gas pressure is continued, the gas pressure in combination with the volumetric shrinkage force of the resin effectively promote the growth of the void even though the compressed gas is being supplied at a very low pressure. Consequently, the formation of sink marks can be inhibited not only at the thick wall portion but also at an adjacent thick wall portion and at a thin wall portion near the thick wall portion.
The void inducing member has the acute top end which facilitates an accumulation of the gas pressure near the top end of the void inducing member to make the formation of the void nucleus easy. Owing to the acute top end, the formation of the void at a position in the resin can be reproduced with high reliability.
It is not necessary to increase the heat capacity of the void inducing member. On the contrary, the acute tip of the void inducing member has a small heat capacity.
The diameter of the void inducing member is not limited in particular, but preferably 1 to 5 mm to ensure the mechanical strength of the part. Where the acute top end of the void inducing member is inserted into the large space of the mold cavity, it is not necessary to locate the top end at the center of the large space. The projection of the void inducing member from the inner surface of the mold may be shorter in length similar to the diameter of the void inducing member. Consequently, the formation of the skin layer near the top end of the void inducing member is retarded, and the skin layer is held in a state which is easy to penetrate by the application of the gas pressure.
The resulting hole formed in the skin layer is very small in diameter, e.g. 0.5 mm or so, which is barely visible. Consequently, the appearance of the part is not effected by the formation of the hole.
The position for providing the void inducing member is not limited in particular, but may be located any place convenient with respect to the design of the mold. For instance, a sufficient effect is obtained even when the void inducing member is located near the circumference of the large space.
Consequently, the degree of freedom in designing a part is considerably greater than with the void control member disclosed in Japanese Patent Publication 2-13886. In addition, the void inducing member may have any configuration other than a column, as far as the gas pressure can be applied to the part of the resin near the top end of the void inducing member.
The pressure of the compressed gas to be applied is about 5 to 15 kg/cm 2 , which is much lower than that of high-pressure gas used as an auxiliary means in the conventional methods. For instance, the conventional injection molding methods using high-pressure gas disclosed in Japanese Patent Publication 57-14968 and Japanese Patent Publication 61-53208 use high-pressure gas compressed up to 150 kg/cm 2 for hollowing the thick wall portion. In the present invention, an air pressure of 10 kg/cm 2 or less will be sufficient in most cases, so that an ordinary gas supply source is usable. The gas flows along the periphery of the void inducing member and reaches the top end of the void inducing member, so that a slight gap is formed between the surface of the void inducing member and the resin skin layer. The slight gap acts as a gas passage to introduce the atmospheric gas into the void after the supply of compressed gas is stopped. As a result, the void inducing member can easily be extracted from the part, since the void inducing member is not captured by the part different from the method disclosed in Japanese Patent Publication 48-41264. Thus, it should be recognized that the method utilized in the present invention attains superior results over the other known methods.
The other objects and features of the present invention will be understood from the following description with reference to the drawings attached.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the whole body of a part obtained in an example.
FIG. 2 is a sectional side view of a metal die to be used in the present invention.
FIG. 3 is a sectional view for explaining the formation of a void nucleus.
FIG. 4 is a sectional view for explaining the growth of a void.
FIG. 5 is a perspective view of another example of a void inducing member.
FIG. 6 is a sectional view showing another example of a mold.
FIG. 7 is a graph showing the influence of gas pressure application time on the size of a void and the surface appearance of a part.
FIG. 8 is a graph showing the influence of timing on the application of gas pressure on the size of a void and the surface appearance of a part.
FIG. 9 is a table summarizing the results of examples.
FIG. 10 is a perspective view showing the entire body of a part obtained in another example.
FIG. 11 is a sectional view showing the means for attaching a void inducing member used as sleeve ejection.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The type of resin to be used for injection molding according to the present invention is not precisely defined. Any type of a thermoplastic resin such as polystyrene, polypropylene, ABS or polycarbonate, as well as a mineral or glass reinforced thermoplastic resin may be used. The present invention is particularly effective when applied to resins having large shrinkage rates, such as polypropylene or ABS. In these instances, the void inducing member effectively demonstrates its function to eliminate the formation of sink marks.
The void inducing member is located at the position corresponding to the thick wall portion of the part to be molded. When the thick wall portion is so large in size that the volumetric shrinkage of the entire thick wall portion cannot be absorbed by the formation of a void at one position, multiple void inducing members are arranged at proper intervals. The distance between adjacent void inducing members is determined by the relationship of the volume of the thick wall portion whose volumetric shrinkage can be compensated by the void originated by one void inducing member. In practice, enough void inducing members are arranged to offset the influence of molding conditions, especially the temperature of the resin, on the formation of the void.
A part having, for example, the configuration shown in FIG. 1 may be manufactured utilizing the present invention. The part (10) comprises a plate (11) as a thin wall portion and a rib (12) as a thick wall portion. A gate (13) formed by the sprue of a mold remains attached to the side surface of the plate (11). The gate (13) is cut off to obtain the finished part (10). The plate (11) may have, for example, a thickness of 3 mm, while the rib (12) has a thickness of 10 mm. Since the rib (12) has the greater thickness, sink marks are likely to be formed at surface portion (14, 15 and 16) of the rib (12) when the part (10) is manufactured by conventional injection molding methods.
A mold utilizing the present invention has the structure shown in FIG. 2. The mold (20) is comprised of a stationary part (22) and a movable part (23). The movable part (23) is clamped to the stationary part (22) to form a cavity (21) therebetween. A gate is positioned to permit injection of molten resin into the mold (20).
Void inducing members (30) ar placed to pass through the wall of the movable part (23). Each void inducing member (30) is in the form of a pin comprising an acute tip (31), a pin body (30b), a screw thread (38) and a flange (32). The void inducing member (30) is projected into the cavity (21) through a hole (24) formed in the movable part (23). The screw thread (38) is fixed in the movable part (23). The flange (32) is held in contact with the outside surface of the movable part (23). The top end of the acute tip (31), projecting from the inner surface of the movable part (23), is located at the central portion of the cavity (21).
The hole (24 formed through the wall of the movable part (23) comprises a large diameter portion (25) and a small diameter portion (26). The base portion of the void inducing member (30) is surrounded with the large diameter portion (25), which is connected with a compressed gas supply source (27) through a conduit (28) and a valve (29). The small diameter portion (26) is slightly larger in diameter than the void inducing member (30) to form an annular passage for compressed gas around the small diameter portion (26).
Molten resin (40) is injected into a cavity (21) of the mold (20) by an injection molding machine in order to fill the cavity of the mold (20), as shown in FIG. 3.
Immediately after the cavity (21) is filled with a molten resin (40), the valve (29) is opened to supply compressed gas from the ga supply source (27) through the conduit (28) to the holes (24). Since the compressed gas is used at ambient temperature and is supplied at a relatively low pressure, the compressed gas does not have any harmful influence on the part, such as oxidation, which may effect surface finish. In this regard, the use of compressed air is most advantageous from a cost and handling perspective. When the molten resin being cooled begins its volumetric shrinkage, the compressed gas supplied from the gas supply source (27) flows through a clearance between the small diameter portion (26) and the surface of the void inducing member (30), and reaches the top end of the void inducing member (30). The compressed gas is peeling off a resin skin layer (41) being formed around the acute tip (31) of the void inducing member (30), and the pressure of the compressed gas is concentrated at one point near the top end of the void inducing acute tip (31), as shown in FIG. 3. Since the cooling of the skin layer (41) is slower at a position nearer to the top end of the void inducing member (30), the skin layer (41) near the top end is maintained in a thinner state. Consequently, the compressed gas easily breaks through the thin skin layer (41) near the top end of the acute tip (31) and forms a hole (42) in the skin layer (41). The projection of the void inducing member (30) from the inner surface of the mold (20) is nearly similar in length to the diameter of the void inducing member (30). The volumetric shrinkage force generated in the resin body promotes the introduction of fine bubble from the outside through the hole (42) into the molten resin (40), thereby forming a void nucleus (43) serving as a seed for the growth of a void (44).
The application of the gas pressure may be stopped at this point. At the same time, the gas passage between the valve (29) and the surface of the resin body is communicated with the atmosphere, so that the residual gas is released from the gas passage to the atmosphere.
The compressed gas is not necessarily released. Since the continuation of the application of gas pressure in combination with the volumetric shrinkage of the resin body accelerates the growth of the void, the formation of sink marks can be inhibited not only at the thick wall portion but also at an adjacent thick wall portion and at a thin wall portion near the thick wall portion of the molded part.
As the resin (40) is cooled and solidified, the void nucleus (43) expands to a void (44) by the shrinkage force of the resin (40), as shown in FIG. 4. The void (44) increases in size as shown in reference I to II in the direction of the resin (40a) remaining in a molten state because of the delay in cooling and solidification. The growth of the void (44) is accompanied by the circulation of the molten resin near the void (44) and the surface enlargement of the void (44). When the viscosity of the molten resin increases as cooling process advances, the resistance of the resin to the circulation and the surface tension becomes balanced with the volumetric shrinkage force. As a result, the growth of the void (44) is stopped. In this regard, the continuation of the gas pressure application is effective until the molten resin loses its fluidity. After the resin (40) is completely solidified, the mold (20) is opened to remove a molded part.
The molded part has a configuration which corresponds to the cavity of the mold with a smooth surface free from sink marks at the surface portions most likely to encounter surface defects (14 to 16) since the volumetric shrinkage of the resin (40) is offset by the growth of the void (44).
The mold (20) may have a holding plate (23a) in addition to the stationary part (22) and the movable part (23), as shown in FIG. 6. The holding plate (23a) is fixed to the movable part (23), and each void inducing member (30a) is secured to the movable part (23). A conduit (28) for applying gas pressure is formed between the movable part (23) and the holding plate (23a), and connected with each hole (24). The void inducing members (30a) have the same function as the void inducing member (30) shown in FIG. 2.
FIG. 5 shows another example of the void inducing member (30). This void inducing member (30) has an axial hole (37) and a plurality of laterial holes (36). The lateral holes (36) are communicated with the axial hole (37) and with the large diameter portion (25) of the hole (24) shown in FIGS. 2 and 3. In this example, gas supplied from the source (27) flows through the lateral holes (24) into the axial hole (37), and then spouts from the opening of the top end of the void inducing member (30). Consequently, a void nucleus is formed in the resin.
A void inducing member may be also placed at the optional position of the mold using an attaching device shown in FIG. 11. This void inducing member (30a) is mounted to a bottom plate (53) secured to a movable part (23) through a spacer block (54). The void inducing member (30a) is inserted through a sleeve (55) supported by an ejector plate (56). A gas passage (57) formed between the void inducing member (30a) and the sleeve (55) is connected with the top end of the void inducing member (30a) projecting into the cavity (21a) from the inner surface of the movable part (23), and sealed by an O-ring (58) at the bottom. Compressed gas is supplied to the top end of the void inducing member (30a) through the conduit (60), a connector (61) and the passage (57).
This device facilitates the attachment of the void inducing member (30a), even at a position where it is difficult to attache the void inducing member by some other type of device. The attachment device is a simple mechanism which is easy to construct. In addition, the sleeve (55) may also act as an ejector for extracting a molded part from the mold. As a result, the mold assembly can be prepared at a low cost.
EXAMPLE I
A molded part having the configuration shown in FIG. 1 was obtained by injection molding using the mold shown in FIG. 2. The plate (11) of the part (10) was 3 mm in thickness, while the rib (12) was 230 mm in length and 10 mm in thickness. Three void inducing members (30) were incorporated at intervals of 100 mm in the movable part (23) of the mold (20). Each void inducing member (30) was of 2 mm in diameter.
The smaller diameter portion (26) located near the cavity (21) was slightly larger in diameter than the cross section of the void inducing member (30), to form a narrow annular gap between the inner surface of the smaller diameter portion (26) and the periphery of the void inducing member (30). The narrow annular gap was sized to inhibit the inflow of the molten resin being injected into the cavity (21) of the mold (20).
Molten polystyrene was injected into the cavity (21) of the mold (20) and then held for 3 seconds at a dwelling pressure. Immediately thereafter, compressed air of 9.5 kg/cm 2 at an ambient temperature was supplied from the compressed gas supply source (27) through the conduit (28) to the top end of each void inducing member (30). The application of the gas pressure to the resin (40) near the top end of each void inducing member (30) was continued for 8 seconds. The compressed air was then discharged to the atmosphere by opening the valve (29). After cooling for 60 seconds, the molded part was removed from the mold (20).
The part had a smooth surface, and no defects such as sink marks were detected on the surface of the part. A hole of approximately 0.5 mm in diameter was found at the part where the top end of each void inducing member (30) was inserted into the resin body. The formation of voids inside the part was detected at each portion inside the hole. Each void was relatively large in volume. However, the surface appearance of the resin part was not harmed by these holes and voids.
COMPARATIVE EXAMPLES (1) TO (3)
The following experiments were carried out in order to verify the effectiveness of the present invention.
(1) Polystyrene was injection molded using the mold shown in FIG. 2, under the same conditions as Example I without the application of a gas pressure. In this case, no void was formed in the molded part near the top end of each void inducing member (30). The molded part was inferior in surface appearance. Many sink marks were formed on the surface of the part at locations corresponding to the rib (12) and on the side surface of the part.
(2) A cylindrical pin made of steel (SK-4) having a diameter of 6 mm, as disclosed in Japanese Patent Publication 2-13886, was used as a void control member. Polystyrene was injection molded under the same conditions as Example 1 but using the void control member instead of the void inducing member. In this case, no void was formed. However, many sink marks were detected on the surface of the molded part. Consequently, the part was inferior in surface appearance. Other resins such as ABS, polycarbonate and PMMA were used in addition to polystyrene, and the results were the same.
(3) The compressed gas was applied to molten resin (40) injected into the cavity (21) of the mold (20) for 3 seconds during the dwelling step under the same conditions as those in the Example I. At the completion of dwelling, the supply of the compressed gas was stopped, and the gas was discharged through the valve (29) to the atmosphere. The injected polystyrene was cooled and solidified with the conduit (28) for the circulation of the compressed gas being opened to the atmosphere. In this case, no void was formed in the molded part, and many sink marks were detected on the surface of the part. Again, the molded part was inferior in surface appearance.
In another experiment, the application of gas pressure was continued from resin injection through a dwelling step under the same conditions as Example 1. The supply of the compressed gas was stopped at the beginning of the cooling step. When the polystyrene was cooled and solidified under this condition, the formation of sink marks was detected on the surface of the molded part. The part had a poor surface appearance.
EXAMPLE II (1)-(2)
(1) Injection molding was performed under the same conditions as the Example 1, but the time period of application of gas pressure to the injected resin during the cooling step was changed in each experiment to investigate the influence of the gas pressure application time on the size of the void formed in the part.
The results are shown in FIG. 7. It was observed that the formation of the void nucleus began within 5 seconds of the start of application of the gas pressure. It was also observed that the growth of the void was enhanced when the application of gas pressure was continued after the formation of the void nucleus. When the surface appearance of the part was examined in detail, it was observed that the volume of the void had a proportional relationship with the improvement of the surface appearance of the part.
(2) In order to begin the formation of the void at the earliest possible time and to synchronize the growing speed of a solidified resin layer with the growing speed of the void, the application of the gaseous pressure was started immediately after the cavity (21) of the mold (20) was completely filled with molten polystyrene without being held in the dwelled state. Owing to the earlier start of the gas pressure application, the void grew larger in volume than the void with dwelling, and the surface appearance of a part was further improved. Thus, it was recognized that the dwelling was not necessarily required.
The weight of the part with the dwelling was 133.9 g, while the weight without dwelling was 131.2 g. By contrast, the application of the gas pressure did not make any substantial change in weight of the part.
EXAMPLE III (1)-(3)
(1) A part having a configuration similar to that of the part in Example I (see FIG. 1) was utilized in Example III. The part had a rib (12) formed at the central surface of the back side of a plate (11). The plate (11) was 2 mm in thickness, while the rib (12) was 6 mm in thickness and 230 mm in length. The rib (12) had a thick wall portion considerably smaller in thickness than that of the Example I. When this part was manufactured by conventional injection molding, many sink marks were formed on the surface portions (14-16) of the plate (11) corresponding to the rib (12). In order to inhibit the formation of sink marks, three void inducing members were incorporated at intervals of 100 mm in the movable part (23) of the mold (20). Each void inducing member (30) had a diameter of 2 mm.
Injection molding was performed using this mold (20), while setting the cooling time at 40 seconds. The other conditions were the same as those in the Example I. A hole of approximately 0.5 mm in diameter was formed in the part at a location corresponding to the top end of each void inducing member. The formation of a void connected with each hole was observed in the part. When the surface appearance of the part was observed, no defects such as sink marks were detected, as in the case of the Example I.
(2) In another embodiment, the gas pressure was applied only to the left-side void inducing member (30) of FIG. 2 but not to the center and right-side void inducing members. The other molding conditions were held constant with Example I. In this case, the part had the surface portions (14 and 15) free from sink marks, while the formation of some sink marks was detected on the other surface portion (16).
(3) The application of the gas pressure was continued until the end of the cooling period, while omitting the dwelling step. The other molding conditions were held constant. No sink marks were detected in the part on the surface portion (16) or the other surface portions (14 and 15).
EXAMPLE IV
In the Examples I and III, the gas pressure was applied to the top end of the void inducing member immediately after the cooling period started. In Example IV, the application of the gas pressure was delayed by different time periods after the cooling period started. The relationship of the delay time with the volume of the formed voids and the surface appearance of the part was compared under the same conditions as those in the Example II. The results are shown in FIG. 8. It should be noted that the volumetric shrinkage of the resin causing the formation of sink marks was insufficiently compensated by the growth of the voids, when the growth of a solidified resin layer preceded that of the voids. Consequently, the surface appearance of the part was only partially improved.
The results in the Examples I through IV and the Comparative Examples are summarized in FIG. 9.
EXAMPLE V
A part having a complicated configuration shown in FIG. 10 was utilized in Example V. The part had thin wall portions (51) and thick wall portions (52) variously different in thickness from each other. When such a part was injection molded, many void inducing members were inserted into the cavity through the wall of a mold at positions corresponding to the parts indicated by the marks × and +. A void inducing member was set at each part designated by the mark x by the attaching device shown in FIG. 11, while another void inducing member was set at each part designated by the mark+using the holding plate (23a).
After the cavity of the mold was filled with molten resin, gas pressure was immediately applied to the molten resin. The part was ejected from the mold after being cooled and solidified.
The part had excellent surface appearance without the defects such as sink marks on its surface, despite its complicated configuration.
In accordance with the present invention, at least one void inducing member is provided at the position of the mold corresponding to each thick wall portion of the part. After the cavity of the mold is filled with molten resin, compressed gas is supplied to the top end along the periphery of the void inducing member. The skin layer being formed near the tip end of the void inducing member is penetrated by the application of gas pressure, and fine bubble which function as a void nucleus is induced into the part near the top end. The void nucleus expands to a void which becomes larger in response to the volumetric shrinkage of the resin during the cooling and solidification step. Consequently, the part has an excellent surface appearance free from sink marks. This occurs even when the part has a complicated configuration comprising both very thick and thin wall portions.
According to the present invention, a part of good quality, free from sink marks can be obtained while omitting the dwelling step. It is possible to use a molding machine having a smaller clamping force, as compared with conventional injection molding methods where injection and dwelling are performed at high pressure to inhibit the formation of sink marks. In this regard, there is also the advantage that molded in stresses in the part can be suppressed. In addition, the formation of the void is not accompanied with the unnatural circulation of the resin, e.g. the extrusion of an unsolidified resin from the center of the thick wall portion, to form the hollow portion in the thick wall. Consequently, the injection molding process is performed quite easily without the necessity of a special high-pressure gas source which is difficult to handle.
While the preferred embodiment of the present invention has been shown and described, it is to be understood that these disclosures are for the purpose of illustration and that various changes and modifications may be made without deviating from the scope of the invention as set forth in the appended claims. | When injection-molding a molten thermoplastic resin into a molding having different thicknesses, a void inducing member is set in a cavity corresponding to heavy sections. Then gas pressure is applied passing through a gas passageway to a tip end of the void inducing member, thus forming a void nucleus in the resin adjacent to the tip end of the void inducing member. The void nucleus develops to a void by shrinking force of the resin as the molten resin cools. | 1 |
RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. § 119(e) of U.S. provisional application 60/932,437, filed May 31, 2007, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a novel reference plant, a method for producing a novel reference plant, extracts free of a medicinally active compound or group of compounds obtained therefrom and their use. More particularly, the novel reference plant is a plant derived from a comparator plant. In an exemplifying embodiment the medicinal compounds, which are “knocked out”, are one or more cannabinoids and the plant is cannabis, Cannabis sativa, plant.
BACKGROUND OF THE INVENTION
[0003] Many pharmaceuticals are derived from plants and indeed many plants or extracts obtained therefrom are taken as medicines. There are over 120 distinct chemical substances derived from plants that are considered as important drugs that are currently in use. The table below lists some of these substances.
[0004] There are many examples of plant-based substances that are known for their medicinal properties. For example a tropical plant, Cephaelis ipecacuanha , is known to produce the chemical emetine. A drug was developed from this substance called Ipecac; this was used for many years to induce vomiting. Another example of plant-based substances used as medicines is the plant chemical named taxol found in the Pacific Yew tree. The taxol molecule was produced synthetically to produce the drug PACLITAXEL™, which is used in the treatment of various types of tumours.
[0005] The plant substance, cynarin, is a plant chemical found in the common artichoke ( Cynara scolymus ). A cynarin drug is sold for the treatment of liver problems and hypertension. The drug is simply an extract from the artichoke plant that has been standardized to contain a specific amount of cyanarin. Similarly the substance silymarin is a chemical found in the milk thistle plant and natural milk thistle extracts that have been standardized to contain specific amounts of silymarin are also used for the treatment of liver problems.
[0006] Some of the drugs/chemicals shown in the table below are sold as plant based drugs produced from processing the plant material. Many plant chemicals cannot be completely synthesised in the laboratory due to the complex nature of the plant extract. For example the tree Cinchona ledgeriana produces the substance quinine, which is used in to treat and prevent malaria. Quinine is now chemically synthesised; however, another chemical in the tree called quinidine, which was found to be useful for the treatment of heart conditions, couldn't be completely copied in the laboratory. The tree bark is used to produce a quinidine extract.
[0007] The table below details some of the plant-based medicines that are in use today.
[0000]
Drug/Chemical
Action/Clinical Use
Plant Source
Acetyldigoxin
Cardiotonic
Digitalis lanata
Adoniside
Cardiotonic
Adonis vernalis
Aescin
Anti-inflammatory
Aesculus hippocastanum
Aesculetin
Anti-dysentery
Frazinus rhychophylla
Agrimophol
Anthelmintic
Agrimonia supatoria
Ajmalicine
Circulatory Disorders
Rauvolfia sepentina
Allantoin
Wound healing
Several plants
Allyl isothiocyanate
Rubefacient
Brassica nigra
Anabesine
Skeletal muscle relaxant
Anabasis sphylla
Andrographolide
Baccillary dysentery
Andrographis paniculata
Anisodamine
Anticholinergic
Anisodus tanguticus
Anisodine
Anticholinergic
Anisodus tanguticus
Arecoline
Anthelmintic
Areca catechu
Asiaticoside
Wound healing
Centella asiatica
Atropine
Anticholinergic
Atropa belladonna
Benzyl benzoate
Scabicide
Several plants
Berberine
Bacillary dysentery
Berberis vulgaris
Bergenin
Antitussive
Ardisia japonica
Betulinic acid
Anticancerous
Betula alba
Borneol
Antipyretic, analgesic,
Several plants
anti-inflammatory
Bromelain
Anti-inflammatory,
Ananas comosus
proteolytic
Caffeine
CNS stimulant
Camellia sinensis
Camphor
Rubefacient
Cinnamomum camphora
Camptothecin
Anticancerous
Camptotheca acuminata
(+)-Catechin
Haemostatic
Potentilla fragarioides
Chymopapain
Proteolytic, mucolytic
Carica papaya
Cissampeline
Skeletal muscle relaxant
Cissampelos pareira
Cocaine
Local anaesthetic
Erythroxylum coca
Codeine
Analgesic, antitussive
Papaver somniferum
Colchiceine amide
Anti-tumour agent
Colchicum autumnale
Colchicine
Anti-tumour agent,
Colchicum autumnale
anti-gout
Convallatoxin
Cardiotonic
Convallaria majalis
Curcumin
Choleretic
Curcuma longa
Cynarin
Choleretic
Cynara scolymus
Danthron
Laxative
Cassia species
Demecolcine
Anti-tumour agent
Colchicum autumnale
Deserpidine
Antihypertensive,
Rauvolfia canescens
tranquillizer
Deslanoside
Cardiotonic
Digitalis lanata
L-Dopa
Anti-parkinsonism
Mucuna species
Digitalin
Cardiotonic
Digitalis purpurea
Digitoxin
Cardiotonic
Digitalis purpurea
Digoxin
Cardiotonic
Digitalis purpurea
Emetine
Amoebicide, emetic
Cephaelis ipecacuanha
Ephedrine
Sympathomimetic,
Ephedra sinica
antihistamine
Etoposide
Anti-tumour agent
Podophyllum peltatum
Galanthamine
Cholinesterase inhibitor
Lycoris squamigera
Gitalin
Cardiotonic
Digitalis purpurea
Glaucarubin
Amoebicide
Simarouba glauca
Glaucine
Antitussive
Glaucium flavum
Glasiovine
Antidepressant
Octea glaziovii
Glycyrrhizin
Sweetener, Addison's
Glycyrrhiza glabra
disease
Gossypol
Male contraceptive
Gossypium species
Hemsleyadin
Bacillary dysentery
Hemsleya amabilis
Hesperidin
Capillary fragility
Citrus species
Hydrastine
Hemostatic, astringent
Hydrastis canadensis
Hyoscyamine
Anticholinergic
Hyoscyamus niger
Irinotecan
Anticancer, anti-tumour
Camptotheca acuminata
agent
Kaibic acud
Ascaricide
Digenea simplex
Kawain
Tranquillizer
Piper methysticum
Kheltin
Bronchodilator
Ammi visaga
Lanatosides A, B, C
Cardiotonic
Digitalis lanata
Lapachol
Anticancer, anti-tumour
Tabebuia species
a-Lobeline
Smoking deterrant,
Lobelia inflata
respiratory stimulant
Menthol
Rubefacient
Mentha species
Methyl salicylate
Rubefacient
Gaultheria procumbens
Monocrotaline
Anti-tumour agent
Crotalaria sessiliflora
(topical)
Morphine
Analgesic
Papaver somniferum
Neoandrographolide
Dysentery
Andrographis paniculata
Nicotine
Insecticide
Nicotiana tabacum
Nordihydro-
Antioxidant
Larrea divaricata
guaiaretic acid
Noscapine
Antitussive
Papaver somniferum
Ouabain
Cardiotonic
Strophanthus gratus
Pachycarpine
Oxytocic
Sophora pschycarpa
Palmatine
Antipyretic, detoxicant
Coptis japonica
Papain
Proteolytic, mucolytic
Carica papaya
Papavarine
Smooth muscle relaxant
Papaver somniferum
Phyllodulcin
Sweetner
Hydrangea macrophylla
Physostigmine
Cholinesterase Inhibitor
Physostigma venenosum
Picrotoxin
Analeptic
Anamirta cocculus
Pilocarpine
Parasympathomimetic
Pilocarpus jaborandi
Pinitol
Expectorant
Several plants
Podophyllotoxin
Anti-tumour, anticancer
Podophyllum peltatum
agent
Protoveratrines A, B
Antihypertensive
Veratrum album
Pseudoephredrine*
Sympathomimetic
Ephedra sinica
Pseudoephedrine,
Sympathomimetic
Ephedra sinica
nor-
Quinidine
Antiarrhythmic
Cinchona ledgeriana
Quinine
Antimalarial, antipyretic
Cinchona ledgeriana
Quisqualic acid
Anthelmintic
Quisqualis indica
Rescinnamine
Antihypertensive,
Rauvolfia serpentina
tranquillizer
Reserpine
Antihypertensive,
Rauvolfia serpentina
tranquillizer
Rhomitoxin
Antihypertensive,
Rhododendron molle
tranquillizer
Rorifone
Antitussive
Rorippa indica
Rotenone
Piscicide, Insecticide
Lonchocarpus nicou
Rotundine
Analgesic, sedative,
Stephania sinica
tranquilizer
Rutin
Capillary fragility
Citrus species
Salicin
Analgesic
Salix alba
Sanguinarine
Dental plaque inhibitor
Sanguinaria canadensis
Santonin
Ascaricide
Artemisia maritma
Scillarin A
Cardiotonic
Urginea maritima
Scopolamine
Sedative
Datura species
Sennosides A, B
Laxative
Cassia species
Silymarin
Antihepatotoxic
Silybum marianum
Sparteine
Oxytocic
Cytisus scoparius
Stevioside
Sweetener
Stevia rebaudiana
Strychnine
CNS stimulant
Strychnos nux - vomica
TAXOL ®
Anti-tumour agent
Taxus brevifolia
Teniposide
Anti-tumour agent
Podophyllum peltatum
Tetra-
Antiemetic, decrease
Cannabis sativa
hydrocannabinol
ocular tension
Tetrahydropalmatine
Analgesic, sedative,
Corydalis ambigua
tranquilizer
Tetrandrine
Antihypertensive
Stephania tetrandra
Theobromine
Diuretic, vasodilator
Theobroma cacao
Theophylline
Diuretic, bronchodilator
Theobroma cacao and
others
Thymol
Antifungal (topical)
Thymus vulgaris
Topotecan
Anti-tumour, anticancer
Camptotheca acuminata
agent
Trichosanthin
Abortifacient
Trichosanthes kirilowii
Tubocurarine
Skeletal muscle relaxant
Chondodendron
tomentosum
Valapotriates
Sedative
Valeriana officinalis
Vasicine
Cerebral stimulant
Vinca minor
Vinblastine
Anti-tumour,
Catharanthus roseus
Antileukemic agent
Vincristine
Anti-tumour,
Catharanthus roseus
Antileukemic agent
Yohimbine
Aphrodisiac
Pausinystalia yohimbe
Yuanhuacine
Abortifacient
Daphne genkwa
Yuanhuadine
Abortifacient
Daphne genkwa
[0008] There are many examples of extracts that are characterized by reference to a supposed active or marker. The principle described herein with reference to cannabis plants would thus be applicable to other plant types as are shown in the table above.
[0009] As an example of a botanical drug, Cannabis sativa has been used as a drug for centuries, although the precise basis for the plants activity is not known. Both THC and CBD, two of the plants cannabinoids, are known to have distinct pharmacological activities and Marinol® (THC) and Sativex® (an extract containing defined amounts of both THC and CBD) are approved products for various medical indications.
[0010] In the case of extracts it is of course unclear whether the efficacy of a botanical drug extract is attributable to the identified “active(s)” or “markers” and/or other components present in an extract which may provide an unidentified additive or synergistic effect or in fact be directly responsible for the activity.
[0011] In the case of cannabis the supposed actives, the cannabinoids, are produced through a series of enzymatic synthesis which are outlined below:
[0012] The first specific step in the pentyl cannabinoid biosynthesis is the condensation of a terpenoid moiety, geranylpyrophosphate (GPP), with the phenolic moiety, olivetolic acid (OA; 5-pentyl resorcinolic acid), to form cannabigerol (CBG). This reaction is catalysed by the enzyme geranylpyrophosphate:olivetolate geranyltransferase (GOT); [1]. Precursors for GPP are the C 5 isomers isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). These compounds can originate from two different pathways:
the mevalonate pathway (MVA) that is located in the cytoplasm; and the deoxyxylulose pathway (DOX) that operates in the plastid compartments.
[0015] According to Fellermeier et al. [2], the GPP incorporated into cannabinoids is derived predominantly, and probably entirely, via the DOX pathway of the glandular trichome plastids. The phenolic moiety OA is generated by a polyketide-type mechanism. Rahaijo et al. [3] suggest that n-hexanoyl-CoA and three molecules of malonyl-CoA condense to a C 12 polyketide, which is subsequently converted into OA by a polyketide synthase.
[0016] CBG is the direct precursor for each of the compounds THC [4], CBD [5] and CBC [6], [7] and [8]. The different conversions of CBG are enzymatically catalysed, and for each reaction an enzyme has been identified: THC acid synthase [4] CBD acid synthase [5] and CBC acid synthase [7] and [8].
[0017] Cannabinoids with propyl side chains, as identified by Vree et al. [9] and de Zeeuw et al. [10], result if GPP condenses with divarinic acid (DA; 5-propyl resorcinolic acid) instead of OA, into cannabigerovarin (CBGV). The condensation of n-hexanoyl-CoA and two, instead of three, molecules of malonyl-CoA, results in a C 10 polyketide, which is subsequently cyclisised into DA by a polyketide [11]. The three cannabinoid synthase enzymes are not selective for the length of the alkyl side chain and convert CBGV into the propyl homologues of CBD, THC and CBC, which are indicated as cannabidivarin (CBDV), delta 9-tetrahydrocannabivarin (THCV) and cannabichromevarin (CBCV), respectively [12].
SUMMARY OF THE INVENTION
[0018] The above pathway information is provided, as it will assist in an understanding of the probable mechanism—giving rise to the zero cannabinoid plants exemplifying the broader aspects of the invention.
[0019] Indeed it would be particularly useful to develop “knock out” plants in which the one or more “actives” or “markers” believed to be characteristic of a plants pharmaceutical activity are not expressed. Such plants would be useful in formulating “true” placebo extracts or comparator extracts for clinical trials and for producing extracts which could be used in pharmacological tests and experiments in order that a better understanding of an extract, and its perceived actives/markers activity.
[0020] In the case of cannabis, the plant produces a vast array of cannabinoids (including THC and CBD—the main perceived cannabinoid actives) as well as a number of ‘entourage’ compounds. Entourage compounds are compounds which are related to cannabinoids but have little or no activity at the cannabinoid receptors. Such entourage compounds are thought to behave as modifiers of cannabinoid activity and therefore could enhance pharmacological efficacy. It would be useful to have a plant which did not produce the cannabinoids BUT which produced the entourage compounds and other significant compounds in combinations/amounts which at least substantially qualitatively and preferably also substantially quantitatively resembled that of a comparator plant, i.e. one which chemotypically bears a recognizable resemblance to the medicinal plants used to generate a pharmaceutical or medicine or a nutraceutical or functional food.
[0021] According to a first aspect of the present invention there is provided a reference plant which has been selected to:
a. not express a medicinally active compound or group of compounds; yet express, at least substantially qualitatively, most other non medicinally active compounds present in a therapeutically active comparator plant such that the reference plant can be used to generate a reference extract with a reference chemical profile which resembles that of the comparator plant less the active compound or group of compounds and may thus be used as a placebo or to otherwise test the hypothesis that the active compound or compounds are responsible for an extracts perceived medicinal activity.
[0024] The term “most other” is taken herein to refer to an amount of non medicinally active compounds expressed by the reference plant which is at least greater than 50% (w/w) of the total compounds in the plant. In specific embodiments the amount is greater than 60% (w/w) non medicinally active compounds, or the amount is greater than 70% (w/w) non medicinally active compounds, or the amount is greater than 80% (w/w) non medicinally active compounds, or the amount is greater than 90% (w/w) non medicinally active compounds, or the amount is greater than 95% (w/w) non medicinally active compounds.
[0025] Preferably the reference plant is a cannabis plant and the active compound or group of compounds are the cannabinoids.
[0026] The cannabis plant is preferably a Cannabis sativa plant containing a monogenic mutation that blocks the cannabinoid biosynthesis. Preferably the plant comprises a cannabinoid knock out factor governing a reaction in the pathways towards the phenolic moieties olivetolic and divarinic acid.
[0027] Significantly, the reference plant is characterised in that a homogenised bulk extract exhibits a profile of entourage compounds, which is quantitatively substantially similar to that of a reference plant; as for example is shown in FIG. 3 .
[0028] In one embodiment the homogenised bulk extract has a % v/w oil yield of greater than 0.14%, more preferably greater than 0.2%, through 0.3% to 0.4% or more.
[0029] A homogenised bulk steam distilled extract comprises both monoterpenes and sesquiterpines. The monoterpenes comprise detectable amounts of at least myrcene, alpha pinene and beta pinene. Preferably the combined myrcene, alpha pinene and beta pinenes comprise at least 50%, through 60% to at least 70% of the monoterpenes detected. Preferably it will also comprise one or more of limonine and optionally linalool and cis- and/or trans-verbenol.
[0030] The sesquiterpenes preferably comprise at least carophyllene and humulene and may further comprise carophyllene oxide.
[0031] Preferably humelene epoxide II is not detected in the reference plant.
[0032] The reference plants of the invention preferably comprise stalked glandular trichomes. These are present at a density comparable to those present in comparator drug type cannabinoid producing plants. The reference plants typically have small, grey, dull trichomes of various shapes ( FIG. 2 a ). Some trichomes comprise headless; pinhead and/or shrivelled trichomes, which may be, flat, convex or concave. They are also free of white trichome heads.
[0033] The reference plant may be further characterized in that it expresses monoterpenes, diterpenes, carotenoids, phytol and tetraterpenes. It additionally expresses sesquiterpenes, sterols and triterpenes.
[0034] The reference plant is further characterized in that it exhibits branching characteristic of a drug producing phenotype as opposed to a fibre producing phenotype and vigour, characterized in that the total above ground dry weight is comparable to drug producing phenotypes.
[0035] According to a further aspect of the present invention there is provided a method of producing a reference plant which does not express a medicinally active compound or group of compounds yet express, at least substantially qualitatively, most other non medicinally active compounds present in a therapeutically active comparator plant comprising:
a) Selecting a plant which does not express a medicinally active compound or group of compounds; b) Selecting a therapeutically active comparator plant; and c) Crossing the plant which does not express a medicinally active compound or group of compounds with the therapeutically active comparator plant to obtain an F1 progeny and self-crossing the F1 progeny to obtain an F2 progeny which is selected for the characteristics sought.
[0039] According to yet a further aspect of the present invention there is provided an extract obtainable from a reference plant of the invention.
[0040] According to yet a further aspect of the present invention there is provided an extract obtainable from a reference plant of the invention. Such extracts may be prepared by any method generally known in the art, for example by maceration, percolation, vaporisation, chromatography, distillation, recrystallisation and extraction with solvents such as C1 to C5 alcohols (ethanol), Norflurane (HFA134a), HFA227 and supercritical or subcritical liquid carbon dioxide. In particular embodiments the extracts may, for example, be obtained by the methods and processes described in International patent application numbers WO02/089945 and WO 2004/016277, the contents of which are incorporated herein in their entirety by reference.
[0041] In one embodiment the extract is used or formulated as a placebo. In particular embodiments such formulations and/or placebos may, for example, be formulated as described International patent application numbers WO01/66089, WO02/064109, WO03/037306 and WO04/016246, the contents of which are incorporated herein in their entirety by reference.
[0042] According to a further aspect of the present invention there is provided a method of testing a hypothesis that one or more compounds present in a plant extract are responsible or are solely responsible for the extracts pharmacological activity comprising:
i) selecting a plant according to the first aspect of the invention; ii) obtaining an extract therefrom; and iii) running comparative tests against the extract obtained from a comparator plant.
[0046] According to a further aspect of the present invention there is provided a method of producing a designer plant extract comprising the steps of:
i) selecting an extract obtainable from a reference plant according to the first aspect of the invention and ii) combining the extract of (i) with one or more medicinally active components.
[0049] By “designer plant extract” is meant a plant extract which includes one or more medicinally active components which do not naturally occur in the reference plant of part i).
[0050] In specific embodiments, the medicinally active components may be purified naturally occurring compounds, synthetic compounds or a combination thereof. In a specific embodiment the medicinally active components may be present in a plant extract. This plant extract may be an extract from a “drug producing” plant of the same species as the reference plant of part i). Typically this drug producing plant will not be the comparator plant to the reference plant of part i).
[0051] The invention is further described, by way of example only, with reference to novel Cannabis sativa plants (and not specific varieties), which do not express cannabinoids but which otherwise, resemble, chemotypically, medicinal cannabis plants.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] The invention will be further described, by way of example only to the following figures in which:
[0053] FIGS. 1 a - d are GC chromatograms from different chemotype segregants from a 2005.45.13 F 2. progeny (Table 2)
a: is from cannabinoid-free plants; b: is from low content and THC predominant plants; c: is from high content and THC predominant plants; and d: is from high content and CBG predominant plants.
The peaks at 8.2, 16.0 and 16.7 min. represent the internal standard, THC and CBG, respectively;
[0058] FIG. 2 a - d are microscopic images of the bracteole surfaces from different chemotype segregants from the 2005.45.13 F 2 progeny.
a: is from cannabinoid-free plants; b: is from low content and THC predominant plants; c: is from high content and THC predominant plants; and d: is from high content and CBG predominant plants.
(The bar represents 500 μm) and
[0063] FIG. 3 shows graphically, the chemical profile (both qualitatively and quantitatively) of respectively:
Top—a high cannabinoid bulk segregant; Middle—a cannabinoid free bulk segregant of the invention; and Bottom—a pharmaceutical production comparator (M3).
DETAILED DESCRIPTION OF THE INVENTION
[0067] By way of introduction it should be noted that there are many different Cannabis sativa varieties and chemotypes. These include both wild type plants and cultivated varieties. The cultivated varieties include plants which have been cultivated as fibre producers (low THC varieties); those that have been bred (illegally) for recreational use (high THC) and more recently medicinal plants which have been selectively bred for their cannabinoid content (one or more cannabinoids predominate) and optionally the profile of e.g. entourage compounds.
[0068] In order to produce plants with the desired characteristics it was necessary to “knock out” the expression of cannabinoids in a manner, which did not detrimentally effect the production of e.g. entourage compounds in the medicinal plants. How this was achieved is set out below:
Identification of a Cannabinoid-Free Chemotype Plant.
[0069] Because in many countries cannabis cultivation is restricted to fibre hemp cultivars having specified “low” levels (typically below either 0.1 or 0.3% w/w of the dry floral tissue) of THC, several breeding programmes have been devoted to meeting these legal limits.
[0070] According to a survey of the European commercial fibre cultivars [13], the cultivars bred at the Ukrainian Institute of Fibre Crops (Glukhov, formerly, Federal Research Institute of Bast Crops) have the lowest THC contents and the lowest total cannabinoid contents. The cannabinoid breeding programme at this institute started in 1973. Their usual selective breeding methodology consists of family selection within existing cultivars with a high agronomic value and the elimination, before flowering, of plants with relatively high contents [14] and [15]. This effort has resulted in a gradual decrease of both THC content and total cannabinoid content.
[0071] Gorshkova et al. [16] evaluated the densities of sessile and stalked glandular trichomes on the bracteoles of various plants. They found that plants with stalked trichomes had relatively high cannabinoid contents and that their contents were positively correlated with the density of the stalked trichomes. Plants that had solely sessile trichomes always had low contents that were uncorrelated with the densities of the sessile trichomes. Gorshkova et al. [16] also mention plants without glandular trichomes that were found to be cannabinoid-free.
[0072] Since then, Ukrainian plant breeders have reported several times on the existence of cannabinoid-free breeding materials [15], [17] and [18]
[0073] Pacifico et al. [1,9] analysed individual plants from the Ukrainian cultivar USO 31 and found that one third of the individuals contained no cannabinoids. He also found that a minority of the plants (<10%) in a French fibre cultivar, Epsilon 68, were cannabinoid-free.
[0074] The Ukrainian cultivar USO 31 is amongst several varieties of hemp that have been approved for commercial cultivation under subsection 39(1) of the Industrial Hemp Regulations in Canada for the year 2007.
[0075] These cannabinoid free plants are phenotypically and chemotypically different to those developed by the applicant through artificial manipulation and differ from those cannabinoid free plants that have been isolated in nature.
[0076] Theoretically, two different physiological conditions could make a plant cannabinoid-free:
(1) a disrupted morphogenesis of glandular trichomes that, according to Sirikantaramas et al. [20], appear to be essential structures for cannabinoid synthesis, and (2) a blockage of one or more biochemical pathways that are crucial for the formation of precursors upstream of CBG.
[0079] The first condition would also seriously affect the synthesis of other secondary metabolites that are produced largely or uniquely in the glandular trichomes.
[0080] In 1991, field grown cannabinoid-free plants, resulting from Gorshkova et al. [16] programme were viewed and the bracts and bracteoles of these plants were apparently lacking glandular trichomes. Also, the plants did not exude the characteristic cannabis fragrance. This suggests that the volatile mono- and sesquiterpenes were not produced in these plants. Such cannabinoid free plants might therefore have been considered unsuitable for the purpose of breeding a cannabinoid free plant with typical entourage compounds.
[0081] The second condition could also affect metabolites other than cannabinoids, as in the case of an obstruction of the basic pathways of common precursors for different classes of end products.
[0082] The IPP incorporated, via GPP, into cannabinoids is derived from the DOX pathway in the plastids [2]. Monoterpenes, diterpenes, carotenoids, phytol and tetraterpenes are also uniquely synthesised in the plastids and one could therefore conclude that the IPP incorporated in these compounds, as with cannabinoids, is derived from the DOX pathway [21].
[0083] Sesquiterpenes, sterols and triterpenes are uniquely synthesised in the cytoplasm. Presumably they are synthesised from MVA derived IPP [21] and so do not share a fundamental pathway with the terpenoid moiety of cannabinoids.
[0084] Even so, according to Evans [22], there is also evidence for a cooperative involvement of the DOX- and the MVA pathway in the synthesis of certain compounds, through the migration of IPP from the plastids into the cytoplasm and vice versa.
[0085] The potentially wider chemical effect of engineering plants with the cannabinoid knockout factor yet which express selected entourage compounds has implications for pharmaceutical cannabis breeding. Cannabinoids, and THC in particular, are generally considered as the major pharmaceutically active components of Cannabis . Nevertheless, according to McPartland and Russo [23], the terpenoid fraction may modify or enhance the physiological effects of the cannabinoids, providing greater medicinal benefits than the pure cannabinoid compounds alone. As summarized by Williamson and Whalley [24], there are indications that the non-cannabinoid ‘entourage’ of constituents, such as:
monoterpenes; sesquiterpenes; and flavonoids
modulate the cannabinoid effects and also have medicinal effects by themselves. Speroni et al. [25] reported an anti-inflammatory effect from an extract that was obtained from a cannabinoid-free chemotype.
Selection
[0089] Whilst USO-31 was selected as the source of a “knockout” gene to be introduced into pharmaceutical plants the challenge remained of achieving plants which were devoid of cannabinoids but which retained a good profile of selected entourage compounds (i.e. were broadly speaking comparable to plants grown to produce extracts for pharmaceutical use). In this regard USO-31 had a chemical profile, which was not similar to medicinal varieties in that it was lacking both in cannabinoids, and monoterpenes. Furthermore, the sesquiterpene profile also differed both quantitatively and qualitatively from that of plants used to produce pharmaceutical extracts.
EXAMPLES
Example 1
Breeding Programme
[0090] To overcome the problem of creating a reference plant which is, in the case of Cannabis sativa , free of cannabinoids BUT which had a chemical profile of entourage compounds resembling pharmaceutical cannabis , selective breeding programmes were undertaken.
[0091] A first cross was made between the selected cannabinoid free plant USO-31 and a plant having a high cannabinoid content of a given cannabinoid, in this case M35, a high THCV containing plant (83.4% by weight of cannabinoids THCV), and M84, a high CBD containing plant (92.4% by weight of cannabinoids CBD). The high cannabinoid plants were selected both for their high and specific cannabinoid contents and their vigour.
[0092] Alternatively, a direct cross with a selected pharmaceutical plant could have been made.
[0093] Table 1, bottom 2 rows, provides details of the cannabinoid composition of these parental clones:
[0000]
TABLE 1
Characteristics of parental clones used in breeding experiments with cannabinoid-free materials.
Cannabinoid
Cannabinoid composition b
Code
Generation/type
Source population
content a
CBDV
CBCV
THCV
CBD
CBC
CBGM c
THC
CBG
M3
Non-inbred clone
Skunk, marijuana strain
18
0.5
1.5
97.2
0.8
M16
Non-inbred clone
Turkish fibre landrace
12
91.5
2.6
1.3
3.8
0.8
M35
S 1 inbred clone
(California Orange ×
14
1.0
83.4
15.6
Thai), marijuana strains
M84
F 1 hybrid clone
(Afghan × Skunk) ×
15
1.0
92.4
1.0
3.7
1.9
(Afghan × Haze), hashish
and marijuana strains
a The total cannabinoid content (% w/w) of the floral dry matter assessed at maturity.
b The proportions (% w/w) of the individual cannabinoids in the total cannabinoid fraction assessed at maturity.
c Cannabigerol-monomethylether.
[0094] Of course other strains containing a high percentage of another cannabinoids e.g. THC, CBDV, CBG, CBGV, CBC, CBCV, CBN and CBNV could be used. By “high” is meant that the specific cannabinoid predominates and would typically comprise greater than 50% by weight of the total cannabinoids present, more particularly greater than 60%, through 70% and 80% to most preferably greater than 90% by weight.
[0095] The initial cross generated an F1 progeny (Table 2 rows 1 and 2) which were then self crossed to generate an F2 progeny from which plants having the desired characteristics (zero cannabinoid/good entourage compound chemotype profile) were selected for back crossing to pharmaceutical varieties.
[0096] The selected zero-cannabinoid plant, USO-31, was monoecious. i.e. it has unisexual reproductive units (flowers, conifer cones, or functionally equivalent structures) of both sexes appearing on the same plant. In order to self-fertilise USO-31 and mutually cross female plants, a partial masculinisation was chemically induced. Self-fertilisations were performed by isolating plants in paper bags throughout the generative stage. The USO-31 source plants were evaluated for their drug type habit. Inbred seeds from the best individual apparently devoid of cannabinoids and another with only cannabinoid traces were pooled.
[0000] i) Crosses of Low/Zero Cannabinoid USO-31 Offspring with M35 and M84
[0097] Twenty-four plants of the 2003.8 F 1 (table 2, row 2) were evaluated.
[0000]
TABLE 2
Pedigrees and codes of the progenies studied for chemotype segregation.
Seed parent a
Pollen parent b
F 1 code
F 2 code c
M35 (THCV)
USO-31 (low/zero)
2003.17
2003.17. 19
M84 (CBD)
USO-31 (low/zero)
2003.8
2003.8. 21
M3 (THC)
2003.8.21.76 F 3 (zero)
2005.45
2005.45. 13
M16 (CBD)
2003.8.21.76 F 3 (zero)
2005.46
2005.46. 27
M3 (THC)
2003.17.19.67 F 3 (zero)
2005.47
2005.47. 9
M16 (CBD)
2003.17.19.67 F 3 (zero)
2005.48
2005.48. 7
a Of the parents with cannabinoids present, the major one is indicated in brackets.
b The USO-31 pollinators were two plants with very low cannabinoid content and/or true cannabinoid absence. The other pollinators were F 3 lines confirmed to be devoid of cannabinoids.
c The underlined ciphers in the F 2 codes indicate the single F 1 individual that was self-fertilised to produce the F 2 generation. The majority of the plants had ‘normal’ cannabinoid contents, falling within a Gaussian distribution range from 1.13 to 4.56%. Three plants had only trace amounts of cannabinoids, ranging from approximately 0.02 up to 0.15%.
[0098] Similarly, the 19 plants of the 2003.17 F 1 comprised a majority of individuals with a cannabinoid content in the range of from 1.69 to 13.76%, and two plants with cannabinoid traces of only ca. 0.02%.
[0099] From both F 1 s, an individual with only trace cannabinoid amounts was self-fertilised to produce an inbred F 2 2003.8.21 and 2003.17.19. Both F 2 s comprised plants that were confirmed to be devoid of cannabinoids.
[0100] The remaining plants, those with cannabinoids present, could be assigned to two categories on the basis of a discontinuity in the cannabinoid content range:
a group with low contents ranging from trace amounts up to roughly 0.6%; and a group with higher contents.
[0103] The newly obtained cannabinoid-free plants designated 2003.8.21 and 2003.17.19 F 2 had more branching (typical of a drug type phenotype and in contrast to that of a fibre type phenotype), a stronger fragrance (due to the presence/increase in the terpenes and sesquiterpenes) and higher trichome density (determinable on examination) than the original USO-31 plants.
[0104] The cannabinoid-free F 2 individuals with the best drug type plant habit, 2003.8.21.76 and 2003.17.19.67, were self-fertilised to produce fixed cannabinoid-free F 3 inbred lines (Table 2, rows 3-6, col 2) for use in a backcrossing programme with pharmaceutical production clones M3 (High THC 97.2%) and M16 (High CBD 91.5%) (Table 1, top 2 rows).
[0105] Backcrosses were performed in order to obtain cannabinoid-free material, more closely resembling (both qualitatively and quantitatively) the pharmaceutical production clones by way of their non-cannabinoid profile, particularly those of the entourage compounds.
[0106] All the Clones Listed in Table 1 were True Breeding for their Chemotype.
ii) Backcrossing of Cannabinoid-Free Lines to Pharmaceutical Production Clones M3 and M16
[0107] The cannabinoid-free lines 2003.8.21.76 and 2003.17.19.67, (Table 2, column 2, last 4 rows) were then back crossed with pharmaceutical production clones M3 and M16 and the resulting F1's crossed to generate an F2 progeny.
[0108] The resulting progeny had their cannabinoid content evaluated as shown in Table 3 below.
[0000]
TABLE 3
Total cannabinoid contents of F 1 progenies
resulting from crosses between two cannabinoid-free
inbred lines (P1) and two high content clones (P2).
Total cannabinoid content (% w/w)
F 1
F 1
No. of F 1
individual
individual
F 1
plants
self-
F 1 range
self-
progeny
evaluated
fertilised
P1
P2
Min-avg-max
fertilised
2005.45
57
2005.45.13
0
18
0.22-0.58-1.09
0.89
2005.46
57
2005.46.27
0
12
0.16-0.46-1.00
0.47
2005.47
57
2005.47.9
0
18
0.24-0.45-0.75
0.36
2005.48
57
2005.48.7
0
12
0.10-0.42-1.25
0.83
[0109] Within the F 1 s the cannabinoid contents showed a single Gaussian distribution. The F 1 contents were much lower than the parental means and therefore much closer to the cannabinoid-free parent than to the production parent. The F 1 s were well covered with trichomes and were quite fragrant.
[0110] In respect of the cannabinoid composition, the 2005.45 F 1 segregated into two chemotypes: THC predominant plants and mixed CBD/THC plants, in a 1:1 ratio.
[0111] The 2005.46 F 1 had a uniform CBD chemotype.
[0112] The 2005.47 F 1 was uniform and consisted of THC plants, all with a minor proportion of THCV.
[0113] The 2005.48 F 1 was uniform and consisted of CBD/THC plants that also had minor proportions of CBDV and THCV.
[0114] Per F 1 , one individual was selected on the basis of criteria such as ‘drug type morphology’ (e.g. branching) and minimal monoeciousness to produce back cross generations. These individuals were used for a repeated pollination of M3 or M16, which is not discussed here.
[0115] To examine chemotype segregation, the selected F 1 individuals were also self-fertilised to produce large inbred F 2 s.
[0116] FIG. 1 shows chromatograms of different chemotype segregants from the 2005.45.13 F 2 . FIG. 1 a is the chromatogram for a zero cannabinoid plant.
[0117] The different chemotype segregants were microscopically compared. The cannabinoid-free plants of each progeny all had small, grey, dull trichomes of various shapes ( FIG. 2 a ). Some were headless; some were pinhead and shrivelled, either flat, convex or concave.
[0118] By way of contrast:
[0119] The high content CBD- and/or THC-predominant individuals of each group all had big, round clear heads that sparkled under the lamp ( FIG. 2 b );
[0120] The low content plants from each progeny were almost indistinguishable from the cannabinoid-free plants except that there was an occasional small but bright trichome in some ( FIG. 2 c ); and
[0121] The high content CBG predominant plants from the 2005.45.13 F 2 had big, round, opaque white heads ( FIG. 2 d ), clearly distinct from the transparent ones occurring on the THC predominant plants of the same progeny.
[0122] The low content CBG predominant 2005.45.13 plants did not show opaque white trichome heads and were indistinguishable from the low content THC predominant plants. Neither were white trichome heads observed in any of the cannabinoid-free plants of this progeny.
[0123] As an indication of their vigour, the total above ground dry weights of all the cannabinoid-free- and the high content segregants were assessed. Per progeny, per segregant group the weights showed a Gaussian distribution.
[0124] For the 2005.45.13, 2005.46.27 and the 2005.47.9 progenies the cannabinoid-free individuals on average had a ca. 10% higher dry weight than the high content individuals.
[0125] In the 2005.48.7 progeny however, the average weight of the high content group exceeded that of the cannabinoid-free group by about 10%.
[0126] In order to characterize the plants a chemical analysis of both the cannabinoid content, and selected other chemicals, was undertaken as set out below:
Example 2
i) Analysis of Cannabinoid Content and Other Chemicals
[0127] Mature floral clusters were sampled from every individual plant considered in the breeding experiments. Sample extraction and GC analysis took place as described by de Meijer et al. [26].
[0128] The identities of the detected compounds were confirmed by GC-MS. Cannabinoid peak areas were converted into dry weight concentrations using a linear calibration equation obtained with a CBD standard range. The contents of the individual cannabinoids were expressed as weight percentages of the dry sample tissue. The total cannabinoid content was calculated and the weight proportions of the individual cannabinoids in the cannabinoid fraction were used to characterize the cannabinoid composition.
ii) Chemical Comparison of Bulk Segregants
[0129] Each of the six F 2 s listed in Table 2 segregated into:
cannabinoid-free plants; plants with cannabinoid traces; and plants with high cannabinoid contents.
[0133] In each case, per F 2 , the floral leaves, bracts and bracteoles of all the cannabinoid-free plants were pooled and homogenised, as was the floral fraction of all the plants belonging to the group with high cannabinoid contents. The different bulks from the:
2005.45.13 (from M3-THC), 2005.46.27 (from M16-CBD), 2005.47.9 (from M3-THC) and 2005.48.7 (from M16-CBD) F 2
were steam-distilled and the essential oil yields were assessed.
[0138] The monoterpene and sesquiterpene composition of these essential oils was analysed by Gas Chromatography with Flame Ionisation Detection (GC-FID).
[0139] The relative amounts of a wide range of entourage compounds in the bulk homogenates of:
2003.8.21 (from M84-CBD) and 2003.17.19 (from M35 THCV) F 2 s
were also compared by using the following analytical techniques:
a) Gas Chromatography—Mass Spectrometry (GC-MS)
[0142] To obtain comparative fingerprints, GC-MS analyses were performed on a HP5890 gas chromatograph, coupled to a VG Trio mass spectrometer. The GC was fitted with a Zebron fused silica capillary column (30 m×0.32 mm inner diameter) coated with ZB-5 at a film thickness of 0.25 μm (Phenomenex). The oven temperature was programmed from 70° C. to 305° C. at a rate of 5° C./min. Helium was used as the carrier gas at a pressure of 55 kPa. The injection split ratio was 5:1.
[0000] b) Gas Chromatography with Flame Ionisation Detection (GC-FID)
[0143] GC profiles of terpenoids were generated in the splitless mode with a HP5890 gas chromatograph. The GC was fitted with a Zebron fused silica capillary column (30 m×0.32 mm inner diameter) coated with ZB-624 at a film thickness of 0.25 μm (Phenomenex). The oven temperature was held at 40° C. for 5 minutes, programmed to 250° C. at a rate of 10° C./min then held at 250° C. for 40 minutes. Helium was used as the carrier gas at a pressure of 9.2 psi. The injection split ratio was 10:1.
[0000] c) High-Performance Liquid Chromatography (HPLC) with Ultra-Violet (UV) Detection
[0144] HPLC profiles were obtained using methods specific to a variety of compound classes. All samples were analysed using Agilent 1100 series HPLC systems
[0000] (i) Cannabinoid profiles were generated using a C 18 (150×4.6 mm, 5 μm) analytical column. The mobile phase consisted of acetonitrile, 0.25% w/v acetic acid and methanol at a flow rate of 1.0 ml/min and UV profiles were recorded at 220 nm.
(ii) Carotenoid profiles were generated using a Varian Polaris C 18 (250×4.6 mm, 5 μm) analytical column. The mobile phase consisted of acetonitrile:methanol:dichloromethane: water at a flow rate of 1.2 ml/min and UV profiles were recorded at 453 nm.
(iii) Chlorophyll profiles were generated using the same column, mobile phase and flow rate described for carotenoids. UV profiles were recorded at 660 nm.
(iv) Non-polar compound profiles (triglycerides, sterols etc) were generated by a gradient LC method using a Phenomenex Luna C 18 (2) (150×2.0 mm, 5 μm) analytical column. The mobile phase consisted of solvent A (acetonitrile:Methyl-tert-butyl-ether (9:1)) and solvent B (water) with the proportion of B decreased linearly from 13% to 0% over 30 minutes then held constant for 20 minutes at a flow rate of 1.0 ml/min. The flow rate was then increased linearly to 1.5 ml/min over 40 minutes and UV profiles were recorded at 215 nm.
[0145] (v) Polar compound profiles (phenolics) were generated by a gradient LC method using an Ace C 18 (150×4.6 mm, 5 μm) analytical column. The mobile phase consisted of solvent A (acetonitrile:methanol, 95:5) and solvent B (0.25% w/v acetic acid:methanol, 95:5). The proportion of B was decreased linearly from 75% to 15% over 30 minutes then held constant for 10 minutes at a flow rate of 1.0 ml/min and UV profiles were recorded at 285 nm.
Results
Chemical Comparison of Cannabinoid-Free- and High Content Bulks
[0146] The yields and compositions of steam-distilled essential oils from bulked cannabinoid-free- and bulked high content segregants of the four F 2 progenies are presented in Table 4 below.
[0000]
C
H
I
Parent
D
F
G
Back cross
Back cross
USO-31
Parent
E
Intermediate
Intermediate
parent
parent
Zero
M35
Parent
USO-31 ×
USO-31 ×
M16
M3 97.2%
A
cannabinoid
83.4%
M84
M35 F2
M84 F2
91.5% CBD
THC
R/T
B
Control 1
THCV
92.4% CBD
Table 5
Table 5
Control 2
Control 3
Weight of material (g)
73.8 g
117.7 g
120.5 g
Volume of oil (ml)
0.10 ml
0.3
0.95
% OIL (% v/w)
0.14%
0.25
0.79
MONOTERPENES
10.3
alpha-pinene
UDL
7.3
4.95
11.8
beta-pinene
UDL
2.65
3.58
12.2
myrcene
UDL
42.55
39.02
13.7
limonene
UDL
5.27
6.66
14.2
beta-ocimene
UDL
2.5
UDL
16
Linalol
UDL
3.68
4.65
17.8
cis-verbenol
UDL
UDL
UDL
18
trans-verbenol
UDL
UDL
TOTAL
0
63.95
58.86
SESQUITERPENES
28.8
caryophyllene
33.02
25.11
16.44
trans alpha
28.9
bergamotene
5.75
UDL
2.45
29.2
(z)-beta farnesene
9.34
UDL
4.25
29.8
humulene
11.96
8.71
7.65
30.7
Unidentified
5.95
30.8
(e)-beta farnesene
1.59
2.23
UDL
31.1
gamma gurjunene
4.01
UDL
UDL
31.3
delta guaiene
UDL
UDL
31.6
Unidentified
1.03
32.3
(e)-nerolidol
0.98
UDL
5.31
32.7
unknown
UDL
5.03
33.6
Unidentified
1.91
33.8
caryophyllene oxide
6.42
UDL
UDL
34.5
humulene epoxide II
3.17
UDL
UDL
36.4
alpha bisabolol
UDL
UDL
47.5
Unidentified
7.48
TOTAL
92.61
36.05
41.13
J
L
N
P
Final zero
Final zero
Final zero
Final zero
2005.45.13
K
2005.46.27
M
2005.47.9
O
2005.48.7
Q
A
M3 backcross
2005.45.13
M16 backcross
2005.46.27
M3 backcross
2005.47.9
M16 backcross
2005.48.7
R/T
B
zero
high
zero
high
zero
high
zero
high
Weight of material
104.5 g
88.1 g
95.1
92.2
87.1
86.4
85.2
123.6
(g)
Volume of oil (ml)
0.68
0.5
0.64
0.8
0.24
0.74
0.35
0.78
% OIL (% v/w)
0.65
0.57
0.67
0.87
0.28
0.87
0.41
0.63
MONOTERPENES
10.3
alpha-pinene
16.64
11.83
28.53
26.8
10.27
2.86
33.52
22.53
11.8
beta-pinene
7.65
6.58
12.6
9.37
5.57
2.22
15.51
8.98
12.2
myrcene
51.1
42.11
34.16
42.86
19.84
41.45
24.82
36.47
13.7
limonene
4.76
4.53
6.41
7.41
7.27
5.54
5.17
4.58
14.2
beta-ocimene
UDL
UDL
UDL
UDL
UDL
9.58
UDL
8.6
16
Linalol
1.62
2.78
UDL
UDL
10.48
2.95
2.91
UDL
17.8
cis-verbenol
UDL
UDL
UDL
UDL
UDL
UDL
1.73
UDL
18
trans-verbenol
UDL
UDL
UDL
UDL
3.31
UDL
2.61
UDL
TOTAL
81.77
67.83
81.7
86.44
56.74
64.6
86.27
81.16
SESQUITERPENES
28.8
caryophyllene
3.9
12.25
7.28
8.35
7.97
15.93
4.73
9.84
trans alpha
28.9
bergamotene
3.86
3.71
1.71
UDL
UDL
UDL
UDL
UDL
29.2
(z)-beta farnesene
4.83
6.05
2.78
1.95
UDL
3.48
UDL
1.86
29.8
humulene
3.04
6.83
3.27
3.26
7.88
7.68
2.12
3.69
30.8
(e)-beta farnesene
UDL
1.69
UDL
UDL
UDL
UDL
UDL
UDL
31.1
gamma gurjunene
UDL
UDL
UDL
UDL
UDL
1.78
UDL
UDL
31.3
delta guaiene
UDL
UDL
UDL
UDL
3.64
4.67
1.67
3.44
32.3
(e)-nerolidol
UDL
1.65
UDL
UDL
UDL
UDL
UDL
UDL
32.7
unknown
UDL
UDL
UDL
UDL
UDL
1.86
UDL
UDL
33.8
caryophyllene oxide
2.62
UDL
3.25
UDL
13.43
UDL
5.19
UDL
34.5
humulene epoxide II
UDL
UDL
UDL
UDL
6.06
UDL
UDL
UDL
36.4
alpha bisabolol
UDL
UDL
UDL
UDL
4.27
UDL
UDL
UDL
TOTAL
18.25
32.18
18.29
13.56
43.25
35.4
13.71
18.83
[0147] In three (2005.46.27, 2005.47.9, and 2005.48.7), the cannabinoid-free bulks contained less essential oil than the high content ones.
[0148] In 2005.45.13 however, the cannabinoid-free bulk was slightly richer.
[0149] No significant qualitative differences in the essential oil composition were found, only minor quantitative ones, which generally did not show a systematic pattern.
[0150] The only consistent quantitative difference between the low and high content progeny was difference was found for caryophyllene oxide that in all four progenies, reached a higher proportion in the cannabinoid-free bulks than in the high content bulks.
[0151] When the zero cannabinoid backcross plants of the invention were compared to control 1 (the original zero cannabinoid plant which was also devoid of monoterpenes) and controls 2 and 3 (the pharmaceutical plants with a high cannabinoid content and a range of entourage compounds) the following differences were observed:
1. The volume of oil (%) obtained by steam distillation in the zero cannabinoid plants of the invention was on average 0.50%. By way of comparison control 1 is 0.14%, and the mean of control 2 and 3 was 0.52%. In other words the % oil is representative of the pharmaceutical clones. 2. The total measured monoterpene fraction in the zero cannabinoid plants of the invention was on average about 76. By way of comparison control 1 is 0, and the mean of control 2 and 3 was about 61. In other words the monoterpene fraction is representative of the pharmaceutical clones. 3. Within the monoterpence fraction in the zero cannabinoid plants of the invention the predominant terpene was myrcene, followed by alpha pinine and beta pinine with smaller amounts of limonine and linalol. Whilst quantitatively there were differences compared to the pharmaceutical controls there was, broadly speaking, a qualitative relationship. 4. The total measured sesquiterpene fraction in the zero cannabinoid plants of the invention was on average about 23. By way of comparison, control 1 is about 93, and the mean of controls 2 and 3 was about 39. In other words the sesquiterpene fraction is much more representative of the pharmaceutical clones than control 1. 5. Within the sesquiterpene fraction in the zero cannabinoid plants of the invention the predominant sesquiterpene were carophyllene, humulene and carophyllene oxide (accounting for more than 50% of the sesquiterpence fraction). Whilst there were differences compared to the pharmaceutical controls (where quantitatively carophyllene and humulene were again the most significant sesquiterpenes but carophyllene oxide was absent) there was, broadly speaking a qualitative, if not quantitative relationship between the plants of the invention and the pharmaceutical plants as compared to the starting zero cannabinoid plants which had much higher levels of sesquiterpenes and a wider detectable range of sesquiterpenes.
[0157] By way of comparison Table 5 gives some analytical data on the intermediate plants generated. It is a comparison of the different segregant bulks from 2003.8.21 and 2003.17.19 for a variety of compound classes.
[0000]
TABLE 5
The composition of bulked cannabinoid-free-(Zero) and bulked high
content segregants of two intermediate F 2 progenies.
F 2 progenies
2003.8.21
2003.17.19
Segregant bulks
Zero
High
Zero
High
(i) Cannabinoids c
CBDV
—
0.00566
—
—
THCV
—
—
—
0.08814
CBGV
—
—
—
0.01157
CBD
—
0.47868
—
—
CBC
—
0.04855
—
0.02771
CBGM
—
0.00671
—
—
THC
—
0.01605
—
0.32459
CBG
—
0.20785
—
0.05573
CBN
—
—
—
0.01179
Triterpenes b
Squalene
4.1 × 10 7
7.9 × 10 7
2.1 × 10 7
1.9 × 10 7
Unidentified hydrocarbon
5.2 × 10 8
5.4 × 10 8
1.1 × 10 8
1.6 × 10 8
Unidentified alcohol 1
3.8 × 10 8
5.1 × 10 8
1.1 × 10 8
3.3 × 10 8
Unidentified alcohol 2
1.3 × 10 8
1.3 × 10 8
5.5 × 10 7
1.4 × 10 8
Diterpenes c
Phytol
0.0587
0.0591
0.0511
0.0487
Sesquiterpenes c
Beta-caryophyllene
0.0043
0.0105
0.0022
0.0102
Alpha-caryophyllene
0.0022
0.0037
0.0027
0.0035
Caryophyllene oxide
0.0049
0.0041
0.0020
0.0041
Nerolidol
0.0030
0.0024
0.0043
0.0027
Monoterpenes c
Alpha-pinene
0.0010
0.0015
0.0015
0.0085
Myrcene
0.0017
0.0057
0.0024
0.0180
Limonene
—
0.0011
—
0.0015
Linalol
0.0030
0.0053
0.0035
0.0053
Long-chain alkanes b
Nonacosane
1.1 × 10 9
9.5 × 10 8
2.0 × 10 8
4.7 × 10 8
Heptacosane
1.5 × 10 8
1.8 × 10 8
5.5 × 10 7
4.7 × 10 7
Pentacosane
2.5 × 10 7
2.0 × 10 7
1.3 × 10 7
7.4 × 10 6
Hentriacontane
2.7 × 10 8
1.6 × 10 8
4.2 × 10 7
7.3 × 10 7
Sterols b
Sitosterol
2.3 × 10 8
1.5 × 10 8
7.6 × 10 7
2.9 × 10 8
Campesterol
6.6 × 10 7
4.0 × 10 7
1.3 × 10 7
5.9 × 10 7
Stigmasterol
5.1 × 10 7
3.3 × 10 7
8.1 × 10 6
4.6 × 10 7
Fatty acids a
Palmitic acid
✓
✓
✓
✓
Linoleic acid
✓
✓
✓
✓
Oleic acid
✓
✓
✓
✓
Stearic acid
✓
✓
✓
✓
Linolenic acid
✓
✓
✓
✓
Aldehydes b
Octadecanal
2.4 × 10 7
5.5 × 10 7
8.1 × 10 7
6.9 × 10 7
Vitamins b
Vitamin E
1.6 × 10 7
2.1 × 10 7
1.2 × 10 7
1.3 × 10 7
(ii) Carotenoids a
Beta-carotene
✓
✓
✓
✓
(iii) Chlorophylls a
Chlorophyll a
✓
✓
✓
✓
Triglycerides d
GGL
49.13
22.67
39.07
32.81
GLL
19.40
7.00
9.71
7.03
OLLn
39.37
22.87
48.23
39.36
OLL
20.14
6.21
15.53
10.80
a compounds scored as present (✓) or absent (—).
b quantities expressed as GC-MS peak areas.
c quantities expressed as w/w contents.
d quantities expressed as HPLC-UV peak areas.
[0158] In general the differences between the entourages of the cannabinoid-free and the high content bulks were only quantitative. Limonene was an exception, as it was not detected in the cannabinoid-free bulks whereas a minor presence was found in both of the high content bulks.
[0159] However, the essential oil data in Table 4 does not confirm this finding for the other F 2 s. Likewise, Table 5 does not show the difference in caryophyllene oxide as it appears in Table 4.
[0160] Both progenies in Table 5 had consistently higher levels of four different triglycerides in the cannabinoid-free bulks than the high content bulks. The occurrence of none of the entourage compounds listed in the Tables 4 and 5 appears to be critically associated with the presence or absence of cannabinoids.
[0161] With the reported exception of the triglycerides, the quantitative differences in the entourage compounds does not show a consistent trend between cannabinoid-free- and high content bulks.
[0162] This is most clearly seen in FIG. 3 , which compares high cannabinoid bulks with cannabinoid free bulks. It also shows an M3 pharmaceutical bulk. What is apparent from a comparison of these extracts is that the profiles between the high content bulk and the cannabinoid free bulk of the segregating plants are very similar and that further more there is substantial similarity to the pharmaceutical extract M3, particularly at the earlier retention times (less than 30 minutes).
Discussion
[0163] The cannabinoid-free segregants resulting from backcrosses with high content drug clones had glandular trichomes in normal densities but the trichome heads were dull and much smaller than those of high cannabinoid content sister plants. Nevertheless the trichomes of cannabinoid-free segregants appear to be functional metabolic organs, as the chemical comparison of contrasting segregant bulks did not reveal big differences in the content and composition of volatile terpenes, which are also produced in the trichomes. The absence of cannabinoids probably causes the small trichome heads, rather than being a result of them.
[0164] The abundant presence of apparently functional trichomes on the cannabinoid-free plants rules out that the absence of cannabinoids is due to a disrupted morphogenesis of the glandular trichomes. It thus appears that the cannabinoid knockout factor is not derived from the gland free plants selected by Gorshkova et al [16].
[0165] It is more plausible that the absence of cannabinoids is attributable to the blockage of one or more biochemical pathways that are crucial for the formation of precursors upstream of CBG. As the chemical entourage of cannabinoid-free plants is intact, the obstacle is probably not in the MVA and DOX pathways towards IPP.
[0166] A blocked MVA pathway would not affect cannabinoid synthesis [2], but it should reduce levels of sesquiterpenes, sterols and triterpenes [21].
[0167] A blockage of the DOX pathway would obstruct the synthesis of the terpenoid moiety of cannabinoids [2] but it should also negatively affect the synthesis of monoterpenes, diterpenes, carotenoids, phytol and tetraterpenes [21].
[0168] An alternative is that the knockout allele encodes a defective form of the enzyme GOT [1] that catalyses the condensation of resorcinolic acids (OA and DA) with GPP into CBG. However, with such a mechanism one would expect an accumulation of the phenolic moieties OA and/or DA in the cannabinoid-free segregants. Our GC method for cannabinoid analysis detects the decarboxylated forms of both acids but they were observed in none of the cannabinoid-free plants' chromatograms.
[0169] The most plausible hypothesis for the absence of cannabinoids appears to be a blockage in the polyketide pathway towards the phenolic moieties OA and DA. Whatever the working mechanism of the cannabinoid knockout factor is, one would expect that a functional synthase dominates a non-functional version, and so it remains obscure as to why the heterozygous genotypes (O/o) have such a strongly suppressed cannabinoid synthesis.
[0170] The essential oil comparison and the chromatographic fingerprinting of contrasting segregant bulks demonstrated that except the cannabinoids, all the monitored compound classes were present in both segregant groups. The relative levels of the compound classes did vary between the contrasting segregant groups but not usually in a systematic way.
[0171] The quantitative differences between contrasting bulks could be attributable to the fact that in cannabinoid-free plants the trichome heads, as the metabolic centres for a range of end products, are not inflated with cannabinoids. This may change the physical environment in which the reactions occur so that it quantitatively affects the synthesis of entourage compounds. The fact that large amounts of basic cannabinoid precursors are not incorporated may also affect equilibriums of other biosynthetic reactions.
[0172] A further benefit of the plants of the present invention is that they can be used to create plant extracts containing cannabinoids in quantities/purities, which could not be achieved naturally. Such plant extracts providing the benefits arising from the presence of one or more selected entourage compounds. The cannabinoids, which could be introduced to the cannabinoid free extracts, could include one or more natural cannabinoids, synthetic cannabinoids or biosynthetic cannabinoids (modified natural cannabinoids). This would produce a “designer” plant extract that could be used in clinical trials or as medicines.
[0173] The benefits of natural or biosynthetic cannabinoids over synthetic cannabinoids lies in the fact that all of the cannabinoids are in the active form as opposed to a racemic mixture.
[0174] Other aspects of the invention will be clear to the skilled artisan and need not be repeated here. Each reference cited herein is incorporated by reference in its entirety for the relevant teaching contained therein.
[0175] The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, it being recognized that various modifications are possible within the scope of the invention.
REFERENCES
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[4] Taura F, Morimoto S, Shoyama Y, Mechoulam R (1995) First direct evidence for the mechanism of delta-1-tetrahydrocannabinolic acid biosynthesis. J Am Chem Soc 38: 9766-9767
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[8] Morimoto S, Komatsu K, Taura F, Shoyama Y (1998) Purification and characterization of cannabichromenic acid synthase from Cannabis sativa . Phytochemistry 49:1525-1529
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[11] Raharjo T J, Chang W T, Choi Y H, Peltenburg-Looman A M G, Verpoorte R (2004b) Olivetol as a product of a polyketide synthase in Cannabis sativa L. Plant Science 166:381-385
[12] Samuelsson G (1999) Drugs of natural origin, 4 th edition. Swedisch Pharmaceutical Press, Stockholm 551 pp
[13] Meijer E P M de (1995) Fibre hemp cultivars:a survey of origin, ancestry, availability and brief agronomic characteristics. J Int Hemp Association 2:66-73
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[15] Virovets V G, Scherban I, Orlov N (1997) Selektion auf niedrige Gehalt der Cannabinoid und hohe Produktivität im Schaffingsprogramm von Hanfsorten ( Cannabis sativa L.), die keine narkotische Ativität besitzen. Proceedings of the symposium Bioresource Hemp 97, Frankfurt am Main, Germany. P 135-153
[16] Gorshkova L M, Senchenko G I, Virovets V G (1988) Method of evaluating hemp plants for content of cannabinoid compounds [Russian]. Referativnyi Zhurnal 12.65.322.
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[19] Pacifico D, Miselli F, Micheler M, Carboni A, Ranalli P, Mandolino G (2006) Genetics and marker-assisted selection of the chemotype in Cannabis sativa L. Molecular Breeding 17:257-268
[20] Sirikantaramas S, Taura F, Tanaka Y, Ishikawa Y, Morimoto S, Shoyama Y (2005) Tetrahydrocannabinolic acid synthase, the enzyme controlling marijuana psychoactivity, is secreted into the storage cavity of the glandular trichomes. Plant Cell Physiol 46:1578-1582
[21] Samuelsson G (1999) Drugs of natural origin, 4 th edition. Swedisch Pharmaceutical Press, Stockholm 551 pp.
[22] Evans W C (2002) Pharmacognosy 15 th edition. Saunders, Edinburgh, 585 pp.
[23] McPartland J M, Russo E B (2001) Cannabis and Cannabis extracts:greater than the sum of their parts? J. Cannabis Therapeutics 1:103-132.
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[25] Speroni E, Govoni P, Grassi G, Utan A (2003) Antiinflammatory effects of Cannabis sativa L. extracts containing nonpsychoactive cannabinoids. In:Borrelli F, Capasso F, Milic N, Russo A (eds) Proceedings 3rd International Symposium on Natural Drugs, Indena, Naples, pp 107-114.
[26] Meijer E P M de, Hammond K M (2005) The inheritance of chemical phenotype in Cannabis sativa L. (II):cannabigerol predominant plants. Euphytica 145:189-198. | The invention relates to a reference plant which has been selected to:
a) not express a medicinally active compound or group of compounds; yet b) express, at least substantially qualitatively, most other non medicinally active compounds present in a therapeutically active comparator plant.
The reference plant can be used to generate a reference extract with a reference chemical profile which resembles that of the comparator plant less the active compound or group of compounds and may thus be used as a placebo or to otherwise test the hypothesis that the active compound or compounds are responsible for an extracts perceived medicinal activity. | 0 |
This is a continuation of application No. 07/582,036 filed Sep. 13,1990, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to countermeasures against an abnormal stop of an industrial robot apparatus for loading workpieces on a pallet.
An industrial robot apparatus with a fail safe means against an abnormal state such as an earthquake has been known as disclosed in Japanese Patent Laid Open Publication No. SHO 61-88301.
This industrial robot apparatus is structured so that an industrial robot is stopped when an abnormality occurs.
When the aforementioned conventional industrial robot apparatus for loading workpieces is abnormally stopped and then restarted, the program step in which the abnormality occurs is not always in accord with the actual operation stop situation. Thus, when the industrial robot apparatus is restarted, the workpieces are excessively or insufficiently loaded.
SUMMARY OF THE INVENTION
An object of the present invention is to solve such a problem and to provide an industrial robot apparatus where no loading failure takes place when it is restarted after an abnormal stop.
An industrial robot apparatus according to the present invention comprises a control unit for controlling an industrial robot and peripheral unit thereof by using a program so as to load workpieces on a pallet, abnormal stop means for detecting an abnormality which occurs in at least either of the industrial robot and the peripheral unit and for stopping both the industrial robot and the peripheral unit, storage means for storing a step of the program which is being executed when the abnormal stop takes place, and removal means for removing remaining workpieces to be loaded on a pallet in steps following the stored step of the storage means.
In accordance with the present invention, the industrial robot apparatus stores the program step in which the abnormal stop means operates, and removes remaining workpieces which are being loaded to a pallet in the step following the stored step by the removal means. Thus, after the industrial robot apparatus is restored from the abnormality and it is restarted, it is possible to prevent the workpieces from being improperly loaded to the pallet, thereby improving the reliability of the operations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a conceptual plan view of an industrial robot apparatus in accordance with the present invention;
FIG. 2 is a right side view of FIG. 1;
FIG. 3 is a conceptual electric diagram showing electric connections of the inventive industrial robot apparatus shown in FIG. 1;
FIG. 4 is an outlined flow chart describing the operations of the inventive industrial robot apparatus shown in FIG. 1; and
FIG. 5 is a schematic showing another embodiment of an industrial robot apparatus in accordance with the present invention, the schematic according with FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 4 are schematics showing an embodiment of the present invention. Reference numerals 1 to 5 designate receiving units, each of which is a conveyer for carrying particular workpieces different from others, respectively. The reference numeral 1 is a first receiving unit; 2 is a second receiving unit; 3 is a third receiving unit; 4 is a fourth receiving unit; and 5 is a fifth receiving unit, respectively. Reference numeral 6 is a supply conveyer disposed perpendicular to each end of the first receiving unit 1 to the fifth receiving unit 5, the supply conveyer 6 having a stopper 6a at one end.
Reference numerals 7 to 11 are blocking mechanisms disposed at one end of each of the first receiving unit 1 to the fifth receiving unit 5, respectively. Reference numerals 12 to 16 are counting units which are provided corresponding to the first receiving unit 1 to the fifth receiving unit 5, respectively, the optical path of each counting unit being traversed by the supply conveyer 6. Reference numeral 17 is a peripheral unit which is a supply unit comprising the supply conveyer 6, the blocking mechanisms 7 to 11, the counting units 12 to 16, and a control means 18. Reference numeral 19 is an industrial robot disposed at the end of the supply conveyer 6, the industrial robot 19 having a hand 19a.
Reference numeral 20 is a control means for the industrial robot 19. Reference numeral 21 is a pallet disposed at a particular position close to the industrial robot 19. Reference numeral 21' is a pallet on which workpieces are being loaded, the pallet being removed. Reference numeral 22 is a removal means including a removal program executed when an abnormal stop takes place, the removal means being provided with a removal extruding or extracting unit 22a and a removal conveyer 22b, which are disposed at the end of the supply conveyer 6. Reference numeral 23 is a control unit including a program for supplying workpieces and for loading them on a pallet, the control unit 23 being a computer comprising an I/0 port 23a, a RAM 23b, a CPU 23c, and a ROM 23d. Reference numeral 24 is an abnormal stop means for detecting abnormalities of the peripheral unit 17 and the industrial robot 19 and for executing abnormal stops for them. Reference numeral 24a is a vision sensor of the abnormal stop means 24, the vision sensor 24a downwardly monitoring the pallet 21 on which workpieces are being loaded. Reference numeral 25 is a storage means for storing a program step in which an abnormal stop takes place. Reference numeral 26 is an alarm means for informing the operator of the occurrence of the abnormal stop.
In the aforementioned industrial robot apparatus, the peripheral unit 17 and the industrial robot 19 are operated through the control unit 23 according to a load command. Workpieces whose type and quantity are commanded are supplied by the peripheral unit 17 and loaded on the pallet 21 by the industrial robot 19 in the programmed conditions. The pallet 21 where the workpieces have been loaded is sent to a shipment place or the like.
Referring to the flow chart of FIG. 4, a process in the case that the loading operation is stopped due to a power failure or that a workpiece drops from the hand 19a will be describe in the following.
When an abnormality takes place, the abnormal stop means 24 operates and thereby the peripheral unit 17 and the industrial robot 19 are abnormally stopped in the step 101. After that, the alarm means 26 is activated and an abnormal alarm is issued in the step 102. Subsequently, the storage means 25 stores the program step in which the abnormal stop takes place in the step 103. Then, the removal means 22 operates in the step 104. In the step 104, the remaining workpieces to be loaded in the steps following the stored step are removed by the operations of the peripheral unit 17, the removal extruding unit 22a and the removal conveyer 22b according to a command from the removal program. After that, in the step 105 the remaining workpiece removal operation in the step 104 is repeated until the remaining steps of the program which are executed after the abnormal stop takes place are completed. The removed workpieces and the pallet for which the loading operation has not yet been completed are transferred after the former have been manually loaded on the latter. Alternatively, the removed workpieces are sent to the corresponding receiving units 1 to 5, respectively. Thus, after the apparatus is restored from the abnormality and restarted, the required workpieces are completely loaded on the pallet, thereby providing an industrial robot apparatus with high reliability and high efficiency.
FIG. 5 is a schematic showing another embodiment of the present invention. In the figure, the same reference numerals as FIGS. 1 to 4 represent same portions, respectively. Reference numerals 22c to 22q are units structuring part of the removal means 22. The reference numeral 22c is a first section conveyer whose end is in contact with the removal conveyer 22b and which accords with the first receiving unit 1. The numeral 22d is a second section conveyer which is disposed like the first section conveyer 22c and which accords with the second receiving unit 2. The numeral 22e is a third section conveyer which is disposed like the first section conveyer 22c and which accords with the third receiving unit 3. The numeral 22f is a fourth section conveyer which is disposed like the first section conveyer 22c and which accords with the fourth receiving unit 4. The numeral 22g is a fifth section conveyer which is disposed like the first section conveyer 22c and which accords with the fifth receiving unit 5.
The numeral 22h is a first stopper which is disposed on the removal conveyer 22b and which accords with the first section conveyer 22c. The numeral 22i is a second stopper which is disposed on the removal conveyer 22b and which accords with the second section conveyer 22d. The numeral 22j is a third stopper which is disposed on the removal conveyer 22b and which accords with the third section conveyer 22e. The numeral 22k is a fourth stopper which is disposed on the removal conveyer 22b and which accords with the fourth section conveyer 22f. The numeral 221 is a fifth stopper which is disposed on the removal conveyer 22b and which accords with the fifth section conveyer 22g. The numeral 22m is a first extruding unit which is disposed on the removal conveyer 22b and which accords with the first section conveyer 22c. The numeral 22n is a second extruding unit which is disposed on the removal conveyer 22b and which accords with the second section conveyer 22d. The numeral 22o is a third extruding unit which is disposed on the removal conveyer 22b and which accords with the third section conveyer 22e. The numeral 22p is a fourth extruding unit which is disposed on the removal conveyer 22b and which accords with the fourth section conveyer 22f. The numeral 22q is a fifth extruding unit which is disposed on the removal conveyer 22b and which accords with the fifth section conveyer 22g.
In other words, in the embodiment shown in FIG. 5, the control unit 23, the abnormal stop means 24, the storage means 25, the removal means 22, and so forth are provided. Thus, it is obvious that the same operation as the first embodiment shown in FIGS. 1 to 4 can be accomplished in the second embodiment shown in FIG. 5.
Moreover, in the embodiment shown in FIG. 5, by the operations of the first stoppers 22h to the fifth stopper 221 and the first extruding unit 22m to the fifth extruding unit 22q, the workpieces which are removed when the abnormal stop takes place are sent to the first section conveyer 22c to the fifth section conveyer 22g. After that, the workpieces which are sent to the first section conveyer 22c to the fifth section conveyer 22g are returned to the first receiving unit 1 to the fifth receiving unit 5. Consequently, the labor required when an abnormal stop takes place can be saved. | An industrial robot apparatus comprise for controlling an industrial robot and a peripheral unit thereof according to a program so as to load workpieces on a pallet, an abnormal stop unit for detecting an abnormality which occurs in at least either of the industrial robot and the peripheral unit and for stopping both the industrial robot and the peripheral unit, a storage unit for storing a step of the program which is being executed when the abnormal stop takes place, and a removal unit for removing remaining workpieces to be loaded on the pallet in steps following the stored step of the storage unit. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a simplified clasp for items of jewelry or costume jewelry produced with linked elements suited for instance to produce bracelets or necklaces.
2. The Prior Art
According to known techniques both bracelets and necklaces, or likewise any items that have a closed loop form, are fastened to the arm of whoever wears them by mechanical devices called “clasps”. These clasps basically consist of a box with a slot that holds a male member, which works together with the connecting devices in the box and makes a firm connection of the two ends of the linked item.
There are various types of clasps, but it can be said that every clasp essentially has a female member with a basically boxed construction, being rather complicated to produce, and a male member with a tongue that fits into the slot in t he female member. The production of clasps is quite intricate because it involves several stages of processing such as for example blanking, bending and soldering the boxed female member and other processes for the male member. What's more, both the female fastener and the male piece have to be soldered or somehow attached to the ends of the linked elements that they have to fasten. Besides, since various work cycles have to be carried out on the clasp, such as for instance soldering the various pieces, and since the jewelry, and especially the goldsmith sector which employs these clasps, demands a high quality finish, it is understandable that the processing of the clasps requires the commitment of specialist personnel and also considerable time to work and refine the finish of the clasp.
The main object of this invention is to dramatically eliminate work time on the clasp, proposing a simplified clasp that nevertheless achieves the same scopes of known clasps.
One of the objects of this invention is also for the proposed clasp to be a very reliable fastener, that resists well to tugs and opening whether by accident or due to acts of violence.
Another object that the invention intends to achieve is that the proposed clasp is easy to use and can even be handled by a just one hand so that the user can open and close the clasp without the help of another person, as is the case for instance with bracelets where one hand is blocked since it has to be kept still to receive the actual bracelet.
Another object that it intends to achieve is to drastically reduce the cost of the clasp and its production time.
Yet another object is to produce a clasp as effective as any made from known techniques and that actually weighs considerably less than known clasps. The reason for this second need is evident especially in clasps made of precious metals, where the lighter weight of the product is an essential condition for keeping down the cost of the item, this being an important factor for it's success on the market.
SUMMARY OF THE INVENTION
All the aforementioned objects and others that shall be better explained below are achieved by a clasp for items of jewelry having an essentially linear construction made of swivel elements linked together to produce a closed loop by connecting first and second end pieces belonging to opposite ends of the item where the clasp is characterised in that it includes a pin attached to the first end piece through a hole belonging to the second end piece, at least one end of the pin having a swelling suited to snapping into a safety clip provided with intrinsic elasticity and rotably coupled on said first or said second end piece.
One advantage of this invention is that the so-called box of the clasp, in other words the female part, has now been completely eliminated with the device invention being replaced, as will be seen below, by a spring clip that works together with the male part made, under this invention, of the swollen tip of a pin. Additional characteristics and details of the invention shall be better explained in the description of two preferred forms of execution of the invention given as a guideline but not a limitation, illustrated in the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a typical example of a linked chain suited to producing a bracelet with the clasp invention;
FIG. 2 shows the end pieces before being joined together;
FIG. 2 a shows a detail of FIG. 2;
FIG. 3 shows the end pieces joined together by the clasp invention;
FIG. 4 shows another example of a chain with linked elements that are interlocked one over another;
FIG. 5 shows the end pieces before being joined together by the clasp invention;
FIG. 5 a is an enlarged detail of part of FIG. 5;
FIG. 6 shows the end pieces now joined together by the clasp invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the above figures, a bracelet with the clasp invention can be seen in FIG. 1, indicated by 1 . FIG. 2 shows how the first end piece 2 has a pin 3 soldered to it, having a swollen tip 31 produced for instance by partially melting the tip of the pin under a flame. The second end piece of the bracelet 1 , indicated by 4 , has a hole 5 with a large enough diameter to allow the entry of swollen tip 31 and therefore also the pin 3 . The second end piece 4 also has an elastic element indicated by 6 that is a clip shaped in the form of a figure of eight and is provided with intrinsic elasticity so that the widening 61 can flex apart to receive the knob 31 and then close back over it in order to prevent the spring clip 6 and pin 3 from detaching, if not due to an intentional action of the user by a lifting movement that gives rise to the deformation.
It should be noted that the spring clip 6 in the shape shown in FIG. 2 a is already known in the jewelry sector, although it is known as a safety element used in conjunction with known clasps and is in fact also called a “safety clasp” or simply “figure of eight”, because of its shape. In effect, it is quite common that known types of clasps can easily open by themselves after extensive use. So the clasp produced as it is, according to known techniques, is sometimes aided by the addition of this “safety clasp” made of the clip 6 and by a knob soldered on the box of the traditional clasp in order to create an additional safety element.
As can be seen, with the case in question the clasp's box has been eliminated, and instead, in a new and original manner, a part of the safety clasp is used, and in other words the spring clip 6 , this time working together with a specific pin having the function of the clasp's male member.
In fact, as can be seen in FIG. 3, when the pin 3 enters the hole 5 belonging to the second end piece 4 the swollen part 31 comes out of the hole 5 so that the spring clip 6 can be clipped onto the end piece 31 and complete the intended fastening. It is already understandable how the construction of the clasp invention has been extremely simplified, since for this purpose it is quite enough to provide a pin with a swollen tip and a shaped spring clip of extremely simple construction and most certainly does not require lengthy processes and costly finishing.
The clasp invention, in the form shown in FIGS. 1 to 3 , assumes that the first and second end pieces that are fastened together overlap at least to their sides.
On the contrary, FIGS. 4 to 6 show how the clasp invention can effectively be used even for linked elements that are interlocked together like those seen in FIG. 4 . FIG. 4 shows a bracelet 70 that has elements 7 all identical, linked together and each having a female part indicated by 71 that is a cavity in the element 7 and a male part indicated by 72 that, when the elements are linked together, fits into the female part 71 .
FIG. 5 and also FIG. 5 a show a case where the pin 8 is held in the first end piece indicated by 9 that has a hole cutting crossways through the cavity 71 that can be defined as a first hole 91 and a second hole 92 coaxial with each other belonging to the first lobe 73 and the second lobe 74 defining the cavity 71 . The first hole 91 has two diameters, one larger indicated by 91 a and one smaller indicated by 91 b . The second hole 92 has the same diameter as part 91 a of hole 91 . The pin 8 has two beads at its two ends, one indicated by 81 and the other indicated by 82 . The bead 81 is sized so that it sits in hole 91 a without difficulty but its diameter is greater than hole 91 b ; in this way the pin 8 cannot come out of the first hole 91 . In fact there is an additional swelling or knob 82 on the other end of the pin 8 , and therefore the pin 8 cannot come out of the first end piece 9 . In the second end piece 10 there is a hole 721 in the male section 72 with a large enough diameter to allow the bead 81 to pass through it, so that when part 72 of the male end piece 10 fits into the cavity 71 , the pin 8 , as can be seen in FIG. 6, can pass through hole 721 and hole 92 until it juts out to connect with the spring clip 6 , now mounted on the first end piece 9 .
Since most linked elements 7 are hollow, if the pin 8 is not adequately directed it has difficulty in finding the hole 92 and pass through it. To avoid this inconvenience, the example in question has been provided with a soldered guide tube 11 as can be seen in FIGS. 5 and 6, so that the pin 8 is always guided in a vertical direction thereby passing through the hole 92 to clip onto the spring clip 6 without difficulty.
It can be seen that the clasp invention can be used even in these types of linked elements. The only difference to the first example is that in this case the pin 8 is sliding and not fixed to the first end piece.
The description given amply proves the simplicity of construction of the clasp proposed under this invention and also the simplicity of its connection with the first and second end pieces, as this merely requires a hole in the second end piece for the pin to pass through and set a spring clip on the first or second end piece, as the case requires.
Therefore, according to the invention, all the lengthy and costly constructions of the clasp's box and its male member are avoided, the actual clasp is made lighter since the pin with spring clip together weigh substantially less than any kind of traditional clasp and all the finishing processes are eliminated besides the construction of the clasps according to methods conforming to former craft. The result is that, even though the clasp invention ensures absolute reliability and safety, its manufacturing cost and weight are unequivocally lower than clasps from known crafts. | An item of jewelry having an having an essentially linear construction made of swivel elements linked together to produce a closed loop by connecting first and second end pieces belonging to opposite ends, wherein a clasp thereof includes a pin attached to the first end piece and passes through a hole belonging to the second end piece, at least one end of the pin having a swelling (enlarged end) suited to snapping into a safety clip provided with intrinsic elasticity and rotatably coupled to the first or to the second end piece. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to apparatus used in manufacturing articles from fabric, such as clothing and the like. In particular, the invention relates to an apparatus used in manufacturing pocket welts. Pocket welts are generally used in the manufacture of exterior breast pockets located on men and women's suit, sport jackets and vests. Such pockets are generally constructed by making a cut in the breast of the jacket and connecting a pocket to the inward side of the jacket fabric. A pocket welt is joined to the exterior of the breast, just below the cut and along its sides to form a top portion of the completed pocket.
2. Description of the Prior Art
Prior art methods of manufacturing pocket welts are almost entirely manual. The current preferred method requires operators to manually fold substantially rectangular pieces of fabric along the longitudinal axis thereof. Subsequent to folding the operator, using a sewing machine, stitches the ends thereof along a line substantially perpendicular to the fold line. The resultant piece is then turned inside out and pressed. The resultant product is the pocket welt.
Other materials or fabrics are commonly used in combination with the exterior fabric in order to provide "body" and stiffness to the pocket welt. Various materials have been used for this purpose.
Great care must be exercised when manufacturing pocket welts for two primary reasons. If the pocket is to have its upper edge at an angle the "substantially perpendicular" folds, previously referred to, in manufacturing the welt must be altered accordingly. The ability of the operator to accomplish this depends upon his or her experience and skill. An additional problem is presented when the fabric has a design thereon, which must be matched or mated with the design appearing on the remaining portion of the jacket. This presents a particularly difficult problem to the operator when such a design is presented in combination with a pocket which is to be inclined. Of course, the ability of the operator to handle this also depends upon the operator's skill and experience.
As might be expected, the error rate in manufacturing such pocket welts is relatively high. The rate becomes higher with the inexperience of the operator. Of course, the failure rate may be substantially decreased, although it is still high, through the use of experienced and skilled operators. However, experienced and skilled operators result in a higher rate of compensation and, accordingly, increase the resultant retail price of the garment.
Accordingly, it is the primary object of the present invention to provide a method and apparatus for automating the manufacture of pocket welts.
It is an object of the present invention to provide an apparatus which will assist an operator in automatically forming a pocket welt using precut pieces of fabric.
It is an object of the present invention to provide an apparatus which will provide guides for folding opposite ends of a piece of precut fabric thereby forming the ends of a pocket welt.
It is another object of the present invention to provide an apparatus for assisting an operator in folding a piece of fabric along a longitudinal axis thereby forming the top edge of a pocket welt.
It is another object of the present invention to provide an apparatus which will enable an operator to press a pocket welt.
It is still another object of the present invention to provide an apparatus and method which will secure a piece of fabric along its fold lines subsequent to its folding into a pocket welt.
It is a further object of the present invention to provide an apparatus which will secure a piece of precut fabric while it is being folded into a pocket welt.
SUMMARY OF THE INVENTION
In accordance with the invention, an apparatus is provided which will assist an operator in automatically manufacturing pocket welts. The operator and apparatus are provided with precut pieces of fabric which are to be formed into pocket welts. The precise shape of each piece of fabric will vary in accordance with the pocket of each particular garment which is being manufactured. The invention includes means for securing a piece of precut fabric within a template. As with the precut fabric, each template is uniquely designed for the pocket of a particular garment. While the piece of precut fabric is being secured within the template by a vacuum means, the operator folds the piece of precut fabric along the lateral boundaries of the template. Subsequent to folding, the vacuum action maintains the fold line along the lateral boundaries and within the confines of the template. In an alternate embodiment of the invention, such lateral folding is automatically accomplished.
At this point in the preferred embodiment of the invention, a piece of precut stiffening material, preferably fusing material, is placed over the partially folded piece of fabric. Fusing is fabric or material which has a heat sensitive coating on one or both sides thereof and which upon heating above a predetermined temperature will melt thereby acting as an adhesive. Fusing with the coating on both sides provides greater stiffness than single side coating. After the fusing has been properly positioned, a blade is activated which forces the combination of fabric and fusing through a longitudinal slot thereby folding the combination about the edge of the blade. After the blade has forced the fabric-fusing combination through the slot, platens compress the fabric-fusing combination after the blade has withdrawn, thereby pressing the fabric and fusing along the fold lines. This also causes the fusing to melt, thereby securing the fusing to the fabric. If appropriately placed, the fusing will also secure the fabric along the fold line. The resultant product is the pocket welt.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which like numerals refer to like parts and in which:
FIG. 1 is an elevation view of a jacket having a pocket therein.
FIG. 2 is an exploded perspective view of the pocket welt shown in FIG. 1, made in accordance with the present invention.
FIG. 2a is an exploded perspective view of a prior art pocket welt which is depicted "inside out" during a particular stage of its manufacture.
FIG. 3 is a piece of precut fabric which will become, when folded as described, the pocket welt shown in FIGS. 1 and 2.
FIG. 4 is an exploded perspective view showing the manufacture of a pocket welt.
FIG. 5 is an elevation view of the apparatus of the present invention.
FIG. 6 is a plan view taken along line 6--6 of FIG. 5.
FIG. 7 is a side view taken along line 7--7 of FIG. 5 showing a portion of the apparatus of the present invention.
FIG. 8 is a portion of the apparatus shown in FIG. 5 incorporating an additional feature.
While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that particular embodiment. On the contrary, it is intended to cover all variations, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 there is shown a jacket 2 having a pocket 4 located on the jacket breast. The jacket 2 and and exposed portion of pocket 4 have stripes 5 thereon. The pocket 4 includes a pocket body 6 inside the jacket and a welt 8 outside the jacket which are joined together along seam 9. Of course, the sides of the welt 8 are joined to the jacket along it side edges 13. Although not shown, a cut or slit is made in the outer fabric of the jacket 2. Seam 9 joins the jacket at the lower portion of the cut, the welt 8, and the forward portion of the pocket body 6. The rear portin of the pocket body 6 is joined to the jacket at the upper portion of the cut. Thus, as is well known to those experienced in the art, a conventional and well known jacket pocket is constructed.
The pocket 4 is inclined at the top thereof, as shown for purposes of styling. Of course, when this is done the stripes 5 of the pocket 4 and the jacket 2 must still be properly aligned in order for the pocket welt 8 to match the jacket. The pocket is inclined with respect to the jacket at the top edge 10 of the welt 8. As will hereafter be described, the upper edge 10 of the welt 8 is also a fold line 10 of the fabric from which the pocket welt 8 is constructed, as is better shown in FIG. 2.
The pocket welt 8 is shown in FIG. 2 disconnected from the jacket 2 and the pocket body 6. The outer exposed surface 11 is also shown in FIG. 1 so that the view may be properly oriented. As may be seen, the welt 8 is constructed from a single piece of fabric 12 which has been folded along fold line 10. As is also shown in FIG. 2, the fabric 12 has been folded inwardly from its two opposite ends along fold lines 14 and 16 which become the edges 13 of the welt 8. Of course, the fabric is folded inward toward the back surface of the fabric. In the preferred embodiment of the invention the fabric 12 is used in combination with a second material, preferably fusing, for adding "body" or stiffness to the combination. If it is used, the fabric 12 may be secured by the fusing subsequent to being folded along fold lines 14 and 16. The fusing is omitted from FIG. 2 for purposes of clarity.
The fabric 12 from which the welt 8 is constructed is shown in FIG. 3 completely unfolded. The fabric 12 has notches 17 which aid in folding and act as guides. As can be seen, the portion of fabric 12 which becomes the exterior surface or face 11 of the welt 8 is the back portion of the upper surface of the fabric 12, as shown in FIG. 2. In forming the welt 8 the fabric is first folded along fold lines 14 and 16 and then subsequently along fold line 10. The fabric 12 is shown in a particular precut shape or manner. The particular shape of the precut fabric 12 is a direct function of the pattern appearing on the jacket and pocket and, more importantly, the angle that the top portion 10 of the welt 8 will have to the jacket 2. Accordingly, the particular shape may vary widely.
A prior art pocket welt is shown in FIG. 2a. The prior art pocket welt 20 is generally constructed from a rectangular piece of fabric 22. The fabric 22 is first folded along the fold line 23 so that the outer surface of the fabric 28 is facing inwardly. The fabric is then stitched along lines 24 and 26. These seams 24 and 26 are analogous to fold lines 14 and 16 of the present invention in that they will become the sides of the pocket welt. Subsequent to the stitching of seams 24 and 26, the fabric is turned inside out to form the pocket welt 20. This results in the outer surface 28 of the fabric 22 to face outward.
As previously indicated, this prior art method of forming a pocket welt has the disadvantage of being very dependent upon the skill of the operator forming the welt. The skill level required increases when the pocket is positioned at an angle to the jacket, and when alignment of a design on the fabric from which the jacket and pocket is constructed is required. All of this requires the operator's skill in determining where and how to position fold 23 and seams 24 and 26.
The method of the present invention will now be described, making reference to FIG. 4. A piece of precut fabric 12 is placed on a template 30. The template 30 has been preformed to match the precut fabric. As with the fabric 12, the template 30 is uniquely designed for a particular pocket welt. The template 30 has slots 31, or other means, which act as guides. When placing the fabric in a precut hole 41 in the template 30 the notches 17 in the fabric 12 are aligned with the template slots 31 to properly position the fabric.
The fabric 12 is then temporarily secured to the template 30. A vacuum is used in the preferred embodiment for temporarily securing the fabric to the template. The means for providing the vacuum will subsequently be discussed. The operator then folds the fabric 12 along the sides of the templates, thereby folding the fabric along fold lines 14 and 16. The folded fabric is also secured in position by the vacuum.
Then, if desired, a stiffer or fusing material 32 may be positioned over the folded fabric 12 which is also secured by the vacuum. The fusing material is used to provide body and stiffness to the welt, and also to secure the fabric along fold lines 14 and 16. Subsequent to the proper positioning of the fusing 32, the combination of the fusing 32 and fabric 12 is folded along fold line 10. This is accomplished by blade 34 forcing the partially completed pocket welt through a slot, not shown in FIG. 4, in the vacuum plate 38 upon which the template 30 is resting. The slots 31 in the template 30 also permit the blade 34 to pass through it. Of course, the fold line 10 is formed by the bottom edge 36 of the blade 34.
Subsequent to folding along fold line 10, the pocket welt 8 is pressed, thereby securing fold line 10 and melting the optional fusing 32.
The apparatus for forming pocket welts is shown in FIGS. 5 through 7. Referring now to FIG. 5 where a front elevation view of the present invention is shown. The apparatus or machine 36 includes a work table 37 and a vacuum plate 38 upon which the template 30 is positioned and secured. The vacuum plate has holes 39 therein which are connected by means not shown to a hose 47 which leads to a vacuum source. As previously indicated, and as shown in FIGS. 6 and 7, there is a slot 40 in the vacuum plate 38. Positioned above the slot 40 is the blade 34 having a bottom edge 36. The blade 34 is adapted to slide along guides 42. The blade 34 is connected to an actuator rod 44 which forms a portion of a pneumatic actuator 46. It is to be understood that actuators of various types may be used in the present invention without departing from the spirit thereof. Electric motors, solenoids and hydraulic actuators could also be used as a substitute in the present invention for the pneumatic actuator of the present invention.
The pneumatic actuator 46 is connected to an upper frame 48 which is secured to the work table 37 by supports 50. The work table 37 is supported by legs 52 which are provided with a cross support member 54 at floor level.
A foot switch 56 is provided for controlling the vacuum line which secures the fabric to the template 30. Dual switches 58 are provided on the supports 50 for actuating the apparatus, including blade 34. The dual switches 58 are used for safety purposes on that the requirement that both switches 58 be activated insures the operator's hands are free and clear from the blade during its downward movement.
A top view of the work table along line 6--6 in FIG. 5 is shown in FIG. 6. The work table 37 and vacuum plate 38 having holes 39 therein is shown for providing the vacuum for securing the fabric 12. Slot 40 is also shown in the vacuum plate 38. The template 30 is shown properly positioned and secured by fasteners 51 over the holes 39 and slot 40. The fasteners 51 may be of any suitable type but should permit quick replacement of the templates. The template 30 has a large hole 41 removed from its interior, thereby exposing the holes 39 in the work table 37. As previously discussed, the hole 41 in the template will determine the shape of the welt 8. The lateral edges of the hole 41 determine the fold lines 14 and 16 of the fabric 12. The fabric 12 is shown positioned over the template 30 by aligning the fabric notches 17 with the template slots 31 prior to the folding thereof along fold lines 14 and 16. Of course, fold lines 14 and 16 are determined by the edges of the hole 41 in the template 30.
A side view taken along line 7--7 of FIG. 5 is shown in FIG. 7. The work table 37 is shown with the template 30 thereon. The blade 34 is shown suspended above the work table 37. The fabric 12 and fusing 32 are shown positioned over the template. Positioned below the vacuum plate 38 and connected to it are platens 60 and 62. The platens may alternately be connected to the table 37. When the blade 34 forces the fabric 12 and optional fusing 32 through the slot 40 and begins withdrawing, platen 60 moves towards platen 62 as a result of pneumatic actuator 64. Platen 62 is positioned on spring supports. Platens 60 and 62 press the fabric 12 and optional fusing 32 after the blade 34 has withdrawn. Subsequent to pressing, the platens disengage permitting the welt to fall onto chute 65.
In some cases it is desirable to use steam when pressing the fabric to form the pocket welt. Accordingly, the platen 62 includes channels 67 which end at the surface of the platen forming orifices for steam. The other end of the channels 67 are connected to steam line 66. The steam line is connected to a source of steam, and to a valve, not shown, positioned along its length. The valve is connected to the system so as to provide steam only when the platens are in the process of pressing the fabric.
It has been found desirable to provide suction to remove the steam so as to prevent undue condensation of the steam, thereby wetting the welt. The suction is provided by channels 69 which end in orifices on the surface of platen 60. The other ends of the orifices are connected to a suction source through tube 71.
Referring now to FIG. 5 where the controls for the apparatus or machine 36 are shown. A main power switch 70 is provided along with switch 72 for providing steam, if that option is preferred by the user. Thermostats 74 and 76 are provided for controlling the temperature of platens 60 and 62, respectively. A timer 78 is provided for controlling the time platens 60 and 62 are engaged. A control 80 is provided for adjusting the pressure or force at which the platens 60 and 62 engage together during pressing. Screw adjustments 82 and 84 are provided for adjusting the speed of the blade during its upward and downward motions, respectively.
In operation, a supply of precut fabric pieces 12 and optional fusing pieces 32 will be provided to an operator. The main power switch 70 and optional steam switch 72 will be actuated. The proper template will be inserted on the vacuum plate 38 and properly aligned with slot 40 and secured to the work table 37.
Air will be drawn through holes 39 in the vacuum plate 38 below the template 30, thereby creating the vacuum to secure the fabric 12 to the work table 37 and template 30. The vacuum is provided by depressing foot switch 56. The vacuum will cease when the switch extends upon foot removal. With the vacuum off, the operator will properly position the fabric 12 with respect to the template by aligning the fabric notches 17 with the template slot 31. A loose positioning tolerance is permitted as it is the template and its proper positioning on the work table 37 which primarily determine the resultant shape of the pocket welt 8. When the fabric 12 has been properly positioned with respect to the template 38, the operator using foot switch 56 turns on the vacuum, thereby securing the fabric. The operator then folds the fabric 12 along the lateral edges of the template 30, thereby folding the fabric along fold lines 14 and 16, as shown in FIG. 6. Once the fabric has been folded along line 14 and 16 the folded-over fabric is also secured by the vacuum. The operator may also, at this point, position fusing over the folded fabric, which is also held in place by the vacuum.
The operator then uses both hands to actuate the dual switches 58. This causes the apparatus 36 to proceed automatically through the following steps. The blade 34 is caused to move downwardly, causing its lower edge 36 to force the fabric 12 and fusing 32 to fold around edge 36 as it passes through the slot 40 in the work table 37. The vacuum to holes 39 is maintained until the fabric has passed through slot 40. This may be accomplished automatically or by removal of the operator's foot from switch 56. The platen 60 is moved toward the platen 62 when the blade 34 is withdrawing from its most downward position. The platens compress the fabric after the withdrawal of the blade. The optional steam is automatically provided, if desired. The heat from the platens presses in the fold lines 14, 16 and 10. The heat from the platens also causes the fusing to melt, thereby securing the fabric along fold lines 14 and 16. If a fusing with both sides thereof is coated with heat sensitive material, the fabric will have fold line 10 secured also. The blade, of course, rises to its uppermost position and stops. The platens disengage when the time set on timer 78 has expired. The steam is automatically terminated when the platens disengage. Upon disengagement of the platens the completed pocket welt falls into the chute 65 properly positioned for that purpose.
Referring now to FIG. 8, an alternate embodiment of the apparatus of the invention is shown. The vacuum plate 38 and template 30 are shown with fabric 12 positioned thereon. An arm 90 is shown for automatically folding the fabric along fold line 14. Of course, another arm, not shown in FIG. 8, is provided for folding the fabric along fold line 16, also not shown in FIG. 8. Arm 90 is pivotally connected to the machine by conventional means, not shown, so that arm 90 will pivot about point 92 so as to fold fabric 12, as is shown in phantom. In operation, the operator would position the fabric 12 as heretofore described and press both switches 58 to activate the machine. Arms 90 would then automatically fold the fabric along fold lines 14 and 16 and would then proceed as heretofore described with the downward movement of the blade 34.
In describing the present invention various details, well known to machine designers skilled in the art, have been omitted for purposes of clarity. This includes the details of the pneumatic actuators, micro switches, and circuitry which enable the process and apparatus described herein to proceed and be controlled.
Thus it is apparent that there has been provided, in accordance with the invention, an apparatus and method that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with a specific embodiment thereof, it is evident that may alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and scope of the appended claims. | An apparatus for forming pocket welts is disclosed. The upper portion of the external breast pocket of men and women's sport and suit jackets are frequently constructed by making a cut in the breast of the jacket and connecting a pocket to the inward side of the jacket fabric. A pocket welt is joined to the exterior of the breast, just below the cut and along its sides to form a top portion of the completed pocket. The pocket welt is constructed using a precut piece of fabric which is positioned by an operator on a template, which forms a portion of the apparatus. The fabric is secured by a vacuum and is folded by the operator along lines determined by the template. Subsequent to folding, a precut fusing material may be positioned by the operator over the fabric. The apparatus is then actuated by the operator causing the fabric and fusing to be folded and pressed, automatically. If fusing is used, the temperature of the platens may be set sufficiently high so as to cause the fusing to bond to the fabric. | 0 |
FIELD OF THE INVENTION
This invention relates to opto-electronic devices and, more particularly, to opto-electronic devices for optical fibre applications. More specifically, although not exclusively, this invention relates to opto-electronic devices for coupling with an optical fibre termination.
BACKGROUND OF THE INVENTION
Optical fibres are widely used in many applications, for example, optical communication, remote sensing and monitoring. The core of an optical fibre is typically very small and fragile. Therefore, optical fibres are commonly provided with termination connectors for convenient coupling with an opto-electronic device. For example, an optical fibre is terminated with a glass-ferrule for enhanced mechanical stability. The ferrule also provides additional convenience so that an optical fibre core can be more easily aligned with a signal conversion means such as a photo-detector or an optical transmitter. To take advantage of the characteristic optical fibre termination, it will be beneficial to provide opto-electronic devices which are compatible with the optical fibre terminations for more efficient coupling and uncoupling.
OBJECT OF THE INVENTION
Hence, it is an object of this invention to provide opto-electronic devices for coupling with common optical fibre terminations so as to facilitate efficient coupling and uncoupling between an optical fibre and the opto-electronic devices. At a minimum, it is an object of this invention to provide a useful choice of a packaged opto-electronic devices.
SUMMARY OF THE INVENTION
Accordingly, this invention has described an opto-electronic device comprising opto-electronic circuitry on a lead-frame and an optical guide receptacle for receiving an optical guide coupler, the opto-electronic circuitry comprises signal conversion means whereby an optical signal can be converted into an electrical signal or vice versa, the optical guide receptacle comprises means for guiding reception of an optical guide coupler whereby an optical guide coupler is optically aligned with the signal conversion means when received by said optical guide receptacle. An opto-electronic device with an optical guide receptacle mounted on a lead-frame package provides efficient and expeditious coupling.
Another advantage of a lead-frame packaged opto-electronic device for coupling with a terminated optical fibre is the production efficiency since a plurality of devices can be formed on a single metal sheet before the plurality of devices are separated from the metal sheet.
Preferably, said optical guide receptacle comprises an axially extending aperture for guiding an optical guide coupler towards said signal conversion means for optically aligned coupling axially therewith.
Preferably, said axially extending aperture is formed on a cover lid, the cover lid and the optical guide receptacle are integrally moulded, the aperture on said cover lid is aligned with said signal conversion means.
Preferably, a focusing lens is formed on the cover lid and at an axial end of said axially extending aperture.
Preferably, a plastic housing is moulded on said lead-frame, the plastic housing forms a compartment which contains the opto-electronic circuitry, the compartment is sealed by said cover lid with said signal conversion means is optically communicable with said optical guide receptacle.
Preferably, the compartment of said plastic housing is filled with an optically transparent substance and the cover lid is fixed onto said plastic housing.
Preferably, said optical guide receptacle is adapted for receiving a packaged optical guide coupler which comprises an optical fibre with a ferule, the optical guide receptacle comprise an axially extending aperture the axis of which is optically aligned with said signal conversion means, the packaged optical guide coupler and the axially extending aperture of said optical guide receptacle is adapted so that the optical fibre is aligned with said signal conversion means when received by said optical guide receptacle.
Preferably, the axis of said optical guide receptacle is orthogonal to a mounting plane of the lead-frame.
Preferably, said optical guide receptacle comprises a tubular guide for guiding a packaged optical guide coupler axially towards said signal conversion means.
Preferably, said lead-frame and said opto-electronic circuitry are contained in a moulded plastic housing, said moulded plastic housing comprises a window which exposes said signal conversion means, said optical guide receptacle comprises an axially extending aperture, the axially extending aperture meets the plastic housing at said window.
Preferably, said axially extending aperture protrudes orthogonally from said moulded plastic housing and axially away from said signal conversion means.
Preferably, said axially extending aperture has a circular cross-section.
Preferably, said optical guide receptacle comprises axially extending alignment means which are circumferentially distributed around said axially extending aperture.
Preferably, each said alignment means comprises an axially extending fin.
Preferably, said signal conversion means comprises a laser source.
Preferably, said laser source is a vertical-cavity surface emitting laser.
Preferably, said signal conversion means comprises a photo-detector.
Preferably, said opto-electronic circuitry comprises an optical receiver, an optical transmitter or an optical transceiver.
Preferably, contact leads of said lead-frame are transversal to the axially extending aperture.
Preferably, said opto-electronic circuitry comprises a laser transmitted and a monitoring photo-detector for feedback control of the laser transmitter, laser output is transmitted through said optical guide receptacle.
Preferably, the opto-electronic circuitry comprises an optical receiver, said signal conversion means comprises a photo-diode.
Preferably, a partial reflector is disposed intermediate the optical guide receptacle and the signal conversion means whereby light travelling between the optical guide receptacle and the signal conversion means is partially reflected to a signal monitoring means for circuitry control.
Preferably, the partially reflected light is for feedback control of operating conditions of the signal conversion means.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will be explained in further detail below by way of examples and with reference to the accompanying drawings, in which:
FIG. 1 shows a schematic cross-sectional view of a first preferred embodiment of an opto-electronic device of this invention,
FIG. 2 shows a partially removed schematic perspective view of a second preferred embodiment of an opto-electronic device of this invention,
FIG. 3 illustrates an opto-electronic device of FIG. 2 aligned with an optical fibre termination,
FIG. 4 shows a plurality of opto-electronic devices of the second preferred embodiment on a common lead-frame package,
FIG. 4A shows the bottom view of the device of FIG. 3 ,
FIG. 5 shows schematically a third preferred embodiment of this invention,
FIG. 6 illustrates an exemplary application of an opto-electronic device of FIG. 1 when coupled with a terminated optical fibre,
FIG. 7 illustrates the termination of the optical fibre of FIG. 6 in a second configuration, and
FIG. 8 illustrates an opto-electronic device of this invention with a plurality of guiding fins.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring firstly to FIGS. 1 to 3 , an opto-electronic device 100 comprises a housing 110 , a lead-frame 130 and opto-electronic circuitry 140 is shown. The opto-electronic circuitry 140 comprises an opto-electronic signal conversion device such as, for example, an optical transmitter with a laser or an LED source, an optical receiver with a photo-detector, or an optical transceiver where appropriate. Preferably, the opto-electronic circuitry 140 comprises an integrated circuit (IC) chip. The opto-electronic circuitry 140 is mounted and connected to a conductive lead-frame for external connection. The housing 110 comprises a lower housing 112 and an upper housing 120 . The lower housing 112 is made of plastics and is moulded with the lead-frame at between the lateral ends of the legs 132 of the lead-frame 130 . The plastic lower housing 112 is moulded so that compartment 114 with a top aperture 116 surrounded by peripheral walls 118 is formed. The opto-electronic circuitry 140 is placed in this hollow compartment 114 and is supported by a platform of the lead-frame which is in turn supported by the lower plastic housing 112 . The opto-electronic circuitry 140 is fixed in place by transparent fastening substances such as resin or other appropriate optically transparent medium. This transparent fastening medium also contributes to the fastening of the upper housing 120 to the lower housing 112 where appropriate.
The upper housing 120 is also made of plastics and comprises a cover lid 122 , a focusing lens 124 and an optical guide receptacle 126 . The optical guide receptacle 126 comprises an axial barrel defining an axially extending aperture for guiding an optical guide coupler axially towards the signal conversion means 142 (which is a photo-detector in case of an optical receiver or a laser or LED source in case of an optical transmitter) for optical alignment therewith. A stop 128 is disposed intermediate the top free end of the optical guide receptacle 126 and the focusing lens 124 which is disposed at the junction of the optical guide receptacle 126 and the cover lid 122 . The stop 128 provides adequate clearance between the head of an optical guide 150 and the focusing lens 124 . The internal bore 129 of the optical guide receptacle is adapted so that when an optical guide is duly received by the optical guide receptacle, the optical fibre 150 will be aligned with the signal conversion means 142 for optical communication.
In the arrangement of FIGS. 1 and 2 , the axis of the optical receptacle and the core of the optical fibre are coaxial, with their common axis aligned to the signal conversion means 142 . The upper housing 122 is attached to the lower housing 112 by, for example, ultra-sonic welding or glue fastening. To facilitate speedy assembly between the lower and upper housings, location means, such as slot and lug pairs may be correspondingly distributed on the corresponding periphery of the upper and lower housings. In order to ensure optimal alignment between the optical fibre module 152 and the opto-electronic signal conversion means 142 , the upper and lower housing may be fastened with a referencing or testing optical fibre module 152 received and operating within the optical guide receptacle so that the upper and lower housings are fastened together when an optimal signal output is detected. The focusing lens 124 is convex towards the optical fibre 150 . Of course, the focusing lens can be other appropriate lens such as a concave lens where appropriate.
The opto-electronic circuitry is mounted on a conductive platform of the lead-frame 130 . The plane of the conductive platform is substantially parallel to a plane defined by the flat portions of the free ends of the legs of the lead-frame. This plane of the platform is substantially orthogonal to the axis of the internal bore of the optical receptacle.
Referring to FIGS. 4 and 4A , a plurality of opto-electronic devices 100 are formed on a stamped metallic sheet 160 which comprises a plurality of lead-frames. Such lead-frame comprises a rigid legs and platform for mounting the opto-electronic circuitry. Hence, a plurality of lead-frame can be formed at the same time on a single metal sheet prior to the formation of separate lead-frame packaged devices and this substantially enhances production efficiency.
In a second preferred embodiment as shown in FIG. 5 , the opto-electronic device comprises an optical transmitter with a vertical-cavity surface-emitter laser (VCSEL). The VCSEL drive current and output power is controlled by an electronic driver chip plus passive components inside the package formed by the upper and lower housing. The output power of the VCSEL can be controlled by closed-loop monitoring wherein output light of the VCSEL is partially reflected by a reflector 210 mounted intermediate the focusing lens and the laser source 142 . The reflected light from the reflector 210 hits a monitor photo-diode mounted side-by-side to the laser source. The photo-current detected at the monitor photo-detector is a measure of the total laser output power which is fed back to the control circuitry for adjusting drive current and therefore stabilizing output power of the laser source. The additional components can be placed on an additional sub-mount inside the packaged device 200 . The lead-frame package is typically a through-hole mountable design or a surface mount design as shown more particularly in FIGS. 1-3 . After the components have been mounted inside the device compartment, the cover lid of the upper housing can be attached to the lower housing by glue. The cover lid can be aligned with the components inside the lower housing by active or passive alignment. In the active alignment mould, the upper and lower housing will be aligned when the VCSEL is emitting light and the light emission detected by a test optical fibre inserted in the barrel of the optical guide receptacle. In the passive alignment mould, the cover lid 122 of the upper housing is fastened to the periphery of the lower housing using appropriate mechanical location means.
The focusing means 124 is adapted for maximal coupling efficiency and/or wide alignment tolerances. The focusing lens 124 can be integrally formed with the upper housing or a detachable housing. The configuration comprising a lead-frame mounted with a housing with a pre-aligned optical barrel permits a wide mechanical alignment tolerances. This is particularly important because optical fibre termination modules often require a wide lateral alignment tolerance due to fabrication tolerances in fibre ferrule. A wide longitudinal alignment tolerance is preferred so as to facilitate elastic coupling between a fibre ferrule and an optical module. This characteristic is particularly useful in connection with an optical connector since a fibre ferrule can be very short to form a fibre stub type of device.
FIGS. 6 and 7 shows an exemplary application of the opto-electronic device 100 in which the fibre stub and the opto-electronic device are mechanically connected by a spring-type connector device. The distance of the ferrule and-facite to the lid alignment plane will vary depending on the resilience of the spring 170 . A wide longitudinal alignment tolerance of more than 0.5 mm can be obtained with such an arrangement. For example, in FIG. 6 , the fibre stub is pushed by external force towards the stub inside the optical barrel. The compressive force can be due to connection with another fibre. In FIG. 7 , there is no externally applied force on the fibre stub and the spring 170 is relaxed, whereby pushing the fibre stub away from the stub and the focusing lens. However, coupling of the signal conversion means with the fibre should remain as constant as possible over the entire longitudinal coupling range.
To further enhance speedy and accurate alignment between a fibre stub and the opto-electronic device, a plurality of radially extending fins may be formed on the formed on the exterior of the barrel 126 (as shown in FIG. 8 ) so as to guide insertion of an optical fibre stub into coupling with the signal-conversion means 124 of the device 100 .
In this specification, parts which are common to the various embodiments or examples use the same numerals where appropriate for succinctness.
While the present invention has been explained by reference to the examples or preferred embodiments described above, it will be appreciated that those are examples to assist understanding of the present invention and are not meant to be restrictive. Variations or modifications which are obvious or trivial to persons skilled in the art, as well as improvements made thereon, should be considered as equivalents of this invention.
Furthermore, while the present invention has been explained by reference to a laser source, it should be appreciated that the invention can apply, whether with or without modification, to other opto-electronic devices without loss of generality. | An opto-electronic device comprising opto-electronic circuitry on a lead-frame and an optical guide receptacle for receiving an optical guide coupler, the opto-electronic circuitry comprises signal conversion means whereby an optical signal can be converted into an electrical signal or vice versa, the optical guide receptacle comprises means for guiding reception of an optical guide coupler whereby an optical guide coupler is optically aligned with the signal conversion means when received by said optical guide receptacle. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to carbon nanotubes and fibers.
BACKGROUND OF THE INVENTION
[0002] Fibers are used for many different applications in a wide variety of industries, such as the commercial aviation, recreation, industrial and transportation industries. Commonly-used fibers for these and other applications include cellulosic fiber (e.g., viscose rayon, cotton, etc.), glass fiber, carbon fiber, and aramid fiber, to name just a few.
[0003] In many fiber-containing products, the fibers are present in the form of a composite material (e.g., fiberglass, etc.). A composite material is a heterogeneous combination of two or more constituents that differ in form or composition on a macroscopic scale. While the composite material exhibits characteristics that neither constituent alone possesses, the constituents retain their unique physical and chemical identities within the composite.
[0004] Two key constituents of a composite include a reinforcing agent and a resin matrix. In a fiber-based composite, the fibers are the reinforcing agent. The resin matrix keeps the fibers in a desired location and orientation and also serves as a load-transfer medium between fibers within the composite.
[0005] Fibers are characterized by certain properties, such as mechanical strength, density, electrical resistivity, thermal conductivity, etc. The fibers “lend” their characteristic properties, in particular their strength-related properties, to the composite. Fibers therefore play an important role in determining a composite's suitability for a given application.
[0006] To realize the benefit of fiber properties in a composite, there must be a good interface between the fibers and the matrix. This is achieved through the use of a surface coating, typically referred to as “sizing.” The sizing provides an all important physico-chemical link between fiber and the resin matrix and thus has a significant impact on the mechanical and chemical properties of the composite. The sizing is applied to fibers during their manufacture.
[0007] Substantially all conventional sizing has lower interfacial strength than the fibers to which it's applied. As a consequence, the strength of the sizing and its ability to withstand interfacial stress ultimately determines the strength of the overall composite. In other words, using conventional sizing, the resulting composite cannot have a strength that is equal to or greater than that of the fiber.
SUMMARY OF THE INVENTION
[0008] The illustrative embodiment of the present invention is a carbon nanotube-infused (“CNT-infused”) fiber.
[0009] In CNT-infused fiber disclosed herein, the carbon nanotubes are “infused” to the parent fiber. As used herein, the term “infused” means physically or chemically bonded and “infusion” means the process of physically or chemically bonding. The physical bond between the carbon nanotubes and parent fiber is believed to be due, at least in part, to van der Waals forces. The chemical bond between the carbon nanotubes and the parent fiber is believed to be a covalent bond.
[0010] Regardless of its true nature, the bond that is formed between the carbon nanotubes and the parent fiber is quite robust and is responsible for CNT-infused fiber being able to exhibit or express carbon nanotube properties or characteristics. This is in stark contrast to some prior-art processes, wherein nanotubes are suspended/dispersed in a solvent solution and applied, by hand, to fiber. Because of the strong van der Waals attraction between the already-formed carbon nanotubes, it is extremely difficult to separate them to apply them directly to the fiber. As a consequence, the lumped nanotubes weakly adhere to the fiber and their characteristic nanotube properties are weakly expressed, if at all.
[0011] The infused carbon nanotubes disclosed herein effectively function as a replacement for conventional “sizing.” It has been found that infused carbon nanotubes are far more robust molecularly and from a physical properties perspective than conventional sizing materials. Furthermore, the infused carbon nanotubes improve the fiber-to-matrix interface in composite materials and, more generally, improve fiber-to-fiber interfaces.
[0012] The CNT-infused fiber disclosed herein is itself similar to a composite material in the sense that its properties will be a combination of those of the parent fiber as well as those of the infused carbon nanotubes. Consequently, embodiments of the present invention provide a way to impart desired properties to a fiber that otherwise lacks such properties or possesses them in insufficient measure. Fibers can therefore be tailored or engineered to meet the requirements of a specific application. In this fashion, the utility and value of virtually any type of fiber can be improved.
[0013] In accordance with the illustrative embodiment of a CNT-infused fiber-forming process, nanotubes are synthesized in place on the parent fiber itself. It is important that the carbon nanotubes are synthesized on the parent fiber. If not, the carbon nanotubes will become highly entangled and infusion does not occur. As seen from the prior art, non-infused carbon nanotubes impart little if any of their characteristic properties.
[0014] The parent fiber can be any of a variety of different types of fibers, including, without limitation: carbon fiber, graphite fiber, metallic fiber (e.g., steel, aluminum, etc.), ceramic fiber, metallic-ceramic fiber, glass fiber, cellulosic fiber, aramid fiber.
[0015] In the illustrative embodiment, nanotubes are synthesized on the parent fiber by applying or infusing a nanotube-forming catalyst, such as iron, nickel, cobalt, or a combination thereof, to the fiber.
[0016] In some embodiments, operations of the CNT-infusion process include:
[0017] Removing sizing from the parent fiber;
[0018] Applying nanotube-forming catalyst to the parent fiber;
[0019] Heating the fiber to nanotube-synthesis temperature; and
[0020] Spraying carbon plasma onto the catalyst-laden parent fiber.
[0021] In some embodiments, the infused carbon nanotubes are single-wall nanotubes. In some other embodiments, the infused carbon nanotubes are multi-wall nanotubes. In some further embodiments, the infused carbon nanotubes are a combination of single-wall and multi-wall nanotubes. There are some differences in the characteristic properties of single-wall and multi-wall nanotubes that, for some end uses of the fiber, dictate the synthesis of one or the other type of nanotube. For example, single-walled nanotubes can be excellent conductors of electricity while multi-walled nanotubes are not.
[0022] Methods and techniques for forming carbon nanotubes, as disclosed in co-pending U.S. patent application Ser. No. 10/455,767 (Publication No. US 2004/0245088) and which is incorporated herein by reference, can be adapted for use with the process described herein. In the illustrative embodiment, acetylene gas is ionized to create a jet of cold carbon plasma. The plasma is directed toward the catalyst-bearing parent fiber.
[0023] As previously indicated, carbon nanotubes lend their characteristic properties (e.g., exceptional mechanical strength, low to moderate electrical resistivity, high thermal conductivity, etc.) to the CNT-infused fiber. The extent to which the resulting CNT-infused fiber expresses these characteristics is a function of the extent and density of coverage of the parent fiber by the carbon nanotubes.
[0024] In a variation of the illustrative embodiment, CNT infusion is used to provide an improved filament winding process. In this variation, carbon nanotubes are formed on fibers (e.g., graphite tow, glass roving, etc.), as described above, and are then passed through a resin bath to produce resin-impregnated, CNT-infused fiber. After resin impregnation, the fiber is positioned on the surface of a rotating mandrel by a delivery head. The fiber then winds onto the mandrel in a precise geometric pattern in known fashion.
[0025] The filament winding process described above provides pipes, tubes, or other forms as are characteristically produced via a male mold. But the forms made from the filament winding process disclosed herein differ from those produced via conventional filament winding processes. Specifically, in the process disclosed herein, the forms are made from composite materials that include CNT-infused fibers. Such forms will therefore benefit from enhanced strength, etc., as provided by the CNT-infused fibers.
[0026] Any of a variety of different parent fibers can be used to form CNT-infused fiber,
[0027] Of late, there has been a demand for carbon fiber forms that are compatible with a broad range of resins and processes. And the sizing material is an important determinant of this compatibility. For example, sizing is critically important for providing an even distribution of chopped carbon fiber in sheet molding compounds (“SMCs”), such as are used in some automotive body panels.
[0028] Notwithstanding this demand for carbon fiber and its potentially broad applicability, carbon fiber has historically been sized for compatibility with only epoxy resin. CNT-infused carbon fiber, as produced according to the method disclosed herein, addresses this problem by providing a fiber that is sized with infused nanotubes, which provides the desired broad applicability with a variety of resins and processes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 depicts a method for producing CNT-infused fiber in accordance with the illustrative embodiment of the present invention.
[0030] FIG. 2 depicts a system for implementing the illustrative method for producing CNT-infused fiber.
[0031] FIG. 3 depicts a system for filament winding in accordance with a variation of the illustrative embodiment.
DETAILED DESCRIPTION
[0032] The following terms are defined for use in this Specification, including the appended claims:
[0033] Carding—The process by which the fibers are opened out into an even film.
[0034] Carded Fibers—Fibers that have been carded which opens them up.
[0035] Cloth—A reinforcement material made by weaving strands of fiber yarns.
[0036] Continuous Filament Strand—A fiber bundle composed of many filaments. Also, when referring to gun roving; a collection of string-like fiber or yarn, which is fed through a chopper gun in a spray-up process.
[0037] Continuous Strand Roving—A bundle of filaments which are fed through a chopper gun in a spray-up process.
[0038] Fabric—A planar textile structure produced by interlacing yarns, fibers, or filaments.
[0039] Fiber—A unit of matter, either natural, or manufactured, which forms the basic element of fabrics and other textile structures.
[0040] Fiber orientation—Fiber alignment in a non-woven or a mat laminate where the majority of fibers are in the same direction, resulting in a higher strength in that direction.
[0041] Fiber Pattern—Visible fibers on the surface of laminates or moldings; the thread size and weave of glass cloth.
[0042] Filament—A single fiber of an indefinite or extreme length, either natural (e.g., silk, etc.) or manufactured. Typically microns in diameter, manufactured fibers are extruded into filaments that are converted into filament yarn, staple, or tow.
[0043] Filament Winding—A process which involves winding a resin-saturated strand of glass filament around a rotating mandrel.
[0044] Filament Yarn—A yarn composed of continuous filaments assembled with, or without twist.
[0045] Infuse—To form a chemical bond.
[0046] Male Mold—A convex mold where the concave surface of the part is precisely defined by the mold surface.
[0047] Matrix—The liquid component of a composite or laminate.
[0048] Mandrel—The core around which paper-, fabric-, or resin-impregnated fiber is wound to form pipes, tubes, or vessels; in extrusion, the central finger of a pipe or tubing die.
[0049] Pultrusion—Reversed “extrusion” of resin-impregnated roving in the manufacture of rods, tubes and structural shapes of a permanent cross-section. The roving, after passing through the resin dip tank, is drawn through a die to form the desired cross-section.
[0050] Resin—A liquid polymer that, when catalyzed, cures to a solid state.
[0051] Roving—The soft strand of carded fiber that has been twisted, attenuated, and freed of foreign matter preparatory to spinning.
[0052] Sizing—A surface treatment that is applied to filaments immediately after their formation for the purpose of promoting good adhesion between those filaments and the matrix, to the extent the filaments are to be used as the reinforcing agent in a composite material.
[0053] Spray-up—The process of spraying fibers, resin and catalyst simultaneously into a mold using a chopper gun.
[0054] Strands—A primary bundle of continuous filaments (or slivers) combined in a single compact unit without twist. These filaments (usually 51, 102 or 204) are gathered together in the forming operations.
[0055] Tape—a narrow-width reinforcing fabric or mat.
[0056] Tow—a loose strand of filaments without twist.
[0057] Twist—A term that applies to the number of turns and the direction that two yarns are turned during the manufacturing process.
[0058] Woven Roving Fabric—Heavy fabrics woven from continuous filament in roving form. Usually in weights between 18-30 oz. per square yard.
[0059] Yarn—A generic term for a continuous strand of textile fibers, filaments, or material in a form suitable for knitting, weaving, braiding, or otherwise intertwining to form a textile fabric.
[0060] As the definitions that are provided above indicate, terms such as “fiber,” “filament,” “yarn,” etc., have distinct meanings. But for the purposes of the specification and the appended claims, and unless otherwise indicated, the term “fiber” is used in this specification as a generic term to refer to filament, yarn, tow, roving, fabric, etc., as well as fiber itself. The phrase “CNT-infused fiber” is therefore understood to encompass “CNT-infused fiber,” “CNT-infused filament,” “CNT-infused tow,” CNT-infused roving,” etc.
[0061] FIG. 1 depicts a flow diagram of process 100 for producing CNT-infused fiber in accordance with the illustrative embodiment of the present invention.
[0062] Process 100 includes the operations of:
[0063] 102 : Applying nanotube-forming catalyst to the parent fiber.
[0064] 104 : Heating the parent fiber to a temperature that is sufficient for carbon nanotube synthesis.
[0065] 106 : Spraying carbon plasma onto the catalyst-laden parent fiber.
[0066] To infuse carbon nanotubes into a parent fiber, the carbon nanotubes are synthesized directly on the parent fiber. In the illustrative embodiment, this is accomplished by disposing nanotube-forming catalyst on the parent fiber, as per operation 102 . Suitable catalysts for carbon nanotube formation include, without limitation, transition metal catalysts (e.g., iron, nickel, cobalt, combinations thereof, etc.).
[0067] As described further in conjunction with FIG. 2 , the catalyst is prepared as a liquid solution that contains nano-sized particles of catalyst. The diameters of the synthesized nanotubes are related to the size of the metal particles.
[0068] In the illustrative embodiment, carbon nanotube synthesis is based on a plasma-enhanced chemical vapor deposition process and occurs at elevated temperatures. The temperature is a function of catalyst, but will typically be in a range of about 500 to 1000° C. Accordingly, operation 104 requires heating the parent fiber to a temperature in the aforementioned range to support carbon nanotube synthesis.
[0069] In operation 106 , carbon plasma is sprayed onto the catalyst-laden parent fiber. The plasma can be generated, for example, by passing a carbon containing gas (e.g., acetylene, ethylene, ethanol, etc.) through an electric field that is capable of ionizing the gas.
[0070] Nanotubes grow at the sites of the metal catalyst. The presence of the strong plasma-creating electric field can affect nanotube growth. That is, the growth tends to follow the direction of the electric field. By properly adjusting the geometry of the plasma spray and electric field, vertically-aligned carbon nanotubes (i.e., perpendicular to the fiber) are synthesized. Under certain conditions, even in the absence of a plasma, closely-spaced nanotubes will maintain a vertical growth direction resulting in a dense array of tubes resembling a carpet or forest.
[0071] FIG. 2 depicts system 200 for producing CNT-infused fiber in accordance with the illustrative embodiment of the present invention. System 200 includes fiber payout and tensioner station 202 , fiber spreader station 208 , sizing removal station 210 , CNT-infusion station 212 , fiber bundler station 222 , and fiber uptake bobbin 224 , interrelated as shown.
[0072] Payout and tension station 202 includes payout bobbin 204 and tensioner 206 . The payout bobbin delivers fiber 201 to the process; the fiber is tensioned via tensioner 206 .
[0073] Fiber 201 is delivered to fiber spreader station 208 . The fiber spreader separates the individual elements of the fiber. Various techniques and apparatuses can be used to spread fiber, such as pulling the fiber over and under flat, uniform-diameter bars, or over and under variable-diameter bars, or over bars with radially-expanding grooves and a kneading roller, over a vibratory bar, etc. Spreading the fiber enhances the effectiveness of downstream operations, such as catalyst application and plasma application, by exposing more fiber surface area.
[0074] Payout and tension station 202 and fiber spreader station 208 are routinely used in the fiber industry; those skilled in the art will be familiar with their design and use.
[0075] Fiber 201 then travels to sizing removal station 210 . At this station, any “sizing” that is on fiber 201 is removed. Typically, removal is accomplished by burning the sizing off of the fiber.
[0076] Any of a variety of heating means can be used for this purpose, including, without limitation, an infrared heater, a muffle furnace, etc. Generally, non-contact heating methods are preferred. In some alternative embodiments, sizing removal is accomplished chemically.
[0077] The temperature and time required for burning off the sizing vary as a function of (1) the sizing material (e.g., silane, etc.); and (2) the identity of parent fiber 201 (e.g., glass, cellulosic, carbon, etc.). Typically, the burn-off temperature is a minimum of about 650° C. At this temperature, it can take as long as 15 minutes to ensure a complete burn off of the sizing. Increasing the temperature above a minimum burn temperature should reduce burn-off time. Thermogravimetric analysis can be used to determine minimum burn-off temperature for sizing.
[0078] In any case, sizing removal is the slow step in the overall CNT-infusion process. For this reason, in some embodiments, a sizing removal station is not included in the CNT-infusion process proper; rather, removal is performed separately (e.g., in parallel, etc.). In this way, an inventory of sizing-free fiber can be accumulated and spooled for use in a CNT-infused fiber production line that does not include a fiber removal station). In such embodiments, sizing-free fiber is spooled in payout and tension station 202 . This production line can be operated at higher speed than one that includes sizing removal.
[0079] Sizing-free fiber 205 is delivered to CNT-infusion station 212 , which is the “heart” of the process and system depicted in FIG. 2 . Station 212 includes catalyst application station 214 , fiber pre-heater station 216 , plasma spray station 218 , and fiber heaters 220 .
[0080] As depicted in FIG. 2 , sizing-free fiber 205 proceeds first to catalyst application station 214 . In some embodiments, fiber 205 is cooled prior to catalyst application.
[0081] In some embodiments, the nanotube-forming catalyst is a liquid solution of nanometer-sized particles (e.g., 10 nanometers in diameter, etc.) of a transition metal. Typical transition metals for use in synthesizing nanotubes include, without limitation, iron, iron oxide, cobalt, nickel, or combinations thereof. These transition metal catalysts are readily commercially available from a variety of suppliers, including Ferrotech of Nashua, NH. The liquid is a solvent such as toluene, etc.
[0082] In the illustrative embodiment, the catalyst solution is sprayed, such as by air sprayer 214 , onto fiber 205 . In some other embodiments, the transition metal catalyst is deposited on the parent fiber using evaporation techniques, electrolytic deposition techniques, suspension dipping techniques and other methods known to those skilled in the art. In some further embodiments, the transition metal catalyst is added to the plasma feedstock gas as a metal organic, metal salt or other composition promoting gas phase transport. The catalyst can be applied at room temperature in the ambient environment (neither vacuum nor an inert atmosphere is required).
[0083] Catalyst-laden fiber 207 is then heated at fiber preheater station 216 . For the infusion process, the fiber should be heated until it softens. Generally, a good estimate of the softening temperature for any particular fiber is readily obtained from reference sources, as is known to those skilled in the art. To the extent that this temperature is not a priori known for a particular fiber, it can be readily determined by experimentation. The fiber is typically heated to a temperature that is in the range of about 500 to 1000° C. Any of a variety of heating elements can be used as the fiber preheater, such as, without limitation, infrared heaters, a muffle furnace, and the like.
[0084] After preheating, fiber 207 is finally advanced to plasma spray station having spray nozzles 218 . A carbon plasma is generated, for example, by passing a carbon containing gas (e.g., acetylene, ethylene, ethanol, etc.) through an electric field that is capable of ionizing the gas. This cold carbon plasma is directed, via spray nozzles 218 , to fiber 207 . The fiber is disposed within about 1 centimeter of the spray nozzles to receive the plasma. In some embodiments, heaters 220 are disposed above fiber 207 at the plasma sprayers to maintain the elevated temperature of the fiber.
[0085] After CNT-infusion, CNT-infused fiber 209 is re-bundled at fiber bundler 222 . This operation recombines the individual strands of the fiber, effectively reversing the spreading operation that was conducted at station 208 .
[0086] The bundled, CNT-infused fiber 209 is wound about uptake fiber bobbin 224 for storage. CNT-infused fiber 209 is then ready for use in any of a variety of applications, including, without limitation, for use as the reinforcing material in composite materials.
[0087] It is noteworthy that some of the operations described above should be conducted under inert atmosphere or vacuum, such that environmental isolation is required. For example, if sizing is being burned off of the fiber, the fiber must be environmentally isolated to contain off-gassing and prevent oxidation. Furthermore, the infusion process should be conducted under an inert atmosphere (e.g., nitrogen, argon, etc.) to prevent oxidation of the carbon. For convenience, in some embodiments of system 200 , environmental isolation is provided for all operations, with the exception of fiber payout and tensioning (at the beginning of the production line) and fiber uptake (at the end of the production line).
[0088] FIG. 3 depicts a further embodiment of the invention wherein CNT-infused fiber is created as a sub-operation of a filament winding process being conducted via filament winding system 300 .
[0089] System 300 comprises fiber creel 302 , carbon nanotube infusion section 226 , resin bath 328 , and filament winding mandrel 332 , interrelated as shown. The various elements of system 300 , with the exception of carbon nanotube infusion section 226 , are present in conventional filament winding processes. Again, the “heart” of the process and system depicted in FIG. 3 is the carbon nanotube infusion section 226 , which includes fiber spreader station 208 , (optional) sizing-removal station 210 , and CNT-infusion station 212 .
[0090] Fiber creel 302 includes plural spools 204 of parent fiber 201 A through 201 H. The untwisted group of fibers 201 A through 201 H is referred to collectively as “tow 303 .” Note that the term “tow” generally refers to a group of graphite fibers and the term “roving” usually refers to glass fibers. Here, the term “tow” is meant to refer, generically, to any type of fiber.
[0091] In the illustrative embodiment, creel 302 holds spools 204 in a horizontal orientation. The fiber from each spool 206 moves through small, appropriately situated rollers/tensioners 206 that change the direction of the fibers as they move out of creel 302 and toward carbon nanotube infusion section 226 .
[0092] It is understood that in some alternative embodiments, the spooled fiber that is used in system 300 is CNT-infused fiber (i.e., produced via system 200 ). In such embodiments, system 300 is operated without nanotube infusion section 226 .
[0093] In carbon nanotube infusion section 226 , tow 303 is spread, sizing is removed, nanotube-forming catalyst is applied, the tow is heated, and carbon plasma is sprayed on the fiber, as described in conjunction with FIG. 2 .
[0094] After passing through nanotube infusion section 226 , CNT-infused tow 307 is delivered to resin bath 328 . The resin bath contains resin for the production of a composite material comprising the CNT-infused fiber and the resin. Some important commercially-available resin-matrix families include general purpose polyester (e.g., orthophthalic polyesters, etc.), improved polyester (e.g., isophthalic polyesters, etc.), epoxy, and vinyl ester.
[0095] Resin bath can be implemented in a variety of ways, two of which are described below. In the illustrative embodiment, resin bath 328 is implemented as a doctor blade roller bath wherein a polished rotating cylinder (e.g., cylinder 330 ) that is disposed in the bath picks up resin as it turns. The doctor bar (not depicted in FIG. 3 ) presses against the cylinder to obtain a precise resin film thickness on cylinder 330 and pushes excess resin back into the bath. As fiber tow 307 is pulled over the top of cylinder 330 , it contacts the resin film and wets out. In some other embodiments, resin bath 328 is realized as an immersion bath wherein fiber tow 307 is simply submerged into resin and then pulled through a set of wipers or roller that remove excess resin.
[0096] After leaving resin bath 328 , resin-wetted, CNT-infused fiber tows 309 is passed through various rings, eyelets and, typically, a multi-pin “comb” (not depicted) that is disposed behind a delivery head (not depicted). The comb keeps the fiber tows 2309 separate until they are brought together in a single combined band on rotating mandrel 332 .
EXAMPLE
[0097] A CNT-infused carbon fiber was formed in accordance with the illustrative embodiment. A current was passed through carbon fiber (the parent fiber) to heat it to approximately 800° C. to remove epoxy sizing material. The fiber was then cooled to room temperature and left clamped between electrodes. A ferro-fluid catalyst was applied to the fiber using an aerosol spray technique. The fiber was allowed to dry and the chamber was closed, evacuated and filled with argon. A current was passed through the carbon fiber again to heat it to approximately 800 C for carbon nanotube synthesis. A carbon plasma was generated from acetylene precursor using 13.56 MHz microwave energy using an atmospheric pressure plasma jet. The carrier gas in the plasma jet was helium at 20 standard liters per minute (slm) and the argon was provided at 1.2 slm. The plasma jet was fixtured to a robotic motion control system allowing the plasma jet to move over the length of the fiber at a speed between 6 and 12 inches per minute. The CNT-infused fiber was then cooled to room temperature and removed from the chamber. Scanning Electron Microscopy showed carbon nanotube formation on the surface of the parent carbon fiber.
[0098] It is to be understood that the above-described embodiments are merely illustrative of the present invention and that many variations of the above-described embodiments can be devised by those skilled in the art without departing from the scope of the invention. For example, in this Specification, numerous specific details are provided in order to provide a thorough description and understanding of the illustrative embodiments of the present invention. Those skilled in the art will recognize, however, that the invention can be practiced without one or more of those details, or with other methods, materials, components, etc.
[0099] Furthermore, in some instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the illustrative embodiments. It is understood that the various embodiments shown in the Figures are illustrative, and are not necessarily drawn to scale. Reference throughout the specification to “one embodiment” or “an embodiment” or “some embodiments” means that a particular feature, structure, material, or characteristic described in connection with the embodiment(s) is included in at least one embodiment of the present invention, but not necessarily all embodiments. Consequently, the appearances of the phrase “in one embodiment,” “in an embodiment,” or “in some embodiments” in various places throughout the Specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments. It is therefore intended that such variations be included within the scope of the following claims and their equivalents. | A carbon nanotube-infused fiber and a method for its production are disclosed. Nanotubes are synthesized directly on a parent fiber by first applying a catalyst to the fiber. The properties of the carbon nanotube-infused fiber will be a combination of those of the parent fiber as well as those of the infused carbon nanotubes. | 2 |
The invention described herein may be made, used and licensed by or for the U.S. Government for governmental purposes without paying me any royalty.
BACKGROUND OF THE INVENTION
1. Field of the Invention
In one aspect this invention relates to cooling systems for use in land vehicles having a prime mover which must be cooled using a liquid coolant. In a further aspect, this invention relates to a method for providing electrical power to the vehicle for various uses.
2. Prior Art
In general the use of liquid coolant systems in vehicles is well known. The most common example is the ubiquitous automobile radiator. Such radiators have a closed loop cooling system wherein the liquid coolant, generally water with one or more additives, is constantly circulated while the engine, prime mover, is in operation. The passage of air through the radiator structure removes heat from the coolant and keeps the engine from overheating.
Military vehicles operate under more stressful conditions than the normal land vehicle and consequently they require superior cooling and heating parameters. In addition, they require substantial quantities of electrical power to operate a wide variety of electrical devices necessary to steer, maneuver, and fire weapons.
SUMMARY OF THE INVENTION
Briefly the present invention is an improved radiator system which can aid in cooling the prime mover and provide a source of additional electrical current. The radiator system is formed using a thermoelectric structure to provide at least a portion of the cooling and also as a source of current. The improved thermoelectric radiator structure has a first plurality of spaced lamella formed of a first thermoelectric material and a second plurality of spaced lamella formed of a second thermoelectric material. The first and second plurality of lamella are interdigitated with the first and second plurality of lamella being electrically bonded at the junctures between the lamella. A first electrical buss electrically connects all the first lamella of thermoelectric material, and a second buss electrically connects the second lamella of thermoelectric material. The first and second busses are connected to the appropriate electrical poles of the prime mover electrical system. During operation of the vehicle, the passage of heated coolant over the surfaces of the first and second lamella provides a current to the electrical system and extracts heat from the fluid flow.
BRIEF DESCRIPTION OF THE DRAWING
In the accompanying drawing:
FIG. 1 is a isometric view of one embodiment of this invention;
FIG. 2 is partial view in section of the structure of FIG. 1; and
FIG. 3 is a partial view in section of a second lamellar design useful in the practice of this invention.
DETAILED DESCRIPTION
Referring to the accompanying drawing in which like numerals refer to like parts and initially to FIG. 1, an improved radiator 10 of this invention is shown for use in a land vehicle (not shown) having a prime mover as a source of motive power. As is common with such vehicles the prime mover requires cooling, the cooling being done with a closed loop recirculating liquid coolant system. The closed loop system has a pump for circulating a liquid coolant within the closed loop system. Such cooling systems are known in the art of land vehicle design and a detailed description is omitted in the interest of brevity.
The improved radiator 10 has a thermoelectric radiator structure 12 connected to the remainder of the cooling system at an inlet 14 with a fluid fill aperture 16 sealed by a removable cap 18 which can be opened to replenish the coolant. A conventional radiator structure 20 is connected to the thermoelectric radiator 12 and is adapted to receive the coolant from the thermoelectric radiator and remove additional heat. The conventional radiator structure 20 is connected to the cooling system by outlet 22 to return the lower temperature coolant to the prime mover for further heat transfer.
The improved radiator structure 10 sits on a base 24 which can be mounted in the land vehicle using standard mounting and bracketing techniques and engineering principles. The mounting techniques are not part of this invention.
A portion of the thermoelectric radiator 12 is shown enlarged in FIG. 2. A chamber 26 is fluidly connected to the remainder of the closed loop liquid coolant system to receive heated coolant from the prime mover or power source as described above. The chamber 26 has an upper closure 28 shown in FIG. 1. with the inlet 14 formed therein. At the lower end of the chamber 26 is an outlet not shown to direct coolant from the thermoelectric portion 12 to the conventional radiator section 20.
The chamber 26 has at least one wall formed as a thermoelectric device to generate electric current while extracting heat from the coolant. The thermoelectric radiator 12 as detailed in FIG. 2, has a first plurality of spaced lamella 28 formed of a first thermoelectric material, the first lamella having a T-shaped cross section with cross bars 30 and legs 32. The first lamella 28 are arranged so that their cross bars 30 are aligned in a plane forming a part of the inner wall 34 of the chamber 26. The cross bars 30 are separated by a discrete distance and the legs 32 of the first lamella extend outward away from the chamber 26. Each of the legs 32 has a tab member 36 extending past the outer face 38 of the thermoelectric radiator 12. The tabs 36 are electrically connected by means of a bus 40 which provides an electrical link to all the first lamella 28. The bus 40 is connected to one pole of the vehicle electrical system. The current flow can be used to recharge the battery or provide additional power to be used on the electrical systems of the vehicle. The bus 40 is formed of a good conducting material such as a copper wire.
A second plurality of spaced lamella, 50 having a T-shaped cross section, are arranged so that their cross bars 52 are disposed coplanar with the cross bars 30 of first lamella 28 and the legs 54 of second lamella 50 extend parallel to and aligned with the legs 32 of the first lamella. The second lamella 50 are formed of a second thermoelectric material different from the first thermoelectric material. The cross bars 52 of the second lamella 50 are interdigitated with the cross bars 30 of the first plurality of lamella 28 and the juxtaposed surfaces of the cross bars 30, 52 are electrically bonded at their junctures to form an electrical couple. The joint must perforce also provide a fluid impermeable wall for the chamber 26 to contain coolant. The legs 54, 32 are separated by layers of insulating material 60.
The lamella of FIG. 2 are shown as T-shaped however it is understood that the lamella could be formed with other cross sections. For example, FIG. 3 shows a second embodiment where the lamella are formed with an L-shaped cross section. In this embodiment chamber 26 again has at least one wall formed as a thermoelectric device. A first plurality of spaced lamella 78, are formed with the first lamella having a L-shaped cross section including arms 80 and legs 82. The first lamella 78 are arranged so that their arms 80 are aligned in a plane forming a part of the inner wall 84 of the chamber 26. The arms 80 are separated by a discrete distance and the legs 82 of the first lamella extend outward away from the chamber 26. Each of the legs 82 has a tab member 36 extending past the outer face of the thermoelectric chamber. The tabs 36 are electrically connected by means of a bus 40 which provides an electrical link to all the first lamella 78.
A second plurality of spaced lamella, 90 having an L-shaped cross section are arranged so that their arms 92 are disposed coplanar with the arms 80 of first lamella 78 and the legs 94 of second lamella 90 extend parallel to and aligned with the legs 82 of the first lamella. The second lamella 90 are formed of a second thermoelectric material different from the first thermoelectric material as described before. The arms 92 of the second lamella 90 are interdigitated with the arms 80 of the first plurality of lamella 78. The juxtaposed surfaces of the arms 80, 92 are electrically bonded at their junctures to form an electrical couple.
The first and second lamella are formed of materials which generate an electrical potential when they are electrically bonded and a temperature gradient exists between the electrically connected portion of the lamella and the nonelectrically connected portions of the lamella. For example one set of lamella can be formed from an iron material and the second set of lamella can be formed from constantin. The two sets of lamella are joined by a process which yields an electrically conductive system such as eutectic soldering. Of course the process must also yield a liquid impermeable joint.
It may be desirable to provide a plurality of insulating layers between the lamella and such an insulating layer is shown as layers 60 the insulating layers, providing a thermal barrier. The insulating layers 60 can be formed of various insulating materials such as rubber or fiberglass compounds useful at the operating temperatures of the average radiator. As shown in FIG. 3 the insulating layers do not extend to the edge of the lamella they are insulating to allow a portion of the thermoelectric material to be exposed to ambient temperature conditions. This will increase the thermal gradient and maximize the current potential.
Various alterations and modifications will become apparent to those skilled in the art without departing from the scope and spirit of this invention and it is understood this invention is limited only by the following claims. | A thermoelectric radiator for generating a direct current while providing at least a portion of the necessary cooling is formed with a first and second plurality of interdigitated thermoelectric lamella which are electrically joined and are connected to the positive and negative portions of the electrical system. The result is direct current flow when a heated coolant is passed over the lamella. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority under 35 U.S.C. §119(a) to German Application No. 10 2009 001 355.5, filed on Mar. 5, 2009, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
This disclosure relates to impedance matching, wherein transformation of the impedance of a load to a nominal impedance range is carried out in a normal matching mode by a first reactance arrangement.
BACKGROUND
The surface treatment of workpieces using plasma and gas lasers is an industrial process in which a plasma is produced, in particular in a plasma chamber, by direct current or by a high-frequency alternating signal having a working frequency in the range from some 10 kHz into the GHz range. The plasma chamber is connected via further electronic components, such as inductors, capacitors, lines or transformers, to a high-frequency generator (HF generator). Those further components may form oscillating circuits, filters or impedance matching circuits. The electrical load impedance of the plasma chamber (the plasma) which arises during the process depends on the conditions in the plasma chamber and may vary greatly. In particular, the properties of the workpiece, electrodes, and gas ratios are a consideration. High-frequency generators have a limited working range with regard to the impedance of the connected electrical load. If the load impedance leaves a permissible range, the high-frequency generator may be damaged or even destroyed.
For that reason, an impedance matching circuit (matchbox) is generally required which transforms the impedance of the load to a nominal impedance of the generator output (typically 50Ω). If there is a mismatch, it is not possible for the full generator power to be supplied to the load. Instead, some of the power is reflected. In the region of the nominal impedance there is an impedance range, that is, a range of transformed load impedances, in which the generator operates in a stable manner and is not damaged. If the transformed load impedance is outside that nominal impedance range, damage to the generator and instability of the generator may occur as a result of reflected power.
Some impedance matching circuits have a fixed setting or a predefined transforming effect, that is, they consist of electrical components, especially inductors and capacitors, that are not altered during operation. That is appropriate particularly when operation always remains constant, for example in the case of a gas laser. In other impedance matching circuits, at least some of the components of the impedance matching circuits are mechanically variable. For example, in motor-driven rotary capacitors, the capacitance can be varied by altering the arrangement of the capacitor plates relative to one another.
Broadly speaking, three impedance ranges may be associated with a plasma. Before ignition, very high impedances are present. In normal operation, i.e. when working with plasma in accordance with its intended use, lower impedances are present. In the case of undesired local discharges (arcs) or in the case of plasma fluctuations, very low impedances may occur. In addition to the three impedance ranges identified, further, special conditions with other associated impedance values may occur. If the load impedance changes abruptly and if in that case the load impedance or the transformed load impedance leaves a permissible impedance range, the generator and/or the transmission circuitry between the generator and the plasma chamber may be damaged.
PIN diodes are electronic components constructed similarly to a pn diode. In contrast to the pn diode, however, the p-doped layer is not in direct contact with the n-doped layer, but a weakly doped or undoped i-layer lies in between. That i-layer is intrinsic. Since it contains only few charge carriers, however, it has a high resistance. In the forward direction, the PIN diode operates similarly to a normal semiconductor diode. In the case of PIN diodes, however, the lifetime of the charge carriers in the undoped i-layer (i-region) is particularly high. When charge carriers are brought into the i-layer by a forward current, the PIN diode remains constantly conductive even when a high frequency is superposed on the forward current and, as a result, short voltage pulses are periodically applied in the reverse direction. In that state, a PIN diode behaves like a resistor. In the completely switched-on state, voltage drops in the order of magnitude of the forward voltage of the semiconductor material used still occur.
If the diode is operated by applying a direct voltage in the reverse direction, a space charge region of differing width is produced in the p-region and the i-region. Owing to the wide space charge region in the i-region, those diodes are suitable for high reverse bias voltages. For a superposed high frequency, a reverse-biased PIN diode essentially represents a capacitor formed by the depletion layer.
Owing to its behavior as a resistor at high frequencies, a PIN diode may be used as a dc-controlled ac voltage resistor or as a high-frequency switch. In that case, a high-frequency alternating current and a direct current in the forward direction or a dc voltage in the reverse direction may be superposed, thereby enabling the resistance of the i-region to be controlled.
In some impedance matching circuits the mechanically variable reactances (e.g., rotary capacitors, roller inductors) are replaced by capacitor or inductor arrangements controlled by PIN diodes. For example, U.S. Pat. No. 7,226,524 discloses switching in capacitors via PIN diodes in normal matching mode, U.S. Pat. No. 4,486,722 discloses short-circuiting coil sections or switching in capacitors in normal matching mode, and U.S. Pat. No. 5,654,679 describes varying a capacitor by selecting capacitor subunits. However, a great number of PIN diodes with associated activation elements may be required, resulting in an expensive circuit. In addition, high losses may occur since switched-on PIN diodes are not without resistance and reverse-biased PIN diodes are not unrestrictedly good insulators. Still further, some arrangements may not be fast enough to prevent damage to the HF generator or the PIN diodes if there is a sudden change in impedance. Furthermore, parts of inductors carrying HF current that are short-circuited by PIN diodes or inductors short-circuited by PIN diodes and magnetically coupled to inductors carrying HF current may produce losses due to induced currents.
SUMMARY
In one aspect, an impedance matching circuit is provided with which impedance matching may be carried out in normal matching mode with low losses and with which an HF generator may be reliably protected. The impedance matching circuit is selectively operable in a normal matching mode and a protection mode and includes a PIN diode switch which in the normal matching mode has a first defined (invariable) switching state and in a protection mode has a second switching state that reconfigures a set of reactances from a first reactance arrangement into a second reactance arrangement, such that the second reactance arrangement is configured to transform an impedance of the load to prevent damage to the HF generator or to transmission circuitry arranged between the HF generator and the load.
A reactance arrangement is an arrangement of a set of reactances (e.g., inductances, capacitances and/or transformation members, such as lines of a certain length), that carries out a certain impedance matching. The reactance arrangement for the normal matching mode may be a fixed arrangement, i.e. the capacitance values and the inductance values of the individual reactances of the reactance arrangement are not variable during normal matching mode. In normal matching mode, the PIN diode switches are also not switched. Alternatively, it is conceivable for impedance matching to be effected in normal matching mode in such a way that one or more reactances (capacitance, inductance or transformation member) are mechanically altered so that another reactance value is established. In that case also, the switching state of the PIN diode switches is not altered in normal matching mode. The switching state of one or more PIN diode switches is altered only to switch back and forth between normal matching mode and protection mode.
In particular, it is provided that in normal matching mode transformation of the impedance of the load to an impedance range in which the generator is able to deliver power to the load takes place. With a view to low losses, that impedance transformation is regulated mechanically or is performed with a fixed setting. In a protection mode, that is, if there is risk that the HF generator will be damaged, only few PIN diode switches are used, and ideally only one PIN diode switch, to switch at least one reactance (inductance, capacitance or transformation member) in such a manner that the impedance then obtained is in a range that is not hazardous to the HF generator and the transmission circuitry. In that manner, HF generator and transmission circuitry are protected.
In some implementations, the impedance matching circuit has a plurality of PIN diode switches, wherein in normal matching mode, only some of the PIN diode switches are arranged in the power transmission path. It is thereby possible for individual circuit elements or alternatively a group of circuit elements to be connected into or disconnected from the HF path by means of PIN diode switches in order to transform an impermissible load impedance to the permissible range. This means that the impedance matching circuit is controlled in such a manner that the load impedance in the Smith diagram which is seen by the generator and which, owing to changes in the state of the load, has suddenly moved out of the impedance range that is safe for the generator is rapidly transformed back to that range and the generator and the transmission circuitry are thus protected.
The switch positions of the PIN diode switches and the connected reactances are each to be selected such that, in a state corresponding to a normal matching mode, the mechanically variable reactances of the impedance matching circuit or the fixed-setting reactances of the impedance matching circuit are able to undertake the impedance matching, wherein at most one or few PIN diode switch(es) may be involved in the transmission of the high-frequency power in order to keep the losses to a minimum. The term “involved” is to be understood in this context as meaning that the PIN diode switches are either switched on and a high-frequency current flows through them or that they are reverse-biased and they prevent a high-frequency current between two points. In that respect, the circuit variant in which in normal matching mode only a reverse-biased PIN diode switch is connected to the power transmission path offers advantages. In that case, only the additional depletion layer capacitance of the PIN diode has to be taken into consideration in the impedance matching circuit; losses due to the resistance of a switched-on PIN diode do not occur in normal matching mode.
To convert the set of reactances from the first reactance arrangement into the second reactance arrangement, at least one reactance may be connectable to or disconnectable from the first reactance arrangement via a PIN diode switch. As already mentioned, the reactances in the first reactance arrangement may include at least one reactance having a mechanically variable reactance value. It may be provided, in particular, that no mechanical variation of a reactance value takes place in a protection mode.
Furthermore, a plurality of PIN diode switches may be provided, the PIN diode switches being assigned respective switching states to selectively configure a set of reactances into different protective mode arrangements, including a first protective mode arrangement in an unignited plasma condition and a second protective mode arrangement on occurrence of a plasma arc. To convert the first reactance arrangement into another reactance arrangement, reactances may be switched in or cut out. This means that parallel capacitances, inductances or transformation members may be additionally connected or may be disconnected. It is also conceivable that, by closing, the PIN diode switches are used to shunt serial capacitances or that, by opening such a switch, shunting is cancelled. Furthermore, tapping of a series of capacitances, inductances or transformation members may be done via the PIN diode switches. The additional connection of one or more capacitances, inductances or transformation members via a PIN diode switch is also conceivable. In that case, additional inductances, capacitances or transformation members or the inductances, capacitances or transformation members or parts thereof used in normal matching mode may be affected by the switching operations of the PIN diode switches.
It is also possible for groups of circuit elements or entire networks to be switched in or cut out for the protection mode. For example, an LC member of the impedance matching circuit may be cut out or may be replaced or supplemented by another LC member.
In protection mode, correction reactances or also reactances or parts thereof that are active in normal matching mode may be switched in or cut out in order in that manner to achieve at least approximate impedance matching and protect the HF generator and other parts of the circuit.
The use of a mechanical impedance matching circuit comprising high-quality components, for example vacuum rotary capacitors and silver-plated air-core inductors, keeps down the losses in the impedance matching circuit in normal matching mode. In certain applications, for example in the case of gas lasers, a fixed-setting impedance matching circuit may also be sufficient for impedance matching in normal matching mode. Since the mechanical impedance matching circuit is able to react only very slowly to rapid impedance changes in the load, and the fixed-setting impedance matching circuit not at all, it is assisted in such cases by a limited number of rapidly connectable or disconnectable reactances.
At least one dc current source which has an associated overshoot device and which is associated with a PIN diode switch may be provided for switching on the PIN diode switch. That measure makes it possible to obtain rapid switching of the PIN diode to the conducting state. At the moment of being switched on, the PIN diode receives a higher current than in subsequent switched-on operation. The build-up of charge carriers in the diode is thus intensified at the instant of switching on.
Furthermore, a dc voltage source with associated overshoot device may be associated with at least one PIN diode switch to produce a reverse bias voltage. In that manner, rapid switching of the PIN diode to the non-conducting state can be obtained. In the switching off operation, initially a higher voltage is applied in the reverse direction than in subsequent reverse-biased operation. In that manner, depletion of charge carriers in the PIN diode is intensified at the instant of switching off.
At least one PIN diode switch may be connected to an inductor or an arrangement of inductors, so that, with an appropriate switch position of the PIN diode switch(es), inductors remain open at one end. A plurality of PIN diode switches may in this case be connected in series. If, therefore, an inductance is to be altered by a PIN diode switch, it is advantageous if inductor parts that are not used in a switch position or if a proportion of inductors magnetically coupled to one another are not short-circuited but are switched off at least at one end, that is to say, the choice of inductor tapping by a PIN diode switch or disconnection of the inductor from the circuit by a PIN diode switch, so that there are no short-circuited inductors or inductor parts in which currents could be induced and could cause losses there. Since high HF voltages may occur at the open end of an inductor in that case, a correspondingly large number of PIN diodes may be connected in series.
Measurement and evaluation circuitry may be provided for detection of the state of the load, especially the plasma load. Using the measurement and evaluation circuitry, undesired load impedances may be detected and appropriate counter-measures may be instituted. In particular, the PIN diode switches may be activated in such a manner that a first reactance arrangement of the normal matching mode is converted into another reactance arrangement in protection mode. The further processing of the acquired measuring signals is simplified if an analogue-to-digital converter is provided for digitizing acquired measuring signals.
In order to be able to alter the switching states of the PIN diode switches, it is advantageous if a control circuit is provided for controlling the PIN diode switches. In addition, a memory may be provided for storing parameters associated with the states of the load. In particular, it is possible for load states and associated reactions, i.e. switch positions of the PIN diode switches, to be stored in the memory. It is thus possible to react to different load states in a predefined manner.
The way in which an impedance matching circuit operates will be described hereinafter with reference to a plasma process. Before operation of the plasma chamber is commenced, the mechanical components of the impedance matching circuit may be adjusted in such a manner that it results in matching in the normal matching mode. To protect the HF generator from the high impedance of the plasma chamber containing the as yet unignited plasma, first a second reactance arrangement, which is different from that first reactance arrangement, is adjusted, that is to say, first at least one reactance is switched in or cut out by means of a PIN diode switch, in order to bring about approximate matching of the plasma chamber. As soon as the plasma has been ignited, the further reactance is switched to the position corresponding to the normal impedance matching mode, with the result that the first reactance arrangement is produced. The impedance matching circuit may then assume its normal regulating function, for example by means of the reactance values of individual reactances being adjusted by mechanical variation of the reactances. In that case, the correct reactance values for matching may already have been approximately obtained as a result of the described pre-adjustment.
If during operation an arc is detected, similarly at least one reactance is switched in or cut out by the associated PIN diode switch, with the result that another, third reactance arrangement is produced and the impedance of the plasma chamber as seen from the generator is again in the non-hazardous impedance range of the generator. After quenching of the arc, the PIN diode switches are returned to the switch position of the normal matching mode and the first reactance arrangement may again undertake the impedance matching. In protection mode, the mechanically variable reactances are preferably left unchanged so that, after switching of the PIN diode switches to the normal matching mode, they are immediately able to undertake matching in normal matching mode.
Another aspect of the invention features matching an impedance with an impedance matching circuit by transforming an impedance of a load with a set of reactances in a first reactance arrangement to an impedance within a range of a nominal impedance of an HF generator in a normal matching mode, and altering a switching state of a PIN diode switch from a first invariable switching state in the normal matching mode to a second switching state in a protection mode form a second reactance arrangement configured to transform an impedance of the load to prevent damage to the HF generator or to transmission circuitry arranged between the HF generator and a plasma load.
To form the second reactance arrangement from the first reactance arrangement, at least one reactance of the first reactance arrangement may be switched in or cut out of the first reactance arrangement via a PIN diode switch. In normal matching mode, at least one reactance value may be varied by mechanical variation of a reactance. In one variant of the method, it may be provided that, in a first protection mode, a second reactance arrangement is formed by switching at least one PIN diode switch and, in a second protection mode, a third reactance arrangement is formed by switching at least one PIN diode switch.
In order to be able to carry out good impedance matching as quickly as possible, pre-adjustment of the impedance matching circuit may be effected for a normal matching mode by adjusting at least one reactance provided for the normal matching mode and having a mechanically variable reactance value.
Losses may be reduced if (partial) inductances not used in a reactance arrangement are left open at one end.
Rapid alteration of the switching state of a PIN diode switch may be achieved if a PIN diode switch is switched on by applying a current in the forward direction with initial overshoot.
Rapid alteration of the switching state of a PIN diode may furthermore be effected if a PIN diode switch is reverse-biased by applying a reverse bias voltage with initial overshoot.
Particular advantages may be obtained if parameters for the normal matching mode and/or for a protection mode are ascertained by calibration of the impedance matching circuit and stored. The parameters so ascertained may later be used to carry out a pre-adjustment for the normal matching mode or to enable switching of the PIN diode switches for transformation to a non-hazardous impedance in the case of operating states that are normally hazardous to the HF generator.
The length of the connection line between HF generator and plasma load can be measured and taken into consideration in the selection of the switch positions of the PIN diode switches. The impedance matching can thereby be improved. In order to be able to decide whether a normal matching mode or a protection mode has to be carried out it is advantageous to ascertain quantities related to the state of the plasma load. For example, current or voltage, a phase angle, the reflected power or the like may be detected.
Further features and advantages will be apparent from the following detailed description of illustrative embodiments of the invention with reference to the Figures of the drawings, and from the claims. The features shown therein are not necessarily to be understood as being to scale and are illustrated in such a way as to enable significant elements to be made clear. In some implementations, the various features may be implemented individually or a plurality thereof may be implemented in any desired combination.
DESCRIPTION OF DRAWINGS
FIG. 1 shows an impedance matching circuit connected between an HF generator and a load.
FIG. 2 shows a driving arrangement for accelerating the charge carrier situation in the depletion layer of a PIN diode.
FIG. 3 a shows an example of circuitry for reducing the capacitance of a capacitor.
FIG. 3 b shows an example of circuitry for increasing the capacitance of a capacitor.
FIG. 4 a shows a series connection of two inductor parts.
FIG. 4 b shows an arrangement of PIN diode switches at a inductor.
FIG. 4 c shows a parallel connection of inductors for reducing inductance.
FIG. 5 shows a Smith diagram illustrating impedance matching in normal matching mode.
FIG. 6 shows a Smith diagram illustrating changing of the impedance when an arc occurs.
FIG. 7 shows a Smith diagram illustrating impedance matching in a protection mode.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
FIG. 1 shows an HF generator 10 which supplies a plasma load 11 with power. The plasma forms between the electrodes 12 , 13 in a plasma chamber 14 . An impedance matching circuit 15 is arranged between the HF generator 10 and the plasma load 11 . The impedance matching circuit 15 includes the reactances 16 - 20 , the reactances 16 , 19 being in the form of capacitors of invariable capacitance, the reactances 17 , 20 being in the form of capacitors of mechanically variable capacitance, and the reactance 18 being in the form of inductance. The motors 21 , 22 indicate that the reactances 17 , 20 are mechanically variable.
A measuring device 23 measures quantities that are related to the state of the load 11 . In that manner it is possible to detect whether the load is within a permissible range so that the load may be transformed to a nominal impedance or a nominal impedance range which is not hazardous to the HF generator 10 , or whether the load 11 has an impedance that cannot be transformed to the nominal impedance range. The evaluation is carried out by measurement and evaluation circuitry 24 having a memory 25 in which different states of the load 11 and correspondingly associated parameters are stored.
If, for example, the measurement and evaluation circuitry 24 , which may include an analogue-to-digital converter 26 , detects that transformation to the nominal impedance range is possible, a normal matching mode is established. This means that the PIN diode switches 27 , 28 are activated by a control circuit 29 in such a way that a first reactance arrangement is produced.
For example, the PIN diode switch 27 may be activated in such a way that it is closed and the PIN diode switch 28 may be activated in such a way that it is opened. This means that the first reactance arrangement includes all the reactances 16 - 20 . If, on the other hand, it is detected that transformation to the nominal impedance range is not possible, the control circuit 29 causes the PIN diode switches 27 , 28 to be activated in such a way that the PIN diode switch 27 is opened and the PIN diode switch 28 is closed. This means that the reactance 16 is no longer involved in an impedance transformation and the reactance 20 is shunted by the PIN diode switch 28 , with the result that it too is no longer involved in an impedance transformation. Accordingly, a second reactance arrangement, including the reactances 17 , 18 and 19 , is produced for a protection mode.
In protection mode, the reactance values of the mechanically variable reactances 17 , 20 are not intended to be altered. That ensures that, on changing from the second reactance arrangement to the first reactance arrangement, the reactances 17 , 20 still have values that enable the load impedance to be transformed to a nominal impedance range as quickly and as easily as possible. In normal matching mode, on the other hand, the reactances 17 , 20 are altered in such a way that the optimum possible impedance matching takes place. It should further be noted that the PIN diode switches 27 , 28 preferably do not change their switching states either in normal matching mode or in protection mode.
In FIG. 2 , a circuit for activating the PIN diode switch 40 is illustrated. It will first be explained how the PIN diode switch 40 is switched on. From the voltage source +UF a current passes through the resistor R 3 , the inductor L 1 and the switch T 1 formed by a transistor to earth. The inductance of the inductor L 1 may be higher than the inductance of the chokes RFCA and RFCK. In any event, the inductance of the inductor L 1 should be at least sufficiently great that, after opening of the switch T 1 , the self-induction of the inductor L 1 is able, as a result of a voltage overshoot, to rapidly build up a current counter to the self-inductions of the chokes RFCA and RFCK through the PIN diode 40 and the switch T 3 to earth. In that manner, the charge carriers are driven into the depletion layer of the PIN diode 40 . In the steady state, the dc current via the PIN diode 40 and the switch T 3 is limited by the resistor R 3 , and the combination of voltage source +UF with resistor R 3 may, when suitably dimensioned, be regarded as a current source.
Switching off of the PIN diode switch 40 is done by means of the switch T 1 short-circuiting to earth the current from the voltage source +UF via the resistor R 3 and the inductor L 1 and, at the same time, the anode of the PIN diode 40 via the choke RFCA. The switch T 2 applies the dc reverse bias voltage +UR via the choke RFCK to the cathode of the PIN diode 40 . The value of +UR is higher than is desired as reverse bias voltage in the steady state. It is brought to the correct magnitude by the voltage divider R 1 , R 2 . At the moment of switching on, however, R 1 is short-circuited through the capacitor CD, with the result that +UR is applied in full to the cathode of the PIN diode 40 and drives the charge carriers out of the depletion layer. The circuit on the left-hand side of the dashed line 43 accordingly constitutes a direct current source with overshoot device. The circuit on the right-hand side of the dashed line 44 , on the other hand, constitutes a dc voltage source with overshoot device.
FIG. 3 a shows a series connection, consisting of the capacitors Cx, Cy. A PIN diode switch 50 is arranged parallel to the capacitor Cy. If the PIN diode switch 50 is closed, the capacitor Cy is shunted, with the result that only the capacitor Cx is effective. If, on the other hand, the PIN diode switch 50 is opened, the capacitor Cy is not shunted, with the result that the series connection of the capacitors Cx, Cy is effective. It is thus possible to alter a reactance arrangement in an especially simple manner. For example, the circuit of FIG. 3 a could be used in an impedance matching circuit.
FIG. 3 b shows a parallel connection of the capacitors Cx, Cy, with a PIN diode switch 51 being arranged in series with the capacitor Cy. The capacitance of the overall arrangement can be altered by altering the switching state of the PIN diode switch 51 . If the PIN diode switch 51 is opened, only the capacitor Cx is effective, if the PIN diode 51 is closed, the parallel connection of Cx and Cy is effective.
FIG. 4 a shows a series connection of two inductors La, Lb, with a PIN diode switch 52 being arranged parallel to the inductor Lb. The point 53 between the inductors La, Lb may also be regarded as a tap. That tap can be short-circuited to the point 54 by closing the PIN diode switch 52 . In that manner the total inductance can be reduced. With this configuration, however, the current induced in the inductor Lb flows in a circle and produces losses in the inductor La.
To avoid that, an arrangement as shown in FIG. 4 b may be provided, wherein a total of three PIN diode switches 55 - 57 is provided. The PIN diode switch 55 is not closed simultaneously with the PIN diode switches 56 , 57 . If the PIN diode switch 55 is closed, the PIN diode switches 56 , 57 are opened, with the result that the end 58 of the inductor Lb is open. The series connection of two PIN diode switches 56 , 57 increases the withstand voltage at the end of the inductor Lb. A current flowing in a circle can be prevented by the arrangement of PIN diode switches 56 , 57 at both ends of the inductor Lb. In that manner, losses in the inductor La are also avoided.
FIG. 4 c shows a parallel connection of inductors La, Lb, wherein a PIN diode switch 59 is provided in series with the inductor Lb. If the PIN diode switch 59 is opened, the parallel connection is cancelled, with the result that only the inductor La is effective. The end of the inductor Lb is switched open by opening the PIN diode switch 59 . This means that the end is cut off from the rest of the circuit.
The circuit arrangements shown in FIGS. 4 b , 4 c , in particular, may be used in the impedance matching circuit.
FIG. 5 shows a Smith diagram 70 . At the point 101 , there is the impedance of the load in normal operation. By means of a first reactance of the first reactance arrangement transformation of the impedance to the point 102 occurs. From there, transformation of the impedance by a second reactance of the first reactance arrangement to point 103 occurs. There, a transformation to point 104 occurs by means of a third reactance of the first reactance arrangement. The circle 105 marks the nominal impedance range acceptable for the HF generator. This means that, by means of the first reactance arrangement, transformation of the load impedance takes place to a nominal impedance range that allows stable non-destructive operation of the HF generator.
FIG. 6 shows the situation obtained if, for example, an arc occurs. An arc reduces the impedance of the load, for example to a tenth of the normal operating impedance of the load, with the result that the impedance at point 201 is obtained. The reactances of the first reactance arrangement would carry out a transformation via the points 202 , 203 to the point 204 . That impedance at point 204 is clearly outside the circle 105 , and therefore transformation to an impedance that is outside the nominal impedance range takes place.
FIG. 7 shows the situation if impedance matching is carried out in protection mode by a second reactance arrangement. The load impedance at point 201 is transformed by means of reactances of the second reactance arrangement via the points 302 , 303 to the impedance at point 304 which is within the permissible impedance range 105 . The adapted impedance at point 304 is not ideal (it does not lie in the middle of the Smith diagram), but is clearly within the acceptable range 105 . The normal matching mode of the impedance matching circuit is suspended for the duration of the arc. After quenching of the arc, the PIN diodes switches are returned to their original switching state. In that manner, the first reactance arrangement is established again. That arrangement is immediately ideally matched and is able to carry out the impedance matching in normal matching mode. | In an impedance matching circuit selectively operable in a normal matching mode and a protection mode, the impedance matching circuit includes a set of reactances in a first reactance arrangement configured to transform an impedance of a load to an impedance within a range of a nominal impedance of an HF generator in the normal matching mode, and a PIN diode switch having a first invariable switching state in the normal matching mode and a second switchomg state that reconfigures the set of reactances into a second reactance arrangement in the protection mode, such that the second reactance arrangement is configured to transform the impedance of the load to prevent damage to the HF generator or to transmission circuitry arranged between the HF generator and the load. | 7 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Application No. 10/336,659 filed Jan. 12, 2003, which claims priority to U.S. application Ser. No.: 60/417,439, filed Oct. 12, 2002; this application is also a continuation-in-part of Application No. 11/081,827 filed Mar. 17, 2005, which is a divisional of Application No. 10/205,887 filed Jul. 26, 2002 (now U.S. Pat. No. 6,887,680, which is a continuation of Application No. 09/040,161 filed Mar. 17, 1998 (now U.S. Pat. No. 6,900,027), which is a continuation of Application No. 08/679,056 filed Jul. 12, 1996 (now U.S. Pat. No. 5,728,541). The entire disclosures of the prior applications are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention relates to methods for assessing efficacy of chemotherapeutic agents.
BACKGROUND
[0003] Cancer chemotherapy involves the use of cytotoxic drugs to destroy unwanted cells in patients. Treatment may consist of using one or more cytotoxic drugs, depending on the nature of the disease being treated. However, drug toxicity and drug resistance are significant barriers effective chemotherapy.
[0004] Toxicity from chemotherapeutic agents produces side effects ranging from mild trauma to death. Moreover, repeated exposure to chemotherapeutic drugs is itself often fatal. As chemotherapeutic drugs are carried in the blood, they are taken up by proliferating cells, including normal cells. Tissues with high growth rates such as bone marrow and epithelial tissues, including the gastrointestinal tract, are normally most susceptible to toxic side effects. Some drugs have additional toxic effects on other tissues, such as the urinary tract, myocardium, or pancreas. Chemotherapeutic agents may cause direct injury to the heart, either acutely, in the form of myocardial tissue injury or dysrhythmias, or in a delayed or chronic fashion associated with congestive heart failure.
[0005] Target cells, such as malignant or diseased cells, may be intrinsically resistant to chemotherapeutic drugs or they may acquire resistance as a result of exposure. A target cell may be genetically predisposed to resistance to particular chemotherapeutics. Alternatively, the cell may not have receptors or activating enzymes for the drug or may not be reliant on the biochemical process with which the drug interferes. Additionally, individuals may be inherently resistant to a drug due to altered disposition of the drug in organs other than the tumor. These mechanisms include, but are not limited to, rapid metabolism to inactive species, failure to metabolize to an active species of drug, and rapid clearance or sequestration. Many of these aspects are encoded genetically by normal polymorphisms in metabolic genes that act primarily, but not exclusively, in the liver and gastrointestinal tract and the kidneys.
[0006] Acquired resistance also may develop after cells have been exposed to a drug or to similar classes of drugs. One example of acquired drug resistance is the multiple drug resistance phenotype. Multiple drug resistance is a phenomenon of cross-resistance of cells to a variety of chemotherapeutic agents which are not structurally or functionally related. This phenomenon is typically mediated by p-glycoprotein, a cell membrane pump that is present normally on the surface of some epithelial cells. The protein actively removes drug from the cell, making it resistant to drugs that are substrates for the cell membrane pump.
[0007] A critical issue in cancer chemotherapy is the ability to select drugs that not only affect cancer cell phenotype in cell culture assays, but are also not subject to resistance whether in the tumor or intrinsic to the patient. The present invention addresses that issue.
SUMMARY OF THE INVENTION
[0008] The invention provides methods for accurately predicting efficacy of chemotherapeutic agents. Methods of the invention increase the positive predictive value of chemosensitivity assays by assessing both the ability of a chemotherapeutic to affect tumor cells phenotype and the genetic propensity of the patient for resistance to the chemotherapeutic. Results obtained using methods of the invention provide insight into the in vivo effectiveness of a therapeutic, and lead to more effective, individualized, chemotherapeutic choices.
[0009] According to the invention, a phenotype assay screens a therapeutic candidate for the ability to affect the phenotype of tumor cells in culture. A therapeutic candidate that produces the desired phenotypic effect (e.g., cell death, decreased motility, changes in cellular adhesion, angiogenesis, or gene expression, among others) then is screened against genetic properties of cells of the patient which make resistance to the therapeutic candidate likely or possible. A therapeutic candidate that has a desired phenotypic effect on patient tumor cells and that does not appear to be subject to genetic-based resistance is selected for use. As a result of combining phenotypic and genetic data, use of the invention increases the likelihood that a therapeutic candidate, chosen on the basis of its ability to affect cellular phenotype, will be effective when administered to patients.
[0010] Accordingly, the invention provides methods for assessing efficacy of chemotherapeutic agents comprising exposing cells to a chemotherapeutic agent, conducting an assay to determine whether the chemotherapeutic agent affects tumor cell phenotype, and identifying genetic characteristics of cells of the patient (which may or may not be tumor cells) that indicate a propensity for resistance to the chemotherapeutic agent.
[0011] In a preferred embodiment, a phenotypic assay for use in the invention comprises obtaining a tumor explant from a patient, culturing portions of the explant, growing a monolayer of relevant cells from the explant, exposing the monolayer to a drug candidate, and assessing the ability of the drug candidate to alter tumor cell phenotype. A preferred phenotypic assay is disclosed in U.S. Pat. No. 5,728,541, and in co-owned, co-pending U.S. application Ser. No. 10/208,480, both of which are incorporated by reference herein.
[0012] Genotype analysis according to the invention is accomplished by any known method. A preferred method comprises comparing the genotype, or portion thereof, of cells obtained from the patient with genotypes known to be associated with drug resistance generally, or specifically with respect to a therapeutic candidate being evaluated. For example, the existence in patient cells of a polymorphic variant that is known or suspected to confer resistance to a therapeutic candidate would screen that candidate out as a potential therapeutic against those cells. Genetic characteristics of patient cells are determined by methods known in the art (e.g., sequencing, polymorphisms) as set forth below. The impact of a patient's genotype upon drug resistance may be determined by reference to genetic databases or libraries that catalog known mutations or polymorphisms related to resistance.
[0013] The present invention also provides methods for selecting a chemotherapeutic agent for treating a patient based on results obtained from the phenotypic and genotypic assays. In a preferred embodiment, the present invention allows for the assessment of whether a chemotherapeutic agent will be effective in treating a cancer when administered to a patient. According to the invention, chemotherapeutic agents or combinations of chemotherapeutic agents are selected for treatment where an effect on cellular phenotype is observed and characteristics of genetic-based resistance are not observed.
[0014] Methods of the invention are useful in drug or chemotherapeutic agent screening to provide information indicative of the in vivo reactivity of the cells, and thus the specific efficacy as to a particular patient. Methods of the invention are also useful to screen new drug candidates for therapeutic efficacy and to provide a basis for categorizing drugs with respect to the tumor types against which they will work best.
[0015] A phenotypic assay according to the invention is conducted on cells obtained from a tumor explant from a patient. Genotypic assays of the invention are performed on genetic data obtained from patient cells, regardless of their source. Thus, a genotypic assay can be performed on somatic cells obtained from the patient or on cells from the same tumor that is evaluated in the phenotypic assay. Assays of the invention can be performed on an individualized basis or on a pool of samples obtained from multiple individual patients. If assays are conducted on pooled samples, the phenotypic characteristics of the pool of samples are determined followed by individualized genotypic assays on specific patients. This allows multiplexing of the phenotypic portion of the assay.
DETAILED DESCRIPTION OF THE INVENTION
[0016] This invention provides methods for assessing efficacy of chemotherapeutic agents. Specifically, the invention provides methods for assessing the efficacy of chemotherapeutic agents based on phenotypic changes observed in tumor cells obtained from a patient and genetic characteristics of the patient that indicate general or specific chemotherapeutic resistance. In one aspect of the invention, efficacy of a chemotherapeutic agent is assessed based upon the results of the phenotypic and genotypic assays. In another aspect of the invention, chemotherapeutic agents are selected for treating a patient based on the results of the phenotypic and genotypic assays.
[0017] The present invention is also useful for screening of therapeutic agents against other diseases, including but not limited to, hyperproliferative diseases, such as psoriasis. In addition, the screening of agents that retard cell growth (anti-cancer, anti-proliferative), including agents that enhance or subdue intracellular biochemical functions, are evaluated using methods of the present invention. For example, the effects of therapeutics on the enzymatic processes, neurotransmitters, and biochemical pathways are screened using methods of the invention. Methods of the invention can be practiced on any type of cell obtained from a patient, including, but not limited to, normal somatic cells, malignant cells, abnormal proliferating cells, and other diseased cells. Cells are obtained from any patient sample, including, but not limited to, tumors, blood samples and buccal smears. The skilled artisan recognizes that methods of the invention can be practiced using a variety of different samples.
[0018] In one step of the invention, a phenotype assay is employed to assess sensitivity and resistance to chemotherapeutic agents. The phenotypic assay is performed in vitro using cultured cells. The phenotype assay allows for identification and separation of target cells from other cells found in a tissue sample, as well as direct measurement and monitoring of target cells in response to chemotherapeutic treatment. Direct measurements and monitoring of live cells are performed using known methods in the art including, for example, the measuring of doubling rate, fraction proliferative assays, monitoring of cytostasis, cell death, cell adhesion, gene expression, angiogenesis, cell motility, and others. Direct measurements also include known assays, such as those directed to measurement and monitoring of apoptosis, senescence, and necrosis.
[0019] In another step of the invention, a genotype assay is performed to determine whether cells from a patient comprise a genetic characteristic associated with resistance to the chemotherapeutic agents. Genotype assays reveal latent resistance to chemotherapeutic agents not observed by phenotypic assays. Genotypic assays may measure characteristics, such as metabolism, toxic effects, absorption of a therapeutic candidate.
[0020] In one embodiment of the invention, the phenotypic assay is performed using cell culture monolayers prepared from tumor cells. In a preferred embodiment, monolayers are cultured from cohesive multicellular particulates generated from a tumor biopsy. Explants of tumor tissue sample are prepared non-enzymatically, for initial tissue culture monolayer preparation. The multicellular tissue explant is removed from the culture growth medium at a predetermined time to both allow for the growth of target cells and prevent substantial growth of non-target cells such as fibroblasts or stromal cells.
[0021] By way of example, in one embodiment of the invention, a cell culture monolayer is prepared in accordance with the invention using the following procedure. A biopsy of non-necrotic, non-contaminated tissue is obtained from a patient by any suitable biopsy or surgical procedure known in the art. In a preferred embodiment, the tissue sample is tumor tissue. The size of the biopsy sample is not central to the methods provided herein, but a sample is preferably about 5 to 500 mg, and more preferably about 100 mg. Biopsy sample preparation generally proceeds under sterile conditions. Cohesive multicellular particulates (explants) are prepared from the tissue sample by enzymatic digestion or mechanical. fragmentation. Ideally, mechanical fragmentation of the explant occurs in a medium substantially free of enzymes that are capable of digesting the explant. For example, the tissue sample may be minced with sterile scissors to prepare the explants. In a particularly preferred embodiment, the tissue sample is systematically minced by using two sterile scalpels in a scissor-like motion, or mechanically equivalent manual or automated opposing incisor blades. This cross-cutting motion creates smooth cut edges on the resulting tissue multicellular particulates. After the tissue sample has been minced, the particles are plated in culture flasks (for example, 9 explants per T-25 flask or 20 particulates per T-75 flask). The explants are preferably evenly distributed across the bottom surface of the flask, followed by initial inversion for about 10-15 minutes. The flask is then placed in a non-inverted position in a 37° C. CO 2 incubator for about 5-10 minutes. In another embodiment in which the tissue sample comprises brain cells, the flasks are placed in a 35° C., non-CO 2 incubator. Flasks are checked regularly for growth and contamination.
[0022] The multicellular explant is removed from the cell culture at a predetermined time, as described below. Over a period of a few weeks a monolayer is produced. With respect to the culturing of tumor cells, it is believed (without any intention of being bound by the theory) that tumor cells grow out from the multicellular explant prior to contaminating stromal cells. Therefore, by initially maintaining the tissue cells within the explant and removing the explant at a predetermined time, growth of the tumor cells (as opposed to stromal cells) into a monolayer is facilitated. The use of the above procedure to form a cell culture monolayer maximizes the growth of tumor cells from the tissue sample, and thus optimizes the phenotypic and genotypic assays.
[0023] Once a primary culture and its derived secondary monolayer tissue culture has been initiated, the growth of the cells is monitored to oversee growth of the monolayer and ascertain the time to initiate the phenotypic assay. Prior to the phenotypic assay, monitoring of the growth of cells may be conducted by visual monitoring of the flasks on a periodic basis, without killing or staining the cells and without removing any cells from the culture flask. Data from periodic counting or measuring is then used to determine growth rates or cell motility, respectively.
[0024] Phenotypic assays are performed on cultured cells using a chemotherapeutic drug response assay with clinically relevant dose concentrations and exposure times. One embodiment of the present invention contemplates a phenotypic assay that assesses whether chemotherapeutic agents effect cell growth. Monolayer growth rate is monitored using, for example, a phase-contrast inverted microscope. In one embodiment, culture flasks are incubated in a (5% CO 2 ) incubator at about 37° C. The flask is placed under the phase-contrast inverted microscope, and ten fields (areas on a grid inherent to the flask) are examined using a 10× objective. In general, the ten fields should be non-contiguous, or significantly removed from one another, so that the ten fields are a representative sampling of the whole flask. Percentage cell occupancy for each field examined is noted, and averaging of these percentages then provides an estimate of overall percent confluency in the cell culture. When patient samples have been divided between two more flasks, an average cell count for the total patient sample should be calculated. The calculated average percent confluency should be entered into a process log to enable compilation of data--and plotting of growth curves—over time. Alternatively, confluency is judged independently for each flask. Monolayer cultures may be photographed to document cell morphology and culture growth patterns. The applicable formula is:
Percent confluency = estimate of the area occupied by cells total area in an observed field
As an example, therefore, if the estimate of area occupied by the cells is 30% and the total area of the field is 100%, percent confluency is 30/100, or 30%.
[0025] Following initial culturing of the multicellular tissue explant, the tissue explant is removed from the growth medium at a predetermined time. In one embodiment, the explant is removed from the growth medium prior to the emergence of a substantial number of stromal cells from the explant. Alternatively, the explant may be removed according to the percent confluency of the cell culture. In one embodiment of the invention, the explant is removed at about 10 to about 50 percent confluency. In a preferred embodiment of the invention, the explant is removed at about 15 to about 25 percent confluency. In a particularly preferred embodiment, the explant is removed at about 20 percent confluency. By removing the explant in either of the above manners, a cell culture monolayer predominantly composed of target cells (e.g., tumor cells) is produced. In turn, a substantial number of non-target cells, such as fibroblasts or other stromal cells, fail to grow within the culture. Ultimately, this method of culturing a multicellular tissue explant and subsequently removing the explant at a predetermined time allows for increased efficiency in both the preparation of cell cultures and subsequent phenotypic and genotypic assays for assessing efficacy of chemotherapeutic agents.
[0026] In another embodiment, a phenotypic assay assesses whether chemotherapeutic agents effect cell motility. Methods for measuring cell motility are known by persons skilled in the art. Generally, these methods monitor and record the changes in cell position over time. Examples of such methods include, but are not limited to, video microscopy, optical motility scanning (for example, see U.S. Pat. No. 6,238,874, the disclosure of which is incorporated by reference herein) and impedance assays. In a preferred embodiment, cell motility assays are carried out using monolayer cultures of malignant cells as described herein.
[0027] Cell culture methods of the invention permit the expansion of a population of proliferating cells in a mixed population of abnormal proliferating cells and other (normal) cells. The mixed population of cells typically is a biopsy or sample from a solid tumor. A tissue sample from the patient is harvested, cultured and analyzed for genetic indicia of resistance to chemotherapeutics. Subcultures of the cells produced by the culture methods described above may be separately exposed to a plurality of treatments and/or therapeutic agents for the purpose of objectively identifying the best treatment for the patient. By way of example, procedures for culturing the malignant cells and determining a phenotypic to a chemotherapeutic agent may be performed in the following manner. First, a specimen is finely minced and tumor fragments are plated into tissue culture. The cells are then exposed to growth medium, such as a tumor-type defined media with serum. The cells are trypsinized, preferably, but not necessarily, when greater than 150,000 cells grown out from tumor fragment. The cells are preferably plated into a Terasaki plate at 350 cells per well. The cells are analyzed to verify that a majority of cells are tumor epithelial cells. Non-adherent cells are removed from the wells. The cells are treated with 6 concentrations and 2 control lanes of chemotherapeutic agent or agents for preferably 2 to 4 hours. The chemotheraputic agents are removed by washing. The cells are incubated for preferably 3 days. The living cells are counted to calculate the kill dose that reduces by 40% the number of cells per well from control wells.
[0028] The culture techniques of the present invention result in a monolayer of cells that express cellular markers, secreted factors and tumor antigens in a manner representative of their expression in vivo. Specific method innovations such as tissue sample preparation techniques render this method practically, as well as theoretically, useful.
[0029] According to the present invention, cells from a patient are analyzed for genetic characteristics (abnormalities) specific to a patient. Genetic characteristic of a cell or cell population can be analyzed alone or in combination with other characteristics. Genetic characteristics of the invention can be, without limitation, a genetic polymorphism or a mutation, such as an insertion, inversion, deletion, or substitution. In one embodiment, nucleic acids are isolated from cells of a patient and analyzed to identify genotypic characteristics of the cells. The isolated nucleic acid is DNA or RNA. The nucleic acid, preferably, is analyzed in a microarray for DNA-encoded polymorphisms in the coding or control regions of the gene. In another embodiment, the nucleic acid is analyzed in a microarray for aberrant expression of one or more genes. In this embodiment, the microarray contains nucleic acids that are characteristic of known malignancies, as well as nucleic acids, that are not correlated with known malignancies so that previously unknown relationships between gene expression and a proliferative disease or condition may be identified.
[0030] A preferred method of the invention comprises comparing the genotype, or portion thereof, of cells from a patient with genotypes known to be associated with drug resistance generally, or specifically with respect to a therapeutic candidate being evaluated. For example, the existence in patient cells of a polymorphic variant that is known or suspected to confer resistance to a therapeutic candidate would screen that candidate out as a potential therapeutic against those cells.
[0031] Methods for isolating and analyzing nucleic acids derived from the cells are known in the art. The presence of known proliferation markers, such as the aberrant expression of one or more genes, the epidermal growth factor receptor (EGFR) cyclin D1, p16cyclin-kinase inhibitor, retinoblastoma (Rb), transforming Growth Factor β (TGFβ) receptor/smad, MDM2 or p53 genes, may be determined by, for example, northern blotting or quantitative polymerase chain reaction (PCR) methods (i.e., RT-PCR).
[0032] In one embodiment of the present invention, mRNA (polyA + mRNA) is isolated and labeled cDNA is prepared therefrom. The labeled cDNA is prepared by synthesizing a first strand cDNA using an oligo-dT primer, reverse transcriptase and labeled deoxynucleotides, such as, Cy5-dUTP, commercially available from Amersham Pharmacia Biotech. Radio-labeled nucleotides also can be used to prepare cDNA probes. The labeled cDNA is hybridized to the microarray under sufficiently stringent conditions to ensure specificity of hybridization of the labeled CDNA to the array DNA.
[0033] In another embodiment of the invention, the labeled array is visualized. Visualization of the array may be conducted in a variety of ways. For instance, when the reading of the microarray is automated and the labeled DNA is labeled with a fluorescent nucleotide, the intensity of fluorescence for each discreet DNA of the microarray can be measured automatically by a robotic device that includes a light source capable of inducing fluorescence of the labeled cDNA and a spectrophotometer for reading the intensity of the fluorescence for each discreet location in the microarray. The intensity of the fluorescence for each DNA sample in the microarray typically is directly proportional to the quantity of the corresponding species of mRNA in the cells from which the mRNA is isolated. It is possible to label cDNA from two cell types (i.e., normal and diseased proliferating cells) and hybridize equivalent amounts of both probe populations to a single microarray to identify differences in RNA expression for both normal and diseased proliferating cells. Tools for automating preparation and analysis of microarray assays, such as robotic microarrayers and readers, are available commercially from companies such as Gene Logic and Nanogen and are under development by the NHGRI. The automation of the microarray analytical process is desirable and, for all practical purposes necessary, due to the huge number and small size of discreet sites on the microarray that must be analyzed.
[0034] In a further embodiment, DNA microarrays are used in combination with the cell culturing method of the present invention due to the increased sensitivity of mRNA quantification protocols when a substantially pure population of cells are used. For their ease of use and their ability to generate large amounts of data, microarrays are preferred, when practicable. However, certain other or additional qualitative assays may be preferred in order to identify certain markers.
[0035] In another embodiment, the presence of, or absence of, specific RNA or DNA species are identified by PCR procedures. Known genetic polymorphisms, translocations, or insertions (i.e., retroviral insertions or the insertion of mobile elements, such as transposons) often can be identified by conducting PCR reactions with DNA isolated from cells cultured by the methods of the present invention. Where the sequence anomalies are located in exons, the genetic polymorphisms may be identified by conducting a PCR reaction using a cDNA template. Aberrant splicing of RNA precursors also may be identified by conducting a PCR reaction using a cDNA template. An expressed translocated sequence may be identified in a microarray assay, such as the Affymetrix p53 assay.
[0036] In one embodiment, small or single nucleotide substitutions are identified by the direct sequencing of a given gene by the use of gene-specific oligonucleotides as sequencing primers. In a further embodiment, single nucleotide mutations are identified through the use of allelic discrimination molecular beacon probes, such as those described in Tyagi, S. and Kromer, F. R. (1996) Nature Biotech. 14:303-308 and in Tyagi, S. et al., (1998) Nature Biotech. 16:49-53, the disclosures of each of which are incorporated by reference herein.
[0037] Genotypic analysis may be based on experimentation or experience. Sources for such empirical data made be obtained from, but not limited to clinical records and/or animal tumor transplant studies. Genetic characteristics found in the patient cells can be compared to a database containing known tumor genotypes and their respective resistance to chemotherapeutic agents. In a preferred embodiment, a database containing genotypes and their respective drug resistance profile is used to compare genotypic characteristics of the target cells to resistance to chemotherapeutic agents in vivo. Computer algorithms are useful for carrying out pattern matching routines in complex systems, such as genetic data-mining. A linear regression algorithm, for example, can be utilized to analyze a database and identify the genotype most closely matching the genetic characteristics in the patient cells. In one embodiment, a comparative analysis of genotypes is performed using a known linear regression algorithm.
[0038] According to the invention, genotypic characteristics of patient cells are analyzed to establish whether such characteristics are associated with resistance to chemotherapeutic agents in vivo. While the above-mentioned genotypic assays are useful in the analysis of nucleic acids derived from cells produced by the culture methods embodied in the present invention, numerous additional methods are known in the general fields of molecular biology and molecular diagnostics that may be used in place of the above-referenced methods. Information obtained from genotypic assays is analyzed to determine efficacy of chemotherapeutic agents.
[0039] In a further embodiment of the invention, data obtained by practicing the methods of the invention, including phenotypic, genotypic and patient outcome information, is stored in databases. The contents of these databases include, but are not limited to, observed in vitro phenotypes (disease factors) and genotypes (host factors). By applying analytical techniques to the stored information, predictions of chemotherapeutic efficacy can be made. Methods of the invention allow for the skilled practitioner to accurately select an effective course of chemotherapy for a patients, thus reducing the risk of treatment-related trauma and resistance.
[0040] In one aspect of the invention, a course of chemotherapy is selected based on results obtained from the phenotypic and genotypic assays. The present invention allows for the assessment of the likelihood of whether chemotherapeutic agents will be effective in treating a malignancy in a patient. A phenotypic assay in combination with a genotypic assay operates to minimize the risk of administering to a patient a chemotherapeutic agent or combinations of chemotherapeutic agents to which the tumor is resistant. In one aspect of the invention, chemotherapeutic agents or combinations of chemotherapeutic agents are selected for treatment where an effect on cellular phenotype is observed and the genotypic characteristics associated with resistance are not observed.
[0041] Chemotherapeutic agents that effect cellular phenotype are potential candidates for use in the patient. Known procedures that screen for chemotherapeutic agents are time-consuming and expensive. In one embodiment of the invention, chemotherapeutic agents that effect cellular phenotype and lack genetic changes associated with drug resistance are administered to the patient. In a further embodiment, genotypic characteristics observed in the genetic assay undergo a comparative analysis to determine if such characteristics are associated with drug resistance. In another embodiment, the phenotypic and genotypic assays are performed in succession, thereby narrowing the scope of the genotypic comparative analysis, and reducing labor costs and associated expenses. In one aspect of the invention, when it is determined that a chemotherapeutic agent effects cellular phenotype and is not associated with resistance to cells having the genotypic change, a patient is treated with the chemotherapeutic agent.
[0042] The following examples provide further details of methods according to the invention. For purposes of exemplification, the following examples provide details of the use of methods of the present invention in cancer treatment. Accordingly, while exemplified in the following manner, the invention is not so limited and the skilled artisan will appreciate its wide range of application upon consideration thereof
EXAMPLE 1
[0043] A patient was diagnosed with breast cancer and chemotherapeutic treatment was prescribed by the treating physician. A tumor biopsy of approximately 100 mg of non-necrotic, non-contaminated tissue was harvested from the patient by surgical biopsy and transferred to a laboratory in a standard shipping container. Biopsy sample preparation proceeded as follows. Reagent grade ethanol was used to wipe down the surface of a Laminar flow hood. The tumor was then removed, under sterile conditions, from its shipping container, and cut into quarters with a sterile scalpel. Using sterile forceps, each undivided tissue quarter was then placed in 3 ml sterile growth medium (Standard F-10 medium containing 17% calf serum and a standard amount of Penicillin and Streptomycin) and minced by using two sterile scalpels in a scissor-like motion. After each tumor quarter was minced, the particles were plated in culture flasks using sterile pasteur pipettes (9 explants per T-25 or 20 particulates per T-75 flask). Each flask was then labeled with the patient's code and the date of explantation. The explants were evenly distributed across the bottom surface of the flask, with initial inverted incubation in a 37° C incubator for 5-10 minutes, followed by addition of about 5-10 ml sterile growth medium and further incubation in the normal, non-inverted position. Flasks were placed in a 35° C., non-CO 2 incubator. Flasks were checked daily for growth and contamination as the explants grew out into a cell monolayer.
[0044] Following initiation of prime cell culture of the tumor specimen, cells were removed from the monolayers grown in the flasks for centrifugation into standard size cell pellets. Each cell pellet was then suspended in 5 ml of the above-described medium and was mixed in a conical tube with a vortex for 6 to 10 seconds, followed by manual rocking back and forth 10 times. A 36 ml droplet from the center of each tube was then pipetted into one well of a 96-well microtiter plate together with an equal amount of trypan blue, plus stirring. The resulting admixture was then divided between two hemocytometer quadrants for examination using a standard light microscope. Cells were counted in two out of four hemocytometer quadrants, under 10× magnification—only those cells which did not take up the trypan blue dye were counted. This process was repeated for the second counting chamber. An average cell count per chamber was calculated, and the optimum concentration of cells in the medium was determined.
[0045] Accommodating the above calculations, additional cell aliquots from the 4 monolayers were separately suspended in growth medium via vortex and rocking and were loaded into a Terasaki dispenser adapted to a 60-well plate. Aliquots of the prepared cell suspension were delivered into the microtiter plates using Terasaki dispenser techniques. Cells were plated into 60-well microtiter plates at a concentration of 100 cells per well.
[0046] Twenty-four hours post-plating, the chemotherapeutic agent paclitaxel sold under the trademark TAXOL (Bristol-Myers Squibb Company) was applied to the wells in the microtiter plates. Three treatment rows in the plates (Rows 2, 3, and 4) were designed to have escalating paclitaxel doses (1.0, 5.0, and 25 μM). Row 5 served as a control. The paclitaxel exposure time was two hours. The cells were allowed to incubate for another 72 hours so that inhibition of cell proliferation can be observed. During this period, the growth inhibiting effect of paclitaxel was monitored by observing the percent of confluency of the cells. For each microtiter well, the percent of confluency of cultured cells was plotted as a finction of time.
[0047] Since paclitaxel affected growth rate of the cultured cells, cells from the patient were subjected to genotypic analysis. DNA was isolated from cells of the patient and analyzed for single nucleotide genetic polymorphisms. Known genetic polymorphisms were identified in the DNA by conducting PCR reactions and sequencing or SNP detection by hybridizations of a region of interest in the DNA. The DNA region of interest from the patient cells was compared to corresponding regions from known genetic banks and libraries (for example, GENBANK).
[0048] The phenotypic and genotypic assays were used in combination to determine that paclitaxel was an efficacious course of treatment for the patient. As a result, paclitaxel was administered to the patient.
EXAMPLE 2
[0049] A patient was diagnosed with lung cancer and chemotherapeutic treatment was prescribed by the treating physician. A tumor biopsy of approximately 100 mg of non-necrotic, non-contaminated tissue was harvested from the patient by surgical biopsy and transferred to a laboratory in a standard shipping container. The biopsy sample was prepared as described in Example 1. Twenty-four hours post-plating, the chemotherapeutic agent carboplatin sold under the trademark PARAPLATIN (Bristol-Myers Squibb Company) was applied to the wells in the microtiter plates. The first three treatment rows in the plates (Rows 2, 3, and 4) were designed to have escalating carboplatin doses (50, 200, and 1000 μM). Row 5 serves as a control. The carboplatin exposure time was two hours. The cells were allowed to incubate for another 72 hours so that inhibition of cell motility can be observed.
[0050] Cell motility was measured by calculating the distance a cell travels over time. Cells were monitored using a digital video-camera mounted on a phase-contrast light microscope. To maintain the growth medium at 35° C., the microscope was fitted with a heated slide stage. After the cultured cells were incubated with carboplatin, cell migration was recorded under appropriate magnification (usually between 40× and 200×). During this period, the motility inhibiting effect of carboplatin was documented by plotting the distance cells travel as a function of time. The distance cells travel was a determined using digital imaging techniques known in the art.
[0051] Since carboplatin affected cell motility in the tumor cells, the cells were subjected to genotypic analysis by comparing DNA from the cultured cells to known genetic banks and libraries. Known genetic polymorphisms were identified in the cultured cells by conducting PCR reactions and sequencing a region of interest in DNA isolated from the cultured cells. The DNA region of interest from the cultured cells was compared to corresponding regions from known genetic banks and libraries (for example, GENBANK).
[0052] Genetic characteristcs observed in the genotypic assay were compared to a database of genetic characteristics that were known to be associated with resistance to carboplatin. The phenotypic and genotypic assays were used in combination to determine that carboplatin was an efficacious course of treatment for the patient. As a result, carboplatin was administered to the patient.
[0053] While the invention has been shown and described with reference. to specific preferred embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the following claims. | Methods are provided for accurately predicting efficacy of chemotherapeutic agents. Methods of the invention increase the positive predictive value of chemosensitivity assays by assessing both the ability of a chemotherapeutic to destroy cells and the genetic propensity of those cells for resistance. Results obtained using methods of the invention provide insight into the in vivo effectiveness of a therapeutic, and lead to more effective chemotherapeutic treatment. | 2 |
This is a continuation in part of our co-pending application Ser. No. 625,565, filed Oct. 24, 1975.
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
This invention relates to fuel systems and vaporizing devices therein for internal combustion engines, and more particularly fuel gas generators.
2. DESCRIPTION OF THE PRIOR ART
Fuel systems for internal combustion engines have generally used carburetors in which gasoline is sprayed into a stream of air and divided into a series of fine droplets approaching vaporization and conveyed to the point of combustion. Only those molecules at the surface of the gasoline droplets are in a position to react with another species and incomplete combustion results because the very short time allowed is insufficient for more than a little vaporization of the fuel to occur. The prior art engines therefore exhaust large quantities of unburned hydrocarbons, carbon monoxide and oxides of nitrogen all of which are undesirable atmospheric pollutants. Several attempts to improve vaporization may be seen in U.S. Pats. Nos. 1,110,482; 2,585,171; 2,285,905 and 2,272,341.
This invention simultaneously vaporizes the liquid fuel and water at very high temperatures so that fuel mixture in its heated pressurized gaseous state achieves practically complete combustion in the internal combustion engine due to the spacing of the molecules resulting from the heat and the superheated steam.
SUMMARY OF THE INVENTION
A hot fuel gas generator having a novel high temperature and pressure controlled heated vaporizer is disclosed in which gasoline and water are simultaneously vaporized to produce a hot gaseous fuel under pressure and regulated as to temperature volume and flow is in direct communication with the inlet manifold of the engine. The usual carburetor adds fuel for starting only and continuously controls the combustion air and regulates the same to provide throttle control. The partial vaccum resulting from the operation of the internal combustion engine moves the combustion air with the proper quantity of the hot gaseous fuel from the generator to the areas of combustion in the engine. The complete vaporization of the liquid fuel and the water is caused by high temperature heat from an external source under controlled pressure and volume conditions. Gasoline or order fuel in a ratio of 80% -90% to water 10% -20% makes a highly satisfactory hot gaseous fuel.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional side elevation of the hot fuel gas generator;
FIG. 2 is a diagrammatic illustration of a fuel system for an internal combustion engine and incorporating the generator of FIG. 1, and
FIG. 3 is a cross sectional side view of a fuel introducing fitting used in the fuel system of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
By referring to the drawings and FIG. 1 in particular it will be seen that the hot fuel gas generator comprises a multi-chambered pressure vessel in the form of a hollow body member generally indicated by the numeral 10, the lowermost portion of which has a heat exchange chamber 11 therein, a separating partition 12 and a flash vaporization chamber 13 immediately thereabove. A thin walled partition 14 apertured in an annular pattern as at 15 divides the flash vaporization chamber into upper and lower parts and forms a deflector against which gasoline or another fuel and water are directed as hereinafter described. The upper portion of the multi-chambered pressure vessel 10 forms a vapor chamber 16 directly adjacent the flash vaporization chamber 13 and its uppermost part and a manifold pressure responsive chamber17 is positioned immediately thereabove. A partition 18 separates the chambers 13 and 16 and has an inwardly and downwardly tapered opening 19 therethrough in which a first tapered valve element 20 is operatively positioned and arranged so that it will move upwardly and thereby partially open the opening 19 upon an increase of pressure in the chamber 13 as hereinafter described. Twelve PSI pressure is normal.
A partition 21 separates the chambers 16 and 17 and has an opening therethrough in which a tapered valve seat member 22 defining a tapered bore is positioned, the bore tapering upwardly and inwardly toward the manifold pressure responsive chamber 17. An inverted tapered valve element 23 is positioned in the tapered valve seat member 22 and is carried by a stem 24 which extends upwardly to a point of attachment 24 in the center of a diaphragm 25. A coil spring 26 is positioned around the stem 24 and between the diaphragm 25 and the uppermost portion of the tapered valve seat member 22 and normally urges the diaphragm 25 upwardly toward a closure 27 which forms the top of the manifold pressure responsive chamber 17. Elongated fasteners 28 join the closure 27 and the upper parts of the multi-chambered pressure vessel 10 as will be understood by those skilled in the art and fasteners 29 secure a bottom closure 30 to the lower end thereof to form the heat exchange chamber 11.
Still referring to FIG. 1 of the drawings, it will be seen that the uppermost end of the first tapered valve element 20 is joined by a link 31 to one end of a balance bar 32 which is pivoted to a support 33 by a pivot 34. A second coil spring 35 is positioned between one end of the balance bar 32 and the partition 21 and normally urges the link 31 and the first tapered valve element 20 downwardly into closed position with respect to the opening 19 in the partition 18. The other end of the balance bar 32 has a boss 36 on its upper surface and immediately therebelow a third coil spring 37 is positioned between the balance bar 32 and the partition 18. The springs 35 and 37 prevent undesirable oscillation of the first tapered valve element 20 and yet enable it to be responsive in operation to pressures generated within the flash vaporization chamber 13 as well as to reduce pressures in the manifold pressure responsive chamber 17.
By referring to FIG. 3 of the drawings, it will be seen that an upper tubular portion 38 of an inlet manifold or communicating part thereof is partially disclosed and that it is in communication with an adaptor ring 39 which has an annular collar 40 the uppermost portion of which is inwardly and downwardly curved to form an annular throat 41 which ends immediately above a plurality of circumferentially spaced openings 42 in the annular collar 40 and communicates with an annularchamber 43 therein. The annular chamber 43 communicates with a tube 44 which in turn extends directly to and communicates with the manifold pressure responsive chamber 17 of the multi-chambered pressure vessel 10. The tube 44 is preferably insulated as at 45.
Still referring to FIG. 3 of the drawings it will be seen that the lower tubular portion of a conventional carburetor 46 is shown in registry with the upper portion of the adaptor ring 39 and the throat 41 therein so that air flowing downwardly from the carburetor and an air cleaner thereabove as indicated by the arrows in FIG. 3 will move downwardly through the throat 41 of the annular collar 40 and downwardly through the connecting portion 38 of the inlet manifold of the internal combustion engine.
Those skilled in the art will observe that negative pressures existing in the inlet manifold as a result of the movement of the pistons in the cylinders of the internal combustion engine are extended by the adaptor ring 39 to both the carburetor 36 and the manifold pressure responsive chamber 17 of the multi-chambered pressure vessel 10 hereinbefore described. The diaphragm 25 in the chamber 17 thus responds to the degree of such negative pressure by moving downwardly and opening the inverted tapered valve element 23 with respect to the tapered valve seat member 22 in like degree.
Referring again to FIG. 1 of the drawings, it will be seen that a gasoline or other liquid fuel delivery tube 47 extends from a preheater 48 to a point within the flash vaporization chamber 13 where it is directed upwardly toward the thin walled partition 14 and the central unbroken area thereof. Liquid fuel delivered against this thin walled partition is thereby deflected downwardly as indicated by the broken lines against a coiled heating element 49 which is an electrical resistance coil in an insulating medium such as glass as for example the commercially available Calrod elements as used in domestic electric ranges and the like. The ends of the coiled heating element 49 extend outwardly through a side wall of the multi-chambered pressure vessel 10 and are connected to a source of electrical energy such as for example a modified alternator that will maintain a desirable uniform voltage despite fluctuations in the revolutions per minute rate of the internal combustion engine driving the alternator. It has been determined that a 115 volt alternator arranged to produce a satisfactory even voltage at a suitable amperage operates the coiled heat exchaner 49 satisfactorily and maintains a surface temperature of between 1600° F. to 1800° F. which is necessary to maintain a desired temperature in the flash vaporization chamber to insure flash vaporization of water and gasoline or other fuel directed thereinto. A second tube 50 also extends into the flash vaporization chamber 13 and water is delivered therethrough as from a preheater 51 and the arrangement of the tube 50 and its direction against the thin walled partition 14 is the same as that of the tube 47 hereinbefore described. In order that the preheaters 48 and 51 for the gasoline and the water will operate as such, an extension of an exhaust pipe 52 is positioned therethrough, the extension of the exhaust pipe 52 communicates with the heat exchanger chamber 11 at one side thereof and with a tube 53 at the other side thereof which communicates directly with the exhaust manifold of the internal combustion engine. Arrows in the exhaust pipe 52 and the tube 53 indicate the flow of the exhaust through the heat exchanger chamber 11 and the preheaters 48 and 51 respectively.
In order that the desired operating temperature may be maintained within the flash vaporization chamber 13, a thermostat 54 is positioned partially therein and the electrical switches actuated thereby are in connection with circuit wires 55 extending therefrom.
By referring now to FIG. 2 of the drawings, a diagrammatic illustration of a fuel system for an internal combustion engine incorporating the hot fuel gas generator of this invention may be seen wherein an internal combustion engine 57 has an inlet manifold 38 and an exhaust manifold 58 with the adaptor ring 39 in communication with the inlet manifold 38 and the carburetor 46. Movable linkage 59 on the carburetor 46 provides a conventional throttle control of the engine 57. Gasoline or other fuel is supplied to the carburetor 46 by a supply tube 60 controlled by a valve 61 and air is supplied the carburetor 46 by an air cleaner 62. Gasoline or other suitable fuel is supplied the tube 47 by a variable discharge pump 63 which like the valve 61 is electrically operated and water is supplied the tube 50 by a variable discharge pump 64 which is also preferably electrically actuated. An adjustment screw 65 is shown on the uppermost surface of the multi-chambered pressure vessel 10 and by referring back to FIG. 1 of the drawings, it will be seen that its inner end is engaged against the upper surface of the center of the diaphragm 25 so that a desirable adjustment of the inverted tapered valve element 23 can be provided as necessary for satisfactory idling of the internal combustion engine.
OPERATION
Operating an internal combustion engine with the device of the invention in a fuel system as described herein requires first starting the engine with the operation of the carburetor 46 by supplying it with gasoline through the tube 60 by opening the valve 61. Simultaneously the variable delivery pumps 63 and 64 are started as by way of an interconnecting electrical circuit, not shown, and the coiled heat exchanger 49 is energized. The starter, not shown, is energized to move the pistons in the internal combustion engine and air flows downwardly from the air cleaner 62 through the carburetor 46, the daptor ring 39 and the inlet manifold 38 and the engine starts in its usual manner, thus operating conventionally with the carburetor 46 which provides a rich suitable starting fuel. After a few seconds, usually from fifteen to thirty seconds, the valve 61 may be closed shutting off the supply of gasoline to the carburetor 46 as by this time a suitable volume of hot fuel gas has been generated in the multiple chambered pressure vessel 10 and is being moved into the adaptor ring 39 by way of the pipe 44 so that the engine continues its operation on the hot fuel gas which is highly gasified compared with the starting mixture that had been supplied by the carburetor 46. The carburetor 46 continues its function in controlling air necessary for combustion and the usual throttle linkage 59 remains the same. The exhaust of the engine or part of it as desired, is delivered to the heat exchanger chamber 11 where it supplements the heat being supplied by the coiled heat exchanger 49 in maintaining the necessary 1600° F. to 1800° F. in the flash vaporization chamber 13.
Delivery of the gasoline or other fuel (and kerosene operates practically as efficiently) to the vaporization chamber 13 results in its flash vaporization and rapid pressurization of the chamber 13 which of course extends upwardly through the apertures 15 in the thin walled partition 14. A build up of the pressure and volume in the chamber 13 causes the first tapered valve element 20 which has a flat area bottom portion, to move upwardly in the opening 19 and this action is controlled by the springs 35 and 37 operating on the opposite ends of the balance bar 32. The tension of the springs 35 and 37 is such that a satisfactory working pressure is maintained in the flash vaporization chamber 13 and this extends into the valve chamber 16 at a flow rate and in a volume as required by the internal combustion engine which is being supplied from the manifold pressure responsive chamber 17. As the engine fuel demand increases, the change of manifold pressure flexes the diaphragm 25 downwardly and opens the inverted tapered valve element 23 in relative greater degree to supply the same. A substantial downward movement of the valve element 23 causes its bottom to engage the boss 36 on the balance bar 32 which accelerates and/or increases the opening of the first tapered valve element 20 to thereby increase the volume and pressure and flow of the hot fuel gas into the valve chamber 16. Rapid fluctuations in the diaphragm and the valve 23 responsive to rapidly changing demands of the engine as occasioned by speeding up and slowing down the same are not directly communicated to the first tapered valve element 20 and an even and desirable flow and volume of hot fuel gas is thus maintained.
It will thus be seen that the multi-chambered pressure vessel performs a number of useful and highly desirable functions in first flash vaporizing the water and fuel and forming a superheated fuel gas which is then stored in sufficient volume and at sufficient pressure to provide for the demands of the internal combustion engine with which the device is being used. The arrangement of the valves are such that they respond in a pressure and volume regulating action which matches the fuel demand of the engine.
Tests of conventional automobiles and engines equipped with the hot fuel gas generator as disclosed herein show near zero levels of atmospheric pollutants in the exhaust which eliminates the need of any catalytic convertors or other devices which attempt to treat the effect and not the cause. The tests also indicate a very substantial increase in the miles per gallon obtained from the hot gas fuel generated by the device of the invention as compared with the same amount of fuel supplied the same engine in the same vehicle through the conventional carburetor and it will be apparent to those skilled in the art that the use of the hot fuel gas generator disclosed herein will enable the automotive engineers to considerably increase the efficiency and performance of the conventional automobile engines by again increasing the compression ratio and changing the timing as the present compression ratios and timing have seriously affected performance, horse power and torque in attempting to eliminate atmospheric pollutants.
Those skilled in the art will also observe that fuel additives may be used if desired although anti-knocking additives are not necessary as the hot fuel gas generated by the device of the invention results in a sufficiently slow burn of a highly gasified fuel to avoid knocking tendencies. It will also be apparent that decomposition of a fuel molecule may occur without combustion occuring unless there is sufficient time and sufficient oxygen. Such decomposition (pyrolysis) produces products which may be more toxic than the original fuel and the elimination of the possibility of such pyrolysis products in the exhaust may be achieved by insuring as complete combustion as possible with the invention hereinbefore described.
Although but one embodiment of the present invention has been illustrated and described, it will be apparent of those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention, and having thus described our invention what we claim is. | A hot fuel gas generator for an internal combustion engine simultaneously vaporizes gasoline and water in a multi-chambered heated pressure vessel having built in regulators for controlling pressure and volume and delivers the resulting superheated steam and gaseous fuel to the internal combustion engine downstream from the usual carburetor. A single device operating at a very high temperature, for example 1600° F., is used for the simultaneous vaporization of the fuel and water to develop desirable working pressure and volume. The high temperature steam and gaseous fuel positions the fuel molecules at the greatest degree of separation from each other providing the greatest opportunity for contact of the oxygen, the reacting species in the gaseous condition as chemical reactions occur only between particles at the atomic or molecular level and it is necessary for the reacting species to be in actual contact at the time of reaction. The hot fuel gas produced therefore enables complete combustion and the elimination of the atmospheric pollutants common in the operation of internal combustion engines and increases the energy obtained from the fuel. | 5 |
BACKGROUND OF THE INVENTION
a) Field of the Invention
This invention relates to a new or improved counterbalance system for use in overhead doors, to a drum for use therein, and to a door installation employing such system.
b) Description of the Prior Art
Over the years, numerous designs of counterbalance systems for upwardly opening or overhead doors have been devised, and examples are shown in various prior patents, such as U.S. Pat. No. 1,469,542 Storms, U.S. Pat. No. 1,603,379 Dautrick and U.S. Pat. No. 3,094,163 Herber, and more recently, an earlier design of my own shown in U.S. Pat. No. 4,887,658. The door opening arrangements disclosed in the foregoing patents make use of weights to provide the counterbalance force required during door opening. Door opening systems employing springs to provide the counterbalance force are well known, and are widely used, particularly in domestic garage doors.
Various forms of torsion or tension springs may be employed utilizing systems of cables and pulleys to transmit the spring force to the door. Spring operated counterbalance systems for doors tend to be troublesome to install, and while such systems are often not unduly expensive, they can be troublesome from the point of view of maintenance, and are subject to failure, for example through fracture of a spring or the like. Furthermore, with spring counterbalance systems it is difficult if not impossible to ensure that the spring force is accurately matched to the door load throughout the range of door opening movement.
SUMMARY OF THE INVENTION
The present invention provides a counterbalance system for an overhead door, such door being movable from a closed position wherein it is arranged in a generally vertical orientation closing a doorway and an open position wherein it is disposed above said doorway and at least partially horizontally oriented, guide means acting between the lateral edges of the door and the sides of the doorway to guide the door in its movement between open and closed positions, said counterbalance system comprising: a spool adapted to be rotatably mounted on a horizontal axis on the structure surrounding the doorway and cable means connected to said spool and said door such that rotation of said spool in a direction to wind the cable onto the spool applied through the cable a force urging the door to move in the opening direction, the weight of the door as it moves away from the closed position being supported initially by said cable and subsequently to an increasing extent by said guide means as the door moves towards the fully open position; a winding drum fixed to rotate with said spool; an elongate flexible load transmitting element connected to said drum to unwind therefrom as said spool rotates to wind the cable thereon, and vice versa; said force-transmitting element freely suspending a counterweight such that the mass thereof provides a torque acting on said drum said spool and said cable to urge said door in the opening direction; and means for varying said torque in accordance with the rotational position of said drum and said spool, such that the opening force applied to said door diminishes in relation to the proportion of the weight of the door that is supported by said cable means.
The torque varying means preferably comprises a U-shaped channel of conico-spiral configuration to receive a force transmitting element in the form of a second cable which supports a counterweight that is raised or lowered as the drum is rotated in one direction or the other. In an alternative configuration the force transmitting element is in the form of a thick cable or belt that is wound on the drum in a single coil such that the radius at which the cable or belt winds onto the drum varies continuously as the drum rotates, and the torque applied to the drum therefore varies as a function of the thickness of the cable or belt and the length of it that is coiled onto the drum.
The spool and the drum may be separate elements each attached to a shaft that is mounted to rotate at the top of the doorway, a drum and a spool being positioned in proximity to each edge of the doorway. The force transmitting element may be a second cable that either supports the counterweight directly, or which is formed in a loop having one end anchored to the door frame, the counterweight being carried by a pulley that is supported in the loop.
Preferred embodiments of the invention as disclosed herein provide a door counterbalance system that is particularly easy to install, and that also affords a ready means of adjustment upon installation to achieve accurate counterbalancing. The disclosed counterbalance system is relatively cheap, and is safe and highly reliable in operation. The basic counterbalance system is readily adaptable to accommodate various types of overhead doors whether they be standard lift, high lift, or even vertical lift.
From another aspect the invention provides for use in a counterbalance system for a vertically movable door, a drum comprising a hub defining therein an axle bore extending from end-to-end of the drum, said drum having an outer periphery configured with a continuous groove extending generally helically thereon and progressing from one end of the drum to the other, the drum defining in the axial direction a first region wherein said groove defines a plurality of turns about the axis at a constant radius; a second region wherein the radius of said groove from said axis increases progressively from said constant radius to a maximum radius that is of the order of at least twice said constant radius, said groove continuing at said maximum radius through a plurality of turns about said axis.
Preferably there are three turns of the groove at said minimum (constant) diameter, and five or six turns at said maximum diameter. The drum is suitable for use with standard lift doors using the groove essentially only up to the end of the intermediate section. For high lift doors, a length of the groove at said maximum diameter is used, this length corresponding to the vertical lift section of the door opening movement. For purely vertical lift doors, only the maximum diameter region of the groove is used.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will further be described, by way of example only, with reference to the accompanying drawings wherein:
FIG. 1 is an overall perspective view from the inside of a building showing a preferred embodiment of an overhead door counterbalance system in accordance with the invention;
FIG. 2 is an elevational view of the door and counterbalance system with parts omitted for reasons of clarity, the door being shown in different positions in the left and right hand side of the figure;
FIG. 3 is an elevational view to a larger scale showing an important part of the counterbalance system;
FIG. 4 is a fragmentary view taken in the direction indicated by the arrows IV--IV in FIG. 3; and
FIG. 5 is a side elevational view of the door counterbalance system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, an overhead garage door 11 is formed by a series of horizontally divided sections 12 pivotally interconnected by hinges 13. At each edge of the door the hinges carry a laterally projecting hinge pin 13a which in known manner supports a roller or the like (not shown) received within a track structure 14 mounted in the door frame 15 at each side of the doorway and adapted to guide movement of the door sections during opening and closing. As shown, the tracks 14 are vertically arranged and extend at their upper ends through a curved intermediate section 14a into a generally horizontal top section 14b that projects away from the doorway, the top sections being supported by any suitable means, e.g. hangers attached to a ceiling (not shown). The upper edge of the top door section and the lower edge of the bottom door section likewise carry laterally projecting pins 13b carrying guide means such as rollers 8 (see FIG. 3) which cooperate with the track 14.
Extending horizontally above the doorway is a shaft 16 rotatably carried in a central bearing 17 and in two lateral bearings 18 (see FIG. 3) adjacent opposite side edges of the door.
Close to each end of the shaft 16 and fixed to rotate with it is a flanged cylindrical spool 19 positioned substantially in alignment with the lateral edge of the door. A cable 20 is wound on this spool and extends vertically downwards being attached at its end to a bracket 21 at the lower corner of the bottom door section. On the opposite side of the bearing 18 the shaft 16 carries a drum assembly 22 which is best seen in FIGS. 3 and 4. The drum 22 has an axial bore 23 extending therethrough between a flange 24 at one end and a collar 25 at the other. A clamping screw 26 is threaded in a radial through bore 27 in the collar 26 and can be tightened to engage its tip 28 against the surface of the shaft thereby fixing the drum 22 to rotate with the shaft. Between the flange 24 and the collar 25, the drum is of generally frusto-conical outline defined by a continuous groove 29 that extends in a spiral/helical manner from a small diameter end adjacent the flange 24 to a larger diameter end adjacent the collar 25. The radius of the groove 29 from the axis of the shaft 26 is at a maximum adjacent the collar 25, and remains constant for about 5 or 6 turns as indicated by the region 30. Adjacent the flange 24 there is a region of minimum diameter 31 extending for about 3 turns, and between these two regions is an intermediate region 32 wherein the radius of the groove changes in a continuous manner.
A cable 35 is wound onto the drum in the groove 29, one end of the cable being attached to the flange 24 by means of a grub screw 36, the cable then being laid into the groove 29 to an extent corresponding to the rotational position of the drum 22. From the drum the cable 35 descends in a loop 37 and has its opposite end 38 attached to a bracket 39 mounted on the door frame 15. An elongate counterweight 40 has a clevis 41 attached to its upper end and providing a bearing for a grooved pulley wheel 42 which runs on the cable loop 37.
Four radially extending cylindrical sockets 33 are provided spaced at 90° intervals around the periphery of the collar 25.
As shown particularly in FIGS. 1 and 4, a tubular guide housing 44 is vertically arranged adjacent each edge of the door frame 15 and is attached thereto e.g. by wood screws 45. The housings 44 guide the counterweights 40 for vertical movement therein. In addition, the housings 44 provide protection for the counterweights to ensure that their movement is unimpeded, and protect the users from inadvertent contact with the counterweights.
As will be appreciated from the foregoing description, as the door 11 is moved from its closed position shown in FIG. 1 shown in the left hand side of FIG. 2, to its opened position as shown in the right hand side of FIG. 2, the door sections 12 guided by their pin mounted rollers 8 in the tracks 14, moves successively from the vertical position, around the curved track sections 14, into a substantially horizontal position wherein they are supported by the top portions 14b of the guides. During this movement the weight of the door 11 is substantially counterbalanced by the counterweights 40 so that the effort required to move the door from its closed to its opened position is minimal. Furthermore, this effort does not vary substantially throughout the range of opening movement of the door. This effect is achieved by careful selection of the configuration of the drums 22 and the mass of the counterweights 40 in relation to the weight of the door and the diameter of the spools 19. Thus, for example, 10 for a door 11 having a weight of say 200 pounds, each counterweight system must provide a counterbalance force of up to 100 pounds, and this force must diminish in proportion to the increasing proportion of the weight of the door that is supported by the horizontal top sections 14b of the track.
When the door is in the closed position as shown in the left hand side of FIG. 2, the cable 35 is wound onto the drum 22 as far as the maximum diameter region 30 of the groove 29. At this location, the lifting force applied to the cable 20 as a result of the mass of the counterweight 40 will be a function of the ratio of the spool diameter 19 to the diameter of the region 30 of the drum groove. As shown, this ratio is approximately 2:1, and therefore two counterweights 40 of mass 100 pounds each will provide sufficient force to counterbalance the full weight of the door.
As the door is opened, the cable 35 unwinds from the drum groove 29 at a progressively decreasing radius, and therefore the torque applied to the shaft 16 also progressively decreases until the minimum-radius groove region 31 is reached, at which location the cable leaves the drum at a radius very much less than the radius of the spool 19, so that the torque applied to the shaft 16 is correspondingly reduced as the door approaches its fully opened position and substantially its entire weight is supported by the top track portions 14b.
Adjustment of the counterbalance force can be effected quite easily if it is necessary to make slight changes to more closely match this force to the manner in which the effective weight of the door is reduced during opening. To do so, when the door is in the fully closed position, a torque bar or the like implement (not shown) can be inserted into one of the sockets 33 in the drum collar 25 and used as a torque arm to support the drum 22 against rotation under the force of the counterweight, whereupon the screw 26 can be slackened, freeing the drum relative to the shaft. The drum can therefore be rotated under control of the torque bar to vary the extent to which the cable 35 is unwound from the drum, and thus vary the torque applied to the shaft 16 through the counterweight, with the door 11 in its fully closed position. When the desired position of angular adjustment of the drum 22 has been reached, the screw 26 is re-tightened to once again clamp the drum to the shaft.
Likewise, upon installation of the counterbalance system, the counterweight 40 may simply be placed in position as shown at the right hand side of FIG. 2 and supported on a block or the like. With the shaft 16 and its spools 19 and drums 22 mounted as shown, the cable 35 can be attached to the flange 24 and wound around one or two turns of the drum, thereafter being passed downwardly around the pulley 42 and looped back to the mounting bracket 39. With the clamping screw 26 slackened, the torque bar can thus be used to rotate the drum 22 winding the cable onto it and thereby raising the counterweight 40. When the counterweight has been raised to the desired position, the screw 26 is tightened to clamp the drum to the shaft.
The counterbalance system can readily be adapted for use with what are referred to as "high lift" doors, i.e. doors which upon opening initially travel vertically for a substantial distance before the door sections start to turn into the horizontal position. In such applications a track such as that shown in broken lines at 14' (FIG. 5) is utilized. It will be seen that as compared with the earlier described embodiment, in this configuration the door must be raised vertically by a distance D before the door sections start to swing out of the vertical position. This is readily accommodated by the counterbalance system shown since all that is necessary is to wind the cable 35 around the maximum diameter region of the groove 29 over a length corresponding to D. When the system is thus configured, it will be appreciated that, moving from the closed position, over the initial opening distance D. the torque applied to the drum 23 to the cable 35 will be constant, as also will be the counterbalance force applied to the door through the cables 22. This is necessary since during the initial distance D from the closed position, the entire weight of the door is supported by the cables 20.
It will be seen that with the cable 35 forming a loop 37 as shown in FIG. 4, the vertical movement of the counterweight 40 will equal approximately 1/2 of the length of cable unwound from the drum. It would be possible to dispense with the loop 37 and suspend the counterweight 40 directly on the cable 35. In this arrangement the full mass of the counterweight would be applied to the cable 35, but of course the vertical movement of the counterweight would correspond exactly in length to the length of cable unwound, and during unwinding, the counterweight would be subjected to greater lateral movement. The effect of lateral movement would however be rather minimal and could easily be absorbed by the guide housing 44. The guide housing could conveniently be made of a plastic tubing, e.g. of PDC, so that minimal frictional forces would be encountered.
As compared to the arrangement shown, the arrangement discussed whereby the counterweight 40 is attached directly to the cable 35 would enable one to use a counterweight that is half the mass of the counterweight 40, or alternatively would enable one to use a drum having a maximum diameter of the groove 29 approximately 1/2 of the diameter shown in FIG. 3. | An overhead door system employs counterweights which operate through cables connected to a drum which tapers from one end to the other so that the effective force acting on the door in the opening direction is reduced as the proportion of the weight of the door to be supported reduces. The system is adjustable readily to accommodate different types of doors having different opening characteristics in terms of the proportion of the doors weight that must be counterbalanced at different stages of the door opening movement. | 4 |
This application is a continuation of now abandoned application, Ser. No. 07/443,123, filed Nov. 30, 1989.
FIELD OF THE INVENTION
The present invention relates to enzymes coded by retroviral genes, in particular to protease, reverse transcriptase and endonuclease (integrase) enzymes, and to a method for producing them. More particularly, the present invention relates to a method for producing the above-mentioned enzymes in the form of matured or active individual protein molecules rather than as part of a fused protein molecule, by causing expression of at least one kind of gene in which a protease gene is necessarily selected from the above-mentioned three kinds of enzyme gene groups of retrovirus, namely, the following four sets; the protease gene alone: the protease and reverse transcriptase genes: the protease and endonuclease genes: the protease, reverse transcriptase and endonuclease genes; by means of the recombinant DNA technique, and at the same time, causing procession of the thus expressed product itself by means of protease within the expressed product. In addition, the present invention also relates to various proteins obtained by this method. The present invention provides such enzymes as protease, reverse transcriptase and endonuclease useful for preparing materials for genetic engineering or retrovirus research, materials for developing pharmacotherapy drugs relating to retrovirus infections diseases, diagnostic antigens and diagnostic antibodies, as well as for preparing antigens for vaccines.
PRIOR ART
[Definition of Retrovirus]
A retrovirus is the generic name for viruses classified as belonging to the retrovirus family, and the features common to these viruses are that they have an envelope, single-stranded RNA genome and reverse transcriptase. These viruses include the spherical shape having a diameter of about 80 to 100 nm, composition of two or three molecules of linear (+) stranded RNA genome with molecular weight of about 3×10 6 in the viral particle. More particularly, the retrovirus family is further classified into the following three subfamilies, i.e., oncovirus, lentivirus and spumavirus (R. E. F. Matthews Edt. "Classification and Nomenclature of Viruses-Fourth Report of the International Committee on Taxonomy of Viruses", pp. 124-128, S. Karger [Switzerland], 1982). Known viruses classified as oncoviruses, also named RNA tumor viruses, include human T cell leukemia virus, feline leukemia virus, murine sarcoma virus, moloney murine leukemia virus, bovine leukemia virus, hog leukemia virus, avian leukemia virus, avian sarcoma virus, arian myeloblastosis virus, and Rous associated virus. Known viruses classified as lentiviruses which are commonly known as viruses causing slow viral infection, include human immunodeficiency viruses types 1 and 2 (hereinafter respectively referred to as "HIV-1" and "HIV-2"), simian immunodeficiency virus, visna virus causing ovine encephalomyelitis, maedi virus causing jaagsiekte, caprine arthritic encephalitis virus, equine infectious anemia virus, and bovine lymphadenitis virus ("Current Topics in AIDS", vol. 1, pp. 95-117, John Wiley & Sons, 1987; Advances in Virus Research, vol. 34, p. 189-215, 1988). The viruses classified as spumaviruses, also named foamy viruses, infect such mammals as humans, monkeys, cattle and cats. Foamy virus and syncytial virus isolated from these hosts are well known. The term retrovirus as used herein can be taken to include all viruses, known as well as unknown, retroviruses characterized as described above.
[Present Situation Concerning Fundamental Research in Retroviral Genes]
Retroviruses are important not only from the point of view of the serious and often lethal infectious diseases which they cause in men and other animals, as well as a contagious disease common to them, but they are also useful for understanding diseases such as sarcoma and for the preparation of material for use in research and genetic engineering. Consequently, as massive reports about these viruses have been made, the present situation concerning typical retroviruses is expediently explained as follows. As is well known, before 1980 retroviruses had been studied, as a material for the oncogenic mechanism, and from the point of view of clarifying strange, slow virus infectious disease which resulted in incurable diseases. Since the discovery of AIDS in the United States in 1981, comparative studies on various retroviruses have intensively been carried out using the full range of techniques in epidemiology, immunology, virology and molecular biology as research materials or experimental models with a view to establishing methods for treatment and prevention of AIDS. A huge volume of useful reports concerning AIDS has already been accumulated (Advances in Virus Research, vol. 34, pp. 189-215, 1988; Annual Review of Immunology, vol. 6, pp. 139-159, 1988; Microbial Pathogenesis, vol. 5, pp. 149-157, 1988). From among these research reports, an outline regarding HIV genes is described below ("HIV and Other Highly Pathogenic Viruses", pp. 33-41, Academic Press, Inc., 1988; "The Control of Human Retrovirus Gene Expression", pp. 79-89, Cold Spring Harbor Laboratory, 1988; Cytological Engineering, vol. 7 (Suppl. 1), pp. S5-S15, 1988): the viral genome forms a complex with a reverse transcriptase and the structural protein in the core of the viral particle, and is present, together with a primer tRNA, in the vital particle; the viral genome comprises about nine different genes, including the basic three major genes encoding the vital particle components essential for virus multiplication, i.e., the gag (group-specific antigen) gene encoding the precursor of the core protein, the pol (polymerase) gene encoding the precursor of three different enzymes, and the env (envelope) gene encoding the precursor of the glycoprotein of the envelope; these genes are arranged from the 5' end to the 3' end in this sequence gag, pol, and env; more specifically, gag. pol. vif . . . and env are arranged adjacent to the respective next ones in this order, and part of the 5' end region of the pol gene overlaps about 240 bases with the 3' end region of the gag gene, with a different reading frame. The frame shifting is thought to occur during translation of this overlapping portion, so that translation proceeds through conversion of the termination codon; expression of the entire region of the pol. gene having a total length of about 3 kb including that overlapping portion leads to production of the above-mentioned enzyme precursor (molecular weight: 160 kd) in the form of a fusion protein NH 2 --Gag--protease--reverse transcriptase--integrase--COOH, and then, the thus produced polyprotein is cleaved by an existing protease derived from the virus or by the protease activity within the same molecule, and is processed into the individual mature proteins, i.e., into the Gag proteins and the enzymes protease, reverse transcriptase (p66 and p51) and integrase (p32).
All enzymes mentioned above play important roles in the process of multiplication and maturity of virus or in that of provirus formation, and the following functions have been confirmed or presumed: protease participates in post-translational processing, and core formation or maturity process of viral particle, and the action of protease is highly specific toward viruses from which it is derived. Reverse transcriptase functions as an RNA dependent DNA polymerase catalyzing the process of reverse transcription of the genomic RNA into DNA, which is the basic stage of the virus multiplication process, and at the same time, the reverse transcriptase is furthermore known to have the ribonuclease H activity specifically digesting the RNA strand of the RNA-DNA heteroduplex as well as the DNA dependent DNA polymerase activity producing double-stranded DNA, and is popularly used as a tool in genetic recombination. Integrase is an endonuclease acting on the DNA chain, catalyzing recognition and excision of the part to be integrated into the host chromosome which is of linear or circular virus double-stranded DNA reverse--transcribed from viral genomic RNA through the above-mentioned reverse transcription process and is thus considered to participate in the process of formation of provirus.
[Present Situation Concerning Applied Research on Retroviral Gene and Problems Involved]
In the area of applied retroviral gene research, active efforts are being made to express the HIV env gene, principally in an attempt to develop a diagnostic reagent or vaccine against AIDS ("Vaccine", pp. 558-567, W. B. Saunders Company, 1988; Science, vol. 18 [No. 12], pp. 110-119, 1988). With regard to research and development in the application area of retroviral gag and pol genes, the following efforts are known: for example, a suggestion that the protease gene product is useful as a reagent for the development of an anti-retroviral drug having a high specificity as a therapeutic drug and for the fundamental research on retroviruses (Cytological Engineering, vol. 7 [Suppl. 1], pp. S67-S77, 1988); a method for producing reverse transcriptase using a cell strain established from the hog spleen infected with hog leukemia virus falling under the category of oncovirus (Japanese Patent Provisional Publication No. 59-118,081); a method for producing reverse transcriptase using an Escherichia coli strain transformed with an expression vector carrying the reverse transcriptase gene of avian sarcoma virus falling under the category of oncoviruses (U.S. Pat. No. 4,663,290); and a method for producing reverse transcriptase comprising preparing a DNA fragment of the reverse transcriptase gene region from pol gene of moloney murine leukemia virus falling under the category of oncoviruses, constructing an expression vector carrying said DNA fragment, and then, purifying the product from the culture of the transformant obtained by introducing said expression vector into Escherichia coli (WO 86/06741). Furthermore, the reverse transcriptase enzyme has been used as an antigen in the preparation of a monoclonal antibody for use in the detection of reverse transcriptase derived from avian sarcoma virus (Japanese Patent Provisional Publication No. 61-104,799); as well known currently available, the reverse transcriptase for synthesizing complementary DNA is prepared from avian myeloblastosis virus, and also obtained from moloney murine leukemia virus or Rous associated virus (RAV-2), thus being prepared mainly from the oncovirus itself. As is clear from the above description, the prior art concentrated on the expression of the HIV env gene, components of oncovirus, their oncogenic effect and the use of reverse transcriptase gene thereof. As a matter of practical application, difficulties associated with these prior art techniques include the need to protect against biohazards during manufacturing processes, production cost, production yield, and difficulties relating to enzyme activity, substrate specificity, purity, homogeneity and stability. There is, therefore, a need for the development of a safe low-cost mass production system for high-quality products. At the present time, those relating to the usefulness and industrial application of the various retroviral enzymes do not tend to attract much attention, particularly of researchers. Under these circumstances therefore, the provision of a new method for the mass production of retroviral enzyme products, i.e., protease, reverse transcriptase and integrase at low cost could be expected to stimulate progress in fundamental research relating to viral infection, and the development of pharmacotherapeutic, diagnostic and preventive drugs, and would thus be of considerable significance.
OBJECT OF THE INVENTION
In attempts to overcome the above-mentioned difficulties, we have studied energetically, and as a result achieved a method for mass-producing retroviral enzyme products i.e., enzymes such as protease, reverse transcriptase and integrase, safely in terms of biohazard, at a stable and high production yield, with a low cost.
This achievement is due to success in linking a cDNA fragment prepared so as to necessarily contain a retroviral protease gene with an inducible promotor gene having a high expression ability in a correct reading frame by utilization of the recombinant DNA technology, raising expression of the enzyme gene products, and processing the gene product itself by the expressed protease. We found it possible to produce stably in large quantities the above-mentioned enzymes coded by that cDNA, not as a fusion protein, but individual mature proteins having a specific activity in the culture, by preparing a transformant obtained through introduction of an expression vector carrying the above-mentioned gene cDNA, and applying the two-stage culturing method described later for culture of the said transformant. We found also that such processing was due to the specific activity of protease accounting for part of the fusion proteins which are expression products of the above-mentioned gene, more particularly, that the processing was a phenomenon unique to the retroviral protease. In addition, we have found that these enzymes have very high purity and homogeneity as a result of improved mass production and purification processes, and particularly when retroviral genes expressed resulting enzymes have an activity with a very high substrate specificity unique to retroviruses. The present invention was achieved on the basis of these findings.
According to the present invention, there are provided: a method for producing retroviral enzymes such as protease, reverse transcriptase and integrase; the above-mentioned enzymes as tools in genetic engineering useful for the dissociation and cleavage of viral components, synthesis of complementary DNA, preparation of proviruses through integration of viral genomes into the host cell and transformation of the host cell; the above-mentioned enzymes as tools in protein engineering useful for the functional and structural analysis of protein; the above-mentioned enzymes as virological tools for fundamental and clinical studies useful for the clarification of multiplication mechanism of viruses and for the development of antiviral drugs exerting specific effects on retroviruses; the above-mentioned enzymes useful as diagnostic antigens and for the preparation of diagnostic antibodies to detect retroviral infections, or as antigens for the preparation of immunoglobulin for use in therapy or for the preparation of vaccine for the prevention of secondary infection by retroviruses; and in addition, the above-mentioned enzymes as materials using functions and features of protease, reverse transcriptase and integrase known at present and to be clarified in the future.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph illustrating titers of reverse transcriptase activity of the crude extracts of Escherichia coli transformed with the plasmid pPG280 carrying the HIV pol gene, and Escherichia coli transformed with the vector pUR290 not having the HIV pol gene; FIG. 2 is a graph illustrating the result of Western blot analysis using human serum obtained from HIV carriers, of crude extracts of Escherichia coli transformed with the plasmid pPG280 carrying the HIV pol gene and the vector pUR290 not carrying the HIV pol gene; FIG. 3 is a graph illustrating the elution profile of reverse transcriptase derived from Escherichia coli crude extracts on an anion exchange column; and FIG. 4 is a graph illustrating separation of reverse transcriptase by Affi-Gel Heparin chromatography.
DETAILED DESCRIPTION OF THE INVENTION
The present invention has the following construction:
(I) Selection of retroviral enzyme genes and preparation of DNA fragments:
Various enzymes of retroviruses founded on the abovementioned "Definition", such as protease, reverse transcriptase and integrase, can be used in terms of the enzyme gene of a retrovirus. These genes are used from four sets necessarily containing a protease gene, as described in "FIELD OF THE INVENTION". And, in the case of gene expression by means of the recombinant DNA technique, the above-mentioned various genes are used by being converted into a complementary DNA, for the retroviral genome is an RNA. Such cDNA can be prepared by cloning a proviral genome or the integrated genomic DNA. Further, by using a genomic RNA extracted from the vital particle, that cDNA also can be prepared by being selected from the cDNA library which has been made in accordance with conventional method. However, these preparations are not necessarily easy from the viewpoint of avoiding infection by direct operation with a retrovirus having a high degree of hazard. Therefore, in order to avoid biohazards due to such virus and to save labor in the above-mentioned preparation processes, it is recommended to use a known and cloned retroviral genome. As is seen in the general description cited above, the cloning of various retroviral genomes, the preparation of restriction enzyme maps and the determination of nucleotide sequences have already been reported by researchers throughout the world, and utilization of their achievement may be desirable because of their security and convenience. The available clones include, for example, a plasmid SRA2 (Journal of Virology, vol. 36, pp. 50-61, 1980) which carries the avian sarcoma virus genome deposited as BP-3921 at Fermentation Research Institute, Agency of Industrial Science and Technology, 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki-ken 305, Japan, HIV-1 provirus genome clones, i.e., plasmids pNL3-1, pNL3-2 and pNL4-3 (Journal of Virology, vol. 59[No. 3], pp. 284-291, 1986), and plasmid pNLH402 of E. coli strains UT481/pNLH402 (Microbiology Research Inst. Registration No. 10436) deposited as BP-2417 at the Fermentation Research Institute. cDNA fragments can be prepared from these plasmids by conventional methods, for example, by excising the DNA from the required region of the above-mentioned plasmid clones by means of a restriction enzyme and purifying the resultant product through phenol extraction, chloroform treatment or ethanol precipitation. The restriction enzyme used for excision of the DNA fragments may appropriately be selected by reference to the genomic DNA clone restriction enzyme map. Thus, for example, to excise DNA fragments from the entire gene region of the above-mentioned pNLH402, the restriction enzyme HindIII (Journal of Virology, vol. 59, pp. 284-291, 1986) may be employed.
(II) Production of an expression vector, and preparation of a transformant containing the vector:
An expression vector is produced by linkage with the retroviral genomic cDNA fragment prepared as described above by a conventional method such as that using T4DNA ligase. Any of the following vectors may be used for expression purposes; those conventionally known or commercially available, for example, plasmid vectors of the pSN508 series of the enteric bacteria family (U.S. Pat. No. 4,703,005), plasmid vector pJM105 (Japanese Patent Provisional Publication No. 62-286,930), vectors of pBH103 series (Japanese Patent Provisional Publication No. 63-22,098) of yeast, attenuated varicella virus vector (Japanese Patent Provisional Publication No. 53-41,202), attenuated Marek's disease virus vector (Journal of the Japan Veterinary Society, vol. 27, pp. 20-24, 1984; and Gan Monograph on Cancer Research, vol. 10, 1971), Escherichia coli plasmid vector pUR290 series (EMBO Journal, vol. 2 [No. 10], pp. 1791-1794, 1983), and pSN5182 (Journal of Bacteriology, vol. 157, pp. 909-917, 1984). What is important in the production of the expression vector is to link the above-mentioned enzyme gene in a matching reading frame with a gene which is capable of being highly expressed. Thus for example, when using pUR290 referred to above, the pol gene should preferably be inserted downstream of lacZ gene of the plasmid, or in the case of pSN5182, downstream of the plasmid pstS gene. Furthermore, for carrying that gene, attention should be given to matching the codon reading frames among the genes so as to ensure smooth progress of translation. For example, when the cDNA of viruses such as HIV-1, HIV-2, simian immunodeficiency virus and moloney murine leukemia virus are inserted, the reading frame of the pol gene is linked so as to match with those of genes with high expressing ability, because the protease of such viruses as described above are encoded in the pol gene region. On the other hand, a protease of avian sarcoma virus is encoded in the gag gene region having a different reading frame from the pol gene, and the protease gene of human T-cell leukemia virus or bovine leukemia virus has yet another reading frame differing from those of both the pol and gag genes. In these cases, care is needed to match the reading frames of all the genes, i.e., the retroviral genes e.g. protease gene, pol gene and the gene with high expressing ability, in order to ensure significant expression of the retroviral genes. Matching of the reading frames above can be accomplished using conventional techniques employing enzymes such as restriction enzyme, nuclease Ba131 and mung bean nuclease. The optimum recipient cell used for the purpose of obtaining a transformant through introducing of the thus constructed expression vector should be selected from among host cells allowing multiplication and expression of that expression vector, and at the same time, from these host cells, a cell permitting easy introduction of the expression vector constructed as mentioned above and the detection method should be carefully selected and used. When using the above-mentioned pSN series plasmids as the expression vector for example, it is desirable to use Escherichia coli C75 strains (Microbiology Research Inst. Registration No. 10191) as the host cells, which are transformed in appearance from an alkaline phosphatase non-productive bacteria into a productive one by the introduction of that vector, as the recipient bacteria, and when using pUR290 series, it is able to employ Escherichia coli UT431 (Journal of Bacteriology, vol. 163, pp. 376-384, 1985) which permits selection of a transformant introduced with this vector, with ampicillin resistance as the marker. Introduction of the expression vector into such a recipient cell may be accomplished by a conventional method such as the calcium chloride method (Journal of Molecular Biology, vol. 53, pp. 154-162, 1970). The transformant introducing the enzyme gene expression vector as described above is selected by the above-mentioned marker from the positive colony. Then, after extracting the expression vector DNA through selection from the colony of transformant, it is digested with a restriction enzyme, and the resultant DNA fragments are subjected to agarose gel electrophoresis. Subsequently, the size of the inserted DNA fragment can be measured, and simultaneously, the colony in which the presence of DNA fragment of that gene has been confirmed is adopted as the transformant clone of retroviral enzyme gene expression. For example, when insertion covers the entire pol gene region prepared from pNLH402 into the above-mentioned expression vector pUR290, EcoRI fragment of about 4 kb DNA can be detected.
(III) Confirmation of retroviral enzyme genes expression by the transformant clone and mass production of various enzymes by culture of said transformant:
Confirmation of the enzyme gene expression by the transformant clones can be accomplished, for example, by analyzing the crude extraction liquid of the products of that clone by the use of the Western blot technique. The crude extract can be prepared, for example, by culturing and inducing the transformant in a conventional culture medium, collecting cells by low-speed centrifugation, treating the collected cells with sodium dodecyl sulfate and 2-mercaptoethanol, subjecting them to high-speed centrifugation, and collecting the supernatant liquid. The Western blot technique may be carried out in accordance with the conventional procedure using various commercially available materials in the following steps: subjecting the above-mentioned crude extracts to polyacrylamide gel electrophoresis; transferring the separated protein onto a nitrocellulose membrane by use of a transblotting apparatus, and immersing the membrane into gelatin solution for blocking. The subsequent steps include, when the specimen on the membrane is an HIV pol gene product, for example: causing a primary reaction with human serum of HIV carrier; causing a secondary reaction with peroxidase-conjugated anti-human IgG antibody after washing; causing coloring with hydrogen peroxide solution and a chromogenic agent after washing and detecting a band specifically reacting with the human serum of HIV carrier, thereby confirming expression of the pol gene by the above-mentioned clone. In the case of the specimen being the gene product originating from a retrovirus other than HIV, human serum of an HIV carrier is not employed, but an appropriate retroviral antiserum is used for the primary reaction, and an antibody to human or animal IgG is used for the secondary reaction.
Mass production of the various enzymes such as protease, reverse transcriptase and integrase through culture of transformant for which enzyme expression has been confirmed is conducted as follows: the transformant of Escherichia coli is cultured in LB medium at a temperature of from 30° to 40° C. for from 12 to 35 hours until a bacteria concentration of from 109 to 10 10 cells/ml is reached to prepare seeds for large-scale culture of that transformant; then, inoculating such seeds into fresh medium prepared, and conducting two-stage culture consisting of a pre-culture and an after-culture. The pre-culture is carried out for the purpose of multiplying seed cells and amplifying the expression vector at a temperature of from 10° to 40° C. for from 1 to 24 hours, or more preferably at a temperature of from 15° to 37° C. for from 2 to 12 hours. The pre-culture is discontinued, in the case of Escherichia coli, with a concentration of bacteria in culture, i.e., a turbidity of the culture liquid of OD600 nm =0.4 to 0.7 as the standard. Subsequently, upon completion of this pre-culture, conditions for the induction-culture should be carefully set so that transcription and translation of the enzyme gene linked to the expression vector and the gene product after translation are properly modified, and to achieve individual and single matured proteins having activity, as well as to avoid having the enzyme gene product after translation be decomposed in an unorderly manner by proteolytic enzyme originating from the host cells thus losing its activity. The culture induced should preferably be carried out at a temperature of from 10° to 30° C. for from 1 to 40 hours, or more preferably, at a temperature of from 15° to 28° C. for from 3 to 35 hours. Considering the property of the expression vector used, expression may be induced or accelerated, for example, by causing starvation of phosphate ion in the medium at the start of the induction-culture or by adding and mixing an inducer into the medium. Application of the abovementioned two-stage culture permits production of various enzymes of retroviruses such as protease, reverse transcriptase and integrase, not in the form of fusion proteins, but as independent active proteins, i.e., as individual and single mature proteins usually at a high yield of from 1 to 10 mg per liter of medium.
(IV) Purification of various retroviral enzymes such as protease, reverse transcriptase and integrase which are mass produced by means of an expression vector:
This step can be accomplished by any combination of conventional methods, including, for example, extraction of the cultured product of the transformant through the use of precipitants, centrifugation or filtration; preparation of crude extracts through breakage or crushing of the transformed cells by the application of ultrasonic treatment, high pressure treatment or a homogenizer; purification through adsorption-elution treatment by means of silica or activated charcoal, salting-out, or precipitation by means of organic solvents; high-grade purification by means of ultracentrifugation, column chromatography or electrophoresis; or a method for purifying a gene product through fractionation by density-gradient centrifugation following adsorption-elution with silica and activated charcoal (Japanese Patent Provisional Publication No. 63-297) .
The enzymes such as protease, reverse transcriptase and integrase available by the method of the present invention may be provided in the form of liquid, dried powder or adsorbed onto filter paper or a membrane, and enclosed in an ampule, a vial or other small container. In the dried powder, the enzyme may be used in a necessary amount after dissolving in distilled water to the volume before using. When it is adsorbed onto filter paper or membrane, it should be used after wetting with a solution as prescribed in the instructions.
The method of the present invention is described below in more detail with reference to examples. The present invention is not limited to the examples described below.
(Experiment 1)
Measurement of activity of reverse transcriptase: a reaction mixture is made up comprising 50 mM tris-HCl(pH 8.3), 50 mM potassium chloride, 10 mM magnesium chloride, 3 mM dithiothreitol, 0.1 W/V% Nonidet P-40 (made by Shell Oil [U.S.A.]), 20 μg/ml (rA) n (dT) 12-18 (Pharmacia [Sweden]), 0.5 mM dTTP (deoxy thymidine triphosphate), and 1 μCi [ 3 H] dTTP (deoxy thymidine triphosphate). To this reaction mixture was added specimen in an amount of 5 μl into a total volume of 50 μ, and the mixture was incubated at 37° C. for 10 minutes. Then the mixture is immediately cooled on ice, and filtered through a filter paper DE81 (made by Wattman [England]). The filter is washed well with 5% sodium phosphate solution, and then with ethanol after water rinsing. After drying, radioactivity is measured by means of a liquid scintillation counter.
(EXAMPLE 1)
Construction of an expression vector carrying the pol gene of lentivirus: 5 μg of plasmid pNL4-3 DNA (Journal of Virology, 59(2): 284-291, 1986) carrying the HIV proviral genome DNA was added to 5 μl HindIII, 20 μl 5×RM (50 mM tris-HCl [pH 7.5], 35 mM MgCl 2 , 300 mM NaCl), diluted with distilled water to a total volume of 100 μl, and after incubation at 37° C. for an hour, extraction of the solution was carried out with phenol saturated with TE(10 mM tris-HCl [pH 7.5], 1 mM EDTA). The water layer was treated with chloroform before ethanol precipitation. To the mixture of 1 μl of the solution prepared by dissolving the precipitation into 10 μl TE, 0.1 μg (1 μl) of plasmid pHSG398 DNA cleaved by HindIII and treated with alkaline phosphatase, and 2 μl of 10×ligation buffer (660 mM tris-HCl [pH 7.6], 66 mM MgCl 2 , 100 mM DTT and 1 mM ATP), 1 μl T4DNA ligase was further added and the total volume was brought up to 20 μl with distilled water. Then, incubation was applied at 15° C. for 12 hours. Subsequently, Escherichia coli strain JM103 was transformed with this reaction liquid in accordance with the calcium chloride method (Journal of Molecular Biology), 53: 154, 1970), and chloramphenicol resistant colonies were selected on an LB medium plate (1 W/V% Bactotrypton, 0.5 W/V% Bacto-yeast extract, 1 W/V% NaCl and 1.5 W/V% agar) containing 20 μg/ml choramphenicol. Plasmid DNA was extracted from the chloramphenicol resistant clone by a conventional method, and clone pNLH402 was obtained by selecting a clone containing about 4.0 kb fragments originating from plasmid pNL4-3 DNA through HindIII excision.
HindIII in an amount of 5 μl and 5×RM in an amount of 10 μl were added to 5 μl (5 μg) of plasmid pNLH402 DNA, and the mixture was diluted with distilled water to a total volume of 50 μl. The mixture was incubated at 37° C. for an hour, and after phenol extraction and chloroform treatment, the mixture was subjected to ethanol precipitation. The resulting precipitate was added to 10 μl of 5×RM and 5 μl of BglII and was diluted with distilled water to a total volume of 50 μl, whereby it was completely dissolved. The mixture was incubated again at 37° C. for an hour, and after phenol extraction and chloroform treatment, the resulting product was subjected to ethanol precipitation. The thus obtained DNA was dissolved into 10 μl of TE.
At the same time, 5 μl of HindIII and 10 μl of 5'RM were added to 5 μg of expression vector pUR280 DNA (The EMBO Journal, 2(2):1791-1794, 1983). The mixture, diluted with distilled water to 50 μl, was incubated at 37° C. for an hour, and after phenol extraction, chloroform treatment and ethanol precipitation, 10 μl of 5×RM (NaCl concentration: 500 mM) and 5 μl of BamHI were added to it. 35 μl of distilled water were further added so as to cause complete dissolution of the precipitate, and the solution was then incubated at 37° C. for an hour. After phenol extraction and chloroform treatment, DNA precipitated with ethanol was dissolved into 10 μl of TE.
Then, pUR290 DNA (1 μl) digested with HindIII and BamHI was mixed with pNLH402 DNA (1 μl) digested with HindIII and BglII and 2 μl of 10×ligation buffer and 1 μl of T4DNA ligase were added. A total volume of 20 μl was achieved with distilled water, and reaction was caused at 15° C. for 12 hours. Escherichia coli strain UT481 (Journal of Bacteriology, 163: 376-387, 1985) was transformed with the reaction liquid in accordance with the above-mentioned calcium chloride method. Ampicillin resistant colonies were selected on an LB medium plate containing 20 μg/ml ampicillin, and furthermore, a clone containing fragments of about 3.8 kb originating from pNL4-3 was selected by measuring the size of the inserted fragment by EcoRI cleavage. Clone UT481/pPG280 was thus obtained. More specifically, in this clone the approximately 3.8 kb HIV pol gene region is considered to be ligated to the 3' end of lacZ gene of plasmid pUR290, and the lacZ and pol gene product is initially expressed as a fusion protein (about 230 kd), the various separate enzymes being produced after processing.
(EXAMPLE 2)
Production of lentiviral protease, reverse transcriptase and integrase enzymes by culture of transformed cells: After culturing transformed cell clone UT481/pPG280 at 37° C. for 18 hours in an LB medium containing 20 μg/ml ampicillin (1 W/V% Bactotrypton, 0.5 W/V% Bacto-yeast extract and 1 W/V% NaCl), the resultant cells were added to fresh LB medium containing 20 μg/ml ampicillin at 1:100 dilution and the pre-culture was carried out. When the OD600 mm of the medium reached 0.5, 1 mM IPTG (Isopropyl-β-D-thiogalactopyranoside, made by Sigma [U.S.A.]) was added, and culture was continued at 25° C. for 18 hours. Bacteria were collected by centrifugation (5,000 rpm for five minutes) and suspended in 1/25 volume of 40 mM tris-HCl (pH 8.0) (0.1 mM EDTA, 5 mM MgCl 2 , 0.1 W/V% Triton X-100 and 10 mM 2-mercaptoethanol). After ultrasonic treatment (five 30-second bursts, 19.5 kHz, 300 W), the supernatant liquid was separated by centrifugation (19,000 rpm, 60 minutes). To confirm the presence of HIV pol gene product in this crude extraction liquid, the activity of the reverse transcriptase in the crude extraction liquid was measured. The result is shown in FIG. 1. The expected significant activity of the reverse transcriptase was observed. Analysis by the Western blot technique was also carried out: 4 W/V% sodium dodecyl sulfate (SDS) and 1 W/V% 2-mercaptoethanol were added to the collected bacteria. After boiling for five minutes and centrifugation (10,000 rpm for five minutes), the supernatant liquid was electrophoresed on a 0.1 W/V% SDS--10 W/V% polyacrylamide gel. After blotting onto a nitrocellulose membrane (made by S&S [West Germany]) by means of transblotting apparatus (made by BioRad [U.S.A.]), the membrane was immersed in 3 W/V% gelatin solution in accordance with the conventional blocking method. Then, as a primary reaction the membrane was incubated with human serum obtained from an HIV carrier, and after washing, as a secondary reaction was caused with peroxidase marker conjugated anti-human IgG antibody (made by BioRad). Finally, after washing, the membrane was immersed in a chromogenic liquid prepared by adding 0.4 ml of DAB (3,3'-diaminobenzidine tetrahydrochloride) and 15 μl of 30 W/V% hydrogen peroxide solution to 50 ml of TBS (20 mM tris-HCl [pH 7.4], 500 mM NaCl), to cause color formation, at room temperature for 15 minutes, and was then washed with distilled water. The result is shown in FIG. 2. While no specific band reacting with human HIV carrier serum was observed in the crude extraction liquid of the transformed cell UT481/pUR290 based on the vector pUR290 not carrying an HIV pol gene, bands of reverse transcriptase having a molecular weight of 66 kd and 51 kd, integrase of 32 kd, and protease of 12 kd, i.e. the HIV pol gene products, were observed in the extraction liquid of transformed cells of strain UT481/pPG280. Cleavage of the reverse transcriptase from β-galactosidase is easily determined from the results of column chromatography with anion exchanger MonoQ (made by Pharmacia [Sweden]) as shown in FIG. 3. More particularly, the reverse transcriptase activity can be found in a fraction completely separated from β-galactosidase activity. This suggests that, although HIV pol gene products are produced as fusion proteins with β-galactosidase, protease, reverse transcriptase, and integrase regions of that fusion protein are specifically separated by the action of the protease which is itself a pol gene product, and accumulated in the cell.
(EXAMPLE 3)
Construction of a vector to enable the production of large amounts of lentiviral protease: 5 μl of HindIII and 10 μl of 5×RM were added to 5 μg of DNA of the pol gene expression plasmid pPG280 prepared in Example 1, and the mixture was diluted with distilled water to a total volume of 100 μl. The mixture was incubated at 37° C. for an hour, and after phenol extraction and chloroform treatment, the mixture was subjected to ethanol precipitation. The resultant precipitation was added to 5 μl of 5×RM (-NaCl) and 5 μl of BalI and was diluted with distilled water to a total volume of 50 μl, whereby the precipitate was sufficiently dissolved. The mixture was incubated again at 37° C. for an hour, and after phenol extraction and chloroform treatment, the resulting product was subjected to ethanol precipitation. The resulting precipitation was added to 5 μl of 10×polymerase buffer (670 mM Tris HCl [pH 8.8], 67 mM MgCl 2 , 166 mM (NH 4 ) 2 SO 4 , 100 mM 2-mercaptoethanol and 67 μM EDTA), 5 μl of 10×dNTP solution (each 3.3 mM of dATP, dGTP, dTTP, and dCTP) and 1 μl T4 DNA polymerase and was diluted with distilled water to a total volume of 50 μl, whereby it was sufficiently dissolved. The mixture was incubated at 37° C. for 15 minutes, and after phenol extraction and chloroform treatment, the resulting product was subjected to ethanol precipitation. To the mixture of 1 μl of the solution prepared by dissolving the resultant precipitation into 10 μl of TE and 2 μl of 10×ligation buffer, 1 μl of T4 DNA ligase was further added and total volume was brought up to 20 μl with distilled water. The mixture was further incubated at 15° C. for 12 hours. Escherichia coli strain UT481 was transformed with this reaction liquid in accordance with the above-mentioned calcium chloride method. Ampicillin resistant colonies were selected on an LB medium plate containing 20 μg/ml ampicillin, and furthermore, a clone containing 0.55 kb fragment originating from pNL4-3 was selected by measuring the size of the inserted fragment using EcoRI digestion. Clone UT481/pLB550 -3 was thus obtained.
(EXAMPLE 4)
Mass production of lentiviral protease by transformed cells: After culturing transformant clone UT481/pLB550-3 at 37° C. for 18 hours in LB medium (containing 20 μg/ml ampicillin), the resulting cells were added to fresh LB medium (containing 20 μg/ml ampicillin) at 1:100 dilution and the pre-culture was carried out at 37° C. When the OD600 nm of the medium reached 0.5, 1 mM IPTG (Isopropyl β-D-thiogalactopyranoside, Sigma [U.S.A.]) was added, and culture was continued at 37° C. for 6 hours. Bacteria were collected by centrifugation (5,000 rpm for five minutes), and 4 W/V% sodium dodecyl sulfate (SDS) and 1 W/V% 2-mercaptoethanol were added. After boiling for five minutes and centrifugation (10,000 rpm for five minutes), the supernatant liquid was electrophoresed on a 0.1 W/V% SDS--15 W/V% polyacrylamide gel. Subsequently, the collected bacteria were analyzed by means of the Western blot technique described in Example 2. While no specific band reacting with human HIV carrier was observed in the crude extracts of UT481/pUR290, bands of 12 kb protease serum were observed in the extracts liquid of UT481/pLB550-3. Especially, pLB550-3 produced an amount of protease several times as much as pPG280. In this clone, 0.55 kb HIV pol gene is considered to be ligated to the 3' end of lacZ gene of plasmid pUR290, and the lacZ--pol gene product is estimated to be produced as a fusion protein with molecular weight of about 140 kb, and a protease of about 12 kb being produced after processing.
(EXAMPLE 5)
Construction of an expression vector carrying oncoviral protease and pol gene: 5 μg of plasmid pSRA2 DNA carrying Rous sarcoma virus cDNA (Journal of Virology, 36, pp. 50-61, 1980) was added with 5 μl of BamHI and 20 μl of 5×RM, and was diluted with distilled water to a total volume of 100 μl, which was then incubated at 37° C. for an hour. After this reaction, the mixture was electrophoresed on a 1 W/V% agarose gel having a low melting point, and the gel portion containing a 1.8 kb DNA fragment was digested. Then, after phenol extraction and chloroform treatment, the resulting product was subjected to ethanol precipitation. To the mixture of 1 μl of the solution prepared by dissolving the precipitation into 10 μl of TE, 0.1 μg (1 μl) of plasmid pUR291 DNA cleaved by BamHI and treated with alkaline phosphatase, and 2 μl of 10×ligation buffer, 1 μl of T4 DNA ligase was further added and the total volume was brought up to 20 μl with distilled water. The reaction mixture was incubated at 15° C. for 12 hours. Subsequently, Escherichia coli strain UT481 was transformed with this reaction mixture in accordance with the calcium chloride method, and ampicillin resistant colonies were selected on an LB medium plate containing 20 μg/ml ampicillin. Plasmid DNA was extracted from the ampicillin resistant clone using a conventional method, and a clone pSR281 was obtained by selecting a clone containing a 1.8 kb fragment originating from plasmid pSRA2 and producing a LacZ-Gag fusion protein.
5 μg of plasmid pSRA2 DNA was added to 5 μl of PstI and 20 μl of 5×RM (750 mM NaCl), and was diluted with distilled water to a total volume of 100 μl, which was then incubated at 37° C. for an hour. After this reaction, the mixture was electrophoresed on a 1 W/V% agarose gel having a low melting point, a 1.8 kb DNA fragment was digested. Then, after phenol extraction and chloroform treatment, the resulting product was subjected to ethanol precipitation and dissolved to 10 μl of TE. Similarly, the double-stranded phage DNA of M13mp18 was cleaved by PstI and treated with alkaline phosphatase. A 1 μl (0.1 μg) of this DNA was added to 1 μl of 3.1 kb DNA fragment mentioned above, 2 μl of 10×ligation buffer and 1 μl of T4 DNA ligase, and was diluted with distilled water to total volume of 100 μl, which was then incubated at 15° C. for 12 hours. Subsequently, the recombinant phage DNA was used to transfect Escherichia coli strain TG1 following the calcium chloride method, and a plaque was formed on a 2YT medium plate (1.6 W/V% Bacto-trypton, 1 W/V% Bacto-yeast extract, 0.5 W/V% NaCl and 1.5 W/V% Bacto-agar) containing an X-gal (5-brom-4-chloro-3-indolyl-β-D-galactopyranoside, Sigma [U.S.A.]).
Next, the TG1 strain was propagated in a 2YT medium (1.6 W/V% Bacto-trypton, 1 W/V% Bacto-yeast extract, and 0.5 W/V% NaCl) until the OD600 nm of the medium reached 0.3, and some of the achromatic clone of the resultant plaque were inoculated. Each single- and double-stranded DNA was prepared in accordance with a conventional method after continuing to incubate for several hours. A clone M13sr31 which contains a 3.1 kb fragment originating from pSRA2 was selected by digesting the obtained double-stranded DNA with PstI and BamHI. The 3.1 kb fragment originating form pSRA2 encodes the 3' end of gag gene, the termination codon TAG, and the pol gene. The insertion of one base before the termination codon results in the expression of a gag-pol fusion gene having matching translating frames. Thus by using an in vitro mutagenesis kit (made by Amersham [England]), a clone M13sr32 was obtained, containing the sequence ATAG obtained by inserting one base before the termination codon TAG on the M 13sr31.
5 μg of double-stranded DNA of M13sr32 was added to 5 μl of Pst1 and 20 μl of 5×RM, and was diluted with distilled water to total volume of 100 μl, which was then incubated at 37° C. for an hour. After this reaction, the mixture was electrophoresed on a 1 W/V% agarose gel having a low melting point, and a gel containing a 3.1 kb DNA fragment was digested. Then, after phenol extraction and chloroform treatment, the resulting product was subjected to ethanol precipitation. To the mixture of 1 μl of the solution prepared by dissolving the precipitation into 10 μl of TE, 1 μl (0.1 μg) of plasmid pSR281 DNA digested by PstI and treated with alkaline phosphatase, and 2 μl of 10×ligation buffer, 1 μl of T4 DNA ligase were further added and the total volume was brought up to 20 μl with distilled water. Then, the mixture was incubated at 15° C. for 12 hours. Subsequently, Escherichia coli UT481 strain was transformed with this reaction mixture in accordance with the calcium chloride method, and ampicillin resistant colonies were selected on an LB medium plate containing 20 μg/ml ampicillin. Plasmid DNA was extracted from the ampicillin resistant clone by a conventional method, and the presence and direction of the 3.1 kb fragment originating from M13sr32 were confirmed by digesting the plasmid by PstI and BamHI, and then a clone UT481/pSR271 which was assumed to express protease and pol gene products was obtained.
Incidentally, the thus obtained clone UT481/p5R271 carries a total of 3.6 kb DNA derived from pSRA2, because the 1.3 kb region of pSR281 which overlaps the 31. kb region of M13 sr 32 was removed by Pst I cleavage.
(EXAMPLE 6)
Production of oncoviral protease, reverse transcriptase and integrase enzymes by culture of transformed cells: After culturing transformant clone UT481/pSR271 at 37° C. for 18 hours in an LB medium (containing 20 μg/ml ampicillin), the resultant cells were added to fresh LB medium (containing 20 μg/ml ampicillin) at 1:100 dilution and the pre-culture was carried out. When the OD600 nm of the medium reached 0.5, 1 mM IPTG was added, and culture was continued at 25° C. for 18 hours. Bacteria were collected by centrifugation (5,000 rpm for five minutes) and suspended in 1/25 volume of 40 mM tris-HCl (pH 8.0) (0.1 mM EDTA, 5 mM MgCl 2 , 0.1 W/V% Triton X-100 and 10 mM 2-mercaptoethanol). After ultrasonic treatment (five 30-second bursts, 19.5 kHz, 300 W), the supernatant was separated by centrifugation (19,000 rpm, 60 minutes). To confirm the presence of RSV gene product in this crude extraction liquid, the activity of the reverse transcriptase in the crude extraction liquid was measured. The expected significant activity of the reverse transcriptase was observed. Analysis by the Western blot technique was also carried out: 4 W/V% sodium dodecyl sulfate (SDS) and 1 W/V% 2-mercaptoethanol were added to the collected bacteria. After boiling for five minutes and centrifugation (10,000 rpm for five minutes), the supernatant was electrophoresed on a 0.1 W/V% SDS--15 W/V% polyacrylamide gel. After blotting onto a nitrocellulose membrane (made by S&S [West Germany]) using transblotting apparatus (made by BioRad [U.S.A.]), the membrane was immersed in 3 W/V% gelatin solution in accordance with the conventional blocking method. Then, as a primary reaction, the membrane was incubated with anti-RSV rabbit serum, and after washing, as a secondary reaction was incubated with peroxidase marker conjugated anti-rabbit IgG antibody (made by BioRad). Finally, after washing, the membrane was immersed in a chromogenic liquid prepared by adding 0.4 ml of DAB (3.3'-diaminobenzidine tetrahydrochloride) and 15 μ of 30 W/V% hydrogen peroxide solution to 50 ml of TBS (20 mM tris-HCl [pH 7.4] , 500 mM NaCl), to cause color formation, at room temperature for 15 minutes, and was then washed with distilled water. While no specific band reacting with anti-RSV rabbit serum was observed in the crude extraction liquid of the transformed cell UT481/pUR290 based on the vector pUR290 not having the RSV gene, bands of RSV reverse transcriptase were observed in the extraction liquid of UT481/pSR271. Although RSV protease and the pol gene product are produced as a fusion protein with β-galactosidase, proteases and reverse transcriptase regions are specifically separated by the action of the protease which is itself a gag gene product, and are estimated to be accumulated in the cell. In the clone UT481/pSR271, the 3.6 kb Rous sarcoma virus gag and pol gene region is considered to be ligated to the 3' end of lacZ gene of plasmid pUR291, and it is suggested that the lacZ, gag and pol gene products are expressed as a fusion protein (about 230 kb), which is then processed to liberate the enzymes e.g. protease (P15), reverse transcriptase (P92, P65) and integrase (P32).
(EXAMPLE 7)
Extraction of reverse transcriptase: As mentioned above in Example 2, transformed Escherichia coli clone UT481/pPG280 was cultured in 91 LB medium (containing 20 μg/ml ampicillin) at 25° C., and when the culture reached an OD600 nm of 0.5, 1 mM IPTG was added. Culture was further continued for another 24 hours, and after collection, the cells were suspended in 120 ml of 40 mM tris-HCl (pH 8.0) (containing 0.1 mM EDTA, 5 mM MgCl 2 , 0.1 W/V% Triton X-100 and 10 mM 2-mercaptoethanol) buffer. Bacterial cells were crushed by ultrasonic treatment and subjected to centrifugation (19,000 rpm for 60 minutes), and the supernatant was separated as the crude extraction liquid.
(EXAMPLE 8)
Purification of reverse transcriptase: Polymine P (made by BRL [U.S.A.]) was added in an amount of 0.1 W/V% to the crude extraction liquid, which was then stirred at 4° C. for 30 minutes and centrifuged (16,000 rpm for 20 minutes).
Ammonium sulfate was added to the supernatant. The precipitate produced from this 40% saturated solution was removed by centrifugation (16,000 rpm for 20 minutes) and 137 ml of supernatant liquid was obtained. Ammonium sulfate was added again to 80% saturation, and the thus produced precipitate was dissolved in 50 ml of the above-mentioned 40 mM tris-HCl buffer and was then dialyzed against same buffer containing 50 mM NaCl.
(EXAMPLE 9)
High grade purification of reverse transcriptase: High grade purification was carried out using DEAE Bio-Gel A (made by BioRad [U.S.A.]) and Affi-Gel Heparin column chromatography (made by BioRad). The dialyzed sample of Example 8 was applied to a 30 ml DEAE Bio-Gel A column equilibrated with 40 mM tris-HCl (pH 8.0) (containing 0.1 mM EDTA, 5 mM MgCl 2 , 0.1 W/V% Triton X-100, 10 mM 2-mercaptoethanol and 50 mM NaCl). The eluted sample was then applied to a 30 ml Affi-Gel Heparin column equilibrated with the above-mentioned buffer and was eluted with 150 ml buffer comprising a sodium chloride gradient of from 50 mM to 400 mM. The result is shown in FIG. 4. Fractions 29 to 38 containing reverse transcriptase activity were pooled. The thus pooled reverse transcriptase fractions were dialyzed against 20 mM sodium phosphate buffer (pH 6.8) (containing 0.1 mM EDTA, 5 mM MgCl 2 , 0.1 W/V% Triton X-100 and 10 mM 2-mercaptoethanol) and were further purified by the use of hydroxylapatite column (KB column, made by Koken [Japan]) by high-performance liquid chromatography. More particularly, after adsorption of the above-mentioned dialyzed specimen onto the column, elution was carried out with a linear gradient of sodium phosphate of 20 to 400 mM, and fractions containing reverse transcriptase activity were pooled. Thus, purified reverse transcriptase was obtained. The thus obtained reverse transcriptase was confirmed, by the use of SDS-PAGE, to have a purity of over 95%. The yield was 31% relative to the crude extraction liquid.
(EXAMPLE 10)
Diagnosis of HIV-1 infection using purified reverse transcriptase: The purified reverse transcriptase (protein concentration 250 μg/ml) prepared according to Example 9 was electrophoresed on a polyacrylamide gel in accordance with Example 2, and was blotted onto a nitrocellulose membrane. The membrane was then immersed in a 3 W/V% gelatin solution for blocking. Subsequently, the presence of an antibody against the HIV-1 reverse transcriptase was investigated in the sera of human HIV-1 carriers (3 subjects) using the Western blot technique. Human T-cell leukemia virus (HTLV-1) carriers (5 subjects) and healthy adults (5 subjects) were similarly investigated. The result in shown in Table 1. The sera of all 3 HIV-1 carriers reacted to reverse transcriptase (66 kd and 51 kd). However, none of the sera of the HTLV-1 carriers (which belongs to the same retrovirus family as HIV-1), nor the sera from the 5 healthy subjects did so. This suggests that it is possible to make a specific diagnosis of the presence of HIV-1 infection by using the purified HIV-1 reverse transcriptase prepared from Escherichia coli according to the present invention.
TABLE 1______________________________________Diagnosis of HIV-1 infection by Western blotting,using the purified reverse transcriptase.Subjects Reactivity______________________________________human serum of HIV-1 carrier1 + * *2 +3 +human serum of HTLV-1 carrier1 -2 -3 -4 -5 -human serum of healthy adult1 -2 -3 -4 -5 -______________________________________ * Specific immunological reaction against purified reverse transcriptase * * Reactivity was measured by the Western blot technique. Shown are positive (+) and negative (-) reaction.
EFFECT OF THE INVENTION
(1) In the method of the present invention, in which a very dangerous retrovirus itself is not used, high safety is available from the point of view of biohazards under the production conditions, and operation is easy.
(2) The method of the present invention provides a very high production yield of each of the enzymes produced as present by an amount of protein of from 1 to 10 mg per liter of bacteria culture.
(3) According to the present invention, in spite of the retroviral protease, reverse transcriptase and integrase are expressed as a fusion protein with high expressing ability, various enzymes can be produced, not in the form of fusion protein, but in the form of single matured proteins which had been processed respectively. The method is thus more efficient and rational than that using the expression of single enzyme genes, and taking account of the effects (1) and (2) above, is more economical.
(4) Since enzymes having a very high specificity relative to the substrate unique to retroviruses and enzymes as antigen to retroviruses are available at a low cost in a large quantity, the method of the present invention brings about great progress in fundamental research on and diagnosis of retrovirus infectious diseases such as AIDS, adult T cell leukemia, avian sarcoma or leukemia, and feline leukemia, and facilitates development of specific therapeutic drugs and preventive drugs having a high selectivity, thus providing a boon to human health and promotion of stock breeding.
(5) The method of the present invention can be applied to development of the efficient and rational mass production of the foregoing gene products, for this method makes it possible to cause mass expression of various other genes contained in the said virus and retrotransposon, as well as of various retrovirus enzyme genes. | Disclosed is a method for producing retroviral proteins which are protease,everse transcriptase and endonuclease. The method is characterized by the consecutive expression and processing of retroviral genes by the stepwise cultivation of hosts transformed with a vector constructed to carry retroviral gene fragments comprising at least a protease gene and one or more of the other genes coding for retroviral proteins. The retroviral proteins of this invention are used as specific reagents for the diagnosis of retroviral disease, e.g., AIDS, malignant tumors and so forth, also may be used as the basis for research and development of antiviral agents and a vaccine against the above infectious diseases, and for genetic engineering. | 2 |
BACKGROUND
[0001] In drilling and completion industries such as hydrocarbon exploration and production, Carbon Dioxide sequestration, etc., tools are often run into the downhole environment for particular purposes requiring locating the tool at a target position. Traditionally an operator will keep track of a length of tubing in the hole and anticipate the specific tool at issue locating upon a feature within the hole. The feature may be a seat, profile, bottom, etc. Such “gauging” of where the tool is occurs in trips into the borehole, trips out of the borehole and movements of the tool in defined areas of the borehole.
[0002] For example, an operation in a borehole may require several actions taking place between a downhole most location and an uphole most location for the particular operation. Providing profiles at these locations will provide a guide to the operator to keep the target tool in the target location for the job being done.
[0003] While such measures are currently used, tools do not always engage profile properly and effective indication of position at the surface may not be received. Such situations result in lost time, which translates to cost increases.
[0004] In order to address the foregoing, a downhole position locating device with fluid metering feature (U.S. Pat. No. 7,284,606, the entirety of which is incorporated herein by reference) was developed. Such a tool or others that function by providing a fluid movement component of their operation, which fluid component has an effect on tool operation such as in the ‘606 patent wherein the fluid delays an action until the fluid is removed by exhaustion or by movement to another chamber are useful as landing in a sought profile is better verifiable by a pull or push from surface that allows for a slower movement of the string. While the concept generally works well, there is a possibility that the tool experiences restricted movement due to friction, Blow Out Preventer (BOP) contact or other impediments rather than due to an engagement with a profile and fluid movement. In such case, the indication of tool location at surface would be inaccurate. Since accuracy in downhole operations improves efficiency and reduces costs, the industry will well receive improved arrangements supporting these goals.
SUMMARY
[0005] A downhole tool with a feedback arrangement including a tool having one or more fluid outflow ports that exhaust fluid during normal operation of the tool; and a feedback arrangement in operable communication with the fluid exhausted from the one or more fluid outflow ports during operation of the tool, the feedback arrangement interacting with exhausting fluid to produce a signal receivable at a remote location indicative of proper tool operation.
[0006] A method for confirming operation of a downhole tool including disposing an oscillator within a fluid outflow path; actuating the tool thereby causing fluid to flow in the outflow path; affecting the oscillator with the fluid; and creating a signal with the oscillator representative of tool operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Referring now to the drawings wherein like elements are numbered alike in the several Figures:
[0008] FIGS. 1A-C is a representation of one embodiment of a metering tool with feedback arrangement in three distinct positions;
[0009] FIGS. 2A-C is a representation of another embodiment of a metering tool with feedback arrangement in three distinct positions; and
[0010] FIG. 3 is a plan view of an embodiment of a pulser.
DETAILED DESCRIPTION
[0011] It is to be appreciated that while the overall configuration of the metering tool of the ‘606 patent is utilized to illustrate two embodiments of the disclosed invention, other configurations where fluid movement is a part of the function of the tool will also benefit from the embodiments providing feedback as described herein.
[0012] Referring to FIGS. 1A-C , a metering tool 10 is generally depicted with a feedback arrangement including an oscillator 12 . In this embodiment the oscillator is a spring mass that is positioned within a fluid outflow through outflow port(s) 14 caused by metering of the metering tool 10 . It is to be understood that although a spring mass is illustrated as oscillator 12 , any mass that can be caused to oscillate due to fluid flow can be used. As will be appreciated from a review of the metering tool in the incorporated by reference ‘606 patent, fluid is exhausted during the normal operation of the tool 10 . Because of the placement of the oscillator 12 , the fluid flow through outflow port(s) 14 interacts with the oscillator to cause the oscillator to oscillate. Oscillation of the oscillator produces a signal that can be received at remote locations and is indicative of proper tool operation. Different forms of oscillation can be transmitted to remote locations for reliable feedback of the operation of the tool. In this case, the spring mass, which may be a coil spring as shown, oscillates against the tool itself creating vibration that is transmitted through a string 16 supporting the tool back to surface or other remote location. The vibration is detectable at the remote location by hand or sensor or auditorily and confirms proper operation of the tool in the downhole environment.
[0013] In another embodiment, referring to FIGS. 2A-C , a metering tool 10 with a feedback arrangement includes a pulser 20 mounted proximate a fluid outflow through the outflow port(s) 14 of the tool 10 . Upon fluid outflow, the pulser arrangement will rotate. The pulser, in one embodiment is hence a rotating member. Rotation of the pulser is due to one or more (four shown) openings 22 in the pulser 20 that are configured angularly relative to an axis of the rotatable pulser. Rotation of the pulser 20 results in an alternating pattern of openings and solid sections of the pulser aligning with the fluid outflow of the tool 10 . This alternatingly allows fluid passage and fluid blockage (or at least inhibition). Accordingly, pressure within the fluid downstream of the pulser changes alternatingly at the same rate that the pulser rotates. Pressure downstream of the pulser decreases when fluid flow is inhibited and returns to system pressure with each alignment of the openings 22 . More particularly, when one of the openings (or more of them if there are more fluid outflow ports or if the pulser is configured to align more than one of the openings with the fluid outflow (in the event that the fluid outflow is broader in area than one of the openings 22 plus an adjacent solid portion of the pulser 20 ) is aligned with the fluid outflow, the pressure downstream of the pulser is the same as it is upstream of the pulser. When the pulser rotates to a position where the fluid flow from the outflow port(s) is blocked or inhibited, the pressure in the fluid downstream of the pulser dips. The dip in pressure and subsequent recovery of system pressure can be received and in some cases might actually be measured a substantial distance from the pulser 20 and tool 10 . The pressure change is embodied as an acoustic signal propagating through fluid in the borehole and provides feedback at a remote location or at the surface of fluid outflow from the outflow port(s). Depending upon the length of time a particular tool has a fluid outflow, the acoustic signal may have time to reach a remote location such as the surface to be perceived or the signal may act as a post actuation confirmatory signal. This is because an appreciable amount time is required for signal propagation in a fluid medium. And while clearly the time factor for signal propagation in a fluid medium is directly related to the density of that fluid, (and of course distance is a factor in overall travel time) in virtually all cases of fluid borne acoustic signals from downhole tools, it will be likely that the actuation time causing the fluid outflow will be less than the transit time for the signal hence making such signals confirmatory.
[0014] While the foregoing embodiment provides one method for propagating a signal based upon the structure shown, there is another that provides for much less of a time delay. This utilizes the actual work string the tool is disposed in to propagate a vibratory signal. Because the pulser, in addition to what it does as noted above, will also cause pressure variations in the tool that is exhausting fluid, the string itself experiences varying strain that is cyclic. A cyclic change in tensile strain can function as a signal. More specifically, and using the metering tool of the ‘606 patent as an example, as the tool contacts a locating profile, applied tension displaces fluid through the outflow ports and past the pulser. The flow of fluid rotates the pulser thereby restricting and unrestricting the flow of liquid through the ports. This variance in restriction results in a variance of the pressure within the tool chamber. The variance in chamber pressure in the tool will be manifested as a variance in force between the metering tool and the profile. This force variation is detectable as a variance in tensile force in the workstring upon which the tool has been run and operated. The signal provides increased confidence that the tool 10 is operating properly. One benefit of this embodiment is the speed at which a signal will propagate through metal as opposed to a fluid. In view of this speed increase, the signal is received virtually contemporaneously with the tool actuation.
[0015] While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation. | A downhole tool with a feedback arrangement including a tool having one or more fluid outflow ports that exhaust fluid during normal operation of the tool. A feedback arrangement in operable communication with the fluid exhausted from the one or more fluid outflow ports during operation of the tool. The feedback arrangement interacting with exhausting fluid to produce a signal receivable at a remote location indicative of proper tool operation. A method for confirming operation of a downhole tool is included. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to heat exchange in a u-tube heat exchanger designed to operate in critical process conditions such as high temperatures, large temperature differences, high pressure differences and aggressive mediums. More particularly, the invention relates to a u-tube waste heat boiler and more particularly to a synthesis gas waste heat boiler with water or steam as cooling medium.
[0002] In the following the present invention will be explained in relation to a waste heat boiler with synthesis gas as the heating medium and water or steam as the cooling medium. It is to be understood that the heat exchanger according to the present invention also applies to waste heat boilers for other heating and cooling mediums or even to other areas of heat exchanging with challenging operating conditions where due care is to be taken against material damage without unacceptable high pressure losses in the heat exchanger.
[0003] Industrial production of ammonia is based on the ammonia synthesis process by which hydrogen and nitrogen are reacted to ammonia in an exothermic process. Ammonia synthesis is performed in a reactor at high pressure and elevated temperature, when nitrogen and hydrogen is flowing through a bed with an appropriate catalyst. Such a reactor is called an ammonia converter. The heat produced by the exothermic process in the converter is often recovered by steam production in a synthesis gas waste heat boiler. The synthesis gas waste heat boiler is a heat exchanger in which the hot gas from the ammonia converter is cooled by indirect heat transfer to boiling water.
[0004] The synthesis gas waste heat boiler is operating at challenging conditions which in many ways require a special design of the boiler. The most severe conditions are related to inlet gas tube to tube sheet joins.
[0005] In the heat exchanger according to the invention, there are no inlet gas tube to tube sheet joints. Further, the tube sheet as well as the tube sheet joints is only exposed to the heating medium after it has been cooled. Therefore, most of the causes for boiler failure are avoided by the design according to the present invention.
BACKGROUND OF THE INVENTION
[0006] A heat exchanger such as a synthesis gas waste heat boiler is subject to a number of special conditions, which are difficult to account for by combination in one design.
[0007] These conditions are related to the pressure, temperature, nitriding, hydrogen attack and stress corrosion.
[0008] The ammonia synthesis gas will typically be at a pressure of 120-220 bar. The boiling water will typically be at low (5-15 bar), medium (30-50 bar) or high pressure (90-130 bar). Separation walls between synthesis gas and boiling water must be designed for the highest pressure difference of the two fluids. In shell and tube heat exchangers this will normally result in a very thick tube sheets usually with a thickness of 300-450 mm.
[0009] The ammonia synthesis gas can be between 380° C. and 500° C. at the inlet to the boiler and between 200° C. and 380° C. at the outlet. The boiling water can be between 150° C. and 330° C., depending on the steam pressure.
[0010] Synthesis gas waste heat boilers are often designed as u-tube exchangers with a very thick tube sheet. The thick tube sheet will obtain a metal temperature which is close to the gas temperature of the sheet penetrating tubes. In case of u-tubes, this will in known art imply that the inlet tube area will be hot where as the outlet tube area will be cold. High thermal induced stresses are therefore a risk, if the temperature difference between inlet and outlet gas is too high. In case of low and medium pressure steam production is it desirable if a temperature difference of 200° C. to 300° C. could be acceptable. It has however in know art shown difficult or impossible to design a u-tube waste heat boiler for such a big temperature difference.
[0011] Nitriding is a materials attack caused by the ammonia content of the synthesis gas. The severity of nitriding depends on the metal alloy and the metal temperature. Low alloy steels are attacked unacceptably at 380° C. Stainless steel can be used to 450° C. or higher and Iconell will not be severely attacked even at 500° C. The inlet-tube area of the tube sheet in a U-tube boiler will often be hotter than 420° C. The materials, in contact with the synthesis gas must therefore be high alloy. A surface protection by cladding or lining will be required on the gas side of the tube sheet and through the inlet-hole surface.
[0012] Hydrogen attack will cause embrittlement in materials when exposed to hydrogen containing gasses. The important parameters are the hydrogen partial pressure, the temperature and the alloying elements of the steel. 2% Cr and 1% Mo steel alloy will typically be required by industrial synthesis gas composition, pressure and temperature.
[0013] Stress corrosion is a risk for the materials in connection with the water. This kind of corrosion is however not critical by ferritic materials, whereas austenitic materials are sensitive to this kind of attack. The typical synthesis gas waste heat boiler is a U-tube heat exchanger with synthesis gas on the tube side and water/steam on the shell side. The tube sheet is very thick. The inlet side of the tube sheet is protected by Inconell cladding. If the tubes are welded to the gas side of the tube sheet, the tubes must be lined on the inner surface with Inconell all the way through the tube sheet. If the tubes are welded to the waterside of the tube sheet, the inlet holes of the tube sheet must be protected by an Inconell lining.
[0014] Synthesis gas waste heat boilers often fail due to cracks caused by one or a combination of the described mechanical and/or corrosion phenomena. The most severe conditions among these are concentrated around the inlet tube holes. That is due to the high temperature, the temperature difference between inlet and outlet tubes, stress corrosion, hydrogen build up between materials of different composition, nitriding and hydrogen attack. Another aspect of the Synthesis Gas boiler is the pressure drop of the synthesis gas through the exchanger, which have to be kept low due to considerations of power/energy consumption of the synthesis gas compressor.
[0015] In U.S. Pat. No. 3,568,764 a u-tube heat exchanger is disclosed where a baffle is provided adjacent to the outlet side of the tube sheet of the multiple tube pass heat exchanger. A portion of the cold input fluid is passed between the baffle and the tube sheet, rather than through the tubes, so that the tube sheet is maintained at a substantially uniform and cold temperature. Ferrules pass the heated outlet gas portions from the tubes to the outlet chamber of the channel. The heat exchange efficiency is however lowered due to the portion of input fluid which by-passes the heat exchange tubes. The heating fluid is on the shell side of the exchanger, which is contrary to present invention where the cooling fluid is on shell side.
[0016] In EP 0860673 a solution to the above problems is disclosed by a fire tube heat exchanger with a plurality of heat exchanging tubes, wherein the heat exchanging tubes are in form of a double tube with an outer tube closed at one end and an open ended inner tube spaced apart from the outer tube, adapted to exchange heat between a hot gas on tube side of the outer tube and a fluid on shell side of the tube. Though solving the above mentioned problems, this solution has however a considerable pressure drop on tube side compared to an U-tube exchanger, which renders the solution more expensive due to expenses in relation to increased heat exchange surface for a given pressure drop.
SUMMARY OF THE INVENTION
[0017] An object of this invention is to avoid the drawbacks of the known art heat exchangers in particular known waste heat boilers by providing a u-tube heat exchanger with a fair heat transfer, material deterioration resistance and low pressure drop.
[0018] This is achieved by a heat exchanger according to the following features of the present invention.
features of the invention
[0000]
1. A u-tube heat exchanger for heat exchanging a heating medium with a cooling medium, the heat exchanger comprising
a cooling medium chamber with an inlet and an outlet a heating medium inlet chamber with an inlet a heating medium outlet chamber with an outlet a tube sheet with a plurality of tube sheet holes, the tube sheet separates the cooling medium chamber on a first side from the heating medium outlet chamber on the second side a plurality of heat exchange u-tubes having a first and a second end a plurality of inlet tubes having an inlet and an outlet end, each inlet tube corresponds to one of the u-tubes an inlet tube plate arranged so that it separates the heating medium inlet chamber from the heating medium outlet chamber, the inlet tube plate has a plurality of inlet tube plate holes
said plurality of heat exchange u-tubes are arranged in the tube sheet with said first and second end connected to the circumference of a tube sheet hole each, the u-tubes extend within the cooling medium chamber in contact with the cooling medium on the shell side of the u-tubes, and said plurality of inlet tubes are arranged in the inlet tube plate with the inlet end connected to the circumference of an inlet tube plate hole each, wherein the outlet end of each of the inlet tubes is arranged partly within the first end of a corresponding heat exchange u-tube, the outside diameter of each inlet tube is smaller than the inside diameter of the corresponding heat exchange u-tubes first end in at least the part of each u-tube wherein the corresponding inlet tube is arranged within, the only fluid connection between the heating medium inlet chamber and the tube sheet and the inside of the u-tubes are via the fluid passage of the inlet tubes, whereby both the first and the second end of the u-tubes as well as the tube sheet are in contact with only the cooled heating medium on the tube side of the u-tubes and the tube sheet.
[0027] 2. A u-tube heat exchanger according to feature 1, wherein the cooling medium is water or steam, synthesis gas or process gas.
[0028] 3. A u-tube heat exchanger according to any of the preceding features, wherein the heat exchanger is a waste heat boiler and the cooling medium is water or steam.
[0029] 4. A u-tube heat exchanger according to any of the preceding features, wherein the heat exchanger is a synthesis gas waste heat boiler and the heating medium is synthesis gas.
[0030] 5. A u-tube heat exchanger according to any of the preceding features, wherein the cooled heating medium exiting the first end of each of the plurality of u-tubes has a temperature substantially equal to the cooled heating medium exiting the second end of each of the plurality of u-tubes.
[0031] 6. A u-tube heat exchanger according to any of the preceding features, wherein the temperature difference between the cooled heating medium exiting the first end of each of the plurality of u-tubes and the cooled heating medium exiting the second end of each of the plurality of u-tubes is in the range of 0° C.-50° C., preferably in the range of 0° C.-20° C.
[0032] 7. A u-tube heat exchanger according to any of the preceding features, wherein at least the part of the plurality of inlet tubes arranged within a corresponding u-tube is thermally insulated.
[0033] 8. A u-tube heat exchanger according to any of the preceding features, wherein there is an annulus between the part of each of the inlet tubes arranged within the first end of a corresponding heat exchange u-tube and the corresponding heat exchange u-tubes first end.
[0034] 9. A u-tube heat exchanger according to any of the preceding features, wherein the plurality of inlet tubes are not in contact with the plurality of u-tubes.
[0035] 10. A u-tube heat exchanger according to any of the preceding features wherein the diameter of the second end of each of the u-tubes is smaller than the diameter of the first end of said u-tube.
[0036] 11. A process for heat exchanging a heating medium with a cooling medium in a u-tube heat exchanger according to feature 1, the process comprising the steps of
a) providing a flow of the cooling medium via the cooling medium inlet into the cooling medium chamber, where the cooling medium contacts the shell side of the u-tubes, and out of the cooling medium chamber via the cooling medium outlet, b) providing a flow of the heating medium to the heating medium chamber via the heating medium inlet, c) providing the flow of the heating medium further through the holes of the inlet tube plate into the inlet tubes inlet ends, further through the inlet tubes and out of the inlet tubes outlet ends and into each of the corresponding u-tubes in a distance from said u-tubes first end, d) splitting the heating medium flow in each of the u-tubes in a first part flow which flows through a first part of each u-tube in the annulus between the inlet tube and the u-tube before the first part flow exits each u-tube via the first end and a second part flow which flows through a second part of each u-tube and exits each u-tube via the second end, both the first and the second part flow is in indirect heat-exchange with the cooling medium via the u-tubes walls and is cooled by the cooling medium while it flows through the u-tubes collecting all the cooled heating medium flows in the heating medium outlet chamber where the cooled heating medium is in contact with the tube sheets second side and further providing a flow of the cooled heating medium out of the heating medium outlet chamber via the heating medium outlet.
[0041] 12. A process for heat exchanging a heating medium with a cooling medium according to feature 11, wherein the cooling medium is water or steam.
[0042] 13. A process for heat exchanging a heating medium with a cooling medium according to feature 11 or 12, wherein the cooling medium inlet temperature is in the range of 100° C.-350° C., preferably in the range of 250° C.-325° C., the cooling medium outlet temperature in the range of 100° C.-350° C., preferably in the range of 250° C.-325° C., the heating medium inlet temperature is in the range of 300° C.-500° C., preferably in the range of 390° C.-450° C., and the heating medium outlet temperature in the range of 120° C.-390° C., preferably in the range of 300° C.-370° C.
[0043] 14. A process for heat exchanging a heating medium with a cooling medium according to any of the features 11-13, wherein the temperature difference between each of the first part cooled heating medium flows and the second part cooled heating medium flows is in the range of 0° C.-50° C., preferably in the range of 0° C.-20° C. when exiting the first and the second end of each of the u-tubes into the heating medium outlet chamber.
[0044] 15. Use of a heat exchanger according to any of the features 1-10 for heat exchanging water or steam with synthesis gas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The present invention will be discussed in more detail with reference to the specific embodiments in the drawings which relate to a waste heat boiler heat exchanger:
[0046] FIG. 1 is a cross section view of an embodiment of a waste heat boiler according to the invention, and
[0047] FIG. 2 is a cross section view of a u-tube detail in an embodiment of a waste heat boiler according to the invention.
REFERENCE NUMBERS
[0048] 101 ) Tube sheet
[0049] 102 ) Tube sheet holes
[0050] 103 ) Heat exchange u-tubes
[0051] 104 ) Inlet tubes
[0052] 105 ) Inlet tube plate
[0053] 106 ) cooling medium side pressure shell
[0054] 107 ) cooling medium chamber
[0055] 108 ) cooling medium inlet nozzle
[0056] 109 ) cooling medium outlet nozzle
[0057] 110 ) Heating medium side pressure shell
[0058] 111 ) Heating medium chamber
[0059] 112 ) Heating medium inlet chamber
[0060] 113 ) Heating medium outlet chamber
[0061] 114 ) Heating medium inlet nozzle
[0062] 115 ) Heating medium outlet nozzle
[0063] 116 ) Inlet tube insulation
DETAILED DESCRIPTION OF THE INVENTION
[0064] The tube sheet ( 101 ) is on one side connected to the cooling medium side pressure shell ( 106 ) (e.g. water/steam) and on the other side connected to the heating medium side pressure shell ( 110 ) and forms the separation between the cooling medium chamber ( 107 ) and the heating medium chamber ( 111 ) (e.g. synthesis gas). The tube sheet is perforated with a number of tube sheet holes ( 102 ). The heat exchange u-tubes ( 103 ) are welded to the tube sheet ( 101 ) at both ends of the u-tubes in the tube sheet holes ( 102 ). The heat exchange u-tubes ( 103 ) extend into the cooling medium chamber ( 107 ). An inlet tube plate ( 105 ) is placed inside the heating medium chamber ( 111 ). The inlet tube plate ( 105 ) is perforated with holes corresponding to the holes in the tube sheet ( 101 ). Inlet tubes ( 104 ) with an outer diameter smaller than the inner diameter of the heat exchange u-tubes ( 103 ) are fixed to the holes of the inlet tube plate ( 105 ) and extend into the inside of the heat exchange u-tubes ( 103 ). The inlet tube plate ( 105 ) is connected to the heating medium nozzle ( 114 ) by means of plates and shells forming a gas tight heating medium inlet chamber ( 112 ). The inlet tubes ( 104 ) are covered with an inlet tube insulation layer ( 116 ).
[0065] A cooling media as e.g. boiling feed water from a steam drum is flowing into the cooling medium chamber ( 107 ) through the cooling medium inlet nozzle ( 108 ). The heat exchange u-tubes ( 103 ) are supplying heat for boiling in the cooling medium chamber ( 107 ). A mixture of water and steam is leaving the cooling medium chamber ( 107 ) through the cooling medium outlet nozzles ( 109 ). A heating medium as e.g. hot synthesis gas from an ammonia converter enters into the heating medium inlet chamber ( 111 ) through the heating medium inlet nozzle ( 114 ). The synthesis gas then flows through the holes of the inlet tube plate ( 105 ), through the inlet tubes ( 104 ) into the heat exchange u-tubes ( 103 ). In each heat exchange u-tube a first part of the synthesis gas flow is changing flow direction, returning in the u-tubes in the annulus, outside of the inlet tubes ( 104 ) and inside the heat exchange u-tubes ( 103 ), back to the heating medium outlet chamber ( 113 ). A second part of the synthesis gas flow in each heat exchange u-tube flows further on to the u-bend of the u-tube and flows to the heating medium outlet chamber ( 113 ). The synthesis gas then leaves the heat exchanger through the heating medium outlet nozzle ( 115 ).
[0066] When the synthesis gas is flowing in the annulus between the inlet tube ( 104 ) and the heat exchange u-tube ( 103 ) it is cooled while it is transferring its heat by indirect heat transfer to the boiling water. Heat transfer between the inlet gas, flowing inside the inlet tubes ( 104 ) and the gas flowing in the annulus is avoided by means of the inlet tube insulation layer ( 116 ).
[0067] The characteristic benefit of the heat exchanger according to the invention is that the thick tube sheet ( 101 ) will only come in contact with the cooled outlet synthesis gas. The problems experienced with synthesis gas waste heat boilers as described above related to the hot inlet gas and the temperature difference between tubes in the thick tube sheet is thereby minimized. The inlet tube plate ( 105 ) of the invention is thin because it is a non pressure part and it can be made of austenitic high alloy steel because it is not in contact with the water. The heat exchanger according to the invention has a reduced pressure drop as compared to blind tube heat exchangers as the gas stream is split in two when leaving the inlet tubes. The pressure drops and heat transfer coefficients of the first and the second gas streams flowing through a first and a second part and outlet of the u-tubes can be equilibrated in such a way that the synthesis gas temperature will be similar at both the u-tubes outlet ends. This may in one embodiment be done by reducing the diameter of the second end of the u-tubes as seen in FIG. 2 . | A u-tube heat exchanger has inlet tubes arranged in a pressure neutral inlet tube plate, a heating medium flows via the inlet tubes into u-tubes arranged in a tube sheet where the medium splits in two and flows from both ends of the u-tubes into a heating medium outlet chamber and exits the heat exchanger via an outlet nozzle. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a dry cleaning machine using a solvent as a detergent and preventing contamination of the washing caused conversely by washing.
[0003] 2. Description of the Related Art
[0004] FIG. 5 is showing a constitutional block diagram of a dry cleaning machine by prior art.
[0005] In FIG. 5 , a drum-formed washing tank 1 is for washing the washing by rotating drum, throwing the washing into the drum tank, supplying a detergent (tetrachloroethylene or the like). The contaminated detergent after using is stored in a lower tank 2 . This detergent is sent into a filtering tank 4 and forwarded to a refining tank 5 by a pressure pump 3 . In the refining tank 5 , the detergent is refined to remove odors, acids and colors with filters, activated carbon and the like and then returned into the drum tank 1 to be reused.
[0006] In the dry cleaning machine shown in FIG. 5 , washing power of the detergent is remarkably sunk by cyclical use, even though the contaminated detergent is refined in the refining tank. Therefore, in a conventional dry cleaning machine, a detergent collecting unit as shown in FIG. 6 is appended. In this detergent 25 collection unit, the heavy contaminated detergent in the washing tank 1 is sent into a distiller 6 . The contaminated detergent in the distiller 6 is heated to vaporize the detergent and other moisture and the vaporized gas is forwarded to a condenser 7 . The vaporized gas in the condenser 7 is liquefied by chiller water and is separated to detergent and water through a water separator 8 . The detergent is sent to a collection tank 9 and the separated water is sent to a separated water tank 10 . The detergent collected in the collection tank 9 is forwarded to the washing tank 1 to be used.
[0007] On the other hand, a dry cleaning machine has washing property as shown in FIG. 7 . The washing property in FIG. 7 shows phenomena of contaminator dissolving into the detergent and the washing property curve (a) shows contamination is maximized in a short time and is going down slowly after the peak. Thus, in the washing property, the detergent contamination becomes the maximum roughly at one minute and 30 seconds after starting, slightly depending on the washing type or contaminator type. In FIG. 7 , the vertical axis indicates detergent contamination and the horizontal axis indicates washing time.
[0008] The dry cleaning machine, shown in FIG. 5 , uses cyclically refined detergent to send the contaminated detergent through a filtering tank and a refining tank. Owing to the detergent contamination becomes the maximum in a short time, shown in FIG. 7 , there is apprehension to contaminate the washing conversely by washing. In addition, the detergent filtering in the filtering tank works well just after the dry cleaning machine running, but, as increasing washing cycle number, some waste threads, dirty oil or other dirt in the detergent stick on a filter and clog up the filter. When clogging up the filter, filtering efficiency is rapidly sinking and a volume of detergent flowing is going down. As washing performance cannot be kept if the volume of detergent flowing goes down, in general, increasing the detergent pressure in the filtering tank to keep the volume of detergent flowing maintains the washing performance of the dry cleaning machine. That, however, cannot solve the issue of contaminating the washing conversely by washing. Furthermore, there is apprehension that increasing detergent pressure in the filtering tank damages the filtering tank or the refining tank easily and then it possibly contaminates the washing by supplying contaminated detergent to the washing tank
[0009] Even if reusing detergent distilled by the distiller shown in FIG. 6 , the detergent contamination becomes the maximum in a short time after washing starting because of no deference on washing property of the dry cleaning machine shown in FIG. 7 . There are still issues of contaminating the washing conversely by washing and bad hygiene.
SUMMARY OF THE INVENTION
[0010] This invention has been accomplished to overcome the above drawbacks and an object of this invention is to avoid contaminating the washing conversely by contaminated detergent and provide a dry cleaning machine and method of dry cleaning, solving hygienic issues.
[0011] In order to attain the objects, according to an aspect of this invention, in a dry cleaning machine including a detergent tank to store detergent, a washing tank and a filtering tank to treat used detergent, wherein the treated detergent is sent back to the washing tank for cyclical use, there is provided the dry cleaning machine comprising of detecting means for detecting contamination level of the detergent discharged from the washing tank while washing, storing means for storing the used detergent when the contamination level of detergent reaches prescribed threshold level and distilling means for distilling the used detergent, whereby fresh detergent is supplied from the detergent tank to the washing tank.
[0012] In the dry cleaning machine mentioned above, before the detergent contamination becomes the maximum in a short time from starting washing the washing, the detergent channel is switched from washing tank-to-filtering tank to washing tank-to-contaminated detergent tank. During switching the detergent channel as mentioned above, fresh detergent is supplied to the washing tank and it can solves an issue to contaminate the washing conversely by contaminated detergent.
[0013] Advantageously, in the above machine, wherein detecting the contamination level of the detergent in a channel from the filtering tank to the washing tank, when the contamination level indicate an abnormal value, shutting the channel and storing temporarily the detergent from the filtering tank and distilling the detergent by the distiller.
[0014] In the machine, when detecting an abnormal value of contamination level of the detergent passed through the filtering tank, the detergent is distilled in the distiller after stored temporarily and reused. Then, rapid clogging up the filtering tank can be solved and cyclically use of the detergent can be worked.
[0015] Preferably, a dry cleaning machine, comprising of a washing tank for washing the washing by detergent supplied from a detergent tank, a filtering tank for refining contaminated detergent discharged from the washing tank and supplying the refined detergent to the washing tank, a contamination detector for detecting contamination level of detergent after used in the washing tank, a contaminated detergent tank for storing contaminated detergent temporarily while shutting detergent supplying channel from the washing tank to the filtering tank when the contamination level is over prescribed threshold level, a distiller to distill the contaminated detergent from the contaminated detergent tank and a condenser for condensing vaporized contaminated detergent in the distiller and sending the condensed detergent to the detergent tank.
[0016] In the dry cleaning machine mentioned above, by detecting contamination level of the detergent discharged from the washing tank with the contamination detector, the detergent channel from the washing tank to the filtering tank is switched to the contaminated detergent tank and the detergent is stored there, before the detergent contamination becomes the maximum in a short time after starting washing. After that, the contaminated detergent is sent to the distiller and vaporized in the distiller. The vaporized gas is forwarded to the condenser and condensed by chiller water and reused as refined detergent.
[0017] Advantageously, the dry cleaning machine mentioned above, wherein the second detector is mounted in a channel to supply detergent from the filtering tank to the washing tank for detecting the detergent contamination level in the channel.
[0018] In this dry cleaning machine, the detergent contamination, after the filtering tank, can be detected by the second detector mounted there. In the other word, when the detergent contamination after the filtering tank increasing, it makes definition of some damages in the filter occurred and supplying the detergent from the filtering tank to the washing tank can be stopped and then contaminating the washing conversely by washing can be prevented.
[0019] Advantageously, the all dry cleaning machines mention above, wherein the detector for detergent contamination level is of an image processing means, such a CCD camera or the like, to sense the detergent contamination level.
[0020] In these all dry cleaning machines, as the detector for detergent contamination is a CCD camera, it cannot sense only the detergent contamination but also a lot of waste threads mixed in the detergent. Therefore, it can prevent rapid clogging up the filtering tank.
[0021] In order to attain the objects, according to an aspect of this invention, there is provided a method of dry cleaning comprising the steps of supplying the washing and detergent to wash the washing in a washing tank, detecting detergent contamination level just after washing while treating used detergent in a filtering tank and reusing the detergent in the washing tank and shutting the detergent supply to the filtering tank and supplying fresh detergent to the washing tank to prevent the detergent contamination level is over prescribed threshold level when the detergent contamination level reaches prescribed threshold level.
[0022] In this cleaning method, contaminating the washing conversely by washing can be prevented as detecting the detergent contamination level discharged from the washing tank during washing. Then, the detergent can be used by circulating and also reused by distiller.
[0023] Advantageously, the cleaning method mentioned above, wherein the contamination level of detergent, supplied from the filtering tank to the washing tank, is detected and above channel from the filtering tank to the washing tank is closed to shut the detergent supply when the contamination level indicates an abnormal value.
[0024] In the cleaning method, contaminating the washing conversely by washing can be prevented and also the filtering tank damage can be detected because contamination level of the detergent transmitted from the filtering tank to the washing tank is detected. As a matter of course, when detecting rapidly increased contamination of the detergent, it is defined to occur some damages on the filter and then indicating or warning of the filter damage can urge to replace filter of the filtering tank.
EFFECT OF INVENTION
[0025] As mentioned above, according to this invention, the dry cleaning machine detects detergent contamination discharged from a washing tank then if the contamination level goes over prescribed value, stores the contaminated detergent in a contaminated detergent tank temporarily and supplies fresh detergent to the washing tank to prevent contaminating the washing conversely by washing. Therefore, the dry cleaning machine can use circulating detergent and clean the washing to supply clean detergent always not contaminating the washing to the washing tank.
[0026] According to this invention, the dry cleaning machine can prevent to contaminate the washing conversely by washing as cutting off the line to supply detergent from a filtering tank to a washing tank and supplying fresh detergent to the washing tank when detecting the contamination of detergent supplied from the filtering tank to the washing tank. Then, this is an excellent hygienic cleaning method.
[0027] According to this invention, the dry cleaning machine can detect reducing the light transmittance caused by darkened detergent with contamination as taking images of the detergent discharged from the washing tank by CCD camera. Moreover, advantageously the dry cleaning machine can prevent immoderate clogging of the filtering tank as judging abnormal condition by processing the image data even if a lot of waste thread or down mix into the detergent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a constitutional block diagram, showing one embodiment of a dry cleaning machine according to this invention;
[0029] FIG. 2A, 2B are sectional views of examples of contamination detectors;
[0030] FIG. 3 is a graph and timing charts to explain the cleaning method which prevents contaminating the washing conversely by washing to detect detergent contamination in a dry cleaning machine according to this invention;
[0031] FIG. 4 is a graph and timing charts to explain the cleaning method which prevents contaminating the washing conversely by washing to detect detergent contamination supplied from the filtering tank in a dry cleaning machine according to this invention;
[0032] FIG. 5 is a block diagram to explain a dry cleaning machine by prior art;
[0033] FIG. 6 is a block diagram to explain a dry cleaning machine by prior art;
[0034] FIG. 7 is a graph to explain washing property of a dry cleaning machine;
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] Some embodiments of dry cleaning machines and cleaning methods according to this invention will now be described with reference to the attached drawings.
[0036] FIG. 1 is showing a block diagram of one embodiment of a dry cleaning machine according to this invention. In FIG. 1 , a washing tank 10 is a shower drum type for washing the washing and preferably soaking type, shower type or jet type is effective and also combination type of these types is effective. A detergent tank 11 stores detergent and a rinse tank 12 stores rinse. Washing is done after inputting the washing and detergent (tetrachloroethylene or the like) into the washing tank 10 . The detergent for initial use can be supplied directly through fresh detergent line L 1 to the washing tank 10 or can also be supplied through circulating line L 3 , L 4 .
[0037] The detergent, discharged from the washing tank 10 , is sent by pressure to the filtering tank 16 through a detergent discharging line L 2 , next a button trap 13 and next a circulating line L 3 having a circulation pump P 1 in the line. The detergent after the filtering tank 16 is supplied to the washing tank 10 through a circulating line 4 . The detergent, discharged from the washing tank 10 , is monitored on contamination level by a contamination detector D 1 , mounted in the detergent discharging line L 2 . The detergent, supplied from the filtering tank 16 to the washing tank 10 , is monitored by a contamination detector D 2 , mounted in the circulating line L 4 . By way of the contamination detectors D 1 , D 2 , a CCD camera, a couple of light emitting elements and light receiving elements or a module of reflective millers and a couple of light emitting elements and light receiving elements or the like is used.
[0038] This dry cleaning machine includes of a distiller 14 for distilling contaminated detergent to reuse the detergent, a condenser 15 for condensing gas vaporized in the distiller 14 and a contaminated detergent tank 17 for storing the contaminated detergent temporarily. The detergent to the distiller 14 is supplied through the button strap 13 or the contaminated detergent tank 17 .
[0039] Switch valves V 3 , V 6 are mounted in the circulating line L 3 , wherein a contaminated detergent returning line L 5 is branched off. The contaminated detergent returning line L 5 , wherein switching valves V 8 , V 9 are mounted, is connected to the contaminated detergent tank 17 . The contaminated detergent tank 17 is connected to the distiller 14 by the contaminated detergent returning line L 6 , wherein a switching valve V 10 is mounted. Furthermore, the distiller 14 is connected to the condenser 15 by a vaporized gas sending line L 7 . The condenser 15 is connected to the detergent tank 11 by a condensed liquid sending line L 8 , for supplying condensed and liquefied detergent in the condenser 15 to the detergent tank 11 .
[0040] A control unit 20 including CPU, provided in the dry cleaning machine, receives data output from the contamination detectors D 1 , D 2 and controls the switching valves V 1 to V 10 with processing the data from the contamination detectors D 1 , D 2 .
[0041] In the next, the contamination detectors D 1 , D 2 will be described with reference to FIGS. 2A and 2B . As the contamination detectors D 1 D 2 have the same structure, only the, contamination detector D 1 will be described herein. In FIG. 2A , the contamination detector D 1 is mounted in the detergent discharging line L 2 or the circulating line L 4 . A CCD camera 23 and a light emitting element 21 , as the contamination detector D 1 , are placed opposite to each other sandwiching a transparent pipe 22 in the middle. The light emitting element 21 , the transparent pipe 22 and the light receiving section of the CCD camera 23 are covered with a shade material 24 to cut off external light into the transparent pipe 22 . Further, in FIG. 2B , the contamination detector D 1 is mounted in the detergent discharging line L 2 or the circulating line L 4 . The light emitting element 21 and a light receiving element 25 , as the contamination detector D 1 , are placed opposite to each other sandwiching a transparent pipe 22 in the middle. The light emitting element 21 , the transparent pipe 22 and the light receiving element 25 are covered with a shade material 24 to cut off external light into the transparent pipe 22 . The contamination detector D 1 is mounted by connecting the detergent discharging line L 2 or the circulating line L 4 on the both end of the contamination detector D 1 .
[0042] Preferably, the light emitting element 21 is placed at the same side of the CCD camera 23 or the light receiving element 25 to detect the detergent contamination by taking a image of the reflective light or receiving the reflective light, instead of placing the light emitting element 21 opposite to the CCD camera 23 or the light receiving element 25 .
[0043] In the next, working of the contamination detectors D 1 , D 2 in FIG. 2A will be described with reference to FIGS. 1, 2A . The light, radiated from the light emitting element 21 , irradiates the detergent flowing in the transparent pipe 22 through the transparent pipe 22 . The light, passing the detergent, is sensed by the CCD camera 23 . The image data from the CCD camera 23 is inputted to the control unit 20 and judged whether over or under the prescribed threshold level on each pixel. The image data on each pixel is defined as digital signal “ 1 ” for over the prescribed threshold level and digital signal “ 0 ” for under the prescribed threshold level. And then, judgement whether over the threshold level or not is done by total sum of all digital signals of each pixel of the image and defines “1” for over the threshold level and “0” for under the threshold level. When the judgement of total sum is “1”, the detergent contamination is defined to reaches the prescribed level. Thus, as the detergent contamination is defined numerically and the contamination is detected by total sum of each pixel digital signals, on the situation of detergent contamination mixed with a lot of waste thread or down waste the detection can be done.
[0044] The contamination detectors D 1 , D 2 in FIG. 2B will be described here. The contamination detectors D 1 , D 2 are mounted in the detergent discharging line L 2 or the circulating line L 4 . The light from the light emitting element 21 is received by the light receiving element 25 through the transparent pipe 22 . The output of the light receiving element 25 depends on light transmittance changing caused by the detergent contamination level and indicates the smaller transmitted light power the more detergent contamination. Then, the control unit 20 judges “1” by output from the contamination detectors D 1 , D 2 when the output of the light receiving element 25 reaches the prescribed level.
[0045] If the contamination detectors D 1 , D 2 in FIG. 2B are mounted in the circulation line L 4 , it can detect to supply the contaminated detergent to the washing tank 10 or can judge to occur the filter damage in the filtering tank 16 . Setting low detecting level (threshold level) for detergent contamination, damage of the filtering tank can be detected earlier and contaminating the washing conversely by washing can be solved. Preferably, inputting the output of the contamination detector D 2 into the control unit 20 and monitoring time-dependent change of detergent contamination change, the filter damage of the filtering tank 16 can be detected by rapid change of the detergent contamination.
[0046] In the next, a dry cleaning method to prevent contaminating the washing conversely by washing in a dry cleaning machine according to this invention will be described with reference to FIGS. 1, 3 and 4 . In FIG. 3 -A shows washing property curves (a), (b) and FIG. 3 -B shows working condition of the circulating pump P 1 and FIGS. 3 -C, D, E and F show each working condition of switching valves V 3 , V 6 and V 7 , V 8 and V 9 , V 2 and V 2 .
[0047] On this embodiment of dry cleaning machines, the switching valves V 3 , V 6 , V 7 are opened and the switching valves V 8 , V 9 are closed in starting operation. As the switching valves V 4 , V 5 are opened in certain level, the detergent and rinse are mixed to be usable. The mixed detergent is supplied from the filtering tank 16 to the washing tank 10 through the circulating line L 3 by operating the circulating pump P 1 . By rotating the drum of the washing tank 10 , washing the washing is started. The contamination level of the detergent, discharged from the washing tank 10 , is detected by the contamination detector D 1 . The output of the contamination detector D 1 is inputted into the control unit 20 . As shown in FIG. 3 -A, the property shows the detergent contamination becomes the maximum in a short time (time T 2 ) after starting washing. Therefore, eliminating the maximum peak, when the output of the contamination detector D 1 goes over the prescribed threshold level (time T 1 ), the switching valves V 6 , V 7 are closed as shown in FIG. 3D to cut off the circulating line L 3 from the washing tank 10 to the filtering tank 16 and the circulating line L 4 from the filtering tank 16 to the washing tank 10 . In the other hand, the switching valves V 8 , V 9 in the detergent returning line L 5 are opened as shown in FIG. 3 -E.
[0048] In the next, when the switching valves V 6 , V 7 are closed and the switching valves V 8 , V 9 in the contaminated detergent return line L 5 are opened, the contaminated detergent is supplied to the contaminated detergent tank 17 through the contaminated detergent return line L 5 . In the meantime, the switching valves V 1 , V 2 is opened and detergent, mixed by the detergent and rinse from the detergent tank 11 and the rinse tank 12 , is supplied directly to the washing tank and the washing is washed. After passing the prescribed time (the time between T 1 and T 2 in FIG. 3 -A is required time that detergent contamination is changing from the prescribed threshold level to the maximum), the switching valves V 6 , V 7 are opened and the switching vales V 8 , V 9 and V 1 , V 2 are closed. Then the initial condition is set again. The contaminated detergent, sent to the contaminated detergent tank 17 , is forwarded at suitable intervals to the distiller 14 through the contaminated detergent return line L 6 . The contaminated detergent is heated and vaporized in the distiller 14 and the vaporized gas of the contaminated detergent is forwarded to the condenser 15 to be condensed and liquefied by chiller water. The liquefied detergent is sent to the detergent tank 11 through the condensed detergent transport line L 8 .
[0049] Thus, the control unit 20 can improve the washing property like Washing property curve as shown in FIG. 3 -B, for supplying fresh detergent directly to the washing tank by controlling each switching vales, sending control signals to each switching valve before the detergent contamination becomes the maximum. Then, contaminating the washing conversely by washing can be solved and cyclically use of the detergent can be worked.
[0050] In the next, prevention to contaminate the washing conversely caused by filer damage of the filtering tank in a dry cleaning machine will be described with reference to FIG. 4 . The curve (b) in FIG. 4 -A shows the washing property curve by the operation method to prevent above conversely contamination. The curve (c) in FIG. 4 -A shows contaminated detergent leaking when the filter of the filtering tank is damaged. Solving to contaminate the washing conversely by such filter damage, the contamination detector D 2 is mounted in the circulating line L 4 from the filtering tank 16 to the washing tank 10 .
[0051] The contamination detector D 2 is detecting the contamination level of detergent flowing in the circulating line L 4 . When the output of the contamination detector D 2 is over the prescribed threshold level (in the condition as shown in FIGS. 4 -A, C), the switching valve V 7 is closed and the switching valve V 9 is opened as shown in FIGS. 4 -D, F. Then, the detergent passed through the filtering tank 16 is sent to the contaminated detergent tank 17 . In the meantime, the switching valves V 1 , V 2 are opened as shown in FIG. 4 -G and fresh detergent is supplied to the washing tank 10 through fresh detergent line L 1 and this condition is kept until washing finished. The switching valves V 6 , V 8 are kept as shown in FIGS. 4 -C, E. The contamination level of the detergent, discharged from the washing tank 10 , is detected by the contamination detector D 1 as shown in FIG. 3 -A. When the detergent contamination level is over the prescribed threshold level, the switching valves V 6 , V 7 is closed to cut off the circulating line L 4 from the washing tank 10 to the filtering tank 16 and the switching valves V 8 , V 9 , mounted in the contaminated detergent return line L 5 , are opened to send the contaminated detergent to the contaminated detergent tank 17 .
[0052] On the other hand, the switching valve V 10 , mounted in the contaminated detergent return line L 6 , is opened and the contaminated detergent in the contaminated detergent tank 17 is forwarded to the distiller 14 . The vaporized gas by heating and vaporizing the contaminated detergent in the distiller 14 is sent through the vaporized gas transport line L 7 to the condenser 15 to be condensed and liquefied by chiller water. The liquefied detergent is returned to the detergent tank 11 through the condensed detergent transport line L 8 .
[0053] Detecting the contamination of the detergent from the filtering tank 16 and controlling as mentioned above can give the washing property as shown in FIG. 4 -D. In addition, as the filter in the filtering tank 16 can be exchanged after washing the washing finished, the maintenance of the filtering tank is made easy. Preferably, in case of detecting abnormal condition by the contamination detector D 2 , indicating or alarming filter damage, then stopping operation temporarily, then exchanging filter in the filtering tank 16 , then restarting operation is effective.
[0054] Preferably, instead of detecting the detergent contamination by inputting image data by a CCD camera continuously to the control unit, detecting both of image data by a CCD camera and output signal by a light receiving element and inputting the data and the signal to the control unit to sense the detergent contamination is also effective.
[0055] Advantageously, a dry cleaning machine having only one contamination detector D 1 can solve issue to contaminate the washing conversely by washing. Mounting the second contamination detector D 2 in the dry cleaning machine can prevent more effectively contaminating the washing conversely by washing. | The object is to avoid contaminating the washing conversely by contaminated detergent and provide a dry cleaning machine and dry cleaning method, solving hygienic issues.
In a dry cleaning machine which supplies detergent from a detergent tank 11 to a washing tank 10 and washes the washing in the washing tank 10 and treats detergent used in the washing tank 10 by a filtering tank 16 and sends the treated detergent to the washing tank 10 to use detergent cyclically, wherein contaminating the washing conversely by washing can be prevented, as detecting contamination level of detergent discharged from the washing tank 10 while supplying detergent to the washing tank 10 and washing the washing, and when the detergent contamination level reached a prescribed threshold level, storing the detergent discharged from the washing tank 10 temporarily and sending the detergent to a distiller 14 and supplying fresh detergent from the detergent tank 11 to the washing tank 10. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. patent application Ser. No. 11/557,273, filed Nov. 7, 2006, and U.S. Provisional Patent Application Ser. No. 60/807,165 filed on Jul. 12, 2006, both of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
The present application relates in general to accounting systems and more specifically to methods and apparatus for analyzing revenue cycles of a facility.
BACKGROUND
The finances of facilities have become more complex in recent years. Accountants have difficulty tracking the financial status of facilities due to a number of factors. For instance, computer networks allow accountants greater access to data more immediately than in the past. As a result, accountants and those planning the finances of facilities sometimes find themselves faced with an overwhelming amount of data and unable to categorize it. Subsequently, it is often difficult to make meaningful conclusions based on the available data.
Some accountants and financial planners have turned to general accounting systems to resolve some of these issues. However, general accounting systems often only aggregate data and do not provide certain analysis. Having data collected in one view is helpful, but it can still be difficult to determine what the data represents. Additionally, general accounting systems provide a snapshot of the current financial state of a facility but lack certain tools useful in forecasting and identifying financial opportunities or weaknesses.
Some accountants and financial planners use accounting systems that provide them with regular reports as to financial performance. However, the accounting systems typically fail to accurately predict future financial performance. Also, the reports are often not timely and it is difficult to make immediate decisions that would improve financial performance.
SUMMARY
The present disclosure provides methods and apparatus for analyzing the revenue cycles of a facility to more accurately predict future financial performance. Using the methods and apparatus disclosed herein, accountants and financial planners are given forecasts of future accounts paid based on current accounts receivable and past accounts paid.
Additional features are described herein, and will be apparent from the following detailed description of the figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a high level block diagram of a communications system.
FIG. 2 is a more detailed block diagram showing one example of a client device.
FIG. 3 is a more detailed block diagram showing one example of a server.
FIG. 4 is a flowchart of an example process to calculate a net receivable.
FIG. 5 is a diagram illustrating an example screen for displaying net receivable values.
FIG. 6 is a diagram illustrating an example screen displaying user choices for displaying net receivable values.
FIG. 7 is a diagram illustrating an example screen displaying an account receivable entry.
FIG. 8 is a diagram illustrating an actual realization amount.
FIG. 9 is a diagram illustrating a net receivable value.
FIG. 10 is a diagram illustrating a high level fluctuation threshold.
FIG. 11 is a diagram illustrating an unapplied discount account.
FIG. 12 is a diagram illustrating an expected reserve value.
DETAILED DESCRIPTION
The present system is most readily realized in a network communications system. A high level block diagram of an exemplary network communications system 100 is illustrated in FIG. 1 . The illustrated system 100 includes one or more accounting terminals 102 , one or more facility terminals 104 , one or more accounting servers 106 , and one or more databases 108 . Each of these devices may communicate with each other via a connection to one or more communications channels 110 such as the Internet or some other data network, including, but not limited to, any suitable wide area network or local area network. It will be appreciated that any of the devices described herein may be directly connected to each other instead of over a network.
The accounting server 106 stores a plurality of files, programs, and/or web pages in one or more databases 108 for use by accounting terminals 102 and/or the facility terminals 104 . The database 108 may be connected directly to the accounting server 106 and/or via one or more network connections. The database 108 stores financial information, including, but not limited to, accounts receivable information, accounts paid information, realization rates, etc. For example, database 108 may store account information regarding a client of a facility. The facility may includes any number of branches, franchises, sales offices, etc. For example, the facilities may include hospitals, treatment centers and service centers.
One accounting server 106 may interact with a large number of terminals. Accordingly, each server 106 is typically a high end computer with a large storage capacity, one or more fast microprocessors, and one or more high speed network connections. Conversely, relative to a typical server 106 , each accounting terminal 102 or facility terminal 104 typically includes less storage capacity, a single microprocessor, and a single network connection.
A more detailed block diagram of an accounting terminal 102 or facility terminal 104 is illustrated in FIG. 2 . The accounting terminal 102 or facility terminal 104 may include a personal computer (PC), a personal digital assistant (PDA), an Internet appliance, a cellular telephone, or any other suitable communication device. The accounting terminal 102 or facility terminal 104 preferably includes a main unit 202 which preferably includes one or more processors 204 electrically coupled by an address/data bus 206 to one or more memory devices 208 , other computer circuitry 210 , and one or more interface circuits 212 . The processor 204 may be any suitable processor, such as a microprocessor from the INTEL PENTIUM® family of microprocessors. The memory 208 preferably includes volatile memory and non-volatile memory. Preferably, the memory 208 stores a software program that interacts with the other devices in the system 100 as described below. This program may be executed by the processor 204 in any suitable manner. The memory 208 may also store digital data indicative of documents, files, programs, web pages, etc. retrieved from an accounting server 106 and/or loaded via an input device 214 .
The interface circuit 212 may be implemented using any suitable interface standard, such as an Ethernet interface and/or a Universal Serial Bus (USB) interface. One or more input devices 214 may be connected to the interface circuit 212 for entering data and commands into the main unit 202 . For example, the input device 214 may be a keyboard, mouse, touch screen, track pad, track ball, isopoint, and/or a voice recognition system.
One or more displays, printers, speakers, and/or other output devices 216 may also be connected to the main unit 202 via the interface circuit 212 . The display 216 may be a cathode ray tube (CRTs), liquid crystal displays (LCDs), or any other type of display. The display 216 generates visual displays of data generated during operation of the accounting terminal 102 or facility terminal 104 . For example, the display 216 may be used to display web pages received from the accounting server 106 . The visual displays may include prompts for human input, run time statistics, calculated values, data, etc.
One or more storage devices 218 may also be connected to the main unit 202 via the interface circuit 212 . For example, a hard drive, CD drive, DVD drive, and/or other storage devices may be connected to the main unit 202 . The storage devices 218 may store any type of data used by the accounting terminal 102 or facility terminal 104 .
The accounting terminal 102 or facility terminal 104 may also exchange data with other network devices 220 via a connection to the network 110 . The network connection may be any type of network connection, such as an Ethernet connection, digital subscriber line (DSL), telephone line, coaxial cable, etc. Users of the system 100 may be required to register with the accounting server 106 . In such an instance, each user may choose a user identifier (e.g., e-mail address) and a password which may be required for the activation of services. The user identifier and password may be passed across the network 110 using encryption built into the user's browser. Alternatively, the user identifier and/or password may be assigned by the accounting server 106 .
A more detailed block diagram of a accounting server 106 is illustrated in FIG. 3 . Like the accounting terminal 102 and facility terminal 104 , the main unit 302 in the accounting server 106 preferably includes a one or more processors 304 electrically coupled by an address/data bus 306 to a memory device 308 and a network interface circuit 310 . The network interface circuit 310 may be implemented using any suitable data transceiver, such as an Ethernet transceiver. The processor 304 may be any type of suitable processor, and the memory device 308 preferably includes volatile memory and non-volatile memory. Preferably, the memory device 308 stores a software program that implements all or part of the method described below.
In particular, the memory preferably stores an accounting calculation module 312 and a display module 314 . The accounting calculation module 312 performs the necessary calculations to the financial data as described below. The display module is configured to aid in displaying the financial data to the account terminal 102 and facility terminal 104 . These software modules may be executed by the processor 304 in a conventional manner. However, some of the steps described in the method below may be performed manually or without the use of the accounting servers 106 . The memory device 308 and/or a separate database 312 also store files, programs, web pages, etc. for use by other accounting servers 106 , accounting terminals 102 or facility terminals 104 .
A flowchart of an example process 400 for analyzing revenue cycles is presented in FIG. 4 . Preferably, the process 400 is embodied in one or more software programs which is stored in one or more memories and executed by one or more processors. Although the process 400 is described with reference to the flowchart illustrated in FIG. 4 , it will be appreciated that many other methods of performing the acts associated with process 400 may be used. For example, the order of many of the steps may be changed, and some of the steps described may be optional.
In this example, the process 400 receives a first account receivable value (block 402 ). For example, a user can transmit an account receivable value from a facility terminal 104 to the accounting server 106 . In an embodiment, the data is manually entered on an accounting terminal 102 and transmitted via an intranet connection 110 to an accounting server 106 . In one embodiment, the account receivable value represents the amount due from an organization, an individual or a government. An organization may include non-profit organization and/or for-profits organizations.
Subsequently, the example process 400 receives an actual payment associated with the first account receivable value (block 404 ). For example, a user could receive a payment and then enter a value of the payment on a facility terminal 104 . This value may then be transmitted to the accounting server 106 . In one embodiment, the payment information is in the form of a check, cash or a money order. In an embodiment, the payment information is in the form of an electronic receipt that is transmitted directly to the accounting server 106 from another facility, such as a bank. In an embodiment, an accountant manually enters payment information on the accounting terminal 102 and transmits the data to the accounting server 106 .
The example process 400 then compares the actual payment and the first account receivable value to determine an actual realization amount (block 406 ). For example, the actual payment could be subtracted from the first account receivable value and the result could be divided by the original account receivable value, providing a percentage of remaining account receivable. In an embodiment, a plurality of actual realization amounts are calculated based on the type of account receivable values present in the system, such as the realization amount relating to recovery of bad debt cases.
The example process 400 then receives a second account receivable value (block 408 ). For example, an accountant may enter an account receivable value into an accounting terminal 102 for transmission to the accounting server 106 . In an embodiment, the accounting terminal 102 automatically generates an account receivable value, based on stored data, and transmits the account receivable value to the accounting server 106 . In another embodiment, the account receivable value is generated based on accounting rules, such as a Medicaid accounting rule.
The example process 400 then calculates a net receivable value associated with the second account receivable value using the second account receivable value and the actual realization amount (block 410 ). For example, the actual realization amount may be multiplied with the second account receivable value. In an embodiment, the actual realization amount is multiplied with the second account receivable value as well as modified by another value, such as an interest amount. In one embodiment, a plurality of net receivable values are calculated based on the type of account, such as individuals, corporations, organizations, etc. Other types of accounts include bad debt accounts, frequently late payment accounts, credit accounts, etc.
The example process 400 then generates a display indicative of the net receivable value (block 412 ). For example, a chart may be provided showing the net receivable value and/or other statistics. In an embodiment, a graph is presented showing the net receivable value or other statistics. In an embodiment, a plurality of net receivable values are presented, such as the net receivable values for a number of franchises or facilities. In an embodiment, a plurality of net receivable values are presented, indicating net receivable values based on the type of account.
Preferably, one or more of the steps in process 400 are presented to users via a menu system. A screenshot of an example menu 500 is presented in FIG. 5 . Although the menu 500 is described with reference FIG. 5 , it will be appreciated that many other configurations are possible. For example, elements could be in different locations, elements could have different names, and elements could have different graphical representations.
The example menu 500 contains a high level statistic category 502 . The high level statistic category, for example, can pertain to different categories of statistical analysis available to the user. The user can select a category, for example, using a mouse by clicking on the category, or using a touch screen by touching the appropriate category. The detailed statistical category 504 is contained, for example as a subset of the high level statistical category. In the current example, the detailed category appears as a sub category of a high level statistical category.
A screenshot of an example category metrics view 600 is presented in FIG. 6 . Although the category metrics 600 is described with reference FIG. 6 , it will be appreciated that many other configurations are possible. For example, elements could be in different locations, elements could have different names, and elements could have different graphical representations. The category metrics 600 , can contain a view by facility 602 . For example, if there are multiple facilities, the user can select which facility to view with a drop down box 602 . Additionally, the category metrics view 600 can contain header information for specific statistic data 604 . The category metrics view 600 can also contain the actual expected value or actual received value 606 . The actual expected or received value can be shown, for example as a dollar amount or graphically represented.
A screenshot of an example account receivable entry 700 is presented in FIG. 7 . Although the accounts receivable entry 700 is described in reference FIG. 7 , it will be appreciated that many other configurations are possible. For example, elements could be in different locations, elements could have different names, and elements could have different graphical representations. In one embodiment, the account name 702 is displayed with an associated due date 704 , first account receivable value 706 , account type 708 , and status of account 710 . In one embodiment, the account type 708 is used in process steps 406 and 410 to calculate account type specific data. In one embodiment, the account type 708 is used in process step 412 to display the net receivable value by account type, such as displaying by individual customer accounts or by government accounts.
A diagram of the relation between the first account receivable value 706 , unrealized value 606 , actual payment value 802 and actual realization amount 804 is presented in FIG. 8 . In one embodiment, first account receivable value 706 has an associated actual payment value 802 . In an embodiment, the unrealized value 606 is the difference between the first account receivable value 706 and the actual payment value 802 . For example, if the first account receivable value 706 is $15,000 due in January and the actual payment value 802 is $10,000 in January, then the unrealized value 606 is $5,000 on the January invoice. In one embodiment, the actual realization amount 804 is the actual payment value 802 divided by the first account receivable value 706 . For example, using the above values, $10,000/$15,000 or 67%.
A diagram of the relation between a second account receivable value 902 , an actual realization amount 804 and net receivable value 904 is presented in FIG. 9 . In one embodiment, the actual realization amount 804 is multiplied with the second account receivable value 902 to determine the net receivable value 904 . For example, if the second account receivable value is $10,000 due in February and the actual realization amount 804 is 67% then the net receivable value 904 is $10,000*67% or $6,667.
A diagram of the relation between the first account receivable value 706 , the second account receivable value 902 , the account receivable different value 1002 , and the high level fluctuation threshold 1004 is presented in FIG. 10 . In one embodiment, the high level fluctuation threshold 1004 is defined by the user. For example, the high level fluctuation threshold 1004 is set by the user to $3,000. In the embodiment, the account receivable difference value 1002 is determined by taking the difference between the first account receivable value 706 and the second account receivable value 902 . For example, if the first account receivable value 706 is $15,000 and the second account receivable value 902 is $10,000, then the account receivable difference value 1002 is $15,000−$10,000 or $5,000. With the above example, high level fluctuation threshold 1004 , the account receivable difference value 1002 would be greater than the account receivable difference value 1002 and an indication would be displayed to the user.
A screenshot of an example account receivable entry 1100 is presented in FIG. 11 . Although the accounts receivable entry 1100 is described in reference FIG. 11 , it will be appreciated that many other configurations are possible. For example, elements could be in different locations, elements could have different names, and elements could have different graphical representations. In one embodiment, the account name 702 is displayed with an associated first account receivable value 706 , discount 1102 , actual payment value 802 , and unapplied discount account indicator 1104 . In one embodiment, the system determines whether the discount 1102 has been applied to the account based on the first account receivable value 706 and the actual payment value 802 . For example, if the discount value 1102 is 10%, the first account receivable value 706 is $1,000 and the actual payment value 802 is $1,000 then the unapplied discount account indicator 1104 would be true. However, in another example if the first account receivable value 706 is $5,000, discount 1102 is 10% and the actual payment value 802 is $400, then the unapplied discount account indicator 1104 would be false.
A diagram of the relationship between the reserve value 1202 , second account receivable value 902 , net receivable value 904 , expected unrealized value 1204 , and expected reserve value 1206 is displayed in FIG. 12 . In one embodiment, the expected unrealized value 1204 is the difference between the second account receivable value 902 and the net receivable value 904 . For example, if the second account receivable value 902 is $8,500 and the net receivable value 904 is $7,500 then the expected unrealized value 1204 is $8,500−$7,500 or $1,000. In one embodiment, the expected reserve value 1206 is the sum of the reserve value 1202 and the expected unrealized value 1204 . For example, if the reserve value 1202 is $10,000 and the expected unrealized value 1204 is $1,000 then the expected reserve value 1206 is $10,000+$1,000 or $11,000. In one embodiment, the expected reserve value is displayed and can be used to forecast reserve shortfalls or surpluses. In the embodiment, the reserve value is associated with an amount necessary to compensate for at least one of bad debt write offs, charity care and expected discounts. In one embodiment, the reserve value can come from a plurality of sources. For example, the reserve value 1202 can be received from banks, outside accounting sources, and manual input, et al. In one embodiment, the reserve value 1202 can include a plurality of values. For example, the reserve value can include stocks, bonds, cash, and certificates of deposit, et al.
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. | The present disclosure provides methods and apparatus for analyzing the revenue cycles of a facility to more accurately predict future financial performance. Using the methods and apparatus disclosed herein, accountants and financial planners are given forecasts of future accounts paid based on current accounts receivable and past accounts paid. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates to a prepared product and method for agglomerating and removing oil that has been spilled in the marine environment, including crude oil, bunker oil and other heavy oil products.
BACKGROUND OF THE INVENTION
[0002] The catastrophic effects on the environment of marine oil spills are well known. A principal problem is the eventual loss of buoyancy or increase in specific gravity of the spilled oil that leads to the sinking of clumps of oil for which there is no practical means of recovery from the submarine environment.
[0003] Various physical and chemical means have been proposed and are in use for ameliorating and recovering oil spills. Most of the means known to the prior art have limited capabilities to effectuate the complete recovery or clean-up of oil-spills, particularly those occurring at sea. Whether effective or not, means employed to date have been expensive.
[0004] It is therefore an object of the present invention to provide a novel product and method that is relatively inexpensive to produce and relatively easy to deploy at the site of the spill.
[0005] Another object of the invention is to provide a product that can be produced using polymeric packing materials and other waste that would customarily be consigned to land fills or other disposal sites.
[0006] Yet another object of the invention is to provide a product and method for its use that will maintain the spilled oil on the surface of the body of water and prevent the oil from sinking into the submarine environment before it can be recovered.
SUMMARY OF THE INVENTION
[0007] The above objects and additional advantages are achieved by the present invention in which oil-absorbent particles are prepared by grinding, abrading, shredding, pulverizing or otherwise comminuting preformed and molded blocks or other relatively larger regular or irregular pieces of rigid foamed or expanded cellular polystyrene into particles possessing a cellular structure and having irregular shapes and large oil-contacting surface area. In one preferred embodiment of the invention, the particle size distribution is in the range of from 4 mesh to 16 mesh, based on a corresponding aperture size from 4.75 mm to 1.18 mm.
[0008] The particles are spread on the surface of the oil spill and the water surrounding the margins of the spill. As compared to the density of water at one gram/cc and oil (average density of about 0.8 gm/cc), the foamed polystyrene with a density of 0.02 gm/cc is capable of maintaining its position on the surface even after absorbing water and/or oil. The foamed or expanded cellular polystyrene particles that are placed on the surface of the oil or that otherwise float into contact with the spilled oil, agglomerate and maintain the oil on the surface of the water, thereby facilitating removal of the spilled oil from the water's surface and also preventing it from eventually sinking below the surface where it can cause further damage to the marine environment.
[0009] The particles can be most economically produced by using disposable molded polystyrene foamed packaging materials, insulating panels and other waste materials having a rectilinear or other regular configuration. Irregular shapes and sizes of expanded foamed polystyrene materials can also be used. Waste or scrap material from facilities producing molded foamed polystyrene products can also be used for further processing. The material is commonly referred to by its trademark STYROFOAM which is registered in the United States and elsewhere. The invention has the further desirable environmental effect of reducing the quantity of such materials that are currently disposed of in land fills and waste disposal sites, or by less desirable means.
[0010] Particles of the appropriate size have been produced by contacting preformed molded packaging materials of a variety of shapes with an abrasive surface in the form of a conventional abrasive, such as emery/corundum cloth and sandpaper. Any of a wide variety of other abrasive surfaces and devices known to the art can also be used to comminute the cellular polystyrene foam starting material. Shredding machines, pulverizing devices and other material handling and treating equipment known to the art can be used, or adapted for use, in preparing the particles in the size ranges desired for use in the invention. Expanded polystyrene foam particles that have been produced directly from expandable beads and not molded into shapes can also be used directly. Particles having an irregular surface and concomitant large surface area are preferred for use in the invention.
[0011] As will be apparent to those of ordinary skill in the art, specialized apparatus can be constructed for comminuting large volumes of scrap foam waste products for use in the invention. For example, foamed polystyrene material recovered from recycling centers can be supplied to an automated processing facility that includes a feed hopper, a conveyor for the foamed material, a primary shredder to reduce the size of larger pieces to a predetermined maximum, and one or more comminuting rollers that draw the foamed material through opposing surfaces to produce particles in the desired size range. Industrial shredding, chipping and milling machines can also be used or adapted for use in producing the particles having the desired size and irregular surfaces for the practice of the invention.
[0012] Scraps and pieces of waste foamed polystyrene have been comminuted in a blender to produce a satisfactory mix of particles for sieving and testing. Care must be taken to avoid excessive heating during this operation, since the foamed particles are subject to melting.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] In the following series of tests, blocks of molded foamed polystyrene packing material were abraded using a medium grade of emery cloth. The resulting particles were collected and sieved using laboratory sieve screens acquired from W.S. Tyler, Inc. The operative sizes corresponding to the mesh numbers for the laboratory sieve screens used are set forth in Table 1.
TABLE 1 Mesh # 4 8 12 14 16 Aperture (mm) 4.75 2.36 1.70 1.40 1.18
[0014] The irregular expanded foam polystyrene particles collected during the abrading process were introduced in a sieve tower that included 4, 8, 12, 14 and 16 mesh sieves or screens. The tower was agitated and the particles were collected from below each sieve for testing.
[0015] A series of tests were conducted on samples of Arab light crude oil using predetermined quantities of the ground foamed polystyrene particles collected during the sieving step described above. Particles of 4, 8, 12 and 16 mesh size were tested. The data of Table 2 reports the absorption efficiency of each of the particle sizes when the same total weight of each particle size was manually spread over the surface of oil floating on water in laboratory glassware. Test were conducted using fresh water and seawater with comparable results.
[0016] In these tests, three (3) grams of particles of the indicated mesh size were spread on 30 ml. of light crude oil on water in a 250 ml. glass beaker and lightly stirred using a glass rod. The test sample was removed from the water's surface using a hand-held sieve. The efficiency results reported in Table 2 are the average of three sample tests for each of the mesh sizes.
[0017] The absorption efficiency recorded in Table 2 was calculated as follow:
Efficiency = [ ( Foam Final Weight - Foam Initial Weight ) - Weight of Absorbed Water Crude Oil Weight ] × 100
[0018] The weight of water absorbed by a 3 g foam sample was determined to average 2.15 g.
TABLE 2 Foam Foam Crude Crude Initial Final Absorption Exp Mesh volume weight Weight Weight Efficiency Avg. # Size (ml) (g) (g) (g) (%) (%) 1 16 30.00 25.60 3.00 29.00 93.16 95 2 30.00 25.60 3.00 29.70 95.90 3 30.00 25.70 3.00 29.50 94.75 1 12 30.00 25.50 3.00 29.70 96.27 99 2 30.00 25.50 3.00 30.70 100.20* 3 30.00 25.50 3.00 30.70 100.20* 1 8 30.00 25.80 3.00 27.70 87.40 95 2 30.00 25.90 3.00 29.70 94.79 3 30.00 25.90 3.00 31.70 102.51* 1 4 30.00 25.60 3.00 50.00 81.45 78 2 30.00 25.60 3.00 50.00 81.45 3 30.00 25.60 3.00 47.00 69.73
[0019] Efficiency values in Table 2 that exceed 100% are marked with an asterisk (*) and are due to the presence of water droplets that were entrained in oil-containing foam particle clusters. When the particles form into clusters, small cavities are created in which water droplets can be entrained. Droplets are also transferred during the sieving step. To the extent that the droplets were observed, they were dried out or decanted from the weighing dish before the measurement was taken. In any event, the trend in the data collected establishes the utility of the product and its method of use in stabilizing oil spills for removal.
[0020] The results of these tests indicate that the smaller particles are capable of absorbing a relatively greater quantity of light crude oil for a given weight of the foamed cellular polystyrene particles.
[0021] In another series of tests, the rate of water absorption of test particles of foamed polystyrene was determined. Particles passing the 8 mesh screen were collected and equal quantities weighting 1.06 grams were placed in water for time periods of ten minutes and twenty minutes, respectively, removed and weighed to determine the weight of water absorbed.
[0022] Other groups of particles were placed for periods of 10 and 20 minutes, respectively, on the surface of 10 ml of light crude oil that was floating on water contained in a 250 ml glass beaker. The particles were then removed for weighing. The results, as reported in Table 3, indicate that one gram of 8 mesh foam absorbs on average about 1.57 gm of water in each of the two time intervals, and with no significant observable effect on the efficiency of oil adsorption.
TABLE 3 Sample # (Time) Water Absorbed (gm) Oil Absorbed (gm) 1 (10 min.) 1.44 6.23 2 (10 min.) 1.54 6.24 3 (10 min.) 1.64 6.05 4 (20 min.) 1.72 6.02 5 (20 min.) 1.72 6.08 6 (20 min.) 1.34 6.40
[0023] This aspect of the product is important in the practice of the invention where the foam particles can be expected to come into contact with water surrounding the spill or in channels or openings formed between portions of the spilled oil caused by wind, waves and/or the irregular leakage of oil from the source of the spill. Thus, even though the foamed particles of the invention come into contact with water, they retain their capacity to absorb and agglomerate the oil with almost the same efficiency as particles contacting only the oil.
[0024] Without being limited to a particular theory, this advantageous effect may be related to the surface tension, measured in dynes/cm 2 , of the components of the system. With a value of 73 the surface tension of water is much greater than that of oil at 35 and foamed polystyrene at 33. The relatively small difference in the surface tension of the oil and polystyrene apparently facilitates their ready “mixing” and agglomeration.
[0025] It has also been found that the foamed particles maintain their integrity and are not degraded by relatively long contact with the agglomerated oil. In one extended test, the particles spread on the oil maintained the oil on the surface of water for about six months. As would be expected, no apparent degradation in foamed polystyrene particles left in water without oil has been observed in similar long-term tests.
[0000] Preparation of Foam Particles
[0026] Rigid polystyrene foam, or expanded cellular polystyrene, can be produced from expandable cellular polystyrene beads or purchased in the form of blocks, panels, sheets and other custom shapes. In a preferred embodiment of the present invention, foamed packaging materials such as those used for packaging and cushioning a wide variety of products, including electronic devices and other delicate equipment are collected as a waste product. These waste materials are contacted with a grinding or abrading surface, such as emery cloth, sandpaper and the like.
[0027] The ground particles of foamed polystyrene can be dispersed on, and around the surface of the marine oil spill by any convenient means that is available. Because of its low density, the particulate foamed polystyrene of the invention can be packaged for manual handling in relatively large and light-weight containers, such as disposable plastic bags. The plastic bags can be carried to the scene of the spill by aircraft, e.g., helicopters, and small boats, where the bags are cut open for dispersal of the particles.
[0028] The particles can also be dispersed by compressed air and/or pressurized air jets using large diameter hoses, tubes and nozzles. Under appropriate weather conditions, dispersal points can be selected upwind of the spill and the effect of prevailing winds utilized to assist in distributing the light-weight particles over the surface of the spill. Small watercraft can navigate the clear periphery of the spill where the crew can manually disperse the particles onto the water adjacent the spill to define a boundary for later collection of agglomerated particles. The dispersal of the particles can also be used with floating booms of the type used to contain marine spills that will also serve to contain the floating particles of the invention for eventual pick-up.
[0029] Specialized equipment currently available for distributing lightweight materials of other types can also be adapted for use in this aspect of the method of the invention. In one embodiment, the foamed polystyrene particles are sprayed as a slurry with water and/or other chemicals to permit their wider dispersal from the periphery towards the center of an expansive spill.
[0030] Aircraft equipped with bins or hoppers for containing the particles and having associated screw feeds or other means for the controlled volumetric discharge of the particles from dispensing tubes or nozzles projecting from the aircraft can be used advantageously to disperse the particles in areas that might not otherwise be accessed and/or reached quickly by water craft or land-based personnel and equipment. The particles can also be air-dispersed from large, light-weight containers of the type used to drop water in fighting forest fires. The particles can be wetted with water and/or other chemicals to increase their density to a predetermined, controlled value to facilitate their controlled dispersal.
[0031] A chemical emulsifier can also be sprayed or otherwise applied to the surface of the oil spill in conjunction with the dispersal of the expanded foam polystyrene to enhance the agglomeration of the materials.
[0032] Chemical wetting agents can also be applied to the particles prior to, or at the time of their dispersal to facilitate agglomeration after they have contacted the surface of the oil. The wetting agent is selected to further reduce the surface tension of the particle-oil interface.
[0033] While several illustrative embodiments have been provided for the preparation of the particles and their methods of use, other means will be apparent from this disclosure to those of ordinary skill in the art. | Irregularly shaped particles of foamed cellular polystyrene having a relatively large surface area produced by comminuting preformed solid blocks or other shapes of molded expanded polystyrene foam articles are spread on floating marine oil spills to agglomerate the oil and maintain it on the surface pending removal, thereby avoiding contamination of the submarine environment. The particles can be distributed in a dry state or mixed with a liquid to facilitate controlled spreading of the lightweight particles. | 2 |
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