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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 09/688,901 filed Oct. 16, 2000 and now pending.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to digital recording apparatuses used in conjunction with television and video cameras for observation, monitoring and security applications.
2. Description of the Prior Art
Signals of television cameras used in an observation system are fed to the monitoring site via closed wired circuits, or via public communication lines such as analog telephone lines or digital telephone lines, or via computer network or via RF links are commonly recorded onto a video cassette, such as the well known VHS, using VHS recorder. The VHS recorder is an analog recorder for recording analog television signals. Such analog recording onto VHS cassettes have been accepted by the courts at large as evidence, primarily on the grounds that the altering of the signals content is extremely difficult and moreover, such tampering with the recorded signals by trying to alter its content can be detected by experts. Moreover, the wide use of such analog recording onto VHS cassettes made the analog recording low in cost and popular. With the recent advances in digital recording of television signals it became simple to record the signal of television cameras used in observation system onto a hard disk of a PC or onto a hard disk of a specially constructed digital recorders. However, the hard disk of the PC or of the digital recorder has a finite capacity, which limits the length of time for archiving and/or storing the accumulated recorded signals. This can be solved by adding multiple hard disks or by using retractable hard disks. However, such retractable hard disk is very costly and requires expertise in handling. Another method to archive and store the recorded digital signals is by transferring the recorded digital signals onto digital tapes, cassettes, diskettes or disks such as the well-known CD or DVD.
This however causes a serious legal problem, hindering the use of the recorded material in courts; first because the recording is no longer the original recorded media, and secondly, it is literally impossible to identify the original from a copied or transferred data, and thirdly it is simple to alter a digitally recorded picture by changing its color, changing its time and date, removing objects from the picture content or adding objects into the picture. The ability to present a modified picture and to present a copied recording as an original recording, prevents the use of the digitally recorded pictures on tape, disk or diskette as evidence in courts. Furthermore, the tapes, disks and diskettes offer a limited recording time for no more than several hours which requires constant attendance for unloading and loading the tapes, disks and the diskettes, alternatively there are variety of automatic machines known as “juke boxes” for loading, unloading the recorded media that also provide for management of the recorded data. Such juke boxes however have also a finite data storage capacity and are very costly.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and apparatus for automatically feeding disks into a digital recorder and for automatically authenticating the recorded disks by imprinting coded information onto the disks and recording a coded data commensurating with the imprinted code into the picture signals, thereby providing the means for authentication of the disk as an original recorded media.
Another object of the invention is to provide a low cost disk changer that can record continuously a number of disks for an extended period of time by means of a simple loading of fresh unrecorded disks and simple unloading of the imprinted/recorded disks.
The above objects are achieved by an apparatus for digital recording, which comprises an imprinting head assembly, an upper compartment for holding fresh unrecorded disks, a pull slider assembly for pulling a first fresh unrecorded disk at the bottom of the upper compartment and for placing the pulled fresh unrecorded disk under said imprinting head assembly, said imprinting head assembly imprinting coded information onto the freshly placed disk, a disk recorder having a sliding table for supporting said disk, and a lower compartment for accommodating accumulated imprinted/recorded disks. The pull slider and the sliding table operate in concert such that when the pull slider and the sliding table are fully extended the freshly pulled disk and the imprinted/recorded disk are aligned against each other under the imprinting head. The imprinting head is mounted under a sliding piston to slide down and engage the freshly pulled disk for imprinting the coded information onto the disk surface and for pushing downward the freshly imprinted disk away from the pull slider and into the sliding table, which in turn ejects the imprinted/recorded disk from the sliding table into the lower compartment. Supported by the sliding table, the freshly imprinted disk is retracted into the disk recorder for recording. Simultaneously, the sliding piston starts its upward movement raising the imprinting head while the pull slider retracts into the pull slider assembly readying itself for the next disk pull cycle. As the disk recorder completes its recording it will generate a command signal to start a new cycle of pulling, imprinting and loading a fresh disk into the sliding table to finally eject the newly recorded disk in an endless rotation for as long as fresh disks are loaded into the upper compartment and the imprinted/recorded disks are removed from the lower compartment.
The objects of the invention are also attained by a method for authenticating the recording of digital video signals onto a fresh unrecorded disk by a disk recorder of a disk feeder system including coding generating and mixing means, and a code imprinter, the method comprising the steps of: feeding said fresh disk from a fresh disk compartment of said disk feeder system to said disk recorder through said code imprinter; generating an exclusive code for each said fresh disk fed to said disk recorder and imprinting said exclusive code onto a surface of said fresh disk such that an imprinted disk is fed to said disk recorder; and generating coded signals commensurating with said exclusive code and mixing said coded signals with said digital video signals recorded by said disk recorder, thereby authenticating said recording of the recorded disk outputted from said disk feeder system.
The objects of the present invention are further attained by a method for authenticating the recording of digital video signals onto a coded disk by a disk recorder of a disk feeder system including a code reader and a code generating and mixing means wherein said coded disk includes an exclusive code imprinted onto its surface, the method comprising the steps of: feeding said coded disk from a fresh disk compartment of said disk feeder system to said disk recorder through said code reader; reading said exclusive code of said coded disk fed to said disk recorder; and generating coded signals commensurating with said exclusive code and mixing said coded signals with said digital video signals recorded by said disk recorder, thereby authenticating said recording of the recorded disk outputted from said disk feeder system.
The method of the present invention may be adapted for authenticating the reading back of the digital video signals recorded, from the recorded disk, wherein the disk recorder further includes readback means and said disk feeder system further includes a code reader and a code signal extractor and a comparator, and method further comprising the steps of: loaded said recorded disk into said fresh disk compartment for feeding said recorded disk to said disk recorder through said code reader for reading said exclusive code from the surface of said recorded disk and reading back said video digital signals through said readback means; and extracting said coded signals through said code extractor and comparing said reading of said exclusive code with said extracted coded signals and outputting authentication signals when said exclusive code and said coded signals commensurate.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and features of the invention will become apparent from the following description, given as a non restrictive example and made with reference to the accompanied drawings, in which:
FIG. 1 is a perspective view of an exemplary embodiment of a digital recording apparatus according to the invention;
FIG. 2 is a perspective view of a well-known disk recorder with a modified sliding table to enable the ejection of a disk downward;
FIG. 3A is a perspective view of a pull slider assembly for pulling a fresh disk from a fresh disk stack of the apparatus of the present invention;
FIG. 3B is a top view of a pull slider of the pulling slider assembly of FIG. 3A ;
FIGS. 4A-4E are cross-sectional views showing the process of pulling and loading a fresh disk into the pull slider of FIGS. 3A and 3B ;
FIG. 5 is a sectional view of a combined pull slider and the sliding table of FIG. 2 and FIG. 3 ;
FIGS. 6A-6D are side and front views, respectively, of an imprinting head assembly in its engage-rest states;
FIG. 7 is a perspective view of the imprinting head incorporating an imprint readout device;
FIG. 8 shows a recording disk with an imprint coat; and
FIG. 9 is a block diagram of the system control of the apparatus of the present invention.
FIG. 10 is a perspective view of another exemplary embodiment of a digital recording apparatus according to the invention;
FIG. 11 is a perspective view of an expanded exemplary embodiment of a digital recording apparatus of FIG. 10 with two disk recorders;
FIG. 12 is a perspective view of a digital recording apparatus of FIG. 11 with the disk recorders, a fresh tray stack and a recorded tray stack in an elevated position;
FIG. 13 is a perspective view of an embodiment of a tray for supporting a disk;
FIGS. 14A-14D are perspective views, also showing enlarged view of some parts of a pull slider assembly for pulling a fresh tray from a fresh tray stack of the apparatus of the present invention;
FIG. 15 is a perspective view of an elevating platform for up-down moving of the tray stacks and the disk recorders;
FIGS. 16A-16D are perspective views showing the process of retracting a pull lever and transporting the trays to and from the disk recorder; and
FIGS. 17A-17D are perspective views showing the retracting and transporting process of the trays with two pull levers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an exemplary embodiment of a digital recording apparatus 1 which includes a compartment 3 for holding a fresh stack of disks 5 on top of a pull slider assembly 10 . The pull slider assembly includes a pull slider 12 that is shown extended all the way out from the pull slider assembly 10 , containing and supporting a pulled fresh disk 5 B into a position directly under an imprinting head 9 . A disk recorder 15 which is mounted under the pull slider assembly 10 , includes a sliding table 17 shown in its extended state and supporting an imprinted/recorded disk 5 H in a position directly under the fresh disk 5 B. An imprinting assembly 7 which has the imprinting head 9 is attached to a sliding piston 8 which slides down to engage the imprinting head 9 with the upper surface of the fresh disk 5 B for imprinting a coded information 5 C onto the disk 5 B and for pushing the disk 5 B downward out from the pull slider 12 all the way toward the imprinted/recorded disk 5 H in order to insert the newly imprinted disk 5 B into the sliding table 17 and eject the imprinted/recorded disk 5 H from the sliding table 17 into a lower compartment 30 . The ejected disk 5 H shown in FIG. 1 falls as a free falling disk 5 J onto an accumulated imprinted/recorded disk stack 5 M. A compartment cover 32 is shown opened but it is normally closed during the operation. The compartment cover 32 has a window 32 A for instant viewing of the lower compartment content.
As the ejected disk 5 J falls into the lower compartment 30 the sliding piston 8 shown in lowered position along with the imprinting head starts its upwards movement cycle away from the pull slider 12 so as to bring the imprinting head 9 into its rest position. Immediately after the imprinting head 9 is pulled up the pull slider 12 that is now emptied from the disk 5 B starts its retracting cycle back into the pull slider assembly 10 . Simultaneously the sliding table 17 that is now loaded with a fresh disk 5 B with an imprint SC starts its retracting cycle back into the disk recorder 15 . The disk recorder 15 shown in FIG. 2 with its sliding table 10 is modified to provide for ejecting the disk downwards, is a well-known disk recorder used in personal computers, such as CD or DVD recorders. The disk recorder 15 will start its recording of picture signals fed to it through the electronic circuits contained in the system control 40 shown in detail in FIG. 9 and described in detail below. The system control 40 also generates the imprinted coded information SC, and mixes commensurating coded signals into the recording of the pictures signals which ties together the physical imprint of the disk to the contained recorded signals, for authenticating the imprinted disk as an original media. Referring to FIG. 2 the disk recorder 15 comprises a case 15 H, a body 15 A, a recording control circuit 15 B, a recording and playback head 1 SE, a disk drive 15 C, a head drive 15 F and the sliding table 17 . The sliding table 17 includes a geared bar 17 D driven by a driving gear 15 D reciprocally, and a motor controlling the gear 15 D. Such a motor is a well known motor with a gear assembly and is therefore not shown. The sliding table further includes an opening 17 C for providing the supported disk 5 H of FIG. 1 to be ejected downwards, a tapered circumferential rim 17 A for supporting the disk 5 B or 5 H of FIG. 1 while moving the disk in and out from the disk recorder, and circumferentially extending tongs 12 B for gripping the disk 5 H prior to the final ejection. The disk drive 15 C of the well known disk recorder 15 raises the disk upwards away from the sliding table 17 during the recording or playback process, by the well known disk drive 15 C and lifting mechanism (not shown), and the recording/playback head 15 E travels throughout the width of the disk by the well known head drive mechanism 15 (not shown). Accordingly, the supported freshly imprinted disk 5 B of FIG. 1 is driven into the disk recorder 15 by the sliding table 17 ; it is then lifted by the disk drive 15 C for recording, and when the recording is complete the disk drive 15 C lowers the freshly recorded disk 5 D onto the sliding table which is then extended outwards by the drive gear 15 D and placed into the position under the fresh pulled disk 5 B. The pull slider assembly 10 is constructed essentially with a pull-sliding table 12 similar to the sliding table 17 of the disk recorder 15 .
Shown in FIGS. 3A and 3B , is the pull slider assembly 10 including a case 10 H, a body 10 A, a control circuit 10 B, an opening for fresh disks 10 C, a support 10 S for the first disk in the stack, a cushion 10 G and a pull slider 12 . The pull slider 12 includes a geared bar 12 D driven by the driving gear 10 D reciprocally, an opening 12 C for allowing a fresh disk to be pushed through downwards, a tapered circumferentially extending rim 12 A for centering the pulled disk and tongs 12 B extending downwards from rim 12 A for gripping the pushed disk during the imprinting process. The pull slider 12 further has a flexible pull lever 12 S shown in FIG. 3A for pulling the first or the bottom disk 5 A from the fresh disk 5 stack shown in FIG. 1 .
FIGS. 4A-FIG . 4 E show the process of pulling and feeding the disk 5 A into the sliding table, wherein FIG. 4A shows the pull slider 12 at its initial retraction and the flexible pull lever 12 s which is about to be compressed under the disk 5 A. FIG. 4B shows the pull slider 12 at its mid-way retraction with the pull lever 12 S/D slides under the disk 5 A. FIG. 4C shows the pull slider 12 fully retracted and the pull lever 12 S stretching fully behind the disk 5 A, ready to engage the disk rim. FIG. 4D shows the pull slider 12 in its early movement outwards pulling the disk 5 A to a point just before the disk 5 A leaves its support 10 S and cushion 10 G. FIG. 4F shows the disk 5 B being pulled by the movement of the pull slider 12 outwards and falling into the tapered rim 12 A while the newly first fresh disk 5 A falls onto the cushion 10 G.
When the recording of the disk is complete the control system 40 generates a start cycle command to the pull slider 12 to pull and feed a fresh disk 5 B to its imprinting position under the imprinting head and to the sliding table to remove the imprinted/recorded disk 5 D from the disk recorder and position the disk under the disk 5 B. Thereafter, as the disks are positioned under the imprinting head 9 the piston 8 starts its downward movement to engage the printing head 9 with the upper surface of the fresh disk 5 B and thereby also push the imprinted disk 5 B downwards into the sliding table 17 all the way so that the imprinted/recorded disk 5 H is ejected into the lower compartment 30 .
FIG. 5 shows the pull slider and the sliding table being combined into a single sliding table 22 in which the pulling of a disk from the fresh disk compartment and the feeding of the disk to the disk recorder is performed by a single sliding table, wherein the tapered rim 12 A, tongs 12 B and the pull lever 12 S of the pull slider 12 are replaced by a tapered rim 22 A, tongs 22 B and a pull lever 22 S of the combined slider 22 . The tapered tongs 17 B and the geared bar 17 D of the sliding table 17 are replaced by tapered circumferentially extending tongs 27 B and a geared bar 27 D of the combined slider 22 , which otherwise operates in the same manner as the two individual sliders 12 and 17 .
The shown pull lever 12 S of FIGS. 3A and 3B or the pull lever 22 S of FIG. 5 are simplified illustrations of a pull lever. In practice such lever may be supplied with means for preventing damage to the disk surface, by using rollers, balls or other rotating parts to prevent direct touch by the pull lever onto the surface of the disk. Similarly, the tapered rim 12 A or the tong 12 B of FIG. 3A and the tongs 17 B of FIG. 2 or the tapered rim 22 A and the tongs 22 B and 27 B of FIG. 5 are simplified illustrations of the support means for the processed disks. Many other shapes and forms can be used for placement, support and ejection of the processed disks. Similarly, the geared bars 12 D and/or 27 D of FIG. 3A and FIG. 5 , respectively, along with the drive gears 10 D and 15 D can be differently constructed to drive the sliding table 17 , the pull slider 12 or the combined slider 22 .
Shown in FIG. 6A , FIG. 6B and FIG. 6C is an imprinting head assembly 70 which consists of the imprinting head 9 , piston 8 , a motor assembly 70 M, a cam 70 C, a spring 70 S and a guide 70 G. FIG. 6A shows a side view of the assembly 70 with the piston 8 and the imprinting head 9 in their engaged state denoted at 50 A and their rest state denoted at 50 , FIG. 6B shows a front view of the assembly 70 in its engaged state identical to that of FIG. 6A , with its spring 70 S fully compressed, while FIG. 6C shows the same front view of the assembly but with its piston 8 in a raised position and the imprinting head 9 being in its rest position. The spring 70 S of FIG. 6C shown in its decompressed or expanded state. The guide 70 G shown attached to part of the body of the imprint assembly 7 (not shown in these figures) is a well-known bushing for guiding the piston up-down movement. FIG. 6D shows another well known reciprocal arm 71 A supporting the imprinting head 9 attached to a threaded bushing 71 B driven up-down by a threaded shaft 71 and powered by the motor 70 M. The illustrated movement of the imprinting head assembly is achieved by use of a well known up-down piston or a threaded shaft driven mechanism. However, there are many other well known mechanical devices to drive an imprinting head up-down and for applying pressure onto the imprinted disk while imprinting a coded information 5 C shown in FIG. 1 so as to place/eject the disks into and from their respective sliders. The imprinting head itself can be a well known laser imprinter, a well known heat stamping head, a well known LED illuminator/imprinter, a well known ink jet imprinter, a well known optical/chemical imprinting head, a well known ribboned imprinter, or a well known adjustable rubber pad. Many other well known imprinting methods and heads can be utilized and moreover, as will be explained later, the fresh disks 5 of FIG. 1 can be fed already imprinted to the fresh disk compartment 3 and/or the imprinter head can be replaced by a well known sticker applicator, sticking imprinted bar codes or other imprinted coded, non removable stickers onto the fresh disk surface.
Shown in FIG. 7 is the imprinting head assembly 9 including a transparent surface 9 A for providing a light passage for lasers 9 B or LEDs 9 C along with a reader/sensor 9 D for reading the imprinted code. The reader/sensor 9 D shown uses a wide angle lens with an CCD device. However, any other well known type of imprint reader/sensor such as CMOS, pin diodes or photo transistors can be used instead. The lasers 9 B and LEDs 9 C can be used for the imprinting process, while the LEDs 9 B can be used for illuminating the imprint to enable the reader/sensor 9 D to read the imprint such as the imprinted code 5 C shown in FIG. 1 .
The conventional disk recorder 15 shown in FIG. 2 further includes playback circuits for reading the signals from the recorded disk and for outputting the playback signals to a processing circuits of the system control 40 .
Shown in FIG. 9 is a block diagram of the system control 40 which includes a master control circuit 41 for setting, controlling and operating the system, a recording processor circuit 42 for processing video input signals fed through a video input 48 and code signals fed from a code generator 45 and for feeding the processed signals to the disk recorder 15 in accordance to control command of the master control circuit 41 . The code generator 45 also generates an exclusive, individual coded information to the imprinting head 9 for each disk being fed to the imprinting head 9 , wherein the coded signals fed to the recorded processor 45 commensurate with each such exclusive, individual coded information fed to the imprinting head 9 . A playback processor 43 of the system control 40 receives the read out signals from the disk recorder 15 and the read out code from the imprinting head 9 via the code reader circuit 44 and compares the code contained in the playback signals with the code read by the imprinting head, and feeds the comparison data to the master control circuit 41 and/or generates a yes or no signal to the master control circuit and/or into a display signals through a video out terminal 47 . A loading, unloading, sensing and control circuit 46 is fed with sensing signals from well known sensors such as LED interrupters, or micro switches (not shown) for sensing the state of the pull slider 12 , sliding table 17 , imprinting head 9 and/or gauging such item as the level of fresh disks 5 or the level of accumulated recorded disks 5 M shown in FIG. 1 . The loading, unloading, sensing and control circuit 46 feeds the received data to the master control circuit 41 and receives control commands from the master control circuit. It is clear that by the read-write arrangement of the system control 40 it is possible to load pre-imprinted fresh disks and to generate a code signal commensurating with the pre-imprinted code that is read by the reader/sensor 9 D of the imprinting head 9 and feed the generated code signal to the record processor circuit 42 for recording the video signals mixed with the generated code. The code signal generated by the code generator 45 may be an encrypted code, and use such data as time and date, station number, camera number, recorder number etc. It can be so designed that the imprinted coded information cannot reveal to the laymen any details of the actual recorded code, and that it will be impossible for a laymen to decipher the recorded code. By this it will only be possible to playback a recorded disk using the digital recording apparatus shown in FIG. 1 and only when the readout code and the extracted code from the playback signal commensurate. Only under such condition it will be possible to verify that the recorded disk is an original recorded media.
The disk 5 shown in FIG. 8 consists of a disk body 5 U, a recording layer 5 R, a top layer 5 T and an imprinted surface or a labeled surface 5 L. A pre-imprinted label can be attached to the disk surface to form labeled surface 5 L but only if such a pre-imprinted label is a well known label that cannot be removed from the disk without being torn, thereby, preventing the re-use of such label with another disk. The layer or the label 5 L shown covers most of a disk surface 5 T. However, a smaller label 5 L can be used instead, or it is possible to attach such labels by a well known (not shown) label applicator incorporated with the imprint head assembly.
The imprinted surface or the imprinted layer and/or the label 5 L can be made of a soft materials or combined with soft materials or such layers can be provided with a soft rim for providing scratch protection to the disks when they are stacked up one on top of the other. Furthermore, the layer 5 T can be a layer specifically matching the imprinting process such as optical/chemical process.
For the purpose of submission of evidence in courts it is preferable to use a well-known disk 5 that cannot be erased, nor re-recorded. Such imprinted disk that can only be recorded once and is recorded with a mix of code signals as explained above, provides a proof that such a digitally recorded disk is an original recorded media. Moreover, even the use of re-writable disk that can be erased and/or re-recorded and which is recorded by using the recording processes described above greatly inhibits the ability of a laymen to manipulate any individual picture and/or part of a picture, particularly when the code signals mixed with the picture signals are dynamic, encrypted and vary for every individual picture being recorded. Moreover, the controller can be programmed to read first the coded signals and the exclusive code and generate record stop command to prevent re-recording of a recorded/imprinted disk or to prevent the recording of a twice imprinted disk.
The present invention also provides for a continuous feed of disks to a digital recorder apparatus for instances that do not require the disk to be used as evidence. Alternatively the present invention can be used for an automatic search of a disk for a playback purposes only and the like.
The disks changing mechanism of the digital recording apparatus 1 of FIG. 1 uses gravitation and the free fall of disks for the loading/unloading process. However, such disk changing method prevents the introduction of multiple disk recorders 15 , nor does it provide for individual trays or containers to support or protect the disks 5 .
A digital recording apparatus 130 of FIG. 10 , which shows a further embodiment of the present invention, offers a different disk changer mechanism wherein fresh disks 5 are supported by a tray 60 . The stack of the fresh disks consisting of multiple trays 60 W each containing a disk 5 shown in FIG. 10 is placed between the bottom tray 60 E and the top tray 60 inside a fresh disk compartment 59 shown with its front cover 54 in the open position. The trays in the fresh disk compartment 59 are supported by an elevating platform 80 which raises the entire stack in steps equal to a single tray thickness, readying the tray 60 for a pull cycle by a pulling assembly 100 . The pulling assembly 100 transports the tray 60 to a position 60 A which is the loading position of a disk onto a disk recorder assembly 55 . The disk recorder assembly 55 is identical to the well known disk recorder 15 of FIG. 2 except that it is operated without the outer cover 15 H and without the sliding table 17 which is no longer needed because the disk 5 W is loaded by the tray 60 A directly to the disk driver 15 C shown in FIG. 2 . The disk recorder 55 is supported by a holder 55 A having a length equal to the length of the tray 60 .
As the pulling assembly 100 completes its forward cycle to load the tray 60 into the disk recorder 15 or to its new position 60 A the elevating platform 80 is activated to elevate the stack of the fresh disk trays 60 W by a single step so as to bring the upper disk 60 W into position 60 . Once the tray carrying the fresh disk 5 is in position 60 the imprinter or the code reader 9 will operate in a manner described for the digital apparatus 1 of FIG. 1 , with the exception that it no longer applies pressure onto the disk 5 to eject it. Furthermore, when the code reader 9 reads the code from the disk surface it does not need to slide down or to contact he disk, because it can read the code from a distance. When the imprint or the readout is complete the tray 60 with the disk 5 becomes ready for transporting and when the disk recorder 55 completes the recording of the disk 5 W the disk driver 15 C of FIG. 2 releases the disk 5 W, thereby readying the changer mechanism for a new loading/unloading cycle to begin.
The pulling assembly 100 moves in a reciprocal movement on the guide rail and gear rack assembly 101 in a retraction direction 107 all the way to engage the tray 60 and in a transporting direction 108 to pull the tray 60 toward the disk recorder 55 and into position 60 A. As the tray 60 starts its movement into position 60 A its front side 64 shown in FIG. 13 pushes the tray 60 A with the recorded disk 5 W toward the position 60 B and when the tray 60 reaches into position 60 A the prior tray 60 A is pushed all the way out from the disk recorder 55 onto the elevating platform 80 B. The elevating platform 80 B is identical to the elevating platform 80 for lowering the recorded trays stack as shown in FIG. 12 by a step equal to one tray thickness. By this step the changer mechanism 130 is readying itself to start the next unloading cycle.
The pulling assembly 100 shown in FIG. 14A includes a body 102 accommodating a motor 104 with a gear 105 for engaging a gear rack 101 A such that the reciprocal rotation of the motor 104 drives the pulling assembly 100 in the retracting direction 107 and the transporting direction 108 . The pulling assembly 100 further includes a pulling lever 103 for engaging a tray cutout 65 L shown in FIG. 13 and for pulling the tray 60 during the transporting cycle.
Shown in FIGS. 16A-16D is the movement of the pulling assembly 100 during retraction and transporting actions. FIG. 16A shows clockwise rotation 107 A of the gear as it begins the retracting movement from the position 100 A which is its maximum forward state or loading position. As shown in FIGS. 16B and 14A the pulling assembly is in its middle-way retraction with its pull lever 103 depressed inwards by the tray side so as not to obstruct the retracting movement and, as shown in FIG. 14A , the pull lever 103 has a pivoted lever 103 A impelled outwards by a spring 103 B. FIG. 16C shows the pulling assembly 100 C starting its transporting cycle from its maximum retracting position at which time the pull lever 103 is impelled into the tray cutout 65 L to engage the tray 60 and pull it toward the loading position 60 A. FIG. 16D shows the process of the transporting cycle in which the tray 60 is in its middle-way position 60 D pushing the tray 60 A to a middle-way position 60 U.
Instead of using the motor 104 , the gear 105 and the guide rail with a gear rack 101 ( FIG. 14A ) for transporting and retracting the pulling assembly 100 it is possible to use many other types of transporting mechanisms such as a chain, belt, threaded shaft or timing belt. Shown in FIG. 14B is such mechanism 120 using a timing belt 121 , driven by a motor 124 and sprockets or timing gears 122 and 123 ( FIG. 14B ). A body 125 of the pulling assembly 120 is similar to the body 102 of pulling assembly 100 except that it is driven by the timing belt 121 shown in FIG. 14B instead of the motor 104 and gear 105 of FIG. 14A .
Instead of using a single pull lever 103 it is possible to use multiple pull levers such as the 103 and 113 as shown in FIG. 17A , which depicts the movement of a pulling assembly 110 A at the initial retracting cycle. FIG. 17B shows a pulling assembly 110 B at its middle-way retracting cycle with its pull lever 113 being depressed by the side of the tray 60 A. FIG. 17C shows a pulling assembly 110 C at the start of the transporting cycle and FIG. 17D shows a pulling assembly 110 D at its middleway transporting cycle. The pull lever 103 shown in FIGS. 17C and 17D is shown engaging the fresh tray 60 , while the pull slider 113 is engaging the recorded disk tray 60 A and transporting the tray 60 to a mid position 60 D and the tray 60 A to mid position 60 U.
The pull levers 103 shown can be made in different shapes, or they can be made to engage a cutout or cutouts such as the cutout 65 L of the tray 60 shown in FIG. 113 from the upper surface of the tray or it can be made to engage the cutouts 65 L of both sides of the tray simultaneously. The pull lever 103 shown in FIG. 14A consist of a hinged pull lever 103 A driven or propelled by a spring 103 B however instead of the pull lever 103 A it is possible to use a pull lever similar to the pull lever 12 S of FIG. 4B without the use of the spring 103 B. Moreover, the pull lever 103 A can be differently shaped or constructed as long as it does not hinder the retraction of the pulling assembly 103 and engages the tray 60 during the transporting cycle.
Instead of using a spring propelled or self propelled pull lever it is possible to use a motorized or electrically activated pull lever or a pull pin such as 103 M and 103 N as shown in FIGS. 14C and 14D . The pull lever 103 M comprises a motor 103 U with a worm and a mating worm gear with a cam assembly 103 P. A motor 103 U will rotate the worm gear/cam assembly such that the cam protrudes during the transporting and retracts inwards into the pulling assembly body 102 during the retracting cycle. The pull lever 103 N is a plunger pin 103 W of a magnetic activated plunger unit 103 Q that is retracting into the plunger body when electrical power is applied to the plunger coil during the retracting cycle, while during the transporting cycle the electrical power is cut, the plunger 103 W is propelled and engages the cutout 65 L of the tray 60 .
The tray 60 shown in FIG. 13 includes a recessed compartment 63 for supporting a disk, the side cutouts 65 L and 65 N for engaging the tray by the pull lever of FIG. 14B , a single or dual groves 62 ( FIG. 13 ) for supporting a single or dual guides 68 of the tray on top of it in the tray stack. The single or dual guides 68 are provided for aligning the tray 60 into position onto the tray under it in the tray stack. Instead of the cutout 65 L used for engaging the pull lever 103 it is possible to add a projected portion on the side of the tray for engaging the pull lever. A grove 61 on the side of the tray 60 guides the tray movement onto the side rail 58 of the disk changer 130 of FIG. 10 .
The elevating platform 80 shown in FIG. 15 comprises a platform body 71 attached to a motor 72 with dual ended shaft terminated with a clockwise worm 73 at one end and a counterclockwise worm 73 A at the other end. The platform 71 is further attached to two gear assemblies 74 and 74 A, each consisting of a mating worm gear 76 and 76 A and a shaft 74 S terminated with two gears 75 and 75 A. The dual gear assemblies 74 and 74 A are positioned against the dual gear racks 53 and 53 A respectively, such that when the motor is energized and operated reciprocally the elevating platform will elevate or descend along the gear racks 53 and 53 A that are mounted inside the fresh and the recorded tray compartments 59 and 85 of FIG. 10 , respectively.
Well known LEDs, micro-switches or magnetic hall sensors and the like (not shown) can be employed to ensure correct and precise movements. Alternatively the motor 72 can be a stepping motor so that its step movements are precisely controlled, or other well known microprocessor control systems can be utilized to correctly and precisely set the up-down steps of the elevating platform 80 and/or how many steps should be incorporated in each command. Many other well known mechanical arrangements can be employed to raise or lower the elevating platform 80 such as chains and sprockets, timing belt with timing gears similar to the one shown in FIG. 14B or threaded shafts similar to the one shown in FIG. 6D .
The digital recording apparatus 130 of FIG. 10 comprises a single disk recorder 55 having a finite recording capacity per time unit and it may be necessary to provide multiple disk recorders 55 to increase the recording capacity per time unit. For this the digital recording apparatus 131 of FIG. 11 comprises two disk recorders 55 mounted on top of an elevating platform 80 A, which is identical to the elevating platforms 80 and 80 B for elevating or descending the disk recorders 55 along the gear racks 53 and 53 A mounted in the disk recorder compartment 90 .
The upper disk recorder 55 - 1 is positioned precisely as the disk recorder 55 of FIG. 10 is positioned and when the loading and unloading trays to and from the disk recorder 55 - 1 takes place the digital recording apparatus 51 will operate in the exact same manner as the digital recorder apparatus 130 of FIG. 10 is operated. However, when the need to unload and load a tray into the lower disk recorder 55 - 2 the elevating platform 80 A is activated to raise the disk recorder 55 - 2 along with the disk recorder 55 - 1 by several steps to align the disk recorder 55 - 2 with the tray 60 and tray 60 Z shown in FIG. 12 .
Same procedure will be applied to three, four, or more disk recorders 55 that may be added to the digital recorder apparatus 51 . Alternatively, the three elevating platforms 80 , 80 A, 80 B and the pulling assembly 100 along with an elevating platform for the guide rail and gear rack assembly 101 (not shown) may be raised or lowered in concert, such that the loaded and unloaded trays are aligned for transporting the fresh trays 60 into the respective disk recorders 55 - 1 , or 55 - 2 or into additionally added disk recorders 55 and the recorded trays 60 B onto the recorded tray stack.
The disk-feeding apparatuses 130 and 131 of FIGS. 10 and 11 respectively, can be used for recording of digital signals onto well known digital disks such as CD or DVD for purposes other than video and/or with or without the use of the imprinter and/or the code reader 9 . For such application it is possible to use the described disk feeding apparatus with or without the imprinter and/or the code reader 9 .
It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purpose of the disclosure, which modifications do not constitute departures from the spirit and scope of the invention: | A digital signal recording apparatus and a method of operating the same, used in conjunction with TV and video cameras, for example for security applications, includes a disk feeder system having a disk recorder and an upper compartment for holding fresh unrecorded disks, a pull slider assembly which pulls a first fresh disk at the bottom of the compartment and places the same and a printing head assembly which imprints coded information onto the placed disk, a disk recorder having a sliding table for supporting the disk and a lower compartment which accommodates the recorded disks. Supported by the sliding table the recorded disk is retracted into the disk recorder which, after the completion of recording, generates a command signal to start a new cycle. An exclusive code is imprinted onto the surface of the disk and coded signals commensurate with the exclusive code are generated by a controller and mixed with the digital video signals recorded by the disk recorder to authenticate the recording of the disk outputted from the disk feeder system. The apparatus may be equipped with a pull lever which engages cutouts provided on a fresh disk tray to transport the tray containing fresh disks from a feeding position to a recording head. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an optical module formed by a package for receiving and emitting light and an optical connector, and more particularly, to the improvement of a coupling structure between the package and the optical connector and its manufacturing method.
[0003] 2. Description of the Related Art
[0004] Optical interconnection of the LSI packages with each other by optical fibers or optical waveguides is attractive in order to enhance thee operation speed in a computer system where large scale integrated circuit (LSI) packages such as a central processing unit (CPU) and memories are mounted on a board.
[0005] Connecting the LSI packages with each other by using optical interconnection modules is one of possible way to establish inter-LSI package optical interconnection. In this configuration, however, the redundant portions of the optical fibers would need to be processed. Because the most of optical interconnection module have pig-tailed optical fibers of normalized length and these fibers are not detachable from the module. To avoid the optical fiber occupation on the board, it is preferable that the optical fibers are removable from the optical module. By this, optical modules are connected each other by optical fibers of preferable lengths.
[0006] Optical modules without pig-tailed optical fibers have been suggested. That is, optical fibers are removable from LSI packages, In this case, if the optical fibers are moved in the horizontal direction to couple with the LSI packages, dead space due to the horizontal motion of the optical fibers may be created on a board, so that the mounting density of LSI packages on the board is decreased. Therefore, it is preferable that the optical fibers be moved in the vertical direction to couple with the LSI packages.
[0007] In a first prior art optical module (see: JP-A-4-308804), an array of optical fibers adhered to a microlens array is moved down to couple with an LSI package, so that the above-mentioned dead space on a board is decreased to increase the mounting density of LSI packages on the board. This will be explained later in details
[0008] In the above-described first prior art optical module, however, if the alignment of the optical fibers to the LSI package fluctuates, the coupling efficiency therebetween deteriorates.
[0009] In a second prior art optical module (see: JP-A-10-115732), an optical fiber with a mirror and a half mirror is moved down to couple with a package. This also will be explained later in detail.
[0010] In the above-described second prior art optical module, however, since the mirror and the half mirror are protruded from the bottom surface of the optical fiber, the coupling between the optical fiber and the package is carried out by a transparent adhesive layer, so that it is impossible to remove the optical fiber from the package. Thus, the optical fiber is not removable. If the optical fiber is forcibly removed from the package and is again fixed to the package or another package, the coupling loss fluctuates.
SUMMARY OF THE INVENTION
[0011] It is an object of the present invention to provide an optical module capable of improving the coupling efficiency and suppressing the fluctuation of the coupling loss.
[0012] Another object is to provide a method for manufacturing such an optical module.
[0013] According to the present invention, in an optical module, a package includes an array of first optical elements and at least one first positioning member. A microlens array plate including microlenses is fixed to the package, so that each of the microlenses corresponds to one of the first optical elements. An optical array connector mounts second optical elements thereon. The optical array connector has a light path bending portion for bending light paths of the second optical elements and at least one second positioning member. The optical array connector abuts against the package by aligning the second positioning member to the first positioning member so that each of the first optical elements corresponds to one of the second optical elements. A clamping member clamps the optical array connector to the package.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will be more clearly understood from the description set forth below, as compared with the prior art, with reference to the accompanying drawings, wherein:
[0015] [0015]FIG. 1 is an exploded, perspective view illustrating a first prior art optical module;
[0016] [0016]FIG. 2 is a view of an assembled state of the optical module of FIG. 1;
[0017] [0017]FIG. 3 is a diagram illustrating a second prior art optical module;
[0018] [0018]FIG. 4 is an exploded, perspective view illustrating a first embodiment of the optical module according to the present invention;
[0019] [0019]FIG. 5 is a cross-sectional view of the fiber array connector of FIG. 4;
[0020] [0020]FIGS. 6A, 6B, 6 C and 6 D are cross-sectional views for explaining an assembling operation of the optical nodule of FIG. 4;
[0021] [0021]FIG. 7 is an exploded, perspective view illustrating a first modification of the optical module of FIG. 4;
[0022] [0022]FIG. 8 is an exploded, perspective view illustrating a second modification of the optical nodule of FIG. 4;
[0023] [0023]FIG. 9 is an exploded, perspective view illustrating a second embodiment of the optical module according to the present invention; and
[0024] [0024]FIG. 10 is an exploded, perspective view illustrating a third embodiment of the optical module according to the present invention.,
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Before the description of the preferred embodiments, prior art optical modules will be explained with reference to FIGS. 1, 2 and 3 .
[0026] In FIG. 1, which illustrates a first prior art optical module (see: JP-A-4-308804), an LSI package 101 includes LSI chips (not shown) and optical elements 101 a such as surface-emitting laser diodes and surface-receiving PIN photodiodes electrically connected to the LSI chips. Also, an array of optical fibers 102 are provided to correspond to the optical elements 101 a . In this case, each of the optical fibers 102 is constructed by a core layer 102 a and a clad layer 102 b surrounding the core layer 102 a. The facets of the optical fibers 102 are oblique, i.e., at 45° to the optical axes thereof, and a plane portion 102 c is formed at the clad layer 102 b of each of the optical fibers 102 . Further, a microlens array 103 is provided.
[0027] After a surface of the microlens array 103 is adhered to the plane portions 102 c of the optical fibers 102 , the optical fibers 102 are moved down so that the other surface of the microlens array 103 is adhered to the LSI package 101 .
[0028] Thus, as illustrated in FIG. 2, light emitted from of the optical elements 101 a is transmitted through the microlens array 103 and is reflected by the facet of one of the optical fibers 102 to pass through the core layer 102 a thereof. On the other hand, light emitted from the core layer 102 a of one of the optical fibers 102 is reflected by the facet of one of the optical fibers 102 and is transmitted through the microlens array 103 to reach a respective one of the optical elements 101 a.
[0029] If the array of the optical fibers 102 adhered to the microlens array 103 are removable from the LSI package 101 , the alignment of the optical fibers 102 to the LSI package 101 must be accurate. For example, if the diameter of the optical element 110 a is less than 30 μm, the error of the alignment of the optical fibers 102 to the LSI package 101 must be less than 5 μm. Therefore, if the alignment of the optical fibers 102 to the LSI package 101 fluctuates as indicated by dotted lines in FIG. 2, the coupling efficiency thereof deteriorates.
[0030] In FIG. 3, which illustrates a second prior art optical module (see: JP-A-10-115732), a silicon substrate 202 is adhered to a package 201 , and a surface-emitting laser diode 203 and a surface-receiving PIN photodiode 204 are adhered to the silicon substrate 202 . Also, a ceramic plate 205 for fixing microlenses 206 and 207 is placed on the package 201 .
[0031] Also, an optical fiber 208 supported by a precision capillary 209 is buried in a groove of a fiber burying substrate 210 which has an oblique end face for mounting a mirror 211 and a groove for mounting a half mirror 212 .
[0032] The fiber burying substrate 210 having the optical fiber 208 , the mirror 211 and the half mirror 212 is moved down, so that the fiber burying substrate 210 is fixed by a transparent adhesive layer 213 to the ceramic plate 205 .
[0033] Thus, light emitted from the laser diode 203 is transmitted through the microlens 206 and is reflected by the mirror 211 to pass through the half mirror 212 . On the other hand, light from the optical fiber 208 is reflected by the half mirror 212 and is transmitted through the microlens 207 to reach the PIN photodiode 204 .
[0034] In the optical module of FIG. 3, however, since the mirror 211 and the half mirror 212 are protruded from the bottom surface of the optical fiber 208 buried in the fiber burying substrate 210 , use is made of the transparent adhesive layer 213 in order to fix the optical fiber 208 to the package 201 , i.e., the ceramic plate 205 with the microlenses 206 and 207 , which would make it impossible for the optical fiber 208 to remove from the package 201 . Thus, the optical fiber 208 is not removable. If the optical fiber 208 is forcibly removed from the package 201 and the optical fiber 208 is again fixed to the package 201 or another package, the coupling loss fluctuates.
[0035] In FIG. 4, which illustrates a first embodiment of the optical module according to the present invention, an LSI package 1 includes LSI chips (not shown), and surface-emitting laser diodes 11 and surface-receiving PIN photodiodes 12 electrically connected to the LSI chips. For example, the pitch of the laser diodes 11 and the pitch of the PIN photodiodes 12 are 250 μm. The laser diodes 11 and the PIN photodiodes 12 are exposed by a rectangular opening 13 on the upper side of the LSI package 1 . Also, guide recesses 14 -1 and 14 -2 are perforated on the upper side of the LSI package 1 . Further, recesses 15 -1 and 15 -2 are perforated on the sides of the LSI package 1 .
[0036] A microlens array plate 2 includes microlenses 21 corresponding to the laser diodes 12 and the PIN photodiodes 13 . In this case, the microlens array plate 2 can be fitted into the rectangular opening 13 of the LSI package 1 , and the pitch of the microlenses 21 is 250 μm, for example.
[0037] An optical array connector, i.e., a fiber array connector 3 has V-shaped grooves 31 on its bottom side for receiving optical fibers 4 . Also, as illustrated in FIG. 5, a vertical stopper face 32 for stopping the optical fibers 4 and an oblique face 33 having an approximate angle of 45°, and a vertical stopper face 34 for stopping a glass plate 5 are provided in the fiber array connector 3 . Note that a mirror 33 a made of an Au layer is deposited by an evaporation process on the oblique face 33 . Also, guide recesses 35 -1 and 35 -2 corresponding to the guide recesses 14 -1 and 14 -2 of the LSI package 1 are perforated on the bottom side of the fiber array connector 3 .
[0038] Guide pins 6 -1 and 6 -2 are used for aligning the fiber array connector 3 to the LSI package 1 .
[0039] A clamping member 7 is used for clamping (fixing) the fiber array connector 3 to the LSI package 1 . The clamping member 7 is made of adiabatic material and has two nails 71 -1 and 71 -2 corresponding to the recesses 15 -1 and 15 -2 of the LSI package 1 .
[0040] The assembling operation of the optical module of FIG. 4 is explained below.
[0041] First, as indicated by {circle over (1)}, the microlens array plate 2 is fitted into the opening 13 of the LSI package 1 , so that the optical axes of the microlenses 21 are in alignment with these of the laser diodes 11 and the PIN diodes 12 , as illustrated in FIG. 6A.
[0042] Next, as indicated by {circle over (2)}, the optical fibers 4 are fitted into the V-shaped grooves 31 of the fiber array connector 3 , so that the facet of the optical fibers 4 abuts against the vertical stopper face 32 of the fiber array connector 3 , as illustrated in FIG. 6B. In FIG. 6B, note that each of the optical fibers 4 is constructed by a core layer 41 and a clad layer 42 .
[0043] Next, as indicated-by {circle over (3)}, the glass plate 5 is adhered to the optical fibers 4 after a transparent resin layer 8 is fitted into a spacing between the optical fibers 4 and the mirror 33 a, as illustrated in FIG. 6C. In this case, the glass plate 5 abuts against the vertical stopper face 34 of the fiber array connector 3 . As a result, the optical fibers 4 are securely fitted into the V-shaped grooves 31 of the fiber array connector 3 . Note that the transparent resin layer 8 is made of ultraviolet thermosetting adhesives. Therefore, when such adhesives are coated on the upper and lower faces of the optical fibers 4 , the glass plate 5 is surely adhered to the optical fibers 4 . Also, the transparent resin layer 8 serves as a refractive index matching element between the LSI package 1 and the optical fibers 4 , to suppress the spread of light reflected from the mirror 33 a , light from the optical fibers 4 and light to the optical fibers 4 .
[0044] Next, as indicated by {circle over (4)}, the fiber array connector 3 with the optical fibers 4 and the glass plate 5 is moved down while the guide pin 6 -1 is fitted into the guide recesses 14 -1 and 35 -1 and the guide pin 6 -2 is fitted into the guide recesses 14 -2 and 35 -2. Thus, the optical fibers 4 are surely in alignment with the laser diodes 11 and the PIN photodiodes 12 .
[0045] Finally, as indicated by {circle over (5)}, the clamping member 7 clamps the fiber array connector 3 to the LSI package 1 by inserting the nails 71 -1 and 71 -2 into the recesses 15 -1 and 15 -2 of the LSI package 1 . As a result, the fiber array connector 3 couples with the LSI package 1 , as illustrated in FIG. 6D.
[0046] In FIG. 6D, light emitted from the laser diodes 11 is transmitted through the microlenses 21 and the glass substrate 5 , and is reflected by the mirror 33 a to reach the optical fibers 4 . On the other hand, light emitted from the optical fibers 4 is reflected by the mirror 33 a, and is transmitted through the glass plate 5 and the microlenses 21 to reach the PIN diodes 12 .
[0047] The disassembling operation of the assembled optical module of FIG. 5 is carried out just by removing the clamping member 7 therefrom. As a result, the fiber array connector 3 with the optical fibers 4 and the glass plate 5 can be easily separated from the LSI package 1 .
[0048] Thus, in the,first embodiment, since the optical fibers 4 are securely adhered to the LSI package 1 , the coupling efficiency therebetween can be improved. Also, since the fiber array connector 3 with the optical fibers 4 is completely removable from the LSI package 1 , the fluctuation of coupling loss can be suppressed.
[0049] In FIG. 7, which illustrates a first modification of the optical module of FIG. 4, balls 14 ′-1 and 14 ′-2 adhered to the upper face of the LSI package 1 are provided instead of the guide recesses 14 -1 and 14 -2 of FIG. 4, and recesses 35 ′-1 and 35 ′-2 are provided instead of the guide recesses 35 -1 and 35 -2 of FIG. 4. In this case, the guide pins 6 -1 and 6 -2 of FIG. 4 are not provided. As a result, as indicated by {circle over (4)}, the fiber array connector 3 with the optical fibers 4 and the glass plate 5 is moved down while the balls 14 -1 and 14 -2 are fitted into the recesses 35 ′-1 and 35 ′-2. Thus, the optical fibers 4 are also surely in alignment with the laser diodes 11 and the PIN photodiodes 12 .
[0050] In the modification as illustrated in FIG. 7, the balls 14 ′-1 and 14 ′-2 can be provided on the lower face of the fiber array connector 3 and the recesses 35 ′-1 and 35 ′-2 can be provided on the upper face of the LSI package 1 .
[0051] In FIG. 7, since the guide pins 6 -1 and 6 -2 of FIG. 4 are not provided, the optical module of FIG. 7 can be thinner as compared with that of FIG. 4.
[0052] In FIG. 8, which illustrates a second modification of the optical module of FIG. 4, pyramid-shaped protrusions 14 ″-1 and 14 ″-2 adhered to the upper face of the LSI package 1 are provided instead of the guide holes 14 -1 and 14 -2 of FIG. 4, and pyramid-shaped recesses 35 ″-1 and 35 ″-2 are provided instead of the guide recesses 35 -1 and 35 -2 of FIG. 4. In this case, the guide pins 6 -1 and 6 -2 of FIG. 4 are not provided. As a result, as indicated by {circle over (4)}, the fiber array connector 3 with the optical fibers 4 and the glass plate 5 is moved down while the protrusions 14 ″-1 and 14 ″-2 are fitted into the recesses 35 ″-1 and 35 ″-2. Thus, the optical fibers 4 are also surely in alignment with the laser diodes 11 and the PIN photodiodes 12 .
[0053] In the modification as illustrated in FIG. 8, the protrusions 14 ″-1 and 14 ″-2 can be provided on the lower face of the fiber array connector 3 and the recesses 35 ″-1 and 35 ″-2 can be provided on the upper face of-the LSI package 1 . However, if the fiber array connector 3 is made of monocrystalline silicon, the recesses 35 ″-1 and 35 ″-2 can be easily formed by an anisotropy etching process.
[0054] Even in FIG. 8, since the guide pins 6 -1 and 6 -1 of FIG. 4 are not provided, the optical module of FIG. 8 can be thinner as compared with that of FIG. 4.
[0055] In FIG. 9, which illustrates a second embodiment of the optical nodule according to the present invention, an optical waveguide, array 4 ′ is provided instead of the optical fibers 4 of FIG. 4, and a recess 31 ″ is provided instead of the V-shaped grooves 31 of FIG. 4 in an optical array connector 3 ′. Assembling and disassembling operation of the optical module of FIG. 9 can be carried out in a similar way as in the optical module of FIG. 4. Also, the modifications of FIGS. 7 and 8 can be applied to the optical module of FIG. 9.
[0056] In FIG. 10, which illustrates a third embodiment of the optical module according to the present invention, a capillary 31 ″ is provided instead of the V-shaped grooves 31 of FIG. 4, Assembling and disassembling operation of the optical module of FIG. 10 can be carried out in a similar way as in the optical module of FIG. 4. Also, the modifications of FIGS. 7 and 8 can be applied to the optical module of FIG. 10.
[0057] In the above-described embodiments, the package 1 is manufactured by a transfer molding process using resin, so that the guide holes 14 -1 and 14 -2 (the balls 14 ′-1 and 14 ′-2 the protrusions 14 ″-1 and 14 ″-2) and the recesses 15 -1 and 15 -2 can be simultaneously formed. On the other hand, the fiber array connector 3 (optical array connector 3 ′) is manufactured by a transfer molding processing resin, so that the V-shaped grooves 31 , vertical stopper face 32 , the oblique face 33 and the vertical stopper face 33 , the guide recesses 35 -1 and 35 -2 (the recesses 35 ′-1, ; 35 ′-2, 35 ″-1 and 35 ″-2) can be simultaneously formed,
[0058] As explained hereinabove, according to the present invention, since the alignment of an optical array connector (fiber array connector) to a package does not fluctuate, the coupling efficiency can be improved. Also, since the optical array connector is completely removable from the package, the fluctuation of the coupling loss can be suppressed. | In an optical module, a package includes an array of first optical elements and at least one first positioning member. A microlens array plate including microlenses is fixed to the package, so that each of the microlenses corresponds to one of the first optical elements.
An optical array connector mounts second optical elements thereon. The optical array connector has a light path bending portion for bending light paths of the second optical elements and at least one second positioning member.
The optical array connector abuts against the package by aligning the second positioning member to the first positioning member so that each of the first optical elements corresponds to one of the second optical elements, A clamping member clamps the optical, array connector to the package. | 6 |
FIELD OF THE INVENTION
The present invention relates to Helicopters and Fixed Wing Aircraft and more particularly to the protection of parked aircraft from high winds.
BACKGROUND OF THE INVENTION
Wind damage and even destruction of helicopters and other light aircraft parked on unprotected parking aprons, ramps, and other open sites is a common occurrence. In one recent documented case that occurred at Fort Hood, Tex. on 13 May 1989, a large thunderstorm which produced winds in excess of 60 miles per hour resulted in damage to U.S. Army aircraft estimated to be one-half billion dollars. It also resulted in an enormous burden to the taxpayer and significantly effected the readiness of the nations fighting forces. Although this and other damage from similar occurrences cannot be entirely eliminated, it can be significantly reduced. Current methods used to secure parked aircraft employ tie down devices or placing the aircraft in a protective hangar. The tie down devices have proved to be of limited protection in light to moderate wind conditions but have proven to be ineffective in extreme winds such as mentioned above. Hangars are the ultimate answer but are not always available due to space requirements and cost. The relative flexibility of helicopter rotorblades makes them particularly susceptible to damage. Much of the flexing of these blades is due to the lift they generate as a result of high winds blowing across their surfaces. Even though they are tied down, there is a tremendous tendency to flex up and down causing undue and excessive stress in the entire structure of the blade and the structure to which it is attached. The same stress is exhibited in smaller fixed wing aircraft. Should a tie down device come loose, the airfoil is free to fly. In the case of the helicopter it will flex up and damage the rotorblade itself and other rotor components. Small fixed wing aircraft will become ariborne and possibly be destroyed or damaged by turning over. The major objective of the present invention is to provide a portable, low cost, and effective system for reducing the damage to these aircraft by destroying the lift generating surfaces of the airfoil caused by high relative wind conditions such as that associated with storm gusts and sustained winds.
Previous designs which require many moving parts such as multiple hinges and pins rely on the wind to activate the spoiler system. This system would be subject to failure in the event the metal hinges and pins corrode, bend, or if the system is frozen in the down position caused by ice, snow, or freezing rain conditions. This would leave the aircraft unprotected and the system useless against those winds normally associated with the above mentioned conditions. Previous designs are of such material and size that would either not conform to larger airfoils that droop, as in any large multi-bladed helicopter or require multiple spoilers. One such previous invention described the preferred length to be two feet. This would create an installation problem insofar as the amount of time it would take to install the system, and the fact that the smaller system would require multiple spoilers to adequately perform the purpose it was intended to do. Example in point: The Boeing B-234/U.S. Army CH-47 medium lift helicopter has six main rotorblades which are approximately 28 feet in length. It would require approximately 12 of the above mentioned spoilers per rotorblade with a total of 72 devices to equip the entire aircraft to protect it adequately. This may also prove to be costly when outfitting an entire fleet or even one aircraft for a small owner/operator. Previous designs also appear to be designed with only the small fixed-wing aircraft in mind. The current invention will satisfy the needs of the larger aircraft and the smaller as well. The current invention consists of 3 parts, none moving, and is handled as one modular unit for easy installation and removal. It has application to any size or design airfoil.
SUMMARY OF THE INVENTION
In accordance with the present invention, a removable spoiler is provided. The spoiler is to be temporarily mounted on the rotorblade or wing of a parked aircraft to protect it from high wind damage. The invention consists of three basic components: cover, aircell chamber, and the aircell. It is handled, installed, and removed as a modular unit. It is stored as one unit per rotorblade or wing by folding or rolling. Simplicity of design also means no moving parts to wear out, corrode, or freeze in place. The invention is operational at all times when installed. Installation of the present invention is preferably sliding the cover over the end of the rotorblade or wing with the aircell on top, pulling it to the blade or wing root and securing it with the securing straps. Further security will be provided by its inherent design; when the aircell is inflated it will tend to take up any looseness as it expands. Once installed over the intended airfoil, a pneumatic hose will be connected to the air-valve on the aircell thence inflating the aircell to form its spoiler shape. In the preferred form of the invention the protection cover and the aircell chamber consists of a strong, light-weight fabric, reinforced by double and triple stitching where needed. The aircell may consist of a rubber-like material. The device would also include a fabric repair kit consisting of adequate sheet material, needle, and thread and an aircell kit consisting of adequate material to repair the aircell.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a view of inflated lift spoiler installed.
FIG. 2 is a perspective of an inflated aircell.
FIG. 3 is a top view similar to FIG. 1.
FIG. 4 cross sectional view.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purpose of promoting an undestanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. Shown in the figures is an airfoil of cambered design, that of being a typical helicopter rotor blade 11, which illustrates a typical application of the invention, but is not limited to such application, and as such is applicable to any airfoil on any type of aircraft. FIG. 1 illustrates the typical rotorblade 11, rotorblade grip 10, and rotorblade retaining bolt 18. When parked, the rotorblade 11 is secured by means of a rotorblade tiedown 14 which is attached to the rotorblade 11 which is fastened either to a hard point on the aircraft or the ground.
In accordance with the present invention, a portable environmental protection cover 15 is mounted on each rotorblade. The number of environmental protection covers mounted will correspond to the number of rotorblades per aircraft. Each environmental protection cover 15 is identical and, therefore, only one will be described in detail.
The environmental protection cover 15 is composed of an elongated envelope made of strong, light-weight sheet fabric material conforming to the shape of the rotorblade 11. The cover 15 is left open at the blade grip 10 end to allow the cover 15 to be slipped over the end of the rotorblade 11, thus providing complete protection for the entire length of the rotorblade 11. The cover 15 is secured to the rotorblade 11 by means of securing devices 17 on the blade grip end of cover 15. Attached to the top of the cover 15 is the aircell chamber 12 made of the same material as the cover 15 and is only slightly shorter in length than the cover 15. The aircell chamber 12 provides a housing and protection for the aircell 13 which is made of an inflatable air retaining material designed to retain its designed shape for spoiling once inflated and conforms to the length of the aircell chamber 12. The aircell 13 is inflated through an airvalve 16. The employment of the removable lift spoiler will now be described. The cover 15 with the aircell 13 in place within the aircell chamber 12 is introduced over the end of the rotorblade 11 and slid toward the bladegrip 10. After the cover 15 is in place the securing straps are tightened and secured with fasteners. A device supplying air under pressure is attached to the airvalve 16 by means of a flexible pneumatic hose and the aircell 13 is inflated, providing the desired airfoil spoiler shape. The effect of placing the aircell 13 on the top of the rotorblade is to move the air boundary layer separation point to the front of the airfoil, thus putting the airfoil into a full stall and producing little or no lift. The invention helps prevent storm or wind damage by reducing the amount of lift produced by high wind across the airfoil, thus reducing excessive blade or wing movement. The aircell 13 is easily and quickly deflated and the removalbe lift spoiler cover 15 is then easily removed for storage by sliding it off the rotorblade 11 from the tie down end 14. Normal storage would be by simply rolling or folding the environmental protection cover 15 with the collapsed aircell 13 deflated and held in place by the aircell chamber 12. At this point it can be stored and transported easily.
The present invention provides an important advantage over other design methods of protecting parked aircraft from wind damage insofar as it is simplistic, yet effective design with no moving parts, its adequately designed to fit the airfoils in use now that require a faster and more protective spoiler system which can be placed on an aircraft in a very short period of time, is cost effective, and is actively protecting the aircraft all of the time once installed. It does not rely on the wind to activate it, nor does this invention require multiple spoilers as some previously earlier designed systems would require, thus reducing the aircraft owners expense. To those skilled in the art, it is apparent that this invention has many variations within the scope of the appended claims once the principles described above ar understood. | A removable spoiler is described for reducing the rotorblade or wing lift of parked aircraft. It includes an airfoil cover with an inflatable aircell installed that is temporarily mountable to project into the airflow on the top of the rotorblade or wing. It extends for the greater portion of the lift generating surface of the rotorblade or wing to which applied. | 1 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a device for converting an electrical current with at least one phase module, which has an AC voltage connection and at least one DC voltage connection, a phase module branch being formed between each DC voltage connection and the AC voltage connection, and each phase module branch having a series circuit comprising submodules, which each have an energy storage device and at least one power semiconductor and with closed-loop control means for regulating the device.
Such a device is already known, for example, from the work by A. Lesnicar and R. Marquardt “An Innovative Modular Multilevel Converter Topology Suitable for a Wide Power Range”, which appeared on Powertech 2003. This paper discloses a power converter, which is intended to be connected to an AC voltage system. The power converter has a phase module for each phase of the AC voltage system to be connected to it, each phase module having an AC voltage connection and two DC voltage connections. Phase module branches extend between each DC voltage connection and the AC voltage connection such that a so-called 6-pulse bridge circuit is provided. The module branches comprise a series circuit of submodules, which each comprise two disconnectable power semiconductors, with which in each case inverse freewheeling diodes are connected in parallel. The disconnectable power semiconductors and the freewheeling diodes are connected in series, with a capacitor being provided in parallel with said series circuit. Said components of the submodules are wired to one another such that either the capacitor voltage or the voltage zero drops across the two-pole output of each submodule.
The disconnectable power semiconductors are controlled by means of so-called pulse width modulation. The closed-loop control means for controlling the power semiconductors have measuring sensors for detecting currents whilst obtaining current values. The current values are supplied to a central control unit, which has an input interface and an output interface. A modulator, i.e. a software routine, is provided between the input interface and the output interface. The modulator has, inter alia, a selector unit and a pulse width generator. The pulse width generator generates the control signals for the individual submodules. The disconnectable power semiconductors are changed over from an on setting, in which a current flow via the disconnectable power semiconductors is made possible, to an off setting, in which a current flow via the disconnectable power semiconductors is interrupted, by means of the control signals generated by the pulse width generator. In this case, each submodule has a submodule sensor for detecting a voltage drop across the capacitor.
Further papers relating to the control method for a so-called multi-level power converter topology are those by R. Marquardt, A. Lesnicar, J. Hildinger “Modulares Stromrichterkonzept für Netzkupplungsanwendung bei hohen Spannungen” [Modular power converter concept for power supply system coupling application in the case of high voltages], presented at the ETG technical conference in Bad Nauenheim, Germany 2002, by A. Lesnicar, R. Marquardt, “A new modular voltage source inverter topology”, EPE' 03 Toulouse, France 2003 and by R. Marquardt, A. Lesnicar “New Concept for High Voltage Modular Multilevel Converter”, PESC 2004 Conference in Aachen, Germany.
The German patent application 10 2005 045 090.3, which is as yet unpublished, has disclosed a method for controlling a polyphase power converter with distributed energy storage devices. The disclosed device likewise has a multi-level power converter topology with phase modules, which have an AC voltage connection arranged symmetrically in the center of each phase module and two DC voltage connections. Each phase module comprises two phase module branches, which extend between the AC voltage connection and one of the DC voltage connections. In turn, each phase module branch comprises a series circuit of submodules, each submodule comprising disconnectable power semiconductors and freewheeling diodes connected back-to-back in parallel therewith. In addition, each submodule has a unipolar capacitor. Closed-loop control means are used for regulating the power semiconductors, which closed-loop control means are also designed to set branch currents which flow between the phase modules. By controlling the branch currents, current oscillations, for example, can be actively damped and operating points at lower output frequencies can be avoided. Furthermore, uniform loading of all of the disconnectable semiconductor switches and symmetrization of very asymmetrical voltages can be brought about.
The submodules of the phase modules generate in each case discrete output voltages, with the result that, given unequal voltage ratios between the phase modules, circulating currents can be brought about between the individual phase modules. These circulating currents are dependent on the ratio of the voltages applied to the inductances within the current path, in addition to the switching frequency at which the power semiconductors are switched. At low switching frequencies of below 200 Hz, the circulating currents can barely be managed in terms of regulation technology in the case of small inductances and cannot be avoided.
BRIEF SUMMARY OF THE INVENTION
The object of the invention is therefore to provide a device of the type mentioned at the outset with which circulating currents can be controlled and reduced in a targeted manner.
This object is achieved according to the invention by virtue of the fact that each phase module has at least one inductance, the closed-loop control means being designed to regulate a circulating current, which flows via the phase modules.
According to the invention, each phase module has at least one inductance. The inductances are designed such that targeted regulation of the circulating currents is made possible by means of the closed-loop control means. In other words, the inductances are matched to the respectively present conditions, such as the DC voltage applied, the AC voltage applied or the like. The regulation predetermines desired circulating voltage setpoint values, which are applied during the regulation of the associated phase module branch as the setpoint value, for example other setpoint voltages of the phase module branch affected, and thus ensure a desired circulating current. In this case, the regulation advantageously has a current regulator and an associated drive unit for each phase module branch. The current regulator is connected to the submodules of the respective phase module branch only via the drive unit, but not directly. In this case, the current regulator generates, for example, a branch voltage setpoint value, which is made available to the drive unit. The drive unit provides control signals, which are supplied to the disconnectable power semiconductors of the submodules, with the result that a total voltage drop across the submodules of the associated phase module branch corresponds to the branch setpoint voltage as precisely as possible. The application of the circulating voltage setpoint values to other setpoint voltages of the respective phase module branch takes place by means of the current regulator, which combines said setpoint values with one another in linear fashion, i.e. by means of summation and/or subtraction. The result of this linear combination is branch voltage setpoint values, which are each associated with a phase module branch.
Since each phase module branch has an identical inductance, the required symmetry in terms of regulation technology is provided.
Advantageously, each phase module branch is connected to the AC voltage connection via an inductance. According to this expedient development, the AC voltage connection is arranged between two inductances.
In accordance with a development which is expedient in this regard, the inductances of the phase module are coupled to one another. The coupling increases the total inductance, with the result that the individual inductances in terms of their values, i.e. their inductance, can be correspondingly lowered. In this way, costs are saved. In other words, smaller inductors or coils can be used in the phase module. The total inductance achieved by the coupling in addition affects only the circulating currents and at best the DC components of the phase module branch currents. The inductance for AC-side phase currents is reduced by the coupling of the inductances, however.
The coupling of the inductances can take place via air, via an iron core or the like.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Further advantages and configurations are the subject matter of the description below relating to exemplary embodiments of the invention with reference to the figures in the drawing, in which identical reference symbols relate to functionally identical component parts and in which:
FIG. 1 shows an exemplary embodiment of a device according to the invention in a schematic illustration,
FIG. 2 shows an equivalent circuit diagram of a submodule of a device as shown in FIG. 1 ,
FIG. 3 shows the device shown in FIG. 1 with coupled inductances,
FIG. 4 shows an enlarged illustration of the coupling of the inductances,
FIG. 5 shows the structure of the closed-loop control means of the device shown in FIG. 1 , and
FIG. 6 shows the application of circulating voltage setpoint values to other setpoint values of the closed-loop control means.
DESCRIPTION OF THE INVENTION
FIG. 1 shows an exemplary embodiment of the device 1 according to the invention which comprises three phase modules 2 a, 2 b and 2 c. Each phase module 2 a, 2 b and 2 c is connected to a positive DC voltage line p and to a negative DC voltage line n, with the result that each phase module 2 a, 2 b, 2 c has two DC voltage connections. In addition, in each case one AC voltage connection 3 1 , 3 2 and 3 3 is provided for each phase module 2 a , 2 b and 2 c. The AC voltage connections 3 1 , 3 2 and 3 3 are connected to a three-phase AC voltage system 5 via a transformer 4 . The phase voltages U 1 , U 2 and U 3 drop across the phases of the AC voltage system 5 , with system currents In 1 , In 2 and In 3 flowing. The AC-voltage-side phase current of each phase module is denoted by I 1 , I 2 and I 3 . The DC voltage current is I d . Phase module branches 6 p 1 , 6 p 2 and 6 p 3 extend between each of the AC voltage connections 3 1 , 3 2 or 3 3 and the positive DC voltage line p. The phase module branches 6 n 1 , 6 n 2 and 6 n 3 are formed between each AC voltage connection 3 1 , 3 2 , 3 3 and the negative DC voltage line n. Each phase module branch 6 p 1 , 6 p 2 , 6 p 3 , 6 n 1 , 6 n 2 and 6 n 3 comprises a series circuit of submodules (not illustrated in detail in FIG. 1 ) and an inductance, which is denoted by L Kr in FIG. 1 .
FIG. 2 illustrates the series circuit of the submodules 7 and in particular the design of the submodules by means of an electrical equivalent circuit diagram in more detail, with only the phase module branch 6 p 1 being singled out in FIG. 2 . The rest of the phase module branches have an identical design, however. It can be seen that each submodule 7 has two disconnectable power semiconductors T 1 and T 2 connected in series. Disconnectable power semiconductors are, for example, so-called IGBTs, GTOs, IGCTs or the like. They are known to a person skilled in the art as such, with the result that a detailed illustration is not required at this juncture. A freewheeling diode D 1 , D 2 is connected back-to-back in parallel with each disconnectable power semiconductor T 1 , T 2 . A capacitor 8 is connected as the energy storage device in parallel with the series circuit of the disconnectable power semiconductors T 1 , T 2 or the freewheeling diodes D 1 and D 2 . Each capacitor 8 is charged in unipolar fashion. Two voltage states can now be generated at the two-pole connection terminals X 1 and X 2 of each submodule 7 . If, for example, a drive signal is generated by a drive unit 9 , with which drive signal the disconnectable power semiconductor T 2 is changed over into its on setting, in which a current flow via the power semiconductor T 2 is made possible, the voltage drop across the terminals X 1 , X 2 of the submodule 7 is zero. In this case, the disconnectable power semiconductor T 1 is in its off setting, in which a current flow via the disconnectable power semiconductor T 1 is interrupted. This prevents the discharge of the capacitor 8 . If, on the other hand, the disconnectable power semiconductor T 1 is changed over to its on setting, but the disconnectable power semiconductor T 2 is changed over to its off setting, the full capacitor voltage Uc is present at the terminals X 1 , X 2 of the submodule 7 .
The exemplary embodiment of the device according to the invention shown in FIGS. 1 and 2 is also referred to as a so-called multi-level power converter. Such a multi-level power converter is suitable, for example, for driving electrical machines, such as motors or the like, for example. Furthermore, such a multi-level power converter is also suitable for use in the sector of energy distribution and transmission. Thus, the device according to the invention is used, for example, as a back-to-back link, which comprises two power converters which are connected to one another on the DC-voltage side, the power converters each being connected to an AC voltage system. Such back-to-back links are used for the exchange of energy between two energy distribution systems, the energy distribution systems having, for example, a different frequency, phase angle, neutral-point connection or the like. Furthermore, applications in the field of wattless power compensation as so-called FACTS (Flexible AC Transmission Systems) come into consideration. High-voltage DC transmission over long distances is also conceivable with such multi-level power converters.
The inductances L Kr are used for limiting the currents flowing via the respective phase module and therefore for protecting the disconnectable power semiconductors T 1 , T 2 and the freewheeling diodes D 1 and D 2 of the submodules 7 from overcurrents. In the context of the invention, however, the respective inductance is selected to be so high that active regulation of the circulating currents which flow between the phase modules is made possible. In the context of the invention, therefore, inductances are required which are higher than those which are sufficient merely for protecting the power semiconductors. Furthermore, a symmetrical distribution of the inductances over the phase module branches with a view to regulation is advantageous.
FIG. 3 shows the device shown in FIG. 1 , but with the inductances L Kr of a phase module being coupled to one another. As a result of this coupling, the inductances may be lower than in the exemplary embodiment shown in FIG. 1 given the same rated voltages and the same use conditions. In other words, the coupling provides the possibility of reducing the inductors or coils required for construction in terms of their physical size and the rest of their configuration. On the basis of a coupling factor K for the magnetic coupling, the following results for the effective inductance of a phase module branch in the circulating current direction L K :
L K =L L (1 +K ),
where L L corresponds to the inductance of the sum of the individual inductances which are not coupled to one another. The phase module branch currents comprise, in addition to the circulating currents, DC current components and phase currents I 1 , I 2 and I 3 flowing between the AC voltage connections 3 1 , 3 2 , 3 3 and the connected AC voltage system. An increased inductance results only for the DC components and the circulating currents. The inductance L CONV for the phase currents I 1 , I 2 and I 3 is reduced, however, by the coupling in accordance with
L CONV =L L (1− K ).
In this way, circulating currents can be reduced and can be supplied for active regulation. The coupling can take place via air, but also via an iron core or the like. In the case of air-core inductors, coupling factors of up to 20% can be produced. In addition to the damping of the circulating currents, the coupled inductances also ensure improved splitting of the phase currents into identical components between the phase module branches of the same phase module.
FIG. 5 illustrates the structure of the closed-loop control means. The closed-loop control means comprise a current regulator 10 and drive units 9 p 1 , 9 p 2 , 9 p 3 and 9 n 1 and 9 n 2 and 9 n 3 . Each of the drive units is associated with a phase module branch 6 p 1 , 6 p 2 , 6 p 3 , 6 n 1 , 6 n 2 and 6 n 3 , respectively. The drive unit 9 p 1 is, for example, connected to each submodule 7 of the phase module branch 6 p 1 and generates the control signals for the disconnectable power semiconductors T 1 , T 2 . A submodule voltage sensor (not illustrated in the figures) is provided in each submodule 7 . The submodule voltage sensor is used for detecting the capacitor voltage drop across the capacitor 8 as the energy storage device of the submodule 7 whilst obtaining a capacitor voltage value Uc. The capacitor voltage value Uc is made available to the respective drive unit, in this case 9 p 1 . The drive unit 9 p 1 therefore obtains the capacitor voltage values of all of the submodules 7 of the phase module branch 6 p 1 associated with it and summates these values to obtain a branch energy actual value or in this case branch voltage actual value UcΣp 1 , which likewise is associated with the phase module branch 6 p 1 . This branch voltage actual value UcΣp 1 is supplied to the current regulator 10 .
Moreover, the current regulator 10 is connected to various measuring sensors (not illustrated in the figures). Thus, current transformers arranged on the AC-voltage side of the phase modules 2 a, 2 b, 2 c are used to generate and supply phase current measured values I 1 , I 2 , I 3 and current transformers arranged at each phase module are used to generate and supply phase module branch currents Izwg and a current transformer arranged in the DC voltage circuit of the power converter is used to provide DC current measured values Id. Voltage transformers of the AC system provide system voltage measured values U 1 , U 2 , U 3 and DC voltage transformers provide positive DC voltage measured values Udp and negative DC voltage measured values Udn, the positive DC voltage values Udp corresponding to a DC voltage drop between the positive DC voltage connection p and ground, and the negative DC voltage values Udn corresponding to a voltage drop between the negative DC voltage connection and ground.
The current regulating unit 10 is also supplied setpoint values. In the exemplary embodiment shown in FIG. 5 , the regulating unit 10 is supplied an active current setpoint value Ipref and a wattless current setpoint value Iqref. In addition, a DC voltage setpoint value Udref is applied to the input of the current regulating unit 10 . Instead of a DC voltage setpoint value Udref, the use of a DC setpoint value Idref is also possible in the context of the invention.
The setpoint values Ipref, Iqref and Udref and said measured values interact with one another when using different regulators, with a branch voltage setpoint value Up 1 ref, Up 2 ref, Up 3 ref, Un 1 ref, Un 2 ref, Un 3 ref being generated for each drive unit 9 p 1 , 9 p 2 , 9 p 3 , 9 n 1 , 9 n 2 and 9 n 3 . Each drive unit 9 generates control signals for the submodules 7 associated with it, with the result that the voltage drop Up 1 , Up 2 , Up 3 , Un 1 , Un 2 , Un 3 across the series circuit of the submodules corresponds to the respective branch voltage setpoint value Up 1 ref, Up 2 ref, Up 3 ref, Un 1 ref, Un 2 ref, Un 3 ref as far as possible.
The current regulator 10 forms suitable branch voltage setpoint values Up 1 ref, Up 2 ref, Up 3 ref, Un 1 ref, Un 2 ref, Un 3 ref from its input values.
FIG. 6 shows that, for example, the branch voltage setpoint value Upref is calculated by linear combination of a system phase voltage setpoint value Unetz 1 , a branch voltage intermediate setpoint value Uzwgp 1 , a DC voltage setpoint value Udc, a symmetrizing voltage setpoint value Uasym and a balancing voltage setpoint value Ubalp 1 . This takes place for each of the phase module branches 6 p 1 , 6 p 2 , 6 p 3 , 6 n 1 , 6 n 2 , 6 n 3 independently of one another. The circulating currents can be set in a targeted manner using the branch voltage intermediate setpoint values Uzwg in conjunction with the set branch inductances. The balancing voltage setpoint values Ubal are also used for compensating for asymmetries as regards the energies stored in the phase module branches 6 p 1 , 6 p 2 , 6 p 3 , 6 n 1 , 6 n 2 , 6 n 3 . | A device for converting an electrical current includes at least one phase module with an AC voltage connection and at least one DC voltage connection, a phase module branch disposed between each DC voltage connection and the AC voltage connection and each phase module branch having a series circuit of submodules, each of which has an energy accumulator and at least one power semiconductor and closed-loop control means for regulating the device. The device can regulate circulating currents in a targeted manner by providing each phase module with at least one inductance and configuring the closed-loop control means to regulate a circulating current that flows through the phase modules. | 7 |
FIELD OF THE INVENTION
The present invention relates to continuous time (CT) filters. Specifically, the present invention relates to a type of CT filter known as a transconductancecapacitance (G m -C) filter. In accordance with the invention, modified FET transconductor elements and a feedback loop are utilized to increase the control range of the transconductor elements and provide a desired frequency response for the filter.
BACKGROUND OF THE INVENTION
CT filters are used in a variety of direct signal processing applications where high speed and/or low power dissipation are needed. An example of an appropriate application of CT filters in direct signal processing is the read channel of a disk drive whose requirements for speed and power are such that CT filters are preferred. Other applications for CT filters include receivers, which receive data from local area networks or high speed data links, and wireless communication systems.
One type of CT filter is known as a G m -C filter. Such filters are discussed in detail in Tsividis "Integrated Continuous-Time Filter Design: an Overview" IEEE Journal of Solid State Circuits, Vol. 29, No. 3, March 1994, and Schaumann et al. "Design of Analog Filters" Prentice Hall, Englewood Cliffs, N.J., pp 457-485, the contents of which are incorporated herein by reference. The basic building block of a G m -C filter is a transconductance amplifier comprising a transconductor element and a capacitor or a pair of capacitors. A transconductor is an element whose output current is linearly related to an input voltage by a transconductance G m . For example, I o =G m · 2V i , where I o is the output current and V i is the input voltage.
An example of a transconductance amplifier integrator 10 is shown in FIG. 1. The amplifier integrator 10 of FIG. 1 comprises the transconductor 12 and the capacitor 14. As indicated above, the output current of the transconductor I o is equal to G m · 2V i . The output voltage V o is given by V o =V i G m /sC where C is the capacitance of the capacitor 14 and s is the complex frequency.
The frequency response of the transconductance amplifier integrator 10 is determined by the control voltage V c which is received as an input 13 in the transconductor 12. The control voltage is used to compensate for transconductor and capacitor variations (e.g., power supply variations, temperature variations, and integrated circuit process parameter variations). These variations are common in FET integrated circuits used to implement G m -C filters.
A transconductor 12 implemented using FETs is shown in FIG. 2. The transconductor 12 comprises two legs 21 and 23. The two legs 21 and 23 have fixed equal current sources 22 and 24. The input voltages +V i and -V i are applied to the gates of the FETs 26 and 28. The control voltage V c is applied to the degeneration FET 30. The voltage V Q is a quiescent voltage. The output current I o flows in the two FETs 26 and 28 in opposite directions.
An integrated circuit G m -C filter implemented using a plurality of transconductance amplifiers is shown in FIG. 3. The filter 40 of FIG. 3 comprises four transconductors 42, 44, 46, 48 and two capacitors 47 and 49. The filter 40 has a low pass output V LP and a bandpass output V BP .
Typically, the control voltage V c for the transconductors in a G m -C filter is generated by a phase-locked-loop (PLL). A circuit 60 in which an exemplary phase-locked-loop is used to generate the control voltage V c is shown in FIG. 4. As shown in FIG. 4, the control voltage for the G m -C filter 40 is generated using the PLL 50. The PLL 50 comprises a phase comparator 52 which receives an external reference signal such as a signal 51 from a crystal oscillator (not shown) and a signal 53 from a voltage-controlled-oscillator (VCO) 54. The phase comparator 52 outputs a frequency incrementing signal FUP and a frequency decrementing signal FDN to a charge pump 56. The FUP signal is generated when the VCO output signal lags the crystal oscillator signal. The FDN signal is generated when the VCO output signal leads the crystal oscillator signal.
Depending on which of the FUP or FDN signals is applied, the charge pump 56 will generate positive or negative current pulses which add to or subtract from the total charge accumulated in a charge accumulating device (e.g. capacitor) 58. The device 58 generates a voltage V c which is dependent on the total charge in the accumulating device 58. This voltage V c is the input voltage to the VCO 54. If V c increases or decreases, the output frequency of the VCO increases or decreases. The voltage V c also serves as the control voltage for the transconductors in the G m -C filter 40 and is used to compensate the transconductors for a variety of parameter variations. Phase-locked-loops of the type described above are disclosed in U.S. Pat. No. 5,126,692 the contents of which are incorporated herein by reference. It should be noted that the VCO 54 may implemented by a voltage-to-current convertor and a current controlled oscillator (ICO).
In general, the VCO 54 is made using the same basic transconductor and capacitor elements as the G m -C filter 40. The same quantity V c used to control these elements in the VCO 54 is used to control the corresponding elements in the main G m -C filter 40.
However, the above described technique for controlling a G m -C filter 40 is limited by the effective control range of the transconductor elements. If the control range is not sufficient, then the gain of the transconductors (I o /V i ) cannot be changed enough to account for all of the possible parameter variations and the filter frequency response will not be correct.
Accordingly, it is an object of the invention to increase the control range of the transconductor elements of a G m -C filter. This makes it possible to maintain the filter frequency response over an increased range of transconductor and capacitor variations.
SUMMARY OF THE INVENTION
In accordance with a preferred embodiment of the invention, the control range of a tranconductor element is increased by adding a second degeneration FET. The G m -C filters may then be formed using transconductors with a second degeneration FET. A control signal is provided for the second degeneration FET of the transconductor elements in the G m -C filter by processing the VCO input signal V c in a signal processing path. The control signal for the second degeneration FET is also fed back to the VCO to control the corresponding transconductor elements in the VCO.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 schematically illustrates a conventional transconductance amplifier.
FIG. 2 is a circuit diagram of conventional transconductor element.
FIG. 3 schematically illustrates a conventional G m -C filter formed from transconductance amplifiers.
FIG. 4 illustrates the use of a PLL to control a G m -C filter.
FIG. 5 illustrates a transconductor with two degeneration FETs, in accordance with an illustrative embodiment of the invention.
FIG. 6 illustrates how to use a PLL to generate control signals for the two degeneration FETs in each transconductor element in a G m -C filter, in accordance with an illustrative embodiment of the invention.
FIG. 7 illustrates the signal processing path used to process a VCO input signal to generate the control signal for the second degeneration FET in a transconductor, in accordance with an illustrative embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, G m -C filters are formed using transconductors with two degeneration FETs rather than one degeneration FET as is the case in the prior art. A transconductor with two degeneration FETs is shown in FIG. 5.
Like the conventional transconductor 12 of FIG. 2, the inventive transconductor 12' of FIG. 5 comprises two legs 21 and 23. The two legs 21 and 23 have equal fixed current sources 22 and 24 and the FETs 26 and 28. The positive input voltage +V i is applied to the gate of the FET 26. The negative input voltage -V i is applied to the gate of the FET 28. (As indicated above, V Q is a quiescent voltage). A negative output current I o flows in the FET 26 and positive output current of the same magnitude flows in the FET 28. A first degeneration FET 30 is connected between the two legs 21 and 23. A control voltage V c is applied to the gate of the degeneration FET 30. As indicated above in connection with FIG. 4, the control voltage V c is the input voltage to a VCO in a PLL.
In accordance with the invention, a second degeneration FET 30' is connected between the legs 21 and 23. A control voltage V c1 is applied to the gate of the FET 30'.
The control voltage V c1 is generated from the voltage V c using a signal processing path. FIG. 6 illustrates a circuit for controlling a G m -C filter made from transconductors of the type shown in FIG. 5. As shown in FIG. 6, a G m -C filter 40' is controlled by a phase-locked-loop 50. The G m -C filter 40' is comprised of transconductors and capacitors (see FIG. 3) with each transconductor having two degeneration FETs (rather than one). Thus, each transconductor has two control voltages, V c for the first degeneration FET and V c1 for the second degeneration FET. The PLL 50 is illustrated in greater detail in FIG. 4 and is discussed in detail above. The voltage V c is the input voltage to the VCO in the PLL 50. The voltage V c1 is generated by the signal processing circuit 80. The voltage V c1 is applied to the main G m -C filter 40'. As indicated above, the VCO in the PLL contains transconductor and capacitor elements corresponding to those in the G m -C filter 40'. Thus, the voltage V c1 is fed back to the PLL 50 to control the second degeneration FET 30' in the transconductor elements therein.
The signal processing circuit 80 is shown in greater detail in FIG. 7. The signal processing circuit 80 comprises a comparator 82, a charge pump 84, a capacitor 86, and amplifier/limiter 88. The comparator compares the voltage V c with a reference voltage V R . When V c exceeds V R , the charge pump 84 generates a current which is applied to a capacitor 86 to slowly increase the voltage of the capacitor 86. When V c is less than V R , the charge pump 84 generates a negative current which is applied to the capacitor 86 to decrease its voltage. The voltage of the capacitor 86 is applied to an amplifier/limiter 88 to generate the control voltage V c1 .
The bandwidth of the feedback path containing the signal processing circuit 80 is set to be lower than the PLL bandwidth to avoid interaction and PLL instability. The combination of the feedback path and the second degeneration FET act to limit the low frequency component of V c to be less than V R .
It should also be noted that the second degeneration FET increases the gain (I o /V i ) of the transconductor when its gate voltage is increased and allows the first degeneration FET to operate at a lower gate voltage.
In short, a G m -C filter is formed using transconductor elements with two degeneration FETs. The filter is compensated by applying a PLL output voltage to the first degeneration FET in each transconductor and by applying to the second degeneration FET a control voltage generated by processing the PLL output voltage in a signal processing circuit.
Finally, the above-described embodiments of the invention are intended to be illustrative only. Numerous alternative embodiments may be devised by those skilled in the art without departing from the spirit and scope of the following claims. | A G m -C filter is formed using transconductor elements having first and second degeneration FETs to which first and second control signals are applied. A phase-locked-loop is used to generate the control signals. The control range of the transconductor elements is increased so that the frequency response of the filter can be maintained over increased ranges of various parameters (e.g., supply voltage variations, temperature variations, etc.) | 7 |
Bisphenols have proven to be of considerable industrial importance. Particularly, the low molecular weight bisphenols obtained by condensing phenol with a ketone are important intermediates for the manufacture of epoxy, polyester, and modified phenolformaldehyde resins.
Methods of manufacturing bisphenols have changed over the years. Various conditions were employed in the beginning, e.g., the use of solvents, or diluents, and adjusting the temperature from room temperature to 90° C. A strong acid, such as concentrated HCl, was the condensing agent of choice although yields of less than 80% were obtained and products were impure.
In 1940, Perkins was awarded a patent (U.S. Pat. No. 2,191,831) on improvements utilizing anhydrous HCl, excess phenol, and controlled temperature. Yield was raised to 97% of theory, product purity reached 92%. The small reduction of water in the system was enough to effect much of the improved yield.
In 1944 Perkins and Bryner taught in U.S. Pat No. 2,359,242 that sulfur and ionizable sulfur compounds could be used to promote the condensation of phenols with ketones. This permitted carrying out the condensation at lower temperatures or more completely than before.
There were still problems with all the above methods. The soluble strong acid catalyst was difficult to remove as was the sulfur compound which also was objectionable because of its odorous nature. Yields were still limited. An equilibrium problem involving water, both that added with the reactants and present as a condensation product, limited yields.
Stoesser and Sommerfield taught in U.S. Pat. No. 2,623,908 an improved purification procedure involving the recovery of a crystallized product which was pure and odorless. As in previous processes, a certain amount of waste was generated in the recovery of excess phenol by distillation and a phenol-water azeotrope had to be dealt with.
With the advent of ion-exchange catalysis, as illustrated by U.S. Pat. No. 3,242,219, and the use of a "promoted" ion exchange resin as shown by U.S. Pat. Nos. 3,394,089 and 3,634,341, the presence of water became a more noticeable problem. Rates were slowed and conversions reduced. The strong acid cationic polymer exchange resins exhibited poor catalytic effects at water levels of more than one to two percent.
Mole ratios and feed rates of reactants across stationary catalyst beds become important in continuous systems to control water content. Recycle streams became larger because of the reduced conversions.
Reducing the water level in a phenol and acetone system would serve to shift the reaction equilibrium toward more product. This can be done mechanically by distillation, but is very costly. Here again, waste streams are produced consisting of water saturated with phenols.
Chemically reducing the water in a reactor or reactor stream would be most desirable. This would serve to eliminate azeotropes while also drying the system, thus increasing rates and yields. Certain unsaturated ethers have the ability of acting as water scavengers. In the phenol-acetone reaction to produce the bisphenol of acetone, bisisopropenylether (BIPE) is uniquely suited as a water scavenger because its reaction product with water is acetone, thus: ##STR1##
SUMMARY OF THE INVENTION
It has now been found that in the process of preparing a bisphenol from a ketone and a phenol having a reactive hydrogen substituted in the para position in the presence of a suitable strong acid catalyst and under the conditions of temperature and mole ratios known to the art, that the by-product water produced can be substantially decreased by replacing all or part of the ketone reactant with a reactive alkenyl ether wherein the olefinic unsaturation is in the alpha position with respect to the ether linkage.
Thus, for example, in the acetone-phenol reaction, by substituting BIPE for the acetone one can eliminate half the water in the product since one mole of water is used up in making acetone from the ether. Thus, instead of the normal acetone-phenol reaction, using 2 moles of phenol and one of acetone, to produce one mole of bisphenol and one mole of water in the product, thus: ##STR2## one employs twice the phenol with one mole of the ether to obtain two moles of bisphenol and the same amount of water in the product, thus: ##STR3## Bisisopropenyl ether can also be utilized in conjunction with acetone in varying amounts to control the water at any concentration desired.
DETAILED DESCRIPTION OF THE INVENTION
The improvement in the process for making bisphenols comprises the use of an alpha-unsaturated alkenyl ether as a substitute for all or a portion of the ketone in its reaction with a phenol in the presence of a suitable strong acid catalyst to make bisphenols. The alkenyl ether can be employed under substantially the same conditions as are known to the art for the reaction of a ketone and a phenol to make bisphenols.
Catalysts useful in the present invention are those suitable strong acids known to the art, including anhydrous HCl (U.S. Pat No. 2,191,831), mineral acids such as concentrated aqueous solutions of HCl and H 2 SO 4 (U.S. Pat. No. 2,359,242), organic sulfonic acids, and the strong cation exchange resins (U.S. Pat. No. 3,242,219) in the acid form.
The promoters, i.e., the sulfur compounds used as additives, such as those used with soluble catalysts, e.g., methyl mercaptan, ethyl mercaptan, and octyl mercaptan, and those modified cation exchange resins which are partially neutralized with sulfur compounds including esters of sulfonic acids with mercapto alcohols, e.g., 1-hydroxy-2-mercaptoethane, and the partial salts of mercaptoethylamine and 2,2-diaminothiazolidine, are also useful in the practice of the present invention.
The temperatures employed are in the range of from about 45° C. to about 120° C., but preferably are maintained from about 45° C. to about 80° C. In a continuous system employing beds of cation exchange resin in the acid form, a feed rate of 1-6 bed volumes per hour is preferred, but as low as 0.2 or as high as 10 bed volumes per hour can be employed. This represents a contact time of from about 6 minutes to about 5 hours.
Any phenol, or substituted phenol, having a hydrogen in the para-position which can be substituted, i.e., active hydrogen, is operable in the process of the present invention. Thus, for example, phenol, ortho- and meta-cresol, 2,6-dimethylphenol, 2,6-dibromophenol, ortho- and meta-chlorophenol and ortho-phenylphenol and other substituted phenols containing alkyl, halogen or other groups, non-reactive under the conditions of the reaction, may be employed.
Alkenyl ethers which can be used in the reaction are those having the formula: ##STR4## wherein R 1 , R 2 , R 3 , and R 4 are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl and aryl groups having from one to 10 carbon atoms. Specific examples of useful reactive alkenyl ethers are bisisopropenyl ether, bisisobutenyl ether, and isopropenylisobutenyl ether.
The following examples illustrate the process of the invention and the comparative examples show the advantages over and relationship to the prior art.
EXAMPLE 1.
Phenol-BIPE Reaction Using Ion Exchange Catalyst
A mixture of phenol and sulfonic acid cation exchange resin, (acetone-dried, nitrogen purged to remove acetone), in acid form (DOWEX 50WX4 resin, H + form*, 4.08 meq/g dry resin) was brought to the desired run temperature in a 1000-ml stirred glass pot. BIPE was added dropwise over a period of time to control the reaction at the desired temperature. Stirring was continued and temperature maintained for a total time of 13/4 to 2 hours at which time the mixture was vacuum distilled to remove phenol, water, and unreacted acetone. The reaction was run at temperatures of 55° and 65° C. Runs 1 and 2 and comparative runs A and B were made using the same times and temperatures, but A and B employed an equivalent amount of acetone in place of the BIPE. Results are shown in Table I.
TABLE I______________________________________Run No. 1 A 2 B______________________________________Phenol (g) 400 400** 400 400Acetone (g) 0 15** 0 15BIPE (g) 12.7** 0 12.7 0Dowex 50WX4 (ml) 70 70 70 70Temperature, °C. 55 55 65 65Time (hrs.) 13/4 13/4 2 2Product% Acetone Con-version bystripping 93.6 65.2 95.0 63.3% o,p-bisphenol A 2.4 1.5 2.8 2.0% Bisphenol inMixture 13.3 9.27 13.5 9.0______________________________________ **Phenol = 4.26 moles, acetone = 0.26 mole and BIPE = 0.13 mole.
EXAMPLE 2
Bisphenol Preparation Using a Soluble Sulfonic acid Catalyst
The reaction was run as in Example 1 except using a soluble catalyst. The same type comparison run as in Example 1 employing acetone (Run C) was also made. To a 1000-ml stirred glass pot containing 470 grams phenol and 16.7 grams BIPE was added 5.0 grams paratoluenesulfonic acid. The pot was heated at 75° C. until the reaction was completed (GC* analysis). A sample was neutralized with DOWEX 1 beads (basic form) and distilled under vacuum to remove phenol, water, and acetone. Results are shown in Table II.
TABLE II______________________________________Run No. 3 C______________________________________Phenol (g) 470# 470Acetone (g) 0 19.6#BIPE (g) 16.7# 0Paratoluene sulfonic acid (g) 5.0 5.0% Bis A in Mixture 11.5 8.8______________________________________ #Phenol = 5.0 moles, acetone = 0.34 mole, and BIPE = 0.17 mole.
The addition of BIPE to a reaction mixture of acetone and phenol in the presence of an acid catalyst will improve acetone conversion by acting as a water scavenger. The following experiment illustrates this:
EXAMPLE 3
BIPE Addition to Phenol-Acetone Reaction Mixture
A mixture of 400 grams (4.26 moles) of phenol, 20 grams (0.345 mole) of acetone, and 70 ml of phenolazeotrope-dried sulfonic acid cation exchange resin in acid form (DOWEX 50WX4 resin, H + form, 4.08 meq/g dry resin) promoted as in Example 1 was brought to equilibrium in a stirred glass pot at 60° C. A 200-gram sample of liquid was removed from the pot. By distilling off excess phenol and water to final conditions of 200° C., 10 mm Hg vac, 7.25 grams of crystalline, light yellow solid was recovered from the distillation pot. This crystalline substance was identified as bisphenol A by elution time on the gel permeation chromatograph (GPC). To the remaining reaction mixture in the pot was added dropwise 17.3 grams (0.177 mole) of bisisopropenyl ether. The temperature rose from 60° to 65° C. The absence of water and rise of acetone was detected by gas chromatograph. After stopping the BIPE addition the temperature fell and water was detected by GC. From 180 grams of reaction mixture was recovered 36 grams of product by distilling off excess phenol and water under vacuum. The crystalline product was identified as bisphenol A by elution time on the GPC. The addition of BIPE raised acetone conversion from 19.4 to 58.2% of theoretical in this example of an ion exchange catalyzed stirred pot.
EXAMPLE 4
Continuous Process
The following experiments shows comparisons among preparations of bisphenol from phenol and acetone (Run D), from a mixture of acetone, BIPE and phenol (Run 4) and BIPE and phenol (Run 5), all in the presence of the catalyst of Example 1. All experiments were run in a small stainless steel continuous system using two consecutive reactors.
The phenol feed rate was approximately ten pounds per hour. The reaction temperature was maintained between 50° and 70° C. Acetone was mixed with the phenol and both were fed together into the system.
BIPE was fed into the top of the first reactor in Run 4 and into the tops of both reactors in Run 5. Results are shown in Table III.
TABLE III______________________________________Run No. 4 5 D______________________________________% Acetone 3.0 0 4% BIPE 2.2 2.2 0% Bis A in Stream 16.0 9.5 11.8% o,p-Bis A 2.9 2.7 2.2% Conversion 68 89 75______________________________________ NOTE: 2.2% BIPE equivalent to 2.7% Acetone. | An improved process for obtaining bisphenols by reaction of a phenol, or substituted phenol having a hydrogen in the para position, and an alkenyl ether, wherein the unsaturation in the ether is in the alpha position, in the presence of a strong acid catalyst. The process gives particularly good results when bisisopropenyl ether is reacted with phenol in the presence of a strong acid cation exchange resin in which part of the exchange sites have been neutralized with 2,2-dimethylthiazolidine. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a monoclonal antibody, or a fragment thereof, for isolating and/or identifying at least one cell population which is selected from the group comprising haematopoietic stem cells, neuronal stem cells, neuronal pre-cursor cells, mesenchymal stem cells and mesenchymal precursor cells.
DESCRIPTION OF THE RELATED ART
[0002] The term “stem cell” denotes, in a general manner, any cell which has not yet differentiated and which possesses the ability both to produce identical descendants and to differentiate into specific developmental lines.
[0003] Adult stem cells have the function of maintaining cell number homeostasis in the tissue concerned, i.e. of replacing cells which have died. For this reason, stem cells are particularly to be found in tissues which are subjected to high stresses. Adult stem cells have been found in a very wide variety of tissues and organs, such as, for example, bone marrow, brain, liver, skin, intestine, cornea, etc.
[0004] In the bone marrow, haematopoietic stem cells produce new cells continuously since these latter cells are constantly required in the blood owing to the limited life span of most of the cells.
[0005] The starting point for the formation of blood cells is the pluripotent, undifferentiated haematopoietic stem cell which is still not determined for a specific function. When stem cells differentiate, precursor cells, which are unable to replicate themselves and only bring a specialized cell type to maturity, are formed first of all. Neither the pluripotent stem cell nor the different intermediate stages are able to fulfill cell-specific haematopoietic functions; it is only the cells which have matured which are able to do this. Progenitor cells which have entered upon a particular differentiation route then also keep to this route until maturation is achieved (commitment).
[0006] In addition to stem cells for haematopoietic cells, stem cell-like cells which are progenitors of nonhaematopoietic tissues are also present in the bone marrow. These progenitors of non-haematopoietic tissues were originally termed, inter alia, tissue culture plastic-adherent cells and have more recently been termed either mesenchymal stem cells or bone marrow stroma cells (MSCs).
[0007] These cells are of interest not only because of their multipotency as regards differentiation; they are also of interest, for example, for their possible use in cell therapy and gene therapy.
[0008] The fact that, under certain conditions, mesenchymal stem cells can also differentiate into nerve cells means that, inter alia, there is a need to be able to distinguish these mesenchymal stem cells from neuronal progenitor cells.
[0009] These neuronal progenitor cells (termed NPCs below) are found in the central nervous system. They also express Nestin and are able to differentiate into neurones, astrocytes and oligodendrocytes.
[0010] Neuronal progenitor cells are CD133-positive; this cell surface marker was originally found on haematopoietic stem cells. However, it has recently been shown that this marker is also expressed by nervous tissue and skeletal muscle tissue. For these reasons, this marker is not suitable for distinguishing between different stem cells or progenitor cells on its own.
[0011] Since, as has been mentioned, haematopoietic stem cells continuously generate new cells in the bone marrow, stem cells coexist with the progenitor cells at the same time in the bone marrow. In the bone marrow, these cells are present in a complex arrangement, thereby making it difficult to identify rare cells. Stem cells and their direct descendants express a phenotype which is virtually identical. For these reasons, it is not possible, either, to identify an ultimate stem cell simply on the basis of visible features.
[0012] The frequency of stem cells in the bone marrow is from 1×10 −5 to 1×10 −6 . In addition, the stem cells are as a rule widely scattered in the given tissue, which means that they are difficult to detect.
[0013] As has been mentioned above, haematopoietic stem cells divide, under certain conditions, into progenitor cells whose further differentiation is to some degree already determined. Depending on the nature and quantity of the cytokines which are present, these myeloid and lymphoid progenitor cells can in turn generate a variety of other progenitor cells which are, however, no longer able to replicate themselves. Examples of cytokines which regulate haematopoiesis are granulocyte colony-stimulating factor (G-CSF), macrophage colony-stimulating factor (M-CSF), several interleukins, stem cell factor (SCF), erythropoietin (EPO), etc.
[0014] In order to investigate the haematopoietic (blood cell-forming) potential of stem cells, relevant human cell populations are transplanted into immunodeficient mice (NOD/SCID mice). If the transplanted cells are stem cells, it is then possible to detect human haematopoiesis in addition to the murine haematopoiesis. This in-vivo assay is used to characterize and identify stem cells by in fact analysing the progeny of individual cells.
[0015] As can be seen from the above, haematopoietic stem cells possess great therapeutic potential and are used in patients in whom the immune system is impaired or completely destroyed.
[0016] FACS (fluorescence-activated cell sorter) can be used, for example, to purify haematopoietic stem cells from the bone marrow. This purification depends on the presence, on the stem cells, of particular cell surface proteins which distinguish the haematopoietic stem cells and the progenitor cells from other cell types and on the absence of other cell surface proteins, these latter proteins then being characteristic for differentiated haematopoietic cells. Each of the surface proteins binds a different monoclonal antibody, with each of these antibodies being conjugated to a different fluorescent dye, thereby making it possible to use FACS to separate the cells.
[0017] The cell surface marker CD34, in particular, has been used in the past for isolating haematopoietic stem cells.
[0018] In addition, antibodies directed against the antigen CD133 have recently been used for characterizing haematopoietic stem cells. Miraglia et al., “A novel five-transmembrane hematopoietic stem cell antigen: isolation, characterization and molecular cloning”, Blood 90: 5013-5021, (1997) have shown that this antigen is a 120 kDa glycoprotein which possesses five transmembrane domains and which is expressed not only on haematopoietic stem cells and their progenitors but also on neuronal and endothelial stem cells.
[0019] CD133 antibodies are used, in addition to the conventional CD34 antibodies, for positively selecting haematopoietic stem cells and progenitor cells on a clinical scale. CD133 is only expressed on CD34 bright (high fluorescence intensity) stem cells and progenitor cells. CD34 bright CD133-positive cells are in the main negative for other erythroid progenitor cell markers such as CD36 and glycophorin A. In addition to stem cells which induced human haematopoiesis in: the NOD/SCID mouse model, the majority of granulocyte/macrophage progenitor cells have also been found in CD133-positive fractions derived from human bone marrow and peripheral blood.
SUMMARY OF THE INVENTION
[0020] In view of the above, it is an object of the present invention to provide a novel monoclonal antibody which can be used to selectively isolate and/or characterize particular cell populations, in particular haematopoietic stem cells and also neuronal and mesenchymal stem and progenitor cells.
[0021] According to the invention, this object is achieved by means of a monoclonal antibody, or a fragment thereof, with the antibody, or the fragment thereof, binding to the same antigen as does an antibody which is produced by the hybridoma cell lines as CUB1, CUB2, CUB3 and CUB4, which were deposited in the Deutsche Sammlung fur Mikroorganismen and Zellkulturen [German collection of microorganisms and cell cultures] (DSMZ), in accordance with the Budapest treaty, under the numbers DSM ACC2569, DSM ACC2566 and DSM AC2565, on Aug. 14, 2002, and DSM ACC2551, on Jul. 12, 2002.
[0022] These deposits were made under the provisions of the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purposes of Patent Procedure and the Regulations thereunder (Budapest Treaty). This assures maintenance of a viable culture of the deposit for 30 years from date of deposit. The deposit will be made available by DSMZ under the terms of the Budapest Treaty, and subject to an agreement between Applicant and DSMZ which assures permanent and unrestricted availability of the progeny of the culture of the deposit to the public upon issuance of the pertinent U.S. patent or upon laying open to the public of any U.S. or foreign patent application, whichever comes first, and assures availability of the progeny to one determined by the U.S. Commissioner of Patents and Trademarks to be entitled thereto according to 35 USC §122 and the Commissioner's rules pursuant thereto (including 37 CFR §1.14). Availability of the deposited strains is not to be construed as a license to practice the invention in contravention of the rights granted under the authority of any government in accordance with its patent laws.
[0023] The object underlying the invention is fully achieved in this way.
[0024] The inventors were able to demonstrate, in their own experiments, that it is possible to use the novel antibodies according to the invention to isolate and characterize haematopoietic stem cells, mesenchymal stem cells and progenitor cells and neuronal stem cells and progenitor cells. In addition to this, the selectivity of the novel antibodies was found to be similar to that of an antibody directed against CD133.
[0025] One object of the invention relates, in particular, to monoclonal antibodies, or fragments thereof, which are produced by the hybridoma cell lines CUB 1, CUB2, CUB3 and CUB4.
[0026] The inventors were surprisingly able to isolate the antibodies using the antigen CDCP1.
[0027] CDCP1 is a plasma membrane protein which possesses three potential “CUB” domains. These domains are immunoglobulin-like domains which are designated by the initial letters of the first three molecules possessing such domains which were identified. Proteins which possess these domains are known to be preferentially expressed in the embryonic stage and in early developmental stages.
[0028] The CDCP1 gene encoding this protein (“CUB domain-containing protein”; SEQ ID NO: 1) has been described by Scherl-Mostageer et al., “Identification of a novel gene, CDCP1, overexpressed in human colorectal cancer”, Oncogene 20: 4402-4408, (2001). This research group showed that this protein, or its mRNA, is strongly over-expressed in cancer types or tumours such as intestinal cancer and lung cancer. On the basis of its three-dimensional structure, it was identified as being a transmembrane protein which possessed three CUB domains in the extracellular domain, and the authors proposed that it was involved, in particular, in cell adhesion or interaction with the extracellular matrix (see Scherl-Mostageer et al.).
[0029] However, the possibility that this protein might also be expressed, in particular, on primitive haematopoietic stem cells in the bone marrow and peripheral blood and also on mesenchymal or neuronal stem cells and progenitor cells is neither reported nor suggested in this publication.
[0030] Instead of the antibody which is in each case mentioned, it is according to a further object also possible, within the context of the present invention, to use a fragment of the antibody without this in each case being expressly mentioned. In this connection, fragment” is understood as meaning any fragment of the antibody which retains the antigen-binding function of the antibody. Examples of such fragments are F ab , F (ab′)2 , F v and other fragments such as CDR (“complementarity-determining region”, hypervariable region) fragments. The said fragments exhibit the binding specificity of the antibody and can also be prepared recombinantly, for example using known methods.
[0031] The inventors were able to demonstrate that it is unexpectedly possible to use the antibodies which are directed against the plasma membrane protein CDCP1 to selectively characterize and isolate haematopoietic stem cells and mesenchymal and neuronal stem cells and progenitor cells.
[0032] When these novel antibodies were used to identify haematopoietic stem cells, it was found that the antibodies exhibited a selectivity which was superior to that of antibodies which are directed against CD34 and which is similar to that of the antibody which is directed against CD133.
[0033] For this reason, the novel antibodies, or fragments thereof, provide advantageous alternatives to the CD34 antibody when identifying or isolating haematopoietic stem cells.
[0034] Such monoclonal antibodies can be prepared using conventional methods (see Kohler and Milstein, “Continuous cultures of fused cells secreting antibody of predefined specifity”, Nature 256:495-497, (1975)). According to this method, an animal is immunized with an antigen, the antibody-producing cells are isolated from the animal and these antibody-producing cells are fused with an immortal cell line. The resulting hybridoma cell lines are screened to determine whether they are able to produce an antibody against the antigen which was used for the immunization.
[0035] According to an object of the invention, the antibodies according to the invention also now make it possible to prepare further antibodies which bind to the same antigen. Using the antibodies according to the invention, it is possible to employ well known methods to isolate the corresponding antigen structures and to develop further monoclonal antibodies against the same antigen structures, with the known methods being employed in this case as well.
[0036] One object of the invention furthermore relates to hybridoma cell lines which are able to produce and release this type of antibody, in particular the hybridoma cell lines CUB1, CUB2, CUB3 and CUB4.
[0037] In providing the novel antibodies, the inventors have, for the first time, made available monoclonal antibodies, as well as hybridoma cell lines which produce and release these antibodies, which make it possible to selectively detect cell populations which are expressing the CDCP1 antigen. The antibodies therefore constitute a means, which is thus far unique and has many uses, for the physician and research worker to detect these types of cells, on the one hand, and, on the other hand, to manipulate these cells, where appropriate, either using the antibodies themselves or using reagents which are coupled to them.
[0038] Another object of the invention furthermore relates to a method for isolating and/or identifying at least one cell population which is selected from the group consisting of haematopoietic stem cells, neuronal stem cells, neuronal progenitor cells, mesenchymal stem cells and mesenchymal progenitor cells using an antibody, or a fragment thereof, with the antibody, or the fragment thereof, binding to the same antigen as does an antibody which is produced by the hybridoma cell lines CUB 1, CUB2, CUB3 and CUB4, which were deposited in the DSMZ, in accordance with the Budapest treaty, under the numbers DSM ACC2569, DSM ACC2566 and DSM ACC2565, on Aug. 14, 2002, and DSM ACC2551, on Jul. 12, 2002.
[0039] In another embodiment and according to yet another object, the method according to the invention uses an antibody, or a fragment of an antibody, which is produced by the hybridoma cell lines CUB1, CUB2, CUB3 and CUB4.
[0040] Another object of the invention furthermore relates to a method for isolating and/or identifying at least one cell population, which is selected from the group consisting of haematopoietic stem cells, neuronal stem cells, neuronal progenitor cells, mesenchymal stem cells and mesenchymal progenitor cells, using an antibody, with the method comprising the following steps:
(a) bringing a sample of a cell suspension which contains at least one cell population into contact with the novel monoclonal antibody, or a fragment thereof, and (b) isolating and/or identifying the cells which are linked to the novel monoclonal antibody or to the fragment thereof.
[0043] Yet another object of the invention furthermore relates to a method for isolating and/or identifying at least one cell population, which is selected from the group consisting of haematopoietic stem cells, neuronal stem cells, neuronal progenitor cells, mesenchymal stem cells and mesenchymal progenitor cells, using an antibody, with the method comprising the following steps:
(a) bringing a sample of cell suspension which contains at least one cell population into contact with the novel monoclonal antibody, or a fragment thereof, and with at least one additional antibody which binds to at least one of the cell populations, and (b) isolating and/or identifying the cells which are linked to the monoclonal antibody, or to the fragment thereof, and to the additional antibody.
[0046] In this connection, the bringing into contact of a cell mixture with the antibody can according to a further object be effected in solution as is the case, for example, when using a flow cytometer (=fluorescence-activated cell sorter (FACS)).
[0047] Described in a general manner, cells are loaded, in flow cytometry, with antibodies which are on the one hand specific for a surface marker and on the other hand coupled to a fluorescent dye. The cells which are marker-positive fluoresce while the negative cells remain dark. It is therefore an object and possible to ascertain what proportion of a cell population is marker-positive. At the same time, a flow cytometer makes it possible to record the size and granularity of cells.
[0048] It is also an object and possible to use a method for magnetic cell separation (MACS, magnetic cell sorting). In this method, the cells are labelled with magnetic beads, with it being possible for these beads to be coupled to the antibodies, for example.
[0049] In addition, the bringing into contact can according to a further object also be carried out by immobilizing the monoclonal antibody on a support as is the case, for example, in column chromatography.
[0050] The cell suspension can according to one object be any solution containing bone marrow cells, blood cells or tissue cells.
[0051] After the cell suspension has been mixed with the antibody, the cells which are expressing the CDCP 1 antigen bind the antibody, after which these cells can, in contrast to the cells which have not bound any antibody, be identified and/or isolated using the described methods.
[0052] In the method which was disclosed last, use is furthermore made of an additional antibody which also recognizes the cells. This antibody can according to one object, for example, be an antibody which is directed against the CD90 marker, in the case of neuronal progenitor cells, and be an anti-CD34 antibody, for example, in the case of haematopoietic cells. Using an additional antibody makes it possible to isolate/identify specific subpopulations, which consequently bind both the novel antibody and additional antibodies, in particular antibodies which are already known. This method can according to one object be used, for example, to characterize the cells more precisely with regard to their surface markers.
[0053] The cell populations which have been isolated by the methods can according to a further object then be used to repopulate, by means of transplantation, the bone marrow in immunosuppressed or immunodefective patients.
[0054] One object of the invention furthermore relates to the use of the novel antibodies, or fragments thereof, for isolating and/or identifying at least one cell population which is selected from the group consisting of haematopoietic stem cells, neuronal stem cells, neuronal progenitor cells, mesenchymal stem cells and mesenchymal progenitor cells.
[0055] According to yet another object, particular preference is given to using the novel antibodies, or fragments thereof, in connection with analysing patient samples, in particular tissue biopsies, bone marrow biopsies and/or blood samples, and in particular, when classifying leukaemias.
[0056] In the present instance, it has been possible to use the novel antibodies to detect expression of the corresponding antigen on leukaemia blasts as, for example, in the case of acute lymphatic leukaemia (ALL), acute myeloid leukaemia (AML) and chronic myeloid leukaemia (CML).
[0057] According to another object, the invention furthermore relates to the use of the CDCP-1 protein and/or of the nucleic acid which encodes the CDCP-1 protein for preparing antibodies, or fragments thereof, for isolating and/or identifying haematopoietic stem cells.
[0058] According to yet another object, the invention furthermore relates to a pharmaceutical composition which comprises at least one novel antibody, or fragments thereof.
[0059] In addition to the antibody, which represents the active compound in the composition, this composition can according to another object also comprise suitable buffers, diluents or additives. Suitable buffers include, for example, Tris-HCl, glycine and phosphate, while suitable diluents include, for example, aqueous solutions of NaCl, lactose or mannitol. Suitable additives include, for example, detergents, solvents, antioxidants and preservatives. A review of the substances which can be used for compositions of this nature is given, for example, in: A. Kibbe, “Handbook of Pharmaceutical Excipients”, 3rd Ed., 2000, American Pharmaceutical Association and Pharmaceutical Press.
[0060] According to a further object, the invention furthermore relates to a kit which comprises at least one novel antibody, or fragments thereof.
[0061] Further advantages ensue from the enclosed figures and the description.
[0062] It will be understood that the features which are mentioned above, and those which are still to be explained below, can be used not only in the combination which is in each case specified but also on their own or with other combinations without departing from the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] Embodiments are depicted in the enclosed drawings and are explained in more detail in the description, in which:
[0064] FIG. 1 a shows the reactivity of the antibodies according to the invention with wild-type cells;
[0065] FIG. 1 b shows the reactivity of the antibodies according to the invention with transfectants;
[0066] FIG. 2 a shows the coexpression of CD34 and CDCP1 on bone marrow cell populations (cells labelled with CD34-FITC) and CDCP1-PE (CUB 1));
[0067] FIG. 2 b shows bone marrow cells in a CD34 versus CD38 plot and gating on the stem cell population (bone marrow cell populations labelled with CD38-FITC, CDCP1-PE, CD34-PerCP and CD133-APC);
[0068] FIG. 2 c shows the coexpression of CDCP1 and CD133 on CD34 + /CD38 − bone marrow stem cells;
[0069] FIG. 3 shows the expression of CDCP1 on mesenchymal stem cells;
[0070] FIG. 4 a shows the expression of CDCP1 on neuronal stem cells; and
[0071] FIG. 4 b shows the coexpression of CDCP1 and CD90 on neuronal stem cells.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Preparing Transfectants
[0072] Starting with the cloning vector pBluescript II SK(+), into which the coding region of human CDCP1 had been cloned (obtained from Boehringer Ingelheim/Vienna), the coding sequence was subcloned into a pRK vector (PharMingen, San Diego, USA) and, at the same time, a five-fold myc-epitope (13 amino acids of the c-myc protein) was attached C-terminally. The pRK-CDCP1-myc5 DNA was cotransfected, together with a puromycin resistance plasmid (pSVpacAp: de la Luna et al., “Efficient transformation of mammalian cells with constructs containing a puromycin-resistance marker”, Gene, 62(1): 121-126, 1988) into NIH-3T3 mouse cells using the CaCl.sub.2 method.
[0073] After individual puromycin-resistant cells had been cloned, expression of the CDCDP1-myc5 protein in the transfected cells was detected by Western blotting using an anti-myc antiserum. The clone NIH-3T3/huCDCP1 was subsequently selected.
Immunization
[0074] Two Balb/c mice were immunized four times intraperitoneally with approx. 5-10×10 6 NIH-3T3/huCDCP1 cells using a standard protocol. Three to four days after the last immunization, the spleen was removed and the spleen cells were fused with SP2/0 myeloma cells using a standard protocol. The cell culture supernatants from growing, HAT-resistant hybridoma cells were tested by FACS analysis both on the transfectants and on the wild-type cell lines (NIH-3T3).
[0075] Supernatants which reacted selectively with the transfectants but not with the wild-type cell line NIH-3T3 were judged to be specific for CDCP1. The corresponding hybridoma cells were cloned (limiting dilution) and positive clones were selected. Four clones (CUB1, CUB2, CUB3 and CUB4) which reacted selectively with NIH-3T3/huCDCP1 cells were obtained (isotypes: one IgG2b [CUB1] and three IgG2a [CUB2-4]).
[0076] The histograms in FIG. 1 a show that the four antibodies did not react with the wild-type cell. FIG. 1 b shows histograms in which the reactivity of the four antibodies CUB1, CUB2, CUB3 and CUB4 with the transfectants is clearly depicted by the second, dark peak which is present in each case.
Investigating the Reactivity of the Antibodies on Peripheral Blood Cells
[0077] The reactivity of the antibodies on peripheral blood cells was tested first of all. The results of these investigations are shown in Table 1 below.
[0078] It was found that CD3 + T lymphocytes, CD20 + B lymphocytes, CD56 + NK cells, CD14 + monocytes, neutrophilic granulocytes, Siglec-8 + eosinophilic granulocytes, CD235a + erythrocytes and CD61 + platelets were negative for CDCP1.
[0000]
TABLE 1
Reactivity of the CDCP1-specific antibody
CUB1 on peripheral blood cells
Cell Type
Reactivity
T lymphocytes (CD3 + )
−
B lymphocytes (CD20 + )
−
NK Cells (CD56 + )
−
Monocytes (CD14 + )
−
Neutrophilic granulocytes (CD15 + )
−
Eosinophilic granulocytes (Siglec-8 + )
−
Basophilic granulocytes (CD203c + )
−
Erythrocytes (CD235a + )
−
Platelets (CD61 + )
−
[0079] The results of the reactivity of the antibodies on various cell lines, which are listed horizontally, are shown in Table 2 below. The four antibodies tested, i.e. CUB1 to CUB4, are listed vertically.
Description of the Cell Lines:
[0080] K-562: erythroleukaemia; WERI-RB-1: retinoblastoma; BV-173: Pro-B cell leukaemia; HEL: erythroleukaemia; HL-60: promyelocytic leukaemia; KU-812: basophilic leukaemia; HepG2: hepatocellular carcinoma; MOLT-4: T-lymphocytic leukaemia.
[0000]
TABLE 2
Reactivity of the CDCP1-specific antibodies CUB1, CUB2, CUB3 and CUB4 on various cell lines
CD34-
CD133-
WERI-
Tf*
Tf*
K-562
RB-1
BV-173
HEL
HL-60
KU-812
Hep-G2
MOLT-4
CUB1
−
−
+
−
−
−
−
−
−
−
CUB2
−
−
+
−
−
−
−
−
−
−
CUB3
−
−
+
−
−
−
−
−
−
−
CUB4
−
−
+
−
−
−
−
−
−
−
*Tf = Transfectant
[0081] It was found that all the cell lines tested were negative for CDCP1 apart from K-562. Scherl-Mostageer et al. have already shown that K-562, an erythroleukaemic cell line, expresses CDCP1 mRNA.
[0082] Further investigations were carried out into the correlated expression of CDCP1 and the other stem-cell markers CD34 and CD133 on various subsets of leukaemia blasts. The results obtained in these investigations are summarized in Table 3 below. The expression patterns were obtained by means of standard immunofluorescence labellings, using the antibodies, and then carrying out FACS analysis.
[0083] The analysis showed that CDCP1 is an independent marker in relation to the other stem cell markers since its expression is not necessarily correlated with that of the other markers. Frequent coexpression of all three stem cell markers can be seen, in particular, in the case of the myeloid leukaemias (AML and CML).
[0000]
TABLE 3
Expression of CDCP1 on leukaemia blasts
ALL
CML
(B-ALL, Pro-B-ALL,
AM
(Blast
Pre-B-ALL, C-ALL
(M1-M5)
crisis)
CD34 + DC133 + CDCP1 +
2/20
4/11
4/10
CD34 + DC133 + CDCP1 −
5/20
2/11
0/10
CD34 + DC133 − CDCP1 +
1/20
1/11
2/10
CD34 + DC133 − CDCP1 −
7/20
0/11
2/10
CD34 − DC133 + CDCP1 +
0/20
2/11
0/10
CD34 − DC133 + CDCP1 −
0/20
0/11
0/10
CD34 − DC133 − CDCP1 +
1/20
0/11
1/10
CD34 − DC133 − CDCP1 −
4/20
2/11
1/10
[0084] In the table, ALL denotes acute lymphatic leukaemia while AML denotes acute myeloid leukaemia and CML denotes chronic myeloid leukaemia (the additional designations are classification and characterization designations which are customarily used for the acute leukaemias).
[0085] The novel antibodies can consequently be used, for example, in routine diagnoses in connection with leukaemias.
Investigating the Reactivity of the Antibodies on Bone Marrow Cells
[0086] The reactivity of the antibodies with bone marrow cell populations was subsequently investigated. It turned out that CDCP1 is exclusively expressed on CD34 + stem cells and not on other populations (see FIG. 2 a ). The FACS-sorted CDCP1 + fraction consisted almost entirely of immature blasts and immature colonies: CFU-GM (colony-forming unit granulocyte macrophage), BFU-E (burst-forming unit erythroid) CFU-GEMM (colony-forming unit granulocyte-erythroid-macrophage-megakaryocyte).
[0087] FIGS. 2 b and 2 c show the results of a four-colour analysis of bone marrow cells.
[0088] In order to carry out the four-colour analysis, the cells were labelled with the following antibody conjugates: CUB1-PE (phycoerythrin), CD133-APC (allophycocyanin), CD38-FITC (fluorescein isothiocyanate) and CD34-PerCP (peridin chlorophyll A protein).
[0089] In the plot in FIG. 2 b , CD34 is plotted against CD38. Stem cells are found in the rare CD34 + /CD38 − fraction (Terstappen and Huang “Analysis of bone marrow stem cell”, Blood Cells 20(1): 45-61, 1994). In the plot in FIG. 2 b , this population is shown in the “R2-region”.
[0090] In the plot in FIG. 2 c , CDCP1 is plotted against CD133. This plot depicts the cells which can be seen in the “R2” region in the plot in FIG. 2 b . FIG. 2 c shows that essentially all the CD34 + /CD38 − stem cells coexpress CDCP1 and CD133.
[0091] In other experiments, the inventors were able to demonstrate that, 6 weeks after CDCP1-positive cells had been transplanted into NOD/SCID mice, human CD45 + cells had formed in the bone marrow of the mice. (CD45 + is a marker for haematopoietic cells). This consequently proves that the cells which are isolated using the novel antibodies are able to carry out haematopoiesis.
Investigating the Reactivity of the Antibodies on Neuronal and Mesenchymal Stem Cells
[0092] In other experiments, the reactivity of the antibodies towards neuronal and mesenchymal stem cells was investigated.
[0093] Commercially available foetal neuronal progenitor cells (in the following NPC) and mesenchymal stem cells, obtained from Cell-Systems, St. Katharinen, Germany, were used for this purpose.
[0094] In FIG. 3 , the second dark peak in the histogram shows that the CUB2 antibody reacts with mesenchymal stem cells. The histogram in FIG. 4 a shows the reactivity with NPC, with the antibody CUB2 in this case being labelled with PE (phycoerythrin).
[0095] In order to carry out the coexpression analysis, the cells were labelled with the following antibody conjugates: CUB1+alqG2bPE (phycoerythrin), and CD90-APC (allophycocyanin). CD90 is known to be expressed on NPC (see, for example Vogel et al., “Heterogeneity among human bone marrow-derived mesenchymal stem cells and neural progenitor cells”, Haematologica 88: 126-133, (2003)).
[0096] In the plot in FIG. 4 b , CDCP1 is plotted against CD90. It can be seen that the majority of the NPC cells expressed CDCP1 (in addition to CD90 as the “confirmation marker”).
[0097] In summary, therefore, these data show that CDCP1 is a novel marker for haematopoietic stem cells and for mesenchymal or neuronal stem cells/progenitor cells. It is possible to use the antibody according to the invention which is directed against this marker to select CDCP1-expressing stem cells in a simple manner and then, for example, transplant them for the purpose of repopulating. The antibody according to the invention is consequently of very great importance for selecting haematopoietic or mesenchymal and/or neuronal stem cells. In addition, it constitutes an outstanding alternative to the CD133 and CD34 markers which are commonly used for selecting stem cells.
[0098] It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of any appended claims. All figures, tables, and appendices, as well as publications, patents, and patent applications, cited herein are hereby incorporated by reference in their entirety for all purposes. | Monoclonal antibodies, or fragments thereof, are used for isolating and/or identifying at least one cell population. The cell population can include any of the following types of cells: haematopoietic stem cells, neuronal stem cells, neuronal progenitor cells, mesenchymal stem cells and mesenchymal progenitor cells. The antibodies, or fragments thereof, bind to an antigen which is the same as that bound by an antibody which is produced by the hybridoma cell lines CUB1, CUB2, CUB3 and CUB4, which were deposited in the DSMZ under the numbers DSM ACC2569, DSM ACC2566 and DSM ACC2565, on Aug. 14, 2002, and DSM ACC2551, on Jul. 12, 2002. | 2 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims priority to Provisional Application No. 60/272,044 filed Mar. 1, 2001, which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates generally to filtration. More specifically, the invention relates to the use of porous inorganic particles in a filtration apparatus, such as a packed bed, where the apparatus includes porous, inorganic particles. The invention also contemplates the use of the porous, inorganic particles, particularly in a packed bed, which are capable of filtering one or more substances from a fluid, such as air.
BACKGROUND OF THE INVENTION
[0003] Filtration media can be used to prevent undesirable vapors, particulate, or suspended droplets in a gas stream from escaping into the atmosphere. For example, whenever an oleo material or substances (e.g. grease, oil or fat) are heated, some will vaporize or form droplets. There is a desire to prevent such vaporized or droplet material from escaping into the air, unfiltered. Presently employed filtering media can include an aggregate of fibrous material, such as organic fiber mat or inorganic fiberglass, that extend over the traveling path of a vapor or liquid, such that the fibrous material catches the oleo vapors or droplets as they pass through the interstices of the filtering material. Although, initially, such filtering mechanisms may be capable of efficiently removing the oleo vapors or droplets from the air stream, the oleo vapors or droplets gather in the interstices of the filtering material in increasing quantities as the filtration process progresses, resisting the flow.
[0004] The flow rate of air through the filter immediately begins to decrease as the oleo material begins to collect on the filter media. This build-up of undesirable substances can substantially or completely block the flow of air and its load of material to be filtered through the filter, requiring frequent replacement of the filter. This replacement process typically requires a shut down of the mechanism that produces the vapor. Often times, the filter, upon having the undesirable substance collected thereon is disposed of without further use.
[0005] U.S. Pat. No. 5,776,354, issued to van der Meer et al., discloses a method for separating a dispersed liquid phase (i.e. an oil film) from a gas, using a filter bed of a particulate, porous polymer material whose size is on the order of 0.1 to 10 mm. Although van der Meer et al. teach that the dispersed liquid phase can fill into the pores of the particulate material, the particulate material is a polymer, thereby restricting the available methods for subsequently separating the liquid phase from the particulate material. In fact, van der Meer et al. only teach centrifugal force (i.e. a centrifuge) for separating the oil from particulate material. Thus, there remains need for filtration media that not only (1) ameliorate the problem of restricted airflow through the filter, but (2) also can undergo harsher filtrate-separation processes, yet subsequently retain its desired properties for repeated use.
SUMMARY OF THE INVENTION
[0006] Accordingly, it is an object of the invention to provide renewable, porous filtering media to separate a filtrate substance (in the form of vapor, aerosol, and/or liquid) from a fluid such as a gas or liquid, such that the flow of the fluid through the porous filtering media will not be substantially impeded prior to the time said porous media are filled with said vapor, aerosol, and/or liquid.
[0007] It is a further object of the invention to provide filtering media that can retain their filtering properties subsequent to undergoing a harsh filtrate-separation protocol.
[0008] It is another object of the invention to provide filtering media that permit a continuous, uninterrupted fluid flow. This provides a uniform filtration mode until the media are saturated.
[0009] The invention provides for a filtration media that includes porous particles (whose composition is inorganic) arranged to separate one or more filtrate substances from a fluid or fluids wherein the porous particles collect and retain within themselves the filtrate substance(s). In a preferred embodiment, the porous particles are arranged in a packed bed. In a particularly preferred embodiment, the particles relinquish substantially all of the substances during a separation step and the particles maintain the ability to collect the substance(s) repeatedly.
[0010] The invention further contemplates an apparatus for separating one or more substances from a moving fluid which includes a housing for said packed bed of porous particles located in a duct through which said moving fluid with the filtrate substance(s) is passing. Various designs may be used so as to cycle the moving fluid through a plurality of such housings and beds without having to shut down the system. Further, the beds may be treated in said cycles so as to refresh the particles for their intended use.
[0011] In a preferred embodiment, the invention describes a method for substantially separating one or more oleo substance(s) from a fluid, particularly a gas such as air, which comprises the steps of placing the inorganic, porous particles, which may be spherical or pellet-like in shape or have other shapes, into contact with the fluid, which moves relative to the particles; and allowing the oleo substance(s) to collect within at least a portion of the inorganic particles as the vapor composition passes at least substantially through the inorganic porous particles. In one sense, the inorganic porous particles are arranged to form a network, such as a packed bed, suitable for filtering the oleo substances from the moving fluid.
[0012] Methods according to the invention further comprise substantially separating the filtrate substance from the inorganic, porous particles and repeating the steps of placing the inorganic, porous particles into contact with the fluid and allowing the filtrate substance to collect within at least a portion of the inorganic particles.
[0013] In another embodiment, the filtrate substance includes hydrophilic vapors or suspended droplets. This invention provides a method for substantially separating the hydrophilic vapors or suspended droplets by placing the inorganic, porous particles, preferably in the form of a packed bed, into contact with a fluid flow which contains the filtrate substance. This allows the hydrophilic substance to collect within at least a portion of the inorganic particles due to the hydrophilic nature of internal and external surfaces of the porous particles. Further, the internal surfaces of the pores of said particles may be treated with reactive substances that may be biocidal, catalytic, or chemically reactive with the contents of said vapors or suspended droplets.
[0014] These and other objects will be apparent to a skilled worker, as shown by the embodiments described and contemplated herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 shows a filtration apparatus comprising a packed bed of inorganic particles and a ventilation system according to one embodiment of the present invention.
[0016] FIGS. 2 A- 2 D show a filtration apparatus comprising a packed bed of inorganic particles and a ventilation system according to another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The present invention provides, inter alia, inorganic, porous particles that are capable of trapping filtrate substances from a fluid. As used herein, “filtrate substance” is defined as the substance (e.g., gas, vapor, liquid, suspended droplets, etc.) that is intended to be removed from the fluid. The fluid containing the filtrate substance can be either a gas or liquid.
[0018] The particles are suitable for separating one or more of the filtrate substances from a fluid flow, e.g. a gas, which contains such filtrate substances. To this end, in a preferred embodiment, the inorganic particles can be arranged into a packed bed-like formation, or network, such that the network comprises (1) particles interacting with each other and (2) interstices defined between the exterior surface area of the interacting particles. Thus, in one embodiment, a fluid containing the filtrate substances can flow through (or substantially through) the packed bed, leaving behind one or more filtrate substances that collect within at least a portion of the particles. Although the embodiments described herein indicate that the fluid moves relative to the filter media, other embodiments such as those in which the filter media move are also contemplated.
[0019] A particularly preferred combination is one in which the filtrate substance is a grease, fat or oil (collectively referred to as an “oleo substance”) and the fluid is air.
[0020] As indicated, the inorganic particles, or media, that comprise the core of the filtration apparatus described more fully below, are porous, having an external surface area and a network of open channels that define internal surfaces. In a preferred embodiment, the inorganic particles can have any suitable shape, e.g., spherical, pellet-like, etc. The particles may have any suitable size depending on end use, and may range in size from about 0.25-4 mm, preferably 0.33-3.5 mm, and more preferably 0.5-3 mm. For non-spherical particles, the size measurement is taken at the largest dimension. In other suitable embodiments, the particles can have a size that ranges from greater than 4 mm, preferably from greater than 4 to 50 or even 100 mm. In some embodiments, the pores preferably have a mean size between about 0.01 to 100 microns, preferably 0.1 to 10 microns. The media can also have other shapes such as porous fibers and other formed shapes such as rings, saddles, etc.
[0021] The inorganic particles can have porosity in the range of 15-70%, preferably 30-70%. These internal surfaces accordingly are exposed to the filtrate substance (e.g. oleo) substance(s) passing through the network of particles. That is, the pores of the inorganic particle or particles are large enough such that the filtrate substance can fit inside of, or otherwise pass through, one or more pores. Accordingly, in one embodiment, the surfaces of the pores can comprise an oleophilic substance and, therefore, attract an oleo substance. In this sense, a relatively powerful force, such as surface tension, can draw the filtrate substance within the openings of the pores. Hence, the filtrate substance, such as an oleo substance, can collect within the pores in lieu of and/or in addition to adhering to the exterior surface area of the particles. In other embodiments, described more fully below, the interior and/or exterior of the particle can have a catalyst and/or reactant coated thereon.
[0022] The open channels, e.g., pores, of the inorganic particle in a preferred embodiment can exist in a reticulated, open, sintered structure. In this sense, a reticulated structure is a structure made up of a network of interconnected struts that form a strong, interconnected continuum of pores. A method for preparing a sinterable structure is disclosed in co-pending application Ser. No. 09/286,919, entitled “Sinterable Structures and Method”, which is hereby incorporated herein by reference in its entirety. More specifically, this co-pending application describes processes for producing a porous, sintered structure, comprising (1) preparing a viscous mixture comprising a sinterable powder of ceramic or metal dispersed in a sol of a polymer in a primary solvent; (2) replacing the primary solvent with a secondary liquid in which the polymer is insoluble, thereby producing a gel which comprises an open polymeric network that has the sinterable powder arranged therein; (3) removing the secondary liquid from the gel; and (4) sintering the sinterable powder to form the open, porous structure.
[0023] The particles of the invention may be comprised of any inorganic material that confers the requisite characteristics upon the particles (e.g. capable of containing pores, at least substantially maintains porosity and ability to collect a filtrate substance inside the pores of the particles after a filtrate-separation operation describe more fully below, preferably a harsh filtrate separation). An illustrative list of suitable materials of which the particles can be comprised include: a ceramic material such as transition metal oxides, zircon, zirconia, titania, silica, alumina, alumina-silica (clay) or a variable blend thereof. An especially preferred particle is a clay such as kaolin, bentonite or montmorillonite. Porous iron made by 09/286/919 also will absorb oleo substances.
[0024] The individual porous particles, once formed, can be assembled into a network suitable for filtering the one or more substances from the fluid composition. The porous particles can be arranged as a packed bed in a vertical plane, a horizontal plane or both. Preferably, each porous particle interacts with at least one other particle, yet forms interstices between the particles, such that a fluid can pass through the interstices. In one embodiment, the porous particles form a bed that defines a constant surface area. The particles preferably extend along at least the horizontal or vertical cross section of the bed or casing to define a continuous section of alternating particles and interstices. An example is a bed of porous particles packed within a perforated or porous wall container. Alternatively, two or more particles of the bed may be physically attached, such as by heating the particles to sufficient temperature to sinter the particles together, while maintaining space between the particles sufficient to allow the passage of a vapor or liquid there through.
[0025] Once formed, the inorganic porous particles, which can be in the form of the network described above, can be placed into contact with a fluid composition containing the filtrate substance, preferably an oleo substance. The particles may be positioned in association with a fluid such that the fluid passes through or at least substantially through the interstices and/or pores of inorganic particles, leaving behind at least a portion, but preferably the majority, of the filtrate substance suspended in the fluid. In this sense, the filtrate substance collects on and within the inorganic particles.
[0026] As the fluid passes through the packed bed of inorganic particles, there is resistance to the flow, resulting in a drop in pressure on the exit side of the bed. In a preferred embodiment, this drop in pressure remains substantially constant, which means that the filtrate substance collect within the pores to a greater extent than in the interstices between the exterior surface area of the particles. At any time, the inorganic particles can be removed from the flow of fluid, in order to separate the filtrate substance from inorganic particles. In some embodiments, the particles may be regenerated, in situ. However, it is preferred that the particles are removed from the fluid flow whenever the filtrate substance at least substantially has filled the pores and/or may have begun to fill the interstices between the inorganic particles. This conveniently can be determined by detecting a measurable decrease in the pressure of the fluid through the filter media.
[0027] The inorganic particles may be removed from the fluid flow in any number of ways, from simple replacement to automated systems. For instance, the particles can be a magnetic material and an external magnetic force may be applied to draw the particles away from the fluid flow, such as vapor flow. Alternatively, gravitational forces could be employed to move the particles downwardly, for example, beneath the fluid flow. In addition, a vacuum force could be used to pull the particles out of the stream of flowing fluid. Further still, the invention contemplates the employment of a see-saw apparatus that has the filter media on both ends of a pivoting elongated member, where the media can be raised and lowered from a filtering position to a regeneration position. In a similar manner, a rotating wheel or disk containing the filtering media can be rotated from a position of filtering to a position of separation and/or regeneration.
[0028] The separation step preferably is carried out such that, upon removing the filtrate substance from the inorganic materials, the inorganic particles again can be used to filter a substance from a moving stream of fluid as before. Filtrate-separation operations may be selected from the group consisting of heat treatment at a temperature sufficient to volatilize the filtrate substances and burn off any remaining residue (up to 1000° C.), solvent extraction, detergent wash, and centrifugal removal, and combinations of these separations. Particularly preferred separation operations are harsh filtrate separations such as heat treatment and solvent extraction. Suitable solvents for removing the filtrate substance may include organic solvents or preferably known biodegradable solvents. A detergent suitable for the detergent washing step can be a commercial one, e.g., Dawn. Other known suitable detergents can also be used. A significant advantage of the present invention is that the inorganic porous particles are capable of withstanding harsh separation treatments where necessary as described above. After the filtrate substance is removed from the inorganic particles, the filtrate substance may be discarded and the particles can be re-positioned within the stream of the flowing fluid. The filtrate collection and separation process can be repeated multiple times.
[0029] In the catalytic embodiment, described below, the separation step can be facilitated by incorporation of the catalyst. Because the internal pores are completely available in the sintered structure of 09/285,919, a catalyst coated on the pore walls substantially increases the catalyst availability to reactants, e.g. hydrocarbons and oxygen.
[0030] In another embodiment, for instance, porous particles of the invention could contain hydrophilic surfaces within the porous area. The invention, accordingly, contemplates the removal of malodorous or toxic vapors from air. Current filtration apparatus in air conditioning systems, for example, might not effectively remove harmful vapors or droplets, such as those carrying spores or bacteria, e.g. the so-called “Legionnaire's Disease.” A porous filter, as described herein, having surfaces adapted to be hydrophilic, could capture noxious vapors or droplets. Thereafter, the trapped vapors or droplets could be heated, thereby destroying any bacteria, spores, virus or other harmful material associated with the vapors or droplets. In a preferred embodiment, the surfaces of the pores, such as struts, can be coated or impregnated with a biocidal agent, such as well known silver containing biocides, e.g., silver iodide and/or antibiotics, e.g., tetracycline. Another possible coating could include diazeniumdiolate in a siloxane polymer. Of course, the exterior surface of the porous particles can also be coated or impregnated with a biocidal agent.
[0031] In still another embodiment, the filtrate substance is treated and subsequently removed by reacting the filtrate substance using a catalyst that is within the pores and on the exterior surface of the particles. Optionally, the filtrate substance can be reacted with another component that may be coated on the particle, in the fluid, or even the fluid itself. In one embodiment, ethane can be reacted in and subsequently removed from a gas stream by converting the ethane to ethylene in the presence of hydrogen using a noble metal catalyst on the surface and within the pores of the particles. This catalytic reaction can occur by passing the fluid over or through a bed of the inorganic particles, or within a fluidized bed of the same particles.
[0032] The invention also provides an apparatus for substantially separating one or more filtrate substances from a moving fluid stream. This apparatus may comprise a packed bed or network of inorganic particles, as described, in combination with a series of vents or ducts that channel the fluid stream towards the network of inorganic particles. The system also may comprise a series of vents or ducts that channel the fluid to another location, upon passing through the network of inorganic particles. For instance, the fluid may exit into the atmosphere upon passing through the inorganic particles. Alternatively, the fluid first may pass through a catalyst bed for further treatment of the fluid.
[0033] The system can be constructed such that the source creating the fluid flow does not need to be turned off in order to perform the filtrate substance removing step. To this end, the system may comprise multiple series of ducts or vents that can be operated in tandem with each other. Accordingly, one series of ducts or vents may be opened, while the others are closed. The open series would act to direct the fluid, such as a vapor, to the inorganic particles and then away from the particles after passing there through. At the appropriate time, the inorganic particles, having the filtrate substance collected therein, can be cleaned by a filtrate-separation protocol, for example. Further, the inorganic particles may remain substantially at their present location or they may be moved to a different location (e.g. by magnetic, vacuum or gravitational force) before separating the filtrate substance(s) from the particles. At this stage, the open series of vents or ducts can be closed and the closed series then can be opened, as the filtering process continues.
[0034] One non-limiting example of a filtration apparatus contemplated by the invention is described in the schematic diagram of FIG. 1. With reference to FIG. 1, housing ( 1 ) holds the filtrate substance, e.g., an oleo substance. Upon being heated within the housing, the filtrate substance in a fluid (in this instance in a stream of flowing exhaust air) enters duct ( 2 ). The filtrate substance can then be selectively passed into duct ( 3 ) or ( 4 ), such as by a valve. The filtrate substance enters the filter media ( 5 ) or ( 6 ), that includes the network of inorganic particles. A pre-filter (not shown) may be positioned before the filter media.
[0035] The filtrate substance collects within interstices and pores of the particles (not shown), as the exhaust passes through the filter media. Thereafter, the exhaust passes into and through ducts ( 7 ) or ( 8 ) which lead to catalytic reactor ( 9 ). After passing through catalytic reactor ( 9 ), the exhaust can be vented into the atmosphere ( 10 ).
[0036] The filter media can be positioned adjacent to electric heater (not shown), that, when activated, can transfer heat to particles in the filter media. The heat will cause the filtrate substance, such as an oleo substance (not pictured) to separate from the particles that can be drained as needed. Generally, the heat-separation process occurs when the apparatus is shut down, or when the fluid flow directed into the other filter media.
[0037] Another embodiment is shown in connection with FIGS. 2 A- 2 D. With reference to FIG. 2A, housing ( 11 ) holds the filtrate substance, e.g., an oleo substance. Upon being heated within the housing, the filtrate substance enters duct ( 12 ). The filtrate substance then enters into filter media ( 16 ). FIG. 2D shows the cross section of filter media 16 taken along line I-I. In an embodiment shown in FIG. 2B, the filtrate substance can then be selectively passed into duct ( 14 ) or ( 15 ), such as by a valve ( 13 ), and then enter the filter media ( 16 ) or ( 17 ), that includes the network of inorganic particles. A pre-filter (not shown) may be positioned before the filter media.
[0038] Thereafter, in the embodiment of FIGS. 2A and 2B, the exhaust gas passes into fan ( 18 ) and is vented into the atmosphere through vent ( 19 ). In the embodiment shown in FIG. 2C, the exhaust first passes into catalytic reactor ( 20 ) before passing into fan ( 18 ).
[0039] Additional advantages, features and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices, shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
[0040] As used herein and in the following claims, articles such as “the,” “a” and “an” can connote the singular or plural. All documents referred to herein are specifically incorporated herein by reference in their entireties. | Inorganic, porous particles filter a substance or substances from a flow of fluid such as a gas. The particles can be arranged into a bed to filter a substance (filtrate substance) from a fluid. The filtrate substance can collect on or within the pores of the inorganic particles. Collection of the filtrate substance within the pores of the particles rather than within the interstices of the bed enhances the filtering capacity and does not impede the flow of fluid through the bed of particles. Furthermore, the inorganic particles are re-usable, in that they can be subjected to harsh filtrate-separation techniques, e.g., heat treatment, solvent extraction, detergent washing, and centrifugal separation, yet retain their desired properties. | 8 |
TECHNICAL FIELD
[0001] The present invention relates to a nanoporous metal modified with ceramic plating, and to a method for manufacturing the same. The present invention relates to the deposition modification of a nanoporous metal with ceramics. In particular, the present invention relates to a nanoporous metal/ceramic hybrid structure constituted by an at least binary system of a ceramic and a metal, such as a nanoporous metal/ceramic composite substance (including, for example, a thin film or foil) constituted at least by a porous metal skeleton and a ceramic deposit, and to a method for manufacturing the same; the composite typically having (1) a deposited ceramic layer (shell, coating, or packed layer) and a metal framework (interior or skeleton); the metal framework (nanoporous metal part) having an average pore size of roughly 80 nm or less, roughly 60 nm or less, in some cases roughly 50 nm or less, especially roughly 40 nm or less, or roughly 30 nm or less, or, for example, roughly 25 nm or less; and a super capacitor device constituted by an electrode using the nanoporous metal/ceramic composite material substance (for example, a thin film) having superior electrical properties and being desirable for various applications, such as power supply devices, power storage devices, rapid charging devices, and the like. A lithium battery using this electrode, such as a lithium ion secondary cell, has superior durability and charge/discharge cycle properties, and is desirable for various applications, such as batteries, power accumulation devices, portable electronic devices, automobile batteries, and the like.
BACKGROUND ART
[0002] Nanoporous metals have properties differing greatly from those of bulk metals, and show promise for a variety of noteworthy functions within the physical and chemical fields. For example, nanoporous metals exhibit large surface area and specific size effects, show promise of having superior electrical properties, physical and chemical properties, physical characteristics, and optical and electromagnetic effects, and are expected to be applied for use as catalysts and nanodevice nanostructures.
[0003] Supercapacitors (“SCs”), which combine the unique features of high power, high energy, and long life, have been the subject of attention as a halfway point between batteries and normal capacitors (see non-patent document 1: Winter, M.; Brodd, R. J., “What are batteries, fuel cells, and supercapacitors?” Chem. Rev. 104, 4245-4269 (2004); non-patent document 2: Simon, P.; Gogotsi, Y., “Materials for electrochemical capacitors” Nat. Mater. 7, 845-854 (2008); non-patent document 3: Arico, A. S.; Bruce, P.; Scrosati, B.; Tarascon, J. M.; Van Schalkwijk, W., “Nanostructured materials for advanced energy conversion and storage devices” Nat. Mater. 4, 366-377 (2005); non-patent document 4: Kotz, R.; Carlen, M., “Principles and applications of electrochemical capacitors”, Electrochim. Acta 45, 2483-2498 (2000); non-patent document 5: Burke, A., “Ultracapacitors: Why, how, and where is the technology?”, J. Power Sources 91, 37-50 (2000); non-patent document 6: Miller, J. R.; Simon P., “Electrochemical capacitors for energy management”, Science 321, 651-652 (2008); non-patent document 7: Pech, D.; Brunet, M.; Durou, H.; Huang, P. H.; Mochalin, V.; Gogotsi, Y.; Taberna, P. L.; Simon, P., “Ultrahigh-power micrometer-sized supercapacitors based on onion-like carbon”, Nature Nanotech, 5, DOI: 10.1038/NNANO.2010.162 (2010)).
[0004] SCs have large specific capacitances as the result of two charge mechanisms, namely, double-layer capacitance (non-patent documents 2-5; non-patent document 8: Huang, J. S.; Sumpter, B. G.; Meunier, V., “Theoretical model for nanoporous carbon supercapacitors”, Angew. Chem. Int. Ed. 47, 520-524 (2008)) and pseudocapacitance performing a charge-transfer reaction (non-patent documents 2-5; non-patent document 9: Conway, B. E.; Birss, V.; Wojtowicz, J., “The role and utilization of pseudocapacitance for energy storage by supercapacitors”, J. Power Sources 66, 1-14 (1997); non-patent document 10: Rudge, A.; Davey, J.; Raistrick, I.; Gottesfeld, S.; Ferraris, J. P., “Conducting polymers as active materials in electrochemical capacitors”, J. Power Source, 47, 89-107 (1994)), these two phenomena occurring via a non-Faradaic process and a Faradaic process, respectively, at or near the electrode/electrolyte interface (non-patent documents 2-10). These two mechanisms are dependent on the active electrode material substance used in the SC, and may act separately or together (non-patent documents 2-5 and 9-10; non-patent document 11: Toupin, M.; Brousse, T.; Belanger, D., “Charge storage mechanism of MnO 2 electrode used in aqueous electrochemical capacitor”, Chem. Mater. 16, 3184-3190 (2004); non-patent document 12: Pang, S. C.; Anderson, M. A.; Chapman, T. W., “Novel electrode materials for thin-film ultracapacitors: Comparison of electrochemical properties of sol-gel-derived and electrodeposited manganese dioxide”, J. Electrochem. Soc. 147, 444-450 (2000); non-patent document 13: Chmiola, J.; Yushin, G.; Gogotsi, Y.; Portet, C.; Simon, P.; Taberna, P. L., “Anomalous increase in carbon capacitance at pore sizes less than 1 nanometer”, Science 313, 1760-1763 (2006); non-patent document 14: Kaempgen, M.; Chan, C. K.; Ma, J.; Cui, Y.; Gruner, G., “Printable thin film supercapacitors using single-walled carbon nanotubes”, Nano Lett. 9, 1872-1876 (2009); non-patent document 15: Pushparaj, V. L.; Shaijumon, M. M.; Kumar, A.; Murugesan, S.; Ci, L.; Vajtai, R.; Linhardt, R. J.; Nalamasu, O.; Ajayan, P. M., “Flexible energy storage devices based on nanocomposite paper”, Proc. Natl. Acad. Sci. USA 104, 13574-13577 (2007)).
[0005] Of the numerous electrode material substances currently available, pseudocapacitative transition metal oxides, typically manganese dioxide (MnO 2 ), have been the object of intense scrutiny as one type of extremely promising electrode material substance due their high theoretical capacity, environmental friendliness, low costs, and natural abundance (non-patent document 11; non-patent document 16: Chang, J. K.; Tsai, W. T., “Material characterization and electrochemical performance of hydrous manganese oxide electrodes for use in electrochemical pseudocapacitors”, J. Electrochem. Soc. 150, A1333-A1338 (2003)).
[0006] Lithium-ion batteries (“LIBs”) are especially superior among energy storage media for their levels of power density per unit of volume or weight (non-patent document 25: J. M. Tarascon, M. Armand, Nature 2001, 414, 359; non-patent document 26: Y. Idota, T. Kubota, A. Matsufuji, Y. Maekawa, T. Miyasaka, Science 1997, 276, 1395; non-patent document 27: J. Hassoun, S. Panero, P. Simon, P. L. Taberna, B. Scrosati, Adv. Mater. 2007, 19, 1632; non-patent document 28: K. T. Nam, D. W. Kim, P. J. Yoo, C. Y. Chiang, N. Meethong, P. T. Hammond, Y. M. Chiang, A. M. Belcher, Science 2006, 312, 885). In order to achieve a greater reversible capacity (although such larger capacity might only be available momentarily), efforts have been made to discover a substance based on metallic tin as an anode electrode in lieu of a carbon-based compound (non-patent document 29: Lee, K. T.; Jung, Y. S.; Oh, S. M. J. Am. Chem. Soc. 2003, 125,5652-5653; non-patent document 30: Winter, M.; Besenhard, J. O.; Spahr, M. E.; Novak, P. Adv. Mater. 1998, 10, 725-763; non-patent document 31: Coward, G. R.; Leroux, F.; Power, W. P.; Ouvrard, G.; Dmowski, W.; Egami, T.; Nazar, L. F. Electrochem. Solid-State Lett. 1999, 2,367-370; non-patent document 32: Crosnier, O.; Brousse, T.; Devaux, X.; Fragnaud, P.; Schleich, D. M. J. Power Sources 2001, 94, 169-174) due to the high electron conductivity (non-patent document 33: Nazri, G.-A.; Pistoia G., “Lithium Batteries Science and Technology”, Kluwer: Boston, 2004) and high theoretical capacity (990 mAh/g, equivalent to Li 4.4 Sn) of metallic tin. These values are as much as three times those of graphite carbon (372 mAh/g, equivalent to LiC 6 ) (non-patent document 34: I. A. Courtney, J. R. Dahn, J. Electrochem. Soc. 1997, 144, 2045; non-patent document 35: M. Winter, J. O. Besenhard, Electrochim. Acta 1999, 45, 31).
[0007] However, the degradation in cycle properties that occurs when metallic tin is rendered into a shape suitable for use in LIBs is extremely problematic. This degradation arises primarily from pulverization, aggregation, and loss of electrical contact properties, leading to an effective change in volume (200% or greater) between charging and discharging (non-patent document 36: S. Grugeon, S. Laruelle, R. Herrera-Urbina, L. Dupont, P. Poizot, J. M. Tarascon, J. Electrochem. Soc. 2001, 148, A285; non-patent document 37: E. Shembel, R. Apostolova, V. Nagirny, I. Kirsanova, Ph. Grebenkin, P. Lytvyn, J. Solid St. Electrochem. 2005, 9, 96). The following three methods have primarily been offered as strategies for overcoming the problem of what is known as the pulverization of tin: reducing particle size; using a composite material substance; and selecting an optimized binder substance (non-patent document 26; non-patent document 38: N. Li, C. Martin, J. Electrochem. Soc. 2001, 148, A164; non-patent document 39: M. Wachtler, M. R. Wagner, M. Schmied, M. Winter, J. O. Besenhard, J. Electroanal. Chem. 2001, 12, 510; non-patent document 40: Y. Yu, L. Gu, C. Zhu, P. A. van Aken, J. Maier, J. Am. Chem. Soc., 2009, 131 15984; non-patent document 41: Y. Yu, L. Gu, C. Wang, A. Dhanabalan, P. A. van Aken, J. Maier, Angew. Chem. Int. Ed., 2009, 48, 6485). Two methods have been proposed to this end. The most common method for mitigating changes in volume or metal particle aggregation is to use an ultrapure metal-containing compound or active/inert composite alloy material substance (non-patent document 26; non-patent document 42: J. O. Besenhard, J. Yang, M. Winter, J. Power Sources 1997, 68, 87; non-patent document 43: J. Y. Lee, R. Zhang, Z. Liu, Electrochem. Solid-State Lett. 2000, 3, 167; non-patent document 44: J. Yang, M. Wachtler, M. Winter, J. O. Besenhard, Electrochem. Solid-State Lett. 1999, 2, 161). Another method is to construct a tin-based composite having a hollow structure, partially allowing for large changes in volume, and maintaining an electrical channel (non-patent document 29; non-patent document 45: H. G. Yang and H. C. Zeng, Angew. Chem., Int. Ed., 2004, 43, 5930; non-patent document 46: S. J. Han, B. C. Jang, T. Kim, S. M. Oh and T. Hyeon, Adv. Funct. Mater., 2005, 15, 1845). Electrodes having stable and high capacities of about 500 mAh/g have been reported very recently; these are manufactured by electrically depositing Sn—Ni on a nanoarchitectured copper substrate (non-patent document 47: J. Hassoun, S. Panero, P. Simon, P.-L. Taberna, B. Scrosati, Adv. Mater. 2007, 19, 1632).
PRIOR ART LITERATURE
[0008] Non-Patent Documents
[0009] Non-patent document 1: Winter, M.; Brodd, R. J. What are batteries, fuel cells, and supercapacitors Chem. Rev. 104, 4245-4269 (2004)
[0010] Non-patent document 2: Simon, P.; Gogotsi, Y. Materials for electrochemical capacitors. Nat. Mater. 7, 845-854 (2008)
[0011] Non-patent document 3: Arico, A. S.; Bruce, P.; Scrosati, B.; Tarascon, J. M.; Van Schalkwijk, W. Nanostructured materials for advanced energy conversion and storage devices. Nat. Mater. 4, 366-377 (2005)
[0012] Non-patent document 4: Kotz, R.; Carlen, M. Principles and applications of electrochemical capacitors. Electrochim. Acta 45, 2483-2498 (2000)
[0013] Non-patent document 5: Burke, A. Ultracapacitors: Why, how, and where is the technology. J. Power Sources 91, 37-50 (2000)
[0014] Non-patent document 6: Miller, J. R.; Simon P. Electrochemical capacitors for energy management. Science 321, 651-652 (2008)
[0015] Non-patent document 7: Pech, D.; Brunet, M.; Durou, H.; Huang, P. H.; Mochalin, V.; Gogotsi, Y.; Taberna, P. L.; Simon, P. Ultrahigh-power micrometer-sized supercapacitors based on onion-like carbon. Nature Nanotech. 5, DOI: 10.1038/NNANO.2010.162 (2010)
[0016] Non-patent document 8: Huang, J. S.; Sumpter, B. G.; Meunier, V. Theoretical model for nanoporous carbon supercapacitors. Angew. Chem. Int. Ed. 47, 520-524 (2008)
[0017] Non-patent document 9: Conway, B. E.; Birss, V.; Wojtowicz, J. The role and utilization of pseudocapacitance for energy storage by supercapacitors. J. Power Sources 66, 1-14 (1997)
[0018] Non-patent document 10: Rudge, A.; Davey, J.; Raistrick, I.; Gottesfeld, S.; Ferraris, J. P. Conducting polymers as active materials in electrochemical capacitors. J. Power Source, 47, 89-107 (1994)
[0019] Non-patent document 11: Toupin, M.; Brousse, T.; Belanger, D. Charge storage mechanism of MnO 2 electrode used in aqueous electrochemical capacitor. Chem. Mater. 16, 3184-3190 (2004)
[0020] Non-patent document 12: Pang, S. C.; Anderson, M. A.; Chapman, T. W. Novel electrode materials for thin-film ultracapacitors: Comparison of electrochemical properties of sol-gel-derived and electrodeposited manganese dioxide. J. Electrochem. Soc. 147, 444-450 (2000)
[0021] Non-patent document 13: Chmiola, J.; Yushin, G.; Gogotsi, Y.; Portet, C.; Simon, P.; Taberna, P. L. Anomalous increase in carbon capacitance at pore sizes less than 1 nanometer. Science 313, 1760-1763 (2006)
[0022] Non-patent document 14: Kaempgen, M.; Chan, C. K.; Ma, J.; Cui, Y.; Gruner, G. Printable thin film supercapacitors using single-walled carbon nanotubes. Nano Lett. 9, 1872-1876 (2009)
[0023] Non-patent document 15: Pushparaj, V. L.; Shaijumon, M. M.; Kumar, A.; Murugesan, S.; Ci, L.; Vajtai, R.; Linhardt, R. J.; Nalamasu, O.; Ajayan, P. M. Flexible energy storage devices based on nanocomposite paper. Proc. Natl. Acad. Sci. USA 104, 13574-13577 (2007)
[0024] Non-patent document 16: Chang, J. K.; Tsai, W. T. Material characterization and electrochemical performance of hydrous manganese oxide electrodes for use in electrochemical pseudocapacitors. J. Electrochem. Soc. 150, A1333-A1338 (2003)
[0025] Non-patent document 17: Desilvestro, J.; Haas, O. Metal oxide cathode materials for electrochemical energy storage: A review. J. Electrochem. Soc. 137, C5-C22 (1990)
[0026] Non-patent document 18: Wu, M. Q.; Snook, G. A.; Chen, G. Z.; Fray, D. J. Redox deposition of manganese oxide on graphite for supercapacitors. Electrochem. Commun. 6, 499-504 (2004)
[0027] Non-patent document 19: Zhu, S.; Zhou, H.; Hibino, M.; Honma, I.; Ichihara, M. Synthesis of MnO 2 nanoparticles confined in ordered mesoporous carbon using a sonochemical method. Adv. Funct. Mater. 15, 381-386 (2005)
[0028] Non-patent document 20: Man, J.; Fan, Z. J.; Wei, T.; Cheng, J.; Shao, B.; Wang, K.; Song, L. P. Zhang, M. L. Carbon nanotube/MnO 2 composites synthesized by microwave-assisted method for supercapacitors with high power and energy densities. J. Power Sources 194, 1202-1207 (2009)
[0029] Non-patent document 21: Reddy, A. L. M.; Shaijumon, M. M.; Gowda, S. R.; Ajayan, P. M. Multisegmented Au—MnO 2 /carbon nanotube hybrid coaxial arrays for high-power supercapacitor applications. J. Phys. Chem. C 114, 658-663 (2010)
[0030] Non-patent document 22: Hu, L. B.; Pasta, M.; Mantia, F. L.; Cui, L. F.; Jeong, S.; Deshazer, H. D.; Choi, J. W.; Han, S. M.; Cui, Y. Stretchable, porous, and conductive energy textiles. Nano Lett. 10, 708-714 (2010)
[0031] Non-patent document 23: Liu, R.; Lee, S. B. MnO 2 /poly(3,4-ethylenedioxythiophene) coaxial nanowires by one-step coelectrodeposition for electrochemical energy storage. J. Am. Chem. Soc. 130, 2942-2943 (2008)
[0032] Non-patent document 24: Chen, L.; Sun, L. J.; Luan, F.; Liang, Y.; Li, Y.; Liu, X. X. Synthesis and pseudocapactive studies of composite films of polyaniline and manganese oxide nanoparticles. J. Power Sources 195, 3742-3747 (2010)
[0033] Non-patent document 25: J. M. Tarascon, M. Armand, Nature 2001, 414, 359
[0034] Non-patent document 26: Y. Idota, T. Kubota, A. Matsufuji, Y. Maekawa, T. Miyasaka, Science 1997, 276, 1395
[0035] Non-patent document 27: J. Hassoun, S. Panero, P. Simon, P. L. Taberna, B. Scrosati, Adv. Mater. 2007, 19, 1632
[0036] Non-patent document 28: K. T. Nam, D. W. Kim, P. J. Yoo, C. Y. Chiang, N. Meethong, P. T. Hammond, Y. M. Chiang, A. M. Belcher, Science 2006, 312, 885
[0037] Non-patent document 29: Lee, K. T.; Jung, Y. S.; Oh, S. M. J. Am. Chem. Soc. 2003, 125, 5652-5653
[0038] Non-patent document 30: Winter, M.; Besenhard, J. O.; Spahr, M. E.; Novak, P. Adv. Mater. 1998, 10, 725-763
[0039] Non-patent document 31: Coward, G. R.; Leroux, F.; Power, W. P.; Ouvrard, G.; Dmowski, W.; Egami, T.; Nazar, L. F. Electrochem. Solid-State Lett. 1999, 2, 367-370
[0040] Non-patent document 32: Crosnier, O.; Brousse, T.; Devaux, X.; Fragnaud, P.; Schleich, D. M. J. Power Sources 2001, 94, 169-174
[0041] Non-patent document 33: Nazri, G.-A.; Pistoia G. Lithium Batteries Science and Technology; Kluwer: Boston, 2004
[0042] Non-patent document 34: I. A. Courtney, J. R. Dahn, J. Electrochem. Soc. 1997, 144, 2045
[0043] Non-patent document 35: M. Winter, J. O. Besenhard, Electrochim. Acta 1999, 45, 31
[0044] Non-patent document 36: S. Grugeon, S. Laruelle, R. Herrera-Urbina, L. Dupont, P. Poizot, J. M. Tarascon, J. Electrochem. Soc. 2001, 148, A285
[0045] Non-patent document 37: E. Shembel, R. Apostolova, V. Nagirny, I. Kirsanova, Ph. Grebenkin, P. Lytvyn, J. Solid St. Electrochem. 2005, 9, 96
[0046] Non-patent document 38: N. Li, C. Martin, J. Electrochem. Soc. 2001, 148, A164
[0047] Non-patent document 39: M. Wachtler, M. R. Wagner, M. Schmied, M. Winter, J. O. Besenhard, J. Electroanal. Chem. 2001, 12, 510
[0048] Non-patent document 40: Y. Yu, L. Gu , C. Zhu, P. A. van Aken, J. Maier, J. Am. Chem. Soc., 2009, 131 15984
[0049] Non-patent document 41: Y. Yu, L. Gu, C. Wang, A. Dhanabalan, P. A. van Aken, J. Maier, Angew. Chem. Int. Ed., 2009, 48, 6485
[0050] Non-patent document 42: J. O. Besenhard, J. Yang, M. Winter, J. Power Sources 1997, 68, 87
[0051] Non-patent document 43: J. Y. Lee, R. Zhang, Z. Liu, Electrochem. Solid-State Lett. 2000, 3, 167
[0052] Non-patent document 44: J. Yang, M. Wachtler, M. Winter, J. O. Besenhard, Electrochem. Solid-State Lett. 1999, 2, 161
[0053] Non-patent document 45: H. G. Yang and H. C. Zeng, Angew. Chem., Int. Ed., 2004, 43, 5930
[0054] Non-patent document 46: S. J. Han, B. C. Jang, T. Kim, S. M. Oh and T. Hyeon, Adv. Funct. Mater., 2005, 15, 1845
[0055] Non-patent document 47: J. Hassoun, S. Panero, P. Simon, P.-L. Taberna, B. Scrosati, Adv. Mater. 2007, 19, 1632
SUMMARY OF INVENTION
Problem to be Solved by the Invention
[0056] However, manganese dioxide has poor electron conductivity (10 −5 to 10 −6 S·cm −1 ), which limits charging/discharging speed and impedes use in high-output applications (non-patent document 11; non-patent document 16; non-patent document 17: Desilvestro, J.; Haas, O. Metal oxide cathode materials for electrochemical energy storage: A review. J. Electrochem. Soc. 137, C5-C22 (1990)). The development of manganese dioxide having increased levels of electroconductivity through the use of, for example, carbon (non-patent document 18: Wu, M. Q.; Snook, G. A.; Chen, G. Z.; Fray, D. J., “Redox deposition of manganese oxide on graphite for supercapacitors”, Electrochem. Commun. 6, 499-504 (2004); non-patent document 19: Zhu, S.; Zhou, H.; Hibino, M.; Honma, I.; Ichihara, M., “Synthesis of MnO 2 nanoparticles confined in ordered mesoporous carbon using a sonochemical method”, Adv. Funct. Mater. 15, 381-386 (2005); non-patent document 20: Yan, J.; Fan, Z. J.; Wei, T.; Cheng, J.; Shao, B.; Wang, K.; Song, L. P. Zhang, M. L., “Carbon nanotube/MnO 2 composites synthesized by microwave-assisted method for supercapacitors with high power and energy densities”, J. Power Sources 194, 1202-1207 (2009); non-patent document 21: Reddy, A. L. M.; Shaijumon, M. M.; Gowda, S. R.; Ajayan, P. M., “Multisegmented Au—MnO 2 /carbon nanotube hybrid coaxial arrays for high-power supercapacitor applications”, J. Phys. Chem. C 114, 658-663 (2010); non-patent document 22: Hu, L. B.; Pasta, M.; Mantia, F. L.; Cui, L. F.; Jeong, S.; Deshazer, H. D.; Choi, J. W.; Han, S. M.; Cui, Y., “Stretchable, porous, and conductive energy textiles”, Nano Lett. 10, 708-714 (2010)) or electroconductive polymers (non-patent document 23: Liu, R.; Lee, S. E. “MnO 2 /poly(3,4-ethylenedioxythiophene) coaxial nanowires by one-step coelectrodeposition for electrochemical energy storage. J. Am. Chem, Soc. 130, 2942-2943 (2008); non-patent document 24: Chen, L.; Sun, L. J.; Luan, F.; Liang, Y.; Li, Y.; Liu, X. X., “Synthesis and pseudocapactive studies of composite films of polyaniline and manganese oxide nanoparticles”, J. Power Sources 195, 3742-3747 (2010)) in order to improve electrical conductivity is an important problem.
[0057] Tin-based material substances, which are considered to show promise as electrode materials for lithium-ion secondary cells, are problematic in that they exhibit extreme changes in volume, and it is difficult to extend their battery lifespans. Moreover, no reports have been made as of yet regarding the control of changes in volume by controlling the morphology or form of tin, as well as related environmental factors (non-patent documents 40, 41).
Means of Solving the Problem
[0058] As the result of diligent research, the inventors focused on nanoporous gold (NPG) manufactured by selectively etching a binary gold/silver alloy, and discovered that, when the ceramic manganese dioxide was deposited upon the surface of a core (NPG) metal using a template technique (plating) involving a liquid phase deposition reaction under controlled conditions, it is possible to make use of the properties of the core skeleton as a template and to coat and/or deposit a ceramic deposit layer upon the surface of the core skeleton, successfully obtaining a nanoporous core/ceramic deposit nanostructure (composite) comprising a gold core having unique structural properties and a ceramic deposit. The inventors also successfully discovered that a nanoporous metal/ceramic composite hybrid material obtained in this manner is a superior functional material, thereby arriving at the present invention.
[0059] The inventors similarly succeeded in producing an NPG/SaO 2 nanocomposite using three-dimensional nanoporous gold (3D NPG) as a carrier and depositing ceramic SnO 2 upon the skeleton of the carrier, and discovered that, when the 3D NPG/SnO 2 nanocomposite is used as a lithium-ion battery (LIB) anode material, high reversible capacity is demonstrated during charge/discharge cycles, the problem of changes in volume can be solved, lifetime can be extended, and performance can be increased, thereby arriving at the present invention.
[0060] The present invention provides a novel nanoporous metal/ceramic composite material substance by combining chemical dealloying and an electroless plating treatment. In one specific embodiment, the present invention provides a novel nanoporous Au/MnO 2 electrode. In the nanoporous Au/MnO 2 electrode, three-dimensionally nanoporous gold (3D NPG) is not only active as a double-layer capacitor, but also functions as a good electroconductive agent, enhancing the pseudocapacitor ability of the MnO 2 . The ceramic (metallic oxide) hybrid material substance of the present invention demonstrates an extremely high specific capacitance, extremely high energy density, and extremely superior cycle stability, and exhibits optimal properties as an electrode material for high-performance super capacitor (SC) devices.
[0061] In another specific embodiment, the present invention provides a novel three-dimensional nanoporous gold (3D NPG)/SnO 2 composite, as well as a method for manufacturing the same and a LIB using the 3D NPG/SnO 2 composite as an anode material.
[0062] The present invention provides:
[0063] (1) a nanoporous metal core/ceramic deposit layer composite, wherein the nanoporous metal core/ceramic composite is characterized in that the composite has a ceramic deposit and a metal core, and the core is of a nanoporous metal;
[0064] (2) the composite according to (1), characterized in that the deposit layer is selected from the group consisting of MnO 2 , TiO 2 , CeO 2 , Al 2 O 3 , BaTiO 3 , SnO 2 , WO 3 , In 2 O 3 , V 2 O 5 , Nb 2 O 5 , Ta 2 O 5 , TaNbO 5 , SiO 2 , ZrO 2 , LaCoO 3 , LaCrO 3 , LaMnO 3 , LaFeO 3 , Bi 2 O 3 , SrCoO 3 , Co 3 O 4 , CuO, NiO, PrMnO 3 , SrTiO 3 , BeO, MgSiO 3 , Mg 2 SiO 4 , Fe 2 O 3 , Fe 3 O 4 , ZnO, PbTiO 3 , RuO 2 , and CrO 2 ;
[0065] (3) the composite according to (1) or (2), characterized in that the core is a nanoporous metal, and the ceramic is deposited or adhered upon the surface of the metal of the interpore walls of the nanoporous metal;
[0066] (4) the composite according to one of (1) to (3), characterized in that the core is nanoporous gold or nanoporous copper;
[0067] (5) the composite according to (4), characterized in that the nanoporous gold is obtained by dealloying a gold/silver alloy;
[0068] (6) a method for manufacturing a nanoporous metal core/ceramic deposit layer composite, wherein the method for manufacturing a nanoporous metal core/ceramic composite is characterized in that a nanoporous metal core made of a metal is subjected to a plating treatment, and a ceramic layer is formed upon the surfaces of the interiors of the pores in the core;
[0069] (7) a supercapacitor device characterized in that the composite according to any one of claims (1) to (5) is used as an electrode; and
[0070] (8) a lithium-ion battery characterized in that the composite according to any one of claims (1) to (5) is used as an electrode.
Effects of the Invention
[0071] In the present invention, a novel nanoporous metal/ceramic hybrid material substance useful as an electrode material for a high-performance supercapacitor (SC) device or long life lithium-ion battery (LIB), such as a nanoporous gold (NPG)/ceramic hybrid film, is provided. In particular, a nanoporous Au (NPG)/MnO 2 hybrid film is useful as an electrode material for a high-performance supercapacitor (SC) device, and a 3D NPG/SnO 2 hybrid film has high power storage capacity, and is useful as an electrode material for an ultra-long life LIB. The hybrid material substance according to the present invention demonstrates superior electrical properties, and is useful for a variety of applications as a material used in combination with a variety of electrical/electronic devices, such as dielectrics, SC electrodes, LIB electrodes, energy storage devices, power sources and backup power sources for portable phones and personal computers, power sources and backup power sources for electronic control devices for automobiles, batteries for electric cars, and power storage devices.
[0072] Other objects, features, advantages, and aspects of the present invention will be apparent to a person skilled in the art from the following description. However, it should be noted that the matters disclosed in the present specification, including the matters and specific examples described below, indicate a preferred embodiment of the present invention, and are given merely for illustrative purposes. Various changes and/or improvements (or modifications) within the spirit and scope of the present invention disclosed in the present specification will be readily apparent to a person skilled in the art on the basis of knowledge from the following description and other parts of the specification. All reference documents cited in the present specification are cited for explanatory purposes, and the contents thereof should be construed as being included herein as part of the present specification.
BRIEF DESCRIPTION OF DRAWINGS
[0073] FIG. 1( a ) is a schematic illustration of a process of manufacturing a nanoporous Au/ceramic composite material substance, specifically, an NPG/MnO 2 composite, combining chemical dealloying and an electroless plating treatment. Bare nanoporous gold is obtained in a first process (dealloying), and MnO 2 nanocrystals are grown upon the gold framework substrate via a plating treatment in a subsequent process to obtain the composite material substance. FIG. 1( b ) is an SEM image (plan view) of dealloyed NPG. FIG. 1( c ) is an SEM image (plan view) of an NPG/MnO 2 composite obtained after performing a plating treatment for 10 minutes. FIG. 1( d ) is a TEM image of an NPG/MnO 2 composite obtained after performing a plating treatment for 20 minutes. FIG. 1( e ) is an HRTEM image of an NPG/MnO 2 composite obtained after performing a plating treatment for 20 minutes.
[0074] FIG. 2( a ) is a cyclic voltammogram of NPG/ceramic composite material substances according to the present invention, i.e., NPG/MnO 2 composites, obtained using dealloyed (bare) NPG and various plating treatment times. Measurements were taken at room temperature in an aqueous solution of 2M Li 2 SO 4 . The scanning speed was 50 mV/s. FIG. 2( b ) shows volumetric capacitance as a function of plating treatment time. Capacitance was calculated from CV at a scanning speed of 50 mV/s. FIG. 2( c ) shows charge/discharge curves at a current density of 0.5 A/g for aqueous solution SCs using an electrode of dealloyed (bare) NPG and electrodes using NPG/ceramic composite material substances, i.e., NPG/MnO 2 composites, according to the present invention obtained using various plating treatment times. FIG. 2( d ) shows the specific capacitances at various discharge current densities of aqueous solution SCs using an electrode of dealloyed (bare) NPG and electrodes using NPG/ceramic composite material substances, i.e., NPG/MnO 2 composites, according to the present invention obtained using various plating treatment times.
[0075] FIG. 3( a ) shows the scanning speed dependency of a cyclic voltammogram at various scanning speeds from 10 to 100 mV/s of an electrode of the NPG/ceramic composite electrode according to the present invention, i.e., an electrode of an NPG/MnO 2 composite (20 minute plating treatment). FIG. 3( b ) shows the equivalent specific capacitances of MnO 2 deposited via plating treatment as a function of scanning speed.
[0076] FIG. 4( a ) shows a Ragone plot (energy density over power density) for an NPG/MnO 2 supercapacitor (SC). Values are for a 2M Li 2 SO 4 aqueous solution. ▴: 5-minute plating treatment, : 10-minute plating treatment, ▪: 20-minute plating treatment. For comparison, data from documents discussing other MnO 2 electrodes is also plotted. Specifically, an MnO 2 electrode (energy density: power density, 3.3 Wh/kg, 3.1 kW/kg, ◯, □), a coaxial CNT/MnO 2 electrode (2.9 Wh/kg, 11 kW/kg, ▾), an Au-CNT/MnO 2 array (4.5 Wh/kg, 33 kW/kg, ), an activated charcoal-MnO 2 hybrid electrode (7.6 Wh/kg, 4.1 kW/kg, ⋄, Δ, ∇), a CNT/MnO 2 composite electrode (25.2 Wh/kg, 45.4 kW/kg, ), and a commercially available supercapacitor. FIG. 4( b ) shows the cycle stability of the NPG/MnO 2 (20-minute plating treatment) composite electrode according to the present invention as a function of number of cycles.
[0077] FIG. 5 shows EDS spectra for nanoporous Au/ceramic composite material substances, i.e., NPG/MnO 2 composites. FIG. 5( a ): 5-minute plating treatment. FIG. 5( b ): 10-minute plating treatment. FIG. 5( c ): 10-minute plating treatment. The Cu peak is for a copper sample holder.
[0078] FIG. 6 is an HRTEM image of an NPG/MnO 2 composite obtained after performing a plating treatment on MnO 2 for 5 minutes.
[0079] FIG. 7 shows measured internal resistance values for an NPG/MnO 2 (20-minute plating treatment) composite electrode according to the present invention. Values are for a 2M Li 2 SO 4 aqueous solution (electrolyte solution). Measurements were taken using discharge currents of 3.3, 6.7, 10, 13.3, 16.7, and 20 A/g.
[0080] FIG. 8( a ) is a photograph of the exterior appearance of a thin-film supercapacitor (SC) constructed using an NPG/MnO 2 composite sheet according to the present invention as an electrode. An Li 2 SO 4 aqueous solution was used as the electrolyte, and tissue paper was used as the separator. FIG. 8( b ) is a schematic illustration of the structure of a nanoporous Au/ceramic composite SC, specifically, an NPG/MnO 2 SC, according to the present invention.
[0081] FIG. 9 shows CV curves for supercapacitors (SC) (aqueous solution electrolyte) based on an NPG/MnO 2 composite electrode according to the present invention. FIG. 9( a ) is for a 0-minute MnO 2 plating treatment, FIG. 9( b ) is for a 5-minute MnO 2 plating treatment, and FIG. 9( c ) is for a 10-minute MnO 2 plating treatment. Measurements were taken at different scanning speeds.
[0082] FIG. 10 shows a Ragone plot for NPG/MnO 2 supercapacitors (SCs) according to the present invention and commercially available SCs.
[0083] FIG. 11 is a schematic illustration of a process of manufacturing a nanoporous Au/ceramic composite material substance, specifically, an NPG/SnO 2 composite, combining chemical dealloying and an electroless plating treatment. The plated tin was immediately converted to SnO 2 in an electrolytic solution or in air. FIG. 11( a ) shows the schematic structure of a three-dimensional nanoporous gold (3D NPG) substrate (carrier) prepared by chemically dealloying an Ag 65 Au 35 (at. & %) foil. FIG. 11( b ) shows the schematic structure of nanocrystalline tin (specifically, nanocrystalline SnO 2 ) trapped and deposited on the surface of the walls of a channel (tunnel) of 3D NPG. FIG. 11( c ) is an SEM image of 3D NPG corresponding to FIG. 11( a ). FIG. 11( d ) is a SEM image for an NPG/Sn composite (specifically, an NPG/SnO 2 composite) corresponding to FIG. 11( b ).
[0084] FIG. 12 shows SEM images and TEM images for a bare 3D NPG/Sn composite (specifically, a 3D NPG/SnO 2 composite). FIG. 12( a ) is an SEM image (plan view) for a 3D NPG/SnO 2 composite. FIG. 12( b ) is a magnified SEM image of the cross section of a 3D NPG/SnO 2 composite. FIG. 12( c ) is a TEM image (plan view) of a 3D NPG/SnO 2 composite and an inset SAED pattern. FIG. 12( d ) is an HRTEM image of a 3D NPG/SnO 2 composite. Particles of nanocrystalline tin (specifically, nanocrystalline SnO 2 ) are shown adhered to a 3D NPG substrate (carrier).
[0085] FIG. 13 shows the results from tests of the electrochemical properties of lithium-ion batteries using 3D NPG/SnO 2 composite electrodes. Charge/discharge cycles were performed for Li + /Li from 0.005 V to 1.0 V. FIG. 13( a ) shows a voltage profile for 3D NPG/SnO 2 composite electrode at a 0.1 C cycle rate. No noteworthy change was observed at different numbers of cycles. FIG. 13( b ) shows a voltage profile for 3D NPG/SnO 2 composite electrode at various C rates from 0.005 V to 1.0 V. FIG. 13( c ) shows a capacity/cycle number curve for a 3D NPG/SnO 2 composite electrode when a charge/discharge cycle was performed at a cycle rate of 0.1 C.
[0086] FIG. 14( a ) is an ex situ SEM image for a 3D NPG/SnO 2 composite after being used as an electrode for a lithium-ion battery for 140 charge/discharge cycles. FIG. 14( b ) is a graph of charge capacity over cycle number for a lithium-ion battery using a 3D NPG/SnO 2 composite electrode used to perform charge/discharge cycles at various C rates (1 C to 8 C) from 0.005 V to 1.0 V.
[0087] FIG. 15 is a graph showing EDX analysis results for a manufactured 3D NPG/Sn composite. The composite comprised about 79.6 weight % electrochemically active tin. Three-dimensional nanoporous gold (3D NPG) substrate (carrier) content was 20.4 wt %. The other signals for Cu, C, and O are believed to be from a carbon-lacey film supported by the copper mesh used to perform TEM measurement.
DESCRIPTION OF EMBODIMENTS
[0088] The present invention provides a hybrid material substance in which the surface of a nanoporous metal is modified using a ceramic, as well as a method for manufacturing same. The present invention also provides a technique of modifying the metal surface of a nanoporous metal using a ceramic. In particular, the present invention provides a nanoporous metal/ceramic composite structure of at least two constituents; for example, an at least binary nanoporous metal core/ceramic deposit layer composite thin film (or a ceramic-composite nanoporous metal foil), and a method for manufacturing same. The nanoporous metal core/ceramic composite structure typically has (1) a ceramic deposit layer (shell or film layer) and a core (interior or skeleton) of metal, the skeleton (starter nanoporous metal) being a porous structure having multiple nanosize pores of an average pore size of roughly 80 nm or less, roughly 60 nm or less, in some cases roughly 50 nm or less, especially roughly 40 nm or less, or roughly 30 nm or less, or, for example, roughly 25 nm or less; and the nanoporous metal/ceramic composite structured metal being a nanoporous metal/ceramic composite hybrid substance showing markedly superior electrical properties and/or yield superior capacitor performance and/or having structural properties and/or a shape allowing for SC action to be demonstrated in a device using the substance as an SC electrode or an LIB electrode. Moreover, the substance is a nanoporous metal/ceramic composite hybrid substance having a structural properties and/or a shape allowing for superior charge/discharge cycle properties and/or long-life performance, high charge/discharge capacity-maintaining performance, and the like to be demonstrated when used as an LIB electrode.
[0089] The present invention provides an application for a hybrid nanoporous metal/ceramic composite in which a functional nanoporous metal core having an adjusted nanopore size is surface-modified using a ceramic constituting a deposit layer; for example, as a material used in combination with a variety of electrical/electronic devices, such as dielectrics, SC electrodes, lithium-ion batteries (LIES), energy storage devices, backup power sources for portable phones and personal computers, backup power sources for electronic control devices for automobiles, power source devices for automobiles, and power storage devices.
[0090] The metal constituting the nanoporous metal core/ceramic composite core can be selected from among various metals, but a metal obtained by dealloying the alloy metals listed below is preferred. Typical examples of the metal constituting the core include gold, a gold-containing alloy, copper, or a copper-containing alloy. Especially preferred examples include nanoporous gold (NPG) and nanoporous copper (NPC).
[0091] As used herein, the terms “dealloy,” “dealloying,” and “selective corrosion” are synonymous, and refer to bringing an alloy metal, alloy metal material, a part thereof, or an alloy metal foil (or alloy metal thin film) into contact with a medium having a corrosive (or etching) action and removing at least one metallic constituent from the alloy metal to form a nanoporous metal, nanoporous material, a part thereof, or a nanoporous metal foil (or nanoporous metal thin film), or to bringing the metal and the corrosive medium into contact for a period of time sufficient to remove at least one metallic constituent from the alloy and form a nanoporous metal (including nanoporous metal thin films).
[0092] Examples of such nanoporous metals include metals having a nanoporous structure having an average pore size of about 100 nm or less metals having a nanoporous structure having an average pore size of about 80 nm or less; in some cases, metals having a nanoporous structure having an average pore size of about 70 nm or less; metals having a nanoporous structure having an average pore size of about 60 nm or less; for example, about 50 nm or less; in other cases, metals having a nanoporous structure having an average pore size of about 40 nm or less; metals having a nanoporous structure having an average pore size of about 30 nm or less, for example, about 20 nm or less; more preferably, metals having a nanoporous structure having an average pore size of about 10 nm or less; and especially metals having a nanoporous structure having an average pore size of about 8 nm or less, for example, about 5 nm or less.
[0093] As used herein, “metal foil” may refer to a thin sheet of a metal alloy and/or a thin film of a metal alloy. There is no particular limit upon the thickness of the metal foil as long as the desired objects can be achieved; typically, the film may have a thickness of about 50 nm or more; or about 50 μm or less; about 10 μm or less; about 5.0 μm or less; about 2.5 μm or less, for example, 2.0 μm or less; or about 1.5 μm or less, for example, about 1.0 μm or less. Naturally, the metal foil may also have a thickness of about 0.5 μm or less, or about 0.1 μm or less. The alloy used to manufacture the metal foil may comprise two or more metal elements as constituents. The alloy used to manufacture the nanoporous metal constituting the framework (core) comprises at least two metal elements as constituents, in which, for example, one of the two metal elements is a metal element that is sensitive to a corrosive medium, and the other is a metal element that is resistant to the corrosive medium. Moreover, one of the two metal elements has higher ionization energy or ionization potential than the other, or the other of the two metal elements may have a lower ionization potential than the first metal element.
[0094] The combination of metals (metal elements) used to obtain the starter material alloy for the core can be one in which the metal have different chemical properties so as to allow for dealloying. Examples of metal elements include elements selected from the group consisting of transition metal elements, typical metal elements, and the like; for example, iron group elements, platinum group elements, copper group elements, zinc group elements, aluminum group elements, manganese group elements, chromium group elements, earth-acid elements, titanium group elements, rare earth elements, alkali earth metal elements, alkali metal elements, lanthanide elements, actinide elements, tin, lead, germanium, bismuth, antimony, and the like. The alloy may contain a typical non-metal element, examples including carbon group elements, nitrogen group elements, oxygen group elements, halogens, boron, and the like.
[0095] Suitable alloys are not limited thereto, and may include constituents selected as appropriate from among those known to a person skilled in the relevant field of art, such as gold (Au), silver (Ag), copper (Cu), zinc (Zn), aluminum (Al), nickel (Ni), tin (Sn), manganese (Mn), iron (Fe), cobalt (Co), chromium (Cr), molybdenum (Mo), tungsten (W), vanadium (V), niobium (Nb), titanium (Ti), zirconium (Zr), magnesium (Mg), platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), osmium (Os), iridium (Ir), and the like. More specific examples of alloys include Au—Ag alloys, Au—Cu alloys, Cu—Mn alloys, Cu—Al alloys, Cu—Zn alloys, Cu—Mg alloys, Ni—Al alloys, Ni—Mg alloys, Ni—Mn alloys, Cu—Cr alloys, Sn—Pb alloys, Sn—In alloys, Ag—Cu alloys, Au—Ni alloys, Au—Pd alloys, and the like. Preferred alloys that can be dealloyed to obtain a nanoporous metal include Au—Ag alloys, Cu—Mn alloys, Cu—Zn alloys, and the like, of which Au—Ag alloys and Cu—Mn alloys are especially preferred.
[0096] In the present invention, the alloy constituting the starter substance is preferably in the form of a metal foil or the like. The alloy foil preferably has a thickness of about 50 nm to about 50 μm, about 50 nm to about 10 μm, more preferably about 60 nm to about 5.0 μm, about 70 nm to about 1.0 μm, still more preferably about 80 nm to about 500 nm, or about 90 nm to about 250 nm. Specific preferred examples include a metal alloy foil having a thickness of about 90 nm to about 150 nm, or a metal alloy foil having a thickness of about 100 nm.
[0097] In one embodiment of the present invention, the metal alloy may contain the constituent metal elements at various proportions (percentages). For example, in the case of a gold/silver alloy (Au—Ag alloy), the alloy may contain about 50% to about 80% gold (Au) and a remainder of silver (Ag). A more preferred example is an alloy containing gold and silver at proportions of about 35 at % gold and about 65 at % silver, i.e., a 35Au-65Ag alloy. The metal foil is prepared, for example, in the following manner. The metal elements of the alloy material are mixed, placed in a crucible, heated, and melted, after which a thin film can be obtained via a melt spinning method. Alternatively, the molten metal mixture can be poured into a mold and cooled to obtain an alloy ingot. Next, the alloy is drawn into a strip shape, then cut into chips using a guillotine device. The obtain alloy sheet chips (strips) are placed on foil paper in several overlapping layers, hammered, and cut, and this hammering process is repeated to obtain a metal foil. A commercially available metal foil can also be used, and foils having various thickness or gold/silver ratios are obtainable.
[0098] In another embodiment of the present invention, an alloy of, for example, copper and manganese (a Cu—Mn alloy) is used, in which case the alloy contains, for example, about 10% to about 70% copper (Cu), with the remainder being manganese (Mn). A more preferred example is an alloy containing copper and manganese at proportions of about 30 at % Cu and about 70 at % manganese, i.e., a 30Cu-70Mn alloy. A metal foil is prepared in a manner similar to that used with the gold/silver alloy. A commercially available metal foil can also be used, and foils having various thickness or copper/manganese ratios are obtainable.
[0099] The medium exhibiting corrosive (or etching) action used in the present invention is capable of selectively dissolving at least one of the metals constituting the metal alloy. The composition of the corrosive medium can he selected as appropriate according to the type of metal alloy to be dealloyed. If the alloy contains two or more constituent metal elements, at least one of the constituent metal elements is dissolved. An example of a preferred corrosive medium is an acid. Examples of acids suitable for the present invention include organic acids and inorganic acids. A preferred example is an inorganic acid, and more preferred examples include mineral acids such as nitric acid, sulfuric acid, hydrochloric acid, and perchloric acid. In one preferred embodiment of the present invention, the acid is nitric acid or hydrochloric acid. A single acid or a mixture of acids may be used. The corrosive medium may be in a concentrated or a diluted form. If an Au—Ag alloy is used, an about 70% nitric acid aqueous solution can preferably be used, or a stronger or weaker solution can be used. If a Cu—Mn alloy is used, an about 0.025 M hydrochloric acid aqueous solution can preferably be used, or a stronger or weaker solution can be used.
[0100] In accordance with one embodiment of the present invention, the treatment, i.e., dealloying of the alloy constituting starter material by the corrosive medium can be performed at room or lower temperature, but the present invention is not limited thereto, and a higher temperature also possible. The dealloying can be more preferably performed at room temperature in the case of an Au—Ag alloy or Cu—Mn alloy. In a preferred embodiment of the present invention, the dealloying is performed at a temperature of about 100° C. to about −45° C., more preferably about 50° C. to about 0° C. The dealloying can be performed for an arbitrarily selected length of time, but is preferably performed for an amount of time sufficient to remove at least one of the metallic constituents from the alloy and form a nanoporous metal. In a preferred embodiment of the present invention, the dealloying may be performed for about 30 minutes to about 48 hours, preferably for about 1 hour to about 20 hours. The dealloying treatment temperature and treatment time can be selected as appropriate according to the target nanoporous metal.
[0101] The present invention provides a method for manufacturing a nanoporous metal/ceramic composite (nanoporous metal/ceramic hybrid substance). In this manufacturing method, a metal nanoporous metal core (skeleton) is subjected to a precipitation (deposition) reaction or to a plating treatment (electroless plating) to form (or deposit) a ceramic deposit upon the surfaces of the interior of the pores in the core. The deposit-forming reaction is effected by performing in situ precipitation (deposition) of a ceramic (for example, a metallic oxide) upon the metal constituting the skeleton (for example, gold in the case of nanoporous gold (NPG)), thereby depositing and/or forming a ceramic layer (packed layer) on the surface of the core. Typically, the nanoporous metal constituting the core functions as a template and as a carrier (self-sustaining substrate), and imparts the obtained composite with the feature of nanoporosity. The metallic oxide or other ceramic is deposited on the surface of the core metal at the surface of the core so as to cover the surface of the core and/or be packed or precipitated in the channels (tunnels) within the porous body, thereby advancing the deposit-forming reaction filling the channels (tunnels) present in the metal skeleton of the framework with the ceramic component. A nanoporous composite retaining the structural characteristics (nanoporous structure) of the core is thus obtained.
[0102] The plating treatment can be performed by immersing the nanoporous metal substrate constituting the core into a ceramic source-containing liquid containing a source of the metal ions constituting the ceramic. A water-based or aqueous solution is typically favorably used as the ceramic source-containing liquid. As shall be apparent, it is also possible to use a mixture of water and an organic solvent. A water-miscible organic solvent can be used, examples including alcohols, ethers, ketones, acid amides, carboxylic acids, esters, nitriles, dioxanes, and saturated nitrogenous heterocycles. The plating treatment can be one in which a ceramic is applied to the metal surfaces of the channels (tunnels) in the nanoporous metal substrate via electrolytic deposition, electroless deposition, liquid phase deposition, or the like. In one specific embodiment, the plating treatment can be effected by immersing the nanoporous metal constituting the core in a ceramic source-containing liquid containing a source of metal ions constituting the ceramic in the presence of a reductant, oxidizing agent, acid, alkali, or the like selected as necessary at a predetermined temperature for a predetermined amount of time while stirring. Examples of ceramic sources include chloride compounds of the metal, complex compounds of the metal, and solutions containing the same, such as metal peroxides, halides, nitrates, sulfates, organic acid salts, cyanide, and other compounds, and amino complexes, chloride complexes, fluoro complexes, and other complex compounds. If a fluoro complex is used as the ceramic source, the formation of a metallic oxide can be promoted by adding boric acid, metallic aluminum, or water to or raising the temperature of a metal fluoro complex. In a method in which, for example, a solution of a metal peroxide such potassium permanganate is subjected to a reduction treatment, it is possible to use, for example, a reductant such as hydrazine, formaldehyde, or the like. It is also possible to apply a method known as a sol-gel method in the relevant field of art to form the ceramic.
[0103] Typical ceramic sources include elements selected from the group consisting of transition metal elements, typical metal elements, and the like; for example, iron group elements, platinum group elements, copper group elements, zinc group elements, aluminum group elements, manganese group elements, chromium group elements, earth-acid elements, titanium group elements, rare earth elements, alkali earth metal elements, alkali metal elements, lanthanide elements, actinide elements, tin, lead, germanium, bismuth, antimony, and the like. The ceramic source may contain a typical non-metal element, examples including carbon group elements, nitrogen group elements, oxygen group elements, halogens, boron, and the like.
[0104] Suitable ceramics are not limited thereto, and a suitable ceramic may be selected as appropriate from among those known to a person skilled in the relevant field of art; examples include oxides containing metals selected from: manganese (Mn), aluminum (Al), titanium (Ti), zirconium (Zr), beryllium (Be), magnesium (Mg), silicon (Si), antimony (Sb), yttrium (Y), copper (Cu), zinc (Zn), nickel (Ni), tin (Sn), iron (Fe), cobalt (Co), chromium (Cr), molybdenum (Mo), tungsten (W), vanadium (V), niobium (Nb), tantalum (Ta), rhenium (Re), gold (Au), silver (Ag), platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), osmium (Os), iridium (Tr), barium (Ba), and germanium (Ge); lanthanides such as lanthanum (La), cerium (Ce), praseodymium (Pr), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), and ytterbium (Yb); actinides; and the like.
[0105] Typical, non-limiting examples of ceramics include MnO 2 , TiO 2 , CeO 2 , Al 2 O 3 , BaTiO 3 , SnO 2 , WO 3 , In 2 O 3 , V 2 O 5 , Nb 2 O 5 , Ta 2 O 5 , TaNbO 5 , SiO 2 , ZrO 2 , LaCoO 3 , LaCrO 3 , LaMnO 3 , LaFeO 3 , Bi 2 O 3 , SrCoO 3 , PrMnO 3 , SrTiO 3 , BeO, MgSiO 3 , Mg 2 SiO 4 , Fe 2 O 3 , Fe 3 O 4 , ZnO , PbTiO 3 , RuO 2 , CrO 2 , and the like. A particular example of a ceramic is a pseudocapacitative material, with various materials such as MnO 2 , TiO 2 , CeO 2 , SnO 2 , and the like being known one of which can be selected as long as no particular pejorative effect is yielded.
[0106] In a specific embodiment of the present invention, nanoporous gold (NPG) is modified (embellished) using a ceramic. For example, an aqueous solution of potassium permanganate can be used to deposit MnO 2 on the surfaces of the interior walls of the channels in the pore of the NPG, a reductant such as hydrazine preferably being added to the potassium permanganate aqueous solution. The potassium permanganate concentration of the potassium permanganate aqueous solution can be selected as appropriate in order to obtain the target MnO 2 layer; for example, the concentration is roughly 0.01 to 1.0 M, preferably roughly 0.05 to 0.20 M, most preferably roughly 0.1 M. The hydrazine concentration of the potassium permanganate aqueous solution can be selected as appropriate in order to obtain the target MnO 2 layer. The amount of MnO 2 adhering to the surface of the NPG can also be altered by controlling the reaction time; for example, if a 0.01M potassium permanganate aqueous solution is used in the presence of hydrazine, the reaction time is roughly 5 to 120 minutes, preferably roughly 5 to 35 minutes, and most preferably roughly 20 minutes. The amount of ceramic adhering to the surface of the NPG can also be altered by controlling reaction conditions such as the metal ion concentration of the ceramic source, the reductant/dispersing agent/surfactant if one is added, reaction time, and the like.
[0107] If SnO 2 or the like is deposited on the surface of the interior walls of the channels of the pores in the NPG, a tin chloride aqueous solution may be used, for example, to add a reductant such as hydrazine, deposit tin nanocrystals, then convert the nanocrystals to nanocrystalline SnO 2 by placing the NPG in an oxygenated environment such as an electrolytic solution or air. The SnCl 2 concentration can be selected as appropriate in order to obtain the target SnO 2 layer; for example, the concentration is roughly 0.01 to 2.0 M, preferably roughly 0.1 to 1.0 M, most preferably roughly 0.5 M. The hydrazine concentration of the tin chloride aqueous solution can be selected as appropriate in order to obtain the target SnO 2 layer. The reaction time can be selected as appropriate in order to obtain the desired results; for example, the reaction time is roughly 5 minutes to 30 hours, preferably from 5 to 18 hours, more preferably from 10 to 14 hours, and most preferably 12 hours.
[0108] The metal surface of the nanoporous metal of the core obtained according to the method of the present invention typically has a core nanoporous metal base structure containing a plurality of nanosized (from about 1 nm to about 100 nm) holes (or pores, channels, or tunnels), in which case the holes maintain a so-called open, bicontinuous nanoporous morphology, in which the holes have at least an opening and are continuous in two directions. Typically, the nanoporous metal of the core manufactured via dealloying as described above is used as a template, and thus retains structural properties reflecting the skeleton structure of the core. The core nanoporous metal/ceramic composite hybrid substance will have a core nanoporous metal base structure having a plurality of pores of sizes in a range from about 1.5 nm to about 80 nm, preferably a core nanoporous metal base structure having a plurality of pores of sizes in a range from about 2 nm to about 70 nm, more preferably a core nanoporous metal base structure having a plurality of pores of sizes in a range from about 2.5 nm to about 60 nm, a core nanoporous metal base structure having a plurality of pores of sizes in a range from about 3 nm to about 50 nm, a core nanoporous metal base structure having a plurality of pores of sizes in a range from about 3 nm to about 40 nm, a core nanoporous metal base structure having a plurality of pores of sizes in a range from about 3 nm to about 30 nm, or a core nanoporous metal base structure having a plurality of pores of sizes in a range from about 3 nm to about 20 nm. Typically, the abovementioned pore sizes indicate the average size. The abovementioned pore sizes may also indicate diameter size.
[0109] Typically, the portion of the core nanoporous metal/ceramic composite hybrid substance derived from the core nanoporous metal having the plurality of holes (or pores) is derived from holes having the sizes described above and communicates with the interior to form interior tunnels, and these tunnels normally communicate with each other to form a labyrinth-like core nanoporous metal-derived based structure. In a preferred instance, the nanoporous metal has a plurality of holes having an average hole length of about 12 nm or more, a plurality of holes having an average hole length of about 14 nm or more, preferably a plurality of holes having an average hole length of about 16 nm or more, more preferably a plurality of holes having an average hole length of about 18 nm or more, a plurality of holes having an average hole length of about 15 nm to about 50 nm, more preferably a plurality of holes having an average hole length of about 20 nm or more, still more preferably a plurality of holes having an average hole length of about 22 nm or more, or a plurality of holes having an average hole length of about 24 nm or more.
[0110] The core nanoporous metal/ceramic composite typically reflects the skeletal structure of the nanoporous metal used as a cast and retains a core nanoporous metal-derived base structure having interpore walls (ligaments, tunnel walls, or skeleton) having widths in a range from about 2 nm to about 80 nm, ligaments having widths in a range from about 2.5 nm to about 50 nm in some instances, ligaments having widths in a range from about 2.5 nm to about 45 nm, ligaments having widths in a range from about 3 nm to about 40 nm, ligaments having widths in a range from about 3 nm to about 35 nm, more preferably ligaments having widths in a range from about 3.5 nm to about 30 nm, ligaments having widths in a range from about 4 nm to about 20 nm, more preferably ligaments having widths in a range from about 5 nm to about 10 nm, ligaments having widths in a range from about 3 nm to about 8 nm, or ligaments having widths in a range from about 3 nm to about 5 nm. In a different embodiment, the nanoporous metal/ceramic composite obtained according to the method of the present invention typically has ligaments having widths in a range from about 5 nm to about 10 nm, preferably ligaments having widths in a range from about 5 nm to about 15 nm, more preferably ligaments having widths in a range from about 5 nm to about 20 nm, ligaments having widths in a range from about 5 nm to about 25 nm, preferably ligaments having widths in a range from about 5 nm to about 35 nm, more preferably ligaments having widths in a range from about 5 nm to about 45 nm, or ligaments having widths in a range from about 5 nm to about 50 nm. Typically, the abovementioned ligament sizes indicate the average size.
[0111] The size of the ligaments may refer to the thickness (diameter) of the walls of the pores (or tunnels). In a preferred instance, the nanoporous metal/ceramic composite has a plurality of ligaments having an average length (or tunnel wall length) of about 11 nm or more, a plurality of ligaments having an average length (or tunnel wall length) of about 12 nm or more in some instances, preferably a plurality of ligaments having an average length (or tunnel wall length) of about 13 nm or more, and more preferably a plurality of ligaments having an average length (or tunnel wall length) of about 15 nm or more, or a plurality of tunnel walls having an average length of about 15 nm to about 50 nm, more preferably a plurality of tunnel walls having an average length of about 16 nm or more, preferably a plurality of tunnel walls having an average length of about 17 nm or more, or a plurality of tunnel walls having an average length of about 18 nm or more. The ligaments are constituted by the metal and other components remaining after dealloying. A typical nanoporous metal/ceramic composite has the features shown in FIGS. 1 and 6 .
[0112] In the nanoporous metal/ceramic composite, the surfaces of the ligaments are covered by a layer (or film) or ceramic, or ceramic is deposited (or packed) thereupon. Under observation, the ceramic layer may substantially uniformly cover the surfaces of the ligaments, and can cover the surfaces of the interior walls of the tunnels extending into the interior or be packed into the interior of the tunnels. The thickness of the ceramic layer film (deposit) can be controlled using a variety of methods.
[0113] In accordance with one embodiment of the present invention, the nanoporous metal/ceramic composite is in the form of a thin film, and films of various thicknesses can be manufactured. The thickness of the nanoporous metal may different according to the thickness of the alloy starter material used.
[0114] In accordance with one embodiment of the present invention, the nanoporous metal/ceramic composite is in the form of an extremely fragile thin film, and is therefore normally handled or used mounted on a substrate (or base plate) (i.e., supported by the substrate). In a preferred embodiment of the present invention, the substrate has a flat-surfaced sheet or sheet-like form. In another preferred embodiment of the present invention, the substrate may have a convex surface, a concave surface, a spherical shape, a cylindrical shape, or an alternatingly convex and concave surface. In a typical instance, the substrate is a sheet of paper or the like, a glass sheet, a silicon sheet, a resin sheet, a ceramic sheet, or the like. In accordance with an embodiment of the present invention, the substrate can be made from a variety of materials. For example, the substrate can be manufactured from glass, ceramic, an insoluble metal, graphite or another carbonaceous material, rubber, nylon, an acrylic resin, polyethylene, a polymer material such as a polyethylene terephthalate resin, or another substance.
[0115] In accordance with one embodiment of the present invention, a ceramic@nanoporous gold (ceramic@NPG) composite can be synthesized using a template method involving a liquid phase deposition method, and the composite can be used as a material for a supercapacitor (SC) and/or a material for a lithium-ion battery (LIB). Specifically, a nanoporous gold/ceramic structure can be provided using nanoporous gold (NPG) having a plurality of open holes and a plurality of bicontinuous holes as a base frame via a simple in situ wet metallurgical method. A ceramic (for example, MnO 2 or another pseudocapacitative material substance) is placed on the surfaces of the interpore walls of the NPG, thereby allowing for the controlled deposition of a ceramic layer of suitable thickness. It has been discovered that, using a reductant such as hydrazine and or other additives, the ceramic layer formation reaction speed can be controlled, and three-dimensional nanoporosity can be maintained throughout the ceramic formation reaction (plating treatment). Thus, a technique using the same is also provided. The obtained porous nanocomposite exhibited effects as a dramatically superior supercapacitor electrode material compared to NPG in its unmodified manufactured state. It has also been discovered that the factors increasing these effects are strongly dependent upon the length of the ceramic-applying reaction. The use of these is also within the scope of the present invention. The present invention is markedly useful in improving the functionality of a nanoporous metal structure, and can be used to develop a highly economical electrode material for an ultra-high performance SC device. The present invention can similarly be used to develop an electrode material for an ultra-long life LIB.
[0116] In the present invention, the surface of the framework (interpore walls, ligaments) of an NPG skeleton is thus plated with a ceramic layer (thin layer), forming a nanoporous core/ceramic composite structure, which can be used to further improve the functionality, such as the pseudocapacitative ability, of the ceramic. The present invention shows that a composite hybrid structure featuring a core of nanoporous gold (NPG) that has open, bicontinuous holes and is porous, and a ceramic applied to the surface (including the interior surfaces of the tunnels) thereof can be manufactured using a liquid phase deposition method. The ceramic layer, the amount of which deposited can be controlled, can be deposited upon the surfaces of the walls present in the spaces within the NPG. The NPG is used as a template and self-supporting substrate. The formed nanoporous metal/ceramic composited exhibits dramatically superior SC effects. The present invention can be used to develop a metal/ceramic composite nanostructure taking advantage of the structure of three-dimensionally porous metal or a highly economical SC material for ultra-high performance devices.
[0117] In accordance with another embodiment of the present invention, a ceramic MnO 2 @nanoporous gold composite constituting a three-dimensional structure can be provided, the MnO 2 @nanoporous gold composite exhibiting dramatically superior electrical properties and being useful. Specifically, a nanoporous gold-MnO 2 (NPG/MnO 2 ) composite of a hybrid material can be manufactured using a simple liquid phase deposition method. The ceramic MnO 2 can be deposited on the surfaces of the gold atoms in the interpore walls of the NPG acting as the template. The composite nanostructure having the MnO 2 deposit exhibits superior energy density and power density in an SC device, and demonstrates cycle stability.
[0118] In the present invention, nanoporous gold produced by selectively etching a binary gold/silver alloy is used as a nanoporous template for manufacturing a nanoporous gold-MnO 2 (NPG/MnO 2 ) composite. Because the interior surfaces of the NPG are modified using MnO 2 , a template method involving an electroless plating (chemical plating) method, can be developed using the present invention, and used to manufacture an NPG/MnO 2 composite having a nanoporous metal skeleton/ceramic deposit composite structure. The NPG is used then as a template and self-supporting substrate. The properties of the nanoporous gold-MnO 2 (NPG/MnO 2 ) composite arise from its unique core/shell structure. In this way, the inventors have succeeded in manufacturing a ceramic composite nanostructure deposited among the skeleton of a nanoporous metal having a plurality of open, bicontinuous holes using a template method involving a liquid phase deposition reaction. The novel NPG/MnO 2 electrode of the present invention exhibits superior performance in a high-performance SC device.
[0119] In the present invention, a novel nanoporous gold (NPG)/ceramic hybrid film is provided that is useful as an electrode material for a high-performance supercapacitor (SC). In particular, a nanoporous Au (NPG)/MnO 2 hybrid film is useful as an electrode material for a high-performance supercapacitor (SC) device. In the hybrid film according to the present invention, the highly electroconductive and nanoporous NPG of the skeleton improves and promotes electron transport and ion diffusion into the MnO 2 , and functions as an electrical double-layer capacitor.
[0120] In the present invention, an NPG/SnO 2 nanocomposite in which three-dimensional nanoporous gold (3D NPG) is used as a carrier and the ceramic SnO 2 is deposited (or precipitated) onto the skeleton of the carrier is provided. The 3D NPG/SnO 2 nanocomposite can be manufactured by dealloying an alloy, and subsequently performing an electroless plating treatment. Upon testing the NPG/SnO 2 nanocomposite as an electrode for a lithium-ion battery (LIB), the special Sn (or SnO 2 ) structure of the nanocomposite was found to effectively enable large changes in volume between cycle treatments in the lithium-ion battery, yielding more superior capacity maintenance. The electrode exhibited a high reversible capacity of 620 mAh/g after 140 cycles at 0.1 C. A high capacity of 260 mAh/g was obtained even at a rate of 8 C. In this way, the three-dimensional nanoporous metal/ceramic composite according to the present invention is extremely promising as an anode material of high storage ability for a lithium battery. In a lithium-ion secondary cell in which the three-dimensional nanoporous metal/ceramic composite is used as an electrode, the problem of changes in volume can be solved, the problem of reduced capacity can be improved, and a long cycle life can be obtained.
[0121] The present invention will be described in detail hereafter with reference to examples, but these examples are offered merely for the purposes of describing the present invention and as reference for specific embodiments thereof. The examples describe specific concrete embodiments of the present invention, but do not limit or restrict the scope of the invention disclosed herein. In the present invention, it is to be understood that various embodiments are possible based on the concepts set forth in the specification.
[0122] Except where otherwise stated, all examples were or could be implemented using the standard art known to and commonly used by a person skilled in the art.
EXAMPLE 1
Synthesis of Substrate and Nanoporous Gold (NPG) as Template
[0123] A thin foil of Ag 65 Au 35 (subscript numbers indicate atomic ratio) acting as a precursor substance (Ag 65 Au 35 foil, size up to 20 mm×20 mm×100 nm) was manufactured by repeated the hammering process. The Ag 65 Au 35 foil was selected etched at room temperature for 8 hours in a 70% nitric acid (HNO 3 ) aqueous solution to manufacture nanoporous gold (NPG). The dealloyed NPG sample was rinsed at least five times in purified water (18.2 MΩ·cm) to remove the remaining chemical substances. Regarding nanoporous gold, see Fujita, T.; Okada, H.; Koyama, K.; Watanabe, K.; Maekawa, S.; Chen, M. W., “Unusually small electrical resistance of three-dimensional nanoporous gold in external magnetic fields”, Phys. Rev. Lett. 101, 166601 (2008); and Erlebacher, J.; Aziz, M. J.; Karma, A.; Dimitrov, N.; Sieradzki, K., “Evolution of nanoporosity in dealloying”, Nature 410, 450-453 (2001).
Structure of NPG/MnO 2 Nanocomposite
[0124] The ceramic MnO 2 was formed covering the interpore walls (ligaments) of the NPG. Thus, the interior surfaces of the 3D NPG were modified (chemically plated) using a wet ceramic formation technique. A 0.1 mM KMnO 4 aqueous solution (pH=9-10) was used as the wet-method chemical solution used to form the ceramic MnO 2 , the as-synthesized NPG film was immersed in the aqueous solution while being magnetically stirred, a reductant was added thereto, and treatment was performed at room temperature for 5 minutes, 10 minutes, and 20 minutes to obtain NPG/MnO 2 nanocomposite films. Hydrazine (NH 2 NH 2 ) gas was used as the reductant.
Analysis of Microstructural Characteristics
[0125] The microstructure and chemical composition characteristics of the as-synthesized NPG and NPG/MnO 2 composite were analyzed using a field emission scanning electron microscope (SEM; JEOL JSM-7001 F, 15 keV) equipped with an Oxford X-ray energy dispersive spectroscope (EDS) and a Cs-corrected transmission electron microscope (TEM; JEOL 2100 F, 200 keV).
[0126] The as-synthesized NPG and porous NPG/MnO 2 nanocomposite were placed upon holey carbon TEM grids for TEM analysis.
Construction of Supercapacitor Device
[0127] A supercapacitor device was constructed as follows.
[0128] A polyethylene (PE) film (membrane; approx. 40 μm thick) coated using a 50 nm-thick gold film (thin film) was used as a conductive plate. Clean, as-synthesized NPG and a porous NPG/MnO 2 nanocomposite film were applied upon the PE film as an electrode and a current collector.
[0129] Two sheets of dealloyed bare NPG or two sheets of NPG/MnO 2 composite were disposed with a piece of cotton paper (about 40 μm thick, Bemliese) sandwiched therebetween as a separator. The overall thickness of the supercapacitor (SC) device was about 120 μm.
Analysis of Electrochemical Properties of NPG/MnO 2 Composite
[0130] All electrochemical measurements were taken using two typical IviumStat electrochemical analyzers (Ivium Technologies) of an IviumStat electrochemical workstation (Ivium Technologies) constituting an potentiostat/galvanostat manufactured by Ivium Technologies in the Netherlands at room temperature. A charging/discharging test was performed in cyclic voltammetry (CV) and galvanostatic modes in order to investigate the electrochemical activity of the SC device.
[0131] CV measurement was performed at different scanning speeds at electrical potentials in a range from 0 to 0.8 V. The charging/discharging process performed by the galvanostat was performed at repeated cycles at different current densities and electrical potentials from 0 to 0.83 V in a 2M Li 2 SO 4 aqueous solution. Cycle stability over more than 1,000 cycles was checked via a charging/discharging test in galvanostatic mode at a current density of 1 A/g.
Results and Analysis
Nanoporous Structure of Nanoporous Gold/Ceramic Composite
[0132] A 100 nm-thick Au/MnO 2 composite film constituting a nanoporous gold/ceramic composite was manufactured according to the two-step process conceptually illustrated in FIG. 1 a , namely, by dealloying an Ag—Au alloy using nitric acid to produce electroconductive nanoporous gold, followed by precipitating (plating) nanocrystalline MnO 2 constituting within the nanoporous channels (reticulated passages or nanoporous conduits) thereof.
[0133] The dealloyed bare NPG exhibited nanopore channels having a characteristic length of about 40 nm and a porous structure of bicontinuous holes constituted by quasi-periodic gold ligaments ( FIG. 1 b ) in a typical scanning electron microscope (SEM) image. The nanocrystalline MnO 2 was observed to be uniformly plated within the nanopore channels of the NPG ( FIG. 1 c ). Adjusting plating treatment time allowed the amount of MnO 2 deposited to be controlled. This was confirmed using energy dispersive X-ray spectroscopy (EDS) to perform chemical analysis of the Au/MnO 2 composite ( FIG. 5 ).
[0134] A transmission electron microscope (TEM) image of an Au/MnO 2 composite film obtained using a 20-minute plating treatment showed that the nanoporous channels ( FIG. 1 d ) were filled with about 5 nm-diameter nanocrystals of MnO 2 ( FIG. 1 e ). As shown by high-resolution TEM images ( FIGS. 6 and 1 e ) of MnO 2 grown for five minutes and 20 minutes, respectively, the interface structure showed good contact between the nanocrystalline MnO 2 and the gold ligaments, thereby imparting the hybrid system as a whole with superior electrical conductivity ( FIG. 7 ).
Electrochemical Properties of Nanoporous Gold/Ceramic Composite
[0135] The electrochemical properties of the nanoporous Au/MnO 2 composite film were tested and investigated using an active charge storage electrode a simplified device configuration ( FIG. 8 ) using two sheets of thin Au/MnO 2 composite film as electrodes, a piece of cotton paper as a separator, and a 2M Li 2 SO 4 aqueous solution as an electrolyte. The overall thickness of the SC device was about 120 μm. FIG. 2 a shows a typical cyclic voltammetry (CV) image at a scan speed of 50 mV/s of the supercapacitor (SC), in which, in the two-electrode structure, a dealloyed bare NPG film and a nanoporous Au/MnO 2 composite film were used as electrodes. FIG. 2 a shows that, in the case of the nanoporous Au/MnO 2 composite, the MnO 2 nanoparticles engaged in a rapid, reversible, continuous surface redox reduction, thereby yielding a perfect, symmetrical rectangular shape. The lack of a redox peak shows that the SC performed charging and discharging at a roughly constant speed in all voltammetric cycles. The current density per unit of weight of the nanoporous Au/MnO 2 composite was considerably greater than that of the SC assembled using the dealloyed bare NPG film as an electrode, and, when the plating treatment time was increase to increase the amount of pseudocapacitative MnO 2 , there was an increase in capacitance as plating treatment time increased ( FIG. 2 b ). Thus, the capacitor performance of an NPG/MnO 2 SC is strongly dependent upon the amount of MnO 2 deposited, and can be dramatically improved by taking on a pseudocapacitative substance. This can be confirmed by a typical linear voltage/time profile of the SC charging and discharging at a current density of 0.5 A/g ( FIG. 2 c ). The discharge time increased dramatically as the MnO 2 plating time was increased, suggesting that increased MnO 2 plating leads to the ability to store greater amounts of electricity.
[0136] FIG. 2 d shows the specific capacitance (Cs) of an NPG/MnO 2 SC as a function of applied current density. Cs is calculated from a discharge curve according to the following formula 1, and i is the applied current.
[0000] C s =t /[−(Δ V/Δt ) m] {Formula 1}
[0137] The following formula 2 shows the slope of the discharge curve after the drop in voltage at the beginning of each discharge, and m is the mass of the NPG or NPG/MnO 2 on one electrode.
[0000] −ΔV/Δt {Formula 2}
[0138] The specific capacitance of the NPG/MnO 2 at different currents far exceeded the specific capacitance of the dealloyed bare NPG SC, and longer MnO 2 plating treatments yielded greater specific capacitance. Although gold is a heavy element, an NPG/MnO 2 electrode plated with MnO 2 for 20 minutes yielded a high specific capacitance of about 601 F/g (based on the combined mass of NPG and MnO 2 ). This value was considerably higher than the about 385.4 F/g shown by an MnO 2 /carbon nanotube (CNT; Zhou, Y. K.; He, B. L.; Zhang, F. B.; Li, H. L. Hydrous manganese oxide/carbon nanotube composite electrodes for electrochemical capacitors. J. Solid State Electrochem. 8, 482-487 (2004)), the about 210 F/g shown by MnO 2 /poly(3,4-ethylenedioxythiophene) (PEDOT; Liu, R. et al., J. Am. Chem. Soc. 130, 2942-2943 (2008)), the about 415 F/g shown by MnO 2 /polyaniline (Chen, L. et al., J. Power Sources 195, 3742-3747 (2010)), and the about 427 F/g shown by a MnO 2 /CNT/PEDOT-poly(styrene sulfonate) ternary composite (Hou, Y.; Cheng, Y. W.; Hobson, T.; Liu J. Design and synthesis of hierarchical MnO 2 nanospheres/carbon nanotubes/conducting polymer ternary composite for high performance electrochemical electrodes. Nano Lett. 10, 2727-2733 (2010)). As current density increased from 0.5 A/g to 20 A/g, the specific capacitance decreases to about 170 F/g and stayed at that value. The value was still comparable to that of MnO 2 /CNT, or of an electroconductive polymer hybrid electrode at high current density.
[0139] The effects of scan speed upon the CV responsiveness of the NPG/MnO 2 electrode were investigated over a range from 10 to 100 mV/s, as shown in FIG. 3 a and FIG. 9 . It can be observed from FIG. 3 a and FIG. 9 that current increased as scanning speed increased for all electrodes. No attention-worthy change in the shape of the CV curve was discovered even at high scanning speeds. An NPG/MnO 2 electrode plated for 20 minutes exhibited an extremely high volumetric capacitance of about 1,160 F/cm 3 at a scanning speed of 50 mV/s, a value far higher than the values hitherto reported: 246 F/cm 3 at a scanning speed of 10 mV/s for a multiwall carbon nanotube (MWCNT)/MnO 2 , electrode, 156 F/cm 3 at a scanning speed of 2 mV/s for a carbon/MnO 2 electrode (Fischer, A. E.; Saunders, M. P.; Pettigrew, K. A.; Rolison, D. R.; Long, J. W. Electroless deposition of nanoscale MnO 2 on ultraporous carbon nanoarchitectures: correlation of evolving pore-solid structure and electrochemical performance. J. Electrochem. Soc. 155, A246-A252 (2008)), and 132 F/cm 3 at a scanning speed of 50 mV/s for an MWCNT electrode (Lee, S. W.; Kim, B. S.; Chen, S.; Shao-Horn, Y.; Hammond, P. T. Layer-by-layer assembly of all carbon nanotube ultrathin films for electrochemical applications. J. Am. Chem. Soc. 131, 671-679 (2009)).
[0140] In order to rate the effects of MnO 2 upon the electrochemical performance of the NPG/MnO 2 electrode, the charge of the skeleton of the dealloyed bare NPG was subtracted and the specific capacitance of the MnO 2 in each of the electrodes calculated according to the following formula 3.
[0000] C s,MnO2 =( Q NPG/MnO2 −Q NPG )/(Δ Vm MnO2 ) {Formula 3}
[0141] In the formula, Q NPG/MnO2 indicates the volumetric charge of the NPG/MnO 2 , Q NPG indicates the volumetric charge of the NPG electrode, ΔV indicates the width of the electrical potential window, and m MnO2 indicates the mass of deposited MnO 2 .
[0142] As shown in FIG. 3 b , the specific capacitance of the MnO 2 increased as scanning speed dropped to 100-50 mV/s, reaching a maximum value of about 1,145 F/g at a scanning speed of 50 mV/s. This value was about 83% of the theoretical value (about 1,370 F/g), the highest ever observed in an SC. This superior specific capacitance is likely due to the unique microstructure of the electrode structure, in which the nanocrystalline MnO 2 is supported by a highly electroconductive, porous gold network structure allowing for the easy and efficient access of electrons and ions.
[0143] FIG. 4 a shows a Ragone plot (power density P over energy density E) for an SC device using an NPG/MnO 2 electrode. The P and E per unit of weight were calculated as P=V 2 /(4RM) and E=0.5CV 2 /M. In the formulas, V is cutoff voltage, C is the measured capacitance of the device, M is the total mass of the NPG electrode or the total mass of the NPG/MnO 2 electrode, R=ΔV IR /(2i), and V IR is the drop in voltage between the first two points in the voltage drop at top cutoff. As shown by the plot, the specific energy and the specific power density of the NPG/MnO 2 SC both increased along with the amount of deposited MnO 2 , and a 20-minute MnO 2 plating treatment yielded the highest values at about 57 Wh/kg for energy density and about 16 kW/kg for power density. This high level of energy density far outstrips that of a commercially available device having the same power density. A comparison with other MnO 2 electrodes showed that the NPG/MnO 2 (20-minute plating treatment) electrode showed a high energy density at maximum power density, roughly 2 to 20 times those shown by the MnO 2 electrodes reported in the documents as being the best, namely, an MnO 2 electrode (3.3 Wh/kg, 3.1 kW/kg; Cottineau, T.; Toupin, M.; Delahaye, T.; Drousse, T.; Belanger, D., “Nanostructured transition metal oxides for aqueous hybrid electrochemical supercapacitors”, Appl. Phys. A 82, 599-606 (2006)), a coaxial CNT/MnO 2 and Au-CNT/MnO 2 array (2.9 Wh/kg, 11 kW/kg; 4.5 Wh/kg, 33 kW/kg; Reddy, A. L. M. et al., J. Phys. Chem. C 114, 658-663 (2010)) an activated charcoal-MnO 2 hybrid electrode (7.6 Wh/kg, 4.1 kW/kg; Brousse, T.; Toupin, M.; Belanger, D., “A hybrid activated carbon-manganese dioxide capacitor using a mild aqueous electrolyte”, J. Electrochem. Soc. 151, A614-A622 (2004); Xu, C. J.; Du, H. D.; Li, B. H.; Kang, F. Y.; Zeng, Y. Q., “Asymmetric activated carbon-manganese dioxide capacitors in mild aqueous electrolytes containing alkaline-earth cations”, J. Electrochem. Soc. 156, A435-441 (2009)), a CNT/MnO 2 composite electrode (25.2 Wh/kg, 45.4 kW/kg; Yan, J. et al., J. Power Sources 194, 1202-1207 (2009)), and a CNT in an aqueous electrolytic (8.5 Wh/kg, 74 kW/kg; Hu, L. B.; Choi, J. W.; Yang, Y.; Jeong, S.; Mantia, F. L.; Cui, L. F.; Cui, Y., “Highly conductive paper for energy-storage devices”, Proc. Natl. Acad. Sci. USA 106, 21490-21494 (2009); An, K. H.; Kim, W. S.; Park, Y. S.; Choi, Y. C.; Lee, S. M.; Chung, D. C.; Bae, D. J.; Lim, S. C.; Lee, Y. H., “Supercapacitors using single-walled carbon nanotube electrodes”, Adv. Mater. 7, 497-500 (2001)).
[0144] FIG. 4 b shows the cycle stability of the NPG/MnO 2 SC as a function of number of cycles. Specific capacitance was measured over 1,000 cycles at a constant charge/discharge current density of 1 A/g. There was a slight drop in capacitance over the first 500 cycles, after which capacitance stabilized at a level of about 85%. This shows that the hybrid material substance exhibits highly superior stability for energy storage applications. The highly superior capacitor ability of the NPG/MnO 2 SC is thought to arise from a combination of Faradaic and non-Faradaic processes. MnO 2 normally has low electroconductivity, which limits its charge/discharge speed, but the charge transfer reaction-type pseudocapacitance of the NPG/MnO 2 electrode can be enhanced due to the swift ion diffusion of the three-dimensional nanoporous architecture and the high electrical conductivity of the NPG skeleton. Moreover, the NPG core of the porosity hybrid composite is believed to function as a double-layer capacitor, yielding compound mechanisms for energy storage, and acting as a capacitor having extremely improved reversibility.
EXAMPLE 2
Structure of NPG/SnO 2 Nanocomposite
[0145] An Ag 63 Au 35 (subscript numbers indicate atomic %) was selectively etched at room temperature for nine hours in a 70% nitric acid (HNO 3 ) aqueous solution to produce a roughly 100 nm-thick three-dimensional nanoporous gold (3D NPG) film. The dealloyed NPG sample was rinsed in purified water (18.2 MΩ·cm) to thoroughly remove any chemical substances remaining in the nanoporous channels. Electron microscope SEM observation showed that the gold thin film had a quasi-periodic porous structure of bicontinuous channels (tunnel passages) having gold ligaments (interpore walls or ligaments) having a characteristic length of roughly 50 nm. Using electroless plating, tin nanoparticles were adhered (plating treatment) upon the 3D NPG at room temperature for 12 hours using an 0.5M SnCl 2 aqueous solution (pH=2). Hydrazine (NH 2 NH 2 ) gas was used as the reductant. The obtained film was rinsed with purified water to remove any remaining chemical substances.
[0146] The microstructural and chemical composition properties of the obtained NPG/SnO 2 composite were investigated in a manner similar to that used for example 1. Specifically, the shape of the surface was investigated using a field emission scanning electron microscope (SEM; JEOL 6300F, 15 keV). High-resolution transmission electron microscopy (HTEM) was performed using a transmission electron microscope (TEM; JEOL 2010F, 200 keV). The interpretable resolution defined by the contrast transfer function (CTF) of the objective lens was 0.19 nm. X-ray energy dispersive spectroscopy (EDX) was performed using a JEOL 2010F Oxford system.
Analysis of Electrochemical Properties of NPG/SnO 2 Composite
[0147] A lithium-ion battery was constructed as follows.
[0148] A composite (3D nanoporous Au-supported SnO 2 composite: 3D NPG/SnO 2 nanocomposite) in which tin (immediately oxidized after formation to form SnO 2 ) is deposited upon a gold skeleton using three-dimensional nanoporous gold (3D NPG) as a carrier was used as an electrode for an electrochemical Sn/Li battery, and 1M LiPF 6 in a liquid comprising ethylene carbonate (EC) and diethyl carbonate (DEC) (EC:DEC=1:1, v/v) was used as an electrolyte.
[0149] The battery was assembled within an argon-filled glove box (MBRAUN LABMASTER 130) with humidity and oxygen concentration levels kept at 1 ppm or less. A cycle treatment was performed upon the battery in a voltage range of 1.0 V to 0.005 V using an Arbin MSTAT battery tester system.
Results and Analysis
Nanoporous Structure of Nanoporous Gold/Ceramic Composite
[0150] FIG. 11 a shows the schematic structure of a three-dimensionally nanoporous gold substrate (3D nanoporous Au: 3D NPG) prepared by chemically dealloying an Ag 65 Au 35 (at. %) foil. Dealloying was performed by treating the foil in a 70% HNO 3 aqueous solution at room temperature for nine hours. FIG. 11 c shows a typical scanning electron microscopy (SEM) image of dealloyed bare 3D NPG. SEM observation showed that the gold thin film had a quasi-periodic porous structure of bicontinuous channels (tunnel passages) having gold ligaments (interpore walls or ligaments) having a characteristic length of 50 nm. Reference document: Y. Ding, M. Chen, MRS Bulletin, 2009, 34, 569.
[0151] A 3D NPG/Sn composite film constituting a nanoporous gold-tin composite was produced by precipitating (plating) nanocrystalline tin in the nanoporous channels (reticulated passages or nanoporous conduits) of nanoporous gold (3D NPG) obtained by dealloying an Ag—Au alloy using nitric acid.
[0152] The tin of the composite underwent oxidation and changed into ceramic nanocrystalline SnO 2 . The ceramic nanocrystalline SnO 2 was thereby precipitated (plated), producing a 100 nm-thick 3D NPG/SnO 2 composite film constituting a nanoporous gold/ceramic composite. The plating of the crystalline tin was performed using a modified electroless method for 12 hours at room temperature in a 0.5 M SnCl 2 aqueous solution (pH=2), using hydrazine (N 2 H 4 ) as a reductant. FIG. 11 d shows typical scanning electron microscopy (SEM) images showing the microstructure of the 3D nanoporous gold composite obtained via dealloying and the subsequent electroless plating treatment.
[0153] FIG. 15 shows the results of EDX analysis of the 3D NPG/SnO 2 composite. As is apparent from FIG. 15 , the Au/SnO 2 composite contains roughly 20 wt % gold and roughly 80 wt % tin.
[0154] FIG. 12 shows the typical microstructure of the as-manufactured 3D nanoporous gold-nanocrystalline tin composite. FIG. 12 a shows an SEM image of tin (or SnO 2 ) supported by as-manufactured gold, illustrating the bicontinuous nanoporous structure. FIG. 12 b shows a magnified cross-sectional image showing a network (reticulated structure) in which relatively uniform and large holes having diameters of roughly 100±50 nm are evenly distributed. The image also shows the thickness of the walls of the holes as being in a range from 20 nm to 50 nm. FIG. 12 c shows a transmission electron microscopy (TEM) image thereof, and FIG. 12 d shows a high-resolution transmission electron microscopy (HTEM) image. The images confirm that the deposited tin particles (or SnO 2 particles) have a single-crystalline shape. This is also shown in the selected-area electron diffraction (SARD) pattern shown in inset in FIG. 12 c . The pattern was obtained in a broad range along orientation <110>. The ring-shaped SAED pattern confirms that the overall structure of the SnO 2 is polycrystalline. As can be measured from the HTEM image ( FIG. 12 d ), the individual grains had sizes of from 3 to 6 nm.
Electrochemical Properties of 3D Nanoporous Gold/Ceramic Composite
[0155] When an electrochemical charging/discharging (dealloying/alloying) test was performed using the plated 3D nanoporous gold composite (3D NPG/SnO 2 nanocomposite) as an electrode, a high reversible capacity of 515 mAh/g was demonstrated in a voltage range from 0.1 to 1.0 V at a rate of 1 C (1000 mA/g). The measured charge capacity retention rate after 100 cycles was 90% of the initial value. The distinctive bidirectional carrier structure of the three-dimensional nanoporous gold (3D NPG) plays a key role in its electrochemical performance. Specifically, (i) it is possible to increase the electrode/electrolyte contact area, (ii) swift transfer of Li + and e − is made possible, and (iii) the three-dimensional structure provides suitable empty spaces, allowing large volume changes between charging and discharging to be adjusted, in turn allowing electrical insulation after extended cycle treatments to be prevented.
[0156] FIG. 13 a shows the voltage behavior of a battery using the 3D nanoporous gold composite (a 3D NPG-supported tin (or SnO 2 ) lithium battery). Specifically, the figure shows voltage behavior at a rate of C/10 (discharging theoretical capacity for 10 hours). The figures indicate that the electrode has the characteristics of a typical tin electrode (or a SnO 2 electrode). In the initial discharge and charge step, respective specific capacities of 756 mAh/g and 624 mAh/g were produced, equivalent to 82% coulombic efficiency. During the initial discharge step, a thick solid-electrolyte interphase (SEI) was formed on the surface of the electrode, which is thought to result in the large losses in initial capacity of the tin electrode (H. Qiao, Z. Zheng, L. Zhang, L. Xiao, J. Mater. Sci. 2008, 43,2778: Y. W. Xiao, J. Y. Lee, A. S. Yu, Z. L. Liu, J. Electrochem. Soc. 1999, 146, 3623). FIG. 13 b shows the discharge capacity of the 3D NPG-supported SnO 2 as a function of discharge rate (1 C to 10 C). Discharge capacity was 515 mAh/g at 1 C, 470 mAh/g at 3 C, 380 mAh/g at 5 C, and 210 mAh/g at 10 C. FIG. 13 c shows the capacity-maintaining ability of the 3D NPG-supported SnO 2 at a rate of 0.5 C. A reversible capacity of about 599 mAh/g was clearly maintained even after 140 cycles, equivalent to 95.9% of the initial charge capacity. The better efficiency of the 3D NPG-supported SnO 2 compared to Sn nanoparticles (about 79% coulombic efficiency: Lee, K. T.; Jung, Y. S.; Oh, S. M. J. Am. Chem. Soc. 2003, 125, 5652-5653) may be related to the distinctive structure offering the advantages described above.
[0157] FIG. 14 a shows an SEM image of the electrode according to the present invention after 140 cycles at a rate of about 0.5 C and a range of 0.005 to 1.0 V. It can clearly be seen that the three-dimensionally nanoporous structure of the SnO 2 remains effectively intact during cycle treatment. Small changes in structure may lead to gradually reductions in capacity, as shown in FIG. 14 b . In FIG. 14 a , average pore diameter appears to have decreased with respect to the 3D NPG-supported SnO 2 composite as plated and deposited due to remaining organic electrolyte or related substances. In addition, the 3D nanoporous gold/ceramic composite according to the present invention exhibits highly superior rate performance due to the small-sized SnO 2 particles. As shown in FIG. 14 b , capacity was 515 mAh/g when a cycle treatment was initially performed at 1 C, 420 mAh/g in a cycle treatment at 4 C, 330 mAh/g in a cycle treatment of 6C, and 260 mAh/g in a cycle treatment at 8 C.
INDUSTRIAL APPLICABILITY
[0158] Using the present invention, a nanoporous ceramic composite metal (specifically, a nanoporous metal core/ceramic deposit composite) having superior electrical properties can be obtained, allowing these superior properties to be utilized in a variety of applications in combination with electrical/electronic devices such as dielectrics, SC electrodes, lithium-ion batteries (LIBs), LIB electrodes, energy storage devices, backup power sources for portable phones and personal computers, backup power sources for electronic control devices for automobiles, and power storage devices.
[0159] It is clear that the present invention can be implemented other than as set forth in the foregoing description and examples. Various modifications and alterations of the present invention are possible in the light of the foregoing teachings, and these are thus also encompassed within the scope of the appended claims. | Since pseudo-capacitance transition metal oxides (for example, MnO 2 ) have high theoretical capacitance and are eco-friendly, inexpensive, and abundant in the natural world, pseudo-capacitance transition metal oxides are gaining attention as promising capacitor electrode materials. However, pseudo-capacitance transition metal oxides have relatively low electronic conductivity and limited charging and discharging rates, and a it is therefore difficult to use pseudo capacitance transition metal oxides for high output power applications. If a plating process accompanying a liquid-phase precipitation reaction is performed on a nanoporous metal such as nanoporous gold (NPG) to deposit a ceramic material (for example, MnO 2 or SnO 2 ) on the surface of a core metal (for example, NPG), a nanoporous metal-ceramic composite having particular structural characteristics and comprising a metal core part and a ceramic deposition part can be obtained. This hybrid material is a good functional material and exhibits excellent functions when used as an electrode material for high-performance super capacitor (SC) devices or as an electrode material for LIB. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to pollutant abatement and, in particular, to an apparatus and process for eliminating and burning out pollutants in the interior air of large volume in an isolated space such as buildings, public transportation systems, and military vehicles contaminated by chemical and biological warfare agents. The chemical and biological warfare contaminants are eliminated by their exposure to the flames of the microwave plasma torches.
BACKGROUND OF THE INVENTION
[0002] Protection of people against chemical and biological warfare agents is very important and is very necessary in the present world environment. The threat of chemical and biological warfare agents increases in a domestic terrorist attack and in worldwide military conflict. Year 2001 anthrax problems throughout the USA after 9-11 terror attack, 1995 sarin nerve gas attack on a Tokyo subway station, and the threat of toxic agents in 1991 Gulf War are a few examples of the worldwide threat of chemical and biological warfare agents. There are several categories of chemical warfare agents. They are (1) Nerve Warfare Agents, (a) Tabun, GA: CH 3 ) 2 N—P(═O)(—CN)(—OC 2 H 5 , (b) Sarin, GB: CH 3 —P(═O)(—F)(—OCH(CH 3 ) 2 , (c) Soman, GD: CH 3 —P(═O)(—F)(—CH(CH 3 )C(CH 3 ) 3 , (d) Cyclohexyl methylphosphonofluoridate, GF: CH 3 —P(═O)(—F)(cyklo-C 6 H 11 ), (e) Methylphosphonothioic acid S-(2-(bis(1-methylethyl)amino)ethyl) O-ethyl ester, VX: CH 3 —P(═O)(—SCH 2 CH 2 N[CH(CH 3 ) 2 ] 2 )(—OC 2 H 5 ), (f) GE: Phosphonofluoridic acid, ethyl-, isopropyl ester, (g) VE: Phosphonothioic acid, ethyl-, S-(2-(diethylamino)ethyl) O-ethyl ester, (h) VG: Amiton, and (i) VM: Phosphonothioic acid, methyl-, S-(2-(diethylamino)ethyl) O-ethyl ester, (2) Blister and Vesicant Warfare Agents, (a) Lewisite (L), (b) Mustard-Lewisite (HL), (c) Nitrogen Mustards (HN-1, HN-2, HN-3), (d) Phosgene Oxime (CX), and (e) Sulfur Mustards (H, HD, HT), (3) Blood Warfare Agents, (a) Cyanogen Chloride (CK), and (b) Hydrogen Cyanide (AC), and (4) Pulmonary Warfare Agents, (a) Chlorine, (b) Chloropicrin (PS), (c) Diphosgene (DP), (d) Phosgene (CG). There are also several biological warfare agents such as Anthrax, Botulinum Toxins, Brucellosis, Cholera, Clostridium Perfringens Toxins, Congo-Crimean Hemorrhagic Fever, Ebola Haemorrhagic Fever, Meioidosis, Plague, Q Fever, Ricin, Rift Valley Fever, Saxitoxin, Smallpox, Staphylococcal Enterotoxin B, Trichothecene Mycotoxin, Tularemia, Venezuelan Equine Encephalitis. There may be other chemical and biological warfare agents not listed above. But, those warfare agents must be also eliminated by the present invention.
[0003] The purpose of the present invention is a rapid and effective elimination of toxic substances in the interior air in an isolated space such as buildings, public transportation systems, and military vehicles. The buildings, where the interior air must be purified, can be the personal dwellings, apartment buildings, office buildings, school buildings, government buildings, and the commercial buildings. The public transportation system includes automobiles, cars, buses, trains, ships, commercial airline airplanes, and the subway railroad system. The military vehicles mentioned are military trucks, armored personnel carriers, military buses, tanks, military ships, airplane carries, helicopters, and military airplanes. The toxic warfare agents mentioned above have been traditionally incinerated by burn scrubbers. These burners tend to be large, inefficient, and expensive. On the other hand, the microwave plasma torch operated at the atmospheric pressure is compact enough to be installed in a narrow space and is effective to eliminate the toxic agents diluted in a large flow rate of air.
[0004] Pollution control with respect to contaminated air as a carrier gas was proposed in U.S. Pat. No. 5,468,356 issued to Uhm, one of the present inventors, on Nov. 21, 1995. In that invention, contaminated air is exposed to microwave-generated plasma for oxidation by atomic oxygen without bulk heating within a simple cylindrical waveguide cavity at the room temperature. Further, such plasma is generated within the cavity by introduction of high-power microwave radiation passing through a weak electric field to achieve air purification despite low electron energy. Pollution control with respect to contaminated air as a hot carrier gas was proposed in U.S. Pat. No. 5,830,328 issued to Uhm, one of the present inventors, on Nov. 3, 1998. The plasma generated in a hot gas like discharge gas from a combustion engine or like the discharge gas from an incinerator may oxidize the contaminants, purifying the discharge air. The present invention is a combination of the above two inventions, making use of an intense electric field in the microwave radiations and use of the hot air in the torch flames of the present invention.
[0005] It is therefore an important object of the present invention to enhance the electric field strength of the microwave radiation in order to achieve elimination of toxic warfare agents in a carrier gas by exposure to a plasma torch generated by concentration of the microwave on a small spot.
[0006] Other object of the present invention is to simultaneously provide an elimination and burnout system that is effective against a wide range of chemical and biological warfare agents with several plasma torches connected in series.
[0007] Another object is to overcome difficulties heretofore experienced in achieving efficient and rapid elimination of the toxic agents by oxidation with several plasma torches connected in series.
[0008] Additional objects, advantages and novel features of the invention will be explained in part in the following description, and will be apparent to those skilled in the following experiment.
SUMMARY OF THE INVENTION
[0009] The present invention is the apparatus for simultaneous elimination and burnout of chemical and biological warfare agents diluted in air with several microwave plasma torches connected in series. Particularly, the apparatus is useful for purifying the interior air of large volume in an isolated space such as buildings, commercial transportation systems, and military vehicles contaminated with chemical and biological warfare agents. High electric field strength and high-energy electrons provided by the plasma torch are needed to eliminate and burn out chemical and biological warfare agents. The microwave plasma torches are connected in series so that the contaminant air stream to be purified passes sequentially from one plasma torch to the next, thereby increasing the required residence time for optimum effect. The high temperature flames of microwave plasma torches create a unique environment for efficient chemical reactions. Prolonging this unique environmental condition by sequential connection of optimum number of microwave plasma torches is critically important for rapid purification of a large volume of contaminated air, creating a synergic effect caused by multiple plasma torches. The number of the plasma torches is empirically determined.
[0010] The present invention is made of the magnetrons used in home microwave ovens. These magnetrons are inexpensive, commercially available and compact. They are operated at a frequency of 2.45 GHz and their power is in the range of 0.6˜1.4 kW. The microwave intensity with a frequency of 2.45 GHz from a magnetron is highest at the discharge tube. These intense microwaves at the discharge tube induce an intense electric field, initiating electrical breakdown in the carrier gas containing chemical and biological warfare agents. The plasma torch generated by the electrical breakdown due to the microwave electric field eliminates and burns out chemical and biological warfare agents by oxidation, by molecular breakdown, and by hot gases. The atmospheric plasma abatement system, which is simple and cost-effective, is the most suitable for purification of air contaminants. The elimination experiment of any chemical warfare agent is almost impossible in an ordinary laboratory due to safety issues. In this context, the experimentalists traditionally carry out a simulated experiment by making use of toluene gas. Elimination efficiency of toluene as one simulated agent was experimentally measured by a gas chromatography system. For same reason, the biological warfare agents are not used in an ordinary laboratory. Therefore, the vitrification and burnout of dried and pulverized sewage sludge powder as the biological simulated agent were carried out.
BRIEF DESCRIPTION OF DRAWING FIGURES
[0011] A more complete appreciation of the invention and many of its attendant advantages will be aided by reference to the following detailed description in connection with the accompanying drawings:
[0012] [0012]FIG. 1 is a block diagram illustrating the airborne warfare agent elimination system of the present invention;
[0013] [0013]FIG. 2 is a cross-sectional view of the three microwave plasma torches connected in series;
[0014] [0014]FIG. 3 is the transmittance of the toluene gas measured by the Gas Chromatography (GC) before and after the microwave discharges.
DETAILED DESCRIPTION
[0015] The present invention is the apparatus and scheme for a simultaneous elimination and burnout of chemical and biological warfare agents diluted in air with several microwave plasma torches connected in series. The principles and operation of modular microwave plasma torches of the present invention are described according to the drawings.
[0016] Referring now to the drawing in details, FIG. 1 diagrams the basic portion 10 of the present invention wherein air stream contaminated with chemical and biological warfare agents as input gas 16 enters the discharge tube 12 made of an insulating dielectric material such as quartz or ceramics. According to the experimental results with various quartz size, it was found that the most suitable plasma generation accomplished when the inner diameter of the quartz tube with thickness 1.5 mm is in the range of 22˜27 mm for the microwave frequency of 2.45 GHz. Diameter of a typical plasma-torch flame is about 20 mm. The flame size does not increase even if the internal diameter of the quartz tube increases.
[0017] The power supply 24 , consisted of full-wave voltage double circuit, provides the electrical power to the magnetron 22 which generates the microwave radiation and which is cooled by a cooling system 26 , which must be capable of delivering at least 1000 liters per minute (l/min) cooling air. The magnetron 22 must be sufficiently cooled, because the magnetron efficiency is very sensitive to the temperature. The generated microwave radiation from the magnetron 22 is guided through the waveguide 18 - c , passes through the three-stub tuning device 20 , and enters the discharge tube 12 through the waveguide 18 - b . The magnetron 22 in the present invention is the low-power 2.45 GHz microwave source used in a typical home microwave oven. Some of the microwave radiation in the discharge tube 12 goes forward to the end of the waveguide 18 - a and is reflected back to the discharge tube 12 . The electric field induced by the microwave radiation in the discharge tube 12 can be maximized by adjusting the three-stub tuning device 20 . The ignition device 14 with its terminal electrodes inside the discharge tube 12 is fired to initiate plasma generation inside the discharge tube 12 . The plasma torch in discharge tube 12 is ignited by the combined action of the ignition device 14 and the electrical power provided by the microwave radiation.
[0018] The torch flame in the discharge tube 12 is stabilized by the swirl gas input 30 . The swirl gas enters the discharge tube sideways creating a vortex inside the discharge tube, stabilizing the torch flame and protecting the discharge tube wall, made of quartz tube, from heat emitted by the flame of temperature with 5,000 degrees Celsius. The swirl gas 30 plays important roles in the thermal insulation of the discharge tube 12 and in the stabilization of the plasma torch flame. Compressed air or contaminated air may be injected as a swirl gas 30 . The output gas 28 is exhausted through the torch exit 32 .
[0019] A cross-sectional view of three microwave plasma torches connected in series 100 is presented in FIG. 2. The apparatus 100 consists of three microwave plasma torches 100 a , 100 b and 100 c connected in series. Each microwave plasma torch is connected with cylindrical tubes 54 a and 54 b , which are made of brass or stainless steel. The power supplies 24 a , 24 b and 24 c , consisted of full-wave voltage double circuit as explained in FIG. 1, provide the electrical power to the magnetrons 22 a , 22 b and 22 c , which generate the microwave radiations and which are cooled by each cooling system 26 a , 26 b and 26 c . The generated microwave radiations are guided through the tapered waveguides 180 a , 180 b and 180 c , which deliver effectively the microwave energies into the discharge tubes 12 a , 12 b and 12 c . The ignition devices 14 a , 14 b and 14 c attached to each microwave plasma torch 100 a , 100 b and 100 c are fired to initiate plasma generation inside the discharge tubes 12 a , 12 b and 12 c . The quartz holders 40 a , 40 b and 40 c made of brass or stainless steel hold the discharge tubes 12 a , 12 b and 12 c . A cylindrical tube 42 a is set up on the bottom of the quartz holder 40 a to transfer contaminated gas stream 16 sucked up by a blower fan 80 into the plasma torches 100 a , 100 b and 100 c in turn. The blower fan 80 unit may act like a vacuum cleaner, even swiping surfaces and collecting contaminants settled on surfaces, if the tube 42 a is made of a flexible material. The flow direction of gas stream 16 is represented by arrows 90 . The plasma torches are connected in series, so that gas stream 16 to be purified, after exiting the plasma torch 100 a via the discharge tube 12 a , immediately enters the plasma torch 100 b via the quartz holder 40 b , after exiting the plasma torch 100 b via the discharge tube 12 b , immediately enters the plasma torch 100 c via the quartz holder 40 c . Each swirl gas, not shown in FIG. 2, is injected through metal pipeline, entering the discharge tubes 12 a , 12 b and 12 c sideways, creating vortices inside the discharge tubes 12 a , 12 b and 12 c , stabilizing the torch flames 60 a , 60 b and 60 c . The microwave radiation intensity can be maximized at the discharge tubes 12 a , 12 b and 12 c by adjusting the depth of the stubs in the three-stub tuning devices 20 a , 20 b and 20 c . A cylindrical metal tube 42 b is set up on the waveguide 180 c to shield any leakage of microwaves and to protect the discharge tube 12 c from any mechanical impact outside. For simplicity, only three microwave plasma torches are shown in FIG. 2. However, the device 100 can be modified for efficient decontamination of large volume of air by connecting more than 3 or less than 3 microwave plasma torches in series. The number of plasma torches connected in series is determined by elimination efficiency of the each chemical and biological warfare agents. This number can be determined in terms of the warfare agent species, of the each microwave torch power, and of the flow rate of contaminated air. The 3 plasma torches in FIG. 2 are determined for the toluene gas eliminations where 1000 liters per minute of contaminated air is purified by 1 kW microwave torches. Therefore, this number must be modified for each experimental situation.
[0020] Experimental results are presented in FIG. 3, which shows the gas chromatography intensity of transmittance of toluene gas. Shown in FIG. 3 is the transmittance intensity of the toluene gas measured by a gas chromatography (GC) system for 3 microwave plasma torches connected in series, as shown in FIG. 2. The GC and the capillary column used in the experiment have the model numbers of HP 5890 and HP-PLOT Q, respectively, which are manufactured by Hewlet Pakerd (HP) Corporation in U.S.A. The capillary column has 30 m long and 0.53 mm in outer diameter. The retention time of about 7.5 minute in the horizontal line in FIG. 3 represents signature of the toluene concentration. 850 liters per minute (Ipm) of air mixed with toluene gas is used as the input gas 16 . 70 lpm of compressed air in the plasma torch 100 a , and each 40 lpm of compressed air in the plasma torches 100 b and 100 c are injected as the swirl gas in this test. Therefore, total flow rate of 1000 lpm enters the apparatus 100 presented in FIG. 2 of 3 plasma torches connected in series. Length of the connecting tube 54 a and 54 b is optimized to be 7 cm for the experimental data in FIG. 3. The toluene concentration was 150 particulates per million (ppm). One hundred percent of the toluene contaminants are transmitted through the discharge tubes without electrical discharges, as presented by the closed square dots in FIG. 3. 64.6% of the toluene contaminants are eliminated by three-microwave plasma torches connected in series when the plasma torches are on, as represented by the closed diamond dots in FIG. 3. The most dominant byproducts after elimination of toluene gas by the microwave plasma torches are observed to be water (H 2 O) and carbon dioxide (CO 2 ). The experiment was carried out five times. Thus, each data point in FIG. 3 represents an average value of five data. The input microwave power for each plasma torch is about 1 kW.
[0021] A simple first order decay model for treating target chemicals is expressed as
X X 0 = exp ( - E β ) ,
[0022] where X is the concentration of the target chemical agent after the microwave discharge, X 0 is the initial concentration of the target chemical agent and E is the energy density (joule per liter) of three microwave plasma torches connected in series. The factor β represents the energy density required for bringing down the concentration to 1/e of its initial concentration; i.e. the energy density needed for 63% decomposition. Value of the energy density β for the experimental data presented in FIG. 3 is 173 joules per liter. This value is much less than β=393 joules per liter of the pulsed corona discharge. It is also emphasized that a large volume of air can be treated by a compact apparatus in this invention. However, it is pointed out that 1000 lpm of air passes through the plasma flame of 3 kW for the experimental data in FIG. 3. Therefore, relatively hot air exits from the microwave torch. In fact, the air temperature at 50 cm downstream from the third torch in the experiment of FIG. 3 is about 80 degree Celsius for the 25 degree room temperature. In this context, the air in an isolated room may heat up like a 3 kW electric heater in the room, thereby needing a cooling system in summer.
[0023] It was observed in the repeated experiments that a synergic effect of the plasma torches connected in series is a main reason why this apparatus works effectively. Experimental data obtained from experiments, where 350 lpm air contaminated with 150 ppm toluene gas was treated by a 1-kW microwave torch, indicated only 35% decomposition of toluene molecules, which is far less than 64.6% decomposition as shown in FIG. 3. Value of the energy density β is calculated to be 396 joules per liter for one plasma torch, which is much larger than β=173 joules per liter in FIG. 3 for 3 torch system. Obviously, the synergic effect of multiple plasma torches connected in series plays a pivotal role in efficient elimination of the chemical and biological warfare agents contaminated in air. The number of torches connected in series and the length of the connecting tube 54 a and 54 b are determined by minimum value of the energy density β. The experimental data indicates the minimum value of β=173 joules per liter in FIG. 3 for 3 torch system with the connecting tube length of 7 cm in eliminating toluene gas by 1 kW microwave torches.
[0024] A thermo-coupler located about 8 cm away from the bottom of the plasma flame generated by 1 kW microwave power is about 1800 degree Celsius. The temperature increases drastically to 5500 degree Celsius measured by a spectroscopy, as the observation point approaches the bottom center of the flame. Most of the microwave power is used for ohmic heating of the flame center at a very high temperature. But, this plasma flame element drifts away from the center due to air blow, cooling its temperature as the fluid element of air moves away from the center. Temperature of any physical object like microbes moving with the plasma flame element is therefore very high due to the radiation emitted from the flame center and due to the gas temperature of the flame. The airborne biological warfare agents mixed in air can be eliminated by the high temperature of the plasma torch flames. The biological warfare agents are finely aerosolized to be airborne. For example, anthrax spores are attached on fine organic or inorganic particles with submicron size, floating freely in air.
[0025] In order to simulate killing of the biological warfare agents, vitrification experiments of sewage sludge powders are carried out. Sewage sludge powders used in the experiment were pulverized in the diameter of about 50˜500 micrometer and dried up to the moisture concentration of 10%. This experiment was done using only one microwave plasma torch of 1 kW power. The powders were injected through the discharge tube with air as a carrier gas. The powder before vitrification is very fine as prepared. The microscopic picture of 50 magnifications of the leftover ashes after vitrification experiment shows glassified grains, which are significantly larger than the initial size of the powder. Obviously, the powders were vitrified by hot local temperature of the microwave plasma torch. Volume of the sludge powers reduces considerably after passing through the microwave plasma torch, indicating that most of the hydrocarbons in the sludge were burnt out. The vitrification experiment of the sludge powers clearly indicates that the airborne biological warfare agents like microbes or bacteria attached on organic or inorganic aerosols may burn and die, as they pass through a microwave plasma torch, vitrifying the leftover ashes from burnout. Efficiency of the aerosol elimination was measured by making use of airborne soot emitted from a diesel engine. Remember that biological warfare agents are attached on the aerosol particles. Thus, elimination of aerosol in air is an effective means of killing of biological warfare agents. An intentionally-spoiled diesel engine produces a fair amount of soot, which are fine particulates made of carbon molecules. The soot elimination is measured by a collection of the soot on a white filter. The experimental data indicate that significantly more than 90% of the soot emitted from a 2000 cc diesel engine, operating with 2000 rpm, is eliminated by 3 plasma torches connected in series for the physical parameters identical to the experiment for FIG. 3. Flow rate of the discharge gas from the diesel engine used in this experiment is 4000 lpm, although the gas temperature is high. This experiment indicates that the aerosols in a large flow rate may effectively eliminated by the present invention. This experiment also clearly demonstrated that soot from the diesel engines in buses, trucks and ships can be eliminated by the apparatus of the present invention. For optimum result, the discharge gas can be recycled through the system. If there are any harmful residues, ashes, byproducts are still remain in the discharge gas, the conventional system such as scrubbers, absorbers, etc, can be attached to the present invention for elimination of these leftovers.
[0026] Although this embodiment is the apparatus for elimination of airborne toluene gas and airborne sludge powders, the invention is not limited to the use of the elimination of toluene gas and sludge powders. Without departing from the spirit of the invention, numerous other rearrangements, modifications and variations of the present invention are possible in light of the foregoing teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | The invention is directed to an apparatus made of atmospheric-pressure microwave plasma torches for elimination of toxic airborne chemical and biological warfare agents. The apparatus can purify the interior air of large volume in an isolated space such as buildings, public transportation systems, and military vehicles contaminated with chemical and biological warfare agents. The apparatus consists of several microwave plasma torches connected in series for elimination and burnout of toxic airborne warfare agents. Microwave radiation generates an atmospheric plasma torch in certain conditions. Oxidation mechanism in the torch flames eliminates the chemical and biological warfare agents. | 7 |
RELATED CASES
[0001] Priority for this application is hereby claimed under 35 U.S.C. §119(e) to commonly owned and co-pending U.S. Provisional Patent Application No. 60/781,851 which was filed on Mar. 13, 2006 and which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates in general to an improved webbing material, particularly one that can be molded or formed into a predetermined shape and has a characteristic of being retained in that shape. The present invention also pertains to a method of forming a woven fabric so that it can be molded into a permanent predetermined form or shape. The present invention is considered as having a multitude of possible applications, such as in the fall protection industry, for recreational products, in the medical field, the apparel industry, for the military and possibly for home land security applications.
BACKGROUND OF THE INVENTION
[0003] Narrow fabric webbing may be defined as any woven, braided or knitted textile product that, in general, is less than 12 inches in width, but may also be wider such as 18 inches in width. These narrow fabric structures can be fabricated using spun textile yarns made from natural fibers and or synthetically manufactured fibers in continuous filament form.
[0004] Traditionally the majority of woven narrow fabric products are comprised of the same class of fiber such as a 100% cotton structure as used in the manufacture of belts for apparel or 100% continuous filament polyester such as is used in automobile seat belt applications. The selection of materials is based on the particular requirements and end use of the finished product. Generally, if a soft flexible finished narrow fabric product is desired, spun or textured yarns are selected as the primary substrate. Similarly, in a seat belt application low elongation, high strength and a light weight fabric are desirable physical properties, thus continuous filament polyester is a desirable substrate. If thermal properties are desired the fiber choice may be selected from the “aramid” class of synthetic fibers.
[0005] To further enhance the desired physical properties or hand characteristics of a woven narrow fabric one must give equal consideration to the type of weave and density of the fabric. Typically woven narrow fabric weaves are selected but not limited to the traditional class of weaves such a plain weave, twill weave, satin weave, double plain weave, stuffer weaves, etc. Denser weave constructions may be used to increase the breaking strength of a woven narrow fabric.
[0006] Currently there are no narrow fabrics that are available on the market using any of the above mentioned constructions, densities or combination of yarns that allow woven narrow fabric webbing to be formed so as to retain a selected shape. As a matter of fact there is also no such fabric available whether for narrow fabric applications or for wider fabric applications.
[0007] It is, therefore, very desirable and would have commercial value to develop a narrow fabric webbing that is able to retain it shape when formed. The present invention addresses this matter.
SUMMARY OF THE INVENTION
[0008] To accomplish the foregoing and other advantages the present invention is embodied in a woven fabric that is characterized by retaining its shape once formed. The woven fabric comprises mono-filament filling yarns that are disposed in at least two separate plies; ground yarns that weave alternatively over and under respective mono-filament filling yarns; stuffer yarns that extend in a direction between mono-filament filling yarns of respective plies and binder yarns that extend between mono-filament filling yarns of respective plies.
[0009] Other aspects of the present invention include the mono-filament filling yarns may comprise a continuous single spun mono-filament; mono-filament filling yarns are selected from the group that includes nylon, polyester and polypropylene; the mono-filament filling yarn may have a yarn size in a range between 14 and 10,000 denier; the density of the mono-filament filling yarn may be in a range of 5-100 yarns per inch or more preferably 10-20 yarns per inch; the stuffer yarns are also mono-filament yarns so as to enable shape retention in both warp and weft directions; the mono-filament filling yarns may have a diameter of at least 0.002 inch; and ground and binder yarns may be a 20/2 spun polyester.
[0010] In accordance with another feature of the present invention there is provided a method of forming a woven fabric into a predetermined shape, comprising the steps of: providing a woven fabric that includes a mono-filament filling yarn that is disposed in separate plies; weaving a ground yarn alternatively over and under respective mono-filament filling yarns; forming the fabric into the predetermined shape; and applying heat to the thus formed fabric at a temperature of at least 150° F. for at least 5 minutes, but depending on the particular type of monofilament yarn that is used.
[0011] In accordance with further aspects of the present invention the monofilament yarns may be from a class of manmade synthetic yarns; the warp yarns may have a minimum yarn size of 50,000 yards per pound; the binder yarns may have a minimum yarn size of 50,000 yards per pound; the picks across the width may have a range of 5 per linear inch to 100 per linear inch; the minimum density of the monofilament filling yarn may be between 5 picks per linear inch using a monofilament yarn having a yarn size of 14 denier up to 100 picks per inch using a monofilament yarn having a yarn size of 10,000 denier; and the warp yarns may have a minimum density of 144 ends per inch having a minimum yarn size of 50,000 yards per inch.
DESCRIPTION OF THE DRAWINGS
[0012] Numerous other features and advantages of the present invention are realized upon a reading of the detailed description that follows when taken in conjunction with the accompanying drawings, in which:
[0013] FIGS. 1A-1G illustrate the ground weaves, stuffer yarns and binder yarns as related to the mono-filament filling yarns used in fabricating a fabric in accordance with the present invention;
[0014] FIG. 2 is a perspective view that illustrates the relationship between the various yarns for a double plain weave with 1 up 1 down binder and stuffers: and
[0015] FIG. 3 shows the same perspective view as in FIG. 2 but illustrating the manner in which the ground yarns are able to slide over the mono-filament yarns to retain fabric shape.
DETAILED DESCRIPTION
[0016] The fabric of the present invention is capable of retaining its shape when it is molded into virtually any shape or configuration. The fabric may be formed around an object or series of objects in order to define a particular shape. For example, the fabric may be pre-formed by hand into an “S” or “L” configuration for such applications where multiple shapes are desired. A heat cycle may be used to maintain the molded fabric into a more or less permanent form.
[0017] Narrow and other fabrics are manufactured using various weave configurations. Weave configurations used in the fabric industry are comprised of, but not limited to the following types of weaves.
[0000] Plain weave
3 up 1 down twill
3 up 1 down 1 up 3 down twill
Plain tubular weave
2 up 2 down tubular weave
3 up 1 down tubular weave
5 up 1 down 1 up 5 down with or without binder yarns
7 up 1 down 1 up 7 down with or without binder yarns
Double plain weave with 1 up 1 down binder sequence
Double plain weave with 2 up 2 down binder sequence
Double plain weave with 1 up 1 down binder and stuffers
Double plain weave with 2 up 2 down binder and stuffers
Self-interlocking 12 pick repeat
Self-interlocking 14 pick repeat
Three ply—face middle back with 3 up 3 down binders
Three ply—face middle back with 2 up 2 down binders
Double wall tubular with connected edges
Slotted weave
2 up 1 down 1 up 2 down twill with binders and stuffers
4 ply plain weave
4 ply self-interlocking
[0018] The above weave configurations may consist of yarns of various sizes and types. There are yarns that weave in the length wise direction, parallel to the edges and a yarn or yarns which weave across the width of the webbing from edge to edge. The yarns that weave in the length wise direction are usually referred to as warp or ground yarns and the yarns which weave across the width of the webbing are referred to as filling yarns, weft yarn or picks.
[0019] The present invention is based, in one embodiment thereof, on the webbing being able to be folded in the filling direction, such as that illustrated in FIG. 3 herein. The density of a narrow fabric is determined by the number and size of warp and filling ends per given length of webbing. Denser webbing has been found to have better ability to retain its shape when folded than webbing that is less dense. However, to provide shape retention it has been found in accordance with the present invention that a mono-filament fiber is to be used for the filling yarns. Alternatively, if the bending is desired in the orthogonal direction then the ground or stuffer yarns are mono-filament.
[0020] Thus, in a preferred embodiment the present invention is directed to a webbing that uses a mono-filament yarn in the filling direction. The mono-filament yarn is a single filament of a manufactured fiber, usually of a denier of at least 14. Instead of a group of filaments being extruded through a spinneret to form a yarn, mono-filaments are generally extruded individually. The mono-filament yarn may come from the class of manufactured fibers of nylon, polyester, polypropylene or any such fiber than exhibits the characteristics to allow the webbing to be molded.
[0021] The principles behind a narrow fabric being able to be molded are basically two fold. The first being the use of a mono-filament filling yarn and the second is the density of the fabric itself, particularly the density of the pick count. The preferred weave design for this invention is a double plain weave with 1 up 1 down binder and stuffers. However, any one of the previously listed weaves or other weaves may be used in practicing the principles of the present invention. A mono-filament yarn has greater stiffness than a multifilament yarn of equal size. In this preferred weave design the filling yarn (weaves from edge to edge) is inserted by either a weft needle as in a needle loom or by a shuttle as would be used in a shuttle type loom. The loom is programmed so as to insert the first filling yarn (pick) 10 on the bottom ply of the 2 ply weave. The next filling yarn 10 is inserted on the top ply of the 2 ply weave. The filling yarn alternates from bottom to top for each pick. Numbering the sequence of picks, as illustrated in FIGS. 1A-1G , shows all the odd numbered picks lie on the back of the webbing and all the even numbered picks lie on the face of the webbing, or visa versa if the first filling yarn is inserted on the face of the webbing. See FIG. 1A to 1D and the numbered picks 1-24.
[0022] One half of the ground ends 12 weave on the top ply of the webbing and the other half weave on the bottom ply of the webbing. The stuffer yarns 14 weave under the filling yarns 10 that weave on the top ply and over the filling yarns that weave on the bottom ply. Lastly, the binder yarns 16 have a 1 up 1 down weave configuration as shown in FIG. 1E . These binder yarns 16 lock the double plain 2 ply construction together and contribute to the retention feature of the present invention. This weaving sequence includes first weaving under filling yarn number “1” and over filling yarn number “2”, under “3”, over “4” and so on. This binds all the components together. Refer to FIG. 1 .
[0023] The preferred embodiment for the ground and binder yarns is a 20/2 spun polyester. Since the stuffer yarns 14 do not actually weave, they just lie between the top and bottom ply, the preferred embodiment for the yarns 14 can be either spun polyester or continuous filament yarns. Lastly, the mono-filament filling yarn 10 preferred embodiment has a yarn size between 14 denier and 10,000 denier.
[0024] It is theorized that the reason this invention has moldable properties is because of the propensity of the ground yarns to be able to slide over the mono-filament filling yarns. This occurs when the fabric is bent in the filling direction, such a shown in FIG. 3 at 20 . Although the ground ends slide over the filling yarns when bent in the filling direction, there is not enough recovery forces in the filling yarns to allow the ground ends to slip back into their original position, thus the webbing keeps its shape. By making the construction denser, particularly the density of the filling yarns, the moldability is increased. The fabric retains its shape until a force that exceeds the bending force of the filling yarn is applied to the fabric. When a force that exceeds the bending force of the mono-filament filling yarn is applied to the fabric, the ground yarns return to their original position and the fabric returns to its original shape. The mono-filament filling yarn 10 because of its high stiffness properties lies flat and straight across the width of the fabric allowing for slippage of the ground ends 12 . The filling yarn does not weave around the ground ends in the weaving operation, the ground ends weave around the filling yarns. See FIGS. 2 and 3 .
[0025] It is also possible to use the same theory to mold the webbing in the opposite direction. The principal is that the non-mono-filament yarns be able to slide over the mono-filament yarns. To have moldable properties in the warp direction one would change the stuffer yarn type from spun or continuous filament to the stiffer mono-filament yarns. Density would again play an important role. A denser mono-filament construction for the stuffer weave, the stiffer and more moldable the fabric is in the warp direction. Combinations of densities in both stuffer and filling directions allows a fabric to be built that possesses more moldable characteristics in the filling and less in the warp direction or better moldable properties in the warp direction and less in the filling direction. The possibilities are limitless depending on the end item use.
[0026] Trials have been performed on a Murdock Webbing Part Number 1198, 5-1/2″ webbing varying the ambient temperatures to see how and what physical properties might be influenced. The first trial was to subject the webbing to 150° F. temperatures for a couple of hours. The webbing with polyester monofilament filling did not loose its moldable properties while at 150° F. When brought back to room temperature the product retained all of its original physical and moldable properties.
[0027] Heat on the other hand has quite a different effect on the product. A great deal of textile products are woven with natural yarns and then exposed to a secondary process to affix the color. These processes normally expose the webbing to some type of dyestuff in an aqueous solution, then dried at elevated temperatures between 200-325° F. for varying amounts of time.
[0028] The trials that were conducted showed that all moldable properties were lost when the webbing was exposed to temperatures in the 225° F. range or higher. Thus, if color is to be added to this moldable webbing during the fabrication process, one has to use pre-dyed yarns or air dry the product at ambient temperature.
[0029] Additional trials were run to find out at what point on the temperature line did the webbing began to loose its moldable properties. The first trial was to expose the product to temperatures of 150 to 200° F. at 10 degree increments for one hour. Under these conditions the webbing did not loose moldability. However at 200° F. for 8 hours the webbing did loose substantially all of its moldability.
[0030] Another trial was run to see if heat could be used to permanently mold the fabric product. In one test using nylon or polyester filler yarns the moldable webbing was wrapped around an object, tied in place and the core and webbing was exposed to 250° F. for at least 5 minutes. When the core was removed the webbing retained the shape of the core and could not be brought back to its original flat shape. In another example, using polypropylene for the filler yarns it was found that the product could be permanently molded by the application of a temperature of at least a 150° F. for at least 5 minutes. In either of the above examples, it is preferred that the subjected temperatures be exposed for greater than 5 minutes, perhaps as long as 4-8 hours.
[0000] Samples of a 2 inch wide narrow fabric were made using the following construction:
Weave: Double Plain with 1 up and 1 down binder sequence
Ground ends: 288 ends 20/2 spun polyester
Binder ends 35 ends 20/2 spun polyester
Stuffer ends 170 ends 1000/2 continuous filament polyester
Stuffer ends 72 ends 2150 denier mono-filament polyester
Filling Yarn 17.5 picks of 2150 denier monofilament polyester filling (2 picks per shed).
[0031] The density of the filling yarn was calculated. The formula used was the total picks per inch times the denier of the filling yarn is:
[0000] 17.5 picks per inch×2 picks per shed×2150 denier=75,250 total denier.
[0032] A method was developed to determine the force required to bend this webbing in the filling direction. The test involved taking the 2″ wide sample, placing it in a set of 3″ wide flat faced clamps in a vertical position and clamping it in position with 1½″ exposed over the top of the clamp. Next the 3″ of webbing was bent in the filling direction at a 15 degree angle from vertical. The load was applied from the top clamp compressing the webbing in the bottom clamp with a speed of 1 inch per minute. The load was recorded when the top clamp compressed the webbing in the bottom clamp by 1 inch.
[0033] Additional samples were made reducing the pick count (density) of the filling yarn and the same test method applied to the less dense webbing to show the effect of density on the force required to bend or mold the webbing in the filling direction. The table below illustrated the relationship between filling density and bending force.
Trial #1 17.5 picks per inch 2150 filling=75,250 total denier=9.86 pounds force at a 1″ deflection. Trial #2 16.0 picks per inch 2150 filling=68,800 total denier=7.50 pounds force at a 1″ deflection. Trial #3 14.0 picks per inch 2150 filling=60,200 total denier=5.69 pounds force at a 1″ deflection. Trial #4 12.0 picks per inch 2150 filling=51,600 total denier=3.67 pounds force at a 1″ deflection. Trial #5 10.0 picks per inch 2150 filling=43,000 total denier=1.54 pounds force at a 1″ deflection.
[0039] The same type testing was done on the above sample but in the warp direction. The construction of the webbing is the same as in trial #5 with the exception of the addition of the mono-filament stuffer ends. The first sample used 72 ends of 2150 denier and the second sample used 36 ends of 2150 denier. The test was done the same way with the warp yarn in the vertical direction at a 15 degree angle. The bending force in the warp direction is listed below:
Sample #1 72 ends per inch 2150 stuffer=154,800 total denier=2.82 pounds force at a 1″ deflection. Sample #2 36 ends per inch 2150 stuffer=77,400 total denier=1.42 pounds force at a 1″ deflection.
[0042] The woven fabric of the present invention is thus characterized by a number of factors that enable this moldability. First is the use of a mono-filament yarn in the filling direction. If moldability is desired in the warp direction there are to be mono-filament yarns in the stuffer weave. Second is the density of the fabric, particularly in the filling direction. This preferably is at least 14 denier and is preferably in a range of 14-10,000 denier. It is also preferred that the fabric be constructed in a dual ply arrangement. For the product to permanently keep its shape, when using nylon or polyester, it is to be exposed to a minimum temperature of 250° F. for at least 5 minutes and preferably more than that even up to 8 hours when using a 2150 polyester monofilament yarn for filling.
[0043] Having now described a limited number of embodiment of the present invention, it should now be apparent to those skilled in the art that numerous other embodiments and modifications thereof are contemplated as falling within the scope of the present invention as represented by the appended claims. | A woven fabric that is characterized by retaining its shape once formed and that includes monofilament filling yarns that are disposed in at least two separate plies, ground yarns that weave alternatively over and under respective monofilament yarns, stuffer yarns that extend in the direction between monofilament filling yarns of respective plies and binder yarns that extend between monofilament filling yarns of respective plies. Also disclosed is a method of forming a woven fabric into a permanent shape. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Application Ser. No. 60/753,630 filed Dec. 23, 2005; the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates to security devices, systems and methods for protection of merchandise, and in particular, a programmable smart key for use in a security system wherein the key is programmed with a security disarm code (SDC) at a programming station and is used to program the SDC code into various alarm modules adapted to be attached to items of merchandise by wireless communication.
2. Background Information
Various retail establishments use numerous types of theft deterrent devices and systems to discourage shoplifters. Many of these systems use various types of alarm modules or other security devices which are attached to the article to be protected in one manner or another. When the integrity of the module or the item of merchandise protected thereby is compromised in any manner, such as cutting the attachment cables which attach the alarm module to the item of merchandise, removing the merchandise from the alarm module or disturbing the alarm module, will cause an audible alarm to be sounded in the module to alert store personnel that the item of merchandise or security device is being tampered with illegally. These alarm modules, as well as the items of merchandise protected thereby, also may contain various electronic article surveillance tags (EAS) which will sound an alarm at a security gate upon passing through the gate in an unauthorized manner.
These alarm modules or security devices which are attached to the items of merchandise usually have some type of key, either mechanical or magnetic, which is used to unlock the device from the protected item of merchandise to enable the merchandise to be taken to a checkout counter, as well as to disarm an alarm contained in the alarm module. One problem with such security systems is that these keys will be stolen from the retail establishment and used at the same establishment or at another store using the same type of alarm module or security device, to enable a thief to disarm the alarm module as well as unlock it from the protected merchandise. These keys also are stolen by dishonest employees for subsequent unauthorized use by the employee or sale to a thief for use at the same store or at other stores which use the same alarm modules controlled by the key.
It is extremely difficult to prevent the theft of these keys by dishonest employees or even by a thief within the retail establishment due to the number of keys that must be available and used by the various clerks in the various departments of the store to facilitate the use of the numerous alarm modules and security devices that are needed to protect the numerous items of merchandise.
Thus, the need exists for a security system and in particular a disarming key used thereon, which system uses various types of alarm modules and security devices which are attached to various items of merchandise, which will prevent a thief or dishonest employee from using the key that is used to disarm and unlock the security device in an unauthorized manner on similar types of alarm modules and security devices at various retail establishments including the store from which the key was stolen.
BRIEF SUMMARY OF THE INVENTION
One aspect of the present invention is to provide a security system for protecting items of merchandise, and in particular a key used therein for disarming and unlocking the security device from the merchandise, which key is programmable with a unique security disarm code (SDC), which code is provided to the key by a programming station, wherein the SDC is unique to a particular retail establishment thereby preventing the key to be used at a different store than that from which the key is stolen.
A further aspect of the present invention is to use the key in which the SDC is programmed to program each of the individual alarm modules or security devices with the same SDC when the alarm modules and devices are first activated, which enables the SDC to remain with the security device throughout its use in the particular retail establishment for subsequent matching with the SDC stored in the key.
Another aspect of the present invention is to provide the smart key with an internal timer which after a preset period of time, for example 96 hours, will automatically invalidate the SDC in the key thereby preventing its unauthorized use even in the particular retail establishment in which the programming station is located and SDC protected security devices are used, after the preset time period.
A further feature of the present invention is that the smart key must be reprogrammed with the SDC after a preset time period, which can be performed by authorized personnel, insuring that the key can only be used by authorized clerks, and only in the store having a programming station and a single SDC for all of the security devices in the store.
Still another aspect of the present invention is to provide the key with a wireless communication circuit for receiving the SDC from a programming station and subsequently transferring the SDC into the security device.
Another feature of the present invention is to provide the smart key with an internal counter which counts the number of activations performed by the key, that is, the initial activation of every security device in the store as well as each time the key is used to disarm one or more of the security devices, and upon a predetermined number of activations occurring will permanently inactivate the key thereby ensuring that an active key always has sufficient internal power to receive the SDC and subsequently communicate with the individual security devices for disarming the devices when required.
A further feature of the present invention is to enable the internal counter to actuate an indicating signal a predetermined time period before permanently deactivating the control circuit after the maximum number of activations have been provided by the key.
A still further aspect of invention is to enable the security device to actuate an alarm if the key is attempted to be used to disarm the security device containing a wrong SDC.
Still another aspect of the invention is to provide the key with a visual indicator which is operatively connected to an internal logic control circuit and is pulsed to indicate the state of the SDC stored therein.
A further feature is to provide the key with a wireless communication circuit, such as infrared (IR) or radio frequency (RF), for programming the SDC into a security device; and in which the key is provided with a visible light filter to enhance the transmission and reception of IR waves when the wireless communication is an IR circuit.
Another feature of the invention is that should a key programmed with an SDC from one store be used in a programming station of another store, the time-out feature will immediately be activated removing the SDC from the key rendering it inactive from further use.
These features are obtained by the programmable key of the present invention which is intended for use in a security system for protecting items of merchandise, the key comprising a housing; a power supply mounted in the housing; a logic control circuit including a controller, a wireless communication circuit and a security disarm code (SDC) memory mounted in the housing and connected to the power supply by a control switch, wherein the controller initially receives an SDC from a remote source through the wireless communication circuit for storage in the SDC memory and for subsequent transmission of the SDC code by the wireless communication circuit to a security device adapted to be attached to an item of merchandise upon actuation of the control switch.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
A preferred embodiment of the invention, illustrated of the best mode in which Applicant contemplates applying the principles, is set forth in the following description and is shown in the drawings and is particularly and distinctly pointed out and set forth in the appended claims.
FIG. 1 is a top plan view of the key of the present invention.
FIG. 2 is a sectional view taken along line 2 - 2 , FIG. 1 .
FIG. 3 is the electrical circuit schematic of the logic control circuit of the programmable key of the present invention.
FIG. 4 is a top plan view of the circuit board of the programmable key.
FIG. 5 is a block diagram of the programmable key.
FIGS. 6 , 6 A and 6 B are flow charts showing the manner of operation of the programmable key.
FIG. 6C is a list of the abbreviations used in the flow charts of FIGS. 6 , 6 A and 6 B.
FIG. 7 is a diagrammatic representation of one type of security system in which the key of the present invention can be used.
Similar numbers refer to similar parts throughout the drawings.
DETAILED DESCRIPTION OF THE INVENTION
The programmable key of the present invention is indicated generally at 1 , and is shown particularly in FIGS. 1 and 2 . Key 1 preferably includes a housing indicated generally at 3 , formed by an upper housing member 5 and a lower housing member 7 which can be joined together by an adhesive, ultrasonic weld or other type of connection, and which form an internal chamber 9 therein. Housing members 5 and 7 preferably are formed of a rigid plastic and may have a generally oval-like configuration as shown in FIG. 1 , and form an opening 11 at one end thereof to provide a convenient location for attaching a chain, lanyard or the like to assist in maintaining control of the key while in use or in storage by a clerk or store manager.
In accordance with one of the main features of the invention, a logic control circuit is formed on a printed circuit board 13 and is located within housing chamber 9 . The logic control circuit includes a main controller, which preferably is a microprocessor 15 , a security disarm code (SDC) memory 17 , a wireless communication circuit 19 and an activation switch 21 . The details of the various circuitry is shown in FIG. 3 . The logic control circuit is powered by an internal battery 23 which is located beneath circuit board 13 within housing 3 , and is in electrical contact therewith by terminals 25 and 27 . The opposite end 28 of housing 3 is formed with an opening 29 in which is mounted a lens 31 , which preferably will be a visible light filter to enhance the transmission and reception of infrared (IR) waves when the wireless communication circuit 19 is an IR circuit operating on IR wavelengths. The use of infrared as the communication media is preferred, although radio frequency wave communications and other types of wireless communication can be used to achieve the same effect. Switch 21 is covered by a flexible member 33 , which when pressed downwardly as shown by Arrow A, FIG. 2 , will compress sufficiently to actuate internal switch 21 .
An LED 35 is mounted on printed circuit board 13 and is located adjacent a light pipe 37 mounted in upper housing 5 , to enhance the visual effect of LED 35 when actuated. A foam pad 38 preferably is located between battery 23 and printed circuit board 13 and secures battery 23 in position, as well as providing cushioning for the circuit board and maintains its spacing and location within housing chamber 9 .
Controller 15 includes as a feature thereof a timer shown diagrammatically for illustrative purposes as block 39 in FIG. 5 , and a lifetime counter shown diagrammatically in FIG. 5 and indicated at 41 , the functions of which are discussed below. FIG. 4 shows an example of printed circuit board 13 which will contain controller 15 , switch 21 , and various resistors R and capacitors C which are shown in further detail in FIG. 3 .
It is readily understood that the particular circuitry shown in FIG. 3 and the values of the various resistors, capacitors, diodes, etc. are easily determined by one skilled in the art and can vary while providing the main principles and features of the invention.
Key 1 is intended to be used primarily in a security system for protecting items of merchandise such as shown and described in a copending patent application entitled, Security System And Method For Protecting Merchandise, filed concurrently herewith, and shown diagrammatically in FIG. 7 . This security system includes a programming station 43 such as shown and described in copending patent application entitled, Programming Station For A Security System For Protecting Merchandise, and numerous security devices 45 which are connected to items of merchandise 47 by an alarm cable 51 or other attachment device to prevent the theft thereof. Examples of such security devices are shown and described in a copending patent application concurrently filed herewith entitled, Programmable Alarm Module And System For Protecting Merchandise. The particular details, construction and manner of operation of the security system, programming station 43 and security device 45 are shown and described in the said pending applications, the contents of which are incorporated herein by reference.
Key 1 , when supplied to a retail establishment, preferably will not contain any coded information and will obtain the same by communicating with the circuitry of programming station 43 via wireless communication circuit 19 . This is accomplished by placing housing end 28 , and particularly lens 31 , adjacent a wireless communication port 49 in programming station 43 , and upon actuation by depressing button 21 , will receive a randomly generated security disarm code (SDC) from programming station 43 . Once generated by programming station 43 , this SDC preferably will always remain the same throughout the useful life of key 1 . This SDC is received and stored in SDC memory 17 of the control logic circuit of key 1 . Key 1 is then taken by a clerk to a security device 45 , which could be an alarming module or other type of device, which is connected to merchandise 47 by a cable 51 , flexible conductor or other type of lanyard which preferably includes a sensing loop which will prevent the removal of merchandise 47 therefrom and/or will cause an alarm to be sounded in security device 45 if the integrity thereof is compromised. The particular form and type of security device 45 can vary considerably from that shown in the above referenced pending patent application without affecting the concept of the invention. Key 1 is then placed in a wireless communication port 53 formed in security device 45 . Switch 21 is again activated, and communication circuit 19 will transmit the previously stored SDC from key 1 into an SDC memory contained in a logic circuit of security device 45 .
Upon key 1 acquiring the SDC from programming station 43 , it will start internal timer 39 which has been preset at the factory, for example 96 hours, which through the control logic circuit will automatically invalidate the SDC contained therein, unless refreshed within the preset time period, thereby making the key inoperative for further use even by authorized personnel. This prevents the key from being stolen and then subsequently reused in the same store after this preset time period, and even more importantly, since the SDC is unique only to that store, the key cannot be taken to another store even using the same type of security system and security devices, and be used in an unauthorized manner since the SDC contained therein will not match the SDC previously stored in the security devices of a different store. Thus, a store clerk after the key has been programmed with the SDC initially or revitalized within the time period by placing it in wireless communication with programming station 43 , can use it with the security devices 45 to either disarm an alarm contained in the security device and/or activate a lock mechanism etc. to enable the security device to be disarmed or unlocked or removed from a protected item of merchandise for completing a lawful sales transaction.
Each time button 21 is activated, counter 41 will record the actuation. The logic circuit has been preset at the factory in combination with counter 41 , that after a certain number of activations, for example 55,000, the logic circuit will completely shut down and forever be inoperative. This is referred to as an “end-of-life” counter and it begins counting on the first receipt of the actuation of switch 21 and all subsequent activations thereof. This end-of-life counter ensures that battery 23 always has sufficient power for operating the SDC memory and wireless communication circuitry of key 1 before losing its charge to be ineffective. This prevents using key 1 beyond its useful life. However timer 39 will be automatically reset each time key 1 is brought into communication with the SDC programmer of station programmer 43 .
FIG. 6A and FIG. 6B are the flow charts describing the sequence of operation that the control logic circuit follows when switch 21 is actuated and the key is located adjacent to the wireless communication port 49 of programming station 43 and near communication port 53 of security device 45 . The flow charts show the effect that occurs if timer 39 has exceeded its time limit and deletes the SDC from a key and what could occur if end-of-life counter 41 has reached the preset number of activations. The flow charts also show that LED 35 will flash at various times to provide various signals, such as when the button is initially pressed to reset the SDC after it is timed out, as well as when it confirms the match with the SDC stored in the security device. For example, LED 35 will flash one time when switch 21 is depressed indicating that the key is operational, but that it has no SDC programmed therein. LED 35 will flash twice when switch 21 is depressed indicating that the key is operational and has the SDC programmed therein, and that it is ready to be used with a security device.
In summary, key 1 provides a programmable or smart key that receives a randomly generated SDC from a programming station unique to an individual retail store, and stores it in an internal memory, in combination with a timer which after a preset period of time will delete the SDC from the memory rendering the key inoperable, and which includes a wireless communication circuit preferably IR or RF, for receiving the SDC from a programming station and for supplying the SDC to a control logic circuit built into a security device. This enables the key to actuate the security device such as disarming an internal alarm, operating a locking mechanism or the like. Furthermore, the key contains an internal counter which counts the number of times the key is activated, either in conjunction with the SDC programmer or a security device, to ensure that the battery has sufficient power to properly maintain the functions of the key.
Furthermore, the logic control circuit of the programming station upon reading an SDC from a smart key different from the unique SDC stored in the program station will immediately time-out the usable time period in the key rendering it useless. This prevents a thief from using a programmed key from one store in the programming station of another store even if the key has yet to be timed out.
Although the above description refers to the security code being a disarm code, it is understood that the code can activate and control other functions and features of the security device such as unlocking the device from the product, shutting off an alarm etc. without departing from the concept of the invention. Likewise, the various components of the logic circuit and resulting flow charts can easily be modified by one skilled in the art to achieve the same results. Also, the security code can be preset in programming station at the factory or chosen by the customer, and if desired, be changed later by the customer, also without affecting the concept of the invention.
In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.
Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described. | A programmable key for use in a security system for protecting items of merchandise has a housing, a power supply mounted in the housing, a logic control circuit which includes a controller, a wireless communication circuit and a security disarm code (SDC) memory. The key has visual indicators such as an LED which is operatively connected to the logic control circuit and pulsed to indicate the state of the SDC. The control circuit includes a timer which has a preset time limit programmed therein, which invalidates the stored SDC if not refreshed by a remote programming source within a certain time period. The logic circuit further includes a counter which counts the number of activations of a control switch, and which permanently deactivates the control circuit upon reaching a certain count value to ensure that the internal battery has sufficient power to maintain the key operational. The wireless communication circuit preferably is infrared (IR) or radio frequency (RF) controlled. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
Applicant hereby claims foreign priority benefits under U.S.C. §119 from German Patent Application No. 10 2006 057 364.1 filed on Dec. 4, 2006, the contents of which are incorporated by reference herein.
FIELD OF THE INVENTION
The invention concerns a water hydraulic machine with at least one piston arranged to be movable in a cylinder, the piston being connected to a slide shoe that has a sliding surface, with which it is supported on a swashplate, a friction reducing plastic material being arranged between the sliding surface and the swashplate.
BACKGROUND OF THE INVENTION
Such a water hydraulic machine is, for example, known from DE 102 23 844 A1. Such a machine works with water as hydraulic medium. As water has no lubricating properties, a friction reducing plastic material is used to ensure that parts moving in relation to each other can slide on each other in the most low-wear manner possible.
For the purposes of the following description, the term “friction reducing” must always be understood so that the plastic material interacts with the material, on which it bears, in a friction reducing manner. If, for example, the swashplate is made of steel, the plastic material interacts with the steel in a low-friction manner.
Water hydraulic machines as offered by Danfoss A/S, Nordborg, Denmark under the name “Nessie” have proved their value in many applications. For example, such a water hydraulic machine can be used as pump in a reverse osmosis system.
If the water hydraulic machine has to be dimensioned for a high performance, it may turn out that damages occur on the friction reducing plastic material after a certain operation time.
SUMMARY OF THE INVENTION
The invention is based on the task of securing a sufficient lifetime also of high-performance water hydraulic machines.
With a water hydraulic machine as mentioned in the introduction, this task is solved in that a contact zone between the sliding surface and the plastic material is made to be radially exposed in at least one position in the circumferential direction.
With this solution it is assumed that particularly with large pumps with a delivery rate in the range of several 100 l/min and a delivery pressure of 50 bar or more damages to the plastic material on the sliding surface sometimes appear, which cause that water can penetrate to the area between the plastic material and the sliding surface, that is, into the contact zone. Now, this water can escape from the contact zone without problems, as in the radial direction the contact zone has an exposed area, which is not, as it has been the case until now, covered or closed by a further area of the plastic material. Accordingly, an excessively high pressure cannot build up between the plastic material and the sliding surface, which would eventually cause the plastic material to get detached from the sliding surface. Thus, also when the plastic material has no damages, like cracks or the like, it otherwise remains stable on the sliding surface.
Preferably, the contact zone is made to be exposed radially outwards. Here, the term “radially outwards” relates to the slide shoe, which usually has a circular sliding surface. Also when the shape of the sliding surface deviates from the circular shape, “radial” means a direction which extends from the centre of the slide shoe and outwards. At the radial outside of the slide shoe the smallest water pressure rules, so that water, which has entered between the plastic material and the sliding surface, can escape here.
Preferably, the plastic material has a circumferential projection extending in the direction of the swashplate, the projection surrounding an area, whose surface is as large as a pressure application surface of the piston in the cylinder. Thus a pressure relief can be achieved, when water gathers in the area, which is, in a manner of speaking, supporting the slide on the swashplate.
This is particularly the case, if the area is connected to a pressure chamber located in the cylinder. Then, it is easy to make sure that the same pressure as in the cylinder always rules in this area. However, this is exactly the pressure that acts upon the piston and presses the slide shoe against the swashplate via the piston. As the surfaces are equally large, a power balance occurs. In this way, the mechanical stress on the plastic material is small.
Preferably, the plastic material is connected to the slide shoe in a form-fitting manner. Firstly, this form-fitting connection must ensure that no displacements can take place between the plastic material and the sliding surface parallel to the sliding surface. A form-fitting connection can also be realised, when the contact zone between the slide shoe and the plastic material is open in the circumferential direction in one position or in some positions, so that water, which has penetrated between the sliding surface and the plastic material, can escape here.
Preferably, the sliding surface of the slide shoe has an undercut recess in the radial direction, said recess being engaged by the plastic material. This gives two effects. Firstly, the plastic material is not only fixed in a direction, which is parallel to the sliding surface of the slide shoe, but also in a direction, which is perpendicular to said surface. The plastic material engages the undercut of the recess and is thus particularly well fixed. Secondly, such an undercut causes an increased sealing length, so that the risk that water penetrates into the area of the recess between the slide shoe and the plastic material can be kept small.
Preferably, in the recess the plastic material surrounds a bore in the sliding surface, in which a working pressure in the cylinder rules. The working pressure then pushes the plastic material radially outwards and provides an improved sealing between the plastic material and the slide shoe. The working pressure can, for example, be provided in that the piston has a channel that ends in the recess.
Preferably, the circumference of the slide shoe is covered by a layer of a friction reducing synthetic material, having at several positions in the circumferential direction a connection to the plastic material. The plastic material and the synthetic material can be made in the same manner. The synthetic material ensures that the slide shoe is movable in relation to a pressure plate without causing considerable wear. This synthetic material can then at the same time be used to fix the plastic material to the sliding surface. Still, interruptions remain, in which the contact zone between the plastic material and the sliding surface is not covered, so that here entered water can escape from the contact zone.
Preferably, at least one of the connections is form-fitting with the sliding surface in the circumferential direction. This can, for example, be realised in that the connection between the synthetic material and the plastic material is located in a groove in the sliding surface, the groove extending substantially in the radial direction. This gives an even better fixing of the plastic material on the slide shoe.
An alternative embodiment may foresee that the plastic material is made as a disc, which is connected to the slide shoe by means of plug connection extending in a direction that is perpendicular to the sliding surface. With this embodiment it is considered that during operation basically only shear forces act in parallel to the sliding surface upon the connection between the slide shoe and the plastic material. Axial forces, that is, forces perpendicular to the sliding surface, have practically no damaging effect, as the piston always presses the slide shoe against the swashplate with sufficient force. When the plastic material is made as a disc, which is merely attached or pushed in, this disc can easily be replaced if required, without requiring the replacement of further elements of the machine. This simplifies the maintenance and reduces the cost of the maintenance. The lifetime of the machine can be substantially extended by replacing such a disc.
It is preferred that the side of the disc facing the sliding surface has a recess. Thus, water is permitted to penetrate into the area between the disc and the sliding surface. This water has no problems to escape at another position, so that the cohesion between the disc and the slide shoe in a direction parallel to the sliding surface is practically not impaired.
Preferably, the recess has a surface, which is smaller than the surface of the area. The pressure ruling in the area then presses the disc with a sufficient force against the sliding surface and at the same time supports the slide shoe in a hydraulic balance in relation to the swashplate.
Preferably, the slide shoe has a projection projecting from the sliding surface, the disc being attached to said projection. This is a particularly simple embodiment. The whole circumference of the disc can then be exposed, so that also the contact zone between the disc and the slide shoe is made to be exposed on the whole circumference. Water penetrating between the slide disc and the plastic material can then escape radially outwards in any position.
It is preferred that the projection is made as an extension of a plastic material element, which is located between the slide shoe and a ball fixed on the piston. The plastic material element is also made from a friction reducing plastic material and ensures that the slide shoe can swing randomly in relation to the piston in such a manner that the sliding surface always remains aligned in parallel with the swashplate. In many cases, the plastic material element will be injected into or sprayed onto the ball. When, now, this plastic material element is left to project somewhat from the sliding surface, a simply designed “spike” appears, on which the disc forming the plastic material can be attached.
An alternative embodiment may provide that the slide shoe has a locking ring, into which the disc is inserted. The disc is then not fixed radially inside, but radially outside. Also this is a simple way of securing the disc against a displacement in parallel with the sliding surface.
It is advantageous, if the locking ring is formed as an extension of the plastic material. In this case, no additional element is required to form the locking ring. The plastic material merely has to be somewhat extended. As the plastic material is fixed on the slide shoe anyway, this provides a sufficient fixing of the disc.
Preferably, the locking ring has at least one opening in the circumferential direction, said opening being connected to an annular groove, which is formed between the plastic material and the slide shoe. Water that has penetrated between the sliding surface and the plastic material can enter into the annular groove. As the annular groove is connected to the opening, the water can then escape from the contact zone between the plastic material and the sliding surface without building up excessive pressures.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention is described on the basis of preferred embodiments in connection with the drawings, showing:
FIG. 1 is a schematic section through a water hydraulic machine;
FIG. 2 shows a section through a piston of the water hydraulic machine with slide shoe;
FIG. 3 is a front view of the slide shoe;
FIG. 4 is an enlarged view of a section IV-IV according to FIG. 3 ;
FIG. 5 is an embodiment modified in relation to FIG. 4 ; and
FIG. 6 is a further embodiment modified in relation to FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A water hydraulic machine 1 has a housing 2 , in which a cylinder drum 3 is rotatably supported. The cylinder drum 3 is unrotatably connected to a drive shaft 4 .
Several cylinders 5 are located and uniformly distributed in the circumferential direction in the cylinder drum 3 . A piston 6 is movably guided in each cylinder. The cylinder 5 is connected to a valve plate 8 via a connecting socket 7 , the valve plate 8 interacting with a control plate 9 . During operation, the valve plate 8 rotates in relation to the control plate 9 .
The machine 1 is made as a pump having a delivery performance of 500 l/min and a delivery pressure of 60 bar.
The drive of the piston 6 occurs via a swashplate 10 . Each piston 6 is connected to a slide shoe 11 , the connection being made by means of a ball 12 , so that the slide shoe 11 can be tilted in relation to the piston 6 . By means of a pressure plate 13 the slide shoes 11 are kept to bear on the swashplate 10 . The pressure plate 13 again is supported on the cylinder drum 3 via a ball joint 14 and a spring 15 .
When the cylinder drum 3 rotates under the effect of a torque acting upon the drive shaft 4 , the pistons 6 are reciprocated, in a manner known per se, in the axial direction of the cylinder drum 3 by the slide shoes 11 bearing on the swashplate 10 . The machine then works as a pump. If the cylinders 5 are supplied with hydraulic fluid in the right position, the shaft 4 is rotated, and the machine works as a motor.
The machine 1 works with water as hydraulic medium. The inside of the housing 2 is usually also filled with water, even though this is not absolutely necessary. As known, water has no lubricating properties. In order to keep the friction between the swashplate 10 and the slide shoe 11 low, a friction reducing plastic material 16 is located between a sliding surface 17 of the slide shoe and the swashplate 10 . The friction reducing plastic material is especially a high-resistant thermoplastic plastic material on the basis of polyaryl etherketones, particularly polyetheretherketones (PEEK), polyamides, polyacetals, polyarylethers, polyethylene terephthalates, polyphenylene sulfides, polysulphones, polyether sulphones, polyether imides, polyamide imides, polyacrylates, phenol resins, like novolacquer resins or the like. The plastic material can be provided with a filling of glass, graphite, polytetra flourethylene or carbon, the fillings being particularly useful as fibres. Selecting one of these materials will provide excellent operation behaviour, when water is used as hydraulic fluid. Also the use of a DLC layer (DLC=diamond-like carbon) is possible, as described in DE 102 23 844 A1.
When larger pumps are concerned, as in the present case, there will be a risk, under unfavourable conditions, that the plastic material 16 is damaged, for example, small cracks may occur. In this case, water can penetrate in a contact zone 18 between the plastic material 16 and the sliding surface 17 . To prevent this penetrating water from building up an impermissibly high pressure between the plastic material 16 and the sliding surface 17 , it is provided, as appears from FIG. 4 , that the contact zone 18 is radially exposed on the circumference, that is, it is not covered or closed by any other elements. Water that has penetrated into the contact zone 18 can thus escape radially outwards. In particular, this is possible because practically no higher pressure prevails at the radial outside of the slide shoe 11 (in relation to the slide shoe 11 ). The sliding surface 17 has a recess 19 , which is provided with a radial undercut 20 . A projection 21 extending radially outwards from the plastic material 16 engages in this undercut 20 . Thus, the plastic material 16 on the sliding surface is not only secured against shear forces acting in parallel to the sliding surface 17 . It is also secured against axial forces, that is, forces acting in the movement direction of the piston 6 . Further, the projection has the advantage that also here a sealing is realised by the pressure acting upon the plastic material.
Between the ball 12 and the slide shoe 11 is located a plastic material element 22 , which is also made of a friction reducing plastic material. Also here, it is possible for water to penetrate between the ball 12 and the plastic material element. Preferably, the plastic material element 22 is made of the same material as the plastic material 16 . The plastic material element 22 is preferably made so that it is sprayed onto the slide shoe 11 .
At least in an area, in which it interacts with the pressure plate 13 , the slide shoe 11 is surrounded by a plastic material 23 . The plastic material 23 is also a friction reducing plastic material, preferably the same material as the plastic material 16 .
As appears from the FIGS. 2 and 3 , the plastic material 16 and the plastic material 23 are connected to each other via a total of four connections 24 distributed evenly in the circumferential direction. The connections 24 are located in radially extending grooves 25 , which are formed in the slide shoe 11 . The plastic material 23 and thus also the plastic material 16 are thus also secured against rotation in relation to the slide shoe 11 . In the positions, in which the connections 24 are located, the contact zone 18 is covered on the radial outside. This is, however, uncritical, as penetrated water has sufficient free space to escape from the contact zone 18 .
On the side adjacent to swashplate 10 , the plastic material 16 has a recessed area 26 . This area 26 has a surface corresponding to the pressure surface in the cylinder 5 . Via a channel 27 formed in the piston 6 , a section 28 of the channel also passing through the ball 12 and extending with a channel 29 through the plastic material element 22 into the recess 19 , the inside of the cylinder 5 is connected to the inner chamber of the cylinder 5 . Thus, the pressure acting upon the piston 6 also acts in the area 26 . As the surfaces, upon which the same pressure acts, are also equal, a hydraulic balance rules at the piston 6 . The force, with which the plastic material bears on the swashplate 10 , is therefore mainly determined by the force of the spring 15 .
FIG. 5 shows a modified embodiment of the slide shoe 11 , in which the same elements are provided with the same reference numbers as in FIG. 4 .
The plastic material 16 is now made as a disc 30 , which is merely attached to the slide shoe.
For this purpose the disc 30 has a central opening 31 . The plastic material element 22 is extended so that it projects with an extension 32 over the sliding surface 17 . The extension 32 engages in the undercut 20 , which gives an additionally improved stability. The extension 32 is penetrated by the section 29 of the channel 27 , so that the extension 32 is pressed against the slide shoe 11 in the axial direction by the pressure ruling in the cylinder 5 .
On the side facing the sliding surface 17 , the disc 30 has a further recess 33 , whose surface, however, is smaller than the surface of the area 26 . Even if water should penetrate between the disc 30 and the sliding surface 17 , the jacking force ruling in the area 26 via the pressure will be sufficient to hold the bearing of the disc 30 on the slide shoe 11 with sufficient force.
During operation, the forces acting upon the disc 30 will mainly be directed in parallel to the sliding surface 17 . These forces are then adopted by the extension 32 . Otherwise, the pressure plate 13 ensures that the disc 30 is retained between the slide shoe 11 and the swashplate 10 .
Also here the contact zone 18 is open towards the outside. In the embodiment according to FIG. 5 the contact zone 18 can even be open on its whole circumference.
FIG. 6 shows a further modification according to FIG. 4 , in which the same elements are provided with the same reference numbers.
In this case, the plastic material 16 is again made as a disc 30 , which can have the same dimensions and properties as in the embodiment according to FIG. 5 . The disc 30 is held in that the plastic material 23 has been extended from the circumference of the slide shoe 11 in the direction of the swashplate 10 and forms a locking ring 34 . Distributed on its circumference, the locking ring 34 has several openings 35 , which are connected to an annular groove 36 , which again surrounds the contact zone 18 .
Water that penetrates into the area between plastic material 16 and the sliding surface 17 can thus escape or be pressed radially outwards into the annular groove 36 . From here the water can flow outwards via the openings 35 into the inside of the housing 2 .
When maintaining a machine 1 having the embodiment according to FIGS. 5 and 6 , the disc 30 can merely be replaced without requiring replacement of other elements. This keeps the maintenance costs small and provides a simple way of extending the lifetime of the machine 1 .
While the present invention has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this invention may be made without departing from the spirit and scope of the present invention. | Motor start circuit for an induction motor, particularly a single-phase AC induction motor, with a main winding ( 4 ) and an auxiliary winding ( 5 ), which are supplied with current, particularly alternating current, via current supply connections ( 24, 25 ), and with a start switching device ( 15 ) serving the purpose of interrupting the current flow through the auxiliary winding ( 5 ) after the start of the motor, the start switching device ( 15 ) being connected to a control device ( 20 ) via a connector ( 18 ), the control device ( 20 ) being connected between the current supply connections ( 24, 25 ), and with a winding protection switch ( 28 ), which is normally closed and which opens on the occurrence of a fault. The invention is characterized in that the control device ( 20 ) is connected to the winding protection switch ( 28 ) via at least one further connector ( 22, 17 ), preferably via at least one further connector ( 22, 17 ) and the auxiliary winding ( 5 ). | 5 |
This application claims benefit of Provisional Application Ser. No. 60/100,938 filed Sep. 18, 1998.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to interferometry, and more particularly to a speckle interferometry apparatus and method that utilizes a scattering reference plate that can incorporate phase shifting.
Optical interferometers are known which make use of the interference phenomena known as the "speckle effect," the speckled pattern seen when laser light is used to illuminate a rough surface. This invention utilizes the speckle effect, but it offers significant cost and performance improvements over conventional apparatus and methods.
U.S. Pat. No. 4,850,693 teaches a compact and portable moire interferometer for determining surface deformations of an object; and U.S. Pat. No. 4,794,550 teaches a method of extending the measurement range of the moire reference beam techniques by constraining the reconstruction of a surface contour based on a prior knowledge about the surface. These moire methods require that some form of a grating be created or projected onto the surface of the specimen, perhaps by the use of coherent laser light.
The physics of this invention are distinctly different from moire techniques. This invention measures deformations, displacements, and strains of an object, but it does not employ the "moire effect," in that no grating is created on the specimen or in the optical system. Only the "speckle effect" is used.
Speckle interferometry is known for use in measuring strain in structural members and mechanical components. U.S. Pat. No. 4,591,996 teaches a method and apparatus for measuring strain in structural members utilizing a laser beam to illuminate a surface being analyzed and an optical data digitizer to sense a signal provided by the light beam reflected from the illuminated surface. The optical data digitizer is used to compare the signal received from the surface in a reference condition to subsequent signals received from the surface after surface deformation.
As is known in the art, data from the interference speckle can be used in several ways. While the specimen is stretched, the speckles translate indicating in-plane displacement and also vary in intensity indicating out-of-plane displacement. Due to the nature of materials, it can be assumed that changes from one speckle to an adjacent one are small and therefore linear. Because of this, contour maps of displacements and strains, both in-plane and out-of-plane can be constructed. The mathematical theorems and explanations of the recombination of object and reference beams are known in the art and are further described in a publication of the inventor, Optical Methods of Engineering Analysis, Cambridge University Press 1995, Gary Cloud, which is expressly incorporated herein by reference.
The speckle is itself an interference phenomenon. The formation of speckles in imaging systems can be described at any image region as the superimposition result of the coherent point spread functions for adjacent object points. The speckle created by imaging optics is referred to as a "subjective" speckle. The nature of the illuminated surface gives rise to two different classes of speckle patterns. One class is called the "fully developed" speckle pattern; it develops only from interference of light that is all polarized in the same manner. The speckle field itself will then be similarly polarized. Surfaces at which polarized light is singly scattered, such as matte finished metal, generally give rise to polarized speckle fields as do lightly scattering transmission elements such as ground glass. Matte white paint surfaces or opal glass, into which the light penetrates and is multiply scattered, depolarize the light and thus do not generate a fully developed speckle pattern. The brightness distributions of the two classes of speckle patterns differ substantially, but this difference is not important in the functioning of speckle interferometry systems.
The current invention requires the mixing of two speckle patterns, from two different scattering surfaces. When this occurs, the size of the speckles does not change appreciably, but their brightness distribution might be altered, depending on whether the patterns are mixed coherently or not (in this case coherently mixed). For the case in which the two original speckle fields are brought together coherently, the result is a third speckle pattern, differing only in detail from its two component patterns but whose size and statistical brightness distribution remain unchanged. This third speckle pattern is used in measuring motion, deformation, or strain of one of the reference surfaces.
Several different scattering surfaces are provided in the current invention. In the first, a reference surface is provided which is positioned adjacent to the surface of the specimen or surrounding the specimen. The reference surface and the specimen surface are illuminated by a beam of coherent light which has been passed through a spatial filter. The mixed speckle patterns scattered or reflected from these surfaces are recorded by the imaging system. The specimen is then subjected to a load, which causes displacement of the object's surface. This displacement causes a change in location and intensity of the various speckles in the mixed pattern. The changed patterns are again recorded by the imaging system. A computer connected to the camera captures the images and calculates displacements or strains on the object's surface.
In another embodiment of the current invention, a plate of at least partially transparent material is positioned between the laser illuminating source and the surface of the specimen. A portion of the light travels through the partially transparent reference and is scattered or reflected from the surface of the specimen. The mixed speckle patterns from the reflection off the transparent reference plate and the surface of the specimen are captured by the imaging system.
Optionally, any or all of the reference plates can be coupled to a system that translates the reference surfaces. As will be further described herein, the translation of the reference plate can be used to calculate the displacements of the surface of the specimen.
The disclosed speckle interferometry system is very good at measuring both in-plane and out-of-plane displacements. The processing of the data differs, however, depending on the displacement component sought. As the specimen is translated out of the plane of the specimen, the path lengths for the waves scattered from within a resolution element will change, causing a change of relative phase or intensity of a given speckle. As the specimen is translated in its plane, the speckle pattern is translated.
By including a capability which allows for the translation of one of the different scattering surfaces, the process known as "phase shifting interferometry" or "phase stepping interferometry" can be implemented with this invention. In this case, the scattering surface or reference plate is translated so as to determine the relative phase of a given speckle. This allows the imaging system to take brightness data for a given speckle and translate it to data that corresponds to out-of-plane displacement of the surface of the specimen. The system then uses the translation of the speckle pattern to precisely calculate the in-plane translation of the specimen surface. As such, the current system provides an efficient non-contacting system that can measure both in-plane and out-of-plane displacements and hence strains of the surface of a specimen.
As such, it is an object of this invention to provide a method and apparatus for measurement of deformations, displacements, and strains of the surface of structures of all kinds.
It is further an object of the present invention to measure the relative magnitude of displacements from an original position on different points on a surface of an object under stress.
It is yet another object of the present invention to provide an improved interferometry apparatus and technique for performing electronic speckle pattern interferometry in the analysis of motion, strain, and deformations of all kinds of structures, components, bodies and materials.
It is yet another object of the present invention to provide an interferometry apparatus which will be useful in the areas of engineering, manufacturing, medicine and natural science for making precise measurements without the necessity of heavy investment in equipment.
It is yet another object of the present invention to provide an interferometry apparatus using what is known as digital speckle pattern interferometry (DSPI) and video holography--video holographic interferometry (VHI). The apparatus is greatly simplified in comparison with traditional setups, and makes the method much more resistant to vibration and other sources of noise which tend to contaminate the results of DSPI.
It is yet another object of the present invention to provide an interferometry apparatus and method which maintains an excellent bandwidth characteristic of the traditional speckle interferometry approach.
It is yet another object of the present invention to provide an interferometry apparatus utilizing the speckle effect having a reference plate disposed before the specimen. The speckle interferometer includes a laser, a spatial filter/expander, a reference surface, a phase shifter, and recording media. Fringes occur upon making a pair of exposures of the interference patterns made before and after deformation of a rough surface. The relative magnitude of the displacements from the original position at different points on the surface can be determined from the position of the fringes. Alternatively, if phase shifting or phase stepping is used, then three or more images of the specimen are captured before and after loading, each image being taken at a different phase shift. The displacements are computed directly from the brightness data and may or may not be displayed as "fringes," displacement maps, or strain maps depending on application.
The foregoing as well as other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the apparatus of the invention;
FIG. 2 is a schematic diagram of an alternate embodiment of the invention;
FIG. 3 is further an alternate embodiment of the invention having a ring reflective plate; and
FIG. 4 is an alternate embodiment of the invention having a translucent reference plate.
DETAILED DESCRIPTION OF THE INVENTION
In general, the improvement taught by this invention, is to force ESPI, which is typically based on a Michelson interferometer configuration, to approximate a common path interferometer, while maintaining the positive features of the Michelson interferometer method.
The major key to the success of this approach is the incorporation of the splitter or reference plate which is placed close to the specimen. The plate serves to split off the reference beam from the main illumination or object beam close to the specimen. The only part of the optical path which is not "common path" is the small space between the reference plate and the specimen. In the configuration shown, interference fringes indicating displacements along the line of sight are obtained without further additions. The system can be modified to obtain other displacement components for many applications such as NDI.
Referring to FIG. 1, the apparatus for studying the deformation of the surface 28 of a specimen 25 under stress includes a monochromatic laser source 10 which illuminates the surface 28 of the specimen 25 through a spatial filter/expander 15 and an optional collimating lens 40. The surface 28 is assumed to be optically rough and therefore produce a speckle pattern when it is illuminated by the laser light. As such, surface 28 is shown to be irregular. Some of the light scattered by the surface 28 enters an optional field lens 45 to provide the input beam to the video camera 35. Further, the mono-chromatic laser source 10 illuminates through the spatial filter 15 the surface 18 of the reference plate 22. The spatial filter 15 converts the beam from the mono-chromatic laser source 10 into a spherical beam of light. The laser source 10 can be a standard HeNe laser, an ion laser, compact solid-state laser, or a laser diode. The reference plate 22 can be made of a partial mirror, a plain piece of glass, or glass that is etched to provide a partial scattering surface; or, finally, the reference plate can be opaque with a rough surface. The reference plate 22 does not need to be flat, especially if the plate 22 is unable to reflect speckles.
The reference plate 22 having front surface 18 can be placed close to the area of study so that it does not occlude the study area, but in a location so that it is illuminated by the laser beam. Some of the light scattered by the surface 18 impinges again onto the optional field lens 45 and into the video camera 35. The speckled patterns produced by the two beams are allowed to interfere to produce a resulting speckled image of the object surface 28. The two beams are combined and are recorded through a CCD camera 35. One skilled in the art will appreciate that other imaging systems utilizing traditional film cameras or video equipment are usable and equivalent.
The optical signals from surface 28 of object 25 are received by the camera 35 and transmitted to a signal extraction and processing module comprising analog to digital (A/D) and digital to analog (D/A) modules. The module converts the signal produced by the camera into a digital form, or the output of the system from digital to analog form. Other components of the system include an arithmetic logic unit, which performs arithmetic and logical operations, storage memories or frame buffers for storage of information during data extraction and processing, an array processor for performing certain operations needed during data extractions and processing with high efficiency, a computer for controlling the different components and performing some of the operations during data processing, and a video monitor for graphically depicting the output of the system.
In traditional speckle interferometry, the lack of a common path between the reference and specimen beams leads to significant errors or loss of data when vibrations, thermal gradients, or noise are present. This problem has greatly hampered use and acceptance of the powerful DSPI methods in factory and field environments. One primary benefit of the current system is that the reference and object beams travel almost identical paths, so that the advantages of common path interferometry is gained while retaining the advantages of DSPI. As such, the reference plate 22 should be as close to the specimen 25 as possible. This almost-common-path system significantly reduces the effect of vibration in the system and reduces the necessity for vibrational isolation of the specimen 25 or other components.
For the most precise measurements, the common techniques of "phase shifting" or "phase stepping" can be incorporated in a simple way. This is accomplished by simply translating the splitter plate along the line of illumination by use of a mechanical or piezoelectric driver which is coupled to the control computer 60. The measurement results can then be presented on a suitable display 70.
Phase shifter 30 is mechanically coupled to reference plate 22. By using the phase shifter 30 to move the reference plate 22 prior to and after the loading of the specimen 25, a contour map of the displacements of the object 25 can be produced. See Optical Methods of Engineering Analysis, previously incorporated herein by reference. The use of the reference plane 22 with no phase shifter in the system allows for the formation of a map of interference fringes representing changes of contour of the object.
Shown in FIGS. 1-4 is the angle theta 65. It should be noted that for convenience the angle theta is large in the diagrams, but in practice the angle theta 65 should be small to minimize errors. This is true for all embodiments of the invention.
FIG. 2 depicts an alternate embodiment of the current invention. Mono-chromatic laser 10 projects a beam through spatial filter/expander 15 onto the specimen 25 having a reference surface 28. The spatial filter 15 further projects the laser beam on to the surface 18 of reference 22. The light scattered by the surface 28 of specimen 25 and surface 18 of reference plate 22 produces a speckle pattern as was described above. The speckled image is captured by video camera 35 and is downloaded through a frame grabber to computer 60.
FIG. 3 shows an alternate embodiment for the current invention. The reference plate 24 is in the form of an annular plate that is open in the center. This reference or reflecting plate 24 is used to "frame" the view of the specimen 28 being observed. An advantage of this plate when incorporated into a system is to provide a means to enclose the system while providing a large reflective reference surface. The plate 24 can be further coupled to a phase shifter 30.
FIG. 4 shows yet another embodiment of the current invention. The laser 10 projects a beam through a spatial filter/expander 15 and further through the optional collimator lens 40. Disposed between the collimator lens 40 and the specimen 25 is a splitter or reference plate 20. Mechanically coupled to the splitter or reference plate 20 is a phase shifter 30. The collimated beam is divided into two components. The first or object beam is projected on to the surface 28 of specimen 25. The second component or reference beam is reflected off of the splitter or reference plate 20 and through the optional field lens 45 to video camera 35. The object beam is reflected from the specimen surface 28 and travels back through the splitter or reference plate and through the optional field lens 45 into video camera 35. In this embodiment, the noted feature is that the splitter or reference plate 20 are directly in the path of the optionally collimated beam of light. As previously mentioned, the video signal from camera 35 is captured by frame grabber and processed in computer 60.
The preferred method for the use of the speckle interferometer as previously described is as follows. The laser 10, via the interferometric apparatus, illuminates the specimen 25. An image of the specimen and corresponding speckle pattern is captured by the video camera 35 and processed by the computer 60. While the specimen 25 is being simultaneously illuminated by the laser 10 and observed by the video camera 35, the specimen 25 is subjected to a load. Changes in the speckle pattern caused by slight movements of the specimen surface 28 are recorded by the video camera 35 and processed by the computer 60. Again, the measurement and analysis results can be presented on a connected display 70.
The foregoing discussion discloses and describes exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims. | A speckle interferometer for measuring displacement deformation, motion or strain of an optically irregular surface of a specimen is disclosed. The interferometer includes laser, a spatial filter for receiving radiation from the laser and converting it into a spherical beam and projecting it to the optically irregular surface of the specimen is located. A reference plate located in or near the second location for reflecting or scattering some or all the radiation to a fourth location, said reflection interfering with the reflection from the optically irregular surface to form a pattern of speckles. A camera and imaging system for measuring displacement and changes in intensity of the speckles is also included. | 6 |
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C. 2457).
PRIOR ART
Synthetic plastic optical components are generally made from organic resins such as acrylics, polystyrenes, polycarbonates and the like. Although they possess several advantages over the more traditional glass and crystalline materials in terms of weight, resistance to thermal shock and mechanical stresses, cost, etc., they are particularly vulnerable to abrasion, scratching and environmental conditions. This vulnerability often results in impairment, if not complete destruction of their optical capabilities.
Numerous attempts have been made to correct these defects. These attempts have often consisted in applying some scratch resistant layer of material on the components by conventional methods which have included dip coating, electronic beam coating, ultraviolet polymerization and varnishing of the components' surface with a solution of the coating material followed by evaporation of the solvent. While some progress has been accomplished in these manners, the compositions and processes employed have tended to create additional problems with respect to cost, uniformity, adhesion, orientation and directionality requirements between the substrate and the coating composition. To illustrate the shortcomings of the methods of the art, one can consider the dip coating process which consists in immersing a substrate into a coating liquid, removing it from the liquid and drying it. One problem with this process is that the thickness of the resulting film is virtually beyond control. Furthermore, not only do films so prepared not show any durability at thicknesses under about 1 micron, but also they are generally too thick and not sufficiently uniform for use as optical coatings on a substrate having the complex geometry of a lens. Thick coatings (> 2 microns) in fact never exhibit both abrasion resistance and anti-reflective properties over the entire range of the visible spectrum (˜ 4000 to 7000 A).
Recent developments in the art of coating plastic substrates have involved the utilization of plasma or glow discharge polymerization of various organic monomers which include organo-silanes and perfluorobutene-2. These processes have yielded thin uniform optically clear coatings which may possess, depending on the monomer selected and the conditions employed, various desirable properties such as abrasion resistance and antireflectivity.
Thin inorganic coatings have also been applied to thermoplastic elements to achieve increased scratch or abrasion resistance. Thus, Cormia (U.S. Pat. No. 3,458,342), Onoki (U.S. Pat. No. 3,811,753) and Chang et al. (U.S. Pat. No. 3,991,234) all disclose applying a vitreous coating on plastic lenses by simple evaporation, preferably in a vacuum. Dobler (U.S. Pat. No. 3,984,581) and Addis (U.S. Pat. No. 3,953,652), on the other hand, suggest coating a plastic lens under vacuum conditions, using electron bombardment to vaporize a material which is glass in the Addis process and silicon oxide in the Dobler process. The use of elevated temperatures is avoided.
An object of the present invention is to provide a new type of inorganic coating for optical or other thermoplastic substrates. Another object is to provide an intermediate coating which will enhance the adherence of certain organic polymeric materials to said substrates. A further object is to provide a material which can be plasma coated simultaneously with suitable organic monomeric substances to improve the properties of the resulting polymeric coating.
SUMMARY OF THE INVENTION
It has now been discovered that these and other objects which will become apparent as the process of the invention is described, can be accomplished by subjecting a plastic substrate to a boron trifluoride low temperature plasma. The process may be used to form a single inorganic coating of the material on the plastic surface or to form a coating which combines the boron trifluoride with an organic polymeric coating substance. Alternately, the coating obtained by exposure to a boron trifluoride plasma may serve as an intermediate binding layer between the plastic and an outer organic polymeric coating.
DETAILED DESCRIPTION
The coating processes that constitute the present invention may be carried out in any of the plasma reactors described in U.S. Pat. No. 3,847,652. The configuration actually employed for the preparations disclosed in the present specification involved an internal electrode parallel plate arrangement deposition system, with the deposition taking place within the plasma between the electrodes. The reactor, 25.4 cm in diameter and 30.5 cm long, was connected to a liquid nitrogen trap in train with a vacuum pump. Except as shall be otherwise noted, the reactor and its accessory equipment were set up and operated substantially in the manner described in U.S. Pat. No. 3,847,652.
The plastic material to be coated, e.g., polished cast sheet stock of a bisphenol A-phosgene polycarbonate resin, can be cleaned before coating, although this was found not to be necessary in the case of boron trifluoride coating due to the high adhesion of that substance to the plastic substrate. In any event, the cleaning, when done, generally consisted in (1) dipping the plastic pieces in Freon solvent T-WD 602, a water dispersion of trichlorotrifluoroethane having an initial boiling point of 47° C at 760 mm; (2) rinsing them in a second solvent, e.g., trichlorotrifluoroethane; and (3) degreasing them in vapors of the latter liquid. Other established techniques such as pretreatment of the plastic surfaces with water, ammonia, oxygen and the like can also be advantageously employed to enhance the properties of some of the films that can be produced by the process of the invention.
The coating process is initiated by positioning the plastic substrate near the center of the reactor in an aluminum frame supported by Teflon legs. The reactor is evacuated to a background pressure 0.67 N/m 2 of mercury and the coating agent allowed to flow in at a suitable rate and pressure. Radio frequency power, e.g., at 13.56 MH z , is then applied either continuously or, if desired, in a pulsed mode, for example in an on-off cycle of 1.5 millisecond. Although a large number of power settings and pressure combinations can be employed to achieve some coating of BF 3 on plastic substrates, preferred pressures and power settings range between about 9.3 to 20 N/m 2 and 30 to 75 W, respectively.
The boron trifluoride coating obtained in this manner can serve as the sole protection of the plastic surface or, alternately, it may serve as a base upon which organic polymeric coatings are deposited to augment the protection afforded to the plastic surface and to increase the adhesion of said organic polymeric coatings to the plastic surface. These organic coatings may be applied in any conventional manner but plasma deposition is preferred for the obtention of thin transparent uniform films of controlled thickness. Among the materials that can be used to overcoat the boron trifluoride film are: perfluorobutene-2; organosilanes such as vinyltrichlorosilane, tetraethoxysilane, vinyltriethoxysilane, hexamethyldisilazane, tetramethylsilane, vinyldimethylethoxysilane, vinyltrimethyoxysilane, tetravinylsilane, vinyltriacetoxysilane, and methyltrimethoxysilane; ethylene-nitrogen gas mixtures, and the like. These materials may be employed singly or in any combination desired.
A further alternative to employment of the boron trifluoride coating as an intermediate film between the plastic surface and the outer organic polymeric coating, is to combine the boron trifluoride with the organic monomer gas and carry out the deposition of a film with that mixture.
Finally, any coating thus obtained can be further treated in a plasma of inorganic gas or vapors, including nitrogen, oxygen, ammonia and the like, to convert as much of the coating substance as possible to oxides, nitrides and other appropriate resistant linkages.
Examples will now be provided to illustrate specific non-limiting embodiments of the processes just described.
EXAMPLE 1
A piece of optically clear polymethylmethacrylate was placed in a boron trifluoride plasma in an apparatus of the type already described. The pressure of boron trifluoride, the lone reactant, was set at 9.3 N/m 2 and the power, at 50 W. Under these conditions, a clear film was deposited onto the substrate at a rate in the order of about 0.25 to 0.50 Angstrom per second. The film, even at thicknesses as small as 600 A for example, exhibited a strong blue color, indicating an index of refraction smaller than that of the polymethylmethacrylate (1.492 N B ) with good uniformity. Adhesion of the film to the substrate was excellent as determined by tape pull test in accordance with MIL-SPEC C675A. The film however lacked durability in that on wiping with lens cleaning tissue, severe scratching and smearing occurred. This latter shortcoming as well as the low deposition rate achieved can be improved by varying the pressure and the power employed. The film obtained is advantageously used as an intermediate layer to increase the adherence of polymerized organic films such as polyperfluorobutene-2 to the plastic surface.
EXAMPLE 2
In this preparation, boron trifluoride was mixed with nitrogen gas in a ratio of 2 to 1. The total pressure was about 20 N/m 2 and the power at 35-75 W. A blue film was obtained and, again, at a very low deposition rate. Infrared spectrum data showed absorption at the B-N bond wavelength. Adhesion of the film to the substrate was very good while durability was poor. The thickness of the film was measured by interferometry. It was thus determined that at 35 watts of power, the deposition rate was 0.62 A per second. The coating showed signs of incipient opacity at power settings greater than 60 watts.
EXAMPLE 3
In this preparation, boron trifluoride was deposited in combination with perfluorobutene-2. The total pressure of the gas mixture was 20 N/m 2 and their ratio, 2 to 1 respectively. The power used was 50 W. Under these conditions, the rate of deposition increased to about 2 A/second and the film obtained showed good adhesion and moderate durability. The coating however did not pass a hand cleaning test with lens tissue.
A comparison of infrared spectra taken from the present film and from one prepared with perfluorobutene-2 as the sole reactant indicated that while both coatings showed one absorption peak at 9 μ (C-F), that obtained from the film of the present example was considerably larger. Incorporation of boron was also evident.
EXAMPLE 4
The plasma coated plastic substrate of Example 3 was given a nitrogen post-treatment which consisted in evacuating the apparatus to the background pressure and creating a nitrogen plasma for 500-700 seconds at a pressure of 13.3 N/m 2 and a power of 50 W. The durability of the treated film was markedly improved. The product successfully passed the tape pull test for adhesion. It was also free of degradation after having been subjected to 20 and 40 rubs with an eraser under 2.2 psi pressure, as specified by MIL SPEC-C-675A. This data, according to the standard procedure, was obtained by visual inspection of the coating, as the specification requires. Further, inspection under 40 magnification and white-light illumination failed to detect any degradation. Also, immersion for up to 24 hours in distilled water or in Freon TF (trichlorotrifluoroethane) and acetone showed the coating to be insoluble.
Although the present invention has been disclosed generally in terms of its preferred parameters and embodiments, it will be understood that many variations in compositions and processes can be carried out by the man skilled in the art without departing from its spirit and scope as defined by the following claims. | Plastic surfaces can be improved physically and optically by treating them with a plasma of boron trifluoride. The trifluoride can be the sole reactant or be part of a mixture also containing an organic monomeric substance such as perfluorobutene-2 or an organosilane. The boron trifluoride-containing coating can also serve as an intermediate coating between the plasticl surface and a plasma deposited organic polymer. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10/425,428 filed Apr. 29, 2003, which claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 60/376,490 filed Apr. 30, 2002, the disclosures of which are hereby incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention generally relates to hydroxycitric acid (HCA) and its salts, and more specifically to water soluble mixtures of calcium and potassium salts of HCA, and to methods of making the calcium and potassium salts and mixtures thereof. The invention also relates to the use of such compositions as nutraceuticals or dietary supplements.
[0005] 2. Description of Related Art
[0006] The fruit acid hydroxycitric acid (HCA) is a naturally occurring fruit acid found in the rinds of the fruit of Garcinia cambogia, Garcinia indica and Garcinia mangostana . The identification of the acid, methods of isolation and analytical methods for estimating concentration were elucidated by Y. S. Lewis et al. in METHODS OF ENZYMOLOGY (Academic Press, N.Y. (1969)). Hydroxycitric acid has been investigated for its nutritional importance, and studies have shown that pharmacologic amounts of HCA can accelerate metabolism, leading to weight loss, improved glucose metabolism, can suppress the appetite, and can produce other physiological effects. Various researchers have evaluated HCA for its weight control properties, fat burning properties, lipid level lowering effect, appetite regulation, metabolic rate increase, and other effects. A number of U.S. patents have been granted based on the results of those studies and on various methods of extracting HCA from the Garcinia fruit. For example, U.S. Pat. No. 5,656,314 (Moffett et al.) describes a certain hydroxycitric acid concentrate and food products prepared therefrom. By that method, free hydroxycitric acid having a concentration ranging from 23 to 54% in aqueous media is obtained.
[0007] It has been found, however, that the free acid form of HCA is unstable, forming lactones which generally do not possess the desired bioactivity. Therefore, food preparations that incorporate the free acid in liquid form will not provide the full benefit of the functional product (i.e., HCA) in the final preparation. The liquid form of free HCA tends to be unstable during storage, so it may not be the optimal form for incorporation of HCA in food products.
[0008] In U.S. Pat. No. 5,783,603 (Majeed et al.) administration of potassium hydroxycitrate for the suppression of appetite and induction of weight loss is disclosed. This salt is prepared by treating Garcinia -extracted HCA with methanolic potassium hydroxide, and the potassium salt of HCA is dried under vacuum. In powder form, potassium hydroxycitrate is very hygroscopic in nature, and typically has very poor keeping qualities. Another drawback of this type of preparation is that the assay of HCA may be too low for some applications.
[0009] U.S. Pat. No. 6,160,172 (Balasubramaniam et al.) describes certain compositions containing soluble double metal salts of hydroxycitric acid. Group IA and IIA (i.e., Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba and Ra) salts of HCA are formed as powders after precipitating the Garcinia -extracted HCA solution with polar solvents. This process can contain solvent residues and high levels of chlorides in the final product, however. Potential contaminants such as chloride and oxalic acid limit application of the product where the original taste, color and fragrance of the base material, such as a food or beverage, cannot be compromised. Another drawback of a method such as this is that it can be quite cumbersome due to the number of steps.
[0010] U.S. Pat. No. 6,207,714 (Clouatre et al.) describes the use of commercially available pharmaceutical preparations of a calcium, magnesium, potassium or sodium salt of hydroxycitric acid for increasing a person's glucose metabolism.
[0011] U.S. Pat. No. 6,221,901 (Shrivastava et al.) describes a method of making a purified magnesium hydroxycitrate preparation, and discusses its use as a medicament for treating cardiovascular disease. No food supplementation or body weight effects were noted in rabbits that were fed the magnesium hydroxycitrate preparation.
[0012] It is well known that hydroxycitric acid is unstable in its free acid form, so it is typically prepared as its salt for stability and for use in any of the applications mentioned above. Some commercially available and commonly used salts include calcium salts of HCA standardized for 50%, 55% and 60% levels of HCA. The potassium salt form is also readily available as a 45%, 50%, 55% and 60% salt. One drawback of typical commercially available calcium HCA salt preparations is that they are not very soluble in water. This severely limits its applicability for use in drinking water, beverages, ice cream, candies and in food. Another disadvantage of most calcium salts of HCA that are available today is that they typically deliver only a maximum assay of 60%, thereby limiting the total availability of HCA in any composition.
[0013] The potassium salt of HCA overcomes the major disadvantage of the calcium salt (i.e., insolubility) due to the good water solubility of the potassium salt of HCA. However, due to the high level of potassium in the salt, the potassium salt leaves a strong pungent taste of potassium. This tends to interfere with the taste profile of the food, or beverage, which limits the amount of potassium hydroxycitrate that can be incorporated into a food to levels that are below the amount needed to achieve the desired functional effects of the HCA in the recipient. Another disadvantage often encountered with the potassium salt is a tendency to form lumps during storage due to its highly hygroscopic nature, thus reducing the shelf life of the HCA salt. Commercial manufacture is also made cumbersome due to the undesirable hygroscopic property. The assay of HCA in conventional potassium hydroxycitrate preparations is also typically low, at 60% or less.
[0014] PCT Published Patent Application No. WO 99/03464 (Raju) describes certain hydroxycitric acid compositions containing 40% or more HCA, 5-13% calcium and about 9-20% potassium or about 5-10% sodium for use as dietary supplements and food products to reduce body weight. Hydroxycitric acid lactone content is said to be less than approximately 4%. A synergistic relationship between the calcium content and the potassium (or sodium) content is described. An acetone refining step is employed in preparing the HCA extract. As previously mentioned, potentially toxic residues of chemicals employed during manufacture may be a concern in some HCA compositions intended for consumption.
[0015] There exists a need for a pure, stable, highly soluble formulation of HCA salts that addresses the above-identified problems and eminently lends itself for incorporation into consumables such as drinking water, beverages, nutraceuticals, power bars, ice cream, and the like. Such products are useful as diet aids to help with weight reduction. Also needed is a better and more commercially attractive way to prepare such HCA salt formulations.
BRIEF SUMMARY OF PREFERRED EMBODIMENTS
[0016] Improved methods of making compositions hydroxycitric acid salts that are very pure, water soluble and stable in solution and during storage are provided in accordance with certain embodiments of the present invention. Also provided are methods of using the resulting compositions as nutraceuticals, dietary supplements, functional additives in foods, beverages and even in clear, essentially tasteless drinking water.
[0017] In accordance with certain embodiments of the present invention, a simple, compact process for the production of a stabilized formulation of hydroxycitric acid salts is provided, preferably in very pure form. For the purposes of this disclosure, the term “high purity” refers to a product having a hydroxycitrate content of at least 70-75% and a lactone content of no more than 0.5% (by weight of the total weight of the product).
[0018] Certain embodiments of the invention provide a method or process for making a hydroxycitric acid salt composition that is eminently suited to commercial-scale manufacturing. The method includes preparing an aqueous extract of Garcinia cambogia or Garcinia indica fruits and extracting that aqueous extract with a liquid quaternizing agent to yield a quaternizing agent extract containing hydroxycitric acid. In preferred embodiments the quaternizing agent (QA) is a trialkylamine in which the alkyl groups are octyl, caprylyl, isooctyl, lauryl and decyl, or a combination of any of those groups. In certain embodiments the QA is tricaprylylamine. The preparation method excludes the use of organic polar solvents such as acetone, methanol, ethanol, propanol, isopropanol, and the like, which might leave undesirable or potentially toxic residues in the product.
[0019] In certain embodiments the method comprises treating the QA extract with potassium hydroxide or sodium hydroxide and recovering a potassium hydroxycitric acid salt solution or a sodium hydroxycitric acid salt solution. In certain embodiments the method comprises treating the potassium or sodium hydroxycitric acid salt solution with activated charcoal such that a decolorized potassium or sodium hydroxycitric acid salt solution is obtained.
[0020] In some embodiments the method includes preparing a decolorized sodium hydroxycitric acid salt solution and treating it with a calcium salt (calcium chloride, for example) such that a heterogeneous slurry comprising insoluble calcium hydroxycitric acid salt is obtained. Some embodiments include adjusting the pH of the slurry to a pH in the range of 9.5-11 such that a calcium hydroxycitric acid precipitate is obtained. In some embodiments the precipitate is then washed and dried to provide a powder comprising pure calcium hydroxycitrate.
[0021] In certain embodiments, the method includes a) preparing a calcium salt of hydroxycitric acid, as described above; b) preparing an aqueous solution comprising the potassium salt of hydroxycitric acid, as described above; c) dissolving the calcium HCA salt in the potassium HCA solution to provide a potassium-calcium hydroxycitric acid salt solution; and d) drying the potassium-calcium hydroxycitric acid salt solution to yield a powder comprising a mixture of potassium and calcium hydroxycitric acid salts. A preferred way of drying the solution is spray drying, although another technique that is capable of providing an equivalent powder could be substituted.
[0022] In certain preferred embodiments the method includes combining the calcium hydroxycitric acid salt and the potassium hydroxycitric acid salt solution in a molar ratio in the range of about 1.9-2.9 calcium hydroxycitric acid salt: about 0.9-1.4 potassium hydroxycitric acid salt. In a more preferred embodiment equivalent molar amounts of the potassium hydroxycitric acid salt solution and the calcium salt of hydroxycitric acid are combined.
[0023] In some embodiments the method includes reducing the resulting powder to about 80 mesh size particles. This may be done by pulverizing or any other suitable method that produces about the same size particles.
[0024] In still other embodiments of the present invention, a hydroxycitric acid salt composition is provided which is the product of a method as described above. In some embodiments, the product comprises a potassium or sodium hydroxycitric acid salt composition. In some embodiments the product comprises a calcium hydroxycitric acid salt composition which contains about 72 wt % hydroxycitrate, about 17 wt % calcium, and about 10 wt % water.
[0025] In another embodiment the composition contains defined proportions of a potassium salt of HCA (e.g., potassium, 11-18%) and a calcium salt of HCA (e.g., calcium 5-10%) to yield a stabilized (i.e., non-hygroscopic, readily soluble) mixture. One highly preferred composition prepared as described above contains 72% HCA, 9% calcium, 14% potassium, 4% structural moisture, 0.5% sodium and 0.5% lactone. Percentages are calculated on the basis of gravimetric quantities of each component in the total salt. In preferred embodiments the potassium HCA salt and the calcium HCA salt are combined as a physical mixture of the two salts, in contrast to some other HCA salt compositions that contain calcium and potassium in a single salt structure (e.g., a double salt).
[0026] In certain embodiments the composition contains 70-75 wt % hydroxycitrate, 7.5-9.5 wt % calcium, 12-15 wt % potassium, no more than 0.5 wt % of the lactone form of hydroxycitric acid, and up to 0.5 wt % moisture. In some embodiments the composition has a room temperature solubility of at least 5 g in 100 mL water, and is capable of yielding a clear, tasteless, transparent solution in water. With this high solubility some embodiments of the compositions are especially suited for use in a variety of food items, such as beverages, ice cream, candy and drinking water. Food or drinks containing the preferred calcium-potassium HCA composition avoid the unpleasant pungent taste of potassium that is typically associated with other potassium HCA-containing products. Such HCA salt containing products are potentially effective dietary aids for use in weight loss programs.
[0027] Accordingly, certain embodiments of the invention provide a precipitate-free aqueous solution that contains an above described potassium and calcium HCA salt composition. In other embodiments a food, beverage or dietary supplement is provided that contains an above described potassium and calcium HCA salt composition. In preferred embodiments, the product is free of excessive calcium, potassium, oxalic acid, chlorides or other salts that might potentially detract from the original taste, color or fragrance of the HCA composition or the food, beverage or supplement containing the HCA composition.
[0028] In still other embodiments of the present invention, a method of reducing body weight is provided. The method includes administering to an individual in need of weight reduction an effective amount (e.g., up to 5 g/kg of body weight of the composition per day).
[0029] These and other embodiments, features and advantages of the present invention will become apparent with reference to the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a proton NMR spectrum of the mixed salts of calcium and potassium hydroxycitric acid prepared in accordance with one embodiment of the present invention.
[0031] FIG. 2 is a C 13 —NMR spectrum of the mixed salts of calcium and potassium hydroxycitric acid prepared in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] The process for making a very pure potassium-calcium HCA salt mixture generally includes preparing an aqueous potassium HCA salt solution, preparing a dried pure calcium HCA salt, and then combining the dry calcium HCA salt with the liquid potassium HCA salt solution, as described in more detail as follows:
Preparation of Potassium Salt of Hydroxycitric Acid
[0033] Garcinia cambogia or Garcinia indica fruits are procured and extracted with demineralized water equivalent to 12 to 20 volumes on the fruit, and the resulting juice is filtered to remove all the suspended plant materials. The clear, filtered juice is then loaded on a stainless steel column, preferably having a tubular structure. From the bottom of the tube, a quaternizing agent (QA) such as a liquid trialkylamine is passed in a counter current manner at a predetermined rate so as to have a QA residence time of 1 to 10 min. The desired residence time can be achieved by controlling the flow at the inlet of the column. The upper (QA) extract is continuously removed and taken into a vessel for the recovery of the Garcinia acid. Preferred trialkylamines have octyl, caprylyl, isooctyl, lauryl or decyl groups or a combination of any of those groups, as the amine substituents. Tricaprylylamine is especially preferred.
[0034] The collected QA extract layers are combined and treated with a solution of 0.5 N potassium hydroxide under agitation for a period of time ranging from about 10-100 minutes. After extracting the solution for the desired time the layers are separated. The clear bottom layer containing the potassium hydroxycitrate is removed and treated with activated charcoal to remove the coloring impurities. The amount of activated charcoal employed in the treatment depends upon the amount of color in the extract. During activated charcoal treatment the solution needs to be heated to a temperature in the range of about 75-95° C., preferably about 90° C., and maintained at that temperature for about 30 to 80 minutes, preferably about 60 minutes, and then hot filtered. The resulting clear filtrate contains the potassium salt of hydroxycitric acid of a strength varying from 0.3N to 0.5N in aqueous solution. This solution is reserved for mixing with other ingredients before stabilization and spray drying.
Preparation of Calcium Salt of Hydroxycitric Acid
[0035] For making the calcium salt of hydroxycitric acid, the above-described process is modified in the following manner. A fresh lot of fruits is extracted with demineralized water and filtered to remove all the suspended plant materials, the clear filtered juice is loaded on a stainless steel column and extracted with the quaternizing agent as previously described. The collected QA extract layers are combined and treated with a solution of 0.5N sodium hydroxide under agitation for 10-100 minutes. After extracting the solution for the desired time, the layers are separated. The clear bottom layer containing the sodium hydroxycitrate is removed and treated with activated charcoal to remove the coloring impurities. Again, the amount of activated charcoal used can vary, depending upon how extensively colored the extract is. During the activated charcoal treatment the solution is heated and then hot filtered, as described above. The clear filtrate contains the sodium salt of hydroxycitric acid of a strength ranging from 0.3N to 0.5N in aqueous solution. Preferably the QA layer is recovered and recycled for use in subsequent extractions.
[0036] The solution containing the sodium salt of hydroxycitric acid is treated with a stoichiometric amount of calcium chloride solution in demineralized water. The resultant solution is mixed for 30-120 minutes. Initially a lean precipitate appears which on standing becomes thick. The pH of the heterogeneous slurry is adjusted to 9.5 to 11, preferably about pH 10, using a 10% sodium hydroxide solution. The slurry is then filtered and washed with demineralized water to remove all adhering salts. The washings are monitored for chlorides, and washing is continued until the filtrate is chloride free. The wet cake is dried in a vacuum oven at a temperature between 70° C. and 100° C., preferably at 85° C. The resultant dried powder, which is preferably at least 99% pure salt of calcium hydroxycitrate, is pulverized to obtain a uniform powder of 80 mesh size (about 0.177 mm sieve opening. See Tyler Standard Screen Scale, in C. J. Geankoplis, T RANSPORT P ROCESSES AND U NIT O PERATIONS , Allyn and Bacon, Inc., Boston, Mass., p. 837).
Combination of the Potassium and Calcium Salts of Hydroxycitric Acid
[0037] Preferably an equal quantity (stoichiometric to the acid content) of the potassium salt solution prepared as described above) and the dry calcium salt are mixed to yield a clear liquid. The resultant liquid is treated with activated charcoal again, if necessary, to provide a colorless solution. This solution is then spray dried to yield a free flowing white powder. The product is characterized by good water solubility, stability during storage and reduced hygroscopic property compared to most conventional hydroxycitric acid salt preparations. Moreover, the calcium stabilizes the potassium component to avoid the problems commonly associated with the hygroscopic nature of potassium hydroxycitrate. The potassium-calcium HCA salt combination resists clumping of the dry mixture, and overcomes many of the disadvantages of prior HCA salt preparations. This stabilized potassium and calcium HCA salt composition is suitable for use in drinking water, beverages, ice cream, candy, power bars and other food items without materially changing the original flavor, color and fragrance of any of the principal food items, and without imparting a noticeable pungency or bitterness that is usually associated with potassium-containing HCA preparations. The product was analyzed for the presence of residual quaternizing agent and none was detected.
[0038] While various compositions containing the salts of HCA are known, the present inventors discovered unexpectedly good results when equal amounts (with respect to HCA content) of the potassium and calcium salts, prepared as described above, are combined in the product (i.e., a 2:1 molar ratio of (K)HCA:(Ca)HCA). This particular combination of calcium and potassium salts was found to be superior for use in aqueous solutions of the product. Although the 2:1 molar ratio provides a superior, highly preferred product, it was determined that is also possible to obtain unexpectedly good hygroscopic property, solubility, stability, taste, and other desirable properties using molar ratios in the range of 1.9-2.9 (K)HCA:0.9-1.4 (Ca)HCA. Outside of this range the combined salts lack the advantageous combination of desirable properties that make it better suited for inclusion in food products, dietary supplements, nutraceuticals and especially for use in clear drinking water or other beverages in which cloudiness or precipitates are unacceptable. The special advantages or criticality of this range of molar ratios, especially the stoichiometric 2:1 ratio described above, has not previously been recognized.
Example 1
Calcium Salt of Hydroxycitric Acid
[0039] 500 g of salt-free Garcinia cambogia fruit rinds were extracted with 700 ml of hot deionized water at 70 to 75° C. for 20 minutes in a percolator. The spent rinds were subsequently extracted with 400 ml of hot deionized water twice, and all the extracts were combined and filtered through nylon cheesecloth. The clear filtrate measured 1000 ml, having an acid content of 6.5% (as hydroxycitric acid). This solution was taken in a tubular glass or stainless steel column, with a bottom liquid sparging arrangement, connected with a non-return valve. Through the bottom line 400 g of tricaprylyl amine, which is a liquid quaternizing agent (QA), was pumped using a dosing pump. The flow rate of the liquid was adjusted in such a manner as to achieve a column liquid contact time of 1 minute (approximately 3 ml/min of tricaprylyl amine). The top extract was removed and taken into a container. The QA layer was washed with deionized water and the wash water discarded.
[0040] 37.5 g of sodium hydroxide pellets was dissolved is 400 ml of water. This alkali solution was mixed with the QA extract and stirred for 30 minutes. Layers were separated and the top QA layer was taken for reuse after a water wash to remove the acidity. The alkaline extract was treated with 75 grams (g) of activated charcoal and the solution was heated to 90° C. The solution was filtered clear and treated with calcium chloride solution (52 g in 100 mL water). The pH of the solution was adjusted to 8.5 using 5% sodium hydroxide solution, the resulting precipitate was filtered, washed with deionized water free of chlorides and dried in a vacuum oven at 70° C. The weight of the resulting compound was 70 g. High performance liquid chromatography (HPLC) analysis was employed in determining the chemical makeup of the resulting calcium hydroxycitric acid salt. Briefly, the procedure included subjecting the sample to ion exchange chromatography, both quantitative and using reverse phase C-18 columns. The free hydroxycitric acid released by elution through the cation exchange resin was measured by HPLC according to the procedure described by P. Kucera et al., D IFFERENTIAL F RONTAL A NALYSIS OF C ARBOXYLIC A CIDS , J. Chromatography (1981) 210:373-388), the disclosure of which is incorporated herein by reference. The hydroxycitric acid content was found to be 72.5%, as indicated in Table 1.
[0000]
TABLE 1
PROXIMATE ANALYSIS
Hydroxycitric acid content:
72.5% by HPLC
Calcium content:
17.22% by atomic absorption
Water content:
10% by TGA
TOTAL:
99.72%
Example 2
Potassium Salt of Hydroxycitric Acid
[0041] The above procedure was repeated with a fresh lot of Garcinia fruit, except that instead of using NaOH, the QA extract solution was treated with 61.9 g of potassium hydroxide (85%) in 400 ml of water. The extracted potassium hydroxide layer was treated with activated charcoal at 90° C. and the resulting filtrate was clear. This solution contained about 82.3 g of potassium hydroxycitrate.
Example 3
Combined Potassium-Calcium Salts of Hydroxycitric Acid
[0042] 50 g equivalent of the hydroxy citric acid—potassium salt solution from Example 2 was taken into a glass beaker fitted with a stirring arrangement. To this solution, 43 g of the dried calcium salt from Example 1 was added and the mixture was stirred to yield a clear solution. The resultant solution was spray dried to yield a salt of hydroxycitric acid with the following analysis: potassium content 11% to 18%, calcium content 5% to 12%, structural moisture 3% to 5% and hydroxycitric acid content 70% to 76%. The sodium content was less than 0.5% and lactone less than 0.5%. The combined salt has a solubility of 5 g in 100 mL of deionized water at room temperature. This salt composition is tasteless and white in color. A solution of 5 g in 100 ml of de-ionized sterile water was subjected to an accelerated storage study chamber for 2 months. After 2 months it was observed that the salt did not precipitate out. The solution retained its clarity. Therefore, it can be safely concluded that, after dissolution in water, the salt composition does not decompose during storage.
Structural Analysis of the Calcium-Potassium Hydroxycitric Acid Salt
[0043] A detailed structural study of the resulting representative product was performed with H-NMR and C 13 NMR. The results are summarized below, in Tables 2-4 and in FIGS. 1 and 2 . Calcium, potassium and sodium content was estimated by atomic absorption using conventional methods and apparatus. The calcium content of a representative sample was found to be 9%. The potassium content by this method was 14% and the sodium content was 0.5%.
[0044] The C 13 NMR spectrum for the calcium-potassium hydroxycitric acid salt is shown in FIG. 1 , and summarized in Table 2. The respective carbon atoms are indicated on the chart. There are three quaternary carbons appearing at chemical shift: 40.3, 74.9, 78.1 and carbonyl carbons at the chemical shift: 173.9, 175.5, 176.05 confirming the structural carbons of hydroxycitric acid in the sample.
[0000]
TABLE 2
C 13 NMR
Chemical shift
Assignment
40.3
Methylene carbon (—CH 2 —)
74.94
Methine carbon (—CH—)
78.11
173.9, 175.53, 176.05
Carbons of acid carbonyl
[0045] The proton NMR spectrum for the HCA salt is shown in FIG. 2 , and summarized in Table 3. The acid protons and hydroxy protons are not visible due to D 2 O exchange.
[0000]
TABLE 3
PROTON NMR
Chemical shift (ppm)
Assignment
No.
2.5-3.5 (multiplet)
—CH 2 —
two protons
4.35 (singlet)
—CH—
single proton
4.75 (off scale large peak)
HOD D 2 O exchanged
structural water
Frequency: 300 MHZ
Nucleus: 1 H
Solvent: D 2 O (Since the material was a salt and insoluble in all deuterated solvents like acetone-D6, DMF-D6, chloroform-D, C it was decided to use water-D2.) By this method all exchangeable protons will not be seen in the NMR spectra.
Animal Toxicity Study
[0046] A representative lot of powder obtained as described above is a pure, stable calcium potassium salt of hydroxycitric acid having a proximate analysis of 70 to 75% hydroxycitric acid, 7.5% to 9.5% calcium, 12 to 15% potassium and 3 to 5% structural moisture. The sodium content is less than 0.5%, and HCA lactone content is less than 0.5%. An animal toxicity study was conducted on the product to establish its LD 50 . The LD 50 of a representative sample was found to be more than 5 gm/kg in female Wistar rats. The protocol for the study is summarized in Table 5 and as follows:
[0000] TABLE 5 REPORT ON LD 50 OF TEST COMPOUND Sr. No. Name Description 1 Test Compound White Fine Powder 2 Solubility Soluble In Water 3 Method of Testing Acute Oral Toxicity (OECD Test Guideline 425) Statistical Program
Doses were selected in accordance with the Acute Oral Toxicity (OECD Test Guideline 425) Statistical Program as follows: 175, 550, 1750, 5000 mg/kg of body weight in adult female Wistar rats.
[0000]
TABLE 6
Protocol for Animal Toxicity Study
Test/Substance:
Test Compound
Test type:
Main Test
Limit dose (mg/kg):
5000
Assumed LD50 (mg/kg):
Default
Assumed sigma (mg/kg):
0.5
Recommended dose
1.75, 5.5, 17.5, 55, 5000,
progression:
175, 550, 1750
[0000]
TABLE 7
Animal Toxicity Data
Test
Short-term
Seq.
Animal ID
Dose (mg/kg)
Result
Long-term Result
1
H
175
◯
◯
2
B
550
◯
◯
3
T
2000
◯
◯
4
HB
5000
◯
◯
5
HT
5000
◯
◯
6
BT
5000
◯
◯
(X = Died, ◯ = Survived)
Dose Recommendation: The main test is complete.
Stopping criteria met: 3 at Limit Dose.
[0000]
TABLE 8
Summary of Long-Term Animal Toxicity Test Results
Dose (mg/kg)
Survived
Died
Total
175
1
0
1
550
1
0
1
2000
1
0
1
5000
3
0
3
All Doses
6
0
6
Conclusion: LD 50 of a sample of the Test Compound was found to be greater than 5000 mg/kg.
Dietary Aids for Weight Reduction Programs
[0047] The above-described calcium and potassium hydroxycitric acid salt compositions are useful in any of a variety of forms, including conventional pharmaceutical preparations and dietary supplements. For instance, they can be mixed with conventional organic or inorganic inert pharmaceutical carriers or dietary supplements suitable for oral or parenteral administration, such as, for example, water, gelatin, lactose, starch, magnesium stearate, talc, vegetable oil, gums or the like. They can be administered in conventional forms, e.g., solid forms, for example powders, tablets, capsules, suppositories or the like; or in liquid forms, for example, suspensions or emulsions. Optionally, these compositions can be subject to conventional pharmaceutical or dietary supplements expedients, such as sterilization, and can contain conventional pharmaceutical or dietary supplements excipients, such as preservatives, stabilizing agents, emulsifying agents, salts for the adjustment of osmotic pressure or buffers, and the like. The compositions can also be advantageously combined with other therapeutically active materials.
[0048] In addition, the above-described compositions can be formulated as a part of any type of processed food product. For example, in the form of a nutrition bar, baked good, beverage, drinking water, ice cream, candy or other item of food, using conventional techniques. Because the calcium-potassium HCA salt composition can be dissolved in water to provide a colorless, essentially tasteless, clear or transparent, precipitate-free solution, one of the more preferred forms of administration is in drinking water.
[0049] Whether administered as a tablet, a food, a drink, or other form, a suitable dosage unit for a human is generally about 15 mg to about 3 g of hydroxycitric acid, administered up to three times per day. For example, a suitable enteral dosage regimen in a human may range from about 1 mg per kilogram of body weight to about 50 mg per kilogram of body weight per day. For a particular subject, however, the specific dosage regimen can be adjusted according to individual need and the professional judgment of the person administering or supervising the administration of product. Likewise, the HCA salt composition may also be administered to pets, agricultural animals, and other mammals using the same dosage guidelines, to obtain weight reduction.
[0050] For aiding a typical weight loss program in a human, an orally administered food product, such as drinking water, a flavored beverage or a power bar containing an above-described calcium-potassium hydroxycitric acid composition will preferably make up above 0.001 to 25%, preferably 0.05 to 5% by weight of the total weight of the food product.
[0051] While the preferred embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. The embodiments described herein are exemplary only, and are not intended to be limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims. The disclosures of all patents, patent applications and publications cited herein are hereby specifically incorporated herein by reference, to the extent that they provide materials, methods or other details supplementary to those set forth herein. | Disclosed is a hydroxycitric acid salt composition comprising a mixture of calcium and potassium salts of hydroxycitric acid, preferably in a defined proportion. The HCA salts are prepared by a process that includes treating an aqueous extract of Garcinia cambogia or Garcinia indica fruit with a liquid quaternizing agent such as a trialkylamine in which the alkyl groups are octyl, caprylyl, isooctyl, lauryl or decyl. The process yields a very pure, stabilized mixed salt composition that is free of potentially toxic chemical residues, and is substantially tasteless for optimal use in a variety of foods, beverages and dietary supplements. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to long span conveyor systems and more particularly to an improved track section and novel hanger support assembly utilized therein.
Conventional power and free conveyor systems utilize a track structure formed by end-to-end track sections each comprising an I beam member mounted above and co-extensive with a pair of opposed channel iron members. The vertically aligned I beam and channel members are connected and spaced apart by yoke plates which are spaced along the length of the track section. The I beam member, referred to as the power rail, supports the drive trolleys and drive chain with the opposed channel members forming a track which supports the free trolleys and load-bearing carrier assemblies extending therebetween.
In a typical installation these track sections are suspended from the overlying main beams of the superstructure of the building in which the conveyor is installed. In order to comply with the specifications and standards for deflection and stress, it is usually necessary to add intermediate beams on closer centers than the main beams in order to provide intermediate support points to shorten the span. Although the specifications can be met in this manner, the addition of such intermediate support structure increases system costs and adds to the load to be borne by the original building superstructure, which often must then be reinforced in order to support the added weight.
A previous method addressing the elimination of additional superstructure has been described in U.S. Pat. No. 3,217,658. Therein is described a conveyor track section utilizing a longitudinally tapered rail cap for reinforcing the I beam power rail. Yoke plates extend through slots in the rail cap with the depending legs thereof supporting the channel-shaped members of the free trolley track therebelow. This arrangement proposes to increase the overall strength and rigidity of the track section. Although assumably effective in its function, the disclosed structural design of the rail cap requires each track section to be individually constructed so as to be suspended at its terminal ends from the overhead beams with the tapered rail cap extending therebetween. Thus the length of the section must correspond to the length of span between hanger points as defined by the location of the overhead building support beams. In turn the construction of variously-dimensioned track sections is necessary and results in increased engineering, fabrication and installation costs.
Also, it may be necessary to extend straight sections of the track beyond such hanger support points for connection to displaced vertical and/or horizontal turns of the conveyor system. Thus additional straight track sections of the above design are required which again increases system costs.
Finally, the prior methods of fastening each track section to the superior superstructure utilized an angle iron clip welded to the top of the I beam power rail and bolted to an angle iron hanger attached to the overlying superstructure. This prior method was a costly, labor-intensive one and dependent on the skill of the welder. Moreover, reliability was a problem as there was no efficient way to pretest the strength of the weld between the angle iron clip and I beam.
In response thereto, I have invented a novel track section that uses a uniform, serrated, T-shaped element as a continuous, reinforcing rail cap for the underlying power rail and free trolley track suspended therefrom. My continuous rail cap presents an upper flange member, superior to the power rail I beam, which cooperates with a novel hanger assembly so that the rail cap may be hung from the overlying superstructure at user-selectable points therealong. Moreover, the hanger assembly presents a clamp which slidably receives the upper flange member of the rail cap until tightened and thus is not welded thereto and may be easily positioned during installation of the track. Accordingly, the maximum load capacity of the hanger assembly may be readily predetermined in order to avoid the uncertainties associated with weld attachment as above-described. Therefore, a plurality of track sections of standard length utilizing my new design may be fabricated off site with the assurance that they can be used in normal subsequent installations. In turn, design, manufacture and installation costs are reduced and the overall cost effectiveness of the power and free conveyor system is thus enhanced.
It is, therefore, a general object of this invention to provide a reinforced track section for a power and free conveyor system.
Another object of this invention is to provide a track section, as aforesaid, which uses a uniform, continuously extending rail cap for reinforcement of the underlying I beam power rail and trolley track depending therefrom.
Still another object of this invention is to provide a track section, as aforesaid, in combination with a novel track hanger engaging the rail cap to suspend the track section from the overlying building superstructure at user-selectable points therealong.
Another important object of this invention is to provide a track section utilizing a hanger assembly, as aforesaid, in which the hanger slidably receives the rail cap therein until the installation is complete.
Another object of this invention is to provide a track section with hanger assembly, as aforesaid, in which the maximum load capacity of the hanger assembly is determinable before suspension of a track section therefrom.
A more particular object of this invention is to provide a rail cap, as aforesaid, which offers a uniform, uninterrupted reinforcement to the underlying track section connected thereto.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a conventional I beam.
FIG. 2 is a fragmentary elevation view of a conventional I beam having a line of serration scored on the web portion thereof.
FIG. 3 is a fragmentary elevation view of the I beam of FIG. 2 subsequent to separation along the line of serration.
FIG. 4 is an elevation view, foreshortened for purposes of illustration, and showing first and second suspended and connected track sections of a power and free conveyor system as reinforced by the rail caps of FIG. 3.
FIG. 5 is an enlarged, sectional elevation view, taken along line 5--5 in FIG. 4, showing the hanger assembly.
FIG. 6 is an enlarged, sectional elevation view, taken along line 6--6 in FIG. 4, showing a yoke plate of a track section of the power and free conveyor system.
FIG. 7 is a perspective view of a portion of the track section with the power and free trolleys and drive chain removed therefrom.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to the drawings, each track section 10 generally comprises an I beam power rail 12 having upper 14 and lower 16 flanges with a web member 18 extending therebetween. The power rail 12 provides a track for the power trolleys 20 and more particularly for the roller members 22 therein. The power conveyor chain 24 is suspended below the power rail 12 by means of the power trolleys 20 as shown in FIG. 4. (Note that FIG. 4 illustrates two track sections 10, 10' connected at points 100.)
Each track section further comprises a free trolley track 26 formed by opposed channel members 28 and 30 which define a compartment for rolling movement of the wheels 36 of the underlying free trolleys 32. Drive dogs 35 extend upwardly from these free trolleys 32 and engage the power dogs 34 of drive chain 24 for rolling movement of the free trolleys 32 with the power trolleys 20.
The free trolley track 26 is suspended below the power rail 12 by means of longitudinally spaced yoke plates 40. Each yoke plate 40 comprises a top portion 42, transversely attached to the power rail, and a pair of depending legs 44 and 46 attached at their lower ends to the exterior faces of the respective channels 28 and 30.
Mounted above the power rail 12 is a reinforcing rail cap generally designated as 50. The rail cap comprises a top flange 52 having a serrated web member 54 depending therefrom. This serrated web member 54 presents a plurality of spaced-apart, identical stems 58 of generally triangular configuration attached at their lower horizontal edges 56 to the upper flange 14 of the interiorly disposed power rail 12. The longitudinal spatial displacement of stems 58 along the rail cap 50, provided by the serrated web, presents interstices which allow for extension of the top portions 42 of the yoke plates 40 therethrough, as shown in FIG. 7. Accordingly, the top portion 42 of each yoke plate 40 is centered between two adjacent stems 58 and interposed between the upper flange 52 of rail cap 50 and the power rail 12 and welded thereto.
The continuous rail cap 50 provides an uninterrupted reinforcement over the length of the track section 10 and, being the uppermost component of the track, may be attached to the building superstructure. It should be noted that the continuous upper flange 52 of rail cap 50 offers a continuous means of attachment of the rail cap 50 to this overlying superstructure (not shown). Such attachment is effectively provided by means of a hanger assembly 62 particularly designed to slidably engage this upper flange 52 until secured in place. The hanger assembly 62 comprises opposed shanks 64, 65 having depending, spaced-apart, hook-shaped members 66, 67 presenting an eye 68 receiving the flange 52 as best illustrated in FIG. 5.
The hanger assembly 62 is attached to an angle iron hanger 69 by two vertically spaced bolts 70 and associated nuts and lock washers as shown in FIG. 5. As may be seen, the bolts pass through openings (not shown) in the shanks 64, 65 and one of the flanges of the angle iron hanger 69 to secure the shanks on opposite sides of such flange. The angle iron hanger 69 depends from the overlying superstructure of the building (not shown) in the conventional manner.
Before the bolts 70 are tightened, the flange 52 of rail cap 50 fits loosely in the eye 68 so that the hanger assembly 62 and the rail cap 50 can be shifted relative to each other for adjustment during installation of the track section. In FIG. 4 two hanger assemblies 62 are shown suspending track section 10 at points near the right end thereof and at a second point leftwardly along the span where an overhead support (not shown) is available. Once the track section is positioned as desired and the hanger assemblies 62 are located at the points selected for the particular installation, the bolts 70 are tightened to clamp the hook-shaped members 66, 67 against the opposed edges of the flange 52 of the rail cap 50. This clamping action upon tightening the bolts 70 (shown tightened in FIG. 5) thus provides a rigid connection between the rail cap 50 and each angle iron hanger 69 without the need for welded joints.
The rail cap 50 is constructed, as shown in FIGS. 2 and 3, so that the first and second serrated sections are derived from a single I beam 71, as shown in FIG. 1. As shown in FIG. 2, a serrated burn line 72 is scored along the web 54 of the I-beam 71 for subsequent separation therealong, as shown in FIG. 3, to present first and second rail caps 50, 50'. Accordingly, the rail cap 50 is easily fabricated from conventional I beam stock.
Thus a plurality of long span track sections 10, 10' of uniform length can be shop-fabricated without the location of the overhead supports being a primary design consideration. Also, the use of the hanger assemblies 62 eliminates the previous welding of clips to the I beam 12 and the labor costs and unreliability associated therewith. Finally, the continuous extension of the uniform rail cap 50 along the power rail 12, attached thereto by the congruent stems 58, provides uninterrupted, uniform reinforcement of the power rail. Therefore, a uniform rigidity is provided to the track section 10 which supports greater live loads while still meeting the industry standard allowances for deflection and stress values of the components of the power and free system.
It is to be understood that while a certain form of this invention has been illustrated and described, it is not limited thereto, except in so far as such limitations are included in the following claims. | A reinforced track section for a power and free conveyor system utilizes a conventional power rail with a free trolley track suspended therefrom. A uniform rail cap is superiorly attached to the power rail so as to provide a continuous, uninterrupted reinforcement thereto. The rail cap includes a continuous mounting flange in cooperation with hanger clamps which suspend the rail cap and underlying power and free tracks from overhead support structure at user-selectable points along the flange. | 4 |
RELATED APPLICATIONS
The present application is a continuation-in-part of U.S. patent application Ser. No. 10/173,990, filed Jun. 18, 2002, which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to a fuel recovery system for recovering leaks that occur in fuel supply piping in a retail fueling environment.
BACKGROUND OF THE INVENTION
Managing fuel leaks in fueling environments has become more and more important in recent years as both state and federal agencies impose strict regulations requiring fueling systems to be monitored for leaks. Initially, the regulations required double-walled tanks for storing fuel accompanied by leak detection for the tanks. Subsequently, the regulatory agencies have become concerned with the piping between the underground storage tank and the fuel dispensers and are requiring double-walled piping throughout the fueling environment as well.
Typically, the double-walled piping that extends between fuel handling elements within the fueling environment terminates at each end with a sump that is open to the atmosphere. In the event of a leak, the outer pipe fills and spills into the sump. The sump likewise catches other debris, such as water and contaminants, that contaminate the fuel caught by the sump, thereby making this contaminated fuel unusable. Thus, the sump is isolated from the underground storage tank, and fuel captured by the sump is effectively lost.
Coupled with the regulatory changes in the requirements for the fluid containment vessels are requirements for leak monitoring such that the chances of fuel escaping to the environment are minimized. Typical leak detection devices are positioned in the sumps. These leak detection devices may be probes or the like and may be connected to a control system for the fueling environment such that the fuel dispensing is shut down when a leak is detected.
Until now, fueling environments have been equipped with elements from a myriad of suppliers. Fuel dispensers might be supplied by one company, the underground storage tanks by a second company, the fuel supply piping by a third company, and the tank monitoring equipment by yet a fourth company. This makes the job of the designer and installer of the fueling environment harder as compatibility issues and the like come into play. Further, it is difficult for one company to require a specific leak detection program with its products. Interoperability of components in a fueling environment may provide economic synergies to the company able to effectuate such, and provide better, more integrated leak detection opportunities.
Any fuel piping system that is installed for use in a fueling environment should advantageously reduce the risk of environmental contamination when a leak occurs, and attempt to recapture fuel that leaks for reuse and reduce excavation costs, further reducing the likelihood of environmental contamination. Still further, such a system should include redundancy features and help reduce the costs of clean up.
SUMMARY OF THE INVENTION
While the parent application of the present invention capitalizes on the synergies created between the tank monitoring equipment, the submersible turbine pump (STP), and the fuel dispenser in a fueling environment, the present application supplements this disclosure by offering an alternative leaked fuel collection point. However, for continuity, the original, underlying invention is discussed first. A fluid connection that carries a fuel supply for eventual delivery to a vehicle is made between the underground storage tank and the fuel dispensers via double-walled piping. Rather than use the conventional sumps and low point drains, the present invention drains any fuel that has leaked from the main conduit of the double-walled piping back to the underground storage tank. This addresses the need to recapture the fuel for reuse and to reduce fuel that is stored in sumps which must later be retrieved and excavated by costly service personnel.
The fluid in the outer conduit may drain to the underground storage tank by gravity coupled with the appropriately sloping piping arrangements, or a vacuum may be applied to the outer conduit from the vacuum in the underground storage tank. The vacuum will drain the outer conduit. Further, the return path may be fluidly isolated from the sumps, thus protecting the fuel from contamination.
In an exemplary embodiment, the fuel dispensers are connected to one another via a daisy chain fuel piping arrangement rather than by a known main and branch conduit arrangement. Fuel supplied to a first fuel dispenser by the STP and conduit is carried forward to other fuel dispensers coupled to the first fuel dispenser via the daisy chain fuel piping arrangement. The daisy chain is achieved by a T-intersection contained within a manifold in each fuel dispenser. Fuel leaking in the double-walled piping is returned through the piping network through each downstream fuel dispenser before being returned to the underground storage tank.
The daisy chain arrangement allows for leak detection probes to be placed within each fuel dispenser so that leaks between the fuel dispensers may be detected. The multiplicity of probes causes leak detection redundancy and helps pinpoint where the leak is occurring. Further, the multiple probes help detect fuel leaks in the outer conduit of the double-walled piping. This is accomplished by verifying that fuel dispensers downstream of a detected leak also detect a leak. If they do not, a sensor has failed or the outer conduit has failed. A failure in the outer piping is cause for serious concern as fuel may be escaping to the environment and a corresponding alarm may be generated.
Another possibility with the present invention is to isolate sumps, if still present within the fuel dispenser, from this return path of captured leaking fuel such that contaminants are precluded from entering the leaked fuel before being returned to the underground storage tank. In this manner, fuel may potentially be reused since it is not contaminated by other contaminants, such as water, and reclamation efforts are easier. Since the fuel is returned to the underground storage tank, there is less danger that a sump overflows and allows the fuel to escape into the environment.
As another embodiment, and the focus of the present invention, the fuel dispensers may remain in the previously described daisy chain configuration. However, instead of returning the leaked fuel to the underground storage tank, the outer wall of the double-walled piping may terminate at the STP. The STP may capture the returned leaking fuel to a sump within the STP or, in an alternate permutation, to an external sump. In either event, the outer wall terminates prior to the underground storage tank. The leak detection processes of the parent invention are likewise useful in this embodiment. Further, a leak detection sensor may be positioned in the sump so that the sump may be serviced as needed.
Those skilled in the art will appreciate the scope of the present invention and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the invention, and together with the description serve to explain the principles of the invention.
FIG. 1 illustrates a conventional communication system within a fueling environment in the prior art;
FIG. 2 illustrates a conventional fueling path layout in a fueling environment in the prior art;
FIG. 3 illustrates, according to an exemplary embodiment of the present invention, a daisy chain configuration for a fueling path in a fueling environment;
FIG. 4 illustrates, according to an exemplary embodiment of the present invention, a fuel dispenser;
FIG. 5 illustrates a first embodiment of a fuel return to underground storage tank arrangement;
FIG. 6 illustrates a second embodiment of a fuel return to underground storage tank arrangement;
FIG. 7 illustrates a flow chart showing the leak detection functionality of the present invention;
FIG. 8 illustrates an alternate embodiment wherein the fuel return terminates in the head of the submersible turbine pump; and
FIG. 9 illustrates an alternate embodiment wherein the fuel return terminates in a sump after passing through the head of the submersible turbine pump.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the invention and illustrate the best mode of practicing the invention. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.
Fueling environments come in many different designs. Before describing the particular aspects of the parent application's invention (which begins at the description of FIG. 3 ), or the present invention (which begins at the description of FIG. 8 ), a brief description of a fueling environment follows. A conventional exemplary fueling environment 10 is illustrated in FIGS. 1 and 2 . Such a fueling environment 10 may comprise a central building 12 , a car wash 14 , and a plurality of fueling islands 16 .
The central building 12 need not be centrally located within the fueling environment 10 , but rather is the focus of the fueling environment 10 , and may house a convenience store 18 and/or a quick serve restaurant 20 therein. Both the convenience store 18 and the quick serve restaurant 20 may include a point of sale 22 , 24 , respectively. The central building 12 may further house a site controller (SC) 26 , which in an exemplary embodiment may be the G-SITE® sold by Gilbarco Inc. of Greensboro, N.C. The site controller 26 may control the authorization of fueling transactions and other conventional activities as is well understood. The site controller 26 may be incorporated into a point of sale, such as point of sale 22 , if needed or desired. Further, the site controller 26 may have an off site communication link 28 allowing communication with a remote location for credit/debit card authorization, content provision, reporting purposes or the like, as needed or desired. The off site communication link 28 may be routed through the Public Switched Telephone Network (PSTN), the Internet, both, or the like, as needed or desired.
The car wash 14 may have a point of sale 30 associated therewith that communicates with the site controller 26 for inventory and/or sales purposes. The car wash 14 alternatively may be a stand alone unit. Note that the car wash 14 , the convenience store 18 , and the quick serve restaurant 20 are all optional and need not be present in a given fueling environment.
The fueling islands 16 may have one or more fuel dispensers 32 positioned thereon. The fuel dispensers 32 may be, for example, the ECLIPSE®) or ENCORE® sold by Gilbarco Inc. of Greensboro, N.C. The fuel dispensers 32 are in electronic communication with the site controller 26 through a LAN or the like.
The fueling environment 10 also has one or more underground storage tanks 34 adapted to hold fuel therein. As such, the underground storage tank 34 may be a double-walled tank. Further, each underground storage tank 34 may include a liquid level sensor or other sensor 35 positioned therein. The sensors 35 may report to a tank monitor (TM) 36 associated therewith. The tank monitor 36 may communicate with the fuel dispensers 32 (either through the site controller 26 or directly, as needed or desired) to determine amounts of fuel dispensed, and compare fuel dispensed to current levels of fuel within the underground storage tanks 34 to determine if the underground storage tanks 34 are leaking. In a typical installation, the tank monitor 36 is also positioned in the central building 12 , and may be proximate the site controller 26 .
The tank monitor 36 may communicate with the site controller 26 and further may have an off site communication link 38 for leak detection reporting, inventory reporting, or the like. Much like the off site communication link 28 , off-site communication link 38 may be through the PSTN, the Internet, both, or the like. If the off site communication link 28 is present, the off site communication link 38 need not be present and vice versa, although both links may be present if needed or desired. As used herein, the tank monitor 36 and the site controller 26 are site communicators to the extent that they allow off site communication and report site data to a remote location.
For further information on how elements of a fueling environment 10 may interact, reference is made to U.S. Pat. No. 5,956,259, which is hereby incorporated by reference in its entirety. Information about fuel dispensers may be found in commonly owned U.S. Pat. Nos. 5,734,851 and 6,052,629, which are hereby incorporated by reference in their entirety. Information about car washes may be found in commonly owned U.S. patent application Ser. No. 60/380,111, filed May 6, 2002, entitled IMPROVED SERVICE STATION CAR WASH, which is hereby incorporated by reference in its entirety. An exemplary tank monitor 36 is the TLS-350R manufactured and sold by Veeder-Root. For more information about tank monitors 36 and their operation, reference is made to U.S. Pat. Nos. 5,423,457; 5,400,253; 5,319,545; and 4,977,528, which are hereby incorporated by reference in their entireties.
In addition to the various conventional communication links between the elements of the fueling environment 10 , there are conventional fluid connections to distribute fuel about the fueling environment as illustrated in FIG. 2 . Underground storage tanks 34 may each be associated with a vent 40 that allows over-pressurized tanks to relieve pressure thereby. A pressure valve (not shown) is placed on the outlet side of each vent 40 to open to atmosphere when the underground storage tank 34 reaches a predetermined pressure threshold. Additionally, under-pressurized tanks may draw air in through the vents 40 . In an exemplary embodiment, two underground storage tanks 34 exist—one a low octane tank ( 87 ) and one a high octane tank ( 93 ). Blending may be performed within the fuel dispensers 32 as is well understood to achieve an intermediate grade of fuel. Alternatively, additional underground storage tanks 34 may be provided for diesel and/or an intermediate grade of fuel (not shown).
Pipes 42 connect the underground storage tanks 34 to the fuel dispensers 32 . Pipes 42 may be arranged in a main conduit 44 and branch conduit 46 configuration, where the main conduit 44 carries the fuel to the branch conduits 46 , and the branch conduits 46 connect to the fuel dispensers 32 . Typically, pipes 42 are double-walled pipes comprising an inner conduit and an outer conduit. Fuel flows in the inner conduit to the fuel dispensers, and the outer conduit insulates the environment from leaks in the inner conduit. For a better explanation of such pipes and concerns about how they are connected, reference is made to Chapter B13 of PIPING HANDBOOK, 7 th edition, copyright 2000, published by McGraw-Hill, which is hereby incorporated by reference.
In a typical service station installation, leak detection may be performed by a variety of techniques, including probes and leak detection cables. More information about such devices can be found in the previously incorporated PIPING HANDBOOK. Conventional installations do not return to the underground storage tank 34 fuel that leaks from the inner conduit to the outer conduit, but rather allow the fuel to be captured in low point sumps, trenches, or the like, where the fuel mixes with contaminants such as dirt, water and the like, thereby ruining the fuel for future use without processing.
While not shown, vapor recovery systems may also be integrated into the fueling environment 10 with vapor recovered from fueling operations being returned to the underground storage tanks 34 via separate vapor recovery lines (not shown). For more information on vapor recovery systems, the interested reader is directed to U.S. Pat. Nos. 5,040,577; 6,170,539; and Re. U.S. Pat. No 35,238; and U.S. patent application Ser. No. 09/783,178 filed Feb. 14, 2001, all of which are hereby incorporated by reference in their entireties.
Now turning to the invention of the parent application, the main and branch supply conduit arrangement of FIG. 2 is replaced by a daisy chain fuel supply arrangement as illustrated in FIG. 3 . The underground storage tank 34 provides a fuel delivery path to a first fuel dispenser 32 1 via a double-walled pipe 48 . The first fuel dispenser 32 1 is configured to allow the fuel delivery path to continue onto a second fuel dispenser 32 2 via a daisy chaining double-walled pipe 50 . The process repeats until an nth fuel dispenser 32 n is reached. Each fuel dispenser 32 has a manifold 52 with an inlet aperture and an outlet aperture as will be better explained below. In the nth fuel dispenser 32 n , the outlet aperture is terminated conventionally as described in the previously incorporated PIPING HANDBOOK.
As better illustrated in FIG. 4 , each fuel dispenser 32 comprises a manifold 52 with a T-intersection 54 housed therein. The T-intersection 54 allows the fuel line conduit 56 to be stubbed out of the daisy chaining double-walled pipe 50 and particularly to extend through the outer wall 58 of the daisy chaining double-walled pipe 50 . This T-intersection 54 may be a conventional T-intersection such as is found in the previously incorporated PIPING HANDBOOK. The manifold 52 comprises the aforementioned inlet aperture 60 and outlet aperture 62 . While shown on the sides of the manifold 52 's housing, these apertures could equivalently be on the bottom side of the manifold 52 , if desired. Please note that the present invention is not limited to a manifold 52 with a T-joint, and that any other suitable configuration may be used that allows fuel to be supplied to a fuel dispenser 32 and allows the fuel to continue on as well to the next fuel dispenser 32 until the last fuel dispenser 32 is reached.
A leak detection probe 64 may also be positioned within the manifold 52 . This leak detection probe 64 may be any appropriate liquid detection sensor as needed or desired. The fuel dispenser 32 has conventional fuel handling components 66 associated therewith, such as a fuel pump 68 , a vapor recovery system 70 , a fueling hose 72 , a blender 74 , a flow meter 76 , and a fueling nozzle 78 . Other fuel handling components 66 may also be present as is well understood in the art.
With this arrangement, the fuel may flow into the fuel dispenser 32 in the fuel line conduit 56 , passing through the inlet aperture 60 of the manifold 52 . A check valve 80 may be used if needed or desired as is well understood to prevent fuel from flowing backwards. The fuel handling components 66 draw fuel through the check valve 80 and into the handling area of the fuel dispenser 32 . Fuel that is not needed for that fuel dispenser 32 is passed through the manifold 52 upstream to the other fuel dispensers 32 within the daisy chain. A sump (not shown) may still be associated with the fuel dispenser 32 , but it is fluidly isolated from the daisy chaining double-walled pipe 50 .
A first embodiment of the connection to the daisy chaining double-walled pipe 50 to the underground storage tank 34 is illustrated in FIG. 5 . The daisy chaining double-walled pipe 50 connects to a distribution head 82 , which in turn connects to the double-walled pipe 48 . Portions of the submersible turbine pump, such as the pump and the motor, may be contained within the distribution head 82 . The boom 84 of the submersible turbine pump is positioned within the underground storage tank 34 , preferably below the level of fuel 86 within the underground storage tank 34 . For a more complete exploration of the submersible turbine pump, reference is made to U.S. Pat. No. 6,223,765 assigned to Marley Pump Company, which is incorporated by reference in its entirety, and the product exemplifying the teachings of the patent explained in Quantum Submersible Pump Manual: Installation and Operation , also produced by the Marley Pump Company, also incorporated by reference in its entirety. In this embodiment, fuel captured by the outer wall 58 is returned to the distribution head 82 such as through a vacuum or by gravity feeds. A valve (not shown) may allow the fuel to pass into the distribution head 82 and thereby be connected to the double-walled pipe 48 for return to the underground storage tank 34 . The structure of the distribution head in the '765 patent is well suited for this purpose having multiple paths by which fuel may be returned to the outer wall of the double-walled pipe that connects the distribution head 82 to the submersible turbine pump 84 .
A second embodiment of the connection of the daisy chaining double-walled pipe 50 to the underground storage tank 34 is illustrated in FIG. 6 . The distribution head 82 is substantially identical to the previously incorporated U.S. Pat. No. 6,223,765. The daisy chaining double-walled pipe 50 , however, comprises a fluid connection 88 to the double-walled pipe 48 . This allows the fuel in the outer wall 58 to drain directly to the underground storage tank 34 , instead of having to provide a return path through the distribution head 82 . Further, the continuous fluid connection from the underground storage tank 34 to the outer wall 58 causes any vacuum present in the underground storage tank 34 to also be existent in the outer wall 58 of the daisy chaining double-walled pipe 50 . This vacuum may help drain the fuel back to the underground storage tank 34 . In an exemplary embodiment, the fluid connection 88 may also be double-walled so as to comply with any appropriate regulations.
FIG. 7 illustrates the methodology of the parent invention. During new construction of the fueling environment 10 , or perhaps when adding the present invention to an existing fueling environment 10 , the daisy chained piping system according to the present invention is installed (block 100 ). The pipe connection between the first fuel dispenser 32 1 and the underground storage tank 34 may, in an exemplary embodiment, be sloped such that gravity assists the drainage from the fuel dispenser 32 to the underground storage tank 34 . The leak detection system, and particularly the leak detection probes 64 , are installed in the manifolds 52 of the fuel dispensers 32 (block 102 ). Note that the leak detection probes 64 may be installed during construction of the fuel dispensers 32 or retrofit as needed. In any event, the leak detection probes 64 may communicate with the site communicators such as the site controller 26 or the tank monitor 36 as needed or desired. This communication may be for alarm purposes, calibration purposes, testing purposes or the like as needed or desired. Additionally, this communication may pass through the site communicator to a remote location if needed. Further, note that additional leak detectors (not shown) may be installed for redundancies and/or positioned in the sumps of the fuel dispensers 32 . Still further, leak detection programs may be existent to determine if the underground storage tank 34 is leaking. These additional leak detection devices may likewise communicate with the site communicator as needed or desired.
The fueling environment 10 operates as is conventional, with fuel being dispensed to vehicles, vapor recovered, consumers interacting with the points of sale, and the operator generating revenue (block 104 ). At some point, a leak occurs between two fuel dispensers 32 x and 32 x+1 . Alternatively, the leak may occur at a fuel dispenser 32 x+1 (block 106 ). The leaking fuel flows towards the underground storage tank 34 (block 108 ), as a function of the vacuum existent in the outer wall 58 , via gravity or the like. The leak is detected at the first downstream leak detection probe 64 (block 110 ). Thus, in the two examples, the leak would be detected by the leak detection probe 64 positioned within the fuel dispenser 32 x . This helps in pinpointing the leak. An alarm may be generated (block 112 ). This alarm may be reported to the site controller 26 , the tank monitor 36 or other location as needed or desired.
A second leak detection probe 64 , positioned downstream of the first leak detection probe 64 in the fuel dispenser 32 x−1 , will then detect the leaking fuel as it flows past the second leak detection probe 64 (block 114 ). This continues, with the leak detection probe 64 in each fuel dispenser 32 downstream of the leak detecting the leak until fuel dispenser 32 1 detects the leak. The fuel is then returned to the underground storage tank 34 (block 116 ).
If all downstream leak detection probes 64 detect the leak at query block 118 , that is indicative that the system works (block 120 ). If a downstream leak detection probe 64 fails to detect the leak during the query of block 118 , then there is potentially a failure in the outer wall 58 and an alarm may be generated (block 122 ). Further, if the leak detection probes 64 associated with fuel dispensers 32 x+1 and 32 x−1 both detect the leak, but the leak detection probe 64 associated with the fuel dispenser 32 x does not detect a leak, that is indicative of a sensor failure and a second type of alarm may be generated.
Additionally, once a leak is detected and the alarm is generated, the fueling environment 10 may shut down so that clean up and repair can begin. However, if the double-walled piping system works the way it should, the only repair will be to the leaking section of inner pipe within the daisy chaining double-walled pipe 50 or the leaking fuel dispenser 32 . Any fuel caught by the outer wall 58 is returned for reuse, thus saving on clean up.
As an alternative to draining the fuel back to the underground storage tank 34 , the present invention also provides for the situation where the fuel drains to a sump associated with the submersible turbine pump. This alternative has two embodiments, one in which the sump is positioned in the distribution head 82 of the submersible turbine pump (illustrated in FIG. 8 ) and one in which the sump is positioned outside the distribution head 82 of the submersible turbine pump (illustrated in FIG. 9 ). In both embodiments, there must be some mechanism to encourage proper draining. This may be a gravity feed through sloped pipes, a vacuum, a lower pressure, or the like. These and other techniques known to those of ordinary skill the art may be used to cause the fuel that has leaked into the outer annular space of the double-walled piping to flow back to the sump. Likewise, in both embodiments, the daisy chain piping arrangement and the leak detection sensor array previously described are readily adapted for use.
In the first embodiment, illustrated in FIG. 8 , the daisy chaining double-walled pipe 50 has an outer annular path 150 formed by outer wall 58 . A bypass tube 152 fluidly couples the outer annular path 150 to a sump chamber 154 where fuel captured by the double-walled piping may collect. A pressure sensor 156 may be positioned within the sump chamber 154 to detect any pressure changes within the outer portion of the daisy chaining double-walled piping 50 . This pressure change may be indicative of a leak as is described in U.S. patent application Ser. No. 10/238,822, entitled SECONDARY CONTAINMENT SYSTEM AND METHOD, filed Sep. 10, 2002, which is hereby incorporated by reference in its entirety.
In the second embodiment, illustrated in FIG. 9 , the daisy chaining double-walled pipe 50 terminates the outer annular path 150 prior to reaching the interior of the distribution head 82 and drains via a bypass tube 158 to an external sump chamber 160 . External sump chamber 160 may have a pressure sensor 162 positioned therein similar to pressure sensor 156 .
Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present invention. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow. | A fueling environment distributes fuel from a fuel supply to fuel dispensers in a daisy chain arrangement with a double-walled piping system. Fuel leaks that occur within the double-walled piping system are returned to the underground storage tank or a sump proximate the submersible turbine pump by the outer wall of the double-walled piping. This preserves the fuel for later use and helps reduce the risk of environmental contamination. Leak detectors may also be positioned in to fuel dispensers detect leaks and provide alarms for the operator, and help pinpoint leak detection that has occurred in the piping system proximate to a particular fuel dispenser or in between two consecutive fuel dispensers. | 8 |
FIELD OF THE INVENTION
This invention relates to apparatus useful in investigating corrosion phenomenon that effect industrial equipment and, more particularly, to apparatus that is utilized in determining the electrochemical behavior of metals and the performance of corrosion inhibitors under controlled conditions.
BACKGROUND OF THE INVENTION
A wide variety of apparatus and methods have been developed by corrosion and design engineers for evaluating the effect of corrosion-producing fluids passing in contact with industrial equipment, such as heat exchangers, reactors, pipelines, and the like. Apparatus and methods for in situ testing of effects on pipelines are known, as are numerous laboratory techniques. Laboratory bench scale test devices known to the prior art include rotating disk and rotating cylinder specimens that are immersed in corrosive fluid media to determine the effects on, e.g., the types of metals that come into contact with comparable fluids under industrial conditions. The rotational movement of the specimens can be varied to simulate actual hydrodynamic conditions.
Many production processes and material transport systems in industrial plants involve heat transfer across a metal-fluid interface and mass transfer to or from that interface, including the buildup of scale deposits and loss of material due to corrosion. Materials selected for industrial applications must, therefore, be able to withstand or at least resist adverse effects that are initiated or accelerated by heat and mass transfer. In order to make the optimum choices, corrosion and design engineers need an understanding based on data relating to the effects of heat and mass transfer on material degradation from corrosion. Little investigative work on corrosion and corrosion prevention under heat and mass transfer conditions has apparently been reported in the literature.
It is therefore an object of the present invention to provide corrosion testing apparatus to examine the electrochemical behavior of metals and the performance of organic and inorganic inhibitors or passivators under conditions of controlled and quantified heat and mass transfer.
Another object of the invention is to provide a means for obtaining data to quantify the effect of various conditions and factors by simulating industrial conditions effecting the corrosion behavior of metals and the performance of chemical additive corrosion inhibitors.
A further object of the invention is to provide an apparatus that permits the bench scale investigation of industrial corrosion factors with minimum costs and that permits the testing and evaluation of inhibitors without risk of direct or indirect damage to the industrial facilities.
SUMMARY OF THE INVENTION
The above objects and other advantages are achieved by providing a single rotating electrode apparatus that is configured to receive either of a pair of rotating electrodes in heat conductive mounting relation in order to obtain quantified data under heat transfer conditions. The first of the pair of electrodes is a rotating disk electrode (RDE) and the second is a rotating cylinder electrode (RCE). Both the RDE and RCE are interchangeably mountable for rotation on the same rotational electrode supporting shaft in a test stand to provide economy of materials and measuring devices.
In a particularly preferred embodiment, the interchangeable rotating electrode supporting shaft is provided with an internally mounted heating element in the form of an electrical resistance heating device. The heat conductive member can be fabricated from brass in the form of a hollow cylinder proportioned to receive the heating device and its associated electrical leads. The heating device is positioned proximate to a metal heat conductive supporting member that efficiently conducts the heat generated to an external surface that is in contact with either a disk electrode or a cylindrical electrode specimen.
In a particularly preferred embodiment, a plurality of thermocouples or thermistors are embedded in the conductive member to provide temperature readings at positions closely adjacent to the point of attachment of the rotating electrode, as well as proximate and displaced from the heating device. The leads from the thermocouples also extend axially to the upper end of the rotating electrode shaft to a plug, socket or other terminal connection. The thermocouples are connected to a remote temperature display and recording device to provide the necessary data for controlling the power to the heating device to meet the desired temperature of the specimen electrode.
An electrically conductive lead is also attached to the metal conductive member on which the electrodes are mounted in heat and electrical conductive relation. This lead also extends to the plug or socket termination for subsequent connection to a power source.
In order to meet the electrical power requirements of the rotating electrode assembly during operation, the drive shaft that rotates the assembly is provided with a slip-ring assembly having a plurality of electrical conductors corresponding to the conductors required to provide current to the electrode support, heating device, and for each of the plurality of thermocouples mounted in the conductive member. Each of the leads from the slip-rings is terminated in a plug or socket for mating engagement for its counterpart in the end of the rotating electrode shaft. As an alternative, the plurality of leads from the slip-rings and the rotating electrode can be individually joined by appropriate insulated connectors.
A corresponding brush set is provided with appropriate leads to provide the necessary electrical power input to the slip-rings during rotation of the driveshaft. It will also be understood that the leads from the respective brushes are operably connected to one or more units for display and, optionally, recording of the temperature of each of the plurality of thermocouples; a separate power control and display unit is connected to the leads of the heating device. A separate power control unit and display is also provided for the working electrode. A single ground connection is utilized in a preferred embodiment in order to minimize the number of wires required.
In order to protect and isolate the heat conductive member from the corrosive fluid in which the unit is immersed, it is provided with a fluid-tight protective cover or housing. The protective cover material is also to be electrically non-conductive in order to isolate the rotating electrodes from stray currents.
The protective layer can be selected from such highly corrosion resistant and electrically insulative polymeric materials as polytetrafluoroethylene (PTFE). The protective housing is preferably provided in the form of a hollow cylindrical member with a wall thickness that provides a rigid construction. The cylindrical metal conductive member can then be positioned inside of the close-fitting hollow polymeric cylinder.
In order to provide a rigid point of attachment for the driveshaft coupling, the hollow protective housing is preferably extended well above the end of the internal conductive member to form a portion that also extends well beyond the top of the polarization cell when the rotating electrode is in an operational position. In order to provide additional rigidity to the upper end of the protective housing member at the point of attachment to the driveshaft coupling, a close-fitting cylindrical metal sleeve member having a flanged top is inserted into the hollow end of the protective member. This internal sleeve is designed to provide sufficient strength and rigidity to permit set screws or other attachment means to rigidly secure the driveshaft to the rotating electrode shaft. In order to maintain electrical isolation of the electrode, the reinforcing sleeve should not come into contact with the heat conductive member.
The lower portion of the metal conductive member is threaded externally in order to receive a cooperatively threaded rotating cylindrical electrode element that serves as the test specimen. In the preferred embodiment, the rotating cylinder electrode is threaded onto the conductive member to a position that substantially surrounds the internal heating device to minimize the distance heat must be transmitted through the conductive member to elevate the temperature of the rotating cylinder electrode specimen to the desired degree. In this regard, thermocouples or thermistors are positioned in the conductive member adjacent the mid-point of the rotating cylinder electrode when it is in position for operation.
In order to protect the lower portion of the cylindrical heat conducting member, an internally threaded polymeric protective cap in the form of a cup is positioned to provide a fluid-tight seal to the base of the rotating cylinder specimen when assembled to the conductive member. It will also be understood that the upper portion of the protective member forms a fluid-tight seal with the upper rim of the rotating cylinder when it is threaded onto the conductive member. Internally threaded caps of different depths can be provided to accommodate rotating cylinder specimens of different axial lengths. The direction of the respective threads is opposite that of the direction of rotation to insure that the electrode will not become loosened during operation.
In order to securely mount the rotating disk electrode, an internally threaded opening is provided in a smooth flat surface at the lower end of the supporting shaft to receive a cooperatively threaded attachment shaft projecting from the upper surface of the RDE. When the RDE is tightly threaded onto the end of the heat conductive member, the mating surfaces provide an efficient heat conducting interface boundary.
In a particularly preferred embodiment, a recessed or setback shoulder is provided at the upper end of the RDE in order to provide a mating surface for engagement with the projecting end of the hollow cylindrical protective member. This mating engagement is also intended to provide a fluid-tight seal that will prevent corrosive fluid incursions and contact with the metal conductive member.
The data obtained from the apparatus is applied utilizing known algorithms and methodologies known to those of ordinary skill in the art to calculate the surface temperature of a rotating cylinder electrode and/or disk that is transferring heat to the fluid in the test cell. Further calculations are undertaken to determine the effects of laminar flow conditions and turbulent flow conditions on the vulnerability of the test cylinders and disks to the corrosive fluid(s) in the test apparatus. Similarly, the data obtained is used to determine the effects of corrosion inhibitors and metal passivation additives under various temperature and simulated flow conditions.
The apparatus and method of the invention provide for the heating of either the RDE or the RCE, or both simultaneously, to a temperature that exceeds the temperature of the surrounding fluid in the test solution chamber. The invention thereby allows simulation of conditions of heat transfer such as those that exist in heat exchangers of the tube type where the temperature at the inlet end can vary considerably from that at the discharge end. Furthermore, the temperature differentials between the heat exchanger tubes and the surrounding fluid also changes between the inlet and outlet ends. Prior art tests and/or calculations that are based upon only a single temperature will only reflect the conditions existing at a particular portion of a pipe or tube in the heat exchanger. Utilizing the apparatus and method of the present invention, the temperature of the rotating cylinder electrode can be varied by adjusting the heat generated by the heating device over a range of temperature differentials, thereby more accurately replicating actual industrial conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described below and with reference to the attached drawing sheets in which:
FIG. 1 is a schematic elevational view, partly in cross-section, of an embodiment of the invention used with a cylindrical electrode;
FIG. 1A is a further preferred embodiment similar to FIG. 1 illustrating an axially elongated cylindrical electrode for use in the invention;
FIG. 2 is a schematic illustration of the invention similar to FIG. 1 for use with a disk electrode;
FIG. 3 is a schematic illustration of an elevational view of the rotating electrode test assembly with a cylindrical electrode in place and operably connected to a conventional test stand for providing electrical power and rotation to the assembly; and
FIG. 4 is a schematic illustration of a side elevational view of the rotational test electrode assembly utilizing a disk electrode in operating position in a typical test cell.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1 , there is illustrated the rotating test electrode assembly of the invention that is arranged for use with a cylindrical electrode specimen. Conductive member 110 consists of upwardly extending annular member 112 defining an opening 116 and terminating in an integral solid base portion 114 . The lower portion of the conductive member 110 is provided with external threads that cooperatively engage mating internal threads on cylindrical electrode specimen 150 . A protective member 140 extends from the upper mating surface of electrode 150 to a terminus above the end of annular portion 112 .
A heating element 130 is securely positioned in annulas 116 . Electrical leads extend from the heating device 130 to a electrical terminal in the form of socket 138 positioned in the upper end of assembly 100 .
In a preferred embodiment, a plurality of thermocouples 113 are positioned in the conductive member 110 proximate the heating device 130 and the lower end of solid portion 114 proximate the point of attached of the disk electrode, as described below in connection with FIG. 2 .
With continuing reference to FIG. 1 , a second portion of the protective member 140 takes the form of an interiorally threaded polymer cup 144 which is received on the lower end of conductive member 110 to make a fluid-tight contact with the bottom edge of electrode 150 .
With further reference to FIG. 1 , a reinforcing flanged metal sleeve 160 is secured in the upper open end of protective member 140 to provide a rigid point of attachment for a coupling member, as will be described further below. Electrical leads extending from socket 138 are connected to the working electrode at a point 118 in the side wall of annular portion 112 , and to the thermocouple leads.
It is also to be noted that an air gap 148 has provided between the reinforcing sleeve 160 and the hollow cylindrical portion 112 in order to electrically isolate the working electrode 150 from any stray currents that might be produced by the motor or other electrical controls used to power the apparatus.
As will be seen from FIG. 1A , the axial dimension of the cylindrical electrode can be extended as in 150 A, while the protective cup portion 144 A will be reduced in height. This feature of the invention provides added flexibility to the testing of cylindrical electrodes, while still maintaining the ability to utilize the rotational test electrode mounting shaft with a disk electrode, as will be described below.
Referring now to FIG. 2 , it will be seen that the same principal structural elements are utilized for mounting disk electrode 156 on the lower end of conductive member 110 . The threaded orifice 114 receives correspondingly threaded shaft 152 extending from the upper surface of disk electrode 156 . A second portion of the protective member in the form of sleeve 142 is mounted on the lower portion of conductive member 110 and engages the shoulder 154 when the unit is assembled for operation. In this embodiment, it will be understood that the cylindrical electrode 150 has been removed and in its position has been placed protective sleeve 142 which forms a fluid-tight seal with the lower portion of the protective member 140 .
The use of the rotational test electrode assembly will be described in conduction with FIG. 3 in which a rotating disk is to be utilized. As shown in FIG. 3 , the rotational assembly 20 comprises a variable speed motor 22 with speed indicator/controller 21 . A mounting collar 24 couples the output shaft of motor 22 to drive shaft 26 , which can be of any desired length to conveniently position the rotational assembly 20 for the manual attachment and removal of the respective rotational electrodes 100 , and their placement in the polarization cell 40 .
With continuing reference to FIG. 3 , the drive shaft 26 passes through, and is supported for rotation by bearing member 28 that is mounted on supporting plate 36 which can be utilized to conveniently mount the apparatus on a bench, rack or other stable mounting device for convenient access.
A plurality of electrically conductive brushes 30 are mounted in slip-ring mounting member 32 on the drive shaft 26 . As shown best in the cross-sectional view of FIG. 3A , the free-ends of the generally U-shaped brush elements 31 contact the rotating surface of the slip-rings.
The lower end of drive shaft 26 extending from the slip-ring assembly 32 is hollow to receive the plurality of electrical leads (not shown) that are connected to the plug 38 that is fitted to the end of the shaft 26 . Plug 38 mates with socket 138 that is fitted to the end of rotating electrode shaft 140 .
Referring to the schematic illustration of FIG. 4 , the corrosion testing apparatus 10 of the invention comprises a rotational electrode assembly 100 , the lower portion of which has been fitted with a rotating cylindrical electrode (RCE) 150 in accordance with the description provided above, particularly with reference to FIG. 1 .
The rotational assembly 100 is shown positioned in polarization cell 40 . As shown FIG. 4 , polarization cell 40 includes a first chamber 42 for receiving the rotating electrode and a second, smaller chamber 44 separated by a sintered glass member 46 located in a conduit joining the two chambers. The larger chamber 42 is provided with coil 48 through which can be passed a heat transfer fluid provided from an external source (not shown) in order to maintain a predetermined desired temperature differential between the heated electrode and the fluid.
A reference electrode 52 is introduced through a fluid-tight fitting 50 in a sidewall of chamber 42 or, alternatively, through a similar fitting (not shown) in removable cover 60 . A counter electrode (not shown) is positioned in chamber 44 .
Removable cover 60 is received in close-fitting relation over the open end of chamber 42 and is preferably provided with a plurality of openings for receiving in fluid-tight relation the shaft of the rotational assembly 20 , as well as auxiliary devices that can include, e.g., a thermometer or other temperature sensing device; inlet and outlet tubes 48 A and 48 B, respectively, of cooling coil 48 ; gas inlet and removal conduits, e.g., to provide a nitrogen atmosphere for exclusion of oxygen, and to remove any gaseous by-products generated during operation of the apparatus; and to insert the reference electrode and/or other electrodes and probes that may be required for data collection and for alerting the conditions with the vessel 42 .
Appropriately configured stoppers and/or seal members 62 are fitted into unused openings or around projecting tubes and the rotational assembly 100 . A stopper 62 can be inserted to close the open end of smaller chamber 44 .
EXAMPLE
A test cell in accordance with the invention consisting of two compartments was constructed with a first flanged working electrode compartment having a capacity of 2 liters and a 12 cm. diameter; the adjacent second counter electrode compartment being of the same height, had a 2.5 cm. diameter. The two compartments were connected with a tube of 25 mm diameter containing a full bore sintered class disk. The test cell was fabricated from a corrosion resistant, electrically insulative polymeric material.
A rubber stopper 50 was secured in a flanged opening in a side wall adjacent the bottom of the first cell. A capillary tube was passed through the stopper and connected to the reference electrode 52 with its tip that served as a Luggin probe being centrally positioned in the reaction vessel. The cell is carefully filled with a corrosive fluid sample that has been obtained from a heat exchanger feedline.
As in the embodiment illustrated in FIG. 4 , a Luggin probe is shown positioned in close proximity to the RCE specimen. By way of background, the Luggin probe consists of a capillary tube which extends into the cell to a position proximate the electrode, the overvoltage of which is to measured. The capillary tube is connected by a salt bridge to a reference electrode, for example, to a calomel reference electrode, located outside the electrolytic cell. The Luggin probe is suitable for obtaining intermittent measurements, which is sufficient for laboratory testing and data collection purposes. When the RDE is utilized the Luggin probe is positioned below and proximate to the underside of the disk.
The polarization cell cover 60 is positioned below the lower portion of drive shaft 26 , it being understood that the cover does not rotate and is large enough to receive the rotating shaft and an attached RDE or RCE when the polarization cell is brought into operating position below the support plate 36 .
The test cell compartment 40 was covered with a 140 mm diameter flanged lid 60 having a 40 mm diameter central opening to receive the rotating assembly, electrode and driveshaft. Two other 20 mm adjacent openings are provided for use as may be needed for specific tests. The inlet and outlet tubes for the cooling coil were passed through the side wall of the first compartment (not shown).
The rotating electrode supporting shaft 100 is fitted with an internally mounted electric resistance heating device. A protective insulating cover fabricated from PTFE 140 is employed to isolate the conductive member from the effects of the corrosive fluid in which the rotating electrode is to be immersed.
The rotating electrode assembly 100 is joined to the electrical plug 38 through socket 138 . The electrode coupling collar 54 that is mounted on the lower end of drive shaft 26 is secured by thumbscrews 55 to the upper end of shaft 140 .
The rotating electrode assembly 100 is passed through central opening 64 in cover 60 and sliding seal 62 is put in place. The power to the heating device 130 is turned on and thermocouple readings are observed to determine that the RCE has reached the desired temperature. Thereafter, the power to the drive motor 22 is adjusted by controller 21 to obtain the desired revolutions for the testing of the RCE.
After the test has been concluded, the seal 62 is removed and the electrode assembly 100 is withdrawn from the test cell. The thumbscrews 55 on the electrode coupling 54 are released and the socket 138 is separated from the electrical plug 38 . The assembly 100 is then washed and cleaned to remove any residues of corrosive fluid and disassembled to recover the electrode 150 for further testing and analysis.
As will be understood from the above description, the apparatus of the invention provides the following benefits and advantages for both the RDE and RCE devices in a variety of modes of operation:
1. a uniform heat flux emanates from the surface of the cylindrical or disk specimen to the surrounding fluid during operation in the polarization cell; 2. a uniform temperature is provided over the entire surface of the specimen; 3. a uniform boundary layer thickness is presented over the entire specimen surface; 4. the edge of the rotating disk or cylinder shaft has no effect on the uniformity of the boundary layer conditions; 5. no electric current flows from the drive motor to the working electrode; and 6. cylindrical specimens having different heights and associated surface areas can be used interchangeably in a single rotating electrode mounting member.
The apparatus of the invention is prepared for operation and recording of data by filling the test cell with the test fluid, e.g., a corrosive liquid of known composition at a predetermined temperature. The heat transfer fluid is circulated through coils 48 at the same predetermined temperature. The control electrode is inserted into chamber 44 and the rotational electrode fitted with a cylindrical electrode specimen as shown in FIG. 3 is passed through the central opening 64 in cover 60 for immersion in the corrosive test liquid. The Luggin probe is fitted through seal 50 and positioned proximate the cylindrical specimen 110 . Seal 62 is positioned around the rotating shaft assembly 102 . As will be understood from the above description, a single rotational shaft is provided on which can be installed either a disk electrode or cylindrical electrode specimen. The apparatus is capable of evaluating the electrochemical behavior of metals and the performance of corrosion inhibitors under static conditions, hydrodynamic conditions of laminar flow and turbulent flow, isothermal and heat transfer conditions, and combinations thereof.
The apparatus permits the interfacial heat transfer coefficient and interfacial temperature for the cylindrical electrode specimen to be estimated by conventional mathematical modeling and the utilization of analogies among the transport phenomenon for momentum, heat and mass transfer. The apparatus permits data to be collected that is required for conducting quantitative corrosion aid corrosion preventive research for industrial application with a minimum of data manipulation.
It will also be understood from the above description that the apparatus and method of the invention is particularly useful for evaluating corrosion conditions and the effect of inhibitors as applied specifically to industrial cooling systems, e.g., heat exchangers. The apparatus and method of the invention also provides a reliable, reproducible and inexpensive means for evaluating the inhibitive characteristics and compatibility of any of the numerous chemical compounds utilized industrially under conditions that simulate closely those of flow, mass and heat transfer in specific industrial applications.
As will be apparent from the above description to one of ordinary skill in the art, further modifications can be made to the assembly without departing from essential features of the invention as defined in the following claims. | A rotational test electrode assembly for use in a corrosive fluid environment as shown in FIG. 1 that includes a generally cylindrical heat and electrically conductive member ( 110 ) having an annular portion ( 112 ) and a solid portion ( 114 ): a heating device ( 130 ) positioned inside of the annular portion and in heat exchanging relation with the solid portion of the conductive member; a corrosion resistant external protective member ( 140 ) that surrounds a portion of the heat conductive member in close-fitting relationship; mounting means for attaching a rotational electrode ( 150 ) in close fitting heat and electrically conductive relation, the electrode being selected from the group consisting of cylindrical and disk electrodes; and an electrical connector for receiving a plurality of external electrical connectors that is mounted on the protective member opposite the portion of the conductive member on which the rotational electrode is mounted. | 6 |
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to a mower equipped with a cutting bar and having cutting elements extending above a housing, each of the cutting elements being guided and driven in rotation around an axis directed upward by a guiding and driving bearing which includes a casing centered in a corresponding bore made in the upper part of the housing, a guiding bearing mounted in said casing and a shaft guided in said casing with the help of the guiding bearing, said shaft being equipped at its upper end with a fastening part for fastening a corresponding cutting element and at its lower end with a second gear extending inside the housing and meshing with at least one first gear also housed inside said housing, said second gear having an outside diameter which is less than the diameter of the corresponding bore made in the upper part of the housing, each of said guiding and driving bearings being fastened to the upper part of the housing by bolts the shanks of which extend out of the upper part of the housing and nuts screwed on said shanks, said housing being formed by said upper part and a corresponding lower part assembled in a removable way by assembly members.
Discussion of the Background
A mower is known wherein the bolts fastening the guiding and driving bearings to the upper part of the housing, have their heads extending inside said housing and their shanks extending upward while passing through corresponding holes provided in said upper part. Since the bolt is not held in rotation, in order to change a guiding and driving bearing, it is necessary to remove the lower part of the housing to lock the rotation of the bolts, to be able to loosen and then tighten the nuts screwed on the shank of the corresponding bolts. It is understood that this operation can be performed only in a workshop, especially since in general the housing contains a lubricant in which the gears driving the cutting elements in rotation are bathed. This operation will therefore immobilize the machine for a relatively long time at a time precisely when the user has a pressing need for it.
It can then be conceived to fasten the bolts rigidly to the upper part of the housing by welding, for example. This solution, however, is not good for several reasons. A first reason is that the sheet metal constituting the upper part of the housing can be deformed during welding, so that after welding, the shanks of the bolts are not parallel to one another, which will pose problems in having them pass through the passage holes made in the casing of the corresponding guiding and driving bearing. A second reason is that, considering the length of the upper parts of the housing, their manipulation for welding of the bolts is not easy. A third reason is that the shanks of the bolts which extend outside the upper part of the housing can be seriously damaged at the building site or at the dealer's location during storage or handling of the upper part before mounting. In this case, it will be impossible to screw the corresponding nuts on the damaged shanks.
SUMMARY OF THE INVENTION
The object of this invention is to propose a solution that does not have the drawbacks of the prior devices.
For this purpose, the mower according to the invention is characterized by the fact that each bolt fastening the guiding and driving bearings to the upper part of the housing is fastened to a holding element which holds said bolt approximately in the appropriate or desired position and which prevents rotation of said bolt during tightening or loosening of the corresponding nut, said bolt and its holding element constituting a removable assembly.
Thanks to this characteristic, the bolts being used to fasten the guiding and driving bearings to the upper part of the housing will be mounted only at the moment of mounting the cutting bar. Consequently, these bolts cannot be damaged during storage or handling of the upper parts of the housing. It is then possible to loosen and tighten the nuts screwed on these bolts without it being necessary to remove the lower part of the housing because the holding element prevents rotation of the corresponding bolt. In addition, the holding element holds the corresponding bolt approximately in its appropriate position so that the bolt is not in danger of falling into the housing when the corresponding guiding and driving bearing has been removed. Consequently, it is possible for the user to himself change a defective guiding and driving bearing without the machine having to be taken to a workshop so that in case of breakdown of a guiding and driving bearing, the machine will be able to be repaired very quickly. Considering the fact that the bolt and its holding element constitute a removable assembly, it will be possible to change this assembly if the bolt were to become defective.
According to an additional characteristic of the invention, the holding element holds the corresponding bolt approximately in the desired position after mounting of the lower part of the housing on the upper part of said housing. This characteristic particularly allows for the advantage of not increasing the thickness of the housing, although the holding element extends inside the housing.
According to a further characteristic, each holding element is equipped with several bolts.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views and wherein:
FIG. 1 represents a top view of a mower according to the present invention;
FIG. 2 represents a top view on a larger scale of the cutting bar of the mower of FIG. 1 without the cutting elements which have been shown only in dot-and-dash lines;
FIG. 3 represents on a larger scale a view in section taken along line III--III (FIG. 1) of the cutting bar;
FIG. 4 represents a view in section along line IV--IV defined in FIG. 2; and
FIG. 5 represents a view in perspective of a holding element equipped with two bolts.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A mower 1 is shown in FIG. 1 which comprises a cutting bar 2 extending in a known manner under a protective device 3. In this FIG., the device making it possible to connect said cutting bar 2 to a tractor vehicle has not been shown. These devices are actually within the scope of a person skilled in the art.
Cutting bar 2 comprises, as a nonlimiting example, six cutting elements 4, 5 each rotating around an axis 450 (see FIGS. 2 and 3) directed upward, for example in the directions 6, 7. Each cutting element 4, 5 is equipped with two blades 8 and extends above a housing 9 in which it is guided in rotation and which contains driving elements 10 (see FIGS. 2 and 3) intended to drive said cutting elements 4, 5 in rotation.
In FIGS. 2 and 3, it can be seen that housing 9 is formed by an upper part 11 and a lower part 12 which are connected to one another by assembly members 13. After assembly, both parts 11, 12 define an approximately parallelepiped space 14 which contains the driving elements 10. These driving elements 10, in the example shown, consist of a series of cylindrical gears 15 and intermediate cylindrical gears 16 meshing with one another and rotating in lubricant also housing 9. Each gear 15 is connected at lower end 17 of a shaft 18 by splines 19 and by a nut 20. At its upper end 21, shaft 18 is connected to a fastening part 22. This fastening part 22 makes it possible to fasten the corresponding cutting element 4, 5 to shaft 18 by bolts 23.
Shaft 18 is guided in rotation in a guiding bearing 24 which, in the example shown, consists of a two-row, angular-contact ball bearing. This guiding bearing 24 is itself mounted in a casing 25 and is connected at this location in translation by a shoulder 26 and a circlip 27. Casing 25 is centered in a corresponding bore 28 made in the upper part 11 of housing 9 and is fastened to said upper part 11 by assembly elements 29. The diameter of bore 28 is greater than the outside diameter of corresponding gear 15, but is smaller than the outside diameter of flange 250 of casing 25.
The unit, which includes a casing 25, guiding bearing 24, circlip 27 being used to connect this guiding bearing 24 to casing 25, shaft 18, fastening part 22, gear 15 and nut 20 forms a guiding and driving bearing 30. Guiding and driving bearing 30 can be mounted or removed from housing 9 through the top since the outside diameter of gear 15 is smaller than the diameter of corresponding bore 28.
As can be seen in FIGS. 2 to 5, assembly elements 29 that are used to fasten a casing 25 to upper part 11 of housing 9 comprise, in particular, bolts 31 and nuts 32. In the example shown, each casing 25 is fastened by four bolt 31-nut 32 assemblies. Each bolt 31 has a head 33 which extends inside the parallelepiped space 14 and a shank 34 which extends out of upper part 11 of housing 9 by passing through a corresponding hole 35 provided for this purpose in upper part 11. To hold bolts 31 in their appropriate position, they are fastened in the example shown, by welding) to holding elements 36. In this example, each holding element 36 is equipped with two bolts 31 so that for each casing 25, there are two holding elements 36. Each holding element 36 consists of a bracket wherein one wing 37 thereof extends approximately horizontally and supports bolts 31 and the other wing 38 extends approximately vertically between upper part 11 and lower part 12 of housing 9. In FIGS. 3 and 4, it can be seen that the height of holding element 36, i.e., in the example shown, the length of vertical wing 38, is approximately equal to the inside thickness of housing 9. As stated, each holding element 36 is equipped with two bolts 31 and the fastening of each guiding and driving bearing 30 therefore requires two holding element 36-bolt 31 assemblies. In FIG. 2, it can be seen that these holding elements 36 extend approximately parallel to the longitudinal axis of housing 9, to make possible the meshing between corresponding gear 15 and neighboring intermediate gears 16. In addition, it is seen in FIGS. 2 and 5 that horizontal wing 37 of a holding element 36 comprises a circular recess 39 centered on the axis of rotation 450 of corresponding gear 15 and with a radius slightly larger than the radius of said gear 15.
Finally, in FIG. 4, it can again be seen that at the location where shank 34 of a bolt 31 extends out of upper part 11 of housing 9, shank 34 has an approximately semicircular groove 340 in which an O-ring 341 is mounted. At the same time, corresponding passage hole 251 provided in flange 250 of corresponding casing 25, includes, at the position where it extends out of the face of said flange 250 intended to come in contact with upper part 11 of housing 9, a beveled portion 252. Thus, during mounting of guiding and driving bearing 30 on upper part 11 of housing 9, O-ring 341 fills the space created between groove 340 and corresponding beveled portion 252 and thereby obtains a perfect seal preventing any leakage of lubricant contained in housing 9.
Mounting of cutting bar 2 which has just been described is performed in the following manner: the upper part 11 of housing 9 is placed upside down; the various intermediate gears 16 are mounted; the holding element 36-bolt 31 assemblies are put in place, i.e., shanks 34 of bolts 31 are introduced in corresponding holes 35 made in upper part 11; lower part 12 is placed on upper part 11 and these two parts are assembled with assembly members 13; and then the unit is turned over so that upper part 11 is now on top. In this position, bolts 31 will be held approximately in their desired position by corresponding holding elements 36, since said holding elements 36 have a height approximately equal to the inside thickness of housing 9. Then, previously preassembled guiding and driving bearings 30 are mounted and are fastened with nuts 32 that are screwed on shanks 34 of corresponding bolts 31. This is possible because during the tightening of a nut 32 on shank 34 of a bolt 31, the latter is prevented from rotation by corresponding holding element 36 and by the other bolt 31 with which this holding element 36 is also equipped. Finally, cutting elements 4, 5 are fastened to corresponding guiding and driving bearings 30 with bolts 23.
If during operation a guiding and driving bearing 30 becomes defective, the user will be able to himself change it very quickly without it being necessary to remove entirely cutting bar 2. The mower will therefore be able to be repaired in the field itself and at less cost.
To do this, it will actually suffice to remove cutting element 4, 5 corresponding to the defective guiding and driving bearing 30; remove the nuts 32; take out the defective guiding and driving bearing 30; mount a new guiding and driving bearing 30; screw the nuts 32 again on shanks 34 of corresponding bolts 31; and mount the corresponding cutting element 4, 5.
In FIG. 2, there can also be seen the shape of fastening part 22 of each guiding and driving bearing 30 making possible the fastening of corresponding cutting element 4, 5. This shape is such that nuts 32 being used for the fastening of a guiding and driving bearing 30 to upper part 11 of housing 9, are easily accessible from the top. This makes possible the use of motor-driven screwdrivers during mounting of the cutting bar 2 and, therefore, contributes to reducing the mounting costs. In the example shown, fastening part 22 comprises four flat surfaces 40 which impart to said fastening part 22 in a top view an approximately square general shape. This special shape makes possible simultaneous access to four nuts 32 so that it will be possible to use special screwdrivers with four tightening heads for a simultaneous tightening of four nuts 32.
Cutting bar 2 which has just been described above can be used in a standard mower, in a mower-windrower or in a mower conditioner.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | A mower including a housing and an assembly for fastening guiding and driving bearings to an upper part of the housing. The assembly includes plural bolts each fastened to a holding element which holds each bolt approximately in its appropriate position and which prevents rotation of each bolt during the tightening or loosening of the nut. The bolt and its holding element constitute a removable assembly. | 5 |
[0001] The present invention relates to a camshaft adjusting device having a camshaft adjuster, which includes a stator, a rotor which is rotatable relative to the stator around a rotation axis, and a hub situated on the rotor or on the stator and having a receiving bushing, as well as a camshaft accommodated in the receiving bushing. In particular, the present invention deals with the problem of centering the camshaft adjuster on the camshaft.
BACKGROUND
[0002] Via the hub, the camshaft adjuster of a camshaft adjusting device of the type mentioned at the outset is rotatably fixedly connected to the crankshaft of an internal combustion engine. The phase angle between the crankshaft and the camshaft may be set with the aid of the relative rotatability of the rotor relative to the stator.
[0003] A camshaft adjusting device is known from DE 101 617 01 A1, in which the camshaft is accommodated in a receiving bushing in the rotor of the camshaft adjuster for the purpose of centering with the aid of the camshaft adjuster. The receiving bushing of the hub is designed as a centering opening having an uninterrupted circular surface. The centering opening additionally has an area which is reduced in diameter for the purpose of centering. The camshaft is fixed on the rotor with the aid of a central screw.
SUMMARY OF THE INVENTION
[0004] It is an object of the present invention to provide a camshaft adjusting device which is easy and economical to manufacture and which permits a preferably secure centering of the camshaft or the camshaft adjuster on the camshaft.
[0005] The present invention provides a camshaft adjusting device of the type mentioned at the outset in which the camshaft is radially fixed in the receiving bushing with the aid of at least three spacer elements.
[0006] In a first step, the present invention is based on the consideration that a receiving bushing of the hub, into which the camshaft is centrically inserted, must be manufactured or machined within very narrow tolerances, so that the inserted camshaft does not generate an imbalance with respect to the rotation axis of the camshaft adjuster. The required low tolerances are achieved in terms of manufacturing by complex manufacturing or machining. For example, the receiving bushing must be rotated to achieve the necessary low tolerances on the circumferential line. This disadvantageously increases the costs and the cycle times for manufacturing.
[0007] In a second step, the present invention recognizes that, if the camshaft is to be centrically accommodated on the camshaft adjuster, a rotation may be dispensed with according to the operating principle of a chuck. If the camshaft is fixed radially in the receiving bushing with the aid of at least three spacer elements, the receiving bushing as such no longer has to be manufactured with the required low tolerances. Instead, the spacer elements establish the radial position of the camshaft. In other words, an interrupted centering surface is provided, so that a rotation of the receiving bushing is no longer needed for manufacturing. Only the small number of spacer elements must be manufactured in a defined manner with respect to their radial contact surfaces or contact points.
[0008] In particular, the present invention makes it possible to manufacture the hub including the receiving bushing or the rotor or the stator including the receiving bushing without machining or with the aid of a cost-effective sintering. The corresponding individual parts are initially powder-metallurgically pressed into mold parts to form a green compact and subsequently sintered. Only the tolerances of the interrupted centering surface, i.e., of the radial contact surfaces or contact points of the spacer elements as well as, if necessary, the base of the receiving bushing are subsequently set with the aid of a form tool. The form tool may be, for example, a mandrel, a stamp or a die. This setting of the tolerances is also known under the term “calibration.”
[0009] In other words, the present invention also provides a method for manufacturing a camshaft adjusting device of the type mentioned at the outset, a rotor and a stator being provided and assembled, rotatable relative to one another, to form a camshaft adjuster, and the camshaft adjuster being centered on a camshaft. According to the present invention, it is provided that a hub, which includes a receiving bushing and at least three spacer elements, is powder-metallurgically manufactured for the rotor or for the stator, that the radial tolerances of the spacer elements are set with the aid of calibration and that the camshaft is introduced into the receiving bushing and fixed radially with the aid of the spacer elements.
[0010] The rotor or the stator itself, or only the corresponding hub parts, may be powder-metallurgically manufactured. The spacer elements are preferably manufactured together with the receiving bushing, and the radial tolerances of the spacer elements manufactured together with the receiving bushing are set with the aid of calibration. However, it is also possible to manufacture the spacer elements separately and to subsequently insert them into the receiving bushing. The spacer elements may also be mounted on or manufactured together with the camshaft. The spacer elements may be mounted, for example, on a support or the like, which may be inserted into the receiving bushing as a component independent of the camshaft adjuster. In this way, a centering having an accuracy which is independent of the remaining components of the camshaft adjuster may be achieved. It is also possible to introduce the spacer elements radially between the wall of the receiving bushing and the camshaft entirely without fastening. After the radial tolerances of the spacer elements are set, the camshaft is introduced into the receiving bushing and fixed radially.
[0011] In one preferred embodiment of the present invention, at least two of the spacer elements are situated offset from each other in the axial direction. Due to this measure, the camshaft is definitively fixed in its axial alignment, in particular aligned along the rotation axis without a tilt. In the case of a punctiform support of the camshaft on spacer elements situated in an axial plane, mechanical deformation may possibly cause an indeterminacy in the axial direction of the camshaft.
[0012] In one advantageous refinement, the spacer elements extend in the axial direction. This permits a concrete fixing of the camshaft in the axial direction, since, in the axial direction, the camshaft is guided along the spacer element, for example at multiple points or on a surface or an edge.
[0013] The spacer elements advantageously taper toward the camshaft in the radial direction for the purpose of minimizing the active contact surface between the spacer elements and the camshaft, so that multiple contact points with the camshaft, which over-determine the centering of the camshaft, do not occur on the individual spacer elements themselves. The thickness of the spacer elements preferably tapers on a plane perpendicular to the axial direction, while retaining a certain axial extension, so that an axial contact line toward the camshaft results on each of the spacer elements.
[0014] In an additional refinement, the spacer elements extend in the axial direction to a base of the receiving bushing, indentations being introduced into the base, which surround each of the spacer elements. In other words, the indentations are situated directly in the root area of the spacer elements. The indentations in the root area of the spacer elements may also be provided by sintering and/or pressing. The indentations facilitate a flat contact of the front side of the camshaft on the base of the receiving bushing, without an edge-carrying outer rim of the camshaft striking in the radial transition in the root area. Upon finally tightening a camshaft mounted on an edge seat in the root area, for example with the aid of a central screw, the camshaft may undesirably tilt or twist later on, which may result in serious subsequent damages.
[0015] At least one form-fitting element is furthermore advantageously situated on a base of the receiving bushing, which is rotatably fixedly coupled with a complementary form-fitting element on the front of the camshaft. Due to the additional form fit between the front and the base of the receiving bushing, higher torques may be transmitted than in the case of a flat support. A form fit of this type also permits an angle-coded installation of the camshaft. For this purpose, the form-fitting elements are designed in such a way that the camshaft may be inserted into the receiving bushing all the way to the base only in one single, defined angular position. The phase angle of the camshaft on the camshaft adjuster may be predefined thereby, for example during assembly.
[0016] The form-fitting elements situated on the base may, in particular, also taper in the axial direction, so that, when the camshaft is tightened on the camshaft adjuster, for example with the aid of a central screw, they bore, dig or cut into the front side, thereby compensating for any tolerances that may exist.
[0017] In one refinement of the present invention, the spacer elements are situated on an inner lining of the receiving bushing and may particularly preferably be provided as a single piece with the inner lining. In this way, the rotor or the stator may be manufactured using a simple sintering process, the individual spacer elements being brought to the tolerances necessary for centering the camshaft after the sintering process with the aid of calibration.
[0018] In one advantageous embodiment, the receiving bushing is situated on a rotor of the camshaft adjuster. In this case, the camshaft adjuster is mounted together with the rotor on the camshaft, the latter being accommodated in a centered manner in the receiving bushing of the rotor. The stator is then driven by the crankshaft, in particular using a chain drive. The angle between the camshaft and the crankshaft is set with the aid of the phase angle of the rotor relative to the stator. Alternatively, the receiving bushing may be situated in a stator if the stator must be accommodated centrally or centered relative to the camshaft. The stator is then joined directly to the camshaft or supported on it radially. This is the case, in particular, in a camshaft which surrounds an inner shaft and an outer shaft concentric thereto, the stator being connected to the inner shaft and the rotor to the outer shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Exemplary embodiments of the present invention are explained in greater detail below on the basis of a drawing.
[0020] FIG. 1 shows a schematic representation of an internal combustion engine including camshaft adjusters;
[0021] FIG. 2 shows a radial sectional view of one camshaft adjuster from FIG. 1 ;
[0022] FIG. 3 shows an axial sectional view of the camshaft adjuster from FIG. 2 ;
[0023] FIG. 4 shows an axial top view of a hub of an alternative rotor of the camshaft adjuster from FIG. 2 ;
[0024] FIG. 5 shows a perspective view of the hub from FIG. 4 ; and
[0025] FIG. 6 shows a broken open perspective view of the hub from FIG. 4 .
DETAILED DESCRIPTION
[0026] In the figures, the same elements are provided with the same reference numerals and described only once.
[0027] Reference is hereby made to FIG. 1 , which shows a schematic representation of an internal combustion engine 2 , including camshaft adjusters 4 .
[0028] In a manner which is known per se, internal combustion engine 2 includes a combustion chamber 6 , which may be opened and closed with the aid of valves 8 . The valves are activated by cams 10 on corresponding camshafts 12 . A reciprocating piston 14 , which drives a crankshaft 16 , is accommodated in combustion chamber 6 . The rotation of crankshaft 16 is transmitted on its axial end to camshaft adjusters 4 via driving means 18 . In the present example, the driving means may be a chain or a belt.
[0029] Camshaft adjusters 4 are each mounted axially on camshafts 12 , absorb the rotation energy of driving means 18 and transfer it to camshafts 12 . Camshaft adjusters 4 are thus able to temporarily decelerate or accelerate the rotation of camshafts 12 with respect to crankshaft 16 for the purpose of changing the phase angle of camshafts 12 with respect to crankshaft 16 .
[0030] Reference is hereby made to FIGS. 2 and 3 , which show a radial and axial sectional view of one of camshaft adjusters 4 from FIG. 1 .
[0031] Camshaft adjuster 4 is mounted on camshaft 12 . Camshaft adjuster 4 and camshaft 12 together form camshaft adjusting device 19 . In the present description, the axial end of camshaft 12 , on which camshaft adjuster 4 is mounted, is defined as the “front” and the end opposite this axial end is defined as the “rear.”
[0032] Camshaft 12 has multiple A supply connections 20 and one B supply connection, which is not illustrated, in the form of radial bores guided through the camshaft. The two supply connections 20 may be connected to a pressure port, which is not illustrated, and to a tank connection, which is not illustrated, in a manner which is known to those skilled in the art, for example via a 4/3-way valve. An axial stop 22 is furthermore provided axially upstream from A supply connections 20 , via which the camshaft may be counter-supported in a bearing block, which is not illustrated.
[0033] Camshaft 12 furthermore has a stepped, axial central bore 24 , one step 26 of stepped central bore 24 being provided axially between A supply connections 20 and the B supply connection, which is not illustrated. An inner thread 28 , into which a central screw or a central valve body 30 having an outer thread 31 is screwed, is provided behind step 26 in central bore 24 . Camshaft adjuster 4 is fastened to camshaft 12 in a manner which is still to be described via the central screw or central valve body 30 .
[0034] An annular gap 32 is provided axially in front of step 26 between central screw 30 and a wall of central bore 24 . The B supply connection, which is not illustrated, is inserted into this annular gap 32 in a manner which is not shown.
[0035] Furthermore, four axial bores 34 , which are spaced equidistantly apart in the circumferential direction of camshaft 12 and which are each connected on their front axial end to one of A supply connections 20 , penetrate camshaft 12 radially via central bore 24 .
[0036] Camshaft adjuster 4 has a stator 36 and a rotor 38 , which is rotatably accommodated in stator 36 .
[0037] Stator 36 has an annular outer part 40 , from which multiple separating elements 42 project radially to the inside. Only one of these separating elements 42 is shown in FIG. 2 . Screws 44 , which are provided to fasten a front cover 46 on the front of stator 36 and a sealing cover 48 on the back of stator 36 , axially penetrate separating elements 42 . An inner chamber surrounded by the annular outer part is axially closed in this way. Teeth 50 are provided on the radial outside of annular outer part 40 , which are able to engage with driving means 18 .
[0038] As mentioned above, rotor 38 is accommodated in stator 36 and rotatably fixedly connected to camshaft 12 with the aid of the central screw or central valve body 30 . Rotor 38 has a hub 52 , from which vanes 54 project radially and which engages between separating elements 42 of stator 36 , viewed in the circumferential direction of camshaft adjuster 4 . Pressure chambers are formed in this way, via which rotor 38 may be adjusted with respect to stator 36 by pumping in hydraulic fluid. Viewed in the direction of rotation of camshaft adjuster 4 , a pressure chamber upstream from a vane 54 is referred to as a retarding chamber, and a pressure chamber downstream from a vane 54 is referred to as an advancing chamber. FIG. 2 shows a pressure chamber, which is to be assumed to be retarding chamber 56 .
[0039] Gap 32 is continued in rotor 38 . Radial retarding bores 58 , which lead into retarding chambers 56 , penetrate hub 52 from the gap. Only two of these retarding bores 58 are shown in FIG. 2 . Some of axial bores 34 through camshaft 12 are also continued into rotor 38 36 . Radial advancing bores 60 , which lead into the advancing chambers, penetrate hub 52 from axial bores 34 . Only one of advancing bores 60 is shown in FIG. 2 . If hydraulic fluid is thereby pumped into camshaft adjuster 4 via A supply connections 20 , the advancing chambers, which are not illustrated, are pressurized, and camshaft 12 is accelerated with respect to crankshaft 16 , which is connected to stator 36 via driving means 18 . In contrast, camshaft 12 is decelerated when hydraulic fluid is pumped into retarding chambers 56 via the B supply port, which is not illustrated.
[0040] To avoid camshaft adjuster 4 generating imbalances during the rotation of camshaft 12 , camshaft adjuster 4 must be mounted on camshaft 12 centrically to rotation axis 74 . For this purpose, hub 52 of rotor 38 has a receiving bushing 62 , which is axially indented from the back of camshaft adjuster 4 and into which camshaft 12 is inserted. Within receiving bushing 62 , camshaft 12 is supported by three spacer elements 64 , which radially fix camshaft 12 with respect to rotor 38 and thus to camshaft adjuster 4 . Hub 52 with receiving bushing 62 and spacer elements 64 situated on the inner wall of receiving bushing 62 is manufactured by sintering. The radial dimensions of spacer elements 64 are set by calibration after the sintering process.
[0041] Spacer elements 64 will be discussed in greater detail on the basis of FIGS. 4 through 6 .
[0042] FIGS. 4 through 6 show another example of a hub 52 of rotor 38 of camshaft adjuster 4 in an axial top view, in a perspective view and in a broken open perspective view.
[0043] In FIGS. 4 through 6 , hub 52 has five vane grooves 66 , into which vanes 54 may be inserted. In this way, five advancing chambers and five retarding chambers 56 may be formed by a corresponding stator 36 , which has five separating elements 42 . These adjusting chambers are supplied with hydraulic fluid through five advancing bores 60 and five retarding bores 58 . Correspondingly, five axial bores 34 , which are connectable to A supply connection 20 in the manner described in FIG. 2 , lead to five advancing bores 60 . Five retarding bores 58 lead into gap 32 described in FIG. 2 , which is connectable to the B supply connection.
[0044] An axial locking pin bore 68 is furthermore provided in hub 52 , in which a locking pin, which is not illustrated, may be guided, which is able to secure a certain rotational position of stator 36 with respect to rotor 38 in a manner which is known to those skilled in the art.
[0045] In the present embodiment, spacer elements 64 are designed to taper radially to the inside and be spaced a distance apart at a 120° angle 70 . Spacer elements 64 extend in the axial direction. An axially running line results for each spacer element 64 as the contact surface for an essentially cylindrical camshaft 12 . The radial position and angular position of camshaft 12 are definitively established via the three spacer elements 64 . Radial height 72 of spacer elements 64 may decrease in the axial direction counter to the joining direction of camshaft 12 in a manner which is not illustrated. In this way, spacer elements 64 may grip camshaft 12 during insertion into receiving bushing 62 and center it with respect to a center point 74 or a rotation axis 74 .
[0046] Axial indentations 76 are introduced around the bottom or root area of spacer elements 64 , which rest on base 63 of receiving bushing 62 . These axial indentations 76 facilitate a flat support of the front of camshaft 12 on base 63 . An undesirable impact of an outer edge of camshaft 12 on the radial transition in the root area of spacer elements 64 is avoided.
[0047] According to FIG. 5 , a form-fitting element 65 is provided on base 63 of receiving bushing 62 , which forms a form fit with a complementary form-fitting element on the front of camshaft 12 when camshaft 12 is inserted. The form fit formed hereby on the front of inserted camshaft 12 permits the transmission of higher torques. Due to single form-fitting element 65 , the mounting of camshaft 12 in receiving bushing 62 is possible in only one specific rotational position.
[0048] To manufacture illustrated hub 52 , hub 52 may initially be sintered with spacer elements 64 . Radial height 72 of spacer elements 64 may then be calibrated, for example using a noncutting machining method with the aid of a suitable form tool. To finish rotor 38 , vanes 54 may be inserted into vane grooves 66 in hub 52 . After mounting rotor 38 in a stator 36 (see FIG. 2 ), camshaft 12 may be introduced into receiving bushing 62 and fixed radially. Camshaft 12 may then be tightened axially with the aid of a central screw or a central valve body 30 .
LIST OF REFERENCE NUMERALS
[0000]
2 Internal combustion engine
4 Camshaft adjuster
6 Combustion chamber
8 Valve
10 Cam
12 Camshaft
14 Reciprocating piston
16 Crankshaft
18 Driving means
19 Camshaft adjusting device
20 A supply connection
22 Axial stop
24 Central bore
26 Axial step
28 Inner thread
30 Central screw
31 Outer thread
32 Gap
34 Axial bore
36 Stator
38 Rotor
40 Outer part
42 Separating element
44 Screw
46 Front cover
48 Sealing cover
50 Tooth
52 Hub
54 Vane
56 Retarding chamber
58 Retarding bore
60 Advancing bore
62 Receiving bushing
63 Base
64 Spacer elements
65 Form-fitting element
66 Vane groove
68 Axial locking pin bore
70 Angle
72 Radial height
74 Rotation axis
76 Axial indentation | A camshaft adjusting device ( 19 ) having a camshaft adjuster ( 4 ), including a stator ( 36 ), a rotor ( 38 ) which can be rotated relative to the stator ( 36 ) about a rotational axis ( 74 ), and a hub ( 52 ) which is arranged on the rotor ( 38 ) or on the stator ( 36 ) and has a receiving cup ( 62 ), and having a camshaft ( 12 ) which is received in the receiving cup ( 62 ). It is provided here that the camshaft ( 12 ) is fixed radially in the receiving cup ( 62 ) via at least three spacer elements ( 64 ). A camshaft adjusting device ( 19 ) of this type can be produced simply and inexpensively. | 5 |
BACKGROUND OF THE INVENTION
1.) Field of the Invention
The present invention relates to a process for selectively preparing racemic or optically active cis-azole derivatives which are active ingredients of agricultural and horticultural compositions, and to intermediates for preparing the azole derivatives, a process for preparation thereof, and fungicidal compositions.
2) Description of the Related Art
Azole derivatives represented by the following general formula (I) have heretofore been known to have excellent agricultural and horticultural fungicidal effects and plant growth controlling effects, and a process for preparation thereof has been known too. ##STR3## wherein R 1 and R 2 mean a hydrogen atom or an alkyl group, independently, R denotes a halogen atom, a nitro group, independently, R denotes a halogen atom, a nitro group, a cyano group, an alkyl group, a haloalkyl group or a phenyl group, A denotes a nitrogen atom or a methine group, and n stands for 0 or an integer of 1-5.
Namely, EP-A-329397 discloses a process for preparation of a racemic mixture of cis-azole derivatives and trans-azole derivatives represented by the above general formula (I), and EP-A-267778 discloses a process for preparation of cis- or trans-azole derivatives represented by the general formula (I') ##STR4## wherein R 1' and R 2' denote each a C 1 -C 5 alkyl group or a hydrogen atom, but R 1' and R 2' are not hydrogen atom at the same time, X' denotes a halogen atom, a C 1 -C 5 alkyl group or a phenyl group, n' stands for 0 or an integer of 1 or 2, and A' denotes a nitrogen atom or a methine group,
which comprises using cis- or trans-oxaspiroheptane derivatives represented by the general formula (II') ##STR5## wherein R 1' and R 2' , X' and n have the same meanings as defined above.
It has been known that the azole derivatives represented by the general formula (I) has a higher activity in the cis form than in the trans form.
It is therefore desired to provide a process by which cis-form azole derivatives represented by the general formula (I) having a higher fungicidal activity are selectively prepared. In the process described in EP-A-329397, however, since a mixture of cis form and tans form is prepared, the yield of the cis form is reduced under the influence of the by-produced trans form and it is necessary to separate the cis-azole derivatives from the mixture of the cis form and trans form. Further, in the process described in Japanese Patent Application Laid-Open No. 93574/1989, a process for separating the cis form is required in a stage of preparing oxaspiroheptane derivatives represented by the general formula (II') in order to obtain the cis azole derivatives.
As be described above, the prior processes require a separation step for obtaining purified cis form. In the separation step, large amounts of column packings or solvents are used and a loss is caused when separation is carried out. Accordingly, it is not advantageous to combine the separation step in the indusutrial process for preparation of the cis form.
The present invention has been achieved in the light of the above described circumstances in the prior arts.
SUMMARY OF THE INVENTION
An object of the present invention is therefore to provide a process for selectively preparing cis-azole derivatives represented by the general formula (I) which show reliable effects in a smaller amount because of having a high fungicidal activity, by which the amount existent in the environment becomes small.
Another object of the present invention is to provide intermediates useful for producing the cis-azole derivatives
A further object of the present invention is to provide processes for preparation of the intermediates.
A still further object of the present invention is to provide a fungicidal composition.
The present inventors have noticed the fact that the cis-azole derivatives represented by the general formula (I) has a higher effectiveness as compared with trans-azole derivatives which are geometrical isomers. As a result of earnest studies concerning the process for selective preparation in order to solve the above mentioned problems, it has found a process by which only cis form can be prepared, leading to completion of this invention.
With respect to configuration of the azole derivatives represented by the general formula (I) in the present specification, cis form means those wherein a substituted or non-substituted phenylmethyl group is bonded to the cis position of the hydroxyl group attached on the cyclopentane ring, and trans form means those wherein said group is bonded to the trans position of the hydroxyl group attached on the cyclopentane ring.
The characteristic of the present invention is as follows.
In one aspect of this invention, there is thus provided a process for preparing a cis-azole derivatives represented by the general formula (I) ##STR6## wherein R 1 and R 2 denotes each a hydrogen atom or an alkyl group, R denotes a halogen atom, a nitro group, a cyano group, an alkyl group, a haloalkyl group or a phenyl group, A denotes a nitrogen atom or a methine group, and n stands for 0 or an integer of 1-5,
which comprises subjecting an oxaspiroheptane derivative represented by the general formula (II) to a rearrangement reaction ##STR7## wherein R 1 , R 2 , R, and n have the same meanings as defined above,
epoxidating the resultant cyclopentenemethanol derivative represented by the general formula (III) ##STR8## wherein R 1 , R 2 , R, and n have the same meanings as defined above,
conducting sulfonic esterification of the resultant oxabicyclohexanemetanol derivative represented by the general formula (IV) ##STR9## wherein R 1 , R 2 , R, and n have the same meanings as defined above,
sujecting to a substitution reaction the resultant oxabicyclohexanemethanol sulfonic acid ester derivative represented by the general formula (V) with a 1,2,4-triazole or imidazole ##STR10## wherein R 1 , R 2 , R, and n have the same meanings as defined above, and Y denotes an alkyl group or a nonsubstituted or substituted phenyl group,
and reducing the resultant azolylmethyloxabicyclohexane derivative represented by the general formula (VI) ##STR11## wherein R 1 , R 2 , R, A and n have the same meanings as defined above.
In another aspect of this invention, there is also provided a process for preparing a cis-azole derivatives represented by the above-mentioned general formula (I) which comprises reducing an azolylmethyloxabicyclohexane derivative represented by the general formula (VI) ##STR12## wherein R 1 , R 2 , R, A and n have the same meanings as defined above.
In a further aspect of this invention, there is also provided an azolylmethyloxabicyclohexane derivative represented by the general formula (VI) ##STR13## wherein R 1 , R 2 , R, A and n have the same meanings as defined above.
In a further aspect of this invention, there is also provided a process for preparing an azolylmethyloxabicyclohexane derivative represented by the above described general formula (VI) which comprises sujecting to a substitution reaction an oxabicyclohexanemethanol sulfonic acid ester derivative represented by the general formula (V) with a 1,2,4-triazole or an imidazole. ##STR14## wherein R 1 , R 2 , R, and n have the same meanings as defined above, and Y denotes an alkyl group or a nonsubstituted or substituted phenyl group.
In a further aspect of this invention, there is also provided an oxabicyclohexanemetanol sulfonic acid ester derivative represented by the general formula (V) ##STR15## wherein R 1 , R 2 , R, n and Y have the same meanings as defined above.
In a further aspect of this invention, there is also provided a process for preparing an oxabicyclohexanemetanol sulfonic acid ester derivatives represented by the above described formula (V) which comprises conducting sulfonic esterification of an oxabicyclohexanemethanol derivative represented by the general formula (IV) ##STR16## wherein R 1 , R 2 , R, and n have the same meanings as defined above.
In a further aspect of this invention, there is also provided an optically active oxabicyclohexanemethanol deirvative represented by the general formula (IV) ##STR17## wherein R 1 , R 2 , R, and n have the same meanings as defined above.
In a further aspect of this invention, there is also provided a process for preparing an oxabicyclohexanemethanol derivative represented by the above described general formula (IV) which comprises epoxidating a cyclopentenemethanol derivative represented by the general formula (III) ##STR18## wherein R 1 , R 2 , R, and n have the same meanings as defined above.
In a further aspect of this invention, there is also provided a cyclopentenemethanol deirvative represented by the general formula (III) ##STR19## wherein R 1 , R 2 , R, and n have the same meanings as defined above.
In a further aspect of this invention, there is also provided a process for preparing a cyclopentenemethanol derivative represented by the above described general formula (III) which comprises subjecting an oxaspiroheptane derivative represented by the general formula (II) to a rearrangement reaction ##STR20## wherein R 1 , R 2 , R, and n have the same meanings as defined above.
In a still further aspect of this invention, there is also provided a fungicidal composition comprising as an effective ingredient an azolylmethyloxabicyclo-hexane derivative represented by the following formula (VI) together with an inert carrier or adjuvants; ##STR21## wherein R 1 , R 2 , R, A and n have the same meanings as defined above.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The process for preparing the cis-azole derivative represented by the above described general formula (I) is shown as the following reaction formulas. ##STR22##
In the following, the present invention will be illustrated in greater detail.
The cis-azole derivative represented by the general formula (I) and intermediates thereof of the present invention will be first explained. In the azole derivatives represented by the above-mentioned general formula (I), R 1 and R 2 mean a hydrogen atom or an alkyl group, and preferably a hydrogen atom or an C 1 -C 3 alkyl group. R means a halogen atom, a nitro group, a cyano group, an alkyl group, a haloalkyl group or a phenyl group, and preferably a chlorine atom bonded to the 4-position.
n is 0 or an integer or from 1 to 5 and preferably 0-1. A means a nitrogen atom or a methine group.
In the intermediates represented by the above-mentioned general formulas (II), (III), (IV), (V) and (VI), the substituents R 1 , R 2 and R, n and A have the same meanings as those in the azole derivative represented by the general formula (I), and preferred embodiments are also the same. In the oxabicyclohexanemethanol sulfonic acid ester derivative represented by the general formula (V), Y means an alkyl group or a non-substituted or substituted phenyl group, and preferably a C 1 -C 4 alkyl group, a phenyl group or a p-methylphenyl group. The process of the present invention will be explained in the following in accordance with the above-mentioned reaction formulas
Rearrangement Reaction
The oxaspiroheptane derivative represented by the general formula (II) can be changed into the cyclopentene methanol derivatives represented by the general formula (III) by a rearrangement reaction in a presence of an acid catalyst in an organic solvent at a reaction temperature in a range of from 0° C. to 40° C. for a reaction time in a range of from 1 hour to 5 hours. As the organic solvent, ethers can be used. Particularly preferred examples include dioxane, tetrahydrofuran (THF) and diethyl ether. As the acid catalyst, it is possible to use, for example, sulfuric acid, hydrochloric acid, AlCl 3 , BF 3 and the like.
Epoxidation Reaction
The oxabicyclohexanemethanol derivative represented by the general formula (IV) is obtained by epoxidation of the cyclopentenemethanol derivative represented by the general formula (III) using an inorganic or organic peroxide in an organic solvent at a reaction temperature in a range of from -78° C. to 25° C. for a reaction time in a range of from 1 hour to 5 hours.
Examples of the organic solvents include alkyl halides such as dichloromethane or dichloroethane etc., aromatic hydrocarbons such as toluene etc., aliphatic hydrocarbons such as hexane, heptane or isooctane etc. As the peroxide, it is possible to use metachloroperbenzoic acid, cumene hydroperoxide and tertiary butyl hydroperoxide and the like.
Furthermore, when the epoxidation is carried out using an asymmetric reagent, it is possible to obtain an optically active oxabicyclohexanemethanol derivative represented by the general formula (IV). For example, an optically active (+)-oxabicyclohexanemethanol derivative represented by the general formula (IV) can be obtained by carrying out the epoxidation reaction using as an asymmetric reagent a combination of (2R,3R)-(+)-diethyl tartarate and titanium tetraisopropoxide. Likewise, an optically active (-)-oxabicyclohexanemethanol derivative represented by the general formula (IV) can be obtained by carrying out the epoxidation reaction using as an asymmetric reagent a combination of (2S,3S)-(-)-diethyl tartarate and titanium tetraisopropoxide.
In such cases, the above-mentioned combination of the reagents can be used together with Molecular seives.
Using the thus resulted optically active oxabicyclohexanemethanol derivative represented by the general fromula (IV), the optically active cis-azole derivative represented by the general formula (I) can be prepared by the sulfonic esterification, the azolation reaction and the reduction reaction in accordance with the above-mentioned chemical formulas as follows.
Sulfonic Esterification Reaction
The oxabicyclohexanemethanol sulfonic acid ester derivatives can be obtained by subjecting the oxabicyclohexanemethanol derivative represented by the general formula (V) to sulfonic esterification in an organic solvent using benzenesulfonyl chloride, substituted benzenesulfonyl chloride or alkanesulfonyl chloride and a hydrochloric acid binding agent at a reaction temperature in a range of from 0° C. to 40° C. for a reaction time in a range of from 0.5 hours to 5 hours.
A preferred example of the substituted benzenesulfonyl chloride is p-methylbenzenesulfonyl chloride, and a preferred example of the alkanesulfonyl chloride is methanesulfonyl chloride.
Examples of the hydrochloric acid binding agent include trimethylamine, triethylamine, N,N-dimethylaniline and N,N-diethylaniline, etc., but the present invention is not limited to using them.
Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene and xylene, etc., aliphatic hydrocarbons such as hexane, heptane and isooctane etc., alkyl halides such as dichlorometane, chloroform, carbon tetrachloride and dichloroethane, etc., and ethers such as dioxane, THF and diethyl ether etc.
Azolation Reaction
The azolylmethyloxabicyclohexane derivative represented by the general formula (VI) can be obtained by reacting the oxabicyclohexanemethanol sulfonic acid ester represented by the general formula (V) with a 1,2,4-triazole or an imidazole, and a base compound in an organic solvent at a reaction temperature in a range of from 0° C. to 100 ° C. for a reaction period in a
range of from 1 hour to 5 hours to substitute a YSO 2 O group with an azole ring.
As the base compound, sodium hydride may be preferably used.
Preferred example Of the Organic solvent used in this reaction step include aromatic hydrocarbons such as benzene, toluene and xylene etc., aliphatic hydrocarbons such as hexane, heptane and isooctane, etc., alkyl halides such as dichloromethane, chloroform, carbon tetrachloride and dichloroethane etc., ethers such as dioxane, THF and diethyl ether, etc., alcohols such as methyl alcohol, ethyl alcohol, etc., and polar aprotic solvents such as acetonitrile, acetone, DMF, DMSO and N-methylpyrrolidone etc.
Reduction Reaction
The cis-azole derivative represented by the general formula (I) can be obtained by reducing the azolylmethyloxabicyclohexane derivatives in an ether using a metal hydride or a combination of metal hydride and Lewis acid at a reaction temperature in a range of from 0° C. to 100° C. for a reaction period in a range of from 0.5 hours to 5 hours.
Examples of the ethers used in this reaction step include diethyl ether, THF and diglym. As the metal hydride, lithium aluminium hydride may be preferably used. An example of the Lewis acid used together with the metal hydride is AlCl 3 .
According to the process of the present invention, cis-azole derivatives represented by the above mentioned general formula (I) which show reliable effects in a smaller amount because of having a higher activity, by which the amount existent in the environment becomes small, can be selectively prepared.
As a result of studies by the present inventors about the use, it has been found that the above-mentioned azolylmethyloxabicyclohexane represented by the general formula (VI) can be used as fungicides in addition to as the intermediate.
In the following, use of the azolylmethyloxabicyclohexane derivative represented by the formula ##STR23## wherein R 1 , R 2 , R, A and n have the same meanings as defined above.
When the azolylmethyloxabicyclohexane derivative represented by the formula (VI) (referred to as "compound of this invention", hereinafter) is used as a fungicidal composition, it is generally used in the form of dust, wettable powder, granules, emulsion and the like together with carriers or other adjuvants. In such a case, the preparations are prepared so as to contain one or more of the compound of this invention in an amount of 0.1%-95% by weight , preferably, 0.5%-90% by weight, and more preferably 2%-70% by weight.
Examples of carriers, diluents and surfactants used as the adjuvants for preparations include the following.
Examples of solid carriers include talc, kaolin, bentonite, diatomaceous earth, white carbon and clay, etc.
Examples of liquid carriers (diluents) include water, xylene, toluene, chlorobenzene, cyclohexane, cyclohexanone, dimethylsulfoxide, dimethylformamide and alcohol, etc.
Examples of the surfactants include polyoxyethylene alkylaryl ether and polyoxyethylene sorbitan monolaurylate etc., as emulsifiers; lignin sulfonates, dibutylnaphthalenesulfonates, etc., as dispersing agents; and alkylsulfonates and alkylphenylsulfonates, etc., as wetting agents.
The above preparations are classified into those which can be used directly, and those which are used after diluting so as to have a suitable concentration with a diluent such as water, etc.
The concentration of the present compounds in case of using after diluting is preferred to be in a range of 0.001%-1.0%.
Further, the application dosage of the compound of this invention is in a range of 20 g-5000 g and preferably 50 g -1000 g per 1 ha of agricultural and horticultural land such as farm, paddy field, fruit garden, hothouse, etc.
It is of course possible to increase and decrease the concentration and the application dosage beyond the above-mentioned ranges, because they depend upon the form of preparations, method of application, place to be used, target crops, etc.
Furthermore, the compound of this invention can be used in combination with other effective ingredients, such as other fungicides, insectcides, miticides, herbicides, etc.
EXAMPLES
Preparation examples, formulation examples and test examples are described in the following, by which the present invention is illustrated in detail.
Preparation examples 6 and 10 and Preparation examples 14, 15, 16, 17 and 18 in the exmples relates to preparation of optically active epoxyalcohol derivatives.
Preparation examples 14-18 disclose the process in which a reagent for asymmetric epoxidation is used together with Molecular Sieves.
Further, the following abbreviations and chemical formulas are used in Preparation examples 6, 10, 14, 15, 16, 17 and 18.
______________________________________(2R,3R)-(+)-diethyl tartarate (+)-DET(2S,3S)-(-)-diethyl tartarate (-)-DETTitanium tetraisopropoxide Ti(O i-Pr).sub.4tert-Butylhydroperoxide TBHP______________________________________
Enantiomer excess ratio (% ee) described in Preparation examples 6, 9, 10, 13, 14, 15, 16, 17 and 18 was determined by high performance liquid chromatography equipped with an optically active column (CHIRALCEL OK, produced by Daicel Co.)
PREPARATION EXAMPLE 1
Cyclopentene methanol derivative [Formula (III): R 1 ═R 2 ═CH 3 , (R) n ═4-Cl]
Preparation of 2-[(4-chlorophenyl)methyl]-5,5-dimethyl-1-cyclopentene-1-methanol:
To 20 g (0.08 mol) of 7-[(4-chlorophenyl)methyl]-4,4-dimethyl-1-oxaspiro[2.4]heptane [Formula(II): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl] was added 150 ml of dioxane, and 5 ml of 10% sulfuric acid was added thereto with stirring under room temperature. The mixture was then stirred at room temperature for 2 hours.
The reaction solution was poured into a saturated aqueous solution of sodium hydrogen carbonate, followed by extracting with ethyl acetate. The resultant organic layer was washed with saturated aqueous saline solution.
After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 17.22 g of a yellowish oily product.
The resultant product was purified by chromatography on a column of silica gel to obtain 13.16 g (0.052 mmol) of 2-[(4-chlorophenyl)methyl]-5,5-dimethyl-1-cyclopentene-1-methanol [Formula (III): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl] as a colorless transparent oily product.
Yield: 65.8%.
Colorless transparent oil
1 H NMR(CDCl 3 ); δ 1.10(s,6H),1.40-1.83(m,2H),1.97-2.33(m,2H),3.43(s,2H), 4.22(s,2H),7.03(d,2H,J=8 Hz),7.23(d,2H,J=8 Hz) IR(neat, νmax); 3350, 2950, 2850, 1490, 1408, 1360, 1090, 1012, 990, 840 cm -1
PREPARATION EXAMPLE 2
Oxabicyclohexanemethanol derivative [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]
Preparation of 5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol:
10.06 g (0.04 mol) of 2-[(4-chlorophenyl)methyl]5,5-dimethyl-1-cyclopentene-1-methanol [Formula (III): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl] were dissolved in 100 ml of chloroform, followed by adding 8.08 g (0.048 mol) of metachloroperbenzoic acid with stirring under cooling with ice.
The mixture was then stirred at room temperature for 1 hour. To the reaction solution was added 7.4 g (0.1 mol) of calcium hydroxide, and the formed precipitate was removed by filtration. The chloroform layer was washed with a saturated aqueous saline solution.
After the chloroform layer was dried with anhydrous sodium sulfate, it was concentrated under reduced pressure to yield 11.86 g of light-yellowish oily product.
The resultant product was purified by chromatography on a column of silica gel to obtain 10.21 g (0.038 mmol) of 5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]
Yield: 95%
White crystal, m.p.: 37°-39° C.
1 H NMR(CDCl 3 ); δ 0.9(s,3H),1.10(s,3H),1.0-1.83(m,4H),2.43(brs,1H,OH), 3.0(s,2H), 3.8(d,1H,J=12 Hz),4.1(d,1H,J=12 Hz),7.13(m,4H)
IR(KBr, νmax); 3400, 2950, 2850, 1482, 1360, 1082, 1010, 836, 780 cm -1
PREPARATION EXAMPLE 3
Oxabicyclohexanemethanol sulfonic acid ester derivative [Formula (V): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl,Y═CH 3 ]
Preparation of 5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol methanesulfonic acid ester:
1.33 g (5 mmol) of 5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol were dissolved in 10 ml of dichloromethane, followed by adding thereto 0.63 g (5.5 mmol) of methanesulfonyl chloride and 0.55 g (5.65 mmol) of triethylamine with stirring under cooling with ice.
The mixture was then stirred under cooling with ice for 1 hour. After conclusion of the reaction was confirmed by TLC, the reaction solution was poured into water and extracted with dichlorometane. The resultant organic layer was washed with aqueous solution of saturated sodium hydrogen carbonate and aqueous saline solution.
After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 1.86 g of a light-yellowish oily product.
The resultant product was purified by chromatography on a column of silica gel to obtain 1.57 g (4.55 mmol) of 5-[(4-chlorophenyl)methyl-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol methanesulfonic acid ester [Formula (V): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, Y═CH 3 ]
Yield: 91%
White crystal, m.p. 78.5°-79.0° C.
1 H NMR (CDCl 3 ); δ 0.98(s,3H),1.10(s,3H),0.83-2.0(m,4H),2.93(s,2H),3.07 (s,3H),4.37(d,1H,J=12 Hz),4.70(d,1H,J=12 Hz),7.07(d,2H,J=8 Hz), 7.25(d,2H,J=8 Hz)
IR(KBr, νmax); 3000, 2940, 2850, 1480, 1350, 1162, 1080, 944, 810 cm -1
PREPARATION EXAMPLE 4
Azolylmethyloxabicyclohexane derivative [Formula(VI): R 1 ═R 2 ═CH 3 , (R) n ═4-Cl, A═N]
Preparation of 5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane (Compound No. VI-1):
To 0.42 g (10.5 mmol) of oily 60% sodium hydride washed with hexane was added 15 ml of dimethylformamide (DMF) and stirred at room temperature. 0.73 g (10.56 mmol) of 1,2,4-triazole were then added thereto. After the mixture was stirred for 30 minutes, 5 ml of a DMF solution containing 3.05 g (8.8 mmol) of 5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol methanesulfonic acid ester [Formula (V): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, Y═CH 3 ]was added dropwise thereto.
Thereafter, the mixture was stirred at room temperature for 4 hours and at 40° C. for 4 hours, and the reaction solution was poured into ice water, followed by extracting with ethyl acetate. The resultant organic layer was washed with 1N-hydrochloric acid, saturated aqueous solution of sodium hydrogen carbonate and saturated aqueous saline solution. After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 2.88 g of a light-yellowish oily product.
The resultant oily product was purified by chromatography on a column of silica gel, followed by crystallizing with hexane to obtain 2.71 g (8.5 mmol) of 5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane as white crystal [Formula (VI): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N].
Yield: 96.6%
White crystal, m.p. 101.5°-102.5° C.
1 H NMR(CDCl 3 ); δ0.73(s,3H),1.0(s,3H), 0.83-2.17(m,4H),2.93(s,2H), 3.07(s,3H),4.33(d,1H,J=16 Hz),4.87(d,1H,J=16 Hz), 7.17(d,2H, J=8 Hz),7.33(d,2H,J=8 Hz),7.93(s,1H),8.33(s,1H)
IR(KBr, νmax); 3100, 2940, 2850, 1480, 1420, 1260, 1200, 1130, 1084, 1020, 950, 840, 720, 660 cm -1
With the same procedure as preparation example 4, except using an imidazole in stead of a 1,2,4-triazole, 5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-imidazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane (Compound No. VI-2) can be prepared.
PREPARATION EXAMPLE 5
Cis-azole derivative [Formula (I): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N]
Preparation of cis-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)cyclopentanol:
To 210 mg (1.57 mmol) of aluminium chloride was added 5 ml of dimethoxyethane (DME) and stirred at room temperature. To the mixture was added 178.7 mg (4.71 mmol) of lithium aluminium hydride and stirred for 30 minutes with elevating the temperature to 50°C. 500 mg (1.57 mmol) of 5-[(4-chlorophenyl)methyl-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane [Formula (VI): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N] was added to the mixture and stirred at 50° C. for 1 hour.
The reaction solution was poured into 50 ml of ice water and extracted with ethyl acetate. The separated organic layer was washed with saturated aqueous saline solution. After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 580 mg of a yellowish oily product.
The resultant oily product was isolated and purified by chromatography on a column of silica gel to obtain 280.3 mg (0.88 mmol) of cis-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)cyclopentanol [Formula (I): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N].
Yield: 55.4%
White crystal, m.p. 113°-114° C.
1 H NMR(CDCl 3 ); δ 0.60(s,3H),1.00(s,3H),1.07-1.90(m,5H),2.33(bs,2H), 3.53(s,1H),4.13(s,2H),7.06(d,2H,J=8 Hz),7.25(d,2H,J=8 Hz), 8.02(s,1H),8.25(s,1H)
IR(KBr, νmax); 3250, 2940, 2850, 1480, 1380, 1262, 1200, 1124, 1080, 1002, 840, 800, 720, 670 cm -1
With the same procedure as preparation example 5, except using the compound (VI-2) instead of the compound (VI-1), cis-5-[(4-chlorophenyl)methyl-2,2-dimethyl-1-(1H-imidazol-1-ylmethyl)cyclopentanol can be prepared.
PREPARATION EXAMPLE 6
Optically active (+)-oxabicyclohexamethanol derivative [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]
Preparation of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol:
1.42 g (5 mmol) of Ti(O i-Pr)were dissolved in 15 ml of dichloromethane and stirred at -20° C. (dry ice/carbon tetrachloride) under a nitrogen stream. To the mixture was added 1.03 g (5 mmol) of (+)-DET and 1.25 g (5 mmol) of 2-[(4-chlorophenyl)methyl]-5,5-dimethyl-1-cyclopentene-1-methanol [Formula (III): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]. After stirred at -20° C. for 5 minutes, 6 ml (10 mmol) of a toluene solution of anhydrous TBHP (1.67 mol/1) was added dropwise thereto. The reaction concluded at -20° C. for 1 hour. After stirred at room temperature for 60 minutes, 6 ml of 30% sodium hydroxide-saturated aqueous solution of sodium chloride were added to the resulted mixture and stirred for further 30 minutes After allowed to stand for a while by adding 1 ml of methanol, the formed organic layer was separated. The aqueous layer was extracted with dichloromethane. The separated organic layers were combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to yield 1.35 g of a light-yellowish oily product.
The resultant oily product was purified by chromatography on a column of silica gel to obtain 1.16 g (4.35 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol [(Formula (I): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl].
Yield: 87%
Colorless transparent oil
[α] D 20 +25.4° (c=1.26, EtOH):91% ee (by HPLC)
1 H NMR(CDCl 3 ); δ 0.9(s,3H),1.10(s,3H),1.0-1.83(m,4H), 2.43(s,1H), 3.0(s,2H), 3.8(d,1H,J=12 Hz), 4.1(d,1H,J=12 Hz), 7.13(m,4H)
IR(neat, ν max); 3400, 2950, 2850, 1482, 1360, 1082, 1010, 836, 780 cm -1
PREPARATION EXAMPLE 7
Optically active (+)-oxabicyclohexanemethanol sulfonic acid ester [Formula(V): R 1 ═R 2 ═CH 3 , (R) n ═4-Cl, Y═CH 3 ]
Preparation of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol methanesulfonic acid ester:
0.84 g (3.15 mmol) of (+)-5-[(4-chlorophenyl) methyl-2,2-dimethyl-6-oxabicyclo [3.1.0]hexane-1-methanol [Formula (IV): R 1 ═R 2 ═CH 3 , (R) n ═4-Cl] were dissolved in 10 ml of dichloromethane, followed by adding 0.41 g (3.5 mmol) of methanesulfonyl chloride and 0.3 g (3.5 mmol) of triethylamine were added thereto with stirring under cooling with ice.
The mixture was then stirred under cooling with ice for 1 hour. After conclusion of the reaction was confirmed by TLC, the reaction solution was poured into water and extracted with dichlorometane. The resultant organic layer was washed with aqueous solution of saturated sodium hydrogen carbonate and aqueous common salt liquor. After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 1.22 g of a light-yellowish oily product.
The resultant oily product was purified by chromatography on a column of silica gel to obtain 1.02 g (2.96 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol methanesulfonic acid ester [Formula (V): R 1 ═R 2 ═CH 3 , (R) n ═4-Cl, Y═CH 3 ]
Yield: 94%
Colorless transparent oil
[α] D 20 +24° (c=1.08, EtOH)
1 H NMR(CDCl 3 ); δ 0.98(s,3H),1.10(s,3H),0.83-2.0 (m,4H),2.93(s,2H),3.07(s,3H),4.37(d,1H,J=12 Hz),4.70(d,1H,J=12 Hz), 7.07(d,2H,J=8 Hz),7.25(d,2H,J=8 Hz)
IR(neat, ν max); 3000, 2940, 2850, 1480, 1350, 1162, 1080, 944, 810 cm -1
PREPARATION EXAMPLE 8
Optically active (-)-azolylmethyloxabicyclohexane derivative [Formula (VI): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N]
Preparation of (-)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-(1H-1,2,4-triazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane (Compound No. VI - 3):
To 0.12 g (3.0 mmol) of oily 60% sodium hydride washed with hexane was added 5 ml of DMF and stirred at room temperature. 0.21 g (3.0 mmol) of 1,2,4-triazole were then added thereto. After the mixture was stirred for 10 minutes, 2 ml of a DMF solution containing 0.86 g (2.5 mmol) of (-)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol methanesulfonic acid ester [Formula (V): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, Y═CH 3 ] was added dropwise thereto.
Thereafter, the mixture was stirred at room temperature for 1 hour and at 40° C. for 4 hours, and the reaction solution was poured into ice water, followed by extracting with ethyl acetate. The resultant organic layer was washed with 1N-hydrochloric acid, saturated aqueous solution of sodium hydrogen carbonate and saturated aqueous salinel solution. After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 0.82 g of a light-yellowish oily product.
The resultant oily product was purified by chromatography on a column of silica gel, followed by crystallizing with hexane to obtain 0.77 g (2.42 mmol) of (-)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane as white crystal [Formula (VI): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N].
Yield: 96.8%
[α] D 20 -11° (c=1.0, EtOH)
White crystal, m.p. 97°-99° C.
1 H NMR(CDCl 3 ), δ 0.73(s,3H),1.0(s,3H),0.83-2.17 (m,4H),2.93(s,2H),3.07(s,3H),4.33(d,1H,J=16 Hz),4.87(d,1H,J=16 Hz), 7.17(d,2H,J=8 Hz),7.33(d,2H,J=8 Hz),7.93(s,1H), 8.33(s,1H)
IR(KBr, ν max); 3100, 2940, 2850, 1480, 1420, 1260, 1200, 1130, 1084, 1020, 950, 840, 720, 660 cm -1
With the same procedure as preparation example 8, except using an imidazole in stead of a 1,2,4-triazole, (-)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-(1H-imidazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane (Compound No. VI - 4) can be prepared.
PREPARATION EXAMPLE 9
Optically active cis-azole derivative [Formula (I): R 1 ═R 2 ═CH 3 , (R) n ═4-Cl, A═N]
Preparation of (-)-cis-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H,-1,2,4-triazol-1-ylmethyl)cyclopentanol:
To 212.4 mg (1.59 mmol) of aluminium chloride was added 5 ml of dimethoxyethane (DME) and stirred at room temperature. To the mixtutre was added 181.6 mg (4.78 mmol) of lithium aluminium hydride and stirred for 30 minutes with elevating the temperature to 50° C. 503.7 mg(1.58 mmol) of (-)-5-[(4-chlorophenyl)methyl]-2,2- dimethyl-1-(1H,1,2,4-triazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane, [Formula (VI): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N] were added to the mixture and stirred at 50° C. for 1 hour.
The reaction solution was poured into 50 ml of ice water and extracted with ethyl acetate. The separated organic layer was washed with saturated aqueous saline solution. After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 550 mg of a yellowish oily product.
The resultant oily product was isolated and purified by chromatography on a column of silica gel to obtain 267.4 mg (0.836 mmol) of (-)-cis-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)cyclopentanol [Formula (I): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N].
Yield: 52.9%
White crystal, m.p. 137°-138° C. (recrystallization from n-hexane/ethyl acetate=10/1)
[α] D 20 -23.7° (c=10.0, EtOH), 99% ee (by HPLC)
1 H NMR(CDCl 3 ); δ 0.60(s,3H),1.00(s,3H),1.07-1.90(m,5H),2.33(bs,2H),3.53 (s,1H),4.13(s,2H),7.06(d,2H,J=8 Hz),7.25(d,2H,J=8 Hz),8.02 (s,1H),8.25(s,1H)
IR(KBr, ν max); 3250, 2940, 2850, 1480, 1380, 1262, 1200, 1124, 1080, 1002, 840, 800, 720, 670 cm -1
With the same procedure as preparation example 9, except using the compound (VI - 4) instead of the compound (VI - 3), (-)-cis-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-imidazol-1-ylmethyl)cyclopentanol can be prepared.
PREPARATION EXAMPLE 10
Optically active (-)-oxabicyclohexamethanol derivative [Formula (IV):R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]
Preparation of (-)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol:
1.42 g (5 mmol) of Ti(O i-Pr)were dissolved in 15 ml of dichloromethane and stirred at -20° (dry ice/carbon tetrachloride) under a nitrogen stream. To the mixture was added 1.03 g (5 mmol) of (-)-DET and 1.25 g (5 mmol) of 2-[(4-chlorophenyl)methyl]-5,5-dimethyl-1-cyclopentene-1-methanol [Formula (III): R 1 ═R 2 ═CH 3 ,(R) n ═4-CL]. After stirred at -20° C. for 5 minutes, 6 ml (10 mmol) of a toluene solution of anhydrous TBHP (1.67 mol/1) was added dropwise thereto. The reaction concluded at -20° C. for 1 hour. After stirred at room temperature for 60 minutes, 6 ml of 30% sodium hydroxide-saturated aqueous solution of common salt were added to the resulted mixture and stirred for further 30 minutes. After allowed to stand for a while by adding 1 ml of methanol, the formed organic layer was separated. The aqueous layer was extracted with dichloromethane. The separated organic layers were combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to yield 1.40 g of a light-yellowish oily product.
The resultant oily product was purified by chromatography on a column of silica gel to obtain 1.16 g (4.35 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol [Formula (I): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl].
Yield: 81%
Colorless transparent oil
[α] D 20 -25.0° (c=1.64, EtOH),:98.8% ee (by HPLC) 1 H NMR (CDCl 3 ); δ 0.9(s,3H),1.10(s,3H),1.0-1.83(m,4H), 2.43(s,1H), 3.0(s,2H), 3.8(d,1H,J=12 Hz), 4.1(d,1H,J=12 Hz), 7.13(m,4H)
IR(neat, ν max); 3400, 2950, 2850, 1482, 1360, 1082, 1010, 836, 780 cm -1
PREPARATION EXAMPLE 11
Optically active (-)-oxabicyclohexanemethanol sulfonic acid ester [Formula (V): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, Y═CH 3 ]
Preparation of (-)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol methanesulfonic acid ester: 0.93 g (3.48 mmol) of (-)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl] were dissolved in 10 ml of dichloromethane, followed by adding 0.44 g (3.8 mmol) of methanesulfonyl chloride and 0.38 g (3.8 mmol) of triethylamine were added thereto with stirring under cooling with ice.
The mixture was then stirred under cooling with ice for 1 hour. After conclusion of the reaction was confirmed by TLC, the reaction solution was poured into water and extracted with dichlorometane. The resultant organic layer was washed with aqueous solution of saturated sodium hydrogen carbonate and aqueous common salt liquor. After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 1.27 g of a light-yellowish oily product.
The resultant oily product was purified by chromatography on a column of silica gel to obtain 1.14 g (3.3 mmol) of (-)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol methanesulfonic acid ester [Formula (V): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, Y═CH 3 ]
Yield: 95%
Colorless transparent oil
[α] D 20 -24.5° (c=1.2, EtOH)
1 H NMR(CDCl 3 ); δ 0.98(s,3H),1.10(s,3H),0.83-2.0(m,4H),2.93(s,2H),3.07 (s,3H),4.37(d,1H,J=12 Hz),4.70(d,1H,J=12 Hz),7.07(d,2H, J=8 Hz),7.25(d,2H,J=8 Hz)
IR(neat,ν max); 3000, 2940, 2850, 1480, 1350, 1162, 1080, 944, 810 cm -1
PREPARATION EXAMPLE 12
Optically active (+)-azolylmethyloxabicyclohexane derivative [Formula (VI): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N]
Preparation of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-(1H-1,2,4-triazol-1-ylmethyl)-6-oxabicyclo-[3.1.0]hexane (Compound No. VI - 5):
To 0.14 g (3.5 mmol) of oily 60% sodium hydride washed with hexane was added 5 ml of dimethylformamide (DMF) and stirred at room temperature. 0.25 g (3.6 mmol) of 1,2,4-triazole were then added thereto. After the mixture was stirred for 10 minutes, 2 ml of a DMF solution containing 1.03 g (3.0 mmol) of (-)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]-hexane-1-methanol methanesulfonic acid ester [Formula (V): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, Y═CH 3 ] was added dropwise thereto.
Thereafter, the mixture was stirred at room temperature for 1 hour and at 40 ° C. for 4 hours, and the reaction solution was poured into ice water, followed by extracting with ethyl acetate. The resultant organic layer was washed with 1N-hydrochloric acid, saturated aqueous solution of sodium hydrogen carbonate and saturated aqueous saline solution. After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 1.05 g of a light-yellowish oily product.
The resultant oily product was purified by chromatography on a column of silica gel, followed by crystallizing with hexane to obtain 0.89 g (2.8 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane as white crystal [Formula (VI): R 1 ═R 2 ═CH 3 ,(R) n =4-Cl, A═N].
Yield: 93.3%
[α] D 20 +12° (c=1.0, EtOH)
White crystal, m.p. 97°-99° C.
1 H NMR(CDCl 3 ); δ 0.73(s,3H),1.0(s,3H),0.83-2.17(m,4H),2.93(s,2H),3.07 (s,3H),4.33(d,1H,J=16 Hz),4.87(d,1H,J=16 Hz),7.17(d,2H, J=8 Hz),7.33(d,2H,J=8 Hz),7.93(s,1H),8.33(s,1H)
IR(KBr, ν max); 3100, 2940, 2850, 1480, 1420, 1260, 1200, 1130, 1084, 1020, 950, 840, 720, 660 cm -1
With the same procedure as preparation example 12, except using an imidazole in stead of a 1,2,4-triazole, triazole, (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl- (1H-imidazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane (Compound No. VI - 6) can be prepared.
PREPARATION EXAMPLE 13
Optically active cis-azole derivative [Formula (I):R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N]
Preparation of (+)-cis-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)cyclopentanol
To 0.27 g (2.0 mmol) of aluminium chloride was added 5 ml of dimethoxyethane (DME) and stirred at room temperature. To the mixtutre was added 0.23 g (6.1 mmol) of lithium aluminium hydride and stirred for 30 minutes with elevating the temperature to 50° C. 0.64 g (2.0 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)-6-oxabicyclo[3.1.0]hexane [Formula (VI): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N] were added to the mixture and stirred at 50° C. for 1 hour.
The reaction solution was poured into 50 ml of ice water and extracted with ethyl acetate. The separated organic layer was washed with saturated aqueous saline solution. After dried with anhydrous sodium sulfate, the organic layer was concentrated under reduced pressure to yield 0.72 g of a yellowish oily product.
The resultant oily product was isolated and purified by chromatography on a column of silica gel to obtain 0.36 g (1.13 mmol) of (+)-cis-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1ylmethyl)cyclopentanol [Formula (I): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl, A═N].
Yield: 56.5%
White crystal, m.p. 137°-138° C. (recrystallization from n-hexane/ethyl acetate=10/1)
[α] D 20 +23.7° (c=10.0, EtOH):99% ee (by HPLC)
1 H NMR(CDCl 3 ); δ 0.60(s,3H),1.00(s,3H), 1.07-1.90(m,5H),2.33(bs,2H), 3.53(s,1H),4.13(s,2H),7.06(d,2H,J=8 Hz),7.25(d,2H,J=8 Hz), 8.02(s,1H),8.25(s,1H)
IR(KBr, ν max); 3250, 2940, 2850, 1480, 1380, 1262, 1200, 1124, 1080, 1002, 840, 800, 720, 670 cm -1
With the same procedure as preparation example 13, except using the compound (VI - 6) instead of the compound (VI - 5), (+)-cis-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-imidazol-1-ylmethyl)cyclopentanol can be prepared.
PREPARATION EXAMPLE 14
Optically active (+)-oxabicyclohexanemethanol derivative [Formula(IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]
Preparation of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane methanol:
15 ml of dichloromethane were placed in a 3-neck flask (50 ml) and stirred at -40° C. (dry ice/acetone) under a nitrogen stream. After 200 mg of Molecular Sieve 4A (powdered, activated molecular sieves; Aldrich Co.) with stirring, 28.4 mg (0.1 mmol; 5 mol %) of Ti(O i-Pr) 4 , 31 mg (0.15 mmol; 7.5 mol %) of (+)-DET and 500 mg (2.0 mmol) of 2-[(4-chlorophenyl)methyl]-5,5-dimethyl-1-cyclopentene-1-methanol [Formula (III): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl] were added thereto and the resultant mixture was stirred at -40° C. for 10 minutes. Thereafter 2.4 ml (4.0 mmol) of a toluene solution of anhydrous TBHP (1.67 mol/1) were added dropwise so as not to elevate the temperature to -40° C.
After allowed to react at -40° C. for 5 hours, 20 ml of water were added thereto, followed by stirring for 30 minutes. Thereafter, 5 ml of 30% sodium hydroxide saturated aqueous common salt liquor were added to the mixture, followed by stirring further 30 minutes. After allowed to stand for a while by adding 1 ml of methanol, the formed organic layer was separated. The aqueous layer was extracted with dichloromethane. The separated organic layers were combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to yield 0.63 g of a colorless transparent oily product.
The resultant product was purified by chromatography on a column of silica gel to obtain 0.46 g (1.7 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl].
Yield: 81%
Colorless transparent oil
[α] D 20 +18° (c=1.5, EtOH):64% ee (by HPLC)
1 H NMR (CDCl 3 ); δ 0.9(s,3H),1.10(s,3H),1.0˜1.83(m,4H), 2.43(s,1H), 3.0(s,2H), 3.8(d,1H,J=12 Hz), 4.1(d,1H,J=12 Hz),7.13(m,4H)
IR(neat, ν max); 3400, 2950, 2850, 1482, 1360, 1082, 1010, 836, 780 cm -1
PREPARATION EXAMPLE 15
Optically active (+)-oxabicyclohexanemethanol derivative [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]
Preparation of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol:
5 ml of dichloromethane were placed in a 3-neck flask (50 ml) and stirred at -40° C. (dry ice/acetonitril) under a nitrogen stream. After 200 mg of Molecular Sieve 4A (powdered, activated molecular sieves; Aldrich Co.) with stirring, 28.4 mg (0.1 mmol; 10 mol %) of Ti(O i-Pr ) 4 , 32 mg (0.15 mmol; 15 mol %) of (+)-DET and 250 mg (1.0 mmol) of 2-[(4-chlorophenyl)methyl]-5,5-dimethyl-1-cyclopentene-1-methanol [Formula (III): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl] were added thereto and the resultant mixture was stirred at -40° C. for 10 minutes. Thereafter 1.2 ml (2.0 mmol) of a toluene solution of anhydrous TBHP (1.67 mol/1) were added dropwise so as not to elevate the temperature to -40° C.
After allowed to react at -40° C. for 5 hours, 20 ml of water were added thereto, followed by stirring for 30 minutes. Thereafter, 5 ml of 30% sodium hydroxide-saturated aqueous saline solution were added to the mixture, followed by stirring further 30 minutes. After allowed to stand for a while with adding 1 ml of methanol, the formed organic layer was separated. The aqueous layer was extracted with dichloromethane. The separated organic layers were combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to yield 0.28 g of a colorless transparent oily product.
The resultant product was purified by chromatography on a column of silica gel to obtain 0.22 g (1.7 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl].
Yield: 82%
Colorless transparent oil
[α] D 20 +23.2° (c=1.5, EtOH):80% ee (by HPLC)
PREPARATION EXAMPLE 16
Optically active (+)-oxabicyclohexanemethanol derivative [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]
Preparation of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol:
5 ml of dichloromethane were placed in a 3-neck flask (50 ml) and stirred at -20° C. (dry ice/carbon tetrachloride) under a nitrogen stream. After 200 mg of Molecular Sieve 4A (powdered, activated molecular sieves; Aldrich Co.) with stirring, 28.4 mg (0.1 mmol; 10 mol %) of Ti(O i-Pr) 4 , 33.7 mg (0.16 mmol;16 mol %) of (+)-DET and 250 mg (1.0 mmol) of 2-[(4-chlorophenyl)-methyl]-5,5-dimethyl-1-cyclopentene-1-methanol [Formula (III): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl] were added thereto and the resultant mixture Was stirred at -20° C. for 10 minutes. Thereafter 1.2 ml (2.0 mmol) of a toluene solution of anhydrous TBHP (1.67 mol/1) were added dropwise so as not to elevate the temperature to -20° C.
After allowed to react at -20° C. for 2 hours, 20 ml of water were added thereto, followed by stirring for 30 minutes. Thereafter, 5 ml of 30% sodium hydroxide-saturated aqueous saline solution were added to the mixture, followed by stirring further 30 minutes. After allowed to stand for a while with adding 1 ml of methanol, the formed organic layer was separated. The aqueous layer was extracted with dichloromethane. The separated organic layers were combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to yield 0.32 g of a colorless transparent oily product.
The resultant product was purified by chromatography on a column of silica gel to obtain 206.4 mg (0.77 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl].
Yield: 77%
Colorless transparent oil
[α] D 20 +12.6° (c=1.2, EtOH): 48% ee (by HPLC)
PREPARATION EXAMPLE 17
Optically active (+)-oxabicyclohexanemethanol derivative [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]
Preparation of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol:
5 ml of dichloromethane were placed in a 3-neck flask (50 ml) and stirred at 0° C. under a nitrogen stream. After 200 mg of Molecular Sieve 4A (powdered, activated molecular sieves; Aldrich Co.) with stirring, 28.4 mg (0.1 mmol;10 mol %) of Ti(O i-Pr) 4 , 32 mg (0.15 mmol;15mol %) of (+)-DET and 250 mg (1.0 mmol) of 2-[(4-chlorophenyl)methyl]-5,5-dimethyl-1-cyclopentene-1-methanol [Formula (III): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl] were added thereto and the resultant mixture was stirred at 0° C. for 10 minutes. Thereafter 1.2 ml (2.0 mmol) of a toluene solution of anhydrous TBHP (1.67mol/1) were added dropwise so as not to elevate the temperature to 0° C.
The reaction was completed in 30 minutes. After 20 ml of water were added and stirred at room temperature for 30 minutes, 5 ml of 30% sodium hydroxide-saturated aqueous saline solution were added to the mixture, followed by stirring further 30 minutes. After allowed to stand for a while with adding 1 ml of methanol, the resulted organic layer was separated. The aqueous layer was extracted with dichloromethane. The separated organic layers were combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to yield 0.28 g of a colorless transparent oily product.
The resultant product was purified by chromatography on a column of silica gel to obtain 196.4 mg (0.74 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl].
Yield: 74%
Colorless transparent oil
[α] D 20 +7° (c=1.5, EtOH): 20% ee (by HPLC)
PREPARATION EXAMPLE 18
Optically active (+)-oxabicyclohexanemethanol derivative [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl]
Preparation of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol:
5 ml of dichloromethane were placed in a 3-neck flask (50 ml) and stirred at -40° C. (dry ice/acetonitril) under a nitrogen stream. After 200 mg of Molecular Sieve 4A (powdered, activated molecular sieves; Aldrich Co.) with stirring, 29.8 mg (0.105 mmol;7 mol %) of Ti(O i-Pr ) 4 , 33 mg (0.15 mmol; 10 mol %) of (+)-DET and 376 mg (1.5 mmol) of 2-[(4-chlorophenyl)methyl]-5,5-dimethyl-1-cyclopentene-1-methanol [Formula (III): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl] were added thereto and the resultant mixture was stirred at -40° C. for 10 minutes. Thereafter 1.2 ml (2.0 mmol) of a toluene solution of anhydrous TBHP (1.67 mol/1) were added dropwise so as not to elevate the temperature to -40° C.
After allowed to react at -40° for 5 hours, 20 ml of water were added thereto, followed by stirring for 30 minutes. Thereafter, 5 ml of 30% sodium hydroxide-saturated aqueous saline solution were added to the mixture, followed by stirring further 30 minutes. After allowed to stand for a while with adding 1 ml of methanol, the resulted organic layer was separated. The aqueous layer was extracted with dichloromethane. The separated organic layers were combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to yield 0.45 g of a colorless transparent oily product.
The resultant product was purified by chromatography on a column of silica gel to obtain 330.6 mg (1.24 mmol) of (+)-5-[(4-chlorophenyl)methyl]-2,2-dimethyl-6-oxabicyclo[3.1.0]hexane-1-methanol [Formula (IV): R 1 ═R 2 ═CH 3 ,(R) n ═4-Cl].
Yield: 82.7%
Colorless transparent oil
[α] D 20 +23.5° (c=1.5, EtOH):72% ee (by HPLC)
FORMULATION EXAMPLE 1
Dust
______________________________________ Parts by weight______________________________________Compound (VI) 3Clay 40Talc 57______________________________________
The above-mentioned ingredients were mixed to prepare a dust.
FORMULATION EXAMPLE 2
Wettable Powder
______________________________________ Parts by weight______________________________________Compound (VI) 50Ligninsulfonate 5Alkylsulfonate 3Diatomaceous earth 42______________________________________
The above-mentioned ingredients were mixed to prepare a wettable powder.
FORMULATION EXAMPLE 3
Granule
______________________________________ Part by weight______________________________________Compound (VI) 5Bentonite 43Clay 45Ligninsulfonate 7______________________________________
The above-mentioned ingredients were mixed and kneaded with adding water thereto. The mixture was gnalurated by means of an extrusion granulating machine, followed by drying to obtain granules.
FORMULATION EXAMPLE 4
Emulsion
______________________________________ Parts by weight______________________________________Compound (VI) 20Polyoxyethylene alkyl aryl ether 10Polyoxyethylnene sorbitan monolaurate 3Xylene 67______________________________________
The above mentioned ingredients were mixed and dissolved to obtain an emulsion.
TEST EXAMPLE
Antimicrobial test against various microorganisms:
This example shows results of the following antimicrobial test of optically active (-)-azolylmethyloxabicyclohexane derivative (formula (VI): R 1 ═R 2 ═CH 3 , (R) n ═4-Cl, A═N) prepared in Preparation Example 8 against various kinds of plant disease microorganisms.
Method
The compound of this invention was dissolved in dimethylsulfoxide in a suitable concentration. 0.6 ml of the solution was well mixed with 60 ml of a PAS culture medium at about 60° C. in a 100 ml conical flask, and the resultant mixture was poured into Petri dishes and was caused to coagulate, by which plate culture media containing the compound of this invention were obtained.
On the other hand, plate culture media on which test microorganisms were previously cultured were punched by a cork borer so as to have a diameter of 4 mm, followed by inoculating on the above-mentioned plate culture medium. After inoculation was carried out, they were incubated for 1-3 days at a preferable temperature for each microorganism, and growth of microorganisms was obserbed by measuring the diameter of the colony. Hyphae elongation inhibitory rates were determined respectively in accordance with the below-described equation.
R=100 (dc-dt)/dc
wherein
R=Hyphae elongation inhibitory rate (%)
dc=Diameter of colony on the non-treated plate culture medium
dt=Diameter of colony on the plate culture medium containing the tested compound
Test results were ranked in five stages by the following ranking system. The results are shown in Table 1.
5 . . . at least 90%-100%
4 . . . at least 70% but lower than 90%
3 . . . at least 40% but lower than 70%
2 . . . at least 20% but lower than 40%
1 . . . lower than 20%
TABLE 1______________________________________ Biocidal activity (concentration:Test fungus 100 μg/ml)______________________________________Pyricularia oryzae 5Cochliobolus miyabeanus 5Gibberella fujikuroi 5Helminthosporium sigmoideum 5Rhizoctonia solani 3Botrytis cinerea 5Sclerotinia sclerotiorum 5Fusarium oxysporum f.sp. niveum 5Fusarium oxysporum f.sp. 5cucumerinumFusarium oxysporum f.sp. raphani 5Colletotrichum lagenarium 4Cercospola beticola 5Cercospore kikuchii 4Monilinia fructicola 5Alternaria kikuchiana 4Alternaria mali 5Glomerella cingulata 5______________________________________ | Disclosed herein is a process for preparing a cis-azole derivative represented by the general formula (I) ##STR1## wherein R 1 and R 2 denote each a hydrogen atom or an alkyl group, R denotes a halogen atom, a nitro group, a cyano group, an alkyl group, a haloalkyl group or a phenyl group, A denotes a nitrogen atom or a methine group, and n stands for an integer of 1-5,
which comprises reducing an azolylmethyloxabicyclohexane derivative represented by the general formula (VI) ##STR2## wherein R 1 , R 2 , R, A and n have the same meanings as defined above. A fungicidal composition comprising the azolylmethyloxabicyclohexane derivative represented by the above-mentioned general formula (VI) is also desclosed. | 2 |
FIELD OF THE INVENTION
This invention relates to a system and method for rotating and handling heavy objects. In particular, the present invention relates to an automated system and method for rotating and handling a metal slab requiring surface conditioning such as scarfing.
BACKGROUND OF THE INVENTION
Conditioning the surface of metal in a semi-finished state before additional processing is a necessary and common procedure to preserve the integrity of finished metal products. If not cured, surface defects present in the metal in its semi-finished state can cause severe defects in the processed metal, as well as fouling the processing equipment. Several different surface conditioning techniques are used to cure surface defects present in steel and other metals after processing. Examples of these techniques include grinding, hand chipping, and scarfing.
The most common method of removing surface defects from steel slabs, billets, and blooms is scarfing. Scarfing steel slabs is a process of applying oxygen and gas, usually by a torch, to the surface of the steel slab to oxidize and melt the surface steel. The oxidized material and molten steel, including and adjacent the surface defect, is then blown away from the slab.
Many different methods of manual and machine scarfing are provided in the prior art, each with varying degrees of efficiency. One common requirement of each method is easy access to each surface of the metal to be scarfed. Thus, a metal slab with one surface resting on a platform or rail cart must eventually be turned over or rotated during the scarfing process to expose such surface to the scarfing equipment.
Rotating and handling metal slabs weighing up to 40 tons presents serious practical and safety concerns. One method and system for conditioning metal slabs disclosed in the prior art provides two independently rotatable leaves for rotating a slab in a stationary carrier in a scarfing station. This method and system, however, only provide scarfing access to the bottom and top surfaces of the slab and neglect the outside edges of the slab. This system also fails to provide, inter alia, a movable cart thereby requiring the scarfing equipment to move relative to the rotatable leaves. While other machines are provided in the prior art for handling various heavy objects, none are adapted for use with steel slabs or provide the increased efficiency and safety of the present invention.
SUMMARY OF THE INVENTION
The present invention provides a system and method for rotating and handling a metal slab requiring surface conditioning such as scarfing. The system comprises a carrier in the form of a transfer cart, and a slab turner, each designed to cooperate with the other, to rotate and linearly displace a slab by tilting and passing the slab in a series of coordinated steps between the carrier and the slab turner. The invention provides one step for transferring the slab while horizontal and another step for transferring the slab while non-horizontal.
The slab turner comprises a turner bunk pivotally mounted to a multiple-linkage support structure and designed to receive a flat slab. The support structure is integrally linked with several fluid actuated rams for rotating the turner bunk about several independent axes of rotation, as well as linearly displacing the turner bunk perpendicular to the several axes of rotation towards and away from the transfer cart.
The transfer cart comprises a cart bunk pivotally mounted to a movable rail cart and designed to receive a flat slab from the slab turner. The cart bunk is linked to a transfer cart support structure by fluid actuated rams which rotate the cart bunk about an axis of rotation parallel to the axes of rotation of the slab turner.
The rotational paths of the slab turner and transfer cart overlap allowing the turner and cart to exchange the slab. The rotational paths do not, however, interfere with each other, allowing independent movement and rotation of the respective bunks of the transfer cart and the slab turner.
In one of the prior art arrangements, an overhead lifting device is used twice during the scarfing process. The lifting device is first used to load and unload a slab directly on a transfer cart for movement to a scarfing area. The lifting device is also used in between loading and unloading to rotate the slab.
In the present invention, the slab is delivered initially to a reinforced support structure thereby reducing impact loading and wear on the transfer cart or slab turner. The slab is rotated by the slab turner and transfer cart and not an by overhead lifting device. Demand, maintenance, and repair are therefore reduced on the overhead lifting device as well. Personnel involvement in the overall scarfing process is also reduced as the process becomes more automated according to the present invention. Safety is improved since handlings by the overhead lifting device are cut in half. Safety is also improved since the slab turner positively lifts the slab from underneath as opposed to lifting the slab from its top surface by a series of magnets.
The system embodied in the present invention may have numerous applications in areas other than handling of heavy metal slabs for scarfing. The system and method has application where handling of large, heavy products is critical, and where roller tables or transfer cars are involved.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred structure and example of the invention are more fully set forth hereinafter with reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view of a slab turner handling a slab (shown in phantom) according to the present invention;
FIG. 2 is a perspective view of a transfer cart handling a slab (shown in phantom) according to the present invention;
FIG. 3 is a front elevational view of a transfer cart with the overlapping path of the slab turner shown in relation to the cart;
FIG. 4 is a side plan view of the slab positioning system showing the transfer cart and slab turner in their parked positions;
FIGS. 5-10 are side views of the slab positioning system showing the sequence of movements to position the slab on the cart with surfaces exposed for scarfing;
FIGS. 11-15 are views of the system showing rotation of the slab to expose opposite surfaces for scarfing.
FIG. 16 is a schematic diagram of the sensing device and control components for the fluid actuated rams of the slab turner and transfer cart.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in greater detail to the drawings, the invention provides a system for rotating and handling a heavy metal slab requiring surface conditioning. The system is particularly adapted for use with a metal slabrequiring scarfing on each of the slab's outside surfaces, including the outside edges.
The system comprises two major components, a slab turner and a carrier, which are designed to closely interact to perform the required rotating procedure. The carrier is preferably in the form of a transfer cart which carries the slab into a scarfing station. The system rotates the slab, exposing each outside surface and edge to the scarfing equipment. The slabis turned through a series of coordinated steps in which the slab is tilted, rotated, and passed back and forth between the slab turner and transfer cart twice in the turning cycle.
The slab turner comprises a turner bunk 20 pivotally mounted to a support structure capable of rotating and linearly displacing the turner bunk intoand out of close proximity with the transfer cart. As seen in FIG. 1, the support structure is pivotally fixed to a support base 15. The support structure comprises several support members pivotally mounted to each other at their respective ends. Each support member is also linked to and controlled by an independent fluid actuated ram. The fluid actuated rams are operable between extended and retracted positions for rotating the support members about independent axes of rotation relative to each other.
The support structure comprises a set of identical pivotal linkages. The linkages are spaced apart as much as four meters or more, depending on thelength of the transfer cart and the length of the slab to be handled. The weight of the slab is equally balanced on each linkage. Several support members of the oppositely disposed linkages are connected by cross pieces,such as axles and sleeves or torque tubes, to insure synchronous movement of the corresponding support members in each linkage of the structure.
Describing the elements of a linkage from the base 15 up to the bunk 20, a first support member 32 is mounted at its proximal end 32a to a first axlepiece 18 which rotates in a hinge housing or journal 16 mounted on the support base 15 as seen in FIG. 1. Spherical brass bushings or roller bearings are provided for smooth rotation of the first piece 18 and other connecting axle pieces, 17, 19, and 22. The first support member 32 has anaperture through its proximal end the same size and shape as the first piece 18 to which it is fixed. The first support member 32 does not rotatewith respect to the first piece 18. Rather, the cross piece 18 rotates in the hinge housing 16.
The dimensions of the first support member 32 and the other support memberson the turner (described hereinafter), are interdependent, as well as dependent on the dimensions of the transfer cart, metal slab, and scarfingfacilities. The support members may be either straight or angled, as seen in FIG. 1, to obtain the desired path of motion. Several alternate combinations of support member dimensions may create the desired path of motion of the slab turner.
A primary fluid actuated ram 30 is fixed at its cylinder end to a connecting piece 17 which is pivotally mounted to on the support base 15 distantly from the hinge 16. The primary fluid actuated ram 30 does not rotate with respect to the connecting piece 17. Rather, the connecting piece 17 rotates on the support base. The ram end of the primary fluid actuated ram is pivotally fixed to the first support member 32 at a medialposition 32c on the first support member 32. The primary fluid actuated ram30 extends and retracts causing the first support member 32 to rotate abouta first axis of rotation, i.e., the axis of the connecting piece 18, relative to the support base.
The first support member 32 and the primary fluid actuated ram are linked to a corresponding parallel first support member 132 and primary fluid actuated ram 130 on the second linkage by connecting pieces 18 and 17, respectively. Rotation of either first support member, 32 or 132, or of either primary fluid actuated ram, 30 or 132, will cause the other supportmember or fluid actuated ram to rotate the same distance, respectively.
A second support member 36 is pivotally mounted at its proximal end 36a to the second connecting piece 19 which rotates in an aperture located in thedistal end 32b of the first support member. The second support member has an aperture through its proximal end 32a the same size and shape as the second connecting piece 19 to which it is fixed. The second support member36 does not rotate with respect to the second connecting piece 19. Rather, the connecting piece 19 rotates with respect to the first support member 32.
The second support member 36 is linked to a parallel corresponding second support member 136 on the second linkage by the connecting piece 19. The parallel second support member 136 is a)so fixed to the connecting piece 19 such that rotation of either support member, 36 or 136, will cause the other support member to rotate the same distance.
A secondary fluid actuated ram 38 is preferably pivotally mounted at its cylinder end at a medial position 32d on the first support member. As seenin FIG. 1, an extensions of the first support member 34 is fixed to the first connecting piece 18. The cylinder end of the secondary fluid actuated ram 38 is pivotally mounted to the extension 34. The ram end of the secondary fluid actuated ram 38 is pivotally fixed to a medial position 36c on the second support member 36. The secondary fluid actuatedram extends and retracts causing the second support member to rotate about a second axis of rotation relative to the first support member 32. The second axis of rotation, connecting piece 19, is parallel to the first axis of rotation, i.e., the axis of the connecting piece 18.
A turner bunk 20 is pivotally mounted at a medial position 20a to the distal end 36b of the second support member 38. The turner bunk 20 and second support member 36 each have an aperture to receive a common pivot pin 22 linking the bunk and support member.
A tertiary fluid actuated ram 42 is pivotally mounted at its cylinder end at a medial position 36d on the second support member 36. The shaft end ofthe tertiary fluid actuated ram is pivotally fixed to a medial position 20bon the turner bunk located distantly from the pivot pin 22. The tertiary fluid actuated ram 42 extends and retracts causing the turner bunk to rotate about a turner bunk axis of rotation, pivot pin 22, relative to thesecond support member 36. The turner bunk axis of rotation, i.e., the axis of the pivot pin 22, is parallel to the first and second axes of rotation.
A second corresponding parallel turner bunk 120 is pivotally mounted on a parallel second support member 136. The two turner bunks define a flat turner bunk plane on which a metal slab 10 (shown in phantom) will be received in a substantially horizontal position relative to the structure base 15. A toe cap mechanism 20c perpendicular to the turner bunk plane ismounted to each turner bunk to prevent the slab 10 from sliding off the turner bunk plane as the turner bunk rotates the slab towards a substantially vertical or other non-horizontal position.
Cooperating with each other, the fluid actuated rams act on the support members via a programmable logic controller, shown schematically in FIG. 16, to rotate and move the turner bunk linearly towards and away from the transfer cart. The path of the turner bunk can be changed by reprogrammingthe programmable logic controller to accommodate metal slabs, transfer carts, and scarfing facilities of varying dimensions. For example the turner can handle slabs with widths varying from two feet to seven feet. As seen in FIG. 3, the path of the slab turner is shown in phantom relative to the transfer cart.
Each linkage preferably has a separate pump providing hydraulic pressure tothe fluid actuated rams. To insure synchronous movement of each paired support members on the linkages, each pump contains an adjustable flow restricter and a pressure balance. The flow restricter insures equal flow of hydraulic fluid to corresponding cylinders of each linkage. The pressure balance insures equal pressure in each cylinder in the event a slab is loaded off center and weighs more heavily on one linkage than the other.
Referring to FIG. 2, the transfer cart comprises a movable cart base 50 supported by two axles 52 and rail wheels 54 for movement along rail tracks 56. A cart bunk 60 is fixed to a connecting axle piece 64 pivotallymounted to a cart bunk support structure 70 fixed to the transfer cart 50. The support structure comprises two identical rigid support members 70 and170 spaced along the length of the cart.
The dimensions of the rigid support members 70 and 170 are dependent on thedimensions of the slab turner, metal slab, and scarfing facilities. As seenin FIG. 3, the distance between the outside surfaces of the cart support members, however, must be less than the distance between the inside surfaces of the turner support structures and turner bunks so that the bunks of the transfer cart and slab turner can overlap or interdigitate without interference. The rigid support members are spaced approximately four meters or less from each other.
The cart bunk 60 is fixed at a medial position 60a to a connecting piece 64pivotally mounted to the support structure 60. The cart bunk does not rotate relative to the connecting piece 64. Rather, the connecting piece 64 rotates in and relative to the support structure 70. The cart bunk axisof rotation, i.e., the axis of the connecting piece 64, is parallel to the first, second, and turner bunk axes of rotation.
The second cart bunk 160 is linked to the first cart bunk 60 by the connecting piece 64, which is supported by and also rotates about the second support structure 160. The second cart bunk is also fixed to the connecting piece 64 such that rotation of either cart bunk, 60 or 160, will cause the other bunk to rotate the same distance.
The two turner bunks 60 and 160 define a cart bunk flat plane on which a metal slab 10 (shown in phantom) will be received from the slab turner in a substantially horizontal position relative to the cart base 50. A toe cap mechanism 62 and 162 is rotatably mounted to each cart bunk to preventthe slab 10 from sliding off the cart bunk plane as the cart bunk rotates the slab towards a substantially vertical or other non-horizontal position. The toe cap mechanism and the cart bunk rotate independently butare connected via a toggling mechanism 66 and 166 between a projected position perpendicular to the cart bunk plane, preventing a slab from sliding in the plane, and a retracted position below and out of the cart bunk plane, exposing the outside edge of the slab for scarfing as seen forexample in FIGS. 8-10. The toggling mechanism is preferably a fluid-actuated ram pivotally connected at its cylinder end on the cart bunk 60 and 160 and at its ram end on the toe cap mechanism 62 and 162.
A fluid actuated ram 80 is pivotally mounted at its cylinder end to the cart base 50 near the bottom of the cart bunk support structure 70. The ram end of the fluid actuated ram is pivotally fixed to a medial position 60b on the turner bunk distantly from the cart bunk axis of rotation 64. The fluid actuated ram 80 expands and retracts, rotating the cart bunk about the cart bunk axis of rotation 64 relative to the cart base 50. Rotating from a substantially horizontal position relative to the cart base 50, the turner bunk has at least 90 degrees of rotation such that a slab lying in the cart bunk plane is rotated from a horizontal position lying on its face to a vertical position lying on its edge, and beyond to another non-horizontal position.
The fluid actuated rams act on the cart bunk and toe cap mechanism via the same programmable logic controller controlling movement of the fluid actuated rams on the slab turner. The transfer cart has a separate pump providing hydraulic pressure to the fluid actuated rams on the cart. To insure synchronous movement of each fluid actuated ram 80 and 180, the pump contains an adjustable flow restricter and a pressure balance. The cart pump also provides hydraulic pressure to the fluid actuated rams 66 and 166 controlling movement of the toe cap mechanisms. A full schematic diagram of the control system of the transfer cart is essentially similar to the control system of the slab turner shown in FIG. 16.
The programmable logic controller also insures synchronous movement of the slab turner and the transfer cart relative to each other. During inverting, loading, and unloading of the slab on the transfer cart, the transfer cart is connected to the programmable logic controller through a connector 13, shown schematically in FIG. 16. The transfer cart is temporarily disconnected from the programmable logic controller as the cart moves toward the scarfing station and is reconnected during interdigitation with the slab turner.
The synchronized steps for rotating the slab are depicted in FIGS. 4-15. Asseen in FIG. 4, an overhead lifting device (not shown) first delivers a slab 10 to the bunk 13 of a rigid support structure 12 surrounding the slab turner. The rigid support structure 12 is designed to absorb the impact loading of the slab so that the overhead lifting device need not beprecisely controlled to gently deliver the slab 10 on the slab turner. At this point, the slab turner is in its parked position with the turner bunk20 located just underneath the bunk 13 of the rigid support structure. The primary 30 and secondary 38 cylinders are at their minimum strokes when the turner is in the parked position. The turner bunk is designed to receive slabs of varying widths, approximately from 32" to 78", and of varying thicknesses, approximately from 9" to 10". The overhead lifting device delivers the slab to the bunk 13 as close to the toe caps of the turner 20c as possible.
At this point in the handling cycle, the cart is also in its parked position as shown in FIG. 4. The toe cap mechanism 62 of the transfer cartis in a lowered position immediately after the previous slab has been removed from the transfer cart by the overhead lifting device at the end of the previous surface conditioning cycle. After the slab has been delivered to the bunk 13 of the rigid support structure, a sensing device 14, such as a sonic measuring device shown schematically in FIG. 16, locates the right edge of the slab as it rests on the bunk 13. This dimension is relayed to a control system, such as a programmable logic controller, to compute the transfer position of the slab on the transfer cart. The control system also controls the synchronous movement of the fluid actuated rams to create the desired path of motion of the slab turner. At the transfer position, the right edge of the slab is located asclose as possible to the toe cap mechanism 62 and 162 of the cart.
As seen in FIG. 5, the slab turner is next raised from beneath the bunk 13 of the rigid support structure 12, lifting and rotating the slab counterclockwise to a predetermined angular position of approximately 30 degrees so that the slab 10 slides down the bunk and rests against the toecap 20c of the turner bunk. Since the slab had been delivered as close as possible to the toe cap mechanism, impact loading on the toe cap mechanismby the sliding slab is minimized. The turner has also moved towards the cart bunk and a pre-calculated position on the cart bunk as determined by the sensing device 14.
Referring to FIG. 6, the turner rotates the slab clockwise back to a horizontal position as it continues to move towards the transfer cart and places the slab on the pre-calculated position on the cart bunk. The rightedge 10b of the slab 10 is always placed at the same point on the cart bunk60 so as to not interfere with the toe cap mechanism 62 and 162 when the bunk is raised to a position parallel with the cart bunk. In this position, the cart bunk and turner bunk simultaneously support the slab. The primary 30 and secondary 38 cylinders are in their extended positions.
The turner bunk is next lowered below the level of the cart bunk as seen inFIG. 7, so that the toe caps 20c may pass under the slab. The slab now rests completely on the cart bunk. The turner is then withdrawn from underneath the slab. The cylinders 30, 38 and 42 are controlled to keep the turner bunk in substantially a horizontal position as it is withdrawn from underneath the transfer cart so as to avoid interfering with the slab.
As seen in FIG. 8, the turner next maneuvers under the slab and returns to its parked position. The turner remains in its parked position for the next several steps in the surface finishing process. After the turner has returned to its parked position, the toe cap mechanism 62 on the cart is raised to the same level as the transfer cart bunk.
As seen in FIG. 9, after the toe cap mechanism 62 and 162 is raised, the cart bunk is rotated clockwise towards the turner to a predetermined position of 75 degrees from horizontal so that the slab may slide down thecart bunk and rest against the toe cap mechanism. This position is the 75 degree surface scarfing position. In this position, the cart leaves the turning station and is driven along the guide rails into the scarfing station where the slab's first surface is scarfed, preferably by carrying the slab past stationary scarfing equipment.
After the slab's first surface is scarfed, the slab is raised to a horizontal position with the toe cap mechanism 62 and 162 lowered to approximately 37 degrees as seen in FIG. 10. In this position, the slab's first edge can be scarfed without interference from the toe cap mechanism 62.
After the first outside edge is scarfed, the slab must be turned to scarf the other flat surface and outside edge. Referring to FIG. 11, the toe capmechanism is raised and the cart bunk is once again rotated clockwise 75 degrees from horizontal to the same surface scarfing position as shown in FIG. 9. This rotation can occur while the cart is in the scarfing station or when the cart returns to the turning station, or while in transit.
After the cart bunk is rotated and is in proper position at the turning station, the turner is once again activated, rotating and moving the turner bunk towards the tilted slab. The turner bunk eventually overlaps or interdigitates with the cart bunk while the slab is sandwiched in between the turner bunk and cart bunk and is concurrently supported by both. Both bunks are rotated clockwise as seen in FIGS. 12 and 13 until the slab rests solely on the turner bunk. Once the slab rests solely on the turner bunk, the turner bunk is withdrawn from the cart bunk as seen in FIG. 14. As the slab approaches a horizontal position on the slab turner, the slab is turned upside down as shown by the arrows on the slab.
A seen in FIG. 15, the turner then repeats the motion of placing the inverted slab on the cart for scarfing and moving the cart to the scarfingstation. The steps for scarfing the first outside surface and edge are thenrepeated to scarf the second outside surface and edge, with the turner having returned to the park position. Once the entire slab is scarfed, thecart returns to the turning station with the cart bunk positioned horizontally and with the toe cap mechanism raised as shown in FIG. 5. Theslab may then be removed from the cart by the same overhead lifting mechanism which has deposited the next slab on the bunk 13 of the support 12 at the turning station.
The present invention provides several advantages over the prior art. Sincethe transfer cart moves relative to the stationary scarfing equipment, the slab velocity is controlled more accurately by movement of the cart, not the scarfing machine.
The present invention requires use of an overhead lifting device only twiceduring the scarfing cycle i.e. to load an unfinished slab and unload the scarfed slab. Since the overhead lifting device is not required to turn the slab, handlings by the overhead lifting device, and thus wear and maintenance, are reduced by one half. Reduced demand on the overhead lifting device will effect an increase in production as well. Safety is also improved since the heavy slabs are lifted positively from underneath the slab by the turner as opposed to being lifted from its top surface by a set of magnets on lifting device.
In accordance with prior conventional practices, slabs are delivered directly on to movable carts for scarfing or other purposes. Since the overhead lifting device cannot be controlled with precision while delivering the slabs, impact loading has deleterious effects on the movable carts. In the present invention, the slab is initially delivered to a sturdy, well-supported rigid structure capable of withstanding repetitive impact loading. This reduces the wear on both the slab turner and the transfer carts since the slab turner is capable of gently delivering the slab on the transfer cart without significant impact loading.
The present invention also reduces personnel involvement in the scarfing process which becomes more automated. Loading of the cars is more efficient since each slab only occupies one cart during the scarfing process.
The present system is capable of handling slabs of widths varying from 2 feet to 7 feet. The slab turner is capable of changing its path of motion to accommodate various slabs and to deliver various slabs to the optimum position on the transfer cart to minimize impact loading on the transfer cart toe cap mechanism.
The transfer cart in the present invention is also adapted to receive slabsof various widths. Additionally, the toe cap mechanism of the transfer cartis retractable which allows the outside edges of the slab to be scarfed while loaded on the cart. The retractable toe cap mechanism also allows the cart to be more easily loaded and unloaded at the slab turning station.
While particular embodiments of the present invention have been herein illustrated and described, it is not intended to limit the invention to such disclosures but changes and modifications may be made therein and thereto within the scope of the following claims. | Handling apparatus for metal slabs comprising a slab turner and a transfer cart. The slab turner receives the metal slab and transfers it to a bunk on the cart which tilts the slab so that one surface of the slab is upward. The cart moves the slab through a scarfing station which scarfs the upwardly-directed surface of the slab. The cart moves back to the slab turner and the slab turner cooperates with the transfer cart to receive the slab from the transfer cart and return the slab to the transfer cart bunk with the opposite surface upward, whereupon the transfer cart again moves the slab into the scarfing station for scarfing the opposite surface. In the scarfing station, the transfer cart supports the slab in a tilted position by toe portions underlying one edge of the slab, and enables rotation of the slab to a generally horizontal position which exposes the edge which supports the slab in the tilted position, so that the edge may be scarfed while the slab is generally horizontal. | 1 |
BACKGROUND OF THE DISCLOSURE
The present disclosure is directed to a milling machine for milling long sections from a cased well. It particularly finds application were a well has been operated for a substantial period of time at a specified depth and is ultimately depleted so that reentry is necessary. It is especially helpful where reentry and recompletion involves horizontal drilling, namely, deviation of the well from the original vertical course of the well. Briefly, consider as an example a well that is extended into a particular formation at a depth of 8,000 feet. Assume that the formation production slumps, and becomes unprofitable. Assume further that the formation is known to be a productive formation. In this instance, it is desirable to extend the well to another portion of that same formation. This can be accomplished by well reentry above the formation, drilling on a curvature to reenter the formation with a well segment which is approximately horizontal. To do this, the well must be reentered a few hundred feet above the formation, and that typically requires cutting away a portion of the casing that was placed in the well to the depth of 8,000 feet or greater. In that instance, reentry must begin by cutting away the casing so that drilling through the sidewall can be accomplished after the subsequent recompletion process begins with removal of a window of the casing. Sometimes, two or three hundred feet of the casing must be removed. Practically speaking, the only process for removal is cutting it away in the fashion of milling. Milling machines are known. The present apparatus, however, is an improved miller which enables the milling of several hundred feet, perhaps two or three hundred feet of casing, and this can be done by operating in a continuous fashion. It enables longer knives to be used, permitting greater wear on the knives, and thereby reducing trips into the well to service the cutter mechanism. It is operated in response to pressure in the drill string. Moreover, it provides a set of knives which extend radially outwardly, thereby enabling the tool to enter through a relatively narrow previously cased well.
On the latter point, consider the typical dimensions. When the well is first drilled, it typically will be drilled with a drill bit forming a hole of perhaps seven and one half inches or larger diameter. Subsequently, a casing string will be placed in the well and cement will be placed in the annular space on the exterior of the casing. This will leave an internal passage through the casing which is much smaller, perhaps in the range of about five inches diameter. When a reentry program is initiated, the milling device must be lowered on a string of drill pipe where all this equipment fits within the cased well. In other words, clearance is tight, and the room necessary for easy rotation during drilling procedures at reentry is very snug.
To this end, the present apparatus provides a milling device which has retracted knives which are not extended until they are at the depth in the well where extension is necessary. It is extremely helpful to have this improved clearance tool so that reentry at great depths can be accomplished. Reentry is thus initiated by milling a long window in the casing. In this particular instance, the present invention enables reentry and cutting of a long window, even as long as three hundred feet. Typically, this can be accomplished with a single trip into the well after cut out is first made thereabove.
The present apparatus is thus a milling device which includes an elongate outer body. There is an internal mandrel within the body and it is mounted for movement between upper and lower positions. The mandrel is positioned adjacent to and beneath a set of knife blades. The knife blades are mounted so that they can extend radially outwardly. They have a first position where the knife blades are retracted; alternately, they are extended by upward movement of the mandrel. The mandrel is forced into the operative position, causing knife blade extension, by application of increased pressure in the drill string. The tool incorporates a drill string pressure fluid receiving chamber, and the chamber, on expansion, forces the mandrel to move upwardly. The mandrel in constructed with an external surface including an enlarged shoulder which slides under or beneath the set of knife blades, forcing them radially outwardly and moving the knife blades into a cutting position.
The present apparatus further is able to thereafter begin milling, and to mill the casing by continuous rotation of the drill string. This can continue as long as required so that the casing is removed for a designated length. It is not uncommon to require a milled window of three hundred feet in length. If the number of trips can be reduced by the use of the present invention, a very desirable result is accomplished, namely, the milling process can be accomplished much more rapidly.
The present disclosure sets forth an apparatus which threads to the lower end of a drill string to fit within a cased hole. It incorporates a top sub for connection with the drill string. A drain sub is threaded to that and supports an internal drain sleeve. A circulating port connects through the two of these to an internal axial passage. A drain plug fits in the axial passage and has a narrow passage therethrough, and is attached by means of a shear pin. The drain sub is activated only if the tool cannot retract the knives, after milling, with ordinary procedures. When the drain sub plug shears, it opens ports for circulation, and also pushes the piston into the relaxed position. This can be sheared on dropping a sphere into the drill string for closure purposes. The drain sub connects with a surrounding outer body extending therebelow. That encloses a telescoped mandrel. The mandrel connects with the axial passage, has a protruding stinger, and defines an axial passage the full length of the mandrel to a chamber at the lower end of the mandrel. This chamber serves as a fluid expansion chamber. When fluid is introduced into this chamber under pressure, it forces the mandrel upwardly. This chamber is selectively connected to the exterior by means of matching ports which align on upward movement of the mandrel so that fluid can flow into the chamber and into the annular space on the exterior of the tool for flowing upwardly to wash cuttings away from the knives. There is an annular space around the mandrel located within the outer body to receive a set of knives, and the knives extend radially outwardly when the mandrel moves upwardly. The knives are supported for movement outwardly. At the front end of the knives, they are guided by a dovetail arrangement to direct the knives outwardly. The mandrel is provided with changes in diameter defining a set of slots or steps which guide the back ends of the respective knife blades. This extends the knife blades outwardly and locks them so that they are held radially outwardly for cutting exteding through ports or slots formed in the tubular outer body. This operates based on a shoulder means forcing the knives radially outwardly in response to upward movement of the mandrel.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof 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.
FIG. 1 is a lengthwise sectional view through the tool of the present disclosure showing a retracted set of knives which extend radially outwardly on axial movement of a mandrel within the outer body, and which are shown retracted for running in a cased well;
FIG. 2 is a sectional view along the line 2--2 showing details of construction of the guide mechanism which stabilizes the knives in the retracted position;
FIG. 3 is a sectional view along the line 3--3 of FIG. 1 showing details of construction of several knives which retract or extend radially outwardly operating with slots in the mandrel and surrounding outer body;
FIG. 4 is a view similar to FIG. 1 which shows the mandrel in the raised position forcing the cutting knives outwardly;
FIG. 5 is a view along the line 5--5 of FIG. 4 showing deployment of the knives radially outwardly for cutting the surrounding cased well; and
FIG. 6 is a sectional view across the dovetail which supports the knife blades for retraction and extension.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present apparatus is identified generally by the numeral 10 in FIG. 1 of the drawings. There, it is shown on the interior of a casing 11 which has been cemented in a well borehole. The casing 11 typically is positioned in a well when the well is first completed and it normally is removed months or years later to complete a reentry into the well to redrill at least a portion of the well to enhance production. The retractable milling apparatus of the present disclosure 10 is run into the well on a drill string and is operated to cut the casing 11 of several hundred feet in length. It is first positioned in the well by running it into the well on the drill string from the well head with retracted knives as will be apparent from the discussion. The window is cut in the casing 11 which has been illustrated without surrounding cement or adjacent formations for clarity.
Considering the milling apparatus 10 from the top end, there is a top sub 12 which is threaded at 13 for joinder with a string of drill pipe. An axially hollow passage 14 provides a path for mud flow. The top sub threads to a drain sub 15 which extends the tool at a common external diameter. The sub 15 encloses and surrounds a drain sleeve 16 which is axially hollow along its length. It is fixedly joined by a locking shoulder to the surrounding sub. It is axially hollow and the upper end thereof encloses a drain plug 17 which is also axially hollow. That is held in position by a shear pin 18 which can be sheared for reasons to be described. When sheared, it is forced downwardly by pressure. This downward movement exposes a circulating port 19. The port 19 extends laterally to the exterior so that a circulation path is defined through the top sub and to the exterior. The purpose of this circulating port and this optional flow path will be explained later.
A long stinger 20 is located in the axial passage in the drain sleeve 16. This stinger is able to telescope upwardly and downwardly. With appropriate seals at the upper end, it defines an exclusive flow path to the bottom of the tool as will be described. The stinger 20 is a centralized appendage to the mandrel 21 also shown in FIG. 2 of the drawings. The mandrel has a fairly large diameter as shown at the left side of FIG. 1, but it is formed with lengthwise slots as shown on the right side of FIG. 1. The slots align with the knife blades to be described.
The drain sub is fixed in location. It terminates at an external thread on an appended skirt, thereby threading to an axially hollow elongate tubular outer body 22. In addition, a ring 23 is located on the interior and abuts the skirt at the bottom end of the drain sub. This skirt supports a thin platelike appendage which extends into the slot, the appendage or plate 24 being constructed with a wedge-shaped lower shoulder. As shown in FIG. 1, the appendage 24 is a wedge cooperative with the knife blade therebelow for extension of the knife blade. The wedge 24 is shown in FIG. 2 in the retracted position, and this further shows how duplicate wedges are located in the respective slots around the mandrel 21. The mandrel is guided so that rotational movement is forbidden. Telescoping movement upwardly as shown in FIG. 1 is permitted. When this occurs, the stinger 20 moves upwardly as shown in FIG. 4. Likewise, the mandrel 21 moves upwardly so that the wedge 24 relatively moves down to contact the knives. The narrow slots enable the wedge 24 to ride under its respective knife to cause extension. The wedge 24 has a lower tapered face which is constructed with a dovetail 26 shown in FIG. 6 of the drawings. This dovetail guides the knife during extension or retraction. The knife is constructed in the form of a guide tip 27 which extends parallel to the mandrel slot. In addition to this, the knife construction includes the blade 28 which extends radially outwardly. It is constructed with a cutting edge 29 at the lower end of the blade. The blade is mounted so that it is free to wobble left and right but it does not wobble because it fits snugly in the slot or groove along the mandrel 21. This is especially evident in FIG. 3. There, the blade is shown mounted in the radial slot so that wobble is prevented. The blade 28 incorporates a lower tip 30 which rides over the shoulder 31 which terminates the back end of each of the several slots in the mandrel. The shoulder 31 forces the blade radially outwardly. When this movement occurs, the top end of the blade is guided by the cooperative dovetail connection at 26. This enables the blade 28 to extend out from the surrounding tubular hollow body at the lower end of the milling apparatus 10. Since the apparatus includes three such blades, three separate cutters are presented adjacent to the top end of the casing 11 so that it is cut or milled away. The three cutting edges 29 accomplish milling of the full length window to be cut in the previously cased well.
The surrounding outer tubular body includes a downwardly facing shoulder 32 which defines the limits of upward travel for the mandrel 21. The mandrel 21 moves upwardly jointly moving the stinger 20 upwardly to direct flow along the mandrel. This flow path extends to the lower end of the tool. A chamber 33 is defined by lower terminal face 34 of the mandrel. The chamber 33 is a fluid expansion chamber. Fluid is directed into this chamber to cause expansion. The chamber is defined by a streamlined spherical end 35 which encloses the chamber, and there is additionally a fluid flow path out of the chamber 33. This flow path is through a flow orifice 36 which extends upwardly at an angle and is aligned with a port 37 at the top end of travel of the mandrel. The flow orifice 36 delivers fluid into the annular space surrounding the tool exterior so that fluid flows upwardly to flush away cuttings. The fluid flow is directed upwardly around the knife blades. The fluid outlet 37 is located so that fluid communication to it is denied when the mandrel is in the down position. When the mandrel telescopes upwardly (contrast FIG. 2 with FIG. 1), fluid communication is perfected. The flow orifice 36 is isolated by surrounding upper and lower O-rings. Ideally, the orifice 36 is provided with two or three duplicate passages, and the port 37 is likewise duplicated at two or three locations. The chamber 33 is optionally axially partially voided through a downwardly directed orifice so that some flow is below the tip of the tool 10.
MANDREL MOVEMENT AND COOPERATIVE KNIFE EXTENSION
Attention is directed next to FIG. 4 of the drawings. There, the stinger 20 is in the raised position because the mandrel 21 has been forced upwardly. This movement is accomplished by expansion of the chamber 33 in response to fluid delivered into this chamber. The chamber 33 is shown expanded, and the fluid flow route just mentioned is operatively connected to introduce annular fluid flow around the tool to flush this region of the knives. FIG. 4 further shows the knife 28 extended. There, it will be noted that the shoulder 31 (in the lengthwise slot) has cooperated with the knife 28 to force it radially outwardly. Knife extension is accomplished by upward movement of the shoulder 31 as noted. The knife 28 is guided in movement by the cooperative dovetail 26 mentioned. This movement is accomplished on upward travel of the mandrel, causing the knife to be guided radially outwardly. While there is some telescoping movement of the knife blade 28, this movement assures a smooth knife transition from the retracted position of FIG. 1 to the extended position of FIG. 4.
Relative scale of the apparatus should be considered, particularly the extension of the blades as shown in FIG. 4. They are extended to a length so that the casing 11 is completely milled away. If needed, the blade can extend farther to assure cutting of the entire casing and cutting of a portion of the surrounding cement which holds the casing in place. In any event, the extended knife blades are sized so that they will cut the entire casing. This cutting process begins by first forming a cut (with a cutting type section mill) in the casing to remove a short portion of casing. The milling apparatus 10 is lowered to the location below this cut. Fluid pressure is delivered through the drill string, expanding the chamber 33 and causing the mandrel to move upwardly. This forces the knife blades radially outwardly. The tool is preferably pulled upwardly and the knife blades move outwardly when freed of the constraint of the surrounding snug casing. In other words, the snug fit forces the blades to a partially retracted position. When full extension occurs, a shift in flow rate is noted at the surface because the flow orifice 36 begins delivery of fluid into the annular space. Volume flow increases and the back pressure cause by the tool in the system will drop. This assures as adequate cooling and lubricating flow past the knives. In any event, the knives extend radially outwardly and are positioned for cutting. Cutting is accomplished by rotation of the drill string imparted from the surface. Cutting proceeds so long as rotation is continued. The rate of cut is in part dependent on the rate of penetration of the knife blades into the casing 11. In turn, that depends in part on the rotary speed and speed of advancement. It is possible to mill away great lengths of casing including casing collars and the like. This milling process continues until the window of suitable length has been cut. For instance, it is not uncommon to require milling of a window which is perhaps two hundred feet in length, or sometimes even as long as three hundred feet.
Attention is directed again to the top portions of FIG. 1. This shows a circulating port, but it is blanked by the drain plug which is on the interior. the drain plug, however, can be knocked loose. If the situation requires enhanced circulation through the tool, a small sphere is dropped in the string of drill pipe and ultimately lands in the top sub passage 14 and plugs the drain plug. When this occurs, the pump pressure at the surface will kick, indicating blockage. Pressure is then increased sufficiently that the shear pin 18 is broken. The shear pin will break, releasing the drain plug for downward movement. This downward movement is sufficient to expose the circulating port and direct fluid flow to the exterior from the near top portions of the tool. This is involved in the tool release procedure.
Retrieval of the present apparatus is easily achieved. It is achieved simply by lifting up on the string of drill pipe that supports the tool, and reducing pressure of the drilling fluid in the drill string. Pressure drop in the drill string permits the chamber 33 to be reduced in size. Indeed, the mandrel 21 telescopes downwardly. When it does, the shoulder 31 at the bottom end of the knife is pulled away while the wedge at the top end relatively remains primarily for the purpose of guiding the knife blade in retraction. Upward movement against any kind of fluid resistance, or snagging on any protrusion in the casing deflects the separate and independent knife blades 28 downwardly. Downward movement is accompanied with retraction, and when retraction occurs, the blades are pulled out of engagement with the casing 11 and are retracted ultimately to the full line position of FIG. 1. At this time, rapid retrieval from the cased well can be undertaken.
One important feature of the present disclosure is the shape of the cutter blades which assists in providing a long operating life. Specifically, the cutter blades are constructed with helpful features which keep the blades engaged with the structure to avoid chatter and excessive wear resulting from chatter. First of all, FIG. 6 shows the dovetail arrangement 26 at the forward or top end of the cutter blades. The dovetail provides positive guidance so that each cutter blade makes a guided transition from the retracted position of FIG. 1 to the extended and cutting position of FIG. 4. This guidance occurs from the front or top end of the cutter blade, and is a positive mode of engagement so that blade stability is assured. In addition to that, the cutter blades are recessed in slotted lengthwise cavities as shown in the sectional views of FIGS. 3 and 5. The blades are retracted in FIG. 3 and extended in FIG. 5. The blades are provided with an inverted Tee so that interlocking lips or shoulders extend along the lengthwise edges of the blades. In the extended position of FIG. 5, the blades nest up against the overhang so that they are locked in the slots. So to speak, the supportive slots for the blades are undercut to define left and right edge located overhanging interlocking lips. This assures that the blades are held with maximum supportive contact. This maximum contact assists in preventing chatter, wobble and premature wear.
Another factor that is important to the extension of the blades is the tapered back face 31 which assists in cutter blade extension. When the blades extend, they are held by the dovetail engagement at the forward end of each blade, discussed above, and they are additionally held by the lengthwise side located interlocks just mentioned. This enhances blade stability during machining. Moreover, this enhances operation of the device so that cutter blade wear and tear is extended to the maximum life.
In summary, the present apparatus is especially adapted for milling long distances. It is provided with separate and independently extended, independently replaced knife blades which are substantial so that substantial wear can be tolerated in use. Moreover, the tool is assembled in such a fashion that knife blade replacement can be easily accomplished at the surface. Disassembly is accomplished probably prior to each and every use of the tool because this assures that a full width, unused knife blade is installed. This helps the tool to stay engaged for longer periods of time. In other words, the continual engagement necessary for operation to assure cutting of the full length of the hundreds of feet in the casing window is then obtained.
While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow. | A milling apparatus is disclosed. The structure includes first and second upper subs threading together and having an inner axial passage. A long stinger fits in this passage and connects with a mandrel which is telescoped within an outer tubular body for a vertical or telescoping movement. The mandrel is formed with lengthwise slots, enabling independent knives to be positioned in each of the slots. The knives are engaged for controlled radial deflection by a dovetail connection, and the slots terminate at a sloping shoulder to force the individual cutters radially outwardly. An expansion chamber below the mandrel forces the mandrel upwardly with respect to the surrounding outer tubular body, causing the cutters to extend through individual lengthwise slots in the outer tubular body to the cutting position. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2010-102729, filed on Apr. 27, 2010 and Japanese Patent Application No. 2011-057014, filed on Mar. 15, 2011, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] (i) Technical Field
[0003] The present invention relates to an optical semiconductor device and a method of manufacturing an optical semiconductor device.
[0004] (ii) Related Art
[0005] Japanese Patent Application Publication No. 2000-174389 discloses a semiconductor laser in which a p-type InP, an n-type InP and a p-type InP bury a mesa stripe including an active layer. The semiconductor laser may be manufactured through a process of burying the mesa stripe by laminating the p-type InP, the n-type InP and the p-type InP after forming the mesa stripe.
SUMMARY
[0006] It is effective to narrow a hole leak path, in order to reduce a threshold current of a semiconductor laser. In concrete, two ways of arranging an n-type InP burying layer closer to a p-type cladding layer and reducing a thickness of the p-type cladding layer are effective.
[0007] However, it is difficult to make a distance between the n-type InP burying layer and the p-type cladding layer constant in a wafer face, because of temperature distribution in the wafer face and a decomposition rate difference of material gas, and so on. This may result in variation of a narrowed width. A mask is formed on the p-type cladding layer when growing the burying layer selectively. The mask may cause a distortion of the active layer when the thickness of the p-type cladding layer is reduced. Therefore, the thickness of the p-type cladding layer must be larger. Accordingly, it is difficult to narrow the hole leak path.
[0008] It is an object of the present invention to provide an optical semiconductor device of which leak path is narrowed, and a method of manufacturing the optical semiconductor device.
[0009] According to an aspect of the present invention, there is provided a method of manufacturing an optical semiconductor device including: forming a mesa structure including a first conductivity type cladding layer, an active layer and a second conductivity type cladding layer in this order on a first conductivity type semiconductor substrate, an upper most surface of the mesa structure being constituted of an upper face of the second conductivity type cladding layer; growing a first burying layer burying both sides of the mesa structure at higher position than the active layer; forming a depressed face by etching both edges of the upper face of the second conductivity type cladding layer; and growing a second burying layer of the first conductivity type on the depressed face of the second conductivity type cladding layer and the first burying layer.
[0010] According to another aspect of the present invention, there is provided an optical semiconductor device including: a mesa structure having a first conductivity type cladding layer, an active layer and a second conductivity type cladding layer in this order on a first conductivity type semiconductor substrate; a first burying layer burying both sides of the mesa at higher position than the active layer; a depressed face provided at both edges of an upper face of the second conductivity type cladding layer; and a second burying layer provided on the depressed face and the first burying layer, the second burying layer being the first conductivity type.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1A through FIG. 1D illustrate a method of manufacturing a semiconductor laser in accordance with a comparative embodiment;
[0012] FIG. 2A through FIG. 2D illustrate a method of manufacturing a semiconductor laser in accordance with a first embodiment;
[0013] FIG. 3A through FIG. 3D illustrate the method of manufacturing the semiconductor laser in accordance with the first embodiment;
[0014] FIG. 4 illustrates the method of manufacturing the semiconductor laser in accordance with the first embodiment;
[0015] FIG. 5 illustrates an enlarged view of a mesa stripe;
[0016] FIG. 6 illustrates current characteristics of a semiconductor laser;
[0017] FIG. 7A illustrates a schematic cross sectional view of a semiconductor laser in accordance with a second embodiment;
[0018] FIG. 7B illustrates a method of manufacturing the semiconductor laser in accordance with the second embodiment;
[0019] FIG. 8 illustrates a schematic cross sectional view of a semiconductor laser in accordance with a third embodiment; and
[0020] FIG. 9 illustrates current characteristics of a semiconductor laser.
DETAILED DESCRIPTION
[0021] A description will be given of a best mode for carrying the present invention.
Comparative Embodiment
[0022] FIG. 1A through FIG. 1D illustrate a method of manufacturing a semiconductor laser in accordance with a comparative embodiment. As illustrated in FIG. 1A , a mesa stripe is formed on an n-type InP substrate 10 . The mesa stripe has a structure in which an active layer 20 and a p-type cladding layer 30 are provided on an n-type cladding layer 11 . A mask 40 made of SiO 2 is formed on the p-type cladding layer 30 of the mesa stripe.
[0023] Next, as illustrated in FIG. 1B , a first burying layer 50 and a second burying layer 60 are grown on the n-type InP substrate 10 in this order on both sides of the mesa stripe. In this case, the first burying layer 50 is grown so that an end of the first burying layer 50 on the side of the mesa stripe is higher than an upper face of the active layer 20 . The first burying layer 50 is made of p-type semiconductor. The second burying layer 60 is made of n-type semiconductor.
[0024] Then, as illustrated in FIG. 1C , a third burying layer 70 made of p-type InP is grown so as to cover an upper face of the p-type cladding layer 30 and an upper face of the second burying layer 60 , after removing the mask 40 . The p-type cladding layer 30 and the third burying layer 70 act as a p-type cladding layer. A contact layer 80 made of InGaAs or the like is grown on the third burying layer 70 . After that, a needed electrode is provided. With the processes, the semiconductor laser in accordance with the comparative embodiment is manufactured.
[0025] In the semiconductor laser in accordance with the comparative embodiment, an contact area between the p-type cladding layer 30 , the third burying layer 70 and the first burying layer 50 gets larger. Therefore, an amount of hole leak from the p-type cladding layer 30 and the third burying layer 70 to the first burying layer 50 is enlarged. In this case, a threshold current is increased, and direct modulation property is degraded. So, the hole leak may be restrained by arranging the n-type InP burying layer 60 closer to the p-type cladding layer 30 and reducing a thickness of the p-type cladding layer 30 .
[0026] However, it is difficult to keep a distance between the n-type InP burying layer 60 and the p-type cladding layer 30 constant in a wafer face, because of temperature distribution in the wafer face, a decomposition rate difference of raw material gas, or the like. This may result in variation of narrowed width. It is necessary to provide the mask 40 on the p-type cladding layer 30 in order to grow the first burying layer 50 and the second burying layer 60 on an area except for the mesa stripe. When the thickness of the p-type cladding layer 30 is reduced, the mask 40 causes a strain in the active layer 20 . Therefore, the thickness of the p-type cladding layer 30 must be increased in the manufacturing method in accordance with the comparative embodiment. It is therefore difficult to narrow the hole leak path.
First Embodiment
[0027] A description will be given of a method of manufacturing a semiconductor laser in accordance with a first embodiment. FIG. 2A through FIG. 4 illustrate the method of manufacturing the semiconductor laser in accordance with the first embodiment. As illustrated in FIG. 2A , the n-type cladding layer 11 , the active layer 20 and the p-type cladding layer 30 are grown on the n-type InP substrate 10 . Next, the mask 40 is formed in a stripe shape on an area of the p-type cladding layer 30 where the mesa stripe is to be formed.
[0028] The n-type InP substrate 10 is, for example, made of n-type InP in which Sn (tin) of 1.0×10 18 /cm 3 is doped. The n-type cladding layer 11 is, for example, made of n-type InP having a thickness of 0.5 μm in which Si (silicon) of 1.0×10 18 /cm 3 is doped. For example, the active layer 20 has an InGaAsP-based multiple quantum well structure. The p-type cladding layer 30 is, for example, made of p-type InP having a thickness of 0.2 μm in which Zn (zinc) of 1.0×10 18 /cm 3 is doped. For example, the mask 40 is made of SiO 2 .
[0029] Next, as illustrated in FIG. 2B , the p-type cladding layer 30 , the active layer 20 and the n-type cladding layer 11 are subjected to a dry etching process with use of the mask 40 as an etching mask. Thus, a mesa stripe is formed on the n-type InP substrate 10 . For example, RIE (Reactive Ion Etching) method using SiCl 4 may be used as the dry etching process. A height of the mesa stripe without the mask 40 is, for example, 1.5 μm to 2.0 μm.
[0030] Then, as illustrated in FIG. 2C , the first burying layer 50 and the n-type burying layer 61 are grown on the n-type InP substrate 10 on both sides of the mesa stripe. In this case, the first burying layer 50 and the n-type burying layer 61 are selectively grown on an area except for the mask 40 . The first burying layer 50 is grown so that an end of the first burying layer 50 on the side of the mesa stripe is higher than an upper face of the active layer 20 . The first burying layer 50 is p-type semiconductor layer or highly-resistive semiconductor layer in which impurity (deep acceptor) such as Fe, Ti or Co generating deep acceptor level is doped. For example, the first burying layer 50 may be made of InP having a thickness of 1.3 μm in which Zn (Zinc) of 5.0×10 17 /cm 3 is doped or made of InP having a thickness of 1.3 μm in which Fe (iron) of 7.0×10 16 /cm 3 is doped. The n-type burying layer 61 is, for example, made of n-type InP having a thickness of 0.2 μm in which S (sulfur) of 1.0×10 19 /cm 3 is doped.
[0031] Next, as illustrated in FIG. 2D , the mask 40 is subjected to an etching process. Thus, the upper face of the mask 40 , and both end portions of the mask 40 on the side of the first burying layer 50 is etched. Thus, both end portions of the p-type cladding layer 30 on the side of the first burying layer 50 are exposed. A BHF (Buffered Hydrofluoric Acid) may be used in the etching process of FIG. 2D .
[0032] Then, as illustrated in FIG. 3A , the exposed face of the p-type cladding layer 30 is subjected to an etching process. In this case, a face lower than the upper face of the mesa stripe (depressed face) is formed on both sides of the mesa stripe. For example, the p-type cladding layer 30 has only to be etched by approximately 0.1 μm. A liquid (NH 3 :H 2 O 2 is 1:1) may be used as the etching liquid.
[0033] Next, as illustrated in FIG. 3B , an n-type burying layer 62 is grown so as to cover the area of the p-type cladding layer 30 removed through the etched area of the p-type cladding layer 30 and the n-type burying layer 61 . The n-type burying layer 62 is, for example, made of the same material as the n-type burying layer 61 . The n-type burying layer 62 is, for example, made of n-type InP having a thickness of 0.25 μm in which S (sulfur) of 1.0×10 19 /cm 3 is doped.
[0034] Then, as illustrated in FIG. 3C , the third burying layer 70 is grown so as to cover an upper face of the p-type cladding layer 30 and an upper face of the n-type burying layer 62 . Further, a contact layer 80 is grown so as to cover an upper face of the third burying layer 70 . The third burying layer 70 is made of p-type semiconductor. The third burying layer 70 is, for example, made of the same material as the p-type cladding layer 30 . The third burying layer 70 is, for example, made of p-type InP having a thickness of 2.0 μm in which Zn (Zinc) of 1.2×10 18 /cm 3 is doped. The contact layer 80 is made of a material having a band gap that is narrower than that of the third burying layer 70 . The contact layer 80 is, for example, made of p-type InGaAs having a thickness of 0.5 μm in which Zn (zinc) of 1.5×10 19 /cm 3 is doped. As illustrated in FIG. 3D , the p-type cladding layer 30 and the third burying layer 70 act as a p-type cladding layer 75 . The n-type burying layer 61 and the n-type burying layer 62 act as the second burying layer 60 .
[0035] Next, as illustrated in FIG. 4 , an n-type electrode 91 is formed on a bottom face of the n-type InP substrate 10 . A passivation film 92 is formed on the contact layer 80 except for an area above the mesa stripe. And, a p-type electrode 93 is formed so as to cover the exposed area of the contact layer 80 and the passivation film 92 . The n-type electrode 91 is, for example, made of AuGeNi. The passivation film 92 is made of an insulating material such as SiO 2 . The p-type electrode 93 is, for example, made of TiPtAu.
[0036] With the processes, a semiconductor laser 100 is manufactured. A MOVPE (Metal Organic Vapor Phase Epitaxy) method may be used when growing above-mentioned semiconductor layers. Growth temperature in the MOVPE method may be approximately 600 degrees C. The InP is made from trimethyl indium and phosphine. Dimethyl zinc may be used for when doping Zn (zinc). Ferrocene may be used for when doping Fe (iron). Hydrogen sulfide may be used for when doping S (sulfur). Disilane may be used for when doping Si (silicon).
[0037] In the embodiment, the processes of FIG. 2D and FIG. 3A are performed after growing the n-type burying layer 61 . However, the manufacturing method is not limited to the embodiment. For example, in the process of FIG. 2C , the n-type burying layer 61 may not be grown. The second burying layer 60 may be grown after the etching process of FIG. 3A .
[0038] FIG. 5 illustrates an enlarged view around of the mesa stripe. As illustrated in FIG. 5 , a thickness of a part contacting area of the p-type cladding layer 75 with the first burying layer 50 is reduced through the etching process. Thus, the hole leak path is narrowed. Therefore, the threshold current is reduced, and the direct modulation property is improved. The thickness of the contacting area is controlled better in the etching process than in the growth method. Thus, the thickness variation of the contacting area in a wafer face may be restrained. Therefore, variation of the narrowed width is restrained. And, the distortion of the active layer 20 caused by the mask 40 is restrained because the area of the p-type cladding layer 30 on where the mask 40 is provided is relatively thick.
[0039] FIG. 6 illustrates current characteristics of the semiconductor laser. In FIG. 6 , a horizontal axis indicates a current provided to the semiconductor laser, and a vertical axis indicates an outputting power of the semiconductor laser. FIG. 6 illustrates the current characteristics of the semiconductor laser 100 in accordance with the first embodiment and the semiconductor laser in accordance with the comparative embodiment. An element length L is 200 μm. A measuring temperature is 75 degrees C.
[0040] As illustrated in FIG. 6 , the threshold current of the semiconductor laser 100 was lower than that of the semiconductor laser in accordance with the comparative embodiment. The outputting power of the semiconductor laser 100 was higher than that of the semiconductor laser in accordance with the comparative embodiment. This is because the hole leak path is narrowed in the semiconductor laser 100 .
Second Embodiment
[0041] The first burying layer 50 may have a structure in which a highly resistive semiconductor layer and a p-type semiconductor layer are laminated. FIG. 7A illustrates a schematic cross sectional view of a semiconductor laser 100 a in accordance with a second embodiment. The semiconductor laser 100 a is different from the semiconductor laser 100 of FIG. 4 in a point that a burying layer in which a highly resistive semiconductor layer 52 is laminated on a p-type semiconductor layer 51 is provided instead of the first burying layer 50 . Impurity such as Fe, Ti or Co generating deep acceptor level is doped in the highly resistive semiconductor layer 52 . With the structure, an element capacity may be reduced more, compared to a case where a p-type InP is used as the first burying layer 50 . Thus, the frequency characteristics of the semiconductor laser 100 a are improved.
[0042] FIG. 7B illustrates a method of manufacturing the semiconductor laser 100 a . As illustrated in FIG. 7B , instead of the first burying layer 50 , the p-type semiconductor layer 51 and the highly resistive semiconductor layer 52 are grown in this order on the n-type InP substrate 10 in the process of FIG. 2C when manufacturing the semiconductor laser 100 a . In this case, the highly resistive semiconductor layer 52 is grown so that an end of the p-type semiconductor layer 51 on the side of the mesa stripe is higher than the upper face of the active layer 20 . The p-type semiconductor layer 51 is, for example, made of InP having a thickness of 0.5 μm in which Zn of 5.0×10 17 /cm 3 is doped. The highly resistive semiconductor layer 52 is, for example, made of InP having a thickness of 0.7 μm in which Fe (iron) of 7.0×10 16 /cm 3 is doped.
[0043] A MOVPE (Metal Organic Vapor Phase Epitaxy) method may be used when growing the p-type semiconductor layer 51 and the highly resistive semiconductor layer 52 . Growth temperature in the MOVPE method may be approximately 600 degrees C. The InP is made from trimethyl indium and phosphine. Dimethyl zinc may be used for when doping Zn (zinc). Ferrocene may be used for when doping Fe (iron).
Third Embodiment
[0044] FIG. 8 illustrates a schematic cross sectional view of a semiconductor layer 100 b in accordance with a third embodiment. The same components as those illustrated in FIG. 8 have the same reference numerals as FIG. 4 . In the embodiment, “W” and “h” of a region between the active layer 20 and the second burying layer 60 are researched. The “h” is a height from the active layer 20 to a lower face of the second burying layer 60 formed in the process of FIG. 3A . The “W” is a width of the depressed face of the second burying layer 60 above the active layer 20 .
[0045] Samples 1 to 3 of Table 1 were manufactured having a different combination of “W” and “h”.
[0000]
TABLE 1
HEIGHT h
WIDTH W
(nm)
(nm)
W/h
SAMPLE 1
120
200
1.7
SAMPLE 2
100
200
2.0
SAMPEL 3
80
160
2.0
[0046] FIG. 9 illustrates the current characteristics of the samples 1 to 3 of the semiconductor laser 100 b . In FIG. 9 , a horizontal axis indicates a current provided to the semiconductor lasers, and a vertical axis indicates outputting power of the semiconductor lasers. An element length L is 200 μm. A measuring temperature is 75 degrees C. The width of the active layer 20 is 1.2 μm. As illustrated in FIG. 9 , an operating current Iop @ 15 mW of the samples 2 and 3 at an outputting power of 15 mW is lower than the sample 1. This means that the rising efficiency or slope efficiency (mW/mA) is increased, compared to the sample 1.
[0047] In the sample 3, the “W” is reduced further than in the sample 2, and the “h” is smaller than in the sample 2. The amount of hole leak has a correlation with the region defined by the “h” and the “W”. Increasing of the resistance value of the region may cause the reduction of the hole leak. The resistance value of the area defined by the “W” and the “h” is the same in the samples 2 and 3. However, in accordance with FIG. 9 , a maximum optical outputting power of the sample 3 is larger than that of the sample 2. This is because the reduction of the “W” causes a reduction of an area shaded by the first burying layer 60 over the active layer 20 . That is, the reduction of the “W” causes an enlargement of a hole current clearance Wp with respect to the active layer 20 . Thus, conductance of the hole current is increased. The clearance Wp is defined with the second burying layer 60 formed on both sides of the mesa stripe.
[0048] According to the research with the samples 1 to 3, it is preferable that the “h” is reduced in order to reduce the hole leak. And, it is preferable that the “W” is optimally defined with the correlation between the hole leak and the hole conductance with respect to the active layer 20 . The present inventors have confirmed that it is preferable that the “h” is preferably 100 nm or less, 1.8≦W/h, and the “Wp” is 500 nm or more. It is more preferable that the “h” is 80 nm or less.
[0049] In the above mentioned embodiments, an active layer is provided on an n-type cladding layer, and a p-type cladding layer is provided on the active layer. However, the structure is not limited to the embodiments. For example, the p-type cladding layer, the active layer and the n-type cladding layer are provided in this order on a p-type semiconductor substrate.
[0050] In the above-mentioned embodiments, the semiconductor laser is used as one example of an optical semiconductor device of the present invention. However, the optical semiconductor device is not limited to the semiconductor laser. For example, another optical semiconductor device such as a semiconductor optical amplifier (SOA) is used as the optical semiconductor device.
[0051] The present invention is not limited to the specifically disclosed embodiments and variations but may include other embodiments and variations without departing from the scope of the present invention. | A method of manufacturing an optical semiconductor device including: forming a mesa structure including a first conductivity type cladding layer, an active layer and a second conductivity type cladding layer in this order on a first conductivity type semiconductor substrate, an upper most surface of the mesa structure being constituted of an upper face of the second conductivity type cladding layer; growing a first burying layer burying both sides of the mesa structure at higher position than the active layer; forming an depressed face by etching both edges of the upper face of the second conductivity type cladding layer; and growing a second burying layer of the first conductivity type on the depressed face of the second conductivity type cladding layer and the first burying layer. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a torque rod assembly adaptable for use in truck and bus applications to connect axle assemblies to frame members of vehicles. More particularly, the invention is directed to an improved torque rod assembly adaptable to a plurality of mounting angles.
While the invention is particularly directed to the art of vehicle suspension systems, and will thus be described with specific reference thereto, it will be appreciated that the invention may have utility in other fields and applications.
Torque rod assemblies are used in heavy vehicle suspension systems to maintain the stability of the axle assembly. Torque rods typically have forged ends and are attached to the axle assembly and frame members, respectively, by the use of cylindrical bar pins extending through the forged ends. Elastomer bushings may also be used in the ends of torque rods in conjunction with the bar pins to absorb shock, maintain the tracking of wheels to the centerline of travel, and resist forces and deflections encountered in turning the vehicle. A torque rod generally functions best if the elastomer bushing in the forged ends of the rod are arranged so that a longitudinal axis thereof is perpendicular to the centerline of the vehicle.
Because of design or manufacturing problems or differences, the torque rod is often misaligned in mounting, thus making it difficult to mount the rod on both the axle and the frame. When this has occurred in the past, it has been necessary to bend the spacer of the torque rod to a suitable curvature and then use special tools and operations to attach the bar pins to the ends of the torque rods, which of course adds to production costs.
Moreover, because it is harmful to subject elastomer bushings to stress prior to assembly, it has also been necessary to design and manufacture torque rods with various angles between the bar pins and the torque rod centerline. Mounting in this situation requires creating a flat surface on each end of the bar pins and piercing a hole through each end, which receives mounting bolts for attaching the bar pins to the supporting brackets. This arrangement has resulted in undesired proliferation of part numbers, increased inventory of torque rods and a heightened risk that a torque rod could be installed at an improper angle, thus leading to premature failure of the torque rod.
The subject invention contemplates a new and improved torque rod assembly that eliminates the foregoing problems and others by, among other things, reducing design, production and inventory costs; increasing mounting flexibility; and eliminating assembly mistakes and resulting premature failure of torque rod assemblies.
SUMMARY OF THE INVENTION
An improved torque rod assembly is provided for connecting a vehicle axle to a frame comprising a torque rod with forged ends, each forged end having an eyelet and a cylindrical bar pin extending therethrough wherein the torque rod assembly is adaptable to a plurality of mounting angles.
In one aspect of the invention, the bar pin extending through the torque rod eyelet has a transverse bore for receiving a bolt that is movable in a radial direction in relation to the surface of the bore.
In another aspect of the invention, an aperture of each eyelet of the torque rod between the eyelet is bored at a predetermined offset angle so that the eyelet and the bar pin extending therethrough are aligned with an axis that is perpendicular to the vehicle frame.
An advantage of the assembly is that it is less expensive to manufacture than other methods while providing the same isolation benefits.
Another advantage of the assembly is that it accommodates variations in frame to axle mounting with limited stress on elastomer bushings and metals.
Another advantage of the assembly is that it provides for mounting at a number of different angles.
Another advantage of the assembly is that it eliminates the creation of flat surfaces on the ends of the bar pins.
Another advantage of the assembly is that it reduces the number of parts required to assemble or service a particular vehicle.
Another advantage of the assembly is that it reduces the amount of inventory required for assembly and service.
Another advantage of the assembly is that it eliminates mistakes during assembly or service and resultant premature torque rod failure.
Further scope of the applicability of the present invention will become apparent from the detailed description provided below. It should be understood, however, that the detailed description and specific examples, while illustrating 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 be apparent to those skilled in the art.
DESCRIPTION OF THE DRAWINGS
The present invention exists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings in which:
FIG. 1 is a top view of selected portions of a vehicle frame, suspension and axle system having disposed therein a torque rod assembly according to the present invention;
FIG. 2 is a side view of the torque rod assembly shown in FIG. 1;
FIG. 3 is a side and partial cross-sectional view of the torque rod assembly of FIGS. 1 and 2;
FIG. 4 is a side view the bar pin attached to the axle and/or frame;
FIG. 5 is a side view of the bar pin attached to the axle and/or frame in an alternative embodiment;
FIG. 6 is a side view of the bar pin attached to the axle and/or frame in an alternative embodiment; and,
FIG. 7 is a side view of the bar pin attached to the axle and/or frame in an alternative embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, which are for purposes of illustrating the preferred embodiments of the invention only and not for purposes of limiting the same, FIG. 1 provides a view of the overall preferred embodiment of a torque rod assembly 10 installed in a vehicle. While it is appreciated that vehicle types may vary, resulting in variations of the suspension system and variations in the points of attachment of the assembly 10, as exemplary shown here, the torque rod assembly 10 generally is used in conjunction with a vehicle frame 12 and a drive axle 14. Main spring supports (not shown) connect the vehicle frame 12 to the drive axle 14.
Referring now to FIGS. 1 and 2, the torque rod assembly 10 comprises a torque rod 20 having an integral spacer 21, ends 22 and 23 and eyelets 24 and 25, respectively. Because of the high stresses involved in most applications, the torque rod ends are preferably forged rather than formed by alternative metal processing techniques. However, any sufficiently durable material or suitable method of formation may be used. The end 22 of the torque rod 20 is mounted to the drive axle 14 by a bar pin 30 and an axle mounting bracket 18. Likewise, the end 23 of the torque rod 20 is mounted to the vehicle frame 12 by a bar pin 31 and a frame mounting bracket 16. The bar pins 30 and 31 extend through elastomer bushings 40 and 41 (shown in FIG. 3) disposed in the eyelets 24 and 25, respectively. These bushings are aligned so that longitudinal axes thereof are coextensive with an axis L--L and an axis L'--L', respectively, which are substantially perpendicular to the vehicle frame so as to optimize loading conditions. As also shown in FIG. 2, the bar pins 30 and 31 are connected to the axle mounting bracket 18 and the frame mounting bracket 16, respectively, by mounting bolts 34. The bar pins 30 and 31 are substantially cylindrical in shape and may be formed from solid metal rod or metal tubing; however, any configuration or material of sufficient strength and durability will suffice.
Referring now more particularly to FIG. 3, the torque rod 20 is slanted to accommodate misalignment between the frame mounting bracket 16 and the axle mounting bracket 18. The eyelets 24 and 25 define respective cylinders, bores or apertures that are formed at a predetermined offset angle θ relative to an axis N--N that is normal to the axis T--T of the torque rod 20. Thus, the angle θ is the angle between the axes L--L and N--N and between the axes L'--L' and N'--N', respectively. The angle θ is preferably in the range of 1.0° to 10.0°; however, any suitable angle may be utilized. As an example, the bores of the eyelets 24 and 25 may be machined at the required angle θ. It is recognized, though, that the bores may be formed using any known technique.
In the preferred arrangement, longitudinal axes of the bar pins 30 and 31 and elastomer bushings 40 and 41 are coextensive with longitudinal axes L--L and L'--L' running through respective eyelets 24 and 25. As noted above, the longitudinal axes L--L and L'--L' are oriented substantially perpendicular to the vehicle frame 12 when the torque rod assembly 10 is installed. Accordingly, it is not necessary to bend the spacer 21 to mount the torque rod 20 to the axle 14 and the frame 12 of the vehicle. Any alignment adjustment is taken into account when determining the angle θ.
As noted above, elastomer bushings 40 and 41 are disposed in eyelets 24 and 25, respectively. These bushings are constructed of an elastomer material that will vary in configuration and composition, depending on the cost and durability desired. The bushings are press fit into the eyelets and maintained therein by a resulting friction fit. Alternatively, suitable bonding techniques may be used to secure the bushings in the eyelets. For example, known adhesives may be applied between the bushings and the inside surface of the eyelets to accomplish the goals of the subject invention.
The preferred elastomer bushing is generally cylindrical when compressed inside the eyelets and is 70 durometer points on the shore A scale. However, any material exhibiting elastomeric qualities, while still capable of withstanding the forces typically generated in a torque rod assembly, is suitable.
Although a variety of fastening devices and/or techniques may be used to attach one end of the torque rod 20 to the axle 14 and the other to the frame 12, torque rod assembly 10 uses alternative preferred arrangements. For example, and as shown in detail in FIGS. 4 and 5, to fix the torque rod 20 to the axle mounting bracket 18, as well as frame mounting bracket 16 (not shown), bolts 34 extend through the transverse bores 32 of the bar pins 30 (31), and are received in the threaded bores 36 of the bracket 18. The bracket 18(16) also has a contoured surface 42 to receive a mating portion of the cylindrical bar pin 30(31).
The bores 32 may be tapered as shown in FIG. 4 or uniformly oversized in relation to the outside diameter of bolts 34 as shown in FIG. 5. Either such configuration of bores 32 allows the bolts 34 to move in an arc. This, in turn, permits the torque rod assembly 10 to be mounted at a number of angles relative to the frame 12 and the axle 14. This configuration avoids the need to create a flat surface on the ends of the bar pins or to engineer a preset mounting angle.
FIGS. 4 and 5 also show a washer 38 having a flat surface on one side and a curved surface on an opposite side which is used to lock the bolt 34 securely to the mounting bracket 18(16). This washer also transmits forces through the various mating surfaces during vehicle operation.
In an alternative arrangement shown in FIGS. 6 and 7 (which alternatively show tapered and oversized bores 32), no contoured surfaces are formed on the brackets. Accordingly, another washer 38 is disposed between the bracket 18(16) and the bar pin 30(31). The bolt 34, then, extends through the first washer 38, the bar pin 30, the second washer 38, and the bore 36 of the bracket 18(16). In the embodiment shown in FIGS. 6 and 7, the bolt extends further through the bracket and is secured by nut 44.
It is to be appreciated that the determination of whether to utilize the mounting technique shown in FIGS. 4-5 or that shown in FIGS. 6-7 is dependent on the vehicle into which the assembly is installed. In addition, the choice between oversized bores or tapered bores depends on the needs of the user.
It is to be further appreciated that the embodiments shown in FIGS. 1-3 may be utilized along with conventional mounting techniques instead of those shown in FIGS. 4-7. Likewise, the mounting techniques of FIGS. 4-7 may be utilized with conventional torque rod assemblies, instead of the embodiment shown in FIGS. 1-3. Varying combinations of the disclosed embodiments may also be utilized. In all of these circumstances, though, the torque rod assembly of the present invention is adaptable to a plurality of mounting angles.
The above description merely provides a disclosure of particular embodiments of the invention and is not intended for the purposes of limiting the same thereto. As such, the invention is not limited to only the above described embodiments. Rather, it is recognized that one skilled in the art could conceive alternative embodiments that fall within the scope of the invention. | An improved torque rod assembly is provided for connecting a vehicle axle to a frame comprising a torque rod with forged ends, each forged end having an eyelet and a cylindrical bar pin extending therethrough wherein the torque rod assembly is adaptable to a plurality of mounting angles. | 1 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to a method and apparatus for measuring the applied kilovoltage of an X-ray source such as a medical X-ray machine and in particular to a method and apparatus for measuring applied kilovoltage utilizing multiple attenuation measurements through pairs of absorbers.
There is a widespread need to measure the penetrating power, as distinguished from the intensity, of X-ray sources, especially in medical and radiological equipment. Penetrating power and KV in particular are very important in the practice of medical diagnostic radiology for several reasons. The primary factor is the critical relationship between the intensity of X-ray exposure reaching the film and the KV used. For a moderal size body part, such as human head, the x-ray energy reaching the film varies approximately in proportion to the 4.5 power of the KV. This means that a 5% change in KV will lead to a 25% change in the intensity of film exposure, which will commonly lead to a degree of under or over exposure sufficient to cause a mis-diagnosis of the patients condition. This intensity to exposure conditions is due to the combination of a wide contrast range recorded on the film and the extremely subtle changes produced by many diseased states. Furthermore, the degree of image contrast obtained is primarily influenced by the KV, with different types of examinations requiring different selections of KV. For example, if a hairline fracture in the rib bone is suspected, then a relatively low KV about 60 would be used on most patients. This choice will enhance the image contrast of calcium in the bones. On the other hand, if a diseased process in the lung tissue, such as tuberculosis or cancer, is suspected then a higher KV in the range of 110 to 130 should be used to better penetrate the ribs and other bones as well as the heart. Only in this way can disease lesions which happen to lie behind the heart or ribs be seen.
In any event, it is frequently necessary to make small adjustments to the KV in order to accommodate the range of body sizes found in any patient population. Many radiology practitioners maintain technique charts listing the KV used versus body size. In this case a miscalibrated KV will produce an inadequate image which must be corrected by readjusting either the KV or other factors such as exposure time. This situation leads to unnecessary exposure of the patients. For this reason it is especially imperative that the KV calibration be uniform among the several X-ray rooms used in a radiology department. Recently, the Food and Drug Administration of the U.S. Government has recommended, and many state governments are requiring, that all medical X-ray machines be calibrated on a regular basis.
In practice, two complimentary parameters are generally used to characterize the penetrating power of an X-ray source: half value layer (HVL) and kilovolts peak (KVp). HLV is measured by determining the thickness of material (usually aluminum) necessary to reduce the reading on an air-ionization chamber to one-half the value obtained with no material. The HVL is only weakly influenced by KV.
Since applied KV will, in general, vary throughout the duration of the exposure, there are various ways of quantifying the KV used. With single phase machines, the KV applied has a sinusoidal waveform, so that the peak KV (KVp) is the common measure used. More modern X-ray machines using 3-phase current produce complex waveforms which are neither constant nor sinusoidal. In this situation a measurement of peak KV is not the most meaningful quantity. Accordingly, some sort of average or effective KV (KVe) is used.
A further desirable characteristic of any KV measuring system is that it functions accurately over a wide range of operating conditions, including variations in milliamperes (mA) of X-ray tube current and seconds of duration of exposure. Since darkening of the X-ray film is influenced by the product of mA and time, the integrated factor, mA×seconds=mAS, is used to quantify these factors. That is, it is desired to measure KVe accurately over an mAS range of approximately 1 to 100 mAS.
The most direct known method of measuring KV involves the direct interconnection of a resistor divider network into the high voltage system. This method, when used in conjunction with an oscilloscope, is capable of good accuracy if the waveform is simple--for example, either constant potential or purely sinusoidal. However, for highly complex waveform patterns such as seen on 3-phase machines, the estimation of KVe from the waveform is fraught with error. Thus, use of this method is limited principally to diagnosing certain problems in the X-ray circuitry, but is inconvenient for use in routine calibration. In addition, a major disadvantage of this approach is the necessity to carry bulky and complex equipment into the X-ray room and the dangers and inconveniences of breaking into the high voltage wiring.
It is thus desirable to be able to derive the KVe or KVp from measurements made directly on the beam of X-rays. Many methods have been suggested to accomplish this, all of which employ the same basic principle. The X-ray beam is filtered with a thickness of metal (or other substance of high atomic number (Z)) sufficiently to filter a large portion of the lower energy photons. The average energy of the remaining photons is then strongly correlated with, although less than, the applied KV. This method is more sensitive to KV changes if a high Z substance is used as the filter. The KV is commonly inferred from the ratio (R) of X-ray intensities passing through two thicknesses of filter, t 1 and t 2 . The relationship between R and KV is highly non-linear so that some sort of procedure for relating R to KV must be established for any such method. Generally, it is true that increasing both thicknesses t 1 and t 2 will increase the sensitivity of R to KV and diminish the sensitivity of R to HVL, which is desirable. However, increasing the thickness of the filters also reduces the intensity of the X-rays passing through the filters, thereby necessitating the measurement of weaker X-rays and thus making more difficult the ability to measure exposures at low mAS or low KVe.
Use of increased thickness of absorbers also simplifies the problem of relating R to KV; if t 1 and t 2 are sufficiently thick then the logarithm of the detected intensity of X-rays, I, is linearly related to the thickness of the absorber used. Such a linearity is only approximate however since the curvature of the log (I) vs. (t) relationship is related to the range of photon energies present in the beam. A linear relationship is true only if the beam is homogenous, i.e., has only one photon energy. This will never be completely true for X-ray beams generated by X-ray tubes, but becomes a more accurate approximation as absorber thickness (t) is increased.
It is the primary object of the present invention to provide an improved method and apparatus for measuring the applied KV of an X-ray source.
In addition, it is an object of the present invention to provide a method and apparatus for accurately measuring the applied KV of an X-ray source over a wide dynamic operating range.
Furthermore, it is an object of the present invention to provide an accurate KV measuring device which automatically compensates for such real world factors as a non-homogenous X-ray beam, variations in detector sensitivity, long-term electronics drift and components variation.
The KV measuring device according to the present invention employs two radiation detectors which are mounted beneath a rotatable disc within which is mounted a set of nine metallic absorbers. The filter disc is rotated by an electric motor under the control of a microprocessor computer. One function of the microprocessor is to select one of three possible KVe ranges, which in the preferred embodiment are selected to be: I=40-70 KV, II=60-100 KV, III=90-150 KV. Thus, each KV range uses three filters; two are chosen to be as close to equal in thickness, t 1 , as possible, while the third is somewhat thicker, t 2 . In the preferred embodiment, t 2 is approximately 30% larger than t 1 .
Each measurement of X-ray KVe requires that two exposures be made. In the first exposure, called the "calibration" exposure, the absorber wheel is turned so that both detectors are filtered by the two absorbers of thickness t 1 . The detected X-ray intensities are measured, processed, and stored in the digital memory for future use. Between the first and second exposures, the filter wheel is automatically advanced so that one detector is filtered by t 1 and the second detector by t 2 thicknesses, respectively. The subsequent X-ray exposure, called the "measure" exposure, provides the additional data from which KVe can be accurately calculated. Thus, each KVe is calculated on the basis for four measurements of X-ray intensity.
The purpose of the calibrate exposure is not to measure KVe but rather to establish certain calibration factors which are important in the final KVe determination, namely: the ratio of the relative intensities falling on the two detectors, the ratio of the sensitivities of the two detectors to radiation, and the ratio of the overall amplification factors of the several amplifiers and pulse shaping networks of the two channels which transfer the detector currents to the analog to digital converters. In this way, not only is the influence of a non-homogenous X-ray beam (referred to as the "heel effect") on KVe measurement eliminated, but also eliminated is any imbalance or long term drift in the electronic amplification factors. In addition, because both filters have a thickness t 1 in the calibrate mode, the ratio of the readings is not influenced by the KVe of the calibrate exposure.
Furthermore, the dynamic range of the KVe measuring device according to the present invention is enhanced by eliminating low level offset voltages and currents in the first stage of amplification. This is accomplished in the preferred embodiment by a.c. coupling of the analog signals and through real time use of the microprocessor to measure and subtract these offsets. Dynamic range of the present KVe measuring device is also enhanced by the use in the preferred embodiment of a partially integrating resister-capacitor network in the feedback loop of the first amplification circuit, so that the range of voltage produced at the output of the amplifier is determined primarily by only two factors, KVe and mAS, rather than the three parameters, KVe, mA, and time.
Another design feature which enhances the useable dynamic range of the instrument is the use of only modestly thick absorbers. In the preferred embodiment, range I uses copper filters of 0.75 and 1.0 millimeter; Range II uses 1.5 and 2.0 mm of copper, and range III uses 0.5 mm of copper as well as 1.5 and 2.0 mm of tin, respectively. These choices have the advantage of being thin enough that X-ray factors as low as 5 mAS can be used at the lower end of each KVe range.
Additional objects and advantages of the present invention will become apparent from a reading of the Detailed Description of the Preferred Embodiment which makes reference to the following set of drawings of which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an X-ray measuring system according to the present invention;
FIG. 2 is an exemplary illustration of the detector box and controller box of the present system;
FIG. 3A is a sectional view of the detector box shown in FIG. 2;
FIG. 3B is a plan view of the nine metallic absorbers in the detector box shown in FIG. 3A;
FIG. 4 is a schematic diagram of the electronic circuitry in the detector box shown in FIG. 3A; and
FIG. 5 is a flowchart diagram outlining the software program resident in the read-only memory in the controller box of the present system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a block diagram of the X-ray calibration system according to the present invention is shown. X-rays from the radiation source 11 pass through two absorbers 12 and 13 and strike detectors 14 and 15 thereby causing current to flow through lines 16 and 17 to integrating preamplifiers 18 and 19. Preamplifiers 18 and 19 convert the current to a voltage which passes through lines 20 and 21 to variable gain amplifiers 22 and 23. The amplified voltages are temporarily stored in the sample and hold circuits 26 and 27. The stored voltages are connected through lines 28 and 29 to an electronic switch 30 which selects and transfers to line 31 only one of the input voltages on line 28 or 29 according to the status of control line 32. Said selected voltage on line 31 is connected to an analog-to-digital converter 33 which transforms the voltage on line 31 to a binary coded digital signal on line 34.
Microprocessor 40 operates according to instructions stored in the read-only memory 41 and uses random access memory 42 for storage of variables. Information to control the various devices of the invention are sent through address and data bus 43, wherein the microprocessor 40 can either transmit or receive digital information from the said devices. According to the program instructions stored in the read-only memory 41 the microprocessor 40 performs the following functions:
(a) receive digital information from the analog-to-digital converter (ADC) 33 through the ADC interface 44,
(b) control the electronic switch 30 through the switch controller 45,
(c) activate the sample and hold devices 26 and 27 by means of the sample and hold controller 46,
(d) change the gain of variable gain amplifiers 22 and 23 to four different gain values by means of the gain controller 47,
(e) activate the motor 51 to rotate the filter wheel 52 by means of the motor driver 50,
(f) detect the position of the filter wheel 52 by means of the wheel position sensor 53,
(g) read the values of six potentiometers 54 by means of an analog-to-digital converter 55,
(h) by means of a switch interface 56 read the status of the manually operable front panel switches 57, and
(i) transmit information through a display interface 58 to a front panel display 59 visible to the operator.
As shown in FIG. 1, the system is divided into two parts: a detector box 60 which is disposed close to the radiation source 11 and a controller box 61 which is operable by the user. FIG. 2 shows a physical illustration of these two boxes with an interconnecting cable 62. The user sets the range switch 63 to correspond to the anticipated KV of the radiation source 11. In the preferred embodiment which is adapted for use with medical X-ray machines, the three settings provided corresponding, respectively, to the following three ranges: 40 KV to 70 KV, 60 KV to 100 KV, and 90 KV to 150 KV. The switch is shown on display 64. Switch 65 is set to correspond to radiation from a single phase radiation source 11, or from a three phase radiation source 11. Display 66 shows the computed KV of the radiation source or other status messages, such as the occurrence of an error.
Referring to FIG. 5, the program in the read-only memory 41 which controls the system operation will now be described.
(a) Power on. After the supply power is turned on the display is cleared and the status of the front panel switches is read.
(b) The motor 51 is turned on so that the filter wheel begins to rotate. The wheel position sensor 53 is monitored by the computer. When the position of the filter wheel 52 is such that the two thin absorbers corresponding to the range switch 63 setting are directly over the two detectors 14 and 15 then the processor 40 signals the motor 51 to stop.
(c) Variable gain amplifiers 22 and 23 are switched to their maximum gain. The sample and hold units 26 and 27 are set to continually pass the signals from amplifiers 22 and 23 to the switch inputs, respectively at 28 and 29. The electronic switch 30 alternates so that the line 31 is connected successively to input line 28 and then 29. ADC 33 continually monitors the voltage at line 31 until the voltage on both lines 28 and 29 has reached a constant level thereby indicating that all capacitances in the amplifiers have reached a quiescent level.
(d) After the quiescent level is reached, electronic switch 30 is set to pass the signal on line 28. The processor 40 continues to monitor the output 34 of ADC 33 until the signal has exceeded a predetermined threshold, thereby indicating that detectors 14 and 15 are receiving an exposure of X-rays.
(e) ADC 33 continues to monitor line 28. If the voltage on line 28 rises to a value close to the system power supply then the amplifiers 22 and 23 are close to saturation and liable to give erroneous results. In this case, the processor 40 reduces the gain of the amplifiers 22 and 23 by sending appropriate signals to the gain controller 47. If the voltage on line 28 continues to rise to values near saturation, processor 40 will continue to reduce the gain of amplifiers 22 and 23. If the voltage on line 28 begins to fall, thereby indicating the end of the exposure, or if the amplifiers 22 and 23 are near saturation at the lowest gain setting, or if 300 milliseconds (the maximum calculation loop time of the processor) has elapsed since the beginning of the exposure, then the processor 40 will activate the sample and hold circuits 26 and 27 and the electronic switch 30 so that ADC 33 will measure the sampled signal from both sources 28 and 29. These measurements will be proportional to the energy received by detectors 14 and 15, respectively.
(f) The motor 51 is turned on and position sensor 53 is monitored by the processor 40. The motor is turned off when the position of the filter wheel is such that a thick absorber 13 corresponding to the selected range is over detector 15 and a thin absorber 12 is over detector 14. These absorbers correspond to the range switch 63 setting.
(g) The voltage on lines 28 and 29 are monitored as in step (c) until a quiescent level has been reached.
(h) The quiescent voltage levels on both lines 28 and 29 are offset errors or drifts and are respectively measured by ADC 33.
(i) The offset errors recorded in step (h) are subtracted from the corresponding measured signals recorded in step (e) to provide a corrected and accurate measure of the X-ray energy received by each detector 14 and 15. The processor then divides the corrected signal from detector 15 by the corrected signal from detector 14, and then computes the logarithm of said division. This computation completes the calibration of the instrument and the user is informed by display 66 which displays the letters "CAL".
(j) The signal on line 28 is monitored as in step (d) by ADC 33 until said predetermined threshold is exceeded thereby indicating that the user has made a second exposure of X-rays.
(k) Processor 40 then sets controller 47 to give the gain in amplifiers 22 and 23 that did not cause saturation in the course of step (e) above. ADC 33 continues to monitor the voltage on line 28 until said voltage beings to fall or until it reaches the same maximum value as was reached in the previous exposure in step (e), whereupon processor 40 will activate the sample and hold 26 and 27 and electronic switch 30 so that the ADC 33 will measure the sampled signal on both lines 28 and 29. These measurements respectively correspond to the energy received by detectors 14 and 15. Detector 15 will receive less energy than detector 14 since absorber 13 is thicker than absorber 12.
(l) Offset errors recorded in step (h) are subtracted from the corresponding measured signals recorded in step (k) above. As in step (i) above, the corrected signals are divided and the logarithm of the quotient of said division is computed.
(m) The logarithm computed in step (i) is subtracted from the logarithm computed in step (l). The difference between logarithms (called DL) corrects for any gain differences in the detectors or associated electronics, or any nonuniformities in the radiation striking the detectors.
(n) The computed value DL from step (m) is used in the following formula to compute the kilovoltage of the radiation source, although an equivalent calibration or a table look-up procedure may alternatively be used. ##EQU1## where the parameters K 1 , K 2 , K 3 and K 4 are empirically determined. Values K 1 and K 2 are slightly adjusted for each set of filters. These adjustments are necessary due to the difficulty in obtaining absorbers with a tightly controlled thickness tolerance. Said adjusted values are read into the processor from ADC 55 connected to several potentiometers 54. The potentiometers 54 are set during initial factory calibration of the present invention.
(o) The KV computation with filter thickness corrections is transmitted by means of display interface 58 to the front panel display 59. The program then branches back to step (a) above so that the sequence can be repeated.
In FIGS. 3A and 3B, the details of the mechanical design of the detector box 60 of the present invention are shown. Radiation striking the detector box first passes through a pre-collimator 100 which consists of a lead sheet with two holes 101 and 102 so that X-rays may strike the detectors. Holes 101 and 102 are smaller than the absorber disk diameter. Absorbers 12 and 13 are mounted on the filter wheel 52 and are located between the pre-collimator 100 and lead post-collimators 103 and 104. The holes 105 and 106 on post-collimators 103 and 104 are nominally the same diameter as the active area of the detectors 15 and 16. Post-collimators 103 and 104 along with lead shields 107 and 108 completely surround detectors 15 and 16 to prevent stray scattered radiation from being detected. Sensitive amplifiers 71 and 72 having low offset current are also enclosed in post-collimators 103 and 104. Additional electronic components are mounted on printed circuit board 112.
In FIG. 3B, three sets of light emitting diodes (LED) 109 and photo-transistors 110 mounted at the edge of filter wheel 52 are shown. Said LEDs illuminate the top of filter wheel 52 while phototransistors 110 detect the LED energy only if the filter wheel 52 is in a position such that small position encoding holes 111 in filter wheel 52 are directly between the LED 109 and associated phototransistor 110. The position encoding holes 111 and said sets of LEDs and phototransistors comprise the filter wheel position sensor 53 shown in FIG. 1.
Referring now to FIG. 4, a detailed schematic of the electronic circuitry in the detector box 60 is shown. Detectors 15 and 16 are preferably type number PV-444A manufactured by EG&G Corporation, and are respectively connected to amplifiers 71 and 72, which are preferably type number AD515JH. Feedback components R1 and C1 connected to amplifier 71 give rise to an integrating time constant of 0.25 seconds. The output of amplifier 71 is AC coupled by capacitor C3 to a unity gain amplifier comprised of amplifier 73, resistors R3 and R5, and offset trim potentiometer R7. In the preferred embodiment, capacitor C3 and resistor R3 provide a time constant of approximately one second. Collectively, amplifiers 71 and 73 along with components C1, C3, R1, R3, R5, and R7 comprise the AC coupled integrating preamplifier 18 shown in FIG. 1. Similarly amplifiers 72 and 74 along with components C2, C3, R2, R4, R6, and R8 comprise preamp 19 shown in FIG. 1.
The output 20 of preamplifier 18 is connected to four resistors R9, R11, R13, and R15 shown in FIG. 4. These four said resistors are respectively connected to four inputs of multiplexer 75. One resistor connected to the inputs of multiplexer 75 will be selected and connected by action of the multiplexer 75 to output line 87 in accordance with the status of control lines 82 and 83. Said selected resistor is thereby connected through line 87 to the negative input of amplifier 77. Feedback resistor R17 is connected from said negative input to the output of amplifier 77. Said selected input resistor and feedback resistor R17 together determine the gain of amplifier 77. Resistors R9, R11, R13, and R15 in conjunction with R17 are chosen to respectively provide gains of 300, 60, 12, and 2.4. Resistor R9 is selected when control lines 82 and 83 are both logic zero. Resistor R11 is selected when lines 82 and 83 are respectively logic one and logic zero. And resistor R15 is selected when lines 82 and 83 are both logic one. The status of control lines 82 and 83 are determined by gain controller 47 in FIG. 1. Collectively multiplexer 75, resistors R9, R11, R13, R15 and R17 along with amplifier 77, filter capacitor C5, and buffer amplifier 79 comprise the variable gain amplifier 22 shown in FIG. 1. Similarly, components 75, R10, R12, R14, R16, R18, C6, 78, and 80 comprise the variable gain amplifier 23. Note that both amplifiers 22 and 23 will provide the same nominal gain by action of control lines 82 and 83.
Returning to FIG. 4, multiplexer 81 is preferably type number CD4053 and contains three independent sections. A first section of multiplexer 81 has two inputs 89, and 91 and an output 28. Multiplexer 81 can cause either input 89 or 91 to be selected and connected to output 28 in accordance with the status of control line 84. When control line 84 is a logic one then the output 89 of amplifier 79 is selected and connected to output 28, thereby causing capacitor C7 to charge to the voltage value on line 89. If control line 84 is changed to a logic zero then the input is connected to output line 28. Input 91 is left unconnected so that capacitor C7 cannot discharge and will thereby hold the voltage value that was on line 89 just prior to the transition of the control line 84 from logic one to logic zero. Collectively, capacitor C7 and said first section of multiplexer 81 comprise the sample and hold circuit 26 shown on FIG. 1.
In a similar fashion sample and hold circuit 27 is comprised of capacitor C8 in conjunction with a second section of multiplexer 81 with input lines 90 and 92, output line 29 and control line 84.
A third section of multiplexer 81 has inputs 28 and 29, respectively, connected to the outputs of the first and second sections of multiplexer 81. One of the inputs 28 or 29 can be selected and connected to output 31 by multiplexer 81 in accordance with the status of control line 85. The third section of multiplexer 81 comprises the electronic switch 30 shown in FIG. 1.
While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the accompanying claims. | An improved method and apparatus for accurately measuring the applied kilovoltage (KV) of an X-ray source over a wide dynamic operating range. A pair of radiation detectors are mounted beneath a rotatable disc having disposed thereon a plurality of metallic absorbers. To measure applied KV, two exposures are required. In the first exposure, called the "calibration" exposure, the detectors are filtered by two absorbers of equal thickness (t 1 ) and the detected X-ray intensities are measured, processed, and stored in a digital memory. In the second X-ray exposure, referred to the "measure" exposure, the filter wheel is automatically advanced so that one detector is filtered by an absorber of thickness (t 1 ) and the second detector is filtered by an absorber of thickness (t 2 ). The detected X-rays are gain measured and the ratio of the signals calculated to determine the relative penetrating energy. The data from the second measurement is then modified in accordance with the data from the calibration exposure before applied KV is derived to correct for gain differences in the detectors and associated electronics as well as for any nonuniformities in the radiation striking the detectors. Offset errors and drifts in the electronics are also automatically compensated for. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The invention relates to wax imitation candles and more particularly to an imitation candle resistant to cracking at low temperatures.
[0003] 2. Description of the Problem
[0004] Many people find candle light pleasant. The flickering of light and movement of shadows across a floor or on a nearby wall can be almost hypnotically soothing. As a result, candles have remained popular for generations since the invention of more practical electrical lighting, especially for decorative and mood setting purposes.
[0005] Consequently, numerous manufacturers have attempted to meet a demand for a candle like luminary using electrical illumination. A now popular imitation candle is taught in International Publication Number WO 03/016783 A1. This imitation candle uses an internal LED as a light source within a solid appearing body. While a classical image of a candle is of a long, thin, tapering rod, which stands upright in a candle stick and which leaves its flame exposed as it burns down, this imitation candle comes as a relatively short to circumference block or cylinder which is self supporting. Such candles commonly leave the outer wall of the candle intact as the candlewick burns down. When this happens, the candle flame is no longer directly visible when viewed from the side. This results in a diffuse, flickering glow visible through the paraffin wall of the candle, which is imitated by the external shape of the imitation candle.
[0006] While the imitation candle of WO 03/016783 appears to be a solid body to users it is in fact hollow. This provides space for the installation of batteries, the LED, LED excitation circuitry and possibly light directing internal components. In addition, the contour of the void's internal surface may be chosen for light transmission issues. While the imitation candle can readily be made in plastic, fabricating it in more realistic wax has presented particular problems.
[0007] Wax is highly susceptible to compressive and tensile stress. Waxes also tend to have high coefficients of thermal expansion. Differential heating and cooling of sections of a cast wax body introduces stress. Stress tends to be focused along sharp corners and edges of a wax body. Stress can occur during manufacturing and shipping of the wax shell imitation candles when the imitation candles are subjected to rapid cooling or great temperature extremes, respectively. The cavity adds the problem of internal edges, as well as reducing the strength of the body compared to a solid wax body. In addition, the insert on which battery, excitation circuitry and the LED are mounted will typically be constructed by plastic with the wax body being formed in part on the insert body. Wax will typically have a higher coefficient of expansion than the plastic does, which results in additional stress as temperature of the body decreases and contributes further to the problems of the inherent weakness of wax.
[0008] Wax bodies, such as candles, are formed by a process of casting. Where it is desired to incorporate a plastic module in the wax body the plastic module may be fixed in position in a mold and hot wax poured around the module, adding wax as earlier poured wax cools and shrinks, until all voids around the module are filled. Alternatively, a wax shell can be formed that produces the outer visible surfaces of the candle while leaving a space for the module. After the shell is produced a second pour is done to secure the module in position. The amount of wax in the second pour is less than in the first, with the attendant advantages of quicker cooling and faster production speeds. While true, solid wax candles have reasonable durability to withstand cold temperature induced stress, wax bodies made by either of the foregoing casting techniques have proven highly susceptible to cracking. Thin sections of the casting adjacent the module cool more rapidly than thicker sections. Leading edges of the imitation candle also cool rapidly. These sections of rapid cooling result in differential rates of contraction, which can easily result in formation of a crack to relieve stress. Once such a crack propagates into a thicker section of the body it can become a focal point for other stresses and can extend to encircle the imitation candle body.
SUMMARY OF THE INVENTION
[0009] According to the invention there is provided an imitation candle. The imitation candle has a wax shell having a central cavity defined by an interior surface. A artificial lighting module, which tends to exhibit a different thermal coefficient of expansion than the wax, is positioned in the central cavity. A bonding layer between a portion of the module and the interior surface of the wax shell retains the module in the shell. The bonding layer leaves a gap between the insert and the interior surface near any exterior edges of the wax shell. The gap is preferably filled with air.
[0010] Additional effects, features and advantages will be apparent in the written description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0012] FIGS. 1 and 2 are perspective views from different angles of a wax shell and artificial illumination source for insertion thereto.
[0013] FIGS. 3A and 3B are cross sectional views of wax shell imitation candles constructed in accordance with each of two preferred embodiments of the invention.
[0014] FIG. 4-7 depict steps in a process for fabricating the wax shell imitation candle of FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring now to FIGS. 1 and 2 a shell 10 and an insert or illumination module 12 which includes circuitry, batteries and a light emitting diode for insertion into the shell are shown from above and below. Shell 10 is a generally squat, cylindrical body, with dimensions common to free standing, thick walled candles. An upper surface 22 of shell 10 is depressed into the interior of the shell to simulate a previously burned candle the center of which is partially melted and consumed. Insert 12 fits into and is retained within cavity 14 defined by an interior surface 15 of shell 10 . Cavity 14 is open along a bottom surface of shell 10 and is slightly oversized, as described below, to admit insert 12 . Shell 10 is preferably a cast wax body. Insert 12 has an exterior casing 18 made enclosing the battery, circuitry and an LED enclosed in an upper surface 16 of the insert 12 . Insert 12 is introduced to cavity 14 lead by upper surface 16 . The wax material of shell 10 and the plastic material of casing 18 exhibit substantially different coefficients of thermal expansion. The present invention concerns mating of the interior surface of shell 10 and casing 18 of insert 12 to inhibit cracking of the wax of the shell.
[0016] Referring to FIGS. 3A and 3B some of the features of the invention as incorporated into each of two preferred embodiment of the invention may be seen to advantage. The central depression in upper surface 22 begins spaced inwardly from a rounded circumferential exterior edge 27 with a shallow downwardly slanted ledge 26 , which terminates moving toward the vertical center axis of shell 10 in a rounded shoulder 24 where the upper surface drops to a central depression defined by a second shoulder 25 . Insert 12 is illustrated fitted into cavity 14 from the bottom of shell 10 . Cavity 14 is defined by an interior surface 15 which, in a fashion similar to the central depression in the upper surface 22 , has rounded transitions between portions of the surface which exhibit substantial intersecting angles vis-a-vis one another. Rounded transition 23 is characteristic forming a boundary between a cylindrically shaped, vertically oriented section of interior surface 15 and a horizontally oriented disk like section at the top of cavity 14 .
[0017] Insert 12 is undersized compared to the cavity 14 in which it is to be retained. Bonding between a plastic insert casing 18 is provided by bonding layer 20 which lines the upper portion of cavity 14 between casing 18 and interior surface 15 . As described below, bonding layer 20 is formed by a second pouring of a small quantity of molten wax into an inverted, but already cooled and hardened shell 10 . Bonding layer 20 is shaped by fitting insert 12 into cavity 14 while the second poured wax is still molten. Bonding layer 20 does not line all of interior surface 15 in the preferred embodiment, but only enough to cover casing 18 around LED 16 and about the top half of the main body of insert 12 . An air gap 30 surrounds the bottom half of insert 14 spacing the insert from interior surface 15 . The top 34 of illumination module 14 abuts an upper horizontal face 34 of interior surface 15 , displacing molten wax and positioning the illumination module vertically. Horizontal positioning of illumination module may be achieved by careful reference to the spacing between casing 18 and interior surface 15 and by the careful, mutually parallel orientation of the elements. The bottom surface of insert 12 is slightly recessed (2.5 mm) from the surrounding bottom surface of shell 10 allowing accurate determination disposition of the insert in cavity 14 .
[0018] While use of a bonding layer 20 is preferred due to the assurance of a good fit between the bonding layer and insert 12 , it is possible to substitute a molded or shaped shoulder 60 which is formed as part of interior surface 15 defining cavity 14 . As seen in FIG. 3B shoulder 60 is part of shell 12 and slants inwardly into cavity 14 partway into the cavity from the bottom surface of shell 10 . Construction of shell 10 to incorporate such a circumferential shoulder is easily done by modification of the bit used to shape cavity 14 or form 42 . It is important that a gap be left between the body of insert 12 and interior surface 15 in the lower part of cavity 14 . This saves processing steps. However, the difficulty in this technique is that extremely close tolerances in dimensional matching between the insert 12 and the shell 10 are required to avoid introducing stress on introducing the insert to cavity 14 . It may be possible to time the introduction to a point while the wax of shell 10 is still slightly soft.
[0019] FIGS. 4 through 7 help illustrate a process for fabricating the imitation candle of the present invention. The first step of the process is to pour molten wax 11 into a mold 40 giving the body of wax which cools to form shell 10 its exterior shape. Mold 40 should be slightly taller then the desired eventual size of shell 10 to allow trimming of the cooled body to the desired size. Cavity 14 may be formed in one of two ways. In one process, a form 42 is held in the mold 40 to leave cavity 14 upon withdrawal from the hardened shell 10 . Alternatively, no form is used and the mold 40 is substantially filled with wax on the first pouring. In a preferred embodiment mold 40 is 111 mm deep allowing trimming of shell 10 to a desired height of 105 mm.
[0020] After pouring of the wax for shell 12 the wax is allowed to cool. Where no form is used the wax is allowed to cool until the wall thickness is at least 10 mm. Where a form 42 is used the wax is allowed to cool until the entire shell 10 has hardened. A water bath may be used to expedite the cooling process. If no form was used a hole is formed into the cooling body from what will be become the bottom surface of the shell to the interior, still molten wax. The mold is partially inverted to allow the molten wax to be poured out and reclaimed. Removal of the central, molten wax speeds the cooling process and relieves stress on the walls of shell 10 . The shell continues cooling, again potentially placed in a water bath to quicken the process. Mold 40 is advantageously shaped to impress an upper surface central depression into shell 10 . Where, however, the mold did not incorporate such a shape, a bit contoured with the cross section of the upper surface may be used to shape the upper surface after withdrawal of the shell 10 from mold 40 .
[0021] The position of insert 12 is controlled by the depth of cavity 14 . An inner bit may be used trim the bottom of shell 10 and to machine cavity 40 where no interior form 42 is used, or where adjustment of the shape of a cavity left by a form is required. Shell 10 should be properly fixtured during shaping with a bit to insure a uniform core depth and candle height.
[0022] With the shell 10 fully hardened and the shape of cavity 14 finalized, shell 10 is reinverted and a second pour 46 of a small quantity of molten wax is made into the top of cavity 14 . By the term “small” it is meant that the amount of wax in the second pour is a small percentage of the quantity of wax in the first pour. Where the depth of cavity 14 is 86 mm, the pour will leave the upper 58 mm empty before insertion of the insert 12 . The formulation of the wax may be the same for both pours. With the second pour 46 still molten, insert 12 is lowered into cavity 14 of the inverted shell 10 , displacing molten wax of the second pour 46 upwardly around the insert along the interior surface 15 of the cavity to form a bonding layer 20 . Insert 12 is pressed as far as possible into shell 10 , until the casing around upper surface 16 hits the top surface of the interior surface 15 . An air gap of about 30 mm extends upwardly from the bottom of shell 10 into cavity 14 around insert 12 . This helps prevent cracking.
[0023] The invention impedes the genesis and spread of cracks in the wax shell of a two component imitation candle. The assembly method for embedding insert 12 moves the point of maximum stress to a position where the stress is more readily tolerated. This is achieved by forming a gap between the insert and thin walled sections of the wax starting from a leading edge of the wax (e.g. the bottom edges of the shell). The gap can be air, or it can be filled with substances which offer insubstantial resistance to contraction of the wax as it cools. Leaving a gap between the bottom edge of the shell moves the point of maximum stress to an area of the shell where the gap ends and the bonding layer begins. This places the point of maximum stress away from any corners or edges. Cooling of the shell is also retarded here due to the greater local thermal mass, allowing more time for internal stress relief. The invention also achieves reduced concentration of stress by maintaining a maximum degree of uniformity in wax wall thickness and eliminating sharp corners.
[0024] While the invention is shown in only two of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit and scope of the invention. | An imitation candle having an exterior wax shell and an interior illumination source is structured to reduce cracking of the exterior wax shell by incorporating a bonding layer into a central cavity in the shell between the interior illumination source and the wax shell. The bonding layer terminates well spaced from terminal edges of the shell to transfer stress between the illumination source and the shell caused by differing coefficients of thermal expansion to points removed from edges of the shell to retard crack genesis. | 5 |
BACKGROUND OF THE INVENTION
This invention relates generally to a bounce crimper for texturizing a multi-filament yarn of synthetic resinous material. More particularly, this invention concerns an annularly segmented cylindrical can adapted to receive texturized yarn from a bounce crimping device.
Bounce crimping apparatus has been effectively used to texturize a multi-filament yarn of synthetic resinous material. See, for example, U.S. Pat. No. 3,887,971 and the other patents cited therein. One particular advantage of such apparatus is the high yarn production rates which are obtained with its use.
In the crimping section of the apparatus, a heated compressible fluid such as steam heats the individual filaments and accelerates the yarn in its longitudinal direction. Typically, the heated compressible fluid is itself accelerated by passing through a restricted orifice so that a high velocity jet is obtained. The jet then drives the yarn and causes acceleration thereof toward a foraminous surface extending across a channel.
The yarn is hurled against the foraminous surface causing individual filaments to be axially compressed and laterally crimped. The yarn, now texturized, rebounds from the screen and passes out of a lateral yarn outlet while most of the compressible fluid goes through the foraminous surface and is discharged from a fluid outlet.
The texturized yarn is cooled prior to being subjected to longitudinal tension to enhance retention of the crimps induced by the bounce crimper assembly. If desired, it also may be subjected to a heat setting treatment in a tensionless state to further enhance crimp performance. Conventionally, the yarn is then collected by a suitable winding mechanism.
One type of device often used to store the yarn in a tensionless state while it is being set to fix the crimp is a J-box into which the highly texturized yarn falls after its passage through the bounce crimping apparatus, prior to collection by the winding mechanism. The use of a J-box, however, requires that the average yarn input and output rates be equal, and this in turn limits the crimping speed to the maximum practical operating speed of the particular winder that is available.
The J-box storage unit also provides a limit on the time of yarn storage in the tensionless state, assuming of course that the input and withdrawal rates are constant. This limit is related to the dimensions of the J-box and is not subject to easy adjustment during operation of the equipment. Hence, changes in heat setting time are not readily achievable independently of the rate at which the yarn moves through the crimping head.
There are other environments where continuous lengths of textile materials need to be stored, and in at least some of these, cans are sometimes used to receive the material. See for example, U.S. Pat. No. 2,924,001. And, in the case of slivers issuing from carding machines, steps have been taken to control the deposit of the slivers so that they will be disposed in the sliver cans in a predetermined arrangement which facilitates endwise withdrawal of the sliver as it is being sent to a subsequent processing step. See for example, the description of such a system at page 235 of American Cotton Handbook, 2nd edition, by Gilbert R. Merrill et al, published in 1949 by Textile Book Publishers, Inc. of New York, New York.
However, the techniques employed in these other systems are not directly applicable to the handling of bounced crimped yarns that have loose, crimped, filaments projecting from their surfaces. These filaments are the source of a marked tendency toward entanglement of different yarn portions. Yarn-to-yarn entanglement often requires cutting of the yarn to remove the entanglement followed by splicing of the yarn to attain substantial continuity of its length. Accordingly, the entangled yarn which is excised must be scrapped causing economic waste.
Accordingly, a need continues to exist for an improved system for collecting texturized yarn of synthetic resinous material from a bounce crimping apparatus at high speed without substantial entanglement.
SUMMARY OF THE INVENTION
A system suitable for high speed collection of a texturized yarn of synthetic resinous material from a bounce crimping device, which minimizes entanglement and facilitates handling of the yarn while permitting increased production rates, preferably includes a generally cylindrical container having a plurality of concentric annular walls. The concentric walls define a plurality of generally annular chambers into which the texturized multi-filament yarn is sequentially deposited. Radial spacing between adjacent concentric walls is selected as a function of the denier of the multi-filament yarn being collected with low denier yarns requiring narrower wall spacing than high denier yarns. The container rotates so as to provide controlled toppling of accumulated yarn.
The annularly segmented container is positioned below the yarn outlet of the crimping section such that texturized multi-filament yarn is first deposited in the radially innermost annular chamber. As the container is rotated by suitable rotating means, successive layers of yarn are deposited in the innermost annular chamber to fill that chamber. Then the container is indexed by suitable indexing means to allow the texturized yarn to begin accumulating in the next radially outwardly adjacent annular chamber. The indexing and filling is continued until each annular chamber of the container is filled at which time the container is removed and replaced with an empty container.
During the deposit of layers of yarn in the annular chambers, the rotational speed of the container is controlled so that the small vertical accumulations of yarn that occur as yarn increments fall freely into the container tend to topple in a direction opposite to the direction of container rotation. By exercising careful control over the container speed, the thickness of the yarn layers can be kept at desired values and deleterious tangling of the yarn may be minimized.
In removing the texturized multi-filament yarn from the container, a lid is placed over the container and the yarn is removed in an inverse fashion. More particularly, the end of the yarn which was last deposited in the outer annular chamber is removed first. The multi-filament yarn is then withdrawn through a guide positioned above the axis of the container and the edge of the lid scrapes any loops and tangles from the texturized yarn during withdrawal. Since the container is loaded from the radially innermost to the radially outermost chamber, yarn from the radially innermost chamber will be dragged across two or more walls as well as the lid edge during its removal. Loops and the like removed as the yarn is drawn over the top of an annular wall will not become entangled with yarn in other annular chambers because these chambers will already have been emptied. Thus, the removed yarn will be essentially free of undesirable tangles.
The container will receive the yarn at whatever speed the yarn is delivered to it by the crimper head. There is no limit to the time of storage of the yarn in the container, so that crimp setting treatments of any desired length may be carried out. And, the rate of withdrawal of the yarn from the container may be independent of the rate of deposit. If desired, more than one winder may be employed to handle the output of a single high speed crimping unit.
BRIEF DESCRIPTION OF THE DRAWINGS
Many objects and advantages of the present invention will be apparent to those skilled in the art when this specification is read in conjunction with the attached drawings wherein like reference numerals have been applied to like elements and wherein:
FIG. 1 is a perspective view of a bounce crimping device having a container constructed in accordance with the present invention;
FIG. 2 is a cross-sectional view depicting details of a bounce crimper;
FIG. 3 is a perspective view of the container along with its rotating and advancing mechanisms;
FIG. 4 is a view in partial cross section taken along the line 4--4 of FIG. 5; and
FIG. 5 is a perspective view illustrating withdrawl of fibrous material from the container.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A texturizing apparatus 20 (see FIG. 1) includes a frame 22 having a first pair of rolls 24, 25 around which the incoming undrawn multi-filament yarn is wrapped a plurality of times. The multi-filament yarn includes many essentially continuous filaments of a synthetic resinous material, such as polypropylene. From the first set of rolls 24, 25 the multi-filament yarn advances to a second set of rolls 26, 27 which rotate at a higher surface speed than that of the first set of rolls 24, 25. With the second set of rolls rotating at the higher surface speed, the yarn is drawn between the two sets of rolls to longitudinally elongate the individual yarn filaments. The drawn multi-filament yarn may then enter a bounce crimping section or device 32.
The bounce crimping device 32 (see FIG. 2) includes a body or housing portion 34 having a longitudinal channel or bore 36 extending therethrough. The upper end of the bore 36 has an enlarged end portion 38 having an internally threaded section 40 that receives an externally threaded backing plug 42.
The backing plug 42 retains an orifice plug 43 in the bore portion 38 such that mating frustoconical surfaces 45, 47 longitudinally position the orifice plug 43. The orifice plug 43 includes a frustoconical surface portion 44 on its distal end. The frustoconical surface 44 cooperates with a second frustoconical surface 46 positioned between the bore 36 and the enlarged end portion 38 thereof to define an annular orifice. The orifice provides fluid communication between the enlarged end portion 38 and the longitudinal bore 36.
The backing plug 42 and the orifice plug 43 each include a longitudinal channel 48 which extends therethrough from the top surface 50 of the backing plug 42 to the distal end of the orifice plug 43 downstream of the annular orifice to define a yarn inlet orifice. The channel 48 provides a passageway to the bore 36 for untexturized yarn of the synthetic resinous material which is to be texturized.
The body 34 has a generally cylindrical end portion 52 within which the backing plug 42 is threadably received. The cylindrical portion 52 has a generally circular cross section, extends from a location below the orifice, and is provided with a plurality of radially extending ports 54. The ports 54 communicate with the enlarged end portion 38 of the longitudinal bore upstream of the frustoconical surface 46.
An annular manifold block 56 is mounted circumferentially around the cylindrical portion 52 and includes three annular recesses 58, 60, 62 in the inner surface. Each recess 58, 60, 62 faced the cylindrical end portion 52 and extends radially outwardly therefrom. The upper and lower recesses 58, 62 are adjacent to corresponding ends of the manifold block 56 and each is adapted to receive a suitable conventional O-ring seal 64. Each seal 64 is effective to provide a pressure seal between the ends of the manifold block 56 and the cylindrical end portion 52 so that the recess 60 is isolated.
The central recess 60 communicates with a conduit (not shown) which may be connected to a suitable conventional source of heated pressurized gas (not shown) such as steam.
At the lower end of the body portion 34 is an exhaust housing 70 which defines a fluid outlet. The exhaust housing includes a longitudinal extending bore 72 in general coaxial alignment with the bore 36 of the body portion 34. Positioned between the body portion 34 and the exhaust portion 70 and transversely of the channel is a suitable conventional foraminous surface 74, such as a screen. A lateral yarn discharge opening 76 communicates with the bore 36 at the position of the foraminous sheet 74 and is aligned substantially perpendicularly with respect to the bore 36. The discharge opening 76 communicates with one end 78 of a tubular conduit means 80.
A second end 82 of the tubular conduit means 80 has a restrictor assembly 84 which controls the discharge of texturized multi-filament yarn from the conduit means 80. The restrictor assembly 84 may, for example, include a resilient member which protrudes into the internal passage of the conduit means 80 so as to impede the progress of the yarn and thereby assure a reasonable level of compaction thereof. The yarn then passes out of a second end 85 of the restrictor assembly 84.
Texturized yarn from the bounce crimper device 32 is discharged from restrictor assembly 84 and allowed to drop vertically downwardly into a novel rotating container or can 92 (see FIG. 3). The container 92 includes a plurality of concentric annular walls 94, 96, 98 and a coaxially disposed rod 100.
As seen in FIG. 4, the annular walls 94, 96, 98 extend vertically upwardly from a substantially planar base 102 to which the central rod 100 is also connected. The walls 94, 96, 98 and essentially coextensive and the rod 100 extends beyond the upper edges of the walls. The rod 100 and the radially innermost wall 98 cooperate to define a first annular chamber 104. Similarly, the inner wall 98 and the middle wall 96 define a second annular chamber 106, and the middle wall 96 and the outer wall 94 define a third annular chamber 108. Each annular chamber 104, 106, 108 is adapted to receive the texturized yarn from the bounce crimper assembly 32.
While the container 92 is described with three annular walls, it will be apparent to those skilled in the art that any desired number of walls, with annular chambers therebetween, may be utilized.
In the texturizing apparatus, the container 92 is positioned coaxially on a rotary table 112 (see FIG. 3) that is mounted on a carriage 114. A suitable conventional rotary drive 110 engages the table 112 and rotates it at a uniform angular velocity.
The rotary drive 110 is also mounted on the carriage 114 and may, for example, consist of a small disc 111 driven by a suitable conventional motor 113 carried by the carriage 114. The disc 111 may frictionally engage the periphery of the rotary table 112 so as to impart rotation thereto.
The spacing between adjacent ones of the annular walls 94, 96, 98 and the speed of rotation of the scan 92 are selected so that a generally uniform layer of yarn is formed in one of the annular chambers 104, 106, 108 during each revolution of the can. As the yarn falls into a chamber, there will be a small, generally vertical, buildup or pile formation that has a tendency to topple over. It is desirable that the spacing between the side walls of the chamber be narrow enough to inhibit lateral, as opposed to circumferential, toppling. Moreover, with respect to the circumferential toppling, it is preferred that the rotation rate of the can be selected so as to promote forward toppling in the direction in which the yarn layer is being laid down in the chamber, that is in a direction opposite that of the container rotation.
Such controlled deposit of the crimped yarn minimizes layer-to-layer entanglement effects, and the yarn is particularly well positioned for subsequent removal in an orderly fashion and free from tangles. Although the spacings and speeds required are not highly critical for many operations, these factors should be kept in mind particularly when changes are being made in the yarn to be processed. Low denier yarn has been observed to make slenderer piles than high denier yarn, so that reductions in spacing and/or changes in speed may be required to preserve the desired toppling pattern after a shift to a low denier yarn.
In order to move the container 92 relative to the discharge of the bounce crimper assembly, an indexing mechanism may be provided. The indexing mechanism may include a bracket 116 (FIG. 3) attached to the frame and operable to receive a rotatable threaded shaft 118. The shaft 118 may be intermittently driven by a suitable conventional motor 120 attached to the frame or another stationary object.
In operation, the bounce crimped multi-filament yarn drops essentially vertically downwardly into the first annular chamber of the container 92. While the yarn drops into the first annular chamber 104, the container 92 is rotated by the rotary drive 110 (see FIG. 3) so that the texturized material can be laid in all circumferential portions of the chamber 104.
When the first annular chamber has been filled with texturized yarn, the carriage 114 is advanced by the indexing assembly to displace the axis of the rod 100 radially so that the texturized yarn begins to fill the second annular chamber 106. The indexing distance is essentially the radial distance between the middle of adjacent annular chambers. The container 92 continues to rotate so that the yarn accumulates in an essentially helical layer having a predetermined thickness from the bottom to the top of the chamber 106. When the second annular chamber 106 has been filled with texturized yarn, the indexing assembly is again actuated to reposition the container 92 relative to the texturizing apparatus so that the texturized yarn will then be deposited in the third annular chamber 108. Again, the container continuously rotates until the annular chamber is filled with texturized yarn.
It will be noted that the rate of rotation may be adjusted simultaneously with radial indexing in order to provide an appropriate tangential velocity.
When all annular chambers of the container 92 have been filled, the full container 92 is removed and the carriage 114 is repositioned by the index assembly to its initial location. A new container 92 is placed in material receiving position. The texturized multi-filament yarn may be severed so that there is no connection between successive containers. The yarn in the full container 92 may then be treated by heat setting or stored in the container or taken directly to another processing station.
At a new processing station, the texturized multi-filament yarn must be removed from the container 92. In this connection (see FIG. 5), a lid 122 is positioned over the projecting end portion of the rod 100. The rod 100 projects through the lid 122, is effective to radially position the lid with respect to the container 92 and has a protuberance 132 (FIG. 4) to hold the lid above the walls so that a space is provided for yarn passage.
Now, with the container 92 stationary, the severed end of the texturized material is passed through a suitable conventional guide 124 which may be located above the container. The guide 124 is preferably spaced above the container by a vertical distance at least as great as the diameter of the container 92 and preferably as high as possible. The need to reach the guide 124 for string-up purposes provides an effective upper limit. By placing the guide as high as is practical, the yarn can more readily rotate about the edge of the lid 122 to approximate the circumferential location from which yarn is being withdrawn and facilitate yarn removal.
As tension is applied to the multi-filament yarn being withdrawn from the container 92, the material is withdrawn and scraped over the peripheral edge of the lid 122 (see FIG. 4). In addition, the small clearance between the upper edge of the wall and the underside of the lid aids removal of yarn tangles. When the radially outermost chamber has been emptied, the next radially inward chamber 106 begins to empty, with the yarn being pulled between the upper edges of the two walls 94, 96 and the underside of the lid 122. The withdrawal process from the second annular chamber 106 continues until it too is empty, at which time the first annular chamber 104 begins to empty. With the first annular chamber 104, the fibers are drawn across the upper edge of three consecutive walls, each of which provides a scraping to remove tangles from the material.
Since the tangential velocity of the innermost chamber is less than the tangential velocity of outer chambers, it is expected that entanglement from toppling is more likely to occur there than at radially outer portions of the container. Accordingly, the entanglement of the radially innermost chambers is greater than the entanglement existing in the radially outermost chamber. Therefore, the additional scraping provided by additional walls provides a staged tangle-removing assembly which improves tangle removal.
It should now be apparent that there has been provided in accordance with the present invention a process and container for use in combination with bounce crimping apparatus which facilitate accumulation of texturized multi-filament yarn without entanglement and which permits the removal of the multi-filament yarn from the container with a minimal amount of entanglement in the resultant yarn. Moreover, it will be apparent to those skilled in the art that numerous modifications, variations, substitutions and equivalents may be made for features of the invention without departing from the spirit and scope thereof. Accordingly, it is expressly intended that all such modifications, variations, substitutions and equivalents which fall within the spirit and scope of the invention as defined in the appended claims be embraced thereby. | An annularly segmented generally cylindrical pick-up container is disclosed for use in combination with bounce crimping apparatus which texturizes a multi-filament yarn of synthetic resinous material. The container includes a plurality of annular baffles which divide the container into a corresponding plurality of substantially annular chambers. The container is rotated while a texturized multi-filament yarn of synthetic resinous material is deposited into the annular chambers. As one chamber becomes full, the rotational axis of the container is moved to a new position so that the texturized material will begin filling the next radially outwardly adjacent annular chamber. | 3 |
RELATED APPLICATIONS
This is a §371 of International Application No. PCT/JP2008/061501, with an international filing date of Jun. 18, 2008 (WO 2008/156195 A1, published Dec. 24, 2008), which is based on Japanese Patent Application Nos. 2007-163418, filed Jun. 21, 2007, and 2007-178097, filed Jul. 6, 2007, the subject matter of which is incorporated by reference.
TECHNICAL FIELD
This disclosure relates to a ferritic stainless steel sheet having a superior corrosion resistance against sulfuric acid. In addition, besides the above corrosion resistance, relates to a ferritic stainless steel sheet which has a low degree of rough surface at a bent part which is formed by a bending work performed at an angle of 90° or more and to a method for manufacturing the above ferritic stainless steel sheet.
BACKGROUND
Fossil fuels, such as petroleum and coal, contain sulfur (hereinafter represented by “S”). Hence, when a fossil fuel is combusted, S is oxidized, and sulfur oxides such as SO 2 are mixed in an exhaust gas. When the temperature of an exhaust gas decreases in a pipe, such as a gas duct, a chimney pipe, or an exhaust gas desulfurizer, fitted to an apparatus (such as an industrial boiler) in which a fossil fuel is combusted, this SO x gas reacts with moisture in the exhaust gas to form sulfuric acid and, as a result, dewdrops thereof are formed on an inner surface of the pipe. This sulfuric acid in the form of dewdrops enables corrosion (hereinafter referred to as “sulfate corrosion”) of the pipe to progress.
Various techniques to prevent the sulfate corrosion have been investigated and, for example, there has been used a technique in which a pipe for an exhaust gas is formed from low-alloy steel or a technique in which the temperature of an exhaust gas is controlled to 150° C. or more.
However, by the techniques described above, although the sulfate corrosion may be suppressed, it is difficult to stop the progression thereof.
In recent years, concomitant with an expansion of automobile market in Asia, iron steel has been increasingly in demand, and the amount of fossil fuels consumed in blast furnaces, heat treat furnaces, and the like of steel industry has also been increased. Hence, development of techniques to prevent the sulfate corrosion has become an urgent requirement in the steel industry. In addition, since gasoline contains S, the sulfate corrosion is also generated in pipes for exhaust gases emitted from automobile engines. Accordingly, exhaust gas pipes of automobiles also require a technique to prevent the sulfate corrosion. In addition, many of these pipes are subjected to a severe bending work.
Since high-temperature exhaust gases pass through exhaust gas pipes of blast furnaces, heat treat furnaces, and automobiles, low-alloy steel has not been used to prevent high-temperature oxidation, but ferritic stainless steel has been used in many cases. Hence, various techniques to improve the resistance against the sulfate corrosion (hereinafter referred to as “sulfate corrosion resistance”) of ferritic stainless steel have been studied.
For example, in Japanese Unexamined Patent Application Publication No. 56-146857, a technique has been disclosed in which acid resistance is improved by decreasing the S content of ferritic stainless steel to 0.005 mass percent or less. However, in Japanese Unexamined Patent Application Publication No. 56-146857, the acid resistance is investigated by dipping ferritic stainless steel in boiling hydrochloric acid, and the sulfate corrosion resistance has not been disclosed.
In Japanese Unexamined Patent Application Publication No. 7-188866, a technique has been disclosed in which, to suppress intergranular corrosion caused by nitric acid, the contents of C and N of ferritic stainless steel are decreased, and the contents of Mn, Ni, and B are also defined. However, according to the generation mechanism of intergranular corrosion caused by nitric acid, an environmental potential becomes positive due to the presence of nitric ions, and hence the breakage behavior of a passivation film of stainless steel and the stability of corrosion products are different from those caused by the sulfate corrosion. Accordingly, to apply the technique disclosed in Japanese Unexamined Patent Application Publication No. 7-188866 to prevent the sulfate corrosion, further study must be carried out.
To improve the formability of a ferritic stainless steel sheet, there has been investigated a technique in which the amounts of C and N are considerably decreased in a refining step of molten steel which is used as a raw material or a technique in which C and/or N is stabilized by the formation of carbides and/or nitrides by addition of Ti and/or Nb to molten steel. As a result, a ferritic stainless steel sheet having superior deep drawing characteristics to those of an austenite stainless steel sheet has been developed. However, according to a related ferritic stainless steel sheet having superior deep drawing characteristics, the formability by a deep drawing work, which is evaluated, for example, by a Lankford value (so-called r value), is improved.
In addition, to reduce the degree of rough surface (so-called “orange peel”) at a bent part formed by stretch forming, a technique has been investigated to improve a method for forming a ferritic stainless steel sheet into a predetermined shape (for example, see Japanese Unexamined Patent Application Publication No. 2005-139533). However, the rough surface at a bent part is not only generated by stretch forming but is also generated, for example, by a bending work, and research on a technique for reducing the degree of rough surface at a bent part by improving components of a ferritic stainless steel sheet and a manufacturing method therefor has not been sufficiently carried out.
The rough surface is a collective term including various surface defects, and in a ferritic stainless steel sheet, a rough surface, which is called “ridging,” is frequently generated. The ridging indicates a surface defect which is caused by the difference in deformation between individual textures which is generated when the textures are processed in a rolling direction generated by rolling. Although steel which suppresses the generation of ridging has been disclosed in many reports, even when the steel described above is used, a rough surface at a bent part may be apparently observed in some cases. Accordingly, it is believed that the generation mechanism of the rough surface at a bent part is different from that of the ridging, and hence measures suitable for the respective problems are separately required. In particular, when a bending work is performed at an angle of 90° or more, the rough surface is apparently generated.
Accordingly, it could be helpful to provide a ferritic stainless steel sheet and a method for manufacturing the same, the ferritic stainless steel sheet having a superior sulfate corrosion resistance even in a high-temperature atmosphere and further having a low degree of rough surface at a bent part formed by a bending work performed at an angle of 90° or more.
SUMMARY
We carried out intensive research on the generation mechanism of sulfate corrosion of ferritic stainless steel sheets. It has been understood that inclusions containing S (hereinafter referred to as “sulfur-containing inclusions”) function as initiation points of the sulfate corrosion. However, since the sulfur-containing inclusions are dissolved when brought into contact with sulfuric acid, the sulfur-containing inclusions are not frequently observed at portions at which the sulfate corrosion occurs. Accordingly, we focused on the sulfur-containing inclusions before the sulfate corrosion occurs and investigated the influence of the grain diameter of the sulfur-containing inclusions on the progression of the sulfate corrosion.
As a result, the following findings which are effective to prevent the sulfate corrosion were obtained. They are:
(a) the S content is decreased to suppress precipitation of the sulfur-containing inclusions; (b) fine NbC grains are dispersed and precipitated by maintaining the Nb content in an appropriate range, and the sulfur-containing inclusions (such as MnS) are made to adhere to the precipitated NbC grains so that the sulfur-containing inclusions are refined; and (c) a passivation film is modified by maintaining the Cu content in an appropriate range so as to suppress dissolution of base iron.
In addition, we investigated the mechanism in which the rough surface (different from the ridging) is generated at a bent part formed by performing a bending work on a ferritic stainless steel sheet. As a result, the relationship between the average grain diameter of ferrite crystal grains at a bent part and a rough-surface depth was discovered. That is, we found that as the average grain diameter of ferrite crystal grains at a bent part is decreased, the rough-surface depth at the bent part is decreased.
In addition, we found that when dislocation movement caused by a bending work is disturbed by dispersing fine NbC grains to generate work hardening at a bent part, the bent part is uniformly processed, and the degree of rough surface is reduced.
That is, we provide a ferritic stainless steel sheet comprising: a composition which contains 0.02 mass percent or less of C, 0.05 to 0.8 mass percent of Si, 0.5 mass percent or less of Mn, 0.04 mass percent or less of P, 0.010 mass percent or less of S, 0.10 mass percent or less of Al, 20 to 24 mass percent of Cr, 0.3 to 0.8 mass percent of Cu, 0.5 mass percent or less of Ni, 0.20 to 0.55 mass percent of Nb, 0.02 mass percent or less of N, and the balance being Fe and inevitable impurities; and a structure in which the maximum grain diameter of inclusions containing S is 5 μm or less.
The ferritic stainless steel sheet can include the composition described above, wherein the Ni content is 0.3 mass percent or less, and the Nb content is 0.20 to 0.50 mass percent.
The ferritic stainless steel sheet can include, in addition to the above composition, at least one selected from the group consisting of 0.005 to 0.5 mass percent of Ti, 0.5 mass percent or less of Zr, and 1.0 mass percent or less of Mo is contained.
In addition, the ferritic stainless steel sheet can include in the composition the content of C and the content of N, each being 0.001 to 0.02 mass percent, the average grain diameter of ferrite crystal grains is 30.0 μm or less, and the maximum grain diameter of precipitated NbC grains is 1 μM or less.
In addition, we provide a method for manufacturing a ferritic stainless steel sheet comprising: performing hot rolling of a slab or an ingot which contains 0.02 mass percent or less of C, 0.05 to 0.8 mass percent of Si, 0.5 mass percent or less of Mn, 0.04 mass percent or less of P, 0.010 mass percent or less of S, 0.10 mass percent or less of Al, 20 to 24 mass percent of Cr, 0.3 to 0.8 mass percent of Cu, 0.5 mass percent or less of Ni, 0.20 to 0.55 mass percent of Nb, 0.02 mass percent or less of N, and the balance being Fe and inevitable impurities at a finishing temperature of 700° C. to 950° C., performing cooling at an average cooling rate of 20° C./sec or more from the finishing temperature to a coiling temperature, and performing coiling at a coiling temperature of 600° C. or less.
In addition, in the method for manufacturing a ferritic stainless steel sheet, the finishing temperature is 700° C. to 900° C., and the coiling is performed at a coiling temperature of 570° C. or less.
In addition, in the method for manufacturing a ferritic stainless steel sheet, a hot-rolled steel sheet is annealed at 900° C. to 1,200° C., and after pickling and cold rolling are performed, annealing is performed at an annealing temperature of less than 1,050° C.
In addition, in the method for manufacturing a ferritic stainless steel sheet, the hot-rolled steel sheet is annealed at 900° C. to 1,100° C., and after pickling and cold rolling are performed, annealing is performed at an annealing temperature of less than 900° C.
In addition, we provide a method for manufacturing a ferritic stainless steel sheet which comprises: performing hot rolling of a slab or an ingot which contains 0.001 to 0.02 mass percent of C, 0.05 to 0.3 mass percent of Si, 0.5 mass percent or less of Mn, 0.04 mass percent or less of P, 0.01 mass percent or less of S, 0.10 mass percent or less of Al, 20 to 24 mass percent of Cr, 0.3 to 0.8 mass percent of Cu, 0.5 mass percent or less of Ni, 0.20 to 0.55 mass percent of Nb, 0.001 to 0.02 mass percent of N, and the balance being Fe and inevitable impurities at a finishing temperature of 770° C. or less and a coiling temperature of 450° C. or less, and further performing cold rolling at a draft of 50% or more.
In addition, in the method for manufacturing a ferritic stainless steel sheet, cooling is performed from the finishing temperature to the coiling temperature at an average cooling rate of 20° C./sec or more.
A ferritic stainless steel sheet having a superior sulfate corrosion resistance even in a high-temperature atmosphere can thus be obtained.
In addition, a ferritic stainless steel sheet can be obtained which has a low degree of rough surface at a bent part formed by a bending work performed at an angle of 90° or more as well as the characteristics described above.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a graph showing the relationship between the grain diameter of sulfur-containing inclusions and the solution probability of base iron.
FIG. 2 is a schematic view showing a method for measuring a rough-surface depth at a bent part.
DETAILED DESCRIPTION
First, the reasons for specifying the components of a ferritic stainless steel sheet will be described.
C: 0.02 Mass Percent or Less
C is an element to increase the strength of a ferritic stainless steel sheet. To obtain the above effect, the content is preferably 0.001 mass percent or more. However, when the C content is more than 0.02 mass percent, since a ferritic stainless steel sheet is hardened, the press formability is degraded and, in addition, since C binds to Nb and N, which will be described later, to precipitate a coarse Nb carbonitride, the sulfate corrosion resistance is degraded. Hence, the C content is set to 0.02 mass percent or less. More preferably, the content is 0.015 mass percent or less.
In addition, in view of the degree of rough surface at a bent part, when the C content is less than 0.001 mass percent, precipitation of NbC grains which function as production nuclei of ferrite crystal grains is disturbed. On the other hand, when the C content is more than 0.02 mass percent, the formability and the corrosion resistance are not only degraded, but also NbC grains are coarsened. Hence, the C content is set in the range of 0.001 to 0.02 mass percent. More preferably, the content is 0.002 to 0.015 mass percent.
Si: 0.05 to 0.8 Mass Percent
Si is used as a deoxidizing agent in a steelmaking process for forming ferritic stainless steel. When the Si content is less than 0.05 mass percent, a sufficient deoxidizing effect cannot be obtained. Hence, a large amount of oxides is precipitated on a manufactured ferritic stainless steel sheet, and the weldability and the press formability are degraded. On the other hand, when the content is more than 0.8 mass percent, since a ferritic stainless steel sheet is hardened, the workability is degraded and, as a result, manufacturing of a ferritic stainless steel sheet may have some problems. Hence, the Si content is set in the range of 0.05 to 0.8 mass percent. More preferably, the content is 0.05 to 0.3 mass percent. Even more preferably, the content is 0.06 to 0.28 mass percent.
Mn: 0.5 Mass Percent
Mn is used as a deoxidizing agent in a steelmaking process for forming a ferritic stainless steel. To obtain the above effect, the content is preferably 0.01 mass percent or more. When the Mn content is more than 0.5 mass percent, the workability of a ferritic stainless steel sheet is degraded by solid solution strengthening. In addition, Mn binds to S which will be described later to facilitate precipitation of MnS and, as a result, the sulfate corrosion resistance is degraded. Hence, the Mn content is set to 0.5 mass percent or less. More preferably, the content is 0.3 mass percent or less.
P: 0.04 Mass Percent or Less
Although not responsible for the sulfate corrosion, P is an element to cause various types of corrosion, and hence the content thereof must be decreased. In particular, when the P content is more than 0.04 mass percent, besides the corrosion problem, due to segregation of P in crystal grain boundaries, the workability of a ferritic stainless steel sheet is degraded. As a result, manufacturing of a ferritic stainless steel sheet may have some problems. Hence, the P content is set to 0.04 mass percent or less. More preferably, the content is 0.03 mass percent or less.
S: 0.010 Mass Percent or Less
S is an element which binds to Mn or the like to generate sulfur-containing inclusions (such as MnS). Hence, a lower S content is more preferable. However, when the content is less than 0.0005 mass percent, desulfurization is difficult to perform and, as a result, the manufacturing load is increased. Accordingly, the content is preferably 0.0005 mass percent or more. When the sulfur-containing inclusions are in contact with sulfuric acid and are dissolved, hydrogen sulfide is generated and the pH locally decreases. A passivation film is not formed just under sulfur-containing inclusions precipitated on a surface of a ferritic stainless steel sheet, and even after the sulfur-containing inclusions are dissolved, no passivation film is formed since the pH is low. As a result, base iron is exposed to sulfuric acid and the sulfate corrosion progresses. When the S content is more than 0.010 mass percent, a large amount of the sulfur-containing inclusions is precipitated, so that the sulfate corrosion apparently occurs. Hence, the S content is set to 0.010 mass percent or less. More preferably, the content is 0.008 mass percent or less.
Al: 0.10 Mass Percent or Less
Al is used as a deoxidizing agent in a steelmaking process for forming a ferritic stainless steel. In addition, Al is added to precipitate N in steel in the form of AlN which is precipitated at a higher temperature than that at which a Nb carbonitride is precipitated, and thereby the N amount which binds to Nb is decreased, so that precipitation of a coarse Nb carbonitride is suppressed. Hence, Nb is precipitated in the form of fine NbC grains, and as a result, refining of ferrite crystal grains and suppression of coarsening of the sulfur-containing inclusions are effectively performed. In addition, since precipitated AlN grains are very fine, dislocation movement in a bending work is disturbed, and the work hardening of steel is facilitated, so that uniform deformation of a bent part can be effectively performed. To obtain the above effect, the content is preferably 0.005 mass percent or more. However, when the Al content is more than 0.10 mass percent, since Al-based non-metal inclusions are increased, surface defects, such as surface scratches, of a ferritic stainless steel sheet are caused thereby, and the workability is also degraded. Accordingly, the Al content is set to 0.10 mass percent or less. More preferably, the content is 0.08 mass percent or less.
Cr: 20 to 24 Mass Percent
Cr is an element to improve the sulfate corrosion resistance of a ferritic stainless steel sheet. When the Cr content is less than 20 mass percent, a sufficient sulfate corrosion resistance cannot be obtained. On the other hand, when the content is more than 24 mass percent, a σ phase is liable to be generated, and the press formability of a ferritic stainless steel sheet is degraded. Hence, the Cr content is set in the range of 20 to 24 mass percent. More preferably, the content is 20.5 to 23.0 mass percent.
Cu: 0.3 to 0.8 Mass Percent
After the sulfate corrosion occurs in a ferritic stainless steel sheet, Cu has a function to suppress the dissolution of base iron caused by an anode reaction. In addition, Cu also has a function to modify a passivation film present around each sulfur-containing inclusion. Cu present in the vicinity of sulfur-containing inclusions generates distortion in the crystal lattice of base iron. A passivation film formed on the distorted crystal lattice becomes denser than a passivation film formed on a normal crystal lattice. When the passivation film is modified as described above, the sulfate corrosion resistance of a ferritic stainless steel sheet is improved. When the Cu content is less than 0.3 mass percent, the above effect cannot be obtained. On the other hand, when the content is more than 0.8 mass percent, Cu is corroded by sulfuric acid, and from the corroded Cu, the sulfate corrosion of a ferritic stainless steel sheet progresses. In addition, since hot workability is degraded, manufacturing of a ferritic stainless steel sheet may have some problems. Hence, the Cu content is set in the range of 0.3 to 0.8 mass percent. More preferably, the content is 0.3 to 0.6 mass percent.
Ni: 0.5 Mass Percent or Less
Ni has a function to suppress an anode reaction caused by sulfuric acid and to maintain a passivation film even when the pH decreases. To obtain the above effect, the content is preferably 0.05 mass percent or more. However, when the Ni content is more than 0.5 mass percent, a ferritic stainless steel sheet is hardened, and the press formability is degraded. Hence, the Ni content is set to 0.5 mass percent or less. More preferably, the content is 0.3 mass percent or less. Even more preferably, the content is 0.2 mass percent or less.
Nb: 0.20 to 0.55 Mass Percent
Nb fixes C and N and has a function to prevent sensitization to corrosion by a Cr carbonitride. In addition, Nb also has a function to improve resistance to oxidation at a high temperature of a ferritic stainless steel sheet. Besides the effects described above, Nb is an important element that refines ferrite crystal grains by dispersing fine inclusions (that is, NbC). NbC grains function as product nuclei of recrystallization grains when a cold-rolled ferritic stainless steel sheet is annealed. Hence, when NbC grains are dispersed and precipitated, fine ferrite crystal grains are generated. Furthermore, NbC disturbs movement of grain boundaries in a generation process of ferrite crystal grains and disturbs the growth thereof. Hence, an effect of maintaining fine ferrite crystal grains can be obtained. That is, when fine NbC grains are dispersed, refining of ferrite crystal grains can be achieved. In addition, fine NbC grains dispersed in and precipitated on a ferritic stainless steel sheet disturbs dislocation movement caused by a bending work and causes work hardening at a bent part. As a result, since deformation by a bending work is sequentially moved to a region having a small deformation resistance, the bent part is uniformly processed, and the degree of rough surface is reduced. In addition, when fine NbC grains are dispersed and precipitated, sulfur-containing inclusions adhere thereto and are precipitated, and the grain diameter thereof is decreased. Even when a sulfur-containing inclusion having a decreased grain diameter is dissolved in sulfuric acid, since the pH is suppressed from decreasing, a solution therearound can maintain a lower limit pH or more at which stainless steel can form a passivation film, and as a result, stainless steel just below the sulfur-containing inclusion can be re-passivated immediately after the sulfur-containing inclusion is dissolved. Hence, dissolution of the S-containing inclusion does not initiate the corrosion, and hence the sulfate corrosion resistance is improved. When the Nb content is less than 0.20 mass percent, the above effect cannot be obtained. On the other hand, when the content is more than 0.55 mass percent, NbC grains are coarsened, and ferrite crystal grains and sulfur-containing inclusions are both coarsened. Hence, the Nb content is set in the range of 0.20 to 0.55 mass percent. More preferably, the content is 0.20 to 0.5 mass percent. Even more preferably, the content is 0.25 to 0.45 mass percent.
N: 0.02 Mass Percent or Less
N is solid-solved in a ferritic stainless steel sheet and has a function to improve the sulfate corrosion resistance. To obtain the above effect, the content is preferably 0.001 mass percent or more. However, when the content is excessive, as in the case of C, since precipitation of a coarse Nb carbonitride is facilitated, the sulfate corrosion resistance of a ferritic stainless steel sheet is degraded and, in addition, the degree of rough surface at a bent part is degraded. In particular, when the N content is more than 0.02 mass percent, besides the sulfate corrosion problem, the press formability of a ferritic stainless steel sheet is also degraded. Hence, the N content is set to 0.02 mass percent or less. More preferably, the content is 0.015 mass percent or less.
Furthermore, at least one selected from the group consisting of Ti, Zr, and Mo is preferably contained.
Ti: 0.005 to 0.5 Mass Percent
Since Ti binds to C and N to form a Ti carbonitride, C and N are fixed, and hence, Ti has a function to prevent sensitization to corrosion caused by a Cr carbonitride. Hence, by addition of Ti, the sulfate corrosion resistance can be further improved. When the Ti content is less than 0.005 mass percent, the above effect cannot be obtained. On the other hand, when the content is more than 0.5 mass percent, a ferritic stainless steel sheet is hardened, so that the press formability is degraded. Hence, when Ti is added, the Ti content is preferably in the range of 0.005 to 0.5 mass percent. More preferably, the content is 0.1 to 0.4 mass percent.
Zr: 0.5 Mass Percent or Less
As in the case of Ti, since Zr binds to C and N to form a Zr carbonitride, C and N are fixed and, hence, Zr has a function to prevent sensitization to corrosion caused by a Cr carbonitride. To obtain the above effect, the content is preferably 0.01 mass percent or more. Hence, by addition of Zr, the sulfate corrosion resistance can be further improved. However, when the Zr content is more than 0.5 mass percent, a large amount of Zr oxides (that is, ZrO 2 and the like) is generated, surface cleanness of a ferritic stainless steel sheet is degraded. Hence, when Zr is added, the Zr content is preferably 0.5 mass percent or less. More preferably, the content is 0.4 mass percent or less.
Mo: 1.0 Mass Percent or Less
Mo has a function to improve the sulfate corrosion resistance. To obtain the above effect, the content is preferably 0.1 mass percent or more. However, when the Mo content is more than 1.0 mass percent, the effect is saturated. That is, even when more than 1.0 mass percent of Mo is added, improvement in sulfate corrosion resistance corresponding to the addition amount cannot be expected, and on the other hand, since a large amount of expensive Mo is used, a manufacturing cost of a ferritic stainless steel sheet is increased. Hence, when Mo is added, the Mo content is preferably 1.0 mass percent or less. More preferably, the content is 0.8 mass percent or less.
In addition, since Mg has no contribution, a lower content is more preferable, and the content is preferably equivalent to or less than that of inevitable impurities.
The balance other than those components described above contains Fe and inevitable impurities.
Next, the structure of the ferritic stainless steel sheet will be described.
Maximum Grain Diameter of Sulfur-Containing Inclusions: 5 μm or Less
We manufactured ferritic stainless steel sheets having various components and investigated the relationship between the size of sulfur-containing inclusions and the progression of the sulfate corrosion. The investigation method and the investigation results will be described.
After ferritic stainless steel having components shown in Table 1 was formed by melting and further formed into a slab, hot rolling (finishing temperature: 800° C., coiling temperature: 450° C., and sheet thickness: 4 mm) was performed by heating to 1,170° C., so that a hot-rolled steel sheet was formed. An average cooling rate from finish rolling to coiling (that is, from 800° C. to 450° C.) was set to 20° C./sec.
The hot-rolled steel sheet thus obtained was annealed at 900° C. to 1,200° C. for 30 to 300 seconds and further processed by pickling. Next, after cold rolling was performed, annealing was performed at 970° C. for 30 to 300 seconds and was further processed by pickling, so that a ferritic stainless steel sheet (sheet thickness: 0.8 mm) was formed.
A test piece (width: 30 mm, and length: 50 mm) was cut out of the ferritic stainless steel sheet thus obtained, and two surfaces of the test piece were polished with #600 abrasive paper and were then observed using a scanning electron microscope (so-called SEM). The grain diameter of a Nb carbonitride was approximately several micrometers, and the grain diameter of a Nb carbide was approximately 1 μm. In addition, it was confirmed that sulfur-containing inclusions (such as MnS) adhere to peripheries of the Nb carbonitride and the Nb carbide and are precipitated. The grain diameters of all sulfur-containing inclusions in one arbitrary viewing field having a size of 10 mm square were measured. The grain diameter was defined as the maximum length of the longitudinal axis. The grain diameter of the maximum sulfur-containing inclusion among those thus measured was regarded as the maximum grain diameter.
Subsequently, after the test piece was immersed in sulfuric acid (concentration: 10 mass percent, and temperature: 50° C.) for 1 hour, the surface of the test piece was observed by a SEM. The Nb carbonitride and the Nb carbide observed before the immersion were dissolved together with the sulfur-containing inclusions, and at the positions thereof, dimples which were supposed to be formed by dissolution of base iron were generated. Although some inclusions remained on the test piece, S was not detected from the inclusions.
As described above, the relationship between the grain diameter of the sulfur-containing inclusions before the immersion in sulfuric acid and the solution probability of base iron by the immersion was investigated. The results are shown in FIG. 1 . In this case, the solubility probability is a value (=100×M/N) obtained by dividing a number M by a total number N of inclusions having a predetermined size before the immersion, the number M being the number of base-iron dissolution points which are confirmed at places at which the inclusions having a predetermined size are present before the immersion.
As apparent from FIG. 1 , when the maximum grain diameter of the sulfur-containing inclusions is 5 μm or less, the solution probability of the base iron is considerably decreased. This phenomenon indicates that when the maximum grain diameter of the sulfur-containing inclusions is 5 μm or less, the sulfate corrosion can be prevented. Hence, the maximum grain diameter of the sulfur-containing inclusions is set to 5 μm or less.
Next, the structure of the ferritic stainless steel sheet which has a low degree of rough surface at a bent part formed by a bending work will be described.
Average Grain Diameter of Ferrite Crystal Grains: 30.0 μm or Less
A rough-surface depth at a bent part formed by a bending work has the relationship with the average grain diameter of ferrite crystal grains. Since ferrite crystal grains are each formed to have a pancake like shape when receiving a tensile stress by a bending work, spaces are generated between adjacent ferrite crystal grains, so that the rough surface is generated. When bending work is performed to a predetermined level, the ratio of the major axis of a deformed pancake like ferrite crystal grain to the minor axis thereof is constant regardless of the size of ferrite crystal grains having an approximately spherical shape before a bending work is performed. The rough-surface depth is proportional to the minor axis of a ferrite crystal grain having a pancake like shape, and this minor axis is proportional to the size of the ferrite crystal grain before a bending work is performed. That is, as the average grain diameter of ferrite crystal grains is decreased, the rough-surface depth is decreased. When the average grain diameter of ferrite crystal grains is 30.0 μm or less, even if a bending work is performed at an angle of 90° or more, the degree of rough surface at a bent part can be reduced to a level at which no problems may occur. Hence, the average grain diameter of ferrite crystal grains is set to 30.0 μm or less. More preferably, the average grain diameter is 20.0 μm or less. By the way, the average grain diameter was obtained in accordance with ASTM E 112, and after the grain diameters of ferrite crystal grains in three arbitrary viewing fields were measured by an intercept method, the average value of the grain diameters was calculated.
Maximum Grain Diameter of NbC Grains: 1 μm or Less
As described above, when fine NbC grains are dispersed in a ferritic stainless steel sheet, since recrystallization of ferrite crystal grains is facilitated, and the growth thereof is disturbed, the ferrite crystal grains can be refined. When the maximum grain diameter of precipitated NbC grains is more than 1 μm, the above effect cannot be obtained. In addition, when NbC grains are coarsened, a stress is concentrated by a bending work and, as a result, local deformation is liable to occur. Accordingly, the maximum grain diameter of NbC grains is set to 1 μm or less. The grain diameter of the largest one among NbC inclusions observed in one arbitrary viewing field having a size of 10 mm square was measured. The maximum length of the long axis was regarded as the maximum grain diameter.
Hereinafter, one example of a preferable method for manufacturing the ferritic stainless steel sheet will be described.
After a ferritic stainless steel having predetermined components is formed by melting and further formed into a slab, hot rolling (finishing temperature: 700° C. to 950° C., more preferably 900° C. or less, and even more preferably 770° C. or less; coiling temperature: 600° C. or less, preferably 570° C. or less, and even more preferably 450° C. or less; and sheet thickness: 2.5 to 6 mm) is performed by heating to 1,100° C. to 1,200° C., so that a hot-rolled steel sheet is obtained. To prevent sulfur-containing inclusions and ferrite crystal grains from being coarsened from finish rolling to coiling, cooling from the finishing temperature to the coiling temperature is performed at an average cooling rate of 20° C./sec or more.
A cooling rate after the coiling is not particularly limited. However, since the toughness of the hot-rolled steel sheet is degraded at approximately 475° C. (so-called 475° C. brittleness), the average cooling rate in a temperature range of 525° C. to 425° C. is preferably 100° C./hour or more.
Next, the hot-rolled steel sheet is annealed at 900° C. to 1,200° C. and more preferably at 900° C. to 1,100° C. for 30 to 240 seconds and is further processed by pickling. Furthermore, after cold rolling (preferably at a draft of 50% or more) is performed, annealing and pickling are performed to form a ferritic stainless steel sheet. To prevent the sulfur-containing inclusions from being coarsened, annealing after the cold rolling is preferably performed at less than 1,050° C. and more preferably at less than 900° C. for 10 to 240 seconds. When the annealing temperature is 900° C. or more, a time at a heating temperature of 900° C. or more is preferably set to 1 minute or less.
The above-described ferritic stainless steel sheet has a superior sulfate corrosion resistance even in a high-temperature atmosphere because of the synergetic effect of the intrinsic characteristics of ferritic stainless steel, that is, superior corrosion resistance in a high-temperature atmosphere, and the intrinsic characteristics disclosed in the above (a) to (c). Furthermore, since the ferrite crystal grains are fine, even when a bending work is performed at an angle of 90° or more, the space between adjacent ferrite crystal grains is decreased to a level at which no problems may occur. Hence, the degree of rough surface is reduced.
EXAMPLE 1
After ferritic stainless steel having components shown in Table 1 was formed by melting and was further formed into a slab, hot rolling (finishing temperature: 800° C., coiling temperature: 450° C., and sheet thickness: 4 mm) was performed by heating to 1,170° C., so that a hot-rolled steel sheet was formed. An average cooling rate from finish rolling to coiling (that is, from 800° C. to 450° C.) was set to 20° C./sec.
The hot-rolled steel sheet thus obtained was annealed at 900° C. to 1,200° C. for 30 to 300 seconds and was further processed by pickling. Next, after cold rolling was performed, annealing was performed at 970° C. for 30 to 300 seconds and was further processed by pickling, so that a ferritic stainless steel sheet (sheet thickness: 0.8 mm) was obtained.
The ferritic stainless steel sheet thus obtained was cut into a sheet having a width of 30 mm and a length of 50 mm, and two surfaces of this sheet was polished with #600 abrasive paper, so that a test piece was prepared. This test piece was observed using a scanning electron microscope (so-called SEM), and grain diameters of all sulfur-containing inclusions present in one arbitrary viewing field having a size of 10 mm square were measured. The maximum length of the long axis was regarded as the grain diameter. The grain diameter of the largest one among the measured sulfur-containing inclusions was regarded as the maximum grain diameter. The results are shown in Table 2. Furthermore, the mass of the test piece was measured.
Next, after the test piece was immersed in sulfuric acid (concentration: 10 mass percent, and temperature: 50° C.) for 48 hours, the mass of the test piece was measured, so that the sulfate corrosion resistance was investigated. For the sulfate corrosion resistance, the change in mass of the test piece before and after the immersion was calculated. When the change in mass of the test piece with respect to the mass thereof before the immersion was less than 10%, it was evaluated as Good (◯), and when the change in mass was 10% or more, it was evaluated as No good (x). The results are shown in Table 2.
A1 to A4 shown in Table 2 are examples in which the Cu content was changed. According to A2 and A3 which were within our range, a superior sulfate corrosion resistance was obtained. B1 to B4 shown in Table 2 are examples in which the S content was changed. According to B1 to B3 which were within our range, a superior sulfate corrosion resistance was obtained. C1 to C5 shown in Table 2 are examples in which the Nb content was changed. According to C2 to C4 which were within our range, a superior sulfate corrosion resistance was obtained. D1 to D4 shown in Table 2 are examples in which the maximum grain diameter of the sulfur-containing inclusions was changed. According to D1 and D2 which were within our range, a superior sulfate corrosion resistance was obtained. E1 to E7 shown in Table 2 are examples in which at least one of Ti, Zr, and Mo was further added as an additional element. According to E1 to E7 which were within our range, a superior sulfate corrosion resistance was obtained.
On the other hand, A1 and A4 shown in Table 2 are comparative examples in which the Cu content was out of our range. B4 is a comparative example in which the S content was out of our range. C1 and C5 are comparative examples in which the Nb content was out of our range. D3 and D4 are comparative examples in which the maximum grain diameter of the sulfur-containing inclusions was out of our range. In addition, E8 to E10 are comparative examples in which the content of at least one of Al, Cr, Nb, and N was out of our range. According to the comparative examples which were out of our range, a superior sulfate corrosion resistance could not be obtained.
EXAMPLE 2
In addition to the confirmation of the effect on the sulfate corrosion resistance, the effect on the degree of rough surface at a bent part formed by a bending work performed at an angle of 90° or more was further confirmed.
After ferritic stainless steel having components shown in Table 3 was formed by melting and was then processed by continuous casting, hot rolling of an obtained slab was performed by heating to 1,170° C. The finishing temperature and the coiling temperature are shown in Table 4. Among slabs of Nos. 1 to 29 shown in Table 3, No. 1 and No. 5 are examples in which the Nb content was out of our range; No. 13 is an example in which the Cu content was out of our range; No. 28 is an example in which the C content was out of range; and the other Nos. were all within our range.
Obtained hot-rolled steel sheets were cooled from the finishing temperature to the coiling temperature of the hot rolling at an average cooling rate of 25° C./sec. The hot-rolled steel sheets were annealed at 900° C. to 1,100° C. (however, only No. 9 was annealed at 1,150° C.) and were further processed by pickling to remove scale. Next, after cold rolling was performed, annealing (heating temperature: 970° C., and heating time: 90 seconds) and pickling were further performed, so that ferritic stainless steel sheets (sheet thickness: 0.8 mm) were obtained. The finishing temperature of the hot rolling, the coiling temperature thereof, and the draft of the cold rolling are shown in Table 4. Nos. 9, 17, 21, 25, and 29 are examples in which at least one of the finishing temperature of the hot rolling, the coiling temperature thereof, the annealing temperature for the hot-rolled steel sheet, and the draft of the cold rolling was out of our range.
After an arbitrary cross section of the ferritic stainless steel sheet was etched with diluted aqua regia, grain diameters of ferrite crystal grains in 3 arbitrary viewing fields were measured by an intercept method in accordance with ASTM E 112, and the average value of the grain diameters was calculated. The results are shown in Table 4.
In addition, an arbitrary cross section of the ferritic stainless steel sheet was observed by a scanning electron microscope (so-called SEM), and the maximum grain diameter of precipitated NbC grains was measured. Among NbC inclusions in one arbitrary viewing field having a size of 10 mm square, the grain diameter of the largest one was measured. The maximum long axis length was regarded as the maximum grain diameter. The results are shown in Table 4.
Furthermore, after a sample having a width of 20 mm and a length of 70 mm was cut out of the ferritic stainless steel sheet, two surfaces of the sample were polished with #600 abrasive paper, and a bending work was then performed. The bending work was performed in such a way that the sample was bent at angle of 180° by pressing a central portion thereof with a punch having a radius of 10 mm.
After the bending work was performed, the cross section of the bent part in 3 arbitrary viewing fields was observed, and the rough-surface depth was measured. A method for measuring the rough-surface depth is shown in FIG. 2 . After the cross section of the bent part was enlarged at a magnification of 1,000 using an optical microscope, a photograph of the cross section was taken, and as shown in FIG. 2 , the largest difference between adjacent convex and concave portions of the rough surface on the cross section of the observed bent part was regarded as the rough-surface depth. A rough-surface depth of 30 μm or less was evaluated as Good (◯), and a rough-surface depth of more than 30 μm was evaluated as No good (x). The results are shown in Table 4.
As apparent from Table 4, according to our examples, the rough-surface depths were all 30 μm or less; however, according to comparative examples, the depths were more than 30 μm.
In addition, although not described here, the effect on the sulfate corrosion resistance was also confirmed, and similar effect to that of Example 1 was also confirmed.
TABLE 1
COMPOSITION (mass percent)
OTHER
C
Si
Mn
P
S
Al
Cr
Ni
Cu
Nb
N
ELEMENTS
REMARKS
A1
0.011
0.11
0.17
0.032
0.002
0.028
20.6
0.28
0.23
0.24
0.010
—
COMPARATIVE EXAMPLE
A2
0.008
0.12
0.16
0.030
0.004
0.024
21.0
0.22
0.33
0.27
0.010
—
INVENTION EXAMPLE
A3
0.008
0.13
0.17
0.031
0.004
0.024
21.4
0.23
0.55
0.27
0.011
—
INVENTION EXAMPLE
A4
0.009
0.14
0.16
0.032
0.007
0.026
21.8
0.29
0.85
0.24
0.012
—
COMPARATIVE EXAMPLE
B1
0.007
0.14
0.18
0.022
0.001
0.029
20.3
0.27
0.42
0.42
0.010
—
INVENTION EXAMPLE
B2
0.007
0.14
0.19
0.020
0.005
0.028
20.5
0.25
0.43
0.38
0.009
—
INVENTION EXAMPLE
B3
0.008
0.15
0.18
0.022
0.008
0.029
20.8
0.25
0.45
0.38
0.009
—
INVENTION EXAMPLE
B4
0.007
0.16
0.18
0.027
0.014
0.029
20.4
0.27
0.43
0.40
0.009
—
COMPARATIVE EXAMPLE
C1
0.008
0.13
0.17
0.031
0.004
0.033
22.4
0.28
0.23
0.16
0.011
—
COMPARATIVE EXAMPLE
C2
0.010
0.12
0.18
0.030
0.008
0.052
22.5
0.27
0.35
0.27
0.014
—
INVENTION EXAMPLE
C3
0.009
0.14
0.16
0.032
0.007
0.049
22.7
0.29
0.33
0.35
0.012
—
INVENTION EXAMPLE
C4
0.009
0.14
0.15
0.032
0.007
0.035
22.7
0.29
0.30
0.46
0.012
—
INVENTION EXAMPLE
C5
0.010
0.12
0.18
0.030
0.008
0.044
22.5
0.26
0.29
0.58
0.014
—
COMPARATIVE EXAMPLE
D1
0.012
0.24
0.28
0.028
0.008
0.025
20.8
0.28
0.32
0.39
0.013
—
INVENTION EXAMPLE
D2
0.011
0.25
0.25
0.027
0.008
0.016
21.0
0.29
0.57
0.41
0.015
—
INVENTION EXAMPLE
D3
0.009
0.24
0.28
0.028
0.009
0.022
20.9
0.28
0.46
0.40
0.008
—
COMPARATIVE EXAMPLE
D4
0.011
0.25
0.24
0.029
0.009
0.021
21.1
0.28
0.45
0.39
0.010
—
COMPARATIVE EXAMPLE
E1
0.011
0.16
0.17
0.029
0.002
0.021
22.1
0.22
0.48
0.25
0.010
Ti: 0.08
INVENTION EXAMPLE
E2
0.016
0.18
0.16
0.030
0.003
0.083
22.2
0.24
0.47
0.28
0.019
Zr: 0.03
INVENTION EXAMPLE
E3
0.014
0.22
0.17
0.030
0.004
0.072
20.8
0.20
0.33
0.33
0.016
Mo: 0.14
INVENTION EXAMPLE
E4
0.011
0.16
0.15
0.029
0.002
0.046
20.1
0.29
0.45
0.27
0.013
Ti: 0.23, Zr: 0.37
INVENTION EXAMPLE
E5
0.017
0.18
0.16
0.032
0.001
0.053
23.2
0.27
0.42
0.28
0.014
Zr: 0.11, Mo: 0.27
INVENTION EXAMPLE
E6
0.015
0.20
0.17
0.031
0.005
0.022
23.8
0.25
0.38
0.22
0.011
Ti: 0.02, Mo: 0.71
INVENTION EXAMPLE
E7
0.018
0.54
0.18
0.029
0.001
0.022
23.7
0.28
0.32
0.23
0.012
Ti: 0.10,
INVENTION EXAMPLE
Zr: 0.05,
Mo: 0.13
E8
0.032
0.17
0.16
0.030
0.002
0.023
24.3
0.31
0.55
0.27
0.044
—
COMPARATIVE EXAMPLE
E9
0.008
0.13
0.17
0.031
0.001
0.122
19.0
0.33
0.55
0.27
0.011
—
COMPARATIVE EXAMPLE
E10
0.010
0.12
0.32
0.030
0.015
0.038
24.5
0.32
0.72
0.53
0.014
—
COMPARATIVE EXAMPLE
TABLE 2
MAXIMUM DIAMETER
CORROSION
OF S-CONTAINING
RESISTANCE IN
INCLUSIONS (μm)
SULFURIC ACID*1
REMARKS
A1
1.6
x
COMPARATIVE
EXAMPLE
A2
2.7
∘
INVENTION EXAMPLE
A3
2.5
∘
INVENTION EXAMPLE
A4
3.2
x
COMPARATIVE
EXAMPLE
B1
2.5
∘
INVENTION EXAMPLE
B2
3.1
∘
INVENTION EXAMPLE
B3
3.3
∘
INVENTION EXAMPLE
B4
4.9
x
COMPARATIVE
EXAMPLE
C1
4.3
x
COMPARATIVE
EXAMPLE
C2
2.4
∘
INVENTION EXAMPLE
C3
2.7
∘
INVENTION EXAMPLE
C4
3.1
∘
INVENTION EXAMPLE
C5
4.8
x
COMPARATIVE
EXAMPLE
D1
2.3
∘
INVENTION EXAMPLE
D2
4.4
∘
INVENTION EXAMPLE
D3
7.5
x
COMPARATIVE
EXAMPLE
D4
9.2
x
COMPARATIVE
EXAMPLE
E1
1.5
∘
INVENTION EXAMPLE
E2
1.4
∘
INVENTION EXAMPLE
E3
1.8
∘
INVENTION EXAMPLE
E4
1.9
∘
INVENTION EXAMPLE
E5
1.8
∘
INVENTION EXAMPLE
E6
2.2
∘
INVENTION EXAMPLE
E7
0.7
∘
INVENTION EXAMPLE
E8
4.9
x
COMPARATIVE
EXAMPLE
E9
3.6
x
COMPARATIVE
EXAMPLE
E10
10.3
x
COMPARATIVE
EXAMPLE
*1A dissolved amount of less than 10% is represented by ∘, and a dissolved amount of 10% or more is represented by x.
TABLE 3
COMPOSITION (MASS PERCENT)
NO.
C
Si
Mn
P
S
Al
Cr
Ni
Cu
Nb
N
REMARKS
1
0.011
0.18
0.18
0.027
0.008
0.016
22.0
0.29
0.57
0.17
0.015
COMPARATIVE EXAMPLE
2
0.009
0.13
0.17
0.031
0.005
0.025
21.5
0.30
0.48
0.28
0.011
INVENTION EXAMPLE
3
0.012
0.18
0.18
0.029
0.001
0.021
20.7
0.28
0.32
0.44
0.010
INVENTION EXAMPLE
4
0.014
0.18
0.16
0.032
0.003
0.031
21.2
0.31
0.47
0.52
0.014
INVENTION EXAMPLE
5
0.011
0.16
0.17
0.029
0.009
0.021
23.1
0.28
0.45
0.59
0.010
COMPARATIVE EXAMPLE
6
0.011
0.16
0.17
0.029
0.002
0.021
23.1
0.28
0.45
0.38
0.010
INVENTION EXAMPLE
7
0.007
0.16
0.18
0.033
0.008
0.029
22.3
0.27
0.43
0.37
0.009
INVENTION EXAMPLE
8
0.007
0.14
0.19
0.031
0.005
0.028
22.5
0.25
0.43
0.39
0.009
INVENTION EXAMPLE
9
0.011
0.18
0.18
0.027
0.008
0.016
22.0
0.29
0.57
0.38
0.014
COMPARATIVE EXAMPLE
10
0.008
0.13
0.17
0.031
0.004
0.024
21.4
0.33
0.55
0.52
0.011
INVENTION EXAMPLE
11
0.012
0.19
0.16
0.028
0.008
0.025
23.8
0.33
0.32
0.53
0.013
INVENTION EXAMPLE
12
0.011
0.22
0.17
0.031
0.005
0.022
23.8
0.30
0.33
0.49
0.011
INVENTION EXAMPLE
13
0.011
0.11
0.17
0.032
0.002
0.028
20.6
0.28
0.23
0.51
0.013
COMPARATIVE EXAMPLE
14
0.007
0.16
0.18
0.033
0.009
0.029
22.3
0.27
0.43
0.35
0.009
INVENTION EXAMPLE
15
INVENTION EXAMPLE
16
INVENTION EXAMPLE
17
COMPARATIVE EXAMPLE
18
0.008
0.12
0.16
0.030
0.004
0.024
21.0
0.31
0.33
0.35
0.010
INVENTION EXAMPLE
19
INVENTION EXAMPLE
20
INVENTION EXAMPLE
21
COMPARATIVE EXAMPLE
22
0.007
0.14
0.18
0.031
0.001
0.029
22.3
0.27
0.42
0.36
0.010
INVENTION EXAMPLE
23
INVENTION EXAMPLE
24
INVENTION EXAMPLE
25
COMPARATIVE EXAMPLE
26
0.009
0.14
0.16
0.032
0.007
0.026
23.7
0.29
0.72
0.38
0.012
INVENTION EXAMPLE
27
0.009
0.15
0.16
0.032
0.003
0.027
21.2
0.30
0.41
0.52
0.011
INVENTION EXAMPLE
28
0.032
0.17
0.16
0.030
0.002
0.023
23.3
0.31
0.55
0.18
0.044
COMPARATIVE EXAMPLE
29
0.012
0.19
0.16
0.028
0.008
0.025
23.8
0.33
0.32
0.28
0.013
COMPARATIVE EXAMPLE
TABLE 4
AVERAGE
MAXIMUM
DRAFR
EVALUATION
FERRITE
GRAIN
OF
OF ROUGH
GRAIN
DIAMETER
FINISHING
COILING
COLD
SURFACE
DIAMETER
OF NbC
TEMPERATURE
TEMPERATURE
ROLLING
AT BENT
NO.
(μm)
(μm)
(° C.)
(° C.)
(%)
PART *1
REMARKS
1
17.9
0.25
740
432
75
x
COMPARATIVE
EXAMPLE
2
18.2
0.28
743
430
76
∘
INVENTION
EXAMPLE
3
18.3
0.33
736
430
75
∘
INVENTION
EXAMPLE
4
19.4
0.35
737
431
75
∘
INVENTION
EXAMPLE
5
18.7
0.38
745
435
75
x
COMPARATIVE
EXAMPLE
6
15.4
0.46
752
434
75
∘
INVENTION
EXAMPLE
7
18.7
0.48
751
435
76
∘
INVENTION
EXAMPLE
8
23.3
0.47
752
432
75
∘
INVENTION
EXAMPLE
9
32.2
0.48
753
432
74
x
COMPARATIVE
EXAMPLE
10
18.4
0.45
760
432
75
∘
INVENTION
EXAMPLE
11
17.2
0.71
762
431
75
∘
INVENTION
EXAMPLE
12
18.4
0.88
765
433
74
∘
INVENTION
EXAMPLE
13
17.9
1.21
763
434
75
x
COMPARATIVE
EXAMPLE
14
14.3
0.36
745
433
75
∘
INVENTION
EXAMPLE
15
20.2
0.63
752
432
75
∘
INVENTION
EXAMPLE
16
25.4
0.84
764
435
74
∘
INVENTION
EXAMPLE
17
31.0
1.08
782
436
75
x
COMPARATIVE
EXAMPLE
18
18.3
0.44
758
407
75
∘
INVENTION
EXAMPLE
19
21.7
0.43
759
422
74
∘
INVENTION
EXAMPLE
20
24.5
0.45
760
446
76
∘
INVENTION
EXAMPLE
21
31.8
0.44
758
467
75
x
COMPARATIVE
EXAMPLE
22
16.8
0.32
752
435
85
∘
INVENTION
EXAMPLE
23
19.4
0.38
753
435
74
∘
INVENTION
EXAMPLE
24
24.7
0.34
752
432
62
∘
INVENTION
EXAMPLE
25
30.2
0.36
751
433
48
x
COMPARATIVE
EXAMPLE
26
15.3
0.33
752
438
80
∘
INVENTION
EXAMPLE
27
24.4
0.47
753
440
81
∘
INVENTION
EXAMPLE
28
34.3
1.55
753
433
88
x
COMPARATIVE
EXAMPLE
29
32.5
1.43
852
512
81
x
COMPARATIVE
EXAMPLE
*1: A rough-surface depth at a bent part of 30 μm or less is represented by ∘, and a rough-surface depth of more than 30 μm is represented by x. | Disclosed is a ferritic stainless steel sheet which has excellent corrosion resistance against sulfuric acid in the high-temperature environment and shows less surface roughness at a bent part which is bent at 90° or more. Specifically disclosed is a ferritic stainless steel sheet which has the following chemical composition: C: 0.02 mass % or less, Si: 0.05 to 0.8 mass %, Mn: 0.5 mass % or less, P: 0.04 mass % or less, S: 0.010 mass % or less, Al: 0.10 mass % or less, Cr: 20 to 24 mass % Cu: 0.3 to 0.8 mass %, Ni: 0.5 mass % or less, Nb: 0.20 to 0.55 mass %, and N: 0.02 mass % or less, with the remainder being Fe and unavoidable impurities; and which has such a structure that the maximum particle diameter of an S-containing precipitate is 5 μm or smaller. | 2 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for applying tension to a tubular member and to a method of using the same. In particular, the present invention relates to an apparatus for tensioning tubular members used in offshore oil and gas drilling and production operations, for example the legs of tensions leg platforms, casing strings and risers, and a method for carrying out the same.
BACKGROUND OF THE INVENTION
Many situations require a tubular member to be placed under tension. Such situations arise in many different aspects of the operations for exploration, drilling and production of oil and gas, in particular in offshore locations. Examples of situations requiring tubular members to be tensioned include the setting of tension leg platforms for offshore drilling and production operations. Further examples arise in the drilling and production of oil and gas from wells accessed through wellheads located on the sea floor, and include the tensioning of risers and casing strings extending between a hanger located in a wellhead on the seabed and a wellhead mounted on a platform or vessel at the surface.
U.S. Pat. No. 4,794,988 discloses a surface wellhead apparatus for use in tying back casings extending to a subsea structure. The casing is held under tension by a lock member which engages on a shoulder within the surface wellhead. A similar arrangement is described in U.S. Pat. No. 4,938,289. Both arrangements require the casing string to be first placed under tension, after which the casing may be held in tension using the arrangements disclosed.
U.S. Pat. No. 4,995,464 describes an offshore well installation in which an adjustable assembly is employed to tension a casing string or other tubular member. The installation comprises a first tubular member and a second tubular member arranged concentrically with a sleeve disposed therebetween. The sleeve is formed with an inner and outer thread thereon, engaging with corresponding outer and inner threads on the first and second tubular members. A lug is disposed between the first and second tubular members to prevent relative rotation of one against the other. Rotation of the sleeve moves the first and second sleeves longitudinally with respect to one another, thus allowing a tension to be placed on the casing string. While the arrangement can be operated to apply tension to the casing string without requiring the string to be tensioned by other means, this is only possible by rotation of the sleeve.
U.S. Pat. No. 5,638,903 discloses an adjustable mandrel hanger system for maintaining tension in a string of casing extending between a subsea wellhead assembly and a surface wellhead housing. A mandrel is secured to the end of the casing string, to which is mounted a locking member. The locking member lands against a shoulder in the wellhead housing. Upon installation, the operator applies tension to the casing string. The mandrel moves upwards relative to the locking member as the tension is applied. Upon release of the tension applied by the operator, the locking member will retain the mandrel and the string under tension against the shoulder. It is to be noted that the hanger system of U.S. Pat. No. 5,638,903 simply holds a casing string under tension, once the tension has been applied by the operator. The hanger system cannot itself be used to apply tension to the casing string.
U.S. Pat. No. 5,653,289 discloses a casing tensioning system for applying tension to a string of casing between a subsea wellhead and a surface wellhead. A casing hanger is secured to the casing: string. The casing hanger has a first position, allowing downward movement of the casing string with respect to the hanger, and a second position, in which upward movement of the casing string is allowed, but in which downward movement of the string relative to the hanger is prevented. The hanger is landed on a shoulder within the surface wellhead. The operator applies tension to the casing string, after which the casing hanger acts to retain the casing string under tension. Again, while the apparatus disclosed is sufficient to hold the tensioned casing string, it cannot be operated to apply the required tension to the string or another tubular member.
A similar arrangement is described in U.S. Pat. No. 5,671,812, in which a casing hanger is secured to a mandrel, the mandrel in turn being attached to a casing string to be tensioned. Again, the casing hanger allows upwards movement of the mandrel with respect to the hanger, but prevents relative downward movement of the mandrel. Hydraulic pressure is used to force the casing hanger to seat against a shoulder within the surface wellhead, after which the mandrel is raised, thereby placing the casing string under tension. As with the earlier designs discussed above, the casing hanger, while retaining the casing string under tension once sufficient tension has been applied, does not act itself to apply tension to the casing string.
An arrangement similar to that of U.S. Pat. No. 5,671,812 is disclosed in U.S. Pat. No. 5,944,111, with the difference that a launch adaptor is used to force the casing hanger against the shoulder in the surface wellhead, after which tension is applied to the casing. The casing hanger acts to retain the string of casing under tension in a similar manner to that described in U.S. Pat. No. 5,671,812.
It can be seen that a variety of assemblies have been proposed to retain a tubular member, such as a casing string, under tension between two fixed assemblies. However, in such arrangements, it is necessary to provide additional means to place the tubular member under the required tension. U.S. Pat. No. 4,995,464 discloses an arrangement in which a single assembly is employed to both apply tension to a tubular member, in this instance a casing string, and retain the tubular member under tension, once applied. However, this arrangement only operates by the interaction of a plurality of separate threads formed on various of the tubular components. The machining of threads is time consuming and undesirable.
Accordingly, it can be seen that there is a need for an assembly which can be attached to a tubular member, such as a string of casing in an offshore well, and operated to both apply tension to the tubular member and retain the member under tension, once applied, by linear movement of the components of the assembly and without the need for components to be rotated or formed with threads.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided an apparatus for securing a tubular member under tension, the member secured to and extending between a first and second, fixed assembly, the apparatus comprising:
a first tubular assembly connectable at a first engageable portion to the tubular member to be tensioned;
a second tubular assembly having a first and a second engageable portion, the second tubular assembly being arranged concentrically with respect to the first tubular assembly and movable longitudinally with respect to the first tubular assembly;
a first engagement assembly for engaging the first engageable portion of the second tubular assembly with the first fixed assembly, such that movement of the second tubular assembly toward the tubular member to be tensioned is prevented;
a second engagement assembly for engaging the second engageable portion of the second tubular assembly with the first tubular assembly upon longitudinal movement of the second engageable portion of the second tubular assembly with respect to the first tubular assembly toward the first engageable portion of the first tubular assembly;
wherein the second tubular assembly can be placed under tension by moving its second engageable portion longitudinally relative to its first engageable portion, when the first engageable portion is engaged with the first fixed assembly.
When the first tubular assembly is attached to a tubular member, such as a casing string or riser, longitudinal movement of the second engageable portion of the second tubular assembly toward the tubular member applies tension to the second tubular assembly, in turn tensioning the tubular member. The apparatus of the present invention may thus be installed to secure an end of the tubular member, for example a casing string or riser, to a first fixed assembly, for example a surface wellhead. Once the tubular member has been attached to the second fixed assembly, for example a subsea wellhead, the apparatus may also be used to tension the tubular member, without the need for additional tensioning equipment. The tension is applied by moving the second engageable portion of the second tubular assembly in a longitudinal direction and, thus, does not require any of the components to be rotated or be formed with any additional threaded sections, other than those conventionally found in such systems. This is turn allows the apparatus to be manufactured in a simple manner.
In a preferred embodiment, the second engageable portion of the second tubular assembly extends concentrically within the first tubular assembly.
The first engagement assembly comprises a locking collar, the locking collar for engaging a shoulder in the first fixed assembly. In this arrangement, the locking collar simply bears against the shoulder, in order to prevent the second tubular assembly from moving towards the tubular member to be secured and tensioned. The first engagement assembly may further comprise a locking ring, for engaging a groove in the first fixed assembly. The locking ring may be biased into engagement with the groove. In an alternative arrangement, the locking collar is movable longitudinally with respect to the second tubular assembly upon contact with the shoulder in the first fixed assembly, such movement urging the locking ring into engagement with the groove in the first fixed assembly.
Preferably, the second engagement assembly allows the second engageable portion of the second tubular assembly, when engaged with the first tubular assembly, to move away from the first engageable portion of the second tubular assembly.
In a preferred embodiment, the second engagement assembly allows the second engageable portion of the second tubular assembly to engage with the first tubular assembly in one of a plurality different positions. This arrangement allows the tension being applied to the tubular member to be varied, while still allowing the first and second tubular assemblies to engage, in turn securing the tubular member to the first fixed assembly.
Preferably, the second engagement assembly has a first operating mode, in which engagement between the first and second tubular assemblies is not possible, and a second operating mode, in which engagement between the first and second tubular assemblies is possible. In this way, the second engagement assembly may be held inoperative, until the necessary steps have been taken to secure the apparatus to the tubular member to be secured and tensioned and until the second tubular assembly has been engaged with the first fixed assembly by the first engagement assembly. Most preferably, the second engagement assembly is moved from the first operating mode to the second operating mode upon the application of a predetermined tension to the second tubular assembly.
In a specific embodiment of the apparatus of the present invention the second engagement assembly comprises a first groove in the first tubular assembly and a second groove in the second tubular assembly, the second engagement assembly further comprising a locking ring for engaging both the first groove and the second groove. Preferably, a plurality of first grooves are provided, thereby allowing the second engageable portion of the second tubular assembly to engage the first tubular assembly in a plurality of different positions. The locking ring of the second engagement assembly may be held completely within the second groove in the second tubular assembly until a predetermined tension is applied to the second tubular assembly.
A tensioning collar may be provided in the second tubular assembly at its second engageable portion, the tensioning collar being engageable by a tool for tensioning the second tubular assembly. If present, the tensioning collar is preferably movable between a first position, in which the tensioning collar holds the locking ring completely within the second groove, and a second position, in which the locking ring is released to engage the first groove. The locking ring is preferably biased into engagement with the first groove, the tensioning collar holding the locking ring against its bias in the first position. The tensioning collar may be arranged to move from the first position into the second position at a predetermined tension applied to the second tubular assembly.
The apparatus of the present invention may be used to secure and tension tubular members in general. However, the apparatus finds particularly advantageous application in the securing and tensioning of casing string, risers, and the legs of a tension leg platforms.
In a further aspect, the present invention provides a method for securing and tensioning a tubular member, the tubular member extending between a first fixed assembly and a second fixed assembly, the method comprising:
securing a first tubular assembly to the tubular member;
providing a second tubular assembly, having a first engageable portion and a second engageable portion;
securing the second tubular assembly at its first engageable portion to the first fixed assembly, such that the first tubular assembly is prevented from moving towards the tubular member;
applying tension to the second tubular assembly by moving the second engageable portion away from the first engageable portion by applying a force longitudinally to the second tubular assembly;
engaging the second engageable portion of the second tubular assembly with the first tubular assembly.
The second tubular assembly is preferably moved longitudinally from a disengaged position to an engaged position, in which the second tubular assembly is engaged with the first fixed assembly, the longitudinal movement of the second tubular assembly being continued to tension the second tubular assembly and engage the second tubular assembly with the first tubular assembly.
It is advantageous if the engagement of the second engageable portion of the second tubular assembly is carried out selectively, when the second tubular assembly has been position appropriately with respect to the first tubular assembly, prior to which the engagement of the two assemblies not being possible. In a preferred embodiment, the second engageable portion of the second tubular assembly is engaged with the first tubular assembly upon application of a predetermined tension to the second tubular assembly.
Preferably, an engagement assembly is provided to engage the second engageable portion of the second tubular assembly with the first tubular assembly, the engagement assembly being biased into an engaged position, the engagement assembly being held in a disengaged position until application of the predetermined tension to the second tubular assembly.
In a preferred embodiment, the second engageable portion of the second tubular assembly is engageable with first tubular member in a plurality of positions. In this way, the tension applied to the tubular member may be varied, as required by the prevailing circumstances.
In a further aspect, the present invention provides an apparatus for use as a tool for securing and tensioning a tubular member, such as a casing string or riser. Accordingly, an apparatus for securing and tensioning a tubular member in a first fixed assembly, the apparatus comprising:
a first engagement assembly, for securing the apparatus with respect to the tubular member;
a second engagement assembly for engaging a tubular assembly and applying tension to the tubular assembly by longitudinal movement towards the tubular member.
In the apparatus, longitudinal movement of the second engagement assembly preferably secures the tubular assembly in the first fixed assembly, after which continued longitudinal movement applies tension to the tubular assembly.
In a preferred embodiment, the apparatus further comprises a piston, the second engagement assembly being attached to the piston, the piston being moveable in a longitudinal direction with respect to the tubular assembly. The piston is most conveniently moved by means of a hydraulic fluid.
Specific embodiments of the apparatus and method of the present invention will now be described in detail having reference to the accompanying drawings. The detailed description of these embodiments and the referenced drawings are by way of example only and are not intended to limit the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will now be described, by way of example only, having reference to the accompanying drawings, in which:
FIGS. 1 a and 1 b comprises a longitudinal cross-sectional view of an embodiment of the apparatus of the present invention in position within a surface wellhead and secured to a casing string, the portion of the figure to the left of the center line showing the apparatus in the disengaged, untensioned position, and the portion of the figure to the right of the center line showing the apparatus in the engaged, tensioned position; and
FIGS. 2 a and 2 b comprise the longitudinal cross-sectional view of FIG. 1, with a tool according to an embodiment of the present invention in place.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A surface wellhead assembly is shown in FIGS. 1 a and 1 b and generally referred to as 2 . The wellhead assembly 2 comprises a surface wellhead 4 . A casing string 6 extends between the surface wellhead 4 and a subsea wellhead (not shown). The surface wellhead 4 and casing string 6 are conventional design and well known in the art. The surface wellhead 4 is formed with an internal shoulder 8 on its inner surface. A landing groove 9 is formed in the inner surface of the surface wellhead 4 above the internal shoulder 8 .
A casing securing and tensioning apparatus according to one embodiment of the present invention is shown in FIGS. 1 a and 1 b , generally indicated by the reference 10 . The apparatus 10 comprises a first tubular assembly 12 , in turn comprising an outer sleeve 14 . The outer sleeve 14 is secured at its lower end 16 to the upper end of the casing string 6 by means of a threaded connection 18 . Other means for connecting a tubular member to a casing string such as are known in the art may also be employed for this purpose. The lower end 16 of the outer sleeve 14 comprises a portion of increased wall thickness 20 , having a circumferential groove 22 formed in its inner surface. The function of the groove 22 will be described further hereinbelow.
The outer sleeve 14 has a middle portion, having a plurality of circumferential locking grooves 24 formed into its inner surface. The lands between the grooves are each formed with a lower surface extending perpendicular to the inner surface of the outer sleeve, and an upper surface sloped at an acute angle to the longitudinal axis of the outer sleeve 14 downwards and inwards from the inner surface of the outer sleeve 14 , as viewed in FIG. 1 b . As described hereinafter, this arrangement allows the grooves 24 on the inner surface of the outer sleeve to be engaged in such as manner as to allow movement of the engaging means longitudinally towards the casing string 6 , but to prevent movement of the engaging means longitudinally away from the casing string 6 .
A support ring 30 is mounted on the upper end of the outer sleeve 14 , by means of bolts 32 . A ring seal 34 sits in a groove in the inner surface of the support ring 30 .
The apparatus 10 further comprises a second tubular assembly 40 , comprising an inner sleeve 42 , extending concentrically into and movable longitudinally within the outer sleeve 14 . The inner sleeve 42 is guided in its movement within the outer sleeve 14 by the support ring 30 on the upper end of the outer sleeve 14 . The seal 34 bears against the outer surface of the inner sleeve 42 . Further guidance for the inner sleeve 42 in its movement within the outer sleeve 14 is provided by a circumferential seal ring 44 disposed between the inner sleeve 42 and the outer sleeve 14 and moveable with the inner sleeve 42 . The seal ring 44 is restrained in its movement by a shoulder 46 , formed in the outer surface of the inner sleeve, 42 below the seal ring 44 , and a ring 48 located in a groove in the outer surface of the inner sleeve 42 above the seal ring 44 .
The second tubular assembly 40 further comprises a hanger 50 of a generally cylindrical form, mounted on the upper end of the inner sleeve 42 by means of a threaded connection 52 . The hanger 56 comprises an engagement assembly, generally indicated as 54 , on its outer surface. The engagement assembly 54 comprises a tapered load shoulder 58 formed in the outer surface of the hanger 50 and having a surface angled to extend downwards and inwards, as viewed in FIG. 1 a . A tapered locking ring 60 is disposed around the hanger 50 . The tapered locking ring 60 has an inner surface with a corresponding, but opposite angle to that of the angled surface of the tapered load shoulder 58 . The tapered locking ring 60 is moveable longitudinally against the tapered load shoulder 58 . A load ring 62 is disposed about the hanger 50 below the tapered locking ring 60 , as viewed in FIG. 1 a . The load ring 62 is moveable longitudinally along the outer surface of the hanger, restrained between the tapered load shoulder 58 and a retaining ring 64 seated in a groove in the outer surface of the hanger 50 .
At its lower end, an engagement assembly, generally indicated as 70 , is provided for engaging with the locking grooves 24 in the inner surface of the outer sleeve 14 . The engagement assembly 70 comprises a locking ring 72 seated in a groove 74 in the outer surface of the inner sleeve 42 . The groove 74 is of a sufficient size and depth so as to be able to accommodate the locking ring 72 such that the locking ring 72 does not extend beyond the surface of the inner sleeve 42 . The locking ring 72 is sized, so as to be naturally biased into an engagement position, in which a portion of the locking ring 72 extends out of the groove 74 beyond the surface of the inner sleeve 42 . As shown in the right hand portion of FIG. 1 b , when the inner sleeve 42 is in the appropriate position, the locking ring 72 will engage with a locking groove 24 on the inner surface of the outer sleeve 14 .
The engagement assembly 70 further comprises a tensioning collar 78 extending around and below the lower end of the inner sleeve 42 . The tensioning collar 78 comprises a first sleeve portion 80 extending longitudinally towards the locking ring 72 from the lower end of the inner sleeve 42 . The tensioning collar 78 further comprises an engagement portion 82 extending below the lower end of the inner sleeve 42 , having a tensioning groove 84 formed in its inner surface. The tensioning collar 78 is moveable longitudinally between a first position, as shown in the left hand portion of FIG. 1 b , and a second position, as shown in the right hand portion of FIG. 1 b . In the first position, the tensioning collar 78 is in a raised position, in which the first sleeve portion 80 extends to the locking ring 72 and the groove 74 , and holds the locking ring 72 fully within the groove 74 . In the second position, the tensioning collar 78 is in a lowered position, in which the first sleeve portion 80 does not extend to the locking ring 72 and the groove 74 . In this position, the bias of the locking ring 72 allows it to protrude from the groove 74 . A shear pin 86 holds the tensioning collar 78 in the first position, until sheared, as described hereinafter. As an alternative to the shear pin 86 , a shear ring may be employed. A retaining ring 87 retains the tensioning collar 78 on the lower end of the inner sleeve 42 and limits its movement.
Referring to FIGS. 2 a and 2 b , there is shown the apparatus of FIGS. 1 a and 1 b in place in a surface wellhead with a tool inserted for placing and tensioning the apparatus and the casing string. The tool as shown in FIGS. 2 a and 2 b is generally indicated as 100 . The tool 100 is suspended from a tubular string 102 by a conventional threaded connection 104 . The tool 100 further comprises a generally cylindrical tool body 106 connected at its upper end to the tubular string 102 as described. A connector sleeve 108 is secured to the lower end of the tool body 106 , again in a conventional manner using a threaded connection 110 . A tubular piston sleeve 112 extends around the upper portion of the tool body 106 to provide an annular piston cavity 114 between the piston sleeve 112 and the tool body 106 . A tubular piston 116 is slideable longitudinally within the piston cavity 114 along the outer surface of the tool body 106 . A first conduit 120 is provided in the tool body 106 and connects with the upper portion of the piston cavity 114 , through which hydraulic fluid may be provided to move the piston 116 in a downwards direction, as seen in FIGS. 2 a and 2 b . A second conduit 122 is provided in the tool body, opening into the lower portion of the piston cavity 114 , through which hydraulic fluid may be provided in order to raise the piston 116 within the piston cavity 114 , as seen in FIG. 2 a and 2 b.
A first locking assembly, generally indicated as 124 , is mounted on the lower end portion of the piston 116 . The first locking assembly 124 comprises upper and lower housing portions 126 and 128 . A chamber 130 is formed between the lower housing portion 128 and the piston 116 , which is sealed at its lower end by a sealing ring 132 . Locking segments 134 extends between the upper and lower housing portions 126 and 128 , and are moveable radially when acted upon by a hydraulic ring 136 , which is moveable within the chamber 130 . A piston conduit 138 is provided in the piston 116 , through which hydraulic fluid can be supplied, in order to move the hydraulic ring 136 . As shown in FIG. 2 b , the hydraulic ring 136 is in its uppermost position, bearing against the locking segments 134 , which are in turn held in engagement with the tensioning groove 84 in the inner surface of the tensioning collar 78 . The locking segments 134 may be employed in conjunction with a locking ring to provide a higher load capacity for situations where needed.
The tool 100 further comprises a second locking assembly, generally indicated as 140 secured to its lower end. The second locking assembly 140 is similar in design and operation to the first locking assembly 124 . The second locking assembly 140 comprises a locking assembly body 142 , secured by a threaded connection 144 to the connector sleeve 108 . The second locking assembly 140 further comprises upper and lower housing portions 146 and 148 , which together define an annular chamber 150 with the locking assembly body 142 . Locking segments 152 are moveable radially between the upper and lower housing portions 146 and 148 , when acted upon by a piston 154 moveable longitudinally within the chamber 150 . A first locking conduit 156 is provided in the locking assembly body 142 , through which hydraulic fluid may be provided to the chamber 150 in order raise the piston 154 . A second locking conduit 158 is provided in the locking assembly body 142 , through which hydraulic fluid may be provided to the chamber 150 in order to lower the piston 154 . As shown in FIG. 2 b , the piston 154 is in the raised position and the locking segments 152 are engaged with the groove 22 in the end portion of the outer sleeve 14 . Again, the locking segments 152 may be employed in conjunction with a locking ring to provide a higher load capacity when needed.
A shoulder 180 is formed in the inner surface of the lower end 16 of the outer sleeve 14 of the apparatus 10 . As shown in FIG. 2 b , a corresponding shoulder 182 on the outer surface of the lower housing portion 148 of the tool 100 seats against the shoulder 180 when the tool 100 is inserted. In this way, the shoulders 180 and 182 ensure that the tool 100 is correctly positioned within the apparatus.
To install the casing securing and tensioning apparatus and secure and tension the casing string 6 the followed procedure is applied. As a first step, the apparatus is connected by means of the outer sleeve 14 to the casing string 6 using the conventional threaded connection 18 . At this point, the inner sleeve 42 is in the raised, unengaged position shown in the left hand portion of FIG. 1 a . In this position, the tensioning collar 78 is in the raised position, such that the locking ring 72 is held fully within the groove 74 . Thus, the inner sleeve 42 and the second tubular assembly 40 are free to move longitudinally within the outer sleeve 14 .
To secure and tension the casing string 6 , the tool 100 is inserted into the securing and tensioning apparatus 10 , to extend within the inner sleeve 42 and the outer sleeve 14 toward the casing string 6 . Hydraulic fluid is supplied under pressure through the first locking conduit 156 in the locking assembly body 142 into the chamber 150 , thereby raising the piston 154 to bear against the locking segments 152 , forcing it radially outwards into engagement with the groove 22 in the end portion of the outer sleeve 14 . The hydraulic fluid is maintained under pressure in the chamber 150 , in order to keep the locking segments 152 in the engaged position.
Thereafter, hydraulic fluid is supplied through the piston conduit 138 to the chamber 130 in the first locking assembly 132 , thereby raising the hydraulic ring 136 to bear against the locking segments 134 , forcing it radially outwards into engagement with the tensioning groove 84 in the tensioning collar 78 . The hydraulic fluid is maintained under pressure in the chamber 130 , in order to keep the locking segments 134 engaged with the tensioning groove 84 .
The position of the entire assembly after the aforementioned locking operations have been completed is shown in the left hand portion of FIGS. 2 a and 2 b . In this position, the tool 100 is fully engaged with both the first and second tubular assemblies 12 and 40 , with the second tubular assembly 40 in the raised position.
Once the two aforementioned locking operations have been completed, the steps may be taken in order to secure and tension the casing string 6 . Hydraulic fluid is fed under pressure through the conduit 120 in the tool body 106 into the piston cavity 114 , thereby urging the piston 116 longitudinally downwards towards the casing string 6 . The action of the piston 116 causes the inner sleeve 42 and the second tubular assembly 40 to move longitudinally into the surface wellhead 4 . The first result of this movement of the second tubular assembly 40 is that the load ring 62 of the engagement assembly 54 lands on the internal shoulder 8 within the surface wellhead 4 . The second tubular assembly 40 continues its longitudinal movement, bringing the tapered locking ring 60 down to bear against the load ring 62 . Continued movement of the second tubular assembly 40 urges the tapered locking ring outwards against the tapered load shoulder 58 on the hanger 50 and into engagement with the landing groove 9 in the surface wellhead 4 . At this point, further longitudinal movement of the second tubular assembly 40 is prevented. The engagement of the engagement assembly 54 with the shoulder 8 and groove 9 in the surface wellhead is shown in the right hand portion of FIGS. 1 a and 2 a.
The supply of hydraulic fluid to the piston cavity 114 is maintained, causing the piston 116 to continue its longitudinal movement towards the casing string 6 . With the engagement assembly 54 restraining further movement of the second tubular assembly 40 , further movement of the piston 116 applies tension to the inner sleeve 42 . At a given applied tension, the shear pin 86 retaining the tensioning collar 78 shears, allowing the tensioning collar 78 to move longitudinally with respect to the inner sleeve 42 . This in turn releases the locking ring 72 from the groove 74 . The bias of the locking ring 72 urges it into engagement with the corresponding groove 24 in the inner surface of the outer sleeve 14 . This position is shown in the right hand portion of FIGS. 2 a and 2 b.
At this point, the casing string 6 is secured and held under tension. Further tension may be applied by increasing the pressure of the hydraulic fluid in the piston cavity 114 , forcing the piston further towards the casing string 6 . As noted above, the grooves 24 and the corresponding lands in the inner surface of the outer sleeve 14 are formed to allow the locking ring 72 to move longitudinally towards the casing string 6 . As further tension is applied to the outer sleeve 42 , the locking ring 72 engages with successive grooves 24 as it moves towards the casing string 6 .
Once the requisite tension has been applied to the casing string 6 , the supply of hydraulic fluid to the piston cavity 114 is shut off. Thereafter, the supply of hydraulic fluid to the chamber 130 of the first locking assembly 124 is shut off, thus releasing the locking segments 134 from their engagement with the groove 84 in the tensioning collar 78 . Finally, the supply of hydraulic fluid to the chamber 150 of the second locking assembly 140 is removed. Hydraulic fluid is supplied through the second conduit 158 in the locking assembly body 142 , to lower the piston 154 , in turn releasing the locking segments 152 from engagement with the groove 22 in the outer sleeve 14 . The tool 100 may then be removed.
The aforementioned procedure may be used in reverse to remove the securing and tensioning apparatus 10 and release the casing string 6 .
The method and apparatus of the present invention have been described with respect to the installation and tensioning of a casing string in a surface wellhead. However, it is to be understood that the method and apparatus may be employed to secure and tension any suitable tubular member, including the legs and other tensioned members of a tension leg platform, as well as other tubular members employed in offshore drilling and production operations and other applications.
While the preferred embodiments of the present invention have been shown in the accompanying figures and described above, it is not intended that these be taken to limit the scope of the present invention and modifications thereof can be made by one skilled in the art without departing from the spirit of the present invention. | An apparatus for securing a tubular member under tension is provided, the member secured to and extending between a first and second fixed assembly. The apparatus comprises a first tubular assembly connectable at a first region to the tubular member to be tensioned and a second tubular assembly having a first and a second engageable portion, the second tubular assembly being arranged concentrically with respect to the first tubular assembly and movable longitudinally with respect to the first tubular assembly. A first engagement assembly is provided for engaging the first engageable portion of the second tubular assembly with the first fixed assembly, such that movement of the second tubular assembly toward the tubular member to be tensioned is prevented. A second engagement assembly is provided for engaging the second engageable portion of the second tubular assembly with the first tubular assembly upon longitudinal movement of the second engageable portion of the second tubular assembly with respect to the first tubular assembly toward the tubular member. In this way, the second tubular assembly can be placed under tension by moving its second engageable portion longitudinally relative to its first engageable portion, when the first engageable portion is engaged with the first fixed assembly. A method for securing a tubular member, together with a tool for installing the apparatus, is also enclosed. | 4 |
CITATION OF PROVISIONAL APPLICATION
This application for U.S. patent is a non-provisional conversion of U.S. provisional application for patent Ser. No. 60/525,809 filed on Nov. 28, 2003, and claims the benefit thereof.
BACKGROUND OF THE INVENTION
Marking is an important component in the processing of objects. Marking is actually communicating information and decisions to the processing units. Even for a temporary marking, like for a processing phase, labeling and scanning has been used. The method is restrictive, because the object has to be oriented all the time towards the scanners, otherwise the labels cannot be read. After a certain processing phase, the label may become obsolete, creating confusion. It needs additional equipment and time in the processing flow for this type of marking. Handling of large size of objects makes the classical method of marking also too slow.
Labels can be read one at a time, slowing down the parallel processing.
There are other fields, like in the military, where marking is also important-identifying the difference between target and neutral or even friendly objects-but labeling is impossible. Classical laser targeting is sequential, one object after the other, where the targeting has to follow the target until processing completes, making parallel processing impossible.
Thus there is a need for parallel processing, for a higher efficiency, and preferably for a substantially simultaneous marking.
SUMMARY OF THE INVENTION
The invention is directed to increasing the efficiency of existing laser marking and targeting systems, and helps also in decision making and process control.
The simultaneous laser marking/targeting system (SLTS) scans the field and simultaneously targets multiple objects—indifferent to their physical orientation, subjects to future processing—with a coded laser, such that each object receives and reflects specific information. The reflected information is read and used by one or more processing units to locate, to select, to approach and to process in substantially the same time the selected objects.
The marking and targeting system is controlled by at least one computer. A human operator can select the targets thru a human-machine interface (HMI), ‘by mouse-click’, for example. The presence of a human operator is optional. Decision making can be aided by image recognition software working together with at least one database. This can reduce the risk of human error, thus avoiding erroneous processing that can result in friendly fire or civilian casualties.
The differences from the classical “point at the target” procedure to the simultaneous targeting of the present invention is similar to the difference between the sequential search of information on magnetic bands to the direct memory access on hard-drives, the advantages are undeniable.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general view of the application of the invention.
FIG. 2 is an image of the processing area, with subjects to be precessed and neutral objects.
FIG. 3 is an image of the laser control camera, with multiple applied marks/labels.
FIG. 4 is a combined picture of FIG. 2 and FIG. 3 , showing the marked/targeted objects and the neutral objects together. This is the image displayed on the HMI.
FIG. 5 is a calibration raster for the SLTS.
FIG. 6 is a representation of the working principle of the simultaneous laser targeting unit (SLTU).
FIG. 7 is a representation of the sensor array of a processing unit.
DETAILED DESCRIPTION OF THE INVENTION
In all drawings:
1 Simultaneous Laser Targeting equipment (SLT) 2 Simultaneous Laser Targeting Unit (SLTU) 3 Video Camera (VC) 4 Laser Control Camera (LCC) 11 , 12 , 13 —Processing Units (PU) 101 , 102 , 103 , 104 —Target Objects (TO) 201 , 202 —Neutral Objects (NO) 100 —Computer 99 —Human Machine Interface (HMI) 501 —SLTU Controller 511 —Laser 512 —Laser Control Unit 521 —Rotating Mirror 522 —Horizontal Servo Motor 523 —Vertical Servo Motor 601 , 602 , 603 , 604 —Guiding Sensors 605 —Selector Sensor
FIG. 1 is a general view of the application of the invention as a targeting system.
From a multitude of objects, 101 — 104 are selected as target. The rest of the objects— 201 and 202 —are considered neutral and are not targeted.
Targeting is executed by 1 , the SLT.
The simultaneous laser targeting equipment 1 (SLT) has as components the simultaneous laser targeting unit 2 (SLTU), the video camera 3 (VC) and the laser control camera 4 (LCC).
The video camera 3 (VC) observes the field and delivers the input to the system. The information given by video camera 3 is processed by computer 100 —a computer with image recognition software and at least one database, or a human operator 99 , to select the targets and the procedure to apply to each selected target.
The targets are marked by the simultaneous laser targeting unit 2 (SLTU) and discrete information is sent via the laser to each target. The laser control camera 4 reads the reflected targeting information, and helps to make adjustments and corrections if necessary. It may be thought of as closing the control loop for targeting.
The reflected laser beam's coded information is read by the processing units 11 , 12 and 13 . These units can be simply pre-programmed, like processing unit 12 , or they can communicate with computer 100 or other computers, either hard-wired like 11 or wireless like 13 . Processing units having a SMART-type of guiding system can use the reflected signals as a beacon, selecting their own targets and applying the required processing to them, in accordance with the laser beam's decoded information and controls.
FIG. 2 is an image of the processing area with the marked objects 101 , 102 , 103 , 104 and the neutral objects 201 , 202 . It is the image captured by the video camera 3 , the input for the targeting system.
FIG. 3 is the image captured by the laser control camera 4 , the actual feed-back.
FIG. 4 is the combined image of the VC 3 and LCC 4 , as actually displayed on the HMI display 99 . This is what the human operator sees on his display.
FIG. 5 is a calibration raster to align the SLTU, VC and LCC. The idea is similar to the aligning of touch-screens. Corrections are made in the controls, until the 4 corners and the center of all 3 images—video 3 , marking 2 and feed-back 4 —are perfectly aligned.
FIG. 6 is a representation of the working principle of the SLTU 2 . It operates similarly to the working principle of laser-printers, but it uses a different type of laser—one compatible with smart guiding systems—and the laser is oriented towards external targets. The laser is not used to discharge an electrostatically charged film, as in a laser printer. Instead, in the present invention, it transmits and projects an information package to the targets.
The SLTU controller 501 receives the targeting information from the computer 100 . It controls the elevation and azimuth of the laser beam by tilting and rotating the mirror 521 with the help of the vertical and horizontal servo-motors 523 and 522 .
The laser beam does not have to scan pixel by pixel the whole visual field, like a full page in printing. Instead, it can be oriented directly to the coordinates, one target after the other, repeatedly. There being no need for a full scan, it is possible to achieve a high repetition rate, making the marking of a plurality of targets virtually simultaneous. The 501 is sending the coded information to the laser control unit 512 , which is commanding the laser gun 511 .
FIG. 7 is a representation of the sensor array of a processing unit. The processing unit reads the reflected information with the selector sensor 605 .
If there is a match, it aligns itself on the target and approaches it using the guide sensors 601 , 602 , 603 and 604 . Otherwise, if there is no match, the processing unit searchs for another target, until it finds its own.
As military applications of the present invention include targeting systems, which can be improved considerably, from UAVs and anti-tank systems to ICBM defense, so called anti-rocket rocket systems, or the ‘Star Wars’ defense system.
This type of marking can also be used in non military applications, such as in a robotic production environment, internet surgery, unmanned vehicles or a multiple axis CNC machine.
It will be appreciated by those of ordinary skill in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein. | A novel method and system is provided for simultaneous, non-invasive and non-contact marking for processing of targeted objects. The viewing, selection, marking, processing and feed-back is substantially simultaneous and computerized. | 5 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The invention relates to logistics and supply chain management. Specifically, the invention relates to scheduling loads for vehicles with compartments to fulfill the demand of target locations.
[0003] 2. Background
[0004] Logistics often involves the transportation of goods and services from a source location to a destination location. The transportation services for this movement of goods and services may be provided by transportation services providers (e.g., DHL or UPS), a manufacturer, retailer, distributor or similar entity. The transportation of goods and services is often employed in the process of supply chain management.
[0005] A supply chain is a network of retailers, distributors, transportation service providers, warehouses, and suppliers that take part in the production, delivery and sale of a product or service. Supply chain management is the process of coordinating the movement of the product or service, information related to the product or service, and money among the constituent parts of a supply chain. Supply chain management also integrates and manages key processes along the supply chain. Supply chain management strategies often involve the use of software to project and fulfill demand and improve production levels.
[0006] Logistics is a subset of the activities involved in supply chain management. Logistics includes the planning, implementation and control of the movement and storage of goods, services or related information. Logistics aims to create an effective and efficient flow and storage of goods, services and related information from a source to the target location where the product or source is to be shipped to meet the demands of customers.
[0007] The movement of goods and services through a supply chain often involves the shipment of the goods and services between the source location at which the product is produced or stored and the target location where the product is to be shipped such as the wholesaler, vendor or retailer. The shipment of products involves a vehicle such as a truck, ship, train or airplane and involves the planning of the arrangement of the products to be shipped in the vehicle.
[0008] The shipment of goods may involve complex constraints. Supply chain management systems are limited in their ability to simulate the loading of a vehicle while ensuring adherence to a complex set of constraints. For example, supply chain management systems are unable to maximize the use of vehicles, especially vehicles with multiple compartments.
SUMMARY
[0009] Embodiments of the invention include a system for scheduling goods for a set of vehicles for shipment. The scheduling system may include a compartment scheduling module. The compartment scheduling module may be used to determine which compartments of a vehicle a good may be scheduled to. This scheduling may include evaluating a set of constraints on the shipment. The constraints may include a complex logical statement and be based on the requirements of the routing, goods, compartment and vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that different references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
[0011] FIG. 1 is a diagram of one embodiment of an order replenishment management system.
[0012] FIG. 2 is a diagram of one embodiment of a vehicle scheduling system for vehicles with compartments.
[0013] FIG. 3 is a flowchart of one embodiment of an assignment process of a compartment determination module.
[0014] FIG. 4 is a diagram of one example embodiment of a compartmentalized vehicle.
[0015] FIGS. 5 (A)-(G) are diagrams of example functions for compartment utilization.
[0016] FIG. 6 is a flowchart of one embodiment of a process for constraint checking.
[0017] FIG. 7 is a diagram of one embodiment of a user interface for the scheduling system.
DETAILED DESCRIPTION
[0018] FIG. 1 is a diagram of an order replenishment management system. Order replenishment system 100 may be utilized in a supply chain to manage the movement of goods between source locations and target locations. A source location may be any location in a supply chain that may provide a product or similar items. A target location may be any location in a supply chain that may receive a product or similar items. A single location may be both a source and target location dependent upon the context. For example a factory may be a source location that ships products to a warehouse or similar location. The same factory may be a target location for receiving component parts for a product assembled at the factory. Similarly, other locations including warehouses, distribution centers, retailers and similar locations may be either a source or target location dependent on the shipping context. The embodiments discussed herein primarily use an example where a factory or warehouse is the source location and the end user or retailer is the target location for sake of clarity. One skilled in the art would understand these are examples of target and source locations and other target and source locations may be used.
[0019] In one embodiment, an order replenishment management system 100 may receive sales data, inventory data from retailers, inventory data from warehouses or similar demand data. Order replenishment management system 100 may then generate orders for shipments of products from source locations like factories and distribution centers to meet the demand generated by customers or end users. In one embodiment, order replenishment management system 100 receives sales, inventory or similar demand data from a set of retailers, warehouses and similar sources (block 101 ). The demand data may be received at regular intervals (e.g., days, months and similar time intervals).
[0020] The demand data that is received from the retailers, warehouses and similar sources is processed to predict the future or current demand for a set of products. As used herein the term “set” may include any number of items including a single item. The projected demand for a set of products may be for any time period (e.g., a month, week, day, hour or similar measurement of time). The projected demand may also include a prediction of demand for subdivisions of the time period of the projection. For example, a projection of demand for a month may have a breakdown of that demand on a day by day or week by week basis.
[0021] The projected demand data may be used by a vehicle scheduling system to determine the best manner of transporting a set of products to a target location (block 103 ). The determination of a route for sending products to the target location may involve the analysis of the availability of demanded products at various source locations, the cost of shipping the products from the source locations to the target locations, the utilization of the capacity of a vehicle for shipping the products from the source location to the target location and the types and capacity of the compartments of the vehicle.
[0022] The determination of the vehicle schedule may include a simulation of building a load (e.g., a shipment of products) in a vehicle. The building of a load may involve consideration of the size, weight, product types and similar characteristics of a shipment. The loading of the shipment into a vehicle may be required to meet a set of constraints. For example, the vehicle may have a weight limit and a volume limit, certain products may not be properly shipped in the same vehicle as other products and similar shipping constraints may be a part of the loading simulation. This simulated load may also be applied to compartments within a vehicle. Each compartment may have weight, volume, pallet limits or similar capacity limits. Some compartments and vehicles may have restrictions on the type of products that can be shipped within them (e.g., freezer compartments may not store items that cannot withstand cold temperatures). Further restrictions may include the incompatibility of certain products with one another such that they cannot be shipped in the same compartment or vehicle. Any combination of constraints may be considered in determining a load for a shipment or compartment.
[0023] The vehicle scheduling generates a set of transportation orders. Each transportation order indicates a set of goods to be transported from a source location to a target location. Each transportation order may be assigned to a specific vehicle or a set of vehicles by a transportation determination module. The transportation order may be further assigned to a compartment of a vehicle or across multiple compartments of a vehicle. The assignment of products to compartments may be represented as a compartment configuration data structure. A transportation plan may include a set of transportation orders assigned to vehicles, routing stops for a vehicle, a route schedule with start and end times for activities (e.g., deliver, rest or similar activities) and similar information.
[0024] After the transportation orders for shipping the products are determined, fulfillment instructions may be sent out to the origination site (block 105 ). The shipping and fulfillment instructions may be sent electronically to the source location. In one embodiment, the loading simulation and transportation orders are determined at a central server node. The shipping and fulfillment instructions or the vehicle schedules, transportation orders or compartment configuration data structures themselves may be sent to a remote node at the source location through a network or similar communication system.
[0025] FIG. 2 is a diagram of one embodiment of a vehicle scheduling system for vehicles with compartments. In one embodiment, the scheduling system 200 may include a server node 201 , target location node 221 and source location node 223 . Server node 201 may be a single central server, a set of servers sharing the scheduling tasks or similar system. The scheduling system 200 may include multiple target location nodes 221 or multiple source location nodes 223 .
[0026] In one embodiment, target location node 221 may include a sales or inventory database 231 . The sales database 231 tracks the sales of a retailer, vendor, warehouse or similar source of demand. The inventory database 231 tracks the inventory levels of the products supplied by the scheduling system 200 . Target location node 221 may be in communication with server node 201 through a network 219 , point to point link or similar communication systems.
[0027] In one embodiment, source location node 223 may include an inventory database 225 . The inventory database 225 tracks the inventory levels of the products to be supplied by the scheduling system 200 . Source location node 223 may be in communication with server node 201 through a network 219 , point to point link or similar communication systems.
[0028] In one embodiment, server node 201 may include a communication device 217 to receive demand data including sales data or inventory data from the target location node 221 through network 219 or similar communications system. Communication device 217 may be a modem, network card or similar communications device.
[0029] In one embodiment, the incoming sales and inventory data may be processed by a demand determination module 227 . Demand determination module 227 may utilize the data supplied by target location node 221 to generate a set of demand orders that may be stored in a demand order module 205 . In one embodiment, incoming demand data may include various types of data, such as demand related to special promotions, demand for common product restocking or similar data. Demand determination module 227 or similar module may adjust, filter or sort data according to type to prevent skewed demand orders or generate demand orders for a specific type of product demand. The demand determination module 227 may be a component of a demand determination system that includes demand projection and similar functionality. In another embodiment, demand determination is a separate system from the vehicle scheduling system.
[0030] In one embodiment, demand order module 205 may be a data structure that stores and tracks a set of products for which demand has been predicted by demand determination module 227 . For example, demand determination module 227 may determine that one hundred units of a product should be shipped to a destination (e.g., a retailer, warehouse or similar destination) each week and that fifty of the product units should be shipped on a Monday and ten units should be shipped Tuesday through Saturday to meet the projected demand.
[0031] In one embodiment, transportation determination module 203 may be an application that schedules the loading of a set of vehicles with a shipment of products (e.g., generates transportation orders) based on demand data from a demand order module. For example, a transportation determination module 203 may be used to determine how the fifty units of the Monday shipment will be scheduled onto a set of vehicles. In one embodiment, transportation determination module 203 may work in conjunction with or call on the services of a compartment determination module 251 . Compartment determination module 251 may determine whether a set of products of a transportation order tentatively assigned to a vehicle can be loaded into the compartments of the vehicle while meeting the constraints of these compartments and the products in the transportation order. The transportation determination module 203 and compartment determination module 251 may be utilized in conjunction with any type of vehicle (e.g., a ship, airplane, truck, train or similar vehicle) or object that moves or is capable of being moved and the compartments of such vehicles and objects.
[0032] In one embodiment, transportation determination module 203 may work in connection with a constraints module 253 when determining the loading of the set of vehicles. Constraints module 253 may be a data structure that includes a set of shipping rules or other constraints on the shipping of products using a set of vehicles. Shipping rules and constraints may include limitations on the combinations of certain products in a single transport, weight limitations of a transport, size of a transport, default shipment configurations, number of transportation orders per transport, combination of demand orders or products from different sources and similar data. Similarly, compartment determination module 251 may utilize the constraints module 253 to determine constraints applicable to compartments and apply these constraints to product configurations for the compartments. In addition some constraints may be specific to compartments, such as compartment type, number of transportation orders per compartment, combination of products, demand orders or products from a particular source in a compartment and similar constraints.
[0033] In one embodiment, the transportation determination module 203 and compartment determination module 251 may attempt to create “full” loads by maximizing the utilization of the capacity of a set of vehicles and each compartment in each vehicle used for shipping. Maximizing the utilization of a set of vehicles and their compartments can reduce the per item or unit shipping costs. Maximum utilization may be measured in any appropriate manner such as the number of shipping units or pallets that a vehicle or compartment may carry, the weight limit a vehicle or compartment may carry, the volume of goods that a vehicle or compartment may carry or by use of similar criteria. Maximum utilization may mean that the carrying capacity is used to its fullest extent (e.g., it has met its weight limit or its volume limit or shipping limit) or falls within an acceptable range (e.g., ±1000 pounds of the vehicle or compartment weight limit). This range may be defined to suit the needs of the order replenishment system or user. The range of acceptable “full” loads may be characterized as having a maximum bound and minimum bound.
[0034] In one embodiment, the transportation determination module 203 and compartment determination module 251 may not fill all of the vehicles to a maximum capacity for technical, business, logistical or similar reasons. A false or temporary maximum capacity may be used in place of an actual maximum capacity. In one embodiment, the false maximum capacity may be used as a default loading goal. Transportation determination module 203 and compartment determination module 251 may load some of the vehicles or compartments only up to the false maximum capacity to leave room on a transport to accommodate a product that may be added at a later date or stop, leave room to maneuver products during unloading or for similar reasons. The number of vehicles which are filled up to the false maximum capacity may be kept at a minimum. Similar alterations and accommodations may also be implemented to the capacity characteristics of vehicles and compartments.
[0035] In one embodiment, the compartment determination module 251 may be separate from the transportation determination module 203 to facilitate the addition of the compartment determination module 251 to existing vehicle scheduling systems that do not support compartment determination. Minimal changes to these systems may be required as the compartment determination module 251 may operate largely transparently to the other modules by creating a compartment configuration data structure without disturbing other data structures. In one example, the transportation determination module 203 may be modified to call the compartment determination module 251 to filter out infeasible transportation orders, which may then be excluded from transportation plans. In another embodiment, the transportation determination module 203 may be integrated with the compartment determination module 251 .
[0036] When the desired load configuration has been determined by the transportation determination module 203 the results may be sent to a shipping and fulfillment module 207 . Shipping and fulfillment module 207 may generate a formatted set of loading configurations or instructions. Shipment and fulfillment module 207 may then output the loading configurations and instructions in the form of a load order or similarly formatted data or modules to source location node 223 . In one embodiment, the load configuration instructions may be saved in the form of a compartment configuration data structure. This module may be a formatted file or data structure indicating the organization of transportation orders and products amongst a set of vehicles and compartments. The shipment instructions may be sent through a communication device 217 over a network 219 or similar communications system. Source location node 223 may be located at a source location such as a factory, warehouse or similar product source location.
[0037] In one embodiment, the vehicle scheduling system 200 may include a user interface module 209 . The user interface module 209 may provide an interface for a user such as an administrator or other user (e.g., a transportation planner or similar user) to view transportation orders, transportations plans, compartment configuration data structures and similar data. The user interface may also allow editing of these data structures and the setting of related characteristics, constraints and similar data.
[0038] In one embodiment, the vehicle scheduling system 200 may include a serialization module 211 . The serialization module 211 may transform a transportation plan or set of transportation orders into a format where they can be analyzed by the compartment determination module 251 . The compartment determination module 251 may process transportation orders one at a time as it determines the assignment of transportation orders to a compartments using a compartment configuration data structure. The serialization module 211 may be used to provide transportation orders to the compartment determination module 251 one at a time from an already created transportation plan or a set of transportation orders.
[0039] In one embodiment, the modules of vehicle scheduling system 200 are a set of software instructions, data structures, electronic devices or similar implementations. In one embodiment, the data structures and instructions may be constructed using an object oriented paradigm or similar implementation. In one embodiment, the instructions and data structures are stored on a storage device 213 . The instructions may be executed or the data structures loaded by a set of processors 215 . The set of processors may utilize a system memory 233 .
[0040] FIG. 3A is a flowchart of one embodiment of a process of a compartment determination module. The assignment of transportation orders to a compartment involves an optimization problem. Any type of optimization algorithm may be utilized in solving this optimization problem. For example, a local search, a tabu search, simulated annealing, evolutionary algorithms or other metaheuristics may be used. Also, mixed integer linear programming, constraint programming and other exact techniques or derived methods that may involve backtracking may be employed.
[0041] The flowchart sets forth the general functions that a compartment determination module may employ. The compartment determination module may receive a set of transportation orders from a transportation determination module (block 351 ). The compartment determination module acts as a filter to test and discard configurations of the products based on the transportation orders that are not feasible. The compartment determination module determines a placement or configuration of all items from the transportation orders (block 353 ). The compartment determination module then determines if these configurations meet the constraints on the vehicle, products, compartments and similar constraints (block 355 ). If the configurations do not meet the constraints they may be discarded (block 357 ). If the configurations do meet the constraints then they may be kept (block 359 ). The valid configurations may then be analyzed to determine an optimum configuration.
[0042] FIG. 3B is a flowchart of one example embodiment of a process of a compartment determination module. In one embodiment, the process may be initiated by a transportation determination module that calls the compartment determination module. The transportation determination module may provide a transportation order, set of transportation orders, a product or set of products that are to be placed on a vehicle (block 301 ). The compartment determination module determines whether products in the transportation orders or separate products may be assigned to a compartment of a vehicle. The transportation determination module can use this information to determine the best scheduling of all transportation orders to available vehicles by filtering out transportation orders that require configurations that are not feasible because of incompatibilities related to the compartment configuration of the vehicles.
[0043] In one embodiment, the compartment determination process is incremental and handles a single addition or a set of additions prior to placing a subsequent product or set of products. This embodiment may be referred to as a ‘greedy’ algorithm that assigns products to the first available space found. This algorithm may be most efficient in scenarios where there are not large numbers of restrictions on products, vehicles and compartments. In these scenarios other algorithms may be more efficient including local search algorithms or similar algorithms. In other embodiments, other types of algorithms and process may be used. This implementation is provided by way of example. One skilled in the art would understand that other implementations are within the scope of the contemplated invention.
[0044] In one embodiment, the process selects a first compartment of a vehicle that the transportation order has been assigned to (block 303 ). In one embodiment, the process may start with an empty compartment, vehicle and plan. The process may try each compartment in any order, for example the process may proceed from the back to the front of the vehicle, front to back, side to side, in order of descending size or similar order. In another embodiment, the compartment may be selected from a group of compartments that are distributed across multiple vehicles, vehicles and trailers or additional structures. A transportation order may be split across any number of compartments. The selection of a compartment may be set in a preferred order, based on type of compartment, based on size of compartment or similarly ordered. The order or criteria for determining order may be set by a user, administrator or similar entity. The received transportation orders may have been processed for cost efficiency at the vehicle level prior to testing at the compartment level.
[0045] FIG. 4 is a diagram of one example embodiment of a set of compartments associated with a vehicle. In the example, the vehicle 400 has at least three compartments 401 , 403 and 405 dependent on configuration. Each compartment may be of the same or different type. For example, a compartment may be temperature controlled, airtight, weatherproof, or have similar characteristics. The first compartment 401 may be a fixed compartment. The fixed compartment has a fixed capacity in terms of size, number of pallets it can accommodate, maximum weight, dimensions and similar measures of capacity. The entire compartment may be utilized for placing products. If, however, less than the full size of a compartment is used then vehicle capacity cannot be maximized. In other words, the capacity of the vehicle is consumed by a fixed amount.
[0046] In the example, the middle compartment 403 has a variable size with fixed or defined increments. This type of compartment may be referred to as a fixed increment adjustable compartment. The size and dimensions of the compartment may be adjusted by moving at least one wall of the compartment. The wall may be positioned only at set places that may be uniform or non-uniform in spacing. In one embodiment, a single wall of a compartment may be moved over fixed increments. In another embodiment, multiple walls of the compartment may be adjusted. If less than the maximum size of the compartment is required to store products, then the size of the compartment may be reduced to conserve the capacity of the vehicle and make that capacity available in other compartments. However, the capacity of the compartment can only be reduced based on fixed increments. As a result, some capacity may be left unused. For example, if one wall can be adjusted in five foot increments with a minimum length of five feet and a single product six feet in length is placed in the compartment, then four feet of compartment may go unused. A fixed increment adjustment compartment may also be enlarged by fixed increments dependent on the overall capacity of the vehicle and other compartments and availability of positioning attachments.
[0047] The fixed increment adjustment compartment may have any capacity including any size or dimension. The fixed increment adjustment dimension may be any size and any number of adjustment positions may be provided. Any number of walls may be adjusted. A fixed increment adjustment compartment may have any position in a vehicle and have any compartment characteristic (e.g., a freezer compartment, airtight compartment or similar characteristic).
[0048] In the example, the third compartment 405 is a variable size compartment. This compartment is similar to the second compartment 403 , but does not have fixed adjustment increments. Thus, this compartment can be adjusted to approximately the size of its contents dependent on the shape and placement of the contents. A single wall 411 may be adjustable or any number of walls may be adjustable. The variable sized compartment 405 may have any position in a vehicle and have any characteristic (e.g., a freezer compartment, airtight compartment or similar characteristic).
[0049] In one embodiment, a vehicle may have restrictions on the placement of variable adjustment and fixed adjustment compartments. For example, a side door 409 or similar structure may prevent a wall 411 from being placed in certain positions in the vehicle. A fixed adjustment compartment or variable adjustment compartment may encompass such restrictions (e.g., include a side door), but will have certain positions or capacity ranges that are not available.
[0050] As discussed above, compartments may have defining characteristics, such as temperature control, weatherproofing, airtight and similar characteristics. These characteristics may define categories of compartments, such as freezer compartments, gas tanks and similar categories of compartments. Products have similar defining characteristics such as temperature needs, gaseous, liquid, types of containers and similar characteristics. These characteristics may define categories of products, such as fuels, frozen items and similar categories. As is discussed further below these categories may be used to determine the compatibility of products and compartments.
[0051] Returning to a discussion of FIG. 3 , the selection of a compartment may also include the adjustment of a capacity of a compartment. For example, if a previous check indicated it was not feasible to put an item in a first compartment and the compartment has an adjustable capacity, then the capacity of the compartment may be expanded and the check for feasibility run again. If the compartment has a fixed adjustment size then the next larger size may be checked. If the compartment has a variable size then the compartment may be increased in capacity based on the size of the product to be placed in it. The capacity adjustment may also take into account restrictions on the placement of walls and the overall capacity of the vehicle.
[0052] FIGS. 5 (A)-(G) are diagrams of example functions of the change of occupied capacity of a vehicle over the process of placing products in the compartment. In each figure, the x-axis is the increase in placed products (load) in a compartment. The y-axis is the amount of capacity occupied in the vehicle.
[0053] In FIG. 5(A) a function for a standard compartment is depicted. The occupied capacity of the vehicle increases over each iteration of the process. This function assumes an infinite capacity for the compartment. There are no restrictions on the compartment, thus the occupation of the capacity of the vehicle may be based on the volume, weight, number of products, number of pallets or similar measurement of occupied capacity for the vehicle. This utilization may be expressed by the f(x)=x, where x represents the consumed capacity of a vehicle. FIG. 5(B) is a diagram for a standard compartment of a finite size. This example is similar to the previous standard vehicle figure, except that an upper bound 501 is present that restricts the increase in occupied capacity at a maximum capacity for the vehicle or compartment. This utilization may be expressed as f(x)=x for x<=u, where u is the upper bound.
[0054] FIG. 5(C) is a diagram of an example function for a compartment with fixed adjustments for its walls. The space 503 below the first line indicates a minimum compartment size and the space 505 between the remaining lines indicates the increment size. Products are placed into a compartment until they exceed the size of the minimum compartment size. Then the compartment is increased by a set increment creating a gap in occupied capacity in the vehicle, because the compartment utilizes this space even if a product is not placed into the space, thereby creating scenarios that may waste space. This utilization may be expressed as f(x)=s 1 for x<=s 1 ; f(x)=s 2 for s 1 <x<=s 2 , etc. where s 1 , s 2 . . . represent the fixed adjustment sizes. FIG. 5(D) is a diagram of an example function similar to the previous example except that the vehicle or compartment has a maximum capacity 501 . The compartment in the vehicle may be continually expanded until it reaches a maximum capacity. This utilization may be expressed as f(x)=s 1 for x<=s 1 ; f(x)=s 2 for s 1 <x<=s 2 , such that f(x)<=the upper bound.
[0055] FIG. 5(E) is a diagram of an example embodiment where the compartment has a fixed minimum size, but is variably adjustable beyond its minimum size. Products are placed into the compartment, which has a fixed minimum size until the capacity of the minimum sized compartment is exceeded. The compartment is then expanded as it is filled. This utilization may be expressed as f(x)=s 1 for x<=s 1 ; f(x)=x for x>s 1 . FIG. 5(F) is a diagram of an example similar to that of the previous figure except that a maximum capacity of the vehicle or compartment limits the continued addition of products to the compartment to a maximum capacity. This utilization may be expressed as f(x)=s 1 for x<=s 1 ; f(x)=x for s 1 <x<upper bound.
[0056] FIG. 5(G) is a diagram of one embodiment of a complex function for a compartment. This complex scenario shows the following function: f(x)=0 for x=0, f(x)=2 for 0<x<=2, f(x)=x for 2<x<=4, f(x)=6 for 4<x<=6, f(x)=x for 6<x. In one embodiment, the function may represent a scenario where the separator for the compartment can be placed such that the vehicle consumption is 0. After a first product is loaded into the compartment, the vehicle consumption is at least 2. This may model a “frozen” compartment in a vehicle that has a side door to load/unload the frozen goods. As soon as the first product is placed into the compartment (e.g. one pizza), the separator must be moved and not obstruct the door such that we can open the door and access the frozen goods. In this example, there may be a second side door. The separator may be placed anywhere between the two doors, but it must not be put in the range covered by the 2nd door. Beyond the second door, the separator may be placed anywhere.
[0057] Returning to a discussion of FIG. 3 , in one embodiment, after the compartment selection process has completed then a test may be conducted to determine if the compartment meets all of the constraints associated with a product to be placed in the compartment (block 305 ). FIG. 6 is a flowchart of one example embodiment of a process for determining if constraints on a product being placed in a compartment are met. The example embodiment encompasses a few example constraint checks. One skilled in the art would understand that other constraints may be chained together using basic or complex logic in place of or in combination with the example constraints.
[0058] In one embodiment, the constraint checking process may receive a proposed configuration for a compartment with a product derived from a transportation order (block 601 ). This configuration may include previously placed products within the compartment, the status of the compartment in regard to capacity, the category of the compartment, the category of the product and similar factors.
[0059] In one embodiment, the process may check the configuration and product to determine if the product is compatible with the compartment (block 603 ). A product may need to be in a compartment with specific characteristics or of a certain category. For example, a product may need to be within a defined temperature range and thus within a refrigerator compartment or similar compartment. Other characteristics or categories of a compartment may include airtight, weatherproofed, heated, cushioned or similar characteristics. Similarly, a product may be checked to determine if it is compatible with the vehicle as a whole. Certain categories of products may not be transported on certain categories of vehicles. For example, a frozen pizza may not be transported on a fuel tanker. If the constraint is not met then the process may indicate that the configuration is not feasible (block 613 ). If the constraint is met then the next constraint may be tested.
[0060] In one example embodiment, the configuration and product may be tested to determine if the product is compatible with other products in the compartment (block 605 ). Certain categories of products may be incompatible with one another. For example, a fuel truck may have multiple airtight compartments (i.e., tanks). A diesel fuel may be loaded into a first tank but not fill it. However, another fuel such as gasoline may not be loaded into the same compartment. Any type of incompatibility may be tested including temperature, mixture, container or similar types of incompatibility. If any other product in the compartment or category of product is not compatible with the product to be placed or the category of product to be placed the process may indicate that the configuration is infeasible (block 613 ). If no incompatibility is detected then the next constraint may be tested. Similarly, a check may be made to determine if a product or category product to be placed is incompatible with another product or category of product on the vehicle.
[0061] In one embodiment, a test may be made to determine if the product placement in the compartment would cause the compartment's capacity to be exceeded (block 607 ). This check may encompass a check of the weight of the product against the weight limit of the compartment taking into consideration the already placed products, a check of the dimensions of the product or similar tests of the capacity of the compartment. If the compartment does not have sufficient capacity then an indication may be returned that the configuration is not feasible. For example, the load of the compartment may be represented as l(C), which is the total of all transportation orders put in the compartment C. A capacity check of the compartment may be represented as l(C)<=capacity(C). In one embodiment, if the compartment has a variable size then the compartment size may be increased and the compatibility rechecked or the capacity may be increased on a subsequent iteration. If the product does not exceed the capacity then further constraints may be checked.
[0062] In one embodiment, a check may be made to determine if the capacity of the vehicle is exceeded by the placement of the product (block 609 ). A product may cause the overall vehicle capacity factoring in the other products already placed. The product may exceed the vehicle capacity in terms of space, weight or other measurement of capacity. The formula f(x,C) may represent the reduction of the vehicle capacity caused by load x of the compartment C. A check of the vehicle capacity may be
[0000]
∑
C
f
(
l
(
C
)
,
C
)
≤
capacity
(
V
)
,
[0000] where V represents the vehicle. Each compartment could have a different function f(x,C) and each compartment may have a different function per loading dimension. For example, if a vehicle has m compartments and n dimensions total, then the vehicle may be represented by m*n functions. If the capacity is exceeded then the process may return an indication that the constraints have not been met and the configuration is infeasible. If the capacity is not exceeded and all constraints have been met then the process may return an indication that the configuration is feasible (block 611 ).
[0063] Returning to the discussion of FIG. 3 , the scheduling process receives the indication from the constraint checking process and records that the configuration is feasible (block 307 ) or proceeds toward a path that will check the next configuration. If the constraint is not met, a check may be made to determine if the last compartment on the vehicle has been checked (block 313 ). If further compartments are present then the next compartment is selected and the process continues to check the next configuration. Similarly, the next configuration may be to check the same compartment with changed characteristics such as increasing the capacity by adjusting the walls of the compartment if it is a variable sized or fixed increment adjustable compartment.
[0064] If the end of the vehicle, the last compartment or the last permutation of the compartment characteristics has been tested then the process determines that the product placement on the vehicle is not feasible (block 315 ). The transportation determination module may receive this indication and generate a new set of transportation orders or configurations to be tested that exclude the assignment that lead to the determination of infeasibility by the compartment determination module.
[0065] If the constraints are met the configuration may be labeled or marked as feasible (block 307 ). This indication may be used to identify configurations or partial configurations that are workable and may be used or compared to one another to find an optimal scheduling. In one embodiment, in addition to or in place of marking a configuration or transportation order as feasible the compartment determination module may generate a score for the configuration or transportation order. The score may indicate the utilization of the capacity of a compartment or vehicle. The score may be used to select the best configuration from amongst a set of feasible configurations.
[0066] The configuration may be stored for future use or modification in the next iteration (block 309 ). The process may continue and check to determine if additional products are to be added to the current configuration (block 311 ). If further products are to be added then the next item may be received or selected (block 301 ) and the process continues to iterate until it is determined to be infeasible (block 315 ) or all the products are placed in the configuration and the complete configuration is stored or returned (block 317 ). This process may be used to evaluate multiple configurations serving as a filter for proposed configurations that are not compatible with the compartment configuration of the vehicle or set of vehicles.
[0067] In the example process described above a ‘greedy’ algorithm is employed to assign products to the first available space. In other embodiments, local searches or similar processes may be used to assign the products to the compartments and vehicles. The configuration of products may be redistributed with each added product or after all products have been assigned using a search function to optimize the utilization of capacity and increase the likelihood of finding a feasible solution. In one embodiment, a user, administrator or similar entity may select a heuristic for the search and optimization program.
[0068] FIG. 7 is a diagram of one embodiment of a user interface for the vehicle scheduling system. The user interface may be used to monitor the scheduling process, view the results of the process, adjust the settings of the process, rescheduling products or transportation orders and similar functions.
[0069] The user interface 701 may include a listing of vehicles 717 . The listing may also include trailers or sub-sections of the vehicles. For example, with a train each box car may be listed. The user interface may also include a display of transportation orders organized by vehicles, sub-sections and compartments. The vehicles, sub-sections and compartments may be organized in a hierarchy. The hierarchy may be shown as a set of nested items. For example a truck 703 may be shown in the display. Information about the truck may be provided including the source location 711 and the destination location 713 . Each trailer 709 and compartment associated with a truck may be listed. Each trailer and compartment may have an assigned name 705 and type 707 displayed. Other information may be displayed including the category, source 711 , destination 713 and similar information.
[0070] In one embodiment, transportation orders 715 may be grouped under each assigned compartment. Transportation order information may also be displayed including the category, type 707 , name 705 , source 711 , destination 713 and similar information about the order.
[0071] The data may be sorted, rearranged or similarly manipulated. The user interface may also provide menus for setting the configuration of the transportation determination module and processes as well as the compartment determination module and processes. Transportation orders, compartments, sub-sections and vehicles may be rearranged and regrouped by dragging and dropping or similar interface mechanism.
[0072] In one embodiment, the scheduling system including the compartment determination module may be implemented as hardware devices. In another embodiment, these components may be implemented in software (e.g., microcode, assembly language or higher level languages). These software implementations may be stored on a machine-readable medium. A “machine readable” medium may include any medium that can store or transfer information. Examples of a machine readable medium include a ROM, a floppy diskette, a CD-ROM, a DVD, flash memory, hard drive, an optical disk or similar medium.
[0073] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. | Embodiments of the invention include a system for scheduling the shipment of a set of products. The shipment may be loaded into a set of vehicles and further configured to fit a set of compartments on those vehicles. The system may include attempts to fill each vehicle and the compartments of each vehicle. The system may include evaluating a set of constraints on the shipment. The constraints may include a complex logical statement. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention, in general, relates to soffit or foundation vents and, more particularly, to vents that close when a predetermined temperature threshold is exceeded.
Current fire codes allow for soffit types of attic vents or for foundation vents, to include a one-quarter inch mesh. This dimension is intended to keep birds or animals from entering through the vent. Soffit vents are disposed under the eaves of buildings (homes or commercial) and foundation vents are disposed through the concrete foundation walls that support a building structure.
Most homes (and some businesses) that catch on fire from wildfires that approach the structures are ignited by embers that fall either on the roof of the home (or business) or by embers which are able to enter the structure by their passage through an attic soffit vent.
Attic soffit vents allow for the passage of air and are useful in cooling the attic area during hot days or when the roof is exposed to direct sun. As such, together with warmed air they facilitate the creation of a draft. While the draft is normally desirable, during a nearby fire, the draft can permit embers to pass through the vent and ignite the structure somewhere in the attic area.
Even more troublesome, during a fire temperature differentials are apt to become excessive as ambient air is heated by the flames and this will create exceptionally powerful drafts that can convey embers through the mesh and into the attic with great force. As a result, even larger embers or other similarly sized objects that might not normally be able to pass through the mesh during a more standard amount of draft are able to enter during the increased draft produced by a fire. The strong draft is able to break apart larger embers that come in contact with the mesh and draw them into the attic space.
It is important to note that when there is the greatest amount of danger to the structure, such as during a nearby fire, the very nature of the vent which is to utilize and create draft is also increased at that time, and this capability is contrary to the needs of a homeowner because it aggravates what is already a potentially dangerous situation.
Additionally, when the structure is ignited from a location in the attic it is especially difficult, if not impossible, for firefighters to apply water to it until the entire structure has been engulfed in flames and substantially destroyed. It is much easier to detect and extinguish a glowing ember or small fire on the roof where it is both visible and readily accessible to firefighting efforts.
It is desirable to automatically close an attic vent whenever a sufficient increase in ambient temperature occurs beyond a threshold amount. In this situation, it is assumed that a fire, such as that caused by a wildfire or a nearby structure that may be ablaze, is what is elevating the temperature.
Warm air will begin to pass through the attic vent as the ambient temperature rises which will also warm the vent. As the fire approaches closer to the structure the danger of entry of a hot ember through an open attic vent also increases. Before this can occur, a significant temperature rise of the ambient air passing through the vent will have first occurred.
It is desirable to automatically close the vent if the temperature of a portion of the vent rises a sufficient amount so as to exceed a first threshold, thereby blocking the passage of air through the vent. It is desirable to again automatically open the vent when the temperature falls to below that of a second threshold, thereby again permitting the passage of air through the vent. The second threshold would include a temperature that is sufficiently far below the first threshold so as to ensure that no remaining fire danger existed.
While it may be possible to provide a self-destructing type of vent that effectively blocks the passage of air when the first threshold temperature amount is exceeded, such a device must be discarded and replaced if it is activated. This is both time-consuming and expensive.
The same need applies also for foundation vents that are used to vent crawl spaces under a structure or basement areas. Flammable materials are likely to be stored or found in either of these areas as well and the risk of entry of a hot ember also exists for foundation vents.
Accordingly, there exists today a need for a shape-memory spring activated soffit or foundation vent that helps to ameliorate the above-mentioned problems and difficulties as well as ameliorate those additional problems and difficulties as may be recited in the “OBJECTS AND SUMMARY OF THE INVENTION” or discussed elsewhere in the specification or which may otherwise exist or occur and are not specifically mentioned herein.
Clearly, such an apparatus would be a useful and desirable device.
2. Description of Prior Art
Vents, in general, are known. For example, the following patents describe various types of these devices, some of which may have relevance as well as others which may not have particular relevance to the invention. These patents are cited not as an admission of their having any particular relevance to the invention but rather to present a broad understanding of the current state of the art appertaining to either the field of the invention or possibly to other distal fields of invention.
U.S. Pat. No. 7,195,556 to Fichtelman, that issued on Mar. 27, 2007; U.S. Pat. No. 5,711,091 to Bos, that issued on Jan. 27, 1998; U.S. Pat. No. 5,393,221 to McNally, that issued on Feb. 28, 1995; U.S. Pat. No. 5,167,578 to Legault, that issued on Dec. 1, 1992; U.S. Pat. No. 4,848,653 to Van Becelaere, that issued on Jul. 18, 1989; U.S. Pat. No. 4,597,324 to Spilde, that issued on Jul. 1, 1986; U.S. Pat. No. 4,315,455 to Shaklee, that issued on Feb. 16, 1982; U.S. Pat. No. 4,123,001 to Kolt, that issued on Oct. 31, 1978; U.S. Pat. No. 3,232,205 to Bumstead, that issued on Feb. 1, 1966; U.S. Pat. No. 2,755,728 to Frisby, that issued on Jul. 24, 1956; and U.S. Pat. No. 2,718,187 to Frisby, that issued on Sep. 20, 1955 and including U.S. Patent Application Publication: U.S. Publication No. 2007/0200656 to Walak, that published on Aug. 30, 2007.
While the structural arrangements of the above described devices may, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a shape-memory spring activated soffit or foundation vent that will automatically close the vent if the ambient temperature rises to a predetermined first threshold amount.
It is also an important object of the invention to provide a shape-memory spring activated soffit or foundation vent that will retain the vent in a closed position if the ambient temperature exceeds a predetermined first threshold amount.
Another object of the invention is to provide a shape-memory spring activated soffit or foundation vent that will automatically open the vent when the ambient temperature falls below a second predetermined threshold amount.
Still another object of the invention is to provide a shape-memory spring activated soffit or foundation vent that automatically closes the vent when the temperature rises beyond a first threshold amount and which automatically opens the vent when the temperature falls below a second threshold amount.
Still yet another object of the invention is to provide a shape-memory spring activated soffit or foundation vent that can protect a home during a nearby fire by automatically closing a vent in response to an increase in ambient temperature, thereby helping to protect the house from fire by preventing the passage of burning embers through the vent and into an attic area.
Yet another important object of the invention is to provide a shape-memory spring activated soffit or foundation vent that can protect a home during a nearby fire by automatically closing a vent in response to an increase in ambient temperature, thereby helping to protect the house from fire by preventing the passage of burning embers through the vent and into a basement area.
Still yet another important object of the invention is to provide a shape-memory spring activated soffit or foundation vent that can protect a home during a nearby fire by automatically closing a vent in response to an increase in ambient temperature, thereby helping to protect the house from fire by preventing the passage of burning embers through the vent and into a crawlspace area.
A first continuing object of the invention is to provide a shape-memory spring activated soffit or foundation vent that automatically closes the vent when the temperature rises beyond a first threshold amount and which automatically opens the vent when the temperature falls below a second threshold amount and wherein the vent is reusable.
A second continuing object of the invention is to provide a shape-memory spring activated soffit or foundation vent that automatically closes the vent when the temperature rises beyond a first threshold amount and which automatically opens the vent when the temperature falls below a second threshold amount without damage to the vent, and wherein the vent will continue to provide the same or similar level of protection and utility for repeated uses, as may be needed over the course of time.
A third continuing object of the invention is to provide a shape-memory spring activated soffit or foundation vent that uses a shape-memory alloy type of spring to close the vent when a predetermined upper temperature threshold limit is exceeded.
A fourth continuing object of the invention is to provide a shape-memory spring activated soffit or foundation vent that uses a shape-memory alloy type of spring to close the vent when a first predetermined upper temperature threshold limit is exceeded and which uses a spring to open the vent when the temperature falls below a second predetermined lower temperature threshold limit.
A fifth continuing object of the invention is to provide a shape-memory spring activated soffit or foundation vent that uses a linear shape-memory alloy type of spring to close the vent when a predetermined upper temperature threshold limit is exceeded thereby providing a greater effective force for a given smaller thickness of spring and also providing a simple, cost-effective design for manufacture as well as having high-reliability and repeatability.
A sixth continuing object of the invention is to provide a shape-memory spring activated soffit or foundation vent that uses a Nitinol or a Flexinol wire type of a shape-memory alloy type of spring to close the vent when a predetermined upper temperature threshold limit is exceeded.
Briefly, a shape-memory spring activated soffit or foundation vent that is constructed in accordance with the principles of the present invention has a linear section of a shape-memory alloy type of spring that has a first expanded state with a longer length at low temperatures and a second contracted state with a shorter length at high temperatures. A counterforce type of spring urges a pivoting planar member within the vent into a normally open position when the shape-memory alloy type of spring is in the first expanded state. When the ambient temperature rises above a first temperature threshold amount the shape-memory alloy type of spring undergoes a sudden change of state and contracts from the first expanded state into the second contracted state. As the shape-memory alloy type of spring contracts it supplies a force that overcomes that of the counterforce type of spring and urges the pivoting planar member into a closed position, thereby preventing the passage of air or other objects through the vent. When the ambient temperature drops to below a second temperature threshold amount, the spring expands into the first expanded state. The counterforce type of spring then urges the pivoting planar member into the open position to again allow the passage of air through the vent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in perspective of an end portion of a shape-memory spring activated soffit or foundation vent.
FIG. 2 is a front view of the shape-memory spring activated soffit or foundation vent of FIG. 1 .
FIG. 3 is a front view of a louver of the shape-memory spring activated soffit or foundation vent of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 and on occasion also to FIG. 2 and FIG. 3 is shown, a shape-memory spring activated soffit or foundation vent, identified in general by the reference numeral 10 .
The shape-memory spring activated soffit or foundation vent 10 includes a one-quarter inch mesh 12 that faces an exterior of a structure (not shown) when the shape-memory spring activated soffit or foundation vent 10 is installed. The plane of the mesh 12 can be either horizontal or vertical, when the shape-memory spring activated soffit or foundation vent 10 is installed in a structure.
If the shape-memory spring activated soffit or foundation vent 10 is used as a soffit type of vent then it is typically installed under an eave (not shown) and the plane of the mesh 12 would be horizontal and generally in planar alignment with an underside surface of the eave. If the shape-memory spring activated soffit or foundation vent 10 is used as a foundation type of vent then it is typically installed through a concrete wall (not shown) and the plane of the mesh 12 would be vertical and generally in planar alignment with an exterior surface of the concrete.
While the shape-memory spring activated soffit or foundation vent 10 can include any preferred size, it preferably includes an overall height of 3.5 inches, a depth of 4.0 inches, and a length of 22.5 inches. These dimensions allow for easy placement between ceiling or roof joists (not shown) or between roof trusses (not shown) in eaves.
This size also allows for standard size openings to be provided through foundation (concrete) walls into which the shape-memory spring activated soffit or foundation vent 10 can be placed. If desired, the length can be shortened if sixteen inch spacing or some other spacing between joists or trusses is required.
The shape-memory spring activated soffit or foundation vent 10 is secured to the surrounding structure by any preferred fastener (not shown) that passes through fastening holes 14 provided in a mounting flange 16 . The mounting flange 16 extends around the face of the shape-memory spring activated soffit or foundation vent 10 and is parallel and typically adjacent to the plane of the one-quarter inch mesh 12 .
The mounting flange 16 is secured to a surrounding structure, identified in general by the reference numeral 18 . The mounting flange 16 extends outward beyond the surrounding structure 18 and prevents excessive insertion of the shape-memory spring activated soffit or foundation vent 10 into the opening that is provided to receive it.
The surrounding structure 18 is typically formed of sheet metal and provides a planar bottom panel 18 a , rear panel 18 b , top panel 18 c and two opposite side panels (not shown). The side panel of the shape-memory spring activated soffit or foundation vent 10 that is disposed nearest the viewer in FIG. 1 is not shown so as to provide improved clarity of view of the details of construction. Accordingly, the overall shape of the shape-memory spring activated soffit or foundation vent 10 is that of a rectangular solid with the mounting flange 16 extending outward and slightly beyond the rectangular solid shape of the surrounding structure 18 .
An axle 20 extends along the longitudinal length of the shape-memory spring activated soffit or foundation vent 10 and is parallel to the plane of the mesh 12 and also parallel with respect to the bottom 18 a , rear 18 b , and top 18 c side panels. The axle 20 is disposed generally close to the middle of the rear panel 18 b (i.e., halfway between the bottom panel 18 a and the top panel 18 c ) and is secured in place relative to the rear panel 18 b of the surrounding structure 18 by supporting members (not shown) that are attached on one end to the axle 20 and to the rear panel 18 b of the surrounding structure 18 at an opposite end thereof. The supporting members retain the axle 20 a predetermined distance away from the rear panel 18 b.
A pivoting member, identified in general by the reference numeral 22 , functions as a louver to regulate the passage of air through the shape-memory spring activated soffit or foundation vent 10 . The pivoting member 22 includes a pair of raised sides 24 that are disposed on opposite longitudinal ends of thereof. The raised sides 24 are generally perpendicular with respect to the overall plane of the pivoting member 22 .
The axle 20 passes through a pair of axle holes 26 (only one is shown) that are provided through each of the opposing raised sides 24 . Accordingly, the pivoting member 22 is able to pivot about the axle 20 in a first direction as shown by arrow 28 or in an opposite second direction as shown by arrow 30 .
The pivoting member 22 includes a center of gravity that extends along a longitudinal length of the pivoting member 22 . The axle holes 26 and therefore the axle 20 are preferably disposed as close as possible to the center of gravity of the pivoting member 22 . In this way only a minimal amount of force is required to urge the pivoting member 22 in either the first or second direction 28 , 30 . If the pivoting member 22 is generally symmetrical on each side of the axle 20 , then the axle 20 would preferably pass near a geometric center of the pivoting member 22 to dispose the axle 20 as close as possible to the center of gravity of the pivoting member 22 .
During normal use of the shape-memory spring activated soffit or foundation vent 10 , the pivoting member 22 will continue to pivot in the first direction as shown by arrow 28 until a rear lip 22 b of the pivoting member 22 is disposed against a rear stop 33 . The rear stop 33 is attached to the rear panel 18 b and protrudes therefrom an amount sufficient to make contact with the rear lip 22 b and thereby prevents further motion of the pivoting member 22 in the direction of arrow 28 .
The rear lip 22 b of the pivoting member 22 extends along an opposite side where a lip 22 a is disposed. The lip 22 a is disposed on a side of the pivoting member 22 (i.e., on a first side of the axle 20 ) that is closest to the mesh 12 and the rear lip 22 b is disposed on an opposite side of the pivoting member 22 with respect to the axle 20 .
The lip 22 a and the rear lip 22 b each provide a counter weight to help balance the pivoting member 22 and ensure that the center of gravity of the pivoting member 22 is disposed where the axle 20 is located.
The position of the pivoting member 22 as shown in FIG. 1 is the first, open position of the shape-memory spring activated soffit or foundation vent 10 and is the position that the shape-memory spring activated soffit or foundation vent 10 is normally disposed in when performing its normal function as a vent. In this position the plane of the pivoting member 22 (i.e., louver) is generally perpendicular with respect to the plane of the mesh 12 or of the rear panel 18 b.
Air is able to pass by the pivoting member 22 virtually unobstructed and to continue through the shape-memory spring activated soffit or foundation vent 10 . Ambient air normally begins to vent either an attic area or a foundation basement or crawl space area by entering the mesh 12 and exiting from locations to the rear of the shape-memory spring activated soffit or foundation vent 10 , as are described in greater detail hereinafter.
Preferably, the raised sides 24 (which are disposed along the distal ends of the pivoting member 22 ) are adjacent to the side panels of the surrounding structure 18 with only a minimal clearance amount therebetween. The space between the outside edge of the raised sides 24 and the distal ends (i.e., where the raised sides 24 are located) of the pivoting member 22 is too small to permit objects, such as embers or even smaller ember fragments, to pass. Accordingly, only a negligible amount of air is able to flow around the distal ends of the pivoting member 22 at all times.
When the shape-memory spring activated soffit or foundation vent 10 is disposed in the first or open position it permits the normal passage of air to occur there-through. In the first open position a lip 22 a of the pivoting member is disposed proximate the middle of the mesh 12 (inside the surrounding structure 18 ) and the lip 22 a extends across the length of the shape-memory spring activated soffit or foundation vent 10 , as shown in FIG. 1 . The means to urge the pivoting member 22 into the first or open position are discussed in greater detail hereinafter.
However, in the event of a nearby fire that raises ambient temperatures a sufficient amount the pivoting member 22 will be urged and will pivot in the opposite, second direction as shown by arrow 30 . The pivoting member 22 will continue to pivot in the direction of arrow 30 until the lip 22 a of the pivoting member 22 is disposed against an upper stop 34 . The upper stop 34 extends along the longitudinal length and is generally equal to the length of the lip 22 a.
At the same time that the lip 22 a makes contact with the upper stop 34 , the rear lip 22 b makes contact with a lower stop 32 .
When the lip 22 a is disposed against the upper stop 34 and the rear lip 22 b is disposed against the lower stop 32 , the shape-memory spring activated soffit or foundation vent 10 is disposed in the second or closed position and this position prevents the passage of any significant amount of air from occurring there-through.
The lower stop 32 and the upper stop 34 , when either is in contact with the lip 22 a , provide an effective seal that prevents the passage of any appreciable amount of air (or objects of any size) from occurring in the space that is disposed between the lip 22 a and the upper stop 34 and also in the space that is disposed between the rear lip 22 b and the lower stop 32 .
For the purpose of improving clarity of description, the pivoting member 22 , as shown in FIG. 1 is disposed in the middle of the mesh 12 in the first or open position. This position is a static or rest position in which the pivoting member 22 is almost always disposed unless an elevated ambient temperature condition exists, as is described in greater detail hereinafter.
The only other static or rest position possible for the pivoting member 22 is in the second, or closed position. Except for the briefest time duration (typically milliseconds) during which the pivoting member 22 will be transitioning either from the open position into the closed position or from the closed position into the open position, the pivoting member 22 will be disposed in one of the two static or rest positions, depending on which direction it is heading (either in the direction of arrow 28 until the pivoting member 22 is disposed in the open position or in the direction of arrow 30 until it is disposed in the closed position). In other words, any position between the first open position and the second closed position is not a static or rest position for the pivoting member 22 .
As previously mentioned, the normal (venting) position for the pivoting member 22 is in the open position with the rear lip 22 b in contact with the rear stop 33 and with the lip 22 a disposed near the middle of mesh 12 . This is the position that the shape-memory spring activated soffit or foundation vent 10 will almost always be in and which allows for the normal passage of air to occur.
When the pivoting member 22 is disposed in the first, open position a significant and appreciable amount of air is able to pass readily through the shape-memory spring activated soffit or foundation vent 10 and when it is disposed in the second, closed position the significant and appreciable amount of air is not able to pass through the shape-memory spring activated soffit or foundation vent 10 because its passage is obstructed by the positioning of the pivoting member 22 and by the seal provided by contact with the upper stop 34 and by contact with the lower stop 32 .
It is useful to note that while it is desirable to stop entirely the passage of air when the pivoting member 22 is disposed in the second, closed position it is still acceptable if a very small negligible amount of air to continues to flow through the shape-memory spring activated soffit or foundation vent 10 .
The amount of air that is deemed to be negligible can vary depending on industry standards and the application. The design of the shape-memory spring activated soffit or foundation vent 10 is varied to satisfy the required standards, for example, by design changes in the material that is used to form the upper and lower stops 34 , 32 . A more elastic material can provide a better seal. Similarly, the clearance between the ends of the pivoting member 22 and the side panels of the surrounding structure 18 can be varied or, if desired, material can be added to the side panels or to the ends of the pivoting member 22 to provide better seal capability.
When the pivoting member 22 is disposed in the second closed position with the lip 22 a adjacent to and in contact with the upper stop 34 and the rear lip 22 b also disposed against the lower stop 32 , it ensures that air cannot flow to the rear of the shape-memory spring activated soffit or foundation vent 10 to any location that is disposed beyond (i.e., behind) a plane that is defined by the lower stop 32 , the pivoting member 22 , and the upper stop 34 .
Conversely, when the pivoting member 22 is disposed in the first or open position air is able to easily flow to the rear of the shape-memory spring activated soffit or foundation vent 10 to any location that is disposed beyond (i.e., behind) the plane that is defined by the lower stop 32 , the pivoting member 22 , and the upper stop 34 .
Therefore, it is possible to locate one or more exit paths for air to exit from the shape-memory spring activated soffit or foundation vent 10 providing that they are disposed behind the plane that is defined by the lower stop 32 , the pivoting member 22 , and the upper stop 34 .
To illustrate flexibility in the location of possible air exit paths for the shape-memory spring activated soffit or foundation vent 10 a large first opening 36 is provided in the top panel 18 c between the upper stop 34 and the rear panel 18 b . Also, a large second opening 38 is provided in the rear panel 18 b . The second opening 38 in the rear panel 18 b can be larger than shown with a maximum opening size that is almost as large as the rear panel 18 b , if desired.
A first opening ember screen 36 a and a second opening ember screen 38 a are included and extend over the area that is provided by the first opening 36 and the second opening 38 , respectively. Only a portion of the first opening ember screen 36 a and the second opening ember screen 38 a are shown in the first and second openings 36 , 38 .
The first opening ember screen 36 a and the second opening ember screen 38 a are preferably made of stainless steel and include a preferred hole diameter of approximately 0.011 inches, which is small enough to prevent even small embers from passing through the shape-memory spring activated soffit or foundation vent 10 before a rise in temperature has occurred that is sufficient to cause activation of the shape-memory spring activated soffit or foundation vent 10 .
Otherwise, it is possible when during the approach of a fire, that small embers could be carried by convective air currents and that the embers might reach the shape-memory spring activated soffit or foundation vent 10 before a noticeable increase in ambient temperature occurred. It is important to ensure that such embers are blocked and not allowed to pass through the shape-memory spring activated soffit or foundation vent 10 . The first opening ember screen 36 a and the second opening ember screen 38 a prevent the passage of embers from occurring.
Activation of the shape-memory spring activated soffit or foundation vent 10 is discussed in greater detail hereinafter. The preferred hole diameter for the first opening ember screen 36 a and the second opening ember screen 38 a provides an effective barrier to embers while not excessively decrease airflow through the shape-memory spring activated soffit or foundation vent 10 .
An example of a possible material that can be used for either the first opening ember screen 36 a or the second opening ember screen 38 a is supplied by TWP of Berkeley and is classified in their product literature as, “Eight (8) Mesh Galvanized Hardware Cloth, 0.013 Wire Diameter, 36 Inches Wide Screen, 31 Gauge, ⅛ Mesh”.
In this manner, the shape-memory spring activated soffit or foundation vent 10 can provide venting at a right angle with respect to the plane of the mesh 12 or it can provide venting that is parallel to the plane of the mesh 12 and at an opposite end (i.e. to the rear) of the shape-memory spring activated soffit or foundation vent 10 as compared to where the mesh 12 is disposed. Right angle or upward venting may be desirable in certain types of installations whereas rear venting is desirable in many other types of installation. If desired, both the first opening 36 and the second opening 38 can be included or either the first opening 36 or the second opening 38 can be eliminated, depending on the intended use for any particular version of the shape-memory spring activated soffit or foundation vent 10 .
A shape-memory alloy spring 40 is provided that is attached to the top panel 18 c near the upper stop 34 at a first end 40 a of the shape-memory allow spring 40 . The shape-memory alloy spring 40 is preferably of linear construction, as shown, and it extends from the above described point of attachment in a generally downward and inward direction to a center of the lip 22 a of the pivoting member 22 to which it is secured in any preferred manner. The shape-memory alloy spring 40 , as shown, passes through an opening provided in a loop 42 . The loop 42 is attached at both ends thereof to an upper surface of the lip 22 a . In this way, any force that is applied to the loop 42 to urge it in the direction of arrow 30 will also urge the pivoting member 22 in that direction, as well.
The shape-memory alloy spring 40 continues past the loop 42 and in a direction that is generally outward and also upward toward an opposite end of the upper stop 34 , where an opposite end of the shape-memory alloy spring 40 is attached.
A counterforce spring 44 is also attached at a first end thereof proximate the upper stop 34 and, at an opposite end of the counterforce spring 44 , to a rear portion of the raised side 24 . If desired, a second identical counter force spring (not shown) is provided and is attached in like manner to the opposite side of the pivoting member 22 and to the opposite side of the upper stop 34 to provide either greater or a more balanced counterforce to the pivoting member 22 .
After the shape-memory spring activated soffit or foundation vent 10 has been installed in an eave (as a soffit vent) or in a foundation opening (as a foundation vent) for as long as the ambient temperature remains below a first predetermined upper temperature threshold limit the pivoting member 22 will be disposed in the first, open position and the passage of air will be permitted to occur normally through the shape-memory spring activated soffit or foundation vent 10 .
In this, the first or open position, the shape-memory alloy spring 40 is disposed in a first or extended state. Because this is the normal position for the pivoting member 22 it can also be regarded as a quiescent state for the shape-memory spring activated soffit or foundation vent 10 to be disposed.
Accordingly, when the pivoting member 22 is in the first or open position the shape-memory alloy spring 40 is in the extended state (i.e., its linear length is at a maximum amount) and it therefore does not supply any appreciable force to the pivoting member 22 . In the first or quiescent state, the counterforce spring 44 supplies a force that raises the portion of the pivoting member 22 that is disposed to the rear of the axle 20 in a generally upward direction and which urges the lip 22 a in a generally downward direction, thereby causing the pivoting member 22 to move in the direction of arrow 28 until the rear lip 22 b comes into contact with the rear stop 33 .
It is important to understand that as long as the shape-memory alloy spring 40 is in the extended state it will provide no force to oppose the force that is supplied to the pivoting member 22 by the counterforce spring 44 . Therefore, when the shape-memory alloy spring 40 is in the extended state, the pivoting member 22 will always be disposed as shown in FIG. 1 (in the first or open position) and air will able to vent through the device.
If a fire is nearby the ambient temperature will begin to rise in proportion to the intensity of the blaze and its approach to the structure. As the ambient temperature rises the shape-memory spring activated soffit or foundation vent 10 is also warmed accordingly. The normal venting of ambient air through the shape-memory spring activated soffit or foundation vent 10 quickly raises its temperature as well. Furthermore, because the shape-memory alloy spring 40 of the shape-memory spring activated soffit or foundation vent 10 is formed of metal it conducts heat especially well and will quickly rise in temperature in response to the ambient temperature rising.
When the ambient temperature rises above the first predetermined upper temperature threshold limit the shape-memory allow spring 40 is warmed by the passing air until it, too, has reached or exceeded the first predetermined upper temperature threshold. At this moment, the shape-memory alloy spring 40 will suddenly change its state from the first extended state and, according to the mechanical properties inherent in its design, it will quickly revert or spring back into a second contracted state. Unless a sufficient force prevents it from contracting fully into the second contracted state it will very quickly (typically within milliseconds) revert back into (or close to) the second contracted state. In the second contracted state the overall linear length of the shape-memory alloy spring 40 will decrease considerably from what it was when the shape-memory alloy spring 40 was in the extended state.
When in the contracted state, the shorter overall length of the shape-memory alloy spring 40 is not sufficient to permit the pivoting member 22 to remain in the first or open position. The shorter length of the shape-memory alloy spring 40 will supply a force to the loop 42 sufficient to overcome the force of the counterforce spring 44 and to urge both the loop 42 and the lip 22 a in the direction of arrow 30 until the lip 22 a is in contact with the upper stop 34 and the rear lip 22 b is in contact with the lower stop 32 . The shorter contracted length of the shape-memory alloy spring 40 is chosen to ensure that even when the pivoting member 22 is disposed in the second position at least some residual force greater than that supplied by the counterforce spring 44 will be provided by the shape-memory alloy spring 40 sufficient to retain the pivoting member 22 in the second or closed position. Because the shape-memory alloy spring 40 has only two states (extended or contracted) the transition of the pivoting member 22 from one state to another (open to closed or closed to open) will always occur quickly, requiring only milliseconds to complete for most versions of the shape-memory spring activated soffit or foundation vent 10 .
At this time the shape-memory spring activated soffit or foundation vent 10 will be closed and the venting of air will cease. Hot embers will be prevented from passing through the shape-memory spring activated soffit or foundation vent 10 .
The shape-memory alloy spring 40 , and therefore the shape-memory spring activated soffit or foundation vent 10 , will remain in the second, closed position until the ambient temperature falls below a second predetermined lower temperature threshold limit. The second predetermined lower temperature threshold limit includes a temperature that is lower than that of the first predetermined upper temperature threshold limit.
In other words, even after the ambient temperature has cooled to a level that is just below the temperature which caused the shape-memory spring activated soffit or foundation vent 10 to enter the second or closed state (i.e., below that of the first predetermined upper temperature threshold limit), it will not automatically revert back into the first or open state. It must cool an even greater amount in order to reach the second predetermined lower temperature threshold limit. At that time (i.e., as soon as the shape-memory alloy spring 40 has also been cooled to the second predetermined lower temperature threshold) the shape-memory alloy spring 40 will again suddenly revert back into its first or extended state.
It is a characteristic for shape-memory alloy springs, in general, to exhibit two distinct physical (mechanical) states where the transition from each state into the other state is temperature activated and in which a first state includes a more extended mechanical configuration and thereby the first state provides for a lower level of force (as a spring) and in which a second state includes a more contracted mechanical configuration and thereby the second state provides a higher level of force (as a spring).
Continuing with a general discussion about shape-memory alloy springs, the second contracted state is activated instantly whenever the temperature rises above the first predetermined upper temperature threshold limit, whereas the first extended state requires the temperature of the shape-memory alloy spring to fall below that of the first predetermined upper temperature threshold limit and to continue to descend even further until reaching the second predetermined lower temperature threshold limit, at which time activation of the shape-memory alloy spring will cause it to assume the first extended state. The shape-memory alloy spring 40 of the instant invention also functions in this way.
When the shape-memory alloy spring 40 has also been cooled to or below the second predetermined lower temperature threshold it will revert into the first extended state and being extended it will no longer exert a force upon the pivoting member 22 . The only force acting on the pivoting member 22 will be that as is supplied by the counterforce spring 44 which will quickly urge the pivoting member 22 to pivot about the axle 20 in the direction of arrow 28 and to enter into the first, open position. Typically, the pivoting member 22 will return from the second closed position into the first open position in a matter of milliseconds. Normal venting through the shape-memory spring activated soffit or foundation vent 10 will again resume.
The above closing and opening of the shape-memory spring activated soffit or foundation vent 10 can recur many times, if needed. While it is unlikely that many repeat cycles will occur, it is advantageous that the shape-memory spring activated soffit or foundation vent 10 be able to repeat its ability to automatically function in the manner previously described because this capability eliminates any need to remove the shape-memory spring activated soffit or foundation vent 10 after it has been triggered (i.e., after it has been closed) by a high temperature event and to replace it with a new device. This saves the cost of a new device as well as that of the labor to remove the old one and install a new shape-memory spring activated soffit or foundation vent 10 .
The difference in temperature between the first predetermined upper temperature threshold and the second predetermined lower temperature threshold is equal to that of the hysteresis of the shape-memory alloy spring 40 , and is a design variable, as is the preferred temperature for the first predetermined upper temperature threshold and for the second predetermined lower temperature threshold.
A preferred value for the first predetermined upper temperature threshold is 225 degrees Fahrenheit and a preferred value for the second predetermined lower temperature threshold is 125 degrees Fahrenheit. These temperatures can vary as desired, and are set into the shape-memory alloy spring 40 during its manufacture. Certain of the characteristics of the shape-memory alloy spring 40 are dependent upon the alloy that is used for its construction while other characteristics can be set during its manufacture. Shape-memory alloy springs generally undergo a type of conditioning during manufacture which sets their characteristics prior to usage, as is well known by those having skill in the art of designing and manufacturing shape-memory alloy types of springs 40 .
It is also possible to include a very low hysteresis value for the shape-memory alloy spring 40 . For some alloys the hysteresis value may be negligible or it can approach zero. If such a version of the shape-memory alloy spring 40 is used, for ambient temperatures in excess of the first predetermined upper temperature threshold the pivoting member 22 will be in the closed position while for ambient temperatures that are below the first predetermined upper temperature threshold the pivoting member 22 will be in the open position.
If the shape-memory alloy spring 40 includes a very low (or negligible) amount of hysteresis and if the shape-memory spring activated soffit or foundation vent 10 is exposed to a sustained ambient temperature that is approximately equal to the first predetermined upper temperature threshold, then the pivoting member 22 may be disposed in either the open or the closed position, or it may alternate between the two positions.
Generally, it is preferable to include at least some hysteresis for smoother operation and to ensure that the pivoting member 22 remains closed after activation until the ambient temperature has cooled a sufficient amount to prevent excessive heat from passing through the shape-memory spring activated soffit or foundation vent 10 , and possibly entering the structure. It is also important to note that any preferred value for the first predetermined upper temperature threshold or for the second predetermined lower temperature threshold are possible, and may vary in accordance with the design parameters and requirements for any given installation.
Accordingly, many variables of design are possible. For example, the shape-memory alloy spring 40 does not have to be linear. A coiled version (not shown) is also possible for use with modification to the design. However, the linear version provides for increased strength of pull (i.e., the force generated when it contracts) while using a thinner, less expensive material than may be available with the coiled version. Also, ease of assembly and therefore of manufacturing at low cost is also provided by the linear version along with a simplicity of design that contributes to long life, high reliability, and repeatability of functioning.
The invention has been shown, described, and illustrated in substantial detail with reference to the presently preferred embodiment. It will be understood by those skilled in this art that other and further changes and modifications may be made without departing from the spirit and scope of the invention which is defined by the claims appended hereto. | An apparatus for permitting venting through eaves and foundation walls at low temperature and which closes at high temperature includes a shape-memory alloy spring that has a first expanded state at the low temperature and a second contracted state at the high temperature. At high temperature the shape-memory alloy spring contract which, in turn, closes a pivoting louver thereby obstructing the passage of air. At low temperature, after overcoming hysteresis, the shape-memory alloy spring expands and a counterforce type of spring is then able to urge the louver back into the open position. This process can be repeated, if necessary, thereby eliminating the need for replacement of the apparatus after experience of the high temperature event has occurred. | 4 |
The invention concerns a transportable stand with elements which can be assembled from individual parts and be dismounted, which comprise a supporting structure and telescopic parts and cheeks which can be mounted thereon at different angles of inclination to the horizontal, which hold step elements for installation of mounting parts such as seats and rails.
BACKGROUND OF THE INVENTION
A stand construction of this type has been disclosed by a stand of the company Arena Seating.
In the conventional stand construction, cheeks are mounted to a supporting structure, which are either prolonged or shortened, through telescopic elements, at both ends depending on the inclination of the cheeks to the horizontal. The known cheeks can be used at different inclinations by providing mounting means for step elements on one cheek side and also on the cheek side diametral thereto with different separations from the respective cheek end.
To be able to offer an extended number of seats and more standing space at venues or in halls, transportable stands are known which consist of a plurality of individual parts and require a lot of time for assembly and/or disassembly. The individual stand parts are often large and heavy such that the stands, which are usually to be mounted without the assistance of a crane, are difficult to handle.
It is the underlying purpose of the invention to design stands which can be used according to the local requirements with easy assembly and/or disassembly and to reduce the number of or simplify the different elements required for assembly and/or disassembly.
SUMMARY OF THE INVENTION
This object is achieved in accordance with the invention in that the cheeks can be pivoted independently of the angle of inclination to the horizontal about a point of rotation which lies in the region of a first cheek end, and that each individual cheek has a first receiving point for the step elements which either coincides with the point of rotation or is disposed directly next to the point of rotation.
The stand construction comprising the inventive cheeks is advantageous in that step elements to be mounted to the cheeks always have a fixed predetermined first receiving point independent of the angle position of the cheeks to the horizontal where the first or last step element is mounted. Mounting of the inventive stand precludes or greatly reduces erroneous assembly of individual parts required for assembly since the screen for the step elements to be disposed on the cheeks always starts or terminates at the same first receiving point. An inventive cheek must be prolonged or shortened at only one end since the step elements used always terminate in the fixed first receiving point. The first receiving point for the step elements is also always the same, independent of the respective inclined position of a cheek. The first receiving point is not displaced in height and does not carry out a lateral motion when the angle positions of the cheeks vary. The bringing together of the point of rotation of a cheek in a different angle position and the first receiving point of a cheek for a step element further simplifies the overall construction. In total, the inventive construction reduces the number of elements required for assembling a stand and also reduces the number of different concrete designs of the elements.
In a further embodiment of the invention, the point of rotation has the same separation from the first end of the respective cheek irrespective of the length of a cheek. This is advantageous in that all inventive cheeks used in the stand construction are moved, i.e. pivoted, in the same fashion to obtain the predetermined end position of a cheek desired in the assembled state. If the points of rotation are equally fixed to each cheek, the overall stand structure is simplified.
In a further embodiment of the invention, the cheeks, telescopic parts, step parts and mounting parts can be joined to one another or joined to the supporting structure via secured plug and/or catch connections.
This is advantageous in that no loose individual parts are used for assembly of the stand and additional time-consuming screwing or wedging can be omitted. All connecting parts such as cheeks, step elements, telescopic parts, receiving heads, securing means, seat and/or rail connections can be coated with elastic surfaces and/or with elastic formations, profiles to connect the overall construction or individual connections of this construction in a sound-proof, in particular impact-sound-proof, sealed or play-free fashion. This measure eliminates noise which could be produced by individual elements under load.
In a further embodiment of the invention, the plug and/or catch connections are formed such that they are self-locking when connected which guarantees permanent secure assembly of the stand since security and safety checks are not required for a stand built with the inventive elements.
In a further embodiment, receiving heads are formed on the supporting structure of the inventive stand design, which receive the first end of a cheek and/or an end of the telescopic part.
This is advantageous in that no particular connecting elements are required between supporting structure and the cheeks to be mounted thereto. The receiving heads can securely and permanently hold the cheeks at the most different inclinations without additional screwing or bolting or wedging.
The receiving heads are formed to receive cheeks and telescopic parts which can be oriented at least at two different angles of inclination to the horizontal such that the same receiving heads can be used for any stand construction.
In a preferred embodiment of the invention, the receiving heads, holding a first end of a cheek, hold bolts which laterally project from the cheeks, wherein in the assembled state of the parts at least one bolt is overlapped by the respective receiving head and the bolts additionally project into a cavity which is limited by cheeks produced from a hollow section. One end of a telescopic part projects into this cavity and at least partially surrounds the bolts or rests on the bolts. The telescopic head of the telescopic part may be supported on the inner surface of a cheek for load relief and further means can be provided to connect and secure the connection to be created for forces acting in the horizontal direction.
This measure produces simple, permanent and safe connecting possibilities. The connections can be quickly formed and released with simple movements.
In a further development of the invention, recesses or mounting points are provided on an outer side of the cheek at defined separations into which profiled ends of the step elements engage or the profiled ends are mounted at the mounting points.
This is advantageous in that the step elements can be securely held on the cheeks via the most simple mounting means. Such cheeks can be produced at low cost and are easy to handle.
If the recesses are formed as openings of approximately twice the length of a width of a profiled end, laterally adjoining step elements can be introduced at one cheek. Only one opening is required at one cheek for both step elements. In a preferred embodiment, at least one of the profiled ends of a directly adjoining skeleton step or riser projects into the hollow section of the individual cheek and is immovably held on the cheek in a self-locking fashion or via fixing elements. This is advantageous in that the compelling sequence of the elements to be mounted, prevents having to work over gaps when the skeleton steps and risers are disposed on the cheeks.
The overall stand system is further facilitated if the step elements are formed from risers and skeleton steps, wherein the skeleton steps have the same step depth irrespective of the inclination of a cheek to the horizontal, and if openings are provided at the step edge bordering the risers for receiving the mounting elements. The same skeleton steps are used for any angle position of a cheek, and the step elements have openings for receiving seats or rail constructions. The seats or rails must be inserted into the openings provided for this purpose and are held in the openings in a self-locking fashion. The risers can also be simplified if they can be folded at some height and thus be adjusted to the most different angle positions of the cheeks in a simple way. The foldable section to extend a riser can be hinged to the skeleton step and/or the riser itself. For different angle positions of the cheeks, risers of different heights are provided. If e.g. cheeks of a length of 2.50 m are used for mounting a stand on a supporting structure with 50 cm height grid, and the step elements are mounted to the cheeks in accordance with the invention, skeleton steps of a step depth of 75 cm can be used for different angle positions of 0°, approximately 11° and approximately 22° and the risers have a height of 15 cm for an angle position of the cheeks of approximately 11° and, for an angle position of the cheeks of approximately 22°, a height of 30 cm.
If the smallest common multiple of step depth and a grid width of the supporting structure is larger than a grid width but smaller than approximately five times the grid width, all desired angles of inclination of a stand can be produced with one single embodiment of a cheek. In a preferred embodiment, with a uniform cheek length of 2.50 m, platforms are possible after every three grid widths. If cheeks of different lengths are combined, horizontally oriented platforms can be produced in shorter recurrent separations. To provide safe escape paths with the inventive stand construction, horizontally oriented cheek lengths of 75 cm are sufficient when they are connected to inclined cheeks of a length of 2.50 m. If the angle position of an inclined cheek is approximately 11°, the cheek must be prolonged to approximately 2.55 m through the telescopic part. If the angle position of a cheek is approximately 22°, the cheek is to be extended to approximately 2.69 m through a telescopic part. The predetermined lengths refer to a horizontally oriented cheek (0°) of 2.50 m and a height grid of 50 cm or 100 cm at the supporting structure.
Further advantages can be extracted from the description and the enclosed drawing. The features mentioned above and below can be used in accordance with the invention either individually or collectively in any arbitrary combination. The embodiments mentioned are not to be understood as exhaustive enumeration but rather have exemplary character for describing the invention. The step elements can be mounted on any type of cheeks. The described step elements must not necessarily be used with the described cheeks.
If rail posts are mounted to the step elements, these rail posts can be inserted into cavities of the skeleton steps and/or risers and further fixing and/or securing of the rail posts can be effected through engagement into the openings in the cheeks. The skeleton steps and risers can also be of one piece such that a step element is formed from one single element.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is shown in one embodiment in the drawing:
FIG. 1 shows an inventive cheek connection with receiving heads;
FIG. 2 shows the inventive cheek connection of FIG. 1 on an enlarged scale;
FIG. 3 shows a perspective view of inventive cheek elements with inventive step elements shown in sections;
FIG. 4 shows a connection between an inventive cheek and an inventive telescopic part with the possibility to mount and dismount an inventive step element;
FIG. 5 shows the connection of a telescopic part to a first cheek end;
FIG. 6 shows a side view of a further inventive embodiment of a cheek connection with two skeleton steps and one riser;
FIG. 7 shows a side view of FIG. 6 on an enlarged scale showing the connection of a telescopic part to a cheek;
FIG. 8 shows a perspective view of a skeleton step in accordance with FIGS. 6 and 7 adjoining a horizontally oriented cheek;
FIG. 9 shows a sectional representation of a skeleton step which is seated and secured on a horizontally oriented cheek;
FIG. 10 shows a rear view of a riser and skeleton step which seats on a horizontally oriented cheek.
DETAILED DESCRIPTION
In FIG. 1, reference numeral 10 illustrates elements of a stand which can be mounted and dismounted, comprising a first cheek 11 , a second cheek 12 and a third cheek 13 . The cheeks 11 , 12 , 13 are interconnected via a first telescopic part 14 and a second telescopic part 15 . The first cheek 11 , the second cheek 12 and the third cheek 13 are held at a first end 16 , 17 , 18 of the cheeks 11 , 12 , 13 via receiving heads 19 which are supported by a supporting structure, e.g. a scaffold structure. The supporting structure is a construction known from the state of the art which is therefore not shown in FIG. 1 .
In FIG. 1, the first cheek 11 is inclined to a first angle position 20 i.e. at an angle of inclination to the horizontal of e.g. approximately 22°. The second cheek 12 is shown in a second angle position 21 , e.g. 0° and the third cheek 13 is shown in a third angle position 22 , inclined to the horizontal by approximately 11°.
The cheeks 11 , 12 , 13 serve for mounting step elements which generally consist of skeleton steps and risers. Mounting parts such a seats and rails can be mounted to the step elements which are not shown in the figure.
The cheeks 11 , 12 , 13 of the inventive stand construction can be pivoted about points of rotation 23 , 24 , 25 which are in the region of the first ends 16 , 17 , 18 . In the region of the first ends 16 , 17 , 18 , holding means are provided on the cheeks 11 , 12 , 13 which are received by the receiving heads 19 . The cheeks 11 , 12 , 13 are formed of a hollow section. The ends of the cheeks 11 , 12 , 13 , opposite to the first ends 16 , 17 , 18 , are provided with telescopic parts 14 , 15 for connection to a further cheek and for interconnecting the adjoining cheeks 11 , 12 , 13 . The telescopic parts 14 , 15 can be drawn out of the respective cheek ends to different lengths and be fixed in any position to keep a grid width predetermined by the supporting structure or the horizontally oriented cheek length in dependence on a predetermined angle of inclination to the horizontal. If step elements are disposed on the cheeks 11 , 12 , 13 , these step elements are disposed irrespective of the angle of inclination to the horizontal of a cheek 11 , 12 , 13 always such that the first or last step element is mounted in a first receiving point 26 (depending on the direction of assembly) which coincides with the point of rotation 23 or is formed directly next to the point of rotation 23 .
FIG. 1 shows two cheek lengths. The length of the first cheek 11 corresponds to the length of the third cheek 13 , the second cheek 12 for the second angle position 21 of 0° is shorter than the first cheek 11 and the third cheek 13 . The angle position 20 is approximately 22° and the angle position 22 is approximately 11°.
FIG. 2 shows, compared to FIG. 1, an enlarged view of the cheeks 11 , 12 , 13 . The cheeks 11 , 13 are displayed shortened for a better overview. The cheeks 11 , 12 , 13 are interconnected via the first telescopic part 14 and the second telescopic part 15 . The receiving heads 19 hold the cheeks 11 , 12 , 13 at the first end 16 , 17 , 18 in that bolts 27 , 28 , 29 formed on the cheeks 11 , 12 , 13 engage in recesses of the receiving heads 19 . The bolts 27 , 28 , 29 are disposed on a circular arc whose center is in the point of rotation 23 , 24 , 25 . The radius from the point of rotation 23 , 24 , 25 to the circular arc with the bolts 27 , 28 , 29 is always the same in the inventive cheeks 11 , 12 , 13 . The position of the bolts 27 , 28 , 29 on the circular arc may differ depending on the desired inclination of the cheeks 11 , 12 , 13 within an overall stand construction. The recesses, formed on the receiving heads 19 , for the bolts 27 , 28 , 29 are selected such that they can receive the bolts 27 , 28 , 29 in different angle positions of the cheeks 11 , 12 , 13 and are designed such that at least one bolt 27 , 28 , 29 is overlapped by a hook-shaped end 30 of a receiving head 19 . The hook-shaped ends 30 of the receiving heads 19 secure the connection between the receiving head 19 and a cheek 11 , 12 , 13 from inadvertent release of the connection between receiving head 19 and the cheek 11 , 12 , 13 .
FIG. 3 shows a partial spatial section of an inventive stand construction with step elements 31 which are composed of skeleton steps 32 and risers 33 . The step elements 31 can be detachably mounted to the cheeks 11 , 12 , 13 in that profiled ends of the step elements 31 engage in openings 34 of the cheeks 11 , 12 , 13 which are formed on a cheek side 35 , 36 , 37 . The openings 34 formed on the cheek side 35 , 36 , 37 are separated from each other such that skeleton steps 32 with the same step depth can be mounted in or on the openings 34 independent of the angle position of the individual cheeks 11 , 12 , 13 , and a first step element is always mounted in the first receiving point. The telescopic parts 14 , 15 comprise a mandrel 38 which can also engage in the openings 34 and which can determine the length of the telescopic part 14 , 15 to be selected. A telescopic head 39 of the first telescopic part 14 is partially visible in FIG. 3 . The telescopic head 39 connects the first cheek 11 to the second cheek 12 . The supporting structure which is not shown in FIG. 3 holds the cheeks 11 , 12 , and 13 via the receiving heads 19 .
In the transition region between a skeleton step 32 and a riser 33 , a series of openings 40 are provided which can receive mounting elements such as seats and rails.
FIG. 4 shows the transition region between a first cheek 11 and a second cheek 12 , partially in sectional view such that the profiled ends 41 , 42 of the skeleton steps and risers 32 , 33 are visible and also the securing lock 43 of the first telescopic part 14 . The profiled end 41 of the skeleton step 32 engages through one of the openings 34 and engages behind the first cheek 11 with the free end. The profiled end 42 of the riser 33 also engages in the opening 34 and is designed such that in cooperation with the profiled end 41 , it blocks or prevents vertical displacement of skeleton step and riser 32 , 33 . The numerous openings 34 formed in the first cheek 11 are provided for the step elements 31 when the cheeks 11 , 12 are mounted in different angle positions. With the mandrel 38 , the first telescopic part 14 engages through an opening 34 and is supported at one end via the telescopic head 39 on the second cheek 12 . The telescopic head 39 comprises additionally the securing lock 43 which secures connection between the first telescopic part 14 and the second cheek 12 . The first telescopic part 14 is supported on the other end via a supporting plate 44 on the inner surface of the first cheek 11 .
The bolts 27 , 28 , 29 serve as holding means for the receiving head 19 as well as for the telescopic head 39 . The bolts 27 , 28 , 29 project past the cheek outside and into the hollow section of the cheek 12 such that the telescopic head 39 can at least partially surround the bolts 27 , 28 , 29 . FIG. 4 shows the securing lock 43 in a position in which the first telescopic part 14 is undetachably connected to the second cheek 12 .
If a supporting structure with mounted cheeks 11 , 12 is erected and the cheeks 11 , 12 have mounting points like the openings 34 shown in FIG. 4, the skeleton steps and risers 32 , 33 can be mounted to the cheeks 11 , 12 such that no auxiliary construction or additional means is required. The skeleton step 32 is disposed on the second cheek 12 in the direction of the arrow 45 by pivoting the skeleton step 32 such that the profiled end 41 engages in the opening 34 and engages behind this opening 34 . If the skeleton step 32 is positioned, the riser 33 can be inserted into the opening 34 by pivoting it in the direction of the arrow 46 . If the riser 33 is vertically oriented and the profiled ends 41 , 42 engage in the opening 34 as shown in the figure and the skeleton step 32 is hooked with the riser 33 through the mutual engagement, the skeleton step 32 and the riser 33 are rigidly and undetachably connected to the second cheek 12 . If the riser 33 shall be released from the second cheek 12 , the riser 33 must be pivoted against the direction of arrow 46 that far that the profiled end 42 can be removed from the opening 34 . If the riser 33 has been removed from the opening 34 , the skeleton step 32 can be released through motion of the skeleton step 32 against the direction of arrow 45 from the second cheek 12 .
If a further skeleton step 32 shall be disposed on a vertically oriented riser 33 , this skeleton step 32 is to be disposed on the riser 33 through a pivoting motion in the direction of arrow 47 . When the skeleton step is disposed on the riser 33 , nubs and noses engage behind the end of the riser 33 such that the skeleton step 32 is undetachably connected to the riser 33 . The skeleton step 32 can be released from the riser 33 only via a motion against the direction of arrow 47 . The mounting and dismounting of the skeleton step and risers 32 and 33 described for a step element 31 can be transferred arbitrarily to a step element adjoining a step element 31 such that the described assembly and disassembly of skeleton step and risers 32 , 33 can produce stand constructions of any height and length.
FIG. 5 shows a cross-sectional view of the first cheek 11 and second cheek 12 to show the connection of the telescopic head 39 to the second cheek 12 . The securing lock 43 is kept in the telescopic head 39 such that it can be lifted and displaced in the direction of arrow 49 . In the position shown in the figure, the telescopic head 39 overlaps the bolts 27 and 28 with recesses formed on the telescopic head 39 and the securing lock 43 is shown in an end position in which the first telescopic part 14 is undetachably connected to the second cheek 12 . If the securing lock 43 is displaced into the other end position in the elongate hole 48 , the connection between the second cheek 12 and the first telescopic part 14 can be released. The skeleton step 32 and the riser 33 are inserted in the second cheek 12 in a self-locking fashion and a projection 50 is formed on the riser 33 which can house the openings 40 shown in FIG. 3 .
If the skeleton step 32 is connected to the riser 33 , a ball formed on the riser 33 is disposed in a socket of a ball and socket joint, which is formed in the edge region of the skeleton step 32 . Both the ball-shaped and the socket-shaped formation can extend across the entire length of a skeleton step and/or riser 32 , 33 . A projection formed on the socket engages behind or into a recess on the ball of the riser 33 to produce an undetachable connection between skeleton step and riser 32 , 33 . If the connection between the skeleton step and riser 32 , 33 in the lower region, i.e. in the region of the cheek shall be released, the ball must at first be turned out or displaced out of the overlapping or locking engagement in the socket until both parts can be separated.
FIG. 6 shows a further embodiment of inventive elements of a stand which can be mounted and dismounted. The first cheek 11 is connected to a second cheek 12 via the telescopic part 14 . A skeleton step 62 which is detachably connected to a riser 63 is disposed on the cheek 12 which is held in its horizontally oriented position by a receiving head 19 . A further skeleton step 62 is held at the upper end of the riser 63 , and the other end of the further skeleton step 62 flatly rests on the inclined cheek 11 . Another riser 63 joins this end which has the same connection to the skeleton step 62 as shown in the right part of FIG. 6 .
The cheek 12 has an opening 64 via which a pin 65 of an end profile of the skeleton step 62 engages. The end profile of the skeleton step 62 has a catch 66 which engages behind an edge projection of the cheek 12 and undetachably connects the skeleton step 62 to the cheek 12 . A receiving pocket 67 is formed on the end profile of the skeleton step 62 opposite to the pin 65 into which the lower end profile of the riser 63 engages in a detachable fashion. The upper end of the riser 63 is provided with a further end profile with a recess 68 which holds a free end of the skeleton step 62 which is not supported on a cheek 11 , 12 .
If a step element is to be disposed on an inventive cheek connection, at first the skeleton step 62 is disposed on the horizontally oriented cheek 12 in that the pin 65 is inserted into the opening 64 . With this inserting motion, one end of the catch 66 engages automatically in a free edge of the cheek 12 . If a riser 63 is to be inserted into the receiving pocket 67 of the skeleton step 62 , the riser 63 is disposed at an angle on the end of the skeleton step 62 in that the erected skeleton step 62 subtends an angle <90° with the riser 63 . Subsequently, the riser 63 is pushed past the skeleton step 62 that far that the riser 63 falls into the receiving pocket 67 . In the still present inclined position of the riser 63 , the riser 63 is lifted and simultaneously vertically oriented in the direction of arrow 69 in an anticlockwise direction. Subsequently, the riser 63 is lowered and is held in the receiving pocket 67 in a position shown in FIG. 6 . If a further skeleton step 62 is to be connected to the riser 63 at the upper end of the riser 63 , a skeleton step 62 is vertically oriented and inserted into the recess 68 and subsequently lowered in an anticlockwise direction in the direction of arrow 70 that far until the other free end of the skeleton step 62 with the pin 65 engages into the opening 64 of the inclined cheek 11 . The end profile of the skeleton step 62 is formed such that it can flatly abut on an inclined cheek 11 .
If a riser 63 is inserted into the receiving pocket 67 and vertically aligned it blocks the pivoting region of the catch 66 and holds the catch 66 such that a free end of the catch 66 always engages behind a free edge section of the cheek 11 , 12 . In the arrangement shown in FIG. 6, the skeleton steps 62 cannot be lifted from the cheeks 11 , 12 .
If a step element is to be lifted from a cheek connection shown in FIG. 6, the riser 63 must firstly be lifted in the receiving pocket 67 until it can be turned out of the receiving pocket 67 in a clockwise direction. If the connection between the skeleton step 62 and the riser 63 is interrupted in that the receiving pocket 67 is free, the catch 66 is also pivotable and the skeleton step 62 can be lifted from the cheek 11 , 12 . When lifting the skeleton step 62 , the catch 66 automatically opens i.e. it releases the engagement on the cheek 11 , 12 .
FIG. 7 shows the cheek connection of the cheeks 11 and 12 with a cut cheek 12 , how the two cheeks 11 and 12 are interconnected via the telescopic part 14 . The skeleton step 62 is disposed on the cheek 12 in that the pin 65 engages in the opening 64 of the cheek 12 . The end profile of the skeleton step 62 is undetachably held together with the cheek 12 via the catch 66 . An end of the riser 63 is inserted into the receiving pocket 67 of the end profile of the skeleton step 62 . The riser 63 is vertically oriented and the receiving pocket 67 is formed such that it comprises a free space when a riser 63 is inserted into the receiving pocket 67 . The free space permits that the vertically aligned riser 63 can be lifted in the receiving pocket 67 . If the riser 63 is lifted, it engages behind a hook-shaped formation on the end profile of the skeleton step 62 , and in the lifted state of the riser 63 it is possible to pivot the riser 63 in a clockwise direction such that it can be removed from the receiving pocket 67 . When the riser 63 is vertically oriented and inserted in the receiving pocket 67 , the catch 66 cannot be moved and connects the skeleton step 62 with the cheek 12 or cheek 11 in an undetachable fashion.
FIG. 8 shows a perspective view of a shortened and horizontally oriented cheek 12 onto which a skeleton step 62 is disposed. FIG. 8 does not show the entire width of the skeleton step 62 . A skeleton step 62 basically has in each free end region two opposing support points with pins 65 which engage in openings 64 of a cheek 12 in each case. FIG. 8 shows only one cheek 12 . The skeleton step 62 engages via the pin 65 into the opening 64 , and when the skeleton step 62 is disposed on the cheek 12 , an end of the catch 66 engages behind a free edge section of the cheek 12 . The catch 66 is fastened on the skeleton step 62 such that it can be pivoted about an axis 71 . The receiving pockets 67 are indicated in the figure into which ends of risers 63 can engage. If the skeleton step 62 is lifted from the cheek 12 , the catch 66 automatically pivots in that it releases the engagement on the cheek 12 . The skeleton step 62 can always be lifted from the cheek 12 when the receiving pocket 67 is not occupied by a riser 63 .
FIG. 9 shows a sectional representation of a skeleton step 62 disposed on a cheek 12 . The pin 65 of the skeleton step 62 engages in the opening 64 of the cheek 12 and the catch 66 engages behind a free edge section of the cheek 12 by correspondingly turning about the axis 71 .
FIG. 10 shows a rear view of a skeleton step 62 and a riser 63 disposed on the one cheek 12 on a side. The catch 66 engages behind a free edge section of the cheek 12 , and in the arrangement shown, the skeleton step 62 cannot be lifted from the cheek 12 .
In a stand with elements which can be mounted and dismounted from individual parts, and which comprise a supporting structure and telescopic parts 14 , 15 which can be mounted thereon at different inclinations to the horizontal, and cheeks 11 , 12 , 13 which hold step elements for mounting mounting parts such as seats and rails, the cheeks 11 , 12 , 13 can be pivoted independently of the inclination to the horizontal about a point of rotation 23 , 24 , 25 which is located in the region of a first end 16 , 17 , 18 of a cheek 11 , 12 , 13 . Each individual cheek 11 , 12 , 13 has a first receiving point for step elements and the point of rotation 23 , 24 , 25 of a cheek 11 , 12 , 13 either coincides with the first receiving point 26 for the step elements or it is directly neighboring to the point of rotation 23 , 24 , 25 . | The invention relates to a stage, comprising elements, which may be assembled and disassembled from individual pieces, as part of a sub-structure with telescopic pieces ( 14, 15 ) and bars ( 11, 12, 13 ) fixed thereto, at various angles to the horizontal, to which may be fixed stepped elements for the attachment of superstructure pieces such a seats and railings. Said bars ( 11, 12, 13 ), may be pivoted about a pivot point ( 23, 24, 25 ), in the region of a first end ( 16, 17, 18 ) of a bar ( 11, 12, 13 ), in a manner independent of the angle to the horizontal. Each individual bar ( 11, 12, 13 ) comprises a first attachment point for stepped elements and the pivot point ( 23, 24, 25 ) of a bar ( 11, 12, 13 ) is either congruent with the first attachment point ( 26 ) or it is immediately adjacent to the pivot point ( 23, 24, 25 ). | 4 |
FIELD OF THE INVENTION
[0001] The field of the invention relates to systems and methods for securing networked computing devices, and more particularly to systems and methods for testing and managing defensive network devices.
BACKGROUND OF THE INVENTION
[0002] Placing a computing device on a public computer network, such as the Internet, subjects the computing device to considerable risk of unauthorized access and misuse by other entities. This is particularly true for server systems (such as websites on the Internet) that receive large amounts of data traffic, many of which come from unknown or anonymous sources. One approach known in the art to minimize this risk is the utilization of defensive network devices 300 (“DNDs”), shown in FIG. 1 . These devices 300 are located such that they can inspect the data traffic going to and from a particular networked 200 computing device 100 for bad data traffic, e.g., data traffic that includes viruses or malware that may cause undesirable behavior to the networked computing device 100 and/or other devices that the networked computing device is operatively coupled to.
[0003] Traditional examples of DNDs known in the art include intrusion detection systems (“IDSs”), intrusion prevention systems (“IPS”) and web application firewalls (“WAFs”). These devices generally monitor data traffic on a network 200 going to and from a networked computing device 100 for bad traffic to alert personnel of detected bad traffic (“detection mode”) and/or automatically intercept and block such traffic (“prevention mode”).
[0004] The effectiveness of DNDs is generally dictated by their accuracy and precision, e.g., the ability to accurately and precisely discern bad traffic from good. Inaccurate DNDs can significantly impact businesses. For instance, failing to detect bad traffic may allow malware to enter into and infect a networked computing device 100 or it may allow an attack against the networked computing device 100 that will allow a hacker to take control of that device 100 or steal confidential data form that device 100 . Further, genuinely good traffic inaccurately identified as bad may be blocked from the networked computing device 100 , e.g., a genuine business transaction with a commercial website. Vendors of DNDs 300 can provide users with a large number of new rules on a regular basis, and it is very difficult for users of DNDs 300 to determine if these new rules will cause false positives in their network. False positives can have a high business cost because they can impair network traffic that a) is essential to the operation of the business and/or b) generates revenue. This may cause personnel to use DNDs in detection mode rather than prevention mode, thereby causing human intervention, which can slow response time and potentially overwhelm human resources.
[0005] This issue may be particularly prevalent in web applications. Because web applications are generally structured differently from one another and because they have different page and parameter names, traffic having undesirable attacks can be different from web application to web application. As such, a single solution attempt to apply to all web applications may likely cause accuracy issues and pose a significant risk of blocking good traffic. This risk can be dealt with by retesting a web application manually with good traffic but this is time consuming, especially given the large number of potential inputs in even a medium-sized web application. For example, studies have shown that with the current state of the art, it may take months for administrators and developers to test, detect and remedy vulnerabilities in a web application.
[0006] Accordingly, improved systems and methods for monitoring and managing defensive network devices are desirable.
SUMMARY OF THE INVENTION
[0007] The field of the invention relates to systems and methods for securing networked computing devices, and more particularly to systems and methods for testing and managing defensive network systems
[0008] In a preferred embodiment, a defensive network management subsystem is included. The subsystem is operatively coupled to a defensive network system and a networked computing system. The defensive network management subsystem is configured to generate test data for the networked computing system, transmit the generated test data to the networked computing system, and record the networked computing system's response to the generated test data. The subsystem is further configured to correlate its recorded data with the defensive network system's response to said generated test data to assess the defensive network system's efficacy.
[0009] Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In order to better appreciate how the above-recited and other advantages and objects of the inventions are obtained, a more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments thereof, which are illustrated in the accompanying drawings. It should be noted that the components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views. However, like parts do not always have like reference numerals. Moreover, all illustrations are intended to convey concepts, where relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely.
[0011] FIG. 1 is an exemplary diagram of a prior art networked computing system having a defensive network device;
[0012] FIG. 2 is an exemplary diagram of a system in accordance with a preferred embodiment of the present invention;
[0013] FIG. 3 is an exemplary diagram of a process in accordance with a preferred embodiment of the present invention.
[0014] FIG. 4 is an exemplary diagram of another system in accordance with a preferred embodiment of the present invention;
[0015] FIG. 5 is an exemplary set of network data generated by a system in accordance with a preferred embodiment of the present invention.
[0016] FIG. 6 is an exemplary report generated by a system in accordance with a preferred embodiment of the present invention.
[0017] FIG. 7 is an exemplary rule generated by a system in accordance with a preferred embodiment of the present invention.
[0018] FIG. 8 is an exemplary rule generated by a system in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Turning to FIG. 2 , a system is shown in accordance with a preferred embodiment of the present invention. In addition to a DND 300 known in the art, to address the issues described above, a DND management device 1000 is provided. The DND management device 1000 includes a processor, memory, a user interface, and a network component (not shown) operatively coupled to the DND 300 and the networked computing device 100 . This coupling can be achieved by computer network 200 , a separate network, and/or a direct connection. In the alternative, the DND management device 1000 can also be implemented as a software-based system included in the same physical device as the DND 300 or the networked computing device 100 . The management device 1000 can also be operated on a separate server, remote to the DND 300 and the networked 200 computing device 100 in the form of a third party service, also known in the art as software as a service (“SaaS”).
[0020] Generally, the DND manager 1000 is configured to test and manage the DND 300 to ensure that the DND 300 is detecting bad traffic associated with the networked computing device 100 at a desirable level of accuracy, thereby facilitating a desirable level of operation by the networked computing device 100 .
[0021] Turning to FIG. 3 , a test and management process 2000 performed by the DND manager 1000 in accordance with a preferred embodiment of the present invention is shown. A test environment is first created with sample DND test data having both good and bad data traffic (Action Block 2100 ). This test environment can be generated in a number of ways by themselves or in combination. Below are some examples that can be used by themselves or in combination in accordance with a preferred embodiment:
[0022] 1) The test data can be created manually by personnel. Packets can be created by hand or by creating network requests that are captured using a software program such as a proxy device (not shown) located between the DND 300 and the network computing device 100 .
[0023] 2) Turning to FIG. 4 , an automated scanning tool 400 known in the art can be used to scan the computing device 100 to identify relevant weakness on the device through the use of pre-existing testing methods. In the case of web-based applications, a web application scanner such as NT OBJECTives NTOSpider can be used to create these requests (information of which can be found at http://www.ntobjective.com/security-software/ntospider-application-security-scanner/). A web application scanner 400 is generally configured to identify page(s) in a website and create a list of pages and parameters. For instance, scanning tool 400 can identify variable names and types, such as standard GET & POST parameters, or data inside JavaScript Object Notation (“JSON”), Representational State Transfer (“REST”), Action Message Format
[0024] (“AMF”), and Simple Object Access Protocol (“SOAP”) data formats. The page and parameter name combinations (with types) can be used to create the test data (Action Block 2100 ). This can be achieved by either recording actual packets or by placing the page data in a database and reconstructing the packets. For example, if there is a last name parameter on the home page of a site, the test data could include tests for O'Neil, Johnson and de Villas. These requests may be normal traffic that contains elements that can also be used in attacks (e.g. the words or, like, and, and delete which are used in many attacks or which is used in the name O'Neil, for example). This list can be expanded by extrapolating and creating additional requests to cover any potential gaps by the scanner. Such requests may include characters and strings to create a working attack payload and may incorporate known techniques for attacking websites, e.g., a SQL Injection attack.
[0025] To illustrate, a website (e.g., networked computing device 100 ) may sell a product, such as a handbag. On the page, the handbag may be associated with an ID number, e.g, 5. In normal operation, if a user selects the handbag, a request would be sent to the server 100 that would look as follows: http//www.site.com/viewproduct.php?id=5. The website would then forward the request to a backend database server to retrieve data associated with the product (not shown). To attack such a site, an example sequence of requests may look as follows:
A) http://www.site.com/viewproduct.php?id=5 B) http://www. site. com/viewproduct.php?id=7-2
If the website's response to requests A) & B) match, it is likely that the backend database server to the website performed the calculation of 7-2 into 5 and then used that resulting number in its database lookup. An application with proper input escaping or a DND 300 with a proper rule or filter would not allow such a result. For example, the rule in the DND 300 would include blocking the use of the minus sign. A scanning tool 400 would be used to create data, such as the second request, that would facilitate detecting whether such a rule exists within the DND 300 .
[0028] In yet another example, DNDs 300 known in the art will typically detect and block a known SQL Injection attack known as ‘or 1=1’. The request may look like the following: http:/www.webscantest.com/login.php?user=admin' or 1=1&password=Password1. Typical DNDs 300 would include rules to block such known attacks. However, more sophisticated attacks may use variations not detectable by these typical rules. For instance, an attack may change (admin' OR 1=1) to (admin' OR MOD(8,7) IN (1)), where MOD (8,7) is a math operation remainder and IN(1) is asking if 1 is in a list where the only value in the list is 1 . The end result is effectively the same ‘or 1=1’ SQL Injection attack but may be undetectable with existing DNDs 300 . The scanning tool 400 may be used to create and test these variations to identify whether a DND 300 has a rule or filter to block such attacks.
[0029] 3) A device, such as a sniffer known in the art, can be placed in front of the networked computing device 100 and record normal network traffic to create the test data (Action Block 2100 ). Further, this device can be placed in front an entire network or any subset thereof by specifying a subnet, IP range, or individual devices. This normal network traffic could be used to configure the DND 300 to assess whether the rules are too broad, thereby undesirably blocking good traffic. For example, one rule may block the unexpected use of However, there may be situations where the use of ' is proper. For instance: http://www.webscantest.com/datastore/search_get_by_lastname.php?name=O'Brian. Normal network traffic with data such as this may facilitate in determining whether the DND 300 improperly blocks an otherwise proper request (i.e., good data). For example, for phone numbers, numbers plus ( )-.[space] must be allowed, and for email addresses, alphanumeric plus @.-_must be allowed. A DND 300 configured after being tested with such data from an intranet or subnet may provide the administrator a high degree of confidence that the particular intranet is free of malicious traffic and could use all the traffic from that subnet.
[0030] 4) Vendors and/or IT professionals can supply test data for specific networked computing device 100 . For example, a payroll web application vendor could supply good test data to be used to test their software.
[0031] 5) Vendors can supply log files from their defensive network devices 300 that are a) on network segments assumed to have only good data or b) scrubbed of malicious requests by their device to generate good test data.
[0032] 6) Protocol specific templates can be used to aid in the creation of requests with support for replaceable values. For example, in the case of a POP3 email checking protocol, the data exchange may look as follows:
SEND: USER [email|username] SEND: PASS [password] RECV: OK+ SEND: STAT RECV: OK+ SEND: LIST RECV: 1 1205 RECV: 2 1206 SEND: RETR [int] SEND: TOP [int] SEND: QUIT
With this template, DND test data can be generated from modifying certain aspects of this protocol with possible attack data.
[0044] After the test data and environment has been established (Action block 2100 ), the test data is provided to the DND manager 1000 , which then applies the test data to the networked computing device 100 (Action Block 2200 ). It will create test packets and/or requests from the test data and transmit them over the network 200 to the networked computing device 100 and the DND 300 . The DND manager 1000 will then record the networked computing device's 100 responses (Action Block 2300 ). The DND manager 1000 can also access the DND's 300 logs that will record its responses to the test data sent to the networked computing device 100 . Preferably, the DND 300 is configured to be in detection mode so that the DND 300 will identify the traffic it determines is bad based on its current configuration. The DND manager 1000 can then correlate the networked computing device's 100 response with the data in the DND's 300 log to determine which packets/requests are deemed bad by the DND 300 and assess what blocked data will look like (Action Block 2300 ). Turning to FIG. 5 , an example result of a correlation is shown, illustrating where the ‘or 1=1’ SQL Injection attack 3000 is detected by the DND manager 1000 and/or DND 300 .
[0045] From the correlation at Action Block 2300 , the DND manager 1000 can facilitate the detection of potential vulnerabilities with the DND 300 (Action Block 2400 ). For example, the DND manager 1000 can determine whether the DND 300 is failing to capture certain bad traffic by testing the DND 300 with a series of traffic requests that are known to be malicious and measuring the responses of the DND 300 . In another example, the DND manager 1000 can have an interface that allows users to specify the bad traffic response of the DND 300 . In yet another example, the DND manager 1000 can be configured with known bad traffic responses of DNDs 300 that it can check to see if a response indicates bad traffic. Further, the DND manager 1000 can determine the DND 300 used based on a response to bad traffic or by allowing the user to select the DND 300 in use.
[0046] The DND manager 1000 can then generate a report that presents the results of the correlation to an administrator (Action Block 2500 ). An example report is shown in FIG. 6 . The report may include the following information:
[0047] 1) A summary grouped by packet/request type with number of requests assumed to be good traffic and the number that were blocked. For web applications, for example, this can include requests grouped by page and/or parameter type.
[0048] 2) The response to each request.
[0049] 3) In the case where the test data was generated from normal traffic, e.g., with a web scanning application 400 , there may be an increased possibility that some of the requests will be bad traffic, such as attacks. In this case, false positives should not be reported and if there are a large number of these, weeding out these results will be time consuming. The following methods can be implemented to deal with this problem:
[0050] a. Certain IP addresses or subnets (for example, an internal IP range) can be assumed to be free of attacks (by input from trusted personnel, such as IT professionals), and their results can be prioritized. Certain IP addresses or subnets can be blacklisted, illustrating that their results are less likely to be trusted and should be deprioritized.
[0051] b. The DND manager 1000 can learn which addresses are likely to have a low percentage of attacks and prioritize the results from these addresses. The default thresholds for what to display or not display in the results from a particular source can be changed by the user.
[0052] c. IT personnel can confirm whether a request is an attack or good traffic. This can be stored permanently so there will be no errors in future scans.
[0053] In many cases, particularly commercial web applications, the networked computing device 100 undergoes constant changes and modifications, whether it is hardware and/or software upgrades and/or modifications. In the case of web applications, changes are constantly made to the web page, including certain parameters that could affect the ability to accurately detect good and bad data traffic. When such changes are made, changes generally need to be made to the DND 300 , e.g., its rules and filters, to account for this, which may affect accuracy even after the proper changes were made. The data and rules that define how the DND 300 detects good and bad data are generally stored as profiles in a DND 300 database (not shown). In a preferred embodiment, if changes to a DND 300 profile are warranted, e.g., existing rules fail to detect certain bad traffic types or block certain good traffic types (Decision Block 2600 ), then the DND 300 profile changes are made and uploaded back to the DND 300 (Action Block 2700 ). Through Action Blocks 2100 - 2400 , the DND manager 1000 gains specific knowledge of working attack payloads and vulnerabilities specific to the network computing device 100 . Preferably, the DND manager 1000 includes a library of rule modifications to address the specific attack payloads and vulnerabilities. This enables the DND manager 1000 to automatically create a custom set of improved, more aggressive, rules to detect and block sophisticated attacks not captured by the generic rules of existing DNDs 300 . Moreover, these custom rules may be combined with the pre-existing generic set. Further, specific knowledge of expected good traffic is also gained, thereby enabling the DND manager 1000 to improve the rules that pass through good traffic as well. Example improved rules may include block single and/or double quotes, block parenthesis, block non-ANSI characters, and block letters or numbers as appropriate. Additional example rules generated by the DND manager 1000 in accordance with a preferred embodiment are shown in FIGS. 7 and 8 . FIG. 7 illustrates a rule generated for a Snort DND system 300 from Sourcefire. FIG. 8 illustrates a rule generated for a ModSecurity DND system 300 . After the DND profile change (Action Block 2700 ), the DND manager 1000 will then repeat the testing process in 2000 described above beginning at Action Block 2200 . Preferably, the testing process in 2000 is repeated with both good and bad traffic. A subsequent report may then be generated at Action Block 2500 that reflects the results of the modified rules to assess whether the modified DND 300 rules have improved performance, e.g., whether the DND rules are effective at blocking specific attacks or series of attacks and whether additional good data have been passed through compared to the previous rules.
[0054] For Action Block 2500 , in the case where the networked computing device 100 is a web application and a change to the DND profile was made, the report can provide data and screen captures of the traffic before and after any change is made to the DND profile data.
[0055] The systems and methods described herein will substantially reduce the time required to test and configure DNDs 300 before new blocking rules are implemented to allow them to be in prevention or blocking mode much more frequently, thereby contributing to a more effective security posture. Further, remediation of detected vulnerabilities can be achieved without modifying the network computing device's 100 source code.
[0056] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. For example, the reader is to understand that the specific ordering and combination of process actions described herein is merely illustrative, and the invention may appropriately be performed using different or additional process actions, or a different combination or ordering of process actions. For example, this invention is particularly suited for web-based/Internet/Intranet network security systems; however, the invention can be used for any network security system in general. Additionally and obviously, features may be added or subtracted as desired.
[0057] Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. | The field of the invention relates to systems and methods for securing networked computing devices, and more particularly to systems and methods for testing and managing defensive network systems. In a preferred embodiment, a defensive network management subsystem is included. The subsystem is operatively coupled to a defensive network system and a networked computing system. The defensive network management subsystem is configured to generate test data for the networked computing system, transmit the generated test data to the networked computing system, and record the networked computing system's response to the generated test data. The subsystem is further configured to correlate its recorded data with the defensive network system's response to said generated test data to assess the defensive network system's efficacy. | 7 |
RELATED APPLICATIONS
The present application is a national stage entry according to 35 U.S.C. §371 of PCT application No.: PCT/EP2011/066724 filed on Sep. 27, 2011, which claims priority from German application No.: 10 2010 041 420.4 filed on Sep. 27, 2010.
TECHNICAL FIELD
Various embodiments are based on a light system with increased efficiency. Such light systems are in particular suitable for general lighting.
BACKGROUND
U.S. Pat. No. 6,234,648 discloses a light system, in which blue LEDs and red LEDs are used together with a phosphor, which converts the radiation from the blue LED into green radiation, wherein the phosphor is applied at a distance from the blue LED (so-called remote phosphor concept). One disadvantage with this remote phosphor concept is the fact that the light from the red LEDs likewise needs to pass through the phosphor which acts as converter. As a result of scattering and residual absorption in the green phosphor, efficiency in the red spectral range is lost here.
SUMMARY
Various embodiments provide a light system with the remote phosphor concept which overcomes this disadvantage and manages without any loss in efficiency in the red spectral range. In particular, the emission of red light is intended to be decoupled from the converter without disadvantageously influencing the light mixing.
According to various embodiments, a light system on the basis of a conversion LED and a pure LED, in particular a red LED, is now provided.
In this case, a high degree of efficiency and uniformity of the emission is achieved.
In the case of transmissive remote phosphor approaches with conversion LED and admixing of red using individual red LEDs, the problem arises that the red light needs to be transmitted by the phosphor layer on a carrier. Although the phosphor itself is practically absorption-free in the red spectral range, there is a disadvantage in terms of efficiency in the component part owing to the relatively large optical path length of the red light, more precisely owing to the reflectance of the phosphor layer. Various embodiments composed here increase efficiency.
Approaches to date with remote phosphor homogenize the red light admixed by red-emitting LEDs by virtue of the scattering of the phosphor on the carrier. All of the light-emitting component parts are fitted in a housing, a “light box” with various possible physical shapes. Owing to multiple reflections and scattering of the primary light (in this case in particular blue and red), homogenization takes place. Outside the light system, a homogeneous light emission results. The loss in efficiency of the red light owing to the multiple reflections in the “light box” is accepted.
According to various embodiments, a spatial separation of the blue and red light sources which are realized by a chip or an array of chips is provided. The red light is coupled into the carrier plate or substrate of the phosphor layer. The phosphor layer is in this case preferably applied “at the bottom” on the substrate, i.e. facing the blue light source. The red light is coupled in above the phosphor layer or above the entire substrate.
Particularly preferably, the substrate is so thick that the red chips can be applied to the lateral rim and radiate into the substrate. The carrier layer then acts as an optical waveguide and the scattering on the lower side of the substrate ensures diffuse coupling-out of the red light in the forward direction. In this case, firstly the boundary layer of the substrate at the bottom and secondly the phosphor applied thereto itself acts as reflector/scattering layer.
Alternatively, the array of the red LEDs can also point upwards at an angle in the radiation direction and the mixing takes place in a tubular optical waveguide etc. above the substrate.
One advantage with this arrangement consists in that the red light no longer needs to pass through the phosphor. No multiple reflections take place in the layer or this process is greatly suppressed as a coupling-out mechanism. A single scattering process of a red photon is sufficient for coupling out. Correspondingly, the loss processes occur to a lesser extent, and the efficiency is increased.
A light system is disclosed based on at least two chips, in particular LEDs containing chips, wherein a means for at least partially converting the radiation of a first chip is provided, wherein a layer containing a phosphor as conversion means is mounted in front of a first chip intended for the conversion, which phosphor-containing layer converts at least some of the primary radiation of the first chip into secondary radiation, wherein the second chip emits radiation with a greater wavelength than the first chip, wherein the layer is arranged spaced apart from the first chip, wherein the second chip is arranged in such a way that its radiation is substantially not absorbed by the phosphor.
In a further embodiment, the light system is configured such that the the first chip emits UV to blue, and the second chip emits yellow to red. In the case of a first UV chip, the phosphor is blue-emitting and the second LED is yellow-emitting. In the case of a blue-emitting first chip, the phosphor emits yellow to green, which affects the peak of the emission, and the second chip emits orange, magenta or red.
In a still further embodiment, the phosphor absorbs blue radiation and emits green to yellow radiation.
In a still further embodiment, at least one phosphor is selected from the group consisting of oxinitridosilicates, orthosilicates, sialons, garnets which are derived from YAG:Ce.
In a still further embodiment, the first chip is realized as an array on a substrate.
In a still further embodiment, the layer is applied to a transparent disk in front of the first chip in the radiation direction.
In a still further embodiment, the second chip is realized as an array which has been grouped externally around the rim of the disk and which is arranged in particular above the layer, when viewed in the radiation direction.
In a still further embodiment, the phosphor has a garnet which contains in particular gallium and aluminum.
In a still further embodiment, the light system has a pot-like housing, wherein the first chip is applied to the base of the pot, and wherein the layer acts as a cover for the pot.
In a still further embodiment, the second chip has been inserted upwards at an angle in the radiation direction.
In a still further embodiment, an optical element, in particular an optical waveguide, is applied above the disk, which optical element mixes the radiation of both chips to give white, in particular on the basis of the RGB mixing principle.
In a still further embodiment, the thickness of the substrate is sufficient to be able to arrange the second chips at the lateral rim of the substrate, with the result that the radiation from said chips is coupled into the substrate.
In a still further embodiment, the light system is an LED lamp, wherein the phosphor is applied to a first dome, which arches over the first chips, and wherein the second chips are positioned within a second dome, but at the same time outside the first dome, wherein the second dome has a scattering means for mixing the radiation of both chips.
In a still further embodiment, the LED lamp has a basic part, from which in particular the two domes arch, wherein the basic part has a peripheral circular ring, on which the second chips are mounted.
In a still further embodiment, the second chips are applied externally to the first dome, in particular to strip-like bands.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being replaced upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which:
FIGS. 1A and 1B show a light system in accordance with the prior art;
FIGS. 2A and 2B show a novel light system, first exemplary embodiment;
FIGS. 3A and 3B show a novel light system, second exemplary embodiment;
FIG. 4 shows an LED lamp as a realization of the light system;
FIGS. 5 and 6 each show a further exemplary embodiment of an LED lamp.
DETAILED DESCRIPTION
The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced.
FIGS. 1A and 1B show the design of a light system 1 for white light on the RGB basis as is known per se, see in this regard U.S. Pat. No. 7,213,940, for example. The light source is a semi-conductor component with a blue (b) chip 2 of the type InGaN with a peak emission wavelength of 450 nm, for example. The array furthermore also contains red-emitting (r) LEDs 3 .
The housing 4 is a pot-like light box. This box is closed off at the top by a phosphor layer 6 on a carrier or substrate 5 . The phosphor is in particular garnet, derived from YAG:Ce. The phosphor layer 6 is located “at the bottom”, on that side of the substrate which faces the interior of the light box. A fixed proportion of the blue light is absorbed or converted by the phosphor and the rest of the blue light is scattered. The back-scattering is collected by the light box 4 with a white lining and is reflected again onto the phosphor layer 6 . As a result of the diffuse reflection within the box, homogenization of the light emission is provided.
FIGS. 2A and 2B show a novel arrangement of a light system 1 . Exclusively blue-emitting LEDs 2 are located within the light box 4 . The red LEDs 3 are located at the cover-side rim of the box 4 and are coupled laterally into the carrier or substrate 5 , which is transparent and preferably consists of glass or plastics. The side face 7 of the carrier next to and between the red LEDs 3 is preferably coated with a diffuse reflector material, with a suitable material being TiO 2 , for example. The light-guiding property of the carrier is disrupted “at the bottom” by the phosphor layer 6 . Light is coupled out in the forward direction. The red light is therefore extracted with a single scattering process from the lamp. Multiple scattering processes of the red light are drastically less probable than in the known solution. In principle, the coupling-out of light in tachometer needles or side-illuminated LCD backlights functions in a similar way. The novel feature here is the use of a phosphor which is absorption-free in the red as possible in the layer 6 as a component used for coupling out. Suitable here in particular is a green-emitting phosphor of the type garnet A3B5012: Ce, in particular YAGaG:Ce, which at the same time contains aluminum and gallium. Primarily suitable as component A is Y and/or Lu. Advantageously, a garnet with the cation A=Lu is suitable as phosphor for a peak wavelength of the primary radiation in the range 430 to 450 nm, in particular up to 445 nm, and wherein B at the same time has contents of Al and Ga, in particular contains from 10 to 40 mol. % of Ga, in particular from 20 to 30%, in component B, with the rest being Al.
The carrier element 5 can and should be structured in such a way that the coupling-out of light in the red is adjusted in such a way that an emission is achieved which is as homogeneous as possible and the red light is coupled out as far as possible prior to reaching the lateral wall 8 of the disk which is opposite the individual red LED 3 . Ideally, the path length of the red light is therefore smaller than the diameter of the carrier element or substrate 5 .
This arrangement provides a very compact light source for white light which has good homogenization.
FIGS. 3A and 3B show a further exemplary embodiment, in which the substrate 5 is relatively thin, and in which the red LEDs 3 are fitted above the substrate 5 . They are arranged angled upwards in the radiation direction. A tubular optical waveguide 9 is fitted as optical element above said LEDs, with the inner wall 10 of said optical waveguide having a reflective effect, either as a result of total internal reflection or owing to a reflective coating. In this case, the light is first mixed in the optical waveguide.
Depending on the desired impact direction, such as, for example, as high a color rendering index (CRI) as possible, as high an efficiency as possible, a specific color gamut or a compromise which is desired in any case between these variables, the conversion LED/phosphor/red LED system needs to be adjusted differently, also depending on the desired light color.
The blue LEDs, dominant wavelength at 430 to 470 nm, need to be appropriate for the selected phosphor; preferred are garnets which are derived from YAG:Ce, i.e. A3B5012: Ce, with A=Y and/or Lu being preferred and B=Al and/or Ga being preferred. A cold-white LED (4500 to 5500 K) is mentioned by way of example, with in this case simply YAGaG:Ce with 10% Ga preferably being used, in which case the optimum LED wavelength is about 460 nm (455 to 465 nm). For a cool white neutral white light color (in particular approximately 3800 to 4000 K), YAGaG with a gallium content of 15 to 35%, with the rest being aluminum, should preferably be used. In this case, the optimum LED wavelength is around 450 nm (445 to 455 nm). In the case of a warm white light color (2700 to 3000 K), LuAGaG with a gallium content of 15 to 35%, with the rest being aluminum, should preferably be used. In this case, the optimum LED wavelength is around 438 nm (433 to 443 nm).
Correspondingly, the wavelength of the red LED also needs to be matched. The red proportion of the spectrum should be very predominantly between 600 and 630 nm (dominant wavelength). A narrow-band short-wave emission (preferably FWHM of less than 25 nm) is preferable in respect of high efficiency, but a broadband red emission (preferably FWHM 30 to 50 nm) provides advantages in respect of good color rendering. A relatively long-wave red emission in the range 620 to 650 nm (dominant wavelength) enlarges the achievable color gamut. The influence of a wavelength drift of the red LED is minimal at a dominant wavelength in the range 600 to 610 nm since the maximum for the red sensitivity of the human eye is in this range.
FIG. 4 shows, as a light system, a white-emitting LED lamp 20 , with a basic part 21 which contains electronics, a base 22 attached thereto at the bottom, an inner dome 23 and an outer dome 24 . In a similar manner to as shown in FIG. 2 a , blue-emitting LEDs are introduced on the basic part in the center (not visible; see FIG. 2 a ). The inner dome 23 is uniformly coated with phosphor, which converts some of the primary radiation of the blue LEDs into yellow to green radiation. In particular a garnet such as YaGaG:Ce or LuAGAG:Ce or another garnet of the formula A3B5012: Ce are suitable for this purpose. A plurality of LEDs 28 which emit in a longer wavelength and emit in particular red or magenta or orange are positioned on a collar part 25 of the basic part, adjacent to the rim 26 of the basic part. They are preferably spaced uniformly apart from one another. Particularly preferably, the collar part 25 is realized as a circular ring and is slightly beveled and inclined outwards, as illustrated.
Mixing to give white is performed by means of a diffuser layer or a scattering layer on an outer dome 24 , which surrounds both the inner dome 23 and the circular ring 25 with the red LEDs 28 . Overall this results in a compact white-emitting LED lamp 20 .
FIG. 5 shows a particularly preferred exemplary embodiment of an LED lamp 20 , which has a similar construction to that described in FIG. 4 . In contrast to this, however, the red LEDs 28 are not fitted on the circular ring 25 . Instead, they are mounted in strip-like sections 30 , which are applied on the inner dome 23 and can be free of phosphor. These strip-like sections 30 can be oriented in polar fashion, i.e. virtually along lines of latitude of the dome 23 . In particular, two to four such polar strips 30 can be used, which are spaced uniformly apart from one another. Preferably, in this case a red LED 28 rests on a strip 30 , but it is also possible for two to four red LEDs to be accommodated on such a strip 30 .
FIG. 6 shows a further exemplary embodiment of an LED lamp 20 , in which an equatorial strip 31 is used, which runs peripherally on the inner dome 23 and on which the red LEDs 28 are mounted. In general, it is also possible for a plurality of parallel strips which are oriented along lines of longitude to be used. In this case, in general two to five LEDs can be accommodated on one strip.
The strips can also be oriented at an angle to the lines of longitude or lines of latitude of the inner dome 23 .
While the invention has been particularly shown and described with reference to specific 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 appended claims. The scope of the invention is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced. | A light system based on at least two chips, in particular LEDs containing chips may include at least one first chip capable of emitting a primary radiation, a layer containing a phosphor mounted in front of the first chip, for converting the primary radiation of the first chip into secondary radiation, at least one second chip capable of emitting a second primary radiation with a greater wavelength than the primary radiation, wherein the layer is arranged spaced apart from the first chip, wherein the second chip is arranged in such a way that its radiation is substantially not absorbed by the phosphor. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2006/069584, filed Dec. 12, 2006 and claims the benefit thereof. The International Application claims the benefits of German application No. 10 2006 010 539.7 filed Mar. 7, 2006, both of the applications are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a method for the transmission of program updates for program-controlled devices in a communication network.
BACKGROUND OF THE INVENTION
[0003] A large proportion of electronic devices or equipment is now program controlled (program-controlled devices). For this purpose they contain microprocessors, operating systems and software applications (programs). Examples are personal computers and telephone terminals, but also machine tools, to mention just a few. In many cases this equipment is connected to a communication network.
[0004] as a result of the increasing speed of development cycles, increasing complexity of program-controlled devices and programs, and for rectification of errors frequent updates of the underlying programs (program updates) are necessary.
[0005] To this end a program update must typically be transferred to program-controlled devices of a communication network, e.g. terminals, and activated there. If the program updating is to be performed simultaneously for many program-controlled devices this can result in high peak loads in the communication network during the simultaneous updating. This is especially the case if the program updates involve larger volumes of data.
[0006] Another factor is that program updates can in some cases not be activated without interrupting the operation of the program-controlled devices. A personal computer must thus frequently be shut down and restarted after program updating for example in order to enable the program update to be activated.
[0007] Program updates are transmitted and provided in a very wide variety of ways. Previously they were provided most frequently on data media (e.g. CD-ROM). More recently network-based program updating methods (online update) via a service access of the device or via a connection to a communication network, such as the Internet, have become increasingly widely used.
[0008] Basically three different methods are used to do this:
[0009] In a first manual method the decision about whether and when to update lies entirely in the hands of the user of the program-controlled device. In this case the user selects the program update for the program-controlled device himself via suitable means (such as an Internet Web browser) and thus starts the transmission of the program update. If required, he shuts down the program-controlled device afterwards in order to subsequently restart it so as to activate the program updating. The disadvantage here is that performing the program update lies solely in the hands of the user. This is especially problematic if important—maybe safety-relevant—program updates are not performed by the user.
[0010] A second method runs semi-automatically. In this method either a central server can inform the user about the availability of a new program update or an application that is assigned to the program-controlled device, searches automatically for available program updates, such as in the communication network. If such a program update is found, a request is sent by the application to the user asking whether he or she would like to have the program update transmitted and install it. A disadvantage of this method, particularly in corporate communication networks, is that the method results in peak loads on the communication network at the ends of the day as well as directly after provision of the program update.
[0011] A third method runs fully automatically. In this method available program updates are transmitted under central control to users without consulting the latter. The disadvantage here is that no account is taken of individual user behavior. Another problem can be that uninterrupted availability of the program-controlled device is important to the user in specific situations, but that this is disrupted by the fully-automatically execution of program updating.
[0012] A method is known from publication EP 1 290 586 A2 in which centrally-stored program updates are performed via a communication network. To this end the program update is initially stored in an external device, in order to then be transmitted to a number of decentralized devices.
[0013] An Internet-protocol-based telephone (IP phone) as a terminal is known from publication US 2005/0207432 A1. The publication envisages a terminal which is especially suited for receiving promotional information in conjunction with an integrated search function. To this end the terminal is connected to a server, with the terminal being configured to enable it to receive promotional information from this server. To this end the terminal is equipped with a memory, a processor, a receive device and a transmit device, in order to receive from this server a list of network providers and provider information that match a search request sent by the terminal.
SUMMARY OF THE INVENTION
[0014] The underlying object of the invention is to improve the transmission of program updates. The object is achieved by the characterizing features of the claims.
[0015] The important aspect of the invention is the regular updating of a user profile and a determination of an updating plan for a number of program-controlled devices. The program updating is undertaken with the aid of the determined updating plan.
[0016] The advantages of the invention are,
[0017] that peak loads of communication networks caused by simultaneous transmission of program updates are avoided,
[0018] that interruptions to functions and operation by the activation of the program updating are reduced.
[0019] Advantageous developments are contained in the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The invention will be illustrated below on the basis of two exemplary embodiments and with reference to the enclosed drawing.
[0021] The FIGURE shows in a block diagram those components in a typical communication network KN that are necessary to explain the inventive method for transmission of program updates for program-controlled devices in a communication network.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The exemplary embodiment includes program-controlled devices PGE 1-n (e.g. IP telephones), for which a program update PA is available in the communication network KN.
[0023] To this end statistical information si 1-n about the users of the program-controlled devices PGE 1-n is stored and updated for the program-controlled devices PGE 1-n in user profiles BP 1-n arranged in the communication network KN. These can for example relate to the typical usage times of the program-controlled devices PGE 1-n , e.g. device active. Furthermore information can typically be stored indicating that the respective program-controlled device PGE will be used on a regular basis on weekdays between 8:30 and 16:00 and between 13:00 and 17:45, but never used however in the period between 20:30 and 7:00 or at the weekend or on public holidays.
[0024] Further examples of statistical information si 1-n that can be stored in the user profiles BP 1-n are as follows:
[0025] Upstream data volumes, i.e. the volumes of data that have been sent by the program-controlled device PGE to the communication network KN,
[0026] Downstream data volume, the data volume which has been received by the of program-controlled device PGE from the direction of the communication network KN,
[0027] incoming call if the program-controlled device involved is a telecommunication terminal I,
[0028] outgoing call, likewise if the program-controlled device PGE involved is a telecommunication terminal, or
[0029] User activity (keyboard, mouse, telephone keypad).
[0030] An application APP (in the communication network KN) administers the transmission of the program updates PA to the program-controlled devices PGE 1-n . If there is now a program update PA in the sense of a more current program available in the communication network KN, the application APP sends interrogation information anf-i via the communication network KN to the respective user profile BP 1-n containing at least the information that a program update PA is available. Response information ant-i 1-n is then sent to the application APP by the user profiles BP 1-n implemented in the communication network KN containing information such as the statistical information si 1-n relating to the usage of the program-controlled devices PGE 1-n . This statistical information si contains—as shown above—both statistical information about usage times and also further statistical information such as upstream and downstream data volume, incoming and outgoing calls and user activity.
[0031] The program update PA will then be performed on the basis of this response information, possibly depending on further parameters predetermined by the program-controlled devices PGE 1-n or other components in the communication network KN.
[0032] It is conceivable for example for the following image to be produced for the application APP from the statistical information si 1-n of eight interrogated program-controlled devices PGE 1-n :
[0033] two of these eight program-controlled devices PGE 1-n are never used on a Monday,
[0034] three others are never used after 14:00 on a Friday, and
[0035] three others are never used after 15:00 on a Friday.
[0036] Based on this statistical information si 1-n and on observing matches or deviations, application APP could then form a group. The program update can then be performed jointly in each case for the individual members of the groups.
[0037] Consideration of further parameters—such as the load on the communication network KN to be observed statistically—is also conceivable. In this case for example account can be taken of the fact that the communication network KN, on account of the log-on activity of many users at the start of the working day, is subjected to a particular load between 7:30-9:30.
[0038] A second exemplary embodiment relates to the transmission and subsequent activation of a program update PA to a series of program-controlled devices PGE 1-n (e.g. personal computers) in a communication network KN of a company in accordance with an updating plan APL.
[0039] As soon as a program update PA is available for the program-controlled devices PGE 1 n concerned, an application APP arranged in the communication network KN sends interrogation information anf-i about the availability of the program update PA to the program-controlled devices PGE 1-n . In response to this information each personal computer PGE 1-n involved, depending on the statistical information si 1-n stored for it in the user profile BP, sends response information ant-i 1-n , containing one or more preferred times for the execution of the program update PA. On the basis of all response information ant-i 1-n of the program-controlled devices PGE 1-n involved, the application APP now creates an updating plan APL, that takes into account both the preferred update times of the program-controlled devices PGE 1-n and also the preferred update times for the individual program-controlled devices PGE 1-n in respect of an optimum network utilization of the communication network KN. Finally the program update PA is transmitted via the communication network KN to the individual program-controlled devices PGE 1-n and activated in accordance with this updating plan APL.
[0040] In such cases, after conclusion of the updating plan, APL an acknowledgement can optionally be sent to the users of the program-controlled devices PGE 1-n containing the information that its program-controlled devices PGE 1-n will be updated on day XY at time Z.
[0041] The communication networks KN involved can thus be an Intranet, the Internet, a corporate communication network or a public communication network—PSTN, with synchronization with the corresponding communication protocol to be undertaken in each case.
[0042] The user profiles can be implemented both in the program-controlled device PGE 1-n itself in a memory provided for this purpose and also in the communication network KN—for example in a memory of a server. | The invention is characterized in that a user profile for a program-controlled device is updated on a regular basis. The program is updated in accordance with said user profile. One advantage of the invention lies in the fact that peak loads of communication networks caused by the simultaneous transmission of program updates are avoided. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to packer setting devices. In particular aspects, the invention relates to the design of devices for setting packers using hydrostatic wellbore fluid pressure.
[0003] 2. Description of the Related Art
[0004] Packers are used to create a seal within the annulus of a wellbore between an interior tubular string and the wall of the wellbore. Packers incorporate an elastomeric sealing element that can be radially expanded to set the packer. The packer may also incorporate one or more metallic slip elements that create a mechanical anchorage between the interior tubular string and the wellbore. Commonly, packers are mechanically set by applying an axial force to the sealing element and slip elements to cause them to be expanded radially outwardly and into engagement with the surrounding wellbore wall. A setting tool can be used to do this. Alternatively, fluid can be pumped down the flowbore of the interior tubular string and the fluid pressure used to axially compress the packer element.
[0005] Another method of setting the packer device is by use of hydrostatic pressure. U.S. Pat. No. 6,843,315 issued to Coronado et al., for example, describes a hydrostatically-set packer device having a composite sealing element with large radial expansion capabilities for use in through tubing and open hole applications. This patent is owned by the assignee of the present invention and is, therefore, incorporated by reference. The hydrostatic pressure of the column of fluid within the wellbore is used to provide the setting force for compressing the packer element. However, there are difficulties with the design of setting devices that are used in very deep wells due to the presence of high hydrostatic pressures. In particular, hydrostatic pressures of 20,000 psi or greater are problematic. With such ambient pressures, the setting mechanism can be prone to premature actuation and setting of an associated packer. In addition, certain components of setting devices, such as large volume chambers, are prone to crushing damage at great depths.
[0006] The present invention addresses the problems of the prior art.
SUMMARY OF THE INVENTION
[0007] The invention provides devices and methods for actuating a downhole tool, such as a packer, using hydrostatic pressure as an actuating force. In a preferred embodiment, a packer setting device is used that includes a compressible fluid chamber. In one described embodiment, the compressible fluid chamber preferably includes a plurality of small-diameter hydrostatic chambers that are filled with a compressible fluid at a relatively low or atmospheric pressure. In another embodiment, the compressible fluid chamber comprises a helically coiled tube. In addition, the setting device includes an incompressible fluid chamber that is filled with a volume of substantially incompressible fluid and initially separated from the compressible fluid chamber by a trigger device.
[0008] In operation, the packer setting device provides a buffered setting mechanism as the substantially incompressible fluid is selectively flowed into the compressible fluid chamber to compress the compressible fluid. This fluid transfer causes movement of the setting sleeve so that the associated packer device is set within the wellbore. The substantially incompressible fluid is preferably metered into the compressible fluid chamber along a tortuous, fluid-restrictive flow path to limit the rate of flow of fluid thereby preventing an undesired rapid setting.
[0009] In one embodiment the trigger mechanism is a frangible rupture disc that is destroyed by increasing hydrostatic pressure within the wellbore annulus. In another embodiment, the trigger device is a valve that is actuated from the surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 presents a side, cross-sectional view of an exemplary wellbore having a production string with a packer and packer setting device constructed in accordance with the present invention.
[0011] FIG. 2 is a side cross-sectional view of the packer setting device and associated packer in an unactuated condition within a wellbore.
[0012] FIG. 3 is an enlarged side cross-sectional view of upper portions of the packer setting assembly shown in FIGS. 1 and 2 in an unactuated position.
[0013] FIG. 3A is an enlarged side cross-sectional view of lower portions of the packer setting assembly shown in FIGS. 1 and 2 in an unactuated condition.
[0014] FIG. 4 is an axial cross-sectional view taken along lines 4 - 4 in FIG. 3 .
[0015] FIG. 5 is an axial cross-sectional view taken along lines 5 - 5 in FIG. 3 .
[0016] FIG. 6 is an enlarged side cross-sectional view of upper portions of the packer setting assembly shown in FIGS. 1 , 2 , and 3 , now in an actuated condition.
[0017] FIG. 6A is an enlarged side cross-sectional view of lower portions of the packer setting assembly shown in FIGS. 1 , 2 , and 3 A, now in an actuated condition.
[0018] FIG. 7 is an axial cross-section of upper portions of the packer setting assembly taken along lines 7 - 7 in FIG. 5 .
[0019] FIG. 8 is a side, cross-sectional view of an alternative embodiment for a packer setting assembly in accordance with the present invention wherein the compressible fluid chamber is formed of a spiral-wrapped tube.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] FIG. 1 illustrates an exemplary wellbore 10 that has been drilled through the earth 12 and lined with casing 14 to define an axial flowbore 16 along its length. The flowbore 16 contains a hydrocarbon production string 18 that extends downward therethrough from the surface 20 . Those of skill in the art will understand that the production string 18 is suspended within the wellbore 10 by a wellhead (not depicted). An annulus 21 is defined between the production string 18 and the casing 14 .
[0021] The production string 18 includes a packer setting device 22 that is constructed in accordance with the present invention. A mechanically-set packer device 24 is affixed to the packer setting device 22 . The packer device 24 is moveable between set and unset positions, as is known in the art, by the application of axial force in order to force slips and/or seals radially outwardly from the packer device 24 and into engagement with the flowbore 16 of the wellbore 10 .
[0022] FIG. 2 illustrates the interconnection of the packer setting device 22 to the packer device 24 . Generally, the packer setting device 22 includes a central internal mandrel 26 having upper and lower threaded ends 28 , 30 . The upper threaded end 28 is interconnected to a top sub 32 which, in turn, is interconnected with the production string 18 above the packer device 24 while the lower threaded end 30 is secured to a central body sub 32 of the packer device 24 . The packer setting device 22 also includes a setting sleeve 34 that radially surrounds the internal mandrel 26 and is axially moveable with respect thereto. The setting sleeve 34 presents a lower end 36 that abuts a compression setting ring 38 on the packer device 24 . Axial movement of the setting ring 38 upon inner sub 41 will set a packer element 40 on the packer device 24 .
[0023] FIGS. 3 , 3 A, 4 , 5 , 6 , and 6 A illustrate further details of the packer setting device 22 in greater detail. As can be seen from FIG. 3 , the interior mandrel 26 of the packer setting device 22 defines an interior flowbore 44 . Upper and lower outer housings 46 , 48 radially surround the inner mandrel 26 . The upper and lower outer housings 46 , 48 are affixed to each other via threaded connection 50 . The upper housing 46 contains a pair of axial bores 52 , 54 that are located on diametrically opposite sides of the housing 46 . The bores 52 , 54 are preferably created by drilling from the upper axial end 56 of the upper housing 46 . The upper end of each chamber 52 , 54 is sealed with a pipe plug 58 . As can be seen with further reference to FIG. 4 , each axial chamber 52 , 54 is interconnected with an axial fluid pathway 60 by a lateral flow passage 62 . The lateral flow passage 62 may be created by drilling laterally inwardly and then closing the outer portion of the drilled passage with a plug 64 , as depicted in FIG. 4 . A flow plug 66 is moveably disposed within each bore 52 and 54 , and during run-in, prior to actuation, each flow plug 66 blocks its respective lateral passage 62 , as shown in FIG. 3 . A trigger mechanism 70 is disposed in each bore 52 , 54 below the flow plug 66 and blocks the passage of fluid through the bore. In a currently preferred embodiment, the trigger mechanism is a frangible rupture disc, of a type known in the art, which is designed to block the passage of fluid flow through the bore 52 or 54 and which is designed to fail and rupture in response to a sufficiently high predetermined fluid pressure differential within the bore 52 , 54 . In an alternate embodiment, the trigger mechanism 70 comprises an electronically actuated valve, also of a type known in the art that initially blocks fluid flow through the bore 52 or 54 and can be opened from the surface 20 to permit fluid flow through the bore 52 or 54 . The axial fluid pathway 60 extends downwardly through the upper outer housing 46 to an annular channel 74 that is defined between the upper and lower outer housings 46 , 48 . The use of two (or more) bores 52 , 54 and, therefore, two separate trigger devices 70 is currently preferred in order to allow for redundancy.
[0024] The structure of the lower outer housing 48 is best understood by reference to FIGS. 3 , 5 and 7 . FIG. 5 is an axial cross-section of the housing 48 and indicates by lines 3 - 3 and 5 - 5 how the side cross-sectional views of FIGS. 3 and 5 are taken. FIGS. 3 and 5 illustrate that there are two hydrostatic piston chambers 76 defined within the body of the lower outer housing 48 . Each of the piston chambers 76 is blocked from fluid communication with the annular channel 74 at its upper end by a plug 78 . However, an opening 80 is provided that allows fluid communication between each piston chamber 76 and the annulus 21 surrounding the setting device 22 . In addition, the lower end of each piston chamber 76 has a fluid outlet 82 . A piston 84 is moveably disposed within each piston chamber 76 .
[0025] FIG. 7 shows a different side cross-section of the lower outer housing 48 that is taken along lines 7 - 7 in FIG. 5 . As illustrated a plurality of axial repository blind bores 86 are formed in the body of the housing 48 and disposed in a spaced relation about the circumference of the housing 48 . The blind bores 86 are in fluid communication at their upper ends with the annular channel 74 . It is currently preferred that, prior to run-in, the blind bores 86 be filled with air at atmospheric pressure. It is noted that during run-in and prior to actuation, the repository blind bores 86 remain at atmospheric pressure due to the presence of the trigger devices 70 , which initially isolate the bores 86 from wellbore hydrostatic pressure.
[0026] A narrow annular chamber 88 is defined between the interior mandrel 26 and the upper and lower outer housings 46 , 48 and setting sleeve 34 . The lower end of the chamber 88 , visible in FIG. 3A , adjoins a fluid drain chamber 90 that is formed between the setting sleeve 34 and the interior mandrel 26 . Fluid pathways 92 place the upper end of annular chamber 88 in fluid communication with both bores 52 , 54 . In addition, fluid outlets 82 of the piston chambers 76 are in fluid communication with the annular chamber 88 . The lower end of the larger chamber 90 is enclosed by outwardly-projecting flange 93 and sealed by fluid seal 94 . The upper end of the chamber 90 has a shoulder 89 that projects inwardly from the setting sleeve 34 . The chambers 90 and 88 are, prior to run-in, filled with a substantially incompressible fluid. It is currently preferred that, prior to run-in, a hydraulic fluid, such as a viscous oil, be used to fill the chambers 90 and 88 . This incompressible fluid will also be present within the fluid outlets 82 and piston chambers 76 below the is pistons 84 . In addition, the incompressible fluid will be present within the fluid pathways 92 and the lower ends of bores 52 and 54 , below the trigger devices 70 . It is noted that pistons 84 are in communication with both the wellbore fluid and the substantially incompressible fluid.
[0027] Referring now to FIG. 3 , a body lock ring assembly 96 , of a type known in the art, is provided to ensure one way, ratchet-type motion of the outer housings 46 , 48 and the affixed setting sleeve 34 with respect to the central mandrel 26 . The body lock ring assembly 96 includes a C-ring member 98 that is disposed within a recess 100 between the lower outer housing 48 and the inner mandrel 26 . The radial interior surface 102 of the ring member 98 is corrugated with one-way teeth in a manner known in the art so as to ensure that the housings 46 , 48 and setting sleeve 34 move axially downwardly with respect to the interior mandrel 26 , but not axially upwardly. Fluid within the annular chamber 88 will be able to bleed past the body lock ring assembly 96 because the assembly 96 is not fluid tight and contains at least one break in continuity to form C-ring member 98 . The lower end of the interior mandrel 26 of the packer setting device 22 is affixed by threaded connection 104 to the inner sub 41 of the packer device 24 .
[0028] The packer setting device 22 is operated to set the packer 24 within the wellbore 10 in the following manner. In the instance in which the trigger devices 70 are rupture discs, fluid pressure is increased from the surface 20 within the annulus 21 . The increase in annulus pressure will be communicated through openings 80 and into the piston chambers 76 of the packer setting device 22 . The increased pressure within the piston chambers 76 will act upon the pistons 84 and urge them downwardly within the piston chambers, as depicted in FIG. 6 . As the pistons 84 move downwardly, they increase the pressure of the hydraulic fluid that is enclosed within the fluid pathways 92 and annular chambers 88 and 90 . Once the annulus pressure reaches a predetermined level that is sufficient to rupture the rupture discs 70 , the enclosed hydraulic fluid will flow from the chamber 88 through fluid passages 92 and into the lower ends of both bores 52 , 54 . In so doing, the hydraulic fluid urges the flow plugs 66 upwardly within the bores 52 , 54 to unblock the lateral passages 62 (see FIG. 6 ). Once the lateral passages 62 are unblocked, displaced hydraulic fluid can flow through those passages 62 to axial pathway 60 and into the annular channel 74 . From the annular channel 74 , the hydraulic fluid will enter the lower-pressure blind bores 86 and thereby compress the compressible fluid that is within each of the bores 86 . As the hydraulic fluid enters the repository bores 86 , it is drained from the annular chamber 90 , and this draining action draws the setting sleeve 34 axially downwardly with respect to the interior mandrel 26 and the inner sub 41 of the affixed packer device 24 . The escape of incompressible fluid from the chamber 90 creates a suction effect that essentially draws the shoulder 89 downwardly toward flange 93 and, as a result, setting sleeve 34 moves downwardly with respect to the interior mandrel 26 . This suction force is further used as a setting force as the lower end 36 of the setting sleeve 34 contacts the compression ring 38 and urges it downwardly. The lower end 36 of the setting sleeve 34 contacts the compression setting ring 38 and urges it downwardly, thereby axially compressing and setting the packer element 40 of the packer device 24 . The body lock ring assembly 96 ensures that this downward movement occurs in a ratchet-type one-way fashion. FIGS. 6 and 6A illustrate the set position of the setting device 22 .
[0029] In an embodiment wherein the trigger devices 70 are electronically actuated valves, the setting process is essentially the same. However, in order to begin the setting process, there is no need to pressurize the annulus 21 . Instead, the trigger device valves 70 are actuated from the surface 20 to an open position which will allow the incompressible fluid below them to urge the flow plugs 66 upwardly within the bores 52 , 54 to unblock the lateral passages 62 . The incompressible fluid will then be urged into the blind bores 76 under the impetus of hydrostatic wellbore pressure.
[0030] It is noted that the hydraulic fluid that is enclosed within the chambers 88 and 90 must traverse a tortuous path made up of small flow area fluid passages 92 , 62 and 60 as well as annular channel 74 before it enters the blind bores 86 . The use of this tortuous, flow-restrictive path ensures that setting force is increased gradually within the setting device 22 and does not result in rapid or premature setting of the affixed packer 24 .
[0031] The packer setting tool 22 can be considered to have a compressible fluid chamber which is made up of the plurality of blind bores 86 , the annular channel 74 interconnecting the blind bores 86 , the axial passages 60 , lateral passages 62 . Prior to run-in, the compressible fluid chamber is filled with a compressible fluid, such as air, and this compressible fluid chamber is separated from the incompressible fluid by the trigger devices 70 . The incompressible fluid is initially stored within an incompressible fluid storage volume that is made up, in this described embodiment, of the chambers 88 and 90 as well as the fluid passages 82 , and 92 and the portion of the piston chambers 76 below the pistons 84 . Upon actuation of the trigger devices 70 , the incompressible fluid is released from the storage area and allowed to flood the compressible fluid chamber.
[0032] FIG. 8 depicts portions of an alternative packer setting tool 22 ′. The packer setting device 22 ′ is constructed and operates in the same manner as the packer setting is device 22 except as noted herein. FIG. 8 illustrates a modified upper housing 46 ′ and lower housing 48 ′. As with the housing 46 , the upper housing 46 ′ includes an axial bore 52 that is closed with pipe plug 58 . Fluid passageway 92 interconnects the lower end of the bore 52 with the chamber 88 , and there is a flow plug 66 and trigger device 70 present within the bore 52 . It is noted that, in this embodiment, there is preferably only a single axial bore 52 . Bore 54 is not present.
[0033] The lower housing 48 ′ defines an annular chamber 110 that contains a tube 112 that is wound in a helical fashion to create coils 114 within the chamber 110 . The tube 112 has a closed lower end 116 . The open end 118 of tube 112 is interconnected with the fluid passageway 60 .
[0034] The upper housing 46 ′ also defines within its annular body a plurality of piston chambers 120 (two are shown). The piston chambers 120 have a piston 122 moveably disposed therewithin. Pipe plug 124 blocks the upper axial end of each piston chamber 120 while a lateral fluid opening 126 permits fluid communication with the annulus 21 . A fluid passageway 128 extends from the lower end of each piston chamber 120 to the annular chamber 88 . A substantially incompressible fluid is contained within an incompressible fluid chamber that is formed of the portions of piston chambers 120 below the pistons 122 , fluid passages 120 , the annular chambers 88 and 90 as well as the fluid passageway 92 and the portion of bore 52 below the trigger device 70 .
[0035] A compressible fluid chamber is formed by the helical tube 112 and fluid passageways 60 and 62 . The helical tube 112 is filled with a compressible fluid prior to run-in. The compressible fluid is at a pressure that is lower than the substantially incompressible fluid will be when in the wellbore 10 . The compressible fluid will preferably be at approximately atmospheric pressure when the compressible fluid chamber is filled at the surface 20 . The substantially incompressible fluid is, during run-in and prior to setting, at a pressure that is greater than that of the compressible fluid within the tube 112 since the wellbore hydrostatic fluid is able to exert its ambient hydrostatic pressure upon the substantially incompressible fluid via the pistons 122 .
[0036] In operation, the packer setting device 22 ′ is actuated to set the packer 24 by actuating the trigger device 70 , in a manner described previously. When the trigger device 70 is actuated, the substantially incompressible fluid is flowed, under the impetus of ambient wellbore hydrostatic pressure acting upon pistons 122 , into the compressible fluid chamber to flood the compressible fluid chamber. The packer device 24 is then set by movement of the setting sleeve 34 relative to the interior mandrel 26 , as described previously.
[0037] It is noted that in both packer setting devices 22 and 22 ′, the compressible fluid chamber and the incompressible fluid chambers are defined outside of the interior mandrel 26 , thereby allowing thru-tubing operations to be conducted through the flowbore 44 before, during and after packer setting.
[0038] Those of skill in the art will recognize that numerous modifications and changes may be made to the exemplary designs and embodiments described herein and that the invention is limited only by the claims that follow and any equivalents thereof. | A packer setting device provides a buffered setting mechanism as a substantially incompressible fluid is selectively flowed into a compressible fluid chamber to compress a compressible fluid. This fluid transfer causes movement of a setting sleeve so that an s associated packer device is set within a wellbore. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the treatment of wounds, and particularly to a method of diagnosing and treating oxidative stress-impaired wound healing by testing for oxidative stress, and if present, administering effective amounts of antioxidants and/or Insulin-like Growth Factor 1 (IGF-1).
[0003] 2. Description of the Related Art
[0004] Wound healing is a topic of considerable study. It involves a cycle of connective tissue matrix deposition, contraction, and epithelialization.
[0005] Several overlapping stages can be identified, and these are coordinated by a cascade of cell signaling proteins. Phases include clotting and inflammation, followed by new proliferation and differentiation of cells to fill the wound. The final phase begins by day 7 and includes remodeling of the new tissue, a process that can last for months. Under certain physiological conditions, however, wound healing is delayed, prolonged, or never reaches completion. Among the diseases that are associated with impaired wound healing are diabetes, hypercortisolemia, and chronic inflammation. Among diabetes patients alone, infected/ischemic foot ulcers are estimated to be the reason for about 25% of diabetes-related hospital visits, and precede 84% of lower extremity amputations among diabetes patients. The physiological stresses associated with such diseases as diabetes are believed to deregulate cell signaling and cytokine function at the site of the injury, resulting in improper cell behavior, including a prolonged inflammatory response and increased cell death. However, it has been thought that the final outcome of impaired wound healing can result from very different physiological processes. For example, TNF-α, which is known as a mediator of chronic inflammation, and cortisol (an anti-inflammatory agent that acts through a nuclear receptor) are transduced through different cell signaling pathways, but overabundance of either leads to chronic wounds. The inventors, however, have determined that a common mechanism shared by various types of delayed wound healing is an overabundance of reactive oxygen species (ROS). In diabetes, for example, the hyperglycemic state causes nutritional imbalance among cells at the site of the injury, and also causes oxidative stress. Normal tissue responds to ROS by expressing anti-oxidative stress proteins, such as glutathione, and enzymes that repair chemical damage caused by oxidation, but this response is impaired in the diabetic state.
[0006] The role of IGF-1 in diabetes and oxidative stress has been previously studied. IGF-1 is known to improve glucose disposal in humans. IGF-1 is also known to be a wound healing agent. In fact, the combination of IGF-1 and its binding proteins has been shown to accelerate wound healing in diabetic mice.
[0007] The role of antioxidants in treating the symptoms of diabetes has also been explored. For example, lipoic acid is known in the art to be useful for treating diabetes symptoms, such as retinopathy and neuropathy
[0008] IGF-1 shares partial sequence homology to insulin and is known to some degree to stimulate the same cellular receptors, and, as mentioned above, is also known to improve glucose handling in insulin-insensitive patients. However the biology of IGF-1 is incompletely understood. The tissue distribution of insulin action versus IGF-1 action is only partially overlapping. Although common intracellular signaling proteins are shared, the signaling outputs of insulin and IGF-1 differ in observable ways. For example, insulin may emphasize metabolic responses, while IGF-1 emphasizes mitogenic responses. It has been demonstrated that in particular situations and in particular tissues, insulin and IGF-1 action are not identical. Additionally insulin's role in wound repair has not been clearly delineated, whereas IGF-1 is critical.
[0009] Thus, a method of diagnosing and treating oxidative stress-impaired wound healing solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
[0010] The current invention is a method of predicting wound healing properties. The inventors have found that IGF-1 resistance, that is the inability for IGF-1 to stimulate glucose uptake and/or disposal in a patient to a normal or adequate level, is predictive that wounds suffered by that patient will not heal as quickly as wounds of patients who do not exhibit IGF-1 resistance. Furthermore, a determination that a patient suffers IGF-1 resistance is predictive that a specific therapy will be more efficacious. In a situation in which IGF-1 resistance is not detected, then an antioxidant will not be as effective. In particular, a finding of IGF-1 resistance in a patient calls for administration of an antioxidant in combination with IGF-1 and IGFBP-1. IGF-1 resistance can be assessed by one of a number of methods already established for testing insulin resistance. Numerous such tests have been previously developed; the only requirement is that the test includes the administration to a patient of an amount of IGF-1 that is expected to modulate that patient's glucose handling. For example, it is expected from previous literature that a physiologically effective dose of IGF-1 will cause the patient's body to metabolize glucose at a faster rate than without the administered dose, and that patients suffering from IGF-1 resistance will exhibit a lower increase in glucose metabolism in response to a dose of IGF-1 than patients who do not suffer from IGF-1 resistance.
[0011] Because it was not previously known that a common thread in impaired wound healing is loss of sensitivity to IGF-1, it would not have been obvious to test for IGF-1 resistance before deciding on a course of treatment that includes an antioxidant administered in conjunction with an IGF-1 and IGFBP-1 combination.
[0012] These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1A is a chart showing that IGF-1 induces rapid phosphorylation of Tyr612 on IRS-1, a hallmark of receptor activation, in control fibroblasts and that this phosphorylation is diminished in diabetic fibroblasts or normal fibroblasts exposed to TNF-a or dexamethasone, and that EUK-134 ameliorates the inhibition of IRS-1 phosphorylation caused by these conditions.
[0014] FIG. 1B is a chart showing that IGF-1 activates PI3K; the active subunit of PI3K (p85α) is co-precipitated with IRS-1 in response to IGF-1 exposure, however this association is diminished in diabetic, TNF-α-, or dexamethasone-exposed fibroblasts, and that EUK-134 restores this association.
[0015] FIG. 1C is a chart showing a kinase assay measuring actual enzymatic activity of PI3K. IGF-1 increases PI3K enzymatic activity, whereas a diabetic state, TNF-α exposure, or dexamethasone exposure, diminish activity. This activity is partially restored by co-exposure of the cells to EUK-134.
[0016] FIG. 1D is a chart showing that Akt, a target of PI3K, is phosphorylated (activated) in normal fibroblasts by exposing them to IGF-1, but that this response is diminished in diabetic, TNF-α-, or dexamethasone-exposed cells; Akt phosphorylation is partially restored by EUK-134.
[0017] FIG. 1E is a chart of ELISA (an alternative assay method) results showing that Akt, a target of PI3K, is phosphorylated (activated) in normal fibroblasts by exposing them to IGF-1, but that this response is diminished in diabetic, TNF-α-, or dexamethasone-exposed cells, and that Akt phosphorylation is partially restored by EUK-134.
[0018] FIG. 2A is a chart showing that phosphorylation of IRS-1 at Ser307, which negatively regulates PI3K activity, is elevated in diabetic, TNF-α-, or dexamethasone-exposed cells, but that EUK-134 diminishes Ser307 phosphorylation to levels comparable to the basal level in normal fibroblasts.
[0019] FIG. 2B is a chart showing that basal Jun N-terminal kinase (JNK) activity is higher (as measured by its phosphorylation) in diabetic, TNF-α-, or dexamethasone-exposed cells, and that EUK-134 returns its phosphorylation state to approximate levels found in normal fibroblasts.
[0020] FIG. 2C is a chart showing that reactive oxygen species (ROS) are elevated in diabetic, TNF-α-, or dexamethasone-exposed cells, and that EUK-134 approximately restores normal ROS levels in these cells.
[0021] FIG. 2D is a chart showing that carbonylated protein accumulation (a marker of oxidative stress) is elevated in diabetic, TNF-α-, or dexamethasone-exposed cells versus normal control cells, and that protein carbonylation is returned to approximately normal by exposure to EUK-134.
[0022] FIG. 3A is a chart showing that cell replication in isolated fibroblasts is reduced by diabetes or TNF-α or dexamethasone exposure, but that
[0023] FIG. 3B is a chart showing that proline uptake, a measure of collagen synthesis, is attenuated in diabetic, TNF-α-, or dexamethasone-exposed cells, but that EUK-134 exposure returns it to approximately control levels.
[0024] FIG. 3C is a graph showing that collagen mRNA synthesis is attenuated in diabetic, TNF-α-, or dexamethasone-exposed cells, but that EUK-134 exposure returns it to approximately control levels.
[0025] FIG. 3D is a chart showing that diabetic, TNF-α-, or dexamethasone-exposed cells show decreased contractility in a collagen gel assay, but that EUK-134 exposure partially restores this contractility to control levels.
[0026] FIG. 3E is a chart showing the rate of migration of normal control fibroblasts as well as diabetic, TNF-α-exposed, or dexamethasone-exposed cells, including treatment with IGF-1 or IGF-1 and EUK-134, measured in an artificial wounding assay.
[0027] FIG. 4A is a chart showing the results of a rapid insulin sensitivity assay using IGF-1 instead of insulin for normal control rats, diabetic rats, and rats treated with dexamethasone.
[0028] FIG. 4B is a chart showing that wounds induced on diabetic or dexamethasone-treated rats healed more slowly than on control rats, but that treatment with EUK-134- and/or IGF-1 caused diabetic rat wounds to heal as rapidly as those on control rats.
[0029] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The method diagnoses the risk of a subject of having difficulty with proper wound healing by observing whether the subject has decreased sensitivity to insulin-like growth factor 1 (IGF-1). In particular, if a subject displays resistance to IGF-1, then any wounds the subject suffers can be treated in a different manner than if he or she did not display IGF-1 resistance. In particular, determination that a subject has decreased IGF-1 sensitivity dictates that his or her wounds should be treated with a combination comprising an antioxidant, IGF-1 and IGFBP-1. In particular the antioxidant EUK-134 or the antioxidant a-lipoic acid can be effective as part of the treatment of wounds that have been suffered by individuals with impaired IGF-1 sensitivity.
[0031] Means for determining IGF-1 resistance can be provided by a number of assays. Many of these assays are typically used to administer insulin and monitor the body's response to it; in the case of the instant invention, the insulin is always substituted with IGF-1. Assays include, but are not limited to, hyperinsulinemic-euglycemic clamp technique, frequently sampled IV glucose tolerance test (FSIVGTT), insulin tolerance test (ITT), insulin sensitivity test (IST), and RIST (a Rapid Insulin Sensitivity Test replacing insulin with IGF-1). These tests are familiar to those practiced in the art. These assays for measuring systemic IGF-1 sensitivity (or lack thereof) involve measuring IGF-1's impact on the body through sampling the level of glucose in a subject's blood. In response to a large injected dose of IGF-1, the body of a healthy subject will absorb/metabolize an increased amount of glucose. By also injecting glucose into the blood, and measuring how much glucose is required to stabilize the subject's blood glucose concentration, a practitioner can determine a subject's sensitivity to IGF-1. As mentioned, measurement of IGF-1 resistance is not limited to the tests listed above; any test that has the potential to observably measure a test subject's body's response to a dose of IGF-1 is suitable within the context of this invention. The test must only be able to indicate IGF-1 resistance in a subject, i.e. that a subject responds to a dose of IGF-1 in a manner that is appropriate to a lesser dose of IGF-1.
[0032] Blood glucose metabolism has been studied previously in response to IGF-1 administration. For example SD Boulware et al (“Comparison of the metabolic effects of recombinant human insulin-like growth factor-1 and insulin,” J Clin Invest, Vol. 93, pp. 1131-1139 (1994)) measured glucose metabolism in healthy adults at a steady IGF-1 infusion rate between 0 (i.e. basal) and 0.8 μg/kg-min. Pratipaniwatr et al (2002) measured glucose metabolism in healthy and diabetic adults in response to continuous IGF-1 infusion at 26 pmol/kg-min and 52 pmol/kg-min; they noted IGF-1 resistance in diabetic subjects in addition to insulin resistance. Diabetic patients showed virtually no response to IGF-1 at 26 pmol continuous infusion, whereas they showed about a 40% decrease to IGF-1 at 52 pmol continuous infusion relative to healthy adults. While the two studies above relied on a continuous infusion of IGF-1 during the assay period, it is also possible to inject a single bolus of IGF-1, which is the protocol of a Rapid Insulin Sensitivity Test for example (see, e.g., Patarrão R S et al, 2007). These methods of determining IGF-1 resistance have established standards for a healthy response to IGF-1 administration in humans (see, e.g., Pratipatawanr T et al, “Effect of IGF-1 on FFA and glucose metabolism in control and type 2 diabetic subjects,” American Journal of Physiology—Endocrinology and Metabolism, Vol. 282, pp. E1360-E1368 (2002)).
[0033] Antioxidants such as a-lipoic acid also have an effect on glucose metabolism in humans; for example they are known to improve insulin sensitivity in diabetics. Evidence has also accumulated in data collected from humans and other mammals, however, that antioxidants do not change the glucose sensitivity of healthy patients: therefore such antioxidants return patients to normal rather than generally boosting glucose metabolism irrespective of health or disease (see, e.g., Kainenova, 2006). Antioxidants such as a-lipoic acid or EUK-134 can be administered intravenously or orally in a method of determining IGF-1 resistance.
[0034] Antioxidants can also be administered in an acute intravenous dose in the method of this invention. If a patient who appears to have some level of IGF-1 insensitivity responds to an acute dose of intravenous a-lipoic acid, for example, then the practitioner of the current invention can assume that a disease of IGF-1 resistance is present and that a course of IGF-1 and IGFBP-1 therapy for a wound should include an antioxidant such as, but not limited to, a-lipoic acid or EUK-134. In the case of a-lipoic acid, an acute intravenous dose for initially determining IGF-1 resistance is preferably between about 500 mg and about 2000 mg. IGF-1 resistance can also be determined through chronic administration of α-lipoic acid, either orally or intravenously. The chronic course of therapy can be continued for anywhere between 2 days and greater than 3 months; these protocols are well-known to those of skill in the art. The dose of α-lipoic acid to be taken orally can range anywhere between 1 mg per day and 3000 mg per day for a human; these doses are effective for both determining IGF-1 resistance and for combination therapy in the event a subject suffering IGF-1 resistance incurs a wound. Preferably the dose is between about 100 mg per day and 1000 mg per day. In the method of determining IGF-1 resistance, the practitioner would monitor the patient's IGF-1 sensitivity at any point between 2 days and greater than 3 months after initiating the antioxidant regimen. The practitioner may only require a single IGF-1 resistance test during the course of the chronic dosing regimen, or the practitioner may repeat the IGF-1 resistance test a plurality of times after beginning antioxidant therapy, or may even repeat the entire IGF-1 resistance test a plurality of times. These matters are within the judgment of one of ordinary skill in the biomedical arts.
[0035] Alternatively a practitioner may diagnose IGF-1 resistance by ascertaining the state of IGF-1 signaling at the site of the wound. IGF-1 resistance can be assayed at the site of the wound by biopsy of enough cells to measure phosphorylation status of intracellular transducers of IGF-1 with assays known in the art. Such assays include, but are not limited to, western-blotting, ELISA, and cell-based ELISA. Any assay that can measurably detect protein phosphorylation is suitable within the context of this invention.
[0036] IGF-1 initiates a cascade of signaling inside the cells at the site of a wound, and these signaling cascades promote the healing of the wound. The cells sampled to determine IGF-1 resistance may be taken from directly within the wound or they may come from tissue in the immediate vicinity of the wound. Among the intracellular proteins that mediate the IGF-1 signaling are Insulin Receptor substrate-1 (IRS-1), Jun N-terminal kinase (INK), Akt, and P13 kinase (PI3K). These proteins are able to amplify or inhibit the IGF-1 signal depending on whether, and where, they have been phosphorylated. For example IRS-1 can be phosphorylated on a tyrosine at position 612, which activates the IGF-1 signal, or it can be phosphorylated on a serine at position 307, which will inhibit the IGF-1 signal. Measurement of the phosphorylation status and location of the above transducers of the IGF-1 signal will indicate how readily cells will respond to exposure to IGF-1. Therefore determination of the phosphorylation status of these intracellular proteins in and around the wound are also indicative of “IGF-1 resistance”; and like the IGF-1 resistance that can be measured systemically through a glucose metabolism test, the IGF-1 resistance encountered in cells in and around the site of the wound can be counteracted by antioxidants such as EUK-134 and α-lipoic acid. In determining whether these proteins are responsive to antioxidants, the cells can be removed from the vicinity of the wound and then exposed to antioxidant, i.e. in vitro treatment with antioxidant. Alternatively, cells can be removed from the vicinity of the subject's wound, the phosphorylation/activation status can be determined, then the subject can be treated with antioxidant and further cells can be removed to identify changes in the phosphorylation/activity levels, i.e. in response to in vivo treatment with antioxidant.
[0037] Upon determination that a subject with a wound exhibits IGF-1 resistance, therapeutic amounts of antioxidant, IGF-1 and IGFBP1 can be administered. Therapeutic amounts of IGF-1 and IGFBP-1 range from 0.1 to 1.0 mg/kg given intravenously (see e.g. Regan F M et al, “Treatment with recombinant human insulin-like growth factor (rhIGF)-1/rhIGF Binding Protein-3 complex improves metabolic control in subjects with severe insulin resistance,” J Clip Endocrinol Metab, Vol. 95(5), pp. 2113-2122 (2010)). Topically, concentrations of IGF-1 and IGFBP-1 each can range from 0.1 to 50 μg per ml; the preferred ratio of IGF-1 to IGFBP-1 by mass can range from 10:1 to 1:10. These proteins can be included with any pharmaceutically acceptable carrier or excipient.
[0038] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to apply the disclosed method, and are not intended to limit the scope of what the inventors regard as their invention. The following materials and methods were followed in each of the following Examples 1 through 6, where applicable.
[0039] Primary dermal fibroblasts were obtained from dorsal skin of female Goto Kakizaki (GK, age 12-15 months) rats, a model for non-obese type 2 diabetes, and their Wistar control counterparts. After sterilization in povidine solution, rat skin was washed in sterile water and rinsed in 70% ethanol in PBS. Epidermis and dermis were separated following overnight incubation in 0.25% trypsine/EDTA at 4 C. Dermis was cut into small pieces and incubated in Dulbecco's modified Eagle medium (DMEM; Invitrogen) containing collagenase (250 U/ml; Sigma) for thirty min at 37 C in 5% CO 2 with constant agitation. The sections were triturated vigorously to release fibroblasts, which were collected by centrifugation. The cell pellet was washed two times with PBS, re-suspended in complete medium (DMEM supplemented with 10% fetal calf serum, penicillin (100 U/ml), streptomycin (100 μg/ml)), 2 mM L-glutamine and 10 mM HEPES) and then cultured under a standard condition.
[0040] A hypercortisolemic state was mimicked by exposing control fibroblasts to dexamethasone (Dexa, Sigma) administered at 20 ng/ml every other day for a duration of 8 days. Similarly, the state of low-grade inflammation in fibroblasts was recapitulated experimentally by exposing these cells to TNF-α (4 ng/ml every day for 4 days). EUK (Cayman) and LA (Sigma) were most effective in cultured fibroblasts at 100 μM and 500 μM, respectively, doses that appear to have a minimum effect on cell viability as determined by the WST-based technique (Roche Diagnostics). The concentration of IGF-1 (50 ng/ml, Peprotech) was determined by prior dose response experiment.
[0041] Levels/activities of key intracellular molecules in the IGF-1 signaling cascade including IRS-1, IRS-1Tyr-p-612, PI3K-p85α, IRS-1 Ser-p (307), PI3K, Akt, p-Akt, INK and p-JNK were assessed using western blotting/immunoprecipitation and commercially available ELISA-based assays.
[0042] Ice-cold radioimmunoprecipitation assay (RIPA) buffer was used for the extraction of proteins from fibroblasts. Immunoprecipitation was achieved by incubating cell homogenates with anti-IRS-1 antibody overnight at 4° C. followed by the addition of protein A/G-Agarose for additional two hours. Immunoprecipitates were separated using spin-collection filters (Cytosignal), washed once with RIPA buffer/3× with PBS and then elutated by the addition of Laemmli buffer. Immunoblotting was conducted by loading equal amount of proteins (BCA protein assay kit, Pierce) on a standard 6% or 10% SDS-PAGE and the resolved proteins were transferred to a nitrocellulose membrane; membranes were blocked (1× Tris-buffered saline, 0.1% Tween 20, and 5% nonfat dry milk), incubated overnight, at 4° C. with primary antibodies (IRS-1, IRS-1 Tyr-612, IRS-1 Ser 307, PI3K-p85α Akt, p-Akt, all from Cell Signaling) and then reacted with horseradish peroxidase-conjugated secondary antibodies (1 hr, room temperature). Antigen-antibody complexes were visualized by an enhanced chemiluminescence system on BioMax Light Film (Kodack) and then the densitometry was analyzed using Quantity One 1-D image software (BioRad, GS 800). All densitometry data were corrected for equal loading using the house keeping gene β-actin and they were expressed as fold change vs. control.
[0043] PI3K activity was measured using PI3K ELISA (Echelon Biosciences Inc). This kit was used in connection with anti-p85 PI3K antibody, and it measures class IA PI3K activity as a conversion of PI(3,4,5)P2 into PI(3,4,5)P3. Briefly, cells were washed with buffer A, lysed using buffer A containing 1% NP40 and protease inhibitors, incubated on ice for 30 min and then centrifuged at 14,000×g. Following the step of immunoprecipitation of the supernatants with anti-p85 PI3K antibody and protein A-agarose beads, the kinase reaction was carried out according to the specifications provided by the manufacturers.
[0044] Activation of Akt and JNK was analyzed in fixed fibroblasts using FACE-Akt and FACE-JNK (both from Active Motife). Antibodies recognizing phosphorylated Akt (p-Ser 373) and dually phosphorylated JNK (Thr-183/Tyr-185) or total Akt and JNK were used according to the manufacturer's instructions. Briefly, cells were seeded at a density of 50,000/well in a 96-well plate and the next day the adherent cells were serum starved for 24 hr. Cells were rinsed in PBS and fixed in 3.7% PFA solution for 20 min at room temperature. Labeling with antibodies was conducted according to the manufacturer's protocol and the resulting phosphoantibody signal was calculated after correction for number of cells and total Akt or JNK levels in each sample. The results are shown as -fold change compared to control normal fibroblasts.
[0045] ROS generation in cultured fibroblasts was evaluated using dichloroflurescein-diacetate (DCF-DA, Molecular Probes), a probe that is oxidized to the fluorescent product DCF upon exposure to hydrogen peroxide, peroxynitrite, hydroxyl radical and nitric oxide. Its concentration serves as an indicator of the overall degree of intracellular oxidative stress.
[0046] Cells seeded in 96-well plates were incubated for thirty minutes at 37 C in serum free media containing 5 μM of DCF-DA. The plates were then washed twice with Krebs Ringer Buffer (KR) and the fluorescence readings were taken every 15 min for 1 hr at Ex=485 and Em=530. Subtracted background values were obtained from wells containing DCF-DA without cells. All the values of ROS were normalized to the total number of cells using PI-based assay.
[0047] Protein-bound carbonyl levels in fibroblasts, a marker of cumulative oxidative stress, were determined using a procedure in which a sensitive ELISA-based assay was used to measure total protein-bound carbonyls using oxidized bovine serum albumin (BSA) as standard. Protein samples were adjusted to 5 mg/ml and then incubated with 10 mM 2,4-dinitro-phenylhydrazine (DNP) in 6 M guanidine-HCl. DNP-derivatized proteins were adsorbed to 96-well immunoplates, incubated with primary biotinylated anti-DNP antibody, washed, reacted with streptavidine-biotinylated horseradish peroxidase and then the developed color was measured spectrophotometrically.
[0048] The proliferation and collagen synthesis of cultured fibroblasts were determined using, respectively the 5-bromo-2-deoxyuridine (BrdU) incorporation into DNA and a radiolabelled proline uptake assay.
[0049] Cells were seeded into 96-microtiter plates at a concentration of 1.5×10 4 and allowed to adhere overnight in DMEM supplemented with 10% FCS. After arrest by incubation in DMEM supplemented with 0.5% FCS for 24 hrs, cells were exposed to IGF-I (50 ng/ml) in DMEM containing 10 mM 5-bromo-2-deoxyuridine (BrdUrd). Incorporation of BrdUrd into DNA was estimated using 5-bromo-2-deoxyuridine labeling and detection kit (Roche Applied Science) according to the manufacturer's instructions.
[0050] A radiolabel proline uptake assay was used in the quantification of the rate of collagen synthesis in cultured fibroblasts derived from various experimental groups. Briefly, a confluent fibroblast monolayer was prepared in a 24-well plate and cultured overnight in media supplemented with 10 mM HEPES, 0.1% serum, 2 mM L-proline and 50 μg/ml ascorbic acid. Thereafter, the media was replaced with a fresh media containing 5 μCi/ml. 3 H L-proline (New England Nuclear) and IGF-I (50 ng/ml) and the incubation continues for 24 hrs. Synthesis of collagen and non-collagen protein was expressed, respectively as collagenase-soluble and collagenase insoluble count per minute. A correction factor of 5.4 for non-collagen protein was used to adjust for the relative abundance of proline and hydroxyproline in collagen.
[0051] For in vitro wounding (migration) experiments, cultured fibroblasts were grown in six well plates until they reached confluence. Medium was removed, and cells were rinsed and then cultured for 24 h in serum-free medium plus 0.1% BSA. The monolayer was artificially injured by scratching across the plate with a pipette tip, washed to remove detached cells and then cultured in serum free medium in the presence of mitomyocin C (10 μg/ml, to prevent cell proliferation). After 24 h, images of the scratched area under various experimental conditions were photographed. Scratch wound area was measured and the percentage of wound closure was measured according to the following formula: (1−[current wound size/initial wound size)]×100.
[0052] All animal procedures were performed in accordance with the NIH Guidance for the Care and Use of Laboratory Animals. The current study used, respectively the GK and Dexamethasone-treated rats as models for diabetes and hypercortisolemia. Dexamethasone was administered subcutaneously at a dose of 2.5 μg/kg body weight in the morning (8:00 AM) and in the evening (8:00 PM) for a duration of four weeks before wounding and this form of therapy continued during the course of healing. Preliminary studies involving a concentration-dependent curve revealed that the aforementioned dose of dexamethasone chosen was effective in inducing IGF-1 resistance and also in impairing the healing process without a significant effect on body weight. Weight and age-matched female Wistar rats (Kuwait University breeding colony) served as the conrresponding controls. All of the animals were maintained under standard conditions with 12 hours on/off light cycle, commercial diet, and water ad libitum. GK rats destined for wounding were initially matched with regard to body weight (e.g., 230 to 250 g), and plasma levels of glucose, free fatty acids and insulin. These indices are commonly used to reflect the severity of the diabetic state.
[0053] Animals used for IGF-1 sensitivity (n=6/group) and wound healing (n=8) studies were partitioned into five study groups including control, diabetic, hypercortisolemic, diabetic+EUK and hypercortisolemic+EUK. The EUK-134 was administered for duration of four weeks before wound induction and it continued during the course of healing. EUK-134 at a dose of 12.5 mg/kg body weight was administered intraperitoneally (ip) every other day before and during the wound healing studies; α-lipoic acid (LA), an ROS scavenger/antioxidant enzyme inducer, was alternatively administered at a dose of 50 mg/kg body weight/day.
[0054] IGF-1 sensitivity in control, diabetic and hypercortisolemic animals was determined using the rapid insulin sensitivity test (RIST) with IGF-1 (200 μg/kg BW) infused instead of insulin. The RIST index is the amount of glucose per kg body weight required to maintain euglycemia following a bolus of insulin (50 mU/kg BW).
[0055] Animals derived from various experimental groups were anesthetized by ip, injection of 90 mg ketamine+10 mg xylazine/kg body weight, and their back skin was shaved, depilated with Nair and cleaned with 70% alcohol. Six bilateral full-thickness excisional wounds (8 mm in diameter) at equidistant from midline were created on the dorsorostral back skin. Wounds were separated by a minimum of 1 cm of uninjured skin. The IGF-I therapeutic regimen included a combination of IGF-I and IGFBP-1 (5 μg IGF-I and 1.5 μg IGFBP-1) which was applied every other day to the wound in a vehicle of pluronic acid in phosphate buffered saline solution (300 mg/ml, 250 μl total volume per wound). Wounds were photographed at 0 and 7 days after wounding using a Sony D-9 digital camera. The wound area was analyzed using Adobe PhotoShop (version 7.0; Adobe Systems) and the percentage of wound closure was derived by the following formula: (1−[current wound size/initial wound size])×100.
[0056] Data are expressed as the mean±SEM. One-way analysis of variance with Bonferroni post hock validation or the Mann-Whitney test was used to compare data derived from various experimental groups. A level of P≦0.05 was considered to be significant.
Example 1
[0057] Example 1 represents a study of impaired IGF-1-induced activation of the PI3K/Akt pathway in fibroblasts with phenotypic features of diabetes and hypercortisolemia. Key intracellular molecules within the IGF-1 signaling pathway in fibroblasts, one of the major target cells of IGF-1 during wound healing, were analyzed using immunoprecipitation/western blotting and ELISA-based techniques. In control fibroblasts, 50 ng/ml IGF-I induced rapid and strong activation of IRS-1, as evidenced by the phosphorylation of Tyr-612, an essential element for IRS-1 activation and the generation of a docking site for the downstream PI3K ( FIG. 1A ). IGF-1 also increased the activity of PI3K and promoted the phosphorylation of Akt at Ser-473 in these cells ( FIG. 1B-D ). In contrast, this sequence of events is impaired in fibroblasts with phenotypic features of diabetes and hypercortisolemia ( FIG. 1A-D ). Because baseline levels of p-Akt or p-JNK were not reproducibly detectable using western blotting, a Fast Activated Cell-based (FAC) ELISA kit (Active Motif) was applied with the resulting data documenting a significant decrease in p-Akt/Akt ratio in the aforementioned disease-based models of fibroblasts ( FIG. 1E ).
Example 2
[0058] Example 2 represents a study of the augmented ROS/JNK/IRS-1 Serine 307 axis in fibroblasts with phenotypic features of diabetes and hypercortisolemia. The above-described impairment in the IRS-1/PI3K/Akt signaling cascade in response to IGF-I prompted the investigation of the underlying mechanism of this phenomenon. Initially the phosphorylation status of serine residues of IRS-1, in particular p-Ser (307), was determined. IRS-1 p-Ser (307) serves as a negative feedback regulator by ablating the ability of IRS-1 to activate PI3K-dependent pathways. Data revealed that fibroblasts with diabetic and hypercortisolemic phenotypes exhibit higher levels of IRS-1 p-Ser (307) when compared to corresponding normal control values ( FIG. 2A ).
[0059] IRS-1 contains numerous serine/threonine phosphorylation sites in amino acid sequence motifs, including Ser (307) assessed in the present study. This amino acid is potentially recognized by different kinases including the ROS-sensitive JNK. Accordingly, the ratio of p-JNK/JNK, an indicator of the activity of this MAPK-kinase-based enzyme, was determined using a FAC ELISA kit (Active Motif). The ratio was found to be enhanced in each of the models of IGF-1 resistance ( FIG. 2B ).
[0060] Next it was examined whether a common mechanism underlies the activation of the JNK/IRS-1 p-Ser (307) during diabetes and hypercortisolemia, with a focus on reactive oxygen species (ROS), which are by-products of mitochondrial respiration and enzymatic oxidases. ROS levels in the current study were assessed by determining oxidation of the redox-sensitive dye DCF-DA. This probe is converted into a fluorescent product (DCF) upon reaction with H 2 O 2 , hydroxyl radical, nitric oxide, or peroxynitrite. The resulting ROS signal normalized to total cell number was markedly elevated as a function of diabetes and hypercortisolemia ( FIG. 2C ). Moreover, protein carbonyl levels, a marker of cumulative oxidative stress, were likewise increased in these disease states ( FIG. 2D ).
Example 3
[0061] Example 3 represents a study of attenuation in IGF-1-induced enhancement of collagen synthesis and cell proliferation, migration and contraction in fibroblasts with phenotypic features of diabetes and hypercortisolemia. To investigate the mechanistic basis underlying the contribution of oxidative stress-induced IGF-I resistance to impaired tissue repair mechanism during diabetes and hypercortisolemia, dermal fibroblasts exhibiting the aforementioned pathogenetic features were cultured to study key indices essential for wound healing including collagen production, cell proliferation, migration and contraction.
[0062] A BrdU cell proliferation assay revealed that treatment of control fibroblasts with IGF-1 (50 ng/ml) for 24 hours caused a ˜5-fold increase in BrdU incorporation compared with the medium only control ( FIG. 3A ). This action of IGF-1 in inducing DNA synthesis was reduced in diabetic and hypercortisolemic fibroblasts by about 46%, and 36%, respectively ( FIG. 3A ).
[0063] A radio-labeled proline uptake assay was used to study the impact of IGF-1 on collagen synthesis in fibroblasts of different models of oxidative stress-induced IGF-1 resistance. The data revealed that in control fibroblasts, IGF-1 increased collagen synthesis by about 63%, a phenomenon which was markedly impaired in fibroblasts with diabetic and hypercortisolemic phenotypes ( FIG. 3B ). Consistent with these results, a TagMan real time PCR demonstrated that the increase in COL1A1 mRNA expression by IGF-1 was also suppressed in these cells ( FIG. 3C ).
[0064] The ability of fibroblasts to migrate in response to IGF-I in each of our models of oxidative stress-induced IGF-1 resistance was also evaluated. A linear scratch was made in a fibroblast monolayer reaching confluence using a pipette tip, and fibroblast migration into the wounded area in the presence or absence of IGF-I was monitored over 24 hours, IGF-1-induced migration in dermal rat fibroblasts was markedly reduced as a function of diabetes and hypercortisolemia ( FIG. 3E ). It is worthy of note that the aforementioned phenomenon was associated with an attenuated ability of these cells to contract a floating collagen gel matrix following IGF-I administration ( FIG. 3D ).
Example 4
[0065] Example 4 represents a study of how TNF-α treated fibroblasts recapitulate the hypercortisolemic features of HSOS, IGF-1 resistance and impaired wound healing. The above data clearly indicate that HSOS, IGF-1 resistance and impaired wound healing are characteristic features of diabetes and dexamethasone-induced hypercortisolemia. Dexamethasone signals through a nuclear hormone receptor and is known for its anti-inflammatory effect, while TNF-α, a pro-inflammatory cytokine exerting an effect through a cytokine membrane receptor, has also been associated with insulin resistance. The current study shows evidence for IGF-1 resistance ( FIG. 1A-E ), HSOS ( FIGS. 2C and D) and impaired wound healing ( FIG. 3A-E ) in control fibroblasts exposed chronically to TNF-α. The above data allow some predictions: First, that a clinical condition associated with IGF-1 resistance and impaired wound healing may also show evidence of increased ROS levels, and additionally, that conditions which elicit HSOS (e.g., diabetes, hypercortisolemia, inflammation) would be predicted to cause IGF-1 resistance and impaired wound healing.
Example 5
[0066] Example 5 represents a study of how ROS suppressors ameliorate oxidative stress-induced IGF-1 resistance and impaired wound healing during diabetes, inflammation and hypercortisolemia. To assess whether a cause and effect relationship exists between ROS and IGF-I resistance/impaired wound healing, the ROS suppressors LA and EUK-134 were administered to fibroblasts exposed to the various conditions. EUK-134 is derived from a compound with SOD activity that has been modified to obtain a strong catalase activity and it diffuses freely through the plasma membrane, while LA exhibits dual effects in which it scavenges ROS and enhances the expression of endogenous antioxidant enzymes. The data collected in these studies (only shown for EUK) clearly demonstrate that these antioxidants are able to lessen the HSOS ( FIGS. 2C and D) and to correct the common defect in IGF-1 signaling ( FIG. 1A-E , FIGS. 2A and B) in fibroblasts with diabetic, inflammatory or hypercortisolemia phenotypes. Moreover, this treatment also ameliorates in the aforementioned disease states the impairment in key fibroblast functions essential for wound healing including collagen synthesis, and cell proliferation, migration and contraction ( FIG. 3A-E ).
Example 6
[0067] Example 6 represents a study of the diminution of IGF-1 effects on glucose disposal and cutaneous wound healing during diabetes and hypercortisolemia. This study was intended to extend the above described observations from cellular levels to in viva models of excisional wounds and IGF-1 resistance. Initial data confirmed that diabetic and hypercortisolemic animals exhibited a marked increase in fasting plasma insulin, free fatty acid and glucose (only in GK rats) levels when compared to corresponding control values (Table 1).
[0068] Next, the RIST was used in the assessment of IGF-1 sensitivity (e.g., total amount of glucose, mg/kg body weight needed to maintain euglycemia following IGF-1 infusion) whereas the rate of healing was evaluated using a 7-day full-thickness dermal wound. Our data revealed that IGF-1 sensitivity was markedly reduced as a function of diabetes and hypercortisolemia ( FIG. 4A ). For example, both diabetes and hypercortisolemia induced similar reduction in IGF-1 sensitivity. While untreated rats metabolized 175 mg glucose per kg in response to a bolus injection of 50 mU of IGF-1, rats with diabetic complications or suffering from chemically-induced hypercortisolemia were only able to metabolize about 125 mg glucose per kg body weight, about a 25% to 35% reduction. Chronic administration of lipoic acid or EUK-134 improved the glucose metabolism of diabetic/hypercortisolemic rats in response to a bolus injection of IGF-1 by about 20%.
[0069] Corresponding to the RIST assessments, the in vivo wound healing studies showed that the 7-day diabetic and hypercortisolemic wounds were larger than matching control values ( FIGS. 4B and C). IGF-1-based therapy involving IGF-I/IGFBP-1 at a ratio of 5:1 reduced control, diabetic and hypercortisolemic wound sizes by about 41%, 12% and 17%, respectively ( FIGS. 4B and C). Administration of EUK-134 or □-lipoic acid to diabetic/hypercortisolemic rat wounds resulted in healing rates that are statistically indistinguishable from control rat wounds treated with IGF-1 alone. Interestingly, the above abnormalities regarding lipid and carbohydrate profiles as well as the impairment in systemic and wound-based IGF-1 actions were ameliorated in response to chronic treatment with the ROS suppressors EUK-134 and LA (Table 1 and FIG. 4A-C , data only shown for EUK-134).
[0000]
TABLE 1
Effect of EUK 134 on diabetic and hypercortisolemic rats
Parameters
Cont
Diab
Dexa
Diab + EUK
Dexa + EUK
BW (g)
242 ± 14
237 ± 12
233 ± 10
245 ± 17
240 ± 15
FFA (μM)
283 ± 19
635 ± 22*
706 ± 25*
353 ± 18**
327 ± 16**
FBG (mg/dl)
83 ± 10
137 ± 13*
78 ± 9
122 ± 18
81 ± 12
FPI (ng/ml)
0.52 ± 0.04
0.92 ± 0.08*
0.78 ± 0.061*
0.66 ± 0.05**
0.58 ± 0.052**
Values are the mean ± S.E.M.
Abbreviations: BW: Body weight; FFA: Free fatty acid; FBG: Fasting blood glucose; FPI: Fasting plasma insulin
*Significantly different from corresponding control values at P ≦ 0.05
**Significantly different from corresponding D or HC values at P ≦ 0.05
[0070] 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 following claims. | The method of diagnosing and treating oxidative stress-impaired wound healing allows a practitioner to identify a subject at risk of having impaired wound healing by identifying the sensitivity of that patient to IGF-1. A finding of IGF-1 resistance, either systemically or at the site of an already existing wound, indicates an increased likelihood that the wound will have difficulty healing. In addition, identifying IGF-1 resistance by this method indicates that treatment of a wound with a combination of an antioxidant, IGF-1 and IGFBP-1 will provide optimal healing. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a relief valve structure for an oil pump of an engine of a vehicle, the relief valve being capable of appropriately controlling/switching the discharge pressure and flow rate of oil to an optimum condition in low, middle and high speed regions of the engine.
2. Description of the Related Art
Lubricant oil is supplied to an engine of a vehicle through an oil pump by carrying out engine operation. Most oil pumps are installed with a relief valve for controlling the pressure of the oil. The relief valve device evens out the pressure of the oil by releasing the oil to a different route when the pressure of the oil rises in the oil pump, in order to prevent harmful effects to other devices.
However, relief operation of the relief valve drops the pressure of the oil from high to low without stopping, and therefore the amount of oil supply pulsates without being constant, generating bubbles in the oil. As a result, the relief valve devices tarts vibrating, causing possible harmful effects to the other devices to be supplied with the oil. Therefore, some relief valve devices are designed to return the oil from the relief valve a little bit at a time in the initial stage, in order to prevent rapid drop of the pressure.
Furthermore, recent oil pumps are required to perform more meticulous control. For example, the discharge pressure and flow rate of oil are reduced to realize high efficiency in a certain rotation speed region, but a volume of discharge pressure and flow rate of oil are ensured in order to secure lubrication in another rotation speed region. The requirement of such characteristics is attributed to the following fact. In other words, in the cold months of the year, the engine oil cools down when the engine is not activated.
As a result, the viscosity of the oil increases, and consequently the discharge pressure of the oil pump increases when the engine is started in this state. Then, the discharge pressure of the oil pump reaches the highest level when the engine is rotated to the maximum speed with the cold engine oil. Overly high discharge pressure in such circumstances causes a strain on the oil filter and pipe system, and the amount of unnecessary work increases, causing harmful effects to the abovementioned other devices.
However, in a rotation speed region where the discharge pressure exceeds a predetermined value once and the relief valve is already opened, a conventional relief structure generally cannot control the discharge pressure by further opening the valve. Note that an air vent hole is formed on the deeper side of the relief valve so that the relief valve can smoothly move in the axial direction. The capacity on the deeper side of the relief valve changes significantly as the relief valve moves in the axial direction.
By allowing the air to be drawn/discharged to/from the air vent hole, the relief valve can smoothly move in the axial direction. In other words, the space on the deeper side of the relief valve is in the form of a so-called closed chamber, which is configured such that the volume of the space on the deeper side of the relief valve cannot fluctuate without a hole through which air can pass to the outside. Because the outside of the air vent hole is in the form of an oil pan, there is little difference whether the substance to be drawn/discharge is air or oil.
The prior art documents, Japanese Utility Model Registration No. 2543058 and Japanese Patent Application Publication No. H5-195742, disclose how the discharge pressure is controlled in the relief valve single mechanism (achieving high efficiency by reducing the amount of unnecessary work, as well as a balance between lubricity and reliability by ensuring discharge pressure). Generally, when performing a control for increasing and reducing the discharge pressure in multiple stages, in most cases a plurality of opening parts are provided on a side surface of a valve passage. The relief valves moves in the axial direction as the discharge pressure increases or decreases, whereby the number openings on the side surface of the valve passage increases or decreases, and the area of opening increases to relieve the oil. Consequently, the amount of oil relieved and the discharge pressure can be increased or decreased.
As already described, in an oil pump the discharge pressure and the discharge flow rate are substantially proportional to the rotation speed of the pump. However, from the perspective of the engine system, broadly speaking the required oil pressure and the required oil flow rate are apt to increase logarithmically in relation to the rotation speed (the more the rotation speed increases, the more the increasing rate of the required oil is reduced). In other words, when comparing the discharge pressure of the pump with the pressure required by the engine system on the basis of the rotation speed, the higher the rotation speed is, the greater the deviation of the pump supply pressure and the pressure required by the engine system.
From the phenomenon described above, clearly, it is preferred to carry out a control for gradually increasing the area of opening for relieving the oil (the amount and pressure of oil to be relieved) as the rotation speed increases. In the actual operation, as the discharge pressure rises, the spring shrinks gradually, whereby the relief valve recedes. As a result, the number of through-holes for opening the relief opening parts provided on the side surface of the valve passage increases. Unnecessary amount of work can be reduced by performing the control for further increasing the oil pressure to be relieved (but the discharge pressure is not increased significantly) when the rotation speed increases as described above.
In so doing, the area of opening of each relief opening parts provided on the side surface of the valve passage needs to be larger on the deeper side of the valve. When the area of opening of the relief opening parts is larger on the deeper side of the valve, the oil pressure to be relieved can be further increased as the rotation speed increases. In other words, for example, when the relief opening parts having a larger opening area are arranged on the near side of the valve passage to prevent the increase of the discharge pressure, the oil is relieved first from the relief opening parts with a larger opening area in a middle speed region where the oil does not need to be relieved. Consequently, a large amount of oil is relieved and the discharge pressure is reduced, whereby the lubricity becomes inadequate.
When the oil pump requires a certain level of oil pressure to ensure lubricity and reliability in a certain rotation speed region only, the relief valve that is opened in the middle speed region once needs to be closed again in certain middle to high speed regions higher than the middle speed region, to ensure the oil pressure. In the middle to high speed regions higher than the middle speed region, the relief valve is receded to the further deeper side by high discharge pressure. Therefore, the first relief path 3 of Japanese Utility Model Registration No. 2543058 and the first relief hole 3a of Japanese Patent Application Publication No. H5-195742 that are in “front” of the relief valve opening in the middle speed region cannot be left closed.
Thus, in the piston-shaped valve body 7 of Japanese Utility Model Registration No. 2543058 and the sleeve 7 of Japanese Patent Application Publication No. H5-195742 are disposed to close the first relief path 3 and first relief hole 3a in front of the relief valve at the middle to high speed regions. In other words, the piston-shaped valve body 7 and the sleeve 7 are required in Japanese Utility Model Registration No. 2543058 and Japanese Patent Application Publication No. H5-195742 respectively, as the special members for closing, again, the first relief path 3 of Japanese Utility Model Registration No. 2543058 and the first relief hole 3a of Japanese Patent Application Publication No. H5-195742 that are opened once, in the region of higher rotation speed.
Furthermore, the relief valve is provided with a hole for closing the opened relief opening parts in the middle to high speed regions. For example, this hole is the first valve hole 7B in Japanese Utility Model Registration No. 2543058 and the sleep hole 7a in Japanese Patent Application Publication No. H5-195742. The discharge pressure is controlled by opening and closing these holes with respect to the relief opening parts. In the low speed region where idling is also performed, because the rotation speed is low and therefore the discharge pressure, the oil is not relieved from the relief valve, and all of the relief opening parts are closed.
Thereafter, the relief valve recedes to the deeper side and opens or closes as the discharge pressure increases, the hole provided in the relief valve is located in a position further ahead of the relief opening part that is in the very front part of the low speed region in both Japanese Utility Model Registration No. 2543058 and Japanese Patent Application Publication No. H5-195742. This configuration causes the following problems. Generally, the oil is relieved from the relief opening parts, but when the through-hole provided in the relief valve is positioned in front of the relief opening parts in the axial direction, the oil oozing out of the through-hole of the relief valve cannot reach a sliding surface between the relief valve and the valve passage. As a result, the oil is discharged from the relief opening parts, deteriorating the slidability of the relief valve.
The oil oozing out of the hole provided in the relief valve is discharged from the relief opening parts to the further deeper side and therefore cannot reach the back (deeper side) of the relief valve. Because the oil cannot readily reach the deeper side of the relief valve, the oil pressure on the deeper side of the relief valve decreases. Consequently, the spring located on the deeper side of the relief valve shrinks to a set value or more and slants over a long period of time, reducing its durability.
SUMMARY OF THE INVENTION
Moreover, another special member is required in order to close the relief opening parts again in the middle to high speed regions. An object (technical problem) of the present invention is to appropriately, accurately and reliably control/switch, in an oil pump of an engine of a vehicle, the discharge pressure and flow rate of oil to an optimum condition in low, middle and high speed regions of the engine.
In order to solve the problem described above, as a result of the keen studies, the inventors have arrived at the following invention of claim 1 to solve the problem, the invention being a relief valve structure, having: a relief valve having formed therein a valve flow path for communicating between a valve head part and an outer circumferential side part; a valve housing in which a valve passage accommodating the relief valve is formed; a relief flow-in part formed on an axial direction one end side of the valve passage and communicating with the valve passage; a first discharge part formed in the valve housing and communicating with the valve flow path by the movement of the relief valve; and a second discharge part that is opened by allowing the valve head part to pass therethrough, wherein the second discharge part is positioned nearer to the relief flow-in part than the first discharge part, and the shortest gap between an outer circumferential side part opening of the valve flow path and the first discharge part is the same as or shorter than the shortest gap between the valve head part and the second discharge part during an initial state of the relief valve.
The inventors have arrived at the following invention of claim 2 to solve the problem, the invention being the relief valve structure in claim 1 , wherein the longest gap between the first discharge part and the second discharge part is the same as or shorter than a gap between a boundary position between an inclined surface part of the relief valve and the outer circumferential side part, and a section closest to the valve head part of the outer circumferential side part opening. The inventors have arrived at the following invention of claim 3 to solve the problem, the invention being the relief valve structure in claim 1 or 2 , wherein the outer circumferential side part opening of the valve flow path is formed as an outer circumferential groove formed along a circumferential direction of the outer circumferential side part.
The inventors have arrived at the following invention of claim 4 to solve the problem, the invention being a relief valve structure, having: a relief valve having formed therein a valve flow path for communicating between a valve head part and an outer circumferential side part; a valve housing in which a valve passage accommodating the relief valve is formed; a relief flow-in part formed on an axial direction one end side of the valve passage and communicating with the valve passage; a first discharge part formed in the valve housing and communicating with the valve flow path by the movement of the relief valve; and a second discharge part that is opened by allowing the valve head part to pass therethrough, wherein, at the time of relief operation, the valve flow path and the first discharge part are communicated with each other prior to the start of an operation for allowing the valve head part to pass through the second discharge part, the communication only is established during middle-speed rotation of an engine, the operation for allowing the valve head part to pass through the second discharge part is started during high-speed rotation of the engine, and a transition region where the rotation speed of the engine transits from the middle speed to the high speed has a rotation speed region where relief does not take place.
In the invention of claim 1 , the second discharge part is positioned nearer to the relief flow-in part than the first discharge part, so the first discharge part is positioned on the deeper side in a sliding direction where oil pressure of the relief valve acts. The oil oozing out of the valve flow path into the outer circumferential side part opening functions as a lubricant to allow the relief valve to perform sliding operation in the valve passage more smoothly, improving the durability/reliability of the relief valve.
Moreover, the valve flow path is formed in the relief valve, and the oil flows from the valve head part is continuously supplied into the valve flow path a little bit at a time. Consequently, the deeper side of the relief valve constantly has the oil that serves as a damper to inhibit a spring from shrinking and slanting, whereby the durability of the spring improves.
According to the configuration of the relief valve of the present invention, in the low speed region of the engine, the first discharge part and the second discharge part can be closed, and therefore the oil is not relieved. In the middle speed region of the engine, only the first discharge part and the outer circumferential side part opening of the relief valve can be communicated, and the oil is relieved only from the first discharge part. Furthermore, in the high speed region of the engine, the relief valve slides inside the valve passage and the valve head part passes through the second discharge part, whereby the oil is relieved from the second discharge part. In this manner, relief of the oil can be controlled to an appropriate condition in accordance with the viscosity depending on the humidity of the oil and the engine rotation speed, and appropriate discharge pressure and flow rate of the oil can be obtained in accordance with the engine rotation speed.
According to the invention of claim 2 , especially in the transition region between the middle speed region and the high speed region, both the first discharge part and the second discharge part are closed, and therefore the oil is not relieved. Also, the discharge pressure and flow rate can be increased in the transition region. According to the invention of claim 3 , the outer circumferential side part opening of the valve flow path is the outer circumferential groove part formed along the circumferential direction of the outer circumferential side part. Hence, a more secure communication can be realized between the valve flow path of the relief valve and the first discharge part, regardless of the mounting angle of the relief valve.
According to the invention of claim 4 , at the time of relief operation, the valve flow path and the first discharge part are communicated with each other prior to the start of an operation for allowing the valve head part to pass through the second discharge part, the communication only is established during middle-speed rotation of an engine, the operation for allowing the valve head part to pass through the second discharge part is started during high-speed rotation of the engine, and relief does not take place in a transition region where the rotation speed of the engine transits from the middle speed to the high speed. Therefore, the most appropriate discharge amount and pressure of the oil can be obtained especially in a region of the transition region where the rotation speed of the engine transits from the middle speed to the high speed, the region requiring a discharge amount and pressure of the oil.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a plan view of a pump body having a relief structure of the present invention; FIG. 1B is an enlarged lateral sectional plan view of the relief structure; and FIG. 1C is an enlarged longitudinal sectional side view of the relief structure;
FIG. 2A is an enlarged lateral sectional plan view showing a substantial part of the relief structure; FIG. 2B is an enlarged plan view showing a substantial part of a partial cross section of a valve housing; and FIG. 2C is an enlarged lateral sectional plan view showing a substantial part of the valve housing;
FIG. 3A is a cross-sectional view taken along the arrow Xa-Xa of FIG. 1 ; FIG. 3B is a cross-sectional view taken along the arrow Xb-Xb of FIG. 1 ; FIG. 3C is a cross-sectional view taken along the arrow Xc-Xc of FIG. 1 ; FIG. 3D is a longitudinal sectional side view of the relief valve; and FIG. 3E is a perspective view of the relief valve;
FIG. 4A is a lateral sectional plan view showing a substantial part of the valve housing; and FIG. 4B is a plan view showing a substantial part of FIG. 4A ;
FIG. 5A is an action diagram of an initial stage of a relief operation; FIG. 5B is an action diagram of a low speed region obtained during the relief operation; and FIG. 5C is an action diagram of low-speed rotation to middle-speed rotation taken place during the relief operation;
FIG. 6A is an action diagram of a middle speed region obtained during the relief operation; FIG. 6B is an action diagram of middle-speed rotation to high-speed rotation taken place during the relief operation; and FIG. 6C is an action diagram of a high speed region obtained during the relief operation;
FIG. 7A is an enlarged view showing a state in which an outer circumferential side part opening is communicated with a first discharge part and consequently oil is fed to the first discharge part during a relief valve operation when the longest gap Sc is smaller than a gap U; FIG. 7B is an enlarged view showing a state in which the first discharge part and a second discharge part are both closed during the relief operation; and FIG. 7C is an enlarged view showing a state in which an operation of allowing a valve head part to pass through the second discharge part is started so that the second discharge part can carry out the relief operation;
FIG. 8 is a graph showing the characteristics of the present invention; and
FIG. 9A is an enlarged view showing a state in which the outer circumferential side part opening is communicated with the first discharge part and consequently the oil is fed to the first discharge part during the relief valve operation when the longest gap Sc is larger than the gap U; FIG. 9B is an enlarged view showing a state in which both the first discharge part and the second discharge part can carry out the relief operation during the relief operation; and FIG. 9C is an enlarged view showing a state in which the first discharge part is closed and only the second discharge part can carry out the relief operation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, embodiments of the present invention will be described with reference to the drawings. A pump body 1 is configured along with a pump cover that is not shown. A rotor chamber 11 is formed inside the pump body 1 . Specifically, a concave part is formed in the pump body 1 , and the concave part is configured as the flat cylindrical hollow rotor chamber 11 when the pump cover is fixed to the pump body 1 . In the rotor chamber 11 , an outer rotor 91 provided with internal teeth and an inner rotor 92 provided with external teeth are meshed with each other and mounted in a decentered manner. The outer rotor 91 and the inner rotor 92 are shown by the imaginary lines (two-dot chain lines) in FIG. 1 .
Specifically, in the outer rotor 91 and the inner rotor 92 , the teeth of the inner rotor 92 are formed along a trochoidal curve. The number of teeth of the inner rotor 92 is less than the number of teeth of the outer rotor 91 by one. When the inner rotor 92 rotates once, the outer rotor 91 rotates with a delay of one tooth. At any angle of rotation, the tooth tips of the inner rotor 92 are constantly in contact with the tooth tips or tooth bases of the outer rotor 91 . A plurality of space parts are formed between the outer rotor 91 and adjacent tooth tips of the inner rotor 92 , and each of the space part draws oil from an intake port 12 and discharges the oil to a discharge port 13 to circulate the oil throughout the devices, by expanding or shrinking in one rotation.
Next, a relief valve device is configured by a valve housing 3 and a relief valve 6 , as shown in FIGS. 1B , 1 C and FIG. 2 . A valve passage 31 in which the relief valve 6 slides is formed in the valve housing 3 , and the relief valve 6 slides inside the valve passage 31 . The valve housing 3 and a relief flow-in part 2 are formed integrally, and the relief flow-in part 2 and the valve passage 31 are communicated with each other. Specifically, an axial direction one end of the valve passage 31 is communicated with the relief flow-in part 2 . The valve housing 3 is formed into a substantially cylindrical shape in a predetermined position inside the pump body 1 , in a bulging manner (see FIG. 3 ).
A branch path 13 a is formed in the discharge part 13 , and the branch path 13 a and the relief flow-in part 2 are communicated with each other (see FIGS. 1 and 2 ). When the pressure of discharge oil within the discharge port 13 increases, fluid is fed from the branch path 13 a to the valve passage 31 via the relief flow-in part 2 to press and move the relief valve 6 along an axial direction, whereby a relief operation is carried out.
The inner diameter of the relief flow-in part 2 and the inner diameter of the valve passage 31 are different. A step is formed between the valve passage 31 and the relief flow-in part 2 due to the difference between the diameters, and this step section functions as a relief flow-in closing surface 33 for a section on the valve passage 31 side where the relief valve 6 and the relief flow-in part 2 are communicated with each other (see FIGS. 2A and 2B ). The position of the relief flow-in closing surface 33 , that is, the boundary line between the relief flow-in part 2 and the valve passage 31 , is called “start end part 31 a of the valve passage 31 ,” which is the reference position of the valve passage 31 . An initial state of the relief valve 6 is a state in which the head part of the relief valve 6 abuts on the relief flow-in closing surface 33 (see FIGS. 1B , 1 C, and FIG. 2A ).
As shown in FIG. 1 , in substantially an intermediate position in the axial direction of the valve housing 3 , a first discharge part 4 and second discharge part 5 are formed in different positions in the axial direction. The substantially intermediate position of the valve passage 31 includes the entire range except for the part near both ends of a passage direction. The first discharge part 4 and the second discharge part 5 are the sections for establishing a communication between the inside and the outside of the valve passage 31 , wherein the second discharge part 5 is positioned nearer to the relief flow-in part 2 than the first discharge part 4 , that is, in the position near the relief flow-in closing surface 33 (see FIG. 4 ).
The first discharge part 4 is formed as a small-diameter through-hole for forming a communication between the inside and the outside of the valve passage 31 of the valve housing 3 . The diameter of the hole of the first discharge part 4 is equal to (or substantially equal to) the groove width of an outer circumferential side part opening 63 a of the relief valve 6 , which will be described hereinafter. Furthermore, the first discharge part 4 is formed along a direction diagonal to the valve housing 3 (see FIG. 3A ). The second discharge part 5 is formed in a position near the relief flow-in part 2 in the passage direction of the valve passage 31 (see FIG. 1A , FIG. 2B , FIG. 3C and FIG. 4 ). The second discharge part 5 is configured by a small opening part 51 and large opening part 52 , wherein the small opening part 51 is formed nearer to the relief flow-in part 2 than the large opening part 52 (see FIG. 4 ).
Two of the second discharge parts 5 are formed substantially symmetrically in a direction perpendicular to the axial direction of the valve housing 3 , that is, in a width direction, with an appropriate space therebetween (see FIG. 4B ). A remaining wall part 53 formed integrally with the valve passage 31 is provided between the second discharge parts 5 , 5 , wherein the remaining wall part 53 continues to a part of the valve passage 31 and functions as a guide holding part of a moving operation of the relief valve 6 in the section of the second discharge part 5 .
Also, from the perspective of intensity, the small opening part 51 is preferably formed along the remaining wall part 53 so that the rigidity of the valve housing 3 can be maintained in the second discharge part 5 . In addition, the remaining wall part 53 functions as a guide when the relief valve 6 passes through the second discharge part 5 . In other words, when the relief valve 6 moves from the small opening part 51 of the second discharge part 5 to the large opening part 52 and thereby the relief oil is discharged, the relief valve 6 within the valve housing 3 is apt to incline (fall over) toward the large opening part 52 due to the flow and pressure of the oil.
However, because the remaining wall part 53 also functions as a guide for securely preventing the relief valve 6 from abutting on the remaining wall part 53 and fall over when moving from the small opening part 51 to the large opening part 52 , calling between the relief valve 6 and the large opening part 52 can be securely prevented even when the large opening part 52 is formed relatively large. The large opening part 52 is formed as a substantially rectangular opening section. Further, the small opening part 51 is formed relatively smaller than the large opening part 52 (see FIG. 4B ). The large opening part 52 is formed to extend from a top part 32 a of the housing 3 toward a bottom part 32 b in a width direction both side section of the valve housing (see FIG. 3C ).
As shown in FIGS. 3D and 3E , the relief valve 6 is configured by an outer circumferential side part 61 and a valve head part 62 , wherein the valve head part 62 has an inclined surface part 62 b formed on an outer circumferential rim of a head top part 62 a . The outer circumferential side part 61 is configured to be in substantially close contact with an inner circumferential surface of the valve passage 31 and to be able to slide smoothly. The relief valve 6 accommodated in the valve housing 3 is constantly biased elastically toward the relief flow-in part 2 of the valve passage 31 by a spring 7 mounted in the valve passage 31 , and the valve head part 62 of the relief valve 6 is brought into abutment against the relief flow-in closing surface 33 of the valve passage 31 (see FIGS. 1 and 2 ). In the axial direction of the relief valve 6 , a spring support shaft part 64 is formed on the other side of the valve head part 62 , and the spring 7 is supported by the spring support shaft part 64 . More specifically, the inclined surface part 62 b of the valve head part 62 is brought into abutment against the relief flow-in closing surface 33 . Therefore, non-relief operation state is obtained.
By forming the inclined surface part 62 b on an outer circumference of the valve head part 62 of the relief valve 6 , foreign matters mixed into the oil can be swept away from the second discharge part 5 at once by the inclined surface part 62 b . A substantially truncated conical shape is configured by the head top part 62 a and the inclined surface part 62 b . A valve flow path 63 is formed between the valve head part 62 a and the outer circumferential side part 61 . In the valve flow path 63 , within the relief valve 6 , a horizontal flow path 63 c is formed to extend from the valve head part 62 along the axial direction, and a vertical flow path 63 d perpendicular to the horizontal flow path 63 c is formed, with the horizontal flow path 63 c in the middle.
The horizontal flow path 63 c is communicated with a head part opening 63 b formed in the valve head part 62 , and the vertical flow path 63 d is communicated with the outer circumferential side part opening 63 a of the outer circumferential side part 61 , whereby the head part opening 63 b and the outer circumferential side part opening 63 a are communicated with each other. In the outer circumferential side part 61 , the outer circumferential side part opening 63 a is formed as an outer circumferential groove along the circumferential direction of the outer circumferential side part 61 . In other words, a groove passing through an opening hole of the vertical flow path 63 d is formed along the circumferential direction of the outer circumferential side part 61 . The opening of the vertical flow path 63 d is positioned in a groove bottom part of the outer circumferential side part opening 63 a formed as the outer circumferential groove (see FIGS. 2C and 3E ).
The oil that is fed through the horizontal flow path 63 c and the vertical flow path 63 d flows out to the outer circumferential side part opening 63 a formed as the outer circumferential groove, and is fed to the first discharge part 4 when the relief valve 6 slides within the valve passage 31 and the outer circumferential side part opening 63 a is communicated with the first discharge part 4 (see FIGS. 5C and 7A ). One end of the spring 7 in a longitudinal direction is mounted on the rear part side of the relief valve 6 , and the other end is fixed by a holding member 8 mounted in the valve passage 31 (see FIGS. 1B and 1C ). In the state in which the outer circumferential side part opening 63 a of the relief valve 6 reaches the position of the first discharge part 4 formed in the valve housing 3 , the valve flow path 63 and the first discharge part 4 are communicated with each other (see FIGS. 5C and 7A ).
The relief valve 6 is configured such that, in its initial state, that is, when the valve head part 62 abuts on the relief flow-in closing surface 33 of the valve passage 31 , the shortest gap Sa in the axial direction between the outer circumferential side part opening 63 a of the valve flow path 63 and the first discharge part 4 is smaller than the shortest gap Sb in the axial direction between the valve head part 62 and the second discharge part 5 (see FIG. 2 ). In other words, Sb>Sa is established. Here, the shortest gap Sa between the outer circumferential side part opening 63 a and the first discharge part 4 is the shortest gap in the gap between a section that is on an opening rim of the outer circumferential side part opening 63 a , which is closest to the first discharge part 4 along the axial direction, and a section that is on an opening rim of the first discharge part 4 , which is closest to the outer circumferential side part opening 63 a along the axial direction.
Moreover, the shortest gap Sb is the shortest gap in the gap between a section that is on an opening rim of the second discharge part 5 , which is closest to the valve head part 62 along the axial direction, and the valve head part 62 . In other words, this shortest gap is the gap between the second discharge part 5 and a boundary 6 k position between the inclined surface part 62 b and the outer circumferential side part 61 (see FIG. 2 ). As described above, in the initial state of the relief valve 6 , the shortest gap Sa between the outer circumferential side part opening 63 a of the valve flow path 63 and the first discharge part 4 is made shorter than the shortest gap Sb between the valve head part 62 and the second discharge part 5 , whereby first the outer circumferential side part opening 63 a and the first discharge part 4 can be communicated with each other as the relief valve 6 slides, and the relief operation can be taken place (see FIG. 7A ). Subsequently, the operation of allowing the valve head part 62 to pass through the second discharge part 5 is started, whereby the second discharge part 5 can perform the relief operation (see FIG. 7C ).
In addition, when the space between the boundary 6 k position between the inclined surface part 62 b and the outer circumferential side part 61 and a rim section on the outer circumferential side part opening 63 a that is closest to the valve head part 62 is obtained as a gap U, the longest gap Sc between the first discharge part 4 and the second discharge part 5 is made shorter than the gap U (see FIG. 4 ). Alternatively, the longest gap Sc can be made equal to the gap U. In other words, Sc≦U can be established. Here, the longest gap Sc is the gap between a section that is an opening rim of the first discharge part 4 , which is farthest from the second discharge part 5 along the axial direction, and a section that is on an opening rim of the second discharge part 5 , which is farthest from the first discharge part 4 along the axial direction. In other words, this gap is the gap between the sections that are farthest from (or have the longest distance between) the first discharge part 4 and the second discharge part 5 (see FIG. 4B ).
By adding the condition where the longest distance Sc the gap U is established to the condition where the shortest gap Sb>the shortest gap Sa is established, first the outer circumferential side part opening 63 a is communicated with the first discharge part 4 as the relief valve 6 slides within the valve passage 31 from the initial state (where the first discharge part 4 and the second discharge part 5 are closed), whereby the relief operation can be carried out in the first discharge part 4 (see FIG. 7A ).
Next, when the relief valve 6 continues sliding, both the first discharge part 4 and the second discharge part 5 enter the closed state (see FIG. 7B ). When the relief valve 6 further continues sliding, the valve head part 62 passes through the second discharge part 5 , and the inside and the outside of the valve passage 31 are communicated with each other via the second discharge part 5 (see FIG. 7C ), whereby the relief operation can be started. Under the conditions previously described, the first discharge part 4 and the second discharge part 5 cannot perform the relief operation at the same time.
In addition, sometimes the longest gap Sc between the first discharge part 4 and the second discharge part 5 is made larger than the gap U between the boundary 6 k position between the inclined surface part 62 b and the outer circumferential side part 61 and the rim section on the outer circumferential side part opening 63 a closest to the valve head part 62 . In other words, Sc>U is established. In this case, first the outer circumferential side part opening 63 a is communicated with the first discharge part 4 as the relief valve 6 slides within the valve passage 31 from the initial state (where the first discharge part 4 and the second discharge part 5 are closed), whereby the relief operation can be carried out in the first discharge part 4 (see FIG. 9A ). When the relief valve 6 further continues sliding, the relief operation is started in the second discharge part 5 while the relief operation is being performed by the first discharge part 4 (see FIG. 9B ). In other words, the relief operation of the first discharge part 4 is carried out previously, but thereafter the relief operation can be performed by the first discharge part 4 and the second discharge part 5 at the same time. When the relief valve 6 further continues sliding, the first discharge part 4 enters the closed state, and the relief operation is performed only by the second discharge part 5 (see FIG. 9C ).
In its initial state, that is, when the valve head part 62 abuts on the relief flow-in closing surface 33 of the valve passage 31 , the shortest gap Sa in the axial direction between the outer circumferential side part opening 63 a of the valve flow path 63 and the first discharge part 4 is sometimes equal to the shortest gap Sb in the axial direction between the valve head part 62 and the second discharge part 5 . In other words, Sb=Sa is established. Moreover, the longest gap Sc between the first discharge part 4 and the second discharge part 5 is sometimes equal to the gap U between the boundary 6 k position between the inclined surface part 62 b and the outer circumferential side part 61 and the rim section on the outer circumferential side part opening 63 a closest to the valve head part 62 . In other words, Sc=U is established. Therefore, when the shortest gap Sa is equal to the shortest gap Sb and the longest gap Sc is equal to the gap U, the relief operation of the first discharge part 4 and the relief operation of the second discharge part 5 are started simultaneously by communicating the outer circumferential side part opening 63 a and the first discharge part 4 with each other and allowing the valve head part 62 to pass through the second discharge part 5 .
The relief operation according to the present invention will be described next. The oil pump according to the present invention is activated by receiving rotation of the engine that is not shown). When the relief operation is not necessary during engine shutdown or low-speed rotation, the valve head part 62 of the relief valve 6 is brought into abutment against the relief flow-in closing surface 33 (initial state) (see FIG. 5A ). Moreover, the outer circumferential side part opening 63 a of the relief valve 6 is positioned between the second discharge part 5 and the first discharge part 4 along the axial direction, from the relief flow-in closing surface 33 . In addition, the first discharge part 4 and the second discharge part 5 are closed by the relief valve 6 .
When the engine is started, the oil pressure in the low speed region is such that, although the relief valve 6 slides slightly, the relief operation does not take place because the first discharge part 4 and the second discharge part 5 are closed (see FIG. 5B ). In the transition region between the low speed region and the middle speed region of the engine, the pressure of the oil discharged from the discharge port 13 rises, and the oil pressurizes the valve head part 62 to allow the relief valve 6 to start sliding. By allowing the relief valve 6 to slide, the outer circumferential side part opening 63 a reaches the position of the first discharge part 4 , whereby the outer circumferential side part opening 63 a and the first discharge part 4 are communicated with each other. The oil is relieved for the first time from the valve flow path 63 of the relief valve 6 via the outer circumferential side part opening 63 a and the first discharge part 4 (see FIG. 5C ). When the outer circumferential side part opening 63 a and the first discharge part 4 are communicated with each other, the second discharge part 5 is still in the closed state. Therefore, the increasing rate of the discharge pressure becomes moderate, and therefore the discharge pressure does not increase dramatically. In the middle speed region of the engine, the position of the first discharge part 4 completely matches the position of the outer circumferential side part opening 63 a (see FIG. 6A ).
Next, in the transition region between the middle speed region of the engine and the high speed region, the relief valve 6 further slides, and the outer circumferential side part opening 63 a is separated from the first discharge part 4 . In other words, the communication between the outer circumferential side part opening 63 a and the first discharge part 4 is released, and the first discharge part 4 is closed, meaning that the relief operation by the first discharge part 4 is stopped (see FIG. 6B ). Moreover, in this region the second discharge part 5 is in the closed state. Therefore, in the middle speed region, the oil is not relieved at all. As a result, the increasing rate of the discharge pressure increases, whereby the discharge pressure rises. The graph in FIG. 8 shows the increase of the oil pressure in the transition region having the abovementioned rotation speed.
Subsequently, in the high speed region of the engine, the relief valve 6 further slides, and the valve head part 62 reaches the second discharge part 5 , whereby the second relief operation takes place (see FIG. 6C ). At this moment, the first discharge part 4 is closed. The second relief operation is carried out between the valve head part 62 and the second discharge part 5 configured by the small opening part 51 and the large opening part 52 as described above. The amount of oil returned by the relief operation increases, the increasing rate of the discharge pressure becomes moderate, and the discharge pressure is gently increased by the increase in the engine rotation speed.
When the position of the valve head part 62 starts passing through the small opening part 51 of the second discharge part 5 , the oil is gradually relieved from the small opening part 51 . At this moment, the amount of oil relieved from the small opening part 51 is very small. Moreover, when the relief valve 6 is pressurized by a high pressure, the relief valve 6 moves, and the valve head part 62 reaches the large opening part 52 , increasing the amount of oil relieved. In this manner, the amount of oil relieved increases from the small opening part 51 to the large opening part 52 .
The graph in FIG. 8 shows that the increase of the oil pressure changes gently and that the increasing rate drops in the relief operation between the low-speed rotation and the middle-speed rotation of the engine. Moreover, in the transition region between the middle speed region and the high speed region, the relief operation is not performed by the first discharge part 4 or the second discharge part 5 , and therefore the increasing rate of the oil pressure is high. Particularly, the graph shows that oil discharge pressure increases in the transition region where the discharge pressure and discharge amount need to be increased, and therefore that a significant oil flow rate can be ensured. | To provide a relief valve structure for an oil pump, which is capable of appropriately controlling/switching the discharge pressure and flow rate of oil to an optimum condition in low, middle and high speed regions of an engine. The relief valve structure has: a relief valve having formed therein a valve flow path for communicating between a valve head part and an outer circumferential side part; a valve housing in which a valve passage accommodating the relief valve is formed; a relief flow-in part formed on an axial direction one end side of the valve passage and communicating with the valve passage; a first discharge part formed in the valve housing and communicating with the valve flow path by the movement of the relief valve; and a second discharge part that is opened by allowing the valve head part to pass therethrough. The second discharge part is positioned nearer to the relief flow-in part than the first discharge part. The shortest gap between an outer circumferential side part opening of the valve flow path and the first discharge part is the same as or shorter than the shortest gap between the valve head part and the second discharge part during an initial state of the relief valve. | 8 |
BACKGROUND
[0001] 1. Field
[0002] Exemplary embodiments of the present disclosure relate to skinning of honeycomb bodies and, more particularly, to inspection of skinned honeycomb bodies and control of skinning honeycomb bodies.
[0003] 2. Discussion of the Background
[0004] After-treatment of exhaust gas from internal combustion engines may use catalysts supported on high-surface area substrates and, in the case of diesel engines and some gasoline direct injection engines, a catalyzed filter for the removal of carbon soot particles. Filters and catalyst supports in these applications may be refractory, thermal shock resistant, stable under a range of pO 2 conditions, non-reactive with the catalyst system, and offer low resistance to exhaust gas flow. Porous ceramic flow-through honeycomb substrates and wall-flow honeycomb filters (generically referred to herein as honeycomb bodies) may be used in these applications.
[0005] Particulate filters and substrates may be difficult to manufacture to external dimensional requirements set by original equipment manufacturers (OEMs) and the supply chain due to drying and firing shrinkage during manufacturing. Consequently, ceramic cement may be used to form an exterior skin of a honeycomb body which has been machined or “contoured” to a desired dimension. As used herein, the term “honeycomb body” includes single honeycomb monoliths and honeycomb bodies formed by multiple honeycomb segments that are secured together, such as by using a ceramic cement to form a monolith. Ceramic cement may be mixed and applied to a fired, contoured or segmented honeycomb body and the wet skin allowed to dry. The act or process of applying ceramic cement to the exterior of the honeycomb body is referred to herein as “skinning” the honeycomb body. A honeycomb body having skin disposed thereon is referred to herein as a “skinned” honeycomb body.
[0006] Once the wet skin on the honeycomb body has dried an inspection of the skin can be conducted requiring labor, cost, and time. When a defect is found it may be too late to correct a skinning process that caused the defect in sequential parts skinned in the same production run. The defects may be corrected requiring additional labor, time, and cost, or the production run may have to be scrapped if the defects are not repairable causing lost production and manufacturing inefficiencies.
[0007] The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form any part of the prior art nor what the prior art may suggest to a person of ordinary skill in the art.
SUMMARY
[0008] Exemplary embodiments of the present disclosure provide a system to manufacture skinned honeycomb bodies.
[0009] Exemplary embodiments of the present disclosure also provide a method of manufacturing skinned honeycomb bodies.
[0010] Additional features of the disclosure will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the disclosure.
[0011] An exemplary embodiment discloses an in situ inspection system to inspect a honeycomb body skin in a honeycomb body skinning system for at least one defect. The inspection system includes a part conveying unit that moves a honeycomb body comprising the skin disposed thereon in an axial direction, an inspection unit, and a controller. The inspection unit includes a line illuminator configured to generate a line illumination on the skin perpendicular to the axial direction, and a detector configured to detect the line illumination scattered from the skin and generate a signal based on the detected line illumination. The controller is configured to receive the signal generated by the detector, compare the received signal to a previously stored defect free signal in real-time, and control at least one skinning process parameter based on the comparison.
[0012] An exemplary embodiment also discloses a method of manufacturing skinned honeycomb bodies. The method includes conveying a honeycomb body comprising a skin disposed thereon in an axial direction, in situ inspecting the skin, comparing a signal to a previously stored defect free signal in real-time, and controlling at least one skinning process parameter based on the comparing. In the method, the in situ inspecting the skin includes illuminating a line of the skin perpendicular to the axial direction, detecting the illuminated line scattered from the skin, and generating the signal based on the detecting.
[0013] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the disclosure.
BRIEF DESCRIPTION OF THE FIGURES
[0014] The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the disclosure, and together with the description serve to explain the principles of the disclosure.
[0015] FIG. 1 shows a schematic of a system to manufacture skinned honeycomb bodies according to exemplary embodiments of the disclosure.
[0016] FIG. 2 shows a schematic top view of a projection of four line lasers located 90 degrees apart to cover an outer surface cross section perpendicular to a longitudinal axis of a skinned honeycomb body according to exemplary embodiments of the disclosure.
[0017] FIG. 3 shows a perspective side view of a honeycomb structure comprising a skin being axially applied in a unipipe and passing through an inspection laser line as the honeycomb body exits the unipipe according to these exemplary embodiments of the disclosure.
[0018] FIG. 4 shows a perspective side view of a honeycomb structure comprising a skin being axially applied in a unipipe and passing through an inspection laser line as the honeycomb body exits the unipipe according to these exemplary embodiments of the disclosure.
[0019] FIG. 5 presents data output of laser detectors in an Example embodiment illustrating detection of a pock according to exemplary embodiments of the disclosure.
[0020] FIG. 6 presents data output of laser detectors in an Example embodiment illustrating detection of two skin cement bulges (fast flow) according to exemplary embodiments of the disclosure.
[0021] FIG. 7 shows a schematic control architecture in which skin inspection signal measurement can be utilized in a feedback control scheme to adjust skinning process parameters to reduce or eliminate anomalies, defects, non-uniformities, and the like according to exemplary embodiments of the disclosure.
[0022] FIG. 8 is a process diagram illustrating a method of utilizing data from a honeycomb body skin inspection unit to control skinning process parameters to reduce or eliminate anomalies, defects, non-uniformities, and the like in the honeycomb body skinning process according to exemplary embodiments of the disclosure.
DETAILED DESCRIPTION
[0023] The disclosure is described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the disclosure are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough, and will fully convey the scope of the disclosure to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity.
[0024] It will be understood that when an element or layer is referred to as being “on”, “connected to”, or “adjacent to” another element or layer, it can be directly on, directly connected to, or directly adjacent to the other element or layer, or intervening elements or layers may be present. In contrast, when an element or layer is referred to as being “directly on”, “directly connected to”, or “directly adjacent to” another element or layer, there are no intervening elements or layers present. Like reference numerals in the drawings denote like elements. It will be understood that for the purposes of this disclosure, “at least one of X, Y, and Z” can be construed as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XYY, YZ, ZZ).
[0025] In these exemplary embodiments, the disclosed article, and the disclosed method of making the article provide one or more advantageous features or aspects, including for example as discussed below. Features or aspects recited in any of the claims are generally applicable to all facets of the disclosure. Any recited single or multiple feature or aspect in any one claim can be combined or permuted with any other recited feature or aspect in any other claim or claims.
[0026] While terms such as, top, bottom, side, upper, lower, vertical, and horizontal are used, the disclosure is not so limited to these exemplary embodiments. Instead, spatially relative terms, such as “top”, “bottom”, “horizontal”, “vertical”, “side”, “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
[0027] “Include,” “includes,” or like terms means encompassing but not limited to, that is, inclusive and not exclusive.
[0028] “About” modifying, for example, the quantity of an ingredient in a composition, concentrations, volumes, process temperature, process time, yields, flow rates, pressures, viscosities, and like values, and ranges thereof, employed in describing the embodiments of the disclosure, refers to variation in the numerical quantity that can occur, for example: through typical measuring and handling procedures used for preparing materials, compositions, composites, concentrates, or use formulations; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of starting materials or ingredients used to carry out the methods; and like considerations. The term “about” also encompasses amounts that differ due to aging of a composition or formulation with a particular initial concentration or mixture, and amounts that differ due to mixing or processing a composition or formulation with a particular initial concentration or mixture.
[0029] The indefinite article “a” or “an” and its corresponding definite article “the” as used herein means at least one, or one or more, unless specified otherwise.
[0030] Abbreviations, which are well known to one of ordinary skill in the art, may be used (e.g., “h” or “hr” for hour or hours, “g” or “gm” for gram(s), “mL” for milliliters, and “RT” for room temperature, “nm” for nanometers, and like abbreviations).
[0031] Specific values disclosed for components, ingredients, additives, times, temperatures, pressures, and like aspects, and ranges thereof, are for illustration only; they do not exclude other defined values or other values within defined ranges. The apparatus, and methods of the disclosure can include any value or any combination of the values, specific values, and more specific values described herein.
[0032] As used herein, a green material is an unfired material comprising a mixture of inorganic and/or organic materials. The green material may include various inorganic filler materials, inorganic and/or organic binder materials, and liquid vehicle. The green material may be referred to herein as “wet” prior to drying. The green material may be dried to remove fluid content (e.g. water). Drying is often accomplished by allowing a part to sit exposed to the ambient atmosphere overnight, however, hot air, forced air, microwave, radio frequency (RF) or infrared radiation (IR) may be used to augment drying. The drying may be accomplished in humidity controlled air. Green material may include cold-set cements. The dried green material may be fired to form a porous or non-porous ceramic article.
[0033] As used herein, a “super addition” refers to a weight percent of a component, such as, for example, an organic binder, liquid vehicle, additive or pore former, based upon and relative to 100 weight percent of the inorganic components of the mixture.
[0034] Substrate and filter articles are used in gasoline and diesel, light duty and heavy duty vehicles for after treatment emission control, and which control satisfies environmental regulations. One of the steps in the production of these substrates and filters is the application of a cement-based skin or outer wall on the outer peripheral axial surface of the substrates and filters.
[0035] The skin on a part, such as a porous ceramic filter article, is the interface between the part and the surroundings. The skin serves several functions, for example, the skin adds to the aesthetics of the part and is valued by customers as an indicator of quality, protects the part's functional filter portion from structural degradation such as chipping damage, and other hazards surrounding the part, in manufacture and use, such as in handling and transport of the part, and adds to the isostatic strength of the part, which is a significant performance metric for modern parts.
[0036] FIG. 1 is a schematic diagram of an axial skinning system having an inline skin quality inspection and control unit according to exemplary embodiments of the disclosure.
[0037] FIG. 1 shows a honeycomb structure 100 to be skinned. The honeycomb structure 100 includes a plurality of intersecting walls 102 that form mutually adjoining cell channels 104 extending axially between opposing end faces 106 , 108 . The honeycomb structure 100 may be formed of a single monolith or formed of segments cemented together to form a monolith. The honeycomb structure 100 or part can optionally be first contoured or shaped, and then placed on a part handling unit 110 . For ease of description, the received porous ceramic, such as honeycomb structure 100 , will be referred to as an un-skinned part. The ceramic part received 100 may be un-skinned, contoured, include a base skin to be over-skinned, and the like. Contoured refers to a part shaped to particular dimensions and tolerances, for example, by grinding, machining, core drilling, cutting, or the like.
[0038] The un-skinned part 100 cell density can be between about 100 and 900 cells per square inch (cpsi). Typical cell wall thicknesses can range from about 0.025 mm to about 1.5 mm (about 1 to 60 mil). For example, honeycomb structure 100 geometries may be 400 cpsi with a wall thickness of about 8 mil (400/8) or with a wall thickness of about 6 mil (400/6). Other geometries include, for example, 100/17, 200/12, 200/19, 270/19, 600/4, 400/4, 600/3, and 900/2. As used herein, honeycomb is intended to include a generally honeycomb structure but is not strictly limited to a square structure. For example, hexagonal, octagonal, triangular, rectangular or any other suitable cell shape may be used. Also, while the cross section of the cellular un-skinned part 100 is depicted as circular, it is not so limited, for example, the cross section can be elliptical, square, rectangular, or other desired shape.
[0039] The part handling unit 110 can move the un-skinned part 100 in the axial direction as indicated by arrow 112 into a tube (unipipe) or skinning chamber 114 having a diameter that is slightly larger than the part. Unipipe 114 refers to a central structure of an axial skinning apparatus 116 that is adapted to receive a porous ceramic, such as the honeycomb structure 100 and further adapted to receive flowable cement 118 from a cement source (not shown) through a manifold 120 and to deliver the cement 118 to the surface of the ceramic part within the unipipe 112 to produce the skinned part 122 . The skinning direction is indicated by arrow 124 .
[0040] Honeycomb structure 128 is shown partially skinned in FIG. 1 as it moves through the unipipe 114 . Part handling unit 110 and part lifting unit 132 can provide a motive force to move the part 128 through the unipipe 112 . Honeycomb body 122 is shown exiting the unipipe 114 comprising a uniform layer of cement 118 forming a wet skin 136 on the outer periphery of the honeycomb structure. For ease of description, the skinned porous ceramic, such as honeycomb body 122 , will be referred to as a part.
[0041] Skin material disclosed herein can include those that set at a temperature of less than 200° C., such as a temperature of less than 100° C., and further such as a temperature of less than 50° C., including cement material that can be used in skinning processes employing “cold set” skins. In cold set skinning, only drying of the skinning mixture is required to form a seal of the channel walls of the honeycombs. When a cold set skinning process is employed, heating of the skinned honeycombs to temperatures in the 35-110° C. range can be useful to accelerate drying. In some cold set skinning processes, it is anticipated that final skin consolidation, including the removal of residual temporary binder bi-products such as the sheet 130 and strengthening of the seals, can occur in the course of subsequent processing steps (e.g., in the course of catalyzation or canning) or during first use (e.g., in an exhaust system).
[0042] For example, exemplary compositions in which cold set skinning may be employed include those comprising a refractory filler that comprises at least one inorganic powder, such as at least one of aluminum titanate, cordierite, fused silica, mullite, and alumina, the inorganic powder having a bimodal or mono sized median particle size (D 50 ) of from 15 to 50 microns, such as from 30 to 40 microns for mono sized and additionally a median particle size in a range from about 150 microns to about 300 microns, such as from about 150 microns to about 250 microns for the second particle size in bimodal size compositions, and a gelled inorganic binder, such as gelled colloidal silica. At least one gelling agent, such as at least one of hydrochloric acid, sulfuric acid, nitric acid, citric acid, and acetic acid, ammonium hydroxide, sodium hydroxide, and triethanol amine (hereinafter “TEA”) may be added either before (e.g., as a pre-mix with the gelled inorganic binder) or during batching in order to gel the inorganic binder. Alternatively a non-gelled composition may be used. Such compositions can provide skins that set in a porous ceramic honeycomb body (and be thereby permanently sealed to the channel walls) at a temperature of less than 200° C., such as less than 100° C., and further such as less than 50° C., including about 25° C. Further non-limiting exemplary embodiments of cement compositions used for skinning are discussed below.
[0043] Skin compositions are described in U.S. Provisional Patent Application No. 61/602,883 and U.S. patent application Ser. No. 13/302,262, the contents of which are incorporated herein by reference in their entirety. According to exemplary embodiments the skin composition may be a single glass powder composition including a cement comprising a glass powder as a low thermal expansion filler material, a binder and a solvent or vehicle for carrying the solid constituents of the glass-based cement. The glass of the glass powder filler material may be an amorphous fused silica (SiO 2 ), ground cordierite, AT grog, or silica soot. The glass powder filler material can have a median particle size (D50) between 10 and 20 μm, with a minimum particle size between 7 μm and 75 μm and a maximum particle size between 50 μm and 70 μm. Particle size determined as a mass-based equivalent spherical diameter. The glass powder filler material may comprise, for example, from 60-80 wt. % of the total inorganic components of the cement. Suitable silica powder filler materials are available, for example, under the trade name Teco-Sil, available from CE Minerals of Tennessee Electro Minerals Incorporated, Tennessee, USA. All particle size measurements herein were made with a Microtrac Inc. particle size analyzer, unless otherwise indicated.
[0044] According to exemplary embodiments the skin composition may include an amorphous glass-based cement, the cement formed from a dual glass powder composition comprising a first (fine) glass powder as a low thermal expansion filler material, a second (coarse) glass powder as a low thermal expansion filler material, a binder and a solvent or vehicle for carrying the solid constituents of the glass-based cement. The glasses of both the first glass powder filler material and the second glass powder filler material may be amorphous fused silica having particle sizes greater than about 1 μm. The distribution of glass powder filler material particle size can be multimodal in that a distribution of the glass powder filler material with particle sizes greater than about 1 μm exhibits multiple modes (local maximums) of particle sizes. In one embodiment, the amorphous glass-based cement comprises a bimodal particle size distribution of amorphous glass particles with a particle size greater than about 1 μm. The glass based cement may include a first glass powder filler material wherein a median (D50) particle size of the first glass powder filler material can be in a range from about 10 to about 50 μm, from about 15 μm to about 50 μm, from about 20 μm to about 45 μm or from about 30 μm to about 45 μm, with a D10 in a range from about 1 μm to about 10 μm and D90 in a range from about 25 μm to about 125 μm. A median (D50) particle size of the second glass powder filler material can be in a range from about 150 μm to about 300 μm, in a range from about 150 μm to about 250 μm, in a range from about 170 μm to about 230 μm, in a range from about 180 μm to about 220 μm, with D10 in a range from about 100 μm to about 150 μm, and D90 in a range from about 250 μm to about 350 μm. Particle sizes are determined as a mass-based equivalent spherical diameter. As used herein, the term D50 represents the median of the distribution of particle sizes, D10 represents the particle size in microns for which 10% of the distribution are smaller than the particle size, and D90 represents the particle size in microns for which 90% of the distribution are smaller than the particle size. The dual glass based cement may contain, for example, an amount of the first glass powder filler material in a range from about 20 to about 60 wt. % of the total weight of the inorganic solid components of the cement, in a range from about 25 wt. % to about 50 wt. %, in a range from about 25 wt. % to about 40 wt. %, or in a range from about 25 wt. % to about 35 wt. %. The glass based cement may contain, for example, an amount of the second glass powder filler material in a range from about 10 wt. % to about 40 wt. % of the total weight of the inorganic solid components of the cement, in a range from about 15 wt. % to about 40 wt. %, in a range from about 20 wt. % to about 35 wt. %.
[0045] In one exemplary embodiment, D50 of the first glass powder filler material may be in a range from about 34 μm to about 40 μm, and a median particle size of the second glass powder filler material is in a range from about 190 μm to about 280 μm. In one example, the first glass powder filler material has a D10 of about 6.0 μm, a D50 of about 34.9 μm and a D90 of about 99 μm. In another example, the first glass powder filler material has a D10 of about 6.7 μm, a D50 of about 39.8 μm, and a D90 of about 110.9 μm. In still another example, the first glass powder has a D10 of about 2.7 μm, a D50 of about 13.8 μm and a D90 of about 37.8 μm, and as yet another example, the first glass powder filler material has a D10 of about 2.8 μm, a D50 of about 17.2 μm and a D90 of about 47.9 μm.
[0046] The ratio of the second glass powder filler material to the first glass powder filler material may be in a range from about 1:4 to about 1:1, such as about 1:3.5 to about 1:1, from about 1:3 to about 1:1, from about 1:2.5 to about 1:1, from about 1.2 to about 1:1 or from about 1:1.5 to about 1:1. In an exemplary embodiment, the ratio of the second glass powder filler material to the first glass powder filler material is 1:1.
[0047] To provide the cement compositions of the present disclosure, the inorganic powders comprising any of the above inorganic powders and any optional inorganic additive components can be mixed together with a suitable organic and/or inorganic binder material. The organic binder material may comprise one or more organic materials, such as a cellulose ether, methylcellulose, ethylcellulose, polyvinyl alcohol, polyethylene oxide and the like, or in some embodiments a gum-like material such as Actigum®, xanthan gum or latex. For example, A4 Methocel is a suitable organic binder. Methocel A4 is a water-soluble methyl cellulose polymer binder available from Dow Chemical. A suitable inorganic binder may comprise colloidal silica or alumina comprising nanometer-scale silica or alumina particles suspended in a suitable liquid, such as water. The inorganic binder material can be present in the cement composition in an amount less than about 10% of the total weight of inorganic solids present in the cement, and in some exemplary embodiments inorganic binders are present in an amount equal to or less than about 5 wt. %, and in certain other exemplary embodiments in a range from about 2 wt. % to about 4 wt. % taking into account the fluid portion of the organic binder (wherein the weight contribution of the fluid portion is removed). A suitable colloidal silica binder material is Ludox HS40 produced by W.R. Grace. Typical colloidal binder materials may comprise approximately 40% by weight solid material as a suspension in a deionized water vehicle.
[0048] In some exemplary embodiments, the single and dual glass powder cements described supra may also include an inorganic fibrous reinforcing material. For example, aluminosilicate fibers may be added to the cement mixture to strengthen the honeycomb structure after application of the skin. For example, the cement may include an inorganic fibrous material from about 25 to about 50 wt. % of the total weight of the inorganic solid components of the cement, from about 30 to about 50 wt. %, and in some embodiments from about 35 to about 45 wt. % of the total weight of the inorganic solid components of the cement. In certain other embodiments, fibrous inorganic reinforcing materials may be present in an amount from about 36 wt. % to about 43 wt. % as a percentage of the total weight of the inorganic solids of the cement composition. A suitable inorganic fibrous reinforcing material is Fiberfrax QF 180, available from Unifrax, however, any high aspect ratio refractory particulate could be used.
[0049] Typically, the liquid vehicle or solvent for providing a flowable or paste-like consistency has included water, such as deionized (DI) water, although other materials may be used. The liquid vehicle content may be present as a super addition in an amount equal to or less than about 30 wt. % of the inorganic components of the cement mixture, can be in a range from about 10 wt. % to about 25 wt. % of the inorganic components of the cement mixture. However, the liquid vehicle is typically adjusted to obtain a viscosity suitable to make the cement easy to apply.
[0050] In some embodiments the cement may optionally further contain organic modifiers, such as adhesion promoters for enhancing adhesion between the cement and the honeycomb body. For example, Michem 4983 has been found suitable for this purpose.
[0051] In certain exemplary embodiments, the cement mixture sets at a temperature of less than 1000° C., such as a temperature of less than 800° C., and further such as a temperature of less than 600° C., and yet further such as a temperature of less than 400° C., and still yet further such as a temperature of less than 200° C. In certain exemplary embodiments, the cement mixture is capable of setting at room temperature (i.e., at about 23° C.).
[0052] Cement compositions described herein can exhibit viscosities well suited for forming an external skin over a honeycomb core. For example, compositions according to the embodiments herein can have an infinite shear viscosity equal to or less than about 12 Pascal-seconds (Pa·s.), equal to or less than about 5 Pa·s., or equal to or less than about 4 Pa·s. For a shear rate of 10 s −1 , the shear viscosity may, for example, be equal to or less than about 400 Pa·s, equal to or less than about 350 Pa·s or less than or equal to about 300 Pa·s. Viscosity was measured using a parallel plate viscometer.
[0053] Calcining of cement compositions disclosed herein can be conducted in a box furnace with a linear ramp to 600° C. in 3 hours, followed by a hold for 3 hours at 600° C., then followed by a ramp down to room temperature over a time period of 3 hours. In commercial use, the ceramic article can be wash coated with catalyst followed by a heat treatment to remove organic materials. The ceramic article can also be canned with a mat material that may also require heat treatment to remove organic materials. The calcining process simulates service conditions experienced by the ceramic article.
[0054] The composition of the skin cement is not particularly limited and can include, for example, a skin cement of single glass powder compositions, dual glass powder compositions, single glass powder with fibrous reinforcing material compositions, dual glass powder with fibrous reinforcing material compositions, inorganic filler and crystalline inorganic fibrous material compositions, and dual glass powder and crystalline inorganic fibrous material compositions.
[0055] The inline inspection and control unit 140 can include an inspection unit 144 to inspect skin 136 surface quality. The inspection unit 144 can include a laser unit 148 to emit a light beam 150 and a detection unit 152 such as a charged coupled device (CCD) camera to detect the light beam 150 scattered from the skin 136 . The inspection unit 144 provides a signal 168 based on the detected light beam 150 scattered from the skin 136 surface. The inline inspection and control unit 140 can include a control unit 160 to receive the signal 168 in a receiver module 164 , analyze the signal 168 in a signal analyzer module 172 , and a transmitter module 176 to transmit a control signal 180 to a process controller 184 to control a process of the skinning system 116 in response to the analysis.
[0056] The control unit 160 may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two to implement the methods or algorithms described in connection with the embodiments disclosed herein. A software module may reside in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disk, a removable disk, a compact disc read-only memory (CD-ROM), or any other form of non-transitory storage medium known in the art. An exemplary storage medium is coupled to a processor of the control unit 160 such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an application-specific integrated circuit (ASIC). The ASIC may reside in a computing device or a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a computing device or user terminal.
[0057] While the control unit 160 has been described as separate from the inspection unit 144 , this disclosure is not so limited, that is, the control unit 160 or any of the modules 164 , 172 , 176 thereof may constitute the inspection unit 144 . Further, any unit or module of the in line inspection and control unit 140 may be integral with any other unit or module thereof. For example, the control unit 160 may be integral with the detection unit 152 , and the receiver module 164 , the signal analyzer module 172 , and the transmitter module 176 may be one integral module. Also, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the disclosed subject matter. For example, the control unit 160 may include a storage device, a processing unit, power supply, and the like, and signals 168 , 180 may be transmitted wirelessly, over cables, optical fiber, and the like.
[0058] As the skinned part 122 exits the unipipe 114 in the axial skinning direction 124 it passes through the light beam 150 emitted from the laser 148 . The light beam 150 illuminates a line on the periphery of the part 122 perpendicular to the skinning direction 124 . As the skinned part 122 passes through the light beam 150 emitted from the laser 148 it is inspected by the inspection unit 144 . The inspection unit may include a plurality of lasers 148 and detection units 152 . Accordingly, real-time inspection of parts 122 comprising wet skins 136 can be inspected as they exit the skinning unipipe 114 in these exemplary embodiments of the disclosure.
[0059] While described as the skinned part 122 passing through the light beam 150 in these exemplary embodiments, this disclosure is not so limited. That is, the skinned part 122 may be stationary and the inspection unit 144 may move axially past the skinned part 122 .
[0060] FIG. 2 shows a schematic top view of a projection of four line lasers 148 and detection units 152 located 90 degrees apart to cover an outer surface cross section perpendicular to a longitudinal axis of a skinned honeycomb body 122 according to exemplary embodiments of the disclosure. The maximum and minimum part 122 diameters for the line laser unit 148 and detection unit 152 arrangement illustrated in FIG. 2 are indicated by Ø D8 and Ø D7, respectively. In an exemplary embodiment, D1 may be about 17.7 in (45 cm), D2 may be about 9.45 in (24 cm), D3 may be about 13.8 in (35 cm), D4 may be about 16.8 in (42.7 cm), D5 may be about 40.6 in (103 cm), D6 may be about 20.3 in (51.6 cm), D7 may be about 7 in (17.8 cm), and D8 may be about 13 in (33 cm). The arrangement of line laser units 148 and detection units 152 including number thereof, depends on size and shape of the part 122 periphery and desired circumferential resolution. In exemplary embodiments the circumferential resolution is sufficient to detect 1 mm wide skin defects, for example, the circumferential resolution may be sufficient to detect 700 μm wide skin defects, 500 μm wide defects, 100 μm wide defects, 50 μm wide defects, or even 10 μm wide defects, where the width of the defect is in the circumferential direction, that is, the direction perpendicular to the axial direction regardless of the part 122 shape.
[0061] FIG. 3 shows a perspective side view of a skinned honeycomb structure 122 comprising a skin 136 being axially applied in a unipipe 114 and passing through an inspection laser line 150 as the honeycomb body 122 exits the unipipe 114 according to these exemplary embodiments of the disclosure. The part lifting unit 132 is not shown for convenience. At the bottom center of the skinned part 122 is a pock 188 or small depression in the skin surface that was generated during the skinning process and is about to pass through the laser light beam 150 . A pock 188 is a crater defect in the skin 136 . As used herein, a pit is a pock 188 that penetrates the thickness of the skin 136 from the skin surface to the honeycomb structure 100 beneath the skin 136 .
[0062] FIG. 4 shows a perspective side view of a honeycomb structure 122 comprising a skin 136 being axially applied in a unipipe 114 and passing through an inspection laser line 150 as the honeycomb body 122 exits the unipipe 114 according to these exemplary embodiments of the disclosure. On the right side of the part 122 are two areas where excessive localized pressure or reduced viscosity has produced extra skin cement 118 causing the cement to bulge out from the skin 136 surface referred to herein as “fast flow” defect 192 . When there is a lack of skin cement 118 on a portion of the honeycomb body 122 this is referred to herein as “starvation” defect. That is, a starvation defect can be understood as the opposite of a fast flow defect 192 .
[0063] FIG. 5 presents data output of laser detection units 152 in an Example embodiment illustrating detection of a pock 188 according to exemplary embodiments of the disclosure. In the Example shown in FIG. 5 , four line lasers 148 and detectors 152 were arranged around the part 122 exiting the unipipe 114 as depicted in FIGS. 1 and 2 , as described herein. The field of view of each of the four line lasers 148 was divided into eight sections (areas). During a calibration, a master profile was stored in a memory representing a defect-free part. The master profile comprises a measurement signal from the detected laser of a defect-free part. At specified time intervals or on a continuous basis during the part skinning as the part 122 passes through the inspection laser line 150 , each detected inspection laser line generated an instant measurement signal (real-time data). The instant measurement signal was compared to the master profile. The difference between the master profile and the instant measurement signal for all eight areas of all four lasers 148 was analyzed to find anomalies that indicate defects. The pock 188 defect seen in FIG. 3 shows up as a positive spike 188 ′ in the time series data in FIG. 5 . Depressions in the skin surface are shown as positive deviations in the data while bulges are shown as negative deviations as shown in FIG. 6 , which displays data detecting a fast flow defect.
[0064] FIG. 6 presents data output of the laser detectors 152 in the Example embodiment illustrating detection of a fast flow defect 192 according to these exemplary embodiments of the disclosure. In the Example shown in FIG. 6 , four line lasers 148 and detectors 152 were arranged around the part 122 exiting the unipipe 114 as depicted in FIGS. 1 and 2 , and as described above with reference to FIG. 5 . The difference between the master profile and the instant measurement signal for all eight areas of all four lasers 148 was analyzed to find anomalies that indicate defects. The fast flow defect 192 seen in FIG. 4 comprises bulges of excess cement material in the applied skin and shows up as negative spikes 192 ′ (dips) in the time series data in FIG. 6 . The fast flow bulges 192 are shown as negative deviations 192 ′ in FIG. 6 and are wider peaks 192 ′ in the data than the pit or pock peak 188 ′. Fast flow appears as wider peaks 192 ′ because they tend to last longer in time, for example, the length of a part, and are not localized defects such as pocks.
[0065] FIG. 7 shows a schematic control architecture 700 in which skin inspection signal measurement can be utilized in a feedback control scheme to adjust skinning process parameters to reduce or eliminate anomalies, defects, non-uniformities, and the like according to exemplary embodiments of the disclosure. In FIG. 7 a skinning process controller 184 provides skinning process parameters to the skinning apparatus 116 . Skinning process parameters include such parameters as cement pressure in the manifold 120 and unipipe 114 , the part feed rate through the unipipe 114 , for example, by controlling part handling unit 110 and part lifting unit 132 speeds, the skinning cement 118 chemistry fed into the manifold 120 and unipipe 114 , and disposed on the honeycomb core 128 , for example, amount of water in the cement, amount of air in the cement, or density of the cement skin batch, and the like.
[0066] At skinning process 196 the skinning apparatus 116 applies the process parameters from 184 to skin the honeycomb structure 100 . A skin quality measurement 200 is conducted as the skinned honeycomb body 122 exits the unipipe 114 and passes through inspection unit 144 of the inline inspection and control unit 144 , to inspect skin surface quality as described with reference to FIGS. 1-6 . The skinned part 122 emerges at output 204 . When a defect is detected and identified in the skin quality measurement 200 a control signal 180 provides feedback to the process controller 184 to control a process of the skinning system 100 in response to the skin quality measurement 200 . The feedback to the process controller 184 to control a process of the skinning system 116 in response to the skin quality measurement 200 reduces or eliminates defects in subsequently skinned parts 122 .
[0067] FIG. 8 is a process diagram illustrating a method of utilizing data from a honeycomb body skin inspection unit to control skinning process parameters to reduce or eliminate anomalies, defects, non-uniformities, and the like in the honeycomb body skinning process according to exemplary embodiments of the disclosure. The method can use the axial skinning system 116 having the inline skin quality inspection and control unit 140 according to the exemplary embodiments of the disclosure described with reference to FIGS. 1-7 . In FIG. 8 , operation 804 indicates start of the method. In operation 808 the “on” or “off” state of the inline skin quality inspection and control unit 140 is determined. When the inspection and control unit 140 is in the “off” state operation 812 turns the inspection and control unit 140 to the “on” state. When the inspection and control unit 140 is in the “on” state operation 816 determines whether data from the detection unit 152 has been received by the controller 160 and analyzed by the signal analyzer 172 .
[0068] When the data from the detection unit 152 has not been received and analyzed, operation 820 provides a stand-by state where the inspection and control unit 140 returns to operation 816 . Operation 820 may provide a time period, zero-mean sensor data, and the like before returning the inspection and control unit 140 to operation 816 . When the data from the detection unit 152 has been received and analyzed, operation 824 determines whether a skin defect has been detected in response to the analysis by the signal analyzer 172 .
[0069] When a skin defect has been detected in operation 824 , operation 828 determines which type of defect is detected. When the type of defect detected in operation 828 is a fast flow or starvation 832 , operation 844 applies the system process control rules related to fast flow and starvation defect type. The process controller 184 applies the system process control rules to control a process of the skinning system 116 in response to the analysis.
[0070] According to exemplary embodiments of the disclosure, example system process control rules are shown in Table 1. In these exemplary embodiments, the part conveying unit 110 , 132 may be configured to convey the part 100 , 122 , 128 at axial speeds of about 1 to 100 mm/s. The skinning pressure may be in a range of about 1 psi (6.89×10 3 Pa) to about 6 psi (4.14×10 4 Pa) where the manifold meets the unipipe. A peak deflection from master signal between about −0.6 mm and about −0.8 mm may correspond to a deviation from average skin surface by about 0.6 mm to about 0.8 mm. The average skin surface indicates the topology of a defect free surface. For clarity, when a deflection of less than about −0.8 mm is used herein, the absolute value of the deflection (|Δx|, where Δx is the deflection) is greater than about 0.8 mm. Likewise, when a deflection of greater than about +0.8 mm is used herein, the absolute value of the deflection (|Δx|) is greater than about 0.8 mm.
[0000]
TABLE 1
Condition
Control Action
If 5 consecutive parts have fast
Decrease skinning pressure set point
flow skin defect with peak
by about 1 psi (6.89 × 10 3 Pa) and
deflection from master signal
proceed with skinning for about 2
between about −0.6 mm and
minutes before the next process
about −0.8 mm
parameter adjustment is made
If 2 consecutive parts have fast
Decrease skinning pressure set point
flow skin defect with peak
by about 2 psi (1.38 × 10 4 Pa) and
deflection from master signal
proceed for about 2 minutes before
less than about −0.8 mm
the next process parameter
adjustment is made
If 5 consecutive parts have
Increase skinning pressure set point
starvation skin defect with peak
by about 1 psi (6.89 × 10 3 Pa) and
deflection from master signal
proceed for about 2 minutes before
between about +0.6 mm and
the next process parameter
about +0.8 mm
adjustment is made
If 2 consecutive parts have
Increase skinning pressure set point
starvation skin defect with peak
by about 2 psi (1.38 × 10 4 Pa) and
deflection from master signal
proceed for about 2 minutes before
greater than about +0.8 mm
the next process parameter
adjustment is made
[0071] When the type of defect detected in operation 828 are lines or drag marks on the skin 836 , operation 848 raises a flag to check the part handling unit 110 to part lifting unit 132 top/bottom “handshake” or integrity of the unipipe 114 . An operator may be alerted by the flag in operation 848 to perform the check. That is, a line around the part 122 in a direction perpendicular to the axial direction may indicate a mismatch in alignment between the part handling unit 110 and the part lifting unit 132 alerting an operator to perform alignment of the part handling unit 110 and the part lifting unit 132 . A drag mark may indicate debris in the unipipe 114 alerting an operator to perform cleaning of the unipipe 114 . When the type of defect detected in operation 828 are lines or drag marks on the skin 836 , the process controller 184 may shut down the axial skinning apparatus 116 in an alternative exemplary embodiment.
[0072] When the type of defect detected in operation 828 is a pit/pock 840 operation 852 applies the system process control rules related to pits and pocks defect type. The process controller 184 applies the system process control rules to control a process of the skinning system 100 in response to the analysis. Example system process control rules for pits and pocks are shown in Table 2
[0000]
TABLE 2
Condition
Control Action
If 10 consecutive parts have a
Increase skin cement batch density by
number of pits and pocks
0.1 units and proceed with skinning for
occurrence above a threshold
30 minutes before next adjustment is made
If 5 consecutive parts have a
Increase skin cement batch density by
number of pits and pocks
0.2 units and proceed with skinning for
occurrence above 3X the
30 minutes before next adjustment is made
threshold
[0073] Accordingly, these exemplary embodiments of the disclosure involve hardware and control algorithms to determine the location and size of micron- to millimeter-size defects introduced during an axial skinning process as well as the control algorithm to minimize or eliminate these defects in an automated fashion. The defect detection process can begin with projecting line lasers 148 onto the outside surface of a part 122 where the laser lines 150 are perpendicular to the axis of motion 112 of the axial skinner 116 . The lasers 148 can be situated at the exit of the skinning unipipe 114 where the part has had skin applied. The laser lines 150 can be measured by a camera 152 and optical filter using triangulation to detect any curvature or defects in the skin surface (laser profilometer). For example, large aspect ratio laser line scanners may be selected and combined such that four are disposed at 90 degree increments to produce complete or nearly complete coverage of the outside of a largest part 122 . Complete coverage of the largest part 122 may be accomplished with an additional scanner 148 , 152 if necessary.
[0074] The scan rate of the laser profilometer may be greater than about 1 kHz and thus nearly continuous measurement of the outside surface of the skinned parts is possible in these exemplary embodiments where skin speeds may be in the 5-10 mm/s range. The laser profilometers may be rigidly mounted at a distance needed to cover a range of products of interest, for example about 7 inch (17.78 cm) to about 13 inch (33.02 cm) diameter round cylindrical parts. After the lasers 148 are mounted an ideal surface shape can be captured, one that would indicate a perfect part (defect-free). This profile can be captured and stored in a storage device as the master profile and used to compare against each successive measured profile. Each real-time measurement of the skinned part 122 has the master profile subtracted from it and then the length of each laser line is divided into eight sections. Combining the data from four lasers produces 32 such sections covering the entire part. The analyzer 172 then searches across each of these subsections and calculates the largest deviation in the radial direction from the current measurement and the master profile and reports this value at the sampling rate of the system, for example, at 1 kHz. Thus 32 measurements representing the maximum radial defect measurement around the skinned part can be reported to the controller 160 to be stored in a data archive system and used for active (real-time) control of the skinning process.
[0075] The analyzer 172 can be configured to receive the signal from the profilometer at greater than or equal to a frequency while the part conveying unit 110 , 132 can be configured to convey the part 122 at an axial speed such that successive scans and transmissions are spaced apart by no more than 1 mm in the axial direction. For example, the laser profilometer can be configured to scan the illuminated line 150 and transmit the signal 168 to the controller 160 at greater than or equal to a frequency and the part conveying unit 110 , 132 can be configured to convey the part 122 at an axial speed such that successive scans and transmissions are spaced apart by about 1 mm to about 50 μm in the axial direction 112 . For example, the frequency can be in a range between about 20 Hz and about 2 kHz and the part conveying unit 110 , 132 can convey the part at an axial speed in a range between 2 mm/s and 100 mm/s. In these exemplary embodiments the axial resolution is sufficient to detect 1 mm long skin defects, for example, the axial resolution may be sufficient to detect 700 μm long skin defects, 500 μm long defects, 100 μm long defects, 50 μm long defects, or even 10 μm long defects, where the length of the defect is in the axial direction.
[0076] The controls architecture for the axial skinning process can respond to a quality metric to adjust critical system parameters like manifold pressure, skin speed, and skin cement batch chemistry. The inspection method according to these exemplary embodiments allows the skin process controller 184 to make adjustments to these parameters to maintain good skin quality or reduce length of upsets thereby reducing waste and cost in the process.
[0077] Statistical process control (SPC) principles can be applied to reduce defects and maintain good skin quality according to these exemplary embodiments of the disclosure. Each family of skin defects can be managed separately as the root cause of the defects may be different. Depending on the type of skin defects occurring, a particular control strategy path can be chosen. The controlled process parameter (control knob) to affect a particular skin defect may also be different. For example, if “fast flow” or “starvation” type of skin defect is occurring, then the control knob can be the skinning pressure alone, the skinning velocity alone, or a combination of skinning pressure and skinning velocity. Herein, skinning velocity refers to the velocity of the part 100 , 122 , 128 through the unipipe 114 . Similarly, if “pocks” and “pits” are being formed on the skin, then the control knob in this case can be the skin cement batch composition, such as skin cement batch density.
[0078] This control method according to exemplary embodiments can be implemented either in a semi-automatic manner or in a fully automatic mode. In the semi-automatic mode, the controller 160 can use the data from the skin inspection system 144 and compute the desired control move to be made and display the move in the control room where the operator can decide whether to make the suggested move or not. In the fully automatic mode, the controller 160 can make the moves automatically.
[0079] Once the skin material 118 has been applied to the honeycomb structure 128 in a manner as described herein, the skin 136 can be optionally dried and/or fired. The optional drying step can comprise first heating the skin 136 in a humidity controlled atmosphere at a temperature and for a period of time sufficient to at least substantially remove any liquid vehicle that may be present in the skin material. As used herein, at least substantially removing any liquid vehicle includes the removal of at least 95%, at least 98%, at least 99%, or even at least 99.9% of the liquid vehicle present in the skin 136 prior to firing. Further, the heating can be provided by any conventionally known method, including for example, hot air drying, RF and/or microwave drying in a humidity controlled atmosphere.
[0080] The optional firing step can include conditions suitable for converting the skin material to a primary crystalline phase ceramic composition include heating the honeycomb with applied skin material 122 to a peak temperature of greater than 800° C., 900° C., and even greater than 1000° C. A ramp rate of about 120° C./hr during heating may be used, followed by a hold at the peak temperature for a temperature of about 3 hours, followed by cooling at about 240° C./hr.
[0081] Some of the functional units described in this specification have been labeled as modules, controllers, and units in order to emphasize their implementation independence. For example, a module, controller or unit, herein after “module,” may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. A module may also be implemented with valves, pistons, gears, connecting members, and springs, or the like.
[0082] Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions, which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.
[0083] A module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices.
[0084] Reference throughout this specification to exemplary embodiments and similar language throughout this specification may, but do not necessarily, refer to the same embodiment. Furthermore, the described features, structures, or characteristics of the subject matter described herein with reference to an exemplary embodiment may be combined in any suitable manner in one or more exemplary embodiments. In the description, numerous specific details are provided, such as examples of controls, structures, algorithms, programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments of the subject matter. One skilled in the relevant art will recognize, however, that the subject matter may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the disclosed subject matter.
[0085] The schematic flow chart diagrams and method schematic diagrams described above are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of representative embodiments. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the methods illustrated in the schematic diagrams. Additionally, the format and symbols employed are provided to explain the logical steps of the schematic diagrams and are understood not to limit the scope of the methods illustrated by the diagrams. Although various arrow types and line types may be employed in the schematic diagrams, they are understood not to limit the scope of the corresponding methods. Indeed, some arrows or other connectors may be used to indicate only the logical flow of a method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of a depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.
[0086] It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the spirit or scope of the disclosure. Thus, it is intended that the appended claims cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents. | An in situ inspection system and method to inspect a honeycomb body skin in a skinning system. The inspection system includes a line illuminator to generate a line illumination on the skin perpendicular to an axial direction of the honeycomb body travel, and a detector to detect the line illumination scattered from the skin and generate a signal based on the detected line illumination. A controller is configured to receive the signal generated by the detector, compare the received signal to a previously stored defect free signal in real-time, and control at least one skinning process parameter based on the comparison. The method includes in situ inspecting the skin and controlling at least one skinning process parameter based on the inspection. In the method, the in situ inspection includes illuminating a line of the skin perpendicular to the axial direction and detecting the illuminated line scattered from the skin. | 2 |
This application is a continuation of application Ser. No. 06/942,197, filed Dec. 16, 1986, now abandoned.
BACKGROUND OF THE INVENTION
The invention pertains to the field of sample preparation systems for automated chemical analysis. More, particularly, the invention relates to the field of systems for processing liquid, solid or slurry samples for analysis by liquid chromatography systems.
In many chemical processing plants or laboratories, there is a need for chemical assays for determining the components and/or proportions of the chemical material being dealt with or made. Often this is done using a liquid chromatography system (hereinafter liquid chromatography will be referred to as LC). To be suitable for analysis by liquid chromatography, the sample or sample solution must be homogenous, dissolved in an appropriate solvent, and of known concentration (if diluted).
The types of samples which must be dealt with are often quite varied, and often the manner of isolating an aliquot of sample to analyze is quite varied. For example, the sample preparation system may be called upon to prepare samples that are non-homogeneous, two phase, liquid/liquid or liquid/solid samples or slurries with entrained gas bubbles or foam. Further, the sample may be solid in either granulated, powder or tablet form. Some samples may be quite viscous while others are quite thin. Some samples may need to be taken from vats or tanks where they are stored or prepared while other samples may need to be taken from a process stream. Some samples are susceptible to pumping into the sample preparation system while other samples are solid or too viscous to pump and must be physically picked up by an operator of the sample preparation system.
Often it is necessary to dilute samples with solvents before pumping them through an LC column. Very precise control of the sample concentration is necessary in this case. To obtain this precise control, there must be some way to isolate a known volume of sample from the rest of the sample and to release it into a known quantity of diluent.
Prior art sample preparation systems have, to date, not been capable of handling all the above noted situations gracefully. Generally, prior art sample preparation systems are capable of handling only one type of sample, and major modifications or use of an entirely different system is needed to handle a different type of sample.
Thus there has arisen a need for a single sample preparation system which can easily and conveniently handle all the different types of samples which may be necessary to analyze.
SUMMARY OF THE INVENTION
In accordance with the teachings of the invention, there is provided a sample preparation system which can handle samples of the liquid, solid or slurry type. The system includes a sample preparation chamber having a removable cup which may be taken to the location of solid or extremely viscous samples and a measured amount of sample may be placed therein. The cup has a sloped bottom with a sump point or region which is lower than all other regions of the bottom. The cup attaches in any known, sealing manner to a cap. Through the cap are a fill/empty pipe through which the cup may be filled by pumping in liquid sample, solvent or diluent. The fill/empty pipe outlet is at or near the lowest point of the bottom, so the cup may also be emptied through this fill/empty pipe.
A solenoid operated or pneumatically operated sample metering valve is also provided with an inlet in the cup to allow a known volume of sample to be isolated from the rest of the sample. A nozzle is provided also whereby the walls of the cup may be washed down by pumping of solvent into the cup through the nozzle which deflects the solvent against the walls of the cup. After all excess sample and solvent has been pumped out of the cup, the isolated aliquot of sample may be released back into the cup, and a known volume of diluent may be pumped in to dilute the sample to the desired concentration.
For non-homogeneous samples or solid samples which must be ground into smaller particles prior to being dissolved, a mixer/grinder is provided. This device includes a drive apparatus for imparting rotational motion to a shaft which is connected to a propeller/grinder which is located in the cup.
For some applications, other mixer such as ultrasonic mixers similar to the one distributed by Sonics and Materials in Danbury, Conn., or a high speed homogenizer similar to the one distributed by Brinkman in Westbury, N.Y. may be substituted. In some applications, use of these alternate mixers would be preferred.
An electrically or pneumatically driven reversible pump mechanism which is capable of accurate, repeatable delivery of user specified volumes of liquid provides the facility to move liquids into and out of the cup and to pump them to the injection port of a system. The pump is coupled through two solenoid operated valves to two manifolds. The inlet and outlet manifolds are merely a collection of valves configured to accomplish a desired task or series of tasks. These tasks may include dilution, extraction, sampling, solid phase extraction, low pressure chromatography and others, and may be connected to a variety of other equipment. These include the LC or other analyzer, the effluent (waste) line, several sources of different solvents, a source of pressure, a source of subatmospheric pressure, a water supply, an electrically or pneumatically driven six way valve for bringing in liquid or slurry sample from a vat or storage tank, the nozzle in the cup and a sample valve in a process stream. The process stream sample valve is also coupled to the effluent line through a two way solenoid operated or pneumatically driven valve.
A control circuit or system is coupled to the solenoid operated valves, the pump, the six way valve, the two way valve, the sample metering valve and the mixer/grinder drive mechanism. The control circuit implements a user interface by which the user may specify the operations to be performed by the system, and the parameters for the process to be performed. The control system then issues the proper control signals to the various elements in the system in the proper sequence to cause the desired sample preparation process to occur.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of the system of the invention,
FIG. 2 is a cross sectional view of one type of sample metering valve of the invention with its piston extended.
FIG. 3 is a cross sectional view of the sample metering valve of FIG. 2 with the piston retracted so as to isolate the sample.
FIG. 4 is a cross sectional view of another type of sample metering valve for handling slurries or other samples with gas bubbles therein which must be compressed.
FIGS. 5 through 8 are views of the sample metering valve of FIG. 4 in various states of its operation of drawing sample liquid, compressing any entrained gas, and determining the final, compressed volume.
FIG. 9 is a diagram of another type of sample metering valve suitable for sampling slurries.
FIG. 10 is a symbolic diagram of a 6 way valve in a first state which may be used to replace the sample metering valve for certain types of samples.
FIG. 11 is a symbolic diagram of the 6 way valve of FIG. 10 in a second state.
FIG. 12 is a diagram of an alternative embodiment of the basic invention where the collection of valves constituting the two manifolds in FIG. 1 are replaced in part by multiport rotary valves.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 there is shown a diagram of the sample preparation system of the invention. The system includes a sample preparation chamber 10 the details of which are given in U.S. patent application "Sample Preparation Chamber With Mixer/Grinder and Sample Aliquot Isolation", Ser. No. 942,198, filed 12-16-86 which is hereby incorporated by reference. For completeness here, a short summary of its structure and operation will be given.
The sample preparation chamber is capable of being used to prepare many different types of samples for chemical assay, especially by liquid chromatography. The sample preparation chamber is comprised of a sloped bottom cup 12 which is lightweight, transparent and disposable for holding the sample liquid or solid. The cup threads or otherwise attaches to a cap 14 which serves to keep liquids in by a liquid seal 16 between the cup flange and the mating cap flange. The detachability of the cup allows the cup to be removed and taken to the location of the sample so that a measured amount of sample may be placed therein for solid samples which cannot be pumped as symbolized by the weighing machine 18. Several elements pass through the cap. These elements include a fill/drain pipe 20 which extends to the lowest point 22 in the sloped bottom 24 of the cup and has a diameter which is large enough to pump viscous liquids through without excessive pressure being required. A second fill pipe 26 also passes through the cap, but does not extend to the bottom of the cup. In the preferred embodiment, the fill pipe 26 is adjustable such that the height of the bottom of the fill pipe from the bottom of the cup 12 may be either manually adjusted or adjusted by any known mechanism acting under the control of the control system 98. This fill pipe may have a smaller inside diameter than the fill/empty pipe 20, and may be used to pump liquid sample, solvents or diluent into the cup, especially less viscous liquid samples.
There is also a nozzle 28 which extends through the cap 14. This nozzle is used to wash down the side walls of the cup 12. The nozzle 28 is a propeller like structure in line with the outlet of a pipe 29. To use this feature, the user pumps solvent or some other liquid through the pipe 29 connected to the nozzle. The fluid flow causes the propeller or nozzle element to spin. This deflects fluid laterally out toward the side walls of the cup 12 thereby washing down the walls.
The sample container also includes a stirring/grinding mechanism 30. This mechanism includes a motor 30 driving a shaft 32 which passes through the cap 14. The shaft 32 is coupled to a propeller 34 or other stirring structure which may or may not be suitable for grinding solid samples. The user may change the structure of the stirrer/grinder propeller 34 to best suit the types of samples the user customarily prepares for assay. For example, high speed homogenizers or ultrasonic probes may be substituted.
A sample metering valve 36 is also provided for allowing the user to isolate a known volume of sample from the rest of the material in the cup. In the particular embodiment shown in FIG. 1, the sample volume is isolated in the portion 38 of the sample metering valve. This known volume may then be released back into the cup 12 after the rest of the sample has been pumped to waste through an effluent line 20. The sample metering valve 36 and the mixer/grinder 30 may both be driven either by an electrical motor or a pneumatic drive mechanism. Those skilled in the art will appreciate an adequate drive mechanism for the mixer/grinder 30. The details of the sample metering valve are given in U.S. patent application "Sample Valve For a Sample Preparation System", filed 12-16-86, Ser. No. 942,201 which is hereby incorporated by reference. For completeness here, a short summary of the different types of sample valves will be given.
The sample metering valve is shown in the extended position in FIG. 2. This valve is a device which can repeatedly and accurately isolate a known volume of sample from a larger volume of sample. The sample metering valve used in the invention includes an open end cylinder 13 in which there is positioned a piston 11 having a T shaped sealing end plug 15. The piston 11 slides back and forth in the cylinder 13 within the confines of 17, 29 and 27 between an extended position and a retracted position. The T shaped sealing end plug 15 is sized so as to form a sealing plug in the open end 19 of the cylinder. A cylindrical recess 21 is formed in the piston 11 up from the sealing plug end 15 and is placed on the piston 11 such that the recess 21 is exposed to the surrounding medium when the piston 11 is in the extended position. This causes the recess 21 to fill up with the material of the surrounding medium when the piston 11 is extended. When the piston 11 is retracted, the material in the recess 21 is isolated.
No O ring seals are used on the piston 11 in the valve of the invention. Instead, a soft material 29 is sandwiched at both ends 31 and 33 between two harder retaining rings 17 and 27. A spring 31 is disposed inside the cylinder concentrically around the piston 11. This spring 31 contacts the ring 27 of relatively harder material at the end of the softer material farthest from the sealing plug 14 on the piston 11. The purpose of the spring 31 is to apply a bias force along the negative y axis to the relatively harder ring to exert pressure on the softer material of the sealing cylinder 29 to cause it to expand against the side wall of the piston 11 thereby forming a better seal. Because there are no gaps between the relatively harder sealing rings 17 and 27 and the relatively softer sealing cylinder 29, and because the intersections between the rings 17 and 27 are not exposed to the surrounding medium when the piston 11 is extended, no dead volume is available to fill with unknown volumes of sample.
Typically, the piston 11 is drive either by a pneumatic system or by stepper motors (not shown).
Another embodiment of a metering sample valve is a syringe type valve shown in FIGS. 4 through 8. This valve is especially useful in dealing with slurries with entrained gas bubbles or foam. These bubbles of gas take up volume in an isolated sample which can lead to inaccuracy in predicting the actual volume of liquid which has been isolated in a metering valve. The syringe tube sample metering valve 11 utilizes a cylinder 37 with a piston 41 therein and a separately movable end plug or valve 39. The end plug 39 is moved to an open position so that the surrounding medium 51 may enter the cylinder 38. During filling of the valve, the piston 41 is drawn by a piston drive mechanism 47 to the piston's retracted position to create more volume inside the cylinder 37 thereby lowering the pressure inside the cylinder and causing the it to fill with sample. After the cylinder sample volume is filled, the valve 39 is closed and the piston 41 is separately moved down toward the valve 39 thereby compressing any gas bubbles entrained in or otherwise trapped in the sample volume of the cylinder 37. During this downward movement of the piston 41, the amount of movement, i.e., the distance the piston 41 moves toward the valve during the compression stroke, is monitored by a sensor (not shown but part of the piston drive mechanism 47). When the piston has moved far enough to satisfy a user defined criteria, such as spill from the valve 39 caused by the the compression pressure slightly exceeding the force with which the valve 39 is held closed by the valve drive mechanism 43, the total movement of the piston 41 is determined. This done by direct measurement, interpolation of sensor output data from the sensor or by reading the motor step number in the case of a stepper motor drive 47 for the piston 41. The total volume of liquid in the syringe valve 11 is calculated by subtracting the volume displaced by the movement of the piston toward the valve 39 during the compression stroke from the total original volume of sample in the cylinder before the beginning of movement of the piston during the compression stroke.
The sample may then be released by causing the valve 39 to unseal the cylinder and either letting the sample flow out of the cylinder 37 or by pushing it out by further movement of the piston 41. With liquid samples, especially very viscous samples, the syringe type embodiment has the added advantage that the process of filling the cylinder sample volume with sample may be speeded up by using the piston to draw up the sample into the cylinder by moving it away from the sealing plug from a position adjacent to the sealing plug at the time the plug is opened.
The preferred embodiment of the sample metering valve for use in slurry and other sample situations where the volume consumed by gas bubbles exists is comprised of three, three way valves coupled to a sample metering pump and a source of pressurization (gas in this example) as shown in FIG. 9. A first three way valve A (basically a Y valve) has its common port 3 coupled to a fill pipe 20 in a sample chamber 54. The number 1 port of valve A is coupled to the number 1 port of another three way valve B. This connection forms a sample chamber 64 between the valve mechanisms of the first and second valves. A and B respectively. The number 2 ports of the two valves A and B are coupled together to form a bypass loop 74. The common port 3 of the number 2 valve is coupled to the common port 3 of a third three way valve C which has one of its ports, port 2, coupled to the sample pump 70 and the other port, port 3, coupled to the source of pressurized gas 76.
The valves A, B and C are operated to couple the sampling pump 70 to the fill tube 20 in the chamber. The sample pump is driven so as to suck sample up through the fill tube 20 into the first valve A and out through the sample chamber 64 until enough sample is drawn to completely fill the sample chamber 64 and excess sample is drawn through the valve B into pipe 66 which excess sample is sufficient in volume to compensate for the effects of compression. The first valve A number 1 port is then closed by turning its valve plate 50 to isolate the sample in the sample chamber 64, and the third valve C is operated to couple the pressurized gas at source pipe 76 into the sample chamber 64 through the B valve so as to compress the gas bubbles in the sample trapped there to a small volume. The second valve B is then operated to trap the compressed sample between the first and second valving mechanisms 50 and 51 in valves A and B respectively. This trapped volume may be a known volume or an unknown volume of high reproducibility depending on the application. The sample pump 70 is then operated in the direction so as to empty the rest of the sample 56 not so trapped through the lines 74 and 66. This empties these lines and the sample chamber and prepares the system to be cleaned out with solvent. The solvent is then pumped in through the same lines to fill the container 54 and rinse excess sample away. The solvent is then pumped to waste. Alternatively, the pump 70 may substitute for the compressed gas source 76, or a pressurized sealed head space 22 may substitute as the sample drive mechanism for the pump 70 in the withdrawal of sample 56 from vessel 54 either through loops 74 or 64. The valves and pump are then operated so as to free the trapped sample in sample chamber 64 and to pump a known quantity of solvent through the lines and to push the trapped sample into the sample chamber in preparation for the next desired sample preparation step.
Referring again to FIG. 1, the rest of the sample preparation system will be described. A key element in the system is the liquid pump 84. This pump is reversible such that it may pump liquid in either direction though the pipes 86 and 88 which are coupled to the pump's input and output ports. The pump 84 must be capable of delivering repeatedly, very accurate volumes of liquid since it will be used to pump in precise volumes of diluent to dilute the known volume of sample released from the sample metering valve. Typically pumps with inlet and outlet check valve structures are not reproducible enough in the deliveries of known volumes because of the dead volume of liquid which inevitably results from the check valve operation. Any type of pump with an unpredictable or not reproducible dead volume associated with its output valve structure will not be satisfactory. Dead volume is the unknown, variable volume of liquid trapped by the output valve mechanism which will be released the next time the valve opens to thereby destroy the accuracy of the volume delivered by the pump. Any type of pump and valve/flow meter combination which can accurately deliver a user defined volume of diluent will be satisfactory. A positive displacement pump which is accurate to within 1% volumetric accuracy and 1% relative standard deviation in dispensement precision will be adequate. One type of pump which works well is a "swash" pump. This type, as is known by those skilled in the art, uses a tilted rotating shaft inside a cylinder. The walls of the cylinder have input and output ports located on opposite sides at different levels such that the rotation of the shaft opens and closes the ports sequentially. The axial displacement of the shaft within the cylinder causes liquid to be drawn in from one port and pumped out the other port. The direction of pumping may be changed by reversing the direction of rotation of the pumping plate. The rotation of the plate is controlled by a stepper motor or other mechanism which can precisely control the position of the plate to maintain the output port closed when pumping is not occurring. Such pumps are a manufactured by Fluid Metering Inc. and are patented in U.S. Pat. Nos. 3,168,872 and 3,257,953 both of which are hereby incorporated by reference. Other types of pumps such as syringe pumps will also suffice to practice the invention, but in high volume applications, these syringe pumps may not be commercially practicable.
Another important criterion regarding the selection of the pump is that the sealing mechanism be reliable for a large number of cycles without failure.
The pump 84 is coupled by a control bus 85 to a control circuit/user interface 98 which provides control signals to cause the pump 84 to pump an amount of liquid defined by the control signal in the direction defined by the control signal. The pump drive mechanism may be any type of mechanism such as pneumatic, or stepper motor which can provide the necessary precision of rotor position and accuracy in delivery volume. The details of the control circuit/user interface are not critical to the invention, and those skilled in the art will appreciate that many different type of control mechanisms may be used to control the pumps and valves in the system to do a plurality of different functions and to prepare a plurality of different types of samples for analysis. For example, a programmed digital computer driving stepper motor interface circuits and interface circuits for solenoid operated valves may be used. Further, the control circuit may be dedicated logic, a state machine or a mechanical or analog electronic computer. The interface to the pump and valves may also be via electrically driven pneumatic or hydraulic valves which send pneumatic or hydraulic signals to the pump and valves in the system to cause them to perform the desired functions in the proper sequence. Further, the control circuit 98 may not be a circuit at all in some embodiments, but instead may be a human operator who does all the calculations and operates the valves in accordance with the sequence of steps necessary to process a particular type of sample.
The pipes 86 and 88 are coupled, respectively, through valves 90 and 92 to manifolds 94 and 96. All valves, like the pump 84, are coupled by control signals to a control circuit/user interface 98. The control signals are not shown in full detail since to do so would unduly complicate the drawing. All valves may be solenoid operated valves, or they may be pneumatically operated or driven by stepper motors. The manner of driving the valves is not critical to the invention. Regardless of the type of drive mechanism, all valves should be such that they may be opened and closed upon receipt of the proper control signal from whatever control mechanism is being used to control the system. For example, these control signals arrive on control buses 100 and 102 for valves 90 and 92, respectively.
The manifolds 94 and 96 are coupled through a plurality of valves to a variety of sources of inputs and to a variety of destinations or devices. For example, valve 102 couples a pressure source 104 to the manifold 94. The other valves and facilities in the system are: valve 106 couples the vacuum source 108 to the manifold 94; valve 110 couples water supply 112 to the manifold 94; valve 114 couples the manifold to a 6 way injection valve and to the fill pipe 26; valve 118 couples the manifold 94 to the nozzle 28; valve 120 couples manifold 94 to an isolation chamber (not shown) in the process stream sample valve 122; valve 124 couples the manifold 96 to a filter 126 and an analyzer 128; valve 130 couples manifold 96 to an input port 132 for a first solvent; valve 134 couples the manifold 96 to an input port 136 for a second type of solvent; valve 138 couples the manifold 96 to an input port 140 for a third type of solvent; valve 142 couples the manifold 96 to an effluent pipe 144 which is coupled to the fill/empty pipe 20 through a three way valve 146. The three way valve 146 has an input port 148 which is coupled through a filter 150 to the isolation chamber of the process stream sample valve 122. The three way valve 146 also has two output ports one of which is the fill/empty pipe 20 and the other of which is the effluent line 144. A control signal on the control bus 150 controls which of the output ports of the valve 146 at any particular time is coupled to the input port 148. Each of the valves coupled to the manifolds 94 and 96 is capable of being controlled by the control circuit/user interface circuit 98 such that a control signal from the user interface may open or close each valve.
THE PROCESSES FOR SAMPLE PREPARATION
Solid and Very Viscous Samples Which Cannot be Pumped
The system described above is capable of preparing in different ways many different types of samples from several different sources for analysis by the analyzer 128. For example, the system provides the facility to convert solid samples to diluted liquids at a known concentration. This process involves the following steps. For tablet or granular samples or viscous liquids which do not readily flow, the cup 12 is removed from the cap 14 and taken to the location of the sample. A user determined quantity of the sample is placed in the cup. This may be done by using the weighing machine 18 to weigh the cup before and after placing the sample therein to determine the mass of the sample which has been placed in the cup. The weighing machine 18 can be used to transmit the weight data directly to the control circuit 98 via the bus 152. The control circuit 98 may then use this information to perform calculations to adjust the dilution factors appropriately, or simply retransmit such information to another device.
The cup is then placed back on the cap 14. If the sample is a tablet, the control circuit 98 turns on the mixer/grinder 30 to grind the tablet into smaller pieces to speed up the process of dissolving it in diluent. For granulated or viscous samples, this step may be eliminated.
Next, the sample must be dissolved to form a solution of the proper viscosity, composition, and concentration for pumping through the LC column 128 or other analyzer. Because the control apparatus 98 knows the weight of the sample in the cup from previous steps and has the desired concentration from the user, a calculation may be performed by the control apparatus or by the human operator (hereafter an automated control apparatus will be assumed, although the processes may be performed manually under the control of a human operator who either physically controls the valves and switches driving force to the pump for times calculated by the operator) to determine how much solvent or diluent to pump into the cup 12 to get the desired concentration. The control/user interface system 98 (hereafter the control system) then sends the proper control signals to switch the proper valves to the proper states to pump the selected solvent or solvents into the cup and sends the proper control signals to turn on the pump 84 and cause it to pump in the proper direction to deliver the calculated amount of solvent into the cup 12. For example, if solvent number 1 is to be used, control signals would be generated to open valve 130 and to open either valve 118 or valve 114 depending upon whether the walls were to washed down or not. The proper control signals to activate the pump 84 would then be generated to cause the pump to pump solvent from the port 132, through the manifold 96 and the pipe 88 through the pump 84 and the pipe 86, through the manifold 94 and out into the cup 12 through either the nozzle 28 or the fill pipe 26. These control signals to the pump are such as to cause the necessary volume of solvent to achieve the desired concentration to be pumped into the cup 12.
After the solvent is pumped in, the mixer/grinder 30 may be turned on to mix the solvent and the powder or solid chunks to dissolve the solids. Of course with granulated or powder samples the above noted step of turning on the mixer/grinder before pumping in the solvent may be eliminated. In such embodiments, the solvent may be pumped in as soon as the cup is attached to the lid, and then the mixer/grinder 30 may be turned on to dissolve the sample.
Once the sample is dissolved, if the proper concentration of solvent is present and the solution is homogeneous, the control system forces a predetermined volume of the diluted sample to be pumped to the LC system. To do this the control system 98 causes valves 124, 102 and 114 to be opened and valve 145 in the effluent line to be closed. The valve 146 is caused to couple the portion 160 of the effluent line to the portion 144 of same and pipe 148 is closed off by the valve 146. The result of all these valve operations is than pressurized gas from the pressure source 104 pressurizes the sample preparation chamber defined by the cup 12 and the cap 14 via the manifold 94 and the fill pipe 26. The seals 16 prevent the pressurized gas from leaking away. The pressure forces the liquified sample in the chamber to enter the portion 160 of the effluent line and pass through the valve 146 to the portion 144 of the effluent line. Because the valve 145 is closed, the sample enters the pipe 162 and passes through the manifold 96 where it passes through the valve 124, pipe 164 and filter 126 and is forced through the liquid chromatography analyzer 128.
The problem with this approach is that it is not known how much liquid has been pumped. Generally it is desirable to pump between 4 to 6 times the volume of the connecting tubings (as a minimum) through the system to flush out the lines and to fill the "loop" in the valve in the LC system 128. It is preferred because of timing considerations to know exactly when the sample loop is filled up so that the timing of examination of the output may be established.
If the proper concentration for the sample was not present after the solvent was pumped in, the sample metering valve may be operated as described above by the control system to take a known volume of sample and isolate it. Then the control system causes the three way valve 146 to couple pipe 160 to pipe 144 and valve 145 to open. Then, the valves 102 and 114 are opened, and the remaining sample is flushed through the effluent line 160 to waste by the pressurized gas. Next, if desired, the walls may be washed down by opening one of valves 130, 134 or 138 and the vales 92, 90 and 118 and activating the pump to pump some user defined or fixed quantity of a solvent or solvents through the nozzle 28 to wash down the walls. The mixer/grinder 30, which may a variable speed motor in the preferred embodiment, may be turned on at a high speed during or after the sprinkling process to create turbulence to more thoroughly clean the walls. After the excess sample and solvent are cleaned off the walls, the waste solvent and sample in the cup 12 may be driven to waste by use of the pressurized gas source 104 as defined above. Thereafter, the control system operates the sample metering valve to release the isolated sample back into the cup 12, and operates the pump 84 to pump a calculated amount of solvent into the cup to achieve the user defined concentration for the diluted sample. The manner of doing these operations is as defined above.
Once the desired sample concentration is reached, and the liquid in the cup is homogeneous, the system is ready to have the diluted sample pumped through the LC system. To do this, the pressurized gas method defined above can be used, but the preferred embodiment of getting the liquid sample out of the sample chamber, regardless of whether it was originally two phase liquid/solid, two phase liquid/liquid, solid or extremely viscous is to pump the diluted sample out using the pump 84. The reason this pumped method is preferred is that the system is less complicated from a timing standpoint. With a known volume system, it is known how many pump strokes are necessary to move liquid from the sample cup 12 to the LC system 128. Thus the time to get the sample to the LC system is known, and the control system can control the LC system based upon this known time. If the pressurized gas method is used, the time it takes the liquid sample to get from the sample cup to the LC system is not known because of the the unknowns of the viscosity of the diluted sample changing from one sample the next, and any tubing or fitting changes may also alter the timing. To control such a system, there would have to be an interrupt generated to the control processor or control system when the LC system 128 received the required amount of sample and is ready to go. A polled system would also work. These timing considerations, although not terribly complicated, are additional functions the control system must perform.
To pump the sample to the LC system 128 using the pump 84, the valves 114, 90, 92 and 124 are opened, and the pump is energized to pump from 4 to 6 times the tubing volume, typically 10 to 30 milliliters of diluted sample, to the fill pipe 26, manifold 94, pipe 86, pipe 88 and manifold 96 and pipe 164 as the pathway. This provides better control of the volume of sample delivery to the LC system so that the control of the LC analysis system 128 needs no interrupt or polling to indicate when the sample has arrived. To perform the above steps however requires that the amount of solvent/diluent pumped into the sample preparation chamber be such as to bring the liquid level of the diluted sample at the final concentration to a level above the end of the fill pipe 26. To avoid such complications, it is preferred to put the end 166 of the fill pipe 26 close to the bottom 168 of the sample preparation chamber. This eliminates the need for tradeoffs regarding the volume of the isolation chamber and the volumes of solvent/diluent to pump in to make sure that at all volumes of samples, the final liquid level after dilution will be above the level of the end 166 of the fill pipe 26. In the preferred embodiment, the level of the bottom 166 of the fill pipe 26 may be manually or automatically adjusted to account for such variations. This provides the extra facility of being able to keep the bottom 166 of the fill pipe off the bottom for samples which have sediment or solid material therein which could plug the fill pipe 26 if they were sucked up into the fill pipe.
Sample Dilution Without The Use of a Sample Metering Valve
The sample preparation process where clean, homogeneous samples are to be analyzed, there is no need for the step of homogenization. In such a situation, a 6 way valve may be used to introduce the sample to the cup 12. This valve may be used to isolate a known volume of sample in a loop between valve ports 182 and 184. FIGS. 10 and 11 illustrate how this can be done using two states of a 6 way valve. In FIG. 10 the 6 way valve is shown in the state in which the sample may be drawn from the sample vat. In this state, port 180 is connected to the sample vat and is also connected to port 182. Port 182 is always coupled to port 184 by an internal or external passageway regardless of the state of the valve. It is this passageway which will be used as the isolation chamber in place of the sample isolation chamber in the sample metering valve. The port 186 is coupled to the port 184 in this first state, and is also coupled to the manifold 94 through the valve 114. While the 6 way valve is in the state shown in FIG. 10, the control system 98 opens the valves 114, 90, 92, 142 and 145 and operates the pump to apply suction to the port 186. This draws sample up from the sample vat and fills the loop between ports 182 and 184 with sample. The pumping need only be long enough that the entire passageway between ports 182 and 184 is filled. Alternatively, the sample loop between ports 182 and 184 while the valve is in the state indicated by FIG. 10 may be filled manually by attaching a syringe filled with sample, or any device capable of forcing flow through the sample loop, to port 180 and forcing sample into the sample loop. Port 186 could then be simply connected to any waste receptacle.
The control system then switches the 6 way valve to the state shown in FIG. 11. In this state, the ports 182 and 184 are coupled, respectively, to ports 188 and 190. The port 190 is coupled to the manifold 94 by an additional solenoid or pneumatically operated valve 192, and the port 188 is coupled to the cup 12 via the fill pipe 26. When the 6 way valve is operated by the control system to put it in the state shown in FIG. 11, the sample that filled the passageway between the ports 182 and 184 is isolated. The control system then opens the valves 192, 90, 92 and one of the solvent valves 130 or 134 or 138 and operates the pump 84 to pump a known volume of solvent into the cup 12. The known volume of solvent is computed based upon the known volume of the passageway between the ports 182 and 184. The isolated sample and the known volume of solvent are then mixed by turning on the mixer/grinder 30. Thereafter, the diluted sample may be transferred to the analyzer 128 in any of the manners described above. In alternative embodiments, the ports 180 and 186 may be connected to a sample line with its own pump to fill up the passageway between the ports 182 and 184. The ports 188 and 190 in these embodiments are coupled, respectively, to the fill pipe 26 and to the manifold 94, and the valve 192 is not needed.
Preparing Samples Taken From a Process Stream
The system according to the teachings of the invention is capable of isolating known volumes of samples from a process stream and preparing same for the analyzer. The valve 122 in FIG. 1 is used for this purpose. Control system 98 implements the process by causing the valve 122 to extract and isolate a known volume of sample flowing in process stream 192. The valve 122 is preferably an ISOLOK™ valve series M$ manufactured by Bristol Engineering of Yorkville, Ill. or equivalent. This valve is similar in operation to the valve shown in FIGS. 2 and 3 except that the there are additional ports in the cylinder of the valve coupled to the pipes 194 and 196. These ports are placed on the cylinder of the ISOLOK valve such that when the piston of the valve is in the retracted position, the isolation chamber of the ISOLOK valve analogous to the chamber 21 in FIGS. 2 and 3 is in a position such that pressurized gas or liquid in the pipe 194 will sweep the isolation chamber clear of sample and drive it into pipe 196 or vice versa.
To sample a process stream then, the valve 122 is operated by the control system 98 to isolate an aliquot of sample from the process stream 192. Then, the valves 92, 90, 120 and one of the solvent valves are opened. In addition, the valve 145 is closed, and the three way valve 146 is operated to couple the pipe 148 to the pipe 160. The pump 84 is then operated to draw a calculated amount of solvent from the solvent source and drive it through the pipe 194, the ISOLOK valve 122 and the pipe 196 to sweep the isolated sample out of the isolation chamber and into the cup 12 through the valve 146 and the effluent line 160. The amount of solvent drawn by the pump 84 is calculated from the desired final concentration and the known volume from the ISOLOK valve. Although the exact volume from the ISOLOK valve will not be known to the same precision as would the volume in the isolation chamber of the sample metering valve because of unknown dead volumes in the sealing rings, the precision is good enough for most applications.
Next, the mixer/grinder 30 is activated to homogenize the sample, and the liquid is then driven to the analyzer 128 for analysis in the manner described above.
Processing Slurry Samples
Slurry and other types of samples sometimes have gas bubbles entrained in the liquids. Gas bubbles may be at least partially drawn off before sample aliquot isolation in the system of FIG. 1 by the application of vacuum to the sample preparation chamber before operating the sample metering valve. The lower than atmospheric pressure causes outgassing of the gas entrained in the slurry or in foam bubbles on top of the liquid. Application of the vacuum is performed by the control system 98 by opening the valves 102 and 114 after the slurry is placed in the cup 12 in any of the processes described above. After the gases are drawn completely or substantially off, the sample metering valve 36 is operated to draw in an aliquot of slurry and to compress it as described above. After compression, a known volume of the compressed slurry is isolated, and the remaining slurry is transferred to waste as described above. The walls of the sample preparation chamber may also be washed down as described above if desired. Finally the sample metering valve 36 is operated to release the isolated sample aliquot, and a known volume of solvent is pumped in as described earlier to arrive at the final concentration (serial dilution is possible in this process as it is in any of the processes described herein). The mixer/grinder 30 is then turned on by the control system 98, and the required amount of the diluted sample is transferred to the analyzer 128 as described above.
The water supply 112 may be used to flush out all the pipes in the system by properly operating the valves, but its principal use is in flushing out the sample preparation chamber.
Referring to FIG. 12 there is shown a diagram of another embodiment of the sample preparation system of the invention. In this embodiment, the sample valve is comprised of the three way valves V1, V2 and V3 which operate in the manner described with respect to FIG. 9. Further, the manifolds 94 and 96 are replaced by rotary valves 1 and 2. All the valves are controlled by a control system (not shown) which causes the valves to operated in the proper sequence as described below. To take a sample in the system of FIG. 12, the cup 12 is filled with sample, and valves V1, V2 and V3 are operated to gate the drain line 200 to waste line 202 through the sample loop and the dead volume. The sample is driven to waste by pressurizing the cup via proper operation of V7 to pressurize the gas reservoir 204 with gas and then to use the gas reservoir pressure to pressurize the cup through the valves V7, V6 and the pressure regulator 206.
After the sample loop has been filled, valves V1 and V2 are operated to isolate the sample loop, and V7, V4 and rotary valve 1 are operated to pressurize lines 206, 208, 210, 212 and 200 to drive remaining sample back into the cup. Then the remaining sample in the cup is driven to waste by changing valve V3 to direct flow through drain line 200 to the waste line 202 and the cup is again pressurized using the gas reservoir 204, valves V7 and V6, pressure regulator 206 and the lines 214 and 216. This forces all the sample out of the cup.
The cup is then rinsed by operating rotary valves 1 and 2 and valves V4 and V5 and pump 220 to pump solvent from reservoir 222 into the sprayer reservoir 224. The sprayer reservoir is then pressurized by operating valves V7, V4, and V5 and rotary valve 1 so that pressurized gas is directed from gas reservoir 204 into the sprayer reservoir. The cup is then washed by operating valve V5 so as to direct the solvent in the sprayer reservoir 224 through the rotary sprayers 226 via line 228. The rotary sprayer directs the pressurized solvent stream around inside the cup to wash down all the internal structures by solvent impact. The cup is then emptied of solvent by pressurizing the cup in the manner described above and operating valves V1, V2 and V3 so that the solvent is directed through pipe 230 and the dead volume out through the waste pipe 202.
The fixed volume of sample trapped in the sample loop is then driven back into the cup by operating the pump 220 and rotary valves 1 and 2 to suck a desired diluent/solvent from a reservoir 222 (or other solvents in other reservoirs coupled to rotary valve 2 could be used) and pump it through pipe 232, valve V4, pipes 208 and 210 and 212, the dead volume, the sample loop and the drain pipe 200. The pump 220 is driven to pump a known volume of the selected solvent into the cup thereby pushing the known volume of sample in front of the pumped solvent into the cup along with a known amount of solvent. Pulse dampeners 240 and 242 remove any pulses from all pumping actions done by the system to minimize or eliminate any cavitation and bubbles from the system. As was the case when the sample was first introduced into the cup, a homogenizer or ultrasonic mixer or any other type of stirrer (not shown) may be used to mix the sample, homogenize it or mix it thoroughly.
Having reduced the sample aliquot to the proper concentration, the system is now ready to be pumped through the chromatography system. This is done by operating valves V1, V2, V3 and V4 and rotary valves 1 and 2 such that a path is established from the drain pipe 200 through the pump 220 and out pipe 244 to the chromatography system for assay. If it is desired to sample from a higher layer, the pipe 246 may be used by properly operating the valves in the system to use pipe 246 as the input path to the pump 220. The pipes in the system which still have sample in them and the cup may be purged with solvent in a manner which will be apparent to those skilled in the art from the above discussion.
Another manner of using the system of FIG. 12 is to put a liquid sample containing a chemical of interest in solution in the cup. The pump and valves may then be operated to pump a known volume of the sample through the liquid chromatography column to concentrate the chemical of interest on the active agent which coats the packing material of the column.
Although the invention has been described in terms of the preferred and alternative embodiments detailed herein, other alternative embodiments may be apparent to those skilled in the art. All such alternative embodiments which appropriate the spirit of the invention are intended to be included within the scope of the claims appended hereto. | There is disclosed herein an automated sample preparation system for chemical assay of samples of materials. The sample preparation system includes a sample preparation chamber which includes a removable cup for taking to the location of solid or very viscous samples. The cup may be attached in sealing relationship to a cap through which extends various utilities such as a mixer/grinder to grind solid samples and mix non-homogeneous samples, a fill pipe to pump in liquid samples, an effluent pipe in the sump of the cup to allow pump of samples and solvents and a nozzle to allow liquids to be sprayed against the walls. A sample metering valve associated with the sample preparation chamber allows a known volume of sample to be isolated so that solvent may be pumped in to dilute the sample to a user defined concentration. A reversible pump is coupled by a pair of manifolds which are themselves coupled by solenoid operated valves to various sources of solvents, pressurized gas, vacuum, water, the sample preparation chamber and the assay system. A control system coordinates the operation of all remotely controllable units in the system to allow the user to customize various preparation processes. | 8 |
BACKGROUND
A wide variety of dog leashes are currently available on the market. These leashes typically have a handle, a rope or chain, and a collar or harness. The most common type of handle is a band or loop made of fabric or leather. Other type of handles include automatic retracting leashes which are more expensive and complex to make. All of these leashes leave room for improvement in areas such as control, comfort and security. For example, when large dogs pull with excessive force on the leash, the dog will become harder to control, the handle may slip out of the holder's hand, and handles, such as the fabric handles, may cause discomfort because they dig into the holder's hand.
Handles attached to a rope in a manner similar to the present invention may have been used in certain sporting activities such as water skiing or kite flying but no one heretofore recognized or suggested such could be used for a leash.
SUMMARY OF THE INVENTION
The present invention relates to an improved leash for walking, running and controlling dogs, cats or even children (all are referred to below as a "dog"). The handle of the leash is designed such that the holder can exert greater control over the dog, and the handle is simple, comfortable, economical and secure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the invention.
FIG. 2 is a top view of the invention.
FIG. 3 is an elevational view from the end of the invention.
FIG. 4 is a view of another embodiment of the invention.
FIG. 5 is a view of the handle held in a hand with a horizontal grip.
FIG. 6 is a view of another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1-5, the improved leash 10 is shown. The leash 10 generally includes a handle 12, a rope or chain 30 and a collar or harness 40.
The handle 12 or grip is cylindrical and is approximately ten to twelve inches long in the axial direction with a diameter of approximately three quarters of an inch. When viewed from the end 14 (FIG. 3), the handle 12 is round. The handle 12 is preferably made from wood or plastic and is one solid piece. A rope, chain, string, cable, etc. 30 is attached to the center 18 (the center is defined as a point or points on the handle 12 which rest in a plane equidistant from both ends 14a and 14b) of the handle 12. To make this attachment, either a hole 16 is made through the center 18 of the handle 12 and the rope 30 can be inserted through the hole 16 and secured, or a hook or eye 20 (FIG. 3) can be anchored to the center 18 of the handle 12 with the rope 30 attached to the hook or eye 20.
A collar or harness 40 is located at the other end of the rope 30. Any type of collar or harness 40 which can be used for holding a dog may be incorporated. For example, the collar or harness 40 may simply comprise a thin strip of material 41 which may have a slip knot 42 for securing the collar or harness 40 around the neck of the dog.
The invention is advantageous because of the combination of features of the invention, including the fact that the handle 12 is somewhat "heavy duty", the rope 30 is attached to the center 18 of the handle 12 and the handle 12 is convenient and ergonomic for grasping by the human hand 50. Some of the advantages achieved by this design include the following.
1. The handle 12 is easy and comfortable to hold and is normally held with a natural horizontal grip as shown in FIG. 5, but can be held with a vertical grip or at any position/angle inbetween;
2. The leash 10 is easy to control. Bigger dogs exert a greater pulling force in which case the greater this advantage becomes. This advantage is attributable to features such as the handle 12 is held between the fingers 52 and the palm (not shown) with the rope 30 attached to the center 18 of the solid handle 12, within the fingers 52 (there is no lever effect as with some leash handles where the rope attaches to a handle at a point away or outside the hand), the handle 12 is easy to steer and psychologically the handle 12 has a sports-like feel;
3. The leash 10 is very economical as it is simple to manufacture and is composed of inexpensive parts;
4. The handle 12 is secure within the hand, even when a dog pulls with an unexpected and large force because such a force will be directed between the fingers 52 at the base or knuckle area 54 of the fingers 52 (where the finger joins the metacarpus);
5. The handle 12 is universal in application;
6. The handle 12 can be used as a club to give the user a sense of security, to discipline a dog or to repel attackers.
An additional advantage relating to the invention relates to a technique or method of use of the invention whereby the length of the rope or leash 30 can be shortened (or lengthened) by twisting the handle 12 to wrap the rope 30 around the handle while the handle can still be used to control the dog.
Referring now to FIG. 6, another embodiment 110 of the invention is shown. In this embodiment, the handle 112 is hollowed out and used as a small compartment or container for keeping things, like cookies, dog treats, dog droppings, etc. The hollow interior space 113 could also be used for the installation of a sound device (not shown) such as a radio or other sound transmitter to entertain the user or to give sound signals to the dog.
The compartment/handle 112 may have a larger diameter than the handle 12 previously discussed. For example, the handle 112 may be 1 and 1/2 inches in diameter or greater. This allows for an interior space 113 which has enough volume to accommodate a plastic bag 121, dog droppings (not shown), a sound device, or a miniature scoop 115. A scoop 115 and/or bag are practical for picking up dog droppings. The scoop 115 could be made of paper like materials such as those used to make paper plates or trays, making the scoop 115 disposable. Therefore, the handle 112 could be sold with a pack of disposable scoops 115 and plastic bags 121. The scoops 115 could be made of other materials such as for example plastic.
The size of the handle 112 can vary as needed to accommodate the size of the material to be stored within the handle 112. The handle 112 may have a first compartment 117a at one end 114a which can be used for storing the plastic bag 121, and a second compartment 117b at the other end 114b which can be used for storing the scoop 115. The ends 114a and b may be closed by any known means such as hinged caps 119a and b.
The plastic bag 121 may be used in the invention as follows. The first end 114a of the handle 112 can be opened or the cap 119a removed. Then the plastic bag 121 is removed from the handle 112 and the user places the plastic bag 121 over their hand to insulate or protect their hand from the dog dropping. The user then picks up the dog dropping with their hand which is covered by the plastic bag 121. The user then takes their other hand and pulls the bag 121 off the hand while turning the bag inside out so that the dropping will now be contained on the inside of the bag as the bag comes off the users hand. The bag 121 can then be wrapped, tied shut or sealed and reinserted into the handle 112 where it can remain stored until the user is ready to take it out and place it in a trash container.
In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited is to be understood as referring to all equivalent elements or steps. The description is intended to cover the invention as broadly as legally possible in whatever form it may be utilized. | The present invention relates to an improved leash for walking, running and controlling dogs, cats or even children (all are referred to below as a "dog"). The handle of the leash is designed such that the holder can exert greater control over the dog, and the handle is simple, comfortable, economical and secure. | 4 |
FIELD OF THE INVENTION
The present invention relates to an apparatus and method for the analysis of body tissue by Electrical Impedance Tomography. It is particularly applicable for detecting or monitoring change in volume of the body tissue. A particular application of the invention is the detection of internal bleeding within a living body, particularly intraperitoneal bleeding. Also disclosed is an electrode belt suitable for bioelectrical use and in particular for detection of internal bleeding.
BACKGROUND ART
Electrical Impedance Tomography (EIT) is an imaging method that seeks to create cross-sectional maps of electrical resistivity or impedance distribution inside the body. This has previously been done using a 16 electrode array fixed to the external perimeter of a body about a transverse plane for example as described in U.S. Pat. No. 4,617,939 (Brown & Barber). The electrical current causes a change in the electrical potential on the surface of the body being examined. The other electrodes of the array are used to measure the electrical potential on the surface of the body and thereby monitor the electric field created by the current pattern. Distortions in the field pattern may be related to changes in the impedance distribution inside the body. As the solution of impedance distribution from surface voltage measurements is generally ill-posed, it has not been effective for producing good static images of body organs. This has limited the adoption of the technique for general use.
The EIT process may be contrasted with other bio-electrical procedures such as bioimpedance spectroscopy. Bioimpedance spectroscopy is a process whereby four electrodes are situated at standard reference points on the body (for example, right and left wrists, right and left ankles). The actual positioning of the electrodes could vary with application. The impedance measurements are made with this group of four. Two electrodes are nominated for current flow and the other two are used for measuring voltages. Impedance is measured as a function of frequency (say, over the range 1 kHz to 1 MHz) and the results may be displayed as an R vs. X (resistance vs. reactance) plot over this range or simply as the modulus |Z| or phase or some version of this. The impedance or R or X or related measure would be considered as a dependent variable of measures such as for example % water or % fat, sex, height, extent of bleeding (these being things that may be given a priori or solved for) in a standardized empirical function and so a given Z would be used to extract a parameter such as the extent of bleeding. The success of the process depends significantly on how good the empirical function is and how ‘standard’ the subject. Use of this procedure to detect intraperitoneal bleeding has had very limited success.
Serious injury to internal organs—for example, as can be suffered during blunt trauma associated with road accidents—is usually indicated by the presence of internal bleeding. It is the rate of the internal bleeding, in addition to the total amount of blood lost, which is indicative of serious injury and relative urgency of treatment. A rate of more than 30 ml per minute is usually an indication that intervention may be necessary. Bleeding is usually monitored by monitoring vital signs such as pulse rate, blood pressure and skin colour. However, this is not always a consistent way to detect serious internal bleeding—particularly among younger trauma victims.
The use of EIT for detecting bleeding was discussed in the paper: “Detection and Quantification of Intraperitoneal Fluid Using Electrical Impedance Tomography” by Rosalind J Sadleir and Richard A Fox, IEEE Transactions on Biomedical Engineering, Vol. 48, No. 4, April 2001, pages 484-491.
While EIT has shown considerable promise for detection of intraperitoneal bleeding and other uses, its use has been limited due to certain problems inherent in the technique as used to date. The problem solved by EIT is inherently non-linear which has limited the usefulness of images reconstructed according to linearized approximations. Additionally, the accuracy of the results is limited due to extraneous variations occurring during the test period. Chief amongst these is the effect of breathing. Impedance measurements are particularly sensitive to the changes in abdominal shape and lung air quantity during the breathing cycle. In addition, the electrodes previously used for obtaining EIT images of the abdomen have typically comprised a belt with 16 electrodes adapted to be positioned all around the perimeter of the abdomen. This can be problematic for practical use on patients, especially those where spinal injury is involved. Such belts have also been susceptible to pick up of electrical noise on voltage inputs.
Throughout this specification, the term “issue” will be taken here to include fluids such as blood and lymphatic fluids as well as other types of tissue.
The above description of the prior art is given to assist the reader form an understanding of the nature of the invention disclosed herein. However, this description is not to be taken as indicating that the disclosure in that prior art in any way forms part of the common general knowledge in the art.
DISCLOSURE OF THE INVENTION
According to a first aspect, the invention resides in an EIT system adapted to detect changes in tissue volume within a body portion, the EIT system comprising a plurality of electrodes adapted in use to extend in a substantially linear orientation across one surface only of the body portion and to be applied in electrical contact with the skin of the body portion, a current source adapted to cyclically apply an electric current between one pair of the electrodes, a voltage measuring means to measure the voltage across each of the other pairs of the electrodes resulting from the current, a data collection system and a data analysis system to analyse data resulting from the voltages that are measured by the voltage measuring means, wherein the analysis system is configured to obtain quantitative information related to amounts and rates of conductive tissue changes occurring in the body, based on an EIT analysis equivalent to that obtained from data derived from electrodes spaced around the full perimeter of the body portion.
According to a preferred feature of the invention, the processing means establishes a model of the body portion under analysis comprising a plurality of elements and wherein a parameter representative of an electric field present in each element resulting from the current is calculated from the voltages that are measured and wherein the values of at least a portion of the parameters that are calculated for the elements are amended to substantially reconstruct values that would be obtained from measurements of voltages around the perimeter of the body portion and wherein the change of value of the parameter in a portion of elements over time is indicative of internal bleeding within the body portion.
According to a preferred feature of the invention, the data analysis system implements a series of steps to reconstruct the parameter values of the elements, the steps comprising:
calculate the difference between a reference data set and a measured data set of the voltages as measured to establish a vector; multiply the data set by a reconstruction matrix to obtain a reconstructed image having a plurality of pixels; integrate the values of the pixels in the reconstructed image to obtain a value of the parameter; apply spatial filtering to correct for non-uniformity of parameter over the image plane monitor change in the value of the parameter over a period of time to provide an indication of change of tissue volume.
According to a preferred feature of the invention, a detected change in tissue volume is representative of internal bleeding.
According to a preferred feature of the invention, the parameter is defined as Resistivity Index calculated in accordance with one of:
R
I
=
∫
Ω
ⅆ
σ
ⅆ
S
or
R
I
=
∑
p
=
1
T
P
ⅆ
σ
ⅆ
A
p
for a two-dimensional array, or
R
I
=
∫
Ω
ⅆ
σ
ⅆ
V
or
R
I
=
∑
p
=
1
T
P
ⅆ
σ
ⅆ
V
p
for a three-dimensional array, where dA p and dV p are the areas or volumes of two or three dimensional image elements respectively.
According to a preferred feature of the invention, the data analysis system further implements the steps of:
using empirical sensitivity calibration to provide an estimate of the parameter in terms of blood volume; dividing the estimated blood volume by time interval between reference and measured data sets to provide an estimate of the rate of bleeding; determining an alarm category depending on the rate of bleeding that has been calculated:
According to a preferred feature of the invention, the data analysis system applies a digital filter to the data to provide temporal filtering of the data to thereby remove or at least minimise the effect of breathing on the EIT analysis.
According to a preferred feature of the invention, the electrodes are provided in a belt adapted to be lain across an anterior surface of the body portion and having a length such that the ends to not extend fully around said body portion, the electrodes being spaced along the length of the belt.
According to a preferred feature of the invention, each electrode comprises a contact face adapted to contact the skin of the body portion wherein the contact face is of elongate form having an elongate axis oriented substantially transverse to the linear spacing of the electrodes.
According to a preferred feature of the invention, the current source, voltage measuring means and data collection system are associated with an on-patient module adapted to be carried by the body having the body portion, wherein the data analysis system is provided by a remote processor and wherein data communication is provided between the on-patient module and the remote processor.
According to a preferred feature of the invention, the data communication is by wireless communication.
According to a preferred feature of the invention, the on-patient data module comprises processing circuitry and a telemetry transceiver that will allow data to be transferred to and from the processor.
According to a preferred feature of the invention, the processing circuitry selects the pair of electrodes to which a current is applied and the pair of electrodes across which voltage is measured at any point in time.
According to a further aspect, the invention resides in a method for detecting changes in tissue volume using an EIT system, the method comprising the steps of:
applying a current between a pair of electrodes spaced at the surface of a body portion; measuring, at predetermined intervals, and at a multiplicity of locations in a plane through the body portion, the voltage between pairs of electrodes at the surface of the body portion resulting from the applied current to provide a set of voltage measurements, wherein the electrodes extend in a substantially linear orientation across one side only of the body portion; determining the changes of the voltage measurement between consecutive sets of voltage measurements; generating a reconstructed image of the body portion; determining the resistivity index of the tissue within the body portion from the reconstructed image; deriving a volume of tissue from the determined resistivity index; determining the rate of change of tissue volume between consecutive sets of voltage measurements.
According to a preferred feature of the invention, the method includes the further step of initiating an alarm where the rate of change of tissue volume is above a predetermined value.
According to a preferred feature of the invention, the resistivity index is calculated by generating a vector indicative of the changes in voltage measurements between consecutive sets of voltage measurements; and multiplying the vector by a reconstruction matrix, the resultant matrix being the reconstructed image.
According to a preferred feature of the invention, the resistivity index is calculated by integrating the pixel values from the reconstructed image.
According to a further aspect the invention resides in an electrode belt adapted for use with an EIT system, the belt comprising a plurality of electrodes spaced along the elongate length of the belt and having contact faces adapted to make electrical connection with the skin of a body portion under examination wherein the belt is adapted to provide engagement of the electrodes on one side only of the body portion.
According to a preferred embodiment, the contact faces are substantially rectangular with a length in the range of 75 mm to 100 mm and a width in the range of 5 to 25 mm.
According to a preferred feature of the invention, the belt is flexible to enable the belt to conform to the profile of the body portion upon which it is placed to facilitate contact of each electrode with the body portion.
According to a preferred embodiment, the body portion is the abdomen and the ends of belt are formed with a curvature to facilitate contact of electrodes in the vicinity of the sides of the abdomen when in use.
According to a preferred embodiment at least some of the electrodes are provided with an adhesive surround to facilitate secure engagement of the electrode with the skin.
According to a further aspect the invention resides in an electrode belt adapted for use in bioelectrical measurements, wherein the belt is of elongate form having at least four electrodes spaced along the elongate length of the belt, the belt comprising a plurality of layers wherein the belt is constructed to provide active shielding.
According to a preferred feature of the invention, the belt comprises a core and shielding components, arranged in a multi-layer structure to provide active shielding.
According to a preferred feature of the invention, one of the outer layers comprises a plurality of apertures spaced along the length of the layers to thereby expose an underlying conducting layer and thereby define a corresponding plurality of electrodes.
According to a preferred feature of the invention, each electrode has a conductive track connecting each electrode with a termination.
According to a preferred feature of the invention, the belt is manufactured by a process similar to that used for printed circuit board manufacture.
According to a preferred feature of the invention, the belt is adapted for use with EIT measurements.
According to a further aspect, the invention resides an apparatus for detecting changes in tissue volume and its rate of change by EIT analysis comprising:
first processing means;
second processing means; and
electrode means adapted to apply a predetermined current between a pair of electrodes spaced at the surface of a body portion, under control of the first and second processing means and also adapted to measure in a plane through the body portion, the voltage between pairs of electrodes at the surface of the body portion resulting from the applied current to provide a set of voltage measurements, wherein the electrodes extend in a substantially linear orientation across one side only of the body portion;
the first processing means being operable to receive the set of measured voltages and to provide the set of voltage measurements to the second processing means, the first processing means being further operable to receive sets of voltage measurements at predetermined intervals and to provide these sets to the second processing means, the second processing means being operable to determine the changes in the voltage measurement between consecutive sets of voltage measurements; to provide a reconstructed image of the body portion; to determine the resistivity index of the tissue from the reconstructed image; to derive a volume of tissue from the determined resistivity index; and to determine the rate of change of tissue volume between consecutive sets of voltage measurements.
Preferably, the first processing means is further operable to measure voltage noise levels.
Preferably, the second processing means is further operable to initiate an alarm where the rate of change of tissue volume is above a predetermined value.
Preferably, the second processing means is operable to determine the resistivity index by calculating a vector indicative of changes in voltage measurements between consecutive sets of voltage measurements; multiplying the vector by a reconstruction matrix, the resultant matrix being the reconstructed image.
Preferably, the resistivity index is generated by integrating over pixels in the reconstructed image.
Preferably, the electrode means comprises a belt including a multiplicity of substantially equidistantly spaced electrodes, whereby current can be applied to any pair of the multiplicity of electrodes, and the voltage measured from one or more pairs of the multiplicity of electrodes.
Preferably, the first processing means is operable to apply current to all pairs of electrodes on the belt, and to take voltage measurements from all possible pairs of electrodes, for each current electrode pair.
Preferably, the second processing means is provided remote from the first processing means.
Preferably, the current is applied to all pairs of electrodes on the belt, and voltage measurements are measured from all possible pairs of electrodes, for each current electrode pair.
Thus, the apparatus and method of the present invention provides a significant number of advantages over known methods. It detects the rate of bleeding, and is particularly suitable for use with young people. It is non-invasive, low cost, and can avoid the need for surgery. It is small, portable and light and easy to use, and so could be used, for example, at the scene of an accident. In addition, it does not necessarily require special skills. It is sensitive, and can be used even for small amounts of fluid.
The belt has the advantage that it does need to be placed all the way around a patient's abdomen, thereby reducing any discomfort to the patient or risk of aggravating an existing injury, and facilitating its use for operators.
The invention will be more fully understood in the light of the following description of several specific embodiments:
BRIEF DESCRIPTION OF THE DRAWINGS
The description is made with reference to the accompanying drawings, of which:
FIG. 1 is a block diagram of the component parts of the apparatus of the present invention;
FIGS. 2A to 2G are plan views of the layers that make up the electrode belt of the apparatus of FIG. 1 ;
FIG. 3 is an enlarged schematic cross-section through an electrode on the belt of FIGS. 2A to 2G illustrating the layered structure; and
FIG. 4 is a schematic block diagram of the components of the on-patient module 2 of FIG. 1 ;
FIG. 5 is a diagrammatic representation of the processing flow of information by the processor; and
FIG. 6 illustrates a 16×16 array for use in representing data measured by the apparatus of FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The embodiments of the invention are directed to an EIT system and method adapted to detect changes within a body. They are particularly suited to detecting internal bleeding within the peritoneum.
As previously mentioned, EIT systems apply a current to a body and measure voltage between electrodes placed on the surface of the body. From these measurements it has been possible to calculate the electric field which is created in a two-dimensional plane or three dimensional volume as a result of the electric current flow. A variation in electric field results from changes in resistivity of the various tissues within the region. From these resistivity changes, it is possible to create an image of changes in organs and tissue present in the region. While this has been done in the past, the quality of the images that have resulted have been quite poor and thus the process has had limited practical imaging application. The inventors have recognised that while intrinsic image quality may be poor, the process may be used to provide a parameter calculated from the output of an EIT imaging system which is subject to change and can be monitored in real-time. Internal bleeding is a particular phenomenon which causes the specified parameter to vary due to the significantly different resistivity of free blood in comparison with that of other tissue in the abdomen. Pooling of blood (or other conductive fluids) create a localised anomalous electrical conductivity which perturbs current flow within the body, and therefore perturb impedance measurements made on the body surface. These perturbations can be measured via the imaging process, to enable calculation of the rate of change, volume and location of the anomalous fluid. In this way the inventors have identified a manner in which EIT can be used to identify and monitor internal bleeding by non-invasive means.
As the most common cause of intraperitoneal bleeding is blunt trauma received in motor vehicle accidents the inventors have been concerned to develop apparatus that may be used for use with such patients who may well be suffering other injuries, including spinal injuries and/or be unconscious. EIT equipment of the prior art is often not suitable for use in such circumstances.
The first embodiment is described with reference to FIGS. 1 to 6 . As shown in FIG. 1 , the first embodiment is an EIT system 1 adapted to detect internal bleeding in the peritoneum and comprises a flexible electrode belt 3 , an on-patient module 2 and a processing means 4 .
As better shown in FIGS. 2A to 2G , the electrode belt 3 is of elongate form having a plurality of electrodes 7 equally spaced along its length. Unlike the belts of the prior art which are adapted to be placed around the perimeter of the abdomen, the belt of the embodiment is arranged to be placed against the anterior surface of a patient's abdomen, so that it runs substantially from one side of the patient's abdomen to the other side. It is thus considerably shorter than conventional electrode belts which have been used for EIT. In typical use, the belt 3 is placed proximate the umbilicus. The belt has some flexibility to enable it to adapt to the contour of the abdomen and hold the contact faces of all electrodes in firm contact with the skin of the abdomen to thereby ensure satisfactory electrical conduction. In use, the contact faces are pre-gelled with an appropriate conductive paste to assist contact with the skin, and contact is further assured by means of adhesive surrounding each electrode face. It can be seen that the belt thus define a substantially linear array of electrodes across the abdomen, as required for EIT analysis. The electrode belt 3 is used to apply a current between a selected pair of the electrodes and to make measurements of voltages between remaining pairs of electrodes.
The contact faces of the electrodes are elongate and preferably of substantially rectangular form. The elongate axes of the contact faces are oriented transversely to the elongate direction of the belt, so that when the belt is applied to the abdomen the contact faces lie substantially parallel to a central axis of the abdomen. Elongate electrodes have been found to produce a more uniform parameter sensitivity in images. Internal bleeding can be present anywhere within a large region of the abdomen, and, in use, the belt 3 is usually applied centrally in the region of the umbilicus. The elongate shape of the contact faces of the electrodes ensures that the electric field applied to the abdomen is relatively uniform over a wide region of the abdomen and that, consequently, the rates estimated and gathered from the abdomen are relatively insensitive to their axial location relative to the electrodes. The length of the contact faces is selected as a compromise to provided extended length while ensuring good contact with the body. Typically, a length in the range of 75 mm to 100 mm has been found to be optimum, although lengths outside these limits will still function. The width is selected to ensure good contact area, while providing adequate spacing between electrodes. Typically, a width in the range of 5 mm to 25 mm has been found to be suitable.
The contact faces are composed of silver/silver chloride or any other suitable electrode material. Each electrode 7 has a conductive track 8 connecting the electrode 7 to an electrical termination 9 .
While the EIT system of the invention can be adapted to function with electrode belts constructed in the manner of the prior art, it is very desirable to minimise electrical noise. Because the measurement of voltages between a pair of electrodes is intrinsically a high impedance measurement, when the voltage signals are processed, they are susceptible to noise. Thus, noise suppression or insulation must be used. In the present embodiment, active shielding is provided in which a coaxial configuration is used by means of the novel construction of the belt. In this way, signals are transmitted from the belt to the on-patient module 2 , with the signal being applied both to the core and to the shield of the coaxial configuration. By doing this, there is no capacitive coupling between the shield and the core, because there is no differential voltage between the core and the shield. A low impedance shield voltage is generated using follower amplifiers in the on-patient module 2 .
The electrode belt of the embodiment is constructed in a manner similar to a flexible printed circuit. In the present embodiment, the coaxial configuration is created using a seven-layer arrangement—as is illustrated in FIGS. 2A to 2G . FIGS. 2A to 2G each show one of the seven layers.
The two outer layers 10 a , 10 b comprise an insulating material and one 10 a includes apertures 12 to allow the electrodes 7 to contact the patient's skin. There is also provided an aperture 11 for a termination 9 .
As mentioned above, each electrode 7 comprises a core and shield arrangement. FIG. 2C illustrates the core layer 10 c . The core layer comprises the electrodes 7 , each electrode having a printed conductive strip 8 , which will be used to connecting the electrode 7 to the coaxial cable 5 . Each conductive strip 8 leads to a termination 9 , which in turn connects to the coaxial cable 5 . The conductive strips 8 are also made from a suitable conductive material such as silver. On either side of the core layer 10 c are insulating layers 10 d and 10 e , which provide a layer of insulation between the core and the shielding. It can be seen from FIGS. 2A to 2G that one insulating layer 10 e provides insulation over the electrodes 7 , while the other layer 10 d does not, thereby allowing the electrodes 7 to protrude through the apertures 12 on the outer layer 10 b . On either outer side of the insulating layers 10 d and 10 e are the shielding layers 10 f and 10 g . These layers 10 f , 10 g include shielding for the electrodes 7 and conducting strips 8 of the core layer 10 c , and are also made of a conductive material such as silver.
The two outer layers 10 a , 10 b are then placed on the outside. The belt 3 is printed using conventional printing techniques, with alternate layers of silver and insulating material. The traces of the different layers have different widths. The shielding layers 10 f , 10 g have the same, and thickest, width and are printed in silver. The insulating layers 10 e , 10 d have a smaller width and are printed in insulating material. The core layer 10 c has the smallest width and is also printed in silver. If the shielding layer 10 f is printed first, then subsequent layers laid down will take on the shape indicated in FIG. 4 , thus forming a complete shielding layer around the core. FIG. 4 shows, as mentioned above, the detail of a single electrode 7 , and illustrates this.
As mentioned above, the core and shielding conductive strips are terminated with a suitable termination 9 including a core portion and a shield portion that can then be coupled to a coaxial cable 5 . The termination 9 comprises sixteen separate terminations—a core and shielding component for each electrode 7 .
In this way, signals can be sent to and from the electrodes 7 from the on-patient module 2 , to carry out the appropriate measurements as will be described in more detail below.
The on-patient module 2 comprises processing circuitry and a telemetry transceiver 21 that will allow data to be transferred to and from the processor 4 . In the embodiment, the data is transmitted by wireless communication to remove the need for a physical connecting cable between the body under test and the processor. Nevertheless, it should be appreciated that a wired connection could be used as an alternative.
The components of the on-patient module 2 are illustrated schematically in FIG. 4 . These components are standard components and are mounted, in a conventional, known manner on a printed circuit board (PCB) (not shown). The on-patient module 2 applies current to a selected pair of adjacent electrodes 7 , and reads voltages from other pairs of adjacent electrodes 7 . Current is supplied via a current multiplexer 13 and a constant current source in response to signals from a direct digital synthesiser (DDS) 14 , and digital signal processor (DSP) 16 . As an example, the DSP 16 can be an Analog Devices ADSP-2181 and the DDS 14 can be an Analog Devices AD9850. The actual current is provided by a current source 23 provided between the DDS 14 and the current multiplexer 13 . A current monitor 15 measures the actual current applied to the electrodes 7 —which may be slightly different to the constant current selected to be applied to the electrodes 7 , due to the source resistance of the body—and transmits the measured value of the current to the DSP 16 , to ensure that the correct current value of the current is communicated to the processor 4 . The DDS 14 controls the frequency of the current signal to be applied to the current multiplexer 13 . In the present invention, the current is usually selected at around 3 mA and 62 kHz, although this can be varied.
When current is applied to a pair of adjacent electrodes, then the resulting voltages between other pairs of electrodes on the electrode belt 3 are measured These voltages are input via a voltage multiplexer 17 to a differential amplifier 18 to provide a voltage difference, dV, which is then input to an analogue to digital converter (ADC) 24 , which then provides a 14-bit data signal to the DSP 16 corresponding to this voltage difference.
Controlling signals and data can be sent to and from the DSP 16 to the remote processor 4 via a serial communications port 20 . As mentioned above, this data is sent using radio telemetry, and a suitable radio telemetry transceiver 21 is provided on the on-patient module 2 . However, it will be understood that other communications means—either wireless of fixed line—could be used. The on-patient module 2 also includes a battery (not shown), which supplies power to the components, as well as to the electrode belt 3 .
The software for the on-patient module 2 resides on an EPROM 22 . Upon reset of the DSP 16 , it boots from the EPROM memory.
The software consists of a main routine and approximately 20 subroutines carrying out various functions. The main routine carries out the initialisation of the various circuit elements on the PCB and then enters an infinite loop waiting for events, to which it responds. Events are initiated by the receipt of characters on the serial port 20 of a UART board coupled to the DSP 16 and memory mapped into the DSP data area. The arrival of particular character strings causes selected activities to be executed within the software subroutines. Several interrupts are enabled for the DSP 16 . A timer interrupt is used to start and stop activities that need to be done in a timely fashion. The transmission and reception of characters on the UART connected to the DSP is also done using interrupts.
Character strings sent to the UART 20 from the processor 4 are used to invoke the following activities:
Test whether the On-Patient Module 2 is on and communicating properly. Select two electrodes on the electrode belt 3 , to which the current is to be supplied. Select electrodes on the electrode belt 3 , from which voltages are to be measured—this is usually all other possible pairs of electrodes on the belt, that is apart from the electrodes to which the current is supplied. Select the gain of the differential amplifier 18 used to amplify the voltage measured on the selected voltage electrodes. Select the frequency for transmission of the signal to the electrodes i.e. that of the current applied to the belt 3 . Four frequencies are available—15625 Hz, 31250 Hz, 62500 Hz and 125000 Hz. The default is 62500 Hz. Carry out a single measurement of current (using the current monitor 15 ), and the voltage using the presently selected current and voltage electrode pairs from the belt electrodes 7 . Carry out a complete measurement of all possible voltage and current readings from all possible current electrode pairs on the electrode belt 3 . In one instantiation, eight current source positions and forty voltage measurements are made in total. Electrode pairs include the two end electrodes between which measurements are taken/current is applied. Stop all measurements, calculations and activities being undertaken. Measure On-Patient Module 12 battery health.
Prior to the initiation of the above functions—by the receipt of a character string by the UART serial port 20 connected to the DSP 16 —the DSP 16 transmits a string back out the serial port 20 to the processor 4 , to verify that the command was received. The DSP 16 carries out all the logic to convert the bit stream arriving at its serial port into meaningful characters. Characters sent through the UART serial port 20 are mapped into the memory of the DSP 16 . The clocking signal of serial port 1 is used to control the triggering of the ADC 24 . The timer interrupt is set up to allow timer interrupts to be used to start and stop data gathering. Interrupts for the reception and transmission of data on the serial port of the UART serial port 20 are enabled. All extraneous serial port interrupts are cleared and nesting of interrupts is disabled. Programmable flag pins are set to be outputs rather than inputs.
The DDS 14 operates in a conventional, known manner.
The current monitor 15 includes a programmable gain amplifier that amplifies the signal to the current monitor 15 . The differential amplifier 19 amplifies either one of the battery signal or the voltage from the selected voltage electrodes. Both amplifiers have their gains set to one of 4 values. The gain of the current monitor PGA may be set to 1, 10, 100 or 1000. In practice it is set to 1000 because the current monitor signal is small. The gain of the other PGA is set to 1 (for battery signal) or 10, 100 or 1000 (for voltage measurement). Two control lines are required for both amplifiers to program one of the four gains. These control lines are connected to programmable flag outputs on the DSP 16 and thus gains are set by the DSP 16 . A programmable switch is used to select what signals are sent to the second PGA above—that is either the voltages from electrodes 7 or battery voltage and subsequently to the ADC 24 .
There are four 8-channel multiplexers on the PCB. Two are in the current multiplexer 13 and two are in the voltage multiplexer 17 . The multiplexers select one of the eight electrodes 7 to be the positive current electrode, and a second to be the negative current electrode i.e. each selects one of the pair of electrodes to which the current is applied; and the positive voltage electrode and the negative voltage electrode i.e. the pair of electrodes between which a voltage measurement is taken. The multiplexers are set by logic levels supplied by two 8-output programmable latches connected to the DSP 16 . One latch is programmed to output the four logic levels (3 inputs to set the channel and 1 to enable) required for each of the 2 multiplexers in the electrode current circuit and the other is likewise programmed to output settings for the voltage multiplexers. The latches reside on the data bus of the DSP 16 and are programmed with a write to the DSP's data bus.
A programmable switch is used to select whether the ADC 24 is supplied with a signal from the current monitor 15 , or via the differential amplifier 18 . This switch is set by a logic level output from a programmable flag on the DSP 16 . Clocking of the ADC 24 is carried out by the clock line from serial port 1 on the DSP 16 . No other use is made of serial port 1 . Clocking of the ADC 24 is undertaken at a rate of 32 times the frequency transmitted through the current electrodes of the electrode belt 3 . The clocking rate is set by writing a counter value into a register on the DSP 16 .
The output of the ADC 24 is wired to the IDMA port on the DSP 16 .
Prior to enabling a voltage or current measurement the IDMA port is set up to start writing into a particular memory location in the DSP's random access memory (RAM), thus storing the measured value at the selected memory location. The DSP's IDMA port increments the pointer to the write location after each analogue to digital conversion.
In one instantiation, 8000 samples of waveforms are recorded. This corresponds to 250 periods of the transmitted waveform with 32 measurements per period. The 14 bits from the ADC 24 are written into the 14 least significant bits of the chosen 16-bit location in the RAM. The second most significant bit is zero. The most significant bit is an overflow test bit from the ADC 24 .
The 8000 samples are then used to provide a measured value for the current and voltage. Thus, after 250 periods are recorded for the required measurement, that measurement is processed and the results transmitted to the processor 4 via the UART serial port 20 . A baseline level for each measurement is calculated. This is done to allow for voltage offsets on amplifiers, the ADC 24 and the electrodes 7 .
In one instantiation, each of the 32 voltages in the period of the current or voltage waveform is estimated by averaging them over the 250 periods. This results in 32 numbers. Once appropriately normalised they are compared with the full averages over 250 periods to derive a standard deviation measure of the validity of signal measurement.
After subtraction of the baseline level, the amplitude of the AC signal from the current monitor or voltage electrodes is calculated by summing the square of the 32 averaged samples.
For calculation of the battery voltage (a DC signal), a simple normalised average of the 8000 samples is calculated.
Data and standard deviations are formatted as 32-bit real floating-point numbers and transmitted out the UART serial port 20 to the processor 4 .
The processing of the data by the processor 4 is represented diagrammatically by FIG. 5 . The processor 4 may take any suitable form such as a handheld computer or personal digital assistant, for example a Hewlett Packard Jornada or iPAQ palm size computer or any serial capable device. In the embodiment, the processor is associated with a version of the Windows CE operating system, although it will be recognized that other suitable operating systems may be used.
The analysis of the data is directed to the calculation of a parameter which is representative of conductivity within the portion of the body being monitored. It is the change of this parameter which provides an indication in increase in volume of body tissue as in the case of internal bleeding. This parameter can be monitored over time to determine the rate of internal bleeding. This parameter has been termed the “Resistivity Index” (RI).
In order to process the information, the abdomen may be modelled as a disk-shaped region. This is represented in FIG. 6 . As shown in FIG. 6 , the disk-shaped region 60 is represented by a 16×16 array 61 . A 16×16 array is used on the basis that 16 electrodes would be placed substantially equidistantly around the circumference i.e. abdomen, with the applied electric field patterns resulting in values for electrical conductivity in the surrounding tissue at each of 256 array locations. This is typical of EIT processing that has been conducted in the prior art. However in principle there is no restriction on the number of pixels used in an image. The array may be represented as a planar surface in two dimensions as shown in FIG. 6 , or may be mapped as a three dimensional cylindrical array of voxels.
The Resistivity Index involves adding up the total conductivity change observed within an image since this total change should reflect the total volume of anomaly that has appeared. In the case of the pixellation shown in FIG. 6 , calculating the Resistivity Index will just involve adding all pixel values since all pixels are the same area, but in general should allow for variations in pixel size and therefore in general the Resistivity Index should be calculated by summing the quantity (dσdS) where S is the region described in the model, e.g. a cylinder.
The equation defining this relationship may thus be expressed as shown below for a two-dimensional array:
R I = ∫ Ω ⅆ σ ⅆ S
or for a three-dimensional array:
R
I
=
∫
Ω
ⅆ
σ
ⅆ
V
Alternatively, these may be expressed in discrete format. For a two-dimensional array, the relationship below is given, where A p is the area of the pixel in question and TP is the total number of pixels:
R
I
=
∑
p
=
1
T
P
ⅆ
σ
ⅆ
A
p
For a three-dimensional array, the relationship below is given, where V p is the volume of the voxel in question and TP is the total number of voxels:
R
I
=
∑
p
=
1
T
P
ⅆ
σ
ⅆ
V
p
As shown in FIG. 5 , the processor 4 receives data from the on-patient module 2 which is operated on at 42 with the stored reconstruction matrix 43 to provide a reconstructed image 44 . The image per se may be displayed on the display 53 of the processor. This image is then combined with stored spatial filter matrix 45 to provide a filtered image 47 . A Resistivity index is then calculated at 49 . Preferably, the Resistivity Index is processed with a temporal filter 50 at 51 to remove breathing effects. Finally a scaling is applied to derive a blood volume estimation. This process is now described in more detail below.
The processor 4 therefore receives information as to the voltages measured between respective electrode pairs for a given measured current between a predetermined pair of electrodes. Measurements are received for all possible electrode pairs. In an instantiation using 8 adjacent current electrode pair positions and adjacent voltage measurements this comprises a total of 40 measurements—that is for each electrode pair to which current is applied, there are 5 voltage measurements to be taken. There are 8 different electrode pairs (including the two end electrodes)—making the total number of measurements 40 i.e. 8×5. In addition, the actual current value measured between each of the eight adjacent current pairs is measured and transmitted, making a total of 48 measurements sent to the processor 4 .
These 40 voltage measurements, normalised by dividing by each relevant current measurement, are saved to file in memory in the processor 4 .
Routines concerned with data collection are:
Routine Name
Function
select_measurement(int type);
Select Voltage, current or
battery check
setup_current(int cPair);
Requests particular current pair
be used
setup_shorted_current(int cPair);
Sets up shorted current source
(used for measuring offsets in
channels)
setup_volts(int vPair);
Requests particular voltage pair
be used
get_data(double *mean, double
Collect a particular data value
*sigma);
get_volt_data
get_curr_data
get_battery_data
DataOnly(int nsamp);
Collect complete set of data
without CSubject class
DataPresent( );
Ping
Other routines include:
BatteryVoltsOK( );
Entire routine to check on module battery voltage
And routines concerned with Higher Level Data collection include:
CollectShortedData( );
Collect a complete set of
shorted data
CollectData(CSubject *patient);
Collect complete set of data
BreathingCycleOk(double *respIndex);
Function to filter out breathing
cycle effects in measurements
Calibrate(BOOL *pflag, int *gflag,
Calibrate module
CSubject *patient, CVIndex *vValues);
BeltContactOk(int contactNo);
Checks that RMS noise on
differential voltage
measurements is low. In this
routine, for each adjacent
voltage pair, the differential
voltage is measured. If the
standard deviation in the
measurement is above a
threshold, then it is determined
that the contact of the belt to the
patient is bad.)
Processing these 40 measurements will give an indication of the conductivity of the tissue within the abdomen at the time that the measurement is taken. By repeating these measurements regularly at predetermined intervals, any changes in the measured conductivity indicates changes in the tissue composition e.g. through the presence of internal bleeding, as well as the approximate location of that change.
Once all the measurements have been saved to a file associated with the processor 4 , then the processor 4 is operable to carry out the Reconstruct routine mentioned above, to determine the rate of change of blood volume in the abdominal cavity, and, if necessary, trigger any alarm.
Routines concerned with data reconstruction include:
Routine Name
Function
LoadBMatrix(wchar_t *filename);
Reads in reconstruction matrix from file
void RemoveOffset(CCompleteMeas *data);
Removes offset from voltage
and/or current data
XferandNormalise(CSubject *mSubject,
Normalises voltage data by
CCompleteMeas *set);
current data, moves it to
CSubject data structure
Process(Csubject *exp, Csubject *ref,
Calculates vector of changes in
Csubject *w);
data from reference set. This
vector, denoted w, is multiplied
by the reconstruction matrix to
produce an image and hence an
estimation of blood volume
Reconstruct(CSubject *ref, CSubject *exp,
Process, reconstruct, estimate
RIType *ri, RIType *riblood, BYTE *pixel,
RI, embed image in larger
BOOL fStatus)
background, interpolate
d_sparsemult(double *colinput, double
Performs multiplication of
*colresult, int n, int length, SPARSELIST
voltage differences by
*eltlist);
reconstruction matrix
Partial(Csubject *b, RIType *ri);
Sum Pixel Values
Discretize(double **bhires, int *pixels);
Rescale hiresolution image to 0 -> 256
Reconstruct(CSubject *w, CRecon *b)
Multiply Processed data by
Reconstruction matrix
BloodConvert(RIType ri, RIType *riblood);
Convert Partial output (of
RIType) to blood volume
CalculateRate(RIType *rate, RIType *blood);
Estimate rate in terms of blood
quantity by dividing the quantity
determined by output of Partial
by time interval between this
data and reference data
collection time.
int CheckAlarm(RIType *rate);
Classify rate calculated below
by severity
In the present embodiment, eight electrodes are provided over half the abdomen—numbered “0” to “7”—and this must be accounted for, and which will be discussed further below.
By solving Laplace's equation for the region of interest (for the abdomen the region shape will usually be assumed cylindrical), the expected resultant electric field from current electrodes placed at positions around the circumference of the region 60 can be determined and can be used to derive expected conductivity values measured at any of the 256 locations within the array 61 , for current electrode pairs placed around the circumference. Thus, a 256×256 reconstruction matrix can be derived from these calculations for all possible electrode pairs. This reconstruction matrix will be used by the processor 4 to provide indications of changes in tissue conductivity within the abdomen—as will be discussed in more detail below.
This Reconstruct routine comprises a number of sub routines.
A flow chart for this reconstruct routine is as follows:
1. Process—that is calculate the difference between reference (ref) and current (exp) data sets to obtain vector, w
1.1. Reconstruct—this comprises multiplying the data vector w (256×1 matrix) by a reconstruction matrix (256×256) to obtain a reconstructed image.
2. If necessary, reduce spatial variation of image parameters by filtering, and apply temporal filtering to remove breathing artefacts 3. Integrate the pixels in (256×1 or 16×16) reconstructed image to obtain an RI estimate 4. Scale rate estimate using empirical sensitivity to obtain RI in terms of blood volume 5. Divide estimated blood volume by time interval between reference and current data sets 6. Depending on the rate that has been calculated, determine alarm category:
Thus, the process subroutine calculates the change between the present measurements and the last set of measurements—referred to herein as “exp” and “ref” respectively. Thus the change=(exp−ref). This is done by calculating a vector, w, of changes in data from the reference (“ref”) data, which can later be multiplied by the reconstruction matrix to produce an image and hence an estimation of blood volume—as will be discussed in more detail below.
The resultant 256×1 matrix is an approximate reconstructed image, and, from there, values for the “resistivity index” (RI) can be obtained by integrating pixel values in this reconstructed image.
This RI value can then be used to provide an estimate of blood volume. This is done by using empirically derived values of blood volume as a function of RI. The value of estimated blood volume can be used to determine the rate of change of blood value by dividing the estimated blood volume by the time interval between the reference (ref) and current (exp) data sets, and if this value falls greater than a predetermined value, then an alarm can be triggered.
As mentioned above, variations to the measurements that can be attributed to the patient's breathing can be accounted for within the processing—if required.
The elongate shape of the electrodes 7 , on the electrode belt 3 , enable correlation between the reconstructed image and the amount of tissue that the image represents. Elongate electrodes overcome the problem that the use of conventional-shaped (small diameter, circular) electrodes would present, in that, if an amount of tissue such as blood, were to move a small axial distance out of the plane of the electrodes then the resistivity index would be very different. Providing elongate electrodes—as described above—overcomes this problem to some extent and allows the vector/reconstructed image to be used to derive the information required.
The processor can be used to select to a variety of parameters for operation and function. For example, the following functions are accessible using the processor 4 :
Starts automatic collection at specified time intervals Stop automatic measurements Changes time interval between measurements Checks RMS noise appearing on adjacent electrode voltage measurements to determine contact quality Change the bleeding rate displayed between /sec, /min or /hr Executes a measurement Restarts measurements (change patient) Saves data from a session Checks for communication between the processor 4 and on-patient module 2 Setup communication (serial port) between the processor 4 and on-patient module 2 Checks Battery of module 2 Changes measurement frequency (at present measurements are made at 62.5 kHz). Change phase of measurement e.g. to take quadrature (reactive) measurements rather than resistive measurements.
It will be obvious to person skilled in the art, that variations are possible within the scope of the present invention. For example, the apparatus could be used to detect other fluids or other tissue—such as cancerous tissue—and in other areas of the human body, and could be adapted for use with animals.
It will be appreciated that advances in technology may lead to other ways of implementing certain aspects of the embodiments. Those skilled in the art will appreciate that the wireless communication may be implemented in other ways than that described.
In an adaptation of the embodiment, the belt is provided with some stiffness to hold the belt in curved form, having greater curvature proximate the ends. Such a belt is adapted to support electrodes very close to the sides of patient, maintaining those electrodes in good contact with the skin. In the present embodiment mechanical contact between the skin and electrodes is facilitated by adhesive electrode surrounds.
It will be clear that the invention is not restricted to a belt having the number of electrodes described in the embodiment. With too few electrodes, there is insufficient resolution of voltage variations across the abdomen, so that is becomes impractical to generate a clear enough reconstruction using this method. For some uses, acceptable results may be obtained with a belt having only four electrodes, although for most uses, at least 8 electrodes would be preferred. The number of electrodes might also be increased above eight to improve resolution. Clearly, such an array will require more processing power and data transmission bandwidth to be effective. But the effectiveness of taking this step will be limited in any event. As the number of electrodes is increased, the relative resolution improvement reduces so that the benefit becomes insignificant.
It is also to be appreciated that the purpose of the belt is to provide a straightforward means of applying a group of electrodes to the skin in the desired area. It would also be possible provide a linear array of electrodes which are adapted to contact the skin in an arrangement which would not be considered as a belt in conventional terminology. For instance, the electrodes might be associated with a mattress such that contact with the electrodes might be maintained merely because the patient was to lie upon the mattress. Such an array would still contact the abdomen on one side only and require EIT analysis in the same manner as previously described to thereby provide the monitoring for internal bleeding.
Throughout the specification, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. | An EIT system ( 1 ) adapted to detect internal bleeding in a body portion, the EIT system ( 1 ) comprising a plurality of electrodes ( 3 ) adapted in use to extend in a substantially linear orientation across one side only of the body portion and to be applied in electrical contact with the skin of the body portion, a current source adapted to cyclically apply an electric current between one pair of the electrodes ( 3 ), a voltage measuring means to measure the voltage across each of the other pairs of the electrodes resulting from the current, a data collection system ( 2 ) and a data analysis system ( 4 ) to analyze data resulting from the voltages that are measured by the voltage measuring means, wherein the analysis system ( 4 ) is configured to obtain quantitative information related to amounts and rates of conductive tissue changes occurring in the body, based on an EIT analysis equivalent to that obtained from data derived from electrodes spaced around the full perimeter of the body portion. Also disclosed is an electrode belt suitable for bioelectrical use and in particular for detection of change of volume of tissue in a body portion. | 0 |
BACKGROUND OF INVENTION
1. FIELD OF INVENTION:
The present invention relates a sound source for generating acoustic pulses in a well borehole.
2. DESCRIPTION OF PRIOR ART:
It has been desirable to be able to perform seismic exploration of subsurface formations around a well borehole and beneath the borehole. Conventional seismic exploration of the formations surrounding and below boreholes was done using vertical seismic profiling (VSP) techniques. Typically, shots were fired in shallow boreholes, and seismic waves recorded by a detector lowered into the deep borehole on a logging cable and positioned at successive depths. One shot was fired for each depth. One trace was recorded representing the direct arrivals and reflections that could be observed by a detector at the surface from each shot. If multiple offsets were desired, several shots had to be fired at different radial distances from the borehole, and this procedure repeated as the detector was moved to different depths in the borehoe. A complete multiple offset VSP survey of a borehole was a very time-consuming operation and thus was not done very often because of the expense involved.
It has long been known that in theory the shots could be detonated in the deep borehoe, and multiple detectors could be located at the surface to record all the offsets of a multiple offset VSP simultaneously. This procedure has been named "Reversed VSP." The reason this has not become an operational technique is the difficulty of getting a suitable deep hole sound source. Explosives might be used; however, only a small number of shots can be lowered in the hole at one time. A complete survey involves many shots and would require many trips into the hole using conventional explosive devices such as perforating gun technology. Additionally, due to the limitation on the size of charge that can be detonated in the borehole, several shots would probably be required at each depth. This would further multiply the number of trips into the hole.
Acoustic pulses could be generated by piezoelectric crystals and other devices lowered into the borehole by a well logging cable. The cable could supply the devices with continuous electrical power and avoid the problem of making multiple trips into and out of the hole. The principal problem with this technique is that the amount of power that could be transmitted through a logging cable would be low, typically about 200 to 300 watts. The pulses generated would thus be much lower in energy than those generated by explosives; or, alternatively very long time periods would be required to store up enough energy in the downhole tool to discharge into a high-energy pulse. In either case, very long periods of time would be required at each depth in the borehole to transmit sufficient energy to produce acceptable signal-to-noise ratios at the detectors on the surface. Examples of such a seismic source receiving and storing operating power from the surface via a conduit are U.S. Pat. No. 3,979,140 and U.S. Pat. No. 4,682,309.
There have been attempts in the prior art to form acoustic signals in well boreholes. For example, in U.S. Pat. No. 2,898,084 a drill string was lifted so that a rotary drill bit was raised from of the well bottom. During such lifting, telescoping inner and outer members armed a seismic shock source. When lifting force was released, surfaces on the inner and outer members transferred the weight of the drill string to the drill shortly after the drill bit had hit the well bore bottom. A disadvantage with this was that the rotary drill bit was being used as a hammer or ram against the well bottom. Other hammer and anvil techniques were disclosed in U.S. Pat. No. 4,569,412 and U.K. Pat. No. 2,147,700B.
Another method, based on the "water hammer" effect, was to temporarily block the flow of drilling mud, then release flow. The surge in flow caused an acoustic pulse. Examples of this technique were disclosed in U.S. Pat. Nos. 3,993,974 and 4,252,209.
SUMMARY OF INVENTION:
Briefly, the present invention comprises a new and improved seismic or sound source for generating acoustic pulses in well boreholes. A body member is attached to a lower end of a drill string and lowered into a well borehole filled with drilling fluid, commonly termed drilling mud. A reservoir in the body member contains a compressed gas, usually air. When a desired depth in the borehole is reached, the pressure in the column of drilling mud is increased. The increased drilling mud pressure further compresses the gas in the reservoir and causes a charge of drilling mud to be stored in a chamber in the body member. At the same time, a movable shuttle in the body member adjacent the chamber is armed. The movable shuttle is then triggered, forcing the charge of mud in the chamber out through mud ports in the body member into the well borehole. A shoulder in the body member adjacent the chamber limits motion of the shuttle. Motion of the charge of mud continues, however, for an interval after shuttle motion ceases. This causes a cavitation zone in the mud adjacent the mud ports. When the weight of drilling mud collapses in the cavitation zone, a seismic impulse is formed. Seismic impulses may be formed in this manner at the same depth, or a successive number of depths, repeatedly during a single run of the drill string in the well boreholes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are elevation views, taken partly in cross-section, of a seismic source apparatus according to the present invention;
FIGS. 2A and 2B are elevation views, taken partly in cross-section, of the apparatus of FIGS. 1A and 1B, respectively, with portions thereof in different positions;
FIGS. 3A and 3B are elevation views, taken partly in cross-section, of the apparatus of FIGS. 1A and 1B, respectively, with portions thereof in different positions;
FIGS. 4A and 4B are elevation views, taken partly in cross-section, of the apparatus of FIGS. 1A and 1B, respectively, with portions thereof in different positions; and
FIGS. 5A and 5B are elevation views, taken partly in cross-section, of the apparatus of FIGS. 1A and 1B, respectively, with portions thereof in different positions.
DESCRIPTION OF PREFERRED EMBODIMENT
In the drawings, the letter S (FIGS. 1A and 1B) designates generally a seismic source according to the present invention for forming acoustic impulses in a well borehole filled with drilling mud or fluid. The source S includes a body member B composed of an upper section 10 (FIG. 1A) and a lower section 12 (FIG. 1B).
The upper section 10 has a threaded pin connection 14 formed at an upper end thereof for attaching the source S at the lower end of a conventional drill string of pipe. An upper opening 16 is formed in the upper section 10 internally of the pin connection 14 to receive drilling mud pumped through the drill string in the conventional manner.
A central internal tubular passageway 18 (FIGS. 1A and 1B) is formed extending through the upper section 10 for conveying mud downwardly from the upper opening 16. A cylindrical upper reservoir 20 is formed in the upper section 10 between an inner wall 24 surrounding the passageway 18 and an outer wall 26. Upper reservoir 20 is charged with a suitable gas, usually air for reasons of economy, through a conventional charging port.
An upper portion 28 of upper reservoir 20 is in fluid communication with upper opening 16 through a check valve 30 and a control valve 32. The control valve 32, as well as the other control valves of the source S set forth below, are remotely controlled from the surface by coded acoustic pulses sent from conventional instrumentation at the wellhead through the column of drilling mud to conventional control instrumentation in the source S in the conventional manner. Such instrumentation may be located, suitably protected in the opening 16. The time of the seismic pulse formed in the source S is detected by a pressure detector and precision clock in the downhole instrumentation. This information is transmitted to the surface instrumentation by conventional coded acoustic pulses through the borehole mud column. This information can also be obtained by a geophone on the drill pipe at the surface with appropriate correction for the known acoustic velocity of the steel drill pipe.
An annular pressure containment shuttle 34 is movably mounted in the upper reservoir 20 about the inner wall 24. O-rings or other suitable seals 36 are provided for the purpose of fluid sealing against the inner wall 24 and the outer wall 26. A restraining shoulder 37 is formed in a lower portion of the upper reservoir 20 to limit downward movement of the pressure containment shuttle 34. A control valve 38 (FIG. 1B) is mounted in the upper reservoir 20 on a surface 40 of a wall 42. The wall 42 separates the upper reservoir 20 from an annular chamber 44 formed between cylindrical wall members 46 and 48.
A tubular containment sleeve 50 is mounted on the upper section 10 at its lower end. The containment sleeve 50 has an inner shoulder 52 which is slidably movable in a recessed surface section 54 of the upper section 10. A radially extending port 56 is formed extending outwardly from a mud valve chamber 58 to an annular space 60 formed between the containment sleeve 50 and the recessed surface 54. The annular space 60 is sealed at its upper end by an O-ring or other suitable seal 62.
The mud valve chamber 58 is in fluid communication with the central passageway 18 to receive drilling mud therefrom. The mud valve chamber 58 is located within the cylindrical wall member 46. An annular space 64 is formed between the surface 54 of the outer wall member 48 and the lower portion of the containment sleeve 50. The annular space 64 is suitably scaled in a like manner to the space 60. A port 66 formed in outer wall member 48 permits fluid communication between chamber 44 and space 64.
A mud valve cylinder 70 is mounted to the wall member 46 within the mud valve chamber 58. A check valve 72 and a control valve 74, which is remotely controlled in the manner indicated for control valve 32, are mounted with the wall member 46. The valves 72 and 74 are in fluid communication through conduits 76 and 78, respectively, with an upper portion 80 (FIG. 2B) of the mud valve cylinder 70. A mud valve piston 82 is mounted within the mud valve cylinder 70 having upper and lower sealing rings 83 and 84, respectively. A port 85 provides fluid communication between the interior of mud valve cylinder 70 and the annular chamber 44. A check valve 88 is mounted on a lower wall 90 of the mud valve cylinder 70 to permit fluid flow from the mud valve cylinder 70 to the mud valve chamber 58.
A radial port 92 permits fluid communication between a lower portion 93 of mud valve cylinder 70 and the recess 60 (FIG. 2B), depending upon the position of the container sleeve 50 (FIG. 1B). Suitable sealing rings 94 are mounted in the wall member 48 to seal the port 92.
A mud valve 100 is composed of a valve stem 102 mounted with the valve piston 82 which extends through sealed ports at each end of the mud valve cylinder 70 and a plug member 104 which is adapted to seal against a tapered surface 106 formed in a lower wall member 108 of the upper section 10 adjacent an opening 110. Suitable seals are mounted in the tapered surface 106 to seal against the plug member 104 when it is in the closed position (FIG. 2B).
A remotely controlled valve 116 is mounted at a lower portion of the chamber 44 for fluid communication through a conduit 118 with portions of the lower section 12, for reasons to be set forth below. Between the upper section 10 and the lower section 12 of the source S is a mud chamber 120 which has outlets for mud through mud ports 122 formed in a wall 124 in the body member B.
The lower section 12 extends beneath the mud chamber 120 and includes a cylindrical firing chamber 124 formed within an outer wall 126. A firing shuttle 128 is slidably movable within the firing chamber 124 between an upper position (FIG. 1B) and a lower position (FIG. 3B). An inwardly extending tapered decelerating shoulder 130 is formed at an upper end of the lower section 12 adjacent the mud chamber 120 to limit upper movement of the firing shuttle 128.
A second or lower reservoir 132 is formed within a lower portion of the lower section 12. The lower reservoir 132 is also simultaneously charged with a suitable gas, usually air, through a conventional sealable charging port. The second air reservoir 132 is in fluid communication through a number of ports, exemplified as 134 and 136, with the firing chamber 124 unless the firing shuttle is in its lower position (FIG. 3B). The lower air reservoir 132 is also in fluid communication through port 136 and a conduit 138 formed in an outer wall 126 of lower section 12 with the chamber 44 in the upper section for pressure equalization purposes.
The conduit 118 extending from control valve 116 in the upper section 10 is connected by a conduit or tube 140 and a port 142 formed in a lower wall 144 to the firing chamber 124. A check valve 146 is mounted in the wall 144 to permit fluid exit into the air reservoir 132 from the firing chamber 124. A lower wall 148 of bottom section 12 forms a closure for the lower reservoir 132.
In the operation of the present invention, upper reservoir 20 and lower reservoir 132 are charged with air to a suitable pressure, for example 2000 psi, and the source S is attached at pin connection 14 to the lower end of a drill string. The source S and the drill string are then lowered into the well bore. As the source goes into the well borehole, control valves 38, 74 and 116 are in the closed position. Further, the containment sleeve 50 is in the upper position (FIG. 1B) so that drilling mud may circulate freely through the open ports 122.
At some depth in the well bore which is shallower than a depth where the hydrostatic pressure of the drilling mud equals the air pressure stored in reservoirs 20 and 132, lowering of the source S is stopped to fire a seismic shot or acoustic impulse. Control valve 74 is momentarily opened, allowing air pressure to close the mud valve 100 (FIG. 2B). After the mud valve piston 82 passes the port 85, the mud valve 100 is pushed downwardly by air entering the port 85, allowing control valve 74 to be closed. Any mud trapped in the space 93 below the mud valve piston 82 will be forced from the chamber 93 through the check valve 88.
With the mud valve 100 in the closed position (FIG. 2B), the pressure on the column of mud in the well borehole is increased by the rig pump at the surface to a suitable level above hydrostatic, such as for example, 2000 psi. This results in the source S being subject to a pressure of 2000 psi above normal hydrostatic pressure. The pressurized mud enters the upper portion 28 of the upper reservoir 20 through the check valve 30, forcing the pressure compensation shuttle 34 downwardly (FIG. 2A) to a position where the pressure in the lower portion of the reservoir 20 equals that of the mud in the upper portion 28 of the reservoir 20.
As the mud pressure rises above the air pressure in upper reservoir 20, mud enters the port 56, expanding the space 60 and forcing the containment sleeve downwardly to a position (FIG. 2B) where the mud ports 122 are sealed. As the containment sleeve 50 passes the port 92, mud begins to enter the mud piston cylinder space 93 beneath the mud valve piston 82, forcing the mud valve piston 82 upward.
When the mud valve piston 84 passes the port 85, the remaining air in the chamber 80 is forced out of the mud valve cylinder 70 through the check valve 72. With the port 85 now between the seals 83 and 84 on the mud valve piston 82, the mud valve piston 84 is retained in the open position (FIG. 3B).
With the mud valve 100 open, high pressure drilling mud enters the chamber 120 and forces the firing shuttle 128 downwardly into the firing chamber 124 to a bottom position (FIG. 3B), working against the air pressure in lower reservoir 132. As the firing shuttle 128 passes the ports 134 and 136, the remaining air below the firing piston 128 is forced into the lower reservoir 132 through the check valve 146. With the ports 134 and 136 between the seals on the firing shuttle, the firing shuttle remains at the bottom of the firing chamber 124. Control valve 38 is opened to allow the pressure to equalize between the upper reservoir 20 and the lower reservoir 132. The air pressure in both reservoirs is at this time now about 2000 psi above the hydrostatic pressure (FIG. 4B).
The pressure on the column of drilling mud in the borehole is now reduced to atmospheric pressure, reducing the ambient pressure at the source S in the well borehead to the hydrostatic pressure of the column of drilling mud above it. At this time, air pressure from lower reservoir 132 passes through port 66 into an annular space 64, forcing the containment sleeve upwardly to a position (FIG. 4B) opening the mud ports 122. Control valve 74 is opened momentarily again to move the mud valve 100 to its closed position (FIG. 5B), arming the seismic sources to form a seismic impulse when needed.
To fire the source S, control valve 116 is opened, permitting the pressurized air in the chamber 44 to pass through the conduit 118, tube 140 and port 142 into the firing chamber 124 beneath the firing shuttle 128, forcing the firing shuttle 128 above the ports 134 and 136. At this point, a large volume of pressurized air from the lower reservoir 132 enters the firing chamber 124 through the ports 134 and 136. The air from air reservoir 132 accelerates the firing shuttle 128 upwardly in the firing chamber 124. As the firing shuttle 128 moves upwardly in the firing chamber 124, mud in the firing chamber 124 above the firing piston 128 is forced outwardly through the open mud ports 122 upwardly into the drilling mud column in the wellbore, causing the mud column to move upwardly at an increasing velocity. As the firing shuttle 128 nears the decelerating shoulder 130, the inwardly extending shoulder 130 limits drilling mud flow to reduce the velocity of the upwardly travelling shuttle 128. When the firing shuttle 128 contacts the decelerating shoulder 130, movement of the firing shuttle 128 is stopped. However, the mud column in the wellbore will continue to move upwardly briefly for a moment, causing a cavitation zone to be formed adjacent the mud ports 122. Thereafter, the mud column decelerates and begins downward movement, collapsing the cavitation zone and creating an acoustic impulse which is transmitted into the earth formations adjacent the well borehole. The seismic source S is now prepared to repeat the foregoing sequence, forming another seismic impulse at the same location in the well bore. Alternatively, the source S can be moved downwardly in the well bore to a depth for another shot or sequence of shots.
Because of the upward movement of the firing shuttle 128 during the formation of an acoustic impulse, the pressure in the lower reservoir 132 is somewhat lower than it originally was. This, however, permits the containment sleeve 50 to be lowered during the next shot cycle without having to use a mud pressure higher than that of the preceding shot cycle.
Caution should be exercised in moving the sound sources downwardly in the well to a point where the hydrostatic pressure of the column of drilling mud exceeds the pressure in the lower reservoir 132. Should that occur, the containment sleeve 50 could not be moved. Further, the mud valve 100 would be held open and could not be closed.
Once the source S has reached the bottom of the well borehole and before returning the source S to the surface, the pressure in the upper reservoir 20 and lower reservoir 132 can be lowered to a safe value by opening valves 32 and 38. Alternatively, the pressure in the reservoirs 20 and 132 may be incrementally reduced as the source S is being removed from the well, permitting additional seismic pulses or shots to be made as the source S is being removed from the well borehole.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made without departing from the spirit of the invention. | A sound source capable of generating high energy acoustic pulses is lowered into a well borehole. A chamber of high pressure air in the source provides the energy for the pulses. A firing mechanism in the source is armed using increased pressure on the drilling mud in the well borehole. The pressurized mud is stored in a chamber in the source having closable ports. When the firing mechanism is operated, the ports are open, forcing the mud from the source into the borehole mud column and causing a cavitation zone in the mud at the ports. When the cavitation zone collapses, an acoustic energy pulse is formed. Pulses may be formed in this manner at the same depth or a number of depths in the well bore during a single run of the source in the well. | 6 |
BACKGROUND
Scientists and engineers often employ seismic surveys for exploration, archeological studies, and engineering projects. Seismic surveys can provide information about underground structures, including formation boundaries, rock types, and the presence or absence of fluid reservoirs. Such information greatly aids searches for water, geothermal reservoirs, and mineral deposits such as hydrocarbons and ores. Oil companies in particular often invest in extensive seismic surveys to select sites for exploratory oil wells.
Conventional seismic surveys employ artificial seismic energy sources such as shot charges, air guns, or vibratory sources to generate seismic waves. The sources, when fired, create a seismic “event”, i.e., a pulse of seismic energy that propagates as seismic waves from the source down into the earth. Faults and boundaries between different formations create differences in acoustic impedance that cause partial reflections of the seismic waves. A seismic sensor array detects and records these reflections for later analysis. Sophisticated processing techniques are applied to the recorded signals to extract an image of the subsurface structure.
Various techniques have been proposed to eliminate the conventional seismic energy sources from this process. These techniques are often termed “passive seismic” or “micro-seismic” imaging. See, e.g., U.S. Pat. Nos. 5,377,104 and 6,920,083; and B. S. Artman, “Passive Seismic Imaging”, Poster S11E-0334, AGU Fall Meeting, December 2003. The proposed techniques generally rely on environmental seismic events such as earthquakes, hydraulic fracturing, drilling operations, or operations of heavy construction equipment. Typically, the proposed techniques employ cross correlation to extract seismic event information, and thereafter the processing can proceed in much the same fashion as conventional seismic survey processing.
Thus existing seismic imaging techniques rely on event-based analysis of wave propagation patterns. Where passive seismic imaging techniques are rendered unsuitable due to the absence of identifiable seismic events, surveyors are required to employ artificial seismic energy sources. Use of such sources can add significant expense to exploratory seismic surveys.
SUMMARY
Accordingly, there is disclosed herein various systems and methods that construct subsurface images from diffuse seismic energy. Various disclosed system embodiments include multiple seismic sensors that each convert received seismic energy into one or more seismic signals. One or more processor combine the seismic signals to determine a subsurface map. As part of determining the map, the processor(s) systematically focus the array of seismic sensors on each bin in the subsurface volume of interest. In this manner each bin becomes a focal point of the array. For each bin, the processor(s) analyze the seismic wave travel time to each seismic sensor and apply a corresponding time shift to align the seismic signals with a uniform travel time. The time-shifted seismic signals are then combined to determine an intensity value for seismic energy radiating from the focal point. A subsurface map can then be derived from the intensity value as a function of position.
Various disclosed method embodiments include: receiving signals from multiple seismic sensors; determining an intensity value for each of a set of focal points; and storing said intensity values. For each focal point, the intensity value determination includes: selecting a time offset for each seismic sensor signal; combining the time-offset seismic sensor signals to obtain a focused-array signal; and calculating an intensity value for said focal point. The time offsets are designed to provide a uniform travel time from the focal point.
As will become apparent, other system and method embodiments are also disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the various disclosed embodiments can be obtained when the following detailed description is considered in conjunction with the following drawings, in which:
FIG. 1 shows an illustrative survey environment;
FIG. 2 is a block diagram of an illustrative survey system;
FIG. 3 shows illustrative seismic survey traces;
FIG. 4 shows an illustrative data volume with a selected cell;
FIG. 5 illustrates a diffuse seismic imaging technique;
FIGS. 6 a - 6 c show an illustrative time shifting technique applied to seismic survey traces;
FIG. 7 shows an illustrative imaging method; and
FIG. 8 shows an overhead view of an illustrative sensing array being divided into zones.
While the disclosed systems and methods are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description related thereto are not intended to limit the disclosure to the particular embodiments shown and described, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION
Existing seismic survey techniques appear to treat the Earth's subsurface as a relatively quiet environment with separate and identifiable shock waves emanating from discrete seismic events. The present disclosure takes a new approach, treating the Earth's subsurface as a continuously noisy environment permeated with diffuse seismic energy. A comparison of the two circumstances may be analogized to a comparison of a dark room with irregular flashes of a strobe light, and a room lit with diffuse ambient light. As will become clear from the ensuing discussion, it may be considerably easier to form a meaningful image with the new treatment.
FIG. 1 shows an illustrative environment for logging with diffuse seismic energy. A set of seismic energy receivers 102 is positioned in a spaced-apart arrangement on the earth's surface 104 . The receivers 102 are coupled to a central processing and/or recording unit 106 that receives the seismic signal data collected by the receivers. Diffuse seismic energy permeates the earth 110 , reflecting from acoustic impedance discontinuities. Such discontinuities may be created by faults, boundaries between formation beds, and boundaries between formation fluids.
Seismic energy reflections from discontinuities may be treated as acoustic energy emanations from a set of point sources 112 that together make up the discontinuity. When viewed in this manner, the acoustic impedance discontinuities will appear as bright spots, i.e., as radiators of seismic energy. The intensity of the radiated energy is a function of the reflection coefficient for the discontinuity.
FIG. 2 shows an illustrative block diagram of seismic survey system electronics. The receivers 102 include transducers to convert the seismic wave energy into electric signals, and may further include electronics to filter, amplify, and convert the electric signals into digital data. The digital data may be communicated to the central unit 106 via a bus 202 , or alternatively may be communicated via a dedicated information pathway or via a wireless connection. The central unit 106 also collects position information for each of the receivers and any other parameters that may be useful in interpreting the seismic signal data (e.g., number of receivers, type of receivers, calibration information, and so on). The location information and other parameters may be provided via an independent interface 204 such as a user interface that allows manual entry of such information, or a global positioning system (GPS) interface that collects such information from one or more GPS receivers.
In some embodiments, the central unit 106 processes the seismic signal information as it is collected, systematically scanning the subsurface volume of interest and compiling a map in real time. Such embodiments may avoid any need for storing large volumes of seismic data for later analysis. Nevertheless, the central unit 106 may also or alternatively store the collected data on an information storage medium.
Central unit 106 may use any suitable information storage medium. Due to the large volume of information needed to represent seismic survey data, the information storage medium is generally some form of magnetic medium, e.g., disk drives or magnetic tape. However it is expected that the necessary storage capacity may also be provided by optical media or integrated circuit memories, though the associated cost may be somewhat higher. In an alternative embodiment, recording unit 106 simply gathers the data from the receivers and transmits the data in real time to a remote location such as a central storage facility.
In some embodiments, central unit 106 does not itself compile the map, but rather communicates information to a general purpose digital data processing system 206 . The communication 208 may take place in any of various ways, including transmission via a wired or wireless communications link, and by physical transport of an information storage medium. System 206 may process the traces to focus the sensor array and determine one or more intensity values for each focal point. (As discussed further below, determination of a given focal point's intensity value as a function of offset may enable velocity field estimation.)
A map of the intensity value as a function of focal point will provide an image of the subsurface structure. Numerous image and seismic processing techniques may be applied to refine the map before it is stored or displayed. A map storage or display unit 210 may take the form of an integrated memory or other information storage medium, a computer printout, and/or a computer monitor that displays the map to a user. Three-dimensional image viewing techniques may alternatively be employed.
FIG. 3 shows illustrative seismic signals detected and sampled by receivers 104 . The signals indicate some measure of seismic wave energy as a function of time (e.g., displacement, velocity, acceleration, pressure), and they are digitized at high resolution (e.g., 24 bits) at a programmable sampling rate. As discussed further below, seismic sensors can be grouped in different ways to form variable-focus lens-arrays that scan the subsurface volume of interest.
FIG. 4 shows a “data cube”, i.e., a three dimensional array of data values. (Despite the use of the term “cube”, the dimensions of the data cube do not have to be equal.) The data cube represents some seismic attribute throughout the subsurface volume of interest. The three-dimensional array preferably consists of uniformly-sized cells, each cell having a data value representing the seismic attribute for that cell. Though seismic energy reflection intensity will be the primary attribute described here, other seismic attributes are also interesting and can be derived from the measured seismic signals. Thus various seismic attributes may be represented, and in some embodiments, each cell has multiple data values to represent multiple seismic attributes. Examples of other seismic attributes include reflectivity, acoustic impedance, acoustic velocity, and density. The data cube format more readily lends itself to computational analysis and visual rendering, and for this reason, the data cube may be termed a “three-dimensional image” of the survey region.
FIG. 4 shows a selected cell 402 . Various disclosed imaging embodiments employ a scanning technique, in which each cell in the data cube is systematically selected in turn. As shown in FIG. 5 , the selected cell 402 becomes a focus point for the array of seismic sensors 102 . For a selected cell 402 , central unit 106 focuses the array by combining time-shifted signals from the seismic receivers 102 . In some embodiments, central unit 106 determines a maximum travel time 502 from the selected cell 402 to a receiver in the array, and uses the travel time 502 as a uniform travel time that defines a wave front 503 . Central unit 106 determines for each receiver a time shift that, when summed with the travel time from the selected cell, adds up to the uniform travel time. Note that the uniform travel time can be chosen arbitrarily and may even be set to zero, so that the time shifts are simply the negative of the calculated travel times.
To demonstrate the motivation behind the time shifting performed by central unit 106 , FIG. 6 a shows the signals that the seismic receivers S 0 -S 2 would receive from focal point 402 . For the sake of illustration, FIGS. 6 a - 6 c omit the noise and interference that would be expected from other seismic energy reflectors. FIG. 6 a shows that due to the different travel times 502 , 504 , 506 to each of the receivers, the signals are misaligned. As can be seen from STOT (a sum of the sensor signals represented by overlaying the different signals), the misaligned signals from focal point 402 largely interfere destructively where they overlap in region 601 . FIG. 6 b shows time shifts 602 , 604 , 606 to be applied to the sensor signals by the central unit. In this example, the time shifts correspond to the travel times 502 , 504 , 506 in accordance with the calculations of the central unit 106 . (The individual signals may also be scaled to account for the fall-off in intensity for the more distant receivers due to the inverse-square law.) As shown in FIG. 6 c , the time shifted signals are summed or combined via a weighted sum to obtain a focused-array signal 608 . It can be seen that when aligned, the signals from focal point 402 add constructively. The relative intensity value for the focal point may be calculated as the energy of the focused-array signal divided by the sum of the energies for the individual signals. Other coherence or correlation measures may alternatively be used to calculate the relative intensity value for the focal point.
In practice, the seismic receivers will receive energy not only from focal point 402 , but also from all the reflectors of seismic energy. This interfering signal energy may even be expected to largely obscure the seismic energy from focal point 402 . However, this interfering signal energy, much like the signal in region 602 of FIG. 6 a , is expected to be largely suppressed by the summing operation. With the appropriate time shifts, only the seismic energy from the focal point will interfere constructively and dominate the focused-array signal. Once a new focal point is selected, energy from the previous focal point will now be considered interference, but will be suppressed due to the use of different time shifts that misalign that signal energy during the summing operation.
Returning to FIG. 5 , various methods may be used to calculate travel times to each receiver. In some embodiments, a constant seismic wave velocity is assumed, so that the calculated travel time to a given receiver is proportional to the distance of that receiver from the focal point. In other embodiments, velocity values are determined for each cell, ray paths are determined, and the travel times through each cell are calculated and aggregated to determine the travel time. In some embodiments, the ray paths are adjusted to account for refraction as the seismic wave passes from one velocity region to another.
Many seismic wave velocity determination methods are known in the art, and any suitable method can be used. As one example, seismic wave velocity can be estimated for a formation bed based on the offset angle dependence of the reflection coefficients at the boundaries. In other words, receivers detecting energy radiated from the focus point at different offset angles β can determine a dependence of the intensity on the offset angle. The velocity relationship across the boundary can then be determined based on the Zoeppritz equations or other physical models. As another example, Snell's law causes the apparent position of a given feature to vary based on the offset angle β. (In some embodiments, features are identified as intensity values that exceed a threshold value.) Formation velocities can be estimated based on this position dependence. The formation map and velocity map may be iteratively calculated, first determining a formation map and then alternately refining the velocity map and the formation map to improve the accuracy of each.
FIG. 7 is a flow diagram of an illustrative diffuse seismic imaging method that in some embodiments is implemented by central unit 106 . Beginning in block 702 , the central unit receives specifications of the desired survey volume and other parameters from a user. The user may specify the extent of the subsurface volume of interest, cell dimensions, time limits, scanning algorithms, and other parameters that the system is configured to employ. In block 704 , the central unit identifies the positions of the seismic sensors in the array relative to the subsurface volume of interest. In some embodiments, each of the sensors is equipped with a global positioning system (GPS) sensor that enables precise determination of the sensor's position.
In block 706 , central unit 106 scans through the cells in a narrow column beneath the center of the sensor array, measuring intensity as a function of position and offset angle. From these measurements, the central unit 106 determines a crude model of the subsurface structure, including estimates of bed boundary positions. In block 708 , central unit 106 estimates bedding orientations and velocities within each bed from the azimuthal and offset angle dependence of the intensity measurements. In block 710 , central unit 106 refines the bed boundary position determinations using the estimated velocities. In block 712 , central unit 106 systematically scans through the subsurface volume of interest, focusing in turn on each cell in the volume of interest. The signal collection period for each cell may vary from a few seconds to a few hours. An intensity value is determined for each cell, and the dependence as a function of offset angle may be used to estimate velocities along the ray paths from the focus point to the receivers. The velocity estimates are used to update the velocity map for use in imaging deeper layers.
Once intensity and velocity maps have been found, the maps may be refined in block 714 with additional scans through the volume. In some embodiments, the data from subsequent scans is combined with data from preceding scans, while in other embodiments, the previous data is simply replaced. Each subsequent scan may be performed at the same resolution, or with higher resolution (smaller cell sizes) if time permits.
FIG. 8 shows an overhead view of an illustrative sensing array to demonstrate the determination of azimuth and offset angle dependence. The array of FIG. 8 is divided into zones represented by circles surrounding the current focus point. Zone 802 is directly above the selected focus point and accordingly the receivers in zone 802 have the smallest offset angle β. Zone 804 contains the receivers having a range of slightly larger offset angles. Similarly, zones 806 and 808 cover ranges of increasing offset angles. Intensity measurements (properly normalized for the number of receivers) in each of the zones can reveal the dependence of the intensity on offset angle.
The array zones 804 - 808 may be divided into sectors, each sector covering a range of azimuthal angles α. In FIG. 8 , the azimuthal angle α is shown as being measured relative to true north, but other reference points can alternatively be used. The sectors of FIG. 8 each cover 45° of arc, but other sector sizes can be employed. An azimuthal dependence of intensity may be indicative of a dipping formation boundary, or may reveal other phenomena such as highly directional faults.
The imaging techniques disclosed herein may be likened to the use of beam-forming techniques to create a synthetic lens with a variable focal length and depth of field. The lens can be focused anywhere below or beyond the sensor array. To improve image quality, the array's depth of field around the focal point can be reduced with additional, more widely distributed seismic sensors. The accuracy (or relative “brightness”) of measured intensity values can be improved by increasing the measurement time and/or increasing the number of seismic sensors in the array. It is expected that high intensity values will indicate bed boundaries, whereas low intensity values will indicate space between the bed boundaries.
The array's ability to continuously vary the focal point for real-time measurements may enable unprecedented real-time monitoring of changes to subsurface formations. In so-called “4D” monitoring applications that provide long-term monitoring of reservoirs and other seismic fields, the sensors may be permanently deployed to detect subsurface changes over the course of months or years. Though 4D monitoring can be carried out continuously, it may be more practical to employ the permanently installed sensors on a periodic basis, e.g., to perform scans on a monthly basis.
In some embodiments, central unit 106 will process the seismic signals to measure the intensity of only one focal point at a time. In other embodiments, central unit 106 includes multiple modules that can each provide the appropriate time delays and summations for a corresponding focus point, so that multiple focal point measurements can be made simultaneously from a given set of seismic traces. In such embodiments, it becomes feasible to extend the measurement time for each focal point over multiple days or weeks to bring out boundary details that would otherwise be obscured or too weak to be resolved.
In some embodiments, the array is divided into independently operating sub-arrays, with each sub-array scanning its own focal point through the volume of interest. Such subdivision may greatly speed up the early stages of the scanning process. For scanning at shallow depths, a larger array may offer no advantage over a smaller array. Hence the portion of the array actively scanning a selected focal point may increase with depth.
Seismic imaging techniques disclosed herein can enable seismic surveys to be performed without artificial sources of seismic energy, significantly reducing survey costs. With the diffuse seismic energy model, the actual sources of seismic energy are unimportant. Only their existence is important. Since artificial energy source activity is unnecessary, the scanning process may begin as soon as a sufficient number of sensors are deployed, and continue even as additional sensors are being deployed and even as sensor retrieval begins. In large arrays this scanning time will be continuous over several days. As sensors are coupled into or removed from the system, their measurements can be easily incorporated into or dropped from the imaging calculations.
The receiver frequency band may be adaptively adjusted to reject undesired frequencies. However, it is expected that the imaging process will benefit from keeping the receiver frequency band wide enough to cover all seismic frequencies that propagate efficiently.
Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. As one example, the seismic receivers may be autonomous recorders that are deployed to record seismic signals that are later collected together for processing. As another example, various passive seismic imaging techniques may also be applied to the seismic signals from the array to obtain additional information about the subsurface volume of interest. It is intended that the following claims be interpreted to embrace all such variations and modifications. | Systems and methods are disclosed to construct subsurface images from diffuse seismic energy. Various disclosed system embodiments include multiple seismic sensors that each convert received seismic energy into one or more seismic signals. One or more processor combine the seismic signals to determine a subsurface map. As part of determining the map, the processor(s) systematically focus the array of seismic sensors on each bin in the subsurface volume of interest. In this manner each bin becomes a focal point of the array. For each bin, the processor(s) analyze the seismic wave travel time to each seismic sensor and apply a corresponding time shift to align the seismic signals with a uniform travel time. The time-shifted seismic signals are then combined to determine an intensity value for seismic energy radiating from the focal point. A subsurface map can then be derived from the intensity value as a function of position. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to detection of concealed objects or substances that could be embedded in a host medium. More particularly, the invention relates to detection explosive substances from a distance that are embedded or surgically placed inside the human body.
BACKGROUND OF THE INVENTION
[0002] Objects embedded in opaque media or enclosed in high water content packaging are difficult to detect without sophisticated imaging equipment (e.g. MRI scanners, which are slow and do not tolerate motion). Water molecules have a broad relaxation frequency near 20 GHz (depending on state and temperature), which manifests itself as dispersion and energy absorption in the GHz frequency range. Direct microwave backscatter or projection imaging has therefore not proven effective.
[0003] The large tissue (or in general packaging) attenuation in traditional microwave imaging leads to a severe tradeoffs between attenuation (penetration) and resolution/contrast. In addition to that, with non-contact detection tissue presents a large initial reflection that renders traditional backscatter/imaging algorithms ineffective for objects buried deep in tissue.
[0004] To provide sufficient resolution to make detection accuracy acceptable, the imaging frequency has to approach 10 GHz (3 cm wavelength in air). Most of the research in microwave medical imaging has concentrated on low frequencies or on tissue with low-water content and loss (e.g. fat).
[0005] What is needed is a method of detecting explosive substances from a distance that are embedded or surgically placed inside the human body.
SUMMARY OF THE INVENTION
[0006] To overcome the teachings in the art, a method of detection of substances embedded in a human host is provided that includes emitting from a coherent beamforming electromagnetic excitation source a spatially scanning, temporally pulsed, electromagnetic excitation signal toward a human host separated by air from the electromagnetic excitation source, where the excitation signal produces an acoustic signal by a substance, detecting the acoustic signal by a coherent phased array transducer separated by air from the human host, analyzing the detected acoustic signal by a signal processor, and outputting by the processor substance response information according to a scanning position and according to a temporal pulse width of the electromagnetic excitation signal.
[0007] According to one aspect of the invention, emitting the spatially scanning, temporally pulsed, electromagnetic excitation signal includes emitting a signal that can be microwave pulses, RF pulses, RF FM chirp pulses, FM electromagnetic signal, or CW electromagnetic signal.
[0008] In another aspect of the invention, emitting the spatially scanning, temporally pulsed, electromagnetic excitation signal includes scanning a frequency range, scanning multiple frequencies simultaneously, scanning multiple frequencies in a sequence, or performing a temporal scan.
[0009] In a further aspect of the invention, the acoustic signal includes a thermoacoustic signal. Here, the thermoacoustic signals are mechanical waves in a frequency range from 1 KHz to 100 MHz.
[0010] According to one aspect of the invention, the transducer can be a CMUT, acoustic-to-electric transducer, or piezoelectric transducer.
[0011] In yet another aspect of the invention, a sequence of pulses of the electromagnetic excitation is at a frequency in a range from 1 MHz to 100 GHz.
[0012] According to another aspect of the invention, the temporal pulse width of the electromagnetic excitation source is in a range from 1 ns to 100 ms.
[0013] In a further aspect of the invention, the temporal pulse width of the electromagnetic excitation source is in a range from 100 ms to 10 s.
[0014] In one aspect of the invention, the electromagnetic excitation includes using a steerable uniform gradient electromagnet, where an electromagnetic excitation signal including magnetic induction and Lorentz forces is used to produce the acoustic signal, where coherency between a TX (RF) induction pulse of the steerable uniform gradient electromagnet and a RX (US) of the acoustic signal enable use of frequency-modulated continuous wave signaling for localization of the substance.
[0015] In one aspect of the invention, emitting the spatially scanning, temporally pulsed, electromagnetic excitation signal includes controlling a phased array of the electromagnetic excitation source to focus the signal on specific regions of the human host.
[0016] In a further aspect of the invention, detecting the acoustic signal by the CMUT coherent phased array comprises detecting pressure resulting from temperature changes at the skin surface of the human host in a range from 100 μK to 10 K.
[0017] In another aspect of the invention, the electromagnetic excitation source includes an inductive loop, capacitive driver, or an antenna array.
[0018] According to a further aspect of the invention, the substance can include explosives, weapons, drugs, metals, plastics, or materials having geometric shapes foreign to the human host.
[0019] In yet another aspect of the invention, outputting by the processor substance response information includes reconstructing an image of the substance in real-time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 shows the use of multiple frequencies (in the electromagnetic range) resonant to that shape, size, or chemical properties of geometric shapes when looking for specific size or shape of embedded material, according to one embodiment of the invention.
[0021] FIG. 2 shows a schematic drawing of the detection system, according to one embodiment of the invention.
[0022] FIG. 3 shows the form of an RF pulse signal, according to one embodiment of the invention.
[0023] FIGS. 4 a - 4 b show how the beamforming algorithm operates when the RF-TX starts with the first zone in the host medium and progresses to other zones, according to one embodiment of the invention.
[0024] FIG. 5 shows the RF pulse width is modified in small steps to identify US frequencies at which the distance between the embedded object and the surface is resonant (multiple of half-wavelengths), according to one embodiment of the invention.
[0025] FIGS. 6 a - 6 c shows how the center frequency of the pulse is swept from pulse sequence to pulse sequence to identify any specific absorption windows or other effects that can cause resonant effects, according to one embodiment of the invention.
[0026] FIG. 7 shows an example implementation of one embodiment of the invention
[0027] FIG. 8 shows magneto-acoustic (MA) excitation and detection scheme, which can be combined with the previously described thermo-acoustic system in a single non-contact detection device, according to one embodiment of the invention.
[0028] FIGS. 9 a - 9 c shows how the RF carrier frequency will determine the absorption spectra, according to one embodiment of the invention.
[0029] FIG. 10 shows recent tests by the inventors use 2.14 GHz and yield following images for fat and muscle in oil, according to one embodiment of the invention.
DETAILED DESCRIPTION
[0030] The invention provides a method of detection, imaging, or screening, where anomalies in a host medium are sensed and distinguished from a distance or from close interactions. According to one embodiment, the invention includes electromagnetic energy that is transmitted or deposited into the medium, and from the differences detected in absorption characteristics of the host compared to the irregular or anomalous material hidden within the host the image is reconstructed. The current invention has applications in security imaging or medical diagnostics and screening.
[0031] In a further embodiment, the invention includes two or more parts. In the first part the device excites the medium using electromagnetic energy. This could be in the form of high-energy microwave pulses but is not limited to this as discussed below. The excitation can be at a single frequency or over a range of frequencies, where multiple frequencies can excite the medium simultaneously or in sequence. The resolution can be obtained by frequency-modulated pulses or through pulsed excitation. The second part of the current embodiment detects the resulting “effects” that arise due to the excitation of the first part. These effects include thermal (e.g. temperature differences), mechanical stress waves from a thermoacoustic effect, or scattering from differences in electromagnetic properties due to differences in dielectric constants. Multiple detection schemes could be used simultaneously, according to another embodiment. Detection or excitation can use multiple frequencies to provide spectroscopic information on the embedded object, according to a further embodiment. In yet another embodiment, multiple excitation schemes can also be integrated in a single device, where multiple parts of the system could be integrated in a single module.
[0032] In one embodiment the resulting mechanical stress waves emitted from the interface of the embedded substance and the host material are detected using ultrasound (US) detectors, where airborne or air-conducted US waves that initiate from inside the packaging and reach the surface to propagate in air are detected. The US detector can be placed directly on top of the medium or detect this airborne mechanical waves from a distance. One example of an application of this technique is the detection of chemical explosives embedded inside the human body. In this case the detection can be external and from a standoff distance. The detection frequency range for mechanical waves can be in any frequency range. For example, the detected mechanical waves could be from low 1 KHz to 100 MHz depending on specific applications, size of embedded anomaly, required resolution, distance to target among other reasons.
[0033] In a further embodiment of the current invention, a remote sensing imager for security detection is provided. In the current embodiment, the invention is used to screen for explosive chemicals or illicit drugs concealed inside the human body or adjacent to the body but underneath the clothing layers. In one example, pulses in the RF or microwave frequency range are transmitted from a distance and are used to excite human tissue and any internal irregularities such as explosives or hidden substances surgically placed inside the body. In this embodiment, the pulses from an electromagnetic transmitter can be in any part of the RF spectrum from low MHz to high GHz (millimeter-wave) depending on required penetration. The pulses are relatively large bursts of energy, and the pulse duration can be in the range of few nanoseconds to 10's of microseconds depending on various factors including the necessary resolution. To first order the correlation between the energy bandwidth of the bipolar wave and the RF pulse width is the inverse Fourier. For example, a pulse width of 1 us corresponds to most of energy being below ˜500 KHz. Depending on the frequency of operation of the transmitter, a phased-array system can be used to focus the energy to specific parts of the tissue or to sequentially scan through a volume. Absorption of electromagnetic energy is different for tissue and the internal hidden objects and therefore a temperature difference (in the order of mK to few K) will arise. The resulting stress waves due to the thermo-acoustic phenomenon are picked up using US detectors or US detector arrays that are placed at a distance from the body. The stress waves that originate from the boundaries propagate to the surface of the skin and are then picked up using high-sensitivity detectors. In another embodiment, the detector and the electromagnetic transmitter are placed on the surface of tissue or separated by known layers of clothing or other substances that could be used for impedance matching, such as US gel. The electromagnetic transmitter operates either in the near-field or the far-field. For near-field the possible excitation schemes include but are not limited to inductive loops or sources similar to what is used in MRI machines. Other forms of excitation include antenna arrays, a capacitive driver or near-field coupling schemes as alternative embodiments of this invention.
[0034] The transmitter and the US detector can be in a single device or two separate devices similar to bi-static radar. Multiple excitation sources or detection sensors could be placed around the medium. The current invention can be handheld and portable or implemented at a larger scale and non-portable. In other embodiments, the invention can be battery-operated or wall-powered, and could be used for inconspicuous detection and screening or for a security gate.
[0035] The current invention overcomes the challenges of non-contact detection in air-interface. In one embodiment, the invention uses multiple frequencies in US, a combination of frequencies, and a frequency sweep. Here, the invention is capable of changing the RF excitation pulse shape that includes changing the frequency, width, modulation, and other properties. This enables dynamic, programmable control over the excited US signal. From this, an US frequency sweep is generated to identify peak frequencies that result from internal resonances of the structure. For example, if the distance from the embedded package to skin is multiple of half-wavelengths of the US wavelength, then resonance occurs and a large signal on the skin can be observed. This requires a very fine sweep of the RF pulse width and hence the US frequency range, which is achievable with an Arbitrary Waveform Generation (AWG) at the RF transmitter. In one aspect of the current embodiment, a coherent phased array transducer, such as a CMUT array, picks up this frequency range and detects peaks and nulls to identify any abnormalities in the reflected signal, where detecting the acoustic signal by the CMUT coherent phased array includes detecting pressure resulting from temperature changes at the skin surface of the human host in a range from 100 μK to 10 K. According to other embodiments, the coherent phased array transducer can be an acoustic-to-electric transducer or a piezoelectric transducer.
[0036] In a further embodiment of the invention, thermoacoustic (TA) signaling excites the host and receives US signals based on differences in absorption. If an area of 1 m 3 is excited, then a much larger power level is needed than one exciting a smaller region. Therefore, a higher frequency (e.g. >5 GHz) is used, where the wavelength allows a smaller concentration volume (e.g. 0.1 m 3 ). A beamformer, such as a RF phased-array is used to go through the whole volume step by step, where a relatively higher power is concentrated in a smaller volume in each step and therefore a larger signal is obtained.
[0037] The application of RF beamforming for TA sensing via contact or non-contact is new. In a further embodiment, instead of having a large power amplifier, smaller transmitters/excitation elements that effectively perform spatial power combining are used. In a further embodiment, the RF and US beamformers are synchronized to achieve a faster scan and better SNR by coherent averaging.
[0038] In a further embodiment, RF frequency tuning is used to provide spectroscopic information, where frequency selectivity is used to detect chemical signatures, geometrical signatures, or metal boundaries. Control of the center frequency, pulse duration and any other modulation in RF in real-time, is programmable.
[0039] In one example of one embodiment of the current invention, assume material (A) has a certain absorption spectrum. The invention looks for this pattern using the microwave excitation. For example a nitride combination may have absorption in 3.1 GHz, 3.8 GHz and 4.3 GHz. The invention programs TX to “interrogate” with these frequencies that is excite with these frequencies and look at a response image. If a match is seen then that chemical is detected.
[0040] Regarding detection of geometric shapes, when looking for a specific size or shape of embedded material, multiple frequencies are used (see FIG. 1 ) that are resonant to that shape or size. For example, a 5 GHz signal is resonant with a “box” that is 6 cm on the side or multiples thereof. Frequency agility and programmability is an important aspect for all of these scenarios, where the current invention uses a frequency range to identify internal objects. Multiple elements are looked for simultaneously by looking at different signatures in real-time and for all images.
[0041] In another embodiment, a sequence of frequencies is used, where a frequency F 1 is applied and the system looks for a response. The system then applies frequency F 2 and looks for a response. The system continues this process over a frequency range then reconstructs an image using a synthetic signal processing approach.
[0042] Regarding amplitude-based frequency only detection, according to one embodiment, frequency chirp in magneto-acoustic (MA) detection is used for resolution with a wider pulse. Conventional MA uses pulsed based signaling to achieve localization and imaging, where imaging techniques need a “time-stamp” and the pulse is one way to achieve this. Because pulse excitation peak power has to be very large, the average power will suffer. The current invention uses frequency-modulated continuous wave (FMCW) signaling, where a chirp frequency from f 1 to f 2 in a pulse period T is used. Based on the excitation frequency and the received US wave the spatial distribution of the target(s) is reconstructed. In FMCW the transmit signal is mixed with the received signal to get the beat frequency to determine the range. In one embodiment, the transmit signal is beat against the received US signal where coherence between the two systems is assumed. In another embodiment this is accomplished through a sequence of CW signals in a stepped manner.
[0043] In TA there is no phase coherency between RF and US. The RF signal is too fast for tissue to respond in coherence with US, where RF is in the GHz range and US is in the MHz range. According to one aspect of the current invention, a shock wave out of the tissue results from any large change in deposited energy. In MA, phase coherency between RF and US is achievable since they can be at the same or close enough frequencies (e.g. MHz range).
[0044] According to one embodiment of the invention, Capacitive Micromachined Ultrasonic Transducers (CMUTs) are used for their superior efficiently in generating and receiving sound waves in air. The efficiency of CMUTs comes about from the fact that thin vibrating plates have mechanical impedance that is well matched to air, where when a large electric DC field is present in the gap of the capacitor, the electromechanical coupling coefficient of the transducer can be close to unity. Coupled to those advantages are the inherent benefits of using micro-electro-mechanical-systems (MEMS) technologies to implement these transducers. Other added benefits include process control, reliability, low cost, and the ability to integrate electronics with the devices.
[0045] According to one embodiment, arrays of CMUTs are used in US imaging in both one-dimensional and two-dimensional array configurations. Signals from multiple transducers are summed with proper delays to create images of scattering objects or multiple sources of sound by triangulation. According to one embodiment, the invention employs a system of multiple receiving transducers to enhance the signal to noise ratio and provide images of internal absorbers, and hence sources of US. The invention is able to detect US waves generated deep within the body using non-contact transducers outside the body without a coupling medium. According to one embodiment, pressures generated in the body experience a large acoustic impedance mismatch when passing through the body/air interface, resulting in a loss of approximately 65 dB. Hence, the receiving transducers and their associated electronics are provided to enable very low-noise performance.
[0046] According to the invention, the mechanical noise floor (P min ) for a transducer with an active area, A, can be calculated using: P min =√{square root over (4kTZ 0 /A)}, where k is the Boltzmann constant, T is the absolute temperature, and Z 0 is the characteristic impedance of the air medium. As an example, assuming a 2-mm diameter transducer, the minimum detectable pressure is 1.49 μPa/√Hz. For an airborne transducer at 100 kHz with a fractional bandwidth of 10%, the minimum detectable pressure would be 149 μPa. As a rule of thumb, a 1 mK temperature rise corresponds to 800 Pa of acoustic pressure in TA imaging. Considering only the loss through the body/air interface, which is the most significant loss mechanism, where US attenuation in air at 100 kHz is less than 2 dB/m for nominal conditions, the invention calculates a detected signal SNR of approximately 69 dB for only 1-mK temperature rise. An array-based detection system is employed to further enhance the SNR, and digital filtering is used for additional enhancement, according to one embodiment.
[0047] FIG. 2 shows a schematic drawing of the detection system, according to one embodiment of the invention. Here, the system includes an RF/microwave transmitter (RF-TX), an US receiver (US-RX), and signal processing/conditioning as well as control circuitry. Both the RF-TX as well as US-RX are designed to overcome the air boundary and operate without any contact with the host medium. The object to be detected is hidden inside an opaque, host medium, such as a human subject. For example, the object to be detected could be explosives, weapons, drugs, metals, plastics, and materials having geometric shapes foreign to the human host.
[0048] According to one aspect of the invention, the emitted signal can be microwave pulses, RF pulses, RF FM chirp pulses, FM electromagnetic signal, or CW electromagnetic signal. The emitted signal further can include scanning a frequency range, scanning multiple frequencies simultaneously, scanning multiple frequencies in a sequence, or performing a temporal scan, where the temporal pulse width of the electromagnetic excitation source is in a range from 1 ns to 100 ms, or as high as 10 s depending on the source. Further, a sequence of pulses of the electromagnetic excitation is at a frequency in a range from 1 MHz to 100 GHz.
[0049] Turning to an exemplary embodiment, the RF-TX includes multiple elements in the form of an array and starts by transmitting a modulated signal to the host medium. According to different embodiments, the array could be planar patch elements or an array of directive elements, such as horn or Vivaldi antennas. The signal is in the form of an RF pulse (see for example FIG. 3 ). The parameters of the RF signal are: PRI (pulse rep rate), f 0 (carrier freq), Δt (pulse width).
[0050] Each of the antenna elements includes a phase shifter and modulator to enable beamforming and array processing. Beamforming takes place with constraints on maximum field point/direction as well as a null direction that is specific zones having a large signal/clutter. Additionally, with a digital processing unit, simultaneous beams can also be generated to illuminate non-adjacent zones and thus speed up the measurement process.
[0051] In one embodiment, the beamforming algorithm operates when the RF-TX starts with the first zone in the host medium as shown in FIGS. 4 a - 4 c. The beam is concentrated towards zone 1 and all the energy from the TX elements is focused to zone 1 . If there are N elements in the transmitter array then the total power radiated will be N times larger. Additionally, the effective isotropically radiated power (EIRP) experiences an additional gain of N due to focusing and therefore the effective EIRP is boosted by N 2 . With larger N a better focusing is achievable. The focusing is primarily with far-field algorithms and takes the dispersion of tissue as well as impedance differences into account by pre-distorting the waveform as well as post-processing algorithms. In one aspect, the focusing algorithms could also use near-field techniques in which case additional phase and amplitude correction is provided. For example if the zones are in the near-field of the array, then some elements may be closer to the zone than others. In this instance, a first order 1/r correction term can to first order take care of this mismatch. For the case of propagation in the tissue an additional correction term of exp(−alpha. r) is used.
[0052] As shown in FIG. 3-FIG . 6 , once the RF-TX focuses on zone 1 a string of pulses with energy at frequency f 1 is transmitted to this zone. These pulses are interrogating zone 1 for any abnormal properties. Any difference in absorption rate at f 1 initiates thermo-acoustic response and acoustic shock waves that propagate to the surface of the host medium. At the air interface these acoustic waves experience a loss (typically in the order of 65 dB). The airborne US-RX array picks up these acoustic waves in air. The received signal is typically a broadband bipolar wave whose main energy bandwidth depends on the RF pulse width. After receiving M distinct US pulses at the receiver and performing appropriate signal conditioning which includes synchronized averaging and filtering, the RF-TX either moves to a new zone or interrogates the same zone with a different pulse. For example, the same zone could be interrogated with frequency f 2 which is higher or lower than f 1 ( FIG. 6 ). In this example, the microwave absorption rate that initiates the TA signal is a result of dielectric property differentials at f 2 rather than f 1 . This change in TX pulse property takes place due to the interrogation is at a different RF center frequency to observe variations in absorption properties, where this helps to identify specific resonant geometries or absorption windows in the host. Further, this change in TX pulse property that is due to a change in the RF pulse width modifies the frequency content of the US wave to be used to sweep the US frequency, for example to look for resonant acoustic effects.
[0053] In one exemplary implementation of the system the RF pulse width is modified in small steps to identify US frequencies at which the distance between the embedded object and the surface is resonant of multiple half-wavelengths, as shown in FIG. 5 . Keeping all other parameters constant only the pulse width is changed and the arrival time and strength of the acoustic wave is observed. This is an indicator of any resonant effect.
[0054] Detecting the arrival time and energy takes place with very high-resolution analog-to-digital converters (ADC) in the front-end in excess of 16 bits in resolution. It is important to emphasize that for each RF pulse width, M pulses are transmitted and the outputs are integrated and conditioned as previously described.
[0055] The RF-TX modifies pulse properties in real-time as detection is taking place. A feedback path between the transmitted and the receiver exists so that the US-RX data can be used to determine future changes in RF pulse properties ( FIG. 7 ). For example, if the detected signal shows a near-resonant behavior from the object, then the RF pulse widths will be stepped in fine increments to detect the exact resonant frequency. Initial steps can be selected from a random set.
[0056] This sequence is used to find optimal τ for each f i before moving to the next frequency. The choice of τ i progression depends on the feedback from the US-RX in each subset. All of this is repeated for zones 1 to zones N.
[0057] Once detection in zone 1 is concluded, the transmitter will focus on zone 2 and the procedure is repeated. Different zones are designed to have some overlap so that corrections could be done down the chain ( FIG. 4 b ). For example, if zone 1 and zone 2 have an overlap volume (called zone 1 - 2 ) then the received data from this zone from each of the steps can be compared and results used for post-processing. Any differences can be attributed to systematic errors, angle dependencies, or time variations. This mutual information can be used to correct for any systematic errors in the transceiver.
[0058] In another aspect of the invention, the center frequency of the pulse will be swept from pulse sequence to pulse sequence to identify any specific absorption windows or other effects that can cause resonant effects—this time in the RF domain ( FIGS. 6 a - 6 c ).
[0059] An example implementation of one embodiment of the invention is shown in FIG. 7 . This is only one example of the implementation, where other variations can be implemented. For example, the US receiver array can use phase-shifted and delay elements to perform beamforming. A digital array is shown in FIG. 7 .
[0060] A magneto-acoustic detection system is shown in FIG. 8 , where contact-free induction of RF current in the presence of a steerable static magnetic field, B 0 , or field Gradient G 0 is employed. Lorentz forces at conductivity interfaces excite ultrasound signals detected by an external phased array. In another aspect of the invention, magneto-acoustic (MA) excitation and TA detection are combined in a single device. For example, a single hardware unit performs simultaneous and jointly optimized MA and TA signaling to further enhance signal to noise ratio and detect embedded explosives. MA and TA methods look at completely different frequency properties (MHz vs GHz) and the combination will be used for detection. The MA system uses an FMCW approach as opposed to direct pulse techniques.
[0061] The method according to one embodiment excites the host medium as well as the substance, for example an explosive device, where there exists a differential between these two absorption intensities. Here, muscle or human tissue absorbs more RF than plastic explosive, for example. This difference will generate acoustic shock waves at the surfaces. The specific selection of these parameters is determined by the measurement conditions and various detection parameters involved. For example, the RF carrier frequency will determine the absorption spectra, as shown in FIGS. 9 a - 9 c.
[0062] These figures show that for Muscle vs Plastic, in a specific geometry simulated in this graph, using higher frequencies up to 10 GHz is better for contrast. If one is detecting Blood vs Muscle, then ˜1 Ghz is the best frequency. Further, the frequency depends on other parameters such as dimensions of the “explosive” and host due to standing waves. For other scenarios, the RF carrier frequency range lies between 0.1-10 GHz. For example, recent tests by the inventors use 2.14 GHz and yield following images for fat and muscle in oil, as shown in FIG. 10 . The pulse rep rate (PRF) determines average power once the peak power is known.
[0000] P avg =T pulse /T prf ×P peak .
[0063] According to one embodiment, P ave is maximized to the point where safety is a concern, where the invention stays below the specific absorption rate (SAR) of 1.8W/kg for the average number.
[0064] According to one example, for P peak =10 kW (effective out of the array), T pulse =1 us, T period (PRI)=1 ms, →P avg =10 W over all the exposed volume. In another example, P peak =100 W, T pulse =1 μs, T period =1 ms, then P avg =100 mW, which is considerably lower than safety limits. Thus the RF pulse width determines the US energy spectrum, where a current system by the inventors uses 10 ns-10 us range.
[0065] The system detects a very weak signal in air. According to one embodiment, SNR is increased by averaging. For example, if N times averaging is performed, the SNR is increased by square root of N times. Consequently, the transmitter and receiver need to be synchronized to make sure we are averaging the right signal.
[0066] The received signal is band-limited in the US range. A bandpass filter is applied to reduce the noise outside the signal band (see FIG. 7 ). An electromagnetic coupling exists between the transmitter and receiver, and a sampling oscillation of the receiver signal is generated, which can be reduced by filtering, according to one embodiment. In general, filtering will increase SNR. For example, a transducer with 1 MHz central frequency is a relatively narrow band, where its bandwidth is about 60%, and the signal received outside this band is noise and coupling.
[0067] In the simulation of FIG. 10 , polyamide is used as the plastic material and muscle as tissue. Their dielectric properties are shown in Table 1.
[0000]
TABLE 1
Relative
Bulk conductivity
Dielectric
permittivity
(S/m)
loss tangent
Polyamide
4.3
0
0.004
Muscle
52.058
2.142
0.2466
[0068] Plastic explosives imbedded in the body are difficult to detect using traditional methods based on metal detection, where it has low conductivity and permittivity. Consequently, it absorbs much lower energy than the tissue, such as muscle. This invention works for security detection but is not limited to the detection of plastic explosive only. Any material with low conductivity and permittivity works in the same principle.
[0069] There are two resonant mechanisms. The first is microwave induced resonant. For a 5 GHz microwave signal, its wavelength is 3e8/5e9=6 cm. If an object under detection happens to have geometry of 6 cm, the object will resonate with microwave. This is the case in the air. In the tissue, the wavelength will change, where the object with the geometry of microwave length will resonate. The exact number depends on the dielectric properties of the object under detection.
[0070] The second is acoustic resonant. If the distance of the object under detection and the surface of the body is an integer number of half wavelength, the acoustic wave will be resonant. A larger signal can be detected. This is not related to the dielectric properties of the materials directly.
[0071] The present invention has now been described in accordance with several exemplary embodiments, which are intended to be illustrative in all aspects, rather than restrictive. Thus, the present invention is capable of many variations in detailed implementation, which may be derived from the description contained herein by a person of ordinary skill in the art. For example the invention can be used in medical imaging, cancer screening, or urgent-care imaging. Further, the invention can combine magneto-acoustic with thermo-acoustic and regular microwave back-scatter to provide a multi-modality approach with data fusion from all the techniques previously described. Also, the invention can have one or more of the scan axes mechanical scan axes as opposed to electrical scan axes.
[0072] All such variations are considered to be within the scope and spirit of the present invention as defined by the following claims and their legal equivalents. | A method of detection of substances embedded in a human host is provided that includes emitting from a coherent beamforming electromagnetic excitation source a spatially scanning, temporally pulsed, electromagnetic excitation signal toward a human host separated by air from the electromagnetic excitation source, where the excitation signal produces an acoustic signal by a substance, detecting the acoustic signal by a CMUT coherent phased array separated by air from the human host, analyzing the detected acoustic signal by a signal processor, and outputting by the processor substance response information according to a scanning position and according to a temporal pulse width of the electromagnetic excitation signal. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to serging or overedge sewing machines, and more particularly to an apparatus for serging a trouser-fly piece along an arcuate line of stitching and a contiguous substantially straight line of stitching extending along one of its longitudinal edges.
2. Prior Art
A known serging apparatus is schematically illustrated in FIGS. 6-8 inclusive of the accompanying drawings and generally designated at 100, which apparatus essentially comprises a serging unit 101 including a sewing needle 102 for forming an overedge or serge stitching S (FIGS. 7 and 8) and a feed dog 103 disposed in a table (not shown) beneath the needle 102 and cooperative with a presser foot (not shown) to advance a trouser-fly piece F through the serging unit 101, and a trimming cutter 104 disposed immediately upstream of the serging unit 101 for trimming a corner of a leading end Fa of the trouser-fly piece F. The apparatus 100 further includes an elongated guide member 105 having a guide surface 106 extending at an angle relative to a straight line L defining the path of movement of the trouser-fly piece F and extending in alignment with the needle 102 and adapted to guide the trouser-fly piece F into the serging unit 101. Designated at 107 is a fly-piece end sensor disposed diagonally to the upstream left of the sewing needle 102 for sensing the leading end Fa of the trouser-fly piece F being advanced into the serging unit 101. Upon sensing of the leading end Fa, the end sensor 107 sends an electrical signal to a controller (not shown) to start operation of the serging unit 101 not immediately but with a predetermined time lag corresponding to the length of time required for the leading end Fa of the trouser-fly piece F to arrive at the sewing needle 102 from the position of the end sensor 107. The end sensor 107 is adapted also to sense a trailing end Fa of the trouser-fly piece F and send a signal to the controller to discontinue operation of the serging unit 101 not immediately but with a certain time lag for the aforesaid reasons. Designated at 108 is a presser member generally in the form of a ball vertically movable toward and away from the trouser-fly piece F on the table by means of for example an electromagnet. Designated at 109 is a fly piece side edge sensor disposed diagonally to the upstream right of the sewing needle 102 for sensing a longitudinal side edge Fc of the trouser-fly piece F opposite to and remote from the guide member 105 and operatively associated with the controller of the serging unit 101 in such a manner that when the edge sensor 109 senses the presence of the trouser-fly piece F, the presser member 108 is held lifted in a standby position away from the trouser-fly piece F, and when the edge sensor 109 senses the absence of the trouser-fly piece F (when the trouser-fly piece F shifts off to the left of the edge sensor 109 for some reason during the serging operation), the edge sensor 109 sends a signal to the controller to lower the presser member 108 onto and press the trouser-fly piece F, whereupon the trouser-fly piece F is caused to turn about the presser member 108 counterclockwise under the influence of rotational moment produced upon advancement of the trouser-fly piece F by coaction of the feed dog 103 and the presser foot. With this rotational movement of the trouser-fly piece F, the trimming cutter 104 severs the trouser-fly piece F substantially arcuately along its leading end portion, followed by the serging of that portion as shown in FIG. 7. Thereafter, the trouser-fly piece F is oriented to move substantially in parallel with the straight path L of movement and is serged along its straight longitudinal edge until the end sensor 107 senses the trailing end Fb of the trouser-fly piece F and sends a signal to discontinue operation of the serging unit 101.
The foregoing prior art apparatus has a drawback in that since the serging unit 101 is arranged to start operation with a certain time lag upon issuance of the signal from the fly piece end sensor 107, the trouser-fly piece F can be serged from its leading end Fa (as indicated at the solid-line position in FIG. 6) if it is fed fast enough, but if it is fed too slow, the trouser-fly piece F is apt to receive the serge stitching from an end portion departing from the leading end Fa as illustrated by phantom-line in FIG. 6, with the results that there are produced trouser-fly pieces F having irregularly or otherwise defectively finished arcuate serges.
The prior art apparatus has a further drawback in that if the trouser-fly piece F is swerved or displaced from the position of the edge sensor 109 during its advancement along the straight path L after the arcuate or curved serging has been completed, the presser member 108 comes into pressure engagement with the trouser-fly piece F and causes the latter to turn counterclockwise, resulting in a trouser-fly piece F being serged objectionably arcuately along its longitudinal straight side edge Fc as indicated at Fe in FIG. 8.
SUMMARY OF THE INVENTION
With the foregoing drawbacks of the prior art in view, the present invention seeks to provide an apparatus for automatically serging a trouser-fly piece initially along an arcuate line of stitching extending across its leading end while tracing and trimming that arcuate line in advance of serging and thereafter continuing to serge along a straight line of stitching extending parallel to one longitudinal substantially straight side edge of the trouser-fly piece.
The present invention further seeks to provide a trouser-fly piece serging apparatus which incorporates control means for controlling the serging operation so that a trouser-fly piece can be serged initially arcuately at its leading end portion and subsequently linearly along its one longitudinal side edge with utmost accuracy and efficiency to provide uniformly finished serges on the trouser-fly piece.
According to the invention there is provided a trouser fly piece serging apparatus which comprises: a serging unit defining a serging station and including means for advancing an elongate rectangular trouser fly piece longitudinally through the serging station and a sewing needle for serging a substantially arcuate end portion and subsequently a substantially straight longitudinal side edge of the trouser-fly piece with a serge stitching during advancing movement of the trouser-fly piece; a trimming cutter disposed immediately upstream of the serging station and operative in synchronism with the serging unit for trimming, in advance of serging by the needle the trouser-fly piece along the substantially arcuate trimming line and subsequently along the substantially straight longitudinal side edge; a guide member disposed upstream of the serging station and having a guide surface extending at such an angle relative to a path of advancement of the trouser-fly piece that the guide surface and the path of advancement of the trouser-fly piece converge toward the serging station for guiding the trouser-fly piece into the serging station so that the trimming cutter assumes a position to conform to a curvature of the arcuate trimming line; a presser means disposed upstream of the serging station for causing the trouser-fly piece to turn in a direction to separate the trouser-fly piece from the guide surface until the trouser-fly piece is oriented to move parallel to a straight line of path of advancement extending linearly in alignment with the needle; a trouser-fly piece end sensor disposed upstream of the serging station for sensing both the leading end and a trailing end of the trouser-fly piece; a trouser-fly piece edge sensor disposed upstream of the serging station for sensing a longitudinal side edge of the trouser-fly piece and issuing an electrical signal to actuate the presser means; and a start-up sensor disposed in close proximity to and upstream of the trimming cutter for sensing the leading end of the trouser-fly piece being advanced into the serging station and issuing an electrical signal to start operation of the serging unit.
The above and other objects and features of the invention will become better understood from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a main portion of an apparatus for serging a trouser-fly piece according to the invention;
FIG. 2 is a schematic plan view utilized to illustrate the general geometric relationship between a trouser-fly piece and various operating members of the apparatus;
FIG. 3 is a time chart utilized to explain the time sequence of operation of the various operating members of the apparatus;
FIG. 4 is a plan view of a trouser-fly piece shown serged in timed relation to the time chart of FIG. 3;
FIG. 5 is a plan view of the trouser-fly piece after it is finished by the apparatus of the invention;
FIG. 6 is a view similar to FIG. 2 but showing a prior art counter part;
FIG. 7 is a schematic plan view showing a trouser-fly piece being serged along its longitudinal side edge on the prior art apparatus;
FIG. 8 is a plan view of the trouser-fly piece after it is finished by the prior art apparatus; and
FIG. 9 is a schematic diagram of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described hereinbelow in detail with reference to a preferred embodiment shown in the accompanying drawings.
As shown in FIG. 1, a trouser-fly piece serging apparatus 10 according to the present invention includes a serging unit 11 defining a serging station 12 for serging one longitudinal edge of a trouser-fly piece F as the trouser-fly piece F is advanced through the serging station 12 along a longitudinal path, a trimming cutter 13 for trimming an arcuate longitudinal end portion of the trouser-fly piece F to be serged, and a trouser-fly piece guide member 14 disposed upstream of the serging station 12 for guiding a trouser-fly piece F as it is supplied to and advanced through the serging station 12. The serging unit 11, the trimming cutter 13 and the guide member 14 are disposed on a table 15.
The serging unit 11 is a conventional serging machine which is actuated by a suitable drive such as a motor and which includes a serge stitch forming mechanism having a sewing needle 16 for forming an overedge or serge stitching S (FIGS. 4 and 5) on one longitudinal edge of a trouser-fly piece F. The serging unit 11 further includes a feed dog 17 (FIG. 2) disposed in the table 15 beneath the needle 16. The feed dog 17 cooperates with a presser foot 18 (FIG. 1) to advance the trouser-fly piece F through the serging station 12 in timed relation to the operation of the serge stitch forming mechanism. A further description as regards other component parts of the serge stitch forming mechanism is omitted as they constitute no positive part of the invention.
The trimming cutter 13 is disposed immediately upstream of the serging station 12 for trimming a corner of a leading end Fa of the trouser-fly piece F being advanced into the serging station 12. The trimming cutter 13 may be arranged to trim the trouser-fly piece F along one longitudinal side edge Fc additional to the trimming of the corner. The trimming cutter 13 is vertically reciprocated by a suitable drive means (not shown) in synchronism with the reciprocating movement of the needle 16.
A presser member 19 is provided with a ball 20 disposed close to and upstream of the serging unit 11 and vertically movable toward and away from the table 15 for forcing a portion of the trouser-fly piece F against the table 15 to cause the trouser-fly piece F to turn in one or counterclockwise direction about the same portion, as described later. The ball 20 is attached to one end of a resilient plate member 21 whose opposite end is connected to a support block 22 which is in turn connected to a piston rod (not shown) extending from a fluid-operated cylinder 23. Actuation of the cylinder 23 urges the ball 20 toward and away from the trouser-fly piece F on the table 15 in a manner hereinafter described.
The guide member 14 in the form of an elongate rectangular block includes a guide surface 14a extending at an angle relative to the path of advancement of the trouser-fly piece F being advanced by the serge unit 11, more specifically at such an angle that the guide surface 14a and the path of advancement of the trouser-fly piece F converge toward the serging station 12, for guiding the trouser-fly piece F into the serge station 12 so that the trimming cutter 13 assumes a position to conform to a curvature of a substantially arcuate trimming line Fy along which the trouser-fly piece F is trimmed and simultaneously serged.
The guide surface 14a of the guide member 14 guides a straight longitudinal edge Fd (FIG. 2) of the trouser-fly piece F which is opposite to the other longitudinal side edge Fc adapted to be serged. An inner corner of the leading end of the guide member 14 is beveled to form an auxiliary guide surface 14b extending parallel to a straight line L (FIG. 2) defining the path of movement of the trouser-fly piece F and extending linearly in alignment with the needle 16. The auxiliary guide surface 14b and the guide surface 14a of the first guide member 14 jointly define a corner 14c which serves as a fulcrum about which the trouser-fly piece F turns when it is advanced for the formation of the trimmed arcuate corner of the trouser-fly piece F and the serge stitching S on the trimmed arcuate corner.
Designated at 24 is a trouser-fly piece end and sensor such as a photosensitive cell disposed below the table 15 in alignment with a light source 25. The end sensor 24 is located diagonally to the upstream left of the needle 16 and adapted to sense both the leading end Fa and the trailing end Fb of the trouser-fly piece F being advanced into the serging station 12.
A trouser-fly piece side edge sensor 26 similar to the end sensor is disposed diagonally to the upstream right of the needle 16 for sensing a longitudinal side edge Fc of the trouser-fly piece F opposite to and remote from the guide member 14. The edge sensor 26 is electrically connected to a controller C (shown in FIG. 9) for the serging unit 11, the arrangement being that when the edge sensor 26 senses the presence of the trouser-fly piece F, the presser member 19 is held lifted in a standby position away from the trouser-fly piece F, and when the edge sensor 26 senses the absence of the trouser-fly piece F (when the trouser-fly piece F shifts off to the left of the edge sensor 26 for some reason during the serging operation), the edge sensor 26 sends a signal to the controller to actuate the cylinder 23 to lower the presser member 19 onto and press the trouser-fly piece F, whereupon the trouser-fly piece F is caused to turn about the presser member 19 counterclockwise under the influence of rotational moment produced upon advancement of the trouser-fly piece F by coaction of the feed dog 17 and the presser foot 18. In other words, the trouser-fly piece F is caused to turn in a direction to separate from the guide surface 14a of the guide member 14. With this rotational movement of the trouser-fly piece F, the trimming cutter 13 severs the trouser-fly piece F substantially arcuately along its leading end portion, followed by the serging of that portion as shown in FIG. 4.
Thus, actuation of the cylinder 23 is substantially concurrent with the "on" and "off" condition of the edge sensor 26 which repeats as depicted in FIG. 3 until the serging of the trouser-fly piece F along its arcuate or curved end portion Fx is completed.
According to an important feature of the invention, there, is provided a start-up sensor 27 disposed in close proximity to and diagonally to the upstream right of the trimming cutter 13 and the serging unit 11 and adapted to sense the leading end Fa of the trouser-fly piece F being advanced into the serging station 12 as shown in FIGS. 1 and 2.
Upon sensing of the leading end Fa, the start-up sensor 27 sends an electrical signal to the controller C of the serge stitch forming mechanism to start a motor (not shown) to actuate the serging unit 11 and the trimming cutter 13 in synchronism with each other. The cutter 13 thus actuated trims the trouser-fly piece F along the arcuate or curved end portion Fx, while at the same time, the serging unit 11 forms an overedge or serge stitching S (FIG. 4) on the arcuate portion Fx.
The controller includes a control counter DC (shown in FIG. 9) for setting the number of cycles of vertical reciprocation or strokes of the sewing needle 16 which is required to complete the serging of the entire arcuate portion Fx of the trouser-fly piece F. A typical preset number of strokes of the needle 16 set in the control counter is thirty (30) as in the present embodiment, though dependent upon the size of a trouser-fly piece F to be processed. When the number of counted strokes of the needle 16 is equal to the preset value, the control counter energizes a relay to put the edge sensor 26 in "of" condition or out of service so that the ball 20 of the presser member 19 is kept lifted in a standby position away from the trouser-fly piece F to prevent the latter from continuing rotational movement.
The controller further includes a delay counter DC (shown in FIG. 9) for setting the number of cycles of vertical reciprocation or strokes of the needle 16 which is required to continue operation of the serging unit 11 for a certain period of time (as indicated by N in FIG. 3) after the end sensor 24 has sensed the trailing end Fb of the trouser-fly piece F in order to effect serging fully up to the trailing end Fb. This is because the end sensor 24 is spaced a distance from the serging station 12. A typical preset number of strokes of the needle 16 set in the delay counter is ten (10) as in the present embodiment, which is however dependent upon the distance between the end sensor 24 and the serging unit 11, more specifically the needle 16. When the number of counted strokes of the needle 16 is equal to the preset value, the delay counter energizes a relay to stop the operation of the serging unit 11.
The control counter and the delay counter may be replaced by respective timers to perform the intended functions.
Operation of the trouser-fly piece serging apparatus 10 of the foregoing construction will be described below with reference to the time chart of FIG. 3 and the schematic diagram of FIG. 9.
A trouser-fly piece F to be processed on the apparatus 10, as shown in FIG. 4, has an elongate rectangular shape. A slide fastener stringer Z including a pair of stringer tapes T with respective rows of coupling elements E mounted on the inner longitudinal edges thereof is sewn to the trouser-fly piece F by a pair of straight lines of stitches (not designated). The trouser-fly piece serging apparatus 10 of the invention can be of course used with a trouser-fly piece F devoid of a slide fastener stringer Z.
As shown in FIG. 1, an elongate rectangular trouser-fly piece F is disposed flatwise on the table 15 and then manually guided longitudinally along the guide surface 14a of the guide member 14 with the leading end Fa facing toward the serging station 12. The trouser-fly piece F guided by the guide surface 14a extends along an inclined path extending at an angle relative to the path L of movement of the trouser-fly piece F being advanced by the serging unit 11.
Time point P 1 in the time chart of FIG. 3 represents a standby position in which all of the operating members of the apparatus 10 are held inoperative. Then, the trouser-fly piece F is advanced longitudinally along the guide surface 14a in the direction indicated by the arrow Y in FIG. 2 until the leading end Fa of the trouser-fly piece F is sensed by the end sensor 24 as indicated by time point P 2 in the time chart. At this time point, however, the end sensor 24 is arranged to remain inoperative pending arrival of the leading end Fa of the trouser fly piece F at the start-up sensor 27.
Time point P 3 represents arrival of the leading end Fa at the edge sensor 26, in which instance however the edge sensor 26 still remains inoperative. A further advancement of the trouser-fly piece F brings its leading end Fa into contact with the start-up sensor 27 as indicated by time point P 4 , whereupon the start-up sensor 27 sends an electrical signal to the controller to start the serging unit drive or motor, thus the operation of the serging unit 11.
Designated at t 1 between time points P 4 and P 5 is a time delay provided as by a timer for allowing the operator to check if the trouser-fly piece F is properly set with respect to the serging unit 11. With actuation of the drive for the serging unit 11 at time point P 5 , the trimming cutter 13 starts trimming a corner of the leading end Fa of the trouser-fly piece F along the substantially arcuate trimming line Fy (FIG. 4) and substantially at the same time, the serging unit 11 starts forming an overedge or serge stitching S (FIG. 4) on the arcuate end portion Fx of the trouser-fly piece F. With the serging unit 11 thus in operation, the edge sensor 27 is put in operative condition so that it monitors the presence ("off") and the absence ("on") of the trouser-fly piece F and sends a signal to the controller to actuate the cylinder 23 to lower or raise the presser ball 20, as the case may be, during the serging of the arcuate end portion Fx of the trouser-fly piece F over a period of time P 7 between time point P 5 and time point P 8 , during which time the control counter counts the number of strokes of the needle 16. Designated at t 2 is a normal time delay (from P 5 to P 6 ) peculiar to an electric control system. Upon completion (time point P 8 ) of the serging of the arcuate end portion Fx of the trouser-fly piece F as dictated by the control counter, the edge sensor 27 and hence the cylinder 23 operatively associated therewith are put in "off" condition; namely, out of service and need not continue operation unless a situation arises to the contrary, because the trouser-fly piece F after being arcuately serged is guided automatically by coaction of the feed dog 17 and the presser foot 18 to move substantially linearly along the straight path L of movement. The trouser-fly piece F thus continues advancement through the serging station 12 along the straight path L, during which time the longitudinal side edge Fc of the trouser-fly piece F is serged over a period of time spanning between time points P 8 and P 9 .
A further advancement of the trouser-fly piece F causes the trailing end Fb to arrive at the position of the end sensor 24 (time point P 9 ), whereupon the end sensor 24 issues a signal to the controller to start the delay counter. The straight serging operation further continues until the number of strokes of the needle 16 counted by the delay counter is equal to the preset value (ten strokes) corresponding to a time duration N of from time point P 9 to time point P 10 as indicated in the time chart of FIG. 3. The trouser-fly piece F is completely serged with the stitching S over the full length thereof. Subsequently, the delay counter issues a signal to stop operation of the serging unit 11. Thus, a trouser-fly piece F with its arcuate end portion Fx and straight longitudinal side edge Fc serged with the serge stitching S is produced as shown in FIG. 5. Then, the next trouser-fly piece is supplied to the guide member 14 and the foregoing sequences of steps of operation is repeated. | An apparatus is disclosed for automatically serging a trouser-fly piece initially along an arcuate line of stitching extending across its leading end while tracing and trimming that arcuate line in advance of serging and thereafter continuing to serge along a straight line of stitching extending parallel to one longitudinal substantially straight side edge of the trouser-fly piece. The apparatus incorporates control means including a control counter and a delay counter both operatively associated with the operation of a sewing needle so as to ensure serging of the trouser-fly piece over its full length with accurate and uniform finishing. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/320,269, filed Jun. 13, 2003.
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention generally relates to the general field of rocketry, orbital transfers and satellite station-keeping, as well as space vessel attitude control. More particularly, this invention relates to an apparatus and method for maneuvering objects in low and zero-gravity environments using electromagnetic forces.
2. Description of the Related Art
The current state of the art in orbital transfers and station keeping involve reaction rockets using a variety of fuels, either chemical or electrostatic acceleration. Chemically-fueled rockets require that fuel be brought along, and this limits the performance of the rocket through the rocket equation.
Δ V=I sp ·g ·ln( M o /M f )
where ΔV is the velocity change given the specific impulse of the rocket motor (I sp ), the gravitational constant (g), and the logarithm of the ratio of weights before (M o ) and after (M f ) the burn.
It would be desirable if alternative techniques were available to stop, slow, and divert objects in low-gravity (orbital) and zero-gravity environments.
SUMMARY OF INVENTION
The present invention provides an apparatus and method that make use of electromagnetic energy to maneuver an object, such as stop, slow, and/or divert a vessel or projectile, in low and zero-gravity environments. The apparatus comprises means for generating a magnetic field in the zero or low-gravity environment, and an object capable of electromagnetically interacting with the magnetic field so that the object's speed and/or trajectory is altered when moving in proximity to the generating means. As such, the method of this invention entails maneuvering an object in a zero or low-gravity environment by generating a magnetic field in the zero or low-gravity environment, and then moving the object in proximity to the magnetic field and sufficiently close to the generating means such that the magnetic field alters the trajectory and/or speed of the object.
A significant advantage of this invention is that maneuvering of an object can be exclusively performed using electromagnetic forces, which offer numerous advantages over chemically-fueled and electrostatically-accelerated rockets. The invention achieves efficient orbital injection and ejection without the need for chemical rockets, and can be adapted to use inexhaustible solar energy and/or harvest energy from decelerating/deflecting objects. The invention is adapted to perform either or both of two general classes of orbital maneuver, namely, altering the speed or trajectory of an object. The first class encompasses catching (decelerating) and launching (accelerating) objects, while the second involves deflecting an object, such as forcing an object into or out of an orbital path. In combination, the invention provides a general purpose orbital transfer system and method. For example, a payload launched from the Moon can be deflected into a geosynchronous orbit around the Earth, and then ejected from orbit and accelerated back to the Moon. Fine control over the electromagnetic forces employed in these maneuvers is possible through control circuitry with feedback sensors, such that objects can be delivered, captured and placed in orbit with precision.
Other objects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 schematically represents a plurality of orbiting deceleration coils aligned along the path of a payload in accordance with an embodiment of this invention.
FIG. 2 demonstrates an inductive deceleration operation performed with a magnetic field in accordance with an embodiment of the invention.
FIG. 3 depicts a tangential capture scheme that can be performed with one or more magnetic fields generated in accordance with FIG. 2 .
FIG. 4 represents an apparatus for performing any one of the operations depicted in FIGS. 1 through 3 .
FIGS. 5 and 6 represent energy conversion and storage during capturing of a payload and acceleration of a payload using the stored energy in accordance with a preferred aspect of the invention.
FIGS. 7 and 8 demonstrate deflection operations that can be performed with multiple magnetic fields in accordance with the invention.
FIG. 9 depicts a capture scheme that can be performed in accordance with the embodiments of FIGS. 7 and 8 .
FIGS. 10 and 11 schematically represent a control system for performing a payload deflection operations.
FIGS. 12 and 13 represent a deflection operation that can be performed with electric fields in accordance with another embodiment of the invention.
DETAILED DESCRIPTION
General concepts of the invention can be described in reference to FIG. 1 , which depicts three orbiting conductive rings or coils 10 aligned in a substantially straight line along the trajectory 12 of a traveling object, which may be a canister, projectile, vessel, etc., hereafter simply referred to as a payload 14 . The coils 10 are represented as being generally annular-shaped, though other shapes are possible. The term “coil” is used herein as any structure capable of producing a magnetic field, and may be a single loop or a winding of multiple concentric loops, as will be evident from the Figures. The magnetic fields produced by the coils 10 are generated with the intent to exert an electromagnetic force on the moving payload 14 . The payload 14 is adapted to electromagnetically interact with the magnetic fields, and therefore is formed to contain a ferrous material, hold a static charge, or contain an electromagnet, e.g., superconducting or electric with control circuitry and some form of energy storage device, such as a capacitor or battery. As the payload 14 passes through or near each coil 10 , the electromotive force (emf), or Lorentz force, applies a force to the payload 14 . More particularly, the coils 10 as arranged in FIG. 1 apply a deceleration force to the payload 14 . In an alternative embodiment that will be described in reference to FIGS. 7 and 8 , the payload 14 travels past the coils 10 (instead of through them), causing the trajectory 12 of the payload 14 to be bent along the radius of a circle or spiral for the purpose of diverting the payload 14 from or into an orbit. In either case, a plurality of coils 10 is believed to be generally desirable to spread the forces across a larger period of time, to spare the payload 14 , and reduce design constraints on the size, accuracy and power needed in the coils 10 .
The process of altering the orbit of a high-velocity projectile requires precise control and accurate sensing capabilities. Sophisticated control electronics 16 is therefore an important aspect of the invention, including the use of sensors for sensing position, velocity, and magnetic fields. The control electronics 16 is preferably coupled to the other components of the system either rigidly, through flexible connections, or wirelessly as may be demanded by design considerations. Because navigation and station-keeping are important, each coil 10 is also preferably provided with station-keeping and attitude control devices 18 to apply optimal velocity and timing to correctly adjust the velocity of the payload 14 .
When the payload 14 enters the magnetic field generated by one of the coils 10 , a back-emf pulse is generated that is aligned with the linear direction of the trajectory 12 of the payload 14 . As will be discussed in reference to FIGS. 5 and 6 , this energy back into the system (Lenz's law) can be captured and stored in a variety of ways. For example, the stored energy can be used to reduce the power requirements for the entire system, and also used as a means to provide propulsive thrust to the payload 14 . In this way, the same coils 10 can be used for acceleration as well as deceleration, which in combination with the ability to deflect the payload 14 enables fine control of orbital transfer.
In view of the above, an arrangement of components is preferably employed to yield an apparatus capable of directing the momentum of a traveling body, such as the payload 14 of FIG. 1 . The following discussion is based on the usage of such an apparatus in orbit, and certain specific advantages follow from this. However, the same principles could be used in nearly any environment. Also as discussed above, two operational embodiments of the invention will be discussed, with the principle acting component of each embodiment comprising one or more magnetic fields generated by, for example, coils capable of sustaining a large electric current and suitably configured to create a magnetic field. According to the first operational embodiment depicted in FIG. 1 and described in greater detail in FIGS. 2 and 3 , the payload 14 passes through the central (axial) openings 20 of one or more coils 10 . By fabricating the payload 14 to contain one or more ferrous materials (such as iron or iron-rich minerals like magnetite), the coil current in the coil 10 can be adjusted to impart a force on the payload 14 that slows the payload 14 . Such an embodiment is a linear approach to the invention, operates along substantially straight lines, and may require one or more coils 10 . According to the second operational embodiment described in reference to FIGS. 7 through 9 , the payload 14 is passed across the openings 20 of the coils 10 . As it passes, the payload 14 is pulled toward the coil 10 or pushed away from the coil 10 , causing its trajectory 12 to be bent. Through the use of several such coils 10 judiciously spaced along the intended trajectory 12 , the speeding payload 14 can be coaxed to a new, more desirable orbit. Each of these approaches will be described and then their application described. A discussion of various alternative implementations and applications will build upon these foundations.
The first operational approach, which makes use of what is referred to herein as an inductive deceleration (ID) apparatus 22 , is depicted in FIG. 2 with continued reference to the coil 10 and payload 14 originally discussed in reference to FIG. 1 . It is a well-known principle of the physics of electromagnetism that a current through a coil produces a magnetic field. The lines of force of a magnetic field generated by the coil 10 in this manner are depicted in dashed lines in FIG. 2 . Similar to the principles of an electric solenoid, when the payload 14 (or another magnetic material) enters the magnetic field, a force is applied to the payload 14 . The magnitude of the force is determined by the current, the number of winds, the area of the coil 10 , and a number of secondary factors. The magnitude of the magnetic field force is derived from a calculation including the mass of the payload 14 and its starting and desired velocity vectors. The goal of the ID apparatus 22 is to modify the velocity of the payload 14 . Depending on design considerations and economics, a single coil 10 might be preferable, or it may be that an apparatus 22 comprising a series of individual coils 10 is optimum.
Another alternative for payload design is to use a conventional electromagnet in the form of one or more coils of an electrically-conductive material. Electric energy can be stored and possibly harvested en route by solar cells until contact is made with the ID apparatus 22 . The charge would be driven through the coils, generating a momentary magnetic field that provides greater stopping power for a given magnetic field. This method would require communications and a more expensive payload 14 than merely iron, but could be operated at higher speeds, which may be desirable under certain conditions.
Another alternative for payload design is to use a conventional electromagnet in the form of a coil 10 of an electrically-conductive material. Electric energy can be stored and possibly harvested en route by solar cells until contact is made with the ID apparatus 22 . The charge would be driven through the coils 10 , generating a momentary magnetic field that provides greater stopping power for a given magnetic field. This method would require communications and a more expensive payload 14 than merely iron, but could be operated at higher speeds, which may be desirable under certain conditions.
Because it utilizes a linear technique, the ID apparatus 22 of FIG. 2 is ideally suited for orbital transfers arriving on a tangent. In fact, the ability to set up a tangential trajectory makes inductive deceleration ideally suited for low time-of-travel operations. To illustrate inductive deceleration in the embodiment of this invention, FIG. 3 depicts a payload launched from the Moon 24 by some means (perhaps chemical or electromagnetic, such as a mass-driver or rail-gun) and targeted at the ID apparatus 22 in a geosynchronous Earth orbit (GEO) 26 , a preferred spot for many satellite applications. The launch velocity from the Moon 24 must first exceed the lunar escape velocity, typically at a much higher speed because the orbital velocity of GEO is approximately 3.2 times that of lunar orbital velocity. This is determined through the satellite equation:
v 2 =GM/r
where G is the gravitational constant, M is the mass of the Earth, and r and v are the radius and velocity, respectively, of the orbit of a satellite. When a payload is launched from the Moon 24 towards GEO 26 , its velocity relative to Earth's center will be the sum of the Moon's velocity and its own launch velocity. If the launch is aimed and timed properly, the trajectory 12 can be placed so that it very nearly lines up on a tangent to the GEO 26 , as depicted in FIG. 3 . The arrows in FIG. 3 show the approximate trajectory 12 of the payload as seen from the Solar System north over a fixed Earth center. The length of each arrow indicates the speed of the projectile vector at that location. The angle and speed of the launch from the Moon 24 was chosen so that upon arrival at GEO 26 , the velocity vector is nearly perfectly on a tangent with GEO 26 . The ID apparatus 22 , acting linearly as described above, is in position to absorb the excess velocity of the payload's motion. The coil 10 (or coils 10 ) are positioned and designed such that the payload's new velocity would be identical to the geosynchronous orbit, effectively coming to rest from the perspective of an object already in GEO 26 .
There is a certain amount of momentum transfer between the payload 14 and the coils 10 as the payload is slowed. In other words, the act of slowing the payload 14 will tug the apparatus 22 in the direction of the payload's velocity vector. Important design considerations include the mass-power tradeoff in the design of the coil 10 and its power source, and also the tradeoff between high inertia and rapid return-to-station attitude adjustment. FIG. 4 shows one possible configuration for a coil assemblage 28 for the ID apparatus 22 , including a coil 10 (comprising a number of conductive windings), a controller box 30 (which may also include communications and energy storage), antennae 32 for communications, station-keeper thrusters 34 to maintain a desired orbit and attitude, and solar panels 36 to provide electrical power. Connections can be rigid, flexible, or wireless as needed to optimize overall system performance.
Alignment of the payload 14 and the coil 10 of the assemblage 28 is of critical importance. This alignment is facilitated by accurate aiming of the launched payload 14 or accurate determination of its trajectory 12 after launch. If the payload 14 does not have a magnetic field of its own, the current state-of-the-art in orbital mechanics can predict the trajectory of the payload 14 from, for example, the Moon to, for example, GEO. However, even with fine control over the launch together with precision measurements of the trajectory 12 , there may be other forces that cause a deviation from an ideal trajectory. For that reason, the ID apparatus 22 preferably has the capability to propitiously position each of its coil assemblages 28 with respect to the incoming payload 14 .
The coils 10 and coil assemblages 28 shown in FIGS. 1 through 4 must be aligned properly with the approaching payload to maximize the effectiveness of the desired velocity modification. This will, in general, involve motion about six degrees of freedom: linear translation in three dimensions and rotational motions in three dimensions. In addition to proper attitude positioning, it may also be desirable for the coils 10 to have a velocity relative to the desired orbit. This additional velocity, which might be provided by the station-keeper thrusters 26 shown in FIG. 4 or by separate thrusters (not shown), reduces the requirements for electric currents and provides greater flexibility to optimize system performance based on relative capabilities of the apparatus” components. A generalized control system for the entire system is depicted in FIGS. 10 and 11 , which will be discussed below.
As previously noted, a back-emf pulse is induced in the coil 10 as the ferrous or magnetic-containing payload 14 passes through its magnetic field. This reverse power can be captured, or harvested, through appropriate power circuitry and conditioned for an appropriate use. One such use is to charge up a capacitor, a battery, or other known storage mechanism for electrical energy. This power can be reserved until the arrival of another payload and used to generate the forward current, thereby easing the power demands of the overall system and minimizing the amount of momentum change experienced by the coil assemblage 28 . To illustrate, FIG. 5 shows the moment in time when the payload 14 passes through the center of the opening 20 of the coil 10 . The graph indicates current flow (I) through the coil 10 over time, showing first the steady-state current needed for the deceleration field. Next, a reverse current spike appears due to the back-emf induced at the arrival of the payload 14 , as depicted in FIG. 5 . Thereafter, a drop-off or decay of current occurs as the magnetic field has completed its work and is shut down. FIG. 5 shows how this excess current can be captured, for example by using a level-shifted diode or high-pass filter, and then saved in an electrical energy storage unit 38 , such as one or more capacitors, batteries, superconducting electromagnets, etc.
A second use for the back-emf power surge is to power certain high-voltage devices that might do useful work for the apparatus 22 . Some examples might be to fire the station-keeper thrusters 34 or attitude-positioning thrusters (not shown) to immediately help restore a desirable speed and altitude after the encounter with the moving payload 14 . Other uses might include driving pumped lasers, which could be applied to do useful work on the apparatus 22 .
FIG. 6 represents usage of the harvested back-emf power to accelerate the payload 14 (or an empty container) to perform station-keeping, perform inter-orbital transfers, etc. For this purpose, the stored charge, possibly augmented by solar power absorbed by the solar panels 36 shown in FIG. 4 , is used to initiate a magnetic field that imparts a force to the payload 14 . This might be accomplished either by reversing the current direction, which would be convenient but not necessarily simple, or by simply turning the coil assemblage 28 around and restarting the current in a forward direction. With this capability, an installation of the coil assemblage 28 using ID technology would facilitate a local distribution center where high-speed payloads are slowed and then delivered around the GEO trace, a fertile land in the desert of space 185,000 miles long.
With further reference to FIGS. 7 through 11 , magnetic fields placed along a curved path can be employed to modify the velocity vector of the payload 14 , for example, to deflect a payload launched from the Moon into a geosynchronous orbit as represented by FIG. 9 . The principles of such a velocity modification are represented in FIG. 7 , which shows an apparatus 40 comprising a first coil 10 generating a magnetic field at an approximately right angle to the incoming trajectory 12 of the payload 14 . With this configuration, the trajectory 12 of the payload 14 can be bent or turned to a more desirable direction. The payload 14 passes across the opening 20 of the first coil 10 , oriented so that its magnetic field pulls the payload 14 toward the coil 10 so as to change the trajectory 12 of the payload 14 . Anticipating this effect, a second coil 10 is favorably positioned so that it further bends the payload trajectory 12 . By using a sufficiently large individual coil 10 or an appropriate number of smaller coils 10 , an incoming payload 14 can be shifted through a turn of any desired amount. As evident from FIG. 7 , the axes of the coils 10 are aligned as radii of a circle, the trajectory 12 lies along the radially-outward ends of the coils 10 , and the magnetic fields of the coils 10 pull the payload 14 toward the coils 10 . Alternatively, the trajectory 12 could lie along the radially-inward side of the coils 10 , such that the magnetic fields cooperate to push the payload 14 away from the coils 10 . FIG. 8 represents deflecting a payload 14 through a rotation to not only align the payload 14 with a desired orbit, but to also draw kinetic energy from the payload 14 and thereby reduce its speed. Instead of being aligned in a circular arrangement, the axes of the coils 10 could be aligned as radii of a spiral. Such a configuration is represented in FIG. 8 , which shows the payload trajectory 12 as being bent through 450 degrees with six coils 10 . It is foreseeable that any number of coils 10 could be employed to bend the trajectory of a payload through essentially any curvilinear path.
With further reference to FIGS. 7 through 11 , magnetic fields placed along a curved path can be employed to modify the velocity vector of the payload 14 , for example, to deflect a payload launched from the Moon into a geosynchronous orbit as represented by FIG. 9 . The principles of such a velocity modification are represented in FIG. 7 , which shows an apparatus 40 comprising a first coil 10 generating a magnetic field at an approximately right angle to the incoming trajectory 12 of the payload 14 . With this configuration, the trajectory 12 of the payload 14 can be bent or turned to a more desirable direction. The payload 14 passes across the opening 20 of the first coil 10 , oriented so that its magnetic field pulls the payload 14 toward the coil 10 so as to change the trajectory 12 of the payload 14 . Anticipating this effect, a second coil 10 is favorably positioned so that it further bends the payload trajectory 12 . By using a sufficiently large individual coil 10 or an appropriate number of smaller coils 10 , an incoming payload 14 can be shifted through a turn of any desired amount. As evident from FIG. 7 , the axes of the coils 10 are aligned as radii of a circle, the trajectory 12 lies along the radially-outward ends of the coils 10 , and the magnetic fields of the coils 10 pull the payload 14 toward the coils 10 . Alternatively, the trajectory 12 could lie along the radially-inward side of the coils 10 , such that the magnetic fields cooperate to push the payload 14 away from the coils 10 . For example, FIG. 8 represents deflecting a payload 14 through a rotation to not only align the payload 14 with a desired orbit, but to also draw kinetic energy from the payload 14 and thereby reduce its speed. Instead of being aligned in a circular arrangement, the axes of the coils 10 could be aligned as radii of a spiral. Such a configuration is represented in FIG. 8 , which shows the payload trajectory 12 as being bent through 450 degrees with six coils 10 . It is foreseeable that any number of coils 10 could be employed to bend the trajectory of a payload through essentially any curvilinear path.
Various types of payloads 14 can be maneuvered in the manners represented in the Figures. By configuring the payload 14 to hold a static electric charge, its trajectory 12 is bent through the Lorentz force
F=qvXB
where v is the velocity vector of the charged body, B is the magnetic field tensor, and X is the cross product operator that acts at right angles to two vectors: the electric charge q and the vector with the direction of the force F. Using the Lorentz force on a charged payload, or similarly by using just magnetic force on a ferrous or electromagnetic payload, the direction of the payload's trajectory 12 can be altered with relatively small amounts of kinetic energy change. This can be used to great advantage in a certain configuration of orbital transfer. For example, consider again the Moon launch scenario of FIG. 3 and an alternative scenario depicted in FIG. 9 . In the latter scenario, a payload launcher on the Moon 24 has aimed the payload 14 such that the payload 14 arrives at some angle to a desired orbit, here depicted as the GEO 26 . In this case, orbital transfer involves redirecting the trajectory 12 of the payload 14 to align with GEO 26 . As depicted in FIG. 9 , the launch from the Moon 24 is realigned to GEO 26 with, for example, an apparatus 40 of the type depicted in FIGS. 7 and 8 , whose coils (not shown) induce a significant bend in the velocity vector arrow 12 just prior to encountering GEO 26 . This capture scheme can be extended in the general case to nearly any angle. This configuration is very energy efficient, as there is very little wasted energy. By setting the Moon launch velocity equal to, or slightly greater than, the orbital velocity at GEO, bending the trajectory with the Lorentz velocity deflection technique as represented in FIG. 9 can be used to bring a payload 14 into precise geosynchronous orbit. This capture scheme, though represented as occurring at ninety degrees, can be greater or less than ninety degrees by a sizeable amount. However, for simplicity of visualization and distinction from the scheme represented in FIG. 3 , the scheme represented in FIG. 9 can be generally considered a perpendicular arrival of the payload 14 at the target orbit, and then a right-angle bend to adjust the trajectory 12 .
FIGS. 10 and 11 schematically depict a control system 42 and components for performing payload deflection with an apparatus 40 of the type represented in FIGS. 7 through 9 . Together, the control system 42 and components preferably provide a wireless control system and feedback loop for minimizing errors and for on-the-fly modifications and/or adjustments to accommodate individual payload differences in momentum, velocity, and even material properties. Considering for simplicity a single coil 10 , a payload velocity and position sensor 44 is positioned along and near the intended trajectory 12 of the payload 14 and a coil field sensor 46 is positioned near the coil 10 to provide instant feedback for control circuits 48 of the control system 42 . The control circuits 48 make minor adjustments to the attitude control of the coil 10 , or the current profile through the coil 10 , or the position of a subsequent coil (not shown), as may be appropriate. Information 50 from the launch can be used to preposition the coil 10 , sensors 44 and 46 , and other equipment and preset the control parameters to nominal values. However, through rapid processing, further fine-tuning adjustments can be made dynamically and possibly in real-time, thereby increasing the control over the final trajectory 12 .
While embodiments of the present invention described herein include examples of payload catchers and general orbital transfers, the principles of the invention can be applied to further applications, making the invention a versatile and important space technology. For example, through the use of multiple coils 10 or coil assemblages 28 , acceleration and deceleration forces can be minimized, making this technology suitable for human transportation. A series of such coils 10 (or coil assemblages 28 ) could be used to accelerate and decelerate many types of payloads, vessels, vehicles, and other cargo. Energy efficiency is enhanced by the ability to store electrical power, and versatility is provided by the current control and attitude thrusters. Thus, a collection of these apparatuses could be used to distribute a wide range of traffic throughout a large region of space. Both payload cargo or manned vessels could be processed using the same equipment. Inter-orbital transfers with modest delta-v requirements could be handled exclusively through electromagnetic acceleration and deceleration. A given installation could even be modified, merely by repositioning the apparatus, to operate either in the ID configuration ( FIGS. 1 through 3 ) or Lorentz force configuration ( FIGS. 7 through 10 ).
The rapidity with which the coils 10 can be readied for a subsequent payload operation is dependent upon many factors, such as the available storage capacity and the power-generating capability of solar cells, plus the efficiency by which kinetic energy of motion is transferred to electrical energy and vice versa. As represented in the Figures, a multitude of configurations are envisioned for the coils 10 , e.g., a linear arrangement where a payload is accelerated and decelerated along a substantially linear line, or a collection of coils in a spiral with the intent of reducing and re-directing the velocity of a payload. A combination of linear and circular motion might also be used to provide certain advantages not realized with either configuration alone.
The coil configurations represented in the Figures depict only one of several geometries of wire that give rise to a magnetic field suitable for carrying out the invention. Even a single loop, whether circular, oval, or in the shape of a polygon generates a magnetic field. Simple coils are an especially efficient way to increase the magnetic field for a given current, though it may be found advantageous to vary the area of the coils along their length. For example, a tapered cylinder (conical section) might provide good performance in bringing a moving projectile quickly and accurately to a specific point of zero relative velocity.
In view of the above, the present invention provides apparatuses and methods for altering the velocity and/or trajectory of an object carrying an electric charge, an adjustable or permanent magnetic field, or a magnetizable material (such as iron) in zero or low-gravity environments. The coils that perform these functions can be arrayed in a linear or a curvilinear fashion, and operated inductively or using Lorentz forces, depending on the desired performance requirements. In the general case, an apparatus in accordance with the invention may have an alternating or repeating operating pattern in which both linear deceleration and path deflection are performed, so that speed can be reduced and velocity direction redirected as desired. Control circuitry, guided by suitable sensors, can be used to adjust and adapt the attitude and current profiles of the coils to optimally modify the desired final velocity of a payload. Energy stored that may be gained from a previous capture or deflection can be supplemented with solar cell power to provide the coil current needed to capture or deflect the next object. These coils can be used within a large range of power levels to decelerate, redirect and even accelerate objects, making this a general purpose orbital transfer technology superior in many ways to rocketry. Advantages in efficiency, control, flexible design, and low-maintenance operation make this invention highly desirable for use in a thriving cislunar economy and a foundation for transportation and commerce in outer space.
While the invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. Therefore, the scope of the invention is to be limited only by the following claims. | An apparatus and method that make use of electromagnetic energy to maneuver an object, such as stop, slow, and/or divert a vessel or projectile in low and zero-gravity environments. The apparatus comprises an element capable of generating a magnetic field in the zero or low-gravity environment, and an object capable of electromagnetically interacting with the magnetic field so that the object's speed and/or trajectory is altered when moving in proximity to the magnetic-field generating element. As such, the method entails maneuvering an object in a zero or low-gravity environment by generating a magnetic field in the zero or low-gravity environment, and then moving the object in proximity to the magnetic field such that the magnetic field alters the trajectory and/or speed of the object. | 1 |
FIELD OF THE INVENTION
The present invention relates to firearms, and more particularly to safety devices incorporated into firearms.
BACKGROUND OF THE INVENTION
Safety has always been a principle concern of firearm manufacturers and owners alike. Because of this concern, there has been over the years much attention directed towards incorporating safety devices into firearm designs. These safety devices have been of various types and of various particular designs. Most any gun enthusiast is familiar with the various mechanical safeties incorporated into firearms. Besides the various mechanical safeties, it has been known to utilize a non-firing cartridge or slug within certain portions of the firearm itself. For example, see the disclosure found in U.S. Pat. No. 4,776,123.
But generally, firearm safety devices of the prior art have been of the type that can be readily seen or are obvious to a person having the firearm in his hands. Expressed in another way, conventional safety devices can be turned on and off by the flick of a finger. Even with slugs or dummy cartridges, they are most often designed to be placed in the firearm in an obvious and conspicuous position allowing for the safety (whether mechanical or of the slug type) made inoperative by an inquisitive and probing child, for example.
While it is true that conventional mechanical firearm safeties and even conventional slug type safeties do have utility, there are certain situations where they are not effective. In this regard, it should be noted that in recent years there have been a rash of gun shop robberies that have been accompanied by the gun shop operator or custodian being murdered. Ironically in these cases, the gun shop operator is fatally injured with a gun that he or she is demonstrating to whom he or she thinks is a potential customer. Because of the frequency of gun shop robberies and associated shootings involving the very firearm being shown, there is a need to provide a safe weapons system that will protect gun shop owners and operators while they are showing various firearms within the shop.
Therefore, there has been and continues to be a need for a firearm safety device that does not have the drawbacks and shortcomings of conventional and mechanical safeties and which is particularly designed to assume a hidden and non-conspicuous position within the firearm itself.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention entails a firearm safety device that is intended to overcome the drawbacks and shortcomings of prior firearm safety devices, and which can be manufactured and sold relatively inexpensively.
The present invention provides for a safety device in the form of a non-fireable slug that is designed to assume a hidden position within the firing chamber of a particular firearm. Once in this hidden position, it is practically impossible for the firearm to be chambered. Thus, the device of the present invention is in fact a safe weapons system.
In particular, the present invention entails a non-firing slug that is particularly designed to be compatible with a wide number of particular firearms. The non-fireable slug is designed to seat within the firing chamber, intermediately between the opposed ends within the firing chamber. When seated, the slug assumes a position generally hidden from view such that the firearm in all respects looks conventional and normal. But because of the particular position of the slug within the firing chamber, the firearm cannot be loaded with a live ammunition round.
It is therefore an object of the present invention to provide a safe weapons system for a firearm that is practical, effective, and economical.
A further object of the present invention entails the provision of an insert type safe weapons system for a firearm that when inserted into the firearm and positioned in an operative mode cannot be readily detected by an observer or one holding the firearm.
Still a further object of the present invention resides in the provision of a safe weapons system of the character referred to above that permits a relatively few different sized slugs to fit a wide range of different types and size firearms, thereby making the insert safety device extremely economical and practical.
Another object of the present invention resides in the provision of an insert type safety device for a firearm that is provided with means for readily dislodging the slug from the firing chamber such that the firearm can be quickly made operative.
It is also an object of the present invention to provide an insert slug type safety device that is designed to be totally compatible with the firearm itself and which is particularly designed such that the safety slug will not scar or otherwise damage the firearm and particularly the firing chamber thereof.
Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the slug forming a part of the safe weapons system of the present invention.
FIG. 1A is a perspective view of the slug in the form of a tapered cylindrical sleeve.
FIG. 2 is a perspective view of a pistol showing the insertion of the slug into a firing chamber.
FIG. 3 is a fragmentary perspective view of a shotgun in an open position illustrating the position occupied by an appropriate shotgun shell when that shell engages the slug of the present invention.
FIG. 4 is a perspective fragmentary view of the firing chambers of a conventional shotgun showing the slug in a seized position within one of the firing chambers.
FIG. 5 is a fragmentary perspective view of a firearm firing chamber with portions broken away to illustrate the slug of the present invention and a slug removal tool utilized to dislodge the slug from the firing chamber.
DETAILED DESCRIPTION OF THE INVENTION
With further reference to the drawings, the safe weapons system of the present invention is shown therein and includes a non-fireable slug indicated generally by the numeral 10. As will be more fully understood from subsequent portions of this disclosure, the non-fireable slug 10 is designed to be accepted and secured within a firing chamber of a firearm.
Referring to the slug 10, it is seen that the same is elongated and includes an aft end portion 12 and a fore end portion 14. Formed in the fore end portion 14 is a locator cavity 16.
As seen in the drawings, slug 10 includes a cylindrical wall structure 18. The cylindrical wall 18 is very slightly tapered inwardly from the aft end 12 towards the fore end 14. As for the degree of taper, it is contemplated that the slug 10 would be tapered approximately 0.005 inches per inch of length.
As noted above, slug 10 is designed to be received and accepted within a firing chamber of various type firearms including pistols, shotguns, etc. As seen in the drawings, for purposes of illustration, a pistol is shown in FIG. 2 while a shotgun is depicted in FIG. 3.
In any event, the firearm includes at least one firing chamber that is indicated by the numeral 20. Each firing chamber includes an inlet end 20a, an outlet end 20b and a tapered inner cylindrical wall 20c.
In FIG. 2, there is illustrated a pistol indicated generally by the numeral 40. Pistol 40 includes a conventional revolving cylinder 42. Cylinder 42 is provided with a series of circumferentially spaced firing chambers 20. A portion of the outer structure around one firing chamber is removed to better illustrate the firing chamber and the relationship of slug 10 seized therein. Because the inner cylindrical wall 20c is tapered and because of the corresponding taper of the slug 10, it is seen that the slug assumes a secured or seized position within the firing chamber 20 intermediately between the inlet end 20a and the outlet end 20b. As seen in FIG. 2, there is an open space defined between the aft end 12 of the slug 10 and the inlet end 20a of the firing chamber 20. This space prevents the particular firing chamber from being chambered with a conventional live ammunition round. In essence, the space defined between the inlet end 20a and the aft end of slug 10 is insufficient to accommodate the conventional live ammunition round made for that particular firearm. Put in another way, if a conventional live ammunition round is attempted to be inserted within the firing chamber that contains the slug 10 then a rear portion of the live ammunition round will project out the inlet end of the firing chamber to such a degree that the pistol cylinder 42 cannot be closed.
Now turning to FIGS. 3 and 4, there is shown therein a double-barrel shotgun indicated generally by the numeral 44. Shotgun 44 includes a pair of elongated barrels 46. Each of the barrels includes its own firing chamber 20 that in conventional fashion forms an extension of the barrels.
As was the case with pistol 40 described herein above, slug 10 is designed to be seized within the firing chambers 20 of the shotgun 44. In FIG. 4, there is an illustration showing slug 10 seized within the right hand firing chamber. In the left hand firing chamber there is also a slug 10, but it is not specifically shown. But the presence of the slug 10 in the left hand chamber prevents a conventional shotgun shell or cartridge 48 from being properly chambered in that firing chamber. Note in FIG. 4 that the presence of the slug 10 within the left hand firing chamber prevents shell 48 from being pushed or moved further into the firing chamber 20. Again, the open space defined between the aft end portion 12 of the slug 10 and the inlet 20a of the firing chamber 20 is insufficient to accept the appropriate size ammunition round for that particular firearm.
In FIG. 3, there is a like illustration, but with the illustration showing a shell 48 that cannot be fully pushed or move into the right hand firing chamber 20 because of the presence of a slug (not shown) being properly seized within that same firing chamber. It is noted in FIG. 3 that when the shell 48 engages the slug in the firing chamber that the rear portion of the shell 48 projects rearwardly to such a degree that the shotgun 44 cannot be closed.
Now turning to FIG. 5, there is shown therein a slug removal tool indicated generally by the numeral 22. The slug removal tool 22 includes a guide or leading section 24 that includes a forwardly projecting locator dome 26. Locator dome 26 is designed to mate with the concave cavity 16 formed in the fore portion of the slug 10. Extending from the rear side of guide 24 is a threaded shaft 28 that is designed to be secured within the remote end of a conventional cleaning rod 30.
It is appreciated that to dislodge slug 10 from a seized position within the firing chamber 20, that the cleaning rod 30 can be extended into and through the outlet end 20c of the firing chamber 20 to where the locator dome 26 engages the concave cavity 16 of the slug. Thereafter, by applying pressure against the slug 10, one can dislodge the same from the firing chamber 20 and remove the slug 10 through the inlet end 20a of the firing chamber 20.
A very important advantage of the slug design disclosed herein lies in the fact that a slug can be designed in size such that it will fit a large number of firing chambers for different firearms. Thus, this enables one to produce a few different sized slugs but yet accommodate a wide range of firearms. More particular, the diameter and taper of the slug is designed to correspond to the diameter and taper of the ammunition specifically designed for a number of particular weapons. The length of the slug 10 is not designed to correspond to the length of the appropriate ammunition. The length of a slug will be based on the length of the shortest live ammunition round designed for the specified group of firearms. For example, the case diameter and taper is essentially the same for a .38 Special, .357 Magnum, and .357 Maximum. But the length of these three rounds varies substantially. Because the .38 Special is the shortest in length, the length of the slug is determined in accordance with the length of the round for the .38 Special. In particular, in the design of the present invention, the slug 10 is made a length approximately two-thirds of the total length of the shortest round having the same general diameter and taper. This enables the slug to appropriately fit within any firing chamber designed to accept this group of ammunition rounds.
In this regard, it should be pointed out that there are many different calibers that fall within the same case family. There are many commercial cartridges that were developed from what is known as a parent cartridge. For example the .243 Winchester was originally derived from the .308 Winchester which was derived from the .30/06 Springfield. The .25/06 Remington, .270 Winchester, .280 Remington, 7 mm Express and 8 mm/06 Wildcat were all derived from the .30/06 Springfield which is knows as the parent cartridge. In the case of the present invention, the length of the slug 10 is based on the shortest cartridge of the case family. Again the length of the slug 10 is designed to be approximately two-thirds of the length of the shortest cartridge for a particular cartridge family. It is noted that the length is based on the length from the base of the cartridge to the cartridge shoulder.
The slug 10 can be made of various materials and can be formed in numerous designs. For example, it is contemplated that the slug 10 could be a tapered cylindric sleeve. A tapered cylindrical sleeve is shown in FIG. 1A. In this case, the slug would be less visible because one would be able to see through the firing chamber and the slug itself. As far as the construction and composition of the slug 10 goes, it is contemplated that it would be comprised of a plastic or relative hard rubber material that would be compatible with the firing chamber itself such that it would not scar, scratch or otherwise damage the firing chamber.
From the foregoing specification and discussion, it is appreciated that the present invention entails a very reliable dependable, and relatively simple safe weapons system for a firearm. The slug of the present invention is designed to assume a position within the firing chamber of a firearm such that that firing chamber cannot be appropriately chambered with a conventional ammunition round. The present invention is especially practical and has substantial utility inasmuch as a single slug can be designed and sized such that it will be compatible with a wide range of different firearms. Consequently, two or three different size slugs can be designed which will fit and accommodate a large number of firearms.
The present invention, may of course, be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. | The present invention entails a safe weapons system for a firearm. In particular, the safety system of the present invention comprises a non-fireable slug specifically designed to be received and accepted within a firing chamber forming a part of the firearm. The non-fireable slug includes an outer cylindrical tapered wall that is generally tapered to conform to the taper of the firing chamber itself and the slug is specifically sized such that it is designed to assume to seized or secured position within the firing chamber intermediately between opposed end portions of the firing chamber. Safety is realized because of the position occupied by the slug within the firing chamber. The position occupied by the slug within the firing chamber makes it practically impossible for the firearm to be chambered with a live ammunition round. | 5 |
BACKGROUND OF THE INVENTION
In the knitting of one-piece panty hose it is conventional to form the waist opening during the knitting operation as described, for example, in U.S. Pat. No. 3,673,821 to Johnson. In most instances the waist opening is defined by a cut or slit extending wale-wise along the knitted fabric, that is in the direction of knitting. This is objectionable because in the finished product the dimension between the waist opening and the crotch is limited by the diameter of the knitting machine, which is conventionally about 4 or 41/2 inches.
There have been prior attempts to form the waist opening during knitting on a circular knitting machine in a direction transverse to the direction of knitting or course-wise of the knitted article, but considerable difficulties have been encountered in preventing breakdown of the stitches bordering the waist opening.
SUMMARY OF THE INVENTION
According to the invention, the waist opening is formed by first clearing all needles from the stitches throughout a portion of the arc of needles to form a first transverse edge or lip. Subsequently, a plurality of partial courses are formed longitudinally of the panty hose, the ends of said partial courses being sheared at the edge of said waist opening to form a pair of spaced longitudinal lips or edges. Finally the yarn is reintroduced to the needles throughout the entire needle cylinder to form a second transverse edge and resume knitting after the generally rectangular waist opening has been formed. The fabric in an edge zone surrounding the top, bottom and sides of the transverse opening comprise courses having an added elastic yarn. The portions of such edge zones immediately adjacent the lips or edges of the opening provide the fabric with tuck stitches that hold well and offer high elasticity and a tendancy to roll up along the opening edges or rims. In the edge zones, preferably, a course of stitches with an elastic yarn and a non-elastic yarn is formed alternately with a course of stitches having only non-elastic yarn or yarns.
The retained or tuck stitches in the portions of the edge zone immediately adjacent the lips or edges of the opening are preferably formed by a 1:1 needle selection in selected courses which provides a retained stitch alternated with plain or conventional stitch in such courses.
In the portions of the edge zone adjacent the ends of the transverse lips and at the ends of the partial courses adjacent the longitudinal lips are preferably reinforced by introducing a supplementary yarn which is added into alternate courses in which the elastic yarn is not present. This reinforced fabric with the supplementary reinforcing yarn may have adjacent the lips of the opening an interlaced knitting effect such as that obtained by the 1:1 technique, while in the development of the remainder of the edge zone at the side edges of the opening a plain stitch technique is used.
The distances between the top and bottom edges of the rectangular opening are, of course, determined by the number of partial courses therebetween, which may be varied depending on the size or other requirements of the article to be knit.
The invention also relates to the article formed by the above-defined method.
The invention will be better understood following an understanding of the description and accompanying drawings, which illustrate a practicle embodiment of the invention.
In the drawings:
FIG. 1 is schematically illustrative of the development of the body portion of the panty hose in accordance with the present invention;
FIG. 2 is a schematic view illustrating the positioning of the incoming yarn and needle arrangement at two consecutive feeds in the transverse edge zones above and below the transversely extending edges of the waist opening;
FIG. 3 is a pictorial stitch diagram illustrating the fabric formed from the set-up of FIG. 2;
FIG. 4 is a schematic view illustrating the positioning of the incoming yarn and needle arrangement at two consecutive yarn feeds in an area adjacent the upper and lower lips of the waist opening of the panty hose;
FIG. 5 is a pictorial stitch diagram illustrating the fabric formed in the zone of FIG. 4;
FIG. 5A is a geometrical representation of the stitches of the FIG. 5 stitch diagram;
FIG. 6 is a schematic view illustrating the positioning of the incoming yarn and needle arrangement at two consecutive feeds for forming the fabric adjacent the side edges of the opening and the upper and lower edges of the opening near the end thereof;
FIG. 7 is a pictorial stitch diagram illustrating the fabric formed from the set-up of FIG. 6;
FIG. 7A is a geometrical representation of the stitches or the FIG. 7 stitch diagram;
FIG. 8 is a schematic view illustrating the positioning of the incoming yarn and needle arrangement in the longitudinal edge zone adjacent the side edges of the waist opening;
FIG. 9 is a pictorial stitch diagram of the fabric in the zone defined by FIG. 8; and
FIG. 10 is a pictorial stitch diagram illustrating a local enlarged portion of the typical zones surrounding the waist opening;
FIG. 10A is a geometrical representation of the stitches of the FIG. 10 stitch diagram.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to FIG. 1 of the drawings, a length 1 of the panty hose is formed before or prior to the opening 3 with the knitting operation proceeding in the direction f 1 . The waist opening 3 is then formed as described hereinafter, whereupon a second length 5 of the fabric is formed subsequently.
The opening 3 is defined by a first transversely extending edge or lip 7 which is formed by clearing a first arcuate section of needles in the needle cylinder from the stitches immediately preceding the lip 7. This is accomplished conventionally by raising and subsequently relowering the needles of the arcuate section without seizing yarn to form a new loop. Such needle selection is well known in the art and reference is made to U.S. Pat. No. 3,811,296 and British Patent 1,362,211 which show conventional means for needle selection and yarn feed. A pair of longitudinal edges or lips 9 are then formed by a plurality of partial courses which are formed by the needles of the cylinder which were not cleared to form edge 7, hereinafter called the "needles of the conjugate or explementary arc." As the needle cylinder revolves continuously, and knitting of the partial courses occurs, the side edges of the opening are formed by shearing the yarns in each course at the ends of the needles of the conjugate or explementary arc. The shearing may be performed by any of several conventional systems. The second lip 11, opposite lip 7 is begun in a conventional manner immediately after the forming of the partial courses which define the longitudinal edges or lips 9, and with the same needles of the first arc of needles from which were previously released the stitches along the edge 7. The knitting of the first course of edge 11 is begun with preferably a 1:1 needle selection to form the tucked stitches, although all needles could be restarted in the initial course.
Around the edges or lips 7,9, and 11 of opening 3, different zones 16, 24, 26, 28, 36, and 38 of fabric are formed with respect to the fabric of the tubular article 1,5 to constitute a finishing edge around openings 3, said edge being preferably of an elastic type. In particular, along lines 12,14, the insertion and disengagement of auxiliary yarns takes place to form said finishing edge. During the knitting of the article in the area of opening 3, the insertion and disengagement of auxiliary yarns is effected by raising selected needles along a prescribed arc in such a manner as to pick up an auxiliary yarn only in the zones in which that yarn is intended to be knit.
As the panty hose is formed in the direction of arrow f 1 , a first outer edge zone 16 of fabric is formed as shown in FIGS. 3 and 10. An additional elastic yarn 18 is fed to alternating feeds in such a manner that the fabric in zone 16 includes a first course with the yarn 20 (feed A2 in FIG. 2) and a second course alternating therewith formed both by the yarn 22 and by an elastic yarn 18 (feed A1 in FIG. 2). The yarn 18 is seized by needles raised in a conventional manner up to needle path 19A. In the zones where the elastic yarn 18 is not to be seized, the needles are raised only to needle path 19B to pick up only yarn 22.
After the forming of zone 16, a second edge zone 24 is formed immediately adjacent lip 7. The fabric in zone 24 is modified in the structure to be more elastic, with an increased tendency to roll up and with a tendency to resist raveling or breakdown of the stitches. Toward this end (See FIGS. 4, 5 and 10) in said portion 24, feed A1 directs the plain or non-elastic yarn 22A and the elastic yarn 18A in the same manner as illustrated in FIG. 2 with the path of the needles along the trajectory 19A. The exclusion of the elastic yarn 18A during knitting of the remainder of a cylinder rotation is accomplished by lifting the needles only to the lower trajectory or needle path 19B.
The difference between zone 24 and zone 16 occurs at the second feed A2 (FIG. 4) wherein a non-elastic yarn 20A is introduced in the alternate course in alternating wales by means of a 1:1 needle selection in such a manner as to constitute the interlacing pattern shown in the lower portion of the fabric in FIGS. 5 and 10. This interlacing pattern is formed in a prescribed number of courses which is greater than that shown in FIG. 5, however for the purposes of drawing clarity, only two courses are shown and these are distorted to be representative of their resultant geometry from the contraction of an elastic yarn. FIGS. 5A and 10A show a geometrical representation of the stitches wherein K is the knit stitch (two yarns), k is the knit stitch (one yarn) and T is the tuck stitch. FIG. 7A is a similar geometric representation for the distorted showing of the loops in FIG. 7. The fabric structure thus formed in portion 24 provides increased elasticity of the fabric and a desired tendency to roll up along the edge or lip 7. The rolling tendency forms on one hand a finishing of said lip and on the other hand a protection against the raveling or break-down of the stitches cast off along the edge or lip 7.
The partial courses of fabric extending between edges 7 and 11 are formed as described hereinafter.
Once knitting is resumed after opening 3 is formed along edge 11, a zone 26 is formed similar to zone 24. Subsequently another outer edge zone 28 is formed similar to zone 16, whereupon the knitting of the fabric is continued to form the rest of the tubular leg 5.
Adjacent the end portions of edges 7 and 11 of the opening 3, a reinforced fabric is formed to better withstand the stresses which occur during use. In the portion between line 14 and the two marking lines 30 illustrated in FIGS. 1 and 10, a supplementary, preferably non-elastic yarn 32 is introduced (See FIGS. 6 through 9) at the same feed A2 where yarn 20B is introduced. Yarn 20B is the same as and corresponds with yarns 20, 20A in zones 16,24. Similarly, 18B corresponds with 18 and 18A and 22B corresponds with 22 and 22A. Feed A1 still introduces the non-elastic yarn 22B and the elastic yarn 18B as in zones 16,24. In the zones 34 of the reinforced fabric, which are developed along the end portions of edges 7 and 11, the reinforced fabric assumes the interlaced structure shown in FIG. 7, as the stitch as feed A2 is formed 1:1 and each stitch is constituted respectively with the two yarns 18B,22B in one course and yarns 20B,32 in the next course.
The longitudinal edge zone immediately adjacent edges 9 are formed with the same fabric structure as zone 34, with one course including one elastic and one non-elastic yarn and the subsequent course including two non-elastic yarns, and always with a 1:1 needle selection which provides the tendency to roll up and to resist raveling.
In the longitudinal, outer edge zone 38 which lies between the line 14 and the zone 34,36, the fabric is formed with a plain stitch as illustrated in FIG. 9, with alternating courses wherein a first course includes the non-elastic yarns 32,20B and the other course includes an elastic yarn 18B and a non-elastic yarn 22B. The fabric in zones 34,36, and 38 thus formed is particularly strong to withstand stresses during the use. On the outside of lines 14, the fabric is formed only with yarns 20B and 22B, as the needles are always raised to follow a needle path which clears the stitches from the latches, said needle path being lower than that allowing the pickup of yarns 18B and 32, i.e. with lower yarn path trajectories as indicated by lines 19C and 19E in FIG. 8.
The article at the outer ends of portions 1 and 5 may be completed with a closure structure known as "closed toes."
It is apparent that the drawing and specification illustrate one embodiment which may be varied without departing from the scope of the invention which is to be determined by the following claims. | A continuous, tubular, one-piece panty hose is formed on a circular knitting machine, wherein the waist opening extends both transversely of the direction of knitting as well as longitudinally of the direction of knitting to form a generally rectangular opening which is surrounded by a reinforced elastic section with stitches that resist raveling or breakdown. | 3 |
BACKGROUND
The field of the present invention is railings and dividers for use in structures.
The use of railings and dividers in one form or another probably dates back to the advent of civilized society. Railings have been used in conjunction with stairs, balconies, decks, and the like to demarcate the boundaries thereof for safety and other reasons. Dividers have been employed to designate areas of, for example, a room, and perhaps to confine persons to a specific area. Dividers are found in such places as courtrooms, legislative halls and the like where access to a particular area is to be restricted.
The earliest railings and dividers were likely constructed of stone or wood, depending on intended use, availability of raw materials and the architectural style in vogue at the time. In ancient Mediterranean cultures, for example, one would expect to find a predominance of stone-made structures. In more recent times, particularly in Europe and North America, wooden railings and dividers have predominated. Indeed, until relatively recently, the architectural tendency has been to provide ornate wooden structures of intricate design.
With the advent of readily available metals and plastics for structural applications, wood for railings, dividers and other structures has been used with decreasing frequency. The new materials are generally stronger and more durable and are therefore preferred, especially where safety considerations are important.
Notwithstanding the superior structural attributes of metal and other materials, they are often aesthetically bland and lack the warmth and artistry associated with finely-crafted wooden structures. While the architectual trend in recent years has been toward a "functional" look, there are many who still prefer traditional stylings. Indeed, recent designs reveal a resurgence of more conservative constructions in residential and other structures. For those applications, a traditionally styled wooden railing or divider possessing the strength and durability found in a structure constructed from metal or the like would be desirable.
SUMMARY OF THE INVENTION
The present invention is directed to a wooden railing or divider having a metal foundation. To this end, a metal substructure provides a foundation for decorative wooden elements arranged about the substructure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a railing or divider constructed in accordance with the present invention, including a metal substructure and a wooden element (shaded) attached thereto.
FIG. 2 is a partial cross-sectional view taken along line 2--2 in FIG. 1 showing the intersection of a baluster and the handrail.
FIG. 3 is a partial cross-sectional view similar to FIG. 2.
FIG. 4 is a cross-sectional view taken along line 4--4 in FIG. 1 showing the intersection of a post member and the handrail.
FIG. 5 is a cross-sectional view taken along line 5--5 in FIG. 1 showing the intersection of a post member and the footrail.
FIG. 6 is a cross-sectional view taken along line 6--6 in FIG. 1 showing the intersection between a baluster and the footrail.
FIG. 7 is a cross-sectional view taken along line 7--7 in FIG. 1 showing the construction of a baluster.
FIG. 8 is a cross-sectional view taken along line 8--8 in FIG. 1 showing the construction of a post member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a railing or divider assembly 2 comprises a metal railing or divider 4 forming a foundation or substructure and a wooden railing or divider 6 forming a superstructure that completely surrounds the metal foundation 4. The metal foundation 4 is made from wrought iron or other suitable material while the super-structure 6 is formed from any suitable wood. The wood may be decoratively shaped in a variety of forms as required. The railing or divider assembly 2 includes a handrail assembly 8, a footrail assembly 10, a post member assembly 12 and baluster assemblies 14.
Correspondingly, the metal foundation 4 includes a metal handrail 16, a metal footrail 18, a metal post member 20 and metal balusters 22. These components are preferably welded together. The bottom of the metal post member is affixed to a surface 5 by bolting or other suitable means.
In similar fashion, the wooden superstructure 6 includes a wooden handrail assembly 24, a wooden footrail assembly 26, a wooden post assembly 28 and wooden baluster assemblies 30. These assemblies are secured together by adhesive or other suitable means. As shown in FIGS. 2 and 3, the wooden handrail assembly 24 comprises a wooden handrail member 32 mounted on the metal handrail member 16. If desired, the wooden handrail member 32 may be grooved. This would be preferable where the metal handrail member 16 has a square cross-section. When the metal handrail member 16 is relatively flat, a grooved wooden handrail member 32 may still be used but it may be necessary to employ a shim 32a to adjust the height of the wooden handrail member 32, as in FIG. 2. If a non-grooved wooden handrail member 32 is employed, it will be necessary to use wooden strip members 32b to mask the metal handrail member 16, as in FIG. 3. To fully mask the metal handrail member 16 between successive balusters, a wooden strip or fillet block 34 is used.
As shown in FIG. 6, the wooden footrail assembly member 26 comprises a wooden footrail member 36 which is grooved to accommodate the metal footrail member 18. A shim 36a allows for adjustment of the height of the wooden footrail member 36. A wooden strip or fillet block 38 is used to mask the metal footrail member 18 between successive balusters.
Turning to FIGS. 4, 5, and 8, the wooden post member assembly 28 comprises a pair of wooden postmembers 40 which are grooved to accommodate the metal post member 20 and the metal handrail member 16.
As shown in FIGS. 2, 3, 6, and 7, the wooden baluster assemblies 30 comprise a pair of wooden baluster members 42 that are grooved to accommodate the metal baluster members 22.
Thus, a wooden railing with a metal foundation has been disclosed. While embodiments and applications of the invention have been shown and described, it would be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concepts herein. The invention therefore, is not to be restricted except in the spirit of the appended claims. | A wooden railing or divider having a reinforcing metal foundation includes a metal substructure of upper and lower rail members connected by balusters, and a wooden superstructure comprising wooden elements positioned to enclose the metal substructure elements. | 4 |
FIELD OF THE INVENTION
[0001] The present invention provides a process for the preparation of Regorafenib and its pharmaceutically acceptable salt thereof.
BACKGROUND OF THE INVENTION
[0002] Regorafenib is chemically known as 4-[4-({[4-chloro-3-(trifluoromethyl)phenyl]carbamoyl}amino)-3-fluorophenoxy]-N-methylpyridine-2-carboxamide and has the structural formula:
[0000]
[0003] Regorafenib (BAY 73-4506) is an oral multi-kinase inhibitor which targets angiogenic, stromal and oncogenic receptor tyrosine kinase (RTK). Regorafenib shows anti-angiogenic activity due to its dual targeted VEGFR2-TIE2 tyrosine kinase inhibition. It is currently being studied as' a potential treatment option in multiple tumor types. The generic name Regorafenib is marketed by BAYER HEALTHCARE under the brand name STIVARGA®.
[0004] Regorafenib as a compound is disclosed in U.S. Pat. No. 8,637,553. This patent application also discloses a process for the preparation of Regorafenib, which is as shown below:
[0000]
[0005] 4-Amino-3-fluorophenol and 4-chloro-N- methyl-2-pyridinecarboxamide was condensed in the presence of potassium tert-butoxide, N,N-dimethylacetamide to form 4-(4-amino-3-fluorophenoxy)pyridine-2-carboxylic acid methylamide as a reddish brown solid and thereafter condensed with 4-chloro-3-(trifluoromethyl)phenyl isocyanate in toluene to form 4{4-[3-(4-chloro-3-trifluoromethylphenyl)-ureido]-3-fluorophenoxy}-pyridine-2-carboxylic acid methylamide (Regorafenib) as residue, which was triturated with diethyl ether and dried for 4 h under vacuum to obtain Regorafenib. However, the present inventors have observed that the obtained Regorafenib compound is not pure and further the trituration or column chromatography is not useful for industrial scale production.
[0006] WO 2008/043446 discloses Regorafenib polymorphic I, which is stated as obtained by following the process described in WO 2005/009961. Further this patent application also discloses monohydrate Form of Regorafenib, which is prepared by dissolving Regorafenib polymorph I in acetone or ethanol or acetonitrile or tetrahydrofuran and adding water as antisolvent.
[0007] WO 2008/055629 discloses Polymorph HI of Regorafenib, which is prepared by heating Regorafenib monohydrate.
[0008] WO 2008/058644 discloses Polymorph II of Regorafenib, which is prepared by suspending Regorafenib Polymorph I in ethyl acetate by heating and thereafter cooling.
[0009] In the prior-art there is no exemplified process or described process for preparing Regorafenib polymorph I, having high purity, industrially applicable and commercially viable. The present inventors have now found a process for the preparation of Regorafenib polymorph Form I, which is industrially viable.
OBJECTIVES
[0010] The objective of the present invention is to provide a process for the preparation of 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide having purity greater than 99.4%.
[0011] Another objective of the present invention is to provide a crystalline solid of Regorafenib tosylate and a process for the preparation thereof.
[0012] Another objective of the present invention is to provide a process for the preparation of Regorafenib Polymorph I having purity greater than 99.7%.
SUMMARY OF THE INVENTION
[0013] The present invention provides a process for the preparation of 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide, having purity greater than 99.4%, which comprises:
a) reacting the 4-amino-3-fluorophenol with 4-chloro-N-methylpicolinamide in the presence of potassium tertiary butoxide and a solvent selected from dimethyl acetamide, dimethylformamide, dimethyl sulfoxide; b) heating the reaction mass obtained in step (a) above 70° C.; c) quenching the reaction mass with an ester solvent and water; d) concentrating the reaction mass; e) adding an ether solvent to the residual mass obtained in step (d); f) isolating the wet solid; g) adding an alcohol solvent to the wet solid; h) heating the suspension obtained in step (g) at reflux; and i) isolating the 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide.
[0023] In another aspect of the present invention, provides a crystalline solid of Regorafenib tosylate.
[0024] In another aspect of the present invention provides a process for the preparation of a crystalline solid of Regorafenib tosylate, which comprises:
a) condensing 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide with 4-chloro-3-(trifluorornethyl)aniline in presence of 1,1′-carbonyldiimidazole and a chlorinated solvent; b) removing the solvent from the reaction mass obtained in step (a) to obtain a residual mass; c) adding p-toluenesulfonic acid to the residual mass obtained in step (b); and d) isolating the crystalline solid of Regorafenib tosylate.
[0029] Yet in another aspect of the present invention provides a novel process for the preparation of Regorafenib Polymorph I, which comprises:
a) dissolving Regorafenib tosylate in water and an ester solvent; b) adjusting the pH to about 9.0 to 10.0 with a base; c) removing the solvent from the reaction mass; d) adding a ketonic solvent to the residual solid obtained in step (c); e) heating the suspension obtained in step (d) at reflux; and f) isolating Regorafenib Polymorph I.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is an X-ray powder diffraction spectrum of 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide.
[0037] FIG. 2 is an X-ray powder diffraction spectrum of Regorafenib tosylate.
[0038] FIG. 3 is an X-ray powder diffraction spectrum of Regorafenib Polymorph I.
[0039] X-ray powder diffraction spectrum was measured on a bruker axs D8 advance X-ray powder diffractometer having a copper-Ka radiation. Approximately 500 mg of sample was gently flattered on a sample holder and scanned from 2 to 50 degrees two-theta, at 0.020 degrees two theta per step and a step time of 10.6 seconds. The sample was simply placed on the sample holder. The sample was rotated at 30 rpm at a voltage 40 KV and current 35 mA.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The term “room temperature” refers to temperature at about 25 to 35° C.
[0041] The present invention provides a process for the preparation of 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide, having purity greater than 99.4%, which comprises, reacting the 4-amino-3-fluorophenol with 4-chloro-N-methylpicolinamide in the presence of potassium tertiary butoxide and a solvent selected from dimethyl acetamide, dimethylformamide, dimethyl sulfoxide; heating the reaction mass above 70° C.; quenching the reaction mass with an ester solvent selected from group comprising of ethyl acetate, methyl acetate, isopropyl acetate, tert-butyl acetate, ethyl formate, preferably ethyl acetate and water; concentrating the reaction mass; adding an ether solvent selected from group comprising of tetrahydrofuran, diisopropyl ether, tertrahydropyran, 1,4-dioxane, methyl tert-butyl ether, ethyl tert-butyl ether, diethyl ether, di-tert-butyl ether, diglyme, dimethoxyethane, dimethoxymethane, methoxyethane, preferably methyl tert-butyl ether; isolating the wet solid; adding an alcohol solvent selected from group comprising of methanol, ethanol, isopropyl alcohol, isobutanol, n-butanol, preferably isopropyl alcohol; heating the suspension at reflux and isolating the 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide.,
[0042] In another aspect of the present invention, the 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide compound is isolated as crystalline compound, which is characterized having a powdered X-ray diffractogram (PXRD) as shown in FIG. 1 .
[0043] The reaction mass heated above above 70° C., may preferably heated to 90 to 110° C.
[0044] Preferably the reaction mass is concentrated in by distilling off the solvent. The distilling off the solvent may be carried out at atmospheric pressure or at reduced pressure. The distillation may preferably be carried out until the solvent is almost completely distilled off.
[0045] The wet solid may be isolated by methods known such as filtration or centrifugation.
[0046] Isolation can be performed by conventional methods such as cooling, removal of solvents, concentrating the reaction mass, adding an anti-solvent, extraction with a solvent and the like.
[0047] According to another aspect of the present invention provided a crystalline solid of Regorafenib tosylate, which is characterized by powdered X-ray diffractogram (PXRD) as shown in FIG. 2 .
[0048] Another aspect of the present invention provides a process for the preparation of a crystalline solid of Regorafenib tosylate, which comprises condensing 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide with 4-chloro-3-(trifluoromethyl)aniline in presence of 1,1′-carbonyldiimidazole and a chlorinated solvent selected from group comprising of methylene chloride, ethylene dichloride, chloroform, carbon tetrachloride, preferably methylene chloride; removing the solvent to obtain a residual mass; adding p-toluenesulfonic acid and isolating the crystalline solid of Regorafenib tosylate.
[0049] Removal of the solvent may be carried out at atmospheric pressure or at reduced pressure. Removal of the solvent may preferably be carried out until the solvent is almost completely distilled off.
[0050] The crystalline solid of Regorafenib tosylate may be isolated by methods known such as filtration or centrifugation.
[0051] Yet another aspect of the present invention provides a novel process for the preparation of Regorafenib Polymorph I, which comprises dissolving Regorafenib tosylate in water and an ester solvent selected from group comprising of ethyl acetate, methyl acetate, isopropyl acetate, tert-butyl acetate, ethyl formate; preferably ethyl acetate; adjusting the pH to about 9.0 to 10.0 with a base selected from group comprising of sodium carbonate, sodium hydroxide, sodium bicarbonate, potassium hydroxide, potassium carbonate, potassium bicarbonate, cesium carbonate, cesium bicarbonate, calcium carbonate, calcium bicarbonate, preferably sodium hydroxide; removing the solvent from the reaction mass; adding a ketonic solvent selected from group comprising of acetone, diethyl ketone, methyl ethyl ketone, methyl, propyl ketone, methyl isobutyl ketone, methyl tert-butyl ketone, preferably acetone to the residual solid; heating the suspension at reflux and isolating Regorafenib Polymorph I.
[0052] Removal of the solvent may be carried out in step (c) at atmospheric pressure or at reduced pressure. Removal of the solvent may preferably be carried out until the solvent is almost completely distilled off.
[0053] Regorafenib Polymorph I may be isolated by methods known such as filtration or centrifugation.
[0054] The invention will now be further described by the following example, which is illustrative rather than limiting.
EXAMPLES
Example 1
[0055] Preparation of 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide
[0056] 4-Amino-3-fluorophenol (50 gm) was dissolved in dimethylacetamide (500 ml) and cooled to 0 to 5° C. The solution was stirred for 15 minutes and potassium tertiary butoxide (50 gm) was added to the solution slowly at 0 to 5° C. The reaction mixture was stirred for 45 minutes at 0 to 5° C. and a solution of 4-chloro-N-methylpicolinamide (52 gm) in dimethylacetamide (200 ml) was added to the reaction mixture slowly for 20 minutes at 0 to 5° C. The contents were heated to 100° C. and stirred for 11 hours. The reaction mass was then cooled to room temperature and quenched with water (1500 ml) and ethyl acetate (1500 ml). The layers were separated and aqueous layer was extracted with ethyl acetate. Combined organic layers were dried with sodium sulfate and subject to carbon. Thereafter the carbon was removed through hyflow and the solvent was distilled off from the organic layer under vacuum below 55° C. to obtain the title compound as residual solid.
Chromatographic Purity (by HPLC)−89.5%
Example 2
[0057] To the residual solid obtained in Example 1 was added methyl tert-butyl ether (200 ml) at room temperature, stirred for 2 hours and filtered. To the wet solid thus obtained was added isopropyl alcohol (180 ml) at room temperature and heated to reflux. The solution was stirred for 1 hour at reflux and then cooled to 10 to 15° C. The contents were stirred for 1 hour at 10 to 15° C. and filtered. The solid obtained was dried to obtain 54 gm of 4-(4-amino-3 -fluorophenoxy)-N-methylpicolinamide.
Chromatographic Purity (by HPLC)—97.4%
Example 3
[0058] Preparation of Regorafenib tosylate
[0059] A mixture of 4-chloro-3-(trifluoromethyl)aniline (80 gm), 1,1′-carbonyldiimidazole (71 gm) and methylene chloride (640 ml) were added at room temperature and stirred for 19 hours. To the reaction mixture was added a solution of 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide (50 gm) in methylene chloride (500 ml) slowly at room temperature and stirred for 36 hours. The layers were separated and the aqueous layer was extracted with methylene chloride. Combined organic layers were dried with sodium sulfate and subject to carbon. Thereafter the carbon was removed through hyflow and solvent was distilled off from the organic layer under vacuum below 55° C. to obtain a residual mass. The residual mass thus obtained was cooled to room temperature and p-toluenesulfonic acid (33 gm) was added. The reaction mass was cooled to 10° C. and stirred for 1 hour. The solid obtained was collected by filtration and then dried to obtain 68 gm of Regorafenib tosylate.
Chromatographic Purity (by HPLC)—97.8%
Example 4
Preparation of Regorafenib Polymorph I
[0060] Regorafenib tosylate was dissolved in ethyl acetate and water at room temperature and then heated to 55° C. The pH of the solution was adjusted to 9.0 to 10.0 with sodium hydroxide solution at 55 to 60° C. The layers were separated and the aqueous layer was extracted with ethyl acetate. Combined organic layers were dried with sodium sulfate and then concentrated to obtain a residual solid. To the residual solid was added acetone and heated to reflux. The solution was stirred for 1 hour at reflux and then cooled to 5° C. The contents were stirred for 1 hour at 5° C. and filtered. The solid obtained was dried to obtain 33 gm of Regorafenib Polymorph I.
Chromatographic Purity (by HPLC)—99.7%
Example 5
Preparation of Regorafenib Polymorph I
[0061] Regorafenib tosylate was dissolved in ethyl acetate and water at room temperature and then heated to 55° C. The pH of the solution was adjusted to 9.0 to 10.0 with sodium hydroxide solution at 55 to 60° C. The layers were separated and the aqueous layer was extracted with ethyl acetate. Combined organic layers were dried with sodium sulfate and then concentrated to obtain a residual solid. To the residual solid was added methyl ethyl ketone and heated to reflux. The solution was stirred for 1 hour at reflux and then cooled to 5° C. The contents were stirred for 1 hour at 5° C. and filtered. The solid obtained was dried to obtain 33 gm of Regorafenib Polymorph I.
Chromatographic Purity (by HPLC)—99.7%
[0000] | The present invention provides processes for the preparation of i) Regorafenib (4-[4-({[4-chloro-3-(trifluoromethyl)phenyl]carbamoyl}amino)-3-fluorophenoxy]-N-methylpyridine-2-carboxamide, BAY 73-4506, Stivarga®) and its pharmaceutically acceptable salt thereof; ii) a crystalline solid of Regorafenib tosylate; iii) Regorafenib Polymorph I from Regorafenib tosylate, and iv) a pure 4-(4-amino-3-fluorophenoxy)-N-methylpicolinamide from 4-amino-3-fluorophenol and 4-chloro-N-methylpicolinamide in the presence of potassium tert-butoxide. | 2 |
This is a continuation of application Ser. No. 707,584, filed Mar. 4, 1985, now abandoned.
FIELD OF THE INVENTION
The present invention relates to medical ultrasound images, and in particular, to methods and apparatus for processing ultrasound signals in real-time.
BACKGROUND OF THE INVENTION
For years, clinical ultrasound systems have incorporated either pulsed or continuous waves (CW) ultrasound techniques for imaging of tissue structure and flow of blood therethrough. Since the tissue investigated is a dispersive medium, signals transmitted into and thereafter reflected from tissue discontinuities suffers significiant attenuation. That is, the greater the path taken by the acoustic signal within the subject, the greater the signal attenuated and otherwise changed. Previous systems have included compensation techniques such as time-controlled gain to provide correction for the anticipated attenuation by the signal in the subject tissue. Similarly, other correction techniques have been applied with varying degrees of success. Regardless of the correction techniques used thus far, certain problems remain. Typical of these problems are the multiple reflections incurred between the surface of the specimen to be investigated, and the surface of the transducer thereof within the ultrasonic probe. Moreover, for the deeper signal penetration levels, the signal becomes excessively attenuated, often obscuring critical imaging information, and unfocussed.
One approach taken by the applicant in previously filed application Ser. No. 616,581, entitled "Tissue Signature Tracking Tranceiver," incorporates the phenomenon of tissue signature analysis, wherein the transmitted pulse returns in a frequency-skewed form as a result of the transition through the tissue medium. However effective the system described therein may be, further improvements for technical and economic reasons are desired.
While the method described in the previous disclosure provides substantial improvement in overall image quality and in overall image uniformity, the following limitations exist arising from problems of implementation and economics:
(1) When filter tracking is implemented, either filter inductance or capacitance must be modulated (e.g. saturable reactors or varactor diodes) to a very great extent because the required modulation of component values is the square of the frequency range. The resulting impedance variation is significant during the frequency tracking slew. If the percentage of frequency modulation could be reduced, the modulations of circuit component parameters could be also reduced.
(2) The low-pass and high-pass cutoff frequencies must track to maintain a constant bandwidth.
(3) The detector, regardless of its sophistication, must work with the baseband RF signal. Since the video frequency (envelope) information is so close to the lowest carrier frequency at the bottom of the echo-train, there is the practical problem of designing a broadband detector that has impressive risetime performance but still suppresses carrier ripples (e.g., second harmonic). A detector capable of meeting the fast rise-time vs. low ripple criterion must contain high-order low-pass filters that represent some cost. If greater separation between the video (envelope) information and the carrier frequency were possible, one could obtain the required detector performance with a simple first-order low-pass filter after demodulation.
(4) In the design of any practical receiver, given a simple, unshielded method of packaging, one is always faced with the question of how to design a receiver performing under extremely high gain conditions without uncontrolled feedback. If, for a given complexity and size of components, one could identify an alternative design with less crosstalk from the output back to RF front-end input, one would implement such a design for that reason alone.
(5) Frequently the ultrasound pulser-receiver is required to be used in an imaging system that operates at several different ultrasound frequencies, such as 3.5, 5, and 7.5 MHz. Up until now, either broadband receivers had been used, or receivers with simple switched fixed-frequency filters have been used. A tissue-tracking receiver, operating in several ranges, of very simple design, would be highly desirable.
SUMMARY OF THE INVENTION
The ultrasound transceiver of the present invention provides a variable frequency, fixed-bandwidth reception of the signals reflected from tissue interfaces within the subject, providing improved rejection of multiple surface reflections, combined with improved signal resolution at the extreme penetration depth. The present invention further provides recovery of signals over a greater dynamic range than previously known.
Moreover, the present invention describes an ultrasound tranceiver having a detected signal, which inherently deconvolves the interaction of the transmitted pulse signal from the transducer impulse response and the tissue reflection response, providing an enhanced axial signal resolution.
The apparatus according to the present invention is embodied in hardware which provides these features, by way of a receiver which acquires and converts the receiver signals to a higher intermediate frequency having a constant bandwidth. The conversion to the higher frequency varies over time, such that the portion of the received spectrum changes, while maintaining the constant bandwidth requirement thus described. The particular details of the upconverted superheterodyne receiver according to the present invention provides enhanced signal processing and reduces both the false signals and economic costs for implementation. Thus the present invention provides the desired signal processing enhancements while providing a simple and cost-effective system.
BRIEF DESCRIPTION OF THE DRAWING
These and other features of the present invention can be better understood by reading the following detailed description, taken together with the drawing, wherein:
FIG. 1 is a block diagram of the upconversion asynchronous transceiver according to the present invention;
FIG. 2 is a graph showing the signal components according to the frequency upconversion process according to the present invention;
FIG. 3 is a graph demonstrating the envelope detection according to one embodiment of the present invention;
FIG. 4 is a graph showing three modes of transducer operation; and
FIG. 5 is a graph showing the differing filter passbands according to the frequency ranges used according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention includes the transceiver described by pending application Ser. No. 616,581 by the same inventor, filed June 4, 1984, herein incorporated by reference.
FIG. 1 shows a preferred functional design of the improvements comprising a pulser-receiver performing as summarized elsewhere. The functions of the AGI master clock 640, pulser 642, probe crystal 644, TR/ATR switch 646, bandpass filter 648, RF preamp 652, and time-controlled gain (TCG) ramp generator 650 are the same as in the design of the transceiver previously disclosed in the application Ser. No. 616,581. The TCG gain control is received by RF amplifier 652 typically a part number MC1350 by Motorola, Inc. The frequency spectrum of return echoes is only broadly confined by the broad bandpass filter 654 having a bandpass in the 2-7 MHz range. This filter acts as gross preselector whose function is mainly to prevent out-of-band (e.g. broadcast radio interference) signals from overloading amplifier 652 and causing intermodulation distortion in subsequent stages. A "tissue signature control" (TSC) ramp is generated at 656 and this signal frequency modulates a varactor-diode controlled voltage-controlled oscillator (VCO) 658 whose function in the system is to act as a local oscillator in an upconversion superheterodyne receiver. The output of VCO 658 is combined with the amplified RF echo signal at leads 659 at balanced modulator 660, typically part number MC1595 by Motorola, Inc., to produce sum-and-difference-frequency signals at point 664. A balanced modulator is used as the mixer stage because this method produces sum-and-difference components and suppresses the local oscillator in its output signal at leads 661 without the need for band-reject or notch filters. The upconverted signals at point 661 are applied to bandpass filter 662 that passes the difference frequency while rejecting the sum frequency. The output at leads 663 from this bandpass filter is fed into the "intermediate frequency" amplifier 664, also an MC1350, (a term borrowed from typical down-conversion superheterodyne receivers). The output at leads 665 is applied to an bandpass filter 666 identical to filter 662. The purpose of the second filter 666 is to steepen the dropoff rate of the skirts of the filter function of 662 so as to maximize the rejection of the sum frequencies. The output 667 is applied to log compressor 678, typically a part number 441 by Texas Instruments Corp., to video detector 680, and the output is deconvolved by circuit 682, resulting in the "analog video output" 684. The circuit 682 includes an amplifier 690 having a gain adjustment to provide contrast control. The subsequent filter 692 provides the deconvolution time function indicated within block 692 to provide image signal enhancement. The signal is buffered by amplifier 694, which also receives a blanking signal to inhibit the output video signal during the scan retrace time. It is important that filters 662 and 666 reject the sum frequency signal as improved sum frequency signal rejection greatly simplifies the problem of performing optimum envelope detection at 680 and deconvolution at 682.
The frequency upconversion process will be modelled in order to appreciate the importance of adequate sum frequency rejection, shown in FIG. 2. The descending echo specturm 700 is mixed with a descending local oscillator frequency 702 in the neighborhood of 17 MHz to produce a constant "intermediate frequency" spectrum 704 at the difference frequency of 14 MHz. The sum frequency spectrum 706, occurring at 19-21 MHz should be rejected from the IF amplification process. Otherwise a heterodyne in the neighborhood of 6 MHz will appear in the detector output.
FIG. 3 clarifies these events. A typical single incoming RF echo signal 720 will have a 3-MHz carrier frequency and a duration of 1 microsecond. The video, or picture envelope information (pixel detail) is indicated by 722. The upconverted equivalent of 720, filtered to pass only the difference frequency is indicated as 724. The significance of the waveform 724 is that it contains a perfect reconstruction of the original envelope 722 and a high frequency carrier 726 of 14 MHz. Such a waveform, passing through a simple detector, can easily produce a nearly perfect video representation of the original envelope (728). If the sum frequency component enters the IF amplifier, the resulting waveform 730 produces a 6-MHz heterodyne 732, which leads to a "dirty" detector 734 comprising 6 MHz ripple content. The detector output 728 or 734 must be free of ripple content, at either 6 or 17 MHz, because the post-processing deconvolution has the effect of preemphasizing high-frequency ripple components in the detector output. However, there is less space and cost involved in improving the IF bandpass curve to steepen the skirts than to employ high-order lowpass filters within the detector stage. Also, by using more bandpass filtering at the IF level, there is better rejection of residual local oscillator signal. This is important because presence of the local oscillator at point 676 (of FIG. 1) can pre-bias the demodulator 680 (of FIG. 1), thereby artificially masking signal detection in the 30 dB range because of the continuously present oscillator feedthrough. The difference signal is used rather than the sum signal because the oscillator residuals are higher in frequency than the IF frequency, hence the oscillator feedthrough is more easily suppressed. An upconversion receiver is used (rather than the customary downconversion type) because true envelope reconstruction with a very high ripple frequency (2×14 MHz) is produced in a very direct way, and the filtering is much more economical because fewer filters are necessary and because the inductances at the IF frequency are smaller. Tuning is not critical because the entire receiver design is inherently broadbanded (approximately equal to 10 percent relative bandwidth). The employment of a superheterodyne receiver of this type has the advantage that signals are shifted far away from the incoming RF spectrum early in the processing: the feedback problem is minimal compared to a straight baseband RF (or TRF) receiver or even compared to a conventional downconversion superheterodyne. Moreover, the upconversion receiver can be adapted to operate in several distinct frequency ranges (3.5, 5, 7.5 MHz of FIG. 4) by introducing a switchable DC bias into the TSC ramp waveform. This can be accomplished by the use of an operator switch 688 that acts on generator 656 (of FIG. 1).
In the event that a frequency range switch 688 is not used, the entire receiver will function with a single choice of ultrasound transducer frequency spectra, and the broad bandpass filters 648 or 654 can have its passband reduced only to cover the more limited range to minimize IM distortion. The choices available for the broad passband filters 648 or 654 are summarized in FIG. 5.
The frequency response 800 for the broad bandpass filters 648 or 654 for the general case (receiver switchable among three frequency ranges) is wide enough to admit every frequency capable of being tissue signature-processed. For example, if the receiver were to function for a 3.5 MHz crystal, the passbands 802, 804, 806 would be active through the entire receiver. When the receiver is switched to the 5-MHz mode, a similar set of moving passbands becomes active in region 808. Obviously the total frequency response 800 of filters 648 or 654 need be only as broad as the selectable passbands employed through the manner of programming the local oscillator. It should be noted that programming the local oscillator 658 is a much more economical way of moving the passband frequency spectra of a receiver than dynamically tuning highpass and lowpass filter sections.
In the field of diagnostic medical ultrasound, this oscillator tuning after the preselector filter is generally permissible only because the ratio of stopband to passband amplitudes is lower than the "strong adjacent carrier" problem in commercial (short wave) communications systems, plagued with substantial signal fading problems.
The main source of "strong adjacent carrier" signal in ultrasound is the low-frequency component (1.6-2.3 MHz) present along with the high-frequency information spectra (3.5-4.8 MHz) of interest when imaging near echoes. Since even this strong low-frequency component rarely exceeds the amplitude of the high-frequency components, there is generally no significant problem in allowing all frequencies to slip through the preselector (648, 652, 654 of FIG. 1) and to feed the balanced modulator.
When considering ultrasound receiver designs with extremely wide dynamic range (approximately 60 dB at any given depth, approximately 85-105 dB over the entire echo-train range), the absolutely perfect suppression of intermodulation distortion arising from low-frequency components entering the modulator may become important. In order to achieve this higher merit of receiver performance, one might consider designing an upconversion receiver of FIG. 1 that includes a "tracking preselector" (replacing 648, 652 of FIG. 1) with tunable RF circuitry being controlled by a signal on leads 657 from the ramp generator 656. By combining a narrow passband tunable preselector with the full upconversion feature, one would in essence obtain the maximum possible dynamic range (reducing IM distortion and noise) for a given bandwidth (rise time merit).
These and other embodiments of the present invention are within the scope of the present invention. Further embodiments, and substitutions by one skilled in the art are clearly within the present invention, which is not to be limited, except by the claims which follow. | An improved ultrasound transceiver providing enhanced imaging by selective filtering of the received signal to provide a variable frequency, constant bandwidth filtering of the received echo signals. The transceiver provides a constant bandwidth filtering by upconverting the received signals to a higher incremented frequency, which is thereafter detected. The resulting signals are then displayed wherein the number of false multiple images is reduced, and the signal quality from the deeper tissue discontinuities is enhanced. The resulting signal is thereafter post-processed to provide enhanced information which is used to display structural features. | 8 |
RELATED APPLICATION INFORMATION
[0001] This application is a continuation of application Ser. No. 09/565,476, filed May 5, 2000.
FIELD OF THE INVENTION
[0002] The present invention generally relates to warp knitted fabrics. It particularly relates to an open mesh structure with a stand-off design for athletic apparel.
BACKGROUND ART
[0003] When an athlete performs, perspiration from the athlete's body may lead to a “sticky” feeling when the perspiration lingers on the skin surface. Consequently, many athletes wear mesh jerseys (e.g., football, track, soccer, hockey, etc.) that have open holes in the jersey fabric (open mesh design) allowing perspiration to escape from the skin surface through the holes in the athletic garment. These mesh jerseys and other garments provide greater personal comfort and a more breathable environment to the high-performance perspiring athlete. Many such open mesh garments are produced, for example, using warp knitting machines.
[0004] Warp knitted open mesh structures known in the art (such as the well known “Football Mesh” Jersey) are often constructed of, for example, at least two continuous filament synthetic yarns such as nylon or polyester. Such yarns may be carried, for example, by two guide bars of a warp knitting machine. The fabric may be stitched using a variation of the Atlas technique wherein both guide bars knit in opposite directions leaving clean holes in the fabric. Such clean holes may be created in the mesh design by using ground yams that do not knit on the same needle therein leaving subsequent repetitive courses knitted without a connection between the two adjacent needles. The resulting fabric has the known open hole mesh structure. Commonly, the resulting fabric has a flat surface with a population of open holes staggered throughout but spaced equidistantly, while the non-hole solid closed portions generally comprise approximately 50% of the remaining fabric surface.
[0005] Despite the afore-mentioned moisture reduction qualities, the base of the open mesh jersey fabric still lays directly on the skin of wearer, often resulting liquid saturation of the jersey after perhaps minimal use. When perspiration occurs, the fabric may become heavier with sweat content, stick to the wearer, or otherwise cease to comfortable athletic apparel. Therefore, there is a need for an athletic jersey design providing greater comfort and breathability to the athlete.
SUMMARY OF THE INVENTION
[0006] The present invention overcomes the previously mentioned disadvantages by providing an open hole mesh fabric structure with a stand-off design. In accordance with the present invention, the open hole mesh fabric includes raised members positioned at a different height (depth) from the fabric base which effectively separates a major portion of the fabric from the wearer. The fabric may be knitted on a warp knitting machine having at least five guide bars, wherein one guide bar may be, for example, a Jacquard guide bar. A warp knitting machine including a Jacquard guide bar is described in U.S. Pat. No. 5,628,210 to Mista et al., entitled WARP KNITTING METHOD, MACHINE, AND FABRIC MADE THEREFROM.
[0007] In accordance with the present invention, a traditional two-dimensional open hole mesh fabric is particularly knitted with raised members that stand at a different height than the fabric base on the technical back of the fabric. The raised members add a third dimension of depth or thickness to the fabric and are knitted in the solid areas between the open holes of the fabric located in the fabric base. Advantageously, the raised members are the only portions of the fabric which contact the fabric wearer during fabric use wherein the number of members are placed in a pre-determined, appropriate ratio with the number of holes located in the fabric base. These raised fabric members may also be referred to as “raised dots” or “high-density support sections”.
[0008] The three-dimensional fabric structure enables the ground structure or base of the fabric to be suspended from (i.e., stand-off) the wearer's body thereby significantly reducing the surface area and volume of fabric material contacting the skin surface. The separation of the fabric base from the wearer's skin provides a superior level of comfort and breathability to the apparel user. The comfort and convenience of the apparel fabric may be further enhanced by selecting fabric materials with hydrophilic or hydrophobic properties. These advantageous materials include, but are not limited to continuous filament synthetic polyester and nylon yarn material. Also, chemical finishes and treatments may be added to the fabric to enhance apparel functionality.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is an exemplary stitch diagram illustrating a stitch pattern of a ground yarn of a fabric according to the present invention.
[0010] [0010]FIG. 2 is an exemplary stitch diagram illustrating a stitch pattern of an elastomeric yarn of a fabric according to the present invention.
[0011] [0011]FIG. 3 is an exemplary diagram illustrating a stitch pattern of a first and second threaded yarns of a fabric according to the present invention.
[0012] [0012]FIG. 4 is a stitch diagram illustrating a stitch pattern of a Jacquard yarn of a fabric according to the present invention.
[0013] [0013]FIG. 5 is a diagram of an exemplary guide bar configuration for construction of a fabric according to the present invention.
DETAILED DESCRIPTION
[0014] A preferred embodiment of a fabric according to the present invention may be constructed using a warp knitting machine having at least five guide bars. The exemplary knitting machine may include a plurality of pattern bars wherein at least two different groups of pattern bars are selected from the plurality of available frontmost pattern bars. Also, in a preferred embodiment, the fabric may have a repeat length of 28 stitches and a repeat width of 16 needles, although any suitable repeat length or width may be used.
[0015] [0015]FIGS. 1 and 2 illustrate exemplary stitch patterns for a “ground” yarn and an “elastomeric” yarn for use in constructing a fabric according to the present invention. In constructing a fabric according to the present invention, a preferred knitting machine includes guide bars # 4 and # 5 that knit the ground yarn and the elastomeric yarn to form a base fabric construction. Preferably, guide bar # 4 is a fully threaded ground bar that stitches the ground yarn in an exemplary stitch pattern as shown in FIG. 1, using a preferred chain stitch, although any suitable stitch may be used. Guide bar # 5 (the backmost bar in the illustrated example) advantageously lays a Lycra spandex yam or other elastomeric yarn into the fabric, as shown in FIG. 2.
[0016] [0016]FIG. 3 provides a stitch diagram showing the stitching patterns for a first threaded yarn and a second threaded yarn of a fabric according to the present invention. The first and second threaded yarns may be carried by guide bars # 1 and # 2 of an exemplary knitting machine such as that described above. Guide bars # 1 and # 2 may include, for example, 24 pattern bars, wherein the group of pattern bars 1 - 12 (the frontmost group) comprise guide bar # 1 and the group of pattern bars 13 - 24 (the second frontmost group) comprise guide bar # 2 . Also, in this exemplary embodiment, guide bars # 1 and # 2 are positioned such that guide bar # 1 stitches on top of guide bar # 2 during knitting. The stitching patterns followed by these guides bars help create the raised members of the present invention.
[0017] As shown in FIG. 3, both guide bars # 1 and # 2 preferably knit first and second threaded yarns, respectively. Guide bar # 1 may form a float of a magnitude equaling, for example, 6 needles (5 needle spaces) while guide bar # 2 may make a float of a shorter magnitude equaling, for example, 4 needles (3 needle spaces) at the same time and location in the fabric so that the two floats overlap. Floats of other magnitudes may be utilized as well. Guide bars # 1 and # 2 may preferably be threaded in a 1-in, 1 5 -out arrangement.
[0018] As the fabric relaxes during and after knitting, the floats formed by guide bar # 1 “collapse” (i.e., contract to a smaller width and/or increased density) from the fabric base and stand erect from the ground structure of the fabric in the form of raised members 10 , 12 . These raised members ( 10 , 12 ) maybe referred to as “raised dots” or “high-density support sections. In concerted action with guide bar # 1 , the floats formed by guide bar # 2 both support and help push the raised members ( 10 , 12 ) away from the fabric base structure thereby maximizing the height and thickness of the raised members. These raised members ( 10 , 12 ) may take the form of “croquet hoops” or “McDonald Arches”. It is noted that these terms and other alternative terms used herein are being used for purposes of clarity, and should not be construed as limitations on the present invention, and that the raised members ( 10 , 12 ) may be formed in any suitable shape using different float lengths, yarns and other variables as understood by one skilled in the art.
[0019] In accordance with an embodiment of the present invention, a Jacquard bar, which is either a single bar or, as illustrated, a compound set of 2 bars, is designated as guide bar # 3 (in the next position following guide bars # 1 and # 2 ) and may knit a Jacquard yarn in an exemplary stitching pattern as shown in FIG. 4. As illustrated in FIG. 4, the Jacquard bar (guide bar # 3 ) preferably follows a stitching pattern that creates open holes in the fabric. In concerted action with guide bar # 3 , the raised members formed by guide bars # 1 and # 2 advantageously alternate with the open holes formed by the Jacquard yarn, wherein the raised members are positioned in the closed spaces (no open holes) of the fabric base. In a preferred embodiment, the formation of the open holes may be independently controlled such that the population of raised members to open holes in the fabric follows a useful, predetermined ratio ensuring apparel quality and functionality.
[0020] In constructing a fabric according to the present invention, a warp knitting machine is preferably provided with a fall plate located in the next position following guide bar # 3 . The fall plate functions to help lift and position both the first and second threaded yarns being knitted by guide bars # 1 and # 2 (forming floats and raised members) and the Jacquard yarn being knitted by guide bar # 3 to the technical back of the fabric. This function of the fall plate helps ensure that the raised members are predominately located on the technical back of the fabric structure while also ensuring that the technical face side of the fabric structure is smooth and clean (traditional two-dimensional form). This action also helps to ensure the aesthetic quality of the garment's outer face. Advantageously, the raised members on the technical back of the fabric contact the wearer, thereby forcing most or all of the ground structure away from the wearer and enabling convenient and comfortable use of the garment. The open holes in the invention fabric allow efficient discharge of moisture for enhanced comfort to the wearer.
[0021] Any suitable yarns may be used to form a fabric according to the present invention. It is understood in this respect that the terms “threaded yarn”, “Jacquard yarn”, “ground yarn”, and “elastomeric yarn” are purely used for convenience and clarity, and are not meant to imply or create any limitation of the present invention. Preferably, the first and second threaded yarns may be 5 ply to 8 ply synthetic continuous flat filament or textured nylon yarns. These yarns may comprise a multifilament yarn of 30 to 150 denier and a filament count of 10 to 200 filaments. In a particularly preferred embodiment, a relatively heavy 8 ply 70/34 textured nylon may be used. These yarns force the floats to collapse resulting in the raised members (standing off from the fabric base) of the invention fabric.
[0022] Similarly, the Jacquard yarn may preferably be a synthetic continuous flat filament or textured nylon yarn (multifilament) of 10 to 100 denier and a filament count of 5 to 150 filaments. The ground yarn may be a synthetic continuous flat filament or textured nylon yarn (multifilament) of approximately 20 to 150 denier and a filament count of approximately 5 to 200 filaments. The elastomeric yarn is preferably a spandex yarn (synthetic continuous filament) of 40 to 400 denier, a preferred width being 140 denier.
[0023] In accordance with the present invention, the fabric described herein may be formed using a multi-bar Raschel Warp Knit Machine, preferably on the Textronic type MRSEJF 31/1/24 (24 gauge) which is sold and manufactured by Karl Mayer Textile Machine in Obershausen, Germany. As shown in FIG. 5, this exemplary warp knitting machine is a 31 bar machine that includes 24 guide bars ( 20 ) in the frontmost positions numbered 1-24, two Jacquard compound bars ( 30 ) in positions 25-26, and a fall plate ( 32 ) in the 27 th bar position. Also, the machine includes a ground stitching bar ( 34 ) in position 28, two “inlay” bars ( 36 , 38 ) in positions 29-30 (which need not be used with the present invention), and a backmost Lycra bar ( 40 ) in position 31 for the elastomeric yarn.
[0024] In another embodiment in accordance with the present invention, the fabric described herein may be reproduced using an alternative warp knitting machine, an example being the Karl Mayer Textronic Type MRSEJF 53/1/24. This machine has the Jacquard bar positioned behind the fall plate (rather than in front of the fall plate) enabling the raised member design to be produced wherein the yarn knitted by the Jacquard bar is not forced to the technical back of the fabric. Again, it is understood that these warp knitting machines are exemplary and the present invention is in no way limited to the two described knitting machines.
[0025] Also, in accordance with the present invention, the fabric construction process may include chemical applications to further enhance apparel quality and performance. The chemical applications may include, but are not limited to hydrophobic applications such as Zonyl 7040 (a product of CIBA Chemical), Zepel (a product of Dupont), Scotchgard (a product of 3M Company), chemical coating, and laminating. A fabric according to the present invention may include any useful combination of the raised member design, yarn ingredient selection, and chemical applications.
[0026] It is noted that those skilled in the art can understand that the invention fabric described herein is not limited to sports applications. Additional applications of the present invention may include, but are not limited to general medical and sports medicine uses. Therefore, any further uses of the invention fabric described herein are contemplated here and are within the scope of the invention.
[0027] It is similarly noted that those skilled in the art will understand that the invention fabric may be constructed using additional guide bars and/or pattern bars. Also, the fabric of the present invention may of course include more features such as additional yarn elements. This list of additional features is not exclusive, and it is to be understood that any such embodiments are contemplated here and are within the scope of the present invention. | A fabric including raised members that effectively separate the wearer from the fabric base. The raised members add a third dimension of depth or thickness to a traditionally two-dimensional piece of apparel allowing the fabric base to remain separate from the wearer's body which provides greater comfort and breathability to the wearer. The raised members may be placed in useful proportion with open holes or closed spaces of the fabric enhancing the quality and functionality of the apparel. | 3 |
This is a continuation of application Ser. No. 000,774, filed Jan. 6, 1987, now abandoned.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to an epoxy resin composition for the manufacture of a copper-clad laminate. More particularly, it provides the epoxy resin composition having an excellent adhesive property to metal.
(2) Description of the Prior Art
Due to a high density of a printed circuit board in recent years, it has been proposed to make the printed circuit board in a high multi-layered structure and the diameter of each through hole smaller, resulting in requirement for a printed circuit board material having a good drilling properties in time of drilling a through hole. Among the drilling properties, the occurence of smears is in serious problem in improvement of the drilling properties because it prevents conduction between an inner-layered circuit copper and a plated copper plated on the through hole causing a considerable decline of reliability for connection of the through hole. To solve such problem, there is a way to remove such smears.
Normally, makers of printed circuit boards have removed the smears by use of concentrated sulfuric acid, hydrofuluoric acid, chromic acid or the like, but these procedures have problems in view of safety. Further, such a conventional treatment provides cause to spoil the inner wall of the through hole and decrease reliability for connection of the through hole.
Further, as another means to prevent the decline of the drilling property due to the smears, there is a way to prevent occurrence of them. The smears are caused due to the resin, softened by a friction heat occurring at the time of drilling, being adhered to a section of the inner-layered circuit copper foil within the through hole. The conventional copper-clad laminate is manufactured by the use of the epoxy resin or the like as a prepreg resin which comprises dicyandiamide as a hardener. When such resins are hardened, the softening and melting-adhesion temperature thereof is low. Even though it has fully been hardened, its softening and melting-adhesion temperature is about 250° C. It is generally said that the drilling temperature at drilling reaches about 300° C., therefor, when drilling the conventional copper-clad laminate, the hardened resin is softened, and thus, occurrence of the smears is inevitable.
Still further, when the printed circuit board carrying parts is used, its use temperature may reach over 100° C. Accordingly, it must have a long-term heat resistance in atmosphere. In the case that the laminate made of the conventional epoxy resins hardened by dicyandiamide is used for a long time in a drier at 170° C., it takes about 500 hours until the ratio of maintaining flexural strength reaches not more than 50%. If occurrence of the smears will be prevented and the aforesaid time will be prolonged further, the copper-clad laminate will enhance reliability furthermore.
As a resin satisfying the aforesaid two requirements, there are epoxy resins hardened by a multi-functional phenolic compound. When applying for the printed circuit boards the copper-clad laminate of the epoxy resins hardened by the multi-functional phenolic compound, the occurrence of the smears at the drilling time is less than one-half of the conventional copper-clad laminate of the epoxy resins hardened by dicyandiamide.
In addition, the former is superior to the latter in view of long-term heat resistance. More particularly, the treatment time at 170° C. of the former at the time when the ratio of maintaining flexural strength reaches not more than 50% becomes more than twice longer than that of the latter.
However, in view of adhesive property to metal such as copper foil, the epoxy resins hardened by the multi-functional phenolic compound are inferior to the conventional epoxy resins. For example, whereas the peeling resistance of the copper foil (its one side is roughened) having the thickness of 35 μm of the conventional product is about 2 kg/cm, that of a product hardened by the multi-functional phenolic compound is 1 to 1.5 kg/cm.
Further, the peeling resistance of a product of which metal glossy surface is roughened and oxidized is also decreased. For example, concerning the adhesive property to a glossy surface of the copper foil provided with the above treatments, the peeling resistance of the conventional product is about 1.5 kg/cm, while that of the product made of the epoxy resins hardened by the multi-functional phenolic compound is about 0.5 to 1 kg/cm. Further, when measuring the peeling resistance of the test pieces of those products dipped in a hydrochloric acid, that of the dipped conventional product is nearly similar to that of a non-dipped conventional product, while that of a dipped product hardened by the multi-functional phenolic compound is reduced to half over that of a non-dipped product hardened by same.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an epoxy resin composition hardened by a multi functional phenolic compound for a copper-clad laminate which is used for a printed circuit board. More specifically, it provides an improved adhesive property to metal for the said composition which provides a good drilling property and a long-term resistance in atmosphere for a copper-clad laminate.
It is another object of this invention to provide an epoxy resin composition for a copper-clad laminate, which has a high peeling resistance of a copper foil even after it has been treated with hydrochloric acid.
It is a further object of this invention to provide an epoxy resin composition which has an excellent storing stability of solution thereof.
That is to say, the epoxy resin composition for a copper-clad laminate of the present invention is characterized by comprising an epoxy resin having at least two epoxy groups in one molecule, a phenolic compound having at least two functional groups in one molecule as a hardener, an imidazole compound having a masked imino group as a hardening accelerator, and one or more of nitrogen compounds selected from the group consisting of urea derivatives represented by the formula R 1 -NH-CO-NH 2 , wherein R 1 is hydrogen or an organic group, acid amide compounds, and guanidine derivatives.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The epoxy resin which is used in this invention is a multi-functional one having at least two epoxy groups within one molecule, but it is not limited to a particular expoxy resin. For example, it may be bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type expoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin, aliphatic chain type epoxy resin and their halides, hydrides, or the like. The molecular weight of the epoxy resin is not limited specifically. Further, it is possible to make a combination of two or more epoxy resins.
Further, any phenolic compound which is a multi-functional one having two or more functional groups within one molecule and can be polymerized with the epoxy resin is acceptable. For example, it may be bisphenol A, bisphenol F, polyvinylphenol or novolak resins obtained from phenol, cresol, alkylphenol, catechol, bisphenol A, bisphenol F or the like, and halides of these phenolic resins. It is also possible to make a combination of two or more multi-functional phenolic compounds. The amount of the multi-functional phenolic compound is not limited to a particluar value, but in view of drilling property, the number of the hydroxyl groups is preferably 0.5 to 1.5 equivalent to the epoxy groups of the epoxy resin.
The hardening accelerator to be used is an imidazole compound of which imino group has been masked by acrylonitrile, isocyanate, melamine acrylate or the like. When this hardening accelerator is used, it is possible to obtain a prepreg having twice or more storing stability of a conventional one.
The imidazole compounds to be used in this invention include imidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl -2-methylimidazole, 2-heptadecylimidazole, and 4,5-diphenylimidazole,
The masking agents include acrylonitrile, phenylene diisocyanate, toluene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, methylene bisphenylisocyanate, melamine acrylate, and the like.
It is also possible to make a combination of two or more hardening accelerators.
The amount of the hardening accelerator to be used is not limited, but it is preferably 0.01 to 5 weight parts per 100 weight parts of epoxy resins. When the amount of the hardening accelerator is less than 0.01 weight parts, the effect for accelerating hardening becomes small. When the amount is more than 5 weight parts, storing stability becomes decreased.
The urea derivative to be used in this invention is represented by the following formula,
R.sup.1 NH-CO-NH.sub.2
(in which, R 1 is hydrogen or an organic group.)
The substituent R 1 is hydrogen, or an organic group, such as, alkyl group, cyano group, nitro group, nitroso group, acyl group, a substituent containing alkyl group or alkenyl group, a substituent containing aromatic ring such as phenyl group, a substituent containing a heterocyclic ring like imidazole.
More concretely, the urea derivatives include, for example, urea, N-monoalkylurea, N-allylurea, acetylurea, benzoylurea, benzenesulfonylurea, p-toluenesulfonylurea, phenylurea, nitrosourea, nitrourea, biurea, biuret, guanylurea, γ-carbamylpropyltriethoxysilane, other ureid compounds, isourea compounds, semicarbazid compounds, and the like. Each of them may be chain-type or ring-type. Urea is used preferably.
The acid amide compound to be used in this invention has a structure represented by the following general formula such as
R 2 CONR 3 R 4 Primary amide
(R 2 CO) 2 NR 3 Secondary amide
(R 2 CO) 3 N Tertiary amide
(in which R 2 , R 3 , and R 4 are each hydrogen, an alkyl group, a halogen atom or an aryl group.)
More concretely, the acid amide compounds are formamide, formethylamide, formdimethylamide, formallylamide, acetamide, acetomethylamide, acetodiethylamide, methylenediacetamide, ethylidendiacetamide, chloralacetamide, chloralformamide, diacetamide, diacetomethylamide, triacetamide, acetochloroamide, acetobromoamide, benzamide, dibenzamide, tribenzamide, N-chlorobenzamide, N-bromobenzamide, benzanilide, and the like. Each of them may be chain or ring compounds. Preferably, the primary amides are used.
Further, the guanidine derivatives to be used in this invention has a structure represented by the following formula; such as
R.sup.5 NH-CNH-NHR.sup.6
(R 5 and R 6 are each hydrogen, an alkyl group, a halogen atom or an aryl group.)
More concretely, the guanidine derivatives include dicyandiamide derivatives such as dicyandiamide, dicyandiamide-aniline additive, dicyandiamide-methylaniline additive, dicyandiamide-diaminodiphenylmethane additive, dicyandiamide-dichlorodiaminodiphenylmethane additive, dicyandiamide-diaminodiphenylether additive or the like; guanidine salts such as aminoguadine hydrochloride, guanidine hydrochloride, guanidine nitrate, guanidine carbonate, guanidine phosphate, guanidene sulfamate, aminoguanidine bicarbonate; acetylguanidine, diacetylguanidine, propionylguanidine, dipropionylguanidine, cyanoacetylguanidine, guanidine succinate, diethylcyanoacet ylguanidine, dicyandiamizine, N-oxymethyl-N'-cyanoguanidine, N,N'-dicarboethoxyguanidine, chloroguanidine, bromoguanidine, and the like.
It is also possible to make a combination of two or more nitrogen compounds.
The amount of said nitrogen compound to be used is preferably 0.1 to 10 weight parts per 100 weight parts of epoxy resin. When it is less than 0.1 weight part, the adhesion strength such as peeling resistance of the copper foil is insufficient. On the other hand, when it is more than 10 weight parts, the drilling property and the heat resistance become inferior.
In the case the guanidine derivatives are used as the nitrogen compound, it is desirable to use a coupling agent at the same time. By using the guanidine derivative together with the coupling agent, it is possible to improve remarkably the peeling resistance of the copper foil.
The coupling agent to be used includes silane coupling agents, titanate coupling agents, or the like.
The silane coupling agents include γ-glycidoxypropyltr imethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, N-β(aminoethy)-γ-aminopropylmethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysila ne, N-phenyl-γ-aminopropyltrimethoxysilane, N-vinylbenzil -δ-aminopropyltriethoxysilane, and the like. Any silane coupling agent that has a functional group reactive with epoxy group or phenolic hydroxyl group and the hydrolyzable alkoxy group at the same time may be enployed.
The titanate coupling agents include isopropyl-tri-isostearoyl titanate, isopropyl-tri-dodecylbenzene-sulfonyl titanate, isopropyl tris (dioctylpyrophosphate) titanate, tetraisopropyl bis (dioctylphosphite) titanate, tetraoctyl bis (di-tridecylphoshite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, and the like. Further, any titanate having a low molecular weight is acceptable.
The amount of the coupling agent to be used is preferably 0.1 to 10 weight parts per 100 weight parts of epoxy resins. When it is less than 0.1 weight part, there is no effect for the peeling resistance of the copper foil.
When it is more than 10 weight parts, the heat resistance and the drilling property become decresed.
The epoxy resin composition for a copper-clad laminate of this invention is used in various forms. When it is coated on or impregnated in substrates, a certain solvent is often added. The solvents to be used include acetone, methyl ethyl ketone, toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethyleneglycol-monomethylether, N,N-dimethylformamide, N,N-dimethylacetamide, methanol, ethanol, and the like. Further, it is possible to make a combination of two or more above solvents.
The concentration of a resin content in a varnish is not limited, but it is preferably 20 to 90 weight per cent. Further, it is possible that the varnish contents such an ordinary additive as flame-retardants, fillers, pigments or the like.
The prepreg can be obtained by impregnating the substrate with the varnish obtained by the above blending, and drying at a temperature of 80° to 200° C. within a drying furnace. The term "drying" in this invention means the removal of the solvent in the case it is used. If no slovent is used, it means that fluidity at a room temperature disappears.
The substrate to be used in this invention includes a woven cloth such as glass fiber, aramide fiber, silica fiber, SiC fiber or the like, a non-woven cloth, paper, or the like, and it is not limited particularly.
By making use of the prepreg obtained by the above procedures, the copper-clad laminate is produced. The conditions for the manufacture of the copper-clad laminate are the same ones in a known manufacturing process. The normal drying conditions are as follows: 30 to 120 minutes at a temperature of 150° C. to 170° C. and under the pressure of 40 to 80 kg/cm.
It is considered that the reason why the adhesion strength of the copper foil is increased by the present resin composition is due to that the aforesaid nitrogen compound reacts with a thin metal oxide layer on the copper foil surface to produce a new organic metal compound. The fact that the nitrogen compound is reactive with the metal oxide under certain circumstances was confirmed by the following process.
The IR spectrum of a test sample in which a biuret is mixed with zinc oxide is shown in FIG. 1.
The IR spectrum of such mixed sample heated for one hour at 170° C. is shown in FIG. 2.
The IR spectrum of biuret is heated for one hour at 170° C.
Thus, only when the biuret was mixed with the zinc oxide and then heated, absorption is generated at 2080 cm -1 and 2200 cm -1 , and therefor it is considered that the organic metal compound is produced. In case of copper oxide, the same result was obtained. The same operation has been conducted for the sample obtained by mixing guanidine and zinc oxide and heating, and thus obtained IR spectrum is shown in FIGS. 4 to 6. It is considered that the acid amide compound shown the same conditions (not illustrated).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows IR spectrum of a mixture of biuret and zinc oxide.
FIG. 2 shows IR spectrum of a sample obtained by heating a mixture of biuret and zinc oxide for one hour at 170° C.
FIG. 3 shows IR spectrum of a sample, obtained by heating biuret for one hour at 170° C.
FIGS. 4 to 6 show respective IR spectra, when the aforesaid same operations for guanidine carbonate were carried out.
EXAMPLES 1 to 18 AND COMPARATIVE EXAMPLES 1 to 10
Hereinafter, the present invention will now be described by the following Examples, but the scope of this invention is not limited to those Examples.
EXAMPLE 1
______________________________________Brominated bisphenol A-type epoxy resin 80 weight parts(Epoxy equivalent 530)Phenol novolak type epoxy resin 20 weight parts(Epoxy equivalent 200)Phenol novolak resin 30 weight partsUrea 2 weight parts2-ethyl-4-methylimidazole of which imino 0.5 weight partgroup is masked by hexamethylenediisocyanate:______________________________________
The above compounds were dissolved in methyl ethyl ketone and methanol, thereby the varnish having 60 weight % of involatile content was prepared.
EXAMPLE 2
A varnish was prepared in substantially the same manner as in Example 1 except that 2 weight parts of biuret was used instead of urea.
EXAMPLE 3
A varnish was prepared in substantially the same manner as in Example 1, except that 2 weight parts of 1, γ-carbamylpropyl-triethoxysilane was used instead of urea.
EXAMPLE 4
A varnish was prepared in substantially the same manner as in Example 1, except that 30 weight parts of cresol novolak instead of phenol novolak and 5 weight parts of guanylurea instead of urea were used.
EXAMPLE 5
A varnish was prepared in substantially the same manner as in Example 1, except that 35 weight parts of bisphenol A novolak instead of phenol novolak and 3 weight parts of biuret instead of urea were used.
EXAMPLE 6
A varnish was prepared in substantially the same manner as in Example 1, except that 25 weight parts of polyvinylphenol instead of phenol novolak and 1 weight parts of γ-carbamylpropylethoxysilane instead of phenol novolak were used.
COMPARATIVE EXAMPLE 1
A varnish was prepared in substantially the same manner as in Example 1, except that urea was not used.
COMPARATIVE EXAMPLE 2
A varnish was prepared in substantially the same manner as in Example 1, except that 3 weight parts of 2-ethyl-4-methylimidazole whose imino group was masked by hexamethylene diisocyanate instead of 1, 2-ethyl-4methylimidazole of 0.3 weight parts was used.
COMPARATIVE EXAMPLE 3
A varnish was prepared in substantially the same manner as in Example 1, except that 4 weight parts of dicyandiamide was used instead of phenolnovolak. Further, ethyleneglycol-monomethylether was added as the solvent.
Prepreg were prepared by impregnating glass cloths of 0.1 mm in thickness with the varnish obtained in Examples 1 to 6 and Comparative Examples 1 to 3 followed by heating for five minutes at 140° C. By using three prepregs and two copper foils each having 35 μm in thickness, a copper-clad laminate (MCL) was produced under the conditions of 170° C., 60 minutes and 50 kg/cm 2 . After the MCL had been treated to be provided with an inner layered circuit, 6-layered circuit board was produced by using three plys of MCL and six plys of prepregs. The above 6-layered circuit board was examined in the point of drilling property, heat resistance in atmosphere, peeling resistance of copper foil, and thermal resistance to soldering. Further, to evaluate the storing stability of the prepreg, the change of the prepreg gelation time with the passage of time was examined. The result is shown Table 1.
TABLE 1__________________________________________________________________________ Example Comparative Example 1 2 3 4 5 6 1 2 3__________________________________________________________________________Occurrence 5,000 Upper 3.5 2.8 2.3 1.5 2.7 1.7 1.8 3.8 18.8ratio of hits Lower 4.1 3.1 1.9 2.0 2.0 2.1 2.5 3.9 17.1smears (%) 10,000 Upper 6.2 5.3 3.6 4.5 3.1 2.3 4.4 5.6 29.3 hits Lower 6.9 6.5 5.1 3.8 2.5 2.8 4.9 7.1 28.7Peeling resistance Outer Normal condition 1.9 1.8 2.1 2.0 2.1 1.9 1.4 1.9 2.1of copper foil layer Resistance to hydrochloric acid 1.8 1.7 2.0 1.9 1.8 1.8 0.7 1.7 1.9(kgf/cm) Inner Normal condition 1.2 1.1 1.2 1.1 1.0 1.2 0.8 1.2 1.3 layer Resistance to hydrochloric acid 1.0 0.9 1.1 1.0 0.9 1.0 0.4 1.0 1.1Thermal resistance Normal condition OK OK OK OK OK OK OK OK OKto soldering D-2/100 OK OK OK OK OK OK OK OK OKHeat resistance in atmosphere 170° C. (hr) 1100 900 1000 1000 800 1200 1200 1000 400Prepreg gelation Initial period 165 148 163 178 153 147 160 148 235time (second) After 60 days 156 127 158 165 145 139 153 111 226__________________________________________________________________________
Note (1) Evaluation for the occurrence of smears
After the through holes of 6-layered circuit board had been plated, observation by a microscope was conducted for the connection portion of the inner layered copper of 20 holes in proximity of 5000 hits and 10000 hits and the plated copper of the through holes, thereby the occurrence ratio of the smears was examined. The average occurrence ratio of the smears was made by calculating the ratio of height of each smear relative to each connection height followed by averaging.
Note (2)
Measurement of peeling resistance of an outer layered copper foil:
By forming a line of 1 mm in width on the outer layered copper foil, the peeling resistance in a direction of 90° on the line was measured by means of the peeling speed of 50 mm/min.
Measurement of peeling resistance of inner layered copper foil:
By providing the glossy surface of the inner layered copper foil with roughening treatment and copper oxide treatment, the peeling resistance to peeling between the copper oxide treated surface and the prepreg layer was measured by the same conditions.
Treatment by hydrochloric acid:
The MCL on which a line of 1 mm in width was formed was dipped for 60 minutes in 18% hydrochloric acid at 35° C.
Note (3) Thermal resistance to soldering
The test piece was dipped for 20 seconds in a solder of 260° C. Then, by visual eyes, no-expanded test piece was accepted (OK), but expanded one was not accepted (NG).
Note (4) Heat resistance in atmosphere
The MCL treated by etching was heated for a long time at a temperature of 170° C. in a dryer. The flexural resistance was measured every 100 hours. When it is less than one-half of the flexural resistance measured before the treatment, the treatment time was shown in Table.
Note (5) Gelation time of prepreg
By setting as an initial rate the gelation time at 160° C. of the prepreg immediately after impregnating, after the prepreg had been stored for 60 days under the conditions of 20° C. in temperature 40% in humidity, the gelation time at 160° C. of the prepreg was measured.
When urea derivative was not used, as shown in Comparative Example 1, the drilling property was good, but the peeling resistance of copper foil became low. Further, when the masked imidazole compound was not used, as shown in Compartive Example 2, the change of the gelation time of the prepreg with the passage of time was large and its storing stability became inferior. Further, when the hardener was replaced by dicyandiamide as shown in Comparative Example 3, the occurrence ratio of smears was frequent and the drilling property became worse.
EXAMPLE 7
______________________________________Brominated bisphenol A type epoxy resin 80 weight parts(Epoxy equivalent 530)Phenol novolak type epoxy resin 20 weight parts(Epoxy equivalent 200)Phenol novolak resin 30 weight partsAcetamide 2 weight parts2-ethyl-4-methylimidazole whose imino group 0.5 weight partwas masked by hexamethylene diisocyanate:______________________________________
The above compounds were dissolved in methyl ethyl ketone, to prepare the varnish of 60 weight % involatile content.
EXAMPLE 8
A varnish was prepared in substantially the same manner as in Example 6, except that 2 weight parts of benzamide was used instead of acetamide.
EXAMPLE 9
A varnish was prepared in substantially the same manner as in Example 6, except that 2 weight parts of formamide was used instead of acetamide.
EXAMPLE 10
A varnish was prepared in substantially the same manner as in Example 6, except that 2 weight parts of benzanilide was used instead of acetamide.
EXAMPLE 11
A varnish was prepared in substantially the same manner as in Example 6, except that 2 weight parts of acetochloroamide was used instead of acetamide.
EXAMPLE 12
A varnish was prepared in substantially the same manner as in Example 7, except that 30 weight parts of cresol novolak instead of phenol novolak and 3 weight parts of formamide instead of acetamide were used.
EXAMPLE 13
A varnish was prepared in substantially the same manner as in Example 7, except that 35 weight parts of bisphenol-A novolak instead of phenol novolak instead of acetamide, and 5 weight parts of acetamide instead of 2 weight parts of acetamide were used.
COMPARATIVE EXAMPLE 4
A varnish was prepared in substantially the same manner as in Example 7, except that 0.3 weight parts of 7, 2-ethyl -4-methylimidazole was used instead of 2-ethyl-4-methylimidazole whose imino group was masked by hexamethylene diisocyanate in Example of 0.3 weight parts was compounded.
COMPARATIVE EXAMPLE 5
A varnish was prepared in substantially the same manner as in Example 7, except that 4 weight parts of dicyandiamide was used instead of phenol novolak resin and ethyleneglycol-monomethylether was further added.
Like Examples 1 to 6, MCL plys were made with the varnishs obtained in Examples 7 to 13 and Comparative Examples 4 and 5, and then their performance test was conducted. The result was shown in Table 2. MCL plys prepared by the use of the acid amide compounds also showed the same tendency like these prepared by the use of the urea compounds.
TABLE 2__________________________________________________________________________ Comparative Example Example 7 8 9 10 11 12 13 4 5__________________________________________________________________________Occurrence 5,000 Upper 3.1 3.9 2.3 2.8 3.0 2.9 4.0 4.1 18.8ratio of hits Lower 2.4 4.0 4.1 3.3 2.1 2.6 1.8 2.9 17.1smears (%) 10,000 Upper 5.8 6.5 5.5 4.7 8.1 3.3 5.3 6.6 29.3 hits Lower 7.0 6.0 8.2 7.2 6.6 3.9 4.9 7.2 28.7Peeling resistance Outer Normal condition 1.9 2.0 2.0 1.8 1.9 1.9 2.0 1.9 2.1of copper foil layer Resistance to hydrochloric acid 1.8 1.8 1.8 1.6 1.7 1.8 1.9 1.7 1.9(kgf/cm) Inner Normal condition 1.2 1.0 1.0 1.0 1.1 1.1 1.0 1.1 1.3 layer Resistance to hydrochloric acid 1.0 0.9 0.9 0.8 0.9 1.0 1.0 0.9 1.1Thermal resistance Normal condition OK OK OK OK OK OK OK OK OKto soldering D-2/100 OK OK OK OK OK OK OK OK OKHeat resistance in atmosphere 170° C. (hr) 800 900 1000 900 900 1000 900 900 400Prepreg gelation Initial period 158 165 149 148 150 163 147 155 235time (second) After 60 days 149 151 130 137 140 156 140 109 226__________________________________________________________________________
EXAMPLE 14
______________________________________Brominated bisphenol A type epoxy resin 80 weight parts(Epoxy equivalent 530)Phenol novolak type epoxy resin 20 weight parts(Epoxy equivalent 200)Phenol novolak resin 30 weight partso-tolylbiguanide 2 weight partsγ-glycidoxypropyltrimethoxysilane 2 weight parts1-cyanoethyl-2-phenylimidazole 0.2 weight part______________________________________
The above compounds were dissolved in methyl ethyl ketone to obtain the varnish having 60 weight % involatile content was prepared. A prepreg was obtained by impregnating a glass cloth of 0.1 mm in thickness with this varnish followed by drying for 5 minites at 130° C.
EXAMPLE 15
A varnish was prepared in substantially the same manner as in Example 14, except that 2 weight parts of guanidine carbonate was used instead of o-tolylbiguanide.
EXAMPLE 16
A varnish was prepared in substantially the same manner as in Example 14, except that 5 weight parts of 1,3-di-o-tolylguanidine was used instead of o-tolybiguanide.
EXAMPLE 17
A varnish was prepared in substantially the same manner as in Example 14, except that 1 weight part of γ-mercaptopropylmethyldimethoxysilane was used instead of γ-glycidoxypropyltrimethoxysilane.
EXAMPLE 18
A varnish was prepared in substantially the same manner as in Example 14, except that 1 weight part of tetraoctyl bis(ditridecylphosphite)titanate was used instead of γ-glycidoxypropyltrimethoxysilane.
COMPARATIVE EXAMPLE 6
A varnish was prepared in substantially the same manner as in Example 14, except that both o-toylbiguanide and γ-glycidoxypropyltrimetoxysilane were not used.
COMPARATIVE EXAMPLE 7
A varnish was prepared in substantially the same manner as in Example 14, except that o-tolylbiguanide was not used.
COMPARATIVE EXAMPLE 8
A varnish was prepared in substantially the same manner as in Example 14, except that γ-glycidoxytrimethoxysilane was not used.
COMPARATIVE EXAMPLE 9
A varnish was prepared in substantially the same manner as in Example 14, except that 2-phenylimidazole was used instead of 1-cyanoethyl-2-phenylimidazole.
COMPARATIVE EXAMPLE 10
A varnish was prepared in substantially the same manner as in Example 14, except that 4 weight parts of dicyandiamide was used instead of phenol novolak resin. In addition to methyl ethyl ketone in Comparative Example 1, N, N-dimethylformamide was used as the solvent. Drying was carried out for 5 minutes at 130° C. and then again for 5 minutes at 170° C.
By using three plys of prepregs obtained in Examples 14 to 18 and Comparative Examples 6 to 10 and two plys of copper foils each having 35 μm in thickness, copper-clad laminates (MCL) were prepared under the conditions of 170° C., 60 minutes and 50 kg/cm 2 . After providing MCL with an inner layered circuit, 6-layered circuit boards were prepared by using 3 sheets of MCL and 6 sheets of prepreg for each board. The properties of these 6-layered circuit boards were examined in the point of drilling property, heat resistance in atmosphere, peeling resistance of the copper foil, and thermal resistance to soldering. Further, to evaluate the storing stability of the prepregs, the change of gelation time of the prepreg with the passage of time was examined. The result was shown in Table 3.
TABLE 3__________________________________________________________________________ Example Comparative Example 14 15 16 17 18 6 7 8 9 10__________________________________________________________________________Occurrence 5,000 Upper 1.5 3.5 2.9 2.1 3.0 1.1 1.8 2.2 2.2 15.9ratio of hits Lower 2.6 1.9 2.5 2.7 3.3 2.3 2.5 1.9 2.9 16.1smears (%) 10,000 Upper 5.5 4.9 3.3 5.4 7.1 3.8 4.6 5.3 6.1 24.3 hits Lower 4.7 6.0 5.6 4.2 7.5 4.2 6.1 5.9 4.8 31.5Peeling resistance Outer Normal condition 2.0 1.9 2.1 2.0 1.8 1.4 2.0 1.5 2.0 2.1of copper foil layer Resistance to hydrochloric acid 1.9 1.9 2.0 2.0 1.7 0.6 0.6 1.3 1.9 2.0(kgf/cm) Inner Normal condition 1.2 1.3 1.2 1.2 1.0 0.8 1.2 1.0 1.2 1.3 layer Resistance to hydrochloric acid 1.0 1.1 1.1 1.0 0.8 0.3 0.4 0.8 1.0 1.1Thermal Normal condition OK OK OK OK OK OK OK OK OK OKresistance D-2/100 OK OK OK OK OK OK OK OK OK OKto solderingHeat resistance in atmosphere 170° C. (hr) 1000 900 1000 900 800 1200 1100 900 1000 500Prepreg gelation Initial period 158 155 159 135 148 168 165 155 153 230time (second) After 60 days 145 150 153 121 133 160 161 141 108 215__________________________________________________________________________
When the coupling agent was not used as shown in Comparative Examples 6 to 8, the peeling resistance of the copper foil was not improved, while when the guanidine derivative was not used, the rate after the hydrochloric acid treatment was not improved. Further, as shown in Comparative Example 9, when the imidazole whose imino group was not masked, the change of the prepreg gelation time with passage of time was large and its storing stability was inferior. Further, when dicyandiamide was used without using the multi-functional phenol as a hardener, a large number of smears occurred and the heat resistance in atmosphere was inferior. | An epoxy resin composition for a copper-clad laminate comprising an epoxy resin having at least two epoxy groups in one molecule, a phenolic compound having at least two functional groups in one molecule as a hardener, an imidazole compound having a masked imino group as a hardening accelerator, and one or more of nitrogen compounds selected from the group consisting of urea derivatives represented by the formula R 1 --NH--CO--NH 2 , wherein R 1 is hydrogen or an organic group; acid amide compounds; and guanidine derivatives, which is advantageously used for the material of a copper-clad laminate. Accordingly, the copper-clad laminate is especially used for the production of printed circuit boards, and its drilling property, peeling resistance of the copper foil, adhesive property, and heat resistance are improved remarkably. In addition, this epoxy resin composition has an excellent storing stability. | 2 |
BACKGROUND OF THE INVENTION
The production of ring laser gyroscopes, as currently practiced, has involved the use of frame blanks made from glass-ceramics. Extensive machining of those frames (drilling gain bores, wells, anode and cathode ports, and fill holes to provide an optical gyroscope support containing internal channels for helium-neon gas encapsulation, and optically finishing edges for prism and mirror attachments) is quite apparently a very expensive and time consuming practice.
Therefore, the primary objective of the present invention was to design a method for producing such frames wherein the drilling would be eliminated and finishing would be limited to the optically contacted surfaces.
SUMMARY OF THE INVENTION
A ring laser gyroscope has a plane of mirror symmetry passing through all of the drilled holes. Accordingly, I questioned whether it might be possible to accomplish the above objective by forming two halves of the frame along this plane of symmetry and thereafter bonding the two halves into an integral unit. Because of the environments to which ring laser gyroscopes may be exposed, it seemed that the two halves should consist of a glass-ceramic and those two halves should be bonded together by means of a thermally crystallizable glass frit. Hence, in view of the fact that a glass-ceramic article is prepared through the controlled heat treatment of a precursor glass body, the two halves could be formed into a desired shape as glasses, which would then be subjected to the necessary heat treatment to crystallize the glass halves in situ to glass-ceramics. And, inasmuch as the final dimensions of the resulting glass-ceramic halves can be quite carefully controlled, further finishing would be essentially limited to the optically contacted surfaces. However, in order to successfully accomplish the proposed inventive method, the materials to be used therein must satisfy a number of critical requirements. To illustrate:
First, the frame material must exhibit a very low linear coefficient of thermal expansion (less than 1×10 -7 /°C. over the temperature range of -50° to +100° C.) where the gyroscope will be used in navigation applications;
Second, the frame material must be transparent in order to permit inspection;
Third, because the frame halves will most preferably be formed by pressing, the frame material must demonstrate melting and viscosity characteristics which permit gobbing of molten glass and pressing in a mold;
Fourth, the frame material (as a glass-ceramic) must be capable of being heated to frit bonding temperatures without manifesting any substantial change in thermal expansion;
Fifth, the thermal expansion of the frit (as crystallized) must be relatively close to that of the glass-ceramic frame material;
Sixth, the frit (as a glass) must flow sufficiently well to provide a hermetic seal at temperatures within the stability range of the glass-ceramic frame material; and
Seventh, the frit (as crystallized) must be essentially impermeable to helium gas.
Because of the very demanding melting and viscosity characteristics which must be exhibited in the precursor glass plus the extremely vital physical properties that must be demonstrated in the glass-ceramic, particularly the critically low coefficient of thermal expansion, it was determined that the glass-ceramic halves should be prepared from compositions described in U.S. Pat. No. 4,707,458. The glass-ceramics disclosed in that patent contain β-quartz solid solution as essentially the sole crystal phase and consist essentially, expressed in terms of percent weight on the oxide basis, of
______________________________________SiO.sub.2 64-67 ZnO 0.7-4.2Al.sub.2 O.sub.3 21-24 TiO.sub.2 2.0-3.25Li.sub.2 O 2.6-3.7 ZrO.sub.2 1.25-2.5MgO 0.5-1.5 TiO.sub.2 + ZrO.sub.2 4-5.25BaO 0-1 As.sub.2 O.sub.3 0-1______________________________________
The precursor glass bodies prepared from those compositions are crystallized in situ to glass-ceramics by first heating to about 700° -750° C. to develop nuclei therein and then further heating the nucleated body to about 800°-850° C. to grow crystals of β-quartz solid solution on the nuclei.
One glass-ceramic having a composition encompassed within that patent which appears to be especially desirable for use as gyroscope frame parts is Corning Code 9600, marketed by Corning Incorporated, Corning, N.Y., which has the following approximate composition, expressed in terms of weight percent on the oxide basis:
______________________________________SiO.sub.2 65.9 ZnO 1.6Al.sub.2 O.sub.3 21.7 TiO.sub.2 2.7Li.sub.2 O 3.3 ZrO.sub.2 1.7MgO 1.3 As.sub.2 O.sub.3 0.7BaO 0.8______________________________________
In order to discover a frit suitable for bonding two halves of a gyroscope frame together formed from glass-ceramic included within U.S. Pat. No. 4,707,458, the following two experiments were devised for testing the capability of various frit compositions:
In the first experiment, a plate of Corning Code 9600 glass-ceramic was polished, as was one end of a 96% silica glass tube marketed by Corning Incorporated under the o trademark VYCOR®. The frit to be tested was admixed into an organic vehicle (desirably #175 pine oil or #324 squeege oil from Drakenfeld Color Company, Washington, Pa.) to form a frit slip and that slip was applied to the polished end of the VYCOR® tube by dipping that end thereinto. The tube was then placed in an upright position onto the polished surface of the glass-ceramic plate with the coated end downward, and a weight placed atop the other end of the tube to assure tight contact with the glass-ceramic surface. That assembly was introduced into an electrically-fired, air atmosphere furnace and heated at a rate of about 300° C./hour to 750° C. (that temperature being sufficiently low to have essentially no effect upon the thermal expansion of the glass-ceramic). After maintaining that temperature for one-half hour to form a seal, the electric current to the furnace was cut off and the furnace allowed to cool to room temperature with the assembly retained therewith.
The assembly was withdrawn from the furnace and the weight removed from atop the tube. The open end of the tube was connected to the analyzer of a mass spectrometer through a graded seal and a helium filled bag was then attached around the outside of the assembly in such a manner as to form an enclosure therefor. Vacuum was thereafter applied to the tube and the level of helium coming into the analyzer measured. That experiment demonstrated that the seal was hermetic and the helium permeability was no higher than the glass tube.
In the second experiment, one member of Corning Code 7971, a glass marketed by Corning Incorporated under the trademark ULE fused silica glass, was bonded between two members of Corning Code 9600 glass-ceramic through the frit to be tested. Corning Code 7971 glass has the approximate analysis of 92.5% SiO 2 and 7.5% TiO 2 and exhibits a linear coefficient of thermal expansion (0°-300° C.) of about 0.3× 10 -7 /°C. The thermal expansion of the two glass-ceramic outer members was determined by measuring the stress in the glass inner member resulting from temperature changes. The purpose of the experiment was to ascertain whether the temperature required to assure a sound frit seal exerts any substantial effect upon the thermal expansion of the glass-ceramic.
I have found that above-stated requirements for a frit to be operable in bonding together parts of gyroscope frames prepared from glass-ceramic described in U.S. Pat. No. 4,707,458, while exhibiting very low permeability to helium gas, can be achieved in certain thermally crystallizable glass frit compositions within the PbO-TiO 2 -Al 2 O 3 -B 2 O 3 -SiO 2 system. Thus, the operable frits have compositions consisting essentially, expressed in terms of weight percent in the oxide basis, of about 62-68% PbO, 12-20% TiO 2 , 1-3% Al 2 O 3 , 1-3% B 2 O 3 , and 12-18% SiO 2 . When fired to a temperature between about 700°-800° C. to sinter the frit particles together into an integral mass, in situ crystallization occurs within the mass, this crystallization consisting predominantly of a lead titanate phase having a perovskite-type structure. Firing times of as little as 0.25 hour may be sufficient, but safer practice to assure sound bonding and a high percentage of crystallinity dictates sintering periods of up to 3 hours, depending upon the temperatures employed, with about 0.5-2 hours being preferred. Hence, the precursor glass demonstrates a high linear coefficient of thermal expansion but, when highly crystallized, the material exhibits a linear coefficient of thermal expansion (0°- 300° C.) less than 30×10 -7 /°C. Accordingly, the sintering heat treatment will be continued for a sufficient period of time to achieve high crystallinity, commonly >50% by volume.
In general terms, my inventive method comprises five basic steps:
(1) members of such predetermined configurations that, when sealed together, they will form a ring laser gyroscope frame are prepared from a glass-ceramic having a composition encompassed within U.S. Pat. No. 4,707,458;
(2) a coating of a thermally devitrifiable frit having a composition within the above-described ranges is applied onto the surfaces of the members that are to be sealed together;
(3) the frit coated surfaces of the members are brought into contact with each other;
(4) at least the frit coated, contacting surfaces of the members are heated to a temperature between about 700°-800° C. for a sufficient length of time to form a fusion seal between the contacting surfaces, thereby producing an integral body (a ring laser gyroscope frame), and to effect the in situ crystallization of lead titanate crystals in the seal; and then
(5) cooling the body to room temperature.
The article produced from my inventive method comprises a ring laser gyroscope frame composed of individual preformed members prepared from glass-ceramics consisting essentially of a composition included within U.S. Pat. No. 4,707,458 which are fusion sealed into an integral body through a thermally devitrifiable frit consisting essentially of a composition within the above-described ranges which, during fusion sealing, crystallizes in situ to lead titanate crystals having a perovskite-type structure.
PRIOR ART
U.S. Pat. No. 3,486,871 discloses thermally devitrifiable frit sealing glasses in which, upon sintering, lead titanate crystals having a perovskite-type structure are developed in situ. Those glasses consisted essentially, in weight percent, of 60-80% PbO, 5-18% TiO 2 , at least 1% B 2 O 3 , at least 5% SiO 2 , the total B 2 O 3 +SiO 2 being 10-20%, and 0-2% Al 2 O 3 . The frits could be sintered into a fusion seal at temperatures of 500°-650° C. The coefficients of thermal expansion (0°-300° C.) reported for the working examples ranged over 48-70×10 -7 /°C. Therefore, although there is apparent overlap in the composition intervals disclosed in the patent and those of the frits operable in the present invention, the low sintering temperatures evidence basic differences existing between the frits of the patent and those operable in the instant invention. Furthermore, and most importantly, no mention is made of joining together parts of ring laser gyroscope frames using a sealing frit. Yet, that is the very crux of the present invention.
U.S. Pat. No. 3,663,244 describes enamels for decorating glass-ceramic articles, which enamels are prepared from thermally devitrifiable glass frits which, upon sintering, crystallize in situ to form lead titanate crystals having a perovskite-type structure. The frits consisted essentially, in weight percent, of 62-68% PbO, 12-16% TiO 2 , 14-20% SiO 2 , 2-4% Al 2 O 3 , and up to 2% total of one or more oxides selected from the group of B 2 O 3 , BaO, P 2 O 5 , and ZnO. The frits could be matured into a glaze by firing at a temperature between about 700°-850° C. The linear coefficients of thermal expansion (0°-300° C.) were stated to range about 15-30×10 -7 /°C. Again, there is overlap between the composition intervals disclosed in the patent and those operable in the instant invention. But also again, however, there is no reference to frit bonding together parts of ring laser gyroscope frames and the physical properties such frits must demonstrate to perform that function.
DESCRIPTION OF PREFERRED EMBODIMENTS
The table below records the compositions, expressed in terms of parts by weight on the oxide basis, of two glass frits which are operable in the present invention. Inasmuch as the sum of the individual components totals or very closely approximates 100, for all practical purposes the values reported in the table ma be deemed to reflect weight percent. The actual batch ingredients may comprise any materials, either oxides or other compounds, which, when melted together, will be converted into the desired oxide in the proper proportions. For example, H 3 BO 3 may constitute the source of B 2 O 3 .
The batch materials were compounded, carefully mixed together, and charged into platinum crucibles. The crucibles were introduced into a furnace operating at about 1200°-1300° C. and the batches were melted for about 1-3 hours. The molten glass was "cocktail mixed" six times, i.e., the molten glass was poured from one crucible into another and back again six times, and then poured as a stream into a container of water to form small particles of glass. This latter practice is termed "drigaging" in the art. Thereafter, those glass particles were dried and subsequently milled to powder having an average grain size of less than 10 microns.
______________________________________ 1 2______________________________________PbO 64 65.3TiO.sub.2 16 18.1SiO.sub.2 16 12.4Al.sub.2 O.sub.3 2 1.98B.sub.2 O.sub.3 2 1.57______________________________________
Example 1 exhibited a linear coefficient of thermal expansion (0°-300° C.) of about 28×10 -7 /°C. and Example 2 demonstrated a linear coefficient of thermal expansion (0°-300° C.) of about 18×10 -7 /°C.
A slip was prepared from each powder, termed frit, by admixing the frit into #175 pine oil by Drakenfeld in proportions of 4.5 parts of vehicle to 25 parts of frit. After only a few minutes of hand mixing, the frit was uniformly dispersed within the vehicle and the viscosity of the slip was at a level to allow easy manual spreading, but sufficiently thick to inhibit substantial spontaneous flow. The slip can then be applied as a thin layer via a spatula to the gyroscope frame parts fashioned from Corning Code 9600 glass-ceramic. (It will be appreciated that layers of more precise dimensions can be prepared through such means as doctor blading, dipping, silk screening, and spraying, and the viscosity of the slip for use in such means will be adjusted therefor.) A preliminary flat grinding of the frame surfaces can be advantageous in assuring an even contact along the surfaces of the parts. A gentle abrasion of the frame surface prior to applying the slip may also be useful in assuring good bonding. The coated frame parts will be brought together in proper alignment; e.g., they can be mounted and held in a jig constructed of materials capable of resisting high temperatures such as stainless steel or a super alloy. That assembly will then be moved into an electrically heated kiln and fired at temperatures between about 750°-780° C. for about 0.5 hour to cause the frit to flow and to concurrently develop in situ a high percentage of lead titanate crystals exhibiting a perovskite structure, thereby resulting in a hermetic seal between the frame parts. The application of some pressure on the parts during firing may be helpful in securing good bonding. One especially effective firing schedule is set out below:
Heat from room temperature to 780° C. at 60° C./hour
Hold at 780° C. for one hour
Cool from 780° C. to 500° C. at 150° C./hour
Cut off electric current and allow kiln to cool with assembly therein
A final finishing to trim sprues, remove any traces of flash from the bonding frit, etc., may be necessary to assure very accurate dimensional and shape control, as well as the optically contacted surfaces.
When subjected to the above-described experiment for determining the resistance to permeability of helium gas, the hermetic seal to the VYCOR® tube made by Example 1 passed helium at a rate no faster than the VYCOR® tube itself. When expressly tested for helium gas permeability, a pressed and fired disc of Example 2 demonstrated a performance quite comparable to that of Corning Code 9600 glass-ceramic.
When subjected to the above-described experiment for determining whether the frit bonding schedule affected the thermal expansion of Corning Code 9600 glass-ceramic, no substantial effect was observed. | This invention provides a method for forming ring laser gyroscope frames without extensive machining. Parts of necessary configurations for such frames are so fashioned that they can be sealed together into a unit. Those parts are prepared from very low expansion glass-ceramics of particular compositions and are sealed together with low expansion, thermally devitrifiable sealing glasses, also of particular compositions. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to saw machines and more particularly, to a workpiece feeding device for saw machines that has angle detection means to detect the cutting angle.
[0003] 2. Description of the Related Art
[0004] A conventional table saw is known comprising a machine base, a saw blade holder mounted on the machine base and holding a saw blade and a motor, a horizontal displacement mechanism mounted on the machine base and movable horizontally relative to the machine base and the saw blade holder, an angle adjustment device provided at the horizontal displacement mechanism and adapted for adjusting the cutting angle of the workpiece relative to the saw blade, and an angle scale located on the angle adjustment device for enabling the user to read the cutting angle. When the user is operating the table saw to cut a wooden workpiece, the user can adjust and set the biasing angle subject to the angle scale at the angle adjustment device and subject to the desired shape and size, obtaining the desired cutting angle of the workpiece relative to the saw blade.
[0005] However, the angle scale of the aforesaid table saw is a simple rule, and the user must read the readings of the angle scale with the eyes. During cutting, the angle scale may be covered by the cut chips. At this time, the user must clean the angle scale. Further, the graduations may become vague after a long use of the table saw. Further, due to the limitation of the graduations of the angle scale, the angle scale cannot satisfy a precision requirement for fine cutting. Therefore, an improvement in this regard is necessary.
SUMMARY OF THE INVENTION
[0006] The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a workpiece feeding device for saw machine, which directly indicates the cutting angle for reading by the user to facilitate sawing operation.
[0007] To achieve this and other objects of the present invention, the workpiece feeding device is used in a saw machine comprising a machine base and a saw blade. The workpiece feeding device comprises a carrier, which comprises a base frame provided at one side of the machine base of the saw and movable relative to the machine base and an angle scale fastened to the base frame. a fence unit, which comprises a rip fence pivotally mounted on the base frame of the carrier and biasable relative to the angle scale, a magnetic plate assembly mounted on the base frame of the carrier and carrying a magnetic strip, and a magnetic sensor mounted in the fence unit and spaced from said magnetic strip of the magnetic plate assembly at a predetermined distance. The magnetic sensor is movable with the fence unit to change the angular position thereof relative to the magnetic plate assembly and to measure the biasing angle of the fence unit relative to the angle scale subject to change of magnetic induction between the magnetic sensor and the magnetic strip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an elevational view of a workpiece feeding device for use in a horizontal displacement mechanism of a saw machine according to the present invention.
[0009] FIG. 2 is a top view of FIG. 1 .
[0010] FIG. 3 is an exploded view of FIG. 1 .
[0011] FIG. 4 is an enlarged view of a part of FIG. 3 .
[0012] FIG. 5 is a sectional assembly view of a part of the workpiece feeding device according to the present invention.
[0013] FIG. 6 is a sectional view taken along line 6 - 6 of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to FIGS. 1˜6 , a workpiece feeding device with angle detection means in accordance with the present invention is shown installed in a saw machine (not shown) having a machine base and a saw blade mounted in the machine base. The workpiece feeding device comprises:
[0015] a carrier 10 , which comprises a base frame 11 provided at one side of the machine base of the saw and horizontally movable relative to the machine base, an angle scale 12 fastened to the base frame 11 at the top with screws and having angle graduations 121 marked thereon and a longitudinal slot 122 cut therethrough, a first guide block 123 mounted in the longitudinal slot 122 of the angle scale 12 , a second guide block 124 inserted through the first guide block 123 , a locating bolt 13 fastened to the second guide block 124 , a supplementary frame bar 14 mounted on the base frame 11 at the top and kept in flush with the top surface of the angle scale 12 , two calibration bolts 15 bilaterally mounted on the base frame 11 and disposed near one end of the base frame 11 , two locating plates 16 bilaterally mounted on the base frame 11 and disposed near the other end of the base frame 11 , each locating plate 16 having a coupling groove 161 mounted with bushing 162 and defining an opening 163 and a beveled edge 164 around the opening 163 ;
[0016] a magnetic plate assembly 20 , which comprises a plate member 21 that has its one side edge smoothly arched and a coupling flange 211 downwardly extended from the smoothly arched side edge and a through hole 212 cut through the top and bottom walls thereof, a bushing 23 mounted in the through hole 212 of the plate member 21 and defining an axial through hole 231 , and a magnetic strip 25 fastened to the smoothly arched side edge of the plate member 21 ;
[0017] a lock bolt 30 , which comprises a knob 31 located on its one end, an extension rod 33 forwardly extending from its other end, a screw hole 35 formed in the free end of the extension rod 33 , and a holding down portion 37 extending around the root of the extension rod 33 ;
[0018] a suspension arm 40 , which comprises a narrow elongated arm body 41 , a screw rod 45 perpendicularly located on one end of the arm body 41 and inserted into the through hole 231 of the bushing 23 of the magnetic plate assembly 20 and threaded into the screw hole 35 of the lock bolt 30 , and a guide block 47 located on the other end of the arm body 41 and having a T-shaped profile;
[0019] a magnetic sensor 50 , which comprises a substantially U-shaped clamping plate 51 affixed to the guide block 47 of the suspension arm 40 and a magnetic sensor element 53 fastened to the clamping plate 51 with screws;
[0020] a display unit 60 , which is mounted in the base frame 11 of the carrier 10 and, which comprises an electric circuit module (not shown) that is electrically connected with the magnetic sensor element 53 of the magnetic sensor 50 and provides a magnetic displacement measurement function, and a display module 61 for indicating the displacement data measured by the electric circuit module; and
[0021] a fence unit 70 , which comprises a rip fence 71 mounted on the base frame 11 of the carrier 10 , a length scale 72 located on the top side of the rip fence 71 , a sliding groove 73 of a T-shaped profile located on the bottom side of the rip fence 71 for receiving the guiding sliding movement of the guide block 47 of the suspension arm 40 to guide sliding movement of the suspension arm 40 .
[0022] The installation of the present invention is outlined thereinafter with reference to FIGS. 5 and 6 again, the second guide block 124 of the carrier 10 is inserted into the sliding groove 73 of the fence unit 70 and the locating bolt 13 fastened to the second guide block 124 such that when the rip fence 71 of the fence unit 70 is moved relative to the angle scale 12 , the position of the rip fence 71 is changed relative to the angle graduations 121 of the angle scale 12 , and a relative biasing angle is thus indicated.
[0023] Thereafter, the magnetic sensor 50 is fastened to the suspension arm 40 , and then the screw rod 45 of the suspension arm 40 is inserted into the through hole 231 of the bushing 23 of the magnetic plate assembly 20 and threaded into the screw hole 35 of the lock bolt 30 . At this time, the magnetic sensor element 53 of the magnetic sensor 50 is spaced from the magnetic strip 25 of the magnetic plate assembly 20 at a predetermined distance so that the magnetic sensor element 53 detect the magnetic force of the magnetic strip 25 , and there is a predetermined gap left between the holding down portion 37 of the lock bolt 30 and the coupling flange 211 of the magnetic plate assembly 20 .
[0024] Thereafter, the guide block 47 of the suspension arm 40 is coupled to the sliding groove 73 of the fence unit 70 , allowing movement of the suspension arm 40 , the magnetic plate assembly 20 and the lock bolt 30 along the sliding groove 73 of the fence unit 70 . Therefore, after installation of the fence unit 70 in one of the two locating plates 16 of the carrier 10 , the extension rod 33 of the lock bolt 30 can be moved into the opening 163 of the locating plate 16 , i.e., the lock bolt can be moved axially through a predetermined distance and then moved transversely into or away from the opening of the locating plate between the locking position and the unlocking position. Further, the coupling flange 211 of the plate member 21 of the magnetic plate assembly 20 is coupled to the coupling groove 161 of the locating plate 16 , and then rotate the knob 31 of the lock bolt 30 to force the holding down portion 37 into engagement with the beveled edge 164 of the respective locating plate 16 , allowing the suspension arm 40 to be turned relative to the magnetic plate assembly 20 .
[0025] The principle and operation procedure of the present invention are explained hereinafter. When biasing the fence unit 70 relative to the coupled locating plate 16 , the rip fence 71 is moved above the angle scale 12 and the supplementary frame bar 14 to turn the suspension arm 40 about the screw rod 45 . At this time, the magnetic sensor 50 detects a change of the value of magnetic induction relative to the magnetic strip 25 of the magnetic plate assembly 20 and sends the detection result to the circuit module of the display unit 60 , enabling the circuit module of the display unit 60 to calculate the amount of angular displacement and display the calculated value on display module 61 .
[0026] Further, after installation of the fence unit 70 in one of the two locating plates 16 of the carrier 10 , the angular position (90-degrees angular position) of the fence unit 70 relative to the angle scale 12 and the angular position (90-degrees angular position) of the magnetic sensor 50 relative to the magnetic plate assembly 20 can be calibrated based on the reference of the calibration bolt 15 . Further, the fence unit 70 can be biased inwards within the range of 90-degrees to 45-degrees to adjust the cutting angle of the workpiece.
[0027] Still further, when wishing to change the position of the fence unit 70 on the carrier 10 , loosen the lock bolt 30 , and then move the magnetic plate assembly 20 and the lock bolt 30 away from the corresponding locating plate 16 , and then couple the magnetic plate assembly 20 to the other locating plate 16 , and then fasten tight the lock bolt 30 to lock the fence unit 70 . Therefore, it is convenient to mount and dismount the fence unit 70 .
[0028] Further, axle bearings may be used to substitute for the aforesaid bushings, smoothening biasing of the suspension arm relative to the magnetic plate assembly.
[0029] By means of using the workpiece feeding device with angle detection means of the present invention in a saw machine, the user can adjust the cutting angle of the workpiece by means of adjusting the biasing angle of the fence unit. By means of reading the angle scale or the indication of the display unit, the user knows the cutting angle accurately, facilitating the sawing operation. | A workpiece feeding device used in a saw machine is disclosed to include a carrier having a base frame movably mounted on the machine base of the saw machine and an angle scale fastened to the base frame, a fence unit having a rip fence pivotally mounted on the base frame of the carrier and biasable relative to the angle scale, a magnetic plate assembly mounted on the base frame of the carrier and carrying a magnetic strip, and a magnetic sensor mounted in the fence unit and movable with the fence unit to measure the biasing angle of the fence unit relative to the angle scale subject to change of magnetic induction between the magnetic sensor and the magnetic strip. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of and is based upon and claims the benefit of priority under 35 U.S.C. §120 for U.S. Ser. No. 12/769,958, filed Apr. 29, 2010 which is a continuation of U.S. Ser. No. 12/250,306, filed Oct. 13, 2008 (now U.S. Pat. No. 7,746,759) which is a divisional of U.S. Ser. No. 11/338,644, filed Jan. 25, 2006 (now U.S. Pat. No. 7,646,700) which is a divisional of U.S. Ser. No. 09/898,389, filed Jul. 3, 2001 (now U.S. Pat. No. 7,221,645) and claims the benefit of priority from European Patent Application No. 00 114 423.7, filed Jul. 5, 2000, the entire contents of each of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a transmitting device and a receiving device of a wireless orthogonal frequency division multiplex (OFDM) communication system.
2. Description of the Related Art
In wireless telecommunication, the transmission quality between a transmitting device, such as a base station, and a receiving device, such as a mobile terminal, depends strongly on the respective transmission environment and is often deteriorated by fading effects and the like. This often leads to poor speech and data transmission quality, particularly if only one single antenna is used on the transmission side and one single antenna is used on the receiving side. Therefore, some mobile terminals for wireless telecommunication systems, such as the GSM system, comprise two or more and different kinds of antennas built as internal or external antennas in the mobile terminal. However, it is desirable that modern mobile terminals are as small and light as possible and therefore it is an increasing interest to use only a single antenna in these mobile terminals. In order to allow the use of only a single antenna on the receiving side, particularly the mobile terminal side, it has been proposed to use more than one antenna on the transmitting side, particularly the base station side, so that the diversity gain can be used for a better transmission quality. This scheme is called transmit diversity. Transmit diversity generally means that more than one antenna, e.g. two antennas, transmit data simultaneously to a receiving device. If the same data are transmitted in parallel by two antennas, the receiving side has a chance to receive signals at least from one of the antennas with an acceptable transmission quality so that a good connection can be ensured. One specific approach in the transmit diversity scheme is the use of a so-called space time coding. The resulting space time transmit diversity (STTD) has been adapted and is of the UMTS standard for the next generation of mobile telecommunication part
In a space time transmit diversity system, a transmitting device, such as a base station, comprises e.g. two antennas arranged spaced apart from each other in a space diversity arrangement. A stream of data to be transmitted to a receiving device, such as a mobile terminal, is encoded and processed so that two parallel data streams are generated. After further processing corresponding to the respective wireless communication system, the data of each of the two data streams are transmitted by a respective one of the two antennas. Although generally the same data content is transmitted by each of the two antennas, the signals transmitted by the two antennas are not absolutely identical, but data symbols to be transmitted are mapped or coded slightly differently on the signals transmitted by each of the antennas. This allows a receiving device receiving the signals transmitted from the two antennas with only a single antenna to distinguish and separate signals coming from one of the transmitting antennas from signals coming from the other of the transmitting antennas. Since the two transmitting antennas are arranged in a space diversity arrangement, cross interference is avoided and the receiving device can then, after a corresponding channel estimation, distinguish and combine the signals from the two transmitting antennas to obtain a better transmission quality. The channel estimation in the receiving device is usually performed on the basis of pilot symbols transmitted from the transmitting device. The receiving device performs a channel estimation by comparing received pilot symbols with an expected pilot symbol to measure the channel response and to tune the receiving device to the best transmission channel, i.e. the transmitting antenna to which the better connection exists.
The above-mentioned UMTS system bases on a code division multiple access (CDMA) scheme. The CDMA scheme is only one of several possible multiple access schemes used in wireless telecommunication. For wireless telecommunication with high data rates, the orthogonal frequency division multiplex (OFDM) scheme is known, in which the available frequency band used for a communication is divided in a plurality of frequency subcarriers, whereby adjacent frequency subcarriers are respectively orthogonal to each other.
SUMMARY OF THE INVENTION
The object of the present invention is now to propose a transmitting device, which allows a simple and effective channel estimation to be performed.
This object is achieved by a transmitting device according to the independent claims.
The present invention relates to a transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols,
means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system,
wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and
wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension.
The present invention further relates to a transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising
symbol generating means for generating said data symbols and said pilot symbols,
means for transmitting said data symbols and pilot symbols by using a plurality of subcarriers of said OFDM transmission system,
wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so as to create a pilot symbol pattern in which said first and second type pilot symbols are allocated respectively in said frequency dimension, and
wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension.
The present invention further relates to a transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising
symbol generating means for generating said data symbols and said pilot symbols,
means for transmitting said data symbols and pilot symbols by using a plurality of subcarriers of said OFDM transmission system,
wherein said symbol generating means is designed to regularly allocate either a first type pilot symbol or a second type pilot symbol being orthogonal to said first type pilot symbol in the frequency dimension to said generated pilot symbols.
The present invention further relates to a transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising
symbol generating means for generating said data symbols and said pilot symbols,
means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system,
wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the time dimension comprises at least said first and second type pilot symbols to be transmitted at different timepoints respectively,
wherein said pilot symbol pattern to be transmitted by using one of said plurality of subcarriers is different from a pilot symbol pattern to be transmitted by using an adjacent subcarrier.
The present invention further relates to a transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising
symbol generating means for generating said data symbols and said pilot symbols,
means for transmitting said data symbols and pilot symbols by using a plurality of subcarriers of said OFDM transmission system,
wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so as to create a pilot symbol pattern in which said first and second type pilot symbols are allocated regularly in the time dimension, and
wherein said pilot symbol pattern to be transmitted by using one of said plurality of subcarriers is different from a pilot symbol pattern to be transmitted by using an adjacent subcarrier.
The present invention further relates to a transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising
symbol generating means for generating said data symbols and said pilot symbols,
means for transmitting said data symbols and pilot symbols by using a plurality of subcarriers of said OFDM transmission system,
wherein a pilot symbol pattern, in which a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol are allocated in the time dimension, to be transmitted by using one of said plurality of subcarriers is different from a pilot symbol pattern to be transmitted by using an adjacent subcarrier.
Advantageously, corresponding first and second pilot symbols have the same frequency and time allocation in the OFDM system. In other words, corresponding first and second pilot symbols are transmitted in the same subcarrier and the same timeslot of the OFDM system. Hereby, further advantageously corresponding first and second pilot symbols having the same frequency and time allocation are alternatingly identical and orthogonal to each other in the frequency as well as in the time dimension. This means that in the frequency and time grid of the OFDM system, identical first and second pilot symbols and orthogonal first and second pilot symbols alternate with each other in the frequency as well as the time dimension.
Advantageously, pairs of first pilot symbols being adjacent in the time dimension are respectively orthogonal to the corresponding pairs of second pilot symbols.
Advantageously, pairs of first pilot symbols being adjacent in the frequency dimension are respectively orthogonal to the corresponding pairs of second pilot symbols.
Advantageously, the first and the second pilot symbols have a regular distribution in the time and the frequency dimension, whereby the second pilot symbols alternately have the identical and the inverse complex value of the corresponding first pilot symbol in the time as well as in the frequency dimension.
The proposed scheme of transmitting, receiving and processing first and second pilot symbols allows a simple and effective channel estimation processing to be performed on the receiving side so that a better coherent demodulation of the transmission channel can be performed to ensure the best transmission quality. In an advantageous aspect, the present invention ensures full space and time diversity. Further, no feedback information from the receiving side to the transmitting side is required and an improved data transmission capacity can be realised. Further, the proposed system is robust to transmission antenna failures and guarantees power amplifier balance on the transmitting side.
It has to be clarified at this point that the single antenna of a receiving device receives the first pilot symbols transmitted from the first antenna means and the second pilot symbols transmitted from the second antenna means of the transmitting device only as a combined or superimposed pilot symbol. In case that the first pilot symbol and the second pilot symbol transmitted in the same frequency subcarrier and the same timepoint are identical, the receiving device receives a combined pilot symbol comprising the superimposed identical first and second pilot symbol. In case that the first and second pilot symbol are orthogonal to each other, the receiving device receives a combined pilot symbol comprising the superimposed orthogonal first and second pilot symbol. In the receiving device, the transfer function of the first and the second pilot symbol, respectively, can therefore be separated so that the respective channel estimation for each of the two transmission antennas can be performed in a simple way.
Advantageously, the second pilot symbols alternatingly have the identical and the inverse complex value of the corresponding first pilot symbol in the time as well as in the frequency dimension, so that the processing and the channel estimation on the receiving side can be performed on a basis of a simple addition and subtraction calculation of the received pilot symbols. On the basis of the channel estimation result, both signals from the first antenna means and from the second antenna means of the transmitting device are further processed and used as the communication data in the receiving device.
The transmitting device according to the present invention can e.g. be implemented in the base station of an OFDM communication system or in a mobile terminal of an OFDM communication system.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following description, the present invention is explained in more detail in relation to the enclosed drawings, in which
FIG. 1 shows schematically a base station comprising a transmitting device according to the present invention,
FIG. 2 shows schematically a mobile terminal comprising a receiving device according to the present invention,
FIGS. 3A and 3B a first and a second example, respectively, of a pilot symbol pattern transmitted by a first antenna means of a transmitting device according to the present invention, and
FIGS. 4A and 4B a first and a second example, respectively, of a pilot symbol pattern transmitted by the second antenna means of the transmitting device according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 , the block diagram of a base station 1 of a wireless orthogonal frequency division multiplex (OFDM) communication system is shown, which comprises a transmitting device according to the present invention. It is to be understood that in FIG. 1 only elements important for the understanding of the present invention are shown. Further elements, such as coding means, modulation means, RF part and the like necessary for the operation of the base station are omitted for the sake of clarity.
The base station 1 comprises a first antenna 5 and a second antenna 6 being arranged spaced apart from each other, e.g. in a space diversity arrangement. In this case, the first antenna 5 may also be called a non-diversity antenna and the second antenna 6 can also be called a diversity antenna. The space diversity arrangement of the first antenna 5 and the second antenna 6 is so that the two antennas 5 and 6 are sufficiently separated in space, so that the signals transmitted by the first antenna 5 and the second antenna 6 , respectively, are uncorrelated and an effective diversity gain can be achieved on the receiving side.
Further, the base station 1 comprises a encoding means 3 for encoding a data stream, e.g. on the basis of a space time transmit diversity (STTD) scheme and outputting a first and a second STTD encoded data stream to a multiplexer 4 . The first STTD encoded data stream is to be transmitted via the first antenna 5 and the second STTD encoded data stream is to be transmitted via the second antenna 6 . Although the data transmitted from the first antenna 5 and the second antenna 6 are generally the same data, i.e. contain the data of the single data stream supplied to the encoding means 3 , the data are not transmitted identically by the two antennas 5 and 6 . For example, the data transmitted by the first antenna 5 identically correspond to the data arrangement of the single data stream supplied to the encoding means 3 . If, e.g. a first data symbol S 1 in a time period 0-T and a second data symbol S 2 in the succeeding time period T-2T are supplied to the encoding means 3 , the first data stream output by the encoding means can identically correspond to that arrangement (data symbol S 1 followed by data symbol S 2 ). The second data stream output by the encoding means 3 , however, contains the data symbols S 1 and S 2 in a different arrangement. For example, as shown in FIG. 1 , in the second data stream, the data symbol of the first time period 0-T could be the negative complex conjugated value of the second data block S 2 of the first data stream, i.e. −S* 2 . The next succeeding data symbol of the second data stream is the conjugated complex value of the first data symbol S 1 of the first data stream, i.e. S* 1 . Thus, the second data stream contains the identical data content as the first data stream, but in a different arrangement. A receiving device receiving the signals from the first antenna 5 and the second antenna 6 as superimposed signals is therefore able to clearly distinguish between the signals transmitted from the first antenna 5 and the signals transmitted from the second antenna 6 due to the space diversity arrangement and the different arrangement of the same data content. It is to be understood that the space time transmit diversity scheme shown in and explained in relation to FIG. 1 only serves as an example to explain the present invention. Any other STTD scheme for transmitting data via the first antenna 5 and the second antenna 6 can be applied.
The base station 1 further comprises a pilot symbol generating means 2 for generating pilot symbols to be transmitted among the data of the first and the second data stream by the first antenna 5 and the second antenna 6 . Thereby, the pilot symbol generating means 2 generates and supplies different pilot symbol patterns to be transmitted via the first antenna 5 and the second antenna 6 , respectively, to the multiplexer 4 . The general idea of the present invention is that some of the pilot symbols transmitted by the first antenna 5 and the second antenna 6 are orthogonal to each other so that the cross-interference from both antennas 5 and 6 is eliminated, the signals from the first, (non-diversity) antenna 5 and the second (diversity) antenna 6 can be differentiated and consequently a separate channel estimation for each antenna 5 , 6 can be achieved in a receiving device.
FIG. 2 shows a schematic block diagram of a mobile terminal 10 comprising a receiving device for receiving signals in a wireless OFDM communication system according to the present invention. Particularly, the mobile terminal 10 is adapted to receive signals from a base station 1 as shown in FIG. 1 .
The mobile terminal 10 comprises a single antenna 11 for receiving STTD encoded signals as well as pilot symbols transmitted from the first antenna 5 and the second antenna 6 of the base station 1 . Further, the mobile terminal 10 comprises a receiving means 12 , which comprises e.g. the necessary RF part and the like. Further, the mobile terminal 10 comprises a demodulation means for demodulating signals received by the receiving means 12 via the antenna 11 . It is to be understood that the mobile terminal 10 further comprises all necessary elements to be operated in the corresponding wireless OFDM system. However, these elements are not shown for the sake of clarity.
The mobile terminal 10 further comprises a processing means 14 for detecting pilot symbols in the signals received by the receiving means 12 via the antenna 11 . The processing means 14 processes detected pilot symbols and performs a channel estimation on the basis of the processing to separately determine the transmission quality of the received signals transmitted from the first antenna 5 and the second antenna 6 , respectively. In other words, by processing the received pilot symbols, which are combined pilot symbols comprising the first and the second pilot symbols simultaneously transmitted by the first antenna 5 and the second antenna 6 , the processing means 14 is able to separately determine the transmission quality of the signals transmitted from the first antenna 5 and the transmission quality of the signals transmitted from the second antenna 6 . On the basis of this channel estimation result, both the STTD encoded signals from the first antenna 5 and from the second antenna 6 are further processed and used as communication data in the mobile terminal 10 .
As stated above, at least some of the second pilot symbols transmitted from the second antenna 6 are orthogonal to corresponding first pilot symbols transmitted by the antenna 5 . The processing performed in the processing means 14 bases on this orthogonality of the first and the second pilot symbols and enables the separate channel estimation for the first and the second antenna 5 and 6 , respectively. In relation to FIGS. 3 and 4 , a specific example for pilot symbol patterns to be transmitted by the base station 1 and to be received and processed in the mobile terminal 10 are proposed.
FIG. 3 comprises two FIGS. 3A and 3B . FIG. 3A shows a first example of a pilot symbol pattern to be transmitted by the first (non-diversity) antenna 5 of the base station 1 . The shown pilot symbol pattern has a regular distribution in the time and the frequency dimension of the OFDM system. The pilot symbols 20 , 21 , . . . , 28 are always transmitted in the same frequency subcarriers and in equidistant timepoints. For example, the pilot symbols 20 , 21 and 22 are transmitted in a first frequency subcarrier, whereby respectively four data symbols are transmitted between adjacent pilot symbols 20 , 21 and 21 , 22 . Pilot patterns 23 , 24 and 25 are transmitted in a second frequency subcarrier and the pilot symbol 26 , 27 and 28 are transmitted in a third frequency subcarrier. Thereby, the pilot symbols 20 , 23 and 26 are transmitted at the same first timepoint, the pilot symbols 21 , 24 and 27 are transmitted in the same second timepoint and the pilot symbols 22 , 25 and 28 are transmitted in the same third timepoint. Thus, always the same frequency subcarriers are used for the transmission of the pilot symbols and the transmission of the pilot symbols in the respective subcarriers always takes place at equidistant timepoints. Such a pilot symbol pattern is known from prior art OFDM systems. On the receiving side, the channel estimation for the data symbols between adjacent pilot symbols (in frequency and time) is performed by e.g. linear interpolation. For example, for the data symbols between the pilot symbols 20 and 21 in the same frequency subcarrier, a linear interpolation of the pilot symbols 20 and 21 is performed on the receiving side. For the data symbols between the adjacent pilot symbols 20 and 23 received at the same timepoint but in different frequency subcarriers, a linear interpolation is also performed. For data symbols in frequency subcarriers, in which no pilot symbols are transmitted, a combination of a time and a frequency interpolation of the respective adjacent pilot symbols is performed.
FIG. 3B shows also a regular distribution of the first pilot symbols to be transmitted by the first antenna 5 of the base station 1 . The difference to the pilot symbol pattern of FIG. 3A is here that the (in time) succeeding pilot symbols are not transmitted in the same frequency subcarrier as the preceding pilot symbol, but in the immediately adjacent subcarrier. For example, the pilot symbol 31 is not transmitted in the same frequency subcarrier as the preceding pilot symbol 30 , but the immediately adjacent (lower) frequency subcarrier. This pilot symbol pattern may allow a more accurate channel estimation for data symbols of frequency subcarriers, in which no pilot symbols are transmitted. Identical to the pilot symbol pattern proposed in FIG. 3A , the pilot symbols of the pilot symbol pattern proposed in FIG. 3B are also transmitted at identical timepoints. Thus, pilot symbols 30 , 34 and 38 are transmitted at the first identical timepoint, pilot symbols 31 , 35 and 39 are transmitted at the same second timepoint, pilot symbols 32 , 26 and 40 are transmitted at the same third timepoint and pilot symbols 33 , 37 and 41 are transmitted at the same fourth timepoint.
FIG. 4 comprises two FIGS. 4A and 4B , whereby FIG. 4A shows the pilot symbol pattern for the second pilot symbols to be transmitted by the second antenna 6 of the base station 1 , which corresponds to the pilot symbol pattern of the first pilot symbols shown in FIG. 3A . As can be seen, also the pilot symbol pattern of FIG. 4A shows a very regular distribution of pilot symbols 42 , 43 , . . . , 53 in frequency and time. The second pilot symbols are always transmitted in the same frequency subcarrier and at the same timepoint as the corresponding first pilot symbol. For example, the second pilot symbol 42 is transmitted in the same frequency subcarrier and at the same timepoint as the corresponding first pilot symbol 20 . The second pilot symbol 43 is transmitted in the same frequency subcarrier and at the same timepoint as the first pilot symbol 21 . The second pilot symbol 46 corresponds to the first pilot symbol 23 , the second pilot symbol 50 corresponds to the first pilot symbol 26 and so on. Thereby, the second pilot symbols of the pilot symbol pattern in FIG. 4A are alternatingly identical and orthogonal to the corresponding first pilot symbols of the pilot symbol pattern shown in FIG. 3A . The second pilot symbols 42 , 44 , 47 , 50 and 52 are identical to their corresponding first pilot symbols 20 , 22 , 24 , 26 and 28 . However, every other second pilot symbol (in time and frequency dimension) is the inverse complex value of the corresponding first pilot symbol. For example, a second pilot symbol 43 is the inverse complex value of the first pilot symbol 21 , the second pilot symbol 46 is the inverse complex value of the first pilot symbol 23 . The same is true for the second pilot symbol 48 and the first pilot symbol 25 and the second pilot symbol 51 and the first pilot symbol 27 . Thus, pairs of adjacent second pilot symbols, as e.g. the second pilot symbols 42 and 43 as well as the second pilot symbols 42 and 46 are orthogonal to the corresponding pairs of the first pilot symbols, e.g. first pilot symbol 20 and 21 or first pilot symbol 20 and 23 . Thus, orthogonality in the frequency as well as in the time dimension is ensured.
The same is essentially true for the pilot symbol pattern shown in FIG. 4B , which corresponds to the pilot symbol pattern shown in FIG. 3B . Similarly, the pilot symbols of the pilot symbol pattern shown in FIG. 4B are alternatingly identical and orthogonal (inverse complex) to the corresponding first pilot symbols shown in FIG. 3B .
The pilot symbol scheme proposed by the present invention can be applied to any linear channel estimation algorithm in wireless OFDM communications. For the sake of clarity, a simple two pilot symbol average based channel estimation algorithm for the pilot symbol patterns of FIG. 3A and FIG. 4A is used as an example in the following further detailed description.
Assuming that the complex values of all first pilot symbols 20 , 21 , . . . , 28 and the corresponding second pilot symbols having the identical value, i.e. second pilot symbols 42 , 44 , 47 , 50 , 52 , . . . , is A. The complex value of the second pilot symbols 43 , 46 , 48 , 51 , . . . , having a corresponding orthogonal value is then −A. For all the data symbols between the succeeding pilot symbols 20 and 21 or 42 and 43 , respective channel estimation values for the first (non-diversity) antenna 5 and the second (diversity) antenna 6 should be obtained reliably so that the STTD scheme can be applied.
As stated above, the antenna 11 and the receiving means 12 of the mobile terminal 10 receive the first and the second pilot symbols as superimposed or combined pilot symbols. Thus, let y 1 and y 2 be the received values from the first 20 , 21 and the second 42 , 43 pilot symbols. Since the time delay between the first and the second antenna 5 , 6 is negligible, the following equations are valid:
y 1 =A×h 1 1 +A×h 1 2 +n 1
and
y 2 =A×h 2 1 −A×h 2 2 +n 2 ,
whereby h 1 1 is the channel transfer function from the first antenna 5 to the receiving antenna 11 for the first pilot symbol 20 with value “A”, h 1 2 is the channel transfer function from the second antenna 6 to the receiving antenna 11 for the corresponding second pilot symbol 42 with value “A”, h 2 1 is the channel transfer function from the first antenna 5 to the receiving antenna 11 for the first pilot symbol 21 with value “A”, and h 2 2 is the channel transfer function from the second antenna 6 to the receiving antenna 11 for the corresponding second pilot symbol 43 with value “−A”. n 1 and n 2 are the noise values. If y 1 +y 2 is used as the channel estimation for the first (non-diversity) antenna 5 and y 1 −y 2 is used as the channel estimation for the second (diversity) antenna 6 , the signals from the first and the second antenna can be differentiated, the cross-interference can be eliminated and a reliable channel estimation for both antennas 5 and 6 can be obtained in the processing means 14 of the mobile terminal 10 , if the channel transfer function is assumed to be kept fixed within the interval between the preceding and the succeeding pilot symbols across the time dimension, i.e. h 2 1 =h 2 1 and h 1 2 =h 2 2 .
Thus, in the mobile terminal 10 the signals from the first and the second transmitting antenna 5 , 6 can be differentiated and consequently a separate channel estimation for each antenna 5 , 6 can be achieved. Since the pilot patterns of the first and the second pilot symbols are orthogonal, the cross-interference from the first and the second antenna 5 and 6 , can be eliminated. Thus, a STTD scheme can be used in a high data rate OFDM wireless communication system. It is to be noted, that the idea of the present invention can also be applied to OFDM based broadband radio access networks (BRAN), like HIPERLAN Type 2 systems. In this case, the pilot symbols are transmitted in preamble parts of a respective data burst comprising a preamble part and a data part. The pilot symbols comprised in the respective preambles should be alternatively identical and orthogonal for the two transmitting antennas. | A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension. | 7 |
FIELD OF THE INVENTION
This invention relates to the data processing field. More particularly, this invention is a look-ahead method and apparatus for predictive dialing using a neural network.
BACKGROUND OF THE INVENTION
Communications in the 1990s is considerably more complex that it used to be. Back in the stone age, when one Neanderthal wanted to communicate with another Neanderthal, he walked over to the second Neanderthal and grunted a few sounds. Gradually, communication evolved into written messages that could be delivered, first by messenger and later by mail.
Eventually, the telephone was invented. The telephone allowed a person to communicate with another person simply and efficiently by picking up the receiver and dialing the telephone number of the person he wished to speak to.
Salespeople were on a similar evolutionary track. When a salesman wanted to sell something to another person, he went door to door and tried to convince whoever was there that they should buy what the salesman was selling. When this proved to be inefficient due to the high number of doors slammed in the salesman's face, the salesman began mailing letters, brochures, and other written promotional materials to prospective customers. This was also inefficient, since a very high percentage of these mailings were considered to be "junk mail" by the recipients. Only a small percentage of the mailings resulted in sales.
It didn't take long for salespeople to discover the telephone. A salesman could quickly and inexpensively call a prospective customer and explain what he was selling. Since most calls ended quickly (with the potential customer expressing his lack of interest in a variety of ways and then hanging up) the bulk of the time was spent figuring out who was going to be called and trying to establish a connection with that person. The phone would often be busy or not answered, forcing the salesman to try again later and look for another prospective customer to call.
Salespeople began to realize that this approach was also inefficient. They discovered that computers could quickly perform much of the overhead involved with establishing connections with prospective customers. When a salesperson (now known as a "telemarketer") completed a call, he could instruct the computer to dial the next number from a list of numbers stored in the computer. This became known as outbound telemarketing.
Although very efficient, conventional outbound telemarketing still had problems. Much of the telemarketer's time was spent listening to busy signals or phones that weren't answered. In addition, telemarketers often grew weary of a high degree of rejection, and were reluctant to instruct the computer that they were ready to make another call. To solve these problems, predictive dialing was developed. In a typical predictive dialing arrangement, the potential customer is called by the computer. If someone answers the phone, the computer finds an available telemarketer and connects the call to this telemarketer.
While prior attempts in the predictive dialing field have been very good at the "dialing" part of predictive dialing, they have not been good at the "predicting" part. Often, the computer makes and completes a call to a customer, only to discover that there isn't an operator available to take the call. This is known as a "nuisance call". The customer then is subjected to a recorded announcement, a ringing signal, dead silence or a hang up. The opposite problem of having operators sitting idle waiting for the computer to dial a customer also frequently occurs in prior attempts. This is known as "operator idle time".
U.S. Pat. No. 4,829,563 to Crockett et al attempted to solve these problems of nuisance calls and operator idle time by dynamically adjusting the number of calls dialed based on short term comparisons of the weighted predicted number of calls versus the predicted number of operators, and based on periodic adjustment of a weighting factor. Crockett's "short term" comparisons are always "reactive" in nature--changes are made only after nuisance calls or operator idle time rise to unacceptable levels. Therefore, Crockett's "reactive dialing" approach falls short of solving the above-identified problems of nuisance calls and operator idle time.
SUMMARY OF THE INVENTION
It is a principle object of the invention to provide an efficient predictive dialing technique.
It is another object of the invention to provide a predictive dialing technique that maintains nuisance calls and operator idle time within acceptable levels.
It is another object of the invention to provide a predictive dialing technique able to look ahead and anticipate changes in calling patterns and adjust accordingly, before nuisance calls or operator idle time rise to unacceptable levels.
It is another object of the invention to use a neural network in a predictive dialing technique that is able to look ahead and anticipate changes in calling patterns and adjust accordingly, before nuisance calls or operator idle time reach unacceptable levels, based on what the neural network has learned.
These and other objects are accomplished by the look-ahead method and apparatus for predictive dialing using a neural network disclosed herein.
A predictive dialing system having a computer connected to a telephone switch stores a group of call records in its internal storage. Each call record contains a group of input parameters, including the date, the time, and one or more workload factor parameters. Workload factor parameters can indicate the number of pending calls, the number of available operators, the average idle time, the connection delay, the completion rate, the conversation length and the nuisance call rate, among other things. In the preferred embodiment, each call record also contains a dial action, which indicates whether a call was initiated or not.
These call records are analyzed by a neural network to determine a relationship between the input parameters and the dial action stored in each call record. This analysis is done as part of the training process for the neural network. After this relationship is determined, the computer system sends a current group of input parameters to the neural network, and, based on the analysis of the previous call records, the neural network determines whether a call should be initiated or not. The neural network bases its decision on the complex relationship it has learned from its training data --perhaps several thousand call records spanning several days, months, or even years. The neural network is able to automatically adjust--in a look ahead, proactive manner--for slow and fast periods of the day, week, month, and year.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a block diagram of the predictive dialing system of the invention.
FIG. 2 shows how a massively parallel hardware implemented neural network can be simulated on a serial Von Neumann based computer system.
FIGS. 3A-3B shows a conceptual framework of the computing environment of the invention.
FIG. 4 shows the neural network data structure of the invention.
FIGS. 5-9 show the flowcharts of the neural network utility of the invention.
FIGS. 10A-10B show examples of numeric training data used in the preferred and alternate embodiments of the invention.
FIGS. 11-17 show screens displayed to a user creating, training, and running the predictive dialing neural network of the invention.
RELATED PATENT APPLICATION
This patent application is related to commonly assigned U.S. patent application Ser. No. 07/482,450, filed Feb. 2, 1990, incorporated herein by reference.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a block diagram of predictive dialing system 5 of the invention. Computer system 10 consists of main or central processing unit 11 connected to storage 12. Storage 12 can be primary memory such as RAM and/or secondary memory such as magnetic or optical storage. Processor 11 is connected to co-processor 13. Co-processor 13 may provide generic math calculation functions (a math co-processor) or specialized neural network hardware support functions (a neural network processor). Co-processor 13 is not necessary if CPU 11 has sufficient processing power to handle an intensive computational workload without unacceptable performance degradation. CPU 11 is also connected to user interface 14. User interface 14 allows developers and users to communicate with computer system 10, normally through a workstation or terminal.
In the preferred embodiment, computer system 10 is an IBM Application System/400 midrange computer, although any computer system could be used. Co-processor 13 is preferably a processor on the Application System/400 midrange computer, but could also be the math co-processor (such as an Intel 80387 math co-processor) found on personal computers, such as the IBM PS/2. In this case, CPU 11 and co-processor 13 would communicate with each other via IBM PC Support.
Computer system 10 is connected to telephone switch 17 over line 15 through telephony enabler 20. In the preferred embodiment, telephony enabler 20 is the IBM licensed program product CallPath/400, although other commercially available telephony enablers could be used. In the preferred embodiment, telephone switch 17 is a Teleos IRX9000, although any other switch capable of interfacing with a computer and supporting a predictive dialing application may be used. Switch 17 is able to establish connections between an external telephone, such as external telephone 19, with an operator telephone, such as operator telephone 18, in a conventional manner under the direction of computer system 10. Computer system 10 also communicates with a plurality of operator terminals, such as operator terminal 16, via user interface 14. Data associated with the calls made by predictive dialing system 5 (such as a script or information about the called party) may be displayed on operator terminal 16.
FIG. 2 shows how neural network (parallel) computers can be simulated on a Von Neumann (serial) processor system. There are many different neural network models with different connection topologies and processing unit attributes. However, they can be generally classified as computing systems which are made of many (tens, hundreds, or thousands) simple processing units 21 which are connected by adaptive (changeable) weights 22. In addition to processors and weights, a neural network model must have a learning mechanism 23, which operates by updating the weights after each training iteration.
A neural network model can be simulated on a digital computer by programs and data. Programs 26 simulate the processing functions performed by neural network processing units 21, and adaptive connection weights 22 are contained in data 27. Programs 28 are used to implement the learning or connection weight adaptation mechanism 23.
FIG. 3A shows the conceptual layout of the neural network of this invention and how it relates to the predictive dialing application software. At the highest level is application programming interface 31 (API). API 31 is a formally specified interface which allows application developers lacking expert knowledge of neural networks to access and use the utility programs and data structure of neural network shell 32 in their application programs.
Neural network shell 32 consists of a set of utility programs 33 and a neural network data structure 50. Shell 32 provides the capability for easily and efficiently defining, creating, training, and running neural networks in applications on conventional computing systems.
Any neural network model, such as example models 35-38, can be supported by neural network shell 32 by defining a generic neural network data structure 50 which can be accessed by all of the utility programs in neural network shell 32. Each neural network model is mapped onto this generic neural network data structure, described in more detail in FIG. 4. Programs specific to each neural network model are called by neural network utility programs 33, as will be discussed later.
FIG. 3B shows how predictive dialing application program 41 becomes neural network application program 40 by interfacing with one or more of the neural network utility programs 45-48 in neural network shell 32. Utility programs 45-48 in turn interface with data structure 50. Data to be processed by neural network application program 40 (also referred to herein as "neural network") enters on input 42. After the data is run through the neural network, the result is returned to application program 41 on line 44. Application program 41 and utility programs 46-48 reside in suitably programmed CPU 11 and/or co-processor 13 (FIG. 1). Data structure 50 resides in storage 12 and/or in internal storage of CPU 11 and/or co-processor 13.
FIG. 4 shows neural network data structure 50 of the invention. Data structure 50 provides a common framework which allows any neural network model to be defined for use in an application program. This common framework is accomplished by providing several of the fields in neural network data structure 50 for model specific parameters. Pages 103-105 of the attached Appendix I, entitled "AS/400 Neural Network Utility: User's Guide and Reference PRPQ P84189" (order number SC21-8202-0) shows how the model specific fields of data structure 50 are used by the Back Propagation, ART, Self Organizing Feature Map, TSP, and BAM neural network models.
Data structure 50 consists of header portion 60 and body portion 90. Header portion 60 contains fields 61-79. Fields 61 and 62 are pointers to other neural network data structures, if any. If neural networks are arranged in a linked list for serial processing of data, the first pointer would link to the previous network. This link can be used to obtain the outputs from the previous sub-net in the larger network. The second pointer would be a pointer to the next network. Depending on the collection of sub-networks, either or both of these links would be used in a complex (hybrid) network composed of several sub-networks.
Neural network data structures can be chained together to provide increased flexibility and function to the application program. Providing the capability of linking to two additional neural networks allows "super" networks made up of modules of networks.
Field 63 is an offset in bytes to the next free space in body portion 90. Field 64 is an offset in bytes to end of the neural network data structure. Since body portion 90 is a variable length data area, fields 63 and 64 are needed to keep track of the size of the data structure and the next available free space in body portion 90.
Field 65 contains the name of the neural network. The name of the predictive dialing neural network, discussed in more detail later, will be entered into this field. The name of this network is NNPACER, and this name is placed in field 65 by the create neural network utility program, as will be discussed later.
Field 66 contains the name of the library where the neural network is located and is required in the preferred embodiment. In the AS/400, programs are stored in libraries. Libraries are similar to sub directories in the personal computing environment. Field 66 would not be necessary in computing environments without libraries. Field 67 contains the network version identifier. This information is used to prevent mismatches between neural network shell programs and neural network data structures. As new versions or releases of software are developed, compatibility with existing networks is desirable. If any enhancements require changes to the fundamental network data structure, this field would allow detection of a software-to-data mismatch. The software could call a conversion routine to update the data structure format, or accept down-level data structures.
Field 79 contains the name of the neural network model or type. The neural network model name used in the preferred embodiment by the predictive dialing neural network is "*BKP" for Back Propagation.
Field 68 contains the current state of the network. Possible states are `INITIALIZE` if the network is being created, `TRAINING` if the network is being trained, or `LOCKED` if the training is complete and ready to run.
Field 69 is an optional field for storing a model specific alphanumeric field, if desired. Field 70 keeps track of the elapsed network training time in seconds.
Fields 71-74 contain different types of parameters used differently by specific neural network models. Field 71 contains up to four network Boolean parameters. A Back Propagation neural network model, for example, uses two of these parameters for determining whether epoch update and random input is enabled or disabled. The network Boolean parameters are also known as network flags. Of course, field 71 (as well as other fields of data structure 50) could be made larger or smaller to accommodate fewer or greater than the number of parameters used in the preferred embodiment, if desired. Field 72 contains network size parameters. This field contains up to five model-specific network size integer parameters. Field 73 contains up to five model-specific network index integer parameters. Field 74 contains up to six model-specific network training real parameters, such as learn rate, momentum, epoch error, etc.
Field 75 keeps track of the number of training epochs (an epoch is an iteration through the complete set of training data) of the neural network. Field 76 contains an array of offsets in bytes to the start of each model-specific array in body portion 90. Field 77 contains an array of resolved pointers to the start of each model-specific array in body portion 90. Field 78 contains an array of parameters describing the type of data held in each array. For example, some neural models accept only binary inputs. In the preferred embodiment, if a parameter in field 78 contains a "1" then its corresponding array contains bitmapped data. If the parameter is a "2" then its corresponding array contains single precision floating point data (the default). If it is "3" then its corresponding array contains fixed point zoned decimal data. These parameters are used to make more efficient use of storage.
The contents of body portion 90 of data structure 50 will now be discussed. Body portion 90 is a variable-length data area which contains a number (sixteen in the preferred embodiment) of model-specific arrays. Pages 103-105 of Attachment I shows the arrays mapped to header portion 60 and body portion 90 for each of the exemplary neural network models. For example, the back propagation model maps eleven arrays to body portion 90: activations, weights, threshold, weight deltas, etc, as shown under the heading "Array Mapping" on page 103.
Data structure 50 is created by the Create Neural Network utility program, as will be discussed later (FIGS. 7A-7B). The Teach and Run utility programs access the header information to initialize the pointers to the data area arrays. The data in the data area arrays in turn are used in the simulation of the neural network training and calculation processes.
FIGS. 5-9 show the flowcharts of the invention, as performed by suitably programmed CPU 11 and/or co-processor 13. FIG. 5 shows an overview of the major steps in the neural network application program development process. Block 110 asks if there is a new neural network model to be defined. If so, block 200 calls the Define Neural Network Model Subroutine (FIG. 6). If not, block 120 asks if the user wishes to create a neural network data structure. A neural network data structure is created for each neural network. For example, one neural network data structure would be created for our predictive dialing neural network. If block 120 is answered affirmatively, block 300 calls the Create Neural Network Data Structure Subroutine (FIG. 7). If not, block 130 asks if the user wishes to train a neural network. A neural network needs to be trained with training data so that it can learn the relationship between input data and the desired output result, or extract relevant features from input data. If so, block 400 calls the Teach Neural Network Subroutine (FIG. 8). If not, block 140 asks if the user wants to run a neural network. If so, block 500 calls the Run Neural Network Model Subroutine (FIG. 9). If not, the program ends in block 190.
FIGS. 6A-6D describe Define Neural Network Model Subroutine 200. For our predictive dialing neural network we want to define a Back Propagation neural network model. Block 201 assigns a neural network model specific meaning to network string field 69, if desired. In our network, this field is not needed, so a null string is assigned. Block 202 assigns a neural network model specific meaning to Boolean parameters field 71. In our network, two Boolean parameters are assigned: Epoch update (Y/N) and Random Inputs (Y/N). Block 203 assigns a neural network model specific meaning to network size parameters field 72. In our network, five parameters are assigned: number of inputs, number of units in hidden layer 1, number of units in hidden layer 2, number of outputs, and number of processing units. Block 204 assigns a neural network model specific meaning to network index parameters field 13. In our network, the following parameters are assigned: first hidden unit 1, last hidden unit 1, first hidden unit 2, last hidden unit 2, and first output. Block 205 assigns a neural network model specific meaning to network training parameters field 74. In our network, the following parameters are assigned: learn rate, momentum, pattern error, epoch error, and tolerance. Block 206 assigns a neural network model specific meaning to network array offsets field 76. Since there are eleven data arrays to be defined in a Back Propagation neural network model, this field contains the byte offset to the first element of each of the eleven arrays located in body portion 90.
Block 210 calls the Build Neural Network Model Create Program Subroutine of FIG. 6B. Referring now to FIG. 6B, subroutine 210 requires that model specific routines are built so that they can be executed later by the Create Neural Network Data Structure Subroutine (FIG. 7). Block 211 provides a simple routine to prompt the user for parameter information specific to the neural network and check for erroneous and inconsistent parameter values. For example, block 211 would provide a routine that would prepare a screen similar to FIG. 12. The screen in FIG. 12, among other things, prompts the user for information about the following parameters: Number of input units, number of hidden units L1, number of hidden units L2, and number of output units.
Block 212 provides a routine to initialize the generic neural network data structure with default parameter values to create the default neural network data structure for this neural network model. All neural network models have the same generic neural network data structure. Each individual neural network model has its own unique default data structure. Therefore, all neural networks application programs that use the same neural network model (such as Back Propagation) will input unique parameter values into the same default neural network data structure.
Block 213 saves the neural network model create program built in subroutine 210 by giving it a unique name and writing it to storage 12 (FIG. 1). In the preferred embodiment, this program can be written in any language desired which has the capability to access the data structure. Block 219 returns to block 230 of FIG. 6A.
Block 230 calls the Build Neural Network Model Teach Program Subroutine of FIG. 6C. Referring now to FIG. 6C, subroutine 230 requires that model specific routines are written so that they can be executed later by the Teach Neural Network Subroutine (FIG. 8). Block 231 provides a simple routine to initialize the network array pointers in field 77 of FIG. 4. Block 232 provides a routine for copying network size, index and training parameters (fields 72-74) into local variables. This is done to improve performance and programming reliability. Block 233 provides a routine to initialize the neural network. Block 233 initializes counters and variables used by the neural network teach program. If network status field 68 is "Initialize", block 233 also initializes data array values (connection weights) and changes the status from "Initialize" to "Training" in field 68.
Block 234 provides a routine to perform a single teach step for this neural network model. This routine provides a mechanism, highly dependent on the neural network model, used to adjust the values of the data in the data array of body 90 so that the network can learn the desired functions. Those skilled in the art would take a neural network model description of its weight adjustment procedures (like those found in scholarly articles referenced in Appendix I on pages viii and ix) and simply convert this description to a program, using a computer language of their choice, that accesses the data structure of the invention.
Block 235 provides a routine to be performed when the training epoch processing has been completed. This routine can vary in complexity from a simple clean up procedure such as resetting variables to a more complex adjustment of data array values, depending on the neural network model. Those skilled in the art would take a neural network model description of its unique end of epoch processing and simply convert this description to a program, using a computer language of their choice, that accesses the data structure of the invention.
Block 236 saves the neural network model teach program built in subroutine 230 by giving it a unique name and writing it to storage 12 (FIG. 1). Block 239 returns to block 250 of FIG. 6A.
Block 250 calls the Build Neural Network Model Run Program Subroutine of FIG. 6D. Referring now to FIG. 6D, subroutine 250 requires that model specific routines are written so that they can be executed later by the Run Neural Network Subroutine (FIG. 8). Block 251 provides a simple routine to initialize the network array pointers in field 77 of FIG. 4. Block 252 provides a routine for copying network size, index and training parameters (fields 72-74) into local variables. Block 253 provides a routine to pass input data through the neural network. Block 254 provides a routine to return the output result to the Run Neural Network Subroutine. Block 255 saves the neural network model run program built in subroutine 250 by giving it a unique name and writing it to storage 12 (FIG. 1). Block 259 returns to block 260 of FIG. 6A.
Block 260 enters the name of the neural network model (such as "*BKP" for back propagation) and the names of the create, teach, and run programs for this model saved in blocks 213, 236, and 255 into a model definition file stored in storage 12. Block 270 returns to block 120 of FIG. 5.
In the preferred embodiment, five neural network models are predefined for the convenience of the application developer or user. The predefined models are Back Propagation, Adaptive Resonance Theory, Self Organizing Feature Maps, Self Organizing TSP Networks, and Bidirectional Associative Memories. Therefore, these models do not have to be defined by the user using the Define Neural Network Model Subroutine. The predictive dialing application program of the invention uses the predefined Back Propagation model as its neural network model, although other models could also be used.
The remaining flowcharts will be discussed in conjunction with the predictive dialing neural network of the invention. The user creates this neural network by answering block 120 affirmatively in FIG. 5 and calling the Create Neural Network Data Structure Subroutine in block 300 (FIG. 7). Referring now to FIG. 7A, block 301 prompts the user for the name of the neural network and textual description information, as shown in FIG. 11. The user enters "NNPACER" as the name of the neural network and "Neural Network Pacer for Predictive Dialing" for the textual description. Block 302 prompts the user for the name of the neural network model. As shown in FIG. 11, the user enters "*BKP", an abbreviation for the Back Propagation neural network model. Block 303 checks to see if the model "*BKP" was defined in the model definition file in block 260 of FIG. 6A. If not, block 304 posts an error message and the user is asked to reenter the name of the neural network model in block 301. In our network, the model definition file contains the "*BKP" and block 330 calls the Run Model Create Program Subroutine for this model of FIG. 7B. The Model Create Program was prepared by the Build Model Create Program Subroutine of FIG. 6B, as has been discussed. The name of this program, along with the names of the Teach and Run programs for this model, are all contained in the model definition file.
Referring now to FIG. 7B, block 331 creates the default neural network data structure for this neural network model, by running the routine provided in block 212 of FIG. 6B. Block 332 prompts the user for neural network specific parameters, as shown in FIG. 12. In the preferred embodiment, the user specifies 16 input units (one each for month, day, year, day of week, hour, minute, second, pending calls, available operators, average connect delay, average idle time, nuisance call rate, average completion rate, average conversation length, idle time delta and nuisance call delta), 35 hidden units and 1 output unit (call action). In the preferred embodiment, the number of hidden units is equal to 2 * (number of inputs+number of outputs) +1. Block 333 checks to see if the user supplied parameters are acceptable. Note that the routine provided by block 211 in FIG. 6B to prompt the user for these parameters placed limits on the user's input, such as 1-1000 output units. If the user inputs a value outside of any of these ranges, block 333 would be answered negatively, an error message would be posted in block 334, and the user would be asked to reenter the data in block 332. In addition, if the user inputs inconsistent parameter information, an error message would also be posted. In our case, the user supplied parameters are all acceptable, so block 335 fills in all user supplied parameters into the default data structure created by block 331. Block 336 performs calculations to fill in network index parameters field 73 and network array offsets field 76, based on the data now residing in the data structure. Block 337 initializes the Boolean parameters in field 71 (both to "N" in our example) and the training parameters in field 74 (to the values shown in FIG. 15 in our example) Block 338 allocates and initializes the data array fields located in body portion 90. In a back propagation neural network model, the following arrays would be allocated: activations, weights, threshold, weight deltas, threshold deltas, teach, error, delta, network input, weight derivative, and threshold derivative. These values are all initialized (as determined by the neural network model) in block 338. After block 338 is executed, the neural network data structure contains all the information needed to teach the neural network how to perform predictive dialing. The subroutine returns in block 339 to block 305 in FIG. 7A. Block 305 returns to block 130 in FIG. 5.
Note that once a neural network data structure has been created, it can be transported to another computer system to be taught and/or run. The other computer system can be of an entirely different architecture and run an entirely different operating system than the computer system that created the neural network data structure. This flexibility is possible since the data structure contains data that can be used universally among different computer systems.
Since our user wants to train his newly created neural network to perform predictive dialing, he answers block 130 affirmatively in FIG. 5, thereby calling the Teach Neural Network Subroutine in block 400 (FIG. 8). Referring now to FIG. 8A, block 401 prompts the user for the name of the neural network and library as shown in FIG. 14. The user enters "NNPACER" as the name of the neural network, "BIGUS" as the library name. FIG. 14 also gives the user the opportunity to enter in the name of a custom interface program he can write to improve the usability of his particular neural network, if desired. In addition, the user is asked if he wants the training results to be logged or displayed, and (if a custom interface program exists) whether he wants the training data taken automatically from the data set or one step at a time from the user when he presses the enter key. Block 402 sees if the data structure specified in block 401 exists. If not, an error is posted and the user is returned to block 401. If so, block 403 prompts the user for the name of the data set where the training data is located, As shown in FIG. 13, the user enters "NNDATA" as the data set and "NNPACER" as the data set member where the training data is located.
FIG. 10A shows the initial training data used in the preferred embodiment. Initial training data can be generated manually taking into account known and estimated conditions in a predictive dialing environment. For example, the first two records of training data indicates that calls after 4:00 PM on Fridays have a lower completion rate than calls at 10:30 AM on Wednesdays. Therefore, with all other workload factors being even, the neural network may learn that it should make a call at 4:00 PM on Friday, but shouldn't make the call at 10:30 AM on Wednesday, since the desired nuisance rate might be exceeded. The third record indicates that a call shouldn't be made because the average idle time is too low. The fourth record indicates that a call shouldn't be made because the average nuisance call rate is too high. The fifth record indicates that a call shouldn't be made because the number of calls pending is too high. The sixth record indicates that a call should be made because the number of available operators is sufficiently high.
Input parameters 811-814 make up date parameter 810. Input parameters 821-823 make up time parameter 820. In the preferred embodiment, time parameter 820 takes into account the time zone of the called party. Input parameters 831-838 make up workload factor parameter 830. In an alternate embodiment shown in FIG. 10B, date parameter 810 consists of a single input parameter. Time parameter 820 consists of a single input parameter. Workload factor parameter 830 consists of a single input parameter. Workload factor parameter 830 could be selected to be whatever the application developer considers to be the most important parameter, such as idle time delta or nuisance call delta. Output parameter 850 is not needed if only records where a call was made are stored.
Block 404 determines that the data set exists, so block 405 prompts the user for the name of the custom interface program, if any. If symbolic data is stored in the data set, a user specified custom interface program is needed to convert symbolic data (that humans understand) into numeric data (that neural networks understand). A custom interface program may also be used to normalize input data to give all data a range between 0 and 1, if desired. In our network, a custom interface program was specified in FIG. 13, and this program normalizes all data in a conventional matter for computational efficiency. Block 420 calls the Run Model Teach Program Subroutine for this model of FIG. 8B. The Model Teach Program was prepared by the Build Model Teach Program Subroutine of FIG. 6C, as has been discussed.
Referring now to FIG. 8B, block 433 performs the initialization routine built by blocks 231, 232 and 233 of FIG. 6C. Block 421 checks to see if a custom interface program was specified. If so, block 422 gets the data from the custom interface program. Otherwise, block 423 gets the data directly from the data set. Block 424 performs one teach step by running the neural network model-dependent routine provided by block 234 of FIG. 6C. In our example, the values of the data in the data arrays in body 90 are adjusted to minimize the error between the desired and actual network outputs. Block 425 again checks for a custom interface program. If it exists, block 426 checks to see if the user wants the values of the data in the data structure to be displayed. If so, a custom screen generated by the custom interface program is displayed in block 427. An example custom screen is shown in FIG. 17. If no custom interface program exists but the user wants data displayed, a default screen is displayed in block 428. An example default screen is shown in FIG. 15.
Referring again to FIG. 8B, block 429 checks to see if the user wanted the data logged. If so, block 430 performs custom or default logging of data. In either event, block 434 checks to see if one epoch has been completed. An epoch is complete when all training data in the data set has been processed once. If not, control loops back to block 421 to get the next training data. If one epoch has been completed, block 435 performs the end of epoch processing routine built by block 235 in FIG. 6C. In our example, the end of epoch processing routine determines if the difference between the actual and desired output for our output unit (call action) for all training data is less than the specified tolerance (one of the training parameters in field 74). If so, it sets the network status in field 68 to "locked". When the status of the neural network is "locked" the values of the data arrays are not permitted to change.
Block 431 then checks to see if the number of iterations specified by the user has been completed. Until this happens, block 431 is answered negatively and flow returns back to block 421 to perform another iteration through the training data. When the training period is complete, block 431 is answered positively. The subroutine returns in block 439 to block 407 of FIG. 8A. Block 407 returns to block 140 of FIG. 5.
Since our user wants to run his newly trained neural network to perform predictive dialing, he answers block 140 affirmatively in FIG. 5, thereby calling the Run Neural Network Subroutine in block 500 (FIG. 9). Alternatively, predictive dialing application program 41 (FIG. 3B) can call the Run Neural Network Subroutine directly, thereby bypassing FIG. 5.
Referring now to FIG. 9A, block 501 performs the initialization routine built by blocks 251 and 252 of FIG. 6D. Block 502 determines the name of the neural network. Block 530 calls the Run Model Run Program Subroutine for this model of FIG. 9B. The Model Run Program was prepared by Build Model Run Program Subroutine of FIG. 6D, as has been discussed.
Referring now to FIG. 9B, block 531 gets the date, time, day of week, number of pending calls, and number of available operators from the system. It then calculates the average connect delay, the average completion rate, the average idle time, the average nuisance call rate, the average completion rate and the average conversation length. Although these averages can be calculated any number of ways, a preferred way is to keep a running count of the last 5 minutes of activity and determine the various averages over this time period. Block 533 calculates an idle time delta and a nuisance call delta. Idle time delta is the seconds per hour difference between a desired idle time (a variable entered into the computer system by the user) and the actual idle time. For example, if 205 seconds per hour is the desired idle time, and if the actual idle time is 240 seconds, the idle time delta would be -35 seconds (205-240=-35). The nuisance call delta is desired percentage of nuisance calls minus actual percentage of nuisance calls. For example, if desired nuisance calls percentage is 0.64% and actual nuisance calls percentage is 0.2%, the nuisance call delta is +0.4% (0.6%-0.2%=0.4%). The first record of FIG. 10A shows an idle time delta of -35 seconds and a nuisance call delta of 0.4%. The input data of blocks 531 and 533 are considered to be a "current call record".
The desired idle time and desired percentage of nuisance calls are design choices and can vary based on the particular application. A 300 second to 600 second idle time per hour (5-10 minutes) may be desirable to minimize operator fatigue yet also avoid operator boredom and low productivity. It is normally desirable to keep the nuisance call percentage as close to 0% as possible to minimize customer annoyance with being contacted by a computer when no operator is available.
The data used in blocks 531 and 533 is normally determined from information retrieved from telephony enabler 20. In the preferred embodiment, this information is retrieved from the CallPath/400 telephony enabler by using a series of commands supported by the CallPath/400 Application Programming Interface. This interface is described in more detail in IBM document GC21-9867, CallPath/400 Programmer's Reference, attached hereto as Appendix II. Some of the specific commands that can be used by those skilled in the art are Make -- Call, Receive, Add -- Party, and Disconnect. These commands return the information needed to determine the data used in blocks 531 and 533 in the form of the following events: Call -- Alerting, Call -- Connected, Call -- Rejected, Disconnected, (and associated timestamp information included with the above events). The Feature -- Invoked event is also used in determining status of operators or agents.
Block 535 runs all the input data contained in the current call record through the trained neural network. When the neural network was trained, it determined a relationship between input data contained in call records with a call action (make or don't make the call). Based on this relationship, the neural network looks at the input data in the current call record and, in the preferred embodiment, passes a numeric value between 0 and 1 to predictive dialing application program 41 via line 44 (FIG. 3B). The closer this numeric value is to 1, the more confident the neural network is that a call should be made. Predictive dialing application program 41, in the preferred embodiment, gets a threshold value of 0.5, although this could be larger or smaller. Therefore, a numeric value of 0.5 or greater from the neural network indicates that a call should be made, while a numeric value less than 0.5 indicates that a call should not be made.
Block 540 asks if the neural network indicated that a call should be made. If so, block 541 instructs the switch to make the call. In the preferred embodiment, this is done by informing telephony enabler 20, that a call should be made. Telephony enabler 20 handles the communications protocol with the switch necessary to make calls.
Block 542 saves the current call record in a temporary dataset for future analysis, as will be discussed later. In the preferred embodiment, block 542 appends the call action onto the call record and saves all call records, whether the call was made or not. An alternate embodiment is contemplated where the call action is not appended and only call records where a call was made is saved in block 542.
Block 545 checks to see if the application program wants to stop making calls. The application program may automatically stop making calls after a certain elapsed time, at a specific time of day, or if all the operators have gone home. If no such indication to stop making calls is received, flow of control loops back to block 531 where new input data is retrieved. If an indication to stop making calls is received, block 550 asks if the call records saved through various iterations of block 542 should be analyzed to see if the neural network needs further training. If analysis is not desirable, the subroutine returns in block 590 to block 519 to block 190 in FIG. 5, where the program ends, or, alternatively, returns to predictive dialing application program 41 that called it for further processing.
If block 550 is answered affirmatively, Analyze Call Records Subroutine 600 of FIG. 9C is called. Referring now to FIG. 9C, block 601 asks if there is a call record to process. If so, block 605 asks if the average idle time is greater than desired. If so, block 606 asks if a call was made. A call should have been made if the idle time is greater than desired, since operators are sitting around waiting for something to do. If block 606 indicates that a call was not made, the neural network made the "wrong" decision in this case. Block 607 changes the Dial Action field in the call record from a "0" (indicating that a call wasn't made) to a "1" (indicating that a call was made). This change is done to make the call record reflect the desired result so that the neural network can learn from it later. If block 606 indicates that a call was made, the neural network made the right decision. In either event, flow returns back to block 601 to look for another record to process.
If block 605 was answered negatively, block 615 asks if the average idle time is less than desired. If so, block 616 asks if a call was made. A call should not have been made if the idle time is less than desired, since operators are overworked. If block 616 indicates that a call was made, the neural network made the "wrong" decision in this case. Block 617 changes the Dial Action field in the call record from a "1" (indicating that a call was made) to a "0" (indicating that a call wasn't made). As before, this change is done to make the call record reflect the desired result so that the neural network can learn from it later. If block 616 indicates that a call was not made, the neural network made the right decision. In either event, flow returns back to block 601 to look for another record to process.
If block 615 was answered negatively, block 625 asks if the average nuisance call rate is greater than desired. If so, block 626 asks if a call was made. A call should not have been made if the nuisance call rate is greater than desired, since it will be likely that there will be no operators available to take the call. If block 626 indicates that a call was made, the neural network made the "wrong" decision in this case. Block 627 changes the Dial Action field in the call record from a "1" (indicating that a call was made) to a "0" (indicating that a call wasn't made). As before, this change is done to make the call record reflect the desired result so that the neural network can learn from it later. If block 626 indicates that a call was not made, the neural network made the right decision. In either event, flow returns back to block 601 to look for another record to process.
When block 601 indicates that there are no more call records to process, the subroutine returns in block 650 to block 560 in FIG. 9B. Block 560 adds the call records (some of which may have been changed by subroutine 600) to the training dataset. The temporary dataset is then erased. By putting these records into the training dataset, the neural network can be retrained by restarting the flowchart of FIG. 5 and indicating that the network is to be trained. In this manner, the neural network can improve its learning process and make fewer and fewer mistakes in the future. After a few of these learning iterations, the neural network should be able to consistently stay within the desired idle rate and nuisance call percentage parameters and be able to look ahead and anticipate changes in calling patterns and adjust accordingly, before the nuisance call rate or operator idle time reach unacceptable levels.
While this invention has been described with respect to the preferred embodiment, it will be understood by those skilled in the art that various changes in detail may be made therein without departing from the spirit, scope and teaching of the invention. For example, the input parameters selected could be quite different from those in the preferred embodiment. Economic factors such as unemployment rate or gross national product may be added; other factors such as current weather conditions may also be added. In addition, the desired idle time or the desired nuisance call percentage can be larger or smaller than the exemplary values shown herein. Although a neural network is used in the preferred embodiment, the relationship between a selected group of input parameters and the desired output can be determined through a expert system or other programming or logical circuitry. Accordingly, the herein disclosed is to be limited only as specified in the following claims. | A predictive dialing system having a computer connected to a telephone switch stores a group of call records in its internal storage. Each call record contains a group of input parameters, including the date, the time, and one or more workload factors. Workload factors can indicate the number of pending calls, the number of available operators, the average idle time, the connection delay, the completion rate, and the nuisance call rate, among other things. In the preferred embodiment, each call record also contains a dial action, which indicates whether a call was initiated or not. These call records are analyzed by a neutral network to determine a relationship between the input parameters and the dial action stored in each call record. This analysis is done as part of the training process for the neutral network. After this relationship is determined, the computer system sends a current group of input parameters to the neural network, and, based on the analysis of the previous call records, the neural network determines whether a call should be intiated or not. The neural network bases its decision on the complex relationship it has learned from its training data--perhaps several thousand call records spanning several days, months, or even years. The neural network is able to automatically adjust--in a look ahead, proactive manner--for slow and fast periods of the day, week, month, and year. | 8 |
TECHNICAL FIELD
[0001] A locking device is used in particular in order to be fitted to a nacelle, itself designed to be fitted to an aircraft.
BACKGROUND
[0002] A nacelle is a streamlining element making it possible to protect a jet engine of an aircraft. A nacelle usually comprises two elements articulated on the pylon of the aircraft so as to allow access to the engine housed inside the nacelle, particularly during maintenance operations.
[0003] Conventionally, a nacelle comprises at least a first and a second locking device, comprising respectively a first and a second locking system, fitted with a first and a second control handle, designed to be actuated by an operator.
[0004] The first locking system is designed to lock the nacelle in the junction zone placed in the bottom portion, that is to say at 6 o'clock, while the second locking system is designed to achieve the locking in the junction zone placed in the top portion, that is to say at 12 o'clock.
[0005] The handles are both placed in the bottom portion of the nacelle, for reasons of accessibility.
[0006] The use of such locking devices has the drawbacks explained below.
[0007] When the nacelle is opened, the two elements are articulated about shafts situated in the top portion, the elements being subjected to the action of cylinders.
[0008] The first locking system situated in the bottom portion is capable of preventing an accidental opening of the nacelle when the latter is locked. Specifically, the first locking system is situated at a distance from the articulation shafts of the two elements of the nacelle and the force exerted by the cylinders is not sufficient to cause damage to the first locking system or to the nacelle.
[0009] Conversely, if only the second locking system situated in the top portion of the nacelle is locked, the latter is not capable of withstanding the force exerted by the cylinders, unless a particular and constraining design of the structure of the nacelle is provided. In this case, the second locking system, or even the articulated elements of the nacelle, can be greatly damaged.
[0010] In addition, the operator is forced to actuate two handles in order to unlock or lock the aforementioned locking devices, which is awkward and easily gives rise to operating errors, the consequences of which are in particular explained above.
[0011] The risk of such an operating error is all the greater if the operator does not see the second locking system placed in the top portion of the nacelle. The closure of the latter is therefore carried out “blind”.
[0012] Finally, other drawbacks are the complexity, the weight and the space requirement of the two locking devices.
BRIEF SUMMARY
[0013] The invention relates to a locking device comprising a first locking system fitted with a control handle, designed to be actuated by an operator, characterized in that it comprises a second locking system, connected to the first by linking means arranged to actuate the second locking system via the actuation of the first, the first locking system being actuated alternately between a locked state and an unlocked state by the displacement of the handle over the whole of a determined travel, the linking means comprising sequencing means arranged to actuate the second locking system, respectively between a locked state and an unlocked state of the latter, when the handle is moved over only a portion of the travel of the latter.
[0014] In this manner, when the locking device is opened with the aid of the handle, the second locking system is unlocked or “opened” before the first. Therefore, when the first locking system is completely unlocked, the operator is certain that the second locking system is as well.
[0015] Similarly, when the locking device is closed, the second locking system is locked or “closed” before the first. Therefore, when the first locking system is completely locked, the operator is certain that the second locking system is as well.
[0016] Therefore, in an example of application to a nacelle, the first locking system is advantageously that placed at 6 o'clock, the second being that placed at 12 o'clock.
[0017] The sequencing between the actuation of the two locking systems also makes it possible to compensate for the adjustment and regulation tolerances of the linking means. Specifically, if it was envisaged to simultaneously control the two locking systems with the aid of the handle, that would require precise regulation and adjustment of the linking means between the two locking systems, which is particularly difficult with movable elements that are a distance apart. This also becomes very constraining with elements subjected to high temperature differences because of the effects of expansion of the materials and of the large dimensions of the elements. If the two locking systems are not controlled in an exactly simultaneous manner, the aforementioned risk of damage still remains when the nacelle is accidentally opened.
[0018] Finally, in the absence of sequencing, and in the event of poor regulation, the operator forces the whole line of control which has to be sized accordingly.
[0019] The sequencing therefore makes it possible to dispense with a precise regulation of the linking means, making the device safer and less costly in manufacturing and maintenance terms.
[0020] Advantageously, the sequencing means comprise a cam comprising a track interacting with a follower element moving along the latter, the track comprising an active portion and a passive portion so that the transformation of the pivoting movement of the cam into a displacement movement of the follower element, or vice versa, takes place over only the active portion of the track.
[0021] In this manner, when the handle is actuated, the follower element first moves over the passive portion so that the second locking system is not actuated. The follower element then reaches the active portion of the track and moves along this portion. The second locking system is then actuated along the whole displacement of the follower element over the active portion and moves from a locked state to an unlocked state, or vice versa. When the follower element has travelled over the active portion of the track, it then again reaches the passive portion and moves along the latter so that the second locking system is no longer actuated.
[0022] According to one feature of the invention, the linking means comprise a movable transmission member, comprising a first end connected to the first locking system and a second end connected to the cam, the actuation of the first locking system causing the translation by traction or compression of the transmission member.
[0023] According to one embodiment of the invention, the follower element is placed at the second end of the transmission member, the displacement of the follower element over the active portion of the track causing the pivoting of the cam, the second locking system comprising a bolt connected to the cam, actuated by the pivoting of the latter.
[0024] Therefore, the cam pivots only when the follower element is displaced along the active portion of the track, causing with it the displacement of the bolt. The cam therefore makes it possible to transform the displacement movement of the follower element into a movement of rotation of the cam and of displacement of the bolt.
[0025] Preferably, the bolt can be moved in translation and is fitted with a finger inserted into an oblong hole arranged in the cam.
[0026] The oblong hole makes it possible to compensate for the differences of trajectory between the linking zone of the cam with the bolt and the trajectory of the bolt. Specifically, the aforementioned linking zone moves on a curvilinear trajectory the center of which is the center of rotation of the cam while the bolt moves in a rectilinear manner.
[0027] According to another embodiment of the invention, the cam is arranged in order to pivot over a determined travel when the handle is displaced, the cam interacting with the second locking system so as to achieve its actuation over only a portion of the total travel of the cam.
[0028] Advantageously, the second end of the transmission member is connected to the cam so that the displacement of the transmission member rotates the cam, the second locking system comprising a bolt comprising the follower element, the pivoting of the cam causing the displacement of the follower element and of the bolt when the follower element is displaced over the active portion of the track.
[0029] The cam therefore makes it possible to transform the rotary movement of the cam into a displacement movement of the follower element and of the bolt, when the follower element reaches the active portion of the track.
[0030] According to one feature of the invention, the cam is mounted on the second locking system.
[0031] The invention also relates to a nacelle comprising at least one locking device according to the invention.
[0032] The invention also relates to an aircraft fitted with at least one nacelle according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In any case, the invention will be well understood with the aid of the following description with reference to the appended schematic drawing representing, as examples, several embodiments of this locking device.
[0034] FIG. 1 is an exploded schematic view, in perspective, of the nacelle fitted with locking devices according to the invention.
[0035] FIGS. 2 to 9 are views illustrating a first embodiment of the device, in which
[0036] FIG. 2 is a front view of the second locking system in a first position;
[0037] FIG. 3 is a front view of the first locking device, in the first position;
[0038] FIGS. 4-5 , 6 - 7 and 8 - 9 are views corresponding to FIGS. 2-3 , respectively in three successive positions of the locking device;
[0039] FIGS. 10 to 19 are views illustrating a second embodiment of the device, in which
[0040] FIGS. 10 and 11 are views corresponding to FIGS. 2 and 3 ;
[0041] FIGS. 12-13 , 14 - 15 , 16 - 17 and 18 - 19 are views corresponding to FIGS. 10-11 , respectively in four successive positions of the locking device;
[0042] FIGS. 20-29 are views illustrating a third embodiment of the device, corresponding respectively to FIGS. 10 to 19 .
DETAILED DESCRIPTION
[0043] FIG. 1 represents an exploded view of the rear section of a nacelle. The latter comprises, as is known to those skilled in the art, a first and second movable elements 1 , 2 , articulated at their top portion on a pylon of an aircraft, not shown.
[0044] Each articulated element 1 , 2 takes the general form of a hollow half-cylinder, delimiting two junction zones 3 , 4 with the articulated element facing it, namely a top junction zone 3 and a bottom junction zone 4 .
[0045] The bottom and top positions are also called respectively the 6 o′clock and 12 o′clock positions.
[0046] The nacelle is fitted with a first and a second locking device 5 , 6 .
[0047] It should be noted that, for reasons of presentation, only two of these devices are shown.
[0048] Each locking device 5 , 6 comprises a first locking system 7 and a second locking system 8 , connected to the first by linking means 9 arranged to actuate the second locking system 8 by the actuation of the first 7 .
[0049] Each locking system 7 , 8 is mounted on the first movable element 1 and is capable of being locked to a corresponding retention member 10 , 11 , mounted on the second movable element 2 .
[0050] The first and second locking systems 7 , 8 of each locking device 5 , 6 are mounted respectively in the bottom and top junction zones 4 , 3 of the first articulated element 1 .
[0051] The structure and the operation of the first locking device 5 according to a first embodiment of the invention will now be described in greater detail with reference to FIGS. 2 to 9 . 8
[0052] As shown in FIG. 3 , the first locking system 7 comprises a control handle 12 designed to be actuated by an operator. The handle 12 is mounted pivotingly on a shaft 13 and comprises an opening 14 . The first locking system 7 also comprises an element 15 having a hook 16 close to a first end and mounted pivotingly at a second end on the shaft 13 . This element 15 also has an oblong opening 17 in its middle portion, as can be seen more particularly in FIG. 7 . The hook 16 is designed to engage with the retention member 10 of the second articulated element 2 of the nacelle.
[0053] The first locking system 7 also comprises a link rod 18 articulated at a first and a second end about a first and a second shaft 19 , 20 protruding respectively into the opening 14 of the handle 12 and into the oblong opening 17 of the element 15 having the hook 16 . The shafts 19 , 20 can be moved inside each of the openings 14 , 17 . In addition, the second shaft 20 is fixed relative to the first articulated element 1 of the nacelle.
[0054] The first locking system 7 also comprises a movement-transformation member 21 mounted pivotingly on the shaft 13 and articulated on the first shaft 19 of the link rod 18 . The movement-transformation member 21 also comprises an arm 22 . The linking means comprise a flexible cable 9 symbolized by a line for reasons of clarity of the drawing. The cable 9 has a first and a second end, the first end being mounted articulated on the free end of the arm 21 .
[0055] As shown in FIG. 2 , the second locking system 8 comprises a body 23 that is fixed relative to the first articulated element 1 of the nacelle.
[0056] The body 23 comprises a slot 24 allowing the insertion of the corresponding retention member 11 , a bolt 25 being mounted movably in translation on the body, along an axis A perpendicular to the slot 24 , between a locked position in which the bolt 25 passes through the slot 24 or protrudes into the latter, as shown in FIG. 2 , and an unlocked position in which the bolt 25 is fully housed inside the body 23 and does not or virtually does not protrude into the slot 24 , shown in FIGS. 6 and 8 .
[0057] The bolt 25 comprises a post 26 protruding perpendicularly to the axis A and to the slot 24 , through an oblong opening 27 arranged in the body 23 along the axis A so as to allow the displacement of the bolt 25 .
[0058] The body 23 also comprises an oblong opening or a groove 28 extending obliquely relative to the slot 24 and to the oblong opening 27 , between a first end situated in the vicinity of the slot 24 and of the oblong opening 27 and a second end situated in the vicinity of an articulation shaft 29 the function of which is described below.
[0059] The locking device also comprises sequencing means comprising a cam 30 of elongated shape, comprising a first and a second end. The cam 30 is mounted pivotingly at its first end on the body 23 of the second locking system 8 , about the shaft 29 . The cam 30 also comprises an oblong hole 31 at its second end, the post 26 of the bolt 25 protruding into the oblong hole so that the latter extends substantially perpendicularly to the axis A of displacement of the bolt 25 .
[0060] The cam 30 also comprises a track 32 formed by an oblong opening in the general shape of a staircase step. The track 32 therefore has three successive portions, namely a first passive portion 33 , a second active portion 34 and a third passive portion 35 , the function of which is given in detail below.
[0061] The cable 9 , shown schematically by a line, comprises a finger 36 at its second end, the finger 36 being inserted into the track 32 of the cam 30 and into the groove 28 of the body 23 so as to form a follower element.
[0062] Described below are the successive steps for opening the locking device, illustrated in FIGS. 2 to 9 .
[0063] FIGS. 2 and 3 represent the locked position of the latter, in which the first and second locking systems 7 , 8 are both locked. In this position, the handle 12 is in the closed position, that is to say brought closer to the element 15 having the hook 16 , the follower finger 36 being situated in the first passive portion 33 of the track 32 , at the end of the track. The cam 30 is placed in a first angular position in which the bolt 25 which is connected to it is in the top position, that is to say passes through the slot 24 .
[0064] As shown in FIGS. 4 and 5 , when the user actuates the handle 12 in order to open it, the arm 22 pivots in the counterclockwise direction in order to displace the cable 9 in translation, by pulling on the latter. The follower finger 36 is then displaced along the first passive portion 33 of the track 32 . During this displacement, the cam 30 does not pivot, the first passive portion 33 of the track 32 coinciding then with the groove 28 arranged in the body 23 .
[0065] When the operator continues to actuate the handle 12 , the first shaft 19 of the link rod 18 butts against the edge of the opening 14 of the handle 12 and is operated by the movement of the latter. The link rod 18 is then displaced so that the second shaft 20 of the latter translates in the oblong opening 17 of the element 15 comprising the hook 16 .
[0066] The aforementioned second shaft 20 being fixed, the element 15 comprising the hook 16 is displaced so that the retention element 10 begins to disengage from the hook 16 . In this position, the first locking system 7 is still locked since the retention element 10 is not completely disengaged from the hook 16 .
[0067] Continuing the opening movement of the handle, the arm 22 continues to translate the cable 9 so that the follower finger 36 is displaced along the second active portion 34 of the track 32 , from one end to the other of the latter. As seen above, the second active portion 34 is oriented obliquely relative to the first passive portion 33 and the follower finger 36 is inserted into the groove 28 of the fixed body 23 . The cam 30 is therefore rotated in the counterclockwise direction about the shaft 29 and displaces the bolt 25 in the bottom position. During this displacement, the post 26 of the bolt 25 translates in the oblong hole 31 of the cam 30 , which makes it possible to compensate for the differences in trajectories between the curvilinear trajectory of the end of the cam 30 attached to the bolt 25 and the rectilinear trajectory A of the latter.
[0068] As shown in FIG. 6 , the bolt 25 is disengaged from the slot 24 when the follower finger 36 has traversed the active portion 34 of the track 32 . Therefore, the second locking system 8 is unlocked even when the first 7 is still locked, because the retention member 10 is still engaged in the hook 16 .
[0069] As shown in FIGS. 8 and 9 , when the operator continues to actuate the handle 12 , the retention element 10 is completely disengaged from the hook 16 so that the first locking system 7 is unlocked. As above, the arm 22 continues to translate the cable 9 so that the follower finger 36 is displaced along the third passive portion 35 of the track 32 . This passive portion 35 then extends along the axis of the groove 28 of the body 23 so that the displacement of the follower finger 36 does not cause the pivoting of the cam 30 . Consequently, the bolt 25 is not displaced.
[0070] Therefore, as described above, the first locking device is sequenced. Specifically, when the handle 12 is opened, the operator first unlocks the second locking system 8 , then the first locking system 7 . This prevents the operating errors explained in the introduction part.
[0071] It will be easy to understand that, when the handle 12 is closed, the operator first locks the first locking system 7 and then locks the second locking system 8 .
[0072] FIGS. 10 to 19 illustrate a second embodiment also corresponding to the first locking device the position of which in the nacelle is shown in FIG. 1 .
[0073] To make it easier to understand, the elements have been designated by the same reference numbers as before.
[0074] As appears in FIG. 11 , the first locking system has a structure similar to that illustrated in FIG. 3 .
[0075] The second locking system is shown in FIG. 10 . As before, the bolt 25 is mounted so as to be able to be displaced in the body 23 , the post 26 protruding outward from the bolt 25 . In addition, the cam 30 is also mounted pivotingly about the shaft 29 .
[0076] In this embodiment, the cam 30 has a general shape of a quarter of a disk, comprising a first and a second adjacent edge 37 , 38 substantially forming a right angle relative to one another, connected via a peripheral edge 39 in the arc of a circle.
[0077] The cam 30 is mounted pivotingly close to the right-angle zone.
[0078] The first edge 37 comprises, close to the right-angle zone, a lug 38 protruding outward, the free end of which is connected via an articulation shaft 39 to the second end of the cable 9 .
[0079] Consequently, the displacement of the cable 9 causes the cam 30 to pivot about the shaft 29 .
[0080] As before, the cam 30 comprises a track 32 in the form of an opening, having an active portion 34 and a passive portion 35 .
[0081] The passive portion 35 of the track 32 extends in a parallel arc of a circle set back from the peripheral edge 39 of the cam 30 and of which the center corresponds to the shaft 29 . The active portion 34 of the track 32 extends substantially parallel to the first edge 37 of the cam 30 , from the passive portion 35 so as to form a continuous track.
[0082] The post 26 of the bolt 25 is inserted into the track 32 and thus forms a follower element.
[0083] As is shown successively in FIGS. 10 to 15 , the opening of the handle 12 by the operator makes it possible to exert traction on the cable 9 via the arm so that the cable 9 rotates the cam 30 in the counterclockwise direction. During this rotation, the post 26 of the bolt 25 is displaced along the active portion 34 , translating the bolt 25 downward so as to open the second locking system 8 .
[0084] FIG. 16 represents the second locking system 8 in the completely unlocked position in which the follower post 26 , having traversed all of the active portion 34 of the track, enters the passive portion 35 . It is then possible to engage or disengage the retention member 11 fixed to the second movable portion 2 of the nacelle.
[0085] From this position, when the operator continues to open the handle 12 and consequently to pivot the cam 30 , the follower post 26 is displaced in the passive portion 35 of the track 32 . This displacement does not cause the displacement of the bolt 25 .
[0086] As above, when the handle is displaced over the whole of its travel, as shown in FIGS. 18 and 19 , the hook 16 is completely disengaged from the corresponding retention element 10 so as to unlock the first locking system 7 .
[0087] This second embodiment therefore also allows sequencing between the actuation of the first and of the second locking system 7 , 8 so that, when the handle 12 is opened, the operator first unlocks the second locking system 8 and then unlocks the first locking system 7 .
[0088] As above, the locking of this device is obtained by the inverse succession of the aforementioned steps.
[0089] A third embodiment is illustrated in FIGS. 20 to 29 . This third embodiment corresponds to the second locking device 6 the position of which is illustrated in FIG. 1 . For easier understanding, the elements have been designated by the same reference numbers as before.
[0090] The first locking system 7 is shown in FIG. 21 . The latter comprises a body 40 that is fixed relative to the movable element 1 and is fitted with a bolt 41 mounted so as to be displaceable in translation on the body, capable of being displaced between a first locked position shown in FIG. 21 in which the bolt 41 traverses a slot 42 designed for the insertion of the corresponding retention member 10 , and an unlocked position shown in FIG. 29 in which the bolt 41 is retracted relative to the slot 42 .
[0091] The translation of the bolt 41 is actuated by the user, via a handle 12 , shown in FIG. 1 , connected to the bolt 41 by a rod 43 .
[0092] The second locking device 6 also comprises a movement-transformation member 44 , mounted on the first locking system 7 , making it possible to transform the translation movement of the handle 12 and of the bolt into a translation movement by traction or compression of the cable 9 .
[0093] The movement-transformation element 44 is of elongated shape, comprises a first end mounted pivotingly on the body 40 of the first locking system, about a shaft 45 , and comprises a second end at which an opening 46 is arranged. According to one embodiment, the opening 46 comprises a passive portion and an active portion.
[0094] In addition, the bolt 41 comprises a follower post 47 protruding into the opening 46 .
[0095] The movement-transformation element 44 also has an arm 48 protruding outward at the first end, the free end of the arm being connected to the first end of the cable 9 .
[0096] The second locking system 8 is illustrated in FIG. 20 . In this embodiment, the cam 30 is mounted pivotingly about the shaft 29 , the second end of the cable 9 being connected to the cam 30 at the shaft 39 .
[0097] The track 32 of the cam 20 has a shape similar to that of the second embodiment, that is to say comprises a passive portion 35 in the shape of an arc of a circle the center of which corresponds to the pivot shaft 29 of the cam 30 , from which a straight active portion 34 extends.
[0098] The operation and the movement sequence of the second locking system 8 of this third embodiment of the invention are similar to those of the second embodiment described above.
[0099] The operation of the second locking device 6 will now be described below.
[0100] When the user pulls on the control handle 12 , the bolt is displaced downward, rotating the movement-transformation element 44 in the counterclockwise direction. The latter then translates the cable 9 connected to the cam 30 . The latter is therefore rotated in the counterclockwise direction, the follower post 26 of the bolt 25 traversing the active portion 34 of the track 32 so as to displace the bolt 25 downward, that is to say so as to unlock the second locking system 8 . The active portion 34 is extended by an overtravel forming an additional passive portion, necessary in order to compensate for the positioning differences between the various components.
[0101] This position is shown in FIG. 26 . The travel of the bolt 41 of the first locking system 7 and the shape of the opening 46 of the movement-transformation element 44 are arranged so that only a portion of the travel of the handle 12 necessary for completely opening the first locking system 7 is sufficient for the follower post 26 to traverse the active portion 34 of the track 32 , that is to say to unlock the second locking system 8 .
[0102] When the user continues to pull on the handle 12 , the bolt 41 continues its translation movement downward until the latter reaches the unlocked position shown in FIG. 29 . During this movement of the handle 12 , the cam 30 is pivoted so that the follower finger 26 of the bolt 25 of the second locking system 8 is displaced along the passive portion 35 of the track 32 , the bolt 25 then not being displaced in translation.
[0103] As above, the unlocking of the second locking device is achieved in a sequenced manner, the locking being obtained by the inverse succession of the aforementioned steps.
[0104] As it goes without saying, the invention is not solely limited to the embodiments of this locking device that have been described above as examples, but on the contrary it covers all the variants. | The invention relates to a locking device ( 5, 6 ) comprising a first locking system ( 7 ) equipped with a control handle ( 12 ), intended to be actuated by an operator, characterized in that it includes a second locking system ( 8 ) connected to the first ( 7 ) by linking means ( 9 ) designed to actuate the second locking system ( 8 ) because of the actuation of the first ( 7 ), the first locking system ( 7 ) being actuated alternately between a locked state and an unlocked state by movement of the handle ( 12 ) over the totality of a defined course, the linking means ( 9 ) having sequencing means designed to actuate the second locking system ( 8 ), between a locked state and an unlocked state thereof respectively, during the displacement of the handle ( 12 ) over only part of the travel of the latter. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates to methods of electrolytic precipitation of a metal oxide. In particular, the invention relates to electrolytic precipitation of titanium dioxide (TiO 2 ).
BACKGROUND OF THE INVENTION
[0002] Metal oxides such as titanium dioxide and zinc oxide are commonly used in several industrial fields. For example, TiO 2 is used as an opacifier and/or white pigment in the coatings industry, as filler material in plastics, and as a photocatalyst for removing environmental pollutants. In the coatings industry, TiO 2 pigments provide efficient scattering of light to impart brightness and opacity. Titanium dioxide is typically commercially available in the anatase and rutile crystalline forms. Rutile TiO 2 is particularly desired because it scatters light more effectively and is more durable than the anatase form.
[0003] TiO 2 (rutile and anatase) has traditionally been produced by two commercial processes, referred to as the “sulfate process” in which titanium ore is treated with sulfuric acid followed by crystallization and precipitation of TiO 2 and the “chloride process” in which titanium ore is treated with chlorine gas to produce an intermediate of TiCl 4 , which is oxidized to form TiO 2 . The cost of producing TiO 2 from these traditional processes has increased significantly and alternative routes for obtaining TiO 2 are being sought.
SUMMARY OF THE INVENTION
[0004] The present invention includes a method of producing metal oxide particles, comprising electrodepositing a metal oxide from an electrolyte solution onto a substrate to coat at least a portion of the substrate, whereby metal oxide seed particles are released into the solution; and precipitating metal oxide particles from the solution. Also included in the present invention is a pigment composition comprising rutile TiO 2 particles, wherein the particles are produced by electrolytic precipitation from an electrolyte composition comprising titanium oxychloride (TiOCl 2 ).
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a scanning electron microscope image of TiO 2 particles produced according to the present invention; and
[0006] FIG. 2 is a scanning electron microscope image of TiO 2 particles produced according to the prior art.
DETAILED DESCRIPTION OF THE INVENTION
[0007] For purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements.
[0008] Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.
[0009] In this application, the use of the singular includes the plural and plural encompasses singular, unless specifically stated otherwise. In addition, in this application, the use of “or” means “and/or” unless specifically stated otherwise, even though “and/or” may be explicitly used in certain instances.
[0010] In one embodiment of the present invention, metal oxide particles are obtained in an electrolytic process in which a cathode (which may be composed of stainless steel) is electroplated with a metal oxide using a non-consumable anode (which may be composed of stainless steel or graphite). In an electrolytic cell containing an electrolyte solution, upon application of an electric current to the anode, the metal oxide plates out onto the cathode. The metal oxide formed on the cathode then seeds precipitation of metal oxide particles from the electrolyte solution.
[0011] Metal oxides that can be electrodeposited onto a substrate and precipitate as metal oxide particles include oxides of alkaline earth metals (such as magnesium), transition metals (such as titanium and zirconium) and rare earth metals (such as cerium). The metal oxide forms on the cathode of an electrolytic cell, where the cell contains an aqueous solution of a salt of the metal.
[0012] In one embodiment, a soluble salt of titanium can be electrodeposited from an electrolytic solution onto a cathode as TiO 2 and precipitated therefrom. A suitable soluble salt of titanium is TiOCl 2 . Other soluble salts of metals can be use to electrodeposit a metal oxide onto a substrate, such as zirconium oxide (ZrO 2 ) electrodeposited from a solution of zirconium oxychloride (ZrOCl 2 ). In general, suitable metals and soluble salts thereof useful in practicing the present invention may be those that form a coordination complex, also referred to as a Werner complex, or, as will be understood by those skilled in the art, are otherwise selected to electrodeposit as a metal oxide. As such, it should be appreciated that while the present invention is described in reference to electrolytic precipitation of TiO 2 , other metal oxides may be electrolytically precipitated according to the present invention from suitable aqueous solutions of salts of those metals.
[0013] It has been found that upon electrolytic deposition of TiO 2 from an electrolyte solution onto a substrate (the cathode), TiO 2 seed particles are released from the deposited TiO 2 into the solution and precipitate as TiO 2 particles, typically sized less than 1 micron. The electrolyte solution includes a soluble salt of titanium, such as TiOCl 2 and may further include a reducing agent. Suitable reducing agents include oxidizing anions, such as an alkali nitrate, e.g. sodium nitrate.
[0014] It has been found that TiO 2 particles will precipitate from electrolyte solutions containing 10 to 360 grams per liter (g/L) TiOCl 2 and 5 to 150 g/L sodium nitrate. By way of small scale example using a wire as a cathode, current densities of 0.3 to 1.5 amperes per square centimeter (A/cm 2 ) are sufficient to accomplish precipitation of TiO 2 according to the present invention. Electrolytic cell design and operating parameters thereof for larger scale production of metal oxides via the electrolytic precipitation method of the present invention will be appreciated by one skilled in the art. It has been found that the temperature of the electrolyte solution may be adjusted to control the particle size and particle size distribution of the precipitated TiO 2 particles. For example, in one embodiment, when the electrolyte solution is less than 150° F., the precipitated TiO 2 particles have a maximum dimension of less than 1 micron, such as 100-700 nm or 250-300 nm or 100-250 nm. The precipitated TiO 2 is produced as discrete particles (either directly or with milling) in the rutile form that are substantially in the shape of a sphere or spheroid, meaning that the particles appear to the eye as being spherical or spheroid.
[0015] While TiO 2 may precipitate from a solution at elevated temperatures (over 150° F., typically at 185° F. or higher) without application of an electric current thereto, the resulting material normally forms agglomerates of particles, with the particles within the agglomerates having a primary particle size of over 1 micron, such as above 1.5 microns, which is unsuitable for use in coating applications and other end-uses. In the present invention, not only are the precipitated metal oxide particles discrete, the particle size may be tailored by adjusting the electrolyte solution temperature. For example, at electrolyte solution temperatures of 145° F., the average particle size of the discrete precipitated TiO 2 particles may be 100-250 nm.
[0016] The precipitated TiO 2 produced according to the present invention may be included in conventional end-uses for TiO 2 as a complete or partial replacement of TiO 2 obtained by conventional processes and may be surface treated as is conventional in producing TiO 2 for industrial use. Such surface treatment may enhance the compatibility of the precipitated TiO 2 in coating systems, including aqueous and non-aqueous coating compositions.
EXAMPLES
[0017] The following Examples are presented to demonstrate the general principles of the invention. All amounts listed are described in parts by weight, unless otherwise indicated. The invention should not be considered as limited to the specific Examples presented.
Example 1
[0018] A solution was made by adding 400 grams of deionized water into a glass beaker with a magnetic stir bar, and 100 grams of TiOCl 2 (available from Millennium Chemicals, Inc.) was slowly added to the deionized water. The solution was placed onto a magnetic stir plate capable of heating and agitation, then 40 grams of NaNO 3 (available from Acros Chemicals) was added to the solution and agitated for 15 minutes, giving a clear colorless solution. An electrolytic cell was applied to the solution. To the glass beaker, a four inch long ER316L 1/16″ stainless welding rod was suspended in solution and connected to a power source as a cathode. A graphite bar (1 inch wide by 4 inches long) was suspended in the solution and connected as the anode. The glass beaker with solution, cathode and anode was placed into a water bath and under agitation the solution was heated to 130° F. At 130° F. the solution was then electrified by passing 3.5 amps and 25 volts for 300 seconds. The maximum voltage achieved was 4.67 volts during the deposition process. Following deposition the bath temperature reached 139° F. and turned from clear colorless to light yellow. The solution was heated to 145° F. and the light yellow solution turned cloudy light yellow. The solution was removed from heat and agitation at 168° F. and cooled to room temperature. Upon cooling a white precipitate formed from the cloudy light yellow solution. The precipitate was evaluated by scanning electron microscope (SEM) and an average particle size of 100-250 nm was observed as shown in the SEM image of FIG. 1 .
Comparative Example
[0019] Example 1 was repeated but without use of the electrolytic cell. The glass beaker with solution was placed into a water bath, and the solution was heated under agitation. At 145° F., the solution turned from clear colorless to clear slightly yellow and increased in yellow color until the solution turned a cloudy milky yellow color at 185° F. The solution was removed from heat and agitation at 185° F. and cooled to room temperature. Upon cooling, a white precipitate formed from the cloudy milky yellow solution. The precipitate was evaluated by SEM and aggregates of particles having an average particle size of 1.5 μm was observed as shown in the SEM image of FIG. 2 . Milling the aggregates did not produce smaller discrete particles.
[0020] While the preferred embodiments of the present invention are described above, obvious modifications and alterations of the present invention may be made without departing from the spirit and scope of the present invention. The scope of the present invention is defined in the appended claims and equivalents thereto. | Disclosed is a method of producing metal oxides, comprising electrodepositing a metal oxide from an electrolyte solution onto a substrate to coat at least a portion of the substrate, whereby metal oxide seed particles are released into the solution, and precipitating metal oxide particles from the solution. The precipitated metal oxide particles have a maximum particle size of less than 1 micron. | 8 |
BACKGROUND-FIELD OF INVENTION
The present invention relates to a flow control/shock absorbing seal for controlling the flow of liquids and absorbing the shocks during transportation of the liquid.
BACKGROUND-DESCRIPTION OF RELATED ART
Containers that enclose liquids to be stored and transported must be leak-proof and yet must open easily for access to its contents. During transportation of the containers, the liquid in the containers may experience shock and the resulting pressure may rupture the containers and/or cause the liquid to leak from the containers. Furthermore, when the containers are opened for access to their contents, there is no control over the rate of the flow of the liquid from the containers. There is no economical and accurate method of presetting the rate of flow of the liquids from the containers.
SUMMARY OF THE INVENTION
The present invention is a flow control/shock absorbing seal that will absorb the shocks transmitted to the liquids in a container during transportation to prevent leakage and maintain the separation of the liquid and the air chamber in the container and controls the rate of flow of the liquid from the container after opening. The present invention allows the rate of flow of the liquid from the container to be predetermined and controlled economically and accurately. The present invention may also allow the forced ejection of the liquid from the container.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the flow control/shock absorbing seal 1 inserted in one end 4 of the container that can only be opened from the end 5 of the container containing the liquid 2 .
FIG. 2 shows the flow control/shock absorbing seals 1 , 11 inserted in both ends 4 , 5 of the container that can be opened at either end 4 , 5 of the container.
FIG. 3 shows the flow control/shock absorbing seal 12 inserted in the container separating the container into two air chambers 13 , 14 that can be opened at either end 4 , 5 of the container.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the preferred embodiment of the flow control/shock absorbing seal 1 . A flow control/shock absorbing seal 1 is inserted in one end 4 of a long slender cylindrical container that can be opened from the end 5 with the liquid 2 . The container is partially filled with the desired liquid 2 such as medications, mouthwash, mint, or any other chemicals. The flow control/shock absorbing seal 1 is inserted at one end 4 of the container enclosing the liquid 2 . A predetermined air chamber 3 is maintained on the end 4 of the container with the flow control/shock absorbing seal 1 separated from the liquid 2 by the flow control/shock absorbing seal 1 . The container is sealed on both ends 4 , 5 so that no leakage of the liquid 2 is possible. The container can be broken open at predetermined location 6 in the liquid 2 portion of the container at the scoring placed outside perimeter of the container at the predetermined location 6 .
During transportation, the flow control/shock absorbing seal 1 will resist movement of the liquid 2 and dampen any shock it may experience by transferring the pressure to the air in the air chamber 3 and dissipate the pressure and maintain containment of the liquid 2 . When the liquid 2 is to be release from the container, it is broken open at the predetermined locations 6 determined by the scorings on the container. Once the container is opened, the liquid 2 may be sucked out of the container by the vacuum created by the end user's mouth placed at the open end 5 of the container.
The container may also be sealed in an environment with above normal air pressure which will create a pressurized air chamber 3 . The liquid 2 is incompressible. The air in the air chamber 3 will be pressurized to the same pressure as the pressurized environment it was sealed in. The flow control/shock absorbing seal 1 will maintain the separation of the air chamber 3 and the liquid 2 . The flow control/shock absorbing seal 1 will also dampen the shocks experienced during transportation by transferring the pressure to the air in the air chambers 3 . The container is sealed on both ends 4 , 5 so that no leakage of the liquid 2 is possible. The container can break open at predetermined location 6 in the liquid 2 portion of the container by scoring the outside perimeter of the container at the predetermined location 6 .
During transportation, the flow control/shock absorbing seal 1 will resist movement of the liquid 2 and dampen any shock it may experience by transferring the pressure to the air in the air chamber 3 and dissipate the pressure and maintain containment of the liquid 2 . When the liquid 2 is to be release from the container, it is broken open at the predetermined location 6 determined by the scorings on the container. Once the container is opened, the liquid 2 will be forced out of the container by the air pressure in the air chamber 3 at a rate determined by the air pressure and the viscosity and the length of the flow control/shock absorbing seal 1 . A higher viscosity and/or longer flow control/shock absorbing seal 1 will allow the liquid 2 to flow out of the container after a predetermined delay and at a slow controlled speed. A lower viscosity and/or shorter flow control/shock absorbing seal 1 will allow the liquid 2 to flow out of the container almost immediately and at a rapid speed. The amount of liquid 2 to be release can be determined by breaking the end 5 of the container containing the liquid 2 at predetermined location 6 . The end 5 containing the liquid 2 that breaks off from the container will retain the liquid 2 within it since it is sealed on one end 5 and atmospheric air pressure will prevent the liquid 2 contained within it from being released.
FIG. 2 shows another embodiment of the flow control/shock absorbing seal 1 , 11 . A flow control/shock absorbing seal 1 , 11 is inserted in each end 4 , 5 of a container that can be opened from both ends 4 , 5 . The container is partially filled with the desired liquid 2 such as medications, mouthwash, mint, or any other chemicals. The two flow control/shock absorbing seals 1 , 11 are inserted at both ends 4 , 5 of the container enclosing the liquid 2 . A predetermined air chamber 7 , 8 is maintained on both ends 4 , 5 of the container separated from the liquid 2 by the flow control/shock absorbing seals 1 , 11 . The container is sealed on both ends 4 , 5 so that no leakage of the liquid 2 is possible. The container can break open at predetermined locations 9 , 10 in the air chambers 7 , 8 at the scoring placed at the outside perimeter of the container at the predetermined locations 9 , 10 .
During transportation, the flow control/shock absorbing seals 1 , 11 will resist movement of the liquid 2 and dampen any shock it may experience by transferring the pressure to the air in the air chambers 7 , 8 and dissipate the pressure and maintain containment of the liquid 2 . When the liquid 2 is to be release from the container, it is broken open at the predetermined locations 9 , 10 determined by the scorings on the container. Once both end of the container are opened, the liquid 2 will flow out of the container at a rate determined by the viscosity and the length of the flow control/shock absorbing seals 1 , 11 . A higher viscosity and/or longer flow control/shock absorbing seal 1 , 11 will allow the liquid 2 to flow out of the container after a predetermined delay and at a slow controlled speed. A lower viscosity and/or shorter flow control/shock absorbing seal 1 , 11 will allow the liquid 2 to flow out of the container almost immediately and at a rapid speed. No liquid 2 is wasted or leaked since the openings are at the air chambers 7 , 8 and the flow control/shock absorbing seals 1 , 11 will contain the liquid 2 in the container until the container is opened at both ends 4 , 5 and the weight of the liquid 2 forces its way through the flow control/shock absorbing seal 1 or 11 .
The container may be sealed in an environment with above normal air pressure which will create pressurized air chambers 7 , 8 . The liquid 2 is incompressible. The air in the air chambers 7 , 8 will be pressurized to the same pressure as the pressurized environment it was sealed in. Since there are air chambers 7 , 8 in both ends 4 , 5 of the container, the liquid 2 will maintain its position in the middle of the container. The flow control/shock absorbing seals 1 , 11 will maintain the separation of the air chamber 7 , 8 and the liquid 2 . The flow control/shock absorbing seals 1 , 11 will also dampen the shocks experienced during transportation by transferring the pressure to the air in the air chambers 7 , 8 .
When the liquid 2 is to be release from the container, either end 4 or 5 of the container may be broken open. Once the container is open, the air pressure in the air chamber 7 or 8 at the unopened end of the container will force the liquid 2 out of the container at a predetermined rate after a predetermined delay. The liquid 2 will flow out of the container at a rate determined by the viscosity and the length of the flow control/shock absorbing seals 1 , 11 . A higher viscosity and/or longer flow control/shock absorbing seal 1 , 11 will allow the liquid 2 to flow out of the container after a predetermined delay and at a slow controlled speed. A lower viscosity and/or shorter flow control/shock absorbing seal 1 , 11 will allow the liquid 2 to flow out of the container almost immediately and at a rapid speed. No liquid 2 is wasted or leaked since the opening is at the air chamber 7 or 8 and the flow control/shock absorbing seals 1 , 11 will contain the liquid 2 in the container until the container is opened.
FIG. 3 shows another embodiment of the flow control/shock absorbing seal 12 . A flow control/shock absorbing seal 12 is inserted in the container that can be opened from both ends 4 , 5 . A predetermined air chamber 13 , 14 is maintained on both ends 4 , 5 of the container separated by the flow control/shock absorbing seal 12 . The container is sealed in a partial vacuum or negative pressure environment on both ends 4 , 5 . After the container is sealed on both ends 4 , 5 , the air chambers 13 , 14 will have a partial vacuum or negative pressure. The container can be broken open at predetermined locations 15 , 16 in the air chambers 13 , 14 at the scoring placed at the outside perimeter of the container at the predetermined locations 15 , 16 .
The resulting container may be used to collect liquid samples easily. To use the container to collect liquid samples such as saliva or other body fluids for medical examinations, the container is broken open at one of the predetermined locations 15 determined by the scorings on the container and placed in contact with the liquid to be collected thereby sealing the opened end 4 . Once the container is opened at one end 4 , the vacuum in the air chamber 14 in the other end 5 of the container would slowly move the flow control/shock absorbing seal 12 toward the still closed end 5 after a predetermined delay which would allow sufficient time to place the container in contact with the liquid to be collected. The movement of the flow control/shock absorbing seal 12 would create a vacuum at the opened end 4 of the container and thereby suck the liquid into the container and retain it in the container. When the collected liquid is to be released from the container, the other still closed end 5 is broken open at the predetermined location 16 , allowing air to enter the air chamber 14 thereby balancing the partial vacuum or negative pressure in the air chamber 14 . When atmospheric air enters the air chamber 14 , the collected liquid will then be slowly released after a predetermined delay. The collected liquid will flow into and out of the container at a rate determined by the viscosity and the length of the flow control/shock absorbing seal 12 . A higher viscosity and/or longer flow control/shock absorbing seal 12 will allow the collected liquid to flow into and out of the container after a predetermined delay and at a slow controlled speed. A lower viscosity and/or shorter flow control/shock absorbing seal 12 will allow the collected liquid to flow into and out of the container almost immediately and at a rapid speed. | The present invention is a flow control/shock absorbing seal that will absorb the shocks transmitted to the liquids in a container during transportation to prevent leakage and maintain the separation of the liquid and the air chamber in the container and controls the rate of flow of the liquid from the container. The present invention allows the rate of flow of the liquid from the container to be predetermined and controlled economically and accurately. The present invention may also allow the forced ejection of the liquid from the container. | 1 |
TECHNICAL FIELD
[0001] An example embodiment pertains generally to a device for handling baked products (e.g., cookies, biscuits, biscotti and rusks) and a method of use and manufacturing thereof. More specifically, an example embodiment relates to a device and method by which a baked product is produced to enable such a baked product to be dunked into coffee, tea, milk or other liquids without the user's hand having to contact the liquid.
BACKGROUND
[0002] The act of dunking (or dipping) a cookie in milk is a popular way many people enjoy eating their cookie today especially amongst the younger demographics. The cookie is soaked in the milk for a period of time to allow for the milk to be absorbed before eaten.
[0003] While cookies are a popular sweet used for dunking, there are many other hard baked biscuits including but not limited to biscotti and rusks (South African biscuit), that people can enjoy by dipping or dunking the baked biscuit into a cold or warm liquid substance to absorb the substance's flavor and soften the biscuit.
[0004] While dunking a cookie or biscuit is common today, there are many drawbacks. When dunking a cookie or biscuit, most users will use their fingers to hold the cookie when dunking it into a liquid. If the person dunks the cookie or biscuit in a hot liquid such as coffee or tea, the danger exists that the hot liquid may burn their fingers.
[0005] There have been several attempts to develop devices that can be used to hold a cookie for the purpose of dunking the cookie into a liquid (milk being the most common liquid). Three examples of such devices are described in (a.) U.S. Pat. No. D0544764 titled “Food Holding Implement,” (b.) U.S. Pat. No. 7,090,269 titled “Culinary Apparatus,” and (c.) US Patent Publication No. 20050109222 titled “Cookie Handling Device.”
[0006] The device discussed in U.S. Pat. No. D0544764 was specifically designed for sandwich-type biscuits, where a layer of ‘cream’ or icing is sandwiched between two biscuits. The device then functions like tongs that grabs onto the soft inner layer of the biscuit before dunking the biscuit into milk. A disadvantage of this approach is that the use of the device is limited to these “sandwich-type biscuits.” Another disadvantage is the fact that the biscuit can easily become dislodged from the device when the biscuit absorbs the milk when dunked. Yet another disadvantage is the fact that the device is provided separate from the biscuit and therefore makes it inconvenient to always have the device handy when dunking a biscuit.
[0007] The device discussed in U.S. Pat. No. 7,090,269 was designed to address the problem of a biscuit breaking up when dunked into a liquid, and discusses implementing a container like holder at the end of a tong device. The disadvantage of this device is that removing the biscuit from the “container like holder,” after being dunked into a liquid, can easily cause the biscuit to break up and therefore making it difficult and messy to eat. Another disadvantage is the fact that the device is provided separate from the biscuit and therefore makes it inconvenient to always have the device handy when dunking a biscuit.
[0008] The device discussed in US Patent Publication No. 20050109222 was specifically designed for sandwich-type biscuits, where a layer of ‘cream’ or icing is sandwiched between two biscuits, but was intended as to improve on both the devices discussed in U.S. Pat. No. D0544764 and device discussed in U.S. Pat. No. 7,090,269. This device allows the user to partially insert the device into the soft inner layer between the two biscuits before dunking the biscuit into a liquid. The disadvantage of this approach is the fact that the use of the device is limited to “sandwich-type biscuits” and strictly relies on the fact that the biscuit has a soft inner layer. Another disadvantage is the fact that the device is provided separately from the biscuit and therefore makes it inconvenient to always have the device handy when dunking a biscuit.
[0009] The devices discussed above all have significant disadvantages that make them difficult, and in most cases impossible, to use when dunking any cookie or biscuit other than the sandwich-type biscuit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Various exemplary embodiments are shown and described in reference to the drawings. It will be appreciated that the embodiments shown are illustrative but not limited to the scope of the invention, which is set forth in the claims.
[0011] FIG. 1 shows a perspective view of the dunking stick in accordance with one exemplary embodiment.
[0012] FIG. 1 a shows the perspective view of the dunking stick and outlines the part of the dunking stick that is baked into the cookie or biscuit.
[0013] FIG. 1 b shows the perspective view of the dunking stick with marketing or branding information in accordance with an exemplary embodiment.
[0014] FIG. 1 c shows the perspective view of cookies or biscuits in a baking pan with the embedded dunking sticks in accordance with an exemplary embodiment.
[0015] FIG. 1 d shows an illustration of the dunking stick, in accordance with an exemplary embodiment, being used to dunk a biscuit.
[0016] FIG. 2 shows another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0017] FIG. 2 a shows yet another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0018] FIG. 2 b shows yet another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0019] FIG. 2 c shows yet another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0020] FIG. 2 d shows yet another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0021] FIG. 3 shows yet another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0022] FIG. 3 a shows yet another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0023] FIG. 3 b shows yet another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0024] FIG. 3 c shows yet another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0025] FIG. 3 d shows yet another embodiment of a dunking stick in accordance with an exemplary embodiment.
[0026] FIG. 4 shows a flowchart of a method 400 of manufacturing (baking) in accordance with an exemplary embodiment.
[0027] FIG. 5 shows a flowchart of a method 500 of a baked product dunking process in accordance with an exemplary embodiment.
[0028] FIG. 6 is a photograph of a baking product assembly, according to an exemplary embodiment.
DETAILED DESCRIPTION
[0029] The drawings will now be discussed in reference to the numerals provided thereon so as to enable one skilled in the art to make and use the present invention. It will be appreciated that the drawings and descriptions thereof are for explanatory purposes and are not intended to narrow the scope of the appended claims.
[0030] Example embodiments provide improved methods for manufacturing a baked product for a dunking or immersion in a liquid, a baked product for dunking or immersion in a liquid, and method of dipping or dunking or otherwise immersing a baked product (e.g., a baked product) in a liquid.
[0031] Example embodiments include a method of manufacturing a baked product assembly, the method including inserting a support member (or other support or ripping device) into the dough prior to or during a baking process. The support member remains inserted into the dough throughout the baking process to become part of the final baked product assembly. The support member is used by consumers to dunk the baked product assembly into a liquid prior to eating the baked product off the support member. Furthermore, example embodiments may allow consumers to eat the baked product without touching it with their fingers, when the baked product is dunked. Example methods may include inserting the support member (e.g., a dunking stick) into the baked product as part of the baking process. In various example embodiments, the support member material may consist of any material suitable for the baking process including but not limited to wood, plastic or metal. The positioning of the support member relative to the baked product assembly can vary based on shape and size of the baked product assembly. The depth to which the support member is inserted into the baked product can vary.
[0032] In accordance with yet another aspect, the size of the support member can vary in width, length and thickness. Additionally, the support member may not have a uniform shape.
[0033] In accordance with yet another aspect, the part of the support member (e.g., a blade portion) that is inserted into the baked product can vary in design and shape to allow for a better grip inside the baked product based on the texture and consistency of the baked product.
[0034] In accordance with yet another aspect, the support member may carry advertising.
[0035] Referring now to FIG. 1 , there is shown a perspective view of an embodiment of a support member, in the exemplary form of a dunking stick 10 . The dunking stick 10 can be made from various materials including but not limited to ceramics, wood, plastic or metal. As will be described in further detail below, in one exemplary embodiment, the dunking stick 10 is inserted into the dough that forms the baked product 30 before or during the baking process. For the purposes of the current specification, the combination of the support member and baked product 30 (whether in a baked or pre-baked state) shall be referred to as a baked product assembly. It will be appreciated that the dunking stick 10 will be subject to a heated environment (typically within an oven) during the baking process. The dunking stick 10 is thus made from any material that is able to withstand being subject to heat sufficient to bake the baked product 30 .
[0036] While certain types of plastic melt when subject to heat, in one example embodiment, the dunking stick 10 is made of a plastic that has a melting point higher than a temperature at which a baked product 30 is baked. The temperature at which a baked product 30 is baked typically ranges between 350 and 450 degrees Fahrenheit.
[0037] Turning now to FIG. 1 a , there is shown a perspective view of the dunking stick 10 inserted into and extending from a baked product 30 (e.g., a cookie or biscuit).
[0038] Turning now to FIG. 1 b , a logo 40 is shown to be placed on the surface of the dunking stick 10 , and may comprise any shape, logo, brand, or picture desired.
[0039] Turning now to FIG. 1 c , there is shown a perspective view of baked products in the exemplary form of cookies or biscuits still in the baking pan 50 with dunking sticks 10 extending from the individual cookies or biscuits 30 by between one and five inches.
[0040] Referring to FIG. 1 d , the baked product assembly (e.g., a cookie or biscuit 30 with dunking stick 10 ) is used to dunk a cookie or biscuit 30 into cup of liquid 60 (e.g., coffee).
[0041] Turning now to FIG. 2 , FIG. 2 a , FIG. 2 b , FIG. 2 c and FIG. 2 d , other embodiments of dunking sticks 10 are shown. These embodiments of dunking sticks 10 have different handle shapes 11 / 12 / 13 / 14 for ergonomic considerations including but not limited to the grip, touch and feel when holding the dunking stick 10 . The ergonomic considerations are influenced by the weight and size of the baked product 30 . In addition to the ergonomic considerations, the shape and size ( 11 / 12 / 13 / 14 ) of the dunking stick can also be influenced by the branding and marketing of the baked product.
[0042] Turning now to FIG. 3 , a further exemplary embodiment of a dunking stick 10 is shown. This embodiment of a dunking stick 10 has a uniform and/or linear edge that extends 20 into the cookie or biscuit.
[0043] Turning now to FIG. 3 a , another exemplary embodiment of a dunking stick 10 is shown. This embodiment of a dunking stick 10 has one or more holes 21 in the portion of the dunking stick (e.g., a blade section) that extends into the cookie or biscuit 30 , to improve the grip inside the cookie or biscuit 30 based on the texture and consistency of the cookie or biscuit 30 .
[0044] Turning now to FIG. 3 b , another embodiment of a dunking stick 10 is shown to demonstrate that the dunking stick is not limited to having a uniform and/or linear edge. This embodiment of a dunking stick 10 has a narrowing 22 in the portion of the dunking stick that extends into the cookie or biscuit 30 , to improve the grip inside the cookie or biscuit 30 based on the texture and consistency of the cookie or biscuit 30 .
[0045] Turning now to FIG. 3 c , yet another embodiment of a dunking stick 10 is shown to demonstrate that the dunking stick is not limited to a uniform and/or linear edge. This exemplary embodiment of a dunking stick 10 has a widening 23 in the portion of the dunking stick that extends into the cookie or biscuit 30 , to improve the grip inside the cookie or biscuit 30 based on the texture and consistency of the cookie or biscuit 30 .
[0046] Turning now to FIG. 3 d , yet another embodiment of a dunking stick 10 is shown. This exemplary embodiment of a dunking stick 10 has a fork-like ending 24 in the portion of the dunking stick 10 that extends into the cookie or biscuit 30 , to improve the grip inside the cookie or biscuit 30 based on the texture and consistency of the cookie or biscuit 30 .
[0047] Turning now to FIG. 3 e , yet another embodiment of a dunking stick 10 is shown. This embodiment of a dunking stick 10 has a narrowing or pin-like 25 in the portion of the dunking stick 10 that extends into the cookie or biscuit 30 , to improve the release of the cookie or biscuit 30 when eaten.
[0048] Turning to FIG. 4 , a flowchart of a method 400 of manufacturing (baking) in accordance with exemplary embodiments.
[0049] First, the dough will be prepared (operation 402 ) in accordance to the recipe for the specific product being baked.
[0050] The dough that is ready for baking is then placed into the baking pan (operation 404 ). The baking pan can vary in shape and size. Some baking pans have separate compartments for each individual cookie or biscuit. Other baking pans may consist of one or more larger compartments that contain more than one individual cookie or biscuit.
[0051] After the dough is placed into the baking pan, a single support member (e.g., dunking stick 10 ) is placed into each individual cookie or biscuit (operation 406 ). When a baking pan is used that combines several individual cookies or biscuits into one, the dunking sticks 10 are placed into the dough so that once each individual cookie or biscuit is cut away, the cookie or biscuit will have a dedicated dunking stick 10 . A baker may manually or automatically define lines into the dough to mark where each individual cookie or biscuit is to assist in correctly placing the dunking sticks into the dough.
[0052] The baking pan with dough and dunking sticks are then placed into an oven (operation 408 ), where it is baked for a time specified in a recipe.
[0053] After the required baking time, the baking pan is removed from the oven (operation 410 ) and left to cool down before removing the baked product assembly, with the dunking stick remaining inserted, from the baking pan (operation 412 ).
[0054] If not baked as individual cookies or biscuits, the baked product assembly is cut into each individual cookie or biscuit, each of which contains a dunking stick (operation 414 ).
[0055] Some baked product assemblies may require a second baking (e.g., drying) of the individual cookies or biscuits, with dunking sticks still remaining inserted (operation 416 ), in order to obtain cookies or biscuits that have a crisp texture.
[0056] The baking product assembly with a dunking stick baked into it is then packaged (operation 418 ) for distribution and consumption by consumers.
[0057] Turning to FIG. 5 , a flowchart of a method 500 of a baked product dunking process in accordance with an exemplary embodiment.
[0058] The person desiring to dunk the baked product in a liquid (e.g., coffee, tea or milk) will take the baked product (operation 502 ) by holding it by a handle section of the dunking stick 10 (operation 504 ) that conveniently extends from the baked product. It should be noted that no separate device or apparatus is required.
[0059] Holding the baked product by the handle section of the dunking stick, the person will lower the baked product into the liquid (operation 506 ) for sufficient time (operation 508 ) to release the flavor in the baked product and to absorb the liquid. The absorption of the liquid by the baked product 30 may add more flavor and softens the texture of the baked product 30 .
[0060] The person then removes the baked product assembly from the liquid, while still holding the baked product assembly by the handle section of the dunking stick 10 , and eat the baked product 30 off the dunking stick 10 (operation 510 ).
[0061] Exemplary embodiments also provide for a method of manufacturing a support member for a baked product. The method includes defining a blade portion of the support member with a non-linear profile to be at least partially embedded within dough to be baked to create the baked product. A handle portion of the support member is defined with an ergonomic profile to be gripped between fingers of a user. Thus, examples of a baked product assembly, support member and associated methods of manufacturing have been described, which seek to provide a convenient manner by which any shape of cookie or biscuit can be dunked or at least partially immersed either into a liquid or simply enjoyed without having to touch the baked product with your finger. | A method of creating a baked product assembly includes providing a body of dough to be baked. A support member is inserted into the body of the dough prior or during baking of the body of dough. The inserting of the support member includes embedding a first section of the support member within the body of dough such that a second section on the support member protrudes from the portion of the dough. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 597,962 filed July 21, 1975 now abandoned.
BACKGROUND OF THE INVENTION
A. Field of the Invention
This invention relates to seals, and more particularly to annular seals for use with well tools which are run in well tubings.
B. Prior Art
Conventionally two types of seals are used on well tools run in a tubing; a V-type or chevron seal and an O-ring seal. Both of these seals have several undesirable characteristics.
The chevron seal requires excessive longitudinal space along the tool and must be physically displaced outwardly into sealing position. The requirements make this type of seal objectionable for small tools where tolerances are close and space for a seal is at a premium. In addition, it is difficult to energize a chevron or V-type seal into a sealing position with a low pressure differential across the seal.
O-rings seals do not have the disadvantages of chevron, V-type seals because an O-ring seal requires little space and will move into a sealing position at a low pressure differential. However, when a tool is being run in a tubing, O-ring seals on the tool tend to wash off. When the tool reaches its final position where it is to be sealed, there is no way of ascertaining whether or not the seal ring is still in position, and the tool can only be set in the hope that there will be an effective seal.
OBJECTS OF THE INVENTION
It is an object of this invention to provide a sealing system which has a sealing unit having the advantages of an O-ring seal of being capable of sealing at low pressure without having the disadvantage of an O-ring seal as far as possible displacement is concerned.
It is a further object of this invention to provide a sealing system which has a sealing unit having the advantages of a chevron seal in that it will not be displaced during travel within a pipe of flowing fluid and also having the advantage of sealing at low pressure differentials and having the further advantage of being smaller in size than the usual chevron seal.
Another object of this invention is to provide a sealing unit having spaced sealing members secured to a support with one sealing member being deformable into a sealing position by fluid flow in one direction and the other member being deformable into a sealing position by flow in the other direction and with each member being deformable at low pressure differentials without interference from the other member.
Additionally, it is an object of this invention to provide a sealing element having a support to prevent the element from being displaced while it is in position on a tool; said element including spaced sealing members which are independently deformable into a sealing position at low pressure differentials.
These and other objects and features of advantage of this invention will be apparent from the drawing, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings wherein the like numerals indicate like parts, and wherein illustrative embodiments of this invention are shown:
FIG. 1 is a view partly in elevation and partly in cross-section showing the sealing system constructed in accordance with the invention mounted upon a well tool which is positioned within a well tubing;
FIG. 2 is a view in section of one form of sealing unit;
FIG. 3 is a view, in section of a second form of sealing unit;
FIG. 4 is a partial enlarged sectional view of the sealing unit of FIG. 3 to more clearly illustrate its cross-sectional shape;
FIG. 5 is a partial enlarged sectional view of the sealing unit of FIG. 4 incorporated into a sealing system with the sealing unit in a position prior to being subjected to the pressure to be sealed;
FIG. 6 is a view similar to FIG. 4 depicting the sealing unit in its sealing position; and
FIG. 7 is a view partly in cross-section and partly in elevation of the sealing unit of FIG. 2 incorporated into a modified form of sealing system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The sealing unit of this invention is particularly adapted for use with a well tool to be run in a well, although it may be used in other environments. As will be explained, the sealing unit is so designed that even though fluids in the well flow past the well tool as it is being run in the well, the sealing element will not be displaced from its position on the tool. When the tool is in final position within the well, the sealing unit then becomes a part of a sealing system to seal the annulus around the well tool.
In the drawings, (FIG. 1) a well W has the usual casing C and tubing string 10 extending therethrough and as is well known, various well operations are performed through the bore of said tubing string 10. For receiving and supporting well tools which perform the operations, a tubing string nipple 12 is connected in the tubing string 10. As an example, one operation may involve the pumping of a well tool 14 through the tubing bore, seating the tool within nipple 12, and thereafter performing the desired work. In this instance, the illustrated well tool 14 is utilized to shift a sleeve 16 which is slidable within the tubing string nipple 12. The sleeve 16 is normally retained in an upper position in the nipple by a shear pin 18 and has an internal shoulder 20 which is adapted to be engaged by the work tool 14. As shown, two spaced apart sealing units 22 are positioned in recesses 24 on the exterior of the well tool 14. The sealing units 22 function in accordance with the sealing system of this invention to seal the annulus between the well tool 14 and the sleeve 16 of the tubing string nipple 12.
One form of sealing unit 26 is shown in FIG. 2 and includes the sealing means or element 28 and a support means 30 which is preferably an annular metallic ring. The ring is mounted within an external groove 24 in the well tool (FIG. 1) to hold the sealing element in position. The sealing means or element 28 has its inner annular surface secured to the outer annular surface of the support ring 30 by any conventional bonding technique. The sealing means may be of any suitable, deformable sealing material.
To block fluid flow in either direction across the sealing unit 26, the sealing means or element 28 has its external portion shaped to form a pair of sealing members 32 and 34 which may be integral with a central connecting portion 36. Forming the sealing means 28 as one component with a pair of sealing members 32 and 34 and a central connecting portion 36 enables the entire sealing means 28 to be secured to the support means 30 in one operation. The concave face 38 provides a space between the sealing faces into which the sealing members may flow when deformed as the tool 14 moves into the sleeve 16. To insure that the central connecting portion 36 does not interfere with the deformation of each sealing member 32 and 34, said connecting portion 36 has its face 38 concave in cross-sectional shape.
The sealing members 32 and 34 each have an sealing face 40 and 42, respectively on its surface opposite the ring support means. Each sealing face, 40 and 42, is shaped to be deformable into a sealing engagement when a pressure differential exists across the sealing unit 26. In their non-deformed and non-sealing configuration, the cross-section of each sealing face 40 and 42 is generally convex in shape and the outer opposite edges 40a and 42a of each sealing face 40 and 42 are aligned with the edge of the annular support means 30. The curved sealing faces 40 and 42, and the respective sealing members 32 and 34 which form them, are spaced a sufficient distance apart by the concave connecting portion 36 so that each sealing member 30 and 32 is deformable.
The operation of each sealing unit 26 will be described along with the operation of the second form since the function of both forms is substantially the same.
A second form of the sealing unit 44 shown in FIG. 3 may also be utilized. Similar to the first form of sealing unit 26, this sealing unit 44 has a support means 46. Sealing means 48 of a suitable deformable sealing material is secured to the outer annular surface of the support means 46. Sealing means 48 also has a pair of sealing members 50 and 52. However, unlike the first form of sealing unit 26 where the outer edges of faces 40 and 42 were aligned with the edges of the support means 28, in this form the outer opposite faces 54a and 56a of the sealing members 48 and 50, respectively, extend beyond or overhang the edges of the support means 46. Also, like the first form of the sealing unit 24, the pair of sealing members 50 and 52 may be connected by, and integral with, a central connecting portion 58 of the same deformable material having a face 60 that is concave in cross-sectional shape to prevent interference with the deformation of the sealing members 50 and 52.
FIGS. 4, 5 and 6 are enlarged cross-sectional partial views of the sealing means or element 48 of this second form to illustrate the positions it assumes in an undeformed condition, as part of a sealing system between two surfaces, and as deformed into sealing position. In FIG. 4 the sealing element 48 is shown in its undeformed or relaxed condition. When the sealing element is used as part of a sealing system to block fluid flow in the annulus between two surfaces 62 and 64 it is disposed between two surfaces as shown in FIG. 5. One of the surfaces has a recess 66 located therein at the site where fluid flow is to be blocked. The cross-section of the recess 66 is designed to contain the major portion of the sealing element 48 with part of each sealing member 50 and 52 protruding beyond surface 64 to provide an interference fit with the opposing surface 62. When the sealing element 48 is initially placed within the recess 66 there may not be an interference fit between the faces 54 and 56 and the side walls 68 and 70 of the recess 66. However, when the sealing members move into a position to contact the opposing surface 62 they are deformed and do engage the side walls 68 and 70 of the recess 66. This deformed position of the sealing element 48 is illustrated in FIG. 5. The opposing surfaces 62 and 64, the recess 66, and the sealing unit with the sealing element 48 now provide a sealing system.
The application of a pressure differential across the sealing system deforms the sealing means 48, as illustrated in FIG. 6, into its sealing position. An arrow indicates the direction from high to low pressure. The fluid pressure deforms the upstream sealing member 52 away from the facing surface 62 and into the spaced region between the two sealing members 50 and 52. The face 54 of the downstream sealing member 52 is deformed into a sealing engagement with the opposing surface 62 and the side wall 68 of the recess 66. Since the sealing member 50 is deformed independently from sealing member 52, the deformation of sealing member 52 into the space between the sealing members does not inhibit the deformation of sealing member 50 into its sealing engagement. After the sealing element 48 is energized the sealing member 52 may again move into contact with surface 62.
In FIG. 7 an enlarged and exaggerated cross-section of the first form of sealing unit 26 is shown. Although other drawings illustrating the deformation of the sealing element 28 of this sealing unit 26 are not shown, it is to be understood that this sealing element 28 behaves quite similar to the second form of the sealing element 48. Thus, like the second form, a part of each sealing member 32 and 34 protrudes beyond surface 72 and will provide an interference fit with any opposing surface. It can be seen that because of the shape of the sealing members 32 and 34 when the sealing element is placed within recess 74 there may be no interference fit between the sealing faces 40 and 42 and the side walls of the recess. However, when a pressure differential is applied across the sealing system including this sealing element, the downstream sealing member does deform into a sealing engagement with the facing surface and the side wall of the recess.
The deformation of the sealing face against the side wall of the recess blocks any fluid that may attempt to seep past the sealing system by seeping between the annular support ring 30 and the bottom of the recess 74. If desired an additional sealing means may be provided to help block fluid flow at that location. The recess 76 and O-ring 78 as shown in FIG. 1 and, shown in dotted form in FIG. 7 to indicate it may be omitted, provide this additional seal means. With the O-ring 78 being covered by and protected by the annular support means 30 of the sealing unit 26, there are no flowing fluids and moving surfaces to wash it out of position.
A suitable deformable material for the sealing means or element may be of a hardness of 60 to 90 on the durometer scale, although other materials may also be used.
If the nipple 12 in which the well tool 14 is to be sealed has a bore diameter of approximately 2 inches, it has been found that by designing the sealing element so that the sealing members 30 and 32 have a thirty thousandths (0.030) of an inch interference fit across the diameter with the opposing surface, or fifteen thousandths (0.015) of an inch on each side, then when the well tool 14 is run in the tubing string 10, the protruding parts of the sealing members do not pinch off.
Although the described forms of the sealing element has it secured to the outer annular surface of the support means and have a central connecting portion connecting and formed integrally with the sealing members, it is to be understood that a sealing element may be provided where the sealing means, while secured to the support means, is not secured to the outer annular surface of the support means and where each sealing member is separate and no connecting seal section 38 is present. The support means is provided to maintain the sealing means in position in the recess. Two sealing members of the sealing means are provided, one of which blocks fluid flow in one direction across the sealing element, the other blocks flow in the other direction. A space is provided between the sealing faces into which the sealing member may flow when deformed. The sealing members are spaced a sufficient distance apart on the support means so that each member is deformable without interference from the other sealing member.
In some systems the seal may be carried internally of a member and engage a mandrel or the like within the member, but such contribution is not normally preferred in a well.
From the foregoing description it can be seen that the objects of this invention have been obtained. An annular sealing unit for use on the exterior of a well tool has been provided. The sealing unit does not require a lot of space. The support means maintains the unit in a recess around the well tool as the tool moves through flowing fluid in the tubing string. Because the sealing means is deformable, the sealing unit will set into sealing engagement at a low pressure differential. In addition, the sealing element may be set into sealing engagement regardless of the direction of the pressure differential across it.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention. | A sealing unit to be used in sealing system to block fluid flow between two spaced surfaces. The unit seats within a recess in one of the surfaces and includes a support to which is secured deformable sealing means having a pair of sealing members. A pressure differential across the unit deforms the sealing members into a sealing position to effectively seal between the surfaces. This abstract is neither intended to define the invention of the application which, of course, is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to wireless communication, and more particularly, to a method and an apparatus for operating based on a power save mode in a wireless local area network (WLAN).
[0003] 2. Related Art
[0004] In IEEE 802.11, a power saving mechanism (or power saving mode) may be used to increase the life of a wireless local area network (WLAN) station (STA). An STA operating based on the power saving mode is capable of operating in an awake state or doze state in order to save power. The awake state is a state in which normal operations of the STA, such as frame transmission or reception or channel scanning, are possible. The doze state is a state in which power consumption is drastically reduced to make it impossible to transmit or receive a frame and to perform channel scanning. The STA operating in the power saving mode is usually in the doze state and switches to the awake state if necessary to reduce power consumption.
[0005] When the STA is operating for a long time in the doze state, power consumption of the STA is reduced. Accordingly, the life of the STA may increase. However, in the doze state, it is impossible to transmit or receive a frame. Thus, the STA may not stay for a long time in the doze state. When the STA has a pending frame in the doze state, the STA may switch to the awake state to transmit the frame to an AP. However, when the STA is in the doze state and the AP has a pending frame to transmit to the STA, the STA may not receive the pending frame from the AP and does not recognize that the AP has the pending frame. Accordingly, the STA may periodically switch to the awake mode to operate in order to acquire information on whether the AP has a pending frame and to receive the pending frame from the AP.
[0006] The AP may acquire information on an awake-mode operation timing of the STA and transmit information on whether the AP has a pending frame according to the awake-mode operation timing of the STA.
[0007] Specifically, the STA in the doze state may periodically switch from the doze state to the awake state to receive a beacon signal in order to receive information on whether there is a frame to receive from the AP. The AP may notify whether there is a frame to transmit to each STA based on a traffic indication map (TIM) included in the beacon frame. The TIM may be used to indicate the presence of a unicast frame to be transmitted to the STA, and a delivery traffic indication map (DTIM) may be used to indicate the presence of a multicast frame/broadcast frame to be transmitted to the STA.
SUMMARY OF THE INVENTION
[0008] The present invention provides a method for operating based on a power save mode in a wireless LAN.
[0009] The present invention also provides an apparatus for operating based on a power save mode in a wireless LAN.
[0010] In an aspect, provided is a method for operating based on a power save mode in a wireless LAN. The method includes: receiving, by an access point (AP), a first trigger frame triggering transmission of first downlink data buffered with respect to a first station (STA) from the first STA; deciding, by the AP, hold-off of the transmission of the first downlink data transmitted as a response to the first trigger frame based on a first priority of the first downlink data buffered with respect to the first STA, a second priority of second downlink data buffered with respect to a second STA, and a switch point to the second STA; and transmitting, by the AP, a hold off configuration frame indicating the hold-off to the first STA, wherein the first priority is lower than the second priority, and the switch point is duplicated with duration for transmitting the buffered first downlink data.
[0011] In another aspect, provided is an AP for operating based on a power save mode in a wireless LAN. The AP includes: a radio frequency (RF) unit implemented to transmit or receive a radio signal; and a processor operatively connected with the RF unit, wherein the processor is implemented to receive a first trigger frame triggering transmission of first downlink data buffered with respect to a first station (STA) from the first STA, decide hold-off of the transmission of the first downlink data transmitted as a response to the first trigger frame based on a first priority of the first downlink data buffered with respect to the first STA, a second priority of second downlink data buffered with respect to a second STA, and a switch point to the second STA, and transmit a hold off configuration frame indicating the hold-off to the first STA, the first priority is lower than the second priority, and the switch point is duplicated with duration for transmitting the buffered first downlink data.
[0012] An AP preferentially transmits downlink data to a high priority QoS STA to reduce a service delay.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a concept view illustrating the structure of a wireless local area network (WLAN).
[0014] FIG. 2 is a conceptual view illustrating a U-APSD procedure in the related art.
[0015] FIG. 3 is a conceptual view illustrating a U-APSD procedure according to an embodiment of the present invention.
[0016] FIG. 4 is a conceptual view illustrating a downlink frame according to an embodiment of the present invention.
[0017] FIG. 5 is a conceptual view illustrating U-APSD according to an embodiment of the present invention.
[0018] FIG. 6 is a conceptual view a method for reducing a service delay in a beacon frame based power save poll procedure according to an embodiment of the present invention.
[0019] FIG. 7 is a conceptual view illustrating a PPDU format transferring a frame according to an embodiment of the present invention.
[0020] FIG. 8 is a block diagram illustrating a wireless apparatus to which an embodiment of the present invention can be applied.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0021] FIG. 1 is a concept view illustrating the structure of a wireless local area network (WLAN).
[0022] An upper part of FIG. 1 shows the structure of the IEEE (institute of electrical and electronic engineers) 802.11 infrastructure network.
[0023] Referring to the upper part of FIG. 1 , the WLAN system may include one or more basic service sets (BSSs, 100 and 105 ). The BSS 100 or 105 is a set of an AP such as AP (access point) 125 and an STA such as STA 1 (station) 100 - 1 that may successfully sync with each other to communicate with each other and is not the concept to indicate a particular area. The BSS 105 may include one AP 130 and one or more STAs 105 - 1 and 105 - 2 connectable to the AP 130 .
[0024] The infrastructure BSS may include at least one STA, APs 125 and 130 providing a distribution service, and a distribution system (DS) 110 connecting multiple APs.
[0025] The distribution system 110 may implement an extended service set (ESS) 140 by connecting a number of BS Ss 100 and 105 . The ESS 140 may be used as a term to denote one network configured of one or more APs 125 and 130 connected via the distribution system 110 . The APs included in one ESS 140 may have the same SSID (service set identification).
[0026] The portal 120 may function as a bridge that performs connection of the WLAN network (IEEE 802.11) with other network (for example, 802.X).
[0027] In the infrastructure network as shown in the upper part of FIG. 1 , a network between the APs 125 and 130 and a network between the APs 125 and 130 and the STAs 100 - 1 , 105 - 1 , and 105 - 2 may be implemented. However, without the APs 125 and 130 , a network may be established between the STAs to perform communication. The network that is established between the STAs without the APs 125 and 130 to perform communication is defined as an ad-hoc network or an independent BSS (basic service set).
[0028] A lower part of FIG. 1 is a concept view illustrating an independent BSS.
[0029] Referring to the lower part of FIG. 1 , the independent BSS (IBSS) is a BSS operating in ad-hoc mode. The IBSS does not include an AP, so that it lacks a centralized management entity. In other words, in the IBSS, the STAs 150 - 1 , 150 - 2 , 150 - 3 , 155 - 4 and 155 - 5 are managed in a distributed manner. In the IBSS, all of the STAs 150 - 1 , 150 - 2 , 150 - 3 , 155 - 4 and 155 - 5 may be mobile STAs, and access to the distribution system is not allowed so that the IBSS forms a self-contained network.
[0030] The STA is some functional medium that includes a medium access control (MAC) following the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standards and that includes a physical layer interface for radio media, and the term “STA” may, in its definition, include both an AP and a non-AP STA (station).
[0031] The STA may be referred to by various terms such as mobile terminal, wireless device, wireless transmit/receive unit (WTRU), user equipment (UE), mobile station (MS), mobile subscriber unit, or simply referred to as a user.
[0032] Hereinafter, in an embodiment of the present invention, data (alternatively, or a frame) which an AP transmits to an STA may be expressed as downlink data (alternatively, a downlink frame) and data (alternatively, a frame) which the STA transmits to the AP may be expressed as a term called uplink data (alternatively, an uplink frame). Further, transmission from the AP to the STA may be expressed as downlink transmission and transmission from the STA to the AP may be expressed as a term called uplink transmission.
[0033] The STA that operates in the power save mode in the wireless LAN in the related art may operate based on an unscheduled automatic power save delivery (U-APSD), scheduled automatic power save delivery (S-APSD), or power save poll technique. When the STA uses the U-APSD and the S-APSD, it may be difficult to support a real time application (for example, voice over internet protocol (VoIP)) in real time.
[0034] FIG. 2 is a conceptual view illustrating a U-APSD procedure in the related art.
[0035] In FIG. 2 , an increase problem of a service delay which may occur when the U-APSD is used is disclosed.
[0036] Hereinafter, AC_VO, AC_VI, AC_BE, and AC_BK are examples for a category for classifying priorities (alternatively, transmission priorities) of data. The priorities of the data may be classified based on categories other than AC_VO, AC_VI, AC_BE, and AC_BK.
[0037] Referring to FIG. 2 , downlink data 210 corresponding to access category_video (AC_VI) to be transmitted to STA 1 , downlink data 215 corresponding to access category_voice (AC_VO) to be transmitted to STA 2 , downlink data 220 corresponding to access category_best effort (AC_BE) to be transmitted to STA 3 , and downlink data 225 corresponding to access category_backgroud (AC_BK) to be transmitted STA 4 may be pended to the AP.
[0038] The downlink data may have a high priority in the order of AC_VO, AC_VI, AC_BE, and AC_BK. That is, when only the priority is considered, the AP needs to first transmit the downlink data corresponding to AC_VO and last transmit the downlink data 225 corresponding to AC_BK.
[0039] However, time intervals (alternatively, listen intervals) for doze states (alternatively, sleep modes) awake states (alternatively, active modes) of the respective STA 1 , STA 2 , STA 3 , and STA 4 may be different from each other or start timings of the respective states (alternatively, listen intervals) may be different from each other even though the time intervals (alternatively, listen intervals) are the same as each other. Therefore, transmission timings of trigger frames of the plurality of respective STAs that request the transmission of the frame pended to the AP may also be different from each other. The trigger frame may be a frame for requesting transmission of the downlink data pended to the AP.
[0040] In FIG. 2 , it is assumed that the STA 3 is switched to the awake state earlier than the STA to transmit a trigger frame 230 to the AP.
[0041] The STA 3 may be switched to the awake state earlier than the STA 2 and the STA 3 may transmit the trigger frame 230 to the AP after being switched to the awake state. The AP may receive the trigger frame 230 from the STA 3 , transmit an ACK frame for the trigger frame 230 , and transmit a downlink frame 240 including the downlink data corresponding to AC_BE pended to the STA 3 . When a value of a moredata field included in the downlink frame 240 is 1, the moredata field value of 1 may indicate that the downlink data additionally pended to the STA 3 remains in the AP. Contrary to this, when the value of the moredata field included in the downlink frame 240 is 0, the moredata field value of 0 may indicate that the downlink data additionally pended to the STA 3 does not remain in the AP.
[0042] The STA 2 may be switched from the doze state to the awake state while the AP transmits the downlink data to the STA 3 . After the STA 2 is switched to the awake state, the STA 2 may not acquire a medium for transmitting the trigger frame but configure a network allocation vector (NAV) due to the downlink frame 240 and the ACK frame 235 transmitted or received between the AP an the STA 2 .
[0043] The STA 2 may acquire the medium and transmit a trigger frame 250 to the AP after communication between the AP and the STA 3 ends. The AP may receive the trigger frame 250 transmitted by the STA 2 , transmit an ACK frame 255 as a response to the trigger frame 250 , and transmit to the STA 2 a downlink frame 260 including the downlink data corresponding to AC_VO pended to the STA 2 .
[0044] That is, in the U-APSD in the related art, a high priority quality of service STA such as the STA 3 is switched to the awake state later (alternatively, awakes later) than a relatively low priority QoS STA such as STA 2 to transmit the trigger frame. The high priority quality of service STA may be an STA that will receive relatively higher priority pended downlink data and the low priority QoS STA may be an STA that will receive relatively lower priority pended downlink data.
[0045] In this case, transmission of the downlink data to the high priority QoS STA may be performed after transmission of the downlink data (for example, buffered units (BUs)) to the low priority QoS STA ends. In this case, the service delay for the high priority QoS STA may increase.
[0046] Hereinafter, in an embodiment of the present invention, a method for reducing the service delay for the high priority QoS STA in the U-APSD is disclosed.
[0047] FIG. 3 is a conceptual view illustrating a U-APSD procedure according to an embodiment of the present invention.
[0048] In FIG. 3 , a method in which the AP holds off (alternatively, holds off) transmission of relatively lower priority buffer (alternatively, pended) data among the pended downlink data and preferentially transmits relatively higher priority buffered data is disclosed.
[0049] In detail, a plurality of downlink data units may be pended (alternatively, buffered) corresponding to different access categories (alternatively, classes or priorities) (hereinafter, referred to as priorities) may be pended to the AP. In detail, when it is assumed that a first priority is a priority relatively higher than a second priority, downlink data having the second priority relatively lower than the first priority and downlink data having the first priority relatively higher than the second priority may be pended to the AP.
[0050] It may be assumed that the downlink data having the first priority pended to the STA 1 and the downlink data having the second priority pended to the STA 2 are pended to the AP. According to the embodiment of the present invention, while the downlink data having the second priority pended to the STA 2 is transmitted to the STA 2 , when transmission of the downlink data having the first priority pended to the STA 1 to the STA 1 is available, the AP may hold off (alternatively, delay) the transmission of the downlink data having the second priority to the STA 2 and perform the transmission of the downlink data having the first priority to the STA 1 .
[0051] The AP may find whether the STA receives the downlink data having the first priority in order to hold off the transmission of the downlink data having the second priority and transmit the downlink data having the first priority. For example, when it is determined that the STA 1 that will receive the downlink data having the first priority is switched to the awake state and the STA 1 is within a serviceable range of the AP while transmitting the downlink data having the second priority to the STA 2 , the AP may stop the transmission of the downlink data to the STA 2 and transmit the downlink data having the first priority to the STA 1 .
[0052] In detail, the AP may perform a U-APSD operation considering the priority of the downlink data of the AP according to the embodiment of the present invention based on information 300 on a listen interval of the STA, information indicating whether the STA that will receive the buffered (alternatively, pended) downlink data, and information indicating the priority of the downlink data pended to the coupled STA.
[0053] The information 300 on the listen interval of the STA may be transmitted to the AP through a coupling request frame transmitted by the STA at the time of coupling the STA. The listen interval may be an inter-state switch interval of the STA that operates in the awake state or the doze state based on a power saving mode. The STA that operates based on the U-APSD maintains the doze state during a predetermined interval and awakes and is switched to the awake state to transmit the trigger frame to the AP. The listen interval may be a time interval between an end time of a current awake state and a start time of a next awake state of the STA. As another expression, the listen interval may be an interval between a maintenance time of the doze state of the STA and a wake-up time of the STA. The AP may decide whether the STA operates in an awake mode based on the listen interval of the STA.
[0054] Information indicating whether the STA that will receive the buffered (alternatively, pended) downlink data receives the buffered (alternatively, pended) downlink data is information indicating whether the STA is positioned within a service range of the AP. For example, the STA is periodically switched from the doze state to the awake state to transmit a keep alive check report frame (alternatively, a keep alive report frame) 310 to the AP. The keep alive report frame 310 may be used to announce whether the STA is present in coverage of the AP. The AP may periodically verify that the STA is positioned in a serviceable region (alternatively, a transmission coverage range) of the AP based on the keep alive report frame 310 transmitted by the STA.
[0055] For example, the AP may decide the listen interval of the STA, information on an STA (serviceable STA) that is positioned in a current serviceable region based on the keep alive check report frame 310 transmitted by the STA, and an STA (awake-state STA) which is in the awake state among the STAs positioned in the serviceable region.
[0056] Information on the priority of the downlink data pended to the coupled STA may be information on a transmission priority of the pended downlink data to be transmitted to the coupled SA. A relationship between the serviceable STA (alternatively, awake-state STA) and the downlink data to be transmitted to the serviceable STA (alternatively, awake-state STA) may be managed based on a mapping table. For example, the mapping table may map the serviceable STA and the information on the priority of the downlink data pended to the serviceable STA. The AP may transmit the downlink data based on the awake-state STA included in the serviceable STA and the priority of the downlink data pended to the awake-state STA.
[0057] For example, when a plurality of awake-state STAs is provided, the AP may decide the awake-state STA mapped with the pended downlink data having a highest priority among the plurality of awake-state STAs as a transmission target STA. When the STA that transmits the current downlink data is not the transmission target STA, the AP may stop (alternatively, delay) the transmissions of the downlink data to the STA and transmit the downlink data to the transmission target STA.
[0058] For example, the AP may announce hold-off of downlink data 320 having the second priority pended to the STA in order to hold off transmission of the downlink data 320 having the second priority to the STA 2 and perform transmission of downlink data 33 having the first priority to the STA 1 .
[0059] The AP may transmit a last downlink frame transmitted the STA 2 , which includes information indicating hold-off of transmission of the downlink frame (downlink data) before holding off the transmission of the downlink frame including the downlink data 320 having the second priority pended to the STA 2 . The last downlink frame transmitted before holding off the transmission of the downlink frame to the STA may be expressed as a term called a hold-off configuration downlink frame.
[0060] The hold-off configuration downlink frame may include a downlink transmission hold-off field (alternatively, a downlink transmission hold off indication) in order to hold off the transmission of the downlink frame. The downlink transmission hold-off field may be included in a control field (for example, a high throughput (HT) control field and a very high throughput (VHT) control field) of an MAC header of the downlink frame or included in a newly defined field.
[0061] For example, when a value of the downlink transmission hold-off field (alternatively, indication) is 1, the downlink transmission hold-off field (alternatively, indication) may indicate hold-off of the transmission of the downlink data. When the value of the downlink transmission hold-off field (alternatively, indication) is 0, the downlink transmission hold-off field may be reserved without being mapped with separate information.
[0062] Further, a hold off configuration downlink frame transmitted by the AP may include information on transmission resume of the transmission of the downlink frame (alternatively, downlink data). For example, the hold off configuration downlink frame may include information on a time of performing the transmission resume of the downlink data.
[0063] The information on a time (a downlink data transmission resuming time) of performing the transmission resuming of the downlink data may be transmitted while being included in a resume downlink transmission time field (alternatively, resume downlink transmission time information).
[0064] The resume downlink transmission time field may be transmitted while being included in a lower field of the control field (for example, the high throughput (HT) control field and the very high throughput (VHT) control field) of the MAC header of the downlink frame or included in the newly defined field. Alternatively, a value corresponding to a transmission opportunity (TXOP) limit included in a QoS control field included in the MAC header may be associated with the downlink data transmission resume time. The resume downlink data transmission time field may include information on duration up to a point of resuming the transmission of the downlink frame to the STA again after transmitting the hold off configuration downlink frame. As another expression, the resume downlink data transmission time field may include information on a configuration interval of the NAV after receiving the hold off configuration downlink frame. As yet another expression, the resume downlink data transmission time field may include information on duration up to a point when the STA is switched the awake state in order to monitor the downlink frame again from a point of receiving the hold off configuration downlink frame. Alternatively, the resume downlink data transmission time field may include information on a point of resuming the transmission of the downlink frame to the STA.
[0065] In detail, the STA 2 wakes up earlier than the STA 1 to transmit trigger frame 1 315 to the AP and thereafter, receive the downlink frame 320 including the downlink data having the second priority. The AP may decide hold-off of the transmission of the downlink data 320 having the second priority based on the point when the STA is switched to the awake state. In this case, the AP may transmit the hold off configuration downlink frame including the downlink transmission hold-off field and the resume downlink transmission time field. In FIG. 3 , it is assumed that the downlink frame first transmitted to the STA 2 after receiving the trigger frame 1 315 from the STA 2 is the hold off configuration downlink frame.
[0066] The STA 2 may receive the downlink transmission hold-off field having the value of 1 included in the hold off downlink frame and configure the NAV based on the resume downlink transmission time field. The STA 2 may be switched to the doze state from the awake state and maintain the doze state during the NAV configuration interval. The STA 2 may be switched to the awake state from the doze state again and monitor the downlink frame transmitted from the AP after the NAV configuration interval configured based on the resume downlink transmission time field.
[0067] The STA 1 may transmit trigger frame 2 325 to the AP and thereafter, receive an ACK frame (not illustrated) and receive the downlink frame including the downlink data 330 having the first priority.
[0068] FIG. 4 is a conceptual view illustrating a downlink frame according to an embodiment of the present invention.
[0069] In FIG. 4 , a downlink frame including a downlink transmission hold-off field 410 and a resume downlink transmission time field 420 is disclosed.
[0070] Referring to FIG. 4 , the MAC header of the downlink frame may include the downlink transmission hold-off field and the resume downlink transmission time field.
[0071] According to the embodiment of the present invention, when the pended downlink data having the relatively high priority may be transmitted, the AP may hold off transmission of the pended downlink data having the relatively low priority, which is currently transmitted. The hold off configuration downlink frame transmitted before holding off the transmission of the pended downlink data having the relatively low priority may include the downlink transmission hold-off field and the resume downlink transmission time field.
[0072] The downlink transmission hold-off field 410 may include information indicating whether to hold off the transmission of the downlink frame.
[0073] The resume downlink transmission time field 420 may include information associated with the resume of the hold-off transmission of the downlink data.
[0074] The resume downlink transmission time field 420 may include information on duration up to a point of resuming the transmission of the downlink frame to the STA again after transmitting the hold off configuration downlink frame. As another expression, the resume downlink transmission time field 420 may include information on a configuration interval of the NAV (alternatively, a doze state maintaining interval) after receiving the hold off configuration downlink frame. As yet another expression, the resume downlink transmission time field 420 may include information on duration up to a point when the STA is switched the awake state in order to monitor the downlink frame again from the point of receiving the hold off configuration downlink frame. Alternatively, the resume downlink transmission time field 420 may include the information on the point of resuming the transmission of the downlink frame to the STA.
[0075] The transmission resume point of the downlink frame may be decided based on a transmissions completion prediction point of the pended downlink data having the relatively high priority when the transmission of the downlink data is held off. Similarly, the point when the STA is switched to the awake state or duration when the STA is operated in the doze state may be decided based on the transmissions completion prediction point of the pended downlink data having the relatively high priority when the transmission of the downlink data is held off.
[0076] FIG. 5 is a conceptual view illustrating U-APSD according to an embodiment of the present invention.
[0077] In FIG. 5 , a method is disclosed, which holds off the pended downlink data having the relatively low priority, which is currently transmitted and transmits the pended downlink data having the relatively low priority when the AP may transmit the pended downlink data having the relatively high priority.
[0078] Referring to FIG. 5 , the downlink data corresponding to the access category_video (AC_VI) to be transmitted to the STA 1 , the downlink data corresponding to the access category_voice (AC_VO) to be transmitted to the STA 2 , the downlink data corresponding to the access category_best effort (AC_BE) to be transmitted to STA 3 , and the downlink data corresponding to the access category_backgroud (AC_BK) to be transmitted to the STA 4 may be pended to the AP.
[0079] The STA 3 may wake up earlier than the STA 2 and the STA 3 may transmit trigger frame 1 500 to the AP. The AP may transmit an ACK frame 510 to the STA 3 as a response to the trigger frame. The AP may transmit the ACK frame 510 and transmit pended downlink data for the STA 3 , which corresponds to AC_BE after a predetermined time (an enhanced distributed channel access (EDCA) delay).
[0080] As described above, the AP may find a switch time of the STA 2 to the awake state based on the listen interval of the STA 2 . Further, the AP may also find even whether the STA is positioned within the service range of the AP based on the information indicating whether the STA that will receive the buffered (alternatively, pended) downlink data receives the buffered (alternatively, pended) downlink data.
[0081] When the priority of the downlink data pended with respect to the STA 2 to be switched to the awake state is higher than the priority of the downlink data pended with respect to the STA 3 , which is currently transmitted, the AP may hold off (alternatively, delay) the transmission of the downlink data to the STA 3 .
[0082] The AP may transmit the hold off configuration downlink frame 520 to the STA 3 . In FIG. 5 , the method is described by assuming that the downlink frame which is first transmitted is the hold off configuration uplink frame 520 . The hold off configuration downlink frame 520 may include the downlink transmission hold-off field and the resume downlink transmission time field.
[0083] For example, the downlink transmission hold-off field included in the hold off configuration downlink frame 520 may indicate the hold-off of the transmission of the downlink data and the resume downlink transmission resume time field may include information on the point of resuming the transmission of the downlink data after transmitting (alternatively, receiving) the hold off configuration downlink frame 520 .
[0084] The STA may receive the hold off configuration downlink frame 520 and be switched to the doze state from the awake state. The STA 3 may configure the NAV and maintain the doze state during the predetermined time interval decided based on the resume downlink transmission time field.
[0085] The STA 3 is switched to the awake state from the doze state after the NAV interval configured based on the resume downlink transmission time field to monitor a downlink frame 550 transmitted to the STA 3 by the AP. Information included in the resume downlink transmission time field may be decided based on the transmission completion prediction time of the downlink data pended with respect to the STA 2 that holds off the transmission of the downlink data pended with respect to the STA 3 .
[0086] The AP may transmit the hold off configuration downlink frame 520 to the STA 3 and the AP may receive trigger frame 2 530 from the STA 2 . The STA 2 may acquire the medium and transmit the trigger frame 2 530 to the AP when the communication between the AP and the STA 3 stops. The AP may receive the trigger frame 2 530 from the STA 2 and transmit an ACK frame 535 as a response to the trigger frame 2 530 . The AP may transmit a downlink frame 540 to the STA 2 after transmitting the ACK frame 535 . When downlink data having a relatively higher priority than the downlink data pended with respect to the STA 2 may not be transmitted, the AP may transmit the downlink data pended with respect to the STA 2 to the STA 2 without stop. The downlink frame 540 transferring the pended downlink data may include the moredata field. When the moredata field of the downlink frame 540 is 1, the moredata field of 1 may indicate that the downlink data yet pended with respect to the STA remains. When the moredata field of the downlink frame 540 is 0, the moredata field of 1 may indicate that the downlink data pended with respect to the STA yet remains.
[0087] The AP may transmit residual downlink data pended with respect to the STA 3 after ending the transmission of the downlink data pended with respect to the STA 2 . The AP may transmit to the STA 3 the downlink frame 540 including the residual downlink data pended with respect to the STA 3 .
[0088] That is, when it is assumed that the priority of first downlink data pended to the STA 3 is lower than the priority of second downlink data pended to the STA 2 , an operating method of the AP based on the power save mode in the wireless LAN may be performed as below.
[0089] The AP may receive a first trigger frame that triggers transmission of the first downlink data pended with respect to the STA 3 from the first STA and decide hold-off of the transmission of the first downlink data transmitted as a response to the first trigger frame based on the priority of the second downlink data pended with respect to the STA 2 and the point when the STA 2 is switched to the awake sate. Further, the AP may transmit a hold off configuration frame indicating the hold-off to the STA 3 . The AP may transmit residual first downlink data after a resume point based on a resume time of the transmission of the pended first downlink data of the resume downlink transmission time field included in the hold off configuration frame. The residual first downlink data may include first downlink data other than the first downlink data transmitted before the hold-off among the pended downlink data.
[0090] In this case, the resume point may be decided based on a transmission completion point of the pended second downlink data and the switch point of the STA 2 to the awake state may be duplicated with duration for transmitting the pended first downlink data.
[0091] According to the embodiment of the present invention, the downlink frame is transmitted by considering the priority of the pended downlink data even in the U-APSD procedure to reduce the service delay for the downlink data having the high priority.
[0092] FIG. 6 is a conceptual view a method for reducing a service delay in a beacon frame based power save poll procedure according to an embodiment of the present invention.
[0093] In FIG. 6 , an action of the STA which is operated in the power saving mode based on a TIM of a beacon frame 600 is disclosed.
[0094] Referring to FIG. 6 , the AP may transmit the beacon frame 600 to the STA 1 , the STA 2 , the STA 3 , and the STA 4 . The beacon frame 600 may include a traffic indication map (TIM) or a delivery traffic indication map (DTIM). The TIM may indicate existence of the downlink data to be transmitted based on unicast pended to the STA. The TIM may indicate existence of the downlink data to be transmitted based on unicast pended to the STA.
[0095] For example, the TIM of the beacon frame 600 may indicate the existence of the downlink data pended with respect to the STA 1 , the STA 2 , the STA 3 , and the STA 4 . When a traffic indication for the STA is set to 1 in the TIM, the traffic indication of 1 may indicate the existence of the downlink data pended to the STA.
[0096] Referring to FIG. 6 , the downlink data corresponding to the access category_video (AC_VI) to be transmitted to the STA 1 , the downlink data corresponding to the access category_voice (AC_VO) to be transmitted to the STA 2 , the downlink data corresponding to the access category_best effort (AC_BE) to be transmitted to STA 3 , and the downlink data corresponding to the access category_backgroud (AC_BK) to be transmitted to the STA 4 may be pended to the AP.
[0097] Each of the STA 1 , the STA 2 , the STA 3 , and the STA 4 may receive the beacon frame 600 and find the existence of the downlink data pended based on the TIM included in the beacon frame 600 . Each of the STA 1 , the STA 2 , the STA 3 , and the STA 4 may receive the beacon frame 600 and access the media based on a contention (for example, EDCA).
[0098] In FIG. 6 , a case in which the STA 2 and the STA 3 are in the awake state is disclosed for easy description. The AP may find the listen interval of each of the STA 1 , the STA 2 , the STA 3 , and the STA 4 . The listen interval of the STA that is operated in the power saving mode based on the TIM may be a receiving interval of the beacon frame 600 . For example, the STA maintains the doze mode and thereafter, is switched to the awake mode from the doze mode during the receiving interval of the beacon frame 600 to receive the beacon frame 600 . When the beacon frame is transmitted at a period of 100 ms, the listen interval may be a time interval of the unit of 100 ms.
[0099] The STA is switched to the awake mode based on the listen interval and receives the beacon frame 600 to determine whether a frame pended for the STA exists in the AP based on the TIM or DTIM included in the beacon frame. For example, when the TIM of the beacon frame indicates the existence of the frame pended for the STA, the STA maintains the awake mode and transmits the trigger frame to trigger the transmission of the pended frame. When the DTIM indicates the existence of the frame pended for the STA, the STA may monitor the frame transmitted to the STA by the AP without transmitting a separate trigger frame.
[0100] Contrary to this, when the TIM or DTIM of the beacon frame 600 does not indicate the existence of the frame pended for the STA, the STA may be switched to the doze mode from the awake mode.
[0101] In FIG. 6 , the operation is described by assuming that the TIM of the beacon frame 600 indicates the existence of the downlink data pended with respect to the STA 1 , the STA 2 , the STA 3 , and the STA 4 .
[0102] When the STA 3 accesses the medium earlier than the STA 2 , the STA 3 may transmit power save (PS)-poll frame 1 610 to the AP through the medium.
[0103] Since the AP finds the listen interval of the STA 2 , the STA 2 may find that the STA 2 is also in the awake mode and the downlink data may be transmitted to the STA 2 . The transmission priority of the downlink data pended with respect to the STA 2 may be higher than the transmission priority of the downlink data pended with respect to the STA 3 . In this case, the downlink frame which the AP transmits after receiving the PS-Poll frame 610 transmitted by the STA 3 may be a hold off configuration downlink frame 620 . That is, the AP may transmit a hold off configuration downlink frame 620 including the downlink transmission hold-off field and the resume downlink transmission time field.
[0104] The STA 3 may receive the hold off configuration downlink frame 620 and is switched to the doze state and the STA 3 may configure the NAV and maintain the doze state during a predetermined time interval based on the resume downlink transmission time field. The STA 3 is switched to the awake mode after the NAV interval configured based on the resume downlink transmission time field to monitor a downlink frame 670 transmitted to the STA 3 by the AP.
[0105] The AP may transmit the hold off configuration downlink frame 620 to the STA 3 and receive PS-Poll frame 2 640 from the STA 2 . The STA 2 may acquire the medium and transmit the PS-Poll frame 2 640 to the AP when the communication between the AP and the STA 3 stops. The AP may receive the PS-poll frame 2 640 from the STA 2 and transmit an ACK frame 650 as a response to the PS-poll frame 2 640 . The AP may transmit a downlink frame 660 to the STA 2 after transmitting the ACK frame 650 . When downlink data having the relatively higher transmission priority than the downlink data pended with respect to the STA 2 may not be transmitted, the AP may transmit the downlink frame 660 to the STA 2 without stopping the transmission of the downlink data pended with respect to the STA 2 .
[0106] In the aforementioned embodiment, it is assumed that the downlink transmission hold-off field and the resume downlink transmission time field are included in the hold off configuration downlink frame, but the downlink transmission hold-off field and the resume downlink transmission time field may be included in hold off configuration ACK frames 510 and 615 .
[0107] FIG. 7 is a conceptual view illustrating a PPDU format transferring a frame according to an embodiment of the present invention.
[0108] In FIG. 7 , the PPDU formation according to the embodiment of the present invention is disclosed. The PPDU may include a PPDU header and a MAC protocol data unit (MPDU) (alternatively, a physical layer service data unit (PSDU)). The frame may correspond to the MPDU. The PPDU header of the PPDU format may be used as a meaning including a PHY header and a PHY preamble of the PPDU.
[0109] The PPDU format illustrated in FIG. 7 may be used for carrying a downlink frame, a trigger frame, a PS-poll frame, and an ACK frame.
[0110] Referring to the upper side of FIG. 7 , the PPDU header of the downlink PPDU may include a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG), a high efficiency-signal A (HE-SIG A), a high efficiency-short training field (HE-STF), a high efficiency-long training field (HE-LTF), and a high efficiency-signal-B (HE-SIG B). From the PHY header to the L-SIG may be classified into a legacy part, a high efficiency (HE) part after the L-SIG.
[0111] An L-STF 700 may include a short training orthogonal frequency division multiplexing (OFDM) symbol. The L-STF 700 may be used for frame detection, automatic gain control (AGC), diversity detection, and coarse frequency/time synchronization.
[0112] An L-LTF 710 may include a long training orthogonal frequency division multiplexing (OFDM) symbol. The L-LTF 710 may be used for fine frequency/time synchronization and channel prediction.
[0113] An L-SIG 720 may be used for transmitting control information. The L-SIG 720 may include information regarding a data rate and a data length.
[0114] An HE-SIG A 730 may include identification information on an STA for indicating a target STA to receive the downlink PPDU. The STA may determine whether the information included in the HE-SIG A 730 receives the PPDU based on the identification information of the target STA. When the STA is indicated based on the HE-SIG A 730 of the downlink PPDU, the STA may perform additional decoding for the downlink PPDU. Further, the HE-SIG A 730 may include information on a resource to receive the downlink data (a frequency resource (alternatively, a sub band) (in orthogonal frequency division multiplexing (OFDMA)-based transmission) or in a multiple input multiple output (MIMO)-based transmission)).
[0115] In the aforementioned embodiment, it is illustrated that the downlink transmission hold off field and the resume downlink transmission time field are included in the frame field, but the downlink transmission hold off field and the resume downlink transmission time field may be included in the HE-SIG A 730 .
[0116] An HE-STF 740 may be used for improving automatic gain control estimation in an MIMO environment or an OFDMA environment.
[0117] An HE-LTF 750 may be used for estimating a channel in the MIMO environment or the OFDMA environment.
[0118] An HE-SIG B 760 may include information on a length modulation and coding scheme (MCS) of the physical layer service data unit (PSDU) for each STA, a tail bit, and the like.
[0119] A size of the inverse fast Fourier transform (IFFT) applied to the HE-STF 740 and the field after the HE-STF 740 , and a size of the IFFT applied to the field before the HE-STF 740 may be different from each other. For example, a size of the IFFT applied to the HE-STF 740 and the field after the HE-STF 740 may be four times larger than the size of the IFFT applied to the field before the HE-STF 740 . When the STA receives the downlink frame, the STA decodes the HE-SIG A 730 in the downlink frame and may determine whether to decode the field after the HE-SIG A 730 based on the identification information of the target STA included in the HE-SIG A 730 . In this case, when the identification information of the target STA included in the HE-SIG A 730 indicates an identifier of the STA, the STA may perform decoding based on the FFT size changed from the HE-STF 740 and the field after the HE-STF 740 . On the contrary, when the identification information of the target STA included in the HE-SIG A 730 does not indicate the identifier of the STA, the STA may stop the decoding and set a network allocation vector (NAV). A cyclic prefix (CP) of the HE-STF 740 may have a larger size than the CP of another field and the during the CP period, the STA may perform the decoding for the downlink PPDU by changing the FFT size.
[0120] An order of the field configuring the format of the PPDU illustrated in the upper side of FIG. 7 may be changed. For example, as illustrated in the stop of FIG. 7 , a HE-SIG B 715 of the HE part may be positioned immediately after the HE-SIG A 705 . The STA decodes up to the HE-SIG A 705 and the HE-SIG B 715 and receives required control information to set the NAV. Similarly, the size of the IFFT applied to the HE-STF 725 and the field after the HE-STF 725 may be the same as the size of the IFFT applied to the field before the HE-STF 1725 .
[0121] The STA may receive the HE-SIG A 705 and the HE-SIG B 715 . When the reception of the downlink PPDU is indicated by the identifier of the target STA of the HE-SIG A 705 , the STA may perform the decoding for the downlink PPDU by changing the FFT size from the HE-STF 725 . On the contrary, when the STA receives the HE-SIG A 705 and the reception of the downlink PPDU based on the HE-SIG A 705 is not indicated, the NAV may be set.
[0122] Referring to the bottom of FIG. 7 , the downlink PPDU formation of downlink (DL) multi-user (MU) transmission is illustrated. The downlink PPDU may be transmitted to the STA through a different downlink transmission resource (a frequency resource or a spatial stream) based on the OFDMA. That is, the downlink data may be transmitted to a plurality of STAs through a plurality of sub bands based on the downlink PPDU format for the DL MU transmission. In the aforementioned embodiment, it is assumed that the AP transmits a downlink frame to one STA. However, according to another embodiment of the present invention, even in the case of the U-APSD, the downlink data may be transmitted to the plurality of STAs in an awake state in the downlink PPDU format for the DL MU transmission.
[0123] On the downlink PPDU, a previous field of the HE-SIG B 745 may be transmitted from a different downlink transmission resource in a duplicated form. A HE-SIG B 745 may be transmitted in an encoded form on the entire transmission resource. A field after the HE-SIG B 745 may include individual information for the plurality of STAs receiving the downlink PPDU.
[0124] When the field included in the downlink PPDU is transmitted through the downlink transmission resource, the CRC for each field may be included in the downlink PPDU. On the contrary, when a specific field included in the downlink PPDU is encoded on the entire downlink transmission resource and transmitted, the CRC for each field may not be included in the downlink PPDU. Accordingly, the overhead for the CRC may be reduced. That is, the downlink PPDU format for the DL MU transmission according to the embodiment of the present invention uses the HE-SIG B 745 in the encoded form on the entire transmission resource to reduce the CRC overhead of the downlink frame.
[0125] Like the downlink PPDU format for the DL MU transmission, the HE-STF 755 and the field after the HE-STF 755 may be encoded based on the different IFFT size from the field before the HE-STF 755 . Accordingly, when the STA receives the HE-SIG A 735 and the HE-SIG B 745 and indicates the reception of the downlink PPDU based on the HE-SIG A 735 , the STA may perform the decoding for the downlink PPDU by changing the FFT size from the HE-STF 755 .
[0126] FIG. 8 is a block diagram illustrating a wireless apparatus to which an embodiment of the present invention can be applied.
[0127] Referring to FIG. 8 , the wireless apparatus 800 as an STA capable of implementing the aforementioned embodiment may be an AP 800 or a non-AP station (alternatively, STA) 850 .
[0128] The AP 800 may include a processor 810 , a memory 820 , and a radio frequency (RF) unit 830 .
[0129] The RF unit 830 is connected with the processor 810 to transmit and/or receive a radio signal.
[0130] The processor 810 may implement a function, a process, and/or a method which are proposed in the present invention. For example, the processor 810 may be implemented to perform an operation of the wireless apparatus according to the embodiment of the present invention. The processor may perform the operation of the wireless apparatus disclosed in the embodiment of FIGS. 2 to 7 .
[0131] For example, the processor 810 may be implemented to receive the first trigger frame triggering the transmission of the first downlink data buffered with respect to the first STA from the first STA, decide hold-off of the transmission of the first downlink data transmitted as a response to the first trigger frame based on a first priority of the first downlink data buffered with respect to the first STA, a second priority of the second downlink data buffered with respect to the second STA, and the switch point of the second STA to the awake state, and transmit the hold off configuration frame to the first STA. The first priority may be lower than the second priority and the switch point may be duplicated with duration for transmitting the buffered first downlink data.
[0132] The first priority may be decided based on first access category of the buffered first downlink data, the second priority may be decided based on second access category of the buffered second downlink data, and the first access category and the second access category may be one of access category (AC)_background (BK), AC_best effort (BE), AC_video (VI), and AC_voice (VO).
[0133] The STA 850 may include a processor 860 , a memory 870 , and a radio frequency (RF) unit 880 .
[0134] The RF unit 880 is connected with the processor 860 to transmit and/or receive the radio signal.
[0135] The processor 860 implements a function, a process, and/or a method which are proposed in the present invention. For example, the processor 820 may be implemented to perform the operation of the wireless apparatus according to the embodiment of the present invention. The processor may perform the operation of the wireless apparatus disclosed in the embodiment of FIGS. 2 to 7 .
[0136] For example, the processor 860 may configure the NAV when transmitting the trigger frame and receives the hold off configuration frame. Further, the processor 860 is switched to the awake mode based on a resume point of transmitting the pended first downlink data including the resume downlink transmission time field included in the hold off configuration frame to monitor the downlink frame transmitted from the AP.
[0137] The processors 810 and 860 may include an application-specific integrated circuit (ASIC), other chipset, a logic circuit, a data processing device, and/or a converter that converts a baseband signal and the radio signal to each other. The memories 820 and 870 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and/or other storage devices. The RF units 830 and 880 may include one or more antennas that transmit and/or receive the radio signal.
[0138] When the embodiment is implemented by software, the aforementioned technique may be implemented by a module (process, function, and the like) performing the aforementioned function. The module may be stored in the memories 820 and 870 and executed by the processors 810 and 860 . The memories 820 and 870 may be positioned inside or outside the processors 810 and 860 and connected with the processors 810 and 860 through various well-known means. | Disclosed are a method and an apparatus for operating based on a power save mode in a wireless LAN. The method for operating based on the power save mode in a wireless LAN may comprise the steps of: an AP receiving, from a first STA, a first trigger frame for triggering the transmission of first downlink data which has been buffered for the first STA; the AP determining a temporary halt of the transmission the first downlink data, which is transmitted as a response to the first trigger frame, based on a first priority rank of the first downlink data which has been buffered for the first STA, a second priority rank of second downlink data which has been buffered for a second STA, and a point when the second STA is switched to an awake state; and the AP transmitting, to the first STA, a temporary halt setting frame for indicating the temporary halt. | 8 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an arrangement whereby advertising meters are located at statistically selected sites in order to meter access to, and use of, advertising communicated to the sites over a communication medium such as the Internet.
BACKGROUND OF THE INVENTION
The Internet has proven to be an efficient and popular mechanism for the dissemination of information from content providers to content recipients. Content providers in many cases are organizations, such as businesses, governmental agencies, educational institutions, and the like, who operate Web sites where such organizations provide information that can be downloaded by content recipients. The content recipients are often consumers who use computers usually located in their dwellings to access the content provided by content providers. However, content recipients may also be other businesses, governmental agencies, educational institutions, and the like. In many cases, a content provider is also a content recipient.
The information provided by content providers to content recipients often includes advertisements in which organizations advertise their goods and/or services. This information is typically provided directly by a Web site to content recipients. Additional information concerning such advertisements is frequently provided at another Web site and is accessed by way of click-through URLS.
The operators of Web sites offering advertisements to content recipients, as well as those who create and place advertisements as offerings by Web sites, have an interest in the success of such advertisements. Success is typically measured by the amount of interest that advertisements generate. While exposure to an advertisement is typically determined, in terms of the Internet, by the number of hits on particular advertising offerings, interest is determined by clicks on click-throughs. Web site owners, and those who create and place advertisements, may then draw market relevant conclusions from the amount of interest exhibited in their advertisements.
Several arrangements have been proposed in order to measure this exposure and/or interest. For example, it is known for a Web site to itself measure the exposure in the content which it offers by determining the number of hits on its content offerings. However, such a measurement provides little information about interest in the advertisements and other information accessible through the click-throughs in the its content. Moreover, this exposure is localized in that its measurement provides little information about exposure to, and/or interest in, content offered by other Web sites, such as competitive Web sites.
Therefore, it has also been proposed to install software meters on the computers of panelists so that the interest of the panelists can be measured and extrapolated over the population as a whole, in much the same way that TV ratings are generated. According to this proposal, the software meters track operating system messages in order to detect communications of interest. These software meters are arranged to log the titles of windows which are displayed to a computer user on the video display unit of a computer because Internet content, as well as application software interfaces, are provided to the user in a window format. However, logging titles of windows is not particularly useful because such titles can be very generic. For example, one such title which is popular with many content providers is simply “Home Page.” This title provides little indication of the information provided to the content recipient.
Tagging of Internet content has been broadly suggested in the context of requiring widespread industry cooperation. However, it is unlikely that such widespread industry cooperation is attainable. Also, such broadly suggested tagging has not been particularly helpful because of the problems that could arise from indiscriminate tagging. For example, inserting a tag in a field or in a sub-object of content requires a decoder which is able to interpret the code that contains the tag. This requirement means that the decoder resident on a panelist's computer must be altered in a manner to detect the tag. Such an alteration is intrusive and many content recipients may, therefore, refuse to permit their equipment to be modified in such an intrusive way.
The present invention is directed to an arrangement for tracking advertisements which solves one or more of the problems noted above.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, a computer readable storage medium has program code stored thereon. The program code, when executed by a computer, performs the following tasks: a) detecting a tag in an advertising banner contained in a message communicated to the computer over an external communication link; b) logging the tag; and c) communicating the tag to a remote facility.
In accordance with another aspect of the present invention, a system comprises a plurality of meters and a remote central facility. Each meter operates on a computer at a statistically selected site, and each meter (i) detects a tag from click-through URLs contained in messages electronically communicated to the computer from remote content suppliers over a communication link, and (ii) communicates the tag to the remote central facility.
In accordance with yet another aspect of the present invention, a storage medium has program code stored thereon. The program code, when executed by a data processor, performs the following tasks: a) detecting a tag contained in a click-through URL of an Internet message communicated to the data processor over an external communication link; and b) storing the tag in a log.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will become more apparent from a detailed consideration of the invention when taken in conjunction with the drawings in which:
FIG. 1 illustrates an advertising metering system that is in accordance with the present invention and that includes a plurality of advertising meters each of which is resident on a computer at a corresponding statistically selected site; and,
FIG. 2 illustrates an exemplary embodiment of an advertising meter which may be used for the advertising meters shown in FIG. 1 .
DETAILED DESCRIPTION
An advertisement metering system 10 is shown in FIG. 1 . The advertisement metering system 10 includes a plurality of meters 12 , where each meter 12 is installed on a corresponding computer 14 at a corresponding statistically selected site 16 . The number and location of these statistical sampling sites 16 depend upon statistical sampling methods. However, a sufficient number of statistically selected sites 16 should be selected in order to provide data which is representative of the population segments relevant to the advertisements being metered.
Each of the computers 14 , as shown in FIG. 1, is connected to a network 18 which may be, for example, the Internet. As is known, the Internet is typically accessed through the public telephone network. However, the network 18 may involve other arrangements such as local area networks and other networks through which advertisements are electronically disseminated.
Advertisements are typically offered by content providers who operate Web sites, such as Web sites 20 shown in FIG. 1 . Frequently, an advertisement offered by one Web site 20 has an associated click-through URL. This click-through URL, when clicked, accesses content provided by another Web site 20 . Accordingly, the Web sites 20 are connected to the network 18 , either directly or through an Internet Service Provider 22 , and are arranged to provide content, usually through home pages, to the content recipients among which are the users of the computers 14 at the statistically selected sites 16 .
The meters 12 may be in the form of software routines to be installed on the computers 14 at the statistically selected sites 16 . Alternatively, the meters 12 may be software and/or hardware for attachment to the computers 14 at the statistically selected sites 16 . The meters 12 meter access by the users of the computers 14 to the advertisements which are provided by the content providers operating the Web sites 20 . The meters 12 may be arranged to meter the advertisements provided by the Web sites 20 by detecting tags (such as codes) embedded into click-through URLs, as discussed below.
The meters 12 may also be used to collect demographic information about the users of the computers 14 who access advertisements provided at the Web sites 20 . For example, the meters 12 may be arranged to require the users to actively identify themselves at log on and/or whenever the users access the advertisements provided at the Web sites 20 . Alternatively, the meters 12 may be arranged to passively identify the users, at log on and/or whenever the users access advertisements, by detecting keystroke differences between users, by employing face and/or body recognition technology, and/or the like.
The metered advertisement and demographic data collected by the meters 12 may be periodically tranferred to a central facility 24 , where the information may be extrapolated over relevant populations and assembled into reports for use by interested customers of the central facility 24 . This data may be manually transferred, such as by mailing diskettes to the central facility 24 , or this data may be transferred electronically to the central facility 24 , such as through the Internet.
Web pages provided by the Web sites 20 typically include several parts. These parts generally include text, links, images, and other types of media content. The core part of any such Web page is its HTML which describes the layout of the various parts of the page on the video displays of the computers 14 . The HTML contains, for example, the text which is to appear on the page, references to images that should be included on the page which is displayed on the video displays of the computers 14 , and any links associated with different parts of a page.
As an example, if a content recipient desires to search for the word “car” through use of a particular service provider, the content recipient may transmit, by use of the content recipients computer 14 , a message over the Internet containing the following URL:
http://search.Server.com/bin/search?p=car
where the name of the actual service provider has been generalized to the word “Server” in the above URL. This exemplary request could return the following exemplary page, which is designated herein as example (1):
(1)
<html>
<head><title>Server! Search Results</title></head>
<body>
.
.
.
<center> <p><a
href=“http://www.Server.com/M=10017.YS20.1.1/D=
Server/K=car/A=31270/?http://www.AdProvider.com/
awi-bin/in.awi?id=1045”><img width=468 height=60
src=“http://images.Server.com/adv/Adprovider/
banner11.gif” alt=“[AdProvider]” border=0></a><p>
</center>
.
.
.
<CENTER>FONT SIZE=“+1”><B>Server! Category Matches
&nbsp; <FONT SIZE=“−1”>(1&nbsp;−&nbsp;20&nbsp;
of&nbsp;79)</FONT></B></FONT></CENTER>
<p><A HREF=“http://www.Server.com/Business_and_
Economy/Companies/Automotive/“>Business and
Economy: Companies: Automotive</A>
<p><A HREF=“http://www.Server.com/Recreation
/Automotive/”>Recreation: Automotive</A>
<p><A HREF=“http://www.Server.com/Business_and_
Economy/Companies/Automotive/Manufacturers/
”>Business and Economy: Companies: Automotive:
Manufacturers</A>
.
.
.
<p><A HREF=“http://www.Server.com/Business_and_
Economy/Companies/Automotive/Rentals/Discount_Car_
And_Truck_Rentals_Ltd_/”>Business and Economy:
Companies: Automotive: Rentals: Discount
<b>Car</b> And Truck Rentals Ltd.</A>
<p>
<center> <p><a
href=“http://www.Server.com/M=10017.YS20.1.1/D=
Server/K=car/A=31270/?http://www.AdProvider.com/
awi-bin/in.awi?id=1045”><img width=468 height=60
src=“http://images.Server.com/adv/Adprovider/
banner11.gif” alt=“[Adprovider]” border=0></a><p>
</center>
.
.
.
<hr><center><small><em>Copyright &copy; 1994-98
Server! Inc.</em> − <a
href=“http://www.Server.com/docs/info/”>Company
Information</a> − <a
href=“http://www.Server.com/docs/info/help.html”
>Help</a></small></center></form>
</body>
</html>
where the name of the service provider providing the requested information has been generalized to the word “Server” and where the name of an ad provider providing an advertisement has been generalized to the word “AdProvider” in example (1).
It should be noted that the above HTML code contains (i) the actual text which is to appear on the video display of the requesting user's computer 14 , (ii) references to the images that should appear, and (iii) the formatting and actual links associated with each element of the content. A browser, after receiving this HTML code from the service provider, constructs the page for the content recipient and then downloads the referenced images to complete the full page. Therefore, there are often multiple transfers of files, generally one text file for each HTML and several image files, in order to build a single page. As can be seen, the basic syntax that is used to include a linked image in a Web page is generally the following, which is designated herein as example (2):
<a href=“http://www.destination.com/thepagetogoto.html”><img
src=“http://www.images.com/theimagefile.gif”></a> (2)
This type of link is especially important for advertising. In the page shown as example (1) above, two advertising banners (shown in bold) are-included with variations of the syntax shown in example (2).
The vast majority of advertising on the Internet takes the form shown above in connection with example (1) where a GIF advertising banner is added to a Web page with links to other Web sites, i.e. Web sites providing other information such as more information about the displayed page or other advertisements. Although there are many exceptions to the use of GIF advertising banners, with many advertisers choosing to use one or more JPEG images or Java applets (or other media) as advertisements, it is a fundamental consequence of the design of Web technologies that there are two items that must be specified by an advertiser who wants to advertise on a Web site. These items are (i) the advertising banner (typically in the form of a GIF file) and (ii) the click-through location or link location where the user will be transferred if the user clicks on the advertisement.
In example (1) above, AdProvider (i.e., the advertising Web site) provided an image file called banner 11 .gif to the service provider. The image file was placed in the /adv/AdProvider sub-directory of the images.Server.com machine. AdProvider also provided to the service provider a click-through location according to the following syntax, which is designated herein as example (3):
http://www.AdProvider.com/awi-bin/in.awi?id=1045 (3)
The service provider chose to modify the click-through location for its own purposes. Thus, instead of using the syntax of example (3), the service provider chose to use instead the following syntax, which is designated herein as example (4):
http://www.Server.com/M=10017.YS20.1.1/D=Server/K=car/A=31270/?http://www.AdProvider.com/awi-bin/in.awi?id=1045 (4)
The URL of example (4) is called a click-through URL, and when used for an advertising banner, is typically provided in an HREF link. A click-through URL is sometimes referred to as a pass-through URL. A redirect URL is a type of click-through URL. For convenience, all such URLs are referred to herein as click-through URLs. When a user is transferred to the page identified by this click-through URL, the user is automatically forwarded to the original AdProvider URL. The service provider merely adds its own prefix to all redirect locations so that the service provider can track the click-through performance of any advertising banner. That is, if a user has clicked on a banner without this redirect feature, the service provider might never have known about it. The URL that the AdProvider provided actually becomes a parameter handed to the redirect script.
Accordingly, by modifying the basic syntax of example (2) to the following syntax, which is designated herein as example (5):
<a href=“http://www.destination.com/thepagetogo to.html?Tag”><img
src=“http://www.images.com/theimagefile.gif”></a> (5)
where Tag is an identifying label, all advertising banner placements can be easily tagged. It is a simple matter for the advertiser, when giving the click-through URL to the Web site, to append the tag. So, in the service provider example above, AdProvider would specify a URL according to the following, which is designated herein as example (6):
http://www.AdProvider.com/awi-bin/in.awi?id=1045+Tag (6)
and Server may re-encode this URL as follows, which is designated herein as example (7):
http://www.Server.com/M=10017.YS20.1.1/D=Server/K=car/A=31270/?http://www.AdProvider.com/awi-bin/in.awi?id=1045+Tag (7)
The identifying label Tag that AdProvider uses for each of its placements can be selected, issued, and controlled by the central facility 24 . Each advertisement should have associated therewith a unique Tag. As a customer of the central facility 24 , AdProvider can be asked to add the designated tag (or a series of tags) to any and all advertisements it wants the operator of the central facility 24 to include in its reports. The tag can then be easily recorded by the meters 12 operating on the computers 14 at the statistically selected sites 16 when the users of the computers 14 at these sites receive and/or view a banner which is provided with this type of tag.
There are basically two types of URLs, i.e., static URLs and dynamic URLS, and either may be used as click-through URLs. Static URLs are generally provided in accordance with the following syntax, which is designated herein as example (8):
http://www.destination.com/somepath/atextpage.html
http://www.destination.com/animagefile.gif (8)
Dynamic URLs are generally provided in accordance with the following syntax, which is designated herein as example (9):
http://www.destination.com/cgi-bin/createpage.cgi
http://www.destination.com/cgi-bin/runscript?param1=50+param2=60
http://www.destination.com/scripts/databaselookup?row=5+column=4+tablename=Addresses (9)
While static URLs cause return of just the contents of a file on a Web site, dynamic URL's cause the Web site to execute code which actually creates a Web page. In the case of a dynamic URL, adding a parameter called Tag has no effect on the execution of the program. Any program would simply ignore this parameter and run the same way whether the parameter is set or not. Accordingly, modifying the dynamic URLs of example (9) according to the following syntax, which is designated herein as example (10):
http://www.destination.com/cgi-bin/createpage.cgi?Tag
http://www.destination.com/cgi-bin/runscript?param1=50+param2=60+Tag
http://www.destination.com/scripts/databaselookup?row=5+column=4+tablename=Addresses+Tag (10)
has no effect.
Furthermore, most Web server software packages currently being used (certainly the Web server software packages used by many, if not all, of the most popular Web servers) ignore this parameter. Accordingly, the following syntax, which is designated herein as example (11):
http://www.destination.com/some/other/path/astatic page.html (11)
is treated the same as the following syntax:
http://www.destination.com/some/other/path/astatic page.html?Tag
Each of the meters 12 can be implemented in accordance with a software routine 100 that is illustrated in FIG. 2 . When a message containing a click-through URL is received by the computer 14 executing the software routine 100 , as indicated by a block 102 , the software routine 100 determines at a block 104 whether the received click-through URL contains a tag. If a tag is not found in a click-through URL, program flow returns to the block 102 to wait for the next message containing a click-through URL. However, if a tag is found, the software routine 100 logs the tag at a block 106 by storing the tag in a log file, which may also store other relevant information such as demographic information.
The software routine 100 at a block 108 then determines whether it is time to communicate the log file to the central facility 24 . This timing may be determined by the user of the computer 14 , but is preferably determined by the central facility 24 that provides the software routine 100 for use on the computers 14 . For example, the software routine 100 may be arranged to communicate the log file to the central facility 24 immediately upon detection of the tag. In this case, the log file transmitted to the central facility 24 is a log file containing only one tag and any other relevant information. This timing may be referred to as echoing because the software routine 100 essentially echos the tag provided from one of the Web sites 20 to the central facility 24 .
Alternatively, the software routine 100 may be arranged to communicate the log file of tags after a predetermined number of passes through the software routine 100 . As another alternative, the software routine 100 may be arranged to transmit the log file during a time when 20 Internet traffic is low and the user's computer 14 is on. As still other alternatives, the software routine 100 may be arranged to remind the user to transmit the log file at power down or power up of the user's computer 14 or at any time therebetween, or the software routine 100 may be arranged to transmit the log file when the log file contains a predetermined amount of information. Yet other alternatives are possible.
In any of the alternatives described above, the software routine 100 may be provided with the capability of constructing an Internet message containing (i) the URL of the central facility 24 , (ii) the log file of accumulated tags, and (iii) other relevant information.
If it is time for the software routine 100 to communicate the log file to the central facility 24 , the software routine 100 at a block 110 transmits the log file to the central facility 24 . After the software routine 100 at the block 110 transmits the log file to the central facility 24 , or if it is not time to communicate the tags to the central facility 24 , program flow returns to the block 102 .
Accordingly, with the present invention, advertising banners can be tagged and, therefore, exposures to these advertising banners can be counted and analyzed. It is relatively easy for a customer of the central facility 24 to add this type of tag to a banner placement. The tags can be easily scanned by the meters 12 . Both viewings and click-throughs can be easily recorded by the meters 12 and analyzed by the central facility 24 . Tagging is basically the same whether the images are GIF images or JPEG images. A tag as described above has no impact on either the content recipients or the content providers. That is, by appending tags to the click-through URL's in advertising banners, the tags have no impact on the performance or behavior of either the customer of the central facility 24 or the service provider or other Web site in the workings of the Internet.
Certain modifications of the present invention have been discussed above. Other modifications will occur to those practicing in the art of the present invention. For example, although example (1) and the accompanying discussion relate to a service provider and an advertiser, it should be understood that any combination of Web sites can provide pages with click-through URLs.
Accordingly, the description of the present invention is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which are within the scope of the appended claims is reserved. | Each of a plurality of advertising meters operates on a computer at a corresponding statistically selected site. Each advertising meter is arranged to detect tags from click-through URLs in advertising banners contained in messages communicated to the computer from remote content suppliers over a communication link. Each advertising meter is also arranged to communicate the tags to a remote central facility for use in assembling reports. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
Application by Emilio R. Marroquin, Ser. No. 833,539, filed Sept. 15, 1977 even date herewith, for "IMPROVED HEADING METHOD FOR FORMING AN UNDERCUT FASTENER DRIVING SLOT", and assigned to the assignee of the present invention.
BACKGROUND OF THE INVENTION
The history of the development of the prior art as it relates to a high torque fastener driving system is treated in detail in my U.S. Pat. No. 4,033,003 granted July 5, 1977. Whereas U.S. Pat. No. 3,388,411, which issued to Rudolph M. Vaughn, teaches the forming of an arcuate and undercut fastener slot having diverging sidewalls using a method requiring three separate heading blows, the Marroquin method taught by U.S. Pat. No. 4,033,003 requires two separate heading blows. This Marroquin Method One uses a hammer that develops a slot where the lateral bulges of the diverging sidewalls of the slot are continuous and uninterrupted along the entire undercut length of the slot. Although the slot so formed is generally acceptable, the hammer used in the first step of the Marroquin Method One does not develop an undercut fastener driving slot that conforms geometrically and visually to the RECESS-HI-TORQUE of MILITARY STANDARD MS 33750. Similarly, the hammer used in the Bergere method taught by U.S. Pat. No. 3,354,481 granted Nov. 28, 1967 does not develop a bowtie or "butterfly" slot that conforms exactly with the requirements of MS 33750.
OBJECTS OF THE INVENTION
Accordingly, it is an object of the invention to provide a new and improved hammer for forming an undercut fastener driving slot by heading.
It is an object of the invention to provide a first hammer for use in a two-step heading method for forming a fastener driving slot having an undercut and diverging sidewall configuration with each sidewall having a noncontinuous sphericity.
SUMMARY OF THE INVENTION
Briefly, in accordance with the invention, an improved hammer for forming an undercut fastener driving slot in the head of a fastener is provided comprising planar means to form a primary surface of the fastener, convex plateau means to form an undercut and diverging slot recessed below the primary surface with each slot sidewall having a noncontinuous sphericity developed by planar triangular means on the convex plateau means, convex partial sphere means to form a speed dimple on either side of the slot, and concave spherical-triangle wedge means to form tandem pairs of spaced-apart bulges of fastener material.
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which may be regarded as the invention, the organization and method of operation, together with further objects, features, and the attending advantages thereof, may best be understood when the following description is read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a plan view of the improved hammer of the present invention.
FIG. 2 is a sectional view, partly broken away, of the hammer of FIG. 1 along the line 2--2.
FIG. 3 is a sectional view, partly broken away, of the hammer of FIG. 1 along the line 3--3.
FIG. 4 is a plan view of the head of a fastener formed in part by the hammer of the present invention.
FIG. 5 is a sectional view of the fastener head of FIG. 4 along the line 5--5 which includes a portion of the fastener body.
DESCRIPTION OF THE INVENTION
The improved hammer 12 of the present invention as shown by FIGS. 1 through 3, and in particular by FIG. 1, has a primary surface 14 that is preferably planar and which establishes a reference bench mark for the positive and negative elevations of the several hammer tool surfaces described hereinafter.
One tool surface means on the hammer body 16 is a convex plateau 18 that extends both longitudinally between spaced-apart lines of origin 20 and 22, and to a maximum positive elevation above the primary surface 14 at an intermediate region of reduced lateral dimension 24. The lines of origin 20 and 22 are at the reference bench mark or zero elevation of the primary surface 14, where the plateau 18 has its regions of maximum lateral dimension 26 and 28, respectively. That is, the plateau 18 flares to a greater transverse dimension at each of the regions 26 and 28 relative to the smaller transverse dimension at the intermediate region 24.
A second tool surface means on the hammer body 16 are convex partial spheres 30 and 32 that extend to a positive elevation above the primary surface 14 but at an elevation that is less than the maximum positive elevation of the intermediate region 24. Convex partial sphere 30 develops a merger line 34 at the zero elevation of the primary surface 14, while convex partial sphere 32 develops a similar merger line 36. The convex partial spheres 30 and 32 are positioned on opposite sides of and spaced-apart by the convex plateau 18 at the intermediate region 24 as shown by FIGS. 1 and 3. It is preferred that each of the merger lines 34 and 36 is relatively short so that the geometry of each more nearly reflects a tangential merger point.
A third tool surface means on the hammer body 16 are concave, wedge-like depressions having a generally spherical triangle geometry. These concave wedges 40, 42, 44, and 46 extend from a zero elevation at the lines of origin 20 and 22 to a negative elevation below the primary surface 14 that reaches a maximum depth adjoining the convex partial spheres 30 and 32 where each sphere extends below the primary surface; these junction lines between the wedges and the spheres are shown by FIG. 1 and identified as 48, 50, 52, and 54, respectively. Concave wedges 40 and 42 as a pair are spaced-apart by the convex plateau 18 juxtaposed therebetween, and concave wedges 44 and 46 are similarly paired.
The paired concave wedges (40, 42) and (44, 46) have adjacent concave wedges 40 and 44 merging with the juxtaposed convex sphere 30, and adjacent wedges 42 and 46 merging with the juxtaposed convex sphere 32. This merging by the adjacent ones of the concave wedges is with the associated convex sphere at the respective merger lines 34 and 36 as described hereinbefore. Outer edges 58 and 60 of adjacent wedges 40 and 44, respectively, are at the zero elevation of the primary surface 14 with outer edge 58 extending from merger line 34 to the line of origin 20, and with outer edge 60 extending from the merger line to the line of origin 22. A similar pair of outer edges 62 and 64 of adjacent wedges 44 and 46, respectively, extend from the central or intermediate merger line 36 to the respective lines of origin 20 and 22 as shown by FIG. 1. The paired outer edges (58, 60) and (62, 64) complement the respective merger lines 34 and 36, and develop ellipsoidal lines 66 and 68 of elevational demarcation between the zero elevation of the primary surface 14 and both the negative elevation of the concave wedges 40, 42, 44 and 46, and the positive elevation of not only the convex spheres 30 and 32 but also the convex plateau 18.
A fourth tool surface means on the hammer body 16 are planar and generally triangular surfaces on opposite sides of the convex plateau 18 at the intermediate region 24 and adjacent the respective convex spheres 30 and 32. One of the two similar triangular surfaces, planar triangular surface 70, is shown by FIG. 2. The triangular surface 70 has its apex 72 at the point of maximum positive elevation of the intermediate region 24, and has as its base the spherical portion 74 of the associated convex sphere, here convex sphere 32. The adjacent side surfaces 76 and 78 of the convex plateau 18 are arcuate, conforming to the flared dimension of the convex plateau at its region of maximum lateral dimension 26 and 28 as described hereinabove. It is understood that the opposite side of the convex plateau, although not shown, is similar to the side as illustrated by FIG. 2 and described above.
The hammer 12 of the invention as described produces the completed fastener head 80 as shown by FIGS. 4 and 5. The completed fastener head 80 has a flat top surface 82 and an undercut fastener driving slot 84 which is recognizable as a conventional high torque recess such as that of MS 33750.
The fastener slot 84 has an arcuate surface 86 as shown by FIG. 5 that has a preferred flat bottom 88 as shown by FIG. 4. The flat bottom 88 dimensionally flares transversely outwardly with reference to the longitudinal axis of the slot 84 reaching its maximum at each of the slot ends 90 and 92 which are at the zero elevation of the top surface 82. The edges 94, 96, 98, and 100 of the flat bottom 88 are shown in phantom and appear to be straight lines when viewed in plan as shown by FIG. 4. However, these bottom edges are arc segments and are undercut with reference to the respective parabolic surface edges 102, 104, 106, and 108 of the slot. Although the bottom edges 94, 96, 98, and 100 are uninterrupted between the respective slot ends 90 and 92, the parabolic slot edges 102, 104, 106, and 108 are interrupted by a concave speed dimple 110 which is specified for the high-torque fastener of MS 33750. Thus, slot edges 102 and 104 are interrupted by the concave hemisphere portion 112 of the speed dimple, and slot edges 106 and 108 are interrupted by the concave hemisphere portion 114. Each of the concave hemisphere portions 112 and 114 develop the curved baseline of a planar, generally triangular surface; for example, hemisphere portion 112 develops the curved baseline 116 of the triangular plane 118 as shown by FIG. 5. It is understood that hemisphere portion 114 develops a similar curved baseline for a triangular plane in the opposing slot sidewall. These triangular planes, such as triangular plane 118, form opposite parallel planes with their opposed walls parallel to the longitudinal axis of the slot 84. Note that the triangular planes, such as triangular plane 118, form an inverted triangle with its apex at the junction or midpoint of the associated bottom edges; here the bottom edges 94 and 96 associated with triangular plane 118. The spherical triangle portions 120, 122, 124, and 126, with spherical triangle portions 120 and 122 more clearly shown by FIG. 5, are canted to converge inwardly thereby developing the desired undercut configuration of this high torque fastener recess slot.
The resulting completed fastener slot 84 and fastener head top surface 82 with the speed dimple 110 as formed in part by the hammer 12 of the invention are both geometrically and visually identical to the requirements of MS 33750.
As will be evidenced from the foregoing description, certain aspects of the invention are not limited to the particular details of construction as illustrated, and it is contemplated that other modifications and applications will occur to those skilled in the art. It is, therefore, intended that the appended claims shall cover such modifications and applications that do not depart from the true spirit and scope of the invention. | An improved hammer used in the first step of a two-step method for forming an undercut fastener driving slot in the head of a fastener, such as a screw or bolt, that results in an arcuate, recessed high-torque driving slot with undercut slot sidewalls where each sidewall has a noncontinuous sphericity interrupted by an inverted and generally triangular planar surface. | 1 |
CROSS-REFERENCE(S) TO RELATED APPLICATION(S)
[0001] This application claims a benefit of priority under 35 USC §119 based on U.S. Provisional Patent Application No. 61/792,371, filed Mar. 15, 2013, the entire contents of which are hereby expressly incorporated by reference into the present application.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to the field of medical supply packaging. In particular, the invention is related to packaging and dispensing for protective eyewear glasses.
[0003] Manufacturers of protective eyewear glasses oftentimes package and ship products in conventional boxes. Once boxes arrive at a healthcare facility, they are typically opened and groups of protective eyewear glasses are stored in drawers or on shelves. When a pair of protective eyewear glasses is needed, a healthcare professional will typically look through the various drawers and/or shelves to retrieve them.
[0004] In some instances, once boxes arrive at a healthcare facility, protective eyewear glasses may remain permanently in the boxes until a pair of protective eyewear glasses is needed. Boxes may be placed on a shelf or in a closet, and when needed, a box is located by the healthcare professional and a pair of protective eyewear glasses is retrieved from the box individually. Each time a pair of protective eyewear glasses is retrieved, the entire box is opened and closed, thereby compromising the integrity of the box and potentially disheveling the contents of the box with retrieval.
[0005] These approaches often lead to inconvenience to the healthcare professional. In particular, locating a pair of protective eyewear glasses and/or a box containing protective eyewear glasses may be inconvenient and highly time consuming. As a result, in some instances healthcare professionals and/or patients may become inclined to avoid wearing protective eyewear glasses in some instances, thereby compromising personal safety. What is needed is a convenient and efficient way to store and distribute protective eyewear glasses in a healthcare environment.
SUMMARY AND OBJECTS OF THE INVENTION
[0006] In accordance with an aspect of the invention, methods and apparatuses are provided for packaging protective eyewear glasses in a manner allowing ease of distribution and use. Once a package in accordance with the invention arrives at a healthcare facility, the package may be inserted in a permanent wall-mounted location and a lower end of the package may be detached. As such, protective eyewear glasses may be singly retrieved until the package is empty, at which point, the package may be discarded with a replacement package being inserted in its place in the permanent wall-mounted location. As a result, a more convenient and efficient way to store and distribute protective eyewear glasses encourages healthcare professionals and patients to wear them and maintain personal safety.
[0007] Specifically, one aspect of the present invention includes a dispenser-package for storing protective eyewear glasses comprising an exterior box having a top, a bottom and four sidewalls along a first length, and an interior retention mechanism for holding a plurality of protective eyewear glasses along a second length. The exterior box completely receives the interior retention mechanism and securely holds the plurality of protective eyewear glasses in place. The exterior box includes a detachable area in proximity to the bottom to allow accessing one or more of the protective eyewear glasses held in place.
[0008] The interior retention mechanism may be substantially triangular in shape along the second length thereby allowing protective eyewear glasses to securely wrap around the interior retention mechanism. The protective eyewear glasses may be loaded and presented to a user upside down, with the protruding frame element of the glasses providing a convenient place to grasp and remove the glasses without depositing fingerprints or contamination on the glasses or lenses.
[0009] It is a feature of at least one embodiment of the invention to provide a design for easily and securely holding protective eyewear glasses in a queue, and presenting the protective eyewear glasses to a user in a manner to reduce fingerprints or contamination when retrieved.
[0010] Removal of a pair of protective eyewear glasses allows remaining protective eyewear glasses along the interior retention mechanism to slide downward to the bottom with gravity when the exterior box is positioned upright.
[0011] It is a feature of at least one embodiment of the invention to provide a mechanism for easy distribution of protective eyewear glasses without compromising the integrity of the package and potentially disheveling the contents of the box.
[0012] A spacer may be held within the exterior box between the end of the second length of the interior retention mechanism and the remaining portion of the first length of the exterior box for securely holding the interior retention mechanism in the exterior box.
[0013] It is a feature of at least one embodiment of the invention to securely hold the interior retention mechanism in place with respect to the exterior box.
[0014] The spacer held within the exterior box may be in proximity to the bottom. The spacer may also serve to position the protective eyewear glasses in such a way as to allow only one pair to be dispensed at time, thereby preventing the remaining protective eyewear glasses from falling out of the box and becoming contaminated or dirtied on the floor.
[0015] It is a feature of at least one embodiment of the invention to provide a rigid bottom for distribution of the protective eyewear glasses using an additional support.
[0016] An exterior enclosure may be used for rigidly supporting the exterior box.
[0017] It is a feature of at least one embodiment of the invention to provide reinforced support for the package on a reusable basis.
[0018] The exterior enclosure may comprise means for mounting the exterior enclosure to a wall.
[0019] It is a feature of at least one embodiment of the invention to provide a centralized location for the package for convenience and encouragement of use.
[0020] The interior retention mechanism can securely hold at least 24 protective eyewear glasses along the second length.
[0021] It is a feature of at least one embodiment of the invention to securely hold a bulk of protective eyewear glasses at a time.
[0022] An opening in a sidewall of the exterior box may be used for showing remaining protective eyewear glasses along the interior retention mechanism.
[0023] It is a feature of at least one embodiment of the invention to monitor the remaining protective eyewear glasses to facilitate timely reordering.
[0024] The opening may be in proximity to the bottom of the exterior box.
[0025] It is a feature of at least one embodiment of the invention to monitor nearing the end of protective eyewear glasses remaining.
[0026] These and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] A clear conception of the advantages and features constituting the present invention, and of the construction and operation of typical mechanisms provided with the present invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference numerals designate the same elements in the several views, and in which:
[0028] FIG. 1 illustrates a front perspective view of an assembled dispenser-package for storing and distributing protective eyewear glasses held in an exterior enclosure according to an embodiment of the invention;
[0029] FIG. 2 illustrates a rear perspective view of the assembled dispenser-package as shown in FIG. 1 ;
[0030] FIG. 3 illustrates a left side perspective view of the assembled dispenser-package as shown in FIG. 1 ;
[0031] FIG. 4 illustrates a right side perspective view of the assembled dispenser-package as shown in FIG. 1 ;
[0032] FIG. 5 illustrates a front perspective view of the exterior box of FIG. 1 ;
[0033] FIG. 6 illustrates a left side perspective view of the exterior box of FIG. 1 ;
[0034] FIG. 7 illustrates a right side perspective view of the exterior box of FIG. 1 ;
[0035] FIG. 8 illustrates a detachable area in proximity to the bottom of the exterior box of FIG. 1 to allow accessing one or more of the protective eyewear glasses held in place;
[0036] FIG. 9 illustrates an interior retention mechanism for holding the plurality of protective eyewear glasses according to an embodiment of the invention;
[0037] FIG. 10 illustrates the exterior box of FIG. 1 receiving the interior retention mechanism of FIG. 9 for securely holding the plurality of protective eyewear glasses in place;
[0038] FIG. 11 illustrates a front perspective view of the exterior enclosure for rigidly supporting the exterior box of FIG. 1 ;
[0039] FIG. 12 illustrates a rear perspective view of the exterior enclosure of FIG. 11 ; and
[0040] FIG. 13 illustrates a left side perspective view of the exterior enclosure of FIG. 11 ;
[0041] FIG. 14 illustrates a right side perspective view of the exterior enclosure of FIG. 11 ;
[0042] FIG. 15 illustrates a bottom perspective view of the assembled dispenser-package as shown in FIG. 1 ; and
[0043] FIG. 16 illustrates the bottom perspective view of FIG. 15 with bottom flaps opened.
[0044] In describing the preferred embodiment of the invention, which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents, which operate in a similar manner to accomplish a similar purpose. For example, the words “connected,” “attached,” or terms similar thereto are often used. They are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0045] The present invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments described in detail in the following description.
[0046] A dispenser-package for storing protective eyewear glasses and methods concerning the same are hereby disclosed. Beginning with FIG. 1 , an assembled dispenser-package 10 for storing protective eyewear glasses comprises an exterior box 12 having a top 14 , a bottom 16 and four sidewalls 18 along a first length from the top 14 to the bottom 16 . The dispenser-package 10 may be manufactured, for example, from conventional cardboard or paper. An interior retention mechanism 20 holds a plurality of protective eyewear glasses 22 along a second length from the top of the interior retention mechanism 20 to the bottom of the interior retention mechanism 20 . The exterior box 12 completely receives the interior retention mechanism 20 and securely holds the plurality of protective eyewear glasses 22 in place.
[0047] The exterior box 12 includes a detachable area 24 in proximity to the bottom 16 of exterior box 12 to allow accessing one or more of the protective eyewear glasses 22 held in place at a time. The detachable area 24 may be formed by perforations in the exterior box 12 , and may include one or more tabs for ease of removal of the detachable area 24 . As a result, the exterior box 12 in a first state, e.g., during shipment, may be fully enclosed without openings, while the exterior box 12 in a second state, e.g., during use in a healthcare facility, has an opening defined by the detachable area 24 . The exterior box 12 may include indentations, impressions, cut-lines and/or any other features facilitating area removal on or in proximity to the detachable area 24 to further facilitate such removal.
[0048] The exterior box 12 may also include a spacer 26 held within the exterior box 12 between the end of the second length of the interior retention mechanism 20 and the remaining portion of the first length of the exterior box 12 for securely holding the interior retention mechanism 20 in the exterior box 12 . As such, the spacer 26 minimizes movement of the interior retention mechanism 20 within the exterior box 12 . In a preferred embodiment, the spacer 26 is in proximity to the bottom of the exterior box 12 to increase rigidity of the bottom 16 after the detachable area 24 is removed. Accordingly, the spacer may serve to position the protective eyewear glasses 22 such that only one pair may be dispensed at time, thereby preventing remaining protective eyewear glasses 22 from falling out of the box and becoming contaminated or dirtied on the floor. In lieu of the spacer 26 , or in addition thereto, folds in the the exterior box 12 and/or the interior retention mechanism 20 , and/or stronger materials thereof, may provide equivalent functionality as desired. For example, as depicted in FIGS. 15 and 16 , at the bottom 16 , each side may fold in toward the center, and/or one side may include a flap that inserts into a slit on the opposing side, to securely hold the bottom 16 in position and to evenly withstand increased weight from above, with or without inclusion of the spacer 26 .
[0049] An exterior enclosure 28 substantially surrounds the exterior box 12 for rigidly supporting the exterior box 12 . The exterior enclosure 28 may comprise surrounding sides and a bottom for rigidly supporting the exterior box 12 , while leaving the top open and accessible to facilitate ease of insertion and removal of the exterior box 12 . The exterior enclosure 28 may be manufactured from any cost-effective, rigid material, such as plastic, and in a preferred embodiment, is manufactured from a rigid, transparent plastic.
[0050] The exterior enclosure 28 also comprises means for mounting the exterior enclosure 28 to a wall or other sturdy surface. In particular, the exterior enclosure 28 may include holes for positioning onto wall mounted screws, nails, hooks, or other fasteners, or may include hooks or other fasteners, adhesives, hook and loop fabric, angling of the exterior enclosure 28 for hanging over a surface, or any other similar mounting mechanism as known in the art.
[0051] In operation, the exterior box 12 containing the plurality of protective eyewear glasses 22 may arrive at a healthcare facility. The exterior box 12 may be alone or among other exterior boxes 12 in a larger shipping box, or the exterior box 12 may also serve as the shipping box with appropriate shipping labels affixed thereto. At the healthcare facility, the exterior box 12 may be inserted into the (empty) exterior enclosure 28 which is mounted in an appropriate and accessible location in the healthcare facility. Then, the detachable area 24 is removed by tearing away along perforations defining the detachable area 24 from the area in proximity to the bottom 16 of exterior box 12 .
[0052] Next, one or more of the protective eyewear glasses 22 are retrieved through the area now exposed by removal of the detachable area 24 . Removal of a single pair of protective eyewear glasses 22 allows remaining protective eyewear glasses 22 along the interior retention mechanism 20 to slide downward to the bottom with gravity when the exterior box 12 is positioned upright. Finally, once all of the protective eyewear glasses 22 have been removed, the exterior box 12 is removed from exterior enclosure 28 and a replacement exterior box 12 is inserted into the (empty) exterior enclosure 28 and the process is repeated.
[0053] In accordance with an embodiment, a method for storing the protective eyewear glasses 22 may comprise holding the plurality of protective eyewear glasses 22 in place along the length of the interior retention mechanism 20 , and placing the interior retention mechanism 22 completely in the exterior box 18 . The exterior box 18 , again, includes the detachable area 24 in proximity to the bottom to allow accessing one or more of the protective eyewear glasses 22 held in place.
[0054] Turning now to FIGS. 2-4 , rear, left and right side perspective views of the assembled dispenser-package 10 of FIG. 1 are shown, respectively. The rear of the exterior enclosure 28 includes a pair of mounting holes with grooves 30 for wall mounting. Similarly, the left side and the right side of the exterior enclosure 28 also include pairs of mounting holes with grooves 32 and 34 , respectively, for wall mounting.
[0055] In addition, the left side and the right side of the exterior box 12 include openings 36 and 38 , respectively, in sidewalls 18 of the exterior box 12 , for showing remaining protective eyewear glasses along the interior retention mechanism 20 to facilitate timely reordering. The openings 36 and 38 in sidewalls 18 are visible through the transparent exterior enclosure 28 . In a preferred embodiment, the opening openings 36 and 38 are in proximity to the bottom of the exterior box to monitor nearing the end of protective eyewear glasses 22 remaining.
[0056] An indicia for facilitating reordering of the protective eyewear glasses 22 may also appear on the exterior box 12 . The indicia may be, for example, a Quick Response (“QR”) Code, a barcode, a reorder number, reorder instructions, an Internet address, and so forth, which may be linked to or otherwise facilitate reordering of the protective eyewear glasses 22 . In a preferred embodiment, the indicia may be in proximity to the opening openings 36 and 38 such that monitoring nearing the end of the protective eyewear glasses 22 may conveniently accompany reordering the protective eyewear glasses 22 .
[0057] Turning now to FIGS. 5-7 , front, left and right side perspective views of the exterior box 12 of FIG. 1 are shown, respectively. The top 14 and the bottom 16 of the exterior box 12 may comprise a plurality of flaps for sealing the top 14 together and the bottom 16 together as in conventional boxes. In In addition, the exterior box 12 may collapse flat when the plurality of flaps for sealing the top 14 and the bottom 16 are fully opened, as in conventional boxes.
[0058] Turning now to FIG. 8 , a closer view of the detachable area 24 of the exterior box 12 of FIG. 1 is shown. Removal of the detachable area 24 allows accessing one or more of the protective eyewear glasses 22 when present. Impression areas 40 located in proximity to the lower side of the detachable area 24 allow ease of removal of the detachable area 24 by pushing against the impression areas 40 to begin breaking perforations that form the detachable area 24 . Alternative embodiments for the detachable area 24 may provide indentations, cut-lines, removable adhesives and/or other techniques as known in the art.
[0059] As shown in FIG. 8 , the spacer 26 is lifted upward from the bottom 16 of the exterior box 12 to reveal its additional detail. Accordingly, the spacer 26 may comprise a separate, detachable piece from the exterior box 12 formed of cardboard or paper folded together. An alternative embodiment may provide a spacer that is formed as part of the exterior box.
[0060] Turning now to FIG. 9 , the interior retention mechanism 20 holds the plurality of protective eyewear glasses 22 according to an embodiment of the invention. The interior retention mechanism 20 may be substantially triangular in shape along its length thereby allowing the arms of the protective eyewear glasses 22 to securely wrap around the interior retention mechanism 20 . As shown in the figures, the interior retention mechanism 20 may in fact appear trapezoidal in shape with respect to the exterior box 12 , although other shapes may be used, so long as they are conducive to retention of the protective eyewear glasses 22 within the exterior box 12 . As a result, the protective eyewear glasses 22 may be loaded and presented to a user upside down, with the protruding frame element of the protective eyewear glasses 22 providing a convenient place to grasp and remove the protective eyewear glasses 22 without depositing fingerprints or contamination on the protective eyewear glasses 22 or their lenses. The interior retention mechanism 20 is sized to substantially secure against the exterior box 12 when the exterior box 12 receives the interior retention mechanism 20 .
[0061] The interior retention mechanism 20 includes folding flaps 42 along its length, and along the apex area of the substantially triangular shape. The folding flaps 42 further allow guiding of the interior retention mechanism 20 into the exterior box 12 , further provide securely holding the protective eyewear glasses 22 inside the exterior box 12 , and further provide rigidity for the exterior box 12 once assembled.
[0062] Turning now to FIG. 10 , the exterior box 12 completely receives the interior retention mechanism 20 for securely holding the plurality of protective eyewear glasses 22 in place. The interior retention mechanism 20 slides into the exterior box 12 through the top 14 of the exterior box 12 .
[0063] Turning now to FIGS. 11-14 , front, rear, left and right side perspective views of the exterior enclosure 28 of FIG. 1 are shown, respectively. The exterior enclosure 28 is a transparent plastic and provides rigid support for the exterior box 12 . The rear of the exterior enclosure 28 includes the pair of mounting holes with grooves 30 for wall mounting. Similarly, the left side and the right side of the exterior box 12 also include the pairs of mounting holes with grooves 32 and 34 , respectively, for wall mounting.
[0064] FIG. 15 illustrates a bottom perspective view of the assembled dispenser-package as shown in FIG. 1 ; and
[0065] FIG. 15 illustrates the bottom perspective view of FIG. 15 with bottom flaps opened.
[0066] Additional features of a dispenser-package for storing protective eyewear glasses are shown in the illustrations in Appendix A attached hereto.
[0067] The individual components need not be formed in the disclosed shapes, or assembled in the disclosed configuration, but could be provided in virtually any shape and assembled in virtually any configuration. Further, although various embodiments of eye protection, face shields, head bands, and dispensers are described herein with certain features, any of the features may be combined with or removed from any of the embodiments. Furthermore, all the disclosed features of each dispenser may be combined with, or substituted for, the disclosed features of every other embodiment.
[0068] It is intended that the appended claims cover all such additions, modifications and rearrangements. Expedient embodiments of the present invention are differentiated by the appended claims. | Aspects of the invention provide a dispenser-package for storing protective eyewear glasses comprising an exterior box having a top, a bottom and four sidewalls along a first length, and an interior retention mechanism for holding a plurality of protective eyewear glasses along a second length. The exterior box completely receives the interior retention mechanism and securely holds the plurality of protective eyewear glasses in place. The exterior box includes a detachable area in proximity to the bottom to allow accessing one or more of the protective eyewear glasses held in place. As a result, a more convenient and efficient way to store and distribute protective eyewear glasses encourages healthcare professionals and patients to wear them and maintain personal safety. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/461,583, filed Aug. 17, 2009, now U.S. Pat. No. 8,889,201, entitled Method of Making Alcohol Concentrate, which claims the benefit of U.S. Provisional Application No. 61/136,242, filed Aug. 21, 2008, both of which are incorporated herein by reference in their entireties for all purposes.
COPYRIGHT
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
The present invention relates to alcoholic beverages, and particularly to a method of making an alcohol concentrate, especially a concentrate of beer, wine, alcohol-base ciders, and the like.
BACKGROUND OF THE INVENTION
Beer has long been a favorite recreational beverage among all classes of people. Beer has traditionally been considered a particularly satisfying beverage after spending long hours laboring or exerting one's self outdoors. There's nothing quite like a cold beer after a long, hard day working outdoors. Although water and energy drinks certainly fulfill one's needs for hydration and nutrition, they don't have the tang of hops or the bite provided by the alcohol in beer. There are some, however, who do not care for beer, but feel the same way towards a glass of wine or alcohol-based cider.
Such beverages, however, have high water content by volume due to the relatively low concentration of alcohol. For the dedicated outdoor sportsman, the high water content of such beverages is a problem because it increases the weight. When going hiking, camping, hunting, etc., the weight one has to carry must be minimized. It is often impractical to carry conventional bottles or cans of beer, wine, or cider on such overnight trips. Moreover, when shipping large volumes of beer, it is desirable to minimize freight charges. Although beer concentrates are known in home brewing, such concentrates are powdered and unfermented, and require considerable time and inconvenience to turn into a potable beverages.
Some breweries have been known to make a beer concentrate to decrease freight charges when shipping beer across the country. At its destination, the concentrate is reconstituted by diluting the concentrate with water to obtain the desired alcohol concentration and adding carbonation, as desired. The beer is then packaged for sale. In such cases, the beer concentrate is prepared by brewing beer with additional ingredients to produce a stronger beer that may be diluted after shipping. However, the beer concentrate itself is not available for sale directly to consumers.
In addition to the benefits of the concentrated beer itself, the process herein described for the production of a beer concentrate has several cost and energy saving benefits over the traditional process of beer production. In conventional beer brewing, a portion of the grain is malted to convert starches in the grain to sugars. The malt and unmalted grains are ground and mixed with hot water in a mash tun to extract the sugars from the grain. The water with the extracted sugars is filtered through a screen to remove most of the spent grain husks, and sprayed or sparged with additional water to remove any additional sugar from the remaining grain, husks, leaving a sweet liquid called the wort. The wort is boiled in a kettle, and hops and other flavor additives are added to the kettle. Boiling removes the bitterness from the hops and sterilizes the wort by killing wild yeast. The wort is cooled and transferred to a fermenter, leaving the spent grain and hops behind.
The wort is brought to a proper temperature (50°-70° F.) to promote fermentation, the wort is aerated or oxygenated, and yeast is pitched or added to the wort either before or after aeration. Fermentation may take place entirely in a single vessel, or in two vessels with repitching of yeast. Primary fermentation lasts about 3-5 days for ales, and longer for lagers. The yeast flocculates and falls to the bottom of the fermenter. At this point, most of the simple sugars and maltose will have been consumed. The fermentation may enter a secondary fermentation, in which the yeast breaks down more complex sugars. Secondary fermentation may last 1-3 days for ales, but up to one month for lagers. The finished beer is clarified and lagered.
Brewers typically use the boil time in the wort preparation process to achieve and regulate several desirable outcomes. Among the objectives of the wort boil are to pasteurize the wort, remove, or at least partially remove DMS compounds, and isomerize the bittering resins of the hops. Adequate pasteurization can be achieved in relatively short periods of time at boiling temperatures. However, DMS removal (or at least partial removal by evaporation) and hops isomerization and extraction require longer periods of time at the sustained temperatures of the rolling wort boil. Therefore, the extraction of the isomerized hops resin adds to the longer boiling times of most wort preparation. Longer boiling times means more energy invested by the brewer.
The culinary industry has long sought a beer concentrate for the addition of beer flavor to food. Beer itself contains too much water to be added to many recipes. Therefore, a beer concentrate is desired to impart full and authentic beer flavor to food without the undesired effects of adding unwanted water.
It would, therefore, be desirable to provide a beer, wine, or cider concentrate for purchase by consumers that can be reconstituted by simply adding water, and possibly carbonation. Thus, a method of making an alcohol concentrate solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
The present invention relates to a method of making an alcohol concentrate. The concentrate is achieved through a natural but modified fermentation process in which a plurality of existing separation technologies are employed at specific points within the process to yield a beer that has a very low water concentration, and can, prior to consumption, be reconstituted with water to yield a beer that is only lacking in carbonation. Carbonation can then be achieved through any number of traditional or novel methods.
One embodiment of the invention is a method for preparing an alcohol concentrate comprising the steps of: fermenting wort, removing alcohol and aromatics from at least a portion of the fermented wort, and reestablishing the fermentation in the distilled wort by adding additional fermentation ingredients and additional yeast as needed. The alcohol and aromatics may be removed in separate or combined streams, or may be removed under cool or normal temperatures. These steps may be repeated as needed to obtain a desired level of concentration of the fermented wort. The wort is further processed by removing water through reverse osmosis, evaporation, spray drying, or a combination of these applications, and recombining the distilled alcohol and/or aromatics with the concentrated fermented wort. The alcohol concentrate may be beer, wine, cider or other fermentable beverages. In another embodiment of the invention, additional flavor ingredients such as, but not limited to, hop oil and isomerized hop extracts may be added to the concentrated fermented wort.
Another embodiment of the invention is a continuous method for producing an alcohol concentrate, comprising the steps of: fermenting the wort until the desired (optimal) rate of fermentation of the wort has been achieved; diverting a volume of the fermented wort for yeast removal by centrifugation or filtration; and removing the alcohol and aromatics by vacuum distillation. The distilled portion of the fermentation is then refortified by addition of concentrated wort, pasteurized, and returned to the active fermentation.
Another embodiment of the present invention is a method for efficiently extracting hops resins, isomerized resins, oils and aromatics and the like from hops. In this embodiment, hops are added to the distilled alcohol and the pressure and temperature are varied for maximal extraction of hops.
These and other features of the present invention will become readily apparent upon further review of the following specification.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to a method of making an alcohol concentrate. The concentrate may be easily carried by hikers, campers, hunters, and the like, and may be reconstituted to form a potable beverage by hydration with water from streams, lakes, or other natural sources. The method will be illustrated by reference to a process for making beer concentrate. The method is similar for a wine concentrate or a cider concentrate. The process for making wine, for example, is similar to the process for making beer, except that wine is made from fruits that naturally contain sugar, whereas beer comes from grain and requires converting the starch in grains to sugar. As used herein, the term “wort solids” refers to the quantity of fruit (in the case of wine) or grain, malt, and hops (in the case of beer), plus any other flavor additives from which the wort is prepared.
There are immeasurable variations of ingredients and flavorings that are utilized by the brewing industry. The following process description therefore does not attempt to encompass all variations of the brewing process that are made possible either through ingredients or known modifications to the brewing process. Furthermore these steps can be employed by all nature of fermented beverages (cider, wine, etc) in order to achieve a concentrate of that specified beverage. In one embodiment of the method, a basic beer ingredient profile consisting of malted barley, hops, water, and brewer's yeast is considered. Moreover, for the purposes of designing a beer concentrate, it is advantageous to utilize concentrated wort (with water already significantly removed). Therefore, all discussion of “wort concentrate” will assume that the wort was prepared through standard procedures dictated by the nature and character of the beer being designed (including: mashing, lautering, sparging, etc.), and then evaporated or spray dried for partial or near total water removal. An example of one such commercially available concentrated wort that satisfies these basic qualities is “Concentrated Brewers Wort” made by Briess Malt and Ingredients Company.
In one embodiment of the present invention, the process is largely divided into three separate phases. The first phase is a “Nested Fermentation” cycle in which beer ingredients are added according to the desired character, flavor, and nature of the end product desired. Nested fermentation as used herein refers to multiple batches of fermentation using the same recycled aqueous solution. In this “Nested fermentation” phase of the process, the beer grows in concentration through an optionally repetitive cycle involving the removal of ethanol and other aromatics that represent a limiting barrier to the extent of fermentation achievable, and thus the final production of alcohol as a result of fermentation. The brewer must determine how many repetitive cycles of nested fermentation to utilize, and subsequently what the desired level of concentration of the fermented wort will be. Each additional round of nested fermentation naturally results in a greater degree of concentration of fermented wort; however each round also costs the brewer additional time, energy, and resources. Additionally, as the fermented wort becomes more concentrated, the brewer will need to compensate for the higher starting gravities of the wort during each subsequent nesting cycle. This is typically managed through strict adherence to wort nutrition and attention to large healthy yeast propagations prior to the start of fermentation. However, both of these criteria add a complexity and cost to the brewing operation. As the starting gravity of the wort continues to increase with each nesting cycle, so too does the time required for fermentation. When the benefits and costs of additional rounds of nested fermentation are considered, the brewer must make a determination as to how many cycles of nested fermentation will be cost effective, time efficient, and practical given the specific nature of the designed beer of interest. In practice, nested ferments with starting gravities of over 1.17 g/ml have been achieved. However, due to the magnitude of compensations required for these non-ideal conditions, these fermentations were considered to be impractical for industrial production purposes. Largely speaking, it is recommended that when the investment of resources allocated to achieve additional levels of concentration through the nested fermentation process equals those required to achieve that same increase in concentration through a selected/specified water removal process (to be described here after), the brewer abandon the nested fermentation process in favor of direct water removal. At this point the brewer has achieved the desired level of concentration of fermented wort through the nested fermentation phase.
The second phase of the process requires water to be extracted and removed from the de-alcoholized beer by reverse osmosis, evaporation, spray drying, or a combination of these processes. Removing water through a reverse osmosis, evaporation, or spray drying processes is well known to one of ordinary skill in the art. The third phase of the process requires the reuniting of previously separated and processed components of the beer process, other than the intentionally removed water. In this phase, the concentrated “bottoms” product is mixed with the alcohol and aromatics that were removed during the nested fermentation cycle, thus combining all components of the fermentation process, except for the water previously removed by reverse osmosis, evaporation, or spray drying. During this last phase of the process additional flavorings can also be added, such as hop oils/extracts, to modify the flavor profile of the beer. A more detailed description of nested fermentation, water removal, and reconstitution of the separated components are given in the description below.
The concentrated or non-concentrated wort is prepared through traditional wort preparation steps or by the addition of concentrated wort, hops, if desired, for anti-microbial effects or early bittering, water, and any required nutritional additives. A yeast slurry is prepared with a proportionately appropriate cell count designed for the volume and specific gravity considerations of the wort. This yeast slurry is propagated in an oxygenated environment that is fortified with minute doses of olive oil, both of which are known to the brewing industry to help support robust and healthy cellular material in yeast. If the volume of the yeast slurry is determined to be greater than the volume desired to be added to the wort, the yeast slurry can be chilled to cause the yeast to floculate and settle to the bottom of their container. The clarified wort, separated from the yeast cake, can then be decanted, leaving the yeast cake intact. A small amount of oxygenated wort can be added to this yeast cake and mixed while the slurry returns to active temperatures and the yeast resumes active/observable metabolism. This now-concentrated yeast is then pitched to the wort. Although the wort may be aerated during the initial fermentation cycle, subsequent fermentations within the nested fermentation cycle should avoid the aeration of the newly prepared wort. This is due to the potential for adverse oxidative effects of the post-fermentation de-alcoholized beer components.
The beer is preferably fermented for approximately 6-7 days. After it has undergone a diacetyl rest, it is processed for the removal of suspended yeast. This can be accomplished by either centrifugation or filtration. The beer is then processed through vacuum distillation to remove the delicate aromatics, and the alcohol (primarily ethanol). Depending on the degree of concentration of these “top products” the two distillate streams can either be combined and stored for a later addition to the concentrated de-alcoholized beer, or they can be stored separately if it is desired for either of them to undergo additional, separate processing. Additional processing options include, but are not limited to: steeping vegetative hops products in the distilled ethanol under high pressure/temperature in a closed system for bittering and aromatic hops addition, or further distillation of ethanol to increase its degree of concentration.
There are many vacuum distillation systems known to the brewing industry that can function for this separation process. Some employ spinning cones that create a thin film of material that is warmed and exposed to vacuum conditions, while others employ rising/falling film systems that are subjected to vacuum conditions. These systems are used primarily for the production of non-alcoholic, or low-alcohol beer. Regardless of basic design considerations, the essential components and modifications of this equipment must support the near total removal of aromatics and alcohols under low temperature conditions. The equipment may furthermore be modified to reclaim the aromatic distillate and ethanol distillate streams separately, nearly completely, and to a high level of concentration.
Once the alcohol and aromatics have been separated, collected, and stored according to the design and desire of their further processing, additional concentrated wort can be added and blended with the de-alcoholized beer. The de-alcoholized beer will still have residual, isomerized bittering hops compounds present, if initially added, from the first fermentation cycle, and will also have the water that was used during the first fermentation cycle. Some water will have been removed during the vacuum distillation process, and therefore a small amount of water will need to be added to the wort. However, the yeast slurry, potentially concentrated through chilling/decanting as described previously, that is added after pasteurization will increase the total volume of the wort, and should be considered before additional water is added. The concentration achieved through the nested fermentation cycle is derived from the re-utilization of brewing water to effectively layer or “nest” multiple batches of beer within the same recycled volume of aqueous medium.
The wort is then pasteurized by UV exposure, irradiation, or other viable pasteurization methods that do not degrade the matrix of thermally sensitive flavor components that are residuals from the previous round(s) of fermentation. However, if there are hop bittering compounds in the wort, UV exposure should be avoided. Such methods would be readily apparent to one of ordinary skill in the art. The propagated/prepared yeast is then pitched to the wort, and a new round of fermentation is initiated.
Each time a beer undergoes these sequential steps, it will become denser (increasing its specific-gravity) due to the remainder of non-fermentable ingredients and non-distillable (bottoms) products derived from the fermentation process. The steps of the nested fermentation cycle are repeated until the starting gravity of the wort becomes a limiting factor to the efficiency of fermentation (unproductively high starting gravity), or the brewer otherwise determines that the desired level of concentration of fermented wort has been achieved, and is therefore ready to move to the water removal phase of the concentration process.
During the beer's final nested fermentation cycle, the beer is transferred to a secondary fermenter for an additional period of time (approximately 5-7 days) immediately after completion of the primary fermentation and diacetyl rest. This allows for clarification and more complete fermentation of the beer, which is referred to as full attenuation.
It is important to note that the nested fermentation cycle is not essential to creating a beer concentrate. This embodiment of the invention makes it possible to take beer from its very first pass through the vacuum distillation process and immediately move the de-alcoholized product down line for water removal (reverse osmosis, evaporation, or spray drying). However, the effect of the nested fermentation loop is that, by re-using the same volume of water for multiple fermentation cycles, the brewer invests very little energy to the system to gain significant yields in concentration. The energy demands of removing the relatively small quantity of alcohol and aromatics through vacuum distillation are significantly less than the energy demands of water removal (larger volume, and lower vapor pressure) under vacuum conditions. Furthermore, several acceptable pasteurization methods exist that allow the brewer to loop the de-alcoholized and refortified beer back through additional fermentation cycles without the need of bringing the product to higher temperatures, as is done in traditional wort preparation and heat pasteurization processes.
Table I illustrates the degree of nesting with the associated degree of concentration achieved through the nesting phase of the concentration process. A first-degree nested beer is one that has undergone only one round of fermentation, and has then passed through the vacuum distillation phase, thus offering no gains in concentration.
TABLE I
Degree of Nesting
Beer concentrate:
Degree
Starting
Ending
Rehydrated beer
Nested
Gravity
Gravity
(by volume)
1
1.05
1.012
1:1
2
1.062
1.024
1:2
3
1.074
1.036
1:3
4
1.085
1.047
1:4
The beer industry has long been aware of the benefits to brewing beer concentrates. Many large brewing companies utilize these advantages to reduce transportation costs of large shipments. It is not uncommon for large brewers to craft their beer with additional ingredients in order to yield a stronger, more concentrated, product. This more concentrated product can then be shipped, and upon reaching the point of bottling or distribution, water and carbonation are added so that the end product is reflective of the qualities desired in the designed beer.
These basic procedures can be incorporated into the nested fermentation cycle to produce even greater concentrations in shorter periods of time. For example, by adding 50% more concentrated wort to the start of a fermentation cycle; the resulting beer will yield 50% more alcohol, aromatics, and other characteristic beer flavor components. The brewer must be careful not to over fortify the wort with too much additional fermentable ingredient. To do so would create the obvious difficulty of a high gravity environment coupled with the potential for unachievable levels of alcohol (largely dictated by the strain of yeast being used), which would thereby render the beer under-attenuated through an unattainable fermentation demand. Table II illustrates these findings and associated gains in the level of concentration of the product when additional ingredients are added. In this profile, even a first-degree nested beer yields a degree of concentration, relative to the increased percentage of fermentable ingredients.
TABLE II
Effect of Starting Gravity
Starting
Ending
Beer concentrate:
Degree
Gravity
Gravity
Rehydrated beer
Nested
(g/ml)
(g/ml)
(by volume)
1
1.075
1.018
1:1.5
2
1.093
1.036
1:3
3
1.111
1.054
1:4.5
4
1.129
1.071
1:6
Regardless of how many nesting fermentation cycles the beer undergoes, or what level of concentration is achieved as a result of the nested fermentation cycles, the de-alcoholized beer still contains considerable weight and volume of water. This water must be removed to further increase the level of concentration of the product.
In the second phase of this embodiment of the invention, the de-alcoholized beer, either partially concentrated through the nested fermentation cycle or not, is drawn through an evaporation or spray drying process, thereby removing either significant or nearly total quantities of water. Both processes yield benefits and disadvantages. Spray drying is advantageous due to the almost complete removal of water from the product, but has been perceived to offer slight flavoring disadvantages, partly due to the operating temperatures of most spray drying equipment. Also, spray drying typically uses substantially more energy than evaporation. Low temperature evaporation conducted under vacuum helps protect delicate flavors of the product, but does not remove as much water as the spray drying process. It is therefore envisioned that these two separation techniques will be evaluated by the brewer with the desired qualities of the end product and their separate limitations in mind. In addition or alternatively to the aforementioned water removal options of evaporation and spray drying, reverse osmoses offers the brewer an energy saving option for the removal of notable quantities of water. Although reverse osmoses has not reviled itself to be as effective as evaporation or spray drying in its ability to remove water from the fermented wort concentrate, it does offer some advantages due to its relatively low capital and operational costs. Additionally, by integrating a reverse osmosis water removal process prior to a more substantial water removal processes (as in evaporation or spray drying), the brewer can reduce the energy demands of the water removal phase of the process, while still achieving a high degree of water removal. The utilization of reverse osmosis systems in the brewing industry is readily known to one who is skilled in the art. In particular, reverse osmoses is a process sometimes used in the production of non alcoholic or low alcohol beers.
In the third phase of this embodiment of the invention, the remaining concentrate, with water removed, must be reunited with the alcohol and aromatics that were removed during the previous nested fermentation cycles. The concentrated/de-alcoholized beer is blended with the distilled/collected alcohol (primarily ethanol) and distilled/collected aromatics recovered through the vacuum distillation steps performed during the nesting fermentation phase of the process. Additional flavor components can also be added (such as hop oil, or isomerized hops extract) to adjust the final flavor profile of the beer.
This concentrated product now represents the naturally fermented, desirable beer flavoring components with the majority of water removed from the system. The product is ready for packaging and transportation in its efficiently concentrated state. To prepare the beer for consumption, an appropriately measured volume of water is added to the beer concentrate based upon the final degree of concentration of the product. The beer is then carbonated appropriately to support the desired flavor profile of the designed beer. Alternatively, the water can be carbonated prior to blending with the beer concentrate, as is typical of soda fountain dispensers.
Another embodiment of the invention provides for continuous fermentation. The nested fermentation process described previously outlines a batch process. It is also desired to have available a continuous operation that would reduce/remove the lag time typically associated with the first 24-48 hours of fermentation. The following modifications to the nested fermentation process allow the brewer to utilize a continuous process in order to achieve an alcohol concentrate. The continuous operation is basically parallel in format to the batch process, except that fermentation remains active while only a portion of the fermentation is removed for yeast removal, vacuum distillation, refortification of ingredients, pasteurization, and return to the fermenter.
In the continuous method, a batch of green beer is allowed to proceed until a desired rate of fermentation is reached. “Green beer,” as used herein, refers to a fermented but unfinished beer. In this application the desired rate of fermentation is understood to be the peak rate of observable anaerobic yeast metabolism for the current/dedicated volume of ferment. A brewer can observe and keep record of a beers rate of fermentation through a myriad of techniques known to the industry. Three common methods involve frequent gravity (density) measurements being taken by use of a hydrometer, use of a refractometer to track the concentration of available sugars in the ferment, or by the observance of CO2 (which is a product of fermentation) production during the fermentation. By comparing subsequent measurements over closely recorded periods of time, these methods provides the brewer with a means of determining the rate of metabolic activity of the yeast, and can thereby be used in determining when the peak, desired rate of fermentation has been achieved.
When the desired rate of fermentation has been observed, a volume of green beer is then diverted for yeast removal by centrifugation or filtration. These yeast removal techniques are known and standard in the art. Next, ethanol and aromatics are removed from the green beer through vacuum distillation, as described previously. The de-alcoholized green beer is then refortified with concentrated wort, pasteurized, and returned to the fermenter where the remainder of the green beer is still actively undergoing fermentation. Additional yeast may be pitched to replace the yeast that was removed during centrifugation/filtration. Excessive build-up of dead yeast material should be continuously removed from the bottom of the fermenter. By regulating the frequency and volume of the green beer that is removed for processing, the brewer can maximize and sustain the rate of fermentation to reduce residency times of the fermentation equipment, thereby increasing efficiency.
Once the green beer within the fermenter has reached the desired level of concentration, or the specific-gravity has become too great to efficiently support additional fermentation, it is held in the primary fermenter long enough as to support a sufficient diacetyl rest. It is then transferred to a secondary fermenter, where it is allowed to clarify and fully attenuate. Upon completion of the secondary fermentation, the entire volume is transferred through the yeast removal and de-alcoholization (vacuum distillation) process. The concentrate can then be processed through the water removal steps described previously.
By processing the green beer that is removed for de-alcoholization in a closed sanitary (and sanitized) system, the brewer can greatly minimize the need for pasteurization of the de-alcoholized green beer prior to returning it to the fermenter. In this case the concentrated wort that is used to refortify the de-alcoholized green beer can be pasteurized separately. This concentrated wort is less susceptible to thermal degradation than the green beer itself, and may alternatively be added directly to the fermenter as the processed de-alcoholized green beer is returned. Furthermore, by maintaining an ongoing fermentation with a high healthy yeast cell count, the brewer minimizes the likelihood of microbial contaminations taking root within the fermenting green beer.
By modifying the nested fermentation cycle to operate continuously at, or near, peak fermentation, the brewer minimizes the residence time of the green beer, thereby reducing the overall time required to complete this phase of the concentration process.
Either of the aforementioned methods (batch or nested fermentation) can be modified for efficient extraction of hops oils, aromatics, resins, bitters and other desirable components from hops. Hops are one of the dominant flavoring ingredients in beer. Many varieties exist, and are selected by the brewer based upon a number of criteria. Some are preferred for their bittering qualities, while others possess desirable aromatic benefits. In addition to adding flavor and aroma to the beer, hops are also known to posses anti-microbial benefits, thus helping prevent the finished beer from becoming infected with adverse biological agents. Hops is traditionally considered one of the most underutilized ingredients in beer, meaning that only a small percentage of the desired qualities of the hops plant are extracted through the traditional brewing process. More time, higher heat, and better solvents all yield gains in hops extraction efficiency. Unfortunately traditional brewers are limited to a large extent by the disadvantages of the traditional brewing process, where, other than time, these variables are largely static. The upper temperature of hops extraction for most brewing operations is the boiling temperature of water, with compensation for elevation. The solvent used for the hops extraction is simply the water of the wort. Time is the only variable that is readily manipulated to create variations in hops extractions, and is used by brewers to customize a beer's hops profile.
In contrast to these traditional limitations, the batch or continuous methods can be modified to allow hops to be extracted through a novel and efficient mechanism whereby the hops (whole leaf, pellet, or other vegetative form) are added to the entire amount of collected (distilled) alcohol. Thus, the brewer is able to use the very same ethanol that was produced during fermentation as the solvent for the extraction of hops. Ethanol is far superior for this purpose than water, and by creating a closed system that is held under pressure, the brewer can increase the temperature of the system beyond the boiling temperature water to allow an even greater yield of desired hops components. By adjusting the pressure of the closed system, the brewer can manipulate both time and temperature of the hops extraction process. It is recommended that the pressure of the system be selected and maintained based upon the desire to limit the amount of ethanol and aromatic compounds that contribute the vapor phase of the closed system during the extraction process at the targeted extraction temperature. It is further recommended that nitrogen be used to establish pressure within the closed system prior to heating of the system. Nitrogen is preferred for its inert qualities. The duration of the extraction may vary, depending on the temperature and pressure used. Furthermore, the closed system allows the brewer to capture the delicate hops oils (aroma compounds), that are usually lost when hops are boiled for long periods of time as in an open wort boil. At the end of the extraction process the hops and ethanol mixture is cooled, the pressure is slowly relieved, and the vegetative hops material can be separated from the extraction solvent. By chilling the liquid prior to relieving the pressure, the brewer assures that minimal aromatics are lost as vapor. These advancements and options in hops extraction collectively represent an alternative higher degree of efficiency of hops utilization to the brewer, thereby reducing the quantity of hops needed to achieve the desired hops character in the designed beer. With hops being a large and volatile cost within the list of beer ingredients, this efficiency represents a significant cost savings to the brewing process.
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 following claims. | One embodiment of the present invention is a method for making a beverage, such as an alcoholic or non-alcoholic beer, the method comprising performing a first fermentation step using a first set of fermentation ingredients to create a first fermented solution; removing a first collection of alcohol and aromatics from the first fermented solution to create a first de-alcoholized solution; adding a second set of fermentation ingredients to the first de-alcoholized solution; performing a second fermentation step using the second set of fermentation ingredients in the first de-alcoholized solution to create a second fermented solution; creating a beverage, wherein creating the beverage comprises using the second fermented solution and at least a portion of a previous collection of alcohol and aromatics. | 2 |
[0001] This application claims the benefit of U.S. Provisional Application No. 60/339,078, filed Oct. 30, 2001.
FIELD OF INVENTION
[0002] The present invention relates to methods and apparatus for producing carbon nanotubes, by vaporizing carbonaceous material, and metallic catalytic materials in a high temperature environment produced by a plasma, and, more particularly, to the production of single walled nanotubes “SWNTs” using a radio frequency generated plasma as the heat source to vaporize the carbonaceous and catalytic materials.
BACKGROUND OF THE INVENTION
[0003] Because of their unique structure, physical and chemical properties the recently discovered fullerene nano-tube (Single-Walled Nano-Tubes; SWNT) materials have been investigated for many applications. Indeed this is one material from which the application development has out-paced its mass availability. The most added-value applications that are being developed using nanotubes include Field Emission Devices, Memory devices (high-density memory arrays, memory logic switching arrays), Nano-MEMs, AFM imaging probes, distributed diagnostics sensors, and strain sensors. Other key applications include: thermal control materials, super strength (100 times steel) and light weight reinforcement and nanocomposites, EMI shielding materials, catalytic support, gas storage materials, high surface area electrodes, and light weight conductor cable and wires. Carbon fibers and whiskers, both of which are carbon forms other than nanotubes, have been synthesized for many decades, and have revolutionized structural materials in almost every application where lightweight and high strength are desirable qualities. Much smaller than fibers or whiskers, carbon nanotubes were discovered only recently [S. Ijima; Nature, 354, p56 (1991)].
[0004] However, to utilize this unique material in applications a high volume industrial process that can produce these nanotubes at low cost and with the required purity and physical properties (controlled length and chirality) needs to be developed. The approach is to use low cost solid starting raw materials such as carbonaceous materials “derived from Coal” both as a source of carbon and as a source of some if not all the catalyst for the growth of the SWNT. For additional catalyst materials also solid catalyst can be used. Currently, SWNT are produced on a discrete run basis by the vaporization of metal-graphite composites either in an electric arc discharge [S. Iijima and T. Ichihashi, “Single-Shell Carbon Nanotubes of 1-nm Diameter,” Nature 363, 603-605 (1993) and D. S. Bethune, C. H. Kiang, M. S. deVries, G. Gorman, R. Savoy, J. Vasquez, R. Beyers; Nature, 363, 605-607 (1993); D. S. Bethune, R. B. Beyers, C. H. Kiang, “Carbon Fibers and Method for Their Production”, U.S. Pat. No. 5,424,054 (1995).], or by laser pulses [P. Nikolaev, A. Thess, R. E. Smalley, “Catalytic Growth of Single-Walled Nanotubes by Laser Vaporization,” Chem. Phys. Lett. 243, 49 (1995)]. In the arc discharge process, a carbon anode loaded with catalyst material (typically a combination of metals such as nickel/cobalt, nickel/cobalt/iron, or nickel and transition element such as yttrium) is consumed in arc plasma. The catalyst and the carbon are vaporized and the SWNT are grown by the condensation of carbon onto the condensed liquid catalyst. Sulfur compounds such as iron sulfide, sulfur or hydrogen sulfides are typically used as catalyst promoter to maximize the SWNT yield. When using the existing method based on arc discharge, it is difficult to increase the amount of vaporized carbon, and it is difficult to control the process parameters of the arc. In the arc the carbon rods act as the feed materials and the source (electrodes) for arc discharge. Accordingly, it is difficult to control separately these functions. This result in limited production of carbon nanotubes and in a product that is highly contaminated with other clustered carbon materials, causing the high cost of mass production. The cost of SWNT is determined by the production rate, yield, raw materials cost. The raw materials consist of carbon source, catalyst and promoters. The use of solid carbon particulate such as coal as source of carbon and some if not all of the catalyst and promoter could lead to tenfold savings in raw materials costs. The use of plasma source of intense heat can result in complete vaporization of the solid feed materials, and very high rate of production. The separation of feed materials from the source of heat gives full control of the process to maximize yield. This creates the opportunity for effective and inexpensive mass production of carbon nanotubes.
[0005] SWNT are synthesized using a gas catalytic process wherein carbonaceous material is vaporized by the application of heat under conditions appropriate to produce the SWNT. Although the mechanism is poorly understood, it is theorized that the gas synthesis process can be generally divided into three separate sub-processes. One of the sub-processes is nano-catalyst formation process, which involves the vaporization of metal catalyst and the subsequent formation of active metal nanoparticulates. Another step is sublimation/vaporization of carbon to form carbon cluster in the gas phase. This step might be eliminated if gaseous carboneous source is used. The final sub-process is the carbon nano-tube growth process, which involves the dissolution of the carbon clusters into the metal catalyst nanoparticulates, and subsequent growth of SWNT from the carbon supersaturated catalyst. This mechanism seems to be the most accepted mechanism. In the nano-catalyst formation process, parameters such as surface tension of the catalyst nanoparticulates, nanoparticulate size, shape, density and its distribution parameters are of importance to control the diameter of nanotubes and the yield. For the SWNT growth process, important parameters will include carbon vapor density and carbon saturation in catalysts, the residence time of the nanotube-growing catalyst in the gas at appropriate temperature.
[0006] Current modes of SWNT production involve the use of catalyst-packed graphite rods [D. S. Bethune et.al], or catalyst impregnated graphite rod [X. Lin, X. K. Wang, V. P. Dravid, R. P. H. Chang, J. B. Ketterson, “Large Scale Synthesis of Single-Shell Carbon Nanotubes, Appl. Phys. Lett., 64(2), 181-183 (1994).], which are consumed in a DC electric arc to produce SWNT-containing soot. A variation of the packed rod technique utilizes the catalyst as a molten metal in a small crucible onto which a graphite rod is arced, thereby co-vaporizing carbon and catalyst to form several grams of SWNT per operation [S. Seraphin and D. Zhou, “Single-Walled Carbon Nanotubes Produced at High Yield by Mixed Catalysts,” Appl. Phys. Lett. 64, 2087-2089 (1994).] has also been developed. The product of the arc-based production methods contains SWNT that are coated with amorphous carbon, as well as other contaminants including amorphous and graphitic carbon particles, carbon-coated metal catalyst particles, and traces of fullerenes-C 60 , -C 70 , etc. Separation schemes have been devised to remove the contaminant [H. J. Dai, A. G. Rinzler, P. Nikolaev, A. Thess, D. T. Colbert, and R. E. Smalley, “Single-Wall Nanotubes Produced by Metal-Catalyzed Disproportionation of Carbon Monoxide,” Chem. Phys. Lett. 260, 471-5 (1996)], which allow limited (1-10%) recovery of pure tubes. Relatively pure SWNT have been produced [A. Fonseca, K. Hernadi, P. Piedigrosso, J. -F. Colomer, K. Mukhopadhyay, R. Doome, S. Lazarescu, L. P. Biro, P h. Lambin, P. A. Thiry, D. Bernaerts, J. B. Nagy, Synthesis of Single- and Multi-Wall Carbon Nanotubes Over Supported Catalysts, Appl. Phys . A67, 11-22 (1998).; K. Hernadi, A. Fonseca, J. Nagy, D. Bernaerts, A. Lucas; Carbon, 34, 1249-1257 (1996); H. M. Cheng, F. Li, X. Sun, S. D. M. Brown, M. A. Pimenta, A. Marucci, G. Dresselhaus, and M. S. Dresselhaus, “Bulk Morphology and Diameter Distribution of Single-Walled Carbon Nanotubes Synthesized by Catalytic Decomposition of Hydrocarbons,” Chem. Phys. Lett. 289, 602 (1998); H. M. Cheng, F. Li, G. Su, H. Y. Pan, L. L. He, X. Sun, and M. S. Dresselhaus, “Large-Scale and Low-Cost Synthesis of Single-Walled Carbon Nanotubes by the Catalytic Pyrolysis of Hydrocarbons,” Phys. Lett. 72, 3282 (1998).] by use of gaseous carbon sources decomposed over catalyst particles either supported on inert solids or floating in gas reaction media. Several tens of grams of high-yield SWNT samples were produced whose properties varied greatly depending on the reagent gas used and the method of catalyst particle preparation. Laser vaporization of catalyst/carbon composite rods has produced over 50% yield (relative to initial carbon input) of SWNT, however, with a slower production rate compared to arc process. While some of these methods for SWNT production produce high-yield products and others are touted as “Large-Scale” processes, none produce high yield SWNT on a continuous basis with control over all production variables.
[0007] Williams and et al [K. A. Williams, M. Tachibana, J. L. Allen, L. Grigorian, S-C. Cheng, S. L Fang, G. U. Sumanasekera, A. L. Loper, J. H. Williams, and P. C. Eklund, Chemical Physics Letters, (310) 1-2, 31 (1999).] have investigated the production of SWNT from untreated bituminous coal, and they showed that SWNT can be produced, but with twofold to fourfold reduction in the purity. It was interestingly found that transition metal impurities such as pyrite in bituminous coal may actually contribute a synergistic catalytic effect and it might be possible to produce SWNT from pyrite rich bituminous coal without adding any catalyst. However, the presence of sulfur dramatically decreases the yield.
[0008] In case of coal as the particulate solid carbon source, the best coal for SWNT feedstock is one that has a high fixed carbon content and low volatile component. Two ways to use the coal have been investigated in the present invention. One, as a comparison, is to form conductive rods to be used in the arc process, and the other way is to use the coal as powder feed in the plasma reactor. Initial attempts to make rods from untreated coal failed due to excessive evolution of gas in the rods resulting in cracking of the rods during carbonization. Furthermore, for powder feed it is essential to have free-flowing powder. Accordingly, volatile component of the coal also had to be removed. Since pretreatment is required, just about any coal can therefore be used and treated to obtain its fixed carbon content. Removing the volatile component can improve the yield of SWNT production as a result of the decrease in oxygen content.
[0009] Accordingly, the present inventors have developed methods that incorporate the most successful aspects of existing SWNT production to establish the feasibility of using solid carbon such as coal including anthracite, as a source of carbon, together with a catalyst, as a way to potentially reduce the cost and produce high yield SWNT.
[0010] Moreover, the present inventors have shown that using hydrogen in the presence of iron sulfide or sulfur catalyst promoter significantly increases the yield of SWNT when using particulate solid carbon such as coal as the carbon source.
[0011] A quantitative treatment addressing physiochemical mechanisms and transport processes associated with SWNT synthesis has also been proposed by the present inventors to improve production and materials development. The composition of solid carbon or of coal, size, concentration of the metal catalyst from the coal and the concentration of the carbon clusters, together with the temperature profile as they relate to yield of SWNT production was used as an input into the physiochemical mechanistic model.
[0012] The technical feasibility of efficiently using particulate solid carbon such as coal as the carbon source to produce SWNT, in substantially continuous reactor has been demonstrated as described herein.
[0013] Although relatively large production of multi-walled carbon nanotubes is carried out in Japan (Showa Denko) where they have built and operated a 5 meter long, with 1 meter diameter reactor, the reactor is thermally controlled with an upper operating temperature of 1200° C. Under these conditions only multi-walled nanotubes MWNT can be produced, but SWNT can not be produced economically.
[0014] One objective of the present invention is to develop an improved scaled-up reactor where key process parameters can be controlled independently for the economical production of high yield of SWNT using particulate solid carbon source including such as coal based materials.
[0015] High-temperature plasma offers a convenient and advantageous source for the vaporization of carbon. It is relatively easy to produce and control, and carbonaceous and solid catalyst materials can be injected into a flowing-gas fed plasma. The flow of gas and the ability to control the volume, temperature and location of the plasma make production and collection of nanotubes with controlled properties on a continuous basis easier than in arc based reactors. Hot plasma is formed when the temperature of ions, electrons and internal particles corresponds to the thermal equilibrium conditions, at pressure of about 100 Torr and more, this temperature may be as high as 5,000 to 20,000 K. At pressure of less than 100 Torr, the temperature of ions, electrons and internal particles corresponds to non-equilibrium cold plasma and runs around 100 to 1,000 K. Hot plasma generated by using high frequency induction coils is called ICP (Inductively Coupled Plasma) and cover wider region as compared to plasma generated by DC arc discharge method, which allows preventing mixing in possible impurities from the electrode materials. Using the Hot ICP plasma method, it becomes possible to vaporize larger quantities of carbon powder and catalyst and mass-produce the carbon nanotubes. Several approaches to using plasma to vaporize coal and metal catalyst precursors for SWNT production were investigated by the inventors.
[0016] There are several approaches to create hot plasma. In one approach the plasma is created by an electric arc between electrodes located in a tube through which a flowing stream of gas is maintained. This is typically called “Plasma Spray Torches”. The plasma torch can be viewed as modified arc discharge described above except the electrodes are non-consumable. The flow of gas forces the plasma plume out of the tube. Powders are introduced either into the gas stream or are injected just in front of the torch tube. The powder is rapidly heated, and the high velocity gas stream causes the molten particles to splatter onto an object to be coated or collected in a bag filter. Different gases torch design and applied power account for the temperature of the plasma and therefore determine the rate at which powder can be fed into the torch and the temperature of the emitted particles. The inventors tested this type of plasma spray systems for SWNT production using solid carbon and catalyst feed materials. Samples of ball-milled carbonized coal/catalyst powders were introduced into a Metco model 7M-plasma sprayer. Argon/helium gas mixtures were used in the experiment, and the powder was introduced into the plasma by a powder feeder that injects a stream of argon with entrained powder into the plasma directly in front of the torch.
[0017] With most metals and ceramics that are used in coatings, the metal powder is melted enough to adhere to the object that is being coated. For SWNT production, the carbon/catalyst powder must be vaporized for the reaction to occur, and the products must be cooled in an inert atmosphere. Therefore, the torch was adjusted to produce the hottest plasma, and certain experiments were run in an argon-filled container. TEM analysis of the products of these experiments showed little change in the starting material, indicating that the transfer of heat from the plasma to the powder was insufficient to vaporize the powder. This result was due to short residence times of the powder in the plasma and/or the plasma was not hot enough.
[0018] Another experiment used an experimental plasma torch that introduced the coal/catalyst powder directly into the plasma by entraining the powder in the gasses used to feed the torch. Again, it was found that short exposure time of the powder to the hot zone of the plasma was too short to cause vaporization of the fed materials and as a result no carbon nanotubes were formed.
[0019] The available plasma spray torches are designed to melt metal and ceramic powders at high feed rates and to eject the molten powders at a high speed. They are not designed to completely vaporize the powders and the high velocities cannot be reduced to increase the thermal transfer to the powder.
[0020] Independent adjustment of the parameters that control plasma temperature and residence time of the powder feed in the plasma may allow vaporization of carbon powders and therefore could produce nanotubes.
[0021] Yet another approach to create hot plasma is by high frequency induction coupling. ICP torches are used to atomize and ionize analytical samples to do electronic emission spectroscopy, mass spectral analysis, and are used in reactors to produce sub-micron sized metal powders. They can attain temperatures of well over 10,000° K, and are known to atomize materials with a high degree of efficiency and reproducibility. These qualities make ICP reactors attractive for nanotube production. Other key advantages of the ICP reactor concept are the ability to process tens of grams per minute, and the continuous nature of the feed. The ICP plasma reactor concept is being investigated for example at the Institute of Laser Plasma Physic at the Heinrich-Heine University in Dusseldorf Germany to produce nanopowders [P. Buchner, D. Lützenkirchen-Hecht, H. -H. Strehblow und J. Uhlenbusch: Production and characterization of nanosized Cu/O/SiC composite particles in a thermal rf plasma reactor, Journal of Materials Science 34 (1999), 925-931]. An inductively coupled plasma (ICP) reactor (rf generator: f=3.5 MHz, max. rf plate power 35 kw; plasma gas: argon at 400-1000 MPa) is used to produce ultrafine metal, ceramic, and composite powders (particle size ca. 10 nm) starting from metallic and ceramic precursor powders (grain size approx. 10 μnm). An attractive feature of this reactor system is the high production rate (up to 100 g/h). The inventor developed similar equipment. The ICP reactor offers high production rates with the use of powder reactants, and more importantly, with a continuous collection of product. However, it is not known whether this system can be used to vaporize solid carbon and metal particles to produce single walled nanotubes. It is known that it is possible to produce multi-walled carbon nanotubes in such system, however this product can be produced at much lower temperature than single walled nanotubes.
[0022] Y. Tanaka, Y. Matsumoto, K. Mizutani reported the production of fullerene and multi-walled carbon nanotubes [JP 2546511, October 23, 1996] using carbon powder exposed to hot plasma generated using high frequency induction coil. However, they did not produce single walled nanotubes and it is not obvious that the conditions of the hot plasma can be changed sufficiently to produce such product. They also did not vaporize catalyst in their process, and it is not obvious that conditions for the hot plasma can be achieved to vaporize metal catalyst and solid carbon simultaneously to produce sufficient clusters of carbon and nanometal catalyst to grow single walled nanotubes.
[0023] A clear understanding of the general chemical mechanism of SWNT formation however, is required in order to optimize any production scheme for SWNTs with higher yield and desirable quality of SWNTs. In particular, this includes the rationalization of the role of sulfur, oxygen and hydrogen-containing impurities in the coal-derived raw starting material. The design of new processes that offer alternatives to the arc process, viable production schemes, which would enable continuous production of SWNTs in high yields, is practically impossible without preliminary quantitative assessment of the required process parameters, largely based on this mechanistic consideration. Thus, the feasibility of SWNT synthesis in Inductively Coupled Plasma (ICP) reactors and in Plasma Torch (PT) reactors was estimated based on the knowledge of the kinetic mechanism derived in the course of parametric studies by inventors of the arc production process.
[0024] The main result revealed in the detailed parametric study of the arc process of SWNT formation is that the kinetics are very reminiscent of the kinetics of fullerene formation in the arc, which was previously studied in detail [A. V. Krestinin, A. P. Moravsky, “Mechanism of Fullerene Synthesis in the Arc Reactor” Chem. Phys. Lett. , v.286, 479-485 (1998)]. Therefore, a brief explanation of the main conclusions drawn from the mechanism of fullerene formation and from the quantitative description of the fullerene arc process is necessary, followed by consideration of the applicability of these results to SWNT arc synthesis and its quantitative analysis.
[0025] In fullerene arc synthesis the pure carbon vapor flowing from the narrow arc gap is idealized as a turbulent jet of cylindrical symmetry, which is described in the framework of a semi-empirical theory [G. N. Abramovich, Applied Gas Dynamics, Science, M., 1969] of heat and mass transfer in a free turbulent jet. These turbulent transfer phenomena entirely control the dynamics of carbon vapor mixing with helium gas and the resulting cooling. The diffusion of helium into the arc gap clearance is negligibly small under the narrow gap conditions. This turbulent jet model made it possible to find an analytical relationship between the essential parameters of the arc process. These include the rate of soot formation V soot , the original carbon vapor temperature T o and velocity U o , the helium pressure in the reactor P, the gap width h o and electrode diameter 2r o , and finally, the characteristic time for turbulent mixing and cooling of carbon vapor τ mix . The value of τ mix turns out to be uniquely linked to the value of the fullerene yield, obtained under various arc currents, helium pressures and inter-electrode gap, and thus enable prediction of the yield from the available process parameters. An optimal value for τ mix corresponds to the maximum fullerene yield, and this value must be retained constant at any variation of a parameter among those listed above, by appropriately adjusting the values of other parameters in accordance with well proven [Krestinin et. al.] relationship τ mix =r o 1.5 /U o h o =2r o 2.5 P/V soot RT. So, the rate of cooling (τ mix ) is the main and the only parameter determining the fullerene yield.
[0026] The inventors have established that the yield of SWNTs in the arc process varies with the change of helium pressure, arc current and rod feed rate in the same manner as the yield of fullerenes in the fullerene synthesis considered above. The pressure, current and feed rate dependencies of the SWNT yield all pass through a maximum, which has the same value for all three cases, thus implying existence of a unique set of parameters for optimal production of SWNTs. Therefore, it was concluded with a high degree of certainty that formation of SWNTs is a fast gas process that is kinetically governed by the same hydrodynamic factors, namely, the rate of cooling of mixed carbon/metal vapor. The same analytical approach, described above, seems applicable to mixed carbon/metal vapor condensation under arc conditions, since the metal component content in the vapor is low enough to consider its influence on gas dynamics parameters as a small perturbation.
[0027] The existence of a unique optimal set of externally controlled parameters for SWNT production in the arc, and of an analytical relationship between those parameters, means that there exists a set of internal parameters that are optimal for the process. The internal parameters include at least the process temperature, carbon and metal vapor density, the rate of vapor cooling, and can only be controlled indirectly. These factors govern the production rate of SWNTs by influencing he mechanism of mixed vapor condensation. The process can be effected at any of its kinetic stages, such as during the build up or steady state performance of metal catalyst particles during their positioning and deactivation, or during separate conversions of carbon vapor that results in soot formation, etc. Other experimental schemes that are potentially capable of intense generation of mixed carbon/metal vapor in hot plasma environment, such as ICP and PT techniques, will produce SWNTs if the values of these process governing factors are maintained the same as in the optimal arc process. In other words, it is a plausible assumption that in any hot plasma carbon/metal system, it is necessary to maintain certain temperature profile and vapor density, pertinent to optimal arc process, to eventually obtain SWNTs. This was the approach pursued by the inventors; to as closely as possible mimic the temperature and vapor density conditions found in the arc, while designing ICP and PT experimental setups intended for obtaining SWNTs on a much larger scale than the arc process.
[0028] A simple way to assess experimental conditions and geometry required for viable ICP and PT processes consists of reproducing the useful power density of the arc in the hot plasma region of ICP and PT reactors, and proportional scaling up of the amount of carbon and metal powders fed into the plasma. Assuming that all carbon and metal particulates are vaporized in the hot plasma plume or ball, the reaction zone will have the appropriate temperature and vapor density. The cooling rate can be adjusted by regulating the inert carrier gas (argon) flow rate. For example, the typical value for the useful power density of the SWNT producing arc can be estimated as ca. 2 kw/cm 3 . This value ensures complete vaporization of ca. 0.3 g of carbon and catalyst metal particles per minute. The condensation process of this initially ca 3700 K hot vapor, taking place during ca. 1 ms during fast mixing of the vapor with buffer gas yields ca. 15 mass. % of SWNTs in the condensed soot. To scale up the SWNT production rate of an ICP reactor by a factor of 10, the hot plasma ball of the ICP reactor should be ca. 10 cm 3 (10 times that of the arc hot zone) in volume. The induction coil used to generate the plasma should be capable of developing ca. 20 kw power in the argon gas at 200-700 Torr in the ICP reactor, and the carbon/metal powder feed rate should be ca. 3 grams/minute (the ICP experiments were carried out at various feed rates and 1.5 gram/minute appeared optimum). The standard LEPEL T-40 radio frequency generator can meet this power requirement, while using a 20 mm in inner diameter quartz tube for a reactor to create a plasma ball constrained within 10 cm 3 , which were the actual tube size and power levels employed by the inventor and demonstrated that the predicted yields could be obtained.
[0029] The ICP reactor and overall carbon vaporization rate can be further scaled up, in contrast to the arc process. For example, an ICP reactor employing 200 kw power in the induction coil and a flow-through tube 44 mm in inner diameter was capable of vaporizing under hot plasma conditions up to 100 g/min of pure graphite powder in a fullerene producing process, yielding ca. 6% of fullerenes in the product [Tanaka et. al.]. Up to 1 MW RF power supplies are commercially available, so potential capabilities of the ICP method for high rate SWNT production far surpass those of the arc which is presently the main process for bulk SWNT manufacturing. When combined with the possibility to use such low cost raw material as coals, the ease of scaling the ICP method makes it ideal for the development of an industrial scale SWNT production process.
[0030] Therefore, considering the foregoing, a need remains for improved methods of producing single-wall carbon nanotubes, with very high purity and homogeneity in processes with improved conversion efficiency of feedstock to single walled nanotubes (SWNT). The combination of RF hot plasma system, and the use of solid feed materials at the specific operating conditions could be a practical method to mass produce the SWNT product.
SUMMARY OF THE INVENTION
[0031] This invention relates to the method of effective mass production of single-wall carbon nanotubes of high purity, homogeneity at high yield from solid carbon materials such as coal. In the reaction of this method, single-wall carbon nanotubes are produced in a reaction zone at high temperature created by hot plasma such as RF plasma.
[0032] An ICP reactor system was designed for SWNT production from solid carbon such as coal. This system offers the advantages of powder feedstock, continuous production and high throughput. The successful design utilizes a closed system as shown in FIG. 1. The high frequency power supply was a Lepel model T-40 ( 11 ) that powered a multi-turn water-cooled induction coil ( 12 ) wrapped around a water-cooled ( 13 ) reaction tube ( 14 ). A vibratory powder feeder ( 15 ) was used to shake coal/catalyst powder into the stream of argon that was maintained at a pressure of 300 torr. The powder entered the plasma ( 16 ), was vaporized and condensed into nanotubes and other products, which were collected in the trap ( 17 ). The pressure of the reactor is maintained using vacuum pump ( 18 ). The powder feeder is installed above the reactor ( 14 ) and its operation was flawless even though ultrafine powder was used. An alternative feeding mechanism is to fluidize the powder from the bottom into the hot plasma zone as shown in the schematic in FIG. 2. In this case the pressure control ( 28 ) and product collection ( 27 ) will be from the top. This approach allows for the control of the residence time of powder feed in the hot zone.
[0033] In case of coal as source of solid carbon two Premium Coal samples selected by the present inventors for comparison were a low volatile bituminous coal (Pocahontas, Va.) and a high volatile bituminous coal (Pittsburgh, Pa.). The two coal samples were carbonized at 1000° C. for 4 hours under argon atmosphere. Commonly, the temperature was increased slowly at 5° C./minute under a slow flow of argon while pulling a light vacuum. Outgassing occurred from about 200-700° C. After most of the gasses had left the sample, a vacuum of several millitorr was applied while continuing heating at 7° C. under a slow flow of argon. Conditions of 1000° C. and millitorr vacuum were maintained for one hour. Carbonization of the high-volatile bituminous coal (Pittsburgh) produced shiny gray-black cakes with lots of voids, with a weight loss of 31.6%, which correspond closely to reported data of 37% volatile material. It appears that during heating, the high-volatile coal becomes molten, and gasses that are evolved create a brittle, sponge-like cake. Carbonization of the low volatile coal (Pocahontas) produced a more compact brick of granular, black carbon that was more friable than the high-volatile material. Weight loss was 18.2%, which compares well to reported data of 18%. The carbonized coals were ground in a mill-style laboratory grinder and sieved to 50-125 micron particle size. The carbonized coal powder was ball-milled with micron sized metal catalyst powder to produce starting materials for feed powder for plasma-based reactors or for making rods for arc discharge reactor for comparison. Choice of catalyst was made based on previous SWNT production experience of the inventors. Cobalt: nickel catalyst with a 3:1 atomic ratio was used with 2.5 atomic % metal content in the finished product (powder for plasma-based reactors, and rods for arc discharge reactor).
[0034] The arc discharge rods were made by mixing the treated coal/catalyst powder with pitch binder, then pressing 1×1×7.5 cm rods. The rods were then carbonized at 1000° C. in argon for two hours. The resultant rods had a density of approximately 1.7 g/cc, which is considered being very competitive to commercial carbon rods. The 3:1 Co:Ni metal catalyst content was 11.5 wt %, which corresponds to 2.5 atomic % metal. Similar rods were prepared from graphite/catalyst powder mixtures for comparison.
[0035] For plasma based reactor the mixture of the graphitized coal and/or graphite with the metal catalyst was used as is. This eliminates the rod fabrication step, which is expensive.
[0036] The cold plasma can easily be initiated by ionizing gas by high frequency field without powder feed. The power can then be adjusted to obtain hot plasma. When the powder is feed intense plasma is generated because of the vaporization and the ionization of the metal catalyst. The plasma then stabilizes and spreads down the tube, FIG. 1 ( 14 ). The powder feed can almost be seen by observing the higher intensity of the plasma where the powder vaporizes. This system was operated under different power conditions, pressure and with different size feed. Ultrafine solid carbon or coal (1-5 μm size) was required to vaporize all of the carbon based material in the short residence time employed in operating this reactor. The product can be collected and sampled from the filter bag or trap, FIG. 1 ( 17 ).
[0037] TEM micrographs of the collected product from ICP reactor are shown in FIG. 3. As can be seen, SWNTs were produced, and to our knowledge this is the first time that SWNTs from solid carbon or coal were produced in a plasma chemical system. Typically fine powder or multi-walled nanotubes (MWNT's) are produced in similar reactors. The intensity of the plasma, the residence time of the powder in the hot zone of the reactor chamber, the size of the powder feed, and the gas composition are all important parameters to control the type of product produced. The main effect of all these parameters is to ensure the vaporization of the carbon. Of course, if carbon in the hot zone is vaporized, the metal catalyst in the hot zone will also vaporize. The quenching rate and concentration of the vaporized product will dictate the type of nanotubes produced. In accordance with our invention, the ability to control the gas flow rate in our designed ICP system allowed us to control the concentration of metal catalyst resulted in very small and nano-size catalyst metal particles only to be formed, promoting the selective formation of only SWNTs.
[0038] Characteristics of the SWNTs were estimated from a large number of TEM images. The bundle diameters of the SWNTs produced from coal using the ICP technique were found to be about 8 nm. This bundle diameter is smaller than those obtained in the arc process (˜10 nm) and smaller than the bundle diameter obtained by Williams et al (˜13 nm) of SWNTs produced from coal in the arc process. Smaller bundles are easier to disperse. From the side-wall fringes, in the TEM micrographs, the diameter of the individual SWNT was estimated to be ˜1.25 nm. This diameter is larger than the SWNT produced by Williams et al (˜1.0 nm), but is smaller than the SWNT diameter produced in the arc process (˜1.35 nm). The catalyst metal nanoparticles, which appear as dark regions in the TEM, FIG. 2, were about the same size as the metal particles produced in the arc using graphite as the carbon precursor (average 24 nm).
[0039] None of the TEM images evaluated contained any evidence of multiwalled tubes, indicating that the nanotube product synthesized in accordance with our invention is only SWNT.
[0040] For production rate and scale up, it can be envisioned that this process is easy to scale up, being nearly continuous, and can be automated.
[0041] TEM is currently the most reliable method of analysis, since high resolution is required to discern individual nanotubes types, and to identify the bundle size and the SWNT dimension. Several analytical techniques are now available for determining the yield the SWNT. However it should be emphasized that the problem of evaluating the purity of SWNT sample is a difficult problem, and currently there is no protocol for comparison of SWNT yields in samples prepared by different techniques. This is especially true because of the inhomogenity in the samples. Two particular techniques are to some degree have been accepted by different groups working in this field. These two techniques are Raman spectroscopy and Thermogravimetric techniques. The thermogravimetric analysis (TGA) is used to decompose the sample in air, thereby selectively oxidizing the various particulate components of the soot sample. The nanotubes are more resistant to oxidation, and a weight percent measurement can be made. In addition, the amount of metal catalyst particles can also be readily analyzed from the weight of residue after the carbon materials are combusted. Raman spectroscopy gives a quantitative assessment of the types of SWNT in the sample. These analytical tools are complementary to the TEM analysis, and provide a less expensive and more rapid quantitative characterization of SWNT products. Both from TGA analysis and Aerial density measurement indicated that the yield of SWNT produced in the present system is comparable to the arc discharge method. However, the production rate is 12 times the rate of the arc process in only 20 mm diameter reactor. This result is very encouraging for further improvement and scale up.
[0042] We determined that initial problems with getting sufficiently hot plasma could be overcome by increasing the pressure of the argon atmosphere. In a preferred example, run conditions that were found to produce SWNTs were 400 torr Ar at a flow rate of 2.0 I/minute. Carbonized coal with 2-100 micron particle size was ball milled with 2.6 atomic % mixture of cobalt/nickel catalyst metals with Co:Ni ratio of 3:1 (atomic). This powder mixture was fed into the reactor (20-mm diameter) at a rate of 1.5 grams/minute. More optimization may improve nanotube yield, because the operating variables in this system are quite few and it is designed so that their optimization can potentially result in a practical and commercial method to produce large volume and low cost SWNTs. In addition, this technique takes real advantage of the low cost of powder carboneous materials like coal as the source of raw materials by using its natural powder form with simple pretreatment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] [0043]FIG. 1 shows a general schematic of RF plasma flow reactor for the production of single wall carbon nanotubes with solid gravity feed of reactant, and hot plasma zone ( 16 ) in which the solid feed is vaporized for the growth of single-wall carbon nanotubes.
[0044] [0044]FIG. 2 shows a general schematic of RF plasma flow reactor for the production of single wall carbon nanotubes with solid reactant feed from the bottom by fluidization. The high frequency power supply was a Lepel model T-40 ( 21 ) that powered a multi-turn water-cooled induction coil ( 22 ) wrapped around a water-cooled ( 23 ) reaction tube ( 24 ). A continues powder feeder ( 25 ) is used to feed the carbon/catalyst powder, that can be fluidized with a stream of inert fluidizing gas ( 29 ) such as argon. The fluidized powder ( 30 ) enters the plasma ( 26 ), was vaporized and condensed into nanotubes and other products, which were collected in the trap ( 27 ). The pressure of the reactor is maintained using vacuum pump ( 28 ). The fluidization of the powder feeder into the plasma allows for the control of the residence time powder feed in the hot zone.
[0045] [0045]FIG. 3 shows TEM micrograph of the product according to the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0046] In accordance with the present invention there is provided a novel method of producing fullerenes comprising Single Walled nanotubes (SWNT's), which comprises providing a source of carbon and a catalyst comprised essentially of a transition metal of the iron group of the periodic table of elements and sulfur in a reaction zone having a SWNT forming atmosphere comprised essentially of a plasma forming gas and subjecting the carbon and catalyst to plasma heat in the reaction zone. The heat causes the carbon and catalyst to vaporize producing a carbon and metal containing vapor that is quenched therein to condense the vapor resulting in the formation of the SWNT product outside of the heated reaction zone, where it is recovered.
[0047] In a preferred embodiment the SWNT atmosphere contains an inert gas advantageously argon or helium and optionally some hydrogen gas. The SWNT forming atmosphere is preferably maintained at a pressure in the range of 10 Torr to 760 Torr (0.013 to atmosphere).
[0048] In a preferred embodiment the metal catalyst is comprised essentially of one of iron, cobalt, or nickel powder or any mixture of these powders.
[0049] In a preferred embodiment the reaction zone is heated in an Inductively Coupled Plasma (ICP) system in a reaction chamber, wherein the SWNT atmosphere is maintained. Carbon is introduced to the plasma ball as a flow of the powder to provide more surface area and faster vaporization.
[0050] The catalyst mixture is also fed into the plasma ball preferably as a powder. The desired catalyst component ratio may be provided by supplying pure components in the desired ratio or by alloying and combining them in the desired ratio or by combining them in several convenient mixtures or alloys that when fed to the plasma ball combine to form the desired composition of SWNT forming atmosphere.
[0051] In a preferred embodiment an ICP reactor capable of developing 0.2-5 kw/cm 3 power density in plasma volume is used to vaporize carbon/metal feed powder and produce SWNTs. Preferably the power density is in the range 1-3 kw/cm 3 to ensure complete vaporization of carbon and metal powder particles in the plasma ball.
[0052] In a preferred embodiment, the linear size of carbon powder particles is in the range 1 μm -150 μm. More preferably, carbon particles are of 1-5 μm size that ensures more complete vaporization at a given plasma power density and residence time and/or allows using lower power density and shorter residence time. For the same reason it is expedient to use fine and ultrafine metal powders of the particle size 0.05-10 μm and preferably 0.5-2 μm.
[0053] In a preferred embodiment the feed rate of mixed carbon/metal powder specified for 1 kw power developed in plasma is in the range 0.01÷0.1 g/min. kw, at which rate complete vaporization of carbon is achieved depending on powder particle size and residence time of particles in the plasma zone.
[0054] In a preferred embodiment, the plasma forming gas flux is in the range of 0.01-10 l/min. cm 2 , preferably 0.1-0.5 l/min. cm 2 to ensure appropriate residence time of powder in the reaction zone and temperature profile along the reaction coordinate.
[0055] In a preferred embodiment, the pressure of the plasma forming gas lies in the range 50-760 Torr and preferably in the range 200-400 Torr to maintain the hot plasma regime of reactor operation, which ensures the vaporization of raw materials and efficient formation of SWNTs.
[0056] The following examples describe the preferred embodiments of the present invention, with description of the apparatuses, processes, procedures and results of particular and representative runs and products and comparative examples been given. The detailed description falls within the scope of, and serves to exemplify the more generally described process set forth above. The examples are presented for illustrative purposes only, and are not intended as a restriction on the scope of the invention.
EXAMPLE 1
[0057] SWNT are typically made from graphite rods that are drilled coaxially and tightly packed with a mixture of catalyst and graphite powder. Graphite rod with {fraction (5/16)}″ (8 mm) diameter was center drilled and packed with catalyst. The catalyst was 3:1 Co:Ni metal catalyst content was 11.5 wt %, which corresponds to 2.5 atomic % metal. The rods were vaporized by arcing the rods in an inert gas atmosphere using an arc reactor made of quartz chamber. From our extensive previous experience with graphite rod starting materials, the approximate conditions to produce SWNT from the catalyst-packed graphite were known. A gap is maintained by adjustment of the stepper motor speed. Pressure of helium, rod feed rate and current are maintained constant by instrument control. The voltage is allowed to vary, but remains relatively stable while equilibrium conditions of rod consumption are maintained. A single rod is consumed in about 60 minutes producing about 5 grams of products, and the products were recovered for each run. This equipment is currently the most successful for making SWNT from graphite starting materials, and is the apparatus of choice for testing SWNT production. A key feature of this Quartz Arc reactor for SWNT production is the rotating cathode. This feature was found to be critical in maximizing the yield of SWNT and smoothing the operation of the arc. SWNT gets destroyed or deteriorated if they remaining near the arc. Rotating the cathode avoids this situation. Furthermore, slag build up on the cathode with time, which results in uneven and variable gap distance with time. Again the cathode rotation maintains the slag to a minimum and as result a smooth operating condition is maintained.
[0058] The usual yield of nanotubes in the soot from these rods is on the order of 10-20 wt % nanotubes with the remainder of the product being carbon-coated catalyst metal particles that are 5-50 nm in diameter, and amorphous carbon. The key operational parameters for the graphite-catalyst powder packed graphite rods are given in Table 1.
TABLE 1 Operating Arc Discharge Parameter For Packed Graphite-Catalyst Powder Graphite Rods Packed Graphite Rods Dimensions (mm) 8 × 200 (cylindrical) Cross-section (mm 2 ) 49.5 Density (g/cc) 1.9 Current (amperes) 96 He pressure (torr) 450 Feed rate (mm/minute) 1.5 Approx. voltage 22-23
[0059] The products from the arc runs were collected and analyzed by Transmission electron microscopy (TEM). Arial measurements from TEM micrographs of the products indicate yields of about 15-18 wt % SWNT were obtained. In terms of production rate of the arc process, as pointed out, a rod can be burned in about 60 minutes, producing about 5 gm of products. The production rate in the small laboratory reactor is therefore 0.083 grams/minutes. Since there is a limitation (yield decreases with larger diameter rods) in the diameter of the rod used then scale up can be by increasing rod length, and duplicating reactors. Nevertheless these rates, while they are adequate for existing demand, are very low for practical applications.
EXAMPLE 2
[0060] Coal composite rods were made by mixing the treated coal/catalyst powder with pitch binder, then pressing 1×1×7.5 cm rods. The rods were then carbonized at 1000° C. in argon for two hours. The resultant rods had a density of approximately 1.7 g/cc, which is considered being very similar to commercial carbon rods. Cobalt: nickel catalyst with a 3:1 atomic ratio was used with 2.5 atomic % metal content in the finished rods. Coal composite rods were arced in the Quartz reactor described in example 1. The composite coal rod was installed in the lower electrode (anode), and is moved via a stepper motor to contact the broad upper electrode (cathode). A gap is maintained by adjustment of the stepper motor speed. Pressure of helium, rod feed rate and current are maintained constant by instrument control. The voltage is allowed to vary, but remains relatively stable while equilibrium conditions of rod consumption are maintained. A single rod is consumed in about 40 minutes producing about 5 grams of products.
TABLE II Operating Arc Discharge Parameter For Packed for Packed Coal-Catalyst Composite Rods. Composite rods Dimensions (mm 10 × 10 × 76 (cylindrical) Cross-section (mm ) 100 Density (g/cc) 1.7 Current (amperes) 145 He pressure (torr) 450 Feed rate (mm/minute) 2.0 Approx. voltage 22-23
[0061] The key operational difference between the graphite-catalyst powder packed graphite rods and the composite coal-catalyst rods was the rate of burn or the feed rate required maintaining the gap voltage constant. Much higher burn rate was observed for the coal-catalyst composite rods. This of course is beneficial as it increases the production throughput, provided the product is of the same quality. The products from the arc runs were collected and analyzed by Transmission electron microscopy (TEM). The coal composite rods produced an abundant amount of SWNT. Arial measurements from TEM micrographs of the two products indicate yields of about 17 wt % SWNT were obtained which is very similar to the result of example 1.
[0062] A large number of TEM images were taken and the characteristics of the SWNT were estimated. The bundle diameter of the SWNTs produced from coal and from graphite was found to be about 10 nm. The side-wall fringes are well defined in the SWNT samples produced from coal compared to those produced from graphite. There also appears to be more amorphous carbon on the SWNTs produced from graphite, which could result in the poor side-wall fringes. From the side-wall fringes the diameter of the individual SWNT was estimated to be ˜1.5 nm. This diameter is larger than the SWNTs produced by Williams et al, and again can be explained by the differences in the catalyst used in both systems. Larger diameter SWNTs could be more desirable for gas storage for example. One striking difference between the product produced from coal to that produced from graphite is the size of the metal catalyst. The metal nanoparticles, which appear as dark regions in the TEM, were almost half the size (average 12 nm) when using coal as compared to metal nanoparticles produced from graphite (average 20 nm). This is a statistically significant difference and can possibly be a result of the presence of the sulfur in coal. Small catalyst is very useful in producing smaller bundles. Small bundles are easier to disperse.
[0063] In terms of production rate of the arc process, as pointed out, a rod can be burned in about 40 minutes, using the coal composite rods, producing about 5 gm of products. The production rate is therefore 0.125 grams/minutes. While this production rate is about 50% greater than the production rate of packed graphite rods, nevertheless these rates are very low for practical applications.
EXAMPLE 3
[0064] Carbonized coal with 2-100 micron particle size was ball milled with 2.6 atomic mixture of cobalt/nickel catalyst metals with Co:Ni ratio of 3:1 (atomic). This powder mixture was fed into the reactor system described in FIG. 1., at a variable rate from 1.5 grams/minute to 3 grams/minute. In a preferred example, run conditions that were found to produce SWNTs were 400 torr pressure, at an inert gas flow rate flow rate of 2.0 l/minute of argon. The induction coil used generated plasma at about 20 kw power. The standard LEPEL T-40 radio frequency generator was used. The reactor was a 20 mm inner diameter quartz tube, the created plasma ball was constrained within 10 cm 3 , which were the actual tube size and power levels employed in the experiments that demonstrated that the predicted yields could be obtained. The optimum feed rate where all feed was vaporized within the allowed residence time and plasma power conditions was found to be 1.5 gram/minute. A large number of TEM images were taken and the characteristics of the SWNTs were estimated. The bundle diameters of the SWNTs produced from coal using the ICP technique were found to be about 8 nm. This bundle diameter is smaller than those obtained in the arc process (˜10 nm). Smaller bundles are easier to disperse. From the sidewall fringes the diameter of the individual SWNT was estimated to be ˜1.25 nm. This diameter is smaller than the SWNT diameter produced in the arc process (˜1.5 nm). The catalyst metal nanoparticles, which appear as dark regions in the TEM FIG. 2., were about the same size as the metal particles produced in the arc using graphite as the carbon precursor (average 24 nm). Arial measurements from TEM micrographs of the products indicate yields of about ca. 15 mass. % of SWNTs in the condensed soot were obtained which is very similar to the result of example 1 and example 2.. However, the production rate was up to 1.5 grams/minute, which is 12 times the rate of the arc process in only 20-mm diameter reactor with the potential of easy scaling up to a continues system.
[0065] None of the TEM images evaluated contained any evidence of multiwalled tubes, indicating that the nanotube product synthesized in accordance with our invention is pure SWNT.
[0066] While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents which are both chemically and physically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims. | Single walled carbon nanotubes are selectively produced to the substantial exclusion of multi-walled carbon nanotubes by subjecting a mixture of solid hydrocarbon, such as coal, and a transition metal catalyst, to heat generated by an RF induction system sufficient to vaporize both the solid hydrocarbon and the catalyst, and thereafter collecting the single walled carbon nanotubes thereby formed. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
None
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to jewelry, and more particularly to a jewelry made of human bone. Specifically, the preferred embodiment discloses jewelry made of pulverized and recombined primary human teeth, or baby teeth. When a parent saves the baby teeth of his/her children, the teeth would be partially or fully pulverized and bonded with a chemical bonding agent in a mold or pre-formed frame to create designs personalized to the family members.
2. Description Of Related Art
None
2. Background Information
Jewelry made from the bones and teeth of animals has been known and made and worn in early civilizations. From shark teeth to bear claws, man has adorned his body with animal tissue for both necessity and vanity since before written history. Even today, shark teeth are a popular necklace. It is believed the Vikings may have made jewelry from human teeth. It has also been known to string teeth together for attachment to a necklace. It has also been known in Costa Rica and Chile to set the solid deciduous dentition pieces in gold or silver, to make a necklace or earring.
What has not known to have been done is to manufacture jewelry from processed human deciduous dentition, as in the manner disclosed. The hardest thing in the human body is the enamel on the teeth. Like all mammals, humans have primary teeth and permanent teeth. Teeth begin being formed before birth.
Human teeth are very hard in order to withstand the grinding forces associated with chewing and crunching food. The hard material of the tooth is composed of calcium, phosphorus and other mineral salts. The material in the majority of the tooth is called dentine. The hard, shiny exterior layer is the enamel.
Teeth have two basic parts; a root to anchor the tooth to the jaw and a crown above the gum line. The root is covered with a hard material called cementum. At the center of each tooth is an area with nerves, arteries and veins called the dental pulp.
Humans have four different types of teeth, each with a different function: Incisors for cutting off bites of food; cuspids (with long sharp points) for tearing food; bicuspids (with two points) to tear and crush food; and molars with large, relatively flat surfaces to crush and grind food.
The four types of teeth together allow humans to be omnivores (eating both meat and vegetables). Most animals have more specialized teeth. Carnivorous (meat eating) animals have long sharp tearing teeth. Grazing animals, like cows and horses, have large flat teeth for grinding grass and other vegetation. Deciduous dentition is also known as the primary, baby, milk, or lacteal dentition.
The term deciduous means “to fall off.” Although deciduous teeth are in time replaced by the succedaneous, or permanent, teeth, they are very important to the proper alignment, spacing and occlusion of the permanent teeth. The deciduous incisor teeth are functional in the mouth for approximately five years, while the deciduous molars are functional for approximately nine years. They therefore have considerable functional significance. The progressive loss of deciduous teeth are considered an important milestone in the developmental phase of childhood.
The events are often marked by celebration, traditions and superstitions around the world. In the United States, tradition is based on tales of the Tooth Fairy. In Australia, mothers are once believed to have crushed their children's baby teeth and eaten the powder.
In some parts of the world, a child's baby tooth was placed in nests where rats or snakes were known to live because people believed evil witches disliked those animals and wouldn't go near them. In many parts of the world, parents placed their children's teeth in mouse nests. They thought that would result in a new tooth growing in the lost tooth's place, just as a mouse's lost teeth somehow re-grew.
In other parts of the world, mothers hid their children's teeth from animals because they believed if an animal found the tooth, a tooth like that animal's would grow in the mouth of the child.
In parts of England, mothers at one time burned their children's baby teeth so that evil witches couldn't get their hands on them and gain control of the children.
It is common for parents to save, at least for a while, the deciduous teeth of their children as a keepsake of their childhood and development. The typical storage means is a small envelope or decorative box. One disadvantage of this method of saving deciduous teeth is that the deciduous teeth are biologically contaminated. Another problem is that a small box filled with tiny teeth isn't significant as a keepsake, other than the origin of the bone matter itself.
Another disadvantage of storing deciduous teeth is that the collective individual teeth are easily lost or mixed up with the teeth of other children. Another disadvantage of storing deciduous teeth is they lack the display appeal of photographs, gifts, letters, and other memorabilia.
BRIEF SUMMARY OF THE INVENTION
The history of jewelry is as old as the history of man. Styles and trends come and go and come again. What is not found in this history is any event of persons wearing the human bone of their family members in the form of jewelry. Indeed, the notion sounds barbaric and contrary to civilized norms. However, the inventor believes that it could symbolize the ultimate commitment of love and devotion a parent can have for a child. The symbol exceeds the relevance of personal adornment, much as a Christian wearing a cross.
A primary advantage of the present invention is that it creates a new material form of jewelry. Another advantage of the present invention is that it creates a symbolic means of displaying family commitment in the form of jewelry. Another advantage of the present invention is that it provides multiple and virtually unlimited opportunities to display the symbols. Another advantage of the present invention is that it provides a value added means of keeping family baby teeth. Another advantage of the present invention is that it can be provides a novel personal material captured in a jewelry frame.
Other advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.
In the preferred embodiment of the present invention, the deciduous dentition, or primary teeth of one or more children, are provided. The dentition is pulverized into dentition particles. In an optional embodiment, the dentition particles are bleached. In an optional embodiment, the dentition particles are etched. In another optional embodiment, the dentition particles are dyed to obtain a desired color. In an optional embodiment, the dentition is pulverized further into a dentition powder.
In a preferred embodiment, a form, or mold, is provided in the design of the jewelry item desired. The dentition particles are mixed with a chemical bonding agent such as dental cement. The mixture of the dentition particles and chemical bonding agent forms a dentition matrix. The matrix is located within the form.
Optionally, an attachment may be located in the matrix to provide a means for attaching the jewelry item to an earring, necklace, bracelet, or the like. Depending on the bonding agent used, specific curing conditions may be recommended to obtain the physical properties desired in the bonded product.
In a preferred embodiment, the matrix is located in a pre-formed jewelry frame. An example of such an item would be a hollow cross. In this manner, the cured matrix would bond to the jewelry frame, securing it in place geometrically and/or materially. This method provides an interference fit potential with the frame to insure the cured matrix will not dislodge from the frame.
In another preferred embodiment, the deciduous dentition is tumbled into polished dentition particles, larger than a powder. In this embodiment, the dentition particles are mixed or coated with a chemical bonding agent. The mixture of the dentition powder and chemical bonding agent forms the dentition matrix. The matrix is located in a form or pre-formed frame for curing.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that, in some instances, various aspects of the invention may be shown exaggerated, enlarged or otherwise spatially modified to facilitate an understanding of the invention.
FIG. 1 is an illustration of an example of one embodiment flow chart of the process for making a piece of jewelry made in accordance with a preferred embodiment of the present invention.
FIG. 2 is an illustration of an example of a piece of jewelry in the shape of a cross with pulverized deciduous dentition cemented in place with composite resin.
FIG. 3 is an illustration of an example of a piece of jewelry in the shape of a heart with pulverized deciduous dentition cemented in place with composite resin.
DETAILED DESCRIPTION OF THE INVENTION
The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
Humans are diphyodont; they develop two sets of teeth during their lives. The first set of teeth are the deciduous teeth; 20 small teeth also known as baby teeth, milk teeth or primary teeth. Deciduous teeth start developing about two months after conception and typically begin to erupt above the gum line when a baby is six or seven months old. Occasionally a baby is born with one or more deciduous teeth, known as natal teeth. By the time a child is six years old, a second set of 32 larger teeth, called permanent teeth, start to erupt, or push out of the gums, eventually replacing the deciduous teeth.
FIG. 1 is a flow chart illustrating the steps of creating jewelry in accordance with a preferred embodiment of the present invention. In this Figure, it is seen that the saved dentin may be separately decontaminated and whitened in separate steps. It is also appreciated that it is possible to accomplish this in a single step by bleaching the dentition. This has the benefit a reducing the rupture strength of the dentition. It is possible to perform the disclosed steps in a different order, such as whitening after pulerverizing. It is also possible to add steps, such as for coloring the dentition.
FIG. 2 is an illustration of a piece of jewelry made in accordance with a preferred embodiment of the present invention.
FIG. 3 is an illustration of another piece of jewelry made in accordance with a preferred embodiment of the present invention.
In the preferred embodiment of the present invention, the deciduous dentition, or primary teeth of one or more children, are provided. The deciduous dentition is identified and recorded with the person from which they originated and maintained separately from the dentition of others. The dentition should be cleaned of visible blood and debris and kept hydrated in tap water or saline. Extracted teeth, including dentition, are considered biohazardous waste and must be labeled and handled accordingly.
In a preferred embodiment, the provided dentition are decontaminated. Known methods of storing and sterilizing extracted teeth include steam autoclave, freezing, gamma radiation, numerous liquid chemicals, and gaseous chemical.
In a preferred embodiment, the dentition are decontaminated by soaking in a bleach solution or by autoclaving. Bleaching decontaminates and whitens the dentition. Additionally, bleaching may soften the cementum, increasing the dentition's susceptibility to crushing.
For bleaching, the dentition may be placed in a sealed specimen container with a sufficient amount of common household bleach (5.25% or 6%), diluted to approximately 1:10 with tap water. As stated, it will be appreciated that other formulations may be used to obtain a satisfactory result. For example, 10% formalin may be used for decontamination.
Alternatively, the dentition may be heat sterilized, as by autoclaving. It is also possible to both autoclave the dentition and separately bleach it for whiteness, as illustrated in FIG. 1 .
The dentition is then partially pulverized into smaller dentition particles. In the preferred embodiment, the particle sizes obtained are between −2 and 2 on the PHI particle scale. This preferred range of particle size retains the natural appearance and recognition of the deciduous dentin, but reduces it to a size small enough to position the particles within the space of a jewelry framework for cementing. In an optional embodiment, the dentition is pulverized into a fine powder form.
The dentition may also be etched with a chemical, such as a phosphoric acid gel. The etching, if performed, roughens the surface of the particles, increasing the surface area and improving the adherence of the dental cement to the particle surfaces. Etching may be performed before or after pulverization. In another optional embodiment, the dentition particles (or powder) are dyed to obtain a desired color.
In a preferred embodiment, a form, or mold, is provided in the design of the jewelry item desired. The dentition particles are mixed with a chemical bonding agent, such as dental cement or dental composite resin. Dental composite resins are types of synthetic resins known in the dental profession as restorative materials or adhesives. These bonding agents are used for the repair of teeth and the construction of artificial teeth and are designed for attachment to tooth enamel.
The mixture of the dentition particles and the chemical bonding agent (dental composite resin) forms a dentition-adhesive matrix. The matrix is placed within the form so as to fill the void of the mold.
Optionally, a jewelry attachment may be located in the matrix to provide a means for attaching the jewelry item to an earring, necklace, bracelet, or the like. Depending on the bonding agent used, specific curing conditions may be recommended to obtain the physical properties desired in the bonded product.
Curing of resins containing a photoinitiator is accelerated by exposure to light, such as ultraviolet light. For example, bonding agents containing compounds, such as amorphous calcium phosphate (ACP) agents, are light-cured bonding adhesives. Precise curing procedures depend on the bonding agent selected.
In a preferred embodiment, the matrix is located in a pre-formed jewelry frame. An example of such an item would be the frame of a religious article, such as a cross. The frame is preferably a hollow metal structure. In this manner, the matrix would bond to the jewelry frame curing, securing it in place geometrically and/or bonding chemically. This method provides an interference fit potential with the frame to insure the cured matrix will not dislodge from the frame.
In an alternative embodiment, the dentition particles are located in the mold first, and the adhesive is then introduced into the mold to fill the voids between the pulverized dentition particles.
In another preferred embodiment, the deciduous dentition is partially crushed into a powder. In this embodiment, the dentition powder is mixed or coated with a chemical bonding agent prior to introduction into the mold. The mixture of the dentition powder and chemical bonding agent forms the dentition matrix, which is then located into a mold form or pre-formed frame for curing.
In another preferred embodiment, the deciduous dentition is tumbled into polished dentition particles, larger than a powder. In this embodiment, the dentition particles are mixed or coated with a chemical bonding agent. The mixture of the dentition powder and chemical bonding agent forms the dentition matrix. The matrix is located in a form or pre-formed frame for curing.
While this invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but, on the contrary, it is intended to cover such alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. | The invention discloses jewelry made of pulverized and recombined primary human teeth, or baby teeth. The human deciduous dentin are partially pulverized and bonded with a chemical bonding agent in a frame configured to receive the pulverized dentin mold or pre-formed frame to create designs personalized to the family members. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sports implement and more particularly to a training and protection device for use by martial arts athletes to practice kicking and punching.
2. Description of Related Art
In order to effectively develop martial arts skills it is desirable to practice with a live partner, able to anticipate and parry the kicks and punches. It is also desirable that such kicks and punches be delivered with full force and speed so as to develop the appropriate muscles and muscle co-ordination in the training athlete. Martials arts athletes have used various pads and shields held by the live partner to protect such partner and to offer a convenient target for the training athlete to strike without fear that his or her blow will hurt such partner. Such pads or shields typically are shaped as a generally rectangular, round or oval pillow having a front strike surface and equipped with straps in the back surface for holding the pad in front of one's torso. In training, the partner watches the athlete and attempts to anticipate, and thus intercept, incoming kicks or punches with the pad so as to prevent being injured by the kicks or punches.
The problem with this approach is that the partner must anticipate the direction that the blows will be delivered, i.e., to the front or to the side, and then respond quickly and accurately to parry the blows. On the other hand, the athlete who is training must be confident in the ability of the partner to respond accurately and in time to prevent injury if he or she is to strike with all available speed and force. This is particularly significant when the "attacker" wants to practice launching "double strike" techniques to different target areas, and the shield holder proves too slow to fend quick combination strikes. In actuality, the athlete holds back or restrains his blows, for fear that the partner will not accurately aim the pad to timely parry the thrust and, as a result, does not train as effectively.
U.S. Pat. No. 5,232,368 teaches an improved martial arts shield which comprises a pillow like pad with wing like attachments extending forward of the shield which fall off when stricken by the training athlete. While this shield provides the athlete with a better defined strike zone for practicing his kicking and punching, it still presents the same disadvantages of the earlier simple pad shields, in that it has to be accurately guided by the partner to intercept an incoming blow.
Thus, there still is a need for a shield to be used in martial arts training which will allow an athlete to spontaneously practice without concern for the safety of a partner and will protect a partner during such a practice without requiring the partner to exhibit a great amount of skill in intercepting incoming blows.
It is an object of the present invention to provide a training pad to be used in martial arts in which an athlete can spontaneously practice a variety of frontal and lateral blows as well as high and mid attacks, by kicking an punching, to improve his martial arts skills.
Another object of the invention is to provide a blocking shield to be used in martial arts training in which a partner holding the shield for a training athlete is adequately protected from the spontaneous blows of the athlete without needing to quickly reposition the shield on his torso to parry a variety of blows.
It is yet another object of the invention to provide a combination blocking pad and training shield for use in martial arts which is portable and easy to hold and use.
These and other objects of the present invention will be clear from the following description.
SUMMARY OF THE INVENTION
In accordance with this invention there is provided a portable combination training pad and blocking shield for use by athletes in practicing martial arts kicking and punching techniques which a partner may hold in front of his body for protection and to provide strike surfaces for an athlete to strike while practicing kicking and punching, comprising:
a resilient strike board having an outside surface against which said kicking and punching is directed, and inside surfaces opposite said outside surface having shield holding handles, wherein the improvement comprises:
the resilient board having,
a generally planar front strike surface, bound by an upper edge, a lower edge, a left edge and a right edge;
a left lateral side extending rearwardly from said left edge of said front surface, and having a left lateral strike surface; and,
a right lateral side extending from said right edge of said front surface and having a right lateral strike surface, wherein the left lateral side and the right lateral side form an angle with said front strike surface and an interior space.
In an alternate embodiment there is provided a vertical paddle extending vertically above the top end of the shield and supported in a pocket on the shield to provide a high strike target.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood from the following description thereof in connection with the accompanying drawings described as follows.
FIG. 1a is an illustrative view of an athlete kicking a front strike surface of a first embodiment of a portable combination training pad and blocking shield of the present invention which is being held by a partner.
FIG. 1b is an illustrative view of the athlete kicking a lateral side strike surface of a second embodiment of the portable combination training pad and blocking shield of the present invention which is being held by the partner.
FIG. 2 is a schematic perspective rear view of the first embodiment of the combination training pad and blocking shield showing the inside surfaces with handles and a pocket, a left lateral side, and a right lateral side.
FIG. 3 is a schematic planar front view of the combination pad and shield showing the outside surfaces for striking by the athlete.
FIG. 4 is a schematic planar view of a top side of the combination pad and shield showing a strap.
FIG. 5 is a schematic perspective rear view of the second embodiment of the combination pad and shield showing a means for absorbing shock on a top of the left and right lateral sides, and showing a means for stabilizing the shield on a bottom of the left and right lateral sides.
FIG. 6 is a schematic perspective front view of the second embodiment of the combination pad and shield showing the outside surfaces for striking by the athlete.
FIG. 7 is a schematic perspective view of the top side of the second embodiment of the combination pad and shield.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Throughout the following detailed description, similar reference characters refer to similar elements in all figures of the drawings. A training pad and blocking shield in accordance with the present invention hereinafter may be referred to simply as a shield.
Referring to FIGS. 1a and 1b, an athlete 12 training in martial arts techniques, such as kicks, is shown with a partner 14 who is holding a shield 10 in accordance with this invention. In FIG. 1a, the athlete 12 is kicking a front strike surface 16 of a first embodiment of shield 10, while the shield 10 is being held by the partner 14. In FIG. 1b, the athlete 12 is kicking a lateral side surface 18 of a second embodiment of the shield 10 while the shield 10 is being held by the partner 14. Both the first and second embodiments of the shield 10 protect the partner 14 from both frontal blows and lateral blows by the athlete 12, without the partner 14 needing to anticipate the moves of the athlete 12. In addition, the second embodiment of the shield 10 provides additional protection to the partner 14 with shock absorbing pads 20 and 74 and stabilizing pads 22 and 70 to be more fully described bellow in conjunction with the description of the second embodiment of the shield. The protection offered by the shield 10 to the partner 14 allows the athlete 12 to spontaneously practice all or essentially all martial arts techniques for kicking and striking freely without hesitancy in the action. Thus, the shield 10 of the present invention provides a combination blocking shield for the partner 14 and training pad for the athlete 12.
Referring to FIGS. 2, 3, and 4, the shield 10 of the present invention has an outside surface for kicking and punching, and an inside surface opposite the outside surface. The shield is resilient to the force of the blows of kicking and punching applied by the athlete 12. The inside surface has at least one handle 30 for the partner 14 to hold the shield 10 from a rear side 32 in place in front of his body while such blows are applied. Preferably, the shield 10 has a multiplicity of handles 30 at various locations on the inside surface 28 so that the partner 14 can select the best or most appropriate of the handles 30 to hold to assure a firm grip on the shield 10 while in place protecting his body. The shield includes a front strike section and left and right lateral strike sides. The front strike section is a resilient front strike board 24 which has a front surface 40, an upper edge 41, a bottom edge 42, a left edge 43 and a right edge 44. The front surface 40 is generally planar for striking.
A left lateral strike side 50 extends from the left edge 43 of the strike board 24 and rearwardly from the front surface 40. A right lateral strike side 52 extends from the right edge 44 of the strike board 24 and rearwardly from the front surface 40. The left lateral side 50 and the right lateral side 52, each forms an angle α with the front surface 40 of the strike board 24 to create an interior space 54. Each of the left lateral side 50 and the right lateral side 52 have a left lateral strike surface 56 and right lateral strike surface 58 respectively. Thus, the shields front strike surface 40, the left lateral strike surface 56, and the right lateral strike surface 58 are continuously available for the athlete 12 to strike while practicing, without depending upon the ability of the partner 14 to place the shield in the proper position to parry the blows.
Preferably, the rear side of the shield includes one or more straps 60 extending across the rear side of the shield 10. The straps 60 have a first end 61 secured to an exterior edge 62 of the left lateral side 50 and a second end 63 secured to an exterior edge 64 of the right lateral side 52 of the shield 10. When the shield 10 is in place in front of the partner 14, the straps 60 rest upon the torso of the partner 14, while the hands and forearms extend into the interior space 54. Thus, the straps create a resilient buffer zone which helps absorb the shock of a blow before such shock reaches the athlete.
Optionally, as shown in FIG. 3, the inside surface of the shield 10 includes a pocket 65 for holding a strike paddle 66 or other similar types of conventional martial arts striking equipment in place on the shield 10. The pocket 65 has an opening 67 located near the upper edge 41 of the front inside surface of the shield 10, so that a handle 68 of a conventional strike paddle 66 can be inserted therein. The strike paddle 66 when placed in this position on the shield 10 simulates the position of a head of an opponent and thus provides the opportunity for the athlete 12 to practice blows to the head without injuring or contacting in any way the partner 14 holding the shield 10. In this instance the straps 60 also help keep the shield holder's face at a safe distance from the paddle to prevent injury.
Referring to FIGS. 5, 6 and 7 there is shown a second, preferred, embodiment of the shield 10 which includes stabilizing pads 22 and 70 which allow the shield to rest on the body of the partner 14 and shock absorbing pads 20 and 74 which help absorb the force of the blows. Both the stabilizing pads 22 and 70 and the shock absorbing pads 20 and 74, provide additional protection to the partner 14 and also assist in properly placing and keeping the shield 10 in front of the partner's body. The stabilizing pads 22 and 70 extend rearwardly from the lateral strike sides 50 and 52 along the bottom edge 71 thereof. The stabilizing pads are preferably thicker than the strike sides and extend into the interior space 54. The stabilizing pads make the shield easier to handle and to keep in the proper position, by allowing the shield to rest on the hips or lower torso of the partner 14.
The shock absorbing pads 20 and 74, also project rearwardly and form a cushion at a top edge 75 of each of the left and right lateral sides 50, and 52. The shock absorbing pads 20 and 74 also extend into the interior space 54 from the left and right lateral sides 50, 52 and taper to conform to the lateral sides 50, 52 of the shield 10. The greater cross-sectional width of the cushion is at or near the top edge 75 of the lateral sides 50, and 52 allows the shield 10 to rest against the upper torso or shoulders of the partner 14, and thus provide a means for absorbing shock 20 of the blows applied by the athlete 12. The means for absorbing shock 20 can also stabilize the shield 10 from movement, similar to that described for the stabilizing pads 22 and 70.
Optionally, as shown in FIG. 5, the inside surface of the shield 10 again includes a pocket 65 for holding a strike paddle 66 as discussed in conjunction with the description relating to FIG. 3. It is also possible to extend the pocket to the bottom of the front strike panel as shown in FIG. 5 to form an additional holding strap 30', by leaving a portion of the pocket unattached to the interior surface so that the partner 14 can insert his hand behind the pocket and simultaneously if so desired hold the paddle handle and the shield, or just the shield.
Materials suitable for the shield 10 include any that can withstand the impact force applied by kicking and punching blows to the shield 10 and can adequately protect the person holding the shield, i.e., the partner 14. It is desirable for the material to also be light enough for the partner 14 to easily hold and support the shield 10 for periods at a time. One material which is suitable is a lightweight cellular form resulting from introduction of gas bubbles during manufacture, i.e, expanded plastic or foam, an example of which is polyurethane foam. Particularly preferred is a dual density foam which has one layer of a high density foam, e.g., a cross-linked polyurethane foam, and a second layer adjacent to the first layer which is a low density foam, e.g., a polyurethane foam. The high density foam provides a resilient surface layer for striking. The low density foam provides a soft, cushioning layer to protect the person holding the shield 10. The foam layers are secured together by conventional means, such as glue, and are oriented in the shield such that the high density foam is the outside surfaces opposite the athlete 12 and the low density foam is the inside surface facing the partner 14.
It is preferred that the foam or dual density foam of the shield 10 be covered with a protective covering material such as, for example, leather, vinyl, or heavy duty canvas. Further the outside surfaces of the shield 10 may include markings or target areas to aid the training athlete 10 in directing blows to the front, left lateral and right lateral strike surfaces of the shield.
The shield 10 is formed by any conventional means such as extrusion molding. The front strike board 24, the left lateral side 50 and the right lateral side 52 can be formed as one piece of unitary structure to provide added strength to the shield 10. Further, the shock absorbing pads and the stabilizing pads can also be formed unitary with the shield 10. Alternately, the shock absorbing pads 20 and 74 and the stabilizing pads 22 and 74, can be separately formed and securely attached to the shield 10 by conventional means. It is desirable in this alternative case to include the pads within the covering on the shield 10 thus formed so that the shock absorbing and the stabilizing pads will resist a tendency to loosen from the shield 10 with repeated use of the shield over time.
Those skilled in the art having the benefit of the teachings of the present invention as hereinabove set forth, can effect numerous modifications thereto. These modifications are to be construed as being encompassed within the scope of the present invention as set forth in the appended claims. | The invention relates to a combination training pad and blocking shield for use in martial arts training. The pad and blocking shield is portable and has frontal and side strike zones which allow an athlete training in martial arts to spontaneously practice frontal and lateral kicks and punches on the shield while such shield is held by a partner as well as mid and high level attacks techniques, without concern for the safety of the partner. | 0 |
FIELD OF THE INVENTION
[0001] This invention relates to door and wall protection structures, and, more particularly, to a corner guard for accommodating a number of different corner configurations.
BACKGROUND OF THE INVENTION
[0002] It is often desirable to provide wall and door mounted structures for protecting the door and wall from general wear and tear often associated with high traffic areas. For instance, such structures are commonly used in school, hospital, nursing home, and other such settings where there is a large amount of pedestrian traffic such that the walls and doors experience a relatively high amount of wear and tear as compared to less trafficked areas. Further, such locations commonly involve the movement of relatively large equipment in and out of hallways and doors such that the doors and walls experience further wear and tear in connection with the movement of such equipment. For example, in hospitals, patient beds, gurneys, wheel chairs, mobile imaging equipment and the like are often moved from one place to another and in doing so often unintentionally impacts the walls and doors by which they travel. Accordingly, these locations often employ wall and door guards and other such protection structures to guard against the wear and tear often associated with these uses.
[0003] One such type of wall guard is a corner guard. Corner guards are employed around the corners of walls to absorb the impact from traffic around the corners. Corners are particularly susceptible to damage from traffic traveling therearound because it is often difficult to navigate corners with large equipment and the like. Accordingly, it is increasingly common for facilities to employ the use of corner guards around corners in high traffic errors to protect the corners of the walls as well as those areas immediately adjacent. One disadvantage of known corner guards is that they are not readily adjustable to accommodate a number of different corner configurations. Thus, makers of such corner guards often have to custom make corner guards to accommodate the particular needs of the facility in which the guards are to be installed. This increases the cost associated with the production and installation of the costs and requires. The process of custom making the corner guards can take several weeks to complete and thus it is impractical to simply produce the corner guards on an as-needed basis. Thus, the makers of the corner guards must store a large number of differently configured corner guards to accommodate the needs of various customers.
[0004] It is therefore desired to provide a corner guard that does not suffer from the foregoing disadvantages. It is further desired to provide a corner guard that is relatively durable and inexpensive to manufacture.
SUMMARY OF THE INVENTION
[0005] According to one aspect of the invention, a two-piece corner guard is provided. The corner guard of the invention includes a pair of retainer wings coupled to one another by way of a durable tape or other such adhesive or fastener. The tape is provided on the back of each of the retainer wings and is relatively flexible such that the wings may be folded out to accommodate a plurality of different corner angles. A cover is configured to receive the retainers in channels defined along edges thereof to provide a relatively impact absorbent surface about the corner of the wall. In this way, the corner and surrounding wall portions are protected from impacts caused by traffic travelling around the corner.
[0006] The retainer wings preferably include a distally formed flange portion configured to cooperate with the edges of the cover and to be received in the channel thereof. In this manner, the retainer wings are selectively slidably insertable into the cover.
[0007] The retainer wings are preferably constructed from a relatively durable material adapted for coupling to a wall surface such as aluminum or another such similar material. The cover is preferably constructed from an impact resistance material such as a plastic or the like. In an embodiment of the invention, the plastic material is vinyl.
[0008] The retainer wings are preferably adjustable with respect to one another by bending the retainer wings with respect to one another. In this manner, the retainer wings are capable of selective adjustment between approximately 67 and 158 degrees. Accordingly, in construction of the corner guard of the invention, only one size retainer wing need be made to accommodate corners having a variety of configurations. Instead, after construction thereof, the retainer wings are simply bent to accommodate the desired corner angle thereby saving on manufacturing costs and providing a highly configurable corner guard capable of use in a wide number of locations.
[0009] Numerous other aspects, features and advantages of the invention will be made apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the drawings:
[0011] FIG. 1 is a partial isometric view of a corner guard of the invention attached to a corner of a wall;
[0012] FIG. 2 is an isometric view of the corner guard of FIG. 1 ;
[0013] FIG. 3 is a partial exploded view of the corner guard of FIG. 1 ;
[0014] FIG. 4 is a cross section view of the corner of the wall with the corner guard of FIG. 1 mounted thereto; and
[0015] FIG. 5 is a cross section view of the corner guard of FIG. 1 mounted to the corner of the wall.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring now to the Drawings, FIGS. 1-5 , a corner guard 10 according to the present invention is illustrated. The corner guard 10 is mounted around a corner 12 of a wall 14 . Corner guard 10 comprises a first retainer wing 16 and a second retainer wing 18 adjustably coupled to one another. The retainer wings 16 and 18 are preferably constructed from a relatively durable but pliable material such as aluminum. Other materials having similar characteristics may be used in practicing the invention as is readily understood. Wings 16 and 18 comprise identical shapes and the description of one of wings 16 and 18 is equally applicable to the other of the wings 16 and 18 . Wings 16 and 18 include a proximal end 20 and a distal end 22 in which the proximal end 20 is to be positioned at or near the corner 12 , and the distal end 22 is to be positioned opposite the corner 12 along one of the adjacent surfaces 14 a , 14 b of wall 14 . Distal ends 22 of wings 16 and 18 include a flange 24 integrally formed with wings 16 and 18 and extending horizontally away from the wall 14 to define an area of attachment for a cover 26 as will be described in detail. The remainder of wings 16 and 18 is generally planar and abuts directly against wall 14 to define a flush point of attachment about corner 12 . Wings 16 and 18 further include one or more apertures 28 through the planar surfaces of wings 16 and 18 . Apertures 28 are configured for receiving a fastener 30 such as a self-tapping screw or other similar such fastener 30 . Fasteners 30 are inserted through apertures 28 and into wall 14 for securing the wings 16 and 18 in place. A washer 32 or other spacing member may be provided between the head 34 of fastener 30 and wall 14 for preventing the head 34 of fastener 30 from directly abutting wall 14 so as to distribute the load applied to the corner guard 10 and to prevent the head from embedding into the wall 14 or pulling through the wall 14 as is readily understood.
[0017] Wings 16 and 18 are coupled to one another by way of an adhesive 36 applied to each of the back surfaces of the wings 16 and 18 . Adhesive 36 is a relatively thin layer of tape adapted to flexible couple wings 16 and 18 to one another. Adhesive 36 may comprise MP-20 pressure sensitive adhesive or a similar such adhesive. Preferably, the adhesive 36 is MACTAC Tape, and in particular, BP2003 MACTAC Tape as is generally known in the art. Adhesive 36 extends from one of wings 16 and 18 to the other of wings 16 and 18 and adheres to the adhesive 36 disposed on the other of the wings 16 and 18 . In this manner, wings 16 and 18 are flexibly coupled to one another 100 such that they may be folded to accommodate a plurality of different angles. Preferably, the wings 16 and 18 are capable of being folded with respect to one another to accommodate wall angles of between 67.5 degrees and 157.5 degrees as demonstrated by arrow 38 . Accordingly, corner guard 10 of the invention is able to accommodate a large number of different corner configurations with little adjustment thereto. In this manner, the cost of production and installation are substantially 105 decreased as compared to prior designs in which the corner guards are custom formed to accommodate a given corner angle.
[0018] Cover 26 is constructed from vinyl or a similar such material that is substantially durable and is capable of withstanding a significant amount of impact from traffic passing around corner 12 . Corner 26 comprises a unitary structure that is includes a pair of elongate segments 40 and a central segment 42 positioned between the two elongate segments 40 . Central segment 42 is rounded so as to conform to the corner 12 of wall 14 as is readily understood. Each of segments 40 includes a hooked end 44 for coupling to flange 24 of wings 16 and 18 . In this manner, cover 26 is easily secured to wings 16 and 18 for the purpose of creating a substantially durable corner guard 10 according to the invention.
[0019] A top member 46 is coupled to an upper edge of the retainer wings 16 , 18 by way of a pair of screws 48 . Top member 46 includes a pair of corresponding holes 50 through which the screws 48 are received to thereby couple the top member 46 to a pair of corresponding retainer holes 52 . Top member cooperates with cover 26 to overhand cover 26 by a predetermined amount to thereby provide a flush appearance between the corner guard 10 and wall 14 . In this manner, the 120 internal structure of corner guard 10 is not visible from the outside thereof, thereby providing an aesthetically pleasing structure while preventing the internal structure from being tampered with or otherwise affected. Top member 46 may include a pair of downwardly extending tabs 54 , which carry holes 50 thereon to facilitate coupling of the top member 46 to the retainers 16 , 18 . Tabs 54 are sized and shaped to be received between the front sides of the retainers 16 , 18 and the back side 125 of cover 26 such that the retainers 16 , 18 are slidingly received within the hooks 44 of the covers as is readily understood.
[0020] Various alternatives are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention. | A wall guard for use around wall corners is disclosed in which the wall guard includes a pair of retainers are flexibly mounted to one another. The retainers are coupled to one another by way of an adhesive tape material that extends over the back sides of the retainers. A cover is secured to the pair of retainers for absorbing impacts from passing traffic to thereby protect the corner of the wall against wear and tear. | 4 |
FIELD OF THE INVENTION
The present invention relates to the field of plastic materials. More particularly, the invention relates to the improvement of the surface properties of polypropylene.
BACKGROUND OF THE INVENTION
Polypropylene is a relatively low cost resin having many desirable properties. It is lightweight, has excellent chemical resistance, a high melting point, good stiffness to toughness balance and excellent dielectric properties. Being thermoplastic, it is readily adaptable to a wide variety of applications in food packaging, construction, electronics, fiber, recreation uses, etc. Nevertheless, it suffers from a number of drawbacks which derive from its surface and inter-surface properties, and limit its use and/or give rise to inferior products. Among its disadvantages is its difficulty in printing, painting and glueing.
Furthermore, because of the hydrophobic nature of PP, undesirable electric charges develop on its surface which limit the processing speed of filaments and fibers made therefrom. It is also difficult to metallize and its adhesion to reinforcing additives, such as glass fiber, is poor. This is particularly felt with molding resin grade, i.e. isotactic+syndiotactic, polypropylene (PP).
THE PRIOR ART
One specific example of the latter problems is in the dyeing of polypropylene fibers and textile fabrics. End-use performance has been unsatisfactory with respect to light-fastness of the dye, and its resistance to rub-off, laundering and dry-cleaning. To overcome this, it has been suggested to modify the surface of the resin by sulfonation, halogenation or phosphorylation (H. Mark, Encyclop. of Polym. Sci. and Tech., Vol. 9, p. 431). The reagents required are corrosive and make for ecological waste problems. Copolymerizations or grafting of compounds bearing dye-receptive polar groups, including acrylic esters, acrylonitrile, vinylpyridine and styrene, have been applied, but the results have not been completely successful (I. I. Rubin, ed., Handbook of Plastic Material and Technology, 1900, p. 446-447.)
Another proposed solution has been the admixing of small amounts of dye receptors, such as organometallic compounds in melt extrusion (H. Mark, ibid, Vol. 9, p. 431), but such compounds are, like those of nickel, suspect in regard to toxicity. The incorporation of pigments has also been applied, but this method is expensive, is limited in the colors which can be produced and the incorporated pigment impairs fiber properties.
In metallizing PP it is of great importance to establish a strong bond between the metal and the plastic, since their different coefficients of thermal expansion cause stress build-up and product deterioration on thermal cycling. For this purpose, it has been necessary to treat the surface by oxidation, chemical modification as described above for the fiber applications, or graft modification (H. Mark, ibid, Vol. 11, p. 616) using vinyl monomers in conjunction with peroxides. However, the latter treatment seriously deteriorates the PP (WO 92/03486).
Similarly, only partially successful methods have been applied to polypropylene surfaces for the purposes of adhesion (Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd ed., Vol. 1, p. 498). The severity of the problem in this case is shown by the application of concentrated sulfuric acid-sodium dichromate solutions. Ecological problems with respect to the latter are well documented.
Another area where the surface adhesion properties of PP require improvement is that of the reinforcement of molded products with additives such as glass fibers. The bond between the hydrophobic polymer and the inorganic surface has a significant effect on the properties of the reinforced plastic.
A method for improving the sorption capacity of hydrophobic thermoplastic polymers, including PP, as a means to improve performance in some of the above applications, has been proposed in U.S. Pat. No. 4,066,387. In that patent, bromine (or another halogen) is absorbed into the polymer and subsequently reacted therein with a pervading reagent such as NH 3 to produce a gas as one of the reaction products. Again, serious ecological problems are encountered in this approach in the disposal of NH 4 Br.
It should be noted that the above discussion applies primarily to isotactic PP. By contrast, atactic PP (APP), which is a by-product of isotactic PP of low viscosity by comparison, and ethylene copolymers with vinyl acetate (EVA) have been known for use as hot-melt sealants and adhesives (Kirk-Othmer, ibid; Vol. 20, p. 554). It has been recently proposed (U.S. Pat. No. 5,041,484) to modify APP with dibromostyrene by grafting the latter onto APP using free-radical initiators for the purpose of rendering such hot melt adhesives fire retardant (FR).
In a similar manner, it has been proposed to flame retard isotactic or syndiotactic PP by grafting ring brominated styrene monomers onto PP using free-radical initiators at elevated temperatures (WO 92/03486).
However, by grafting brominated styrene onto PP in this manner, the viscosity of the substrate is seriously decreased and other physico-mechanical properties are impaired. For instance, as will be illustrated with reference to Table I below (Formulation 7), the melt flow index is increased 14-fold, while the Izod Impact is only 7.7 J/m. WO 92/03486 also notes that physical strength properties are deteriorated by harsh conditions in the grafting process (p. 14, lines 13-16). By contrast, when the same PP is thermo-processed with ring brominated styrene monomers, as well as other aromatic ring polybrominated olefinic compounds, but in the total absence of free radical initiators, PP products are obtained which have unique surface properties, rendering them more sorptive and adhering to inorganic surfaces, and at the same time retaining considerably better physico-mechanical properties.
SUMMARY OF THE INVENTION
The method of improving the surface compatibility properties of polypropylene, according to the invention, comprises thermoprocessing at least one aromatic ring-polybrominated olefinic compound with polypropylene, in the absence of free radical initiators. In contradistinction to the prior art, no free radical initiators are used when carrying out the process of the invention.
The aromatic ring-polybrominated olefinic compound can be a compound selected from the many suitable compounds known in the art, and the skilled person will be able to select a suitable compound for this purpose. According to a preferred embodient of the invention, the said aromatic ring-polybrominated olefinic compound is selected from among dibromostyrene (DBS), tribromostyrene (TBS), pentabromobenzylomonoacrylate (PBB-MA), and their mixtures with themselves and/or with tribromophenylmaleimide (TBPMI).
According to another preferred embodiment of the invention, the surface compatibility property to be improved is the adhesion to other substances, e.g., to materials such as printing and/or painting and/or dyeing materials, glues, metals, metal coatings, glass and the like.
The invention is also directed to polypropylene compositions having improved surface compatibility properties, which compositions have been obtained by thermo-processing polypropylene together with at least one aromatic ring-polybrominated olefinic compound, in the absence of free radical initiators.
As stated, according to a preferred embodient of the invention, the aromatic ring-polybrominated olefinic compound is selected from among dibromostyrene (DBS), tribromostyrene (TBS), pentabromobenzyl-monoacrylate (PBB-MA), and their mixtures with themselves and/or with tribromophenylmaleimide (TBPMI).
Also encompassed by the invention are coated polypropylene articles, comprising a polypropylene composition of the invention, and a non-polypropylene coating material.
According to a preferred embodiment of the invention the coating material of the article is selected from among printing and/or painting and/or dyeing materials, glues, metals, metal coatings, glass, and the like.
As stated, the compositions of the invention are produced by thermoprocessing. As used herein, the term "thermo-processing" is meant to include all the conventional mixing and forming operations used in processing PP. These include, for example, injection molding, cast molding, extrusion, vacuum forming, thermo-pressing, rotational molding, thermo-blending and foam formation at elevated temperatures. These can be combined with thermo-annealing. The temperature range of the thermo-processing operation is that used in conventional PP technology. Generally, temperatures of 100° C. to 280° C. are applied.
The time of exposure of the PP/aromatic ring-brominated olefinic compound mixture in the thermo-processing operation is also that applied in conventional PP technology, i.e. as short as one minute for, e.g., extrusion, two minutes for, e.g., thermo-pressing, and four minutes for, e.g., injection molding. The maximum time of exposure to the elevated temperatures will vary from minutes to even hours, depending not only on the thermoprocessing technique employed, but also on the type of equipment used, the mass and geometry of the product being formed, and whether or not thermo-annealing is also applied.
Other components conventionally used in PP compositions may be included. These comprise fillers such as glass fibers, pigments, UV and heat stabilizers, processing aids, FRs and FR synergists, e.g., antimony trioxide, anti-oxidants and lubricants, as well as impact modifiers (e.g., EPDM, EPR etc.)
The concentration of the aromatic ring-brominated olefinic compound vis-a-vis PP can be varied over a wide range, generally from 0.1% to 50% by weight, depending upon the specific application. Preferably, 1.0% to 30% is used.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
All the above and other characteristics and advantages of the invention will be better understood through the following illustrative and non-limitative examples.
EXAMPLE 1
Preparation of Formulations
The formulations in Table I were processed in a twin screw extruder (ex Brabender, PLE 651) at a temperature of 180°-200° C. Pellets received were injection-molded in an Arburg machine Type 221-75-350 at 230° C. Specimen bars of dimensions 1/8"×1/2"×5" were thus prepared.
TABLE I______________________________________% (w/w) in FormulationComponent 1 2 3 4 5 6 7 8______________________________________PP 50112 81.6 81.8 82.9 78.6 78.8 79.9 81.2 100ex AmocoTBS 18.4 9.2 9.2 18.4 9.2 9.2 18.4 --PBB-MA -- 9.0 2.3 -- 9.0 2.3 -- --TBPMI -- -- 5.6 -- -- 5.6 -- --FR-1033Dicumyl -- -- -- -- -- 0.4 --peroxide exPolysci-ences Inc.Antimony -- -- -- 3.0 3.0 3.0 -- --Trioxideex CampinePhysicalPropertiesMFI 73.6 46.5 77.9 43.5 175 12.5230° C./2.16 kgNotched 22.7 21.7 21.6 22.3 7.7 --IzodImpact J/m______________________________________ Note: Formulation 7 exemplifies the composition of Example 4 in WO 92/03486. This can be seen to be a different material from Formulation 1.
EXAMPLE 2
Adhesion to Bronze
The specimens prepared in Example 1 were used in the adhesion test. In this test, bronze foil was cut to the dimension of 25×75×0.2 mm. Two such strips of bronze were placed one over the other with an overlapping area of 25×25 mm. Between the overlapping sections 0.1 g of the plastic formulations of Example 1 were placed. The systems were pressed in a Dake press at a temperature of 200° C. for five minutes at a pressure of 15 tons per 35/8" ram diameter. The systems were cooled, and the pressure released. Using a Zwick 1435 tensile testing machine, the adhesion between the two bronze strips, imparted by the plastic formulation, was measured. The following results were recorded:
TABLE II______________________________________ Formulation 1 2 3 4 5 6 7 8______________________________________Maximum 2.76 1.67 1.15 2.10 2.63 1.48 NoStrength of AdhesionAdhesion N/mm.sup.2______________________________________
EXAMPLE 3
Adhesion of Dye
Specimen bars of Formulations Nos. 2 and 3, as well as of pure PP 50112 ex Amoco were marked with a red felt pen (Artline 70, High Performance, Ex Shachihata, Japan). After five minutes, attempts were made to remove the markings by wiping briskly with a paper hand towel. The marking was easily removed in this manner from the bar of PP 50112, but not at all from those prepared from Formulations 2 and 3.
EXAMPLE 4
Adhesion of Gold Plating
Specimen bars of PP 50112 ex Amoco and of Formulation 3 were prepared as in Example 1 and cleaned with acetone before gold coating.
300 Å layers of gold were deposited on these bars by vapor deposition. Then, two (2.0) cm lengths were marked off on the plated surfaces and scored to penetrate the gold layer. Cellotape strips were pressed onto these 2.0 cm sections and then peeled off. Some of the gold was peeled off as well in each case.
The Cellotape strips bearing the gold thus removed were stuck onto blue lined semi-transparent millimeter graph paper. An ACS Chroma Sensor Model CS-3 Color Tester was then used to determine the relative amounts of gold adhering to the tapes in the following manner:
Six equidistant readings were recorded over the surfaces of the sections defined on the tapes. The Color Tester beam was 6 mm in diameter and the surfaces were 12×20 mm. The surface scanned was thus well represented by the six readings. Then a blank reading of the tape and graph paper alone was made, as was a maximum reading of a section of tape representing a section of PP from which essentially all the gold had been removed. By interpolation, it was seen that the bar prepared from Formulation 3 retained almost twice as much of the gold in comparison with that made from PP 50112 (36.3% vs. 19.7%).
The above examples have been given for the purpose of illustration and are not intended to constitute a limitation of the invention. From the examples given above it is easily seen that the compositions obtained according to the invention are different materials from those obtained in grafting processes involving radical initiation, and that they present substantially improved surface compatibility vis-a-vis polypropylene itself toward other substances. While the compositions and process of the invention have been described with reference to the examples and to preferred embodiments, it is clear that many different compositions can be prepared, without departing from the spirit of the invention or exceeding its scope. | A method of improving the surface compatibility properties of polypropylene comprises thermo-processing polypropylene together with at least one aromatic ring-polybrominated olefinic compound, in the absence of free radical initiators. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of copending U.S. patent application Ser. No. 10/125,751, filed Apr. 18, 2002, which is a continuation of U.S. patent application Ser. No. 09/506,548, filed Feb. 17, 2000, which is a division of U.S. patent application Ser. No. 09/334,765, filed Jun. 16, 1999, now U.S. Pat. No. 6,238,893, which is a continuation of U.S. patent application Ser. No. 08/793,170, filed Mar. 25, 1997, now U.S. Pat. No. 5,994,128, which claims priority from PCT International Patent Application PCT/NL96/00244, filed Jun. 14, 1996, which itself claims priority from European Patent Application EP 95201728.3, filed Jun. 26, 1995, and European Patent Application EP 95201611.1, filed Jun. 15, 1995, each of which is hereby incorporated herein in its entirety by this reference.
TECHINCAL FIELD
[0002] The invention relates to the field of recombinant DNA technology, more in particular to the field of gene therapy. In particular, the invention relates to gene therapy using materials derived from adenovirus, specifically human recombinant adenovirus. It especially relates to novel virus-derived vectors and novel packaging cell lines for vectors based on adenoviruses.
BACKGROUND
[0003] Gene therapy is a recently developed concept for which a wide range of applications can be and have been envisioned. In gene therapy, a molecule carrying genetic information is introduced into some or all cells of a host, as a result of which the genetic information is added to the host in a functional format.
[0004] The genetic information added may be a gene or a derivative of a gene, such as a cDNA, which encodes a protein. This is a functional format in that the protein can be expressed by the machinery of the host cell.
[0005] The genetic information can also be a sequence of nucleotides complementary to a sequence of nucleotides (either DNA or RNA) present in the host cell. This is a functional format in that the added DNA (nucleic acid) molecule or copies made thereof in situ are capable of base pairing with the complementary sequence present in the host cell.
[0006] Applications include the treatment of genetic disorders by supplementing a protein or other substance which, because of the genetic disorder, is either absent or present in insufficient amounts in the host, the treatment of tumors, and the treatment of other acquired diseases such as (auto)immune diseases, infections, etc.
[0007] As may be inferred from the above, there are basically three different approaches in gene therapy: the first directed towards compensating for a deficiency in a (mammalian) host, the second directed towards the removal or elimination of unwanted substances (organisms or cells) and the third towards application of a recombinant vaccine (against tumors or foreign microorganisms).
[0008] For the purpose of gene therapy, adenoviruses carrying deletions have been proposed as suitable vehicles for genetic information. Adenoviruses are nonenveloped DNA viruses. Gene-transfer vectors derived from adenoviruses (so-called “adenoviral vectors”) have a number of features that make them particularly useful for gene transfer for such purposes. For example, the biology of the adenovirus is characterized in detail, the adenovirus is not associated with severe human pathology, the adenovirus is extremely efficient in introducing its DNA into the host cell, the adenovirus can infect a wide variety of cells and has a broad host-range, the adenovirus can be produced in large quantities with relative ease, and the adenovirus can be rendered replication defective by deletions in the early-region 1 (“E1”) of the viral genome.
[0009] The adenovirus genome is a linear double-stranded DNA molecule of approximately 36,000 base pairs with the 55 kDa terminal protein covalently bound to the 5′ terminus of each strand. The adenoviral (“Ad”) DNA contains identical Inverted Terminal Repeats (“ITR”) of about 100 base pairs with the exact length depending on the serotype. The viral origins of replication are located within the ITRs exactly at the genome ends. DNA synthesis occurs in two stages. First, the replication proceeds by strand displacement, generating a daughter duplex molecule and a parental displaced strand. The displaced strand is single stranded and can form a so-called “panhandle” intermediate, which allows replication initiation and generation of a daughter duplex molecule. Alternatively, replication may proceed from both ends of the genome simultaneously, obviating the requirement to form the panhandle structure. The replication is summarized in FIG. 14 adapted from Lechner and Kelly (1977).
[0010] During the productive infection cycle, the viral genes are expressed in two phases: the early phase, which is the period up to viral DNA replication, and the late phase, which coincides with the initiation of viral DNA replication. During the early phase, only the early gene products, encoded by regions E1, E2, E3 and E4, are expressed, which carry out a number of functions that prepare the cell for synthesis of viral structural proteins (Berk, 1986). During the late phase, the late viral gene products are expressed in addition to the early gene products, and host cell DNA and protein synthesis are shut off. Consequently, the cell becomes dedicated to the production of viral DNA and of viral structural proteins (Tooze, 1981).
[0011] The E1 region of adenovirus is the first region of adenovirus expressed after infection of the target cell. This region consists of two transcriptional units, the E1A and E1B genes, which both are required for oncogenic transformation of primary (embryonic) rodent cultures. The main functions of the E1A gene products are 1) to induce quiescent cells to enter the cell cycle and resume cellular DNA synthesis and 2) to transcriptionally activate the E1B gene and the other early regions (E2, E3, E4). Transfection of primary cells with the E1A gene alone can induce unlimited proliferation (immortalization) but does not result in complete transformation. However, expression of E1A in most cases results in induction of programmed cell death (apoptosis) and only occasionally immortalization (Jochemsen et al., 1987). Co-expression of the E1B gene is required to prevent induction of apoptosis and for complete morphological transformation to occur. In established immortal cell lines, high level expression of E1A can cause complete transformation in the absence of E1B (Roberts et al., 1985).
[0012] The E1B encoded proteins assist E1A in redirecting the cellular functions to allow viral replication. The E1B 55 kDa and E4 33 kDa proteins, which form a complex that is essentially localized in the nucleus, function in inhibiting the synthesis of host proteins and in facilitating the expression of viral genes. Their main influence is to establish selective transport of viral mRNAs from the nucleus to the cytoplasm concomitantly with the onset of the late phase of infection. The E1B 21 kDa protein is important for correct temporal control of the productive infection cycle, thereby preventing premature death of the host cell before the virus life cycle has been completed. Mutant viruses incapable of expressing the E1B 21 kDa gene product exhibit a shortened infection cycle that is accompanied by excessive degradation of host cell chromosomal DNA (deg-phenotype) and in an enhanced cytopathic effect (cyt-phenotype) (Telling et al., 1994). The deg and cyt phenotypes are suppressed when, in addition, the E1A gene is mutated, indicating that these phenotypes are a function of E1A (White et al., 1988). Furthermore, the E1B 21 kDa protein slows down the rate by which E1A switches on the other viral genes. It is not yet known through which mechanisms E1B 21 kDa quenches these E1A-dependent functions.
[0013] Vectors derived from human adenoviruses, in which at least the E1 region has been deleted and replaced by a gene of interest, have been used extensively for gene therapy experiments in the preclinical and clinical phase.
[0014] As stated before, all adenovirus vectors currently used in gene therapy are believed to have a deletion in the E1 region, where novel genetic information can be introduced. The E1 deletion renders the recombinant virus replication defective (Stratford-Perricaudet and Perricaudet, 1991). We have demonstrated that recombinant adenoviruses are able to efficiently transfer recombinant genes to the rat liver and airway epithelium of rhesus monkeys (Bout et al., 1994b; Bout et al., 1994a). In addition, we (Vincent et al., 1996a; Vincent et al., 1996b) and others (see, e.g., Haddada et al., 1993) have observed a very efficient in vivo adenovirus mediated gene transfer to a variety of tumor cells in vitro and to solid tumors in animal models (lung tumors, glioma) and human xenografts in immunodeficient mice (lung) in vivo (reviewed by Blaese et al., 1995).
[0015] In contrast to (for instance) retroviruses, adenoviruses 1) do not integrate into the host cell genome, 2) are able to infect nondividing cells, and 3) are able to efficiently transfer recombinant genes in vivo (Brody and Crystal, 1994). Those features make adenoviruses attractive candidates for in vivo gene transfer of, for instance, suicide or cytokine genes into tumor cells.
[0016] However, a problem associated with current recombinant adenovirus technology is the possibility of unwanted generation of replication competent adenovirus (“RCA”) during the production of recombinant adenovirus (Lochmüller et al., 1994; Imler et al., 1996). This is caused by homologous recombination between overlapping sequences from the recombinant vector and the adenovirus constructs present in the complementing cell line, such as the 293 cells (Graham et al., 1977). RCA is undesirable in batches to be used in clinical trials because RCA 1) will replicate in an uncontrolled fashion, 2) can complement replication-defective recombinant adenovirus, causing uncontrolled multiplication of the recombinant adenovirus, and 3) batches containing RCA induce significant tissue damage and hence strong pathological side effects (Lochmüller et al., 1994). Therefore, batches to be used in clinical trials should be proven free of RCA (Ostrove, 1994).
[0017] It was generally thought that E1-deleted vectors would not express any other adenovirus genes. However, recently it has been demonstrated that some cell types are able to express adenovirus genes in the absence of E1 sequences. This indicates that some cell types possess the machinery to drive transcription of adenovirus genes. In particular, it was demonstrated that such cells synthesize E2A and late adenovirus proteins.
[0018] In a gene therapy setting, this means that transfer of the therapeutic recombinant gene to somatic cells not only results in expression of the therapeutic protein but may also result in the synthesis of viral proteins. Cells that express adenoviral proteins are recognized and killed by Cytotoxic T Lymphocytes, which thus 1) eradicates the transduced cells and 2) causes inflammations (Bout et al, 1994a; Engelhardt et al., 1993; Simon et al., 1993). As this adverse reaction hampers gene therapy, several solutions to this problem have been suggested, such as 1) using immunosuppressive agents after treatment, 2) retention of the adenovirus E3 region in the recombinant vector (see European patent application EP 95202213), and 3) using temperature sensitive (“ts”) mutants of human adenovirus, which have a point mutation in the E2A region rendering them temperature sensitive, as has been claimed in patent WO/28938.
[0019] However, these strategies to circumvent the immune response have their limitations. The use of ts mutant recombinant adenovirus diminishes the immune response to some extent but was less effective in preventing pathological responses in the lungs (Engelhardt et al., 1994a).
[0020] The E2A protein may induce an immune response by itself, and it plays a pivotal role in the switch to the synthesis of late adenovirus proteins. Therefore, it is attractive to make temperature sensitive recombinant human adenoviruses.
[0021] A major drawback of this system is the fact that although the E2 protein is unstable at the nonpermissive temperature, the immunogenic protein is still being synthesized. In addition, it is to be expected that the unstable protein does activate late gene expression, albeit to a low extent. ts125 mutant recombinant adenoviruses have been tested, and prolonged recombinant gene expression was reported (Yang et al., 1994b; Engelhardt et al., 1994a; Engelhardt et al., 1994b; Yang et al, 1995). However, pathology in the lungs of cotton rats was still high (Engelhardt et al., 1994a), indicating that the use of ts mutants results in only a partial improvement in recombinant adenovirus technology. Others (Fang et al., 1996) did not observe prolonged gene expression in mice and dogs using ts125 recombinant adenovirus. An additional difficulty associated with the use of ts125 mutant adenoviruses is that a high frequency of reversion is observed. These revertants are either real revertants or the result of second site mutations (Kruijer et al., 1983; Nicolas et al., 1981). Both types of revertants have an E2A protein that functions at normal temperature and, therefore, have toxicity similar to the wild-type virus.
BRIEF SUMMARY OF THE INVENTION
[0022] In one aspect of the invention, this problem in virus production is solved in that we have developed packaging cells that have no overlapping sequences with a new basic vector and thus are suited for safe large scale production of recombinant adenoviruses. One of the additional problems associated with the use of recombinant adenovirus vectors is the host-defense reaction against treatment with adenovirus.
[0023] Briefly, recombinant adenoviruses are deleted for the E1 region. The adenovirus E1 products trigger the transcription of the other early genes (E2, E3, E4), which consequently activate expression of the late virus genes.
[0024] In another aspect of the present invention, we therefore delete E2A coding sequences from the recombinant adenovirus genome and transfect these E2A sequences into the (packaging) cell lines containing E1 sequences to complement recombinant adenovirus vectors.
[0025] Major hurdles in this approach are 1) that E2A should be expressed to very high levels and 2) that E2A protein is very toxic to cells.
[0026] The current invention, in yet another aspect, therefore discloses use of the ts125 mutant E2A gene, which produces a protein that is not able to bind DNA sequences at the nonpermissive temperature. High levels of this protein may be maintained in the cells (because it is nontoxic at this temperature) until the switch to the permissive temperature is made. This can be combined with placing the mutant E2A gene under the direction of an inducible promoter, such as, for instance, tet, methallothionein, steroid inducible promoter, retinoic acid β-receptor, or other inducible systems. However, in yet another aspect of the invention, the use of an inducible promoter to control the moment of production of toxic wild-type E2A is disclosed.
[0027] Two salient additional advantages of E2A-deleted recombinant adenovirus are 1) the increased capacity to harbor heterologous sequences and 2) the permanent selection for cells that express the mutant E2A. This second advantage relates to the high frequency of reversion of ts125 mutation: when reversion occurs in a cell line harboring ts125 E2A, this will be lethal to the cell. Therefore, there is a permanent selection for those cells that express the ts125 mutant E2A protein. In addition, as we in one aspect of the invention generate E2A-deleted recombinant adenovirus, we will not have the problem of reversion in our adenoviruses.
[0028] In yet another aspect of the invention, as a further improvement, the use of nonhuman cell lines as packaging cell lines is disclosed.
[0029] For GMP production of clinical batches of recombinant viruses, it is desirable to use a cell line that has been used widely for production of other biotechnology products. Most of the latter cell lines are of monkey origin, which have been used to produce, for example, vaccines.
[0030] These cells cannot be used directly for the production of recombinant human adenovirus, as human adenovirus cannot replicate or replicates only to low levels in cells of monkey origin. A block in the switch of the early to late phase of the adenovirus lytic cycle underlies defective replication. However, host range mutations in the human adenovirus genome are described (hr400-404), which allow replication of human viruses in monkey cells. These mutations reside in the gene encoding E2A protein (Klessig and Grodzicker, 1979; Klessig et al, 1984; Rice and Klessig, 1985; Klessig et al., 1984). Moreover, mutant viruses have been described that harbor both the hr and temperature-sensitive ts125 phenotype (Brough et al., 1985; Rice and Klessig, 1985).
[0031] We therefore generate packaging cell lines of monkey origin (e.g., VERO, CV1) that harbor:
[0032] 1) E1 sequences, to allow replication of E1/E2-defective adenoviruses, and
[0033] 2) E2A sequences, containing the hr mutation and the ts125 mutation, named ts400 (Brough et al., 1985; Rice and Klessig, 1985) to prevent cell death by E2A overexpression, and/or
[0034] 3) E2A sequences, just containing the hr mutation, under the control of an inducible promoter, and/or
[0035] 4) E2A sequences, containing the hr mutation and the ts125 mutation (ts400), under the control of an inducible promoter.
[0036] Furthermore we disclose the construction of novel and improved combinations of packaging cell lines and recombinant adenovirus vectors. We provide:
[0037] 1) A novel packaging cell line derived from diploid human embryonic retinoblasts (“HER”) that harbors nt. 80-5788 of the Ad5 genome. This cell line, named 911, deposited under no. 95062101 at the ECACC™, has many characteristics that make it superior to the commonly used 293 cells (Fallaux et al., 1996);
[0038] 2) Novel packaging cell lines that express just E1A genes and not E1B genes. Established cell lines (and not human diploid cells of which 293 and 911 cells are derived) are able to express E1A to high levels without undergoing apoptotic cell death, as occurs in human diploid cells that express E1A in the absence of E1B.
[0039] Such cell lines are able to trans-complement E1B-defective recombinant adenoviruses, because viruses mutated for E1B 21 kDa protein are able to complete viral replication even faster than wild-type adenoviruses (Telling et al., 1994). The constructs are described in detail below and are graphically represented in FIGS. 1 - 5 . The constructs are transfected into the different established cell lines and are selected for high expression of E1A. This is done by operatively linking a selectable marker gene (e.g., NEO gene) directly to the E1B promoter. The E1B promoter is transcriptionally activated by the E1A gene product, and, therefore, resistance to the selective agent (e.g., G418 in the case of NEO is used as the selection marker) results in direct selection for desired expression of the E1A gene;
[0040] 3) Packaging constructs that are mutated or deleted for E1B 21 kDa, but just express the 55 kDa protein;
[0041] 4) Packaging constructs to be used for generation of complementing packaging cell lines from diploid cells (not exclusively of human origin) without the need for selection with marker genes. These cells are immortalized by expression of E1A.
[0042] However, in this particular case, expression of E1B is essential to prevent apoptosis induced by E1A proteins. Selection of E1-expressing cells is achieved by selection for focus formation (immortalization), as described for 293 cells (Graham et al., 1977) and 911 cells (Fallaux et al., 1996), that are E1-transformed human embryonic kidney (“HEK”) cells and human embryonic retinoblasts (“HER”), respectively;
[0043] 5) After transfection of HER cells with construct pIG.E1B (see FIGS. 4A and 4B), seven independent cell lines could be established. These cell lines were designated PER.C1, PER.C3, PER.C4, PER.C5, PER.C6™, PER.C8, and PER.C9. PER denotes PGK-E1-Retinoblasts. These cell lines express E1A and E1B proteins, are stable (e.g., PER.C6™ for more than 57 passages), and complement E1-defective adenovirus vectors. Yields of recombinant adenovirus obtained on PER cells are a little higher than obtained on 293 cells. One of these cell lines (PER.C6™) has been deposited at the ECACC™ under number 96022940;
[0044] 6) New adenovirus vectors with extended E1 deletions (deletion nt. 459-3510). Those viral vectors lack sequences homologous to E1 sequences in the packaging cell lines. These adenoviral vectors contain pIX promoter sequences and the pIX gene, as pIX (from its natural promoter sequences) can only be expressed from the vector and not by packaging cells (Matsui et al., 1986, Hoeben and Fallaux, personal communication; Imler et al., 1996);
[0045] 7) E2A-expressing packaging cell lines preferably based on either E1A-expressing established cell lines or E1A-E1B-expressing diploid cells (see under 2-4). Either E2A expression is under the control of an inducible promoter or the E2A ts125 mutant is driven by either an inducible or a constitutive promoter.
[0046] 8) Recombinant adenovirus vectors as described before (see 6) but carrying an additional deletion of E2A sequences;
[0047] 9) Adenovirus packaging cells from monkey origin that are able to transcomplement E1-defective recombinant adenoviruses. They are preferably co-transfected with pIG.E1A.E1B and pIG.NEO and selected for NEO resistance. Such cells E1A and E1B are able to transcomplement E1-defective recombinant human adenoviruses but will do so inefficiently because of a block of the synthesis of late adenovirus proteins in cells of monkey origin (Klessig and Grodzicker, 1979). To overcome this problem, we generate recombinant adenoviruses that harbor a host-range mutation in the E2A gene, allowing human adenoviruses to replicate in monkey cells. Such viruses are generated as described in FIG. 12, except DNA from an hr-mutant is used for homologous recombination; and
[0048] 10) Adenovirus packaging cells from monkey origin as described under 9, except that they will also be co-transfected with E2A sequences harboring the hr mutation. This allows replication of human adenoviruses lacking E1 and E2A (see under 8). E2A in these cell lines is either under the control of an inducible promoter or the tsE2A mutant is used. In the latter case, the E2A gene will thus carry both the ts mutation and the hr mutation (derived from ts40O). Replication competent human adenoviruses have been described that harbor both mutations (Brough et al., 1985; Rice and Klessig, 1985).
[0049] A further aspect of the invention provides otherwise improved adenovirus vectors, as novel strategies for generation and application of such vectors and a method for the intracellular amplification of linear DNA fragments in mammalian cells.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] The following figures and drawings may help to understand the invention:
[0051] [0051]FIG. 1 illustrates the construction of pBS.PGK.PCRI;
[0052] [0052]FIG. 2 illustrates the construction of pIG.E1A.E1B.X;
[0053] [0053]FIGS. 3A and 3B illustrate the construction of pIG.E1A.NEO;
[0054] [0054]FIGS. 4A and 4B illustrate the construction of pIG.E1A.E1B;
[0055] [0055]FIG. 5 illustrates the construction of pIG.NEO;
[0056] [0056]FIG. 6 illustrates the transformation of primary baby rat kidney (“BRK”) cells by adenovirus packaging constructs;
[0057] [0057]FIG. 7 illustrates a Western blot analysis of A549 clones transfected with pIG.E1A.NEO and HER cells transfected with pIG.E1 A.E1B (PER clones);
[0058] [0058]FIG. 8 illustrates a Southern blot analysis of 293, 911 and PER cell lines. Cellular DNA was extracted, Hind III digested, electrophoresed and transferred to Hybond N+membranes (Amersham);
[0059] [0059]FIG. 9 illustrates the transfection efficiency of PER.C3, PER.C5, PER.C6™ and 911 cells;
[0060] [0060]FIG. 10 illustrates construction of adenovirus vector pMLPI.TK. pMLPI.TK is designed to have no sequence overlap with the packaging construct pIG.E1 A.E1B;
[0061] [0061]FIGS. 11A and 11B illustrate new adenovirus packaging constructs which do not have sequence overlap with new adenovirus vectors;
[0062] [0062]FIG. 12 illustrates the generation of recombinant adenovirus IG.Ad.MLPI.TK;
[0063] [0063]FIG. 13 illustrates the adenovirus double-stranded DNA genome indicating the approximate locations of E1, E2, E3, E4, and L regions;
[0064] [0064]FIG. 14 illustrates the adenovirus genome shown in the top left with the origins of replication located within the left and right ITRs at the genome ends;
[0065] [0065]FIG. 15 illustrates a potential hairpin conformation of a single-stranded DNA molecule that contains the HP/asp sequence (SEQ ID NO:22);
[0066] [0066]FIG. 16 illustrates a diagram of pICLhac;
[0067] [0067]FIG. 17 illustrates a diagram of pICLhaw;
[0068] [0068]FIG. 18 illustrates a schematic representation of pICLI;
[0069] [0069]FIG. 19 is a diagram of pICL (SEQ ID NO:21); and
[0070] FIGS. 20 A- 20 F recite the nucleotide sequence of pICL 5620BPS DNA (circular) (SEQ ID NO:21).
DETAILED DESCRIPTION OF THE INVENTION
[0071] The so-called “minimal” adenovirus vectors according to the present invention retain at least a portion of the viral genome that is required for encapsidation of the genome into virus particles (the encapsidation signal), as well as at least one copy of at least a functional part or a derivative of the ITR, that is, DNA sequences derived from the termini of the linear adenovirus genome. The vectors according to the present invention will also contain a transgene linked to a promoter sequence to govern expression of the transgene. Packaging of the so-called minimal adenovirus vector can be achieved by coinfection with a helper virus or, alternatively, with a packaging-deficient replicating helper system, as described below.
[0072] Adenovirus-derived DNA fragments that can replicate in suitable cell lines and that may serve as a packaging-deficient replicating helper system are generated as follows. These DNA fragments retain at least a portion of the transcribed region of the “late” transcription unit of the adenovirus genome and carry deletions in at least a portion of the E1 region and deletions in at least a portion of the encapsidation signal. In addition, these DNA fragments contain at least one copy of an ITR. At one terminus of the transfected DNA molecule an ITR is located. The other end may contain an ITR or alternatively a DNA sequence that is complementary to a portion of the same strand of the DNA molecule other than the ITR. If, in the latter case, the two complementary sequences anneal, the free 3′-hydroxyl group of the 3′ terminal nucleotide of the hairpin structure can serve as a primer for DNA synthesis by cellular and/or adenovirus-encoded DNA polymerases, resulting in conversion into a double-stranded form of at least a portion of the DNA molecule. Further replication initiating at the ITR will result in a linear double-stranded DNA molecule that is flanked by two ITRs and is larger than the original transfected DNA molecule (see FIG. 13). This molecule can replicate itself in the transfected cell by virtue of the adenovirus proteins encoded by the DNA molecule and the adenoviral and cellular proteins encoded by genes in the host-cell genome. This DNA molecule cannot be encapsidated due to its large size (greater than 39,000 base pairs) or due to the absence of a functional encapsidation signal. This DNA molecule is intended to serve as a helper for the production of defective adenovirus vectors in suitable cell lines.
[0073] The invention also comprises a method for amplifying linear DNA fragments of variable size in suitable mammalian cells. These DNA fragments contain at least one copy of the ITR at one of the termini of the fragment. The other end may contain an ITR or, alternatively, a DNA sequence that is complementary to a portion of the same strand of the DNA molecule other than the ITR. If, in the latter case, the two complementary sequences anneal, the free 3′-hydroxyl group of the 3′ terminal nucleotide of the hairpin structure can serve as a primer for DNA synthesis by cellular and/or adenovirus-encoded DNA polymerases, resulting in conversion of the displaced strand into a double-stranded form of at least a portion of the DNA molecule. Further replication initiating at the ITR will result in a linear double-stranded DNA molecule that is flanked by two ITRs, which is larger than the original transfected DNA molecule. A DNA molecule that contains ITR sequences at both ends can replicate itself in transfected cells by virtue of the presence of at least the adenovirus E2 proteins (viz. the DNA-binding protein (“DBP”), the adenovirus DNA polymerase (“Ad-pol”), and the preterminal protein (“pTP”). The required proteins may be expressed from adenovirus genes on the DNA molecule itself, from adenovirus E2 genes integrated in the host-cell genome, or from a replicating helper fragment, as described above.
[0074] Several groups have shown that the presence of ITR sequences at the end of DNA molecules are sufficient to generate adenovirus minichromosomes that can replicate if the adenovirus-proteins required for replication are provided in trans, for example, by infection with a helper virus (Hu et al., 1992; Wang and Pearson, 1985; Hay et al., 1984). Hu et al (1992) observed the presence and replication of symmetrical adenovirus minichromosome-dimers after transfection of plasmids containing a single ITR. The authors were able to demonstrate that these dimeric minichromosomes arise after tail-to-tail ligation of the single ITR DNA molecules. In DNA extracted from defective adenovirus type 2 particles, dimeric molecules of various sizes have also been observed using electron-microscopy (Daniell, 1976). It was suggested that the incomplete genomes were formed by illegitimate recombination between different molecules and that variations in the position of the sequence at which the illegitimate base pairing occurred were responsible for the heterogeneous nature of the incomplete genomes. Based on this mechanism it was speculated that, in theory, defective molecules with a total length of up to two times the normal genome could be generated. Such molecules could contain duplicated sequences from either end of the genome. However, no DNA molecules larger than the full-length virus were found packaged in the defective particles (Daniell, 1976). This can be explained by the size limitations that apply to the packaging. In addition, it was observed that in the virus particles, DNA molecules with a duplicated left end predominated over those containing the right-end terminus (Daniell, 1976). This is fully explained by the presence of the encapsidation signal near that left end of the genome (Grable and Hearing, 1990; Grable and Hearing, 1992; Hearing et al., 1987).
[0075] The major problems associated with the current adenovirus-derived vectors are:
[0076] 1) The strong immunogenicity of the virus particle;
[0077] 2) The expression of adenovirus genes that reside in the adenoviral vectors, resulting in a Cytotoxic T-cell response against the transduced cells; and
[0078] 3) The low amount of heterologous sequences that can be accommodated in the current vectors (up to maximally approximately 8000 base pairs (“bp”) of heterologous DNA).
[0079] The strong immunogenicity of the adenovirus particle results in an immunological response of the host, even after a single administration of the adenoviral vector. As a result of the development of neutralizing antibodies, a subsequent administration of the virus will be less effective or even completely ineffective. However, a prolonged or persistent expression of the transferred genes will reduce the number of administrations required and may bypass the problem.
[0080] With regard to problem 2), experiments performed by Wilson and collaborators have demonstrated that after adenovirus-mediated gene transfer into immunocompetent animals, the expression of the transgene gradually decreases and disappears approximately 2-4 weeks post-infection (Yang et al. 1994a; Yang et al. , 1994b). This is caused by the development of a Cytotoxic T-Cell (“CTL”) response against the transduced cells. The CTLs were directed against adenovirus proteins expressed by the viral vectors. In the transduced cells, synthesis of the adenovirus DNA-binding protein (the E2A-gene product), penton, and fiber proteins (late-gene products) could be established. These adenovirus proteins, encoded by the viral vector, were expressed despite deletion of the E1 region. This demonstrates that deletion of the E1 region is not sufficient to completely prevent expression of the viral genes (Engelhardt et al, 1994a).
[0081] With regard to problem 3), studies by Graham and collaborators have demonstrated that adenoviruses are capable of encapsidating DNA of up to 105% of the normal genome size (Bett et al., 1993). Larger genomes tend to be unstable, resulting in loss of DNA sequences during propagation of the virus. Combining deletions in the E1 and E3 regions of the viral genomes increases the maximum size of the foreign DNA that can be encapsidated to approximately 8.3 kb. In addition, some sequences of the E4 region appear to be dispensable for virus growth (adding another 1.8 kb to the maximum encapsidation capacity). Also, the E2A region can be deleted from the vector when the E2A gene product is provided in trans in the encapsidation cell line, adding another 1.6 kb. It is, however, unlikely that the maximum capacity of foreign DNA can be significantly increased further than 12 kb.
[0082] We developed a new strategy for the generation and production of helper-free stocks of recombinant adenovirus vectors that can accommodate up to 38 kb of foreign DNA. Only two functional ITR sequences and sequences that can function as an encapsidation signal need to be part of the vector genome. Such vectors are called “minimal adenovectors.” The helper functions for the minimal adenovectors are provided in trans by encapsidation defective-replication competent DNA molecules that contain all the viral genes encoding the required gene products, with the exception of those genes that are present in the host-cell genome, or genes that reside in the vector genome.
[0083] The applications of the disclosed inventions are outlined below and will be illustrated in the experimental part, which is only intended for that purpose and should not be used to reduce the scope of the present invention as understood by those skilled in the art.
[0084] Use of the IG Packaging Constructs Diploid Cells.
[0085] The constructs, in particular pIG.E1A.E1B, will be used to transfect diploid human cells, such as HER, HEK, and Human Embryonic Lung cells (“HEL”). Transfected cells will be selected for transformed phenotype (focus formation) and tested for their ability to support propagation of E1-deleted recombinant adenovirus, such as IG.Ad.MLPI.TK. Such cell lines will be used for the generation and (large-scale) production of E1-deleted recombinant adenoviruses. Such cells, infected with recombinant adenovirus, are also intended to be used in vivo as a local producer of recombinant adenovirus, for example, for the treatment of solid tumors.
[0086] 911 cells are used for the titration, generation, and production of recombinant adenovirus vectors (Fallaux et al., 1996).
[0087] HER cells transfected with pIG.E1A.E1B have resulted in 7 independent clones (called PER cells). These clones are used for the production of E1-deleted (including non-overlapping adenovirus vectors) or E1-defective recombinant adenovirus vectors and provide the basis for introduction of, for example, E2B or E2A constructs (e.g., ts125E2A, see below), E4 etc., that will allow propagation of adenovirus vectors that have mutations in, for example, E2A or E4.
[0088] In addition, diploid cells of other species that are permissive for human adenovirus, such as the cotton rat ( Sigmodon hispidus ) (Pacini et al., 1984), Syrian hamster (Morin et a/., 1987), or chimpanzee (Levrero et al., 1991), will be immortalized with these constructs. Such cells infected with recombinant adenovirus are also intended to be used in vivo for the local production of recombinant adenovirus, for example, for the treatment of solid tumors.
[0089] Established Cells.
[0090] The constructs, in particular pIG.E1A.NEO, can be used to transfect established cells, for example, A549 (human bronchial carcinoma), KB (oral carcinoma), MRC-5 (human diploid lung cell line), or GLC cell lines (small cell lung cancer) (de Leij et al., 1985; Postmus et al., 1988) and selected for NEO resistance. Individual colonies of resistant cells are isolated and tested for their capacity to support propagation of E1-deleted recombinant adenovirus, such as IG.Ad.MLPI.TK. When propagation of E1-deleted viruses on E1A-containing cells is possible, such cells can be used for the generation and production of E1-deleted recombinant adenovirus. They can also be used for the propagation of E1A-deleted/E1B-retained recombinant adenovirus.
[0091] Established cells can also be co-transfected with pIG.E1A.E1B and pIG.NEO (or another NEO-containing expression vector). Clones resistant to G418 are tested for their ability to support propagation of E1-deleted recombinant adenovirus, such as IG.Ad.MLPI.TK, and used for the generation and production of E1-deleted recombinant adenovirus and will be applied in vivo for local production of recombinant virus, as described for the diploid cells (see previous discussion). All cell lines, including transformed diploid cell lines or NEO-resistant established lines, can be used as the basis for the generation of “next generation” packaging cell lines that support propagation of E1-defective recombinant adenoviruses and that also carry deletions in other genes, such as E2A and E4. Moreover, they will provide the basis for the generation of minimal adenovirus vectors as disclosed herein.
[0092] E2-Expressing Cell Lines
[0093] Packaging cells expressing E2A sequences are and will be used for the generation and large scale production of E2A-deleted recombinant adenovirus.
[0094] The newly generated human adenovirus packaging cell lines or cell lines derived from species permissive for human adenovirus (E2A or ts125E2A: E1A+E2A; E1A+E1B+E2A; E1A−E2A/ts125; E1A+E1B−E2A/ts125) or nonpermissive cell lines such as monkey cells (hrE2A or hr+ts125E2A; E1A+hrE2A; E1A+E1B+hrE2A; E1A+hrE2A/ts125; E1A−E1B+hrE2A/ts125) are and will be used for the generation and large scale production of E2A-deleted recombinant adenovirus vectors. In addition, they will be applied in vivo for local production of recombinant virus, as described for the diploid cells (see previous discussion).
[0095] Novel Adenovirus Vectors.
[0096] The newly developed adenovirus vectors harboring an E1 deletion of nt. 459-3510 will be used for gene transfer purposes. These vectors are also the basis for the development of further deleted adenovirus vectors that are mutated for, for example, E2A, E2B or E4. Such vectors will be generated, for example, on the newly developed packaging cell lines described above.
[0097] Minimal Adenovirus Packaging System
[0098] We disclose adenovirus packaging constructs (to be used for the packaging of minimal adenovirus vectors) which have the following characteristics:
[0099] 1) the packaging construct replicates;
[0100] 2) the packaging construct cannot be packaged because the packaging signal is deleted;
[0101] 3) the packaging construct contains an internal hairpin-forming sequence (see FIG. 15);
[0102] 4) because of the internal hairpin structure, the packaging construct is duplicated, that is, the DNA of the packaging construct becomes twice as long as it was before transfection into the packaging cell (in our sample, it duplicates from 35 kb to 70 kb). This duplication also prevents packaging. Note that this duplicated DNA molecule has ITRs at both termini (see, e.g., FIG. 13);
[0103] 5) this duplicated packaging molecule is able to replicate like a “normal adenovirus” DNA molecule;
[0104] 6) the duplication of the genome is a prerequisite for the production of sufficient levels of adenovirus proteins required to package the minimal adenovirus vector; and
[0105] 7) the packaging construct has no overlapping sequences with the minimal vector or cellular sequences that may lead to generation of RCA by homologous recombination.
[0106] This packaging system is used to produce minimal adenovirus vectors. The advantages of minimal adenovirus vectors, for example, for gene therapy of vaccination purposes, are well known (accommodation of up to 38 kb; gutting of potentially toxic and immunogenic adenovirus genes).
[0107] Adenovirus vectors containing mutations in essential genes (including minimal adenovirus vectors) can also be propagated using this system.
[0108] Use of Intracellular E2-Expressing Vectors.
[0109] Minimal adenovirus vectors are generated using the helper functions provided in trans by packaging-deficient replicating helper molecules. The adenovirus-derived ITR sequences serve as origins of DNA replication in the presence of at least the E2 gene products. When the E2 gene products are expressed from genes in the vector genome (the gene(s) must be driven by an E1-independent promoter), the vector genome can replicate in the target cells. This will allow a significantly increased number of template molecules in the target cells and, as a result, an increased expression of the genes of interest encoded by the vector. This is of particular interest for application of gene therapy in cancer treatment.
[0110] Applications of Intracellular Amplification of Linear DNA Fragments.
[0111] A similar approach could also be taken if amplification of linear DNA fragments is desired. DNA fragments of known or unknown sequence could be amplified in cells containing the E2 gene products if at least one ITR sequence is located near or at its terminus. There are no apparent constraints on the size of the fragment. Even fragments much larger than the adenovirus genome (36 kb) should be amplified using this approach. It is thus possible to clone large fragments in mammalian cells without either shuttling the fragment into bacteria (such as E. coli ) or using the polymerase chain reaction (“PCR”). At the end stage of a productive adenovirus infection, a single cell can contain over 100,000 copies of the viral genome. In the optimal situation, the linear DNA fragments can be amplified to similar levels. Thus, one should be able to extract more than 5% g of DNA fragment per 10 million cells (for a 35-kbp fragment). This system can be used to express heterologous proteins equivalent to the Simian Virus 40-based COS cell system for research or for therapeutic purposes. In addition, the system can be used to identify genes in large fragments of DNA. Random DNA fragments may be amplified (after addition of ITRs) and expressed during intracellular amplification. Election or selection of those cells with the desired phenotype can be used to enrich the fragment of interest and to isolate the gene.
[0112] Experiments
[0113] Generation of Cell Lines Able to Transcomplement E1-Defective Recombinant Adenovirus Vectors.
[0114] 911 Cell Line
[0115] We have generated a cell line that harbors E1 sequences of adenovirus type 5 (“Ad5”) able to trans-complement E1-deleted recombinant adenovirus (Fallaux et al., 1996). This cell line was obtained by transfection of diploid human embryonic retinoblasts (“HER”) with pAd5XhoIC, which contains nt. 80-5788 of Ad5. One of the resulting transformants was designated 911. This cell line has been shown to be very useful in the propagation of E1-defective recombinant adenovirus. It was found to be superior to 293 cells. Unlike 293 cells, 911 cells lack a fully transformed phenotype, which most likely is the cause of its better performance as an adenovirus packaging line:
[0116] 1) plaque assays can be performed faster (4-5 days instead of 8-14 days, as on 293),
[0117] 2) monolayers of 911 cells survive better under agar overlay, as required for plaque assays, and
[0118] 3) higher amplification of E1-deleted vectors is obtained.
[0119] In addition, unlike 293 cells that were transfected with sheared adenoviral DNA, 911 cells were transfected using a defined construct. Transfection efficiencies of 911 cells are comparable to those of 293.
[0120] New Packaging Constructs. Source of Adenovirus Sequences.
[0121] Adenovirus sequences are derived either from pAd5.SalB, containing nt. 80-9460 of human adenovirus type 5 (Bernards et al., 1983), or from wild-type Ad5 DNA. pAd5.SalB was digested with SalI and XhoI, the large fragment was relegated, and this new clone was named pAd5.X/S. The pTN construct (constructed by Dr. R. Vogels, IntroGene, Leiden, The Netherlands) was used as a source for the human PGK promoter and the NEO gene.
[0122] Human PGK Promoter and NEO R Gene.
[0123] Transcription of E1A sequences in the new packaging constructs is driven by the human PGK promoter (Michelson et al., 1983; Singer-Sam et al., 1984), derived from plasmid pTN (gift of R. Vogels), which uses pUC119 (Vieira and Messing, 1987) as a backbone. This plasmid was also used as a source for the NEO gene fused to the Hepatitis B Virus (“HBV”) poly-adenylation signal.
[0124] Fusion of PGK Promoter to E1 Genes
[0125] As shown in FIG. 1, in order to replace the E1 sequences of Ad5 (ITR, origin of replication, and packaging signal) by heterologous sequences, we have amplified E1 sequences (nt.459 to nt. 960) of Ad5 by PCR, using primers Ea-1 (SEQ ID NO: 1) and Ea-2 (SEQ ID NO:2) (see Table 1). The resulting PCR product was digested with ClaI and ligated into Bluescript (Stratagene), predigested with ClaI and EcoRV, resulting in construct pBS.PCR1.
TABLE I Primer Sequences. Name (SEQ ID NO) Sequence Function Primer Ea-1 CGTGTAGTGT ATTTATACCC PCR amplification Ad5 (SEQ ID NO:1) a G nt459 -> Primer Ea-2 TCGTCACTGG GTGGAAAGCC PCR amplification Ad5 (SEQ ID NO:2) a A nt960 <- Primer Ea-3 TACCCGCCGT CCTAAAATGG nt1284-1304 of Ad5 (SEQ ID NO:3) a C genome Primer Ea-5 TGGACTTGAG CTGTAAACGC nt1514-1533 of Ad5 (SEQ ID NO:4) a 0 genome Primer Ep-2 GCCT CCATGG AGGTCAGATG nt1721-1702 of Ad5: (SEQ ID NO:5) a T introduction of NcoI site Primer Eb-1 GCTTGAGCCC GAGACATGTC nt3269-3289 of Ad5 (SEQ ID NO:6) a genome Primer Eb-2 CCC CTCGAG C TCAATCTGTA nt3508-3496 of Ad5 (SEQ ID NO:7) a TCTT genome: introduction of XhoI site Primer SV40-1 GGG GGATCC G AACTTGTTTA Introduction BamHI site (SEQ ID NO:8) a TTGCAGC (nt2182-2199 of pMLP.TK) adaption of recombinant adenoviruses Primer SV40-2 GGG AGATCT A GACATGATAA Introduction BglII site (SEQ ID NO:9) a GATAC (nt2312-2297 of pMLP.TK) Primer Ad5-1 GGG AGATCT G TACTGAAATG Introduction of BglII (SEQ ID NO:10) a TGTGGGC site (nt2496-2514 of pMLP.TK) Primer Ad5-2 GGAGGCTGCA GTCTCCAACG Rnt2779-2756 of PMLP.TK (SEQ ID NO:11) a GCGT Primer ITR1 GGG GGATCC T CAAATCGTCA nt35737-35757 of Ad5 (SEQ ID NO:12) a CTTCCGT (introduction of BamHI site) Primer ITR2 GGGG TCTAGA CATCATCAAT nt35935-35919 of Ad5 (SEQ ID NO:13 a AATATAC (introduction of XbaI site) PCR primer PCR/MLP1 GGCGAATTCG TCGACATCAT (Ad5 nt. 10-18) (SEQ ID NO:14) b CAATAATATA CC PCT primer PCR/MLP2 GGCGAATTCG GTACCATCAT (Ad5 nt. 10-18) (SEQ ID NO:15) b CAATAATATA CC PCT primer PCR/MLP3 CTGTGTACAC CGGCGCA (Ads nt. 200-184) (SEQ ID NO: 16) b PCT primer HP/asp1 5′-GTACACTGAC CTAGTGCCGC (SEQ ID NO:17) c CCGGGCAAAG CCCGGGCGGC ACTAGGTCAG PCT primer HP/asp2 5′-GTACCTGACC TAGTGCCGCC (SEQ ID NO:18) c CGGGCTTTGC CCGGGCGGCA CTAGGTCAGT PCT primer HP/cla1 5′-GTACATTGAC CTAGTGCCGC (SEQ ID NO:19) d CCGGGCAAAG CCCGGGCGGC ACTAGGTCAA TCGAT PCT primer HP/cla2 5′-GTACATCGAT TGACCTAGTG (SEQ ID NO:20) d CCGCCCGGGC TTTGCCCGGG CGGCACTAGG TCAAT
[0126] Vector pTN was digested with restriction enzymes EcoRI (partially) and ScaI, and the DNA fragment containing the PGK promoter sequences was ligated into PBS.PCRI digested with ScaI and EcoRi. The resulting construct pBS.PGK.PCR1 contains the human PGK promoter operatively linked to Ad5 E1 sequences from nt. 459 to nt. 916.
[0127] Construction of pIG.E1A.E1B.X
[0128] As shown in FIG. 2, pIG.E1A.E1B.X was made by replacing the ScaI-BspEI fragment of pAT.X/S by the corresponding fragment from pBS.PGK.PCR1 (containing the PGK promoter linked to E1A sequences). pIG.E1A.E1B.X contains the E1A and E1B coding sequences under the direction of the PGK promoter. As Ad5 sequences from nt. 459 to nt. 5788 are present in this construct, pIX protein of adenovirus is also encoded by this plasmid.
[0129] Construction of pIG.E1A.NEO
[0130] As shown in FIG. 3A, in order to introduce the complete E1B promoter and to fuse this promoter in such a way that the AUG codon of E1B 21 kDa functions exactly as the AUG codon of NEOR, we amplified the E1B promoter using primers Ea-3 (SEQ ID NO:3) and Ep-2 (SEQ ID NO:5), where primer Ep-2 (SEQ ID NO:5) introduces an NcoI site in the PCR fragment. The resulting PCR fragment, named PCRII, was digested with HpaI and NcoI and ligated into pAT-X/S, which was predigested with HpaI and with NcoI. The resulting plasmid was designated pAT.X/S.PCR2. The NcoI-StuI fragment of pTN, containing the NEO gene and part of the HBV polyadenylation signal, was cloned into pAT.X/S.PCR2 (digested with NcoI and NruI). The resulting construct: pAT.PCR2.NEO.
[0131] As shown in FIG. 3B, the polyadenylation signal was completed by replacing the ScaI-SalI fragment of pAT-PCR2-NEO with the corresponding fragment of pTN (resulting in pAT.PCR2.NEO.p(A)). The ScaI-XbaI of pAT.PCR2.NEO.p (A) was replaced by the corresponding fragment of pIG.E1A.E1B.X, containing the PGK promoter linked to E1A genes. The resulting construct was named pIG.E1A.NEO, and thus contains Ad5 E1 sequences (nt. 459 to nt. 1713) under the control of the human PGK promoter.
[0132] Construction of pIG.E1A.E1B
[0133] As shown in FIGS. 4A and 4B, pIG.E1A.E1B was made by amplifying the sequences encoding the N-terminal amino acids of E1B 55 kDa using primers Eb-1 (SEQ ID NO:6) and Eb-2 (SEQ ID NO:7) (introduces an XhoI site). The resulting PCR fragment was digested with BglII and cloned into BglII/NruI of pAT-X/S, thereby obtaining pAT.PCR3.
[0134] pIG.E1A.E1B was constructed by introducing the HBV poly(A) sequences of pIG.E1A.NEO downstream of E1B sequences of pAT.PCR3 by exchange of the XbaI-SalI fragment of pIG.E1A.NEO and the XbaI XhoI fragment of pAT.PCR3.
[0135] pIG.E1A.E1B contains nt. 459 to nt. 3510 of Ad5, which encode the E1A and E1B proteins. The E1B sequences are terminated at the splice acceptor at nt. 3511. No pIX sequences are present in this construct.
[0136] Construction of pIG.NEO
[0137] As shown in FIG. 5, pIG.NEO was generated by cloning the HpaI-ScaI fragment of pIG.E1A.NEO, containing the NEO gene under the control of the Ad.5 E1B promoter, into pBS digested with EcoRV and ScaI.
[0138] This construct is of use when established cells are transfected with E1A.E1B constructs and NEO selection is required. Because NEO expression is directed by the E1B promoter, NEO resistant cells are expected to co-express E1A, which is also advantageous for maintaining high levels of expression of E1A during long-term culture of the cells.
[0139] Testing of Constructs
[0140] The integrity of the constructs pIG.E1A.NEO, pIG.E1A.E1B.X and pIG.E1A.E1B was assessed by restriction enzyme mapping; furthermore, parts of the constructs that were obtained by PCR analysis were confirmed by sequence analysis. No changes in the nucleotide sequence were found.
[0141] The constructs were transfected into primary Baby Rat Kidney (“BRK”) cells and tested for their ability to immortalize (pIG.E1A.NEC) or fully transform (pAd5.XhoIC, pIG.E1A.E1B.X, and pIG.E1A.E1B) these cells.
[0142] Kidneys of 6-day old WAG-Rij rats were isolated, homogenized, and trypsinized. Subconfluent dishes (diameter 5 cm) of the BRK cell cultures were transfected with 1 or 5 82 g of pIG.NEO, pIG.E1A.NEO, pIG.E1A.E1B, pIG.E1A.E1B.X, pAd5XhoIC, or pIG.E1A.NEO together with PDC26 (Van der Elsen et al., 1983), carrying the Ad5.E1B gene under control of the SV40 early promoter. Three weeks post-transfection, when foci were visible, the dishes were fixed, Giemsa stained, and the foci counted.
[0143] An overview of the generated adenovirus packaging constructs and their ability to transform BRK is presented in FIG. 6. The results indicate that the constructs pIG.E1A.E1B and pIG.E1A.E1B.X are able to transform BRK cells in a dose-dependent manner. The efficiency of transformation is similar for both constructs and is comparable to what was found with the construct that was used to make 911 cells, namely pAd5. XhoIC.
[0144] As expected, pIG.E1A.NEO was hardly able to immortalize BRK. However, co-transfection of an E1 B expression construct (PDC26) did result in a significant increase in the number of transformants (18 versus 1), indicating that E1A encoded by pIG.E1A.NEO is functional. We conclude, therefore, that the newly generated packaging constructs are suited for the generation of new adenovirus packaging lines.
[0145] Generation of Cell Lines with New Packaging Constructs, Cell Lines, and Cell Culture
[0146] Human A549 bronchial carcinoma cells (Shapiro et al., 1978), human embryonic retinoblasts (“HER”), Ad5-E1-transformed human embryonic kidney (“HEK”) cells (293; Graham et al., 1977), and Ad5-transformed HER cells (911; Fallaux et al, 1996)) and PER cells were grown in Dulbecco's Modified Eagle Medium (“DMEM”) supplemented with 10% Fetal Calf Serum (“FCS”) and antibiotics in a 5% CO 2 atmosphere at 37° C. Cell culture media, reagents, and sera were purchased from Gibco Laboratories (Grand Island, N.Y.). Culture plastics were purchased from Greiner (Nurtingen, Germany) and Coming (Corning, N.Y.).
[0147] Viruses and Virus Techniques
[0148] The construction of adenoviral vectors IG.Ad.MLP.nls.lacZ, IG.Ad.MLP.luc, IG.Ad.MLP.TK, and IG.Ad.CMV.TK is described in detail in European patent application EP 95202213. The recombinant adenoviral vector IG.Ad.MLP.nls.lacZ contains the E. coli lacZ gene, encoding β-galactosidase, under control of the Ad2 major late promoter (“MLP”). IG.Ad.MLP.luc contains the firefly luciferase gene driven by the Ad2 MLP. Adenoviral vectors IG.Ad.MLP.TK and IG.Ad.CMV.TR contain the Herpes Simplex Virus thymidine kinase (“TK”) gene under the control of the Ad2 MLP and the Cytomegalovirus (“CMV”) enhancer/promoter, respectively.
[0149] Transfections
[0150] All transfections were performed by calcium-phosphate precipitation DNA (Graham and Van der Eb, 1973) with the GIBCO Calcium Phosphate Transfection System (GIBCO BRL Life Technologies Inc., Gaithersburg, Md., USA), according to the manufacturer's protocol.
[0151] Western Blotting
[0152] Subconfluent cultures of exponentially growing 293, 911 and Ad5-E1-transformed A549 and PER cells were washed with PBS and scraped in Fos-RIPA buffer (10 mM Tris (pH 7.5), 150 mM NaCl, 1% NP4O, 1% sodium dodecyl sulphate (“SDS”), 1% NA-DOC, 0.5 mM phenyl methyl sulphonyl fluoride (“PMSF”), 0.5 mM trypsin inhibitor, 50 mM NaF and 1 mM sodium vanadate). After 10 minutes at room temperature, lysates were cleared by centrifugation. Protein concentrations were measured with the Biorad protein assay kit, and 25 μg total cellular protein was loaded on a 12.5% SDS-PAA gel. After electrophoresis, proteins were transferred to nitrocellulose (1 hour at 300 mA). Prestained standards (Sigma, USA) were run in parallel. Filters were blocked with 1% bovine serum albumin (“BSA”) in TBST (10 mM Tris, pH 8.15 mM NaCl, and 0.05% TWEEN™-20) for 1 hour. The first antibodies were the mouse monoclonal anti-Ad5-E1B-55-kDa antibody A/LC6 (Zantema et al., unpublished) and the rat monoclonal anti-Ad5-E1B-221-kDa antibody ClGl1 (Zantema et al., 1985). The second antibody was a horseradish peroxidase-labeled goat anti-mouse antibody (Promega). Signals were visualized by enhanced chemiluminescence (Amersham Corp, UK).
[0153] Southern Blot Analysis
[0154] High molecular weight DNA was isolated and 10 μg was digested to completion and fractionated on a 0.7% agarose gel. Southern blot transfer to Hybond N+(Amersham, UK) was performed with a 0.4 M NaOH, 0.6 M NaCl transfer solution (Church and Gilbert, 1984). Hybridization was performed with a 2463-nt SspI-HindIII fragment from pAd5.SalB (Bernards et al., 1983). This fragment consists of Ad5 bp. 342-2805. The fragment was radiolabeled with α- 32p -dCTP with the use of random hexanucleotide primers and Klenow DNA polymerase. The Southern blots were exposed to a Kodak XAR-5 film at −80° C. and to a Phospho-Imager screen that was analyzed by B&L Systems' Molecular Dynamics software.
[0155] A549
[0156] Ad5-E1-transformed A549 human bronchial carcinoma cell lines were generated by transfection with pIG.E1A.NEO and selection for G418 resistance. Thirty-one G418 resistant clones were established. Co-transfection of pIG.E1A.E1B with pIG.NEO yielded seven G418 resistant cell lines.
[0157] PER
[0158] Ad5-E1-transformed HER cells were generated by transfection of primary HER cells with plasmid pIG.E1A.E1B. Transformed cell lines were established from well-separated foci. We were able to establish seven clonal cell lines, which we called PER.C1, PER.C3, PER.C4, PER.C5, PER.C6™, PER.C8, and PER.C9. One of the PER clones, namely PER.C6™, has been deposited under the Budapest Treaty under number ECACC™ 96022940 with the Centre for Applied Microbiology and Research of Porton Down, UK, on Feb. 29, 1996. In addition, PER.C6™ is commercially available from IngroGene, B.V., Leiden, NL.
[0159] Expression of Ad5 E1A and E1B Genes in Transformed A549 and PER Cells
[0160] Expression of the Ad5 E1A and the 55 kDa and 21 kDa E1B proteins in the established A549 and PER cells was studied by means of Western blotting with the use of monoclonal antibodies (“Mab”). Mab M73 recognizes the E1A products, whereas Mabs AIC6 and ClGl1 are directed against the 55 kDa and 21 kDa E1B proteins, respectively.
[0161] The antibodies did not recognize proteins in extracts from the parental A549 or the primary HER cells (data not shown). None of the A549 clones that were generated by co-transfection of pIG.NEO and pIG.E1A.E1B expressed detectable levels of E1A or E1B proteins (not shown). Some of the A549 clones that were generated by transfection with pIG.E1A.NEO expressed the Ad5 E1A proteins (see FIG. 7), but the levels were much lower than those detected in protein lysates from 293 cells. The steady-state E1A levels detected in protein extracts from PER cells were much higher than those detected in extracts from A549-derived cells. All PER cell lines expressed similar levels of E1A proteins (FIG. 7). The expression of the E1B proteins, particularly in the case of E1B 55 kDa, was more variable. Compared to 911 and 293, the majority of the PER clones express high levels of E1B 55 kDa and 21 kDa. The steady-state level of E1B 21 kDa was the highest in PER.C3. None of the PER clones lost expression of the Ad5 E1 genes upon serial passage of the cells (not shown). We found that the level of E1 expression in PER cells remained stable for at least 100 population doublings. We decided to characterize the PER clones in more detail.
[0162] Southern Analysis of PER Clones
[0163] To study the arrangement of the Ad5-E1 encoding sequences in the PER clones, we performed Southern analyses. Cellular DNA was extracted from all PER clones and from 293 and 911 cells. The DNA was digested with HindIII, which cuts once in the Ad5 E1 region. Southern hybridization on HindIII-digested DNA, using a radiolabeled Ad5-E1-specific probe, revealed the presence of several integrated copies of pIG.E1A.E1B in the genome of the PER clones. FIG. 8 shows the distribution pattern of E1 sequences in the high molecular weight DNA of the different PER cell lines. The copies are concentrated in a single band, which suggests that they are integrated as tandem repeats. In the case of PER.C3, C5, C6, and C9, we found additional hybridizing bands of low molecular weight that indicate the presence of truncated copies of pIG.E1A.E1B. The number of copies was determined with the use of a Phospho-Imager. We estimated that PER.C1, C3, C4, C5, C6, C8, and C9 contain 2, 88, 5, 4, 5, 5, and 3 copies of the Ad5 E1 coding region, respectively, and that 911 and 293 cells contain 1 and 4 copies of the Ad5 E1 sequences, respectively.
[0164] Transfection Efficiency
[0165] Recombinant adenovectors are generated by co-transfection of adaptor plasmids and the large ClaI fragment of Ad5 into 293 cells (see European patent application EP 95202213). The recombinant virus DNA is formed by homologous recombination between the homologous viral sequences that are present in the plasmid and the adenovirus DNA. The efficacy of this method, as well as that of alternative strategies, is highly dependent on the transfectability of the helper cells. Therefore, we compared the transfection efficiencies of some of the PER clones with 911 cells, using the E. coli β-galactosidase-encoding lacZ gene as a reporter (see FIG. 9).
[0166] Production of Recombinant Adenovirus
[0167] Yields of recombinant adenovirus obtained after inoculation of 293, 911, PER.C3, PER.C5, and PER.C6™ with different adenovirus vectors are presented in Table II. The results indicate that the yields obtained on PER cells are at least as high as those obtained on the existing cell lines. In addition, the yields of the novel adenovirus vector IG.Ad.MLPI.TK are similar or higher than the yields obtained for the other viral vectors on all cell lines tested.
TABLE II IG. Ad. IG. Ad. IG. Ad. Passage CMV. CMV. MLPI. Producer Cell number lacZ TK TK d1313 Mean 293 6.0 5.8 24 34 17.5 911 8 14 34 180 59.5 PER. C3 17 8 11 44 40 25.8 PER. C5 15 6 17 36 200 64.7 PER. C6 ™ 36 10 22 58 320 102
[0168] Table II. Yields of different recombinant adenoviruses obtained after inoculation of adenovirus E1 packaging cell lines 293, 911, PER.C3, PER.C5, and PER.C6™. The yields are the mean of two different experiments. IG.Ad.CMV.lacZ and IG.Ad.CMV.TK are described in European patent application EP 95202213. The construction of IG.Ad.MLPI.TK is described in this patent application. Yields of virus per T80 flask were determined by plaque assay on 911 cells, as described [Fallaux, 1996 #1493].
[0169] Generation of New Adenovirus Vectors
[0170] The used recombinant adenovirus vectors (see European patent application EP 95202213) are deleted for E1 sequences from nt. 459 to nt. 3328.
[0171] As construct pE1A.E1B contains Ad5 sequences nt. 459 to nt. 3510, there is a sequence overlap of 183 nt. between E1B sequences in the packaging construct pIG.E1A.E1B and recombinant adenoviruses, such as, for example, IG.Ad.MLP.TK. The overlapping sequences were deleted from the new adenovirus vectors. In addition, noncoding sequences derived from lacZ, which are present in the original constructs, were deleted as well. This was achieved (see FIG. 10) by PCR amplification of the SV40 poly(A) sequences from pMLP.TK using primers SV40-1 (SEQ ID NO:8) (introduces a BamHI site) and SV40-2 (SEQ ID NO:9) (introduces a BglII site). In addition, Ad5 sequences present in this construct were amplified from nt. 2496 (Ad5-1 (SEQ ID NO:10), introduces a BglII site) to nt. 2779 (Ad5-2 (SEQ ID NO:11)). Both PCR fragments were digested with BglII and were ligated. The ligation product was PCR amplified using primers SV40-1 (SEQ ID NO:8) and Ad5-2 (SEQ ID NO:11). The PCR product obtained was cut with BamHI and AflII and was ligated into pMLP.TK predigested with the same enzymes. The resulting construct, named pMLPI.TK, contains a deletion in adenovirus E1 sequences from nt. 459 to nt. 3510.
[0172] Packaging System
[0173] The combination of the new packaging construct pIG.E1A.E1B and the recombinant adenovirus pMLPI.TK, which do not have any sequence overlap, are presented in FIGS. 11A and 11B. In these figures, the original situation is also presented with the sequence overlap indicated.
[0174] The absence of overlapping sequences between pIG.E1A.E1B and pMLPI.TK (FIG. 11A) excludes the possibility of homologous recombination between packaging construct and recombinant virus, and is therefore a significant improvement for production of recombinant adenovirus as compared to the original situation.
[0175] In FIG. 11B, the situation is depicted for pIG.E1A.NEO and IG.Ad.MLPI.TK. pIG.E1A.NEO, when transfected into established cells, is expected to be sufficient to support propagation of E1-deleted recombinant adenovirus. This combination does not have any sequence overlap, preventing generation of RCA by homologous recombination. In addition, this convenient packaging system allows the propagation of recombinant adenoviruses that are deleted just for E1A sequences and not for E1B sequences. Recombinant adenoviruses expressing E1B in the absence of E1A are attractive, as the E1B protein, in particular E1B 19 kDa, is able to prevent infected human cells from lysis by Tumor Necrosis Factor (“TNF”) (Gooding et al., 1991).
[0176] Generation of Recombinant Adenovirus Derived from pMLPI.TK.
[0177] Recombinant adenovirus was generated by co-transfection of 293 cells with SalI linearized pMLPI.TK DNA and ClaI linearized Ad5 wt DNA. The procedure is schematically represented in FIG. 12.
[0178] Outline of the Strategy to Generate Packaging Systems for Minimal Adenovirus Vector
[0179] Name convention of the plasmids used:
[0180] p plasmid
[0181] I ITR (Adenovirus Inverted Terminal Repeat)
[0182] C CMV Enhancer/Promoter Combination
[0183] L Firefly Luciferase Coding Sequence hac,haw Potential hairpin that can be formed after digestion with restriction endonuclease Asp718 in its correct orientation and in the reverse orientation, respectively (FIG. 15 (SEQ ID NO:22)).
[0184] For example, pICLhaw is a plasmid that contains the adenovirus ITR followed by the CMV-driven luciferase gene and the Asp718 hairpin in the reverse (nonfunctional) orientation.
[0185] Experiment Series 1
[0186] The following demonstrates the competence of a synthetic DNA sequence that is capable of forming a hairpin structure to serve as a primer for reverse strand synthesis for the generation of double-stranded DNA molecules in cells that contain and express adenovirus genes.
[0187] Plasmids pICLhac, pICLhaw, pICLI and pICL (SEQ ID NO:21) were generated using standard techniques. The schematic representation of these plasmids is shown in FIGS. 16 - 19 .
[0188] Plasmid pICL (SEQ ID NO:21) is derived from the following plasmids:
[0189] nt.1-457 pMLP10 (Levrero et al., 1991);
[0190] nt.458-1218 pCMVβ (Clontech, EMBL Bank No. U02451);
[0191] nt.1219-3016 pMLP.luc (IntroGene, Leiden, NL, unpublished); and
[0192] nt.3017-5620 pBLCAT5 (Stein and Whelan, 1989).
[0193] The plasmid has been constructed as follows:
[0194] The tet gene of plasmid pMLP10 has been inactivated by deletion of the BamHI-SalI fragment to generate pMLP10ΔSB. Using primer set PCR/MLP1 (SEQ ID NO:14) and PCR/MLP3 (SEQ ID NO:16), a 210 bp fragment containing the Ad5-ITR, flanked by a synthetic SalI restriction site, was amplified using pMLP10 DNA as the template. The PCR product was digested with the enzymes EcoRI and SgrAI to generate a 196 bp fragment. Plasmid pMLP10ΔSB was digested with EcoRI and SgrAI to remove the ITR. This fragment was replaced by the EcoRI-SgrAI-treated PCR fragment to generate pMLP/SAL. Plasmid pCMV-Luc was digested with PvuII to completion and recirculated to remove the SV40-derived polyadenylation signal and Ad5 sequences with the exception of the Ad5 left-terminus. In the resulting plasmid, pCMV-lucΔAd, the Ad5 ITR was replaced by the Sal-site-flanked ITR from plasmid pMLP/SAL by exchanging the XmnI-SacII fragments. The resulting plasmid, pCMV-lucΔAd/SAL, the Ad5 left terminus, and the CMV-driven luciferase gene were isolated as an SalI-SmaI fragment and inserted in the SalI and HpaI digested plasmid pBLCATS to form plasmid pICL (SEQ ID NO:21). Plasmid pICL is represented in FIG. 19; its sequence is presented in FIGS. 20 A- 20 F (SEQ ID NO:21).
[0195] The plasmid pICL (SEQ ID NO:21) contains the following features:
[0196] nt. 1-457 Ad5 left terminus (Sequence 1-457 of human adenovirus type 5);
[0197] nt. 458-969 Human cytomegalovirus enhancer and immediate early promoter (see Boshart et al., A Very Strong Enhancer is Located Upstream of an Immediate Early Gene of Human Cytomegalovirus”, Cell 41, pp. 521-530 (1985), hereby incorporated herein by reference) (from plasmid pCMVβ, Clontech, Palo Alto, USA);
[0198] nt. 970-1204 SV40 19S exon and truncated 16/19S intron (from plasmid pCMVβ);
[0199] nt. 1218-2987 Firefly luciferase gene (from pMLP.luc);
[0200] nt. 3018-3131 V40 tandem polyadenylation signals from late transcript, derived from plasmid pBLCAT5);
[0201] t. 3132-5620 UC12 backbone (derived from plasmid pBLCAT5); and
[0202] t. 4337-5191 β-lactamase gene (Amp-resistance gene, reverse orientation).
[0203] Plasmids pICLhac and pICLhaw
[0204] Plasmids pICLhac and pICLhaw were derived from plasmid pICL (SEQ ID NO:21) by digestion of the latter plasmid with the restriction enzyme Asp718. The linearized plasmid was treated with Calf-Intestine Alkaline Phosphatase to remove the 51 phosphate groups. The partially complementary synthetic single-stranded oligonucleotide Hp/asp1 (SEQ ID NO:17) and Hp/asp2 (SEQ ID NO:18) were annealed and phosphorylated on their 5′ ends using T4-polynucleotide kinase.
[0205] The phosporylated double-stranded oligomers were mixed with the dephosporylated pICL fragment and ligated. Clones containing a single copy of the synthetic oligonucleotide inserted into the plasmid were isolated and characterized using restriction enzyme digests. Insertion of the oligonucleotide into the Asp718 site will at one junction recreate an Asp718 recognition site, whereas at the other junction, the recognition site will be disrupted. The orientation and the integrity of the inserted oligonucleotide were verified in selected clones by sequence analyses. A clone containing the oligonucleotide in the correct orientation (the Asp718 site close to the 3205 EcoRI site) was denoted pICLhac. A clone with the oligonucleotide in the reverse orientation (the Asp718 site close to the SV40-derived poly signal) was designated pICLhaw. Plasmids pICLhac and pICLhaw are represented in FIGS. 16 and 17.
[0206] Plasmid pICLI was created from plasmid pICL (SEQ ID NO:21) by insertion of the SalI-SgrAI fragment from pICL containing the Ad5-ITR into the Asp718 site of pICL. The 194 bp SalI-SgrAI fragment was isolated from pICL (SEQ ID NO:21), and the cohesive ends were converted to blunt ends using E. coli DNA polymerase I (Klenow fragment) and dNTPs. The Asp718 cohesive ends were converted to blunt ends by treatment with mungbean nuclease. Clones that contain the ITR in the Asp718 site of plasmid pICL (SEQ ID NO:21) were generated by ligation. A clone that contained the ITR fragment in the correct orientation was designated pICLI (see FIG. 18). Generation of adenovirus Ad-CMV-hcTK recombinant adenovirus was constructed according to the method described in European patent application EP 95202213. Two components are required to generate a recombinant adenovirus. First, an adaptor-plasmid containing the left terminus of the adenovirus genome containing the ITR and the packaging signal, an expression cassette with the gene of interest, and a portion of the adenovirus genome which can be used for homologous recombination. In addition, adenovirus DNA is needed for recombination with the aforementioned adaptor plasmid. In the case of Ad-CMV-hcTK, the plasmid PCMV.TK was used as a basis. This plasmid contains nt. 1-455 of the adenovirus type 5 genome, nt. 456-1204 derived from pCMVβ (Clontech, the PstI-StuI fragment that contains the CMV enhancer promoter and the 16S/19S intron from Simian Virus 40), the HSV TK gene (described in European patent application EP 95202213), the SV40-derived polyadenylation signal (nt 2533-2668 of the SV40 sequence), followed by the BglII-ScaI fragment of Ad5 (nt. 3328-6092 of the Ad5 sequence). These fragments are present in a pMLP10-derived (Levrero et al., 1991) backbone. To generate plasmid pAD-CMVhc-TK, plasmid pCMV.TK was digested with ClaI (the unique ClaI-site is located just upstream of the TK open reading frame) and dephosphorylated with Calf-Intestine Alkaline Phosphate. To generate a hairpin structure, the synthetic oligonucleotides HP/cla1 (SEQ ID NO: 19) and HP/cla2 (SEQ ID NO:20) were annealed and phosphorylated on their 5-OH groups with T4-polynucleotide kinase and ATP. The double-stranded oligonucleotide was ligated with the linearized vector fragment and used to transform E. coli strain “Sure”. Insertion of the oligonucleotide into the ClaI site will disrupt the ClaI recognition sites. The oligonucleotide contains a new ClaI site near one of its termini. In selected clones, the orientation and the integrity of the inserted oligonucleotide was verified by sequence analyses. A clone containing the oligonucleotide in the correct orientation (the ClaI site at the ITR side) was denoted pAd-CMV-hcTK. This plasmid was co-transfected with ClaI-digested wild-type Adenovirus type 5 DNA into 911 cells. A recombinant adenovirus in which the CMV-hcTK expression cassette replaces the E1 sequences was isolated and propagated using standard procedures.
[0207] To study whether the hairpin can be used as a primer for reverse strand synthesis on the displaced strand after replication had started at the ITR, the plasmid pICLhac is introduced into 911 cells (human embryonic retinoblasts transformed with the adenovirus E1 region). The plasmid pICLhaw serves as a control, which contains the oligonucleotide pair HP/asp1 (SEQ ID NO:17) and HP/asp2 (SEQ ID NO:18) in the reverse orientation but is further completely identical to plasmid pICLhac. Also included in these studies are plasmids pICLI and pICL (SEQ ID NO:21). In the plasmid pICLI, the hairpin is replaced by an adenovirus ITR. Plasmid pICL (SEQ ID NO:21) contains neither a hairpin nor an ITR sequence. These plasmids serve as controls to determine the efficiency of replication by virtue of the terminal-hairpin structure. To provide the viral products other than the E1 proteins (these are produced by the 911 cells) required for DNA replication, the cultures are infected with the virus IG.Ad.MLPI.TK after transfection. Several parameters are being studied to demonstrate proper replication of the transfected DNA molecules. First, DNA extracted from the cell cultures transfected with the aforementioned plasmids and infected with IG.Ad.MLPI.TK virus is being analyzed by Southern blotting for the presence of the expected replication intermediates, as well as for the presence of the duplicated genomes. Furthermore, virus is isolated from the transfected and IG.Ad.MLPI.TK infected cell populations that is capable of transferring and expressing a luciferase marker gene into luciferase negative cells.
[0208] Plasmid DNA of plasmids pICLhac, pICLhaw, pICLI, and pICL (SEQ ID NO:21) have been digested with restriction endonuclease SalI and treated with mungbean nuclease to remove the 4 nucleotide single-stranded extension of the resulting DNA fragment. In this manner, a natural adenovirus 5′ ITR terminus on the DNA fragment is created. Subsequently, both the pICLhac and pICLhaw plasmids were digested with restriction endonuclease Asp718 to generate the terminus capable of forming a hairpin structure. The digested plasmids are introduced into 911 cells, using the standard calcium phosphate coprecipitation technique, four dishes for each plasmid. During the transfection, for each plasmid two of the cultures are infected with the IG.Ad.MLPI.TK virus using 5 infectious IG.Ad.MLPI.TK particles per cell. At twenty hours post-transfection and forty hours post-transfection, one Ad.tk-virus-infected and one uninfected culture are used to isolate small molecular-weight DNA using the procedure devised by Hirt. Aliquots of isolated DNA are used for Southern analysis. After digestion of the samples with restriction endonuclease EcoRI using the luciferase gene as a probe, a hybridizing fragment of approximately 2.6 kb is detected only in the samples from the adenovirus infected cells transfected with plasmid pICLhac. The size of this fragment is consistent with the anticipated duplication of the luciferase marker gene. This supports the conclusion that the inserted hairpin is capable of serving as a primer for reverse strand synthesis. The hybridizing fragment is absent if the IG.Ad.MLPI.TK virus is omitted or if the hairpin oligonucleotide has been inserted in the reverse orientation.
[0209] The restriction endonuclease DpnI recognizes the tetranucleotide sequence 5′-GATC-3′ but cleaves only methylated DNA (that is, only plasmid DNA propagated in and derived from E. coli, not DNA that has been replicated in mammalian cells). The restriction endonuclease MboI recognizes the same sequences, but cleaves only unmethylated DNA (viz. DNA propagated in mammalian cells). DNA samples isolated from the transfected cells are incubated with MboI and DpnI and analyzed with Southern blots. These results demonstrate that only in the cells transfected with the pICLhac and the pICLI plasmids are large DpnI-resistant fragments present that are absent in the MboI treated samples. These data demonstrate that only after transfection of plasmids pICLI and pICLhac does replication and duplication of the fragments occur.
[0210] These data demonstrate that in adenovirus-infected cells, linear DNA fragments that have on one terminus an adenovirus-derived ITR and at the other terminus a nucleotide sequence that can anneal to sequences on the same strand when present in single-stranded form thereby generate a hairpin structure and will be converted to structures that have inverted terminal repeat sequences on both ends. The resulting DNA molecules will replicate by the same mechanism as the wild-type adenovirus genomes.
[0211] Experiment Series 2
[0212] The following demonstrates that the DNA molecules that contain a luciferase marker gene, a single copy of the ITR, the encapsidation signal, and a synthetic DNA sequence that is capable of forming a hairpin structure are sufficient to generate DNA molecules that can be encapsidated into virions.
[0213] To demonstrate that the above DNA molecules containing two copies of the CMV-luc marker gene can be encapsidated into virions, virus is harvested from the remaining two cultures via three cycles of freeze-thaw crushing and is used to infect murine fibroblasts. Forty-eight hours after infection, the infected cells are assayed for luciferase activity. To exclude the possibility that the luciferase activity has been induced by transfer of free DNA, rather than via virus particles, virus stocks are treated with DNaseI to remove DNA contaminants. Furthermore, as an additional control, aliquots of the virus stocks are incubated for 60 minutes at 56° C. The heat treatment will not affect the contaminating DNA but will inactivate the viruses. Significant luciferase activity is only found in the cells after infection with the virus stocks derived from IG.Ad.MLPI.TK-infected cells transfected with the pICLhac and pICLI plasmids. In neither the noninfected cells nor the infected cells transfected with the pICLhaw and pICL (SEQ ID NO:21) can significant luciferase activity be demonstrated. Heat inactivation, but not DNaseI treatment, completely eliminates luciferase expression, demonstrating that adenovirus particles, and not free (contaminating) DNA fragments, are responsible for transfer of the luciferase reporter gene.
[0214] These results demonstrate that these small viral genomes can be encapsidated into adenovirus particles and suggest that the ITR and the encapsidation signal are sufficient for encapsidation of linear DNA fragments into adenovirus particles. These adenovirus particles can be used for efficient gene transfer. When introduced into cells that contain and express at least part of the adenovirus genes (viz. E1, E2, E4, and L, and VA), recombinant DNA molecules that consist of at least one ITR, at least part of the encapsidation signal, and a synthetic DNA sequence that is capable of forming a hairpin structure have the intrinsic capacity to autonomously generate recombinant genomes that can be encapsidated into virions. Such genomes and vector system can be used for gene transfer.
[0215] Experiment Series 3
[0216] The following demonstrates that DNA molecules that contain nucleotides 3510-35953 (viz. 9.7-100 map units) of the adenovirus type 5 genome (thus lacking the E1 protein-coding regions, the right-hand ITR, and the encapsidation sequences) and a terminal DNA sequence that is complementary to a portion of the same strand of the DNA molecule when present in single-stranded form other than the ITR, and as a result is capable of forming a hairpin structure, can replicate in 911 cells.
[0217] In order to develop a replicating DNA molecule that can provide the adenovirus products required to allow the above-mentioned pICLhac vector genome and alike minimal adenovectors to be encapsidated into adenovirus particles by helper cells, the Ad-CMV-hcTK adenoviral vector has been developed. Between the CMV enhancer/promoter region and the thymidine kinase gene, the annealed oligonucleotide pair HP/cla1 (SEQ ID NO: 19) and 2 (SEQ ID NO:20) is inserted. The vector Ad-CMV-hcTK can be propagated and produced in 911 cell using standard procedures. This vector is grown and propagated exclusively as a source of DNA used for transfection. DNA of the adenovirus Ad-CMV-hcTK is isolated from virus particles that had been purified using CsC1 density-gradient centrifugation by standard techniques. The virus DNA has been digested with restriction endonuclease ClaI. The digested DNA is size-fractionated on a 0.7% agarose gel, and the large fragment is isolated and used for further experiments. Cultures of 911 cells are transfected with the large ClaI-fragment of the Ad-CMV-hcTK DNA using the standard calcium phosphate coprecipitation technique. Much like in the previous experiments with plasmid pICLhac, the AD-CMV-hc will replicate starting at the right-hand ITR. Once the one strand is displaced, a hairpin can be formed at the left-hand terminus of the fragment. This facilitates the DNA polymerase to elongate the chain towards the right-hand side. The process will proceed until the displaced strand is completely converted to its double-stranded form. Finally, the right-hand ITR will be recreated, and in this location the normal adenovirus replication-initiation and elongation will occur. Note that the polymerase will read through the hairpin, thereby duplicating the molecule. The input DNA molecule of 33250 bp, which had on one side an adenovirus ITR sequence and at the other side a DNA sequence that had the capacity to form a hairpin structure, has now been duplicated in a way that both ends contain an ITR sequence. The resulting DNA molecule will consist of a palindromic structure of approximately 66500 bp.
[0218] This structure can be detected in low-molecular-weight DNA extracted from the transfected cells using Southern analysis. The palindromic nature of the DNA fragment can be demonstrated by digestion of the low-molecular-weight DNA with suitable restriction endonucleases and Southern blotting with the HSV-TK gene as the probe. This molecule can replicate itself in the transfected cells by virtue of the adenovirus gene products that are present in the cells. In part, the adenovirus genes are expressed from templates that are integrated in the genome of the target cells (viz. the E1 gene products); the other genes reside in the replicating DNA fragment itself. Note, however, that this linear DNA fragment cannot be encapsidated into virions. Not only does it lack all the DNA sequences required for encapsidation, but its size is also much too large to be encapsidated.
[0219] Experiment Series 4
[0220] The following demonstrates that DNA molecules that contain nucleotides 3503-35953 (viz. 9.7-100 map units) of the adenovirus type 5 genome (thus lacking the E1 protein-coding regions, the right-hand ITR, and the encapsidation sequences) and a terminal DNA sequence that is complementary to a portion of the same strand of the DNA molecule other than the ITR, and as a result is capable of forming a hairpin structure, can replicate in 911 cells and can provide the helper functions required to encapsidate the pICLI- and pICLhac-derived DNA fragments.
[0221] The following series of experiments aims to demonstrate that the DNA molecule described in Experiment Series 3 could be used to encapsidate the minimal adenovectors described in Experiment Series 1 and 2.
[0222] In the experiments, the large fragment isolated after endonuclease ClaI-digestion of Ad-CMV-hcTK DNA is introduced into 911 cells (in conformity with the experiments described in part 1.3) together with endonuclease SalI, mungbean nuclease, endonuclease Asp718-treated plasmid pICLhac, or, as a control, similarly treated plasmid pICLhaw. After 48 hours, virus is isolated by freeze-thaw crushing of the transfected cell population. The virus preparation is treated with DNaseI to remove contaminating free DNA. The virus is used subsequently to infect Rat2 fibroblasts. Forty-eight hours post-infection, the cells are assayed for luciferase activity. Significant luciferase activity can be demonstrated only in the cells infected with virus isolated from the cells transfected with the pICLhac plasmid and not with the pICLhaw plasmid. Heat inactivation of the virus prior to infection completely abolishes the luciferase activity, indicating that the luciferase gene is transferred by a viral particle. Infection of 911 cells with the virus stock did not result in any cytopathological effects, demonstrating that the pICLhac is produced without any infectious helper virus that can be propagated on 911 cells. These results demonstrate that the proposed method can be used to produce stocks of minimal adenoviral vectors that are completely devoid of infectious helper viruses and are able to replicate autonomously on adenovirus-transformed human cells or on nonadenovirus-transformed human cells.
[0223] Besides the system described in this application, another approach for the generation of minimal adenovirus vectors has been disclosed in International Patent Publication WO 94/12649. The method described in WO 94/12649 exploits the function of the protein IX for the packaging of minimal adenovirus vectors (Pseudo Adenoviral Vectors (“PAV”) in the terminology of WO 94/12649). PAVs are produced by cloning an expression plasmid with the gene of interest between the left-hand (including the sequences required for encapsidation) and the right-hand adenoviral ITRs. The PAV is propagated in the presence of a helper virus. Encapsidation of the PAV is preferred compared with the helper virus because the helper virus is partially defective for packaging (either by virtue of mutations in the packaging signal or by virtue of its size; virus genomes greater than 37.5 kb package inefficiently). In addition, the authors propose that in the absence of the protein IX gene, the PAV will be preferentially packaged. However, neither of these mechanisms appear to be sufficiently restrictive to allow packaging of only PAVs/minimal vectors. The mutations proposed in the packaging signal diminish packaging but do not provide an absolute block, as the same packaging activity is required to propagate the helper virus. Also, neither an increase in the size of the helper virus nor the mutation of the protein IX gene will ensure that PAV is packaged exclusively. Thus, the method described in WO 94/12649 is unlikely to be useful for the production of helper-free stocks of minimal adenovirus vectors/PAVs.
[0224] Although the application has been described with reference to certain preferred embodiments and illustrative examples, the scope of the invention is to be determined by reference to the appended claims.
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0
SEQUENCE LISTING
<160> NUMBER OF SEQ ID NOS: 22
<210> SEQ ID NO 1
<211> LENGTH: 21
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer Ea-1
<400> SEQUENCE: 1
cgtgtagtgt atttataccc g 21
<210> SEQ ID NO 2
<211> LENGTH: 21
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artifical Sequence: Primer Ea-2
<400> SEQUENCE: 2
tcgtcactgg gtggaaagcc a 21
<210> SEQ ID NO 3
<211> LENGTH: 21
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer Ea-3
<400> SEQUENCE: 3
tacccgccgt cctaaaatgg c 21
<210> SEQ ID NO 4
<211> LENGTH: 20
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer
Ea-5
<400> SEQUENCE: 4
tggacttgag ctgtaaacgc 20
<210> SEQ ID NO 5
<211> LENGTH: 21
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer Ep-2
<400> SEQUENCE: 5
gcctccatgg aggtcagatg t 21
<210> SEQ ID NO 6
<211> LENGTH: 20
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer Eb-1
<400> SEQUENCE: 6
gcttgagccc gagacatgtc 20
<210> SEQ ID NO 7
<211> LENGTH: 24
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer Eb-2
<400> SEQUENCE: 7
cccctcgagc tcaatctgta tctt 24
<210> SEQ ID NO 8
<211> LENGTH: 27
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer
SV40-1
<400> SEQUENCE: 8
gggggatccg aacttgttta ttgcagc 27
<210> SEQ ID NO 9
<211> LENGTH: 25
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer
SV40-2
<400> SEQUENCE: 9
gggagatcta gacatgataa gatac 25
<210> SEQ ID NO 10
<211> LENGTH: 27
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer
Ad5-1
<400> SEQUENCE: 10
gggagatctg tactgaaatg tgtgggc 27
<210> SEQ ID NO 11
<211> LENGTH: 24
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer
Ad5-2
<400> SEQUENCE: 11
ggaggctgca gtctccaacg gcgt 24
<210> SEQ ID NO 12
<211> LENGTH: 27
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer ITR1
<400> SEQUENCE: 12
gggggatcct caaatcgtca cttccgt 27
<210> SEQ ID NO 13
<211> LENGTH: 27
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: Primer ITR2
<400> SEQUENCE: 13
ggggtctaga catcatcaat aatatac 27
<210> SEQ ID NO 14
<211> LENGTH: 32
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: PCR primer
PCR/MLP1
<400> SEQUENCE: 14
ggcgaattcg tcgacatcat caataatata cc 32
<210> SEQ ID NO 15
<211> LENGTH: 32
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: PCT primer
PCR/MLP2
<400> SEQUENCE: 15
ggcgaattcg gtaccatcat caataatata cc 32
<210> SEQ ID NO 16
<211> LENGTH: 17
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: PCT primer
PCR/MLP3
<400> SEQUENCE: 16
ctgtgtacac cggcgca 17
<210> SEQ ID NO 17
<211> LENGTH: 50
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: PCT primer
HP/asp1
<400> SEQUENCE: 17
gtacactgac ctagtgccgc ccgggcaaag cccgggcggc actaggtcag 50
<210> SEQ ID NO 18
<211> LENGTH: 50
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: PCT primer
HP/asp2
<400> SEQUENCE: 18
gtacctgacc tagtgccgcc cgggctttgc ccgggcggca ctaggtcagt 50
<210> SEQ ID NO 19
<211> LENGTH: 55
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: PCT primer
HP/cla1
<400> SEQUENCE: 19
gtacattgac ctagtgccgc ccgggcaaag cccgggcggc actaggtcaa tcgat 55
<210> SEQ ID NO 20
<211> LENGTH: 55
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY:
<222> LOCATION:
<223> OTHER INFORMATION: Description of Artificial Sequence: primer
HP/cla2
<400> SEQUENCE: 20
gtacatcgat tgacctagtg ccgcccgggc tttgcccggg cggcactagg tcaat 55
<210> SEQ ID NO 21
<211> LENGTH: 5620
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY: Ad5 left terminus
<222> LOCATION: 1..457
<221> NAME/KEY: enhancer
<222> LOCATION: 458..969
<221> NAME/KEY: exon
<222> LOCATION: 970..1204
<221> NAME/KEY: gene
<222> LOCATION: 1218..2987
<221> NAME/KEY: polyA_signal
<222> LOCATION: 3018..3131
<221> NAME/KEY: pUC12 backbone
<222> LOCATION: 3132..5620
<221> NAME/KEY: gene
<222> LOCATION: 4337..5191
<223> OTHER INFORMATION: Description of Artificial Sequence: Plasmid
pICL
<400> SEQUENCE: 21
catcatcaat aatatacctt attttggatt gaagccaata tgataatgag ggggtggagt 60
ttgtgacgtg gcgcggggcg tgggaacggg gcgggtgacg tagtagtgtg gcggaagtgt 120
gatgttgcaa gtgtggcgga acacatgtaa gcgacggatg tggcaaaagt gacgtttttg 180
gtgtgcgccg gtgtacacag gaagtgacaa ttttcgcgcg gttttaggcg gatgttgtag 240
taaatttggg cgtaaccgag taagatttgg ccattttcgc gggaaaactg aataagagga 300
agtgaaatct gaataatttt gtgttactca tagcgcgtaa tatttgtcta gggccgcggg 360
gactttgacc gtttacgtgg agactcgccc aggtgttttt ctcaggtgtt ttccgcgttc 420
cgggtcaaag ttggcgtttt attattatag tcaggggctg caggtcgtta cataacttac 480
ggtaaatggc ccgcctggct gaccgcccaa cgacccccgc ccattgacgt caataatgac 540
gtatgttccc atagtaacgc caatagggac tttccattga cgtcaatggg tggagtattt 600
acggtaaact gcccacttgg cagtacatca agtgtatcat atgccaagta cgccccctat 660
tgacgtcaat gacggtaaat ggcccgcctg gcattatgcc cagtacatga ccttatggga 720
ctttcctact tggcagtaca tctacgtatt agtcatcgct attaccatgg tgatgcggtt 780
ttggcagtac atcaatgggc gtggatagcg gtttgactca cggggatttc caagtctcca 840
ccccattgac gtcaatggga gtttgttttg gcaccaaaat caacgggact ttccaaaatg 900
tcgtaacaac tccgccccat tgacgcaaat gggcggtagg cgtgtacggt gggaggtcta 960
tataagcaga gctcgtttag tgaaccgtca gatcgcctgg agacgccatc cacgctgttt 1020
tgacctccat agaagacacc gggaccgatc cagcctccgg actctagagg atccggtact 1080
cgaggaactg aaaaaccaga aagttaactg gtaagtttag tctttttgtc ttttatttca 1140
ggtcccggat ccggtggtgg tgcaaatcaa agaactgctc ctcagtggat gttgccttta 1200
cttctagtat caagcttgaa ttcctttgtg ttacattctt gaatgtcgct cgcagtgaca 1260
ttagcattcc ggtactgttg gtaaaatgga agacgccaaa aacataaaga aaggcccggc 1320
gccattctat cctctagagg atggaaccgc tggagagcaa ctgcataagg ctatgaagaa 1380
atacgccctg gttcctggaa caattgcttt tacagatgca catatcgagg tgaacatcac 1440
gtacgcggaa tacttcgaaa tgtccgttcg gttggcagaa gctatgaaac gatatgggct 1500
gaatacaaat cacagaatcg tcgtatgcag tgaaaactct cttcaattct ttatgccggt 1560
gttgggcgcg ttatttatcg gagttgcagt tgcgcccgcg aacgacattt ataatgaacg 1620
tgaattgctc aacagtatga acatttcgca gcctaccgta gtgtttgttt ccaaaaaggg 1680
gttgcaaaaa attttgaacg tgcaaaaaaa attaccaata atccagaaaa ttattatcat 1740
ggattctaaa acggattacc agggatttca gtcgatgtac acgttcgtca catctcatct 1800
acctcccggt tttaatgaat acgattttgt accagagtcc tttgatcgtg acaaaacaat 1860
tgcactgata atgaattcct ctggatctac tgggttacct aagggtgtgg cccttccgca 1920
tagaactgcc tgcgtcagat tctcgcatgc cagagatcct atttttggca atcaaatcat 1980
tccggatact gcgattttaa gtgttgttcc attccatcac ggttttggaa tgtttactac 2040
actcggatat ttgatatgtg gatttcgagt cgtcttaatg tatagatttg aagaagagct 2100
gtttttacga tcccttcagg attacaaaat tcaaagtgcg ttgctagtac caaccctatt 2160
ttcattcttc gccaaaagca ctctgattga caaatacgat ttatctaatt tacacgaaat 2220
tgcttctggg ggcgcacctc tttcgaaaga agtcggggaa gcggttgcaa aacgcttcca 2280
tcttccaggg atacgacaag gatatgggct cactgagact acatcagcta ttctgattac 2340
acccgagggg gatgataaac cgggcgcggt cggtaaagtt gttccatttt ttgaagcgaa 2400
ggttgtggat ctggataccg ggaaaacgct gggcgttaat cagagaggcg aattatgtgt 2460
cagaggacct atgattatgt ccggttatgt aaacaatccg gaagcgacca acgccttgat 2520
tgacaaggat ggatggctac attctggaga catagcttac tgggacgaag acgaacactt 2580
cttcatagtt gaccgcttga agtctttaat taaatacaaa ggatatcagg tggcccccgc 2640
tgaattggaa tcgatattgt tacaacaccc caacatcttc gacgcgggcg tggcaggtct 2700
tcccgacgat gacgccggtg aacttcccgc cgccgttgtt gttttggagc acggaaagac 2760
gatgacggaa aaagagatcg tggattacgt cgccagtcaa gtaacaaccg cgaaaaagtt 2820
gcgcggagga gttgtgtttg tggacgaagt accgaaaggt cttaccggaa aactcgacgc 2880
aagaaaaatc agagagatcc tcataaaggc caagaagggc ggaaagtcca aattgtaaaa 2940
tgtaactgta ttcagcgatg acgaaattct tagctattgt aatgggggat ccccaacttg 3000
tttattgcag cttataatgg ttacaaataa agcaatagca tcacaaattt cacaaataaa 3060
gcattttttt cactgcattc tagttgtggt ttgtccaaac tcatcaatgt atcttatcat 3120
gtctggatcg gatcgatccc cgggtaccga gctcgaattc gtaatcatgg tcatagctgt 3180
ttcctgtgtg aaattgttat ccgctcacaa ttccacacaa catacgagcc ggaagcataa 3240
agtgtaaagc ctggggtgcc taatgagtga gctaactcac attaattgcg ttgcgctcac 3300
tgcccgcttt ccagtcggga aacctgtcgt gccagctgca ttaatgaatc ggccaacgcg 3360
cggggagagg cggtttgcgt attgggcgct cttccgcttc ctcgctcact gactcgctgc 3420
gctcggtcgt tcggctgcgg cgagcggtat cagctcactc aaaggcggta atacggttat 3480
ccacagaatc aggggataac gcaggaaaga acatgtgagc aaaaggccag caaaaggcca 3540
ggaaccgtaa aaaggccgcg ttgctggcgt ttttccatag gctccgcccc cctgacgagc 3600
atcacaaaaa tcgacgctca agtcagaggt ggcgaaaccc gacaggacta taaagatacc 3660
aggcgtttcc ccctggaagc tccctcgtgc gctctcctgt tccgaccctg ccgcttaccg 3720
gatacctgtc cgcctttctc ccttcgggaa gcgtggcgct ttctcatagc tcacgctgta 3780
ggtatctcag ttcggtgtag gtcgttcgct ccaagctggg ctgtgtgcac gaaccccccg 3840
ttcagcccga ccgctgcgcc ttatccggta actatcgtct tgagtccaac ccggtaagac 3900
acgacttatc gccactggca gcagccactg gtaacaggat tagcagagcg aggtatgtag 3960
gcggtgctac agagttcttg aagtggtggc ctaactacgg ctacactaga aggacagtat 4020
ttggtatctg cgctctgctg aagccagtta ccttcggaaa aagagttggt agctcttgat 4080
ccggcaaaca aaccaccgct ggtagcggtg gtttttttgt ttgcaagcag cagattacgc 4140
gcagaaaaaa aggatctcaa gaagatcctt tgatcttttc tacggggtct gacgctcagt 4200
ggaacgaaaa ctcacgttaa gggattttgg tcatgagatt atcaaaaagg atcttcacct 4260
agatcctttt aaattaaaaa tgaagtttta aatcaatcta aagtatatat gagtaaactt 4320
ggtctgacag ttaccaatgc ttaatcagtg aggcacctat ctcagcgatc tgtctatttc 4380
gttcatccat agttgcctga ctccccgtcg tgtagataac tacgatacgg gagggcttac 4440
catctggccc cagtgctgca atgataccgc gagacccacg ctcaccggct ccagatttat 4500
cagcaataaa ccagccagcc ggaagggccg agcgcagaag tggtcctgca actttatccg 4560
cctccatcca gtctattaat tgtttgccgg aagctagagt aagtagttcg ccagttaata 4620
gtttgcgcaa cgttgttgcc attgctacag gcatcgtggt gtcacgctcg tcgtttggta 4680
tggcttcatt cagctccggt tcccaacgat caaggcgagt tacatgatcc cccatgttgt 4740
gcaaaaaagc ggttagctcc ttcggtgctc cgatcgttgt cagaagtaag ttggccgcag 4800
tgttatcact catggttatg gcagcactgc ataattctct tactgtcatg ccatccgtaa 4860
gatgcttttc tgtgactggt gagtactcaa ccaagtcatt ctgagaatag tgtatgcggc 4920
gaccgagttg ctcttgcccg gcgtcaatac gggataatac cgcgccacat agcagaactt 4980
taaaagtgct catcattgga aaacgttctt cggggcgaaa actctcaagg atcttaccgc 5040
tgttgagatc cagttcgatg taacccactc gtgcacccaa ctgatcttca gcatctttta 5100
ctttcaccag cgtttctggg tgagcaaaaa caggaaggca aaatgccgca aaaaagggaa 5160
taagggcgac acggaaatgt tgaatactca tactcttcct ttttcaatat tattgaagca 5220
tttatcaggg ttattgtctc atgagcggat acatatttga atgtatttag aaaaataaac 5280
aaataggggt tccgcgcaca tttccccgaa aagtgccacc tgacgtctaa gaaaccatta 5340
ttatcatgac attaacctat aaaaataggc gtatcacgag gcctatgcgg tgtgaaatac 5400
cgcacagatg cgtaaggaga aaataccgca tcaggcgcca ttcgccattc aggctgcgca 5460
actgttggga agggcgatcg gtgcgggcct cttcgctatt acgccagctg gcgaaagggg 5520
gatgtgctgc aaggcgatta agttgggtaa cgccagggtt ttcccagtca cgacgttgta 5580
aaacgacggc cagtgccaag cttgcatgcc tgcaggtcga 5620
<210> SEQ ID NO 22
<211> LENGTH: 45
<212> TYPE: DNA
<213> ORGANISM: Artificial Sequence
<220> FEATURE:
<221> NAME/KEY: stem_loop
<222> LOCATION: 11..45
<223> OTHER INFORMATION: Description of Artificial Sequence: Asp 718
hairpin
<400> SEQUENCE: 22
gtacactgac ctagtgccgc ccgggcaaag cccgggcggc actag 45 | Presented are ways to address the problem of replication competent adenovirus in adenoviral production for use with, for example, gene therapy. Packaging cells having no overlapping sequences with a selected vector are suited for large scale production of recombinant adenoviruses. A system for use with the invention produces replication-defective adenovirus. The system includes a primary cell containing a nucleic acid based on or derived from adenovirus and an isolated recombinant nucleic acid molecule for transfer into the primary cell. The isolated recombinant nucleic acid molecule is based on or derived from an adenovirus, has at least one functional encapsidation signal and at least one functional Inverted Terminal Repeat, and lacks overlapping sequences with the nucleic acid of the cell. Otherwise, the overlapping sequences would enable homologous recombination leading to replication competent adenovirus in the primary cell into which the isolated recombinant nucleic acid molecule is to be transferred. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of Taiwan patent application number 092210674 filed on Jun. 11, 2003.
BACKGROUND OF INVENTION
[0002] 1. The Field of the Invention
[0003] The present invention relates to a video game system, and more particularly to a video game system having sound device comprising a sound adaptor and a sound device connected to a first memory card slot and a second memory card slot of a game controller of a video game player such that a player can wirelessly communicate with other players via a microphone and a speaker of the sound device within a valid range via the game controller. Therefore, a player can directly execute a game by wirelessly controlling the game controller without wearing wired earphone and microphone.
[0004] 2. Description of Related Art
[0005] Presently, the online games are popular. Nowadays players can play not only PC games but also the online internet games. Several manufacturers have invested in developing various peripheral products for the video games with a view of achieving user-friendly operations and to provide more convenience to the players. For example, some manufacturers designed using earphone and speaker to enable the player to communicate with other players while playing the game in order to create more fun.
[0006] Referring to FIGS. 1A, 1B, 1 C and 2 , elevational views of a conventional video game system, and elevational view of a conventional game controller and a sound adaptor, a headset and a block diagram of a circuit of a sound device, are respectively shown. The peripheral products available for video game player, Xbox of Microsoft, includes a video game player 10 , a game controller 20 , a sound adaptor 30 , a sound device 40 comprising an earphone 41 and a microphone 42 . The game controller 20 comprises a first memory card slot 22 which is adapted for receiving the sound adaptor 30 having external card bus for allowing communication between the second communication interface 35 and the game controller 20 . The earphone and the microphone 42 are connected to the sound adaptor 30 via the sound transmission wire 43 and the headset jack 34 . Thus, the first control circuit 21 and the first communication interface 25 of the game controller 20 can communicate with the video game player 10 . Furthermore, the game controller 20 comprises a second memory card slot 23 and buttons 24 . The second memory card slot 23 is a reserved slot and the buttons 24 are adapted for controlling the functions of the game. Furthermore, the sound adaptor 30 comprises a second control circuit 31 , a volume regulator 32 and a microphone switch 33 . The second control circuit 31 is adapted for controlling the volume of the earphone 41 and also for turning on/off the microphone 42 .
[0007] However, the above conventional video game system has the following defects.
[0008] 1. The specifications of the earphone 41 and the microphone 42 are different from the other available products, therefore, if the earphone 41 and the microphone 42 are damaged, the user must purchase the whole set as a replacement. Thus, the cost is high and thereby discouraging some players from buying such video game system.
[0009] 2. The earphone 41 and the microphone 42 must be connected via the sound transmission wire 43 to communicate with the sound adaptor 30 for controlling the game controller 20 , and because the length of the wire is limited and may get entangled, therefore causing inconvenience to players.
[0010] 3. Because the earphone 41 and the microphone 42 are designed to directly contact the player's ear, and also the weight of the earphone 41 and the microphone 42 can cause uneasiness to the player after a long time usage.
[0011] 4. The player cannot move freely due to the wired connection of the sound transmission wire 43 and the controller transmission wire.
[0012] 5. The volume regulator 32 and the microphone switch 33 cannot be controlled instantly.
[0013] Besides, the other available video game player, PS2 of Sony, particularly for playing online game, has built-in control interface of the earphone and the microphone. The disadvantage of this product is that the players cannot move freely due to the sound transmission wire and the controller transmission wire.
SUMMARY OF INVENTION
[0014] Accordingly, in the view of the foregoing, the present inventor makes a detailed study of related art to evaluate and consider, and uses years of accumulated experience in this field, and through several experiments, to create a new sound device of video game system. The present invention provides an innovated cost effective sound device of video game system such that a user can execute a game by wirelessly controlling the game controller and wirelessly communicate with other users via the game controller within a valid range without wearing wired microphone and speaker.
[0015] According to an aspect of the present invention, the sound device of the video game comprises a control circuit, a speaker, a microphone, a sound transmission wire and a communication interface. The sound device is connected to a first memory card slot of the game controller via the sound transmission wire so that a player can play the game without wearing the earphone and microphone. The player can communicate with other players via the speaker and the microphone of the sound device inserted into the second memory card slot, thus the players can have more fun.
[0016] According to another aspect of the present invention, the game controller comprises a second memory card slot for power connection to provide power for operating video game player. The headset jack at the distal end of the sound transmission wire is connected to the sound adaptor positioned in the first memory card slot, thus sound signals and data signals can be transmitted/received via sound adaptor and sound device to facilitate the game execution without requiring to wear the earphone and microphone.
[0017] According to another aspect of the present invention, the speaker and the microphone are installed in the game controller. When the player adjusts the volume switch of the microphone, the signal generated while adjusting the volume regulator and the microphone switch is sent to the first control circuit via the second control circuit, the headset jack and the sound transmission wire. The first control circuit is adapted for controlling the volume of the speaker and also for turning on/off the microphone. Therefore, the on-line players need not wear the earphone or microphone while playing the game.
BRIEF DESCRIPTION OF DRAWINGS
[0018] For a more complete understanding of the present invention, reference will now be made to the following detailed description of preferred embodiments taken in conjunction with the following accompanying drawings.
[0019] [0019]FIG. 1A is an elevational view of a conventional video game system.
[0020] [0020]FIG. 1B is an elevational view of a conventional game controller and sound adaptor.
[0021] [0021]FIG. 1C is an elevational view of a conventional headset.
[0022] [0022]FIG. 2 is a block diagram of a circuit of a conventional video game system.
[0023] [0023]FIG. 3A is the elevational view (1) of a video game system according to an embodiment of the present invention.
[0024] [0024]FIG. 3B is an elevational view (2) of a video game system according to an embodiment of the present invention.
[0025] [0025]FIG. 3C is a elevational view (3) of a video game system according to an embodiment of the present invention.
[0026] [0026]FIG. 3D is an elevational view (4) of a video game system according to an embodiment of the present invention.
[0027] [0027]FIG. 3E is an elevational view (5) of a video game system according to an embodiment of the present invention.
[0028] [0028]FIG. 3F is an elevational view (6) of a video game system according to an embodiment of the present invention.
[0029] [0029]FIG. 4 is a block diagram of a circuit of a video game system according to an embodiment of the present invention.
[0030] [0030]FIG. 5A is an elevational view (1) of a video game system according to an embodiment of the present invention.
[0031] [0031]FIG. 5B is an elevational view (2) of a video game system according to an embodiment of the present invention.
[0032] [0032]FIG. 5C is an elevational view (3) of a video game system according to an embodiment of the present invention.
[0033] [0033]FIG. 5D is an elevational view (4) of a video game system according to an embodiment of the present invention.
[0034] [0034]FIG. 5E is an elevational view (5) of a video game system according to an embodiment of the present invention.
[0035] [0035]FIG. 5F is an elevational view (6) of a video game system according to an embodiment of the present invention.
[0036] [0036]FIG. 6 is a block diagram of a circuit of a video game system according to an embodiment of the present invention.
[0037] [0037]FIG. 7 is a block diagram of a circuit of a video game system according to another embodiment of the present invention.
DETAILED DESCRIPTION
[0038] Reference will be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
[0039] Referring to FIG. 3A and FIG. 4, an elevational view (1) of a video game system and a block diagram of a circuit of a video game system according to an embodiment of the present invention are respectively shown. The video game system comprises a video game player 10 , a game controller 20 , a sound adaptor 30 and a sound device 40 . The video game player 10 is connected to a game controller 20 . The game controller 20 is connected to a sound adaptor 30 and the sound device 40 .
[0040] The game controller 20 comprises a first control circuit 21 , a first memory card slot 22 , a second memory card slot 23 , a button 24 and a first communication interface 25 , wherein the first memory card slot 22 , the second memory card slot 23 , the button 24 and the first communication interface 25 are connected to the first control circuit 21 . The sound adaptor 30 is connected to the first memory card slot 22 and the sound device 40 is connected to the second memory card slot 23 .
[0041] The sound adaptor 30 comprises a second control circuit 31 , a volume regulator 32 , a microphone switch 33 , a headset jack 34 and a second communication interface 35 , wherein the volume regulator 32 , the microphone switch 33 , the headset jack 34 and the second communication interface 35 are connected to the second control circuit 31 . The headset jack 34 is connected to a third control circuit 44 of the sound device 40 through a sound transmission wire 43 .
[0042] Furthermore, the sound device 40 comprises the third control circuit 44 , a speaker 45 , a microphone 42 , a sound transmission wire 43 and a third communication interface 46 , wherein the speaker 45 , the microphone 42 , the sound transmission wire 43 and the third communication interface 46 are connected to the third control circuit 44 . The third control circuit 44 receives a sound signal sent from the sound adaptor 30 via the sound transmission wire 43 , as well as a sound signal input by a user transmitted by the microphone 42 . The speaker 45 receives the sound signal transmitted from the third circuit 44 .
[0043] Hereinafter, the assembly of the video game system will be described. The game controller 20 is connected to the video game player 10 . Next, the sound adaptor 30 is inserted into the first memory card slot 22 of the game controller 20 . Next, the headset jack 34 of the sound adaptor 30 is connected into the third control circuit 44 of the sound device 40 via the sound transmission wire 43 .
[0044] Furthermore, the game controller 20 is adapted to control the buttons 24 to transmit signals in an orderly manner via the first control circuit 21 and the first communication interface 25 to the video game player 10 .
[0045] The volume regulator 32 and the microphone switch 33 are adapted for adjusting the volume of the speaker 45 of the sound device 40 and also for turning on/off the microphone 42 . The signals generated during the volume adjustment are transmitted in orderly manner via the second control circuit 31 , the headsetjack 34 and the sound transmission wire 43 to the third control circuit 44 .
[0046] Furthermore, the third control circuit 44 comprises an auto-gain circuit 441 and an echo canceling circuit 442 . The auto-gain circuit 441 is adapted for balancing the over loud volume sound or a low volume sound. The echo canceling circuit 442 is for canceling the echo.
[0047] Now referring to FIG. 3A-3F, are elevational views (1), (2), (3), (4), (5) and (6) of a video game systems according to various embodiments of the present invention, wherein the game controller 20 can be a palm joystick, a steering wheel, a dancing pad, a joystick, a flight joystick or a light beam gun.
[0048] Besides, FIGS. 5A and 6, are elevational view (1) and a block diagram of a circuit of a video game system according an embodiment of the present invention, wherein the speaker 45 and the microphone 42 are installed directly in the game controller 20 . Thus when a player adjusts the volume of the speaker 45 and switch on/off the microphone 42 by operating the volume regulator 32 and the microphone switch 33 , signals generated during the operation of the volume regulator 32 and the microphone switch 33 will be transmitted via the second control circuit 31 , the headset jack 34 and the sound transmission wire 43 to the first control circuit 21 .
[0049] Referring to FIGS. 5A-5F, elevational views (1), (2), (3), (4), (5) and (6) of a video game system according to various embodiments of the present invention are respectively shown. The game controller 20 can be a palm joystick, a steering wheel, a dancing pad, a joystick, a flight joystick or a light beam gun.
[0050] Furthermore, referring to FIG. 7, a block diagram of a circuit of a video game system according to another embodiment of the present invention is shown. The video game player 10 is connected to the game controller 20 . The game controller 20 comprises the first communication interface 25 and the second communication interface 35 . The first communication interface 25 is connected to the first control circuit 21 and the buttons 24 . The second communication interface 35 is connected to the second control circuit 31 . The second control circuit 31 is connected to the speaker 45 , the volume regulator 32 , the microphone 42 and the microphone switch 33 . During the operation of the video game system according the present embodiment of the present invention, the game controller 20 controls the buttons 24 to generate a signal, which is transmitted to the video game player 10 via the first control circuit 21 and the first communication interface 25 in orderly manner. The video game player 10 generates a sound signal and transmits the sound signal to the speaker 45 via the second communication interface 35 and the second control circuit 31 in orderly manner. The volume regulator 32 is adapted for adjusting the volume of the sound device. Furthermore, the microphone 45 receives the sound signal input by the user, and then transmits the sound signal to the video game player 10 in orderly manner via the second control circuit 31 and the second communication interface 35 . The microphone switch 33 is adapted for turning on or off the microphone 42 . Furthermore, the second control circuit 31 comprises the auto-gain circuit 441 and the echo canceling circuit 442 . The auto-gain circuit 441 is adapted for balancing the over loud volume sound or a low volume sound. The echo canceling circuit 442 is for canceling the echo.
[0051] While the invention has been described in conjunction with a specific best mode, it is to be understood that many 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 in which fall within the spirit and scope of the included claims. All matters set forth herein or shown in the accompanying drawings are to be interpreted in an illustrative and nonlimiting sense. | A video game system having sound device is provided. The video game system comprises a sound adaptor and a sound device connected to a first memory card slot and a second memory card slot of a game controller of the video game player such that a user can communicate with other users through a built-in microphone and speaker of the sound device within a valid range via wireless controller. Therefore, a user can directly execute a game by wirelessly controlling the game controller without wearing wired earphone and microphone. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to sighting devices for aligning firearms, geodesic instruments, such as transits, and the like, with a target, accurately and rapidly.
Sighting devices are known such as the pointer sights system which is commonly used for aiming firearms at a target situated at a medium or short distance. Sighting devices of this kind consist of a short rod or pointed projection, or front sight, and of a horizontal, vertically adjustable metallic part with a V-groove, or rear sight, which are both mounted on the weapon or other instrument so that the user sights through the rear sight onto the front sight, and aligns the two sights with the target. In this manner, the eye of the user must be aligned with the rear sight, the front sight and the target, all situated exactly on a single straight line, the so-called target line, or alignment of the instrument with the target is not possible. Such exact alignment of the eye with the target line takes a certain amount of time, proper concentration and adequate skill on the part of a marksman. For this reason, conventional pointer sights systems cannot be used with adequate accuracy by the average person. In addition, accuracy is hampered because the eye is focused to the far-away target, such that the rear and the front sights are seen as out-of-focus blurred images. This disadvantage of pointer sights systems may be reduced by placing the sights as far away from the eye as possible, which can be done only with relatively long firearms, or other devices having a long sight line. In addition, the distance separating the rear and the front sights must be as wide as possible for the sake of better accuracy. This is in contradiction with the requirement of a long distance from the rear sight to the eye, and it is limited by the design length of the firearm or other device. Finally, another disadvantage associated with pointer sights systems is that only the upper half of the target is visible since the lower half of the target is masked by the rear and front sights. This results in a considerable reduction of the overall visibility of the target.
Another well-known sighting device is a modification of the pointer system which is sometimes known under the name "Diopter." In such modification, the rear sight is replaced by an apertured wall or mask which is disposed proximate the eye of the person airming at the target. The tip of the front sight is viewed through this aperture and aligned with the target. In this manner, an improved accuracy may be achieved as compared to the conventional pointer sights system, because the closeness of the aperture to the eye provides a longer distance to the front sight. However, since the aperture must have a very small diameter, for reasons of accuracy, the field of vision through the aperture is considerably restricted, which in turn considerably reduces the visibility of the target.
Sighting devices of higher accuracy, of the telescope type, often called telescopic sights are also known. At the point of view of their optical design, telescopic sights are terrestrial telescopes which, in addition to the objective forming an intermediate image plane and of the ocular, require an additional lens which, through a further projection of the intermediate plane image, effectuates a reconstruction of the image. In one of the two intermediate images, that is between the objective lens and the additional lens, or between the additional lens and the ocular, an adjustable target mark, called a graduated plate, is inserted which is provided with a reticle which is seen through the ocular in the same plane as the target plane. Consequently, the optical characteristics of the ocular, or eyepiece, must be calculated such as to provide an exit pupil situated as far back as possible in order to keep the distance between the eye and the telescopic sight as large as feasible in order to avoid eye injuries due to weapons having a heavy recoil. Telescopic sights have generally a 6× magnification and are thus particularly suited for sighting far-away targets. One of their disadvantages, however, which is due to the substantial magnification, is that only a small section of the target is visible. Thus, the field of view is severly restricted, which is even more important when the target is at a medium or short distance, such that telescopic sights are not particularly well suited for aiming at targets at such medium or short distance. In addition, telescopic sights, due to their optical system design, are expensive and have a barrel which is quite long because of the extended image reversal optical system. An additional disadvantage of telescopic sights is that the black reticle on the graduated plate can only be seen with great difficulty when superimposed on dark targets. Moreover, because of the high magnification and the correspondingly magnified errors due to misadjustment, telescopic sights must be repeatedly re-adjusted with precision.
In addition to the already mentioned disadvantages, the prior art devices described hereinbefore have an important common deficiency. In addition to the requirement that the weapon or other instrument be correctly aligned with the target, it is necessary for the viewer to bring his eyes into the target line with the greatest precision possible in order to judge good aiming. Faulty alignment of the eye is often judged as a sighting error, while the sighting system should not be blamed, which obviously does not mean that sighting errors do not indeed occur.
The mentioned disadvantages due to misalignment of the eye with the target line does not, however, exist with another prior art sighting device disclosed in German Pat. No. 269,447. In this prior art sighting device, the lens barrel which encloses the optical system is so designed that the semi-transparent mirror surface reflecting the target mark is disposed at a considerable distance from the convex optically effective surface in the interior of the lens barrel. The mirror surface is itself curved, its curvature being different from that of the two optically effective surfaces. Because the semi-transparent mirror surface is disposed within the interior of the lens housing, the lens housing is divided into two sections which, for defining this mirror surface as a glass-air surface, are simply joined together by means of an adhesive so as to define the mirror surface, or they can be fused together.
Because of the arrangement consisting of the semi-transparent mirror surface being disposed within the lens itself, there results a complication of the computing of the lens characteristics, resulting in turn in excessive manufacturing costs. Such disadvantage is further compounded because such sighting devices have applications not only in firearms but in photographic equipment, and those devices are manufactured in mass production for which even a slight increase in manufacturing costs has deep economic ramifications.
The present invention accomplishes the results of providing a simple and effective optical sighting device which in addition to being suitable for long distances is also suitable for medium or short distances, which does not present the disadvantages of the prior art sighting devices, and which is also very favorably priced as compared to the cost of manufacturing the prior art sighting devices.
Those objects are accomplished by the present invention as a result of providing an optical sighting device comprising a single lens massive body having one of its optically effective end surfaces provided with a partially transparent and partially reflective coating.
Although the optical sighting device of the present invention is of simple design, it still provides accurate aiming. The whole optical system consists of a single body of glass or other light transmissive material, the single body being provided with opposite optically effective surfaces. The optical surfaces are preferably spherical or rotation-symmetrical, for the sake of simplified manufacturing, but they can, nevertheless, be also developed as aspherical surfaces. A first effective surface, which is optically convex, concentrates the light rays in the fashion of an objective lens for forming an image, and the second, concave, optically effective surface deflects the light prior to formation of the image into infinity, in the same manner as an eyepiece, such as to fulfill the operation of telescope optical elements. The optical sighting device of the invention is therefore a telescope of the simplest design, which can be manufactured at the most modest costs and which is, so to speak, a simplified type of the Galileo, or Dutch-type, telescope which, as is well known, delivers a terrestrial or erect image. Thus, the present invention does not require an additional image reversing lens system. Due to the relatively low magnification of the telescope type sighting system of the invention, the human eye naturally and easily adjusts for varying distances, such that special precise focusing elements are not necessary. In addition, possible eventual misadjustments have less effect upon the human eye in view of the low magnification of the telescope. As a result of the reduced magnification, an added advantage is that the field of view under which the target is sighted is relatively wide, which results in being able to rapidly locate the target and aim at the target. Finally, the sighting device of the invention makes it possible, as long as the optically effective surfaces are of good quality, to view in a single plane the target and the target mark.
Compared to the device disclosed in German Pat. No. 269,447, the sighting device of the invention, due to using a solid mass of glass or other material for the optical system from effective optical surface to effective optical surface in which the two frontal surfaces are arranged to have respectively the target mark and a semi-transparent coating, presents the advantage of considerably simplifying the calculation of the lens system and of reducing the cost of manufacturing. Also, by eliminating the requirement of separate, curved semi-transparent mirror surfaces on the interior of the lens body, there results a reduction of possible sources of error either in calculation or in production.
Because of the particular advantageous arrangment of the optical system of the invention, the lens frontal surfaces have a curvature of such kind and are situated at an appropriate distance from each other with the result that the light rays reflected by the target mark upon reflection upon the first surface are reflected in such a way that they merge with the rays originating from the target which are refracted by the first optical surface.
As is known, Galileo type telescopes do not provide an intermediate image with the aid of which a target mark could be projected into infinity. However, by the arrangement provided by the present invention, this is obtained in an especially simple way such that the second optically effective surface, besides its light refracting function, serves simultaneously as the support for the target mark, made of reflective material, and that the optically effective first surface is made semi-reflective by means of an appropriate coating. In such manner, the surface acts as a reflective surface at the same time as acting as a refractive surface for the light rays. The two optically effective surfaces thus have a double function which considerably reduces the number of optically effective components. By choosing an appropriate distance between the two surfaces, i.e., by choosing an appropriate actual thickness of the lens body, it is possible to have the target mark projected to infinity simultaneously with obtaining the optical telescope effect, such that the viewer sees the target and the target mark clearly in a single plane. Fulfilling both requirements is possible for every light refracting medium at a certain magnification, for example, for crown glass the magnification factor is 1.26×. In this manner, the target mark is observed with a magnification corresponding to an ordinary magnifying glass, whereby the focal length of the magnifying glass results from the predetermined dimensions between the reflecting first surface and the light defracting second surface, and is thus dependent upon the actual length of the lens mass. In the above mentioned example of using crown glass, with a thickness of glass of 30mm between the first and second surfaces a magnifying glass magnification of 10.5× results for the target mark. The target mark, or reticle, therefore needs to be provided on the second optically effective surface only in a relatively small size. Consequently, the target mark causes very little interference with sighting through the second surface, and therefore provides only a negligible loss of brightness since it is of relatively small overall size and the lines forming the reticle, or other target mark, are only a few hundredths of a millimeter in width. Finally, the reflected target mark appears to be bright relative to the light surrounding the target, which considerably improves the visibility of dark targets especially at night or at dusk.
Another advantage of the present invention is that the two optically effective surfaces have such curvature and are situated at a distance from each other such that the diameter of the exit pupil is larger than that of the pupil of the human eye. For practical purposes, the diameter of the exit pupil is in the range of 15 to 25mm, preferably 20mm.
The particularly wide exit pupil obtained by the present invention which results from, among other factors, the relatively small telescope magnification, provides very important advantages in an optical sight. Since the light originating from the target placed at infinity, after passage through the second optically effective surface emerges over the full diameter of the exit pupil parallel to the optical axis, the human eye does not have to be positioned with precision, either radially or axially. It is sufficient if the eye is located within the bundle of parallel rays emerging through the wide exit pupil. Thus, precise alignment of the eye with the target line is not required. In this respect, particularly important advantages are provided by the present invention as compared with prior art sighting devices. Aiming is rendered considerably easier and, most of all, requiring much less time and concentration. This is particularly important for firearms since it is evident that such a simplified, rapid and accurate aiming procedure, in view of the great visibility of the target as provided by the invention, is of utmost importance, especially for a chance for survival in man-to-man combat. It has also advantages for other applications, such as for geodesic transits, such advantages taking place during the aiming procedure.
In order to compensate for spherical aberration within the lens mass itself, according to the present invention, the distance between the first and second optically effective surfaces is preferably determined such that the deviation angle of any single ray over the entire diameter of the exit pupil at least at three points, especially at the optical axis and on two diametrically opposed points located at the outer limit of the exit pupil, is zero and negligibly small for any intermediary points. A relatively high precision in the parallelism of the light rays exiting through the exit pupil can be obtained with aspherical, or rotation symmetrical, optically effective surfaces. But it must be taken into consideration that obtaining aspherical surfaces with the inherent required precision desired involves correspondingly high accuracy in grinding the lens surfaces with resulting high cost in labor and production costs. Consequently, according to the present invention, spherical and optically effective lens surfaces are used which can be obtained with very high precision, but by much simpler methods than aspherical surfaces. Since the spherical surfaces, however, are optically accurate only proximate to the optical axis while showing increasing refraction errors proportionally to the distance from the optical axis toward the periphery of the lens system, increasing with the distance from the optical axis, such errors being both errors in deflection of the light beam as well as, more importantly yet, reflection errors, a corresponding correction becomes necessary. The correcting factors for the image producing errors, or aspherical aberrations, are preferably obtained by means of proper design. Consequently, the exact locations of the points of zero deviation over the diameter of the exit pupil are chosen such that the deviation errors between the zero points are smaller than the resolution factor of the human eye, as well as smaller than the scatter range, especially of hand firearms, and thus negligible. It should be also appreciated that the lens body, according to this invention, in the same manner than prescription eyeglasses, may show some chromatic aberrations which do not result in refraction.
An additional advantage of the present invention results from the fact that the lens body, preferably enclosed in a cylindrical housing, whether mounted at the rear of a firearm barrel, or in a geodesic instrument or the like, is spring mounted by means of one or several parallelly stacked flat leaf springs which are provided with an appropriate aperture along the optical axis of the lens system. Although the flat springs, as will be disclosed, provide a square aperture, it will be evident that they can be arranged such as to provide a circular aperture. The aperture provided by the mounting springs acts an an aperture or viewing window for the viewer through which the light rays emerge from the lens body towards the viewer. Consequently, when a circular aperture in the flat springs is provided, there results a circular viewing aperture or window.
The lens suspension springs are provided with mounting holes disposed two-by-two in separate planes and along axes crossing each other at a 90° angle, with a pair of mounting holes in one plane for attachment to the lens body and another pair of mounting holes for attachment to a support frame ring in turn rigidly mounted on the firearm, the geodesic transit or the like. In this manner, a free floating connection is effected between the lens body housing and the support ring which permits motion of one element relative to the other within a range determined by the spring design, and which is similar in action to a Cardan suspension.
Pre-stressing, or deflecting, of the flat springs is provided by several adjustment screws threading into the lens body barrel. The other end of the adjusting screws abuts against the support ring. In this manner, the springs between the lens barrel and the support ring are pre-loaded and the adjusting screws, by preloading the springs and acting as abutment means, control the range of possible motion of the spring suspension between the lens body and the support ring.
This arrangement also permits to adjust the optical axis of the lens body in azimuth and in elevation relative to its axes of symmetry, such as to accurately position the optical axis relative to the operational axis of the firearm or other device. Three adjustment screws are provided which are arranged relative to each other such that they are located each at an apex of a right triangle whose perpendicular sides are parallel to the axes of symmetry. For adjustment of the lens body in azimuth or in elevation, the screws at each end of the hypotenuse of the triangle are used while the third screw remains fixed. Through appropriate tightening or loosening of one of the two screws on the hypotenuse of the triangle the lens body can be precisely swiveled in elevation or azimuth within the course of the springs. The third screw at the apex of the triangle has only a holding function.
It will also be appreciated that the adjustment screws, at the same time, serve to preload the flat springs in addition to adjusting the alignment of the optical axis of the lens system, in such manner that for preloading of the flat springs all the adjustment screws are equally tightened, and, for adjusting the optical axis of the lens system, only one screw is tightened or loosened, thus causing the lens body to swivel about the axis formed by the opposite short side of the right angle triangle.
According to a further aspect of the present invention, the adjustment screws are arranged so that the geometric center of the flat springs is located within the triangle defined by the adjustment screws. Since it can be assumed that all effective and resulting forces acting upon the flat springs are applied at the geometric center of the springs, or spring center of gravity, it results, as can be readily seen, that the arrangement according to the present invention of the adjustment screws relative to the spring center of gravity provides at all times a stable balance or equilibrium, while providing an adjustment arrangement for the lens body which remains undisturbed even if a considerable motion is encountered, such as will occur with firearms having a powerful recoil.
Safe functioning and protection from adverse conditions is provided to the sighting device according to the present invention by enclosing the lens body, with appropriate clearance, in a protective tubing attached firmly to the front end of the support ring, the protective tubing extending forwardly and projecting beyond the front end face of the lens body. The protective tubing protects the lens from damages and resulting misalignments. At the same time, the protective tubing serves to screen out unwanted light.
U.S. Pat. No. 2,968,099 discloses a protective tubing for a sighting device. In the arrangement disclosed, however, the tubing is simply slipped over the outer end of the sighting device, so that unfavorable external influences affecting the tubing can also affect the sighting mechanism. Furthermore, the protective tubing is costly to manufacture. By comparison, the simple tubing provided by the present invention is not attached to the lens body itself but to the front end of the stable sturdy support ring in such manner as to provide a clearance space between the periphery of the lens body and the internal surface of the tubing. It can thus be seen that the arrangement according to the present invention prevents any external shock or vibration affecting the protective tubing from, as a rule, being transmitted to the lens body, since the tubing is attached to the lens support ring with a clearance space between the lens body and the tubing interior. A rear cover cap, also providing an aperture window, can be attached to the rear portion of the support ring, which presents the added advantage of masking any unwanted light from the ocular or eyepiece portion of the lens.
A particular advantage of the optical sight of the present invention, which at the same time provides the desired protection from unwanted outside influences, is particularly well adapted for use with firearms in which the whole optical sighting assembly is mounted within a rear extension of the firearm carrying handle, such that the lens body is aligned within a recess in the carrying handle which is parallel to the barrel of the firearm. Since the carrying handles are designed quite sturdily in view of their function, they provide, without additional expenditure, an optimum means of protection for the optical sighting device of the invention.
From the German published application No. 1,924,606 and corresponding U.S. Pat. No. 3,642,341 it is basically known that an optical sighting device may be incorporated in the handle of a firearm. In that disclosure, however, the optical sighting unit is built into that part of the handle which is usually gripped by the hand, thus making it necessary for that part to be designed quite large in order to accomodate a sighting device of large diameter. This causes the carrying handle to be higher than otherwise necessary, which presents a basic disadvantage. On the other hand, in such arrangement the space available for accomodating the sighting device within the handle is automatically limited by the size of the grip of the fingers. This in turn results in a smaller exit pupil for the sighting device which is an important disadvantage when compared to the present invention. In contrast, in the arrangement of the present invention the optical sighting device is not mounted directly in the inside of the handgrip portion of the carrying handle but, rather, in a rear extension of the carrying handle, i.e., at the portion of the handle provided with an opening forming a grip for the fingers. Thus, a carrying handle of minimum height is provided. Since the opening accomodating the fingers can be designed sufficiently high, the diameter of the exit pupil according to the present invention can be arbitrarily chosen to meet any requirement.
A further advantage of the invention is to provide a mounting or frame ring which is rigidly attached to the rear extension of the firearm carrying handle such that the rear extension of the handle houses the lens body with appropriate clearance. This arrangement provides an advantageous suspension of the lens body within the rear extension of the handle.
Another advantage of the invention consists in the rear extension of the handle extending at its forward portion considerably over the front portion of the lens body. Thus the frontal extension provides a hood or visor keeping out unwanted light without requiring additional components.
A further advantage of the present invention resides in the rear aperture window cap which is attached to the rear end of the rear extension of the carrying handle thus likewise helping to screen out unwanted light.
Further advantages of the present invention will become apparent to those skilled in the art when the following description of the best modes contemplated for practicing the invention is read in conjunction with the accompanying drawing wherein like reference numerals relate to like and equivalent parts, and in which:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic illustration, in cross section, of an optical sighting device according to the present invention as used as an optical sight for a firearm;
FIG. 2 is an enlarged view in section of the lens body portion of FIG. 1, for showing in detail the mounting and adjustment means, but provided with a modified support ring;
FIG. 3 is a transverse section along line I--I of FIG. 2;
FIG. 4 is a perspective view of a suspension spring for supporting the lens body of the invention; and
FIG. 5 is a schematic illustration of an arrangement for mounting the optical sighting device of the invention within the carrying handle of a firearm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown at FIG. 1, an optical sighting device according to the present invention comprises a single main component consisting of a cylindrical lens body 1 made of a single piece of glass or like material. The lens body 1 is provided at each of its two frontal surfaces with an optically effective surface, each designated respectively by reference numerals 2 and 3, the surface 3 further including an appropriate target mark, in the form of a reticle, for example, not shown. Light rays originating from the target, of which only a pair of edge rays 4 and 5 are shown in the drawing for the sake of clarity, penetrate the lens body 1 in the direction of the arrows, are caused to converge by the first optically active surface 2 which acts as an objective lens and, upon emerging from the lens body 1, are caused by the optically active surface 3, acting as an ocular or eyepiece, to emerge again as a beam of parallel rays. A human eye 6 located behind the sighting device in the beam of parallel light rays observes without difficulty the enlarged image of the target and, through alignment of the target image with the center of the target mark, can aim with precision at the target any device on which the sighting device is mounted, such as a firearm.
For further detailed explanation of the optical characteristics of the invention permitting it to operate as a sighting device, reference is made to FIG. 2 which represents an enlarged, detailed partial view of FIG. 1, provided with a modified sighting device support ring, as will be explained in detail hereinafter. As clearly shown at FIG. 2, the two optically effective surfaces 2 and 3 are each in form of a spherically curved surface. The first surface 2 is convex for concentrating the light rays, while the second surface 3 is concave for deflecting the concentrated light rays back to a parallel light ray beam. In addition, the surface 2 is coated with a semi-transparent, semi-reflective mirror coating, while the surface 3 serves as a support on which is placed a diffusely reflective target mark, for example in the form of a reticle.
The two optically effective surfaces 2 and 3 are formed with a curvature radius and are disposed at such distance from each other along the optical axis 7 that the light rays reflected by the target mark disposed on the surface 3, after reflection on the first surface 2, are at least partially deflected so that they coincide with the light rays originating from the target which have been deflected upon entering the lens body 1. FIG. 2 shows the trajectory of a light ray from the target mark, for the sake of better illustrating the operation of the sighting device of the invention. A light ray, such as light ray 8 originating from infinity, via the target, parallel to the optical axis 7, impinges upon the first surface 2 at an angle i of incidence relative to a perpendicular 9 to a tangent to the surface 2, and is refracted, in accordance with the laws of optics such that it leaves the surface 2 at an angle i' relative to the perpendicular 9, whereby i' is smaller than i. Simultaneously, the light impinging upon the first surface 2 illuminates the target mark on the surface 3 and the light hitting the target mark is reflected back towards the surface 2. At FIG. 2, a reflected light ray 10, originating from the target mark, is shown. The light ray 10 impinges upon the surface 2 at an angle i" relative to the perpendicular 9 and is reflected by the semi-transparent mirror surface exactly under the same angle since due to the chosen diameter of the lens body 1 the angles i' and i" are equal. Thus, the light ray 10, after reflection on the surface 2, and the light ray 8 refracted by the surface 2, coincide exactly, forming the light ray 8' which is refracted upon impinging upon the surface 3. The surface 3 has a curvature which refracts the light ray 8' in such manner that it emerges from the lens body 1 parallel to the optical axis 7. This enables the viewer to see the target and the target mark at infinity with the same clarity.
In the example of the invention here illustrated and described in which the lens body 1 is made of crown glass, the magnification of the target, at an average distance from the firearm, is 1.26×. On the other hand, the target mark is seen under a magnifying glass magnification which depends on the thickness of the lens body 1 in the direction of the optical axis 7. For a chosen thickness of 30mm the resulting magnification of the target is about 10.5×. Consequently, the target mark which is disposed on the center of the optical surface 2 need not be relatively large. Due to the magnification of the target mark and to the fact that it is made of lines having only a few hundredth of millimeter in width, the target mark in no way obstructs the view through the lens body 1 and, furthermore, the target mark as seen on the optical surface 3 results only in a negligible loss of light.
In addition, the curvatures of the surfaces 2 and 3 and the actual thickness of the lens body 1 are arranged in relation to each other so that the resulting diameter d of the exit pupil, which can be considered as the image as seen through the eyepiece, is notably larger than the pupil of the human eye 6, as shown at FIG. 1. In the example of structure illustrated the diameter d of the exit pupil is 20mm.
During viewing of the target mark as projected onto the target line, the eye of the viewer needs not be positioned precisely either radially or axially. It is sufficient if the eye of the viewer is located somewhere within the bundle of light rays defining the exit pupil. This makes the aiming procedure particularly uncomplicated and extremely rapid as far as the optical sighting device of the present invention is concerned.
For the purpose of correcting the spherical aberration the distance between the optical surfaces 2 and 3 is determined such that the deviation angle of every single ray, over the total diameter d of the exit pupil at three predetermined points, namely at a point located on the optical axis 7 and two diametrically opposed points located at the edge of the exit pupil, is zero absolutely, and in the areas between the optical axis and the edge of the exit pupil it is negligibly small. The required correction is easily obtained by way of conventional mathematical optical computation well known to those skilled in the art.
As illustrated at FIGS. 1 and 2, the lens body 1 is disposed in a cylindrical barrel or setting 11 in which it is held by means of a threaded ring 12. The barrel or setting 11 is in turn supported at its rear end by means of, for example, three parallelly disposed flat springs 13, 14 and 15, from a support ring 16 (FIG. 1) or 16' (FIG. 2) which in turn, is rigidly mounted on the firearm.
As shown more clearly by FIG. 3, the flat springs 13, 14 and 15 have a coaxial quandrangular periphery and form a coaxial quandrangular opening as viewed in the direction of the optical axis 7. The flat springs are bent in opposite directions relatively to a pair of axes of symmetry 17 and 18, disposed at an angle of 90° in separate planes, such as to provide a spring suspension having a predetermined amount of possible deflection. FIG. 4 illustrates in perspective one of such springs 13, 14 or 15. With reference to FIG. 4, it can be seen that if the axis of symmetry 18 is considered to be in the plane of the drawing, the spring 13, 14 or 15 has its sides bent downwardly such that the axis of symmetry 17 is below the plane of the drawing. Flat apertured mounting surfaces 19 and 20 are formed disposed along the axis of symmetry 17 and 18 respectively, such mounting surfaces being disposed in planes in which are located the portions of the springs farthest removed from each other.
As best shown at FIGS. 2 and 3, the springs 13, 14 and 15 are juxtaposed and function as the mounting means between the lens body 1 and the support ring 16', by means of srews 21 fastening the apertured mounting surfaces 20 on a side of the mounting ring 16', and by means of screws 22 fastening the apertured mounting surfaces 19 at the edge of the corresponding end of the lens fitting 11. The screws 21 and 22 are provided with appropriate lock washers to prevent loosening of the screws and the possible resulting misalignment of the optical sighting device of the invention due to recoil, for example, in firearms.
It can thus be seen that the lens body 1 is so suspended relative to the support ring 16' as to permit relative motion therebetween, only as limited by the spring stroke length, and which is quite similar to a Cardan suspension. The flat springs are adjustably preloaded by means of three adjustment screws 23, 24 and 25, each having an end threaded in an appropriate threaded aperture in the edge of the fitting 11 of the lens body 1. The screws 23, 24 and 25 are passed through appropriate apertures disposed in the support ring 16', and the heads of the screws, with appropriate friction washers disposed therebelow, engage the opposite surface of the ring 16', such that by rotation of the screws the lens fitting 11 may be pulled toward the mounting ring 16' (FIG. 2) or 16 (FIG. 1). It is evident that tightening of the adjustment screws 23, 24, and 25 causes a corresponding axial compressing of the flat springs 13, 14 and 15.
Furthermore, the flat springs 13, 14 and 15 are arranged in such a manner that the axes of symmetry 17 and 18, in the operational position of the firearm, are disposed respectively horizontally and vertically. The three adjustment screws 23, 24 and 25 are relatively positioned such that they define a right angle triangle having its right angle sides 26 and 27 disposed parallel respectively to the axis of symmetry 17 and to the axis of symmetry 18 of the springs.
The adjustment of the lens body 1 in elevation and azimuth relative to the mounting ring 16 or 16' is effected by the two adjusting screws 23 and 25 located on the hypotenuse 28 of the right angle triangle, while the third adjustment screw 24 remains fixed. More particularly, adjustment of the lens body in elevation is effected by means of the adjustment screw 25 whereby the lens body 1 is swung around the axis defined by the opposite shorter right angle side 26 of the triangle. On the other hand the lens body 1 is adjusted in azimuth by means of the adjustment screw 23 which causes a corresponding swinging or swiveling of the lens body about the axis defined by the other right angle side 27 of the triangle.
The recoil resulting from firing a firearm is directly opposite to the target direction. This means that the mounting ring 16 or 16' experiences a sudden acceleration to the right, as shown in the drawing, which in turn causes, in view of the inertia of the lens body 1 and the lens barrel 11, a short jerking increase of the tensile force of the adjustment screws 23, 24 and 25. Since, during this time interval, however, the change in length of the adjusting screws 23, 24 and 25 remain practically zero, the flat springs 13, 14 and 15 keep their preloaded position and no change due to load increase takes place, with the exception of the increase of the loading tension applied to the adjusting screws 23, 24 and 25, such that the adjustment remains unchanged. The adjustment screws 23, 24 and 25 are arranged so that the geometric center 7 of the flat springs 13, 14 and 15, or the spring center of gravity, is located within the triangle defined by the adjustment screws 23, 24 and 25. Thus it can be assumed that all forces acting upon and resulting from the action of the flat springs 13, 14 and 15 are applied to the spring center of gravity 7, and there results, at all times, a constant stable equilibrium of the mounting means and adjustment means for the lens body 1, such equilibrium being even maintained under strong vibrations or stress, such as caused by the recoil of a firearm.
As illustrated at FIG. 1, the lens body 1 and its barrel or setting 11 are enclosed in a protective tubing 29, with a clearance space between the lens fitting and the protective tubing, the tubing being firmly attached to the front end of the mounting ring 16 and extending beyond the front end of the lens body 1. The protective tubing 29 shields and protects the lens body 1 against adverse external conditions and against the resulting misalignment, as well as masking it against undesirable light. For the same purpose there is provided a protective cap 30 which is screwed into, or otherwise fastened to, the rear end of the support ring 16.
In the embodiment of FIG. 5, the entire optical sighting device is mounted in the interior of a posterior extension of a carrying handle 31 of the firearm, so that the lens body 1 is substantially aligned with a recess providing a finger grip which is parallel to the barrel of the firearm. In this manner, the support ring 16 of FIG. 1, or 16' of FIG. 2, or the equivalent thereof, is firmly mounted on the rear extension of the carrying handle 31 so that the extension houses the lens body 1 with appropriate peripheral clearance. In the arrangement of FIG. 5, there is thus provided an optimum of protection against the ambiant and external effects for the sighting device of the invention, together with a most advantageous suspension means for the lens body 1, thus preventing possible misalignments.
In order to exclude undesirable light, the rear extension of the carrying handle 31, which is closed around its entire periphery, extends substantially over the frontal portion of the lens body 1. For the same purpose, a protective cap 32 is mounted on the rear of the carrying handle extension 31. In every other respect, the sighting device illustrated at FIG. 5 is alike the hereinbefore described embodiment.
It is therefore readily apparent that the optical sighting device of the invention is simple in design and can be manufactured at low cost. It can be designed as an integral portion of a firearm which is simply, quickly and easily installed, and it can also be used for mounting on firearms already in existence, without any difficulty. | An optical sighting device for firearms, more particularly hand guns and the like, geodesic instruments and the like comprising a telescope-type optical system with an objective and an ocular, or eyepiece, element and provided with a target mark, such as a reticle, positioned within the optical system, which is projected onto infinity, such as to be seen in the same plane as the plane of viewing of the target. The optical system consists of a massive cylindrical lens body of transparent material which has its opposite end surfaces formed as optically effective surfaces of symmetrical curvature, the surface of the objective being convex for converging the parallel light rays emitted from the target, and the surface of the ocular being concave for re-aligning the transmitted light rays to a beam of parallel rays. The target mark, or reticle, is disposed on the surface of the ocular element, and an image of the target mark is reflected and enlarged by the surface of the objective, such surface being provided with a semi-transparent mirror surface. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
BACKGROUND
[0003] 1. Technical Field
[0004] The present invention generally relates to concrete structures and the methods for forming the same. More particularly, the present invention relates to concrete structures and forming methods that enhance the replenishment of underground water in aquifers.
[0005] 2. Description of Related Art
[0006] As is generally understood, a common source of fresh water for irrigation, human consumption, and other uses is groundwater. Usable groundwater is contained in aquifers, which are subterranean layers of permeable material such as sand and gravel that channel the flow of the groundwater. Other forms of groundwater include soil moisture, frozen soil, immobile water in low permeability bedrock, and deep geothermal water. Among the methods utilized to extract groundwater include drilling wells down to the water table, as well as removing it from springs where an aquifer intersects with the curvature of the surface of the earth.
[0007] While groundwater extraction methods are well known, much consideration has not been given to the replenishment thereof. It is not surprising that many aquifers are being overexploited, significantly depleting the supply. The most typical method of aquifer replenishment is through natural means, where precipitation on the land surface is absorbed into the soil and filtered through the earth before reaching the aquifer. However, in arid and semi-arid regions, the supply cannot be renewed as rapidly as it is being withdrawn because the natural process takes years, even centuries, to complete. It is well understood that in its equilibrium state, groundwater in aquifers support some of the weight of the overlying sediments. When aquifers are depressurized or depleted, the overall capacity is decreased, and subsidence may occur. In fact, such subsidence that occurs because of depleted aquifers is partially the reason why some cities, such as New Orleans in the state of Louisiana in the United States, are below sea level. It is well recognized that such low-lying and subsided areas have many attendant public safety and welfare problems, particularly when flooding or other like natural disasters occur.
[0008] The problem of rapid depletion is particularly compounded in developed areas such as cities and towns, where roads, buildings, and other man-made structures block the natural absorption of precipitation through permeable soil. Generally, building and paving materials such as concrete and asphalt are not porous, in that water cannot move through the Material and be absorbed into the soil. In fact, porous material would be unsuitable for construction of buildings, where internal moisture is desirably kept to a minimum. Thus, these developed areas are typically engineered with storm drainage systems whereby precipitation is channeled to a central location, marginally cleaned of debris, bacteria, and other elements harmful to the environment which were picked up along the drainage path, and carried out to the sea. Instead of allowing precipitation to absorb into the ground, modern developed areas transport almost all surface water elsewhere.
[0009] One of the methods for replenishing aquifers is described in U.S. Pat. No. 6,811,353 to Madison, which teaches a valve assembly for attachment to aquifer replenishment pipes. However, the use of such replenishment systems required frequent human intervention. Furthermore, in order for the water in the aquifer to remain clean, existing clean water had to be pumped in. Additionally, the volume of water that was able to be carried to these re-charging locations was limited, thus limiting the replenishment capacity.
[0010] Changes to paving materials have also been considered. As is well known in the art, concrete is a composite material made from aggregate and a cement binder, the most common form of concrete being Portland cement concrete. The mixture is fluid in form before curing, and after pouring, the cement begins to hydrate and gluing the other components together, resulting in a relatively impermeable stone-like material. By eliminating the aggregate of gravel and sand, the concrete formed miniature holes upon curing, resulting in porous concrete. This form of concrete, while allowing limited amounts of water to pass through, was unsuitable for paving purposes because of its reduced strength. Additionally, the aforementioned drainage systems were still required because the porous concrete was unable to handle all of the water in a typical rainfall. Structures designed to increase the strength while maintaining porosity have been attempted, whereby reinforcement in the form of rods, rebar, and/or fibers were incorporated into the structure. Nevertheless, the strength of the structure was insufficient because of the reduced internal bonding force of the concrete due to the lack of an aggregate.
[0011] Therefore, there is a need in the art for an aquifer replenishment system for collecting precipitation and absorbing the same into the pavement and the soil in the immediate vicinity. There is also a need for aquifer replenishment system that are capable of withstanding environmental stresses such as changes in temperature, as well as structural stresses such as those associated with vehicle travel. Furthermore, there is a need for an aquifer replenishment system that can be retrofitted into existing pavement structures.
BRIEF SUMMARY
[0012] In light of the foregoing problems and limitations, the present invention was conceived. In accordance with one embodiment of the present invention, an aquifer replenishing pavement is provided, which lies above soil having a sand lens above an aquifer, and a clay layer above the sand lens. The structure is comprised of: an aggregate leach field abutting the subgrade (typically comprised of clay); and a layer of suitable surface paving material such as reinforced concrete or asphalt, abutting the aggregate leach field. Additionally, one or more surface drains extend through the concrete layer, and one or more aggregate drains extend from the aggregate leach field to the sand lens. The surface drains have a higher porosity than the paving layer, and is filled with rocks. According to another aspect of the invention, leach lines having a higher porosity than the surrounding leach field are provided. The surface drains are in direct fluid communication with the leach lines, and the leach lines are in direct fluid communication with the aggregate drains.
[0013] An aquifer replenishing concrete paving method is also provided, comprising the steps of: (a) clearing and removing a top soil layer until reaching a clay layer; (b) forming one or more aggregate drains through the clay layer to a sand lens; (c) forming an aggregate leach field above the clay layer; (d) forming a pavement layer above the aggregate leach field; and (e) forming surface drains extending the entire height of the pavement layer. Additionally, forming of the aggregate leach field also includes the step of forming one or more leach lines therein.
[0014] In accordance with another embodiment of the present invention, an aquifer replenishing concrete gutter for use on a road surface with an elevated curb section is provided. The gutter is comprised of a porous concrete section having an exposed top surface in a co-planar relationship with the road surface, supported by the elevated curb section and the side surface of the road. According to another aspect of the present invention, a cut-off wall is provided to further support the porous concrete section. A bore extending from the porous concrete down to the aquifer is also provided, and is filled with rocks.
[0015] An aquifer replenishing concrete gutter formation method is provided, comprising the steps of: (a) forming a gutter section between an elevated curb section and a road surface; (b) boring a hole in the gutter section into the aquifer; (c) filling the hole with rocks; (d) filling the gutter section with porous concrete; and (e) curing the porous concrete. In accordance with another aspect of the present invention, step (a) includes removing a section of the road surface adjacent to the elevated curb section. Finally, step (a) also includes forming a cut off wall extending downwards from the road surface and offset from the elevated curb section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which:
[0017] FIG. 1 is a cross-sectional view of the surface of the earth;
[0018] FIG. 2 is a perspective cross-sectional view of a road surface aquifer replenishment system in accordance with an aspect of the present invention;
[0019] FIG. 3 is a cross-sectional view of a gutter aquifer replenishment system in accordance with an aspect of the present invention;
[0020] FIG. 4 is a cross-sectional view of a conventional road;
[0021] FIG. 5 is a cross-sectional view of a conventional road excavated for retrofitting an aquifer replenishment system in accordance with an aspect of the present invention;
[0022] FIG. 6 is a cross-sectional view of conventional road after excavation and formation of a cut-off wall in accordance with an aspect of the present invention; and
[0023] FIG. 7 is a cross sectional view of a road after excavating a bore reaching an aquifer and filling the same with rocks, and depicts the pouring of concrete into the gutter section in accordance with an aspect of the present invention.
DETAILED DESCRIPTION
[0024] The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiment of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. It is to be understood, however, that the same or equivalent functions may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.
[0025] With reference now to FIG. 1 , a cross sectional view of the earth's surface is shown. Atmosphere 30 is shown with clouds 32 releasing precipitation 34 , falling towards the ground 50 . As is well understood, ground 50 is comprised of top soil layer 52 . Underneath top soil layer 52 is clay layer 54 , and underneath that is sand lens 56 . Aquifer 60 is a layer of water, and can exist in permeable rock, permeable mixtures of gravel, and/or sand, or fractured rock 58 . Precipitation 34 falls on top soil layer 52 , and is gradually filtered of impurities by the varying layers of sand, soil, rocks, gravel, and clay as it moves through the same by gravitational force, eventually reaching aquifer 60 . In the context of the above natural features, the present invention will be described.
[0026] Referring now to FIG. 2 , a first embodiment of the present inventive concrete paving system 100 is shown. Situated above clay layer 54 is an aggregate leach field 82 comprised of sand and gravel particles. Above aggregate leach field 82 is a pavement layer 80 , which by way of example only and not of limitation, is concrete composed of Portland cement and an aggregate. Pavement layer 80 may be reinforced with any reinforcement structures known in the art such as rebar, rods and so forth for increased strength. Preferably, the reinforcement structure has the same coefficient of thermal expansion as the pavement material, for example, steel, where concrete is utilized, to prevent internal stresses in increased temperature environments. By way of example only and not of limitation, pavement layer 80 has reinforcement bars 90 . It will be appreciated by one of ordinary skill in the art that the pavement layer 80 need not be limited to architectural concrete, and asphalt and other pavement materials may be readily substituted without departing from the scope of the present invention.
[0027] Extending from the top surface to the bottom surface of pavement layer 80 are one or more surface drains 84 . Due to the fact that non-porous concrete, that is, concrete having aggregate mixed into the cement, permits little water to seep through, surface drains 84 expedite the water flow into aggregate leach field 82 . Typically, by way of example only and not of limitation, surface drains 84 are filled with rocks to prevent large debris such as leaves and trash from clogging the same.
[0028] Within aggregate leach field 82 are one or more leach lines 86 , which assist the transfer of fluids arriving through surface drains 84 . By way of example only, leach lines 86 are in direct fluid communication with surface drains 84 . Leach lines 86 have a higher porosity than the surrounding leach field 82 to enable faster transmission of fluids. Leach field 82 is also capable of absorbing water, and in fact, certain amounts are absorbed from leach lines 86 . Additional water flowing from surface drains 84 is also absorbed into leach field 82 . In this fashion, water is distributed across the entire surface area of leach field 82 , resulting in greater replenishment of the aquifer. A person of ordinary skill in the art will recognize that the leach field 82 acts as a filter by gradually removing particulates from precipitation, and resulting in cleaner water in the aquifer.
[0029] As is well understood in the art, clay has a lower porosity as compared to an aggregate of, for example, sand, gravel, or soil. In order to expedite the transmission of water into the aquifer, aggregate drains 88 extend from aggregate leach field 82 , through clay layer 54 , and into sand lens 56 . Therefore, a minimal amount of water is absorbed into the clay layer 54 , and the replenishment process is expedited.
[0030] After the water flows from leach field 82 into sand lens 56 via aggregate drains 88 , it is dispersed throughout sand lens 56 , trickling through to the aquifers in the vicinity. The water in the aquifer is thus replenished through largely natural means, namely the filtration process involved in absorbing precipitation through aggregate leach field 82 and sand lens 56 , despite the existence of a non-porous material such as concrete overlying the ground surface in the form of pavement layer 80 .
[0031] The aquifer replenishment system as described above is generally formed over previously undeveloped land, or any land that has been excavated to a clay layer 54 . Thus, surfaces that have been previously paved by other means must first be removed so that the natural water absorption mechanisms of the earth are exposed. After this has been completed, aggregate drains 88 are drilled from the exposed clay surface 54 into sand lens 56 . After filling the aggregate drains 88 with aggregate, a generally planar aggregate leach field 82 is formed. Contemporaneously, leach lines 86 are formed, and is encapsulated by the aggregate which constitutes leach field 82 . After leach field 82 is constructed, concrete reinforcements 90 are placed, and uncured concrete is poured to create pavement layer 80 .
[0032] With respect to the formation of surface drains 84 , any conventionally known methods of creating generally cylindrical openings in concrete may be employed. For example, before pouring the uncured concrete, hollow cylinders may be placed and inserted slightly into leach field 82 to prevent the concrete from flowing into the opening. Yet another example is pouring the concrete and forming a continuous layer, and drilling the concrete after curing to form surface drain 84 . It is to be understood that any method of forming surface drain 84 is contemplated as within the scope of the present invention.
[0033] With reference to FIG. 3 , a second embodiment of the aquifer replenishing system 200 is shown, including an elevated curb section 192 , a gutter section 196 , and a road pavement section 190 . Road pavement section 190 is comprised of a pavement surface 195 , which by way of example only and not of limitation, is architectural concrete, asphalt concrete, or any other paving material known in the art, and is supported by base course 194 . Base course 194 is generally comprised of larger grade aggregate, which is spread and compacted to provide a stable base. The aggregate used is typically ¾ inches in size, but can vary between ¾ inches and dust-size.
[0034] In accordance with the present invention, gutter section 196 has a porous concrete gutter 184 in which the top surface thereof is in a substantially co-planar relationship with the top surface of pavement surface 195 . Optionally, porous concrete gutter 184 is supported by base 185 which is composed of similar aggregate material as base course 194 . Furthermore, extending from optional base 185 into aquifer 60 is a rock filled bore 188 . As a person of ordinary skill in the art will recognize, a bore filled with rocks will improve the channeling of water due to its increased porosity as compared with ordinary soil. Optional base 185 and porous concrete gutter 184 is laterally reinforced by cut off walls 183 and elevated curb section 192 . The cut off walls 183 are disposed on opposing sides of the porous concrete gutter 184 and the base 185 between the elevated curve section 192 and the pavement surface 195 . It is expressly contemplated that the cut off walls 183 may be pre-cast or cast in place.
[0035] When precipitation falls upon road pavement section 190 , the water is channeled toward gutter section 196 . Porous concrete gutter 184 permits the precipitation to trickle down to aquifer 60 . When optional base 185 and rock filled bore 188 is in place, there is an additional filter effect supplementing that of the porous concrete gutter 184 . A similar result can be materialized where the water drains from the upper surface of elevated curb section 192 , or precipitation directly falls upon porous concrete gutter 184 . Please note a large surface drain may be used in lieu of the porous concrete gutter.
[0036] This embodiment is particularly beneficial where retrofitting the gutter is a more desirable solution rather than re-paving the entire road surface. In a conventional road pavement as shown in FIG. 4 , pavement surface 195 and base course 194 extend to abut elevated curb section 192 . In preparation for retrofitting gutter section 196 , a section of pavement surface 195 and base course 194 is excavated as shown in FIG. 5 , leaving a hole 197 defined by the exposed surfaces of elevated curb section 192 , base course 194 , and pavement surface 195 . This is followed by the optional step of pouring and curing a cut-off wall 183 as illustrated in FIG. 6 , which, as discussed above, serves to reinforce the gutter section 196 . One or more bores 188 are drilled down to aquifer 60 , and filled with rocks, as shown in FIG. 7 . An optional base of aggregate 185 is formed above rock filled bore 188 , and compacted by any one of well recognized techniques in the art. Finally, a volume of porous concrete mixture, that is, a concrete without sand or other aggregate material, is poured and cured, forming porous concrete gutter 184 . While recognizing the disadvantages of using porous concrete, namely, the reduced strength of the resultant structure, a person of ordinary skill in the art will also recognize that gutter section 196 sustains less stress thereupon in normal use as compared to road pavement section 190 .
[0037] The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments. | A concrete structure for replenishing an aquifer and a method for constructing the same is provided. The structure is comprised of a pavement layer with surface drains that extend through the pavement layer and into an aggregate leach field. The leach field includes leach lines spanning the leach field. An aggregate drain extends from the leach field into a sand lens. Precipitation which falls upon the structure thus flows through the surface drain, absorbed into the aggregate leach field, and transported to the aggregate drains by way of aggregate leach lines. The water is then absorbed into the sand lens, ultimately replenishing the aquifer. Existing conventional pavement structures are retrofitted by the removal of a section of the pavement, and filling the same with porous concrete. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] Not Applicable.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to beds and bed frames which have metal or wooden bed rails and to metal adjustable cross bars with legs for supporting the cross bars. While this invention is particularly applicable to full, queen, California king and king size beds which require legs on the cross bars to support -the extra width and weight of such beds and bedding, it also is applicable to twin size beds where legs may be desired.
[0004] Specifically, this invention is related to adjustable angle iron cross bars for bed rails and frames designed for use with various sized beds and to a fastener for connecting the parts of the adjustable angle iron cross bars together, which fastener has a support leg fastened thereto.
[0005] 2. Description of the Prior Art
[0006] Conventional beds and bed rails require longitudinally spaced, transversely extending wooden or metal slats extending between the side rails. The side rails tend to warp, twist outwardly or deflect under the weight of the box spring and other bedding components, which causes the box spring to sag. This especially is a problem with wider span beds and bedding, such as, queen size and king size widths, since the wider bedding is heavier as well as being wider and longer. Slats setting on angle iron or wood rails not only push the rails downwardly, but also push the rails outwardly when weight or torquing of these rails frequently cause the bed legs to split when the slot in the legs of the beds is too close to the outside edge of the leg, or cause the bed legs to split away from the end board. These slats are normally 1″ thick or less and create a sway in the box spring between one slat and the next, thereby weakening the frame of the box spring.
[0007] Prior U.S. Pat. No. 4,080,674 issued Jan. 3, 1977 discloses metal bed rails for queen size beds which eliminate the use of transverse slats and are interconnected by a centrally located angle iron rigid cross member with legs and adjustable glides. By extending the threaded glides to contact the floor they prevent the box spring from sagging and eliminate undue stress on the side rails and bed legs.
[0008] U.S. Pat. No. 5,203,039 discloses an adjustable cross bar and foldable adjustable legs. U.S. Pat. No. 5,502,852 is an improvement on the adjustable leg structure of U.S. Pat. No. 5,203,039. U.S. Pat. No. 6,209,155 is an improvement on the adjustable cross bar shown in U.S. Pat. No. 5,203,039 and U.S. Pat. No. 6,397,413 is an improvement on U.S. Pat. No. 6,209,155 in that it provides for the installation of the leg on the fastener which holds the cross bar members together.
[0009] U.S. Pat. Nos. 5,203,039; 5,502,852; 6,209,155; and 6,397,413 are owned by the assignee of this application. The present invention is an improvement on the support legs shown in the aforementioned patents in that it provides for the leg being riveted to the fastener which is a relatively inexpensive fastening technique compared to the spot welding required in U.S. Pat. No. 6,397,413. It also is fabricated at the factory and does not require assembly in the field, saving on installation costs by the installer.
BRIEF SUMMARY OF THE INVENTION
[0010] It is a primary object of the present invention to provide a cross bar construction, especially for full, king, California king, and queen size beds, which is adjustable in width and height, and which is easily and inexpensively fabricated at the factory.
[0011] Another object is to provide an adjustable cross bar construction for bed frames in which a leg is riveted to the bracket which slidingly retains the free ends of the cross bar members. These and other objects will become apparent hereinafter.
[0012] This invention comprises a bed frame cross bar having relatively expandable members and a locking bracket for retaining the expandable members in a fixed position with a leg riveted to the locking member by a relatively inexpensive and accurate technique at the place of fabrication.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] In the drawings wherein like numbers refers to like parts wherever they occur:
[0014] [0014]FIG. 1 is a perspective view of the leg and locking member which is the subject of this invention;
[0015] [0015]FIG. 2 is an end elevational view of this invention applied to two relatively slidable cross bar members;
[0016] [0016]FIG. 3 is a fragmentary front elevation view of this invention as shown in FIG. 2;
[0017] [0017]FIG. 4 is a front elevational view of the cross bar shown in FIG. 1;
[0018] [0018]FIG. 5 is a plan view of the connecting member shown in FIG. 1;
[0019] [0019]FIG. 6 is a vertical sectional view taken on line 6 - 6 of FIG. 3; and
[0020] [0020]FIG. 7 is a sectional view taken on line 7 - 7 of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The following detailed description illustrates the invention by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what we presently believe is the best mode of carrying out the invention.
[0022] This invention is an improvement on the adjustable cross bar connector shown in detail in FIG. 4 of U.S. Pat. No. 5,203,039 and identified by numerals 20 - 25 of that patent and on the connector identified by the numerals 100 et. seq. in U.S. Pat. Nos. 6,209,155 and 6,397,413. The structures of U.S. Pat. Nos. 5,203,039, 5,502,852, 6,209,155 and 6,397,413 are herein incorporated by reference to the extent necessary to define background for a completion of the present disclosure.
[0023] [0023]FIG. 3 shows a cross-bar 100 which comprises a main cross bar member 101 and an adjustable cross bar member 102 .
[0024] The main cross bar member 101 is an “L” angle, which has a horizontal flange or web 103 and a right angle vertical flange or web 104 . The vertical flange 104 terminates at 105 inwardly from the outboard edge 106 of the horizontal flange 103 . This defines a cut-out area which engages the inside of side rail 107 while the horizontal flange 103 has an opening 108 which overlaps the lip 107 a of the side rail 107 and accommodates a screw 108 a or other suitable means for fastening the main cross member 101 to the side rail 107 . The adjustable cross bar member 102 likewise has a vertical flange 109 and a horizontal flange 110 . The flanges 103 , 110 and 104 , 109 are of approximately equal size. The outboard end 111 of the adjustable cross member 102 is of similar construction to the outboard edge 106 of the main flange 101 and includes an opening 108 to accommodate a screw 108 a or other suitable fastener to attach the cross bar 102 to the side rail lip 107 a. When the side rails 107 and lips 107 a are wood, screws are used to fasten the cross bars members 101 , 102 to the lips 107 a. When the side rails 107 and lips 107 a are metal, bolts and nuts are used.
[0025] The novel bracket 10 of this invention is used to tie the cross bar members 101 and 102 together at their inboard or free ends 112 and 113 . The bracket 10 preferably is about five inches in length for a bed cross bar, but can be any length for other applications as long as it is sufficiently long to provide rigidity and strength to the extended cross bar.
[0026] The horizontal flange 103 of the cross bar member 101 has a longitudinal free edge 115 while the vertical flange 104 has a longitudinal free edge 116 . The horizontal flange 110 of the adjustable cross bar member 102 has a longitudinal free edge 117 and the vertical flange 109 has a longitudinal free edge 118 . This is more clearly shown in FIG. 2.
[0027] As seen more clearly in FIG. 1, the bracket 10 comprises right angular flanges 11 and 12 . The flange 11 is horizontal and the flange 12 depends therefrom at a right angle. The free edges of the flanges 11 and 12 are turned backwardly over the outer surfaces 11 a, 12 a of the flanges 11 , 12 to form a horizontal track 13 and a vertical track 14 , respectively. The track 13 embraces the free ends 115 and 117 of the cross bar flange members 103 , 110 and the track 14 braces the free ends 116 , 118 of the cross bar flange members 104 , 109 , respectively. This is seen in FIG. 2. This allows the members 101 , 102 to be relatively movable through the tracks 13 , 14 , thus allowing the members 101 , 102 to be sized to fit the distance between the side rails 107 .
[0028] An adjustable locking mechanism 20 is incorporated into the bracket 10 (FIG. 6) and is positioned adjacent to the flange inside surfaces 11 b and 12 b. A boss or gusset 21 is formed in the flange 12 on the inside surface 12 b thereof. The boss 21 has a rectangular base 21 a and triangular sides 21 b (FIG. 1). An opening 22 is formed in the base 21 a of the boss 21 and a Tinnerman nut 23 is positioned over the base 21 a and frictionally engages the front and backsides thereof. The Tinnerman nut 23 has legs 24 , 25 provided with openings 24 a and 25 a. The openings 24 a, 25 a are sized to mate with the boss opening 22 . The leg 25 has outwardly flared edges around the opening 25 a which act as a lock nut for an L-shaped threaded bolt or elbow 26 which is positioned through the openings 22 a, 24 a, 25 a. When the elbow 26 is tightened its end 27 engages the inside surface of the cross bar member 101 to lock the cross bar members 101 , 102 into frictional engagement with the bracket 10 .
[0029] The tracks 13 and 14 are sized to accommodate the cross bar members 101 and 102 in a relatively sliding arrangement.
[0030] When the cross bar member ends are firmly seated against the inside edges of the bed rails 107 and attached by the screws 108 a, they will resist rotation or other movement. An important aspect of this invention is that the bracket horizontal flange 11 and the cross bar member horizontal flanges 103 , 110 are aligned so that the weight of the spring, mattress and users urges them into frictional engagement and strengthens the grip of the elbow 26 against the inner surface 112 of the cross member flange 103 .
[0031] An important improvement of this application is the way the leg 30 is attached to the fastening bracket 10 . In U.S. Pat. No. 6,397,413, the leg is welded to the fastening member in any of several different ways. Spot welding is an expensive way of attaching metal parts together and requires considerable time and skill on the part of the welder. In the present application, the leg 30 is riveted to the bracket 10 . Riveting is less costly and requires less skill and is more easily automated.
[0032] The leg 30 is formed of hot rolled steel and has right angular flanges 31 and 32 . The flange 31 has rivets 33 applied to fasten the leg 30 to the leg bracket flange 12 . The rivets 33 have heads 34 which are positioned on the outside of the flange 31 and the inside of the vertical bracket flange 12 , i.e., between the flange 12 and the inside cross bar member 112 . To provide ease of engagement the rivet heads 34 and the cross bar member 112 , protrusions or dimples 35 are formed in the bracket flange 12 b. The dimples 35 are deeper than the thickness of the rivet heads 34 and therefore the cross bar members 101 , 112 slide on the tops of the dimples 35 and do not hang up on the wide flat rivet heads 34 (FIG. 7).
[0033] To facilitate securing the leg 30 to the bracket 10 , an opening 40 is formed in the bracket vertical flange track 14 (FIG. 4). It is aligned with the rivet heads 34 . The opening 40 allows access to the rivet heads 34 on the bracket 10 to facilitate the riveting process. An opening 41 is formed in the bracket horizontal flange 11 and a downwardly depending stabilizing flange 42 (FIG. 1) is formed which tends to prevent leg deformation if lateral load is applied to the leg 30 , e.g.,by dragging the leg 30 across a floor.
[0034] To facilitate installation of the Tinnerman nut 23 , an opening 45 is formed in the bracket horizontal track 13 . The opening 45 is aligned with the boss 21 . An opening 46 is formed in the horizontal flange 11 aligned with the boss 21 to also facilitate installation of the Tinnerman nut 23 .
[0035] The free end of the leg 30 has a square bracket 50 which retains a threaded plastic nut 51 which holds an extensible foot 52 which is threaded to move in and out to thereby change the length of the leg 30 and provide firm support for the cross bar.
[0036] In view of the above, it will be seen that the several objects and advantages of the present invention have been achieved and other advantageous results have been obtained.
[0037] As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | An adjustable locking mechanism incorporated in a bracket embracing laterially slidable first and second members,. said mechanism being incorporated in the bracket and having a first element engaged with the bracket and a second element engaged with the first element and movable through both the first element and the bracket into engagement with the first member to force the first member into engagement with the second member to hold said first and second members in fixed lateral relationship to each other. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an endoscope apparatus and, in particular, to a structure of an endoscope that performs automatic focus control simultaneously with acquisition of an optically enlarged image of an object to be observed.
[0003] 2. Description of the Related Art
[0004] A electronic endoscope apparatus includes an electronic endoscope (scope) having a CCD (Charge Coupled Device) and the like, which is a solid-state image pickup device, at a distal end thereof, a processor device, and a light source device, and displays an image of an object to be observed on a monitor by picking up an image of an object to be observed by the solid-state image pickup device on the basis of light illumination from the light source device and performing image processing with respect to picture signals by the processor device.
[0005] FIG. 6 shows a structure of a distal end of an endoscope with an objective lens moving mechanism in the related art which is applied to electronic endoscopes of this type. In FIG. 6 , an observation window 3 is provided at a distal end surface of a supporting section 2 of a distal end 1 of the endoscope, and a CCD 6 , which is a solid-state image pickup device, is arranged on the back side of the observation window 3 on an optical path with the intermediary of a prism 4 and a cover glass 5 . The picture signals obtained by the CCD 6 are transmitted to the processor device via a signal line 7 .
[0006] Arranged between the observation window 3 and the prism 4 is a first movable lens 9 and a second movable lens 10 which constitute an objective optical system, and hence a varifocal optical system is established. A holding frame 11 of the first movable lens 9 and a holding frame 12 of the second movable lens 10 are mounted to a cylindrical cam shaft 13 by fitting engaging holes 11 A, 12 A thereof on an outer periphery of the cam shaft 13 . The engaging hole 11 A is formed with a cam pin 15 , and the engaging hole 12 A is formed with a cam pin 16 so as to project therefrom, and the cam shaft 13 is formed with cam grooves 17 , 18 at different inclination angles with respect to the axial line thereof. The cam pin 15 is engaged with the cam groove 17 and the cam pin 16 is engaged with the cam groove 18 .
[0007] A linear transmission member 19 formed of a multicoil spring is connected to the cam haft, and the other end of the linear transmission member 19 is mounted to a motor or the like provided in an operating unit. Therefore, by rotating the cam shaft 13 via the linear transmission member 19 by driving the motor or the like, the first movable lens 9 and the second movable lens 10 move in the fore-and-aft direction in the direction of the optical axis by engagement between the cam grooves 17 , 18 and the cam pins 15 , 16 , whereby optical change in magnification power (enlargement) or the like is achieved.
[0008] On the other hand, as regards the endoscope, there exist a type in which focusing is achieved by driving a focusing lens by a rapid deformation piezoelectric actuator by operating an operating switch of an operating unit as disclosed in JP-A-6-22903.
[0009] Alternatively, as shown in JP-A-2002-263058, an endoscope having an automatic focusing mechanism is also manufactured. This automatic focusing mechanism is adapted to drive a movable lens for automatic focusing on the basis of focus estimating signals (high-frequency signals) extracted from the picture signals (predetermined distance measurement area). With the control of the automatic focusing mechanism, the automatically focused object to be observed can be observed on a monitor.
[0010] In the case of the endoscope apparatus in which the magnification power is changed optically as described in conjunction with FIG. 6 , the magnification power is changed optically (observational distance, observational depth, and focal distance or the like are variable) by moving the second movable lens 10 in association with the movement of the first movable lens 9 . In association with the change of the focal point, positional adjustment such as to reduce the distance between the object to be observed and the distal end of the electronic endoscope (scope) and correction of the focus are necessary. However, in an enlarged position, focusability is limited due to the observational depth. Therefore, if further detailed focusing can be performed automatically, an enlarged and clear image of the object to be observed can easily be acquired. In other words, in the related art, when being out of focus, it is necessary to perform focus adjustment operation by minutely moving the distal end of the endoscope for changing the distance with respect to the object to be observed, and such an operation is quite complicated.
[0011] On the other hand, since the diameter of the distal end of the endoscope is aimed to be small, an efficient structure and arrangement must be employed in order to provide an automatic focusing mechanism for performing focusing operation automatically in addition to the optical magnification power change mechanism.
SUMMARY OF THE INVENTION
[0012] In view of such problems, it is an object of the present invention to provide an endoscope apparatus in which a focused enlarged image can be acquired automatically and easily by arranging an automatic focusing mechanism efficiently in a distal end of a small diameter independently from an optical magnification power change mechanism.
[0013] In order to achieve the above-described object, the invention according to a first aspect of the invention is an endoscope apparatus comprising: an insertion section including a distal end; a power changing movable lens that makes observational magnification variable, the power changing movable lens being movably built in an objective optical system provided at the distal end; a linear transmission member that drives the power changing movable lens, the linear transmission member being disposed from a drive section provided at a position other than the insertion section to the distal end; a focus adjusting movable lens that achieves automatic focusing function, the focus adjusting movable lens being movably built in the objective optical system separately from the power changing movable lens; and an actuator (which is compact and is capable of high-velocity driving) that drives the focus adjusting movable lens, the actuator being arranged in the distal end.
[0014] The invention according to a second aspect of the invention further comprises an automatic focus control circuit that sets the focus adjusting movable lens to an initial position by the actuator when starting a focusing operation with the automatic focusing function, and controls a movement of the focus adjusting movable lens from the initial position to a focused position.
[0015] According to the structure in the first aspect of the invention, with the provision of the focus adjusting movable lens for driving with the rapid actuator separately from the power changing movable lens, fine focusing can be achieved automatically.
[0016] According to the structure in the second aspect of the invention, since the focus adjusting movable lens is set to the initial position at the time of focusing operation and the lens movement (position) is controlled from the initial position by controlling the drive pulse of the actuator or by measuring the drive time of the same, automatic focusing control is enabled without providing a specific position detection sensor.
[0017] According to the endoscope apparatus of the present invention, while the power changing movable lens is driven by the linear transmission member, the focus adjusting movable lens is driven by the compact actuator arranged in the distal end. Therefore, the automatic focusing mechanism, which is independent from the optical magnification power change mechanism, is arranged efficiently in the distal end of reduced diameter, and a focused enlarged image can be acquired automatically and easily.
[0018] According to the structure in the second aspect of the invention, since the automatic focusing control is performed without using the position detection sensor or the like, reduction of the diameter of the endoscope is advantageously achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 shows the structure of a distal end of an endoscope with a portion other than a prism and an image pickup device in cross-section taken along the line I-I in FIG. 2 ;
[0020] FIG. 2 is a drawing of the distal end of the invention when viewed from the front;
[0021] FIG. 3 is a drawing showing a structure and an operational range of a piezoelectric actuator that drives the movable lens for adjusting the focus according to the embodiment;
[0022] FIG. 4 is a drawing showing a general structure of an electronic endoscope device according to the embodiment;
[0023] FIGS. 5A and 5B are drawings showing voltage (drive pulse) waveforms for driving the piezoelectric actuator according to the embodiment; and
[0024] FIG. 6 is a cross-sectional view showing a structure of the distal end of the electronic endoscope in the related art.
DETAILED DESCRIPTION OF THE INVENTION
[0025] A structure of an electronic endoscope apparatus according to an embodiment is shown in FIG. 1 and FIG. 4 . FIG. 1 shows the structure of a distal end of an endoscope with a portion other than a prism and an image pickup device in cross-section taken along the line I-I in FIG. 2 . In FIG. 1 , an observation window (lens) 22 a, a fixed lens 22 b, a first movable lens 23 a and a second movable lens 23 b for changing the magnification power that are each configured as a varifocal lens, a fixed lens 22 c and a third movable lens 23 c for focusing are arranged in sequence from the front as an objective optical system at a distal end 20 of the electronic endoscope (scope). A CCD 26 which is a solid state image pickup device is arranged on the backside of the third movable lens 23 c with the intermediary of a prism 24 and a cover glass 25 . Signals picked up by the CCD 26 are supplied to a processor device via a circuit board 27 and a signal line 28 .
[0026] The first movable lens 23 a is held by a holding frame 30 having an engaging hole 30 A, and the second movable lens 23 b is held by a holding frame 31 having an engaging hole 31 A, and the respective lenses 23 a, 23 b are attached to a cylindrical cam shaft 33 in a state in which the engaging holes 30 A, 31 A are fitted on the outer periphery of the cam shaft 33 . The engaging hole 30 A is formed with a cam in 35 , and the engaging hole 31 A is formed with a cam pin 36 so as to project therefrom, and the cam shaft 33 is formed with cam grooves 37 , 38 at different inclination angles with respect to the axial line thereof. The cam pin 35 is engaged with the cam groove 37 , and the cam pin 36 is engaged with the cam groove 38 .
[0027] A linear transmission member 39 formed of a multicoil spring or the like is connected to the cam shaft 33 , and the other end of the linear transmission member 39 is mounted to a motor shaft of a drive unit 40 ( FIG. 4 ) provided in a operating unit. Therefore, by rotating the cam shaft 33 via the linear transmission member 39 by driving the motor, the first movable lens 23 a and the second movable lens 23 b are moved in the fore-and-aft direction by the amounts different from each other by engagement of the cam grooves 37 , 38 and the cam pins 35 , 36 , whereby the optical magnification power change (enlargement) is achieved. In other words, the first and the second movable lenses 23 a, 23 b constitutes the varifocal optical system, and the power magnification is changed optically (observational distance, observational depth, and focal distance are variable) by relatively moving in the fore-and-aft direction. In association with the change of the focal point due to the movement, positional adjustment such as to reduce the distance between the object to be observed and the distal end of the electronic endoscope is performed and then correction of focus is performed, whereby the magnification power on the monitor screen is changed (enlarged).
[0028] On the other hand, in order to drive the third movable lens 23 c for focusing, a compact and rapid actuator 42 employing a piezoelectric element is mounted to the supporting portion 43 , and an engaging hole 45 A of a holding frame 45 is movable fitted and arranged on the outer periphery of the drive shaft 42 A of the actuator 42 . In the actuator 42 , as shown in FIG. 3 , a piezoelectric element 42 B is mounted to the drive shaft 42 A, and by moving the drive shaft 42 A by the piezoelectric element 42 B in the fore-and-aft direction at varying speed, the third movable lens 23 c can be moved in the fore-and-aft direction. Other compact linear actuator such as electrostatic actuator may be used as the actuator 42 . The present invention will be further illustrated with examples below. Reference numeral 44 in FIG. 3 is a stopper for stopping the third movable lens 23 c at an initial position a 1 .
[0029] As shown in FIG. 2 , in addition to the structure shown in FIG. 1 , a light guide, illumination windows 46 A, 46 B for illuminating light supplied from the light guide, an operative instrument insertion channel 47 and so on are disposed within the distal end 20 .
[0030] FIG. 4 shows a circuit structure of the electronic endoscope apparatus according to an embodiment, which includes a CDS (relative double sampling)/AGC (automatic gain control) circuit 51 for performing relative double sampling and automatic gain control by inputting the output signal of the above-described CCD 26 . On the downstream of the CDS/AGC circuit 51 , a A/D converter 52 , a DSP (Digital Signal Processor) 53 for performing various image processing, an image memory 54 for storing one frame of image data, D/A converter 55 , and a monitor 56 are arranged.
[0031] A BPF (Band-Pass Filter) unit 58 that inputs output image signals from the A/D converter 52 and extracts high-frequency components of the picture signals (brightness signals and the like) are provided. In the BPF unit 58 , high-frequency components (two types of high-frequency detected signals) for evaluating the focus (or contrast) by two BPF having different pass bands are extracted. In addition, a micro computer 60 for generally managing the control of the electronic endoscope or the processor apparatus is provided, and an auto focus (AF) control unit 60 a of passive system is provided in the microcomputer 60 . A magnification power change switch 62 for changing the magnification power is provided in the operating unit of the electromagnetic endoscope, and the operating signals are supplied to the microcomputer 60 .
[0032] The embodiment is configured as described above. In this apparatus, the image of the object to be observed is picked up by the CCD 26 in FIG. 4 , and is subjected to the image processing by the circuit from the CDS/AGC circuit 51 to D/A converter 55 on the downstream thereof, whereby the image of the object to be observed is displayed on the screen of the monitor 56 . On the other hand, when the magnification power change switch 62 is operated, the linear transmission member 39 is rotated via the drive unit 40 , and the cam shaft 33 shown in FIG. 1 is rotated. Accordingly, the first movable lens 23 a and the second movable lens 23 b are driven and are moved to positions where desired magnification power is provided. In accordance with the change of the position of the focal point due to the movement, the positional adjustment such as to reduce the distance between the object to be observed and the distal end of the electronic endoscope and correction of the focus is performed. Consequently, the optically enlarged image to be observed is picked up by the CCD 26 , and an image of the enlarged object to be observed is displayed on the screen of the monitor 56 .
[0033] In this manner, in the state in which the object to be observed and the distal end of the electronic endoscope are close to each other, the operation for correcting the focus is complicated due to the observational depth, and in a case in which the object to be observed is pulsating, it is specifically difficult to maintain the focused state constantly. Therefore, in the embodiment, the automatic focusing control by the third movable lens 23 C for automatic focusing is performed simultaneously with the magnification power changing operation. In other words, in the BPF unit 58 in FIG. 4 , the high-frequency components which is a focal point evaluation value is extracted from the image signals, and the movement control of the third movable lens 23 c is performed by supplying the high-frequency components to the automatic focus control unit 60 a. Then, in this automatic focusing control, the third movable lens 23 c is set to an initial position at the beginning, and then movement is started from this initial position.
[0034] In FIG. 5 , a voltage waveform to be applied to the piezoelectric element 42 B of the actuator 42 is shown. FIG. 5A shows a waveform when the lens 23 c is moved backward (assuming that the side of the observation window is the front), FIG. 5B shows a waveform when the lens 23 c is moved toward the front. In other words, the lens 23 c moves backward at an initial rise where the voltage pulse is slow in FIG. 5A , and moves forward at a fall time where the voltage pulse is slow in FIG. 5B . In the embodiment, for example, the third movable lens 23 c is adapted to move one step with one saw-tooth wave in FIGS. 5A and 5B so that the third movable lens 23 c can move a range between positions a 1 to a n including n steps (10 steps, for example) as shown in FIG. 3 . In the embodiment, by applying 10 or more saw-tooth waves shown in FIG. 5A to the piezoelectric element 42 B, the third movable lens 23 c is moved to the initial position a 1 in FIG. 3 (where it is stopped by a stopper 44 ) irrespective of the current position of the third movable lens 23 c. Accordingly, the initial position a 1 of the third movable lens 23 c is specified, and hence the position detection sensor is not necessary. The above-described initial position may be a n at the front end.
[0035] Then, by moving the third movable lens 23 c in the direction in which the focal point evaluation value increases after having moved from the initial position a 1 to the predetermined position, so called climbing action is performed, and then the third movable lens 23 c is moved to the focal point by the maximum focal point evaluation value. In this manner, in the embodiment, focusing is achieved by the third movable lens which is separate from the first and second movable lenses 23 a, 23 b for optically changing the magnification power, finer focusing than in the related art is enabled.
[0036] In other words, in the above-described magnification power change function as well, focusing is achieved in a predetermined distance (range) by the first movable lens 23 a and the second movable lens 23 b. However, depending on the distance between the object to be observed and the distal end of the electronic endoscope, it may go out of focus (in particular, when the scale of enlargement is high). Therefore, the automatic focusing control functions effectively in such a case, and hence the operation and work for moving the distal end of the electronic endoscope to the position where it comes into focus is not n any longer ecessary.
[0037] The entire disclosure of each and every foreign patent application from which the benefit of foreign priority has been claimed in the present application is incorporated herein by reference, as if fully set forth. | An endoscope apparatus comprises: an insertion section including a distal end; a power changing movable lens that makes observational magnification variable, the power changing movable lens being movably built in an objective optical system provided at the distal end; a linear transmission member that drives the power changing movable lens, the linear transmission member being disposed from a drive section provided at a position other than the insertion section to the distal end; a focus adjusting movable lens that achieves automatic focusing function, the focus adjusting movable lens being movably built in the objective optical system separately from the power changing movable lens; and an actuator that drives the focus adjusting movable lens, the actuator being arranged in the distal end. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/828,153, filed May 28, 2013, titled “Tapered High Velocity Exit with Flexible Tip,” U.S. Provisional Application No. 61/928,999, filed Jan. 17, 2014, titled “Tapered High Velocity Exit with Flexible Tip.” and U.S. Provisional Application No. 61/828,169, filed May 28, 2013, titled “Wrap Around Baffle with Vented Cone Shaped Top,” and U.S. Provisional Application No. 61/828,165, filed May 28, 2013, titled “Hybrid Trap With Water Injection Cleaning.”
BACKGROUND OF THE INVENTION
[0002] (1) Field of the Invention
[0003] The present invention relates to a waterless urinals and more particularly, to waterless urinal cartridges that include a mechanism to reduce the splashing of fluids exiting the cartridge into a housing or other connected plumbing elements in order to reduce precipitant buildup and to assist in cleaning
[0004] (2) Description of Related Art
[0005] Water is a scarce and diminishing resource in many areas of the world. It is widely recognized that more must be done to conserve its usage as populations grow and climates change. Water conserving products are becoming increasingly important not only for quality of human life but also for sanitary and subsistence reasons.
[0006] There have been many water conserving measures taken across the world in an effort to deal with limited and diminishing resources. Many municipalities have come up with rationing plans. Others have invested in waste-water recycling treatment and re-use.
[0007] There have also been many water conserving products introduced to the market place. These products are becoming more widely used by the industry and home owners as regulations and the rising cost of water usage drive the need for change. Non-flushing urinal designs use far less water than traditional urinals, saving up to 40,000 gallons of water a year from a single urinal. Non-flushing urinals generally comprise three major components: a porcelain urinal, a housing, and a cartridge. The porcelain urinal component is very similar to that of a traditional urinal. The housing replaces a traditional P-trap which normally would connect a urinal to a building's plumbing. Thus, the housing sits in-line between the building's plumbing and the bottom of the urinal where the drain pipe would normally connect. The cartridge fits in the housing and can be removed for servicing and replacement.
[0008] There are two types of cartridges for non-flushing urinals: liquid trap style cartridges and mechanical trap style cartridges. The liquid trap style cartridge serves two purposes. First, it acts as a barrier from sewer gasses and odors coming into the restroom. Second, it acts as a filer removing some of the solids that precipitate from human urine (urine is a super saturated liquid). Human urine is an aqueous solution of greater than 95% water, with the remaining constituents, in order of decreasing concentration, urea 9.3 g/L, chloride 1.87 g/L, sodium 1.17 g/L, potassium 0.750 g/L creatinine 0.670 g/L and other dissolved ions, inorganic and organic compounds, according to the NASA Contractor Report No. NASA CR-1802, D. F. Putnam, July 1971. The liquid trap style cartridge works by using two mechanisms. First, urine fills the P-trap of the cartridge forming a barrier against the sewer gasses—just as water does in a traditional P-trapped urinal. Second, a layer of low density fluid, such as oil, is placed in the trap so that it floats on top of the urine. This floating oil forms a barrier keeping unpleasant urine smells from entering the bathroom. As a user urinates into the urinal, fresh urine enters the cartridge, sinks through the floating oil barrier, and presses old urine out of the trap and out through the housing exit tube and into the building's plumbing.
[0009] The mechanical trap style non-flushing urinals work in a slightly different manner. All components are similar to the above mentioned liquid trap style of non-flushing urinal except for the cartridge. In this case, the liquid sealant is replaced with some form of a valve that allows urine to go through, while blocking gas and odor from escaping back through the system and into the restroom. An example of this trap is one made by Liquidbreaker and subject of U.S. Pat. No. 7,900,288. In this model two silicone valves are used that rest on plastic seats. When urine flows down on top of the silicon valve at the center of the cartridge, the valve is opened by the weight of the urine. When the urine drips off the valve and into the housing, the valve closes sealing out gasses.
[0010] Although there are some significant water-saving benefits from using non-flushing urinals, there are also some drawbacks. One of the most significant is the formation of Struvite in the pipes, housing, and on the mechanical valve components of the mechanical type cartridge. Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NHI4MgPO4.6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platey mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid.
[0011] While flushing urinals also produce buildup in the pipes, it is found to be more of a hard calcified nature. With non-flushing urinals, it has been found that struvite formation is more common; particularly in areas of slow velocity flows or high splash. The struvite builds up mostly in the leg from the urinal to the building's down pipes in both the mechanical and the liquid trap non-flushing systems unless they are regularly flushed out with water—the building's down pipes receive water from other sources in the building and are thus often rinsed. Struvite also tends to build up in the bottom of the urinal housing, leaving a very unpleasant odor and appearance. This makes changing the cartridge an unpleasant chore for maintenance staff members. When pipes are clogged, they must be snaked out. This can be a difficult and unpleasant process as well.
[0012] Struvite also builds up in areas prone to splashing; for example the area underneath the exit of the cartridge. The splashing of urine causes solids to precipitate out of the urine and significant buildup can occur. Additionally, as noted above, struvite tends to build up where urine flow is slow or still. Prior art non-flushing urinal and trap designs suffer from splashing and/or slow flow and as a result, they tend to build up struvite deposits quickly. Increasing velocity of the flow, while minimizing the splash that occurs as the urine transfers from the cartridge or trap to the housing could provide significant improvements over the prior art by diminishing struvite formation.
[0013] For the foregoing reasons, it would be desirable to produce a better non-flushing urinal solution; one in which less struvite is formed, especially in the area immediately around the transition from the cartridge or trap mechanism and the housing or plumbing entrance. The present invention overcomes these problems and provides a mechanism to both reduce the splashing of and increase the velocity of urine exiting a non-flush urinal cartridge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The objects, features and advantages of the present invention will be apparent from the following detailed descriptions of the various aspects of the invention in conjunction with reference to the following drawings, where:
[0015] FIGS. 1A-1C is a set of illustrations depicting a prior art cartridge, similar to the one manufactured and marketed by Falcon Waterfree Technology model C1M2+, in left (side), front, and back views;
[0016] FIG. 2 is a top view illustration depicting a prior art cartridge, similar to the one manufactured and marketed by Falcon Waterfree Technology model C1M2+, set in a prior art housing;
[0017] FIG. 3 is an illustration of a cutaway side view of a prior art housing, with a prior art cartridge installed and the arrows depicting the flow of fluid through the cartridge and into the housing;
[0018] FIGS. 4A and 4B are illustrations of a top view of a prior art cartridge and a cross-section of the cartridge taken just above the overflow level;
[0019] FIG. 5 is a side view illustration of a cartridge with an anti-splash exit, according to the present invention;
[0020] FIG. 6 is a front view illustration of a cartridge showing a cartridge exit with an anti-splash exit and wipers on either side of a discharge section at the exit, according to the present invention;
[0021] FIG. 7 is an isometric view illustration of a cartridge showing an anti-splash exit and wipers on either side of a discharge section at the exit, according to the present invention;
[0022] FIG. 8 is a cutaway side view illustration of the same cartridge shown in FIG. 7 , according to the present invention;
[0023] FIG. 9 is a side view illustration of a housing body and a housing exit tube, according to the present invention;
[0024] FIG. 10 is a cutaway side view illustration of the housing from FIG. 9 , according to the present invention;
[0025] FIG. 11 is a front view cross section illustration of a housing as shown in FIG. 9 , cutaway along the line B-B and rotated 90 degrees, according to the present invention;
[0026] FIG. 12 is an illustration of a cutaway front view of the housing as seen in FIG. 11 , with a non-cutaway cartridge with the present invention, as it is first inserted and before it is turned and locked in position according to the present invention;
[0027] FIG. 13 is a cutaway side view illustration of the same cartridge shown in FIGS. 5-8 , now placed in a housing, according to the present invention;
[0028] FIG. 14 is a cutaway side view illustration of the cartridge shown in FIG. 13 , with the cartridge shown during the process of insertion, according to the present invention;
[0029] FIG. 15 is an illustration of a cutaway side view of a cartridge and a housing, with the arrows depicting the fluid path through the cartridge, according to the present invention;
[0030] FIGS. 16A and 16B are the top view illustrations of a central inlet cartridge and a cross section from the same top view of the same cartridge, according to the present invention;
[0031] FIG. 17 is an illustration of a blown-up side cutaway view and a front view of a pour spout, according to the present invention;
[0032] FIG. 18 is an illustration of a blown-up side cutaway view and a front view of a pour spout flexible via a hinge area, according to the present invention;
[0033] FIGS. 19A and 19B are illustrations of a blown-up side cutaway view of an anti-splash exit capable of use with both side exit and down exit prior art housings, according to the present invention;
[0034] FIG. 20 is an illustration of a blown-up cross section of an anti-splash wiper which runs from the top of the spout or just above the base of the bottom of the cartridge to just below the overflow, according to the present invention;
[0035] FIG. 21 is an illustration of a cutaway side view of a mechanical trap version of the present invention incorporating a splash reducing exit, where an exit back wall is tiled away from the vertical axis and the exit is “U”-shaped so that fluid will centralize on the exit back wall, according to the present invention; and
[0036] FIGS. 22A and 22B are illustrations of a cartridge shown in a side view in FIG. 22A and a top cross-sectional view in FIG. 22B , where multiple wipers are provided on the cartridge wall and converge toward the exit drip edge of the cartridge to direct urine flow, according to the present invention.
SUMMARY OF THE INVENTION
[0037] The present invention relates to a waterless urinals and more particularly, to waterless urinal cartridges that include a mechanism to reduce the splashing of fluids exiting the cartridge into a housing or other connected plumbing elements in order to reduce precipitant buildup and to assist in cleaning.
[0038] In a first aspect, the present invention comprises a fluid exit portion for a splash-reducing urinal cartridge, where the exit portion includes a splash reducer for causing the fluid to exit the cartridge in a splash-reduced manner.
[0039] In another aspect, the splash reducer is a spout which may include a tapered exit area.
[0040] In still another aspect, the spout has converging fins that assist in urging fluid to collect in a progressively narrower channel.
[0041] In yet another aspect, the splash reducer is configured such that when the cartridge is installed in a urinal, the splash reducer urges fluid exiting the cartridge to flow in a direction selected from a group consisting of substantially parallel to an exit of a housing into which the cartridge is installed and proximate the splash reducer; and substantially parallel to building plumbing proximate the splash reducer; whereby the fluid exits the cartridge in a splash-reduced manner.
[0042] In a further aspect, the splash reducer is adjustable in a manner selected from a group consisting of being formed of a flexible material and being hinged with respect to a portion of the cartridge; thereby causing the cartridge to be easier to install
[0043] In a still further aspect, the splash reducer includes a fluid exit portion. When the cartridge is installed in a housing the fluid exit portion resides in an location selected from a group consisting of below a bottom portion of the cartridge and below the bottom portion of the housing.
[0044] In a yet further aspect, the splash reducer further compromises a fluid flow surface for receiving flowing fluid and where the fluid flow surface is coated with a hydrophobic coating
[0045] In another aspect, the splash reducer further comprises a fluid flow surface for receiving flowing fluid. The exit portion further comprises an exit wall for delivering fluid from the cartridge to the splash reducer such that fluid flowing from the exit wall encounters the splash reducer in a direction substantially parallel to the fluid flow surface at a location where the flowing fluid encounters the fluid flow surface. Thus, when fluid flows through the exit portion, the fluid handoff between the exit wall and the splash reducer is splash-reduced.
[0046] In yet another aspect, the present invention comprises a spout formed to increase the velocity of fluid exiting therefrom. The spout may be progressively tapered and may be configured to direct the fluid exiting therefrom toward a desired target.
[0047] Finally, as can be appreciated by one in the art, the present invention also comprises a method for forming and using the invention described herein.
DETAILED DESCRIPTION
[0048] The present invention relates to a waterless urinals and more particularly, to waterless urinal cartridges that include a mechanism to reduce the splashing of fluids exiting the cartridge into a housing or other connected plumbing elements in order to reduce precipitant buildup and to assist in cleaning.
[0049] The following description is presented to enable one of ordinary skill in the an to make and use the invention and to incorporate it in the context of particular applications. Various modifications, as well as a variety of uses in different applications will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to a wide range of embodiments. For example, the individual components described may be formed as discrete parts or integrated together as a single unit. Thus, the present invention is not intended to be limited to the embodiments presented, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
[0050] In the following detailed description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without necessarily being limited to these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the present invention.
[0051] The reader's attention is directed to all papers and documents which are filed concurrently with this specification and which are open to public inspection with this specification, and the contents of al such papers and documents are incorporated herein by reference. All the features disclosed in this specification, (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[0052] Furthermore, any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. Section 112, Paragraph 6. In particular, the use of “step of” or “act of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. 112, Paragraph 6.
[0053] Before describing the invention in detail, an introduction is provided to give the reader a general understanding of the present invention. Next, a description of various aspects of the present invention is provided to give an understanding of the specific details.
[0054] (1) Introduction
[0055] Non-flushing urinals use virtually no water, relying on one of two types of traps to seal out gas and odor, the first is a mechanical trap with a mechanical odor barrier, and the second is a liquid trap with a lighter-than-wastewater liquid barrier. The present invention is intended to overcome many of the shortcomings associated with both types of traps; an example being minimizing the buildup of struvite that tends to occur in the housing and the immediate drain pipe leg that connects the housing to the building's plumbing system by increasing the velocity of the flow and diminishing the splash of effluent which causes the formation of struvite.
[0056] The present invention accomplishes this in two ways. First, the path of the liquid effluent is constricted as it approaches the housing or building's drainage pipe. This constriction has the effect of increasing the exit fluid velocity. Second, it utilizes a malleable pour spout that can move out of the way during insertion (e.g., by flexing or hinging), then move back to is original configuration once insertion is completed. This is important because most housings currently in the market and already installed to accept a replacement cartridge have a trough area. This trough area can be an advantage as it keeps sewer backwash from entering the housing body and helps fluids drain away from the housing However, in current systems, the trough area is generally around ½ to ¾ inches distant from the cartridge exit/drip edge, allowing fluids to splash which results in greater struvite buildup.
[0057] In order to clearly understand the benefits of the present invention, first features of current systems are presented. For clarity, reference numbers of elements referred to in the prior art figures are affixed with “-P.” Corresponding similar elements in figures pertinent to the present invention are not affixed. Thus, for example, reference number 100 -P is used to indicate a cartridge housing in prior art figures, whereas reference number 100 is used to indicate a similar element in figures used to show aspects of the present invention.
[0058] An example of the exterior of a prior art cartridge 100 -P is presented in FIGS. 1A to 1C . As shown in FIG. 1A , the cartridge 100 -P includes a cartridge inlet 102 -P for receiving incoming fluids and a cartridge exit 104 -P for passing fluids out of the cartridge. The cartridge 100 -P also includes atop wall flange 106 -P for sealing the cartridge within a housing or a urinal (not shown). The cartridge 100 -P further includes a cartridge side wall 108 -P, that generally separates an exterior of the cartridge 100 -P from an interior of the cartridge, as well as a locking tine 110 -P for locking the cartridge 100 -P within a housing or a urinal (again, not shown) and a bottom wall 112 -P. The same exterior of the cartridge 100 -P is shown in FIG. 1B in a front view and in FIG. 1C in a back view.
[0059] The same prior art cartridge 100 -P is shown in FIG. 2 from a top view. In this view, the cartridge 100 -P is shown inserted into a housing body 200 -P having a housing flange 202 -P. The cartridge exit 104 -P (not shown) is aligned with a housing exit tube 204 -P so that fluid entering the cartridge 100 -P through the cartridge inlet 102 -P and passing through the cartridge 100 -P exits into the housing exit tube 204 -P and then further into a building's plumbing (not shown).
[0060] A cutaway cross-section side view of the cartridge 100 -P is shown in FIG. 3 , showing the interior components of the cartridge 100 -P. After entering the cartridge 100 -P through the cartridge inlet 102 -P, urine passes through a fluid barrier layer 300 -P having a fluid level 302 -P and into an inlet compartment 304 -P which resides beneath a cartridge ceiling 306 -P. The inlet compartment 304 -P is separated from an outlet compartment 308 -P by a vertical separator 312 -P. As urine flows through the cartridge 100 -P, it passes through the inlet compartment 304 -P, over a baffle 310 -P and builds up within the cartridge 100 -P, it rises within the outlet compartment 308 -P, passing through a sealant layer 314 -P, passing from a first side 316 A-P of an outlet compartment vertical separator 316 -P to a second side 316 B-P of the outlet compartment vertical separator 316 -P upon reaching an overflow level 318 -P. After passing over the outlet compartment vertical separator 316 -P, the urine enters a discharge section 320 -P where it flows down the second side 316 B-P of the outlet compartment vertical separator 316 -P until it reaches an exit drip edge 322 -P. From there, the urine drips or flows (depending on the volume) into a trough portion 324 -P of a housing bottom 326 -P. As urine falls across the gap C, between the exit drip edge 322 -P and the surface of the trough portion 324 -P, the falling urine results in struvite causing splashes 328 -P. Note that the cartridge 100 -P is shown sealed within the housing 220 -P by use of an O-ring 330 -P.
[0061] A top view of a prior art cartridge 100 -P is shown in FIG. 4A and a cross-section of the cartridge 100 -P taken just above the overflow level 318 -P is shown in FIG. 4B , looking down into the cartridge 100 -P. The splashing and resulting struvite buildup in cartridges 100 -P such as that just described is a major downside to such devices, resulting in greater replacement frequency and higher maintenance costs.
[0062] (2) Details of the Invention
[0063] The present invention teaches an improved cartridge with a fluid exit portion configured to reduce splashing of and/or increase the velocity of urine exiting the cartridge into a housing and/or a building's plumbing. A side view of a cartridge 100 according to the present invention is shown in FIG. 5 . Similar to the prior art cartridge 100 -P described previously, this cartridge comprises a cartridge inlet 102 and a cartridge exit 104 with a top wall flange 106 formed about the cartridge inlet 102 . The cartridge 100 further comprises an O-ring 330 provided about the top wall flange 106 to seal the cartridge 100 within a housing (not shown). Locking tines 110 are disposed about the exterior of the cartridge side wall 108 to lock the cartridge 100 within the housing (again, not shown). The cartridge 100 also includes a bottom wall 112 . This version of the cartridge 100 further comprises a cartridge exit 104 having a pour spout 500 configured to conform with a housing (not shown) in order to minimize the distance (gap) between the exit drip edge 322 and the housing such that dripping is minimized. One or more wipers 502 are disposed about the cartridge wall 108 . The wipers 502 protrude from the cartridge wall so that they can interact with the inside of a housing wal and wipe it clean as well as keep splash from getting inside of the housing when the cartridge 100 is inserted into the housing and during use.
[0064] It is desirable that the wipers 502 are made from a compliant material that can deform when it touches the inside of the housing wall Non-limiting examples of materials used in pluming that are flexible and would be good for making the wipers 502 include thermoplastic polyurethane (TPU), thermoplastic elastomers (TPE), and silicon. The wipers 502 can be attached with the cartridge 100 in a variety of ways, a non-limiting example includes injection molding them directly onto the cartridge (counting on both a mechanical and a molecular bond). This is a common process known as dual-injection or co-injection and it will be understood by anyone skilled in the art of injection molding Another non-limiting example of ways to attach the wipers 502 includes injection molding the wipers and then bonding them to the cartridge 100 . This is accomplished in the post process using an appropriate resin capable of bonding the wiper material to the cartridge material. A still further non-limiting example of a way to attach the wipers 502 to the cartridge 100 is through welding using high frequency or other means to melt the two surfaces together.
[0065] A rear view of the cartridge 100 of FIG. 5 is shown in FIG. 6 in side view and in FIG. 7 in an isometric view. In both of these figures, the pour spout 500 can be seen narrowing toward the exit drip edge 322 . This assists in accelerating urine as it exits the cartridge 100 , helping to prevent precipitation of struvite. Also, in both figures, the cartridge 100 can be seen having two wipers 502 , which is a desirable configuration.
[0066] The cartridge 100 of FIG. 5 is further shown in a cutaway view in FIG. 8 . As with the prior art cartridge 100 -P, this cartridge 100 comprises a cartridge inlet 102 for receiving urine. In this example, a vent 800 is disposed proximate the cartridge inlet 102 . Urine passes through the cartridge inlet 102 into a throat portion 802 and into an inlet compartment 304 which lies within the cartridge between a cartridge side wall 108 and a vertical separator 312 , roughly above a baffle 310 and beneath a cartridge ceiling 306 . The cartridge 100 further comprises a locking tine 110 for securing the cartridge 100 within a housing (not shown) as well as an O-ring 330 proximate a top wall flange 106 for creating a fluid-tight seal with the housing (again, not shown). As the urine flows through the cartridge 100 , it passes between the baffle 310 and a bottom wall 112 , into an outlet compartment 308 , where it rises along an outlet compartment vertical separator first side 316 A to an overflow level 318 , where it flows over to an outlet compartment vertical separator second side 316 B. An overflow gap 804 is formed above the outlet compartment vertical separator 316 to enable urine to pass over the outlet compartment vertical separator 316 and into a discharge section 320 . According to the present invention, the outlet compartment vertical separator 316 may be angled to permit urine to flow with minimal disturbance. Also according to the present invention, a pour spout 500 is formed at proximate the bottom of the outlet compartment vertical separator 316 at the cartridge exit 104 for directing the urine from the exit drip edge 322 of the pour spout 500 into a housing (not shown) or into a building's plumbing with minimal splashing at the interface therebetween (thus minimizing struvite precipitation). Also, at least one wiper 502 is formed proximate the discharge section 320 of the cartridge 100 .
[0067] An external side view of a housing body 200 for receiving a cartridge 100 according to the present invention is presented in FIG. 9 . The housing comprises a housing flange 202 that, when in use forms a fluid-tight seal with a urinal body (typically porcelain, not shown). As shown, the housing body 200 further comprises a housing trough 324 for receiving urine from the drip edge of the pour spout of a cartridge. After passing through the housing trough 324 , urine continues to move through a housing exit tube 204 and then into a connected plumbing system (not shown).
[0068] A cross-sectional cutaway side view of the housing body 200 of FIG. 9 is shown in FIG. 10 . In this case, locking tine keyways 1000 are visible. The locking tine keyways 1000 are configured to connect with the locking tines 110 of the cartridge 100 (not shown) to retain the cartridge 100 securely within the housing body 200 . A front view cross-sectional view of the housing body 200 of FIG. 10 is shown in FIG. 11 . In this figure, it is apparent that a housing bottom 326 resides above a bottom of the housing exit tube 204 , which is generally sloped downward to permit urine to flow out of the housing body 200 .
[0069] A front cross-sectional view of the housing body 200 of FIG. 10 is shown in FIG. 12 with an external view of the cartridge 100 of FIG. 5 inserted therein. In particular, this figure shows the configuration of the cartridge 100 and the housing body 200 when the cartridge 100 is first inserted therein. In order to connect the locking tines 110 of the cartridge 100 with the locking tine keyways 1000 of the housing body 200 , cartridge 100 is inserted into the housing body 200 without the pour spout 500 being in-line with the housing exit tube 204 (and thus, miss-aligned with respect to the housing trough 324 ). As shown, the pour spout 500 is compliant with regard to the interior of the housing body 200 during insertion and then, as the cartridge 100 is rotated so that the pour spout 500 aligns with the housing trough 324 , the pour spout 500 changes in configuration to minimize the splashing/dripping of urine between the exit drip edge 322 of the pour spout 500 and the housing body 200 . This can be accomplished in many ways, non-limiting examples of which include forming the pour spout 500 of a flexible material so that it flexes as the cartridge 100 is inserted into the housing body 200 and then regains a shape the splashing/dripping of urine between the exit drip edge 322 of the pour spout 500 and the housing body 200 ; and hinging the pour spout 500 so that it moves as the cartridge 100 is inserted into the housing body 200 and then moves back into a configuration that minimizes the splashing/dripping of urine between the exit drip edge 322 of the pour spout 500 and the housing body 200 .
[0070] A side cross-sectional view of the housing body of FIG. 10 is shown in FIG. 13 with a cross-sectional view of the cartridge 100 of FIG. 8 inserted therein after the cartridge 100 has been turned so that the locking tines 110 of the cartridge 100 engage with the locking tine keyways 1000 of the housing 200 . In this case, the pour spout 500 has expanded so that the exit drip edge 322 is very close to the housing trough 324 in order to minimize the distance C and thus minimize the splashing of urine as it contacts the housing trough 324 .
[0071] A side cross-sectional view of the housing body 200 of FIG. 10 is shown in FIG. 14 with an external view of the cartridge 100 of FIG. 5 therein. In this case, the cartridge 100 is in the process of being inserted into the housing 200 , prior to the locking tine 100 of the cartridge reaching the full depth and interlocking within its counterpart, the locking tine keyway 1000 . The housing body 200 has been cutaway enough to show how the pour spout 500 interferes with the bottom of the housing body 200 . This is because the housing trough 324 is only in the central portion of the housing body 200 , aligned with the housing exit tube 204 ; and thus, the housing trough 324 does not extend along the entire bottom of the housing body 200 . The pour spout 500 can be seen deforming to allow insertion of the cartridge 100 into the housing body 200 . The pour spout 500 is formed of a flexible material, which allows the pour spout 500 to deform or flex out of the way when it contacts the housing body 200 prior to being twisted fully into place as was shown in FIG. 13 . By forming the pour spout 500 so that it can deform or flex out of the way when it comes into contact with the housing body 200 , it can be elongated so that it fits deeply into the housing trough 324 as was shown in FIG. 13 , while still permitting the cartridge 100 to use a twisting method of insertion and locking.
[0072] When the cartridge 100 needs to be replaced or when the system of the present invention is initially installed, maintenance personnel will place the cartridge 100 into the housing body 200 and rotate the cartridge 100 until the locking tines 110 of the cartridge 100 fully engage the locking tine keyways 1000 of the housing body 200 . In the process of rotation, the wipers 502 will clear off at least some wastewater buildup on the inside of the housing body 200 . Upon full engagement, the wipers 502 prevent splash and restrain wastewater from leaving the discharge section 320 and the housing exit tube 204 .
[0073] The cutaway view shown in FIG. 13 is shown again in FIG. 15 with arrows showing the fluid path through the cartridge. Effluent (also referred to as urine or wastewater) enters the cartridge 100 through the inlet 102 and passes through the throat 802 and into the inlet compartment 304 . The liquid then flows around and underneath the baffle 310 and enters the outlet compartment 308 , and then rises until it goes over the top of the overflow 318 . The liquid then flows down the cartridge exit 104 which has a tapered and generally U-shape which causes the liquid to stay mostly central as it descends down the cartridge exit 104 . The fluid eventually enters the spout 500 at the bottom of the cartridge exit 104 and is diverted to a substantially horizontal direction as it exits the cartridge 100 and enters the housing exit tube 204 . The exit drip edge 322 is only a few millimeters away from the trough 324 , as indicated by the distance C. The distance C can be brought to zero if desired, as the soft pour spout 500 can deflect slightly to create a seal with the trough 324 , leaving no distance for splashing to occur between the pour spout 500 and the trough 324 .
[0074] Still referring to FIG. 15 , when the cartridge 100 is in use, a user and the shape of the attached urinal (not shown) will direct the urine toward the cartridge 100 . The downward slopes created by the top wall flange 106 guide the urine through the inlet 102 and the throat 802 and into the inlet compartment 304 . In the case where the cartridge uses a liquid sealant, the urine will also pass through and beneath a liquid sealant layer present within the cartridge 100 , which blocks odors from the sewer and from the wastewater itself from entering the restroom. As more urine enters the inlet compartment 304 , older urine is forced under the baffle 310 , into the outlet compartment 308 , and over the outlet compartment vertical separator 316 , into the discharge section 320 . Since this portion (the outlet compartment 308 and beyond) of the cartridge 100 would essentially be the same whether a mechanical trap system or a liquid barrier system is employed, only the liquid system is discussed. In prior art units, at this stage the wastewater would fall straight, creating a splashing area and depositing struvite and other undesirable precipitants. According to the present invention, the cartridge exit 104 is tiled off the vertical axis, as shown by the angle between the vertical separator 316 and the line A-A. For this reason, the wastewater stays in contact with the cartridge exit 104 . The cartridge exit 104 is generally U-shaped, which helps to centralize the fluid. About the overflow level 318 , the flow area is also generally U-shaped, with its outermost edges being higher than the base.
[0075] A top view of the cartridge 100 of FIG. 8 is shown in FIG. 16A and a cross-sectional view of the same cartridge 100 taken just below the ceiling 306 is shown in FIG. 16B . The cartridge 100 has a baffle 310 and an inlet compartment 304 which surrounds an outlet compartment 308 . The cartridge exit 104 has a generally U-shaped cross section which serves to centralize fluid as it passes the overflow level 318 .
[0076] The cartridge 100 and the housing 200 of FIG. 15 are shown in FIG. 17 along with sample dimensions for the pour spout 500 . Both a front view and a side cross-sectional view of the pour spout 500 are shown within the dotted line circle. The pour spout 500 can be made to flex in any number of ways. In this version, the pour spout 500 is flexible due to being formed from a compliant material with a memory that can deform when it touches the housing bottom 326 and then returns to its original form when the cartridge 100 is rotated and locked within the housing 200 such that the pour spout 500 is aligned with the housing trough 324 . Non-limiting examples of materials used in plumbing that are flexible and would be good for making the pour spout 500 include thermoplastic polyurethane (TPU), thermoplastic elastomers (TPE), and silicon. The pour spout 500 can be attached with the cartridge 100 in a variety of ways, a non-limiting example includes injection molding them directly onto the cartridge (counting on both a mechanical and a molecular bond). This is a common process known as dual-injection or co-injection and it will be understood by anyone skilled in the art of injection molding. Simply stated, a second material is injected over the first material and can be injected through holes, into a negative draft, or on to a textured surface, to help increase the bonding strength. Another non-limiting example of ways to attach the pour spout 500 include injection molding the wipers and then bonding them to the cartridge 100 in a post process, using the appropriate resin capable of bonding the wiper material to the cartridge material A still further non-limiting example of a way to attach the pour spout 500 to the cartridge 100 is through welding using high frequency or other means to melt the two surfaces together.
[0077] The cartridge 100 and the housing 200 of FIG. 15 are shown in FIG. 18 along with sample dimensions for another version of the pour spout 500 . In this version, the pour spout 500 is able to flex via a hinge area 1800 . A front view and a cross-sectional side view are shown within the dotted line circle. As a non-limiting example, the pour spout 500 may be formed from a similar material as the cartridge 100 , with the hinge area 1800 connecting the pour spout 500 with the cartridge 100 . The hinge area 1800 is shaded to indicate the flexible region. Any region large enough and flexible enough to allow the spout to fold out of the way when inserted into the housing is sufficient. In use, the pouring spout 500 touches the housing bottom 326 and the hinge area 1800 allows the pouring spout 500 to flex out of the way until it is aligned with the trough area 324 . Non-limiting examples of materials used in plumbing that are flexible and would be good for making this version of the pour spout 500 again include thermoplastic polyurethane (TPU), thermoplastic elastomers (TPE), and silicon. The hinge material can be injection molded directly on to the cartridge 100 and the spout 500 to connect the two together. This can be done using either a mechanical and/or a molecular bond. This is a common process known as dual injection or co-injection and it will be understood by anyone skied in the art of injection molding Again, simply stated, a second material is injected over the first material and can be injected through holes, into a negative draft, or on to a textured surface, to help increase the bonding strength. The pour spout can also be injection molded, then bonded on to the cartridge in a post process, using the appropriate resin capable of bonding the pour spout material to the hinge material and the hinge material to the cartridge material. The pour spout can also be welded to the hinge, and the hinge to the cartridge using high frequency or other means to melt the two surfaces together. Any of these processes can be combined to work in conjunction with each other as is common in the manufacturing of plastic components.
[0078] The pour spout 500 has elevated walls forming a channel of decreasing width, which both directs and increases the velocity of wastewater passing out of the cartridge 100 and into the housing exit tube 204 (which, in turn, is connected with a building's plumbing; not shown). As can be seen in FIGS. 17 and 18 , desirable dimensions for the pour spout 500 include a tip width 1802 of approximately 4 mm and an upper portion width 1804 of approximately 20 mm. The pour spout height 1806 is approximately 25 mm and the pour spout depth 1808 is approximately 25mm with an overall pour spout radius 1810 of approximately 50 mm. Thus, the angled and curved cartridge exit 104 and the pour spout 500 reduce splashing and increase velocity, both factors in the present invention's effectiveness in reducing struvite.
[0079] The cartridge 100 and the housing 200 combinations are shown in FIG. 19A and FIG. 19B , where FIG. 19A shows the cartridge 100 inserted into the housing 200 having a horizontal exit tube 204 and FIG. 19B shows the same cartridge inserted into a housing 200 having a vertical exit tube 204 . In this case, the design of the pouring spout 500 is made to accommodate either arrangement. The pour spout 500 is made such that when placed in a cartridge 100 with a horizontal exit tube 204 , the portion of the poring spout 500 that forms the exit drip edge 322 remains closed so that it directs wastewater in a substantially horizontal direction into the housing exit tube 204 . On the other hand, when placed into a housing 200 having a vertical housing exit tube 204 as shown in FIG. 19B , the pouring spout 500 splits open and allows wastewater to enter the housing exit tube 204 in a substantially vertical direction. The same manufacturing methods previously discussed may be used to form this version of the pouring spout 500 and the pouring spout may be attached directly to the cartridge 100 or may be hinged from the cartridge 100 .
[0080] A blown-up cross section of a wiper 502 is shown in FIG. 20 . The wipers run from the top of the pouring spout 500 (or just above the bottom wall 112 of the cartridge 100 ) to just below the overflow level 318 . The wipers 502 cover the distance from the cartridge side wall 108 to the inside of the side of the housing body 200 (as can be seen in FIG. 14 ). The wipers 502 can be slightly oversized so that they can deform against the inside of the housing body 200 which helps to form a seal therebetween (though they can also be effective even if they don't touch the side wall of the housing 200 ). On a cartridge 100 such as model C1M2+ by Falcon Waterfree Technologies, LLC, this distance is approximately 4 mm. The wipers 502 with a depth of 5 mm can contact the side wall of the housing 200 . As shown, the wipers 502 are thicker at the base where they connect to the cartridge to provide more bonding surface area, and then taper to a thin wiping edge, similar to a windshield wiper. This allows them to easily deform when they meet the side of the housing. The respective dimensions are approximately 4 millimeters wide at the base where they connect to the cartridge and about 0.5 millimeters at the top where they touch the side wall of the housing. A portion of FIG. 20 on the right, shows an example of a locking mechanism.
[0081] A version of the present invention that includes a mechanical trap 2100 is shown in FIG. 21 . The body of the cartridge 100 is similar to that of a liquid trap cartridge. This cartridge 100 holds a mechanical trap 2100 , which has a collection area 2102 that centralizes the effluent as it enters the mechanical trap 2100 . The mechanical trap has a seal point 2104 that stays closed unless the weight of a liquid is upon it; at which point it is forced open, allowing the liquid to run through it. In this cartridge 100 , the exit back wall 2106 is angled away from the vertical axis and the cartridge exit 104 is U-shaped so that fluid will centralize on the exit back wall 2106 (the fluid back wall 2106 of a mechanical trap 2100 cartridge 100 is analogous to the outlet compartment vertical separator 316 of the liquid trap cartridges previously discussed). The pour spout 2108 is similar in shape and design to the pour spouts 100 previously discussed with respect to the liquid trap configurations. Thus, the pour spout 2108 directs outflowing fluids in a substantially horizontal direction as they pass down the exit back wall 2106 and through the pour spout 2108 and into the housing exit tube 204 . This virtually eliminates the splash normally experienced in the prior art configurations with mechanical traps, which dump effluent in the center of the housing and create significant struvite buildup. Note that a debris screen 2110 is shown. The debris screen 2110 prevents debris from entering and clogging the mechanical trap 2100 .
[0082] The pour spout 2108 of the mechanical trap cartridge 100 can be manufactured with all of the techniques and variations previously discussed with regard to fluid trap versions and can be similarly adapted for use with housing bodies 200 that have horizontal housing exit tubes 204 and vertical housing exit tubes 204 . Thus, the pour spout 2008 can be formed to sit below the level of the housing bottom 326 in the housing trough 324 (in some cases, in fluid communication with the housing trough 324 ) while being flexible to permit a twist-to-lock configuration
[0083] With the combination of a pour spout 500 that can flex, hanging below the cartridge 100 and into the housing trough 324 , a tapered shape to the cartridge exit 104 (when measured from top of the overflow level 318 to the pour spout 500 ), a generally U-shaped cartridge exit 104 , and a generally U-shaped area proximate the overflow level 318 , higher velocity with a narrowed, focused, aimed, stream can be created where previously liquid was allowed to simply flow substantially vertically and splash into the bottom of the housing and trough area. A similar exit configuration can be used for both fluid barrier and mechanical trap-type cartridges 100 . This is a meaningful advantage over the prior art, as the splash is a major cause of struvite precipitation and buildup. Further, the narrowed and focused fluid stream afforded by the present invention can also help to clear out any struvite buildup that has occurred, as it serves to “power wash” the area to where it is directed. As mechanical traps are often flushed with water, this cleaning action can be a very large advantage not only during regular use, but also during water flushes.
[0084] A further example of a cartridge 100 according to the present invention is shown in a side view in FIG. 22A and a top cross-sectional view in FIG. 22B . In this case, multiple wipers 502 are provided on the cartridge wall 108 . Here, the wipers 502 converge toward the exit drip edge 322 of the cartridge 100 to direct urine flow therethrough.
ELEMENTS LIST
[0085] The following list of elements is provided for ease of reference.
100 —Cartridge 102 —Cartridge Inlet 104 —Cartridge Exit 106 —Top Wall Flange 108 —Cartridge Side Wall 110 —Locking Tine 112 —Bottom Wall 200 —Housing Body 202 —Housing Flange 204 —Housing Exit Tube 300 —Fluid Barrier Layer 302 —Fluid Level 304 —Inlet Compartment 306 —Cartridge Ceiling 308 —Outlet Compartment 310 —Baffle 312 —Vertical Separator 314 —Sealant Layer 316 —Outlet Compartment Vertical Separator 316 A—Outlet Compartment Vertical Separator (back of wall first side) 316 B—Outlet Compartment Vertical Separator (front of wall, second side) 318 —Overflow Level 320 —Discharge Section 322 —Exit Drip Edge 324 —Housing Trough 326 —Housing Bottom 330 —O-Ring 500 —Pour Spout 502 —Wiper 800 —Vent 802 —Throat 804 —Overflow Gap 1000 —Locking Tine Keyway 1800 —Hinge Area 2100 —Mechanical Trap 2102 —Tapered Collection Area 2104 —Seal Point 2106 —Exit Back Wall 2110 —Debris Screen 2108 —Drip Edge | A fluid exit portion for a splash-reducing urinal cartridge is presented. The exit portion comprises a splash reducer for causing fluid to exit the cartridge in a splash-reduced manner. The splash reducer is generally in the form of a spout with a tapered exit area for accelerating and directing the fluid. The spout may comprise converting fins to urge fluid to collect in a progressively narrower channel. When the cartridge is installed into a housing, the splash reducer ensures that fluid exiting the cartridge transitions into the housing with minimal disturbance, substantially parallel to the housing. The splash reducer is formed of a flexible material or is hinged with respect to the cartridge body to allow for easy insertion into a housing. | 4 |
This application is a division of co-pending application Ser. No. 08/775,284, filed Dec. 31, 1996. This application claims benefit of provisional application Ser. No. 60/019,251 filed Jun. 7, 1996.
BACKGROUND OF THE INVENTION
The present invention relates to an improved wet mop. More specifically, the present invention is directed to a cordless wet mop including a scrubbing assembly and a vacuum assembly for collecting dirty water from the floor to achieve a clean and substantially dry floor surface.
Mops for cleaning floor surfaces generally include an absorbent mop or sponge head and some type of wringing mechanism for wringing dirty water out of the mop or sponge head. In particular, the mop is used in conjunction with a bucket of cleaning liquid, usually consisting of water with a cleaning additive. The mop absorbs the cleaning liquid which is used to scrub the floor. Once the mop has been contaminated by scrubbing the floor, it is inserted back into the bucket to rinse the mop and to absorb additional cleaning liquid. The continuous introduction of the dirty mop into the clean liquid in the bucket quickly contaminates the clean liquid in the bucket and reduces the cleaning ability during a remainder of the mopping operation. Thus, it would be desirable to prevent contamination of the cleaning liquid during a floor cleaning operation. In addition, it would be desirable to eliminate the approximately 15 minutes of floor drying time necessary with conventional mop and bucket cleaning.
Suction squeegees have been proposed which remove cleaning liquid from a floor surface which has previously been cleaned. One such suction squeegee device is disclosed in U.S. Pat. No. 5,067,199. However, this suction squeegee device does not eliminate the problem of contamination of the clean water bucket because a conventional mop and bucket must be used to clean the floor prior to use of the suction squeegee device. In addition, this suction squeegee has the disadvantage of requiring three or four separate devices to perform the cleaning operation including the suction squeegee, a mop, a mechanism to wring dirty water out of the mop, and a bucket.
Another suction cleaning apparatus has been described which provides a combined scrubbing and water pick-up apparatus for cleaning and drying a floor surface. This device includes a combined clean water and dirty water tank with a flexible membrane separating the clean and dirty water in the tank. Clean water is dispensed from the tank and a cleaning nozzle including bristles or brushes used for scrubbing. After scrubbing, a suction system is activated to remove the dirty water from the floor and the dirty water is collected in the tank.
Examples of combination scrubbing and water pick-up devices are disclosed in U.S. Pat. Nos. 2,986,764; 3,020,576; 3,040,362; 3,040,363; and 3,060,484. The devices described in these patents have several drawbacks including the cumbersome size and weight of the device, the need for a power supply cord which gets in the users way, and the safety concerns associated with the use of household voltage in combination with a water filled device.
SUMMARY OF THE INVENTION
The device according to the present invention addresses the disadvantages of the prior art by providing an entirely self contained cordless wet mop which combines scrubbing and drying in one device and leaves the floor in a substantially dry state.
According to an additional aspect of the present invention, a suction cleaning device for cleaning surfaces includes a cleaning device housing, a handle connected to the housing, an absorbent cleaning member mounted on the housing and movable between an extended position in which the cleaning member extends from the housing and is used to clean a surface and a retracted position in which the cleaning member is substantially retracted into the housing, a suction motor within the housing for removing a contaminated liquid from the surface, a tank mounted on the housing for collecting the contaminated liquid which has been removed from the surface by operation of the suction motor, and a battery power source providing power to the suction motor.
According to a further aspect of the present invention, a suction cleaning device for cleaning surfaces includes a cleaning device housing, a retractable sponge mounted on the housing and movable between an extended position and a retracted position, a retracting mechanism for moving the sponge between the extended and retracted positions, a suction system for removing and collecting contaminated liquid from a surface to be cleaned, and a switch for activating the suction system in response to the retraction mechanism, wherein the suction system is turned on when the sponge is in the retracted position, and the suction system is turned off when the sponge is in the extended position.
According to an additional aspect of the invention, a self contained mopping and drying system for floors includes a housing, a handle connected to the housing, an absorbent cleaning member mounted on the housing, a pair of squeegees mounted on the housing for collecting contaminated liquid on a floor surface, a suction system within the housing for removing the contaminated liquid from the floor surface which has been collected by the pair of squeegees, wherein the suction system leaves the floor in a substantially dry state, a tank mounted on the housing for collecting the contaminated liquid which has been removed from the surface by operation of the suction motor, and a battery power source received in the housing and providing power to the suction system.
According to a further aspect of the invention, a cleaning device includes a cleaning device housing, a handle connected to the housing, a sponge mounted on the housing and movable between an extended position in which the sponge extends from the housing and is used to clean a surface and a retracted position in which the sponge is substantially retracted into the housing, the sponge having a central plane bisecting the sponge, a pair of squeegees mounted on the housing in a parallel spaced arrangement, the pair of squeegees positioned in first and second planes, and wherein the central plane of the sponge diverges from the first and second planes of the squeegees in a direction away from the housing.
One advantage of the cleaning device is that a single self-contained device performs liquid dispensing, scrubbing, and drying.
Another advantage of the cleaning device is that the contamination of a cleaning liquid is prevented by providing separate clean water and dirty water tanks.
An additional advantage of the cleaning device is the compact size and light weight of the device.
Still other advantages and benefits of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangements of parts, preferred embodiments and methods of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof, and wherein:
FIG. 1 is a longitudinal cross section taken through the center of a first embodiment of the present invention with the sponge shown in an extended position, and the battery pack latch shown in an unlocked position;
FIG. 2 is a longitudinal cross section as illustrated in FIG. 1 with the sponge shown in a retracted position and the battery pack latch shown in a locked position;
FIG. 3 is a side view of the embodiment of FIG. 1 with a side of the housing removed and the sponge in the retracted position;
FIG. 3A is an enlarged cross section along line A--A of FIG. 3;
FIG. 4 is an enlarged cross section of the forward end of the embodiment of FIG. 1;
FIG. 5 is an enlarged cross section of the central section of the embodiment of FIG. 1;
FIGS. 6A and 6B are opposite side views of a second embodiment of the invention;
FIGS. 7A, 7B, and 7C are right, top, and left side views, respectively, of a third embodiment of the invention;
FIGS. 8A and 8B are side views of a fourth embodiment of the invention with the sponge in an extended and a retracted position;
FIG. 9 is a perspective view of a fifth embodiment of the invention; and
FIG. 10 is a perspective view of a sixth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein the showings are for the purposes of illustrating the preferred embodiments of the invention only and not for purposes of limiting same, a cordless wet mop and vacuum device according to a first embodiment of the present invention is illustrated in FIGS. 1-5. The device generally includes a handle assembly 10 connected to a housing 12, a removable clean water bottle 14, and a removable dirty water tank 16. A cleaning assembly is mounted in the housing 12 and includes a retractable sponge 18, a pair of squeegees 20, a battery pack 22, a suction motor 24, a suction fan 26, and a switch 30 for turning the suction motor on and off. The clean water bottle 14 includes a plunger 28 for dispensing clean water combined with a cleaning solution onto the floor. The sponge 18 is extended from the housing 12 when it is used to scrub the floor and is then retracted into the housing during the suction operation. The retraction of the sponge 18 activates the suction motor 24 and causes the suction system to begin to draw the water from the floor into the dirty water tank 16. The squeegees 20, shown in FIGS. 3 and 4, are drawn over the floor while the suction is activated to collect the dirty water and leave the floor in a substantially dry state.
The handle assembly 10 includes an upper handle 40 with a foam hand grip 42 and a cap 44. The cap 44 is preferably provided with a swivel which may be used to hang the device on the wall. The upper handle 40 includes a threaded insert 46 which allows the upper handle to be threaded onto a lower handle 48 which is a one piece handle fixed in the housing 12 by at least two bolts 50. The one piece handle 48 is preferably molded of plastic and includes the threaded section for mating with the treaded insert 46, a support for a wringer handle 52, and means to mount the lower handle 48 on the housing 12.
The wringer handle 52 is pivotally mounted on the lower handle 48 at a first pivot 54 and is pivotally attached to a rod 56 at a second pivot 58. The wringer handle 52 is constructed with two legs 60 one of which extends around each side of the lower handle 48. A flat end of the rod 56 is inserted between the two legs 60 and is pivotally attached to the legs by a pin extending through the rod and the legs. The rod 56 extends alongside the lower handle 48 and through the housing 12. An opposite end of the rod 56 passes through a metal bracket 64 and attaches to the sponge 18.
Operation of the wringer handle 52 extends and retracts the sponge 18 and simultaneously turns on and off the suction motor 24 via the switch 30. The wringer handle 52 moves the sponge 18 between three positions. In the extended position illustrated in FIG. 1, the sponge 18 extends in fan like shape beyond a pair of sponge rollers 62 which are mounted on a wringer bracket 74. In the extended position, the metal bracket 64 abuts the rollers 62 and holds the sponge in the desired cleaning position. To retract the sponge 18, the wringer handle 52 is moved away from the upper handle 40 in the direction of the arrow A. As the wringer handle is moved, the rod 56 causes the sponge to be pulled upward. As the sponge 18 is retracted, the water which has been absorbed in the sponge is wrung out onto the floor by squeezing the sponge between the rollers 62.
The retracted position of the sponge 18 is illustrated in FIG. 2. In this position, the sponge 18 is received in the metal bracket 64 and a forward end of the sponge extends only a small distance past the ends of rollers 62. This distance is preferably between 0.1 inches and 0.5 inches. The sponge 18 is held in the retracted position by the expansion of a portion of the sponge behind the rollers 62. In addition, detents (not shown) may be provided in the wringer handle 52 to maintain the sponge in the retracted position.
The wringer handle 52 also is used to eject the sponge 18 for replacement or cleaning. The ejection of the sponge 18 is performed by moving the wringer handle 52 toward the upper handle 40 in the direction of the arrow B. This forces the sponge 18 and the metal bracket 64 through the rollers 62 which flex apart in the wringer bracket 74.
The wringer handle 52 also turns on and off the suction motor 24 by operating the switch 30 with a protruding bend 66 in the rod 56. Thus, the suction motor 24 is operated only when the sponge 18 is retracted. This allows the conservation of battery power by preventing motor operation when it is not necessary, allowing the battery power of the battery pack 22 to be conserved. As seen in FIG. 2, when the sponge is retracted, the protruding bend 66 in the rod 56 passes over the switch 30 turning the suction motor 24 on.
Generally, a 6 volt battery pack 22 having 5 cells will provide between 5 and 10 minutes of operating time for a 12-14 amp permanent magnet motor. Since the suction motor 24 is operated only when suction is required, the battery pack 22 will be able to be used for a floor of at least 250 square feet without requiring recharging.
The battery pack 22 is illustrated more clearly in FIG. 5 which is an enlargement of a central portion of FIG. 1. The battery pack 22 is preferably a 6 volt rechargeable battery pack capable of holding up to six cells which is received in a battery cavity 68 within the housing 12. The battery pack is held in place in the cavity by a locking member 70 which is rotatable about the lower handle 48. Two protrusions 72 on the lower handle maintain the locking member 70 at the proper axial location on the handle. The locking member 70 is illustrated in unlocked and locked positions in FIGS. 1 and 2, respectively.
As the battery pack 22 slides into the battery cavity 68, two spring loaded battery contacts 80 are moved out of the way and into a position in which the battery contacts 80 in the battery cavity contact mating battery contacts 78 on the side surface of the battery pack.
The suction motor 24 is mounted within a motor mount assembly 82 in a conventional manner, such as mounting the motor in a pair of saddles molded into the interior of the housing 12. The suction motor 24 is preferably a permanent magnet dc motor, such as a 12-14 amp, 6 volt strontium magnet motor providing an output of about 18,000 to 25,000 rpm, preferably 21,000 to 22,000 rpm. The suction motor 24 is isolated from an adjacent fan chamber 84 by a resilient grommet 86, shown in FIG. 5, which prevents any water which may enter the fan chamber from passing into the motor.
The suction motor 24 used in the present invention is self cooling and does not require a fan for cooling. However, a motor fan may be added if needed. Vents 88 are preferably provided in a side of the housing 12 for allowing air circulation to the motor. The fan chamber 84 also includes exhaust vents 90 through which the exhaust gas passes.
The lower portion of the housing is best illustrated in the enlarged view of FIG. 4 and includes the sponge, a squeegee tray 92, the dirty water tank 16, the fan chamber 84, and the suction fan 26.
The squeegee tray 92 includes two elongated squeegees 20 which snap into the squeegee tray 92 in a known manner. The squeegees are between 5 and 20 inches long, preferably between 8 and 12 inches long. The squeegee tray 92 has a suction inlet 94 which is an elongated oval-shaped opening located between the two squeegees 20 and extending along about 1/4 to 1/2 of the total length of the squeegees at the center of the squeegees. The water is drawn up along the length of the squeegees 20 from the open ends between the squeegees into the suction inlet 94. The cross-sectional area of a passageway between the two squeegees and the floor, and the cross-sectional area of the suction inlet 94 are both dimensioned to provide a desired velocity of air which will entrain the water droplets in the air. Operating at velocities of between about 1,000 ft/min and about 3,000 ft/min or higher will maintain the water droplets entrained in the air.
A set of wheels 122 are mounted on the squeegee tray 92 to allow the entire device to be easily wheeled across the floor during scrubbing, squeegeeing, or transporting. The squeegees 20 are mounted in the squeegee tray 92 in a parallel configuration such that when the device is wheeled across the floor, both squeegees are in contact with the floor. When the sponge 18 is in an extended position, the squeegees 20 will no longer contact the floor because the sponge extends beyond the squeegees. A central plane X which bisects the sponge 18 is positioned at an angle α with respect to the planes Y of the squeegees. This angle α is approximately between 10 and 30 degrees, preferably about 25 degrees.
The top surface of the squeegee tray 92 includes an oval-shaped groove 96 surrounding the suction inlet 94. A resilient sealing member 98 is placed in the groove 96 to provide a seal between the suction inlet 94 and a central tube 100 of the dirty water tank 16. The resilient sealing member 98 is preferably a compressible sponge rubber material which biases the tank 16 upward so that it is in a proper position once it has been inserted into the housing 12.
The squeegees 20 are each formed with a smooth edge on one side and a serrated edge on an opposite side. The squeegees are positioned within the squeegee tray 92 with the smooth sides of the two squeegees facing each other. Thus, as the device is moved across the floor, both of the squeegees will contact the floor and flex. The water will first pass under the first squeegee due to the fact that the serrated edge of the squeegee is in contact with the floor. This water will then be trapped by the second squeegee having the smooth edge in contact with the floor. In this way the device may be used alternately in both a forward and a reverse direction as the user works across the floor surface. The water is collected from between the squeegees by a flow of air from the open ends between the squeegees to the central suction inlet 94.
From the central suction inlet 94, the water passes into the dirty water tank 16 including the central tube 100 which is molded into the tank. The central tube 100 extends far enough up into the tank 16 to avoid the need for a closing member to close the central tube against leaks when the tank is removed for emptying. A cover 102 is placed inside the top of the tank 16 and is sealed about the edges to the tank by an O-ring 104. The cover 102 includes an opening 106 through which air passes from the tank 16 to the fan chamber 84. The cover 102 also includes a baffle 108 for deflecting the water which is drawn through the central tube 100 into the tank. A face seal 116 is provided around the opening 106 in the cover 102 to seal the passage between the dirty water tank 16 and the fan chamber 84.
The central tube 100 and the baffle 108 are positioned within the dirty water tank 16 such that a majority of the tank capacity is available in an inclined operating position. In addition, if the device is laid down with a back surface 118 of the device on the floor when the dirty water tank is 16 partially filled, the dirty water will not come out through either the central tube 100 or the opening 106 to the fan chamber 84.
The dirty water tank 16 and cover 102 assembly are removable from the housing 12 for emptying and cleaning. The tank 16 is inserted by placing the bottom of the tank against the sealing member 98 and rocking the tank forward into the housing. Once inserted, the tank 16 is held in place by a latch 110 which is slidably mounted on the exterior of the tank and has a protrusion 112 which is received in a corresponding recess 114 in the housing 12. The cover 102 of the dirty water tank 16 may also include one or more detents 120 which retain the tank in the housing while the latch 110 is being operated.
The suction system operates by drawing air from the open ends between the two squeegees 20 through the suction inlet 94 and the central tube 100 of the dirty water tank 16 at a velocity which entrains the water droplets in the air. The water hits the baffle 108 within the tank 16 and is deflected down into the tank. The velocity of the air slows as it enters the tank 16 from the central tube 100 and the entrained water droplets fall out into the tank. The air then passes around both sides of the central tube 100, out of the tank through the opening 106, into the fan chamber 84, through the suction fan 26, and out of the housing via the vents 90. In order to maintain the velocity drop in the tank 16 which causes the water to fall out of the air in the tank, the cross-sectional area of the air passage through the tank between the baffle 108 and the opening 106 must be larger than the cross-sectional area of the central tube 100. As long as the velocity of the air in the tank is decreased to less than about 1000 ft/min, the water will remain in the tank.
The dirty water tank 16 may also include a control device which turns off the suction when the water in the tank 16 has reached a certain level. This device may include a float device which blocks off the tank opening 106 when the tank 16 is full. Alternately, the motor which is used may provide an automatic shut off. For example, a motor having 9 inches of sealed suction will provide an automatic shut off when the tank is filled to 9 inches.
A cleaning solution is dispensed onto the floor surface prior to scrubbing by the clean water bottle 14 which is removably mounted on a front surface 124 of the housing. The cleaning solution or cleaning liquid which is used in the clean water bottle according to the present invention may be any known cleaning solution or combination of solutions, such as water with a detergent additive.
The bottle 14 is preferably a blow molded bottle having three openings and a plunger 28 which is activated to allow the cleaning solution to be released onto the floor. A first opening 134 is provided on a side surface of the bottle and has a threaded cap 140 which is removed for filling the bottle. Because the first opening 134 is located on a side of the bottle, the bottle can easily be filled in a sink. The cap 140 may be used as a measuring device to measure the desired amount of a cleaning additive which is mixed with water in the bottle.
The second opening 136 is provided with a threaded dispensing cap 142 having a dispensing opening 148 and a plunger seat or seal 144 surrounding the dispensing opening against which an end of the plunger is sealed. The third opening 138 receives the plunger 28 and provides a vent. The three-opening bottle 14 allows the bottle to be filled without removing the plunger 28 from the bottle.
The plunger 28 has a handle 146, illustrated in FIG. 1, at a first end 14 and a second end extends through the third opening 138 in the bottle 14 to engage the plunger seat 144 and close the dispensing opening 148. A spring 150, best illustrated in FIG. 5, acts between an annular ring 152 on the plunger 132 and a bottom surface 154 of a plunger receiving cap 156 to bias the plunger in a closed position.
The plunger cap 156 includes a cylindrical portion 158 which extends into the neck of the opening 138 in the bottle 14 and provides a venting mechanism for venting air from the bottle when the plunger handle 146 is pulled in the direction of the arrow C. The interior of the cylindrical portion 158 of the plunger cap has a groove 162 which provides the venting mechanism. A first O-ring 160 located in an annular seat 166 on the plunger provides a seal between the plunger 28 and the plunger cap 156 in the closed position. However, when the plunger handle 146 is moved upward in the direction of the arrow C opening the dispensing opening 148, the first O-ring 160 slides up above the groove 162 and allows air to pass through the cap into the bottle. A second O-ring 164 provides a seal between the plunger cap 156 and the bottle 14.
The bottle 14 is mounted on the housing 12 by a pair of fingers 170 of the housing which extend upward and are received in mating grooves 172 in the bottle by sliding the bottle downward onto the fingers, as shown in FIG. 3A. The bottle 14 is then locked in place by a pivoting latch 174 which snaps over a ridge 176 on the top of the bottle.
The clean water bottle 14 is designed to contain enough cleaning liquid to clean a floor of at least 250 square feet, preferably 250 to 300 square feet in area. In addition, the clean water bottle 14 preferably has a volume which is somewhat smaller than a volume of the dirty water tank 16. This allows the dirty water tank 16 to collect both a spilled liquid and the entire contents of the clean water bottle 14. For example, the clean water bottle 14 may have a capacity of about 16 oz, while the dirty water tank has a capacity of about 24 oz. Preferably, the volume of the tank 16 is about 20 to 60 percent greater than the volume of the bottle 14.
Although the clean water bottle 14 and the dirty water tank 16 have been referred to as a bottle and a tank, respectively, it should be understood that the terms bottle and tank refer generally to any type of container for liquid. These containers are preferably formed of a light weight, durable, and somewhat flexible material, such as plastic.
The first embodiment of the present invention includes a retractable sponge and a fixed pair of squeegees. However, it should be understood that a fixed sponge and movable squeegees may also be used.
FIGS. 6A and 6B illustrate an alternative embodiment of a cleaning device 200 in which a sponge 202 and squeegees 204 are provided in a fixed position on the bottom of the cleaning device. This embodiment is used to clean the floor in the position shown in FIG. 6A where the sponge 202 is in contact with the floor. Cleaning liquid may be dispensed onto the floor by pumping the handle 206 up and down before or during cleaning. When cleaning is complete, the device 200 is flipped over to the position illustrated in FIG. 6B so that the squeegees 204 are in contact with the floor and the floor may be dried in the manner described with respect to the first embodiment.
The embodiment of FIGS. 7A-7C is a cleaning device 300 also having a fixed sponge 302 and fixed squeegees 304 which is flipped between the orientations of FIGS. 7A and 7C for washing and drying operations. This embodiment also includes an additional scouring pad 306 which is positioned on one end of the device 300 and is used for scouring in the position illustrated in FIG. 7B. The scouring pad 306 may be removably attached, for example by Velcro. The cleaning device 300 also includes a telescoping handle 308.
A fourth embodiment of a cleaning device 400 is illustrated in FIGS. 8A and 8B. The cleaning device 400 includes a retractable sponge 402 and fixed squeegees 404. A cleaning liquid dispensing orifice 406 is located on a top of the device 400 and the pump handle 408 is used to pressurize the cleaning liquid so that it may be sprayed out of the dispensing orifice.
In the embodiment of the cleaning device 500 illustrated in FIG. 9, the clean water bottle 502 and the dirty water tank 504 are mounted side by side on the device. In addition, the sponge 506 is formed so that it surrounds the squeegees 508.
Finally, the cleaning device 600 of FIG. 10 has a removable dispensing bottle 602 received in a recess 604 in the body of the cleaning device. This dispensing bottle 602 has a spray nozzle 606 for spraying cleaning liquid onto the floor.
Advantages of each of the embodiments of the present invention include the fact that the device is a self-contained unit which includes clean water and there is no need to carry around heavy bucket of water. In addition, the problem of contamination of clean water is eliminated and the floor is left virtually dry. The device is also easily cleaned because once the dirty water tank is removed, any obstruction in the suction system can be easily seen and removed.
While the invention has been described in detail with reference to preferred embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed without departing from the spirit and scope of the invention. | The present invention relates to a suction cleaning device which provides liquid dispensing, scrubbing, squeegeeing, and suction drying in a single, compact, self contained device. The suction cleaning device includes a cleaning device housing, a handle connected to the housing, an absorbent cleaning member mounted on the housing and movable between an extended and a retracted position, and a pair of squeegee blades. The device includes a suction system which draws the water from the floor surface which has been cleaned into a tank mounted on the housing which collects the liquid from the floor surface. A clean water bottle is provided on the housing for delivering cleaning liquid to the floor and a rechargeable battery power source provides power to the suction motor. The cleaning device is compact and lightweight and leaves the floor in a substantially dry state. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a display device and driving module thereof, and more particularly, to a display device reducing power consumption and increasing brightness via changing pixel arrangement method and driving module thereof.
[0003] 2. Description of the Prior Art
[0004] A liquid crystal display (LCD) is a flat panel display which has the advantages of low radiation, light weight and low power consumption and is widely used in various information technology (IT) products, such as notebook computers, personal digital assistants (PDA), and mobile phones. An active matrix thin film transistor (TFT) LCD is the most commonly used transistor type in LCD families, and particularly in the large-size LCD family. A driving system installed in the LCD includes a timing controller, source drivers and gate drivers. The source and gate drivers respectively control data lines and scan lines, which intersect to form a cell matrix. Each intersection is a cell including crystal display molecules and a TFT. In the driving system, the gate drivers are responsible for transmitting scan signals to gates of the TFTs to turn on the TFTs on the panel. The source drivers are responsible for converting digital image data, sent by the timing controller, into analog voltage signals and outputting the voltage signals to sources of the TFTs. When a TFT receives the voltage signals, a corresponding liquid crystal molecule has a terminal whose voltage changes to equalize the drain voltage of the TFT, which thereby changes its own twist angle. The rate that light penetrates the liquid crystal molecule is changed accordingly, allowing different colors to be displayed on the panel.
[0005] An image quality of the LCD can be determined via counting a number of pixels of the LCD located in a direction. For example, the user may acquire a reference of determining the image quality of the LCD via calculating the pixels per inch (PPI). Please refer to FIG. 1 , which is a schematic diagram of the relationship between the image quality and the PPI. As shown in FIG. 1 , the image quality is proportional to the PPI. However, recognizing ability of the eyes has a limit. When the PPI of the LCD exceeds a threshold, the eyes generally cannot recognize each pixel of the LCD. In other words, the image viewed by the eyes would become no-grid if the PPI of the LCD exceeds the threshold.
[0006] For example, under a condition that the visual acuity of the eyes is 1.0 and a distance between the eyes and the LCD is 12 inches, the eyes is difficult to recognize distances between the pixels of the LCD when the PPI of the LCD exceeds 286. In other words, the image received by the eyes becomes no-grid if the PPI of the LCD reaches 286. In such a condition, the number of sub-pixels corresponding to each pixel can be accordingly decreased, to increase the aperture ratio and to reduce the power consumption of the LCD. Thus, how to decrease the number of sub-pixel while maintaining the image quality becomes a topic to be discussed.
SUMMARY OF THE INVENTION
[0007] In order to solve the above problem, the present invention provides a reducing power consumption and increasing brightness via changing pixel arrangement method and driving module thereof.
[0008] In an embodiment, the present invention discloses a display device. The display device comprises a plurality sub-pixel groups, wherein each of the plurality sub-pixel groups comprises: a first sub-pixel, locating at a first column, a first row and a second row adjacent to the first row; a second sub-pixel, locating at a second column adjacent to the first column, the first row and the second row; a third sub-pixel locating at a third column adjacent to the second column and a first row; and a fourth sub-pixel locating at the third column and the second row.
[0009] In another embodiment, the present invention discloses a driving module. The driving module is utilized in a display device comprising a plurality of sub-pixel groups, wherein each of the plurality of sub-pixel groups comprises a first sub-pixel, locating at a first column, a first row and a second row adjacent to the first row; a second sub-pixel, locating at a second column adjacent to the first column and the first row and the second row; a third sub-pixel locating at a third column adjacent to the second column and a first row; and a fourth sub-pixel locating at the third column and the second row.
[0010] In still another embodiment, the present invention discloses a display device. The display device comprises a plurality sub-pixel groups, wherein each of the plurality sub-pixel groups comprises a first sub-pixel, locating at a first column, a first row and a second row adjacent to the first row; a second sub-pixel, locating at a second column adjacent to the first column, a third column adjacent to the third column, and the first row; a third sub-pixel, locating at the second column, the third column and the second row; a fourth sub-pixel, locating at a fourth column adjacent to the third column, the first row and the second row; a fifth sub-pixel, locating at a fifth column adjacent to the fourth column, the first row and the second row; a six sub-pixel, locating at a sixth column adjacent to the fifth column, the first row and the second row; and a seventh sub-pixel, locating at a seventh column adjacent to the sixth column, the first row and the second row.
[0011] In another embodiment, the present invention discloses a driving module. The driving module is utilized in a display device comprising a plurality sub-pixel groups, wherein each of the plurality sub-pixel groups comprises a first sub-pixel, locating at a first column, a first row and a second row adjacent to the first row; a second sub-pixel, locating at a second column adjacent to the first column, a third column adjacent to the third column, and the first row; a third sub-pixel, locating at the second column, the third column and the second row; a fourth sub-pixel, locating at a fourth column adjacent to the third column, the first row and the second row; a fifth sub-pixel, locating at a fifth column adjacent to the fourth column, the first row and the second row; a six sub-pixel, locating at a sixth column adjacent to the fifth column, the first row and the second row; and a seventh sub-pixel, locating at a seventh column adjacent to the sixth column, the first row and the second row.
[0012] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic diagram of the relationship between the image quality and the pixel per inch.
[0014] FIG. 2 is a schematic diagram of a display device according to an embodiment of the present invention.
[0015] FIG. 3 is a schematic diagram of the sub-pixel group shown in FIG. 2 .
[0016] FIG. 4 is a schematic diagram of a display device according to an embodiment of the present invention.
[0017] FIG. 5 is a schematic diagram of the sub-pixel group shown in FIG. 4 .
[0018] FIG. 6 is a schematic diagram of a display device according to an embodiment of the present invention.
[0019] FIG. 7 is a schematic diagram of the sub-pixel group shown in FIG. 6 .
[0020] FIG. 8 is a schematic diagram of a display device according to an embodiment of the present invention.
[0021] FIG. 9 is a schematic diagram of a display device according to an embodiment of the present invention.
[0022] FIG. 10 is a schematic diagram of a display device according to an embodiment of the present invention.
[0023] FIG. 11 is a schematic diagram of a display device according to an embodiment of the present invention.
[0024] FIG. 12 is a schematic diagram of the sub-pixel group shown in FIG. 11 .
[0025] FIG. 13 is a schematic diagram of circuit layout of the display device shown in FIG. 9 .
[0026] FIG. 14 is a schematic diagram of circuit layout of the display device shown in FIG. 11 .
[0027] FIG. 15 is a schematic diagram of a display device according to an embodiment of the present invention.
[0028] FIG. 16 is a schematic diagram of the sub-pixel group shown in FIG. 15 .
[0029] FIG. 17 is a schematic diagram of another color arrangement method of the sub-pixel group shown in FIG. 16 .
[0030] FIG. 18 is a schematic diagram of a display device according to an embodiment of the present invention.
[0031] FIG. 19 is a schematic diagram of a display device according to an embodiment of the present invention.
[0032] FIG. 20 is a schematic diagram of circuit layout of the display device shown in FIG. 19 .
[0033] FIG. 21 is a schematic diagram of another implementation of the display device shown in FIG. 8 .
[0034] FIGS. 22A-22C are schematic diagrams of other implementations of the display device shown in FIG. 19 .
DETAILED DESCRIPTION
[0035] The present invention reduces a number of sub-pixels corresponding to each pixel via different arrangements of the sub-pixels. An aperture ratio and brightness of the liquid crystal display (LCD) are accordingly improved, the power consumption and the layout area of the LCD are further decreased.
[0036] Please refer to FIG. 2 , which is a schematic diagram of a display device 20 according to an embodiment of the present invention. The display device 20 may be an electronic device with a liquid crystal panel, such as a television, a smart phone or a tablet. FIG. 2 only shows parts of sub-pixels of the display device 20 for illustrations. Note that, FIG. 2 is utilized for illustrating the relative positions of the sub-pixels and not for limiting the ratio between length and width. As shown in FIG. 2 , the display device 20 comprises a plurality of repeating sub-pixel groups SPG 1 (only one sub-pixel group SPG 1 is marked in FIG. 2 for illustrations). In order to simplify the descriptions, please refer to FIG. 3 which is a schematic diagram of the sub-pixel group SPG 1 shown in FIG. 2 . In FIG. 3 , the sub-pixel group SPG 1 comprises sub-pixels SP 1 -SP 4 . The sub-pixel SP 1 is located at the j column, the i row and the i+1 row and the sub-pixel SP 2 is located at the j+1 column, the i row and the i+1 row. On the other hand, the sub-pixels SP 3 and SP 4 are transversely located at the j+2 column and the j+3 column (the j+2 column and the j+3 column may be regarded as a single column) and are respectively located at the i row and the i+1 row. Via the abovementioned arrangement of the sub-pixels SP 1 -SP 4 , the sub-pixel group SPG 1 is corresponding to 2 pixels. That is, a number of the sub-pixels corresponding to a pixel is reduced, to increase the aperture ratio of display device 20 and to decrease the power consumption of the display device 20 .
[0037] In detail, the sub-pixels SP 1 and SP 2 may have a same height L 1 and the height L 1 is greater than a height L 2 of the sub-pixel SP 4 and a height L 3 of the sub-pixel SP 4 . Since the sub-pixels SP 3 and SP 4 can be regarded as transversely located sub-pixels SP 1 and SP 2 , a length L 4 of the sub-pixels SP 3 and SP 4 is also greater than the heights L 2 and L 3 . Further, the sub-pixels SP 1 -SP 4 correspond to blue, white, red and green, respectively. Via adding the sub-pixel SP 2 corresponding to white, the brightness of the display device 20 increases and the power consumption of the display device 20 decreases. Moreover, the sub-pixel group SPG 1 is corresponding to 2 pixels and each pixel is corresponding to 2 sub-pixels according to the arrangement shown in FIG. 3 . In this embodiment, the sub-pixels SP 1 and SP 2 form a pixel and the sub-pixels SP 3 and SP 4 form another pixel. If the resolution of the display device 20 is constant, the number of the sub-pixels utilized for realizing the display device 20 would be reduced and the aperture ratio of the display device 20 would be accordingly increased.
[0038] In another embodiment, the sub-pixel SP 2 may be corresponding to other colors, such as yellow. Further, the sub-pixel SP 2 may be corresponding to one of the colors corresponding to the sub-pixels SP 1 , SP 3 and SP 4 . That is, the sub-pixels SP 1 -SP 4 are corresponding to at least three colors. Note that, the sequence of the colors corresponding to the sub-pixels SP 1 -SP 4 may be modified according to different applications and design concepts and are not limited to the color sequence shown in FIG. 3 . For example, the sub-pixels SP 1 -SP 4 may be changed to be corresponding to red, white, green and blue, and are not limited herein.
[0039] As to the polarity arrangement of the sub-pixels SP 1 -SP 4 of the sub-pixel group SPG 1 please refer to the following descriptions. Since the sub-pixels SP 1 and SP 2 are corresponding to the same pixel, the polarity of the sub-pixel SP 1 is opposite to that of the sub-pixel SP 2 . For example, the polarity of the sub-pixel SP 2 is negative when the polarity of the sub-pixel SP 1 is positive; and the polarity of the sub-pixel SP 2 is positive when the polarity of the sub-pixel SP 1 is negative. Similarly, since the sub-pixels SP 3 and SP 4 are corresponding to the same pixel, the polarity of the sub-pixel SP 3 is opposite to that of the sub-pixel SP 4 .
[0040] In an embodiment, a vertical displacement may exist between the sub-pixels of the display device 20 shown in FIG. 2 . Please refer to FIG. 4 , which is a schematic diagram of a display device 40 according to an embodiment of the present invention. The display device 40 may be an electronic device with a liquid crystal panel, such as a television, a smart phone or a tablet. FIG. 4 only shows parts of sub-pixels of the display device 40 for illustrations. Note that, FIG. 4 is utilized for illustrating the relative positions of the sub-pixels and not for limiting the ratio between length and width. As shown in FIG. 4 , the display device 40 comprises a plurality of repeating sub-pixel groups SPG 2 (only one sub-pixel group SPG 2 is marked in FIG. 4 for illustrations). In order to simplify the descriptions, please refer to FIG. 5 which is a schematic diagram of the sub-pixel group SPG 2 shown in FIG. 4 . In FIG. 5 , the sub-pixel group SPG 2 comprises sub-pixels SP 5 -SP 8 . The sub-pixel SP 5 is located at the j column, the i row and the i+1 row and the sub-pixel SP 6 is located at the j+1 column, the i row and the i+1 row. On the other hand, the sub-pixels SP 7 and SP 8 are transversely located at the j+2 column and the j+3 column. Different from the sub-pixel group SPG 1 shown in FIG. 3 , the transverse sub-pixels SP 7 and SP 8 are shifted upward and are located at the i−1 row and the i row, respectively. Via the abovementioned arrangement of the sub-pixels SP 5 -SP 8 , the sub-pixel group SPG 2 is corresponding to two pixels and the aperture ratio of the display device 40 is accordingly increased. The colors and the length-width relationships between the sub-pixels SP 5 -SP 8 of the sub-pixel group SPG 2 can be referred to the sub-pixels SP 1 -SP 4 of the sub-pixel group SPG 1 , and are not narrated herein for brevity.
[0041] Please refer to FIG. 6 , which is a schematic diagram of a display device 60 according to an embodiment of the present invention. The display device 60 may be an electronic device with a liquid crystal panel, such as a television, a smart phone or a tablet. FIG. 6 only shows parts of sub-pixels of the display device 60 for illustrations. Note that, FIG. 6 is utilized for illustrating the relative positions of the sub-pixels and not for limiting the ratio between length and width. As shown in FIG. 6 , the display device 60 comprises a plurality of repeating sub-pixel groups SPG 3 (only one sub-pixel group SPG 3 is marked in FIG. 6 for illustrations). In order to simplify the descriptions, please refer to FIG. 7 which is a schematic diagram of the sub-pixel group SPG 3 shown in FIG. 6 . In FIG. 6 , the sub-pixel group SPG 3 comprises sub-pixels SP 9 -SP 12 . The sub-pixel SP 9 is located at the j column, the i row and the i+1 row and the sub-pixel SP 10 is located at the j+1 column, the i row and the i+1 row. On the other hand, the sub-pixels SP 11 and SP 12 are transversely located at the j+2 column and the j+3 column. Different from the sub-pixel group SPG 1 shown in FIG. 3 , the transverse sub-pixels SP 11 and SP 12 are shifted downward and are located at the i+1 row and the i+2 row, respectively. Via the abovementioned arrangement of the sub-pixels SP 5 -SP 8 , the sub-pixel group SPG 3 is corresponding to two pixels and the aperture ratio of the display device 60 is accordingly increased. The colors and the length-width relationships between the sub-pixels SP 9 -SP 12 of the sub-pixel group SPG 3 can be referred to the sub-pixels SP 1 -SP 4 of the sub-pixel group SPG 1 , and are not narrated herein for brevity.
[0042] In brief, the upright sub-pixels of the sub-pixel group (e.g. the sub-pixels SP 1 and SP 2 , SP 5 and SP 6 or SP 9 and SP 10 ) are located at the rows overlapping at least one of the transverse sub-pixels of the sub-pixel group (e.g. the sub-pixels SP 3 and SP 4 , SP 7 and SP 8 or SP 11 and SP 12 ).
[0043] In an embodiment, a horizontal displacement may exist between the sub-pixel groups SPG 1 located at adjacent rows in the display device 20 shown in FIG. 2 . Please refer to FIG. 8 , which is a schematic diagram of a display device 80 according to an embodiment of the present invention. The display device 80 is similar to the display device 20 shown in FIG. 2 , thus the components and the signals with the same functions use the same symbols. Different from the display device 20 , a horizontal displacement W 1 exists between the sub-pixel groups SPG 1 located at the adjacent rows (e.g. the sub-pixel groups SPG 1 located at the i row and the i+1 row and those located at the i+2 row and the i+3 row). In this embodiment, the horizontal displacement W 1 is one-fourth of the width of the sub-pixel group SPG 1 . As a result, the display device 80 equipping different sub-pixel arrangement can be realized by the sub-pixel group SPG 1 .
[0044] Please refer to FIG. 9 , which is schematic diagram of a display device 90 according to an embodiment of the present invention. The display device 90 is similar to the display device 20 shown in FIG. 2 , thus the components and the signals with the same functions use the same symbols. Different from the display device 20 , a horizontal displacement W 2 exists between the sub-pixel groups SPG 1 located at the adjacent rows (e.g. the sub-pixel groups SPG 1 located at the i row and the i+1 row and those located at the i+2 row and the i+3 row). In this embodiment, the horizontal displacement W 2 is half of the width of the sub-pixel group SPG 1 . Note that, a sub-pixel group SPGC 1 shown in FIG. 9 can be regarded as the repeated sub-pixel group in this embodiment. As a result, the display device 90 equipping different sub-pixel arrangement can be realized by the sub-pixel group SPG 1 .
[0045] In an embodiment, a horizontal displacement may exist between the sub-pixel groups SPG 1 located at the adjacent rows and a vertical displacement may exist between sub-pixels in the display device 20 shown in FIG. 2 . Please refer to FIG. 10 , which is a schematic diagram of a display device 100 according to an embodiment of the present invention. The display device 100 may be an electronic device with a liquid crystal panel, such as a television, a smart phone or a tablet. As shown in FIG. 10 , the sub-pixel groups located at the adjacent rows are the sub-pixel group SPG 2 and the sub-pixel group SPG 3 shown in FIG. 7 , respectively. As a result, the display device 100 equips the sub-pixel arrangement different from that of the display device 20 .
[0046] In order to simplify the complexity of the circuit layout in the display device, the sub-pixels of the repeating sub-pixel groups may be divided into multiple secondary sub-pixels. Please refer to FIG. 11 , which is a schematic diagram of a display device 110 according to an embodiment of the present invention. The display device 110 may be an electronic device with a liquid crystal panel, such as a television, a smart phone or a tablet. FIG. 11 only shows parts of sub-pixels of the display device 110 for illustrations. Note that, FIG. 11 is utilized for illustrating the relative positions of the sub-pixels and not for limiting the ratio between length and width. As shown in FIG. 11 , the display device 110 comprises a plurality of repeating sub-pixel groups SPG 4 (only one sub-pixel group SPG 4 is marked in FIG. 11 for illustrations). In order to simplify the descriptions, please refer to FIG. 12 which is a schematic diagram of the sub-pixel group SPG 4 shown in FIG. 11 . In FIG. 12 , the sub-pixel group SPG 4 comprises sub-pixels SP 13 -SP 16 and the arrangement of the sub-pixels SP 13 -SP 16 is similar to that of the sub-pixels SP 1 -SP 4 shown in FIG. 3 . In comparison with the sub-pixel group SPG 1 shown in FIG. 3 , the sub-pixel SP 13 of the sub-pixel group SPG 4 is divided into secondary sub-pixels SP 13 A and SP 13 B; and the sub-pixel SP 14 is divided into secondary sub-pixels SP 14 A and SP 14 B. In this embodiment, the colors of the secondary sub-pixels SP 13 A and SP 13 B equal that of the sub-pixel SP 13 and the colors of the secondary sub-pixels SP 14 A and SP 14 B also equal that of the sub-pixel SP 14 . Via dividing the sub-pixels SP 13 and SP 14 , the aperture ratio of the display device 110 is further improved.
[0047] The driving module (e.g. a driving integrated chip (IC)) of the display device may need to be appropriately altered according to the sub-pixel arrangement of the above embodiments. Please jointly refer to FIG. 3 and FIG. 13 , wherein FIG. 13 is a schematic diagram of a circuit layout of the display device 90 shown in FIG. 9 . As shown in FIG. 13 , the display device 90 comprises a driving module DRI and a plurality of sub-pixel groups SPG 1 . The driving module DRI comprises a column driving unit CD and a row driving unit RD, which are utilized for driving data lines DL 1 -DLx and scan lines SLm-SLy, respectively. Note that, FIG. 13 only shows the data line DLn-DLn+9, the scan lines SLm-SLm+4 and parts of the plurality of sub-pixel groups SPG 1 for illustrations. In the sub-pixel group SPG 1 at the upper left corner, the sub-pixel SP 1 is coupled to the data line DLn and the scan line SLm; the sub-pixel SP 2 is coupled to the data line DLn+1 and the scan line SLm+1; the sub-pixel SP 3 is coupled to the data line DLn+2 and the scan line SLm; and the sub-pixel SP 4 is coupled to the data line DLn+3 and the scan line SLm+1. The relationships between the data lines DLn-DLn+9, the scan lines SLm-SLm+4 and the rest of the sub-pixel groups SPG 1 in FIG. 13 can be acquired by analogy. In brief, the sub-pixels SP 1 and SP 3 are coupled to the same scan line (e.g. the scan line SLm) and the sub-pixels SP 2 and SP 4 are coupled to another adjacent scan line (e.g. the scan line SLm+1). In addition, the sub-pixels SP 1 -SP 4 of the sub-pixel group SPG 1 are respectively coupled to the nearest data lines. As a result, the circuit layout of the display device 90 realized by repeatedly arranging the sub-pixel group SPG 1 can be optimized.
[0048] Please jointly refer to FIG. 12 and FIG. 14 , wherein FIG. 14 is a schematic diagram of a circuit layout of the display device 110 shown in FIG. 11 . As shown in FIG. 14 , the display device 110 comprises a driving module DRI and a plurality of sub-pixel groups SPG 4 . The driving module DRI comprises a column driving unit CD and a row driving unit RD, which are utilized for driving data lines DL 1 -DLx and scan lines SLm-SLy, respectively. Note that, FIG. 14 only shows thee data line DLn-DLn+9, scan lines SLm-SLm+4 and parts of the plurality of sub-pixel groups SPG 4 for illustrations. In the sub-pixel group SPG 4 at the upper left corner, the secondary sub-pixels SP 13 A and SP 13 B are coupled to the data line DLn and the scan line SLm; the secondary sub-pixels SP 14 A and SP 14 B are coupled to the data line DLn+1 and the scan line SLm; the sub-pixel SP 15 is coupled to the data line DLn+2 and the scan line SLm; and the sub-pixel SP 16 is coupled to the data line DLn+3 and the scan line SLm. The relationships between the data lines DLn-DLn+9, the scan lines SLm-SLm+4 and the rest of the sub-pixel groups SPG 4 in FIG. 14 can be acquired by analogy. In comparison with the display device 90 shown in FIG. 13 , the sub-pixels SP 13 -SP 16 are coupled to the same scan line (e.g. the scan line SLm). As a result, the circuit layout of the display device 110 realized by repeatedly arranging the sub-pixel group SPG 4 can be optimized.
[0049] Please refer to FIG. 15 , which is a schematic diagram of a display device 150 according to an embodiment of the present invention. The display device 150 may be an electronic device with a liquid crystal panel, such as a television, a smart phone or a tablet. FIG. 15 only shows parts of sub-pixels of the display device 150 for illustrations. Note that, FIG. 15 is utilized for illustrating the relative positions of the sub-pixels and not for limiting the ratio between length and width. As shown in FIG. 15 , the display device 150 comprises a plurality of repeating sub-pixel groups SPG 5 (only one sub-pixel group SPG 5 is marked in FIG. 15 for illustrations). In order to simplify the descriptions, please refer to FIG. 16 which is a schematic diagram of the sub-pixel group SPG 5 shown in FIG. 15 . In FIG. 16 , the sub-pixel group SPG 5 comprises sub-pixels SP 17 -SP 23 . The sub-pixel SP 17 is located at the j column, the i row and the i+1row; the sub-pixel SP 18 is transversely located at the j+1 column, the j+2 column and the i row; the sub-pixel SP 19 is transversely located at the j+1 column, the j+2 column and the i+1 row; the sub-pixel SP 20 is located at the j+3 column, the i row and the i+1row; the sub-pixel SP 21 is located at the j+4 column, the i row and the i+1row; the sub-pixel SP 22 is located at the j+5 column, the i row and the i+1row; and the sub-pixel SP 23 is located at the j+6 column, the i row and the i+1row. In addition, the adjacent sub-pixels in the sub-pixel group SPG 5 are corresponding to different colors. In this embodiment, the sub-pixels SP 17 -SP 23 are corresponding to blue, red, green, blue, green, red and green, respectively. In such a condition, the sub-pixels SP 17 -SP 19 and SP 18 - 20 respectively generate virtual pixels (i.e. 4 sub-pixels are corresponding to 2 pixels) and sub-pixels SP 20 - 22 , SP 21 -SP 23 and SP 22 - 23 generate real pixels (i.e. 3 sub-pixels corresponding to 1 pixel). Via the arrangement shown in FIG. 16 , the sub-pixel group SPG 5 generates 4 pixels via 7 sub-pixels. Under the condition that the resolution of the display device 150 is constant, the number of the sub-pixels utilized for realizing the display device 150 is reduced and the aperture ratio of the display device 150 is accordingly increased.
[0050] According to different applications and design concepts, the colors of the sub-pixels SP 17 -SP 23 in the sub-pixel group SPG 5 can be appropriately altered. Please refer to FIG. 17 , which is a schematic diagram of another color configuration of the sub-pixel group SPG 5 shown in FIG. 16 . Different from FIG. 16 , the sub-pixel 19 of the sub-pixel group SPG 5 shown in FIG. 17 is changed to be corresponding to white. In another embodiment, the sub-pixel SP 19 is corresponding to yellow. That is, the sub-pixels SP 17 -SP 23 are corresponding to at least three colors and the adjacent sub-pixels in the sub-pixel group SPG 5 are corresponding to different colors.
[0051] In an embodiment, a horizontal displacement may exist between the sub-pixel groups SPG 5 located at the adjacent rows in the display device 150 shown in FIG. 15 . Please refer to FIG. 18 , which is a schematic diagram of a display device 180 according to an embodiment of the present invention. The display device 180 is similar to the display device 150 shown in FIG. 15 , thus the components and the signals with the same functions use the same symbols. Different from the display device 150 , a horizontal displacement W 3 exists between the sub-pixel groups SPG 5 located at the adjacent rows (e.g. the sub-pixel groups SPG 5 located at the i row and the i+1 row and those located at the i+2 row and the i+3 row). In this embodiment, the horizontal displacement W 3 is three-seventh of the width of the sub-pixel group SPG 5 . Note that, a sub-pixel group SPGC 2 shown in FIG. 18 can be regarded as the repeating sub-pixel group of the display device 180 . As a result, the display device 180 equips different sub-pixel arrangement can be realized by the sub-pixel group SPG 5 (or the sub-pixel group SPGC 2 ).
[0052] Please refer to FIG. 19 , which is a schematic diagram of a display device 190 according to an embodiment of the present invention. The display device 190 is similar to the display device 150 shown in FIG. 15 , thus the components and the signals with the same functions use the same symbols. Different from the display device 150 , a horizontal displacement W 4 exists between the sub-pixel groups SPG 5 located at the adjacent rows (e.g. the sub-pixel groups SPG 5 located at the i row and the i+1 row and those located at the i+2 row and the i+3 row). In this embodiment, the horizontal displacement W 4 is four-seventh of the width of the sub-pixel group SPG 5 . Note that, a sub-pixel group SPGC 3 shown in FIG. 19 can be regarded as the repeating sub-pixel group of the display device 190 . As a result, the display device 190 equips different sub-pixel arrangement can be realized by the sub-pixel group SPG 5 (or the sub-pixel group SPGC 3 ).
[0053] Please note that, the sub-pixels generating the virtual pixels are surrounded by the sub-pixels generating the real pixels in FIG. 19 .
[0054] Please refer to FIG. 20 , which is a schematic diagram of a circuit layout of the display device 190 shown in FIG. 19 . The display device 190 is similar to the display device 90 shown in FIG. 13 , thus the components with the similar functions use the same symbols. As shown in FIG. 20 , the display device 190 comprises a driving module DRI and a plurality of sub-pixel groups SPG 5 . The driving module DRI comprises a column driving unit CD and a row driving unit RD, which are utilized for driving data lines DL 1 -DLx and scan lines SLm-SLy, respectively. Note that, FIG. 20 only shows thee data line DLn-DLn+9, scan lines SLm-SLm+4 and parts of the plurality of sub-pixel groups SPG 5 for illustrations. In the sub-pixel group SPG 5 at the upper left corner, the sub-pixel SP 17 is coupled to the data line DLn and the scan line SLm; the sub-pixel SP 18 is coupled to the data line DLn+1 and the scan line SLm; the sub-pixel SP 19 is coupled to the data line DLn+2 and the scan line SLm+1; the sub-pixel SP 20 is coupled to the data line DLn+3 and the scan line SLm; the sub-pixel SP 21 is coupled to the data line DLn+4 and the scan line SLm; the sub-pixel SP 22 is coupled to the data line DLn+5 and the scan line SLm; and the sub-pixel SP 23 is coupled to the data line DLn+6 and the scan line SLm. The relationships between the data lines DLn-DLn+9, the scan lines SLm-SLm+4 and the rest of the sub-pixel groups SPG 5 in FIG. 20 can be acquired by analogy. In the sub-pixel group SPG 5 , the sub-pixels SP 17 , SP 18 , SP 21 -SP 23 are coupled to the same scan line and the sub-pixel SP 19 is coupled to another adjacent scan line. As a result, the circuit layout of the display device 190 realized by repeatedly arranging the sub-pixel group SPG 5 can be optimized.
[0055] According to different applications and design concepts, those with ordinary skill in the art may observe appropriate alternations and modifications. For example, the sub-pixel groups located at the adjacent rows in the display device may have different color arrangements. Please refer to FIG. 3 and FIG. 21 , wherein FIG. 21 is a schematic diagram of another implementation of the display device 80 shown in FIG. 8 . Different from FIG. 8 , the sub-pixel groups SPG 1 located at the adjacent rows equip different color arrangements in FIG. 21 . As shown in FIG. 21 , the sub-pixels SP 1 -SP 4 in the sub-pixel groups SPG 1 located at the i row and the i+1 row are corresponding to blue, white, red and green; and the sub-pixels SP 1 -SP 4 in the sub-pixel groups SPG 1 located at the i+2 row and the i+3 row are corresponding to white, blue, red and green.
[0056] Please refer to FIG. 16 and FIGS. 22A-22C , wherein FIGS. 22A-22C are schematic diagrams of other implementations of the display device 190 shown in FIG. 19 . Different from FIG. 19 , the sub-pixel groups SPG 5 of different rows in FIGS. 22A-22C have different color arrangements. As shown in FIG. 22A , the sub-pixels SP 17 -SP 23 of the sub-pixel groups SPG 5 located at the i row and the i+1 row are corresponding to blue, red, green, blue, greed, red and green; and the sub-pixels SP 17 -SP 23 of the sub-pixel groups SPG 5 located at the i+2 row and the i+3 row are corresponding to red, blue, green, red, green, blue, and green. In FIG. 22B , the sub-pixels SP 17 -SP 23 of the sub-pixel groups SPG 5 located at the i row and the i+1 row are corresponding to blue, red, white, blue, greed, red and green; and the sub-pixels SP 17 -SP 23 of the sub-pixel groups SPG 5 located at the i+2 row and the i+3 row are corresponding to red, blue, white, red, green, blue, and green. In FIG. 22C , the sub-pixels SP 17 -SP 23 of the sub-pixel groups SPG 5 located at the i row and the i+1 row are corresponding to blue, red, green, blue, greed, red and green; and the sub-pixels SP 17 -SP 23 of the sub-pixel groups SPG 5 located at the i+2 row and the i+3 row are corresponding to blue, green, red, blue, green, red, and green.
[0057] To sum up, the above embodiments reduce the number of sub-pixels for realizing the display device via altering the sub-pixel arrangement in the display device, so as to increase the aperture ratio and to decrease the power consumption and the layout area of the display device. Moreover, the brightness of the display device is increased and the power consumption is further decreased via adding the sub-pixels corresponding to white.
[0058] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. | A display device including a plurality sub-pixel groups is disclosed. Each of the plurality sub-pixel groups includes a first sub-pixel, locating at a first column, a first row and a second row adjacent to the first row; a second sub-pixel, locating at a second column adjacent to the first column, the first row and the second row; a third sub-pixel locating at a third column adjacent to the second column and a first row; and a fourth sub-pixel locating at the third column and the second row. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a technique of using a plasma generator to purify exhaust gas discharged from an internal combustion engine.
2. Description of the Related Art
There is proposed a method of using plasma for an exhaust gas purifying technique of a lean burn engine (mainly Diesel engine). The method of using the plasma is a technique in which electromagnetic energy is imparted to the exhaust gas by discharge to put the exhaust gas into a plasma state, and thereby decomposition reaction of toxic substances is promoted to generate a direct purification reaction or a purification reaction with a catalyst or the like (for example, see Japanese Patent Publication Laid-Open No. H6-10652).
Usually a method in which the alternating current discharge is utilized to generate the plasma, and there are proposed many techniques of controlling the plasma conditions improve purification efficiency (for example, see Japanese Patent Publication Laid-Open Nos. H5-59934 and 2001-46910).
Japanese Patent Publication Laid-Open No. H5-59934 discloses a configuration in which corona discharge is applied to the exhaust gas of the internal combustion engine to perform denitration. In the configuration, discharge voltage to an electrode which performs the corona discharge is controlled according to an operation condition of the internal combustion engine.
Japanese Patent Publication Laid-Open No. 2001-46910 discloses a technique of controlling an interval of the intermittent discharge corresponding to an exhaust gas flow rate in a configuration in which high alternating-current voltage is applied to the internal combustion engine exhaust gas to perform the intermittent discharge. These techniques are aimed at the improvement of exhaust gas purification efficiency and reduction of electric power consumption.
However, in the conventional techniques, there is a limitation to pursuance of the purification efficiency without largely increasing the electric power consumption. That is, the pursuance of the purification efficiency inevitably leads to the increase in electric power consumption.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of the invention is to provide a technique of enhancing the purification efficiency while the increase in electric power consumption is suppressed in the technique of utilizing the discharge to purify the exhaust gas.
A first aspect of the invention is an exhaust gas purifying apparatus which purifies exhaust gas of an internal combustion engine, the exhaust gas purifying apparatus including a pair of discharge electrode which applies voltage to exhaust gas; voltage control means for controlling a waveform of voltage supplied to the discharge electrode; and detection means for detecting a load on an internal combustion engine, an exhaust gas flow rate, and purification reaction efficiency, wherein a waveform of the voltage has a burst period including a discharge period and an undischarged period, a predetermined basic waveform periodically existing in a repeated manner in the discharge period, the discharge being not performed in the undischarged period, and the voltage control means responds to output of the detection means to adjust an amplitude, a period, and a continuous iteration count of the basic waveform and a length of the burst period.
For example, the load on the internal combustion engine is detected by detecting the concentration of PM (Particulate Matter, for example, soot) included in the exhaust gas discharged from the internal combustion engine. In this case, it is determined that the high load is applied on the Diesel engine when the PM concentration is high, and it is determined that the low load is applied on the Diesel engine when the PM concentration is low. Alternatively, a method of detecting the exhaust gas concentration and a method of detecting a torque load on the internal combustion engine can be cited as an example of the method of detecting the load.
The purification reaction efficiency shall mean purification efficiency of the purifying target substance which is obtained as a result of the discharge to the exhaust gas. The PM removal efficiency can be cited as an example of the purification reaction efficiency.
The terminology used in the specification will be described below. The basic waveform shall mean a minimum unit of waveform which does not include two or more waveforms having periodicities in itself, and the basic waveform is defined by a one-period waveform having the periodicity such as a sine wave, a rectangular wave, a triangular wave, and a pulse wave. FIG. 1 is a conceptual view explaining the discharge waveform utilized. In FIG. 1 , the basic waveform designated by the numeral 101 is illustrated as the minimum unit of waveform.
The discharge period shall mean a period during which the basic waveform is continuously repeated as a unit of one period. The undischarged period shall mean a period during which the discharge is not performed. For example, FIG. 1 shows the discharge period during which the iteration count of the basic waveform 101 is five times and the discharged period during which the iteration count is three times.
The burst period is defined by a period including the one-time discharge period and the subsequent undischarged period. A length ratio of the discharge period and the undischarged period can arbitrarily be adjusted. For example, in the state in which the burst period is fixed, when the discharge period is lengthened, the undischarged period is shortened. The basic waveform iteration count shall mean the number of times in which the one-period basic waveform is continuously repeated.
In the first aspect of the invention, the load on the internal combustion engine, the exhaust gas flow rate, and the purification reaction efficiency are detected, and the amplitude, the period, and the continuous iteration count of the basic waveform and the length of burst period are adjusted based on the detection values.
As described later, in the intermittent discharge in which the discharge period and the undischarged period are combined, the purification efficiency can be improved by increasing the discharge voltage (basic waveform amplitude). Furthermore, at this point, the purification efficiency can be enhanced while the increase in electric power consumption is suppressed by decrementing the basic waveform iteration count. That is, the discharge voltage is increased and the discharge period is shortened, which allows the purification efficiency to be enhanced without increasing the electric power consumption.
The increase in discharge voltage produces an effect of enhancing the instantaneous discharge energy to increase discharge density. A method of increasing an iteration frequency of the basic waveform (method of shortening the basic waveform period) can also be adopted as the method of enhancing the discharge density.
As described later, the purification efficiency of the toxic substance can be pursued while the electric power consumption is suppressed by optimizing the burst period.
Thus, the removal efficiency of the toxic substance in the exhaust gas is compatible with the suppression of the electric power consumption by adjusting the amplitude, the period, and the continuous iteration count of the basic waveform and the length of burst period.
A second aspect of the invention is an exhaust gas purifying apparatus which purifies exhaust gas of an internal combustion engine, the exhaust gas purifying apparatus including a pair of discharge electrode which applies voltage to exhaust gas; voltage control means for controlling a waveform of voltage supplied to the discharge electrode; and detection means for detecting a load on an internal combustion engine, an exhaust gas flow rate, and purification reaction efficiency, wherein a waveform of the voltage has a burst period including a discharge period and an undischarged period, a predetermined basic waveform periodically existing in a repeated manner in the discharge period, the discharge being not performed in the undischarged period, and the voltage control means controls: (1) an amplitude and/or a period of the basic waveform according to the load on the internal combustion engine; (2) a continuous iteration count of the basic waveform according to the purification reaction efficiency; and (3) the burst period according to the exhaust gas flow rate.
There are various parameters which have an influence on the purification efficiency. In the case where the purification efficiency is simply pursued, the input electric power is also increased according to the purification efficiency. According to the second aspect of the invention, the purification efficiency can be pursued while the increase in input electric power is suppressed by properly selecting the target which should be controlled according to the sensed physical value. That is, in the second aspect of the invention, when the load on the internal combustion engine is increased, the basic waveform amplitude is increased and/or the basic waveform period is shortened, and thereby the discharge energy density is increased. Therefore, the decrease in purification efficiency can be suppressed in association with the increase in load. When the load on the internal combustion engine is decreased, it is necessary that the basic waveform amplitude be decreased and/or the basic waveform period be lengthened.
The purification reaction efficiency is monitored, and the basic waveform iteration count is incremented when the purification reaction efficiency is decreased to a predetermined value. In this case, because the discharge period is lengthened in the burst period, the discharge is applied to the exhaust gas for a longer time. That is, when the purification reaction efficiency is decreased, the basic waveform iteration count is incremented to suppress the decrease in discharge efficiency. In this case, because the undischarged period during which the discharge is not performed exists after the discharge period during which the basic waveform is repeated, the purification efficiency can be secured while the input electric power is saved. When the purification efficiency exceeds a predetermined value, it is necessary to decrement the basic waveform iteration count.
The meaning that the basic waveform iteration count is adjusted according to the purification efficiency will be described below. The purification efficiency can also be enhanced by adjusting the voltage of the basic waveform. However, it is not proper to excessively increase the basic waveform due to a restriction of power supply voltage or a restriction of withstanding voltage of an oscillation system device. In the invention, a role is divided such that the basic waveform voltage is adjusted according to the loaded condition while the necessary reaction efficiency is adjusted by the basic waveform iteration count. Thus, in the restriction of the power supply voltage or the restriction of the withstanding voltage of the oscillation system device, the high purification efficiency can be obtained while the low electric power consumption is pursued.
The exhaust gas flow rate is monitored, and the burst period is shortened when the exhaust gas flow rate is increased. Therefore, the discharge electric power density per unit time can be increased to respond to the increase in exhaust gas flow rate. When the exhaust gas flow rate is decreased, it is necessary to lengthen the burst period.
For example, it is also possible to respond to the increase in exhaust gas flow rate by the method of increasing the discharge voltage, the method of increasing the iteration frequency of the basic waveform, and the method of incrementing the basic waveform iteration count. However, as described above, because there is the limitation to the increase in basic waveform voltage, it is not proper to increase the basic waveform voltage to respond to the increase in exhaust gas flow rate. Because the iteration frequency of the basic waveform is restricted by a composition and pressure of a discharge atmosphere from the need to stably perform the discharge, it is also not proper to increase the iteration frequency of the basic waveform according to the flow rate. Because the excessive increment of the basic waveform iteration count leads to the decrease in undischarged period, form the viewpoint of pursuance of the low electric power consumption, it is not preferable that the basic waveform iteration count be excessively incremented. Accordingly, it is preferable to change the burst period to deal with the increase in exhaust gas flow rate.
Thus, both the purification efficiency and the low electric power consumption can be pursued by limiting the parameter according to the sensed parameter.
An example of the discharge waveform used in the invention will briefly be described below. FIG. 2 is a conceptual view showing an example of the discharge waveform. FIG. 2A shows the basic waveform having the iteration count of twice.
For example, in the low loaded condition, it is assumed that the discharge is performed with the discharge waveform shown in FIG. 2A . In this state of things, it is assumed that the load is increased to increase the exhaust gas flow rate. For the increase in load, the control is performed such that the iteration frequency of the basic waveform is increased while the basic waveform voltage (amplitude) is increase. For the increase in exhaust gas flow rate, the control is performed such that the burst period is shortened.
FIG. 2B shows an example of the discharge waveform after the control is performed to the discharge waveform shown in FIG. 2A . When compared with the discharge waveform shown in FIG. 2A , the discharge waveform shown in FIG. 2B is set such that the basic waveform voltage is increased while the basic waveform period is shortened. The burst period is also shortened.
It is considered that the load is further increased from the state shown in FIG. 2B . In this case, the control is performed such that the iteration frequency of the basic waveform is further increased while the basic waveform voltage (amplitude) is further increase. FIG. 2C shows the discharge waveform which is outputted by performing the control. When compared with the discharge waveform shown in FIG. 2B , the discharge waveform shown in FIG. 2C is set such that the basic waveform voltage is increased while the basic waveform period is shortened.
In the first aspect or second aspect of the invention, an exhaust gas purifying apparatus may include electrode temperature detection means for detecting a temperature of the discharge electrode, wherein the voltage control means controls the continuous iteration count of the basic waveform and the burst period according to the temperature of the discharge electrode.
For example, when the continuous use of the plasma or excessive injection of the discharge energy is generated, the temperature of the discharge electrode is raised. When the temperature of the discharge electrode is raised, a rate of thermionic emission is increased, and there is a strong tendency to consume the discharge energy in the form of heat. Therefore, the removal efficiency of the toxic substance is decreased.
Accordingly, the discharge electrode temperature is monitored, and the continuous iteration count of the basic waveform is decremented and/or the burst period is lengthened when the temperature is raised with respect to the steady state. This enables the energy high-density state to be maintained in the discharge period. On the other hand, the undischarged period is relatively lengthened, and the lengthened undischarged period becomes a cooling period to suppress the temperature rise of the discharge electrode.
The temperature is raised in a space between the discharge electrodes as the temperature of the discharge electrode is raised. As a result, a difference in gas temperature between the pre-plasma process and the post-plasma process is increased compared with the steady state. For example, the method of detecting the temperature of the discharge space (plasma generation vessel) and the method of detecting the difference in gas temperature between the pre-plasma process and the post-plasma process can be cited as an example of the method of detecting the discharge electrode temperature.
The discharge electrode temperature can be actively controlled by utilizing this mode. For example, in the case where an exothermic reaction of a plasma reaction component is locally generated in a concentrated manner or in the case where the exhaust gas temperature is rapidly raised, the discharge electrode temperature is rapidly raised, and sometimes the discharge leads to an arc discharge. The arc discharge is not suitable to the exhaust gas purification, because plasma generation efficiency becomes worsened to induce the decrease in purification efficiency. In this case, the continuous iteration count of the basic waveform and the burst period are controlled according to the discharge electrode temperature, which allows the discharge electrode temperature to be adjusted at a predetermined appropriate temperature. This enables the electrode temperature suitable for the effective discharge to be set.
According to the invention, the removal efficiency of the toxic substance in the exhaust gas is compatible with the suppression of the electric power consumption by adjusting the amplitude, the period, and the continuous iteration count of the basic waveform and the length of burst period.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a conceptual view explaining a discharge waveform utilized in the invention;
FIG. 2 is a conceptual view explaining types of the discharge waveform utilized in the invention;
FIG. 3 is a block diagram showing an example of an exhaust gas purifying system in which the invention is utilized;
FIG. 4 is a conceptual view showing an example of a plasma generator;
FIG. 5 is a flowchart showing an operation example of the exhaust gas purifying system shown in FIG. 3 ;
FIG. 6 shows data of a PM purification ratio in each example; and
FIG. 7 is a data plot showing a relationship between a burst period and the PM purification ratio.
DESCRIPTION OF THE PREFERRED EMBODIMENT
(1) Embodiment
(Configuration of Embodiment)
An example in which an exhaust gas purifying apparatus according to the invention is applied to a system for removing PM (Particulate Matter, the soot is the target in this case) contained in the exhaust gas of the Diesel engine will be described below.
FIG. 3 is a block diagram showing an example of an exhaust gas purifying system in which the invention is utilized. A Diesel engine 301 , a PM concentration sensor 302 , a flow rate sensor 303 , a plasma generator 304 , a PM concentration sensor 305 , a loaded condition computing device 306 , a reaction efficiency computing device 307 , a voltage control device 308 , and a temperature sensor 309 are shown in FIG. 3 .
An automobile engine, a truck engine, a bus engine, a railroad vehicle engine, a shipping engine, and a power generator engine can be cited as an example of Applications of the Diesel engine 301 . In the embodiment, the exhaust gas discharged from the Diesel engine 301 flows sequentially through the PM concentration sensor 302 , the flow rate sensor 303 , the plasma generator 304 , and the PM concentration sensor 305 . The exhaust gas flowing out from the PM concentration sensor 305 is discharged to an environment through a catalyst converter or a silencer (not shown).
The PM concentration sensor 302 detects a PM concentration in the exhaust gas discharged from the Diesel engine 301 before the exhaust gas enters the plasma generator 304 . The PM concentration sensor 302 sends the detection value of the PM concentration to the loaded condition computing device 306 and the reaction efficiency computing device 307 . The flow rate sensor 303 detects a flow rate of the exhaust gas discharged from the Diesel engine 301 , and the flow rate sensor 303 sends the detection value of the exhaust gas flow rate to the voltage control device 308 .
The plasma generator 304 has a basic structure shown in FIG. 4 , the plasma generator 304 performs the discharge to the exhaust gas to put the exhaust gas into the plasma state, and the plasma generator 304 decomposes PM to purify the exhaust gas. In the action of the embodiment, the exhaust gas is put into the ionized state or activated state, and the soot included in the exhaust gas is changed to carbon monoxide or carbon dioxide. Therefore, the soot existing in the exhaust gas can be purified.
The plasma generator 304 is controlled by the voltage control device 308 . The voltage control device 308 controls a discharge voltage (basic waveform amplitude), an iteration count of a basic waveform, a basic waveform period (iteration frequency) and a burst period. The PM concentration sensor 305 detects the PM concentration in the exhaust gas which passes through the plasma generator, and the PM concentration sensor 305 sends the detection value of the PM concentration to the reaction efficiency computing device 307 .
The loaded condition computing device 306 computes a loaded condition of the Diesel engine 301 based on the PM concentration detected by the PM concentration sensor 302 . At this point, it is determined that the high load is applied on the Diesel engine 301 when the PM concentration is high, and it is determined that the low load is applied on the Diesel engine 301 when the PM concentration is low. The loaded condition computing device 306 includes a memory in which a data table is stored. A relationship between the PM concentration and the loaded condition is determined by the data table. The loaded condition is computed from the detected PM concentration using the data table.
The reaction efficiency computing device 307 compares the PM measurement value of the PM concentration sensor 302 and the PM measurement value of the PM concentration sensor 305 to compute PM purification efficiency in the plasma generator 304 . The reaction efficiency computing device 307 sends the computation result to the plasma generator 304 .
The voltage control device 308 controls discharge conditions of the plasma generator 304 . The voltage control device 308 performs the controls based on the loaded condition computed by the loaded condition computing device 306 , the reaction efficiency computed by the reaction efficiency computing device 307 , the exhaust gas flow rate outputted from the flow rate sensor 303 , and electrode temperature detected by the temperature sensor 309 . Contents of the control will be described later.
The voltage control device 308 includes CPU (not shown), a memory (not shown), and an interface (not shown). CPU controls the operation of the later-described contents. A program and various kinds of data are stored in the memory. The interface conducts communication with other devices. The program for determining a processing procedure in the control and the data necessary for the various kinds of control are stored in the memory. That is, the data table for determining the relationship among the loaded condition (or PM concentration), the discharge voltage, and the discharge period, the data table for determining the relationship between the reaction efficiency and the iteration count of the basic discharge waveform, the data table for determining the relationship between the exhaust gas flow rate and the burst period, the data table for determining the relationship among the electrode temperature, the burst period, and the iteration count of the basic discharge waveform are stored in the memory of the voltage control device 308 . The data contents in which the optimum combinations are previously determined by experiments are used as the contents of the data table.
The temperature sensor 309 detects the electrode temperature of the plasma generator 304 , and the temperature sensor 309 sends the detected data to the voltage control device 308 . In the embodiment, the temperature sensor 309 detects the temperature of one of the discharge electrodes as the electrode temperature of the discharge electrode.
FIG. 4 is a conceptual view showing an outline of the plasma generator 304 of FIG. 3 . The plasma generator 304 shown in FIG. 4 includes a positive electrode 401 , a negative electrode 402 , a positive electrode 403 , alumina plates 404 and 405 , discharge spaces 406 and 407 , a voltage generator 408 , and the temperature sensor 309 .
In the plasma generator 304 , the pair of positive electrodes 401 and 403 is arranged so as to sandwich the negative electrode 402 . The negative electrode 402 is connected to a ground potential, and the positive electrodes 401 and 403 are connected to the voltage generator 408 .
The discharges are generated in a discharge space 406 between the positive electrode 401 and the negative electrode 402 and in a discharge space 407 between the positive electrode 403 and the negative electrode 402 . The exhaust gas flows in the discharge spaces 406 and 407 toward a direction shown by arrows 409 , and the discharge is imparted to the exhaust gas in the discharge spaces 406 and 407 . PM (in this case, the target is the soot) included in the exhaust gas is decomposed to purify PM by imparting the discharge to the exhaust gas.
The alumina plates 404 and 405 are arranged over a surface of the positive electrode 401 facing the discharge space 406 and over a surface of the negative electrode 402 facing the discharge space 407 respectively. An abnormal discharge such as an arc discharge can be prevented to realize the stable discharge by arranging the dielectric material such as alumina over the surface on the discharge space side of the electrode.
The voltage generator 408 is controlled by the voltage control device 308 . In the embodiment, the voltage generator 408 generates the later-described voltage waveform to supply the voltage waveform to the discharge electrode (positive electrode 401 and negative electrode 402 ). The target to be controlled includes the amplitude and period (frequency) of the basic waveform, a continuous iteration count of the basic waveform, and the burst period. The temperature sensor 309 detects the temperature of the positive electrode 403 , and the temperature sensor 309 sends the detection signal to the voltage control device 308 .
(Operation of Embodiment)
FIG. 5 is a flowchart showing an operation example of the exhaust gas purifying system shown in FIG. 3 . When the control of the plasma generator 304 is started, the loaded condition of the Diesel engine 301 is obtained (Step S 501 ). In the embodiment, the PM concentration included in the exhaust gas of the Diesel engine 301 is measured by the PM concentration sensor 302 , and the loaded condition is computed based on the measurement value of the PM concentration. In this case, the loaded condition is obtained such that the high load is applied on the Diesel engine 301 when the PM concentration is high and the low load is applied on the Diesel engine 301 when the PM concentration is low.
When the loaded condition is obtained, the data table stored in the memory of the voltage control device 308 is referred to, and the discharge voltage and the discharge period are read according to the loaded condition detected in Step S 501 . The signals indicating the read discharge voltage and discharge period are sent from the voltage control device 308 to the plasma generator 304 . Thus, the discharge voltage and the discharge period are adjusted according to the loaded condition (Step S 502 ).
In Step S 502 , in the case of the large load (in the case of the high PM concentration), the control is performed such that the discharge voltage is increased to shorten the discharge period (discharge period of basic waveform).
Then, the reaction efficiency in the plasma generator 304 is obtained (Step S 503 ). The reaction efficiency computing device 307 compares the detection values of the PM concentrations of the PM concentration sensors 302 and 305 to obtain the reaction efficiency. At this point, the reaction efficiency is increased as the PM concentration detected by the PM concentration sensor 305 becomes lower compared with the PM concentration detected by the PM concentration sensor 302 . The basic discharge waveform iteration count corresponding to the obtained reaction efficiency is read from the memory, and the signal indicating the basic discharge waveform iteration count is sent from the voltage control device 308 to the plasma generator 304 . Thus, the basic discharge waveform iteration count is adjusted based on the reaction efficiency (Step S 504 ).
Then, the exhaust gas flow rate is detected with the flow rate sensor 303 (Step S 505 ). The burst period is read from the memory in the voltage control device 308 according to the detected exhaust gas flow rate, and the signal indicating the burst period is sent from the voltage control device 308 to the plasma generator 304 . Thus, the burst period is adjusted according to the exhaust gas flow rate (Step S 506 ).
In Step S 506 , the adjustment is performed such that the burst period is shortened when the exhaust gas flow rate is increased while the burst period is lengthened when the exhaust gas flow rate is decreased.
The temperature of the positive electrode 403 is detected with the temperature sensor 309 (Step S 506 ), and the burst period and the basic discharge iteration count are adjusted based on the detected temperature (Step S 507 ). At this point, in the case the electrode temperature is raised, the adjustment is performed such that the burst period is lengthened while the basic discharge iteration count is decreased. In the case the electrode temperature is decreased, the reverse adjustment is performed.
It is determined whether or not the control is ended (Step S 508 ). When the control is ended, the operation is ended. When the control is not ended, the flow returns to Step S 501 .
(2) Experimental Result
In the case where the invention is utilized for removing PM (soot in this case) from the exhaust gas, the result that examines the effect will be described below. In this case, the data is collected with the system shown in FIG. 3 .
The conditions on which the data is obtained are as follows. A water-cooled four-cycle Diesel (three cylinders) is used as the Diesel engine 301 . In the water-cooled four-cycle Diesel, a total displacement is 1061 cm 3 , use fuel is Diesel light oil, and rated power is 12 kVA.
The amount of PM in the exhaust gas is measured by a gravimetric method in which PM is collected by a filter (not shown). That is, a predetermined amount of exhaust gas is sampled to collect PM with a commercially available filter (0.3 μm mesh), and a difference in weight before and after the collection is set at the PM weight.
In this case, the positive electrodes 401 and 404 and the negative electrode 402 for formed by a stainless plate having a thickness of 1.0 mm and a size of 20 mm by 50 mm. The alumina plates 404 and 405 have the thickness of 0.5 mm. The space between the alumina plate 404 and the negative electrode 402 and the space between the alumina plate 405 and the positive electrode 403 are set at 0.5 mm respectively.
The exhaust gas flow rate flowing in the plasma generator 304 is set at 8.5 L/min, and the exhaust gas temperature is adjusted at 214° C. by a heater (not shown). The discharge waveform shown in FIG. 1 is set at the burst waveform having the basic waveform of 3000 Hz. Two kinds of voltage values of 6.6 kVp-p and 7.0 kVp-p are used as the basic waveform voltage.
EXAMPLE 1
The basic waveform is set at a 6.6-kVp-P sine wave (3000 Hz), the basic waveform iteration count is set at twice, and the burst period is set at 300 Hz. In this case, the electric power consumption is 4.7 W. In the above conditions, the burst period has the length equal to the ten periods of the basic waveform. Therefore, the undischarged periods of eight basic discharge waveforms 8 remain after the discharge period during which the basic waveform is repeated twice.
EXAMPLE 2
The basic waveform is set at a 7.0-kVp-P sine wave (3000 Hz), the basic waveform iteration count is set at once, and the burst period is set at 300 Hz. In this case, the electric power consumption is 4.5 W.
EXAMPLE 3
The basic waveform is set at the 7.0-kVp-P sine wave (3000 Hz), the basic waveform iteration count is set at twice, and the burst period is set at 300 Hz. In this case, the electric power consumption is 5.3 W.
EXAMPLE 4
The basic waveform is set at the 7.0-kVp-P sine wave (3000 Hz), the basic waveform iteration count is set at three times, and the burst period is set at 300 Hz. In this case, the electric power consumption is 8.7 W.
EXAMPLE 5
The basic waveform is set at the 7.0-kVp-P sine wave (3000 Hz), the basic waveform iteration count is set at twice, and the burst period is set at 150 Hz. In this case, the electric power consumption is 2.6 W.
EXAMPLE 6
The basic waveform is set at the 7.0-kVp-P sine wave (3000 Hz), the basic waveform iteration count is set at twice, and the burst period is set at 600 Hz. In this case, the electric power consumption is 10.6 W.
COMPARATIVE EXAMPLE
The continuous waveform discharge is performed by continuously applying a 6.6-kVp-P sine wave (300 Hz). In this case, the electric power consumption is 5.8 W. Table 1 shows the summary of the conditions, the electric power consumption, and the PM purification ratio of Examples and Comparative Example.
TABLE 1
Comparative
Example 1
Example 2
Example 3
Example 4
Example 5
Example 6
Example
Basic
6.6
7.0
7.0
7.0
7.0
7.0
6.6
waveform
voltage
(kVp-p)
Basic
3000 Hz
3000 Hz
3000 Hz
3000 Hz
3000 Hz
3000 Hz
300 Hz
waveform
frequency
Basic
twice
one
twice
Three
twice
twice
(continuous)
waveform
times
iteration
count
Burst period
300 Hz
300 Hz
300 Hz
300 Hz
150 Hz
600 Hz
(continuous)
Electric
4.7 W
4.5 W
5.3 W
8.7 W
2.6 W
10.6 W
5.8 W
power
consumption
PM
about
about
about
about
about
about
about
purification
75%
83%
88%
92%
67%
86%
50%
ratio
FIG. 6 shows relationship between the PM purification ratio and electric power consumption in Examples 1 to 4 and Comparative Example. FIG. 7 is a data plot showing a relationship between the burst period and the PM purification ratio in Examples 3, 5, and 6. The PM purification ratio is a ratio (in terms of weight) of PM which is decreased by causing the exhaust gas to pass through the plasma generator 407 . Assuming that the amount of PM included in the exhaust gas is set at a pre-plasma process PM amount before the exhaust gas passes through the plasma generator 407 while the amount of PM included in the exhaust gas is set at a post-plasma process PM amount after the exhaust gas passes through the plasma generator 407 , the PM purification ratio is computed by PM purification ratio=100×((pre-plasma process PM amount−post-plasma process PM amount)/pre-plasma process PM amount).
Referring to FIG. 6 , the PM purification ratio is about 75% in Example 1 while the PM purification ratio is about 50% in Comparative Example, and the electric power consumption is 4.7 W in Example 1 while the electric power consumption is 5.8 W. That is, although Example 1 has the low electric power consumption compared with Comparative Example, Example 1 can obtain the higher PM purification ratio.
The difference is attributed to the fact that the intermittent discharge, in which the 3000-Hz basic waveform is repeated twice and then the eight undischarged periods remain, is performed in Example 1 while the 300-Hz basic waveform is continuously oscillated in Comparative Example. It is seen from the above fact that the PM purification can efficiently be performed when the basic waveform frequency is increased to set the undischarged period. In the electric power consuming method, the high-density discharge is performed by combining the basic waveform having the high discharge energy and the undischarged period rather than the electric power is consumed by the continuous basic waveform having the low discharge energy, which allows the efficiency to be increased in the PM purification. That is, the PM purification efficiency can be increased by instantaneously applying the high energy rather than evenly applying the energy.
When compared with Comparative Example, the PM purification ratio is increased although the electric power consumption is small in Example 1. This means that the PM purification ratio of the intermittent discharge is higher than that of the continuous discharge under the same conditions.
The PM purification ratio is about 83% in Example 2 while the PM purification ratio is about50% in Comparative Example, and the electric power consumption is 4.5 W in Example 1 while the electric power consumption is 5.8 W.
Compared with the difference between Examples 1 and 2, not only the electric power consumption is smaller but also the PM purification ratio is larger in Example 2. Example 1 differs from Example 2 in that the basic waveform voltage is 7.0 kVp-p (6.6 kVp-p in Example 1) while the basic waveform iteration count is once in Example 2 (twice in Example 1). That is, in Example 2, the basic waveform voltage is increased by 6% compared with Example 1, and the basic waveform iteration count is decremented from twice to once.
Examples 1 and 2 have the same burst period of 300 Hz. However, in Example 2, the PM purification ratio can be increased while the basic waveform iteration count is decremented. This is attributed to the effect that basic waveform voltage is increased by 6%.
Consequently, it can be concluded that increasing the basic waveform voltage to simultaneously decrease the basic waveform iteration count is effective method of enhancing the PM purification ratio without increasing the electric power consumption under the condition in which the exhaust gas flow rate is kept constant. That is, the PM purification ratio and the low electric power consumption can be pursued by adjusting the basic waveform amplitude and the basic waveform iteration count.
Then, Examples 2 to 4 will be compared to one another. Examples 2 to 4 differ from one another in the condition of the basic waveform iteration count. As can be seen from FIG. 6 , the PM purification ratio is increased as the basic waveform iteration count is incremented. However, an increase rate of the electric power consumption is larger than an increase rate of the PM purification ratio.
Then, Examples 3, 5, and 6 will be compared to one another. Examples 3, 5, and 6 differ from one another in the burst period. The burst period is ( 1/300) second (300 Hz) in Example 3, the burst period is ( 1/150) second (150 Hz) in Comparative Example 5, and the burst period is ( 1/600) second (600 Hz) in Comparative Example 6.
As can be seen from FIG. 7 , the PM purification ratio is decreased when the burst period is shortened to some extent (when time is lengthened in the case where the burst period is expressed by time). As can be seen from the comparison of the Example 3 with Example 6, the burst period has the optimum range in the case where the PM purification ratio and the low electric power consumption are pursued. That is, the number of discharge periods (determined by the basic waveform, the basic waveform period, and the basic waveform iteration count) is determined by setting the burst period. On the other hand, in the case where the actual exhaust gas flow rate is excessive for the exhaust gas flow rate which can be processed during one discharge period, several discharge periods to be generated are required during the exhaust gas passes through the reactor. For example, the desired number of discharge periods is computed based on (actual exhaust gas flow rate/exhaust gas flow rate which can be processed during one discharge period). Accordingly, the burst period is adjusted according to the flow rate of the exhaust gas entering the reactor, so that the optimum number of discharge periods can be set according to the exhaust gas flow rate, and the PM purification ratio and the low electric power consumption can be pursued.
As can be seen from the above demonstration data, in the intermittent discharge mode in which the discharge and the no-yet discharged are alternately repeated, by adjusting the basic discharge waveform voltage, the basic discharge waveform iteration count, and the burst period, the purification efficiency in the plasma reaction can be enhance while the electric power consumption is suppressed.
The invention can be applied to the purification of the exhaust gas discharged from the automobile lean burn engine, the purification of the smoke exhaust discharged from the internal combustion engine installed in the shipping, and the purification of the smoke exhaust discharged from the internal combustion engine of the power generator or the like. | In an exhaust gas purifying technique in which discharge is utilized, the invention provides a technique in which purification efficiency can be enhanced while an increase in electric power consumption is suppressed. A discharge mode including a discharge period and an undischarged period is adopted in a configuration in which a plasma process is performed to exhaust gas from a Diesel engine by generating the discharge in a plasma generator. A basic waveform periodically exists in a repeated manner in the discharge period, and the discharge is not performed in the undischarged period. An amplitude and/or a period of the basic waveform is controlled according to a load on the Diesel engine, a continuous iteration count of the basic waveform is controlled according to purification reaction efficiency in the plasma process, and the burst period is controlled according to an exhaust gas flow rate. | 1 |
FIELD OF THE INVENTION
The invention is directed to manual guidance by the user in control of a computer through a display interface, and in particular to the positioning of a cursor in the display by the movement of a computer mouse and further in particular to the addition of a frictional force component in the mouse movement that improves positioning control and efficiency.
BACKGROUND OF THE INVENTION AND RELATION TO THE PRIOR ART
As progress evolves in the control of a cursor through a display interface of a computer a number of considerations are operating to make accuracy in positioning and in turn user efficiency, increasingly difficult to achieve. In the art, a positioning device called a mouse has evolved that fits in the hand of the user and which has a rotatable element on the under side that rotates against the surface on which the mouse rests when the mouse is moved. The mouse internally has circuitry that provides and transmits signals correlated with the rotatable element movement that results in movement of the cursor or pointer on the display screen.
Switching elements that deliver operating system signals through the mouse-display interface can impose psychomotor limitations for a user. The switches are positioned to be under an adjacent finger when the mouse is in the hand of the user but the actuation force for each switch by the respective finger has force components in more than one direction that can introduce a movement force on the mouse that may disrupt the position of the mouse and in turn the cursor. Other users may have other types of hand coordination problems, making it difficult for them to reach and retain targeted locations with a mouse. Complexity is further added by operating system requirements for such actuation features as “double clicks”. Complexity is still further added by the fact that some users as their experience and skills change could benefit by having some adjustability in the movement response of the mouse.
Operating system controls that are installed to introduce system biases favoring a particular user such as are discussed in U.S. Pat. No. 5,642,131 also recognize that accurate cursor positioning directly to a particular desired location is inefficient because when the user is able to position the cursor close to the desired location overshoot and undershoot make precise positioning of the cursor difficult. Maneuvering the cursor directly to the desired location must be done with care, requiring slower action, which in turn affects productivity and efficiency.
SUMMARY OF THE INVENTION
In the invention, positioning control of a computer mouse is improved by adding a finely adjustable frictional force component to relative motion in the plane of the mouse-supporting surface, or mouse pad, system. The added frictional force component operates to produce a drag component that dampens any forces that would tend to upset the selected mouse position. The frictional force component may be provided, for example by additional small locallized weight increments, the effect of a magnetic field or a change in coefficient of friction between parts that move in relation to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are perspective and side views respectively of a typical prior art computer mouse.
FIGS. 3 and 4 are each a schematic side view of different embodiments of the invention illustrating the addition of positioned mouse housing weight increments.
FIGS. 5 and 6 are each a schematic side view of different embodiments of the invention illustrating the use of a magnetic member on the mouse housing providing attraction to a mouse pad type supporting surface containing a ferromagnetic sheet member.
FIG. 7 is a schematic side view of an embodiment of the invention illustrating the addition of increased friction surfaces to the sliding support faces which in turn increase the static and kinetic coefficients of friction between a mouse and a mouse pad.
DESCRIPTION OF THE INVENTION
In the invention, there is added an adjustable frictional force component in the mouse—mouse pad type supporting surface that improves the positioning control of the mouse by introducing an adjustable drag-type component to the mouse movement in the plane of the mouse—mouse pad interface.
The structural features of a typical mouse are illustrated in connection with FIGS. 1 and 2 which are perspective and side views respectively and which are labelled prior art. Referring to FIG. 1 and FIG. 2 . together; the mouse 100 has a housing that generally fits the hand of the user with the upper curved surface 101 fitting into the heel of the right hand or the left hand of a left handed user. Switches 102 and 103 are provided for the standard clicking functions of the computer and are positioned for actuation by the index and middle fingers of the user. Protrusions 104 and 105 , which are usually of plastic, provide frictional sliding surfaces for the mouse. A curved member with a peripheral surface such as a sphere 106 is rotated by tangential contact of the peripheral surface of the sphere in movement of the mouse over the supporting surface. Position sensing mechanisms and circuitry indicated generally as element 110 within the housing of the mouse 100 convert the motion of the sphere 106 into signals for the computer, resulting in motion of the pointer, or cursor, on a display screen, not shown. The position signals are delivered to the computer through the cable 107 or transmitted by a standard in the art, transmitter, not shown, within the housing of the mouse 100 . The mouse 100 has movement in the plane of a supporting surface 108 , which is typically a mouse pad 108 , which serves as a resilient and uniform friction supplying, supporting surface. For simplicity of description, the supporting surface 108 will be referred to as the mouse pad.
The frictional forces between the lower surfaces of the protrusions 104 and 105 and the upper surface of the mouse pad 108 can be increased by increasing the weight of the mouse. At the present state of the art, the weight of a mouse can be about 100 grams or about 3½ ounces. But at that weight, while light enough to avoid hand fatigue, difficulty in positioning can be encountered.
In accordance with the invention, a fine adjustment in frictional force between the mouse and the supporting surface on which it rests can make a difference between improving positioning accuracy while avoiding hand fatigue. The adjustment in frictional force can be provided in many ways including as examples: by the addition of incremental weights and the removal of some if necessary until an optimum overall weight is achieved; by the introduction of a magnetic field perpendicular to the supporting surface, between the mouse and a supporting surface; or by a change in the coefficient of friction in the mouse-supporting surface interface such as at the mouse support protrusions; or by any combination thereof.
Referring to FIGS. 3 and 4 which are each a schematic side view of different embodiments of the invention illustrating the addition of a selectively positioned mouse housing weight increment of the order of about 20 to 50 grams, which is less than about half the total weight of a typical mouse and which operates to adjust the frictional force in movement between the mouse 100 and the pad or supporting surface 108 .
In the embodiment of FIG. 3 , where like reference numerals are used as in previous figures, the frictional force between the mouse 100 and the mouse pad 108 is adjustably increased by placing a locallized group of small metal pellets 111 having a total weight of about 20 to 50 grams into the mouse housing. The weight of the group of pellets 111 is partially balanced by that of the position sensing circuitry 110 which is usually present in the vicinity of the protrusion 104 . The pellets 111 typically may have a diameter of about ⅛ inch, similar to buck shot. They are usually placed into the housing after first having been placed into a small plastic wrapper to prevent their scattering to the mechanical and electrical components when inside the housing.
In the embodiment of FIG. 4 , where like reference numerals are used as in previous figures, the frictional force for movement between the mouse 100 and the mouse pad 108 is adjustably increased by placing an affixed weight member 112 having a total weight of about 20 to 50 grams over the 101 portion of the housing. 100 . The weight member 112 may consist for example of one or a plurality of about 1 inch diameter metal discs that are cloth or plastic covered.
FIGS. 5 and 6 are each a schematic side view of different embodiments of the invention illustrating the use of a magnetic member on the mouse housing providing attraction to an underlying ferromagnetic sheet within the mouse pad.
Referring to FIG. 5 , where like reference numerals are used as in previous figures, use is made of a localized magnetic field to add frictional force to the motion of the mouse with respect to the mouse pad. FIG. 5 depicts the side view of the mouse 100 that with a permanent magnet element 113 affixed to the portion of the mouse 100 adjacent to the mouse pad 108 in the vicinity of protrusion 104 . The permanent magnet may be a small portion of magnetic sheet material of the type that adheres to steel surfaces by magnetic attraction. The mouse pad 108 contains a sheet of steel or some other ferromagnetic material 114 with a cover such as a cloth. The magnetic attraction between the permanent magnet 113 and the ferromagnetic sheet 114 in the mouse pad 108 increases the downward force, thereby increasing the frictional force in the relative movement between the mouse 100 and the mouse pad 108 , resulting in increased mechanical resistance to any intermittent and unintended the motion of the mouse. In this embodiment, adjustment ability is achieved by reducing or increasing the area and/or thickness of the affixed magnetic element 113 .
In FIG. 6 another embodiment is provided of the use of a locallized magnetic field to provide the added frictional force. In the embodiment of FIG. 6 , the arrangement is also one that is particularly suitable for use in portable and mobile environments. For optimum use in such environments, the mouse is typically cordless in which the cable 107 in previous figures is replaced by a transmitter located in the circuitry 110 . The mouse pad 108 includes a coated or cloth-covered rigid sheet of steel or another ferromagnetic material 114 . The magnetic field is provided by means of a relatively strong permanent magnet 115 such as, for example, a ½ inch diameter disc of SmCo that is screw mounted for adjustment to vary the spacing between the magnet 115 , through the mouse pad 108 cover to the ferromagnetic material 114 . The less the spacing, the greater will be the magnetic attraction. Where the magnetic attraction is increased sufficiently to support the mouse without detachment from its rigid mouse pad over a range of spatial orientations and/or accelerations, the result may be too much frictional force being added to enable comfortable use of the mouse. Such a problem is overcome by providing rollers in place of the usual protrusions. Two such rollers 116 and 117 are indicated in FIG. 6 .
The combination of weight or magnetic attraction is illustrated symbolically in FIGS. 3–6 as an arrow.
Another general way to introduce a frictional force requirement into the interface between between the mouse 100 and the mouse pad 108 is to change the coefficient of friction between mating surfaces. Such an approach is illustrated in connection with FIG. 7 which is a schematic side view of an embodiment of the invention illustrating the addition of increased friction surfaces to the sliding support faces; this operates to increase the static and kinetic coefficients of friction between the support faces of the mouse 100 and the mouse pad 108 .
Referring to FIG. 7 , the increase in coefficients of friction is achieved by affixing elements 118 and 119 of a different friction material such as paper-backed adhesive tape to the portions of the relatively smooth protrusions 104 and 105 , thereby increasing the static and kinetic coefficients of friction between the mouse 100 and the mouse pad 108 .
It will be apparent to one skilled in the art that there will be a wide range of variations within the principles set forth and in addition to the examples listed such mechanisms as the use of hydraulics, pneumatics and viscous fluids may be employed.
Similarly, the principles involving mouse—mouse pad interfaces apply as well to the interfaces of trackballs and other cursor positioning devices.
What has been described is a control principle for a computer mouse that involves adjustably altering a frictional component of the mouse-supporting surface interface. | Control in the positioning of a computer mouse is improved by adding a finely adjusted frictional force component to relative motion in the plane of the mouse-supporting surface, or mouse pad, system. The added frictional force component operates to produce a drag component that dampens the movement. The added frictional force component may be provided by additional small localized weight increments, the effect of a magnetic field, or a change in coefficient of friction between parts that move in relation to each other, as examples. | 6 |
FIELD OF THE INVENTION
The present invention relates generally to radially extensible vane compressors. More particularly, it relates to a system for monitoring the wear of vanes in radially extensible vane compressors.
BACKGROUND OF THE INVENTION
In the field of radially extensible vane compressors, vane wear is a common concern. Due to the great centrifugal forces acting on the vanes, and the great velocity differences between the vanes and the internal walls of the compressor housing that the vanes contact, vanes wear long before the other components of the compressor. Timing of vane replacement has a significant effect on operating costs of the vane compressor. In a typical chemical plant application, the entire process must be stopped for vanes to be replaced, the compressor must be disassembled, and the vanes checked and replaced as necessary. This results in significant downtime for the chemical processing plant, and typically all such repairs are made as rapidly as possible to allow the equipment to be reassembled and brought back up on line as soon as possible. Measuring vane wear typically requires the use of dial indicators, and other measuring instruments that may be easily misread or broken in the haste of checking and repairing the compressor. Alternatively, vane wear may be measured without significantly disassembling the compressor by removing an inspection port of the vane compressor, "bumping" the rotor until it is in the proper rotational position for each vane, and measuring the distance between the edge of the inspection port and the outermost wearing edge of the vane. As the vane wears, this distance will become greater and greater until it finally indicates the need for repair. This process has the disadvantage of requiring careful positioning of the rotor and manipulation of the depth gauge, and has the further disadvantage of requiring subsequent disassembly if the vanes are found to be in need of repair. What is needed is an improved method and apparatus for checking vane wear in a radially extensible vane compressor that is more accurate, that does not require expensive measuring instruments, and is less likely to be misread.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a novel apparatus for measuring vane wear that provides for the above needs.
In accordance with a first embodiment of the invention, a wear indicator is provided having two longitudinal portions, one having an overall width of between 85% and 95% of the other, where the two longitudinal portions are joined at a step. The step may be perpendicular to a wearing edge, or it may be sloped to allow easy withdrawal when compressor wear is tested. The angle of slope is preferably between 3° and 20°, and more preferably between 6° and 16°. To allow easier gas exit from between the slot and the indicator, the transitional portion is preferably radiused, and more preferably has a radius of at least the overall width of the indicator. The step may be disposed at various positions along the length of the indicator to reduce wear caused by rubbing of the indicator step against a mating step on the compressor rotor. The positions at which vibration and therefore wear are minimized are 9%, 13%, 22%, 36%, 50%, 64%, 87% and 92% from either longitudinal end of the indicator.
Other principal features and advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross-sectional perspective view of a compressor in accordance with the present invention;
FIG. 2 is an end view of the FIG. 1 compressor with an end cover removed;
FIG. 3 is a sectional view of the rotor of the embodiment shown in FIGS. 1 and 2;
FIG. 4 is a sectional view of a rotor similar to the rotor of FIG. 3 and an alternative wear indicator;
FIGS. 5A-C are schematic representations of wear indicator oscillation modes;
FIG. 6 is an end view of another compressor utilizing a wear indicator with its end cover removed;
FIG. 7 is a sectional view of the FIG. 6 embodiment; and
FIG. 8 is a sectional view of the indicator and rotor of the FIG. 7 compressor after significant indicator wear.
Before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The subject of this application is generally radially extensible vane compressors. To describe the interrelationship and relative positions of various elements of the various embodiments, certain naming conventions have been chosen. In this description, therefore, the term "axial" refers to the axis of rotation of the compressor rotor. "Longitudinal" or "length" when used in reference to a wear indicator, refers to the extent of a wear indicator in a direction parallel to the rotational axis of the rotor in which the indicator is fitted; this is the largest overall dimension. "Thickness" when used in reference to a wear indicator, refers to the extent of the indicator in a direction orthogonal to its length and width. This is the smallest overall dimension of the wear indicator. "Width" when used in reference to a wear indicator, refers to the extent of the indicator in a direction generally perpendicular to the rotational axis of the rotor in which it is installed. Thickness, length and width, therefore, define three orthogonal extents of the wear indicator.
Turning now to the drawings, FIG. 1 discloses a partial cutaway view of a radially extensible vane compressor in accordance with the present invention. Compressor 10 includes a rotor 12 and vanes 14 and indicator 16 disposed in slots 18 in rotor 12. Here, only three of the eight equiangularly spaced slots are shown. The rotor and vanes rotate within rotor chamber 20 in compressor housing 22. Water passageways 24 are provided between the inner and outer surfaces of housing 22 to contain compressor cooling water. A shaft 26 extending from one end of the rotor passes through the end of housing 22 and through roller bearing 28 in end cover 30. Seals 32 are disposed in end cover 30 and contact shaft 26 to prevent gas leakage. A similar end cover supporting a similar bearing and seal and rotationally supporting a similar shaft extending from the opposing end of the rotor are similarly disposed at the opposing end of the housing. It can be seen that in this compressor, the vanes can only be removed by first removing an end cover of the compressor. Once the end cover is removed, the vanes and the wear indicator can be translated in the slots in a direction parallel to the axis of rotation of the rotor until they are removed from the compressor housing itself.
FIG. 2 is an end view of compressor housing 22 of FIG. 1 illustrating the arrangement of vanes 14 and wear indicator 16 slidingly disposed in slots in the rotor. Eight vanes are disposed in eight slots equiangularly spaced about the rotor. An additional slot 18 is provided for the vane wear indicator 16. The slot in which the wear indicator is disposed preferably has a width W equal to the width of the slots holding vanes 14. The wear indicator is disposed between two of the vanes in the rotor at an angle pi equal to one-half that of angle phi which defines the angular spacing between each adjacent pair of vanes. Since this embodiment has eight vanes, phi is 45° and pi is 22.5°. Although the embodiments shown herein are of compressors with eight vanes, twelve vane compressors with 30° equidistantly spaced vanes would also benefit from the use of wear indicators. In a twelve vane compressor, the equidistant vane spacing is 30°, and a wear indicator would preferably be provided at a position equidistant between two adjacent vanes.
FIG. 3 illustrates a plan view of wear indicator 16 and a sectional view of rotor 12 taken at Section 3--3 in FIG. 2. Wear indicator 16 is shown here inserted almost to the bottom of slot 18 of rotor 12 in which it is disposed. Wear indicator 16 has a wearing edge 34 that is disposed against inner cylindrical surface 36 (FIG. 2) of housing 22. Slot edge 38 opposes wearing edge 34 and is adapted to be received in slot 18 in rotor 12. Slot edge 38 has a step 40 disposed substantially midway along the length of wear indicator 16. Step 40 divides the vane into two longitudinal portions, a wider portion having an overall width W and a narrower portion having an overall width X, where X preferably ranges between 85% and 95% of W. A mating step 42 is provided in rotor 12 at the bottom of slot 18 to engage with step 40 on wear indicator 16.
FIG. 4 illustrates an alternative embodiment of wear indicator 16. Wear indicator 16 is similarly inserted into slot 18 in rotor 12. In this embodiment, however, step 40 is provided by a transitional portion 44 of slot edge 38 having a radius of curvature R at least as great as the overall width W of wear indicator 16. This radius allows the gas otherwise trapped behind indicator 16 to flow smoothly out from between the indicator and its slot when the indicator is forced back into the slot. Transitional portion 44 preferably has an overall slope S of between 3° and 20°, and more preferably between 6° and 16°. This slope provides a downward force on indicator 16 whenever a repairman checks the vane wear by attempting to withdraw the indicator as described below in conjunction with FIGS. 6-8. If step 40 was abrupt, as seen in FIG. 3, it may catch on mating step 42 even if the indicator is worn sufficiently. This would lead a repairman to believe the indicator is not sufficiently worn, when in fact it is. This transitional portion 44 mates with similarly radiused portion 46 of the bottom of slot 18. As in the previous example, step 40 subdivides the longitudinal extent of wear indicator 16 into a portion with an overall width W and a portion with an overall width X equal to 85% to 95% of W.
The longitudinal positioning of step 40 is critical to the proper operation of the wear indicator. As can be seen in FIG. 4, the transitional portion 44 is disposed to intersect the longitudinal midpoint of wear indicator 16, here identified as 48. As the rotor rotates within the compressor cavity, opposing ends 50, 52 of wear indicator 16 make intermittent contact with covers 30 (FIG. 1). Covers 30 contact ends 50, 52 intermittently during the operation of the compressor applying rubbing forces in a direction parallel to the thickness of the wear indicator as the compressor operates. Since the thickness is the smallest overall dimension, and since the covers apply rubbing forces to opposing ends perpendicular to the greatest extent of the indicator, wear indicator 16 will flex within slot 18 in several oscillatory modes of vibration much as a diving board flexes when a diver leaps. Since opposing ends 50, 52 of wear indicator 16 are free to laterally translate within slot 18, and since the forces the opposing end covers apply are parallel to the thickness of the wear indicator, the wear indicator oscillates like a free beam.
To illustrate the manner in which the indicator oscillates as a free beam, FIGS. 5A-C have been provided. These figures illustrate a top view of slot 18 in which indicator 16 is disposed. Each figure illustrates two extreme positions of indicator 16 as it oscillates side to side in slot 18. One such position is shown as a solid outline of indicator 16 and the other is shown as a dashed outline of indicator 16 that is superimposed on the solid outline. The width of slot 18 and the magnitude of the oscillation are enlarged to more clearly indicate the different vibratory modes. These figures show the primary modes of oscillation of indicator 16 within slot 18 schematically in several oscillating modes. The ends of the indicator are not constrained and so it can be modeled as a vibrating beam having both ends free. A beam with two free ends, such as the indicator, has nodes 54, 56, 58, 60, 62, 64, 66, 68 and 70, where lateral vibration of indicator 16 (i.e., vibration side to side in slot 18) approaches zero, and maxima 72, 74, 76, 78, 80 and 82, where the lateral vibration of indicator 16 has its greatest magnitude. FIGS. 5A-C differ from each other in the number of nodes and maxima and in the frequency of oscillation. Specifically, FIGS. 5A-C illustrate the first, second and third modes of harmonic oscillation of a free beam, respectively. The Applicants consider these to be the dominant modes of harmonic oscillation for a typical indicator.
If the indicator vibrates in any of these modes of oscillation, and if step 40 or transitional portion 44 is disposed at one of these maxima, the step or transition portion in intimate contact with step 42 or portion 46 will experience significant wear. Conversely, locating step 40 or transition portion 44 at a node will minimize this wear. For this reason, the transition portion should be disposed at a local node in the preferred embodiment.
The position of a node depends upon the indicator's mode of oscillation as can be seen by comparing FIGS. 5A, 5B and 5C. FIG. 5A schematically illustrates the indicator in its first harmonic mode of oscillation. This is the most simple mode of harmonic oscillation, with nodes 54 and 56 located approximately 22% and 78% of the distance along the length of the indicator. In the second harmonic mode shown in FIG. 5B, nodes 58, 60 and 62 are respectively located approximately 13%, 50% and 87% of the total distance along the length of the indicator. In the third harmonic mode shown in FIG. 5C, nodes 64, 66, 68 and 70 are respectively located approximately 9%, 36%, 64% and 92% of the total distance along the length of the indicator. To minimize wear between transition portion 44 of the indicator and portion 46 of the bottom of slot 18 with which it is engaged, portions 44 and 46 should be located at these nodal positions. Thus, step 40 and transition portion 44 of indicator 16 should be located on the slot edge at a position either 9%, 13%, 22%, 36%, 50%, 64% 87% or 92% from one longitudinal end of the indicator depending upon the dominant node.
In FIG. 4, the transition portion clearly extends over a portion of the length of indicator 16, unlike the embodiment shown in FIG. 3. Since the entire length of the transition portion in FIG. 4 cannot be located entirely at a node, there will be some vibration and wear. By locating at least a portion of transitional portion 44 at a node, however, the amount of wear will be reduced significantly.
The indicator provides a reliable indication of vane wear in the compressor only if it is worn away in a manner proportionate to the wear of the other vanes in the compressor during operation. For this reason, the indicator is preferably made of the same or similar material as the vanes and preferably has the same or a substantially similar coefficient of wear as the other vanes in the compressor. For example, the wear indicator may be a composite such as a resin impregnated asbestos cloth (fiber-reinforced resins) or may be made of nonreinforced engineering plastics such as PAI, PEEK and PPS. Locating the step or transitional portion thereof at the nodal positions identified above is of particular value when using nonreinforced plastics, since they are extremely flexible when compared to fiber-reinforced plastics, and thus have a much higher amplitude of oscillation given the same inputs.
FIGS. 6-8 illustrate the manner in which the wear indicator is used to indicate wear. FIG. 6 shows an end view of a compressor 80 with a cover removed from the end facing the viewer. Rotor 82 has a slot 84 in which wear indicator 86 is disposed. In this embodiment wear indicator 86 is disposed angularly equidistant from the other vanes of the compressor. Rotor 82 is shown rotationally oriented so that slot 84 is near the bottom of rotor 82. Indicator 86 rests against the bottom inner surface 88 of compressor housing 90. In the lowermost position of slot 84, a slight gap or "bottom clearance" is provided between outer cylindrical surface 92 of rotor 82 and inner surface 88 of housing 90. Rotor shaft 94 extends outwardly from rotor 82. In other compressors of this type, the rotor is offset toward the top, rather than the bottom of the compressor housing, and thus the clearance would be "top clearance."
FIG. 7 is a partial cross-sectional view of the FIG. 6 embodiment at Section 7--7, showing the position of indicator 86 and its step 96 with respect to rotor 82. Rotor 82 has a shaft 98 extending from one end that is supported by bearing 100 mounted in cover 102. Seal ring 104 is mounted on shaft 98 and prevents gas from leaking out of the compressor. Cap 106 seals the end of cover 102. In this view, it can be seen that indicator 86 cannot be withdrawn from slot 84 since step 108 on rotor 82 engages step 96 on indicator 86.
FIG. 8 illustrates the FIGS. 6-7 compressor after indicator 86 has worn significantly. Due to its wear, the overall width W of indicator 86 is reduced. This smaller width allows the indicator to drop clear of step 108. In this position a repairman can easily slide it out of its slot. The indicator is worn enough to be replaced if it can be removed as described above.
Clearly, a new indicator cannot simply be inserted in the slot 84 since the greater width of a new wear indicator such as that shown in FIG. 7 will interfere with step 108 and prevent the wear indicator from being inserted into slot 84. To surmount this problem, rotor 82 is simply rotated until slot 84 is spaced away from the inner surface 88 of compressor housing 90, such as the uppermost position 110 shown in FIG. 6. When rotor 82 is rotated to move slot 84 into position 110, a sufficient space between the step 108 of rotor 82 and the inner surface 88 of housing 90 will allow the indicator to be inserted into slot 84.
When a single vane is worn enough to need replacing, typically all the vanes are replaced. For this reason, if the wear indicator indicates that a vane needs replacing, typically all the vanes are replaced, since all the vanes will have substantially the same amount of wear. Replacing the vanes in the embodiment of FIGS. 6-8 is a simple process. Since the other vanes in compressor 80 are typically not provided with the stepped construction of indicator 86 and slot 84, the other vanes are easily removed simply by pulling them out of their respective slots. In other compressor applications, it may be more cost effective to replace each vane as it is worn rather than using a single wear indicator as a signal to replace all of the vanes. In such a compressor all of the slots in rotor 82 would be provided with the stepped structure of slot 84. In this manner, an indicator could be substituted for every standard vane in the compressor, and each indicator can be individually tested and replaced as necessary. Although compressor 80 is illustrated having an abrupt step, a transitional step such as that shown in FIG. 4 could be substituted. In addition, the relative widths W, X of indicator 86 are preferably the same as described for indicator 16 and the longitudinal position of step 96 is preferably the same as that of indicator 16.
Thus, it should be apparent that there has been provided in accordance with the present invention a vane wear indicator that fully satisfies the objectives and advantages set forth above. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. | The invention includes a wear indicator for a radially extensible vane compressor. The indicator is an elongate member having two longitudinal sections with a step inbetween. The step catches on a mating step formed in the compressor rotor when it is good and does not catch on the mating step when it is bad (i.e., worn). A repair person can test the wear of the indicator merely by attempting to withdraw the indicator. If it is removed it is worn, and if it is not removable, it is acceptable. | 5 |
This is a divisional of copending application(s) Ser. No. 07/914,194 filed on Jul. 9, 1992 now U.S. Pat. No. 5,326,108.
BACKGROUND OF THE INVENTION
Various arcade-style games have been known and used in the past. These types of games generally dispense tickets or tokens to a winning player. The player redeems the tickets for a prize at a redemption center at another location within the arcade. Winning tickets or tokens are ordinarily dispensed in proportion to the player's game score or how well the player did. At the redemption center, prizes and merchandise are displayed. By trading in tickets or tokens, the winning player can receive a prize from the operator of the redemption center.
The redemption center requires a substantial amount of space. An attendant is also necessary at the redemption center to count tickets for tokens tendered by winning players in exchange for prizes. Accordingly, redemption centers have not been practical or cost effective at locations having only few machines and players.
As far as is known, all redemption centers have in the past also operated on the principal that arcade games and other skill games are played for fun and amusement, with tickets or tokens dispensed to winners, redeemable for a prize, but not for any specific prize. Accordingly, while playing an arcade game, the player is not attracted or motivated to win any specific prize.
SUMMARY OF THE INVENTION
The present invention is directed to a game unit having a skill game and an automated redemption center linked to the skill game. To this end, a skill game and redemption center are housed in a cabinet. A game controller counts the player's score, indicates prizes available to the player for the score achieved, allows the player to redeem points for prizes during or after the game, and adjusts the player's score for any prizes taken by the player.
Accordingly, it is an object of the present invention to provide an improved game unit.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed description taken in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed for the purpose of illustration only and are not intended as a definition of the limits of the invention.
In the drawings, wherein similar reference characters denote similar elements throughout the several views:
FIG. 1 is a front elevation view showing the front door of the present game unit;
FIG. 2 is a front elevation view of the present game unit with the front door swung open or removed;
FIG. 3 is a side elevation view of the present game unit;
FIG. 4 is a plan view of the wheel unit shown in FIGS. 2 and 3;
FIG. 5 is a side elevation view fragment taken along line 5--5 of FIG. 4;
FIG. 6 is an exploded perspective view of the dispenser back panel and a dispenser tray;
FIG. 7 is a side section view of the coin toss gun shown in FIGS. 1 and 3;
FIG. 8 is a bottom section view thereof;
FIG. 9 is an end view thereof taken along line 9--9 of FIG. 7.
FIG. 10 is a top elevation view of the coin toss gun;
FIG. 11 is a schematic illustration of the electronic game controller;
FIG. 12 is a flow chart illustrating a mode of operation effected by the game controller;
FIG. 13 is a flow chart illustrating a second mode of operation effected by the game controller;
FIG. 14 is a flow chart illustrating a third mode of operation effected by the game controller;
FIG. 15 is a top view of an alternative design having a straight wiper;
FIG. 16 is a front view thereof;
FIGS. 17 and 18 are top views illustrating the operation of the wheel unit of FIG. 4;
FIG. 19 is a side view in part section of an adjustable coin sensor; and
FIGS. 20 and 21 are schematic illustrations of a coin box sensor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawings, as shown in FIG. 1, the present game unit 20 includes a cabinet 22 having extruded aluminum edge frames 24. On the front 26 of the game unit shown, a clear panel 28 preferably of tempered glass, extends from approximately the mid-point to adjacent the top of the cabinet 22. Below the clear panel 28 is a gun panel 30. A gun plate 34 on the gun panel 30 has a dual access swivel mount 36 extending through the gun plate 34. A coin toss gun 32 is mounted in the dual access swivel mount 36. A cabinet lock 38 is provided at one side of the gun panel 30.
A bulk dispensing unit 40 is positioned within the cabinet 22 below the gun panel 30. The bulk dispensing unit 40 holds bulk prizes, e.g., gumballs, jawbreakers, etc. Bulk prize display windows 44 allow the game player to view the bulk prizes. Bulk select buttons 42 at the top of the bulk dispensing unit 40 are pressed to select a bulk prize which is released into a tray 46 from which bulk prizes can be picked up by the player.
The extruded edges 24, clear panel 28, gun panel 30 and bulk dispensing unit are part of the front door 58 of the cabinet 22. The door 58 is hinged to the cabinet 22 and can be unlocked and swung open. A key pad 48 and a retrieval door 52 are also provided on the door 58. Electrical cables running from the bulk dispensing unit 40, select buttons 42 and key pad 48 extend from the door 58 back into the cabinet 22 and connect to a game controller 240.
FIG. 2 illustrates the game unit 20 without the door 58 shown. As shown in FIG. 2, the cabinet 22 includes a skill game 60 on one side and a prize dispenser 62 on the other side of the cabinet. A divider 64, preferably made of tempered glass, separates the skill game cabinet space 92 from the prize dispenser cabinet space 94. Overhead cabinet lights 66 are provided over the skill game 60 and prize dispenser 62. A back cover panel 68, preferably a reflective grid, is provided behind the skill game 60 within the cabinet 22. Neon lights 56 in artistic or geometric shapes are provided within the cabinet 22 behind the skill game 60, and are preferably also located within the door 58.
The skill game 60 includes one or more bowls which serve as targets for scoring game points. In the embodiment shown, a first bowel 70 is positioned adjacent the top of the cabinet 22, with a second bowl 74, a third bowel 76 and a fourth positioned consecutively below the first bowl 70. The bowls increase progressively in size or diameter from the first bowl 70 down through the fourth bowl 76. Each bowl has a points flag 80 mounted on a bowl rim 78. The points flag 80 indicates the number of points awarded for shooting or tossing a coin into that bowl. A bowl support 88 is attached to a pivot ring 90 on each of the bowls. The supports 88 may be attached to the bottom, sides or top of the cabinet 22, to support each bowl. A coin chute 84 protrudes at an angle from the bottom of each bowl. The coin chute preferably has a flattened rectangular cross section to capture the coin, stand it on edge, direct it through a narrow slot and better control movement of the coin. A coin detector 86 is provided in each chute 84 to detect passage of a coin. The pivot ring 90 allows each bowl to be turned to any specific angular orientation of the chute 84. Coin slides or deflectors can be attached to the chutes. In the embodiment shown in FIG. 2, the bowls are arranged so that a coin tossed into any bowl will be guided into all subsequent lower bowls, thereby consecutively adding to game points earned for that coin. Bowl size preferably range from 1 to 16 inch diameter.
As shown in FIGS. 2-5, a wheel unit 100 is positioned within the cabinet 22 below the lower most bowl 76. The wheel unit 100 has a fixed base 102 and an angled or tapered target hole surface 104. Target holes 106 are equally spaced around the diameter of the target hole surface 104. Outer posts 108 and inner posts 110 may be provided radially aligned with the target holes, as best shown in FIG. 4. The posts, if used, can be positioned to guide a coin into the target holes. The top surface of the wheel unit 100 is flat and covered with a felt pad 118. A wiper 114 is mounted on a wiper shaft 116 which is slowly turned or alternated by a motor within the base 102. As shown in FIG. 5, a coin detector 86 is associated with each target hole 106 in the wheel unit 100. Alternatively a straight alternating wiper 250 design, as shown in FIGS. 15 and 16 can be used.
Below the wheel unit 100 is a coin grate 128 having openings large enough to allow coins to pass from the skill game cabinet space 92 through the grate 128 and into a slide 130. A coin box 132 is positioned adjacent to the bottom of the skill game cabinet space 92 and is connected to the slide 130 to collect and store coins which fall down from the skill game cabinet space 92.
A point display 126 supported within the skill game cabinet space 92 displays the player's points. The display 126 is linked to the game controller 240 in the cabinet 22 through a wiring harness. The display 126 may optionally be used to convey messages to the player.
Referring to FIGS. 2 and 6, on the side of the partition 64 opposite to the skill game cabinet space 92 is a prize dispenser cabinet space 134, also within the cabinet 22. Alternatively, a separate dispenser cabinet can be joined to a game cabinet. Dispenser trays 136 are positioned within the dispenser cabinet space. Prizes are carried in the dispenser trays 136. A spiral pusher 138 holds and dispenses prizes 140, when actuated by a motor at the rear of the spiral pusher 138. Hanging prize dispensers 142 operate in a similar manner and hold and dispense hanging prizes. A prize light 144 at the front of each dispenser tray 136 and hanging prize dispenser 142 illuminates when sufficient points have been accumulated to award the prize held by that dispenser tray or hanging prize dispenser.
As shown in FIG. 6, a back panel 146 is attached to the cabinet 22 behind the dispenser trays 136 and hanging prize dispensers 142. Hooks 154 on the dispenser trays 136 and hanging prize dispensers 142 engage slots 152 in the back panel 146. A wiring harness 148 leading to the prize light 144 and dispenser drive motor (not shown) terminates in a connector 150. The connector 150 connects to a wiring harness joined to the game controller 240. The dispenser trays 136 and hanging prize dispensers 142 are set back sufficiently from the clear panel 28 of the door 58 to allow dispensed prizes to fall into a drop box behind the retrieval door 52.
As shown in FIGS. 7-10, a coin toss gun 160 has a chassis 162 having a launch end 228 and a loading end 230. A handle 164 extends generally perpendicularly downwardly from the chassis 162 at the loading end 230. A dual access swivel mount 36 is attached around the chassis 162. The swivel mount 36 has a turret 168 mounted within a turret support 158. The turret 168 and support 158 have complimentary spherical surfaces to allow the gun 160, when installed in the cabinet 22, to swivel in two directions, i.e., vertically and horizontally. The support 158 has flanges 166 for mounting the gun 160 to the cabinet 22, i.e., to mount the gun 160 to the gun plate 34 on the gun panel 30, as shown in FIG. 1 and 3.
Weights 161 are attached to the launch end of the gun (i.e., the end positioned inside of the cabinet). The gun is balanced so that in the standby position, the launch end points downwardly and gravity will cause a coin inserted into the gun to slide downwardly and into the launch position.
Referring to FIGS. 7 and 10, the chassis 162 has a coin track 170 extending from a top loading hole 220 at the loading end 230, to a hammer hole 222 at a launch position 180 at the launch end 228. The coin track 170 is covered by a cover plate, or can be formed by an appropriately shaped extrusion. A loading slot 178 may be provided at the back surface of the gun 160 above the handle 164, as an alternate coin loading position instead of the top loading hole 220. As shown in FIG. 8, a discharge slot 176 is provided through the chassis 162 beneath a section of the coin track 170, to allow debris or improperly sized coins to fall out of the gun 160. To avoid awarding points for slugs, foreign coins, etc., a coin counting and measuring device, at the end play, verifies that a proper coin has been shot before any points are awarded. The gun is designed to operate with different types of coins or tokens. A coin detector, preferably an electronic sensor detects the presence of a coin and begins game play.
As shown in FIGS. 7 and 8, a hammer 182 is pivotally mounted on a hammer pivot shaft 192. The hammer has a hammer face 194, a claw 172 and an eccentric boss 190. A hammer spring 196 engages the hammer 182 and a pin or protrusion in the chassis 162. The hammer spring 196 biases the hammer 182 in an upward or clockwise (as shown in FIG. 7) direction.
A ratchet twice pawl 198 is pivotally mounted on a rachet pivot pin 204. A ratchet twice spring 202 engages the rachet pawl 198 and a pin or protrusion in the chassis 162, and biases the ratchet pawl 198 against the claw 172 of the hammer 182. The claw 172 has a ratchet surface 200, to securely engage the ratchet pawl 198.
Towards the loading end 230 of the gun 160 are pull back lever arms 184, pivotally mounted on either side of the chassis 162 on a lever arm pivot shaft 212. A return spring 214 biases the lever arm pivot shaft 212 counterclockwise (as shown in FIG. 7) urging thumb or finger surfaces 232 on the pull back lever arms 184 upwardly. A pull back rod 186 is pivotally attached to an armature 234 extending from the lever arm pivot shaft 212, at the loading end 230, to a rod end 188 on the boss 190 of the hammer 182, at the launch end 228 of the chassis 162.
A trigger 208 is pivotally mounted on a trigger pivot pin 210 in the chassis 162. A trigger rod 206 is pivotally attached to the trigger 208 and extends through the chassis 162 to an eccentric extension 236 on the ratchet pawl 198. In an alternative gun design, the gun has a spring linked to a rod connecting the lever arm and the hammer. With this design, the lever arm is simply drawn back for appropriate tensioning and then immediately released.
A coin stop 218 is provided on the chassis 162 at the launch end 228 to appropriately position a coin over the hammer hole 222. A detector hole 224 is positioned adjacent to the hammer hole 222, with a coin detector 226 below or within the detector hole 224.
The bulk select buttons 42, key pad 48, coin detector 86, display 126, prize lights 144 and coin detector 226, as well as lights and other components, are wired to a game controller 240 (FIG. 11) within the cabinet 22. The game controller includes counters, logic and switching components for operation of the game unit 20.
As shown in FIG. 19, the height of a sensor can be adjusted so that a quarter (large diameter) will be detected, but a nickel (small diameter) will not. This adjustment can also be made to differentiate between nickels and pennies, etc.
Referring to FIG. 20 and 21, four sensors of different heights allow a coin to pass into the cash box while detecting the size (and thus value) of the coin. The tallest sensor detects quarters only. The next tallest detects quarters and nickels. The third tallest detects quarters, nickels and pennies. The smallest detects quarters, nickels, pennies, and dimes. The game uses these sensor signals to determine what type of coin has been played.
In operation, the game operator (i.e., the owner or maintainer of the game unit) sets various game parameters (e.g., points scored for various events) by programming the game controller 240 and adjusting the position and/or orientation of the bowls. The gun tensioning range and turret swivel range can be adjusted by the game operator. The operator loads bulk prizes into the bulk dispensing unit 40 and prizes 140 onto the dispenser trays 136 and hanging prize dispensers 142. The game unit 20 can advantageously be located in convenience stores, video stores, and in other locations where space is limited and a redemption center is not practical or possible. The game unit 20 occupies only approximately 20 square feet of floor space. Since the prize dispenser 62 effectively replaces and surpasses the functions of a redemption center, the game unit 20 can be successfully operated in lower volume and lower traffic locations. The game controller 240 controls all functions of the game unit 20, such that an attendant is no longer required to exchange tickets or tokens for prizes.
The game controller 240 initially places the game unit 20 into an attract mode. The attract mode may include switching cabinet lighting on and off, sequencing the marquee lights 54 and optionally includes audio components, to attract players.
A player places a coin 120 into the loading slot 178 or a top loading hole 220 of the coin toss gun 160. The gun 160 is then tilted or swiveled so that the coin slides down the coin track 170 of the chassis 162 of the gun 160. The coin comes to rest against the coin stop 218 at the launch end 228 of the gun 160. The coin is then resting in the coin track 170 over the hammer hole 222. The coin detector 226 detects the presence of the coin and the game controller 240 further prepares the skill game 60 for operation by e.g., causing the wiper 114 to turn, generating sound effects, illuminating messages for the player on the display 126, illuminating "theme lights" etc.
The player presses on the finger surface 232 of the pull back lever arms 184, to set the tension or tossing force of the player's shot. While holding the handle 164, the player aims or positions the gun. An add on scale or pointer 165 can be provided so the player can measure the tension applied in pushing on the lever arms. The handle 164 and loading end 230 of the gun 160 are mounted on the outside of the cabinet 22, while the launch end 228 and hammer hole 222 are inside of the cabinet 22. The dual access swivel joint 36 allows the player to position the launch end 228, in two dimensions, by manipulating or positioning the handle 164.
As the pull back 1ever arms 184 are pressed down by the player, the pull back rod 186 pulls on the boss 190 causing the hammer 182 to pivot downwardly (or counterclockwise in FIG. 7). The further the pull back lever arms 184 are pressed down by the player, the further the hammer 182 will be drawn back against the biasing force of the hammer spring 196. The ratchet pawl 198 continuously engages the ratchet surface 200 to prevent the hammer 182 from prematurely releasing. With the gun 160 properly aimed, the player squeezes the trigger 208. The trigger 208 pulls back on the trigger rod 206 causing the rachet pawl 198 to rotate and release the rachet surface 200 of the hammer 182. The hammer 182 rapidly swings or pivots upwardly (clockwise in FIG. 7), driven by the force of the hammer spring 196. The hammer face 194 passes through the hammer hole 222 and strikes the coin. The coin is tossed or shot up and out perpendicularly to the gun chassis 162.
The return spring 214 returns the pull back lever arms 184 to the rest position to avoid snap back when the hammer is triggered. The ratchet spring 202 returns the rachet pawl 198 to its rest position. Similarly, the trigger spring 216 returns the trigger 208 to its original position, such that the gun 160 is reset for another coin toss.
The hammer face 194 is positioned relative to the hammer hole 222 so that it strikes the coin in an off-center position, causing the coin to fly up from the gun 160 with a flipping motion, i.e., the coin flies in a trajectory while rotating end over end. The dual access swivel mount 36 allows the player to adjust the tossing direction towards any position within the cabinet 22. The pull back lever arms 184 and hammer-ratchet pawl mechanism allows the coin to be tossed using various tensions, to adjust the height or speed of the toss. The player can then reach various heights and depths inside the cabinet 22.
A skilled player who has properly aimed and tensioned the gun 160 to achieve maximum points can shoot the coin into the first bowl 70. The coin will then enter and slide through the chute 84 of the first bowl 70. The coin detector 86 in the first bowel 70 will detect coin and the game controller 240 will count and/or record the number of points awarded for the first bowl 70. The game controller 240 will also generate sound effects as points are scored. The coin will then automatically similarly pass through the second bowl 72, third bowl 74 and fourth bowl 76, with additional points recorded for each of these bowls.
The coin then passes out of the chute 84 of the fourth bowl 76 and drops onto a specific predetermined drop location in the pad 118 of the wheel unit 100. The slowly turning or alternating wiper 114 moves around and contacts and pushes the coin 120 in a geometric path 122 leading to a target hole 106 in the wheel unit 100 as shown in FIGS. 4 and 5. As the wiper pushes the coin, the coin will consistently roll on the pad 118 in the geometric path from the drop location to the target hole. Of course, if a coin lands on the pad away from a drop location, the coin will be pushed off by the wiper in between target holes and will fall off the wheel unit 100 without scoring additional points. The chute 84 on the fourth bowl 76 is positioned sufficiently close to the pad 118 to be able to consistently drop or place the coin onto a drop location.
Referring to FIG. 17, the leading edge `A` of the wiper 114 has a curvature that causes coin `B` to move rapidly toward the outside edge of table surface 112. The coin rolls along leading edge `A` while proceeding in a linear path `C` toward a target hole `D`. Given the starting point marked by coin `B`, path `C` is precise and repeatable. Significantly, if leading edge `A` were not curved, but instead were straight (the wiper then resembling a straight diameter) the coin motion would differ. Instead of following 11near path `C`, the coin would follow a long, outwardly spirally path with an unpredictable end point. By using the curved leading edge `A`, the coin's end point is predictable.
As shown in FIG. 18, the wiper can be made to have short ends `E` that allow coins `G` to accumulate around the rim of the table. An additional coin `F` is then required to push coins `G` into one or more target holes. Coins `G` act as an incentive to attract more players to the game. An alternative disk or platter has a beveled rim around the edge to allow coins to build up around the outer edge and hang off, about to fall.
As the coin 120 is pushed from a drop location off of the pad 118 by the wiper 114, the coin falls into a target hole 106, is detected by the coin detector 86 and additional points are recorded. A hard material may be substituted for, or placed on the opposite side of the felt pad 118 which can be flipped over. However, such a hard material will cause the coin 120 to bounce and fall off of the table surface 112 or land off of a drop location, in a position on the table surface not lying on a geometric path 122 leading to a target hole 106. Similarly, coin tosses which miss any of the bowls and land on the table surface 112, may or may not be swept by the wiper 114 into a target hole 106 for additional points, depending on whether the coin 120 comes to rest at any of the drop locations on a geometric path 122 leading to a target hole. Coins which miss any of the bowls or wheel unit 100, because of improper aiming or tensioning of the gun 160, fall through the grate 128 and are collected in the coin box 132. Coins passing through the target holes 106 similarly fall through the base 102 of the wheel unit 100 into the coin box 132. A grate coin detector can be provided to detect coins passing only through the gate, so that a consolation prize or points can be awarded.
The prizes in the prize dispenser 62 are in front of the player while the skill game 60 is being played. Accordingly, the player can play with the intent of winning specific prizes, and not simply for entertainment, with tickets or tokens only incidentally dispensed by the machine as previously known. Having the prizes before the player, at all times, attracts and motivates the player to play the skill game 60 for a specific prize in the prize dispenser 62.
The bulk unit stores large amounts of lower value prizes. This allows prizes to be awarded for minimum scores without requiring constant reloading of prizes.
As the player accumulates points, the game controller 240 switches the prize lights 144 on, when the number of points required to receive the prize associated with a specific prize light 144 is reached by the player. The prize lights enable children and/or visually impaired persons to see which prizes are available to them. During or after the game, the player may redeem points for prizes using the key pad 48. By punching into the key pad the number or letter combination associated with a specific prize on the dispensers trays 136 or hanging the prize dispensers 142, the prize desired by the player is dispensed and falls to the drop box 50 where it can be retrieved through the retrieval door 52.
Specifically, the game controller 240 interprets the switch combination from the key pad 48 and actuates or switches on the spiral pusher motor for the dispenser tray 136 or hanging prize dispenser 142 associated with the letter or number combination received from the key pad 48. The game controller 240 also debits or subtracts from the player's accumulated points the number of points redeemed for the prize received. Accordingly, during or after the game, a player having earned a certain number of points may elect to receive a single prize having a high point value, or several prizes of lower point values.
The game controller has the capability to record data on the number of coins played and the number and value of prizes dispensed, to calculate a "points per coin" average. This average can be used by the operator to determine how much buying power the average player has per coin. The operator can then adjust the point value of each prize to prevent a prize from being too difficult or too easy to win.
Although the drawings show a game unit 20 having a single cabinet 22 holding the skill game 60 and prize dispenser 62, in an alternate embodiment, the skill game 60 and prize dispenser 62 may be contained in separate cabinets which may be attached together in a modular system. In addition, various numbers of bowls or other targets may be provided within the game unit in varying arrangements. Bowls or targets may also be attached to the wiper shaft 116 or otherwise made to revolve or move about within the cabinet 22 in a pattern or timed sequence. In this embodiment, the player must time his shots to account for movement of the targets. Similarly, in an embodiment having motor driven continuously revolving bowls, the player must time his shots to coincide with a desired orientation of the chute of the turning bowl.
Thus, a novel game unit is disclosed and described. While embodiments and applications of this invention have been disclosed and illustrated, it would be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims. | A game unit having a skill game combined with a prize dispenser. A coin toss gun shoots or tosses coins at targets in the skill game. A wheel unit has a flat top surface. A wiper wipes coins landing on the top surface in geometric paths which may lead to target holes spaced about the circumference of the wheel unit. The coin toss gun has a pull back lever arm for presetting the height of the coin toss. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefits of the Taiwan Patent Application Serial Number 099130861, filed on Sep. 13, 2010, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a dengue vaccine, a pharmaceutical composition comprising the same and a nucleotide sequence, more particularly, to a dengue vaccine with reduced cross-reactivity with endothelial cells and platelets, a pharmaceutical composition comprising the same, and a nucleotide sequence.
[0004] 2. Description of Related Art
[0005] Dengue fever, also called breakbone fever, is an acute infectious disease induced by the propagation of dengue viruses (DV) via Aedes aegypti or Aedes albopictus and its symptoms include high fever (39° C. to 40° C.) or aversion to cold, skin rash, fatigue in limbs, muscle pain, frontal headache, retro-orbital pain, abdominal pain, backache (hence the term breakbone fever), sore throat, and maybe vomiting and fainting. The commonly mentioned dengue virus is classic dengue fever, also called primary dengue fever. In addition, severe and life-threatening dengue fever characterized by hemorrhage or shock may be developed, also called dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), or secondary dengue.
[0006] It is estimated that there are about 50 million to 100 million cases of dengue infection worldwide each year, with about 250,000 to 500,000 cases of dengue hemorrhagic fever. In other words, two-fifths of the world's population is at risk from dengue infection. Hence, the prevention and treatment of dengue fever is an important issue for the governments of many countries. However, the mechanism underlying dengue disease is not clearly understood. Furthermore, neither effective and safe vaccines nor drugs on specific treatment of diseases caused by dengue viruses are available so far. Since dengue virus is the major pathogen of dengue disease, the early detection or prevention with effective vaccine can efficiently control morbidity and death rates of dengue fever.
[0007] Recently, numerous strategies of dengue vaccine design are based on the neutralizing efficacy of antibodies against viral envelope (E) or nonstructure (NS) protein. Although the E protein is responsible for eliciting major neutralizing antibodies during DV infection, it is also associated with the induction of antibody dependent enhancement (ADE). Antibody dependent enhancement (ADE) is a complicating factor in dengue vaccine development in that the pre-existing antibodies raise concerns of causing more severe disease. In contrast, antibodies against the NS1 protein are able to kill DV-infected cells by complement-induced cell lysis and thus are not associated with ADE. A limitation to the vaccine strategy of NS1, however, is that anti-NS1 antibodies may cause cross-reaction with endothelial cells and platelets, and thus may negatively influence coagulation function, resulting in prolonged bleeding time. The side effect of autoimmunity caused by the vaccine still has not been resolved.
[0008] Therefore, it is desirable for the technical field to develop a novel vaccine which does not induce antibody dependent enhancement and autoimmunity, is depleted of cross-reactivity with endothelial cells and platelets, and is able to shorten bleeding time.
SUMMARY OF THE INVENTION
[0009] The dengue vaccine according to the present invention includes C and N termini-deleted nonstructural protein ΔNC NS1 with a peptide fragment from amino acids 36 to 270, which is derived from dengue virus nonstructural protein 1 (DV NS1) with deletions of N-terminal region from amino acids 1 to 35 and C-terminal region from amino acids 271 to 352.
[0010] Through sequence alignment analysis, the inventors of the present invention found that the N-terminal and C-terminal regions of DV NS1 protein contain epitopes involved in cross-reactivity to target proteins. Therefore, the inventors of the present invention used N terminus (aa 1-35)-deleted and C terminus (aa 271-352)-deleted DV ΔNC NS1 protein as a vaccine to reduce the cross-reactivity with endothelial cells and platelets and thus to shorten bleeding time. In addition, DV ΔNC NS1 protein of the present invention is derived from dengue virus nonstructural protein rather than dengue virus envelope protein, and thus can be used as an inventive and practical vaccine without antibody dependent enhancement and autoimmunity.
[0011] In the dengue vaccine of the present invention, the N and C termini-deleted nonstructural protein ΔNC NS1 preferably has the amino acid sequence of SEQ. ID. NO. 1.
[0012] In the dengue vaccine of the present invention, the N and C termini-deleted nonstructural protein ΔNC NS1 preferably is derived from dengue virus protein. The dengue virus protein is, for example, SEQ. ID. NO. 3 in the sequence listing.
[0013] In the dengue vaccine of the present invention, the dengue vaccine preferably is used to prevent dengue hemorrhagic fever or dengue shock syndrome.
[0014] In the dengue vaccine according to the present invention, the amino acid sequence similarity between the N and C termini-deleted nonstructural protein ΔNC NS1 and the SEQ. ID. NO. 1 preferably is 90% or more, and more preferably is 95% or more.
[0015] The present invention further provides a dengue vaccine-containing pharmaceutical composition. The dengue vaccine includes N and C termini-deleted nonstructural protein ΔNC NS1 with a peptide fragment from amino acids 36 to 270, which is derived from dengue virus nonstructural protein 1 (DV NS1) with deletions of N-terminal region from amino acids 1 to 35 and C-terminal region from amino acids 271 to 352.
[0016] The dengue vaccine-containing pharmaceutical composition according to the present invention includes N terminus (aa 1-35)-deleted and C terminus (aa 271-352)-deleted DV ΔNC NS1 protein, which is depleted of cross-reactivity with endothelial cells and platelets, is able to shorten bleeding time and does not cause antibody dependent enhancement and autoimmunity.
[0017] In the dengue vaccine-containing pharmaceutical composition according to the present invention, the N and C termini-deleted nonstructural protein ΔNC NS1 preferably has the amino acid sequence of SEQ. ID. NO. 1.
[0018] The dengue vaccine-containing pharmaceutical composition according to the present invention preferably is used to treat or prevent dengue hemorrhagic fever or dengue shock syndrome.
[0019] In the dengue vaccine-containing pharmaceutical composition according to the present invention, the amino acid sequence similarity between the N and C termini-deleted nonstructural protein ΔNC NS1 and the SEQ. ID. NO. 1 preferably is 90% or more, and more preferably is 95% or more.
[0020] The present invention also provides a nucleotide sequence that encodes N and C termini-deleted nonstructural protein ΔNC NS1. Herein, the N and C termini-deleted nonstructural protein ΔNC NS1 contains DV NS1 from amino acids 36 to 270.
[0021] The N and C termini-deleted nonstructural protein ΔNC NS1 encoded from the nucleotide sequence of the present invention is able to act as a dengue vaccine and shorten bleeding time, depleted of cross-reactivity with endothelial cells and platelets, and does not cause antibody dependent enhancement and autoimmunity.
[0022] The nucleotide sequence of the present invention preferably is SEQ. ID. NO. 2 in the sequence listing. Preferably, SEQ. ID. NO. 2 is obtained from the nucleotide sequence of dengue virus, which is shown as SEQ. ID. NO. 4 in the sequence listing.
[0023] The nucleotide sequence of the present invention preferably is used to produce a dengue vaccine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 shows the results of antibody binding to platelet assay in vitro according to one preferred example of the present invention;
[0025] FIG. 2 shows the results of antibody binding to platelet assay on passively immunized mice according to one preferred example of the present invention;
[0026] FIG. 3 shows the results of bleeding time tests on actively immunized mice according to one preferred example of the present invention; and
[0027] FIG. 4 shows the results of antibody binding to endothelial cell assay in vitro according to one preferred example of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Mice
[0028] C3H/HeN mice were obtained from The Jackson Laboratory and maintained on standard laboratory food and water in the Laboratory Animal Center of National Cheng Kung University Medical College. Their 8-wk-old progeny were used for the experiments. Housing, breeding, and experimental use of the animals were performed in strict accordance with the Experimental Animal Committee in National Cheng Kung University.
[Platelet Preparation]
[0029] Human whole blood containing anticoagulant (29.9 mM sodium citrate, 113.8 mM glucose, 72.6 mM NaCl, and 2.9 mM citric acid (pH 6.4)) was centrifuged at 100×g for 20 min at room temperature to obtain platelet-rich plasma (PRP). The platelet-rich plasma was centrifuged at 1000×g for 10 min at room temperature and washed in EDTA/PBS buffer twice. The washed platelets were suspended in Tyrode's solution (137 mM NaCl, 20 mM HEPES, 3.3 mM NaH 2 PO 4 , 2.4 mM KCl, 1 mg/ml BSA, and 5.6 mM glucose (pH 7.4)) at a concentration of 10 8 platelets/ml.
[0000] [cDNA]
[0030] Dengue type 2 (New Guinea C strain) virus grown in BHK21 cells was available from National Institute of Preventive Medicine, Department of Health, and cDNA were obtained. Escherichia coli BL-21 (DE3) pLysS strain bearing the plasmid pRSET-DVNS1 was used to express recombinant proteins of DV NS1 and was available from Shiau's lab (Dr. Ai-Li Shiau) of Department of Microbiology and Immunology of National Cheng Kang University (Taiwan).
[0000] [DV ΔNC NS1 from cDNA]
[0031] Primers P3758, P3759, P3760 and P3761 were used to amplify DV ΔNC NS1 cDNA from the pPRSET-DVNS1. Herein, PCR was performed as follows.
[0000]
Primer
P3758: 5′-AATTCCCAGAATCCCCTTCAAAACTG-3′;
P3759: 5′-CCCAGAATCCCCTTCAAAACTG-3;
P3760: 5′-TCGAGTCATAAATGCCATGGTCC-3′;
P3761: 5′-GTCATAAATGCCATGGTCCTGCTAT-3′.
[0032] PCR primers, pPRSET-DVNS1 as a template and reaction enzymes (including DNA polymerase, T4 polynucleotide kinase and deoxymononucleotide) were placed into two centrifuge tubes, respectively, and uniformly mixed to perform a denaturation step (95° C. for 5 min) and a renaturation step (65° C. for 10 min). About 25% of PCR products were DV ΔNC NS1 cDNAs with cohesive ends containing EcoRI and XhoII restriction sites. The ligation was accomplished by insertion of PCR products into a vector (pET28a).
[Recombinant Protein and Antibody Preparation]
[0033] JEV NS1, DV NS1, and N terminus (aa 1-35)-deleted and C terminus (aa 271-352)-deleted dengue virus nonstructural protein 1 (DV ΔNC NS1) cDNA were cloned into the above-mentioned vector with histidine-tag. Plasmids were introduced into Escherichia coli BL21. The recombinant proteins were induced by 1 μM isopropyl B-D-1-thiogalactopyranoside (Calbiochem) and purified with Ni 2+ columns. Subsequently, proteins were examined using 10% SDS-PAGE. Proteins from SDS-PAGE were excised and homogenized in adjuvant to immunize mice. Purified protein (25 μg) was emulsified in CFA for the first immunization, and 2 wk later in IFA for 2, 3 or 4 immunizations every week. Mouse sera were collected 3 days after the last immunization, and IgG was purified using protein G columns (Pharmacia Fine Chemicals).
[Antibody Binding to Platelet Assay]
[0034] Washed platelets were fixed with 1% formaldehyde in PBS at room temperature for 10 min and then washed with PBS. Various doses of anti-full-length DV NS1, anti-DV ΔNC NS1 or anti-JEV NS1 were incubated with platelets for 30 min. After washing, platelets were incubated with FITC-conjugated anti-mouse IgG (Jackson ImmunoResearch Laboratories) for 30 min. Antibody binding to platelets was analyzed using flow cytometry, as shown in FIG. 1 .
[0035] As shown in FIG. 1 , the binding ability of anti-DV ΔNC NS1 antibody to human platelets was lower than that of anti-full-length DV NS1 antibody, and similar to that of control IgG and anti-JEV NS1.
[Antibody Binding to Platelet Assay—Animal Model]
[0036] The antibody binding to platelet assay was performed on passively immunized mice with IgG (as a control), anti-full-length DV NS1, anti-DV ΔNC NS1 or anti-JEV NS1 Abs. The results are shown in FIG. 2 .
[0037] It can be found that the binding ability of anti-DV ΔNC NS1 antibody to platelets was significantly lower than that of anti-full-length DV NS1 antibody, and similar to that of control IgG and anti-JEV NS1.
[Bleeding Time]
[0038] Actively immunized mice with full-length DV NS1, DV ΔNC NS1 and JEV NS1 proteins and normal control mice with no above-mentioned proteins were tested on bleeding time. Bleeding time was performed by a 3-mm tail-tip transection. Blood droplets were collected on filter paper every 30 s for the first 3 min, and every 10 s thereafter. Bleeding time was recorded when the blood spot was smaller than 0.1 mm in diameter. The results are shown in FIG. 3 .
[0039] As shown in FIG. 3 , the bleeding time in N terminus (aa 1-35)-deleted and C terminus (aa 271-352)-deleted dengue virus nonstructural protein 1 (DV ΔNC NS1)-immunized mice was shorter than that in full-length DV NS1-immunized mice, and similar to that in normal control mice and JEV NS1-immunized mice. The results show that the dengue vaccine including N terminus (aa 1-35)-deleted and C terminus (aa 271-352)-deleted dengue virus nonstructural protein 1 (DV ΔNC NS1) according to the present invention indeed has the effect for shortening bleeding time.
[Antibody Binding to Endothelial Cell Assay]
[0040] The human microvascular endothelial cell line (HMEC-1) was available from Center for Disease Control and Prevention, Atlanta, Ga. The cells were cultured at 37° C. and washed by PBS, followed by the addition of trypsin-EDTA, and reacted for several minutes. Then, the cells were re-suspended in a fresh serum-containing medium in an appropriate amount. After centrifugation, the cells were fixed with 1% formaldehyde in PBS for 10 min and then washed with PBS. Diluted antibodies in an appropriate dose were incubated with the cells for 1 hr. After washing with PBS for three times, the cells were incubated with FITC-conjugated secondary antibodies for 1 hr. The amount of antibody binding to endothelial cells was analyzed using flow cytometry, as shown in FIG. 4 .
[0041] The results show that the binding ability of the anti-DV ΔNC NS1 antibody according to the present invention to endothelial cells was significantly lower than that of anti-full-length DV NS1 antibody, and similar to that of IgG antibody (as a control) and anti-JEV NS1 antibody. Therefore, it can be confirmed that the anti-DV ΔNC NS1 antibody according to the present invention does not cause autoimmunity.
[0042] Through sequence alignment analysis, the inventors of the present invention found that the N-terminal and C-terminal regions of DV NS1 protein contain epitopes involved in cross-reactivity to target proteins. Therefore, the present invention evaluated and compared the influence of the full-length DV NS1 protein and the N terminus (aa 1-35)-deleted and C terminus (aa 271-352)-deleted DV ΔNC NS1 on cross-reactivity and bleeding time. The experimental results showed that the binding ability of anti-DV ΔNC NS1 antibody to endothelial cells and platelets was lower than that of anti-full-length DV NS1 antibody. Through mouse models (animal models), it was found that the actively immunized mice with the full-length DV NS1 protein showed prolonged bleeding time, while the phenomenon was not found in the immunized mice with the DV ΔNC NS1 protein. The tests on passively immunized mice proved that the anti-DV ΔNC NS1 antibody showed lower binding ability to platelets and thus had better effect for the reduction of bleeding time compared to the anti-full-length DV NS1 antibody.
[0043] In conclusion, the vaccine including N and C termini-deleted DV ΔNC NS1 protein according to the present invention is depleted of cross-reactivity with endothelial cells and platelets, shortens bleeding time, and can avoid autoimmunity. In addition, DV ΔNC NS1 protein of the present invention is derived from dengue virus nonstructural protein rather than dengue virus envelope protein, and thus can be used as an inventive and practical vaccine without antibody dependent enhancement.
[0044] Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. | The present invention relates to a dengue vaccine, a pharmaceutical composition including the same, and a nucleotide sequence. The dengue vaccine includes N and C termini-deleted nonstructural protein ΔNC NS1 with a peptide fragment from amino acids 36 to 270, which is derived from dengue virus nonstructural protein 1 (DV NS1) with deletions of N-terminal region from amino acids 1 to 35 and C-terminal region from amino acids 271 to 352. The dengue vaccine of the present invention is depleted of cross-reactivity with endothelial cells and platelets, and can shorten the bleeding time. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to generally a high-pressure sodium lamp of the type whose transparent or translucent arc tube contains a metal such as mercury, cadmium or the like, which vaporizes to form the buffer gas, and sodium, and more particularly the electrodes of the arc tube.
In general, the electrodes of the high-pressure sodium lamps comprise an electrode core and an electrode coil wound around the electrode core in such a way that the electrode core is extended beyond the innermost electrode coil by a predetermined length. One end of the electrode coil, one end of a body of electron-emitting materials or one end of an inner coil carrying the electron-emitting materials (the body of electron-emitting materials and the inner coil are referred to as "the electron-emitting means" hereinafter in this specification) is exposed to the discharge space in which an arc is established, so that at each electrode, the arc spot; that is, the point of contact between the arc and the electrode fluctuates between the end face of the electrode core and the cylindrical surface thereof, one end of the electrode coil or especially one end of the electron-emitting means. As a result, sputtering of the electrode coil and evaporation of the electron-emitting means are accelerated to a considerably higher degree so that tube blackening is accelerated accordingly. In addition, even when a constant voltage is supplied through a stabilizer or ballast, the arc length varies, resulting in the variations in lamp voltage and electrical characteristics of the lamp. Furthermore, the arc spot fluctuation causes variations in operating temperature of the electrode which in turn cause temperature variations the coldest spot in the arc tube. As a consequence, variations in vapor pressure in the arc tube follow in the high-pressure sodium lamps of the saturated vapor type so that lamp voltage variations occur during the lamp life. As a consequence, the electrical as well as optical characteristics vary, so that the factors which influence the lamp life are adversely affected and consequently the lamp life is considerably shortened.
The above-described variations in lamp characteristics due to the arc spot fluctuations are especially pronounced in high-pressure sodium lamps with high-color-rendition in which the average potential gradient is higher than 20 V/cm.
One of the objects of the present invention is, therefore, to provide a high-pressure sodium lamp in which the arc spot fluctuations can be substantially suppressed during operation so that the electrical and optical characteristics of the lamp can be stabilized and the lamp life can be increased.
SUMMARY OF THE INVENTION
According to one preferred embodiment of the present invention, each of the electrodes at the ends of an arc tube filled or sealed with a buffer gas, generating metal and sodium comprises an electrode core, an electrode coil wound around the core, an electron-emitting means disposed in an annular space defined between the electrode core and coil and a shielding means disposed in the annular space in such a way that the electron-emitting means is not exposed to the discharge space, the electrode core being extended beyond the innermost end of the shielding means or the innermost coil of the electrode coil. In addition, the following dimensional relationship or ratio must be satisfied:
0.8≦h/d≦5.4
where h is the length in mm of the portion of the electrode core extended beyond the inner end of the shielding means or the innermost coil of the electrode coil; and d is the diameter in mm of the electrode core.
According to the present invention, therefore, the arc spots can be always maintained at the front faces of the electrode cores so that the arc length, the electrode temperature and the temperature at the coldest spot in the arc tube as well can be maintained almost constant and subsequently the variation in electrical as well as optical characteristics can be avoided, whereby the long lamp life can be ensured.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view, partly in section, of a preferred embodiment of a high-pressure sodium lamp in accordance with the present invention;
FIG. 2 is a side view, partly in section, on enlarged scale, of the electrode; and
FIG. 3 is a graph showing the comparison in lamp-voltage vs. lamp operating time between the high-pressure sodium lamps of the present invention and the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a high-pressure sodium lamp in accordance with the present invention comprises an evacuated outer jacket 1 and an arc tube 2 as with the conventional lamps. The arc tube 2 comprises a transparent alumina tube 8 mm in inner diameter and 9.6 mm in outer diameter. Niobium tubes 3 and 4 are gas-tightly fitted or inserted through the ends of the arc tube 2 and electrodes 5 and 6 are extended from the inner ends of the niobium tubes 3 and 4, respectively, and are spaced apart from each other by at least 31 mm.
Referring next to FIG. 2, the construction of the electrode 5 will be described since the electrodes 5 and 6 are similar in construction. The electrode 5 consists of a core 7 which is made of thoriated tungsten and is 0.9 mm in diameter d. A triple-coiled (CCC) shield coil 8 which is 0.5 mm in diameter and made of tungsten is wound two turns around the core 7 from the point spaced apart by h from the free or inner end of the core 7, and an inner triple-coiled (CCC) inner coil 9, which is 0.5 mm in diameter, made of tungsten and coated with electron-emitting compounds such as BaCO 3 , CaCO 3 , ThO 2 , etc., is wound six turns around the core 7 adjacent to the shield coil 8.
When a single coil is used as the shield coil 8, its weight becomes heavy and its heat capacity becomes higher so that when the lamp is started, a time interval is required to start the arc discharge after the glow discharge will become longer. During this time interval, excessive sputtering of the electrodes occurs so that the inner wall of the arc tube 2 is considerably blackened and consequently the light intensity drops and the lamp life is shortened. According to the present invention, therefore, among the recoiled or multiple-coiled coils which are light in weight and low in heat capacity, the triple-coiled filament is selected which is same as the inner triple-coiled inner coil 9.
The core 7 is extended by h=2.5 mm from the inner end of the shield coil 8. An electrode coil 10 which is 0.4 mm in diameter and is made of tungsten is wound 10 turns around the shield and inner coils 8 and 9.
Referring back to FIG. 1, sodium amalgam 11 consisting of 8 mg of sodium and 20 mg of mercury is filled in the arc tube 2 and the gas mixture comprising neon and argon is sealed at about 20 torr.
Metallic foils 12 and 13 made of tantalum are wrapped around the arc tube 2 adjacent to the ends thereof so as to surround the electrodes 5 and 6. They serve to reflect back the heat and light radiated from the arc tube 2 and more particularly from the electrodes 5 and 6 to the coldest spot at which the sodium amalgam remains so that the temperature at the coldest spot will rise. As a result, the vapor pressure in the arc tube 2 rises considerably. Furthermore, since the inner diameter of 8 mm of the arc tube 2 is considerably greater than that of a conventional high-pressure sodium lamp (150 W), the self-reversal of the sodium D lines occurs and the broadening of spectral lines in the visible range become larger. Thus, lamp color, especially color rendition superior to those attained by the conventional high-pressure sodium lamps can be obtained.
When the axial length of the metallic foils 12 and 13 are increased, the temperature at the coldest spot can be raised so that the vapor pressure in the arc tube 2 also rises. Therefore, it follows that the electrical characteristics and lamp color can be freely selected or controlled by changing the axial length of the metallic foils 12 and 13.
In this embodiment, the metallic foils 12 and 13 are 40 μm in thickness and 13.0 mm in axial length so that under the conditions that the lamp power is 150 W and the average potential gradient is maintained at from 29 to 35 V/cm; that is, the lamp voltage is maintained at from 90 to 110 V, the color temperature is maintained at about 2,500° K. and the average color rendering index Ra is maintained at higher than 80.
The arc tube 2 is supported in the outer jacket 1 by lead-in wires 14 and 15, supporting plates 16 and 17 and a supporting rod 18 made of an insulating material. The lower supporting plate 16 has its one end welded to the lead-in wire 14 and the other end securely joined to the lower end of the supporting rod 18. The upper end of the supporting rod 18 is loosely inserted into the niobium tube 3. A lead wire 19 is interconnected between the lead-in wire 14 and the niobium tube 3 so as to establish the electrical connection therebetween. One end of the upper supporting plate 17 is welded to the lead-in wire 15 while the other end thereof is welded to the upper or outer end of the upper niobium tube 4.
The lead-in wires 14 and 15 are extended through a glass stem 20 and joined to a center contact 23 and a shell or rim 22 of the base 21.
In each of the electrodes 5 and 6 of the arc tube 2, the inner coil 9 coated with the electron emitting compounds is completely surrounded by the electrode core 7, the shield core 8 and the electrode coil 10 so as to be isolated from the discharge space. In addition, part of the electron emitting compounds is sufficiently supplied to the inner end face of the core 7. Thus, during operation the arc spot is always formed at the front face of the core 7. As a result, the discharge arc length, the electrode temperature and the temperature at the coldest spot as well in the arc tube 2 can be maintained almost constant during operation so that the lamp characteristics described above can be maintained during the whole lamp life.
The high-pressure sodium lamp with the above-described construction was subjected to the tests in which the lamp was connected in series to a single-choke type stabilizer or ballast and was supplied with a constant voltage. The resultant lamp voltage variation is shown by the curve 31 in FIG. 3. During test, the arc spot formed at the front face of the core 7 remained stationary; the variation in lamp voltage were suppressed within 7 V; the lamp color remained unchanged; and the luminous flux maintained its initial level, because the blackening of the arc tube 2 was inhibited.
In the conventional high-pressure sodium lamps, the electrodes 5 and 6 are not provided with the shield coil 8 and instead the inner coil 9 is extended inwardly. Obviously, the inner ends or the innermost coil of the inner coil 9 is exposed to the discharge space so that the arc spot shifts from the end face of the core 7 to the cylindrical surface thereof or to the exposed end of the inner coil 9 and then returns to the end face. Thus, during the lamp life, the arc spots very frequently fluctuate at and adjacent to the inner ends of the electrodes 5 and 6 so that the lamp voltage varies very sharply and quickly. As a result, the average lamp voltage steeply increases so that the lamp color varies over a wide range and the blackening of the arc tube is accelerated, resulting in the sharp drop in lamp or luminous flux.
TABLE 1______________________________________(150 W: rated lamp voltage, 100V; turned on for 9000 hrs)Electrode MaximumCore Extension variation ofdiameter of core Shield lamp voltaged (mm) h (mm) h/d coil ΔV (V)______________________________________0.9 0.55 0.6 provided 31 0.7 0.8 provided 20 1.0 1.1 provided 15 1.5 1.7 provided 11 2.5 2.8 provided 7 3.5 3.9 provided 9 4.5 5.0 provided 15 4.9 5.4 provided 20 5.0 5.6 provided 21 5.5 6.1 provided 28 2.5 2.8 not 64 provided______________________________________
As shown in TABLE 1, even when the shield coil 8 is provided, when the ratio h/d is less than 0.8 or larger than 5.4, wide variation of lamp voltage results and consequently lamp color widely fluctuates. According to the results of the experiments conducted by the inventors, when the maximum lamp variation ΔV relative to the rated lamp voltage is less than 20 V, the variation in lamp color can be tolerated and when the lamp voltage variation ΔV is less than 15 V, the variation in lamp color can be minimized. From TABLE 1 it is seen that the lamp voltage variation of the lamp without the shield coil is excessively high as compared with those with the shield coil.
The reason why the wide variation of lamp voltage occurs when the ratio h/d is less than 0.8 or larger than 5.4 is as follows. When the extension h is short, the distance between the end face of the core 7 and the innermost coil of the inner coil 9 is shortened accordingly so that the arc spot shifts to the portion of the shield coil 8 which is exposed to the discharge space and then returns to the initial point; that is, the arc spot fluctuates. On the other hand, when the extension h is long, the supply of electron-emitting materials from the inner coil 9 to the end face of the core 7 through the core is insufficient so that the arc spot fluctuates.
TABLE 2______________________________________(rated lamp voltage, 100V; turned on for 9000 hrs)Electrode MaximumWatts Core variation ofof diameter Extension Shield lamp voltagelamp d (mm) h (mm) h/d coil ΔV (V)______________________________________ 70 W 0.7 0.5 0.7 provided 27 0.55 0.8 provided 20 0.7 1.0 provided 17 1.0 1.4 provided 13 1.5 2.1 provided 10 2.0 2.9 provided 8 3.0 4.3 provided 11 3.5 5.0 provided 15 3.8 5.4 provided 20 4.0 5.7 provided 25 2.0 2.9 not 60 provided400 W 1.2 0.5 0.4 provided 38 1.0 0.8 provided 20 2.0 1.7 provided 11 3.0 2.5 provided 9 4.0 3.3 provided 10 5.0 4.2 provided 11 6.0 5.0 provided 15 6.5 5.4 provided 20 7.0 5.8 provided 26 3.0 2.5 not 61 provided______________________________________
As shown in TABLE 2, the excellent characteristics can be obtained also with the core diameters of 0.7 and 1.2 mm. When the electron-emitting materials on the inner coil 9 is completely surrounded with the core 7, the shield coil 8 and the electrode coil 10 and is isolated completely from the discharge space and when the ratio h/d is equal to or larger than 0.8 and equal to or less than 5.4; that is, 0.8≦h/d≦5.4, excellent characteristics can be ensured not only with the so-called high-pressure sodium lamps with high-color-rendition in which the average potential gradient is maintained higher than 20 V/cm but also with the general high-pressure sodium lamps.
As seen from TABLES 1 and 2, the variation of lamp voltage is remarkably suppressed especially when 1.1≦h/d≦5.0, whereby excellent lamp characteristics and performance can be ensured.
So far the shielding means has been described as consisting of the triple-coiled coil 10, but it is to be understood that it may be in the form of a metallic ring or any other suitable form and that the present invention is not limited only to the electrode consisting of the triple-coiled coil 10. The electron-emitting materials have been described as being coated on the inner coil 9, but it is to be understood that the present invention is not limited thereto and that the inner coil 9 is eliminated and instead the electron-emitting materials is disposed in the above-described annular space of the electrode 5.
In this embodiment, the shielding means; that is, the shield coil 8 has been described and shown as being extended beyond the innermost coil of the electrode coil 10, but it is to be understood that the electrode coil 10 may be extended beyond the shield coil 8 or the innermost coils of the shield coil and inner electrode coils 8 and 9 may be aligned. | Each of the electrodes at the ends of an arc tube filled with a buffer gas, metal and sodium comprises an electrode core, an electrode coil wound around the core, an electron-emitting means disposed in the annular space between the electrode core and electrode coil and a shielding means disposed in said annular space in such a way that the electron-emitting means is shielded from exposure to the discharge space in the arc tube. The ratio h/d is determined such that 0.8≦h/d≦5.4, where h is the length in mm of the portion of the electrode core extended beyond the inner end of the shielding means or the innermost coil of the electrode coil; and d is the diameter in mm of the electrode core.
The arc spots can be held to remain on the end faces of the electrode cores during lamp operation so that variations in electrical and optical characteristics can be almost eliminated. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a terminal, a program, and an access point finding method for communicating with a stealth access point.
[0003] 2. Description of the Related Art
[0004] There is a MAC (Medium Access Control) layer technology for controlling packet transmission between an access point and a terminal in wireless LAN. A MAC frame that is exchanged between radio stations by a MAC layer is defined by, for example, IEEE802.11 standard.
[0005] FIG. 1 is a system configuration diagram that shows a sequence of between a terminal and an access point in a conventional art.
[0006] In an infrastructure mode of IEEE 802.11, an access point sends a beacon signal containing an ESSID (Extended Service Set IDentifier) that is a network identifier to peripheral terminals at regular intervals (approximately every 100 ms). A terminal that receives the beacon signal can connect to the access point using the ESSID. In this way, the terminal can easily find an access point (a network identifier) around the terminal. In other words, this means that all terminals can find respective network identifies.
[0007] Recently, in view of security, the use of stealth access points has increased. “Stealth access point” refers to an access point that does not report a network identifier such as an ESSID. To prevent ESSID from being reported, there are a case where a beacon signal is stopped and a case where a beacon signal containing no ESSID is reported. By using a stealth access point, it is allowed that an existence of network cannot be easily detected by peripherals. A terminal has to know an ESSID of a stealth access point to connect to the stealth access point.
[0008] The terminal sends a probe request containing an ESSID of a stealth access point to find the stealth access point. When attempting to find all access points around the terminal, the terminal makes the probe request contain ESSID=any.
[0009] The stealth access point determines whether or not the ESSID contained in the received probe request matches with its own ESSID. If they match, the stealth access point sends a probe response containing the ESSID back to the terminal. However, if the probe request in which ESSID=any is received, the stealth access point does not send a probe response back to the terminal.
[0010] As a conventional art, there is a technology in which a terminal changes an access point connected thereto depending on application as necessary (see, for example, Wenhui Zhang, Jurgen Juhnert, Klaus Dolzer, “Design and Evaluation of A Handover Decision Strategy for 4th Generation Mobile Networks”, IEEE VTC, April 2003, Jeju, Korea). According to this technology, a certain base station broadcasts access point information according to the spot coverage of the station. A terminal that has received this access point information can determine an access point to be searched for depending on its current position.
[0011] In the conventional art, the terminal does not recognize whether such an access point is a normal access point or a stealth access point. Therefore, the terminal needs to listen for a beacon signal from an access point (a network identifier) as well as to report probe requests to all of pre-registered access points at regular intervals.
[0012] In the conventional art, the presence or absence of stealth of an access point is not set in a terminal. Therefore, even if the terminal exists in a position where it cannot communicate with the stealth access point, the terminal reports probe requests to all of pre-registered access points at regular intervals and also changes receive frequencies. Such operation leads not only to waste of radio resource but also to waste of power consumption of the terminal. When a large number of stealth access points are placed for security reasons in future, there is the need to find many stealth access points, and the number of transmission packets is increased.
[0013] Therefore, the present invention is intended to provide a terminal, a program, and an access point finding method that can prevent the terminal from sending a useless probe request to detect a stealth access point.
SUMMARY OF THE INVENTION
[0014] According to the present invention, a terminal or device can communicate with a normal access point that reports a network identifier and a stealth access point that does not report a network identifier. The terminal includes access point information accumulating means for accumulating access point information that indicates whether each access point is a normal access point or a stealth access point. A beacon signal detecting means is included for listening for and detecting a beacon signal containing a network identifier. A probe request sending means is included for sending a probe request containing a network identifier. An access point finding control means is also included for controlling the beacon signal detecting means to detect the beacon signal with respect to the normal access point, and for controlling the probe request sending means to send the probe request with respect to the stealth access point.
[0015] According to another embodiment of the terminal of the present invention, the terminal may include a position measuring means for measuring a current position, wherein the access point information accumulating means contains spot coverage information in access point information of each access point, and wherein the access point finding control means controls the probe request sending means to send a probe request only to a stealth access point the spot coverage information of which includes the current position of the relevant terminal.
[0016] According to a further embodiment of the terminal of the present invention, the probe request sending means may preferably send a plurality of probe requests sequentially at a time interval that is shorter than a transmission interval of a normal probe request.
[0017] According to the present invention, a system that has the above-described terminal and a broadcast station that can send data to the terminal is characterized in that
[0018] the broadcast station broadcasts access point information that indicates whether each access point is a normal access point or a stealth access point; and
[0019] the terminal accumulates the received access point information in the access point information accumulating means.
[0020] According to the present invention, a program that causes a computer to function, the computer being provided in a terminal that can communicate with a normal access point that reports a network identifier and a stealth access point that does not report a network identifier, is characterized in that the program causes the computer to function as:
[0021] access point information accumulating means for accumulating access point information that indicates whether each access point is a normal access point or a stealth access point;
[0022] beacon signal detecting means for listening for and detecting a beacon signal containing a network identifier;
[0023] probe request sending means for sending a probe request containing a network identifier; and
[0024] access point finding control means for controlling the beacon signal detecting means to detect the beacon signal with respect to the normal access point, and controlling the probe request sending means to send the probe request with respect to the stealth access point.
[0025] According to another embodiment of the program for the terminal of the present invention, the program may preferably cause the computer to further function as:
[0026] position measuring means for measuring a current position,
[0027] wherein the access point information accumulating means contains spot coverage information in access point information of each access point, and
[0028] wherein the access point finding control means controls the probe request sending means to send a probe request only to a stealth access point the spot coverage information of which includes the current position of the relevant terminal.
[0029] According to a further embodiment of the program for the terminal of the present invention, the program may preferably cause the computer to function so that the probe request sending means sends a plurality of probe requests sequentially at a time interval that is shorter than a transmission interval of a normal probe request.
[0030] According to the present invention, an access point finding method in a terminal that can communicate with a normal access point that reports a network identifier and a stealth access point that does not report a network identifier, is characterized in that the method comprises:
[0031] an access point information accumulating section for accumulating access point information that indicates whether each access point is a normal access point or a stealth access point;
[0032] listening for and detecting a beacon signal containing a network identifier with respect to the normal access point; and
[0033] sending a probe request containing a network identifier with respect to the stealth access point.
[0034] According to another embodiment of the access point finding method of the present invention, it may be preferable that
[0035] the access point information accumulating section contains spot coverage information in access point information of each access point, and
[0036] the probe request sending comprises sending a probe request only to a stealth access point the spot coverage information of which includes the current position of the relevant terminal.
[0037] According to a further embodiment of the access point finding method of the present invention, the probe request sending may preferably comprise sending a plurality of probe requests sequentially at a time interval that is shorter than a transmission interval of a normal probe request.
[0038] According to a terminal, a program, and an access point finding method of the present invention, a probe request is not required to send to all of registered ESSIDs to find a stealth access point. Therefore, a terminal can reduce the number of transmissions of probe requests for finding a stealth access point, and radio resources of a network as well as power consumption of the terminal can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a system configuration diagram that shows a sequence of between a terminal and an access point in the conventional art;
[0040] FIG. 2 is a system configuration diagram according to the present invention; and
[0041] FIG. 3 is a sequence diagram according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0043] FIG. 2 is a system configuration diagram according to the present invention.
[0044] In FIG. 2 , a terminal or device 1 is shown in a position or location where it can communicate with a stealth access point 2 . In addition, the terminal 1 can receive peripheral access point information broadcasted from a broadcast station (or cellular base station) 3 .
[0045] The terminal 1 includes a beacon signal detecting section 101 , an access point finding control section 102 , an access point information accumulating section 103 , a position measuring section 104 , a probe request sending section 105 , an access point connection processing section 106 , and a peripheral access point information receiving section 107 . A program executed by a computer mounted in the terminal 1 may also implement these functional units.
[0046] The access point information accumulating section 103 accumulates access point information that indicates whether each access point is a normal access point or a stealth access point. The access point information accumulating section 103 accumulates a table, for example, as shown in the following table 1.
[0000]
TABLE 1
Access point information
Network
Type
Presence
Spot
identifier
of radio
Fre-
or absence
Priority
coverage
ESSID
system
quency
WEP
of stealth
level
information
[0047] ESSID refers to access point identifier, that is, “network identifier”. For each ESSID, “type of radio system”, “frequency”, and “WEP (Wired Equivalent Privacy)” are registered. According to the present invention, each ESSID further contains “presence or absence of stealth”, “priority level”, and “spot coverage information”.
[0048] The “presence or absence of stealth” indicates whether an access point of a relevant ESSID is a normal access point or a stealth access point. The “priority level” indicates an order of priority for access routers to which the terminal should connect, and ESSIDs are searched for in the order of descending priority levels. The “spot coverage information” indicates a spot coverage in which a terminal can communicate with an access point of a relevant ESSID. Spot coverage information is represented by, for example, the latitude and longitude of center point and the radius of a spot coverage.
[0049] The beacon signal detecting section 101 listens for and detects a beacon signal sent from a normal access point. When receiving a beacon signal, the beacon signal detecting section 101 notifies the access point finding control section 102 of the reception of the beacon signal.
[0050] A beacon signal is comprised of a MAC frame. The MAC frame is composed of “frame control”, “Duration ID”, “destination address”, “source address”, “BSSID (Basic Service Set IDentifier)”, “sequence control”, “frame body”, and “FCS”. A beacon signal is identified by “type” and “subtype” of the “frame control”. “Type=00” represents a management frame, and “subtype=1000” represents a beacon signal. The “BSSID” indicates a MAC address of an access point.
[0051] A message body of a beacon signal contains the following “beacon basic information”:
[0052] Timestamp: value of a timer TSFTIMER (in units of μs)
[0053] Beacon interval: beacon interval (in units of 1024 μs)
[0054] Capability Information: presence or absence of polling centralized control (PCF) or encryption
[0055] SSID (Service Set ID): ESSID or IBSSID
[0056] Supported Rate: a list of radio transmission rates supported by an access point
[0057] The probe request sending section 105 sends a probe request to the stealth access point 2 . The probe request contains an ESSID to be found. The probe request sending section 105 may preferably send a plurality of probe requests sequentially at a time interval that is shorter than a transmission interval of a normal probe request. For example, probe requests are sent three times in sequence, and then a probe response is waited for in a certain period of time. If a probe response is not received, finding of the next access point is attempted without sending a further probe request. Thereby, time for finding a stealth access point can be reduced.
[0058] The access point finding control section 102 switches means for finding an access point based on the “presence or absence of stealth” of access point information accumulated in the access point information accumulating section 103 . With respect to a normal access point, the beacon signal detecting section 101 detects a beacon signal. On the other hand, with respect to a stealth access point, the probe request sending section 105 is controlled to send a probe request. According to the present invention, the terminal sends a probe request only to a stealth access point and not to a normal access point. Such operation can reduce power consumption for the terminal to find an access point.
[0059] Then, the access point finding control section 102 controls the probe request sending section 105 to send a probe request only to a stealth access point the spot coverage information of which includes a current position of the relevant terminal. The current position of the relevant terminal is acquired from the position measuring section 104 . Additionally, the spot coverage information of the stealth access point is acquired from the access point information accumulating section 103 . Then, the access point finding control section 102 determines whether or not the current position of the relevant terminal exists within the spot coverage of the stealth access point. If it exists, the access point finding control section 102 instructs the probe request sending section 105 to send a probe request. Thus, the terminal 1 does not send a probe request to a stealth access point the spot coverage information of which does not include the current position of the terminal. Incidentally, the access point finding control section 102 searches for access points in the order of descending priority levels of access point information.
[0060] The position measuring section 104 measures a current position. For example, it acquires latitude/longitude information by a positioning function such as a GPS (Global Positioning System).
[0061] The access point connection processing section 106 processes a connection sequence with respect to an access point (a network identifier) found by the access point finding control section 102 . When receiving a beacon signal or a probe response, the access point connection processing section 106 sends an association request to the access point 2 and processes the connection sequence.
[0062] The peripheral access point information receiving section 107 receives peripheral access point information from a broadcast station 3 . The peripheral access point information is accumulated in the access point information accumulating section 103 . Thereby, the terminal can recognize neighbor access points at its current position.
[0063] In FIG. 2 , the stealth access point 2 includes a probe request receiving section 201 , an ESSID determination section 202 , a probe response sending section 203 , and a terminal connection processing section 204 .
[0064] The probe request receiving section 201 receives a probe request from the terminal 1 . An ESSID contained in the received probe request is notified to the ESSID determination section 202 .
[0065] The ESSID determination section 202 determines whether or not the ESSID received from the probe request receiving section 201 matches with an ESSID of the stealth access point itself. If they match, notification of this fact is given to the probe response sending section 203 .
[0066] When the probe response sending section 203 is notified from the ESSID determination section 202 that the ESSIDs are identical, the probe response sending section 203 sends a probe response to the terminal 1 . The probe response contains the same information elements as in the beacon signal.
[0067] The terminal connection processing section 204 processes a connection sequence with the terminal 1 . The terminal connection processing section 204 receives an association request from the terminal 1 and processes the connection sequence.
[0068] FIG. 3 is a sequence diagram according to the present invention.
[0069] (S 301 ) The broadcast station (or cellar base station) 3 is broadcasting peripheral access point information of neighbor access points. Such peripheral access point information contains, among others, “presence or absence of stealth”, “spot coverage information”, and “priority level”.
[0070] (S 302 ) The terminal 1 accumulates the peripheral access point information received from the broadcast station 3 .
[0071] (S 303 ) The terminal 1 searches for an access point to which the terminal in the current position can connect based on the “spot coverage information” of the access point information.
[0072] (S 304 ) The terminal 1 determines the order of “priority levels” of the access points found by searching.
[0073] (S 305 ) In the case of finding a normal access point, a frequency used by the normal access point is set.
[0074] (S 306 ) Then, the terminal 1 listens for a beacon signal sent from the normal access point 2 for a certain period of time.
[0075] (S 307 ) The normal access point 2 sends a beacon signal containing an ESSID at regular intervals. The terminal 1 receives such a beacon signal.
[0076] (S 308 ) Upon receiving the beacon signal, the terminal 1 processes a connection sequence with respect to the normal access point 2 .
[0077] (S 309 ) In the case of finding a stealth access point, a frequency used by the stealth access point is set, and an ESSID and a WEP are identified.
[0078] (S 310 ) The terminal 1 sends a probe request containing the ESSID to the stealth access point 2 .
[0079] (S 311 ) The stealth access point 2 determines whether or not the ESSID contained in the probe request matches with its own ESSID.
[0080] (S 312 ) If they match, the stealth access point 2 sends a probe response back to the terminal 1 .
[0081] (S 313 ) Upon receiving the probe request, the terminal 1 processes a connection sequence with respect to the stealth access point 2 .
[0082] As described above, according to the terminal, program, and access point finding method regarding the present invention, a probe request is not required to send to all of registered ESSIDs to find a stealth access point. Therefore, a terminal can reduce the number of transmissions of probe requests for finding a stealth access point, and radio resources of a network as well as power consumption of the terminal can be reduced.
[0083] In the foregoing various embodiments of the present invention, various alterations, modifications, and omissions may be readily made by those skilled in the art without departing from the spirit and scope of the present invention. The foregoing description is only illustrative and is not intended to limit the present invention. The present invention is limited only by the appended claims and equivalents thereof. | There is provided a terminal that is capable of not sending a useless probe request to detect a stealth access point. The terminal communicates with a normal access point that reports a network identifier and a stealth access point that does not report a network identifier. The terminal includes an access point information accumulating section 103 for accumulating access point information that indicates whether each access point is a normal access point or a stealth access point, a beacon signal detecting section 101 for listening for and detecting a beacon signal, a probe request sending section 105 for sending a probe request, and an access point finding control section 102 for controlling the beacon signal detecting section 101 to detect the beacon signal with respect to the normal access point, and controlling the probe request sending section 105 to send the probe request with respect to the stealth access point. | 7 |
This application is a divisional of U.S. patent application Ser. No. 08/296,970 filed on Aug. 26, 1994 now U.S. Pat. No. 5,507,932
BACKGROUND
1. The Field of the Invention
This invention relates to apparatus and methods for electrolyzing fluids and more particularly relates to apparatus and methods for electrolyzing saline solutions for use in medical treatments.
2. The Prior Art
It has long been known that the electrolysis of fluids can result in useful products. In particular, the electrolysis of saline solution results in the production of chlorine and ozone. It is known that the products resulting from the electrolysis of saline solutions are in vitro microbicides for hard surfaces. Thus, various apparatus and methods have been proposed for electrolyzing saline solution, however, all of the previously available schemes present one or more drawbacks.
For example, U.S. Pat. Nos. 4,236,992 and 4,316,787 to Themy disclose an electrode, method and apparatus for electrolyzing dilute saline solutions to produce effective amounts of disinfecting agents such as chlorine, ozone and hydroxide ions. One apparatus for producing electrolyzed saline solutions was previously available under the trade name Ster-O-Lizer. Laboratory reports and other data available from testing of electrolyzed saline solutions from various Ster-O-Lizer models have shown that it is effective in keeping water free of pathogenic organisms. Tests conducted in vitro further show that certain microorganisms, inclusive of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Candida albicans, and Salmonella typhi, are non-infectious after exposure to electrolyzed saline solutions.
For many years, ozone (O 3 ) has been used for the treatment of viral infections. Chlorine, in the form of chlorinated lime, was used successfully as early as 1846 to prevent and fight puerperal fever. By 1911, the U.S. purified as much as 800,000,000 gallons of water through the chlorination process. Wide use of chlorine as a 0.05% sodium hypochlorite solution (Dakins Solution) for open and infected wounds began in 1915. Dakins Solution was a standard product up to 1963 listed in the British Pharmacopeia.
As reported by Wilk et al., International Congress on Technology and Technology Exchange, First Euro-American Symposium, Paris, France (1992) and Science, Total Environment, 63:191-197 (1987), certain combinations of ozone and chlorine have significantly greater activity than either used separately against a variety of bacteria including Staphylococcus aureus and Pseudomonas aeruqinosa. Candida albicans was also reported to be effectively killed by a combination of ozone and chlorine.
In view of the many uses of chlorine and ozone, numerous apparatus and methods have been proposed for generating chlorine and ozone. Significantly, the previously available apparatus and methods have not been well-suited to producing electrolyzed saline containing finite amounts of ozone and chlorine for treatment of physiological fluids for the destruction of microbes in warm blooded animals. It has recently been discovered that there are situations where physiological fluids can be beneficially treated using electrolyzed saline solutions. The treatment of physiological fluids such as whole blood, plasma or cell isolates by electrolyzed saline solution which renders them benign from infectious organisms without destroying the therapeutic characteristics of such fluids is now possible. Disadvantageously, the available apparatus and methods for generating chlorine and ozone are not well-suited for treatment of physiological fluids such as whole blood, plasma, or cell isolates.
Methods for treatment of physiological fluids using electrolyzed solutions are set forth in U.S. patent application Ser. No. 07/527,321 filed May 23, 1990 (now U.S. Pat. No. 5,334,383 issued Aug. 2, 1994) and 08/275,904 filed Jul. 15, 1994, all of which are now incorporated herein by reference in their entireties. In these documents, an electrolyzed saline solution, properly made and administered in vivo, is effective in the treatment of various infections brought on by invading antigens and particularly viral infections. Thus, it would be a great advance in the art to provide an apparatus and method for electrolyzing saline solution for administration in vivo.
BRIEF SUMMARY AND OBJECTS OF THE INVENTION
In view of the above described state of the art, the present invention seeks to realize the following objects and advantages.
It is an object of the present invention to provide an apparatus and method for electrolyzing saline solutions which are particularly suitable for administration in vivo.
It is also an object of the present invention to provide an apparatus and method for electrolyzing fluids which does not introduce harmful substances into the fluid.
It is a further object of the present invention to provide an apparatus and method for electrolyzing saline solutions which is reliable and can be economically operated.
These and other objects and advantages of the invention will become more fully apparent from the description and claims which follow, or may be learned by the practice of the invention.
The present invention provides and an apparatus for electrolyzing fluids. The resulting electrolyzed fluids, such as a saline solution, are particularly suited for treating physiological materials such as whole blood, plasma or cell isolates in order to reduce the effect of harmful microorganisms.
A preferred embodiment of the present invention includes a container means for holding a fluid which is to be electrolyzed. A power supply means provides a source of electrical current. At least a first anode and a second anode are connected to the power supply means. The anodes and cathodes are positioned within the container means so as to be immersed in the fluid to be electrolyzed.
The anode comprises a base metal. The base metal is a metal selected from the group consisting of titanium and niobium. An outer layer of platinum is bonded to the base. The anode comprises a cylindrical shape.
The cathode is also connected to the power supply means. The cathode preferably comprises titanium or niobium and also has a substantially cylindrical shape. The cathode is positioned concentrically in relation to the anode. The spacing between the cathode and the anode is not greater than a preferred amount. Moreover the voltage potential between the cathode and the anode is not greater than a preferred amount.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to better appreciate how the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
FIG. 1 is a perspective view of a first presently preferred embodiment of the present invention.
FIG. 2 is a detailed top view of the electrode assembly represented in FIG. 1.
FIG. 3 is a side cross sectional view of the electrode assembly taken along line 3--3 in FIG. 2.
FIG. 4 is a block diagram of a second presently preferred embodiment of the present invention.
FIG. 5 is a top view of an electrode assembly preferred for use in the apparatus represented in FIG. 4.
FIG. 6 is a cross sectional view taken along line 6--6 of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made to the drawings wherein like structures will be provided with like reference designations.
Referring first to FIG. 1, which is a perspective view of a first presently preferred embodiment of the present invention generally represented at 100, includes a power supply 102 and a fluid receptacle represented at 104. The fluid receptacle 104 includes a base 114 upon which is attached a fluid vessel 116. The base 114 can preferably be fabricated from an insulative plastic material. The fluid vessel 116 is preferably fabricated from an inert clear plastic material which is compatible with biological processes as available in the art.
A lid 118 is provided to cover the fluid vessel 116 and keep contaminants out of the fluid vessel 116. A screen 120 is positioned to prevent foreign objects, which might accidentally fall into the fluid vessel 116, from falling to the bottom of the fluid vessel 116. The saline solution which is to be treated is placed into the fluid vessel 116, and the lid 118 placed, for the necessary period of time after which the electrolyzed saline solution can be withdrawn from the fluid vessel 116, for example into a syringe, for use. The fluid vessel 116 is sealed at its bottom by a floor 124 which is attached to the interior of the base 114.
An electrode assembly, generally represented at 122, is attached to the floor 124 so that any fluid in the fluid vessel is exposed to the electrode assembly 122. The electrode assembly 122 is electrically connected to the power supply 102 via terminals 110 and 112 and cables 106 and 108, respectively. The power supply 102 should deliver a controlled voltage and current to the electrode assembly 122 when fluid is placed into the fluid vessel 116. The voltage and current applied to the electrode assembly 122 will vary according to the fluid being electrolyzed. A control for setting and measuring the voltage 102A and a control for setting and measuring the current 102B is provided in the power supply. In accordance with the present invention, a low voltage of less than about 30 volts DC is used. Exemplary voltage and current values, and the advantages which accrue when using the preferred voltage and current values, will be explained shortly.
FIG. 2 is a top view of the electrode assembly 122 represented in FIG. 1. The electrode assembly 122 preferably comprises a cylindrical inner electrode 128 and a cylindrical outer electrode 126. The inner electrode 128 is preferably solid or any hollow in the inner electrode is sealed so that fluid does not enter any such hollow. The cylindrical shape of the inner electrode 128 and the outer electrode 126 is preferred and results in better performance than obtained with electrodes of other shapes, e.g., elongated flat panels.
The diameter A of the inner electrode 128 is preferably about one-half inch but the diameter A of the inner electrode can be selected by those skilled in the art in accordance with the particular application for the electrode using the information contained herein. The outer electrode 126 should be of a generally cylindrical shape and preferably be fabricated from titanium or niobium having a thickness (indicated at B in FIG. 2) which ensures that the inner electrode is shielded from potentially physical damage. As will be appreciated, titanium and niobium provide the advantage of resistance against corrosion which further prevents the introduction of harmful substances into the fluid being electrolyzed.
Still referring to FIG. 2, the space, indicated at C, between the inner electrode 128 and the outer electrode 126 does not exceed a maximum value. In contrast to previously available devices which separate the electrodes by greater distances and then utilize higher voltages to obtain the desired electrolyzation, the present invention keeps the electrode spacing small and obtains improved performance over other schemes. It is preferred that the space between the inner electrode 128 and the outer electrode 126 be not more than about one-half (1/2) inch; it is more preferred that the space between the inner electrode 128 and the outer electrode 126 be not more than about three-eights (3/8) inch; and, it is most preferred that the space between the inner electrode 128 and the outer electrode 126 be not more than about one-quarter (1/4) inch.
Reference will next be made to FIG. 3 which is a side cross sectional view of the electrode assembly taken along line 3--3 in FIG. 2. As seen in FIG. 3, the outer electrode 126 extends above the inner electrode 128 to provide improved electrical performance and physical protection. The outer electrode 126 is attached to the floor 124 by way of bolts 130, which extend through bores provided in the floor 124, and accompanying nuts. An electrical connection is made to the outer electrode 126 by a lead 136 attached to the bolt and nut. The lead 136 is attached to one of the terminals 110 or 112. Similarly, an electrical connection is made to the inner electrode 128 by a lead 134 which is held in place by a nut attached to a threaded stud extending from the bottom of the inner electrode and through a bore provided in the floor 124. The lead 134 is attached to the remaining one of the terminals 110 or 112. The leads 134 and 136 are kept insulated from any fluid which is present in the fluid vessel 116.
It is preferred that the inner electrode 128 function as the anode while the outer electrode function as the cathode when electrolyzing fluids and the power supply 102 and the terminals 110 and 112 should be properly arranged to carry this out.
It is recognized in the art that the anode is subject to destructive forces during electrolysis. In the prior art, the anode of an electrode assembly may dissolve to the point of being inoperative and may need to be replaced very often. Critically, as the anode of an electrode assembly dissolves, the metallic components of the anode are dispersed into the fluid. If the fluid is a saline solution which will be used to treat physiological fluids, toxic substances dispersed into the solution, such as the materials comprising the anode, may be harmful or dangerous to the person who expects to be benefitted from the treatment.
Of all the possible materials for fabrication of the anode, the art recognizes that platinum is the least likely to be dissolved when used as an anode. Unfortunately, the cost of platinum precludes the use of an anode which consists entirely of platinum. Thus, it is common in the art to utilize another metal as a base for the anode with a layer of platinum being placed on surfaces which contact the fluid to be electrolyzed.
The present invention advantageously utilizes an inner electrode 128, i.e., an anode, which includes a base of titanium, and even more preferably niobium (also known as columbium), upon which a layer of platinum is provided wherever fluid contacts the anode. Significantly, niobium is a relatively good electrical conductor having a conductivity which is about three times greater than the conductivity of titanium. Moreover, if the base metal is exposed to the fluid, such as if a pinhole defect develops, toxic products are not produced by the contact between niobium and the fluid. Moreover, the high breakdown voltage in saline solution of the oxide which forms when a niobium base receives a layer of platinum provides further advantages of the present invention.
Upon a base of niobium, a layer of platinum is formed on the anode. The layer of platinum is preferably formed using a technique referred to in the art as brush electrodeposition which can be carried out by those skilled in the art using the information set forth herein. Other techniques can also be used to form the platinum layer, such as tank (immersion) electrodeposition, vapor deposition, and roll bonding, but brush electrodeposition is preferred because of its superior adhesion and resulting less porosity than other economically comparable techniques.
The thickness of the platinum layer is preferably greater than about 0.02 mils and is most preferably greater than about 0.06 mils, and up to about 0.20 mils. The combination of using niobium as a base for the anode of the electrode assembly and utilizing brush electrodeposition provides that the platinum layer can be much thinner than otherwise possible and still provide economical and reliable operation. It will be appreciated by those skilled in the art, that even with an anode fabricated in accordance with the present invention replacement of the anode, which preferably comprises the inner electrode 128 represented in FIG. 3, may be necessary after a period of use. The construction of the embodiments of the present invention facilitate replacement of the inner electrode 128 and the outer electrode 126 when it becomes necessary.
Represented in FIG. 4 is a block diagram of a second presently preferred embodiment, generally represented at 150, of the present invention. The embodiment represented in FIG. 4 is particularly adapted for treating large quantities of saline solution. Represented in FIG. 4 is a tank 152 in which the saline solution is electrolyzed. An electrode assembly 154 is provided in the tank and is preferably immersed into the solution. A power supply 158, capable of providing sufficient current at the proper voltage, is connected to the electrode assembly via a cable 160.
Also represented in FIG. 4 is a circulation device 156 which optionally functions to circulate the solution within the tank 152. A sensor 162 is also optionally provided to measure the progress of the electrolyzation of the solution in the tank 152, for example by measuring the pH of the solution. The sensor may preferably be an ion selective electrode which can be chosen from those available in the art. Other sensors, for example chlorine, ozone, and temperature sensors, may also be included within the scope of the present invention. A control unit 164 is optionally provided to coordinate the operation of the power supply 158, the circulation device 156, and the sensor 162 in order to obtain the most efficient operation of the apparatus 150.
It will be appreciated that devices such as power supply 158, circulation device 158, sensor 162, and control unit 164 can be readily obtained from sources in the industry and adapted for use with embodiments of the present invention by those skilled in the art using the information contained herein. In particular, the control unit 164 is preferably a digital microprocessor based device accompanied by appropriate interfaces all allowing for accurate control of the operation of the apparatus 150. It is also within the scope of the present invention to include structures to prevent contamination of the treated solution by contact with nonsterile surfaces and by airborne pathogens both during treatment and while the fluid is being transferred to the apparatus and being withdrawn from the apparatus.
Reference will next be made to FIGS. 5 and 6 which are a top view and cross sectional view, respectively, of an electrode assembly, generally represented at 154, which is preferred for use in the apparatus represented in FIG. 4. As can be seen best in FIG. 5, the electrode assembly 154 includes a plurality of concentrically arranged anodes and cathodes. The cylindrical shape and concentric arrangement of the electrodes represented in FIG. 5 provides for the most efficient operation. The number of electrodes which are included can be selected according to the application of the apparatus. For example, the number of electrodes may be six, seven, eight, the eleven represented in FIGS. 5 and 6, or more.
In FIG. 5, electrodes 170, 174, 178, 182, 186, and 190 preferably function as cathodes and are preferably fabricated in accordance with the principles set forth above in connection with the outer electrode represented at 126 in FIGS. 1-3. Furthermore, in FIG. 5 electrodes 172, 176, 180, 184, and 188 function as anodes and are preferably fabricated in accordance with the principles set forth above in connection with the inner electrode represented at 128 in FIGS. 1-3.
In the cross sectional side view of FIG. 6 a plurality of tabs extend from the cylindrical electrodes 170, 172, 174, 176, 178, 180, 182, 184, 186, and 190 to facilitate making an electrical connection thereto. Provided below in Table A are the relationship between the tabs illustrated in FIG. 6 and the electrodes.
TABLE A______________________________________Electrode Tab Function______________________________________170 170A Cathode172 172A Anode174 174A Cathode176 176A Anode178 178A Cathode180 180A Anode (Not illustrated in FIG. 6)182 182A Cathode184 184A Anode186 186A Cathode188 188A Anode (Not illustrated in FIG. 6)190 190A Cathode______________________________________
Using the tabs 170A, 172A, 174A, 176A, 178A, 180A, 182A, 184A, 186A, 188A, and 190A, those skilled in the art can provide the necessary electrical connections to the electrodes 170, 172, 174, 176, 178, 180, 182, 184, 186, and 190 and can also provide numerous structures to prevent contact between the tabs and the fluid to be treated. Each of the tabs illustrated in FIG. 6 are provided with an aperture, such as those represented at 172B, 176B, and 184B, which receive a wiring connector.
While the apparatus described herein has many uses, the most preferred use of the apparatus described herein is subjecting sterile saline solution to electrolysis. The electrolyzed saline solution can then be used to treat a patient. The saline solution preferably has an initial concentration in the range from about 0.25% to about 1.0% NaCl which is about one-fourth to full strength of normal or isotonic saline solution. According to Taber's Cyclopedic Medical Dictionary, E. A. Davis, Co. 1985 Ed., an "isotonic saline" is defined as a 0.16 M NaCl solution or one containing approximately 0.95% NaCl; a "physiological salt solution" is defined as a sterile solution containing 0.85% NaCl and is considered isotonic to body fluids and a "normal saline solution;" a 0.9% NaCl solution which is considered isotonic to the body. Therefore, the terms "isotonic," "normal saline," "balanced saline," or "physiological fluid" are considered to be a saline solution containing in the range from about 0.85% to about 0.95% NaCl. Moreover, in accordance with the present invention, a saline solution may be subjected to electrolysis at concentrations in the range from about 0.15% to about 1.0%.
It is preferred that one of the above described saline solutions be diluted with sterile distilled water to the desired concentration, preferably in the range from about 0.15% to about 0.35% prior to treatment in accordance with the present invention. This dilute saline solution is subjected to electrolysis using the embodiments of the present invention at a voltage, current, and time to produce an appropriately electrolyzed solution as will be described shortly. It is presently preferred to carry out the electrolysis reaction at ambient temperatures.
The voltage and current values provided herein are merely exemplary and the voltage and current values which are used, and the time the saline solution is subject to electrolysis, is determined by many variables, e.g., the surface area and efficiency of the particular electrode assembly and the volume and/or concentration of saline solution being electrolyzed. For electrode assemblies having a different surface area, greater volumes of saline solution, or higher concentrations of saline solutions the voltage, current, or time may be higher and/or longer than those exemplary values provided herein. In accordance with the present invention, it is the generation of the desired concentration of ozone and active chlorine species which is important. Electrolyzation of the saline solution also results in other products of the electrolysis reaction including members selected from the group consisting of hydrogen, sodium and hydroxide ions. It will be appreciated that the interaction of the electrolysis products results in a solution containing bioactive atoms, radicals or ions selected from the group consisting of chlorine, ozone, hydroxide, hypochlorous acid, hypochlorite, peroxide, oxygen and perhaps others along with corresponding amounts of molecular hydrogen and sodium and hydrogen ions.
According to Faraday's laws of electrolysis, the amount of chemical change produced by a current is proportional to the quantity of electrons passed through the material. Also, the amounts of different substances liberated by a given quantity of electrons are proportional to the chemical equivalent weights of those substances. Therefore, to generate an electrolyzed saline having the desired concentrations of ozone and active chlorine species from saline solutions having a saline concentration of less than about 1.0%, voltage, current, and time parameters appropriate to the electrodes and solution are required to produce an electrolyzed solution containing in the range from about 5 to about 100 mg/L of ozone and a free chlorine content in the range from about 5 to about 300 ppm. For in vitro use these solutions can be utilized without further modification or they can be adjusted as desired with saline or other solutions. Prior to in vivo use, the resulting solution may be adjusted or balanced to an isotonic saline concentration with sufficient hypertonic saline, e.g., 5% hypertonic saline solution.
In general, the electrolyzed solutions produced using the apparatus described herein, which are referred to as microbicidal solutions, will have an ozone content in the range from about 5 to about 100 mg/L and an active chlorine species content in the range from about 5 to about 300 ppm. More preferably the ozone content will be in the range from about 5 to about 30 mg/L and the active chlorine species content will be in the range from about 10 to about 100 ppm. Most preferably the ozone content will be in the range from about 9 to about 15 mg/L and the active species content will be in the range from about 10 to about 80 ppm. By active chlorine species is meant the total chlorine concentration attributable to chlorine content detectable by a chlorine ion selective electrode and will be selected from the group consisting of chlorine, hypochlorous acid and hypochlorite ions or moieties.
The pH of the solution is preferably in the range from about 7.2 to about 7.6 and, when used for intravenous administration, most preferably in the range from about 7.35 to about 7.45 which is the pH range of human blood. An effective amount of the resulting balanced microbicidal saline solution is administered by appropriate modes, e.g., intravenously, orally, vaginally or rectally and may vary greatly according to the mode of administration, condition being treated, the size of the warm-blooded animal, etc.
Particular dosages and methods of administration, as well as additional components to be administered, can be determined by those skilled in the art using the information set forth herein and set forth in the U.S. patent documents previously incorporated herein by reference. As explained in the cited U.S. patent documents, although it is known that electrolyzed saline solutions possess in vitro microbicidal activity it has long been thought that components in the electrolyzed solution, such as ozone and chlorine, are toxic to warm blooded animals and should not be utilized for in vivo purposes. It has now been found, however, that saline solutions, which have been subjected to electrolysis to produce finite amounts of ozone and active chlorine products, can be injected into the vascular system to create a reaction to assist in the removal, passivation, or destruction of a toxin.
In order to arrive at the preferred end product, electrolyzed saline solution using the apparatus illustrated in FIGS. 1-3, about a 0.33% (about one third physiologically normal) saline solution is placed in the fluid vessel 116 (FIG. 1) and the apparatus is operated for about 5 to 15 minutes with a voltage between the electrodes being maintained in the range from about 10 volts to about 20 volts with a current flow maintained in the range from about 5 to about 20 amps.
As one example of the use of the embodiment of FIGS. 1-3, a 0.225% saline solution is subjected to a current of 3 amperes at 20 volts (DC) for a period of three minutes. A 17 ml portion of this electrolyzed solution is aseptically diluted with 3 mls of a sterile 5% saline resulting in a finished isotonic electrolyzed saline having an active ozone content of 12±2 mg/L and an active chlorine species content of 60±4 ppm at a pH of 7.4.
It will be appreciated that the low voltages used in accordance with the present invention are preferably not greater than forty (40) volts DC or an equivalent value if other than direct current is used. More preferably, the voltages used in accordance with the present invention is not more than about thirty (30) volts DC. The use of low voltages avoids the problem of production of undesirable products in the fluid which can result when higher voltages are used. In accordance with the present invention, the close spacing of the electrodes facilitates the use of low voltages.
In another example, to show that the embodiment of FIGS. 1-3 can be used to effectively carry out electrolysis in saline solutions up to about 1% in concentration, the electrolysis reaction is carried out at saline concentrations of 0.3, 0.6 and 0.9%, respectively. The active chlorine species (Cl 2 ) and ozone (O 3 ) contents were measured and are provided in Table B.
TABLE B______________________________________Cl.sub.2 and O.sub.3 Content from salines at Varying ConcentrationsSaline Cl.sub.2Concentration Concentration O.sub.3 Concentration(% NaCl) (ppm) (mg/mL)______________________________________0.3 129 21.80.6 161 26.60.9 168 28.0______________________________________
As can be seen from Table B, the resulting electrolyzed saline solution includes active components which are within the parameters required for effective treatment.
It will be appreciated that the features of the present invention, including the close electrode spacing, the low voltages used, and the materials used to fabricate the electrodes, result in an apparatus which provides unexpectedly better results than the previously available devices and schemes.
From the foregoing, it will be appreciated that the present invention provides an apparatus and method for electrolyzing saline solutions which are particularly suitable for administration in vivo and which does not introduce harmful substances into the electrolyzed fluid. The present invention also provides an apparatus and method for electrolyzing saline solutions which is reliable and can be economically operated.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | An apparatus for electrolyzing fluids is disclosed. The resulting electrolyzed fluids are particularly suited for treating physiological materials such as whole blood, plasma, or cell isolates in order to reduce the effect of harmful microorganisms. A container holds the fluid and a power supply provides a source of electrical current to an anode and a cathode positioned within the container. The anode comprises a base material selected from titanium and niobium. An outer layer of platinum is bonded to the base. The anode comprises a cylindrical shape. The cathode is also connected to the power supply and comprises titanium and has a substantially cylindrical shape. The cathode is positioned concentrically in relation to the anode. The spacing between the cathode and the anode is not greater than a preferred amount. Moreover, the voltage potential between the cathode and the anode is not greater than a preferred amount. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to data transmission systems, and more particularly to a digital audio transmission system for transmitting broadcast or production quality audio program material over the intercontinental network of the common carriers such as the telephone companies.
The American Telephone and Telegraph Company Technical Advisory No. 34 establishes an interconnection specification for digital cross-connects. The described network is a digital hierarchy to accommodate sources of digital signals which operate at different bit rates. At any given hierarchy level the different digital signal sources must have certain common characteristics to permit interconnection with the common carrier transmission facilities at that level as well as with multiplexers connecting that level to a higher level. The present defined levels are: DS1 (1.544 Mb/s), DS1C (3.152 Mb/s), DS2 (6.312 Mb/s), DS3 (44.736 Mb/s) and DS4 (274.176 Mb/s). Digital equipment is terminated at a standard level cross-connect (DSX-N), and the interconnection specifications for the cross-connect describe the required characteristics for the digital equipment interconnected by the cross-connect.
The DS1 signal is the lowest level in the digital hierarchy at 1.544 Mb/s, but is sufficient to provide for quality transmission of audio signals The DSX-1 specification requires that the digital signals be bipolar with at least 12.5 percent average ones density and no more than fifteen consecutive zeros. The pulses shall fit within an essentially square wave template with a specified pulse amplitude. One DS1 signal normally contains 24 DS0 signals, where a DS0 signal is one normal telephone call. This telephone audio information is received at the central office on a standard twisted pair cable and sampled at a rate of 8 kHz with a resolution of 8 bits. The 24 DS0 8-bit samples are then time division multiplexed with the addition of one framing bit to form a 193-bit frame. The frame rate is the same as the DS0 sampling rate of 8 kHz, thus leading to a data rate for the DS1 channel of 1.544 Mb/s. A master frame is composed of 193-bit subframes of two types, timing and signaling. The timing frames are so named because the framing bit is used to extract the synchronization information of the master frame at a receiver, and the signaling frames are so named because in these frames DS0 bits may be overridden by telephone company signaling information. These two types of frames alternate.
What is desired is a method for transmitting high precision analog signals, such as studio quality audio signals, over common carrier networks in a manner compatible with the common carrier cross-connect system.
SUMMARY OF THE INVENTION
Accordingly the present invention provides a digital audio transmission system which is compatible with the digital common carrier cross-connect system. The two channels of a high precision stereo audio signal are time division multiplexed into a common carrier defined frame. The audio signal is sampled at a high frequency, coded linearly to a 16-bit resolution and one-bit parity coded. Each frame has six samples of one channel and five samples of the other channel, with the next frame having five samples of the one channel and six samples of the other channel, so that eleven samples of each channel are transmitted for each two frames. The 16-bit samples are scrambled so that first the even bits are transmitted and then the odd bits, and each of these 8-bit groups are tested for all zeros. If there are all zeros in a group, then the least significant bit is set to one, thus guaranteeing a 12.5 percent ones density and no more than fourteen consecutive zeros. At a receiver the frames are decoded and the 16-bit samples are reconstructed and checked for parity. The samples are converted to analog, with those samples having a parity error being replaced with a valid sample. The analog signal is sampled at a rate to restore the two channels of the audio signal. The result is that a high precision stereo audio signal may be transmitted over a common carrier network while maintaining the precision quality of a compact disc.
Other objects, advantages and novel features of the present invention will be apparent from the following description when read in conjunction with the appended claims and attached drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a digital audio transmission system according to the present invention.
FIG. 2 is a representation of a digital audio framing system according to the present invention.
FIG. 3 is a simplified block diagram illustrating a zero check system according to the present invention.
FIG. 4 is a block diagram of a zero check and parity generation circuit for the system according to the present invention.
FIG. 5 is a block diagram of a time division multiplexer and FIFO buffer for the system according to the present invention.
FIG. 6 is a block diagram of an encoder and output circuit for the system according to the present invention.
FIG. 7 is a block diagram of a command generator circuit for the transmitter portion of the system according to the present invention.
FIG. 8 is a block diagram of a clock circuit for the transmitter portion of the system according to the present invention.
FIG. 9 is a simplified block diagram of a clock circuit for the receiver portion of the system according to the present invention.
FIG. 10 is a block diagram of the clock circuit and a command generation circuit of the receiver portion of the system according to the present invention.
FIG. 11 is a block diagram of a data latch and parity check circuit for the system according to the present invention.
FIG. 12 is a block diagram of smoothing circuit for the system according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 a digital audio transmission system is shown having two channels of analog input data, such as the left and right channels of stereo audio. The analog input data is amplified by respective input amplifiers 10, 12 and filtered by respective passband filters 14, 16. The resulting signal is then sampled by respective sample and hold circuits 18, 20 at a rate f s which is some high frequency, preferably greater than 40 kHz. The sampling frequency f s may be determined by examining the following relationship:
f.sub.s =(1.544Mb/s-8kb/s)/2*(16+1)
producing an upper bound of 45.1765 kHz where 1.544Mb/s is the DS1 bit rate, 8kb/s is the frame bit rate, and 2*(16+1) is the number of bits for one sample for each channel. To guarantee frame synchronization:
f s =(M*1.544Mb/s)/2*(193 bits/frame)=M*4 kHz
where M is an integer. Thus f s =44 kHz.
The result is that the number of samples per frame is:
NS=2*44kHz/8 kHz=11 samples/frame.
Since there are two types of frames, timing and signaling, there are 22 samples for every two frames with six samples of one channel and five samples of the second channel in the first frame, and five samples of one channel and six samples of the second channel in the second frame. The same information used to differentiate between frame types in the common carrier cross-connect system may be used to determine which samples are to be allocated to which frames.
The sampled analog data from the sample and hold circuits 18, 20 are then digitized by respective analog to digital (A/D) converters 22, 24 with a 16-bit resolution. Each 16-bit sample is checked for all zeros by respective parity and zero check circuits 26, 28 and a parity bit is added. The zero check, as illustrated by FIG. 3, is performed by separating the odd and even bits into two 8-bit words, and if all the bits within a word are zero, setting the least significant bit equal to one. The parity bit is added to provide an error check since the transmission medium has a bit error rate of 10 -6 which equates to 1.5 errors per second at the 1.544 Mb/s DS1 rate. Such errors, if not detected and removed or smoothed, manifest themselves as audible and irritating "pops". Thus, if a parity error is detected at the receiver, an appropriate smoothing algorithm is used to generate a valid data value to replace the erroneous data value.
A multiplexer circuit 30 combines the outputs of the parity and zero check circuits 26, 28 and outputs a series of 8-bit words. These 8-bit words are input to an encoder and framing circuit 32 which converts the digital words into a pulse sequence for transmission over the common carrier cross-connect.
At the receiver the pulse sequence is input to a clock and control circuit 34 which generates a clock signal from the received sequence and passes the data with the clock signal to a decoder and framing circuit 36. The decoder and framing circuit 36 restores the 8-bit data word string, with each word being stored in a data latch 38 until a full sample of 16 bits is obtained together with the appropriate parity bit. Parity is tested and, if parity is valid, the sample is passed on to a digital to analog (D/A) converter 40. If parity is invalid, the prior sample for that channel is passed again to the D/A converter 40 and the invalid sample is dropped. Alternatively the prior valid sample and the next valid sample may be averaged or digitally filtered to provide an interpolated sample to replace the invalid sample. The output of the D/A converter 40 is separated into separate analog channels by the sample frequency f s , which channels are amplified, filtered and converted into a balanced output to recover the original, transmitted digital audio signal.
The 16-bit samples are separated into 8-bit words having exclusively even or odd bits, which words are checked for all zeros by the parity and zero check circuits 26, 28. The words from the two channels are put into a master frame as shown in FIG. 2. The first subframe is a timing frame having a single timing bit F t followed by twenty-four 8-bit words. The first word has parity bits for the first six samples and is followed by twelve words having respectively an odd bits 8-bit word and an even bits 8-bit word for channel one succeeded by an odd bits 8-bit word and an even bits 8-bit word for channel two, alternating between the two channels. Word fourteen contains the remaining five parity bits, followed by alternating samples from channels one and two as above. The last sample in the timing frame is from channel one. The next subframe, the signal frame, has a single signal bit F s also followed by twenty-four 8-bit words. The configuration of this subframe is the same as the first subframe except that the first sample is from channel two.
The parity generator and zero check circuit 26, 28 is shown in greater detail in FIG. 4. The separated bits are input into respective odd and even zero comparators 42, 44 which output a signal if all the inputs are zero. This zero signal is combined with the least significant bit of the group by an exclusive OR gate 46, 48 which passes the value of that bit directly on to the next stage in the absence of a zero signal, or sets that bit to one in the next stage if a zero signal is present. The seven most significant bits are input to a parity generation circuit 50 and to a data latch 52 together with the least significant bits from the exclusive OR gates 46, 48. The parity generation circuit 50 outputs a parity bit for the 16-bit sample which is input to a command generation circuit 62 shown in FIG. 7.
The data latch 52 is clocked into a first in-first out (FIFO) buffer/latch circuit 54 together with the corresponding data from the second channel as shown in FIG. 5. Since there are thirty-two bits of input data which is output eight bits at a time, the data is stored at one rate and transferred to the latch portion at a second rate, which rates are related to f s . Enable, load and read commands from the command generation circuit 62 transfer the data from the buffer portion to the latch portion of the buffer/latch circuit 54, and thence to a multiplexer circuit 56. The parity bits are accumulated by the command generation circuit 62, loaded into a parity buffer 58, transferred to a parity latch 60 and thence output to the multiplexer 56 according to appropriate enable, load and read commands. According to the word number as shown in FIG. 2 the multiplexer 56 outputs either a parity word or data words. The output from the multiplexer circuit 30 is a series of 8-bit words containing either data or parity bits.
These words are input to an encoder 64 where the master frame, as shown in FIG. 2, is compiled. The data is converted into a serial unipolar, two output data stream and input to an output driver 66. The output driver 66 is clocked at the 1.544Mb/s rate and outputs a bipolar signal to the common carrier cross-connect for transmission over the telephone network. The encoder 64 also outputs SYNC at 8 kHz, DATARD to read the next data word into the encoder, and FRTYPE to identify the type of frame (timing or signal) to the command generator circuit 62.
The clock and command generation is illustrated in FIGS. 7 and 8. The SYNC from the encoder 64 is input to a phase detector 68 and compared with a phase locked loop 8 kHz signal. The output of the phase detector 68 passes through a loop filter 70 and controls the frequency of a voltage controlled crystal oscillator 72 having a nominal frequency of 5.632 MHz from which the sampling frequency f s is derived. The output of the VCXO 72 is input to a clock generator 74 which provides the phase locked loop 8 kHz signal for the phase detector 68 as well as the clock signals for the other circuitry of the system including the command generation circuit 62. The command generation circuit 62 receives signals from the parity generation circuit 50, the encoder 64 and a clock generator 76 and outputs appropriate commands including the sampling frequency f s and the accumulated parity bits. The clock circuit 76 is synchronized with an external 1.544 MHz source which is converted to a return to zero signal and compared with a clock generated 1.544 MHz signal in a phase detector 78. The output of the phase detector 78 is filtered and used to control a VCXO 80 having a nominal frequency of 6.176 MHz. A clock generator 82 provides the 1.544 MHz signal and a 3.088 MHz signal to synchronize the command generation circuit 62.
At the receiver the balanced input is transformed to return to zero data (RZ) and input to a clock and control circuit 34. The clock and control circuit 34 synchronizes an internal clock with the 8 kHz frame bits to generate the clock required for the receiver. The data and the clock are input to a decode and framing circuit 36 where the data is extracted in the form of the originally transmitted 8-bit words. The 8-bit words are stored in a data latch and parity check circuit 38 where the samples are reconstructed with the appropriate parity bit to assure that there is no transmission error. The 16-bit samples are forwarded to a digital to analog converter 40 where the samples are converted to the original analog signals which are separated into the two separate channels by f s , amplified, filtered and converted to a balanced output.
As shown in FIG. 9 the received data at 1.544Mb/s is input to a phase locked loop tank circuit (LC) oscillator 90 to generate the necessary synchronization and clock signals corresponding to the data rate 1.544 MHz, the sample rate 44 kHz, and the frame rate 8 kHz by the use of appropriate dividers 92, 94 and a second phase locked loop voltage controlled crystal oscillator 96. The clock and control circuit 34 is shown in still greater detail in FIG. 10. A threshold detect and slicer circuit 100 converts the data received from the common carrier cross-connect at the 1.544 Mb/s rate into return to zero data which is input to a decoder 120 and to a first phase detector 102. The phase detector 102 compares the input data rate with a clock generated internal 1.544 MHz signal and outputs an output control voltage which is filtered and used to control an LC oscillator 104 having a nominal frequency of 6.176 MHz. A clock generator circuit 106 provides the internal 1.544 MHz signal and a 3.088 MHz sync signal for the second phase locked loop 96. A second phase detector 108 compares an internally generated 8 kHz signal with a SYNC signal at 8 kHz from the decoder 120, and controls a VCXO 110 having a nominal frequency of 5.632 MHz. The data and the 1.544 MHz clock are input to the decoder 120 which outputs the 8-bits. reconstructed words as shown in FIG. 2 as well as synchronization information derived from the frame bits of the data.
FIG. 11 illustrates the processing of the 8-bit words decoded by the decoder 120. The timing information derived from the frame bits, F t and F s , are input to the control and clock generation circuit 34 at a 8 kHz rate which is used to phase lock the VCXO circuit 96 as described above. The parity words are shifted into a parity latch 122 upon command from the control and clock generator circuit 34 which keeps track of the frame type and word count based upon the timing information received from the decoder 120. The data words are alternately input to odd and even data latches 124, 126 according to gate enable commands from the control and clock generator circuit 34. The 3.088 MHz clock is used to load the data into the latches. The data words from the data latches 124, 126 together with the appropriate parity bit shifted out from the parity latch 122 are input to a parity detect circuit 128. The parity detect circuit 128 outputs a signal to a FIFO buffer 130 to which the reconstructed 16-bit sample is also input. These seventeen bits are shifted into the buffer 130 upon command. A subsequent shift out command transfers the data at the input to the output of the buffer if parity is correct, or is inhibited so the data is not shifted out when a parity error is detected, i.e., the prior sample is still output from the D/A converter 40 when a parity error is detected. The output of the buffer is input to the D/A converter 40 to recover the original analog signal, and subsequently sampled to recover the two channels of data from the analog data stream, filtered and converted to a balanced output as described above.
FIG. 12 shows a technique for replacing a current invalid sample as determined by a parity error with an interpolated valid sample which is the average of the prior valid sample and the next sample. The output of the FIFO buffer 130 is input to a first latch 132, which typically is of the D-type, and to an adder 134. The output of the latch 132 is the current sample while the input is the next sample. The current sample is input to a multiplexer 136. The other input of the multiplexer 136 is the output of a divide-by-two circuit 138, which is typically a shift register. The input to the divide-by-two circuit 138 is the output of the adder 134. The multiplexer 136 is controlled by a parity error signal from the control and clock generator circuit 34. The output of the multiplexer 136 is input to a second latch 140, similar to the first latch 132, the output of the second latch being the prior sample. Both latches are clocked by the sample frequency f s . When there is no parity error the current sample is passed by the multiplexer 136 from the first latch 132 to the second latch 140. When a parity error is detected the parity error signal causes the multiplexer 136 to pass the averaged sample, which is the sum of the prior sample and the next sample divided by two, from the divide-by-two circuit 138 to the second latch 140. Thus the sample sequence becomes prior sample/averaged sample/next sample in lieu of prior sample/current sample/next sample.
Thus, the present invention provides a high precision digital audio transmission system which is compatible with the standards of the common communication carriers by converting the audio to digital via a high resolution A/D converter, providing a parity check, checking for all zeros to assure a minimum ones percentage and a maximum consecutive zeros limit for the data, and time domain multiplexing the two channels of data into a format compatible with standard common carrier frames. At receipt of the data the two channels of data are reconstructed by decoding the received common carrier frames, reconstructing the digital samples and checking for parity, and converting the digital samples into the two channels of analog data, repeating samples where a parity error is detected rather than outputting an erroneous sample. | A digital audio transmission system which is compatible with common carrier digital hierarchy systems converts two channels of analog data, such as precision stereo audio, into high resolution digital data words sampled at a high frequency. The data words are parity checked with the addition of one bit and divided into odd and even bit words for each channel. The bit words are time domain multiplexed into a common carrier frame with separate words for the parity bits and alternating channel data consisting of an odd and an even bit word. Each bit word is checked for all zeros and modified accordingly to assure that ones density and consecutive zero restraints are achieved. The resulting common carrier frames are transmitted over the appropriate common carrier cross-connects to a receiver which decodes the frames, recovering the bit and parity words. The bit words are recombined into data words and checked for parity. The data words are reconverted to the analog data, with valid data words being substituted for data words having a parity error. The analog data is sampled to divide it into the original two channels, resulting in a high precision recreation of the original analog data. | 7 |
BACKGROUND
[0001] 1. Technical Field
[0002] This invention relates to the field of medical instruments, in particular an ablation device.
[0003] 2. Discussion of Related Art
[0004] Radio frequency ablation (RFA) is a minimally invasive treatment method. Rossi, McGahan et al. first reported in 1990 the use of RFA in ablation of liver tissues of animals. This technique was subsequently used in treatment of human hepatic tumors. Nowadays, RFA technique is widely used in treatment of diseases of various organs in the body. In addition to inactivating tumors, it can also lower tumor load, thus reducing pain and hormone secretion. There are also studies of its use in treating non-neoplastic diseases, such as hypersplenism. Basically, RFA is a kind of thermotherapy on tumors. Its basic principle is the use of heat energy to damage tumor tissues. Radio frequency waves generated by electrodes causes the ions and polar macro-molecules in the surrounding tissues to vibrate, impact on one another and rub against one another, thus generating heat. The tumor region is heated up to an effective treatment temperature range and maintained for a period of time, so as to kill the tumor cells. At the same time, the radio frequency heat effect can realize intravascular coagulation of the surrounding tissues, thus forming a reaction zone, and occluding blood supply to the tumors, thus preventing tumor metastasis.
[0005] Regarding the control of the extent of ablation, there are currently two methods: impedance control and temperature control.
[0006] An electrical resistance of 400-500Ω is usually used in impedance control, but the exact resistance cannot be easily adjusted. Too low a resistance will cause premature ending of ablation and thus incomplete ablation, whereas too high a resistance will easily bring about adhesion of tissues.
[0007] In temperature control, the threshold temperature value is usually set at 125° C., and can easily cause an uneven degree of ablation in parts of the treatment region.
SUMMARY
[0008] It is thus an object of the present invention to provide an ablation device in which the aforesaid shortcomings are mitigated or at least to provide a useful alternative to the trade and public.
[0009] According to the present invention, there is provided an ablation device including a needle with a needle body and a needle head, and at least one positive temperature coefficient (PTC) member in a heat-transferrable relationship with said needle body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Ablation devices according to the present invention will now be described, by way of examples only, with reference to the accompany drawings, in which:
[0011] FIG. 1 is a longitudinal sectional view of a bipolar ablation needle according to a first embodiment of the present invention,
[0012] FIG. 2 is an enlarged view of the encircled part marked I in FIG. 1 , and
[0013] FIG. 3 is a partial longitudinal sectional view of a unipolar ablation needle according to a second embodiment of the present invention.
DETAILED DESCRIPTION
[0014] A Positive Temperature Coefficient (PTC) thermistor is a semiconductor having electrical resistance with good temperature sensitivity. The term “PTC” is usually used for referring to semiconductor devices, parts or components with very large positive temperature coefficients. When exceeding a certain temperature, its electrical resistance will increase step-wise when the temperature increases. The higher the temperature, the higher the electrical resistance.
[0015] The present invention makes use of the characteristics of PTC thermistors to provide a new ablation device.
[0016] As shown in FIGS. 1 and 2 , a bipolar ablation needle, being an ablation device according to a first embodiment of the present invention, includes a solid needle body 1 and a needle head 2 with a pointed end. The device further includes an inner electrically insulating sleeve 3 surrounding and in contact with part of an outer cylindrical surface of the needle body 1 , an electrode sleeve 4 surrounding and in contact with part of an outer cylindrical surface of the inner insulating sleeve 3 , an outer electrically insulating sleeve 5 surrounding and in contact with part of an outer cylindrical surface of the electrode sleeve 4 , an isolating electrically insulating layer 6 surrounding and in contact with part of an outer cylindrical surface of the needle body 1 , and a PTC sleeve 7 surrounding and in contact with part of an outer cylindrical surface of the electrode sleeve 4 . The PTC sleeve 7 is electrically connected with the electrode sleeve 4 , and heat generated by the PTC sleeve 7 may be transferred to the needle body 1 of the ablation needle.
[0017] The needle head 2 and the needle body 1 are integral with each other. The needle head 2 is at one longitudinal end of the needle body 1 , of a diameter larger than that of the needle body 1 , and is sharp. The isolating insulating layer 6 is positioned on the body 1 and next to the needle head 2 . Adjacent a longitudinal end of the isolating insulating layer 6 away from the needle head 2 are provided, starting from the inner most layer, the inner insulating sleeve 3 , the electrode sleeve 4 , the PTC sleeve 7 , and the outer insulating sleeve 5 .
[0018] A stepped portion 8 is formed adjacent a longitudinal end of the isolating insulating layer 6 away from the needle head 2 . The stepped portion 8 is of a diameter smaller than the largest diameter of the electrode sleeve 4 . The PTC sleeve 7 is set inside the stepped portion 8 . It can be seen that, by way of such an arrangement, the PTC sleeve 7 , though not in direct contact with the needle body 1 , surrounds the needle body 1 , such that heat generated by the PTC sleeve 7 may be transferred to the needle body 1 .
[0019] The isolating insulating layer 6 may be made of polytetrafluoroethylene (PTFE). Both the needle body 1 and the needle head 2 may be made of medical-grade 304 stainless steel. Each of the inner insulating sleeve 3 and/or the outer insulating sleeve 5 may be made of a PTFE-based polymer traded under the trade mark TEFLON®. The pointed end of the needle head 2 may be of an angle of between 10° to 20°, and preferably of 14.5°.
[0020] As shown in FIG. 3 , a unipolar ablation needle, being an ablation device according to a second embodiment of the present invention, includes an ablation needle with a hollow needle body and a needle head 9 with a pointed end. A PTC sleeve 10 is received within the interior of the hollow needle body and directly contacts the needle body, such that heat generated by the PTC sleeve 10 may be transferred to the needle body. The PTC sleeve 10 is also partly hollow to receive part of an electrode 11 for establishing electrical contact there-between. An outer insulating sleeve 12 surrounds and is in contact with part of an outer cylindrical surface of the needle body.
[0021] Both the needle body and the needle head 9 (which are integral with each other) of the unipolar ablation needle may be made of medical-grade 304 stainless steel. The outer insulating sleeve 12 may be made of a PTFE-based polymer traded under the trade mark TEFLON®. The pointed end of the needle head 9 may be of an angle of between 10° to 20°, and preferably of 14.5°.
[0022] The PTC sleeves 7 , 10 are distributed with PTC thermistor/material, which may be made of:
(a) nylon-12 (L1940), namely a nylon polymer with the formula [(CH 2 ) 11 C(O)NH] n manufactured by Degussa AG (Germany), (b) superconducting carbon black (with an oil absorption value of 780 cm 3 /100 g) manufactured by Shandong Zibo Carbon Black Factory, and (c) fumed silica (R106) manufactured by China BlueStar Shenyang Chemical Co. Ltd.
[0026] Dried and processed nylon-12, carbon black and fumed silica are mixed and processed in a torque rheometer at a temperature of around 190° C. for about 10 minutes. The thus mixed and processed materials are then conveyed to a mould at a temperature of around 200° C. to form PTC sleeves. The pressure is maintained for 2 minutes and the PTC sleeves are allowed to cool down naturally under room temperature. The resultant sleeves with PTC material/thermistor have an electrical resistance of 1.45×10 −3 Ω at room temperature, and with an electrical resistivity of 1.1×10 −2 Ω cm. The electrical resistance of such PTC sleeves change drastically at around 100° C., with a change of a magnitude of around 1×10 9 . Such PTC sleeves thus have a low electrical resistance at room temperature and a large rate of change of electrical resistance.
[0027] The ablation device according to the present invention makes use of the characteristics of PTC thermistor. In combination with a radio frequency generator, such a device may be specifically used for heat treatment of target biological tissues. Such heat treatment may be carried out within the temperature range of 80° C. to 120° C., and preferably 100° C., such that upon coagulation of the tissues, there is no adhesion of the ablation devices, thus reducing the risk of such complications as bleeding.
[0028] As the PTC thermistor in the present invention is distributed about the entire ablation region, in contrast to existing total cutting-through, an ablation device according to the present invention can achieve partial cutting-through, until all the tissues in the ablation region reach the predetermined ablation temperature, thus realizing precise control of the ablation process, and total and complete ablation of all target tissues. In addition, once the target ablation tissues reach the predetermined temperature, the tissues will be cut, thus avoiding over damage to the tissues.
[0029] It should be understood that the above only illustrates examples whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention.
[0030] It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations. | An ablation needle is disclosed as including a needle body ( 1 ) and a needle head ( 2, 9 ), and a positive temperature coefficient (PTC) sleeve ( 7, 10 ) in a heat-transferrable relationship with the needle body ( 1 ). | 0 |
TECHNICAL FIELD
This invention relates to a method for controlling the operation of one or more pumps and to apparatus for carrying out such a method. Although the present invention will be described herein with particular reference to the operation of electrically controlled pumps in a pumping-station, it is not to be construed as being limited thereto. The method and apparatus of the present invention is applicable to any situation in which pumps are used to remove liquid from a vessel in response to an increase in the level of the liquid within said vessel.
BACKGROUND OF THE INVENTION
A typical pumping-station comprises a plurality of wells or sumps, each well or sump having an inlet to admit liquid thereto and an outlet to remove liquid therefrom. Each outlet is associated with one or more pumps which, in use, transfer the liquid from the well or sump for further processing.
The price of the electricity used to operate the pumps is a significant factor in the cost of running a typical pumping-station. Seasonal (or even daily) variations in tariff costs are implemented by electricity supply companies. It is therefore highly desirable, when operating pumps, to optimise pumping during low-tariff periods and to avoid pumping as much as possible during higher-tariff periods, with the proviso, however, that overflow from the well or pump should if at all possible be avoided.
It may also be required to minimise pumping during certain periods, to avoid noise disturbance caused by the operation of the pumps. For the purpose of the present invention, the period in which it is necessary to avoid the use of the pumps to minimise noise disturbance may be considered to be the same as a higher-tariff period, since the net effect on the operation of the pumps is the same.
Although several methods of controlling the operation of pumps in a pumping-station so as to minimise the consumption of higher-tariff electricity are known (for example GB-B-2298292), such known methods have tended to require a more or less complicated system of plural “on-off” pumping points and/or means to determine the pumping-rate and running-time of each pump used.
SUMMARY OF THE INVENTION
The present invention provides a method of controlling pumps which is based upon the anticipation of a change in the price of the electricity required to operate the pump and which proactively manages the level of the liquid to the optimum, at times of tariff-change.
Accordingly, the present invention provides a method for controlling the operation of one or more electrically-operated pumps to pump a liquid from a well or sump which, in use, receives a substantially continuous inflow of the liquid, wherein the method includes the step of starting or stopping each pump in relation to the approach of a change of tariff for the electricity supplied for the operation of each pump.
Preferably, the method of the present invention includes the steps of providing the customary single set of “start” and “stop” points for the pumps associated with each said well or sump and, before actuating the pumps at the “start” point or stopping the pumps at the “stop” point, determining the time required to empty and subsequently to refill the well or sump at the current inflow rate and comparing said time with the time remaining before said change of tariff.
For example, if the approaching change of tariff is positive (i.e. the cost of the electricity is about to increase), it is desirable to empty the well or sump completely, prior to the change.
Alternatively, if the approaching change of tariff is negative (i.e. the cost of the electricity is about to decrease), it is desirable for the well or sump to be allowed to fill to an increased level immediately prior to the change.
The present invention also provides apparatus for carrying out the method hereinabove described, the apparatus comprising a well or sump which, in use, receives a substantially continuous inflow of a liquid. The well or sump having an outflow for the liquid and one or more electrically operated pumps associated with the outflow. The well or sump is provided with a single set of “start” and “stop” points for the pumps, and further comprising means to determine, at the “start” point and at the “stop” point, the time required to empty and subsequently to refill the well or sump and to compare the time with the time remaining before a change of tariff for the electricity supplied for the operation of each pump.
The present invention will be illustrated, merely by way of example, in the following description and with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a well or sump to which the method of the present invention is to be applied;
FIG. 2 is a schematic representation of change in winter electricity tariffs with respect to time;
FIG. 3 is a schematic representation of change in summer electricity tariffs with respect to time;
FIG. 4 is a typical set-up menu for use in connection with the present invention; and
FIG. 5 is a schematic representation of change in liquid levels with respect to time, as applied to the well or sump shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is shown a sump ( 10 ) having two pumps ( 11 and 12 ) operatively associated therewith.
FIG. 1 shows the points at which a pump is switched on ( 3 ) and switched off ( 1 ). There is also present a “high-level” alarm ( 5 ) which is initiated from the system in the event of high liquid level. Also illustrated in FIG. 1 is the minimum start level ( 2 )—this is the minimum level of liquid required to prime the pumps and enable them successfully to pump out liquid. Level ( 4 ) is a pump on over-ride. This is the level at which, irrespective of the control sequence in operation, the appropriate pumps will be switched on in order to draw down the liquid level. During normal operation, the pump is switched on at level ( 3 ) and off at level ( 1 ). Variation of the sequencing of the pumps may be initiated, within the scope of the present invention.
In this example, we have considered a maximum of three different tariff levels occurring during the period of a typical day in winter and the effect of those levels on the associated supply of electricity to pumps in a pumping-station. For completeness, a corresponding tariff variation (showing only two tariff periods) is also shown illustrating a typical summer day (or alternatively a noise-avoidance period, which may be required at any time of year).
Referring to FIGS. 2 and 3, periods A-C and K-A are the lowest cost tariff periods (X). Periods D-J (summer), D-F and I-J (winter) illustrate the next highest rate of tariff charge (Y) and periods G-H illustrate the highest tariff period (Z) which may represent a substantially higher cost of electricity, and which is sometimes called a triad period.
The tariff periods are programmed into a PULSAR level-control unit by means of a set-up menu as shown in FIG. 4 . The unit monitors a period of 48 hours in advance of the current time registered on its internal real time clock and a period of 24 hours in arrears of that time. If no changes in tariff occur during this monitored period, the pumps operate in the normal way between levels ( 1 ) and ( 3 ). If, however, there is to be a change in tariff cost (as illustrated by C-D, F-G, H-I, J-K) during the next 48-hour period, the unit causes the pumps to operate in the following manner:
At the end of each pumping cycle, the pumps are switched off. The inflow to the sump then causes the liquid level to rise. The volume of inflow of liquid to the sump is then determined and compared to the capacity of the sump to contain the inflow of liquid that will occur between the determination time and the time at which the next tariff change will occur. The unit will then operate the pumps according to one of the following three options, with the proviso that in no circumstances will a pump be run unless the level of liquid is above the minimum start level ( 2 ).
Option I: If the capacity of the sump is not sufficient to contain the liquid at the current inflow rate, the pump will pump in the normal way, switching on at 3 and off at 1 . Before actually switching on the pump in this case, the unit will calculate whether there is enough time to refill the well before the next tariff change. This is done by calculating the time required to pump the sump empty to level ( 1 ) and to refill the sump to level ( 3 ), at the current inflow rate. If this time period is in excess of the time required to reach the next tariff change and the capacity of the sump at the required level is sufficient to contain the inflow of liquid that will occur prior to the next tariff change, then instead of pumping the sump down to the empty level ( 1 ) the unit will operate the pumps according to Option II: not switch the pump on at level ( 3 ) but instead store the liquid within the sump, utilising the full capacity of the sump if necessary. If, however, the capacity of the sump at the required level is not sufficient to contain the liquid inflow that will occur prior to the next tariff change, the system will operate according to Option III: pump the sump down to a level which provides enough capacity in the sump to contain the liquid inflow that will occur in the period of time remaining before the next tariff change. The time that the pump is run under these circumstances is at least equal to or longer than the minimum pump run time. (The minimum pump run time is the time designated as the minimum time it is desirable for any pump to run—this will vary according to the type of pump design, is user definable and is used to prevent excessive wear and tear to the pump or to prevent pump(s) from hunting.)
These sequences are illustrated in the plot of level against time as shown in FIG. 5, viewed in conjunction with FIG. 1 and FIG. 2 .
First Positive Tariff Changes
If the next tariff change is positive, i.e. the tariff charge increases, it is desirable to empty the sump completely prior to the increase in tariff rate, thus providing maximum storage capacity available to be filled by the inflow during the higher tariff period. Therefore, in anticipating this positive change in tariff, a point in time illustrated for example as B or E on FIG. 2, can be determined. This is the point in time at which the level must be optimised to be at the pump start level 3 or at least above the minimum pump start level ( 2 ) and thus provides enough time, B-C or E-F, to allow the well to be pumped completely empty prior to the positive tariff change to a higher cost. In the case of the first positive tariff change this situation is achieved utilising Option I or Option III described above. The periods B-C and E-F are called the pump “lead times”. During this period pump 1 will be switched on whilst the level is at any point between level ( 2 ) (minimum start level) and level ( 3 ) (pump on level) and the sump emptied. All other pumps will operate at their normal start and stop points during the pump lead-time.
If the level in the sump were not optimised to the pump start level ( 3 ) at B or E it might be that there is not enough liquid within the sump to achieve the minimum pump start level and therefore enable the system to commence pumping to achieve an empty sump prior to the positive tariff change in this manner. The system therefore ensures that at points D and G the higher tariff is commenced with a completely empty sump.
Subsequent Positive Tariff Changes
For subsequent positive tariff changes the system optimises the level to be at any point above (2) the minimum start level at the commencement of the pump lead time and may use the full capacity of the sump employing Options I, II or III.
Negative Tariff Changes
Conversely at negative tariff changes, illustrated on FIG. 2 at points H and J, it is desirable, since the cost of electricity is falling rather than increasing, to have a full sump ready to be pumped out at lower cost after the change to a lower tariff level H-J or J-K has occurred. In this case the system optimises the contents of the sump by utilising Options II or III described above and using the extra capacity between levels ( 3 ) and ( 4 ), calculated from the liquid inflow such that, at points H and J a full sump is achieved and maximum saving is made by emptying at a lower tariff after the electricity cost reduction has occurred.
Once a negative tariff change has occurred the system will continually assess the level and the inflow rate and calculate if the capacity of the sump is great enough to contain the liquid inflow until even the next lower tariff. If enough capacity is available it will continue to reassess the situation but postpone pumping until any or the final subsequent lower tariff band is reached.
If during any tariff period the rate of inflow changes substantially and unexpectedly, for instance during storm conditions, such that the capacity of the sump will be exceeded and high alarm activated, the sequence of pump operation is placed on override as soon as level 4 is predicted and confirmed to be exceeded, the sump is then pumped down to the normal pump off points.
Whenever the lowest tariff band is reached the system will resume normal running and a period of time called the pump lag time is implemented. This period is initiated immediately after a lower tariff period has been commenced and in the event that pumping down from a level in excess of the normal start point ( 3 ) is required. During the duration of the pump lag time or until the sump has emptied to the off point ( 1 ) only one pump is allowed to be switched on thus keeping pumping costs to a minimum. However, if the liquid inflow is unusually high and the level is still above the pump start point ( 3 ) after the expiry of the pump lag time, further pumps will be switched on as required by their normal individual start level programs.
Although preferred embodiments of the invention have been described herein, various modifications or variations will be apparent to one skilled in the art without departing from the principles and teachings herein. Accordingly, the invention is not to be limited to the specific embodiments illustrated, but is only intended to be limited by the scope of the appended claims. | A method for controlling the operation of one or more electrically-operated pumps ( 11, 12 ) to pump a liquid from a well or sump ( 10 ) which, in use, receives a substantially continuous inflow of said liquid, characterized in that the method includes the step of starting or stopping each pump in relation to the approach of a change of tariff for the electricity supplied for the operation of each said pump ( 11, 12 ). | 5 |
FIELD
This disclosure is directed to, inter alia, methods for fabricating semiconductor integrated circuits and other micro-electronic devices. More specifically, the disclosure pertains to methods for mounting a semiconductor “chip,” or “die,” to a substrate in a manner that provides physical support for the chip and facilitates the formation of electrical connections to and from the chip, via the substrate, to interconnect the chip to other chips and/or to other micro-electronic circuits.
BACKGROUND
Chip packaging is normally the final process in the long chain of processes for manufacturing semiconductor integrated circuits. Chip packaging is a multi-disciplinary technology that typically involves many steps. The technology is critically important because it has a direct impact on chip performance and reliability as well as the performance and reliability of electronic devices in which the chips are incorporated. “Packaging” as used herein encompasses any of various conventional techniques of preparing a chip (also called a “die”) for actual use in an electronic device. In many instances, packaging involves, basically, encapsulating the die in a manner that seals and protects the die from the external environment and provides the required external electrical connections (called “I/O” connections) from the die to other circuitry. Packaging also can facilitate the conduction of heat away from the die during use. Other types of packaging may simply involve mounting the die on a substrate or carrier, with which the die makes the required I/O connections, without forming a discrete capsule around the individual die beforehand. Since die encapsulation consumes space, this latter packaging method is typically used in applications in which size is critical, such as electronic watches, hearing aids and other medical devices, cellular phones and other personal communication equipment, lap-top and palm-top personal computers, and high-speed microprocessors.
The current disclosure is directed in general to the physical and electrical attachment of a die to a substrate. The electrical connections provide at least some of the required I/O connections of the die to the world outside the die.
Wire bonding has, for many years, been a “workhorse” technology for making electrical connections between I/O bond-pads on the die and I/O bond-pads on the package or other die-mounting substrate. However, wire bonding has several disadvantages. First, it typically is performed serially, pad-by-pad, which is inherently slow and thus decreases throughput. Second, as the number of I/O connections to an integrated circuit (e.g., memory or microprocessor chip) has increased, increasingly larger numbers of I/O bond-pads on the die are required. Providing a larger number of such pads without excessively increasing the size of the chip usually requires a corresponding decrease in the pitch (i.e., a finer pitch) of I/O bond-pads on the die. These factors, as well as other factors, have increased the difficulty and decreased the reliability of using wire bonds, which has led to much interest in alternative methods of making I/O connections to individual dies.
Key alternative methods are derived from the so-called “flip-chip” technology. Flip-chip involves the assembly of a die to a substrate or carrier in a face-down manner, usually by using electrically conductive “bumps” formed on the I/O bond-pads of the die. (“Face-down” means that the die surface on which the circuit layers are formed actually faces the substrate to which the die is attached. Wire-bonding, in contrast, is performed on face-up dies). Flip-chip methods made their debut in the mid-1960s but did not achieve widespread utilization for many years largely because wire-bonding was the norm. With the advent of extremely complex integrated circuits requiring large numbers of I/O connections, flip-chip methods have become attractive. Currently, flip-chip components are predominantly semiconductor devices such as integrated circuits, memories, signal processors, and microprocessors; however, flip-chip methods are also being used increasingly with other types of micro-electronic devices as well, such as passive filters, detector arrays, and MEMs devices. Flip-chip is also termed “direct chip attach” (abbreviated DCA), which is perhaps a more descriptive term because the die is attached directly to the substrate, carrier, or the like by the conductive bumps. DCA has allowed, in many instances, elimination of a conventional “package” entirely.
Among the various conventional flip-chip methods, the most common technique is the “solder-bump” technique that forms a small, individual solder bumps (typically roughly spherical in shape) on the I/O bond-pads of the die. After formation of the solder bumps, the wafer is diced into “bumped dies.” An individual bumped die is placed on a substrate or carrier (generally termed a “substrate”), with the “active” surface (on which the circuit layers were formed) of the die facing the substrate. The assembly is heated to cause the solder bumps to form solder connections between the die and the I/O bond-pads on the substrate. After forming these solder bridges, “underfill” (usually an epoxy adhesive) typically is added between the die and the substrate.
In flip-chip methods, due in part to the substantially shortened pathways of the I/O interconnections of the die with the substrate, increases in operational speed of the dies in finished micro-electronic devices have been realized. This increase in speed has unfortunately resulted in increased heat production by the die. To avoid thermal damage to the die, the heat must be removed in some manner. Some flip-chip circuits achieve heat removal by simple conduction from the die to the substrate and beyond. Whereas this method is satisfactory for some dies, it has limitations for other dies, especially large and complex dies configured for high-speed use. In addition, the substrate and die typically have substantially different coefficients of thermal expansion, which can result in concentration of large stresses on the die between the substrate and/or the solder bumps, especially after repeated thermal cycles. These stresses can result in physical damage to the die, the substrate, and/or the solder interconnections between the two.
A conventional way in which to improve heat conduction from a flip-chip die is to attach a heat-sink or “heat-spreader” (also called an “H/spreader”) to the upward-facing back-side of the die. One conventional method for doing this is shown in FIG. 7 , in which the left-hand portion of the figure is a block diagram of the method, and the right-hand portion of the figure depicts the results of the respective steps. In the first step 10 (stiffener attach & spot cure) a stiffener “ring” 12 is attached to the substrate 14 using an adhesive 16 . The adhesive is “spot cured,” by which is meant a curing stimulus (e.g., heat or radiation) is generally applied only to the adhesive 16 and not elsewhere on the structure. Other features shown in the top right-hand diagram are the die 18 (with active surface facing downward) connected by smaller solder balls 22 to the upper surface of the substrate 14 ; larger solder balls 24 intended to connect the substrate later to other structure (not shown), and underfill 26 . The depicted structure is referred in the art as a “flip-chip ball grid array,” abbreviated “fcBGA.” In the next step 20 (adhesive dispense), an adhesive 28 is applied to the top surfaces of the stiffener ring 12 . In the next step 30 (TIM dispense), before the adhesive 28 is cured, thermally conductive adhesive (also called a “thermal-interface material” or “TIM”) 32 is applied to the upward-facing (“top”) surface of the die 18 . In the next step 40 (H/spreader attach), the heat-spreader 34 is placed on the TIM 32 and on the adhesive 28 . In the last step 50 (press & cure), downward pressure is exerted on the heat-spreader 34 , and the adhesive 28 is cured. (Note that the respective layer thicknesses of the TIM 32 and adhesive 28 are less in the figure corresponding to step 50 than in the figure corresponding to step 40 .)
A larger image of the result of step 50 is shown in FIG. 8(A) , in which also can be seen a “lower” conductive layer 36 providing I/O bond-pads (not detailed) for the larger solder balls 24 on the lower surface of the substrate 14 , an “upper” conductive layer 38 providing I/O bond-pads (not detailed) for the smaller solder balls 22 , vias 42 connecting the upper conductive layer 38 to the lower conductive layer 36 , and the core material 44 of the substrate 14 . In FIG. 8(A) the heat-spreader 34 is substantially planar (called a “Type I” heat-spreader), and is desirably attached to the substrate 14 using the stiffener ring 12 . In FIG. 8(B) the heat-spreader 34 a has an inverted-U profile (called a “Type II” heat-spreader, which allows its attachment to the substrate 14 using the adhesive 28 but without using the stiffener ring 12 .
Another approach is disclosed in published U.S. Patent Application No. 2004/0229399 A1, incorporated herein by reference. In the '399 application, after flipping the die and attaching its solder bumps (on the active surface of the die) to the substrate, the heat-spreader is mounted to the back-side of the die using a TIM. Specifically, a dollop of TIM is applied to the back-side of the die, followed by press-placement of the heat-spreader on the dollop. The resulting bond-line thickness of the TIM depends on the particular TIM material (e.g., viscosity and pot-life) and the applied pressing force. A stiffener ring surrounding the die on the substrate can be used to provide further mechanical support for the heat-sink. If required, the TIM can be treated (e.g., cured) to facilitate adhesion of the heat-spreader to the die. Then, underfill material (epoxy resin) is applied at least to fill the space between the substrate and the die. For application of the underfill resin, the heat-spreader defines at least one through-hole through which the resin is introduced. Sufficient epoxy resin can be added not only to fill the space between the substrate and the active surface of the die but also to form an epoxy fillet around the edge of the die from the substrate to the heat-spreader. Then, the underfill adhesive is cured.
Unfortunately, the conventional methods summarized above exhibit some adverse characteristics. First, for example in the '399 application, the manner of attaching the heat-spreader to the die, namely by applying a dollop of TIM to the back-side of the die followed by press-placement of the heat-spreader onto the dollop, often entraps significant amounts of air, resulting in formation of air voids between the TIM and the heat-spreader and/or between the back-side of the die and the TIM. This entrapped air is not visible externally, is easily entrapped, and is difficult to expel, especially in automated processes. Since the rate of thermal conduction through an air void is substantially lower than the rate of thermal conduction through the TIM, the heat-removal effectiveness of the heat-spreader can be seriously compromised by this problem. Also, application of excessive pressure when press-placing the heat-spreader to the dollop of TIM can fracture or otherwise damage the die and/or the solder connections between the die and substrate. In addition, one or more particles becoming entrapped in the TIM can focus stress on the die and cause the die to crack or break. Similar problems are manifest with the other conventional method summarized above and shown in FIG. 7 .
In view of the foregoing, improved methods are needed for mounting heat-spreaders to fcBGA dies.
SUMMARY
The various shortcomings of conventional methods are addressed by methods and devices as disclosed herein.
According to a first aspect, methods are provided for fabricating a flip-chip. An embodiment of such a method comprises mounting a flip-chip, active-surface facing downward, onto a substrate such that a back-side of the flip-chip is facing upward and requisite electrical connections are made between the chip and an upward-facing surface of the substrate. In another step an adhesive is applied to selected regions not occupied by the flip-chip. In another step a heat-spreader is placed so as to contact the applied adhesive without contacting the back-side of the flip-chip, thereby leaving a gap between the heat-spreader and the back-side of the flip-chip. The heat-spreader defines at least one through-hole that, when the heat-spreader is placed, is situated within a perimeter of the flip-chip. In another step the adhesive is cured. In another step a thermal-interface material (TIM) is applied through the at least one through-hole so as to fill the gap with the TIM.
As used herein, “curing,” “cure,” and “cured” are not limited to adhesives or other substances that require a curing stimulus (e.g., heat or radiation) to harden or otherwise form adhesive bonds having sufficient strength. These terms also encompass processes such as “drying,” “setting,” “hardening,” “cooling,” and the like as applied to adhesives and the like that do not require a stimulus. For example, some adhesives spontaneously “harden” or otherwise assume a form that provides the desired state of adhesion.
Any of the method embodiments can further comprise, during the step of mounting the flip-chip onto the substrate, applying an underfill material at least between the active-surface and the substrate.
In any of the method embodiments the step of mounting the flip-chip onto the substrate further can comprise making solder connections between the active-surface of the flip-chip and the substrate.
In any of the method embodiments the step of mounting the flip-chip onto the substrate can further comprise applying solder balls to selected locations on the active surface of the flip-chip to produce a ball-grid array on the active surface, and causing the solder balls to form respective connections to corresponding locations on the upward-facing surface of the substrate.
Any of the method embodiments further can comprise, during the step of curing the adhesive, pressing the heat-spreader toward the back-side of the flip-chip but not contacting the back-side, thereby retaining the gap.
Any of the method embodiments further can comprise, before or after mounting the flip-chip onto the substrate, attaching a stiffener to the substrate at a location outside the perimeter of the chip. The stiffener can be, and desirably is, attached to the substrate using an adhesive. Hence, the step of applying an adhesive to selected regions can comprise applying the adhesive to a top surface of the stiffener attached to the substrate, wherein the step of placing the heat-spreader comprises placing the heat-spreader so as to contact the applied adhesive on the top-surface of the stiffener.
In any of the method embodiments the step of applying an adhesive to selected regions can comprise applying the adhesive to selected regions of the upward-facing surface of the substrate.
According to another aspect, methods are provided for attaching a heat-spreader to a flip-chip. An embodiment of such a method comprises, with respect to a flip-chip that has been mounted, active-surface facing downward, onto an upward-facing surface of a substrate such that a back-side of the flip-chip is facing upward, applying an adhesive to selected regions not occupied by the flip-chip. In another step a heat-spreader is placed so as to contact the applied adhesive without contacting the back-side of the flip-chip, thereby leaving a gap between the heat-spreader and the back-side of the flip-chip. The heat-spreader defines at least one through-hole that, when the heat-spreader is placed, is situated within a perimeter of the flip-chip. In another step the adhesive is cured. In another step a TIM is applied through the at least one through-hole so as to fill the gap with the TIM.
According to another aspect, flip-chips are provided. An embodiment of such a flip-chip comprises a chip comprising a first surface and an active second surface. The flip-chip also comprises a substrate having a first surface and a second surface, wherein the chip is mounted, in a flip-chip manner, onto the substrate such that the active second surface of the chip is facing the first surface of the substrate, and electrical connections are formed between the active second surface of the chip and the first surface of the substrate. The flip-chip also comprises a heat-spreader that defines at least one through hole and that is coupled to the first surface of the chip and to the first surface of the substrate such that the at least one through-hole is situated within a perimeter of the chip and a gap is defined between the chip and the substrate. TIM is situated within the gap so as to form a thermal connection between the chip and the heat-spreader.
In any of the flip-chip embodiments the electrical connections can comprise a ball-grid array.
In any of the flip-chip embodiments the heat-spreader can define multiple through-holes each situated within the perimeter of the chip.
Any of the flip-chip embodiments further can comprise a stiffener situated between and mounted to the first surface of the heat-spreader and the first surface of the substrate outside the perimeter of the chip. Such a flip-chip further can comprise a first adhesive situated between the stiffener and the first surface of the substrate and a second adhesive situated between the stiffener and the heat-spreader. The heat-spreader in these embodiments can be a Type I heat-spreader.
In any of the flip-chip embodiments the stiffener can be coupled directly to the first surface of the substrate using an adhesive. The heat-spreader in these embodiments can be a Type II heat-spreader.
According to yet another aspect, electronic devices are provided that comprises a flip-chip according to any of the embodiments summarized above.
The foregoing and additional features and advantages of the subject methods, and of devices made thereby, will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(A) is a half-tone of a photograph showing air voids in TIM on the die side.
FIG. 1(B) is a half-tone of a photograph showing air voids in TIM on the heat-spreader side.
FIG. 2 provides graphs showing thermal effects of air voids such as shown in FIGS. 1(A) and 1(B) .
FIG. 3 provides, on the left side, a block-diagram flow chart of a representative embodiment of a method for attaching the heat-spreader to the substrate and top surface of the die without pressing the heat-spreader directly onto the die. On the right side are schematic vertical sections depicting the results of respective steps of the method.
FIG. 4(A) depicts, in larger form, the result of step 150 of the method of FIG. 3 , performed with a Type I (planar) heat-spreader.
FIG. 4(B) depicts, in larger form, the result of step 150 of the method of FIG. 3 , performed with a Type II (inverted U-shaped) heat-spreader.
FIG. 5(A) is a side sectional view of a Type I heat-spreader including an exemplary through-hole used in the instant methods.
FIG. 5(B) is a plan view of the heat-spreader in FIG. 5(A) .
FIGS. 5(C)-5(E) are plan views of respective heat-spreaders with different exemplary configurations of through-holes that can be used in the instant methods.
FIG. 6(A) is a side-sectional view of a Type II heat-spreader including an exemplary through-hole used in the instant methods.
FIG. 6(B) is a plan view of the heat-spreader in FIG. 6(A) .
FIGS. 6(C)-6(E) are plan views of respective heat-spreaders with different exemplary configurations of through-holes that can be used in the instant methods.
FIG. 6(F)-6(G) are a side-sectional view and a plan view, respectively, of an alternative configuration to that shown in FIGS. 6(A)-6(B) , wherein the configuration of FIGS. 6(F)-6(G) is “U-shaped” in two dimensions rather than in one dimension as depicted in FIGS. 6(A)-6(B) .
FIG. 7 provides, on the left side, a block-diagram flow chart of a conventional method for attaching the heat-spreader to the substrate and top surface of the die. On the right side are schematic vertical sections depicting the results of respective steps listed on the left.
FIG. 8(A) depicts, in larger form, the result of step 50 of the method of FIG. 7 , performed with a Type I (planar) heat-spreader.
FIG. 8(B) depicts, in larger form, the result of step 50 of the method of FIG. 7 , performed with a Type II (inverted U-shaped) heat-spreader.
DETAILED DESCRIPTION
The subject methods and devices are set forth below in the context of representative embodiments that are not intended to be limiting in any way.
Preliminary Considerations
As discussed above, the conventional methods of attaching a heat-spreader to a flipped-chip ball grid array often results in air bubbles forming or being captured in the TIM. The air can be trapped on the die side of the TIM and/or on the heat-spreader side. Exemplary images of entrapped air in the TIM on the die side and on the heat-spreader side are in FIGS. 1(A)-1(B) , respectively. Note that the entrapped air essentially forms voids in which the TIM is absent. Since the voids conduct heat from the die much more poorly than the TIM, the thermal-conduction efficacy of the TIM is substantially compromised whenever any significant amount of air becomes entrapped in the TIM. If air becomes entrapped on both sides (both the die side and heat-spreader side), then the thermal-conduction efficacy of the TIM is even more compromised. Of course, once the air is entrapped in the TIM, the air tends to remain so. Attempting to purge the air by pressing the heat-spreader toward the die poses a high risk of damaging the die or the substrate or the solder balls on the flip-chip ball grid array (fcBGA).
The results of conventional methods are shown more graphically in FIG. 2 . On the left-hand side of the figure, “material 1 ” can be the die, and “material 2 ” can be the heat-spreader. Note the presence of the TIM between the two materials. This situation has been analyzed as follows. Let R c1 be the contact resistance at the interface of the TIM and material 1 , and let R c2 be the contact resistance at the interface of the TIM and material 2 . Let BLT be the bond-line thickness (wherein the bond-line thickness is controllable, depending upon the TIM material and pressing force applied to the heat-spreader toward the die). The bulk resistance R bulk is expressed as follows:
R bulk = BLT k TIM
wherein k TIM is a factor that depends upon the properties of the TIM. Note that R c1 and R c2 depend upon the trapped-void ratio between the TIM and material 1 and between the TIM and material 2 , respectively. The improved methods disclosed herein are directed to, inter alia, reducing R c1 and R c2 to improve the thermal performance of the heat-spreader on the fcBGA.
Representative Embodiments
The following description may include words of position, such as “up,” “down,”, “upper,” “lower,” “back-side,” “top-side,” “above,” “below,” and the like to facilitate ease of understanding relative positions of things. However, it will be understood that these words are not to be regarded in a strictly limited manner because, by changing the orientation of the structure being referred to, an “upper” surface may become a “lower” surface, for example. The same applies to the claims.
A representative embodiment is depicted in FIG. 3 , in which the left-hand side is a block diagram of steps of the method, and the right-hand side depicts the results of the respective steps as performed on an fcBGA. An example of the fcBGA includes an integrated circuit package having a flip-chip. In the first step 110 (stiffener attach & spot cure) a stiffener ring 112 is attached to the substrate 114 using an adhesive 116 . The adhesive is “spot cured,” by which is meant a curing stimulus (e.g., heat or radiation) is applied only to the adhesive 116 and not elsewhere on the structure. Other features shown in the top right-hand diagram are the die 118 (with active surface facing downward) connected by smaller solder balls 122 to the upper surface of the substrate 114 ; larger solder balls 124 intended to connect the substrate to other structure (not shown), and underfill 126 . In the next step 120 (adhesive dispense), an adhesive 128 is applied to the top surfaces of the stiffener ring 112 . In the next step 130 (H/spreader attach), the heat-spreader 134 is placed on the adhesive 128 , leaving a gap 135 between the die 118 and the heat-spreader 134 . Note that the heat-spreader 134 defines at least one through-hole 137 situated over a region of the die 118 . In the next step 140 (press & spot cure), the heat-spreader 134 is pressed lightly toward the die 118 , and the adhesive 128 is cured. (Note that the layer thickness of the adhesive 128 is less in the figure corresponding to the step 140 than in the step 130 , and the gap 135 is narrower in the figure corresponding to step 140 .) The heat-spreader 134 is not pressed so hard as to actually contact the die 118 . In other words, the gap 135 is retained, which prevents any damage to the die 118 or to its solder connections resulting from pressing the heat-spreader 134 onto the die. In the last step 150 (TIM underfill & cure), TIM 132 is introduced via the through-hole to fill the gap 135 . The TIM 132 is introduced at a controlled rate to fill the gap 135 thoroughly without entrapping air or otherwise forming any voids. The volume of applied TIM 132 is also limited to retain the TIM in the gap 135 and thus prevent the TIM from flowing down the edges of the die 118 . If desired, some TIM 132 can remain in the through-hole 137 . After adding the TIM 132 , if the TIM is a type that requires curing for effectiveness, it can be subjected to a curing condition. (Other types of TIM do not require curing.)
The respective materials and specifications of the substrate 114 , the stiffener ring 112 , the adhesive 116 , the die 118 , the solder balls 122 , 124 , the underfill 126 , the adhesive 128 , the TIM 132 , and the heat-spreader 134 are well-known in the art.
A larger image of the result of step 150 is shown in FIG. 4(A) , in which also can be seen a “lower” conductive layer 136 providing I/O bond-pads (not detailed) for the larger solder balls 124 on the lower surface of the substrate 114 , an “upper” conductive layer 138 providing I/O bond-pads (not detailed) for the smaller solder balls 122 , vias 142 connecting the upper conductive layer 138 to the lower conductive layer 136 , and the core material 144 of the substrate 114 . In FIG. 4(A) the heat-spreader 134 is substantially planar “Type I” heat-spreader and is attached to the substrate 114 using the stiffener ring 112 .
In FIG. 4(B) the heat-spreader 134 a has an inverted-U profile characteristic of a Type II heat-spreader, which allows its attachment to the substrate 114 using the adhesive 128 but without having to use the stiffener ring 112 . Thus, referring to the method of FIG. 3 , when attaching a Type II heat-spreader, step 110 can be omitted.
Distinctive advantages of this method include: (a) no direct pressure on the die is needed, so process yield is correspondingly improved because there is less damage to product, and (b) voids in the TIM are prevented, which yields better and more consistent heat dissipation from the die to the heat-spreader.
FIG. 5(A) depicts a side view of an exemplary Type I heat-spreader 134 . A through-hole 137 is shown. A plan view is shown in FIG. 5(B) , which depicts an exemplary longitudinal through-hole (now denoted as item 137 a ). Note the approximate position of the through-hole 137 a relative to the outline of the die 118 situated underneath. The longitudinal through-hole 137 a has a side formed by the heat-spreader 134 that is parallel to the backside and outline of the die 118 . The side of the through-hole 137 a can extend across the entire lateral dimension of the die 118 . Introducing the TIM via the through-hole 137 a to the die 118 allows even and thorough flow of the TIM into the entire gap 135 between the die and the heat-spreader 134 . Whereas FIG. 5(B) depicts one exemplary through-hole, other possible configurations comprise multiple through-holes. For example, FIG. 5(C) depicts an exemplary single L-shaped through-hole 137 b , FIG. 5(D) depicts an example with four smaller round through-holes 137 c , and FIG. 5(E) depicts an example with one longitudinal through-hole 137 d and two smaller round through-holes 137 e.
In an alternative embodiment, FIG. 6(A) depicts a side view of a Type II heat-spreader 134 a . A through-hole 137 is shown. A plan view is shown in FIG. 6(B) , which depicts an exemplary longitudinal through-hole (now denoted as item 137 a ). Note the approximate position of the through-hole 137 a relative to the outline of the die 118 situated underneath. Introducing the TIM via the through-hole 137 a to the die 118 allows even and thorough flow of the TIM into the entire gap 135 between the die and the heat-spreader 134 . Whereas FIG. 6(B) depicts one exemplary through-hole, other possible configurations comprise multiple through-holes. For example, FIG. 6(C) depicts an exemplary single L-shaped through-hole 137 b , FIG. 6(D) depicts an example with four smaller round through-holes 137 c , and FIG. 6(E) depicts an example with one longitudinal through-hole 137 d and two smaller round through-holes 137 e.
FIGS. 6(F)-6(G) are a side-sectional and a plan view, respectively, of an alternative configuration to that shown in FIGS. 6(A)-6(B) . Notably, the configuration of FIGS. 6(F)-6(G) is “U-shaped” in two dimensions (x and y) rather than in one dimension (x or y) as depicted in FIGS. 6(A)-6(B) . The examples shown in FIGS. 6(C)-6(E) are equally applicable to the configuration of FIGS. 6(F)-6(G) as they are to the configuration of FIGS. 6(A)-6(B) .
Whereas the invention has been described in connection with representative embodiments, it is not limited to those embodiments. On the contrary, the invention is intended to encompass all modifications, alternatives, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. | Methods for fabricating flip-chips are disclosed. In an exemplary method, a flip-chip is mounted, active-surface downward, onto a substrate such that a back-side of the flip-chip is facing upward and electrical connections are made between the chip and an upward-facing surface of the substrate. An adhesive is applied to selected regions not occupied by the flip-chip. A heat-spreader is applied to contact the applied adhesive without contacting the back-side of the flip-chip, leaving a gap between the heat-spreader and the back-side of the flip-chip. The heat-spreader defines at least one through-hole that, when the heat-spreader is placed, is within a perimeter of the flip-chip. The adhesive is cured, and a thermal-insulating material (TIM) is applied through the at least one through-hole so as to fill the gap with the TIM. The methods substantially reduce the probability of die damage that otherwise occurs during attachment of heat-spreaders. | 7 |
This present application claims benefit of U.S. Provisional Patent Application Ser. No. 60/575,955, filed Jun. 1, 2004, which application is hereby incorporated by reference herein.
BACKGROUND
The present disclosure relates to body cushioning systems for use in vehicles, and in particular side impact protectors for use by people traveling in vehicles. More particularly, the present disclosure relates to a side impact protector that is wearable by a child traveling in a vehicle.
Juvenile seats are widely used to transport young children in automobiles and other vehicles. Such seats include backless and high back booster seats.
SUMMARY
According to the present disclosure, a side impact protector is configured to be worn by a youth seated in a child-restraint system anchored in place on a vehicle seat. Such a protector may also be worn by a person of any age seated in a vehicle and restrained using a seat belt harness of the type found onboard a vehicle.
Features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description particularly refers to the accompanying figures in which:
FIG. 1 is a perspective view of a wearable side impact protector in accordance with a first embodiment of the present disclosure;
FIG. 2 is a rear elevation view of the protector of FIG. 1 with portions broken away;
FIG. 3 is a perspective view of a child wearing the side impact protector shown in FIGS. 1 and 2 ;
FIG. 4 is a perspective view of the child of FIG. 3 seated in a high back booster seat located in a vehicle equipped with a seat-belt restraint system while wearing the side impact protector of FIGS. 1-3 ;
FIG. 5 is a side elevation view of the high back booster seat of FIG. 4 ;
FIG. 6 is a perspective view of the child of FIG. 3 seated in a backless booster seat located in a vehicle equipped with a seat-belt restraint system while wearing the side impact protector of FIGS. 1-3 ;
FIG. 7 is a perspective view of a wearable side impact protector in accordance with a second embodiment of the present disclosure; and
FIG. 8 is a side elevation view, with portions broken away, of a child seated in a high back booster seat while wearing the side impact protector of FIG. 7 .
DETAILED DESCRIPTION
Side impact protector 10 includes a head cradle 12 , cradle support 14 coupled to head cradle 12 , a waist strap 16 coupled to a lower portion 18 of cradle support 14 , and a shoulder harness 20 coupled to a middle portion 22 of cradle support 14 as shown, for example, in FIGS. 1 and 2 . Cradle support 14 also includes an upper portion 24 coupled to a rear surface 26 of head cradle 12 as shown best in FIG. 2 . Head cradle 12 and cradle support 14 cooperate to form a brace that is adapted to transmit, direct, resist, or support weight or pressure of the head and/or neck of a person wearing side impact protector 10 .
Illustratively, shoulder harness 20 is configured as a first strap and a second strap adapted to be coupled to a wearer, and waist strap 16 is configured as a third strap adapted to be coupled to the wearer. First strap 20 is formed to include loops 21 at end portions of first strap 20 . Loops 21 are configured to receive a portion of second strap 20 therethrough.
Head cradle 12 includes a U-shaped frame 28 formed to include a convex portion providing rear surface 26 and a concave portion 30 facing toward the head of a person wearing side impact protector 10 as shown in FIG. 3 . Head cradle 12 also includes a U-shaped cushion 32 mounted on concave portion 30 to provide padding for the head and neck of the person wearing side impact protector 10 . Head cradle 12 includes side wings 31 to envelope the head of a wearer; however, head cradle 12 is open on the top and front. Illustratively, side wings 31 include a first side wing and a second side wing. A width of head cradle 12 extends from the first side wing 31 to the second side wing 31 and a width of cradle support 14 is less than the width of head cradle 12 .
Waist strap 16 and shoulder harness 20 are used to retain cradle support 14 in place along the back of a wearer as suggested in FIG. 3 . It is within the scope of this disclosure to use a backpack (not shown) in place of waist strap 16 and shoulder harness 20 to retain cradle support 14 in place on a wearer.
Cradle support 14 is sized and shaped to cause head cradle 12 to surround a portion of a wearer's head and neck before and after the wearer is seated in a high back juvenile seat 34 or a backless juvenile seat 36 as suggested, for example, in FIGS. 3-6 . Although not shown, a wearer could sit directly on a vehicle seat 38 and be restrained by a vehicle seat-belt harness 40 while wearing side impact protector 10 without necessarily sitting on a juvenile seat 34 or 36 . Seat-belt harness 40 includes a lap belt 41 and a shoulder belt 42 .
Side impact protector 10 can be used with a car seat having an internal harness system or with a belt-positioning booster seat. Protector 10 can be attached to a wearer via a back pack system or a harness system. Protector 10 can be made of both hard and soft goods such as polyester, nylon, cotton, and polypropylene. As suggested in FIG. 5 , in the case of a high back juvenile seat 34 , a portion of head cradle 12 is located in a space provided between a left side wing 35 and a right side wing 35 of seat 34 when the wearer of side impact protector 10 is seated on seat 34 .
Side impact protector 110 is shown in FIG. 7 . Protector 110 includes a harness mount plate 111 configured to lie along the back of a wearer and carry, for example, a five-point harness 113 including, for example, a waist strap 116 and a shoulder harness 120 . Protector 110 also includes a brace 115 coupled to harness mount plate 111 and adapted to transmit, direct, resist, or support weight or pressure of the head and/or neck of a person wearing side impact protector 110 .
In the illustrated embodiment, harness mount plate 111 is formed to include a spaced-apart pair of slots 144 sized to receive a portion of an automobile belt 146 therein. Automobile belt 146 can thus be used to anchor harness mount plate 111 in a desired position relative to a vehicle seat (i.e., seat 38 ) on which a wearer of protector 110 is seated.
Also in the illustrated embodiment, brace 115 includes a head cradle 112 and a cradle support 114 coupled to head cradle 112 . Head cradle 112 includes a U-shaped frame 128 formed to include a convex portion providing a rear surface 126 and a concave portion 130 facing toward the head of a person wearing side impact protector 110 . Head cradle 112 also includes a U-shaped cushion 132 mounted on concave portion 130 to provide padding for the head and neck of the person wearing side impact protector 110 . Head cradle 112 includes side wings 131 to envelope the head of a wearer; however, head cradle 112 is open on the top and front.
Cradle support 114 is formed monolithically with U-shaped frame 128 in the illustrated embodiment. Cradle support 114 extends downwardly from U-shaped frame 128 to mate with harness mount plate 111 . In the illustrated embodiment, an adjustable head cradle height-adjustment mechanism 148 provides means for mounting cradle support 114 for movement relative to harness mount plate 111 between among several predetermined positions along the length of cradle support 114 so that a user may vary the height of head cradle 112 relative to harness mount plate 111 worn by the wearer of protector 110 .
In the illustrated embodiment, height-adjustment mechanism 148 includes a support guide 150 coupled to harness mount plate 111 and formed to include a channel sized to receive cradle support 114 and allow up-and-down movement in directions 119 and 121 of cradle support 114 therein. Height-adjustment mechanism 148 further includes a retainer 152 mounted for movement on support guide 150 in direction 153 to engage and disengage retainer receivers 154 formed in vertically spaced-apart relation one to another along the length of cradle support 114 as suggested, for example, in FIG. 7 .
With respect to side impact protector 10 , U-shaped frame 28 , concave portion 30 , U-shaped cushion 32 , and first side wing 31 and second side wing 31 associated with the head cradle 12 provide means for enveloping the head of the wearer. First strap 20 , second strap 20 , and third strap 16 also cooperate to form harness means to inhibit movement of the head and a neck of the wearer in response to sudden lateral forces being applied to a torso of the wearer. | A side impact protector is configured to be worn by a youth seated in a child-restraint system anchored in place on a vehicle seat. Such a protector may also be worn by a person of any age seated in a vehicle and restrained using a seat belt harness of the type found onboard a vehicle. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to sampling devices and pumps for the gathering or recovery of liquid samples from groundwater or other liquid bodies.
BACKGROUND OF THE INVENTION
[0002] Submersible pumps, supported by electrical leads and one or more conduits for fluid flow, may be descended into a pre-established well or other water source. The electrical leads provide a means to control the submersible pump, and the liquid conduit provides means to transfer the liquid from the source to the surface for removal or further analysis. A submersible pump of this type is described in U.S. Pat. No. 7,584,785 to Intelisano, the contents of which patent are hereby incorporated by reference.
[0003] One known use of submersible pumps is the testing for, and removal of, contaminants found in liquid bodies. The removal of subsurface contaminants that exist in aquifers and other water sources remains a high national priority. Contaminants of concern span various man-made volatile organic compounds such as chlorinated hydrocarbons and chlorinated olefins (i.e., tetrachloroethylene, trichloroethylene, cis 1,2-dichloroethane and vinyl chloride). Other compounds of interest include, e.g., aromatic or polyaromatic ring compounds such as benzene, toluene, methylbenzene, xylenes, and naphthalene.
[0004] Submersible pumps are subject to potential mechanical failure due to design inefficiencies (e.g., overheating failures related to an inability to effectively dissipate pump heat generation), as well as due to the harsh environmental conditions encountered in subterranean atmospheres (e.g., system strain due to significant turbidity). Maintenance or replacement of the submersible pump assembly can be disruptive as it may cause significant downtime. Moreover, replacement of the entire pumping assembly, typically required upon failure of the pump motor, may be costly.
[0005] Accordingly, there exists a need for a submersible pump for, e.g., groundwater sampling, which is readily serviceable by the quick and convenient removal and replacement of the motor contained therein and for enhanced flow and cooling characteristics around the motor for extended life.
SUMMARY OF THE INVENTION
[0006] Aspects of the present invention relate to submersible pumps for withdrawing water from a water source.
[0007] In accordance with one aspect of the present invention, a replaceable motor module for a groundwater sampling device is disclosed. The replaceable motor module includes an inner housing. The inner housing is defined by a cylindrical shape and has a first alignment pin. A DC-operated electric motor is positionable within the inner housing. The DC-operated electric motor includes a first set of electrical input terminals, an output shaft capable of downwardly extending through a sealed hole in the inner housing, and a first alignment groove capable of mating with the first alignment pin. An inner housing cap including electrical output terminals and a second set of electrical input terminals is pressibly engageable with the inner housing.
[0008] In an exemplary embodiment, a method of assembling a groundwater sampling device is provided. The method includes aligning an alignment groove of an inner housing comprising a DC-operated electric motor within said inner housing, the motor including a first set of electrical input terminals and an output shaft downwardly extending through a sealed hole in the inner housing, with an alignment pin of an inner housing cap comprising a second set of electrical input terminals and electrical output terminals. The method further includes fixedly securing the inner housing to the inner housing cap.
[0009] In another embodiment, a motor module cap for a replaceable motor module for a groundwater sampling device is provided. The motor module cap includes an output cap having a fluid conduit, a first set of lead bores for receiving electrical leads and a first plurality of holes for receiving an equal number of fasteners. A compression disc is substantially annular in shape, and includes a second set of lead bores for receiving electrical leads and a second plurality of holes for affixing the compression disk to the output cap, the second set of lead bores having a diameter equal to or less than the diameter of the first set of lead bores. The compression disc is affixed to the output cap such that the first set of lead bores is in alignment with the second set of lead bores and the first plurality of holes is in alignment with the second plurality of holes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention is best understood from the following detailed description when read in connection with the accompanying drawings, with like elements having the same reference numerals. When a plurality of similar elements are present, a single reference numeral may be assigned to the plurality of similar elements with a small letter designation referring to specific elements. When referring to the elements collectively or to a non-specific one or more of the elements, the small letter designation may be dropped. This emphasizes that according to common practice, the various features of the drawings are not drawn to scale unless otherwise indicated. On the contrary, the dimensions of the various features may be expanded or reduced for clarity. Included in the drawings are the following figures:
[0011] FIG. 1 is a simplified pictorial view of the system of the invention;
[0012] FIG. 2 is a perspective view of a groundwater sampling device and the associated above-ground electrical conduit reel apparatus;
[0013] FIG. 3 is a perspective view of the power booster/controller of the system;
[0014] FIG. 4 is a three dimensional exploded view of an exemplary groundwater sampling device in accordance with aspects of the present invention;
[0015] FIG. 5 is a three dimensional view of a motor module cap for a replaceable motor module for a groundwater sampling device in accordance with aspects of the present invention;
[0016] FIG. 6 is a three dimensional view of a motor module cap for a replaceable motor module for a groundwater sampling device in accordance with aspects of the present invention;
[0017] FIGS. 7A and 7B are three dimensional perspective views of a contact block for a groundwater sampling device in accordance with aspects of the present invention; and
[0018] FIG. 8 is a cross-sectional view of an exemplary groundwater sampling device in accordance with aspects of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The various aspects of the present invention relate generally to a replaceable motor module for a groundwater sampling device. Referring now to the drawings, FIGS. 1 , 2 , and 3 illustrate the basic characteristics of the inventive system, which includes water sampling device 100 in the form of a submersible groundwater pump, an electrical conduit reel apparatus 14 which interconnects a voltage controller/booster device 16 to the water sampling device 100 , and further includes a sample vial 18 into which the groundwater is pumped out of a pre-established well W through water conduit 22 for collection.
[0020] The device 100 is described in more detail below and is positionable within the well W formed into the ground below grade level G. The depth of device 100 is controlled primarily by the feeding of the electrical conduit 20 from reel apparatus 14 . The system voltage/current controller/booster 16 includes a connection to electrical conduit 20 through the attachment of the fitting 32 to the mating fitting 28 connected to reel apparatus 14 . Electrical contacts 34 , which are attachable to the terminals of a low voltage d.c. electrical power source such as a 12-volt battery, provide the power input into controller 16 . By the adjustment of the variable voltage adjuster 36 , which is monitored by the liquid crystal display 38 , voltage output from controller 16 into the motor module contained within device 100 is provided.
[0021] Controller 16 inputs direct current from the 12-volt battery and produces an output voltage to run device 100 within specified parameters. Controller 16 boosts the voltage up to 40 volts and then, using a buck converter, puts out a selected fixed voltage to the pump to operate device 100 at the selected parameters. Consideration is given to the effective wire loss to maximize water output or pressure head that can be pumped.
[0022] When device 100 is activated, groundwater is forced upwardly through flexible conduit 22 , through a disposable valve 24 for dispensing a controlled volume of groundwater into a VOA vial 18 . Alternatively, the system 10 may be used to simply evacuate groundwater from a pre-established well W, in which case the upper end of conduit 22 is directed to discharge the groundwater into, e.g., a suitable container or an above-ground basin. Embodiments of system 10 are currently available commercially through Proactive Environmental Products of Bradenton, Fla.
[0023] Turning next to FIG. 4 , an exemplary groundwater sampling device 100 is provided in more detail. Unless otherwise provided, the components of device 100 are generally formed (e.g., machined and/or molded) of substantially non-corrosive material, such as PVC, polyethylene, polypropylene, ABS, TEFLON® or stainless steel. An outer cylindrical housing 102 formed of such material and having thin walls and a hollow interior includes threads for mating with bottom portion 104 . The mating of outer housing 102 and bottom portion 104 is made water-tight through the incorporation of an o-ring 108 , which is seated on bottom portion 104 . Bottom portion 104 may be formed as a segment sphere (or it may be flat) and includes, at the distal end of bottom portion 104 , a filter screen 106 , which includes one or more inlet ports arranged as shown or in other configurations as would be apparent to one of ordinary skill in the art. Filter screen 106 leads to an interior chamber 110 into which groundwater is drawn.
[0024] Interior chamber 110 is defined by a circumferential ridge 107 on bottom portion 104 . Grooves 105 are arranged on the proximal most edge of circumferential ridge 107 . Circumferential ridge 107 of bottom portion 104 abuts the base 114 of the inner housing 112 . As will be described in greater detail below, grooves 105 permit the flow of fluid from the interior chamber 110 to a clearance gap 125 between inner housing 112 and outer housing 102 .
[0025] Seated within the hollow interior of outer housing 102 is inner housing 112 having a cylindrical tubular shape (i.e., having a hollow interior similar to outer housing 102 ). Base 114 of inner housing 112 includes an opening containing an annular seal 116 . Annular seal 116 receives an output shaft 118 of a d.c. motor 120 upon placement of d.c. motor 120 within inner housing 112 . A water impeller 122 is attached to output shaft 118 and resides, upon assembly, within or above interior chamber 110 and above filter screen 106 . A clearance gap 125 is established between the inner diameter of outer housing 102 and the outer diameter of inner housing 112 to define a water passageway or “jacket” through which fluid can upwardly travel towards an output cap 170 containing a fluid conduit 172 .
[0026] The top of motor 120 includes two electrical input terminals 124 which receive d.c. current and voltage from controller 16 through electrical conduit 20 as will be described in more detail below. A thin plastic disc 127 is fastened to motor 120 by electrical input terminals 124 and acts as a quality control device which indicates tampering with motor 120 . Thin plastic disc 127 also eliminates electrical interference between motor 120 and the output contact blocks 142 .
[0027] Referring back to FIG. 4 , output shaft 118 passes through an annular spacer 126 , which is positioned below the bottom of motor 120 and inside of inner housing 112 . Annular spacer 126 further contains an opening 130 for receiving an alignment pin 128 . Turning briefly to FIG. 8 , alignment pin 128 is fixedly attached to base 114 of inner housing 117 , passes through opening of annular sparer 126 , and is received by an aperture 132 of motor 120 . Alignment pin 128 establishes the proper rotational alignment and immobilization between motor 120 and inner housing 112 . In one embodiment, springs 134 may exert an upward force upon annular spacer 126 to further stabilize motor 120 and to keep electrical inputs 124 in contact with the d.c. power source.
[0028] An inner housing cap 136 may include one or more o-rings 135 (three are shown in FIG. 4 ) positioned at the base (i.e. proximal) portion 138 of inner housing cap 136 . Inner housing cap 136 , forms a water-tight seal with inner housing 112 by way of o-rings 135 after base 138 is inserted into inner housing 112 . Preferably, a proper rotational alignment is established between inner housing cap 136 and inner housing 112 in order to align protrusions 137 on inner housing with receiving gaps 141 . In one embodiment, upon the mating of protrusions 137 with receiving gaps 141 , an inward force applied to protrusions 137 , such as provided by a pneumatic press, engages protrusions 137 with receiving gaps 141 , thereby fixedly attaching inner housing cap 136 to inner housing 112 . Alternatively, protrusions 137 can extend radially towards the longitudinal axis of inner housing 112 such that protrusions 137 snap into receiving gaps 141 .
[0029] The proper rotational alignment between inner housing cap 136 and inner housing 112 may also be established by way of a cap alignment pin 139 , which may be located on base portion 138 , and an inner housing notch 140 , located at the top of inner housing 112 . In one embodiment, cap alignment pin 139 mates with inner housing notch 140 . One of ordinary skill in the art will understand that other arrangements may be used to establish alignment and connection between inner housing 112 and inner housing cap 136 (such as, e.g., reversing the above described embodiment by providing a notch on inner housing cap 136 and an alignment pin at the top of inner housing 112 ).
[0030] Proper rotational alignment permits mechanical and electrical contact between electrical input terminals 124 of d.c. motor 120 and two output contact blocks 142 . Output contact blocks 142 may be seated within slots formed into a non-conductive accurately configured spacer 144 , which itself is held in position inside of base portion 138 by threaded fasteners 143 .
[0031] Input contact blocks 146 may be similarly seated into slots formed into a non-conductive spacer 148 which, as shown in FIG. 4 , may be positioned inside the distal portion of inner housing cap 136 . Electrical and mechanical contact may be established between input contact blocks 146 and output contact blocks 142 by way of an electrical conduit, shown in FIG. 4 as two wire portions 150 .
[0032] Output cap 170 , also formed of machined material, includes outwardly extending pins 174 which lockably engage into L-shaped slots 152 formed into inner housing cap 136 . Following axial movement together with the pins 174 properly aligned with the longitudinal portions of these L-shaped slots 152 , a simple twisting action seals and locks output cap 170 into engagement with the upper end of inner housing cap 136 . Upon reading the teachings contained herein, other manners of attaching output cap 170 and inner housing cap 136 will become apparent to those having ordinary skill in the art.
[0033] Output cap 170 further includes, at a base portion 175 , a plurality of o-rings 177 that allow a water-tight seal between output cap 170 and inner housing cap 136 upon lockably engaging these two components. Within base portion 175 , output contact blocks 176 may be seated within slots formed into a non-conductive accurately configured spacer 178 . Configured spacer 178 is held in position inside of base portion 175 by threaded fasteners 179 . Electrical and mechanical contact between output contact blocks 176 and input contact blocks 146 is established as a result of lockably engaging output cap 170 and inner housing cap 136 .
[0034] At distal portion of output cap 170 , a fluid output passage 184 is a longitudinal passage within output cap 170 which is in fluid communication with fluid conduit 172 . In one embodiment, fluid conduit 172 radially extends from the base of fluid output passage 184 (i.e., fluid flows into fluid conduit 172 in a radial direction towards fluid output passage 184 , at which point the fluid flow is re-directed longitudinally upwards towards the distal portion of output cap 170 ). In FIG. 4 , fluid conduit 172 includes a series of radial passageways which intersect with fluid output passage 184 . Turning briefly to FIG. 5 , an alternative embodiment is shown in which fluid conduit 272 penetrates completely through output cap 270 , forming an “hour glass” shape in which the circumference of the fluid passage (on both sides of output cap 270 ) is gradually restricted until intersecting with fluid output passage 284 at the center point of the hour glass. The hour glass configuration, which is incorporated in, e.g., the SS Mega-Typhoon® and the SS Mini-Monsoon®, available commercially from Proactive Environmental Products of Bradenton, Fla., provides increased head pressure and, accordingly, an increased flow rate. Additionally, this configuration facilitates cleaning this region.
[0035] Returning to FIG. 4 , also at distal portion of output cap 170 , two longitudinal bores 188 provide access to output contact blocks 176 . Electrical conduit 20 , shown specifically in this case as electrical leads 186 , passes through longitudinal bores 188 . Preferably, the ends of electrical leads 186 are stripped of insulation to expose the conductive interior wiring and then affixed (e.g., clamped, soldered, or otherwise mechanically attached) within mating holes formed into output contact blocks 176 . In one embodiment, additional deterrence of fluid flow into bores 188 is accomplished through the use of one or more o-rings positioned around electrical leads 186 . As shown, a configuration having an o-ring 190 above a spacer 192 , which is above a second o-ring 194 , is employed for each lead 186 . Preferably, o-ring 190 , spacer 192 , and second o-ring 194 surround each lead 186 within bores 188 .
[0036] Further ensuring against fluid access to interior electrical components via bores 188 , each contact block (i.e. output contact blocks 176 , input contact blocks 146 , and output contact blocks 142 ) may be machined such that only a partial bore is created for receiving the electrical conduit and for receiving fasteners. That is, in this alternative embodiment of the invention, no contact block contains a bore which passes completely through the contact block. An exemplary contact block incorporating these “partial” bores is shown in FIGS. 7A and 7B . Partial bore 701 receives a lead, which is fastened into place via, e.g., spot welding or a threaded fastener which biases the lead at partial bore 703 . Partial bore 705 receives a threaded fastener (such as, e.g., threaded fastener 143 ), which secures contact block 700 to the overall structure.
[0037] Returning to FIG. 4 , an annular compression disc 196 is fastened to the distal portion of output cap 170 by way of one or more fasteners 195 which penetrate through compression disc 196 and into output cap 170 . Compression disc 196 further includes two longitudinal bores 198 , which have a relatively smaller circumference than longitudinal bores 188 . By this smaller circumference, compression disc 196 compresses o-ring 190 , spacer 192 , and second o-ring 194 within bores 188 . While not intending to be limited to a single theory, it is believed that this arrangement provides a uniform distribution of downward pressure upon d.c. motor 120 , thereby acting as a harmonic balancer by minimizing resonance from the operation of d.c. motor 120 .
[0038] A conduit nipple 199 passes through the annular portion of compression disc 196 and into output cap 170 , threadably mating with threads contained therein. An extension conduit in the form of flexible tubing (not shown) may then be mounted on conduit nipple 199 , thereby obtaining access to fluid output passage 184 . In one embodiment, conduit nipple 199 comprises a single “mushroom head” configuration in which a single circumferential protrusion 201 allows easy removal and fitting of the flexible tubing fluid conduit. Other configurations of conduit nipple 199 are within the grasp of the ordinarily skilled artisan, such as, e.g., multiple circumferential protrusions 20 i (known as a “barb” tip).
[0039] The completed device 100 is assembled, upon locking together output cap 170 and inner housing cap 136 (i.e., after inner housing cap 136 is fixedly attached to inner housing 112 as described above), by threadably engaging threads 180 on output cap 170 with mating threads 103 formed into the upper end of outer housing 102 . One of ordinary skill will appreciate that other means exist to securing output cap 170 to outer housing 102 , including an adaptation of the locking configuration described above for locking output cap 170 to housing cap 136 . One or more o-rings 182 placed on the outer periphery of output cap 170 (e.g., proximal to threads 180 ) creates a water-tight seal with outer housing 102 . By this arrangement, electrical power flows from controller 16 through electrical conduit 20 to output contact blocks 176 , input contact blocks 146 , output contact blocks 142 and, finally, to input terminals 124 , which provides power directly to d.c. motor 120 .
[0040] Fluid passes through filter screen 106 into inner chamber 110 of bottom portion 104 , drawn into the groundwater sampling device by water impeller 122 upon rotation of output shaft 118 by motor 120 . From the inner chamber 110 , fluid passes through grooves 105 , advantageously increasing the pressure of the fluid stream, and into a clearance gap 125 . Clearance gap 125 is established by diameter selection between the inner diameter of outer housing 102 and the outer diameter of inner housing 112 . Clearance gap 125 defines a water passage which upwardly receives groundwater in the direction of the arrows towards output cap 170 and fluid conduit 172 . Water drawn in this fashion will proceed through conduit nipple 199 to attached flexible tubing leading to the surface (not shown).
[0041] Simple replacement of d.c. motor 120 may be accomplished by: a) unscrewing output cap 170 from outer housing 102 ; b) removing impeller 122 from output shaft 118 ; c) unlocking (by twisting, and then pulling) output cap 170 from inner housing cap 136 ; and d) the disposable sub-assembly includes inner housing cap 136 fixedly attached to inner housing 112 (which includes, inter a/ia, the spent d.c. motor 120 ). The procedure is reversed to install the new sub-assembly containing a new d.c. motor 120 .
[0042] Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention. | A replaceable motor module for a groundwater sampling device including an inner housing defined by a cylindrical shape and having a first alignment pin. A DC-operated electric motor is positionable within the inner housing, and includes a first set of electrical input terminals, an output shaft capable of downwardly extending through a sealed hole in the inner housing, and a first alignment groove for mating with the first alignment pin of the inner housing. An inner housing cap includes a second set of electrical input terminals and electrical output terminals, and is pressingly engageable with the inner housing. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Application No. 61/253,920, filed Oct. 22, 2009, and incorporated herein by reference.
FIELD OF THE INVENTION
The present invention generally relates to a portable transceiver device that can facilitate one or more local computing devices accessing the same subscriber-based network by sharing and/or switching access privileges.
BACKGROUND OF THE INVENTION
With the increasing popularity of modern data communications devices, also referred to herein as personal computing devices (PCDs), such as cellular phones, personal desktop assistants (PDAs), tablet computers, netbook computers, laptop computers, electronic book devices, media player devices, video-gaming units, digital cameras, video recorders, etc., many consumers are creating a high demand for new technologies that enhance the mobility and flexibility of wireless services that facilitate network communications for their PCDs. Only a minority of consumers today is able to replace their wireless-capable PCDs (e.g., their cell phone or tablet computing devices) every time a new or more popular device model (having improved features and functionality) becomes available. Most consumers prefer to simply upgrade or enhance their existing PCDs for a period of time, by updating operating system firmware, adding new software applications, and/or purchasing auxiliary compatible aftermarket hardware components, such as: external or plug-in memory components, wireless modems, media card readers, GPS units, auxiliary microphone and/or speaker devices, webcams, etc.
One relatively new technology that some consumers utilize to enhance the data communications capability of their existing PCDs is known in the Art as device “tethering.” By way of example, the Apple® iPhone™ (e.g., 112 b of FIG. 1 ), as well as many Google® Android™ based phones (e.g., Motorolla®, HTC®, or Samsung® phones running the Android® operating system), have been advertised to have tethering software and functionality that enables these devices to act as a data communications modem and/or gateway for a separate PCD, such as a laptop computer (e.g., 112 a of FIG. 1 ). In a scenario where a user of a PCD is lacking access to the Internet via a wireless network service (e.g., a cellular or a WiMAX network), a phone (having such network access) can be tethered or otherwise coupled to the PCD to allow the PCD to gain access to the cell phone user's subscribed network service (e.g., a subscribed cellular service provided by AT&T®, Sprint®, Verizon®, T-Mobile®, etc.).
As would be understood by those skilled in the art, tethering generally facilitates a first stand-alone computing device (e.g., a laptop or mini-computer), not having a desired network access at a particular time or location, to utilize a second stand-alone computing device (e.g., a cellular phone or PDA having a desired network service) as an external modem and/or gateway to provide the PCD with linked access to the desired network services (e.g., broadband access to the Internet). In this scenario, a tethered device (See e.g., cellular phone 112 b ) acts as a burdened, slave device for a master tetheree device (See e.g., laptop computer 112 a ). As would be understood by those skilled in the art, a master-slave model in data communications occurs when a master, controller device or process has unidirectional control over one or more slave device components. Generally, a tethered (slave) device is not designed to function independently of a tetheree (or master) device, while the two devices are paired in a routed data communications session. This is due to the fact that a significant amount of the tethered device's data processing and communications capability, along with its power and memory resources, are actively being consumed to facilitate the tetheree device's communications to a proprietary network service that is associated with the tethered device. In most scenarios, the tethered device's user interface is not accessible or practically available to its user during tethering, nor is its communications functionality.
Tethering scenarios that facilitate sharing access to a subscriber-based proprietary network typically require utilization of a subscriber identification module (SIM), or some other imbedded identity module, to authenticate the identity of a network service subscriber attempting to access the proprietary network. In other scenarios, tethering may not require use of a subscriber's SIM to access other types of data communications networks (e.g., some public Wireless Local Area Networks or WLANs). By way of example, if a user's PCD is not equipped with a transceiver allowing the PCD to access a public WiFi™ network (e.g., broadband access to the Internet not requiring secure account authentication), the PCD may be tethered to a cellular phone or PDA having a WiFi™ transceiver, to allow the PCD to access the public WiFi™ network.
Several deficiencies exist with modern tethering scenarios (See e.g., the tethering configuration between the tetheree laptop 112 a and the tethered cell phone or PDA 112 b of FIG. 1 ). A few of these deficiencies include, but are not limited to, the following:
1) a tethered device (the device acting as a modem and/or gateway for another device 112 b ) is typically not separately functional during the period of time when it is being used as an external modem (when it is in a “tethering mode”); if the device is functional, it will be significantly burdened by the tethering functions occurring in the background, and normal application processing and networking functions may be temporarily burdened to the point where they become impractical;
2) a tethered device 112 b , acting as a connected dongle, is often bulky and awkward to keep connected by wireline coupling to a tetheree PCD 112 a (the device using the tethered device as an external modem);
3) tethering network access authentication sessions generally require continuous use of the tethered device's 112 b processor in order to facilitate access to internal subscriber authentication information and routed data communications between a tetheree device 112 a and a network, thereby consuming the tethered device's 112 b resources (e.g., battery power, processing power, available volatile memory, etc.) and limiting an available data transfer rate for the tethered device;
4) a tethered device 112 b , such as cellular phone or a PDA, often has inadequate battery life to provide sufficient periods of wireless tethered communications along with the device's primary functions as a stand-alone computing device; this may require the device to be charged multiple times during the same day, thereby reducing or otherwise crippling its extended mobility;
5) a tethered device 112 b is susceptible to unwanted computer viruses as well as other malware uploads from afflicted tetheree PCDs 112 a (or vice versa) when the two devices are connected in networked communications; and
6) private and personal information resident on a tethered device 112 b can be accessed or corrupted by or through a tetheree device 112 a or a third party device 104 a connected to the tetheree PCD via a network (e.g., over the Internet) 102 when the devices are linked during a tethered communications process.
In a tethering scenario, a tetheree (e.g., a PCD such as a laptop, tablet computer or an electronic book device) can be connected to a proprietary network service by using a tethered device (e.g., a device such as a cellular phone or a PDA) as a gateway. Generally the tethered device provides the tetheree with temporary access to its network service account by facilitating network subscriber authentication while communicating with the tethered device's service provider. For many service providers in the United States and abroad, network subscriber authentication is facilitated when a service provider verifies information contained on a subscriber resident device's identification module or SIM card.
As would be understood by those skilled in the art, SIM cards are smart cards that may be configured to fit inside a mobile computing device (e.g., securely under a removable battery component), such as a cellular phone or a PDA device. In other devices identity modules or SIM cards may be built into the hardware memory of the device, such that the identification module is specifically designed not to be separated from the communications device as a detachable unit. Identity modules and SIM cards can provide for the identification of a subscribed user to a network access provider, allowing the user to access services and data that may include, but are not limited to, telephony, email, text messaging, Internet usage, GPS, etc.
An identity module, or a SIM card, generally includes a microprocessor unit as well as on-chip memory to process commands and to store user data, such as contacts and a limited amount of media content, and to store the SIM card's operating instructions. As would be understood by those skilled in the Art, identity modules and SIM cards also provide network specific information used to identify and authenticate subscribers of a cellular network service, including, but not limited to, at least the following information: an Integrated Circuit Card ID (ICC-ID), an International Mobile Subscriber Identity (IMSI), an Authentication Key (Ki), and a Local Area Identity (LAI).
Each identity module or SIM can be internationally identified by an ICC-ID stored in the module's memory and optionally engraved or printed on a physical SIM card's exterior. The ICC-ID is defined by the ITU-T recommendation and is generally up to 19 or 20 digits long. Identity modules and SIM cards may also be identified on their individual service provider networks by holding unique IMSIs. An IMSI is a unique number that is associated with all GSM, UMTS, LTE, LTE Advanced, etc. network mobile phone users. An International Mobile Subscriber Identity is up to 15 digits long. The first three digits represent the country code, followed by the network code. The remaining digits, up to fifteen, represent the unique subscriber number from within the network's customer base.
An identity module's or a SIM's authentication key (Ki) is generally a 128-bit value used in authenticating the users of a proprietary network. Each SIM holds a unique Ki assigned to it by a service provider during a SIM registration process. The Ki is also stored on a database (e.g., an authentication Center or AuC) within the service provider's network infrastructure. Generally, an identity module or SIM card does not allow a particular Ki to be obtained using the smart-card interface. Instead, the SIM card can provide a specialized function that allows a PCD to pass data to the card to be signed with the Ki. This makes usage of the SIM card mandatory unless the Ki can be extracted from the SIM card, or a service provider is willing to reveal or duplicate a Ki. In practice, most service providers prefer to keep only one copy of a particular Ki per customer account so that duplicate and/or separate SIM cards would need to be purchased by the customer to facilitate multi subscriber account access.
A subscriber authentication process may include a subscriber PCD (having an identity module or SIM card therein) powering on and then obtaining the IMSI from SIM card memory. The subscriber PCD then passes the IMSI to its registered service provider that is requesting access authentication. The subscriber PCD may further be required to pass a personal identification number (PIN) to the SIM card before the SIM card will reveal the IMSI information to the service provider.
After receiving the IMSI, the service provider searches its database for the incoming IMSI's associated Ki. The service provider then generates a Random Number (RAND, a nonce that is used only once) and signs it with the Ki associated with the IMSI (and stored on the SIM card), computing another number known as Signed Response 1 (SRES1). The service provider then sends the RAND to the PCD, which passes it to the identity module or SIM card. The identity module of SIM card signs it with its Ki, producing SRES2, which it subsequently returns to the PCD, along with encryption key Kc. The subscriber's PCD passes SRES2 on to the service provider via the network. The service provider then compares its computed SRES1 with the received computed SRES2. If the two numbers match, the SIM is authenticated and the PCD is granted access to the service provider's network. Subsequently, the Kc may be utilized to encrypt all further communications between the subscriber PCD and the service provider network.
A common scenario may exists where a first stand-alone PCD with WiFi™ communications capability is not in proximity to a free public WiFi™ access point. For example, this may occur when a user in an automobile, at an airport, staying in a hotel, etc. In these scenarios, a user may only have access to a proprietary WiFi™ or WiMAX™ network that requires them to pay exorbitant hourly or day-use fees to access the private network. In other scenarios, access to a wireless local access network, or WLAN, may simply be unavailable at a PCD's present location.
To remedy these scenarios some service providers offer device-specific plug-in cellular transceiver/antenna components (e.g., USB transceiver 110 b or PCI card transceiver 114 b of FIG. 1 ) that have a service subscriber's identification and account access data built into the plug-in device, such that a subscriber is capable of purchasing this additional access device and associated service to access a proprietary network (e.g., a cellular broadband network) using the additional service provider device. These additional plug-in devices can provide an individual network user's PCD with cellular broadband access in accordance with varying access provider specific data-rate plans, which may be separate from an existing customer's cellular phone or PDA data rate plan. Generally, a customer with a cellular telephone or a PDA pays fees for both their cellular phone network data access and their additional PCD modem's network data access as a separate monthly or annual subscriber fees.
FIG. 1 depicts one example of a modern distributed computing system 100 where several subscriber devices 108 a - c , 110 a , 112 a , and 114 a can independently access a service provider's network using various internal (e.g., those associated with cell phones 108 a - c ) and external communications transceivers (e.g., any of proprietary transceiver devices 110 b , 112 b , and 114 b ). The modern distributed computing system 100 may include, but is not limited to: a data communications network 102 (e.g., including WANs, LANs and backhaul network components), various distributed server devices 104 a - c (e.g., associated with various control centers/devices, switching centers, Internet servers, proxy servers, etc.), various cellular network base stations 106 a - b , various stand-alone personal communications devices 108 a - c (e.g., cellular phones or PDAs having internal subscriber SIMs and subscriber network transceivers), as well as various tethered personal computing devices 110 a , 112 a , and 114 a (e.g., tablet computers, e-book devices, and laptop or netbook computers) that are connected to various tethered devices, including, USB-connected transceivers 110 b , cellular phone (tethering) transceivers 112 b , and PCI card or laptop plug-in transceivers 114 b.
FIG. 2 depicts one example of a modern Multi-Function Computing Device (MFCD) 200 (e.g., such as a cellular phone or a PDA device) having at least the following components: a central processing unit/digital signal processor 202 , a transcoder 204 , a system memory 206 including both volatile (RAM) and nonvolatile (ROM) memory components, a user interface/display 208 , a smart card/smart card reader 210 , a universal serial bus (USB) 212 , a flash drive memory component 214 , a rechargeable DC power supply 216 , a WiFi™ transceiver 218 , a Bluetooth™ transceiver 220 , a GPS transceiver 222 , a cellular network transceiver 224 , an audio amplifier 226 , a speaker 228 , a microphone 230 , a MEMS unit 232 , and a system bus 234 .
The MFCD 200 may include one or more different communications transceivers (e.g., WiFi™ 218 , Bluetooth™ 220 , GPS 222 , and Cellular 224 transceivers) for communicating over both Local Area Networks (e.g., LANs, including WiFi™ enabled networks) and Wide Area Networks (e.g., WANs, including cellular and satellite communications networks). In order for the MFCD 200 to access a proprietary cellular communications network that can provide for both digital telephony and Internet data access to the Internet, the MFCD 200 will typically be required to provide subscriber identity information to authenticate access with a local network service provider. This authenticated access (the process of which is described above) generally requires communication between a network service provider (e.g., authentication with either network base station 106 a or 106 - b of FIG. 1 ) and the MFCD's 200 internal SIM card 210 .
Even with the advent of modern tethering technologies, most network subscribers (with a single network service account) have only one SIM card within their MFCD 200 . This single SIM card may only provide for subscriber account access with a single protected SIM authentication key (Ki). As such, these subscribers are only able to utilize one PCD at a time to access their network subscriber account. Switching their single SIM card between devices (only possible when both PCDs have SIM readers, such as a pair of cellular phones) is often cumbersome and time-consuming. Further, modern tethered standalone transceiver devices heavily burden and/or incapacitate a tethered device (the device acting as a modem) in order to connect a tetheree device to a proprietary communication network. Therefore it would be beneficial to have a truly portable SIM transceiver device that was physically and functionally separate or optionally separable from a user's PCD. It would also be advantageous if this portable SIM transceiver could facilitate shared access and easy switching amongst multiple subscriber devices without burdening functionality and/or resources of any of a user's standalone PCDs. It would also be beneficial if this transceiver device could be alternately adapted to facilitate shared access to a proprietary WiFi™, WiMAX™, and/or Cellular communications network.
SUMMARY OF THE INVENTION
This summary is provided to introduce (in a simplified form) a selection of concepts that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
In overcoming the above disadvantages associated with modern wireless data communications system devices and methods that facilitate proprietary network service access for mobile user equipment, the portable gateway device of the present invention facilitates shared access the same subscriber-based network for one or more communicating personal computing devices. In an embodiment, the portable gateway device includes: a local power supply, one or more processors, one or more memories, an identification module associated with a proprietary wireless network, a first wireless communications component, and a second wireless communications component having longer range communications capability than the first wireless communications component. The portable gateway device facilitates shared access to a proprietary wireless network by: establishing communications with a first external computing device using the first wireless communications component, authenticating access with the proprietary wireless network using the second wireless communications component, and subsequently relaying communications between the first external computing device and the proprietary wireless network using both the first and the second wireless communications components.
In accordance with another aspect of the present invention, the second wireless communications component has WiMAX communications capability and the first wireless communications component has WiFi or Bluetooth communications capability.
In accordance with yet another aspect of the present invention, the portable gateway device facilitates a second external computing device accessing the proprietary wireless network at the same time the first external computing device has access to the proprietary wireless network.
In accordance with another a further aspect of the present invention, the portable gateway device can facilitate simultaneous data transfers for the first and second external computing devices by allocating available bandwidth access with the proprietary wireless network to the first and second external computing devices equally.
In accordance with yet a further aspect of the present invention, the portable gateway device can facilitate simultaneous data transfers for the first and second external computing devices by allocating available bandwidth access with the proprietary wireless network to the first and second external computing devices in accordance with a predefined set of data transfer prioritization rules.
In accordance with another aspect of the present invention, the portable gateway device authenticates access for the first external computing device before the proprietary wireless network authenticates access for the portable gateway device.
In accordance with yet another aspect of the present invention, a user of the first external computing device who is registered as the owner of the portable gateway device is prompted prior to allowing the second external computing device shared access to the proprietary wireless network. This allows the owner to control access privileges affiliated with their proprietary wireless network account.
In accordance with a further aspect of the present invention is a computer-readable medium encoded with computer-executable instructions that facilitate shared access to a proprietary wireless communications network. When executed following processes are performed: initiating a portable gateway device comprising and identification module associated with a proprietary wireless network, establishing communications between a first external computing device and the portable gateway device using a first wireless communications component of the portable gateway device, authenticating access to the proprietary wireless network with a second wireless communications component of the portable gateway device that has longer range communications capability than the first wireless communications component, and then relaying communications between the first external computing device and the proprietary wireless network using both the first and the second wireless communications components.
In accordance with yet a further aspect of the present invention is a computer implemented method that facilitate shared access to a proprietary wireless communications network, the method including the following processes: initiating a portable gateway device comprising and identification module associated with a proprietary wireless network, establishing communications between a first external computing device and the portable gateway device using a first wireless communications component of the portable gateway device, authenticating access to the proprietary wireless network with a second wireless communications component of the portable gateway device that has longer range communications capability than the first wireless communications component, and then relaying communications between the first external computing device and the proprietary wireless network using both the first and the second wireless communications components.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary and alternative examples of the present invention are described in detail below with reference to the following Figure drawings:
FIG. 1 illustrates a perspective view of a distributed computing system associated with the Prior Art;
FIG. 2 illustrates a block diagram of a personal computing device associated with the Prior Art;
FIG. 3 illustrates a perspective view of a distributed computing system with multiple portable gateway devices in accordance with embodiments of the present invention;
FIG. 4 illustrates a perspective view of a personal computing device with a removable portable gateway device and an attachable power supply component in accordance with an embodiment of the present invention;
FIG. 5 illustrates a block diagram of a portable gateway device with an attachable power supply component (See e.g., FIG. 4 ) in accordance with an embodiment of the present invention;
FIG. 6 illustrates a block diagram of a personal computing device having a detachable portable gateway device (See e.g., FIG. 4 ) in accordance with an embodiment of the present invention;
FIG. 7 illustrates a perspective view of a personal computing device located in proximity to an autonomous portable gateway device in accordance with an embodiment of the present invention;
FIG. 8 illustrates a block diagram of an autonomous portable gateway device (See e.g., FIG. 7 ) in accordance with an embodiment of the present invention;
FIG. 9 illustrates a flow diagram of a process that utilizes a portable gateway device to access proprietary network services (e.g., those associated with WiFi, WiMAX, and 3G or 4G cellular networks) in accordance with embodiments of the present invention;
FIG. 10 illustrates a communication flow diagram of processes where multiple personal computing devices simultaneously access separate networks in accordance with an embodiment of the present invention;
FIG. 11 illustrates a communication flow diagram of a process where a personal computing device accesses a proprietary WiFi or WiMAX network using a portable gateway device in accordance with embodiments of the present invention; and
FIG. 12 illustrates a communication flow diagram of a process where a personal computing device accesses a proprietary cellular network using a portable gateway device in accordance with embodiments of the present invention.
DETAILED DESCRIPTION
In accordance with exemplary embodiments of the present invention, FIG. 3 illustrates a distributed computing system 300 including various wireline and wireless computing devices that may be utilized to implement any of the data communications processes associated with various embodiments of the present invention (e.g., processes associated with any of FIGS. 9-12 ). The distributed computing system 300 may include various personal computing devices (PCDs) 312 a - c , 314 , 316 , and 318 having access to a service provider network 302 (e.g., including a backhaul) by communicating wirelessly with various server provider devices, including base stations 306 a - b , and 310 , as well as any number or router 308 or server and controller computing devices 304 a - c common in the Art using various portable gateway devices 320 a - c associated with embodiments of the present invention.
As would be understood by those skilled in the Art, in most digital communications networks, the backhaul portion of a data communications network 302 may include the intermediate, generally wireline, links between a backbone of the network, and the sub-networks or network base stations 306 a - b , and 310 , located at the periphery of the network. For example, user equipment (also referred to herein as PCDs) 312 a - c , 314 , 316 , and 318 communicating with one or more network base stations 306 a - b , and 310 may constitute a local sub-network. Whereas the network connection between any of the network base stations 306 a - b , and 310 and the rest of the world initiates with a link to the backhaul portion of an access provider's communications network 302 (e.g., via a point of presence).
In an embodiment, any of the portable gateway devices 320 a - c , and/or network base stations 306 a - b , and 310 may function collaboratively to implement any of the shared network access processes associated with various embodiments of the present invention. Further, any of the shared network access processes may be carried out via any common communications technology known in the Art, such as those associated with modern Global Systems for Mobile (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE) network infrastructures, etc. In accordance with a standard GSM network, any of the service provider devices 304 a - c , 306 a - b , 308 , 310 may be associated with a base station controller (BSC), a mobile switching center (MSC), or any other common service provider device known in the art, such as a radio resource manager (RRM). In accordance with a standard UMTS network, any of the service provider devices 304 a - c , 306 a - b , 308 , 310 may be associated with a network resource controller (NRC), a serving GPRS support node (SGSN), or any other common service provider controller device known in the art, such as a radio resource manager (RRM). In accordance with a standard LTE network, any of the service provider devices 304 a - c , 306 a - b , 308 , 310 may be associated with an eNodeB base station, a mobility management entity (MME), or any other common service provider controller device known in the art, such as a radio resource manager (RRM).
In an embodiment, any of the service provider devices 304 a - c , 306 a - b , 308 , 310 as well as any of the PCDs 312 a - c , 314 , 316 , and 318 may be configured to run any well-known operating system, including, but not limited to: Microsoft® Windows®, Mac OS®, Google® Chrome®, Linux®, Unix®, or any well-known mobile operating system, including Symbian®, Palm®, Windows Mobile®, Google® Android®, Mobile Linux®, etc. In an embodiment, any of the service provider devices 304 a - c , 306 a - b , 308 , 310 may employ any number of common server, desktop, laptop, and personal computing devices.
In an embodiment, any of the PCDs 312 a - c , 314 , 316 , and 318 may be associated with any combination of common mobile computing devices (e.g., laptop computers, netbook computers, tablet computers, cellular phones, PDAs, handheld gaming units, electronic book devices, personal music players, video recorders, etc.), having wireless communications capabilities employing any common wireless data communications technology, including, but not limited to: GSM, UMTS, 3GPP LTE, LTE Advanced, WiFi, WiMAX, etc.
In an embodiment, the backhaul portion of the data communications network 302 of FIG. 3 may employ any of the following common communications technologies: optical fiber, coaxial cable, twisted pair cable, Ethernet cable, and powerline cable, along with any other wireless communication technology known in the art. In an embodiment, any of the service provider devices 304 a - c , 306 a - b , 308 , 310 as well as any of the PCDs 312 a - c , 314 , 316 , and 318 may include any standard computing software and hardware necessary for processing, storing, and communicating data amongst each other within the networked computing system 300 . The computing hardware realized by any of the network computing system 300 devices (may include, but is not limited to: one or more processors, volatile and non-volatile memories, user interfaces, transcoders, modems, wireline and/or wireless communications transceivers, rechargeable power supplies, etc.
Further, any of the portable gateway devices 320 a - c , service provider devices 304 a - c , 306 a - b , 308 , 310 , as well as any of the PCDs 312 a - c , 314 , 316 , and 318 may include one or more computer-readable media (e.g., any common volatile or non-volatile memory type) encoded with a set of computer readable instructions, which when executed, can perform a portion of any of the shared network access processes associated with various embodiments of the present invention. In context with various embodiments of the present invention, it should be understood that wireless communications coverage associated with various data communication technologies (e.g., network base stations 106 a - b , and 310 ) typically vary amongst different service provider networks based on the type of network and the system infrastructure deployed within a particular region of a network (e.g., differences amongst GSM, UMTS, LTE, LTE Advanced, WiFi and WiMAX based networks and the technologies deployed in each network type).
FIG. 4 illustrates a perspective view 400 of a personal computing device 402 (e.g., a cellular phone or a PDA or any of the other PCDs 312 a - c , 314 , 316 , and 318 of FIG. 3 ) and a removable portable gateway device 404 a - b that has an optional, attachable power supply component 412 in accordance with an embodiment of the present invention. In an embodiment, the portable gateway device 404 a - b and the power supply component 412 include all the hardware components depicted in the block diagram of FIG. 5 . In an embodiment the portable gateway device 404 a - b may be removed from the PCD 402 by pressing or turning the removable device 404 a - b , such that it readily detaches from the PCD 402 without much effort on the part of a user. Subsequent to being removed from the PCD 402 , the portable gateway device 404 a - b may be joined with the power supply component 412 by pressing the two components together, such that they lock securely and act as a single autonomous device. In an embodiment, the autonomous portable gateway device 404 a - b , 412 may be a snap fit device where peripheral components 410 a - c of the portable gateway device 404 a - b lock with peripheral recesses 414 a - c of the power supply component 412 , when joined. It should be understood that the portable gateway device 404 a - b has an identity module embodied 406 therein and an optional array of indicator lights to signal power level and/or communications signal strength for communications with a neighboring base station (e.g., any of base stations 306 a - b , and 310 of FIG. 3 ). It should also be understood that the power supply component 412 has a rechargeable battery component 416 (e.g., such as a rechargeable lithium ion battery) stored therein.
FIG. 5 illustrates a block diagram 500 of a portable gateway device 502 with an attachable power supply component 526 (See e.g., FIG. 4 ) in accordance with an embodiment of the present invention. The portable gateway device may be representative of any of the portable gateway devices 320 a - c depicted in FIG. 3 . In an embodiment, the portable gateway device 502 may include, but is not limited to, the following components: a central processing/digital signal processing component 502 , a transcoders 506 , an identity module 508 (e.g., such as a smart card or SIM card), a serial bus 510 , a system memory 512 , an array of indicator lights 514 , a short range communications transceiver 516 (i.e., such as a Bluetooth or a WiFi transceiver) and one or more long range transceiver components 518 , 520 (i.e., such as a Cellular transceiver and/or a WiMAX transceiver), and a system bus 522 facilitating communication amongst all components of the portable gateway device 502 .
In an embodiment, the CPU/DSP 504 may include an arithmetic logic unit (ALU, not shown) that performs arithmetic and logical operations and one or more control units (CUs, not shown) that extract instructions and stored content from memory and then executes and/or processes them, calling on the ALU when necessary during program execution. The CPU 504 may be responsible for executing all shared data communications and authentication software stored on the portable gateway device's 502 volatile (RAM) and non-volatile (ROM) system memories, 512 . In an embodiment, the identity module 508 (e.g., such as a smart card or SIM card) may facilitate the portable gateway device's 502 authentication with a proprietary network service provider. In an embodiment, one or more users of local PCDs (e.g., any of PCDs 312 a - c , 314 , 316 , and 318 ) may communicate with the portable gateway device's 502 short range communications transceiver 516 (i.e., such as a Bluetooth or a WiFi transceiver) to request individual and/or simultaneous access to a proprietary network service. In an embodiment, the portable gateway device 502 may authenticate one or more shared user access requests at the portable gateway device 502 and then submit/forward one or more data transfer requests (along with authentication information associated with the identity module 508 ) to a remote service provider device (e.g., any of base stations 306 a - b , and 310 of FIG. 3 ) using a longer range transceiver component 518 , 520 (i.e., such as a Cellular transceiver and/or a WiMAX transceiver). After authentication with a remote service provider device, the portable gateway device 502 may act as a relay/gateway between one or more PCDs (e.g., any of PCDs 312 a - c , 314 , 316 , and 318 ) and a service provider device (e.g., any of base stations 306 a - b , and 310 ) offering data communications services.
In an embodiment, the attachable power supply component 526 may include both a rechargeable power supply 528 (e.g., a lithium ion battery), a power charging unit 530 for allowing the attachable power supply component 526 to plug into a shore power source (not shown), and a connector 524 for connecting the attachable power supply component 526 to the portable gateway device 502 .
FIG. 6 illustrates a block diagram of a personal computing device 600 having a detachable portable gateway device (See e.g., FIG. 5 ) in accordance with an embodiment of the present invention. The PCD 600 may be representative of any of the PCDs 312 a - c , 314 , 316 , and 318 depicted in FIG. 3 . In an embodiment, the PCD 600 may include, but is not limited to, the following components: a central processing/digital signal processing component 602 , a transcoder 604 , a system memory 606 , a detachable PGD plug-in component 608 , a serial bus 610 , a flash drive 612 , a rechargeable power supply 614 , a user interface/display 616 , a short range communications transceiver 620 (i.e., such as a Bluetooth or a WiFi transceiver) and one or more longer range transceiver components 618 , 622 , (i.e., such as a WiMAX and/or a GPS transceiver), and audio amplifier 624 , a speaker 626 , a MEMS unit 630 , and a system bus 632 facilitating communication amongst all components of the PCD 632 .
In an embodiment, the CPU/DSP 602 may include an arithmetic logic unit (ALU, not shown) that performs arithmetic and logical operations and one or more control units (CUs, not shown) that extract instructions and stored content from memory 606 and then executes and/or processes them, calling on the ALU when necessary during program execution. The CPU/DSP 602 may be responsible for controlling data communications and executing software stored in the personal computing device's 600 memory 606 .
FIG. 8 illustrates a block diagram of an autonomous portable gateway device 800 (See e.g., 704 of FIG. 7 ) in accordance with an embodiment of the present invention. The autonomous PGD 800 may be representative of any of the portable gateway devices 320 a - c depicted in FIG. 3 . In an embodiment, the portable gateway device 800 may include, but is not limited to, the following components: a central processing/digital signal processing component 802 , a transcoder 804 , an identity module 808 (e.g., such as a smart card or SIM card), a serial bus 810 , a system memory 806 , an array of indicator lights 822 , an ON/OFF switch 814 , a power supply/charging unit 812 , a short range communications transceiver 816 (i.e., such as a Bluetooth or a WiFi transceiver) and one or more long range transceiver components 818 , 820 (i.e., such as a Cellular transceiver and/or a WiMAX transceiver), and a system bus 824 facilitating communication amongst all components of the autonomous PGD 800 .
In an embodiment, the CPU/DSP 802 may include an arithmetic logic unit (ALU, not shown) that performs arithmetic and logical operations and one or more control units (CUs, not shown) that extract instructions and stored content from memory and then executes and/or processes them, calling on the ALU when necessary during program execution. The CPU 802 may be responsible for executing all shared data communications and authentication software stored on the autonomous PGD's 800 volatile (RAM) and non-volatile (ROM) system memories, 806 . In an embodiment, the identity module 808 (e.g., such as a smart card or SIM card) may facilitate the autonomous PGD's 800 authentication with a proprietary network service provider. In an embodiment, one or more users of local PCDs (e.g., any of PCDs 312 a - c , 314 , 316 , and 318 ) may communicate with the autonomous PGD's 800 short range communications transceiver 816 (i.e., such as a Bluetooth or a WiFi transceiver) to request individual and/or simultaneous access to a proprietary network service. In an embodiment, the autonomous PGD 800 may authenticate one or more shared user access requests at the autonomous PGD 800 and then submit/forward one or more data transfer requests (along with authentication information associated with the identity module 808 ) to a remote service provider device (e.g., any of base stations 306 a - b , and 310 of FIG. 3 ) using a longer range transceiver component 818 , 820 (i.e., such as a Cellular transceiver and/or a WiMAX transceiver). After authentication with a remote service provider device, the autonomous PGD 800 may act as a relay/gateway between one or more PCDs (e.g., any of PCDs 312 a - c , 314 , 316 , and 318 ) and a service provider device (e.g., any of base stations 306 a - b , and 310 ) offering data communications services.
FIG. 9 illustrates a flow diagram 900 of a process that utilizes a portable gateway device to access proprietary network services (e.g., those associated with WiFi, WiMAX, and 3G or 4G cellular networks) in accordance with embodiments of the present invention. It should be understood that these processes 900 may be executed independently or collectively using one or more computer-executable programs stored on computer-readable media located on one or more PCDs (e.g., any of PCDs 312 a - c , 314 , 316 , and 318 ), a PGD (e.g., any of PGDs 320 a - c ) and network service provider devices (e.g., any of network base stations 306 a - b , and 310 ). The process 900 is comprised of flow diagram steps 902 , 904 , 906 , 908 , 910 , 912 , 914 , 916 , 918 , 920 , 922 , 924 , 926 , and 928 . Process 900 is depicted/described in sufficient textual and illustrative detail to facilitate understanding by one of ordinary skill in the Art reviewing FIG. 9 in combination with FIGS. 3-8 .
FIG. 10 illustrates a communication flow diagram of process 1000 where multiple personal computing devices simultaneously access separate networks (e.g., WiFi, WiMAX, and/or 3G or 4G Cellular networks) in accordance with an embodiment of the present invention. In an embodiment, the system includes a first PCD 1 1002 (e.g., optionally, a PGD host, See e.g., FIG. 4 ), a second PGD 2 1004 , a PGD 1006 , a WiFi or WiMAX network 1010 , and a cellular network 1008 . It should be understood that these process 1000 may be executed independently or collectively using one or more computer-executable programs stored on computer-readable media located on one or more PCDs (e.g., any of PCDs 312 a - c , 314 , 316 , and 318 ), a PGD (e.g., any of PGDs 320 a - c ) and network service provider devices (e.g., any of network base stations 306 a - b , and 310 ). The process 1000 is comprised of flow diagram steps 1012 , 1014 , 1016 , 1018 , 1020 , 1022 , 1024 , 1026 , 1028 , 1030 , 1032 , and 1034 . Process 1000 is depicted/described in sufficient textual and illustrative detail to facilitate understanding by one of ordinary skill in the Art reviewing FIG. 10 in combination with FIGS. 3-8 .
FIG. 11 illustrates a communication flow diagram of a process 1100 where a personal computing device accesses a proprietary WiFi or WiMAX network using a portable gateway device in accordance with embodiments of the present invention. In an embodiment, the system includes a first PCD 1102 , a PGD 1104 , and a WiFi or WiMAX network 1106 . It should be understood that this process 1100 may be executed independently or collectively using one or more computer-executable programs stored on computer-readable media located on one or more PCDs (e.g., any of PCDs 312 a - c , 314 , 316 , and 318 ), a PGD (e.g., any of PGDs 320 a - c ) and network service provider devices (e.g., any of network base stations 306 a - b , and 310 ). The process 1100 is comprised of flow diagram steps 1108 , 1110 , 1112 , 1114 , 1116 , and 1118 . Process 1100 is depicted/described in sufficient textual and illustrative detail to facilitate understanding by one of ordinary skill in the Art reviewing FIG. 11 in combination with FIGS. 3-8 .
FIG. 12 illustrates a communication flow diagram of a process 1200 where a personal computing device accesses a proprietary cellular network using a portable gateway device in accordance with embodiments of the present invention. In an embodiment, the system includes a first PCD 1202 , a PGD 1204 , and a 3G or 4G Cellular network 1206 . It should be understood that this process 1200 may be executed independently or collectively using one or more computer-executable programs stored on computer-readable media located on one or more PCDs (e.g., any of PCDs 312 a - c , 314 , 316 , and 318 ), a PGD (e.g., any of PGDs 320 a - c ) and network service provider devices (e.g., any of network base stations 306 a - b , and 310 ). The process 1200 is comprised of flow diagram steps 1208 , 1210 , 1212 , 1214 , 1216 , and 1218 . Process 1200 is depicted/described in sufficient textual and illustrative detail to facilitate understanding by one of ordinary skill in the Art reviewing FIG. 12 in combination with FIGS. 3-8 .
While several embodiments of the present invention have been illustrated and described herein, many changes can be made without departing from the spirit and scope of the invention. | A portable gateway device facilitating shared access to a proprietary wireless network. The portable gateway device acts as an external modem for one or more auxiliary personal computing devices, and the device includes: a local power supply, one or more processors, one or more memories, an identification module associated with a proprietary wireless network, a first wireless communications component, and a second wireless communications component having longer range communications capability than the first wireless communications component. The portable gateway device is configured to facilitate one or more external computing device accessing the proprietary wireless network by: establishing communications with a first external computing device using the first wireless communications component, authenticating access with the proprietary wireless network using the second wireless communications component, and subsequently relaying communications between the first external computing device and the proprietary wireless network using both the first and the second wireless communications components. | 7 |
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