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The following application claims priority under 35 USC 119 for provisional application 60/046,557 filed May 15, 1997.
FIELD OF THE INVENTION
The present invention relates to a method for controlling curl of paper in which steam treatment, moistening of the paper web and/or equivalent operations are employed in order to control the curl of the paper web.
Also, the present invention relates to a paper or board machine including a headbox, a former, a press, a dryer section and steam boxes, moistening devices, means for applying a one-sided drying impulse to the web and/or equivalent devices for controlling curl of the paper web.
BACKGROUND OF THE INVENTION
In the prior art, in multi-cylinder dryers of paper machines, twin-wire draw and/or single-wire draw is/are employed. When employing twin-wire draw, a group of drying cylinders comprises two closed (endless) wires, fabrics or belts which press the web, one from above and the other one from below, against heated cylinder faces of drying cylinders arranged in rows. Between the rows of drying cylinders, which are usually horizontal rows, the web has free and unsupported draws which are susceptible to fluttering and may cause web breaks, in particular when the web is still relatively moist and, therefore has a low strength. For this reason, in recent years, ever increasing use has been made of the single-wire draw in which each group of drying cylinders includes only a single closed (endless) drying wire on whose support the web runs through the entire group so that the drying wire presses the web on the drying cylinders against the heated cylinder faces thereof, whereas on the reversing cylinders or rolls arranged between the drying cylinders, the web remains at the side of the outside curve and is subjected to negative pressure as it runs over the reversing cylinders or rolls in order to maintain the web on the wire. Thus, in single-wire draw, the drying cylinders are arranged outside the wire loop, and the reversing cylinders or rolls are arranged inside the wire loop.
In so-called normal groups with single-wire draw, known in the prior art, the heated drying cylinders are placed in an upper row and the reversing cylinders or rolls are placed in a lower row below the upper row of drying cylinders, which rows are typically horizontal and parallel to one another. In the following, when the term "normal (dryer) group" is used, what is meant is expressly groups with single-wire draw in multi-cylinder dryers of the type mentioned above.
It is known to those skilled in the art that if paper is dried one-sidedly or unequalsidedly, the result is a tendency of curling of the sheet. For example, when paper is dried by means of normal groups with single-wire draw from the side of its bottom face only, the drying is asymmetric and if such asymmetric drying is extended over the entire length of the forward dryer section, the drying takes place so that first the bottom-face side of the paper web is dried and, when the drying makes progress, the drying effect is also extended to the side of the top face of the paper web. Under these circumstances, the dried paper is usually curled and becomes concave, when viewed from above.
As known in the prior art, the tendency of curling of paper (or the tendency to curl) is already affected in connection with the web formation, in particular at the sheet formation stage by means of the selection of the difference in speed between the slice jet and the wire, by means of the selection of the former and its mode of running and by means of other running parameters. For example, in the case of copying paper, by means of unequalsidedness of drying in the afterdryer, a suitable initial curl form is regulated for the sheet in order that the curling of the paper after one-sided or double-sided copying could be optimized. In the case of copying paper, the reactivity of curling, i.e., the extent to which curling occurs per unit of change in moisture content, is affected to a greater extent by means of a multi-layer structure of the paper, which is produced in connection with the web formation in the wet end.
With respect to the prior art related to the present invention, reference is made to the current assignee's Finnish Patent No. 91,900 (corresponding to U.S. Pat. No. 5,416,980 incorporated by reference herein), in which a method is described in the dryer section of a paper machine in particular for reducing the tendency of curling of paper. In this method, the paper web is dried by means of drying cylinders against whose heated faces the paper web is pressed by a drying wire. In the dryer section, groups of drying cylinders are used in which twin-wire draw and/or single-wire draw is/are applied. In this method, it has been considered advantageous that in the dryer section, substantially across the entire width of the paper web, hot water or steam is fed to relax strains or tensions that arise or tend to arise in the fiber mesh in the paper web in, or substantially directly after, the area of formation of the strains or tensions.
In the current assignee's Finnish Patent Application No. 963734 (corresponding to U.S. provisional patent application Ser. No. 60/030,693), a method is described for drying a surface-treated paper web or equivalent in an after-dryer of a paper machine as well as a dryer section of a paper machine for applying the method. With a view toward compensating for a tendency of curling of the paper web, in the after-dryer, the paper web is dried in a dryer group/groups making use of a normal single-wire draw. In connection with or after the drying, the paper web is treated by means of at least one device in order to compensate for a tendency of curling of the paper web, which devices are, for example, a steam box, a blower unit, a moistening device, and/or a soft calender.
On the other hand, in the current assignee's Finnish Laid-open Publication No. 98,387 (corresponding to U.S. patent application Ser. No. 08/705,059), a method is described for manufacturing a paper to be surface-treated, in particular fine paper, as well as a dry end of a paper machine for applying the method. The paper web, which has been dewatered by pressing, is dried in a forward dryer section in which drying energy is applied to the paper web over the entire length of the forward dryer section asymmetrically in the z-direction from the side of the bottom face of the web. This stage is carried out by means of a number of successive groups with single-wire draw that are open towards the bottom while the web is carried on support of a drying wire. In this manner, shrinkage of the web both in the machine direction and in the cross direction is substantially prevented, which shrinkage tends to occur with an increase in the dry solids content. In connection with a web break, the paper broke is removed from below the dryer groups that are open towards the bottom onto a broke conveyor placed underneath substantially by the effect of gravity. The paper web, which has a tendency of curling because of the asymmetric forward drying, then is passed into an after-dryer in which it is after-treated while, at the same time, moistened and/or plastically worked, so that the tendencies of curl that arose in it in the forward drying stage are eliminated. For example, the after-dryer may include groups with twin-wire draw and regulation of steam as well as steam boxes that have been arranged in view of controlling the curl, as well as infra and airborne web dryers.
In the current assignee's Finnish Patent Application 964830 (corresponding to U.S. Provisional Patent Application Ser. No. 60/032,405), a method is described for drying paper as well as a dry end of a paper machine. The method for drying of paper comprises the following steps:
the paper web to be dried is passed from the press section into a forward dryer section, in which the paper web is dried from the side of its bottom face in dryer groups that apply a normal single-wire draw, the forward dryer section comprises exclusively single-wire groups with normal single-wire draw,
the paper web is passed from the forward dryer section into a finishing section in which the paper web is coated/surface-sized by means of coating/surface-sizing equipment,
the paper web is passed from the finishing section to be dried in an after-dryer section in which the paper web is dried in at least one dryer group that applies normal single-wire draw,
after the after-dryer section, the paper web is calendered in a calender and passed to a reeling station in which the paper web is reeled into a machine reel, and
curling of the paper web is controlled by means of curl control elements and/or by means of assemblies and combinations formed out of such elements in the area of the forward dryer section and/or the finishing section.
The dry end of a paper machine described in FI 964830 comprises a forward dryer section, a finishing section which comprises a coating/surface-sizing apparatus, an after-dryer, a calender and a reeling station. The dry end of the paper machine comprises curl control elements and/or assemblies and combinations formed out of such curl control elements in view of controlling the curling of the paper web in the area of the forward dryer section and/or the finishing section. The elements for controlling the curling comprise, among other things, means for blowing hot moist air through the wire in the forward dryer section, steam boxes employed in the after-dryer, a combination in which steam-treatment by means of a steam box is combined with a cooling cylinder, a lower support belt or support wire in the after-dryer, twin-wire groups employed in the after-dryer, means for through-drying through the wire in connection with at least one cylinder in the after-dryer, a pre-selected ratio of cylinder diameters, means for spraying water against the web in the after-dryer, infrared boxes arranged before the calender, means for transferring moist air from the forward dryer to the after-dryer to be blown against the web, and mechanical working of the web by means of a spreader bar.
With respect to the prior art, reference is also made to U.S. Pat. No. 5,557,860, in which a dryer section is described which includes dryer groups that make use of a normal single-wire draw and a moistening device arranged after the dryer groups by whose means the curl is controlled.
From the prior art, it is also known to moisten the air that surrounds a winding device, in which case drying and shrinkage of the paper in the winding device are prevented. An excessively low relative humidity of the air surrounding the winding device results in uncontrolled drying and shrinkage of the paper, which again causes cutting off of the paper at the knife blades and makes the slitting more difficult and also makes the formation of splices more difficult. Under excessively dry conditions, there may also be difficulties in meeting the requirements of dimensional precision imposed on a roll. This prior art moistening system comprises moistening nozzles and air devices installed below the winding device. By means of these devices, the air that rises to the winding device is moistened and directed at the knife blades under controlled conditions. If necessary, the moisture level can be adjusted continuously. Thus, in this prior art construction, control of the curl of paper is not aimed at.
In the prior art constructions described above, the devices for the regulation of curl and the other, corresponding arrangements are placed in the dry end of the paper machine before the calender. It has been assumed that, if curl regulation operations are carried out after the calender, they have a detrimental effect on the surface properties of the paper. However, it is a drawback of a curl regulation device, such as a steam box or a moistening device, placed before the calender that, at the same time, the calendering result is affected to a great extent by the operation of the curl regulation device, i.e., the smoothness of the faces and the bulk of the paper is altered. This quite often prevents full control of the curl. On the other hand, the efficiency of a moistening/steam-treatment device suffers from the high temperature of the web. Devices arranged in the interior of the hood of the dryer section must also be designed in consideration of the hot and moist environment. Also possible servicing work must be carried out at times of standstills.
The curl regulation devices arranged before the calender must be placed near the end of the dryer section, at which time the temperature of the web and of the surrounding air is highest. In such a case, for example, the use of a steam box is not so efficient (without cooling of the web), for steam does not condense into the hot web (having a temperature of 70° C. to 80° C.) and thus, does not equalize the 2-way moisture profile. In order to cool the web, for example cooling cylinders are employed and as a result, the length of the dryer section is increased, which is not economically advisable. Also, at the end of the dryer section, owing to the hot web, larger quantities of steam or water are needed for correcting the 2-way moisture profile.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to approach the problems related to the control of curl from a new point of view and to suggest novel solutions for such problems contrary to conventional modes of thinking.
Another object of the present invention is to provide methods for controlling curl of a web and a paper or board machine in which the operations necessary for controlling and regulating the curl can be carried out after the calender.
In view of achieving the objects stated above and those that will come out later, in the method in accordance with the invention, the operations for controlling the curl of the paper web are carried out after the calendering process carried out in the calender.
In a paper or board machine in accordance with the invention, steam boxes, moistening devices and/or equivalent curl control devices for controlling curl of the paper web are placed after the calender.
According to the invention, the curl is regulated after the calendering process by means of a steam box or a moistening device or by means of any other, equivalent curl control arrangement in itself known, for example, in connection with a winder, slitter-winder, intermediate calender, Pope-type reel-up, etc. The operations necessary for controlling the curl can be carried out, for example, as steam blowing carried out in connection with a reel-up, by means of steam boxes placed before the reel-up, by means of a steam box arranged in connection with the reel that is being formed, by means of a combination of moistening and steam treatment before the reel-up, by moistening the web before the reel-up, and/or by fitting, for example, an infra heater or an equivalent device by whose means the web is dried from the opposite side. Also, the curl control operations may be carried out in connection with an unwind stand, in which case, it is possible to turn the reel around, in which connection the curl regulation effect can be applied to the opposite face of the paper web.
By means of these novel arrangements, it is possible to act upon the curl of the paper web and to regulate the curl as desired. Since the curl control operations are not carried out until after the calender, an advantage is obtained that the control of the curl takes place as close to the final product as possible, and thereby the effects of all of the preceding process factors can be taken into account effectively. The temperature of the web is also rather low, in which case the effect of the steam treatment is high. Also, the devices can be placed so that they can also be serviced, at least partly, while the machine is in operation. Nor does a regulation of curl carried out after the calender, for example one-sided steam treatment, affect the calendering process and, thus, produce differences in the final product between the top face and the bottom face, for example roughness and glaze.
The operations that are carried out in accordance with the invention in order to control the curl are applied to one side or to both sides of the web.
The invention will be described in detail with reference to some preferred embodiments of the invention illustrated in the figures in the accompanying drawing. However, the invention is not confined to the illustrated embodiments alone.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional objects of the invention will be apparent from the following description of the preferred embodiment thereof taken in conjunction with the accompanying non-limiting drawings, in which:
FIG. 1 is a schematic illustration of an exemplifying embodiment of the invention for controlling curl in connection with a reel-up;
FIG. 1A is an enlarged view of area A in FIG. 1;
FIG. 2 is a schematic illustration of an exemplifying embodiment of the invention for controlling curl in connection with an unwind stand;
FIG. 3 is a schematic illustration of an exemplifying embodiment of the invention for controlling curl after the calendering process, in which embodiment, in view of controlling curl, a steam box is arranged before the reel-up;
FIG. 4 is a schematic illustration of an exemplifying embodiment of the invention for controlling curl after the calendering process, in which embodiment, in view of controlling curl, two steam boxes are arranged before the reel-up;
FIG. 5 is a schematic illustration of an exemplifying embodiment of the invention, in which, in view of controlling curl, a steam box is arranged before the reel-up and in connection with the paper reel that is being formed in the reel-up;
FIG. 6 is a schematic illustration of an exemplifying embodiment of the invention, in which, in view of controlling curl, two steam boxes are arranged in connection with the paper reel that is being formed in the reel-up;
FIG. 7 is a schematic illustration of an exemplifying embodiment of the invention for controlling curl after the calendering process, in which embodiment, in view of controlling curl, both a moistening device and a steam device are arranged before the reel-up;
FIG. 8 is a schematic illustration of an exemplifying embodiment of the invention in which, in view of controlling curl, a moistening device is arranged before the reel-up;
FIG. 9 is a schematic illustration of an exemplifying embodiment of the invention in which, in view of controlling curl, two moistening devices are arranged before the reel-up; and
FIG. 10 is a schematic illustration of an exemplifying embodiment of the invention in which the curl control devices are arranged in connection with a supercalender.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1-10 wherein like reference numerals refer to the same or similar elements, in the exemplifying embodiment of the invention that is illustrated schematically in FIG. 1, with a view toward controlling curl of a web W, after the calender, in connection with an online or off-line reel-up, the web W is unwound from a reel 27 over reeling drum 22 and alignment/guide rolls 23, 24, 25, 26 into reel 21. The frame constructions of the reel-up are denoted generally by reference numeral 28, and the empty reel spools placed in the spool store are denoted by reference numeral 29. FIG. 1 shows possible different alternatives for placing the curl control device in connection with the reel-up 20. For example, below a reeling nip N defined between the reel 21 and the reeling drum 22, it is possible to place a steam blow box 22A or an equivalent steam or moisture application device, of which a partial enlarged illustration is shown in FIG. 1A. From the steam blow box 22A or equivalent source, steam blowings are applied either into the nip N, represented by blowing P 2 , or toward a face of the reel 21, represented by blowing P 1 . In accordance with further alternatives, a steam blow box or an equivalent steam and/or moisture application device 25A, 26A is arranged in connection with, i.e., operative against or in opposed relationship to, the respective alignment/guide roll 25,26 and a steam blow box or an equivalent steam and/or moisture application device 22B is arranged in connection with the reeling drum 22.
In the exemplifying embodiment of the invention illustrated schematically in FIG. 2, the paper web W is unwound in an unwind station 60 from a reel 61, and the web W is passed over alignment/guide rolls 62,63,64 to a slitter 65, from which it is further passed over alignment/guide rolls 66,67 to a drum winder 70. In the drum winder 70, the web W is wound into a paper roll 71 on support of winding drums 68 and 69, and in connection with the winding, a rider roll 72 is employed. Reference numeral 73 denotes a roll transfer device. With a view toward controlling curl of the web W, in connection with such an assembly of equipment, various devices are arranged to control the curl. For example, in connection with the alignment roll 63 and/or 66, it is possible to position steam blow boxes 63A,66A or equivalent steam and/or moisture application devices. In connection with the winder 70, and more particularly in connection with the winding drum 68, it is possible to arrange a steam box 68A. Further, the winding drum 69 may be a steam roll into which a steam blow zone or steam-treatment zone 69A is formed, or a steam pipe 71A may be placed in the space between the winding drums 68,69 and the paper roll 71 that is being formed. If necessary, in the unwind stage, the paper roll 61 can be turned around, in which connection the effect of the curl regulation can be applied to the opposite side of the paper web W.
In the embodiments shown in FIGS. 3-9, the last two groups R 1 ,R 2 with single-wire draw in the dry end 30 of the paper machine are seen. These dryer groups are constructed such that the web W has a closed draw in the gap therebetween. In the illustrations, the machine direction, i.e., the running direction of the web W is denoted by arrow S. The single-wire groups R 1 ,R 2 are so-called normal groups, in which steam-heated smooth-faced drying cylinders 10 are placed in an upper horizontal row and reversing suction cylinders 11 are placed in a lower horizontal row. Each dryer group R 1 ,R 2 has a drying wire 15 of its own, which is guided by guide rolls 18. The drying wires 15 press the web W to be dried against the smooth heated faces of the drying cylinders 10 and on the reversing cylinders 11 the web W remains at the side of the outside curve on the outer face of the wire 15. On the reversing cylinders 11, the web W is kept reliably on support of the wire 15 against the effect of centrifugal forces by the effect of a vacuum present in grooved faces of the reversing cylinders 11 or in a perforated mantle of an equivalent suction roll, by means of which effect cross-direction shrinkage of the web W is also counteracted. The reversing suction cylinders 11 that are used are particularly favorably suction cylinders marketed by the current assignee with the trade mark VacRoll™, which have no inside suction boxes and with respect to details of their construction, reference is made to the current assignee's Finnish Patent No. 83,680 (corresponding to U.S. Pat. Nos. 5,022,163 and 5,172,491). The support contact between the web W and the drying wire 15 is kept adequate also on the straight runs between the drying cylinders 10 and the reversing cylinders 11 by using blow-suction boxes 17 at least on the runs from the drying cylinders 10 to the reversing cylinders 11. By means of the blow-suction boxes 17, the formation of pressures induced by the wire 15 is also prevented in the closing wedge-shaped nip spaces defined between the wire 15 and the cylinder 11 mantles. The blow-suction boxes 17 are understood as blow boxes whose blowing of air produces a vacuum, and the boxes 17 do not communicate with sources of vacuum. With respect to details of their construction, the blow-suction boxes 17 may be those marketed by the current assignee with the trade mark "UnoRun BlowBox"™, and in this regard, reference is made to the current assignee's Finnish Patent Nos. 59,637, 65,460 and 80,491 (corresponding to U.S. Pat. Nos. 4,441,263, 4,516,330 and 4,905,380, respectively). Blow box constructions of other types in themselves known are also included in the scope of the overall concept of the present invention. In the groups R 1 ,R 2 with single-wire draw, blow boxes 16 are also used in the gaps between the reversing cylinders 11. By means of the blow boxes 16, the intermediate spaces are air-conditioned and evaporation taking place from the web W is promoted. The faces of drying cylinders 10 are kept clean by doctors 14.
Further, in the embodiments of the invention shown in FIGS. 3-9, the finishing section includes a machine reel-up 50, such as a Pope-type reel-up. The machine reel that is being made by means of the reel-up 50 is denoted by reference MRo, and one complete machine reel is denoted by reference MR. The web W is brought to the machine reel-up 50 through a calender 40 from an after-dryer 30 over guide and alignment rolls 35,45,46,47. After the last guide/alignment roll 47, a measurement device 48 is arranged to measure the properties of the web W before reeling. The calender 40 may be favorably a so-called soft calender, in which one roll can be heated and the other roll has a soft coating. Of course, the calender may also consist of two hard rolls. There may also be several calender nips.
In FIG. 3, in order to control the curl, a steam box 81 is positioned on the run of the web W between the guide/alignment rolls 46,47, in which case, the curl is affected after the calendering process and before the reel-up 50. If it is desired to control the tendency of curling efficiently in both directions, a steam box 81A or equivalent steam and/or moisture applicator device can also be arranged above the web.
In FIG. 4, a steam box 82 is arranged between the alignment/guide rolls 45 and 46, and the steam box 81 is arranged on the run of the web between the alignment/guide rolls 46,47, the control of the curl of the web being affected by means of both steam boxes on the run of the web W between the calender 40 and the reel-up 50.
In FIG. 5, in addition to the steam box 81 arranged on the run between the alignment/guide rolls 46,47, a steam box 83 is arranged in connection with the paper reel MRo that is being formed, in which case, besides in connection with the run of the web between the calender 40 and the reel-up 50, the control of the curl is also affected in connection with the making of the reel MRo that is being formed. Thus, in connection with the reel MRo that is being formed, steam box 83 is arranged and which can be displaceable, which is illustrated by the arrow S 83 . The steam box 83 is shifted as the reel size becomes larger when the reeling proceeds.
In FIG. 6, in connection with the reel MRo that is being formed, two steam boxes 83,84 are arranged, both of which are displaceable (the displaceability being illustrated by arrows S 83 ,S 84 ) as the reel size is increased with the progress of the reeling. In order to provide regulation of curl from the top side, of course, also in this connection, it is possible to use a steam or moistening device 81 A arranged above the web.
In FIG. 7, besides the steam box 81 arranged on the run of the web W between the alignment/guide rolls 46,47, a web W moistening device 85 is arranged on the run of the web W between the alignment/guide rolls 45,46. In this case, the curl of the web W is controlled after the calender 40 and before the reel-up 50 both by means of a moistening treatment and by means of a steam treatment.
In FIG. 8, with a view toward controlling the curl after the calender 40, a moistening device 86 is arranged on the run of the web W between the alignment/guide rolls 46,47. FIG. 8 also shows an IR dryer 87 by whose means an impulse of thermal energy can be applied to the top face of the web so as to affect the tendency of curling of the ultimate paper product. Instead of IR drying, it is also possible to use some other dryer device. Likewise, such drying devices can be placed at both sides of the web to be operative against both sides of the web. Regulation of curl by means of one-sided additional drying can be employed either alone or in combination with steam-treatment and/or moistening devices.
In the exemplifying embodiment shown in FIG. 9, moistening devices 85,86 are arranged on the runs of the web W between the alignment/guide rolls 45,46 and 46,47 so as to control the curl of the web W after completion of calendering before the reel-up 50. Of course, it is also possible to employ one moistening device only, or the moistening devices can be placed at opposite sides of the web.
In the exemplifying embodiment shown in FIG. 10, the regulation of curl is carried out in connection with a supercalender 110. The web W runs from an unwind stand 100 to the top portion of the supercalender 110 and from the bottom portion of the supercalender 110 further to a reel-up 120. The supercalender 110 consists of a vertical stack of rolls, in which the web W glazing nips consist of a hard-faced and a soft-faced roll. In the figure, a few possible positions (91,92,93,94,95,96) are indicated in which it is possible to employ steam boxes and/or moistening devices and/or devices that heat the web face intensively. Thus, the devices can be placed on the run (91,92) of the web W between the unwind stand 100 and the supercalender 110 and/or in connection with the take-out leading rolls 111 in the supercalender 110 (93,94) and/or on the run of the web W between the supercalender 110 and the reel-up 120 (95,96).
Above, some preferred embodiments of the invention have been described, and it is obvious to a person skilled in the art that numerous modifications can be made to these embodiments within the scope of the inventive idea defined in the accompanying patent claims. As such, the examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims. For example, the features suggested in the different exemplifying embodiments of the invention may be combined in a number of different ways for the purpose of controlling the curl of the web. Of course, in accordance with the invention, after the calendering process, it is also possible to use other arrangements in themselves known to a person skilled in the art in order to control the curl.
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A method for controlling the curl of paper in which steam treatment and/or moistening of the paper web is/are carried out after the calendering process being performed in the calender. In processes in which calendering is not employed, the curl is controlled in connection with a machine reel-up or in process steps carried out after the machine reel-up. A paper or board machine applying the method includes a headbox, a former, a press, a dryer section and steam boxes, moistening devices, an IR dryer and/or equivalent curl control devices. The steam boxes, moistening devices, IR dryers and/or equivalent curl control devices for the control of the curl are arranged after the calender or, if no calender is employed, in connection with a machine reel-up or a finishing process carried out after the machine reel-up.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to x-ray beam hardening filters and methods for making the same.
2. Background
X-ray sources used in medical imaging are typically polychromatic, that is, the x-ray source produces x-ray photons with varying energies. For example, an x-ray source capable of producing a 120 keV photon will typically produce an x-ray beam having a mean energy of only one-third to one-half of the peak energy. Given that the mean energy is roughly one-half to one-third of the peak energy, many of the photons that comprise an x-ray beam will be characterized by energy levels below the mean energy.
A problem with lower energy photons is that they do not contribute to the construction of the radiographic image. Many of the lower energy photons, for example those with energies less than 20 keV, may be absorbed in the object under investigation; these lower energy photons only contribute to harmful patient radiation. Therefore, it is desirable to filter the lower energy x-ray photons from the x-ray beam.
It is known to use filters to remove lower energy photons from the x-ray beam. One form of filtration is inherent filtration. Inherent filtration results from the absorption of x-ray photons as they pass through the x-ray tube and its housing. Such filtration varies with the composition, or lining of the x-ray tube and housing, as well as the length of the x-ray tube and housing. Inherent filtration, which is measured in aluminum equivalents, typically varies between 0.5 and 1.0 mm aluminum equivalent.
A second form of filtration is added filtration. Added filtration is achieved by placing an x-ray attenuator or filter in the path of the x-ray beam. Most materials have the property of attenuating the lower energy photons more strongly than higher energy photons. When lower energy x-ray beams strike the added filter they are absorbed. By adding a filter to the x-ray beam path, lower energy x-ray photons can be absorbed, thereby reducing the unnecessary radiation created by the lower energy x-ray photons. Because the lower energy x-ray photons are preferentially removed from the x-ray beam, the mean energy of the x-ray beam is increased. Increasing the mean energy of the x-ray beam is referred to as "hardening" of the x-ray beam.
Objects to be x-rayed vary in thickness and composition. Thus, it is desirable to control the amount of filtration that occurs. Some x-ray systems, having a relatively small diameter x-ray source, often use a filter consisting of a thin sheet of aluminum or aluminum and copper. The filter is placed in the path of the x-ray beam, either manually or by an electromechanical actuator. Because of the small diameter of the x-ray source, the filter and filter control mechanism can be made compact.
However, when a large-area x-ray source (e.g., having a diameter of approximately 25 cm or larger) is used in an x-ray imaging system and if added filtration is used, the beam hardening filter inserted into the path of the x-ray beam would be as large as the overall x-ray source in order to cover the entire source. Furthermore, the mechanical travel of the filter to insert it into the path of the x-ray beam would also be about the same as the size of the x-ray source (e.g., 25 cm) or the filter. Using a conventional x-ray hardening filter, for example one that slides in a parallel plane to the surface of the x-ray source, on a large-area x-ray source would involve a large mechanical actuator assembly and would add undesirable bulk to the x-ray imaging system.
SUMMARY OF THE INVENTION
The present invention comprises a method for making a novel x-ray beam hardening filter and assembly, comprising etching a plurality of pits into a sheet having an x-ray hardening quality, aligning the sheet and a support member to a reference point, and bonding the sheet to a support member. In another embodiment, the method further comprises, aligning the plurality of pits with a plurality of collimator apertures, reaming the plurality of pits to a finished size, and removing burs from the support member.
As a result of the method for making the x-ray beam hardening filter disclosed herein, an x-ray beam hardening filter comprising a beam hardening sheet, the beam hardening sheet having a plurality of pits, and a support member can be made and used which is useful in diagnostic x-ray imaging, especially for filtering harmful x-ray radiation which does not contribute to an x-ray image.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 depicts an x-ray beam hardening filter;
FIG. 2 depicts a support member for an x-ray beam hardening filter;
FIG. 3A is a detail schematic of a top portion of a support member;
FIG. 3B is a detail schematic of a bottom portion of a support member;
FIG. 3C is a detail schematic of a side portion of a support member; and
FIG. 4 is cross-sectional view of a collimator assembly having an x-ray beam hardening filter according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The specification and drawings described in detail herein are related to copending U.S. patent application Ser. Nos. 09/167,639, 09/167,399, filed on the same day herewith, and U.S. Pat. No. 5,610,967, all of which are incorporated herein by reference in their entirety.
FIG. 1 depicts a preferred construction of an x-ray beam hardening filter 100. The x-ray beam hardening filter 100 comprises a filter plate or "support member" 110, as it is referred to herein, and a sheet having a beam hardening quality. As used herein, the sheet having a beam hardening quality is referred to as a "beam hardening sheet" 120. The beam hardening sheet 120 preferably comprises a plurality of pits. The areas of the beam hardening sheet without pits are configured to cause certain energy levels of x-ray radiation from a polychromatic x-ray beam incident thereon to be absorbed (or filtered), whereas the plurality of pits are configured to not to filter the x-ray radiation. The x-ray beam hardening filter 100 therefore is capable of shaping the energy spectrum envelope of the polychromatic x-ray beam such that certain energy levels of harmful radiation are selectively removed.
The support member 110 is preferably manufactured from stainless steel. Furthermore, the support member 110 is initially larger than washer-shaped article depicted in FIG. 1, for it includes an etching plate 140, which can be removed after bonding a beam hardening sheet 120 to the support member 110, or, later still, after aligning the x-ray beam hardening filter 100 to a collimator assembly.
The outer diameter of the relevant portion of the support member 110 is approximately 10.27 inches, while the inner diameter of the support member 110 is approximately 9.800 inches. The upper and lower portions of the support member 110, that is bottom portion 150 and top portion 160, have a flattened edge 112 extending inward from the outer diameter to a distance 4.512 inches from the x-centerline 102. The side portion 155 also has a flattened portion 112 which extends inward from the outer diameter to a distance of 4.512 inches from the y-centerline 104.
The outer edge of the support member 110 is defined by a number of connector openings 180 that permit unobstructed movement of the x-ray beam hardening filter 100 within (or over) a collimator (described in greater detail below with reference to FIG. 4). Both the top and bottom edges, 160 and 150, of the support member 110 comprise direction guides 192 which guide the motion of the support member in straight path. The direction guides 192 have a width of 0.110 inches.
A receiver, or an "actuator aperture" 194, as it is referred to herein, is formed on the top edge 160 of the support member 110. The actuator aperture 194 surrounds an actuator (not shown) which provides a force to move that support member 110 in the straight path defined by direction guides 192. The bottom edge 150 of the support member 110 does not have an actuator aperture 194. The bottom edge 150 instead has a rectangular shaped opening 152. Within the rectangular shaped opening 152 is a break away alignment tab 154. Two additional alignment tabs 154 are also depicted in FIG. 1.
FIG. 2 depicts the support member 110 without the beam hardening sheet 120.
FIG. 3A depicts the top edge 160 of the support member 110, and FIG. 3B depicts the bottom edge 150 of the same. Actuator aperture 194 and alignment slot 172 are depicted in the top edge 160. Alignment slot 172 is 0.110 (±0.002) circular mils. It is preferred that the alignment slot 172 is within 0.002 inches of the true position of the apertures 156 in the break away tabs 154. The actuator aperture 194 preferably has a generally rectangular shape with a height of approximately 0.220 inches, a width of approximately 0.695 inches, and rounded comers with a radius of approximately 0.046 inches. At approximately 0.520 inches from the left side of the rectangle (as depicted in FIG. 3A), near both the top and bottom edges of the rectangle, two circular extensions are carved from the actuator aperture 194. The radius of the two circular extensions is 0.175 inches. The actuator aperture 194 can vary in size and shape, however, it is important that it still allow for movement of an actuator therein, the actuator used to move the beam hardening filter 100 into or out of the path of a polychromatic x-ray beam.
FIG. 3B depicts the bottom edge 150 of the support member 110. The rectangular ledge 152 carved from the support member 110 is begins approximately 0.338 inches from left of the y-centerline 104 and down approximately 4.623 inches from the intersection of the x- and y-centerlines 102 and 104. An alignment tab 154 connects to two sides of the ledge 152. The alignment tab 154 is configured to break away from the support member 110. An alignment aperture 156, measuring 0.047 circular mils, is located on the alignment tab 154. Similar alignment apertures 156 are located on the left and right side of the support member 110 on the x- and y-centerlines 102 and 104.
FIG. 3C depicts a break away tab 154 and alignment aperture 156 which is located on the right side 155 of the support member 110. The break away tab 154 has a radius of 0.100 inches, which is the same as the radius of the alignment tab 154 depicted with reference to FIG. 3B. Again, an alignment aperture 156 is located at the center point of the alignment tab 154.
Returning again to FIG. 1, according to a presently preferred embodiment, a method for making the x-ray beam hardening filter comprises the steps described below. First, a plurality of areas having a different x-ray absorption quality than the beam hardening sheet 120 are chemically etched into the surface of the beryllium (Be) and copper (Cu) beam hardening sheet 120. The result of the etching is a plurality of pits 130 that are regularly spaced about the surface area of the beam hardening sheet 120.
The pits 130 are preferably 0.036 (±0.002) circular mils, and are spaced and shaped according to the parameters defined in Table 1. Furthermore, the pits 130 are symmetrical with the x- and y- centerlines 102 and 104 respectively, with a center of a single pit placed at the intersection of the centerlines 102 and 104. Thus, according to a preferred embodiment, the plurality of pits form a multidimensional array of uniformly sized and spaced pits in the surface area of the beam hardening sheet 120.
TABLE 1______________________________________Beam Hardening Filter Pit Spacing (inches & circular mils)Sheet ReductionThickness Level Hole Pitch Hole Size______________________________________0.004 0.990636 0.89703 0.036 (±0.002)0.008 0.990043 0.89650 0.036 (±0.002)______________________________________
An advantage of the present invention is that when uniformly spaced and sized pits 130 are employed, and they are spaced according to Table 1 above, then the movement of the beam hardening sheet need only be a distance approximately equal to one-half the hole pitch, or the spacing between two adjacent pits in the beam hardening sheet. In other embodiments, movement of the beam hardening sheet 120 may follow a curved path and the movement can be restricted to approximately three times the distance between two adjacent areas of equal x-ray absorption. This unique feature allows for a minimal amount of movement of the beam hardening sheet 120 to vary the x-ray absorption quality of the beam hardening filter 100.
In the next step, the support member 110 and the beam hardening sheet 120 are aligned. The alignment is accomplished with the aid of one or more alignment elements. In a preferred embodiment, the beam hardening sheet 120 is first placed on a surface (e.g., a jig) and support member 110 is placed over it. The beam hardening sheet 120 and the support member are aligned to a reference position, namely the alignment slots 170 (having a diameter of 0.125 inches) which are formed into the etching blank 140 and the beam hardening sheet 120.
Once the beam hardening sheet 120 and the support member 110 are aligned, they are bonded together. The bonding step comprises applying a 95% tin and a 5% silver brazing paste between the top of the beam hardening sheet 120 and the bottom of the support member 110, followed by heating the brazing paste to approximately 480 F in a hydrogen atmosphere. Preferably, none of the solder overlaps any of the pits 130. To accomplish this, the brazing paste may be blown from the active area of the sheet before the step of heating with a fan. Furthermore, the beam hardening sheet 120 and support member 110 are clamped together to prevent movement which may cause misalignment before the step of bonding.
It is important not to overheat the brazing paste, and consequently the x-ray beam hardening filter, because there is a chance it will warp. Furthermore, the heating step is preferably performed in a furnace.
According to one embodiment, the x-ray beam hardening filter 100 components (e.g., beam hardening sheet 120 and support member 110) are electroplated before the step of bonding.
Now that the beam hardening sheet 120 has been bonded to the support member 110, another alignment step is performed. Referring to FIG. 4, the x-ray beam hardening filter 100 is placed over a collimator 404 such that the pits 130 align with collimator apertures 436 in the collimator 404. The alignment is facilitated again by alignment slots 170, which can be placed over a jig or alignment pins, alignment slots 172, through which an alignment pin 408 can pass, as well as with the aid of alignment apertures 156 in alignment tabs 154.
Once the pits 130 are aligned, the direction guides 192 are reamed to their preferred size. A final inspection is made of the alignment of the pits 130 with the collimator apertures 436. If alignment is confirmed, then the alignment slots 172 are machined and the etching blank 140 and alignment tabs 154 are removed from the support member 110.
The x-ray beam hardening filter 100 can then be removed from the collimator 404. Burs are preferably ground from the edges of the support member 110. A lubricant is applied to the surfaces of the finished x-ray beam hardening filter 100. According to one embodiment, a dry film lubricant is used. A presently preferred dry film lubricant is Dicronite® made by Dricronite® Dry Lube Northwest, and which is available from CLS, Inc, in Santa Clara, Calif.
Turning again to FIG. 4, one or more x-ray beam hardening filters 416 are placed within a collimator assembly 400. Mounting pins 412 tie the collimator 404 to the collimator cover 432. Spacers, e.g., spacer 428, create a void between the collimator 404 and the collimator cover 432 in which the one or more beam hardening filters 416 can move, aided by an actuator 420 having a cam bearing 424, while pressure is maintained around the collimator cover 432 and collimator 404.
In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will be evident, however, that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. For example, the dimensions and sizes of the various components can be altered and different materials substituted for the construction thereof. Furthermore, the spacing of the pits does not have to be uniform, nor do the pits themselves need to be of a uniform size or shape. The specification and drawings are, accordingly, to be regarded in an illustrative, rather than a restrictive sense.
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An x-ray beam hardening filter and method for making the same is disclosed. According to an embodiment, the method comprises etching a plurality of regularly spaced pits into a surface area of a sheet having an x-ray beam hardening quality, aligning the sheet to a support member and bonding the sheet to the support member. An x-ray beam hardening filter can be made and used which is not only compact and useful in diagnostic x-ray imaging, but which is capable of shaping an x-ray energy spectrum envelope in a highly controllable manner.
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BACKGROUND OF THE INVENTION
The most common method for the production of cyanoacrylate monomers involves the base catalyzed Knoevenagel condensation of cyanoacetate with formaldehyde, followed by acid catalyzed thermolysis of the intermediate polymer. This method is exemplified in many references, for instance U.S. Pat. Nos, 2,721,858; 3,254,111; 3,355,482; 3,654,340; 5,140,084 and 5,359,101. This method is effective and inexpensive in producing low molecular weight monomers, but as the size of the cyanoacrylate ester increases the method becomes more difficult and yields diminish substantially. Cyanoacrylate esters of monofunctional C 8 or higher aliphatic alcohols cannot be produced in commercially practical yields by this method.
There are several other synthetic methods known for producing cyanoacrylates including:
Diels-Alder protection/deprotection as exemplified by U.S. Pat. No. 3,463,804 and 4,012,402;
transesterification of cyanoacrylate monomers with alcohols as reported in WPI 80-82239C/46, abstracting (SU 726086 (1980));
direct esterification of cyanoacrylic acid with alcohols as reported in DE 34 15 181 (1984);
thermal decomposition of alkyl 2-cyano-3-alkoxypropionates and the 3-acyloxy analogs, reported in U.S. Pat. No. 2,467,926; and
pyrolysis of the cyanohydrin acetates of pyruvic acid esters, reported in U.S. Pat. No. 2,391,251.
Monomers having a plurality of cyanoacrylate groups per molecule are particularly desirable because they can give crosslinked products on polymerization, alone or in combination with conventional monofunctional cyanoacrylate monomers. Crosslinked polymers give improved properties such as solvent resistance. The Diels-Alder protection/deprotection disclosed in U.S. Pat. No. 4,012,402 has been used to prepare various bis-cyanoacrylate monomers. However, the method is cumbersome and not suited to commercial production.
Kadykov, et. al., "Synthesis and Properties of Siloxane Cyanoacrylate Adhesives," Plast. massy, 1984, No. 10, pp.8-9, reports an alleged syntheses of "diacryl-α-cyano-β-hydroxypropyldimethylsiloxane" by reaction of one mole diepoxydimethylsiloxane and two moles α-cyanoacrylic acid in the presence of 0.03 moles tertiary amine catalyst and 0.05 mole hydroquinone monomethyl ether. The reaction is reported to be exothermic and to produce the bis-ester of the formula: ##STR1##
However, the reaction conditions employed make it unlikely that such a product could actually be isolated and the analytical data reported in this reference on the product which was isolated is believed to confirm that the product was not the bis-cyanoacrylate.
There therefore exists a need for further alternative methods for cyanoacrylate ester production and in particular methods which can be used for production of monomers having plural cyanoacrylate functionality in reasonable yield and with less difficulty than that of U.S. Pat. No. 4,012,402.
In Reich, et al, JACS, 97, 5434-47 (1975) and Bucheister, et al, Organometallics, 1, 1679-84 (1982), it is reported that certain αβ-unsaturated methyl or ethyl esters were prepared by oxidation/elimination reactions performed on corresponding methyl or ethyl α-selenoarylpropionate esters. However it has not been previously proposed or suggested to try to use such procedure to prepare α-cyanoacrylate esters, nor has it been proposed or suggested to try to prepare esters of C 8 or higher alcohols or plural ester compounds by preparation and oxidation/elimination of α-selenoaryl-α-cyanopropionate esters.
SUMMARY OF THE INVENTION
The present invention is directed to a novel method for preparing cyanoacrylate monomers which can be used to prepare difficult to synthesize higher molecular weight cyanoacrylate monomers and plural functional cyanoacrylate monomers as well as more conventional monofunctional cyanoacrylate monomers in high yield and by a relatively simple procedure.
The invention in one aspect is a method of preparing an α-cyanoacrylate ester of a desired alcohol, the method comprising the steps of
preparing a compound which is an α-selenoaryl-α-cyanopropionate ester of said alcohol,
oxidizing said α-selenoaryl-α-cyanopropionate ester to the corresponding selenoxide,
eliminating arylselenic acid from said selenoxide to produce said α-cyanoacrylate ester, and
separating said α-cyanoacrylate ester from said arylselenic acid.
At temperatures of about 0° C. or higher, the elimination step occurs concurrently with the oxidizing step using a peroxide or ozone oxidizing agent. The desired cyanoacrylate ester is obtained in good yield and very high purity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the inventive method as described above, the α-selenoaryl-α-cyanopropionate ester is suitably prepared by treating a corresponding α-cyanopropionate ester with a base of sufficient strength to abstract an α-H atom from the cyanopropionate ester and adding an arylselenylhalide of the formula
Ar--Se--X
where Ar is an aryl group and X is Cl , Br or I.
The α-cyanopropionate ester of the desired alcohol can be prepared by known means. In general any means suitable for preparing α-cyanoacetate esters can be readily modified by known methods to prepare corresponding α-cyanopropropionate esters. Such methods include acid catalyzed direct esterification of cyanopropionic acid with an alcohol, optionally in the presence of 2-halopyridinium salts; base catalyzed alkylation reactions of cyanopropionic acid with alkyl halides; acid or base catalyzed transesterification reactions; nucleophilic substitution reactions where chloropropionates are treated with alkali cyanides in a direct cyanation reaction; and direct acylation reactions of alcohols with cyanopropionyl chloride.
The invention is particularly advantageous for preparing cyanoacrylate esters of C 8 or higher alcohols, including aliphatic and aromatic alcohols, for instance C 8 -C 22 hydrocarbon alcohols and alkoxylated hydrocarbon alcohols such as ethoxylated nonyl phenol and similar surfactant compounds. The inventive method can also be used to prepare plural functional cyanoacrylate compounds, i.e. from cyanopropionate esters of plural hydroxy functional compounds. Such plural hydroxy functional compounds can be simple diols, triols or tetraols such as ethylene glycol, propylene glycol, 1,3-propane diol, 1,4,-butanediol, trimethylolpropane, 1,6-hexanediol, pentaerythritol, diethylene glycol, tetraethylene glycol and the like or oligomeric prepolymer compounds such as polyethylene glycol, hydroxy terminated polybutadiene, hydroxy terminated polyesters and the like.
The arylselenyl halide is suitably prepared from a diaryldiselenide such as diphenyldiselenide by addition of the molecular halogen X 2 . Suitable Ar groups are substituted or unsubstituted phenyl groups. Suitable phenyl group substitutions include halo, alkyl, alkoxy and haloalkyl. Specific examples of substitutions include methyl, ethyl, phenyl, chloro, fluoro, trifluoromethyl, methoxy and ethoxy. Preferably X is Br.
Examples of bases of sufficient strength to abstract an α-H atom from the cyanopropionate ester include the alkali hydride bases NaH, KH, LiH, and alkylalkalides, such as n-butyllithium. Alkali hydride bases are preferred as the byproduct H 2 is removed continuously as a gas driving the reaction to completion. Alkali-amide bases, such as lithium diisopropyl amide, and alkoxide bases, such as sodium methoxide, are generally undesirable as they introduce additional amine or alcohol by-products which may be more difficult to completely remove during work-up of the α-selenoaryl-α-cyanopropionate ester.
Isolation and purification of the α-selenoaryl-α-cyanopropionate ester can usually be readily accomplished by dissolution in a suitable solvent such as ether (diethyl ether) and aqueous extraction of the solution followed by evaporation of the solvent. In general further purification is unnecessary but in some cases it can be beneficial. Further purification can for instance crystallization, suitably from a cooled ether solution.
The cyanoacrylate ester is formed by an oxidation/elimination reaction. The mechanism is believed to involve two steps which occur concurrently at ambient temperature but which can be separated into two stages if the oxidation is carried out at temperatures no higher than about 0° C. Reaction at temperatures above 0° C. is preferred as there is no benefit to isolating the intermediate selenoxide product of the oxidation reaction. Temperatures is excess of about 40° C. are also preferably avoided because the cyanoacrylate product may polymerize at elevated temperatures and because the reaction is highly exothermic and can become difficult to control at higher temperatures.
Suitable oxidizing agents are peroxide compounds and ozone. Hydrogen peroxide is generally preferred as it is inexpensive, effective and relatively easy to handle. Other oxidizing agents which may be particularly useful in some circumstances include m-chloroperbenzoic acid and sodium iodate.
The oxidation reaction is suitably carried out in a two phase reaction in which the α-selenoaryl-α-cyanopropionate ester is dissolved in a hydrophobic solvent such as methylene chloride, and the hydrogen peroxide is added as a solution in water, the two phases being vigorously agitated to effect reaction between the reactants in the respective phases.
At temperatures above about 0° C. elimination of the aryl selenic acid occurs spontaneously without added reactant or catalyst to yield the desired cyanoacrylate ester. The aromatic selenic acid is insoluble in common organic solvents and so is readily separated from the cyanoacrylate. In the case of the two-phase reaction described above separation of the cyanoacrylate ester is accomplished simply by separation of the organic layer.
The arylselenic acid byproduct of the reaction can be recycled by reduction to the corresponding diaryldiselenide in accordance with the known method described in the Reich et.al. reference described above, followed by conversion of the diaryldiselenide to a selenoaryl halide by reaction with chlorine, bromine or iodine.
EXAMPLES
Ethyl cyanopropionate was obtained from TCI America and was used without further purification. Diphenyl diselenide was purchased from Aldrich or Janssen and was recrystallized from ethanol prior to use. THF was distilled from sodium/benzophenone immediately before use. Sodium hydride was purchased from Aldrich as a 95% powder and was stored in a desiccator.
Reaction glassware was oven dried before use. All glassware was immersed overnight in 0.5M H 2 SO 4 , rinsed with deionized water and oven dried. All transfers of dried solvents were performed with a syringe.
Proton NMR spectra were obtained on a Varian Gemini 300 MHZ NMR spectrometer. IR analyses were done on an ATI Mattson Genesis Series FTIR.
EXAMPLE 1
PREPARATION OF 2-OCTYL CYANOACRYLATE
The method of this example may be represented by the following equation: ##STR2##
PHENYLSELENIUM BROMIDE
To a 3-neck 250 ml flask, equipped with a nitrogen inlet, magnetic stirrer, and rubber septum, was added diphenyl diselenide (20.9 g, 67 mmol) and THF (100 ml) under nitrogen. Bromine (9.8 g, 61 mmol) was added by syringe. The solution was stirred for 5 minutes.
2-Octyl Cyanopropionate phenylselenide (1)
To a 4-neck 500 ml flask, equipped with a condenser, mechanical stirrer, thermometer, and nitrogen inlet, was added sodium hydride (3.9 g, 153 mmol) and THF (250 ml) under nitrogen. 2-octyl-2-cyanopropionate (20 g, 115 mmol) was added over 10 min. and the reaction mixture was stirred for 1 hour at room temperature. A solution of phenylselenium bromide, prepared by the above method, was added by syringe. The reaction mixture was stirred for 1 hour and added to 250 ml each of ether and sat. aq. NaHCO 3 . The organic layer was washed twice with 250 ml of H 2 O and once with 250 ml sat. aq. NaCl. The organic layer was separated, dried (MgSO 4 ) and filtered. Solvent was removed under reduced pressure. Yield=43.2 g (quant.); NMR δ (CDCl 3 ) 7.75 (d, 2H), 7.40 (m, 3H), 4.85 (m, 2H), 1.80 (s, 3H), 0.8-1.70 (m, 16H); IR (neat) 2333, 1734, 1251 cm -1 .
2-Octyl Cyanoacrylate (2)
To a 500 ml flask, equipped with a condenser, mechanical stirrer, thermometer, and addition funnel, was added the crude 2-octyl propionate phenylselenide (43.2 g, 115 mmol) and methylene chloride (300 ml). Hydrogen peroxide, 30% (47 g, 418 mmol) was dissolved in water (30 ml) and added to the reaction flask over 15 minutes. The reaction temperature was kept at 20°-30° C. with an ice bath. After the addition was complete, the reaction mixture was stirred for 1 hour at room temperature. The organic layer was separated and washed once with 100 ml of H 2 O. The organic layer was separated, dried (anhydr. silicic acid), and filtered. Solvent was removed under reduced pressure. The crude product was distilled under vacuum. Yield=14.4 g (60%), B.P.=95° C./1.0 mm Hg; NMR δ (CDCl 3 ) 7.05 (s, 1H), 6.60 (s, 1H), 5.05 (m, 2H), 0.8-1.7 (m, 16H); IR (neat) 2236, 1732, 1649, 1287 cm -1 ; strong acid ≦1 ppm.
EXAMPLE 2
Preparation of 1,4 Butanediol dicyanoacrylate (BDDCA) 1,4 Butanediol dicyanopropionate
To a 1000 ml 3-neck flask equipped with a Dean-Stark trap, condenser, thermometer, and nitrogen inlet, was added ethyl-2-cyanopropionate (50.8 g, 400 mmol), 1,4 butanediol (15.8 g, 175 mmol), p-toluenesulfonic acid (3 g, 16 mmol), and toluene (500 ml) under nitrogen. The solution was heated to reflux with stirring. Solvent was removed through the Dean-Stark trap and replaced with an equal volume of fresh toluene. After refluxing for 8 hours, and removing 500 ml of solvent, the solution was cooled to room temperature. The solution was washed twice with 300 ml of sat. aq. NaHCO 3 , twice with 300 ml of H 2 O, and once with 300 ml of sat. aq. NaCl . The organic layer was separated, dried (MgSO 4 ), and filtered. Solvent was removed under reduced pressure. The crude product was purified by vacuum distillation. Yield=22.3 g (51%), B.P.=172° C. (0.6 mm/Hg); NMR δ(CDCl 3 ) 4.25 (br t, 4H), 3.60 (q, 2H), 1.80 (br t, 4H), 1.60 (d, 6H); IR (neat) 2252, 1745 cm -1 .
PHENYLSELENIUM BROMIDE
To a 3-neck 250 ml flask, equipped with a nitrogen inlet, magnetic stirrer, and rubber septum, was added diphenyl diselenide (17.2 g, 55 mmol) and THF (100 ml) under nitrogen. Bromine (7.2 g, 45 mmol) was added by syringe. The solution was stirred for 5 min.
1,4 Butanediol dicyanopropionate bis-phenylselenide
To a 500 ml 4-neck flask, equipped with a condenser, mechanical stirrer, thermometer, rubber septum, and nitrogen inlet was added sodium hydride (2.7 g, 105 mmol) and anhydrous dimethyl formamide (200 ml) under nitrogen. Butanediol dicyanopropionate (10 g, 40 mmol) was added over 10 min. at room temperature, and the reaction mixture was stirred for 2 hours. The previously prepared phenylselenium bromide solution was added by syringe and the reaction mixture was stirred for 2.5 hours. The reaction mixture was added to 250 ml each of ether and sat. aq. NaHCO 3 . The organic layer was washed twice with 250 ml of H 2 O and once with 250 ml of sat. aq. NaCl . The organic layer was separated, dried (MgSO 4 ), and filtered. Solvent was removed under reduced pressure. Crude Yield=23.4 g (quant.). To the crude product was added 10 ml of ether and the mixture was cooled in an ice bath. The bis-phenylselenide precipitated, was filtered, and washed with 5 ml of cold ether. Yield =6.5 g (29%), M.P.=113° C.; NMR δ (CDCl 3 ) 7.75 (d, 4H), 7.40 (m, 6H), 3.95 (m, 4H), 1.85 (s, 6H), 1.40 (br s, 4H); IR (KBr) 2231, 1730, 1234 cm -1 .
1,4 Butanediol dicyanoacrylate (BDDCA)
To a 250 ml flask, equipped with a condenser, mechanical stirrer, thermometer, and addition funnel, was added bis-phenyselenide (6.5 g, 12 mmol) and methylene chloride (50 ml). Hydrogen peroxide, 30% (11.6 g, 102 mmol) was dissolved in water (8 ml) and added slowly to the reaction flask over 10 min. The temperature was maintained at 20°-30° C. with an ice bath. After the addition was complete, the reaction mixture was stirred for 2 hours at room temperature. The organic layer was separated and washed with 50 ml of water The organic layer was separated, dried (anhydr. silicic acid) and filtered into a flask containing 0.015 g of methanesulfonic acid. The solution was condensed under reduced pressure. Because of its reactivity, BDDCA was kept as a solution until just prior to use. Solvent was evaporated under vacuum in a desiccator from a plastic beaker, which had been immersed overnight in 0.5M H 2 SO 4 , washed with deionized water and dried. The solid BDDCA is extremely reactive and was used immediately after evaporation of solvent, because it polymerized within a few minutes in the solid state. M.P.=80° C.; NMR δ (CDCl 3 ) 7.10 δ(s, 2H), 6.65 (s, 2H), 4.35 (br t, 4H), 1.90 (br t, 4H); IR (KBr) 3.32 2237, 1729, 1615 cm -1 . TGA analysis showed that BDDCA homopolymer decomposed at about 65 ° C. higher than ethyl cyanoacrylate homopolymer. Polymerized mixtures of BDDCA at levels of 1, 5, 10 and 20 parts per hundred in ethyl cyanoacrylate, did not show any enhancement of thermal stability over the ethyl cyanoacrylate homopolymer but did give significant solvent swelling resistance on immersion in methylene chloride overnight.
EXAMPLES 3-7
When example 1 is repeated except that equivalent amounts of phenyl 2-cyanopropionate, 4-ethylphenyl cyanopropionate, n-octyl cyanopropionate, 4-nonylphenyl 2-cyanopropionate and stearyl 2-cyanopropionate are substituted in separate respective experimental runs for the starting 2-octyl 2-cyanopropionate used in example 1 and appropriate equivalent weight adjustments are made throughout the procedure, phenyl cyanoacrylate, 4-ethylphenyl cyanoacrylate, n-octyl cyanoacrylate, 4-nonylphenyl cyanoacrylate and stearyl cyanoacrylate, respectively will be obtained in reasonable purity at the end of the procedure.
EXAMPLES 8-12
When example 2 is repeated except that an equivalent amount of the 2-cyanopropionate esters of the following polyols are substituted in separate experimental runs for the starting 1,4-butane diol dicyanopropionate used in example 2 and appropriate equivalent weight adjustments are made throughout the procedures, the corresponding plural cyanoacrylate will be obtained in at the end of the procedure:
bis-hydroxy terminated polyethylene glycol 400;
bis-hydroxy terminated polyethylene glycol 1000;
bis-hydroxy terminated polybutadiene;
bis-hydroxy terminated mixed ortho and para phthalate/diethylene glycol polyester;
tris-hydroxy terminated adipate/1,4-butane diol-glycerine polyester (1 eq glycerol per molecule.
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A method of preparing an α-cyanoacrylate ester of a desired alcohol includes the steps of
preparing a compound which is an α-selenoaryl-α-cyanopropionate ester of the desired alcohol,
oxidizing said α-selenoaryl-α-cyanopropionate ester to the corresponding selenoxide,
eliminating arylselenic acid from the selenoxide to produce said α-cyanoacrylate ester, and
separating said α-cyanoacrylate ester from the selenic acid.
At temperatures of about 0° C. or higher, the elimination step occurs concurrently with the oxidizing step using a peroxide or ozone oxidizing agent. The desired cyanoacrylate ester is obtained in good yield and very high purity. The method can be used to prepare difficult to synthesize plural functional cyanoacrylate monomers and mono- cyanoacrylate monomers regardless of alcohol chain length.
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RELATED APPLICATIONS
The present application is related to and claims the benefit of priority from French Patent Application No. 04 53225, filed on Dec. 24, 2004, the entirety of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a composition for a material which is capable of resisting extreme heat conditions.
The invention finds particularly advantageous but not exclusive application in the field of power or telecommunications cables which are intended to remain operational for a predetermined period of time when they are subjected to strong heat and/or direct flame.
BACKGROUND OF THE INVENTION
One of the major current challenges to the cable industry lies in improving the behavior and performance of cables under extreme heat conditions, in particular those encountered during the course of a fire. Mainly for safety reasons, it is vital to maximize the capacity of a cable both to retard the propagation of flames, and to resist the fire. Significantly slowing the advance of flames increases the time available for evacuation of sites and/or for using appropriate extinguisher means. Better fire resistance means that the cable can function longer, since it degrades more slowly. A safety cable must also not be dangerous to the environment, i.e. it must not release toxic fumes and/or fumes that are too dense when it is subjected to extreme heat conditions.
Whether electrical or optical, intended for power transport or for data transmission, a cable is constituted in outline by at least one conductor element extending inside at least one insulating element. It should be noted that at least one of the insulating elements may also act as a protective means and/or the cable may further comprise at least one specific protective element, forming a sheath. However, many of the best insulating and/or protective materials used in the cable industry are unfortunately highly flammable. This is particularly the case with polyolefins and their copolymers, such as polyethylene, polypropylene, copolymers of ethylene and vinyl acetate, and copolymers of ethylene and propylene. At all events, in practice, such excessive flammability proves to be completely incompatible with the fire performance requirements mentioned above.
Many methods exist in the cable industry for improving the fire performance of polymers used as insulating and/or sheathing materials.
Until now, the most popular solution has consisted in using halogenated compounds in the form of a halogenated derivative dispersed in a polymer matrix or directly in the form of a halogenated polymer, as is the case with a PVC, for example. However, regulations are now tending towards prohibiting the use of that type of substance, mainly because of their toxicity and their potential corrosivity, whether on manufacture of the material or during its decomposition by fire. This is the case both when the decomposition in question occurs unintentionally during a fire and also when it is intentionally incinerated. Whatever the case, recycling halogenated materials remains a particular problem.
For this reason, more and more non halogenated fire retardant fillers are being used, in particular metallic hydroxides such as aluminum hydroxide or magnesium hydroxide. Unfortunately, that type of technical solution suffers from the disadvantage of requiring large quantities of fillers to be satisfactory, either in terms of flame propagation retarding capacity or of fire resistance. As an example, the metallic hydroxide content can typically be 150 to 200 parts by weight per 100 parts by weight of polymer resin.
However, any bulk incorporation of a filler causes a considerable increase in the viscosity of the material which receives it. This then inevitably generates a substantial reduction in the extrusion rate, and consequently a significant reduction in productivity, which is unfortunately reflected in the cost price of the composite material.
However, independently of this process aspect, non halogenated fire retardant fillers have in any event proved to be intrinsically relatively expensive. And since they have to be used in large quantities, the cost of the materials in which they are dispersed is further increased.
OBJECTS AND SUMMARY OF THE INVENTION
Thus, the technical problem to be solved by the present invention is to propose a fire resistant composition, in particular for a power and/or telecommunications cable material, said composition comprising a polymer and a fire retardant filler, which composition can overcome the problems of the prior art and in particular be cheaper, while guaranteeing good fire performance.
In accordance with the present invention, the solution to the technical problem consists in that the polymer is thermoplastic in type, and in that the fire retardant filler comprises cork.
It should be pointed out that the term “thermoplastic type polymer” designates both a thermoplastic polymer and a thermoplastic elastomer polymer, and that the cork may be in any form which is capable of being dispersed in the polymer matrix.
In any event, the invention as defined has the advantage of having a particularly low cost price because of the extremely low cost of its fire retardant filler, especially when compared with that of conventional prior art fillers. This constitutes a major economic advantage in the cable industry, since it will encourage the market penetration of fire retardant cables.
When also considering the fact that the use of a cork-based fire retardant filler can also substantially improve the fire performance of a polymer material over that of corresponding prior art materials, it then becomes clear that a composition of the invention has a price/performance advantage.
In a currently preferred implementation of the invention, the cork in the fire retardant filler is in powder form.
It should be understood that the term “powder” is used herein very generally to designate any solid substance divided into very small homogeneous particles. This means that the particles in question may be have any shape, and not necessarily that of grains. This includes fibers.
In any event, and particularly advantageously, the powdered cork has a grain size of less than 600 micrometers (μm), preferably less than 200 μm.
In accordance with a feature of the invention, the polymer is selected from a polyethylene, a polypropylene, a copolymer of ethylene and propylene (EPR), an ethylene-propylene-diene terpolymer (EPDM), a copolymer of ethylene and vinyl acetate (EVA), a copolymer of ethylene and methyl acrylate (EMA), a copolymer of ethylene and ethyl acrylate (EEA), a copolymer of ethylene and butyl acrylate (EBA), a copolymer of ethylene and octene, a polymer based on ethylene, a polymer based on polypropylene, a polyetherimide, a thermoplastic polyurethane, a polyester, a polyamide, or any mixture of said components.
In accordance with a further advantageous feature of the invention, the composition comprises 5 to 100 parts by weight of fire retardant filler per 100 parts by weight of polymer, preferably 10 to 30 parts by weight of fire retardant filler.
In accordance with a further feature of the invention, the composition is further provided with at least one secondary fire retardant filler.
Particularly advantageously, each secondary fire retardant filler is selected from phosphorus-containing compounds such as organic or inorganic phosphates, antimony-containing compounds such as antimony oxide, metallic hydroxides such as aluminum hydroxide and magnesium hydroxide, boron-based compounds such as borates, carbonates of alkali metals from groups IA and IIA such as calcium, sodium, potassium, or magnesium carbonates and the corresponding hydroxycarbonates, tin-based compounds such as stannates and hydroxystannates, melamine and its derivatives such as melamine phosphates, and formophenolic resins.
In accordance with a still further feature of the invention, the composition is also provided with at least one additive selected from the group formed by pigments, antioxidants, and ultraviolet stabilizers, as well as processing aids such as lubricants, plasticizers, and heat stabilizers.
The invention also provides any cable comprising at least one conductive element extending inside at least one insulating covering, with at least one insulating covering of the cable being produced from a composition as described above.
The invention also provides any cable provided with at least one conductive element extending inside at least one insulating covering, and further comprising at least one protective sheath produced from a composition as described above.
It should be noted that the term “conductive element” designates both an electrical conductor and an optical conductor. Further, and in all cases, the cable may equally well be an electrical cable or an optical cable, in particular intended for power transport and/or for data transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a heat release rate chart for samples 1 through 5, in accordance with one embodiment of the present invention;
FIG. 2 is a heat release rate chart for samples 1 and 6 through 9, in accordance with one embodiment of the present invention; and
FIG. 3 is a heat release rate chart for samples 1 and 10 through 13, in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
Other characteristics and advantages of the present invention will become clear from the following description of examples which are given by way of non limiting illustration.
Examples I to IV relate to compositions that are all capable of being used to produce insulating and/or sheathing and/or packing materials for power cables and/or telecommunications cables.
These compositions consist of a polymer matrix in which a cork-based fire retardant filler is dispersed. The polymer is common to each of them, and only the nature and quantity of the fire retardant filler varies from one sample to another.
In this respect, it may be observed that one of the compositions constitutes an extreme case and to this end, it should be considered as a reference. In fact, it is constituted solely by polymer. In other words, the quantity of fire retardant filler therein is zero.
Finally, it should be noted that the quantities mentioned in the various tables shown below are conventionally expressed as parts by weight per 100 parts by weight of polymer.
Preparation of Compositions
At all events, the various compositions studied in Examples I to IV were all prepared using the same operating protocol.
The steps of mixing the polymer matrix with each fire retardant filler were thus as follows:
temperature fixed at 160° C. throughout mixing; introduction of synthetic polymer into the internal mixer adjusted to 30 revolutions per minute (rpm); fusion of the synthetic polymer at 160° C. for 2 minutes at 30 rpm; fusion at 60 rpm for 2 minutes; introduction of fire retardant filler at 30 rpm; mixing at 30 rpm for about 10 minutes.
Example I
Example I is intended to evaluate the fire performance of a fire retardant filler based on a first type of cork.
The polymer matrix used was a copolymer of ethylene and vinyl acetate (EVA) containing 28% of vinyl acetate, a product sold under the trade name Evatane 28-03 by Atofina.
The fire retardant filler was an Amorim® MFI powdered cork of Portuguese origin, having a grain size of d50<100 μm and d90<300 μm.
Four material samples 2 to 5 were prepared using the operating protocol described above, employing increasing quantities of fire retardant filler. Sample 1 constituted the reference composition. Table 1 details the differences in compositions between Samples 1 to 5.
TABLE 1
Samples
1
2
3
4
5
EVA
100
100
100
100
100
Cork 1
0
10
20
30
50
Total
100
110
120
130
150
Cone calorimeter analyses were carried out to evaluate and compare the fire performance of Samples 1 to 5.
To this end, the corresponding materials were first formed into square plates with sides of 10 centimeters (cm) and depth of 3 millimeters (mm). This operation was carried out using a heated hydraulic press employing the following procedure:
fusing at 150° C. for 3 minutes; pressurizing to 150 bars for 2 minutes, keeping at 150° C.; cooling with water at 150 bars for 5 minutes.
Samples 1 to 5 were then tested using a cone calorimeter in accordance with International Standard ISO 5660-1 pertaining to the heat release rates of building materials.
The heat release rate during combustion of each sample was measured. FIG. 1 illustrates the respective performance of the various materials.
Table 2 summarizes the principal characteristics of Samples 1 to 5 in terms of fire performance, namely the average heat release rate and the peak heat release rate in kilowatts per square meter (kW/m 2 )
TABLE 2
Sample
1
2
3
4
5
Amount of cork
0
10
20
30
50
Cork content
0%
9%
17%
23%
33%
Average heat
321.15
298.51
223.90
133.92
104.78
release rate
(kW/m 2 )
Reduction in
0%
7%
30%
58%
67%
average heat
release rate
compared with
Sample 1
Peak heat release
1447.07
830.87
585.18
570.82
472.50
rate (kW/m 2 )
Reduction in peak
0%
43%
60%
61%
67%
heat release rate
compared with
Sample 1
The average heat release rate and the peak heat release rate allow the energy released by a material during combustion to be determined. The lower the heat release rate, the less combustible the material.
Sample 1 has the properties of the polymer matrix and as such constitutes a reference.
With Sample 2, it can be seen that adding only 10 parts by weight of cork to the same polymer results in a reduction of 43% in the peak heat release rate compared with Sample 1. The active effect of cork is thus demonstrated. The filler does not just act as a diluent, which would lower the peak heat release by about 9%, but also acts as a fire retardant filler since the reduction is 43%.
Samples 3 to 5 show that an increase in the amount of cork in the composite material generates a large reduction in the peak heat release rate and in the average heat release rate. Thus, adding 50 parts by weight of cork to the polymer causes a reduction of 67% in the peak amount and the average heat release rate, which produces a material with very good reaction to fire even with such a low filler content.
Example II
Example II is intended to determine the fire performance of a fire retardant filler based on a second type of cork.
The polymer matrix used in this second example was again a copolymer of ethylene and vinyl acetate (EVA) containing 28% of vinyl acetate, a product sold under the trade name Evatane 28-03 by Atofina.
However, in this case the fire retardant filler was constituted by Amorim® MF7 powdered cork from Portugal, with a grain size of d50=300 μm and d90<600 μm.
Four material samples 6 to 9 were prepared, again using the operating protocol described above, using increasing quantities of fire retardant filler. Sample 1 was again employed as the reference. Table 3 details the differences in compositions between Samples 1 and 6 to 9.
TABLE 3
Samples
1
6
7
8
9
EVA
100
100
100
100
100
Cork 2
0
10
20
30
50
Total
100
110
120
130
150
In order to determine and compare the fire performance of Samples 6 to 9, cone calorimeter analyses were carried out in a manner entirely similar to that described for Example I.
Thus, the corresponding materials were formed into plates, faithfully following the steps of the shaping procedure described above.
Samples 6 to 9 were then tested using a cone calorimeter in accordance with International Standard ISO 5660-1 pertaining to heat release rates in building materials. Here again, the heat release rate during combustion of each sample was measured. FIG. 2 illustrates the respective performance of the various materials.
Table 4 summarizes the principal characteristics of Samples 1 and 6 to 9 as regards fire performance, namely the average heat release rate and the peak heat release rate.
TABLE 4
Sample
1
6
7
8
9
Amount of cork
0
10
20
30
50
Cork content
0%
9%
17%
23%
33%
Average heat
321.15
247.91
125.43
121.06
111.82
release rate
(kW/m 2 )
Reduction in
0%
23%
61%
62%
65%
average heat
release rate
compared with
Sample 1
Peak heat release
1447.07
650.84
483.61
431.13
372.50
rate (kW/m 2 )
Reduction in peak
0%
55%
67%
70%
74%
heat release rate
compared with
Sample 1
With Sample 6, it can be seen that adding only 10 parts by weight of cork to the polymer matrix results in a reduction of 55% in the peak heat release rate by Sample 1. As in Example I, the active effect of cork is thus demonstrated. Here again, the filler does not just act as a diluent, which would lower the peak heat release rate by about 9%, but also as a fire retardant filler since the reduction is 55%.
However, it should be noted that the active effect of the cork is not strongly dependent on the type of cork used. Example II shows that the MF7 cork performed better than the MF1 cork of Example I, but the fire retardant effect remains of the same order of magnitude (43% as opposed to 55% at 10 parts by weight).
Samples 7 to 9 show that an increase in the amount of cork in the composite material generates a large reduction in the peak heat release rate and in the average heat release rate. Thus, adding 50 parts by weight of MF7 cork to the polymer can reduce the peak and average heat release rate by 74% and 65% respectively, which means that a material can be produced with a reaction to fire that is very good for its low filler content.
Example III
Finally, Example III evaluates the fire performance of a fire retardant filler based on a third type of cork.
The polymer matrix used was again a copolymer of ethylene and vinyl acetate (EVA) containing 28% of vinyl acetate, a product sold under the trade name Evatane 28-03 by Atofina.
However, this time the fire retardant filler was composed of powdered cork from France of the Liegeur® trademark, with a grain size of d50<100 μm and d90<300 μm.
Four material samples 10 to 13 were prepared, again using the operating protocol of Examples I to IV, using increasing quantities of fire retardant filler. Table 5 details the differences in compositions between Samples 1 and 10 to 13.
TABLE 5
Samples
1
10
11
12
13
EVA
100
100
100
100
100
Cork 3
0
10
20
30
50
Total
100
110
120
130
150
Once again, the corresponding materials were firstly formed into plates before carrying out cone calorimeter analyses in order to evaluate and compare the fire performance of Samples 10 to 13. The procedure followed was once again International Standard ISO 5660-1 pertaining to heat release rates in building materials.
The heat release rate during combustion of each sample was measured. FIG. 3 illustrates the respective performance of the various materials.
Table 6 summarizes the principal characteristics of Samples 1 and 10 to 13 as regards fire performance, namely the average heat release rate and the peak heat release rate.
TABLE 6
Sample
1
10
11
12
13
Amount of cork
0
10
20
30
50
% of cork
0%
9%
17%
23%
33%
Average heat
321.15
172.21
150.61
109.39
83.40
release rate
(kW/m 2 )
Reduction in
0%
46%
53%
66%
74%
average heat
release rate
compared with
Sample 1
Peak heat release
1447.07
671.82
505.71
432.01
377.24
rate (kW/m 2 )
Reduction in peak
0%
54%
65%
70%
74%
heat release rate
compared with
Sample 1
This Example III demonstrates a fire retardant effect that is comparable to those described in the preceding examples. The cork used was again of a different nature, but the fire retardant effect remained of the same order.
However, it should be noted that this novel type of cork can further reduce the average heat release rate compared with Examples I and II.
The reduction in the peak heat release rate in Samples 10 to 13 is identical to that obtained for Example II with Samples 6 to 9.
The reduction in the average and peak heat release rate observed between Samples 10 to 13 shows that a material can be obtained having a reaction to fire that is exceptional, with a 74% reduction in the heat release rate, with only 50 parts by weight of cork per 100 parts by weight of polymer.
Example IV
Example IV compares the fire performance of the fire retardant fillers of the invention with those of conventional prior art fillers.
Samples 6, 8 and 9, which represent materials deriving from compositions filled with cork, were entirely in accordance with those prepared and tested in the context of Example II.
Samples A, B and C, which were used here as references, employed fire retardant fillers constituted by aluminum trihydroxide, usually known by its abbreviation ATH. The product used was Martinal OL-104 from Martinswerk GmbH. Their polymer matrices were all constituted by a copolymer of ethylene and vinyl acetate (EVA) containing 28% vinyl acetate, in this case Evatane 28-03 again from Atofina.
The three material samples A, B and C were again prepared using the operating protocol used in Examples I to IV, and using increasing quantities of fire retardant filler. Table 7 details the features of each of the compositions employed.
TABLE 7
Samples
EVA (%)
ATH (%)
Cork (%)
1
100
0
0
A
91
9
0
6
91
0
9
B
77
23
0
8
77
0
23
C
67
33
0
9
67
0
33
The samples were then tested using a cone calorimeter to determine and then compare their respective fire performances. Their prior shaping was again carried out using the procedure defined in ISO 5660-1 pertaining to heat release rates in building materials.
The heat release rate was thus measured during combustion of each sample. Table 8 summarizes the principal characteristics of the various samples in terms of fire performance, namely the average heat release rate and the peak heat release rate.
TABLE 8
Reduction in
peak heat
Average heat
Peak heat
release rate
release rate
release rate
compared with
Sample
(kW/m 2 )
(kW/m 2 )
Sample 1
1
321.15
1447.07
0
A
242.02
1273.76
12%
6
247.91
650.84
55%
B
278.22
939.51
35%
8
121.06
431.13
70%
C
166.95
610.86
58%
9
111.82
372.50
74%
It can be seen that Samples 6, 8 and 9 performed better than Samples A, B and C respectively. In fact, while the reduction in the peak heat release rate was of the order of 12% for a composite containing 10 parts by weight of aluminum hydroxide, it reached 55% for a composite containing the same quantity of cork.
The fire retardant active effect of aluminum hydroxide, known in the prior art, was confirmed with Samples A, B and C since the reduction in the heat release rate was greater than reduction due solely to dilution of the combustible polymer. However, the fire retardant effect of cork in this same polymer appeared to be substantially greater: at 10 parts by weight (samples A and 6), the cork was more than 4.5 times more active than aluminum hydroxide; at 30 parts (Samples 8 and B), the cork was 2 times more active than aluminum hydroxide; and at 50 parts, the cork could further improve the reaction to fire by about 30% compared with aluminum hydroxide.
This example thus confirms that cork plays an exceptional active fire retardant role compared with prior art systems.
|
The present invention concerns a fire resistant composition particularly for a power and/or telecommunications cable, said composition comprising a polymer and a fire retardant filler. The invention is remarkable in that the polymer is thermoplastic in type and in that the fire retardant filler comprises cork.
| 2
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INCORPORATION BY REFERENCE
The disclosure of Japanese Patent Application No. 2003-024432 filed on Jan. 31, 2003 including the specification, drawings and abstract is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a seat belt warning apparatus that generates an alert sound to alert, or remind, a vehicle occupant that his or her seat belt is unbuckled. More specifically, it relates to the same apparatus configured to generate the alert sound in a different way depending upon each warning level, and a method corresponding to the operation of such an apparatus.
2. Description of the Related Art
One known system (see U.S. Pat. No. 6,278,358) triggers an alert sound in two steps to remind an occupant that his or her seat belt is unbuckled depending upon the vehicle speed. Typically, a waning system of this kind starts up when the ignition is turned on, and determines the seat belt to be in the buckled condition in response to a corresponding seat belt buckle switch turning on. With such a system, therefore, the alert sound sounds from the ignition turning on until the seat belt buckle switch turning on.
The above audible alert triggered upon starting up the vehicle is generally called “a primary audible alert”, and one related US regulation prohibits that such an alert lasts longer than 8 seconds. The system disclosed in the above publication is arranged to cope with this requirement, which monitors, after provision of the primary audible alert, the vehicle speed and triggers a secondly audible alert in response to the vehicle starting running.
With this system, however, if a different alert sound is used for each audible alert (i.e., primary audible alert, secondary audible alert), the occupant may not realize that the secondary audible alert is alerting him or her that his or her seat belt is unbuckled due to other audible indications indicating the headlight still remaining “ON”, etc. This situation is more likely when the primary audible alert is deactivated within 8 seconds as required in the above-stated US regulation, because there is a time period of no alert (i.e., alert sound) from the end of the primary audible alert to the beginning of the secondary audible alert.
It is true that the occupant can easily associate both the primary and secondary audible alerts with the unbuckled seat belt if the same alert sound is generated in the same way for each alert. This would however make it impossible to provide a classified alert system capable of producing a higher warning level alert when the vehicle is running than when the vehicle is stationary. Also, it should be appreciated that, if the same alert sound is generated in the same way during the primary audible alert as the secondary audible alert that is a relatively strong warning, that excessively strong primary audible alert may annoy the occupant because it is activated almost every time he or she starts the vehicle.
Thus, it is difficult to achieve such a classified seat belt alert system which assures the occupant's correct recognition of each audible alert.
SUMMARY OF THE INVENTION
To solve the above-mentioned problems, the present invention has been made to provide a seat belt warning apparatus for a vehicle occupant, which provides an audible alert corresponding to each different warning level.
To achieve this object, a first aspect of the invention relates to a seat belt warning apparatus for a vehicle occupant including a seat belt, an audible indicator for generating an alert sound having prescribed frequencies and volume, and a controller for providing via the audible indicator, either one of a first audible alert corresponding to a first warning level and a second audible alert corresponding to a second warning level that is higher than the first warning level when the seat belt is unbuckled. The controller is adapted to sound a first alert chime by repeating the alert sound at a first cycle during the first audible alert, and a second alert chime by repeating the same alert sound at a second cycle that is different from the first cycle, during the second audible alert.
According to this apparatus, the same alert sound (frequency, volume) is used during each audible alert. Thus, the occupant can easily realize that the alert is alerting him or her of the unbuckled seat belt. Moreover, a plurality of audible alerts can be provided by only repeating the alert sound at different cycles in accordance with the warning level.
It should be noted that the cycle of repeating the alert sound is changed by changing the length of generating each alert sound, as well as by changing the time interval at which the alert sound is repeated.
A second aspect of the invention relates to a seat belt warning apparatus for a vehicle occupant including a seat belt, an audible indicator for generating an alert sound, a controller for a controller for providing either one of a first audible alert corresponding to a first warning level and a second audible alert corresponding to a second warning level that is higher than the first warning level when the seat belt is unbuckled. This controller is adapted to sound via the audible indicator an alert chime corresponding to the first warning level before an alert chime corresponding to the second warning level during the second audible alert.
According to the second aspect of the invention, in a case where the secondary audible alert should be activated after the primary audible alert was stopped so as to comply with the above-stated US regulation, sounding the alert chime corresponding to the first warning level (i.e., lower warning level), with which the occupant is relatively familiar, prior to the alert chime corresponding to the second warning level (i.e., higher warning level) makes it easier for the vehicle occupant to realize that the alert is alerting him or her of the unbuckled seat belt.
A third aspect of the invention relates to a method of providing a vehicle occupant with a first audible alert corresponding to a first warning level or a second audible alert corresponding to a second warning level that is higher than the first warning level, to alert the vehicle occupant that his or her seat belt is unbuckled. This method includes the steps of: sounding a first alert chime by repeating an alert sound having prescribed frequency and volume at a first cycle during the first audible alert; and sounding a second alert chime by repeating the same alert sound at a second cycle during the second audible alert.
A fourth aspect of the invention relates to a method of providing a vehicle occupant with a first audible alert corresponding to a first warning level or a second audible alert corresponding to a second warning level that is higher than the first warning level, to alert the vehicle occupant that his or her seat belt is unbuckled. In this method, during the second audible alert, an alert chime corresponding to the first warning level is sounded before an alert chime corresponding to the second warning level.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and/or further objects, features and advantages of the invention will become more apparent from the following description of preferred embodiments with reference to the accompanying drawings, in which like numerals are used to represent like elements and wherein:
FIG. 1 is a block diagram showing the configuration of a seat belt warning apparatus according to one exemplary embodiment of the present invention;
FIG. 2A is a view illustrating a pattern of generating an audible sound to produce a first alert chime;
FIG. 2B is a view illustrating a pattern of generating an audible sound to produce a second alert chime; and
FIG. 3 is a timing chart illustrating one exemplary case for explaining the operation of the seat belt warning system of the embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a seat belt waning apparatus according to one exemplary embodiment of the invention will be described with reference to the accompanying drawings. To comply with the US regulation previously stated, this apparatus is configured to deactivate the primary audible alert within 8 seconds.
FIG. 1 is a block diagram schematically showing the configuration of a seat belt warning apparatus 100 of the exemplary embodiment. Referring to this drawing, the seat belt warning apparatus 100 includes a buzzer 102 for generating an alert sound, an ECU (Electric Control Unit) 101 that activates an audible alert in response to detecting the seat belt being unbuckled, and an warning light 103 that is on or blinks while the seat belt remains unbuckled. The warning light 103 may individually be provided for each of the driver seat and the navigator seat.
The seat belt apparatus further includes an ignition 104 , a driver seat belt buckle switch 105 , and a navigator seat belt buckle switch 106 . The ECU 101 detects the state of the ignition 104 being at the ON or OFF position, the driver seat belt buckle switch 105 being ON or OFF, and the navigator seat belt buckle switch 106 being ON or OFF. Also, the ECU 101 detects the vehicle speed via a vehicle speed sensor 107 . The driver seat belt buckle switch 105 is ON when the driver seat belt is buckled, and OFF when unbuckled, and the navigator seat belt buckle switch 106 is ON when the navigator seat belt is buckled, and OFF when unbuckled.
FIG. 2A is a view schematically illustrating generation pattern of an alert sound via the buzzer 102 to sound a “first alert chime”, while FIG. 2B is a view schematically illustrating a generation pattern of the same chime to sound a “second alert chime”. Unless otherwise specified, the first alert chime corresponds to the primary audible alert, whereas the second alert chime corresponds to the secondary audible alert.
The alert sound generated for sounding each alert chime has common frequencies (e.g., 800 Hz and 1.9 kHz), duty ratio (e.g., D 1 =D 2 =50%), and sound volume (e.g., 63 dB). Namely, the buzzer 102 generates substantially the same sound for each alert chime.
In each chime, however, the alert sound is repeated at a different cycle to indicate a specific warning level so that the occupant can distinguish each alert (warning level) by that repetition cycle of the alert sound. In this exemplary embodiment, the first alert chime adopts a repetition cycle f 1 of 1.2 second, and the second alert chime adopts a repetition cycle f 2 of 0.4 second.
Hereinafter, conditions of activating and deactivating each alert will be described. First, the activating conditions will be described. The ECU 101 activates a primary audible alert in response to the driver seat belt buckle switch 105 being OFF upon turning on the ignition 104 to the ON position. Because this is a primary audible alert, for example, the first alert chime continues for 6 seconds (1.2 sec*5).
Then, if at least one of the driver seat belt and the navigator seat belt still remains unbuckled and the vehicle is running at 15 km/h or more after the primary audible alert ends, the ECU 101 then activates the secondary audible alert.
According to the exemplary embodiment, the secondary audible alert first sounds the first alert chime for 30 seconds, and the second alert chime for 90 seconds. In other words, the same sound is repeated for a total of 120 seconds, during which the cycle at which the alert sound is repeated is shortened. Such repetition of the alert sound makes it easier for the occupant to realize the chime is alerting him or her of the unbuckled seat belt, and then notice by the shortened repetition cycle that the present warning level for that unbuckled seat belt is higher than the warning level of the primary audible alert triggered upon turning on the ignition 104 .
Also, if the secondary audible alert is timed out with one of the buckle switches being ON and the same switch then turns off, the ECU 101 activates the secondary audible alert again from the first alert chime.
The ECU 101 ignores satisfaction of the above-stated conditions of activating the primary and secondary audible alerts when the buzzer 102 is sounding each alert chime. That is, under no circumstance, the first alert chime interrupts the second alert chime.
Next, the deactivating conditions will be described. The ECU 101 deactivates the primary audible alert in response to the ignition 104 being turned to the OFF position, the driver seat belt buckle switch 105 being turned on, or the elapse of the activation time of the primary audible alert (i.e., 6 seconds). Similarly, the ECU 101 deactivates the secondary audible alert in response to the ignition 104 being turned to the OFF position, the driver seat belt buckle switch 105 and the navigator seat belt buckle switch 106 being both turned on, or the elapse of the activation time of the secondary audible alert (90 seconds from the shift to the second alert chime).
Once the condition of activating the alert is satisfied, the vehicle speed will no more be used as a parameter. That is, once the secondary audible alert has been activated, the ECU 101 will not turn off the buzzer 102 even if the vehicle stops during activation of the alert. Also, even if the vehicle accelerates up to 15 km/h or more after the secondary audible alert has been timed out, the ECU 101 will not turn on the buzzer 102 again.
FIG. 3 is a timing chart illustrating one exemplary case for explaining the operation of the seat belt warning apparatus 100 . Referring to the chart, the ignition 104 is turned to the ON position at time t 1 . Since the driver seat belt buckle switch 105 and the navigator seat belt buckle switch 106 are both OFF at this time, namely the driver seat belt and the navigator seat belt both remain unbuckled, the ECU 101 activates the primary audible alert by sounding the first alert chime via the buzzer 102 . To comply with the above-stated US regulation, this audible alert continues for 6 seconds and ends at time t 2 .
Then, the vehicle starts running although the seat belts both remain unbuckled, When the vehicle speed reaches 15 Km/h at time t 3 , the ECU 101 then triggers the secondary audible alert starting with the first alert chime.
The vehicle stops at time t 4 . However, since the buzzer 102 is still sounding the first alert chime at this time, the ECU 101 ignores this change in the vehicle speed associated with the stop of the vehicle and continues the first alert chime.
At time t 5 , 30 seconds of the first alert chime ends, and the second alert chime starts. Although the navigator seat belt is buckled at time t 5 , the ECU 101 does not deactivate the secondary audible alert because the driver seat belt still remains unbuckled.
Subsequently, the driver seat belt is unbuckled and the vehicle speed reaches 15 Km/h at time t 6 . However, this does not satisfy any deactivating condition, so that the ECU 101 continues the second alert chime.
Then, the vehicle again stops and the driver seat belt is buckled at time t 7 . At this stage, the ECU 101 turns off the warning light 103 in response to the driver seat belt being buckled, however continues the second alert chime due to the navigator seat belt still unbuckled.
Then, the driver seat belt is unbuckled and the warning light 103 turns on at time t 8 . Here, as aforementioned, the ECU 101 ignores satisfaction of any activating condition because the buzzer 102 is sounding the alert chime, and therefore the ECU 101 does not restart the secondary audible alert from the first alert chime in response to the driver seat belt being buckled, but continues the second alert chime.
At time t 9 , 90 seconds of the second alert chime ends, namely the secondary audible alert is timed out although both the driver and navigator seat belts remain unbuckled.
The vehicle speed again reaches 15 Km/h at time t 10 . However, because the secondary audible alert has been triggered before, the ECU 101 ignores this change in parameter (i.e., vehicle speed).
When the vehicle stops and the ignition 104 is turned to the OFF position at time t 11 , the ECU 101 turns off the buzzer 102 .
The ignition 104 is again turned to the ON position at time t 12 . Because both the driver and navigator seat belts remain unbuckled at this time, the ECU 101 turns on the warning light 103 and activates the primary audible alert sounding the first alert chime via the buzzer 102 .
At time t 13 , the alert mode immediately shifts from the primary audible alert to the secondary audible alert in response to the vehicle speed reaching 15 Km/h. In the initial stage of the secondary audible alert, as aforementioned, the ECU 101 first sounds the first alert chime for 30 seconds, and starts the second alert chime at time t 14 .
Subsequently, the driver and navigator seat belts are both buckled at time t 15 while the vehicle is still running. Because this satisfies the condition of deactivating the secondary audible alert, the ECU 101 immediately turns off the buzzer 102 sounding the second alert chime.
Then, the navigator seat belt is unbuckled at time t 16 , and therefore the secondary audible alert is again activated from the first alert chime.
This chime lasts 30 seconds and the cycle at which the alert sound is repeated is changed at time t 17 (i.e., the beginning of the second alert chime). At time t 18 , which is 90 seconds after time t 17 , the secondary audible alert is timed out due to the navigator seat belt still unbuckled.
At time t 19 , the ECU 101 re-triggers the secondary audible alert from the first alert chime in response to the driver seat belt being unbuckled, since the last secondary audible alert was timed out with the driver seat belt buckled.
Although the navigator seat belt is buckled at time t 20 , the first alert chimes continue since the driver seat belt still remains unbuckled. The second alert chime starts at time t 21 which is 30 seconds after time t 19 , and the secondary audible alert is timed out at time 22 which is 90 seconds after time t 21 .
Thus, the secondary audible alert is timed out with the navigator seat belt buckled. Therefore, the ECU 101 activates the secondary audible alert again from the first alert chime at time t 23 in response to the navigator seat belt being unbuckled.
According to the exemplary embodiment, as described above, the ECU 101 sounds the same chime via the buzzer 102 in the initial stage of the secondary audible alert as during the primary audible alert that the occupant usually hears when starting the vehicle. Therefore, the occupant can readily realize that his or her seatbelt is unbuckled at the beginning of the secondary audible alert.
Also, during the secondary audible alert, the cycle at which the alert sound (i.e., sound of the same frequencies and volume) is repeated is shortened. This makes the occupant notice that the present warning level for the unbuckled seat belt becomes higher than the primary audible alert, while assuring the correct recognition of the occupant as to the unbuckled seat belt warning.
While the invention has been described with reference to the exemplary embodiments thereof, it is to be understood that the invention is not limited to the preferred embodiment or construction. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the preferred embodiments are shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the invention.
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The alert sound having specific frequencies and volume is repeated at a different cycle depending upon each warning level. Additionally, or alternatively, the audible alert corresponding to the lowest warning level is activated before activating the audible alert corresponding the present warring level.
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[0001] This is a continuation-in-part of U.S. Pat. No. 7,922,976 filed on Oct. 23, 2006, and also application Ser. No. 13/041,433 filed on Mar. 6, 2011, which is a divisional of application(s) Ser. No. 11/552,080 filed on Oct. 23, 2006
FIELD OF THE INVENTION
[0002] The present invention relates to high sensitivity sensor devices and its signal processing circuits to detect the gas, biomolecules, cells, or biochemical agents (altogether herein after mentioned as bio-agents). More specifically, this invention is related to sensor device comprising with at least one nano-chip for application in biomedical and industrial applications. Furthermore, the continuation in part is more particularly related to the system and method to diagnosis of virus, bacteria, cells, or infectious diseases, mainly found in body-fluidic system (e.g. fluid, blood) in human.
BACKGROUND OF THE INVENTION
[0003] The contents of all references, including articles, published patent applications and patents, if referred to anywhere in this specification are hereby incorporated by reference.
[0004] A large benefit of this sensor according to this invention, is that there can be several on a single wafer. It is a device able to measure chemical agent concentrations below part-per-billion (ppb) level and accurately determine the biomolecule agent and volume of biological cells present in human body. There is no device in the state-of-art, which allows concurrent detection of a chemical agent, biomolecule agent, and biological cell, all in a single system.
[0005] There are various kinds of sensor system. FIG. 1 shows a schematic representing the prior art of a sensor system 1 to detect biological cells, biomolecule agents or chemical agents (hereafter mentioned as specimen). The system 1 usually comprising with the sensor cell 2 , power supply 4 , detector 6 , and analyzer 8 . The system 1 usually detects or senses by detecting the electrical signal 10 induced due to absorption of the specimen. Detector 6 will detect the output signal 10 and send to the analyzer 8 to analyze the concentration of the specimen.
[0006] Several techniques can be found as the prior art for detecting concentration of specimen (common term used hereafter separately for chemical, biomolecule agents, or biological cells). However, most of them are based on the standard electrical technique wherein only single specimen is considered to detect. In addition, most technique requires long time in detection and/or not highly sensitive. The following, as a point of reference, are some methods, which are already patented and described as biosensors, used for detection of biological cells.
[0007] Peeters, in U.S. Pat. No. 6,325,904, (issued on Dec. 4, 2001), discloses a nanosensor, using an array of electrodes at the atomic or nano scale (nanoelectrodes) level, formed by using specific receptors. Utilizing the level of current flow while specific biological cells attached determine the concentration. The drawbacks of such technique are: (i) requiring STM to position the receptor which time consuming fabricating such sensor, (ii) requiring specific nano-scale level gap in between electrodes containing receptor to conduct current, (iii) difficulties in measuring low current level (corresponding to low concentration) due to use of computer controlled technique, and (iv) requiring high power due to using of computer controlled signal processing.
[0008] Bornhop, et al., in U.S. Pat. No. 6,809,828, (issued Oct. 26, 2004), discloses an sensor system for detecting proteins or DNA. Concentration is estimated based on the fringe pattern, detected by the CCD camera in addition with laser beam analyzer. Fringe pattern is usually depending on the laser intensity and position of the CCD camera. The drawback of this technique are, (i) in accuracy in concentration measurement as fringe pattern is dependent on the laser intensity and position, (ii) difficulties in low level concentration measurement due to difficulties in finding small changes in fringe pattern, and (iii) complete system becoming bulky as CCD camera, position sensor, and laser beam analyzer are to be used.
[0009] Britton, Jr., et al., in U.S. Pat. No. 6,167,748, (issued Jan. 2, 2001), discloses a technique for detecting the glucose concentration in blood. Measurement of concentration is performed based on standard technique of measuring the changes in capacitance. Technique uses cantilever coated with the receptor for absorbing the glucose. Main drawbacks are: (i) inability to detect low level concentration as very low changes in the capacitive is difficult to measure, and (ii) difficulties of detection of different kind of biological cell at the same time as each cantilever require different coating. Similar detection techniques can also be found in other patents such as U.S. Pat. No. 6,856,125, of Kermani (issued Feb. 15, 2005), U.S. Pat. No. 5,798,031 Charlton et al., (issued Aug. 25, 1998), U.S. Pat. No. 5,264,103 of Yoshioka et. al., (issued Nov. 23, 1993), and U.S. Pat. No. 5,120,420 of Nankai et. al., (issued Jun. 9, 1992), in all of which capacitive techniques are used to detect the concentration. Chemical and biological sensors can be miniaturized using nanowires or carbon nanotubes. Continued advances in nanoscience and nanotechnology require tiny sensors and devices to analyze small sample sizes. The following is a discussion of the prior art in sensor fabrication.
[0010] After discussing the above issues pertaining to the state-of-art biosensors, chemical sensors, and biomolecule sensors, and methods of making them, we would now like to introduce a novel technique where multiple chemical agents can concurrently be detected in real time and the information can quickly be transmitted to a main station and displayed. It is small in size, so the end user may carry it anywhere to measure the biological cell volume, protein, and biomolecule cells in a medical science application and is also able to do concurrent real time detection of different kinds of chemical agents.
[0011] Despite the advances in therapeutics and improved public health measures, infectious diseases still remain the major cause of morbidity and mortality in most parts of the world. Clinical syndromes are rarely specific for single pathogens, so multiplexed diagnostics provide good detection sensitivity, but are often slow, bulky, expensive, and reliant on trained medical personnel. The development of handheld diagnostic systems that can provide rapid diagnosis for multiplexed detection of pathogens could significantly contribute to the prevention and treatment of infectious diseases.
[0012] Similarly, that same multiplexed detection technology can be utilized to diagnose a single condition, such as HIV. Studies have shown that people newly infected with HIV are most contagious because of the initial high viral loads. However, early stage detection is currently expensive and inaccurate. These detection systems have proven to be of limited benefit. Many potentially infected people cannot afford the laboratory testing necessary, or cannot justify the cost due to the chances of a misdiagnosis. The multiplexed sensor described herein, however, will be relatively inexpensive, can be used by the average consumer, and will give results quickly and accurately. There is thus a corresponding need to develop a universal diagnosis device, which can diagnosis multiple bio-agents (including infectious diseases, cells, DNA, RNA etc.), improve the effectiveness, sensitivity, and accuracy of diagnosis by reducing time and complexity, and by improving accuracy and consistency of assessment of diagnosis studies. There is a clear role and need for a system and methods, to improve sensitivity, accuracy, and diagnosis time and facilitate more accurate and consistent diagnosis.
SUMMARY OF THE INVENTION
[0013] According to this current invention, it is an object to provide a sensor system comprising with a sensor more specifically relates to a novel nano-sensor. It is also object to provide the embodiments including novel methods, systems, devices, and apparatus for sensing one or more characteristics. One aspect of the present invention is a sensor, which is capable of distinguishing between different molecular structures in chemical agents at the same time. It is also capable of distinguishing between different types of biomolecule agents or biological cell concentrations. It is capable of detecting the concentration of different types of chemical agents, biomolecule agents, and biological cells.
[0014] This present sensor system is based on any type waveguide, including but not limited to: the slab waveguide, the ridge waveguide, or a dielectric materials structure based waveguide. Its bottom clad (hereafter mentioned as substrate) can be formed using an array of various dielectric materials, structured periodically, which can form the photonic-band-gap (PBG). In waveguide, the guided light usually suffers radiation loss due to weak optical confinement; this happens when the structure is not well optimized or the structural parameters are interrupted. The sensor structure is optimized for a fixed wavelength and is designed in such a way that the propagation loss is minimal. Alternatively, according to this invention, the sensor can also be designed to operate in broadband light operation. In that case, the waveguide for nano-chip can be designed to operate multi-mode of operation.
[0015] This sensor detects the concentration of gases (that exist in air) based on the change in the effective refractive index of the substrate caused when biomolecule gas/chemical agents fill the air (or receptor) spaces. The changes in the effective refractive index reduce the output optical power (measurable parameter). By comparing the output optical power with the reference input optical power, the proposed nanosensor can detect the biomolecule gas/chemical agent concentration in ppb levels.
[0016] It is noted here that the type of chemical agent/gas can be specified by using a fixed receptor specifically made for absorbing said agent/gas. Also, the type of biomolecule agent or biological cell can be specified by using a fixed receptor to absorb the said biomolecule agent or biological cell. The concentration of the agent/gas and the biomolecule agent, and the volume of biological cells can be ascertained by measuring the output optical power, which is a function of the change in effective refractive index and density. In this case, the detector will detect the presence of a chemical agent/gas or a biomolecule agent or a biological cell. Then it will generate an electrical signal, which will be processed through a processing circuit. After the processing circuit, a digital monitoring system will display the actual concentration present via LED.
[0017] The materials used for the nanosensor and surrounding surfaces are selected based on their electrical and chemical properties. The PBG arrays may be included in a chamber, which can retain fluid for biological applications; another set of arrays can be used for chemical agents/gas detection. Several arrays may be used in a single chamber and several different chambers may be used in a single chip. Thus, one system may detect chemical agents/gas, biomolecule agents, and biological cells.
[0018] This proposed PBG based nanosensor array and chamber as attached should be separated from each other on a chip, so that each system works properly for each individual application. A Digital Signal Processing (DSP) function, Analog to Digital Converter (ADC), and microprocessor are provided to analyze signals from the nanosensors and/or do real time calculations of the accurate values obtained from the nanosensor.
[0019] In some other embodiments a communication setup is used in order to relay the output values long distances. This communication setup is included to analyze the real time sensing values remotely.
[0020] Further embodiments, forms, features, objects and advantages of the present invention will be apparent from the following description.
[0021] Further, two specific embodiments for medical application are included. First, described is an embodiment for detecting pathogens, such as Hepatitis B (HBV), through testing of blood, saliva, or other body tissue. Second, described is an embodiment for detecting HIV in the blood.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The features and advantages of the present invention will become apparent and may be better understood from the following detailed description of the system, taken in conjunction with the accompanying drawings, wherein
[0023] FIG. 1 is a schematic of sensor system in prior art.
[0024] FIG. 2 are the block diagrams representing the schematic of the sensor system for detecting the gas, bio-molecule, or biological cell concentration.
[0025] FIG. 3A is a enlarged view of a nano-chip comprising with a waveguide based on photonic bandgap (or photonic crystal) structures having rectangular lattice, according to this invention, and FIG. 3B is a cross-section view across AA′ as shown in FIG. 3A .
[0026] FIG. 4 is a schematic diagram of a nano-chip comprising with a waveguide based on photonic bandgap (or photonic crystal) structures having triangular lattice according to this invention, and FIG. 4B is a cross-section view across BB′ as shown in FIG. 4A .
[0027] FIG. 5 is a schematic diagram of a nano-chip comprising with a waveguide based on photonic bandgap (or photonic crystal) structures having rectangular lattice, according to this invention, and FIG. 5B is a cross-section view across CC′ as shown in FIG. 5A , where the PBG is rectangular in shape with holes and a slab waveguide is used.
[0028] FIG. 6 is a schematic diagram of a nano-chip comprising with a waveguide based on photonic bandgap (or photonic crystal) structures having defects and rectangular lattice, according to this invention, and FIG. 6B is a cross-section view across DD′ as shown in FIG. 6A .
[0029] FIG. 7 is a schematic diagram of a nano-chip comprising with a waveguide based on photonic bandgap (or photonic crystal) structures having defects, according to this invention.
[0030] FIG. 8 is schematic of interconnection between the nano-chip and its detector.
[0031] FIG. 9 is the block diagram representing an example of an electrical signal processing circuit to detect the specimen, according to this invention.
[0032] FIG. 10A is a schematic representing a integration circuit unit for signal pre-processing, a part of processing circuit, as shown in FIG. 9 , according to this invention, and FIGS. 10B and 10C are output signals at points A and B, shown in FIG. 10A .
[0033] FIG. 11A is a schematic representing a filter circuit unit, a part of signal post processing, according to this invention, and FIGS. 11B and 11C are output signals showing with capture points, with and without specimen absorption.
[0034] FIG. 12 is a schematic representing a read-out circuit used to store the reference signal.
[0035] FIG. 13 is a block diagrams representing monitoring unit according to this invention.
[0036] FIG. 14 is a schematic representing an alternative read-out circuit to store the reference signal.
[0037] FIG. 15 is a schematic showing an example of a complete sensor device for multiple specimens' detection, according to this invention.
[0038] FIG. 16 is a schematic showing an example of a complete sensor device, packaged in small form-factor, according to this invention.
[0039] FIG. 17 is a schematic showing the manufacturing process for the nanochip, according to this invention.
[0040] FIG. 18 is a schematic showing an embodiment including a blood filtration system on a disposable test strip, which is connectable to the diagnosis device, according to this invention.
[0041] FIG. 19 is a detailed illustration of a potential embodiment, based on the schematic shown in FIG. 18 , according to this invention
[0042] FIG. 20A is a schematic showing a illustrative diagram of the functionality of HIV-1 RNA TAT aptamers as bioreceptors for HIV-1 TAT protein binding and can be used in this biosensor, for diagnosis of HIV, according to this invention.
[0043] FIG. 20B is a schematic showing a Illustrative diagram of the functionality of HIV-1 antigens as bioreceptors for binding with antibodies for HIV diagnosis
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] Some embodiments of the current invention are discussed in detail below. In describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. A person skilled in the relevant art will recognize that other equivalent components can be employed and other methods developed without departing from the broad concepts of the current invention.
[0045] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the inventions may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention and it is to be understood that other embodiments may be utilized. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
[0046] According to this current invention, it is our objective to provide a sensing device comprising with nano-sensor and its signal processing circuit which can have the significantly high sensitivity. The sensor device detects the specimen concentration based on the principle of optics. Using of the nano-sensor and signal processing circuit, according to this invention, high sensitivity can be achieved. Detection is mainly based on detecting the difference in intensity of optical signal obtained after specimen absorb in the receptor and converting to electrical signal and their arithmetic processing to achieve significant high sensitivity.
[0047] FIG. 2 shows a block diagram of the system according to this invention. In block diagram 22 , input optical signal 14 is generated from a laser 12 having a wavelength ranging from ultra-violet to infrared. The signal 14 will pass through the nano-chip 16 ( a, b, c, d, e ). For a unique and optimized design (with no presence of specimen or sample) intensity of output optical power 18 from the nano-chip 16 ( a, b, c, d, e ) can be same as that of input optical power 14 . This means that the coupling loss though the nano-chip is be zero. The presence of the specimen or sample inside of the nano-chip 16 ( a, b, c, d, e ) will cause a reduction in the output optical power 18 , detected by the detector 20 . The reduction in output optical power 18 , if any, is due to the change in the refractive index of the receptors with and without absorption of the specimen. The receptor is usually contained in the nano-chip 16 ( a, b, c, d, e ), explained later in FIG. 3 . The detector 20 is used to convert the optical signal 18 into an electrical signal 26 and the said electrical signal 26 is processed through the processing circuit 28 , explained later in detail in FIGS. 9-13 . The resultant signals 29 ( a ) and 29 ( b ) from said processing circuit 28 is passed through digital signal processing circuit (DSP) 30 where related arithmetic function can be performed to monitor actual concentration of the specimen in real time. Details of the DSP circuits are provided in FIG. 13 .
[0048] According to this invention, the processing circuit can be made in hybrid using different functional chips or using single chip having all functions, and those can be fabricated from 350 nm or less geometry. The detector can be chosen based on the wavelength of the light to be used in the system 22 . For example, if the wavelength is selected in visible region, the silicon-detector can be used in system 22 . On the other hands, if the wavelength of near infrared is chosen, then the detector made from III-V compound semiconductor is required for having higher sensitivity.
[0049] According to this invention, the system 22 can be miniaturized into a very small package (e.g. less than 1 to 0.5 inches in dimension). The main advantage of the system 22 , according to this invention, is that only the power of output optical signal 18 needs to be known in order to ascertain the concentration. In system 22 , very little power will be absorbed by the nano-chip and this is based on the percentage of the refractive index change. The system 22 has two parts: the first is a ‘detection part’ comprising of laser 12 , nano-chip 16 ( a, b, c, d, e ), and the detector 20 ; the second is an ‘analyzing part’, comprising of signal processing circuits 28 and 30 .
[0050] According to this invention, different nano-chips 16 ( a, b, c, d, e ) are explained in FIGS. 3 to 7 . FIG. 3A shows a schematic, representing the enlarge view of a nano-chip 16 a and FIG. 3B is the cross-sectional view of section AA′, as shown in FIG. 3A . According to this invention, the nano-chip 16 a can be made from photonic crystal comprising of dielectric rods 32 arranged periodically in hollow clad 33 (hereafter we define clad as a substrate with a refractive index ‘n sub ’) to form a photonic-band-gap (PBG) and/or photonics-crystal structures, having rectangular lattice 34 . The nano-chip 16 a has waveguide structure having core 35 having refractive index of ‘n core ’. Each rod 32 has a radius of ‘r’ (from 0.1 μm to 0.3 μm or may be in different size depending on the design) and they are separated by a distance ‘a’ (known as pitch or lattice constant) 36 , which is equal to or greater than ‘2r’. Receptors 40 can be placed in-between the spaces of the rods 32 in hollow clad 33 .
[0051] Receptors 40 , shown in FIG. 3 (For example: ACh—Acetylcholine covers for nerve agents, AH—Aromatic Hydrocarbon, etc.) can be used inside the nano-chip 16 ( a, b, c, d, e ). Here, receptor 40 is used to detect the type of specimen and they absorb/interact with the respective specimen (e.g. biomolecule or chemical agents or biological cell) present in between the spaces of the dielectric rods.
[0052] Each rod 32 has a refractive index ‘n’ which can be either equal to ‘n core ’ or refractive index ‘n’ can be greater or less than the core refractive index n core ’. Optical signal input 14 to nano-chip 16 a is transmitted through the core 35 . Based on the absorption of the specimen (not shown here) by the receptor 40 located in the space between the rods 32 , the refractive index of the substrate ‘n sub ’ in combination with hollow clad 33 and receptor 40 is changed to ‘n eff ’, the effective refractive index, and as a result, the power output optical signal 18 is reduced. The concentration of the specimen can be determined by calculating the change of the refractive index of the receptors 40 after and before of absorption of the specimen and the changes in power of the optical signal 18 with respect to input optical signal 14 . Changes in power of optical signals between 14 and 18 can be determined by the power-factor, which is defined as the ratio of the output optical power over the input optical power. According to this invention, the main advantage is that by knowing the power factor, the changes in refractive index and also the concentration of the specimen can be determined. By calculating the power-factor, this proposed sensor would give the real-time concentration of the specimen.
[0053] Nano-chip 16 a used for system 22 is based on photonic-crystal and they are having different structures. Two-dimensional (2-D) or three-dimensional (3-D) photonic crystal can be used to fabricate the nano-chip 16 a . In FIG. 3A , the photonic crystal is formed based on the dielectric rods 32 . Alternatively, the photonic crystal can be also made from holes, periodically arranged inside the dielectric materials.
[0054] FIG. 4A shows a schematic, representing the enlarge view of an alternative nano-chip 16 b and FIG. 4B is the cross-sectional view of section BB′, as shown in FIG. 4A , according to this invention wherein the same numerals in FIGS. 4A and 4B represent the same parts in FIGS. 3A and 38 , so that repeated explanation is omitted here. Only difference in FIGS. 4A and 4B as compared with FIGS. 3A and 3B is that the photonic crystal is made from the dielectric rods 32 placed in hollow clad 33 , wherein the rods 32 is having the triangular lattice 44 .
[0055] FIG. 5A shows a schematic, representing the enlarge view of an alternative nano-chip 16 c and FIG. 5B is the cross-sectional view of section CC′, as shown in FIG. 5A , according to this invention, wherein the same numerals in FIGS. 5A and 5B represent the same parts in FIGS. 3A, 3B 4 A, and 4 B, so that repeated explanation is omitted here. The main difference in FIGS. 5A and 5B as compared with FIGS. 3A, 3B, 4A, and 4B is that the photonic crystal is based on the holes 51 periodically arranged inside the slab acting as the clad 53 , wherein the holes 51 are filled up with the receptors 40 and also the holes 51 is having the rectangular shaped lattice 50 . According to this invention, optical signal 14 is guided through the slab-type waveguide 48 located inside slab (or clad) 53 . Each hole 51 in nano-chip 16 c has a radius of ‘r’ and they are separated by a distance ‘a’ (also known as lattice constant) 52 . Inside each hole, receptors 40 are present to absorb/interact with the specimen/sample. 54 shows the cross sectional view of this nano-chip 16 c . The nano-chip can also be designed by making holes in a triangular shape. Specification of the radii of the holes ‘r’ and lattice constant ‘a’ 52 will be optimized depending on the size of the nano-chip 16 c.
[0056] FIG. 6A shows a schematic, representing the enlarge view of an alternative nano-chip 16 d and FIG. 6B is the cross-sectional view of section DD′, as shown in FIG. 6A , according to this invention, wherein the same numerals in FIGS. 6A and 6B represent the same parts in FIGS. 3A, 3B 4 A, 4 B, 5 A, and 5 B, so that repeated explanation is omitted here. The main difference in FIGS. 6A and 6B as compared with FIGS. 5A and 5B is that the nano-chip 16 d is also based on photonic crystal, but comprising with defects 56 in the holes periodically structure in the core 57 . “Defects in the holes,” means that the diameter of some holes is bigger than the diameter of the ‘regular’ holes, all structured periodically. According to this invention, the defects 56 can also be filled with the receptor 40 and they can be created either using of holes 56 , as shown in FIGS. 6A and 6B , or using of the solid rods having specific radius (not shown here).
[0057] FIG. 7 shows a schematic, representing the enlarge view of an alternative nano-chip 16 e , according to this invention, wherein the same numerals in FIG. 7 represent the same parts in FIGS. 6A and 6B , so that repeated explanation is omitted here. The main difference in FIG. 7 as compared with FIGS. 6A and 6B is that the nano-chip 16 e is based on the solid slab 58 acting as the clad and the core 59 to guide the optical signal 14 , comprises with holes as defects 60 arranged periodically inside core 59 forming photonic band gap structure. As mentioned earlier, any type of specimen can be detected and their concentration can be known after processing the output optical signal 18 from nanochip. Type and concentration of any specimen such as gases, biomolecules, or any biological cells can be detected by making them to absorb on corresponding receptor 40 to be used in the holes 60 .
[0058] The nano-chip 16 ( a, b, c, d, and e ), can be fabricated using dielectrics, semiconductor, or polymer materials. The dielectric material can cover all kind of materials having dielectric or optical properties (e.g. refractive index), such as glass, quartz, polymer etc. According to this invention, alternatively, the nano-chip can also be fabricated from semiconductor materials, such as Si, GaAs, InP, GaN, SiC, diamond, graphite etc. which can be fabricated using standard's IC fabrication technology. This nano-chip itself can be from rigid or flexible substrate.
[0059] The nano-chip can be fabricated by standard dry or wet etching to form the holes or rods embedded inside the solid or hollow substrate. Alternatively, this can also be fabricated using spin-coated polymer or preformed polymer. The low shrinkage in polymerization and the transparency of the synthesized polyurethane can also be used in fabrication of infiltrated inverse opal elastomeric photonic-crystal structures for the nano-chip according to this invention. The nano-chip 16 ( a, b, c, d, and e ) can have high-symmetry cross-sections and can allow integrated optical networks to be formed by only placing either the rods in air or air cylinders in the dielectric. The nano-chip 16 can also be fabricated in multiple layers by stacking the slabs on top of one another, separating them with a separator. According to this invention, the nano-chip 16 ( a, b, c, d, and e ) and surrounding circuitry can be made into the single chips using today's IC process technology.
[0060] The specific specimen can be detected using the nanochip with specific receptor. For example, Avidin Biotin which is the most common uses as a receptor for glycoconjugate analysis and DNA detection systems, can be used also as the receptor 40 in the nanochip 16 ( a,b,c,d, and e ). Single receptor agent or solution linked with other molecule acting as the receptor (for the specific specimen) can also be used as receptor 40 . For example, Dimethylsulfoxide (DMSO) solution containing 4 mg/ml of the heterobifunctional linker molecule succinimidyl-6-hexanoate (biotinamido) for a 1 hour at room temperature and the resultant receptor can be used as receptor 40 for DNA detection. According to this invention, the receptor 40 can be gel-type, solid, or solution based.
[0061] A derivation is given here for the generalized analytical equation for the nanochip described earlier in FIGS. 3 to 7 . This derivation helps to understand the insight of this current invention for high sensitivity sensor device. For simplicity in derivation, nano-chip, as shown in FIG. 7 , consisting of a ridge waveguide in the core formed by periodically structured PBG, is considered as the example and this nanochip can be considered as a linear system. The waveguide structure is considered to be optimized for providing almost same output optical power 18 for the specific wavelength of the optical input 14 . By knowing the output optical power the concentration of the specimen (e.g. biological cells, industrial gas, or biological cell agents) can be detected. According to this current invention, nano-chip is considered to be formed based on the 2-D photonic crystals. Related generalized equations, required for determining specimen concentration is described herewith. Noted here that type of specimen can be known from the specific receptor 40 , as explained earlier. The specific receptor is used for specific link or bond.
[0062] According to this invention, the waveguide structure is to be designed in such a way that maximum optical power for optical signal 18 is achieved (or very to optical power of input optical signal 14 ), and that condition (or optical power) can be considered as the reference (i.e. with specimen present) in the holes.
[0063] The symbol used in derivation is summarized in Table I.
[0000]
TABLE I
Description of the symbols used in derivation
Parameter
Description
n cref
Reference refractive index of the core
n ceff
Effective (new) refractive index of the core
N
Gladstone-Dale constant
P in
Input optical Power
P out
Output Optical Power
Power Factor = P out /P in
Ratio of output optical power and input optical
power
ρ ref
Reference density (air or filled with receptor)
ρ new
New density after specimen absorbed
Δ ρ
Change in density
[0064] For linear system with ridge waveguide, Power Factor, ratio of output optical power (P out ) to input optical power can be derived as follows:
[0000]
Power
Factor
=
P
out
P
in
=
1
-
n
cref
2
-
n
ceff
2
n
cref
2
-
n
clad
2
(
1
a
)
[0065] Where, n cref is the reference refractive index of the core with optimized waveguide. n ceff is the effective refractive index of the core and n clad is the refractive index of the clad. From Eq. (1a), coupling loss can be written as
[0000] Coupling Loss=1−Power Factor (1b)
[0066] Where, Coupling Loss is,
[0000]
Coupling
Loss
=
n
cref
2
-
n
ceff
2
n
cref
2
-
n
clad
2
(
1
c
)
[0067] From Eq. (1a), relationship between Power Factor and density of the gas can be derived. The relationship between n cref , reference core refractive index (with no gas condition) and ρ ref , reference density of receptor can be expressed by using of Gladstone-Dale relationship,
[0000] n cref −1=ρ ref ×N (2)
[0000] where, N is the Gladstone-Dale constant
[0068] As mentioned earlier, after sensing the gas, the density of the receptor ρ new , after absorbing the gas which changes the effective refractive index of the substrate, nceff (mentioned as new core effective refractive index). Similarly, nceff relates with ρ new as,
[0000] n ceff −1=ρ new ×N (3)
[0069] From Eqs. (2) and (3), this following expression can be derived:
[0000]
n
cref
-
1
n
ceff
-
1
=
ρ
ref
XN
ρ
eff
XN
(
4
)
[0070] From Eq. (4) n ceff expression can be derived as:
[0000]
n
ceff
=
1
+
(
n
cref
-
1
)
ρ
ref
ρ
new
(
5
a
)
[0071] After substituting Eq. (5a) into Eq. (1a), we get the new density as follows:
[0000]
ρ
new
=
[
n
cref
2
-
(
1
-
Power
Factor
)
(
n
cref
2
-
n
clad
2
)
-
1
]
ρ
ref
(
n
cref
-
1
)
(
5
b
)
[0072] Changes in density ρ can be expressed as,
[0000] Δρ=ρ new −ρ ref (6)
[0073] Concentration of the bio-agent in ppb, which is a function of the molecular weight and Δp, and ppb can be written as
[0000]
ppb
=
Δ
ρ
×
0.02
Molecular
Weight
(
7
)
[0074] After substituting Eq. (6) into Eq. (7), the concentration of gas in ppb can be expressed as:
[0000]
ppb
=
(
ρ
new
-
ρ
ref
)
0.02
Molecular
Weight
(
8
)
[0075] Now substitute value of ρ new in Eq. (8) and we can derive ppb, which is
[0000]
ppb
=
[
[
n
cref
2
-
(
1
-
Power
Factor
)
(
n
cref
2
-
n
clad
2
)
-
1
]
ρ
ref
(
n
cref
-
1
)
-
ρ
ref
]
×
0.02
Molecular
Weight
(
9
)
[0076] Alternatively, particularly for medical diagnosis purposes, the above calculations can instead be done to allow for sensing target biomolecules in a non-gaseous form, and at even lower concentrations, such as parts per billion (ppb).
[0000]
ppb
=
[
[
n
cref
2
-
(
1
-
Power
Factor
)
(
n
cref
2
-
n
clad
2
)
-
1
]
ρ
ref
(
n
cref
-
1
)
-
ρ
ref
]
×
(
0.02
)
Molecular
Weight
(
10
)
[0077] Potentially, biomolecules might be detectable in ppb or even further lower concentrations, such as parts per trillion or even quadrillion.
[0078] According to this invention, by knowing the power factor (which is ratio of power of optical out 18 to power of optical in 12 to and from the nanochip 16 , respectively to the optical input), and appropriate arithmetic signal processing, the concentration of the specimen can be known. According to this invention, the gas is considered, it can be also be used for biomolecule gas, or biomolecule cells, if corresponding receptor is used. From FIGS. 8 to 14 , the signal processing for detecting small change in power factor are given. FIGS. 15 and 16 explain the sensor device according to this invention.
[0079] FIG. 8 shows a schematic representing the nano-chip and its detection block diagram according to this invention wherein same numerals represents the similar parts shown in FIGS. 2, 3, 4, 5, 6, and 7 , so that similar explanation is omitted here. In FIG. 8 , the optical signal 18 from nano-chip 16 ( a, b, c, d , or e ) is detected by the (optical) detector 61 to convert into corresponding electrical signal 26 . The detector 61 should be selected based on the wavelength of the light used in the nano-chip. For example, for visible wavelength, Si-based photodetector can be used which can provide quantum efficiency close to 100% over visible wavelength. For Near infrared wavelength, III-V compound semiconductor based detector can be used.
[0080] Photodiodes can be used in either zero bias or reverse bias. In zero bias, light falling on the diode causes a voltage to develop across the device, which leads to current flowing in the forward bias direction. Diodes usually have extremely high resistance when reverse biased. This resistance is reduced when light of an appropriate wavelength incident onto the junction. Hence, a reverse biased diode can be used to generate the photo current. Circuit with reverse-biased detector is more sensitive to light than one with zero-biased detector.
[0081] The detector can be p-n junction based detector or avalanche photodiode (APD) detector, According to this invention; both type photodetector (p-n or APD) can be used. Only difference is there operational voltage. For example, APD requires high voltage and on the other hands, p-n junction requires low voltage. By using of APD, according to this invention, single photon level difference in optical power between input to nano-chip and output from nano-chip can be detected.
[0082] FIG. 9 shows the signal processing block diagrams according to this invention wherein same numerals represents the similar parts shown in FIG. 8 , so that similar explanation is omitted here. According to this invention, Electrical-processing circuit 28 , shown in FIG. 9 , comprises with electrical signal integration circuit 66 , filtering and sample-counter circuit 68 to remove electrical noise, and a read-out circuit 70 to store the data. Each of these blocks 66 , 68 , and 70 are explained in details in FIGS. 10, 11, and 12 . The electrical signal outputs from this signal-processing unit 28 are reference signal 29 ( a ) and signal 29 ( b ) after specimen absorbed by the nano-chip. In absence of specimen absorption, the electrical signals 29 ( a ) and 29 ( b ) are the same.
[0083] FIG. 10A shows the integrated circuit block in details, of the block diagrams, as shown in FIG. 9 , and FIGS. 10B and 10C are the waveforms of point A and B, as shown in FIG. 10A , according to this invention wherein same numerals represent the similar parts shown in FIGS. 8 and 9 , so that similar explanation is omitted here. The electrical integration circuit 66 means as shown in FIG. 10 is a part of the electrical processing circuits 28 . According to this invention, electrical integration circuit 66 means comprises with transimpedance amplifier (TIA) 72 , two sets of switches 77 and 78 , a an analog memory 74 to store the reference value as reference voltage 76 , and two sets of integrator circuits 73 ( a ) and 79 ( a ), two sets of comparators 73 ( b ) and 79 ( b ), and one differentiator 82 .
[0084] According to this invention, the signal 26 input to TIA 72 of the integrated circuit 66 to have the proportional voltage output V in . Initially, the switch S 1 77 is on and switch S 2 78 is off. While the Switch S 1 77 is on, the proportional voltage output Vin is directly feed through the analog memory 74 to store the initial voltage as the reference voltage 76 (output of analog memory 74 ). Noted here that the reference voltage V ref can be either same or greater than that the proportional voltage output V in . The reference voltage V ref is integrated by the integrator 73 ( a ) and its output is directly feed to the comparator 73 ( b ) whose other input is set to V ref . While the integrator 73 ( a ) output is reached to V ref , the comparator 73 ( b ) output will reset the Integrator 73 ( a ). The resultant waveform 63 from comparator 73 ( b ) is saw-tooth type waveforms as shown in FIG. 10B for the point A of FIG. 10A . The resultant waveform 63 is acted as the output of V ref and mentioned here as V out1 , while there is no absorption of the specimen in the nano-chip explained earlier. As soon as integration for the pre-desired cycle (explained later in FIG. 10B ) is completed, the switch S 1 77 is turned to OFF and at the same time S 2 78 is turned on and the output from the TIA 72 is directly feed to the differentiator 82 whose other input is output 76 from Analog memory 74 . The differences 80 , output from the differentiator 82 is similarly feed to the integrator 79 ( a ), whose output is again feed to the comparator 79 ( b ). Noted here that other input to the comparator 79 ( b ) is V ref . The resultant waveform 65 is also saw-tooth like waveform (mentioned as V out2 ), as shown in FIG. 10C (at point B) and it can be generated by the reset 81 , as mentioned earlier. The differences between two sets of circuits as shown in FIG. 10A after and before switch S 1 77 ON and OFF is that they process the signals without and specimen absorption, respectively. According to this invention, the output waveforms 63 and 65 comprises with stream of saw-tooth like waveforms 83 ( a ) and 83 ( b ) which can be processed for captured explained later in FIG. 12 .
[0085] FIG. 11A is an example of the schematic showing the Filter-circuit of processing circuits 28 blocks shown in FIG. 9 , according to this invention wherein the similar numerals represent the same parts as shown in FIGS. 10A, 10B, and 10C . The filter & sample-counter means block 68 is a part of the electrical processing circuit 28 and comprises with an common clock signal 84 , two sets of filters 85 ( a ) and 85 ( b ), and two sets of sample counters 86 ( a ) and 86 ( b ). Two sets are used to process the outputs 63 and 65 separately. The filter & sample-counter block 68 is used to convert the waveforms achieved from the reference value 63 (with no specimen present) and new value 65 (with specimen present). In FIG. 11A , “Filter” blocks 85 ( a ) and ( 85 ( b ) are used to avoid glitches of the signals generated from the integrated circuit, explained in FIG. 10A . The “Sampler & Counter” blocks 86 ( a ) and 86 ( b ) can be used to compare the values of “Filter” blocks 85 ( a ) and 85 ( b ) to the values from the integrated circuit 66 , in FIG. 10A .
[0086] FIGS. 118 and 11C show the output signals 63 and 65 with capture time at different points for example at 87 ( a ) and 87 ( b ). These two signals 63 and 65 will provide us with two saw-tooth based waveforms with different slopes; represent the output signal amplitude (not shown here). They can have the different time intervals for example, t 1 , t 2 , t 3 - - - t n , total of ‘tn’ for output signal 63 (no specimen absorption) and t 1 ′, t 2 ′, - - - t n , total of the same time ‘tn’ for output signal 65 (with specimen absorption) for analysis. Several techniques can be used to analyze the waveforms to detect the concentration of the specimen absorbed. According to this invention, certain capture point 87 ( a ) and 87 ( b ) in waveforms 63 and 65 , respectively, can be used at different intervals and different amplitude to avoid the noise, if any, presence in the signals. The output signals from sampler and counter circuits 86 ( a ) and 86 ( b ) after capturing can be the stream of the digital signals 88 as shown FIG. 11B , and 88 and 29 ( b ) as shown in FIG. 11A . The corresponding analog signals output from filter circuits 85 ( a ) and 85 ( b ) is an integrated signals 90 ( a ) and 90 ( b ), respectively.
[0087] FIG. 12 is the schematic showing an example of read-out circuit, a part of processing circuits 28 blocks shown in FIG. 9 , according to this invention wherein the similar numerals represent the same parts as shown in FIGS. 10A and 11A . The read-out circuit means 70 shown in FIG. 12 averages the waveforms and then stores in the memory. Signals 88 received for reference value, will be stored into a read-out circuit 70 , shown in FIG. 12 , which is a part of the electrical processing circuit 28 , as shown in FIG. 9 . Read-out circuit 70 could be one for each of the reference value or specimen value to store (not shown here). Alternatively, one read-out circuit for reference value store can also be used which is used in FIG. 9 as for example. Any number of bits can be used for read-out circuit. As for example, a 12-bit circuit is considered in FIG. 12 . This read-out circuit 70 can be fabricated utilizing standard CMOS process technology. For example, this read-out circuit can be fabricating with standard 350 nm, 3.3 volt, and thin-oxide digital CMOS process geometry or less. The data will come to each bit (1-12) 91 of pass-gate transistor for storage. After the data is stored in the transistor, read-out port 92 will give us the stored values as outputs 29 ( a ) for the reference value 88 . This circuit will have a ‘reset’ line 93 , so that we can flush out the older data, if necessary. This circuit can be single transistor CMOS, p and n-channel transistor CMOS, or capacitive based circuit, which can be fabricated using conventional CMOS technology. FIG. 13 is the schematics showing the block diagrams of the monitoring system, according to the invention, wherein the same numerals represent the same parts, explained in FIGS. 9, 10A, 11A, and 12 , so that repeated explanation is omitted here. This monitoring system 30 comprise of several blocks such as: “Divider for (1-Power Factor)” block 94 , Digital Signal Processing (DSP) unit 96 , Digital to Analog Conversion (DAC) block 100 , Radio Frequency (RF) Transceiver block 102 , Concentration Display block 104 and remote Station block 106 to monitor the analyzed value. The RF unit 102 is for remotely monitor the specimen.
[0088] The signals 29 ( a ) and 29 ( b ) from the processing circuit unit 28 feed to the divider circuit 94 to calculate (1-power factor), as shown in EQ. 9, and its resultant output signal 95 feeds to the n-bit digital signal-processing unit 96 , where n is the number of the bit. Other inputs to DSP unit are known parameters such as reference concentration (mentioned as background concentration of the specimen, if any), other required refractive indices related to the nano-chips, explained earlier. The DSP unit 96 is commercially available from various vendors or the unit can be fabricated with standard CMOS technology, depending on the specification criterion. This DSP unit 96 includes a system controller for coordination. The system controller of the DSP unit 96 may be chosen to be an n-bit RISC/CISC-type processor, which is commercially available by various vendors such as Texas Instrument, INtel. The processor and system controller may share a memory for program and data storage.
[0089] Output signals of the DSP block 96 , which are digital signals, can be converted into analog by using the “DAC” block 100 . Output signals from the “DAC” block 100 can be transmitted through the “RF Transceiver” block 102 . Signals from block 102 may be wirelessly monitored from the remote “Station” block 106 by using standard wireless protocol such as BLUETOOTH, 802.11a/b/g protocol or other proprietary protocols. The system can be embed with the standard (display) based monitoring unit 104 by feeding a part of DSP signal to the monitoring unit 104 to monitor in real time the concentration of the specimen.
[0090] According to this invention, whole processing unit can be made into a single chip and can be fabricated using standard IC technology. Alternatively, whole processing unit can be also build hybridly.
[0091] According to this invention, FIGS. 9 to 13 explain the signal-processing unit to monitor the specimen concentration. This is given for example only. Various signal processing ways (utilizing similar idea as shown in FIGS. 9-13 ) can be used to monitor the specimen concentration. For example, alternatively, single switch (single pole double through) can be used instead of using two switches (S 1 and S 2 ), explained in FIG. 10A . In addition, alternatively analog divider (not shown here) can also be used instead of using digital divider 94 , (shown in FIG. 13 ). Additional analog to digital converter may require converting the resultant analog signal after dividing by divider (not shown here).
[0092] According to this current invention, any microprocessor, FPGA, or ASIC circuit can be used instead of DSP to perform the DSP functionality. These are available from the commercial vendors. For example, microprocessor can be obtained from Intel, FPGA from Actel and Xilinx, and ASIC circuit could be custom designed for required functionality, and it can be off-shore design and manufacturing.
[0093] According to this invention, alternatively the read-out memory circuit can be made based on capacitive load. FIG. 14 shows a schematic diagram of an alternative read-out circuit, wherein same numerals represent the same parts as shown in FIG. 12 , so that repeated explanation is omitted here. The difference of read-out circuit as shown in FIG. 12 is that read-out circuit 118 in FIG. 14 is based on capacitive load 110 and a 1 to 1 switch 112 . The advantages of using this circuit are: low area and low power. At least one 1 to 1 switch 112 and at least one capacitive load 110 can be used for single bit of memory. Input signal 88 can be stored by each capacitor 110 and the stored values can be as output signal 29 ( a ) as a reference (initial) value.
[0094] According to this invention, the signal processing unit and the monitoring units both as shown in FIGS. 9 to 14 can be fabricated monolithically into a single chip. Standard Si-CMOS technology can be used for fabricating the signal processing and monitoring chip either in single chip form or multiple chips. The geometry of the silicon-CMOS technology can be ranged from 0.35 μm 20 nm or less. The divider 94 can be designed in different ways for example carry-save, Boolean, binary type or synthesis library specific type, depending on the desired performance and area.
[0095] FIG. 15 shows a schematic of the nano-sensing detection system unit according to this invention wherein the same numerals represent the same parts as explained in FIGS. 2 to 14 , so that repeated explanation is omitted here. The sensing means 120 comprises with at least one laser 12 connecting with electrical driver 122 through electrical connection 124 , splitter 126 , nano-chip 16 ( a, b, c, d, e ), at least one detector 20 , signal processing unit 130 , connecting with the external power supplies through connection 132 , and a common carrier substrate 134 . According to this invention, light 14 having fixed wavelength is made to couple to the 1×k splitter 126 (where k is the number of splitters which is at least one) to split the intesity of light 14 into k numbers and made to pass through the nano-sensor 16 ( a, b, c, d and e ). Alternatively, according to this invention, the splitter and nano-chip can also be designed to operate in broadband light. In that case, the waveguide is to be multi-mode to operate in broad spectrum of light.
[0096] The splitter can be designed based on the photonics crystals having rod or holes, arranged periodically to made photonic band gap structure. Both splitter and nano-chips can have the same photonic band gap structure or different, and they can be fabricated on the common substrate 136 . Alternatively, the splitter can be designed based on the homogeneous (solid) substrate (without photonics crystal) and the nano-chip can be based on photonic crystal base. Again, they can be fabricated onto the common substrate 136 , or both splitter 126 and nanochip 16 ( a, b, c, d and e ) can be fabricated in separate substrates, and afterwards hybridly packaged onto the common substrate (not shown here). To detect different types of specimens. For example different bio-molecules, different types of receptors can be used in the nanochips. The outputs from each nanochip are made to incident to the detector 20 to convert optical signal into corresponding electrical signals (not shown here). The electrical signal is processed by the IC 130 to determine the concentration of each specimen. The electrical IC 130 can be single chip or multiple chip based on the circuit means, as explained previously from FIGS. 9 to 14 . All electrical components can be made into the single chip. Optical chip comprising with the splitter and the waveguide, and single chip can be packaged on the common substrate 134 to make the small package of dimension below 1″×1″×0.5″ (W×L×H). A key feature of this system 120 is that multiple sensors can be fabricated on a single wafer 136 . Utilizing the multiple sensor help to detect multiple specimens at the same time. For example, one sensor can detect chemical agent sensor, the second can be a biomolecule sensor, and the third can be a biological cell detector, and so on. Other example could be a single sensor unit can detect different gases or different types of bio-molecules simultaneously in real time, and any combination thereof.
[0097] FIG. 16 is a schematic representing the small form-factor sensor system, according to this invention, wherein the same numerals represent the same parts, as explained in FIGS. 2 to 7 and 15 , so that repeated explanation is omitted here. The small form factor sensor system 138 comprises with two parts wherein first part is a passive section of the system and comprises with sample handler 140 , two waveguides 142 ( a ) and 142 ( b ) for incoming and outgoing optical signals 14 and 18 , respectively, and a common substrate 144 , and the second part is an active section of the system and it comprises with carrier substrate 146 , laser 12 , laser driver 122 , detector 20 , preamplifier 148 , signal processing integrator circuit 150 , and electrical connection 152 .
[0098] According to this invention, specimen 154 ( a ) is made to pass through the inlet 156 ( a ) of the specimen handler 140 and pass out the specimen 154 ( b ) from the outlet 156 ( b ). The passive section of the sensor system 138 is designed in a way that a portion of its internal section is made to expose to the nanochip 16 to make enough contact of the specimen while passing through this specimen handler 140 . The optical signal 14 is made to propagate through the nanochip 16 via waveguides 142 ( a ) and 142 ( b ) used for guiding the signals on the passive section of nano-chip 16 . For simplicity in handling and also for the purpose of reusage of the sensor system for long time, the passive section can be a separate section apart from the active section, and can be replaceable and easily stackable to the active section. Alternatively, both passive and active sections could be single section attached permanently. In FIG. 16 , an example of a small form-factor sensor system containing a single nano-chip 16 is shown for simplicity in drawing. This can cover also for m-number of sensors containing in passive section of the sensor system (not shown here) for m-number of specimens detection. In that case, at least one specimen handler can be used and each nano-chip can have with same or different receptors.
[0099] According to this invention, the active section of the sensor system 138 has signal transmitting section, OE (optical to electrical conversion), and signal processing units (not shown separately). Transmitting section comprises with the laser 12 and driver 122 , OE unit comprises with detector 20 and preamplifier 148 , and signal processing unit comprising with a chip 150 for further signal processing and monitoring. The signal processing chip 150 contains pre-processing unit, post processing, and monitoring units, explained earlier in FIGS. 9 to 14 . Transmitting, OE, and signal processing units are placed on the carrier substrate 146 and they can be hybridly integrated on carrier substrate 146 or fabricated monolithically as single chip. The carrier substrate 146 has the groove 158 , housed appropriate to the passive section holding. Under operation, both waveguides 142 ( a ) and 142 ( b ) are coupled to the laser 12 and detector 20 , respectively to transmit and receive the signals 14 and 18 to and away from the nano-chip. Source (e.g. laser diode or light emitting diode) 12 with specific wavelength or ranges of wavelength, appropriate to the refractive index of the nanochip 16 can be used and it can be electrically drived by the driver circuit 122 . The OE section has the detector 20 , having high sensitivity to the source light, can be used to convert the optical signal to electrical. The detector signal is amplified by the pre-amplifier 148 and processed by the chip 150 for post processing and monitoring the concentration of the specimen. The electrical connection 152 connects all electrical components to the external power supplies (not shown here). According to this invention, transmitter section, OE section, and signal processing section can be fabricated into a single chip utilizing the standard IC technology. Alternatively, each component in active section could be a separate component, hybridly integrated on the substrate (e.g. 146).
[0100] According to this invention, the nano-chip described from FIGS. 3 to 7 and FIGS. 14 and 15 , can be fabricated using any kind of substrates which cover, semiconductor, polymer, ceramic, exhibiting optical properties. Semiconductor cover Si, III-V or II-VI based compound semiconductors. The rods or holes, periodically arranged inside substrate and/or in waveguide to form the photonic crystal structure, can be made by utilizing standard wet or dry-etching process frequently using in IC manufacturing. Alternatively, electrochemical or photo-electro-chemical etching process can also be used to create the holes inside the substrate. According to this, alternatively air-spheres inside can also be used forming photonic crystal based nano-chip, and they can be made by conventional electrochemical process. For example, large scale of air-spheres in silicon, strong variation of the diameter with a length of the lattice constant can be made using photo-electro-chemical process for crating photonic crystal structure for the nanochip. Alternatively, porous material (semiconductor, insulator, polymer, or metal) having pores can also be used for fabricating nanochip. The waveguide and the substrate carrying the waveguide could be same kind of material or different material. Alternatively, nanochip can also be made from the combination of the nanoparticles deposited or synthesized on the substrate arranged in periodically.
[0101] Alternatively, according to this invention, the nanometer sized rods, wire or tubes can also be made from the carbon type materials (semiconductor, insulators, or metal like performances) such as carbon nano-tubes, which could be single, or multiple layered. They can be made using standard growth process for example, MOCVD, MBE, or standard epitaxial growth. According to this invention, the self-assembled process can also be used to make wires, rods, or tubes and their related pn-junction to increase the junction area. These tubes can be grown on the semiconductors (under same group or others), polymers, or insulator. Alternatively, according to this invention, these rods, wire, or tubes, can be transferred to the foreign substrate or to the layer of foreign substrate acting as a common substrate for waveguide for nano-chip. The foreign substrate or the layer of material can be any semiconductor such as Si, Ge, InP, GaAs, GaN, ZnS, CdTe, CdS, ZnCdTe, HgCdTe, etc. The substrate can cover also all kinds of polymers or ceramics such as AlN, Silicon-oxide etc. The material can be conductive or non-conductive.
[0102] According to this invention, different substrates can be used for making sensing device as shown in FIGS. 14 and 15 . For example, carrier substrate 134 and common substrate 136 for the splitter and nanochip can be same or both can be different substrate, in hybrid integrated together. Alternatively, the splitter used for the multiple nanochip can be fabricated from the separate substrate and integrated on the carrier substrate 134 . As a carrier substrate, substrate made of any kind of material such as semiconductor, ceramic, metal, or polymer can be used.
[0103] According to this invention, concentration measurement by determining the power factor is explained here. This nanochip based on photonics crystal can also detect the concentration by other methods, such as measuring the fringe-pattern by using of CCD camera and laser beam analyzer, or absorption spectrum of the optical output by spectroscopy. The concentration and type of the specimen can be known by comparing with the reference pattern for the case fringe pattern technique, and by comparing intensity and chemical absorption for the case of absorption spectrum technique. Turning now to FIG. 17 a - g , the chip made from photonic crystal (PC) structure (herein after mentioned as photonic crystal coupled waveguide as “PC-W”) can be fabricated in a number of ways. For example, this description will use Silicon Nitride (SiNx) based photonic crystal structures which have a refractive index of 1.5-2.0. FIG. 17 summarizes the procedure for preparing SiNx PC-W structure. A fused silica substrate 200 may be used as the common substrate to integrate multiple PC-W sensors. In FIG. 17 a , the functional SiNx material 201 is deposited either using PECVD or LPCVD. In FIG. 17 b , photoresist layer 202 is deposited on the SiNx. In FIG. 17 c , photoresist layer 202 is lithographically patterned followed by, in FIG. 17 d , the deposition of a thin layer of chrome 203 to serve as a mask for subsequent pattern transfer of the PC-W holes. With the residual photoresist removed via acetone liftoff, in FIG. 17 e , Cr mask on the remaining surface defines the areas that are to be etched in SiNx layer using anisotropic NF 3 dry etch, as shown in FIG. 17 f . The remaining chrome layer is then removed in FIG. 17 g . The structure shown in FIGS. 17 a - g are intended to show a cross-sectional view of the chip made from photonic crystal structure for bio-agents diagnosis.
[0104] The materials discussed above are, however, merely an example. Other material systems can also be used, for example, when desiring formation of a disposable test strip. In such a case, microfluidics based blood plasma filtration unit coupled with PC-W sensing platform may be provided as disposable plastic test strips. To keep the material and fabrication cost down for fabricating plastic based PC-W sensors and blood plasma filtration unit in a single microfluidic channel, replica molding procedure provides a low-cost alternative.
[0105] In addition to the PC-W structural design, surface treatment to covalently conjugate bioreceptors is a part of the sensor design and optimization. The key parameters of surface treatments that influence the biosensor performance include the orientation and surface coverage of the conjugated bioreceptors. Due to the glass-like surfaces of the SiNx and fused silica all-dielectric photonic crystal, typical surface treatment techniques from biochemistry such as chemical etching techniques, vapor or plasma deposition, and the formation of self-assembled monolayers (SAMs) can be utilized for immobilizing bioreceptor layer.
[0106] Silicon Nitride (SiNx) structure surface can be modified by using one of the two SAM organosilanes, i.e. 3-(2-aminoethylamino) propyltrimethoxysilane (for NH 2 grafting), or 10-(Carbomethoxy)decyl dimethylchlorosilane (for COOH grafting after activation with HCl). To perform the NH 2 silanisation the samples need to be placed in a solution containing methanol and acetic acid glacial, eventually adding the C 8 H 22 N 2 O 3 Si. For COOH grafting, the samples need to be immersed in a solution of C 14 H 29 ClO 2 Si dissolved in a mixture of CCl 4 and n-C 7 H 16 followed by final immersion of the samples in HCl solution. After successful silanization of the surface, the bioreceptors may be selectively immobilized through diffusion onto the sensor surface by placing several small drops of bioreceptors directly above the respective PC-W sensor units. The samples then need to be incubated and thoroughly cleaned to remove any unbounded bioreceptors onto the surface. To passivate the sensor surface from non-specific biomolecule binding, detergent blockers such as Tween-20, Triton X-100 or protein blockers such as Bovine serum albumin (BSA) may be used.
[0107] While it has previously already been mentioned that the above embodiments can be used to identify any number of biomolecules, a few specific applications are also beneficial. Specifically, an embodiment for sensing pathogens (such as Hepatitis B) or HIV can be created. FIG. 18 shows one such preferred embodiment, according to this invention. As shown in the FIG. 18 , when using the present invention to test for specific molecules within the human body, some additions and modifications to the structure are favorable. FIG. 18 shows, for example, where a portion of the device, 302 , is removable from the main body 300 . Here, a blood sample enters the inlet 304 on the test strip 302 , passes through a blood filtration system 306 , the PC-W sensing platform 308 , and then exits the strip through outlet 310 . The laser and laser source 312 are placed on the main body 300 in such a way as to direct the laser into waveguide 314 located on the test strip 302 . The laser signal then travels through the PC-W sensing platform 308 , exits out of waveguide 316 , and is sensed by the detector 318 on the main body of the device. The integrated circuit 320 converts the laser signal to an electrical signal, analyzes it, and displays the result in the display screen 322 . Connections between the various components are not shown in FIG. 18 .
[0108] FIG. 18 shows an additional component from those embodiments discussed previously (such as that shown in FIG. 16 ), known as a blood filtration system 306 . During measurement, a small volume of blood sample (e.g at least a drop) needs to be flow into the microfluidic channel (not shown). The microfluidic channel will include a filtration chip for extracting plasma from the whole blood sample. The filtration chip comprises microfluidic channels that use hydrodynamic forces to separate human plasma from blood cells. Individual filtration unit (not shown here as part of the blood filteration unit 306 ) comprises an inlet that is reduced by approximately 20 times to a small constrictor channel. This channel opens out to a larger output channel with a relatively small lateral channel for the collection of plasma. Studies have shown that this type of filtration unit was capable of removing 97.05±0.5 percentages of cells at 200 μl min −1 flowrate. The plasma from the filtration chip flows onto the PC-W sensing units through a dedicated channel allowing the target biomolecules to bind to the bioreceptors. Before the optical measurement, a stringent cleaning procedure using a buffer solution may be used to eliminate non-specific biomolecule interactions since they can negatively influence the output optical signal. The two waveguides, 314 and 316 , attached to the test strip facilitate the transport of the optical signals from the laser source to the PC-W sensing arrays and from there into the signal processing unit for data analysis. A small display unit 322 will be included for displaying the test results real-time. The integrated point-of-care diagnostic platform can be powered by conventional Li-ion batteries.
[0109] FIG. 19 in included as an example of a more detailed diagram from the generalized FIG. 18 , according to this invention. It is included merely as an additional aid to visualize possible embodiments, and is not intended to be limiting the present invention.
Pathogen-Sensing
[0110] The embodiment may be designed to have arrays of independent biosensing units coupled onto the PC-W platform, providing parallel detection of multiple biomarkers. While this is beneficial for all types of detection, this is especially beneficial when detecting certain pathogens, such as HBV, which have multiple detectable markers. Numerous HBV markers include hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), hepatitis B e antigen (HBeAg), hepatitis B e antibody (anti-HBe), hepatitis B core antigen (HBcAg), and hepatitis B core antibody (anti-HBc). For maximum accuracy, test strips may be designed to detect approximately five different HBV markers.
[0111] Although this embodiment specifically utilizes a blood filtration system, alternatively the embodiment might be designed to detect biomarkers in saliva, other body tissue, or other body fluid. If this is the case, then the blood filtration system may be omitted or replaced with a different type of filtration system. For example, due to the viscosity of saliva, movement through a simple sample inlet may be difficult. A microfluidic system may be used to aid the movement of the sample into the PC-W sensor platform, wherein a drop of fluid may able to flow by capillary force.
[0112] HIV-Sensing
[0113] Another alternate embodiment is one which is designed to detect HIV. The typical HIV diagnosis tests are based on the detection of antibodies produced by the human body in response to the HIV infection. For clinical laboratory-based HIV screenings, enzyme-linked immunosorbent assay (ELISA) is the first test conducted to look for HIV antibodies. If the test indicates the presence of HIV antibodies (positive), the test is again repeated to confirm the diagnosis. In the case of second positive ELISA result, a complementary test called Western blot is deemed necessary to confirm the diagnosis since it is more adept at distinguishing HIV antibodies from other antibodies present in the blood. The need for advanced technical skills and higher operating costs limits the use of Western Blot only to a confirmatory test. Although assay based techniques such as ELISA and Western Blot provide diagnostic results with high accuracy, their major shortcoming is the high number of false negative diagnostic results during the “window period. The 3-12 weeks period between the onset of HIV infection and the appearance of measurable antibodies to HIV seroconversion is known as the window period. Among high-risk populations, the current antibody tests are shown to miss about 10 percent of acute HIV infections by showing antibody-negative. Alternate HIV testing methodologies involve the detection of HIV antigen, or nucleic acid amplification testing (NAAT). Antigen testing looks for soluble p24 antigen, presumably following viral replication, and does not specifically identify live virus. The level of p24 antigen increases significantly during the initial phases of the infection, then declines to undetectable levels as they bind to HIV antibodies [Christine C. Ginocchio, HIV-1 Viral Load Testing Methods and Clinical Applications, laboratory medicine (2001), 32 (3), 142-152). Since the estimated average time from detection of antigen to detection of HIV antibodies is 6 days and not all recently infected persons have detectable levels of p24 antigen, HIV diagnosis using stand alone p24 antigen test is strongly discouraged, nucleic acid amplification testing (NAAT) procedure widely used for screening donated blood detects one or more of several target sequences located in specific HIV genes and can provide diagnosis much earlier than the antibody test. However, the drawbacks to NAAT testing include: need for sophisticated instrumentation, high operating costs and unaffordable in remote and non-laboratory settings. Therefore, there is still a strong need to develop a cost effective, laboratory-free diagnostic system that can detect acute HIV-1 in-house or in-remote settings of developing countries without the need for trained technicians or advanced facilities.
[0114] As described above, currently, HIV diagnosis in general is costly, and additionally inaccurate during the initial window after infection, and most importantly takes long time to get diagnosis results.
[0115] According to this invention, this embodiment is a diagnostic system that can diagnose HIV infection within the window period based on parallel detection of two characteristic HIV-1 biomarkers, i.e. HIV-1 Tat protein and HIV-1 antibodies (here in referred as antibodies). Tat protein is a primary HIV gene that regulates the early stage replication of HIV, whereas antibodies are produced by the body in order to combat the assortment of proteins produced by HIV infection. Bioreceptors are biomolecules attached to the transducer surface based on their high specificity towards target specimen to form a functional sensor. According to this invention, bioreceptors are used for TAT protein detection which provide the information on even before window period condition of the patient.
[0116] The multi-analyte diagnostic platform is based on biosensing device platform, as described previously in FIGS. 3 to 7 and also FIGS. 15, 16, 18, and 19 for measuring the miniscule refractive index changes when the biomarkers in the sample bind to the characteristic bioreceptors. The integration of blood plasma separation, optical biosensing and data processing assembly on the same platform makes possible the development of a sample-to-answer system with automated data analysis providing a rapid diagnostic readout (<30 min). In addition, the use of robust bioreceptors that have high storage stability at ambient conditions offers the potential to use the proposed diagnostic system in remote settings without cold storage facilities.
[0117] Structurally, the embodiment for detecting HIV may be very similar to that of the embodiment for detecting pathogens. It may utilize the same disposable plastic test strips and blood filtration system, and the only significant difference would be the biomarkers used in the photonic crystal arrays.
[0118] Detection of HIV can be done through detection of two indicators: HIV-1 Tat proteins or HIV-1 antibodies. For the detection of HIV-1 Tat protein, as shown in FIG. 20A , one may use an aptamer that binds to the Tat protein with two orders of magnitude greater (133-fold) affinity over the TAR RNA of HIV-1. Recently developed two aptamers: Probe aptamers-RNA Tat and aptamer-derived second strand (5′-UCGGUCGAUCGCUUCAUAA-3′-NH 2 and 5′-GAAGCUUGAUCCCGAA-3′ respectively) may be used to function as bioreceptors for the detection of real HIV-1 Tat protein extracted from blood. At first, the probe RNA Tat aptamers are covalently attached to the photonic crystal surface of the PC-W sensing platform. Once exposed to a blood sample, any present HIV-1 TAT proteins bind to the probe aptamers along with aptamer-derived second strands, thereby forming duplex structures. The high storage stability of aptamers even at ambient conditions can be used to develop diagnostic systems that do not require refrigeration to maintain their detection performance. Alternatively, a simple annealing step at 70° C. for 3 min may be used to recover the functional activity of immobilized aptamers upto 90%.
[0119] Alternately, on the other hand, for the detection of HIV-1 antibodies, HIV proteins called antigens, shown in FIG. 20B , may be used as bioreceptors. The antigens are covalently attached to the biochips sensing platform (as described previously). Once exposed to a blood sample, any present HIV-1 antibodies bind to the antigens.
[0120] For maximum accuracy in testing, the embodiment may be designed, similarly to the HBV detector, with multiple independent parallel biosensing units, wherein each unit detects a different biomarker.
[0121] Whereas many alterations and modifications of the present invention will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description, it is to be understood that the particular embodiments shown and described by way of illustration are in no way intended to be considered limiting. Therefore, reference to the details of the preferred embodiments is not intended to limit their scope. Although the invention has been described with respect to specific embodiment for complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modification and alternative constructions that may be occurred to one skilled in the art which fairly fall within the basic teaching here is set forth.
[0122] The present invention is expected to be found practically use in the industrial, commercial, and bio-medical application. Using of such sensor device will help to detect very low level concentration (in ppb level) of gases, requiring in industrial application. This sensor devices is not limited to use in chemical gas, bio-molecule gas only, this can also be used in biological cell detection and their low level concentration measurement. The main advantages of this invention are that detection and concentration of multiple specimens at a real time can be possible. Multiple specimens can be multiple gases, multiple bio-molecules, or multiple bio-logical cells, or their combinations.
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This invention relates to a system and methods including their manufacturing technologies for enhanced sensing capability of one or more bioagents covering from HIV, Pathogens, virus, to cells detection. More particularly, this invention is related to HIV and pathogen diagnosis system and methods which may increase its sensitivity and may reduce the diagnosis time. Furthermore, the diagnosis system and method may be applicable to all early stage patients with various age groups, where early and accuracy in diagnosis, are required.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a reservoir and a system for mounting this reservoir on a support part. The invention is especially applicable to a brake fluid reservoir and the system for mounting it on a brake master cylinder.
[0002] In a motor vehicle braking system, a brake fluid reservoir is mounted on the upper portion of a brake master cylinder in order to provide a reserve of fluid with a view to compensating for any reduction in the volume of fluid in the hydraulic braking circuit of the vehicle. The brake master cylinder is itself mounted on a braking assistance servo which is controlled by the brake pedal.
[0003] There are various methods for mounting a reservoir on a brake master cylinder. In particular, some reservoirs are mounted using one or more mounting elements, such as pins or bolts, which pass through mounting lugs provided in the lower portion of the reservoir and mounting lugs which are provided on the upper portion of the brake master cylinder.
[0004] However, these mounting elements must be immobilized using, for example, nuts for the bolts. The fitting and removing of the reservoir therefore require tools and a certain amount of time.
SUMMARY OF THE INVENTION
[0005] The invention relates to a mounting system that facilitates the fitting and removing of the reservoir.
[0006] The invention therefore relates to a brake fluid reservoir comprising at least two lateral mounting lugs designed to be placed either side of a central mounting lug of a support device. These lateral lugs include two collinear holes designed to receive a mounting pin, itself designed to pass through a central lug of the support part. According to the invention, it is envisaged that the mounting lugs include at least one device for the axial immobilization of the pin.
[0007] Advantageously, it is in particular envisaged that the holes in the lateral lugs include wider sections located on the side of the faces of the lateral lugs which are designed to be in contact with the central lug of the support part. These wider sections are designed to confine the mounting pin placed in the said holes.
[0008] The invention also relates to a mounting device attaching the reservoir hereby designed. It includes a spring device pressing both on a lower face of the reservoir and designed to press on an upper face of the support part so as to move the reservoir away from the support part in a specific direction of movement. The pin placed in the said holes is then designed to have its ends placed inside the wider sections.
[0009] The depth of the wider sections measured along the axis of the holes is such that the sum of the depths of the wider sections in the two lateral lugs plus the distance between these two lateral lugs is greater than the length of the pin.
[0010] It is envisaged that each wider section is located at least on the side opposite to the said direction of movement in relation to the axis of the holes.
[0011] According to a beneficial embodiment of the inventive system, the spring device includes a spring washer placed between the reservoir and the support part.
[0012] In order to produce this embodiment, it can be envisaged that the reservoir include a stud located under the lower face of the reservoir and going into a hole in the support part and that the washer include a sleeve placed around the stud, the said sleeve ending in a deformable elastic flange which is designed to be in contact with the lower face of the reservoir.
[0013] The invention is more particularly applicable to the mounting of a brake fluid reservoir on a brake master cylinder. The support part is then a brake master cylinder including, on its upper portion, a central mounting lug located on the longitudinal axis of the master cylinder.
[0014] In such an application, it can be envisaged that the said washer be placed around a reservoir outlet and around a brake master cylinder inlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The various objectives and features of the invention will emerge more clearly from the description which follows and from the accompanying figures in which:
[0016] FIGS. 1 a to 1 c illustrate a simplified embodiment of a system according to the invention;
[0017] FIGS. 2 a to 2 c illustrate a detailed embodiment of a mounting system according to the invention; and
[0018] FIGS. 3 a and 3 b illustrate an example of a spring device for rendering the system in FIGS. 2 a to 2 c operational.
DETAILED DESCRIPTION
[0019] With reference to FIGS. 1 a to 1 c , a simplified embodiment according to the invention will first be described.
[0020] FIG. 1 a illustrates a brake master cylinder allowing the invention to be used. This master cylinder 2 includes two inlets 27 and 28 for connecting with the inside of the master cylinder and introducing brake fluid with a view to filling the vehicle's hydraulic braking circuit. A mounting lug 20 including a hole 21 is provided in the upper portion of the master cylinder. Studs 25 , 25 ′ including blind holes 24 , 24 ′ are also provided, the use of which will be explained later.
[0021] The lower portion of FIG. 1 b illustrates a brake master cylinder 2 such as the one in FIG. 1 a and the upper portion of FIG. 1 b illustrates a brake fluid reservoir 1 designed to be mounted on the master cylinder 2 .
[0022] The reservoir 1 includes outlets 31 and 32 designed to be fitted into the inlets 27 and 28 of the brake master cylinder so as to connect the inside of the reservoir with the inside of the master cylinder. Two mounting lugs 10 and 11 provided on the lower portion of the reservoir are designed to be placed either side of the master cylinder central mounting lug 20 as illustrated in FIG. 1 c . Two studs 17 and 17 ′ are also provided on the lower portion of the reservoir and are designed to fit into the holes 24 , 24 ′ in the studs 25 , 25 ′ on the master cylinder.
[0023] As indicated by the dotted-line arrows on FIG. 1 b , the reservoir 1 is placed on the brake master cylinder 2 so as to obtain the assembly in FIG. 1 c.
[0024] The holes, such as the hole 12 , in the reservoir lugs are aligned with the hole 21 in the lug 20 of the master cylinder and a pin is inserted in these holes (see FIG. 1 c ).
[0025] FIGS. 2 a to 2 c illustrate a method for mounting a reservoir on a brake master cylinder using a pin.
[0026] In these figures is shown the master cylinder central lug 20 and the lateral lugs 10 and 11 of the reservoir disposed on either side of the lug 20 . The holes 12 and 13 in the lugs 10 and 11 and 21 in the lug 20 are put essentially into alignment.
[0027] The holes 12 and 13 include wider sections 14 and 15 located toward the faces of the lugs 10 and 11 which are near or even in contact with the central lug 20 .
[0028] In FIG. 2 a , a pin 3 is engaged in the holes 13 and 21 .
[0029] In FIG. 2 b , the pin is put in place at the center of the device.
[0030] In FIG. 2 c , the lateral lugs 10 and 11 (that is to say the reservoir) have been displaced upward in the direction of the arrow F. The pin is then located in the wider sections 14 and 15 of the holes in the lugs 10 and 11 , and the pin cannot come out of the holes in which it has been placed.
[0031] The length L of the pin is less than the sum of the depths P 1 and P 2 of the wider sections plus the distance E separating the two lugs 10 and 11 .
[0032] It should be noted that, in order to facilitate the insertion of the pin in the hole 21 in the lug 20 , the ends of the hole 20 are countersunk, at an angle of 45 20 for example, so that the pin can be put in place even if the hole 21 is not perfectly in alignment with the holes 12 and 13 .
[0033] FIGS. 3 a and 3 b illustrate a system making it possible to push the reservoir 1 in the direction of the arrow F. The studs 17 and 17 ′ ( FIG. 1 b ) are fitted with sleeves made of elastic material. Thus in FIG. 3 a , a seal 4 generally cylindrical in shape having a sleeve 40 which is placed around the stud 17 . This sleeve has at its upper portion an elastic flange 40 .
[0034] During the fitting of the reservoir on the brake master cylinder, the studs such as 17 are inserted in the holes such as 24 in the master cylinder. We therefore have the situation illustrated in FIG. 3 a.
[0035] The upper flange 40 of the sleeve 4 has at its upper portion, a larger diameter so that by pressing on the reservoir in the opposite direction to the arrow F, the upper portion of the flange is compressed by the lower face of the reservoir and moves away from the axis of the stud 17 . This situation is illustrated in FIG. 3 b . This upper portion of the flange 40 offers resistance to the pressure exerted on the reservoir from the top toward the bottom. In the situation illustrated in FIG. 3 b , the pin 3 can be inserted in the holes 12 , 21 and 13 as previously described. When the pressure on the reservoir is released, the flange 40 , due to its elasticity, pushes the reservoir upward in the direction of the arrow F and the pin is confined in the wider sections 14 and 15 according to the situation illustrated in FIG. 2 c.
[0036] In a variant embodiment not illustrated in the figures, the sleeves, such as the sleeve 4 , can be fitted into the master cylinder inlets 27 and 28 . The reservoir outlets 31 and 32 are designed to be placed in these sleeves. As previously, during the fitting of the reservoir on the master cylinder, the upper portion of the flange 40 of each sleeve is compressed by the lower face of the reservoir and moves away from the axis of the corresponding outlet 31 , 32 .
[0037] The upper portion of the flange 40 offers resistance to the pressure exerted on the reservoir from the top toward the bottom and when the pressure on the reservoir is released, the flange 40 , due to its elasticity, pushes the reservoir upward in the direction of the arrow F and a pin placed in the holes 12 , 13 , 21 is confined in the wider sections 14 and 15 .
[0038] In this variant embodiment, the studs 17 and 17 ′ of the reservoir and the blind holes 24 and 24 ′ provided in the master cylinder and designed to receive the studs 17 and 17 ′ are not required.
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The invention relates to a brake fluid reservoir comprising at least two lateral mounting lugs ( 10, 11 ) designed to be placed either side of a central mounting lug ( 20 ) of a brake master cylinder. Collinear holes ( 12, 13, 21 ) traverse these lugs and are designed to receive a mounting pin ( 3 ). The said lugs include at least one device for the axial immobilization of the mounting pin ( 3 ). Applications: brake fluid reservoir mounting.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application No. 60/679,168 filed May 9, 2005.
STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The present invention relates to mixing valves. More particularly it relates to thermostatic mixing valves with improved access to check valves and filter screens and improved settings for comfort temperatures.
Thermostatic mixing valves can provide a source of water having a desired temperature and can maintain the desired water temperature substantially constant once set. Such devices are well known in the art. See e.g. U.S. Pat. No. 6,279,604 and U.S. patent application publication 2004/0000594. Typically, the desired water temperature is obtained by controlling the relative proportions of hot and cold water admitted to a mixing chamber and adjusting the relative proportions to maintain the desired water temperature substantially constant.
To prevent the temperature from being set at a temperature that risks scalding, a temperature stop is typically provided on the mixing valve. The valves often also include a method for setting a lower “comfort” level.
To prevent cross flow between the hot and cold input lines, check valves can be provided between the hot and cold water supplies and the mixer valves. Also, screens can be provided to avoid debris from clogging the valve interior.
While thermostatic mixing valves are known in the art, these known devices suffer from a number of disadvantages. For example, in some prior art devices, when the comfort level is selected, the maximum temperature selection is determined by a fixed increment therefrom. In any event, to properly maintain the valve, the check valves and associated screens need to be periodically cleaned. This process can require the use of a number of tools, requires some skill, and can be time consuming.
Therefore, there remains a need for an improved thermostatic mixer valve in which the check valves and screens are easily and quickly cleaned. Furthermore, there remains a need for an improved thermostatic mixer valve that mechanically provides a user selectable comfort level independent of the maximum temperature level.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a mixing valve comprising a valve body having a check valve receptacle coupled to an inlet water passage and also an outlet water passage, and a check valve insert sized and dimensioned to be received in the check valve receptacle. The check valve insert has a stop body with a shutoff element and a check valve sized and dimensioned to be received in the stop body, wherein the stop body is selectively movable in the receptacle to position the shutoff element to decouple the inlet water passage from the outlet water passage. When so positioned, the check valve is selectively removable from the stop body for service.
In preferred forms, the stop body and check valve each include a receptacle sized and dimensioned to receive a single tool, such that the water flow can be deactivated and the check valve removed with the selected tool.
In another aspect of the invention, an assembly for setting an output temperature for a thermostatic mixer valve is provided. The assembly includes a thermostatic mixing cartridge having an undercap, an overcap including a first detent member, and a rotational stem adaptor coupled between the undercap and the overcap and having a second detent member. The first detent member and the second detent member interact to provide a comfort temperature setting.
In a preferred form of the invention, the undercap includes a maximum stop temperature tab. The rotational stem adaptor includes a tab for mating with the maximum stop tab to limit the output temperature to the selected maximum.
In another preferred form, the undercap can include a first plurality of teeth, and the overcap can include a second plurality of teeth that mate with the first plurality of teeth.
In another preferred form, the first detent member can be a ramp. The second detent member can be a flexible tab.
Thus, the present invention provides improved methods and apparatuses for maintaining or servicing check valves in a mixing valve, as well as improved means for selecting a comfort level temperature when the valve is a thermostatic mixing valve.
These and still other advantages of the present invention will become apparent from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there are shown preferred embodiments of the invention. Such embodiments do not represent the full scope of the invention, and reference is made therefore, to the claims herein for interpreting the full scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially exploded perspective view of a valve of the present invention, illustrating the thermostatic cartridge assembly and sealing gaskets;
FIG. 2 is a partial view of the valve of FIG. 1 , illustrating the drive lid for the service stop in the closed position;
FIG. 3 is a view taken along the line 3 - 3 of FIG. 1 , illustrating the check valve insert in the open flow position;
FIG. 4 is the same view as FIG. 2 , but illustrating the service stop drive in the open position, allowing for the removal of the check valve;
FIG. 5 is a view taken along the line 3 - 3 of FIG. 1 illustrating the check valve insert in the closed flow position;
FIG. 6 is a view taken along the line 3 - 3 of FIG. 1 illustrating the check valve removed from the valve body for service;
FIG. 7 is a view similar to FIG. 1 , but with temperature setting assembly exploded;
FIG. 8 is an exploded view of the bottom of the stem adaptor of FIG. 7 received in the bottom of the detent cap of FIG. 7 ;
FIG. 9 is a view taken along the line 9 - 9 of FIG. 1 , illustrating the relative positions of the components at a maximum temperature;
FIG. 10 is a view taken along the line 9 - 9 of FIG. 1 , illustrating the relative positions of components when the temperature is below the comfort level; and
FIG. 11 is a view taken along the line 9 - 9 of FIG. 1 , illustrating the relative positions of components when the comfort level is being reset.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures, a thermostatic mixer valve 10 includes a valve body 12 having cold and hot water inlets 14 and 16 respectively, and upper and lower water outlets 18 and 20 respectively. Check valve inserts 22 and 24 providing check valves (and filter screens) for each of the hot and cold water inlets 16 and 14 are received in check valve receptacles (service stop receptacles) 49 provided in the valve body 12 . The valve body 12 further includes a cartridge chamber 26 for receiving a thermostatic cartridge assembly 27 , including both a thermostatic mixer cartridge 36 , and a temperature setting assembly 74 adapted to receive a knob or other actuator for selecting a temperature level.
The cartridge 36 includes cold and hot water inlets 28 and 30 and associated sealing gaskets 32 and 34 which are received in the valve body 12 , and adjusts the temperature of the water supplied to the outlets 18 and 20 based on a position selected by the temperature setting assembly 74 in a manner known in the art. While a number of thermostatic mixer valve cartridges could be used in the present invention, one such cartridge is disclosed in U.S. patent application publication 2004/0000594, which is hereby incorporated herein by reference for its description of such devices. When using the described cartridge, the cartridge can be rotated one hundred and eighty degrees to reposition the hot and cold inlets, thereby allowing a user to account for errors in plumbing the pipes and various other situations in which the hot and cold inputs have been reversed.
Referring now to FIGS. 2 and 3 , the check valve insert 24 is inserted in a check valve receptacle 49 . The check valve receptacle 49 is sized and dimensioned to receive the check valve insert 24 , and includes an upper portion 53 that is threaded on the inside surface. Access ports are provided from the receptacle 49 to a water out passage 64 and a water in passage 66 , such that water flows from the inlets 14 and 16 into the water passage 66 to the check valves 60 , and out the water passage 64 to the cartridge 36 in normal operation.
Referring still to FIG. 3 , the check valve insert 24 includes a service stop body 56 and a check valve 60 , which is received in the service stop body 56 . The service stop body 56 includes an upper portion with a radially-extending lip 68 that is threaded to mate with the upper portion 53 of the check valve insert 24 , and a shutoff disc 70 at the opposing end in the receptacle 49 . The lip 68 is positioned a distance from the top of the body 56 selected to locate the shutoff disc 70 to decouple the water inlet passage 66 from the water outlet passage 64 when servicing the check valve 60 as described below. To assure appropriate sealing, the shutoff disc 70 includes a rubber o-ring 71 . An inner surface 73 of the upper portion of the body 56 is also threaded to receive the check valve body 58 .
Referring still to FIG. 3 , the check valve 60 is received into a check valve body 58 having a threaded upper portion 61 that mates with the threaded inner surface 73 of the upper portion of the service body 56 , and a filter screen 62 . A receptacle 54 is substantially centered in the check valve body 58 and is sized and dimensioned to receive a driving tool such as a ⅜″ socket driver for threading the check valve body 58 into and out of the service body 56 .
Referring still to FIG. 3 , and again also to FIG. 2 , the service stop body 56 includes a hinged drive lid 48 that is coupled to the top of the service stop body 56 by a hinge 51 . The drive lid 48 includes a receptacle 50 , substantially centered in the drive lid 48 , and also sized and dimensioned to receive the driving tool described above. A bracket 52 coupled to the valve body 12 extends over the edge of the check valve receptacle 49 , and is positioned to interact with the radially-extending lip 68 from the service stop body 56 to limit motion of the service body 56 from the receptacle 49 for service. Referring now to FIG. 4 , when the lid 48 is pivoted along hinge 51 , the receptacle 54 in the check valve 60 can be accessed, and the tool inserted to remove the check valve body 58 and check valve 60 .
To access the check valve 60 for service, the driving tool is inserted into the receptacle 50 in the drive lid 48 and the service stop body 56 is threaded counter-clockwise (upward) along the upper portion 53 of the check valve insert receptacle 49 until the lip 68 reaches the bracket 52 , moving the check valve insert 24 from the position shown in FIGS. 2 and 3 to that shown in FIGS. 4 and 5 . When the bracket 52 is reached, the shutoff disk 70 and associated rubber o-ring 71 are positioned in the check valve receptacle 49 to decouple the water input passage 66 from the water output passage 64 , thereby preventing water flow into the receptacle 49 and effectively shutting off the valve 10 , as shown in FIGS. 4 and 5 .
When the valve is shut off, the check valve 60 and associated filter screen 62 can be removed as shown in FIG. 6 by inserting the same driving tool that was used to move the service stop body 56 into the receptacle 54 in the check valve 60 . By providing the same receptacle in each of the service stop body 56 and check valve body 58 , only one tool is required to remove the check valve body 58 . After service is complete, the driving tool is again used to re-insert the check valve body 58 into the service stop body 56 , and to drive the service stop body 56 back into the receptacle 49 , and therefore to the position shown in FIG. 3 .
Referring now to FIG. 7 , the thermostatic cartridge 36 includes a drive spindle 37 and undercap 29 to which the temperature setting assembly 74 is connected. The temperature setting assembly 74 includes a rotational stem adaptor 38 , overcap 40 , a wave compression spring 42 and a retaining nut 44 . The undercap 29 of the thermostatic cartridge 36 further includes a plurality of teeth 31 extending radially around the circumference of the cartridge 36 , and which mate with teeth 41 in the overcap 40 . A pair of rotational stop tabs 33 and 35 are provided on the undercap 29 coupled to the thermostatic mixer cartridge 36 to provide a minimum and a maximum temperature position for the temperature setting assembly 74 , and therefore to limit the rotation of the assembly and the temperature of water obtained from the valve 10 .
The stem adaptor 38 is received between the detent cap 40 and the thermostatic cartridge 36 and is maintained in position by a fastener 46 received in an aperture 47 in a distal end of the spline adaptor 38 . The retaining ring 44 is received over the overcap 40 , and is threaded into the cartridge chamber 26 . The wave compression spring 42 is positioned between the overcap 40 and the retaining ring 44 , and provides a force on the overcap 40 to maintain the overcap 40 against the drive spindle 37 of the thermostatic cartridge 36 , and to maintain the teeth 31 mated with the teeth 41 .
Referring still to FIG. 7 and also to FIG. 8 , the stem adaptor 38 includes a rotational stop tab 39 that mates with the minimum and maximum temperature tabs 33 and 35 in the cartridge 36 to provide a rotational stop of minimum and maximum temperature, and a detent member in the form of a comfort temperature tab 43 . The comfort tab 43 extends radially from the outer circumference of the adaptor 38 , and is substantially centered adjacent an elongate aperture 76 inset from the outer edge of the spline adaptor 38 . The aperture 76 allows the tab 43 to “flex” inward and outward, as described below.
Referring still to FIG. 8 , the overcap 40 is substantially cylindrical in shape, including a plurality of teeth 41 extending radially outward and sized and dimensioned to mate with the teeth 31 on the cartridge 36 at a variety of possible positions. A mating detent member, here a ramp 72 , is also provided extending from an inner surface of the detent overcap 40 , and positioned a distance above the teeth 41 . When assembled, the ramp 72 interacts with the comfort temperature tab 43 on the rotational stem adaptor 38 to provide an indication to the user when the comfort position is key reached, also as described below. This is in the form of resistance to turning. However, further turning past this point is still possible.
Referring now to FIGS. 9-11 , a cutaway view of the temperature setting assembly 74 taken along the line 9 - 9 in FIG. 1 is shown as the assembly 74 is moved to varying positions. Referring first to FIG. 9 , here the tab 39 on the rotational stem adaptor 38 is shown in contact with the maximum temperature tab 35 on the cartridge 36 , indicating that the maximum temperature has been reached. Although a number of different temperatures can be selected, a maximum anti-scald temperature of 120 degree Fahrenheit is typical.
Referring now to FIG. 10 , here the temperature setting assembly 74 is shown rotated to a new position, and the comfort tab 43 is shown approaching the ramp 72 in the cap 40 . The comfort tab 43 follows the ramp 72 to a high point 78 at which the user will feel the tab 43 fall off of the ramp 72 indicating that the selected comfort temperature has been reached. As the tab 43 is moved along the ramp 72 , the aperture 76 formed in the adaptor 38 following the outer surface of the adaptor 38 allows the bottom surface of the rotational stem adaptor 38 to flex inward. Therefore, the tab 43 can move radially inward as it follows the ramp 72 and flex back out as it passes the high point 78 . The comfort tab 43 does not provide an actual “stop”, but can be moved past the comfort position if desired. Rotation would then be allowed to continue until the tabs 35 and 39 meet, as discussed above.
Referring now to FIG. 11 , the relative position of the components in the temperature setting assembly 74 are shown as an adjustment to the selected comfort temperature is made. To adjust the selected temperature, a user pulls on the overcap 40 axially to remove the teeth 41 in the overcap 40 from the teeth 31 in the undercap 29 of the cartridge 36 . When the teeth are disengaged, the overcap 40 can be rotated to a new position, to reposition the ramp 72 relative to the stops 33 and 35 . When the ramp 72 is in the position selected by the user, the overcap 40 is released so that the teeth 31 re-engage with the teeth 41 . The point 78 is therefore repositioned, providing an adjustment in the selected comfort temperature, while the stop tabs 35 and 39 remain in the same orientation, thereby maintaining the selected maximum temperature irrespective of the selected comfort temperature. The wave compression spring 42 maintains a force on the detent overcap 40 to assure that the teeth 31 and 41 are engaged.
The invention therefore provides a number of advantages. The check valve inserts provide check valves concentric with a shut-off device, which helps to reduce the overall size of the valve. The check valves, moreover, can be serviced with a single tool, thereby simplifying maintenance of the valve. Furthermore, servicing can be done by even those with minimal plumbing skill. Further, a comfort temperature selection is provided which allows the user to select a comfort level setting without affecting the maximum temperature.
It will be appreciated that a variety of changes can be made to this structure without departing from the spirit or scope of the invention. For example, although a specific driving tool is described above, various other tools could also be used. Additionally, although the valve is shown and described as providing only a temperature mixing function, volume controls can also be integrated with the valve, particularly in the inlet and outlet ports. Still other modifications could be made within the scope and spirit of the invention.
INDUSTRIAL APPLICABILITY
Disclosed are mixer valves useful in shower and other bathing installations.
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A mixer valve includes a rotational assembly for selecting a temperature of the water up to a maximum temperature. The rotational assembly includes a selectable “comfort” temperature indicator, that can be set independently of the maximum temperature, and does not affect the maximum temperature. The valve also includes check valves for preventing cross flow between the hot and cold pipes. A check valve insert is provided which includes a shutoff for the water flow when removing the check valve for service. The shutoff and removal of the check valve can be effected with a single tool.
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The present invention relates to novel substituted quinoline derivatives useful for the treatment of mycobacterial diseases, particularly those diseases caused by pathogenic mycobacteria such as Mycobacterium tuberculosis, M. bovis, M. avium and M. marinum.
BACKGROUND OF THE INVENTION
Mycobacterium tuberculosis is the causative agent of tuberculosis (TB), a serious and potentially fatal infection with a world-wide distribution. Estimates from the World Health Organization indicate that more than 8 million people contract TB each year, and 2 million people die from tuberculosis yearly. In the last decade, TB cases have grown 20% worldwide with the highest burden in the most impoverished communities. If these trends continue, TB incidence will increase by 41% in the next twenty years. Fifty years since the introduction of an effective chemotherapy, TB remains after AIDS, the leading infectious cause of adult mortality in the world. Complicating the TB epidemic is the rising tide of multi-drug-resistant strains, and the deadly symbiosis with HIV. People who are HIV-positive and infected with TB are 30 times more likely to develop active TB than people who are HIV-negative and TB is responsible for the death to one out of every three people with HIV/AIDS worldwide.
Existing approaches to treatment of tuberculosis all involve the combination of multiple agents. For example, the regimen recommended by the U.S. Public Health Service is a combination of isoniazid, rifampicin and pyrazinamide for two months, followed by isoniazid and rifampicin alone for a further four months. These drugs are continued for a further seven months in patients infected with HIV. For patients infected with multi-drug resistant strains of M. tuberculosis , agents such as ethambutol, streptomycin, kanamycin, amikacin, capreomycin, ethionamide, cycloserine, ciprofoxacin and ofloxacin are added to the combination therapies. There exists no single agent that is effective in the clinical treatment of tuberculosis, nor any combination of agents that offers the possibility of therapy of less than six months' duration.
There is a high medical need for new drugs that improve current treatment by enabling regimens that facilitate patient and provider compliance. Shorter regimens and those that require less supervision are the best way to achieve this. Most of the benefit from treatment comes in the first 2 months, during the intensive, or bactericidal, phase when four drugs are given together; the bacterial burden is greatly reduced, and patients become noninfectious. The 4- to 6-month continuation, or sterilizing, phase is required to eliminate persisting bacilli and to minimize the risk of relapse. A potent sterilizing drug that shortens treatment to 2 months or less would be extremely beneficial. Drugs that facilitate compliance by requiring less intensive supervision also are needed. Obviously, a compound that reduces both the total length of treatment and the frequency of drug administration would provide the greatest benefit.
Complicating the TB epidemic is the increasing incidence of multi-drug-resistant strains or MDR-TB. Up to four percent of all cases worldwide are considered MDR-TB—those resistant to the most effective drugs of the four-drug standard, isoniazid and rifampin. MDR-TB is lethal when untreated and can not be adequately treated through the standard therapy, so treatment requires up to 2 years of “second-line” drugs. These drugs are often toxic, expensive and marginally effective. In the absence of an effective therapy, infectious MDR-TB patients continue to spread the disease, producing new infections with MDR-TB strains. There is a high medical need for a new drug with a new mechanism of action, which is likely to demonstrate activity against MDR strains.
The purpose of the present invention is to provide novel compounds, in particular substituted quinoline derivatives, having the property of inhibiting growth of mycobacteria and therefore useful for the treatment of mycobacterial diseases, particularly those diseases caused by pathogenic mycobacteria such as Mycobacterium tuberculosis, M. bovis, M. avium, M. smegmatis and M. marinum.
Substituted quinolines were already disclosed in U.S. Pat. No. 5,965,572 (The United States of America) for treating antibiotic resistant infections and in WO 00/34265 to inhibit the growth of bacterial microorganisms. WO 2004/011436 describes quinoline derivatives as antimycobacterial agents.
SUMMARY OF THE INVENTION
The present invention relates to novel substituted quinoline derivatives according to Formula (I).
the pharmaceutically acceptable acid or base addition salts thereof, the quaternary amines thereof, the stereochemically isomeric forms thereof, the tautomeric forms thereof and the N-oxide forms thereof, wherein:
R 1 is hydrogen, halo, haloalkyl, cyano, hydroxy, Ar, Het, alkyl, alkyloxy, alkylthio, alkyloxyalkyl, alkylthioalkyl, Ar-alkyl or di(Ar)alkyl; p is an integer equal to 1, 2 or 3; s is an integer equal to zero, 1, 2, 3 or 4; R 2 is hydrogen; halo; alkyl; hydroxy; mercapto; alkyloxy optionally substituted with amino or mono or di(alkyl)amino or a radical of formula
wherein Z is CH 2 , CH—R 8 , O, S, N—R 8 and t is an integer equal to 1 or 2 and the dotted line represents an optional bond; alkyloxyalkyloxy; alkylthio; mono or di(alkyl)amino wherein alkyl may optionally be substituted with one or two substituents each independently be selected from alkyloxy or Ar or Het or morpholinyl or 2-oxopyrrolidinyl; Ar; Het or a radical of formula
wherein Z is CH 2 , CH—R 8 , O, S, N—R 8 ; t is an integer equal to 1 or 2; and the dotted line represents an optional bond;
R 3 is alkyl, Ar, Ar-alkyl, Het or Het-alkyl;
q is an integer equal to zero, 1, 2, 3 or 4;
R 4 and R 5 each independently are hydrogen, alkyl or benzyl; or
R 4 and R 5 together and including the N to which they are attached may form a radical selected from the group of pyrrolidinyl, 2H-pyrrolyl, 2-pyrrolinyl, 3-pyrrolinyl, pyrrolyl, imidazolidinyl, pyrazolidinyl, 2-imidazolinyl, 2-pyrazolinyl, imidazolyl, pyrazolyl, triazolyl, piperidinyl, pyridinyl, piperazinyl, imidazolidinyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, morpholinyl and thiomorpholinyl, each of said rings optionally being substituted with alkyl, halo, haloalkyl, hydroxy, alkyloxy, amino, mono or dialkylamino, alkylthio, alkyloxyalkyl, alkylthioalkyl and pyrimidinyl;
R 6 is hydrogen, halo, haloalkyl, hydroxy, Ar, alkyl, alkyloxy, alkylthio, alkyloxyalkyl, alkylthioalkyl, Ar-alkyl or di(Ar)alkyl; or
two vicinal R 6 radicals may be taken together to form together with the phenyl ring to which they are attached a naphthyl;
r is an integer equal to 1, 2, 3, 4 or 5; and
R 7 is hydrogen, alkyl, Ar or Het;
R 8 is hydrogen, alkyl, hydroxyl, aminocarbonyl, mono- or di(alkyl)aminocarbonyl, Ar, Het, alkyl substituted with one or two Het, alkyl substituted with one or two Ar, Het-C(═O)— or Ar—C(═O)—;
alkyl is a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms or is a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms; or is a a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms attached to a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms; wherein each carbon atom can be optionally substituted with halo, hydroxy, alkyloxy or oxo;
Ar is a homocycle selected from the group of phenyl, naphthyl, acenaphthyl, tetrahydronaphthyl, each optionally substituted with 1, 2 or 3 substituents, each substituent independently selected from the group of hydroxy, halo, cyano, nitro, amino, mono- or dialkylamino, alkyl, haloalkyl, alkyloxy, haloalkyloxy, carboxyl, alkyloxycarbonyl, alkylcarbonyl, aminocarbonyl, morpholinyl and mono- or dialkylaminocarbonyl;
Het is a monocyclic heterocycle selected from the group of N-phenoxypiperidinyl, pyrrolyl, pyrazolyl, imidazolyl, furanyl, thienyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, pyridinyl, pyrimidinyl, pyrazinyl and pyridazinyl; or a bicyclic heterocycle selected from the group of quinolinyl, isoquinolinyl, 1,2,3,4-tetrahydroisoquinolinyl, quinoxalinyl, indolyl, indazolyl, benzimidazolyl, benzoxazolyl, benzisoxazolyl, benzothiazolyl, benzisothiazolyl, benzofuranyl, benzothienyl, 2,3-dihydrobenzo[1,4]dioxinyl or benzo[1,3]dioxolyl; each monocyclic and bicyclic heterocycle may optionally be substituted on a carbon atom with 1, 2 or 3 substituents selected from the group of halo, hydroxy, alkyl or alkyloxy;
halo is a substituent selected from the group of fluoro, chloro, bromo and iodo and
haloalkyl is a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms or a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms, wherein one or more carbon atoms are substituted with one or more halo-atoms;
provided that when the radical
is placed in position 3 of the quinoline moiety; R 7 is placed in position 4 of the quinoline moiety and R 2 is placed in position 2 of the quinoline moiety and represents hydrogen, hydroxy, mercapto, alkyloxy, alkyloxyalkyloxy, alkylthio, mono or di(alkyl)amino or a radical of formula
wherein Y is CH 2 , O, S, NH or N-alkyl;
then s is 1, 2, 3 or 4.
DETAILED DESCRIPTION
In the framework of this application, alkyl is a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms; or is a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms; or is a a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms attached to a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms; wherein each carbon atom can be optionally substituted with halo, hydroxy, alkyloxy or oxo. Preferably, alkyl is methyl, ethyl or cyclohexylmethyl. More preferably alkyl is C 1-6 alkyl which as a group or part of a group encompasses the straight and branched chain saturated hydrocarbon radicals having from 1 to 6 carbon atoms such as, methyl, ethyl, butyl, pentyl, hexyl, 2-methylbutyl and the like.
In the framework of this application, Ar is a homocycle selected from the group of phenyl, naphthyl, acenaphthyl, tetrahydronaphthyl, each optionally substituted with 1, 2 or 3 substituents, each substituent independently selected from the group of hydroxy, halo, cyano, nitro, amino, mono- or dialkylamino, alkyl, haloalkyl, alkyloxy, haloalkyloxy, carboxyl, alkyloxycarbonyl, aminocarbonyl, morpholinyl and mono- or dialkylaminocarbonyl. Preferably, Ar is naphthyl or phenyl, each optionally substituted with 1 or 2 halo substituents.
In the framework of this application, Het is a monocyclic heterocycle selected from the group of N-phenoxypiperidinyl, pyrrolyl, pyrazolyl, imidazolyl, furanyl, thienyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, pyridinyl, pyrimidinyl, pyrazinyl and pyridazinyl; or a bicyclic heterocycle selected from the group of quinolinyl, isoquinolinyl, 1,2,3,4-tetrahydroisoquinolinyl, quinoxalinyl, indolyl, indazolyl, benzimidazolyl, benzoxazolyl, benzisoxazolyl, benzothiazolyl, benzisothiazolyl, benzofuranyl, benzothienyl, 2,3-dihydrobenzo[1,4]dioxinyl or benzo[1,3]dioxolyl; each monocyclic and bicyclic heterocycle may optionally be substituted on a carbon atom with 1, 2 or 3 substituents selected from the group of halo, hydroxy, alkyl or alkyloxy. Preferably Het is thienyl.
In the framework of this application, halo is a substituent selected from the group of fluoro, chloro, bromo and iodo and haloalkyl is a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms or a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms, wherein one or more carbon atoms are substituted with one or more halo-atoms. Preferably, halo is bromo, fluoro or chloro and preferably, haloalkyl is trifluoromethyl.
In the framework of this application, the quinoline moiety is numbered as follows
The
radical, R 2 , R 7 and R 1 may be placed on any available position of the quinoline moiety.
Whenever used hereinafter, the term “compounds of formula (I)” or any subgroup thereof, is meant to also include their N-oxide forms, their salts, their quaternary amines, their tautomeric forms and their stereochemically isomeric forms. Of special interest are those compounds of formula (I) which are stereochemically pure.
An interesting embodiment of the present invention relates to those compounds of formula (I), the pharmaceutically acceptable acid or base addition salts thereof, the stereochemically isomeric forms thereof, the tautomeric forms thereof and the N-oxide forms thereof, wherein
R 1 is hydrogen, halo, haloalkyl, cyano, hydroxy, Ar, Het, alkyl, alkyloxy, alkylthio, alkyloxyalkyl, alkylthioalkyl, Ar-alkyl or di(Ar)alkyl; p is an integer equal to 1, 2 or 3; s is an integer equal to zero, 1, 2, 3 or 4; R 2 is hydrogen; halo; alkyl; hydroxy; mercapto; alkyloxy optionally substituted with amino or mono or di(alkyl)amino or a radical of formula
wherein Z is CH 2 , CH—R 8 , O, S, N—R 8 and t is an integer equal to 1 or 2 and the dotted line represents an optional bond; alkyloxyalkyloxy; alkylthio; mono or di(alkyl)amino wherein alkyl may optionally be substituted with one or two substituents each independently be selected from alkyloxy or Ar or Het or morpholinyl or 2-oxopyrrolidinyl; Het or a radical of formula
wherein Z is CH 2 , CH—R 8 , O, S, N—R 8 ; t is an integer equal to 1 or 2; and the dotted line represents an optional bond;
R 3 is alkyl, Ar, Ar-alkyl, Het or Het-alkyl;
q is an integer equal to zero, 1, 2, 3 or 4;
R 4 and R 5 each independently are hydrogen, alkyl or benzyl; or
R 4 and R 5 together and including the N to which they are attached may form a radical selected from the group of pyrrolidinyl, 2H-pyrrolyl, 2-pyrrolinyl, 3-pyrrolinyl, pyrrolyl, imidazolidinyl, pyrazolidinyl, 2-imidazolinyl, 2-pyrazolinyl, imidazolyl, pyrazolyl, triazolyl, piperidinyl, pyridinyl, piperazinyl, imidazolidinyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, morpholinyl and thiomorpholinyl, optionally substituted with alkyl, halo, haloalkyl, hydroxy, alkyloxy, amino, mono- or dialkylamino, alkylthio, alkyloxyalkyl, alkylthioalkyl and pyrimidinyl;
R 6 is hydrogen, halo, haloalkyl, hydroxy, Ar, alkyl, alkyloxy, alkylthio, alkyloxyalkyl, alkylthioalkyl, Ar-alkyl or di(Ar)alkyl; or
two vicinal R 6 radicals may be taken together to form together with the phenyl ring to which they are attached a naphthyl;
r is an integer equal to 1, 2, 3, 4 or 5; and
R 7 is hydrogen, alkyl, Ar or Het;
R 8 is hydrogen, alkyl, aminocarbonyl, mono- or di(alkyl)aminocarbonyl, Ar, Het, alkyl substituted with one or two Het, alkyl substituted with one or two Ar, Het-C(═O)—
alkyl is a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms; or is a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms or is a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms attached to a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms; wherein each carbon atom can be optionally substituted with halo, hydroxy, alkyloxy or oxo;
Ar is a homocycle selected from the group of phenyl, naphthyl, acenaphthyl, tetrahydronaphthyl, each optionally substituted with 1, 2 or 3 substituents, each substituent independently selected from the group of hydroxy, halo, cyano, nitro, amino, mono- or dialkylamino, alkyl, haloalkyl, alkyloxy, haloalkyloxy, carboxyl, alkyloxycarbonyl, alkylcarbonyl, aminocarbonyl, morpholinyl and mono- or dialkylaminocarbonyl;
Het is a monocyclic heterocycle selected from the group of N-phenoxypiperidinyl, pyrrolyl, pyrazolyl, imidazolyl, furanyl, thienyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, pyridinyl, pyrimidinyl, pyrazinyl and pyridazinyl; or a bicyclic heterocycle selected from the group of quinolinyl, quinoxalinyl, indolyl, indazolyl, benzimidazolyl, benzoxazolyl, benzisoxazolyl, benzothiazolyl, benzisothiazolyl, benzofuranyl, benzothienyl, 2,3-dihydrobenzo[1,4]dioxinyl or benzo[1,3]dioxolyl; each monocyclic and bicyclic heterocycle may optionally be substituted on a carbon atom with 1, 2 or 3 substituents selected from the group of halo, hydroxy, alkyl or alkyloxy;
halo is a substituent selected from the group of fluoro, chloro, bromo and iodo and
haloalkyl is a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms or a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms, wherein one or more carbon atoms are substituted with one or more halo-atoms,
provided that when the radical
is placed in position 3 of the quinoline moiety; R 7 is placed in position 4 of the quinoline moiety and R 2 is placed in position 2 of the quinoline moiety and represents hydrogen, hydroxy, mercapto, alkyloxy, alkyloxyalkyloxy, alkylthio, mono or di(alkyl)amino or a radical of formula
wherein Y is CH 2 , O, S, NH or N-alkyl;
then s is 1, 2, 3 or 4.
Preferably, the invention relates to compounds of formula (I) or any subgroup thereof, as described hereinabove, provided that when the radical
is placed in position 3 of the quinoline moiety; R 7 is placed in position 4 of the quinoline moiety and R 2 is placed in position 2 of the quinoline moiety, then s is 1, 2, 3 or 4.
Preferably, the invention relates to compounds of formula (I) or any subgroup thereof, as described hereinabove, provided that when the radical
is placed in position 3 of the quinoline moiety; then s is 1, 2, 3 or 4.
Preferably, the invention relates to compounds of formula (I) or any subgroup thereof, as described hereinabove, provided that the radical
is not placed in position 3 of the quinoline moiety.
Preferably, the invention relates to compounds of formula (I) or any subgroup thereof, as described hereinabove, wherein the compounds have the following formula
the pharmaceutically acceptable acid or base addition salts thereof the quaternary amines thereof, the stereochemically isomeric forms thereof, the tautomeric forms thereof and the N-oxide forms thereof.
Preferably, the invention relates to compounds of formula (I-a-1) or any subgroup thereof, as described hereinabove
Preferably, the invention relates to compounds of formula (I-a-1-1) or any subgroup thereof, as described hereinabove
the pharmaceutically acceptable acid or base addition salts thereof, the quaternary amines thereof, the stereochemically isomeric forms thereof, the tautomeric forms thereof and the N-oxide forms thereof.
Preferably, the invention relates to compounds of formula (I) or any subgroup thereof, as described hereinabove, wherein the compounds have the following formula
the pharmaceutically acceptable acid or base addition salts thereof, the quaternary amines thereof, the stereochemically isomeric forms thereof, the tautomeric forms thereof and the N-oxide forms thereof.
Preferably, the invention relates to compounds of formula (I) or any subgroup thereof, as described hereinabove, wherein the compounds have the following formula
the pharmaceutically acceptable acid or base addition salts thereof, the quaternary amines thereof, the stereochemically isomeric forms thereof, the tautomeric forms thereof and the N-oxide forms thereof.
Preferably, the invention relates to compounds of Formula (I) or any subgroup thereof, as described hereinabove, wherein:
R 1 is hydrogen, halo, cyano, Ar, Het, alkyl, and alkyloxy; p is an integer equal to 1, 2, 3 or 4; in particular 1 or 2; more in particular 1; s is an integer of 0 or 1; R 2 is hydrogen; alkyl; hydroxy; alkyloxy optionally substituted with amino or mono or di(alkyl)amino or a radical of formula
wherein Z is CH 2 , CH—R 10 , O, S, N—R 10 and t is an integer equal to 1 or 2 and the dotted line represents an optional bond; alkyloxyalkyloxy; alkylthio, mono or di(alkyl)amino; Ar; Het or a radical of formula
wherein Z is CH 2 , CH—R 10 , O, S, N—R 10 ; t is an integer equal to 1 or 2; and the dotted line represents all optional bond; in particular R 2 is hydrogen, hydroxy, alkyloxy, alkyloxyalkyloxy, alkylthio or a radical of formula
wherein Y is O; more in particular R 2 is hydrogen, halo or alkyl, even more in particular R 2 is hydrogen or alkyl;
R 3 is alkyl, Ar, Ar-alkyl or Het; in particular Ar;
q is an integer equal to zero, 1, 2, or 3; in particular 1;
R 4 and R 5 each independently are hydrogen, alkyl or benzyl; or
R 4 and R 5 together and including the N to which they are attached may form a radical selected from the group of pyrrolidinyl, imidazolyl, triazolyl, piperidinyl, piperazinyl, pyrazinyl, morpholinyl and thiomorpholinyl, optionally substituted with alkyl and pyrimidinyl; in particular R 4 and R 5 are alkyl; more in particular R 4 and R 5 are C 1-6 alkyl, preferably methyl;
R 6 is hydrogen, halo or alkyl; or
two vicinal R 6 radicals may be taken together to form together with the phenyl ring to which they are attached a naphthyl;
r is an integer equal to 1; and
R 7 is hydrogen or Ar; in particular hydrogen or phenyl;
alkyl is a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms; or is a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms; or is a a cyclic saturated hydrocarbon radical having from 3 to 6 carbon atoms attached to a straight or branched saturated hydrocarbon radical having from 1 to 6 carbon atoms; wherein each carbon atom can be optionally substituted with halo or hydroxy;
Ar is a homocycle selected from the group of phenyl, naphthyl, acenaphthyl, tetrahydronaphthyl, each optionally substituted with 1, 2 or 3 substituents, each substituent independently selected from the group of halo, haloalkyl, cyano, alkyloxy and morpholinyl;
Het is a monocyclic heterocycle selected from the group of N-phenoxypiperidinyl, furanyl, thienyl, pyridinyl, pyrimidinyl; or a bicyclic heterocycle selected from the group of benzothienyl, 2,3-dihydrobenzo[1,4]dioxinyl or benzo[1,3]-dioxolyl; each monocyclic and bicyclic heterocycle may optionally be substituted on a carbon atom with 1, 2 or 3 alkyl substituents; and
halo is a substituent selected from the group of fluoro, chloro and bromo.
For compounds according to Formula (I) or any subgroup thereof, as described hereinabove, preferably, R 1 is hydrogen, halo, Ar, Het, alkyl or alkyloxy. More preferably, R 1 is hydrogen, halo, Ar, alkyl or alkyloxy; even more preferably R 1 is halo. Most preferably, R 1 is bromo or chloro.
For compounds according to Formula (I) or any subgroup thereof as described hereinabove, preferably, p is equal to 1 or 2. More preferably, p is equal to 1.
For compounds according to Formula (I) or any subgroup thereof as described hereinabove, preferably, R 2 is hydrogen; halo, alkyl; hydroxy; mercapto; alkyloxy optionally substituted with amino or mono or di(alkyl)amino or a radical of formula
wherein Z is CH 2 , CH—R 8 , O, S, N—R 8 and t is an integer equal to 1 or 2 and the doted line represents an optional bond; alkyloxyalkyloxy; alkylthio; mono or di(alkyl)amino wherein alkyl may optionally be substituted with one or two substituents each independently be selected from alkyloxy or Ar or Het or morpholinyl or 2-oxopyrrolidinyl; Het or a radical of formula
wherein Z is CH 2 , CH—R 8 , O, S, N—R 8 ; t is an integer equal to 1 or 2; and the dotted line represents an optional bond.
Also, an interesting group of compounds of Formula (I) or any subgroup thereof, as described hereinabove, are those compounds wherein R 2 is hydrogen; alkyl; alkyloxy optionally substituted with amino or mono or di(alkyl)amino or a radical of formula
wherein Z is CH 2 , CH—R 10 , O, S, N—R 10 and t is an integer equal to 1 or 2 and the dotted line represents an optional bond; mono or di(alkyl)amino; Ar; Het or a radical of formula
wherein Z is CH 2 , CH—R 10 , O, S, N—R 10 ; t is an integer equal to 1 or 2; and the dotted line represents an optional bond. More preferably, R 2 is hydrogen, halo, alkyl, alkyloxy or alkylthio. Even more preferably, R 2 is hydrogen, halo or C 1-6 alkyl (e.g. ethyl). Most preferably, R 2 is hydrogen or C 1-6 alkyl (e.g. ethyl).
For compounds according to Formula (I) or any subgroup thereof, as described hereinabove, preferably, R 3 is naphthyl, phenyl or Het, each optionally substituted with 1 or 2 substituents, that substituent preferably being a halo or haloalkyl, most preferably being a halo. More preferably, R 3 is optionally substituted naphthyl or optionally substituted phenyl. Most preferably, R 3 is naphthyl or optionally substituted phenyl (e.g. 3-halophenyl or 3,5-dihalophenyl).
For compounds according to Formula (I) or any subgroup thereof, as described hereinabove, q is equal to zero, 1 or 2. More preferably, q is equal to 1.
For compounds according to Formula (I) or any subgroup thereof, as described hereinabove, R 4 and R 5 each independently are hydrogen or alkyl, more preferably hydrogen, or C 1-6 alkyl, e.g. methyl or ethyl, most preferably methyl.
For compounds according to Formula (I) or any subgroup thereof, as described hereinabove, R 4 and R 5 together and including the N to which they are attached form a radical selected from the group of imidazolyl, triazolyl, piperidinyl, piperazinyl and thiomorpholinyl, optionally substituted with alkyl, halo, haloalkyl, hydroxy, alkyloxy, alkylthio, alkyloxyalkyl or alkylthioalkyl, preferably substituted with alkyl, most preferably substituted with methyl or ethyl.
For compounds according to Formula (I) or any subgroup thereof, as described hereinabove, R 6 is hydrogen, halo, haloalkyl, hydroxy, Ar, alkyl, alkyloxy, alkylthio, alkyloxyalkyl, alkylthioalkyl, Ar-alkyl or di(Ar)alkyl. More preferably, R 6 is hydrogen, alkyl or halo. Most preferably, R 6 is hydrogen. Preferably r is 1 or 2. More preferably, r is 1.
For compounds according to Formula (I) or any subgroup thereof, as described hereinabove, preferably, R 7 is hydrogen, methyl or Ar, more preferably hydrogen or Ar, e.g. phenyl.
For compounds according to Formula (I) or any subgroup thereof, as described hereinabove, preferably, R 8 is hydrogen, alkyl, aminocarbonyl, mono- or di(alkyl)aminocarbonyl, Ar, Het, alkyl substituted with one or two Het, alkyl substituted with one or two Ar, Het-C(═O)—.
For compounds according to Formula (I) or any subgroup thereof, as described hereinabove, preferably, s is an integer equal to 0 or 1.
An interesting group of compounds of Formula (I) or any subgroup thereof, as defined hereinabove, are those compounds wherein
R 1 is halo, in particular bromo; p is equal to 1; s is equal to 0 or 1; R 2 is hydrogen, halo or alkyl; in particular hydrogen or alkyl; R 3 is optionally substituted phenyl or optionally substituted naphthyl, in particular 3-halophenyl, 3,5-dihalophenyl or naphthyl; R 4 and R 5 are C 1-6 alkyl, in particular methyl. R 6 is hydrogen and r is 1. R 7 is hydrogen or Ar, in particular hydrogen or phenyl.
Interesting intermediates of the present invention are intermediates of formula (II)
wherein R 1 , R 2 , R 6 , R 7 , p and s are as defined hereinabove,
in particular interesting intermediates are intermediates of formula (II-a)
wherein R 1 , R 2 , R 6 , R 7 , p and s are as defined hereinabove.
The pharmaceutically acceptable acid addition salts are defined to comprise the therapeutically active non-toxic acid addition salt forms which the compounds according to Formula (I) or any subgroup thereof, as described hereinabove, are able to form. Said acid addition salts can be obtained by treating the base form of the compounds according to Formula (I) or any subgroup thereof, as described hereinabove, with appropriate acids, for example inorganic acids, for example hydrohalic acid, in particular hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid and phosphoric acid; organic acids, for example acetic acid, hydroxyacetic acid, propanoic acid, lactic acid, pyruvic acid, oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, malic acid, tartaric acid, citric acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, cyclamic acid, salicyclic acid, p-aminosalicylic acid and pamoic acid.
The compounds according to Formula (I) or any subgroup thereof, as described hereinabove, containing acidic protons may also be converted into their therapeutically active non-toxic base addition salt forms by treatment with appropriate organic and inorganic bases. Appropriate base salts forms comprise, for example, the ammonium salts, the alkaline and earth alkaline metal salts, in particular lithium, sodium, potassium, magnesium and calcium salts, salts with organic bases, e.g. the benzathine, N-methyl-D-glucamine, hybramine salts, and salts with amino acids, for example arginine and lysine.
Conversely, said acid or base addition salt forms can be converted into the free forms by treatment with an appropriate base or acid.
The term addition salt as used in the framework of this application also comprises the solvates which the compounds according to Formula (I) or any subgroup thereof, as described hereinabove, as well as the salts thereof, are able to form. Such solvates are, for example, hydrates and alcoholates.
The term “quaternary amine” as used hereinbefore defines the quaternary ammonium salts which the compounds of formula (I) or any subgroup thereof, as described hereinabove, are able to form by reaction between a basic nitrogen of a compound of formula (I) or any subgroup thereof, as described hereinabove, and an appropriate quaternizing agent, such as, for example, an optionally substituted alkylhalide, arylhalide or arylalkylhalide, e.g. methyliodide or benzyliodide. Other reactants with good leaving groups may also be used, such as alkyl trifluoromethanesulfonates, alkyl methanesulfonates, and alkyl p-toluenesulfonates. A quaternary amine has a positively charged nitrogen. Pharmaceutically acceptable counterions include chloro, bromo, iodo, trifluoroacetate and acetate. The counterion of choice can be introduced using ion exchange resins.
The term “stereochemically isomeric forms” as used herein defines all possible isomeric forms which the compounds of Formula (I) or any subgroup thereof, as described hereinabove, may possess. Unless otherwise mentioned or indicated, the chemical designation of compounds denotes the mixture of all possible stereochemically isomeric forms, said mixtures containing all diastereomers and enantiomers of the basic molecular structure. More in particular, stereogenic centers may have the R- or S-configuration; substituents on bivalent cyclic (partially) saturated radicals may have either the cis- or trans-configuration. Stereochemically isomeric forms of the compounds of Formula (I) or any subgroup thereof, as described hereinabove, are obviously intended to be embraced within the scope of this invention.
Following CAS-nomenclature conventions, when two stereogenic centers of known absolute configuration are present in a molecule, an R or S descriptor is assigned (based on Cahn-Ingold-Prelog sequence rule) to the lowest-numbered chiral center, the reference center. The configuration of the second stereogenic center is indicated using relative descriptors [R*,R*] or [R*,S*], where R* is always specified as the reference center and [R*,R*] indicates centers with the same chirality and [R*,S*] indicates centers of unlike chirality. For example, if the lowest-numbered chiral center in the molecule has an S configuration and the second center is R, the stereo descriptor would be specified as S—[R*,S*]. If “α” and “β” are used: the position of the highest priority substituent on the asymmetric carbon atom in the ring system having the lowest ring number, is arbitrarily always in the “β” position of the mean plane determined by the ring system. The position of the highest priority substituent on the other asymmetric carbon atom in the ring system relative to the position of the highest priority substituent on the reference atom is denominated “β”, if it is on the same side of the mean plane determined by the ring system, or “β”, if it is on the other side of the mean plane determined by the ring system.
Compounds of Formula (I) or any subgroup thereof as described hereinabove, and some of the intermediate compounds invariably have at least one stereogenic centers in their structure which may lead to at least 2 stereochemically different structures.
The compounds of Formula (I) or any subgroup thereof as described hereinabove, as prepared in the processes described below may be synthesized in the form of racemic mixtures of enantiomers which can be separated from one another following art-known resolution procedures. The racemic compounds of Formula (I) or any subgroup thereof, as described hereinabove, may be converted into the corresponding diastereomeric salt forms by reaction with a suitable chiral acid. Said diastereomeric salt forms are subsequently separated, for example, by selective or fractional crystallization and the enantiomers are liberated therefrom by alkali. An alternative manner of separating the enantiomeric forms of the compounds of Formula (I) or any subgroup thereof, as described hereinabove, involves liquid chromatography using a chiral stationary phase. Said pure stereochemically isomeric forms may also be derived from the corresponding pure stereochemically isomeric forms of the appropriate starting materials, provided that the reaction occurs stereospecifically. Preferably if a specific stereoisomer is desired, said compound will be synthesized by stereospecific methods of preparation. These methods will advantageously employ enantiomerically pure starting materials.
The tautomeric forms of the compounds of Formula (I) or any subgroup thereof, as described hereinabove, are meant to comprise those compounds of Formula (I) or any subgroup thereof, as described hereinabove, wherein e.g. an enol group is converted into a keto group (keto-enol tautomerism).
The N-oxide forms of the present compounds are meant to comprise the compounds of formula (I) or any subgroup thereof, as described hereinabove, wherein one or several tertiary nitrogen atoms are oxidized to the so-called N-oxide.
The invention also comprises derivative compounds (usually called “pro-drugs”) of the pharmacologically-active compounds according to the invention, which are degraded in vivo to yield the compounds according to the invention. Pro-drugs are usually (but not always) of lower potency at the target receptor than the compounds to which they are degraded. Pro-drugs are particularly useful when the desired compound has chemical or physical properties that make its administration difficult or inefficient. For example, the desired compound may be only poorly soluble, it may be poorly transported across the mucosal epithelium, or it may have an undesirably short plasma half-life. Further discussion on pro-drugs may be found in Stella, V. J. et al., “Prodrugs”, Drug Delivery Systems, 1985, pp. 112-176, and Drugs, 1985, 29, pp. 455-473.
Pro-drugs forms of the pharmacologically-active compounds according to the invention will generally be compounds according to Formula (I) or any subgroup thereof, as described hereinabove, the pharmaceutically acceptable acid or base addition salts thereof, the stereochemically isomeric forms thereof, the tautomeric forms thereof and the N-oxide forms thereof, having an acid group which is esterified or amidated. Included in such esterified acid groups are groups of the formula —COOR x , where R x is a C 1-6 alkyl, phenyl, benzyl or one of the following groups:
Amidated groups include groups of the formula —CONR y R z , wherein R y is H, C 1-6 alkyl, phenyl or benzyl and R z is —OH, H, C 1-6 alkyl, phenyl or benzyl.
Compounds according to the invention having an amino group may be derivatised with a ketone or an aldehyde such as formaldehyde to form a Mannich base. This base will hydrolyze with first order kinetics in aqueous solution.
The compounds according to the invention have surprisingly been shown to be suitable for the treatment of mycobacterial diseases, particularly those diseases caused by pathogenic mycobacteria, including drug resistant and multi drug resistant mycobacteria, such as Mycobacterium tuberculosis, M. bovis, M. avium, M. smegmatis and M. marinum . The present invention thus also relates to compounds of Formula (I) or any subgroup thereof, as described hereinabove, as defined hereinabove, the pharmaceutically acceptable acid or base addition salts thereof, the stereochemically isomeric forms thereof, the tautomeric forms thereof and the N-oxide forms thereof, for use as a medicine.
The invention also relates to a composition comprising a pharmaceutically acceptable carrier and, as active ingredient, a therapeutically effective amount of a compound according to the invention. The compounds according to the invention may be formulated into various pharmaceutical forms for administration purposes. As appropriate compositions there may be cited all compositions usually employed for systemically administering drugs. To prepare the pharmaceutical compositions of this invention, an effective amount of the particular compound, optionally in addition salt form, as the active ingredient is combined in intimate admixture with a pharmaceutically acceptable carrier, which carrier may take a wide variety of forms depending on the form of preparation desired for administration. These pharmaceutical compositions are desirable in unitary dosage form suitable, in particular, for administration orally or by parenteral injection. For example, in preparing the compositions in oral dosage form, any of the usual pharmaceutical media may be employed such as, for example, water, glycols, oils, alcohols and the like in the case of oral liquid preparations such as suspensions, syrups, elixirs, emulsions and solutions; or solid carriers such as starches, sugars, kaolin, diluents, lubricants, binders, disintegrating agents and the like in the case of powders, pills, capsules and tablets. Because of their ease in administration, tablets and capsules represent the most advantageous oral dosage unit forms in which case solid pharmaceutical carriers are obviously employed. For parenteral compositions, the carrier will usually comprise sterile water, at least in large part, though other ingredients, for example, to aid solubility, may be included. Injectable solutions, for example, may be prepared in which the carrier comprises saline solution, glucose solution or a mixture of saline and glucose solution. Injectable suspensions may also be prepared in which case appropriate liquid carriers, suspending agents and the like may be employed. Also included are solid form preparations which are intended to be converted, shortly before use, to liquid form preparations.
Depending on the mode of administration, the pharmaceutical composition will preferably comprise from 0.05 to 99% by weight, more preferably from 0.1 to 70% by weight of the active ingredient of formula (I) or any subgroup thereof, as described hereinabove, and, from 1 to 99.95% by weight, more preferably from 30 to 99.9 weight % of a pharmaceutically acceptable carrier, all percentages being based on the total composition.
The pharmaceutical composition may additionally contain various other ingredients known in the art, for example, a lubricant, stabilising agent, buffering agent, emulsifying agent, viscosity-regulating agent, surfactant, preservative, flavouring or colorant.
It is especially advantageous to formulate the aforementioned pharmaceutical compositions in unit dosage form for ease of administration and uniformity of dosage. Unit dosage form as used herein refers to physically discrete units suitable as unitary dosages, each unit containing a predetermined quantity of active ingredient calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. Examples of such unit dosage forms are tablets (including scored or coated tablets), capsules, pills, powder packets, wafers, suppositories, injectable solutions or suspensions and the like, and segregated multiples thereof. The daily dosage of the compound according to the invention will, of course, vary with the compound employed, the mode of administration, the treatment desired and the mycobacterial disease indicated. However, in general, satisfactory results will be obtained when the compound according to the invention is administered at a daily dosage not exceeding 1 gram, e.g. in the range from 10 to 50 mg/kg body weight.
Further, the present invention also relates to the use of a compound of Formula (I) or any subgroup thereof, as described hereinabove, the pharmaceutically acceptable acid or base addition salts thereof, the stereochemically isomeric forms thereof, the tautomeric forms thereof and the N-oxide forms thereof, as well as any of the aforementioned pharmaceutical compositions thereof for the manufacture of a medicament for the prevention or the treatment of mycobacterial diseases.
Accordingly, in another aspect, the invention provides a method of treating a patient suffering from, or at risk of, a mycobacterial disease, which comprises administering to the patient a therapeutically effective amount of a compound or pharmaceutical composition according to the invention.
The compounds of the present invention may also be combined with one or more other antimycobacterial agents.
Therefore, the present invention also relates to a combination of (a) a compound of formula (I) or any subgroup thereof, as described hereinabove, and (b) one or more other antimycobacterial agents.
The present invention also relates to a combination of (a) a compound of formula (I) or any subgroup thereof, as described hereinabove, and (b) one or more other antimycobacterial agents for use as a medicine.
A pharmaceutical composition comprising a pharmaceutically acceptable carrier and, as active ingredient, a therapeutically effective amount of (a) a compound of formula (I) or any subgroup thereof, as described hereinabove, and (b) one or more other antimycobacterial agents is also comprised by the present invention.
The other Mycobacterial agents which may be combined with the compounds of formula (I) or any subgroup thereof, as described hereinabove, are for example rifampicin (=rifampin); isoniazid; pyrazinamide; amikacin; ethionamide; moxifloxacin; ethanbutol; streptomycin; para-aminosalicylic acid; cycloserine; capreomycin; kanamycin; thioacetazone; PA-824; quinolones/fluoroquinolones such as for example ofloxacin, ciprofloxacin, sparfloxacin; macrolides such as for example clarithromycin, clofazimine, amoxycillin with clavulanic acid; rifamycins; rifabutin; rifapentine.
Preferably, the present compounds of formula (I) or any subgroup thereof, as described hereinabove, are combined with rifapentin and moxifloxacin.
General Preparation
The compounds according to the invention can generally be prepared by a succession of steps, each of which is known to the skilled person.
Compounds of formula (I) can be prepared by reacting an intermediate of formula (II) with an intermediate of formula (III) in the presence of a suitable coupling agent, such as for example n-butyl lithium, secBuLi, and in the presence of a suitable solvent, such as for example tetrahydrofuran, and optionally in the presence of a suitable base, such as for example 2,2,6,6-tetramethylpiperidine, NH(CH 2 CH 2 CH 3 ) 2 , N,N-diisopropylamine or trimethylethylenediamine.
In the above reaction, the obtained compound of formula (I) can be isolated, and, if necessary, purified according to methodologies generally known in the art such as, for example, extraction, crystallization, distillation, trituration and chromatography. In case the compound of formula (I) crystallizes out, it can be isolated by filtration. Otherwise, crystallization can be caused by the addition of an appropriate solvent, such as for example water; acetonitrile; an alcohol, such as for example methanol, ethanol; and combinations of said solvents. Alternatively, the reaction mixture can also be evaporated to dryness, followed by purification of the residue by chromatography (e.g. reverse phase HPLC, flash chromatography and the like). The reaction mixture can also be purified by chromatography without previously evaporating the solvent. The compound of formula (I) can also be isolated by evaporation of the solvent followed by recrystallisation in an appropriate solvent, such as for example water; acetonitrile; an alcohol, such as for example methanol; and combinations of said solvents.
The person skilled in the art will recognise which method should be used, which solvent is the most appropriate to use or it belongs to routine experimentation to find the most suitable isolation method.
The compounds of formula (I) may further be prepared by converting compounds of formula (I) into each other according to art-known group transformation reactions.
The compounds of formula (I) may be converted to the corresponding N-oxide forms following art-known procedures for converting a trivalent nitrogen into its N-oxide form. Said N-oxidation reaction may generally be carried out by reacting the starting material of formula (I) with an appropriate organic or inorganic peroxide. Appropriate inorganic peroxides comprise, for example, hydrogen peroxide, alkali metal or earth alkaline metal peroxides, e.g. sodium peroxide, potassium peroxide; appropriate organic peroxides may comprise peroxy acids such as, for example, benzenecarboperoxoic acid or halo substituted benzenecarboperoxoic acid, e.g. 3-chlorobenzenecarboperoxoic acid, peroxoalkanoic acids, e.g. peroxoacetic acid, alkylhydroperoxides, e.g. t.butyl hydro-peroxide. Suitable solvents are, for example, water, lower alcohols, e.g. ethanol and the like, hydrocarbons, e.g. toluene, ketones, e.g. 2-butanone, halogenated hydrocarbons, e.g. dichloromethane, and mixtures of such solvents.
Compounds of formula (I) wherein R 1 represents halo, can be converted into a compound of formula (I) wherein R 1 represents Het, e.g. pyridyl, by reaction with
in the presence of a suitable catalyst, such as for example Pd(PPh 3 ) 4 , a suitable solvent, such as for example dimethylether or an alcohol, e.g. methanol and the like, and a suitable base, such as for example disodium carbonate or dipotassium carbonate.
Compounds of formula (I) wherein R 1 represents halo, can also be converted into a compound of formula (I) wherein R 1 represents methyl, by reaction with Sn(CH 3 ) 4 in the presence of a suitable catalyst, such as for example Pd(PPh 3 ) 4 , a suitable solvent, such as for example toluene.
Some of the compounds of formula (I) and some of the intermediates in the present invention may consist of a mixture of stereochemically isomeric forms. Pure stereochemically isomeric forms of said compounds and said intermediates can be obtained by the application of art-known procedures. For example, diastereoisomers can be separated by physical methods such as selective crystallization or chromatographic techniques, e.g. counter current distribution, liquid chromatography and the like methods. Enantiomers can be obtained from racemic mixtures by first converting said racemic mixtures with suitable resolving agents such as, for example, chiral acids, to mixtures of diastereomeric salts or compounds; then physically separating said mixtures of diastereomeric salts or compounds by, for example, selective crystallization or chromatographic techniques, e.g. liquid chromatography and the like methods; and finally converting said separated diastereomeric salts or compounds into the corresponding enantiomers. Pure stereochemically isomeric forms may also be obtained from the pure stereochemically isomeric forms of the appropriate intermediates and starting materials, provided that the intervening reactions occur stereospecifically.
An alternative manner of separating the enantiomeric forms of the compounds of formula (I) and intermediates involves liquid chromatography, in particular liquid chromatography using a chiral stationary phase.
It is to be understood that in the above or the following preparations, the reaction products may be isolated from the reaction medium and, if necessary, further purified according to methodologies generally known in the art such as, for example, extraction, crystallization, distillation, trituration and chromatography.
Some of the intermediates and starting materials are known compounds and may be commercially available or may be prepared according to art-known procedures.
Intermediates of formula (II) wherein the
radical is placed in position 2 of the quinoline ring, s is an integer equal to 1 and position 4 of the quinoline ring is unsubstituted, said intermediates being represented by formula (II-a), can be prepared by reacting an intermediate of formula (IV) with phenyloxybenzene in the presence of ethyl acetate.
Intermediates of formula (IV) wherein R 2 and R 7 represent hydrogen, said intermediates being represented by formula (IV-a), can be prepared by reacting an intermediate of formula (V) with an intermediate of formula (VI) in the presence of a suitable base, such as for example sodium hydroxide.
Intermediates of formula (II) wherein the
radical is placed in position 2 of the quinoline ring and s is 0, said intermediates being represented by formula (II-b), can be prepared by reacting an intermediate of formula (VII) wherein W 1 represents a suitable leaving group, such as for example halo, e.g. chloro and the like, with an intermediate of formula (VIII) wherein W 2 represents a suitable leaving group, such as for example halo, e.g. chloro, bromo and the like, in the presence of Zn, chlorotrimethylsilane, 1,2-dibromoethane and Pd(PPh 3 ) 4 and a suitable solvent such as for example tetrahydrofuran.
Intermediates of formula (VII) wherein W 1 represents chloro, said intermediates being represented by formula (VII-a), can be prepared by reacting an intermediate of formula (IX) with POCl 3 .
Intermediates of formula (IX) can be prepared by reacting an intermediate of formula (X) with 4-methylbenzenesulfonyl chloride in the presence of a suitable solvent, such as for example methylene chloride, and a suitable base, such as for example dipotassium carbonate.
Intermediates of formula (X) can be prepared by reacting an intermediate of formula (XI) with a suitable oxidizing agent, such as for example 3-chlorobenzenecarboperoxoic acid, in the presence of a suitable solvent, such as for example methylene chloride.
Intermediates of formula (II) wherein s is 0, said intermediates being represented by formula (I-c), can be prepared by reacting an intermediate of formula (XII) with Et 3 SiH in the presence of a suitable acid, such as for example trifluoroacetic acid, and a suitable solvent, such as for example methylene chloride.
Intermediates of formula (XII) can be prepared by reacting an intermediate of formula (XIII) wherein W 3 represents a suitable leaving group, such as for example halo, e.g. chloro or bromo and the like, with an intermediate of formula (XIV) in the presence of a suitable coupling agent, such as for example n-butyl lithium, secBuLi, and in the presence of a suitable solvent, such as for example tetrahydrofuran, and optionally in the presence of a suitable base, such as for example 2,2,6,6-tetramethylpiperidine, NH(CH 2 CH 2 CH 3 ) 2 , N,N-diisopropylamine or trimethylethylenediamine.
Intermediates of formula (XII) wherein radical is placed in position 8 of the quinoline ring, R 2 is placed in position 2, R 7 is placed in position 4 and R 1 is placed in position 6 of the quinoline ring, said intermediates being represented by formula (XII-a), can be prepared by reacting an intermediate of formula (XV) with an intermediate of formula (XIV) in the presence of a suitable coupling agent, such as for example n-butyl lithium, secBuLi, and in the presence of a suitable solvent, such as for example tetrahydrofuran, and optionally in the presence of a suitable base, such as for example 2,2,6,6-tetramethylpiperidine, NH(CH 2 CH 2 CH 3 ) 2 , N,N-diisopropylamine or trimethylethylenediamine.
Intermediates of formula (III) are compounds that are either commercially available or may be prepared according to conventional reaction procedures generally known in the art. For example, intermediate compounds of Formula (III) wherein q is equal to 1, said intermediates being represented by formula (III-a), can be prepared according to the following reaction scheme (1).
Reaction scheme (1) comprises step (a) in which an appropriately R 3 is reacted by Friedel-Craft reaction with an appropriate acylchloride such as 3-chloropropionyl chloride or 4-chlorobutyryl chloride, in the presence of a suitable Lewis acid, such as AlCl 3 , FeCl 3 , SnCl 4 , TiCl 4 or ZnCl 2 and a suitable reaction-inert solvent, such as methylene chloride or ethylene dichloride. The reaction may conveniently be carried out at a temperature ranging between room temperature and reflux temperature. In a next step (b) an amino group (e.g. —NR 4 R 5 ) is introduced by reacting the intermediate compound obtained in step (a) with an appropriate amine.
Intermediates of formula (III) can also be prepared by reacting an intermediate of formula (XVI) and an intermediate of formula (XVII) with formaldehyde in the presence of a suitable solvent, such as for example an alcohol, e.g. ethanol, and a suitable acid, e.g. HCl.
It is evident that in the foregoing and in the following reactions, the reaction products may be isolated from the reaction medium and, if necessary, further purified according to methodologies generally known in the art, such as extraction, crystallization and chromatography. It is further evident that reaction products that exist in more than one enantiomeric form, may be isolated from their mixture by known techniques, in particular preparative chromatography, such as preparative HPLC. Typically, compounds of Formula (I) may be separated into their isomeric forms.
The following examples illustrate the present invention without being limited thereto.
EXPERIMENTAL PART
Of some compounds the absolute stereochemical configuration of the stereogenic carbon atom(s) therein was not experimentally determined. In those cases the stereochemically isomeric form which was first isolated is designated as “A” and the second as “B”, without further reference to the actual stereochemical configuration. However, said “A” and “B” isomeric forms can be unambiguously characterized by a person skilled in the art, using art-known methods such as, for example, X-ray diffraction, The isolation method is described in detail below.
For some of the final compounds, stereochemical configurations are indicated in the structures. These configurations are relative configurations indicating that the groups concerned are located in the same or opposite plane of the molecule ( =same plane; =opposite plane)
Hereinafter, “DIPE” is defined as diisopropyl ether, “THF” is defined as tetrahydrofurane, “HOAc” is defined as acetic acid, “EtOAc” is defined as ethylacetate.
A. Preparation of the Intermediate Compounds
Example A1
Preparation of Intermediate 1 and Intermediate 2
A mixture of 5-bromo-1H-indole-2,3-dione (0.221 mol) in NaOH 3N (500 ml) was stirred at 80° C. for 30 minutes and then cooled to room temperature. 4-Phenyl-2-butanone (0.221 mol) was added. The mixture was stirred and refluxed for 90 minutes, cooled to room temperature and acidified with HOAc until pH=5. The precipitate was filtered off, washed with H 2 O and dried. Yield: 75 g (95%) of a mixture of intermediate 1 and intermediate 2.
Example A2
Preparation of Intermediate 3
A mixture of intermediate 1 and intermediate 2 (0.21 mol) in 1,1′-oxybis[benzene] (600 ml) was stirred at 300° C. for 12 hours. EtOAc was added. The mixture was extracted three times with HCl 6N, basified with K 2 CO 3 solid and extracted with CH 2 Cl 2 . The organic layer was separated, dried (MgSO 4 ), filtered and the solvent was evaporated. The residue (36 g) was purified by column chromatography over silica gel (eluent: CH 2 CH 2 /CH 3 OH 99/1; 15-40 μm). The pure fractions were collected and the solvent was evaporated. Yield: 11 g (16%) of intermediate 3.
Example A3
Preparation of Intermediate 4
A mixture of 1-(3-fluorophenyl)ethanone (0.195 mol), formaldehyde (0.235 mol) and NH(CH 3 ) 2 .HCl (0.235 mol) in ethanol (300 ml) and HCl conc. (1 ml) was stirred and refluxed overnight, then brought to room temperature. The precipitate was filtered, washed with ethanol and dried. The mother layer was evaporated. The residue was taken up in diethyl ether. The precipitate was filtered, washed with diethyl ether and dried. This fraction was taken up in K 2 CO 3 10%. The precipitate was washed with CH 2 CH 2 and dried. Yield: 18.84 g (49%) of intermediate 4.
Example A4
a. Preparation of Intermediate 5
A mixture of 6-bromo-2(1H)-quinolinone (0.089 mol) in POCl 3 (55 ml) was stirred at 60° C. overnight, then at 100° C. for 3 hours and the solvent was evaporated. The residue was taken up in CH 2 Cl 2 , poured out into ice waters basified with NH 4 OH concentrated, filtered over celite and extracted with CH 2 Cl 2 . The organic layer was separated, dried (MgSO 4 ), filtered and the solvent was evaporated. Yield: 14.5 g of intermediate 5 (67%).
b. Preparation of Intermediate 6
A mixture of Zn (0.029 mol) and 1,2-dibromoethane (0.001 mol) in THF (6 ml) was stirred and refluxed for 10 minutes, then cooled to room temperature. Chlorotrimethylsilane (0.001 mol) was added. The mixture was stirred at room temperature for 30 minutes. A solution of bromomethylbenzene (0.025 mol) in THF (25 ml) was added dropwise at 5° C. for 90 minutes. The mixture was stirred at 0° C. for 2 hours. A solution of intermediate 5 (prepared according to A4.a) (0.021 mol) in THF (75 ml) was added. Pd(PPh 3 ) 4 (0.0008 mol) was added. The mixture was stirred and refluxed for 2 hours, then cooled to room temperature, poured out into NH 4 Cl 10% and extracted with EtOAc. The organic layer was washed with H 2 O, then with satured NaCl, dried (MgSO 4 ), filtered, and the solvent was evaporated. The residue (12 g) was purified by column chromatography over silica gel (eluent: cyclohexane/CH 2 Cl 2 50/50; 20-45 μm). Two fractions were collected and the solvent was evaporated. Yield of the second fraction. 2.5 g of intermediate 6.
Example A5
a. Preparation of Intermediate 7
nBuLi (1.6 M) (0.066 mol) was added dropwise at −50° C. to a mixture of 6-bromo-2-chloro-3-ethylquinoline (0055 mol) in THF (150 ml). The mixture was stirred at 50° C. for 1 hour. A solution of benzaldehyde (0.066 mol) in THF (70 ml) was added at −70° C. The mixture was stirred at −70° C. for 1 hour, poured out into H 2 O at 0° C. and extracted with EtOAc. The organic layer was separated, dried (MgSO 4 ), filtered, and the solvent was evaporated. The residue (15 g) was crystallized from DIPE/iPrOH. The precipitate was filtered off and dried. Yield: 7.6 g of intermediate 7 (46%).
b. Preparation of Intermediate 8
A mixture of intermediate 7 (prepared according to A5.a) (0.021 mol), Et 3 SiH (0.21 mol) and CF 3 COOH (0.21 mol) in CH 2 Cl 2 (100 ml) was stirred at room temperature for 3 days. H 2 O was added. The mixture was extracted with CH 2 Cl 2 . The organic layer was separated, washed with K 2 CO 3 10%, dried over magnesium sulfate, filtered and the solvent was evaporated. The residue (8 g) was purified by column chromatography over silica gel (eluent: cyclohexane/AcOEt 95/5; 15-40 μm). The pure fractions were collected and the solvent was evaporated. Yield: 3.8 g (64%, m.p.: 66° C.).
Example A6
a. Preparation of Intermediate 9
n-Butyl lithium (0.055 mol) was added slowly at −70° C. to a mixture of 7-bromo-2-chloro-3-ethylquinoline (0.37 mol) in THF (100 ml) under N 2 flow. The mixture was stirred for 2 hours, then a solution of benzaldehyde (0.055 mol) in THF (55 ml) was added. The mixture was stirred for 3 hours, water was added at −20° C. and the mixture was extracted with EtOAc. The organic layer was separated, dried over magnesium sulfate, filtered and the solvent was evaporated. The residue (12.2 g) was purified by column chromatography over silica gel (eluent: cyclohexane/AcOEt 80/20; 15-40 μm). The pure fractions were collected and the solvent was evaporated. Yield: 6.1 g of intermediate 9 (56%).
b. Preparation of Intermediate 10
A mixture of intermediate 9 (prepared according to A6.a) (0.0205 mol), Et 3 SiH (0.205 mol) and CF 3 COOH (0.205 mol) in CH 2 CH 2 (300 ml) was stirred at room temperature for 7 days. H 2 O was added. The mixture was extracted with CH 2 Cl 2 . The organic layer was separated, washed with K 2 CO 3 10%, dried over magnesium sulfate, filtered and the solvent was evaporated. The residue (7.1 g) was purified by column chromatography over silica gel (eluent:cyclohexane/AcOEt 95/5; 15-40 μm). The pure fractions were collected and the solvent was evaporated. Yield: 4.8 g of intermediate 10 (83%).
Example A7
a. Preparation of Intermediate 11
n-Butyl lithium (0.0090 mol) was added slowly at −20° C. to a mixture of 2,2,6,6-tetramethylpiperidine (0.0090 mol) in THF (15 mL) under N 2 flow. The mixture was stirred for 20 minutes, then cooled to −70° C. A solution of 6-bromo-2-chloro-4-phenylquinoline (0.0060 mol) in THF (40 mL) was added. The mixture was stirred for 1 hour. A solution of benzaldelhyde (0.0090 mol) in THF (15 ml) was added. The mixture was stirred for 1 hour at −70° C. then 3 hours at room temperature. H 2 O was added. The mixture was extracted with EtOAc. The organic layer was separated, dried over magnesium sulfate, filtered and the solvent was evaporated. The residue (3.0 g) was purified by column chromatography over silica gel (eluent: cyclohexane/AcOEt: 95/5; 15-40 μm). The pure fractions were collected and the solvent was evaporated. Yield: 1.8 g of intermediate 11 (71%).
b. Preparation of Intermediate 12
A mixture of intermediate 11 (prepared according to A7.a) (0.0042 mol), Et 3 SiH (0.0424 mol) and CF 3 COOH (0.0424 mol) in CH 2 Cl 2 (100 ml) was stirred at room temperature for 24 hours. H 2 O was added. The mixture was extracted with CH 2 Cl 2 . The organic layer was separated, washed with K 2 CO 3 10%, dried over magnesium sulfate, filtered and the solvent was evaporated. The residue (1.3 g) was crystallized from DIPE. The precipitate was filtered off and dried. Yield: 0.66 g (38%, m.p.: 121° C.)
B. Preparation of the Final Compounds
Example B1
Preparation of Compound 1 and Compound 4
nBuLi 1.6M (0.0072 mol) was added at −20° C. to a mixture of N-(1-methylethyl)-2-propanamine.hydrochloride (1:1) (0.0071 mol) in THF (25 ml) under nitrogen stream. The mixture was stirred for 20 minutes then cooled to −70° C. A solution of intermediate 3 (0.0061 mol) in THF (5 ml) was added. The mixture was stirred for 2 hours. A solution of intermediate 4 (0.0061 mol) in THF (5 ml) was added at −70° C. The mixture was stirred at −70° C. for 3 hours. NH 4 Cl 10% was added. The mixture was extracted with EtOAc. The organic layer was separated, dried (MgSO 4 ), filtered, and the solvent was evaporated. The residue (3.4 g) was purified by column chromatography over silica gel (eluent: CH 2 CH 2 /CH 3 OH/NH 4 OH 97/3/0.1; 15-40 μm). Two fractions were collected and the solvent was evaporated. The first residue (0.9 g) was crystallized from diisopropyl ether. The precipitate was filtered off and dried. Yield: 0.49 g of compound 1 (diastereoisomer A) (m.p.: 136° C.). The second residue (0.79 g) was crystallized from diisopropyl ether. The precipitate was filtered off and dried. Yield: 0.105 g of compound 4 (diastereoisomer B) (m.p.: 179° C.).
Example B2
Preparation of Compound 2 and Compound 3
nBuLi 1.6M (0.0072 mol) was added dropwise at −20° C. to a solution of N-(1-methylethyl)-2-propanamine.hydrochloride (1:1) (0.0071 mol) in THF (25 ml) under nitrogen stream. The mixture was stirred for 20 minutes. Then cooled to −70° C. A solution of intermediate 3 (0.0061 mol) in THF (5 ml) was added. The mixture was stirred for 2 hours. A solution of 3-(dimethylamino)-1-(1-naphthalenyl)-1-propanone (0.0062 mol) in THF (5 ml) was added at −70° C. The mixture was stirred at −70° C. for 3 hours. NH 4 Cl 10% was added. The mixture was extracted with EtOAc. The organic layer was separated, dried (MgSO 4 ), filtered, and the solvent was evaporated. The residue (4 g) was purified by column chromatography over silica gel (eluent: CH 2 Cl 2 /CH 3 OH/NH 4 OH 97/3/0.1; 15-40 μm). Two fractions were collected and the solvent was evaporated. The first residue (0.61 g) was crystallized from DIPE. The precipitate was filtered off and dried. Yield: 0.303 g of compound 2 (diastereoisomer A) (m.p. 143° C.). The second residue (0.56 g) was purified by column chromatography over silica gel (eluent: CH 2 Cl 2 /CH 3 OH 98/2). The pure fractions were collected and the solvent was evaporated. Yield: 0.104 g of compound 3 (diastereoisomer 1) (m.p.: 69° C.).
Example B3
Preparation of Compound 5 and 6
n-BuLi 1.6M (0.0048 mol) was added at −70° C. to a mixture of N-(1-methylethyl)-2-propanamine (0.0049 mol) in THF (15 ml). The mixture was stirred at −20° C. for 20 minutes. A solution of intermediate 6 (prepared according to A4.b) (0.004 mol) in THF (5 ml) was added at −70° C. The mixture was stirred at −70° C. for 2 hours. A solution of intermediate 4 (prepared according to A3) (0.004 mol) in THF (5 ml) was added at −70° C. The mixture was stirred at −70° C. for 3 hours. NH 4 Cl 10% was added. The mixture was extracted with EtOAc. The organic layer was separated, dried (MgSO 4 ), filtered, and the solvent was evaporated. Yield: 2.1 g. This fraction was purified by column chromatography over silica gel (eluent: CH 2 Cl 2 /CH 3 OH/NH 4 OH 96.5/3.5/0.1; 15-40 μm). Two fractions were collected and the solvent was evaporated. Yield: 0.123 g of fraction A and 0.122 g of fraction B. Fraction A was purified by column chromatography over silica gel (eluent: CH 2 Cl 2 /CH 3 OH 98/2; 15-40 μm). The pure fractions were collected and the solvent was evaporated. Yield: 0.119 g. This fraction was taken up in iPr 2 O/pentane. The mixture was evaporated. Yield: 0.077 g of compound 5 (mp.: 58° C.). Fraction B was crystallized from DIPE. The precipitate was filtered off and dried. Yield: 0.039 g of compound 6 (mp.: 134° C.).
Example B4
Preparation of Compound 13 and 14
n-BuLi 1.6M (0.013 mol) was added at −20° C. to a mixture of N-(1-methylethyl)-2-propanamine (0.013 mol) in THF (25 ml) under N 2 flow. The mixture was stirred at −20° C. for 20 minutes, then cooled to −70° C. A solution of intermediate 8 (prepared according to A5.b) (0.0106 mol) in THF (25 ml) was added. The mixture was stirred at −70° C. for 45 minutes. A solution of 3-(dimethylamino)-1-(1-naphthalenyl)-1-propanone (0.013 mol) in THF (20 ml) was added. The mixture was stirred at −70° C. for 2 hours, poured out into H 2 O at −30° C. and extracted with EtOAc. The organic layer was separated, dried (MgSO 4 ), filtered, and the solvent was evaporated. The residue (5.5 g) was purified by column chromatography over silica get (eluent: CH 2 Cl 2 /CH 3 OH/NH 4 OH 99/1/0.1; 15-40 μm). Two fractions were collected and the solvent was evaporated. Yield: 0.33 g of compound 13 (diastereoisomer A) (3%) and 0.11 g of compound 14 (diastereoisomer B) (1%).
Following compound was prepared according to the above procedure. The purification of the residue (*) is indicated because different from the above-described purification.
compound 15
The residue (5.4 g) was purified by column chromatography over silica gel (eluent: CH 2 Cl 2 /CH 3 OH 98/2; 15- 40 μm). The pure fractions were collected and the solvent was evaporated. Yield: 0.17 g of compound 15 (mixture of diastereoisomer A and diastereoisomer B: 45/55) (3%).
Example B5
Preparation of Compound 7 and 8
n-Butyl lithium (0.0043 mol) was added slowly at −20° C. to a mixture of diisopropyl amine (0.0043 mol) in THF (10 ml) under N 2 flow. The mixture was stirred for 20 minutes, then cooled to −70° C. A solution of intermediate 10 (prepared according to A6.b) (0.0036 mol) in THF (10 ml) was added. The mixture was stirred for 2 hours. A solution of 3-(dimethylamino)-1-(1-naphthalenyl)-1-propanone (0.0043 mol) in THF (10 ml) was added. The mixture was stirred for 2 hours. H 2 O was added. The mixture was extracted with EtOAc. The organic layer was separated, dried over magnesium sulfate, filtered and the solvent was evaporated. The residue (*) (1.8 g) was purified by column chromatography over silica gel (eluent: CH 2 Cl 2 /MeOH/NH 4 OH 98/2/0.2; 1-40 μm). Two fractions were collected and the solvent was evaporated. Yield: 0.17 g of fraction 1 and 0.15 g of fraction 2. Fraction 1 was crystallized from MeOH. The precipitate was filtered off and dried. Yield: 0.082 g of compound 7 (5%, diastereoisomer A). Fraction 2 was purified by column chromatography over silica gel (eluent: CH 2 Cl 2 /MeOH: 98/2; 15-40 μm). The pure fractions were collected and the solvent was evaporated. Yield: 0.13 g of compound 8 (7%, diastereoisomer B).
Following compounds were prepared according to the above procedure. The purification of the residue (*) is indicated because different from the above-described purification.
compound 9 and compound 10
The residue (1.9 g) was purified by column chromatography over silica gel (eluent: CH 2 Cl 2 /MeOH: 99/1; 15- 40 μm). Two fractions were collected and the solvent was evaporated. Yield: Fraction 1: 0.42 g of diastereoisomer A and fraction 2: 0.31 g (18%) of compound 9 (diastereoisomer B). Fraction 1 was crystallized from CH 3 OH. The precipitate was filtered off and dried. Yield: 0.22 g of compound 10 (diastereoisomer A) (13%; m.p.: 185° C.).
Example B6
Preparation of Compound 11 and 12
n-Butyl lithium (0.002 mol) was added slowly at −20° C. to a mixture of diisopropyl amine (0.002 mol) in THF (5 mL) under N 2 flow. The mixture was stirred for 20 minutes, then cooled to −70° C. A solution of intermediate 12 (prepared according to A7.b) (0.0017 mol) in THF (7 ml) was added. The mixture was stirred for 2 hours. A solution of 1-(3,5-difluorophenyl)-3-dimethylamino-1-propanone (−(0.002 mol) in THF (4 ml) was added. The mixture was stirred for 2 hours. H 2 O was added. The mixture was extracted with EtOAc. The organic layer was separated, dried over magnesium sulfate, filtered and the solvent was evaporated. The residue (1.1 g) was purified by column chromatography over silica gel (eluent: CH 2 Cl 2 /MeOH: 9911; 15-40 μm). Two fractions were collected and the solvent was evaporated. Yield: 0.061 g of fraction 1 and 0.070 g of fraction 2. Fraction 1 was crystallized from MeOH. The precipitate was filtered off and dried. Yield: 0.046 g of compound 11 (5%, m.p.: 220° C., diastereoisomer A). Fraction 2 was crystallized from MeOH. The precipitate was filtered off and dried. Yield: 0.053 g (5%, m.p.: 216° C., diastercoisomer B).
C. Analytical Methods
The mass of the compounds was recorded with LCMS (liquid chromatography mass spectrometry). Three methods were used which are described below. The data are gathered in Table 1 below.
LCMS-Method 1
LCMS analysis was carried out (electrospray ionization in positive mode, scanning mode from 100 to 900 amu) on a Kromasil C18 column (Interchim, Montluçon, FR; 5 μm, 4.6×150 mm) with a flow rate of 1 ml/minute. Two mobile phases (mobile phase A: 30% 6.5 mM ammonium acetate+40% acetonitrile+30% formic acid (2 ml/l); mobile phase B: 100% acetonitrile) were employed to run a gradient condition from 100% A for 1 minute to 100% B in 4 minutes, 100% B for 5 minutes to 100% A in 3 minutes, and reequilibrate with 100% A for 2 minutes.
LCMS-Method 2
LCMS analysis was carried out (electrospray ionization in both positive and negative (pulsed) mode scanning from 100 to 1000 amu) on a Kromasil C18 column (Interchim, Montluçon, FR; 3.5 μm, 4.6×100 mm) with a flow rate of 0.8 ml/minute. Two mobile phases (mobile phase A: 35% 6.5 mM ammonium acetate+30% acetonitrile+35% formic acid (2 ml/l); mobile phase B: 100% acetonitrile) were employed to run a gradient condition from 100% A for 1 minute to 100% B in 4 minutes, 100% B at a flow rate of 1.2 ml/minute for 4 minutes to 100% A at 0.8 ml/minute in 3 minutes, and reequilibrate with 100% A for 1.5 minute.
TABLE 1
LCMS parent peak
LCMS-
No.
MH+
method
Compound 7
509
1
compound 9
495
2
compound 15
495
1
compound 13
509
1
compound 14
509
1
D. Pharmacological Examples
D.1. In-Vitro Method for Testing Compounds Against M. Tuberculosis
Flat-bottom, sterile 96-well plastic microtiter plates were filled with 100 μl of Middlebrook (1×) broth medium. Subsequently, stock solutions (10× final test concentration) of compounds were added in 25 μl volumes to a series of duplicate wells in column 2 so as to allow evaluation of their effects on bacterial growth. Serial five-fold dilutions were made directly in the microtiter plates from column 2 to 11 using a customised robot system (Zymark Corp., Hopkinton, Mass.). Pipette tips were changed after every 3 dilutions to minimize pipetting errors with high hydrophobic compounds. Entreated control samples with (column 1) and without (column 12) inoculum were included in each microtiter plate. Approximately 5000 CFU per well of Mycobacterium tuberculosis (strain H37RV), in a volume of 100 μl in Middlebrook (1×) broth medium, was added to the rows A to H, except column 12. The same volume of broth medium without inoculum was added to column 12 in row A to H. The cultures were incubated at 37° C. for 7 days in a humidified atmosphere (incubator with open air valve and continuous ventilation). One day before the end of incubation, 6 days after inoculation, Resazurin (1:5) was added to all wells in a volume of 20 μl and plates were incubated for another 24 hours at 37° C. On day 7 the bacterial growth was quantitated fluorometrically.
The fluorescence was read in a computer-controlled fluorometer (Spectramax Gemini EM, Molecular Devices) at an excitation wavelength of 530 nm and an emission wavelength of 590 nm. The percentage growth inhibition achieved by the compounds was calculated according to standard methods, and MIC data (representing IC90's expressed in microgram/ml) were calculated.
D.2. In-Vitro Method for Testing Compounds for Anti-Bacterial Activity Against Strain M. Smegmatis ATCC607
Flat-bottom, sterile 96-well plastic microtiter plates were filled with 180 μl of sterile deionized water, supplemented with 0.25% BSA. Subsequently, stock solutions (7.8× final test concentration) of compounds were added in 45 μl volumes to a series of duplicate wells in column 2 so as to allow evaluation of their effects on bacterial growth. Serial five-fold dilutions (45 μl in 180 μl) were made directly in the microtiter plates from column 2 to 11 using a customised robot system (Zymark Corp. Hopkinton, Mass.). Pipette tips were changed after every 3 dilutions to minimize pipetting errors with high hydrophobic compounds. Untreated control samples with (column 1) and without (column 12) inoculum were included in each microtiter plate. Approximately 250 CFU per well of bacteria inoculum, in a volume of 100 μl in 2.8× Mueller-Hinton broth medium, was added to the rows A to H, except column 12. The same volume of broth medium without inoculum was added to column 12 in row A to H. The cultures were incubated at 37° C. for 48 hours in a humidified 5% CO 2 atmosphere (incubator with open air valve and continuous ventilation). At the end of incubation, two days after inoculation, the bacterial growth was quantitated fluorometrically. Therefore Alamar Blue (10×) was added to all wells in a volume of 20 μl and plates were incubated for another 2 hours at 50° C.
The fluorescence was read in a computer-controlled fluorometer (Cytofluor, Biosearch) at an excitation wavelength of 530 nm and an emission wavelength of 590 nm (gain 30). The % growth inhibition achieved by the compounds was calculated according to standard methods. The pIC 50 was defined as the 50% inhibitory concentration for bacterial growth. The results are shown in Table 2.
TABLE 2
Results of an in vitro-screening of the compounds according to the
invention for M. smegmatis (pIC 50 ) and M. tuberculosis (pIC 50 )
M. smegmatis
M. tuberculosis
Co. No.
pIC 50
pIC 50
1
6.2
2
6.5
3
5.7
6
4.9
15
6.4
5
10
5.9
5.1
14
5.9
13
5.8
9
5.8
8
5.8
11
5.7
|
The present invention relates to novel substituted quinoline derivatives according to the general Formula (I)
and pharmaceutically acceptable addition salts thereof, wherein the variable moieties are as defined in the specification. The invention also relates to a method of treating of mycobacterial diseases through administration of the claimed compounds and a process for preparing the claimed compounds.
| 2
|
This application is a continuation, of application Ser. No. 07/868,770, filed Apr. 16, 1992, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multiprocessor system utilizing dual-port random access memories (referred to as "DPMs", hereinafter) each used as a memory circuit (referred to as a "shared memory" hereinafter) shared by a host central processing unit (host-CPU) circuit and one of the sub-central processing unit (sub-CPU) circuits and, particularly, to a method of detecting abnormal operation of any of the sub-CPU circuits and resetting the sub-CPU circuit operating abnormally.
2. Description of the Prior Art
A conventional multiprocessor system of this kind includes a host-CPU circuit, a plurality of sub-CPU circuits and shared memories corresponding in number to the sub-CPU circuits. Each of the host-CPU circuit and the sub-CPU circuits includes a CPU for processing data, etc., a read-only memory (ROM) circuit for storing programs, etc., of the CPU circuit, a random access memory (RAM) circuit used for arithmetic operations, an input-output (I/O) circuit which is an interface circuit between the CPU and external devices, and a watch-dog timer circuit (U.S. Pat. No. 4,752,930) for monitoring operations of the CPU. The host-CPU circuit and each sub-CPU circuit share a DPM as a shared memory for data, etc. In such multiprocessor systems, the sub CPU circuits collect data, such as alarm information of devices and performance information in the DMPs associated therewith, and the host-CPU circuit processes the data stored in the DPMs.
The host- and sub-CPU circuits are continuously monitored by the internally provided watch-dog timers, respectively, and, when any CPU circuit operates abnormally, for example, it runs abnormally, the CPU circuit is reset by the associated watch-dog timer. Since, however, the DPM connected thereto may have been written with abnormal data before such resetting of the CPU, or normal data is lost by the resetting operation, the reliability of data in the DPM is lost as a whole. Further, it is inevitable that any CPU which operates abnormally may read in data written from a CPU operating normally as different data and/or read in data from an erroneous address. That is, when any of CPUs of the multiprocessor system becomes abnormal, data commonly stored in the DPM associated therewith becomes meaningless.
Further, the host-CPU circuit or the sub-CPU circuit cannot know when the sub-CPU circuit or the host-CPU circuit becomes abnormal and therefore there is a problem of data inconsistently occurred in exchange of data between them. For example, the host-CPU cannot detect the loss of data in the DPM due to resetting of an associated sub-CPU. Therefore, the host-CPU circuit may process data a portion of which is lost as if it is correct data. When such erroneous data thus processed as correct data is used by another sub-CPU circuit through the host-CPU circuit, the influence of data loss may be spread over the whole processor system.
Further, in the multiprocessor system, since each CPU requires a watch-dog timer, it becomes expensive.
SUMMARY OF THE INVENTION
Object of the Invention
Therefore, a first object of the present invention is to provide a multiprocessor system which is not influenced by erroneous data, a portion of which is lost due to abnormal operation of any of CPU circuits constituting the multiprocessor system.
A second object of the present invention is to provide a multiprocessor system in which a host-CPU circuit monitors sub-CPU circuits and can reset any of the sub CPU circuits which operate abnormally.
A third object of the present invention is to provide a multiprocessor system which includes a single watch-dog timer circuit.
Summary of the Invention
A multiprocessor system according to the present invention comprises, similarly to the conventional multiprocessor systems, a host-CPU circuit including a host CPU, a ROM, a RAM and an I/O connected by bus lines mutually, a plurality of sub-CPU circuits each including a sub-CPU, a ROM, a RAM and an I/O connected by bus lines mutually and a plurality of DPMs corresponding in number to the sub-CPU circuits, each of the DPMs being connected to the host-CPU and one of the sub-CPUs by respective bus lines such that it is accessed thereby. The host-CPU has an internal watch-dog timer.
Each sub-CPU circuit periodically provides predetermined monitor information related to the sub-CPU by means of monitor means constituted with the sub-CPU circuit itself and a software, and writes it in a monitor information memory portion of the DPM shared by the host-CPU connected thereto. It should be noted that the monitor information of the sub-CPU is sometimes referred to as "operation information". On the other hand, monitor and detection means, constituted by the host-CPU circuit and software, monitors an operation of the sub-CPU by reading the operation information of the sub-CPU from the DPM thereof. When an abnormal operation of the sub-CPU is detected from the operation information, the monitor and detection means sends a reset signal to a reset terminal of the abnormal sub-CPU through control means to reset the abnormally operating sub-CPU and, at the same time, inhibit data write from a data memory portion of the DPM.
When status information of data collected in the data memory portion of the DPM is also stored in a portion of the monitor information memory portion of the DPM as one of monitor information and the monitor means of the sub-CPU circuit has means for detecting the operation information and the status information in the DPM, the sub-CPU itself can detect an abnormality of the collected data in the DPM and inhibit collected data write in the DPM connected thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a block diagram of an embodiment of a multiprocessor system according to the present invention;
FIG. 2 is a diagrammatic illustration of a memory region of a DPM 7a shown in the embodiment in FIG. 1;
FIG. 3 is a flowchart of an operation of a CPU 2 used in the embodiment in FIG. 1;
FIG. 4 is a flowchart of an operation of a CPU 11a used in the embodiment in FIG. 1; and
FIG. 5 shows memory statuses of monitor information #1 and #2 in respective operation steps in FIGS. 3 and 4, in which (a) shows a normal operation and (b) to (d) show abnormal operations, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a multiprocessor system according to the present invention comprises a host-CPU circuit including a CPU 2 and two sub-CPU circuits including CPUs 11a and 11b, respectively. These sub-CPU circuits collect, through the I/Os 12a and 12b, alarm information and performance information of external devices (not shown) connected thereto in DPMs 7a and 7b, which are memories share with the host-CPU 2. The host-CPU circuit processes the data collected in the DPMs 7a and 7b.
The host-CPU circuit includes the CPU 2, a ROM 3 storing programs, etc., of the host-CPU circuit, a RAM 4 which is a memory for arithmetic operations, etc., an I/O 5 which is an interface with respect to external devices (not shown) and a bus line 6 for connecting these components mutually and connecting a first input/output terminal of the DPM 7a to a first input/output terminal of the DPM 7b. Further, one of the sub-CPU circuits, that is, a first sub CPU circuit, include a sub-CPU 11a, a bus line 8a which connects the CPU 11a, the I/O 12a, the ROM 9a for storing the programs, etc., of the sub-CPU circuits, the RAM 10a which is a memory for arithmetic operations, the above-mentioned components and a second input/output terminal of the DPM 7a, mutually. The second sub-CPU circuit includes a sub-CPU 11b , a bus line 8b which connects the CPU 11b, the I/O 12b, the ROM 9b for storing the programs, etc., of the sub-CPU circuit, the RAM 10b which is a memory for arithmetic operations, the above-mentioned components and a second input/output terminal of the DPM 7b, mutually.
An operation of this multiprocessor system will be described with reference to FIGS. 1 and 2, paying special attention to a monitor and reset operation for an abnormal operation of one of the sub-CPU circuits. Since operation of the host-CPU circuit with respect to the first sub-CPU circuit is the same as that with respect to the second sub CPU circuit, only exchange of data and monitor of information #1 and #2 between the host CPU circuit and the first sub-CPU circuit will be described.
The DPM 7a has a data portion 71 for storing data taken through the I/O 12b in the CPU 11a and a monitor information memory portion 72 for storing the operation information #1 produced by the CPU 11a and the monitor information #2 which is a status information enabling data read/write of the DPM 7a. The operation information #1 is composed of mutually different data A and B alternating every predetermined data collection period during the periods when CPU 11a operates normally. The monitor information #2 comprises a flag 1 for enabling the CPU 11a to write data to the data portion 71 and a flag clear for enabling the CPU 2 to read data from the data portion 71 and, during a normal operation of the CPUs 2 and 11a, the CPU 2 and the CPU 11a write the flag 1 and the flag clear in the monitor information memory portion 72, alternatively.
During a normal processing in normal operation of the CPU 11a, the CPU 11a stores the operation information #1 in a monitor information memory portion 72 after data write to the data portion 71. On the other hand, the CPU 2 accesses the monitor information memory portion 72 to read the operation information #1 before the data is read from the data portion 71 and compares a current operation information #1 with a preceding operation information #1a having been stored in the RAM 4. When the result of the comparison indicates a normal operation of the CPU 11a, the CPU 2 reads the data from the data portion 71 and processes data of the sub-CPU circuit including that data. On the other hand, when an abnormality of the operation of the CPU 11a is detected, the CPU 2 does neither read data from the data portion 72 nor perform data processing mentioned above. Instead thereof, the CPU 2 sends a reset signal S3 through the I/O 5 and a control line 23 to a reset terminal RST of the CPU 11a to reset the latter.
In this case, this operation of the CPU 2 is continuously monitored by a watch-dog timer 1 which is reset by a signal S2 having a constant period and supplied from the I/O 5 through a signal line 22. When there is an abnormal operation occurred in the CPU 2, the watch-dog timer 1 resets the CPU 2 by a reset signal S1 on a control line 21. When the CPU 2 is reset in this manner, the CPU 11a is also reset in any of the following manners. In a first manner, the CPU 2 automatically sends a reset signal S3 on a signal line 23 to reset the CPU 11a. In the second manner, the CPU 2 checks the operation information #1 in the monitor information memory portion 72 of the DPM 7a and, when there is an abnormality in the CPU 11a, sends the reset signal S3 to reset the CPU 11a. In the third manner, the CPU 2 checks the operation information #1 read out from the monitor information memory portion 72 of the DPM 7a and data (data length, data number and data content) read out from the data portion 71 and, when there is any inconsistency therebetween, resets the CPU 11a.
An operation flow of the CPU 2 in the embodiment shown in FIG 1 will be described with reference to FIG. 3, paying a special attention to a monitor and reset operation for an abnormal operation of the CPU 11a.
When this multiprocessor system is started, the CPU 2 sets the RAM 4 and the DPM 7a to normal values, respectively (step 311). Then, the CPU 2 periodically reads the operation information #1 of the CPU 11a which is stored in the monitor information memory portion 72 of the DPM 7a (Step 312). Further, the CPU 2 compares the preceding operation information #1a stored in the RAM 4 with the above-mentioned operation information #1 (Step 313). When the result of the comparison indicates a normal operation of the CPU 11a (OK in Step 313), the CPU 2 reads data from the data portion 71 of the DPM 7a (Step 314). Upon completion of the normal data read in the Step 314, the CPU 2 writes flag 1 as the monitor information #2 in the monitor information memory portion 72 (Step 315) and enables data write from the CPU 11a to the DPM 7a. Simultaneously, the CPU 2 memorizes the current operation information #1 in the RAM 4 (Step 316). In this case, it should be noted that the operation information #1 stored in the Step 316 becomes the preceding operation information #1a. Thereafter, the CPU 2 performs the same operation for the DPM 7b and processes data read in from the DPMS 7a and 7b (Step 317).
When the comparison performed in the Step 313 indicates an abnormal operation (NG), the CPU 2 performs the reference at least twice (Step 318). When there is not at least two successive NG occurrences (NO in Step 318), the CPU 2 determines that the CPU 11a is normal and is shifted to the normal operation in the Step 315 with only one stop of data read from the data portion 71. On the other hand, when there are at least two successive NG occurrences (YES in Step 318), the CPU 2 determines that the CPU 11a is abnormal (Step 319) and then sends a reset signal S3 through the I/O 5 and the control line 23 to reset the CPU 11a (Step 320). Then, the CPU 2 returns to the Step 312 and performs the data read operation again.
An operation flow of the CPU 11a in the embodiment in FIG. 1 will be described in detail with reference to FIG. 4, paying special attention to the abnormality monitoring operation thereof.
When the multiprocessor system is started, the CPU 11a sets the RAM 10a and the DPM 7a to normal values respectively (Step 411). Then, the CPU 11a periodically collects data from external devices through the I/O 12a (Step 412). Thereafter, the CPU 11a reads the current operation information #1 and the current monitor information #2 from the monitor information memory portion 72 of the DPM 7a (Step 413) and the preceding operation information #1a and the preceding monitor information #2a from the RAM 10a (Step 414). The CPU 11a compares the current operation information #1 with the preceding operation information #1a (Step 415). When it is confirmed by this comparison that the CPU 11 a is normal (OK in Step 415), the CPU 11a sets and stores the current operation information #1 in the RAM 10a (Step 416). It should be noted that the operation information #1 stored in this stage becomes the preceding operation information #1a. The CPU 11a checks the monitor information #2 which had been read (Step 417). When the check indicates OK (the monitor information #2 is flag 1) and a normal operation of the CPU 2 and a normality of data in the data portion 71 are confirmed, the CPU 11a writes the collected data in the data portion 71 of the DPM 7a (Step 418). Further, the CPU 11a writes the current operation information #1 in the monitor information memory portion 71, clears the monitor information #2 (Step 419) and then returns to the Step 412.
When the reference in the Step 415 indicates NG, the CPU 11a writes the operation information #1 set in the monitor information memory portion 72 in the RAM 10a (Step 420) and shifts to the Step 419. As a result, the data collected once by the CPU 11a is discarded.
When data abnormality in the data portion 71 is detected by the reference result of NG in the Step 417, the CPU 11a does not perform a data write to the data portion 71 and shifts to the Step 412 to perform the operation starting from the data collection again.
Referring now to FIG. 5(a), in a normal processing of the multiprocessor system during normal operation, the CPU 11a writes the operation information #1, which includes alternative data A and B, in the data collecting periods thereof in the monitor information memory portion and clears the monitor information #2 of the CPU 2 (Step 419), after writing the data to the data portion 71 of the DPM 7a completes (Step 418). Then, the CPU 2 reads the operation information #1 from the monitor information memory portion 71 and, when data of this information #1 is different from data of the preceding operation information #1a stored in the RAM 4, that is, when #1 is A and #1a is B or when #1 is B and #1a is A, determines the CPU 11a as normal and reads data on the data portion 71. Upon completion of this data read, the CPU 2 makes the monitor information #2 of the monitor information memory portion 72 as flag 1 (Step 315), enabling data write from the CPU 11a to the data portion 71. When there is an abnormal operation of the CPU 11a occurred in a line 7 (FIG. 5(a)), the operation step is shifted to abnormal operations 1 to 3 in FIGS. 5(b) to 5(d).
In FIG. 5(b), when the operation information #1 of data X is written in the monitor information memory portion 72 due to abnormal operation of the CPU 11a, the result of comparison performed in the Step 313 by the CPU 2 with respect to the preceding operation information #1a prior to the data read (Step 314) from the DPM 7a becomes NG. The CPU 2 repeats the comparison of the current operation information #1 with the preceding operation information #1a continuously (Step 318) and, when at least two NGs result from the continuous comparison operation (YES in Step 318), it is determined as an abnormality of operation of the CPU 11a. Therefore, the CPU 2 does not perform data read from the data portion 71.
Referring to FIG. 5(c), when no data of the operation information #1 is written in the monitor information memory portion 72 in an abnormal operation of the CPU 11a, the previous data B is kept in the monitor information memory portion 72. In this case, the Step 313 results in NG since the operation information #1a in the RAM 4 connected to the CPU 2 is also data B and, therefore, the Step 318 also results in YES. This state is similar to that shown in FIG. 5(b) and thus an abnormal operation of the CPU 11a is detected.
Referring to FIG. 5(d), the same operation information #1 of data B as the previous information is written in the monitor information memory portion 72 again upon the abnormal operation of the CPU 11a. In this case, however, the CPU 11a writes the operation information #1 of the monitor information memory portion 72 in the RAM 10a (Step 420) and, therefore, the processing of the CPU 2 and the CPU 11a are recovered to normal (Steps 419, 315) with only the data collected once by the CPU 11a in the line 32 being discarded.
Since, as mentioned above, the CPU 2 and the CPU 11a execute the data write and read operations with respect to the DPM 7a after they confirm whether or not the operation and monitor information #1 and 190 2 in the monitor information memory portion 72 are correct, any data input to or output from the data portion 71 is not performed unless the CPU 2 and the CPU 11a operate normally and therefore there is no inconsistency of data between the CPU 2 and the CPU 11a. It is clear that the above-mentioned relation is also established between the CPU 2 and any of the sub-CPU circuits of the multiprocessor system since the CPU 2 knows operating conditions of these sub-CPU circuits.
Further, as mentioned above, in this multiprocessor system, only the host-CPU 2 requires the watch-dog timer 1 for resetting an operational abnormality thereof and the sub-CPUs such as CPUs 11a and 11b, etc., do not require watch-dog timers since they are reset by the CPU 2 when their operation become abnormal. Therefore, it is possible to restrict the number of watch-dog timers required in this system to one.
Although the present invention has been described with reference to the specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments as well as other embodiments of the present invention, will become apparent to persons skilled in the art upon reference to the description of the present invention. It is therefore contemplated that the appended claims will cover any modifications or embodiments as fall within the true scope of the present invention.
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A multiprocessor system including dual port memories (DPMs), each DPM used as a shared memory circuit for a host CPU circuit and one of sub CPU circuits. Each sub CPU writes an operation information thereof in a monitor information memory portion of an associated DPM after data write to a data portion of the DPM every data collection. The host CPU references the operation information in the monitor information memory portion and reads data from the DPM after a normal operation of the sub CPU is confirmed. When the sub CPU operates abnormally, the host CPU resets the sub CPU operating normally. A watch-dog timer monitors only operation of the host CPU.
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FIELD
[0001] The present invention relates to shower recesses, in particular to a shower recess, shower tap and method of constructing a shower recess.
BACKGROUND
[0002] It is a well-known problem in the design of many shower recesses that the taps for controlling water flow are accessible only by reaching through an area where the water will impinge on the skin, and it can become impossible to adjust the water temperature after the taps are turned on without suffering scalding or discomfort.
[0003] There is a need to provide an improved shower recess which does not suffer from this problem, and yet it is economical to manufacture and install and simple in construction.
SUMMARY OF THE INVENTION
[0004] In accordance with a first broad aspect of the invention, there is provided a shower recess comprising:
[0005] a shower outlet for showering a person;
[0006] a partition attached at least to a wall for keeping water within the shower recess;
[0007] a shower tap installed on the wall for regulating at least the flow of water through the shower outlet;
[0008] wherein the shower tap is positioned substantially in line with the partition and within an opening in the partition shaped to accommodate the shower tap, and the shower tap comprises a handle on the shower recess side of the partition for operation when the person is inside the recess and a handle on the outer side of the partition for operation when the person is outside the recess.
[0009] In one embodiment, the shower tap is a mixer tap comprising a replaceable mixer tap cartridge operated through a spigot adapted to move in two directions to provide control over both flow and mixture of water, with each handle mechanically interconnected to the spigot so as to actuate movement in both directions. The mixer tap and mixer tap cartridge may be arranged so that rotation of the spigot about a horizontal axis substantially in line with the partition provides control over mixture and tilting of the spigot provides control over flow. The handles and mixer tap cartridge may be positioned and connected so that a substantially horizontal position of each handle of the horizontal axis movement corresponds to a midway position of mixture, and movement of each handle towards or away from the wall controls flow. The mixer tap cartridge may be oriented so that the spigot tilts about an axis which at the midway position of mixture is substantially vertical.
[0010] In one embodiment, the shower tap comprises a handle-to-spigot adapter shaped and sized at an end face thereof to be secured over the spigot and with handle receiving screw holes on mutually opposite sides of the adapter for receiving each handle.
[0011] In one embodiment, the shower tap comprises a tap frame adapted to be secured to a plumbing wall fixture and to extend into the partition opening and having a frame border shaped and sized to receive an edge of the partition bordering on the opening.
[0012] In one embodiment, the shower tap comprises a rotating part having handle receiving slots on opposed sides thereof, the rotating part being arranged so as to rotate when the handles are rotated about a horizontal axis and the slots being arranged to allow movement of the handles towards or away from the wall.
[0013] In one embodiment, the shower tap comprises shower recess side and outer side covers shaped and sized so as to attached to the frame and secure the rotating part and cover in the opening.
[0014] In one embodiment, the opening and tap frame has sufficient space such that the rotating part can be removed to allow removal and replacement of the mixer cartridge once the handles are screwed out and the covers are removed.
[0015] In one embodiment, the partition is a glass partition. In one embodiment, the glass partition is fixed to the wall by a metal strip.
[0016] In accordance with a second broad aspect of the invention, there is provided a shower tap as described in the first broad aspect of the invention and embodiments there described.
[0017] In accordance with a third broad aspect of the invention, there is provided a method of providing the shower recess of the first broad aspect of the invention, the method comprising the steps of:
[0018] providing and installing the shower outlet;
[0019] providing and installing the shower tap in said position; and
[0020] providing and installing the partition.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a depiction of a shower recess in accordance with an embodiment of the invention;
[0022] FIG. 2 is a close-up view of an installed shower tap of the shower recess of FIG. 1 ;
[0023] FIG. 3 is an exploded view of the shower tap of FIG. 2 showing the component parts.
DETAILED DESCRIPTION OF EMBODIMENTS
[0024] An embodiment of the current invention will now be described.
[0025] Referring first to FIG. 1 , the shower recess of this embodiment is installed in a corner of a tiled bathroom, with fixed glass partitions 1 and 2 protecting the rest of bathroom from splashes, and a shower rose attachment 3 positioned on wall 4 inside the shower recess with pipes and plumbing hidden behind the wall 4 , as is conventionally known in the art. A shower tap 6 is positioned not wholly inside the shower recess as is standard, but is positioned on wall 4 substantially in line with glass partition 2 , and has two control handles, one accessible from the shower recess side of the partition 2 and the other handle accessible from the outer side of the partition 2 .
[0026] Referring now to FIG. 2 , a close-up view of the installed shower tap 6 from the outer side of partition 2 is provided. Glass partition 2 is fixed to the wall 4 by metal securing strip 5 above and below the tap and has a suitably sized and positioned opening cut during manufacture or on-site to accommodate the tap. Visible when installed is a first outer cover integral with border 10 a , outer cover portions 12 a , 13 a and 11 a , accommodating outer rotating part 30 in the general shape of a cylinder. Rotating part 30 comprises a slot 31 a and plastic cover 21 a slides behind the slot under lateral movement of handle 20 a which projects through a hole in the slot into an internal mechanical interconnection to be described below. A corresponding second outer cover 10 b , handle 20 b etc is provided on the shower recess side of partition 2 and is not visible in this FIG. 2 .
[0027] Referring now to FIG. 3 , an exploded view of components of shower tap 6 is shown. A base point of fixture for tap 6 is a plumbing wall fixture in the form of “breech” and cartridge housing 50 , which contains within terminations of hot and cold pipes with O-ring seals for engagement and sealing with mixer cartridge 60 , and a mixed water outlet connected to a pipe leading to shower rose 3 . The breech and cartridge housing 50 is positioned by the plumber along a planned line of attachment of the glass partition 2 , the attachment of the partition 2 being provided by metal attachment strip 5 shown in FIG. 2 . The breech and housing 50 is similar to those known in the art, except that the terminations of pipes and correspondingly the mixer cartridge 60 are rotated through 90° from the normal orientation so as to accommodate a standard mixer cartridge 60 with spigot 62 that is normally used in a conventional shower tap. A conventional shower tap is normally installed so that a tilting axis of the spigot 62 is horizontal when the spigot is rotated to a midpoint of the mixing control, allowing for tap handles with a lifting movement to actuate the flow control. In application to the invention, by contrast, the standard mixer cartridge is in the above-mentioned 90 degree rotated orientation so that the two handles 20 a and 20 b are substantially horizontal when the spigot 62 is rotated to the midpoint of the mixing control, and a left-right movement of the handles actuates the flow control. Handles 20 a and 20 b are mechanically connected to spigot 62 via handle-to-spigot adapter 70 which comprises mutually opposite screw holes 71 a and 71 b ( 71 b not shown).
[0028] Fixed to breech and mixer housing 50 , by screws through screw holes such as 44 , is a frame which extends to the opening cut into the partition 2 and comprises a frame border 40 shaped and sized to receive an edge of the partition bordering on the opening. Outer cover borders 10 a and 10 b are shaped to hook over the frame 40 at a top edge and attach via grub screws from below into grub screw receiving plates 42 and 43 on the frame. Sealing strips 51 and 52 are secured on an inside edge of frame border 40 so as to engage outer rotating part 30 at a top and bottom thereof when installed in the gap 14 a,b defined in the cover. Sealing strips 51 and 52 help to provide resistance to water leakage from the shower recess side, as do O-ring seals 26 and 27 . Sliding slot cover securing rings 22 and 23 are provided to be inserted inside outer rotating part 30 so as to hold sliding slot covers 21 a and 21 b in position at either end thereof while allowing sliding through recesses 24 a,b and 25 a,b.
[0029] Assembly of the relevant parts of the shower recess proceeds is as follows. First, plumbing wall fixture 50 is installed with associated pipework behind wall 4 , and the frame is fitted thereon with screws through screw holes such as 44 . Glass partition 2 with appropriately sized opening can now be positioned and received at an edge of the opening into the frame border 40 . It will be appreciated that frame border 40 can be designed to be very wide so as to allow substantial mismatch between the opening cut into the glass partition 2 and the tap. Mixer cartridge 60 is now inserted into the breech and cartridge housing 50 and secured by screwing in mixer cartridge securing ring 61 , causing engagement with O-ring seals of the water pipe terminations at the back of the breech and cartridge housing 50 . Handle-to-spigot adapter 70 is now secured on to spigot 62 of mixer cartridge 60 with a grub screw. Outer rotating part 30 is assembled with O-ring seals 26 and 27 , sliding slot covers 21 a and 21 b , and sliding slot cover securing rings 22 and 23 . Upper and lower sealing strips 51 and 52 already being positioned on the inner edges of the frame border 40 , the outer rotating part assembly is able to be manoeuvred into the opening over adapter 70 and housing 50 . The first and second outer covers can now be positioned over the frame border 40 and encompassing rotating part 30 in the gaps 14 a,b , securing rotating part 30 in place within the gaps 14 a,b by engaging with tracks at either end of rotating part 30 . The first and second outer covers are secured with two grub screws each into grub screw receiving plates 42 and 43 . The first and second outer covers also have further grub screw holes (not shown), which are left empty on the shower recess side to allow drainage of any internal water back into the shower recess and which are installed with grub screws on the outer side to prevent water leakage on that side. Finally, handles 20 a and 20 b are screwed into handle receiving screw holes 71 a and 71 b . Disassembly is the reverse process. As will be appreciated, one advantage of this embodiment is that the tap can be disassembled and be mixer cartridge can be changed without disturbing the glass partition 2 .
[0030] In use, either handle 20 a operated from outside the shower recess, or handle 20 b operated from within the shower recess, may be rotated about a horizontal axis to control mixing, and may be moved in an orthogonal direction towards or away from the wall to control water flow. The operation of this embodiment is particularly intuitive because from both outside the recess and inside the recess, water flow is turned on by a movement to the right of the respective handle.
[0031] Persons skilled in the art will also appreciate that many variations may be made to the invention without departing from the scope of the invention, which is determined from the broadest scope and claims.
[0032] For example, while the embodiment shown relates to mixer taps, in its broadest aspect the invention extends to embodiments which have separate hot and cold controls, which may be housed in a single tap assembly within one opening in the partition, or alternatively may be housed in completely separate taps within separate vertically separated openings in the partition. In the simplest of such embodiments, the operation of each handle of the hot or cold tap will be rotation about a horizontal axis perpendicular to the wall to control the flow.
[0033] Further, while the embodiment shown relates to glass partitions, partitions constructed from other materials or more substantial walls are within the broadest scope of the invention.
[0034] Further, while the embodiment shown provides a particular mechanical interconnection which is an elegant and slight adaptation of conventional mixer shower tap operation, more complicated mechanical interconnections that provide different directions of movement are within the broadest scope of the invention.
[0035] Further still, as discussed above while the embodiment shown comprises a relatively thin frame border, broader frame borders and associated covers are within the scope of the invention that will allow different cover shapes, such as a half-circle, as may be attractive and as may accommodate different shaped openings.
[0036] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. Further, any method steps recited in the claims are not necessarily intended to be performed temporally in the sequence written, or to be performed without pause once started, unless the context requires it.
[0037] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.
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The invention provides a shower recess comprising: a shower outlet ( 3 ) for showering a person; a partition ( 2 ) attached at least to a wall ( 4 ) for keeping water within the shower recess; a shower tap ( 6 ) installed on the wall ( 4 ) for regulating at least the flow of water through the shower outlet; wherein the shower tap ( 6 ) is positioned substantially in line with the partition ( 2 ) and within an opening in the partition shaped to accommodate the shower tap ( 6 ), and the shower tap ( 6 ) comprises a handle ( 20 b ) on the shower recess side of the partition for operation when the person is inside the recess and a handle ( 20 a ) on the outer side of the partition for operation when the person is outside the recess.
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BACKGROUND OF INVENTION
[0001] The Sportsboard Hanger invention generally relates to a device for mounting, displaying and storing of recreational equipment on walls or from ceilings. The Sportsboard Hanger invention is an improved hanging device for surfboards, skis, snowboards, wake-boards, skim-boards, skateboards, boogie boards, sailboards, and wake surfboards than is now available on the market.
DESCRIPTION OF THE PRIOR ART
[0002] The sportsboard industry is comprised of a variety of sportsboard recreational equipment such as surfboards, skis, snowboards, wake-boards, skim-boards, skateboards, boogie boards, sailboards, and wake surfboards. Many sportsboard owners merely place their sportsboard against a wall of a garage, a corner of a room or on the floor against a wall during non-use of their sportsboard, while other sportsboard owners have utilized various mechanical devices for storage and/or display of their sportsboard vertically or horizontally on walls or from ceilings. Improper storage of sportsboards recreational equipment results in damage such as dents, scratches and cracks. Additionally, improperly stored sportsboard recreational equipment can cause serious injury if it falls from its storage point.
[0003] Many sportsboard recreational equipment manufacturers and owners prefer to display their sportsboards by having them mounted on a wall or ceiling in such a way that the owner or prospective buyer can best store, view, inspect and admire the sportsboard. Therefore, a device that offers ease of installation and access as well as safety from personal injury and protection of the sportsboard is essential, while also providing proper storage and display at a low cost.
SUMMARY OF THE INVENTION
[0004] This invention, a sportsboard hanger, provides for a far easier installation than that offered by other hanging devices currently on the market. The sportsboard hanger is comprised of two individual hanging devices of sewn woven loops of webbed fabric (various types), ¾ to 3 inches wide, each connected to a self-contained hooking device such as a hook/eye swivel or non-swivel attaching device. The two sewn loops, used in pairs, with attached hooking devices are then connected to an eye/hook screw or other device for suitable attachment to a ceiling or wall structure. This will allow for a hanging installation in a level linear fashion so that the sportsboard can be stored, displayed, or hung at an attractive oblique angle, if desired.
[0005] The structure, operation, advantages of the present invention will be set forth in the description, which follows, as well as the figures provided herin.
BRIEF DESCRIPTION OF THE DRAWING
[0006] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate various embodiments of the invention and, together with the general description given above and the detailed description of the embodiments given below, serve to enable the accurate use of the invention.
[0007] FIG. 1 illustrates a sportsboard-hanging device, according to one embodiment of the invention.
[0008] FIG. 2 illustrates a close-up of the sportsboard-hanging device with the inserted tri-glide device, for adjusting circumference or length of the fabric used in the sportsboard-hanger, for proper storage or display, according to one embodiment of the invention.
[0009] FIG. 3 illustrates an enlargement of an upper attachment device, which may or may not swivel 360 degrees, as one embodiment of the invention.
[0010] FIG. 4 illustrates an enlargement of the adjustable sliding mechanism, the tri-glide device that enables shortening or lengthening the circumference of the woven fabric used in the sportsboard-hanger, as one embodiment of the invention.
[0011] FIG. 5 illustrates an enlargement of the eye screw used as a fastener in a ceiling or wall structure, which connects to the hook device attached to the upper portion of the sportsboard-hanger as one embodiment of the invention.
[0012] FIG. 6 illustrates the sportsboard-hanging device used for a surfboard or other sportsboard display, according to one embodiment of the invention.
[0013] FIG. 7 illustrates the sportsboard-hanging device used for multiple sportsboard displays, such as snow skis, according to one embodiment of the invention.
[0014] FIG. 8 illustrates the sportsboard hanging device used with a monogrammed logo or design sewn on or printed onto the strap fabric, according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Reference will now be made in detail to the various embodiments of the invention as illustrated in the accompanying drawings.
[0016] In accordance with the present invention, there is provided in one embodiment of the invention, a sportsboard-hanging device, comprised of one or more elements, for hanging a sportsboard such as a surfboard, skis, snowboard, wake-board, skim-board, skateboard, boogie board, sailboard, and/or wake surfboard.
[0017] The drawing of FIG. 1 , reveals one sportsboard hanger, used in pairs, for wall or ceiling mountable sportsboard hanging devices as the present invention.
[0018] The sportsboard hanger in FIG. 1 , the upper attachment device shown and referenced by Character 1 , indicates a swivel or non-swivel hook/eye device used to secure the sportsboard hanger to another hook/eye screw attached to a wall or ceiling structure.
[0019] The sportsboard hanger in FIG. 1 , the area indicated and referenced by Character 2 , indicates the portion of the strap fabric, where it is machine-sewn at the end of the strap fabric, thus capturing the hook/eye attachment at the top of the sportsboard hanger device.
[0020] The sportsboard hanger in FIG. 1 , the tri-glide adjustable device indicated and referenced by Character 3 , generally identifies the location of the tri-glide device for the purpose of lengthening and shortening the strap fabric, so that the desired length is acquired for proper display or storage of a sportsboard. The strap of woven nylon fabric or other suitable fabric is indicated generally by reference to Character 4 .
[0021] The sportsboard hanger In FIG. 1 , illustrates the ability of the sportsboard hanger to hold two sportsboards simultaneously, and is referenced by Character 5 , illustrating the use of the adjustable mechanism of the tri-glide by adjusting a single hanger device creating two loops on a single hanger. Additionally, shortening or lengthening the length of one sportsboard hanger creates a level display when necessary. Although sportsboard hangers are always used in pairs the other hanging device would be construed in the same manner, thus providing support for two sportsboards stored or displayed, level and horizontally from a wall or ceiling. See FIGS. 6 & 7 for illustrations of a surfboard and of snow skis.
[0022] The sportsboard hanger as shown in FIG. 2 , and referenced by character 6 , represents a detailed view of the upper attachment device, including the location of the tri-glide adjustable device for lengthening and shortening the strap fabric. Additionally illustrated is the manner in which the upper hooking/eye attachment is sewn into the end of the strap fabric, thus capturing the hook/eye attachment at the top of the sportsboard hanging device.
[0023] The hooking device as shown in FIG. 3 , and referenced by Character 7 , represents a detailed view of a hooking device with capabilities of swiveling 360 degrees or non-swiveling.
[0024] The tri-glide device as shown in FIG. 4 , and referenced by the character 8 , represents a detailed view of a tri-glide device, which enables the sportsboard hanger to become adjustable to various lengths, for the purpose of leveling the sportsboard due to a sloped ceiling or for supporting two sportsboards as described in FIGS. 6 & 7 . The tri-glide will allow for a hanging installation in a level linear fashion so that the sportsboard can be stored, displayed, or hung at an attractive oblique angle, if desired.
[0025] The eye screw device as shown in FIG. 5 , and referenced by Character 9 , represents a detailed view of a eye screw device which is utilized in a wall or ceiling structure for proper secure attachment for the sportsboard hanger.
[0026] The sportsboard hanger in FIG. 8 , and referenced by Character 10 , represents the implementation of monogram or printed designs/logos onto the sportsboard hanger. This fabric is available in various sizes from ¾″ to 3″. The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive. All changes, which come within the meaning and range of equivalency of the claims, are intended to be embraced therein.
BACKGROUND OF INVENTION
[0027] The Sportsboard Hanger invention generally relates to a device for mounting, displaying and storing of recreational equipment on walls or from ceilings. The Sportsboard Hanger invention is an improved hanging device for surfboards, skis, snowboards, wake-boards, skim-boards, skateboards, boogie boards, sailboards, and wake surfboards than is now available on the market.
DESCRIPTION OF THE PRIOR ART
[0028] The sportsboard industry is comprised of a variety of sportsboard recreational equipment such as surfboards, skis, snowboards, wake-boards, skim-boards, skateboards, boogie boards, sailboards, and wake surfboards. Many sportsboard owners merely place their sportsboard against a wall of a garage, a corner of a room or on the floor against a wall during non-use of their sportsboard, while other sportsboard owners have utilized various mechanical devices for storage and/or display of their sportsboard vertically or horizontally on walls or from ceilings. Improper storage of sportsboards recreational equipment results in damage such as dents, scratches and cracks. Additionally, improperly stored sportsboard recreational equipment can cause serious injury if it falls from its storage point.
[0029] Many sportsboard recreational equipment manufacturers and owners prefer to display their sportsboards by having them mounted on a wall or ceiling in such a way that the owner or prospective buyer can best store, view, inspect and admire the sportsboard. Therefore, a device that offers ease of installation and access as well as safety from personal injury and protection of the sportsboard is essential, while also providing proper storage and display at a low cost.
SUMMARY OF THE INVENTION
[0030] This invention, a sportsboard hanger, provides for a far easier installation than that offered by other hanging devices currently on the market. The sportsboard hanger is comprised of two individual hanging devices of sewn woven loops of webbed fabric (various types), ¾ to 3 inches wide, each connected to a self-contained hooking device such as a hook/eye swivel or non-swivel attaching device. The two sewn loops, used in pairs, with attached hooking devices are then connected to an eye/hook screw or other device for suitable attachment to a ceiling or wall structure. This will allow for a hanging installation in a level linear fashion so that the sportsboard can be stored, displayed, or hung at an attractive oblique angle, if desired.
[0031] The structure, operation, advantages of the present invention will be set forth in the description, which follows, as well as the figures provided herin.
BRIEF DESCRIPTION OF THE DRAWING
[0032] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate various embodiments of the invention and, together with the general description given above and the detailed description of the embodiments given below, serve to enable the accurate use of the invention.
[0033] FIG. 1 illustrates a sportsboard-hanging device, according to one embodiment of the invention.
[0034] FIG. 2 illustrates a close-up of the sportsboard-hanging device with the inserted tri-glide device, for adjusting circumference or length of the fabric used in the sportsboard-hanger, for proper storage or display, according to one embodiment of the invention.
[0035] FIG. 3 illustrates an enlargement of an upper attachment device, which may or may not swivel 360 degrees, as one embodiment of the invention.
[0036] FIG. 4 illustrates an enlargement of the adjustable sliding mechanism, the tri-glide device that enables shortening or lengthening the circumference of the woven fabric used in the sportsboard-hanger, as one embodiment of the invention.
[0037] FIG. 5 illustrates an enlargement of the eye screw used as a fastener in a ceiling or wall structure, which connects to the hook device attached to the upper portion of the sportsboard-hanger as one embodiment of the invention.
[0038] FIG. 6 illustrates the sportsboard-hanging device used for a surfboard or other sportsboard display, according to one embodiment of the invention.
[0039] FIG. 7 illustrates the sportsboard-hanging device used for multiple sportsboard displays, such as snow skis, according to one embodiment of the invention.
[0040] FIG. 8 illustrates the sportsboard hanging device used with a monogrammed logo or design sewn on or printed onto the strap fabric, according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Reference will now be made in detail to the various embodiments of the invention as illustrated in the accompanying drawings.
[0042] In accordance with the present invention, there is provided in one embodiment of the invention, a sportsboard-hanging device, comprised of one or more elements, for hanging a sportsboard such as a surfboard, skis, snowboard, wake-board, skim-board, skateboard, boogie board, sailboard, and/or wake surfboard.
[0043] The drawing of FIG. 1 , reveals one sportsboard hanger, used in pairs, for wall or ceiling mountable sportsboard hanging devices as the present invention.
[0044] The sportsboard hanger in FIG. 1 , the upper attachment device shown and referenced by Character 1 , indicates a swivel or non-swivel hook/eye device used to secure the sportsboard hanger to another hook/eye screw attached to a wall or ceiling structure.
[0045] The sportsboard hanger in FIG. 1 , the area indicated and referenced by Character 2 , indicates the portion of the strap fabric, where it is machine-sewn at the end of the strap fabric, thus capturing the hook/eye attachment at the top of the sportsboard hanger device.
[0046] The sportsboard hanger in FIG. 1 , the tri-glide adjustable device indicated and referenced by Character 3 , generally identifies the location of the tri-glide device for the purpose of lengthening and shortening the strap fabric, so that the desired length is acquired for proper display or storage of a sportsboard. The strap of woven nylon fabric or other suitable fabric is indicated generally by reference to Character 4 .
[0047] The sportsboard hanger In FIG. 1 , illustrates the ability of the sportsboard hanger to hold two sportsboards simultaneously, and is referenced by Character 5 , illustrating the use of the adjustable mechanism of the tri-glide by adjusting a single hanger device creating two loops on a single hanger. Additionally, shortening or lengthening the length of one sportsboard hanger creates a level display when necessary. Although sportsboard hangers are always used in pairs the other hanging device would be construed in the same manner, thus providing support for two sportsboards stored or displayed, level and horizontally from a wall or ceiling. See FIGS. 6 & 7 for illustrations of a surfboard and of snow skis.
[0048] The sportsboard hanger as shown in FIG. 2 , and referenced by character 6 , represents a detailed view of the upper attachment device, including the location of the tri-glide adjustable device for lengthening and shortening the strap fabric. Additionally illustrated is the manner in which the upper hooking/eye attachment is sewn into the end of the strap fabric, thus capturing the hook/eye attachment at the top of the sportsboard hanging device.
[0049] The hooking device as shown in FIG. 3 , and referenced by Character 7 , represents a detailed view of a hooking device with capabilities of swiveling 360 degrees or non-swiveling.
[0050] The tri-glide device as shown in FIG. 4 , and referenced by the character 8 , represents a detailed view of a tri-glide device, which enables the sportsboard hanger to become adjustable to various lengths, for the purpose of leveling the sportsboard due to a sloped ceiling or for supporting two sportsboards as described in FIGS. 6 & 7 . The tri-glide will allow for a hanging installation in a level linear fashion so that the sportsboard can be stored, displayed, or hung at an attractive oblique angle, if desired.
[0051] The eye screw device as shown in FIG. 5 , and referenced by Character 9 , represents a detailed view of a eye screw device which is utilized in a wall or ceiling structure for proper secure attachment for the sportsboard hanger.
[0052] The sportsboard hanger in FIG. 8 , and referenced by Character 10 , represents the implementation of monogram or printed designs/logos onto the sportsboard hanger. This fabric is available in various sizes from ¾″ to 3″. The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive. All changes, which come within the meaning and range of equivalency of the claims, are intended to be embraced therein.
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A sportsboard hanger comprised of a loop-harness apparatus, used in pairs, for storing and displaying sportsboard-based recreational equipment used in the sportsboard industry. This sportsboard hanger invention provides a space-saving advantage at an economical cost, since the primary material is constructed of flexible strap material such as woven-nylon fabric. The sportsboard hanger incorporates an adjustable harness, which has a hooking or eye device sewn into the fabric at the attaching end of the sportsboard hanger. It is then hooked onto an eye or hook screw fastener inserted into the wall or ceiling structure for storage or display of any of the following objects in the sportsboard industry: surfboards, skis, snowboards, wake-boards, skim-boards, skateboards, sailboards, and wake surfboards.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present invention is related to the subject matter of U.S. patent application Ser. No. 10/922,029.
FIELD OF THE INVENTION
[0002] The present invention is directed generally at drilling blowout preventers used in drilling oil and gas wells, and specifically to a rotating pressure control device for use in both under-balanced drilling applications and managed pressure drilling applications.
BACKGROUND OF THE INVENTION
[0003] When the hydrostatic weight of the column of mud in a well bore is less than the formation pressure, the potential for a blowout exists. A blowout occurs when the formation expels hydrocarbons into the well bore. The expulsion of hydrocarbons into the well bore dramatically increases the pressure within a section of the well bore. The increase in pressure sends a pressure wave up the well bore to the surface. The pressure wave can damage the equipment that maintains the pressure within the well bore. In addition to the pressure wave, the hydrocarbons travel up the well bore because the hydrocarbons are less dense than the mud. If the hydrocarbons reach the surface and exit the well bore through the damaged surface equipment, there is a high probability that the hydrocarbons will be ignited by the drilling or production equipment operating at the surface. The ignition of the hydrocarbons produces an explosion and/or fire that is dangerous for the drilling operators. In order to minimize the risk of blowouts, drilling rigs are required to employ a plurality of different pressure control devices, such as an annular pressure control device, a pipe ram pressure control device, and a blind ram pressure control device. If a “closed loop drilling” method is used, then a rotating pressure control device will be added on top of the conventional pressure control stack. Persons of ordinary skill in the art are aware of other types of pressure control devices. The various pressure control devices are positioned on top of one another, along with any other necessary surface connections, such as the choke and kill lines for managed pressure drilling applications and nitrogen injection lines for under balanced drilling applications. The stack of pressure control devices and surface connections is called the pressure control stack.
[0004] One of the devices in the pressure control stack can be a rotating pressure control device also referred to as a rotating pressure control head. The rotating pressure control head is located at the top of the pressure control stack and is part of the pressure boundary between the well bore pressure and atmospheric pressure. The rotating pressure control head creates the pressure boundary by employing a ring-shaped rubber or urethane sealing element that squeezes against the drill pipe, tubing, casing, or other cylindrical members (hereinafter, drill pipe). The sealing element allows the drill pipe to be inserted into and removed from the well bore while maintaining the pressure differential between the well bore pressure and atmospheric pressure. The sealing element may be shaped such that the sealing element uses the well bore pressure to squeeze the drill pipe or other cylindrical member. However, some rotating pressure control heads utilize some type of mechanism, typically hydraulic fluid, to apply additional pressure to the outside of the sealing element. The additional pressure on the sealing element allows the rotating pressure control head to be used for higher well bore pressures.
[0005] The sealing element on all rotating pressure control heads eventually wear out because of friction caused by the rotation and/or reciprocation of the drill pipe. Additionally, the passage of pipe joints, down hole tools, and drill bits through the rotating pressure control head causes the sealing element to expand and contract repeatedly, which also causes the sealing element to become worn. Other factors may also cause wear of the sealing element, such as extreme temperatures, dirt and debris, and rough handling. When the sealing element becomes sufficiently worn, it must be replaced. If a worn sealing element is not replaced, it may rupture, causing a loss of hydraulic fluids and control over the well head pressure.
[0006] Currently, visual inspections or time based life span estimates are used to determine when to replace a worn sealing element. Visual inspections are subjective, and may be unreliable. Time based estimates may not take into account actual operating conditions, and be either too short or too long for a particular situation. If the time based estimate is too conservative, then sealing elements are replaced too frequently, causing unnecessary expense and delay. If the time based estimate is too aggressive, then the risk for rupture may be unacceptable.
[0007] U.S. patent application Ser. No. 10/922,029 (the '029 application) discloses a Rotating Pressure Control Head (RPCH) having a sealing element in an inner housing where the inner housing is rotatably engaged to an outer housing by an upper bearing and a lower bearing. The RPCH of the '029 application offers many improvements over the prior art including a shorter stack size, a quick release mechanism for inner unit change out, and a reduction in harmonic vibrations. Further improvements can be sought in ways to extend the life of the components. Wellbore fluid pressure, pressurized hydraulic fluid, and pipe friction against the sealing element exert a net upward or downward force on the inner housing that translates into a load on the upper and lower bearings. The load on the upper and lower bearings generates heat which is the most significant factor in bearing wear and life expectancy. A need exists for a way to balance the net force on the inner housing in order to reduce heat and wear on the bearings. Additionally, a need exists for an objective way to determine when a sealing element is sufficiently worn and needs to be replaced, without causing waste from early replacement, and without increasing the risk of rupture.
SUMMARY OF THE INVENTION
[0008] A Rotating Pressure Control Device (RPCD) uses pressure balancing so that a force transmitted through the bearings from an inner housing to an outer housing is balanced, thereby increasing the service life of the bearings.
[0009] The RPCD comprises an upper body and a lower body that form an outer housing. An inner housing rotates with respect to the outer housing. The inner housing has a sealing element that constricts around the drill pipe, and bearings are placed between the inner housing and outer housing to allow rotation of the inner housing within the outer housing.
[0010] An upper dynamic rotary seal is located between the inner housing and the outer housing and above the sealing element. A middle dynamic rotary seal is located between the inner housing and the outer housing and below the sealing element. A lower dynamic rotary seal is located between the inner housing and the outer housing below the middle dynamic rotary seal.
[0011] An upper piston area is created between the inner housing and the outer housing by the upper dynamic rotary seal and the middle dynamic rotary seal. A lower piston area is created below the expanded sealing element between the outside of the drill pipe and the lower dynamic rotary seal.
[0012] Wellbore fluid pressure, pressurized hydraulic fluid, and pipe friction against the sealing element cause a net upward or downward force on the inner housing with respect to the outer housing. These net upward or downward forces cause wear to the bearings. By adjusting hydraulic fluid pressure in the upper piston area, users can adjust the amount of downward force exerted by the upper piston area to compensate for the upward force exerted by the lower piston area. In addition, such adjustments also compensate for forces caused by friction between the drill pipe and sealing element. The reduction in force on the inner housing achieved by pressure balancing results in reduced bearing heat and wear.
[0013] Additionally, the RPCD has an electrically conductive wear indicator integrated with the drill pipe sealing element. A conductive strip is embedded inside the sealing element. The conductive strip makes electrical contact with a first electrode of an electrical indicator. A second electrode of the electrical indicator is in electrical contact with the drill pipe. When the sealing element is worn down to a pre-determined depth, exposing the embedded conductive strip, a closed circuit is formed from the electrical indicator through the first electrode, the embedded conductive strip, the drill pipe, and the second electrode, causing a signal on an electrical indicator, alerting users of the RPCD that it is time to replace the sealing element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] 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 objectives 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:
[0015] FIG. 1 is a cross sectional view of the RPCD;
[0016] FIG. 2 is a cross sectional view of the RPCD with the sealing element in an expanded position;
[0017] FIG. 3 is a perspective view of the RPCD;
[0018] FIG. 4 is a cross sectional view of the RPCD with a wear indicator top plate;
[0019] FIG. 5 is a detail view of a conductive bolt;
[0020] FIG. 6 is detail view of a conductive pin; and
[0021] FIG. 7 is a cross sectional view of the RPCD with a closed circuit caused by a worn sealing element.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] FIG. 1 is a cross sectional view of pressure balanced rotating pressure control device 500 . Upper body 200 and lower body 100 form outer housing 150 . Inner housing 300 rotates inside outer housing 150 . Inner housing 300 contains sealing element 340 adapted to constrict around a drill pipe. Upper bearing 332 and lower bearing 334 affixed to inner housing 300 provide vertical and lateral support between inner housing 300 and outer housing 150 .
[0023] Input port 204 allows hydraulic fluid to enter outer housing 150 to reach channel 338 , cavity 330 , and spaces between inner housing 300 and outer housing 150 . Alternate input port 202 is capped with input plug 210 . Output port 208 allows hydraulic fluid to exit outer housing 150 . Alternate output port 206 is capped with output plug 212 . Wellbore fluid enters RPCD at input 102 and exits through output 104 .
[0024] Upper dynamic rotary seal 322 is located between inner housing 300 and outer housing 150 and above sealing element 340 and upper bearing 332 . Upper dynamic rotary seal 322 is shown here as two separate dynamic rotary seals.
[0025] Middle dynamic rotary seal 324 is located between the inner housing 300 and outer housing 150 , below sealing element 340 , and below lower bearing 334 . Middle dynamic rotary seal 324 has a wider diameter than upper dynamic rotary seal 322 .
[0026] Lower dynamic rotary seal 326 is located between the inner housing 300 and outer housing 150 below middle dynamic rotary seal 324 .
[0027] Vent port 106 allows open space between middle dynamic rotary seal 324 and lower dynamic rotary seal 326 to remain at atmospheric pressure. In addition, vent port 106 serves as a leak detection system because in the event that middle dynamic rotary seal 324 or lower dynamic rotary seal 326 begin to leak, fluid will drain from vent port 106 revealing the leak.
[0028] Pair of o-rings 312 sit between upper body 200 and lower body 100 . Upper sealing element o-ring (or upper alternate sealing element) 315 and lower sealing element o-ring (or lower alternate sealing element) 313 sit between sealing element 340 and inner body 300 .
[0029] FIG. 2 is a cross sectional view of pressure balanced rotating pressure control device 500 with sealing element 340 in an expanded position around drill pipe 400 .
[0030] Pressurized hydraulic fluid 440 enters outer housing 300 through input port 204 . Alternate input port 202 is capped with input plug 210 . Pressurized hydraulic fluid 440 expands sealing element 340 around drill pipe 400 . Hydraulic fluid 440 permeates the area between inner housing 300 and outer housing 150 between upper dynamic rotary seal 322 and middle dynamic rotary seal 324 . Hydraulic fluid 440 lubricates upper bearing 332 and lower bearing 334 . Pressurized hydraulic fluid 440 exits outer housing through output port 208 for recirculation. Alternate output port 206 is capped by output plug 212 .
[0031] Upper piston area 520 is defined by the equation A(up)=(π×(D(s) 2 −D(us) 2 )/4 where D(ms)=middle dynamic seal ring 324 outer diameter, and where D(us)=upper dynamic rotary seal 322 outer diameter. Hydraulic fluid 440 is induced into upper piston area 520 to expand sealing element 340 around drill pipe 400 , when hydraulic fluid 440 is so induced, it acts upon upper piston area 520 to create a downward force on inner housing 300 . Force on upper piston area 520 is defined by the equation F(up)=A(up)×P(h) where P(h)=induced hydraulic pressure. Pressurized hydraulic fluid 440 energizes upper piston area 520 exerting a downward force on inner housing 300 . Upper piston area 520 remains constant.
[0032] Lower piston area 510 is defined by the equation A(lp)=(π×(D(b) 2 −D(p) 2 )/4 where D(b)=the outer diameter of lower dynamic rotary seal 326 and where D(p)=the outer diameter of drill pipe 400 . Thus, a smaller diameter pipe results in a larger cross sectional area for lower piston area 510 . Pressurized wellbore fluid 410 acts upon lower piston area 510 to create an upward force on inner housing 300 . Force on lower piston area 510 is defined by the equation F(lp)=A(lp)×P(wb) where P(wb)=wellbore pressure. Wellbore fluid 410 exerts an upward force on inner housing 300 as it presses upward into lower piston area 510 . Lower piston area 510 does not remain constant and varies in size due to drill pipe diameter changes as the drill pipe is lowered, or raised, through RCPH 500 .
[0033] Vented area 345 is defined as an area between the outer diameter of middle dynamic rotary seal 324 and the outer diameter of lower dynamic rotary seal 326 . Vent port 106 allows vented area 345 to remain at atmospheric pressure. By keeping vented area 345 at atmospheric pressure, a pressure imbalance is created such that upper piston area 520 , when it is energized by pressurized hydraulic fluid 440 , creates a force opposite that of lower piston area 510 when it is energized by wellbore fluid 410 .
[0034] FIG. 3 is a perspective view of RPCH 500 showing upper piston area 520 and lower piston area 510 . Upper piston area 520 is an area between the outer diameter of middle dynamic seal ring 324 and the outer diameter of upper dynamic rotary seal 322 defined by the upper piston area formula set forth above. Lower piston area 510 is an the area between the outer diameter of lower dynamic seal element 326 and the outer diameter of drill pipe 400 defined by the lower piston area formula set forth above.
[0035] The upward and downward forces on inner housing 300 are also affected by the frictional drag of the pipe moving through the collapsed sealing element 340 , as described by the equation: F(f)=(π×D(p)×L)×P(h)×u where L=length of pipe 400 in contact with sealing element 340 , and where u=coefficient of drag between pipe 400 and sealing element 340 .
[0036] The sum of the total forces on inner housing 300 is calculated with the equation F(sum)=F(lp)−F(up)++/−F(f). The sign for the friction force F(f) depends on whether drill pipe 400 is moving upwards or downwards. If drill pipe 400 is moving upwards, F(f) is positive. If drill pipe 400 is moving downward, F(f) is negative. A positive F(sum) indicates a net upward force on inner housing 300 , the bearings and seals. A negative F(sum) indicates a net downward force on inner housing 300 , the bearings and seals.
[0037] Pressure balanced rotating pressure control device 500 allows drillers to use pressurized hydraulic fluid 440 to compensate for upward and downward forces on inner housing 300 . By compensating for differences in upward and downward forces on inner housing 300 , heat and/or wear on upper bearing 332 and lower bearing 334 will be reduced and the life of upper bearing 332 and lower bearing 334 will be expanded.
[0038] A wear indicator is used to signal when it is time to replace the drill pipe sealing element. FIG. 4 is a cross sectional elevation view of a wear indicator on pressure balanced RPCD 500 . Upper body 200 and lower body 100 form outer housing 150 . Inner housing 300 rotates inside outer housing 150 . Inner housing 300 contains sealing element 340 adapted to constrict around drill pipe 400 . Top plate 700 is attached to the top of RPCD 500 , which is electrically insulated from the top plate 700 .
[0039] Conductive strip 710 is embedded axially in sealing element 340 at a depth where, when worn down, sealing element 340 should be replaced. Conductive ring 720 contacts the top end of conductive strip 710 . Conductive strip 710 and conductive ring 720 are electrically isolated from inner housing 300 and other conductive surfaces by sealing element 340 .
[0040] Bolt 730 (described in FIG. 5 below) connects conductive ring 720 to first electrode 770 with brush 738 . First electrode 770 passes through top plate 700 . First electrode 770 leads to indicator 790 .
[0041] Second electrode 780 connects indicator 790 to pin 750 (described in FIG. 6 below). Pin 750 is located inside of top plate 700 . Spring 752 holds pin 750 against drill pipe 400 creating an electrical contact through conductor 758 .
[0042] FIG. 5 shows a cross-sectional detail of bolt 730 . Bolt 730 is a special insulated bolt having conductor 732 running axially through the center of bolt 730 which is electrically insulated from the body of the bolt 730 . Bolt conductor 732 extends below bolt 730 creating contact point 734 . Spring loaded electric brush 738 is located at top end 736 of bolt 730 . Spring loaded electric brush 738 is attached to bolt conductor 732 and is electrically isolated from the body of bolt 730 .
[0043] No alignment is required when installing sealing element 340 in RPCD 500 . Once sealing element 340 is installed inside inner housing 300 , bolt 370 is threaded through the upper portion of inner housing 300 , driving the contact point 734 into sealing element 340 . The location of bolt 730 is such that the contact point 734 will pierce conductive ring 720 establishing an electric circuit from conductive strip 710 in sealing element 340 , through conductive ring 720 and into bolt 730 . Note that bolt 730 rotates with inner housing 300 as drill pipe 400 is turned.
[0044] Commutator ring 772 on top plate 700 is aligned such that spring loaded electric brush 738 remains in contact with commutator ring 772 as inner housing 300 rotates with turning drill pipe 400 . Thus, an insulated electrical conductor path is established from conductive strip 710 in sealing element 340 , through conductive ring 720 , through bolt conductor 732 in bolt 730 , through spring loaded electric brush 738 , through commutator ring 772 , and out first electrode 770 .
[0045] FIG. 6 shows a detail of pin 750 mounted inside top plate 700 . Pin 750 is spring loaded inside top plate 700 , through outer aperture 702 and inner aperture 704 . Spring 752 exerts force between top plate 700 and rib 756 on pin 750 . Pin conductor 754 passes through pin 750 connecting pipe contactor 758 to second electrode 780 . Pin 750 is electrically insulated from top plate 700 .
[0046] Pin 750 is retracted as drill pipe 400 is lowered through RPCH 500 and is then allowed to spring against drill pipe 400 . Spring 752 keeps pipe contactor 758 in contact with drill pipe 400 as tool joints and other such changes in drill pipe 400 outside diameter pass through RPCH 500 . Thus, an electrical circuit is established from drill pipe 400 , through pipe contactor 758 , through pin conductor 754 inside pin 750 , and out through second electrode 780 .
[0047] FIG. 7 is a cross sectional elevation view of pressure balanced rotating pressure control device 500 with a closed circuit caused by worn sealing element 340 . Whenever sealing element 340 wears down, exposing conductive strip 710 , drill pipe 400 makes physical and electrical contact with conductive strip 710 . A closed circuit is formed from indicator 790 through first electrode 770 , brush 738 , bolt 730 , conductive ring 720 , conductive strip 710 , drill pipe 400 , conductor 758 , pin 750 , and second electrode 780 , causing a reading on indicator 790 . The reading on indicator 790 after the circuit is closed alerts users of RPCD 500 that it is time to replace sealing element 340 .
[0048] Persons skilled in the art are aware that a normally closed circuit could also be employed. With a normally closed circuit, the electrically conductive path is in place at all times until wear of the sealing element causes conductive strip 710 to sever, opening the circuit and causing indicator 790 to alert users of RPCD 500 that it is time to replace sealing element 340 . In other words, during normal operation, an indicator light would be on, and when the circuit is broken, the indicator light would turn off.
[0049] With respect to the above description, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function, manner of operation, assembly, and use are deemed readily apparent and obvious to one of ordinary skill in the art. The present invention encompasses all equivalent relationships to those illustrated in the drawings and described in the specification. The novel spirit of the present invention is still embodied by reordering or deleting some of the steps contained in this disclosure. The spirit of the invention is not meant to be limited in any way except by proper construction of the following claims.
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Force balancing adjusts hydraulic fluid pressure in an upper piston area of a Rotating Pressure Control Device (RPCD) that has an inner housing rotatably engaged within an outer housing by an upper bearing and a lower bearing. The hydraulic fluid pressure is adjusted to balance net force in a upper piston area and a lower piston area. The fluid pressure adjustment creates a force differential that balances the total load transmitted through the upper bearing and the lower bearing and thereby extends the life of the sealing element and bearings. Additionally, a wear indicator signals the end of the useful life of the drill pipe sealing element.
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FIELD OF THE INVENTION
The present invention relates to a container, in particular a plastic ampule, having a neck part adjoining the container body and threadly receiving a first cap. A second cap part extends at least partially between the first cap part and the neck part and is provided with an opening device having at least one opening for opening the container body. The container body can be closed by the first cap part.
BACKGROUND OF THE INVENTION
DE 42 32 305 C1 discloses a cap for containers, especially bottles produced from plastic in a blow molding process and filled and sealed in the mold, also in ampule form. A neck on the container receives a cap. The neck is made integrally with a dropper. That patent specification describes as known solutions bottles of this type, with an externally threaded neck being closed on a free end by a closure part made integrally with the neck. A cap screwed onto the neck is provided inside with a centrally arranged mandrel to puncture the closure part. If after puncturing the closure part the cap is removed, the liquid present in the bottle can be discharged through the opening formed in the closure part. If the thread of the bottle neck and/or of the cap or the mandrel has not been optimally formed, it is possible that the opening punctured with the mandrel extends obliquely with respect to the longitudinal axis or that after removing a partial amount and subsequently screwing the cap on, a second opening is punctured. These situations may result in the liquid emerging at several locations in a direction deviating from the longitudinal axis and present a high degree of interference for the appropriate use of the solution. Accordingly, this patent solution proposes, due to the section of the cap made as a dropper, proportioning the dispensing of the liquid contents of the bottle, not by an opening formed by the bottle neck, but by the dropper of the cap to allow trouble-free use.
DE 195 80 104 T1 discloses a generic container solution with a container sealed airtight and provided with a cover cap. A mandrel attached in the cap is used to puncture a membrane on the neck part of the container. The hollow mandrel forms a type of top defining a discharge passage path to ensure controlled liquid removal. For this purpose the mandrel punctures the membrane and, after removing a first cap part, the mandrel is retained in the membrane by the second cap part to make available a controlled dispenser opening or delivery opening for the container. The first cap part can then be re-used to close the dispenser opening or delivery opening for the container body. The production of the known container solutions can be regarded at least to some extent as complicated, and therefore, costly.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved container with better practical handling with simultaneously facilitated production.
This object is basically achieved by a container whereby the process of screwing on the first cap part, the first cap part entrains the second cap part such that the opening device induces the opening of the container body. After unscrewing the first cap part, a closure part clears the opening of the opening device. The second cap part remains on the neck part. The dropper part formed by the second cap part can be positively connected to the neck part and fixed on it. The first cap part can be removed from the container body for clearing its opening, and in particular, can be unscrewed.
Depending on the respective application and the customer's specifications, two different opening versions can be implemented with only one container. The container according to the present invention has an open cap arrangement, i.e., the first cap part is only partially, for example, a half thread turn, screwed onto the assigned thread of the container body so that the user first of all must turn the first cap part farther down along the thread to then open the container body by the opening device usually in the form of a mandrel. In this connection, the second cap part remains on the neck part and the upper cap in the form of the first cap part can be turned in the opposite direction to the previous screwing direction to clear the opening for removing the stored medium from the container. On the other hand, the container can be delivered already opened, i.e., the first cap part is completely screwed on; the second cap part is fixed in a defined manner on the neck part; and the opening device (mandrel) has already pierced the container opening to clear its opening. The user of the container need now only unscrew or twist off the upper first cap part, in order to be able to use the container contents, for example, in the form of stored eye drops. Accordingly two different types of removal possibilities can be implemented with only one arrangement, in a manner specific to the customer.
As a result of the respective plausible application arrangement for the two application solutions, incorrect application is largely precluded. Even if the container solution according to the present invention optionally has more functional components, especially in the form of two cap parts, than the known solutions, the second cap part being an integral component of the first cap part and being overlapped by the latter in the uncleared positions for the opening, the container according to the present invention overall can be easily and economically produced. The container body can be produced especially within the framework of a blow-fill-seal process, as has become known in the trade under the trademark “Bottelpack®”. The cap parts are produced preferably in an injection molding process.
In one especially preferred embodiment of the container according to the present invention, driver elements of the first cap part which act on the second cap part induce an entraining motion. After the second cap part on the neck part engages, the fixing part is interlocked in the other direction of action and releases the first cap part as it is being unscrewed. This operation ensures reliable use. The axial distance of travel of the cap parts relative to one another are in any case dimensioned such that reliable locking of the second cap part to the container body takes place. The first cap part can then clear the container opening without hindrance. By preference, to interlock the second cap part on the neck part of the container body, it has an engagement region tapering by one step to the inside and being engaged by at least one engagement part, preferably in the form of an engagement clip, of the second cap part, after crossing the step.
In another especially preferred embodiment of the container according to the present invention, the first cap part has a fixing part which in one direction of action enables the process of screwing on the first cap part and in the other direction of action remains on the container and releases the first cap part for an unscrewing process so that in this way a further defined connection to the parts of the container body is formed by the fixing part. This arrangement helps prevent the penetration of foreign media. The fixing part allows the operator reliable use of the cap part arrangement.
In this connection, it is preferable that the fixing part is a ring-shaped fixing body having an elastic catch projecting to the inside and extending in one direction of action over the corresponding catch on the container and interlocking with them in the other direction of action. Preferably, the first cap part on its free side facing the container body has a fixing part and is connected to the fixing part via an easily detachable separation site. In this way, in the process of clearing the container opening via the first cap part, the ring-shaped fixing part remains on the container body and the first cap part can be separated from the fixing part with low actuating forces.
With the container solution according to the present invention, two applications are possible with only one mechanical configuration. Specifically, in one delivery form the opening device of one cap part has already induced opening of the container body. In another delivery form this opening has not yet been effected.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings which form a part of this disclosure and which are schematic and not to scale:
FIGS. 1 to 3 are front elevational views partially in section of an upper part of a container according to an exemplary embodiment of the present invention in different operating states;
FIG. 4 is a perspective bottom view of the first cap part with the fixing part of the container of FIGS. 1 to 3 ;
FIG. 5 is a perspective view of the second cap part of a container with the outer jacket closed according to one alternative embodiment of the present invention; and
FIG. 6 is a perspective view of the second cap of a container with openings according to another alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The container shown in FIG. 1 in its upper region is produced especially in a blow molding process and placed in the mold and sealed. In particular, the container made in the form of an ampule is produced from plastic material. The opening device shown below is also usable for container solutions produced differently. The container body 10 is followed to the top by the neck part 12 onto which the first cap part 14 can be screwed or threaded. This cap part 14 is shown in FIG. 4 in a perspective bottom view. The container body 10 can store a fluid which will not be detailed, for example, in the form of a medicinally acting liquid in the form of eye drops or the like. Instead of liquids, also pasty or gaseous active substances can be placed in the container body, for example, with the blow molding process known in the trade under the trade name “Bottelpack®”.
In addition to the first cap part 14 , a second cap part 16 extends in the axial longitudinal direction 18 of the container at least partially between the first cap part 14 and the neck part 12 . On its side facing the neck part 12 , the second cap part 16 has an opening device 20 with a channel-like opening 22 extending coaxially to the longitudinal axis 18 completely through the second cap part 16 and discharging to the outside via a funnel-shaped widening 24 into the exterior (compare FIG. 3 ). This opening 22 , as seen in FIG. 1 , can be closed by the first cap part 14 . A tapering closure pin 26 located coaxially to the longitudinal axis 18 of the container in the closed position as shown in FIG. 1 closes the channel-like opening 22 by the closure pin 26 engaging the funnel-shaped widening 24 of the second cap part 16 . On its side opposite the widening 24 , the channel-like opening 22 discharges into the ambient space 28 bordered on the one hand by the free face side 30 of the neck part 12 and by the inside jacket surface of the second cap part 16 . In this respect the opening device 20 with a conical, mandrel-like prolongation 32 meshes with the ambient space 28 . The free face side 30 of the neck part 12 is a component of an at least partially convexly shaped dome 34 bordering the ambient space 28 to the bottom. The dome 34 viewed in the direction of FIG. 1 flares down and transitions into a cylindrical overlapping region 36 undergoing transition by tapering toward the neck part free end and to the inside by one step into a cylindrical engagement region 38 which in turn transitions in the direction of a threaded segment 40 on the neck part 12 by a flaring connecting piece.
In the initial position, as shown in FIG. 1 , corresponding to the delivery state of the container solution and reproducing the container before a first use, the first cap part 14 has an inside thread 42 , at least to some extent, acting along the threaded segment 40 . This thread engagement is such that, in the initial position shown in FIG. 1 and in one type of the illustrated embodiments, the tip of the prolongation 32 is not yet engaged with the closed face side 30 of the neck part 12 . This face-side closure of the container neck 12 can be produced by the plastic material of the container itself or in the form of a closure membrane which will not be detailed and which in this context forms the end side 30 of the container neck 12 .
As seen in particular in FIG. 4 as well, on its opposite end the first cap part 14 opens into a ring-shaped fixing part 44 . In one direction of action 46 (see arrow in FIG. 4 ) fixing part 44 enables the process of screwing the first cap part 14 onto the outside thread of the neck part 12 along the threaded segment 40 . In the other, opposite direction of action 48 (compare arrow in FIG. 4 ) first cap 4 remains locked on the container body 10 . The first cap part 14 can be released from the fixing part 44 with a defined actuating force along a separation site 50 made as a line. As FIG. 4 furthermore shows, the separation site 50 is formed of a meandering line structure to which the bordering wall thickness between the fixing part 44 and the first cap part 14 is reduced. The fixing part 44 is designed as a ring-shaped fixing body having elastic catch means or catches 52 projecting to the inside (compare FIG. 4 ) and extending in one direction of action 46 over the corresponding catch means 54 on the container body 10 (compare FIG. 1 ) to interlock with them in the other direction of action 48 . For this purpose the elastic catch means 52 are tongue-shaped and elastically yielding leaf parts on the inner peripheral side of the fixing part 44 . The corresponding catch means 54 on the container itself are formed from bridge-like flank parts which on the neck part 12 projects in the transition region to the top of the container body 10 . The respective catch means 54 can be present in a smaller number than the catch means 52 , for example, in a single arrangement diametrically opposite one another in pairs, comparable to FIG. 1 .
If at this point the first cap part 14 is screwed on in the direction of action 46 and clockwise, it moves into the open position as shown in FIG. 2 . The first cap part 14 entrains the second cap part 16 such that the mandrel-like prolongation 32 extends through the free face side 30 of the neck part 12 forming a fluid-carrying path between the interior of the container body 10 and the first cap part 14 which is still in place. In this process of screwing on the first cap part 14 , the free path of the threaded segment 40 is used up and the first cap part 14 is completely screwed on the outside thread of the neck part 12 . The ring-shaped fixing part 44 as shown in FIG. 2 is engaged with the corresponding catch parts 54 on the neck part 12 around the entire periphery.
For this driving motion the first cap part 14 has at least one pair of driver elements 56 which are diametrically opposite one another (compare FIG. 2 ) and which act on the assigned triangular recesses 58 on the second cap part 16 to induce the driving motion. Both the nose-like projection of each driver element 56 and also the assigned shape of the recess 58 , which shape is triangular viewed in cross section, are selected such that a turning driving motion down for a screw-on process is possible. In the opposite unscrewing movement, the first cap part 14 can be released from the second cap part 16 by the driver element 56 being able to slide out of the assigned recesses 58 without hindrance. Accordingly, the flank angles in the screw-on direction are steeper than the adjacent flank angles assigned to the unscrewing movement of the first cap part 14 .
If at this point the first cap part 14 is unscrewed in the other direction of action 48 and consequently counterclockwise over the threaded segment 40 , the fixing part 44 interlocks on the container neck 12 , and the thin-walled separation site 50 yields. The first cap part 14 then can be completely separated from the container so that a situation as shown in FIG. 3 arises in which the second cap part 16 and the fixing part 44 remain on the container body 10 and in which the first cap part 14 is removed. To ensure that the second cap part 16 remains on the neck part 12 , in the screwing-on process proceeding from FIG. 1 to FIG. 2 , engagement clips 60 attached to the bottom of the second cap part 16 become engaged with the engagement part 38 having a reduced diameter on the neck part 12 . Based on the clip-like engagement configuration, this arrangement allows a certain spring-elastic resilience of the second cap part 16 in its lower region so that due to the conical widening of the neck part 12 in this region the engagement clip 60 can cross the overlapping region 36 on the neck part 12 for a subsequently locking process in the subjacent engagement region as the engagement site 38 . With unscrewing of the first cap part 14 , the funnel-shaped widening 24 is cleared, and the medium stored in the container body 10 is available for a removal process. By screwing on the first cap part 14 again, a situation as shown in FIG. 2 can be established in which the interior of the container body 10 is sealed media-tight.
As seen in FIGS. 5 and 6 , the second cap part 16 is shown in different perspective views. As shown in FIG. 5 , the cap part 16 has a closed outside peripheral surface. On the bottom the individual engagement clips 60 are apparent. In the configuration as shown in FIG. 6 , the outside jacket of the second cap part 16 is shown broken through, with individual rectangular recesses 62 . This configuration has the advantage that the engagement elasticity for the clips 60 is improved so that they can travel into the engagement region 38 with lower actuating forces during the process of screwing-on for the first cap part 14 . As is further seen in the right-hand representation of FIG. 5 , the prolongation 32 has several individual through openings 64 to ensure an improved removal behavior. Preferably, the mandrel-like opening device 20 has several holes which are not located in the middle and which clear the passage between the container and exit opening 22 . Preferably, three such holes on the engagement mandrel are provided in an eccentric arrangement to not weaken the mandrel in its penetration region for opening the container body 10 . In particular, with a plurality of passage openings 64 , spray-like delivery is possible if the container body 10 is elastically resilient such that a manually applied outside pressure moves the stored medium on to the spray region in the form of the second cap part 16 . To be able to more easily induce the different screwing processes in the two directions 46 , 48 of action by hand and in order especially to also achieve separation at the separation site 50 with low actuation forces, the outer cylindrical periphery of the first cap part 14 has a handling device in the form of ribbing 66 (compare FIG. 4 ).
In the delivery form as shown in FIG. 1 , engagement with the container interior has not yet taken place. It is also fundamentally conceivable to select a delivery form as shown in FIG. 2 in which the second cap part 16 has already effected an opening process for the container. Based on the already explained threaded segment 40 and with respect to the fixing region of the fixing part 44 on the shoulder transition site between the neck part 12 and the container body 10 , media-tight separation relative to the exterior is achieved with increased sterility requirements.
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
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A container, in particular a plastic ampule produced using a blow-molding process and filled and closed in the mold has a neck part ( 12 ) adjoining a container body ( 10 ) and threadly receiving a first cap part ( 14 ). A second cap part ( 16 ) extends at least partly between the first cap part ( 14 ) and the neck part ( 12 ) and is provided with an opening device ( 20 ). The opening device has at least one opening ( 22 ) for opening the container body ( 10 ), and can be closed by the first cap part ( 14 ). The first cap part ( 14 ) carries the second cap part ( 16 ) by the screwing-on process of the first cap part in such a way that the opening device ( 20 ) causes the container body ( 10 ) to be opened. A closure part (closure pin 26 ) of the first cap part ( 14 ) unblocks the opening ( 22 ) in the opening device ( 20 ) after the first cap part is unscrewed, with the second cap part ( 16 ) remaining on the neck part ( 12 ).
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RELATED APPLICATIONS
This is a regularly filed application, based on provisional application Ser. No. 60/194,381, filed Apr. 4, 2000 which is a divisional of 09/819,591 filed Mar. 28, 2001, now U.S. Pat. No. 6,519,955.
TECHNICAL FIELD
The present invention relates to cooling of electrical and electronic components, and more particularly, to a liquid refrigerant pump to circulate refrigerant to multiple cold plate/evaporators in thermal contact with the electrical or electronic component to be cooled.
BACKGROUND OF THE INVENTION
Electrical and electronic components (e.g. microprocessors, IGBT's, power semiconductors etc.) are most often cooled by air-cooled heat sinks with extended surfaces, directly attached to the surface to be cooled. A fan or blower moves air across the heat sink fins, removing the heat generated by the component. With increasing power densities, miniaturization of components, and shrinking of packaging, it is sometimes not possible to adequately cool electrical and electronic components with heat sinks and forced air flows. When this occurs, other methods must be employed to remove heat from the components.
One method for removing heat from components when direct air-cooling is not possible uses a single-phase fluid which is pumped to a cold plate. The cold plate typically has a serpentine tube attached to a flat metal plate. The component to be cooled is thermally attached to the flat plate and a pumped single-phase fluid flowing through the tube removes the heat generated by the component.
There are many types of cold plate designs, some of which involve machined grooves instead of tubing to carry the fluid. However all cold plate designs operate similarly by using the sensible heating of the fluid to remove heat. The heated fluid then flows to a remotely located air-cooled coil where ambient air cools the fluid before it returns to the pump and begins the cycle again. This method of using the sensible heating of a fluid to remove heat from electrical and electronic components is limited by the thermal capacity of the single phase flowing fluid. For a given fluid to remove more heat, either its temperature must increase or more fluid must be pumped. This creates high temperatures and/or large flow rates to cool high power microelectronic devices. High temperatures may damage the electrical or electronic devices, while large flow rates require pumps with large motors which consume parasitic electrical power and limit the application of the cooling system. Large flow rates may also cause erosion of the metal in the cold plate due to high fluid velocities.
Another method for removing heat from components when air-cooling is not feasible uses heat pipes to transfer heat from the source to a location where it can be more easily dissipated. Heat pipes are sealed devices which use a condensable fluid to move heat from one location to another. Fluid transfer is accomplished by capillary pumping of the liquid phase using a wick structure. One end of the heat pipe (the evaporator) is located where the heat is generated in the component, and the other end (the condenser) is located where the heat is to be dissipated; often the condenser end is in contact with extended surfaces such as fins to help remove heat to the ambient air. This method of removing heat is limited by the ability of the wick structure to transport fluid to the evaporator. At high thermal fluxes, a condition known as “dry out” occurs where the wick structure cannot transport enough fluid to the evaporator and the temperature of the device will increase, perhaps causing damage to the device. Heat pipes are also sensitive to orientation with respect to gravity. That is, an evaporator which is oriented in an upward direction has less capacity for removing heat than one which is oriented downward, where the fluid transport is aided by gravity in addition to the capillary action of the wick structure. Finally, heat pipes cannot transport heat over long distances to remote dissipaters due once again to capillary pumping limitations.
Yet another method which is employed when direct air-cooling is not practical uses the well-known vapor compression refrigeration cycle. In this case, the cold plate is the evaporator of the cycle. A compressor raises the temperature and pressure of the vapor, leaving the evaporator to a level such that an air-cooled condenser can be used to condense the vapor to its liquid state and be fed back to the cold plate for further evaporation and cooling. This method has the advantage of high isothermal heat transfer rates and the ability to move heat considerable distances. However, this method suffers from some major disadvantages which limit its practical application in cooling electrical and electronic devices. First, there is the power consumption of the compressor. In high thermal load applications the electric power required by the compressor can be significant and exceed the available power for the application. Another problem concerns operation of the evaporator (cold plate) below ambient temperature. In this case, poorly insulated surfaces may be below the dew point of the ambient air, causing condensation of liquid water and creating the opportunity for short circuits and hazards to people. Vapor compression refrigeration cycles are designed so as not to return any liquid refrigerant to the compressor which may cause physical damage to the compressor and shorten its life by diluting its lubricating oil. In cooling electrical and electronic components, the thermal load can be highly variable, causing unevaporated refrigerant to exit the cold plate and enter the compressor. This can cause damage and shorten the life of the compressor. This is yet another disadvantage of vapor compression cooling of components.
It is seen then that there exists a continuing need for an improved method of removing heat from components when air-cooling is not feasible.
SUMMARY OF THE INVENTION
This need is met by the pumped liquid cooling system of the present invention wherein cooling is provided to electrical and electronic components with very low parasitic power consumption and very high heat transfer rates away from the component surface. This invention also reduces the temperature drop required to move heat from the component to the ambient sink.
In accordance with one aspect of the present invention, a liquid refrigerant pump circulates refrigerant to cold plate/evaporators which are in thermal contact with the electrical or electronic component to be cooled. The liquid refrigerant is then partially or completely evaporated by the heat generated by the component. The vapor is condensed by a conventional condenser coil, and the condensed liquid, along with any unevaporated liquid, is returned to the pump. The system of the present invention operates nearly isothermally in both evaporation and condensation.
Accordingly, it is an object of the present invention to provide cooling to electrical and electronic components. It is a further object of the present invention to provide such cooling to components with very low parasitic power consumption and very high heat transfer rates away from the component surface. It is yet another object of the present invention to reduce the temperature drop required to move heat from the component to the ambient sink.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram illustrating the pumped liquid cooling system in accordance with the present invention; and
FIG. 2 illustrates a plurality of cold plate evaporator devices, each in thermal contact with a component to be cooled.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, there is illustrated a cooling system 10 which circulates a refrigerant as the working fluid. The refrigerant may be any suitable vaporizable refrigerant, such as R-134a. The cooling cycle can begin at liquid pump 12 , shown as a Hermetic Liquid Pump. Pump 12 pumps the liquid phase refrigerant to a liquid manifold 14 , where it is distributed to a plurality of branches or lines 16 . Additional liquid manifolds 14 a, 14 b and 14 n are shown to indicate where more branches (or lines) could be attached. The actual number of branches will depend on the number of components to be cooled by the system. From the manifold 14 , each branch or line 16 feeds liquid refrigerant to a cold plate 18 .
As illustrated in FIG. 2, each cold plate 18 is in thermal contact with an electrical or electronic component or components 20 to be cooled, causing the liquid refrigerant to evaporate at system pressure. None, some, or all of the liquid refrigerant may evaporate at cold plate 18 , depending on how much heat is being generated by component 20 . In most cases, some of the refrigerant will have evaporated and a two-phase mixture of liquid and vapor refrigerant will leave each cold plate 18 , as shown by arrow 22 .
In a preferred embodiment of the present invention, at this point in the operation of the system, each cold plate 18 discharges its mixture of two-phase refrigerant to vapor/liquid separator 24 , as illustrated in FIG. 1 . For most applications, the vapor/liquid separator 24 is a vertical tube of sufficient diameter to allow the heavier liquid refrigerant to fall to the bottom of the tube by gravity, while the lighter vapor rises to the top of the tube. In this manner, any unevaporated refrigerant is separated from the vapor and each phase may be treated separately within the system.
The vapor/liquid separator 24 is attached to a vapor line 26 leading to condenser 28 , comprised of a condensing coil 30 and a fan 32 . Additional vapor/liquid separators 24 a, 24 b, and 24 n, may be connected through the use of vapor manifolds so that the cooling capacity of the system may be increased. Condenser coil 30 , attached to vapor line 26 , condenses the vapor phase back to a liquid and removes the heat generated by the electronic components 20 . In FIG. 1, an ambient air-cooled condenser 28 is shown, using fan 32 , although it will occur to those skilled in the art that any suitable form of heat rejection may be used without departing from the scope of the invention, such as an air cooled condenser, a water or liquid cooled condenser, or an evaporative condenser.
The condenser 28 operates at a pressure which corresponds to a temperature somewhat higher than the temperature of the ambient air. In this way, it is impossible for condensation to form, since no system temperature will be below the ambient dew point temperature. The condenser operating point sets the pressure of the entire system by means of the entering coolant temperature and its ability to remove heat from the condenser, thus fixing the condensing temperature and pressure. Also, since vaporized refrigerant is being condensed to a liquid phase, the condenser 28 sets up a flow of vaporized refrigerant from the vapor/liquid separator 24 into the condenser 28 , without the need for any compressor to move the vapor from the cold plate-evaporator 18 to the condenser 28 . The liquid refrigerant exits the condenser 28 , as indicated by arrow 34 , and moves by gravity to a liquid receiver 36 , which holds a quantity of liquid refrigerant.
In one embodiment of the invention, connected to the liquid receiver 36 is a second and optional liquid return line 38 from the vapor/liquid separator 24 . Alternatively, all liquid can be returned to the pump 12 via line 26 , passing through the condenser 28 to change vapor back to liquid. With the addition of liquid return line 38 , there are two sources of liquid refrigerant. One source of liquid refrigerant is from the condenser and the other is from the separator. Either line 26 , or line 38 , or both, can be used to carry any unevaporated liquid refrigerant from the separator 24 to the liquid receiver 36 , where it may be used again in the cycle. The liquid receiver, therefore, can receive liquid from the condenser or from the separator. The quantity of liquid refrigerant held in the liquid receiver 36 provides a liquid head over the inlet of the pump 12 so the pump operates reliably. The liquid receiver 36 also handles changes in the amount of liquid refrigerant in the system 10 by providing a reservoir to store refrigerant. The outlet of the liquid receiver is connected to the inlet of the liquid refrigerant pump 12 . At the pump 12 , the pressure of the refrigerant is raised sufficiently to overcome the frictional losses in the system and the cooling cycle begins again. The pump 12 is selected so that its pressure rise is equal to or exceeds the frictional loss in the system at the design flow rate.
Unlike the pumped liquid single-phase system, the present invention operates isothermally, since it uses change of phase to remove heat rather than the sensible heat capacity of a liquid coolant. This allows for cooler temperatures at the evaporator and cooler components than a single-phase liquid system. Low liquid flow rates are achieved through the evaporation of the working fluid to remove heat, keeping the fluid velocities low and the pumping power very low for the heat removed. Parasitic electric power is reduced over both the pumped single-phase liquid system and the vapor compression refrigeration system.
An advantage over the heat pipe system is obtained with the system 10 of the present invention because the liquid flow rate does not depend on capillary action, as in a heat pipe, and can be set independently by setting the flow rate of the liquid pump. Dry out can thus be avoided. The cold plate/evaporator system of the present invention is insensitive to orientation with respect to gravity. Unlike heat pipe systems, the thermal capacity of the evaporator 18 of the present invention does not diminish in certain orientations.
Another advantage of the present invention over heat pipe and vapor compression based systems is the ability to separate the evaporator and condenser over greater distances. This allows more flexibility in packaging systems and design arrangements. In accordance with the present invention, liquid and vapor are transported independently, allowing for optimization of liquid and vapor line sizes. The present invention easily handles variation in thermal load of the components 20 to be cooled. Since any unevaporated liquid refrigerant is returned to the pump, multiple cold plates at varying loads are easily accommodated without fear of damaging a compressor. Since the current invention does not operate at any point in the system 10 at temperatures below ambient dew point temperature, there is no possibility of causing water vapor condensation and the formation of liquid water.
Having described the invention in detail and by reference to the preferred embodiment thereof, it will be apparent that other modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
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An improved cooling system provides cooling away from the surface of electrical and electronic components with very low parasitic power consumption and very high heat transfer rates. The component to be cooled is in thermal contact with a cold plate evaporator device. Refrigerant is circulated by a liquid refrigerant pump to the cold plate evaporator device, and the liquid refrigerant is at least partially evaporated by the heat generated by the component. The vapor is condensed by a conventional condenser coil and the condensed liquid along with any unevaporated liquid is returned to the pump. The system operates nearly isothermally in both evaporation and condensation.
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BACKGROUND OF INVENTION
Apart from a few exceptions, most polymer materials are combustible. It is therefore necessary to modify these polymer materials to make them fire-retardant for many applications such as the construction, furniture, vehicle or electronics industry. To satisfy corresponding regulations or standard tests, organohalogen or organcophorus compounds are added in large amounts as flameproofing agents to plastics (G. Gechta, H. Müller, Plastics Additives Handbook, Hanser Publishers 1993, pp. 708-725).
Organohalogen compounds that are not toxic in themselves can release corrosive pyrolysis components that are hazards to health in the event of a fire. Consequently, there have been numerous attempts to replace these critically evaluated organic flameproofing agents with other organic flameproofing agents, like melamine, or inorganic flameproofing agents. Antimony oxide, red phosphorus, ammonium polyphosphate, and inorganic boron compounds have been used, among others, as flameproofing additives in polymer materials alone or in combination.
Hydroxides of di- and trivalent metals are being increasingly used as fully nontoxic and noncorrosive flameproofing agents. Aluminum and magnesium hydroxide have gained particular significance (G. Kirschbaum Kunststoffe 79, 1989, pp. 1205-1208 and R. Schmidt, Kunststoffe 88, 1998, pp. 2058-2061). Both hydroxides release water in the temperature range between 200-400° C., which absorbs energy by evaporation and therefore leads to cooling of the polymer materials. The smoke density is also reduced.
The very high quality which is necessary in order to make polymer materials flameproof enough that they can pass fire tests is mentioned as a drawback of these hydroxide flameproofing agents. In addition, the extrusion and mechanical properties of these polymer materials, however, deteriorate to a high degree because of the high degree of filling.
Consequently, there has been several attempts to reduce the amount of these hydroxide flameproofing agents by combination with additional organic or inorganic flameproofing agents.
For example, JP 63 273,693-A, JP 63 030,588-A, JP 62 101,644-A as well as EP 333514-A describe flameproof polymer materials and coatings that contain metal hydroxides as flameproofing additives and clay minerals, like kaolin, mica, vermiculite or bentonite or montmorillonite as filler.
JP 55 112,248-A describes flameproof polyolefin materials for cable insulation that contain aluminum hydroxide, zinc borate, calcium carbonate, talc and bentonite in a particle size from 0.01 to 30 μm.
JP 62 181,144 describes flameproof polyester, polypropylene and polyvinyl fluoride films that contain phosphorus-, nitrogen- or halogen-containing flameproofing agents and are coated with a mixture of layer silicates that are swellable in water, like montmorillonite, vermiculite or hectorite with silanes as coupling agent.
Attempts have also been made to improve flameproofing by addition of organically intercalated bentonites or montmorillonites. J. W. Gilmann and J. D. Lichtenhan (SAMPE Journal, Vol. 33, 1997, No. 4, pp. 40-46) describe so-called nanocomposites based on polyamide 6. These materials consist of a polyamide 6 matrix in which montmorillonite particles are dispersed that were intercalated beforehand with aminododecanoic acid. Addition of between 2 and 5% of this nanocomposite filler leads to a reduction of peak-of-heat release (PHR) by up to 63%.
Since adequate flameproofing cannot be guaranteed with organically intercalated layer silicate fillers as the only flame-retardant additives, attempts have also been described to combine organically intercalated clay minerals with other flameproofing agents.
EP 239 986-A describes a non-dripping, flameproof thermoplastic copolyester composition containing 5 to 35% of a flameproofing agent mixture. This mixture contains a bromine- or chlorine-containing compound with at least 50% Br or Cl, 0.2 to 1.5 parts by weight antimony oxide per part by weight of the bromine- and chlorine-containing compound, as well as at least one part by weight of a quaternized bentonite as an antidrip agent, 5 to 100 parts by weight aluminum hydroxide and up to 100 parts by weight calcium carbonate, each based on 100 parts by weight copolyester. Addition of aluminum hydroxide and calcium carbonate is supposed to reduce the smoke density and increase charring.
U.S. Pat. No. 5,773,502 describes a non-dripping, flameproof thermoplastic polyester material that contains the following flameproofing additives: 5 to 20 wt % halogen-containing organic flameproofing agent, 1 to 5 wt % antimony oxide, 0.25 to 5 wt % of an organophilic clay and 0.02 to 2 wt % of a fluorine-containing polymer.
GB-A 1 14 174 describes a polymer composition that contains 0.5 to 50 wt % of a flameproofing agent and up to 10 wt % of a bentonite modified with organic cations in addition to the base polymer (polyamide, polystyrene or polyolefin). Phosphoric acid esters, antimony trioxide or arsenic trioxide are used as flameproofing agents in addition to halogenated organic compounds. The use of magnesium, calcium or aluminum hydroxide as flameproofing agents is not described.
EP 132 228-A describes flame-resistant reinforced polyester molding compounds with 3 to 50 wt % reinforcing filler (preferably glass fibers), 5 to 30 wt % of a flame-resistant additive, 0.2 to 4 wt % of an optionally organically modified layer silicate as an antidrip agent and 0.05 to 2 wt % of an alkali metal salt of a monocarboxylic acid with 6 to 22 carbon atoms. Quaternized bentonites, like Bentone® 27, 34, 38 are preferably used as antidrip agents. Appropriate flameproofing additives are preferably organic halogen compounds alone or in combination with antimony trioxide. However, there is no indication of the use of hydroxides as flameproofing additives.
All the mixtures described above, including organically modified. Layer silicates and additional flameproofing additives have the common feature that these mixtures contain more or less toxic components and/or corrosive components in the event of a fire.
Flameproof halogen-free polymer compositions are known from EP 0 893 469-A that contain a mixture of different polymers or copolymers and an inorganic filler, like aluminum trihydrate or magnesium hydroxide.
SUMMARY OF INVENTION
It has now surprisingly been found that a synergistic flameproofing effect occurs for flameproofed polymer mixtures that contain essentially no additional organohalogen or organophosphorus flameproofing agents, if they contain in addition to metal hydroxides, organically intercalated layer silicates and optionally other inorganic flameproofing agents.
The object of the invention is therefore a flameproof, essentially halogen-free, polymer composition containing:
a) 100 parts by weight of a thermoplastic, crosslinkable or crosslinked elastomeric and/or thermosetting polymer;
b) 10 to 200 parts by weight magnesium, calcium, zinc and/or aluminum hydroxides and/or their double hydroxides;
c) 1 to 50 parts by weight of an organically intercalated layer silicate.
The layer spacing of the organically intercalated layer silicate in the polymer is preferably at least 10% greater than that of the original layer silicate.
DETAILED DESCRIPTION OF THE INVENTION
The development objective was to prepare flameproof polymer compositions in which the use of organic halogen compounds and organic phosphorus compounds are dispensed with since such substances release toxic and/or corrosive gases in the event of fire.
“Essentially halogen-free” is understood according to the invention to mean polymer compositions whose halogen content (referring to low-molecular halogen compounds) is less than 5 wt %, preferably less than 2 wt %. If the polymers are halogen-containing polymers (for example, PVC), their halogen content is not considered here.
By omitting the organohalogen compounds, an improvement in the mechanical properties and charring is surprisingly achieved.
The effect according to the invention is probably based on the fact that the layer spacing determined by x-ray of the organically intercalated layer silicate is widened by the incorporation of the polymer molecules and that the organic halogen compounds are bound to the layer silicates so that they can no longer act as radical scavengers in the gas phase in the event of fire and the radical chain reactions that occur during combustion can run undisturbed. Use of an additional amount of the organically intercalated layer silicates without simultaneous use of an organohalogen compound causes a significant improvement in mechanical properties with comparable flameproofing properties, and also an improvement in charring.
The hydroxides or double hydroxides of magnesium, calcium, zinc and/or aluminum used according to the invention liberate water exclusively in the event of fire and therefore do not form toxic or corrosive smoke products. Moreover, these hydroxides are in a position to reduce the smoke density in the event of fire.
The employed polymer (a) according to the invention is preferably chosen from polyolefins (like polyethylenes, polypropylenes or polybutenes); vinyl polymers (like Polyvinyl chloride or polyvinylidene chloride); styrene polymers, polyacrylonitrile; polyacrylates and methacrylate; natural and synthetic rubbers; fluorine plastics (like tetrafluoroethylene or polyvinyl fluoride), thermoplastic polycondensates (like polyamide, polyesters, polycarbonates, polyethylene terephthalate); thermosetting polycondensates (like phenol-formaldehyde plastics, urea-formaldehyde plastics, melamine-formaldehyde plastics, unsaturated polyester resins, silicone resins, polyimide); thermosetting and thermoplastic polyadducts (like epoxy resins, polyurethanes and isocyanate resins); co- or terpolymers, as well as graft polymer from them; and their mixtures.
A summary of appropriate plastics can be found in Hans Domininghaus “Plastics and their properties,” second edition, VDI Verlag, pp. 7 to 11.
In order to achieve a flameproof finishing required for different applications, the percentage of hydroxide (b) is preferably about 30 to 80 wt %. At higher percentages of filling, the mechanical properties of the corresponding polymer materials deteriorate unacceptably. The tensile strength and breaking elongation, which is important for cable insulation in particular, also decline to an unacceptable degree.
However, it was surprisingly found that the amount of added flameproofing hydroxides (b) can be substantially reduced if organically intercalated layer silicates (c) are incorporated in the polymer mixtures as additional flameproofing additives. A synergistic effect is found between the organically intercalated layer silicate and the flameproofing hydroxides. For example, by addition of 5 wt % of the organically intercalated layer silicates, the aluminum hydroxide fraction can be reduced by 15% so that with improved flameproofing, higher breaking elongation and reduced processing viscosity occurs.
The metal hydroxides (b) preferably have a specific surface area of 3 to 150 m 2 /g, especially 3 to 50 m 2 /g and an average particle size of about 1 to 20 μm, preferably about 1 to 10 μm.
The metal hydroxides (b) can be modified on the surface, for example, hydrophobized, for example with silane.
Swellable smectites, like montmorillonite, hectorite, saponite or beidellite are preferably used as the starting materials for the organically intercalated layer silicates (c).
The organically intercalated layer silicates have a layer spacing of about 1.5 to 4 nm. These layer silicates are preferably intercalated with quaternary ammonium compounds, protonated amines, organic phosphonium ions and/or aminocarboxylic acids.
Preferably about 1 to 100 parts by weight of additional halogen-free flameproofing additives can also be added, like antimony oxide, red phosphorus, zinc sulfide, melamine derivatives, organophosphorus compounds and/or inorganic boron compounds.
The invention is explained by the following examples.
EXAMPLES 1 to 8
1. Employed Starting Materials
Polymer: 4 parts by weight low-density polyethylene (Escorene® LLN 1001 XV from Exxon)+1 part by weight ethylene vinyl acetate copolymer (EVA Escorene® UL 00328 from Exxon)
Organically intercalated layer silicate: (manufacturer described below)
Aluminum hydroxide: Martinal® OL 104LE (Martinswerk) Magnesium hydroxide: Magnifin® H 5 (Martinswerk)
2. Production of the Organically Intercalated Layer Silicate
2.5 kg of dry natural sodium bentonite (Volclay® SPV) is stirred into 100 L of demineralized water using an agitator. The suspension is agitated for 24 hours at room temperature. The suspension is then heated at 85° C. and a solution heated to 80° C. containing 1.6 kg dimethyldistearylammonium chloride and 30 L demineralized water also under vigorous mixing is metered over a period of 60 minutes. After addition of the intercalation components is complete, the mixture is further agitated for 5 hours at 85° C. The suspension, cooled to 50° C., is then introduced to a filter chamber press, filtered off and washed with 1000 L demineralized water. The obtained precipitate is then dried for 24 hours in a forced-air furnace at 110° C. The dried product is then ground with an impact mill to a particle size of <63 μm. The layer spacing determined by x-ray is 2.8 nm.
3. Production of Polymer Compounds
Powdered, intercalated layer silicate, aluminum hydroxide and magnesium hydroxide and optionally additional powdered additives are initially mixed manually and then introduced with the polymer granulate gravimetrically to a laboratory kneader (MDK 46 with 11 L/D from the Buss Co., Switzerland) and compounded at a temperature of about 150° C. for aluminum hydroxide and 220° C. for magnesium hydroxide. The amount is 10 kg/h. The compounded mixture is withdrawn as a double strand from the compounding machine, cooled via a water bath and then cut in a granulator to a granulate with a diameter of 2 to 3 mm and a length of 2 to 5 mm. The obtained granulate is then dried for 10 hours at 90° C. in a forced-air furnace.
4. Extrusion of Samples
The dried granulate is extruded to a strip about 3 mm thick on a single-screw extruder from the Leistritz Co., Nurnberg in order to produce samples to determine the mechanical properties.
5. Cone-calorimeter Test
According to ASTM E 1345 and ISO 5660. The plates for the cone experiments were produced on a press from the Schwabenthan Co.
6. Determination of Mechanical Properties
Determination of the tensile E modulus occurred according to DIN 53457 with a tensile rate of 1 mm/min.
Determination of tensile strength (TS) occurred according to DIN 53455.
Determination of breaking elongation (BE) occurred also according to DIN 53455.
Determination of the melt flow index (MFI) occurred according to DIN 53735.
7. Determination of LOI (Limiting Oxygen Index)
Determination of LOI occurred according to ISO 4589, part 2.
The composition and the results for examples 1 to 8 are shown in Table 1. Examples 1, 2, 4 and 6 are comparative examples without Al(OH) 3 or without organically intercalated layer silicate. Comparative example 8 contains no organically intercalated layer silicate and no hydroxide. The values for PHR, Ti and breaking elongation are much poorer for these examples than those in examples 3, 5 and 7 according to the invention.
TABLE 1
Example
1
2
3
4
5
6
7
8
Polymer
100.00
45.00
45.00
45.00
45.00
45.00
45.00
100.00
Al(OH) 3
55.00
55.00
40.00
40.00
Mg(OH) 2
55.00
55.00
Ogranically intercalated layer silicate
5.00
5.00
5.00
5.00
PHR (KW/m 2 )
488
202
105
302
189
191
85
1215
TI (s)
72
128
174
124
175
212
287
32
ASSEA (m 2 /kg)
3150
1600
3900
1810
3700
1850
LOI
21
32
34
27
29
36
39
19
TS (MPa)
19
15
14
13.5
13
14
13
20
BE (%)
650
250
240
320
300
220
200
600
MFI (g/10 min)
4.0
2.2
2.0
2.8
2.6
2.0
1.9
4.0
PHR
Peak of heat release
TI
Time to ignition
ASSEA
Average specific smoke extinction area
TS
Tensile strength
BE
Breaking elongation
MFI
Melt flow index at 150° C. with 21.6 kg
EXAMPLES 9 to 11
The procedure of examples 1 to 8 was followed with the deviation that the polymer mixture according to these examples was used together with bis(tert-butylperoxyisopropyl)benzene as a crosslinking agent (Peroxan® ( BIB) in a 100:6 ratio.
The composition and results are shown in Table 2. Comparative examples 9 and 10 show poorer PHR, BE and TI values relative to example 11, which is prepared according to the invention. The absence of Al(OH) 3 in comparative example 9 leads to particularly poorer results.
TABLE 2
Crosslinked mixture.
Example
9
10
11
Polymer
100.00
45.00
45.00
Al(OH) 3
55.00
55.00
Organically intercalated
5.00
5.00
layer silicate
PHR (KW/m 2 )
450
190
98
TI(s)
70
121
165
ASSEA (m 2 /kg)
3030
1580
LOI
21
32
34
TS(MPa)
20
17
15
BE (%)
480
190
160
EXAMPLES 12 to 19
The procedure of examples 1 to 8 was followed with the deviation that a polyamide was used as the polymer for examples 12 to 15 (Grilamide® L16L from EMS Chemie) and a polystyrene as polymer for examples 16 to 19 (Vestyron® 106 by Hüls).
The composition and results are shown in Table 3. Comparative examples 12, 13, 15, 16, 17 and 19 show poorer PHR and TI values relative to examples 14 and 18 which are prepared according to the invention. The absence of Mg(OH) 2 in comparative examples 12, 15, 16 and 19 leads to particularly poorer results.
TABLE 3
Thermoplastic mixture.
Example
12
13
14
15
16
17
18
19
Polymer
100.00
45.00
45.00
100.00
100.00
45.00
45.00
100.00
Mg(OH) 2
55.00
55.00
55.00
55.00
Organically intercalated layer silicate
5.00
5.00
5.00
5.00
PHR (KW/m 2 )
450
190
100
1060
400
180
120
1170
TI (s)
70
135
182
35
69
135
170
42
EXAMPLES 20 to 24
The procedure of examples 1 to 8 was followed with the deviation that polypropylene grafted with maleic anhydride (Fusabond® MDS11-D from DuPont) was used as the polymer. The comparative examples 22 and 23 also contained decabromodiphenyl oxide (Adine® 102 from Atochem) and Sb 2 O 3 as flameproofing agents in a weight of 1:3. Example 20, which was prepared according to the invention, gave much better PHR and TI values than the comparative examples.
The composition and results are shown in Table 4.
TABLE 4
Example
20
21
22
23
24
Polymer
45.00
100.00
80.00
80.00
100.00
Bromine containing
20.00
20.00
flameproofing agent
Al(OH) 3
40.00
Organically intercalated
5.00
5.00
5.00
layer silicate
PHR (KW/m 2 )
770
945
825
940
2050
|
The invention relates to a flameproof, essentially halogen-free polymer composition, containing the following: a) 100 parts by weight of a thermoplastic, cross-linkable or cross-linked, elastomeric and/or duroplastic polymer; b) 10 to 200 parts by weight of magnesium, calcium, zink and/or aluminiumhydroxide and/or their double hydroxides; c) 1 to 50 parts by weight of an organic intercalated sheet silicate.
| 2
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BACKGROUND OF THE INVENTION
The present invention concerns central heating and/or hot-water production installation, of the type using at least one conventional source of heat of the liquid or gaseous fuel boiler type, and at least one thermodynamic heat pump source of heat, particularly of the compression heat cycle formed by a closed circuit in which flows a refrigerating fluid and comprising in series, in a way known per se, an evaporator, a compressor, a condenser forming the thermodynamic heat source properly speaking, and an expansion means for the condensed refrigerating fluid, one or more circuits for the circulation of the heat-carrying fluid of the central heating and for the production of sanitary or industrial hot water being furthermore provided and arranged to be the seat of heat exchanges with said above-mentioned heat sources.
Of course, this kind of installation may comprise one or more boilers and one or more heat circuits according to the application contemplated. These installations may in this respect be provided for heating living, industrial use, commercial or else agricultural premises for the whole or part of the year, and the hot water produced may also be for different uses, for example for sanitary or industrial use. As for the heat-carrying fluid of the central heating, it will be readily understood that it may be any appropriate fluid, for example water or air.
Installations of the above-defined type are known, i.e. in brief installations using heat sources of different kinds, on the one hand conventional of the boiler kind consuming a liquid or gaseous fuel, on the other hand of the heat pump thermodynamic kind, the heat being taken from any cold source (outside air, river, etc.). These installations have been developed in recent years since attempts have been made to economize fuels.
However, it is observed that known installations are not yet adapted for obtaining the best possible energy yields. In particular, conventional central heating boilers do not use as well as possible the energy of the fuel. They only use the lower heating power of the fuel, instead of using the higher heating power thereof. In particular, conventional boilers, whether they are used alone or in combination with the other heat sources in question, do not take advantage of the latent heat of vaporization of the water contained in the combustion gases, for the vapor is for a large part discharged into the atmosphere with the smoke; they only use the sensible heat of the combustion gases, and even so imperfectly. In fact, the combustion gases are discharged into the chimney at a temperature still relatively high, i.e. heat is still lost. Finally, there is in general an air intake to the burners which is excessive in relation to the needs of a stoechiometric combustion.
All that results in only 80 to 85% of the upper heating power of the fuel being used in such installations.
It should also be noted that the temperature of the heat-carrying fluid of conventional boilers is often maintained higher than that necessary for the central heating, because of the necessarily higher temperature which is required for the production of sanitary or industrial hot water; that makes more perceptible the weakness--relative--of the efficiency of the boiler during periods of moderate heating.
Furthermore, if we now consider no longer the boiler(s) and their efficiency, but their association, in installations of the type in question, with other heat sources of the heat pump kind, poor cooperation of these two kinds of sources is generally found, because designed separately and associated in a way which, from the point of view of energy efficiency and complementarity, is far from being ideal, at least during a considerable proportion of the year, particularly in the cold season.
As for heat pumps, it is known particularly from theory and practice that their overall energy efficiency diminishes when the temperature difference between the cold source and the hot source increases, i.e. especially when the temperature of the cold source diminishes, which is the case as a rule in winter, precisely when the heat needs for heating the premises are the highest. Furthermore, even as far as the production of sanitary hot water is concerned, a temperature of 60° to 65° C. must be obtained for the condenser of the heat pump concerned, assuming that the heat for the production of this hot water is taken directly from this condenser rather than from the boiler, which for low temperatures at the evaporator only allows a mediocre efficiency for the heat pump to be obtained. The ideal temperature difference between the evaporator and the condenser ranges in fact between about 40° and 45° C. When atmospheric air is used as the cold source, the reduction of the enthalpy of this air in winter makes this lowering of the efficiency of the heat pump particularly clear.
An additional important problem is moreover often posed in winter, when compression cycle heat pumps are used: it is the problem of icing up of the evaporator (or evaporators) whose de-icing may require the use of a supplementary source of heat, sometimes an electric heating device and which, whatever the solution chosen, contributes further to diminishing the efficiency of the heat pump (taking a part of the heat of the condenser for de-icing, or other solutions).
Finally, it should be noted that the power of the compressors is relatively limited, because of the high electric current consumed at start-up.
The aim of the present invention is generally to remedy these shortcomings found in known installations such as defined at the beginning. This aim is in particular to use better than before the heating power of the fuel, and to take advantage of the heat for vaporizing the water vapor contained in the fumes; it is to discharge this smoke into the atmosphere at the lowest possible temperature, a little above 0° C., and thus finally to use in the best way possible the enthalpy of the combustion gase (sensible heat and latent heat). This aim of the invention is at the same time, in installations of the kind in question, to arrange things so that the heat pump(s) operate under conditions enabling them to reach a better efficiency and in any case under the best possible operating conditions, whether in cold or hot seasons, for central heating or for the production of sanitary or industrial hot water alone, by using in the best way possible the free enthalpy of the cold source, i.e. principally that of atmospheric air.
SUMMARY OF THE INVENTION
All these aims are attained in an installation of the kind defined at the beginning wherein, in accordance with the invention, the evaporator(s) of the heat pump(s) are located in a duct for discharging the combustion gases of the boiler, and which comprises, in conjunction with this duct, one or more outside air intakes provided with flow-regulating means upstream of said evaporator(s).
With this arrangement, the combustion gases of the boiler pass over the evaporator(s) of the heat pump(s) and they are cooled while supplying heat to the evaporators and this with condensation of the water vapor which they contain. Thus the total heat of the smokes is better used before their low-temperature discharge into the atmosphere. Thus the usual loss in heat is considerably reduced and the upper heating power of the fuel is used in the best way possible.
Furthermore, the enthalpy of the outside air is used under much better conditions than before, here again as for the smokes, by using its sensible heat and the latent heat of the water vapor which it contains for heating the evaporator(s) and for evaporating the refrigerating fluid, for it is possible with the above-defined arrangement to operate at least some of the heat pumps with a temperature at the evaporator higher than in the installations of the prior art, because this fresh air coming from outside mixes with the hotter smoke before passing over the evaporator(s). In addition, it will be easy to avoid icing-up of the evaporators, which risks occurring especially in winter, since precisely at this season the boiler(s) will be operating. There will then be no additional energy required for carrying out this de-icing. As for the flow-regulating means, they will of course enable the proportion of the heat flow coming directly from the boiler and of the thermodynamic source flow, i.e. the amount of heat coming from the outside air, to be regulated at will, depending on certain outside, for examle climatic, conditions or conditions of use (a greater or lesser demand for sanitary or industrial hot water in relation to the heating demand from the central heating, etc.).
It may be noted here that the outside air used in the installation may, when the boiler is in operation, be formed essentially of two parts: one part passing through the boiler, used as stoechiometric air and even in excess in relation to the stoechiometric conditions, which ensures perfect combustion of the fuel and, by diluting the smoke, will avoid fouling up of the discharge duct; and one part not passing through the boiler but arriving downstream of the conventional part thereof, as it were through a by-pass, directly into the duct, for the production of heat by means of the thermodynamic circuit(s). This second air flow will in general be considerably higher (for example twenty to fifty times greater) than that of the air required for the stoechimetric combustion of the fuel, and this particularly when the season or the climatic conditions increase the enthalpy of the outside air and make this source of energy more advantageous.
When these conditions are particularly favorable, the boiler will be stopped, and this second portion of air, the flow of which will possibly be increased, may form the only source of heat for the production of sanitary or industrial hot water and also possibly for heating premises.
It is to be noted also that by the expression "outside air" used above, it is not intended to designate only atmospheric air but, more generally, air which is outside the installation, i.e. outside the boiler part and the thermodynamic part thereof. In particular, it is not excluded that a part of this air (as a rule in a fairly small proportion) is foul and humid air extracted from the heated premises by controlled mechanical ventilation. The heat from the vapor due to human or animal breathing may then also be used by the heat pump(s) of the installation.
In brief, and whatever the exact embodiment chosen, the installation of the invention provides, in all circumstances, at all seasons and even at any moment in the day, an energy yield considerably higher and under better operating conditions than the installations of the prior art.
In general, it will be very advantageous although this does not form an obligatory characteristic of the invention to arrange, with the duct containing several independent evaporators which considered successively in the flow direction of the gases (air and water vapor and possibly combustion gases) are subjected to decreasing temperatures, that each evaporator is associated with a condenser in a compression heat pump heat circuit so that the difference in temperature between each evaporator and the condenser which is associated therewith is relatively reduced--of the order of 40° to 45° C.
With this arrangement, the difference in temperature between the evaporator and the condenser of each heat pump may be reduced to a large extent and so the thermodynamic efficiency of each of them considerably increased, with temperatures decreasing, not only for the evaporators but also for the condensers, in the flow direction of the gases and of the air in said discharge duct.
This complementary arrangement of the invention obviously requires additional investment in equipment, in relation to an installation which comprises only a single heat pump, with equality of thermodynamic source heating power, but the considerable increase in the efficiency of each heat pump (an increase in efficiency of 50 to 100% may be reckoned on) forms the advantageous counterpart thereto, and it should furthermore be noted that the compressors may be all the less powerful and will be more flexible in use and more economic in upkeep than the large compressors, moreover in less general use.
The arrangement in question consisting in using several heat pumps operating at stepped temperatures presents furthermore and especially the very great advantage of considerably increasing the flexibility of operation of the thermodynamic part of the installation, by improving the determination and the distribution of the different flows of fluids used: in this discharge duct with respect to the temperature and the relative flows of the combustion gases from the boiler and of the outside air on the circuit of the evaporators; and at the condensers, i.e. heat exchangers with what was called above "the circuits for the circulation of the heat-carrying fluid and for the production of sanitary or industrial hot water".
As a complement to the above-defined arrangement whose essential advantages have just be enumerated, an installation in accordance with the invention may further be characterized in that the electric circuit supplying the compressors with current is associated with a control device arranged to prevent two or more compressors from absorbing at the same time the peak of starting current.
It may be any adequate device, particularly electronic. In any case, this complementary arrangement will avoid very heavy demands for current, which will make less constraining and less costly the installations for supplying electricity and for protecting the compressors as well as in certain cases the supply of electrical energy.
As for the construction of an installation in accordance with the invention, it will be advantageous for said duct for discharging the combustion gases from the boiler, in which are disposed the evaporator(s) of the heat pump(s) to be staggered axially in relation to the body of the boiler and to be extended downwards by a lower duct portion situated laterally in relation to said body, with or without spacing therebetween, this lower lateral part of the discharge pipe comprising the outside air intake(s) with their flow regulating means, filters, variable-speed fans or similar, duct for discharging condensates, or products used for cleaning the evaporators, possibly a manhole and other members or elements required for maintaining or inspecting said duct.
It can be seen that an installation in accordance with the invention will thus comprise two operationally distinct parts: the conventional boiler part, with fire-chamber and the thermodynamic part with its discharge duct (containing the evaporator(s) of the heat pump(s)), air intakes, fans and accessories. This embodiment has the merit of simplicity and will greatly facilitate the discharge of condensates and products possibly used for cleaning the evaporators, since these liquids will flow to the bottom of the lower lateral part of the discharge duct, away from the fire-chamber.
This arrangement enables in particular a very large quantity of outside air to be passed directly over the evaporators of the discharge duct without causing it to pass through the boiler part, by making it follow the by-pass formed by what was called above the lower part of the discharge duct, which avoids adversely affecting the volumetric efficiency of the fire-chamber.
The installation may further be arranged for said discharge duct to contain, extending over an essential part of its section, at least one baffleplate barrier or similar, substantially at its junction with the outlet of the combustion gases from the boiler. Thus the mixing between the combustion gases from the boiler (of course when this latter is operating) and the outside air introduced at the base of the discharge duct is homogenized and this before this gas current reaches the first evaporator.
In the preferential but not obligatory embodiment according to which the discharge duct contains several (at least two) evaporators, the installation may further be arranged for this duct to comprise at least one adjustable flow by-pass passage, for communicating the outside air intake(s) directly with the space separating two consecutive evaporators.
The means for regulating the flow in the by-pass may be a simple register. This arrangement of the invention gives further an additional regulating facility, particularly in enabling the operating temperature of an evaporator to be increased with respect to that or those which are downstream (by increasing the flow of the by-pass) or conversely.
Finally, one or more sprinkling ramps may be disposed in the discharge duct above the evaporator(s).
The evaporators and the baffleplate barriers may thus be conveniently cleaned. The cleaning water will be recovered at the bottom of the duct, with the condensates. Thus a considerable part of the installation may be cleaned without interrupting the operation thereof.
The above and other objects, features and advantages of the present invention will become apparent from the following description, given solely by way of non-limiting illustration, when taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically an installation in accordance with the invention, whose discharge duct, adjoining the boiler, contains a single heat pump evaporator; and
FIG. 2 shows schematically another installation in accordance with the invention, whose discharge duct contains two evaporators each forming part of a separate heat pump.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The installation of FIG. 1 comprises a boiler 1 having fire-chamber similar to that of a conventional boiler, provided with a combustible fluid intake 2 and a combustive air intake 3. The flows at 2 and 3 are adjustable and, as pointed out earlier, air intake 3 may be regulated to a flow substantially greater than that which would allow just stoechiometric combustion of the fuel. There is shown in the form of a coil 4 the hot water production circuit of the boiler, this water leaving by outlet 5 and returning to said circuit--cooled after use--through inlet 6.
The outlet 7 for the combustion gases of the boiler communicates with a discharge duct 8 itself communicating, at its upper part, with a smoke discharge shaft 9. From outlet 7, this duct 8 is extended downwards by a lower part 10 provided with a sloping flow bottom 11 and a liquid discharge outlet 12. (Reference 13 designates any discharge gully or spout). As can be seen in the figure, duct 8 is staggered in relation to the body of boiler 1 so that a part 10 may extend laterally at the side thereof and so that the whole of duct 8, from shaft 9 to bottom 11, may have the form of a straight and vertical column.
This column or duct contains in its upper part an evaporator 14 forming with compressor 15, condenser 16 and a pressure reducer 17, a compression heat pump circuit, this circuit having passing therethrough a refrigerating fluid, for example freon, and operating in a well-known cycle to take heat from evaporator 14 and restore it to condenser 16. The lower lateral part 10 of discharge duct 8 is provided furthermore with an intake 18 for humid outside air, filtered at 19 and drawn into the duct by a fan 20 (means for regulating the air flow have not been shown; a multispeed fan may be used).
At the level at which outlet 7 for the combustion gases from the boiler emerges into duct 8, this latter comprises a baffleplate barrier 21 serving to homogenize the mixing of these gases and the air introduced at 18. Finally, duct 8 comprises above evaporator 14 a sprinkling ramp 22 able to operate intermittently for cleaning the evaporator and the baffleplates. The water or other cleaning product, as well as the condensates coming from the condensation on evaporator 14 of the water vapor contained in the combustion gases and in the humid outside air introduced at 18 into duct 8, may leave through outlet 12 after flowing over the sloping bottom 11.
As far as the outside circuits are concerned now, they may comprise a central heating circuit with hot water radiators (not shown) connected to the outlet 5 of the heating circuit 4 of the boiler by means of a pump 23 and a pipe 24 having a valve 25. The return circuit for the radiators comprises a pipe 26 with a valve 27 and communicating with the return inlet 6 of the boiler through the exchange volume 28 of condenser 16, a pipe 29 with a valve 30, and a distributor 31 also connected to outlet 5 by piping 32. Pipe 26 is also connected to pipe 29, downstream of valve 30, by piping 33 having a valve 34. Furthermore, piping 35 having a valve 36 connects pipe 24, downstream of valve 25, to pipe 26, downstream of valve 27 (having regard to the flow direction of the water shown by arrows).
These external circuits may comprise furthermore a circuit for the production of sanitary or industrial hot water. The installation comprises therefore an apparatus for producing hot water in the exchange volume, referenced at 37, to which cold water is brought at 38 and from which hot water leaves at 39. This apparatus comprises a first exchanger 40 connected to the exchange volume 28 of condenser 16 by a pipe 41 in which the water flows (in the direction of the arrows), possibly by means of a pump 42, and a second exchanger 43 forming a by-pass of the return pipe 26 of the central heating.
The installation which has just been described operates in the following way: when the heating of premises by central heating is required, valves 34 and 36 being assumed closed and valves 25, 27 and 30 open, pumps 23 and 42 are started up and the position of distributor 31 controlled automatically, for example depending on the temperature in the premises to be heated. The tepid return water of the central heating, in pipe 26, is at a temperature t 1 ; it is reheated in the exchange volume 28 of condenser 16 and leaves therefrom through pipe 29, at the temperature t 2 . If this temperature t 2 is insufficient for the central heating, distributor 31 directs all or part of the water flow from pipe 29 towards exchanger 4 of boiler 1. The water leaves therefrom at 5 at temperature t 3 and mixes with the water passing possibly through piping 32. The water thus obtained at the desired temperature t 4 (as a rule between the temperatures t 2 and t 3 ) is fed to pipe 24 for supplying the central heating, the circulation being provided by pump 23.
As for the sanitary or industrial hot water, it is obtained at 39 at temperature t 5 .
The heat for exchange volume 37 of the heating apparatus is provided at a high temperature by exchanger 40 and at a lower temperature by bypass 43. As can be seen in the drawing, the heat supplying the exchanger is wholly taken from the exchange volume 28 of condenser 16 (pipe 41--pump 42).
During this period of use of the installation, fuel for the boiler will only be used to the extent that the enthalpy of the air fed in at 18 is insufficient for providing the required heating energy, by the heat pump, to condenser 16. In any case, as was clearly indicated above, the invention allows the upper heating power of the fuel to be used, for the heat for vaporizing the water vapor contained in the smoke may be recovered on evaporator 14, which heat is added to the sensible heat (and to the total heat from the outside air taken).
It should be noted that if temperature t 5 of the water taken at outlet 39 is insufficient, the closing of valve 30 and the opening of valve 34 will enable the return water from the central heating to be passed directly to boiler 1, without preheating by condenser 16, which causes the temperature t 5 to be raised since then all the heat produced by the condenser will be used in exchange circuit 40.
During the periods when the central heating is not required, the circuit of the radiators may be isolated by closing valves 25 and 27 and opening valve 36 and the boiler may be stopped. Since the enthalpy of the outside air is maximum at these periods, it will be sufficient (possibly with an increase flow) for the production of sanitary or industrial hot water, with only the use of the heat pump.
In the above-described installation, which uses only a single evaporator 14, too high a temperature difference may be observed, especially in winter, between the evaporator and the condenser, which corresponds to lower efficiency of the heat pump. It may be observed moreover that the smoke and the air escaping through discharge shaft 9 still contain a little water vapor and are not yet at a sufficiently low temperature.
The installation may then be improved in accordance with the diagram of FIG. 2, by use of two evaporators (or several evaporators).
In this FIG. 2, some elements, piping or parts of the installation are identical or similar, disposed in the same way or having the same role respectively as the elements, piping or parts of the installation of FIG. 1; they are shown respectively with the same references, which avoids describing again the arrangement or the operation thereof.
In this FIG. 2, there are shown at 14a and 14b two evaporators disposed in discharge duct 8. The lower evaporator 14a will operate of course at a higher temperature than upper evaporator 14b; these evaporators form part respectively of two separate heat pump circuits similar to that of FIG. 1, and whose elements have been shown by the same references to which the letter a has been added for the lower heat pump and the letter b for the upper heat pump. Similarly, there is shown at 21a a baffleplate barrier disposed in the same position as barrier 21 of FIG. 1, and by 21b a baffleplate barrier disposed between the two evaporators.
This second barrier is located at the level of the output of a lateral by-pass duct 44 equipped at its inlet with a flow-regulating flap 45 and which enables, as already pointed out, the proportions of the outside air to be regulated between the two evaporators, to adjust their operating temperature. On the other hand, to show that the installation may be more powerful than the preceding one, and that it may require a larger outside air flow, there is shown in FIG. 2 two air intakes 18, two filters 19 and two fans 20, for example also variable-speed fans.
As for the outer central heating and hot water production circuits, a complete analogy can be observed with the corresponding circuits of FIG. 1. However, a division of the functions is noticed between the exchange volumes 28a and 28b of condensers 16a and 16b of the two heat pumps: the first 28a serves in principle solely as a heat source for exchanger 40 of the hot water production apparatus, for it supplies water at a very high temperature, whereas the second 28b producing a lower temperature only serves for preheating the return water of the central heating before passing into the boiler. Communication may however be established between the exchange volume 28a and circuit 24-29 by means of a circuit 46 having valves 47 and 48.
It is also to be noted, as a particular characteristic of this embodiment, that the two compressors 15a and 15b are associated with an electronic control circuit 49 adapted to prevent simultaneous starting, so as to limit the current consumption peaks.
With these arrangements there may be provided approximately for evaporator 14a a temperature of 20° C., for condenser 16a a temperature of 65° C., for evaporator 14b a temperature of 0° to 5° C. and for condenser 16b a temperature of 40° to 45° C., which allow an excellent yield for each of the two heat pumps to be obtained by limiting the difference in temperature between the evaporator and the condenser of each of them.
It should also be noted that the air fed into one of the inlets 18 may come from a source different from that of the air fed into the other inlet; for one, it may be for example outside air and for the other air coming from heated premises, or else from premises for agricultural or industrial use producing large amounts of vapor. The flows at these two inlets may moreover be adjustable independently one of the other.
For the essential in any case the installation of FIG. 2 will operate according to the same principles as that of FIG. 1.
It is apparent that within the scope of the invention, modifications and different arrangements can be made other than are here disclosed. The present disclosure is merely illustrative with the invention comprehending all variations thereof.
In particular there may be provided, for the outside central heating and sanitary or industrial hot water production circuits, other schemes than those of FIGS. 1 and 2. Particularly, in the case of FIG. 2, where two heat pumps are used, it could be arranged for the two exchange volumes 28a and 28b of the condensers to be connected in series between pipes 24 and 29, instead of being connected to separate circuits.
Similarly, as far as discharge duct 8 is concerned it could be arranged horizontally and not vertically, in particular if, as for the boilers of blocks of flats, the height of the premises is limited with a high demand for heating power.
Finally of course the use of several boilers may be combined in different ways with the use of several discharge ducts equipped with evaporators and the proportions of the different heating flows from the boiler(s) and the outside air may be regulated each time at will.
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A central heating and/or hot-water production installation of the type using at least one source of conventional energy of the liquid or gaseous fuel kind and at least one heat pump thermodynamic heat source particularly of the compression heat cycle kind.
In this installation the evaporator(s) of the heat pump(s) are situated in a duct for discharging the combustion gases from the boiler and, in conjunction with this duct, there are provided one or more outside air intakes having flow-adjustment means, upstream of said evaporator(s).
Principal applications: heating industrial, agricultural or living premises, etc. and production of sanitary or industrial hot water.
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FIELD OF THE INVENTION
This invention relates generally to submergible pumping apparatus for use in oil and like wells. More particularly, the invention is concerned with submergible pumping apparatus that includes a positive displacement pump and which is suited for use in deep wells yielding small volumes of fluid. For example, the equipment may be used effectively in wells with casing diameters of about 41/2 inches and in wells producing under 250 barrels per day.
BACKGROUND OF THE INVENTION
Four artificial lift systems commonly used in deep wells of low output are: beam pump systems; gas lift; submergible centrifugal pump systems; and hydraulic pump systems.
Major components of a beam, or sucker rod, pump system are a surface mounted reciprocating beam unit, a sucker rod string, and a downhole pump. The surface unit is the largest expense item in the system, and the expense increases as the pumping depth and flow rate increases. A considerable amount of preventive maintenance is required in order to maintain the system operational, since the moving parts need lubrication, and the system includes a stuffing box requiring periodic tightening to ensure good sealing of the sucker rod at the surface. Also, with this system, as the rod string increases in length, it tends to stretch and contract during a greater portion of the stroke, thus reducing the efficiency of the system.
Gas lift is a relatively simple and reliable method for obtaining lift in a well. It is accomplished by injecting gas into the well at predetermined depth(s), either continuously, to lower the pressure of the formation so that the fluid will flow freely, or intermittently, at a high instantaneous rate for a short time, to surface columns of fluid at regular intervals. There is, however, a sharp increase in power required per barrel of fluid produced at rates below 250 barrels per day, although this is influenced, to an extent, by tubing size. The gas lift technique also requires a source of gas which may not be present at a well in the required quantities.
Submergible centrifugal pumping systems generally consist of an electric motor, a motor protector, a centrifugal pump (usually having multiple stages) and frequently a gas separator at the pump intake. Traditionally, these systems have been best applied in wells of high output (in excess of 250 BPD) at depths up to 15,000 feet. Centrifugal pumps tend to become inefficient at low flow rates, and difficult to produce when the openings in the stages become narrow slits designed to pump at low flow rates.
Hydraulic oil well pumping systems generally consist of a surface pump and filtration system which supplies high pressure clean fluid to a downhole hydraulically driven reciprocating pump. With these systems, high pressure power fluid at the surface can present a fire hazard in case of a leak. Further, in many cases, the system requires an extra tubing string for the flow of well fluid to the surface, and this can be a major cost item. Due to the separation of the donwhole pump from the surface fluid supply, the amount of energy stored in compression of the fluid and expansion of the supply line can be considerable. If the downhole pump control valve is not designed to handle this fluid in a no-load condition, the pump may reciprocate too rapidly, resulting in premature failure. This necessitates a complex screening valve.
The present invention provides alternative downhole pumping apparatus that is more satisfactory than traditional systems, particularly in deep wells (for example, deeper than 5,000 feet) that have low output, i.e., lower than 250 barrels per day.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention, a self-contained downhole pumping unit includes a reciprocating positive displacement piston-operated pump, a reservoir for power fluid to operate the pump, a motor-driven pump for supplying high pressure power fluid from the reservoir to the piston-type pump, and a control valve for directing the power fluid alternately to opposite sides of the power cylinder of the piston-type pump and returning power fluid to the reservoir.
Preferably, the piston-type pump includes a pair of pump plungers connected to the power piston on opposite sides thereof, and which alternately take in and discharge well fluid as the piston reciprocates to provide a double-acting effect. The plungers may operate in opposed pump chambers, each having inlet and outlet valves for fluid being pumped. Conveniently, the outlets of the respective chambers connect into a common pump discharge fitting.
The motor-driven pump for supplying power fluid to the power piston may, for example, comprise a known form of rotary positive displacement pump, such as a gerotor pump, and this may be driven, for example, by a conventional submergible motor.
The control valve may conveniently take the form of a spool valve having a valve rod formed as a section of the main piston-plunger assembly, and a tubular spool surrounding the rod and contained in a valve housing. The spool and housing may have suitable passages and the like for providing circulation of power fluid from the motor-driven pump alternately to opposite sides of the power piston dependent on the position of the valve rod and spool, whereby movement of the piston itself is effective to change the position of the valve (by movement of the valve rod) to effect stroke reversal.
Additional features of the invention will become apparent from the following description and claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1A is a diagrammatic elevational view of submergible pumping apparatus in accordance with the invention with components of the apparatus shown in positions occupied when a piston-plunger assembly thereof is substantially at the top of an upstroke;
FIG. 1B is a view similar to FIG. 1A with the components shown in positions occupied when the piston-plunger assembly is at the commencement of a downstroke;
FIGS. 2A-2D are longitudinal cross-sectional views of a control valve for the apparatus and showing different valve component positions during a pumping cycle;
FIG. 3 is a block diagram illustrating the layout of the succeeding figures; and
FIGS. 4 to 10 are longitudinal cross-sectional views of parts of a practical embodiment of the pumping apparatus shown in FIGS. 1A and 1B, and which are intended to be placed end to end in the manner shown in FIG. 3 to illustrate the complete apparatus. In FIGS. 4 to 10, the apparatus is shown on its side; and for ease of understanding, these sectional views illustrate the apparatus as seen at different cutting planes, as indicated in FIGS. 5A-8A. FIGS. 5A, 6A, 6B, 7A and 8A are cross-sectional views on the corresponding lines of FIGS. 5, 6, 7, and 8 showing the cutting planes on which FIGS. 5, 6, 7, and 8 are drawn.
DESCRIPTION OF PREFERRED EMBODIMENTS
The general principles of the invention will be described initially with reference to FIGS. 1A and 1B. These figures depict, diagrammatically, submergible pumping apparatus in which a double-acting positive displacement piston-type pump A is operated by power fluid circulated through the pump from a reservoir B by means of a rotary positive displacement pump C (in the form of a gerotor pump), driven by a conventional submergible electric motor D. A control valve E produces stroke reversal of the main power piston 10 of pump A.
Power piston 10 operates in a power cylinder 12 and forms part of a piston-plunger assembly that also includes an upper plunger 14, a lower plunger 16, and a valve rod section 18, forming part of the control valve E, as will be described. Upper plunger 14 operates in an upper plunger chamber (production cylinder) 20, and lower plunger 16 operates in a lower plunger chamber (production cylinder) 22. Upper chamber 20 communicates with the exterior of the pumping apparatus via an upper fluid inlet passage 24 having an upper inlet check valve 26. Lower chamber 22 likewise communicates with the exterior through a lower fluid inlet passage 28 having a lower inlet check valve 30. The upper chamber has a fluid discharge passage 32 leading to a pump discharge fitting 34 through an upper discharge check valve 36. The lower plunger chamber similarly has a discharge passage 38 leading into a discharge riser 40 through a lower discharge check valve 42. Check valves 26, 36 and 30, 42 constitute check valve assemblies at the remote ends of the production cylinders 20 and 22. The discharge riser connects at its upper end with the pump discharge fitting.
Rotary pump C delivers working fluid from reservoir B to the control valve via duct 44; and from the control valve, the high pressure working fluid is diverted to one or other side of power piston 10 (dependent on the position of the valve) through one of ducts 46, 48. (The other of these ducts returns low pressure working fluid to the valve). Low pressure fluid from the control valve is returned to the reservoir through duct 50 and thence to the inlet of pump C through inlet passage 52. The reservoir includes an accumulator 54 to accommodate pressure fluctuations. Motor-driven pump C, reservoir B, and the associated components constitute drive means for pump A.
In FIG. 1A, the control valve is supplying high pressure power fluid from pump C to the lower end of cylinder 12, through duct 48, while low pressure power fluid from above the piston is returned to the reservoir through duct 46, valve E, and duct 50, so that the piston-plunger assembly is moving upwardly. In this condition of the apparatus, with plungers 14 and 16 moving upwardly in their respective chambers, well fluid (production fluid) is being drawn into lower chamber 22 through inlet 28 and valve 30, due to suction conditions in chamber 22, while conversely, well fluid from upper chamber 20 is being forced out into discharge fitting 34 through passage 32 and valve 36.
When piston 10 approaches the top of its stroke, valve rod section 18 attains a position in which it initiates a control valve shift producing reversal of the power fluid flow (as will be described in more detail hereafter) so that high pressure fluid from pump C is now supplied to the top of piston 10 through duct 46, while low pressure power fluid is returned from below piston 10 to the reservoir via duct 48, valve E, and duct 50. Accordingly, the piston-plunger assembly moves downwardly as indicated in FIG. 1B. In these conditions, well fluid is drawn into upper chamber 20 through inlet 24 and valve 26, while the well fluid in lower chamber 22 is discharged through passage 38 and valve 42 into riser 40.
As piston 10 reaches the bottom of its stroke, valve rod section 18 again initiates a reversal in the flow of the power fluid to provide the next upstroke of the piston-plunger assembly, so that the pumping cycle is repeated. Thus, with the apparatus fully charged, it will be apparent that well fluid is pumped through discharge fitting 34 continually on both upstrokes and downstrokes of the piston-plunger assembly.
The construction and operation of control valve E will now be described with reference to FIGS. 2A through 2D and FIG. 7, which show the valve on its side. In the illustrated configuration, the reservoir end of the pumping apparatus (the lower end) is considered to be to the right, and the power piston end of the apparatus (the upper end) is to the left. The cutting plane of FIG. 7 is at right angles to the cutting plane of FIGS. 2A to 2D.
Valve E comprises the aforementioned valve rod section 18, forming part of the reciprocating piston-plunger assembly, an axially reciprocating valve spool 56 in which rod section 18 slides, a housing or casing 58, fitting within the main housing member 62 of the pumping assembly (see FIG. 7), and in which the valve spool slides, and end seals 60 between the spool and housing.
High pressure power fluid from pump C is continuously supplied to valve E via a passage 64 in the valve housing (see FIG. 7) and which corresponds to the terminal portion of duct 44 in the diagrammatic representation shown in FIGS. 1A and 1B. Passage 64 communicates via a port 66 with a central annular groove 68 formed on the interior of the valve housing.
A left hand (upper) annular groove 70 on the interior of the valve housing communicates with a port 72 and passage 74 in the valve housing (FIG. 7). Passage 74 leads to the bottom end of cylinder 12 (FIGS. 1A and 1B) and corresponds to a part of duct 48. A right hand (lower) annular groove 76 on the interior of the valve housing communicates with a port 78 and passage 80 in the housing (FIG. 7). Passage 80 leads to the end of cylinder 12 and corresponds to a part of duct 46 shown in FIGS. 1A and 1B.
Valve housing 58 further includes a passage 82 (FIGS. 2A to 2D) for the return of low pressure power fluid to the reservoir, and ports, 84, 86 connecting passage 82 to the interior of the valve housing. Passage 82 corresponds to a part of duct 50 in FIGS. 1A and 1B. Additional constructional features of the control valve will become apparent from the ensuing description of its operation.
FIG. 2A shows valve spool 56 in the extreme left (upper) position, allowing high pressure power fluid from central groove 68 to communicate, via an external groove 88 in the valve spool, with upper groove 70, and hence the bottom end of cylinder 12, moving the piston 10 and thus valve rod section 18 to the left (upwardly). Low pressure power fluid from the upper end of cylinder 12, which is open to groove 76, through passage 80 and port 78 (FIG. 7) vents to the reservoir via a second external groove 90 in spool 56, port 86 and passage 82. Valve rod 18 in FIG. 2A has just reached a position where an actuation groove 92 in the rod opens a left (upper) vent hole 94 in the spool. This allows high pressure power fluid from groove 68 to flow via groove 88, a central vent hole 96 in the spool, a central internal spool groove 98 and a groove 92 to a left-hand actuating annulus 100 defined between an exterior shoulder 102 of the spool and left-hand seal 60. (It will be noted that the exterior of the valve spool has a chamfered portion leading from hole 94 to provide a lead in for high pressure fluid).
At the right-hand (lower) end, spool 56 has a right (lower) vent hole 104 which connects a right (lower) spool annulus 106 defined between an external spool shoulder 108 and right-hand seal 60, with a right (lower) venting groove 100 on the valve rod. In the position shown in FIG. 2A, groove 110 communicates with a right (lower) annular chamber 113 (shown in FIG. 7 but not shown in FIG. 2). Chamber 113 communicates with the reservoir as will also be described later.
In view of the above construction, when high pressure power fluid is admitted to the left-hand annulus 100, while right-hand annulus 106 is vented to the reservoir, valve spool 56 will move to the right (downwardly) toward the extreme right-hand position shown in FIG. 2B. As the spool approaches the extreme right-hand position, flow is increasingly restricted by the decreasing flow area through the chamfered portion of right-hand annulus 106, thus decreasing the impact at the end of the valve spool stroke with the chamfer providing a cushioning effect.
When the valve spool attains the FIG. 2B position, central groove 68 (the high pressure power fluid inlet from pump C) is connected, through groove 88, to groove 76, which itself communicates with the upper end of cylinder 12. Simultaneously, groove 70 (the connection from the lower end of cylinder 12) is connected with port 84 and passage 82 leading to the reservoir, via a further groove 112 on the exterior of the valve spool. Thus, stroke reversal of the main piston 10 is effected, and the piston-plunger assembly, including valve rod section 18 moves to the right (downwardly) toward the position shown in FIG. 2C.
When the valve rod section 18 has moved to the FIG. 2C position, groove 92 in the rod uncovers vent opening 104 in spool 56, thereby admitting high pressure power fluid from groove 68 to the right (lower) annulus 106, via groove 88, vent opening 96, groove 98, and groove 92. Simultaneously, a further groove 114 at the left (upper) end of valve rod section 18 uncovers left vent opening 94 and connects the left-hand annulus 100 to a left-hand (upper) annular chamber 116 (FIG. 7) which communicates with the reservoir as will be described. Thus, the valve spool 56 moves to the left, toward the extreme left-hand (upper) position shown in FIG. 2D. Impact of the valve spool is again cushioned by the chamfered section of left-hand annulus 100.
In the extreme left (upper) position of the valve spool shown in FIG. 2D, high pressure power fluid from pump C is again directed via grooves 68 and 70 to the lower end of cylinder 12, while the upper end of cylinder 12 is connected to the reservoir via grooves 76 and 90, port 86 and passage 82. Thus, the stroke of the piston-plunger assembly is again reversed, and valve rod section 18 moves to the left and returns to the FIG. 2A position. The entire cycle of valve operation and stroke reversal of the piston-plunger assembly may then be repeated.
Reverting to FIGS. 1A and 1B, it will be noted that the apparatus further includes upper and lower barrier chambes 120, 122 which embrace portions of the piston-plunger assembly between the respective plunger chamber 20 and 22 and the power fluid operational part of the apparatus (valve E and piston 10). The barrier chambers are, in use, each filled with clean fluid, which conveniently may be the same fluid as the power fluid, and their purpose is to provide a relatively clean barrier between parts of the apparatus in which relatively unclean well fluid circulates (chambers 20 and 22) and parts of the apparatus (valve E and piston 10) filled with clean power fluid, so as to avoid contamination of the power fluid with well fluid.
Plunger seals 124 are provided at the opposite ends of the respective barrier chambers, and the length of the barrier chambers relative to the length of stroke of the piston-plunger assembly is such that each of the seals wipes a different length of plunger. This enhances the barrier effect of the chamber arrangement and ensures that no surface defects will affect both sets of seals.
A practical form of pumping apparatus described above in principle will now be described in more detail with reference to FIGS. 3-10. It will be understood that FIG. 3 is a block diagram showing the layout of the succeeding figures, each of which shows a part of the pumping apparatus as indicated in FIG. 3. Further, FIGS. 4-10 may be positioned end-to-end in order to construct a composite view of the apparatus in its entirety. In FIG. 3 and FIGS. 4-10, the pumping apparatus is shown on its side, with its lower, inlet end (FIG. 4) to the right, and its upper, outlet end (FIG. 10) to the left. Also, the cutting planes of FIGS. 4-10 differ along the length of the pumping apparatus as indicated in FIGS. 5A to 8A, in order to obtain a better view of certain internal components of the apparatus. Description of the apparatus will commence at the lower, inlet end, FIG. 4. Like reference numerals to those used in the preceding figures are used, where practical, to denote like parts.
The inlet end of the pumping apparatus (see FIG. 4) includes a flanged inlet fitting 126 by which the apparatus may be connected to drive motor D (FIGS. 1A and 1B). To the outside of fitting 126 is secured a cylindrical housing member 128, forming a lower section of the main assembly housing. Parts 126 and 128 may, for example, have a screw connection with interposed O-ring seals, as shown. Within housing member 128 is situated the gerotor pump C for supplying high pressure working fluid to valve E and piston 10 as previously described. Pump C is a common form of positive displacement rotary gerotor pump, that is well known in the art, and will not therefore be described in detail. It includes an eccentric ring 130, end plate 132, manifold 134, and rotor 136. The end plate and eccentric ring may be secured to fitting 126 and suitably aligned by screws 138 and alignment pin 140. Rotor 136 may be keyed to a drive shaft 142 which is carried in fitting 126 and manifold 134 by sleeve bearings 144, 146. In use, shaft 142 will be coupled to the output shaft of motor D. A roller clutch 148 is interposed between fitting 126 and shaft 142 whereby the shaft can only be rotated in one direction suitable for proper operation of the gerotor pump. A shaft seal 150 is provided adjacent the roller clutch.
Motor D may be a constant speed or variable speed motor of any suitable submergible type known in the art. A change in speed of the drive motor changes the speed of reciprocation of the piston-plunger assembly, motor speed being almost directly proportional to the displacement of the reciprocating pumping apparatus.
To enhance the load-bearing qualities of bearings 144 and 146, these may be a hybrid hydrodynamic-hydrostatic design, wherein high-pressure fluid from the gerotor pump is allowed to penetrate between the shaft and bearings and operate in suitably shaped channels (not shown) which may be formed in the bearings at the shaft interface. Fluid from bearing 146 may also pass through the roller clutch and may then be returned to reservoir B by suitable passages 150', 152 formed in shaft 142 as shown.
Reservoir B occupies the volume of member 128 to the left of pump C, being separated from the pump by a seal plate 154. Manifold 134 includes a pump discharge 156 and a pump inlet 158. The discharge is connected to a tube 160 which corresponds to duct 44 in FIGS. 1A and 1B, and delivers high pressure power fluid from pump C to control valve E. Pump inlet 158 receives low pressure power fluid from reservoir B through a strainer 162 attached to plate 154 and an opening 164 in the plate. Accumulator 54 (see FIGS. 1A and 1B) communicates with pipe 160 through passage 168 in a mounting plate 170 that also supports strainer 162. The accumulator may be of a conventional gas-loaded diaphragm type.
Proceeding to FIG. 5, reservoir B terminates at its left (upper) end in a bulkhead assembly including a bulkhead member 172 and plate 174 located in the end of housing member 128. Tube 160, which includes a high pressure relief valve 176 terminates in bulkhead member 127. A passage 178 in the bulkhead member connects tube 160 to a passage 180 in the succeeding housing member 182, for the onward transmission of high-pressure power fluid from pump C to valve E and piston 10. Housing members 128 and 182 may have a screw connection as shown, or alternatively a flanged connection may be used.
Bulkhead member 172 further includes a passage 184 for the return of low pressure power fluid from valve E to reservoir B via a passage 186 in housing member 182 which corresponds in part to duct 50 in FIGS. 1A and 1B. Passages 180 and 186 respectively connect with passages 178 and 184 in the bulkhead member through openings in a seal plate 187. Passage 184 communicates with the interior of reservoir B via a filter 188 for the return of power fluid. The filter may be provided with a magnet (not shown) for attracting any solid metallic pollutants which may be present in the returning power fluid. Plate 174 may carry a sprung filter by-pass cylinder 190 through which returning fluid normally flows into the filter from passage 184. The bypass cylinder, however, may be moved away from its seat, against the spring action, to allow return fluid to bypass the filter in the event of a rise in return fluid pressure should the filter become clogged.
Referring now jointly to FIGS. 5 and 6, housing member 182 has a longitudinal through-bore 192 with an enlarged section at its right-hand (lower) end in which it accommodates a lower well fluid inlet and discharge check valve assembly 194. Adjacent assembly 194, bore 192 accommodates a liner 195, which defines the lower plunger chamber 22 (FIGS. 1A and 1B) and lower plunger 16. At its right (lower) end, plunger 16 may be provided with a series of rings 196 (10 rings may be provided, for example) to form a seal between the plunger and liner 195, if a steel plunger is used. For a ceramic plunger, however, the rings may be omitted. Chamber 22 communicates with the interior of assembly 194.
Internally, assembly 194 contains the lower inlet check valve 30 and lower discharge check valve 42 (FIGS. 1A and 1B). The internal construction of assembly 194 is not visible in FIG. 5 but is similar to that of the corresponding upper assembly for the inlet and discharge of well fluid (FIG. 10) where the internal constructional details are shown.
Well fluid is drawn into assembly 194 through a transverse passage 198 in housing member 182, which communicates with an inlet manifold 200 of assembly 194. Manifold 200 has circumferential inlet ports 202 which communicate with plunger chamber 22 via the lower inlet check valve (not shown). Passage 198 corresponds to well fluid inlet 28 in FIGS. 1A and 1B. On left-to-right movement (downstrokes) of plunger 16, well fluid from chamber 22 is discharged through assembly 194 via the lower discharge check valve (not shown), discharge manifold 204, and communicating passages formed in housing member 182 including a lengthwise passage 206 corresponding to the lower section of the discharge riser 40 of FIGS. 1A and 1B.
O-rings 208 seal the assembly 194 in bore 192. Between the two right-hand (lowermost) rings, a vent groove 210 is provided which communicates with the exterior of the assembly through a vent passage 212 in member 182. The purpose of the vent groove and passages is to prevent high pressure pumped well fluid from leaking at the joints of seal plate 186 into the clean power fluid passages.
Referring specifically to FIG. 6 the left (upper) end of housing member 182 may have a screw-threaded or other connection to succeeding housing member 62 already referred to in connection with FIG. 7. Adjacent the left (upper) end of liner 195 is a liner spacer 216 with a tapered bore facilitating insertion of plunger 16. A passage 218 in spacer 216 communicates with further vent ports 220 and 222 in housing member 182. The vent ports provide further protection against high pressure well fluid, which may for example leak into the spacer passage past the plunger rings 196.
Adjacent spacer 216 is situated a seal plate 224 carrying a pair of lip seals 226 which engage the plunger and correspond to seal 124 at the lower end of barrier chamber 122 in FIGS. 1A and 1B. A flanged ring 228 abuts seal plate 224 and is secured, as by welding, to the right (lower) end of a cylinder 230. The left (upper) end of cylinder 230 is similarly secured to a further ring 232. Cylinder 230 has an annular clearance around plunger 16, which in use is filled with clean fluid, and defines the lower barrier chamber 122 described in relation to FIGS. 1A and 1B. Ring 232 carries seal plates 234, 236 with lip seals 238 which engage the plunger and correspond to seal 124 at the upper end of barrier chamber 122 in FIGS. 1A and 1B. The purpose and function of the barrier chamber and seals have already been described.
Passage 180 in housing member 182 connects with a tube 240 extending through housing member 62 for the onward transmission of high pressure power fluid from pump C to control valve E. Similarly, passage 206 connects with a tube 242 for the onward transmission of pumped well fluid from plunger chamber 22. Annular space 244 in housing member 62 surrounding cylinder 230 is, in operation, filled with low pressure power fluid returning from valve E to the reservoir. Space 244 communicates with power fluid return passage 186 in housing member 182 (FIG. 5) via an opening 246 in ring 228 (see FIG. 6B).
Ring 232 is secured at its left (upper) end to a retaining plate 248 to which is connected, as by welding, the right (lower) end of a cylinder 250. The left (upper) end of cylinder 250 is similarly connected to a further retaining plate 252 (FIG. 7) attached to valve housing 58. Plunger 16 is connected, for example, by a screw 254 to valve rod section 18.
Cylinder 250 defines internally thereof the annular chamber 113 already referred to in the description of control valve E. In use, chamber 113 receives low pressure power fluid from valve E for return to the reservoir. Ports 256 in cylinder 250 connect annular chamber 113 to an outer annular chamber 258, which in turn communicates with chamber 244 via grooves 260, 262 in plate 248 and ring 232 (see FIG. 6A).
Proceeding to FIG. 7, the control valve structure has already been described and will not be repeated, save for parts of the valve which are not readily apparent in FIG. 7. Thus, ports 84, 86 and passage 82 in the valve housing 58 (see FIGS. 2A-2D) for the return of low pressure power fluid from the valve to the reservoir are not shown in FIG. 7. The positions of ports 84 and 86, however, have been indicated in dotted form, and these communicate with one of the pair of lengthwise channels 260, 262 formed in the valve housing (see FIG. 7A). The channels communicate at their right (lower) ends with annular space 258 via suitable openings in plate 252.
At its left (upper) end valve housing 58 is attached to a plate 264, to which is connected as by welding, a cylinder 266. Passages 74 and 80 in the valve housing provide communication between the control valve and opposite ends of the cylinder 12, respectively, as previously described, and connect, respectively, to tubes 268 and 270. As shown in FIG. 8, the left (upper) end of cylinder 266 is attached to a retainer plate 272.
Internally, cylinder 266 defines the upper annular chamber 116, previously referred to, which receives low pressure power fluid from the control valve for return to the reservoir. Ports 274 in cylinder 266 connect chamber 116 to an outer annular space 276 which communicates with the low pressure power fluid grooves 260, 262 (FIG. 7A) in the valve housing via suitable openings (not shown) in plate 264.
Plate 272 connects to the right (lower) end of a cylinder housing 278, which defines the main power cylinder 12. Valve rod section 18 is connected, e.g., via screw 280, to power piston 10, the opposite (upper) end of which is similarly connected to upper plunger 14. The right (lower) end of cylinder 12 is sealed by a lip seal 282 engaging valve rod section 18, and carried by a seal plate 284 trapped between plate 272 and a flange in cylinder housing 278.
Power piston 10 may comprise a main steel body part 286 externally grooved to receive a central wear ring 288, lip seals 290, seal retaining rings 292, and snap rings 294. Tube 268 communicates with the lower end of cylinder 12 via a passage 296 formed in the cylinder housing, and tube 270 communicates with the upper end of the cylinder (see FIG. 9) via a corresponding passage 298.
As shown in FIG. 8, piston 10 may partially cover outlet ports 297, so as to provide a hydraulic cushion preventing overstroking. A similar action may occur at the opposite end of the stroke. The piston stroke may, for example, be about 8 inches; and to ensure against gas lock, the compression ratio may be about 15 to 1.
The left (upper) end of cylinder housing 278 is connected to a ring 300 (FIG. 9) which carries a seal retaining plate 302 with lip seals 304 which engage plunger 14 to seal the upper end of cylinder 12 and also form seal 124 (FIGS. 1A and 1B) of upper barrier chamber 120. A cylindrical member 306 is connected, as by welding, to ring 300 at its right (lower) end and to a flanged ring 308 at its left (upper) end. Barrier chamber 120 is formed by the annular space between plunger 14 and member 306 and is, in use, filled with barrier fluid as previously described.
Adjacent ring 308 is a further seal retaining plate 310 with lip seals 312 which correspond to the upper seal 124 (FIGS. 1A and 1B) for the barrier chamber 120. Ring 308 mates with an upper cylinder member 314 having a liner 316 which defines upper plunger chamber 20. Plunger 14 has seals 318 like seals 196 of the lower plunger (FIG. 5). Between liner 316 and seal retaining plate 310 is a liner spacer 320 corresponding to spacer 216 (FIG. 6) of the lower plunger chamber. Spacer 320 has a passage 322 which communicates with a passage 324 in cylinder member 314 and thus with upper well fluid inlet 24 (FIGS. 1A and 1B and FIG. 10) to provide a vent for well fluid equivalent to vent 220 in the lower plunger chamber.
FIG. 9 also shows the continuation of tube 242 (see FIG. 6) which carries pumped well fluid from the lower plunger chamber to the discharge fitting 34 of the assembly (FIGS. 1A and 1B and FIG. 10). Tube 242 connects with a passage 326 in housing 314, and passage 326 leads into a manifold 328 (FIG. 10) at the base of the discharge fitting. Further evident in FIG. 9 is sheathed electrical wiring 330 (see also FIG. 10) which may extend through the assembly for activating the motor D, where, for example, the assembly is to be used in a relatively narrow well casing. Suitable openings and seals may be provided for the wiring down the length of the pumping assembly in the various plates, bulkheads and the like. General reference 330 is used to indicate the wiring where it is shown in the various figures. As an alternative, for example, in larger diameter wells the wiring for motor D may be external to the pumping apparatus.
Referring now specifically to FIG. 10, this shows the upper well fluid inlet and discharge check valve assembly 332 in cross section. As noted previously, assembly 332 is similar to the equivalent lower assembly 194 (FIG. 5). Assembly 332 contains both the upper inlet check valve 26 and the upper discharge check valve 36 (see also FIGS. 1A and 1B). Considering firstly the inlet valve arrangement, well fluid inlet 24 communicates with a manifold 334 having circumferential ports (not shown but equivalent to ports 202 in the lower assembly). The ports, in turn, communicate with circumferentially spaced passages 336 each terminating in a valve seat 338. A steel ball 340 sits on each valve seat and constitutes a movable valve element urged toward the seat by a sprung cage 342. A coil spring 344 for the cage acts against a washer 346 trapped against the end of liner 316. There are preferably three passages 336 and balls 340, equally spaced circumferentially so as to equalize the pressure forces. It will be evident that when plunger 14 is moving to the right (downwardly), creating suction in chamber 20, balls 340 can move off their seats against the spring action, so as to admit well fluid to the chamber; but when the plunger is moving to the left (upwardly) to pump fluid from the chamber, balls 340 are pushed against their seats so as to block the fluid inlet to chamber 20.
The discharge check valve 36 includes a single ball 346 controlling a central axial passage 348 leading from chamber 20. Ball 346 is held in a spider fitting 354 which includes a spring assembly 350 urging the ball against a seat 352 at the end of passage 348. Fitting 354 includes circumferentially spaced lengthwise passages 356 which communicate with passage 348 when ball 346 is moved away from its seat against the spring pressure. This occurs on pumping strokes of plunger 14, whereby well fluid is discharged from chamber 20 into manifold 328 via passages 348 and 356, and then into discharge fitting 34.
Manifold 328 and assembly 332 are held against the end of liner 316 by a Bellville washer 358 trapped between the manifold and the discharge fitting. The end of the discharge fitting may be connected to a head fitting 360, which may itself be connected to discharge tubing.
It will be appreciated that the pumping apparatus shown in detail in FIGS. 4-10 operates in exactly the manner described with reference to FIGS. 1A, 1B and FIGS. 2A to 2D. As previously indicated, the pumping apparatus is considered particularly effective for use in deep wells of low output.
While only preferred embodiments of the invention have been described herein in detail, the invention is not limited thereby and modifications can be made within the scope of the attached claims.
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Submergible pumping apparatus for use in an oil or other well comprises, in a self-contained downhole unit, a double-acting reciprocating positive displacement pump for pumping well fluid, a reservoir containing power fluid for operating the double-acting pump, a rotary motor-driven positive displacement pump for supplying power fluid under pressure from the reservoir to operate the reciprocating pump, and a control valve for properly directing high pressure power fluid from the rotary pump to the reciprocating pump and from the reciprocating pump back to the reservoir so as to provide stroke reversal of the reciprocating pump.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Application No. 61/598,086, filed Feb. 13, 2012, which is hereby fully incorporated by reference.
TECHNICAL FIELD
This disclosure relates to using infrared detection to detect the position of a substrate that is being transported within a substrate processing system such as e.g., a vapor transport deposition system.
BACKGROUND
Photovoltaic devices such as e.g., photovoltaic modules or cells can include semiconductor and other materials deposited over a substrate using various deposition systems and techniques. One example is the deposition of a semiconductor material such as cadmium sulfide (CdS) or cadmium telluride (CdTe) thin fihns over a glass substrate using a processing chamber such as e.g., a vapor transport deposition (VTD) chamber.
During the processing, it is important for a system controller to know the positions of the substrates within the processing chamber to ensure, among other things, that there is proper spacing between the substrates and to know what process the substrates are currently undergoing. Typically, the edge position of each substrate is checked before the substrate is placed into the chamber. This gives the controller an initial point to track the substrate as it progresses through the chamber. Unfortunately, the actual substrate position can be shifted/offset from the controller's calculated substrate position at different times during the process. For example, a position shift can occur as the substrate is entering the processing chamber due to the high speed transfer used to place the substrate into the chamber. Other shifts between the actual and controller calculated positions can occur due to speed changes arising from material build up on the rollers transporting the substrates.
Differences between the controller calculated substrate position and the actual substrate position can adversely impact the processing or lead to mishandling of the substrates. Thus, processing systems will incorporate edge detection mechanisms, portions of which reside within the chamber. Each detection mechanism includes a laser that emits a light beam through a chamber window to a reflector located within the chamber at a point somewhere along the substrate travelling path. The reflector reflects the beam back to a detector. When the substrate passes by, the beam is interrupted, signaling the presence of the substrate. The controller can use this information to try to compensate for the new substrate position.
The above detection mechanism has some shortcomings and relies on several factors to be successful, some of which cannot be controlled. For example, the chamber windows must be clean to allow the light beam to enter the chamber, be reflected back and detected. Keeping the windows clean will require additional maintenance and down time, which is undesirable. Moreover, the laser, reflector and detector must remain properly aligned, which is difficult to achieve due to the processing and vibrations within the chamber. Furthermore, there is the general need to prevent the light beam path from being blocked or disrupted by anything other than the substrate to prevent false detections, which is an onerous task.
Accordingly, there is a need and desire for a better way to detect a position of substrate that is being transported within a substrate processing chamber.
DESCRIPTION OF DRAWINGS
FIG. 1 shows a system for detecting substrate position within a first portion of a processing chamber in accordance with an embodiment of the invention.
FIG. 2 shows an example detector output from the detector illustrated in FIG. 1 .
FIG. 3 shows the FIG. 1 system detecting substrate position within a second portion of the processing chamber in accordance with an embodiment of the invention.
FIG. 4 shows an example detector output from the detector illustrated in FIG. 3 .
FIG. 5 shows another example system in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
FIG. 1 shows a system 10 for detecting substrate position within a first portion 20 a of a processing chamber (hereinafter “chamber portion 20 a ”) in accordance with an embodiment of the invention. In the example embodiment, the chamber portion 20 a is VTD chamber included within a VTD processing system; it should be appreciated, however, that the system 10 and chamber portion 20 a can be any processing system or chamber that utilizes physical vapor deposition, chemical vapor deposition, sputtering or the like. In the illustrated embodiment, the substrate 28 is a glass sheet and the chamber portion 20 a is used for one or more processes needed to prepare thin film photovoltaic devices such as e.g., thin film photovoltaic modules or cells. The illustrated chamber portion 20 a includes a first set of heaters 22 , second set of heaters 24 and rollers 26 . It should be appreciated that other pieces of equipment often found in a processing chamber (e.g., the equipment required to deposit materials) are not shown for clarity purposes. In the illustrated embodiment, the substrate 28 is transported through the chamber via the rollers 26 in the direction of the substrate flow arrow.
The chamber portion 20 a operates at a sufficient temperature (e.g., 600° C.) that can emit detectable infrared radiation. In accordance with the disclosed principles, the infrared radiation from the chamber portion 20 a will be detected from outside the chamber, providing advantages discussed below in more detail. As such, the system 10 also comprises at least one infrared detector 30 externally mounted to the chamber portion 20 a . In a desired embodiment, the detector 30 is mounted on a window of the chamber portion 20 a with a focusing lens and wave filter pointed into the chamber. The detector 30 will have a “line of sight” into the chamber portion 20 a at a point along the substrate flow path. By mounting the infrared detector 30 in this manner, the quantity of infrared radiation from within the chamber portion 20 a at the “line of sight” can be detected and reported to a controller 50 as e.g., a varying output voltage. As is discussed below in more detail, the controller 50 will input the output voltage from the detector 30 and use the voltage to determine the location of the substrate 28 , one of its edges or gaps between substrates 28 . The controller 50 can use the determined location(s) to control, among other things, the rollers 26 to adjust the substrate's 28 position.
It is desirable to place the detector 30 at points where the substrate's 28 temperature will be different from the background temperature (i.e., temperature of the heaters 22 , 24 ) within the chamber portion 20 a . In the illustrated embodiment, the background temperature within the chamber portion 20 a is much hotter than the temperature of the substrate 28 . This condition may arise e.g., when a newly inserted substrate 28 has not undergone any processing within the chamber portion 20 a , or has undergone processing at a lower chamber temperature. As is explained below with reference to FIGS. 3 and 4 , it is also possible for the background temperature to be cooler than the temperature of the substrate 28 . According to the FIG. 1 example, the heaters 22 , 24 are e.g., 600° C., causing the background temperature to be at least 600° C., and the substrate temperature is e.g., less than 400° C.
Referring also to FIG. 2 , when gaps between substrates 28 are within the “line of sight” of the infrared detector 30 , the detector 30 will output a voltage within a certain voltage range corresponding to the background temperature. When the substrate 28 is within the “line of sight” of the infrared detector 30 , the detector 30 will output a voltage within a certain lower voltage range (compared to the background detection) corresponding to the cooler temperature of the substrate 28 . The differences between the two voltage ranges can be used to detect trailing and leading edges of substrates 28 .
For example, after the entire substrate 28 passes by the detector 30 , there will be an abrupt rise in the detector's 30 output voltage due to the detection of the much higher background temperature. This spike in the output voltage, corresponding to the spike in detected temperature, can be used as a signal that a substrate edge was just detected. In FIG. 2 , the rightmost portion of a spike indicates that a trailing edge of a substrate 28 has just completely passed the detector 30 while the leftmost portion of the same spike corresponds to a leading edge of a substrate 28 that has just come into the “line of sight” of the detector 30 . The exact position of the edges is determined from the location of the detector 30 . As can be seen, a gap length between substrates can also be computed from the same information illustrated in FIG. 2 .
The disclosed principles can also be used to detect whether the substrate 28 has been improperly rotated or skewed from its intended position within the chamber portion 20 a . It is possible for the substrate 28 to rotate or shift from its intended position. Thus, the detection of a gap or edge of the shifted substrate 28 may not represent the “true” gap or orientation of the substrate 28 . Accordingly, the chamber portion 20 a could include multiple detectors 30 at the same point (separated by a known distance) along the substrate path (see e.g., detectors 130 a , 130 b in FIG. 5 ). Having detections from two different detectors, separated by a known distance, the controller 50 will be able to use the output voltages from the detectors to determine if a plate was rotated or skewed. It should be appreciated that the controller 50 may also be able to detect a skewed or rotated substrate using the output voltage from one detector 30 . For example, if the controller 50 detects a gradual change in output voltage, instead of the abrupt changes illustrated in FIG. 2 , the controller 50 can determine that something is wrong with positioning of the substrate 28 .
FIG. 3 shows the system 10 detecting substrate position within a second portion 20 b of the processing chamber (hereinafter “second chamber portion 20 b ”) in accordance with an embodiment of the invention. Similar to FIG. 1 , an infrared detector 30 is externally mounted to the second chamber portion 20 b . In a desired embodiment, the detector 30 is mounted on a window of the second chamber portion 20 b with a focusing lens and wave filter pointed into the chamber. The detector 30 will have a “line of sight” into the second chamber portion 20 b at a point along the substrate flow path. As such, the quantity of infrared radiation at the “line of sight” can be detected by the detector 30 and reported to the controller 50 as e.g., a varying output voltage. The controller 50 will input the output voltage from the detector 30 and use the voltage to determine the location of the substrate 28 , one of its edges or gaps between substrates 28 . The controller 50 can use the determined location(s) to control, among other things, the rollers 26 to adjust the substrate's 28 position.
It is desirable to place the detector 30 at points where the substrate's 28 temperature will be different from the background temperature (i.e., temperature of the heaters 22 , 24 ) within the second chamber portion 20 b . In the illustrated embodiment, the background temperature within the second chamber portion 20 b is much cooler than the temperature of the substrate 28 . This condition may arise after the substrate 28 has undergone some processing and is about to undergo different processing at a lower chamber temperature. According to the FIG. 3 example, the heaters 22 , 24 are e.g., less than 600° C., causing the background temperature to be less then 600° C., and the substrate's 28 temperature is e.g., greater than 600° C.
Referring also to FIG. 4 , when gaps between substrates 28 are within the “line of sight” of the infrared detector 30 , the detector 30 will output a voltage within a certain voltage range corresponding to the cool background temperature. When the substrate 28 is within the “line of sight” of the infrared detector 30 , the detector 30 will output a voltage within a certain higher voltage range (compared to the background detection) corresponding to the higher temperature of the substrate 28 . The differences between the two voltage ranges can be used to detect trailing and leading edges of substrates 28 .
For example, after the entire substrate passes by the detector 30 , there will be a drop in the detector's 30 output voltage due to the detection of the much cooler background temperature. This drop in the output voltage, corresponding to the drop in detected temperature, can be used as a signal that a substrate edge was just detected. In FIG. 4 , the rightmost portion of the voltage drop indicates that a trailing edge of a substrate 28 has just completely passed the detector 30 while the leftmost portion of the same drop corresponds to a leading edge of a substrate 28 that has just come into the “line of sight” of the detector 30 . The exact position of the edges is determined from the location of the detector 30 . A gap length between substrates can also be computed from the same information illustrated in FIG 4 . Moreover, as mentioned above, the controller 50 will be able to determine if a substrate has been rotated or skewed from its intended orientation (as discussed above).
FIG. 5 illustrates another system 110 constructed in accordance with the disclosed principles. The system 110 comprises a plurality of infrared detectors 130 a , 130 b, 130 c , 130 d externally mounted to windows of a processing chamber 120 . As with the other detectors 30 ( FIGS. 1 and 3 ), the illustrated detectors 130 a , 130 b , 130 c , 130 d will have a “line of sight” into the chamber 120 at points where it is desirable to detect the presence or absence of a substrate or a substrate edge or whether the substrate has been improperly rotated. It should be appreciated that the system 110 could use more or less than three infrared detectors 130 a , 130 b , 130 c , 130 d depending upon the application, and that the disclosed principles should not be limited to a particular number of detectors used.
Voltage outputs from the infrared detectors 130 a , 130 b , 130 c , 130 d are input into a controller 150 . The controller 150 will monitor the input voltages to detect the positions of substrates within the chamber 120 and, if necessary, adjust controls to slow down or speed up portions of the process. One example adjustment would be to control the speed of rollers within the chamber 120 to alter the position of certain substrates 10 keep consistent gaps between the substrates. It should be appreciated that the monitoring and detection of temperature changes will follow the principles discussed above with respect to FIGS. 2 and 4 . In the illustrated example, the controller 150 could use the inputs of detectors 130 a , 130 b, positioned within a know distance from each other, to determine if any substrate has been rotated or skewed.
The disclosed systems 10 , 110 will experience improved cycle times in the process e.g., a VTD process, because of accurate substrate detection. It should also be appreciated that using infrared detectors reduces the likelihood of false detections and other failures experienced by conventional substrate detection mechanisms using lasers, light reflectors and light detectors. The disclosed systems 10 , 110 are better suited for a deposition or sputtering environment and have many advantages over other detection mechanisms. For example, the systems 10 , 110 disclosed herein will not require clean chamber windows because infrared wavelengths pass through typical deposits used within the chamber. Thus, additional maintenance and down time will not be required. Moreover, the alignment issues experienced by detection mechanisms relying on lasers, light reflectors and light detectors will not exist in the systems 10 , 110 disclosed herein because a reflector is not required. As can be seen, one major advantage of the disclosed systems 10 , 110 is that there is no need to ensure a clean beam path into the chamber because detection is being based on temperature and not reflected light.
Details of one or more embodiments are set forth in the accompanying drawings and description. Other features, objects, and advantages will be apparent from the description, drawings, and claims. Although a number of embodiments of the invention have been described, it will be understood that various modifications can be made without departing from the scope of the invention. Also, it should also be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features and basic principles of the invention. The invention is not intended to be limited by any portion of the disclosure and is defined only by the appended claims.
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Infrared detection is used to monitor the temperature within a vapor transport deposition processing chamber. Changes in temperature that occur when a substrate passes an infrared detector are detected and used to precisely locate a position of the substrate within the chamber. Position correction of the substrate can also be implemented.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for disarming an automobile alarm system by using the ignition switch of the automobile to create a sequential pulse code generated by shifting the ignition switch to various positions.
2. Description of the Prior Art
To simplify installation, the method of turning an automotive security system ON and OFF has evolved from a simple key switch on the vehicle's fender to more sophisticated means involving electronic devices which turn themselves on automatically after turning off the ignition switch (Passive Arming,) and, more recently, radio frequency remote control transmitters which send coded radio signals to a receiver in the alarm unit installed in the vehicle.
One type of known "Passive" or automatic arming system is controlled only by the ignition key and is disarmed by entering the vehicle and then turning on the ignition switch that supplies power to a wire connected to the system to disarm it. Another type of passive arming alarm system is controlled by a remote control transmitter and is disarmed initially by the transmitter, but is designed to automatically rearm unless the ignition switch is turned on as a final step to disarm the system.
With both types of passive arming systems, a switch called a "valet" or override switch is typically installed and provides yet another means of disarming the system. The purpose of the valet switch is twofold. First, it allows putting the alarm system into a stand-by or "valet" mode when it is desired that the system should not arm itself automatically, such as when leaving the vehicle for servicing, or when leaving the vehicle with a parking valet. Second, it allows the operator to selectively override an armed system (i.e., to disarm it) as may be necessary when the transmitter control either does not work or has been lost.
The valet switch is typically mounted under the dashboard so it is out of sight but where it is easily accessible by a person sitting in the driver's seat. Hiding it in a more secure location would make installation time burdensome, as well as make it much harder to use. Normally, the switch will not perform any function unless the ignition switch keylock actuator (typically located on the steering column) is in the ON switch position. To override and disarm a system without the transmitter, one must enter the vehicle, turn the ignition switch to the ON position, and then move the valet switch to disarm the system.
A main security problem with the conventional passive alarm system is that the valet switch is only as secure as the ignition switch keylock actuator. Thieves know how the valet switch works. They either break out the ignition switch keylock actuator or break apart the side of the steering column, to access the mechanism that controls the electric ignition switch. They turn the electric ignition switch to the ON position, find the easily accessible valet switch and turn it on to disarm the system. A second security problem is that the wires from the valet switch lead directly back to the alarm control module, which is usually concealed under the dashboard, making it easy to find and disconnect the alarm system.
U.S. Pat. No. 5,381,128 to Kaplan discloses an automobile alarm system provided with an override arrangement which does not require a valet switch. The alarm system is disarmed or deactivated without a radio transmitter by turning the ignition switch from its OFF to its START (starting motor cranking) position a selected number of times. The deactivation circuitry takes advantage of the fact that in most vehicle systems, a signal pulse is produced by or available to the system which is only present when the system is armed and an attempt is made to start the vehicle. The circuitry counts these "start attempt" pulses and compares the count to a coded number chosen by the vehicle owner, i.e., the override code. If the counts match, the system will be disarmed. This scheme, however, has obvious drawbacks. The override code could be duplicated with ease by a thief, simply by turning the ignition switch on and off until the system sees the correct number of "start attempt" pulses. If optional time delay circuitry is included for further security--requiring waiting a fixed period in between pulses or after the pulses--it would be difficult for the owner to wait the proper time in such circumstances as in the dark, where one can't see a watch to wait the proper time, or in emergencies, where a person might naturally rush or miscount time.
It would be a great advancement in the field of automotive security systems to be able to provide means having a higher level of security than conventional valet switches and which means would provide an alternative way to set the alarm system into a valet mode, including selectively overriding and disarming the system.
SUMMARY OF THE INVENTION
It is a general object of the invention to provide a method and apparatus for disarming an automobile alarm system that overcome the main security problems of conventional alarm systems.
It is another object of the present invention to provide an improved method and apparatus for disarming an alarm system which eliminates the valet switch and does not require the use of a remote radio transmitter and thwarts the usual theft methods.
These and other features of the invention are attained by using two commonly available electrical circuits in the vehicle's wiring that are switched on and of by the shifting of a vehicle's ignition switch to supply a pulse code of sequential electric pulses to the alarm system to perform a selected function, including entering a valet mode or overriding and disarming the system without a remote control transmitter.
Because the shifting of the ignition switch generates a two-wire detectable pulse code, previously-programmed pulse codes can be selected to perform different functions in addition to disarming the system, including using pulse codes to trigger entry of the system into a learning mode.
The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated.
FIG. 1 is a block diagram of an alarm system constructed in accordance with the present invention;
FIGS. 2 and 3 show ignition switch keylock actuator configurations for an American-type vehicle and for a foreign vehicle, respectively;
FIG. 4 is a flowchart showing the steps for entering a valet mode by the alarm system's recognition of a pulse code entered by shifting of the ignition switch among its various positions;
FIG. 5 is a flowchart of a transmitter learn routine;
FIG. 6 is a flowchart of a pulse code learn routine; and
FIG. 7 is a flowchart of a feature/option learn routine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, and more particularly FIG. 1 thereof, there is depicted a vehicle security system 10, incorporating the features of the invention, intended for installation in a vehicle (not shown) and to draw 12-volt power from the vehicle's battery 11. The system includes an alarm module 15 which, when the system is armed, activates appropriate alert signals when an intrusion into the vehicle passenger space is detected by any of the sensors (not shown) attached to the vehicle. If the alarm system 10 is armed (LED 16 lighted) and an intrusion is detected, based on pre-programmed feature options, one or more of the following may occur to scare away the intruder, or alert a passerby: a siren 17 may sound, the vehicle's lights (parking, dome, etc) may flash, and/or the vehicle horn may sound.
The sensors may be any of a number of infra-red, ultrasonic, microwave, radio-wave or other known type of vehicle sensors, including switch-type sensors, able to detect or sense motion or other conditions and to transmit appropriate low-level electrical output signals to the alarm module 15. In the illustrative embodiment, alarm module 15 is constituted by a programmable array logic (PAL) circuit (not shown). It should be understood that the PAL circuit is designed to execute appropriate security logic routines which, in response to electrical inputs from various electrical circuits on the vehicle, operate to arm and disarm the alarm system in a unique way, and provide a programmable means for setting alarm operating features and conditions. The routines constituting the present invention are described in greater detail below in connection with FIGS. 4-7.
In addition to receiving trigger inputs from any of the available sensors via line 12, the alarm module 15 receives timing signals (OSC) from an onboard oscillating circuit (not shown) via line 13. If the system is to be used in a vehicle with power door locks, alarm module 15 may be coupled via appropriate wiring connections 18, 19 to a power door lock module (not shown) for automatically controlling those door locks. An optional external valet switch 20 may also be provided although, as is explained below, the present invention makes the valet switch unnecessary.
Additionally, the alarm module 15 may be controlled remotely by signals on line 21 from a hand-held RF coded transmitter (not shown) usually carried by the vehicle's operator. The transmitter is designed to emit one or more RF signals (RF input) for automatically arming and disarming the system in a known manner, and for allowing the operator to select or change one or more alarm operating features and/or conditions, as will be explained below.
Additionally, the alarm control module 15 is coupled to the vehicle ignition switch (not shown) which is operated by a key-lock actuator 50 or 50A (see FIGS. 2 and 3) among a normally OFF (locked) position and several power-applying positions, including accessory (ACC), ignition (ON) and start (START) positions. When the vehicle operator rotates the ignition key-lock actuator 50 or 50A to a power applying position, he moves an associated electrical mechanism (not shown) of the ignition switch to power appropriate wires to supply power to associated circuits in the vehicle.
Different circuits are turned on and off when the key-lock actuator 50 or 50A is moved to different positions. For example, when the actuator 50 or 50A is in the ACCESSORY (ACCY) position, a wire 22 (the "accessory circuit wire") is supplied with (+) 12V DC power through the ignition switch. When the actuator 50 or 50A is in the ON position, both the accessory circuit wire 22 and a wire 23 (the "main ignition-ON circuit wire") are supplied with (+) 12V DC power. The alarm module 15 is connected to the accessory circuit wire 22 and the ignition ON circuit wire 23, whereby by sensing the movement of the ignition switch among the various positions and by recognizing the sequence in which the ignition switch is moved back and forth as equivalent to that of a preprogrammed access code sequence, an appropriate pre-programmed action is automatically performed by the alarm system 10.
Before describing in detail the manner in which the ignition switch movement permits alarm function selection in accordance with the present invention, it should first be pointed out that there are generally two different types of ignition switches. In the typical American-made vehicle, the key-lock actuator 50, as shown in FIG. 2, starts in Lock (Off) position and turns clockwise to the "ON" position, where the ignition-ON circuit wire 23 and the accessory circuit wire 22 are both supplied with +12V DC power. Continuing forward to the START position turns off power to the accessory circuit wire 22 and turns on power to a vehicle starter circuit wire. The ignition-ON circuit wire 23 remains powered during movement of the actuator 50 between the ON and START positions. Rotating the actuator 50 backwards or counterclockwise from the LOCK (OFF) position sets the ignition switch in the ACCY position. In this position, +12V DC power is supplied only to the accessory circuit wire 22. By rotating the actuator 50 backwards and forwards, power-applying pulses are produced on the respective accessory circuit and ignition-ON circuit wires 22 and 23. These pulses constitute a sequence code which is recognized by the alarm module 15, on the basis of which a desired preprogrammed function may be performed automatically by the alarm module 15, as will be described below.
The movement pattern of the actuator 50A found in non-American or "Foreign" vehicles, and shown in FIG. 3, is slightly different than that of a actuator 50 found in the typical American-made vehicle. Foreign-vehicle actuators 50A include an initial LOCK (Off) position with the actuator only rotating forward from the LOCK position, first to the ACCY position, then to the ON position, then to the START position. This ignition switch pattern is different in that the accessory circuit wire 22 stays at (+)12V in both the ACCY and ON positions, and does not turn off or lose power between the two positions, as is the case with American-type actuators 50.
Regardless of the type of ignition switch present in the vehicle in which the alarm system 10 is to be installed, the present invention aims to take advantage of the fact that, by tapping into the accessory circuit and ignition-ON circuit wires 22 and 23, a two-wire electrical "pulse code" may be generated as the ignition switch is moved among these power-applying positions by a vehicle operator. In this regard, the alarm module 15 includes logic circuitry which allows for the different characteristics of both American and foreign-type ignition switches, while permitting unambiguous recognition of the ACCY and ON positions. The pulse code generated by the ignition switch may serve as an instruction to the alarm module 15 to perform a valet or override function--i.e., putting the alarm system 10 in a valet mode whereby the alarm system is disarmed,--thus eliminating the need for an external valet switch. The pulse code pattern may also serve as an instruction to perform other functions, such as entering into different programming modes for learning new transmitter codes and selecting feature options within the alarm system 10.
1. Entering Valet Override Mode
In the illustrative embodiment shown in FIG. 1, an external valet (toggle) switch 20 is optionally provided for controlling the valet and override functions in a conventional manner. The method of putting the alarm system 10 into the valet/override mode without using this external valet switch (or eliminating it altogether) is achieved (see FIG. 4) by the alarm module 15 sensing a two-wire sequence of power-applying pulses produced on the ignition-ON (+12V) circuit wire 23 and the accessory (+12V) circuit wire 22 as the actuator 50 or 50A is rotated among its various positions, to provide a pulse code (110) to turn valet mode ON and OFF (120), and to override the system if armed.
The main ignition-ON circuit wire 23 and the accessory circuit wire 22 both provide +12V when the ignition key is turned forward to the ON position. In an exemplary embodiment, the user wants the alarm to go into or out of valet mode or into override mode when it sees the following pre-programmed pattern of movements for an American-type actuator 50, starting with the ignition switch in the OFF position: ACCY! OFF! ACCY! OFF! ON! OFF! ACCY!. The logic circuitry of the alarm module 15 will recognize the various switch positions by the following conditions produced at the ignition-ON circuit and accessory circuit wires, wherein logic 1 represents +12v and logic 0 represents 0v:
Switch position OFF= ON 0, ACCY 0!
Switch position ACCY= ON 0, ACCY 1!
Switch position ON= ON 1, ACCY 1!
It will be appreciated that in foreign-type actuators 50A, the same pulse code would be obtained by the following sequence of movements starting in the OFF position: ACCY! OFF! ACCY! ON! ACCY!.
The alarm module 15 recognizes a "pulse" of the pulse code only when it sees an ON or an ACCY switch position. The OFF switch position in the sequence is not seen as a "pulse", since no power is applied to either of the wires 22 and 23. In the example above, the selected code was a four-pulse code starting in the OFF position: ACCY, ACCY, ON, ACCY. The system 10 would enter the valet-mode when it sees the last ACCY position. For security, the system 10 should accept a predetermined number of code "pulse" signals within a predetermined time period, e.g., 10 seconds, with the necessity of at least one ACCY position pulse in any code. For ease of operation, the code should have a minimum of two pulses, but for higher security the recommended minimum number is three pulses. The code could include up to about 12 pulses within the 10-second time period.
2. Entering Learning Mode
As indicated above, the pulse code concept can be extended further to generate a pulse code pattern recognizable by the alarm module 15 to perform other functions, such as entering into a learning mode where, in the preferred embodiment, one of three actions may be taken, including (1) programming the alarm system 10 to accept RF signals from a new RF control transmitter (FIG. 5), (2) programming the system 10 to accept a new pulse code for entering into the valet or override mode (FIG. 6), and (3) programming the system 10 to select different feature options (FIG. 7).
A. To Enter Transmitter Code Learning (200) (FIG. 5):
1. Put system into valet mode (210) using transmitter, external valet switch if available, or enter valet-entering pulse code pattern (FIG. 4)
2. Within 5 seconds after putting into valet mode, starting with the ignition switch in the OFF position, turn ignition switch to the following positions: ACCY, OFF, ACCY, OFF, ACCY, and leave in ACCY position (220).
3. One long Siren Chirp will signal ready to accept RF signal of a multi-channel transmitter (230). The receipt of an RF signal would be confirmed by one long Siren Chirp, and the learn routine would accept the new RF signal as another transmitter to operate this system (240, 250). In the constructional embodiment, there is program capacity for four separate transmitters. Learning a fifth transmitter's RF signal would eliminate the first learned transmitter's RF signal from memory. Entering the first channel of a transmitter is sufficient for the alarm to respond to all the channels of the transmitter.
B. To Enter ON/ACCY Pulse Code Learn Routine (300) (FIG. 6):
1. Put system into valet mode (310) using transmitter, external valet switch if available, or enter valet-entering pulse code pattern (FIG. 4)
2. Open door and leave open (320).
3. Within 5 seconds after putting into valet mode and/or opening door, turn ignition switch to the following positions: ACCY, OFF, ACCY, OFF, ACCY, and leave in ACCY position (330).
4. One long and one short siren chirp will indicate ready to accept new pulse code sequence for the next fifteen seconds, starting and ending with the ignition switch in the OFF position (340).
5. Turn the ignition switch to the OFF position, then enter the chosen new pulse code, ending with the ignition switch in the OFF position (350, 360). The system will recognize the last power-applying pulse during the 15-second period as the last pulse of the code, after which the system will accept the new pulse code and overwrite the old pulse code with the new pulse code. The siren will give 2 sets of one long and one short chirp to indicate the code is accepted (370).
6. Close door to exit routine (380, 390).
If the fifteen seconds elapses while the pulse code is still being entered, the siren will sound two long and then two short pulses, and the operator must start sequence again by closing the door, and then re-performing steps 2-6.
When programming a new pulse code, the system should see that the new pulse code must start with the ignition switch in the OFF position, and should note the last code pulse before the ignition switch goes back to OFF during the 15-second period as the pulse after which the system will enter either the valet or override mode, depending on whether the system is Armed or disarmed.
C. To Enter Feature/Operation Select Routine (400) (FIG. 7):
1. Do NOT put system into Valet.
2. Open door and leave open (410).
3. Within 5 seconds after opening the door, turn ignition switch to ACCY, OFF, ACCY, OFF, ACCY, and leave in ACCY position (420).
4. One long and two short siren chirps will indicate ready to accept new settings for the Feature/Operation ON/Off chart below.
Pressing RF Transmitter Button #1 will select which feature is to be changed (430, 440). Short siren chirps will indicate the feature number selected.
After the feature number is selected, pressing Transmitter Button #2 (450, 460) will select one of two operating conditions of that feature.
One chirp will indicate one condition and two chirps will indicate the other condition, in accordance with the following table of selectable features:
______________________________________Number Feature 1 Chirp = 2 Chirp = Preset______________________________________1 .8 or 3.5 sec. door lock .8 sec. 3.5 sec. .8 sec. pulse2 When in manual arming mode ON OFF ON automatic rearm system if disarmed by transmitter, then no door open within 30 seconds.3 No auto door unlock pulse ON OFF OFF when turning ignition switch off.4 No auto door lock pulse if ON OFF OFF door is open when turn on Ignition.5 2 Door unlock pulses 1 sec. 1 pulse 2 pulses One apart.6 Code hopping RF circuit ON OFF ON______________________________________
To exit the Feature/Option Select Routine, turn the ignition switch to the OFF position. Two sets of one long and two short siren chirps will signal exit of routine. If no RF code is input within 10 seconds after entering this learn routine, or after selecting a feature number by pressing transmitter button #1, the system will automatically end the routine, retaining whatever settings were entered.
By analyzing and developing a means of using different powered electrical circuits from the vehicle's own ignition switch to create an electrical "pulse code" that is programmed into a security system to be accepted to perform various functions, we have eliminated the need for valet and/or override/disarm switches that are uniformly installed with an automotive security system. This accomplishes the following goals to achieve a higher level of security than that provided by present security systems:
1. thwarts several of the usual methods used to defeat security system;
2. eliminates the telltale wiring from the valet or override switch that leads to the security system alarm module 15, which makes locating that module much more difficult for the thief; and
3. provides for simple, faster more secure installation of the security system.
By tapping into the ignition-ON and accessory wires as inputs to provide a programmable coded signal to the alarm system 10, the act of overriding/disarming the alarm or entering valet mode can be performed without installing a valet switch, thus eliminating the usual means of defeating the system and the telltale wires that lead from the valet switch back to the control module.
It should be appreciated that by programming the alarm system 10 to learn and accept one of many various combinations of (+)12 volt pulses from the ignition switch "ACCY" and "ON" positions within a given time limit to enter the override or valet mode, a higher level of security can be achieved.
Furthermore, it should be appreciated that since the present invention is based on the idea of using a two-wire (ON-ACCY) generated pulse code to select/reprogram alarm functions, a much higher level of security is provided than would be the case with a one-wire pulse code technique. Of course, more than two wires can also be used to further improve security. This may involve coupling the alarm module 15 to yet another trigger-pulse generating circuit. For example, in addition to moving the ignition switch to put the vehicle in valet mode, the operator may also be required to strike the power-door lock button, or hit the power-seat button, or turn-on the parking lights, or the brake lights or the dome light. The extra step(s) can be done during the shifting of the ignition switch or any time before or after. With two or more wires (pulse generating inputs) being used, the complexity of the pattern of the security code is greatly increased, thereby making it much more difficult to duplicate deliberately or accidentally.
It is also notable that the system does not use a pattern of long and short pulses on one wire, because of the difficulty of successfully duplicating the timing of such a pattern by the user, and the low number of combinations that kind of coding would provide.
While particular embodiments of the present invention have been shown, and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
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An apparatus and method for disarming an automobile alarm system uses the ignition switch of the automobile to create a sequential pulse access code. Toward this end, two commonly available electrical circuits in the vehicle's wiring that are switched on and of by the shifting of a vehicle's ignition switch among power-applying switch positions serve to supply a pulse code of sequential electric pulses to the alarm system to perform a selected function, including entering a valet mode or overriding and disarming the system without a remote control transmitter. Because the shifting of the ignition switch generates a two-wire detectable pulse code, previously-programmed pulse codes can be selected to perform different functions in addition to disarming the system, including using pulse codes to trigger entry of the system into a learning mode.
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FIELD OF THE INVENTION
The present invention relates to the field of electrochemical deposition, and in particular to a method of forming a metal seed layer by electroplating.
BACKGROUND OF THE INVENTION
The performance characteristics and reliability of integrated circuits have become increasingly dependent on the structure and attributes of the vias and interconnects which are used to carry electronic signals between semiconductor devices on integrated circuits or chips. Advances in the fabrication of integrated circuits have resulted in increases in the density and number of semiconductor devices contained on a typical chip. Interconnect structure and formation technology has lagged behind these advances, however, and is now a major limitation on the signal speed of integrated circuits.
Current techniques for forming vias and interconnects begin with preparation of the semiconductor wafer surface by formation of an interlevel dielectric layer (ILD), typically silicon dioxide. A mask may then be applied to pattern the deposition of the interconnect material on the wafer in the desired manner. Another typical process is to plate the interconnect material onto the surface of the wafer to a depth sufficient to fill the vias, followed by planarization to achieve the desired interconnect pattern.
Typically the preferred metal for use in the construction of integrated circuit interconnects has been aluminum. Aluminum is widely used because it is inexpensive, relatively easy to etch, and adheres well to ILDs such as silicon dioxide. Disadvantages of aluminum include significant electromigration effects, susceptibility to humidity-induced corrosion, and the tendency to “cold creep”. “Cold creep” is a process that creates cracks or spaces between the interconnect layer and the ILD due to large variances in the coefficient of thermal expansion between the two materials.
The disadvantages of aluminum interconnects have become more pronounced as the geometry of integrated circuits continues to shrink. Chip designers have attempted to utilize different materials to construct an interconnect system having the chemical and mechanical properties which will complement and enhance smaller and faster circuit systems. The ideal interconnect material is inexpensive, and has low resistivity, minimal electromigration effects, high corrosion resistance, and a similar coefficient of thermal expansion to the ILD and substrate material. Metals possessing these properties include gold, silver, and copper, and research has generally focused on these three metals as new via and interconnect materials.
Copper is the most attractive material for use in integrated circuits because of its desirable chemical and mechanical properties. It is an excellent conductor with a resistivity of 1.73 microOhms per centimeter, is inexpensive, and is easily processed. Copper also has fewer electromigration effects than aluminum and can therefore carry a higher maximum current density, permitting a faster rate of electron transfer. The high melting point and ductility of copper produce far less cold creep during the semiconductor fabrication process than many other metals, including aluminum.
Although copper has many favorable characteristics, it also has disadvantages that may create fabrication problems for chip designers. Copper is soluble in silicon and most common ILDs, and exhibits a high rate of diffusion at temperatures associated with integrated circuit manufacturing. This diffusion can result in the creation of intermetallic alloys which can cause malfunctioning of the active semiconductor devices. In addition, copper exhibits poor adhesion to silicon dioxide which can result in broken connections and failure of electrical contacts.
Use of an intermediate barrier layer between the ILD and the copper interconnect permits the successful use of copper in a silicon-based integrated circuit. The barrier layer serves to eliminate the diffusion that would otherwise occur at the copper-ILD junction, and thus prevents the copper from altering the electrical characteristics of the silicon-based semiconductor devices. Such barrier layers are well known in the art and may be formed of a variety of transition metals, transition metal alloys or silicides, metal nitrides, and ternary amorphous alloys. The most common barrier layer materials in use are titanium, tantalum, and tungsten alloys due to their demonstrated ability to effectively reduce copper diffusion.
Deposition of a metallization layer generally occurs through one of the following techniques: chemical vapor deposition (CVD); physical vapor deposition (PVD), also known as sputtering; or electrochemical deposition. CVD involves high temperatures which can lead to cold creep effects and an increased chance of impurity contamination over other methods, and sputtering has problems yielding sufficient step coverage and density at small line widths. Electrochemical deposition, however, offers a more controlled environment to reduce the chance of contamination, and a process that takes place with minor temperature fluctuations. Electrochemical deposition provides more thorough coverage, fewer physical flaws, and reduces separation between the layers.
There are several known electrochemical deposition processes used to form copper interconnects onto barrier layers, each having various disadvantages. Direct deposition of copper onto the barrier layer typically results in porous films with poor adhesion and inconsistent densities. Annealing of the deposited copper at low temperatures may be performed to improve adhesion, but it increases cold creep effects and fails to provide a consistently dense copper structure. A copper seed layer may be formed over the barrier layer by CVD or PVD to produce an adhesive surface, and then electrochemical deposition may be carried out on the seed layer. This method involves multiple steps and increases production costs by requiring several different types of machines to form each interconnect layer.
What is needed, therefore, is a simple and inexpensive method of forming a metal seed layer that requires only a minimum number of steps for its production.
SUMMARY OF THE INVENTION
The present invention provides a method of forming a metal seed layer, preferably a copper layer, for subsequent electrochemical deposition. The metal seed layer is formed by the oxidation-reduction reaction of a metal salt or complex such as copper sulfate in acid solution, with a reducing agent such as elemental silicon that is present in a layer on the substrate to be plated.
Preferably the reducing agent is present in a sacrificial layer on the substrate. The method is particularly suited to forming metal interconnects for semiconductor devices, because the metal seed layer and the plating of the interconnect itself may be combined into a single-bath operation.
Additional advantages and features of the present invention will be apparent from the following detailed description and drawings which illustrate preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a semiconductor wafer undergoing the process of a preferred embodiment of the present invention.
FIG. 2 shows the wafer of FIG. 1 at a processing step subsequent to that shown in FIG. 1 .
FIG. 3 shows the wafer of FIG. 1 at a processing step subsequent to that shown in FIG. 2 .
FIG. 4 shows the wafer of FIG. 1 at a processing step subsequent to that shown in FIG. 3 .
FIG. 5 shows the wafer of FIG. 1 at a processing step subsequent to that shown in FIG. 4 .
FIG. 6 shows the wafer of FIG. 1 at a processing step subsequent to that shown in FIG. 5 .
FIG. 7 is a cross-sectional view of a semiconductor wafer undergoing the process of a second preferred embodiment of the present invention.
FIG. 8 shows the wafer of FIG. 7 at a processing step subsequent to that shown in FIG. 7 .
FIG. 9 shows the wafer of FIG. 7 at a processing step subsequent to that shown in FIG. 8 .
FIG. 10 shows the wafer of FIG. 7 at a processing step subsequent to that shown in FIG. 9 .
FIG. 11 shows the wafer of FIG. 7 at a processing step subsequent to that shown in FIG. 10 .
FIG. 12 shows the wafer of FIG. 7 at a processing step subsequent to that shown in FIG. 11 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized, and that structural, logical, electrical and chemical changes may be made without departing from the spirit and scope of the present invention.
The terms “wafer” and “substrate” are to be understood as including silicon-on-insulator (SOI) or silicon-on-sapphire (SOS) technology, doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor structures. Furthermore, when reference is made to a “wafer” or “substrate” in the following description, previous process steps may have been utilized to form regions or junctions in the base semiconductor structure or foundation. When referring to aqueous solutions described herein, the term “percent” refers to the percent measured by weight, e.g., a 10% hydrofluoric acid solution is 10% by weight hydrofluoric acid.
The following description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
Referring now to the drawings, where like elements are designated by like reference numerals, an embodiment of the present invention for manufacturing an integrated circuit having a metal interconnect is illustrated by FIGS. 1 through 6. The process creates a metal seed layer for subsequent electrochemical deposition by a oxidation-reduction (“redox”) reaction between a reducing agent present in a sacrificial layer of material, and a metal salt or complex. For illustrative purposes the invention is described as a method of plating copper by a reaction in which the reducing agent is silicon, but the use of other metals and reaction mechanisms is to be understood as within the scope of the invention.
The process begins subsequent to the formation of a semiconductor device 20 containing devices 24 , which may be transistors, capacitors, word lines, bit lines or the like, and active areas 26 on a silicon substrate 22 , as shown in FIG. 1. A protective layer 28 of a material such as borophosphosilicate glass (BPSG), phosphosilicate glass (PSG), borosilicate glass (BSG), or silicon dioxide has been formed over the device 20 by chemical vapor deposition (CVD) or other suitable means.
The process of the present invention begins by applying a photoresist and mask (not shown), and by using photolithographic techniques to define areas to be etched out. Referring to FIG. 2, a directional etching process such as reactive ion etching (RIE) is used to etch through the protective layer 28 to form vias 30 . T he etchant used may be any suitable etchant that selectively etches t he material of the protective layer 28 and not the active areas 26 , the devices 24 , or the material of sidewall or cap insulators on the devices 24 .
FIG. 3 depicts the next step of the process, in which a barrier layer 32 is formed so that it overlies the protective layer 28 and lines the inside of the vias 30 . Barrier layers are typically used with metal interconnect material to optimize performance of the interconnect s, and to prevent diffusion of the metal interconnect material into the substrate. The barrier layer 32 may be formed of any suitable material such as titanium, titanium nitride, tantalum, tantalum nitride, tungsten nitride, tungsten-tantalum, tantalum silicon nitride, or other ternary compounds, and should be of a thickness within the range of 50 to 500 Angstroms, and preferably approximately 300 Angstroms thick. Chemical vapor deposition, physical vapor deposition (PVD), or other suitable means may be used to form the barrier layer 32 .
Next, a sacrificial oxide layer 34 is formed over the barrier layer 32 and lining the inside of the vias 30 , as shown in FIG. 4 . The sacrificial oxide layer 34 is a layer of silicon-containing material such as silicon dioxide or silicon monoxide that is formed by means such as CVD, PVD, oxidation of the wafer in an ozone-containing rinse bath, or the like. Preferably the oxide is a chemical oxide. The sacrificial oxide layer 34 has a thickness within the range of 10 to 200 Angstroms, preferably 10 to 50 Angstroms, and should have a silicon-tooxygen ratio of greater than 0 . 5 . Depending on the reaction mechanism, a sacrificial oxide layer 34 may not be required, and a reactive barrier layer 32 may be used if there is a sufficient amount of the reducing agent present in the barrier layer 32 .
FIG. 5 depicts the next step of the process, in which a metal seed layer 36 is now formed on the surface of the barrier layer 32 in the vias 30 by a redox plating process. The plating process is carried out by exposing the wafer 20 to a first plating solution by means such as immersion of the wafer 20 into a plating bath, or by spraying the plating solution onto the wafer 20 . The first plating solution is an aqueous solution of an acid such as hydrofluoric acid or sulfuric acid, and a metal salt or complex that is soluble in the acid used. A redox reaction occurs between the metal ions in the solution, e.g., cupric ions (Cu 2+ ) and the reducing agent of the sacrificial oxide layer 34 , e.g., silicon, leading to reduction of the metal ions and subsequent plating onto the barrier layer 32 .
For example, in a copper plating process, a dilute solution of hydrofluoric acid (HF) and a salt such as copper sulfate (CuSO 4 ) is used to carry out the reaction with a sacrificial oxide layer 34 containing silicon as a reducing agent. Preferably a solution containing approximately 1 part hydrofluoric acid per 100 parts water, and about 3 grams of copper sulfate per liter is used, and the reaction is allowed to proceed at room temperature for approximately 2 to 2.5 minutes for a sacrificial oxide layer 34 that is approximately 50 Angstroms thick. The time and temperature may be adjusted as necessary for the thickness of the sacrificial oxide layer 34 , and to affect the rate of the reaction. The precise reaction that occurs in the copper plating process is unknown, but is currently believed to be:
Si+2Cu 2+ +6F→SiF 6 2− +2Cu
The plating bath in a preferred embodiment is electroless, but an electrolytic bath may also be used. An electrolytic bath permits formation of a thicker metal seed layer 36 than an electroless bath, because electrons are continuously replaced by the electric current applied and therefore the metal ions, which have an electron affinity, may continuously plate to the barrier layer 32 . If desired, the plating process may begin as an electroless process, and a voltage may later be applied to carry out an electrolytic plating process.
A conductive layer 38 is now formed in the vias 30 to serve as an interconnect layer, as shown in FIG. 6 . The conductive layer 38 is a layer of metal, which may be the same metal as the metal seed layer 36 , or a different metal. Preferably the metal seed layer 36 and the conductive layer 38 are layers of the same metal. The conductive layer 38 is formed by an electrochemical deposition process such as electrolytic or electroless plating.
Preferably the conductive layer is formed by exposing the wafer 20 to a second plating solution by means such as immersion of the wafer 20 into a plating bath, or by spraying the second plating solution onto the wafer 20 . The second plating solution is typically an aqueous solution of an acid such as sulfuric acid, a metal salt or complex that is soluble in the acid used, and several additives. Either electroless or electrolytic plating, or a combination of the two may be performed as desired for certain applications. In addition, any number of semiconductor wafers may be simultaneously processed by using a large bath, thereby reducing the cost of manufacture.
If the metal seed layer 36 and the conductive layer 38 are formed from the same metal, then the plating process may be carried out in the same plating bath that was used for formation of the metal seed layer 36 , and may use the same plating solution. If the metal seed layer 36 and the conductive layer 38 are formed from different metals, then the same tank may be used for both plating processes if the first and second plating solutions are cycled through the tank. Subsequent to the plating process, conventional processing methods, such as planarization of the wafer 20 to isolate the conductive layer 38 into individual contact plugs, may then be used to create a functional circuit from the semiconductor wafer 20 .
A second embodiment of the present invention is illustrated by FIGS. 7 through 12. Referring to FIG. 7, a semiconductor device 120 contains devices 24 , active areas 26 , and field oxide regions 40 on a silicon substrate 22 . A protective layer 28 has been formed over the device 120 , and conductive plugs 42 extend through the protective layer 28 to contact the active areas 26 . A protective layer 44 of a material such as BPSG, PSG, BSG, or silicon dioxide has been formed over the device 120 by CVD or other suitable means.
Photolithographic techniques and subsequent etching are then used to define and form a damascene opening or trench 30 , as shown in FIG. 8 . Referring now to FIG. 9, a barrier layer 32 is now formed so that it overlies the protective layer 44 and lines the inside of the trench 30 , as explained with reference to FIG. 3 above. Next, a sacrificial oxide layer 34 is formed over the barrier layer 32 and lining the inside of the trench 30 , as shown in FIG. 10, and as further described with reference to FIG. 4 above.
FIG. 11 depicts the next step of the process, in which a metal seed layer 36 is now formed on the surface of the barrier layer 32 in the trench 30 by a redox plating process, as is described further above in reference to FIG. 5 . Lastly, a conductive layer 38 is formed in the trench 30 to serve as an interconnect layer, as shown in FIG. 12 . The conductive layer 38 is a layer of metal formed by an electrochemical process, as is described more fully with reference to FIG. 6 above. Subsequent to the plating process, conventional processing methods, such as planarization of the wafer 120 , may then be used to create a functional circuit from the semiconductor wafer 120 .
As can be seen by the embodiments described herein, the present invention encompasses methods of forming a metal seed layer via a redox reaction with a reducing agent. The reducing agent may be present in a sacrificial layer on the substrate to be plated, or may be in a non-sacrificial layer.
It should again be noted that although the invention has been described with specific reference to semiconductor wafers, the invention has broader applicability, and may be used in any plating application in which a thin self-limiting seed layer is used.
The above description and drawings are only illustrative of preferred embodiments which achieve the objects, features and advantages of the present invention. It is not intended that the present invention be limited to the illustrated embodiments. Any modification of the present invention which comes within the spirit and scope of the following claims should be considered part of the present invention.
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A method of forming a metal seed layer, preferably a copper layer, for subsequent electrochemical deposition. The metal seed layer is formed by the oxidation-reduction reaction of a metal salt with a reducing agent present in a layer on the substrate to be plated. Metal interconnects for semiconductor devices may be produced by the method, which has the advantage of forming the metal seed layer by a simple electrochemical plating process that may be combined with the plating of the interconnect itself as a single-bath operation.
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This is a continuation of co-pending application Ser. No. 310,827 filed on Feb. 14, 1989, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to centrifugal blowers and fans.
Centrifugal blowers and fans generally include an impeller that rotates in a predetermined direction in a housing, and may be driven by an electric motor. The impeller has curved blades which draw air in axially, along the impeller's axis of rotation, and discharge air radially outwardly. Such blowers are used in a variety of applications, which dictate a variety of design points for pressure difference, airflow volume, motor power, motor speed, space constraints, inlet and outlet configuration, noise, and manufacturing tolerances.
One important design feature in a centrifugal fan is the angle of the blade tip relative to a tangent to the tip. This angle is called the "blade exit angle". If the blade exit angle is greater than 90°, the impeller is said to have forwardly curved blades; if the blade exit angle is less than 90°, the impeller is said to have rearwardly curved blades.
Specific centrifugal blowers described in prior patents are discussed below.
Koger et al., U.S. Pat. No. 4,526,506 and DE No. 2,210,271 disclose rearwardly curved centrifugal blowers with a volute.
GB No. 2,080,879 discloses a rearwardly curved centrifugal blower with stator vanes to convert radial flow to axial flow.
Zochfeld, U.S. Pat. No. 3,597,117 and GB No. 2,063,365 disclose forwardly curved centrifugal blowers with a volute.
Calabro, U.S. Pat. No. 3,967,874 discloses a blower 16 positioned in a plenum chamber 14. The blade configuration and blower design are not apparent, but opening 46 in the bottom of the plenum chamber is in communication with the blower outlet.
GB No. 2,166,494 discloses a centrifugal impeller in a rotationally symmetrical cone-shaped housing, with guide vanes to produce an axial discharge.
GB No. 1,483,455 and GB No. 1,473,919 disclose centrifugal blowers with a volute.
GB No. 1,426,503 discloses a centrifugal blower with dual openings.
Shikatani et al., U.S. Pat. No. 4,269,571 disclose a centripetal blower, which draws air in axial entrance 26 and out of the top periphery of disc 22 and axial exit 27 (3:26-36).
Canadian No. 1,157,902 discloses a rearwardly curved centrifugal blower with a curved sheet-metal guide.
SUMMARY OF THE INVENTION
The invention features a rearwardly curved centrifugal blower having an annular envelope around the impeller, so that the rotating impeller draws air in through a central inlet and forces it radially outward into the envelope and out of an annular discharge. Multiple airfoil vanes are positioned in the annular envelope, in two axially displaced stages. The vanes are angled to turn and diffuse airflow entering the envelope.
In preferred embodiments, the blower comprises means for attaching a flow resistance element (e.g. a heat exchanger) at the annular discharge. The annular envelope is thin (e.g. its inner diameter is at least 80% of its outer diameter). The blower has a blade design and rotational velocity design range which generates flow entering the annular envelope at an angle between 60° and 70° with respect to the blower (impeller) axis. The airfoil vanes turn the flow in the envelope to produce a flow at the discharge at an angle between 0° and 10° with respect to the blower axis. At the rotational velocity design point, flow enters the annular envelope at a rate between 50 and 100 feet/sec.; the vanes are sized and positioned to diffuse flow in the envelope to produce a discharge flow rate of between 10 and 40 feet/sec.
The airfoil vanes of the invention significantly enhance efficiency by converting tangential velocity into static pressure. In fact, in preferred embodiments, the tangential velocity energy is essentially fully extracted in the form of pressure, so that the aiflow leaving the discharge has essentially no residual tangential velocity. The resulting design is also relatively quiet. The heat exchanger (e.g. an automobile air conditioning evaporator) downstream of the discharge provides significant flow resistance; airflow through the heat exchanger is substantially more efficient as a result of the uniform axial flow at the discharge. The invention also enables a relatively compact package.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description of the preferred embodiment is provided to illustrate the invention and not to limit it. The description includes features described and claimed in my commonly owned U.S. patent application filed this day entitled, Centrifugal Fan With Variably Cambered Blades, which is hereby incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-section of a centrifugal blower and automobile air conditioner evaporator.
FIG. 2A is a cross-sectional representation of the impeller blades of the blower of FIG. 1.
FIG. 2B is an enlarged detail of a portion of FIG. 2A.
FIG. 3 is a top view, partially broken away, of the annular envelope of the blower of FIG. 1.
FIG. 4 is a graph of pressure as a function of tangential swirl velocity.
FIG. 5 is a plot of local surface pressure as a function of blade chord position.
STRUCTURE OF THE BLOWER GENERALLY
In FIG. 1, blower 10 includes an impeller 12 consisting of a plurality of blades (14 and 15, shown in FIG. 2) which are described in greater detail below. Impeller 12 is driven by an electric motor 16 attached to impeller axle 18.
Impeller 12 rotates within stator 20, which is a part of generally cylindrical housing 21 extending co-axially with impeller 12 and motor 16. Generally cylindrical motor housing 22 forms the inner diameter of annular envelope 24. The outer diameter of annular envelope 24 is established by housing 21.
AIRFOIL VANES
Positioned within annular envelope 24 are two sets 25 and 27 of airfoil vanes shown best in FIG. 3. C L is the centerline (axis) of the motor, blower and impeller. The vanes extract tangential (rotational or swirl) velocity from air leaving the impeller, and they recapture that energy as static pressure.
Evaporator 30 is attached to the outlet 28 of envelope 24. Swirl in the airflow reaching evaporator 30 is substantially eliminated and air pressure across the evaporator is increased. Specifically, the vanes 25 and 27 are important in part because about 1/4 to 1/2 of the flow energy produced by a rearwardly curved centrifugal blower s in the form of velocity; the airfoil vanes recapture a substantial (40-80%) percentage of this flow energy.
Efficiency of the blower in the form of uniformity of discharge velocity and flow energy recapture is aided by the design of the annular envelope, which is radially symmetrical and smoothly curved. Moreover, the radial extent of the envelope is small, so that the pressure and velocity are relatively uniform across the exit.
The pressure/swirl regime in which the blower operates is demonstrated by FIG. 4 which diagrams pressure coefficient (Cp) as a function of tangential swirl velocity (V t ). In FIG. 4, Cp is defined by the following equation:
Cp=1/2ρV.sup.2 ÷1/2ρV.sub.tip.sup.2
In this equation, V is airflow velocity leaving the impeller, and V tip is the impeller tip velocity. Vt* is the tangential velocity of air leaving the impeller÷V t . The theoretical relationship with (x) and without (o) swirl recovery is shown. Blowers of the invention preferably operate within the cross-hatched area where V t =0.5-1 and Cp=0.5-2.
Those skilled in the art will understand that the exact angle of airfoil vanes 25 and 27 will depend upon the blade configuration (discussed below) and the rotational velocity of the impeller (i.e., the range of rotational velocity within which the blower is designed to operate). It is desirable to match the leading edge of the airfoil to the direction of airflow encountering that leading edge, so that the angle of incidence is negligible. In general, air approaches envelope 24 at an angle of 20-30° from tangential in the regime described above.
It is also desirable to maintain a substantially constant cross sectional area of the airflow (along the blower axis). To this end, there is a reduction in hub diameter at the second stage of stators (indicated by 29 in FIG. 1) to match the reduced cross sectional area created by the higher density of stators in the second stage.
Superimposed on FIG. 3 is a vector diagram for flow V 1 entering the stator, in which V t1 is the tangential swirl velocity entering the stator, and V x1 is the axial velocity of the airstream entering the stator. V to is the tangential velocity of the blower wheel (impeller). Angle α 1 is 20°-30° and angle β 1 is 60-70°. Similar diagrams could be drawn for flow leaving stage 1 and entering stage 2, and for flow leaving stage 2. For flow V 2 leaving stage 2, the angle α 2 between V t2 and V x2 would be 80-90° and angle β 2 is between 0° and 10°. The net effect is that V 2 <<V 1 because of the change in flow angle, even though V x1 =V x2 .
The second stage is necessary because the boundary layer loading value for a single stage exceeds the maximum engineering value (0.6) associated with attached flow. In this context, the diffusion factor is defined as (1-V 2 /V 1 )+(V t1 -V t2 )/2ρV 1 , where V 1 and V 2 are respective airflow velocities entering and leaving the stage, V t1 and V t2 are respective tangential velocities entering and leaving the stage, and ρ is blade solidity (i.e., blade chord÷blade spacing).
IMPELLER BLADES
FIGS. 2A and 2B are cross-sectional representations-of the blades 14 and 15 of the invention, showing their "S" shape (i.e. their reverse camber). The blades are backwardly curved, and (given their relatively small size) develop large thrust or pressure, with good efficiency and low noise. Specifically, FIGS. 2A and 2B shows the "S" shape of long chord blades 14 and shorter chord auxiliary blades 15.
One significant problem in the design of a high thrust backward curved blower is to maintain attached flow on the suction side of the blades all the way from the leading edge to the trailing edge (that is, the blower outside diameter). Boundary layer separation leads to a deviation between the geometric camber lines of the blower blades and the actual flow streamlines. This deviation translates directly into reduced performance since the diffusion process (changing velocity energy into pressure) stops at the point that boundary layer separation occurs. The deviation between the blades and streamlines also leads directly to lower performance by reducing the tangential velocity of the discharge flow.
Maintaining attached flow requires preserving the blade suction surface boundary layer energy as it dissipates along the blade chord. The suction side boundary layer must overcome three significant retarding forces: acceleration associated with the inertial reference frame curvature of the blade surface, a pressure gradient caused by the pressure rise that occurs from the blade leading edge to its trailing edge, and friction that exists at the blade-air interface. It is as though the air were rolling up hill; the air in the boundary layer begins its journey with a certain kinetic energy budget, which is partially dissipated by friction and partially converted into potential energy. At the same time the air follows a curved path, and the momentum change associated with this curvature thickens the boundary layer.
Energy is infused into the boundary layer by the main flow, but less effectively as the thickness of the layer increases. Eventually the retarding forces become greater than the lift forces and the flow separates, that is, diverges from the blade surface. At this point the loss effects described above go into effect.
The blower design of the invention has a combination of high positive camber near the leading edge and apparent negative camber between midchord and the training edge. Thus the blade pulls hard on the flow when the boundary layer attachment is energetic, and pulls gently when the boundary layer attachment is weak. Pulling hard on the flow early produces room for more primary blades; reducing the boundary layer forces proportionately since the net work done by the blower is distributed over all of the blades surface.
In addition, space is produced for intermediate blades with shorter chords, reducing negative lift related BL forces again. The camber lines of these short blades mimic the primary blades in the region where the short blades exist. They could have (but need not have) the "S" shape of the primary blades.
Specifically, the blade configuration of a centrifugal blower is selected using, among other things, knowledge of the following characteristics of blowers:
1. The pressure capacity of a blower increases as the square of the blade tip's tangential velocity at its outside diameter. This velocity is the product of diameter times rotation velocity. Thus, the pressure required by the application largely determines blower speed and diameter.
2. The pressure generated in the blading increases, in theory, to a maximum when the blade exit angle is 90 degrees, as shown in FIG. 4. However, the pressure observed experimentally reaches a maximum when the blade exit angle is still backward curved, at an angle of perhaps 50-60 degrees. Essentially, the 2-dimensional geometry of the blades defines a diffusion passage which has its largest total diffusion when the blade exit angle is 90 degrees. Boundary layer physics prevents realizing this maximum diffusion.
3. The velocity of the air discharged by the blower increases as the blade exit angle increases, and reaches a maximum at a blade exit angle well beyond 90 degrees. The energy invested increases as the square of velocity. In applications where static pressure is required, it can be extracted from a high velocity discharge flow by diffusion. The efficiency of the diffusion process is generally far higher in the blading of the blower than in any process which diffuses the discharge flow--as high as 90 percent for the blading process, versus about 50 percent for the discharge process. It follows that the most efficient blower generally is the one which accomplishes the most diffusion in the blading. However, the blower blade design described herein accomplishes the combination of high efficiency along with small diameter and lower rotational velocity (leading to lower noise).
4. For low noise and best blade diffusion it is necessary to align the blade leading edge with the flow. Thus, the blade entry angle is defined by the RPM, the inlet diameter and leading edge blade span, and the flow design point (ft 3 /min.).
FIG. 5 is a plot of local surface pressure (Cp) versus the blade chord position (designated as a percentage of total chord from 0 at the leading edge to 1 at the trailing edge), where Cp is defined by the following equation, in which P s is the surface pressure and V tip is the tip velocity:
Cp=P.sub.s ÷1/2p(V.sub.tip).sup.2
The plot of FIG. 5 is base a computer model of performance of the primary blades alone. The lower plot represents local surface pressure on the suction surface, and the upper plot represents local surface pressure on the pressure surface. The overall work done is represented by the difference between the average pressure entering the blade (left axis, one-half way between the two plots) and the average pressure leaving the blade (right axis, convergence of the two plots) The plot in FIG. 5 represents a flow of 240 cubic feet per minute, a static pressure of 2.29 and a static efficiency of 0.46.
The "S" shaped blade of the invention pulls hard, as indicated in FIG. 5 by the ΔCp from the high pressure side of the blade to the suction side of the blade, in the chord region 0.0-0.4. For the chord region 0.4-1.0, the blade does less work.
More specifically, the blades have a high positive camber near the leading edge and a negative camber at some point between the mid-point and the tail of the blade. Most preferably the positive camber reaches a maximum of 1-3% in the leading half (e.g. 20-30%) of the blade, and the negative camber is 0.25%-3% in the trailing half (e.g. 70-80%) of the blade.
The operating regime of the blower is further defined by the flow number (J) and the pressure number (K t ) as follows: ##EQU1## In the above equations, n=rotational velocity in revolutions/second, and D=diameter of the impeller in feet. Static pressure is measured in inches of water and is corrected to atmospheric pressure (29.92 inches Hg).
Preferably, the flow number J is between 0.35 and 0.8 and the pressure number K t >2.4. The blade chord Reynolds number is 40,000 to 200,000. Blowers with these characteristics are less than 2 feet in diameter and preferably less than 12 inches.
It is also significant that the cross-sectional area of the outlet 28 of envelope 24 is larger (at least 1.2×) than the area of inlet area 13. The increased area represents blade diffusion, since outlet 28 is filled with airflow. The decreased inlet area significantly reduces noise.
The blower is manufactured by injection molding plastic, using e.g. fiber-filled plastic.
Other embodiments are within the following claims.
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A rearwardly curved centrifugal blower having an annular envelope around the impeller, so that the rotating impeller draws air in through a central inlet and forces it radially outward into the envelope and out of an annular discharge. Multiple airfoil vanes are positioned in the annular envelope, in two axially displaced stages. The vanes are angled to turn and diffuse airflow entering the envelope.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method of building a structure and also to a method to strengthening, or reducing the deflection of, a built structure.
[0002] The invention has been primarily developed for use in relation to portal frame structures that use materials other than steel, such as: aluminium and other alloys; carbon fibre; plastics; ceramics; timber; or glass and will be described hereinafter with reference to these applications. However, the invention is not limited to this field of use and is also applicable for other non-steel structural and architectural works.
BACKGROUND OF THE INVENTION
[0003] When designing a structure or building, consideration must be given to, amongst others requirements, the requirements of strength, deflection and dynamics. It is common for additional material to be required in a structure to satisfy deflection requirements, when compared to the material required to satisfy strength requirements. The additional material increases material and construction costs and can also adversely affect the building's dynamic response (particularly to earthquakes) and also requires a corresponding increase in the building's foundations.
[0004] It is important that the amount of materials used in building structures is minimised from a cost and environmental standpoint. It is an object of the present invention to reduce the material required in a building whilst still satisfying deflection criteria.
SUMMARY OF THE INVENTION
[0005] Accordingly, in a first aspect, the present invention provides a method of building a structure, the method including the steps of:
1. fabricating a generally longitudinal, non-steel sub-structure of the structure with a cable retainer attached to, or forming part of, the sub-structure and that extends substantially longitudinally therealong; 2. assembling the sub-structure into a structure; 3. inserting a cable into the cable retainer; 4. after step 2, applying a tensile force to the cable, relative to the cable retainer; and 5. after step 4, bonding the cable to the cable retainer.
[0011] In a second aspect, the present invention provides a method of building a structure, the method including the steps of:
1. fabricating a generally longitudinal, non-steel sub-structure of the structure with a cable retainer attached to, or forming part of, the sub-structure and that extends substantially longitudinally therealong; 2. inserting cable into the cable retainer; 3. after step 2, applying a tensile force to the cable, relative to the cable retainer; and 4. after step 3, bonding the cable to the cable retainer; and 5. assembling the sub-structure into a structure.
[0017] In a third aspect, the present invention provides a method of strengthening, or reducing the deflection of, a built structure, the method including the steps of:
1. attaching a cable retainer to a generally longitudinal, non-steel sub-structure of the structure with the cable retainer extending substantially longitudinally therealong; 2. inserting cable into the cable retainer; 3. applying a tensile force to the cable, relative to the cable retainer; and 4. after step 3, bonding the cable to the cable retainer.
[0022] The cable retainers are adapted to follow the tensile line of resistance the sub-structure is subjected when loaded during use.
[0023] Preferably, the method includes assembling at least two sub-structures into a structure.
[0024] Preferably also, the method includes inserting at least two cables into the cable retainer.
[0025] The cable is preferably bonded to the cable retainer by any one of the following: welding, gluing (including grouting, most preferably with cementitous grout), or by expanding the cable retainer relative to the cable or shrinking the cable relative to the cable retainer (for example by heating the cable retainer and/or by cooling the cable and thereafter allowing them to shrink and/or expand into engagement with one another) prior to inserting the cable into the cable retainer.
[0026] The tensile force is preferably applied to the cable by jacking.
[0027] The structure is preferably a steel portal frame structure, more preferably produced from I or T section beams or from tubular truss assemblies.
[0028] When the sub-structure is in the form of an I or T section beam, the cable retainer are attached to the web of the beam and, most preferably, passes through the flange of the beam. When the sub-structure is a truss assembly, the cable retainer is in the form of one of the tubular members integral with the truss.
[0029] The sub-structure is preferably utilised in the centre span of the structure. However, the sub-structure can also be used in the columns or walls of the structure.
[0030] In one form, the cable retainer extends within the boundaries of its associated sub-structure. In another form, the cable retainer is attached to the sub-structure external the boundaries of sub-structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Preferred embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings, wherein:
[0032] FIGS. 1 to 11 are each schematic cross-sectional drawings of structures utilising an embodiment of the invention;
[0033] FIG. 12 is an exploded view of the sub-structures comprising the structure shown in FIG. 11 ;
[0034] FIG. 13 is a cross-sectional end view of an embodiment of an I beam suitable for use in the structures shown in earlier drawings;
[0035] FIG. 14 is a cross-sectional end view of another embodiment of an I beam suitable for use in the structures shown in earlier drawings;
[0036] FIG. 15 is a cross-sectional end view of a further embodiment of a rectangular beam suitable for use in the structures shown in earlier drawings; and
[0037] FIG. 16 is a cross-sectional end view of an embodiment of a truss assembly suitable for use in the structures shown in earlier drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] FIG. 1 shows a (non-steel) portal frame structure 20 formed from a centre span 22 , two columns 24 and two foundations 26 . Each half of the centre span 22 and each of the columns 24 represent a sub-structure of the steel portal frame structure 20 .
[0039] The centre span 22 has a first cable retainer 28 attached thereto, by welding in the regions 30 and via the struts 32 in the region 34 . Each of the columns 24 also have cable retainers 36 attached thereto by welding.
[0040] Cables, represented by double headed arrows 38 and 40 , are passed through the cable retainers 28 and 36 respectively. The cables 38 , 40 are tensioned relative to the cable retainers 28 , 36 respectively then bonded to the cable retainers 28 , 36 respectively, prior to releasing the tension in the cables. The tensioning, bonding and releasing steps shall be described in more detail below.
[0041] The cable retainers 28 , 36 extend generally along the longitudinal direction of their associated centre span (sub-structure) 22 or column (sub-structure) 24 . More particularly, the cable retainers 28 , 36 are positioned to follow the tensile line of resistance of their associated sub-structure when the structure 20 is subjected to its intended load during use.
[0042] For example, the portal frame structure 20 shown in FIG. 1 is designed to be subject to a downward and horizontal load/use and the cable retainers 28 , 36 are thus oriented as shown to best resist deflection caused by that load.
[0043] The resulting structure is able to better resist deflection under its designed load conditions as the tension applied to the cables relative to their associated sub-structure stores strain energy in the resulting sub-structure. Accordingly, as forces are applied to structure, the counter strain stored in the sub-structure resists the application of that load.
[0044] The resulting structure can, within certain boundaries, accept load with reduced strain and thus has an increased load carrying capacity for a given deflection. A 50-100% reduction in deflection can result compared to a similar sized existing structure.
[0045] The portal frame structures shown in FIGS. 2-12 each have their components and sub-structures identified with like reference numerals to those used in FIG. 1 . However, in each structure, the cable retainers follow a different path compared the columns and centre span so as to suit differing load conditions.
[0046] The structure 50 shown in FIG. 2 is designed to resist upward and horizontal load conditions/usage.
[0047] The structure 60 shown in FIG. 3 is designed to resist downward and horizontal load conditions/usage.
[0048] The structure 70 shown in FIG. 4 is designed to resist upward and horizontal load conditions/usage.
[0049] The structure 80 shown in FIG. 5 is designed to resist upward and horizontal load conditions/usage.
[0050] The structure 90 shown in FIG. 6 is designed to resist downward and horizontal load conditions/usage.
[0051] The structure 100 shown in FIG. 7 is designed to resist upward and horizontal load conditions/usage.
[0052] The structure 110 shown in FIG. 8 is designed to resist downward and horizontal load conditions/usage.
[0053] The structure 120 shown in FIG. 9 is designed to resist upward and horizontal load conditions/usage.
[0054] The structure 130 shown in FIG. 10 is designed to resist downward and horizontal load conditions/usage.
[0055] The structure 140 shown in FIG. 11 is designed to resist upward and horizontal load conditions/usage.
[0056] FIG. 12 shows the various sub-structures that comprise the structure 140 shown in FIG. 11 . As shown, the centre span 22 is formed from three sub-structures 22 a , 22 b and 22 c . The structure 140 is preferably built by assembling all of the sub-structures into the final form shown in FIG. 11 , inserting cables through the cable retainers, jacking the cables into a state of tension, bonding the cables to the cable retainers (for example with cementitous grout) and then releasing the jacking load on the cables.
[0057] As an alternative, one or more of the sub-structures can be assembled and tensioned according to the method described above, and then subsequently attached to the sub-structures. For example, the centre span sub-structure can be assembled on the ground and, after tensioned cables have been bonded thereto, be raised into its final position and connected to the column sub-structures.
[0058] As a further alternative, cable retainers can be added to a pre-existing structure, or a new structure built without them, which are then tensioned and bonded in the manner described above. This finds particular application in improving the strength and/or deflection performance of an existing built structure or structure whose design is complete.
[0059] FIGS. 13 and 14 show examples of cable retainers 28 , 36 , in the form of tubes, being attached to beams 150 and 152 , for example by welding, which are suitable for use in the previously described structures (for example, those structures shown in FIGS. 1 to 6 ).
[0060] FIG. 15 shows an alternative beam 154 in which the cable retainer 28 , 36 is in the form of an opening or hole or channel through the beam which is suitable for use in a previously described structure (for example, the structure shown in FIG. 10 ).
[0061] FIG. 16 shows an example of cable retainers 28 , 36 , in the form of tubes, being part of a truss assembly 156 , which is suitable for use in the previously described structures (for example, those structures shown in FIGS. 7 to 10 ).
[0062] The structures described above can be designed to meet strength and dynamic requirements, whilst reducing the need to increase the material added to the structure to satisfy deflection requirements. The embodiments described previously advantageously enable the span of a structure to be increased whilst using the same amount of materials to thus provide a larger structure for the same material cost. Conversely, a structure with a like span to an existing structure can be produced using a reduced amount of materials.
[0063] The structures described above are also lighter and cheaper than existing comparable structures, particularly when foundation saving are taken into account.
[0064] Although the invention has been described with reference to specific embodiments, it would be appreciated by those skilled in the art that the invention can be embodied in many other forms. For example, the cable retainers can be of any shape and any number of cables can be inserted therein.
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A method of building a structure, the method including the steps of: 1. fabricating a generally longitudinal, non-steel sub-structure of the structure with a cable retainer attached to, or forming a part of, the substructure and that extends substantially longitudinally therealong; 2. assembling the sub-structure into the structure; 3. inserting a cable into the cable retainer; 4. after step 2, applying a tensile force to the cable relative to the cable retainer; and 5. after step 4, bonding the cable to the cable retainer.
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The present invention relates to an improvement in the method for controlling the operation of a thermodynamic, closed cycle system, such as a turbo-machine group including a gas turbine driving a compressor and an electrical generator, wherein the gaseous working medium circulates within the system in a closed cycle, and an apparatus by which the improved method can be performed.
BACKGROUND OF THE INVENTION
When the quantity of the gaseous working medium flowing in a closed-cycle gas turbine system is controlled there takes place solely a proportional change in gas pressures at various locations within the circulation system while the aerodynamic and thermodynamic conditions remain constant for all practical purposes. The mechanical efficiency of the system will therefore retain its designed magnitude over a wide range of power load. This type of gas quantity control represents for this reason the primary method of regulating closed-cycle gas turbine systems. Any improvement and simplification of the various components necessary for performing the gas quantity control is therefor desirous and advantageous.
It is immaterial for gradual changes in power output of a closed-cycle type of gas turbine system whether gaseous working medium is added or removed, respectively at the high-pressure side or the low-pressure side of the gas circulating system. An intermediate pressure storage in cascade connection, as illustrated in FIG. 1, is particularly suitable for changing the output within a maximum and a specifically set minimum value when using a filling gas quantity control mode of operation.
In order to accomplish a reduction in load, gas storage tanks S 1 to S n as in FIG. 1 can be charged in succession by means of valve controls, with the gaseous working medium being removed from the system at the output side of the compressor V.
In order to accomplish an increase in the power output of the turbo-machine group, gaseous working medium can be returned to the system at the low-pressure side, e.g., at the inlet side to the compressor. The tanks S 1 to S n will then discharge the gas, again in succession until the pressure is equalized as desired.
In order to attain a rapid increase in load, the so-called load surges, it is necessary to inject the gas into the system at a point of higher pressure, at the earliest between two serially connected compressor sections V 1 , V 2 , (FIG. 2) and a neutral transitory attitude can then be attained only when the second compressor section V 2 has a pressure ratio that is not higher than the pressure ratio of the first compressor section V 1 .
When gases possessing great isentropic exponents are utilized, the optimum pressure ratios for closed-cycle turbo-machine groups operating with a recuperator in the circuit will be small so that the storage tanks described above will have a relatively small effective pressure head only.
Another arrangement for controlling the quantity of the gaseous working medium circulating in the closed system which has been employed in an experimental turbo-machine plant utilizes a high-pressure gas intake, as illustrated in FIG. 3. The change-over behavior that can be attained by this arrangement when controlling the power output is very positive, and permits immediate load surges. Unfortunately, an auxiliary compressor is needed in order to charge the storage tank thus making the apparatus more complicated and more costly.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an improved method and related apparatus which will permit a gradual as well as a sudden load control without the need for providing expensive additional machine components. The invention solves the problem in that a storage tank for the gaseous working medium is connected in parallel with sectional portions of the closed gas circulating circuit and in such manner that hot or cold gas can flow selectively through the storage tank, with the result that due to the change in density of the gas stored within the tank, gas is either withdrawn from the gas circulating circuit or is delivered into that circuit.
It is advantageous if the gas flowing through the storage tank also flows through heating, or cooling, elements thereby making possible an increase in the range of control.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIGS. 1, 2, and 3 show in schematic form three different arrangements of a turbo-machine group representing the state of the prior art, each operating on a closed circuit type of gas circulation system and each with a different arrangement of a storage tank and means connected therewith for selectively removing gas from, or adding it to, the closed gas circuit;
FIGS. 4, 5, 6, and 8 are likewise illustrations in schematic form of four different arrangements of a turbo-machine group also operating on a closed circuit type of gas circulation system and each with a different arrangement of a storage tank and means connected therewith for selectively removing gas from, or adding it to, the closed gas circuit, in accordance with the invention; and
FIG. 7 is a graph depicting variation of the gas pressure as a function of its mass.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference now to the drawings, like components in all of the views have been identified by like reference symbols. Each of the turbo-machine groups include a compressor V, a gas turbine T, an electrical generator G, all coupled to the same shafting, as well as a pre-cooler VK, a heat exchanger R, a gas heater LE and a storage tank S. The gaseous working medium circulates through the system in a closed type of circuit and the direction of flow of the gas is indicated by arrows.
The basic gas flow circuit arrangement of the components V, T, VK, LE, and R is the same in all of the different figures. However, in one embodiment of the present invention according to FIG. 4, which operates by direct heating, or cooling, respectively, of the volume of gas within the storage tank S, it will be seen that connections with the tank extend (1) to a junction point in the gas circuit intermediate the pre-cooler VK and the inlet to compressor V by way of a control valve J, (2) to a point within compressor V intermediate its inlet and outlet by way of a control valve K, (3) to a junction point in the gas circuit intermediate heat exchanger R and pre-cooler VK by way of a control valve H 1 , and (4) to a junction point in the gas circuit intermediate heat exchanger R and the outlet side of gas turbine T by way of a valve H 2 . By opening valves K and H 1 , the storage tank S can be cooled and filled with gas of lower temperature. In this case, the gas content of the tank has the greatest possible density which means that the tank is in its charged state. The opposite effect is brought about by opening of the valves H 1 and J causing the temperature of the gas within the storage tank S to increase from e.g., 19° C. to 237° C., so that gas is forced out of the tank into the gas circulating system. In order to maintain a stable state within the system, only a very slight circulation of gas through the storage tank is needed to compensate for thermal losses. By opening valve H 2 rather than valve H 1 , the gas temperature within the storage tank can be increased--in the case of the example selected--to 540° C., resulting in a still greater rarefication of the gas within the tank. Naturally this rarefication is somewhat curtailed by the desired pressure rise within the gas circulating system, and consequently within the storage tank. If it is desired to accomplish in this manner a pressure rise, i.e., an enlargement of the gas filling in the circulation system by a factor of 1.4 while the temperature ratio is: ##EQU1## it is possible to shift 50% of the tank volume because: ##EQU2## wherein: m represents the gas mass within the tank
p represents the gas pressure within the tank
T represents the gas temperature within the tank.
However, instead of being connected into the gas circulation system at the low pressure side, the storage tank S can also be connected into the gas circulation system at the high pressure side as illustrated in the embodiment according to FIG. 5. In this embodiment, gas connections with the tank S extend (1) to the outlet side of compressor V by way of a valve E connected in series with a cooler C, (2) to a junction point in the gas circuit between the outlet side of gas heater LE and the inlet side of turbine T by way of a valve L, and (3) to a junction point in the gas circuit between heat exchanger R and the inlet side of gas heater LE by way of a valve F.
In accordance with the arrangement illustrated in FIG. 5 the gas content within tank S can be brought up to its greatest density by opening valve E and a flow of cold water through cooler C. If the cooling water is turned off, the gas temperature within the tank S will rise--in case of the example shown--to 178° C., so that gas will be forced from the tank into the circulation system.
However, if valve L is opened while valve E remains closed, gas at a temperature of 403° C. will flow through and fill the tank so that the gas density within the tank is reduced to a minimum and the gas content within the circulating system rises to a maximum. It is also feasible, but not necessary, to utilize blowers or injectors in lieu of the natural pressure gradient existing within the circulation system.
Obviously, this storage tank principle can also be combined with the prior art embodiments illustrated in FIGS. 1 and 2 and the storage tanks of the latter can then have smaller volumes. FIG. 6 illustrates an example of such a combination wherein connections with the tank S extend (1) to the outlet side of compressor V by way of a cooler C and valve P connected in series, (2) to a junction point in the gas circuit between heat exchanger R and the outlet side of turbine T by way of valve O, and (3) to a junction point in the gas circuit between heat exchanger R and the inlet to pre-cooler VK by way of a valve U.
When operating with minimum output from the turbo-set V, T, and G, i.e., the lowest output that can be set by means of this particular control method, a pressure compensation exists between the outlet of compressor V and tank S by way of valve P which is open. The gas temperature within tank S is assumed to be 19° C. At the low pressure side of the gas turbine circulating system a low pressure exists, and it is therefore possible, by closing valve P, and the subsequent opening of valve U to permit gas to flow out of tank S into the gas circulating system, in the example illustrated, ahead of the pre-cooler VK. Up to this point, the process control corresponds to those of FIGS. 1 and 2.
If valve Q is now opened, hot turbine gas will begin to flow into the tank S due to the flow resistance within the heat exchanger R, driving out the cold gas through valve U which is still open. This will result in a further lowering of the gas density within the tank and a corresponding further increase in density within the gas circulation system, and the power performance of the turbo-set V, T, G will, in this manner reach its maximum.
FIG. 7 illustrates these inter-related processes in a pressure/mass graph. The lines running from the upper right to the lower left depict respectively the pressures within the gas circulation system at the high-pressure side (HP) as well as at the low-pressure side (LP). The lines running from the upper left to the lower right indicate the pressures within the storage tank S.
The trace 1-2 is a line showing the gas discharge from a storage tank with a constant temperature of 19° C. If it is desired that 4,000 kg. of the gaseous medium, e.g., helium, flow out, beginning at point 1 and ending at point 2, the tank must have a volume of 1,520 m 3 .
If, however, at the end of the outflow process, the storage tank is heated and brought up to the temperature level at the turbine outlet, i.e., in the example shown, to 540° C., a tank volume of 850 m 3 will suffice for the delivery of 4,000 kg. of helium. The course of the gas discharge is now shown by the broken trace lines, namely, from 1 to 2' by the flowing out at a constant temperature, and from 2' to 2 by the driving out due to the rise in temperature.
It is thus demonstrated that in the case of the limiting conditions set in the example shown, the specific control offered by the invention make possible either (1) a reduction of the volume of the storage tank S by the factor: ##EQU3## or (2) an increase of the range of control by the reciprocal factor of 1.79 if the volume of the storage tank remains unchanged.
The principle of heating and cooling the gas storage tank by components which are placed in parallel with sectional portions of the closed gas circulation system can be realized indirectly, and FIG. 8 illustrates an embodiment of such a method. A helically formed tubing B located within the gas storage tank S is provided to heat, or cool, respectively, the gas within the tank. The storage tank gas pressure is thus no longer identical with the pressure of the gas flowing in the closed gas circulation system of the turbo-set. The tubing B is connected at one end by way of valve K to an intermediate point within the compressor V and also by way of a valve J to a junction point in the main gas circulation circuit intermediate the inlet to a pre-cooler VK and heat exchanger R. The other end of tubing B is connected by way of a valve H to a junction point in the main gas circulation circuit intermediate the outlet of turbine T and heat exchanger R. The interior of tank S is connected by way of valve A to a junction point in the main gas circulation circuit intermediate the outlet from compressor V and the heat exchanger R.
With the arrangement illustrated in FIG. 8 it will now be possible to connect the tubing B within the tank S by way of valves H, J, and K to the low-pressure side of the circulation system, while connecting the interior of storage tank S to the high-pressure side of the circulation system by way of valve A.
If valves K and H are open, cold gas, for example at a temperature of 35° C. will flow through the tubing B. The gas contained within tank S is cooled off and its pressure will drop, with the volume remaining constant. If valve A is opened, gas can then flow out from the circulation system until a pressure balance with the cold gas content of the tank is attained. The gas pressure of the circulation system which, at the beginning, amounts to 60 bar behind the compressor V, is thus lowered, and all other gas pressures within the circulation system are also lowered proportionally. The power output of the turbo-set is likewise reduced proportionally.
If valve A is now closed off and valve J is opened in place of valve K, with valve H remaining open, the gas content within the storage tank S is heated up while its volume remains constant, with the result that the gas pressure within the tank will rise. If valve A is now opened, an intensive outflow of gas from the tank into the high-pressure side of the gas circulation system will occur, causing a rapid increase of power output with a positive instantaneous effect, as required for example for the purpose of generator-frequency support. When using temperatures of 35° C. and 540° C. given in the example as a basis, it becomes possible to attain inside the storage tank S a pressure ratio of:
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An arrangement for controlling the power output of a closed cycle type of thermodynamic system including shaft-coupled compressor and gas turbine components driving a load such as an electrical generator in which the gaseous working medium flows in a closed circulation system that includes a device for imparting heat to the gas and a storage tank for the gas connected in parallel with a section of the gas circulation system. In order to vary the power output, gas from the circulation system in a cold or hot state, respectively, is flowed through the tank for heat exchange with the gas in the tank such that as a result of the corresponding change produced in the density of the gas within the tank, gas is selectively withdrawn from or delivered into the circulation system.
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BACKGROUND OF THE INVENTION
The present invention relates to a ceiling fan assembly and a method for assembling same, and, more particularly, to such an assembly and method in which the fan assembly can be assembled relatively easily and quickly using a minimum number of parts.
Rotating fans that are mounted to the ceilings of homes and businesses are very popular. These types of fans consist of a plurality of angularly-paced blades and a plurality of arms that connect the blades to the rotor portion of an electric motor mounted in a housing. Since the blades, arms and the motor are all manufactured and shipper separately, they must be assembled and mounted at the site. However, this assembly and mounting is relatively difficult and time-consuming since each blade is attached to its arm by a plurality of fasteners, and each arm is attached to the rotor end casing by a plurality of fasteners. Since there are usually five blades and arms, the labor costs involved in assembling and mounting the complete fan assembly constitutes a very high percentage of the overall cost of the assembly.
Therefore, what is needed is as fan assembly and a method of assembling same in which the fan blades can be easily and quickly attached to the arms, and the arms can be easily and quickly attached to the motor; thus considerably reducing the labor costs in assembling and mounting the fan assembly.
SUMMARY OF THE INVENTION
The present invention, accordingly, is directed to a ceiling fan assembly and method for assembling same in which a fan blade is placed over an arm having a post that extends in an opening in the blade. A fastener is attached to the post to secure the blade to the arm, and a flange on the arm is inserted in a slot in the rotor of the fan motor to retain the arm relative to the rotor.
Several advantages result from the assembly and the method of the present invention. For example, the use of a plurality of nuts, bolts and screws is eliminated and the blades can be connected to the arms, and the arms to the rotor, using a minimum of fasteners. As a result, the fan assembly can be assembled and mounted relatively easily and quickly thus considerably reducing the labor costs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric, exploded view of the fan assembly of the present invention.
FIG. 2 is an enlarged, isometric, exploded view of a portion of the fan assembly of FIG. 1.
FIG. 3 is a sectional view of a portion of the fan assembly of FIGS. 1 and 2.
FIG. 4 is an isometric, exploded view of an alternate embodiment of the fan assembly of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 of the drawings depicts the fan assembly of the present invention which is referred to, in general, by the reference numeral 10 and which consists of a housing 12 connected to a ceiling of a building by a mounting rod 14. It is understood that the mounting rod 14 is connected to the ceiling in any known manner, and that electrical conductors extend from an electrical box (not shown) mounted to the ceiling, through the rod, and into the interior of the housing 12. A conventional electrical motor is provided in the housing 12 that includes a stator (not shown) and a rotor that includes an end casing 16 that protrudes slightly from the lower surface of the housing, as viewed in FIG. 1. Five elongated blades 20 are mounted to the rotor end casing 16 by five mounting arms 22, respectively, and an internally threaded retainer ring 24 threadedly engages the casing and retains the arms in the casing, all in a manner to be described.
The details involving the connection of a blade 20 to its corresponding arm 22, and the connection of the latter arm to the rotor end casing 16 are better shown in FIG. 2. More particularly, the arm 22 includes a relatively wide mounting portion 22a that has openings extending therethrough to reduce its weight, a necked-down portion 22b one end of which extends from the portion 22a, and an arcuate flange 22c extending from the other end of the portion 22b and extending generally perpendicular thereto. A threaded post 22d and two guide pins 22e all extend from the upper surface of the arm portion 22a. Preferably, the arm portions 22a, 22b, and 22c, as well as the post 22d and the guide pins 22e are all molded integrally.
The corresponding end of the blade 20 has an enlarged opening 20a extending therethrough for receiving the post 22d, and two other openings 20b for receiving the two guide pins 22e, respectively. An internally threaded cap 26 is provided which engages the post 22d to retain the blade 20 to the arm 22, and a seal ring 28 extends between the lower surface of the post 22d and the inner wall of the blade 20 defining the opening 20a.
An annular slot 16a is defined in the rotor end casing 16 which receives the flange 22c of the arm 22 shown in FIG. 2 and the flanges of the other arms. Five angularly-spaced, axially-extending slots 16b are also formed in the rotor end casing 16 which respectively receive the necked-down portion 22b of the arm 22 shown in FIG. 2, and the necked-down portions of the other arms 22, in a friction fit. The rotor casing 16 also has an externally threaded cylindrical member 16c disposed immediately adjacent the slot 16a which is adapted for threaded engagement by the retainer ring 24 so that the ring can be threadedly connected to the member 16c and thus function to retain the flange 22c, and the flanges of the other arms 22, in the slot 16a.
As shown in FIG. 3, a counter bore is provided in the post 22d of the arm 22 which receives a ball 30, and a spring 32 extends between the ball and the bottom of the counter bore to urge the ball upwardly, as viewed in FIG. 3. FIG. 3 also depicts the blade 20 of FIG. 2 mounted on the arm 22, and the latter arm mounted in the rotor end casing 16. In this mounted position, the post 22d and the guide pins 22e of the arm 22 extend through the openings 20a and 20b, respectively, of the blade 20. Also, the cap 26 is in threaded engagement with the post 22d, and the ball 30 is urged upwardly against the inner upper surface of the cap 26 to tighten the threaded connection between the cap and the post. Also, the flange 22c of the arm 22 extends in the slot 16a of the rotor end casing 16, and the retainer ring 24 is in threaded engagement with the cylindrical member 16c of the casing to secure the arm 22 relative to the casing. It is understood that the other arms 22 and blades 20 shown in FIG. 1 are identical to the arm and blade shown in FIG. 2 and are connected together and mounted to the rotor end casing 16 in the same manner.
To mount the ceiling fan 10 to a ceiling, the rod 14 (FIG. 1) is connected to the ceiling in any known manner, and the housing 12 is connected to the rod with the lower portion of the rotor end casing 16 protruding slightly from the lower end of the housing 12 as shown in FIG. 1. The blades 20 are connected to the arms 22 by inserting the post 22d of each arm in the opening 20a of each blade, and inserting the guide pins 22e of each arm in the openings 20b, respectively, of each blade to align each blade relative to its corresponding arm. The cap 26 is then threaded over the post 22d to secure the blade 20 to the arm. Each arm 22, with its corresponding blade 20 attached thereto is then lifted up so that its flange 22c extends in a portion of the slot 16a and the arm portion 22b extends in its corresponding slot 16b in a friction fit, with the weight of the blade establishing a fulcrum that urges the flange into the slot. The retainer ring 24 is then threaded over the cylindrical portion 16c of the rotor end housing and the assembly is complete. As a result the fan assembly 10 is assembled and mounted in a very easy and quick manner utilizing a minimum of parts and effort.
The embodiment of FIG. 4 is very similar to that of FIGS. 1-3 and includes many of the same components of the latter embodiment, which are given the same reference numerals. According to the embodiment of FIG. 4, a fan assembly 10' is provided that includes an upper rotor end casing portion 36a and a lower rotor end casing portion 36b. The upper casing portion 36a is mounted in the housing 12 with its lower end exposed via an opening in the housing; and the lower casing portion 36b contains an annular flange, five angularly-spaced slots, and an externally threaded cylindrical portion identical to the annular flange 16a, the angularly-spaced slots 16b, and the externally threaded cylindrical portion 16c of the embodiment of FIGS. 1-3. The lower casing portion 36b is bolted to the upper casing portion 36a by a plurality of bolts 38 that extend through aligned openings in the casing portions 36a and 36b. Otherwise the embodiment of FIG. 4 is identical to that of FIGS. 1-3.
It is understood that variations may be made in the foregoing without departing from the scope of the invention. For example the number of blades 20 used in each embodiment can vary within the scope of the invention. Also, the post 22d and the guide pins 22e of each arm 22 can be fabricated separately and press fitted, or attached in any other known manner, to the arm. It is understood that other modifications, changes and substitutions are intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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A ceiling fan assembly and method for assembling same in which a fan blade is placed over an arm having a post that extends in an opening in the blade. A fastener is attached to the post to secure the blade to the arm, and a flange on the arm is inserted in a slot in the rotor of the fan motor to retain the arm, and therefore, the blade, relative to the rotor.
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[0001] This application claims the benefit of U.S. Patent Application No. 61/353,146, filed Jun. 9, 2010, which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This disclosure relates generally to methods of normalizing iron levels, treating iron deficiency and disorders related thereto, such as anemia. This disclosure also relates to pharmaceutical compositions effective for such treatments.
BACKGROUND OF THE INVENTION
[0003] Iron deficiency anemia is a common pathological manifestation in patients with chronic kidney disease (CKD) and is associated with significant increase in cardiac morbidity and mortality (see, e.g., Harnett et al., Am. J. Kidney Dis., 25, S3-S7, 1995; Xue et al., Am. J. Kidney Dis., 40, 1153-1161, 2002; Abramson et al., Kidney Int., 64, 610-615, 2003). Primary causes of anemia in CKD patients are iron deficiency and insufficient erythropoiesis (see, e.g., Eschbach, Kidney Int., 35, 134-148, 1989; Fishbane et al., Am. J. Kidney Dis., 29, 319-333, 1997). Iron deficiency may occur when body iron stores are depleted in CKD patients undergoing hemodialysis due to excess loss of blood. Iron deficiency may also occur due to inflammation induced low mucosal oral iron absorption and decreased mucosal iron transfer in CKD patients undergoing hemodialysis (see e.g., Kooistra et al., Nephrol. Dial. Transplant., 13, 82-88, 1998). Demand for iron is also increased in the production of red blood cells in response to the treatment with erythropoiesis stimulating agents (ESA) in CKD patients. Thus, iron deficiency is an inevitable consequence in patients undergoing hemodialysis and ESA treatment. Correcting iron deficiency is a necessary step for the treatment of anemia in CKD patients (see e.g., Silverberg et al., Kidney Int. Suppl., 69, S79-S85, 1999; Spinowitz et al., J. Am. Soc. Nephrol., 19, 1599-1605, 2008).
[0004] The oral iron absorption process occurs in two steps: (1) absorption of iron in the gut by the epithelial cells, and (2) transport of iron from the cells to the systemic circulation. In the first step, oral iron is absorbed and taken up by enterocytes in the proximal duodenum via the epithelial divalent metal ion transporter DMT1 (or DCT1) (see e.g., Gunshin et al., Nature, 388(6641), 482-488, 1997). Oral iron in the gut is first converted from Fe 3+ to Fe 2+ by a ferri-reductase enzyme and then binds to DMT1 for its transport into the epithelial cells. (2) In the second step, intracellular iron is either taken up by the ubiquitous iron protein ferritin and stored in the cytoplasm, or is transported into the circulation via the basolateral cell surface transporter ferroportin (see, e.g., Abboud et al., J. Biol. Chem., 275(26), 19906-19912, 2000; Donovan et al., Nature. 403(6771), 776-781, 2000). Release of iron to the circulation is tightly regulated by the peptide hepcidin secreted by liver. Hepcidin binds to ferroportin thereby initiating ferroportin endocytosis and lysosomal degradation (see, e.g., Nemeth et al., Science, 306(5704), 2090-3, 2004). Thus high expression of hepcidin lowers the distribution of ferroportin in the basolateral membrane thereby reducing the release of iron from the duodenal mucosal cells into the circulation.
[0005] The bioavailability of oral iron is limited by both the absorption efficiency of the enterocytes and hepcidin regulated release of iron from the mucosal cells. Although oral iron bioavailability was found to be approximately 22% in healthy subjects (see, e.g., Hansen et al., Phys. Med. Biol., 37(6), 1349-1357, 1992) this value will be significantly lower if the absorption and release of iron from the enterocytes is inhibited. Inflammatory cytokine IL-6, a product of macrophages activated by inflammation, is believed to upregulate hepcidin synthesis thereby limiting the release of intracellular iron (see, e.g., Nemeth et al., J. Clin. Invest., 113(9):1271-1276, 2004). Correlation between inflammatory cytokine IL-6 and poor oral iron absorption (reduced more than 60% based on serum iron AUC value) has been observed in patients suffering from Crohn's disease (see, e.g., Semrin et al., Inflamm. Bowel Dis., 12(12), 1101-1106, 2006). Inflammation is prevalent in CKD patients (see, e.g., Oberg et al., Kidney Int., 65(3), 1009-1016, 2004) and bioavailability of conventional oral iron formulation is severely affected primarily through the activation of inflammation-hepcidin pathway described above. Intravenous (IV) iron therapy, however, is effective in dialysis patients as it is able to circumvent the inflammation-hepcidin regulatory pathway by delivering iron directly to the circulation.
[0006] Current methods of oral iron therapy typically suffer from low bioavailability of the iron, making them ineffective for the treatment of anemia in CKD patients (see, e.g., Van Wyck et al., Kidney Int., 68, 2846-2856, 2005; Charytan et al., Nephron. Clin. Pract., 100, c55-c62, 2005). Thus, the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) has recommended the use of IV iron therapy as the primary means of correcting anemia in dialysis patients (see, e.g., NKF-KDOQI Clinical Practice Guidelines and Clinical Practice Recommendations for Anemia in Chronic Kidney Disease, 2007 update, www.guideline.gov (National Guideline Clearinghouse)). Anemia, however, is not limited to patients with CKD. Inflammation of the stomach lining such as in gastritis, or celiac disease, and any other abnormalities in the metal ion transporters responsible for iron transport renders oral iron absorption insufficient leading to anemia.
[0007] Thus, there is a continuing need to develop effective and well-tolerated oral treatments for patients with iron deficiency (for instance, anemic patients with CKD).
BRIEF SUMMARY OF THE INVENTION
[0008] The present inventors have developed new formulations for oral administration of iron that may be used as an effective therapy for the treatment of iron deficiency and disorders resulting from iron deficiency, such as anemia, for example, patients with CKD. The present formulations may provide an improved pharmacokinetic profile (e.g., enhanced extent and rate of absorption) when compared to conventional oral formulations. The application of this technology may be useful in reducing the GI discomfort and improving the safety because of the lower dose required due to enhancement of the bioavailability of iron. Moreover, the present formulations may act as an alternative to the current practice of IV iron therapy and thereby result in significant healthcare cost savings.
[0009] In one aspect, the present invention relates to a method of normalizing iron levels in a subject with iron deficiency by administering one or more oral dosage forms comprising a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)) and an iron compound.
[0010] In another aspect, the present invention relates to a method of improving the response rate of subjects to oral treatment with iron by administering one or more oral dosage forms comprising a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)) and an iron compound.
[0011] In yet another aspect, the present invention relates to a method of treating iron deficiency in a subject by administering one or more oral dosage forms comprising a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)) and an iron compound.
[0012] In yet another aspect, the present invention relates to a method of treating anemia in a subject by administering one or more oral dosage forms comprising a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)) and an iron compound.
[0013] In certain embodiments, the subject has chronic kidney disease. In other embodiments, the subject is undergoing dialysis. In further embodiments, the subject has Crohn's disease or IBD (Inflammatory Bowel Disease). In additional embodiments, the subject has cancer. In further embodiments, the subject has a gastric disorder (for example, inflammation of the stomach lining, such as in gastritis or Celiac disease). In one embodiment, the subject has autoimmune gastritis. In another embodiment, the subject has Helicobacter pylori gastritis. In one embodiment, the gastric disorder decreases nutrient absorption, resulting in insufficient absorption of the nutrient (e.g., iron).
[0014] In yet another aspect, the present invention relates to a pharmaceutical composition comprising (a) an iron compound and (b) a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)).
[0015] In yet another aspect, the present invention relates to a pharmaceutical composition comprising (a) an iron compound and (b) a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)) wherein the composition forms less than about 5% (e.g., less than 1%) by weight of an iron salt of the delivery agent (based on the total weight of the iron compound and the delivery agent in the initial pharmaceutical composition) after storage for 3 months at 25° C. and 60% relative humidity.
[0016] The pharmaceutical composition may further include one or more chelating complexing, or solubilizing agents, and/or anti-oxidants. The pharmaceutical composition may be an oral dosage unit form, such as a tablet or capsule. This pharmaceutical composition can be used in any of the aforementioned methods.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The term “about” or “approximately” means within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, i.e., the limitations of the measurement system. For example, “about” can mean within 1 or more than 1 standard deviations, per practice in the art. Alternatively, “about” with respect to the formulations can mean plus or minus a range of up to 20%, preferably up to 10%, more preferably up to 5%.
[0018] As used herein, the term “SNAC” refers to sodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid. SNAC is also known as sodium-N-salicyloyl-8-aminocaprylate, monosodium 8-(N-salicyloylamino) octanoate, N-(salicyloyl)-8-aminooctanoic acid monosodium salt, monosodium N-{8-(2 phenoxybenzoyl)amino}octanoate, E414 monosodium salt, sodium 8-[(2-hydroxybenzoyl)amino]octanoate and salcaprozate. SNAC has the structure:
[0000]
[0019] In additional embodiments of any of the methods described herein, NAC or other pharmaceutically salts of SNAC can be used in lieu of SNAC. For example, a disodium salt of NAC, as described in U.S. Pat. No. 7,384,982, may be used. Additionally, any solid state form of SNAC may be used. Suitable solid state forms of SNAC are described, for example, in U.S. Patent Publication No. 2009/0143330, which is hereby incorporated by reference.
[0020] In additional embodiments of any of the methods described herein, delivery agents other than SNAC (and its free acid or other pharmaceutically acceptable salts thereof) may be used in combination with an iron compound. Such delivery agents may either be combined with or used in lieu of NAC or its pharmaceutically acceptable salts. Examples of such delivery agents include, but are not limited to, N-(10-[2-hydroxybenzoyl]amino)decanoic acid (the free acid of SNAD), N-(8-[2-hydroxy-5-chlorobenzoyl]-amino)octanoic acid (5-CNAC), 4-[(2-hydroxy-4-chloro-benzoyl)-amino]butanoic acid (4-CNAB), 8-(2-hydroxyphenoxy)octyldiethanolamine (HPOD), 8-(N-2-hydroxy-4-methoxybenzoyl)-aminocaprylic acid (4-MOAC), 3-toluoxybutanoic acid (3-TBA) and pharmaceutically salts thereof (e.g., monosodium and disodium salts thereof). The term “SNAD” refers to the monosodium salt of N-(10-[2-hydroxybenzoyl-]amino)decanoic acid. Other suitable delivery agents are described, for example, in International Publication Nos. WO 96/30036, WO 98/34632, and WO 2007/121318 and U.S. Pat. Nos. 5,650,386, 5,773,647, and 5,866,536, all of which are hereby incorporated by reference.
[0021] The term “iron compound” refers to any member of a group of iron-containing compounds, which includes, but is not limited to, iron compounds in which the iron is in the +2 and/or +3 oxidation sate. For example, the iron compound may be ferrous sulphate (and its hydrates), ferrous fumarate, iron dextran, iron gluconate (ferric gluconate), iron sucrose, iron oxide, ferumoxytol, and any combination of any of the foregoing. In one embodiment, the iron present in the iron compound is in the +2 oxidation state. In one embodiment, the iron compound is ferrous sulfate or a hydrate thereof (e.g., ferrous sulfate heptahydrate).
[0022] In one embodiment, ion exchange between the iron compound and the delivery agent that results in the formation of an iron salt of the delivery agent is to be minimized. For example, a pharmaceutical composition comprising the iron compound and delivery agent forms less than about 5%, less than about 4%, less than about 3%, less than about 2%, less than about 1%, less than about 0.5%, or less than about 0.2% by weight of an iron salt of the delivery agent (based on the total weight of the iron compound and the delivery agent in the initial pharmaceutical composition), for example, after storage for 1, 2, or 3 months at 25 ° C. and 60% relative humidity.
[0023] In another embodiment, less than about 5%, less than about 4%, less than about 3%, less than about 2%, less than about 1%, less than about 0.5% or less than about 0.2% by weight of the delivery agent in the pharmaceutical composition is in the form of an iron salt.
[0024] In further embodiments, pharmaceutical compositions for use in any of the methods described herein may include one or more additional compounds that increase the solubility of the iron compound. Suitable additional compounds include, but are not limited to, compounds that chelate to the iron compound (chelating agents), such as citric acid, complexation agents (cyclodextrins), or solubilizing agents (surfactants). Suitable formulation methods to increase the solubility include, but are not limited to, the use of micronized material or the use of the amorphous form (spray drying/ freeze drying)
[0025] In further embodiments, pharmaceutical compositions for use in any of the methods described herein may include one or more additional compounds that increase duodenal ferri-reductase activity, thereby aiding in intestinal absorption of iron. Suitable additional compounds include, but are not limited to, ascorbic acid.
[0026] In further embodiments, pharmaceutical compositions for use in any of the methods described may herein include one or more antioxidants, such as, but not limited to, ascorbic acid, propyl gallate, and any combination thereof.
[0027] In further embodiments, pharmaceutical compositions that may improve bioavailability, such as modified release products using polymers, bilayer (or trilayer) tablets for a more consistent absorption profile, permeation enhancers, extrusion-spheronization to improve the rate of drug/carrier release from the dosage form, may also be used.
[0028] For example, in one embodiment, the pharmaceutical composition may be in the form of a bi- or tri-layer tablet having the following structure:
[0029] a) a first layer 1 having the property of swelling considerably and quickly on contact with aqueous biological fluids (in one embodiment, the first layer is produced by compression of a mixture or of a granulate comprising hydrophilic polymers constituting from about 5 to 90% (e.g., from about 10 to about 85%) of the weight of the layer);
[0030] b) a second layer 2 adjacent to the first layer, in which the iron compound (e.g., ferrous sulphate) and delivery agent (e.g., SNAC) are conveyed (in one embodiment, the second layer is formulated with hydrophilic polymers and with other auxiliary substances, in order to give the preparation suitable properties of compressibility and in order to allow the release of iron compound and delivery agent within a predetermined time period); and
[0031] c) optionally a third layer 3 obtained by compression and applied to layer 2, (in one embodiment, the third layer contains hydrophilic polymers which gel and/or swell and which may then optionally be broken down and having a barrier function which modifies the release of the iron compound and delivery agent from layer 2, layer 3 being primarily highly impervious to passage of the active substance.
[0032] In certain embodiments, on contact with gastric juices, after rapid and considerable swelling of at least one of layers 1 or 3, as well as by the possible swelling of layer 2, the pharmaceutical composition increases considerably in volume; thus, the pharmaceutical preparation remains in the stomach for longer. In this way, most of the iron compound and delivery agent contained may be absorbed in a controlled manner in that portion of the gastrointestinal tract which has the highest capacity for absorption of iron.
[0033] In one embodiment, layers 1 and 3 have an identical composition and identical functional properties. In another embodiment, layers 1 and 3 have a different composition and different properties. When the layers 1 and 3 have identical functional properties and compositions, they may differ by their amounts and their thicknesses applied to the layer 2.
[0034] In one embodiment, at least one of layers 1 and 3 acts as a barrier that it is primarily highly impervious to passage of the iron compound and delivery agent contained in layer 2 and at least one of the layers is characterized in that it swells quickly, i.e., quickly increases in volume.
[0035] In another embodiment, the pharmaceutical composition is a tablet containing 3 layers comprising a first layer 1 as described above, whose function is to increase considerably in volume on contact with aqueous liquids; a second layer 2 conveying some of the iron compound and delivery agent which has to be released within a predetermined time period; and a third layer 3 in which some of the iron compound and delivery agent are conveyed, formulated such that it can be released immediately on contact with gastric juices.
[0036] In further embodiments, the polymeric substances which are used in the layers 1 and 3, and which may also be used in the layer 2, are biocompatible and have hydrophilic properties. For example, they are slowly soluble and/or slowly gelable and/or swell rapidly or at a different rate in aqueous liquids and then may optionally be broken down.
[0037] Suitable examples of hydrophilic polymers include, but are not limited to, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose having a molecular weight of from about 1000 to about 4,000,000, hydroxypropylcellulose having a molecular weight of from about 2000 to about 2,000,000, carboxyvinyl polymers, chitosans, mannans, galactomannans, xanthans, carrageenans, amylose, alginic acid, its salts and its derivatives, pectins, acrylates, methacrylates, acrylic/methacrylic copolymers, polyanhydrides, polyamino acids, poly(methyl vinyl ether/maleic anhydride) polymers, polyvinyl alcohols, glucans, scleroglucans, carboxymethylcellulose and its derivatives, ethylcellulose, methylcellulose, hydrophilic cellulose derivatives, and combinations thereof.
[0038] In one embodiment, the content of hydrophilic polymers ranges from about 5 to about 90% relative to the total weight of the layer, (e.g., from about 10 to about 85%, such as from about 20 to about 80%).
[0039] In further embodiments, in order to promote a rapid and considerable increase in the volume of the pharmaceutical preparation, during the preparation of the layers 1 and 3 with the hydrophilic polymers described above, it is possible to use hydrophilic products and/or excipients capable of promoting wetting of the layers, in this way facilitating interaction between the components of the said layer and the biological fluids with which the layer comes into contact. For example, these hydrophilic excipients may include crosslinked polyvinylpyrrolidone, hydroxypropylcellulose and hydroxypropylmethylcellulose having a molecular weight from about 1,000 to about 100,000, crosslinked sodium carboxymethylcellulose, carboxymethyl starch and its salts, divinylbenzene/potassium methacrylate copolymer, and combinations thereof.
[0040] In one aspect, the present invention relates to a method of increasing or normalizing iron levels in a subject with low iron levels by administering one or more oral dosage forms comprising a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)) and an iron compound.
[0041] In another aspect, the present invention relates to a method of improving the response rate of subjects to oral treatment with iron by administering to each subject one or more oral dosage forms comprising a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)) and an iron compound. In certain embodiments, the subject suffers from low iron or iron deficiency.
[0042] In yet another aspect, the present invention relates to a method of treating iron deficiency in a subject by administering one or more oral dosage forms comprising a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)) and an iron compound.
[0043] In yet another aspect, the present invention relates to a method of treating anemia in a subject by administering daily one or more oral dosage forms comprising a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)) and an iron compound.
[0044] In certain embodiments, the subject has chronic kidney disease. In other embodiments, the subject is undergoing dialysis. In further embodiments, the subject has Crohn's disease. In additional embodiments, the subject has cancer. In further embodiments, the subject has a gastric disorder (for example, inflammation of the stomach lining, such as in gastritis or Celiac disease). In one embodiment, the subject has autoimmune gastritis. In another embodiment, the subject has Helicobacter pylori gastritis. In one embodiment, the gastric disorder decreases nutrient absorption, resulting in insufficient absorption of the nutrient (e.g., iron).
[0045] In additional embodiments, any of the methods described herein achieve a patient response rate and/or efficacy similar to that observed for intravenous administration.
[0046] In additional embodiments of any of the methods described herein, the one or more dosage forms are administered daily. In additional embodiments of any of the methods described herein, the one or more dosage forms are administered once a week. In additional embodiments of any of the methods described herein, the one or more dosage forms are administered once every two weeks. In additional embodiments of any of the methods described herein, the one or more dosage forms are administered once a month.
[0047] The pharmaceutical compositions and dosage forms may further include one or more chelating agents and/or anti-oxidants, as described above.
[0048] In yet another aspect, the present invention relates to a pharmaceutical composition comprising (a) an iron compound and (b) a delivery agent (e.g., N-[8-(2-hydroxybenzoyl)amino]caprylic acid (NAC) or a pharmaceutically acceptable salt thereof (such as monosodium N-[8-(2-hydroxybenzoyl)amino]caprylic acid (SNAC)).
[0049] The pharmaceutical composition may further include one or more chelating agents and/or anti-oxidants. This pharmaceutical composition can be used in any of the aforementioned methods.
[0050] In additional embodiments of any of the methods described herein, the patient can be one who has failed to respond to existing oral iron treatment (or, for instance, oral treatment with an iron containing formulation which does not include a delivery agent, such as SNAC).
[0051] In further embodiments of any of the methods described herein, the present invention relates to the administration of a tablet dosage form.
[0052] The weight ratio and amount of iron and delivery agent (e.g., SNAC, or other form of NAC) can be as described herein. One of ordinary skill in the art would readily be able to determine the amount of iron present in a formulation based on the amount of a particular iron compound used. For example, 300 mg of ferrous sulfate heptahydrate is equivalent to about 60 mg of iron.
[0053] In some embodiments, the oral pharmaceutical composition includes from about 1 to about 1000 mg, from about 1 to about 500 mg, from about 1 to about 300 mg, from about 1 to about 200 mg, from about 5 to about 100 mg, from about 25 to about 500 mg, from about 10 to about 1000 mg, from about 25 to about 250 mg, from about 30 to about 800 mg, from about 50 to about 500 mg, from about 50 to about 250 mg, from about 50 to about 100 mg, from about 100 to about 1000 mg, from about 100 to about 500 mg, from about 250 to about 750 mg, or from about 250 to about 500 mg of iron.
[0054] In additional embodiments, the oral pharmaceutical composition includes about 10 mg, about 25 mg, about 50 mg, about 75 mg, about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, or about 500 mg of iron.
[0055] In one embodiment, the oral pharmaceutical composition includes from about 1 mg to about 500 mg of iron and from about 1 mg to about 1000 mg of delivery agent (e.g., SNAC).
[0056] In one embodiment, the oral pharmaceutical composition includes from about 5 mg to about 100 mg of iron and from about 50 mg to about 300 mg of delivery agent (e.g., SNAC).
[0057] In another embodiment, the oral pharmaceutical composition includes from about 100 mg to about 1000 mg of iron and from about 250 mg to about 10000 mg of delivery agent (e.g., SNAC).
[0058] In additional embodiments, the dosage form, such as a tablet dosage form, may contain from about 1 mg to about 500 mg of iron and from about 10 mg to about 600 mg of delivery agent (e.g., SNAC). For example, the dosage form may contain from about 25 mg to about 500 mg of iron or from about 25 mg to about 300 mg of iron or from about 50 mg to about 200 mg of iron and from about 10 mg to about 500 mg of delivery agent (e.g., SNAC), or from about 25 mg to about 400 mg of delivery agent (e.g., SNAC) in each tablet.
[0059] In one embodiment, the dosage form, such as a tablet dosage form, contains from about 30 mg to about 150 mg of iron and about 50 mg to about 300 mg of SNAC.
[0060] In one embodiment, the dosage form, such as a tablet dosage form includes from about 1 mg to about 200 mg of iron and the dosage form is administered twice a day.
[0061] In another embodiment, the dosage form, such as a tablet dosage form includes from about 100 mg to about 1000 mg of iron and the dosage form is administered once a month.
[0062] In other embodiments, the weight ratio of iron to delivery agent (e.g., SNAC) is from about 2:1 to about 1:700, such as from about 1:2 to about 1:600, from about 1:2 to about 1:200, from about 1:2 to about 1:100, from about 1:3 to about 1:20 or from about 1:4 to about 1:10. In one embodiment, the weight ratio of iron to of delivery agent (e.g., SNAC) is about 1 to 100.
[0063] In other embodiments, the dosage form (e.g., a tablet) optionally contains excipients, emulsifiers, stabilizers, sweeteners, flavoring agents, diluents, coloring agents and/or solubilizing agents, or any combination thereof. Suitable excipients, emulsifiers, stabilizers, sweeteners, flavoring agents, diluents, coloring agents, and solubilizing agents include those described in the Handbook of Pharmaceutical Excipients (fourth edition) by Raymond C. Rowe, Paul J. Sheskey and Paul J. Weller.
[0064] Exemplary formulations according to the present invention are provided in the tables below. The formulations may contain one or more additional excipients in addition to those identified in the tables.
[0000]
Exemplary Immediate Release Formulations for Twice Daily
Administration
Amount
Amount
Amount
Ingredient
(mg)
(mg)
(mg)
SNAC
1-500
20-400
50-300
Iron
1-300
1-200
5-100
(from an iron
compound such as
ferrous sulfate)
Citric acid
10-400
20-300
50-200
Ascorbic acid
10-400
20-300
50-200
Propyl gallate
10-400
20-300
20-150
Pre-gelatinized
10-500
20-200
20-150
starch
Microcrystalline
1-500
1-200
2-150
cellulose
Povidone
1-100
1-75
1-50
Dibasic calcium
10-500
20-200
20-150
phosphate
[0000]
Exemplary Modified Release Formulations for Once Monthly
Administration
Amount
Amount
Amount
Ingredient
(mg)
(mg)
(mg)
SNAC
10-5000
30-2000
50-1000
Iron
10-1000
25-800
50-500
(from an iron
compound such as
ferrous sulfate)
[0000]
Exemplary Bi- and Tri-Layer Tablets
Layer 3
Layer 1
Layer 2
(Optional)
Ingredients
Hydroxypropyl
Iron compound
Hydroxypropyl
methylcellulose
(e.g., ferrous sulfate)
methylcellulose
Hydrogenated
Delivery agent
Hydrogenated
castor oil
(e.g., SNAC)
castor oil
Ethyl cellulose
Mannitol
Polyvinylpyrrolidone
Magnesium stearate
Hydroxypropyl
Magnesium stearate
methylcellulose
Silica gel
Polyvinylpyrrolidone
Colloidal silica
Microcrystalline cellulose
Magnesium stearate
Colloidal silica
[0065] Bi- and tri-layer tablets may be prepared by the methods described in U.S. Pat. No. 6,149,940, which is incorporated by reference in its entirety.
[0066] Bioavailability of conventional iron formulations depends on the iron uptake efficiency of the diavalent metal transporter DMT1 mediated duodenal mucosal absorption and ferroportin dependent transfer of mucosal iron to the circulation. Without intending to be bound by any particular theory of operation, it is believed that in addition to this normal pathway of oral iron absorption, the oral dosage forms described herein may use an alternate absorption pathway (passive transport) independent of either DMT1 mediated iron uptake or ferroportin mediated iron transfer.
[0067] The term “treatment” or “treating” means any treatment of a disease or disorder in a mammal, including: preventing or protecting against the disease or disorder, that is, causing the clinical symptoms not to develop; inhibiting the disease or disorder, that is, arresting or suppressing the development of clinical symptoms; and/or relieving the disease or disorder, that is, causing the regression of clinical symptoms.
[0068] A subject or patient in whom administration of the oral pharmaceutical composition is an effective therapeutic regimen for a disease or disorder is preferably a human, but can be any animal, including a laboratory animal in the context of a trial or screening or activity experiment. Thus, as can be readily appreciated by one of ordinary skill in the art, the methods and compositions of the present invention are particularly suited to administration to any animal, particularly a mammal (e.g., a human), and including, but by no means limited to, humans, domestic animals, such as feline or canine subjects, farm animals, such as but not limited to bovine, equine, caprine, ovine, and porcine subjects, wild animals (whether in the wild or in a zoological garden), research animals, such as mice, rats, rabbits, goats, sheep, pigs, dogs, cats, etc., avian species, such as chickens, turkeys, songbirds, etc., i.e., for veterinary medical use.
[0069] The following examples are given as specific illustrations of the invention. It should be understood, however, that the invention is not limited to the specific details set forth in the examples. All parts and percentages in the examples, as well as in the remainder of the specification, are by weight unless otherwise specified.
[0070] Further, any range of numbers recited in the specification or paragraphs hereinafter describing or claiming various aspects of the invention, such as that representing a particular set of properties, units of measure, conditions, physical states or percentages, is intended to literally incorporate expressly herein by reference or otherwise, any number falling within such range, including any subset of numbers or ranges subsumed within any range so recited.
EXAMPLE 1
Preparation of N-[8-(2-hydroxybenzoyl)amino]caprylic acid and SNAC
[0071] The preparation method for N-[8-(2-hydroxybenzoyl)amino]caprylic acid and SNAC involves the following steps: The starting material is salicylamide, which is converted to form carsalam (1,3-benzoxazine-2,4-dione). The second step involves the alkylation of carsalam. The penultimate step is a hydrolysis to cleave the ethyl protection group at the end of the alkyl chain and open the heterocyclic ring forming the free acid of SNAC. In the final step, the sodium salt of the SNAC free acid is formed by reaction with a 1% excess stoichiometric amount of sodium hydroxide base. Upon cooling the precipitated product is isolated by centrifugation and vacuum dried prior to packaging. The in-process controls for the synthetic scheme are given in Table 1.
[0000]
TABLE 1
In-process controls for SNAC Manufacturing Process.
Desired
In-Process
Step
Reaction
Product
Specification
Control
1
Carsalam
Carsalam
<10%
HPLC
salicylamide
2
Alkylation
Alkylated
<8% carsalam
HPLC
carsalam
3
Hydrolysis
SNAC free acid
<0.5%
LOD
4
Sodium Salt
SNAC sodium
95-105%
HPLC
salt
EXAMPLE 2
A Single Dose Pharmacokinetic Study In Normal Dogs
[0072] A single dose pharmacokinetic study in four normal (i.e., non-anemic) dogs will be conducted to test various ferrous sulphate/SNAC containing pharmaceutical compositions according to the present invention. The pharmacokinetic and bioavailability data will be compared with that obtained using a commercial iron supplement therapy formulation (Feosol®, ferrous sulphate tablets). Details of the proposed dog study (Dog Study 1) are shown in Table 1.
[0000]
TABLE 1
Proposed Formulations For Use In Dog Study 1
Formulation 1
Formulation 2
Formulation 3
Formulation 4
Formulation 5
Formulation 6
(Solution)
(Tablet)
(Tablet)
(Tablet)
(Tablet)
(Tablet)
Ferrous
Conventional
Ferrous
Ferrous
Ferrous
Ferrous
sulfate
Ferrous
sulfate
sulfate
sulfate
sulfate
Intravenous
sulfate tablet
(Feosol ®)
SNAC
SNAC
SNAC
SNAC
Citric acid
Citric acid
Citric acid
(chelator)
(chelator)
(chelator)
Ascorbic
Ascorbic
acid (anti
acid (anti
oxidant and
oxidant and
iron
iron
absorption
absorption
promoter)
promoter)
Propyl
gallate (anti-
oxidant)
Optimization Of Composition
[0073] The effectiveness of the chelator and anti-oxidant in the formulations will be assessed based on the results of Dog Study 1. For example, if Formulation 3 proves to be the best performing tablet formulation, then it may be necessary only to adjust the SNAC to ferrous sulfate ratio in order to achieve an optimum formulation without the addition of a chelator or anti-oxidant. Alternatively, if Formulation 5 performs the best among all the tablet formulations, then it may be necessary to adjust the amount of ascorbic acid in order to achieve an optimum formulation for oral bioavailability of iron.
Dose Optimization
[0074] Based on the results of the Dog Study 1, either Formulation 3 or a variant of Formulation 4, 5, or 6 will be selected for a follow-up study to select the optimum ratio of SNAC and ferrous sulfate to ensure optimum oral absorption. Three ratios of SNAC and ferrous sulfate will be used in a second dog study (Dog Study 2). Suitable SNAC-iron formulations for Dog Study 2 are shown in Table 2 below.
[0000]
TABLE 2
Proposed Ferrous Sulfate and Escalating SNAC Dose in Normal Dogs
(Dog Study 2)
Formulation 7
Formulation 8
Formulation 9
(Tablet)
(Tablet)
(Tablet)
Ferrous Sulfate
Ferrous Sulfate
Ferrous Sulfate
SNAC Dose 1
SNAC Dose 2
SNAC Dose 3
[0075] Based on the outcome of Dog study 2, a further optimized SNAC-ferrous sulfate ratio will be selected for future study in an anemic dog model.
Pharmacokinetic and Bioavailability Analysis
[0076] In Dog Studies 1 and 2, each dog will be dosed with the selected formulation and blood samples will be collected. Blood samples will be analyzed for total iron content and also for total iron binding capacity (TIBC) for pharmacokinetic analysis and iron status determination.
[0077] The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein, however, is not to be construed as limited to the particular forms disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art, without departing from the spirit of the invention.
[0078] The contents of all patents and publications cited herein are hereby incorporated herein by reference in their entireties, to the extent permitted.
|
Methods of normalizing iron levels, treating iron deficiency and disorders related thereto, such as anemia, as described. Pharmaceutical compositions effective for such treatments are also described.
| 0
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TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates to a receiver for urine samples and also to a female urination receiver.
BACKGROUND ART
[0002] Urine is an important diagnostic tool for measuring health and well-being of patients. The clinical information obtained from a urine specimen is influenced by the collection method, timing and handling.
[0003] A midstream clean catch Specimen is the preferred type of specimen for culture and sensitivity testing because of the reduced incidence of cellular and microbial contamination.
[0004] However, despite the importance of urine samples, their method of collection is very seldom conducted within the required protocols of hygiene and sterility.
[0005] In fact, urine samples are generally obtained by direct urination into a sample bottle or via a jug or the like into such a bottle with neither the jug nor the sample bottle being stored under sterile conditions. The collection of the sample may be accompanied by spillage or overflow and is generally unhygienic.
[0006] Furthermore, urine samples obtained in this way generally include the initial flow of excreted urine, which may not be as representative a sample as a sample from the middle of an excretion. The initial sample may include bacteria or other microorganisms that are not actually present in the urine. It is preferable to obtain a mid-stream urine flow for the purposes of obtaining more precise results.
[0007] Due to the above identified problems, even the simple dipstick tests conducted in a Doctors Surgery room can yield unreliable results.
[0008] In addition to the above, there is also a need for a urinating receiver that conforms to the shape of the female anatomy, and that can be used in a variety of instances, where access to a lavatory is limited. For example, during a long motorcar trip or even on a walking trip, or for Post-operative conditions as well as incontinence which provide serious difficulties for female sufferers.
[0009] It is an object of this invention to provide a urine receiver that, at least partially, alleviates some of the above mentioned problems.
DISCLOSURE OF THE INVENTION
[0010] According to the invention a urine receiver essentially for females is provided which includes an open top of saddle shape which at least approximates the configuration of the inside of the thighs, labia, or other convenient zone.
[0011] The receiver may be provided with a handle such as a jug handle as well as a spout for easy disposing of the contents.
[0012] The receiver may also have a closable outlet located in the base for discharge of the contents, or for collecting samples of urine.
[0013] The outlet closure may include a retractable plug.
[0014] A sample container may be attachable to the outlet for collecting the urine sample.
[0015] The sample container and the outlet may comprise a bayonet joint so that the sample container may be easily connected and disconnected from the receiver.
[0016] The bayonet joint is comprised of one or more protrusions located about the outer circumference of the lower end of the receiver, on one hand, and a channel formed proximal to the upper end of the sample container. The channel may further include one or more transverse grooves, preferably two transverse grooves. The protrusions accordingly engage not only the channel itself but also the transverse grooves, thereby ensuring that the sample container not only remains connected to the receiver, but also ensuring that the sample container is not rotated past a specific point, engagement with the grooves providing a positive indication of required steps in the attachment of the sample container to the receiver.
[0017] Connection of the sample container to the outlet of the receiver may cause the plug to be retracted into an open position, allowing the urine to drain into the sample container.
[0018] The sample container may be a special purpose sterile container, sealed by a membrane that is pierced on connection of the container to the receiver. Alternatively, and in another embodiment of the invention the sample container may be a standard, non sterile sample bottle. The sample container may additionally include a lid for sealing the container once the sample has been obtained.
[0019] The sample container may be fully inserted from the bottom of the receiver. Once inserted, the membrane will be pierced, and this may be identifiable by a positive clicking sound, which would be the protrusion of the receiver engaging the groove of the channel of the bayonet joint. This engagement may resist the sample container from being removed from the receiver without adequate force. At this point the protrusion of the receiver is engaged in the first groove in the channel of the bayonet joint. The sample container may then be rotated, causing the membrane to be cut approximately half way around the opening of the sample container. This may be again identifiable by a further positive clicking sound, being the protrusions of the receiver engaging a further groove in the channel of the bayonet joint. At this point the protrusion of the receiver is engaged in the second groove in the channel of the bayonet joint. This engagement may resist the further rotation of the sample container. The sample container may then be inserted further into the receiver and the membrane will be cut further.
[0020] A sample can now be taken, and the sample container lies at the outlet of the receiver. Pressure applied to the sample container will allow for the sample container to be filled by the urine collected in the receiver. The sample container is pushed against the retractable plug and a spring is activated to allow for the plug to open and urine begins to fill into the sample container. When pressure is released, the spring will bias the retractable plug into the original closed position and urine will stop flowing from the receiver.
[0021] The sample container may then be removed by twisting it in the opposite direction as to insertion.
[0022] Alternatively, the sample container may be connected to the outlet by a threaded screw connection.
[0023] The sample container includes a cross member which breaks the surface tension of the sample and this prevents any drops from being left behind once the sample container is removed from the receiver.
[0024] In order to provide instant pH and other pertinent detection, the receiver may include a holder for litmus or other indicators, and a suitable spillage protector for the spout.
[0025] The holder may include channels located along the interior wall of the receiver, alternatively the holder may include a separate insert receivable in the receiver. The insert may be shaped to additionally support a filter and/or sponge conforming in shape to the inside of the receiver, for absorbing the initial stream of urine and prevent unwanted ingress of microorganisms or other dirt.
[0026] The sponge may be constructed of cellulose or other absorbable material.
[0027] The insert may be located on a ledge extending around the interior of the receiver and may include a solid base sloping towards an aperture through which the urine not absorbed by the sponge, may flow.
[0028] The walls of the receiver may be transparent to allow the indicator strip to be viewed without removing it from the receiver.
[0029] A replaceable rim element adapted to fit the rim and to form a seal with the zone during use, may also be provided.
[0030] The rim element may be flexible as well as compressible so that it can seal well with a minimum of pressure being applied.
[0031] This avoids, or at least minimises soiling of the user's hands, clothes and surrounding floor, furniture and the like.
[0032] Where the receiver is to be used by various different users over a period of time, a new rim element may be provided for each new user, thus improving hygienic conditions.
[0033] A support base may be provided, on which the receiver may be located when not in use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] An embodiment of the invention is described below with reference to the accompanying drawings, in which:
[0035] FIG. 1 is an isometric projection of the receiver including the lid and support base,
[0036] FIG. 2 is a side view of the receiver located on the support base,
[0037] FIG. 3 is a top view of the receiver according to the invention,
[0038] FIG. 4 is a bottom view,
[0039] FIG. 5 is a top view of the filter/sponge insert,
[0040] FIG. 6 is a view of a sample bottle for use with the receiver,
[0041] FIG. 7 is an exploded view of a further embodiment of the invention,
[0042] FIG. 8 is a view of a second embodiment of the sample container, and
[0043] FIG. 9 is a view of the cross member of the sample container.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] In the drawings, a receiver 10 includes a saddle-shaped opening 12 with a rim 14 . The receiver includes a pouring spout 20 and a handle 22 .
[0045] A lid 16 is also provided to seal the receiver 10 and prevent spillage or contamination of the contents during the time lapse between providing the sample and testing of the sample.
[0046] The receiver 10 is mounted on a support base 18 by a bayonet joint so that it is easily attached and removed when necessary.
[0047] Referring to FIGS. 3 and 4 , an outlet 19 is located at the base of the receiver 10 , for draining the urine away.
[0048] The outlet 19 includes a plug 24 biased in the closed position by a spring (not shown) and openable from the exterior of the receiver 10 .
[0049] Referring to FIG. 5 , an insert 30 for supporting a filter pad and/or sponge (not shown) is removably located inside the receiver 10 , referring to FIG. 5 , the insert includes a solid base 32 , that slopes towards an aperture 34 , through which the overflow urine (mid-stream urine) may flow, once the initial drops of urine have been absorbed by the sponge/filter (not shown). The insert additionally includes a channel shaped extension 36 for receiving an indicator strip, commonly referred to as a “dip stick” such as litmus. The insert includes a spillage protector 38 for covering the spout opening.
[0050] Referring to FIG. 6 , a sample container 40 is attachable to the receiver outlet 16 for collecting the urine sample. The container 40 and the outlet 19 comprise a bayonet joint indicated by reference 42 so that the sample container may be easily connected and disconnected to and from the receiver.
[0051] The bayonet joint 42 comprises a channel 66 with various transverse grooves 68 located in the channel. The channel 66 typically includes two transverse grooves 68 . The transverse grooves 68 of the channel 66 engage protrusions 70 defined by the receiver 10 , thereby ensuring that the sample container 40 remains in a connected state to the receiver 10 and furthermore, ensuring that the sample container 40 is not rotated past a specific point.
[0052] In an alternative embodiment of the invention (not shown) the sample container may be connected to the outlet by a threaded screw connection.
[0053] Connection of the sample container 40 to the outlet 19 causes the plug 24 to be pushed up into an open position, allowing the urine to drain into the sample container 40 .
[0054] In this embodiment of the invention, the sample container 40 is a special purpose sterile container, sealed by a membrane (not shown) that is pierced on connection of the container to the receiver 10 . The sample container additionally includes a rubber lid 44 for sealing the container once the sample has been obtained.
[0055] Alternatively, and in another embodiment of the invention the sample container may be a standard, non sterile sample bottle.
[0056] A rim element (not shown) that has the same shape as the rim and has a channel to engage the rim may be removably located on the rim 12 . The element includes a channel that fits over the rim 12 of the receiver.
[0057] The element is both flexible and compressible so that an excellent seal is achieved in the zone of application, as described above, with minimum pressure having to be applied. In addition the degree of compression provides that the element seals with a large variety of configurations of the zone so that it can be used for a large number of different females. It may be necessary to provide a junior-size receiver.
[0058] It will be appreciated that the receiver 10 of the invention may be also conveniently used by males, in which case the rim element is not necessary.
[0059] In use, according to one embodiment of the invention, when a urine sample is required, a patient will be handed the sterilised receiver, into which the insert 30 containing new dipstick and cellulose sponge has been inserted. The outlet of the receiver will be in the closed position.
[0060] The patient will void her/his bladder into the receiver 10 , and cover the receiver with the lid 16 . The full receiver will be handed to the doctor or nurse, who will be able to see the dipstick through the transparent wall of the receiver 10 .
[0061] Should further testing be required by a laboratory, the doctor or nurse will attach a sample container 40 to the outlet 19 of the receiver, via the bayonet joint 42 , piecing the protective membrane on the sample container and opening the plug 24 in the process. In this manner, the urine drains into the sample container. Once the sample container 40 is full the container is removed from the receiver and the plug is biased back into its closed position by the outlet spring, preventing leakage of excess urine, which may be disposed of into a suitable receptacle when convenient. The sample container is sealed with the rubber stopper lid 44 and sent for further testing.
[0062] In an embodiment of the invention, as shown in FIGS. 7 and 8 , and when in use, the sample container 40 is inserted from the bottom of the receiver 10 . Once inserted, the membrane (not shown) is pierced, and this may cause a positive clicking sound which is the protrusions 70 of the receiver 10 engaging the grooves 68 of the channel 70 of the bayonet joint 42 . The sample container 40 will then be twisted, which causes the membrane to be cut approximately half way around the opening of the sample container 40 . This causes a further positive clicking sound which is the protrusion 70 of the receiver 10 engaging a further groove 68 of the channel 66 of the bayonet joint 42 . The sample container 40 is then inserted further into the receiver 10 and the membrane will be cut further. At this stage there is a further positive clicking sound that is heard and felt.
[0063] A sample is taken, and the sample container 40 lies at the outlet 19 of the receiver 10 . Pressure applied to the sample container 40 allows for the sample container 40 to be filled by the urine collected in the receiver 10 . The sample container 40 is pushed against the retractable plug 24 and a spring 60 is activated to allow for the plug 24 to open and urine begins to fill into the sample container 40 . When pressure is released, the spring 60 will bias the retractable plug 24 into the original closed position and urine will stop flowing from the receiver 10 .
[0064] The sample container 40 is then removed by twisting it in the opposite direction as to insertion.
[0065] As shown in FIG. 9 , the sample container 40 comprises a cross member 62 which breaks the surface tension of the sample and this prevents any drops from being left behind once the sample container 40 is removed from the receiver 10 .
[0066] Numerous other embodiments of the invention are possible, for example where the receiver is to be used purely for voiding the bladder in instances where a lavatory is not available, the receiver may be connected to a larger container.
|
A receiver for urine whether for taking sample or disposing thereof, includes an open-topped of saddle shape which approximates the configuration of thighs, labia or other convenient zone.
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BACKGROUND OF THE INVENTION
Essentially, the present invention comprises an improvement over or carrying forward of the invention set forth in applicant's prior U.S. Pat. No. 4,009,741, dated Mar. 1, 1977. Details of the improvements of the present invention over said prior patent are set forth hereinbelow:
The prior patent primarily comprises sets of opposed saws spaced transversely along parallel arbors respectively disposed above and below a path along which cants are moved to and beyond said sets of blades for purposes of simultaneously sawing said cants into a plurality of boards or other similar wood products and the edges of the boards also were formed selectively to provide plurality of different configurations, such as shiplap, tongue and groove, overlapping siding, and the like. Opposite surfaces or faces of the boards that were otherwise produced by by the machine actually were sawed faces and as such, contained saw marks and the like, as distinguished from planed finished surfaces.
Planed surfaces can be produced by certain types of saw blades having radially disposed planing members, either of an interrupted or continuous edge, and operable upon one or opposite faces of a saw blade. Illustrative of prior devices of this type in which the blades comprise both sawing and planing characteristics are prior U.S. Pat. No. 3,730,038 to Farb, dated May 1, 1973, U.S. Pat. No. 3,700,016 to Strobel, dated Oct. 24, 1972, and Canadian Pat. No. 964,557 to Weye, dated Mar. 18, 1975.
If blades of such prior patents are operated in pairs in the manner illustrated in applicant's prior U.S. Pat. No. 4,009,741, it has been found that particularly on the opposite faces of the product lumber either ridges or grooves usually are formed due to the inability of the planing or saw blades operating precisely in a common plane. Usually there is at least a minor offset so that a longitudinal groove or ridge is formed midway of said opposite faces of the product. As a result, it is necessary to pass such opposite faces through a planing machine. Further, in the event rounded corners are desired on the completed pieces, still further planing operations are necessary to form such rounded corners. Therefore, at present, it is common practice to form completed dimensional lumber, such as 2×4's, 2×6's, 2×8's and the like, by sawing the same from a cant and then planing the opposite faces and opposite edges as separate operations in a planing mill.
The purpose of the present invention is to eliminate the need for additional planing operations and form completely finished dimensional lumber items by a single pass through a sawing and planing machine, such as that of the present invenetion which is an improvement over applicant's aforementioned prior U.S. Pat. No. 4,009,741, details of which are set forth below:
SUMMARY OF THE INVENTION
It is common practice in the manufacture of saw blades to form the cutting teeth so that they are wider at the outer edge than at the inner edge, primarily to form clearance for the blades and prevent overheating from friction. Examples of blades of this type are shown in prior U.S. Pat. Nos. 505,154 to Bowles, dated Sept. 15, 1893, and 3,362,446 to Potomak, dated Jan. 9, 1968. The Bowles patent incidentally comprises both a saw and planer but nevertheless the outer ends of the cutting members are wider at the tips than at the portions closer to the center of the blade. Blades of this type in particular, if used in applicant's prior woodworking machine distinctly produce longidutinal ridges or grooves along the opposite faces of a lumber product. In order to prevent this however, it has been found by the applicant that if planing blades alone are used on the saw discs by attaching the same to one edge of an inwardly extending notch having at least one straight edge and have the tip of the planing blade extend at least slightly beyond the periphery of the saw disc, there is no need to utilize sharpened saw teeth in addition to the planing blades. Further, and more importantly, however, the applicant has found that by tapering carbide strips comprising the planing members of the saw and wherein the outer ends of the carbide strips are narrower than the inner ends thereof, a highly desirable planing of the opposite faces of dimensional lumber can be formed when such blades are incorporated in the machine of applicant's prior aforementioned patent. Moreover, it has further been found that if the opposite sides of the narrower outer end of the planing members of the saw blades are rendered slightly convex or rounded to a limited extent, there is no tendency for the blades to form lines or ridges in the opposite faces of dimensional lumber products, even when limited amounts of offset between cooperating blades exists.
Still further, it has been found that if the outer faces of the carbide planing strips are made at least slightly concave, the outer edges thereof comprise planing edges which are less than 90° in cross-section, and therefore facilitate the planing operation of the planing strips, together with the outer ends thereof which extend beyond the periphery of the base disc of the blade, to serve as saw teeth.
The only prior art of which applicant is aware in which a circular saw blade is narrower at the periphery than at the central portion of the disc is shown in prior U.S. Pat. No. 3,229,736 to Hallock, dated Jan. 18, 1966, the purpose of which is not clearly understood, but in any event, the narrowing of the blade adjacent the periphery is offset or nullified by the fact that the cutting teeth have a width which is even greater than the thickness of the central portion of the blade. In addition, the rounding of the outer ends of radial blades in a planing saw is illustrated in prior U.S. Pat. No. 3,380,497 to La Velle, dated Apr. 30, 1968. However, there is no longitudinal taper shown in the planer teeth, and furthermore, the length of said members is almost negligible with respect to the diameter of the overall saw blade.
The improved features of applicant's invention are set forth in detail hereinafter and in which further objectives are also set forth in addition to those enumerated hereinabove.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary, somewhat diagrammatic side elevation illustrating the basic principles of the invention in which a pair of combination sawing and planing blades are positioned in operative relationship to cooperate and form a single cut or kerf in a cant of wood.
FIG. 2 is an enlarged fragmentary sectional view, showing details of the invention as illustrated along the line 2--2 of FIG. 1.
FIG. 3 is a side view of a combination sawing and planing blade embodying the principles of the present invention.
FIG. 4 is a fragmentary view of one of the combination sawing and planing members as seen on the line 4--4 and being illustrated on a larger scale than employed in FIG. 3.
FIG. 5 is a fragmentary, enlarged sectional view, seen on the line 5--5 of FIG. 4.
FIG. 6 is an enlarged fragmentary sectional view, as seen on the line 6--6 of FIG. 4.
FIG. 7 is a fragmentary sectional view, illustrating the relationship of opposed cutting and planing members, especially illustrating in phantom examples of misalignment of the blades such as can be tolerated but produce satisfactory results in accordance with the principles of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is illustrated therein, fragmentarily, and somewhat diagrammatically, those portions of a woodworking machine which are necessary to show the principles of the present invention. For a more elaborate illustration of such a machine, reference is made to applicant's prior U.S. Pat. No. 4,009,741.
In FIG. 1, there is shown a cant 10 which may be of any reasonable cross-section in size and usually rough cut at a saw mill or the like. The cant, for example, may be 10"×12", or any other conventional or appropriate size, such as commonly used for the purpose of forming finished dimensional lumber therefrom, such as those which are used for beams, studs, and the like, many different sizes of which are required in the building industry. Common sizes, for example, are 2×4's, 2×6's, 2×8's, 4×4's, etc. For example, a commercial 2×4 actually is only 11/2"×31/2", and similar reductions in size proportionately exist in other dimensional lumber items of which examples are given above. By way of further example, and solely for illustrative purposes, by using applicant's combination saw and planing blades, a rough cut cant actually 33/4"×83/4" can be converted into five (5) finished 2×4's of actually commercial size 11/2"×31/2", solely as a result of one passage through the machine. In addition, and most importantly, no lines or ridges occur on either of the opposite side faces and the corners also are rounded as is normally either required or customary in commercial dimensional lumber presently marketed.
As illustrated in FIG. 1, the machine includes a pair of parallel arbors 12 and 14 which may be either of the cantilever type, as illustrated in applicant's aforementioned prior U.S. Pat. No. 4,009,741 or the arbors may be supported at opposite ends. The arbors 12 and 14 respectively are mounted above and below the path of feed for the cant 10, said path being designated by the direction arrow 16 in FIG. 1. Further with respect to a perpendicular axis to the path of feed, the arbors 12 and 14 are offset longitudinally a limited distance in order that the peripheries of the blades of the upper and lower saws 18 and 20 will not interfere with each other and it will be seen from the phantom circular path of the saws 18 and 20 that they overlap a more or less central longitudinal line parallel to the feed path, as shown in FIG. 1, whereby a kerf extending completely through the cant 10 will be formed by the cooperating saws 18 and 20. Further, the machine includes a plurality of supporting and feed rolls 22, and though not shown, additional pressure rolls engage the upper surface of cant 10 in opposition to the supporting and feed rolls 22 in the manner clearly shown in said aforementioned prior U.S. Pat. No. 4,009,741.
Referring to FIG. 2, which is a section view on the line 2--2 of FIG. 1, the relationship of a plurality of pairs of saws 18 and 20 are shown and it will be seen that the axes 24 and 26 respectively form the upper and lower borders of the figure. It is clearly shown that the blades 18 and 20 are commonly mounted respectively on the arbors 12 and 14 and are secured on the arbors with additional, relatively wide cutters or chipping blades 28 and 30, the entire assembly of saws and cutters or chipping blades being clamped upon the respective arbors 12 and 14 by appropriate nuts 32, which cooperate with shoulders 34 on the arbors 12 and 14, it being understood that said arbors are of the cantilever type in this particular illustration, but such arrangement is not restrictive since opposite ends of the arbors may be supported by suitable bearings, not shown, if desired. As is clear from FIG. 1, the cants 10 are supported upon a plurality of rollers 22 which underlie the same, the uppermost surfaces of the rollers defining a path of movement as symbolized by the line which includes the direction arrow 16 shown in FIG. 1.
Attention is now directed to FIG. 3 in which a saw 36 is shown which, for example, has six radial fingers 38, whereas the blades 18 and 20 in FIG. 1 only have four fingers. In accordance with the present invention, however, the saws are not restricted to any specific number of fingers and any appropriate number may be employed. The saws 18 and 20, as well as the saw 36, preferably are formed from high carbon steel of uniform thickness and provided with a central hole 40 and also preferably a keyway 42. For example, the saws may initially comprise a disc of high carbon steel and by suitable grinding or sawing, the configuration of the saws 18, 20 and 36 may be formed in any suitable manner so as to provide an equal number of similar notches 44, as shown in FIG. 3, it being understood that corresponding notches of that type are also formed in the saws 18 and 20 of FIG. 1. Preferably, one edge 46 of each notch 44 is straight and of appreciable length and said edges may either be radial with respect to the axis of arbor hole 40 or the same may be more or less tangential to side 48 of the arbor hole 40 so as to provide a positive rake, or if desired, the edges 46 may be tangential to side 50 of arbor hole 40, whereby a somewhat negative rake is afforded.
The straight edges 46 of each of the fingers 38 fixedly support carbide cutting strips 52, which preferably are of substantially uniform thickness but, as shown in FIG. 4, are slightly tapered, and the important feature is that the inner end 54 is wider than the tip end 56. The taper preferably is substantially uniform and gradual, and by way of practical example of a size that has been successfully used, where the saw 36 has a thickness of 0.1875 inches, plus or minus, depending on the diameter of the blade, and a wider inner end of the strip 52 is 0.25 inches, while the narrower tip end is 0.21 inches. These dimensions are to be considered illustrative rather than restrictive but at least the proportion of the dimensions is preferably. As seen particularly from FIG. 3, the strips 52 are nearly half the radial distance from the center of the arbor hole 40, whereas in FIG. 1, the strips are substantially half the radial distance from the tip of the strips to the axis of the arbors 12 and 14.
From FIGS. 5 and 6, it will be seen that the strips 52 are wider than the thickness of the radial fingers 38, and preferably, the strips 52 project equal amounts from opposite surfaces of the fingers 38. However, it is within the purview of the invention that, if desired, one edge of the strip 52 may be coincident with one surface of the finger 38, while the opposite edge projects a predetermined distance beyond the opposite face or surface of the fingers 38, it being understood however that alternate strips will project respectively from opposite surfaces of the fingers 38 under such circumstances. In any event, however, the strips will be tapered between the opposite ends thereof substantially in the proportions described above.
To facilitate the planing ability of the strips 52, it is seen particularly from FIGS. 5 and 6 that the outer faces 58 of the strips 52 are concave and the opposite side surfaces thereof slope inwardly in the order of 5° to 7° and are either flat or slightly concave, and thereby produce planing edges 60 on the strips, which in cross-section, are less than 90° . Also, another important feature of the present invention is that the terminal ends 62 of the tips 56 of strips 52 have the opposite sides contracted, such as by being curved, and preferably in a convex manner, inwardly toward each other to provide a cutting edge 62, which preferably is normal or perpendicular to the plane of the saw 36. Especially from FIG. 7, it will be seen that the width of the strip 52 immediately adjacent the tip end 56 has a dimension a while the terminal end 62 has a lesser dimension b. By way of further example, the dimension b is substantially of the order between one-half and three-fourths of that of dimension a.
The purpose of having the outer end 56 of the strip curve inwardly to form the cutting end 62 is that when the saws are operating, it is not possible for the actual corners, for example, of the cutting ends 62 to finally engage the opposite faces of the finished dimensional lumber item 64, and therefore no line or ridge is formed upon such surfaces as usually is the case where the terminal ends of planing blades or saws have no relieved areas and instead have parallel opposite surfaces at the terminal ends.
To illustrate the advantage of the foregoing arrangement, attention is directed to FIG. 7 in which it will be seen that the terminal end of the strip 52 on one blade is shown in full lines relative to the terminal end 52 on a cooperating blade which is not only illustrated in preferred form in full lines, but in addition, several phantom line illustrations of the second tip end are shown, and in all of these it will be seen that the other edges of the cutting edges are narrower or closer together than the remaining portions of the strips 52, so that even though there is a limited amount of misalignment of the cooperating saws on the arbors, there is still no reasonable possibility of forming objectionable markings of any kind, including grooves, lines, or ridges which usually are found on the opposite faces of dimensional lumber when conventional planing blades are used in conjunction with each other.
It also will be noted from both FIGS. 1 and 3 that the tip ends 62, which actually function in sawing capacities, project at least a short distance beyond the outermost ends of the fingers 38 to facilite their functioning in sawing capacity.
Further for purposes of producing dimensional lumber which is finished in all respects by means of a single passage through the machine comprising the present invention, attention is directed to FIG. 2 in which cross-sectional views of completely finished dimensional lumber items 64 are shown which have rounded corners 66. These are formed by means of the relatively wide cutters or chipping blades 28 and 30, which have terminal, preferable carbide, chipping blades 68 formed thereon in which the ends have concave configurations for purposes of planing the corners of the conventional lumber items to form the desired rounded edges thereon as now is quite common in the commercial production of dimensional lumber items, such as 2×4's, 2×6's, etc.
From the foregoing, therefore, it will be seen that the present invention is capable of producing, by means of one passage of a cant through the machine, a plurality of similar completely finished conventional lumber items, which meet all of the current specifications for such items otherwise made by planing all four surfaces as independent operations and frequently required to be done on different machines, whereas by using the present invention, a single machine is capable of producing completely finished dimensional lumber items, meeting all the requirements and specifications currently observed by present producers of lumber, and particularly conserving power due to the process requiring only a single passage through the machine. By way of specific example as shown in FIG. 2, assume that the original cant was rough sawed and is 33/4" thick by 83/4" wide, a total of five (5) completely finished 2×4's are produced simultaneously as a result of having said cant make a single pass through the machine. By using cooperating blades of suitable diameter, finished dimensional lumber items as small, for example, as 2×2's and on up to 2×12's or more may be produced in the machine illustrated and claimed herein and conceivably even conventional lumber of larger sizes are capable of being produced, depending upon the diameters of the saws, chipping blades and the like.
The foregoing description illustrates preferred embodiments of the invention. However, concepts employed may, based upon such description, be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly, as well as in the specific forms shown herein.
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A woodworking machine to form finished dimensional lumber from cants by a single pass of the cants through the machine and comprising compression and feed rollers above and below a longitudinal path and parallel longitudinally offset arbors respectively are mounted above and below the path upon which spaced saw blades are mounted with opposed blades in common planes and of diameters adequate to form complete cuts through a cant during a single pass, the arbors also supporting between the blades additional cutters to plane the edges of the dimensional lumber and form rounded edges thereon. The blades comprise combination saw and planer blades in which a disc has evenly spaced notches forming fingers each having a straight edge upon which tapered carbide cutting strips are mounted, the wider ends being innermost and the opposite sides of the narrower ends being rounded to permit the opposite edges of the strips to serve as planing blades capable of producing smooth faces on the lumber free of markings or ridges while the additional cutters form planed edges between the opposite faces and rounded edges at all corners of the lumber.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Pursuant to U.S.C. § 120, this application is a continuation-in-part of U.S. Utility patent application Ser. No. 11/481,077, filed Jul. 5, 2006, which claims priority to U.S. Provisional Application Ser. No. 60/698,442, filed Jul. 12, 2005; pursuant to U.S.C. § 119(e), this application claims priority to U.S. Provisional Application Ser. No. 60/908,383, filed Mar. 27, 2007, and U.S. Provisional Application Ser. No. 60/908,666, filed Mar. 28, 2007; and pursuant to U.S.C. § 120, and U.S.C. § 363, this application is also a continuation-in-part of International Application No. PCT/US2007/070892, filed Jun. 11, 2007. The contents of the prior applications are incorporated herein by reference in their entirety.
BACKGROUND
[0002] The disclosure relates to wireless energy transfer. Wireless energy transfer may for example, be useful in such applications as providing power to autonomous electrical or electronic devices.
[0003] Radiative modes of omni-directional antennas (which work very well for information transfer) are not suitable for such energy transfer, because a vast majority of energy is wasted into free space. Directed radiation modes, using lasers or highly-directional antennas, can be efficiently used for energy transfer, even for long distances (transfer distance L TRANS >>L DEV , where L DEV is the characteristic size of the device and/or the source), but require existence of an uninterruptible line-of-sight and a complicated tracking system in the case of mobile objects. Some transfer schemes rely on induction, but are typically restricted to very close-range (L TRANS <<L DEV ) or low power (˜mW) energy transfers.
[0004] The rapid development of autonomous electronics of recent years (e.g. laptops, cell-phones, house-hold robots, that all typically rely on chemical energy storage) has led to an increased need for wireless energy transfer.
SUMMARY
[0005] The inventors have realized that resonant objects with coupled resonant modes having localized evanescent field patterns may be used for non-radiative wireless energy transfer. Resonant objects tend to couple, while interacting weakly with other off-resonant environmental objects. Typically, using the techniques described below, as the coupling increases, so does the transfer efficiency. In some embodiments, using the below techniques, the energy-transfer rate can be larger than the energy-loss rate. Accordingly, efficient wireless energy-exchange can be achieved between the resonant objects, while suffering only modest transfer and dissipation of energy into other off-resonant objects. The nearly-omnidirectional but stationary (non-lossy) nature of the near field makes this mechanism suitable for mobile wireless receivers. Various embodiments therefore have a variety of possible applications including for example, placing a source (e.g. one connected to the wired electricity network) on the ceiling of a factory room, while devices (robots, vehicles, computers, or similar) are roaming freely within the room. Other applications include power supplies for electric-engine buses and/or hybrid cars and medical implantable devices.
[0006] In some embodiments, resonant modes are so-called magnetic resonances, for which most of the energy surrounding the resonant objects is stored in the magnetic field; i.e. there is very little electric field outside of the resonant objects. Since most everyday materials (including animals, plants and humans) are non-magnetic, their interaction with magnetic fields is minimal. This is important both for safety and also to reduce interaction with the extraneous environmental objects.
[0007] In one aspect, an apparatus is disclosed for use in wireless energy transfer, which includes a first resonator structure configured to transfer energy with a second resonator structure over a distance D greater than a characteristic size L 2 of the second resonator structure. In some embodiments, D is also greater than one or more of: a characteristic size L 1 of the first resonator structure, a characteristic thickness T 1 of the first resonator structure, and a characteristic width W 1 of the first resonator structure. The energy transfer is mediated by evanescent-tail coupling of a resonant field of the first resonator structure and a resonant field of the second resonator structure. The apparatus may include any of the following features alone or in combination.
[0008] In some embodiments, the first resonator structure is configured to transfer energy to the second resonator structure. In some embodiments, the first resonator structure is configured to receive energy from the second resonator structure. In some embodiments, the apparatus includes the second resonator structure.
[0009] In some embodiments, the first resonator structure has a resonant angular frequency ω 1 , a Q-factor Q 1 , and a resonance width Γ 1 , the second resonator structure has a resonant angular frequency ω 2 , a Q-factor Q 2 , and a resonance width Γ 2 , and the energy transfer has a rate κ. In some embodiments, the absolute value of the difference of the angular frequencies ω 1 and ω 2 is smaller than the broader of the resonant widths Γ 1 and Γ 2 .
[0010] In some embodiments Q 1 >100 and Q 2 >100, Q 1 >300 and Q 2 >300, Q 1 >500 and Q 2 >500, or Q 1 >1000 and Q 2 >1000. In some embodiments, Q 1 >100 or Q 2 >100, Q 1 >300 or Q 2 >300, Q 1 >500 or Q 2 >500, or Q 1 >1000 or Q 2 >1000.
[0011] In some embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
>
0.5
,
κ
Γ
1
Γ
2
>
1
,
κ
Γ
1
Γ
2
>
2
,
or
κ
Γ
1
Γ
2
>
5.
[0000] In some such embodiments, D/L 2 may be as large as 2, as large as 3, as large as 5, as large as 7, or as large as 10.
[0012] In some embodiments, Q 1 >1000 and Q 2 >1000, and the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
>
10
,
κ
Γ
1
Γ
2
>
25
,
or
κ
Γ
1
Γ
2
>
40.
[0000] In some such embodiments, D/L 2 may be as large as 2, as large as 3, as large as 5, as large as 7, as large as 10.
[0013] In some embodiments, Q κ =ω/2κ is less than about 50, less than about 200, less than about 500, or less than about 1000. In some such embodiments, D/L 2 is as large as 2, as large as 3, as large as 5, as large as 7, or as large as 10.
[0014] In some embodiments, the quantity κ/√{square root over (Γ 1 Γ 2 )} is maximized at an angular frequency {tilde over (ω)} with a frequency width {tilde over (Γ)} around the maximum, and
[0015] the absolute value of the difference of the angular frequencies ω 1 and {tilde over (ω)} is smaller than the width {tilde over (Γ)}, and
[0016] the absolute value of the difference of the angular frequencies ω 2 and {tilde over (ω)} is smaller than the width {tilde over (Γ)}.
[0017] In some embodiments, the energy transfer operates with an efficiency η work greater than about 1%, greater than about 10%, greater than about 30%, greater than about 50%, or greater than about 80%.
[0018] In some embodiments, the energy transfer operates with a radiation loss η rad less that about 10%. In some such embodiments the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
0.1
.
[0019] In some embodiments, the energy transfer operates with a radiation loss η rad less that about 1%. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
1.
[0020] In some embodiments, in the presence of a human at distance of more than 3 cm from the surface of either resonant object, the energy transfer operates with a loss to the human η h of less than about 1%. In some such embodiments the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
1.
[0021] In some embodiments, in the presence of a human at distance of more than 10 cm from the surface of either resonant object, the energy transfer operates with a loss to the human η h of less than about 0.2%. In some such embodiments the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
1.
[0022] In some embodiments, during operation, a device coupled to the first or second resonator structure with a coupling rate Γ work receives a usable power P work from the resonator structure.
[0023] In some embodiments, P work is greater than about 0.01 Watt, greater than about 0.1 Watt, greater than about 1 Watt, or greater than about 10 Watt.
[0024] In some embodiments, if the device is coupled to the first resonator, then ½≦[(Γ work /Γ 1 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦2, or ¼≦[(Γ work /Γ 1 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦4, or ⅛≦[(Γ work /Γ 1 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦8, and, if the device is coupled to the second resonator, then ½≦[(Γ work /Γ 2 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦2, or ¼≦[(Γ work /Γ 2 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦4, or ⅛≦[(Γ work /Γ 2 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦8.
[0025] In some embodiments, the device includes an electrical or electronic device. In some embodiments, the device includes a robot (e.g. a conventional robot or a nano-robot). In some embodiments, the device includes a mobile electronic device (e.g. a telephone, or a cell-phone, or a computer, or a laptop computer, or a personal digital assistant (PDA)). In some embodiments, the device includes an electronic device that receives information wirelessly (e.g. a wireless keyboard, or a wireless mouse, or a wireless computer screen, or a wireless television screen). In some embodiments, the device includes a medical device configured to be implanted in a patient (e.g. an artificial organ, or implant configured to deliver medicine). In some embodiments, the device includes a sensor. In some embodiments, the device includes a vehicle (e.g. a transportation vehicle, or an autonomous vehicle).
[0026] In some embodiments, the apparatus further includes the device.
[0027] In some embodiments, during operation, a power supply coupled to the first or second resonator structure with a coupling rate Γ supply drives the resonator structure at a frequency f and supplies power P total . In some embodiments, the absolute value of the difference of the angular frequencies ω=2πf and ω 1 is smaller than the resonant width Γ 1 , and the absolute value of the difference of the angular frequencies ω=2πf and ω 2 is smaller than the resonant width Γ 2 . In some embodiments, f is about the optimum efficiency frequency.
[0028] In some embodiments, if the power supply is coupled to the first resonator, then ½≦[(Γ supply /Γ 1 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦2, or ¼≦[(Γ supply /Γ 1 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦4, or ⅛≦[(Γ supply /Γ 1 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦8, and, if the power supply is coupled to the second resonator, then ¼≦[(Γ supply /Γ 2 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦2, or ¼≦[(Γ supply /Γ 2 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦4, or ⅛≦[(Γ supply /Γ 2 ) 2 −1]/(κ/√{square root over (Γ 1 Γ 2 )}) 2 ≦8.
[0029] In some embodiments, the apparatus further includes the power source.
[0030] In some embodiments, the resonant fields are electromagnetic. In some embodiments, f is about 50 GHz or less, about 1 GHz or less, about 100 MHz or less, about 10 MHz or less, about 1 MHz or less, about 100 KHz or less, or about 10 kHz or less. In some embodiments, f is about 50 GHz or greater, about 1 GHz or greater, about 100 MHz or greater, about 10 MHz or greater, about 1 MHz or greater, about 100 kHz or greater, or about 10 kHz or greater. In some embodiments, f is within one of the frequency bands specially assigned for industrial, scientific and medical (ISM) equipment.
[0031] In some embodiments, the resonant fields are primarily magnetic in the area outside of the resonant objects. In some such embodiments, the ratio of the average electric field energy to average magnetic filed energy at a distance D p from the closest resonant object is less than 0.01, or less than 0.1. In some embodiments, L R is the characteristic size of the closest resonant object and D p /L R is less than 1.5, 3, 5, 7, or 10.
[0032] In some embodiments, the resonant fields are acoustic. In some embodiments, one or more of the resonant fields include a whispering gallery mode of one of the resonant structures.
[0033] In some embodiments, one of the first and second resonator structures includes a self resonant coil of conducting wire, conducting Litz wire, or conducting ribbon. In some embodiments, both of the first and second resonator structures include self resonant coils of conducting wire, conducting Litz wire, or conducting ribbon. In some embodiments, both of the first and second resonator structures include self resonant coils of conducting wire or conducting Litz wire or conducting ribbon, and Q 1 >300 and Q 2 >300.
[0034] In some embodiments, one or more of the self resonant conductive wire coils include a wire of length l and cross section radius a wound into a helical coil of radius r, height h and number of turns N. In some embodiments, N=√{square root over (l 2 −h 2 )}/2πr.
[0035] In some embodiments, for each resonant structure r is about 30 cm, h is about 20 cm, a is about 3 mm and N is about 5.25, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some embodiments, f is about 10.6 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
40
,
κ
Γ
1
Γ
2
≥
15
,
or
κ
Γ
1
Γ
2
≥
5
,
or
κ
Γ
1
Γ
2
≥
1.
[0000] In some such embodiments D/L R is as large as about 2, 3, 5, or 8.
[0036] In some embodiments, for each resonant structure r is about 30 cm, h is about 20 cm, a is about 1 cm and N is about 4, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some embodiments, f is about 13.4 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
70
,
κ
Γ
1
Γ
2
≥
19
,
or
κ
Γ
1
Γ
2
≥
8
,
or
κ
Γ
1
Γ
2
≥
3.
[0000] In some such embodiments D/L R is as large as about 3, 5, 7, or 10.
[0037] In some embodiments, for each resonant structure r is about 10 cm, h is about 3 cm, a is about 2 mm and N is about 6, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some embodiments, f is about 21.4 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
59
,
κ
Γ
1
Γ
2
≥
15
,
or
κ
Γ
1
Γ
2
≥
6
,
or
κ
Γ
1
Γ
2
≥
2.
[0000] In some such embodiments D/L R is as large as about 3, 5, 7, or 10.
[0038] In some embodiments, one of the first and second resonator structures includes a capacitively loaded loop or coil of conducting wire, conducting Litz wire, or conducting ribbon. In some embodiments, both of the first and second resonator structures include capacitively loaded loops or coils of conducting wire, conducting Litz wire, or conducting ribbon. In some embodiments, both of the first and second resonator structures include capacitively loaded loops or coils of conducting wire or conducting Litz wire or conducting ribbon, and Q 1 >300 and Q 2 >300.
[0039] In some embodiments, the characteristic size L R of the resonator structure receiving energy from the other resonator structure is less than about 1 cm and the width of the conducting wire or Litz wire or ribbon of said object is less than about 1 mm, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some embodiments, f is about 380 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
14.9
,
κ
Γ
1
Γ
2
≥
3.2
,
κ
Γ
1
Γ
2
≥
1.2
,
or
κ
Γ
1
Γ
2
≥
0.4
.
[0000] In some such embodiments, D/L R is as large as about 3, about 5, about 7, or about 10.
[0040] In some embodiments, the characteristic size of the resonator structure receiving energy from the other resonator structure L R is less than about 10 cm and the width of the conducting wire or Litz wire or ribbon of said object is less than about 1 cm, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some embodiments, f is about 43 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
15.9
,
κ
Γ
1
Γ
2
≥
4.3
,
κ
Γ
1
Γ
2
≥
1.8
,
or
κ
Γ
1
Γ
2
≥
0.7
.
[0000] In some such embodiments, D/L R is as large as about 3, about 5, about 7, or about 10.
[0041] In some embodiments, the characteristic size L R of the resonator structure receiving energy from the other resonator structure is less than about 30 cm and the width of the conducting wire or Litz wire or ribbon of said object is less than about 5 cm, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some such embodiments, f is about 9 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
67.4
,
κ
Γ
1
Γ
2
≥
17.8
,
κ
Γ
1
Γ
2
≥
7.1
,
or
κ
Γ
1
Γ
2
≥
2.7
.
[0000] In some such embodiments, D/L R is as large as about 3, about 5, about 7, or about 10.
[0042] In some embodiments, the characteristic size of the resonator structure receiving energy from the other resonator structure L R is less than about 30 cm and the width of the conducting wire or Litz wire or ribbon of said object is less than about 5 mm, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some embodiments, f is about 17 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
6.3
,
κ
Γ
1
Γ
2
≥
1.3
,
κ
Γ
1
Γ
2
≥
0.5
.
,
or
κ
Γ
1
Γ
2
≥
0.2
.
[0000] In some such embodiments, D/L R is as large as about 3, about 5, about 7, or about 10.
[0043] In some embodiments, the characteristic size L R of the resonator structure receiving energy from the other resonator structure is less than about 1 m, and the width of the conducting wire or Litz wire or ribbon of said object is less than about 1 cm, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some embodiments, f is about 5 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
6.8
,
κ
Γ
1
Γ
2
≥
1.4
,
κ
Γ
1
Γ
2
≥
0.5
,
κ
Γ
1
Γ
2
≥
0.2
.
[0000] In some such embodiments, D/L R is as large as about 3, about 5, about 7, or about 10.
[0044] In some embodiments, during operation, one of the resonator structures receives a usable power P w from the other resonator structure, an electrical current I s flows in the resonator structure which is transferring energy to the other resonant structure, and the ratio
[0000]
I
s
P
w
[0000] is less than about 5 Amps/√{square root over (Watts)} or less than about 2 Amps/√{square root over (Watts)}. In some embodiments, during operation, one of the resonator structures receives a usable power P w from the other resonator structure, a voltage difference V s appears across the capacitive element of the first resonator structure, and the ratio
[0000]
V
s
P
w
[0000] is less than about 2000 Volts/√{square root over (Watts)} or less than about 4000 Volts/√{square root over (Watts)}.
[0045] In some embodiments, one of the first and second resonator structures includes a inductively loaded rod of conducting wire or conducting Litz wire or conducting ribbon. In some embodiments, both of the first and second resonator structures include inductively loaded rods of conducting wire or conducting Litz wire or conducting ribbon. In some embodiments, both of the first and second resonator structures include inductively loaded rods of conducting wire or conducting Litz wire or conducting ribbon, and Q 1 >300 and Q 2 >300.
[0046] In some embodiments, the characteristic size of the resonator structure receiving energy from the other resonator structure L R is less than about 10 cm and the width of the conducting wire or Litz wire or ribbon of said object is less than about 1 cm, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some embodiments, f is about 14 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
32
,
κ
Γ
1
Γ
2
≥
5.8
,
κ
Γ
1
Γ
2
≥
2
,
or
κ
Γ
1
Γ
2
≥
0.6
.
[0000] In some such embodiments, D/L R is as large as about 3, about 5, about 7, or about 10.
[0047] In some embodiments, the characteristic size L R of the resonator structure receiving energy from the other resonator structure is less than about 30 cm and the width of the conducting wire or Litz wire or ribbon of said object is less than about 5 cm, and, during operation, a power source coupled to the first or second resonator structure drives the resonator structure at a frequency f. In some such embodiments, f is about 2.5 MHz. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
105
,
κ
Γ
1
Γ
2
≥
19
,
κ
Γ
1
Γ
2
≥
6.6
,
or
κ
Γ
1
Γ
2
≥
2.2
.
[0000] In some such embodiments, D/L R is as large as about 3, about 5, about 7, or about 10.
[0048] In some embodiments, one of the first and second resonator structures includes a dielectric disk. In some embodiments, both of the first and second resonator structures include dielectric disks. In some embodiments, both of the first and second resonator structures include dielectric disks, and Q 1 >300 and Q 2 >300.
[0049] In some embodiments, the characteristic size of the resonator structure receiving energy from the other resonator structure is L R and the real part of the permittivity of said resonator structure ∈ is less than about 150. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
42.4
,
κ
Γ
1
Γ
2
≥
6.5
,
κ
Γ
1
Γ
2
≥
2.3
,
κ
Γ
1
Γ
2
≥
0.5
.
[0000] In some such embodiments, D/L R is as large as about 3, about 5, about 7, or about 10.
[0050] In some embodiments, the characteristic size of the resonator structure receiving energy from the other resonator structure is L R and the real part of the permittivity of said resonator structure ∈ is less than about 65. In some such embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
≥
30.9
,
κ
Γ
1
Γ
2
≥
2.3
,
or
κ
Γ
1
Γ
2
≥
0.5
.
[0000] In some such embodiments, D/L R is as large as about 3, about 5, about 7.
[0051] In some embodiments, at least one of the first and second resonator structures includes one of: a dielectric material, a metallic material, a metallodielectric object, a plasmonic material, a plasmonodielectric object, a superconducting material.
[0052] In some embodiments, at least one of the resonators has a quality factor greater than about 5000, or greater than about 10000.
[0053] In some embodiments, the apparatus also includes a third resonator structure configured to transfer energy with one or more of the first and second resonator structures,
[0054] where the energy transfer between the third resonator structure and the one or more of the first and second resonator structures is mediated by evanescent-tail coupling of the resonant field of the one or more of the first and second resonator structures and a resonant field of the third resonator structure.
[0055] In some embodiments, the third resonator structure is configured to transfer energy to one or more of the first and second resonator structures.
[0056] In some embodiments, the first resonator structure is configured to receive energy from one or more of the first and second resonator structures.
[0057] In some embodiments, the first resonator structure is configured to receive energy from one of the first and second resonator structures and transfer energy to the other one of the first and second resonator structures.
[0058] Some embodiments include a mechanism for, during operation, maintaining the resonant frequency of one or more of the resonant objects. In some embodiments, the feedback mechanism comprises an oscillator with a fixed frequency and is configured to adjust the resonant frequency of the one or more resonant objects to be about equal to the fixed frequency. In some embodiments, the feedback mechanism is configured to monitor an efficiency of the energy transfer, and adjust the resonant frequency of the one or more resonant objects to maximize the efficiency.
[0059] In another aspect, a method of wireless energy transfer is disclosed, which method includes providing a first resonator structure and transferring energy with a second resonator structure over a distance D greater than a characteristic size L 2 of the second resonator structure. In some embodiments, D is also greater than one or more of: a characteristic size L 1 of the first resonator structure, a characteristic thickness T 1 of the first resonator structure, and a characteristic width W 1 of the first resonator structure. The energy transfer is mediated by evanescent-tail coupling of a resonant field of the first resonator structure and a resonant field of the second resonator structure.
[0060] In some embodiments, the first resonator structure is configured to transfer energy to the second resonator structure. In some embodiments, the first resonator structure is configured to receive energy from the second resonator structure.
[0061] In some embodiments, the first resonator structure has a resonant angular frequency ω 1 , a Q-factor Q 1 , and a resonance width Γ 1 , the second resonator structure has a resonant angular frequency ω 2 , a Q-factor Q 2 , and a resonance width Γ 2 , and the energy transfer has a rate κ. In some embodiments, the absolute value of the difference of the angular frequencies ω 1 and ω 2 is smaller than the broader of the resonant widths Γ 1 and Γ 2 .
[0062] In some embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
>
0.5
,
κ
Γ
1
Γ
2
>
1
,
κ
Γ
1
Γ
2
>
2
,
or
κ
Γ
1
Γ
2
>
5.
[0000] In some such embodiments, D/L 2 may be as large as 2, as large as 3, as large as 5, as large as 7, or as large as 10.
[0063] In another aspect, an apparatus is disclosed for use in wireless information transfer which includes a first resonator structure configured to transfer information by transferring energy with a second resonator structure over a distance D greater than a characteristic size L 2 of the second resonator structure. In some embodiments, D is also greater than one or more of: a characteristic size L 1 of the first resonator structure, a characteristic thickness T 1 of the first resonator structure, and a characteristic width W 1 of the first resonator structure. The energy transfer is mediated by evanescent-tail coupling of a resonant field of the first resonator structure and a resonant field of the second resonator structure.
[0064] In some embodiments, the first resonator structure is configured to transfer energy to the second resonator structure. In some embodiments, the first resonator structure is configured to receive energy from the second resonator structure. In some embodiments the apparatus includes, the second resonator structure.
[0065] In some embodiments, the first resonator structure has a resonant angular frequency ω 1 , a Q-factor Q 1 , and a resonance width Γ 1 , the second resonator structure has a resonant angular frequency ω 2 , a Q-factor Q 2 , and a resonance width Γ 2 , and the energy transfer has a rate Γ. In some embodiments, the absolute value of the difference of the angular frequencies ω 1 and ω 2 is smaller than the broader of the resonant widths Γ 1 and Γ 2 .
[0066] In some embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
>
0.5
,
κ
Γ
1
Γ
2
>
1
,
κ
Γ
1
Γ
2
>
2
,
or
κ
Γ
1
Γ
2
>
5.
[0000] In some such embodiments, DI L 2 may be as large as 2, as large as 3, as large as 5, as large as 7, or as large as 10.
[0067] In another aspect, a method of wireless information transfer is disclosed, which method includes providing a first resonator structure and transferring information by transferring energy with a second resonator structure over a distance D greater than a characteristic size L 2 of the second resonator structure. In some embodiments, D is also greater than one or more of: a characteristic size L 1 of the first resonator structure, a characteristic thickness T 1 of the first resonator structure, and a characteristic width W 1 of the first resonator structure. The energy transfer is mediated by evanescent-tail coupling of a resonant field of the first resonator structure and a resonant field of the second resonator structure.
[0068] In some embodiments, the first resonator structure is configured to transfer energy to the second resonator structure. In some embodiments, the first resonator structure is configured to receive energy from the second resonator structure.
[0069] In some embodiments, the first resonator structure has a resonant angular frequency ω 1 , a Q-factor Q 1 , and a resonance width Γ 1 , the second resonator structure has a resonant angular frequency ω 2 , a Q-factor Q 2 , and a resonance width Γ 2 , and the energy transfer has a rate κ. In some embodiments, the absolute value of the difference of the angular frequencies ω 1 and ω 2 is smaller than the broader of the resonant widths Γ 1 and Γ 2 ′
[0070] In some embodiments, the coupling to loss ratio
[0000]
κ
Γ
1
Γ
2
>
0.5
,
κ
Γ
1
Γ
2
>
1
,
κ
Γ
1
Γ
2
>
2
,
or
κ
Γ
1
Γ
2
>
5.
[0000] In some such embodiments, D/L 2 may be as large as 2, as large as 3, as large as 5, as large as 7, or as large as 10.
[0071] It is to be understood that the characteristic size of an object is equal to the radius of the smallest sphere which can fit around the entire object. The characteristic thickness of an object is, when placed on a flat surface in any arbitrary configuration, the smallest possible height of the highest point of the object above a flat surface. The characteristic width of an object is the radius of the smallest possible circle that the object can pass through while traveling in a straight line. For example, the characteristic width of a cylindrical object is the radius of the cylinder.
[0072] The distance D over which the energy transfer between two resonant objects occurs is the distance between the respective centers of the smallest spheres which can fit around the entirety of each object. However, when considering the distance between a human and a resonant object, the distance is to be measured from the outer surface of the human to the outer surface of the sphere.
[0073] As described in detail below, non-radiative energy transfer refers to energy transfer effected primarily through the localized near field, and, at most, secondarily through the radiative portion of the field.
[0074] It is to be understood that an evanescent tail of a resonant object is the decaying non-radiative portion of a resonant field localized at the object. The decay may take any functional form including, for example, an exponential decay or power law decay.
[0075] The optimum efficiency frequency of a wireless energy transfer system is the frequency at which the figure of merit
[0000]
κ
Γ
1
Γ
2
[0000] is maximized, all other factors held constant.
[0076] The resonant width (Γ) refers to the width of an object's resonance due to object's intrinsic losses (e.g. loss to absorption, radiation, etc.).
[0077] It is to be understood that a Q-factor (Q) is a factor that compares the time constant for decay of an oscillating system's amplitude to its oscillation period. For a given resonator mode with angular frequency ω and resonant width Γ, the Q-factor Q=ω/2Γ.
[0078] The energy transfer rate (κ) refers to the rate of energy transfer from one resonator to another. In the coupled mode description described below it is the coupling constant between the resonators.
[0079] It is to be understood that Q κ =ω/2κ.
[0080] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict with publications, patent applications, patents, and other references mentioned incorporated herein by reference, the present specification, including definitions, will control.
[0081] Various embodiments may include any of the above features, alone or in combination. Other features, objects, and advantages of the disclosure will be apparent from the following detailed description.
[0082] Other features, objects, and advantages of the disclosure will be apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0083] FIG. 1 shows a schematic of a wireless energy transfer scheme.
[0084] FIG. 2 shows an example of a self-resonant conducting-wire coil.
[0085] FIG. 3 shows a wireless energy transfer scheme featuring two self-resonant conducting-wire coils
[0086] FIG. 4 shows an example of a capacitively loaded conducting-wire coil, and illustrates the surrounding field.
[0087] FIG. 5 shows a wireless energy transfer scheme featuring two capacitively loaded conducting-wire coils, and illustrates the surrounding field.
[0088] FIG. 6 shows an example of a resonant dielectric disk, and illustrates the surrounding field.
[0089] FIG. 7 shows a wireless energy transfer scheme featuring two resonant dielectric disks, and illustrates the surrounding field.
[0090] FIGS. 8 a and 8 b show schematics for frequency control mechanisms.
[0091] FIGS. 9 a through 9 c illustrate a wireless energy transfer scheme in the presence of various extraneous objects.
[0092] FIG. 10 illustrates a circuit model for wireless energy transfer.
[0093] FIG. 11 illustrates the efficiency of a wireless energy transfer scheme.
[0094] FIG. 12 illustrates parametric dependences of a wireless energy transfer scheme.
[0095] FIG. 13 plots the parametric dependences of a wireless energy transfer scheme.
[0096] FIG. 14 is a schematic of an experimental system demonstrating wireless energy transfer.
[0097] FIGS. 15-17 . Plot experiment results for the system shown schematically in FIG. 14 .
DETAILED DESCRIPTION
[0098] FIG. 1 shows a schematic that generally describes one embodiment of the invention, in which energy is transferred wirelessly between two resonant objects.
[0099] Referring to FIG. 1 , energy is transferred, over a distance D, between a resonant source object having a characteristic size L 1 and a resonant device object of characteristic size L 2 . Both objects are resonant objects. The source object is connected to a power supply (not shown), and the device object is connected to a power consuming device (e.g. a load resistor, not shown). Energy is provided by the power supply to the source object, transferred wirelessly and non-radiatively from the source object to the device object, and consumed by the power consuming device. The wireless non-radiative energy transfer is performed using the field (e.g. the electromagnetic field or acoustic field) of the system of two resonant objects. For simplicity, in the following we will assume that field is the electromagnetic field.
[0100] It is to be understood that while two resonant objects are shown in the embodiment of FIG. 1 , and in many of the examples below, other embodiments may feature 3 or more resonant objects. For example, in some embodiments a single source object can transfer energy to multiple device objects. In some embodiments energy may be transferred from a first device to a second, and then from the second device to the third, and so forth.
[0101] Initially, we present a theoretical framework for understanding non-radiative wireless energy transfer. Note however that it is to be understood that the scope of the invention is not bound by theory.
[0102] Coupled Mode Theory
[0103] An appropriate analytical framework for modeling the resonant energy-exchange between two resonant objects 1 and 2 is that of “coupled-mode theory” (CMT). The field of the system of two resonant objects 1 and 2 is approximated by F(r,t)≈a 1 (t)F 1 (r)+a 2 (t)F 2 (r), where F 1,2 (r) are the eigenmodes of 1 and 2 alone, normalized to unity energy, and the field amplitudes a 1,2 (t) are defined so that |a 1,2 (t)| 2 is equal to the energy stored inside the objects 1 and 2 respectively. Then, the field amplitudes can be shown to satisfy, to lowest order:
[0000]
a
1
t
=
-
(
ω
1
-
Γ
1
)
a
1
+
κ
a
2
a
2
t
=
-
(
ω
2
-
Γ
2
)
a
2
+
κ
a
1
,
(
1
)
[0000] where ω 1,2 are the individual angular eigenfrequencies of the eigenmodes, Γ 1,2 are the resonance widths due to the objects' intrinsic (absorption, radiation etc.) losses, and κ is the coupling coefficient. Eqs. (1) show that at exact resonance (ω 1 =ω 2 and Γ 1 =Γ 2 ), the eigenmodes of the combined system are split by 2κ; the energy exchange between the two objects takes place in time ˜π/2Γ and is nearly perfect, apart for losses, which are minimal when the coupling rate is much faster than all loss rates (κ>>Γ 1,2 ). The coupling to loss ratio Γ/√{square root over (Γ 1 Γ 2 )} serves as a figure-of-merit in evaluating a system used for wireless energy-transfer, along with the distance over which this ratio can be achieved. The regime κ/√{square root over (Γ 1 Γ 2 )}>>1 is called “strong-coupling” regime.
[0104] In some embodiments, the energy-transfer application preferably uses resonant modes of high Q=ω/2Γ, corresponding to low (i.e. slow) intrinsic-loss rates Γ. This condition may be satisfied where the coupling is implemented using, not the lossy radiative far-field, but the evanescent (non-lossy) stationary near-field.
[0105] To implement an energy-transfer scheme, usually finite objects, namely ones that are topologically surrounded everywhere by air, are more appropriate. Unfortunately, objects of finite extent cannot support electromagnetic states that are exponentially decaying in all directions in air, since, from Maxwell's Equations in free space: {right arrow over (k)} 2 =ω 2 /c 2 where {right arrow over (k)} is the wave vector, ω the angular frequency, and c the speed of light. Because of this, one can show that they cannot support states of infinite Q. However, very long-lived (so-called “high-Q”) states can be found, whose tails display the needed exponential or exponential-like decay away from the resonant object over long enough distances before they turn oscillatory (radiative). The limiting surface, where this change in the field behavior happens, is called the “radiation caustic”, and, for the wireless energy-transfer scheme to be based on the near field rather than the far/radiation field, the distance between the coupled objects must be such that one lies within the radiation caustic of the other.
[0106] Furthermore, in some embodiments, small Q κ =ω/2κ corresponding to strong (i.e. fast) coupling rate κ is preferred over distances larger than the characteristic sizes of the objects. Therefore, since the extent of the near-field into the area surrounding a finite-sized resonant object is set typically by the wavelength, in some embodiments, this mid-range non-radiative coupling can be achieved using resonant objects of subwavelength size, and thus significantly longer evanescent field-tails. As will be seen in examples later on, such subwavelength resonances can often be accompanied with a high Q, so this will typically be the appropriate choice for the possibly-mobile resonant device-object. Note, though, that in some embodiments, the resonant source-object will be immobile and thus less restricted in its allowed geometry and size, which can be therefore chosen large enough that the near-field extent is not limited by the wavelength. Objects of nearly infinite extent, such as dielectric waveguides, can support guided modes whose evanescent tails are decaying exponentially in the direction away from the object, slowly if tuned close to cutoff, and can have nearly infinite Q.
[0107] In the following, we describe several examples of systems suitable for energy transfer of the type described above. We will demonstrate how to compute the CMT parameters ω 1,2 , Q 1,2 and Q κ described above and how to choose these parameters for particular embodiments in order to produce a desirable figure-of-merit κ/√{square root over (Γ 1 Γ 2 )}=√{square root over (Q 1 Q 2 )}/Q κ . In particular, this figure of merit is typically maximized when ω 1,2 are tuned to a particular angular frequency {tilde over (ω)}, thus, if {tilde over (Γ)} is half the angular-frequency width for which √{square root over (Q 1 Q 2 )}/Q κ is above half its maximum value at {tilde over (ω)}, the angular eigenfrequencies ω 1,2 should typically be tuned to be close to {tilde over (ω)} to within the width {tilde over (Γ)}.
[0108] In addition, as described below, Q 1,2 can sometimes be limited not from intrinsic loss mechanisms but from external perturbations. In those cases, producing a desirable figure-of-merit translates to reducing Q κ (i.e. increasing the coupling). Accordingly we will demonstrate how, for particular embodiments, to reduce Q κ .
[0109] Self-Resonant Conducting Coils
[0110] In some embodiments, one or more of the resonant objects are self-resonant conducting coils. Referring to FIG. 2 , a conducting wire of length l and cross-sectional radius a is wound into a helical coil of radius r and height h (namely with N=√{square root over (l 2 −h 2 )}/2πr number of turns), surrounded by air. As described below, the wire has distributed inductance and distributed capacitance, and therefore it supports a resonant mode of angular frequency ω. The nature of the resonance lies in the periodic exchange of energy from the electric field within the capacitance of the coil, due to the charge distribution ρ(x) across it, to the magnetic field in free space, due to the current distribution j(x) in the wire. In particular, the charge conservation equation ∇·j=iωρ implies that: (i) this periodic exchange is accompanied by a π/2 phase-shift between the current and the charge density profiles, namely the energy U contained in the coil is at certain points in time completely due to the current and at other points in time completely due to the charge, and (ii) if ρ l (x) and I(x) are respectively the linear charge and current densities in the wire, where x runs along the wire,
[0000]
q
o
=
1
2
∫
x
ρ
l
(
x
)
[0000] is the maximum amount of positive charge accumulated in one side of the coil (where an equal amount of negative charge always also accumulates in the other side to make the system neutral) and I 0 =max{|I(x)|} is the maximum positive value of the linear current distribution, then I 0 =ωq 0 . Then, one can define an effective total inductance L and an effective total capacitance C of the coil through the amount of energy U inside its resonant mode:
[0000]
U
≡
1
2
I
o
2
L
⇒
L
=
μ
o
4
π
I
o
2
∫
∫
x
x
′
j
(
x
)
·
j
(
x
′
)
x
-
x
′
,
(
2
)
U
≡
1
2
q
o
2
1
C
⇒
1
C
=
1
4
π
ɛ
o
q
o
2
x
x
′
ρ
(
x
)
·
ρ
(
x
′
)
x
-
x
′
,
(
3
)
[0000] where μ 0 and ∈ 0 are the magnetic permeability and electric permittivity of free space. With these definitions, the resonant angular frequency and the effective impedance are given by the common formulas ω=1/√{square root over (LC)} and Z=√{square root over (L/C)} respectively.
[0111] Losses in this resonant system consist of ohmic (material absorption) loss inside the wire and radiative loss into free space. One can again define a total absorption resistance R abs from the amount of power absorbed inside the wire and a total radiation resistance R rad from the amount of power radiated due to electric- and magnetic-dipole radiation:
[0000]
P
abs
≡
1
2
I
o
2
R
abs
⇒
R
abs
≈
ζ
c
l
2
π
a
·
I
rms
2
I
o
2
(
4
)
P
rad
≡
1
2
I
o
2
R
rad
≈
ζ
o
6
π
[
(
ω
p
c
)
2
+
(
ω
m
c
)
4
]
,
(
5
)
[0000] where c=1/√{square root over (μ 0 ∈ 0 )} and ζ 0 =√{square root over (μ 0 /∈ 0 )} are the light velocity and light impedance in free space, the impedance ζ c is ζ c =1/σδ=√{square root over (μ 0 ω/2σ)} with σ the conductivity of the conductor and δ the skin depth at the frequency
[0000]
ω
,
I
rms
2
=
1
l
∫
x
I
(
x
)
2
,
p
=
∫
xr
ρ
l
(
x
)
[0000] is the electric-dipole moment of the coil and
[0000]
m
=
1
2
∫
xr
×
j
(
x
)
[0000] is the magnetic-dipole moment of the coil. For the radiation resistance formula Eq. (5), the assumption of operation in the quasi-static regime (h,r<<λ=2πc/ω) has been used, which is the desired regime of a subwavelength resonance. With these definitions, the absorption and radiation quality factors of the resonance are given by Q abs =Z/R abs and Q rad =Z/R rad respectively.
[0112] From Eq. (2)-(5) it follows that to determine the resonance parameters one simply needs to know the current distribution j in the resonant coil. Solving Maxwell's equations to rigorously find the current distribution of the resonant electromagnetic eigenmode of a conducting-wire coil is more involved than, for example, of a standard LC circuit, and we can find no exact solutions in the literature for coils of finite length, making an exact solution difficult. One could in principle write down an elaborate transmission-line-like model, and solve it by brute force. We instead present a model that is (as described below) in good agreement (˜5%) with experiment. Observing that the finite extent of the conductor forming each coil imposes the boundary condition that the current has to be zero at the ends of the coil, since no current can leave the wire, we assume that the resonant mode of each coil is well approximated by a sinusoidal current profile along the length of the conducting wire. We shall be interested in the lowest mode, so if we denote by x the coordinate along the conductor, such that it runs from −l/2 to +l/2, then the current amplitude profile would have the form I(x)=I 0 cos(πx/l), where we have assumed that the current does not vary significantly along the wire circumference for a particular x, a valid assumption provided a <<r. It immediately follows from the continuity equation for charge that the linear charge density profile should be of the form π l (x)=π 0 sin(πx/l), and thus
[0000]
q
0
=
∫
0
1
/
2
x
ρ
0
sin
(
π
x
/
l
)
=
ρ
0
l
/
π
.
[0000] Using these sinusoidal profiles we find the so-called “self-inductance” L s and “self-capacitance” C s of the coil by computing numerically the integrals Eq. (2) and (3); the associated frequency and effective impedance are ω s and Z s respectively. The “self-resistances” R s are given analytically by Eq. (4) and (5) using
[0000]
I
rms
2
=
1
l
∫
-
l
/
2
l
/
2
x
I
o
cos
(
π
x
/
l
)
2
=
1
2
I
o
2
,
p
=
q
o
(
2
π
h
)
2
+
(
4
N
cos
(
π
N
)
(
4
N
2
-
1
)
π
r
)
2
and
m
=
I
o
(
2
π
N
π
r
2
)
2
+
(
cos
(
π
N
)
(
12
N
2
-
1
)
-
sin
(
π
N
)
π
N
(
4
N
2
-
1
)
(
16
N
4
-
8
N
2
+
1
)
π
hr
)
2
,
[0000] and therefore the associated Q s factors may be calculated.
[0113] The results for two particular embodiments of resonant coils with subwavelength modes of λ s /r≧70 (i.e. those highly suitable for near-field coupling and well within the quasi-static limit) are presented in Table 1. Numerical results are shown for the wavelength and absorption, radiation and total loss rates, for the two different cases of subwavelength-coil resonant modes. Note that, for conducting material, copper (σ=5.998·10̂−7S/m) was used. It can be seen that expected quality factors at microwave frequencies are Q s abs ≧1000 and Q s rad ≧5000.
[0000]
TABLE 1
single coil
λ s /r
f (MHz)
Q s rad
Q s abs
Q s = ω s /2Γ s
r = 30 cm, h = 20 cm,
74.7
13.39
4164
8170
2758
a = 1 cm, N = 4
r = 10 cm, h = 3 cm,
140
21.38
43919
3968
3639
a = 2 mm, N = 6
[0114] Referring to FIG. 3 , in some embodiments, energy is transferred between two self-resonant conducting-wire coils. The electric and magnetic fields are used to couple the different resonant conducting-wire coils at a distance D between their centers. Usually, the electric coupling highly dominates over the magnetic coupling in the system under consideration for coils with h>>2r and, oppositely, the magnetic coupling highly dominates over the electric coupling for coils with h<<2r. Defining the charge and current distributions of two coils 1,2 respectively as ρ 1,2 (x) and j 1,2 (x), total charges and peak currents respectively as q 1,2 and I 1,2 , and capacitances and inductances respectively as C 1,2 and L 1,2 , which are the analogs of ρ(x), j(x), q 0 , I 0 , C and L for the single-coil case and are therefore well defined, we can define their mutual capacitance and inductance through the total energy:
[0000]
U
≡
U
1
+
U
2
+
1
2
(
q
1
*
q
2
+
q
2
*
q
1
)
/
M
C
+
1
2
(
I
1
*
I
2
+
I
2
*
I
1
)
M
L
⇒
1
/
M
C
=
1
4
π
ɛ
o
q
1
q
2
∫
∫
x
x
′
ρ
1
(
x
)
·
ρ
2
(
x
′
)
x
-
x
′
u
,
M
L
=
μ
o
4
π
I
1
I
2
∫
∫
x
x
′
j
1
(
x
)
·
j
2
(
x
′
)
x
-
x
′
u
,
where
U
1
=
1
2
q
1
2
/
C
1
=
1
2
I
1
2
L
1
,
U
2
=
1
2
q
2
2
/
C
2
=
1
2
I
2
2
L
2
(
6
)
[0000] and the retardation factor of u=exp(iω|x−x′|/c) inside the integral can been ignored in the quasi-static regime D<<λ of interest, where each coil is within the near field of the other. With this definition, the coupling coefficient is given by κ=ω√{square root over (C 1 C 2 )}/2M C +ωM L /2√{square root over (L 1 L 2 )} Q κ −1 =(M C /√{square root over (C 1 C 2 )}) −1 +(√{square root over (L 1 L 2 )}/M L ) −1 .
[0115] Therefore, to calculate the coupling rate between two self-resonant coils, again the current profiles are needed and, by using again the assumed sinusoidal current profiles, we compute numerically from Eq. (6) the mutual capacitance M C,s and inductance M L,s between two self-resonant coils at a distance D between their centers, and thus Q κ,s is also determined.
[0000]
TABLE 2
pair of coils
D/r
Q = ω/2Γ
Q κ = ω/2κ
κ/Γ
r = 30 cm, h = 20 cm,
3
2758
38.9
70.9
a = 1 cm, N = 4
5
2758
139.4
19.8
λ/r ≈ 75
7
2758
333.0
8.3
Q s abs ≈ 8170, Q s rad ≈ 4164
10
2758
818.9
3.4
r = 10 cm, h = 3 cm,
3
3639
61.4
59.3
a = 2 mm, N = 6
5
3639
232.5
15.7
λ/r ≈ 140
7
3639
587.5
6.2
Q s abs ≈ 3968, Q s rad ≈ 43919
10
3639
1580
2.3
[0116] Referring to Table 2, relevant parameters are shown for exemplary embodiments featuring pairs or identical self resonant coils. Numerical results are presented for the average wavelength and loss rates of the two normal modes (individual values not shown), and also the coupling rate and figure-of-merit as a function of the coupling distance D, for the two cases of modes presented in Table 1. It can be seen that for medium distances D/r=10-3 the expected coupling-to-loss ratios are in the range κ/Γ˜2-70.
Capacitively-Loaded Conducting Loops or Coils
[0117] In some embodiments, one or more of the resonant objects are capacitively-loaded conducting loops or coils. Referring to FIG. 4 a helical coil with N turns of conducting wire, as described above, is connected to a pair of conducting parallel plates of area A spaced by distance d via a dielectric material of relative permittivity ∈, and everything is surrounded by air (as shown, N=1 and h=0). The plates have a capacitance C p =∈ 0 ∈A/d, which is added to the distributed capacitance of the coil and thus modifies its resonance. Note however, that the presence of the loading capacitor modifies significantly the current distribution inside the wire and therefore the total effective inductance L and total effective capacitance C of the coil are different respectively from L s and C s , which are calculated for a self-resonant coil of the same geometry using a sinusoidal current profile. Since some charge is accumulated at the plates of the external loading capacitor, the charge distribution ρ inside the wire is reduced, so C<C s , and thus, from the charge conservation equation, the current distribution j flattens out, so L>L s . The resonant frequency for this system is ω=1/√{square root over (L(C+C p ))}<ω s =1/√{square root over (L s C s )}, and I(x)→I 0 cos(πx/l) C→C s ω→ω s , as C p →0.
[0118] In general, the desired CMT parameters can be found for this system, but again a very complicated solution of Maxwell's Equations is required. Instead, we will analyze only a special case, where a reasonable guess for the current distribution can be made. When C p >>C s >C, then ω≈1/√{square root over (LC p )}<<ω s and Z≈√{square root over (L/C p )}<<Z s , while all the charge is on the plates of the loading capacitor and thus the current distribution is constant along the wire. This allows us now to compute numerically L from Eq. (2). In the case h=0 and N integer, the integral in Eq. (2) can actually be computed analytically, giving the formula L=μ 0 r[ln(8r/a)−2]N 2 . Explicit analytical formulas are again available for R from Eq. (4) and (5), since I rms =I 0 , |p|≈0 |m|=I 0 Nπr 2 (namely only the magnetic-dipole term is contributing to radiation), so we can determine also Q abs =ωL/R abs and Q rad =ωL/R rad . At the end of the calculations, the validity of the assumption of constant current profile is confirmed by checking that indeed the condition C p >>C s ω<<ω s is satisfied. To satisfy this condition, one could use a large external capacitance, however, this would usually shift the operational frequency lower than the optimal frequency, which we will determine shortly; instead, in typical embodiments, one often prefers coils with very small self-capacitance C s to begin with, which usually holds, for the types of coils under consideration, when N=1, so that the self-capacitance comes from the charge distribution across the single turn, which is almost always very small, or when N>1 and h>>2Na, so that the dominant self-capacitance comes from the charge distribution across adjacent turns, which is small if the separation between adjacent turns is large.
[0119] The external loading capacitance C p provides the freedom to tune the resonant frequency (for example by tuning A or d). Then, for the particular simple case h=0, for which we have analytical formulas, the total Q=ωL/(R abs +R rad ) becomes highest at the optimal frequency
[0000]
ω
~
=
[
c
4
π
ɛ
o
2
σ
·
1
aNr
3
]
2
/
7
,
(
7
)
[0000] reaching the value
[0000]
Q
~
=
6
7
π
(
2
π
2
η
o
σ
a
2
N
2
r
)
3
/
7
·
[
ln
(
8
r
a
)
-
2
]
.
(
8
)
[0000] At lower frequencies it is dominated by ohmic loss and at higher frequencies by radiation. Note, however, that the formulas above are accurate as long as {tilde over (ω)}<<ω s and, as explained above, this holds almost always when N=1, and is usually less accurate when N>1, since h=0 usually implies a large self-capacitance. A coil with large h can be used, if the self-capacitance needs to be reduced compared to the external capacitance, but then the formulas for L and {tilde over (ω)}, {tilde over (Q)} are again less accurate. Similar qualitative behavior is expected, but a more complicated theoretical model is needed for making quantitative predictions in that case.
[0120] The results of the above analysis for two embodiments of subwavelength modes of λ/r≧70 (namely highly suitable for near-field coupling and well within the quasi-static limit) of coils with N=1 and h=0 at the optimal frequency Eq. (7) are presented in Table 3. To confirm the validity of constant-current assumption and the resulting analytical formulas, mode-solving calculations were also performed using another completely independent method: computational 3D finite-element frequency-domain (FEFD) simulations (which solve Maxwell's Equations in frequency domain exactly apart for spatial discretization) were conducted, in which the boundaries of the conductor were modeled using a complex impedance ζ c =√{square root over (μ 0 ω/2σ)} boundary condition, valid as long as ζ c /ζ 0 <<1 (<10 −5 for copper in the microwave). Table 3 shows Numerical FEFD (and in parentheses analytical) results for the wavelength and absorption, radiation and total loss rates, for two different cases of subwavelength-loop resonant modes. Note that for conducting material copper (σ=5.998·10 7 S/m) was used. (The specific parameters of the plot in FIG. 4 are highlighted with bold in the table.) The two methods (analytical and computational) are in very good agreement and show that, in some embodiments, the optimal frequency is in the low-MHz microwave range and the expected quality factors are Q abs ≧1000 and Q rad ≧10000.
[0000]
TABLE 3
single coil
λ/r
f (MHz)
Q rad
Q abs
Q = ω/2Γ
r = 30 cm , a = 2 cm
111.4 (112.4)
8.976 (8.897)
29546 (30512)
4886 (5117)
4193 (4381)
∈ = 10, A = 138 cm
2
, d = 4 mm
r = 10 cm, a = 2 mm
69.7 (70.4)
43.04 (42.61)
10702 (10727)
1545 (1604)
1350 (1395)
∈ = 10, A = 3.14 cm 2 , d = 1 mm
[0121] Referring to FIG. 5 , in some embodiments, energy is transferred between two capacitively-loaded coils. For the rate of energy transfer between two capacitively-loaded coils 1 and 2 at distance D between their centers, the mutual inductance M L can be evaluated numerically from Eq. (6) by using constant current distributions in the case ω<<ω s . In the case h=0, the coupling is only magnetic and again we have an analytical formula, which, in the quasi-static limit r<<D<<λ and for the relative orientation shown in FIG. 4 , is M L ≈πμ 0 /2·(r 1 r 2 ) 2 N 1 N 2 /D 3 ,which means that Q κ ∝(D/√{square root over (r 1 r 2 )}) 3 is independent of the frequency ω and the number of turns N 1 , N 2 . Consequently, the resultant coupling figure-of-merit of interest is
[0000]
κ
Γ
1
Γ
2
=
Q
1
Q
2
Q
k
≈
(
r
1
r
2
D
)
3
·
π
2
η
0
r
1
r
2
λ
·
N
1
N
2
∏
j
=
1
,
2
(
π
η
0
λσ
·
r
j
a
j
N
j
+
8
3
π
5
η
0
(
r
j
λ
)
4
N
j
2
)
1
/
2
,
(
9
)
[0000] which again is more accurate for N 1 =N 2 =1.
[0122] From Eq. (9) it can be seen that the optimal frequency {tilde over (ω)}, where the figure-of-merit is maximized to the value
[0000]
(
Q
1
Q
2
/
Q
κ
)
~
,
[0000] is that where √{square root over (Q 1 Q 2 )} is maximized, since Q κ does not depend on frequency (at least for the distances D<<λ of interest for which the quasi-static approximation is still valid). Therefore, the optimal frequency is independent of the distance D between the two coils and lies between the two frequencies where the single-coil Q 1 and Q 2 peak. For same coils, it is given by Eq. (7) and then the figure-of-merit Eq. (9) becomes
[0000]
(
κ
Γ
)
~
=
Q
~
Q
κ
≈
(
r
D
)
2
·
3
7
(
2
π
2
η
0
σα
2
N
2
r
)
3
/
7
.
(
10
)
[0000] Typically, one should tune the capacitively-loaded conducting loops or coils, so that their angular eigenfrequencies are close to {tilde over (ω)} within {tilde over (Γ)}, which is half the angular frequency width for which
[0000]
Q
1
Q
2
/
Q
κ
>
(
Q
1
Q
2
/
Q
κ
)
~
/
2.
[0123] Referring to Table 4, numerical FEFD and, in parentheses, analytical results based on the above are shown for two systems each composed of a matched pair of the loaded coils described in Table 3. The average wavelength and loss rates are shown along with the coupling rate and coupling to loss ratio figure-of-merit κ/Γ as a function of the coupling distance D, for the two cases. Note that the average numerical Γ rad shown are again slightly different from the single-loop value of FIG. 3 , analytical results for Γ rad are not shown but the single-loop value is used. (The specific parameters corresponding to the plot in FIG. 5 are highlighted with bold in the table.) Again we chose N=1 to make the constant-current assumption a good one and computed M L numerically from Eq. (6). Indeed the accuracy can be confirmed by their agreement with the computational FEFD mode-solver simulations, which give κ through the frequency splitting (=2κ) of the two normal modes of the combined system. The results show that for medium distances D/r=10-3 the expected coupling-to-loss ratios are in the range κ/Γ˜0.5-50.
[0000]
TABLE 4
pair of coils
D/r
Q rad
Q = ω/2Γ
Q κ = ω/2κ
κ/Γ
r = 30 cm, a = 2 cm
3
30729
4216
62.6 (63.7)
67.4 (68.7)
ε = 10, A = 138 cm
2
, d = 4 mm
5
29577
4194
235 (248)
17.8 (17.6)
λ/r ≈ 112
7
29128
4185
589 (646)
7.1 (6.8)
Q abs ≈ 4886
10
28833
4177
1539 (1828)
2.7 (2.4)
r = 10 cm, a = 2 mm
3
10955
1355
85.4 (91.3)
15.9 (15.3)
ε = 10, A = 3.14 cm 2 , d = 1 mm
5
10740
1351
313 (356)
4.32 (3.92)
λ/r ≈ 70
7
10759
1351
754 (925)
1.79 (1.51)
Q abs ≈ 1546
10
10756
1351
1895 (2617)
0.71 (0.53)
[0124] Optimization of √{square root over (Q 1 Q 2 )}/Q κ
[0125] In some embodiments, the results above can be used to increase or optimize the performance of a wireless energy transfer system which employs capacitively-loaded coils. For example, the scaling of Eq. (10) with the different system parameters one sees that to maximize the system figure-of-merit κ/Γ one can, for example:
[0126] Decrease the resistivity of the conducting material. This can be achieved, for example, by using good conductors (such as copper or silver) and/or lowering the temperature. At very low temperatures one could use also superconducting materials to achieve extremely good performance.
[0127] Increase the wire radius a. In typical embodiments, this action is limited by physical size considerations. The purpose of this action is mainly to reduce the resistive losses in the wire by increasing the cross-sectional area through which the electric current is flowing, so one could alternatively use also a Litz wire or a ribbon instead of a circular wire.
[0128] For fixed desired distance D of energy transfer, increase the radius of the loop r. In typical embodiments, this action is limited by physical size considerations.
[0129] For fixed desired distance vs. loop-size ratio D/r, decrease the radius of the loop r. In typical embodiments, this action is limited by physical size considerations.
[0130] Increase the number of turns N. (Even though Eq. (10) is expected to be less accurate for N>1, qualitatively it still provides a good indication that we expect an improvement in the coupling-to-loss ratio with increased N.) In typical embodiments, this action is limited by physical size and possible voltage considerations, as will be discussed in following sections.
[0131] Adjust the alignment and orientation between the two coils. The figure-of-merit is optimized when both cylindrical coils have exactly the same axis of cylindrical symmetry (namely they are “facing” each other). In some embodiments, particular mutual coil angles and orientations that lead to zero mutual inductance (such as the orientation where the axes of the two coils are perpendicular) should be avoided.
[0132] Finally, note that the height of the coil h is another available design parameter, which has an impact to the performance similar to that of its radius r, and thus the design rules are similar.
[0133] The above analysis technique can be used to design systems with desired parameters. For example, as listed below, the above described techniques can be used to determine the cross sectional radius a of the wire which one should use when designing as system two same single-turn loops with a given radius in order to achieve a specific performance in terms of κ/Γ at a given D/r between them, when the material is copper (σ=5.998·10 7 S/m):
D/r=5, κ/Γ≧10, r=30 cm a≧9 mm D/r=5, κ/Γ≧10, r=5 cm a≧3.7 mm D/r=5, κ/Γ≧20, r=30 cm a≧20 mm D/r=5, κ/Γ≧20, r=5 cm a≧8.3 mm D/r=10, κ/Γ≧1, r=30 cm a≧7 mm D/r=10, κ/Γ≧1, r=5 cm a≧2.8 mm D/r=10, κ/Γ≧3, r=30 cm a≧25 mm D/r=10, κ/Γ≧3, r=5 cm a≧10 mm
[0142] Similar analysis can be done for the case of two dissimilar loops. For example, in some embodiments, the device under consideration is very specific (e.g. a laptop or a cell phone), so the dimensions of the device object (r d , h d , a d , N d ) are very restricted. However, in some such embodiments, the restrictions on the source object (r s , h s , a s , N s ) are much less, since the source can, for example, be placed under the floor or on the ceiling. In such cases, the desired distance is often well defined, based on the application (e.g. D˜1 m for charging a laptop on a table wirelessly from the floor). Listed below are examples (simplified to the case N s =N d =1 and h s =h d =0) of how one can vary the dimensions of the source object to achieve the desired system performance in terms of κ/√{square root over (Γ s Γ d )}, when the material is again copper (σ=5.998·10 7 S/m):
D=1.5 m, κ/√{square root over (Γ s Γ d )}≧15, r d =30 cm, a d =6 mm r s =1.158 m, a s ≧5 mm D=1.5 m, κ/√{square root over (Γ s Γ d )}≧30, r d =30 cm, a d =6 mm r s =1.15 m, a s ≧33 mm D=1.5 m, κ/√{square root over (Γ s Γ d )}≧1, r d =5 cm, a d =4 mm r s =1.119 m, a s ≧7 mm D=1.5 m, κ/√{square root over (Γ s Γ d )}≧2, r d =5 cm, a d =4 mm r s =1.119 m, a s ≧52 mm D=2 m, κ/√{square root over (Γ s Γ d )}≧10, r d =30 cm, a d =6 mm r s =1.518 m, a s ≧7 mm D=2 m, κ/√{square root over (Γ s Γ d )}≧20, r d =30 cm, a d =6 mm r s =1.514 m, a s ≧50 mm D=2 m, κ/√{square root over (Γ s Γ d )}≧0.5,r d =5 cm, a d =4 mm r s =1.491 m, a s ≧5 mm D=2 m, κ/√{square root over (Γ s Γ d )}≧1, r d =5 cm, a d =4 mm r s =1.491 m, a s ≧36 mm
[0151] Optimization of Q κ
[0152] As will be described below, in some embodiments the quality factor Q of the resonant objects is limited from external perturbations and thus varying the coil parameters cannot lead to improvement in Q. In such cases, one may opt to increase the coupling to loss ratio figure-of-merit by decreasing Q κ (i.e. increasing the coupling). The coupling does not depend on the frequency and the number of turns. Therefore, the remaining degrees of freedom are:
[0153] Increase the wire radii a 1 and a 2 . In typical embodiments, this action is limited by physical size considerations.
[0154] For fixed desired distance D of energy transfer, increase the radii of the coils r 1 and r 2 . In typical embodiments, this action is limited by physical size considerations.
[0155] For fixed desired distance vs. coil-sizes ratio D/√{square root over (r 1 r 2 )}, only the weak (logarithmic) dependence of the inductance remains, which suggests that one should decrease the radii of the coils r 1 and r 2 . In typical embodiments, this action is limited by physical size considerations.
[0156] Adjust the alignment and orientation between the two coils. In typical embodiments, the coupling is optimized when both cylindrical coils have exactly the same axis of cylindrical symmetry (namely they are “facing” each other). Particular mutual coil angles and orientations that lead to zero mutual inductance (such as the orientation where the axes of the two coils are perpendicular) should obviously be avoided.
[0157] Finally, note that the heights of the coils h 1 and h 2 are other available design parameters, which have an impact to the coupling similar to that of their radii r 1 and r 2 , and thus the design rules are similar.
[0158] Further practical considerations apart from efficiency, e.g. physical size limitations, will be discussed in detail below.
[0159] It is also important to appreciate the difference between the above described resonant-coupling inductive scheme and the well-known non-resonant inductive scheme for energy transfer. Using CMT it is easy to show that, keeping the geometry and the energy stored at the source fixed, the resonant inductive mechanism allows for ˜Q 2 (˜10 6 ) times more power delivered for work at the device than the traditional non-resonant mechanism. This is why only close-range contact-less medium-power (˜W) transfer is possible with the latter, while with resonance either close-range but large-power (˜kW) transfer is allowed or, as currently proposed, if one also ensures operation in the strongly-coupled regime, medium-range and medium-power transfer is possible. Capacitively-loaded conducting loops are currently used as resonant antennas (for example in cell phones), but those operate in the far-field regime with D/r>>1, r/λ˜1, and the radiation Q's are intentionally designed to be small to make the antenna efficient, so they are not appropriate for energy transfer.
[0160] Inductively-Loaded Conducting Rods
[0161] A straight conducting rod of length 2h and cross-sectional radius a has distributed capacitance and distributed inductance, and therefore it supports a resonant mode of angular frequency ω. Using the same procedure as in the case of self-resonant coils, one can define an effective total inductance L and an effective total capacitance C of the rod through formulas (2) and (3). With these definitions, the resonant angular frequency and the effective impedance are given again by the common formulas ω=1/√{square root over (LC)} and Z=√{square root over (L/C)} respectively. To calculate the total inductance and capacitance, one can assume again a sinusoidal current profile along the length of the conducting wire. When interested in the lowest mode, if we denote by x the coordinate along the conductor, such that it runs from −h to +h, then the current amplitude profile would have the form I(x)=I 0 cos(πx/2h), since it has to be zero at the open ends of the rod. This is the well-known half-wavelength electric dipole resonant mode.
[0162] In some embodiments, one or more of the resonant objects are inductively-loaded conducting rods. A straight conducting rod of length 2h and cross-sectional radius a, as in the previous paragraph, is cut into two equal pieces of length h, which are connected via a coil wrapped around a magnetic material of relative permeability μ, and everything is surrounded by air. The coil has an inductance L c , which is added to the distributed inductance of the rod and thus modifies its resonance. Note however, that the presence of the center-loading inductor modifies significantly the current distribution inside the wire and therefore the total effective inductance L and total effective capacitance C of the rod are different respectively from L s and C s , which are calculated for a self-resonant rod of the same total length using a sinusoidal current profile, as in the previous paragraph. Since some current is running inside the coil of the external loading inductor, the current distribution j inside the rod is reduced, so L<L s , and thus, from the charge conservation equation, the linear charge distribution ρ l flattens out towards the center (being positive in one side of the rod and negative in the other side of the rod, changing abruptly through the inductor), so C>C s . The resonant frequency for this system is ω=1/√{square root over ((L+L c )C)}<ω s =1/√{square root over (L s C s )}, and I(x)→I 0 cos(πx/2h) L→L s ω→ω s , as L c →0.
[0163] In general, the desired CMT parameters can be found for this system, but again a very complicated solution of Maxwell's Equations is required. Instead, we will analyze only a special case, where a reasonable guess for the current distribution can be made. When L c >>L s >L, then ω≈1/√{square root over (L c C)}<<ω s and Z≈√{square root over (L c /C)}>>Z s , while the current distribution is triangular along the rod (with maximum at the center-loading inductor and zero at the ends) and thus the charge distribution is positive constant on one half of the rod and equally negative constant on the other side of the rod. This allows us now to compute numerically C from Eq. (3). In this case, the integral in Eq. (3) can actually be computed analytically, giving the formula 1/C=1/(π∈ 0 h)[l n(h/a)−1]. Explicit analytical formulas are again available for R from Eq. (4) and (5), since I rms =I 0 , |p|=q 0 h and |m|=0 (namely only the electric-dipole term is contributing to radiation), so we can determine also Q abs =1/ωCR abs and Q rad =1/ωCR rad . At the end of the calculations, the validity of the assumption of triangular current profile is confirmed by checking that indeed the condition L C >>L s ω<<ω s is satisfied. This condition is relatively easily satisfied, since typically a conducting rod has very small self-inductance L s to begin with.
[0164] Another important loss factor in this case is the resistive loss inside the coil of the external loading inductor L c and it depends on the particular design of the inductor. In some embodiments, the inductor is made of a Brooks coil, which is the coil geometry which, for fixed wire length, demonstrates the highest inductance and thus quality factor. The Brooks coil geometry has N Bc turns of conducting wire of cross-sectional radius a Bc wrapped around a cylindrically symmetric coil former, which forms a coil with a square cross-section of side r Bc , where the inner side of the square is also at radius r BC (and thus the outer side of the square is at radius 2r Bc ), therefore N Bc ≈(r Bc /2a Bc ). The inductance of the coil is then L c =2.0285μ 0 r Bc N Bc 2 ≈2.0285μ 0 r Bc 5 /8a Bc 4 and its resistance
[0000]
R
c
≈
1
σ
l
Bc
π
a
Bc
2
1
+
μ
0
ωσ
2
(
a
Bc
2
)
2
,
[0000] where the total wire length is l Bc ≈2π(3r Bc /2)N Bc ≈3πr Bc 3 /4a Bc 2 and we have used an approximate square-root law for the transition of the resistance from the dc to the ac limit as the skin depth varies with frequency.
[0165] The external loading inductance L c provides the freedom to tune the resonant frequency. (For example, for a Brooks coil with a fixed size r Bc , the resonant frequency can be reduced by increasing the number of turns N Bc by decreasing the wire cross-sectional radius a Bc . Then the desired resonant angular frequency ω=1/√{square root over (L c C)} is achieved for a Bc ≈(2.0285μ 0 r Bc 5 ω 2 C) 1/4 and the resulting coil quality factor is
[0000]
Q
c
≈
0.169
μ
0
σ
r
Bc
2
ω
/
1
+
ω
2
μ
0
σ
2.0285
μ
0
(
r
Bc
/
4
)
5
C
)
.
[0000] Then, for the particular simple case L c >>L s , for which we have analytical formulas, the total Q=1/ωC(R c +R abs +R rad ) becomes highest at some optimal frequency {tilde over (ω)}, reaching the value {tilde over (Q)}, both determined by the loading-inductor specific design. (For example, for the Brooks-coil procedure described above, at the optimal frequency {tilde over (Q)}≈Q c ≈0.8(μ 0 σ 2 r Bc 3 /C) 1/4 ) At lower frequencies it is dominated by ohmic loss inside the inductor coil and at higher frequencies by radiation. Note, again, that the above formulas are accurate as long as {tilde over (ω)}<<ω s and, as explained above, this is easy to design for by using a large inductance.
[0166] The results of the above analysis for two embodiments, using Brooks coils, of subwavelength modes of λ/h≧200 (namely highly suitable for near-field coupling and well within the quasi-static limit) at the optimal frequency {tilde over (ω)} are presented in Table 5. Table 5 shows in parentheses (for similarity to previous tables) analytical results for the wavelength and absorption, radiation and total loss rates, for two different cases of subwavelength-loop resonant modes. Note that for conducting material copper (σ=5.998·10 7 S/m) was used. The results show that, in some embodiments, the optimal frequency is in the low-MHz microwave range and the expected quality factors are Q abs ≧1000 and Q rad >100000.
[0000]
TABLE 5
single rod
λ/h
f (MHz)
Q rad
Q abs
Q = ω/2Γ
h = 30 cm,
(403.8)
(2.477)
(2.72 * 10 6 )
(7400)
(7380)
a = 2 cm
μ = 1,
r Bc = 2 cm,
a Bc = 0.88 mm,
N Bc = 129
h = 10 cm,
(214.2)
(14.010)
(6.92 * 10 5 )
(3908)
(3886)
a = 2 mm
μ = 1,
r Bc = 5 mm,
a Bc = 0.25 mm,
[0167] In some embodiments, energy is transferred between two inductively-loaded rods. For the rate of energy transfer between two inductively-loaded rods 1 and 2 at distance D between their centers, the mutual capacitance M c can be evaluated numerically from Eq. (6) by using triangular current distributions in the case ω<<ω s . In this case, the coupling is only electric and again we have an analytical formula, which, in the quasi-static limit h<<D<<λ and for the relative orientation such that the two rods are aligned on the same axis, is 1/M C ≈1/2π∈ 0 ·(h 1 h 2 ) 2 /D 3 , which means that Q κ ∝(D/√{square root over (h 1 h 2 )}) 3 is independent of the frequency ω. Consequently, one can get the resultant coupling figure-of-merit of interest
[0000]
κ
Γ
1
Γ
2
=
Q
1
Q
2
Q
κ
.
[0000] It can be seen that the optimal frequency {tilde over (ω)}, where the figure-of-merit is maximized to the value
[0000]
(
Q
1
Q
2
/
Q
κ
)
~
,
[0000] is that where √{square root over (Q 1 Q 2 )} is maximized, since Q κ does not depend on frequency (at least for the distances D<<λ of interest for which the quasi-static approximation is still valid). Therefore, the optimal frequency is independent of the distance D between the two rods and lies between the two frequencies where the single-rod Q 1 and Q 2 peak. Typically, one should tune the inductively-loaded conducting rods, so that their angular eigenfrequencies are close to {tilde over (ω)} within {tilde over (Γ)}, which is half the angular frequency width for which
[0000]
Q
1
Q
2
/
Q
κ
>
(
Q
1
Q
2
/
Q
κ
)
~
/
2.
[0168] Referring to Table 6, in parentheses (for similarity to previous tables) analytical results based on the above are shown for two systems each composed of a matched pair of the loaded rods described in Table 5. The average wavelength and loss rates are shown along with the coupling rate and coupling to loss ratio figure-of-merit κ/Γ as a function of the coupling distance D, for the two cases. Note that for Γ rad the single-rod value is used. Again we chose L c >>L s to make the triangular-current assumption a good one and computed M C numerically from Eq. (6). The results show that for medium distances D/h=10-3 the expected coupling-to-loss ratios are in the range κ/Γ˜0.5-100.
[0000]
TABLE 6
pair of rods
D/h
Q κ = ω/2κ
κ/Γ
h = 30 cm, a = 2 cm
3
(70.3)
(105.0)
μ = 1, r Bc = 2 cm,
5
(389)
(19.0)
a Bc = 0.88 mm, N Bc = 129
7
(1115)
(6.62)
λ/h ≈ 404
10
(3321)
(2.22)
Q ≈ 7380
h = 10 cm, a = 2 mm
3
(120)
(32.4)
μ = 1, r Bc = 5 mm,
5
(664)
(5.85)
a Bc = 0.25 mm, N Bc = 103
7
(1900)
(2.05)
λ/h ≈ 214
10
(5656)
(0.69)
Q ≈ 3886
[0169] Dielectric Disks
[0170] In some embodiments, one or more of the resonant objects are dielectric objects, such as disks. Consider a two dimensional dielectric disk object, as shown in FIG. 6 , of radius r and relative permittivity ∈ surrounded by air that supports high-Q “whispering-gallery” resonant modes. The loss mechanisms for the energy stored inside such a resonant system are radiation into free space and absorption inside the disk material. High-Q rad and long-tailed subwavelength resonances can be achieved when the dielectric permittivity ∈ is large and the azimuthal field variations are slow (namely of small principal number m). Material absorption is related to the material loss tangent: Q abs ˜Re{∈}/Im{∈}. Mode-solving calculations for this type of disk resonances were performed using two independent methods: numerically, 2D finite-difference frequency-domain (FDFD) simulations (which solve Maxwell's Equations in frequency domain exactly apart for spatial discretization) were conducted with a resolution of 30 pts/r; analytically, standard separation of variables (SV) in polar coordinates was used.
[0000] TABLE 7 single disk λ/r Q abs Q rad Q Re{ε} = 20.01 (20.00) 10103 (10075) 1988 (1992) 1661 (1663) 147.7, m = 2 Re{ε} = 9.952 (9.950) 10098 (10087) 9078 (9168) 4780 (4802) 65.6, m = 3
The results for two TE-polarized dielectric-disk subwavelength modes of λ/r≧10 are presented in Table 7. Table 7 shows numerical FDFD (and in parentheses analytical SV) results for the wavelength and absorption, radiation and total loss rates, for two different cases of subwavelength-disk resonant modes. Note that disk-material loss-tangent Im{∈}/Re{∈}=10 −4 was used. (The specific parameters corresponding to the plot in FIG. 6 . are highlighted with bold in the table.) The two methods have excellent agreement and imply that for a properly designed resonant low-loss-dielectric object values of Q rad ≧2000 and Q abs ˜10000 are achievable. Note that for the 3D case the computational complexity would be immensely increased, while the physics would not be significantly different. For example, a spherical object of ∈=147.7 has a whispering gallery mode with m=2, Qrad=13962, and λ/r=17.
[0171] The required values of ∈, shown in Table 7, might at first seem unrealistically large. However, not only are there in the microwave regime (appropriate for approximately meter-range coupling applications) many materials that have both reasonably high enough dielectric constants and low losses (e.g. Titania, Barium tetratitanate, Lithium tantalite etc.), but also ∈ could signify instead the effective index of other known subwavelength surface-wave systems, such as surface modes on surfaces of metallic materials or plasmonic (metal-like, negative-∈) materials or metallo-dielectric photonic crystals or plasmono-dielectric photonic crystals.
[0172] To calculate now the achievable rate of energy transfer between two disks 1 and 2 , as shown in FIG. 7 we place them at distance D between their centers. Numerically, the FDFD mode-solver simulations give K through the frequency splitting (=2κ) of the normal modes of the combined system, which are even and odd superpositions of the initial single-disk modes; analytically, using the expressions for the separation-of-variables eigenfields E1,2(r) CMT gives κ through κ=ω 1 /2·∫d 3 r∈ 2 (r)E 2 *(r)E 1 (r)/∫d 3 r∈(r)|E 1 (r)| 2 where ∈ j (r) and ∈(r) are the dielectric functions that describe only the disk j (minus the constant ∈ 0 background) and the whole space respectively. Then, for medium distances D/r=10-3 and for non-radiative coupling such that D<2r c , where r c =mλ/2π is the radius of the radiation caustic, the two methods agree very well, and we finally find, as shown in Table 8, coupling-to-loss ratios in the range κ/Γ˜1-50. Thus, for the analyzed embodiments, the achieved figure-of-merit values are large enough to be useful for typical applications, as discussed below.
[0000]
TABLE 8
two disks
D/r
Q rad
Q = ω/2Γ
ω/2κ
κ/Γ
Re{ε} = 147.7 ,
3
2478
1989
46.9 (47.5)
42.4 (35.0)
m = 2
5
2411
1946
298.0 (298.0)
6.5 (5.6)
λ/r ≈ 20
7
2196
1804
769.7 (770.2)
2.3 (2.2)
Q abs ≈ 10093
10
2017
1681
1714 (1601)
0.98 (1.04)
Re{ε} = 65.6,
3
7972
4455
144 (140)
30.9 (34.3)
m = 3
5
9240
4824
2242 (2083)
2.2 (2.3)
λ/r ≈ 10
7
9187
4810
7485 (7417)
0.64 (0.65)
Q abs ≈ 10096
[0173] Note that even though particular embodiments are presented and analyzed above as examples of systems that use resonant electromagnetic coupling for wireless energy transfer, those of self-resonant conducting coils, capacitively-loaded resonant conducting coils and resonant dielectric disks, any system that supports an electromagnetic mode with its electromagnetic energy extending much further than its size can be used for transferring energy. For example, there can be many abstract geometries with distributed capacitances and inductances that support the desired kind of resonances. In any one of these geometries, one can choose certain parameters to increase and/or optimize √{square root over (Q 1 Q 2 )}/Q κ or, if the Q's are limited by external factors, to increase and/or optimize for Q κ .
[0174] System Sensitivity to Extraneous Objects
[0175] In general, the overall performance of particular embodiment of the resonance-based wireless energy-transfer scheme depends strongly on the robustness of the resonant objects' resonances. Therefore, it is desirable to analyze the resonant objects' sensitivity to the near presence of random non-resonant extraneous objects. One appropriate analytical model is that of “perturbation theory” (PT), which suggests that in the presence of an extraneous object e the field amplitude a l (t) inside the resonant object 1 satisfies, to first order:
[0000]
a
1
t
=
-
i
(
ω
1
-
i
Γ
1
)
a
1
+
i
(
κ
11
-
e
+
i
Γ
1
-
e
)
a
1
(
11
)
[0000] where again ω 1 is the frequency and Γ 1 the intrinsic (absorption, radiation etc.) loss rate, while κ 11-e is the frequency shift induced onto 1 due to the presence of e and Γ 1-e is the extrinsic due to e (absorption inside e, scattering from e etc.) loss rate. The first-order PT model is valid only for small perturbations. Nevertheless, the parameters κ 11-e , Γ 1-e are well defined, even outside that regime, if a 1 is taken to be the amplitude of the exact perturbed mode. Note also that interference effects between the radiation field of the initial resonant-object mode and the field scattered off the extraneous object can for strong scattering (e.g. off metallic objects) result in total radiation—Γ 1-e 's that are smaller than the initial radiation—Γ 1 (namely Γ 1-e is negative).
[0176] The frequency shift is a problem that can be “fixed” by applying to one or more resonant objects a feedback mechanism that corrects its frequency. For example, referring to FIG. 8 a , in some embodiments each resonant object is provided with an oscillator at fixed frequency and a monitor which determines the frequency of the object. Both the oscillator and the monitor are coupled to a frequency adjuster which can adjust the frequency of the resonant object by, for example, adjusting the geometric properties of the object (e.g. the height of a self-resonant coil, the capacitor plate spacing of a capacitively-loaded loop or coil, the dimensions of the inductor of an inductively-loaded rod, the shape of a dielectric disc, etc.) or changing the position of a non-resonant object in the vicinity of the resonant object. The frequency adjuster determines the difference between the fixed frequency and the object frequency and acts to bring the object frequency into alignment with the fixed frequency. This technique assures that all resonant objects operate at the same fixed frequency, even in the presence of extraneous objects.
[0177] As another example, referring to FIG. 8 b , in some embodiments, during energy transfer from a source object to a device object, the device object provides energy to a load, and an efficiency monitor measures the efficiency of the transfer. A frequency adjuster coupled to the load and the efficiency monitor acts to adjust the frequency of the object to maximize the transfer efficiency.
[0178] In various embodiments, other frequency adjusting schemes may be used which rely on information exchange between the resonant objects. For example, the frequency of a source object can be monitored and transmitted to a device object, which is in turn synched to this frequency using frequency adjusters as described above. In other embodiments the frequency of a single clock may be transmitted to multiple devices, and each device then synched to that frequency.
[0179] Unlike the frequency shift, the extrinsic loss can be detrimental to the functionality of the energy-transfer scheme, because it is difficult to remedy, so the total loss rate Γ 1[e] =Γ 1 +Γ 1-e (and the corresponding figure-of-merit κ [e] /√{square root over (Γ 1[e] Γ 2[e] )}, where κ [e] the perturbed coupling rate) should be quantified. In embodiments using primarily magnetic resonances, the influence of extraneous objects on the resonances is nearly absent. The reason is that, in the quasi-static regime of operation (r<<λ) that we are considering, the near field in the air region surrounding the resonator is predominantly magnetic (e.g. for coils with h<<2r most of the electric field is localized within the self-capacitance of the coil or the externally loading capacitor), therefore extraneous non-conducting objects e that could interact with this field and act as a perturbation to the resonance are those having significant magnetic properties (magnetic permeability Re{μ}>1 or magnetic loss Im{μ}>0). Since almost all every-day non-conducting materials are non-magnetic but just dielectric, they respond to magnetic fields in the same way as free space, and thus will not disturb the resonance of the resonator. Extraneous conducting materials can however lead to some extrinsic losses due to the eddy currents induced on their surface.
[0180] As noted above, an extremely important implication of this fact relates to safety considerations for human beings. Humans are also non-magnetic and can sustain strong magnetic fields without undergoing any risk. A typical example, where magnetic fields B˜1T are safely used on humans, is the Magnetic Resonance Imaging (MRI) technique for medical testing. In contrast, the magnetic near-field required in typical embodiments in order to provide a few Watts of power to devices is only B˜10 −4 T, which is actually comparable to the magnitude of the Earth's magnetic field. Since, as explained above, a strong electric near-field is also not present and the radiation produced from this non-radiative scheme is minimal, it is reasonable to expect that our proposed energy-transfer method should be safe for living organisms.
[0181] One can, for example, estimate the degree to which the resonant system of a capacitively-loaded conducting-wire coil has mostly magnetic energy stored in the space surrounding it. If one ignores the fringing electric field from the capacitor, the electric and magnetic energy densities in the space surrounding the coil come just from the electric and magnetic field produced by the current in the wire; note that in the far field, these two energy densities must be equal, as is always the case for radiative fields. By using the results for the fields produced by a subwavelength (r<<λ) current loop (magnetic dipole) with h=0, we can calculate the ratio of electric to magnetic energy densities, as a function of distance D p from the center of the loop (in the limit r<<D p ) and the angle θ with respect to the loop axis:
[0000]
u
e
(
x
)
u
m
(
x
)
=
ɛ
o
E
(
x
)
2
μ
o
H
(
x
)
2
=
(
1
+
1
x
2
)
sin
2
θ
(
1
x
2
+
1
x
4
)
4
cos
2
θ
+
(
1
-
1
x
2
+
1
x
4
)
sin
2
θ
;
x
=
2
π
D
p
λ
⇒
∯
S
p
u
e
(
x
)
S
∯
S
p
u
m
(
x
)
S
=
1
+
1
x
2
1
+
1
x
2
+
3
x
4
;
x
=
2
π
D
p
λ
,
(
12
)
[0000] where the second line is the ratio of averages over all angles by integrating the electric and magnetic energy densities over the surface of a sphere of radius D p . From Eq. (12) it is obvious that indeed for all angles in the near field (x<<1) the magnetic energy density is dominant, while in the far field (x>>1) they are equal as they should be. Also, the preferred positioning of the loop is such that objects which may interfere with its resonance lie close to its axis (θ=0), where there is no electric field. For example, using the systems described in Table 4, we can estimate from Eq. (12) that for the loop of r=30 cm at a distance D p =10r=3m the ratio of average electric to average magnetic energy density would be ˜12% and at D p =3r=90 cm it would be ˜1%, and for the loop of r=10 cm at a distance D p =10r=1m the ratio would be ˜33% and at D p =3r=30 cm it would be ˜2.5%. At closer distances this ratio is even smaller and thus the energy is predominantly magnetic in the near field, while in the radiative far field, where they are necessarily of the same order (ratio→1), both are very small, because the fields have significantly decayed, as capacitively-loaded coil systems are designed to radiate very little. Therefore, this is the criterion that qualifies this class of resonant system as a magnetic resonant system.
[0182] To provide an estimate of the effect of extraneous objects on the resonance of a capacitively-loaded loop including the capacitor fringing electric field, we use the perturbation theory formula, stated earlier, Γ 1-e abs =ω 1 /4·∫d 3 rIm{∈ e (r)}|E 1 (r)| 2 /U with the computational FEFD results for the field of an example like the one shown in the plot of FIG. 5 and with a rectangular object of dimensions 30 cm×30 cm×1.5 m and permittivity ∈=49+16i (consistent with human muscles) residing between the loops and almost standing on top of one capacitor (˜3 cm away from it) and find Q c-h abs ˜10 5 and for ˜10 cm away Q c-h abs ˜5·10 5 . Thus, for ordinary distances (˜1 m) and placements (not immediately on top of the capacitor) or for most ordinary extraneous objects e of much smaller loss-tangent, we conclude that it is indeed fair to say that Q c-e abs →∞. The only perturbation that is expected to affect these resonances is a close proximity of large metallic structures.
[0183] Self-resonant coils are more sensitive than capacitively-loaded coils, since for the former the electric field extends over a much larger region in space (the entire coil) rather than for the latter (just inside the capacitor). On the other hand, self-resonant coils are simple to make and can withstand much larger voltages than most lumped capacitors.
[0184] In general, different embodiments of resonant systems have different degree of sensitivity to external perturbations, and the resonant system of choice depends on the particular application at hand, and how important matters of sensitivity or safety are for that application. For example, for a medical implantable device (such as a wirelessly powered artificial heart) the electric field extent must be minimized to the highest degree possible to protect the tissue surrounding the device. In such cases where sensitivity to external objects or safety is important, one should design the resonant systems so that the ratio of electric to magnetic energy density u e /u m is reduced or minimized at most of the desired (according to the application) points in the surrounding space.
[0185] In embodiments using resonances that are not primarily magnetic, the influence of extraneous objects may be of concern. For example, for dielectric disks, small, low-index, low-material-loss or far-away stray objects will induce small scattering and absorption. In such cases of small perturbations these extrinsic loss mechanisms can be quantified using respectively the analytical first-order perturbation theory formulas
[0000] Γ 1-e rad =ω 1 ∫d 3 rRE{∈ e ( r )}| E 1 ( r )| 2 /U
[0000] and
[0000] Γ 1-e abs =ω 1 /4 ·∫d 3 rIm{∈ e ( r )}| E 1 ( r )| 2 /U
[0000] where U=½∫d 3 r∈(r)|E 1 (r)|E 1 (r)| 2 is the total resonant electromagnetic energy of the unperturbed mode. As one can see, both of these losses depend on the square of the resonant electric field tails E 1 at the site of the extraneous object. In contrast, the coupling rate from object 1 to another resonant object 2 is, as stated earlier,
[0000] κ=ω 1 /2 ·∫d 3 r∈ 2 ( r ) E 2 *( r )/∫ d 3 r∈ ( r )| E 1 ( r )| 2
[0000] and depends linearly on the field tails E 1 of 1 inside 2 . This difference in scaling gives us confidence that, for, for example, exponentially small field tails, coupling to other resonant objects should be much faster than all extrinsic loss rates (κ>>Γ 1-e ), at least for small perturbations, and thus the energy-transfer scheme is expected to be sturdy for this class of resonant dielectric disks. However, we also want to examine certain possible situations where extraneous objects cause perturbations too strong to analyze using the above first-order perturbation theory approach. For example, we place a dielectric disk c close to another off-resonance object of large Re{∈}, Im{∈} and of same size but different shape (such as a human being h), as shown in FIG. 9 a , and a roughened surface of large extent but of small Re{∈}, Im{∈} (such as a wall w), as shown in FIG. 9 b . For distances D h/w /r=10 −3 between the disk-center and the “human”-center or “wall”, the numerical FDFD simulation results presented in FIGS. 9 a and 9 b suggest that, the disk resonance seems to be fairly robust, since it is not detrimentally disturbed by the presence of extraneous objects, with the exception of the very close proximity of high-loss objects. To examine the influence of large perturbations on an entire energy-transfer system we consider two resonant disks in the close presence of both a “human” and a “wall”. Comparing Table 8 to the table in FIG. 9 c , the numerical FDFD simulations show that the system performance deteriorates from κ/Γ c ˜1-50 to κ[hw]/Γ c[hw] ˜0.5-10 i.e. only by acceptably small amounts.
[0186] Inductively-loaded conducting rods may also be more sensitive than capacitively-loaded coils, since they rely on the electric field to achieve the coupling.
System Efficiency
[0187] In general, another important factor for any energy transfer scheme is the transfer efficiency. Consider again the combined system of a resonant source s and device d in the presence of a set of extraneous objects e. The efficiency of this resonance-based energy-transfer scheme may be determined, when energy is being drained from the device at rate Γ work for use into operational work. The coupled-mode-theory equation for the device field-amplitude is
[0000]
a
d
t
=
-
i
(
ω
-
i
Γ
d
[
e
]
)
a
d
+
i
κ
[
e
]
a
s
-
Γ
work
a
d
,
(
13
)
[0000] where Γ d[e] =Γ d[e] rad +Γ d[e] abs =Γ d[e] rad +(Γ d abs +Γ d-e abs ) is the net perturbed-device loss rate, and similarly we define Γ s[e] for the perturbed-source. Different temporal schemes can be used to extract power from the device (e.g. steady-state continuous-wave drainage, instantaneous drainage at periodic times and so on) and their efficiencies exhibit different dependence on the combined system parameters. For simplicity, we assume steady state, such that the field amplitude inside the source is maintained constant, namely a s (t)=A s e −iωt , so then the field amplitude inside the device is a d (t)=A d e −iωt with A d /A s =iκ [e] /(Γ d[e] +Γ work ). The various time-averaged powers of interest are then: the useful extracted power is P work =2Γ work|A d | 2 , the radiated (including scattered) power is P rad =2Γ s[e] rad |A s | 2 +2Γ d[e] rad |A d | 2 , the power absorbed at the source/device is P s/d =2Γ s/d abs |A s/d | 2 , and at the extraneous objects P e =2Γ s-e abs |A s | 2 +2Γ d-e abs |A d | 2 . From energy conservation, the total time-averaged power entering the system is P total =P work +P rad +P s +P d +P e . Note that the reactive powers, which are usually present in a system and circulate stored energy around it, cancel at resonance (which can be proven for example in electromagnetism from Poynting's Theorem) and do not influence the power-balance calculations. The working efficiency is then:
[0000]
η
work
≡
P
work
P
total
≡
1
1
+
Γ
d
[
e
]
Γ
work
·
[
1
+
1
fom
[
e
]
2
(
1
+
Γ
work
Γ
d
[
e
]
)
2
]
,
(
14
)
[0000] where fom [e] =κ [e] /√{square root over (Γ s[e] Γ d[e] )} is the distance-dependent figure-of-merit of the perturbed resonant energy-exchange system. To derive Eq. (14), we have assumed that the rate Γ supply , at which the power supply is feeding energy to the resonant source, is Γ supply =Γ s[e] +κ 2 /(Γ d[e] +Γ work ), such that there are zero reflections of the fed power P total back into the power supply.
Example
Capacitively-Loaded Conducting Loops
[0188] Referring to FIG. 10 , to rederive and express this formula (14) in terms of the parameters which are more directly accessible from particular resonant objects, e.g. the capacitively-loaded conducting loops, one can consider the following circuit-model of the system, where the inductances L s , L d represent the source and device loops respectively, R s , R d their respective losses, and C s , C d are the required corresponding capacitances to achieve for both resonance at frequency ω. A voltage generator V g is considered to be connected to the source and a work (load) resistance R w to the device. The mutual inductance is denoted by M.
[0189] Then from the source circuit at resonance (ωL s =1/ωC s ):
[0000]
V
g
=
I
s
R
s
-
j
ω
MI
d
⇒
1
2
V
g
*
I
s
=
1
2
I
s
2
R
s
+
1
2
j
ω
MI
d
*
I
s
,
[0000] and from the device circuit at resonance (ωL d =1/ωC d ):
0=I d (R d +R w )−jωMI s jωMI s =I d (R d +R w )
So by substituting the second to the first:
[0000]
1
2
V
g
*
I
s
=
1
2
I
s
2
R
s
+
1
2
I
d
2
(
R
d
+
R
w
)
.
[0000] Now we take the real part (time-averaged powers) to find the efficiency:
[0000]
P
g
≡
Re
{
1
2
V
g
*
I
s
}
=
P
s
+
P
d
+
P
w
⇒
η
work
≡
P
w
P
tot
=
R
w
I
s
I
d
2
·
R
s
+
R
d
+
R
w
.
Namely
,
η
work
=
R
w
(
R
d
+
R
w
)
2
(
ω
M
)
2
·
R
s
+
R
d
+
R
w
,
[0000] which with Γ work =R w /2L d , Γ d =R d /2L d , Γ s =R s /2L s , and Γ=ωM/2√{square root over (L s L d )}, becomes the general Eq. (14). [End of Example]
[0191] From Eq. (14) one can find that the efficiency is optimized in terms of the chosen work-drainage rate, when this is chosen to be Γ work /Γ d[e] =Γ supply /Γ s[e] =√{square root over (1+fom [e] 2 )}>1. Then, η work is a function of the fom [e] parameter only as shown in FIG. 11 with a solid black line. One can see that the efficiency of the system is η>17% for fom [e] >1, large enough for practical applications. Thus, the efficiency can be further increased towards 100% by optimizing fom [e] as described above. The ratio of conversion into radiation loss depends also on the other system parameters, and is plotted in FIG. 11 for the conducting loops with values for their parameters within the ranges determined earlier.
[0192] For example, consider the capacitively-loaded coil embodiments described in Table 4, with coupling distance D/r=7, a “human” extraneous object at distance D h from the source, and that P work =10 W must be delivered to the load. Then, we have (based on FIG. 11 ) Q s[h] rad =Q d[h] rad ˜10 4 , Q s abs =Q d abs ˜10 3 , Q κ ˜500, and Q d-h abs →∞, Q s-h abs ˜10 5 at D h ˜3 cm and Q s-h abs ˜5·10 5 at D h ˜10 cm. Therefore fom [h] ˜2, so we find η≈38%, P rad ≈1.5 W, P s ≈11 W, P d ≈4 W, and most importantly η h ≈0.4%, P h =0.1 W at D h ˜3 cm and η h ≈0.1%, P h =0.02 W at D h ˜10 cm.
[0193] Overall System Performance
[0194] In many cases, the dimensions of the resonant objects will be set by the particular application at hand. For example, when this application is powering a laptop or a cell-phone, the device resonant object cannot have dimensions larger that those of the laptop or cell-phone respectively. In particular, for a system of two loops of specified dimensions, in terms of loop radii r s,d and wire radii a s,d , the independent parameters left to adjust for the system optimization are: the number of turns N s,d , the frequency f, the work-extraction rate (load resistance) Γ work and the power-supply feeding rate Γ supply .
[0195] In general, in various embodiments, the primary dependent variable that one wants to increase or optimize is the overall efficiency η. However, other important variables need to be taken into consideration upon system design. For example, in embodiments featuring capacitively-loaded coils, the design may be constrained by, for example, the currents flowing inside the wires I s,d and the voltages across the capacitors V s,d . These limitations can be important because for ˜Watt power applications the values for these parameters can be too large for the wires or the capacitors respectively to handle. Furthermore, the total loaded Q tot =ωL d /(R d +R w ) of the device is a quantity that should be preferably small, because to match the source and device resonant frequencies to within their Q's, when those are very large, can be challenging experimentally and more sensitive to slight variations. Lastly, the radiated powers P rad,s,d should be minimized for safety concerns, even though, in general, for a magnetic, non-radiative scheme they are already typically small.
[0196] In the following, we examine then the effects of each one of the independent variables on the dependent ones. We define a new variable wp to express the work-drainage rate for some particular value of fom [e] through Γ work /Γ d[e] =√{square root over (1+wp·fom [e] 2 )}. Then, in some embodiments, values which impact the choice of this rate are: Γ work /Γ d[e] =1 wp=0 to minimize the required energy stored in the source (and therefore I s and V s ), Γ work /Γ d[e] =√{square root over (1=fom [e] 2 )}>1 wp=1 to increase the efficiency, as seen earlier, or Γ work /Γ d[e] >>1 wp>>1 to decrease the required energy stored in the device (and therefore I d and V d ) and to decrease or minimize Q tot =ωL d /(R d +R w )=ω/[2(Γ d +Γ work )]. Similar is the impact of the choice of the power supply feeding rate Γ supply , with the roles of the source and the device reversed.
[0197] Increasing N s and N d increases κ/√{square root over (Γ s Γ d )} and thus efficiency significantly, as seen before, and also decreases the currents I s and I d , because the inductance of the loops increases, and thus the energy
[0000]
U
s
,
d
=
1
2
L
s
,
d
I
s
,
d
2
[0000] required for given output power P work can be achieved with smaller currents. However, increasing N d increases Q tot , P rad,d and the voltage across the device capacitance V d , which unfortunately ends up being, in typical embodiments one of the greatest limiting factors of the system. To explain this, note that it is the electric field that really induces breakdown of the capacitor material (e.g. 3 kV/mm for air) and not the voltage, and that for the desired (close to the optimal) operational frequency, the increased inductance L d implies reduced required capacitance C d , which could be achieved in principle, for a capacitively-loaded device coil by increasing the spacing of the device capacitor plates d d and for a self-resonant coil by increasing through h d the spacing of adjacent turns, resulting in an electric field (≈V d /d d for the former case) that actually decreases with N d ; however, one cannot in reality increase d d or h d too much, because then the undesired capacitance fringing electric fields would become very large and/or the size of the coil might become too large; and, in any case, for certain applications extremely high voltages are not desired. A similar increasing behavior is observed for the source P rad,s and V s upon increasing N s . As a conclusion, the number of turns N s and N d have to be chosen the largest possible (for efficiency) that allow for reasonable voltages, fringing electric fields and physical sizes.
[0198] With respect to frequency, again, there is an optimal one for efficiency, and Q tot is approximately maximum, close to that optimal frequency. For lower frequencies the currents get worse (larger) but the voltages and radiated powers get better (smaller). Usually, one should pick either the optimal frequency or somewhat lower.
[0199] One way to decide on an operating regime for the system is based on a graphical method. In FIG. 12 , for two loops of r s =25 cm, r d =15 cm, h s =h d =0, a s =a d =3 mm and distance D=2 m between them, we plot all the above dependent variables (currents, voltages and radiated powers normalized to 1 Watt of output power) in terms of frequency and N d , given some choice for wp and N s . The Figure depicts all of the dependencies explained above. We can also make a contour plot of the dependent variables as functions of both frequency and wp but for both N s and N d fixed. The results are shown in FIG. 13 for the same loop dimensions and distance. For example, a reasonable choice of parameters for the system of two loops with the dimensions given above are: N s =2, N d =6,f=10 MHz and wp=10, which gives the following performance characteristics: η work =20.6%, Q tot =1264, I s =7.2 A, I d =1.4 A, V s =2.55 kV, V d =2.30 kV, P rad,s =0.15 W, P rad,d =0.006 W. Note that the results in FIGS. 12 and 13 , and the just above calculated performance characteristics are made using the analytical formulas provided above, so they are expected to be less accurate for large values of N s , N d , still they give a good estimate of the scalings and the orders of magnitude.
[0200] Finally, one could additionally optimize for the source dimensions, since usually only the device dimensions are limited, as discussed earlier. Namely, one can add r s and a s in the set of independent variables and optimize with respect to these too for all the dependent variables of the problem (we saw how to do this only for efficiency earlier). Such an optimization would lead to improved results.
[0201] Experimental Results
[0202] An experimental realization of an embodiment of the above described scheme for wireless energy transfer consists of two self-resonant coils of the type described above, one of which (the source coil) is coupled inductively to an oscillating circuit, and the second (the device coil) is coupled inductively to a resistive load, as shown schematically in FIG. 14 . Referring to FIG. 14 , A is a single copper loop of radius 25 cm that is part of the driving circuit, which outputs a sine wave with frequency 9.9 MHz. s and d are respectively the source and device coils referred to in the text. B is a loop of wire attached to the load (“light-bulb”). The various κ's represent direct couplings between the objects. The angle between coil d and the loop A is adjusted so that their direct coupling is zero, while coils s and d are aligned coaxially. The direct coupling between B and A and between B and s is negligible.
[0203] The parameters for the two identical helical coils built for the experimental validation of the power transfer scheme were h=20 cm, a=3 mm, r=30 cm, N=5.25. Both coils are made of copper. Due to imperfections in the construction, the spacing between loops of the helix is not uniform, and we have encapsulated the uncertainty about their uniformity by attributing a 10% (2 cm) uncertainty to h. The expected resonant frequency given these dimensions is f 0 =10.56±0.3 MHz, which is about 5% off from the measured resonance at around 9.90 MHz.
[0204] The theoretical Q for the loops is estimated to be ˜2500 (assuming perfect copper of resistivity ρ=1/σ=1.7×10 −8 Ωm) but the measured value is 950±50. We believe the discrepancy is mostly due to the effect of the layer of poorly conducting copper oxide on the surface of the copper wire, to which the current is confined by the short skin depth (˜20 μm) at this frequency. We have therefore used the experimentally observed Q (and Γ 1 =Γ 2 =Γω/(2Q) derived from it) in all subsequent computations.
[0205] The coupling coefficient κ can be found experimentally by placing the two self-resonant coils (fine-tuned, by slightly adjusting h, to the same resonant frequency when isolated) a distance D apart and measuring the splitting in the frequencies of the two resonant modes in the transmission spectrum. According to coupled-mode theory, the splitting in the transmission spectrum should be Δω=2√{square root over (κ 2 −Γ 2 )}. The comparison between experimental and theoretical results as a function of distance when the two the coils are aligned coaxially is shown in FIG. 15 .
[0206] FIG. 16 shows a comparison of experimental and theoretical values for the parameter κ/Γ as a function of the separation between the two coils. The theory values are obtained by using the theoretically obtained κ and the experimentally measured Γ. The shaded area represents the spread in the theoretical κ/Γ due to the ˜5% uncertainty in Q.
[0207] As noted above, the maximum theoretical efficiency depends only on the parameter κ/√{square root over (Γ 1 Γ 2 )}=κ/Γ, plotted as a function of distance in FIG. 17 . The coupling to loss ratio κ/Γ is greater than 1 even for D=2.4 m (eight times the radius of the coils), thus the system is in the strongly-coupled regime throughout the entire range of distances probed.
[0208] The power supply circuit was a standard Colpitts oscillator coupled inductively to the source coil by means of a single loop of copper wire 25 cm in radius (see FIG. 14 ). The load consisted of a previously calibrated light-bulb, and was attached to its own loop of insulated wire, which was in turn placed in proximity of the device coil and inductively coupled to it. Thus, by varying the distance between the light-bulb and the device coil, the parameter Γ work /Γ was adjusted so that it matched its optimal value, given theoretically by √{square root over (1+κ 2 /(Γ 1 Γ 2 ))}. Because of its inductive nature, the loop connected to the light-bulb added a small reactive component to Γ work which was compensated for by slightly retuning the coil. The work extracted was determined by adjusting the power going into the Colpitts oscillator until the light-bulb at the load was at its full nominal brightness.
[0209] In order to isolate the efficiency of the transfer taking place specifically between the source coil and the load, we measured the current at the mid-point of each of the self-resonant coils with a current-probe (which was not found to lower the Q of the coils noticeably.) This gave a measurement of the current parameters I 1 and I 2 defined above. The power dissipated in each coil was then computed from P 1,2 =ΓL|I 1,2 | 2 , and the efficiency was directly obtained from η=P work /(P 1 +P 2 +P work ). To ensure that the experimental setup was well described by a two-object coupled-mode theory model, we positioned the device coil such that its direct coupling to the copper loop attached to the Colpitts oscillator was zero. The experimental results are shown in FIG. 17 , along with the theoretical prediction for maximum efficiency, given by Eq. (14).
[0210] Using this embodiment, we were able to transfer significant amounts of power using this setup, fully lighting up a 60 W light-bulb from distances more than 2 m away, for example. As an additional test, we also measured the total power going into the driving circuit. The efficiency of the wireless transfer itself was hard to estimate in this way, however, as the efficiency of the Colpitts oscillator itself is not precisely known, although it is expected to be far from 100%. Nevertheless, this gave an overly conservative lower bound on the efficiency. When transferring 60 W to the load over a distance of 2 m, for example, the power flowing into the driving circuit was 400 W. This yields an overall wall-to-load efficiency of ˜15%, which is reasonable given the expected ˜40% efficiency for the wireless power transfer at that distance and the low efficiency of the driving circuit.
[0211] From the theoretical treatment above, we see that in typical embodiments it is important that the coils be on resonance for the power transfer to be practical. We found experimentally that the power transmitted to the load dropped sharply as one of the coils was detuned from resonance. For a fractional detuning Δf/f 0 of a few times the inverse loaded Q, the induced current in the device coil was indistinguishable from noise.
[0212] The power transfer was not found to be visibly affected as humans and various everyday objects, such as metallic and wooden furniture, as well as electronic devices large and small, were placed between the two coils, even when they drastically obstructed the line of sight between source and device. External objects were found to have an effect only when they were closer than 10 cm from either one of the coils. While some materials (such as aluminum foil, styrofoam and humans) mostly just shifted the resonant frequency, which could in principle be easily corrected with a feedback circuit of the type described earlier, others (cardboard, wood, and PVC) lowered Q when placed closer than a few centimeters from the coil, thereby lowering the efficiency of the transfer.
[0213] We believe that this method of power transfer should be safe for humans. When transferring 60 W (more than enough to power a laptop computer) across 2 m, we estimated that the magnitude of the magnetic field generated is much weaker than the Earth's magnetic field for all distances except for less than about 1 cm away from the wires in the coil, an indication of the safety of the scheme even after long-term use. The power radiated for these parameters was ˜5 W, which is roughly an order of magnitude higher than cell phones but could be drastically reduced, as discussed below.
[0214] Although the two coils are currently of identical dimensions, it is possible to make the device coil small enough to fit into portable devices without decreasing the efficiency. One could, for instance, maintain the product of the characteristic sizes of the source and device coils constant.
[0215] These experiments demonstrated experimentally a system for power transfer over medium range distances, and found that the experimental results match theory well in multiple independent and mutually consistent tests.
[0216] We believe that the efficiency of the scheme and the distances covered could be appreciably improved by silver-plating the coils, which should increase their Q, or by working with more elaborate geometries for the resonant objects. Nevertheless, the performance characteristics of the system presented here are already at levels where they could be useful in practical applications.
APPLICATIONS
[0217] In conclusion, we have described several embodiments of a resonance-based scheme for wireless non-radiative energy transfer. Although our consideration has been for a static geometry (namely κ and Γ e were independent of time), all the results can be applied directly for the dynamic geometries of mobile objects, since the energy-transfer time κ −1 (˜1 μs−1 ms for microwave applications) is much shorter than any timescale associated with motions of macroscopic objects. Analyses of very simple implementation geometries provide encouraging performance characteristics and further improvement is expected with serious design optimization. Thus the proposed mechanism is promising for many modern applications.
[0218] For example, in the macroscopic world, this scheme could potentially be used to deliver power to for example, robots and/or computers in a factory room, or electric buses on a highway. In some embodiments source-object could be an elongated “pipe” running above the highway, or along the ceiling.
[0219] Some embodiments of the wireless transfer scheme can provide energy to power or charge devices that are difficult or impossible to reach using wires or other techniques. For example some embodiments may provide power to implanted medical devices (e.g. artificial hearts, pacemakers, medicine delivery pumps, etc.) or buried underground sensors.
[0220] In the microscopic world, where much smaller wavelengths would be used and smaller powers are needed, one could use it to implement optical inter-connects for CMOS electronics, or to transfer energy to autonomous nano-objects (e.g. MEMS or nano-robots) without worrying much about the relative alignment between the sources and the devices. Furthermore, the range of applicability could be extended to acoustic systems, where the source and device are connected via a common condensed-matter object.
[0221] In some embodiments, the techniques described above can provide non-radiative wireless transfer of information using the localized near fields of resonant object. Such schemes provide increased security because no information is radiated into the far-field, and are well suited for mid-range communication of highly sensitive information.
[0222] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention.
|
Disclosed is an apparatus for use in wireless energy transfer, which includes a first resonator structure configured to transfer energy non-radiatively with a second resonator structure over a distance greater than a characteristic size of the second resonator structure. The non-radiative energy transfer is mediated by a coupling of a resonant field evanescent tail of the first resonator structure and a resonant field evanescent tail of the second resonator structure.
| 7
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RELATED APPLICATION DATA
The present application is a continuation-in-part of application Ser. No. 09/669,359 now U.S. Pat. No. 6,503,666, filed Sep. 26, 2000; which application claims the benefit of prior U.S. Provisional Application No. 60/215,938; filed Jul. 5, 2000; entitled Phase Shift Masking for Complex Layouts, invented by Christophe Pierrat, which is incorporated by reference as if fully set forth herein.
The present application is related to U.S. patent application Ser. No. 09/669,368 now U.S. Pat. No. 6,524,752, entitled Phase Shift Masking for Intersecting Lines, invented by Christophe Pierrat, filed Sep. 26, 2000, and owned by the same assignee now and at the time of invention; and also related to U.S. patent application Ser. No. 09/669,367 now U.S. Pat. No. 6,541,165, entitled Phase Shift Mask Sub-Resolution Assist Features, invented by Christophe Pierrat, filed 26 Sep. 2000, and owned by the same assignee now and at the time of invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to manufacturing small dimension features of objects, such as integrated circuits, using photolithographic masks. More particularly, the present invention relates to the application of phase shift masking to complex layouts for integrated circuits and similar objects.
2. Description of Related Art
Phase shift masking, as described in U.S. Pat. No. 5,858,580, has been applied to create small dimension features in integrated circuits. Typically the features have been limited to selected elements of the design, which have a small, critical dimension. Although manufacturing of small dimension features in integrated circuits has resulted in improved speed and performance, it is desirable to apply phase shift masking more extensively in the manufacturing of such devices. However, the extension of phase shift masking to more complex designs results in a large increase in the complexity of the mask layout problem. For example, when laying out phase shift areas on dense designs, phase conflicts will occur. One type of phase conflict is a location in the layout at which two phase shift regions having the same phase are laid out in proximity to a feature to be exposed by the masks, such as by overlapping of the phase shift regions intended for implementation of adjacent lines in the exposure pattern. If the phase shift regions have the same phase, then they do not result in the optical interference necessary to create the desired effect. Thus, it is necessary to prevent inadvertent layout of phase shift regions in phase conflict.
Another problem with laying out complex designs which rely on small dimension features, arises because of isolated exposed spaces which may have narrow dimension between unexposed regions or lines.
Because of these and other complexities, implementation of a phase shift masking technology for complex designs will require improvements in the approach to the design of phase shift masks, and new phase shift layout techniques.
SUMMARY OF THE INVENTION
The present invention provides techniques for extending the use of phase shift techniques to implementation of masks for complex layouts in the layers of integrated circuits, beyond selected critical dimension features such as transistor gates to which such structures have been limited in the past. The invention provides a method that includes identifying features for which phase shifting can be applied, automatically mapping the phase shifting regions for implementation of such features, resolving phase conflicts which might occur according to a given design rule, and applying sub-resolution assist features within phase shift regions. The present invention is particularly suited to opaque field phase shift masks which are designed for use in combination with binary masks defining interconnect structures and other types of structures that are not defined using phase shifting, necessary for completion of the layout of the layer.
Various aspects of the invention include computer implemented methods for definition of mask layouts for corresponding complex layouts in the layers of integrated circuits to be made using such masks, methods for manufacturing masks having such mask layouts, methods for manufacturing integrated circuits having improved small dimension features implemented using the novel masks, and improved integrated circuits having the improved small dimension features.
The invention includes a method for producing photolithographic masks, and layout files for such photolithographic masks, which comprises identifying features in a pattern to be exposed having a dimension less than a particular feature size, and laying out phase shift regions using a layout rule for the identified features to produce a phase shift mask having phase shift areas. The particular feature size according to the invention need not be the critical dimension for the smallest features to be implemented. Rather, in the layout of an entire complex pattern, any feature which is suitable for implementation using phase shifting can be identified according to the present invention.
In one embodiment, the process of identifying features suitable for implementation using phase shifting includes reading a layout file which identifies features of the complex pattern to be exposed.
In one preferred embodiment, the phase shift mask includes an opaque field, and the phase shift regions include a plurality of transparent regions having a first phase within the opaque field, and a plurality of complementary transparent regions having a second phase 180 degrees out of phase with respect to the first phase, within the opaque field. The opaque field leaves unexposed lines formed by the phase shift regions unconnected to other structures. A complementary mask is laid out for use is conjunction with the opaque field phase shift mask to form interconnect structures in the region blocked by the opaque field, so the features formed using the phase shift mask are integrated with larger dimension features. In one embodiment, the complementary mask is a binary mask, without phase shifting features.
As a result of the layout rule, regions in the phase shift mask may result in phase conflicts. Thus, the invention also includes applying an adjustment to one or more of the phase shift regions in the phase shift mask to correct for phase conflicts. The adjustment in one preferred embodiment comprises dividing a phase shift region having a first phase into a first phase shift region having the first phase in a second phase shift region having the second phase. An opaque feature is added to the phase shift mask between the first and second phase shift regions. The complementary mask includes a corresponding opaque feature preventing exposure of the features to be exposed using the first and second phase shift regions in the phase shift mask, and includes a cut-out over the opaque feature separating the first and second phase shift regions to expose any feature resulting from the phase difference between the first and second phase shift regions. In one embodiment, the unique structure which results from the adjustment is laid out in the first instance to prevent phase conflicts in the layout, and so may not be considered an “adjustment” to correct a phase conflict in the layout.
For example, phase conflicts can arise in the implementation of a pattern consisting of an intersection of an odd number of line segments. The odd number of line segments defines a plurality of corners at the intersection. In this case, phase shift regions are laid out adjacent the line segments on either side of the corner so they have the same phase, and in one embodiment continuing around the corner in all of the plurality of corners. In one identified corner, the phase shift regions is divided into a first phase shift region having the first phase adjacent the line segment on one side of the corner, and a second phase shift region having the second phase adjacent the line segment on the other side of the corner. An opaque feature is added between the first and second phase shift regions in the one corner. The complementary mask includes a corresponding opaque feature preventing exposure of the intersecting line segments left unexposed by the phase shift mask, and includes a cut-out over the opaque feature separating the first and second phase shift regions to expose any feature resulting from the phase difference in the one excepted corner between the first and second phase shift regions.
In another embodiment the phase shift regions are laid out adjacent the line segments, and ending near the corners in all of the plurality of corners. In all the corners except one identified corner, or in more than one identified corner having sufficient process latitude, a first phase shift region having the first phase laid out adjacent the line segment on one side of the corner, and a second phase shift region having the second phase laid out adjacent the line segment on the other side of the corner are merged. An opaque feature is added between the first and second phase shift regions in the one identified corner. The complementary mask includes a corresponding opaque feature preventing exposure of the intersecting line segments left unexposed by the phase shift mask, and includes a cut-out over the opaque feature separating the first and second phase shift regions to expose any feature resulting from the phase difference in the one identified corner between the first and second phase shift regions.
The selection of the one identified corner having the cut-out feature in the structure that defines the intersection of an odd number of line segments is implemented in various embodiments according to design rules. In one design rule, the one excepted corner is the corner defining the largest angle less than 180 degrees. In another design rule, the one excepted corner is the corner which is the greatest distance away from an active region on the integrated circuit.
In one embodiment, the pattern to be implemented includes exposed regions and unexposed regions. Exposed regions between unexposed regions (i.e., spaces between lines or other structures) having less than a particular feature size are identified for assist features. The particular feature size used for identification of exposed regions between unexposed regions may or may not be the same as the feature size used for selection of unexposed regions (i.e., lines) to be implemented using phase shift masking. According to this aspect of the invention, the process includes laying out phase shift regions in the phase shift mask to assist definition of edges of the unexposed regions between exposed regions.
According to another aspect of the invention, the process includes adding sub-resolution assist features inside a particular phase shift region in the phase shift mask. The sub-resolution features comprise in various embodiments features inside and not contacting the perimeter of the particular phase shift region. In other embodiments, the sub-resolution features result in division of a phase shift region having a first phase into first and second phase shift regions having the same phase. An opaque feature between the first and second phase shift regions acts as a sub-resolution feature to improve the shape of the resulting exposed and unexposed regions.
The sub-resolution features do not “print” in the image being exposed, but affect the intensity profile at the wafer level, such as by improving contrast of the image and thereby improving process latitude, and changing the size of the printed image caused by the phase shift region in which the sub-resolution feature is laid out, such as for optical proximity correction OPC.
According to another aspect of the invention, the layout of phase shifting regions in an opaque field includes a step of simulating an intensity profile or other indication of the exposure pattern to be generated, and locating regions in the exposure pattern which are anomalous, such as by having higher intensity. Sub-resolution features are then added to the layout covering the anomalous regions in the exposure pattern.
The use of sub-resolution features within phase shift regions is applied uniquely for the formation of an array of closely spaced shapes, such as an array of capacitor plates used in dynamic random access memory designs.
An overall process for producing a layout file, or a photolithographic mask is provided that includes identifying features to be implemented using phase shifting, laying out phase shifting regions so as to prevent or minimize phase conflicts, applying sub-resolution assist features to the phase shift regions, and producing a layout file. Next, a complementary mask is laid out to complete definition of the exposure pattern so that features that are not implemented using the phase shift mask are interconnected with the features implemented by the phase shift mask.
A method for producing integrated circuits having improved small dimension structures includes applying a photo-sensitive material to a wafer, exposing the photo-sensitive material using the phase shift mask implemented as described above, exposing the photo-sensitive material using the complementary mask implemented as described above, and developing the photo-sensitive material. A next process step in the method for producing integrated circuits involves the removal of material underlying the photo-sensitive material according to the resulting pattern, or addition of material over the wafer according to the pattern resulting from the use of the phase shift and complementary masks. The resulting integrated circuit has improved, and more uniform line widths, and improved and more uniform spaces between structures on the device. In some embodiments, the resulting integrated circuit has intersecting lines defined with phase shift masks.
The invention results, therefore, in methods for producing mask layout files and photolithographic masks based on such layout files suitable for the implementation of complex designs extensively using phase shifting structures to define small dimension features. New manufacturing techniques and improved integrated circuits are therefore provided.
Other aspects and advantages of the present invention can be understood with review of the figures, the detailed description and the claims which follow.
BRIEF DESCRIPTION OF THE FIGURES
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
FIG. 1 illustrates a binary mask and FIG. 2 illustrates a phase shift mask according to a prior art phase shift masking technique.
FIG. 3 is a plot of the intensity profile of an exposure made using the masks of FIGS. 1 and 2 according to the prior art.
FIG. 4 illustrates a binary mask, and FIG. 5 illustrates a phase shift mask according to the present invention for implementing the same shape as implemented with FIGS. 1 and 2.
FIG. 6 is a plot of the intensity profile of an exposure made using the masks of FIGS. 4 and 5 according to the present invention.
FIG. 7 is a binary mask, and FIG. 8 is a phase shift mask for implementation of a feature comprising three intersecting line segments according to the present invention.
FIG. 9 is a plot of the intensity profile of an exposure made using the masks of FIGS. 7 and 8.
FIG. 10 is a binary mask, and FIG. 11 is a phase shift mask for implementation of a feature comprising five intersecting line segments according to the present invention.
FIG. 12 illustrates a phase shift mask for implementation of a double “T” structure.
FIG. 13 illustrates an alternative phase shift mask for implementation of a double “T” structure according to the present invention.
FIG. 14 illustrates one example of the layout of a phase shift mask according to the present invention for a complex pattern.
FIGS. 15A and 15B illustrate the layout, a simulation, and contour plots of a prior art phase shift mask for implementation of a dense array of capacitor plates on integrated circuit.
FIGS. 16A and 16B illustrate the layout, a simulation, and contour plots of the phase shift mask for implementation of a dense array of capacitor plates on an integrated circuit according to the present invention.
FIG. 17A illustrates a phase shift mask having sub-resolution assist features, for implementation of a exposure pattern as shown in FIG. 17 B.
FIG. 17B shows an exposure pattern which results from the phase shift mask of FIG. 17A, and an exposure pattern which would result from the phase shift mask of FIG. 17A without the assist features.
FIG. 18 is a flow chart of a process for producing layout files, and phase shift mask and manufacturing integrated circuits according to the present invention.
DETAILED DESCRIPTION
A detailed description of the present invention is provided with respect to FIGS. 1-18. FIGS. 1-3 illustrate problems associated with the layout and manufacturing of small dimension features according to the prior art. FIGS. 4-6 illustrate an approach to improving the layout and manufacturing of the small dimension features shown in FIGS. 1-3 according to the present invention. FIGS. 7-18 illustrate additional features and techniques.
FIG. 1 shows a binary mask for use in combination with an opaque field phase shift mask as shown in FIG. 2 . The binary mask of FIG. 1 includes an opaque feature within a clear field 10 . The opaque feature includes a blocking region 11 which corresponds to the features, i.e. transistor gates in an active region of a device, formed using the phase shift structures of FIG. 2 . Narrow lines 12 , 13 and 14 extend from the blocking region 11 to respective flag shaped elements 15 , 16 , 17 . The narrow lines 12 , 13 , 14 in this example each extend through the blocking region 11 , resulting in respective extension portions 18 , 19 , 20 . The phase shift mask of FIG. 2 is formed within an opaque field 25 , inside which zero degree phase shift regions 26 , 27 and 180 degree phase shift regions 28 , 29 are formed. The phase shift regions result in the printing of fine lines on the transitions between zero degree region 26 and 180 degree region 28 , between 180 degree region 28 and zero degree region 27 , and between zero degree region 27 and 180 degree region 29 . These fine lines are coupled with the lines 12 , 13 , 14 in the binary mask of FIG. 1 for interconnection, while the blocking region 11 prevents exposure of the fine lines during the exposure using the binary mask.
FIG. 3 shows the resulting fine lines 30 , 31 , 32 in the active region of the layout. The long narrow lines 12 , 13 , 14 interconnect the fine lines 30 , 31 , 32 with the flag shaped features 15 , 16 , 17 . In the FIG., the regions 35 and 36 do not print, but are higher intensity regions which show dark as artifacts of black and white printing of the color image generated using a simulation program.
Issues associated with this technique include the poor quality of the image of isolated lines, such as long line 12 , and of the narrow spaces, such as between the flag shaped features 16 and 17 . Classical optical proximity correction techniques can be applied to improve dimensional control of these images, however such processes according to the prior art do not improve process latitude, making the structures difficult to manufacture.
FIGS. 4 and 5 show the binary mask and phase shift mask implemented according to the present invention, extending phase shifting techniques to the more complex circuit pattern beyond the transistor gates in the active region. The binary mask of FIG. 4 is formed in a clear field 40 . It includes blocking features 41 and 42 . The pattern elements which are common with FIG. 1 have like numbers, so the extensions 18 , 19 , 20 and the flag shaped features 15 , 16 , 17 have the same reference numbers. A corresponding phase shift mask shown in FIG. 5 includes an opaque field 50 . The phase shifting regions have been extended along the entire lengths of the lines excluding the extensions 18 , 19 , 20 in this example. In addition, phase shifting in the region 49 is used to assist the definition of the edges of the flag shaped regions 16 and 17 in the narrow space between them. Thus, zero degree phase shift regions 45 and 47 are formed, and 180 degree phase shift regions 46 and 48 are formed. The phase shift regions 45 , 46 and 47 extend to the lower edges 51 , 52 of the flag shaped regions 16 , 17 .
A simulation of image resulting from application of the masks of FIGS. 4 and 5, is shown in FIG. 6, in which the regions 54 , 55 , 56 and 57 are nonprinting artifacts as mentioned above of the black and white printing of the color simulation image. The long lines corresponding to the lines 12 , 13 , 14 of FIG. 1 are printed entirely using phase shifting, so that quality, narrow dimension features 51 , 52 and 53 result. The phase shifting assist feature between and on the edges of the flag shaped patterns 16 , 17 results in better definition of the edges 58 , 59 between the regions 16 , 17 . Thus, FIGS. 4-6 illustrate the application of phase shifting techniques to complex circuit pattern beyond the active regions of the device.
FIGS. 7, 8 and 9 illustrate a technique used for layout of complex structures comprising an odd number of intersecting line segments using phase shift masking. FIG. 7 shows a binary mask in a clear field 60 comprising an opaque feature 61 corresponding to a first of intersecting line segments, an opaque feature 62 corresponding to a second of the intersecting line segments, and an opaque feature 63 corresponding to a third of the intersecting line segments. A corner cut-out region 64 is formed according to present technique is described further below. FIG. 8 shows a phase shift mask in an opaque field 70 for formation of the intersecting line segments, and for use in combination with the complementary mask of FIG. 7 . The phase shift mask includes 180 degree phase shift region 71 , 180 degree phase shift region 72 , zero degree phase shift region 73 , and zero degree phase shift region 74 . As can be seen, the 180 degree phase shift region 71 extends adjacent the line segments,corresponding to the regions 61 and 62 and around the corner between regions 61 and 62 . Also, the zero degree phase shift region 74 extends adjacent to line segments and 62 and 63 and through the “corner” formed by the 180 degree angle in the intersection two line segments. The phase shift regions 72 and 73 extend along the line segment 63 adjacent one side of the corner and along the other side 61 of the corner, respectively and have opposite phases. An opaque feature is laid out in the corner between the two phase shift regions 72 and 73 . The cut-out feature 64 in the binary mask of FIG. 7 tends to expose the artifact which would be created by the phase transition in the corner between phase shift regions 72 and 73 .
FIG. 9 shows the simulation of the image printed using the phase shift mask of FIG. 8, with a binary mask of FIG. 7 . The features 81 , 82 , 83 and 84 are nonprinting artifacts of the simulation program. The “T” shaped feature 85 results from the phase shift masking technique with corner cutting. As can be seen, the narrow lines are formed with relatively uniform thickness and straight sides. In the corner 86 which corresponds to the cut-out feature 64 of FIG. 7, the feature 85 is slightly less sharp than in the other corners. The shape of the printed corner could be improved by applying some correction to the cut-out 64 and the shifters 72 and 73 .
FIGS. 10 and 11 illustrates the “corner cutting” technique as applied to a structure comprising five intersecting line segments. Thus, FIG. 10 shows a binary mask 100 including an opaque feature having blocking structure 101 corresponding to a first line segment, blocking structure 102 corresponding to a second line segment, blocking structure 103 corresponding to a third line segment, blocking structure 104 corresponding to the fourth line segment, and blocking structure 105 corresponding to the fifth line segment. A corner cut-out feature 106 is formed between the line segments 101 and 105 .
FIG. 11 shows the phase shift mask for use in combination with the binary mask of FIG. 10 . The phase shift mask of FIG. 11 is formed in an opaque field 110 . 180 degree phase shift regions 111 , 112 and 113 are laid out in an alternating fashion as shown FIG. 11 . Zero degree phase shift regions 114 , 115 and 116 are laid out in a complementary fashion to define the five intersecting line segments. An opaque feature is formed between the phase shift regions 114 and 113 . The artifact which would be created by the phase transition between the phase shift regions 113 and 114 is exposed by the cut-out 106 in the binary mask of FIG. 10 . In addition, the shape of the opaque feature in the phase shift mask between the phase shift regions 113 the shape of the art-out 106 can also be optimized and 114 can be modified using optical proximity correction techniques to improve that resulting image. The shape of the cut-out 106 can also be optimized.
A structure and a process for controlling phase mismatches on inside corners of complex structures is provided. Inside corner cut-outs are formed on the binary masks to block artifacts of phase transition in the corner, and phase shift regions are adjusted by dividing them into first and second phase shift regions of opposite phase, and reshaping them on inside corners to accommodate and optimize the effects of the inside corner extensions. The corners at which the extensions are applied can be simply decided by applying them to all inside corners, when shapes of the corners are not critical. Alternatively, the corner extensions can be applied only in one corner of a structure having an odd number of intersecting segments, such as one corner corresponding to a region in the layer characterized by greater process latitude than other corners. The corner is picked, for example, by selecting an inside corner having the greatest distance from an active area on the device, or an inside corner having a largest angle less than 180 degrees.
The selection of corners for the phase mismatch extensions may affect the assignment of zero and 180 degree phase shift regions. Thus it may be desirable to select the corners for inside corner extensions prior to “coloring” the layout with phase assignments. A first approach to avoiding the corner conflicts is simply to select the phase shift areas in a manner that does not cause a conflict. Of course this is not always possible. Next, the conflicts can be left in regions on the chip where the design rules will tolerate the artifacts caused by the phase mismatch, or in other words, in regions characterized by greater process latitude than the alterative locations, in the exposure patterns that result from the corner cut. In one example process, the corner extensions are applied on all inside corners, then the layout is colored to assigned phases, and then corners are rebuilt with optimized shapes. Alternatively, simplified phase assignment can be utilized when all corners are provided with phase mismatch extensions.
FIGS. 12 and 13 illustrate problems encountered in the layout of a so-called double “T” structure. In FIG. 12, a phase shift mask in an opaque field 120 is shown for forming a double “T” structure having vertical line segments 121 and 122 intersecting with horizontal line segment 123 . Vertical line segments 121 and 122 are close together, so a single phase shift region 123 is formed between them. In this case, phase shift region 123 is a zero degree phase shift region. Phase shift region 124 beneath the line segment 123 is also a zero degree phase shift region creating a phase conflict in the region 129 between the vertical line segments 121 and 122 . 180 degree phase shift regions 125 , 126 , 127 and 128 are formed along the line segments in the corners as shown. The shapes of regions 125 , 126 , 127 , 128 have not been optimized in the corner in this example. The phase shift regions do not extend to all the way to the intersection of the line segments in this example. The phase mismatch in the region 129 can result in an aberration image such that the quality of the line segments in that region is reduced. The assumption is that the distance between 121 and 122 is small enough that the printing of the region 129 will not be critical.
FIG. 13 illustrates a double “T” structure with vertical line segments 131 and 132 formed in an opaque field 130 . In this case, separate phase shift regions 133 and 134 are formed between the vertical line segments 131 and 132 . A 180 degree phase shift region 135 is formed between them along the horizontal line segment 136 . This resolves the phase mismatch which would have occurred with the zero degree phase shift region 137 according to the structure of FIG. 12, and allows for higher quality printing of the images. In this case, the corner cutting technique utilizes simple square shaped opaque features in the corners, rather than the diagonal shape shown in FIGS. 8 and 11. The square shape of FIGS. 12 and 13 may be simpler to implement using a layout program in a processor with more limited power.
FIG. 14 provides a close-up of a portion of the layout of a phase shift mask in an opaque field for a layer of an integrated circuit structure. As can be seen, a comb shaped structure 141 is formed with zero degree phase shift regions (hatched, e.g. region 142 ) generally on the upper and left and 180 degree regions (clear, e.g. region 143 ) generally on the lower and right. All inside corners are blocked with square opaque features (e.g. feature 144 ) in this example to minimize phase conflicts.
The generation of phase shift masks for a complex structure is a nontrivial processing problem. Automatic assignment of phase shift regions, and addition of optical proximity correction features and corner features for preventing phase shift mismatches as described above are provided in this example to facilitate processing. Three stages in the generation of phase shift mask layouts according to the process which is implemented using a design rule checking programming language (e.g. Vampire (TM) Design Rule Checker provided by Cadence Design Systems, Inc.) as follows:
Definition of the input layers:
L13 =
layer(13 type(0))
L13 is the original poly layer
L12 =
layer(11 type(0))
L12 is the original poly layer shifted in the x and y direction by
0.02 micron
Generation of the output layers:
L2 =
geomSize(L13 −0.01 edges)
size L13 by −0.01 only edges (inner corners are not moved)
L2_1 =
geomAndNot(L13 L2)
L2_2 =
geomSize(L2_1 0.01)
L3 =
geomAndNot(L2_2 L13)
marker: 0.01 by 0.01 square in inner corners of L13)
L4 =
geomSize(L13 0.01)
L5 =
geomSize(L13 0.01 edges)
size L13 by 0.01 only edges(outer corners are not moved)
L5_1 =
geomAndNot(L4 L5)
L6 =
geomAndNot(L5_1 L13)
marker: 0.01 by 0.01 square at the tips of outer corners
L6_1 =
geomSize(L6 0.14)
L6_2 =
geomSize(L13 0.15 edges)
L6_3 =
geomAndNot(L6_1 L6_2)
L6_4 =
geomSize(L6_3 0.14)
L6_5 =
geomSize(L6_4 −0.14)
merges any 0.28 and below gaps
L6_6 =
geomSize(L6_5 −0.02)
L6_7 =
geomSize(L6_6 0.02)
removes any 0.04 and below geometries
L7 =
geomAndNot(L6_7 L13)
L7 = layer to be removed from phase layer to cut the
outer corners
L3_1 =
geomSize(L3 0.15)
L8 =
geomAndNot(L3_1 L13)
L8 = layer to be removed from phase layer to cut the
inner corners
L8_1 =
geomOr(L7 L8)
add together the layers to be removed from the phase layer
L8_2 =
geomSize(L13 −0.01)
L8_3 =
geomSize(L8_2 0.1)
removes any 0.2 micron and below geometries
L8_4 =
geomAndNot(L13 L8_3)
L13 without geometries larger than 0.2 micron
L9 =
geomSize(L8_4 0.15)
L9_1 =
geomAndNot(L9 L8_1)
L9_2 =
geomAndNot(L9_1 L13)
L9_3 =
geomSize(L9_2 −0.03)
L20 =
geomSize(L9_3 0.03)
−0.03/0.03 to remove any geometry below 0.06 micron
L10 = phase shifter layer (no coloring performed)
L11 =
geomOverlap(L10 L12)
0 degree phase-shift layer
L14 =
geomAndNot(L10 L11)
180 degree phase-shift layer
A design rule checker can be utilized to identify all exposed features (i.e. lines) and unexposed features (i.e. spaces between lines) of an input layout that have a size less than a minimum feature dimension. Features subject of the minimum feature dimension may constitute structures or spaces between structures. Different minimum feature dimensions are applied to lines and to spaces in one embodiment. Thus, minimum feature structures can be identified by subtracting slightly more than ½ of a minimum feature dimension for lines from the original size of an input structure. This results in eliminating all structures which have a dimension less than the minimum dimension. The remaining structures can then be reconstituted by adding slightly more than ½ of the minimum dimension back. Minimum dimension structures can then be identified by taking the original input structure and subtracting all structures which result from the reconstitution step. This process can be characterized as performing a size down operation to eliminate small dimension features followed by a size up operation on remaining edges to produce a calculated layout. The small dimension features are then identified performing an “AND NOT” operation between the original layout AND NOT and the calculated layout.
Narrow spaces can be identified by an opposite process. In particular, slightly more than ½ of the minimum feature dimension for spaces is added to the original size of the structure. This added length or width causes structures that are close together to overlap and merge. Next, the remaining structures are reconstituted by subtracting slightly more than ½ of the minimum feature dimension from the sides of structures remaining. Narrow regions are identified by taking the reconstituted remaining structures and subtracting all original structures. Thus, a process can be characterized as performing a size up operation to eliminate small dimension spaces, followed by a size down operation on the remaining edges to produce a calculated layout. The small dimension spaces are then identified by performing an “AND NOT” operation between the calculated layout and the original layout.
The next step in the procedure for automatic generation of phase shift mask layouts involves identifying all corners in the structure. Inside corners and outside corners are identified. Outside corners are blocked to define ends of phase shift regions. Inside corners may result in a phase mismatches discussed above. Inside corners are blocked, and thus provided with an extension of the opaque region, such as a square extension, and a shortening of the phase shift regions so that they do not extend all the way to the inside corner. This square extension is applied in all inside corners, whether a phase mismatch is found or not. Alternatively, the extension is applied only where phase mismatches occur.
Phase shift regions are formed in a simple case, by copying the input structures in the minimum dimension features, and shifting up and to the left for 180 degree (or zero degree) shifters, and down and to the right for zero degree (or 180 degree) shifters. The blocking regions formed for the outside corners cut the shifted regions at the ends of the input structures, and the blocking structures formed on the inside corners cut the shifted regions at the inside corners of the structure to provide well formed phase shift mask definitions. The phase “coloring” can be applied to the resulting phase shift regions in other ways, including manually, so that the zero and 180 degree regions are properly laid out.
The limitation of this simple technique is that the shifts in the X and Y directions need to be carefully chosen if there is any polygon at an angle different from 0 to 90°.
All inside corners are blocked in the example shown in FIG. 14 . However, in a preferred system, inside corners for which no phase conflict is encountered would be filled with a phase shift region.
In another embodiment, the inside corner extensions which block phase mismatches, are not applied on inside corners adjacent active regions of devices that are near the corners, if a choice is possible. For structures having an odd number of segments intersecting, the location of the phase mismatch, and application of the corner extension, can be chosen at the angle farthest from the active regions in the device, or at the largest angle.
Once the inside corner extensions are identified, the extensions can be optimally shaped to improve the resulting exposure pattern, such as by changing the squares to diagonally shaped regions shown in FIGS. 8 and 11. Other principles of optical proximity correction can be applied to enhance the shapes of the inside corner extensions. Likewise, the phase shift regions can be shaped adjacent the inside corners to enhance performance. In one example system transitions may be enhanced between the phase shift regions by placing a 90 degree phase shift region between conflicting zero and 180 degree phase shift regions.
FIGS. 15A and 15B illustrate a prior art technique for laying out an array of dense shapes, such as a capacitor plate array in the layout of a dynamic random access memory device. A phase shift mask as shown in FIG. 15A is used to form the array. The phase shift mask includes a column 200 of alternating phase transparent areas within an opaque field 201 . Likewise adjacent columns alternate in phase in a complementary manner as shown. This results in the printing of lines on transitions between the alternating phase shift areas and exposing regions inside the phase shift regions. FIG. 15B illustrates the simulation of the exposure pattern. As can be seen, a dense array of oval patterns is caused by the layout of FIG. 15 A. For a denser array, it is desirable to make the exposed patterns more rectangular in shape.
FIG. 16A illustrates an adjustment to the phase shift layout according to the present invention to make the exposed patterns more rectangular. According to this technique, the phase shift regions have been adjusted so that they consist of a first phase shift area 215 and a second phase shift area 216 having the same phase with an opaque sub-resolution feature 217 in between. Likewise, all of the phase shift regions have been split into two phase shift regions as shown with sub-resolution features in between. Note that the assist feature which divides the phase shift region is not necessarily smaller than the phase shift region. Lines are printed at the phase transitions, and the sub-resolution features between the like-phase regions do not print. The resulting pattern is shown in FIG. 16B, where the exposure shows features having much straighter sides and covering much greater area than those of FIG. 15 B. In the simulation plot of FIG. 16B, the dark outlines, such as line 211 , illustrate the final contour of the exposed region. Thus, a technique for improving the images which result from use of phase shift areas involves adjusting a phase shift area having a particular phase into a first phase shift area and a second phase shift area having the same particular phase and adding a sub-resolution feature in between.
FIGS. 17 and 18 illustrate the use of sub-resolution features within the phase shift regions according to another technique of the present invention. In FIG. 17, an opaque field 250 is shown with a first phase shift region 251 and a second phase shift region 252 having an opposite phase. Sub-resolution assist features 253 and 254 are formed within the phase shift region 251 . Sub-resolution assist features 255 and 256 are formed within the phase shift region 252 . As can be seen, the phase shift regions 251 and 252 have respective perimeters. The sub-resolution features 253 , 254 , 255 , 256 are inside of the phase shift regions and do not contact the perimeters in this example.
FIG. 18 shows simulation of the exposure patterns resulting from the phase shift mask of FIG. 17 . In the top, images 260 and 261 are shown which correspond to the use of the phase shift mask of FIG. 17 . Images 262 and 263 correspond to the use of the phase shift mask of FIG. 17 without the sub-resolution assist features 253 - 256 . As can be seen, with the sub-resolution assist features 253 - 256 , the lines are much straighter and the exposure patterns are much more uniform. According to one technique, the sub-resolution features are placed within the phase shift regions by first simulating the exposure patterns without the sub-resolution assist features. Hot spots, such as hot spot 264 in the simulation image 263 or other anomalies, are identified. Sub-resolution features are then placed over the anomalies. Thus, sub-resolution feature 255 corresponds to the hot spot 264 .
The techniques for improving phase shift masking for complex layouts outlined above are combined into a process for producing phase shift layout data and manufacturing phase shift masks for complex layouts, as shown in FIG. 19 . The process is also extended to the manufacturing of integrated circuits with improved structures. Thus, according to the present invention, the manufacturing process involves reading a layout file which defines a complex layer of an integrated circuit (step 300 ). For example, in one embodiment the layer comprises polysilicon or another conductive material used as transition gates and interconnect structures. Next, features to be left unexposed by the mask are identified which have a dimension less than a first particular value (step 301 ). Then, features to be exposed and having a dimension less the second particular value are identified (step 302 ). The first and second particular values may be the same value or different, as suits the particular implementation.
Next, the process involves laying out phase shift regions for the identified features according to a design rule (step 303 ). One example design rule involves laying out phase shift regions having a zero degree phase (or 180 degree phase) to the upper left, and a phase shift regions having the opposite phase, such as 180 degree phase (or zero degree phase) to lower right. This simple phase shift layout rule results in phase conflicts, where adjacent phase shift regions have the same phase so phase transitions do not occur. Any other phase assignment technique can be used. The phase conflicts are identified in a next step (step 304 ). Adjustments are applied to the phase shift regions based on identified phase conflicts (step 305 ). For example, the corner cutting technique described with respect to FIGS. 7-11 is applied. In a next step, the exposure pattern is simulated and assist features are added to the phase shift regions based on the simulation (step 306 ). Rather than using simulation for placement of sub-resolution assist features, the locations of the sub-resolution features can be determined based on design rules. For example, one design rule is to place a 0.1 μm square assist feature, 0.2 μm away from the edge of the phase shift region. Thus, phase shift regions may be adjusted using sub-resolution assist features within the perimeter of the phase shift region, or by dividing the phase shift region as described with reference to FIGS. 16A and 17.
In a next step, other optical proximity correction techniques are applied and the phase shift mask layout is completed (step 307 ). A complementary mask is then laid out, including the corner cut-outs as necessary for intersecting line segments and the like (step 308 ).
With the completed phase shift and complementary mask layouts, the masks are printed using techniques known in the art (step 309 ). See, U.S. Pat. Nos. 6,096,458; 6,057,063; 5,246,800; 5,472,814; and 5,702,847, which provide background material for phase shift mask manufacturing. Finally, integrated circuits are manufactured using the resulting phase shift masks (step 310 ).
Overall, the embodiments described provide a solution for applying phase shift masks extensively in integrated circuit layouts. This provides for shrinking entire layouts or significant portions of layouts. The process involves first identifying features using a computer program to define any features that have a dimension which is smaller than a specified minimum dimension. Also, the process is applied to identify spaces between features which are smaller than a minimum dimension. The minimum dimension for spacing may be different than the minimum dimension for structures. After detection of features smaller than a minimum dimension, phase shift regions are assigned. Non-printing phase shift regions can be used for providing greater contrast in narrow isolated spaces. Inside corner extensions to block phase conflicts are added where necessary. Complementary trim masks are generated using established techniques. Finally, optical proximity correction modeling is used to optimize the shapes being implemented.
Embodiments of the invention also provides techniques for applying phase shifting to specific shapes, such as “T” shapes, “Y” shapes, “U” shapes and “double T” shapes.
Optical proximity correction can be applied to the resulting phase shifted layouts. Serifs can be added to corners, line sizes can be adjusted, hammer heads can be added, phase shift areas can be sized, and assist opaque bars may be added to phase shift areas, using optical proximity correction modeling techniques.
The foregoing description of various embodiments of the invention have been presented for purposes of illustration and description. The description is not intended to limit the invention to the precise forms disclosed. Many modifications and equivalent arrangements will be apparent to people skilled in the art.
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Techniques are provided for extending the use of phase shift techniques to implementation of masks used for complex layouts in the layers of integrated circuits, beyond selected critical dimension features such as transistor gates to which such structures have been limited in the past. The method includes identifying features for which phase shifting can be applied, automatically mapping the phase shifting regions for implementation of such features, resolving phase conflicts which might occur according to a given design rule, and application of sub-resolution assist features within phase shift regions and optical proximity correction features to phase shift regions. In one approach, phase shift regions are laid out so that they extend around corners in a feature, and in one or more identified corners having greater process latitude, the phase shift regions are divided and assigned opposite phases in the corner. In another approach, phase shift regions are laid out so that they do not extend through the corners, and then phase shift regions are merged in all but the identified corners. Both opaque field phase shift masks and complementary binary masks defining interconnect structures and other types of structures that are not defined using phase shifting, necessary for completion of the layout of the layer are produced.
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RELATED APPLICATIONS
This application is a §371 application from PCT/EP2013/075792 filed Dec. 6, 2013, which claims priority from French Patent Application No. 12 61804 filed Dec. 7, 2012, each of which is herein incorporated by reference in its entirety.
TECHNICAL FIELD
The present invention belongs to the field of well stimulation.
“Well stimulation” should be understood to mean the generation of a shockwave in a natural or drilling well. A well stimulation notably makes it possible to improve the production of a well for extracting an underground resource (oil, natural gas, water, etc.), to perform a seismological survey (for example by performing measurements by means of a sensor on the surface), to produce a fracturing of underground rock, etc.
STATE OF THE ART
In the field of well stimulation, it is known practice to use a tool of elongate form suitable for being inserted into a well obtained by drilling.
Such a tool comprises a first electrode and a second electrode, electrically insulated from one another, extending substantially from one end to the other of said tool. Said first and second electrodes of the tool form, at one end of said tool, a stimulation head. The stimulation head generally comprises a chamber intended to receive a fluid, into which said first and second electrodes emerge. Exemplary embodiments of such a tool are known:
from the U.S. Pat. No. 4,345,650, which describes a tool implemented to improve the production of an underground resource extraction well, from the international patent application WO9013830, which describes a tool implemented to perform a seismological survey, from the U.S. Pat. No. 4,479,680, which describes a tool implemented to produce a fracture in underground rock.
In well stimulation operations, the tool is inserted into said well with the stimulation head at the bottom, and is lowered to the point where the stimulation is to be performed. Once the stimulation point is reached, pulses of high intensity electrical current (possibly exceeding one hundred or so kilo-amps) are sent into the first electrode. A current arc is then formed, in the chamber of the stimulation head, between the first electrode and the second electrode (generally linked to the electrical ground). Said current arc makes it possible to form a shockwave which will stimulate the well. For example, such a shockwave can make it possible to unplug an extraction well.
Such a tool has a length that is generally between three and twenty meters, and is also very heavy, of the order of several hundreds of kilograms.
In order notably to facilitate the transport and handling thereof, such a tool generally takes the form of a plurality of sections intended to be joined end-to-end. Each section then comprises a first electrode and a second electrode electrically insulated from one another. The first electrode of the tool is thus formed by the connection of the first electrodes of said sections, and the second electrode of the tool is formed by the connection of the second electrodes of said sections.
The operations of joining said sections are, however, very difficult, notably because each section is very heavy.
OBJECT AND SUMMARY OF THE INVENTION
The main object of the present invention is to propose a solution which allows for a joining of the sections of a tool which is faster and simpler than the prior art solutions.
Furthermore, another objective of the present invention is to propose a solution which allows, in certain embodiments, a mechanical coupling between the sections which is both robust (resistant to a load of several hundreds of kilograms) and tight (resistant to a pressure of the order of several hundreds of bar at a temperature greater than one hundred or so degrees Celsius).
Furthermore, another objective of the present invention is to propose a solution which allows, in certain embodiments, an electrical coupling which is both robust (resistant to very high voltages—several tens of kilovolts—and very strong currents—several tens of kilo-amps) and effective in order to limit the electrical energy losses, the degradation of the electrical contacts and the electrical creeping by skin effect.
To this end, the invention relates to an electrical well stimulation device, said device comprising a plurality of sections, said sections being suitable for being joined end-to-end so as to form a tool comprising a first electrode formed by first electrodes of said sections and a second electrode formed by second electrodes of said sections, said second electrode being a peripheral electrode electrically insulated from said first electrode, and said first electrode and second electrode of the tool forming, at one of the ends of said tool, a stimulation head.
Furthermore, one end of a body of a first section comprises a peripheral ring which is rotationally mobile relative to said body of said first section and translationally immobile relative to said body of said first section, said peripheral ring comprising a threading suitable for cooperating with a threading of the second electrode of one end of a second section to join said second section to said first section.
Furthermore, if the threading of the peripheral ring is an external threading, then the second electrode of the first section comprises an extension between the peripheral ring and a termination of the end of said first section. If it is the threading of the second electrode of the second section which is an external threading, then the second electrode of the second section comprises an extension between the threading and a termination of the end of said second section. Finally, the first section and/or the second section comprise means, called “electrical contact means”, suitable for establishing an electrical contact between the second electrodes of the first section and the second section in a zone of contact of the extension, when the second section is joined onto the first section.
Because of the peripheral ring, it will be understood that it is possible to directly join the second section onto the first section, without requiring any intermediate part between said first and second sections.
The joining of the second section onto the first section will also be easier. In effect, once the threading of the second section is engaged with the threading of the peripheral ring, it will be sufficient, to produce the join, to rotate said peripheral ring while keeping the body of the second section rotationally immobile relative to the body of the first section.
Furthermore, the electrical contact means, arranged thus on the first section and/or the second section, make it possible to protect the faces, the seals and the threadings of the peripheral ring and of the second section. In effect, because of the electrical current levels considered, the circulation of the electrical current via the threadings could result in a seizing together, even a welding together of said threadings. It should be noted that the end of the section which bears the external threading must necessarily be engaged in the end of the other section, which then takes the form of a sleeve with an internal threading. Consequently, the extension of the second electrode of the section which bears the external threading is closer to the electrically insulating material, which separates said second electrode from the first electrode, than the second electrode of the other section. By skin effect, the electrical current has a tendency to circulate, in the second electrode of the tool, as close as possible to said electrically insulating material. It will therefore be understood that, by skin effect, the current will have a tendency to circulate mainly via the electrical contact means, such that the circulation of electrical current via the threadings will be limited.
In particular embodiments, the electrical well stimulation device comprises one or more of the following features, taken in isolation or in all technically possible combinations.
In a particular embodiment, the zone of contact is a peripheral zone of the extension.
Such arrangements make it possible to ensure a greater electrical contact surface area between the respective second electrodes of the first section and of the second section, while maximizing the distance between the electrical contact means and the first electrode.
In a particular embodiment, the extension comprises a peripheral seal arranged between the zone of contact of said extension and the external threading.
The use of a peripheral seal makes it possible to ensure the tightness of the mechanical coupling, and therefore to avoid the formation of current micro-arcs. Such an arrangement of the peripheral seal is also advantageous in that it makes it possible to protect said peripheral seal. In effect, as has been described for the threadings, the electrical current, by skin effect, will have a tendency to circulate mainly via the electrical contact means, such that the electrical current to which said peripheral seal could be subjected will be limited.
In a particular embodiment, the electrical contact means comprise an electrically conductive peripheral seal, a toroidal spring and/or an electrically conductive foil.
In a particular embodiment, the first section and the second section comprise respective means, called “rotation blocking means”, suitable for cooperating to rotationally immobilize a body of the second section relative to the body of the first section when said second section is joined onto said first section.
Such arrangements make it possible to further simplify the joining of the second section onto the first section. In effect, once the rotation blocking means of the second section have been engaged with the rotation blocking means of the first section, it will be sufficient, to produce the join, to rotate said peripheral ring.
In a particular embodiment, in which the device comprises at least three sections, the rotation blocking means of at least one section are not geometrically suited to cooperate with the rotation blocking means of at least one other section.
Such arrangements make it possible to avoid joining together sections which are not designed to be joined together. In other words, the rotation blocking means have, in this embodiment, an additional polarizing function.
In a particular embodiment, the peripheral ring and/or the body of the first section comprise an indentation forming a bearing surface suitable for cooperating with gripping means.
Such provisions make it possible to facilitate the handling of the peripheral ring and/or of the body of the first section, and therefore facilitate the joining of the second section onto the first section. For example, the indentation takes the form of a blind hole or of a flat.
In a particular embodiment, the first section comprises another peripheral ring that is rotationally mobile and translationally immobile relative to the body of said first section, said other peripheral ring comprising a threading suitable for cooperating with a threading of the second electrode of a third section to join said third section onto said first section.
DESCRIPTION OF THE FIGURES
The invention will be better understood on reading the following description, given as a nonlimiting example, and with reference to the figures which represent:
FIGS. 1, 2, and 3 : views before joining, after joining and in half-cross section after joining of an electrical well stimulation device,
FIGS. 4 and 5 : cross-sectional views of a first section and of a second section of an electrical well stimulation device according to a particular embodiment, before joining and after joining,
FIG. 6 : a perspective view of the first section of FIG. 4 ,
FIG. 7 : a cross-sectional view of a first section, of a second section and of a third section of an electrical stimulation device according to a particular embodiment, after joining, and
FIG. 8 : a cross-sectional view of a variant embodiment of the electrical stimulation device of FIG. 7 .
In these figures, identical references from one figure to another denote identical or analogous elements. For reasons of clarity, the elements represented are not to scale, unless stated otherwise.
DETAILED DESCRIPTION OF EMBODIMENTS
FIGS. 1, 2 and 3 schematically represent an electrical well stimulation device 10 .
Hereinafter in the description, the nonlimiting case of a stimulation device 10 for a well for extracting an underground resource, such as oil, natural gas, water, etc., will be assumed. However, as indicated previously, “well stimulation” should be understood generally to mean the generation of a shockwave in a natural or drilling well. Such a well stimulation can be implemented to improve the production of an underground resource extraction well, to perform a seismological survey, to produce a fracturing of underground rock, etc.
As illustrated by FIG. 1 , the electrical stimulation device 10 comprises a plurality of sections 11 adapted to be joined end-to-end.
FIG. 2 represents said electrical stimulation device 10 after said sections 11 have been joined so as to obtain a tool 10 a . FIG. 3 schematically represents a view in half-cross section of the tool 10 a of FIG. 2 .
It should be noted that “electrical stimulation device” denotes all of the sections 11 , whether joined or not, whereas “tool” denotes the object obtained by the joining of the sections 11 . Consequently, all the various sections 11 joined together will be able to be denoted hereinbelow in the description as “electrical stimulation device” or “tool”.
As illustrated by FIG. 3 , the tool 10 a comprises a first electrode 12 and a second electrode 13 . Said first electrode 12 and said second electrode 13 are electrically insulated from one another, throughout the body of the tool 10 a , by an electrically insulating layer 14 .
Said first and second electrodes 12 , 13 of the tool 10 a form, at one end of said tool 10 a , a stimulation head 15 , which is considered to be known to those skilled in the art.
Each section 11 comprises, for example, a part of the first electrode 12 , a part of the electrically insulating layer 14 and a part of the second electrode 13 of the tool 10 a.
Hereinafter in the description the nonlimiting case will be assumed in which the second electrode 13 is a peripheral electrode surrounding the electrically insulting layer 14 , said electrically insulating layer 14 surrounding the first electrode 12 which constitutes a central core of the tool 10 a.
It should be noted that the tool 10 a can comprise other elements not represented in FIGS. 1 to 3 . For example, one or more sections 11 of the tool 10 a may each comprise an electrical energy accumulator, an electrical protection device, etc.
The present invention relates to a refinement made to the joining means of at least two sections of the electrical stimulation device 10 , hereinafter respectively denoted first section 11 a and second section 11 b . It should be noted that this refinement is preferably implemented for the joining means of all the sections 11 of said electrical stimulation device 10 .
More particularly, one end of the body of the first section 11 a comprises a peripheral ring 16 . Said peripheral ring 16 is rotationally mobile relative to said body of said first section 11 a and is translationally immobile relative to said body of said first section 11 a . Furthermore, said peripheral ring 16 comprises a threading adapted to cooperate with a threading 133 of one end of a body of the second section 11 b to join said second section 11 b onto said first section 11 a.
FIGS. 4 and 5 schematically represent cross-sectional views of an exemplary embodiment of the first and second sections 11 a , 11 b , respectively before joining and after joining FIG. 6 schematically represents, in perspective, the first section 11 a of FIGS. 4 and 5 .
In the embodiment illustrated by FIGS. 4 and 5 , the threading of the peripheral ring 16 of the first section 11 a is an external threading, that is to say a threading arranged on the face of the peripheral ring 16 located on the side opposite the first electrode 12 forming the central core of said first section 11 a . Furthermore, the second electrode 13 of the first section 11 a comprises an extension 130 between the peripheral ring 16 and a termination 131 of the end of said first section 11 a.
As illustrated by FIG. 6 , the peripheral ring 16 is, for example, produced by means of two half-rings 16 a , 16 b joined between two peripheral abutments 132 a , 132 b of the second electrode 13 of the first section 11 a . The two half-rings 16 a , 16 b are joined together by any appropriate means, for example by means of screws 160 . Because the peripheral ring 16 is arranged between the two abutments 132 a , 132 b of the second electrode 13 of the first section 11 a , said peripheral ring 16 , while being rotationally mobile relative to said second electrode 13 of said first section 11 a , is translationally immobile relative to said second electrode 13 of said first section 11 a.
On the side of the second section 11 b , the second electrode 13 forms, at the end of said second section 11 b , a sleeve inside which the extension 130 of the second electrode 13 of the first section 11 a can penetrate. The threading 133 of the second section 11 b , produced on said sleeve, is an internal threading, that is to say a threading arranged on the face of said sleeve located on the side of the first electrode 12 forming the central core of the second section.
As illustrated by FIG. 5 , the internal threading 133 of the second electrode 13 of the second section 11 b is adapted to cooperate with the external threading of the peripheral ring 16 of the first section 11 a to join said second section 11 b onto said first section 11 a.
Because of the presence of the peripheral ring 16 , the joining of the second section 11 b onto the first section 11 a is simple to form. In effect, once the threading 133 of the second section 11 b has been engaged with the threading of the peripheral ring 16 , it will be sufficient, to produce the join, to rotate said peripheral ring 16 while keeping the body of the second section 11 b rotationally immobile relative to the body of the first section 11 a.
In order to further facilitate the joining of the second section 11 b onto the first section 11 a , the peripheral ring 16 and/or the body of the first section 11 a comprise an indentation forming a bearing surface suitable for cooperating with handling means.
In the example illustrated by FIG. 6 , the peripheral ring 16 and the body of the first section 11 a both comprise such indentations, in order to be able to immobilize the body of the first section 11 a when the peripheral ring 16 is rotated. More particularly, the peripheral ring 16 comprises, in the example illustrated by FIG. 6 , blind holes 161 suitable for cooperating with a pin wrench, and the body of the first section 11 a comprises flats 111 . According to other examples, there is nothing to preclude considering other forms of indentations.
In a preferred embodiment, the first section 11 a and the second section 11 b comprise respective means, called “rotation blocking means”, adapted to cooperate to rotationally immobilize the body of the second section 11 b relative to the body of the first section 11 a when joining said second section 11 b onto said first section 11 a.
The presence of such rotation blocking means makes it possible to further facilitate the joining of the second section 11 b onto the first section 11 a . In effect, once the rotation blocking means of the second section 11 b have been engaged with the rotation blocking means of the first section 11 a , it is sufficient, to produce the join, to rotate the peripheral ring 16 relative to the body of the first section 11 a.
In the example illustrated by FIG. 6 , the rotation blocking means are, for the first section 11 a , in the form of a key 110 . For the second section 11 b , said rotation blocking means are, for example, in the form of a groove (not represented in the figures) in which said key can slide while the second section 11 b is being joined onto the first section 11 a.
After joining, the end of the second electrode 13 of the second section 11 b surrounds the extension 130 of the second electrode 13 of the first section 11 a and a part of the peripheral ring 16 of said first section 11 a.
The electrical contact between the first electrode 12 of the first section 11 a and the first electrode 12 of the second section 11 b can be established by using any suitable means known to those skilled in the art. In the example illustrated by FIGS. 4 and 5 , the end of the first electrode 12 of the first section 11 a forms a sleeve 121 suitable for receiving an extension 120 of the first electrode 12 of the second section 11 b . The extension 120 of the first electrode 12 of the second section has no layer of electrically insulating material, and means are provided inside the sleeve 121 of the first electrode 12 of the first section 11 a for establishing the electrical contact between the first electrodes. In a preferred embodiment, illustrated by FIGS. 4 and 5 , the electrical contact means of the sleeve 121 are of multicontact type, for example a sleeve comprising blades with shape memory, a helical spring or even foils.
The electrical contact between the second electrode 13 of the first section 11 a and the second electrode 13 of the second section 11 b is, for example, established via the peripheral ring 16 , the latter being optionally made of an electrically conductive material.
In a preferred embodiment, illustrated by FIGS. 4 and 5 , the second electrode 13 of the first section 11 a comprises means called “electrical contact means”, suitable for establishing an electrical contact between the second electrode 13 of the second section in a contact zone of the extension 130 of the second electrode 13 of the first section 11 a.
In the example illustrated by FIGS. 4 and 5 , said electrical contact means are in the form of an electrically conductive peripheral seal 134 . There is nothing to preclude, according to other examples, considering other types of electrical contact means, for example an electrically conductive foil arranged at the periphery of the extension 130 of the second electrode 13 of the first section 11 a . Furthermore, it should be noted that the electrical contact means could be borne by the second electrode 13 of the second section 11 b , or even by both the first section 11 a and the second section 11 b.
By virtue of the electrical contact established at the extension 130 of the second electrode 13 , the electrical current, which by skin effect has a tendency to circulate in the second electrode 13 as close as possible to the electrically insulating layer 14 , will have a tendency to circumvent the peripheral ring 16 . In effect, by assuming that the electrical current circulates from the first electrode 12 of the first section 11 a to the first electrode 12 of the second section 11 b then returns by circulating from the second electrode 13 of the second section 11 b to the second electrode 13 of the first section 11 a , it can be seen that the shortest path allowing the electrical current to pass as close as possible to the electrically insulating layer 14 consists in passing through the contact zone of the extension 130 of the first section 11 a . That said, the electrical current will have a tendency to circumvent the peripheral ring 16 .
In the example illustrated by FIGS. 4 and 5 , the extension 130 of the second electrode 13 of the first section 11 a comprises two peripheral seals 135 . Advantageously, said peripheral seals 135 are arranged between the contact zone of said extension 130 and the peripheral ring 16 . In this way, as indicated previously, the electrical current will have a tendency to circumvent said peripheral seals 135 , and the risks of the latter being damaged by the circulation of the electrical current are reduced.
FIG. 7 schematically represents a variant embodiment of the first section 11 a illustrated by FIGS. 4 to 6 . In this variant embodiment, said first section 11 a , (represented with grey shading in FIG. 7 ) comprises two peripheral rings arranged at opposite ends of said first section 11 a.
Thus, the first section 11 a comprises, at an end opposite the end of the peripheral ring 16 described with reference to FIGS. 4 to 6 , another peripheral ring 17 . Said peripheral ring 17 is rotationally mobile and translationally immobile relative to the body of the first section 11 a . Furthermore, said peripheral ring 17 comprises a threading suitable for cooperating with a threading of one end of a body of a third section 11 c to join said third section 11 c onto said first section 11 a.
In the embodiment illustrated by FIG. 7 , the threading of the peripheral ring 17 of the first section 11 a is an external threading. Furthermore, the second electrode 13 of the first section 11 a comprises an extension 136 between the peripheral ring 17 and a termination 137 of the end of said first section 11 a.
On the side of the third section 11 c , the second electrode 13 forms, at the end of said third section 11 c , a sleeve into which the extension 136 of the second electrode 13 of the first section 11 a can penetrate. The threading of the third section 11 c , produced on the second electrode at said sleeve, is an internal threading, that is to say a threading arranged on the face of said sleeve located on the side of the first electrode 12 forming the central core of the third section 11 c.
As illustrated by FIG. 7 , the internal threading of the second electrode 13 of the third section 11 c is adapted to cooperate with the external threading of the peripheral ring 17 of the first section 11 a to join said third section 11 c onto said first section 11 a.
Everything that has been described above concerning the peripheral ring 16 and the extension 130 can also be applied to the peripheral ring 17 and to the extension 136 of the second electrode 13 of the first section 11 a.
In the nonlimiting example illustrated by FIG. 7 , the first section 11 a has no electrically insulating layer 14 and no first electrode 12 . In effect, the respective electrically insulating layers 14 and first electrodes 12 of the second section 11 b and of the third section 11 c extend inside the first section 11 a , and cooperate therein so as to ensure both the electrical continuity of the first electrode 12 and the electrical insulation between said first electrode 12 of the tool 10 a and the second electrode 13 of the first section 11 a.
There is nothing to preclude, according to other examples, having a first section 11 a comprising a part of the electrically insulating layer 14 and/or a part of the first electrode 12 .
FIG. 8 schematically represents a variant embodiment of the first section 11 a of FIG. 7 , in which said first section 11 a comprises a part of the electrically insulating layer 14 and a part of the first electrode 12 of the tool 10 a . Advantageously, the first electrode 12 of the first section 11 a forms two opposite sleeves, respectively 121 and 123 , adapted to receive respective extensions 120 and 122 of the first electrode of the second section 11 b and of the first electrode of the third section 11 c.
Such arrangements are advantageous in that they make it possible to have identical ends for the second section 11 b and the third section 11 c , which facilitates their production and their internal arrangement.
More generally, it should be noted that the embodiments considered above have been described as nonlimiting examples, and that other variants can consequently be envisaged.
Notably, the electrical stimulation device 10 has been described by considering a peripheral ring 16 comprising an external threading. There is nothing to preclude, according to other examples, considering a peripheral ring 16 comprising an internal threading adapted to cooperate with an external threading produced on the periphery of the body of the second section 11 b . The peripheral ring 16 then takes the form of a sleeve into which the end of the second section 11 b can penetrate. In the case, described with reference to FIGS. 7 and 8 , of a first section 11 a comprising two peripheral rings 16 , 17 , one and/or the other of said two peripheral rings can comprise an internal threading adapted to cooperate with an external threading produced on the periphery of the second electrode 13 of another section.
Furthermore, the electrical stimulation device 10 may comprise only two sections 11 , but it may also comprise more thereof. In a preferred embodiment, when said electrical stimulation device 10 comprises at least three sections, the rotation blocking means of at least one section are not geometrically adapted to cooperate with the rotation blocking means of at least one other section.
Such provisions make it possible to use said rotation blocking means as polarizers. Such a polarizing function can prove advantageous notably in the case where the sections comprise electrical energy accumulators and/or electrical protection devices. In such a case, the position of the sections relative to one another may prove essential, and will be able to be ensured by virtue of the rotation blocking means also offering a polarizing function.
In the case where said rotation blocking means are in the form of keys and associated grooves, the polarizing function will be able to be obtained by considering keys in different numbers, of different dimensions, of different positions, etc., from one section to another.
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An electrical device for well stimulation comprising a plurality of sections configured to be assembled, end to end, to form a tool. The tool comprises first and second electrodes. The second electrode is an electrically insulated peripheral electrode of the first electrode. The first and second electrodes of the tool forming, at one of the ends of the tool, a stimulation head. Additionally, one end of a body of a first section comprises a peripheral ring that is rotatably movable and translatably immobile relative to the body of the first section. The peripheral ring comprises a thread configured to engage with a thread of the second electrode of one end of a second section.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 11/257,726, filed Oct. 25, 2005, now U.S. Pat. No. 7,752,821 which claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/622,418, filed Oct. 27, 2004, both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Suspended ceilings of various shapes and sizes are being increasingly used in order to add interest to various public spaces, such as retail outlets, contemporary office lobbies and halls, entertainment establishments, and the like. This has lead to the creation of suspended ceiling systems for defining spaces in which the ceiling panels lie in more than one plane, such as in vaults, transitions between different ceiling heights, islands, and waves.
One problem with such non-conventional ceiling systems is the difficulty of installing the suspending grid so that the runners for supporting the associated ceiling panels are maintained in accurate alignment. In particular, this difficulty has lead to increased time and cost for the assembly of such suspended ceiling systems.
Accordingly, by way of the invention described herein, a suspended ceiling system is provided that is particularly suited for providing a grid system that is curved in vertical plane, provides for accurate spacing and alignment of the grid elements, and facilitates quick assembly and installation of the assembled grid system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a grid system for a curved suspended ceiling in accordance with the present invention.
FIG. 2 is a perspective view of a portion of a primary carrier in accordance with the present invention.
FIG. 3 is a perspective view of a splice for connecting primary carriers in accordance with the present invention.
FIG. 4 is a perspective view showing the splice of FIG. 3 joining two primary carriers in accordance with present invention.
FIG. 5 is a perspective view of a portion of the grid system according to the present invention showing a clip for securing a primary carrier to a main runner.
FIG. 6 is an enlarged perspective view of the clip for securing the primary carrier to the main runner.
FIG. 7 is a perspective view of a portion of the grid assembly showing a connection of a primary carrier to a perimeter trim piece.
FIG. 8 is an enlarged perspective view of a clip for securing the primary carrier to the perimeter trim piece.
FIG. 9 is a perspective view of a portion of the grid system of the present invention showing the connection of a main runner to a trim piece.
FIG. 10 is an enlarged perspective view of a clip for securing a main runner to a trim piece.
FIG. 11 is a perspective view of a portion of the grid system showing two pieces of trim connected to each other by means of a splice clip.
FIG. 12 is an enlarged exploded perspective view of the splice clip for connecting two trim pieces together.
FIG. 13 is a perspective view of a hanger clip for securing the hanger wire to the primary carrier.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention comprises an assembly particularly suited for a curved suspended ceiling grid. With reference to FIG. 1 , the system, generally designated 10 , includes main runners or tees 12 which are curved in a vertical plane to support either flexible panels 13 or preformed, lay-in panels (not shown), the latter requiring cross-tees between adjacent main tees. The curve may be either concave or convex with respect to the exposed side of the ceiling system. Edge or perimeter trim pieces 14 (which may be either curved or straight, as required to correspond to the shape of the main runners 12 ), having opposed interior slots define the perimeter of the suspended ceiling. Corner clips are used to secure the perimeter trim pieces to each other. However, the perimeter trim may be omitted, if desired, without departing from the invention. Each of the main runners, trim pieces and corner clips have previously been available from Chicago Metallic Corporation, assignee of the present application, under the “CurvGrid” and “CurvTrim” trademarks.
In keeping with one aspect of the present invention, one or more primary or tube carriers, generally designated 20 , is utilized to interconnect the main runners 10 and provide a unitized, rigid grid system. Each primary carrier 20 preferably extends substantially the full width of the suspended ceiling and is preferably spaced no more than about 48 inches from the adjacent primary carrier. The primary carrier 20 may be of any length that is practical given both manufacturing and shipping constraints, and typically may be as long as 16 feet in length.
The primary carrier 20 preferably has a circular cross-section, with an outside diameter of approximately 1.25 inches, although other cross-sectional shapes and sizes may be utilized without departing from the invention. The primary carrier has a notch or slot 22 for each of the main runners supported by the tube carrier 20 , the notch 22 being sized in width and depth to receive the bulb of the main runner. In a preferred embodiment, the tube carrier 20 is roll-formed from 0.028 inch thick steel with a lock seam 20 a . The notches 22 aid in the installation of the ceiling by maintaining on-center spacing of the main runners 10 without the use of cross tees.
If the width of the curved ceiling is greater than the length of a single primary carrier 20 , adjacent primary carriers can be staggered so that together they extend substantially the full width of the ceiling. More preferably, one or more primary carriers may be joined together end-to-end to obtain the desired length by using a splice connector 21 , as shown in FIG. 3 . With reference to FIGS. 3 and 4 , approximately half the length of the splice connector 21 is received in the interior of each of the two primary carriers joined thereby. The primary carriers and splice connector may be positively secured to one another by fasteners, such as screws 21 a . The primary carriers 20 may also include an inwardly-projecting embossment spaced from their ends that serve as a stop to prevent over insertion of the splice clip 21 into the primary carriers 20 .
The splice connector 21 may be made from electrical metallic tube (commonly referred to as “EMT”) having an outside diameter and cross-sectional shape that is complementary to the inside diameter and cross-sectional shape of the primary carrier 20 . The splice connector 21 has a slot 21 b along its length to allow it to mate with a lock seam 20 a in the tube carrier 20 , thus preventing rotation of the splice clip 21 and maintaining the angular alignment of the splice clip relative to the primary carriers 20 .
With reference to FIGS. 5 and 6 , clips 24 with cut-outs 26 are provided that fit over the top of the primary carrier 20 to secure the main runners 10 to the primary carrier 20 . The cut-outs 26 are generally complementary in shape to the primary carrier and thus, in the illustrated embodiment, are generally an inverted U-shape. The clip 24 is provided with opposed faces 28 , the bottom edges 30 of which terminate in inwardly-pointing lips that are adapted to support the bottom surface of the bulb of the main runner. Alternatively, the clip 24 may be formed with inwardly-pointing tabs (not shown) for the same purpose. The clip 24 has aligned holes 34 in its opposed faces 28 for receiving screws 36 that draw together the lips or tabs on the clips so that they securely support the bulb of the main runner 10 . The clip 24 preferably includes stand offs 37 that are received on the shanks of the screws 36 and are sized in length to prevent over-tightening for the screws.
One advantage accruing to the present invention is that the primary carrier provides a cantilevered attachment point for the perimeter trim, allowing the hanger wire for suspending the grid to stand off from the end of the carrier tube, thus shielding the hanger wire from view. To this end, a perimeter clip 38 for securing the primary carrier 20 to a trim piece 14 is shown, best seen in FIGS. 7 and 8 . The primary carrier perimeter clip 38 comprises three L-shaped segments 40 , 42 , 44 , joined together on one leg of the L, that are bendable into a generally U-shaped member. When bent, the corner 46 of one leg of each of the outer L-shaped segments is partially received in the upper of two opposed slots on the trim pieces, while the edge 48 of the corresponding leg of the middle L-shaped segment is received in the lower of the two opposed slots. The other leg of each L-shaped segment extends generally perpendicularly from the trim piece 14 to support the primary carrier 20 . Each of the two outer arms that support the primary carrier 20 includes an aperture 50 adapted to receive a screw or other fastener for positively securing the clip 38 to the primary carrier 20 .
With reference to FIGS. 9 and 10 , a second perimeter clip 52 is shown for securing the main runners 10 to a perimeter trim piece. (Such clips may also be used to secure cross tees, if used, to a perimeter trim piece.) The main runner perimeter clip 52 is also generally L-shaped, with one leg of the L having opposed edges that are received in the opposed slots of the straight trim piece 14 . This leg preferably includes a tapped hole 54 for receiving a set screw 56 that may be tightened against the web of the trim piece 14 to lock the perimeter clip thereto. Preferably, this leg has a curved edge 58 that permits the clip 52 to be positioned on the trim piece and then simply twisted to cause its edges to locate in the opposed slots in the trim piece. The other leg is adapted to lie along the web of the main runner 10 , and includes an ear 60 which can be folded through a slot in the main runner 12 to lock the main runner thereto.
Turning to FIGS. 11 and 12 , a splice clip 62 is provided for joining lengths of perimeter trim 14 to each other. The splice clip 62 has two parts 64 , 66 . The first part 64 has opposed edges 68 which are received in the opposed slots on the trim piece. The second piece 66 overlies the first piece 64 to clamp the lips that define the slots in the trim piece between the two pieces of the splice clip 62 . The second piece 66 has four corners 70 that are bent downwardly to engage the lips of the channels that receive the first piece 64 . The two pieces 64 , 66 of the splice clip 62 are attached together by a pair of screws 72 .
The grid system of the present invention is suspended by hanger wires secured to the primary carriers, rather than to the main runners. This minimizes the number of hanger wires required to support the system. For smaller-sized ceilings, the curved grid system as described can be easily and accurately assembled on the floor of the space in which it is to be installed, and then raised as a unit in order to secure the hanger wires to the tube carriers. Otherwise, the primary carriers 20 are first hung, and the remaining components of the grid system then secured thereto. With reference to FIGS. 1 , 4 and 13 , a plurality of hanger clips 74 is provided that secure the hanger wire to the primary carriers 20 . The hanger clips 74 have a strap portion 76 that is partially covered with a resilient, rubber-like sleeve 78 that conforms to the shape of the surface of the tube carrier 20 contacted by it. The hanger clips 74 have a slightly oversized opening with respect to the diameter of the primary carrier in order to permit a minor amount of relative rotation between the hanger clip and the primary carrier. This ability to rotate with respect to each other allows a certain amount of “self centering” of the tube carrier with respect to the hanger wire, so that the hanger wire extends generally perpendicularly from the primary carrier. This subjects the hanger wire to less stress at the point at which it is secured to the hanger clip.
Thus, a suspended ceiling system particularly suited for a curved grid has been provided that facilitates accurate and quick assembly with enhanced structural rigidity. While the invention has been described in terms of a preferred embodiment, it is not intended to be limited to the same. Indeed, variations are contemplated that are within the ordinary skill in the art. For example, while the system has been described in connection with curved main runners, the primary carriers could also be used with a more conventional planar grid system. In addition, while cross tees are not required for structural reasons, they may still be utilized with the present invention for aesthetic reasons if, e.g., the lay-in panels have an edge reveal. Also, the primary carrier may have a cross-section other than generally circular without departing from the invention.
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A grid system is provided that is particularly suited for the suspended ceiling system that varies in the vertical plane. An elongated carrier tube is provided the spans substantially the width of the grid system that has a slot therein adapted to receive the strengthening bulb of a main runner. A clip is provided that seats on the carrier tube that has opposed faces for capturing the bulb of the runner, so as to secure the runner to the tube carrier.
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RELATED APPLICATIONS
[0001] This application is a continuation in part of related U.S. patent application Ser. No. 09/950,109, now pending, which is a continuation in part of U.S. patent application Ser. No. 09/438,935, now pending, both of which are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to expandable shoes that may be adjusted longitudinally.
[0004] 2. Discussion of Related Art
[0005] Some attempts have been made to provide expandable shoes, which can purportedly withstand day-to-day use. U.S. Pat. No. 3,389,481, for example, discloses a shoe in which a two plate assembly is disposed between an inner and a disjointed outer sole, having overlapping front and back portions. One of the plates includes a spring tongue, and the other plate includes two apertures to receive the spring tongue, each aperture corresponding to a shoe size. To adjust the shoe size, a screw which extends through the heel and into the disjointed soles is removed. The shoe may then be pulled apart allowing the disjointed sole to separate until the spring tongue engages the next aperture. Thus the shoe size may be lengthened by one size, but apparently the size cannot be controlled finely or reduced. The shoe includes two crinkled leather portions 34 , one on each side of the shoe, to facilitate expansion of the shoe.
[0006] WO 01/33986 describes an expandable shoe. The expandable shoe includes an outer shell having a front and a rear outer assembly each attached to a flexible, expandable segment. An adjustable inner assembly is disposed within the outer shell and includes a control mechanism, accessible from the outer shell, that may be urged from a lock state into a state in which the inner assembly and outer shell may be adjusted. A visualization window provides a view port to the inner assembly.
[0007] Though WO 01/33986 details a desirable expandable shoe design, certain improvements thereto have been discovered to improve ergonomics, torsional rigidity, handling, and the construction of the shoe.
SUMMARY
[0008] Under one aspect of the invention, an expandable shoe is provided which includes a front outer assembly, and a rear outer assembly. An expandable segment attaches to the front and rear outer assemblies to define a shoe outer shell and the expandable segment extends at least partially along each side of the outer shell and transversely across the bottom of the outer shell. An adjustable inner assembly is disposed within the outer shell and has a first board portion and a second board portion in overlapping engagement with each other. The inner assembly also includes a control to adjust the position of the first board portion relative to the second board portion and to thereby adjust a dimension of the inner assembly and thereby a corresponding dimension of the shoe.
[0009] Under another aspect of the invention, the control includes a locking mechanism shaped to engage and hold one of the first and second board portions, a biasing mechanism to bias the locking mechanism into engagement with one of the first and second board portions; and an urging member having a proximal portion external of the shoe outer shell and positioned and movable transversely to a longitudinal direction of the shoe and in transverse alignment with the locking mechanism.
[0010] Under another aspect of the invention, one of the first and second board portions include transversely extending teeth, and the locking mechanism includes transversely extending teeth and the urging member include a rod portion having at least two diameters. The locking mechanism includes an aperture in alignment with the rod portion and the cross section of the aperture is larger than the smaller of the at least two diameters but smaller than the large of the at least two diameters. When the urging member is moved, the rod portion contacts and moves the locking mechanism with the larger of the two diameters.
[0011] Under another aspect of the invention, one of the first and second board portions includes an upward-facing cavity containing the control. The opening to the cavity is covered by the other of the first and second board portions when the first and second board portions overlap.
[0012] Under another aspect of the invention, one of the first and second board portions includes at least one groove extending longitudinally and the other of the first and second board portions includes a corresponding rail in alignment with the groove. The rail is positioned within the groove as the first and second board portions overlap.
[0013] Under another aspect of the invention, one of the first and second board portions has at least one projection which extends into a cavity in the sole.
[0014] Under another aspect of the invention, at least one of the first and second board portions includes a lattice support structure.
[0015] Under another aspect of the invention, one of the first and second board portions includes a set of notches and the locking mechanism has a surface feature to contact a notch in the set of notches to resist relative movement of the first and second members in relation to shoe size and provide ergonomic sensation.
[0016] Under another aspect of the invention, a visualization window provides a view to the inner assembly. The inner assembly may include size markings or other indicia representative of a shoe adjustment, and these markings may be placed on the inner assembly to allow them to be visible through the visualization window.
[0017] Under another aspect of the invention, a light source may be provided in the cavity to illuminate the visualization window.
BRIEF DESCRIPTION OF THE DRAWING
[0018] In the Drawing,
[0019] [0019]FIGS. 1 and 2 show shoe designs according to certain embodiments of the invention;
[0020] [0020]FIG. 3 is a longitudinal cross sectional view of a shoe according to certain embodiments of the invention;
[0021] FIGS. 4 A-B are exploded views of expandable last boards according to certain embodiments of the invention;
[0022] FIGS. 5 A-C show features of expandable last boards according to certain embodiments of the invention;
[0023] [0023]FIGS. 6 and 7 show an exemplary control mechanism in two states.
[0024] [0024]FIG. 8A shows a perspective view of last boards according to one embodiment of the invention.
[0025] [0025]FIG. 8B shows a bottom cross section view according to one embodiment of the invention.
[0026] FIGS. 9 - 16 , 18 and 20 show bottom views according to certain embodiments of the invention.
[0027] [0027]FIG. 17 shows a rear view of a shoe according to one embodiment of the invention.
[0028] [0028]FIG. 19 shows a side view of a shoe according to one embodiment of the invention.
DETAILED DESCRIPTION
[0029] Certain embodiments of the present invention provide improvements to the ergonomics, torsional rigidity, handling, and construction of the shoe designs disclosed in WO 01/33986. That reference in conjunction with U.S. patent application Ser. No. 09/438,935 is hereby incorporated by reference in its entirety.
[0030] [0030]FIGS. 1 and 2 show two shoe designs under certain embodiments of the invention. With reference to FIG. 1, shoe 10 includes a front outer sole 12 and a front upper 18 to form a front outer assembly 13 , and a rear outer sole 16 and a rear upper 20 to form a rear outer assembly 17 . The front outer assembly 13 is attached to one edge 15 B of a bellows segment 14 , and the rear outer assembly 17 is attached to a second edge 15 A, in each case using conventional techniques, such as by using stitching to the uppers 18 , 20 and glue along the outer soles 12 , 16 . The combination of front outer assembly 13 , rear outer assembly 17 , and bellows segment 14 forms an outer shell 21 .
[0031] An alternative shoe 20 is illustrated in FIG. 2. One principal difference in shoe 20 relative to shoe 10 is the bellows 22 of shoe 20 does not completely surround the shoe, whereas bellows 14 of shoe 10 is a unitary bellows enveloping the circumference of the shoe.
[0032] Similarly to that described in U.S. patent application Ser. No. 09/438,935, an adjustable inner sole assembly is placed within outer shell 21 . An externally-accessible manual control is urged via cap 24 and is used to place the inner sole assembly in a state in which it may be adjusted. When the control is in its natural state (i.e., when it is not urged transversely) it is in a lock state to hold the shoe adjustment fixed.
[0033] [0033]FIG. 3 is a longitudinal cross-sectional view of an exemplary shoe 10 . As can be seen in this view, an adjustable inner assembly 30 is positioned within the outer shell 21 and is generally formed from two pieces 31 , 32 which are shaped to engage and move relative to one another in overlapping relationship. The overlapping and engaging inner assembly 30 provides a relatively rigid last board for desirable foot support. In this embodiment, rear piece 31 is partially positioned within a heel section of the shoe 10 and includes the control mechanism 41 , discussed below, which allow the shoe to be adjusted in size. The shoe includes a two piece inner last board 33 , 34 . This two piece inner last is made from materials, e.g., cloth, used for conventional last boards and is attached or sewn to the outer shell. Over the inner last is a two piece inner sole 36 and 37 made from conventional materials, e.g., foam, and shaped to overlap one another so that the pieces slide as the shoe size is adjusted.
[0034] [0034]FIG. 4A is an exploded view of one embodiment of the inner assembly 30 in relation to rear outer assembly 17 . The inner assembly 30 includes front last board piece 31 and rear last board piece 32 positioned in overlapping, slidable and engaging relationship, as will be described more fully below in connection with the description of other figures. The front piece includes a downward facing cavity 40 (shown better in other figures) into which a control mechanism 41 is positioned. Plate 46 is mounted on the front piece 31 over the cavity 40 and encapsulates the control mechanism within the cavity, protecting it from glue and other substances used in the construction of the entire shoe. On the bottom surface of plate 46 , shoe size indicia or adjustment indicia may be printed, engraved, labeled, or the like. The heel portion of the inner assembly 30 is positioned within a heel support 47 . A plate 48 having magnification window 49 is fixed to the rear piece 32 by protrusions or the like to align the window 49 with the indicia on the bottom surface of plate 46 . Cap 24 is fit over the proximal end of pin 45 and the entire assembly is fit within rear outer assembly 17 and the other components of the outer shell 21 .
[0035] [0035]FIG. 4B is an exploded view of another embodiment of the inner assembly 30 . In this embodiment, the front piece 31 has an upward facing cavity (not shown) into which the control mechanism is placed. The bottom surface of the cavity is integrated into the front piece 31 (as opposed to an attached plate 46 ), and the control mechanism is encapsulated by the rear piece 32 being positioned over the opening of the cavity. The bottom surface of the front piece, like the plate 46 of the prior embodiment, includes shoe size indicia or adjustment. The bottom surface 34 of the rear piece 32 has a cutout (not shown), through which the indicia may be observed. In particular, a magnification window 49 ′ is attached to the bottom surface 34 of the rear piece 32 in alignment with the cutout and through which the indicia may be viewed. To illustrate the wide applicability of the design, this figure shows the inner assembly being used with a midsole 17 ′ having an attached outer sole 17 ″.
[0036] With reference to FIGS. 3, 4A, 6 , and 7 , the control mechanism 41 has a natural, locked state in which a toothed member 42 engages teeth 62 integrated with or attached to the front piece. The locked state prevents the front and rear pieces 31 and 32 from being moved longitudinally relative to one another. By sufficiently pushing pin 45 of the control mechanism 41 in a transverse direction relative to the last board's longitudinal direction, the last board may be placed in an unlocked state in which the toothed member 42 disengages the integrated or fixed tooth segment. Consequently, the front piece 31 may be moved longitudinally relative to the rear piece 32 . The longitudinal movement is constrained by the extent of the longitudinal apertures 35 , one of two of which is shown in FIG. 3. As the front and rear pieces 31 , 32 are moved relative to one another, different indicia will align with the magnification window 49 , 49 ′.
[0037] The control mechanism 41 of either embodiment includes a toothed member 42 , a biasing spring 43 , a support guide 44 , and an urging pin 45 . The teeth of the toothed member 42 are shaped and spaced to engage with teeth 62 (shown in FIG. 6 and 7 ) integrated into or fixed to a wall 64 of the cavity 40 facing the teeth of the toothed member 42 . FIG. 6 shows the support guide 44 and spring 43 biasing the toothed member 42 into engagement with the integrated teeth. This “locked” state prevents the front piece from moving longitudinally relative to the rear piece 32 .
[0038] Pin 45 has a first section 45 A of a relatively larger diameter and a second section 45 B of a relatively smaller diameter. The pin 45 is sized to fit through aperture 33 in rear section 32 , through longitudinal slot 35 (shown in FIG. 3), through the control mechanism 41 , and into another aperture corresponding to aperture 33 but on the hidden side of the rear section 32 . More specifically, the larger diameter section 45 A fits through aperture 33 but is too large to fit through the central aperture 42 A of toothed member 42 . The smaller diameter section 45 B, however, is small enough to fit through the central aperture 42 A of member 42 and aperture 44 A of support 44 . The support 44 includes a circular protrusion 44 C which defines the aperture 44 A and which fits into the aperture corresponding to the aperture 33 but on the hidden side. Thus, as the pin 45 is pushed through the aperture 33 , the larger diameter section 45 A eventually contacts toothed member 42 but does not pass through it. Continued pushing of pin 45 will thus cause the toothed member 42 to move transversely and compress spring 43 against support 44 . Circular recess 44 B of support 44 helps keeps the components in secure alignment. Sufficient pushing of the pin 45 will cause the teeth of member 42 to clear and disengage the integrated teeth of front piece 31 , as shown in FIG. 7. This “adjustment” state allows the front piece 31 to be moved longitudinally relative to the rear piece 32 , while the teeth are so disengaged. The number of teeth and the spacing in between teeth may be made to index to known adjustments. For example, the amount of teeth and spacing may be made to correspond to a range of sizes 13 to 1 and allow half size increments 13, 13.5, 1.
[0039] FIGS. 6 and further illustrates an end cap 75 . The end cap has a cylindrical protrusion 77 to fit into aperture-defining portion 76 and defines an aperture 78 to receive a distal end of pin 45 . The cap further encapsulates the control mechanism protecting it from glue and other debris during manufacturing and use of the shoe.
[0040] Though the control mechanism and states are shown and described with reference to the embodiment of FIG. 4A, the operation and components are the same for the embodiment of FIG. 4B. The embodiment of FIG. 4B requires the control mechanism (except for pin 45 ) to be assembled within the cavity of the front piece 31 before the front piece is arranged with the rear piece but it has the advantage of improved encapsulation and protection from glue used in shoe assembly.
[0041] FIGS. 5 A-C show certain improvements to the design of the front and rear pieces relative to embodiments shown in WO 01/33986. The rear piece 32 is generally shaped like the rear piece disclosed in WO 01/33986 having slots 51 and 52 to accept the wings 53 and 54 of the front piece 31 so that the front piece may slide within rear piece 32 in an overlapping relationship. When fully contracted curved sections 55 and 56 of the front piece 31 contact curved walls 57 and 58 of the rear piece 32 . Unlike the design shown in WO 01/33986, the rear piece 32 includes two rails 59 and 60 protruding up from the major surface of the rear piece 32 , and the front piece includes two slots 61 and 62 shaped to receive these rails. Because the rails protrude from the major surface they help inhibit transverse sliding of the front and rear pieces and improve the torsional rigidity of the last board 30 .
[0042] As shown in FIGS. 6 - 8 , the cavity 40 has a set of notches 80 to provide ergonomic feedback (in the form of resistance and/or clicking) to the user when he or she is adjusting the shoe size. The notches are positioned to correspond to shoe size adjustments. As the front piece 31 and rear piece 32 are moved relative to one another, a surface of portion 81 of the control mechanism 41 contacts a notch, and thus provides resistance to the user pushing or pulling the two pieces 31 , 32 together or apart, when the teeth 64 do not align with the teeth of toothed member 42 . When the teeth 64 and the toothed member 42 align, a surface of portion 81 of the control mechanism will be positioned in a valley or recess of the set of notches 80 and thus provide no resistance to the user, giving the user the tactile sensation of no resistance and signaling that the shoe size adjustment is in alignment. In addition, the surface portion 81 of the control mechanism causes a clicking sound as it completes the move from the notch into the valley or recess, further signaling to the user that the shoe size adjustment is in alignment.
[0043] [0043]FIG. 5C shows the bottom surface of front piece 31 and illustrates the lattice-shaped support structure 66 integrated into the front piece. Though other arrangements may be substituted, the structure 66 provides improved torsional rigidity in the midsole area while allowing some of the material of the front piece 31 to be removed and to thus reduce weight.
[0044] FIGS. 9 - 16 show additional embodiments of the invention in which the front piece 31 has one or more longitudinally extending projections which extend into a cavity (or cavities) in the sole 82 . These projections help inhibit transverse sliding of the front piece 31 and rear piece 32 and improve the torsional rigidity of the last board.
[0045] In the embodiment shown in FIGS. 9 and 10, three cylindrical rods 88 , 90 and 92 extend from the front piece 31 and are positioned in corresponding cylindrical cavities 94 , 96 and 98 in the sole 82 . As the front piece 31 is moved relative to the rear piece 32 , the cylindrical rods 88 , 90 and 92 move further into the cavities 94 , 96 and 98 . In the embodiment shown in FIGS. 11 and 12, two cylindrical rods 100 and 102 extend from the front piece 31 and are positioned in corresponding cylindrical cavities 104 and 106 in the sole 82 . In the embodiment shown in FIGS. 13 and 14, a longitudinally extending rectangular projection 86 extends from the front piece 31 and is positioned in a rectangular cavity 84 in the sole 82 . In the embodiment shown in FIGS. 15 and 16, a triangular projection 112 extends from the front piece 31 and is positioned in a triangular cavity 114 in the sole 82 . A cross section of the triangular projection is shown in FIG. 16A.
[0046] It is understood that projections and cavities of other shapes may be used to provide the desired torsional stability, and that the number of such projections and corresponding cavities may also be varied.
[0047] In the embodiment shown in FIGS. 17 and 18, a visualization window 116 is provided in a wall of the sole 117 in the heel portion of the shoe to provide a view to the inner assembly. As shown in FIG. 18, indicia 118 , such as shoe size or adjustment indicia, is applied to the front board portion 31 so that as the front board portion 31 is moved relative to the rear board portion 32 , the indicia travels up around the heel portion of the front board portion 31 , and the shoe size or adjustment indicia is visible through the visualization window 116 .
[0048] In the embodiment shown in FIGS. 19 and 20, the visualization window 116 is located in a side wall 120 of the sole of the shoe. As shown in FIG. 20, shoe size or adjustment indicia is applied to a side portion 122 of the front board portion 31 so that as the front board portion 31 is moved relative to the rear board portion 32 , the shoe size or adjustment indicia is visible through the visualization window 116 .
[0049] In the embodiment shown in FIG. 18, the visualization window may be illuminated. The cavity 40 includes a light source 124 , electronic connectors 126 connected to a power source 127 and a clear lens 128 to transmit light from the light source 116 to the visualization window 116 . The light source 124 is activated when the control mechanism 41 in the “adjustment” state as described above (i.e., where the front piece 31 is allowed to move longitudinally relative to the rear piece 32 , while the teeth of member 42 are disengaged from the integrated teeth of front piece 31 ). The light source is de-activated when the control mechanism is in a locked state (i.e., when the teeth of member 42 are engaged with the integrated teeth of front piece 31 . One way to activate the light source is to put contacts on the control mechanism, so that as the control mechanism is depressed, a circuit is formed to activate the light source so that light is transmitted from the light source to the visualization window.
[0050] The shoe designs of FIGS. 1 and 2 are exemplary. The principles of the invention may be manifested in embodiments including running shoes, biking shoes, ski boots, dress shoes, snow boarding boots, sandals and the like. Depending on the shoe type, the inner assembly may be in the form of a last board, or a combination of a last board and a midsole, or a midsole. Likewise, depending on the shoe type, the materials used will be selected to provide a desired amount of flexibility or rigidity. Moreover, depending on the shoe design the outer shell may differ. In the case of a sandal, for example, the outer shell would only have strapping. Other embodiments, such as a biking shoe, might have either netting, meshing, or no material where the bellows are shown, thus providing increased ventilation.
[0051] Moreover, the above embodiments described a flexible segment made of a bellows-shaped material, but other embodiments may use other materials, e.g., stretchable nylon, netting or meshing, or it may be omitted. Likewise all of the control features described had external features to activate the control, but other embodiment (e.g., cost-reducing embodiments or embodiments where hiding the control is desirable) may place the control mechanisms on the interior of the outer shell.
[0052] While the invention has been described in connection with certain preferred embodiments, it will be understood that it is not intended to limit the invention to those particular embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included in the appended claims. Some specific components, figures and types of materials are mentioned, but it is to be understood that such component values, dimensions and types of materials are, however, given as examples only and are not intended to limit the scope of this invention in any manner.
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An improved expandable shoe and inner assembly are disclosed. The expandable shoe includes an outer shell and an adjustable inner assembly is disposed within the outer shell. The inner assembly has a first board portion and a second board portion in overlapping engagement with each other and a control to adjust the position of the first board portion relative to the second board portion. The control includes a locking mechanism shaped to engage and hold one of the first and second board portions, a biasing mechanism to bias the locking mechanism into engagement with one of the first and second board portions; and an urging member having a proximal portion external of the shoe outer shell and positioned and movable transversely to a longitudinal direction of the shoe and in transverse alignment with the locking mechanism.
In one embodiment, a lighted visualization window provides a visualization window to the inner assembly. The inner assembly may include size markings through the visualization window so that a size of the adjusted shoe may be determined as shoe size is adjusted.
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The invention herein disclosed relates to thermoluminescence dosimetry and, more particularly, to a method and apparatus for measuring radiation doses using thermoluminescence dosimetry.
BACKGROUND
Thermoluminescence dosimetry (TLD) is a technique for measuring radiation doses, using a dosimeter. The dosimeter contains thermoluminescence (TL) elements made of a TL phosphor. When exposed to radiation, a TL element gets activated by the radiation energy. Thermoluminescence is a release of this absorbed radiation energy in the form of light which occurs when the TL element is heated. The amount of light energy discharged from the TL element corresponds to a dose of the radiation received by it. The amount of light energy discharged from the TL element is calculated by integrating the intensity of the thermoluminescence over a time it is observed.
The TLD has been developed to monitor environments in radiation fields. One particular application of the TLD is to monitor doses of radiation sustained by personnel who work in nuclear power plants. Each person working in a nuclear power plant is required to carry a dosimeter called a "TLD badge." The badge contains a TLD plate with one to four TL elements on it. Each person must wear the badge so that the badge will be exposed to the same dose of radiation as the person wearing the badge. Periodically, the badges are processed through a TLD reader to obtain an exposure record for each person being monitored. In the TLD reader, the TL elements on each TLD plate are heated by a heating device, such as an infrared lamp, and thermoluminescence from the elements is detected by a photomultiplier tube and processing circuitry. The detected thermoluminescence is then analyzed by an associated computer. Currently, processing of the TL badges is fully automated, and the TLD readers are capable of successively processing a large number of badges without human intervention. An example of such an automatic TLD reader is a Panasonic TLD Reader UD-710 or a Panasonic TLD reader UD-7900M.
The intensity of thermoluminescence from the TL elements is a function of heating temperature and time. To obtain accurate reading of radiation doses, the TL elements must be heated to a particular temperature for a particular period of time. The optimum heating temperature and time are selected through experiments. In the TLD reader mentioned above, the heating device is operated with programmed parameters so as to heat all the TL elements uniformly to the same optimum temperature for the same optimum time. However, the heat energy output from the heating device tends to change even though the heating device is operated with the same operation parameters. For instance, the heating temperature of the heating device gradually rises as the TLD reader processes the badges because of heat accumulated in the heating device. Also, the heating temperature of the heating device changes as the heating device ages. If the heating temperature exceeds or falls short of the optimum level, reading of radiation doses by the TLD reader will no longer be accurate.
Numerous attempts have been made to provide the TLD reader with a heat sensor for measuring in real-time the temperature of a TL element being heated. The TLD reader, if provided with such a heat sensor, could display to an operator the temperature of a TL element being heated or could alert the operator to deviation of the heating temperature from the optimum temperature level. But these attempts have all been unsuccessful. The problem is that a heat sensor cannot be positioned in place near the TLD element being heated. The heating device must be placed on one side of the TLD plate as closely to the target TL element as possible in order to excluding any outside thermal disturbances and heat all the TL elements uniformly. The photomultiplier must be placed on the other side of the TLD plate as closely to the target element as possible because thermoluminescence from the element is so weak. Simply, there is no physical space for any heat sensor near the TLD element being heated.
SUMMARY OF THE INVENTION
The present invention provides a TLD method and apparatus which can calculate the temperature of the TL element being heated. According to this invention, heat energy output from the heating device is detected by a heat energy sensor. The heat energy sensor may be positioned between the heating device and the TL element being heated. Based on the detected heat energy, the temperature of the element is calculated using a special equation. The calculated temperature is then used to determine if remedial action is necessary. For example, the calculated temperature is compared with a predetermined optimum heating temperature. If the calculated temperature deviates from the predetermined optimum heating temperature, responsive action is taken to prevent inaccurate radiation dose measurements.
According to another aspect of the invention, an increase rate of the calculated temperature is calculated and compared with a predetermined optimum heating rate. The heating device is controlled to increase its heat energy output if the calculated increase rate is lower than the predetermined optimum heating rate, and decrease its heat energy output if the calculated increase rate is higher than the predetermined optimum heating rate.
In a TLD apparatus in which the heat energy is output from the heat source in the form of heat pulses, the heat energy output is increased by raising the heights of the heat pulses, and decreased by lowering the heights of the heat pulses. The heat energy output may also be changed by widening or narrowing the widths of the heat pulses.
These and other objects of the invention are hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but one of the various ways in which the principles of the invention may be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the annexed drawings:
FIG. 1 is an illustration showing the mechanism employed in the TLD reader of this invention for automatically processing TLD badges;
FIG. 2 is a block diagram illustration showing the TLD reader in accordance with this invention;
FIG. 3(a) is a graph showing heat pulses (lamp on time) output from the heating device of the TLD reader in accordance with this invention;
FIG. 3(b) is a graph showing a typical temperature curve exhibited by the TL element being heated; and
FIG. 3(c) is a graph showing a typical glow curve exhibited by the TL element being heated.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, preferred embodiments of this invention are explained in detail. FIG. 1 shows the mechanism employed in the TLD reader of this invention for automatically processing TLD badges. FIG. 2 shows a block diagram of the same TLD reader.
As shown in FIG. 1, used badges 1 are placed side by side in an elongated magazine 2, which is then loaded into the TLD reader. In the TLD reader, the badges 1 are taken out from the magazine 2 one by one for reading of radiation doses. The badge 1 contains a TLD plate 3. An actuator arm 4 is used to remove the TLD plate 3 from the badge 1. The TLD plate 3 has four holes 5 arranged along its length. As shown in FIG. 2, each of the holes 5 contains a carbon loaded polyamide substrate 6. In the center of the substrate 6, the TL element 7 is positioned and covered with a fluororesin film 8. Those TL elements 7 are made of a TL phosphor, such as CaSO 4 or Li 2 B 4 O 7 . When the TL elements 7 are heated after having been exposed to radiation, thermoluminescence occurs at an intensity and for an interval of time correlatable to a dose of the radiation received by the elements.
As shown in FIG. 1, the badge 1 has four filters 9 of different thicknesses each located in a position corresponding to one of the holes 5. Thus, each TL element 7, which is not shown in FIG. 1 but located in the hole 5 between the substrate 6 and the fluororesing film 8, is covered by its own unique filter which provides different radiation absorption thicknesses to allow determination of type of radiation (Gamma, Beta, etc.) and radiation doses received by the person who wore the badge. The badge 1 is also provided with a machine readable code 10 to enable automatic identification of the person who wore the badge. The code 10 is scanned by an optical reading device 11. The TLD reader has an infrared lamp 12, and a photomultiplier tube 14 with a light guide 13 placed opposite to the lamp 12.
After a badge 1 is taken out from the magazine 2, the TLD plate 3 is removed from the badge 1 by the actuator arm 4. The TLD plate 3 removed from the badge 1 is positioned between the lamp 12 and the light guide 13. The lamp 12 then heats a target TL element 7 of the TLD plate 3. The light guide 13 collects thermoluminescence from the element 7. The photomultiplier 14 detects the thermoluminescence and converts it into electrical signals. After one element has been processed, the TLD plate is moved along its length, and the lamp 12 heats an adjacent element 7. The lamp 12 heats one element at a time and thus repeats its heat treatment up to four times for one badge. In the meantime, the optical reading device 11 scans the code 10 provided for the badge 1 to identify the person who wore the badge.
Turning to FIG. 2, the TLD reader according to the present invention has a control unit 15. The control unit 15 transmits pulse signals to the lamp 12 through a power supply 16 to turn on and off the lamp 12. The lamp 12 is fronted with a silicon filter 17 which allows only infrared light to pass through. The lamp 12 is also provided with a cone-shaped reflector 18 for focusing infrared light passing through the filter 17 onto a target element 7 positioned in front of the reflector 18. The distance between the light guide 13 and the reflector 18 is made as small as almost equal to the thickness of the TLD plate 3 for the purpose of effectively focusing infrared light onto the element 7 and collecting as much thermoluminescence from the element 7 as possible. The reflector 18 of the lamp 12 is provided in its periphery with a heat flux sensor 19 sticking into the interior of the reflector 18. The heat flux sensor 19 detects heat energy inside the reflector 18 and transmits signals through an amplifier 20 to the control unit 15. A heat flux sensor having these capabilities is a Thermogage HFM6 manufactured and sold by Vatell Corporation, Blackburg, Va.
As mentioned earlier, a radiation dose is calculated by integrating the intensity of thermoluminescence over a time it is observed. The photomultiplier 14 converts thermoluminescence into electrical signals and transmits those signals through an amplifier 21 to a hybrid integrator 22. The hybrid integrator 22 contains photon and frequency counters. Based on the signals from the photomultiplier 14, the hybrid integrator 22 counts photons emitted from the TL element 7 for millisecond intervals and transmits a photon count to the control unit 15 at every millisecond. A photon count at particular point in time represents the intensity of thermoluminescence at the same point. The control unit 15 performs various tasks based upon the photon counts transmitted by the hybrid integrator 22. One of the important tasks for the purpose of this invention is to determine a radiation dose. The control unit 15 calculates a radiation dose by integrating the photon counts transmitted by the hybrid integrator 22.
FIGS. 3(a)-(c) are graphs showing one cycle of heat treatment by the TLD reader. Those graphs have the same time scale and are hence related. The TLD reader performs the same heat treatment cyclically on each element 7. One cycle of heat treatment includes three heating stages identified as preheating, read-out and annealing. The heating of each element 7 begins with the preheating stage, then moves on to the read-out stage and ends with the annealing stage. The preheating is conducted to remove energy induced in the TL element through exposure to noise energies, such as ultraviolet rays. The annealing is for erasing any residual energy in the element 7 to place it in condition for reuse. Thermoluminescence observed during the preheating and annealing stages is considered interfering and disregarded from calculation of a radiation dose. Thus, integration is performed only on the thermoluminescence observed during the read-out stage.
The graph of FIG. 3(a) plots two items with respect to time. The top line represents the intensity of the lamp 12. The bottom line represents whether photon counting is occurring or not. As shown in FIG. 3(a), the control unit 15 sends three pulses to the lamp 12 through the power supply 14. The lamp 12 is turned on and off three times in concurrence with the pulses during one cycle of heat treatment. Each pulse is associated with one of the three stages and serves to trigger the associated stage. The widths of the three pulses and the intervals between two adjacent pulses are defined by nine parameters T 0 , T 1 , T 2 , T 3 , T 4 , T 5 , T 6 ,T 7 and T 8 . T 0 defines a time between the beginning of the first pulse and the beginning of photon counting by the control unit 15; T 1 defines a time between the beginning of the photon counting and the end of the first pulse; T 2 defines a time interval between the first and second pulses; T 3 defines a time between the beginning of the second pulse and the beginning of the integration by hybrid integrator 22; T 4 defines a time between the beginning of the integration and the end of the second pulse; T 5 defines a time between the end of the second pulse and the end of the integration; T 6 defines a time between the end of the integration and the beginning of the third pulse; T 7 defines the width of the third pulse; and T 8 defines a time between the end of the third pulse and the end of the photon counting by the hybrid integrator 22. Thus, the hybrid integrator 22 performs the photon counting for a time period defined by T 1 +T 2 +T 3 +T 4 +T 5 +T 6 +T 7 +T 8 . The control unit 15 performs the integration for period defined by T 4 +T 5 .
These parameters have been selected through experiments so that the element 7 will be heated to the optimum temperature for the optimum time during each of the three stages. The selected parameters are programmed in the control unit 15. The table below shows typical programmed parameters used in this invention.
______________________________________T.sub.0(ms)T.sub.1(ms) T.sub.2(ms) T.sub.3(ms) T.sub.4(ms) T.sub.5(ms) T.sub.6(ms) T.sub.7(ms) T.sub.8(ms)______________________________________1 65 500 50 45 400 150 35 1700______________________________________
The three heat pulses defined by these nine parameters raise the temperature of the element 7 in such a manner as shown in FIG. 3(b). The temperature curve as shown in FIG. 3(b) is obtained through an experiment in which the photomultiplier 14 is replaced with a heat sensor. Generally, the temperature of the element 7 steps up at the beginning of each stage and levels off during the stages. By carefully selecting the above parameters, the temperature of the element 7 can be maintained at the optimum level during each stage. The optimum temperature for each stage varies depending on the kind of a TL element used. For the TL element used in this invention, such as CaSO 4 or Li 2 B 4 O 7 , the optimum temperature for the preheating stage is within the range of about 100° C. to about 150° C. The optimum temperature for the read-out stage is within the range of about 250° C. to about 300° C. The optimum temperature for the annealing stage is within the range of about 300° C. to about 350° C. These optimum temperature ranges are stored in the control unit 15 and, as explained later, are used to detect deviation of the heating temperature from the optimum level.
FIG. 3(c) shows a photon count curve. This photon count curve is obtained by plotting photon counts from the hybrid integrator 22 as a function of time. This curve is called "glow curve" and shows the intensity of thermoluminescence as a function of time. The glow curve has three peaks I, II and III. The first peak I appears during the preheating stage. This peak is caused by noise energies and should be disregarded. The middle peak II appears during the read-out stage and reflects doses of radiation received by the element 7. The third peak III appears during the annealing stage. The peak III is caused by residual energy and should also be disregarded. As explained above, the control unit 15 performs integration for a time period defined by T 4 +T 5 . The time period T 4 +T 5 is defined such that it covers thermoluminescence caused by radiation to be measured and exclude interfering thermoluminescence caused by noise and residual energies. As a result of the integration, the area of the shaded potion of the glow curve in FIG. 3(c) is calculated, which represents radiation doses received by the element 7.
While heating a TL element 7, the control unit 15 receives signals from the heat flux sensor 19. Based on the signals from the heat flux sensor 19, the control unit 15 calculates the temperature of the TL element being heated. The inventors of this invention have found and confirmed through experiments that the following equation approximates very well the actual temperature of the TL element 7 being heated:
T.sub.i+1 =T.sub.i +A(hf.sub.i -B(x.sup.Ti/τ -1))+C, (1)
where T i is a calculated temperature at a particular time i; hf i is reading of heat energy by the heat flux sensor at a particular time i; (x Ti/ τ -1) is a heat loss term wherein x and τ are heat loss constants; and A, B and C are scaling factors. The scaling factors A, B and C and the heat loss constants x and τ are selected through computer simulation so that the above equation will achieve the best approximation.
The temperatures calculated by using the above equation (1) are used to determine if remedial action is necessary. In the TLD reader of this invention, the control unit 15 determines, based on the optimum temperature ranges stored in it, whether the temperature it just calculated falls within the optimum temperature range for that time point. If it is determined that the calculated temperature falls out of the optimum temperature range, responsive action is taken to prevent inaccurate radiation dose measurements. In the TLD reader of this invention, if it is determined that the calculated temperature falls out of the optimum temperature range, the control unit 15 will activate an alarm device and stop processing the badges.
In the second preferred embodiment of this invention, the control unit 15 further comprises a heat controller to control heat energy output from the lamp 12. The second embodiment of this invention includes all of the mechanical and electrical elements of the first embodiment. Therefore, the explanations given with respect to the first embodiment are all applicable to the second embodiment. The second embodiment further includes a heating rate data stored in the control unit 15. The heating rate data represents the average slope of the temperature curve in FIG. 3(b) observed during time period T 0 +T 1 .
While heating the element 7, the control unit 15 calculates an average increase rate of the temperatures it calculated during time period T 0 +T 1 . The control unit 6 then compares the calculated increase rate with the stored heating rate. If the increase rate is lower than the stored heating rate, the lamp 12 is outputting less heat energy than it is supposed to be. If the increase rate is higher than the stored heating rate, the lamp 12 is outputting more heat energy than it is supposed to be. Therefore, if it is determined that the increase rate is lower than the stored heating rate, the control unit 15 instructs the power supply 14 during the next heat treatment cycle to raise the heights of the three pulse sent to the lamp 12. The heat energy output from the lamp 12 increases, accordingly. Conversely, if it is determined that the increase rate is higher than the stored heating rate, the control unit 15 instructs the power supply 14 during the next heat treatment cycle to lower the heights of the pulses sent to the lamp 12. The heat energy output from the lamp 12 decreases, accordingly.
In the third preferred embodiment of this invention, the control unit 15 also comprises a heat controller to control heat energy output from the lamp 12. The third embodiment of this invention includes all of the mechanical and electrical elements of the second embodiments except that the nine parameters T 0 , T 1 , T 2 , T 3 , T 4 , T 5 , T 6 , T 7 and T 8 are variable and that the parameters given in the table are used as initial parameters.
Just as in the second embodiment, the control unit 15 of the third embodiment calculates an average increase rate of the temperatures it calculated during time period T 0 +T 1 . The control unit 15 then compares the calculated increase rate with the stored heating rate. If it is determined that the increase rate is lower than the stored heating rate, the control unit 15 instructs the power supply 14 during the next heat treatment cycle to widen the widths of the three pulse. The heat energy output from the lamp 12 increases, accordingly. Conversely, if it is determined that the increase rate is higher than the slope, the control unit 15 instructs the power supply 14 during the next heat treatment cycle to narrower the widths of the pulses. The heat energy output from the lamp 12 decreases, accordingly. There are three ways to change the widths of the pulses. In the first way, the beginning timing of each pulse is changed while the intervals between the end timing of adjacent pulses are made constant. In the second way, the end timing of each pulse is changed while the intervals between the beginning timing of adjacent pulses are made constant. In the third way, both beginning and end timing of each pulse is changed while the intervals between the centers of adjacent pulses are made constant.
Although the invention had been should and described with respect to preferred embodiments, it will be apparent that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and is limited only by the scope of the following claims.
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A method and apparatus for measuring radiation doses based upon thermoluminescence which occurs when a thermoluminescence element is heated by a heat source after having been exposed to radiation. A heat energy sensor is provided for the heat source for detecting the heat energy output from the heat source toward the element. Based on the detected heat energy, the temperature of the element is calculated. The calculated temperature is used to determined if remedial action is necessary. For instance, the calculated temperature may be compared with a predetermined optimum heating temperature. If the calculated temperature deviates from the predetermined optimum heating temperature, responsive action is taken. An increase rate of the calculated temperature may also be calculated. The calculated increase rate would be compared with a predetermined heating rate. The heating device would increase its heat energy output from it if the calculated increase rate is lower than the predetermined heating rate and decreasing the heat energy if the calculated increase rate is higher than the predetermined heating rate.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to computer programming, and deals more particularly with techniques for developing a graphical editor using an incremental development approach.
[0003] 2. Description of the Related Art
[0004] Conducting business electronically using distributed networking environments such as the Internet—commonly referred to as “e-business”—is increasingly popular with business enterprises throughout the world. Providing e-business software—that is, software with which an enterprise provides its “electronic presence” in the e-business marketplace and conducts business electronically—can be a complex, time-consuming, and costly undertaking. Vendors such as the International Business Machines Corporation (“IBM”®) provide their customers with platforms and tools to assist in this process. Such platforms and tools must fulfill user's needs while being developed in a brisk-paced approach in order to remain competitive. (“IBM” is a registered trademark of the International Business Machines Corporation in the United States, other countries, or both.)
[0005] Today, tools for developing e-business software (as well other types of software) are commonly composed from many functional components. One of the main components of many tools is a graphical editor. Graphical editors present views of underlying domain models using graphical representations that include elements such as circles, boxes, lines, images, and icons. Graphical editors can be used for modeling things such as business processes, application models, or even user interface (“UI”) screens. Since graphical editors mainly interact with users, a key success factor of graphical editor design is to have an appropriate usability that simplifies the user interactions and meets the user needs.
[0006] Creating a graphical editor is not an easy task, and requires considerable interaction with usability analysts. Usability analysts are people who are concerned with defining the requirements for effectiveness, efficiency, and satisfaction with which the end users can achieve tasks when using an application. When defining these requirements, usability analysts often consult people such as media designers, domain modelers, and high-privilege user groups.
[0007] There are many different approaches in designing a graphical editor. One approach focuses on how to describe the requirements. When designing according to this approach, a story board is often used to describe snapshots of visual views and the relationship of the visual elements. However, this approach can only describe a high-level relationship between visual views, and seems insufficient when trying to describe the details of each visual element.
[0008] Another, more expensive, approach is to develop a prototype. A prototype will provide a product-like, high-level perspective of the editor's usability behavior, and can be used to depict some of the high-level requirements of the graphical editor. The prototype is normally developed in a fast-paced manner in order to reduce the development cycle, cut costs, and/or avoid addressing some of the technical details that cannot be resolved at that moment. A major drawback of prototypes, however, is that they only try to present the general idea of the editor, and the developed prototype code typically cannot be reused in development of the editor itself. In addition, the usability requirements captured in the prototype stage may not accurately reflect the needs of the developed product.
[0009] In another approach, which speeds up the development cycle, a framework is provided. The framework approach can be used in development of prototypes or in actual product development cycles, and can reduce a fair amount of coding time. However, this approach still requires considerable effort to create an actual implementation. Since this approach is somewhat inflexible, it requires cautious planning and proactive process control since normally, requirements can only be accommodated in the early stage of the development cycle. Unfortunately, this does not match the nature of usability analysis, which tends to be an iterative process.
[0010] Today, developing a graphical editor of a tool normally follows the framework approach and uses the so-called “model-view-controller”, or “MVC”, pattern. The MVC pattern consists of three kinds of objects. The Visual (“V”) object is the view representation in the graphical editor. The Model (“M”) object is the domain model that the visual object represents. Finally, the Controller (“C”) object defines how the user interface reacts to the user input. The MVC pattern has been applied to many different graphical editor frameworks.
[0011] As an example, the Eclipse Graphical Editing Framework (“GEF”) is sometimes used as a graphical editor development framework. (Eclipse provides an open-source framework that is commonly used for development of e-business applications.) GEF provides a set of application programming interfaces (“APIs”) for software developers to use and extend when developing their code. As discussed above, using this framework approach provides some benefits to reduce the development cycle; however the cycle is still not short enough. It also does not provide the flexibility to modify the editor when needed.
[0012] The above approaches are not fully effective for developing graphical editors because usability analysts do not have the capability to touch and feel the product in sufficient, representative detail in the early milestone or phase of a software development cycle. Using the current approaches, the most effective way to provide a graphical editor is to develop a full product and then allow the usability analysts to study the problems and fix those problems in the next development cycle. However, this after-the-fact approach may cause the failure of the product in the marketplace.
SUMMARY OF THE INVENTION
[0013] The present invention enables an incremental development approach, whereby a prototype-like graphical editor can be developed in the early stage of a product development cycle. By overlapping the prototyping cycle with the development cycle, the invention provides a solution that allows developers to quickly create a graphical editor. At this early stage, the graphical editor can be considered a product deliverable which supports a primary view of the (eventual) editor. Thus, the graphical editor can be released to the usability analysts for their review and comments while the tool for which the editor is being provided is still in the development cycle.
[0014] At later stages in the product development cycle, the invention enables incrementally adding new functions and behaviors to the graphical editor when new requirements are identified. The cost and duration of the development cycle can be reduced through use of the present invention, which may also greatly reduce mistakes when communicating users' requirements to the development team. As an added benefit, related users can participate in the design of tools in the early stage of development.
[0015] In terms of the invention, the visual model is the context model that the user interacts with, while the domain model captures the domain information. An instance of visual model elements displayed in the graphical editor represents a domain model element or object, or a group of domain model elements of the same type. Taking a graphical editor for an organization as an example, a person-shaped icon might be used to represent an employee in a view provided through the editor, or perhaps several of the person-shaped icons might be presented to represent several of the employees. The actual association between visual model element(s) and the corresponding domain model element(s) can be realized in a later stage in the development cycle, thereby enabling work on the organization-oriented graphical editor to begin in parallel with work on the domain model definition.
[0016] Preferred embodiments store the visual model in a structural file that is separated from a structural file containing the persistent data of the domain model elements. Preferably, XML is used for specifying these structural files, although other markup languages may be used without deviating from the scope of the invention. (Examples of structural files are discussed below with reference to FIGS. 5 and 7 , which depict a sample domain model structural file and a sample visual model structural file, respectively.) The abstraction of the visual models facilitates the rapid development of the graphical editor, for the visual behaviors are a major concern of the usability analysts and the tooling developers, especially when the domain models are still going through refinement iterations.
[0017] The separation of the visual relationships from the domain object relationships helps the tooling developers focus on the tooling requirements. For example, a department has an aggregating relationship with its employees. In an organization modeling tool, a department may be presented visually as an owned element of a manager, who is one of the department employees. The visual relationship between the manager and the department illustrated in the editor does not necessarily match the relationship defined in the domain models, but satisfies the tooling requirements.
[0018] Overall, the invention can create visual models for modeling a domain, without first requiring the domain model to be defined. Externally-stored descriptors are used to specify information on which a graphical editor engine operates to create a graphical editor. The invention allows developers to redefine the look and feel of the graphical editor by modifying these descriptors, thus re-configuring the elements of visual models without changing the code of the graphical editor engine. This minimizes the development cycle and provides a rapid, incremental, intuitive approach for graphical editor development.
[0019] In one aspect, the present invention provides a method of enabling incremental development of a graphical editor, comprising steps of: providing an editor engine component that creates the graphical editor; adapting the editor engine component to process a visual model structural file, wherein the visual model structural file describes a visual model supported by the editor engine, adheres to a specified visual meta-model, identifies a visual model descriptor file, and supports graphical editing of one or more domains; and adapting the editor engine component to process the identified visual model descriptor file, wherein the identified visual model descriptor file specifies constraints on the visual model and adheres to a specified visual descriptor meta-model, and wherein the processing of the visual model descriptor file thereby configures behavior of the visual model in the graphical editor.
[0020] In another aspect, the present invention provides a system for enabling incremental development of a graphical editor, comprising: an editor engine component that creates the graphical editor; processing means in the editor engine component for processing a visual model structural file, wherein the visual model structural file describes a visual model supported by the editor engine, adheres to a specified visual meta-model, identifies a visual model descriptor file, and supports graphical editing of one or more domains; and processing means in the editor engine component for processing the identified visual model descriptor file, wherein the identified visual model descriptor file specifies constraints on the visual model and adheres to a specified visual descriptor meta-model, and wherein the processing of the visual model descriptor file thereby configures behavior of the visual model in the graphical editor.
[0021] In yet another aspect, the present invention provides a computer program product for enabling incremental development of a graphical editor, wherein the computer program product is embodied on one or more computer-readable media and comprises computer-readable instructions for: executing an editor engine component that creates the graphical editor; processing, by the editor engine component, a visual model structural file, wherein the visual model structural file describes a visual model supported by the editor engine, adheres to a specified visual meta-model, identifies a visual model descriptor file, and supports graphical editing of one or more domains; and processing, by the editor engine component, the identified visual model descriptor file, wherein the identified visual model descriptor file specifies constraints on the visual model and adheres to a specified visual descriptor meta-model, and wherein the processing of the visual model descriptor file thereby configures behavior of the visual model in the graphical editor.
[0022] The present invention will now be described with reference to the following drawings, in which like reference numbers denote the same element throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 shows a high-level representation of components involved in preferred embodiments of the invention;
[0024] FIG. 2 provides a flowchart illustrating how the present invention may be used for creating graphical editors;
[0025] FIG. 3 presents a visual representation of a sample domain model (representing houses) that is used in describing preferred embodiments;
[0026] FIG. 4 provides a sample meta-model (using Unified Modeling Language, or “UML”, notation) for domain objects in the domain illustrated by FIG. 3 , and
[0027] FIG. 5 provides a sample domain object specification according to this meta-model, where this specification is encoded in the Extensible Markup Language (“XML”);
[0028] FIG. 6 describes, using UML notation, components of the Common Visual Meta-model used in preferred embodiments;
[0029] FIG. 7 provides an example of a Common Visual Model for the domain model specified in FIG. 5 and illustrated in FIG. 3 ;
[0030] FIG. 8 provides an example of a Visual Model Descriptor for the domain model specified in FIG. 5 and illustrated in FIG. 3 ;
[0031] FIG. 9 depicts, in UML notation, the Visual Model Descriptor Meta-model exemplified by FIG. 8 ;
[0032] FIG. 10 shows a sequence diagram of creating visual model elements, according to preferred embodiments; and
[0033] FIG. 11 (comprising FIGS. 11A and 11B ) depicts a flowchart that shows a sample scenario of using a preferred embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0034] The present invention provides incremental graphical editor development capability, using combined modularity patterns by introducing a visual composition model and a set of visual modules. FIG. 1 shows a high-level representation of components involved in preferred embodiments of the invention. As illustrated therein, the visual composition model comprises what is referred to herein as a “Common Graphical Editor System” 100 . This system interfaces with supporting models 155 , while the set of visual modules is preferably realized using pre-built plug-and-play parts 170 .
[0035] In preferred embodiments, the invention categorizes visual composition models into two basic kinds, a node semantic model and a link semantic model, and creates a common interface (referred to herein as a “Common Visual Model”, illustrated at 145 in FIG. 1 ) which defines the common behavior of all the visual composition models. “Semantic models”, as that term is used herein, describe the meanings of a particular model, but not the visual representation of the model. Objects that must coexist with exactly two other objects are abstracted as link semantic model elements. Other objects are captured as node semantic model elements. For example, a person can be imagined as having the node semantic because the person can stand alone during modeling, whereas the parental relationship between two persons can be imagined as having the link semantic. However, the visual representations of persons and of relationships between persons can be very different. Persons (or “person nodes”) might each be visually represented as independent boxes on the UI, for example, while the parental relationship might be visually represented by a line with an arrowhead pointing from the parent toward the child, or perhaps as nested boxes where, for example, a box for the child sits inside a box for the parent on the UI.
[0036] The visual depiction of a link may have a number of different forms, depending on factors such as the underlying model and the decisions of the usability analysts. As examples, a link may be shown by a line or arc, or as in the parental example discussed above, by the graphical position or composition between node depictions.
[0037] To fully capture the visual composition behaviors, the invention also categorizes the relationships among nodes. In preferred embodiments, three types of categorization are used: composition ownership, content ownership, and reference. For example, when modeling a house in a graphical editor, the house may have composition elements such as windows, doors, walls, roofs, etc.; may have content elements such as the people living in the house, furniture, paintings on the walls, etc.; and may have reference relationships with neighboring houses. Nodes that can have composition elements are furthered categorized as composition nodes.
[0038] Nodes and links can have many different graphical representations and composition behaviors. They can also represent different domain model elements. Referring again to the graphical editor for an organization, a node can represent an employee of the company. The graphical representation of an employee can be a figure of a circle or box, or a human being image or icon. A link between two employees can represent the management relationship. The graphical representation of the link can be a solid link with an arrow pointing to the employee who is being managed or pointing to the manager to whom an employee reports. Using the same example, a container node could be used to represent a department. The composition elements of the container, which are the employee nodes connected to the department node, represent the employees who work for the department. In terms of graphical editing, when a department is moved (relocated), the employees and the management relationships are also moved at the same time. This indicates that the visual composition behavior of the common visual model reflects the actual composition behavior of an organization.
[0039] In preferred embodiments, the invention uses optional references to detach visual models from domain models. (See, for example, 146 in FIG. 1 , where this is illustrated.) This approach offers several benefits which are not available with the conventional approach to loose coupling of presentation data and domain data, including:
[0040] (1) a visual model can be created in the early stage of a product development cycle, without awaiting knowledge of the domain model for that product. In fact, a visual model can be created without a domain model. The association of the domain model with the visual model can then be deferred, and performed at a later stage (for example, after the domain model design is finalized). This enables the parallel development of the graphical editor and the domain model(s); and
[0041] (2) the reuse of a visual model for different types of domain models, the independence of the visual tooling, and the conceptual assistance to domain model design (e.g., whereby usability analysis results obtained with a visual model can be fed back as refinements for the domain model design).
[0042] Preferred embodiments of the invention isolate the visualization data from domain data so that a small set of visual models can represent a virtually unlimited number of different kinds of domain objects. The visual model can be externalized (or persisted) in a separate structural file. This allows a particular domain model to have different visual models for targeting different usages, if desired. That is, in addition to using one visual model for multiple domain models, a particular domain model may be associated with more than one visual model.
[0043] In preferred embodiments, the invention uses the descriptor mechanism (i.e., a set of externalized specifications that are read and processed) that allows developers to define and configure the properties of the visual elements in the graphical editor. For example, one can define the basic shapes of a visual element, the composition behaviors, and the relationships with other visual elements. One or more of these properties can be changed, if necessary, by modifying the appropriate descriptor information. Developers are also able to define the types of the domain model elements that will be associated with the visual elements. With reference to the person and parent example discussed earlier, a developer might therefore create a descriptor specifying that person nodes are to be represented using graphical boxes; that persons can be related by a parental relationship; and that person nodes can be therefore be graphically composed in certain ways to indicate this relationship (such as by nesting the related box shapes). See also FIG. 8 , discussed below, where a sample descriptor for a visual model is provided.
[0044] In order to enable a fast-paced development cycle as well as enable incrementally adding new behaviors for the modeled elements, preferred embodiments of the invention support use of plug-and-play parts (as noted earlier with reference to 170 in FIG. 1 ). Parts are preferably deployed as modules that can be used when creating editors. For example, a box shape may be provided as a pre-built part, where this box shape can be used as a graphical representation of a person node. Or as one alternative, a person node might be represented using a pre-built part that depicts an iconic representation of a person's head. Preferred embodiments also provide a framework for developers to create (or extend) parts when none of the pre-built parts are appropriate, and whereby one or more classes are provided for working with the pre-built parts. As a result, developers are able to create a prototype-like graphical editor immediately, leveraging these pre-built parts, without the need to build parts from scratch. The developers can then spend time to provide more details for each individual part as needed.
[0045] Together, the deferred association of a visual model instance with a domain object and the configuration of visual model behaviors through externalized descriptor data, as discussed above, provide the capability of developing graphical editing tools incrementally and intuitively without awaiting full prototyping cycles.
[0046] By using the invention, developers are able to create a graphical editor quickly. The editor can then be passed to the usability analysts to study whether the existing product requirements are addressed properly, and/or whether there are additional requirements that have not been identified. The recommendations from the usability analysts can then be fed back to the development team to incorporate into the next iteration. This development process is illustrated in FIG. 2 , as will now be discussed.
[0047] Initially, a document of the visual model, including behaviors of the visual model elements, is produced (Block 200 ). Developers then create a graphical editor descriptor based on this document (Block 210 ). (Refer also to the description of FIG. 8 , below, where a sample descriptor for a visual model is presented.) In preferred embodiments, this descriptor is registered with the editor engine (Block 220 ). See also FIG. 1 , where descriptor 105 is registered 106 to registry 110 .
[0048] At Block 230 , the editor engine then creates a graphical editor which may be used, for example, for testing or other analysis. Block 240 represents a decision as to whether the usability analysts have justified the behavior as presented. If so, then the process shown in FIG. 2 ends (Block 250 ). Otherwise, the document of the visual model is updated (Block 260 ), which may include revisions suggested by the usability analysts, and control returns to Block 200 where this revised document is used as input for another iteration.
[0049] As was noted earlier with reference to FIG. 1 , the mechanism of the invention is conceptually divided into two pieces: a set of pre-built parts and a common graphical editor system. Each of these will now be described in more detail.
[0050] The set of pre-built parts was briefly discussed above with reference to 170 of FIG. 1 . In preferred embodiments, these pre-built parts include a set of common edit parts 171 , a set of common FIGS. 172 , and a set of sample or reference icons 173 . Providing these pre-built parts enables creating a prototype-like graphical editor very quickly, whereby graphical representations can be created from the provided parts without spending too much time on developing parts from the ground up.
[0051] The common edit parts 171 are preferably used to describe behaviors of visual elements. An edit part for a line, as one example, is preferably provided that allows a user to drag the end of the line and thus extend the line. Similarly, an edit part for a box is preferably provided that enables the user to resize the box by dragging a line (i.e., side) of the box. Common edit parts may also be provided for operating on representations of nodes, links, containers, content, labels, and so forth. The common figures 172 preferably provide graphical representations such as boxes (i.e., rectangles and/or squares), circles, ovals, lines, arrows, etc., which can be used to visually represent a semantic model. The reference icons 173 may also be used to visually represent a semantic model, as well as to further categorize the type of figure depicted. (As discussed briefly above, a “person” icon might be provided so that users can depict people using a representation that is more natural than a figure such as a box or circle.)
[0052] The components of the Common Graphical Editor System (shown generally at 100 in FIG. 1 ) of preferred embodiments comprise a Descriptor Registry 110 , Visual Model Descriptor 125 , Common Graphical Editor Factory 130 , Common Graphical Editor 135 , and Common Visual Model 145 . A sample domain model (representing houses) that will be used in describing preferred embodiments will now be introduced, after which the components shown in FIG. 1 will be described in more detail.
[0053] FIG. 3 presents a visual representation 300 of a domain model representing houses. (This domain model is used herein, by way of illustration only, in further describing preferred embodiments.) As shown therein, a house object from the domain model is visually represented as a box 310 . This sample house includes two windows 320 , 321 and one door 330 . This sample house is furnished with a sofa 340 , a table 350 , and four chairs 360 . This house 310 is also depicted as referencing 371 a neighbor's house 370 .
[0054] FIG. 4 provides a sample meta-model 400 for this domain object representation 300 , and FIG. 5 provides an XML document 500 that specifies a sample domain object specification according to this meta-model 400 . As shown by these examples, a <house> element 510 identifies this particular domain object as “bobHouse” 511 (i.e., “Bob's house”, in this example); a <doors> element 520 indicates that Bob's house has a door identified as “southEntryDoor” 521 ; a <windows> element 530 specifies that Bob's house has two windows 531 , 532 ; and a <furniture> element 540 lists furniture associated with Bob's house. In particular, the <furniture> element 540 further comprises child elements that identify the particular sofa, table, and chairs in this house. Attributes in domain model specification 500 specify details of these various features of Bob's house (such as the material from which Bob's sofa and table are made; see 541 , 542 ). The <neighbor> element 550 identifies a neighbor's house (in this example, having an attribute value of “janeHouse”). According to domain model 400 of FIG. 4 , element 550 indicates that Bob's house is linked to this identified house. XML document 500 thus contains a second <house> element 560 that specifies further information about this linked house 550 .
[0055] FIGS. 7 and 8 , discussed below, also refer to the house domain model.
[0056] As noted earlier with reference to FIG. 1 , preferred embodiments of the invention use a Common Visual Model 145 which defines the model elements from which graphical editors are composed. FIG. 6 depicts the Common Visual Meta-model. (Refer also to FIG. 7 , which is described below, where a sample document according to this meta-model is provided.) As shown in FIG. 6 using a UML diagram, a Common Graphical Editor Model component (see 620 ) represents the model of all graphical editors. The “Inclusion” element 630 represents the common visual model 640 included in the editor. Inside the Inclusion element, there may be “CommonNode” elements 650 , “CommonLink” elements 660 , “Composition” elements 670 , and “CommonLabel” elements 680 . A “domainObject” element 610 , representing a particular object from the domain model, can be graphically presented with different figures or images. (A person can be represented using a box or a person-like icon, for example, as discussed earlier.) Conversely, each visual model element can represent different domain model elements. (A box might represent a person, a house, or many other types of domain model elements, for example.)
[0057] FIG. 7 provides a sample document 700 that specifies a visual model according to the meta-model in FIG. 6 . A <composition> element 710 includes an “id” attribute 712 and a “descriptor” attribute 713 , specifying an identifier for a descriptor and the location (by reference to the namespace element 711 ) of an external file where this descriptor (such as descriptor 800 of FIG. 8 , in this example) is stored. As noted in the comments 720 , there is no tight coupling between this visual model 700 and the separately-stored descriptor identified at 713 . (For example, a different descriptor can be associated with visual model 700 by replacing the value of attribute 713 .)
[0058] A “domainObject” element 714 includes an “href” attribute 715 . As noted in comments 722 , the value of attribute 715 identifies the location of an external file where a domain object specification (such as specification 500 of FIG. 5 , in this example) is stored. Comments 722 further note that there is no tight coupling between this visual model 700 and the separately-stored domain object identified at 715 . (For example, a different domain object can be associated with visual model 700 by replacing the value of attribute 715 .)
[0059] The <compositionElements> element 730 includes <commonNode> elements 732 , 736 , and 740 . Each of these node elements specifies details for nodes that may be visually represented using a graphical editor created according to document 700 . Element 732 , for example, specifies information for a door, referring to an externally-stored descriptor (see 733 ) for this door and identifying (see 734 ) where the domain object specification for this particular door (within the house identified at 715 , in this example) is stored. Similarly, elements 736 and 740 specify information pertaining to two windows.
[0060] As noted in comments 744 , the <includedElements> element within element 750 is a type of visual relationship, as are the <compositionElements> element 730 and the <commonLink> element 770 . Comments 744 also note that additional (or different) types of visual relationships might be specified in a particular visual model.
[0061] The <content> element 750 further contains child elements pertaining to nodes (i.e., <commonNode> elements). In this example, the information for each node comprises a reference to a descriptor for that node (see, for example, 752 ) and a reference to a domain object for that node (see, for example 753 ), where the domain objects are elements of the furniture in the particular house identified at 715 . Note that the specification of doors, windows, and furniture in FIG. 7 corresponds to the visual representation of the sample house shown in FIG. 3 .
[0062] The <composition> element 760 is similar to element 710 , and in this example, specifies similar information for the linked or referenced house (e.g., where to find a descriptor, 761 , and where to find a domain object, 762 , for this referenced house). The <commonLink> element 770 then specifies attributes of a visual reference that serves to graphically link the two houses “house 1 ” and “house 2 ” according to the “neighborLink 1 ” relationship.
[0063] In order to cope with an incremental development process, another component of preferred embodiments is the Visual Model Descriptors (represented at 105 in FIG. 1 ). XML documents are preferably used for documenting these Visual Model Descriptors. A visual model descriptor holds specific properties of visual model element 181 such as the domain model element type 182 , the type of FIG. 184 to use for that domain model element, the icon 185 , its edit part 186 (i.e., its behaviors), and its constraints 183 . (All model elements may have constraints that are applicable to them.) Referring now to FIG. 8 , an example of a Visual Model Descriptor 800 for the house scenario is provided, as will now be discussed.
[0064] Element 810 specifies a <compositionDescriptor> for the house domain model. Attribute 811 identifies the domain model element type as being “houseDescriptor” (intuitively indicating that this is a visual descriptor for a “house” domain object). Attribute 812 specifies that the edit part with which the graphical representation of this domain object can be edited is named “houseEditPart” (i.e., the class name for this edit part is “com.ibm.sample.houseEditPart”), and attribute 813 specifies that the graphical figure to be used for visually depicting this domain object is named “rectangleFigure” (i.e., the class name for this figure is “com.ibm.btools.rectangleFigure”).
[0065] A child element of the <compositionDescriptor> 810 is <compositionContraints> element 815 , which specifies the composition type relationships available for the visual model of this object. In this example, element 815 specifies that the house object can have composition type relationships with visual models which are graphically represented as door images and window images. The individual <compositionConstraint> elements within element 815 further specify a maximum number of each of these elements using a “cardinality” attribute. According to this example, doors and windows can thus be associated with a house, and the number of doors is limited (by the cardinality attribute) to 2, while the number of windows is limited to 10.
[0066] Another child element of the <compositionDescriptor> 810 is <inclusionConstraints> element 817 . In this example, element 817 specifies that the house object can have inclusion type relationships with visual elements which are graphically represented as bed images, chair images, desk images, sofa images, and table images.
[0067] The final child element of the <compositionDescriptor> element 810 , in this example, is the <inputConstraints> element 819 . According to this example, the maximum number of houses that can be referenced, using link relationships, from a particular house is 4.
[0068] Next, <commonNodeDescriptor> elements 820 , 830 , 840 , 850 , 860 , 870 , 880 specify each of the node descriptors that were previously referenced (using the “part Id” attribute) at 815 and 817 , and further specify the edit part to be used with each of these nodes and the figure that will represent each node when depicted on the UI. For example, element 820 specifies that a door node is to be edited with a “doorEditPart” (i.e., the class name for this edit part is “com.ibm.sample.doorEditPart”) and that a “doorFigure” graphic will be used to visually depict a door (i.e., the class name for this figure is “com.ibm.sample.doorFigure”).
[0069] A <commonLinkDescriptor> element 890 then specifies which node elements can be linked to a house node (at <permissionConstraints> 891 ), and which cannot (at <prohibitionConstraints> 892 ). Thus, in this example, a house node can be linked to nodes for other houses (see 891 ), but not to nodes for doors, windows, beds, chairs, desks, sofas, or tables (see 892 ).
[0070] FIG. 9 depicts, in UML notation, the Visual Model Descriptor Meta-model exemplified by FIG. 8 . This figure indicates, for example, that the descriptor element for a node, “CommonNodeDescriptor” 930 , is related by a one-to-many relationship to “LinkCardinalityConstraint” elements 920 that may be input 921 or output 922 constraints (i.e., “inputConstraints” or “outputConstraints” elements). This is illustrated in the sample descriptor of FIG. 8 at 819 , where input constraints are specified for the house node identified at element 810 . As another example, FIG. 9 also indicates that the descriptor element for a link, “CommonLinkDescriptor” 940 , may have child elements that are “permissionConstraints” 951 or “prohibitionConstraints” 952 elements. This is illustrated in the sample descriptor of FIG. 8 at link description 890 and its child permission constraints element 891 and prohibition constraints element 892 .
[0071] According to preferred embodiments, a visual model descriptor (such as that shown at 800 in FIG. 8 ) is registered by a descriptor registry (as mentioned earlier with reference to 105 , 106 , 110 of FIG. 1 ) and read into the common graphical editor 135 at the time the editor 135 starts. The loose coupling between the visual model element properties and the visual model elements facilitates the reuse of the visual representation information, like icons and figure classes, and the editing properties like control classes and constraints. The descriptor registry 110 provides the flexibility of configuring the editing behaviors of an editor 135 by externally updating the visual model descriptor file 105 and the editor layout (such as background color, palette content, etc.) of an editor by externally updating the graphical editor descriptor file 115 , without affecting the program code itself.
[0072] A visual model descriptor such as descriptor 800 can (optionally) specify the type of the domain models that is represented by the common visual model. (Because of the loose coupling that is possible between domain and visual models, usually it is not necessary for visual model descriptors to identify a particular type of domain model.) One type of visual model can be used to represent different types of domain objects. For example, a common node model can be used to represent an employee with the person's photo, or used to represent a company with the company's logo. In terms of graphical editing, both the employee instances and the company instance interface the same way with the editor (e.g., by enabling a user to drag and drop the employee photos as well as the company logo). By configuring the descriptors, the two instances can have different editing behaviors. For example, a descriptor may specify that one-to-many links can be established from the instance representing the company to the instances representing employees, while the employee instances might be limited to one-to-one references to the company instance. Thus, the editor may prevent a user from associating a particular employee photo with more than one company logo while allowing the company logo to be linked to multiple employee photos.
[0073] Referring now to FIG. 10 , a sequence diagram illustrates how visual model elements may be created according to preferred embodiments. (Reference numbers are provided, when describing FIG. 10 , to the corresponding components in FIG. 1 . Note that the term “Visual Model Descriptor” is used herein to refer to the collection of all descriptors used for visual models. “CommonDescriptor”, shown in the heading of FIG. 10 , is one type of these descriptors. “DescriptorFactory” and “VisualModelFactory” in the heading of FIG. 10 refer to utilities for object instance creation. In preferred embodiments, these utilities perform a number of routine object creation tasks, such as inserting creation timestamps, validating that there are no duplicate identifiers, and so forth.)
[0074] A Common Graphical Editor Factory 130 is responsible for creating a Common Graphical Editor 135 . When a Common Visual Model descriptor 140 is read by a graphical editor application, this Common Visual Model descriptor is passed to the Common Graphical Editor Factory 130 . By reference to the header information of the Common Visual Model descriptor, the Factory locates the path of the structural file 105 of the Visual Model Descriptor. (See, for example, the header information specified at 711 and 713 in FIG. 7 , which references the descriptor 810 in FIG. 8 .) Using this information, the Factory then creates an instance 125 of the Visual Model Descriptor. The Factory also creates the Common Graphical Editor instance 135 . The Factory then passes the Visual Model Descriptor 125 , Common Visual Model 145 , and the Graphical Editor Descriptor 115 (which is the configuration information of the Editor) to the Common Graphical Editor 135 .
[0075] In preferred embodiments, Common Graphical Editor 135 is a default editor which is designed to accommodate the concepts of Common Visual Model 145 and Visual Model Descriptor 125 . A Common Graphical Editor is created and instantiated by Common Graphical Editor Factory with the Graphical Editor Descriptor, as is Visual Model Descriptor which can be seen as a meta-model of the Common Visual Model. (Refer also to Block 230 of FIG. 2 , where this was discussed briefly.)
[0076] Note that associating the visual model with a domain object can be the final step in this process, as shown by “setDomainObject” at the bottom of FIG. 10 .
[0077] Descriptor Registry 110 is a registry for Visual Model Descriptor 105 and Graphical Editor Descriptor 115 . In preferred embodiments, the registry comprises a data structure (such as a table) which maps a specific key to the path of the Visual Model Descriptor and the path of Graphical Editor Descriptor. For example, an entry in this data structure may be structured as shown by this sample triplet:
[0078] (Key_Value, Visual_Model_Descriptor_path, Graphical_Editor Descriptor_path)
[0000] A unique value for this key can be constructed in a number of ways, including based on a unique file name or a unique file extension, without deviating from the scope of the present invention.
[0079] Referring now to FIG. 11 , a flowchart is provided showing a sample scenario of using a preferred embodiment of the invention. As shown therein, a business analyst provides a domain model on which the graphical editor will be based (Block 1100 ). A usability analyst outlines the usability requirements for the elements of this domain model (Block 1105 ). Note that because of the loose coupling between domain model and visual model, Blocks 1100 and 1105 may be iterative processes that may overlap in time.
[0080] While these analysts are refining the domain objects and requirements, a designer determines the visual model elements corresponding to the domain model elements (Block 1110 ), based on the tooling requirements, and designs the descriptors for the visual models in light of the usability requirements (Block 1115 ). A developer then creates the visual model descriptor file, defining the visual representation and editing properties for each descriptor, based on the requirements (Block 1120 ). In the first milestone, the developer may use existing pre-built parts to build the descriptor. The developer also creates a Graphical Editor Descriptor (Block 1125 ) or may alternatively use a pre-built, default Graphical Editor Descriptor that may be supplied with the Common Graphical Editor System.
[0081] At Block 1130 , the developer registers the descriptors to the Descriptor Registry. Next, the developer launches and runs the graphical editor for testing, thus completing the first milestone (Block 1135 ). The developer then releases the graphical editor to the usability analyst, looking for feedback (Block 1140 ). The usability analyst launches and reviews the graphical editor (Block 1145 ), and adds new requirements if necessary. Now the usability analyst is able to create the content of the visual model object (Block 1150 ). Using this visual model, the usability analyst is able to touch and feel the editor and modify requirements if necessary (Block 1155 ).
[0082] Block 1160 tests to see if the pre-built parts meet the requirements (including whether a required behavior is not supported by the pre-built parts). If not, then at Block 1165 , the developer uses a graphical application framework (for example, GEF) to build the necessary parts and incorporates those parts into the visual model descriptor. (GEF may be used as a foundation framework for implementing embodiments of the present invention, if desired.) For example, if the pre-built parts do not contain any figures deemed suitable for representing sofas in a house, a new part may be created and identified in node descriptor 870 of FIG. 8 .
[0083] Block 1170 tests to see if the domain model is ready to incorporate into the visual model. If so, then at Block 1175 , the developer incorporates the mapping of the domain model into the visual model descriptor. (In preferred embodiments, this mapping comprises the descriptor that specifies the class names of the edit parts, figures, and domain model; the file name of the icons; and so forth. See, for example, 810 , 820 , etc. in FIG. 8 .) The usability analyst may then perform additional testing with the editor to further refine requirements. As indicated at Block 1180 , the usability analyst and the editor developer interact with each other until the requirements are fulfilled and the editor is therefore considered complete. The process of FIG. 11 then ends (Block 1185 ).
[0084] As will be appreciated by one of skill in the art, embodiments of the present invention may be provided as (for example) methods, systems, and/or computer program products. The present invention may take the form of a computer program product which is embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and so forth) having computer-usable program code embodied therein.
[0085] The present invention has been described with reference to flow diagrams and/or block diagrams according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flow diagram flow or flows and/or block diagram block or blocks.
[0086] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flow diagram flow or flows and/or block diagram block or blocks.
[0087] The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flow diagram flow or flows and/or block diagram block or blocks.
[0088] While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims shall be construed to include preferred embodiments and all such variations and modifications as fall within the spirit and scope of the invention.
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Techniques for developing a graphical editor using an incremental development approach. Externally-stored descriptors are used to specify information on which a graphical editor engine operates to create a graphical editor. Developers can thus redefine the look and feel of the graphical editor by modifying these descriptors, effectively re-configuring the elements of visual models without changing the code of the graphical editor engine. Visual models for modeling a domain can be created and used, without first requiring the domain model to be defined.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to determining the level of fluid in a container and the like.
[0003] 2. Description of the Art Practices
[0004] U.S. Pat. No. 5,655,839 issued to Schmidt, et al. Aug. 12, 1997 describes an IR temperature sensor that comprises a sealed housing containing an inert gas atmosphere and enclosing a detector for conversion of heat radiation into an electrical signal, an optical system which images the heat radiation emanating from an object onto the detector, a heat-conducting temperature equalization element which maintains the detector and the optical system at a common temperature, and a temperature sensor which measures the temperature of the temperature equalization element. The sealed housing protects the sensor from the external environment and maintains uniform temperature between the optical system and the sensor.
[0005] Further information concerning infrared temperature sensors is found in a brochure entitled Raynger® ST™ that describes ST30 Pro™ Standard and ST30 Pro™ Enhanced noncontact thermometers. The ST30 Pro™ Standard and ST30 Pro™ Enhanced noncontact thermometers are available from Raytek Corporation 1201 Shaffer Road Post Office Box 1820 Santa Cruz, Calif. 95061-1820.
[0006] U.S. Pat. No. 4,362,645 that issued to Hof, et al. Dec. 7, 1982 describes temperature-indicating compositions of matter. U.S. Pat. No. 4,362,645, in particular describes stable compositions of matter which change color sharply upon a transition from a liquid state to a solid state or from a solid state to a liquid state, which change of state is at substantially a predetermined temperature corresponding to a temperature to be measured.
[0007] The constituents of the Hof, et al. compositions of matter comprise: 1. a solvent (I) consisting of a single substance or a mixture of substances and adapted to change from a solid state at substantially a predetermined temperature to a liquid state and 2. an indicator system (II) consisting of one or more substances different from (I), characterized in that (a) (II) is soluble in (I) when the latter is in the liquid phase, and (b) (II) changes color visible to the naked eye when (I) passes from the solid to the liquid phase or from the liquid to the solid phase. Thermometers containing said stable compositions of matter are also disclosed.
[0008] U.S. Pat. No. 4,339,207 also to Hof, et al. which issued Jul. 13, 1982 describes a temperature indicating device is disclosed comprising: (a) a flat or gradually curved heat-conducting carrier having one or more cavities, each substantially filled with a composition of matter; or in the alternative, with (1) a composition of matter which changes from opaque to transparent upon a corresponding change from solid to liquid on top of an (2) indicator means located at the bottom of the cavity; said composition of matter, whether novel or not, being substantially without impurities and containing a substantially spherical void space between the bottom of the cavity; and (b) a transparent cover sheet means in sealing engagement with the heat conducting carrier means overlying and above the cavity, which spherical void space acts to magnify the color change if the novel compositions of matter are present or the presence of an indicator means upon melting of the compositions of matter in the cavity.
[0009] The compositions of matter of Hof et al., are further described as changing color sharply upon a transition from a liquid state to a solid state or from a solid state to a liquid state, which change of state is at substantially a predetermined temperature corresponding to a temperature to be measured.
[0010] U.S. Pat. No. 4,232,552 issued to Hof, et al. Nov. 11, 1980 discloses temperature-indicating compositions of matter. The Hof, et al. compositions Novel and stable compositions of matter are disclosed which change color sharply upon a transition from a liquid state to a solid state or from a solid state to a liquid state, which change of state is at substantially a predetermined temperature corresponding to a temperature to be measured. The constituents of the novel compositions of matter comprise: 1. a solvent (I) consisting of a single substance or a mixture of substances and adapted to change from a solid state at substantially a predetermined temperature to a liquid state and 2. an indicator system (II) consisting of one or more substances different from (I), characterized in that (a) (II) is soluble in (I) when the latter is in the liquid phase, and (b) (II) changes color visible to the naked eye when (I) passes from the solid to the liquid phase or from the liquid to the solid phase. Thermometers containing stable compositions of matter are also disclosed in U.S. Pat. No. 4,232,552.
[0011] Seiden, et al., in U.S. Pat. No. 5,426,593 issued Jun. 20, 1995 is directed to a device which measures the oxygen component of a beverage gas using a specific oxygen probe, ultrasonic degassing, a special valving technique, and microprocessor based software. The measurement is made in the gaseous state in a two-chamber system.
[0012] The device of Seiden, et al., is controlled by an electronic console that is built around a microprocessor which sequences and times the valves, receives the data from the oxygen probe and its accompanying temperature compensation circuit, and displays the data. An alternative method is to use several chambers and one pass. Additional chambers may be used to increase the speed of the test, control interferences, or aid in identifying gases other than the oxygen component. The device may also have an interface piercing head manifold that allows carbon dioxide and oxygen to be tested in the same container and in one preparation. The invention also relates to specific gas measurements with non-specific type measurements and the general techniques can be applied to environmental problems that involve oxygen demand and respir-ation of bacteria.
[0013] U.S. Pat. No. 6,119,464 issued to Nakayama, et al. on Sep. 19, 2000 describes beverage servers and controlling methods for beverage servers. More particularly, Nakayama, et al. discloses a beverage server comprising a tank containing water serving as a coolant and a coiled beverage duct through which beer or other beverage flows and cooling means fitted to a portion of the wall of the tank so as to rapidly cool and serve beer or other beverage discharged from the storage container. The inner wall of the tank near the portion where the cooling means is fitted is made of a material having a high thermal conductivity, whereas the inner wall of the tank near the beverage duct is made of a material having a low thermal conductivity. A sensor is provided near the beverage duct to obtain information for controlling the cooling means. This simple beverage server assures stable serving of beverage at a suitable temperature. Another sensor is provided near a portion of the tank wall where the cooling means and a controller to controls the action of the cooling means based on the information from the sensors are also provided. The cooling means works at full capacity when one or both of the sensors have detected the melting of the coolant. This eliminates the risk of trouble due to cooling capacity deficiency even after a long interruption of cooling.
[0014] Furuhashi, et al., in U.S. Pat. No. 5,165,569 issued Nov. 24, 1992 recites a keg body for retaining draft beer substantially has adiabatic structure, in which draft beer filled in the keg body is kept cool. A part of the keg body is provided with a face which is not heat-insulated and this face is utilized as a cooling face. In case of necessity, beer is cooled from the outside through the cooling face to keep cool draft beer inside the keg body.
[0015] To the extent that the foregoing patents are relevant to the present invention they are herein incorporated by reference. Temperatures herein are given in degrees Fahrenheit and pressures are in gauge Kpa. Ratios and ranges may be combined.
SUMMARY OF THE INVENTION
[0016] The present invention describes a method for determining the level of fluid in a container comprising:
[0017] obtaining a container having a first fluid region therein;
[0018] a first fluid being present at an original level in said first fluid region of said container;
[0019] said container, for when in use, having said first fluid at least partially removed from said container thereby forming a second fluid region;
[0020] placing on at least one exterior surface of said container at least one temperature-measuring device;
[0021] at least one said temperature-measuring device being located in a region of said container where said second fluid region is formed by removal of said first fluid;
[0022] initially observing a first temperature in said first fluid region of said container when said first fluid is present in said first fluid region of said container;
[0023] subsequently observing a second temperature in said second fluid region of said container after a potion of said first fluid has been removed;
[0024] correlating the difference between said first temperature and said second temperature to the level of said first fluid in said container.
[0025] Yet another aspect of the invention is a fluid dispensing assembly comprising:
[0026] a sealed container, for when in use, containing a liquid under pressure;
[0027] said sealed container having an exterior surface;
[0028] said exterior surface of said sealed container having a heightwise dimension and a widthwise dimension; and
[0029] at least one temperature-measuring device positioned on said heightwise dimension of said exterior surface.
[0030] Another aspect of the invention is a fluid dispensing assembly comprising:
[0031] a sealed metal beer barrel, for when in use, containing beer under pressure;
[0032] said metal beer barrel having an exterior surface;
[0033] said exterior surface of said metal beer barrel having a heightwise dimension and a generally circular cross-sectional dimension; and
[0034] at least one temperature-measuring device positioned on said heightwise dimension of said exterior surface of said metal beer barrel.
[0035] Yet another embodiment of present invention is a temperature-measuring device mounted on a flexible band.
[0036] A further embodiment of present invention is a method of obtaining the level of a liquid or a gas in a container including the steps of:
[0037] obtaining the temperature at a selected region of said container containing said liquid or said gas;
[0038] comparing the temperature at said selected region of said container with a profile of temperatures corresponding to a liquid level of said fluid in a vessel and the temperature corresponding to a gas level in the vessel; and,
[0039] determining whether the temperature in said container indicates the level of said liquid or said gas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon consideration of the following description of the invention with reference to the accompanying drawings, wherein:
[0041] [0041]FIG. 1 is a partial cross-sectional perspective view showing a first embodiment of a beer keg of the invention;
[0042] [0042]FIG. 2 is a longitudinally cross-sectional view showing a beer keg having draft beer in the beer keg;
[0043] [0043]FIG. 3 is a view showing a beer keg;
[0044] [0044]FIG. 4 is a thermometric fastening device according to the invention; and,
[0045] [0045]FIG. 5 is a view of another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0046] In FIG. 1, a beer keg 1 according to a first embodiment of the invention is shown. The beer keg 1 is generally cylindrical.
[0047] As shown in FIG. 2, the beer keg 1 is a container made of thin stainless steel plate, and having a mouthpiece 2 and a bottom. The beer keg 1 is prepared by welding an inner cylinder upper plate 3 , the outer cylinder shell 6 , and an outer cylinder lower plate 9 .
[0048] The outer cylinder shell 6 is in a cylindrical form and is integrally sealed, at its upper and lower edges with the inner cylinder plate 3 and the outer cylinder plate 9 , respectively, by TIG welding. In this embodiment, the mouth piece 2 is mounted on the center of the inner cylinder plate 3 . A down tube 13 shown in FIG. 3 is inserted into the beer keg 1 through the mouth piece 2 .
[0049] The down tube 13 is a tube for providing draft beer into the inside of the beer keg 1 and also ejecting draft beer from the beer keg 1 . The down tube 13 has a carbon dioxide-valve (not shown) and a beer valve (not shown) and is screwed in the mouthpiece to be fixed.
[0050] The keg outer cylinder 6 is formed of an outer cylinder shell 8 and an outer cylinder lower plate 9 . The outer cylinder shell 8 has an upper grip 7 at its upper opening edge and a keg leg 10 at its lower opening edge, respectively. Both upper and lower edges are bent inwardly. The diameter of the upper edge is slightly smaller than that of the lower edge, but the upper and lower portions of the outer cylinder shell 8 may be reversible upside down.
[0051] At the proper standing posture of the outer-cylinder shell 8 , the upper edge acts as the upper grip 7 and the lower edge operates as the keg leg 10 . At the inverted posture thereof, the upper edge acts as the keg leg 10 and the lower edge acts as the upper grip 7 .
[0052] A\ shown in FIG. 1, a plurality of thermometric measuring devices 12 are provided on the outer cylinder shell 8 . The thermometric measuring devices 12 are designated as 12 A, 12 B, 12 C, and 12 D. The thermometric measuring devices 12 are so designated by the appended letter to show the location on the keg outer cylinder 6 .
[0053] Several eutectic materials are disclosed in U.S. Pat. No. 4,362,645 that issued to Hof, et al. Dec. 7, 1982 as well as the remaining cited Hof, et al. patents. Similar eutectic may be formulated from foregoing disclosures to provide a suitable temperature range for determining the temperature within a container such as a beer barrel.
[0054] The thermometric measuring devices 12 are first located along the height of the keg outer cylinder 6 and generally correspond to a level of 10 percent of maximum fluid content of the beer keg 1 , 25 percent of maximum fluid content of the beer keg 1 , and 75 percent of maximum fluid content of the beer keg 1 . Alternatively, thermometric measuring devices 12 are conveniently located at a point from 5% to 35% of the maximum original fluid level in said first fluid region of said container.
[0055] The thermometric measuring devices 12 are also located circumferentially around the keg outer cylinder 6 . Conveniently, the thermometric measuring devices 12 located around the circumference of the keg outer cylinder 6 are two, three, four, five, six, seven, or eight in number.
[0056] The thermometric measuring devices 12 located around the circumference of the keg outer cylinder 6 are to aid in the determination of fluid level. As the beer kegs are quite heavy and when tapped with associated piping the movement of beer kegs is difficult. Also the movement of the beer kegs into a cooler of confined dimensions makes it difficult to move the kegs within a cooler. Accordingly, a plurality of thermometric measuring devices 12 makes it easier to see at least one of the thermometric measuring devices 12 .
[0057] When for example, there are two of the thermometric measuring devices 12 circumferentially located on the keg outer cylinder 6 either of the two the thermometric measuring devices 12 may be read. If there are three of the thermometric measuring devices 12 circumferentially located on the keg outer cylinder 6 and each is located approximately 120 degrees apart it will be easier to see at least one of the thermometric measuring devices 12 .
[0058] The thermometric measuring devices 12 are conveniently placed in as close a contact as is possible with keg outer cylinder 6 . The thermometric measuring devices 12 may be adhesive backed to permit relatively intimate contact with the keg outer cylinder 6 . Alternatively, the thermometric measuring devices 12 may be affixed to the keg outer cylinder 6 by means of a transparent pressure sensitive adhesive tape (not shown). The transparent pressure sensitive adhesive tape permits viewing of the thermometric measuring devices 12 to determine the temperature and accordingly the volume level of the beer keg 1 .
[0059] The outer cylinder lower plate 9 is provided with a nozzle 11 having a valve. After the valve is opened and the nozzle 11 is connected to a vacuum pump (not shown) air or liquid in the beer keg 1 is removed. In this manner the beer keg 1 may be cleaned. Then, the valve is then closed to permit filling of the beer keg 1 .
[0060] In a brewery, there is a line where a beer keg 1 incorporated with the down tube 13 is automatically washed and draft beer is automatically filled in the beer keg 1 . Similarly, the beer keg 1 of the present invention is automatically washed and filled with draft beer by using the above-mentioned line. The beer keg 1 filled with the draft beer is stored in a refrigerator for shipping to forcibly cool beer in the beer keg 1 through the face Cz. In shipping, as shown in FIG. 3, the upper face of the inner cylinder upper plate 3 of the beer keg 1 is covered with an adiabatic mat 14 to keep low temperature. The beer keg 1 is kept in a proper standing posture, so that temperature of draft beer filled in the beer keg 1 does not substantially rise due to the fact that draft beer is heat-insulated by the vacuum layer between the beer keg 1 and the outer cylinder shell 8 . After the beer keg 1 of the present invention is supplied to and stored in a tavern, beer is kept cool in a refrigerator in an inverted posture or horizontal posture. Draft beer is cooled through the face Cz of the inner cylinder upper plate 3 , so that the draft beer can be effectively forcibly cooled.
[0061] In the beer keg 1 described in the present invention, the upper end hole of the outer-cylinder shell 8 is reduced in diameter to be smaller than the lower end hole, but either one of the upper and lower edges of the outer cylinder shell 8 becomes a grip or keg leg, so that the beer keg 1 can be placed without distinguishing upper and lower portions. On sale of draft beer at a tavern, beer is supplied in a conventional manner to a pitcher and so on through the down tube 13 while carbon dioxide is injected with pressure, wherein the beer keg 1 is vertically positioned to locate the mouth piece upwardly. To keep the draft beer cool during the sale is made by inserting a cooling agent a between the adiabatic mat 14 and the inner cylinder upper plate 3 .
[0062] As best seen in FIG. 4, is a temperature-measuring device 40 mounted on a flexible band 44 . The temperature-measuring device 40 is conveniently secured to a flexible band 44 such that the thermally sensitive portion of the temperature-measuring device 40 may be exposed to the outer side of a beer barrel. The temperature-measuring device 40 is conveniently insulated so that the ambient temperature such as in a region of low humidity as a refrigerator or refrigerator compartment will not interfere with the temperature-measurement and thus determination of level of fluid in the beer barrel.
[0063] The flexible band 44 may be an endless band such as formed form an elastomeric material. In a preferred embodiment, the flexible band 44 is a non-endless belt that is secured with a hook 52 and eye 54 fastener (Velcro).
[0064] As best seen in FIG. 5 is a conventional mercury thermometer 70 . The mercury thermometer 70 to a beer barrel. A small amount of an insulating material 72 is placed on the ball of the thermometer to ensure that is the temperature of the beer barrel and not the ambient temperature in the refrigerator that is observed.
[0065] In use, as best seen in FIG. 2, is the level of beer 80 in a beer keg 1 . It is observed that the beer 80 within the beer keg 1 has excellent heat flow characteristics when compared to the gas in the headspace out of the liquid level of the beer. As the beer 80 is withdrawn from the beer keg 1 through the down tube 13 , increased headspace occurs. The gas in the headspace will typically be warmer than the liquid in the beer keg 1 . As such a temperature-measurement in the region of that headspace will result in a higher temperature than that in the liquid.
[0066] As best seen in FIG. 3, as the beer 80 is drawn from the level of 12 D to 12 C the heat flow characteristics will cause the thermometric measuring device 12 D to increase in temperature and to change color. The thermometric measuring device 12 C will maintain its temperature and not change color until the liquid level drops to the region below thermometric measuring device 12 C.
[0067] As the tavern owner will desire to know only the level of various kegs of beer it is possible to make such determination by observing where the colder temperature region of the beer keg is located. Thus, when the temperature of the beer keg 1 indicates that the colder temperature is only at the lower 10 percent of the beer keg 1 it is easily determined that the beer keg 1 should be changed prior to a busy evening. Of course, the temperature indicator on the beer keg 1 is also more than adequate to determine which are kegs are of sufficiently low temperature from which to serve the beer. The present invention also provides an opportunity for loss prevention or inventory control by tavern keeper.
[0068] In a situation where the mercury thermometer is utilized, the thermometer may be moved around on the beer keg 1 . The present invention may also utilize the eutectic strips to determine during the course of the evening as to how far the beer has been depleted.
[0069] As the one further embodiment, is possible to utilize an infrared thermometric device to make the determination of level of liquid in the beer keg 1 . However, it is preferred that the thermometric temperature-measuring device be permanently affixed to the container so that it is readily available for the determination of volume and temperature.
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The present invention deals with determining the level of fluid in a container. Typically, a beverage container containing a liquid will absorb heat energy from the surrounding environment at a greater rate than a gaseous component in the headspace of the beverage container. Thus, as the liquid is drawn from a beverage container a greater headspace results. If a thermometric measuring device is employed along the height of the beverage container the volume may be determined by observing the difference in the temperature along the height of the beverage container. In practice, a beer keg may exhibit a difference of as much as 9 degrees Fahrenheit on the exterior surface of the beer keg when measured at the headspace as opposed to the area where the liquid is present in the beverage container.
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[0001] This application is related to allowed co-owned application Ser. No. 09/327,707 filed Jun. 9, 1999, Ser. No. 08/729,752 filed Oct. 7, 1996, now U.S. Pat. No. 5,910,647, and Ser. No. 08/489,365 filed Jun. 12, 1995, now U.S. Pat. No. 5,663,531, the complete disclosures of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to electronic weighing devices. More particularly, the invention relates to an electronic weighing device which employs surface acoustic waves to measure weight.
[0004] 2. State of the Art
[0005] Precision electronic weighing devices are widely known in the art and there are many different technologies utilized in these electronic weighing devices. Laboratory scales or “balances” typically have a capacity of about 1,200 grams and a resolution of about 0.1 gram, although scales with the same resolution and a range of 30,000 grams are available. The accuracy of these scales is achieved through the use of a technology known as magnetic force restoration. Generally, magnetic force restoration involves the use of an electromagnet to oppose the weight on the scale platform. The greater the weight on the platform, the greater the electrical current needed to maintain the weight. While these scales are very accurate (up to one part in 120,000), they are expensive and very sensitive to ambient temperature. In addition, their range is relatively limited.
[0006] Most all other electronic weighing devices use load cell technology. In load cell scales, the applied weight bends an elastic member which has strain gauges bonded to its surface. The strain gauge is a fine wire which undergoes a change in electrical resistance when it is either stretched or compressed. A measurement of this change in resistance yields a measure of the applied weight. Load cell scales are used in non-critical weighing operations and usually have a resolution of about one part in 3,000. The maximum resolution available in a load cell scale is about one part in 10,000 which is insufficient for many critical weighing operations. However, load cell scales can have a capacity of several thousand pounds.
[0007] While there have been many improvements in electronic weighing apparatus, there remains a current need for electronic weighing apparatus which have enhanced accuracy, expanded range, and low cost.
[0008] The previously incorporated applications disclose an electronic weighing apparatus having a base which supports a cantilevered elastic member upon which a load platform is mounted. The free end of the elastic member is provided with a first piezoelectric transducer and a second piezoelectric transducer is supported by the base. Each transducer includes a substantially rectangular piezoelectric substrate and a pair of electrodes imprinted on the substrate at one end thereof, with one pair of electrodes acting as a transmitter and the other pair of electrodes acting as a receiver. The transducers are arranged with their substrates substantially parallel to each other with a small gap between them and with their respective electrodes in relatively opposite positions. The receiver electrodes of the second transducer are coupled to the input of an amplifier and the output of the amplifier is coupled to the transmitter electrodes of the first transducer. The transducers form a “delay line” and the resulting circuit of the delay line and the amplifier is a positive feedback loop, i.e. a natural oscillator. More particularly, the output of the amplifier causes the first transducer to emit a surface acoustic wave (“SAW”) which propagates along the surface of the first transducer substrate away from its electrodes. The propagating waves in the first transducer induce an oscillating electric field in the substrate which in turn induces similar SAW waves on the surface of the second transducer substrate which propagate in the same direction along the surface of the second transducer substrate toward the electrodes of the second transducer. The induced waves in the second transducer cause it to produce an alternating voltage which is supplied by the electrodes of the second transducer to the amplifier input. The circuit acts as a natural oscillator, with the output of the amplifier having a particular frequency which depends on the physical characteristics of the transducers and their distance from each other, as well as the distance between the respective electrodes of the transducers.
[0009] When a load is applied to the load platform, the free end of the cantilevered elastic member moves and causes the first transducer to move relative to the second transducer. The movement of the first transducer relative to the second transducer causes a change in the frequency at the output of the amplifier. The movement of the elastic member is proportional to the weight of the applied load and the frequency and/or change in frequency at the output of the amplifier can be calibrated to the displacement of the elastic member. The frequency response of the delay line is represented by a series of lobes. Each mode of oscillation is defined as a frequency where the sum of the phases in the oscillator is an integer multiple of 27. Thus, as the frequency of the oscillator changes, the modes of oscillation move through the frequency response curve and are separated from each other by a phase shift of 2X. The mode at which the oscillator will most naturally oscillate is the one having the least loss. The transducers are arranged such that their displacement over the weight range of the weighing apparatus causes the oscillator to oscillate in more than one mode. Therefore, the change in frequency of the oscillator as plotted against displacement of the transducers is a periodic function. There are several different ways of determining the cycle of the periodic function so that the exact displacement of the elastic member may be determined.
[0010] It is generally known in the art of SAW technology that the frequency range in which the losses are the lowest is not necessarily the frequency range in which the oscillator exhibits the best phase linearity. From the teachings of the previously incorporated applications, those skilled in the art will appreciate that in a SAW displacement transducer such as disclosed in the previously incorporated applications, better phase linearity provides a more linear relationship between frequency and displacement. In the case of a weighing apparatus using a SAW displacement transducer as described in the previously incorporated applications, better phase linearity will result in a more linear relationship between weight and frequency.
[0011] It is known in the art of SAW oscillators that changing the topology of the oscillator transmitter and receiver can cause a broader bandwidth of the delay line and that a broader bandwidth results in better phase linearity. It is also known that using a smaller frequency range provides better linearity and that a smaller frequency range can be obtained with a longer delay line. Although these known methods can increase phase linearity in a SAW oscillator, the frequency range in which the best linearity is achieved for a particular oscillator is still not necessarily the range with the lowest losses.
[0012] From the foregoing, those skilled in the art will appreciate that in order to enhance the accuracy of a SAW displacement transducer such as that used in a weighing device, it would be desirable to cause the SAW oscillator to oscillate in the range having the best phase linearity.
[0013] As disclosed in the previously incorporated applications, weighing accuracy is affected by temperature. The previously incorporated applications disclose a SAW temperature oscillator having a transmitter and receiver on the same substrate. The temperature sensitivity of the load cell disclosed in the previously incorporated applications is approximately 500 ppm of the weight reading per 1° C. temperature change. Accuracy of 100 ppm of the weight reading can be achieved if temperature is measured to within 0.2° C. which represents a shift of about 1 kHz of the SAW temperature sensor. This shift is easy to measure in the short term. The resolution of the SAW temperature sensor is on the order of 0.001° C. However, the long term stability of the SAW temperature sensor can drift more than 1 kHz due to many factors including humidity
[0014] It will also be appreciated that temperature changes can make determination of mode of oscillation more difficult. In the previously incorporated applications, mode determination was determined by switching the phase ±π and noting the frequency change. However, factors such as temperature and non-linearity can make the frequency change very small thereby making the mode determination unreliable
SUMMARY OF THE INVENTION
[0015] It is therefore an object of the invention to provide an electronic weighing apparatus which is accurate.
[0016] It is also an object of the invention to provide an electronic weighing apparatus which uses surface acoustic waves and is accurate over a broad range of weights.
[0017] It is another object of the invention to provide an electronic weighing apparatus which is compact and easy to construct.
[0018] It is a further object of the invention to provide an electronic weighing apparatus which is inexpensive to manufacture.
[0019] It is another object of the invention to provide an electronic weighing apparatus which utilizes surface acoustic waves and which has enhanced phase linearity.
[0020] It is still another object of the invention to provide an electronic weighing apparatus which utilizes surface acoustic waves and which is oscillates in the mode of best phase linearity.
[0021] It is yet another object of the invention to provide an electronic weighing apparatus which utilizes surface acoustic waves and has long term temperature stability as well as short term temperature stability.
[0022] In accord with these objects which will be discussed in detail below, the improved weighing apparatus of the present invention includes a base which supports a cantilevered elastic member upon which a load platform is mounted. The interior of the elastic member is hollowed and is provided with first and second piezoelectric transducers which are mounted on respective opposed posts. Each transducer includes a substantially rectangular piezoelectric substrate and a pair of electrodes imprinted on the substrate at one end thereof, with one pair of electrodes acting as a transmitter and the other pair of electrodes acting as a receiver. The transducers are arranged with their substrates substantially parallel to each other with a small gap between them and with their respective electrodes in relatively opposite positions. The receiver electrodes of the second transducer are coupled to the input of an amplifier and the output of the amplifier is coupled to the transmitter electrodes of the first transducer. The transducers form a “delay line” and the resulting circuit of the delay line and the amplifier is a positive feedback loop, i.e. a natural oscillator. More particularly, the output of the amplifier causes the first transducer to emit a surface acoustic wave (“SAW”) which propagates along the surface of the first transducer substrate away from its electrodes. The propagating waves in the first transducer induce an oscillating electric field in the substrate which in turn induces similar SAW waves on the surface of the second transducer substrate which propagate in the same direction along the surface of the second transducer substrate toward the electrodes of the second transducer. The induced waves in the second transducer cause it to produce an alternating voltage which is supplied by the electrodes of the second transducer to the amplifier input. The circuit acts as a natural oscillator, with the output of the amplifier having a particular frequency which depends on the physical characteristics of the transducers and their distance from each other, as well as the distance between the respective electrodes of the transducers.
[0023] According to the invention, when a load is applied to the load platform, the cantilevered elastic member bends and causes the first transducer to move relative to the second transducer. The movement of the first transducer relative to the second transducer causes a change in the frequency at the output of the amplifier. The bending movement of the elastic member is proportional to the weight of the applied load and the frequency and/or change in frequency at the output of the amplifier can be calibrated to the displacement of the elastic member.
[0024] According to one aspect of the invention, a “push oscillator” is coupled to the delay line for injecting a strong RF signal at a frequency in the middle of the oscillation mode which exhibits the best phase linearity. The frequency of the “push oscillator” is determined experimentally when the scale is calibrated. The RF signal is injected periodically in short bursts.
[0025] According to a second aspect of the invention, the “push oscillator” frequency is generated by mixing the temperature oscillator with an adjustable fixed frequency oscillator. This immunizes the “push oscillator” from the affects of temperature.
[0026] According to a third aspect of the invention, a thermistor is provided for long term temperature stability. The SAW temperature sensor is periodically calibrated to the thermistor.
[0027] According to a fourth aspect of the invention, the SAW oscillators are not hermetically sealed and the SAW temperature sensor is used to correct the displacement sensor for changes in humidity.
[0028] According to a fifth aspect, a single amplifier is used to power two SAW sensors (e.g. a weight sensor and a temperature sensor) which oscillate at different frequencies.
[0029] According to a sixth aspect of the invention, a crystal oscillator is used to compensate the push oscillator for temperature changes.
[0030] According to a seventh aspect of the invention, two SAW weight sensors are provided where each oscillates at a different frequency.
[0031] Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] [0032]FIG. 1 is a schematic side elevation view of an exemplary embodiment of the invention;
[0033] [0033]FIG. 1 a is an enlarged schematic plan view of a first transducer;
[0034] [0034]FIG. 1 b is an enlarged schematic plan view of a second transducer;
[0035] [0035]FIG. 2 is an enlarged schematic side elevation view of a transducer having anti-reflection structure according to the invention;
[0036] [0036]FIG. 3 is an enlarged schematic side elevation view of a pair of transducers according to the invention;
[0037] [0037]FIGS. 4 and 5 are graphs of a portion of a frequency response curve for a delay line according to the invention showing modes of oscillation and phase shifting according to the invention;
[0038] [0038]FIG. 6 is a simplified schematic diagram of circuits used in the weighing device according to the invention;
[0039] [0039]FIG. 7 is a simplified schematic diagram of a circuit wherein two SAW sensors are powered by a single amplifier;
[0040] [0040]FIG. 8 is a simplified schematic diagram of a circuit used to compensate the push oscillator for temperature;
[0041] [0041]FIG. 9 illustrates the frequency shift of two displacement sensors having different frequencies; and
[0042] [0042]FIG. 10 illustrates the frequency shift of two displacement sensors having different frequencies and arranged in a differential manner.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Referring now to FIGS. 1, 1 a , and 1 b , an electronic weighing apparatus 10 according to the invention includes a base 12 which supports a cantilevered elastic member 14 having a cut-out 15 , and upon which a load platform 16 is mounted. The cut-out 15 is provided with two opposed posts 17 , 19 upon which are respectively mounted a first piezoelectric transducer 20 and a second piezoelectric transducer 22 . The posts 17 , 19 serve to locate the transducers 20 , 22 at the center of the elastic member 14 and to mechanically couple the transducers to opposite ends of the elastic member 14 .
[0044] The first transducer 20 includes a substantially rectangular piezoelectric substrate 20 a and a pair of electrodes 20 b imprinted on the substrate at the upper end thereof. The second transducer 22 includes a substantially rectangular piezoelectric substrate 22 a and a pair of electrodes 22 b imprinted on the substrate at the lower end thereof. The substrates are preferably made of Lithium Niobate. The transducers are arranged with their substrates substantially parallel to each other with a small gap “g” between them. The electrodes 22 b of the second transducer 22 are coupled to the input of an amplifier (not shown) powered by a power source (not shown) and the output of the amplifier is coupled to the electrodes 20 b of the first transducer 20 . The circuit arrangement is the same as shown in the previously incorporated application Ser. No. 08/489,365, previously incorporated herein by reference. The resulting circuit is a positive feedback loop natural oscillator, a “delay line”. The output of the amplifier generates an alternating voltage in the electrodes 20 b of the first transducer 20 which generates a surface acoustic wave (“SAW”) 26 which propagates along the surface of the first transducer substrate 20 a away from its electrodes 20 b . Since the substrate 20 a of the first transducer 20 is relatively close to the substrate 22 a of the second transducer 22 , an oscillating electric field which is induced as a result of the SAW waves 26 in the piezoelectric substrate 20 a is able to in turn induce similar SAW waves 28 on the surface of the second transducer substrate 22 a which propagate in the same direction along the surface of the second transducer substrate toward the electrodes 22 b of the second transducer 22 . The induced waves 28 in the second transducer 22 cause the electrode 22 b of the second transducer 22 to produce an alternating voltage which is provided to the input of the amplifier. As long as the gain of the amplifier 24 is larger than the loss of the system, the circuit acts as a natural oscillator with the output of the amplifier having a particular frequency which depends on the physical characteristics of the transducers and their distance from each other, as well as the distance between the respective electrodes of the transducers. In particular, the frequency of the oscillator is directly related to the time it takes for the SAW to propagate from the electrodes 20 b to the electrodes 22 b.
[0045] According to presently preferred embodiments of the invention, described in more detail below, the SAW 26 has a wavelength of approximately 100-200 microns at 20-50 MHz. In order to limit loss in the system, the gap “g” between the substrates of the first and second transducers is kept small. In one preferred embodiment described below, the gap is 10-20 microns. With such a gap, an oscillating system can typically be generated if the amplifier 24 has a gain of at least approximately 25 dB. It will be appreciated that when a load (not shown) is applied to the load platform 16 , the free end of the cantilevered elastic member 14 moves down and causes the second transducer 22 to move relative to the first transducer 20 . In particular, it causes the electrodes 22 b of the second transducer 22 to move away from the electrodes 20 b of the first transducer 20 . This results in a lengthening of the “delay line”. The lengthening of the delay line causes an decrease in the frequency at the output of the amplifier. The displacement of the elastic member is proportional to the weight of the applied load and the frequency or decrease in frequency at the output of the amplifier can be calibrated to the distance moved by the elastic member.
[0046] It will be appreciated that locating the transducers at the center of the elastic member compensates for any torque on the member which would exhibit itself at the free end of the member. This results in an improved accuracy as compared to the weighing instrument disclosed in U.S. Pat. No. 5,663,531. Depending on the application (e.g. maximum load to be weighed), the elastic member is made of aluminum or steel. The presently preferred elastic member exhibits a maximum displacement of 0.1 to 0.2 mm at maximum load.
[0047] Reflected waves may occur on both piezo substrates. Reflected waves interfere with the received signal. The interference causes an increase in non-linearity. FIGS. 2 and 3 show presently preferred anti-reflection structures according to the invention.
[0048] Turning now to FIGS. 2 and 3, presently preferred transducers 120 , 122 are shown. FIG. 2 illustrates the features of transducer 120 which is substantially identical to transducer 122 . FIG. 3 illustrates the transducers mounted on the posts 17 , 19 of the elastic member 14 of FIG. 1. As shown in FIG. 2, the transducer 120 includes a lithium niobate substrate 120 a with electrodes 120 b imprinted thereon. The ends 120 c , 120 d of the substrate are tapered and polyurethane dampers 121 a , 121 b are placed at the ends to minimize reflection of the SAW waves.
[0049] As mentioned above and in the previously incorporated application, the delay lines according to the invention may oscillate in more than one mode and within each mode, the gain will vary as the frequency changes. Referring now to FIGS. 4 and 5, in the idle state, with no weight applied to the scale, the delay line will oscillate at a frequency “f” which is shown in FIG. 4 as the point having the most gain (least loss). The optimal gain area of the graph of FIG. 4 is shown in the shaded area surrounding f and represents a range of ±100 Khz, for example. This area is considered optimal because it is the area of least loss. However, it is not necessarily the area of best phase linearity. After experimenting, it may be discovered that oscillation in a different mode, e.g. the shaded area of FIG. 5, will produce better phase linearity. According to one aspect of the invention, the oscillator is forced to oscillate in the mode of best phase linearity by injecting a strong RF signal having a frequency at the midpoint of the desired mode of oscillation. The RF signal is injected by a “push oscillator” coupled to the SAW wave receiver as described in more detail below with reference to FIG. 6. According to the presently preferred embodiment, the RF signal has a strength of approximately 100 mv as compared to the SAW oscillator's strength of approximately 10 mv. The RF signal is preferably injected for a short time (as short as 0.01 seconds) before each weight measurement.
[0050] As mentioned above, and described in detail in the previously incorporated applications, the effects of temperature can be further corrected by providing a separate SAW temperature sensor on the same substrate as one of the displacement transducers. According to the presently preferred embodiment, the SAW displacement oscillator operates at 55 MHz and the SAW temperature oscillator operates at 57 MHz. According to another aspect of the invention, described in more detail below with reference to FIG. 6, the temperature oscillator is used in conjunction with an adjustable 2 MHz oscillator and a mixer to produce the “push oscillator” frequency and automatically adjust the “push oscillator” frequency for temperature changes.
[0051] Turning now to FIG. 6, an exemplary circuit 200 according to the invention includes the displacement SAW transducer formed by the transmitter 122 b on the substrate 122 and the receiver 120 b on the substrate 120 coupled to each other by the amplifier 202 . In addition, the circuit includes a temperature SAW transducer formed by the transmitter 124 and receiver 126 on the substrate 122 coupled to each other by the amplifier 204 . The output of amplifier 202 is a frequency Fw which varies according to displacement of the substrates relative to each other, which is an indication of weight when the transducers are arranged as shown in FIG. 1. According to the presently preferred embodiment, the frequency Fw is nominally 54 MHz. Fw will also vary according to temperature. The output of amplifier 204 is a frequency Ft which varies only according to temperature and humidity and which is nominally 57 MHz. The frequencies Fw and Ft are mixed (subtracted) at the mixer 206 to produce a nominal frequency of 3 MHz which varies according to weight and which is temperature compensated. The output frequency of the mixer 206 is input to a microprocessor 208 which calculates weight as described in the previously incorporated applications and displays the weight on display 210 . According to the presently preferred embodiment, the output Ft of amplifier 204 is also mixed via mixer 212 with a 54 MHz signal from oscillator 214 to produce a signal which is nominally 3 MHz and which varies only with temperature and humidity. The signal Fw-Ft provides a temperature adjusted weight signal which accounts for the affects of temperature on the SAW oscillators. It does not compensate for temperature effects on the Youngs modulus of the elastic member ( 14 in FIG. 1). The signal output from mixer 212 is a pure temperature indicator and is used to adjust the weight calculation for the effects of temperature on the Youngs modulus of the elastic member.
[0052] According to one aspect of the present invention, a “push oscillator” is formed from an adjustable oscillator 216 , a mixer 218 , and a modulator 220 . The oscillator 216 has a nominal frequency of 2 MHz which is mixed via the mixer 218 with the output of amplifier 204 to produce an output frequency Fi which is (Ft—approx. 2 MHz). This frequency Fi is used to index the modulator 220 which produces the “push oscillator” output to the input of amplifier 202 . As shown in FIG. 6, the modulator 220 and the oscillator 216 are both coupled to the microprocessor 208 . The microprocessor 208 is programmed to periodically activate the modulator 220 to inject the push frequency as described above. In addition, the microprocessor advantageously is utilized to adjust the oscillator 216 to determine the frequency of the “push oscillator”. The oscillator 216 may be initially adjusted via a simple variable resistor or variable capacitor. However, it is further adjusted by the microprocessor during operation of the scale. One of these advantages is that the microprocessor can adjust the oscillator 216 to produce the phase shifting described in the previously incorporated applications. In addition, it can be used to produce much larger frequency shifts than were possible in the previously incorporated applications. This results in more accurate determinations of which weight range the scale is in. As described in the previously incorporated applications, the oscillator operated as a periodic function where the same frequencies were repeated over different weight ranges. A phase shift of ±π was used to determine which weight range the scale was operating in. As the weight increased, the same phase shift produced a larger frequency shift (because of the increased length of the delay line) and the frequency shift could be used to determine the weight range. However, under some circumstances, the phase shift resulted in a frequency shift which was too small to accurately determine. The push oscillator of the present invention can be used to produce ±4π phase shifts.
[0053] As mentioned above, the oscillator 216 is preferably initially adjusted with a variable resistor or variable capacitor to ensure oscillation on the mode of best phase linearity. Initial calibration is performed as follows: Known weights are placed on the scale and the frequency of the oscillator output is determined for different weights and the modes of oscillation are noted. The push oscillator is tuned to operate in one mode and experiments are conducted to measure linearity. The experiments are repeated for each mode. The push oscillator is then tuned to push to the mode of best linearity.
[0054] According to another aspect of the invention, a thermistor 224 is coupled via an analog to digital converter 226 to the microprocessor 208 . The thermistor is used to provide long term calibration of the SAW temperature transducer. At first calibration measurements are taken from both the SAW temperature sensor and the thermistor assuming that the true temperature is the thermistor reading. Measurements are taken over a range of 20 or 40° C. and the slope of the SAW temperature sensor output is calculated in HzI° C. This slope is nominally approximately 5,000 Hz/° C. using an oscillator having a 57 MHz central frequency. Periodically, this calibration is repeated to account for the long term instability of the SAW temperature sensor.
[0055] Although one of the earlier applications proposed hermetically sealing sensors, it has been determined that the effects of humidity are accurately accounted for with the SAW temperature sensor. Therefore, it has been determined to be desirable to expose both the displacement transducer and the temperature transducer to the temperature and humidity of the ambient atmosphere.
[0056] As described above and in the previously incorporated related patents, a scale according to the invention will typically use two or more SAW devices. One may be a temperature sensor and the other a weight sensor. Normally, each has its own amplifier to form an oscillator. The temperature sensor is typically be used to compensate for temperature and other changes that occur with the weight sensor. However, the temperature sensor can not compensate for differences caused by differences in the amplifier and other devices in the oscillator.
[0057] Referring now to FIG. 7, it is possible to connect two SAW sensors in parallel to a single amplifier. As shown in FIG. 7, a weight sensor having transducers 300 , 302 is coupled in parallel with a temperature sensor having transducers 304 , 306 to a single amplifier 308 . Each sensor oscillates at a somewhat different center frequency, such as 50 Mhz and 60 Mhz, respectively. A push oscillator 310 controlled by a processor control 312 is arranged to force the oscillator to either 50 Mhz or 60 Mhz. When it forces the oscillator to 50 Mhz, and is then shut off, the first SAW sensor will control the frequency of oscillation output at 314 . When the push oscillator forces a frequency of 60 Mhz and then shuts off, the second SAW sensor will control the frequency of oscillation output at 314 . As the same amplifier is shared by both SAW sensors, errors caused by differences in the amplifiers used by weight and temperature sensors will be automatically compensated for.
[0058] As described above, a push oscillator can be used to force the SAW oscillator to operate in the preferred area of oscillation. However, as the ambient temperature changes, the preferred frequency of oscillation can also change. It would therefore be advantageous to change the frequency of the push oscillator as the temperature changes. One method of doing this is to measure the temperature, either with a SAW temperature sensor or some other temperature sensor and adjust the push oscillator, if the push oscillator is a phase locked loop or some other controllable type.
[0059] Another method, illustrated in FIG. 8, is to use the SAW temperature sensor 406 , 404 , 408 along with a fixed oscillator, such as a crystal oscillator 410 . If the frequencies are properly chosen, and the two outputs are mixed with a mixer 412 , the resultant frequency output at 414 can be used as the push oscillator for the SAW weight sensor. For example, with the SAW temperature sensor center frequency at 54 Mhz, and the SAW weights sensor center frequency at 50 Mhz, the fixed crystal oscillator should have a 4 Mhz frequency. When the temperature oscillator and the crystal oscillator outputs are mixed in a mixer, the output is centered at 50 Mhz, but will vary with temperature.
[0060] As described above and in the previously incorporated patents, in a typical scale the SAW device(s) will be displaced by more than one wavelength. Thus, there will be certain weights which result in identical frequencies of oscillation. A number of methods have been described as to how to determine which “zone” the oscillator is operating in. One method was to use a completely different “coarse” sensor, such as strain gages, or inductive or capacitive sensors. These gives a coarse indication of weight, and therefore determines which “zone” the SAW sensor was operating in.
[0061] According to the present invention two weight sensors are provided, each oscillating at a different frequency. Although both sensors will be displaced by more than one wavelength, they will differ in wavelength. FIG. 9 illustrates the frequency change of two weight sensors operating at different frequencies of oscillation, one shown in a solid line and the other shown in a dashed line. Those skilled in the art will appreciate that at any given weight, the pair of frequency values will be unique.
[0062] As described above and in the previously incorporated patents, a differential pair of SAW weight sensors may be used to improve resolution. When weight increases on the scale platform, one sensor will have an increased distance between the transmitter and receiver, and the other will have a decreased distance. This is best shown in FIGS. 9 - 11 of previously incorporated U.S. Pat. No. 5,910,647. According to the present invention, this arrangement can also be used to locate the zone of oscillation by using different frequencies for each sensor.
[0063] A new method according to the invention is to use different frequencies for each of two or more SAW weight sensors in a differential format. FIG. 10 illustrates the change in frequency of two differential oscillators operating at different frequencies.
[0064] There have been described and illustrated herein several embodiments of an electronic weighing apparatus utilizing surface acoustic waves. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular frequencies have been disclosed, it will be appreciated that other frequencies could be utilized. Moreover, while particular configurations have been disclosed in reference to the location of transmitting and receiving electrodes, it will be appreciated that the respective locations of transmitters and receivers could be reversed. Furthermore, while several different aspects of the invention have been disclosed as solving various problems, it will be understood that the different aspects of the invention may be used alone or in combination with each other in configurations other than those shown. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as so claimed.
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A weighing apparatus which includes a SAW oscillator ( 120 b, 122 b) and a “push oscillator” ( 216, 218, 220 ) to force the SAW oscillator into a desired mode of operation. The device adjusts to temperature by using a temperature sensing SAW transducer assembly ( 124, 126 ). Long term temperature stability of the SAW frequency oscillator is achieved by periodic calibration with a thermistor ( 224 ) signal.
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BACKGROUND OF THE INVENTION
The present invention relates generally to computer systems, and more particularly to power management systems for portable computer systems.
Computerized personal organizers are becoming increasingly popular with a large segment of the population. Computerized personal organizers tend to be small, lightweight, relatively inexpensive, and are able to perform such functions as keeping a calendar, an address book, a to-do list, etc. While many of these functions can also be provided in conventional computer systems, personal organizers are very well suited to the personal organization task due to their small size and portability. Computerized personal organizers are available from such companies as Sharp and Casio of Japan.
A relatively new form of computer, the pen-based computer system, holds forth the promise of a marriage of the power of a general purpose computer with the functionality and small size of a computerized personal organizer. A pen-based computer system is typically a small, hand-held computer where the primary method for inputting data includes a "pen" or stylus. A pen-based computer operating as personal organizer or "Personal Digital Assistant" (PDA) is made by Apple Computer, Inc. of Cupertino, Calif. under the trademark Newton™.
The aforementioned functionality of the PDA often requires a lengthy, elaborate start-up procedure. Start-up procedures for a PDA include both hardware and software initializations. Representative hardware start-up procedures include initializing the display screen, the writing tablet, and the system controller, turning power on to and initializing all other peripheral devices, and initializing all system memory. Representative software start-up procedures include building the memory management unit (MMU) tables in system memory, enabling the MMU on the CPU, and starting the operating system.
In addition to start-up procedure requirements, the PDA has unique shut-down requirements. For a PDA, or any computer system, to start-up efficiently, the system must begin from a known state. The start-up is therefore facilitated by an orderly shut-down. Furthermore, the PDA is typically a battery powered device, leaving it especially susceptible to abnormal shut-down conditions in circumstances such as battery failure or when replacing the battery. Thus it is important that memory management and initialization procedures during start-up and shut-down be more sophisticated than in the case of a desk top computer. This sophistication is perhaps a prerequisite for providing the user of a PDA with the expected level of functionality. For example, the PDA should provide key features of the non-electric organizer such as high data integrity and nearly immediate operation access.
From a simplistic view, an on/off switch of a PDA appears to simply switch the system between two states: power supply on and power supply off. But, as is well know to those skilled in the art of computer system design, the typical on/off switch has no direct effect on the power supply of the computer system. Rather, enabling and disabling the on/off switch respectively generate a power-up interrupt and a power-down interrupt within the system. The system responds to the interrupt with a predefined start-up or shut-down procedure, where start-up places the system in an activated state, and shut-down places the system in a non-activated state. It should be appreciated that the non-activated state does not correspond to a zero power-use state, but rather a low power-use state.
In most personal computer systems, when a user turns the on/off switch on, the system responds by performing what is known as a "cold boot" start-up procedure. The cold boot includes the steps required to initially start-up the computer system. As the functionality of the system grows, the time delay of the cold boot can become very undesirable. It should be appreciated that minimizing this delay is critical in the case of the PDA, as the PDA should be approximately as time economical as the non-computerized organizer.
While all of steps of the cold boot may be performed on start-up, the cold boot may include steps which are unnecessary. For example, initializing the display and the digitizing tablet need only occur once initially on the PDA, and thereafter only if an abnormal event has occurred. If an orderly shut-down occurred previously the start-up could skip many of these steps, thereby reducing the start-up time significantly.
Additionally, many of the software initialization steps, while required even after a previous orderly shut-down, are simply repetitive steps performed on each start-up. Page tables of the Newton PDA, which provide structure to the memory, must be rebuilt on each start-up. Any application software or peripheral devices which utilize volatile memory must completely rebuild in memory-on each start-up. The operating system often utilizes volatile memory which must be loaded on start-up. The MMU of the Newton PDA and the volatile memory is then updated to reflect the data in memory, which applications are running, and the location and status of the peripherals. Any process which eliminates or reduces the time required for these steps enhances the system.
Prior solutions to the time delay took advantage of knowing that a previous orderly shut-down would leave the computer system in a well defined state. This enabled a normal, "quick boot", start-up procedure which eliminated some of the unnecessary cold boot steps. This decreased, and thereby improved, the typical start-up time. However, these solutions created one problem while not solving another: if a previous shut-down was non-orderly, then the user had to manually force a cold boot start-up, either by disconnecting the power source or by engaging a cold boot button. Depending on the shut-down procedure, valuable user data could be lost.
SUMMARY OF THE INVENTION
The present invention teaches a method and apparatus for system recovery from power loss. More specifically, the apparatus includes a computer system having a central processing unit (CPU), a system controller including a protection register coupled to the CPU, and an activation system for controlling the start-up procedure. The value stored in the protection register indicates the manner in which the computer system was previously inactivated, that is, orderly or non-orderly, and the activation means will perform a start-up procedure based on the value of this register.
In accordance with one aspect of the present invention, the computer system further includes non-volatile and volatile memory. During an orderly shut-down, the critical data stored in the volatile memory is stored in the non-volatile memory, along with a corresponding time stamp including date and time, and memory validity data is stored to indicate a successful store occurred. In one embodiment, the protection register is set to 0 indicating an orderly shut-down has occurred. In accordance with one aspect of the present invention, the critical data can be compressed using a run-length encoding method prior to storage in non-volatile memory. In the previous aspect, the memory validity data is a successful store register with the value 1 corresponding to success and the value 0 corresponding to the memory having an unknown status.
The activation system will, preferably, utilize the protection register, the successful store flag, and the time stamp to perform a start-up procedure based on their values. If the protection register has a value of 0 and the successful store register has a value 1, then the protection register is set to 1, all the critical memory restored from non-volatile to volatile memory, and the system is placed in an active state. Setting the protection register to 1 prepares the system for a future start-up in the event of a non orderly shut-down.
In accordance with another aspect of the present invention, if the protection register has a value 0 and the successful store register has a value 0, then all the volatile memory is initialized, new MMU tables are built in the CPU, the protection register is set to 1, any valid user data found in non-volatile memory is restored to volatile memory, and the system is placed in an active state.
If the protection register has a value 1, the CPU is reset. Further, if the successful store register has a value 1 and the time stamp indicates meaningful data is stored in the non-volatile memory, then the protection register is set to 1, all the memory restored, and the system is placed in an active state. If, instead, the successful store has a value 0 or the time stamp indicates that no meaningful data is stored in the non-volatile memory, then all the volatile memory is initialized, new memory management tables are built in the CPU, the protection register is set to 1, any valid user data found in non-volatile memory is restored, and the system is placed in an active state.
The computer system preferably includes a cold boot circuit which provides a cold boot signal to the controller. If the system receives a cold boot signal, it will reset the CPU, initialize all peripheral devices, initialize the system controller, all the volatile memory is initialized, new memory management tables are built in the CPU, the protection register is set to 1, any valid user data found in non-volatile memory is restored, and the system is placed in an active state.
These and other advantages of the present invention will become apparent upon reading the following detailed descriptions and studying the various figures of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer system in accordance with the present invention;
FIG. 2a is a graph illustrating the cold boot circuit input signal as a function of time;
FIG. 2b is a graph illustrating the cold boot circuit output signal as a function of time;
FIG. 3 is a flow diagram of an orderly shut-down procedure of a computer system in accordance with the present invention;
FIG. 4 is a detailed flow diagram of step 64 of FIG. 3;
FIG. 5 is a flow diagram of a start-up procedure of a computer system in accordance with the present invention; and
FIG. 6 is a detailed flow diagram of step 112 of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a computer system 10 in accordance with the present invention includes a central processing unit (CPU) 12, a system controller 14 including a protection register 16, and a communication bus 18. The computer system may also optionally include system memory 20, a main battery 22, a backup battery 24, protection diodes 26, a cold boot reset circuit 28, a display screen 30, and a tablet 32. In the embodiment of FIG. 1, the communication bus 18 comprises a control bus C, a data bus D, and an address bus A. Preferably, the system memory 20 comprises non-volatile read/write memory 34, non-volatile read only memory (ROM) 36, and volatile read/write memory 38.
The CPU 12, non-volatile read/write memory 34, ROM 36, volatile read/write memory 38, and cold boot reset circuit 28 are preferably commercially available integrated circuits ("chips") available from a variety of sources. In one embodiment CPU 12 is a single chip digital processor. ROM 36 contains the basic operation system instructions for the computer system, volatile read/write memory 38 is used for temporary memory, and the non-volatile read/write memory 34 is flash RAM and is used for memory storage during a shut-down state. In another embodiment, the non-volatile read/write memory 34 is simply RAM with its own, separate, battery back-up. In the preferred embodiment, the non-volatile read/write memory 34, the non-volatile ROM 36, and the volatile read/write memory 38, each have a control bus, C1, C2, and C3 respectively, connected directly to the system controller 14.
Preferably, the temporary memory is stored as pages in the volatile read/write memory 38. Temporary memory is under the control of a memory management unit (MMU) 39, which is part of the CPU 12. The non-volatile read/write memory 34 further includes memory validity data in the form of a successful store register, the memory validity data indicative of the validity of the permanent memory stored in the non-volatile read/write memory 34.
The main battery 22 and the backup battery 24 are connected in parallel through the diodes 26 and in series with the cold boot reset switch 42 to the operating power bus 44. The operating power bus 44 is then available to all other system components and peripheral devices.
FIG. 2a is a graph plotting the input signal 45 at the cold boot circuit input 46 as a function of time in response to an actual power interrupt. At a time a time TO power is returned to the operating power bus 44. The delay in reaching Vcc, the operating power voltage level, is due to the RC time constant, i.e. charge time, of a resistor 47 and a capacitor 48 of FIG. 1. Preferably the charge time ΔT is approximately 1 millisecond.
FIG. 2b is a graph plotting the output voltage signal 49 at the cold boot circuit output 50 as a function of time in response to the input voltage signal 45. The cold boot circuit output is tied to a reset input RST of the system controller 14. In one embodiment the power interrupt is forced by an operator pushing the cold boot switch. Additionally the system could include a software forced cold boot. It should be appreciated that removing and replacing all batteries would generate the cold boot signal.
FIG. 3 is a flow diagram for an orderly shut-down process of the computer system 10 in accordance with the present invention. The process of FIG. 3 begins in step 62 with the computer system receiving a power-down interrupt as a result of the user turning the on/off switch to off. The operating system may also initiate a power-down. For example, when the main battery is beginning to fail a power-down initiated by the operating system prevents a disorderly shut-down. In step 64, all critical information is stored in the non-volatile read/write memory 34. Next, in step 66, the MMU is shut-down. In step 68, the protection register 16 is set equal to 0, the value 0 indicating that an orderly shut-down occurred. The process continues in step 70 where all peripheral power is disabled. In step 72, the CPU 12, the system controller 16, and all clocks except a real time clock (RTC) are stopped. Then, in a final step 74, the system is in an inactivated state.
Step 64 of FIG. 3 is illustrated in greater detail in FIG. 4. The process 64 begins with step 80 by sending a message to all tasks running on the computer system 10 to dump all unnecessary pages stored in the permanent pages of the volatile read/write memory 38. That is, erase all data which is not necessary for an efficient start-up. Next, in step 82, a run length encoding compression is performed on the pages remaining in permanent volatile read/write memory 38. Simplifying, run length encoding replaces zeroes in the data with a marker indicating the location and how many zeroes were removed. This is effective since data is frequently stored inefficiently, at least with respect to memory space, often with zeroes padding out unused space. Run length encoding is well known to those skilled in the art of data compression. Next, in a step 84, the encoded contents of permanent volatile read/write memory 38 are stored in the non-volatile read/write memory 34. Once this is completed, a final step 86 sets a successful store register located in non-volatile read/write memory 34 equal to 1 along with a time stamp, indicating the time and date when the successful store occurred.
The power-up process of FIG. 5 begins in step 100 by receiving a power-up interrupt. In step 102, if it is determined that the protection register is 0, the process proceeds on to step 104. Step 104 determines the value of the successful store flag. If the successful store flag is equal to 1, the process continues in step 106 by setting the protection register equal to 1. Setting the protection register equal to 1 indicates that a previous orderly shut-down has not occurred. In step 108, the page tables are restored in the MMU. Next, in step 110, the MMU is enabled. Then in step 112, which is described in further detail in FIG. 6, the memory stored in non-volatile read/write memory 34 is restored into volatile read/write memory 38. Steps 108-112 comprise the "normal boot" procedure. The process continues in step 114 by activating the CPU. Finally, in step 116, the start-up procedure is complete and the computer system is running.
Beginning down the other branch of step 102, if it is determined that the protection register is not 0, the process proceeds to step 120 and performs a hardware reset of the CPU. The process then continues at step 122 by determining the value of the cold boot signal. That is, what is the voltage level at the system controller input RST. If the signal at RST is 0, the process proceeds to initialize the display screen and tablet in a step 124. The process then continues in step 126 by initializing the system controller. Next, in step 128, the volatile read/write memory 38 is initialized, including building the MMU tables. Then in step 130, the process continues by setting the protection register equal to 1. Next, in step 132 the MMU is enabled. In step 134, the process checks the flash RAM 34 to discern if there is recoverable user data. Steps 124-134 comprise the "cold boot" procedure. The process continues in step 114 by activating the CPU. Finally, in step 116, the start-up procedure is complete and the computer system is running.
Continuing down the other branch of step 122, if it is determined that the cold boot signal at RST is 1, then the process proceeds to step 136 and determines the value of the successful store register and whether or not the date is valid. If the successful store register is 0 or if the date is not valid, the process proceeds on to step 128. In step 128, the volatile read/write memory 38 is initialized, including building the MMU tables. Then in step 130, the process continues by setting the protection register equal to 1. Next, in step 132 the MMU is enabled. In step 134, the process checks the flash RAM 34 to discern if there is recoverable user data. Steps 128-134 comprise the "warm boot" procedure. The process continues in step 114 by activating the CPU. Finally, in step 116, the start-up procedure is complete and the computer system is running.
Continuing down the other branch of step 136, if the value of the successful store register is 1 and the date stamp in the non-volatile read/write memory 38 is valid, than the process proceeds to steps 106-116 as previously described.
If in step 104 the successful store flag is 0, then the process executes steps 128-134, 114, and 116 as previous described.
Step 112 of FIG. 5 is illustrated in more detail in FIG. 6. Step 112 begins in step 150 by reloading the volatile read/write memory 38 with the run length encoded contents of non-volatile read/write memory 34. Next, in step 152, the contents of volatile read/write memory 38 are decompressed into their proper form. Then in step 154, the MMU tables are adjusted to reflect all the temporary volatile read/write memory 38 space left unallocated. In a final step 156, control is returned to step 114 of FIG. 5.
It will therefore be apparent from the forgoing discussions that an effective system for recovery from power loss is produced, while minimizing the system start-up delay. This is accomplished by utilizing non-volatile registers which contain information regarding the nature of a previous system shut-down along with system data stored in non-volatile memory during the previous system shut-down.
While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing both the process and apparatus of the present invention. Particularly, it should be understood that the power supply is not limited to a battery supply. For example, it should be appreciated that a direct current power supply powered by a conventional alternating current power source to produce the required voltage is falls within the scope of the present invention.
It should also be appreciated that the protection register need not be located in the system controller. For example, the protection register can be in the non-volatile read/write memory. In the same vein, the successful store register can be located on the system controller. Additionally, the system controller can be designed to include all the necessary non-volatile memory.
It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention.
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A computer system for system recovery from power loss includes a central processing unit and an activation means for starting up the computer. The computer system also has a cold boot circuit, a system controller, volatile read/write memory, and non-volatile read/write memory. The controller includes a protection register whose value indicates the manner in which the computer system was previously shut-down. One aspect of the present invention is a method for an orderly shut-down which includes the steps of compressing all critical data stored in volatile read/write memory, transferring the compressed critical data into non-volatile read/write memory, writing memory validity data to indicate a successful store and the time and date stored, and shutting down the system. Another aspect of the present invention is a method for system recovery which includes the steps of utilizing the protection register and memory validity data to both recover system and user data if possible and perform only the necessary start-up steps, and setting the protection register to indicate that an orderly shut-down has not occurred.
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FIELD OF INVENTION
This invention relates to OFDM systems and, more particularly, to an optimized hardware implementation of the FFT/IFFT module which minimizes the number of clock cycles for computing the FFT/IFFT of a signal.
BACKGROUND OF THE INVENTION
Wireless LAN (WLAN) technology is one of the most widely deployed and most rapidly expanding areas of radio communications. As demand for mobile data grows, networks will have to offer more bandwidth to support both a larger numbers of users as well as higher data transfer rates for individual users. Satisfying these demands involves the deployment of newer air interface technologies such as 3G cellular and the IEEE 802.11a standard.
The IEEE 802.11a standard is based on a multicarrier modulation scheme called orthogonal frequency domain multiplexing (OFDM) in the 5 GHz band. In multicarrier modulation, data signals (bits) are modulated onto a number of carriers rather than on a single carrier as in traditional AM or FM systems. The result is an optimum usage of bandwidth. The basic principle of OFDM is to split a high rate data stream into a number of lower rate streams, which are then transmitted simultaneously over a number of sub-carriers (overlapping, orthogonal narrow band signals). The frequencies used in OFDM are orthogonal. Neighboring frequencies with overlapping spectrum can therefore be used. This results in a more efficient usage of bandwidth. OFDM is therefore able to provide higher data rates for the same bandwidth. It also offers several advantages over single carrier systems such as better multi-path effect immunity, simpler channel equalization and relaxed timing acquisition constraints. Accordingly, OFDM has become the modulation method of choice for many new systems.
Each sub-carrier in OFDM has a fixed phase and amplitude for a certain time duration, during which a small portion of the information is carried. This unit of data is called a symbol and the time period during which the symbol is available is called the symbol duration. After that time period, the modulation is changed and the next symbol carries the next portion of information. A set of orthogonal sub-carriers together forms an OFDM symbol. To avoid inter symbol interference (ISI) due to multi-path propagation, successive OFDM symbols are separated by a guard band. This makes the OFDM system resistant to multi-path effects. Although OFDM has been in existence for a long time, recent developments in DSP and VLSI technologies have made it a feasible option. As a result, OFDM is fast gaining popularity in broadband standards and high-speed wireless LAN standards such as the IEEE 802.11a.
In practice, the most efficient way to generate the sum of a large number of sub-carriers is by using the Inverse Fast Fourier Transform (IFFT). At the receiver side, a fast and efficient implementation of the well known discrete fourier transform (DFT) function called the Fast Fourier Transform (FFT) can be used to demodulate all the sub-carriers. All sub-carriers differ by an integer number of cycles within the FFT integration time, which ensures the orthogonality between different sub-carriers.
Several choices are available for implementing an OFDM modem: digital signal processing (DSP) based implementation, DSP-based implementation with hardware accelerators or a complete ASIC implementation.
High performance digital signal processors (DSPs) are widely available in the market today. The computation intensive and time critical functions that were traditionally implemented in hardware are nowadays being implemented in software running on these processors. However, a DSP-based implementation of an OFDM modem has the disadvantage of not being very optimum in terms of chip area occupied and power consumption.
To overcome limitations incurred with a DSP-based implementation while still retaining the flexibility of a software implementation, some blocks of an OFDM transceiver can be implemented in hardware. Alternatively, the entire functionality may be implemented in hardware. Advantages of this ASIC-based approach include lower gate count and hence, lower cost and lower power consumption.
When general purpose DSP chips do not meet the required performance parameters of an application, an ASIC (application specific integrated circuit) DSP may be developed. When a particular algorithm has to be implemented, for example the FFT/IFFT algorithm, an application specific DSP chip is generated with an architectural structure dependent upon the algorithm's computational structure. Alternatively, the algorithm can be restructured to better fit an available target architecture (for example, that of a parallel computational arrangement). Most current implementations of the FFT/IFFT engine for an OFDM modem are done using a DSP chip with software and concentrate on minimizing calls to the multiplier block.
However, it would be advantageous to implement an FFT/IFFT engine entirely in ASIC technology so that each of the functional blocks of the FFT/IFFT engine be mapped onto dedicated, parallel hardware resources thereby avoiding the difficult programming and optimization challenges of scheduling time-critical operations through a single DSP core. An optimized hardware implementation which minimizes the total run time while at the same time minimizing the number of complex multiplier is, therefore, sought.
SUMMARY OF THE INVENTION
The present invention pertains to symbolic or mathematical manipulation of the FFT/IFFT formula in order to derive an optimal hardware implementation. The invention involves restructuring the FFT/IFFT formula to minimize the number of clock cycles required to compute the FFT/IFFT while at the same time minimizing the number of complex multipliers required.
According to one embodiment of the present invention, a system for performing an N-point FFT/IFFT operation is provided comprising an input module for receiving a plurality of inputs in parallel and for combining said inputs after applying a multiplication factor to each of said inputs, at least one multiplicand generator for providing multiplicands to said system, at least two multiplier modules for performing complex multiplications, at least one of said multiplier modules receiving an output of said input module, each of said multiplier modules receiving multiplicands from said at least one multiplicand generator, at least one of said multiplier modules receiving an output of another multiplier module, a map module for receiving outputs of all of said at least two multiplier modules, said map module selecting and applying a multiplication factor to each of said outputs of said at least two multiplier modules, said map module generating multiple outputs and an accumulation module for receiving and accumulating said multiple outputs of said map module.
In accordance with an aspect of the present invention, an N-point FFT/IFFT operation, with N being the number of input samples, may be performed in N clock cycles using
( N 16 + 1 )
complex multipliers. In accordance with a preferred aspect of the present invention, an N-point FFT/IFFT operation is performed in N clock cycles using
( N 32 + 1 )
complex multipliers. Accordingly, in a preferred implementation of the present invention, an optimized hardware configuration comprising 3 complex multipliers is used to compute a 64-point FFT/IFFT operation in 64 clock cycles. Advantageously, the total number of clock cycles required to complete the FFT/IFFT operation is minimized while at the same time minimizing the number of complex multipliers needed.
The advantage of implementing an FFT/IFFT engine with ASIC technology is that each of the functional blocks of the FFT/IFFT engine be mapped onto dedicated, parallel hardware resources thereby avoiding the difficult programming and optimization challenges of scheduling time-critical operations through a single DSP core.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention will be obtained by considering the detailed description below, with reference to the following drawings in which:
FIG. 1 depicts a brute force hardware implementation for the FFT/IFFT operation;
FIG. 2 depicts a partially optimized hardware implementation for the FFT/IFFT operation;
FIG. 3 depicts a fully optimized hardware implementation for the FFT/IFFT operation according to the present invention;
FIG. 4 depicts an example of the logic flow undertaken by the MAP module of FIG. 3 in accordance with one aspect of the present invention; and
FIG. 5 depicts the general operation of the accumulation module of FIG. 3 in accordance with one aspect of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The basic principle of OFDM is to split a high rate data stream into a number of lower rate streams each of which are transmitted simultaneously over a number of sub-carriers. In the IEEE 802.11a standard OFDM modulation scheme, the binary serial signal is divided into groups (symbols) of one, two, four or six bits, depending on the data rate chosen, and the symbols are converted into complex numbers representing applicable constellation points. Each symbol, having a duration of 4 microseconds, is assigned to a particular sub-carrier. An Inverse Fast Fourier Transform (IFFT) combines the sub-carriers to form a composite time-domain signal for transmission. The IEEE 802.11a standard system uses 52 sub-carriers that are modulated using binary or quadrature phase shift keying (BPSK/QPSK), 16 Quadrature Amplitude Modulation (QAM) or 64 QAM. On the receiver side, the Fast Fourier Transform (FFT) can be used to demodulate all sub-carriers. All sub-carriers differ by an integer number of cycles within the FFT integration time, and this ensures the orthogonality between the different sub-carriers.
The heart of an OFDM baseband processor is, therefore, the FFT/IFFT engine. It is well known that the FFT operation is designed to perform complex multiplications and additions, even though the input data may be real valued. The reason for this situation is that the phase factors are complex and, hence, after the first stage of the operation all variables are complex-valued. Thus, in terms of a hardware implementation, the FFT operation can be implemented using summation modules and multiplication modules (multipliers).
Multiplication modules are the most widely used circuit in an OFDM modem. However, multipliers are costly resources both in terms of chip area and power consumption. A greater number of multipliers will require greater chip area resulting in bulkier devices not suitable for mobile applications. However, the total time it takes for an FFT/IFFT engine to operate on a given set of input samples (i.e. the total run time) is also critical as the less number of clock cycles it takes, the less the power consumption. With regard to the FFT/IFFT engine, it would therefore be desirable to reduce the number of multiplier modules required while at the same time minimizing the number of clock cycles required to compute the FFT/IFFT.
The present invention pertains to symbolic or mathematical manipulation of the FFT formula in order to derive an optimal hardware implementation. The invention involves restructuring the FFT formula to minimize the number of clock cycles required while at the same time minimizing the number of complex multiplier modules. Since both the FFT and IFFT operations involve the same type of computations, only a discussion on the IFFT is presented. Those skilled in the art will appreciate that the formulation presented applies equally to an efficient implementation of the FFT operation.
The computational problem for the IFFT is to compute the sequence Y(n) of N complex-valued numbers given another sequence of data X(k) according to the formula
Y ( n ) = 1 N ∑ k = 0 N - 1 X ( k ) ⅇ j2 kn π N 0 ≤ n ≤ N - 1 equation ( 1 )
In the above formulation, one can see that for each sample n, direct computation of Y(n) involves N complex multiplications (4N real multiplications). Consequently, to compute the IFFT of all N samples, the IFFT requires N 2 complex multiplications.
FIG. 1 depicts one possible hardware implementation of equation (1). In FIG. 1 , N complex-valued numbers defining the input sequence X(k) are fed into a multiplexer (MUX) 120 . The MUX 120 selects one of the N complex-valued inputs and delivers it to a complex multiplier 140 . The complex multiplier 140 is adapted to access to a look-up table (LUT) 150 which contains the values
ⅇ j2 kn π N
for some value N, 0≦k≦N−1 and 0≦n≦N− 1 . The output of the complex multiplier 140 is fed to an accumulation module 180 which may comprise a register 160 . Using a single complex multiplier 140 as in FIG. 1 , it is readily seen that the computation of each output sample requires N complex multiplications and, hence, the use of the complex multiplier 140 N times. In other words, to compute each output time sample, the results of N complex multiplications are added and accumulated in the register. This process will have to repeat itself for each of the N input samples to derive the N output time samples. Since N output samples in total need to be computed, this results in a total runtime of N 2 clock cycles (assuming one complex multiplication per clock cycle) to compute the IFFT for the entire input sequence Y(n).
However, computation of the IFFT using the brute force hardware implementation of FIG. 1 is inefficient primarily because it does not exploit the symmetry and periodicity properties of the phase factor,
ⅇ jθ ,
in equation (1). The present invention exploits these properties to minimize the total run time (number of clock cycles) for computing the IFFT/FFT of a given set of sample data.
Those skilled in the art will appreciate that Equation (1) may be rewritten as the expansion
Y ( n ) = ∑ k = 0 3 X ( N 4 k ) ⅇ j kn π 2 + ∑ k = 0 3 X ( N 4 k + 1 ) ⅇ j ( k 2 + 2 N ) n π + … + ∑ k = 0 3 X ( N 4 k + N 4 - 1 ) ⅇ j ( k 2 + 2 N ( N 4 - 1 ) ) n π equation ( 1 a ) Y ( n ) = ⅇ j2 n π N ( 0 ) ∑ k = 0 3 X ( N 4 k + 0 ) ⅇ j kn π 2 + ⅇ j2 n π N ( 1 ) ∑ k = 0 3 X ( N 4 k + 1 ) ⅇ j kn π 2 + … + ⅇ j2 n π N ( N 4 - 1 ) ∑ k = 0 3 X ( N 4 k + N 4 - 1 ) ⅇ j kn π 2 equation ( 1 b )
or
Simplifying the above yields,
Y ( n ) = ∑ l = 0 N 4 - 1 ⅇ j2lnπ N ∑ k = 0 3 X ( N 4 k + l ) ⅇ j kn π 2 equation ( 2 ) if we let P l ( n ) = ⅇ j2lnπ N equation ( 3 ) and G l ( n ) = ∑ k = 0 3 X ( N 4 k + l ) ⅇ j kn π 2 equation ( 4 )
the set of output samples may be rewritten as
Y ( n ) = ∑ l = 0 N 4 - 1 P l ( n ) G l ( n ) equation ( 5 )
Letting
R l ( n )= P l ( n ) G l ( n ) equation (6)
equation (5) may be rewritten
Y
(
n
)
=
∑
l
=
0
N
4
-
1
R
l
(
n
)
equation
(
7
)
FIG. 2 depicts a hardware implementation for equation (5) above. Incoming complex numbers 216 arrive in groups of four at input ports (K 0 , K 1 , K 2 and K 3 ) of a G l (n) module 220 . Assuming N input samples, the four incoming complex samples of each group will have indices
N 4
apart. For example, the first group of incoming samples would be X( 0 ), X( 0 +N/4), X( 0 +2N/4) and X( 0 +3N/4).
Similarly, the second group of incoming samples would be X( 1 ), X( 1 +N/4), X( 1 +2N/4) and X( 1 +3N/4). The output of the G l (n) module 220 is delivered to a complex multiplier 240 which is adapted to access a look-up table (LUT) 230 containing complex-valued constants P l (n) as defined by equation (3). The output R l (n) of the complex multiplier 240 is the product G l (n) with P l (n) as defined by equation (6). This product is sent to the accumulation module 250 which may comprise a register 260 as shown.
Examining equation (4), it may be shown that the function of the G l (n) module 220 is to simply take the four incoming complex numbers 216 (with indices N/4 apart), multiply each one by a constant
ⅇ j k n π 2
and add them all. It may be shown that the value of the constant
ⅇ j k n π 2
in equation (4) reduces to +1, −1, +j or −j depending on the values of k and sample number n. Therefore, no complex multiplications are conducted in this module.
Considering the implementation in FIG. 2 and keeping equation (5) in mind, those skilled in the art will appreciate that
N 4
complex multiplications of P l (n)×G l (n) are required for the computation of each output sample. The results of these multiplications may then be added together in the accumulation module 250 to obtain each output sample. Therefore, a single output is generated every
N 4
clock cycles. Since N outputs need to be computed, the total run time required to compute the FFT/IFFT for a set of N input samples using the implementation in FIG. 2 with one complex multiplier has been reduced from N 2 clock cycles to
N 2 4
clock cycles. Although the reduction in total run time from N 2 clock cycles in FIG. 1 to
N 2 4
clock cycles in FIG. 2 is an improvement, further optimization may be made by exploiting the periodicity of the phase factor, e jθ , in functions P l (n) and G l (n).
For example, substituting (n+4) for n in equation (4) for G l (n) yields,
G l ( n + 4 ) = ∑ k = 0 3 X ( N 4 k + l ) ⅇ j k ( n + 4 ) π 2 = ⅇ j k 2 π ∑ k = 0 3 ( N 4 k + l ) ⅇ j kn π 2 equation ( 8 )
or
G l ( n+ 4)= e jk2π G l ( n )= G l ( n ) equation (9)
Similarly, substituting (n+4) for n in equation (3) for P l (n) yields,
P l ( n + 4 ) = ⅇ j 2 l ( n + 4 ) π N = ⅇ j 2 l n π + j 8 l π N = ⅇ j 2 l n π N · ⅇ j 8 l π N equation ( 10 ) or P l ( n + 4 ) = ⅇ j 8 l π N P l ( n ) equation ( 11 )
Substituting equation (11) and equation (9) into equation (6), it may be shown that
R
l
(
n
+
4
)
=
P
l
(
n
+
4
)
G
l
(
n
+
4
)
=
ⅇ
j
8
l
π
N
P
l
(
n
)
G
l
(
n
)
=
ⅇ
j
8
l
π
N
R
l
(
n
)
equation
(
12
)
The relationship defined by equation (12) states that, for a given value of l, the function R l (n) for any given output sample is a phase rotation of the computed functions' value four output samples before. Previously, each output sample required
N 4
computations of R l (n) which were then summed to arrive at a given output sample. With R l (n) displaying the recursive relationship defined by equation (12), each output sample still requires
N 4
computations of R l (n). However, once the first four output samples i.e. Y( 0 ), Y( 1 ), Y( 2 ), ( 3 ) are computed in N clock cycles (i.e. N computations), the values of R l (n) required to compute all other output samples are simply phase rotations of the previously calculated R l (n) values. In other words, the number of clock cycles required for the entire FFT/IFFT operation is reduced to N.
In terms of simplifying a hardware implementation, a variable β can be defined with β being a multiple of 4. Then, the following relation can be shown to hold
R l ( n + β ) = ⅇ j 2 β l π N R l ( n ) equation ( 13 )
Accordingly, equation (7) may be rewritten as
Y
(
n
+
β
)
=
1
N
∑
l
=
0
N
4
-
1
R
l
(
n
+
β
)
=
1
N
∑
l
=
0
N
4
-
1
P
l
(
n
+
β
)
G
l
(
n
+
β
)
or
equation
(
14
)
Y
(
n
+
β
)
=
1
N
∑
l
=
0
N
4
-
1
R
l
(
n
)
ⅇ
j
2
β
l
π
N
equation
(
15
)
Those skilled in the art will appreciate that only the first
N 16
products in equation (15) require complex multiplications to be performed. For all other values of l, the product in equation (15) can be found by a trivial multiplication of one of the first
N 16
products. Accordingly,
( N 16 + 1 )
complex multipliers are now required to perform the FFT/IFFT operation in N clock cycles. Although the number of clock cycles to perform the FFT/IFFT operation has been reduced by an order of magnitude from N 2 to N, this has been at the expense of adding
N 16
more complex multipliers. However, the number of complex multipliers required may be further reduced using a very useful property as described below.
In the general case, let us define a first complex number A=x+jy with real part x and imaginary part y and a second complex number B=y+jx where B is the reflection of A about the 45 degree line in the unit circle. For complex numbers A and B each multiplied by a third complex number Z=R+jM, the following products are obtained:
A×Z =( xR−My )+ j ( Ry+Mx ) equation (16)
B×Z =( Ry−Mx )+ j ( My+Rx ) equation (17)
Examining equations (16) and (17) it is observed that all inner products (real multiplications) for both complex multiplications may be obtained by only carrying out one of the original complex multiplications. In other words, by computing A×Z, no new multiplications are required to compute B×Z. Computing B×Z is simply a matter of rearranging the way the different inner products from A×Z are added or subtracted. This useful property, called Image Multiplication (since B is a mirror image of A about the 45-degree line in the unit circle), may be exploited to halve the number of complex multipliers determined previously.
Specifically, to compute all possible products
R l ( n ) · ⅇ j 2 β l π N
in equation (15), only
N 32
multipliers are required. Since one additional multiplier is required to compute R l (n) itself, the total number of complex multipliers required is
( N 32 + 1 ) .
Therefore, in accordance with an aspect of the present invention, the total number of clock cycles required for computing an N-point FFT/IFFT can reduced by an order of magnitude from N 2 to N by using only
( N 32 + 1 )
complex multipliers.
According to an embodiment of the present invention, it is assumed that a 64-point FFT/IFFT operation is required i.e. N=64. In this case, equation (15) reduces to
Y ( n + β ) = 1 64 ∑ l = 0 15 R l ( n ) ⅇ j β l π 32 equation ( 18 )
where β is a multiple of 4 and 0<β≦60. Examining equation (18) above and noting that β is a multiple of 4, it is clear that in order to compute the IFFT/FFT, the multiplication of R l (n) with only three complex numbers
ⅇ j 4 π 32 , ⅇ j8 π 32 and ⅇ j 12 π 32
is required. All other multiplications simply entail multiplying one of these products by 1, −1, j or −j.
FIG. 3 depicts an optimized hardware implementation 300 of the 64-point IFFT/FFT operation defined by equation (18) in accordance with one aspect of the present invention. A first G module 310 having four input ports K 0 , K 1 , K 2 , and K 3 receives four complex-valued input samples and is adapted to access a first look up table (LUT) 316 . An output G l (n) of the G module 310 is delivered to a first complex multiplier module GX 320 which is adapted to access a second look-up table (LUT) 326 . The output R l (n) of the first complex multiplier module GX 320 is delivered to a MAP module 360 . An output R l (n) of the first complex multiplier module GX 320 is further routed to a second complex multiplier module GX 1 330 and to a third complex multiplier module GX 2 340 . The second multiplier module GX 1 330 is adapted to access a first storage unit 336 containing a predefined complex-valued constant and delivers its output to the MAP module 360 . Similarly, the third multiplier module GX 2 340 is adapted to access a second storage unit 346 containing a predefined complex-valued constant and delivers two outputs to the MAP module 360 . The MAP module 360 generates a set of sixteen outputs 370 which are subsequently delivered to an accumulation module 380 . The accumulation module 380 generates a set of sixteen outputs 390 corresponding to sixteen output time/frequency samples. In the implementation of FIG. 3 , therefore, sixteen output samples are generated at any given time from sixty-four input samples.
The G module 310 is the first module to receive incoming complex numbers. As in FIG. 2 , the G module 310 has four input ports (K 0 , K 1 , K 2 and K 3 ) and simply takes four incoming complex-valued samples 302 with indices being sixteen (N/4) apart, multiplies each one by a constant (+j, −j, +1 or −1) and adds them to form the output G l (n).
Specifically, four new complex numbers get latched into this module during each clock cycle. In order to load all 64 input samples for a 64-point IFFT/FFT computation, sixteen clock cycles are required. Since sixteen output samples 390 are generated at the output of the entire IFFT/FFT block, the entire process is repeated 4 times to result in output time samples. A counter state n can thus be defined where n=0, 1, 2, 3 corresponding to the computation of each set of sixteen output samples.
Once four complex numbers are loaded, the G module 310 accesses the look up table (LUT) 316 to obtain appropriate multiplication factors for each complex number. The multiplication factor for each complex number may take on one of four possible values: +1, −1, +j or −j. For each complex number, the multiplication is performed on both real and imaginary parts. The results are then added to generate the output G l (n) which is pushed to the output port. This process must be repeated sixteen times (l ranging from 0 to 15) in order to generate the sixteen G l (n) values necessary for each output sample.
In one implementation, the look-up table (LUT) 316 accessed by the G module 310 can have sixteen entrees. Two stimulus variables, namely the port number (0, 1, 2 or 3) and counter state n may then be used to define the value of the multiplication factor. A single local controller (not shown) may be used to select one set of multiplication factors from the LUT 316 and subsequently push them to the G module 310 . Since the multiplication factors selected from the LUT 316 are determined by the two stimulus variables, the LUT 316 may take the form of a truth table.
The output G l (n) of the G module 310 is delivered to the GX Module 320 . The GX module 320 is a complex multiplier used to generate R l (n) from G l (n). The output of this module may be described by the complex product
[ cos ( l n π 32 ) + j sin ( l n π 32 ) ] × output from G module
where two global input variables are defined as before with n ranging from 0 to 3 and l ranging from 0 to 15. The GX module 320 performs a complex number multiplication of its received input G l (n) by a complex-valued constant,
P l ( n ) = ⅇ jlnπ 32 ,
where values for P l (n) are stored in the corresponding look-up table (LUT) 326 .
In a specific implementation, the LUT 326 may comprise eight predefined values i.e.
ⅇ j π 32 , ⅇ j2 π 32 … ⅇ j 8 π 32
hard coded into the LUT block. Generating these eight constants is sufficient since all other constants can be easily derived based on these constants and the application of an appropriate multiplication factor. Based on the value of the product l×n, one of the eight values is selected. The next step is to determine the multiplication factor which can be one of four possible numbers: +1, −1, +j, or −j. In this manner, any constant
P l ( n ) = ⅇ j l n π 32
may be derived by performing a simple multiplication of a selected one of the eight values in the LUT 326 by an appropriate multiplication factor. The output R l (n) of the GX module 320 is subsequently delivered to the MAP module 360 . The output R l (n) is also routed to the GX1 module 330 and to the GX2 module 340 .
The GX1 module 330 is a complex multiplier used to perform the complex multiplication of its received input R l (n) by a fixed complex-valued constant,
ⅇ j 8 π 32 .
Mathematically, the output of the GX1 module 330 may be described by the following product:
[ cos ( 8 π 32 ) + j sin ( 8 π 32 ) ] × output from GX module
The GX1 module is adapted to access the storage unit 336 to obtain the complex-valued constant,
ⅇ j 8 π 32 .
The output of the GX1 module 330 is delivered to the MAP module 360 .
The GX2 module 340 is also a complex multiplier used to perform the complex multiplication of its received input R l (n) by two fixed complex valued constants,
ⅇ j4 π 32
and
ⅇ j 12 π 32 .
Mathematically, the function of this module may be described by the following products:
[ cos ( 4 π 32 ) + j sin ( 4 π 32 ) ] × output from GX module [ cos ( 12 π 32 ) + j sin ( 12 π 32 ) ] × output from GX module
The GX2 module 340 receives the output R l (n) of the GX module 320 and is also adapted to receive the fixed constant
ⅇ j4 π 32
from the corresponding storage unit 346 .
Those skilled in the art will appreciate that
ⅇ j4 π 32
is the same as
ⅇ j12 π 32
with the real and imaginary components reversed. Therefore, by multiplying R l (n) with
ⅇ j4 π 32 ,
the product of R l (n) by
ⅇ j12 π 32
may be obtained by manipulating the result of the first product thereby eliminating the need to perform an extra multiplication. Specifically, the second product
R l ( n ) × ⅇ j12 π 32
may be obtained simply by rearranging the manner in which the inner products resulting from the first product i.e.
R l ( n ) × ⅇ j4 π 32
are added or subtracted. The results of these two products are then delivered to the MAP module 360 . Once the products of the three complex multiplications performed by the GX module 320 , the GX1 module 330 and the GX2 module 340 are generated, they are sent to the MAP module 360 where the product of of
R l ( n ) by ⅇ jβ l π 32
for any value of β (multiple of 4) and l (integer) can be predicted.
The mathematical function performed by the MAP module 360 is to compute the sixteen component values,
R l ( n ) · ⅇ j l β π 32
with l ranging from 0 to 15, for each required output time sample. The MAP module 360 in FIG. 3 is adapted to receive four inputs corresponding to the complex products computed by the complex multiplier modules 320 , 330 and 340 . In the embodiment of FIG. 3 , the MAP module 360 has sixteen outputs corresponding to sixteen distinct output samples.
Each input port of the MAP module 360 receives a unique complex number, R l (n), multiplied by a certain constant
( l , ⅇ j4 π 32 , ⅇ j8 π 32 or ⅇ j12 π 32 ) .
For each value of l with l ranging from 0 to 15, sixteen component products defined by
R l ( n ) · ⅇ jβ `l π 32
and corresponding to different output time samples (granularity of 4) need to be computed and delivered to the output ports. However, out of the sixteen component products which need computing, four have already been computed. These are simply the four complex-valued inputs to the MAP module 360 . From these four inputs, any of the required sixteen component products may be generated by a simple multiplication of one of the four inputs by +1, −1, +j or −j. FIG. 4 depicts an example of the logic flow 400 which may be undertaken in the MAP module 360 to arrive at one of sixteen component products. As shown, a MUX stage 420 receives the 4 inputs from modules GX, GX 1 and GX 2 . Depending on the output port (β) of the MAP module 360 being considered and the value of l, a complex product from one of the four input ports is selected and forwarded to a Decision stage 440 where an appropriate multiplication factor is applied. This process is implemented for each output port of the MAP module 360 . The sixteen outputs 370 of the MAP module are subsequently delivered to the accumulation module 380 whose functionality is described below.
The accumulation module 380 receives sixteen inputs from the MAP module 360 . For each given input port, sixteen incoming complex numbers (these are the component values corresponding to values of equation (18) for l ranging from 0 to 15) arrive every clock cycle to be summed together in a register in order to generate one single output sample. This process occurs for each of sixteen input ports resulting in sixteen output time samples being computed in parallel. After the sixteen component values are summed for each input, the registers are cleared and the process is repeated for computation of the next set of sixteen output time samples. A general depiction of the operation performed by the accumulation module 380 is shown in FIG. 5 .
According to the embodiment in FIG. 3 , using three (3) complex multipliers allows for the generation of 16 output samples every 16 clock cycles. Therefore, the total run time for applying the IFFT/FFT operation on the 64 complex-valued input samples would be 64 clock cycles. With regard to the brute force implementation depicted in FIG. 1 , at the expense of adding two complex multipliers, the total number of clock cycles required to compute the 64-point FFT/IFFT has been reduced by an order of magnitude from (64) 2 to 64.
Due to the similarity between the forward and inverse FFT (the IFFT differs from the FFT only by the sign of the exponent), the same module or circuitry with trivial modifications can be used for both modulation and demodulation in an OFDM transceiver. Although not shown, it should also be noted that depending on if the FFT or IFFT is to be computed, the accumulation module 380 treats its addition results differently. If the IFFT operation is required, the final result of the addition for each output sample is divided by the total number of samples (i.e. N). In the embodiment of FIG. 3 and assuming the IFFT operation is desired, for example, the results of each accumulation would be divided by 64. If the FFT operation is desired, there is no division.
The advantage of an FFT/IFFT engine implemented with ASIC technology is that each of the functional blocks of the FFT/IFFT engine be mapped onto dedicated, parallel hardware resources thereby avoiding the difficult programming and optimization challenges of scheduling time-critical operations through a single DSP core.
It should be noted that the LUTs and other modules which provide multiplicands to the complex multiplier modules can be termed as multiplicand generators as they provide multiplicands for the system.
While preferred embodiments of the invention have been described and illustrated, it will be apparent to one skilled in the art that numerous modifications, variations and adaptations may be made without departing from the scope of the invention as defined in the claims appended hereto.
Although various exemplary embodiments of the invention have been disclosed, it should be apparent to those skilled in the art that various changes and modifications can be made which will achieve some of the advantages of the invention without departing from the true scope of the invention.
A person understanding this invention may now conceive of alternative structures and embodiments or variations of the above all of which are intended to fall within the scope of the invention as defined in the claims that follow.
|
The present invention discloses an optimal hardware implementation of the FFT/IFFT operation that minimizes the number of clock cycles required to compute the FFT/IFFT while at the same time minimizing the number of complex multipliers needed. For performing an N-point FFT/IFFT operation in N clock cycles, the optimal hardware implementation consists of several modules. An input module receives a plurality of inputs in parallel and combines the inputs after applying a multiplication factor to each of the inputs. At least one multiplicand generator is used to provide multiplicands to the system. At least two complex multiplier modules for performing complex multiplications are required with at least one of the complex multiplier modules receiving an output from the input module. Each of the complex multiplier modules receives multiplicands from the at least one multiplicand generator. Furthermore, at least one of the complex multiplier modules receives an output of another complex multiplier module. A map module is provided for receiving outputs of the at least two complex multiplier modules, the map module selecting and applying a multiplication factor to each of the outputs received to generate multiple outputs. Finally, an accumulation module receives and performs an accumulation task on each of the multiple outputs of the map module thereby generating a corresponding number of multiple outputs. In a preferred embodiment, the N-point FFT/IFFT operation is performed in N clock cycles using
( N 32 + 1 )
complex multipliers. In a specific implementation, a system comprising 3 complex multipliers is used to compute a 64-point FFT/IFFT operation in 64 clock cycles. Advantageously, the total number of clock cycles required to complete the FFT/IFFT operation is minimized while at the same time minimizing the number of complex multipliers needed.
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BACKGROUND
[0001] 1. Field of the Invention
[0002] Embodiments of the present invention relate to a method of imparting beneficial features to a flocked surface. More particularly, embodiments of the present invention relates to a method of delivering long lasting release of benefit agents to flocked surfaces, using polymeric microcapsules.
[0003] 2. Description of Related Art
[0004] Polymer microcapsules are used to deliver fragrance and other actives in wash-off consumer products such as fabric softeners. Polymer microcapsules have also been used in printing applications on paper, to provide scent or release ink (e.g., carbonless paper). Flocked surfaces have fibers attached to a surface (typically with adhesive) to provide a tactile sensation such as a soft velvet feel or to increase friction to add grip to items. Flocked articles are increasingly used for various purposes, for example, to give an article a velour texture such articles as clothes hangers, t-shirts, wallpaper, gift, jewelry boxes, or upholstery. It would be difficult to print on flocked surfaces, and these surfaces cannot be washed.
[0005] Microcapsules are understood to be spherical aggregates with a diameter of about 0.001 mm to about 0.5 mm, and contain at least one solid or liquid core surrounded by at least one polymeric shell. The membrane may consist of natural, semi-synthetic or synthetic materials. The application of micro-encapsulation techniques has offered possibility of producing novel products with many beneficial features and improvements. The microcapsules can introduce important new qualities to garments and fabrics, such as fabrics with durable fragrances, odor elimination, insect repellant and insecticide, care for fabric, skin or hair (e.g., aloe), UV-ray absorbing microcapsules, thermo-changeable dyes, thermo-regulation phase change ingredients, and antimicrobials.
[0006] It is desirable to deliver fragrance benefits on flocked surfaces, to deliver these benefits in a closet, drawer or hanger where they are used. Clothes, especially jackets or coats kept in a closet, drawer or hanger, are frequently contaminated by different kinds of odors, such as smoke, sweat, drink, food or dirt. Clothes also get colonized by fungus, bacteria and infested with insects (e.g., moths). This is undesired and therefore, there is a need of method to prevent such contaminations. Use of polymeric microcapsules containing a perfume and other agents offer a probable solution, but there are problems associated therewith.
[0007] Thus, there is a need for a method for the application of a beneficial agent comprising microcapsules, on to a hard flocked surface that leads to relatively long lasting beneficial effects.
SUMMARY
[0008] Embodiments in accordance with the present invention provide a method of imparting beneficial features to a hard flocked surface using polymeric microcapsules containing a desired beneficial agent in its core. The beneficial features imparted to the hard flocked surface comprise relatively long lasting fragrance or protection from bad odor, insects, pests, fungi, bacteria and viruses.
[0009] Embodiments in accordance with the present invention further provide polymeric microcapsules encapsulating a desired beneficial agent as a core material in a polymeric microcapsule.
[0010] Embodiments in accordance with the present invention further provide a clothes hanger, a closet or a drawer, which releases fragrance for a relatively longer time and protects a stored article from odor, insect, pest, fungi, bacteria, virus, and the like.
[0011] Embodiments in accordance with the present invention further provide a slurry mixture used for transferring microcapsules having a polymeric capsule containing a beneficial agent. Other embodiments include a wetting agent and a chemical scavenger.
[0012] Embodiments in accordance with the present invention further relate to hard flocked products including clothes hanger, closet, drawers, and/or treatment compositions comprising such microcapsules, and processes of making and using same.
[0013] Further, embodiments of the present invention can provide a number of advantages depending on its particular configuration. Embodiments of the present invention provide a method of transferring polymeric microcapsule on to a hard flocked surface, which is able to stably retain a beneficial agent for an extended period. The method is particularly suitable for imparting fragrance to a clothes hanger and the like. In addition, products having hard flocked surfaces, including closets and drawers can be enhanced using the aforementioned process. Next, the method further ensures uniform distribution of the microcapsules to avoid aesthetic defects and to provide long lasting benefits to the treated products.
[0014] These and other advantages will be apparent from the disclosure of embodiments of the present invention contained herein.
[0015] The preceding is a simplified summary of the present invention to provide an understanding of some aspects of the present invention. This summary is neither an extensive nor exhaustive overview of the present invention and its various embodiments. It is intended neither to identify key or critical elements of the present invention nor to delineate the scope of the present invention but to present selected concepts of the present invention in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the present invention are possible, utilizing alone or in combination, one or more of the features set forth above or described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed description of embodiments thereof, especially when taken in conjunction with the accompanying drawing, and wherein:
[0017] FIG. 1A is a flocked cloth hanger which was not properly coated and is showing white specs;
[0018] FIG. 1B is a flocked cloth hanger which is properly coated and is showing no white specs in accordance with an embodiment of the present invention;
[0019] FIG. 2A is a schematic diagram of a method of dipping to transfer polymeric microcapsule to hard flocked surfaces in accordance with an embodiment of the present invention;
[0020] FIG. 2B is a schematic diagram of a method of spraying to transfer polymeric microcapsule to hard flocked surfaces in accordance with an embodiment of the present invention; and
[0021] FIG. 2C is a schematic diagram of a method of padding to transfer polymeric microcapsule to hard flocked surfaces in accordance with an embodiment of the present invention.
[0022] The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including but not limited to. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures.
DETAILED DESCRIPTION
[0023] The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
[0024] The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted the terms “comprising”, “including”, and “having” can be used interchangeably.
[0025] The present invention is described in detail in the following section with the aid of embodiments and the figure, which are intended to illustrate the present invention. An embodiment of the present invention provides a method of imparting beneficial features to a hard flocked surface of an article. The method includes encapsulating a desired beneficial agent as a core material in a polymeric microcapsule, and transferring polymeric microcapsule to the surface by dip, spray or padding application.
[0026] Density of microcapsules is typically lower than water and can aggregate at the surface of diluted suspensions. Such aggregates may result in rapid phase separation of the microcapsule from the bulk phase and consequently during spraying or dipping operations. This can create uneven application and yield unacceptable aesthetics. Such aggregates can be prevented by providing constant, high agitation during the application process. Further, the addition of aggregate inhibiting materials and/or suspension stabilizers may be employed.
[0027] Substances that can be used as suspension stabilizers include natural polysaccharides such as xanthan gum, semi-synthetic polysaccharides such as carboxymethylcellulose and hydroxypropylcellulose, synthetic polymers such as sodium polyacrylate, and microfine mineral powders such as magnesium aluminum silicate and high-purity bentonite. These substances can be used singly or as an admixture of two or more of said substances. These substances stabilize the capsule slurry by increasing its viscosity.
[0028] Flocked surfaces can be hydrophobic and may resist wetting during spraying, dipping or padding. To overcome this and assure uniform and complete application, high agitation is employed. In addition, the use of a wetting agent may be employed, to increase penetration rate. Wetting agents can be anionic or nonionic surfactants. Nonionic surfactants such as Tween 20 are preferred, due to their low foaming properties.
[0029] Substances that can be used as wetting agents are nonionic surfactants such as sorbitan monoester (tween 20), alcohol ethoxylates and alkyphenolethoxylates and alkyl polyglucosides. In addition, anionic surface active agents such as lignin sulfonate, condensation product of sodium naphthalene sulfonate and formaldehyde, polyoxyethylenealkylaryl sulfates, polyoxyethylenestyrylphenyl ether sulfate and polyoxyethylenenonyl ether sulfate. Nonionic and Anionic wetting agents can be used singly or as a mixture of these substances.
[0030] Suitable equipment for use in the processes disclosed herein may include a continuous high shear mixer, stirred tank reactors, homogenizers, turbine agitators, re-circulating pumps, paddle mixers, plough shear mixers, ribbon blenders, vertical axis granulators and drum mixers, both in batch and, where available, in continuous process configurations, spray dryers, and extruders.
[0031] Wall materials are typically encapsulating polymers that are formed around the benefit agent, providing a protective shell that protects the benefit agent, until it is released. Release is typically achieved with frictional shear force on the microcapsules, during use or handling of items which have been treated with microcapsules. Useful wall materials include materials selected from the group consisting of polyethylenes, polyamides, polystyrenes, polyisoprenes, polycarbonates, polyesters, polyacrylates, polyureas, polyurethanes, polyolefins, polysaccharides, epoxy resins, vinyl polymers, and mixtures thereof.
[0032] In an embodiment of the present invention, useful wall materials include materials that are sufficiently impervious to the core material and the materials in the environment in which the benefit agent containing delivery particle will be employed, to permit the delivery benefit to be obtained. Suitable impervious wall materials include materials selected from the group consisting of: reaction products of one or more amines with one or more aldehydes, such as urea cross-linked with formaldehyde or gluteraldehyde, melamine cross-linked with formaldehyde; gelatin-polyphosphate coacervates optionally cross-linked with gluteraldehyde; gelatin-gum Arabic coacervates; cross-linked silicone fluids; and polyamine reacted with polyisocyanates and mixtures thereof. In an embodiment, the wall material comprises melamine cross-linked with formaldehyde.
[0033] Encapsulating polymers include polymers formed from melamine-formaldehyde or urea-formaldehyde condensates, as well as similar types of aminoplasts. Additionally, capsules made via the simple or complex coacervation of gelatin are also used with the coating.
[0034] Useful core materials include perfumes, silicone oils, waxes, hydrocarbons, higher fatty acids, essential oils, lipids, skin coolants, antioxidants, glycerine, malodor reducing agents, odor-controlling materials, antistatic agents, softening agents, insect and moth repelling agents, antioxidants, sanitization agents, disinfecting agents, germ control agents, mold control agents, mildew control agents, antiviral agents, fabric refreshing agents and freshness extending agents, chlorine bleach odor control agents, and natural actives such as aloe vera, vitamin E, shea butter, cocoa butter, and the like, antibacterial actives, cationic polymers, and mixtures thereof. Useful core materials are not limited to above materials, and are listed for example purpose only.
[0035] According to an embodiment of the present invention, the perfume comprises Fresh Floral SB, Musk GL, Cedar, Marine Ozone, Fruity TA, Lav.Fresh 101 at a concentration of about 10 to 15 g/l.
[0036] Delivery of benefit agents can be achieved on flocked surfaces, with microcapsules that are friable when in the dry state. The level of benefit can be adjusted by adjusting the level of application. Further, the duration can be adjusted by adjusting the level of the application.
Example 1
[0037] In one example, a microcapsule containing a fresh floral scent was applied, typical in fabric softeners, at 2 concentrations (10 g/1 and 20 g/l). The table 1 below shows sensory results over time. The scale ranges from 0-10 where ‘0’ is no odor detected, ‘5’ is moderate odor signal and 10 is extremely strong odor signal. Scores above ‘3’ are considered easily recognized by consumers. Hangers were rubbed twice then evaluated for odor strength.
[0000]
TABLE 1
Sensory Results Over Time
Application
Fragrance Type
Level
Initial
Month 6
Month 12
Fresh Floral SB
20 g/l
8.5
8.5
8.0
Fresh Floral SB
10 g/l
7.5
7.0
6.5
Example 2
[0038] In another example, the applicant discovered a wide range of scented microcapsules provide an enduring benefit over a long period of time.
[0000]
TABLE 2
Scented Microcapsules Sensory Results Over Time
Fragrance Type
Application Level
Initial
Month 6
Month 12
Fresh Floral SB
10 g/l
7.5
7.0
6.5
Musk GL
15 g/l
7.0
7.0
7.0
Cedar
10 g/l
8.0
7.5
7.5
Marine Ozone
10 g/l
7.5
7.5
7.5
Fruity TA
10 g/l
7.0
6.5
6.0
Lav. Fresh 101
10 g/l
8.0
7.5
N/A
[0039] Particle composition, where the total weight of the slurry totals 100%: water is typically about 60% with about 40% solids. The particle solids range from about 2 to 20% wall material (typically about 5 to 10%) with and Inner Phase that is about 80 to 98% of the particle (typically about 90 to 95%). The Inner phase may typically contain about 0 to 30% stabilizer (such as Mineral Oil or Neobee M5), that balance being benefit agent.
[0000]
TABLE 3
Range
Range
Typical
Water
65
55
60
Particle
35
45
40
Wall (% particle)
2
20
5
Inner Phase Stabilizer (% particle)
0
30
20
Benefit Agent (% particle)
98
50
75
[0040] Benefit agents can be fragrance ingredients that provide freshness, a signature scent or signal other benefits like hygiene, comfort, etc. The fragrance ingredients can optionally be selected from the EPA 25b list of GRAS pesticides to provide additional benefits and claims. Many of these ingredients, such as cedar oil, would be desirable in a closet with flocked hangers. In addition, the benefit agent could include materials that react with certain malodor compounds to render them odorless. Finally, benefit agents could be other pesticides to kill unwanted insects (moths, lice, fleas or bedbugs), provide hygiene benefits, or prevent mold.
[0041] The encapsulating polymers could include materials selected from the group consisting of: polyethylenes, polyamides, polystyrenes, polyisoprenes, polycarbonates, polyesters, polyacrylates, polyureas, polyurethanes, polyolefins, polysaccharides, epoxy resins, vinyl polymers, and mixtures thereof. In one embodiment, useful wall materials include materials that are sufficiently impervious to the core material and the materials in the environment in which the benefit agent containing delivery particle will be employed, to permit the delivery benefit to be obtained.
[0042] Suitable impervious wall materials include materials selected from the group consisting of: reaction products of one or more amines with one or more aldehydes, such as urea cross-linked with formaldehyde or gluteraldehyde, melamine cross-linked with formaldehyde; gelatin-polyphosphate coacervates optionally cross-linked with gluteraldehyde; gelatin-gum Arabic coacervates; cross-linked silicone fluids; polyamine reacted with polyisocyanates and mixtures thereof. In one embodiment, the wall material comprises melamine cross-linked with formaldehyde.
[0043] It is important to maintain high level of agitation during the application process, in order to maintain uniform and complete application, and avoid aesthetic defects.
[0044] Microcapsules can be applied in a number of ways in accordance with embodiments of the present invention. For example, they could be sprayed onto the flocked surface, and then dried. On irregular surfaces, such as clothes hangers, care must be taken to assure complete and even application, which will likely result in over-spray. Over-spray can be collected, optionally filtered (to remove flocking fibers, and reused/re-sprayed onto subsequent hangers.
[0045] Formaldehyde Scavenging
[0046] After certain types of formaldehyde containing microcapsule wall film is formed, the free formaldehyde remaining in the solution can be reduced or removed by the addition of urea, ethylene urea, sulfites, sugars, ammonia, amines, acrylamide, acrylamide copolymers, or other chemicals which will react with formaldehyde under suitable conditions to convert the residual formaldehyde into a harmless substance.
[0047] In an embodiment of the present invention, polymeric microcapsules may be combined with a formaldehyde scavenger. Suitable formaldehyde scavengers include materials selected from the group consisting of sodium bisulfite, urea, ethylene urea, cysteine, cysteamine, lysine, glycine, serine, carnosine, histidine, glutathione, 3,4-diaminobenzoic acid, allantoin, glycouril, anthranilic acid, methyl anthranilate, methyl 4-aminobenzoate, ethyl acetoacetate, acetoacetamide, malonamide, ascorbic acid, 1,3-dihydroxyacetone dimer, biuret, oxamide, benzoguanamine, pyroglutamic acid, pyrogallol, methyl gallate, ethyl gallate, propyl gallate, triethanol amine, succinamide, thiabendazole, benzotriazol, triazole, indoline, sulfanilic acid, oxamide, sorbitol, glucose, cellulose, poly(vinyl alcohol), partially hydrolyzed poly(vinylformamide), poly(vinyl amine), poly(ethylene imine), poly(oxyalkyleneamine), poly(vinyl alcohol)-co-poly(vinyl amine), poly(4-aminostyrene), poly(l-lysine), chitosan, hexane diol, ethylenediamine-N,N′-bisacetoacetamide, N-(2-ethylhexyl)acetoacetamide, 2-benzoylacetoacetamide, N-(3-phenylpropyl)acetoacetamide, lilial, helional, melonal, triplal, 5,5-dimethyl-1,3-cyclohexanedione, 2,4-dimethyl-3-cyclohexenecarboxaldehyde, 2,2-dimethyl-1,3-dioxan-4,6-dione, 2-pentanone, dibutyl amine, triethylenetetramine, ammonium hydroxide, benzylamine, hydroxycitronellol, cyclohexanone, 2-butanone, pentane dione, dehydroacetic acid, or a mixture thereof.
[0048] Such formaldehyde scavengers are typically combined with a slurry containing said benefit agent containing delivery microcapsules, at a level, based on total slurry weight, of from about 2 wt. % to about 18 wt. %, from about 3.5 wt. % to about 14 wt. % or even from about 5 wt. % to about 13 wt. %.
[0049] Method of Application
[0050] This process enables the uniform application of microcapsules, and provides an enduring effect as illustrated previously, without the use of binding agents or adhesives which could adversely affect the feel and texture of flocked surfaces.
[0051] In an embodiment of the present invention, a first step towards transfer of the polymeric microcapsules on a hard flocked source is premixing polymeric microcapsule encapsulating a desired beneficial agent as a core material and water in 1:1 ratio in a high shear mixer for 15 minutes. This lower viscosity provides initial mixing to break aggregates making the subsequent dilutions easier to mix to a uniform suspension. Then, as a second step diluting by adding water to the premixed slurry to achieve a concentration of 10 to 20 grams of polymeric microcapsules/liter of slurry. A suspension stabilizer and/or wetting agent may be added at a concentration of 0.01 to 1.0%, at this point of time. As a third step, re-circulate the slurry for 15 minutes at a rate of 600 gph following which the flocked article is dipped into the agitated slurry, till it gets saturated with polymeric microcapsules. A final step is drying the excess water from the flocked article, using ambient or warm, dry air.
[0052] FIG. 1A is a flocked cloth hanger that was not properly coated and has unacceptable aesthetics due to white specs. FIG. 1B is a flocked cloth hanger which has been properly coated and has acceptable aesthetics due to absence of any white specs.
[0053] FIG. 2A is a detailed description of the dipping process in accordance with an embodiment of the present invention, described herein above, which steps and components have been given corresponding reference numerals for ease of reference. A first step towards the process of transferring polymeric microcapsules to a hard flocked surface is preparing a premix. Water 1 is mixed with Capsule slurry 2 in a high shear tank in a 1:1 ratio for 15 minutes to prepare a premix. Thereafter, in a second step the premix is transferred to a dilution tank 6 through a pipeline 4. The premix is diluted with water from tank 5 to achieve a desire dilution level preferable 10 to 20 g/l. The diluted slurry is re-circulated for 10 minutes through a slurry reservoir at a rate of 100 to 6000 gph, depending on the vessel size (600 gph in this example). Following dilution, in a third step, the diluted slurry is re-circulated to an open dipping vessel 11 through a pipeline 7, maintaining constant agitation through re-circulating at 100 to 6000 gph (600 gph in this example). Any hard flocked articles like a clothes hanger 9 or a closet item 10 can be dipped in the tank 11 for 1 second- to 10 minutes or until the article gets saturated.
[0054] According to an embodiment of the present invention, the capsule slurry suspension may be applied to flocked hangers via spraying or padding application in the third step, as long as agitation is maintained to assure consistent application.
[0055] FIG. 2B is a detailed description of the spraying process in accordance with an embodiment of the present invention, described herein above, which steps and components have been given corresponding reference numerals for ease of reference. A first step towards the process of transferring polymeric microcapsules to a hard flocked surface is preparing a premix. Water 1 is mixed with Capsule slurry 2 in a high shear tank in a 1:1 ratio for 15 minutes to prepare a premix. Thereafter, in a second step the premix is transferred to a dilution tank 6 through a pipeline 4. The premix is diluted with water from tank 5 to achieve a desire dilution level preferable 10-20 g/l. The diluted slurry is re-circulated for about 10 minutes through a slurry reservoir at a rate of 100 to 6000 gph, depending on the vessel size (600 gph in this example). Following dilution, in a third step, the diluted slurry is re-circulated to a spray arm 11 through a pipeline 7, maintaining constant agitation through re-circulating at 100 to 6000 gph (600 gph in this example). Suitable spray devices include HVLP or spray arm with a recovery tank. Spraying may be desirable for items that cannot be practically dipped.
[0056] FIG. 2C is a detailed description of the padding process in accordance with an embodiment of the present invention, described herein above, which steps and components have been given corresponding reference numerals for ease of reference. A first step towards the process of transferring polymeric microcapsules to a hard flocked surface is preparing a premix. Water 1 is mixed with Capsule slurry 2 in a high shear tank in a 1:1 ratio for 15 minutes to prepare a premix. Thereafter, in a second step the premix is transferred to a dilution tank 6 through a pipeline 4. The premix is diluted with water from tank 5 to achieve a desire dilution level preferable 10-20 g/l. The diluted slurry is re-circulated for 10 minutes through a slurry reservoir at a rate of 100 to 6000 gph, depending on the vessel size (600 gph in this example). Following dilution, in a third step, the diluted slurry is re-circulated to a padding application vessel 11 through a pipeline 7, maintaining constant agitation through re-circulating at 100-6000 gph (600 gph in this example). Padding is an application where more concentrated capsule slurry is transferred directly to a flocked surface. The advantage of this is that less water is used, which translates to less drying capacity. Padding application can be achieved with a nip roller, anilox roller or a sponge application (either automated or manually).
[0057] A low foam surfactant may be added to improve wetting, while the slurry is continuously agitated through a circulator 8 to keep the polymeric microcapsule suspended. In a final step, the coated articles are dried in ambient air or a dryer 12 to remove water.
[0058] The embodiments as disclosed and described in the application (including any accompanying claims, abstract and drawings) are intended to be illustrative and explanatory of the present invention. Modifications and variations of the disclosed embodiments, for example, of the apparatus and system employed (or to be employed) as well as the method used (or to be used), are possible; all such modifications and variations are intended to be within the scope of the present inventions.
[0059] Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[0060] A number of variations and modifications of the present invention can be used. It would be possible to provide for some features of the present invention without providing others.
[0061] The present invention, in various embodiments, configurations, and aspects, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, sub-combinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, configurations, and aspects, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments, configurations, or aspects hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and\or reducing cost of implementation.
[0062] The foregoing discussion of the present invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the present invention to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the present invention are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure.
[0063] The features of the embodiments, configurations, or aspects of the present invention may be combined in alternate embodiments, configurations, or aspects other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of the present invention.
[0064] Moreover, though the description of the present invention has included description of one or more embodiments, configurations, or aspects and certain variations and modifications, other variations, combinations, and modifications are within the scope of the present invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments, configurations, or aspects to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.
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A method of imparting enduring beneficial features to a hard flocked surface of an article is provided. The method includes encapsulating a desired beneficial agent as a core material in a polymeric microcapsule, and transferring polymeric microcapsule to the surface by a dipping, spraying, or padding application. The beneficial agent, after getting transferred to the surface of a hard flocked article, imparts long lasting performance, provides fragrance and may protect an article from odor, insect, pest, fungi, bacteria, viruses, and the like. The polymeric microcapsules deliver long lasting benefits to surfaces with flocking, such as clothes hangers. Also described is a process for manufacture of flocked items with benefit delivering polymer microcapsules, without the need for binders or adhesives. Benefit agents are released with shear force on the flocked surface, so they are released when used and provide long-lasting performance.
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BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates to radioactive well logging.
2. Description of Prior Art
U.S. Pat. Nos. 4,051,368; 4,169,979 and 4,486,658, all assigned to the assignee of the present application, involve determining horizontal brine flow speed of brines in a formation past a well borehole. In these patents formation brine is bombarded with neutrons from a neutron source in a sonde lowered by wire line into a well borehole. The neutrons are slowed to thermal energy level. When the brine is saline, the nuclear reaction 23 Na (n, γ) 24 Na occurs. One or more gamma ray detectors in the sonde measures gamma radiation from this nuclear reaction. The gamma radiation measurements are then processed to determine horizontal brine flow.
U.S. Pat. No. 4,051,368 related to determining the location and horizontal flow rate of earth formation brines past a well borehole. U.S. Pat. No. 4,169,979 related to measuring the azimuth and speed of horizontal brine flow by a well borehole. U.S. Pat. No. 4,486,658 related to displacing borehole brine away from the sonde, and thus the detectors, to remove any contribution of borehole salt water to the gamma ray measurements.
SUMMARY OF THE INVENTION
Briefly, with the present invention, it has been found that if there is also a vertical flow component of the activated brine, the horizontal flows calculated may be in error. Accordingly, the sonde is provided with at least two vertically spaced detectors or detector groups. The count ratio of gamma rays detected in the spaced detector groups is then monitored. If the count ratio changes, irradiated brine is moving towards one detector group and away from the other, indicating vertical brine flow. The vertically spaced detector groups also are used to determine the relative position of the irradiated zone to the center of the sonde detector system and also to locate the center of the sonde in the center of the irradiated zone. If the vertically flowing brine is formation brine, the horizontal flow measurement accuracy is affected. If the vertically flowing brine is borehole brine, background radiation measurements are changed, interfering with data interpretation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration showing a well logging sonde in a well borehole adjacent a formation for brine flow detection according to the present invention.
FIG. 2 is a schematic illustration showing the well logging sonde of FIG. 1 moved to a different position in the well borehole.
FIG. 3 is a schematic isometric view of one of the gamma ray detector clusters in the well logging sonde of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings, the letter A designates generally a well logging apparatus according to the present invention. The well logging apparatus A includes an elongated downhole sonde S and a surface electronic/processing unit P. The sonde S is suspended and moved by an armored well logging cable 10 in a well borehole 12 to a selected depth adjacent a formation 14 of interest. The well borehole 12 is typically filled with a brine 16 which may come from the formation 14 or one or more other formations 18 and 20. In some situations, the well borehole 12 may be lined with a casing 22 held in place by cement 24. The well logging cable 10 passes over a sheave wheel 26 coupled electrically or mechanically to the surface electronic processing unit P so the depth that which well logging measurements are made in the borehole 12 are known and recorded.
In the sonde S, a neutron source 30 is provided to bombard or irradiate the formation 14 of interest with neutrons. The source 30 is typically a continuous neutron source, such as an Actinium-Beryllium source, an Americium-Beryllium source or a Californium 252 source. The neutrons from source 30 bombard the borehole brine 16 and formation 14 and any brine in it and are slowed to thermal energy. When there is at least partial salinity in the borehole 16 or the formation 14, the thermal energy neutrons are captured by sodium atoms, giving rise to the nuclear reaction 23 Na (n, γ) 24 Na. The radioactive isotope 24 Na then decays by emission of gamma radiation at an energy level of 2.75 MeV. However, if flow rates are sufficiently high, it may be desirable instead to replace the continuous neutron source 30 with a deuterium-tritium accelerated neutron source and cause the 16 O (n, p) 16 N nuclear reaction using the decay of the isotope 16 N as the radiation tracer.
Located in the sonde at a spaced position along a vertical longitudinal axis 32 from a source 30 are a first gamma ray detector assembly 34 and a second gamma ray detector assembly 36. Gamma ray detector assemblies 34 and 36 are also spaced from each other a predetermined distance 38 which need only be on the order of one inch or so. At least one of the gamma ray detector assemblies 34 and 36 is formed from a cluster of three gamma ray detectors 40 (FIG. 3) displaced equidistant from the neutron source 30 longitudinally in the sonde S and disposed symmetrically along the vertical longitudinal axis 32 of the sonde S. In some situations, both gamma ray detector assemblies 34 and 36 may be formed of clusters of three such gamma ray detectors 40 configured in the manner shown in FIG. 3. In other situations, only one of the gamma ray detector assemblies 34 and 36 need be a cluster of three gamma ray detectors 40, the other such detector assembly being a single gamma ray detector 40 centered along the vertical longitudinal axis 32 of the sonde S and spaced from the other gamma ray detector assembly by the distance 38. The gamma ray detectors 40 in each of the assemblies 34 and 36 are, for example, sodium iodide, thallium-activated scintillation crystals 42, each optically coupled to an associated photo-multiplier tube 44.
As is known in the art, gamma rays entering a scintillation crystal interact with the crystal to produce light flashes, or scintillations, whose intensity is functionally related to the gamma ray energy of the entering radiation. The light flashes are then detected by the photo-multiplier tube 44 to generate voltage pulses proportional in magnitude or height to the intensity of the corresponding light flashes. A succession of pulses is thereby produced in the detector 40 with the height of the pulses being proportional to the energy of the incoming gamma ray. The pulse streams from each detector 40 in the detector assemblies 34 and 36 are then conducted to signal processing equipment located in an electronic package 46 located toward an upper end of the sonde S. A set of pulse streams from each gamma ray detector 40 in the gamma ray detector assemblies 34 and 36 can then be multiplexed or encoded by conventional well logging transmission schemes and transmitted via the well logging cable 10 to the electronic/processing unit P.
It should be understood that appropriate power supplies are provided at the surface and connected to the electronics package 46 by suitable conductors within the well logging cable 10 to provide operating power for the electronics package 46 and the gamma ray detector assemblies 34 and 36. Alternatively, power supplies may be included within the sonde S for the electronics 46 and the gamma ray detector assemblies 34 and 36. Since these power supplies are conventional, they are not shown in detail in the drawings. The pulse streams from the gamma ray detector assemblies 34 and 36 may, if desired, pass to a downhole comparator appropriately biased to reject all voltage pulses of height corresponding to incident gamma rays of energy levels less than 2.65 MeV or other suitable energy level before being sent via the logging cable 10 to the surface electronics/processing unit P.
Between the neutron source 30 and the gamma ray detector assemblies 34 and 36 in the sonde S is shielding material 50 of a suitable type to prevent direct irradiation of the scintillation crystal 42 by neutrons from the neutron source 30. Suitable shielding materials are those with a high hydrogen content, such as paraffin or other polymolecular hydrocarbon structure. The high hydrogen content serves to slow down or rapidly attenuate neutron population from the neutron source 30, preventing such a thermalized neutron population from reaching the scintillation crystal 42. Strong thermal neutron absorbers such as cadmium may also be interposed within the hydrogenate shielding material, if desired. Further, additional shielding 52 is located between the source 30 and the electronics package 46 to protect same.
When it is desired to measure the azimuth of flow by the borehole 12, a gyrocompass 58 of the type disclosed in U.S. Pat. No. 4,169,979 is included in the sonde S. The teachings of this prior art patent in this regard are incorporated herein by reference.
As has been set forth above, if the brine in formation 14 or the borehole 16 is at least partially saline, the neutrons bombarding from source 30 after being slowed to thermal energy are captured by 23 Na, giving rise to the nuclear reaction 23 Na (n, γ) 24 Na. After the formation 14 is bombarded with neutrons, the sonde S is raised by wire line 10 to a position (FIG. 2) where the gamma ray detectors 34 and 36 are adjacent the formation 14. The radioactive isotope 24 Na decays by emission of gamma radiation at an energy level of 2.75 MeV which can be detected by the gamma ray detector assemblies 34 and 36 to form a record of the presence and intensity of such gamma radiation.
With the present invention, it has been found that if there is any vertical flow of the neutron bombarded borehole brine 16 or brine in the formation 14, measures of horizontal brine flow past the borehole 12 may be erroneously affected. Accordingly, the first and second gamma ray detector groups 34 and 36 vertically spaced from each other by the distance 38 are used to detect any such vertical brine flow. Any such vertical brine flow past the gamma ray detector assemblies 34 and 36 by its nature flows away from one detector group while flowing toward the other.
The gamma ray detector groups 34 and 36 are separately coupled to associated pulse height analyzer/recorder apparatus 60 and 62, respectively, in the surface electronics/processing unit P. The gamma rays detected by the first gamma ray detector assembly 34 are received, stored, analyzed and recorded in analyzer/recorder unit 60 while the gamma rays detected in gamma ray detector assembly 36 are received, stored, analyzed and recorded in analyzer/recorder unit 62. If desired, a single analyzer/recorder unit may be used, with the different gamma ray detector counts being received and stored in different storage areas in a single memory.
The analyzer/recorder units 60 and 62 provide output signals indicative of the gamma radiation counted to a ratio circuit 66 which forms an indication of the ratio of the gamma rays detected in the respective gamma radiation detector assemblies 34 and 36. If the ratio of the gamma radiation detected by the two detector assemblies differs from unity, the ratio circuit will so indicate, forming a measure of the relative vertical brine flow in the borehole 12. The well logging apparatus A can also be used to determine whether the sonde S is centered in the radiated zone 14 of interest by monitoring the output of the ratio circuit 66 as the sonde S is moved with respect to the radiated zone 14. When the output of the ratio circuit 66 becomes unity, the sonde S is centered in the irradiated zone 14 of interest.
If irradiated brine is flowing in the borehole 12 from a point 70 (FIG. 2) down past the gamma ray detector assemblies 34 and 36, the gamma radiation count rate in detector 34 increases before the counting rate in detector 36 increases. The converse is true if the brine flow is in the reverse direction. Further, if formation brine flows down outside the casing 22 in a channel 74, the count rate in gamma ray detector assembly 36 becomes higher than the count rate in gamma ray detector assembly 34.
The output count of ratio circuit 66 can also be used to determine the relative position of irradiated zone 14 with respect to the longitudinal center of the spaced gamma ray assemblies 34 and 36. In addition, according to the present invention, vertical brine flow in the formation which might affect the accuracy of calculated horizontal brine velocity flow measurements can be detected. Also, any vertical flow of activated borehole brine 16, which could result in a fluctuating background radiation level which might otherwise interfere with the quality of data interpretation, can be detected.
Having described the invention above, various modifications of the techniques, procedures, material and equipment will be apparent to those in the art. It is intended that all such variations within the scope and spirit of the appended claims be embraced thereby.
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Brines in earth formations in the vicinity of a well borehole are bombarded with neutrons. The neutrons are slowed to thermal energy and captured by sodium atoms in the brine according to the nuclear reaction 23 Na (n, γ) 24 Na. Spaced arrays of gamma ray detectors in a sonde in the borehole obtain gamma ray measurements following activation to obtain measurements of horizontal brine flow past the borehole. The detector arrays are vertically spaced from each other along the axis of the sonde. Changes in the count ratios of the detector arrays indicates a vertical flow of the brine.
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RELATED APPLICATIONS
[0001] This application claims priority to PCT/UA2014/000046 filed on Apr. 30, 2014 and Ukrainian application number a201403103 filed on Mar. 31, 2014 and incorporated herewith by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to deep-water underwater transportation in mining operations, and can be used for the placement of geological survey and mining equipment.
BACKGROUND OF THE INVENTION
[0003] The basic requirements to geological survey and mining technologies are reliability and minimal environmental damage caused by conveyance of near-bottom mineralized waters with silt to the surface in the course of extraction of minerals and as a result of dumping the mining refuse to the near-surface ocean. Any production unit designated for collection of ferromanganese nodules shall comply with the following requirements: bottom areas handling at the speed of 10 . . . 15 sq.m./sec.; no-failure movement and operation in case of any undetected obstructions within the nodules collection site.
[0004] In order to ensure effective collection of ferromanganese nodules using computer-aided procedures, the average speed of the collecting unit should not exceed 0.5 m/sec., and the unit body should move at the level of 5 meters above the ocean bottom. The facilities for placement of exploration and extraction equipment are known in the prior art, including: “FREE-FALL BOTTOM SAMPLER”0 U.S. Pat. No. 3,572,129 (A) (BEAR CREEK MINING CO) Mar. 23, 1971; “MODULE AND PROCESS FOR UNDERWATER MINING OF MINERAL BEARING SAND AND GRAVEL” U.S. Pat. No. 3,731,975 (A) (QVA CORP, US) Jul. 8, 1973[6].
[0005] The known facilities are heavier and lack strength and resistance, meaning that they can be used at great depth (about 6,000 meters) to a limited extent. The most similar in function underwater transport module comprising a body, ballast tanks with adjustable buoyancy, and a system for pumping a working medium (i.e. overboard water) in and out [“Subsea Platform” RU2182212 (C2) (May 10, 2002] is already known in the prior art.
[0006] The module frame is made from arched structure elements in a shape of a truncated triangular pyramid, and the V-shaped support beams are mounted rigidly to the frame, while foamed polyurethane blocks are mounted at the top of the frame for buoyancy purposes. The ballast tanks of the module are configured in the form of a torus-shaped floating hull and pipe sections. A disadvantage of the previously known unit is its insufficient strength, buoyancy and maneuverability; thus it cannot be used at great depth (6,000 m).
SUMMARY OF THE INVENTION
[0007] This invention is focused on the following objective: to design and build an underwater transport module that can be used at great depth in a safe, reliable and environmentally friendly manner by virtue of its improved strength, buoyancy and maneuverability. This engineering challenge shall be solved as follows: the underwater transport module, comprising a body, ballast tanks with adjustable buoyancy and a system for pumping a working medium in and out, said working medium being water from outside the transport module shall contain, according to the invention, the body having a streamlined shape and made of syntactic foam (a composite based on hollow glass microspheres), ballast tanks configured in the form of a multi-tiered ballast system comprised of a plurality of spherical vessels, each of which consists of two interconnected hemispheres, the cavities of the spherical vessels being connected to one another and to the system for pumping a working medium in and out, and the underwater transport module further comprises hydraulic propellers for cruising and maneuvering, said propellers being connected to the system for pumping a working medium in and out.
[0008] The optimal weight—strength—buoyancy—maneuverability ratio was reached as a result of the following: the body is made of the syntactic material, the ballast tanks form the multi-tiered ballast system comprising a series of spherical vessels, each of which consists of two interconnected hemispheres, and the cavities of the spherical vessels are connected to one another and to the system for pumping a working medium in and out.
[0009] The hydraulic propellers for cruising and maneuvering, connected to the system for pumping a working medium in and out, support the movement and maneuvering of the underwater transport module while carrying out various technological operations at the given depth and zero buoyancy, for example, 5 meters over the bottom, thus mitigating the adverse environmental impact of the technological processes.
[0010] The claimed design of the underwater transport module is characterized by an optimal weight—strength—buoyancy—maneuverability ratio, making it possible to conduct various technological processes at great depth (6,000 m) without any harm or damage to the environment. The underwater transport module has additional distinctive parameters which improve or increase technical results.
[0011] The fact that the body is made as one piece or assembled of individual units made from the syntactic material, with the density not exceeding ρ=700 kg/c.m. and with the compressive strength of at least σ=90 MPa, being the composite based on a binding agent—polyester resins with a filler (hollow glass microspheres 0.01-10.0 micrometers in size), as well as that the hemispheres are made from steel with the yield point of at least 1,200 MPa, guarantees high strength and proper buoyancy of the underwater transport module.
[0012] The fact that the hemispheres of spherical vessels have flanges and portholes in walls with the axes located at an angle of α=90° to each other and where the threaded bushings are fixed, and that these hemispheres are interconnected with flanges and connected by bolt joints, makes it possible to install the entire system promptly in the course of its manufacturing. In the underwater transport module, the adjacent spherical vessels are connected to one another with the hollow threaded ties. The spherical vessels form a “honeycomb-type” multi-tiered ballast system. Such solution decreases working hours and manpower efforts for the system installation and dismantling and improves its maintainability.
[0013] In the underwater transport module, the multi-tiered ballast system is filled with a syntactic material, and, in conjunction with the body, it forms a one-piece unit. Such layout ensures convenience of ballast system installation within the body. The underwater transport module may additionally comprise a mounted changeable work tool with a drive, receiving and collecting bunkers connected to one another with a screw conveyor, and a discharge device.
[0014] The system for pumping a working medium in and out additionally comprises a high pressure pump with the drive, the drive of the changeable work tool configured in the form of a hydroturbine, hydraulically connected to the system for pumping a working medium in and out from the “honeycomb-type” multi-tiered system, a system of autonomous mobile power-generating units and an autonomous urgent emersion system. Such solution is characterized by improved reliability and reduced time for the replacement of power-generating units and technical maintenance of the equipment.
[0015] Such improvement allows installing, onboard the underwater transport module, an effective extraction vehicle for collection of minerals with the mobile power supply systems and autonomous urgent emersion system in case of emergency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Further on, you will find a detailed description and explanation of the invention, together with references to drawings and layouts, where:
[0017] FIG. 1 illustrates the underwater transport module (general layout);
[0018] FIG. 2 illustrates the underwater transport module with an underwater manned vehicle;
[0019] FIG. 3 illustrates a longitudinal section of the underwater transport module;
[0020] FIG. 4 illustrates a spherical tank of the multi-tiered ballast system;
[0021] FIG. 5 illustrates the multi-tiered ballast system; and
[0022] FIG. 6 illustrates the underwater transport module ready for nodules transportation.
DESCRIPTION OF PREFERRED EMBODIMENT
[0023] The underwater transport module ( FIG. 1 ) comprises the body 1 , ballast tanks 2 ( FIG. 2 ) in the form of the multi-tiered ballast system, and the system 3 for pumping a working medium in and out ( FIG. 3 ). The multi-tiered ballast system consists of a number of spherical vessels 4 ( FIG. 4 ), each of which comprises two interconnected hemispheres 5 ( FIG. 5 ), while the cavities 6 of the spherical vessels 4 within the multi-tiered ballast system are connected to one another and to the system 3 for pumping a working medium in and out, to ensure negative buoyancy for the module immersion or positive buoyancy for its emersion, or zero buoyancy in the course of immersion to the specified operating depth or for immersion depth stabilization in case the module weight varies.
[0024] The body 1 is streamlined and monolith or may be assembled of separate units and made of the syntactic material; and the hemispheres 5 of the spherical vessels 4 within the multi-tiered ballast system are made of steel with the yield point equal to or exceeding 1,200 MPa.
[0025] Hemispheres 5 of the spherical vessels 4 within the multi-tiered ballast system have flanges 8 ( FIG. 4 ) and portholes 9 in walls with the axes located at an angle of α=90° to each other and the threaded bushings 10 fixed, and the hemispheres 5 are connected to one another with the flanges 8 and connected by bolt joints 11 , and, as an assembly, form spherical vessels 4 within the multi-tiered ballast system.
[0026] The adjacent spherical vessels 4 within the multi-tiered ballast system are connected to one another with the hollow threaded ties 12 ( FIG. 5 ), which connect them to the threaded bushings 10 of the hemisphere 5 . The multi-tiered ballast system is filled with a composite syntactic material and, together with the body 1 , forms the one-piece unit 13 ( FIG. 3 ).
[0027] The module also comprises hydraulic propellers 7 for cruising and maneuvering ( FIG. 1 ) connected to the system 3 for pumping a working medium in and out for the module movement and maneuvering purposes. According to the specifications above (modification 1), the underwater transport module is capable of carrying out transport and lifting operations at the depth of 6,000 meters.
[0028] For the extraction and handling of minerals (modification 2), the underwater transport module may be additionally equipped with one of the mounted changeable work tools 14 ( FIG. 1 ) with the drive 15 of the mounted changeable tool ( FIG. 6 ), receiving bunker 16 ( FIG. 3 ), and collecting bunker 17 , connected together by the screw conveyor 18 , as well as the discharge device 19 .
[0029] This modification makes it possible to carry out efficient collection of minerals such as ferromanganese nodules. The system 3 for pumping a working medium in and out also contains a high pressure pump 20 with a high pressure pump drive 21 ( FIG. 3 ).
[0030] The drive 15 of the mounted changeable work tool 14 is implemented in the form of a hydroturbine hydraulically connected to the system 3 for pumping a working medium in and out.
[0031] The underwater transport module may be equipped with the autonomous power supply system 22 and the urgent emersion system 23 ( FIG. 1 ). The mounted changeable work tool 14 may be implemented in the form of a chain conveyor with ladles 24 and chains 25 ( FIG. 3 ). The ladles 24 are gimbal-mounted to the chain 25 and adapted to flexible turning in case of contact with any obstruction in the course of the module movement, and capable of returning to the initial position.
[0032] The ladles 24 may be implemented as a series of chains connected together.
[0033] According to the above specifications (modification 2), the underwater transport module in the course of minerals development and in case of use of the mounted changeable work tool 14 has zero buoyancy and remains at the level of 5 meters above the bottom at the depth of 6,000 meters.
[0034] With the loading of the collecting bunker 17 and increasing the module weight, the system 3 for pumping a working medium in and out responds to all the changes, dewaters and maintains the operating location at the level of 5 meters over the ocean bottom.
[0035] Water-jet nozzles 26 ( FIG. 3 ) are located at the bottom of the body 1 . The underwater transport module may be accompanied with the underwater manned vehicle 27 ( FIG. 2 ). The nodules storage bunker has collecting bunker portholes 28 ( FIG. 3 ). The equipment operates as follows:
[0036] The module initial location is on the surface of the water area near the support vessel. In the course of unloading after the previous operating cycle, the high pressure pump 20 of the system 3 for pumping a working medium in and out within the multi-tiered ballast system shall be turned on. Upon the unloading completion and attainment of the specified negative buoyancy, the module shall start controlled and operated immersion to the bottom of the water area. The underwater transport module in modification 1 shall operate as a carrier of cargos or underwater facilities. The underwater transport module in modification 2 shall operate as an autonomous extraction module. Upon attainment of the specified immersion depth (5 meters above the bottom), the module shall be capable of moving and maneuvering while carrying out various technological operations at the specified depth and zero buoyancy.
[0037] The hydraulic propellers 7 for cruising and maneuvering ensure autonomous movement of the module along the trajectory within the certain pathway. Then, the drive 15 of the mounted changeable work tool 14 shall be automatically turned on to start collecting ferromanganese nodules into the receiving bunker 16 and carrying the same to the collecting bunker 17 .
[0038] The chains 25 of the mounted changeable work tool 14 with ladles 24 shall move with respect to the body 1 using the regulated drive 15 of the mounted changeable work tool and, while hanging down, slide over the bottom.
[0039] The ladles 24 shall ladle out ferromanganese nodules together with the silt layer, and this silt shall run through lattice walls and bottom of the ladles 24 , while the ferromanganese nodules shall be conveyed to the collecting bunker 17 . The module designed according to the above specifications is capable of surmounting any juts of 1.5 . . . 2 m high, without suspending the ferromanganese nodules collection process; and the chains 25 with ladles 24 slide over the surface of such juts. Pits and clefts of any dimension shall not be treated as obstacles for the module movement, even if the base relief is quite rugged, since the ladles 24 are gimbal-mounted to the chain 25 , making it possible to conduct a flexible turn in case of any contact with obstructions and to return to the initial position.
[0040] The function of operational control over the chain 25 speed and the module location over the bottom makes it possible to control the speed of the underwater vehicle. In the course of the underwater transport module operation, the mounted changeable work tool 14 shall be in its operating position ( FIG. 1 ), and while the underwater transport module is immersing or emerging the mounted changeable work tool 14 shall be in its transport position ( FIG. 6 ).
[0041] The water-jet nozzles 26 mounted to the bottom of the body 1 make it possible to carry the biomass and benthic life (possibly found on the surface of ferromanganese nodules) away from the area where the development operations are conducted, by throwing the same to both sides of the chain ladles, thus mitigating the adverse environmental impact of such operations.
[0042] The operation of the underwater transport module may be controlled from two mobile control points. The first control point comprises the equipment for the underwater transport module operation: an interferometric hydrolocator with lateral visibility, a frontal echo sounder, a hydrolocator with all-round visibility and a multibeam one, as well as a profilograph. These systems are designated to collect the bottom characteristics data for the module movement control purposes. The navigation system may be equipped with an on-board satellite system and an underwater sound system. A balanced Doppler-inertial on-board system makes it possible to carry out the adjustment with the help of data from the Doppler log, where the module speed varies relative to the ground and water. These data shall allow maintaining the depth level required to carry out the extraction activities. A DPRS system is used for the above-water movement of the module. The acoustic navigation system allows identifying the module location relative to bottom beacons.
[0043] The second control point may be installed in the underwater transport module in order to fulfill any task with the use of videos from the module video cameras. At the upper side of the underwater transport module there may be a platform for various types of underwater manned vehicles 27 (whose operational depth is about 6,000 meters). The platform may be equipped with a data transmission system to transfer the data to the underwater manned vehicle 27 , from where the module is operated manually with the help of a video image. The underwater manned vehicle 27 is capable of emerging together with the underwater transport module, or independently using the urgent emersion program.
[0044] The claimed underwater transport module prevents the movement of silt and bottom water to the surface, since the collecting bunker 17 has the collecting bunker portholes 28 through which (in the course of the underwater module emersion) the overboard water is released, thus providing continuous interchange and displacement of water layers during the emersion process.
[0045] The module is designated to collect ferromanganese nodules at the level of 3 . . . 5 meters over the bottom, depending on the bottom slant, using special chain-type ladles 24 that collect only ferromanganese nodules and downstock the nodules (undamaged) into the receiving bunker 16 . After the module completes the task (i.e. the specified quantity of nodules is collected), the module emerges and subsequently gets unloaded at the support vessel. The autonomous power supply system 22 of the module may comprise three separate mobile units, each unit equipped with an engine, fuel tanks, a generator, a high pressure pump system, a steering system, and navigation equipment.
[0046] All elements of the power supply system are installed within a special container and covered with the composite syntactic material. All of them together form a one-piece unit with manholes for maintenance purposes. In case of failure of any of power-generating units, two other units can operate for urgent emersion of the underwater transport module, in case of breakdown of two power-generating units, the one remaining is capable of conducting urgent emersion of the underwater transport module. Against the possibility of failure of all power-generating units, the module is equipped with the autonomous urgent emersion system 23 , comprising a set of accumulators and capable of pumping the water out of the ballast system to ensure the transport module positive buoyancy. The power-generating unit maintenance operations may be carried out by means of replacement of such units and their subsequent repair aboard the support vessel.
[0047] The design carrying capacity of the underwater transport module is 300 tons. A set of underwater transport modules (modification 2) may form a “production complex”. Such production complex can comprise two ore carriers and two underwater transport modules (modification 2) being the autonomous production units. The use of the claimed invention is possible subject to construction of underwater transport modules with a carrying capacity of up to 1,000 tons.
INDUSTRIAL APPLICATION OF THE INVENTION
[0048] The given details prove a possibility of industrial application of the underwater transport module that (in modification 1) may be used (as a carrying unit) for underwater conveyance and placement of geological survey and mining equipment, or (in modification 2) for collection of nodules from the ocean bottom.
[0049] List of designations
[0050] 1 ) body
[0051] 2 ) ballast tanks
[0052] 3 ) system for pumping a working medium in and out
[0053] 4 ) spherical vessels
[0054] 5 ) hemispheres
[0055] 6 ) cavities of spherical vessels
[0056] 7 ) hydraulic propellers for cruising and maneuvering
[0057] 8 ) flanges of hemisphere spherical vessels
[0058] 9 ) portholes in the hemisphere walls
[0059] 10 ) threaded bushings
[0060] 11 ) bolt joints
[0061] 12 ) hollow threaded ties
[0062] 13 ) one-piece unit
[0063] 14 ) mounted changeable work tool
[0064] 15 ) drive of the mounted changeable work tool
[0065] 16 ) receiving bunker
[0066] 17 ) collecting bunker
[0067] 18 ) screw conveyor
[0068] 19 ) discharge device
[0069] 20 ) high pressure pump
[0070] 21 ) high pressure pump drive
[0071] 22 ) autonomous power supply system
[0072] 23 ) urgent emersion system
[0073] 24 ) ladle
[0074] 25 ) chain
[0075] 26 ) water-jet nozzle
[0076] 27 ) underwater manned vehicle
[0077] 28 ) collecting bunker portholes
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This invention relates to deep-water underwater transportation in mining operations, and can be used for the placement of geological survey and mining equipment. The present underwater transport module comprises a body ( 1 ), ballast tanks ( 2 ) with adjustable buoyancy, and a system ( 3 ) for pumping a working medium in and out, said working medium being water from outside the transport module. According to the invention, the body ( 1 ) has a streamlined shape and is made of syntactic foam (a composite based on hollow glass microspheres), the ballast tanks ( 2 ) are configured in the form of a multi-tiered ballast system comprised of a plurality of spherical vessels ( 4 ), each of which consists of two interconnected hemispheres ( 5 ), the cavities ( 6 ) of the spherical vessels ( 4 ) being connected to one another and to the system ( 3 ) for pumping a working medium in and out, and the underwater transport module further comprises hydraulic propellers ( 7 ) for cruising and maneuvering, said propellers being connected to the system (3) for pumping a working medium in and out. The invention provides for the reliable and environmentally friendly use of a transport module at great depths as a result of enhanced durability, buoyancy and maneuverability.
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FIELD OF THE INVENTION
[0001] This invention relates generally to an efficient process for the preparation of a benzisoxazolyl-pyrazole. Benzisoxazolyl-pyrazoles are useful as factor Xa inhibitors.
BACKGROUND OF THE INVENTION
[0002] Factor Xa inhibitors like those of Formula Ia shown below:
[0003] WO98/57951 describes the synthesis of the compound of Formula Ia, as its trifluoroacetic acid salt, as follows:
[0004] In the above procedure, the pyrazole carboxylic acid and aniline are coupled and isolated as a free base. The 3-cyano-4-fluorophenyl group of the resulting product is then converted to 1-aminobenzisoxazole. One problem with this procedure is that the acid-aniline coupling product is difficult to purify. A second problem is that the conversion to the 1-aminobenzisoxazole moiety requires the presence of a strong, expensive base such as KOt-Bu.
[0005] It can be seen that the preparation of a compound of Formula I is difficult. Thus, it is desirable to find an efficient synthesis of such a compound.
SUMMARY OF THE INVENTION
[0006] Accordingly, one object of the present invention is to provide a novel process for preparing a compound of Formula I.
[0007] It is another object of the present invention to provide intermediates that are useful in preparing a compound of Formula I.
[0008] It is another object of the present invention to provide novel salt, crystalline, and solvent forms of Formula I.
[0009] It is another object of the present invention to provide pharmaceutical compositions comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of at least one of the compounds of the present invention or a pharmaceutically acceptable salt thereof.
[0010] It is another object of the present invention to provide a method for treating thromboembolic disorders comprising administering to a host in need of such treatment a therapeutically effective amount of at least one of the compounds of the present invention or a pharmaceutically acceptable salt thereof.
[0011] It is another object of the present invention to provide novel compounds for use in therapy.
[0012] It is another object of the present invention to provide the use of novel compounds for the manufacture of a medicament for the treatment of a thromboembolic disorder.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] Thus, in an embodiment, the present invention provides a novel process for making a compound of Formula I:
[0014] comprising:
[0015] (c) contacting a compound of Formula IVa with maleic acid to form a compound of Formula IV;
[0016] (d) converting a compound of Formula IV to a compound of Formula V; and,
[0017] (e) forming a compound of Formula I.
[0018] In a preferred embodiment, in (c), contacting with maleic acid is performed in the presence of a first solvent, ethyl acetate.
[0019] In another preferred embodiment, in (c), a second solvent, 1-chlorobutane, is added to enhance precipitation.
[0020] In another preferred embodiment, (d) is performed by contacting a compound of Formula IV with HONHCOCH 3 in the presence of a base and a solvent.
[0021] In another preferred embodiment, the base is selected from K 2 CO 3 , Na 2 CO 3 , KHCO 3 , NaHCO 3 , KF, NaOH, and KOH.
[0022] In another preferred embodiment, the base is K 2 CO 3 .
[0023] In another preferred embodiment, in (d), the solvent is selected from DMSO, DMAC, N-methylpyrrolidinone, and DMF.
[0024] In another preferred embodiment, in (d), the solvent is DMF, comprising: 0.5 to 50% by volume of water.
[0025] In another preferred embodiment, in (d), the solvent is DMF, comprising: 10, 11, 12, 13, 14, to 15% by volume of water.
[0026] In another preferred embodiment, in (d), the solvent is DMF, comprising: 15% by volume of water.
[0027] In another preferred embodiment, (e) is performed by contacting a compound of Formula V with HCl in a solvent selected from methanol, acetonitrile, isopropyl alcohol, ethanol, propanol, acetone, methyl isobutyl ketone (MIBK), 2-butanone, and water.
[0028] In another preferred embodiment, (e) is performed by contacting a compound of Formula V with HCl in ethanol.
[0029] In another preferred embodiment, the compound of Formula I is a mono-HCl salt.
[0030] In another preferred embodiment, the compound of Formula I is crystalline.
[0031] In another preferred embodiment, the compound of Formula I is a solvate selected from ethanol, propanol, isopropanol, acetone, MIBK, 2-butanone, and water.
[0032] In a more preferred embodiment, the compound of Formula I is an ethanol solvate.
[0033] In another embodiment, the present invention provides a novel process for making a compound of Formula IVa:
[0034] comprising:
[0035] (b) coupling compounds of Formulas II and III to form a compound of Formula IVa.
[0036] In another preferred embodiment, the compound of Formula IVa is used without purification in (c).
[0037] In another preferred embodiment, (b) is performed by contacting a compound of Formula II with an acid activator, in a solvent and a first base, followed by contacting the resulting solution with a compound of Formula III.
[0038] In another preferred embodiment, (b) is performed by contacting a compound of Formula II with oxalyl chloride in acetonitrile and pyridine, followed by contacting the resulting solution with a compound of Formula III.
[0039] In another preferred embodiment, after a compound of Formula II has been contacted with a compound of Formula III, a second base is added to the reaction solution.
[0040] In another preferred embodiment, the second base is diisopropylethylamine.
[0041] In another embodiment, the present invention provides a novel process for making a compound of Formula II:
[0042] comprising:
[0043] (a) contacting a compound of Formula VI with a compound of Formula VII to form a compound of Formula VIII; and,
[0044] (a 1 ) converting a compound of Formula VIII to a compound of Formula II.
[0045] In another embodiment, the present invention provides a novel compound of Formula I:
[0046] wherein I is a mono-HCl salt.
[0047] In another preferred embodiment, the compound of Formula I is crystalline.
[0048] In another preferred embodiment, the compound of Formula I is an ethanol solvate.
[0049] In another embodiment, the present invention provides a novel compound of Formula IV:
[0050] In another embodiment, the present invention provides a novel compound of Formula Va:
[0051] or a pharmaceutically acceptable salt form thereof.
[0052] In another embodiment, the present invention provides novel pharmaceutical compositions, comprising: a pharmaceutically acceptable carrier and a therapeutically effective amount of a compound of the present invention or a pharmaceutically acceptable salt form thereof.
[0053] In another embodiment, the present invention provides a novel method for treating a thromboembolic disorder, comprising: administering to a patient in need thereof a therapeutically effective amount of a compound of the present invention or a pharmaceutically acceptable salt form thereof.
[0054] In another embodiment, the present invention provides a compound of the present invention for use in therapy.
[0055] In another embodiment, the present invention provides the use of a compound of the present invention for the manufacture of a medicament for the treatment of a thromboembolic disorder.
DEFINITIONS
[0056] As used herein, the following terms and expressions have the indicated meanings. It will be appreciated that the compounds of the present invention may contain an asymmetrically substituted carbon atom, and may be isolated in optically active or racemic forms. It is well known in the art how to prepare optically active forms, such as by resolution of racemic forms or by synthesis from optically active starting materials. All chiral, diastereomeric, and racemic forms and all geometric isomeric forms of a structure are intended, unless the specific stereochemistry or isomer form is specifically indicated.
[0057] The processes of the present invention are contemplated to be practiced on at least a multigram scale, kilogram scale, multikilogram scale, or industrial scale. Multigram scale, as used herein, is preferably the scale wherein at least one starting material is present in 10 grams or more, more preferably at least 50 grams or more, even more preferably at least 100 grams or more. Multikilogram scale, as used herein, is intended to mean the scale wherein more than one kilogram of at least one starting material is used. Industrial scale as used herein is intended to mean a scale which is other than a laboratory scale and which is sufficient to supply product sufficient for either clinical tests or distribution to consumers.
[0058] The term “substituted,” as used herein, means that any one or more hydrogens on the designated atom are replaced with a selection from the indicated group, provided that the designated atom's normal valency is not exceeded, and that the substitution results in a stable compound. When a substituent is keto (i.e., ═O), then 2 hydrogens on the atom are replaced. Keto substituents are not present on aromatic moieties. When a ring system (e.g., carbocyclic or heterocyclic) is said to be substituted with a carbonyl group or a double bond, it is intended that the carbonyl group or double bond be part (i.e., within) of the ring.
[0059] The present invention is intended to include all isotopes of atoms occurring in the present compounds. Isotopes include those atoms having the same atomic number but different mass numbers. By way of general example and without limitation, isotopes of hydrogen include tritium and deuterium. Isotopes of carbon include C-13 and C-14.
[0060] The reactions of the synthetic methods claimed herein may be preferably carried out in the presence of a base, the base being any of a variety of bases, the presence of which in the reaction facilitates the synthesis of the desired product. Suitable bases may be selected by one of skill in the art of organic synthesis. Suitable bases include, but are not limited to, inorganic bases including, but not limited to, alkali metal, alkali earth metal, thallium, and ammonium hydroxides, alkoxides, phosphates, and carbonates, including, but not limited to, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, cesium carbonate, thallium hydroxide, thallium carbonate, tetra-n-butylammonium carbonate, and ammonium hydroxide.
[0061] The reactions of the synthetic methods claimed herein may be carried out in solvents that may be readily selected by one of skill in the art of organic synthesis, the solvents generally are any one that is substantially non-reactive with the starting materials (reactants), intermediates, or products at the temperatures at which the reactions are carried out, i.e., temperatures which may range from the solvent's freezing temperature to the solvent's boiling temperature. A given reaction may be carried out in one solvent or a mixture of more than one solvent. Depending on the particular reaction step, suitable solvents for a particular reaction step may be selected.
[0062] Suitable ether solvents include: dimethoxymethane, tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, furan, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, or t-butyl methyl ether.
[0063] Suitable aprotic solvents may include, by way of example and without limitation, tetrahydrofuran (THF), dimethylformamide (DMF), dimethylacetamide (DMAC), 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU), 1,3-dimethyl-2-imidazolidinone (DMI), N-methylpyrrolidinone (NMP), formamide, N-methylacetamide, N-methylformamide, acetonitrile, dimethyl sulfoxide, propionitrile, ethyl formate, methyl acetate, hexachloroacetone, acetone, ethyl methyl ketone, ethyl acetate, sulfolane, N,N-dimethylpropionamide, tetramethylurea, nitromethane, nitrobenzene, or hexamethylphosphoramide.
[0064] The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
[0065] As used herein, “pharmaceutically acceptable salts” refer to derivatives of the disclosed compounds wherein the parent compound is modified by making acid or base salts thereof. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic groups including, but not limited to, amines, and alkali or organic salts of acidic groups including, but not limited to, carboxylic acids. The pharmaceutically acceptable salts include conventional non-toxic salts or quaternary ammonium salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. For example, conventional non-toxic salts include those derived from inorganic acids including, but not limited to, hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, and nitric; and the salts prepared from organic acids including, but not limited to, acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, and isethionic.
[0066] The pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound that contains a basic or acidic moiety by conventional chemical methods. Generally, salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile is preferred. Lists of suitable salts are found in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418, the disclosure of which is hereby incorporated by reference.
[0067] As used herein, “treating” or “treatment” cover the treatment of a disease-state in a mammal, particularly in a human, and include: (a) preventing the disease-state from occurring in a mammal, in particular, when such mammal is predisposed to the disease-state but has not yet been diagnosed as having it; (b) inhibiting the disease-state, i.e., arresting it development; and/or (c) relieving the disease-state, i.e., causing regression of the disease state.
SYNTHESIS
[0068] The processes of the present invention can be practiced in a number of ways depending on the solvent, base, and temperature chosen. As one of ordinary skill in the art of organic synthesis recognizes, the time for reaction to run to completion as well as yield will be dependent upon all of the variables selected. The following schemes show a representation of the overall sequence of the present invention.
[0069] Preparation of Formula VIII:
[0070] VI can be converted to VIII by a novel hydrazine in situ trapping procedure. The hydrazine intermediate can be prepared by treating VI with HCl and NaNO 2 . Preferably, VI is added to a cooled (e.g., −10 to −5° C.) solution of HCl. The NaNO 2 can then added and the solution preferably maintained at a temperature of from 0-10° C. At this point, AcOH can be added to the solution. SnCl 2 .2H 2 O can then be added to complete formation of the hydrazine. The resulting product may be isolated or used in situ. Preferably, it is used in situ.
[0071] VIII can then be formed by addition of VII to the newly formed hydrazine. This addition is preferably performed in the presence of MeOH and at a temperature of from 35-55° C.
[0072] Preparation of Formula II:
[0073] Oxidation of VIII should provide II. The oxidation is performed by contacting VIII with an oxidant in the presence of a solvent and optionally a buffer.
[0074] One of ordinary skill in the art would recognize that oxidants such as KMnO 4 or NaClO 2 can be used. Preferably, KMnO 4 , in the presence of a buffer, is used as the oxidant. VIII can be suspended in an alcoholic solvent (e.g., t-butyl alcohol). The suspension is preferably maintained at a temperature of from 35-50° C. An aqueous solution of a buffer known to those of skill in the art (e.g., monobasic sodium phosphate monohydrate) can then be added. Preferably, the buffer is about 0.5 to 4N. Aqueous KMnO 4 can then be added to the reaction solution. After the reaction is complete, II can be isolated.
[0075] Preparation of Formula IVa:
[0076] IVa can be formed by coupling II and III. The coupling is preferably performed by contacting II with an acid activator, in a solvent and in the presence of a base, followed by contacting the resulting solution with III. An acid activator like thionyl chloride or oxalyl chloride can be used, with oxalyl chloride being a preferred activator. The addition of the acid activator is preferably performed at a temperature of from 10-30° C.
[0077] Contacting II and oxalyl chloride can be performed in a solvent selected from acetonitrile, THF, and methylene chloride, with acetonitrile being preferred. The first base can be selected from DMAP, triethylamine, diisopropylethylamine, N-methyl morpholine, and pyridine, with pyridine being preferred. The amount of first base present is preferably from 0.2 to 1 molar equivalent based on II, more preferably it is 0.4 molar equivalents.
[0078] The desired amount of oxalyl chloride to be added will be based on the amount of II present in the solution and the amount of water present in the solution. The amount of water present can be determined by known means, such as the Karl Fischer titration. Preferably, the number of moles of oxalyl chloride added is equal to or slightly greater than the sum of the number of moles of II and water present.
[0079] Once II has been activated, it can be contacted with III. Preferably, the reaction mixture is cooled to from 0-10° C. prior to contacting with III. After contacting III with the reaction mixture, a second base is preferably added. The second base can be selected from diisopropylethylamine, pyridine, DMAP, triethylamine, and N-methyl morpholine, with diisopropylethylamine being preferrred. The amount of second base present is preferably from about 1-3 molar equivalents, more preferably about 2.2 molar equivalents based on the amount of II present.
[0080] Preparation of Formula IV:
[0081] IV can be formed from IVa with or without purification of IVa. Preferably, IV is formed from IVa without purification. IVa is usually isolated as an oily substance. IVa is preferably taken up in a first solvent and maleic acid is added. To this solution can be added a second solvent to enhance or accelerate precipitation of IV. Preferably from 0.9 to 1.1 molar equivalents of maleic acid are present based on the amount of II present, more preferably about 0.95 molar equivalents. The first solvent can be selected from the group acetone, chloroform, ethyl acetate MIBK, i-propyl acetate, i-propyl alcohol, and THF, and is preferably ethyl acetate. The second solvent can be selected from the group 1-chlorobutane, heptane, hexane, methylene chloride, and TBME, and is preferably 1-chlorobutane. Preferably, this reaction is run at about room temperature.
[0082] Preparation of Formula V:
[0083] V can be prepared by contacting IV with HONHCOCH 3 in the presence of a base and a solvent. Preferably, the base is selected from K 2 CO 3 , Na 2 CO 3 , KHCO 3 , NaHCO 3 , KF, NaOH, and KOH, with K 2 CO 3 being a more preferred base. The solvent may be selected from DMSO, dimethylformamide (DMF), dimethylacetamide (DMAC), 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU), 1,3-dimethyl-2-imidazolidinone (DMI), and N-methylpyrrolidinone (NMP). A preferred solvent is DMF. It is preferred that the DMF comprises 0.5 to 50% by volume of water, more preferably, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, to 15% by volume of water, even more preferably 10, 11, 12, 13, 14, to 15% by volume of water, and still more preferably 15% by volume of water.
[0084] Preferably, HONHCOCH 3 , DMF, and K 2 CO 3 are mixed together followed by contacting with water. This reaction mixture is preferably kept at about 20-30° C. Upon contacting of the reaction mixture with IV, the reaction is preferably stirred at about room temperature.
[0085] Preparation of Formula I:
[0086] I can be formed from V by dissolving V in a solvent and contacting this solution with HCl. Preferably, the solvent is selected from methanol, acetonitrile, isopropyl alcohol, ethanol, propanol, acetone, methyl isobutyl ketone (MIBK), 2-butanone, and water, with ethanol being a more preferred solvent. V is preferably taken up in a solvent (e.g., ethanol) at a temperature of from 60-80° C. HCl is preferably contacted with the solution that is at a temperature of from 20-40° C. Preferably, the HCl is in an alcoholic solution. The alcoholic solution is preferably i-propyl alcohol.
[0087] I preferably precipitates from the reaction mixture. This precipitation can be enhanced by cooling the mixture to a temperature of about 0-10° C. Preferably I is a crystalline mono-HCl salt. More preferably, I is a solvate selected from ethanol, propanol, isopropanol, acetone, MIBK, 2-butanone, and water. Even more preferably, I is an ethanol solvate.
[0088] Other features of the invention will become apparent in the course of the following descriptions of exemplary embodiments that are given for illustration of the invention and are not intended to be limiting thereof.
EXAMPLES
Example 1
[0089] Preparation of VIII
[0090] To a 40 L Hastelloy “C” reactor fitted with an overhead air stirrer, thermocouple, condenser and nitrogen inlet, was charged conc. HCl (5.5 L). The reactor was cooled to between −5 and −10° C. VI (tan solid, 726 g, 5.3 mol) was added over 12 minutes while maintaining the internal temperature between −5 and −7° C. An additional 500 mL of conc. HCl was used to rinse down any VI hung up on the walls of the reactor. The resulting tan slurry was maintained at −5° C. over the next 10 minutes while a solution of sodium nitrite (450 g, 6.5 mol) in 3.1 L of purified water was prepared. The first 1500 mL of the sodium nitrite solution was added over 20 minutes wherein the internal temperature rose to 10° C. The addition was stopped for 30 minutes in order for the internal temperature to cool down and equilibrate to 2-3° C. The addition of sodium nitrite solution was resumed and the remaining 1.7 L was added over 30 minutes, while maintaining a temperature of 5-7° C. The batch was agitated for an additional 30 minutes at 6° C. Acetic acid (1.8 L) was added in one bolus with no appreciable change in the internal temperature (6° C). A solution of SnCl 2 .2H 2 O (2.8 kg, 12.2 mol) was prepared in 1.9 L H 2 O and 1.9 L of conc. HCl and added to the reaction over 55 minutes while maintaining the temperature between 6-10 ° C. The resulting white “milkshake-like” slurry was agitated for an additional 30 minutes.
[0091] Methanol (10 L) was charged as one bolus into the reactor and the reaction mixture was heated to 40° C. A solution of 4,4,4-trifluoro-2-furyl-1,3-butanedione (VII, 830 mL, 1.2 kg, 5.6 mol) in 3.1 L of MeOH was added over 35 minutes while maintaining an internal temperature between 41-43° C. After addition was complete, the batch was held between 45-50° C. for an additional 1.5 h whereupon the heat was shut off and the resulting orange slurry was allowed to cool to ambient temperature overnight (16 h) under a nitrogen atmosphere. The next morning, the batch was cooled further to help promote precipitation of VIII. The batch was cooled down to 0° C. and held for 1 hour at 0° C. before dropping the slurry onto a Dacron filter cloth in a 32 cm Buchner funnel. The filtration took 1 hour and the cake depth was determined to be 3.5 cm. The cake was rinsed with 3 L of cold (0-5° C.) 50/50 isopropanol/water followed by 2.9 L of water. The wet cake (3.4 kg) was dried to constant weight in a vacuum oven at 45° C. and 22 mm Hg over the weekend to produce 1.3 Kg of VIII as a yellow solid (1.3 Kg, 94.5 wt %, 71.7% corrected yield).
Example 2
[0092] Preparation of II
[0093] A 50 L Hastelloy C reactor, equipped with an overhead air stirrer, a thermocouple, an addition funnel, a condenser, and a nitrogen inlet was charged with melted t-butyl alcohol (10 L), followed by solid VIII (1160 g). An additional quantity of t-butyl alcohol (4.5 L) was used for purposes of rinsing the original containers and was added to the reactor. The suspension was warmed to between 38° C. and 45° C. until a homogeneous solution resulted. An aqueous solution of monobasic sodium phosphate monohydrate (1245 g in 5.2 L of purified water) was added to the mixture over approx. 15 min between 35° C. and 45° C. Celite® 545 (3.2 Kg) was added to the reactor between 38° C. and 45° C. and stirring was maintained to insure even dispersion of the solid. A commercial 40% aqueous solution of sodium permanganate (5.76 L) was added slowly over approx. 2.5 h, maintaining an internal temperature range between 42° C. and 50° C. The reaction mass was allowed to cool to ambient temperature and was held overnight with continuous stirring.
[0094] The next morning, the mixture was again heated to between 45° C. and 50° C. and t-butyl methyl ether (6.0 L) was added, followed by solid Celite® 545 (3.2 Kg) and neutral alumina (4.15 Kg). The mixture was stirred for approx. 15 min, filtered, and the cake was rinsed with t-butyl methyl ether (6 L total rinse volume). All filtrates obtained were recombined and the solvents were removed by distillation. When the distillation had ceased, purified water (5 L) was added, followed by a second distillation. The clear, homogeneous residue was diluted with water to give 18 L of total solution. n-Chlorobutane (8 L) was added, the biphasic mixture was slowly stirred for 15 min, and the upper layer was separated and discarded. The weakly basic aqueous layer was cooled to between 3° C. and 7° C. and 30% aqueous citric acid solution (3.3 L) was added, whereupon the crude II precipitated. The solids were collected by filtration and the cake was rinsed with purified water (5.0 L total rinse volume). Wet, yellow II was packed out and dried to constant weight in a vacuum oven at 70° C., affording dry II (815.1 g; 98.8 wt-%, 75% yield).
Example 3
[0095] Preparation of III
[0096] III can be prepared in accordance with the procedure described in co-pending U.S. Provisional Patent Application 60/220932, filed Jul. 26, 2000, the contents of which are hereby incorporated by reference. The following is an example of the preparation of III.
[0097] Dimethylamine in THF (7.2 L of 2.0 M solution, 14.3 mol) was charged into a 5 gallon Parr hydrogenator. 2-Formyl-imidazolyl (1.25 kg, 13.0 mol) and methanol (2.4 L) was charged next. After pressure testing the system with nitrogen, Pd/C (10%) (125 g, containing approximately 50% by weight water) was charged. Jacket cooling was set at 25° C. The batch was then pressurized with hydrogen and the pressure was maintained in the range 50-60 psig. The first 20 minutes of reaction saw a rise in the internal temperature to 35° C. and hydrogen uptake was extremely rapid. For the next 2 hours before the hydrogen pressure was released, the internal temperature was 30-31° C. HPLC analysis indicated that the conversion to 2-(N,N-dimethylaminomethyl)imidazole was complete (remaining 2-formyl-imidazolyl A %<2% versus 2-(N,N-dimethylaminomethyl)imidazole >98%). The batch was filtered through a 0.5 micron cartridge filter and then through a 0.45 micron minifilter to remove Pd/C. A solution of 1/1 v/v MeOH/THF (5 L) was used to wash out the reactor and line and was directed via the cartridge filters to the carboy containing the rest of the filtrate. The combined filtrates were concentrated via rotary evaporator to a 2.3 kg solution (contained 1.6 Kg of 2-(N,N-dimethylaminomethyl)imidazole), which was then used directly for next step.
[0098] To each of two 22 L five neck round bottom flasks equipped with over head air stirrer, thermocouple, and distillation set-up with nitrogen cap was charged a solution of crude 2-(N,N-dimethylaminomethyl)imidazole (4.86 kg of a solution made by the above procedure that contained 3.0 Kg of 2-(N,N-dimethylaminomethyl)imidazole). To each of the two reactors, anhydrous DMSO (10.0 L) was then introduced to give a dark amber clear solution. The residual MeOH and THF from the crude 2-(N,N-dimethylaminomethyl)imidazole in each of the two reactors was subsequently distilled off in vacuo at 50-60° C. before 1-amino-2-fluoro-4-iodobenzene (2.15 Kg, 9.05 mole) and powdered K 2 CO 3 (2.5 Kg, 18.1 mole, 2.0 equiv) were added to each of the two reactors at 40-50° C., respectively. Each of the two reactors was then degassed three times with a vacuum/nitrogen cycle ending on nitrogen before being charged with powdered CuI (260 g, 1.35 mole, 0.15 equiv). The resulting reaction mixture in each of the two reactors was degassed three times again with a vacuum/nitrogen cycle ending on nitrogen before being warmed to 125-130° C.
[0099] When the reaction was deemed complete after 16 h at 125-130° C. (1-amino-2-fluoro-4-iodobenzene<5% at 254 nm via HPLC analysis), the reaction mixture in each of the two reactors was cooled to 40-50° C. To each of the two reactors was added 4.0 L of saturated NH 4 Cl aqueous solution, and the resulting mixture was agitated for 1 h at 20-25° C. The mixture was then filtered through a Celite® bed, and each of the two reactors was washed with 1.0 L of saturated NH 4 Cl aqueous solution and 8.5 L of ethyl acetate. Half of the combined filtrates and washing solution were sequentially poured into a 40 L reactor, and the mixture was agitated at 20-25° C. for 0.5 h before the two layers were separated. The combined aqueous layers were poured back into the 40 L reactor and were extracted with ethyl acetate (4×15 L). During the process of the organic solvent extraction, emulsion colloid was resolved by filtration of the mixture through a Celite® bed before the two layers were separated. The combined organic extracts were then washed with 6.0 L of saturated NH 4 Cl aqueous solution, dried over MgSO 4 (2.0 Kg), and decolorized over active carbon (charcoal, 500 g) at 20-25° C. for 1 h in two separate 22 L reactors. The mixture was filtered through a Celite® bed, and each of the reactors was washed with ethyl acetate (2 L). The combined organic filtrates were then poured into a 40 L reactor, and a total of 68 L of ethyl acetate were successively distilled off in vacuo at 45-50° C. The residual slurry of the crude III in 9.0 L of ethyl acetate was subsequently transferred into a 22 L reactor, and the mixture was warmed to reflux (77-78° C.) to give a brown to black solution. Heptanes (6.0 L) were then added to the solution at 70° C., and the solution was cooled to 45-50° C. before being treated with active carbon (charcoal, 400 g). The mixture was warmed to reflux again for 1 h before being filtered through a Celite® bed at 50-55° C. The Celite® bed was washed with 2.0 L of ethyl acetate, and the combined filtrates and washing solution were poured back into a clean 22 L reactor. A total of 5.0 L of ethyl acetate was distilled off in vacuo at 45-50° C., and an additional 5.0 L of heptanes were added into the reactor at 50° C. The mixture was then gradually cooled to 20-25° C. and stirred at 20-25° C. for 1 h before being cooled to 5-10° C. for 2 h to precipitate III. The solids were collected by filtration on a 27 cm porcelain funnel lined with Dacron® cloth and washed with 20% (v/v) of TBME/heptanes (2×2.5 L). The solids were dried in vacuo with nitrogen purge at 40-45° C. to a constant weight. The first crop of III (1.749 Kg, 4.235 Kg theoretical, 41.3%) was obtained as pale-yellow crystals.
[0100] The combined mother liquor and washing solution was then concentrated in vacuo to afford the second crop of III (500 g, 4.235 kg theoretical, 11.8%; a total of 53.1% yield) as pale-yellow crystals.
Example 4
[0101] Preparation of IVa and IV
[0102] II (781 g, 2.61 mol) was combined with acetonitrile (11.3 L). The amount of water present in the solution was determined by performing a Karl Fischer titration. The volume of oxalyl chloride to be charged was calculated by adding the moles of II plus moles of water determined to be present to give moles of oxalyl chloride. Pyridine (81 mL, 1.0 mol) was charged followed by oxalyl chloride (227 mL, 2.60 mol). The reaction was warmed to 55-60° C. and held at that temperature for 1 hour. The progress of the reaction was followed by drawing a sample and quenching into NH 4 OH. Once the reaction was considered complete, a vacuum distillation was performed to remove 12% (v/v) of the solvent. Following the distillation fresh acetonitrile was added back to the reaction to replace the volume removed by the distillation.
[0103] The reaction mixture was chilled to 5° C. followed by the addition of III (598 g, 2.55 mol). An exotherm of 12° C. accompanied the addition. After allowing the solution to return to 5° C., diisopropylethylamine (975 mL, 5.60 mol) was added to the reaction over 60 minutes via addition funnel. Following the addition, the cooling bath was removed and the reaction was allowed to return to room temperature. Two hours following the addition of base the reaction was complete. The reaction was diluted with EtOAc (12 L) and washed with water (2×8 L). The aqueous washes were combined and back extracted with EtOAc (1×8 L). The organic fractions were combined and dried over MgSO 4 , filtered and concentrated to yield a brown oil, IVa.
[0104] The oil was reconstituted with EtOAc (11.3 L) and transferred to a 40 L kettle. Maleic acid (290 g, 2.50 mol) was added to the EtOAc solution that was then stirred at room temperature for 60 minutes. Approximately 15 minutes after the addition of maleic acid the resulting salt, IV, began to precipitate out of solution. 1-Chlorobutane (24 L) was added over 60-90 minutes to ensure complete precipitation. Following the addition of 1-chlorobutane, the IV solution was stirred at room temperature for 3 h. The salt was isolated by filtration and washed with 1-chlorobutane (6 L). The solids were dried in a 75° C. vacuum oven to constant weight to give 1.49 Kg (100.7 wt. %, 94.1% yield) of IV.
Example 5
[0105] Preparation of V
[0106] A 22 L reaction flask was charged with DMF (8 L), potassium carbonate (1576 g, 11.4 mol), and acetohydroxamic acid (428 g, 5.7 mol) and stirred at rt. Water (1.2 L, note: For Batch 1, 0.8 L of water was first added and an additional 0.4 L of water was added after stirring at rt for 27 h) was added slowly while keeping the reaction temperature at 20-30° C. After the reaction mixture was stirred for 30 min at 20-30° C., IV (1200 g, 1.9 mol) was added. The reaction mixture was stirred at rt for 4 to 20 h. This reaction mixture was quenched into 12 L of water in a 40 L reactor with vigorous agitation. The resulting slurry was stirred at rt for 2 h and then at 2-10° C. for another 1 h. The solid was filtered with a Dacron filter cloth. The cake was washed with cold water (8 L) and followed by cold acetonitrile (2 L) and dried in a vacuum oven to constant weight to give a crude product (1012 g). The crude product was dissolved in 12.5 L of acetonitrile at 65-80° C. After the solution was cooled to 25-37° C., water (2 L) was added over 2 h period while allowing the pot to cool to rt. The formed slurry was stirred at rt for 1 h. After cooling to 2-10° C., the solid was filtered with a Dacron filter cloth. The cake was washed with cold acetonitrile (4-6 L) and dried in a vacuum oven to constant weight to give the product V (92.3 g, 89%). HRMS for C 24 H 21 F 4 O 2 N 8 (M+H) + calcd 529.1724, found 529.1722. 1 H-NMR (300 MHz, DMSO-d 6 ) 2.09 (6H), 3.29 (2H), 6.54 (2H), 6.96 (1H), 7.41-7.75 (7H), 8.06 (1H) , 10.65 (1H). 19 F-NMR −119.632 (1F) , −61.257 (3F).
Example 6
[0107] Preparation of I
[0108] A 22 L reaction flask with overhead stirring, water condenser, and temperature probe was charged with ethanol (10 L) and V (monohydrate form, 850 g, 1.56 mol). The reaction mixture was heated to 65 to 80° C. to give a clear solution. After cooling to about 55° C., the warm solution was filtered through a cartridge filter. After transferring the filtrate back to the clean 22 L reactor and cooling the solution to 20-37° C., 4.6N HCl in IPA solution (355 mL, 1.63 mol) was charged through an addition funnel. After a slurry was formed, the mixture was stirred at rt for 1 h, and then at 2-8° C. for another 1 h. The solid was collected in a Buchner funnel with Dacron filter cloth. The cake was washed with cold ethanol (2 L) and followed by tert-butyl methyl ether (6 L), dried in a vacuum oven at 50° C. to give the product I (858 g, 98%). M.p. 258 C (dec). 1 H-NMR (300 MHz, DMSO-d 6 ) 1.02 (ethanol), 2.74 (6H), 3.40 (ethanol), 4.35 (2H), 6.59 (2H), 7.18 (1H), 7.34-7.80 (7H), 8.09 (1H), 10.99 (1H). 19 F-NMR −118.174 (1F), −61.229 (3F).
Example 7
[0109] Preparation of Va
[0110] To a solution of V (5.06 g) in chloroform (40 mL) and methanol (120 mL) was added 35% H 2 O 2 (20 mL) at rt. The reaction mixture was stirred at rt over 66 h. Water (180 mL) was then added to the reaction mixture and the resulting slurry was stirred at rt for 30 min. The solid was collected by filtration and dried in vacuo with nitrogen purge at rt to a constant weight (3.97 g).
UTILITY
[0111] The novel compounds of the present invention are useful as anticoagulants for the treatment or prevention of thromboembolic disorders in mammals. The term “thromboembolic disorders” as used herein includes arterial or venous cardiovascular or cerebrovascular thromboembolic disorders, including, for example, unstable angina, first or recurrent myocardial infarction, ischemic sudden death, transient ischemic attack, stroke, atherosclerosis, venous thrombosis, deep vein thrombosis, thrombophlebitis, arterial embolism, coronary and cerebral arterial thrombosis, cerebral embolism, kidney embolisms, and pulmonary embolisms. The anticoagulant effect of compounds of the present invention is believed to be due to inhibition of factor Xa or thrombin.
[0112] The effectiveness of compounds of the present invention as inhibitors of factor Xa was determined using purified human factor Xa and synthetic substrate. The rate of factor Xa hydrolysis of chromogenic substrate S2222 (Kabi Pharmacia, Franklin, Ohio) was measured both in the absence and presence of compounds of the present invention. Hydrolysis of the substrate resulted in the release of pNA, which was monitored spectrophotometrically by measuring the increase in absorbance at 405 nM. A decrease in the rate of absorbance change at 405 nm in the presence of inhibitor is indicative of enzyme inhibition. The results of this assay are expressed as inhibitory constant, K i .
[0113] Factor Xa determinations were made in 0.10 M sodium phosphate buffer, pH 7.5, containing 0.20 M NaCl, and 0.5% PEG 8000. The Michaelis constant, K m, for substrate hydrolysis was determined at 25° C. using the method of Lineweaver and Burk. Values of K i were determined by allowing 0.2-0.5 nM human factor Xa (Enzyme Research Laboratories, South Bend, Ind.) to react with the substrate (0.20 mM-1 mM) in the presence of inhibitor. Reactions were allowed to go for 30 minutes and the velocities (rate of absorbance change vs time) were measured in the time frame of 25-30 minutes. The following relationship was used to calculate K i values:
( v o −v s )/ v s =I /( K i (1 +S/K m ))
[0114] where:
[0115] v o is the velocity of the control in the absence of inhibitor;
[0116] v s is the velocity in the presence of inhibitor;
[0117] I is the concentration of inhibitor;
[0118] K i is the dissociation constant of the enzyme:inhibitor complex;
[0119] S is the concentration of substrate;
[0120] K m is the Michaelis constant.
[0121] Compounds tested in the above assay are considered to be active if they exhibit a K i of ≦10 μM. Preferred compounds of the present invention have K i 's of ≦1 μM. More preferred compounds of the present invention have K i 's of ≦0.1 μM. Even more preferred compounds of the present invention have K i 's of ≦0.01 μM. Still more preferred compounds of the present invention have K i 's of ≦0.001 μM. Using the methodology described above, a number of compounds of the present invention were found to exhibit a K i of ≦10 μM, thereby confirming the utility of the compounds of the present invention as effective Xa inhibitors.
[0122] The antithrombotic effect of compounds of the present invention can be demonstrated in a rabbit arterio-venous (AV) shunt thrombosis model. In this model, rabbits weighing 2-3 kg anesthetized with a mixture of xylazine (10 mg/kg i.m.) and ketamine (50 mg/kg i.m.) are used. A saline-filled AV shunt device is connected between the femoral arterial and the femoral venous cannulae. The AV shunt device consists of a piece of 6-cm tygon tubing which contains a piece of silk thread. Blood will flow from the femoral artery via the AV-shunt into the femoral vein. The exposure of flowing blood to a silk thread will induce the formation of a significant thrombus. After forty minutes, the shunt is disconnected and the silk thread covered with thrombus is weighed. Test agents or vehicle will be given (i.v., i.p., s.c., or orally) prior to the opening of the AV shunt. The percentage inhibition of thrombus formation is determined for each treatment group. The ID50 values (dose which produces 50% inhibition of thrombus formation) are estimated by linear regression.
[0123] The compounds of formula (I) may also be useful as inhibitors of serine proteases, notably human thrombin, plasma kallikrein and plasmin. Because of their inhibitory action, these compounds are indicated for use in the prevention or treatment of physiological reactions, blood coagulation and inflammation, catalyzed by the aforesaid class of enzymes. Specifically, the compounds have utility as drugs for the treatment of diseases arising from elevated thrombin activity such as myocardial infarction, and as reagents used as anticoagulants in the processing of blood to plasma for diagnostic and other commercial purposes.
[0124] Some compounds of the present invention were shown to be direct acting inhibitors of the serine protease thrombin by their ability to inhibit the cleavage of small molecule substrates by thrombin in a purified system. In vitro inhibition constants were determined by the method described by Kettner et al. in J. Biol. Chem. 265, 18289-18297 (1990), herein incorporated by reference. In these assays, thrombin-mediated hydrolysis of the chromogenic substrate S2238 (Helena Laboratories, Beaumont, Tex.) was monitored spectrophotometrically. Addition of an inhibitor to the assay mixture results in decreased absorbance and is indicative of thrombin inhibition. Human thrombin (Enzyme Research Laboratories, Inc., South Bend, Ind.) at a concentration of 0.2 nM in 0.10 M sodium phosphate buffer, pH 7.5, 0.20 M NaCl, and 0.5% PEG 6000, was incubated with various substrate concentrations ranging from 0.20 to 0.02 mM. After 25 to 30 minutes of incubation, thrombin activity was assayed by monitoring the rate of increase in absorbance at 405 nm which arises owing to substrate hydrolysis. Inhibition constants were derived from reciprocal plots of the reaction velocity as a function of substrate concentration using the standard method of Lineweaver and Burk. Using the methodology described above, some compounds of this invention were evaluated and found to exhibit a K i of less than 15 μm, thereby confirming the utility of the compounds of the present invention as effective Xa inhibitors.
[0125] The compounds of the present invention can be administered alone or in combination with one or more additional therapeutic agents. These include other anti-coagulant or coagulation inhibitory agents, anti-platelet or platelet inhibitory agents, thrombin inhibitors, or thrombolytic or fibrinolytic agents.
[0126] The compounds are administered to a mammal in a therapeutically effective amount. By “therapeutically effective amount” it is meant an amount of a compound of Formula I that, when administered alone or in combination with an additional therapeutic agent to a mammal, is effective to prevent or ameliorate the thromboembolic disease condition or the progression of the disease.
[0127] By “administered in combination” or “combination therapy” it is meant that the compound of Formula I and one or more additional therapeutic agents are administered concurrently to the mammal being treated. When administered in combination each component may be administered at the same time or sequentially in any order at different points in time. Thus, each component may be administered separately but sufficiently closely in time so as to provide the desired therapeutic effect. Other anticoagulant agents (or coagulation inhibitory agents) that may be used in combination with the compounds of this invention include warfarin and heparin, as well as other factor Xa inhibitors such as those described in the publications identified above under Background of the Invention.
[0128] The term anti-platelet agents (or platelet inhibitory agents), as used herein, denotes agents that inhibit platelet function such as by inhibiting the aggregation, adhesion or granular secretion of platelets. Such agents include, but are not limited to, the various known non-steroidal anti-inflammatory drugs (NSAIDS) such as aspirin, ibuprofen, naproxen, sulindac, indomethacin, mefenamate, droxicam, diclofenac, sulfinpyrazone, and piroxicam, including pharmaceutically acceptable salts or prodrugs thereof. Of the NSAIDS, aspirin (acetylsalicyclic acid or ASA), and piroxicam are preferred. Other suitable anti-platelet agents include ticlopidine, including pharmaceutically acceptable salts or prodrugs thereof. Ticlopidine is also a preferred compound since it is known to be gentle on the gastro-intestinal tract in use. Still other suitable platelet inhibitory agents include IIb/IIIa antagonists, thromboxane-A2-receptor antagonists and thromboxane-A2-synthetase inhibitors, as well as pharmaceutically acceptable salts or prodrugs thereof.
[0129] The term thrombin inhibitors (or anti-thrombin agents), as used herein, denotes inhibitors of the serine protease thrombin. By inhibiting thrombin, various thrombin-mediated processes, such as thrombin-mediated platelet activation (that is, for example, the aggregation of platelets, and/or the granular secretion of plasminogen activator inhibitor-1 and/or serotonin) and/or fibrin formation are disrupted. A number of thrombin inhibitors are known to one of skill in the art and these inhibitors are contemplated to be used in combination with the present compounds. Such inhibitors include, but are not limited to, boroarginine derivatives, boropeptides, heparins, hirudin and argatroban, including pharmaceutically acceptable salts and prodrugs thereof. Boroarginine derivatives and boropeptides include N-acetyl and peptide derivatives of boronic acid, such as C-terminal a-aminoboronic acid derivatives of lysine, ornithine, arginine, homoarginine and corresponding isothiouronium analogs thereof. The term hirudin, as used herein, includes suitable derivatives or analogs of hirudin, referred to herein as hirulogs, such as disulfatohirudin. Boropeptide thrombin inhibitors include compounds described in Kettner et al., U.S. Pat. No. 5,187,157 and European Patent Application Publication Number 293 881 A2, the disclosures of which are hereby incorporated herein by reference. Other suitable boroarginine derivatives and boropeptide thrombin inhibitors include those disclosed in PCT Application Publication Number 92/07869 and European Patent Application Publication Number 471,651 A2, the disclosures of which are hereby incorporated herein by reference.
[0130] The term thrombolytics (or fibrinolytic) agents (or thrombolytics or fibrinolytics), as used herein, denotes agents that lyse blood clots (thrombi). Such agents include tissue plasminogen activator, anistreplase, urokinase or streptokinase, including pharmaceutically acceptable salts or prodrugs thereof. The term anistreplase, as used herein, refers to anisoylated plasminogen streptokinase activator complex, as described, for example, in European Patent Application No. 028,489, the disclosure of which is hereby incorporated herein by reference herein. The term urokinase, as used herein, is intended to denote both dual and single chain urokinase, the latter also being referred to herein as prourokinase.
[0131] Administration of the compounds of Formula I of the invention in combination with such additional therapeutic agent, may afford an efficacy advantage over the compounds and agents alone, and may do so while permitting the use of lower doses of each. A lower dosage minimizes the potential of side effects, thereby providing an increased margin of safety.
[0132] The compounds of the present invention are also useful as standard or reference compounds, for example as a quality standard or control, in tests or assays involving the inhibition of factor Xa. Such compounds may be provided in a commercial kit, for example, for use in pharmaceutical research involving factor Xa. For example, a compound of the present invention could be used as a reference in an assay to compare its known activity to a compound with an unknown activity. This would ensure the experimenter that the assay was being performed properly and provide a basis for comparison, especially if the test compound was a derivative of the reference compound. When developing new assays or protocols, compounds according to the present invention could be used to test their effectiveness.
[0133] The compounds of the present invention may also be used in diagnostic assays involving factor Xa. For example, the presence of factor Xa in an unknown sample could be determined by addition of chromogenic substrate S2222 to a series of solutions containing test sample and optionally one of the compounds of the present invention. If production of pNA is observed in the solutions containing test sample, but no compound of the present invention, then one would conclude factor Xa was present.
[0134] Dosage and Formulation
[0135] The compounds of this invention can be administered in such oral dosage forms as tablets, capsules (each of which includes sustained release or timed release formulations), pills, powders, granules, elixirs, tinctures, suspensions, syrups, and emulsions. They may also be administered in intravenous (bolus or infusion), intraperitoneal, subcutaneous, or intramuscular form, all using dosage forms well known to those of ordinary skill in the pharmaceutical arts. They can be administered alone, but generally will be administered with a pharmaceutical carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice.
[0136] The dosage regimen for the compounds of the present invention will, of course, vary depending upon known factors, such as the pharmacodynamic characteristics of the particular agent and its mode and route of administration; the species, age, sex, health, medical condition, and weight of the recipient; the nature and extent of the symptoms; the kind of concurrent treatment; the frequency of treatment; the route of administration, the renal and hepatic function of the patient,and the effect desired. A physician or veterinarian can determine and prescribe the effective amount of the drug required to prevent, counter, or arrest the progress of the thromboembolic disorder.
[0137] By way of general guidance, the daily oral dosage of each active ingredient, when used for the indicated effects, will range between about 0.001 to 1000 mg/kg of body weight, preferably between about 0.01 to 100 mg/kg of body weight per day, and most preferably between about 1.0 to 20 mg/kg/day. Intravenously, the most preferred doses will range from about 1 to about 10 mg/kg/minute during a constant rate infusion. Compounds of this invention may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three, or four times daily.
[0138] Compounds of this invention can be administered in intranasal form via topical use of suitable intranasal vehicles, or via transdermal routes, using transdermal skin patches. When administered in the form of a transdermal delivery system, the dosage administration will, of course, be continuous rather than intermittent throughout the dosage regimen.
[0139] The compounds are typically administered in admixture with suitable pharmaceutical diluents, excipients, or carriers (collectively referred to herein as pharmaceutical carriers) suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixirs, syrups and the like, and consistent with conventional pharmaceutical practices.
[0140] For instance, for oral administration in the form of a tablet or capsule, the active drug component can be combined with an oral, non-toxic, pharmaceutically acceptable, inert carrier such as lactose, starch, sucrose, glucose, methyl callulose, magnesium stearate, dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like; for oral administration in liquid form, the oral drug components can be combined with any oral, non-toxic, pharmaceutically acceptable inert carrier such as ethanol, glycerol, water, and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents, and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth, or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes, and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride, and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum, and the like.
[0141] The compounds of the present invention can also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamellar vesicles, and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine, or phosphatidylcholines.
[0142] Compounds of the present invention may also be coupled with soluble polymers as targetable drug carriers. Such polymers can include polyvinylpyrrolidone, pyran copolymer, polyhydroxypropylmethacrylamide-phenol, polyhydroxyethylaspartamidephenol, or polyethyleneoxide-polylysine substituted with palmitoyl residues. Furthermore, the compounds of the present invention may be coupled to a class of biodegradable polymers useful in achieving controlled release of a drug, for example, polylactic acid, polyglycolic acid, copolymers of polylactic and polyglycolic acid, polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydropyrans, polycyanoacylates, and crosslinked or amphipathic block copolymers of hydrogels.
[0143] Dosage forms (pharmaceutical compositions) suitable for administration may contain from about 1 milligram to about 100 milligrams of active ingredient per dosage unit. In these pharmaceutical compositions the active ingredient will ordinarily be present in an amount of about 0.5-95% by weight based on the total weight of the composition.
[0144] Gelatin capsules may contain the active ingredient and powdered carriers, such as lactose, starch, cellulose derivatives, magnesium stearate, stearic acid, and the like. Similar diluents can be used to make compressed tablets. Both tablets and capsules can be manufactured as sustained release products to provide for continuous release of medication over a period of hours. Compressed tablets can be sugar coated or film coated to mask any unpleasant taste and protect the tablet from the atmosphere, or enteric coated for selective disintegration in the gastrointestinal tract.
[0145] Liquid dosage forms for oral administration can contain coloring and flavoring to increase patient acceptance.
[0146] In general, water, a suitable oil, saline, aqueous dextrose (glucose), and related sugar solutions and glycols such as propylene glycol or polyethylene glycols are suitable carriers for parenteral solutions. Solutions for parenteral administration preferably contain a water soluble salt of the active ingredient, suitable stabilizing agents, and if necessary, buffer substances. Antioxidizing agents such as sodium bisulfite, sodium sulfite, or ascorbic acid, either alone or combined, are suitable stabilizing agents. Also used are citric acid and its salts and sodium EDTA. In addition, parenteral solutions can contain preservatives, such as benzalkonium chloride, methyl- or propyl-paraben, and chlorobutanol.
[0147] Suitable pharmaceutical carriers are described in Remington's Pharmaceutical Sciences , Mack Publishing Company, a standard reference text in this field.
[0148] Representative useful pharmaceutical dosage-forms for administration of the compounds of this invention can be illustrated as follows:
[0149] Capsules
[0150] A large number of unit capsules can be prepared by filling standard two-piece hard gelatin capsules each with 100 milligrams of powdered active ingredient, 150 milligrams of lactose, 50 milligrams of cellulose, and 6 milligrams magnesium stearate.
[0151] Soft Gelatin Capsules
[0152] A mixture of active ingredient in a digestable oil such as soybean oil, cottonseed oil or olive oil may be prepared and injected by means of a positive displacement pump into gelatin to form soft gelatin capsules containing 100 milligrams of the active ingredient. The capsules should be washed and dried.
[0153] Tablets
[0154] Tablets may be prepared by conventional procedures so that the dosage unit is 100 milligrams of active ingredient, 0.2 milligrams of colloidal silicon dioxide, 5 milligrams of magnesium stearate, 275 milligrams of microcrystalline cellulose, 11 milligrams of starch and 98.8 milligrams of lactose. Appropriate coatings may be applied to increase palatability or delay absorption.
[0155] Injectable
[0156] A parenteral composition suitable for administration by injection may be prepared by stirring 1.5% by weight of active ingredient in 10% by volume propylene glycol and water. The solution should be made isotonic with sodium chloride and sterilized.
[0157] Suspension
[0158] An aqueous suspension can be prepared for oral administration so that each 5 mL contain 100 mg of finely divided active ingredient, 200 mg of sodium carboxymethyl cellulose, 5 mg of sodium benzoate, 1.0 g of sorbitol solution, U.S.P., and 0.025 mL of vanillin.
[0159] Where the compounds of this invention are combined with other anticoagulant agents, for example, a daily dosage may be about 0.1 to 100 milligrams of the compound of Formula I and about 1 to 7.5 milligrams of the second anticoagulant, per kilogram of patient body weight. For a tablet dosage form, the compounds of this invention generally may be present in an amount of about 5 to 10 milligrams per dosage unit, and the second anti-coagulant in an amount of about 1 to 5 milligrams per dosage unit.
[0160] Where the compounds of Formula I are administered in combination with an anti-platelet agent, by way of general guidance, typically a daily dosage may be about 0.01 to 25 milligrams of the compound of Formula I and about 50 to 150 milligrams of the anti-platelet agent, preferably about 0.1 to 1 milligrams of the compound of Formula I and about 1 to 3 milligrams of antiplatelet agents, per kilogram of patient body weight.
[0161] Where the compounds of Formula I are adminstered in combination with thrombolytic agent, typically a daily dosage may be about 0.1 to 1 milligrams of the compound of Formula I, per kilogram of patient body weight and, in the case of the thrombolytic agents, the usual dosage of the thrombolyic agent when administered alone may be reduced by about 70-80% when administered with a compound of Formula I.
[0162] Where two or more of the foregoing second therapeutic agents are administered with the compound of Formula I, generally the amount of each component in a typical daily dosage and typical dosage form may be reduced relative to the usual dosage of the agent when administered alone, in view of the additive or synergistic effect of the therapeutic agents when administered in combination.
[0163] Particularly when provided as a single dosage unit, the potential exists for a chemical interaction between the combined active ingredients. For this reason, when the compound of Formula I and a second therapeutic agent are combined in a single dosage unit they are formulated such that although the active ingredients are combined in a single dosage unit, the physical contact between the active ingredients is minimized (that is, reduced). For example, one active ingredient may be enteric coated. By enteric coating one of the active ingredients, it is possible not only to minimize the contact between the combined active ingredients, but also, it is possible to control the release of one of these components in the gastrointestinal tract such that one of these components is not released in the stomach but rather is released in the intestines. One of the active ingredients may also be coated with a material which effects a sustained-release throughout the gastrointestinal tract and also serves to minimize physical contact between the combined active ingredients. Furthermore, the sustained-released component can be additionally enteric coated such that the release of this component occurs only in the intestine. Still another approach would involve the formulation of a combination product in which the one component is coated with a sustained and/or enteric release polymer, and the other component is also coated with a polymer such as a low-viscosity grade of hydroxypropyl methylcellulose (HPMC) or other appropriate materials as known in the art, in order to further separate the active components. The polymer coating serves to form an additional barrier to interaction with the other component.
[0164] These as well as other ways of minimizing contact between the components of combination products of the present invention, whether administered in a single dosage form or administered in separate forms but at the same time by the same manner, will be readily apparent to those skilled in the art, once armed with the present disclosure.
[0165] 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.
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The present invention relates to the process for the preparation of the compound of Formula I:
from its corresponding 3-cyano-4-fluorophenyl-pyrazole and intermediates useful therein.
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[0001] This application claims priority to Chinese Patent Application Number 201110032500.X, which was filed Jan. 30, 2011, and which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to ventilation equipment, and in particular, to an energy recovery device for ventilation equipment.
BACKGROUND
[0003] As people are paying more attention to the air quality, there is a need for ventilation equipment that provides fresh air-flow. Such ventilation equipment often employs an energy recovery device to achieve the complete heat exchange between a fresh air-flow and an exhaust air-flow, thus fresh air-flow can be achieved while making use of the energy from the exhaust air-flow, so that a fresh air-flow of a higher quality can be provided to users.
[0004] For example, in International Publication No. WO2009090395, an energy recovery device is disclosed, which includes an exhaust air-flow inlet, an exhaust air-flow outlet in fluid communication with the exhaust air-flow inlet via a first duct, a fresh air-flow inlet, and a fresh air-flow outlet in fluid communication with the fresh air-flow inlet via a second duct. However, this international patent application does not disclose the specific construction of the energy recovery device.
[0005] An energy recovery device in the prior art has a feature that by means of a “X” configuration or a “S” configuration, the direction of fresh air-flow and the direction of exhaust air-flow are crossed. The energy recovery device with such a configuration increases the height or length of the ventilation equipment, thus increasing the costs of the ventilation equipment. At the same time, this energy recovery device in the prior art only provides slots and projections for sealing at its inlet side/outlet side, which increases the risk of mixing the fresh air-flow with the exhaust air-flow, and reduces the quality of fresh air-flow. Furthermore, the counter-flow energy exchanging portion of the energy recovery device in the prior art is provided with ducts, which are parallel to one another and equal in length and in distance therebetween, so as to form laminar flow and to enable the pressure drop in each of the ducts to remain balanced without the need to consider the differences in inlet angles, outlet angles, pressures and speeds, but this reduces the efficiency of the energy exchange.
SUMMARY
[0006] An object of the present invention is to provide a novel energy recovery device with low costs, high efficiency to address the disadvantages in the prior art.
[0007] In an illustrative embodiment, an energy recovery device is provided that may include at least two frames which are adjacently arranged, wherein said at least two frames comprise fresh air-flow and exhaust air-flow frames, wherein the fresh air-flow frame comprises fresh air-flow frame rods and a plurality of fresh air-flow ducts arranged therein, with each fresh air-flow duct has a fresh air-flow duct inlet, a fresh air-flow duct outlet, and a bend section of the fresh air-flow duct for connecting them; the exhaust air-flow frame may include exhaust air-flow frame rods and a plurality of exhaust air-flow ducts arranged therein, with each exhaust air-flow duct having an exhaust air-flow inlet, an exhaust air-flow outlet, and a bend section of the exhaust air-flow duct for connecting them. The plurality of fresh air-flow ducts and the plurality of exhaust air-flow ducts may be in a mirror image arrangement such that the fresh air-flow duct inlets and exhaust air-flow duct outlets are located generally on the same side, and the fresh air-flow duct outlets and the exhaust air-flow duct inlets are located generally on the same side, so that the exhaust air-flow in the space to be ventilated is discharged into the atmosphere from the exhaust air-flow duct outlet after entering the exhaust air-flow duct inlet and passing through the bend section of the exhaust air-flow duct, and the fresh air-flow from the atmosphere enters into the space to be ventilated through the bend section of the fresh air-flow duct after entering the fresh air-flow duct inlet. The fresh air-flow and the exhaust air-flow may have energy exchange via the fresh air-flow ducts and the exhaust air-flow ducts.
[0008] An energy recovery device may be provided, wherein the fresh air-flow frame and the exhaust air-flow frame are hexagons in shape; the fresh air-flow frame comprises a first fresh air-flow frame rod, a second fresh air-flow frame rod, a third fresh air-flow frame rod, a fourth fresh air-flow frame rod, a fifth fresh air-flow frame rod and a sixth fresh air-flow frame; and the exhaust air-flow frame comprises a first exhaust air-flow frame rod, a second exhaust air-flow frame rod, a third exhaust air-flow frame rod, a fourth exhaust air-flow frame rod, a fifth exhaust air-flow frame rod and a sixth exhaust air-flow frame rod; wherein the fresh air-flow duct inlets of the plurality of fresh air-flow ducts are provided on the fifth fresh air-flow frame rod of the fresh air-flow frame, the fresh air-flow duct outlets of the plurality of fresh air-flow ducts are provided on the first fresh air-flow frame rod of the fresh air-flow frame, the exhaust air-flow duct inlets of the plurality of exhaust air-flow ducts are provided on the second exhaust air-flow frame rod of the exhaust air-flow frame, and the exhaust air-flow duct outlets of the plurality of exhaust air-flow ducts are provided on the fourth exhaust air-flow frame rod of the exhaust air-flow frame, so that the flowing direction of the fresh air-flow in the fresh air-flow ducts is opposite to the flowing direction of the exhaust air-flow in the exhaust air-flow ducts.
[0009] An energy recovery device may be provided, wherein each of the plurality of fresh air-flow ducts and each of the plurality of exhaust air-flow ducts are “C-shaped” or “L-shaped”.
[0010] An energy recovery device may be provided, wherein each of the plurality of fresh air-flow ducts has unequal lengths, and they are spaced from one another unequally.
[0011] An energy recovery device may be provided, wherein each of the plurality of exhaust air-flow ducts has unequal lengths, and they are spaced from one another unequally.
[0012] An energy recovery device may be provided, wherein the plurality of fresh air-flow ducts have different inlets and outlets, respectively.
[0013] An energy recovery device may be provided, wherein the plurality of exhaust air-flow ducts have different inlets and outlets, respectively.
[0014] An energy recovery device may be provided, wherein the energy recovery device further comprises a medium with heat transmissibility and moisture permeability, which is arranged between the at least two frames.
[0015] An energy recovery device may be provided, wherein the medium with heat transmissibility and moisture permeability arranged between the at least two frames is a membrane and/or paper.
[0016] An energy recovery device may be provided, wherein a cover lid is used for installing said at least two frames.
[0017] An energy recovery device may be provided, wherein the fresh air-flow frame, the exhaust air-flow frame, the fresh air-flow ducts and the exhaust air-flow ducts are all made of acrylonitrile-butadiene-styrene.
[0018] Another illustrative embodiment may include ventilation equipment, wherein said ventilation equipment includes a housing and an above-mentioned energy recovery device provided therein, with said housing includes a fresh air-flow inlet, a fresh air-flow outlet, an exhaust air-flow inlet and an exhaust air-flow outlet, and wherein the fresh air-flow duct inlets of the energy recovery device are in fluid communication with the fresh air-flow inlet of said housing, the fresh air-flow duct outlets of the energy recovery device are in fluid communication with the fresh air-flow outlet of said housing, the exhaust air-flow duct inlets of the energy recovery device are in fluid communication with the exhaust air-flow inlet of said housing, and the exhaust air-flow duct outlets of the energy recovery device are in fluid communication with the exhaust air-flow outlet of said housing.
[0019] Some embodiments may have one or more of the following advantages: when the fresh air-flow ducts and exhaust air-flow ducts employ a “C-shaped” configuration or a “L-shaped” configuration, the inlets and outlets can be located at the same side, allowing either side of the ventilation equipment to have a bypass function, thus increasing the area for total heat exchanging at every level, and improving a good energy exchange efficiency.
[0020] Some embodiments may have one or more of the following advantages: the fresh air-flow ducts and the exhaust air-flow ducts may include inlets, outlets and “C-shaped” or “L-shaped” bend sections, wherein the “C-shaped” or “L-shaped” bend sections are used for counter-flow heat exchanging, thus making it possible for the six frame rods of the fresh air-flow frame and the exhaust air-flow frame to be sealed properly without relative movements therebetween.
[0021] Some embodiments may have one or more of the following advantages: the fresh air-flow ducts and the exhaust air-flow ducts may employ parallel bent portions, unequal angles and lengths, and unequal inlets and outlets, thus enabling the energy exchange to be realized by way of turbulent flows, so as to increase the efficiency of energy exchange.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] With reference to the accompanying drawings, the disclosure of the present invention will become readily understandable. It is easy for those skilled in the art to understand that these accompanying drawings are intended only for purpose of illustration, and are not intended to limit the protective scope of the present invention, in which:
[0023] FIG. 1 shows a perspective view of the ventilation equipment with an energy recovery device according to one embodiment of the present invention;
[0024] FIG. 2 shows a perspective view of an energy recovery device according to one embodiment of the present invention;
[0025] FIG. 3 shows a view of one of the frames having a plurality of ducts, for forming the energy recovery device of FIG. 2 ;
[0026] FIG. 4 shows a view of another frame having a plurality of ducts, for forming the energy recovery device of FIG. 2 ; and
[0027] FIG. 5 shows a layout diagram of at least two frames having a plurality of ducts, for forming the energy recovery device of FIG. 2 .
DESCRIPTION
[0028] The particular embodiments of the present invention are illustrated in FIGS. 1-5 and the following description to teach those skilled in the art how to implement and reproduce the best mode of the present invention. For the sake of teaching the inventive principles, some conventional aspects are simplified or omitted. It should be understood by those skilled in the art that the variants derived from these embodiments will fall into the protective scope of the present invention. It should be also understood by those skilled in the art that the features mentioned below can be combined in various ways to form a plurality of variants of the present invention. Accordingly, the present invention is not limited by the specific embodiments described below, instead it is defined only by the terms of the claims and the equivalents thereof.
[0029] FIG. 1 shows a perspective view of the ventilation equipment comprising an energy recovery apparatus in an embodiment according to the present invention. As shown in FIG. 1 , the ventilation equipment comprises a housing, a fresh air-flow outlet 1 , a fresh air-flow inlet 3 , an exhaust air-flow inlet 5 , an exhaust air-flow outlet 7 , an energy recovery device 9 arranged in the housing; a first separation wall 14 a , a second separation wall 14 b , a third separation wall 14 c , a fourth separation wall 14 d and a fifth separation wall 14 e , each of these separation walls is arranged in the housing. In this case, the housing comprises the first side wall 13 a , the second side wall 13 b , the third side wall 13 c , and the fourth side wall 13 d , wherein each of these side walls is arranged next to one another in succession. Among them, the fresh air-flow outlet 1 and the exhaust air-flow outlet 5 are arranged on the first side wall 13 a , and the fresh air-flow inlet 3 and exhaust air-flow outlet 7 are arranged on the third side wall 13 c . The energy recovery device 9 comprises at least two frames, in which one frame is referred to as the fresh air-flow frame 15 , and the other frame is referred to as the exhaust air-flow frame 17 . A medium with good heat conductivity and moisture permeability (not shown) is disposed between the fresh air-flow frame 15 and the exhaust air-flow frame 17 . FIG. 2 shows a perspective view of an energy recovery apparatus in an embodiment according to the present invention. FIG. 3 shows a view of one of the frames with a plurality of ducts, for forming the energy recovery device in FIG. 2 . As shown in FIGS. 2 and 3 , the energy recovery device 9 comprises at least one normal hexagonal shaped fresh air-flow frame 15 , which comprises a first fresh air-flow frame rod 15 a , a second fresh air-flow frame rod 15 b , a third fresh air-flow frame rod 15 c , a fourth fresh air-flow frame rod 15 d , a fifth fresh air-flow frame rod 15 e , and a sixth fresh air-flow frame rod 15 f . The fresh air-flow frame 15 also comprises a plurality of “C-shaped” fresh air-flow ducts 16 which are arranged therein, with each of the fresh air-flow ducts 16 comprising a fresh air-flow duct inlet 16 a and a fresh air-flow duct outlet 16 b . In which a plurality of fresh air-flow duct inlets 16 a are arranged on the fifth fresh air-flow frame rod 15 e , and a plurality of fresh air-flow duct outlets 16 b are arranged on the first fresh air-flow frame rod 15 a . FIG. 5 shows a layout diagram of at least two frames with a plurality of ducts, for forming the energy recovery device in FIG. 2 . As shown in FIG. 5 , the energy recovery device 9 further comprises at least one normal hexagonal shaped exhaust air-flow frame 17 , and FIG. 4 shows a view of the other one of the frames with a plurality of ducts for forming the energy recovery device in FIG. 2 . As shown in FIG. 4 , the exhaust air-flow frame 17 comprises the first exhaust air-flow frame rod 17 a , the second exhaust air-flow frame rod 17 b , the third exhaust air-flow frame rod 17 c , the fourth exhaust air-flow frame rod 17 d , the fifth exhaust air-flow frame rod 17 e , and the sixth exhaust air-flow frame rod 17 f , wherein each of these exhaust air-flow frame rods is arranged next to one another in succession. The exhaust air-flow frame 17 also comprises a plurality of “C-shaped” exhaust air-flow ducts 18 which are arranged therein, with each of the exhaust air-flow ducts 18 comprising an exhaust air-flow duct inlet 18 a and an exhaust air-flow duct outlet 18 b . A plurality of exhaust air-flow duct inlets 18 a are arranged on the second exhaust air-flow frame rod 17 b of the exhaust air-flow duct 18 , and a plurality of exhaust air-flow duct outlet 18 b are arranged on the fourth exhaust air-flow frame rod 17 d . FIG. 5 shows a layout diagram of the at least two frames with a plurality of ducts, for forming the energy recovery device in FIG. 2 . It can be seen from FIG. 5 that the plurality of “C-shaped” exhaust air-flow ducts 18 arranged on the exhaust air-flow frame 17 and the plurality of “C-shaped” fresh air-flow ducts 16 arranged on the fresh air-flow frame 15 are in a mirror image arrangement. As shown in FIG. 1 , the third separation wall 14 c , the fourth separation wall 14 d , the fifth separation wall 14 e , the third side wall 13 c , the fourth side wall 13 d and the fresh air-flow inlet side of the energy recovery device 9 form a fresh air-flow inlet area. The first separation wall 14 a , the fourth separation wall 14 d , the first side wall 13 a , the fourth side wall 13 d and the fresh air-flow outlet side of the energy recovery device 9 form a fresh air-flow outlet area, in which an air blower 11 is arranged in the fresh air-flow outlet area. The first separation wall 14 a , the second separation wall 14 b , the first side wall 13 a , the second side wall 13 b and the exhaust air-flow inlet side of the energy recovery device 9 form an exhaust air-flow inlet area. The second separation wall 14 b , the third separation wall 14 c , the second side wall 13 b , the third side wall 13 c and the fresh air-flow outlet side of the energy recovery device 9 form an exhaust air-flow outlet area, in which another air blower 11 is arranged in the exhaust air-flow outlet area.
[0030] When the ventilation equipment shown in FIG. 1 is in operation, on the one hand, the exhaust air-flow in the ventilation space enters into the exhaust air-flow inlet area under the effects of the air blower 11 arranged in the exhaust air-flow outlet area, then it enters the “C-shaped” exhaust air-flow ducts 18 via the plurality of exhaust air-flow duct inlets 18 a arranged on the exhaust air-flow inlet side of the energy recovery device 9 , subsequently, it enters from the exhaust air-flow duct outlets 18 b of the “C-shaped” exhaust air-flow ducts 18 into the exhaust air-flow outlet area, and finally, it is exhausted into the atmosphere via the exhaust air-flow outlet 7 . On the other hand, the fresh air-flow in the atmosphere is drawn into the fresh air-flow inlet area under the effects of the air blower 11 arranged in the fresh air outlet area, then it enters into the “C-shaped” fresh air-flow ducts 16 via the plurality of fresh air-flow duct inlets 16 a arranged in the fresh air-flow inlet side of the energy recovery device 9 , subsequently, it enters from the fresh air-flow duct outlets 16 b of the “C-shaped” fresh air-flow ducts 16 into the fresh air-flow inlet area, and finally it enters into the space to be ventilated via the fresh air-flow outlet 1 . Since the fresh air-flow ducts 16 and the exhaust air-flow ducts 18 are arranged next to one another in the energy recovery device 9 in a mirror image arrangement, this allows the fresh air-flow which has passed through the “C-shaped” fresh air-flow ducts 16 and the exhaust air-flow which has passed through the “C-shaped” exhaust air-flow ducts 18 , to have heat exchange in the energy recovery device 9 via a medium with heat conductivity and moisture permeability characteristics arranged between the fresh air-flow frame 15 and the exhaust air-flow frame 17 , —so as to enable the fresh air-flow which has had heat exchange with the exhaust air-flow to be pumped into the space to be ventilated.
[0031] In an embodiment of the present invention, the fresh air-flow frame 15 , the exhaust air-flow frame 17 , the plurality of fresh air-flow ducts 16 and the plurality of exhaust air-flow ducts 18 are preferably made of acrylonitrile-butadiene-styrene. It needs to be mentioned that the fresh air-flow frame 15 , the exhaust air-flow frame 17 , the plurality of fresh air-flow ducts 16 and the plurality of exhaust air-flow ducts 18 can also be made of other materials, and this would still fall into the scope of the present invention.
[0032] In an embodiment of the present invention, the medium with good heat conductivity and moisture permeability characteristics arranged between the fresh air-flow frame 15 and the exhaust air-flow frame 17 is a membrane or a piece of special paper. For those skilled in the art, the membrane and the special paper are the membrane and paper commonly used in the art, therefore they do not need to be described redundantly herein.
[0033] In one embodiment of the present invention, the fresh air-flow duct 16 and the exhaust air-flow duct 18 can also adopt an L-shaped configuration. As can be seen in FIGS. 3 and 4 , the plurality of fresh air-flow ducts 16 and exhaust air-flow ducts 18 respectively have bend sections, different inlets and outlets, different lengths and different spacing. The “C-shaped” or “L-shaped” configuration is applied in the fresh air-flow ducts 16 and exhaust air-flow ducts 18 in the ventilation equipment according to the present invention, which can allow the inlets and outlets to be placed on the same side, enabling any side of the ventilation equipment to have a bypass function, thus increasing the total heat exchange area per layer, and improving the energy exchange efficiency.
[0034] In an embodiment of the present invention, the fresh air-flow ducts 16 and the exhaust air-flow ducts 18 comprise inlets, outlets, and “C-shaped” or “L-shaped” bend sections, in which the “C-shaped” or “L-shaped” bend sections are used for counter-flow heat exchanging, and this allows all of the six frame rods of the fresh air-flow frame 15 and the exhaust air-flow frame 17 to be sealed properly without any movement relative to one another.
[0035] In an embodiment of the present invention, the parallel bend sections (such as “C-shaped” or “L-shaped” bend sections), unequal angles and lengths, and unequal inlets and outlets are adopted in the fresh air-flow ducts 16 and the exhaust air-flow ducts 18 , enabling the energy exchange to be performed by turbulent flows, thus improving the energy exchange efficiency.
[0000]
List of names of the components and reference numerals thereof
1
fresh air-flow outlet
3
fresh air-flow inlet
5
exhaust air-flow inlet
7
exhaust air-flow outlet
9
energy recovery device
11
air blower
13a
first side wall
13b
second side wall
13c
third side wall
13d
fourth side wall
14a
first separation wall
14b
second separation wall
14c
third separation wall
14d
fourth separation wall
14e
fifth separation wall
15
fresh air-flow frame
15a
first fresh air-flow frame rod
15b
second fresh air-flow frame rod
15c
third fresh air-flow frame rod
15d
fourth fresh air-flow frame rod
15e
fifth fresh air-flow frame rod
15f
sixth fresh air-flow frame rod
16
fresh air-flow duct
16a
fresh air-flow duct inlet
16b
fresh air-flow duct outlet
17
exhaust air-flow frame
17a
first exhaust air-flow frame rod
17b
second exhaust air-flow frame rod
17c
third exhaust air-flow frame rod
17d
fourth exhaust air-flow frame rod
17e
fifth exhaust air-flow frame rod
17f
sixth exhaust air-flow frame rod
18
exhaust air-flow duct
18a
exhaust air-flow duct inlet
18b
exhaust air-flow duct outlet
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An energy recovery device includes a first fluid path extending between a fresh air inlet and a fresh air outlet, and a second fluid path extending between an exhaust inlet and an exhaust air outlet. The first fluid path and the second fluid path may direct flow in a direction that is substantially parallel to one another through at least part of the energy recovery device. In some cases, a bend may be provided in at least part of the energy recovery device such that the first fluid path directs flow in a direction that is at a first angle relative to fluid flow through the second fluid path for a first portion of the first fluid path, and in a direction that is at a second angle relative to fluid flow through the second fluid path for a second portion of the first fluid path.
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TECHNICAL FIELD
[0001] The invention relates to a floating disc brake, a method of assembling the same and an assembly of a pad clip and a return spring capable of smoothly returning a pad upon braking release to thus prevent friction between a lining of the pad and a side surface of a rotor upon non-braking, efficiently reducing a drag of the rotor upon non-braking and wear of the lining, improving assembling performance and reducing assembling cost.
BACKGROUND ART
[0002] Regarding a disc brake for braking a vehicle such as automobile, a floating disc brake has been widely known and has been actually used which supports a caliper so that it can displace in an axial direction (in the specification and the claims, an ‘axial direction’, a ‘diametrical direction’ and a ‘circumferential direction’ means an ‘axial direction’, a ‘diametrical direction’ and a ‘circumferential direction’ of a rotor, respectively) with respect to a support.
[0003] FIG. 57 shows a floating disc brake, which is a first example of the prior art disclosed in PTL1. The floating disc brake displaces a caliper 2 with respect to a rotor 1 rotating together with a wheel (not shown), upon braking. At a state where the brake is mounted to a vehicle, a support 3 that is provided in the vicinity of one side of the rotor 1 in an axial direction is fixed to a vehicle body (not shown). Also, the caliper 2 is supported to the support 3 so as to be axially displaceable.
[0004] Therefore, a pair of guide pins 4 that is provided at both end portions of the caliper 2 in a circumferential direction and a pair of guide holes 5 that is provided at both end portions of the support 3 in a circumferential direction are provided in parallel with a central axis of the rotor 1 , respectively. The guide pins 4 are axially slidably inserted into the guide holes 5 . Boots 6 , 6 , for dust-proof are provided between outer peripheries of base end portions of the guide pins 4 and openings of the guide holes 5 .
[0005] Also, at both end portions of the support 3 , rotation input side and rotation output side engaging sections 7 , 8 are respectively provided at parts spaced from the rotor 1 in the circumferential direction. Both circumferential end portions of pressure plates 10 a, 10 b configuring pads 9 a, 9 b are engaged with the engaging sections 7 , 8 . Also, the caliper 2 having a cylinder section 11 and a claw section 12 is arranged so that it extends over the both the pads 9 a, 9 b. Also, the cylinder section 11 is fluid-tightly fitted with a piston 13 that presses the inner (upper side in FIG. 57 at a widthwise inner side of the vehicle) pad 9 a to the rotor 1 .
[0006] When braking the vehicle, a pressure oil is supplied into the cylinder section 11 , so that a lining 14 a of the inner pad 9 a is pressed to an inner surface of the rotor 1 from the upper to the lower in FIG. 57 by the piston 13 . Thus, as a reaction to the pressing force, the caliper 2 is displaced upward in FIG. 57 , based on the sliding between the guide pins 4 and the guide holes 5 , and the claw section 12 presses a lining 14 b of the outer (lower side in FIG. 57 at a widthwise outer side of the vehicle) pad 9 b to an outer surface of the rotor 1 . As a result, the rotor 1 is strongly held from both inner and outer side surfaces, so that the braking is made.
[0007] Upon the non-braking of the disc brake configured and operating as described above, when the linings 14 a, 14 b of the respective pads 9 a, 9 b and the inner and outer side surfaces of the rotor 1 rub each other, drag torque (rotation resistance) of the rotor 1 is increased, so that the gas mileage performance is lowered and the linings 14 a, 14 b are unnecessarily worn. The unnecessary wear of the linings 14 a , 14 b lowers a mileage until the respective pads 9 a, 9 b are replaced, so that the driving cost is increased.
[0008] In order to solve the above problem, for example, PTLs 2 to 4 disclose a structure where a return spring is provided between the inner and outer pads and friction surfaces of the linings of the pads are separated from both side surfaces of the rotor as the braking is released. FIG. 58 shows a second example of the prior art disclosed in PTL2.
[0009] In the second example, between the support 3 and the pads 9 a, 9 b, a pad clip 15 for preventing the pads 9 a, 9 b from rattling is provided and a return spring 16 for applying an elastic urging force (returning force) to the pads 9 a, 9 b in a direction getting away from each other is provided. The return spring 16 has a substantial M shape that is a whole shape, and has a coil section 17 at a central portion thereof in an axial direction. Both end portions of the return spring 16 are engaged into engaging holes 18 , 18 that are formed on outer peripheral edges of circumferential end portions of the pressure plates 10 a, 10 b, and the coil section 17 is engaged to a protruding pin 19 extending from an upper end edge of the pad clip 15 . By the configuration as described above, the elastic urging force is applied to the pads 9 a, 9 b in the direction getting away from each other. Hence, upon the braking release, friction surfaces of the linings 14 a, 14 b of the pads 9 a, 9 b are separated from both side surfaces of the rotor 1 .
[0010] In the second example of the prior art, upon the non-braking, it is possible to prevent the friction between the linings 14 a, 14 b of the pads 9 a, 9 b and the side surfaces of the rotor. However, the assembling operation is troublesome and the assembling cost is thus increased. That is, in the second example, it is not possible to support the return spring 16 to the pad clip 15 with sufficient support force. Hence, when mounting the pad clip 15 , it is not possible to handle the pad clip 15 and the return spring 16 as an integral article, so that it is necessary to separately perform the mounting operations. Also, just after mounting the return spring 16 , the elastic urging force is applied to the pads 9 a, 9 b in the direction getting away from each other. Hence, it is necessary to configure the pads 9 a, 9 b so that they are not separated and deviated from the support 3 in the axial direction. Also, even when separating the caliper upon the replace of the pads 9 a, 9 b, since the elastic urging force of the return spring 16 is being applied to the respective pads 9 a, 9 b, it is necessary to configure the respective pads 9 a, 9 b so that they are not separated. Such assembling operation or replacing operation is troublesome, so that the assembling cost is increased.
[0011] Also, in the second example, both end portions of the return spring 16 are engaged to the outer peripheral edges of the respective pads 9 a, 9 b. Hence, at a state where the braking is released, the pads 9 a, 9 b are more apt to be inclined in a direction coming close to the rotor at the inner diameter sides (inner peripheral edges). Therefore, the side surfaces of the rotor and the inner peripheral edges of the linings 14 a, 14 b of the pads 9 a, 9 b easily rub each other.
[0012] Also, the magnitudes of the elastic urging force applied to the pads 9 a, 9 b by the return spring 16 are the same. Therefore, an amount of wear of the lining 14 b of the outer pad 9 b of the pads 9 a, 9 b may be larger than that of the lining 14 a of the inner pad 9 a. That is, upon the braking release, the supply of the pressure oil into the cylinder section is stopped, so that the force of pressing the inner pad 9 a toward the rotor is lost. Therefore, the inner pad 9 a can be relatively easily displaced in a direction getting away from the inner side surface of the rotor. Compared to this, while the outer pad 9 b is displaced in a direction getting away from the outer side surface of the rotor, the friction (for example, sliding friction to be applied between the guide pin and the guide hole) that is applied to the sliding section of the caliper acts as resistance. Accordingly, the outer pad 9 b is difficult to be displaced in a direction getting away from the outer side surface of the rotor. As a result, as described above, an amount of wear of the lining 14 b of the outer pad 9 b may be larger than that of the lining 14 a of the inner pad 9 a. Also, a thickness of the rotor may be varied due to the wear, which causes judder.
[0013] PTLs 2 to 4 do not describe or suggest a configuration for solving the above problems.
[0014] Also, as shown in FIG. 59 , PTL5 discloses a structure where a return spring 56 , which is formed by bending a wire rod and has a pair of coil sections 55 , 55 at a central portion thereof, is engaged to an anti-rattle spring 57 . In the structure disclosed in PTL5, each of the coil sections 55 , 55 is provided so that a direction of a central axis and a diametrical direction are substantially matched. Therefore, as the coil sections 55 , 55 are put on, a size of the support 3 in a circumferential direction is increased, so that it is difficult to secure a gap between the support 3 and an inner periphery of a wheel (not shown), regarding a layout. Also, outer end portions of the pads 9 a, 9 b in the diametrical direction are pressed by pressing sections (engaging sections) 58 , 58 provided to the return spring 56 . Thereby, as the braking is released, the diametrically outer sides are widened each other, i.e., the pads 9 a, 9 b are easily fallen. Even when it is intended to press the diametrically central portions of the respective pads 9 a, 9 b, a length (whole length) from each of the coil sections 55 , 55 to each of the pressing sections 58 , 58 is lengthened and the coil sections 55 , 55 and the pressing sections 58 , 58 are largely deviated in the diametrical direction (a diametrical length is increased). Hence, it is not possible to effectively use the elastic deformation of the coil sections 55 , 55 as the returning force of separating the pads 9 a , 9 b from the rotor. Also, in the structure disclosed in PTL5, after the anti-rattle spring 57 is mounted to the support 3 and the respective pads 9 a, 9 b are then mounted thereto, the return spring 56 is simply mounted. That is, PTL5 does not consider at all that the return spring 56 is mounted to the anti-rattle spring 57 before the respective pads 9 a, 9 b are mounted and that the anti-rattle spring 57 and the return spring 56 are handled as an integral article (assembly).
CITATION LIST
Patent Literatures
[0015] [PTL1] JP-Y-61-21619
[0016] [PTL2] JP-A-5-36141
[0017] [PTL3] JP-U-5-14679
[0018] [PTL4] JP-U-2-92130
[0019] [PTL5] JP-A-56-127830
SUMMARY OF INVENTION
Technical Problem
[0020] The invention has been made to solve the above problems. The invention implements a structure where when mounting a pad clip, it is possible to handle the pad clip and a return spring as an integral article (subassembly), thereby facilitating a mounting operation. Also, the invention implements a structure where it is possible to effectively use elastic deformation of a coil section configuring the return spring as a returning force of separating a pad from a rotor. Also, the invention implements a structure where the returning force, which is applied to an inner pad and an outer pad upon braking release, is made to be different, as required.
Solution to Problem
[0021] The invention provides a floating disc brake, a method of assembling the same and an assembly of a pad clip and a return spring. Like the floating disc brake that has been well known and has been described above, the floating disc brake of the invention has a support, a pair of pads, a caliper, pad clips and return springs.
[0022] The support is fixed to a vehicle body in the vicinity of a rotor rotating together with wheels.
[0023] Also, each of the pads has a lining provided on a surface (surface of both axial side surfaces facing an axial side surface of the rotor) of a pressure plate (it doesn't care whether the pressure plate and the lining are separate members or integrally formed). Both the pads are arranged at both axial sides of the rotor and are moveably guided in an axial direction of the rotor by the support.
[0024] Also, the caliper is axially displaceable in the axial direction of the rotor with being supported to the support.
[0025] Also, the pad clips are provided between the respective pads and the support and prevent the respective pads from moving with respect to the support. Also, the return springs press the pad toward a direction getting away from the rotor.
[0026] Particularly, in the floating disc brake of the invention, at a state before both the pads are mounted, a part of the pad clip is provided with a constraining section receiving an elastic urging force of the return spring to thus support the return spring so as to enable the return spring to be mounted to the pad clip.
[0027] Also, the pad clip is arranged between the support and the pressure plate configuring the pad and has a leg section having the constraining section provided at a part thereof.
[0028] Also, the return spring is formed by bending a wire rod and has an abutting section that is abutted to the constraining section by an elastic restoring force thereof, an extension arm section extending toward the rotor-side, a returning section provided at a rotor-side end portion of the extension arm section, an engaging section that is engaged to a part of the pad clip and receives a reactive force to the pressing of the returning section to the pad and a coil section that is provided between the returning section and the engaging section and has a central axis substantially oriented in a rotational direction of the rotor.
[0029] The returning section contacts a surface of a part of a circumferential end portion of the pressure plate, the part protruding in a circumferential direction more than a circumferential end edge of the lining, and the surface facing a side surface of the rotor.
[0030] In the meantime, a trajectory of the returning section is preferably parallel with the central axis of the rotor as much as possible until the pads (linings) are almost worn from a state of new products. To this end, for example, when mounting the pads, the extension arm section can be arranged to be substantially parallel with the central axis of the rotor. In the meantime, the configuration of “substantially parallel” means a state close to parallel so that the elastic urging force of the return spring can be efficiently transferred to the pressure plate of the pad. An angle of the extension arm section changes as the lining of the pad is worn. Thus, the configuration of “substantially parallel” is not limited to the completely parallel configuration. For example, at a state close to parallel, i.e., at a state of the pad mounting, irrespective of a thickness (a degree of the wear) of the lining, the configuration of “substantially parallel” means a state where an inclined angle of the extension arm section with respect to the central axis is within ±15°, preferably within ±10°, more preferably within ±50.
[0031] Also, the state where the central axis of the coil section is substantially oriented in the rotational direction of the rotor means a state where the rotational direction (tangential direction) at the circumferentially central portion of the pad and the central axis are matched. However, the state is not limited to a case where the rotational direction and the direction of the central axis are completely matched and includes a case where the directions are slightly deviated (for example, within ±20°, preferably within ±10°).
[0032] According to the floating disc brake configured as described above, when mounting the pad clips, it is possible to handle the pad clips and the return springs as integral articles (assemblies, subassemblies), thereby facilitating the mounting operation.
[0033] That is, according to the invention, the pad clips are provided at parts thereof with the constraining sections, so that it is possible to receive the elastic urging force of the return springs and to thus support the return springs to the pad clips with the sufficient supporting force corresponding to the elastic urging force. Therefore, it is possible to handle the pad clips and the return springs as integral articles, so that it is possible to perform the operations of mounting the pad clips and the return springs at the same time, thereby facilitating the mounting operation. As a result, it is possible to improve the assembling performance, thereby reducing the assembling cost.
[0034] Also, it is possible to easily handle the assemblies of the pad clips and the return springs, and the burden on the management in the assembling factory of the disc brake is reduced by a half, compared to a case where the pad clips and the return springs are handled as separate articles. Also, it is possible to reduce the number of preparing processes, to prevent the mounting mismatch and to reduce the number of mounting processes. Also, it is possible to easily sale a part for replacement and the like in markets.
[0035] Also, according to the invention, since the return spring is provided with the coil section, it is possible to lower a constant of spring, compared to a configuration where the return spring is configured by a wire spring having no coil section. Therefore, even when amounts of wear of the linings of the pads are varied and amounts of axial movement of the pads are thus varied upon the braking, it is possible to lower the change in the elastic urging force to be applied to the pads. Also, since the central axis of the coil section is arranged in the rotational direction of the rotor, the coil section can be provided in a gap between an end portion of the pressure plate of the pad and the support. Also, it is possible to efficiently transfer the elastic urging force of the coil section to the returning section and engaging section of the return spring. Therefore, it is possible to further lower the elastic coefficient of the return spring, so that it is possible to further suppress the change in the elastic urging force with which the returning section presses the pad, which change is caused as the lining of the pad undergoes the wear.
[0036] When implementing the floating disc brake as described above, preferably, at least a part of the returning section is positioned on a virtual plane passing through the coil section of virtual planes orthogonal to the central axis of the coil section. In other words, the circumferential positions of the coil section and the part of the returning section are matched (the positions are made to overlap each other in the circumferential direction).
[0037] According to this configuration, the circumferential positions of the coil section and the part of the returning section are matched, so that the coil section is elastically deformed in a torsion direction (rolling-in direction). Therefore, it is possible to effectively use the elastic deformation (elastic urging force) of the coil section as a restoring force separating the pad from the rotor.
[0038] Also, when implementing the floating disc brake of the invention, preferably, the coil section and the returning section overlap each other in the axial direction of the rotor. More preferably, the central axis of the coil section and the returning section are made to overlap each other in the axial direction of the rotor. In this case, at a state where a new pad is mounted, the coil section and the returning section preferably overlap each other in the axial direction of the rotor.
[0039] According to this configuration, an operating direction of the returning force by the returning section is substantially matched with the axial direction that is a moving direction of the rotor. Therefore, it is possible to effectively separate the pad from the rotor.
[0040] Also, when implementing the floating disc brake of the invention, preferably, a diametrical position of the returning section substantially matches with a friction center of the pad. In this case, the configuration “substantially match” is not limited to a completely matched state, although the completely matched state is most preferable. That is, a state where the position is deviated from the completely matched state in the diametrical direction within ±10% (more preferably, ±5%) of a width size of a friction surface (surface of the lining, which is frictionally engaged with the side surface of the rotor upon the braking) of the pad in the diametrical direction is also the substantially matched state. Actually, a diametrical position of the returning section is constrained so that it is within a range of a protruding part (engaging protruding piece) that is provided at a circumferential end portion of the pressure plate and circumferentially protrudes more than a circumferential end edge of the lining (more specifically, the diametrical position of the returning section is constrained to a diametrically inner position of the most circumferentially protruding part of the engaging protruding piece). When the diametrical position is constrained as described above, the diametrical position of the returning section is substantially matched with the friction center of the pad.
[0041] According to the above configuration, at a state where the braking is released, it is possible to effectively prevent the pad from being inclined to the rotor and any one peripheral edge of inner and outer peripheral edges of the pad from rubbing with the side surface of the rotor.
[0042] Also, when implementing the invention, preferably, a position at which the returning section and the pressure plate contact and a position of the engaging section substantially match in a circumferential direction of the rotor. Meanwhile, in this case, the configuration “substantially match” means that both the positions are matched in the circumferential direction so that the moment of a direction rotating about the diametrical axis of the rotor is not caused in the return spring by a couple of force of a force that is applied to the return spring from a contact part between the returning section and the pressure plate and a force that is applied to the return spring from an engaged part of the engaging section and the pad clip or the moment is negligibly small even though it is caused. For example, the returning section and the pressure plate contact within a somewhat length range in the circumferential direction. Therefore, when the position of the engaging section is within the length range, the moment is not caused. This state is a state where the contact position and the position of the engaging section are matched.
[0043] According to the above configuration, the elastic urging force in a direction getting away from the rotor is applied to the pad by the return spring, so that the moment of a direction rotating about the diametrical axis is not caused in the return spring or the moment is negligibly small even though the moment occurs. Therefore, even when the return spring is configured by the inner spring element and the outer spring element, which are separate elements, it is possible to prevent both the spring elements from inadvertently separating from the pad clip.
[0044] Also, when implementing the invention, preferably, a direction along which the returning section presses the pressure plate and a direction along which the engaging section presses the pad clip are the substantially axial direction of the rotor and are the opposite directions each other. Meanwhile, in this case, the substantially axial direction includes a case where the direction of the force with which the respective sections press the other sections completely matches with the axial direction of the rotor and also a case where a difference between the pressing direction and the axial direction is small (45° or smaller, preferably 30° or smaller) and an axial component force of component forces of the force with which the respective sections press the other sections is large (70% or larger, preferably 85% or larger).
[0045] According to the above configuration, it is possible to effectively transfer the elastic urging force of the return spring to the pad, as the force separating the pads from the rotor (separating both the pads). Therefore, even though a return spring (for example, a thick wire rod) having particularly high elastic urging force is not used, it is possible to securely separate the pads. Since it is not necessary to particularly increase the elastic urging force of the return spring, it is possible to suppress the processing cost of the return spring and to facilitate the mounting operation of the return spring. This invention is also effective in a case where it is combined with the structure where the return spring is configured by the inner spring element and the outer spring element, which are separate elements.
[0046] Also, when implementing the invention, preferably, the leg section of the pad clip is provided at a diametrically central portion thereof with a positioning step section having a substantially U-shaped section and protruding toward the pad in a circumferential direction, and the positioning step section is elastically fitted onto an outer side of a protrusion section formed on a part of the support. The positioning step section holds the protrusion section, thereby positioning the pad clip in a diametrical direction. Also, the engaging section of the return spring is engaged into an engaging hole that is formed at a part of a leading end portion of the positioning step section, the part protruding more than a leading end surface of the protrusion section. That is, instead of a configuration where both inner surfaces (both diametrically side surfaces) of the positioning step section and both outer surfaces (both diametrically side surfaces) of the protrusion section are contacted over the substantial entire width in the axial direction of the rotor, the leading end portion of the positioning step section is made to protrude in the circumferential direction of the rotor slightly more than the leading end portion of the protrusion section, so that a gap is formed between the inner surface of the leading end portion of the positioning step section and the leading end surface of the protrusion section. The engaging section is inserted into the gap through the engaging hole.
[0047] According to the above configuration, it is possible to bring the positioning step section of the pad clip-side into contact with the protrusion section of the support-side over the substantial entire width. Therefore, it is possible to increase the support rigidity of the pad clip to the support. Also, it is possible to bring the provision position of the engaging section of the return spring close to the circumferentially central portion of the support, thereby easily implementing the structure of the invention.
[0048] Also, when implementing the invention, preferably, a concave recess in which the returning section can be housed is formed on the surface of the circumferential end portion of the pressure plate to which surface the returning section is contacted. Then, the returning section is housed in the concave recesses.
[0049] According to the above configuration, even when an amount of wear of the lining configuring each pad is increased (until the lining is completely worn), it is possible to reduce the sliding between the returning section and the side surface of the rotor, so-called the drag. Therefore, while effectively using (source saving) the lining, it is possible to reduce the relative sliding, thereby reducing the wear of the rotor sliding surface.
[0050] Also, when implementing the invention, preferably, an axially central portion of the extension arm section is inserted into the recess in the axial direction of the rotor, which recess is formed at the circumferential end edge of the pressure plate.
[0051] According to the above configuration, it is possible to realize a structure where the returning section is brought into contact with the circumferential end portion side surface (surface facing the rotor), without unnecessarily complicating the shapes of the return spring, the pad clip and the like.
[0052] Also, when implementing the invention, preferably, the constraining section and the abutting section are offset toward an opposite side to the pad in the circumferential direction more than a surface of the pad clip circumferentially facing a circumferential end surface of the pressure plate.
[0053] Also, when implementing the invention, preferably, the constraining section extends from a torque receiving section of the leg section toward an opposite side to the rotor in the axial direction of the rotor, the torque receiving section being provided so as to elastically press a circumferential end portion of the pad in a circumferential direction.
[0054] Also, when implementing the invention, preferably, the constraining section extends from a step section of the leg section toward an opposite side to the rotor in the axial direction of the rotor, the step section being provided so as to be engaged with a part of the support and thus to diametrically position the pad clip with respect to the support.
[0055] Also, when implementing the invention, preferably, the pad clip has a pair of leg sections each of which is arranged between the support and each of the pads. Also, the return spring has an abutting section, an extension arm section, a returning section and a coil section in a pair, respectively.
[0056] Also, when implementing the invention, preferably, both end portions of the pad clip are provided with constraining sections, and at a state where the abutting sections of the return spring are abutted to both the constraining sections, both the constraining sections engage a central portion of the return spring. A part of the return spring except for the returning sections is prevented from being inclined to thus protrude toward a center of the support in a circumferential direction of the rotor, so that both the pads are enabled to be easily mounted to the support (the mounting property of the pad is favorably made).
[0057] According to the above configurations, when mounting the pads, it is possible to effectively prevent the pressure plate, the constraining section and the abutting section from interfering with each other, so that it is possible to improve the operation efficiency of the mounting operation of the pads.
[0058] Also, when implementing the invention, preferably, the return spring is formed by bending one wire rod, the engaging section is omitted and the coil sections are connected by a connection arm section provided to extend over the rotor.
[0059] According to the above configuration, it is possible to reduce the number of parts and the number of mounting processes of the return spring to the pad clip (one mounting is sufficient).
[0060] Alternatively, the return spring has an inner spring element and an outer spring element, which are separate elements. Each of the inner and outer spring elements is provided with the abutting section, the extension arm section, the returning section, the engaging section and the coil section, respectively.
[0061] According to the above configuration, the shapes, the line diameters and the like are different between both the spring elements. Thereby, it is possible to easily make the elastic urging force to be applied to the inner pad and the outer pad different. Therefore, the elastic urging force to be applied to the outer pad is made to be larger than the elastic urging force to be applied to the inner pad, so that it is possible to lower the amount of wear of the lining of the outer pad in which the amount of wear thereof is apt to increase.
[0062] Also, when implementing the invention, preferably, the pad clip has an inner clip element and an outer clip element that have the constraining section, respectively, and are separate elements.
[0063] According to the above configuration, it is possible to make the pad clip (clip elements) smaller/lighter, compared to a configuration where the entire pad clip is integrally formed (for example, a portal in which a pair of leg sections is connected by a connection section). Therefore, it is possible to improve the handling property of the pad clip, thereby improving the mounting operability of the pad clip. Also, it is possible to reduce the material cost for forming the pad clip. Also, irrespective of the thickness (axial size) of the rotor to be combined and used, it is possible to use the pad clip (it is possible to commonalize the pad clip elements).
[0064] Compared to this, for a portal in which a pair of leg sections is connected by a connection section, it is possible to improve the mounting property to the support (the number of mounting operations is reduced) and to enable the mounting (clamp) to the support with good precision. For example, by using a processing surface of a part (rotor pass part) of the support, which is provided to extend over the rotor, it is possible to maintain (to position) the backside of the connection section of the pad clip with good precision.
[0065] Also, when implementing the invention, preferably, the return spring has a pair of coil sections, which is separated from each other in the axial direction of the rotor, and a pair of outer arm sections extending from the respective coil sections toward an opposite side to the rotor in the axial direction of the rotor and having an abutting section at a part thereof, respectively.
[0066] In the meantime, the pad clip is configured so that the diametrically outer end portions of the pair of leg sections are connected by a connection section having an engaging notch or engaging hole into which a part of the return spring can be engaged. Also, each leg section is provided with a step section that is engaged with a part of the support and positions the pad clip with respect to the support in the diametrical direction.
[0067] The abutting section that is provided at the part of each outer arm section is enabled to abut on the constraining section with the elastic urging force being applied toward the direction separating from the rotor in the axial direction of the rotor, and the engaging section (engaging section provided to the inner arm section extending from the coil section toward the rotor in the axial direction of the rotor or the connection arm section having a shape connecting a pair of the inner arm sections), which is provided between both the coil sections of the return spring in the axial direction of the rotor, is engaged into the engaging notch or engaging hole with the elastic urging force being applied in the diametrically outer side so that the engaging section cannot be axially displaced.
[0068] At this state, the diametrically inner end portion of each coil section is elastically pressed to the diametrically outer surface of each positioning step section toward the diametrical inner side.
[0069] Alternatively, when implementing the invention, preferably, the return spring has an inner spring element and an outer spring element which have a coil section and a pair of arm sections, respectively, and are separate elements.
[0070] Also, each leg section configuring the pad clip is provided with a step section that is engaged with a part of the support to thus position the pad clip with respect to the support in a diametrical direction and a folding section that is formed by folding a diametrically central portion of the step portion into a substantial U shape with bent at a substantial right angle from a diametrically outer surface of the step section toward a diametrically outer side.
[0071] The abutting section provided to a part of an outer arm section of the arm sections configuring the inner and outer spring elements is abutted to each constraining section with an elastic urging force being applied in a direction getting away from the rotor in the axial direction of the rotor, the outer arm section extending from each coil section to an opposite side to the rotor in the axial direction of the rotor.
[0072] The engaging section, which is provided to a part of an inner arm section extending from each coil section toward the rotor in the axial direction of the rotor, is engaged to a part of the pad clip with an elastic urging force being applied toward the rotor in the axial direction of the rotor.
[0073] Also, at the above state, each coil section is mounted to a part surrounded by the diametrically outer surface of each step portion and each folding section.
[0074] According to the above configuration, it is possible to stabilize a posture (shape) of the return spring. Therefore, it is possible to effectively prevent the return spring from separating from the pad clip or the mounting position from deviating. Therefore, it is possible to improve the operability of the mounting operation of the pad clip and the return spring to the support. Also, at a state where the pad clip and the return spring are mounted to the support, it is possible to easily apply the desired elastic urging force (returning force) to the pad by the return spring.
[0075] Also, when implementing the invention, preferably, the engaging section provided to the leading end portion of each inner arm section is engaged into the engaging hole formed on the diametrically outer surface of each step section.
[0076] Also, a method of assembling a floating disc brake according to the invention is a method of assembling the floating disc brake. After elastically deforming the return spring, the elastic deformation is released to abut the abutting section provided to a part of the return spring to a constraining section of the pad clip by an elastic restoring force of the return spring, and the return spring is mounted to the pad clip. After that, the pad clip and the return spring are mounted to the support at the same time. Then, both the pads are mounted to the support.
[0077] Also, an assembly of a pad clip and a return spring according to the invention includes a pad clip and a return spring.
[0078] The pad clip has a leg section that is arranged between a support and a pad configuring a disc brake and a constraining section that is formed at a part of the leg section.
[0079] Also, the return spring is formed by bending a wire rod and has a coil section, an abutting section that is provided at a part of an arm section extending from the coil section and a returning section that is provided at a leading end portion of the arm section and contacts a part of the pad to thus press the pad in a direction getting away from the rotor.
[0080] The coil section is arranged so that a central axis thereof is substantially perpendicular to both surfaces (a surface facing the pad in the circumferential direction and an opposite surface thereto) of the leg section, and the abutting section is abutted to the constraining section by an elastic restoring force of the return spring.
[0081] Thereby, the return spring is supported (mounted) to the pad clip, thereby configuring the assembly of the pad clip and the return spring.
[0082] Meanwhile, in the assembly of the pad clip and the return spring, the return spring may be supported to the pad clip, and the return spring may be supported at a state before the pad clip is mounted to the support or after the pad clip is mounted to the support.
BRIEF DESCRIPTION OF DRAWINGS
[0083] FIG. 1 is a perspective view of a floating disc brake according to a first embodiment of the invention, which is seen from an outer diameter side and an outer side with a caliper being omitted.
[0084] FIG. 2 is an orthographic view of the floating disc brake shown in FIG. 1 , which is seen from an outer diameter side.
[0085] FIG. 3 is an orthographic view of the floating disc brake shown in FIG. 1 , which is seen from an inner side.
[0086] FIG. 4 is a perspective view showing a state (assembly) where a return spring is mounted to a pad clip shown in FIG. 1 , which is seen from an outer diameter side and a front side.
[0087] FIG. 5 is a perspective view showing a state (assembly) where the return spring is mounted to the pad clip shown in FIG. 1 , which is seen from an inner diameter side and a backside.
[0088] FIGS. 6A to 6C show a state (assembly) where the return spring is mounted to the pad clip shown in FIG. 1 , in which FIG. 6A is a front view, FIG. 6B is a plan view and FIG. 6C is a side view.
[0089] FIGS. 7A to 7C show only one spring element configuring the return spring shown in FIG. 1 and elastically deformed to a mounted state to the pad clip, in which FIG. 7A is a front view, FIG. 7B is a plan view and FIG. 7C is a side view.
[0090] FIGS. 8A and 8B show two examples of a recess that is formed at an engaging protruding piece of a pressure plate shown in FIG. 1 .
[0091] FIG. 9 is a perspective view showing a state (assembly) where a return spring according to a second embodiment of the invention is mounted to the pad clip, which is seen from an outer diameter side and a front side.
[0092] FIG. 10 is a perspective view of a floating disc brake according to a third embodiment of the invention, which is seen from an outer diameter side and an inner side with a caliper being omitted.
[0093] FIG. 11 is an orthographic view of the floating disc brake shown in FIG. 10 , which is seen from an outer diameter side.
[0094] FIG. 12 is an orthographic view of the floating disc brake shown in FIG. 10 , which is seen from an inner side.
[0095] FIG. 13 is a perspective view showing the floating disc brake shown in FIG. 10 before a pad is mounted.
[0096] FIG. 14 is an orthographic view of the floating disc brake shown in FIG. 10 , which is seen from an outer diameter side.
[0097] FIG. 15 is an orthographic view of the floating disc brake shown in FIG. 10 , which is seen from an inner side.
[0098] FIG. 16 is a perspective view showing a state (assembly) where a return spring is mounted to a pad clip shown in FIG. 10 , which is seen from an outer diameter side and a front side.
[0099] FIGS. 17A and 17B show a state (assembly) where the return spring is mounted to the pad clip shown in FIG. 10 , in which FIG. 17A is a front view and FIG. 17B is a plan view.
[0100] FIGS. 18A and 18B show two examples of one spring element configuring the return spring shown in FIG. 10 .
[0101] FIG. 19 is a perspective view of a floating disc brake according to a fourth embodiment of the invention, which is seen from an outer diameter side and an inner side with a caliper being omitted.
[0102] FIG. 20 is an orthographic view of the floating disc brake shown in FIG. 19 , which is seen from an outer diameter side.
[0103] FIG. 21 is an orthographic view of the floating disc brake shown in FIG. 19 , which is seen from an inner side.
[0104] FIG. 22 is a perspective view showing a state (assembly) where a return spring is mounted to a pad clip shown in FIG. 19 , which is seen from an outer diameter side and a front side.
[0105] FIG. 23 is a perspective view showing only one spring element configuring the return spring shown in FIG. 19 and elastically deformed to a mounted state to the pad clip.
[0106] FIG. 24 is a perspective view showing a floating disc brake according to a fifth embodiment of the invention before a pad is mounted, which is seen from an outer diameter side and an inner side.
[0107] FIG. 25 is a perspective view showing a state (assembly) where one spring element configuring a return spring is mounted to one clip element configuring a pad clip shown in FIG. 24 .
[0108] FIGS. 26A to 26C show a state (assembly) where one spring element is mounted to one clip element shown in FIG. 25 , in which FIG. 26A is a front view, FIG. 26B is a plan view and FIG. 26C is a side view.
[0109] FIG. 27 is a perspective view of a floating disc brake according to a sixth embodiment of the invention, which is seen from an outer side and a diametrically outer side with a rotor being omitted.
[0110] FIG. 28 is a perspective view showing a caliper of FIG. 27 with a part thereof being cut.
[0111] FIG. 29 is a perspective view showing a state where each spring element is elastically deformed to a mounted state to a pad except for the caliper and pad shown in FIG. 27 .
[0112] FIG. 30 is an enlarged view of an X part shown in FIG. 29 .
[0113] FIG. 31 is a sectional view taken along a line Y-Y of FIG. 29 , which shows the return spring of FIG. 29 before it is mounted to a pad.
[0114] FIG. 32 is a sectional view taken along a line Y-Y of FIG. 29 , which shows the return spring of FIG. 29 after the return spring is elastically deformed as it is mounted to the pad.
[0115] FIG. 33 is a view corresponding to a left side of FIGS. 31 and 32 , which shows that the return spring is elastically deformed as it is mounted to the pad.
[0116] FIG. 34 is an orthographic view showing a state where the pad is mounted to the support to which the pad clip and the return spring shown in FIG. 27 are mounted, which is seen from a diametrically outer side.
[0117] FIG. 35 is an orthographic view showing a state where the pad is mounted to the support to which the pad clip and the return spring shown in FIG. 27 are mounted, which is seen from an outer side.
[0118] FIG. 36 is an orthographic view showing a state where the pad is mounted to the support shown in FIG. 35 , which is seen from a left side.
[0119] FIG. 37 is a front view showing an assembly of the pad clip and return spring shown in FIG. 27 .
[0120] FIG. 38 is a perspective view of a floating disc brake according to a seventh embodiment of the invention, which is seen from an outer diameter side and an outer side with a pad and a caliper being omitted.
[0121] FIG. 39 is a perspective view showing the floating disc brake shown in FIG. 38 , which is seen from an outer diameter side and an inner side.
[0122] FIG. 40 is an orthographic view showing the floating disc brake shown in FIG. 38 , which is seen from an outer diameter side.
[0123] FIG. 41 is an orthographic view showing the floating disc brake shown in FIG. 38 , which is seen from an outer side.
[0124] FIG. 42 is a partially enlarged view of FIG. 38 .
[0125] FIG. 43 is a perspective view showing an assembly of the pad clip (element) and return spring (element) shown in FIG. 38 .
[0126] FIG. 44 is a perspective view of a floating disc brake according to an eighth embodiment of the invention, which is seen from an outer diameter side and an outer side with a pad and a caliper being omitted.
[0127] FIG. 45 is a perspective view showing the floating disc brake shown in FIG. 44 , which is seen from an outer diameter side and an inner side.
[0128] FIG. 46 is an orthographic view showing the floating disc brake shown in FIG. 44 , which is seen from an outer diameter side.
[0129] FIG. 47 is an orthographic view showing the floating disc brake shown in FIG. 44 , which is seen from an outer side.
[0130] FIG. 48 is a partially enlarged view of FIG. 44 .
[0131] FIG. 49 is a perspective view showing an assembly of the pad clip and return spring shown in FIG. 44 .
[0132] FIG. 50 is a perspective view of a floating disc brake according to a ninth embodiment of the invention, which is seen from an outer diameter side and an outer side with a pad and a caliper being omitted.
[0133] FIG. 51 is a perspective view showing the floating disc brake shown in FIG. 50 , which is seen from an outer diameter side and an inner side.
[0134] FIG. 52 is an orthographic view showing the floating disc brake shown in FIG. 50 , which is seen from an outer diameter side.
[0135] FIG. 53 is an orthographic view showing the floating disc brake shown in FIG. 50 , which is seen from an outer side.
[0136] FIG. 54 is an orthographic view showing the floating disc brake shown in FIG. 53 , which is seen from a right side.
[0137] FIG. 55 is a partially enlarged view of FIG. 50 .
[0138] FIG. 56 is a perspective view showing an assembly of the pad clip (element) and return spring (element) shown in FIG. 50 .
[0139] FIG. 57 is a partially sectional view of a first example of a floating disc brake according to the prior art, which is seen from an outer diameter side.
[0140] FIG. 58 is a partially cut perspective view of a second example of the prior art.
[0141] FIG. 59 is a perspective view of a third example of the prior art with parts being removed.
DESCRIPTION OF EMBODIMENTS
First Embodiment
[0142] FIGS. 1 to 9 show a first embodiment of the invention. In the meantime, a feature of the invention relates to a structure of a pad clip 15 a and a return spring 16 a so as to easily perform a mounting operation of the pad clip 15 a and the return spring 16 a, including a structure of the first embodiment. The other structures and operational effects are the substantially same as those of the first example of the prior art. Thus, the illustration and description of the equivalent parts will be omitted or simplified. Hereinafter, features of the first embodiment of the invention will be described.
[0143] Also in the first embodiment, engaging protruding pieces 21 , 21 that are provided at both circumferential end portions of pressure plates 10 a, 10 b configuring inner and outer pads 9 a, 9 b are engaged to engaging recesses 20 , 20 that are formed at rotation input side and rotation output side engaging sections 7 , 8 , which are provided at both circumferential end portions of a support 3 . Thereby, the pads 9 a , 9 b are axially displaceably supported. Also, the pad clips 15 a, 15 b are respectively interposed between the respective engaging recesses 20 , 20 and the respective engaging protruding pieces 21 , 21 . Each of the pad clips 15 a, 15 a is formed by bending a metal plate having elasticity and corrosion resistance such as stainless spring steel and has a pair of axially spaced leg sections 22 , 22 and a connection section 23 connecting diametrically outer end portions of the leg sections.
[0144] Each leg section 22 has a positioning step section 36 , a torque receiving section 37 and a bent section 38 , which are continuous in the diametrical direction. The positioning step section 36 circumferentially protrudes at a diametrically central portion of the leg section 22 toward each pad 9 a, 9 b, has a substantially U-shaped section and is engaged with a protrusion section 39 formed at a part of the support 3 (the protrusion section 39 is elastically fitted/held at an outer side of the positioning step section) to thus position each pad clip 15 a in the diametrical direction. Also, the torque receiving section 37 is bent at a substantially right angle from a diametrically inner surface of the positioning step section 36 toward a diametrically inner side and elastically presses each engaging protruding piece 21 provided at the circumferential end portion of each of the pads 9 a, 9 b. Also, the bent section 38 is circumferentially bent from a diametrically inner end portion of the torque receiving section 37 toward each of the pads 9 a, 9 b and elastically contacts a diametrically inner surface of each engaging protruding piece 21 .
[0145] In particular, in the first embodiment of the invention, both axial end portions of each of the pad clips 15 a, 15 a are provided with a pair of constraining sections 24 , 24 at parts more axially spaced from the rotor 1 (refer to FIG. 2 ) than the pressure plates 10 a, 10 b configuring the respective pads 9 a, 9 b. Each of the constraining sections 24 , 24 is formed by bending a central portion of the torque receiving section toward each of the pads 9 a, 9 b in the circumferential direction with extending in a direction axially separating from each of the torque receiving sections 37 , 37 provided at inner-diametrically biased parts of the respective leg sections 22 , 22 . The constraining sections 24 , 24 having the above configuration are provided so as to mount the return spring 16 a to each pad clip 15 a (so as to configure an assembly of the pad clip 15 a and the return spring 16 a ) before both pads 9 a, 9 b are mounted, receive an elastic urging force (returning force) of each return spring 16 a and supports each return spring 16 a. Also, protruding pieces 25 , 25 are provided at outer-diametrically biased parts of the leg sections 22 , 22 , i.e., at parts bent at a substantially right angle from diametrically outer surfaces of the respective positioning step sections 36 , 36 toward a diametrically outer side. Each of the protruding pieces 25 , 25 is formed by forming a U-shaped slit at the outer-diametrically biased part of each of the leg sections 22 , 22 and bending an inner side of the slit toward the caliper (direction coming close to each other).
[0146] The pad clips 15 a, 15 a having the above configuration are respectively provided at an anchor side (a brake torque receiving side) of the disc brake and at an opposite side to the anchor. The leg sections 22 , 22 configuring each of the pad clips 15 a, 15 a are arranged between outer surfaces of the engaging protruding pieces 21 , 21 provided at the end portions of the respective inner and outer pads 9 a, 9 b and inner surfaces of the engaging recesses 20 , 20 formed at the rotation input side and rotation output side engaging sections 7 , 8 . By the torque receiving sections 37 , 37 of the respective leg sections 22 , 22 , the respective engaging protruding pieces 21 , 21 are elastically pressed in the circumferential direction, so that the respective pads 9 a , 9 b are prevented from rattling with respect to the support 3 . Also, at this state, the connection section 23 is positioned at the diametrically outer side of the outer periphery of the rotor 1 and connects the diametrically outer end portions of the leg sections 22 , 22 .
[0147] Also, in order to separate friction surfaces of linings 14 a, 14 a configuring the respective pads 9 a, 9 b from both side surfaces of the rotor 1 as the braking is released, the return springs 16 a, 16 a are provided at both circumferential end portions of the respective pads 9 a, 9 b. In the first embodiment, each of the return springs 16 a , 16 a is configured by an inner spring element 26 a and an outer spring element 26 b , which are separate elements. As shown in FIG. 7 , each of the spring elements 26 a , 26 b is a torsion coil spring that is formed by bending a wire rod of stainless spring steel such as piano line and in which base sections of a pair of arm sections 28 a, 28 b (inner arm section 28 a, outer arm section 28 b ) continue from a coil section 27 provided at an axially central portion.
[0148] The coil section 27 has an inner diameter enabling the protruding piece 25 of the pad clip 15 a to insert therein and has a central axis that is substantially oriented in a rotational direction of the rotor 1 (which is a rotational direction (tangential direction) of the rotor 1 at the circumferentially central portion of the pads 9 a, 9 b, is perpendicular to both surfaces of the leg section 22 and is a left-right direction of FIG. 2 ).
[0149] Also, a leading end portion of the inner arm section 28 a axially extending toward the rotor 1 of both the arm sections 28 a, 28 b is circumferentially bent toward the pad clip 15 a (opposite side to the pads 9 a, 9 b ) and serves as an engaging section 29 . Also, as required, as shown with the dashed-two dotted line in FIG. 5 , leading end portions of the respective engaging portions 29 , 29 are folded in the diametrically outer direction to thus configure deviation preventing pieces 40 , 40 . The respective deviation preventing pieces 40 , 40 are engaged on a backside of the connection section 23 to thus prevent each of the return springs 16 a from deviating from the pad clip 15 a.
[0150] Compared to this, the outer arm section 28 b extending toward an opposite side to the rotor 1 has a substantial L shape, when seen from the front, and has a curved section 30 , an abutting section 31 , an extension arm section 32 and a returning section 33 in order from a base end portion-side toward a leading end portion-side thereof. The abutting section 31 is a part that abuts on a surface (inner surface) of the constraining section 24 , 24 configuring the pad clip 15 a, which surface faces the side surface of the rotor 1 , by the elastic restoring force of each spring element 26 a ( 26 b ). In the first embodiment of the invention, the abutting section is linear and extends perpendicularly from an inner diameter-side end portion of the curved section 30 toward the diametrically inner side.
[0151] Also, the extension arm section 32 is bent at a substantial right angle from a diametrically inner end portion of the abutting section 31 in a direction coming close to the rotor 1 and is oriented so that it is substantially parallel with the central axis of the rotor 1 . Therefore, in the first embodiment, in order to prevent the extension arm section 32 and an circumferential end edge of each of the pressure plates 10 a, 10 b from interfering with each other, the engaging protruding pieces 21 , 21 of the respective pressure plates 10 a, 10 b are provided at the circumferential end edges thereof with recesses 34 ( 34 a ). An axially central portion of the extension arm section 32 is axially inserted into each recess 34 ( 34 a ). Specifically, the axially central portion of the extension arm section 32 is inserted into the recess 34 that is opened in the circumferential direction only, as shown in FIG. 8A , or inserted into the recess 34 that is opened in the circumferential direction and diametrical direction (inner side), as shown in FIG. 8B . Also, in the first embodiment, an axial length of the extension arm section 32 is constrained as follows. That is, the axial length of the extension arm section 32 is made to be larger than an axial thickness of each of the pads 9 a, 9 b and is made to be a length enabling the returning section 33 to contact the surface (inner surface) of each of the engaging protruding pieces 21 , 21 facing the side surface of the rotor 1 with the abutting section 31 and the inner surface of the constraining section 24 being contacted each other at a state where both pads 9 a, 9 b are mounted (at the axial position of each of the pads 9 a, 9 b upon the non-braking).
[0152] Also, the returning section 33 is bent from a leading end portion (end portion of the rotor 1 -side) of the extension arm section 32 in a direction circumferentially separating from each pad clip 15 a (in an opposite side to the engaging section 29 ) and contacts the inner surface of each of the engaging protruding pieces 21 , 21 . Also, a part (a based end portion, in the shown example) of the returning section 33 is positioned on a virtual plane (refer to the dotted-dashed line Y in FIG. 7C ) passing through the coil section 27 of virtual planes orthogonal to the central axis (refer to the dotted-dashed line X in FIG. 7C ) of the coil section 27 . Also, the returning section 33 is located at a position (the lower part in FIG. 7C ) overlapping with the coil section 27 in the axial direction of the rotor 1 at a state where the return spring 16 a is mounted to the pad clip 15 a (at the state where the pads 9 a, 9 b are mounted). Also, a diametrical position of the returning section 33 is the substantially same as a diametrical position of a friction center of each of the linings 14 a, 14 b configuring the respective pads 9 a, 9 b.
[0153] Also, in the first embodiment, although not shown in the drawings, both the spring elements 26 a, 26 b may have different line diameters or shapes. Specifically, of the spring elements 26 a, 26 b, it is possible to make load (returning force) of the outer spring element 26 b (applying the elastic urging force to the outer pad 9 b ) arranged at the outer side of the rotor 1 larger than load (returning force) of the inner spring element 26 a (applying the elastic urging force to the inner pad 9 a ) arranged at the inner side. Also, it is possible to make the load (returning force) of the spring element, which is provided at an opposite side (entrance side, rotation input side) to the anchor, larger than the load (returning force) of the spring element, which is provided at the anchor side (exit side, rotation output side).
[0154] In the first embodiment having the pad clips 15 a and the return springs 16 a , when assembling the floating disc brake, the return springs 16 a are mounted (preset) to the pad clips 15 a, as shown in FIGS. 4 to 6 , at a state before the respective pads 9 a , 9 b are mounted to the support 3 . That is, as shown in FIGS. 4 to 6 , an assembly of the pad clip 15 a and the return spring 16 a is configured. To this end, specifically, at a state where the arm sections 28 a, 28 b configuring each of the spring elements 26 a , 26 b are elastically deformed in the direction coming close to each other, the protruding piece 25 is inserted into the coil section 27 and then the arm sections 28 a , 28 b are elastically returned (the elastic deformation is released). Thereby, the engaging section 29 provided at the leading end portion of the inner arm section 28 a is engaged on the inner peripheral edge of the connection section 23 with the elastic urging force being applied in the diametrically outer side, and the abutting section 31 provided at the outer arm section 28 b is enabled to abut on the inner surface of the constraining section 24 with the elastic urging force being axially applied in the direction separating from the rotor 1 . In other words, both the arm sections 28 a, 28 b of each of the spring elements 26 a, 26 b extend between the inner peripheral edge of the connection section 23 configuring the pad clip 15 a and the inner surface of the constraining section 24 . Thereby, the inner peripheral surface of the coil section 27 is pressed to the protruding piece 25 toward the rotor 1 in the diametrically inner side and axial directions. At this state, both the spring elements 26 a, 26 b (return spring 16 a ) are mounted to the pad clip 15 a. Also, the inner peripheral surface of the coil section 27 is pressed to the protruding piece 25 , so that the respective spring elements 26 a, 26 b are positioned with respect to the pad clip 15 a in the diametrical and axial directions.
[0155] In the meantime, the operation of mounting the return spring 16 a to the pad clip 15 a may be performed at an assembling factory of the disc brake or may be performed in advance at a supply source of parts (for example, a factory at which the pad clip 15 a and the return spring 16 a are manufactured). When performing the mounting operation at a supply source of parts, the assemblies of the pad clips 15 a and the return springs 16 a are carried, prepared and assembled in the assembling factory of the disc brake.
[0156] After the return spring 16 a is mounted to the pad clip 15 a (or after the mounted assembly is prepared) as described above, the assemblies of the pad clips 15 a and the return springs 16 a are mounted to the support 3 and then both the pads 9 a, 9 b are mounted to the support 3 , as shown in FIGS. 1 to 4 . In the first embodiment, at the state where both the pads 9 a, 9 b are mounted, the elastic urging force from the return springs 16 b is not applied to both the pads 9 a, 9 b yet. At a state where a caliper (not shown) is being mounted, both the pads 9 a, 9 b are made to slightly come close to each other (for example, 1 mm or smaller) and the elastic urging force in the direction getting away from each other is applied to both the pads 9 a, 9 b . At this state, the respective abutting sections 31 , 31 are slightly moved upward from the respective constraining sections 24 , 24 .
[0157] The floating disc brake of the first embodiment assembled as described above operates upon the braking and upon the braking release, as follows.
[0158] First, upon the braking, the pressure oil is supplied into a cylinder section provided to the caliper (not shown) and the lining 14 a of the inner pad 9 a is pressed to the inner surface of the rotor 1 from the upper to the lower in FIG. 2 . Thus, as a reaction to the pressing force, the caliper 2 is displaced upward in FIG. 2 , based on the sliding between both the guide pins and both the guide holes 5 , 5 , and the claw section presses the lining 14 b of the outer (a widthwise outer side of the vehicle and lower side in FIG. 2 ) pad 9 b to the outer surface of the rotor 1 . As a result, the rotor 1 is strongly held from both the inner and outer side surfaces, so that the braking is made. At this time, the returning sections 33 , 33 configuring the respective return springs 16 a, 16 a are pushed by the inner surfaces of the respective engaging protruding pieces 21 , 21 and are thus axially displaced along the direction approaching the rotor 1 . At the same time, the respective extension arm sections 32 , 32 are axially displaced and the respective abutting sections 31 , 31 are separated from the inner surfaces of the respective constraining sections 24 , 24 . As a result, an amount of bending of the respective outer arm sections 28 b, 28 b (an amount of elastic deformation of the coil section 27 ) is increased, compared to the non-braking.
[0159] Upon the braking release, the respective returning sections 33 , 33 are pressed to the inner surfaces of the respective engaging protruding pieces 21 , 21 , based on the elastic restoring force of the respective return springs 16 a, 16 a, and the elastic urging force is applied to both the pads 9 a, 9 b in the direction getting away from each other (the direction of separating the respective pads 9 a, 9 b from the rotor 1 ). Thereby, the friction surfaces of the linings 14 a, 14 b of both the pads 9 a, 9 b are separated from both the side surfaces of the rotor 1 . Particularly, in the first embodiment of the invention, the elastic urging force is applied to both the pads 9 a, 9 b until the respective abutting sections 31 , 31 abut on the inner surfaces of the respective constraining sections 24 , 24 , so that the elastic urging force is not applied when the abutting is made.
[0160] As clearly seen from the above descriptions, in the first embodiment, when mounting the respective pad clips 15 a, it is possible to handle the respective pad clips 15 a and the respective return springs 16 a as integral articles (assemblies, subassemblies), thereby facilitating the mounting operation.
[0161] That is, in the first embodiment, as described above, the respective pad clips 15 a are provided with the constraining sections 24 , 24 , so that it is possible to receive the elastic urging force of the respective return springs 16 a (spring elements 26 a , 26 b ) and to thus support the respective return springs 16 a to the respective pad clips 15 a with the sufficient supporting force corresponding to the elastic urging force. Therefore, it is possible to handle the respective pad clips 15 a and the respective return springs 16 a as integral articles (assemblies), so that it is possible to perform the operations of mounting the respective pad clips 15 a and the respective return springs 16 a at the same time, thereby facilitating the mounting operation. As a result, it is possible to improve the assembling performance, thereby reducing the assembling cost. Also, since it is possible to mount the respective return springs 16 a to the respective pad clips 15 a in a wide space in which the operation space is not limited, it is also possible to facilitate the mounting operation.
[0162] Also, in the first embodiment, at a state just after both the pads 9 a, 9 b are mounted (the caliper is not mounted yet), the elastic urging force is not applied to both the pads 9 a, 9 b. Thus, it is not necessary to consider a configuration of preventing both the pads 9 a, 9 b from separating axially from the support 3 . Also, the respective constraining sections 24 , 24 are engaged with the engaging protruding pieces 21 , 21 of the respective pads 9 a, 9 b, so that it is possible to prevent the respective pads 9 a , 9 b from separating from the support 3 . Accordingly, the assembling operation or conveying operation is not troublesome. Also, since it is possible to handle the respective pad clips 15 a and the respective return springs 16 a as integral articles, it is possible to reduce the part management cost.
[0163] Also, the operation of mounting the respective return springs 16 a to the respective pad clips 15 a may be performed in advance at the supply source of the parts, and the assemblies of the respective return springs 16 a and the respective pad clips 15 a may be delivered in the assembling factory of the disc brake. In this case, the burden on the management (delivery management, management of boxes and the like, number management, stock management, ordering management, storage place and the like) and the like is reduced by a half, compared to a case where the respective return springs 16 a and the respective pad clips 15 a are handled as separate articles. Also, it is possible to reduce the number of preparing processes, to prevent the mounting mismatch and to reduce the number of mounting processes.
[0164] Also, in the first embodiment, the inner peripheral surfaces of the respective coil sections 27 are elastically pressed to the respective protruding pieces 25 , so that it is possible to stabilize the postures (shapes) of the respective spring elements 26 a , 26 b. Therefore, it is possible to effectively prevent the respective return springs 16 a (spring elements 26 a, 26 b ) from separating from the respective pad clips 15 a or the mounting positions from deviating. Therefore, it is possible to improve the operability of the mounting operation of the respective pad clips 15 a and the respective return springs 16 a to the support 3 .
[0165] Also, it is possible to easily apply the desired returning force to both the pads 9 a, 9 b due to the respective return springs 16 a. Also, the respective return springs 16 a are composed of the torsion coil springs having the respective coil sections 27 , so that it is possible to lower a constant of the spring, compared to a configuration where a wire spring having no coil section is used. Therefore, even when the amounts of wear of the linings 14 a, 14 a of both the pads 9 a, 9 b are varied and amounts of axial movement of both the pads 9 a, 9 b are thus increased upon the braking, it is possible to lower (stabilize) the change in the elastic urging force to be applied to both the pads 9 a, 9 b. That is, it is possible to make the elastic urging force to be applied to both the pads 9 a, 9 b constant until the linings 14 a, 14 b are almost worn from a state of new products. Also, in the first embodiment, the part of each returning section 33 is positioned on the virtual plane Y passing through each coil section 27 of the virtual planes orthogonal to the central axis X of each coil section. Hence, the circumferential positions of the coil section 27 and the part (base end portion) of the returning section 33 are matched, so that the respective coil sections 27 are elastically deformed in a torsion direction (rolling-in direction) upon the braking. Therefore, it is possible to effectively use the elastic deformation (elastic urging force) of the respective coil sections 27 as the returning force of separating the respective pads 9 a , 9 b from the rotor 1 . Also, since the respective coil sections 27 and the respective returning sections 33 overlap with each other in the axial direction of the rotor 1 , it is possible to substantially match the operational direction of the returning force by the respective returning sections 33 with the axial direction of the rotor 1 that is the moving direction of the respective pads 9 a, 9 b. Accordingly, it is possible to effectively separate the respective pads 9 a, 9 b from the rotor 1 .
[0166] Also, in the first embodiment, the respective extension arm sections 32 are oriented in substantially parallel with the central axis of the rotor 1 and the diametrical positions of the respective returning sections 33 are matched with the diametrical positions of the friction centers of the linings 14 a, 14 b configuring the respective pads 9 a, 9 b. Accordingly, at the state where the braking is released, it is possible to effectively prevent both the pads 9 a, 9 b from being inclined to the rotor 1 and any one of both the inner and outer peripheral edges of both the pads 9 a, 9 b from rubbing with the side surface of the rotor 1 . Also, since the respective extension arm sections 32 are oriented in substantially parallel with the central axis of the rotor 1 , it is possible to easily make trajectories of the respective returning sections 33 , 33 parallel until the respective pads 9 a, 9 b (linings 14 a, 14 b ) are almost worn from a state of new products. Also, the circumferential end edges of the respective engaging protruding pieces 21 , 21 are formed with the recesses 34 ( 34 a ) and the respective extension arm sections 32 are axially inserted into the respective recesses 34 ( 34 a ). Hence, it is possible to realize a structure where the respective returning sections 33 , 33 are brought into contact with the inner surfaces of the respective engaging protruding pieces 21 , 21 , without unnecessarily complicating the shapes of the respective return springs 16 a (spring elements 26 a, 26 b ), the respective pad clips 15 a and the like.
[0167] Also, in the first embodiment, the respective return springs 16 a are composed of the inner spring element 26 a and the outer spring element 26 b. Thus, for example, it is possible to make the line diameter of the outer spring element 26 b smaller than the line diameter of the inner spring element 26 a. Therefore, it is possible to make the elastic urging force to be applied to the outer pad 9 b larger than the elastic urging force to be applied to the inner pad 9 a, so that it is possible to effectively lower the amount of wear of the lining 14 b of the outer pad 9 b in which the amount of wear thereof is apt to increase. Also, it is possible to suppress the thickness variation of the rotor 1 , so that it is possible to effectively prevent the judder from occurring. In addition to the configuration where the line diameters are different between the inner and outer spring elements 26 a, 26 b, the shapes at a free state and the windings of the coil section 27 may be made to be different, so that it is possible to make the elastic urging force to be applied to the outer pad 9 b and the elastic urging force to be applied to the inner pad 9 a different.
[0168] Meanwhile, when implementing the invention, concave recesses may be formed on the inner surfaces of the engaging protruding pieces 21 , 21 and the respective returning sections 33 may be housed in the concave recesses. According to this configuration, even when the amounts of wear of the linings 14 a, 14 b are increased (until the linings are completely worn), it is possible to prevent the respective returning sections 33 , 33 and the side surfaces of the rotor 1 from rubbing each other.
Second Embodiment
[0169] FIG. 9 shows a second embodiment of the invention. In the second embodiment, the return spring 16 b is integrally formed by bending one wire rod, differently from the first embodiment. The return spring 16 b has a shape connecting the leading end portion of the inner arm section 28 a of inner spring element 26 a and the leading end portion of the inner arm section 28 a (for example, refer to FIG. 4 ) of the outer spring element 26 b of the first embodiment. Specifically, the return spring 16 b has a connection arm section 35 provided at an axially central portion with being put on the rotor 1 (refer to FIG. 2 , for example), a pair of coil sections 27 a, 27 a continuing from both axial end portions of the connection arm section 35 and outer arm sections 28 b, 28 b having base portions continuing from the respective coil sections 27 a, 27 a. The configurations of the coil section 27 a and the outer arm section 28 b are the same as those of the first embodiment.
[0170] Also in the second embodiment using the return spring 16 b having the above configuration, when assembling the floating disc brake, the return spring 16 b is mounted to the pad clip 15 a by using the constraining sections 24 , 24 provided at both axial end portions of the pad clip 15 a. That is, as shown in FIG. 9 , an assembly of the pad clip 15 a and the return spring 16 a (inner spring element 26 a and outer spring element 26 b ) is configured. To this end, specifically, at a state where both the outer arm sections 28 b, 28 b configuring the return spring 16 b are elastically deformed in the approaching direction each other, the protruding pieces 25 , 25 formed at the pad clip 15 a are respectively inserted into the coil sections 27 a, 27 a without rattling and then the outer arm sections 28 b, 28 b are elastically returned (the elastic deformation is released). Thereby, the pair of abutting sections 31 , 31 configuring the return spring 16 b are elastically abutted on the inner surfaces of the respective constraining sections 24 , 24 by the elastic restoring force of the return spring 16 b. In other words, both the abutting sections 31 , 31 are made to extend between the inner surfaces of the respective constraining sections 24 , 24 . At this state, the return spring 16 b is mounted to the pad clip 15 a. Also in the second embodiment, the assemblies of the pad clips 15 a and the return springs 16 b are mounted to the support 3 (refer to FIG. 1 , for example) and then both the pads 9 a, 9 b (refer to FIG. 1 , for example) are mounted to the support 3 . Also in the second embodiment, as required, as shown with the dashed-two dotted line in FIG. 9 , the axially central portion of the connection arm section 35 configuring the return spring 16 b is made to protrude in a circumferential direction getting away from the caliper 2 (refer to FIGS. 27 , 28 and 57 ) and in the diametrically outer side, thereby forming a deviation preventing piece 40 a. The deviation preventing piece 40 a is engaged on the backside of the connection section 23 configuring the pad clip 15 a to thus prevent the return spring 16 b from separating from the pad clip 15 a. When the deviation preventing piece 40 a is provided, the deviation preventing piece 40 a is inserted between the leg sections 22 , 22 RL with being inclined with respect to the pad clip 15 a and the posture of the return spring 16 b is then returned to thus mount the return spring 16 b to the pad clip 15 a.
[0171] In the second embodiment using the return spring 16 b having the above described configuration and capable of performing the mounting operation as described above, the return spring 16 b is integrally formed. Thereby, compared to the case where the separate structures are adopted, like the first embodiment, it is possible to reduce the number of parts and the number of mounting processes to the pad clip 15 a. Also, both the coil sections 27 , 27 are connected by the connection arm section 35 , so that it is possible to omit the engaging sections 29 (refer to FIGS. 4 to 7 , for example) for receiving the reactive force to the pressing of the returning sections 33 , 33 to the respective pads 9 a, 9 b. Therefore, it is possible to perform the assembling operation (the operation of mounting the pad clips 15 a and the return springs 16 b ) more simply.
[0172] The other configurations and operational effects are the same as those of the first embodiment.
Third Embodiment
[0173] FIGS. 10 to 18 show a third embodiment of the invention. The features of this embodiment are that the support structure of a return spring 16 c to the pad clip 15 b is different from the first embodiment. Since the basic structures of the pad clip 15 b and the return spring 16 c are the substantially same as those of the first embodiment, the description of the common parts are omitted or simplified. Hereinafter, the features of the third embodiment are described.
[0174] As shown in FIG. 16 , also in the third embodiment, the pad clip 15 b is configured by connecting diametrically outer end portions of a pair of axially spaced leg sections 22 a, 22 a by a connection section 23 a. Particularly, in the third embodiment, the connection section 23 a is formed with a pair of engaging notches 41 , 41 for engaging parts (engaging sections 29 a that will be described later) of the respective return springs 16 c. The respective engaging notches 41 , 41 are opened to a diametrically inner end edge of the connection section 23 a and are spaced in the axial direction. Also, a diametrical depth of each of the engaging notches 41 , 41 is twice as large as the line diameter of the return spring 16 c and an axial width thereof is slightly larger than the line diameter. In the meantime, although not shown, instead of the engaging notches 41 , 41 , the connection section 23 a may be formed with a pair of engaging holes penetrating the connection section 23 a in the circumferential direction (plate thickness direction) and the engaging sections 29 a , 29 a that will be described later may be engaged into the respective engaging holes.
[0175] Also, in the third embodiment, while the connection section 23 a are formed with the engaging notches 41 , 41 , the outer-diametrically biased parts of the respective leg sections 22 a, 22 a, i.e., the parts bent from the diametrically outer surfaces of the respective positioning step sections 36 , 36 toward a diametrically outer side are configured by simple flat surfaces. That is, in the third embodiment, the protruding pieces 25 (refer to FIGS. 1 and 7 , for example) of the first and second embodiments are omitted.
[0176] Also, a pair of constraining sections 24 a, 24 a is provided at both axial end portions of each of the pad clips 15 b so as to mount the respective return springs 16 c to the respective pad clips 15 b at a state before the inner and outer pads 9 a, 9 b are mounted. Particularly, in the third embodiment, each of the constraining sections 24 a, 24 a is formed by bending a part of the torque receiving section, which is biased to the leading end side, toward an opposite side to the pads 9 a, 9 b in the circumferential direction with extending in a direction axially separating from each of the torque receiving sections 37 , 37 provided at inner-diametrically biased parts of the respective leg sections 22 a, 22 a. Thereby, in the third embodiment, the respective constraining sections 24 a, 24 a are provided (offset) at the opposite sides to the pads 9 a, 9 b in the circumferential direction than the inner surfaces (surfaces circumferentially facing the circumferential end surfaces of the engaging protruding pieces 21 , 21 ) of the respective torque receiving sections 37 , 37 .
[0177] Also, in order to separate the friction surfaces of the linings 14 a, 14 b configuring the respective pads 9 a, 9 b from both side surfaces of the rotor 1 (refer to FIG. 11 ) as the braking is released, the respective return springs 16 c, 16 c are provided at both circumferential end portions of the respective pads 9 a, 9 b. Also in the third embodiment, each of the return springs 16 c is configured by an inner spring element 26 c and an outer spring element 26 d, which are separate elements. As shown in FIG. 18 , each of the spring elements 26 c, 26 d is a torsion coil spring that is formed by bending a wire rod of stainless spring steel such as piano line and in which base sections of a pair of arm sections 28 c, 28 d (inner arm section 28 c, outer arm section 28 d ) continue from a coil section 27 b provided at an axially central portion of a diametrically outer end-biased part.
[0178] Particularly, in the third embodiment, a diameter of the coil section 27 b is made to be larger than the diameter of the coil section 27 ( 27 a ) configuring the return spring 16 a ( 16 b ) used in the first and second embodiments. Thereby, at a state where the respective return springs 26 c, 26 d are mounted to the respective pad clips 15 b, it is possible to bring the diametrically inner end portions of the respective coil sections 27 b into contact with the diametrically outer surfaces of the respective positioning step sections 36 provided at the diametrically central portions of the respective leg sections 22 a. In the meantime, when implementing the third embodiment, the number of windings of the respective coil sections 27 b is not particularly problematic. As shown in FIG. 18A , the coil section may be wound one time, or as shown in FIG. 18B , the coil section may be wound twice or more. Also, the number of windings of the coil section 27 b may be different between the inner spring element 26 c and the outer spring element 26 d. In this case, preferably, the number of windings of the coil section 27 b configuring the outer spring element 26 d is made to be larger than that of the coil section 27 b configuring the inner spring element 26 c and the wire rod configuring the outer spring element 26 d is made to be thicker than the wire rod configuring the inner spring element 26 c. Thereby, the returning force to be applied to the outer pad 9 b is made to be larger than the returning force to be applied to the inner pad 9 a, without increasing the constant of spring.
[0179] Also, regarding both the arm sections 28 c, 28 d, the leading end portion of the inner arm section 28 c axially extending toward the rotor 1 is circumferentially bent toward the pad clip 15 b (opposite side to the pads 9 a, 9 b ) and thus forms the engaging section 29 a. The engaging sections 29 a are engaged into the respective engaging notches 41 of the connection section 23 a without the rattling. Specifically, the respective engaging sections 29 a are engaged with the respective engaging notches 41 with the elastic urging force being applied toward the diametrically outer side so that the respective engaging sections cannot be axially displaced. Also, the leading end portion of each of the engaging sections 29 a is bent toward the diametrically outer side, thereby forming a deviation preventing piece 40 b. The respective deviation preventing pieces 40 b are engaged on the backside of the connection section 23 a, thereby preventing the respective return springs 16 c from separating from the respective pad clips 15 b.
[0180] The outer arm section 28 d extending toward the opposite side to the rotor 1 has a substantial U shape, when seen from the front, and has a curved section 30 a , an outer diameter-side bent section 42 , an abutting section 31 a, an inner diameter-side bent section 43 , an extension arm section 32 a and a returning section 33 a in order from a base end side toward the leading end portion. The curved section 30 a has a quadrant shape and is bent in a diametrically inner direction as it is directed toward the leading end. Also, the outer diameter-side bent section 42 is circumferentially bent at a substantial right angle from an inner diameter-side end portion of the curved section 30 a toward the opposite side to the pads 9 a, 9 b. Also, the abutting section 31 a is a part that abuts on a surface (inner surface) of each of the constraining sections 24 a, 24 a configuring the respective pad clips 15 b, which surface faces the side surface of the rotor 1 , by the elastic restoring force of each spring element 26 c ( 26 d ), is linear and extends perpendicularly from an inner diameter-side end portion of the outer diameter-side curved section 42 toward the diametrically inner side. Also, the inner diameter-side bent section 43 is bent from an inner diameter-side end portion of the abutting section 31 a toward the respective pads 9 a , 9 b in the circumferential direction and toward the rotor 1 in the axial direction. By this configuration, the abutting section 31 a is provided (offset) at the opposite side to the pads 9 a, 9 b in the circumferential direction than the inner surfaces (surfaces circumferentially facing the circumferential end surfaces of the engaging protruding pieces 21 , 21 ) of the respective torque receiving sections 37 , 37 .
[0181] Also, the extension arm section 32 a is linear, extends from the leading end portion of the inner diameter-side bent section 43 in the direction coming close to the rotor 1 and is oriented in substantially parallel with the central axis of the rotor 1 . Therefore, also in the third embodiment, in order to prevent the extension arm section 32 a and an circumferential end edge of each of the pressure plates 10 a, 10 b from interfering with each other, the engaging protruding pieces 21 , 21 of the respective pressure plates 10 a, 10 b are provided at the circumferential end edges with the recesses 34 ( 34 a ). An axially central portion of the extension arm section 32 a is axially inserted into each recess 34 ( 34 a ). Also, the returning section 33 a is bent from the leading end portion of the extension arm section 32 a in a direction (opposite side to the engaging section 29 a ) circumferentially separating from the pad clip 15 a and is contacted on the inner surface of each of the engaging protruding pieces 21 , 21 . Also, the diametrical position of the returning section 33 a is the substantially same as the diametrical position of the friction center of each of the linings 14 a, 14 b configuring the respective pads 9 a, 9 b.
[0182] In the third embodiment having the pad clips 15 b and the return springs 16 c , when assembling the floating disc brake, the return springs 16 c are mounted (preset) to the pad clips 15 b, as shown in FIGS. 16 and 17 , at a state before the respective pads 9 a, 9 b are mounted to the support 3 . That is, as shown in FIGS. 16 and 17 , an assembly of the pad clip 15 b and the return spring 16 c (inner spring element 26 c and outer spring element 26 d ) is configured. To this end, for example, at a state where the engaging sections 29 a provided at the leading end portions of the inner arm sections 28 c configuring the respective spring elements 26 c, 26 d are inserted (engaged) into the engaging notches 41 of the connection section 23 a, the outer arm sections 28 d are elastically deformed in the approaching direction toward the inner arm sections 28 c and then the outer arm sections 28 d are elastically returned (the elastic deformation is released). Thereby, the engaging section 29 is engaged into the engaging notch 41 with the elastic urging force being applied in the diametrically outer side so that the respective engaging sections cannot be axially displaced, and the abutting section 31 a is enabled to abut on the inner surface of the constraining section 24 a with the elastic urging force being axially applied in the direction separating from the rotor 1 . Also, at this state, the inner diameter-side end portion of the coil section 27 b is elastically pressed to the outer diameter-side surface of each positioning step section 36 toward the diametrical inner side. As a result, in the third embodiment, both the spring elements 26 c, 26 d (return spring 16 c ) are mounted to the pad clip 15 b with being positioned in the diametrical and axial directions (an assembly of the pad clip 15 b and the return spring 16 c is configured). Also, in the third embodiment, since the deviation preventing pieces 40 b and the abutting sections 31 a of both the spring elements 26 c, 26 d are arranged on the backside of the pad clip 15 b and the remaining sections are arranged on the front face side, both the spring elements 26 c, 26 d are circumferentially positioned with respect to the pad clip 15 b.
[0183] After the return springs 16 c are mounted to the pad clips 15 b as described above, the assemblies of the pad clips 15 b and the return springs 16 c are mounted to the support 3 (refer to FIGS. 13 to 15 ) and then both the pads 9 a, 9 b are mounted to the support 3 , as shown in FIGS. 10 to 12 . Also, at the state where both the pads 9 a , 9 b are mounted to the support 3 , the elastic urging force from the return springs 16 c is not applied to both the pads 9 a, 9 b yet.
[0184] Also in the floating disc brake of the third embodiment having the above configuration and assembled as described above, when mounting the respective pad clips 15 b, it is possible to handle the respective pad clips 15 b and the return springs 16 c as integral articles (assemblies, subassemblies), like the first and second embodiments. Therefore, it is possible to perform the operations of mounting the respective pad clips 15 a and the respective return springs 16 a at the same time, thereby facilitating the mounting operation. As a result, it is possible to improve the assembling performance, thereby reducing the assembling cost. Also, at a state just after both the pads 9 a, 9 b are mounted (the caliper is not mounted yet), the elastic urging force is not applied to both the pads 9 a, 9 b. Thus, it is not necessary to consider a configuration of preventing both the pads 9 a, 9 b from separating axially from the support 3 . Accordingly, the assembling operation or conveying operation is not troublesome. Also, since it is possible to handle the respective pad clips 15 a and the respective return springs 16 a as integral articles (assemblies), it is possible to reduce the part management cost.
[0185] Also, in the third embodiment, the respective spring elements 26 c, 26 d are positioned in the axial, diametrical and circumferential directions with the respective return springs 16 c being mounted to the respective pad clips 15 b. Therefore, it is possible to stabilize the postures (shapes) of the respective spring elements 26 c, 26 d . Therefore, it is possible to effectively prevent the respective return springs 16 c (spring elements 26 c, 26 d ) from separating from the respective pad clips 15 a or the mounting positions from deviating. As a result, it is possible to improve the operability of the mounting operation of the respective pad clips 15 a and the respective return springs 16 a to the support 3 . Also, it is possible to apply the stable returning force to the respective pads 9 a, 9 b by the respective return springs 16 c.
[0186] Also, the respective constraining sections 24 a, 24 a and the respective abutting sections 31 a, 31 a are circumferentially offset toward the opposite side to the pads 9 a, 9 b than the inner surfaces of the respective torque receiving sections 37 , 37 (surfaces facing the circumferential end surfaces of the engaging protruding pieces 21 , 21 ). Therefore, it is possible to perform the mounting operation of both the pads 9 a , 9 b just by parallel moving both the pads 9 a, 9 b in the axial direction. Thus, the mounting operation is easy, so that it is possible to improve the operation efficiency. The other configurations and operational effects are the same as those of the first embodiment.
Fourth Embodiment
[0187] FIGS. 19 to 23 show a fourth embodiment of the invention. The features of the fourth embodiment are that the support structure of a return spring 16 d to a pad clip 15 c is different from the first to third embodiments. Since the basic structures of the pad clip 15 c and the return spring 16 d are the substantially same as those of the first embodiment, the description of the common parts are omitted or simplified. Hereinafter, the features of the fourth embodiment are described.
[0188] Also in the fourth embodiment, each pad clip 15 c is configured by connecting diametrically outer end portions of a pair of axially spaced leg sections 22 b, 22 b by a connection section 23 b. Particularly, in the fourth embodiment, the respective leg sections 22 b, 22 b are provided at the diametrically outer end portions with folding sections 44 , 44 for supporting the coil sections 27 c, 27 c configuring the return spring 16 d. Specifically, the folding sections 44 , 44 are formed by circumferentially folding a diametrically central portion into a substantial U shape toward the pads 9 a, 9 b with being bent at a substantial right angle from the diametrically outer surfaces of the positioning step sections 36 , 36 in the diametrically outer side. In the meantime, a diametrical size between the diametrically inner surfaces of the folding sections 44 , 44 and the diametrically outer surfaces of the positioning step sections 36 , 36 is slightly larger than a diameter of each coil section 27 c. Also, a gap between both side surfaces of each of the folding sections 44 , 44 , which side surfaces face each other in the circumferential direction, is slightly larger than a thickness of each coil section 27 c.
[0189] Also in the fourth embodiment, a pair of constraining sections 24 b, 24 b is provided at both axial end portions of each of the pad clips 15 c. Particularly, in the fourth embodiment, each of the constraining sections 24 b, 24 b is formed by bending a leading end portion (end portion at the opposite rotor-side) toward the opposite side to the pads 9 a, 9 b in the circumferential direction with extending from a part biased to the diametrically outer surface of each of the positioning step sections 36 , 36 and the diametrically inner end side of each of the folding sections 44 , 44 toward the opposite side to the rotor in the axial direction. Also in the fourth embodiment, the respective constraining sections 24 b, 24 b are offset toward the opposite side to the pads 9 a, 9 b in the circumferential direction than the inner surfaces (surfaces facing the circumferential end surfaces of the engaging protruding pieces 21 , 21 ) of the torque receiving sections 37 , 37 .
[0190] Also, in the fourth embodiment, the diametrically outer surfaces of the positioning step sections 36 , 36 configuring the respective leg sections 22 b, 22 b are formed with engaging holes 45 , 45 for engaging parts (leading end portions of inner arm sections 28 e of spring elements 26 e, 26 f ) of the return springs 16 d, with penetrating in the diametrical direction.
[0191] Also, in order to separate the friction surfaces of the linings 14 a, 14 a configuring the pads 9 a, 9 b from both side surfaces of the rotor 1 (refer to FIG. 20 ) as the braking is released, the respective return springs 16 d, 16 d are provided at both circumferential end portions of the respective pads 9 a, 9 b. Each of the return springs 16 d, 16 d is composed of an inner spring element 26 e and an outer spring element 26 f , which are separate elements. As shown in FIG. 23 , each of the spring elements 26 e , 26 f is a torsion coil spring that is formed by bending a wire rod of stainless spring steel such as piano line and in which base sections of a pair of arm sections 28 e, 28 f continue from a coil section 27 c provided at an axially central portion of a diametrically outer end side-biased part.
[0192] Particularly, in the fourth embodiment, each coil section 27 c is mounted to a part surrounded by the diametrically outer surface of each abutting step section 36 and each folding section 44 without the rattling. Also, of both the arm sections 28 e , 28 f, the leading end portion of the inner arm section 28 e extending toward the rotor 1 in the axial direction and toward the inner side in the circumferential direction is bent toward the rotor 1 , thereby configuring an engaging section 46 . The respective engaging sections 46 are engaged in the engaging holes 45 formed at the positioning step sections 36 from the diametrically outer side. Also, at this state, the leading end-biased part of each inner arm section 28 e is abutted in an opening of each engaging hole 45 with the elastic urging force being axially applied toward the rotor 1 .
[0193] Also, the outer arm section 28 f extending to the opposite side to the rotor 1 has a substantial L shape, when seen from the front, and has a base end portion 47 , a curved section 48 , an extension arm section 32 b and a returning section 33 b in order from a base end side toward the leading end portion. The base end portion 47 has an abutting section 31 b at its diametrically central portion and is linear. Also, the abutting section 31 b is a part that abuts on a side edge (inner side edge) of the constraining section 24 b, 24 b configuring the pad clip 15 c, which edge faces the side surface of the rotor 1 , with the elastic urging force axially applied to the opposite side to the rotor 1 , by the elastic restoring force of each of the spring elements 26 e, 26 f (coil sections 27 c, 27 c ). Also, the bent section 48 is bent from the inner diameter-side end portion of the base end portion 47 toward the respective pads 9 a , 9 b in the circumferential direction and toward the rotor 1 in the axial direction.
[0194] Also, the extension arm section 32 b is linear, extends from the leading end portion of the bent section 48 in the direction coming close to the rotor 1 and is oriented in substantially parallel with the central axis of the rotor 1 . Therefore, also in the fourth embodiment, in order to prevent the extension arm section 32 b and the circumferential end edge of each of the pressure plates 10 a, 10 b from interfering with each other, the engaging protruding pieces 21 , 21 of the respective pressure plates 10 a, 10 b are provided at the circumferential end edges thereof with the recesses 34 ( 34 a ). An axially central portion of the extension arm section 32 b is axially inserted into each recess 34 ( 34 a ). Also, the returning section 33 b is bent from the leading end portion of the extension arm section 32 b in a direction circumferentially separating from each pad clip 15 a and is contacted on the inner surface of each of the engaging protruding pieces 21 , 21 . Also, the diametrical position of the returning section 33 b is the substantially same as the diametrical position of the friction center of each of the linings 14 a, 14 b configuring the respective pads 9 a, 9 b.
[0195] In the fourth embodiment having the pad clips 15 c and the return springs 16 d , when assembling the floating disc brake, the return spring 16 d is mounted (preset) to the pad clip 15 c, as shown in FIG. 22 , at a state before the respective pads 9 a, 9 b are mounted to the support 3 . That is, as shown in FIG. 22 , an assembly of the pad clip 15 c and the return spring 16 d (inner spring element 26 e and outer spring element 26 f ) is configured. To this end, for example, the coil sections 27 c configuring the respective spring elements 26 e, 26 f are mounted to the parts surrounded by the diametrically outer surfaces of the respective positioning step sections 36 and the respective folding sections 44 . Then, at a state where the engaging sections 46 provided at the leading end portions of the inner arm sections 28 e are engaged into the engaging holes 45 formed on the diametrically outer surfaces of the positioning step sections 36 , the outer arm sections 28 f are elastically deformed in the approaching direction toward the inner arm sections 28 e and then the outer arm sections 28 f are elastically returned (the elastic deformation is released). Thereby, the leading end side biased parts of the inner arm sections 28 e are abutted in the openings of the respective engaging holes 45 with the elastic urging force being axially applied toward the rotor 1 -side, and the abutting sections 31 a are enabled to abut on the side edges of the constraining sections 24 b with the elastic urging force being axially applied in the direction separating from the rotor 1 and toward the diametrically outer side. As a result, in the fourth embodiment, both the spring elements 26 e, 26 f (return spring 16 d ) are mounted to the pad clip 15 c with being positioned in the diametrical, circumferential and axial directions (an assembly of the pad clip 15 c and the return spring 16 d is configured).
[0196] After the return springs 16 d are mounted to the pad clips 15 c as described above, the assemblies of the pad clips 15 c and the return springs 16 d are mounted to the support 3 and then both the pads 9 a, 9 b are mounted to the support 3 , as shown in FIGS. 19 to 21 . Also in the fourth embodiment, at the state where both the pads 9 a , 9 b are mounted to the support 3 , the elastic urging force from the return springs 16 d is not applied to both the pads 9 a, 9 b yet.
[0197] Also in the floating disc brake of the fourth embodiment having the above configuration and assembled as described above, when mounting the respective pad clips 15 b, it is possible to handle the respective pad clips 15 b and the return springs 16 c as integral articles (assemblies, subassemblies), like the first to third embodiments. Therefore, it is possible to perform the operations of mounting the respective pad clips 15 a and the respective return springs 16 a at the same time, thereby facilitating the mounting operation. As a result, it is possible to improve the assembling performance, thereby reducing the assembling cost. Also, at a state just after both the pads 9 a, 9 b are mounted (the caliper is not mounted yet), the elastic urging force is not applied to both the pads 9 a, 9 b yet. Thus, it is not necessary to consider a configuration of preventing both the pads 9 a, 9 b from separating axially from the support 3 . Accordingly, the assembling operation or conveying operation is not troublesome. Also, since it is possible to handle the respective pad clips 15 a and the respective return springs 16 a as integral articles (assemblies), it is possible to reduce the part management cost.
[0198] Also, in the fourth embodiment, the respective spring elements 26 e, 26 f are positioned in the axial, circumferential and diametrical directions with the respective return springs 16 d being mounted to the respective pad clips 15 c. Therefore, it is possible to stabilize the postures (shapes) of the respective spring elements 26 e, 26 f . Therefore, it is possible to effectively prevent the respective return springs 16 d (spring elements 26 e, 26 f ) from separating from the respective pad clips 15 c or the mounting positions from deviating. As a result, it is possible to improve the operability of the mounting operation of the respective pad clips 15 c and the respective return springs 16 d to the support 3 . Also, it is possible to apply the stable returning force to the respective pads 9 a, 9 b by the respective return springs 16 d with being mounted to the support 3 as described above. Also, in the pad clips 15 c of the fourth embodiment, since the respective constraining sections 24 c, 24 c are provided at the diametrically outer surface parts of the positioning step sections 36 , 36 , it is possible to reduce the material cost, compared to the pad clips 15 ( 15 a, 15 b ) of the first to third embodiments. That is, in the pad clips 15 ( 15 a, 15 b ) of the first to third embodiments, the constraining sections 24 , 24 a are provided to axially extend from the torque receiving sections 36 in the direction getting away from each other, so that the amount of the extension is larger than that of the fourth embodiment. Therefore, the width size of the pad clip 15 ( 15 a, 15 b ) upon the developing before bending the respective constraining sections 24 , 24 a is increased. Compared to this, in the pad clip 15 c of the fourth embodiment, since it is possible to reduce the width size upon the developing, it is possible to suppress the material cost. The other configurations and operational effects are the same as those of the first and third embodiments.
Fifth Embodiment
[0199] FIGS. 24 to 26 show a fifth embodiment of the invention. The features of the fifth embodiment relate to the shape of the pad clip 15 c of the fourth embodiment.
[0200] That is, a pad clip 15 d of the fifth embodiment has a shape in which the connection section 23 b is omitted from the pad clip 15 c of the fourth embodiment and is configured by an inner clip element 49 a and an outer clip element 49 b, which are separate elements and have the leg sections 22 b, 22 b, respectively.
[0201] In the fifth embodiment having the pad clip 15 d, when assembling the floating disc brake, as shown in FIGS. 25 and 26 , the inner spring element 26 e and the outer spring element 26 f configuring the return spring 16 d are mounted (preset) to the inner clip element 49 a and the outer clip element 49 b, respectively. That is, an assembly of the pad clip 15 d (inner clip element 49 a and outer clip element 49 b ) and the return spring 16 d (inner spring element 26 e and outer spring element 26 f ) is configured. Then, as shown in FIG. 24 , an inner assembly 50 a configured by the inner clip element 49 a and the inner spring element 26 e and an outer assembly 50 b configured by the outer clip element 49 b and the outer spring element 26 f are mounted to the support 3 separately (or at the same time).
[0202] In the fifth embodiment having the above configuration, like the fourth embodiment, it is possible to make the pad clip 15 d (inner and outer clip elements 49 a , 49 b ) smaller/lighter, compared to the configuration where the pad clip 15 c is integrally formed. Therefore, it is possible to improve the handling property of each pad clip 15 d, thereby improving the mounting operability of the respective pad clips 15 d. Also, it is possible to reduce the material cost for forming the respective pad clips 15 d.
[0203] The other configurations and operational effects are the same as those of the first and fourth embodiments.
Sixth Embodiment
[0204] FIGS. 27 to 37 show a sixth embodiment of the invention. Also in the sixth embodiment, a pair of return springs 16 d, 16 e that is provided at the rotation input side and the rotation output side is respectively configured by an inner spring element 26 g and an outer spring element 26 h. Also, each of a pair of leg sections 22 c, 22 c , which is provided to each of a pair of pad clips 15 e, 15 mounted to the rotation input side and the rotation output side of the support 3 , is provided at a diametrically central portion thereof with a positioning step section 36 a, 36 a having a substantially U-shaped section and circumferentially protruding toward each of the inner and outer pads 9 a, 9 b. The positioning step sections 36 a, 36 a are elastically fitted to outer sides of protrusion sections 39 a, 39 a formed at both circumferential end portions of an inner surface of a maintaining section that is provided to the support 3 , with a diametrically outer side thereof being opened, so as to maintain parts of the support 3 , i.e., the respective pads 9 a, 9 b. The protrusion sections 39 a, 39 a are held from both diametrical sides thereof by the respective positioning step sections 36 a, 36 a, so that the respective pad clips 15 e, 15 e are diametrically positioned.
[0205] Particularly, in the structure of the sixth embodiment, the respective protrusion sections 39 a, 39 a are held over the entire width thereof by the respective positioning step sections 36 a, 36 a. That is, in the fourth and fifth embodiments, the positioning step section 36 holds the protruding section 39 (refer to FIG. 24 ) by a pressing piece 51 (refer to FIGS. 24 and 26C ) folded over only a part of the positioning step section 36 in the width direction. Thus, it may not be said that the support rigidity of the respective pad clips 15 c, 15 d to the support 3 is sufficient. Particularly, in the fifth embodiment shown in FIGS. 24 to 26 , when the pad clip is divided into the inner and outer clip elements 49 a, 49 b, the rigidity of the inner and outer spring elements 26 e , 26 f (refer to FIGS. 19 to 26 ) may be insufficient in the applying direction of the elastic urging force of the respective spring elements 26 e, 26 f. However, in the sixth embodiment, since the respective positioning step sections 36 a, 36 a holds the respective protrusion sections 39 a, 39 a over the entire width (the respective sections 36 a, 36 a contact over the entire width in the width direction with the sufficient high surface pressure), it is possible to sufficiently secure the rigidity.
[0206] Also, in the sixth embodiment, a protruding amount of each of the positioning step sections 36 a, 36 a in the circumferential direction is made to be larger than that of each of the protrusion sections 39 a, 39 a, so that a gap 52 (refer to FIG. 35 ) is formed between an inner surface of the leading end portion of each positioning step section 36 a, 36 a and a leading end surface of each protrusion section 39 a, 39 a. Engaging sections 46 a, 46 a, which are provided at one end portions of the inner spring element 26 g and the outer spring element 26 h configuring both the return springs 16 e, 16 e , are inserted into engaging holes 45 a, 45 a that are formed at the leading end portions of the respective positioning step sections 36 a, 36 a, which leading end portions are formed at parts more protruding the leading end surfaces of the respective protrusion sections 39 a, 39 a.
[0207] In the structure of the sixth embodiment, by the above configuration, the mounting positions of the respective engaging sections 46 a, 46 a are made to come close to the circumferential central portion of the support 3 , and in the circumferential direction, positions at which returning sections 33 c, 33 c provided at the other end portions of the respective spring elements 26 g, 26 h and the pressure plates 10 a, 10 b of the inner and outer pads 9 a, 9 b contact each other and positions of the respective engaging sections 46 a, 46 a are substantially matched. That is, the respective returning sections 33 c, 33 c and the respective pressure plates 10 a, 10 b contact each other within a length range (length range between the dashed-dotted line α and the dashed-dotted line β shown in FIGS. 34 and 35 ) in the circumferential direction. In the sixth embodiment, the circumferential positions of the respective engaging sections 46 a, 46 a (the dashed-dotted line γ shown in FIGS. 34 and 35 ) are within the length range. That is, as shown in FIGS. 34 and 35 , the dashed-dotted line γ lies between the dashed-dotted line α and the dashed-dotted line β. Therefore, even when the respective spring elements 26 g, 26 h are elastically deformed in the direction along which the returning sections 33 c, 33 c provided at both end portions thereof and the engaging sections 46 a, 46 a are made to come close to each other, as the respective pads 9 a, 9 b are mounted to the support 3 , the moment of a direction rotating about the diametrical axis of the rotor is not caused in the respective spring elements 26 g, 26 h . Hence, it is possible to prevent the respective spring elements 26 g, 26 h from inadvertently separating from the pad clip 15 e.
[0208] Also, in the sixth embodiment, the direction along which the respective returning sections 33 c, 33 c press the respective pressure plates 10 a, 10 a and the direction along which the respective engaging sections 46 a, 46 a press the pad clips 15 e are the substantially axial direction and are the opposite directions each other. Therefore, it is possible to effectively transfer the elastic urging force of the respective spring elements 26 g, 26 h to both the pads 9 a, 9 b, as the force separating both the pads 9 a, 9 b. Thus, even though a thick wire rod, particularly a member having high elastic urging force is not used as the respective spring elements 26 g, 26 h, it is possible to securely separate both the pads 9 a, 9 b. Accordingly, it is possible to suppress the processing cost of the respective spring elements 26 g, 26 h and to facilitate the mounting operation of the respective spring elements 26 g, 26 h.
[0209] Also, in the sixth embodiment, the pad clip 15 e is formed at both axial end portions, which are diametrically outer end portions, with folding sections 53 , 53 having a substantially U-shaped section, which are opened in the diametrically outer side. The coil sections 27 c, 27 c configuring the respective spring elements 26 g, 26 h are latched to the respective folding sections 53 , 53 (the folding section 53 is inserted into the coil section 27 c ). In the sixth embodiment, since the insertion direction of the engaging sections 46 a, 46 a into the respective engaging holes 45 a, 45 a and the latching direction of the respective coil sections 27 c, 27 c to the respective folding sections 53 , 53 are the same, it is possible to facilitate the mounting operation of the respective spring elements 26 g, 26 h. In the meantime, the leading end portions of the respective folding sections 53 , 53 are provided with curved sections, so that a width size of an opening end portion of each folding section 53 , 53 is made to be smaller than that of each coil section 27 c, 27 c. Therefore, at a state where the respective coil sections 27 c, 27 c are latched to the respective folding sections 53 , 53 , the respective coil sections 27 c, 27 c are not inadvertently separated from the respective folding sections 53 , 53 .
[0210] Also, in the sixth embodiment, the hook-shaped constraining sections 24 c , 24 c having an opened lower part are provided at both axial end portions of the pad clip 15 e, which are diametrically outer end portions (shoulder sections of the pad clip 15 e ). The leading end portions (diametrically inner half portions, lower parts in FIGS. 30 to 33 ) of the respective constraining sections 24 c, 24 c are circumferentially bent in the direction coming close to the pads 9 a, 9 b. Also, the parts of the respective spring elements 26 g, 26 h between the respective coil sections 27 c, 27 c and the respective returning sections 33 c, 33 c are provided with a base end side linear section 54 having an abutting section 59 at a base end side part thereof, a curved section 30 b and an extension arm section 32 c in order from the respective coil sections 27 c, 27 c. As shown in FIG. 37 , at a state where the respective return springs 16 e (spring elements 26 g, 26 h ) are mounted to the respective pad clips 15 e to thus configure the assemblies of the respective pad clips 15 e and the respective return springs 16 e, the abutting sections 59 , 59 of the respective spring elements 26 g, 26 h are abutted on the respective constraining sections 24 c, 24 c. Also, at a state before both the pads 9 a , 9 b are mounted after the pad clips 15 e and the respective spring elements 26 g, 26 h (assemblies of the pad clips 15 e and the return springs 16 e ) are mounted to the support 3 , the abutting sections 59 , 59 of the respective spring elements 26 g, 26 h are engaged (abutted) to the respective constraining sections 24 c, 24 c, as shown with the solid line in FIGS. 31 and 33 .
[0211] At a state where the abutting sections 59 , 59 are engaged to the respective constraining sections 24 c, 24 c, the respective constraining sections 24 c, 24 c prevent the respective returning sections 33 c, 33 c from displacing in the direction getting away from each other more than the state shown in FIGS. 31 and 37 and both the constraining sections 24 c, 24 c hold the respective abutting sections 59 , 59 . The constraining sections prevent parts of the respective spring elements 26 g, 26 h except for the returning sections 33 c, 33 c from being inclined to protrude toward the center of the support 3 in the circumferential direction of the rotor. At this state, when axially translating and mounting both the pads 9 a, 9 b to the support 3 , the respective spring elements 26 g, 26 h do not interfere with each other, so that it is possible to facilitate the mounting operation. In order to mount both the pads 9 a, 9 b to the support 3 , as shown in FIGS. 34 to 36 , the bent sections 38 of the pad clip 15 e are elastically deformed in a crushing direction by the circumferential end portions (engaging protruding pieces 21 ) of both the pads 9 a, 9 b, as shown in FIGS. 34 to 36 , and the circumferential end portions are pushed in the torque receiving sections 37 of the pad clip 15 e.
[0212] In correspondence to the pushing-in operation, while both the circumferential end portions of the pressure plate 10 a, 10 b of both the pads 9 a, 9 b elastically deform the respective returning sections 33 c, 33 c from a state shown in FIG. 31 to a state shown in FIG. 32 and from a state shown with the solid line to a state shown with the dashed-two dotted line in FIG. 33 , the pads are mounted to the support 3 . In the meantime, the shape of the return spring 16 e shown in FIGS. 29 and 30 indicates the state where the respective pads 9 a, 9 b (and caliper 2 ) are elastically deformed and mounted to the support 3 .
[0213] The other configurations and operational effects are the same as those of the first embodiment.
Seventh Embodiment
[0214] FIGS. 38 to 43 show a seventh embodiment. In the meantime, the shape of the return spring 16 e (inner spring element 26 g, outer spring element 26 h ) shown in FIGS. 38 to 43 indicates a state where the pads 9 a, 9 b (refer to FIGS. 1 to 3 , for example) are elastically deformed and mounted to the support 3 . In the seventh embodiment, a pad clip 15 f is used in which the connection section 23 c is omitted from the pad clip 15 e of the sixth embodiment. Specifically, the pad clip 15 f is configured by an inner clip element 49 c and an outer clip element 49 d, which have the leg sections 22 c, 22 c, respectively, and are separate elements.
[0215] In the seventh embodiment having the pad clip 15 f, at a state before the respective pads 9 a, 9 b are mounted to the support 3 , the inner spring element 26 g and the outer spring element 26 h configuring the return spring 16 e are respectively mounted (preset) to the inner clip element 49 c and the outer clip element 49 d, as shown in FIG. 43 . That is, an assembly of the pad clip 15 f (inner clip element 49 c and outer clip element 49 d ) and the return spring 16 e (inner spring element 26 g and outer spring element 26 h ) is configured. Then, an inner assembly 50 c configured by the inner clip element 49 c and the inner spring element 26 g and an outer assembly 50 d configured by the outer clip element 49 d and the outer spring element 26 h are mounted to the support 3 separately (or at the same time).
[0216] In the seventh embodiment having the above configuration, like the sixth embodiment, it is possible to make the pad clip 15 f (inner and outer clip elements 49 c , 49 d ) smaller/lighter, compared to the configuration where the pad clip 15 e is integrally formed. Therefore, it is possible to improve the handling property of each pad clip 15 f, thereby improving the mounting operability of the respective pad clips 15 f. Also, it is possible to reduce the material cost for forming the respective pad clips 15 f.
[0217] The other configurations and operational effects are the same as those of the first and sixth embodiments.
Eighth Embodiment
[0218] FIGS. 44 to 49 show an eighth embodiment. In the meantime, the shape of the return spring 16 e (inner spring element 26 g, outer spring element 26 h ) shown in FIGS. 44 to 49 also indicates the state where the pads 9 a, 9 b (refer to FIGS. 1 to 3 , for example) are elastically deformed and mounted to the support 3 . In the eighth embodiment, a pad clip 15 g is used in which the constraining sections 24 c, 24 c of the pad clip 15 e of the sixth embodiment are replaced with the constraining sections 24 , 24 of the pad clip 15 a of the first embodiment. That is, the constraining sections 24 , 24 of the pad clip 15 g of the eighth embodiment are respectively formed by bending a central portion of the torque receiving section toward each of the pads 9 a, 9 b in the circumferential direction with extending in a direction axially separating from each of the torque receiving sections 37 , 37 provided at the inner-diametrically biased parts of the leg sections 22 , 22 .
[0219] Also in the eighth embodiment having the pad clip 15 g, when assembling the floating disc brake, the inner spring element 26 g and the outer spring element 26 h configuring the return spring 16 e are respectively mounted (preset) to the pad clip 15 g , as shown in FIG. 49 . That is, an assembly of the pad clip 15 g and the return spring 16 e (inner spring element 26 g and outer spring element 26 h ) is configured. Then, as shown in FIGS. 44 , 45 and the like, the assembly of the pad clip 15 g and the return spring 16 e is mounted to the support 3 .
[0220] The other configurations and operational effects are the same as those of the first and sixth embodiments.
Ninth Embodiment
[0221] FIGS. 50 to 56 show a ninth embodiment. In the meantime, the shape of the return spring 16 e (inner spring element 26 g, outer spring element 26 h ) shown in FIGS. 50 to 56 also indicates the state where the pads 9 a, 9 b (refer to FIGS. 1 to 3 , for example) are elastically deformed and mounted to the support 3 . In the ninth embodiment, a pad clip 15 h is used in which the connection section 23 c is omitted from the pad clip 15 g of the eighth embodiment. Specifically, the pad clip 15 h is configured by an inner clip element 49 e and an outer clip element 49 f, which have the leg sections 22 d, 22 d, respectively, and are separate elements.
[0222] In the ninth embodiment having the pad clip 15 h, at a state before the respective pads 9 a, 9 b are mounted to the support 3 , the inner spring element 26 g and the outer spring element 26 h configuring the return spring 16 e are respectively mounted (preset) to the inner clip element 49 e and the outer clip element 49 f, as shown in FIG. 56 . That is, an assembly of the pad clip 15 h (inner clip element 49 e and outer clip element 49 f ) and the return spring 16 e (inner spring element 26 g and outer spring element 26 h ) is configured. Then, an inner assembly 50 e configured by the inner clip element 49 e and the inner spring element 26 g and an outer assembly 50 f configured by the outer clip element 49 f and the outer spring element 26 h are mounted to the support 3 separately (or at the same time).
[0223] In the ninth embodiment having the above configuration, like the eighth embodiment, it is possible to make the pad clip 15 h (inner and outer clip elements 49 e , 49 f ) smaller/lighter, compared to the configuration where the pad clip 15 g is integrally formed. Therefore, it is possible to improve the handling property of each pad clip 15 h, thereby improving the mounting operability of the respective pad clips 15 h. Also, it is possible to reduce the material cost for forming the respective pad clips 15 h.
[0224] The other configurations and operational effects are the same as those of the first and eighth embodiments.
[0225] Although the invention has been specifically described with reference to the specific embodiments, it is obvious to one skilled in the art that a variety of changed and modifications can be made without departing from the spirit and scope of the invention.
[0226] This application is based on Japanese Patent Application Nos. 2010-090770 filed on Apr. 9, 2010, 2010-226785 filed on Oct. 6, 2012 and 2011-055045 filed on Mar. 14, 2011, the disclosures of which are incorporated herein by way of reference.
INDUSTRIAL APPLICABILITY
[0227] In the respective embodiments, the mounting method of mounting the return spring to the pad clip (the assembly of the pad clip and the return spring is configured) and then mounting the pad clip and the return spring to the support at the same time has been described. However, when implementing the invention, a mounting method of mounting the pad clip unitary body to the support and then mounting the return spring to the pad clip may be also implemented.
[0228] In the respective embodiments, the leg sections configuring the pad clip are respectively arranged between the support and the inner and outer pads, and when the braking is released, both the pads are separated from the rotor by using the elastic urging force of the return spring. However, the invention is not limited thereto. That is, the leg section configuring the pad clip may be arranged between the support and only one pad, and only the one pad may be separated from the rotor by using the elastic urging force of the return spring. When such configuration is adopted, only the assembly consisting of the inner clip element (or outer clip element) and the inner spring element (or outer spring element) is mounted to the support. The mounting position of the assembly having the elements can be freely selected, such as inner side, outer side, anchor side and opposite side to the anchor. Also, regarding the assemblies to be mounted at inner side, outer side, anchor side and opposite side to the anchor, it is possible to mount the assemblies having different configurations.
REFERENCE SIGNS LIST
[0229] 1 : rotor
[0230] 2 : caliper
[0231] 3 : support
[0232] 4 : guide pin
[0233] 5 : guide hole
[0234] 6 : boots
[0235] 7 : rotation input side engaging section
[0236] 8 : rotation output side engaging section
[0237] 9 a, 9 b : pad
[0238] 10 a, 10 b : pressure plate
[0239] 11 : cylinder section
[0240] 12 : claw section
[0241] 13 : piston
[0242] 14 a, 14 b : lining
[0243] 15 , 15 a to 15 h : pad clip
[0244] 16 , 16 a to 16 e : return spring
[0245] 17 , 17 a, 17 b : coil section
[0246] 18 : engaging hole
[0247] 19 : protruding piece
[0248] 20 : engaging recess
[0249] 21 : engaging protruding piece
[0250] 22 , 22 a, 22 b, 22 c, 22 d : leg section
[0251] 23 , 23 a, 23 b, 23 c : connection section
[0252] 24 , 24 a, 24 b, 24 c : constraining section
[0253] 25 : protruding piece
[0254] 26 a, 26 c, 26 e, 26 g : inner spring element
[0255] 26 b, 26 d, 26 f, 26 h : outer spring element
[0256] 27 , 27 a, 27 b, 27 c : coil section
[0257] 28 a, 28 c, 28 e : inner arm section
[0258] 28 b, 28 d, 28 f : outer arm section
[0259] 29 , 29 a : engaging section
[0260] 30 , 30 a, 30 b : curved section
[0261] 31 , 31 a, 31 b : abutting section
[0262] 32 , 32 a, 32 b, 32 c : extension arm section
[0263] 33 , 33 a, 33 b, 33 c : returning section
[0264] 34 , 34 a : recess
[0265] 35 : connection arm section
[0266] 36 , 36 a : positioning step section
[0267] 37 : torque receiving section
[0268] 38 : bent section
[0269] 39 , 39 a : protrusion section
[0270] 40 , 40 a, 40 b : deviation preventing section
[0271] 41 : engaging notch
[0272] 42 : outer diameter-side bent section
[0273] 43 : inner diameter-side bent section
[0274] 44 : folding section
[0275] 45 , 45 a : engaging hole
[0276] 46 , 46 a : engaging section
[0277] 47 : base end portion
[0278] 48 : bent section
[0279] 49 a, 49 c, 49 e : inner clip element
[0280] 49 b, 49 d, 49 f : outer clip element
[0281] 50 a, 50 c : inner assembly
[0282] 50 b, 50 d : outer assembly
[0283] 51 : pressing piece
[0284] 52 : gap
[0285] 53 : folding section
[0286] 54 : based end side linear section
[0287] 55 : coil section
[0288] 56 : return spring
[0289] 57 : anti-rattle spring
[0290] 58 : pressing section
[0291] 59 : abutting section
|
Disclosed is a structure such that when pad clips are to be mounted, it is possible to handle return springs and the pad clips as integral articles, thereby facilitating mounting work. Constraining sections are provided at both axial ends of each of the pad clips. Furthermore, the return springs are composed of inner spring elements and outer spring elements. These two types of spring elements are helical torsion springs provided with helical sections. Abutting sections are provided on the spring elements, respectively. The abutting sections are pressed against the inner surfaces of the constraining sections by elastic restoring forces. Moreover, the central axes of the coil sections are substantially oriented in the rotational direction of the rotor.
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CROSS-REFERENCE
This application is a continuation of U.S. patent application Ser. No. 10/767,730 filed on Jan. 30, 2004, (now U.S. Pat. No. 7,272,612 issued on Sep. 18, 2007), which is a continuation of U.S. patent application Ser. No. 09/671,304 filed on Sep. 28, 2000 (now U.S. Pat. No. 6,741,983 issued on May 25, 2004), which claims the benefit of priority from U.S. Provisional Application No. 60/156,452 filed on Sep. 28, 1999. The disclosure of each of the foregoing applications is hereby incorporated by reference into the present application in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
The U.S. Government retains certain rights in this invention due to funding provided by contract J-FBI-98-083 awarded by the Federal Bureau of Investigation.
TECHNICAL FIELD OF THE INVENTION
The invention is related to the area of computer software for the management of databases. In particular it is related to the field of tree-structured indexing methods for the rapid storage and retrieval of DNA profile information from databases containing a large number of records.
BACKGROUND OF THE INVENTION
Existing database indexing methods exploit the structure inherent when more than one database field is used. These methods are commonly based upon space-filling curves to map the multi-dimensional data to a single dimension, which is then indexed in the standard fashion. The B-tree indexing algorithm [1] and similar algorithms attempt to maintain a balanced index tree by adjusting the thresholds used to split the indexed parameter's value set as the tree is descended. Multi-dimensional indexing methods are found under several names, such as R-trees [2] and R*-trees [3], and applications exist in the implementation of image databases and other areas. A parallel database based upon this type of approach has been patented by IBM [4] using MPI, a widely available message-passing interface library for parallel computing [5]. Other implementations exist in some commercial database systems, such as the Informix Dynamic Server's Universal Data Option [6].
DNA profile information consists of allele information at one or more DNA loci or sites. Typically 10 or more loci are used. Typically, individuals can exhibit either one or two alleles at each site; forensic samples containing DNA from two or more individuals can have more alleles. The anticipated size of databases containing DNA profile information necessitates new methods to manage and utilize the stored information. An example of such a database is the national CODIS [11] database, which is expected to eventually store on the order of 10 8 profiles and uses complex match specifications. Standard database indexing structures such as B-trees, which provide rapid access to records based upon the value of a selected database field, are not able to take advantage of naturally occurring structure in the data. Although more than one field may be indexed, the index structures are computed independently. Retrieval of stored information based upon several indices requires an intersection of the results of retrievals based upon each index, which is a time-consuming operation. Methods using R-trees, R*-trees, and similar approaches rely on space filling curves rather than structural properties of the data. There remains a need in the art for database structures and search engines that can rapidly and efficiently store, manage, and retrieve information from very large datasets based upon the structural properties of the data expressed in multiple fields.
SUMMARY OF THE INVENTION
By way of example and without limiting the application of the present invention, it is an object of the invention to organize the storage of DNA profile information to minimize the time required to locate all DNA profiles within the database that satisfy a set of user-selected criteria when compared against a target DNA profile and therefore match the target.
It is a further object of the invention to provide a method for the parallel implementation of a database of DNA profiles by breaking up the work involved in storage and retrieval of sets of information into many requests for work which may be distributed among a cooperating group of computer hosts to balance the workload across the hosts and thereby minimize the time required to perform the work.
These and other objects of the invention are provided by one or more of the embodiments described below.
One embodiment is a method for performing a retrieval operation in a database comprising a tree of nodes. The tree of nodes comprises a root node which is connected to two or more branches originating at the root node. Each branch terminates at a node. Each node other than the root node may be a non-terminal node or a leaf node. Each non-terminal node is connected to two or more branches originating at the non-terminal node and terminating at a node. Each leaf node comprises one or more data records of the database. A test is associated with each non-terminal node that defines a partition of data records based upon either entropy/adjacency partition assignment or data clustering using multivariate statistical analysis. A current node is initially set to the root node. Input is received of a search request providing a retrieval operation and information necessary to perform the retrieval operation. The test associated with a current node is performed responsive to the search request. The test results in identification of zero or more distal nodes connected to the current node. The referenced distal nodes can, according to the test, contain the data record. The test is repeated using an untested referenced distal node which is a non-terminal node as the current node. The retrieval operation is performed on each referenced node that is a leaf node.
Another embodiment is a method of partitioning data records in a computer into groups of roughly equal size. A function is defined of the probability distribution of the values of a designated variable associated with the data records. The function comprises a linear combination of measures of entropy and adjacency. The values of the designated variable are partitioned into two or more groups such that the value of the function is minimized. Each data record is assigned to a group according to the value of the designated variable.
Yet another embodiment is a method of creating a tree-structured index for a database in a computer. The database comprises a tree of nodes. The tree of nodes comprises a root node which is connected to two or more branches originating at the root node. Each branch terminates at a node. Each node other than the root node may be a non-terminal node or a leaf node. Each non-terminal node is connected to two or more branches originating at the non-terminal node and terminating at a node. Each leaf node comprises one or more data records of the database. The tree-structured index comprises one or more tests associated with each non-terminal node. Naturally occurring sets of clusters are identified in the data records of the database. For each identified set of clusters, a test is defined that assigns each data record to a cluster within the set of clusters. One or more such tests are associated with each non-terminal node, together with an associated set of clusters. One branch is associated with each cluster within the set of clusters. The branch originates at the non-terminal node and forms part of one or more paths leading to leaf nodes comprising the data records assigned to the cluster by the test.
Still another embodiment is a method of organizing the data records of a database into clusters. One or more variables in each data record are represented in a binary form, wherein the value of each bit is assigned based on the value of a variable. A set of variables is chosen from those represented in all of the data records such that principal component analysis of the set of variables yields distinct clusters of the data records. Principal component analysis is applied to a sample of the data records, and two or more principal component vectors are identified, whereby the scores of the sample data records along these vectors form distinct clusters. A test is formulated based on the identified principal component vectors which assigns each data record to a cluster. The test is then performed on each data record, and the data records are organized into clusters.
Another embodiment is a parallel data processing architecture for search, storage, and retrieval of data responsive to queries. The architecture includes a root host processor that is responsive to client queries; the root host processor creates a search client object and establishes an initial search queue for a query. The architecture also includes a plurality of host processors accessible by the root host processor. The root and host processors each maintain a list of available host processors, query queue length, and processing capacity for each processor. The architecture includes a bus system that couples the host processors and one or more memories for storing a database tree comprising nodes and data of a database accessible via the nodes. The processors are capable of executing a set of tests and associate one test with each non-terminal node of a database tree.
Yet another embodiment is another method for search, storage and retrieval of data from a database. A set of tests is defined, and one test is associated with each non-terminal node of a database tree. Each test defines a partition of data of the database according to either entropy/adjacency partition assignment or data clustering using multivariable statistical analysis. A test result is output in response to a query by evaluation of either a Boolean expression or a decision tree.
These and other embodiments provide the art with novel, efficient, and rapid methods for the storage, retrieval, and management of large numbers of data records using indexed databases.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 displays the relative frequency of occurrence of alleles at the d13s317 locus.
FIG. 2 presents a schematic representation of a tree-structured database.
FIG. 3 shows a schematic representation of a search server residing on a single host computer.
FIG. 4 shows a minimum entropy partition membership assignment for the d16s539 locus.
FIG. 5 shows a minimum entropy/adjacency partition membership assignment for the d16s539 locus.
FIG. 6 shows a minimum entropy/adjacency partition membership assignment for the d16s539 locus where too great a weight is afforded the adjacency cost.
FIG. 7 presents a schematic representation of the C++ Node object.
FIG. 8 provides a schematic representation of the C++ Partition object.
FIG. 9 demonstrates the effect of allele equivalence.
FIG. 10 illustrates the effect of RFLP measurement error.\
FIG. 11 demonstrates search requests at loci with more than two alleles.
FIG. 12 presents a Scree plot showing the cumulative contribution made by each principal component.
FIG. 13 shows Mahalanobis scores onto principal components 2 and 3 of the 10000 data profiles with alleles in d13s317 and d16s539.
FIG. 14 shows the allele frequency distribution for the d13s317 locus.
FIG. 15 shows the allele frequency distribution for the d16s539 locus.
FIG. 16 shows the joint probability density of 2-allele distribution in the d13s317 locus.
FIG. 17 shows the joint probability density of 2-allele distribution in the d16s539 locus.
FIG. 18 shows a joint 2-loci allele pair probability distribution pattern.
FIG. 19 shows the makeup of the second principal component for the d13s-d16s data set. Note that the allele index numbers do not correspond to the actual allele number. The tall bars correspond to alleles 11 and 12 of d13s17 and alleles 11 and 12 of d16s539 respectively.
FIG. 20 shows the makeup of the third principal component for the d13s-d16s data set. Note that the allele index number do not correspond to the actual allele number. The tall bars correspond to alleles 11 (−) and 12 (+) of d13s317 and alleles 11 (−) and 12 (+) of d16s539 respectively.
FIG. 21 shows the fraction of profiles within each PCA scores cluster that has each of the alleles in the d13s317 and d16s539 loci pair.
FIG. 22 displays a comparison of the locations of true cluster centers (*) and the approximate ones (o), which are predicted from the allele distribution patterns at the four dominant allele positions.
FIG. 23 shows the scores plot for both the large synthetic data set and the small real sample set. The scores from the large data set (the dark gray points) completely cover those of the small real sample set.
FIG. 24 shows the scores plot for both the large synthetic data set (medium gray points) and the small real sample set (the black dark points).
FIG. 25 shows a comparison of the fraction of the sample population that is in each of the nine PCA clusters. The first of each pair of bars at each cluster number position denotes that of the large data set (10,000 synthetic Caucasian data records); the second of each pair of bars represents that of the small real data set (176 Caucasian data records).
FIG. 26 presents a histogram of times required to search a database of 100,000 DNA profiles for an exact match to a specified profile (5,019 runs).
FIG. 27 illustrates a database tree containing 100,000 DNA profiles.
FIG. 28 depicts a parallel architecture implementation of the invention.
FIG. 29 represents a method of indexed storage and retrieval of multidimensional information according to a first embodiment.
FIG. 30 represents a method of indexed storage and retrieval of multidimensional information according to a second embodiment.
DETAILED DESCRIPTION OF THE INVENTION
The inventors have developed a method of organizing the storage of DNA profile information which minimizes the time required to locate all DNA profiles within the database that satisfy a set of user-selected criteria when compared against a target DNA profile and therefore match the target. The match criteria allow for the possibility of missing allele or locus data, the inexact match of allele information at a specified locus, an error tolerance in the number of base pairs in matching alleles from RFLP DNA locus data, and the specification of equivalent alleles. The match criteria can also define groups of loci that must be present in matching DNA profiles and a maximum number of matching profiles to be returned to the requesting user.
DEFINITIONS
A “directed graph” is a pair (N, B), where N is a finite set and B is a binary relation on N Elements of the set N are called the nodes of the directed graph. A “node” is an element of a set N in a directed graph or tree, such element having connections with branches that either originate from or terminate to the element. The binary relation B is a set of elements of the form (n 1 , n 2 ), where n 1 and n 2 are elements of N. Elements (n 1 , n 2 ) of the binary relation B are called branches or edges of the directed graph and specify a path from node n 1 to node n 2 . For a directed graph, a “path” is a set of branches {(n 1 , n 2 ), (n 2 , n 3 ), . . . (n i−1 , n i )}, containing at least one branch, that connects node n 1 to node n 2 defines a path from the originating node n 1 to the terminal node n 2 . The path is said to go from node n 1 to node n 2 . For a directed graph, a node n 2 is “reachable” from node n 1 if a path exists that originates at node n 1 and terminates at node n 2 ′.
A “tree” is a directed graph that satisfies two properties: (1) for any two nodes n 1 and n 2 , a path exists from node n 1 to node n 2 , or a path exists from node n 2 to node n 1 , (the graph is connected); and (2) no two nodes n 1 and n 2 exist for which paths exist from node n 1 to node n 2 and from node n 2 to node n 1 (the graph is acyclic). For purposes of the invention, a tree can be either a directed graph or an undirected graph. The “root” or “root node” is the unique node of a tree that is not a terminal node for any path in the tree. A “non-terminal” or “non-terminal node” is a node of a tree that is an originating node for at least one path in the tree; ( FIGS. 30 , 3030 and 3040 ). A “leaf” or “leaf node” is a node of a tree that is not a non-terminal node. A “subtree” of a tree (N, B) is defined uniquely by any node n r of the tree, and is the tree (N s , B s ) formed of the set N s containing the node n r and all nodes nεN that are reachable from node n r , and the set B s containing all branches that are in paths in the tree that originate at node n r . Node n r is the root node of the subtree (N s , B s ). As referred to herein, a “node” can be a carrier of information or data.
For purposes of the invention, any information or data may be optionally contained in, referenced by, attached to, or associated with any node or branch of a tree or directed graph. When a node has a specific structure which determines how information may be contained in, referenced by, attached to, or associated with the node, the node is referred to as a Node object or Node (capitalized).
Additional background information about directed graphs and trees can be found in reference 1 at pp. 86-97.
Search and Retrieval Operations in DNA Profile Databases
It is intended that the claimed invention can be used with any appropriate database. The application of the invention to databases containing DNA profile information is preferred. In the description that follows, the CODIS system is used by example only and is not intended to limit the scope of the invention.
Estimates of the relative frequency of occurrence of each possible allele at each locus are known for various population subgroups. The relative frequency distribution is typically not uniform. The current invention exploits this non-uniformity to improve the efficiency of DNA profile databases. A table can be created of the known alleles that may be present at a specific locus and their relative frequency. One such table for the d13s317 locus, based upon FBI CODIS data, is shown in Table 1. For this locus, there are two alleles (11 and 12) that have significantly larger fractions (frequencies of occurrence) than the others. This is easily seen in FIG. 1 . Non-uniform allele frequency structure is apparent at several loci. The database search engine described here exploits such non-uniformity using a “divide-and-conquer” strategy.
TABLE 1
Relative frequency of occurrence of alleles at the d13s17 locus.
Bin
Allele
Fraction
1
7
0.000
2
8
0.115
3
9
0.078
4
10
0.070
5
11
0.313
6
12
0.283
7
13
0.098
8
14
0.043
9
15
0.003
Total
1.000
A tree-structured information storage scheme is shown in FIG. 2 . At each node of the tree, beginning at the top (root) node, a test is made upon DNA profile information (either used as a target for a search request or to be stored in the database). Based upon the test results, one or more branches are selected that originate from the node and terminate at child nodes where a new test is conducted. In this manner, portions of the database are ruled out of consideration at each level, narrowing the scope of the search. The complexity of the search method that results is on the order of log(N), where N is the number of DNA profiles stored in the database.
For this to be effective, test results associated with the database tree's nodes need to depend upon information at more than one locus of the DNA profile. In addition, the tests need to be chosen in a manner that causes the resulting tree to be balanced. This means that all paths from the root to leaf nodes where DNA profiles are stored are roughly the same length. This causes the portions of the database contained in the subtrees rooted at nodes at each level of the tree to be roughly the same size, as is shown in FIG. 2 where the percentage of DNA profiles in the database referenced by each node of the tree is shown at that node.
The tree structure of the database has the additional benefit of being parallelizable. Each branch leading from a node that is chosen as a result of a test can be assigned to an independent computer host or processor, allowing exploration of the tree during a search to proceed on multiple computer hosts in parallel. In the illustrated database in FIG. 2 , each of the three bottommost nodes can be assigned to a different computer, resulting in three roughly equal search problem sizes.
A unique feature of the method described here is its use of a priori information about the statistical distribution of DNA profile information to ensure that the database tree is balanced.
Search and Retrieval Operations in Other Database Types
The multivariate statistical clustering method and information storage and retrieval methods that utilize this can be applied to other forensic science applications. These applications include the categorization and classification of any forensic evidence sharing one or more attributes. For example, these methods can be used to compare the events and construction technologies describing improvised explosive and incendiary devices (bombs). The multivariate statistical clustering method will reveal similar cases presented to an existing bomb incident database. In this embodiment, clusterable variables include the presence or absence of various types of explosives, methods of construction, and ancillary devices such as timing devices and other triggers. This type of database is beneficial for determining patterns in similar bombs constructed by the same individual(s) as well as circumstances surrounding their placement, the target, and the motive of the bomber. Other forensic applications include psychological and personality profiles of criminals, descriptions of stolen artwork, indexing, storage, and comparison of forged documents, linguistic content of threatening communications, image comparisons of spent bullet and cartridge cases, photographic images of crime scenes, determination of authorship of copyrighted works, and the content of computer hard drives.
Beyond forensic applications, these methods are applicable in any domain of knowledge where information to be stored, indexed, retrieved, and compared can be characterized by the presence or absence of common features. Suitable application domains include maintenance of image databases, such as arrest photos and catalogs of identifying marks (scars, marks, blemishes, and tattoos). In agriculture, image databases are maintained of crop pests, and an important application is the rapid identification of pests on samples of infested plants. In planetary science, image databases are maintained of landforms and features taken from both space and air platforms, and the rapid identification of an image of a location on the earth's surface is important. In these application domains it is possible to extract image features that can be coded by their presence or absence, allowing the utilization of the multivariate statistical clustering method and related database methods. Within each category of feature, the features may be typed by degree, such as physical size, color attributes, and texture. This typing admits the application of entropy/adjacency partition assignment methods as a mechanism for partitioning a collection of information in order to facilitate rapid comparison, access, and retrieval.
Another application domain is the storage of references to textual information. Representation of text documents by vectors indicating the presence or absence of words and phrases, which may then provide indexing structure through the use of multivariate statistical clustering and data access methods. Locations of words and phrases within a document, as well as the relative positions and frequencies of these words and phrases, enable the utilization of the entropy/adjacency partitioning method and related database indexing structures. These types of representation have been utilized with singular value decomposition and QR factorization for text storage and retrieval [14]; however, the methods described herein use clusters derived from multivariate statistical analysis to partition the database and form a database tree. Wherever the application provides a natural association of the representations of quantities such as measurements of word positions and frequencies with a distance or similarity measure of association between data records, database trees utilizing entropy/adjacency partitions can provide highly efficient methods for identification of records most similar to a target record referenced by a search request. In these and other applications where a binary encoding of information relating to the presence or absence of data features is appropriate, database trees utilizing clustering based upon multivariate statistical analysis can provide highly efficient methods to implement database indexing, search, and retrieval strategies. In most applications, a combination of these methods can be utilized.
The above disclosure generally describes the present invention. A more complete understanding can be obtained by reference to the following specific examples, which are provided herein for purposes of illustration only and are not intended to limit the scope of the invention.
EXAMPLE 1
Database Implementation
A key to implementation of the search specification on a tree-structured database is what occurs at the nodes of the database tree. These nodes can be C++ objects and can contain partition objects used to describe how the database is segmented at each node. Two types of partitioning at the nodes are illustrated: entropy-adjacency partition assignment (See FIG. 29 ) and data clustering using multivariate statistical analysis (See FIG. 30 ). The database is implemented using a Search Queue and one or more Search Engines in each computer host in a single or parallel computer environment. The Search Queue holds Search Requests and additional information such as requests to store or delete DNA profile information in the database. The Search Engines take elements from the Search Queues and perform the requested activities. During this process, additional Search Requests may be generated, which each Search Engine places in the Search Queue. The CODIS search engine communicates with clients that request service across a network interface, and returns the requested information to these clients. This process is shown schematically in FIG. 3 for the single host case. Multiple hosts in a parallel computing environment are accommodated using multiple communicating copies of this process. The hosts can either all operate on the same database, or each can contain a portion of the database; a mixture of the two methods can also be used. As an example, communicating groups of processors may operate where all members of each group are assigned the same portion of the database.
In FIG. 3 , the client initiates a request for service with the Server, which is a computer process whose sole function is to broker exchanges between clients and the CODIS search server. Upon receipt of a connection request, the Server instantiates a Server Client, which is a computer process or thread dedicated to servicing the client. If the client is initiating a request to search the database, information necessary to define the Search Request is transmitted from the Client to the Server Client, and the Server Client assembles a Search Request and inserts it in the Search Queue (labeled “Queue of Search Requests” in FIG. 3 ).
A Search Engine removes the topmost (oldest) Search Request from the Search Queue when it becomes available. The Search Request specifies an identifier for the requesting Client, an associated node of the database tree at which the search is to begin, and a set of target DNA profiles and related information specifying the context of the search. If the database tree node is not a leaf node (has descendents), the Search Engine can use one of the available partitioning methods to determine which nodes at the next lower level of its database tree must be searched. If the node is a leaf node, the Search Engine searches the set of DNA profiles stored at the node for matches. This process may either generate additional Search Requests or matching DNA profiles. Search Requests are placed on the Search Queue, and matching DNA profiles are returned to the Client. The Search Engine can follow one branch to a next lower node and repeat the process in order to achieve higher performance rather than insert the corresponding Search Request onto the Search Queue. The Search Engine block in FIG. 3 is schematically shown as a single process or thread, but it should be understood to represent one or more Search Engines on a single computer host.
Various methods can be utilized to balance the loads of the computer hosts so that the average waiting times for service and computation in Search Queues and Search Engines across all hosts are equalized. For example, blocks of Search Requests can be exchanged among hosts from hosts with relatively long average waiting times to hosts with shorter waiting times. A stochastic scheduling method can be utilized, causing hosts with relatively short waiting times to, on average, receive more exchanges than hosts with longer average waiting times. The sizes of the blocks exchanged can be adjusted to accommodate the relative speeds of the processors and the inter-processor communications protocols and hardware. Either of two software packages used for parallel computing, MPI [5] and PVM [7], or other similar packages, can be used to implement the balancing method.
The Main block shown in FIG. 3 starts the execution of the Server, Search Queue, and Search Engines on a computer host and initialized the environment to allow these processes to communicate with other hosts participating in the parallel computer environment. In addition, various log files can be generated to aid in debugging problems and tracing utilization of the CODIS search server; two of these are shown in the figure.
EXAMPLE 2
Entropy-Adjacency Partition Assignment
To minimize worst-case search time, division of the database into N roughly equal portions at each level of the database tree is highly desirable. A simple and fast test is needed to accomplish this. One test method that can be used to accomplish this is entropy-adjacency partition assignment; refer to FIG. 29 , (e.g., 2910 ). This method assigns members of the set of possible allele pairs at a specified locus to groups. The goal is to choose these groups so that their expected sizes are roughly equal, and so that alleles with indices that differ by a small number (corresponding to the number of repeated sequences for STR DNA profiles and the number of base pairs for RFLP DNA profiles) have a high probability of being assigned to the same group. By preferentially assigning alleles differing by a small number of base pairs to the same group, the growth of the number of generated search requests due to a client's specification of equivalent alleles will be less than would be the case for other assignments.
The set of possible allele pairs at a locus can be viewed as a two-dimensional grid, where each row or column corresponds to an allele. Since the pair (allele1, allele2) is the same as the pair (allele2, allele1), any partition assignment on this grid is symmetric. Thus, only half need be shown. A partition assignment that minimizes the entropy of the resulting partitions is shown in FIG. 4 for the d16s539 locus. In the figure, different shadings of gray (colors can also be used) correspond to different partition membership assignments. The axes are labeled with the sequence numbers of the d16s539 alleles; the alleles range from 5 to 15 inclusive. Entropy is a concept from information theory, and for the partition assignment problem minimum entropy is equivalent to creating a partition whose members are as close as possible to the same size (expected number of elements). From the figure, it is apparent that minimum entropy assignment does not tend to assign adjacent allele pairs to the same partition member.
The partition assignment problem (refers to Step 2920 ; FIG. 29 ) can be solved by a global optimization procedure based upon simulated annealing. In this method, an initial random assignment is chosen, and its cost (entropy) is calculated. The assignments are represented by non-negative integers. In the figure, a division of the allele pairs into six partition members is desired, and the members are labeled with the integers 0 through 5, inclusive. The optimization procedure randomly chooses an allele pair to modify and randomly chooses a proposed new assignment for that pair. The change in cost that would result if the new assignment were used is calculated, and if the cost decreases the proposed change is accepted. If the cost increases the proposed change is accepted with a probability p that begins with unity and declines monotonically with iteration number as the optimization process proceeds. An exponentially decreasing probability of acceptance (a geometric sequence) has been found to work well in practice. The optimization procedure terminates when either the cost has not been further decreased over a specified number of iterations or a maximum number of iterations has been achieved. The last computed assignment is used as the solution to the problem. A variation of this procedure, which is used in the Examples, is to maintain a copy of the best (lowest cost) assignment achieved through the current iteration, updating this as better assignments are found, and to use the last best assignment as the optimal assignment.
Preferential assignment of adjoining allele pairs can be achieved by introducing a cost associated with the absence of adjacency. For every allele pair (A), the four (less on the boundaries) assignments for allele pairs that differ by one index in one allele are examined, and a count variable is initialized to zero. For every assignment that differs from the assignment of allele pair (A), a one is added to the count variable. The count variable is then scaled by the probability of the allele pair's occurrence, and these scaled values are summed over all possible allele pairs to form the adjacency cost. An allele pair with zero probability of occurrence can allow the assignment of that pair to be arbitrarily made without regard to adjacency. To avoid this problem, a small number can be added to the probabilities of occurrence, or to those that are zero, causing the assignment to affect the cost. The results reported herein utilized a value of 0.005 added to all allele pair probabilities of occurrence. The resulting adjacency cost is linearly combined with the entropy cost, and the combined cost is minimized using the global optimization procedure. This can be expressed by the equation
Cost=Entropy+Weight*Adjacency
where Entropy is the cost due to the non-uniform size of the partition members, Adjacency is the cost due to the existence of adjacent allele pairs having different assignments, and Weight is a non-negative number defining the relative importance assigned to the adjacency cost; see step 2910 , FIG. 29 , for example.
For certain linear combinations, this cost function results in adjacent groups of allele pairs being assigned to the same partition member without drastically impacting the entropy (measure of non-uniform partitioning) of the result. This effect can be seen visually in FIG. 5 , where the allele pairs of locus d15s539 are partitioned into six groups. For this partition assignment the entropy is 1.01201, whereas for the assignment shown in FIG. 4 the entropy is 1.0111.
This process can be carried to an extreme by weighting the adjacency cost too heavily. In this case, the number of partition members decreases with some members containing zero elements. This effect is visible in FIG. 6 . At the present time a precise way to select the “best” trade-off between entropy and adjacency is not known. If minimization of entropy cost is too heavily favored, search performance using equivalence and RFLP error tolerances will be adversely affected. If adjacency is too heavily favored, the database tree will be become unbalanced, resulting in “long legs” and poor worst-case performance. “Engineering judgment” can be used to select a partition map (via the weight) from many computed solutions that will yield acceptable performance. This can be done by computing optimal solutions to the assignment problem (step 2930 , FIG. 29 ) for a variety of non-negative weights. If the weight is too large not all partitions will contain assigned allele pairs. If the weight is too small assignments similar to those shown in FIG. 4 will be observed. Iteration may be required to determine suitable values.
EXAMPLE 3
Database Design Using Entropy-Adjacency Partitions
A schematic representation of the database tree was presented in FIG. 2 . In that figure, each node of the tree is represented as being implemented using an entropy-adjacency partition. In practice, this is only one of two methods that may be used at a node, and the tree may contain a mixture of the two cases. The implementation of the tree nodes using entropy-adjacency partitions ( FIG. 29 ) will be discussed in detail in this section; however, the implementation of the tree nodes can also be accomplished using data clustering ( FIG. 30 ).
A decision tree node can be implemented by a C++ Node object, as shown schematically in FIG. 7 . The object can contain a unique identifying integer stored in the thisnode parameter. A Node object may be either a leaf or non-leaf (non-terminal) tree node, as specified by the Node data element isleaf ( FIG. 30 , 3040 ). If it is a leaf, the node can store DNA profile information located at that portion of the tree in a storage data structure. As DNA profiles are being stored into the database, a threshold is utilized to determine at what point a leaf node should be converted to a non-terminal node, resulting in two or more nodes one level below the node ( FIG. 30 , 3040 ). Nodes can track the total number of DNA profiles they reference in the nmembers parameter. The offset parameter can be used when stored DNA profiles are located out of processor memory, for example on a disk drive to locate the information relative to the start of the storage media.
Non-terminal Node objects can maintain a list of nodes (nextnode), referenced by the locations of the corresponding Node objects in an array, that can be reached by branches from the nodes and are one level below the nodes in the database tree. Nodes based upon entropy-adjacency partitions can contain a pointer to a C++ Partition object (ppart), which can implement the data structures and methods necessary to utilize the partition information. For each allele pair associated with a partition, a count of DNA profiles matching that allele pair can be maintained by the Node object in the allele_cnt map. This information can be utilized to avoid searches along branches from the node that contain no DNA profiles capable of matching a target DNA profile.
A C++ Partition object can be used to store entropy-adjacency partition assignment information. A Partition object defines which subset of the database associated with the database tree node a profile belongs in. These objects are represented schematically in FIG. 8 . A string identifying the locus used for the partition can be stored in a name entry. A nmembers entry can specify the number of groups in the partition. Missing allele pair values can be accommodated; a probability of the occurrence of missing data can be maintained in a pmissing entry. A vector of probabilities of occurrence, one for each possible allele, can be maintained in a popstat structure. The table of partition assignments, along with the probabilities of occurrence of each allele pair, can be maintained in a table map. Each entry of this map is a PartEntry object containing the assignment and probability.
Partitions can be used by many database tree nodes and are therefore not usually included within the Node objects. Rather, a pointer in the Node objects can be maintained to the appropriate Partition object. The Nodes can be stored in an array in a predetermined order which is consistent across all hosts participating in the parallel machine, allowing Search Requests to be exchanged across host boundaries.
EXAMPLE 4
Mapping Match Specifications to Methods
The CODIS system provides detailed specifications [11] governing how two DNA profiles may match. A matching algorithm used with CODIS must correctly account for:
PCR allele equivalence, RFLP measurement error, Match stringency on a per-locus and per-profile basis, Mismatch on a maximum allowed number of loci, Matches on a minimum number of loci, Completeness, and The maximum number of DNA profiles to be returned in response to a search request.
Most of these specifications can be interpreted using locus partition and search state information.
Search Requests can be evaluated by the C++ Node objects. The node can use the Search Request's stored information, along with the partition information referenced by the Node, to generate results, which are returned to the requesting Client, or new Search Requests. Results are only generated when the Node object is a leaf node and contains DNA profiles. If PCR alleles at a locus are declared equivalent, then a DNA profile target provided by a Search Request that contains one of these alleles must match all of the equivalent alleles as well. This is shown in FIG. 9 where the Search Request contains a target profile with allele information for locus d13s317 (alleles 3 and 5), and declares that alleles 2 and 4 are equivalent to allele 3. The yellow (lighter) “X” in the figure corresponds to the allele pair (3,5) and is located in the partition assignment designated by the blue shading. The pink (darker) “X”s in the figure correspond to the allele pairs (2,5) and (4,5), both of which also match (3,5) because of the declared equivalence. Since the allele pair (4,5) is assigned the partition designated by the yellow (light) shading, two new Search Requests are generated (assuming the allele_ent table entries are positive) for the “blue” (dark) and “yellow” (light) partitions.
The search behavior induced by RFLP measurement error is similar to the case of PCR allele equivalence. Measurement error in CODIS is represented by percent relative error bounds on the stored values of RFLP bands. The result is a region (represented by a square in the next figure) within which a band is required to match RFLP DNA target information. Any squares representing ranges of stored RFLP data that intersect this region can cause new Search Requests to be generated, as shown in FIG. 10 .
DNA profile loci can contain more than two alleles due to the presence of mixed samples (DNA material from multiple individuals). In this case all pairs that can be formed from the alleles that exist at a locus are used to reference partition cells. In FIG. 11 the DNA profile target contains the alleles 3, 4, and 6 at the d13s317 locus. As a result, the allele pairs (3,4), (3,6), and (4,6) are used to determine new Search Requests.
CODIS defines the concept of match stringency. High stringency matches require the presence of exactly the same alleles at the locus in the target and retrieved samples. Medium stringency allows additional alleles to be present in the retrieved samples and some loci, and low stringency allows a partial correspondence between the alleles to trigger a match. Work on implementation of the medium and low stringency match methods is in progress; however, conceptually these cases are very similar to what is required for equivalent alleles and RFLP error bounds.
In order to discuss how thresholds on the maximum number of allowed misses and the minimum number of required matches are handled, it is necessary to describe a representation of Search Request objects. Misses due to the absence of information for a locus can be handled in a similar fashion. These thresholds affect the number of Node objects in the tree that must be evaluated and can lower search performance if they are chosen poorly. A Search Request object can maintain the following information:
node: the node number in the database tree where the search is to occur (initially zero, indicating the root node) pPartPrfl: a pointer to the search information (partition profile) pResult: a pointer to a place to put search results mismatch: a count-down counter of mismatches allowed.
The mismatch counter is an example of the Search Request object's ability to carry search state information. This counter specifies the number of misses that may be accumulated from the current point on in the search. Every time a miss is allowed at a node the mismatch counter is decremented and stored in the new Search Request object.
A missing allele is equivalent to the homozygous case. Missing locus data can be handled using either of two approaches. The first uses a special partition entry to reference profiles with no information for the locus. The second stores profiles with missing alleles in all partition entries of the partition corresponding to the locus which would be capable of matching the profile if an allele were present. The first method increases the size of the database tree; the second method increases the number of nodes that must be searched. Because the second method essentially removes the ability to avoid searching partitions having no entries, the first method is preferred.
A constraint can be placed on the maximum number of matching DNA profiles. Search Queue objects can provide the Search Engines with an indication that the maximum number of targets has been returned for a specific search request, causing the Search Engines to ignore subsequent search requests with the same identifier. The Search Queue objects receive this notification from the Server Client, which receives matching DNA profiles as they are generated.
The CODIS completeness condition is fairly complex, requiring the determination that specific combinations of loci data are present in matching DNA profiles. This condition is evaluated only at leaf nodes of the database tree to exclude profiles that fail the requirement.
EXAMPLE 5
Multivariate Statistical Clustering Method (FIG. 29 , 30 )
This section provides a description of a method that uses multivariate statistical methods to determine clusters ( FIG. 30 , 3010 ) that can be utilized to partition portions of a database into groups of roughly equal size (FIG., 29 , 2920 ). As a result, this method generates partition information that can be incorporated within or associated with an arbitrary Node object in a database tree; ( FIG. 30 , 3040 ). The application of this method to DNA profile data based upon amplification of short tandem repeat (STR) DNA locus data is presented. For this case, a clear binary encoding of the alleles present at a STR locus is available. For other data types, such as DNA RFLP allele (band) data, the proper choice of a binary encoding scheme is not as easy to determine, and at the present time the binary encoding is necessary.
The DNA STR profiles in the database are first represented in a binary form, using a ‘1’ to denote the presence, and a ‘0’ to denote the absence of an allele at a locus. Based on the allele distribution patterns among two chosen STR loci, clusterable patterns are discernable after principal component analysis of the data matrix. Distinct clusters, usually less than 10, can be established using a clustering method, such as k-means [12]; ( FIG. 30 , 3010 ). The membership of each cluster is then identified and recorded. Each DNA STR profile belongs to one and only one of these clusters. Thus, the entire set of DNA profiles in the data base can be partitioned into these clusters, based on the allele distribution at these two chosen loci.
When searching for matching profiles to a target profile, the target's DNA profile can be classified into one of these clusters, based on its allele distribution information at these two loci. Thus, a subsequent search can be restricted to members within this cluster. This reduces the search problem by approximately one order of magnitude.
The search process continues by examination of the target's allele distribution at other pairs of STR loci, resulting in classification to a subsequent PCA cluster and reduction of the number of possible matches by another order of magnitude at each level of the database tree. Partitions based on PCA clustering can be inserted into a nonterminal Node object of the database tree at any point and freely intermixed with partitions based upon entropy/adjacency partition assignment.
EXAMPLE 6
Binary Representation of the STR Profile
The STR profiles are first converted into a binary format, with a ‘1’ representing the presence and a ‘0’ the absence of an allele at each locus. Thus the binary representation of a collection of DNA STR profiles is a sparse matrix of mostly zeros and some ones. Each row of this matrix is the representation of one DNA STR profile. The maximum number of 1's for each profile (for samples that are not mixtures of material from two or more individuals) is two times the number of loci, assuming heterozygous presence of alleles at each locus. The minimum number of ‘1’s is equal to the number of loci used for each profile, assuming homozygosity at all loci.
EXAMPLE 7
Clustering by Principal Component Analysis (FIG. 30 , 3010 )
Principal component analysis (PCA), a popular method of performing multivariate statistical analysis, represents a matrix of high dimension, consisting of correlated information, with a much lower dimensional matrix, without sacrificing significant information contained in the original data matrix. PCA involves a rotation from the original frame of reference to a new frame of reference, whose axes are given by the principal components from the PCA. The first principal component represents the direction along which the variance exhibited by the original data points is maximized. The second principal component, orthogonal to the first, represents the direction along which the remaining variance is maximized. Additional principal components are defined in a similar fashion.
EXAMPLE 8
PCA by Singular Value Decomposition
To implement PCA, the preferred method is to use the singular value decomposition (SVD) [9] to decompose the data matrix, X, into the product of three matrices, in which the columns of the matrix, V, are referred to as the “principal components” of the PCA of the data matrix, X. Other methods known in the art may be used to obtain equivalent information. Thus,
X=UΓV T (Eq. 1)
where U and V are orthogonal matrices, and Γ is a diagonal matrix with positive elements arranged in descending order. The columns of V, being the principal components, represent the coordinates or basis of the axes of the new frame of reference. The ratio of the square of each singular value to the total sum of squares of all the singular values represents the percentage of the total variation contributed by each principal component. A Scree plot can be developed to show the cumulative ratio of this measure; an example is shown in FIG. 12 . Since the original data are assumed to be heavily correlated, and the singular values are arranged in descending order, one can make a decision as to how many principal components to keep in building the PCA model to represent the original data. The discarded data along the remaining principal components are regarded as less important and are ignored.
EXAMPLE 9
The Principal Components
Each principal component is of unit length and orthogonal to all other principal components. The principal components are the columns of the right singular matrix, V, of the SVD of the data matrix, X, above. Each principal component is expressed as a linear combination of the original variables, with the entries of the principal component expressing that particular linear combination. The absolute values of all entries are less than or at most equal to 1. Therefore, those entries with relatively large values indicate the heavier weight their corresponding original variables occupy in making up this particular principal component. The variables with correspondingly heavy weights are also the ones being correlated in the original data set. If the columns of the data matrix X are not first mean centered, such that the mean of each treated column is zero, then the first principal component reflects the average values of the variables represented in the new principal component frame of reference. It is then the next few principal components that serve to differentiate between profiles. Therefore, mean centering is an optional step which provides no additional capability and is not performed here.
EXAMPLE 10
The Scores Vectors and Normalized Scores Vectors
After the principal components are found, each data profile can be projected onto each principal component. The projected vector is referred to as the scores vector. The length of the scores vector indicates how closely aligned that data profile is to that principal component. The bigger the projection, the better this principal component represents this data profile. Thus, data profiles with comparable projections onto this principal component can be regarded as “similar” to each other, with respect to this principal component. Those profiles with high projected values onto this principal component indicate that these profiles are highly aligned with that of the principal component, therefore representing more of the original variables which are heavily weighted in that principal component. Similarly, projections of data profiles onto each of the succeeding principal components can be carried out to get the scores and their projections onto those principal components.
Because of the different degree of variation exhibited by the data profiles along the different principal components, normalization is necessary, such that normalized distances from the origin to each projected point can be compared meaningfully to each other. Therefore, the Mahalanobis distance measure [12] is employed, in which each projection is divided by the corresponding singular value. The Mahalanobis distance scores are calculated as follows:
Mahalanobis_scores= XVΓ −1 =( UΓV ′) VΓ −1 =U (Eq. 2)
where X represents the original data matrix, and U, Γ and V are from the SVD of X, as shown in Eq. 1. Postmultiplying X by V performs the projection of the rows of X (profiles) onto the principal components, with the projected vectors represented with respect to the principal component axes. Postmultiplying XV by Σ −1 scales each column of XV by the corresponding singular values contained in Σ. A two dimensional plot can be used to show the scores onto principal components PC2 and PC3. In plotting the scores plot in, say PC2 and PC3, it is the row entries from the second and the third columns of the Mahalanobis_scores matrix (the U matrix in Eq. 2) that are plotted in a 2-d plot. From henceforth, the Mahalanobis_scores shall simply be referred to as the scores. An example of such plot is shown in FIG. 13 , which shows the scores for 10000 DNA STR profiles in the d13s317 and d16s539 loci onto the 2nd and 3rd principal components. It is in such a scores plot that clusterability of the sample points is examined.
EXAMPLE 11
Identification of Clusters
A clustering algorithm can be employed to perform clustering of the scores projected onto a 2-d principal component space; ( FIG. 30 , 3010 ). K-means [12] is selected because of its wide use and simplicity. However, with k-means the number of clusters has to be specified before the algorithm can begin. This is not a problem because the choice of the two loci, the two principal components on which to project the data, as well as the number of clusters associated with the scores, are all identified by a priori visual inspection and recorded.
K-means clustering starts with an arbitrary set of n points, where n denotes the number of desired clusters, to serve as the center of each cluster. Each data point is assigned to that cluster to which it is “closest” using a distance measure of the user's choice. The standard Euclidian distance measure is used here. This is followed by a calculation for the new center points of the resultant n clusters. Then, in the next round of iteration, clusters are re-formed by assigning to each of the new centers points that are now closest to each. Iterations continue the cluster centers no longer change or a specified number of iterations is reached.
After clusters are formed, the membership of each cluster can be identified and the corresponding DNA STR profiles can be extracted from the original database for future study.
EXAMPLE 12
Projection of New DNA STR Data Set onto the Principal Components of Another
The DNA STR profiles of one group can be compared to that of another by comparing the corresponding scores patterns onto a principal component reference frame. To do the comparison, the projections of the profiles of the second set may be normalized by the inverse of the singular values of the first set. The projection and the normalization to arrive at the Mahalanobis scores of the second data set is carried out as follows:
M_scores 2nd =X 2nd V 1st Γ 1st −1 (Eq. 3)
M_scores denotes the Mahalanobis scores, which shall simply be referred to as the scores. In plotting the scores plot in, say PC2 and PC3, it is the row entries from the second and the third columns of the M_scores matrix that are plotted in a 2-d plot.
EXAMPLE 13
Principal Component Analysis of the Synthetic Data in 2 Loci
Study of clustering by PCA was carried out with two sets of data. The first was a synthetic data set, generated from the known allele frequency distribution for each of sixteen STR loci. The distribution is from the CODIS data base. A binary set composed of 10,000 profiles with allele specifications at 16 loci was thus generated. This data matrix has the dimension of 10,000 by 202, and is sparse with all entries either 1 or 0. Each row denotes the STR profile in all 16 loci for one individual; each element of a column represents the presence (1) or absence (0) of the corresponding allele in the each of the 10,000 individuals. The second set of data studied was compiled from human population studies and released by B. Budowle [10] of the FBI, and is composed of DNA STR information of six ethnic groups with about two hundred samples in each group. A PCA model was developed with the large synthetic data set, and the small real data set was projected onto the principal components derived from the former. Relative percentages of membership profiles in the clusters were also compared between the large and the small data sets in order to compare the corresponding allele frequency distributions.
The locus pair of d13s317 and d16s539 was chosen for illustration of the PCA analysis and clustering study. The columns corresponding to the alleles of these two loci from the 10,000 by 202 synthetic data set were extracted, and subjected to singular value decomposition (SVD) to obtain the principal components (the columns of the V matrix in Eq. 1) and the Mahalanobis scores vectors (the columns of the U matrix in Eq. 1). The corresponding columns of the data matrix, X, extracted are columns 11 through 19 (corresponding to alleles 7-15 of the d13s317 locus) and columns 20 to 30 (corresponding to alleles 5-15 of the d16s539 locus) for a total of 20 columns. The SVD of this submatrix of size 10,000 by 20 was computed. First, the number of principal components to retain to build the PCA model was ascertained. FIG. 12 is the Scree plot showing the cumulative contribution made by the principal components. The plot shows that the first three principal components together capture about 60% of the total variation exhibited by the original data matrix. It further shows that the rank of the matrix is 14, meaning there are only 14 independent columns among the total of 20 columns of X. Note that each successive principal component contributes less to the overall data variation, as foreshadowed by the decreasing magnitude of each successive singular value squared of the data matrix, X.
EXAMPLE 14
Scores Plot onto PC2 and PC3
The 10,000 profiles with alleles at d13s317 and d16s539 were projected onto the second and third principal components, followed by normalization by the inverse of the corresponding singular values to arrive at the Mahalanobis scores. The entries of each row after projection and normalization were plotted in a 2-d scores plot. FIG. 13 shows the result. Nine distinct clusters were observed.
EXAMPLE 15
Analyzing the Clusterability of Other 2-Loci Combinations
The clusterability of other 2-loci combinations was also studied. There are a total of 16 loci available for analysis. Therefore, a total of 120 2-loci combinations (16*15/2=120) were analyzed. Table 2 shows those 2-loci combinations and the corresponding supporting principal components that yield good and distinct clusters. The reason that only certain 2 loci combinations yield good clusters is further analyzed so as to understand the role the alleles at each locus play in determining the clusterability of the profiles. The following subsections present the rationale. Briefly, however, those loci pairs with allele probability densities concentrating at just a few of alleles tend to yield good and distinct clusters.
The corresponding principal components are shown, as well as the number of clusters. V1 and V2 denote the identity of the first and the second principal component specification, onto which good clustering of the projected scores is observed; ( FIG. 30 , 3010 ).
N
N
clus-
Locus 1
Locus 2
V1
V2
clusters
Locus 1
Locus 2
V1
V2
ters
csf1po
fga
2
3
7
d18s51
d8s1179
2
4
7
csf1po
tpox
2
3
7
d18s51
fga
2
3
7
d13s17
d16s539
2
3
9
d18s51
tpox
4
5
7
d13s17
d1s80
2
3
9
d18s51
vwa
2
3
7
d13s17
d21s11
2
3
9
d1s80
fga
3
4
7
d13s17
d5s818
2
3
9
d21s11
d5s818
2
3
9
d13s17
d7s820
2
3
9
d21s11
d7s820
2
3
9
d13s17
fga
3
4
7
d21s11
fga
2
5
9
d13s17
ho1
2
3
9
d21s11
tho 1
2
3
9
d13s17
vwa
2
3
9
d21s11
vwa
2
3
9
d16s539
d1s80
2
3
9
d3s1358
fga
2
3
7
d16s539
d5s818
2
3
9
d3s1358
tpox
2
3
7
d16s539
d7s820
2
3
9
d5s818
d7s820
2
3
9
d16s539
fga
4
5
7
d5s818
tho 1
2
3
9
d16s539
tho 1
2
3
9
d5s818
vwa
3
4
7
d16s539
vwa
2
3
9
d7s820
d1s80
2
3
9
d18s51
d1s80
4
5
7
d7s820
d8s1179
2
3
9
d18s51
d21s11
2
3
7
d7s820
vwa
2
4
7
d18s51
d3s1358
2
3
7
d8s1179
fga
3
4
7
d18s51
d5s818
2
3
7
vwa
fga
2
3
7
EXAMPLE 16
Cluster Formation
The allele frequency distributions for the 2-loci combinations that yielded good clusters were examined to discover the reason behind their clusterability. It was found that those loci with allele probability concentrated at just a few alleles (2 to 4) are good candidates to give good clusters. The main reason is that with just a few alleles possible, the joint 2-loci allele distribution tends to concentrate in those allele pairs with relatively high probability of occurrence; ( FIG. 30 , 3010 ). Thus less but more distinct clusters tend to be formed. FIGS. 14 and 15 show the relative frequency of occurrence of the alleles at the d13s317 and d16s539 locus, respectively. Notice that alleles 11 and 12 in both loci have a much higher probability of occurrence. FIGS. 16 and 17 show the joint 2-allele frequency distribution for the d13s317 and d16s539 locus respectively. It is noted that only a few of the allele pairs have relatively high probability of occurring. This distribution pattern is to be contrasted with one where the majority of the allele have some probability of occurring but none is much higher than others. FIG. 18 shows the joint 2-loci allele-pair probability density for the d13s317 and d16s539 loci. Again, it is observed that most probability densities are concentrated at a few selected allele pairs, corresponding to those alleles with relatively high probability of occurring within each locus.
EXAMPLE 17
Interpreting SVD of Data Exhibiting Good Clusterability
Consider the allele distribution patterns in a large DNA STR data set. If for a specific locus, the probability densities concentrate in only a few, for example 3 out of 10, alleles, then the majority of the profiles in this data set will have alleles for that locus, corresponding to those with high probability densities. However, some, though in the minority, will still have alleles with low probability densities. Thus, the variance among the profiles associated with this locus will be higher than those where a large number of alleles have comparable but low probability densities. The large variance exhibited by this part of the data will be picked up by the leading principal components of the original data matrix. Recall that the principal components of a matrix X are given by the right singular vectors of X, after SVD (the columns of the matrix, V, from Eq. 1). For a matrix without any column mean centering, the first principal component generally gives just the average of the overall data, and therefore is not useful in differentiating between the points. The second principal component, therefore, is the one that gives the direction along which the variance exhibited by the original data matrix is maximum; the third principal component gives the direction that captures the next maximum variance, after the component along the first and second principal component have been subtracted off from the original data matrix.
As a result of the above reasoning, the first few leading principal components after the first, should be contributed heavily by those original variables (i.e., the alleles) that have the concentrated allele probability densities. FIGS. 19 and 20 show the make up of the second and the third principal components of the 10,000 profiles at the d13s17 and the d16s539 loci.
EXAMPLE 18
Interpreting the Principal Components
It is clear from the FIGS. 19 and 20 that the most significant alleles in principal component 2 are alleles 11 and 12 of d13s317, and the most significant for principal component 3 are alleles 11 and 12 of d16s539. Alleles 11 and 12 of d16s539 also contribute some to PC2, and alleles 11 and 12 of de13s317 also contribute some to PC3. Notice the opposite signs of alleles 11 and 12 of each locus in each PC. What this means is that, if a cluster of the scores of the DNA profiles projects highly onto the positive direction of PC2, then most members within this cluster have the presence of allele 12 (the second tall bar of FIG. 19 ) of d13s317, the presence of allele 11 of d16s539 (the first tall bar of d16s539 of FIG. 19 ), the absence of allele 11 in the first locus, and the absence of allele 12 in the second locus, respectively, since the signs associated with the latter pair are negative.
It was observed that cluster 9 from the scores plot of FIG. 13 projects highly along the positive direction of PC2. In FIG. 21 it is evident that in cluster 9, “all” of the members have allele 12 of the d13s317 locus, as well as allele 11 of the d16s539 locus. Further, none of the profiles has allele 11 of the first and allele 12 of the second locus. With similar reasoning, it is observed that cluster 7 projects heavily along the negative direction of the third principal component. This is interpreted to be that the members in this cluster would have allele 11 of both loci, and the absence of allele 12 in both loci. In fact, 100% of the members are this way. Notice that cluster 5 projects almost to the dead center of the origin. This is interpreted to be that members in this cluster either have both alleles or neither allele for each locus, so that the effects of the elements of the principal components for each locus cancel. As seen in FIG. 21 , this is the case.
EXAMPLE 19
Clustering by k-Means and Differentiation of Clusters
The nine distinct clusters can be established analytically by the k-means cluster algorithm. Clusters identified by k-means were validated by visual inspection. Memberships within each cluster were analyzed to get at the similarity among the members; ( FIG. 30 , 3010 ). FIG. 21 shows a plot of the fraction within each cluster possessing each allele. It is observed that clusters differ in the combination of alleles at each of the 2 loci that are dominant (allele 11 and 12 of both loci). For instance, members of cluster 1 all have the 5th allele of the d13s317 locus (allele 11) and the 8th allele (17−9=8; d13s317 has 9 alleles) of the d16s539 locus (allele 12). From the make up of the principal components, the projections of each clusters onto each principal component can be predicted by looking at the presence or absence of these alleles in the members of the clusters.
Because the most probable alleles for the d13s locus are alleles 11 and 12, and the most probable alleles for d16s539 are alleles 11 and 12 (or index number 16 and 17 in FIG. 21 below), the clusters correspond to profiles with various combinations of presence or absence of these dominant alleles at these four positions. Table 3 shows the combinations of these four dominant alleles in each of the nine clusters, based on the plots shown in FIG. 21 . The assignment of the allele distribution in these four dominant alleles in each of these nine clusters as well as the factor that caused the points to cluster this way is further elaborated below.
From Table 3, Boolean expressions can be written that form logical tests on the data to determine cluster assignment; ( FIGS. 30 , 3010 and 3020 ). For example, a Boolean expression testing for membership of a DNA profile in cluster 1 is “(d13s317-allele11) and not (d13s317-allele12) and not (d16s539-allele11) and (d16s539-allele12)”, where the terms in parentheses are logical variables that are true if the corresponding allele is present and false otherwise. A more complex example is the Boolean expression testing for membership in cluster 5: “(((d13s317-allele11) and (d13s317-allele12)) or not ((d13s317-allele11) or (d13s317-allele12))) and (((d16s539-allele11) and (d16s539-allele12)) or not ((d16s539-allele11) or (d16s539-allele12)))”. This expression requires both alleles from each locus to be either present or absent in order to be true. Boolean expressions can be rewritten in various forms and simplified according to methods that are well known and practiced in the fields of Boolean algebra and logic circuit design; ( FIGS. 30 , 3030 and 3040 ).
Table 3 can also be utilized to form a decision tree that sequentially applies tests for the presence or absence of alleles at specific loci using the methods of inductive inference that were pioneered by J. Ross Quinlan [13] and are well known and practiced in the fields of computer science and engineering. In this case, each node of the database tree that utilizes clusters derived from the multivariate statistical analysis method would contain a decision tree specifying the sequence of tests to be applied to DNA profile targets at that node, and the database tree can be rewritten by expanding these nodes and incorporating the decision tree's nodes into the database tree; ( FIG. 30 , 3030 ).
TABLE 3
The presence (1) or absence (0) of alleles 11 and 12 in the d13s and
d16s loci for each scores cluster as shown in FIG. 13; (FIG. 30, 3040).
D13s17
D13s17
D16s539
D16s539
Cluster
allele 11
allele 12
allele 11
allele 12
1
Yes(1)
No(0)
No(0)
Yes(1)
2
Yes(1)
Yes(1)
No(0)
Yes(1)
2
No(0)
No(0)
No(0)
Yes(1)
3
No(0)
Yes(1)
No(0)
Yes(1)
4
Yes(1)
No(0)
No(0)
No(0)
4
Yes(1)
No(0)
Yes(1)
Yes(1)
5
Yes(1)
Yes(1)
Yes(1)
Yes(1)
5
Yes(1)
Yes(1)
No(0)
No(0)
5
No(0)
No(0)
Yes(1)
Yes(1)
5
No(0)
No(0)
No(0)
No(0)
6
No(0)
Yes(1)
No(0)
No(0)
6
No(0)
Yes(1)
Yes(1)
Yes(1)
7
Yes(1)
No(0)
Yes(1)
No(0)
8
No(0)
No(0)
Yes(1)
No(0)
8
Yes(1)
Yes(1)
Yes(1)
No(0)
9
No(0)
Yes(1)
Yes(1)
No(0)
EXAMPLE 20
What Makes the Points Cluster
The consequence of having the allele probability densities concentrated in just a few alleles of a locus is now analyzed. As presented previously, the SVD of a matrix decomposes a data set into its mutually orthogonal components arranged in decreasing order of the amount of variance carried. Each scores vector is obtained by multiplying each DNA profile (a row of the data matrix, X) by the columns of the V matrix of Eq. 1 above. The columns of V are the principal component vectors. The ith element of a scores vector represents the inner product of that profile with the ith column of V. Table 4 shows the make up of the V2 and V3 vectors (the second and third principal components). Note that the 5th and 6th (allele 11 and 12 of d13s317) as well as the 16th and 17th (allele 11 and 12 of d16s539) components in each vector are dominant (but have opposite signs with each other) with the highest absolute values among all the elements. The significance of this was explained in the previous sections.
During the projection step, the inner product of a row of the DNA profile matrix with each of these V column vectors is formed to produce the scores vector associated with that DNA profile. Recall that a row of the DNA profile consists of 1's and 0's, with a 1 indicating the presence of that allele whose position the 1 occupies. Therefore, in forming the inner product, if a 1 is present at the 6th and 16th positions (corresponding to allele 12 of the d13s locus and allele 11 of the d16s locus) and a 0 is present at the 5th and the 17th positions (corresponding to the absence of allele 11 and allele 12 of d13s and d16s respectively), then the resultant inner product is going to be the highest in the positive sense, of all possible allele presence/absence pattern. The other elements of the V vector are insignificant because their magnitudes are significantly smaller than these four dominant ones. In contrast, if the opposite is true in that the patterns of 1's and 0's are reversed in these four alleles, then a score with the highest value in the negative sense will result. If a 1 is present in only one of the four dominant alleles then an intermediate number will be formed upon taking the inner product. The inner product with V2 gives the projection onto the 2nd principal component, and thus the x-axis coordinate in the 2-d scores plot. The inner product with V3 gives the projection onto the 3rd principal component, and thus the y-axis coordinate in the same plot. Therefore, all profiles with a similar distribution of 1's and 0's among these four dominant allele positions will be projected close to each other, forming a cluster. Profiles with 1's present in only one of the four dominant alleles will be projected into separate and distinct groups intermediate between the two extreme clusters. Profiles with 0's present at all four of these dominant allele positions will project into a cluster close to the origin.
The non-dominant components of V2 and V3 contribute “noise” that causes diversity among the points in each cluster. Cluster assignment is determined by the dominant components. These dominant components correspond to specific alleles whose presence or absence determine cluster membership. A manual or automated procedure can be utilized to determine which loci pairs will exhibit good clusters. The preferred pairs of loci are those that have few dominant components in V2 and V3. A second discovery is that the PCA method tends to produce clusters of roughly equal size. This is a consequence of the relative magnitudes of the probability densities over the alleles at each locus and the grouping of patterns of the alleles that correspond to the dominant components. The PCA method tends to produce groupings of allele patterns that result in clusters of roughly equal size. This property is important because it leads to the generation of balanced database trees, and thus tends to minimize average and worst-case search times.
TABLE 4
The second (V2) and third (V3) principal components of
the PCA model for d13s17 and d16s539 profiles.
Entry
Locus
Allele
V2
V3
1
d13s17
7
0
0
2
d13s17
8
−0.030463678
0.015674884
3
d13s17
9
0.014273974
−0.02612085
4
d13s17
10
0.002730887
0.006265153
5
d13s17
11
−0.60159885
−0.31240033
6
d13s17
12
0.61424995
0.40528092
7
d13s17
13
0.01506822
−0.027059415
8
d13s17
14
0.008189252
−0.002920761
9
d13s17
15
0.00040002
0.00072532
10
d16s539
5
−3.96254E−16
1.24058E−16
11
d16s539
6
−1.21109E−16
3.920160E−17
12
d16s539
7
3.16893E−16
−1.01547E−16
13
d16s539
8
0.00016862
−0.005327745
14
d16s539
9
−0.009021359
0.035054583
15
d16s539
10
0.010145883
0.009643393
16
d16s539
11
0.36385758
−0.61572765
17
d16s539
12
−0.3559744
0.59259863
18
d16s539
13
−0.006374183
0.068562668
19
d16s539
14
0.002505632
0.009997444
20
d16s539
15
−0.000962222
0.000468172
Scaling
0.015208802
0.015862441
factor
The center of each cluster is the center of gravity of the swarm of points in that cluster. Table 5 shows where the centers are with respect to the 2-d scores plot of FIG. 13 . Based on the above rationale for formation of the clusters, the approximate centers of the nine clusters as observed in the scores plot of FIG. 13 can be predicted from the set of all possible 1's and 0's distribution among the four dominant allele positions. The prediction can be checked against the true centers of the clusters. This is explained in the following section.
TABLE 5
The coordinates of the centers of the nine clusters shown in FIG. 13.
Cluster Centers
x
y
−0.0168
0.0054
−0.0062
0.0116
0.0045
0.0179
−0.0105
−0.0052
0.0001
0.0011
0.0108
0.0074
−0.0042
−0.0159
0.0064
−0.0096
0.0171
−0.0033
EXAMPLE 21
Testing the Theory of Clustering by Predicting the Approximate Centers of the Clusters
Table 6 shows all the possible 1-0 distribution patterns at the four dominant allele positions. The approximate predicted x and y coordinates for the cluster centers are calculated by multiplying the corresponding 1's and 0's at the four dominant allele positions with their counterpart values in the V1 (to get the x coordinate) and V2 (to get the y coordinate) vectors which were shown in Table 3 previously. This is followed by a normalization step in which the previous products are multiplied by the scaling factors shown at the bottom of Table 5, in order to arrive at the Mahalanobis scores. These scaling factors correspond to the reciprocals of the 2nd and 3rd singular values of the SVD of the original data matrix, X. The predicted approximate coordinates for the cluster centers are shown at the rightmost two columns of Table 5. These points are plotted as the ‘o’ points in FIG. 22 . The true cluster centers are also plotted in FIG. 22 , as the ‘*’ points. It is evident that the two sets are very close. All profiles in the original 10,000 profile set with identical allele distribution pattern in these four dominant allele positions will map to the same cluster. They will differ from each other somewhat, due to the presence or absence of alleles at other allele positions, which play a minor role in determining the coordinates of the corresponding profile in the 2-d scores plot. All possible allele distribution patterns in the four dominant positions fall into a total of nine clusters, as shown in Table 3 above. This experiment supports the explanation rendered above in regard to the formation of clusters in the 2-d scores space.
In summary, loci with allele probability densities concentrating at just a few alleles will give rise to V vectors with preferentially big values (in the absolute value sense) at just a few positions corresponding to the allele positions with high densities. (The fact that both alleles 11 and 12 in the d13s and d16s loci are the dominant alleles are just a coincidence.) As a result, distinct clusters will form, separable by the presence or absence of alleles at these dominant allele positions.
TABLE 6
The presence (1) or absence (0) of alleles at the four dominant allele
positions and the approximate cluster center coordinates calculated
from the 1-0 allele distribution pattern. See text for calculation of these
approximate coordinates.
d13s17
d16s539
Projections
N
11
12
11
12
x
y
1
0
0
0
0
0
0
2
0
1
0
0
0.009342
0.006429
3
1
0
0
0
−0.00915
−0.00496
4
1
1
0
0
0.000192
0.001473
5
0
0
0
1
−0.00541
0.0094
6
0
1
0
1
0.003928
0.015829
7
1
0
0
1
−0.01456
0.004445
8
1
1
0
1
−0.00522
0.010873
9
0
0
1
0
0.005534
−0.00977
10
0
1
1
0
0.014876
−0.00334
11
1
0
1
0
−0.00362
−0.01472
12
1
1
1
0
0.005726
−0.00829
13
0
0
1
1
0.00012
−0.00037
14
0
1
1
1
0.009462
0.006062
15
1
0
1
1
−0.00903
−0.00532
16
1
1
1
1
0.000312
0.001106
Scaling factor:
0.0152088
0.0158626
EXAMPLE 22
Clustering Analysis of a Real DNA STR Data Set
All the work reported above was done with 10,000 synthetic data profiles, generated based on the allele frequency distribution data for Caucasians as given in the CODIS data base. Recently, Budowle [10] released the STR profiles of six ethnic groups, each of which has around 200 samples. We tested whether PCA clusters from these data would project to the same clusters as that of the synthetic data, using the principal components from the latter to do the projection, and if the relative sizes of the clusters were maintained; ( FIGS. 30 , 3010 and 3020 ). Therefore, a small Caucasian sample data set from one of the six real DNA sample set was chosen for further analysis. This was done to determine whether or not new data inserted in the database would tend to degrade the balanced structure of the database tree and thus adversely affect mean and worst case search times.
The sample set was first converted to the binary representation format, with 1's and 0's. The corresponding allele information in the d13s317 and d16s539 loci was extracted. This was followed by computing the scores matrix onto the 2nd and 3rd principal components of the large synthetic data set. FIGS. 23 and 24 show the results. In FIG. 23 , the scores points from the large data set are overlaid on top of the scores points from the small data set. FIG. 24 shows the same thing except in this plot, the scores from the small sample set are overlaid on top of those of the large sample set. The black points depict the scores from the small sample set. Since there are only 176 of them, they do not completely cover the 10000 score points from the large data set. It is evident that the plotted scores from the small data (which are mapped to the same 2-d coordinates in a cluster as the scores from the large data set and are plotted as darker dots) are completely covered by those of the large data set (the dark gray points). This was interpreted to mean that there is no profile present in the small real DNA sample set that is not present in the large synthetic data set. This complete coverage is not always the case. Studies using other 2-loci combinations sometimes yield incomplete coverage. In all instances studied to date, however, the plotted 2-d coordinates for points in the small datasets were easily associated with clusters identified using the synthetic data set; ( FIG. 30 , 3020 ).
Next, estimates of the probability densities associated with the various clusters are derived. We identified which profiles from the small sample data set are in each of the nine clusters. We then calculated the fraction of the sample population that are within each of the nine clusters. FIG. 25 shows the comparison between the two data sets. The first bar of each pair of bars represents that from the small sample set, while the second bar denotes that of the large data set. To a first level approximation, the relative fractions are comparable between the two sets. The fraction of people in each cluster indicates the approximate fraction of people possessing the particular combination of the alleles at the dominant allele positions, thus the relative frequency of the occurrence of those dominant alleles in the associated locus. Note that the trend of the variation of the height of the bars for both sets are similar, except for that of the last cluster. It was concluded at this point that the two data sets have similar allele frequency distribution at these two loci. An important observation is the relative frequencies indicate that the sizes of the clusters are balanced in both data sets. This implies that addition of the data from Budowle to a database containing the synthetic data will not cause a database tree that utilizes clustering for the (d13s17, d16s539) locus pair to be unbalanced. Thus, search times will not be adversely affected.
EXAMPLE 23
Summary for the Clusterability of Profiles by the Principal Component Analysis Approach
This method can be extended by either (a) using more than two loci or (b) using more than two principal components (or both) to form clusters. It is possible, however, to utilize too much information, in which case clustering will not be achieved. For example, the use of PCA methods to analyze allele information for 16 loci simultaneously does not exhibit clustering. Thus, an important discovery of the inventors is that it is advantageous to limit the application of PCA methods to a portion of the available information to achieve good clustering results. In the work illustrated here, the information was limited to allele data for two loci. In this case, 40 out of 120 possible two-loci combinations exhibited good clustering properties, as listed in Table 3.
It is firmly established that DNA STR profiles can be partitioned into distinct clusters using the PCA approach. The partition is based on the allele distribution pattern at 2 loci. Certain 2-loci choices yield much better clustering than others. The factors that determine good clustering and the reason for the clustering have been presented and discussed. Successive partitioning using a different 2-loci combination approach at each round will reduce very quickly the members present within each resultant cluster. Partitioning by PCA clustering can be inserted into a suitably chosen non-terminal Node object of the database tree structure, for searching for matching profiles against a target profile; ( FIG. 30 , 3040 ). After passing through this node, it is expected that the number of candidate profiles for search will be reduced by approximately one order of magnitude. (Seven to nine clusters usually result from PCA clustering in which the clusters are about equal in size.)
EXAMPLE 24
Performance Analysis
The existing FBI CODIS database search engine requires approximately 5 seconds to search 100,000 DNA profile records for matches. In comparison, a database of synthetic DNA profile data was created using the statistical information provided with the FBI CODIS database. This database contained 400,000 DNA profiles and required a database tree with 13 levels and 13,180 Node objects. The memory required to store the tree was 218 Mbytes. The time required to load the database from an ASCII file that contained descriptions of the DNA profiles was 19 minutes 22 seconds. Search times for the test cases that have been run to date on the 400,000 profile database range from 1,200 microseconds to 4,200 microseconds, an improvement of greater than a factor of 1,000 over the CODIS implementation. These times are for searches for exact matches.
Additional tests were made using a database of 100,000 DNA profiles. For each test a DNA profile was randomly selected from the database and used to construct a search request. Exact matches were required. Over 5,019 runs the mean time required to complete a search and retrieve the matching sample(s) was 2,132.6 microseconds. Of the 5,019 runs, 98.5% of the searches completed in less than 5,000 microseconds. A histogram showing the distribution of times required to perform the search is shown in FIG. 26 .
When locus data are missing the search times increase. For a single target DNA profile match times increased from approximately 1,700 microseconds to 4,200 microseconds on a database of 10,000 samples. When matching is allowed on all but a single locus search times increased by approximately an order of magnitude to 17,000 microseconds. Tests were also conducted when equivalent alleles were defined, but are not directly comparable to the base case because a database of 1,000 DNA profiles was used. Searches required approximately 2,300 microseconds.
The method of database construction maintains a well-balanced database tree. FIG. 27 shows the graph of the tree for a database holding 100,000 DNA profiles with a maximum of 100 profiles stored at any leaf node. The tree has a maximum depth of 11 (levels 0 through 10) with most branches having a length of 7 to 9. Similar results have been obtained for 400,000 stored DNA profiles where the tree's maximum depth was 13. The balanced characteristic of the tree is important because it determines average and worst case search time. If the tree becomes unbalanced then a substantial fraction of Search Requests will require the descent of relatively long branches and will therefore require additional time.
EXAMPLE 25
Parallel Database Design and Hardware Platform
The database tree methods described above can also be implemented in parallel or by using multi-threaded software. The parallel implementation executes Search Engine and Search Queue objects on each host, with at least as many Search Engine objects as there are processors on a host. A root host is used to accept Client requests and create a Search Client object to handle each request. A critical component of the parallel implementation is the method used to balance the work load across the set of available hosts and processors. This method is distributed; it must run on each host. The method also responds to changing load patterns on the hosts, giving faster hosts more work. The method is reconfigured in the event of host failure(s).
Preferably, each host is allowed to maintain information on the population of available parallel virtual machine (PVM) hosts, measurements of their current loads (Search Queue lengths), and measurements of their capacities. Each host is responsible for gathering its statistics and broadcasting this information to the other participating hosts. As Search Queues become unbalanced, unprocessed Search Requests are exchanged to bring them back into balance. This exchange occurs randomly with a stochastic selection method utilized to determine the recipient of each exchange. In this manner control of the load balancing method equates to control of the probabilities of host selection. These probabilities are preferably proportional to the difference between that host's capacity and its load, weighted by the total of these differences over all hosts. A time constant is utilized to avoid excessive oscillations in host loading.
Two hardware platform options can be employed as hosts for the parallel database implementation. One utilizes generic PC hardware operating under the Linux operating system; the other utilizes a Sun Microsystems HPC 10000 server and the Solaris operating system. Both utilize the Parallel Virtual Machine (PVM) software [7] package to coordinate interprocess communications and synchronization. An asynchronous transfer mode (ATM) interconnect can also be used for the generic PC implementation, utilizing OC-12c (622 Mbps) connections between equipment racks and OC-3c (155 Mbps) connections within each rack. The configuration is scalable from 8 to 128 processors, with two additional control processors, in increments of 16 processors. A Control Rack houses a high performance ATM switch, such as the Fore Systems ASX-1200, configured in a star topology with OC-12c links to the PC Racks. The control rack also houses the control processors, a tape backup subsystem, a video and keyboard switch, and dual uninterruptable power supplies (UPS). A variation of this implementation is to replace the ATM interconnect with Fast Ethernet, Gigabit Ethernet, or another networking approach. Combinations of networking approaches may be used. Performance is dependent on the approach. The approach described is preferred.
The generic PC implementation can contain from one to eight PC racks, each housing eight rack-mounted dual processor PCs, a midrange ATM switch such as the Fore Systems ASX-200, and an UPS. All PC processors are specified as 500 MHz Pentium IIIs, although it is preferable to use the fastest chipset available at the time for construction of the system. Each PC is configured with 512 MB to 1 GB of RAM, and 54 GB of hard disk space. Performance figures of merit for the system include 3.5TB (terabytes) of disk storage, 64-128 GB aggregate memory, maximum sustained aggregate interprocessor bandwidth of 10 Gbps (non-blocking), with a maximum per PC bandwidth of 155 Mbps and rack-to-rack of 1.24 Gbps (non-blocking in each case). The estimated peak floating point performance on the linpack parallel benchmark is 40-60 Gflops, with an estimated peak aggregate instruction rate of 64 GIPS, assuming 500 MHz processors. This implementation strategy is similar to the Linux Beowulf supercomputer clusters pioneered by NASA [8].
The Sun HPC 10000 server scales from 4 to 64 400 MHz SPARC processors, with a configuration of 4 processors per board and a maximum of 16 boards. Input/output subsystems are attached to each processor board, and a 102 Gbps processor interconnect is utilized with 10 Gbps bandwidth to memory. In excess of 60 TB of disk space can be configured. The HPC 10000 supports clustering with up to 4 HPC 10000's in a cluster. The platform supports both PVM and MPI. Linpack-parallel benchmark results for a 64 processor Sun HPC 10000 have been reported at 43.8 Gflops. Sun claims a peak instruction rate of 100 GIPS.
Each configuration has its merits and disadvantages; however, either configuration can achieve the necessary performance for the national CODIS database. The Sun solution is probably substantially more costly; however, Sun offers maintenance and support contracts. A potential disadvantage of the Sun configuration is the shared memory architecture with a 10 Gbps memory bandwidth limitation. The fully distributed generic PC implementation provides local memory for each processor; however, a disadvantage is setup latency across the ATM switches and contention for the 10 Gbps non-blocking bandwidth of the Fore ASX-1200 switch. A substantial long-term advantage of the generic PC solution is that processors can be readily swapped out at will and upgraded with newer technology. Replacement of failed units with spare rack-mountable computers is also easy, allowing repair as time and resources permit. The generic PC solution has the advantage of being able to track the continuing evolution of processor performance, which has historically provided a rough doubling of performance every 18 months. It is unclear whether similar upgrade paths will be available for the Sun HPC 10000 architecture.
Referring to FIG. 28 , there is shown an example of a fully developed parallel architecture implementation of the present invention. Panels 2800-1 to 2800-M are fully modular and can grow in increments of one panel to a full complement of M panels (eight of which are shown). Moreover, each panel 2800 comprises two or more processors 2820 such that a first panel may be built and additional panels added in stages as the architecture grows to meet increasing database size and traffic demand of queries and retrievals of the database. Panel 2801 is a control panel and provides control operations for panels 2800 - 1 to 2800 -M using one or more control hosts 2811 . Central module 2810 - 1 to 2810 -M of each panel comprises a bus control module providing data linking capabilities and bus control for coupling computer hosts on its panel to bus control module 2821 on control panel 2801 and through bus control module 2821 to control hosts 2811 and all other computer hosts 2820 of panels 2800 - 1 to 2800 -M. Each panel 2800 - 1 to 2800 -M comprises N processors 2820 - 1 to 2820 -N.
REFERENCES
1. T. H. Cormen, et al., Introduction to Algorithms , MIT Press (Cambridge, Mass.)/McGraw-Hill (New York). 1990.
2. A. Guttman, R trees: a dynamic index structure for spatial searching, ACM, 1984, 47-57.
3. T. Sellis, et. al., “The R*-tree: a dynamic index for multi-dimensional objects,” Tech. Rept. UMI-ACS TR 87 3, CS TR 1975, University of Maryland, February 1987, 1-24.
4. R. Agrawal, et al., Method and system for performing proximity joins on high-dimensional data points in parallel, U.S. Pat. No. 5,884,320, Mar. 16, 1999.
5. Message Passing Interface Forum, MPI: A Message-Passing Interface Standard, version 1.1, June, 1995. Also at http://www-unix.mcs.anl.gov/mpi/.
6. Universal Data Option for Informix Dynamic Server, version 9.14 for Windows NT and UNIX. Also at http://www.informix.com/informix/techbriefs/udo/udo.pdf.
7. A. Geist, A., PVM: Parallel Virtual Machine: A Users' Guide and Tutorial for Networked Parallel Computing . MIT Press. 1994.
8. Beowulf Project at CESDIR, http://cesdis1.gsfc.nasa.gov/linux/beowulf/, Center of Excellence in Space Data and Information Sciences, NASA Goddard Space Flight Center. 1998.
9. G. Strang, Linear Algebra and its Applications, 2nd ed., Academic Press, New York, 1980.
10. B. Budowle, et al., “Genotype profiles for six population groups at the 13 CODIS short tandem repeat core loci and other PCR based loci,” Forensic Science Communications , FBI Laboratory Division Publication 99-06, U.S. Department of Justice, Federal Bureau of Investigation. July 1999, V. 1, n. 2.
11. CODIS 5.1 GDIS Searching Specification (Draft), U.S. Department of Justice Federal Bureau of Investigation. Jul. 23, 1998.
12. J. T. Tou, et al., Pattern Recognition Principles , Addison-Wesley, Reading, Mass., 1992.
13. J. R. Quinlan, “Induction of decision trees,” Machine Learning 1:81-106, 1986.
14. M. W. Berry, et al., “Matrices, vector spaces, and information retrieval,” SIAM Review 41:335-362, 1999.
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A tree-structured index to multidimensional data is created using naturally occurring patterns and clusters within the data which permit efficient search and retrieval strategies in a database of DNA profiles. A search engine utilizes hierarchical decomposition of the database by identifying clusters of similar DNA profiles and maps to parallel computer architecture, allowing scale up past previously feasible limits. Key benefits of the new method are logarithmic scale up and parallelization. These benefits are achieved by identification and utilization of naturally occurring patterns and clusters within stored data. The patterns and clusters enable the stored data to be partitioned into subsets of roughly equal size. The method can be applied recursively, resulting in a database tree that is balanced, meaning that all paths or branches through the tree have roughly the same length. The method achieves high performance by exploiting the natural structure of the data in a manner that maintains balanced trees. Implementation of the method maps naturally to parallel computer architectures, allowing scale up to very large databases.
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FIELD
[0001] The present invention is related to a motor for a vehicle that drives a railroad vehicle, and is particularly related to the configuration of an outer fan.
BACKGROUND
[0002] Generally, when a motor gets heated due to the heat generated during the passage of electric current, the deterioration of an insulator is accelerated and causes a decrease in longevity or efficiency. Hence, it is necessary to cool down the inside of the motor. Particularly in recent years, there has been a development of totally-enclosed-fan-cooled motors that include an outer fan, which is fixed to a rotor shaft at the end lying on the outside of the housing, and an inner fan, which agitates the air inside the motor. Particularly, by taking into consideration the issue of maintenance from outside, it is common practice to fix the outer fan with bolts that are fitted by insertion in the direction of the rotor shaft.
[0003] In the conventional technology represented by Patent Literature 1 mentioned below, a fan that is fixed to a rotor shaft in an identical manner as described above rotates so as to let the outside air in and to let the heat out from the inside of the motor. As a result, the motor gets cooled down in an effective manner.
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: Japanese Patent Application Laid-open No. H05-300698
SUMMARY
Technical Problem
[0005] In the conventional technology represented by Patent Literature 1 mentioned above, the fan is bolted to a shaft retainer (stopper) or bolted to the end face of a rotor shaft. However, bolt insert holes formed on the fan have a larger diameter than the diameter of the bolts. For that reason, in case the rotor shaft is subjected to torque variation equal to or greater than the frictional force of the bolting, then the centers of the bolts shift with respect to the bolt insert holes. That sometimes leads to the loosening of the bolts, which eventually causes the bolts to break. In that case, the fan may get unfastened.
[0006] The present invention has been made to solve the above problems in the conventional technology and it is an object of the present invention to provide a motor for a vehicle that is configured in such a way that, at normal temperature, the fan can be easily taken out and, at a high temperature or at a low temperature, the fan can be prevented from skidding that may occur due to the torque variation of the rotor shaft.
Solution to Problem
[0007] A motor for a vehicle according to an aspect of the present invention installed in a railway train and having a fan that is mounted on a rotor shaft and that causes the outside air into the motor, the motor for a vehicle including: a stopper which functions as a positioning member for the fan in an axial direction, which is fixed in between a bearing supporting the rotor shaft and the fan inserted from one end of the rotor shaft, and which has a surface formed opposite to the fan so as to be fittable with the fan, wherein the fan is fixed by a fastening member, which is inserted toward the stopper in substantially parallel to the rotor shaft, and has a linear expansion coefficient set to be greater than linear expansion coefficients of the rotor shaft and the stopper.
Advantageous Effects of Invention
[0008] According to an aspect of the present invention, a fan, which is made from a material having a greater linear expansion coefficient than the linear expansion coefficient of a rotor shaft and a stopper, is made to fit in the stopper. Hence, at normal temperature, the fan can be easily taken out and, at a high temperature or at a low temperature, the fan can be prevented from skidding that may occur due to the torque variation of the rotor shaft.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a vertical cross-sectional view of a motor with a central focus on a fan.
[0010] FIG. 2 is a vertical cross-sectional view explaining a configuration of the motor fan according to a first embodiment.
[0011] FIG. 3 is a diagram illustrating a condition in which the motor fan illustrated in FIG. 2 is fixed to a rotor shaft.
[0012] FIG. 4 is a cross-sectional view taken along line A-A illustrated in FIG. 3 .
[0013] FIG. 5 is a diagram explaining a relationship between linear expansion coefficients and the brake torque.
[0014] FIG. 6 is a vertical cross-sectional view explaining a configuration of the motor fan according to a second embodiment.
DESCRIPTION OF EMBODIMENTS
[0015] Exemplary embodiments of a motor for a vehicle to the present invention are described below in detail with reference to the accompanying drawings. The present invention is not limited to these exemplary embodiments.
First Embodiment
[0016] FIG. 1 is a vertical cross-sectional view of a motor 100 with a central focus on a fan 30 ; FIG. 2 is a vertical cross-sectional view explaining a configuration of the fan 30 according to a first embodiment; FIG. 3 is a diagram illustrating a condition in which the fan 30 illustrated in FIG. 2 is fixed to a rotor shaft; FIG. 4 is a cross-sectional view taken along line A-A illustrated in FIG. 3 ; and FIG. 5 is a diagram explaining a relationship between the linear expansion coefficients and the brake torque.
[0017] It is illustrated in FIG. 1 that, in the motor 100 , the fan 30 is fixed to a rotor shaft 10 with bolts (fastening members) 40 , and a stopper 20 serving as a positioning member for the fan 30 in the axial direction is disposed in between the fan 30 and a bearing 50 .
[0018] Given below with reference to FIGS. 2 to 5 is the explanation related to a configuration of the fan 30 illustrated in FIG. 1 . The fan 30 has a boss section (a protruding section) 31 that fits, along the axial direction, in a recessed portion 21 of the stopper 20 for the bearing 50 . Besides, upon fitting in the stopper 20 , the fan 30 fits together with the rotor shaft 10 . Meanwhile, the rotor shaft 10 and the stopper 20 are made from, for example, iron; while the fan 30 is made from, for example, aluminum. Moreover, regarding the linear expansion coefficient of each member and regarding the transmission of rotary torque, the explanation is given later.
[0019] Given below are the dimensions of a contact portion in each member. Herein, the diameter in the lateral direction of the rotor shaft 10 (hereinafter, referred to as “rotor shaft diameter D”); the diameter of the recessed portion 21 of the stopper 20 (hereinafter, referred to as “fan-abutting-face diameter ds”); the diameter of that portion of the fan 30 which makes contact with the rotor shaft 10 (hereinafter, referred to as “rotor-shaft-abutting-face diameter df 1 ”); and the diameter of the boss section 31 that fits in the recessed portion 21 of the stopper 20 (hereinafter, referred to as “stopper-abutting-face diameter df 2 ) are illustrated.
[0020] The bolts 40 illustrated in FIG. 4 are threaded into the stopper 20 through bolt insert holes that are formed on the fan 30 . With the bolts 40 , the fan 30 and the stopper 20 are fixed. Meanwhile, the stopper 20 is fit to the rotor shaft 10 by means of shrink fitting.
[0021] In the A-A cross-sectional view illustrated in FIG. 4 , the rotor shaft 10 , the boss section 31 , and the stopper 20 are conceptually illustrated to be in a fitted condition at normal temperature. A small gap is illustrated in between the fitted portions of the members. Herein, the boss section 31 is disposed on the outside of the rotor shaft 10 and on the inside of the stopper 20 . That is, the boss section 31 is sandwiched between the rotor shaft 10 and the stopper 20 .
[0022] In between the inner periphery of the boss section 31 and the outer periphery of the rotor shaft 10 , a gap is illustrated that is present at normal temperature. In an identical manner, in between the outer periphery of the boss section 31 and the inner periphery of the stopper 20 , a gap is illustrated that is present at normal temperature. The motor 100 according to the first embodiment is configured in such a manner that, due to the difference in the linear expansion coefficients of the members at a low temperature or at a high temperature, the contact pressure at the fitted portions is increased so as to vary the brake torque between the members.
[0023] That point is explained below in details. With reference to FIG. 2 , for example, when the ambient temperature around the fan 30 decreases, then the rotor-shaft-abutting-face diameter df 1 becomes smaller than the rotor shaft diameter D because the contraction amount of the fan 30 (made from, for example, aluminum) is greater than that of the rotor shaft 10 (made from, for example, iron). Thus, it results in an increase in the contact pressure between a rotor shaft abutting face 32 and the rotor shaft 10 .
[0024] With the rise in the ambient temperature around the fan 30 , the stopper-abutting-face diameter df 2 becomes greater than the fan-abutting-face diameter ds because the contraction amount of the fan 30 (made from, for example, aluminum) is greater than that of the stopper 20 (made from, for example, iron). Thus, it results in an increase in the contact pressure between the boss section 31 and the stopper 20 .
[0025] Explained below with reference to FIG. 5 is the relationship between the linear expansion coefficients and the brake torque using calculating formulae. Firstly, it is defined that the portion over which the rotor shaft 10 and the boss section 31 make contact has a diameter d 1 , the portion over which the boss section 31 and the stopper 20 make contact has a diameter d 2 , and the stopper has a diameter d 3 . In this case, a linear expansion coefficient αAl of aluminum and a linear expansion coefficient αFe of iron can be expressed as given in Expression (1).
[0000] linear expansion coefficients:αAl>αFe (1)
[0026] A temperature change ΔT can be expressed as given in Expression (2).
[0000] temperature change:Δ T=T−Tr (where, Tr :normal temperature) (2)
[0027] A difference δ between the linear expansion coefficient αAl of aluminum and the linear expansion coefficient αFe of iron can be expressed as given in Expressions (3) and (4).
[0000] δ d 1 =(αAl−αFe) d 1 ΔT (3)
[0000] δ d 2 =(αFe−αAl) d 2 ΔT (4)
[0028] When the temperature change ΔT>0, the difference δ between the linear expansion coefficient αAl of aluminum and the linear expansion coefficient αFe of iron can be expressed as given in Expressions (5) and (6).
[0000] when Δ T> 0, δd 1 >0, δd 2 <0 (5)
[0000] when Δ T< 0, δd 1 <0, δd 2 >0 (6)
[0029] Thus, at a high temperature, aluminum and iron abut against each other (being in a shrink-fit condition) at the diameter d 2 of the portion over which the boss section 31 and the stopper 20 make contact. Moreover, at a low temperature (for example, when the motor 100 is started at a place in a cold weather region), aluminum and iron abut against each other (being in a expansion-fit condition) at the diameter d 1 of the portion over which the rotor shaft 10 and the boss section 31 make contact.
[0030] A contact pressure PQ of aluminum and iron can be expressed as given in Expressions (7) and (8).
[0000] when Δ T > 0 ,
P Q = δ d 2 2 { 1 EAl · d 2 2 ( d 1 2 + d 2 2 d 2 2 - d 1 2 - vAl ) + 1 EFe · d 2 2 ( d 2 2 + d 3 2 d 3 2 - d 2 2 - vFe ) } where, EAl:Young's modulus of Al, EFe:Young's modulus of Fe, ν:Poission ratio (7)
[0000]
when
Δ
T
<
0
,
P
Q
=
δ
d
1
2
{
1
EFe
·
d
1
2
(
1
-
vFe
)
+
1
EAl
·
d
1
2
(
d
1
2
+
d
2
2
d
2
2
-
d
1
2
-
vAl
)
}
(
8
)
[0031] At the diameter d 2 of the portion over which the boss section 31 and the stopper 20 make contact, a brake torque T can be expressed as given in FIG. 9 . At the diameter d 1 of the portion over which the rotor shaft 10 and the boss section 31 make contact, the brake torque T can be expressed as given in Expressions (9) and (10).
[0000]
when
Δ
T
>
0
,
T
=
μ
P
Q
A
1
·
d
2
2
(
9
)
[0032] where, μ: friction coefficient
A 1 : lateral area of outer diameter d 1
[0000]
when
Δ
T
<
0
,
T
=
μ
P
Q
A
1
·
d
1
2
(
10
)
[0034] where, A 2 : lateral area of outer diameter d 2
[0035] In this way, the motor 100 according to the first embodiment is configured in such a way that, at a low temperature, the contact pressure PQ at the abutting portion between the rotor shaft abutting face 32 and the rotor shaft 10 increases thereby leading to the generation of the brake torque T between the rotor shaft 10 and the fan 30 . Moreover, the configuration is such that, at a high temperature, the contact pressure PQ at the abutting portion between the boss section 31 and the stopper 20 increases thereby leading to the generation of the brake torque T between the stopper 20 and the boss section 31 .
[0036] In contrast, in a conventional motor, for example, the fan is directly fixed to the rotor shaft by using the fastening force of bolts. In that case, as also described above in the technical problem section, the torque of the rotor shaft acts directly on the bolts. That may lead to the loosening of the bolts. Moreover, in another type of configuration, the fan is fixed by inserting bolts in the stopper that is fit to the rotor shaft by means of shrink fitting. In that case too, the torque of the rotor shaft acts directly on the bolts.
[0037] As described above, in the motor 100 according to the first embodiment, the fan 30 is made from a material having a greater linear expansion coefficient than the linear expansion coefficients of the rotor shaft 10 and the stopper 20 . Moreover, the boss section 31 of the fan 30 is sandwiched between the rotor shaft 10 and the stopper 20 . Hence, for example, at the temperature observed while running, in addition to the fastening force of the bolts 40 , it is also possible to apply the brake torque T in the rotating direction irrespective of whether the temperature is high or low. Consequently, for example, at the temperature when the maintenance of the fan 30 is done (i.e., at a normal temperature Tr), the fan 30 can be detached without difficulty. Moreover, if the bolts 40 become loose at a low temperature, the fan can still be prevented from skidding that may occur due to torque variation. Furthermore, since the load on the bolts 40 decreases, it becomes possible to reduce the number of the bolts 40 or to downsize the bolts 40 . Besides, since it is sufficient only to process the fitted portion between the stopper 20 and the boss section 31 , the configuration of the abutting portion of the fan 30 can be simplified. As a result, the fan 30 can become lighter in weight, can be installed in a smaller space, and can be manufactured at low cost.
Second Embodiment
[0038] In the motor 100 for a vehicle according to a second embodiment, the stopper 20 and the boss section 31 have a different shape. Explained below is a configuration of the fan according to the second embodiment. Meanwhile, the elements identical to those explained in the first embodiment are referred to by the same reference numerals and their explanation is not repeated. Only the difference in the configuration is explained below.
[0039] FIG. 6 is a vertical cross-sectional view for explaining a configuration of the fan 30 according to the second embodiment. As illustrated in FIG. 6( a ), the boss section 31 fits in a groove portion of the stopper 20 . With the boss section 31 , the stopper 20 , and the rotor shaft 10 configured in such a manner; at a high temperature, the outer periphery of the boss section 31 makes contact with the stopper 20 . Moreover, at a low temperature, the fan 30 makes contact with the rotor shaft 10 and the inner periphery of the boss section 31 makes contact with the stopper 20 .
[0040] As illustrated in FIG. 6( b ), a stopper boss section 33 has a shape that fits in a groove portion of the fan 30 . Thus, with the stopper boss section 33 , the stopper 20 , and the rotor shaft 10 configured in such a manner; at a low temperature, the fan 30 makes contact with the rotor shaft 10 and the outer periphery of the stopper boss section 33 makes contact with the fan 30 . Moreover, at a high temperature, the inner periphery of the stopper boss section 33 makes contact with the fan 30 .
[0041] As described above, in the motor 100 according to the second embodiment, the thickness of the fitted portion between the stopper 20 and the fan 30 is reduced as compared to the first embodiment. That makes it possible to reduce the difference between the brake torque T at the high temperature and the brake torque T at the low temperature.
[0042] Meanwhile, in the explanation according to the first and second embodiments, it is assumed that the rotor shaft 10 and the stopper 20 are made from iron and the fan 30 is made from aluminum. However, that does not have to be the only case. Herein, it is sufficient that the linear expansion coefficient α is set to be greater than the linear expansion coefficients α of the rotor shaft 10 and the stopper 20 .
[0043] Moreover, the linear expansion coefficient α of the rotor shaft 10 and the linear expansion coefficient α of the stopper 20 can also be set to have different values. For example as illustrated in FIG. 1 , the contact surface area between the recessed portion 21 and the boss section 31 is smaller than the contact surface area between the rotor shaft abutting face 32 and the rotor shaft 10 . However, if the linear expansion coefficient α of the stopper 20 is set to a value smaller than the linear expansion coefficient α of the rotor shaft 10 , the brake torque T at a high temperature can be secured. Meanwhile, the materials of the members need not be limited to aluminum and iron, and any other material can be used as long as the abovementioned relationship between the linear expansion coefficients α is established.
[0044] In the first and second embodiments, the explanation is given with reference to an outer fan of a totally-enclosed-fan-cooled motor as an example. However, the explanation is not limited to the totally-enclosed-fan-cooled motor or to the outer fan, and is also applicable to a motor other than a totally-enclosed-fan-cooled motor or to a fan other than an outer fan.
[0045] Moreover, in the first and second embodiments, the bolts 40 are used as the fastening members for the fan 30 . Alternatively, the fastening members are not limited to the bolts 40 as long as those fastening members can be threaded in the stopper 20 for fixing the fan 30 .
INDUSTRIAL APPLICABILITY
[0046] In this way, the present invention is applicable to a motor for a vehicle that drives a railroad vehicle, and is particularly suitable as an invention in which, at a normal temperature, the fan can be easily taken out and, at a high temperature or at a low temperature, the fan can be prevented from skidding that may occur due to the torque variation of the rotor shaft.
REFERENCE SIGNS LIST
[0000]
10 ROTOR SHAFT
20 STOPPER
21 RECESSED PORTION
30 FAN
31 BOSS SECTION
32 ROTOR SHAFT ABUTTING FACE
33 STOPPER BOSS SECTION
40 BOLT
50 BEARING
100 MOTOR
α LINEAR EXPANSION COEFFICIENT
D ROTOR SHAFT DIAMETER
df 1 ROTOR-SHAFT-ABUTTING-FACE DIAMETER
df 2 STOPPER-ABUTTING-FACE DIAMETER
ds FAN-ABUTTING-FACE DIAMETER
d 1 DIAMETER OF PORTION OVER WHICH ROTOR SHAFT AND BOSS SECTION MAKE CONTACT
d 2 DIAMETER OF PORTION OVER WHICH BOSS SECTION AND STOPPER MAKE CONTACT
d 3 STOPPER DIAMETER
T BRAKE TORQUE
Tr NORMAL TEMPERATURE
ΔT TEMPERATURE CHANGE
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A motor for a vehicle is installed in a railway train and has a fan that is mounted on a rotor shaft and that causes the outside air into the motor. The motor for a vehicle includes a stopper that is fixed in between a bearing, which supports the rotor shaft, and the fan, which is inserted from that side of the rotor shaft at which the bearing lies. The stopper is configured to fit with the fan. The fan has a linear expansion coefficient set to be greater than linear expansion coefficients of the rotor shaft and the stopper. The fan is configured to be fittable with the stopper using bolts that are inserted from outside toward the stopper.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The apparatus relates to the field of fuel-air mixture preparation for internal combustion engines. More particularly, it relates to fuel mixture preparation in which a λ or oxygen sensor is used in the exhaust system of the engine to provide a signal related to the presence of oxygen in the exhaust gas and permitting deductions as to the relative richness or leanness of the fuel mixture supplied to the engine. Typically, the λ-sensor signal is fed to a comparator where a comparison is made between the magnitude of the λ-signal and a local, possibly adjustable, set-point voltage. The output of the comparator is then fed to an integrator which engages a final control element in the mixture preparation system to adjust the fuel-air ratio.
2. State-of-the-Art
The use of so-called λ-sensors or oxygen sensors in the exhaust system of an internal combustion engine for providing an actual control value to control the fuel-air mixture is known. When such a sensor is used, the overall system may be identified in the following manner. The carburetor or fuel injection system together with the engine is the overall control system. In that system, the engine itself is the controlled variable and the mixture preparation system is the controller which receives an output signal from the λ-sensor that acts as the actual, operational value for the loop. The nominal or desired fuel-air ratios are determined on the basis of the rpm and the air flow rate aspirated by the engine. For example, fuel injection systems are known which inject fuel intermittently or continuously to the combustion chambers or the induction tube of the engine. One of the problems encountered in such control processes has been the fact that the time constant of the λ control is adjusted for optimum exhaust gas conditions, i.e., the time constant of the controller is held relatively small so as to permit a rapid response to changing operational conditions. However, and especially if the controller is capable of substantial adjustments, the engine often see-saws at idling, i.e., there are periodic rpm changes due to the fact that the time constant of the engine itself is not constant but depends on the engine speed. This means that when the engine runs relatively slowly, for example at idling, the engine time constant is increased due to the slower passage of gases through the engine. This type of increase in the engine response time or engine dead time leads to pronounced control oscillations unless the time constant of the control process is adapted to the changed conditions which occur when the engine idles.
OBJECT AND SUMMARY OF THE INVENTION
It is thus a principal object of the present invention to provide an apparatus for association with the mixture preparation system of an internal combustion engine for preventing control oscillations in such a system, especially at low engine speeds. It is a further and more particular object of the invention to change the time constant of the λ-controller in certain operational domains of the engine.
It is yet another object of the invention to change the time constant of the controller at low engine speeds.
These and other objects are attained according to the invention by providing a circuit which uses the time period which elapses between the zero crossing times of the λ-sensor signal and which includes a timing circuit. Depending on whether the period of zero crossings or the time constant of the timing circuit is larger, the apparatus of the invention switches an additional resistor into the timing components of an integrating circuit, thereby increasing the time constant at lower engine speeds. The apparatus according to the invention provides the advantage that the time constant can be changed in the idling domain of the engine so that control oscillations are substantially or completely suppressed even if the time constant, i.e., the response constant of the engine, changes. It is a particular advantage of the present invention that no additional mechanical connections to the throttle plate switch or other electrical lines to electronic control elements are required. This is possible because the invention is based on the recognition that the zero crossing time of the λ-sensor may be used as a measure for the effective response time of the engine. Accordingly, the apparatus of the present invention may be built with relatively little effort and at relatively low expense but nevertheless reliably prevents the occurrence of control oscillations in operational states where such oscillations would normally occur. Another advantage of the invention is that it may be adapted to widely different types of engine control systems.
The invention may be used in any type of mixture preparation systems, for example carburetors of varying construction and fuel injection systems.
The invention will be better understood as well as further objects and advantages thereof become more apparent from the ensuing detailed description of an exemplary embodiment taken in conjunction with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a circuit diagram of a preferred exemplary embodiment of a circuit according to the invention for changing the controller time constant of a λ control system;
FIG. 2 is a set of curves illustrating the occurrence of various potentials as a function of time in the circuit according to FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The circuit of which FIG. 1 is a schematic diagram is a preferred exemplary embodiment of a device which permits changing the time constant of a λ controller when certain operational conditions are encountered. The change of the time constant is performed primarily for suppressing possible control oscillations.
As already discussed, the overall system which includes the internal combustion engine, the mixture preparation system and the λ-sensor can be regarded as a control system in which the engine plays the role of the controlled variable whereas the mixture preparation system is the controller and the λ-sensor produces an actual value which is a measure of the composition of the mixture fed to the engine, i.e., of its air factor λ.
A control system of this type has a plurality of inherent time constants, one of these being for example the time constant of the controlled variable which may be regarded as that time period which must pass before a change exerted by the final control element at the input can be recognized as a change of the actual value by the sensor disposed downstream, i.e., in this case the λ-sensor. This time period will be referred to below as the "dead time" of the engine and its value depends on the prevailing operational state of the engine. The reason for this dependence is that the dead time will be relatively large if the throughput of gas through the engine is relatively small, as is the case at idling. Thus, when the engine idles, any change of the mixture is recognized by the λ-sensor relatively late. For this reason, it is possible that the dead time of the engine may approach the order of magnitude of the normal control time constant and may in fact exceed it. In the case, the controller so to speak lags the engine and, especially when the control adjustments are large, periodic changes in the fuel supplied to the engine may occur. Such periodic changes result in periodic engine speed changes at idling. A cyclic alternation of the engine speed at idling is sometime referred to as engine "sawing".
Turning now to FIG. 1, there will be seen a circuit consisting of several sub-circuits. The first of these sub-circuits is a comparator circuit 1 followed by a circuit 2 which is a timing circuit, feeding a control circuit 3. The control circuit 3 engages an output circuit 4 which would normally be connected to the final control element in the loop, for example a member of the fuel mixture metering system. The sub-circuit 4 includes a provision for changing the inherent time constant of the output circuit 4. Inasmuch as the basic response time, i.e., dead time of the controlled variable, i.e., the engine, cannot be changed, being due to the normal gas throughput through the engine, the present invention addresses the problem of this operationally dependent dead time by changing the time constant of the control loop if the engine enters a domain where pronounced control oscillations might occur. The controller which, in this case, is the carburetor or the fuel injection system, need not be discussed in detail for it is not a primary subject of the present invention. However, normally the output circuit 4 includes an integrator in which the rate of integration is a parameter which actually determines the controller's time constant. In FIG. 1, the integrator bears the reference numeral 5 and is represented only as a block. In the present case, the time constant of the integrator is determined by the combination of series-connected resistors R0 and R1. When both resistors are connected in series and are effective, the time constant of the integrator will obviously be larger. This can be illustrated by supposing that the integrator will contain at least one timing element, for example a capacitor, which is charged and discharged through the series-connected resistors R0 and R1. It is clear that this charging and discharging process will take longer the larger are the values of the resistor chain through which the charging and discharging current must flow. Thus it may be stated at the outset that in normal operation, when control oscillations are not expected, the resistor R0 is removed from the effective current path by short circuiting it with the collector-emitter path of a transistor T4. Thus, in the normal operation of the engine, the transistor T4 conducts as will be appreciated by noting that its base is connected to a resistor R2, in turn connected to the positive supply rail of the circuit, which causes the transistor T4 to conduct provided that the transistor T3 in series with the resistor R2 and connected on the emitter side to ground is blocked. The decision on whether the resistor R0 is to be included in the series connection of the timing elements of the integrator 5 is made on the basis of information obtained from the output of the λ-sensor or its subsequent comparator. This decision is made by a timing circuit 2 which receives its input signal from a comparator 11 which compares the λ-sensor signal from a λ-sensor 10 with a set-point value provided, for example, from a voltage divider composed of resistors R4 and R5 connected between the positive and negative supply lines of this circuit. The comparator 11 may be an operational amplifier and its output signal would follow a curve such as that illustrated schematically in FIG. 2a. This curve derives from the fact that the λ-sensor responds to the presence or absence of oxygen in the exhaust gas and its output voltage jumps abruptly from a low value of approximately 100 mV when the input mixture is lean (excess oxygen in the exhaust gas) to a value of approximately 900 Mv for a rich input mixture. The output voltage of the comparator is fed to the main components of the circuit 2 which constitute a monostable multivibrator whose time constant is chosen to be equal to the maximum time constant of the control system still permitting operation without control oscillations. The monostable multivibrator of circuit 2 is a so-called economy mono flip-flop and includes a transistor T1, the emitter of which is grounded or connected to a negative potential and whose collector is connected through a resistor R6 to the positive supply line. A voltage divider chain, consisting in this case of an adjustable resistor R7, a diode D1 connected to pass positive currents and a resistor R8, is connected between the positive and negative supply lines. The base of the transistor T1 is connected to the junction of the cathode of the diode D1 and the resistor R8. The output of the comparator 11 is coupled to the junction of the resistor R7 and the anode of the diode D1 via a capacitor C1.
Following the monostable multivibrator of circuit 2 is a control circuit including a transistor T2 connected in the usual manner which a collector resistor R10' and a base drain resistor R11. The circuit includes a further transistor T3 whose base is connected to the collector of the transistor T2 via a positive passing diode D2 and possibly a base resistor R12. A further capacitor C2 is connected between the junction of the resistor R12 and the anode of the diode D2 and ground. The circuit described so far operates as follows, as may be seen with the aid of FIGS. 2a through 2e. As already mentioned, the time constant of the monostable flip-flop 2 is adjusted to be equal to that engine response time or dead time which may be just tolerable and beyond which the circuit should be altered to accomodate a larger dead time so as to eliminate control oscillations. If the circuit 2 receives no triggering pulses, the transistor T1 is conducting due to the voltage received from the base voltage divider consisting of the elements R7, D1 and R8. This state corresponds to the stable state of the flip-flop. Negative-going edges of the comparator output voltage flip the circuit into its monostable or unstable state because the negative charge on the capacitor C1 blocks the diode D1 and thus also the transistor T1. Once the negative charge on the capacitor C1 has decayed through the adjustable resistor R7, the transistor T1 returns to its conducting state. The operation of the circuit of FIG. 1 will be better understood if it is remembered that, in normal operation, i.e., when the control loop time constant is sufficiently large with respect to the dead time of the engine, the transistor T4 is conducting. Thus, in such cases, the transistor T3 must be blocked, which in turn requires that the transistor T2 be conducting. The timing diagram 2b illustrates the time constant T 0 of the unstable state of the flip-flop. As long as that time T 0 is larger than the time which elapses between two successive zero crossings of the sensor voltage, i.e., the output of the comparator output voltage shown in FIG. 2a, the comparator output voltage will always trigger the flip-flop 2 in time so as to maintain it in its astable state and prevent its return to its stable state. This takes place as follows: During the positive half cycle of the comparator output voltage, i.e., from the time t 1 to the time t 2 , the transistor T1 conducts anyway so that its collector output voltage shown in FIG. 2b is substantially at ground potential. During this time, the positive output voltage from the comparator holds the transistor T2 conducting via the diode D3 so that T3 is blocked and T4 conducts, thereby keeping only the resistor R1 as the effective timing resistor in the circuit 4. However, during the negative half cycle of the comparator output voltage, i.e., from the time t 2 to the time t 3 , the transistor t 1 is placed into its blocking state while the flip-flop 2 is in its astable condition. Thus, the diode D3 blocks but the transistor T2 is kept conducting through the diode D4 which transmits a positive voltage from the collector of the transistor T1 to the base of the transistor T2.
If, however, the negative half cycle of the comparator output voltage, i.e., beginning at the time t 4 up to the time t 6 , happens to be longer than the time constant T 0 of the flip-flop 2 (given by T 0 =C1·R7) the flip-flop 2 returns to its normal stable state in which the transistor T1 conducts and the diode D4 is blocked. However, during the continuing negative voltage of the comparator, i.e., from the time t 5 to the time t 6 , the transistor T2 cannot be held in conduction even through the diode D3 so that it blocks during this time period (t 5 to t 6 ) and its collector delivers a positive voltage jump according to the curve 2c. This leads to a rapid charging of the capacitor C2 via the diode D2 which conducts when the transistor T2 is blocked. For this reason, the transistor T3 also conducts and places the base of the subsequent transistor T4 at a sufficiently negative potential so that T4 blocks and introduces the resistor R0 in series with the resistor R1 in the timing chain of the circuit 4. The discharge time constant of the capacitor C2 is so chosen that the transistor T3 will always conduct if the collector of the transistor T2 exhibits continuing positive pulses, i.e., if the dead time of the engine continues to be larger than the preset time constant T 0 of the flip-flop. For this reason the effective total resistance R=R 0 +R 1 is maintained until finally the flip-flop time constant T 0 is larger than the engine dead time so that the transistor T4 begins to conduct again. The voltage at the capacitor C2 is shown in curve 2d and the curve 2e shows the voltage at the collector of the transistor T3.
As already mentioned above, the apparatus according to the present invention may be used in association with any type of mixture preparation system, for example those using carburetors, fuel injection systems and the like. If carburetors are used, the fuel nozzle cross sections may be changed by the controller or some other fuel delivering mechanism can be engaged. The invention is especially useful in controlling the exhaust gas recycle rate in mixture preparation systems, for controlling the flow through bypass conduits or to provide additional adjustment of the duration of fuel injection control pulses in electronic fuel injection systems, for example by engaging the multiplying stage of such systems. In general, the use of λ-sensor control systems and the associated circuitry according to the present invention may be used in any systems or engines in which combustible fuel is delivered to the combustion regions of the engine or system by means of vacuum or under pressure.
The foregoing relates to merely preferred exemplary embodiments of the invention, it being understood that other embodiments and variants thereof are possible within the spirit and scope of the invention.
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A circuit to be used in association with a fuel mixture control system which includes an oxygen sensor in the exhaust system to determine the relative richness of the combustible mixture. When the engine operates at low speeds, its control response time becomes large due to decreased engine throughput. In order to prevent control oscillations from occcurring under these conditions, the time constant of integration of the oxygen sensor control loop is changed to accommodate to the longer engine response time. For this purpose, the zero crossings of the oxygen sensor signal are compared with the unstable time constant of a multivibrator and a transistor which normally shunts a timing resistor is blocked, thereby increasing the time constant of the control integrator.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of fabricating a nano-tube that is suitably used for manufacturing a field-emission type cold cathode that is used as an electron source of a planar panel display, CRT, electron microscope, electron-beam exposure device, various electron-beam devices, etc. The invention also concerns a method of manufacturing the field-emission type cold cathode, as well as a method of manufacturing a display device.
2. Description of the Related Art
Attention has in recent years been drawn toward a carbon nano-tube as emitter material of a field-emission type cold cathode. Applications of the carbon nano-tube have been expected to occur and research and developments thereof have also been vigorously performed.
The carbon nano-tube is a type obtained by rounding a graphen sheet having carbon atoms regularly arranged, a planar graphite hexagonal net, into a tube-like configuration. Depending upon the diameter of the tube and the chiral angle, the electronic structure is largely varied. Therefore, the co-efficient of electrical conduction has a value between a metal and a semiconductor.
Therefore, it is the that the carbon nano-tube exhibits characteristic in that an electrical conduction thereof being close to one-dimensional electrical conduction.
This carbon nano-tube is a minute material, the diameter of that is in the order of nano-meters, the length of that is from 0.5 μm to several millimeters, and an aspect ratio of that is very high. For this reason, electric field is easily concentrated at end tip portion of the carbon nano-tube and thereby it is expected that a high level of emitted-current density can be obtained.
Also, the carbon nano-tube has the feature of having a high level of chemical and physical stability. Therefore, it can be presumed that, during its operation, the carbon nano-tube would not be adversely affected by the adsorption of residual gases, ion impact or the like, in a vacuum, easily.
FIG. 7 is a sectional view illustrating an example of a conventional field-emission type cold cathode, wherein the carbon nano-tube is used as the field-emission type cold cathode. It is to be noted that this type of field-emission type cold cathode is disclosed in the Japanese Unexamined Patent Publication (KOKAI) No. 9-221309.
This field-emission type cold cathode has a substrate 24 including carbon therein, on which a carbon nano-tube 26 to be used as an emitter, is formed by radiating ions onto the substrate 24 . Further, gate electrodes 28 , 28 and an insulating layer 27 are formed so as to surround the carbon nano-tube 26 .
A grid 29 through which an electron beam is drawn out, is formed so as to oppose the carbon nano-tube 26 .
The carbon nano-tube 26 has a diameter of from 2 to 50 nm and has a length of from 0.01 to 5 μm.
In this field-emission type cold cathode, an emission current of 10 mÅ is caused to occur with a voltage of 500V.
In this field-emission type cold cathode, the insulating layer 27 and the gate electrode 28 are formed so as to surround the carbon nano-tube 26 . Therefore, the amount of electrons that are emitted from the emitter can be controlled by an electric field that is formed applied between the gate and the emitter. Here, the electric field between the gate and the emitter is approximately equal to a value obtained by dividing the voltage applied to the gate by the thickness of the insulating layer 27 .
Note that, in case the thickness of the insulating layer 27 is large, it is necessary to apply a high level of gate voltage. However, in case the thickness of the insulating layer 27 is small, the same emission current can be obtained with a small gate voltage.
On the other hand, the electrons that have been emitted from the emitter each have a kinetic energy acting into a direction perpendicular to the electron emitting direction, depending upon the gate voltage. Therefore, the direction of the emission path of the emitted electrons are spread out.
In case of the gate voltage being low, it is possible to obtain an electron beam relatively highly bundled or having high level of coherency.
However, as the gate voltage becomes high, the degree of divergence of the electrons in the beam increases.
For example, in a planar display device in that a plurality of pixels are independently controlled, the divergence of the emitted electrons mean that the electrons directed toward one pixel, impinge upon an adjacent pixel. Thereby, the inconvenience in that an image becomes blur, or the contrast thereof is degraded or the like, will be caused to occur.
Accordingly, a decrease in the thickness of the insulating layer 27 is an indispensable factor for realizing a decrease in the drive voltage, a reduction in the size and cost of the drive circuit, a suppression in the spread of the electron beam or the like,
FIGS. 8 ( a ) and 8 ( b ) illustrate an example of a conventional planar display device, FIG. 8 ( a ) being a perspective view and FIG. 8 ( b ) being a sectional view. This planar display device is disclosed in the Japanese Unexamined Patent Publication (KOKAI) No. 10-199398.
In this planar display device, on a glass substrate 34 , rectangular cathodes 35 made of graphite and having a thickness of 1 μm and an insulating layers 37 made of a silicon oxide film and having a thickness of 7 μm, and width thereof being 20 μm, are stacked with each other.
On the cathode 35 , there is deposited using an arc discharge technique, a laser ablation technique or the like, a carbon nano-tube 36 having a rectangular configuration and having a thickness of several μm and that becomes an electron emission layer arranged in a line.
On the rectangular carbon nano-tube 36 , there are provided grid electrodes 38 , through which the electrons are drawn out, in such a way as to cross the carbon nano-tube 36 .
The carbon nano-tube 36 has a diameter of from 10 to 40 nm and a length of from 0.5 to several μm.
In this planar display device, applying a positive voltage to the grid electrode 38 and applying a negative voltage to the cathode 35 cause electrons 39 to be emitted in the arrow-indicated direction as shown in FIG. 8 ( b ).
FIG. 9 is a sectional view illustrating an electron-source array that is another example of the conventional field-emission type cold cathode, and that is disclosed in the Japanese Unexamined Patent Publication (KOKAI) No. 10-12124.
This electron-source array is the one wherein a carbon nano-tube 46 is grown in each of the fine holes 42 of an aluminum film 45 .
This electron-source array is manufactured as follows. First, the aluminum film 45 is deposited on a glass substrate 41 . This aluminum film 45 is etched to thereby form an element isolation region 44 within the aluminum film 45 . The remaining aluminum film 45 is used as an emitter region.
Subsequently, anodic-oxidation treatment is performed on the aluminum film 45 to thereby form the fine holes 42 . Thereafter, in each of the fine holes 42 there is buried a nickel particle 47 that becomes a nucleus of growth of the carbon nano-tube.
Thereafter, the nano-tube 46 is grown in an atmosphere containing therein methane gas and hydrogen gas. The reaction temperature at this time is ranging from 1000 to 1200° C.
With the use of the above-described procedure, it is possible to grow on the glass substrate 41 the carbon nano-tube 46 that has orientation in the vertical direction with respect to the substrate 41 . And, by attaching a grid electrode 48 onto an upper portion of the aluminum film 45 , it is possible to manufacture a field-emission type cold cathode.
Also, a phosphor 49 is disposed at a position that opposes a plurality of emitters, i.e., carbon nano-tubes 46 , each of which is isolated from each other by respective element isolation region 44 to thereby fabricate a planar display device.
Further, as an example of the method of fabricating a carbon nano-tube, there has also been proposed a method that includes a step of disconnecting part of the bond of each of the carbon atoms constituting the carbon nano-tube. The step thereby forms a non-bonded electron (dangling bond) (refer to the Japanese Unexamined Patent Publication (KOKAI) No. 7-172807).
In this method, a gold ion (Au + ) was used as an example, a crater structure is formed by one ion radiation. For example, selectively radiating a large number of ions onto the carbon nano-tube so as to cross over the carbon nano-tube, a plurality of crater structures are successively formed. And these crater structures are connected with one another, thereby the carbon nano-tube is disconnected.
Meanwhile, in the conventional field-emission type cold cathode illustrated in FIG. 7, in realizing an excellent electron-emission characteristic by making the insulating layer to have a thin thickness, the following problems arose.
(1) Flattening the surface of the emitter is difficult.
The carbon nano-tube obtained using the arc discharge technique or laser ablation technique that is a general carbon nano-tube manufacturing method, generally has a substantially constant value in diameter that is in an order of nanometers.
However, the length thereof shows various values raging from 0.5 μm to several mm. Also, because the carbon nano-tube has a high flexibility, it has the feature of one nano-tube being easily entangled with each other. Therefore, when the long carbon nano-tubes are entangled with each other, they get shaped like a large yarn junk. This causes a decrease in the flatness of the emitter.
Also, the coarse carbon nano-tube after the same has been produced contains therein graphite, amorphous carbon or the like, In case of especially a mono-layer carbon nano-tube, it contains a metal catalyst. The carbon nano-tube can be easily entangled with such impurities as well to thereby form a large mass.
It results in that local protrusions will occur on the surface of the emitter. These local protrusions cause to form a curvature in the insulating layer 57 and gate electrode 58 formed on the carbon nano-tube 56 on the substrate 54 and make the potential distribution non-uniform as illustrated in FIG. 10 .
Also, when the local protrusions are produced at the opening portion of the gate, the electric field is easily concentrated at this portion, reducing the uniformity of the electron-emission characteristic thereof deteriorated.
Furthermore, in the planar display device wherein a plurality of emitters are two-dimensionally arrayed, those large protrusions make the characteristic of one of the emitter portions, i.e., the pixels, different from those of other emitter positions (the pixels).
This causes unevenness in the image.
(2) The gate electrode and the emitter are electrically conducted to each other via the carbon nano-tube.
In case the carbon nano-tube having a length larger than the thickness of the insulating layer exists on the surface of the emitter, that carbon nano-tube contacts with the gate electrode 58 . There is resultantly the case where the gate electrode 58 and the carbon nano-tube 56 serving as the emitter electrically conduct with each other.
This short-circuit between the carbon nano-tube 56 and the gate electrode 58 becomes a cause of the decrease in the amount of electrons emitted and a cause of the destruction of the elements. As in the case of the above-described problems under the item No. (1), that short-circuit of the gate electrode and the emitter becomes a factor that causes the electron-emission characteristic to become non-uniform. Especially in the planar display device, the short-circuit makes the image uneven in many positions and also makes the image unstable.
In this field-emission type cold cathode, the length of the carbon nano-tube 26 is ranging from 0.01 to 5 μm. However, for example, in case the thickness of the insulating layer 27 is 5 μm or less, as described above, there is a possibility that the gate electrode 28 and the emitter will be short-circuited by way of the carbon nano-tube 26 . Or there is also a possibility that a mass of carbon nano-tube, having a length L being large, will locally occur inside the gate opening.
Also, in the conventional planar display device as well that is illustrated in FIG. 8, in case in that a large number of carbon nano-tubes each having a length being larger than the thickness (7 μm) of the insulating layer 37 , are contained therein, the same problems arise.
Further, in each of these two conventional examples, the carbon nano-tube is grown directly on the substrate. Therefore, it is difficult to control the length of this carbon nano-tube. Accordingly, in these conventional examples, realizing a uniform electron emission characteristic is difficult, which means that a limitation is imposed upon making a thickness of the insulating layer, thin.
Also, in the conventional electron-source array illustrated in FIG. 9, it is certainly possible to grow the carbon nano-tube 46 with a high control-ability in the direction perpendicular to the surface of the glass substrate 41 . However, the growth temperature of the carbon nano-tube 46 is approximately 1000° C. and the relevant steps for forming same, are complex. Therefore, this technique is unsuitable for manufacturing a planar display or the like, wherein a plurality of emitters are formed on the glass substrate 41 .
Also, in the conventional fabricating method of carbon nano-tube, because use is made of a convergent ion source, there was the problem that a long time was needed to cut off the carbon nano-tube through the entire surface of the emitter. Also, in an ordinary ion implantation, in case radiation has been performed until the carbon nano-tube is cut off, ions cause damage even to the portion that is not to be cut off. Resultantly, there was the problem that the most part of the carbon nano-tube became unable to have its annular shape maintained as it was.
SUMMARY OF THE INVENTION
The present invention has been made under the above-described draw-backs and has an object to provide a method of fabricating a nano-tube that enables cutting off the nano-tube in a short length without deteriorating the same and that, when using this nano-tube as the emitter, provides an improved flatness of the surface thereof.
Another object of the invention is to provide a method of manufacturing a field-emission type cold cathode that can provide an improved flat-ability of the emitter surface and that can therefore cause an emission of a uniform, stable high-emission electric current.
Still another object of the invention is to provide a method of manufacturing a display device that includes the above-described fabrication method of nano-tube and/or manufacturing method of a field-emission type cold cathode.
To attain the above object, the present invention has provided the following nano-tube fabrication method, field-emission type cold cathode manufacture method, and display device manufacture method.
Namely, a fabrication method of a nano-tube according to the first aspect of the invention comprises the step of radiating ions onto the nano-tube, and oxidizing the nano-tube.
In this fabrication method of a nano-tube, with a very much simplified method, the nano-tube has been provided with a non-bonded hand, i.e., the dangling bond, therein and is oxidized. Thereby, the nano-tube becomes able to be easily severed at the non-bonded hand without deteriorating the nano-tube. As a result of this, the length of the nano-tube is shortened, and the mutual entangles between or among the nano-tubes are lessened. If using this nano-tube as the emitter, the surface of the emitter has an improved flatness.
A fabrication method of a nano-tube according to the second aspect of the invention is constructed in a form wherein, in the fabrication method of a nano-tube according to the first aspect of the invention, in the ion radiating step, after an element had been ionized, the resultant ions are accelerated by an electric field and thereby radiated onto the nano-tube.
A fabrication method of a nano-tube according to the third aspect of the invention is constructed in a form wherein, in the fabrication method of a nano-tube according to the first aspect of the invention, an element had been reduced into plasma condition and the ions that have been produced in the plasma condition creating process, are radiated onto the nano-tube.
A fabrication method of a nano-tube according to the fourth aspect of the invention comprises the step of heating the nano-tube at a temperature of from 300 to 800° C., and radiating ions onto the nano-tube thus-heated.
A fabrication method of a nano-tube according to the fifth aspect of the invention comprises the step of heating the nano-tube at a temperature of from 300 to 800° C., and radiating an atomic state of atoms and ions onto the nano-tube thus-heated, simultaneously.
A fabrication method of a nano-tube according to the sixth aspect of the invention comprises the step of heating the nano-tube at a temperature of from 300 to 800° C., and radiating ions onto the nano-tube thus-heated, and oxidizing the nano-tube.
A fabrication method of a nano-tube according to the seventh aspect of the invention comprises the step of placing the nano-tube on a glass substrate, heating the nano-tube at a temperature of from 300° C. to a temperature lower than a distortion point of the glass substrate, radiating ions onto the nano-tube thus-heated, and oxidizing the nano-tube.
A fabrication method of a nano-tube according to the eighth aspect of the invention comprises the step of heating the nano-tube at a temperature of from 300 to 800° C., radiating ions and an atomic state of atoms onto the nano-tube thus-heated, simultaneously, and oxidizing the nano-tube.
A fabrication method of a nano-tube according to the ninth aspect of the invention comprises the step of placing the nano-tube on a glass substrate, heating the nano-tube at a temperature of from 300° C. to a temperature lower than a distortion point of the glass substrate, radiating ions and an atomic state of hydrogen onto the nano-tube thus-heated simultaneously, and oxidizing the nano-tube.
A fabrication method of a nano-tube according to the tenth aspect of the invention comprises the step of radiating ions onto the nano-tube, heating the nano-tube at a temperature of from 300 to 800° C., and radiating ions onto the nano-tube thus-heated.
A fabrication method of a nano-tube according to the eleventh aspect of the invention comprises the step of radiating ions onto the nano-tube, heating the nano-tube at a temperature of from 300 to 800° C., and radiating ions and an atomic state of atoms onto the nano-tube thus-heated, simultaneously.
A fabrication method of a nano-tube according to the twelfth aspect of the invention is constructed in a form the nano-tube is a carbon nano-tube.
A manufacturing method of a field-emission type cold cathode, the manufacturing method comprising an emitter containing therein nano-tubes, an insulating layer and gate electrode provided so as to surround the emitter, and an anode electrode provided on the gate electrode to thereby cause an emission of electrons from the emitter by applying a voltage to the emitter, the method comprising the steps of, introducing a gas onto the emitter, applying a voltage to one of the gate electrode, the anode electrode, and a newly provided electrode to thereby cause an emission of the electrons, ionizing the gas, and radiating the ions onto the nano-tubes.
A manufacturing method of a field-emission type cold cathode, the manufacturing method comprising an emitter containing therein nano-tubes, an insulating layer and gate electrode provided so as to surround the emitter, and an anode electrode provided on the gate electrode to thereby cause an emission of electrons from the emitter by applying a voltage to the emitter, the method comprising the steps of, introducing a gas onto the emitter, applying a voltage to one of the gate electrode, the anode electrode, and a newly provided electrode to thereby cause an emission of the electrons, ionizing the gas, radiating the ions onto the nano-tubes, and oxidizing the nano-tubes.
In the method for producing the field-emission type cold cathode in the past, it is possible to form a flat emitter and, in addition, a great number of the severed portions are formed. Thereby, the portions from which electron are emitted is become large in number, and a high performance of the emission and an increase in number of the emission points within the emitter are realized. Resultantly, the uniformity is enhanced. Resultantly, it is possible to cause the generation of a uniform and stable high-emission current.
A manufacturing method of a display device, the display device being a flat-surface type, according to the fifteenth aspect of the invention, comprises the fabrication method of a nano-tube according to one of the first to twelfth aspects of the invention, and/or, the manufacturing method of a field-emission type cold cathode according to the thirteenth or fourteenth aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 ( a ) and 1 ( b ) are step views illustrating a method of fabricating a nano-tube according to a first embodiment of the present invention, FIG. 1 ( a ) being a typical view a state where nitrogen ions are being radiated onto the nano-tube, and FIG. 1 ( b ) being a typical view illustrating a state that prevails after oxidation is performed;
FIG. 2 is a sectional view illustrating the method of fabricating a nano-tube according to a second embodiment of the present invention;
FIG. 3 is a sectional view illustrating the method of fabricating a nano-tube according to a third embodiment of the present invention;
FIG. 4 is a view illustrating the relationship between the number of forward ends of the carbon nano-tubes at the time of radiation of hydrogen ions and the temperature of the specimens according to the third embodiment of the present invention;
FIG. 5 is a sectional view illustrating the method of fabricating a nano-tube according to a fourth embodiment of the present invention;
FIG. 6 is a view illustrating the relationship between the number of forward ends of the carbon nano-tubes at the time of radiation of argon ions and the temperature of the specimens according to the fourth embodiment of the present invention;
FIG. 7 is a sectional view illustrating an example of a conventional field-emission type cold cathode;
FIGS. 8 ( a ) and 8 ( b ) are views illustrating an example of a conventional display device, FIG. 8 ( a ) being a perspective view thereof and FIG. 8 ( b ) being a sectional view thereof;
FIG. 9 is a sectional view illustrating an electron source array that is an example of a conventional field-emission type cold cathode; and
FIG. 10 is a sectional view illustrating an example of the inconvenience of the conventional field-emission type cold cathode.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention related to a method of fabricating a nano-tube, a method of manufacturing a field-emission type cold cathode, and a method of manufacturing a display device will now be explained hereunder with reference to the drawings.
First Embodiment
FIG. 1 ( a ) and FIG. 1 ( b ) are view illustrating an example of the method of fabricating a nano-tube according to a first embodiment of the present invention, in which a carbon nano-tube is used as the nano-tube.
In this fabrication method, first, by making use of the arc discharge method, the carbon nano-tube has been produced.
Here, in a case of nickel (Ni) and yttrium (Y) being used, as catalyst, mono-layer carbon nano-tubes are produced in a state where they are connected together into a bundled condition, in parallel with each other.
Also, in a case of no catalyst being used, a multi-layer carbon nano-tube is produced.
Subsequently, the carbon nano-tubes that have been deposited within a reaction chamber as if they were pieces of soot are collected. The carbon nano-tubes thus collected are in a state where a plurality of long carbon nano-tubes are entangled with each other.
Subsequently, using a mass of the entangled carbon nano-tubes as a sample, nitrogen ions (N + ) have been radiated onto this sample.
FIG. 1 ( a ) is a schematic view illustrating a state of the carbon nano-tube 1 after the nitrogen ion (N + ) 2 has been radiated thereto.
By the ion, a part of the bond of the carbon atom constituting a multi-layer carbon nano-tube is broken to thereby form a non-bonded portion, thereby a non-bonded hand 3 , i.e., the dangling bond, is produced.
In this state, when the resulting carbon nano-tube is heated in, for example, an atmosphere of low-pressure oxygen or an air, oxidization starts to occur on the non-bonded hand 3 , such as the dangling bond.
Thereby, as illustrated in FIG. 1 ( b ), at the portion of this non-bonded hand 3 , the carbon nano-tube 1 is dis-connected. The non-bonded hand 3 of the carbon nano-tube 1 is chemically unstable and, compared with the bonded carbon, is likely to react with oxygen molecules, or the like.
It is to be noted that an ion and a radical must have a sufficient level of energy to form the non-bonded hand 3 in the carbon nano-tube 1 .
In this embodiment, using nitrogen ions (N + ) as the ions, ion implantation was performed with an acceleration voltage of 25 KV and at an ion concentration of 1×10 13 cm −3 .
The optimum acceleration voltage, the kind of ion, and the amount of ion to be implanted are depended upon the amount of the carbon nano-tube 1 to be used and the degree of filling density of the carbon nano-tubes 1 to be fabricated, as well as the kind of the carbon nano-tubes 1 (especially, depending upon whether they are multi-layer carbon nano-tubes or mono-layer nano-tubes).
Also, in case of multi-layer carbon nano-tubes, they are depended particularly upon the number of the layers. However, if the acceleration voltage is 50V or less, there is almost no effect.
On the other hand, if the acceleration voltage is 10 KV or more, the number of the ions passed through the carbon nano-tubes becomes large resulting in the efficiency thereof becoming bad.
Also, in place of ion implantation, argon (Ar) was treated by by plasma discharging so as to ionize the argon and it was radiated onto the carbon nano-tubes 1 . Here, the carbon nano-tubes 1 were introduced onto a parallel/flat-plate type ground electrode.
Argon (Ar) then was introduced under a pressure of from 1.33×10 −1 to 1.33×10 −5 Pa (1×10 −3 to 1×10 −7 Torr) while a bias voltage of 500V was applied to an opposite electrode to the parallel/flat-plate type ground electrode. Thereby, the ions were accelerated and radiated.
The optimum acceleration voltage, the kind of ion, and the amount of ion implanted are depended upon the amount of, and the degree of a filling density of the carbon nano-tubes 1 to be fabricated, as well as the kind of the carbon nano-tubes 1 (especially, whether they are multi-layer carbon nano-tubes or mono-layer nano-tubes).
Also, in case of multi-layer carbon nano-tubes, the dependency is particularly depended upon the number of the layers. However, in case of the acceleration voltage being 50V, almost no effect was seen in the formation of the non-bonded hand 3 , while in case of the acceleration voltage being 5 KV or more, abnormal discharge being locally occurred within the reactor.
In the carbon nano-tubes 1 having made through the above-described manufacturing process, the hands of the bond between the carbon atoms at the side surface of the tube were broken, thereby the non-bonded hand 3 , i.e., the dangling bond, was formed.
The sample that had been treated in the above-described way was introduced into an oxidizing reactor and was heated in an atmosphere of low-pressure oxygen for a 1 hour. In case of the mono-layer carbon nano-tubes, the sample was heated at 300° C. and, in case of the multi-layer carbon nano-tubes, was heated at 600° C. The thus-heat-treated carbon nano-tubes were observed using an electronic microscope. As a result, a large number of the carbon nano-tubes the bonds of that had been dissociated were observed.
On the other hand, the sample that had not been radiated with ions was heated in an atmosphere of low-pressure oxygen under the same conditions. The thus-heat-treated carbon nano-tubes were observed using an electronic microscope.
As a result, almost no sections of the severed carbon nano-tubes were observed.
Through making use of the fabrication method of this embodiment, after having formed the insulating film and gate electrode, it is possible to sever the carbon nano-tubes and increase the emission points.
Through adding the fabrication method of this embodiment to a step of activating the emitter, i.e., an aging step, it is possible to increase an electric-current emission and thereby to increase the uniformity.
In this embodiment wherein making use of the ion implantation technique, compared to the conventional example using a focusing ion source, the time length during which ion radiation is performed is 10 times or more as large.
Even taking the oxidizing step into the account, a plurality of samples can simultaneously be treated, thereby it is possible to increase the throughput.
In addition, the variation within the substrate and the variation between the substrates each are also controlled. Therefore, the uniformity within the plane and the degree of severance of the carbon nano-tubes for each radiation, i.e., the average of the lengths of the carbon nano-tubes and the dispersion thereof, each are almost the same between the samples. Resultantly, the productivity is remarkably enhanced.
In addition, because the carbon nano-tube 1 is oxidized from the non-bonded hand 3 , no non-bonded hand 3 exists at the side surface of the portion of the carbon nano-tube that has remained as is without being oxidized.
Therefore, the carbon nano-tubes do not have any portion in which such non-bonded hand 3 have been still remained unused, therein, and namely, the carbon nano-tubes have no deteriorated portion therein.
Accordingly, no carbon removed from the non-bonded hand 3 due to oxidation, or the like, during and after the fabrication process of the carbon nano-tube, is occurred and subsequent severance of the carbon nano-tubes would not also be occurred, accordingly.
This means that the fall-off of the carbon-nano-tube from the emitter, is difficult to occur and thus the electric discharge and short-circuit resulting from the carbon nano-tube that has thus fallen off, and the breakage of the device resulting therefrom are difficult to occur.
In case of the conventional method, the carbon nano-tubes that have been entangled with each other in the above-described way, will become a mass whose size is from 10 to 100 μm or so. Therefore, in case of forming an emitter containing the carbon nano-tubes therein by using a coating method, especially in case of utilizing a flat-plate like emitter whose thickness is less than 100 μm, concaved portions and convexed portions, a difference in height thereof existing therebetween ranging from 10 to 100 μm, are produced in a way in that one of them being formed at a portion in which the carbon nano-tube exists and another one being formed at a portion in which no carbon nano-tube exists.
Resultantly, emission of the electrons concentratedly takes place especially from the areas where the convexities exist. Therefore, within the emitter, non-uniformity of the emission occurs.
On the other hand, in the fabrication method of this embodiment, the above-micronize carbon nano-tubes are coated after having been mixed into the mother material of the emitter, such as glass paste.
In this case, because of the micronization of the carbon nano-tubes, these tubes are free from the entanglement with one another and become easy to mix with the mother material.
Resultantly, in case having formed such carbon nano-tubes as the emitter, these tubes become uniformly mixed with the mother material, thereby the emitter becomes flat.
For the carbon nano-tubes that have been formed in this way, the controlling the time length of radiation of the ions and the time length of heating in an atmosphere of oxygen to the carbon nano-tubes, and the controlling the length of the tubes through centrifugation, or the like can be enabled.
It thereby becomes possible to regularly arrange the length thereof according to the thickness of the insulating film defining the distance between the emitter and the gate electrode.
Thereby, the problem that the gate electrode and the emitter are electrically conducted to each other, can be resolved.
In addition, during or after the coating of the emitter material containing the carbon nano-tubes on the substrate, the resulting substrate is heated at a temperature equal to or lower than the distortion point of the substrate, thereby the emitter is formed.
Therefore, the problems that the temperature of the substrate becomes high, the process steps become complex, or the like, can be resolved.
By using the carbon nano-tubes obtained according to the fabrication method of this embodiment is used as the emitter and disposing the anode electrode or the anode electrode and gate electrode, construction is made of a diode structure or triode structure.
And, with the emitter potential being used as a reference, a positive potential is applied to the anode electrode or gate electrode. In this case, a problem as would be occurred in a conventional method, in that the non-uniformity of electric-field distribution that the electric field becomes concentrated onto the convexity portions of the emitter having the concaved portions and convexities therein and resultantly the electric field at the concavity portions becomes weak, can be resolved.
Resultantly, the non-uniformity of the electron emission characteristic can be avoided.
Second Embodiment
FIG. 2 is a sectional view illustrating the fabrication method of a nano-tube according to a second embodiment of the present invention. This second embodiment illustrates an example wherein ions are radiated to the insulating film and gate electrode after when they are formed in the emitter.
In this fabrication method, first, an emitter electrode 5 consisting of metal is formed on a glass substrate 4 . On this emitter electrode 5 there is formed an emitter 6 containing therein the carbon nano-tubes.
And, on this emitter 6 , there are formed a gate-insulating film 7 having a thickness of 10 μm and a gate electrode 8 in this order.
Further, at a position approximately 1 mm away from the emitter 6 , there is disposed an anode electrode 9 opposing to the emitter 6 .
In this state, argon (Ar) gas is introduced under a pressure of 1.33×10 −1 to 1.33×10 −5 Pa (1×10 −3 to 1×10 −7 Torr).
Subsequently, the voltage of 50V is applied to the gate electrode 8 , and the voltage of 5 KV is applied to the anode electrode 9 , to thereby cause an emission of electrons from the emitter 6 containing therein the carbon nano-tubes.
In this state, when the electron (e − ) 10 emitted from the carbon nano-tube, impinges on argon (Ar) gas molecule, the argon gas becomes a positive argon ion (Ar + ) 11 .
Therefore, the argon gas is accelerated toward the gate electrode 8 and the emitter 6 containing therein the carbon nano-tubes to thereby impinge on the gate electrode 8 and emitter 6 containing therein the carbon nano-tubes.
At this time, the carbon bonds constituting the carbon nano-tube, are broken, thereby the non-bonded hand, i.e., the dangling bonds, are formed.
Subsequently, in place of the argon (Ar) gas, oxygen gas (O2) or air is introduced.
In a case of the sample being a mono-layer carbon nano-tube, heating is performed at 300° C., and in a case of the sample being a multi-layer carbon nano-tube, heating is performed at 600° C.
At this temperature, the sample is maintained for a 1 hour. After this heat treatment, the carbon nano-tube was observed using an electronic microscope.
As a result, the severed carbon nano-tube was observed in large number.
On the other hand, the sample to which no ion was radiated, was heated in an atmosphere of oxygen under the same conditions, and the resulting sample was observed using an electronic microscope.
As the result, the section of the severed carbon nano-tube was almost not observed at all.
It is to be noted that in this carbon nano-tube, the reaction of the carbon nano-tube with the oxygen gas is selectively caused from the non-bonded hand due to the oxygen, it was observed that the carbon nano-tube was partially severed.
Third Embodiment
FIG. 3 is a sectional view illustrating the fabrication method of a nano-tube according to a third embodiment of the present invention. This third embodiment is a method in that hydrogen gas (H 2 ) is ionized into ions (H + ) and it is radiated onto the carbon nano-tube to thereby form a non-bonded hand, and after that the carbon nano-tube is thereby severed.
In this fabrication method, using the same method as that in the first embodiment, there is prepared a sample having a glass substrate 14 and an emitter 16 containing therein the carbon nano-tubes and formed on the glass substrate 14 .
This sample was introduced into a vacuum chamber, and the glass substrate 14 was maintained at a fixed temperature between 25° C. and 800° C.
And, in this state, hydrogen ions (H + ) 12 were radiated with an acceleration voltage of 1 KV and an ions number of 1×10 14 cm −2 .
FIG. 4 is a view illustrating the relationship between the number of tip ends of the severed carbon nano-tubes having been observed using an electronic microscope and the temperature (° C.) of the sample.
According to this FIG. 4, the number of the tip ends of the carbon nano-tubes has a maximum value when the temperature of the sample is approximately 500° C.
Also, it is clear that compared to the number of the tip ends portion of such severed carbon nano-tubes at room temperatures, the efficiency of severance thereof at a temperature of from 300° C. to 700° C., is relatively high.
Fourth Embodiment
FIG. 5 is a sectional view illustrating the fabrication method of a nano-tube according to a fourth embodiment of the present invention.
In this fourth embodiment, illustration is made of an example wherein argon ions (Ar + ) and hydrogen ions (H + ) are simultaneously radiated to the carbon nano-tube.
In this fabrication method, using the same method as in the first embodiment, there is prepared a sample wherein an emitter 16 containing therein the carbon nano-tubes is formed on the glass substrate 14 .
This sample was introduced into a vacuum chamber. And, while maintaining the substrate 14 at a fixed temperature of from 25 to 800° C., argon ions (Ar + ) 11 was radiated with an acceleration voltage of 1 KV and an ions number of 1×10 12 cm −2 .
At the same time, a filament 17 was heated at approximately 2000° C.
Then, hydrogen gas (H 2 ) 13 is radiated to the filament 17 to thereby form an atomic state of hydrogen (H + ) 15 , which thereafter was radiated onto the carbon nano-tubes of the emitter 16 .
FIG. 6 is a view illustrating the relationship between the number of tip ends of the severed carbon nano-tubes having been observed with using an electronic microscope and the temperature (° C.) of the sample.
According to the illustration of FIG. 6, the number of the tip ends of the carbon nano-tubes has a maximum value when the temperature of the sample was approximately 500° C.
Also, compared to the number of the severance of the carbon nano-tubes at room temperatures, the efficiency of severance of the carbon nano-tubes at a sample temperature of from 300° C. to 700° C., is seemed to be extremely high.
Note that, in a case in which the above-mentioned treatment had been applied to a sample in that the carbon nano-tubes were arranged on a glass substrate 14 , it is preferable to treat the sample at a temperature equal to or lower than the distortion point of the glass.
In this embodiment, the severance of the carbon nano-tube is promoted.
The reason for this is, in addition to the effect of physical sputter made by hydrogen ions or argon ions, a generation of a chemical reaction through that a bonded substance of hydrogen radical and carbon radical such as methane (CH4) or the like, is produced due to a reaction being made between hydrogen and carbon, to thereby disconnection of carbon from the carbon nano-tube is promoted.
Apart from the method as mentioned above in this embodiment, there can exist separate methods in that the carbon nano-tubes can be broken efficiently without giving any damages thereon by utilizing a process comprising a combination of a step of chemical reaction between hydrogen and carbon constituting the carbon nano-tube and a step of oxidation and/or a process comprising a combination of a step of physically forming the non-bonded hand and a step of chemical reaction between hydrogen and carbon.
Note that when the process of comprising a combination of a step of chemical reaction between hydrogen and carbon constituting the carbon nano-tube and a step of oxidation was used, especially in the chemical reaction step, this reaction can be limited to the reaction with the carbon existing in the layer of the carbon nano-tube arranged on a surface of or in the vicinity of the surface of the carbon nano-tube.
Therefore, in this embodiment, the non-bonded hands, i.e., the dangling bonds, can be limited to be formed only in the layer of the carbon nano-tube which is arranged on a surface of or in the vicinity of the surface of the carbon nano-tube.
Accordingly, in the oxidizing process successively executed after the above-mentioned process, such layer arranged on a surface of or in the vicinity of the surface of the carbon nano-tube, is selectively removed therefrom or is more quickly removed comparing with the layer existing inside of the carbon nano-tubes.
For these reasons, since in the multi-layer carbon nano-tubes or the bundled mono-layer carbon nano-tubes, the layer arranged on a surface of the carbon nano-tubes, can easily be removed, selectively, it is possible to form the carbon nano-tubes having a diameter smaller than that of the coarsely produced carbon nano-tubes, or having a tapered portion therein.
On the other hand, when the process of comprising a combination of a step of physically forming the non-bonded hand and a step of chemical reaction between hydrogen and carbon, was used, especially in a case in that the non-bonded hands had been formed with accelerated ions, in the multi-layer carbon nano-tubes or the bundled mono-layer carbon nano-tubes, the non-bonded hands can be formed not only in the layer arranged on a surface of the carbon nano-tubes but also in the layer formed inside of the carbon nano-tubes.
Accordingly, it is possible to form the tip ends of the carbon nano-tube having a sharp-edged sectional configuration thereof or to form multi-layer carbon nano-tubes or bundled mono-carbon nano-tubes each having short length, respectively.
As described above, although the explanations have been given to each of the respective embodiments of the present invention with reference to the drawings, specific embodiments of the present invention are not limited to the above-described embodiments and the various kinds of variation in in design, or the like, to be used without departing from the subject matter of the invention.
For example, as the method of oxidizing, although the method of heating in an atmosphere of oxygen or air has been used, it is possible to selectively oxidize the carbon element in the non-bonded hand even with making use of an oxidizing method in which a gas molecule containing therein oxygen or oxidizing atoms is reduced into plasma condition and the oxygen ions and the plasma thus created are radiated such non-bonded hands or with making use of an oxidizing method in which an oxidizing water solution such as hydrochloric acid, sulfuric acid, or nitric acid is used.
As has been explained above, according to the invention, the nano-tubes including the carbon nano-tubes that has been formed using an arc discharge technique, or the like, each having a long length ranging from 1 μm to several mm long, can be severed so that each carbon nano-tubes can have the respective length being shorter than a distance formed between an emitter and a gate.
In addition, it can also be possible to form the short carbon nano-tubes without having any unnecessary damages or unnecessary deteriorated portion such as the non-bonded hands, such as the dangling bonds, on a side surface of the carbon nano-tubes.
Accordingly, during and after the manufacturing process of nano-tubes, the nano-tubes have the difficulty of being severed, especially the carbon nano-tubes are difficult to be removed off from an emitter portion, and thus this face can greatly contribute to generate advantages in that unnecessary discharge due to the carbon nano-tubes thus removed off therefrom and the destruction of the device due to such discharge are hardly occurred.
Further, in the emitter formed by such nano-tubes, such mutual entanglements among the carbon nano-tubes which had been typically observed in the conventional method, become seldomly to occur and thus even in a case in that the nano-tubes are mixed together with a binder, the emitter having a flat portion with uniform thickness or uniform surface can be formed.
In addition, compared with the prior art, in the present invention, much more number of the severed portions of the nano-tubes can be formed on the surface of the emitter. And since thus-severed portions of the nano-tubes can serve as the emission points, a lot of electrons can be uniformly emitted within the emitter or between the emitters.
Therefore, the field-emission type cold cathode with a low voltage and a high efficiency, can be formed
Further, in the planar display device using this field-emission type cold cathode, a uniform level of emission can be obtained, thereby low-voltage driving becomes possible.
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A method of fabricating a nano-tube that enables shortly cutting off the nano-tube without deteriorating the same and that when the nano-tube is used as the emitter can provide an improved flat-ability of the surface of the emitter, a method of manufacturing a field-emission type cold cathode that can provide an improved flat-ability of the surface of the emitter and that resultantly can cause an emission of a uniform, stable high-emission electric current, and a method of manufacturing a display device that includes a method of fabricating a nano-tube and/or a method of manufacturing a field-emission type cold cathode. The method of fabricating a nano-tube according to the present invention includes the step of radiating ions into a nano-tube and the step of oxidizing the nano-tube.
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REFERENCE TO RELATED APPLICATIONS
Reference is also made to the following and commonly assigned U.S. patent application entitled BROADBAND INTEGRATED TELEVISION TUNER, filed Aug. 1, 1997, Ser. No. 08/904,908 U.S. Pat. No. 6,177,964.
TECHNICAL FIELD
This invention relates to tuner designs and more particularly to a tuner system which allows for minimum power consumption.
BACKGROUND
Tuners do the selecting of desired signals from the total band of regard. For example, a television tuner may tune from channel 2 through channel 100, selecting a desired channel 8. In doing so, tuners must work in a variable signal environment, and thus are designed for satisfactory performance in the worse case environment.
It is well known in the art that the power consumption and dissipation for a tuner is very dependent on the tuner's linearity requirements, which are driven by characteristics of the incoming signal environment. It is also well known that a dense signal environment with large variation in individual signal strength requires a very linear receiver to avoid distorting the desired received signal. Conversely, environments with few signals with constant individual signal strengths require less linearity to avoid distortion.
Signals, depending on their use, have a maximum distortion level, above which there is definite performance degradation. Thus, tuners must be designed to produce no more than the maximum exceptable distortion when confronted with the worse case environment. When the severity of the environment is less than anticipated, the tuner is “over designed” requiring more power than if it was designed for the more benign-environment. Turners are designed with a simple power level and this power level is dependant upon turner design which, in turn, causes turner to be designed using maximum power levels.
Consequently, it is desirable to provide a tuner that requires only the power necessary to achieve exceptable distortion levels in a worse case and benign environments.
SUMMARY OF THE INVENTION
These and other objects, features and technical advantages are achieved by a system and method in which the tuner system is environmentally adaptive, only requiring maximum power in the worse case environment. In the more typical, more benign environment, the consumed power is just enough to provide the required system performance.
The tuner system consists of four main blocks, Environmental Assessment (EA), Assessment to Power Required (APR) converter, Power Control (PC), and the basic tuner. The EA determines the severity of the signal environment and passes that information to the APR converter. The APR converts the environmental data to the needed power required to meet overall system requirements and allocate the power requirements across the tuner where power control is available. The PC performs the required power control through switches and/or continuously variable controls. The tuner receives the desired signals, filters out the undesired signals, and in so doing, provides the required system performance, using only the necessary power level as set by the system depending upon the received signals.
Environmental Assessment can be performed in using a variety of different techniques, two of which are: 1) use of an inband detector and a control processor to sweep the frequencies of regard, and 2) use of a signal amplitude detector in the front-end of the tuner with inband signal level monitoring.
Method 1) is the most accurate of the two methods but requires the processor, during an inactive time, to sweep all available channels and to save the signal levels and number of “active” channels. An example of an inactive time is during the setup period when all channels are usually monitored to assess quality of the signal. This should be adequate for cable TV signals. Terrestrial broadcast may require monitoring during channel selection for a mobile-environment, since signal strengths may vary with time. The inband or “current channel” signal level can be obtained from the swept data or through the tuner's Received Signal Strength Indicator (RSSI).
Method 2) employs a signal level detector in the front end of the tuner to monitor the total signal power, utilizing a Total Signal Power Indicator (TSPI). This requires the processor to only monitor the result of this measurement and the output of the RSSI. This method takes very little processor and dedicated tuner time, but is somewhat less accurate than Method 1. The most accurate approach would utilize both methods, Method 1 primarily for cable and Method 2 for terrestrial broadcast.
Assessment to Power Required (APR) converter is a process that utilizes the acquired knowledge of the environment to determine the correct amount of power reduction. The input signal type is known in most TV sets through selection during setup or automatically determined by the processor by measuring certain channel frequencies. The signal power levels are found through the methods described above.
Accordingly, it is a technical feature of my invention that a turner system adjusts to a power level dependent upon detected signal types.
It is a technical feature on my invention that a tuner system scans the input signals to determine the power level that will be adequate for proper functioning of the tuner.
A further technical advantage of my invention is the design of a tuner which minimizes power consumption under adaptive control.
DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram of the Environmentally Adaptive Tuner System.
FIG. 2 is a schematic of a tuner that provides an Intermediate Frequency (IF) output.
FIG. 3 is an example of a power control mixer.
FIG. 4 is an example of a DC power control amplifier.
FIG. 5 is a schematic of a tuner that provides composite Video and Audio outputs.
FIG. 6 is a schematic of amplitude detectors and analog to digital conversion.
FIG. 7A is a plot of the input third order intercept point IIP 3 as a function of the measured signal level and the number of signals found at that signal level for NTSC Terrestrial.
FIG. 7B is equivalent to FIG. 7A for NTSC cable.
FIG. 8 is a plot of the required IIP 3 to maintain a 1% cross modulation as a function of the signal level of one undesired signal.
FIG. 9 is equivalent to 7 B except a Receive Signal Strength Indicator (RSSI) which measures the inband signal strength which determines the input signal level.
FIG. 10 is an example of the current required for a tuner component verses the required IIP 3 for that component; and
FIG. 11 is a flow diagram for the environmentally adaptive tuner system.
DETAILED DESCRIPTION
FIG. 1 is the top level diagram of the Environmentally Adaptive Tuner System (EATS) 10 wherein:
Tuner 11 is a tuner of current art adaptable to provide signals to Environmental Assessment 60 and to accept signals from Power Control 14 . Examples of such tuners were shown in FIGS. 2 and 5 .
Environmental Assessment (EA) 60 assesses the incoming signals and provides; depending on method, signal count, power levels, and signal types to Assessment of Power Required, block 13 . The EA function is further described in FIG. 6 .
Assessment of Power Required 13 (APR) uses algorithms to determine how much Direct Current (DC) power is required for each of the power control blocks in Tuner 11 . This result is signaled to the Power Control 14 function. APR algorithms are explained in the Detailed Description section.
Power Control 14 provides the circuitry required to vary (control) the DC power to each of the tuner's “power control blocks” to utilize only the power necessary to provide the required performance level.
FIG. 2 is a schematic of a tuner that provides an Intermediate Frequency (IF) output, indicating the interfaces that include the outputs to Environmental Assessment (EA) 60 and the inputs from Power control (PC) 14 . TSPI (Total Signal Power Indicator) and RSSI (Receive Signal Power Indicator) go to EA 60 . PC 14 provides DC power control to amplifiers 40 and 40 ′ and mixers 30 and 30 ′.
FIG. 3 is an example of how DC power control of mixer 30 can be accomplished. In this case mixer 30 is made up of 4 mixers wired in parallel, with separate switches to enable/disable power supply current flow to each of the mixers 301 through 304 . Power Control switches 3 SW 1 through 3 SW 4 just enough of the mixers 301 through 304 to provide only the required performance determined by the APR function 13 .
FIG. 4 is an example of how DC power of amplifier 40 can be accomplished. In this case amplifier 40 has 3 different resisters that can be independently selected to select 7 different DC power consumption states. The resister values have a binary relationship so that the current that goes through the amplifier varies from the minimum with just 4RTC selected by closing only switch 4 SW 3 to a minimum with all switches ( 4 SW 1 , 4 SW 2 , and 4 SW 3 closed).
FIG. 5 is a schematic of a tuner that provides composite Video and Audio outputs, indicating the interfaces that include the outputs to the Environmental Assessment (EA) function 60 and the inputs from the Power Control (PC) function 14 . The TSPI (Total Signal Power Indicator) and the RSSI (Receive Signal Power Indicator) go to the EA function. The PC function provides DC power control to amplifiers 40 and 40 ′ and mixers 30 and 30 ′. A more defined description of this circuit can be found in patent application entitled BROADBAND INTEGRATED TELEVISION TUNER, filed Aug. 1, 1997, Ser. No. 08/904,908 incorporated herein by reference.
FIG. 6 is a schematic of amplitude detectors and analog to digital conversion utilized to provide signal power indication to the APR function 13 . 6 D 1 and 6 D 2 are diodes that rectify the signal, to provide current to capacitors 6 C 1 and 6 C 2 . The capacitors are chosen to bypass the carrier but not the envelope frequency, thus providing an amplitude that is proportional to the signal power presented to the diodes 6 D 1 and 6 D 2 .
FIG. 7A is a plot of the required input third order intercept point IIP 3 as a function of the measured signal level and the number of signals found at that signal level for NTSC terrestrial broadcast. This function is based on cross modulation performance which, in this case, maintain no worse than 1% cross modulation level.
FIG. 7B is equivalent to FIG. 7A but for NTSC cable. In this case the Composite Triple Beats (CTB) is to be no worse than −57 dBc (decibels below the carrier).
FIG. 8 is similar to FIG. 7A , but since terrestrial NTSC typically has one large signal that dominates the undesired signals arriving at the tuner, this FIGURE is a plot of the required IIP 3 to maintain a 1% cross modulation as a function of the signal level of one undesired signal.
FIG. 9 is equivalent to 7 b except a Receive Signal Strength Indicator (RSSI) which measures the inband signal strength determines the input signal level.
FIG. 10 is an example of the current required for a tuner component verses the required IIP 3 for that component. The power required for a component is directly related to the required current.
FIG. 11 is a flow diagram for EATS. The first function makes the power measurements using either of the two procedures, with an without Processor Controlled Sweep. This result used along with alternate factors are passed to the second function which calculates the required IIP 3 for the tuner. Alternate factors include such items as signal types, mix of signal types (how many of the different types), and distribution of the signal types. The signal types include: “Digital”; 8VSB, 64QAM, 256QAM and “Analog” NTSC, PAL. Distribution of signal include: “upper half of channels digital”, “intermixed analog and digital channels”. The tuner IIP 3 is passed to the next function which determines the IIP 3 required for each of the “power controllable” components. This result is then passed to the function which finds the current required for each of the “controllable” components. This result is then supplied to the power Control function which controls the power to each of the “controllable” components.
Turning now to FIG. 1 , as shown in block diagram of the tuner system and method 10 of my invention. Tuner 11 is shown with an RF input, outputs to the Environmental Assessment 60 , and inputs from the Power Control 14 . Further detail of tuner 11 is provided in FIG. 2 and FIG. 5 .
Both FIGS. 2 and 5 show the TSPI output from amplifier 40 ′ and RSSI output from filter 203 in FIG. 2 and an RSSI output from the AGC function 515 in FIG. 5 that is provided to Environmental Assessment 60 .
Environmental Assessment (EA) 60 utilize these signals to determine, depending on method, signal count, power levels, and signal types to the Assessment of Power Required 13 function. The EA function is further described in FIG. 6 . While two methods of Environmental Assessment will be described here, other combinations of measurement techniques could also be formed and utilized in the EA function 60 .
Method one performs a sweep across all channels received, analyzing one channel at a time (much like the “setup procedure” performed with prior art TV systems. The second method uses the Total Signal Power Indicator and does not utilize the channel sweep. The second method can provide continuous updates on the signal environment, but may be less accurate. Of course both methods may be used, the “Channel Sweep Method” initially then the “Static Method” to provide updates, mostly for mobile systems.
The EA function 60 when using the Channel Sweep Method utilizes the RSSI signal to determine the inband signal strength (the signal power for the selected channel). In this mode the control processor will accumulate the RSSI result along with signal type data which can come from the tuner, from the demodulation functions, or from “TV guide” data, for each channel during the channel sweep process.
The EA function 60 when using the Static Method utilizes the Total Signal Power Indicator TSPI to estimate the total power, across all channels, coming into the tuner. It also utilizes the RSSI signal to determine the power being received for the currently selected channel.
When utilizing the TSPI signal, the total power at the input of the tuner can be estimated by adjusting A to D converter 601 output ( FIG. 6 ) for the gain through 6 D 1 , 6 C 1 , A to D converter 601 and LNA 40 ′.
When utilizing the RSSI signal the total power at the input of the tuner can be estimated by adjusting the A to D converter 601 output ( FIG. 6 ) for the gain through 6 D 1 , 6 C 1 , the A to D converter, and LNA 40 ′, mixer 30 , first IF filter 502 , second mixer 103 , amplifiers 40 and 40 ′, video detector 511 , and ADC function 515 .
Assessment of Power Required 13 (APR) function uses algorithms to determine how much Direct Current (DC) power is required for each of the power control blocks in Tuner 11 . This result is signaled to Power Control 14 function.
Three algorithmic steps are utilized to determine the current required for each controllable component as illustrated in FIG. 11 , item 13 . First the tuner IIP 3 (third order input intercept), the second order input intercept may also be utilized for some channel selections, is calculated 1102 . Then the component IIP 3 requirements 1103 , here the IIP 2 may be also utilized, are found that will yield the required tuner IIP 3 . The component current required 1104 , which when multiplied by the voltage across the component is the power consumed by the part, is then found that will provide the needed component intercept point. The component current requirement is then passed to the power control function 1105 .
The tuner IIP 3 algorithms 1102 utilized are dependent on the Environmental Assessment method (Channel Sweep or Static Method) and signal transmission medium (terrestrial or cable) and the signal type (analog, i.e., NTSC or digital, i.e, 8VSB or 256 QAM). For signal type we will discuss analog NTSC, other signal types are readily adaptable to these algorithms.
The Channel Sweep Method is the most accurate but requires the processor, during an inactive time, to sweep all available channels and save the signal levels and number of “active” channels. An example of an inactive time, is during the setup period when all channels are usually monitored to assess quality of the signal. This should be very adequate for cable TV. Terrestrial broadcast may required monitoring during channel selection for a mobile environment, since signal strengths may vary with time. The inband or “current channel” signal level can be obtained from the swept data or through the tuners Received Signal Strength Indicator (RSSI).
For terrestrial broadcast the IIP 3 can be determined from the largest (strongest) signal received during the sweep utilizing equation 1.
Tuner IIP3=Max_Signal−Xmod/2 (Equ 1)
Where:
Max_Signal is the maximum signal strength received from the channel sweep, referred to the tuner input. Xmod is the maximum cross modulation distortion sideband level specified. For example 1% cross modulation has −46 dBc sidebands.
For cable and NTSC analog broadcast the algorithm utilizes the average signal power received for each of the channels and the number of channels received to calculate the tuner IIP 3 in dBmV, and is presented in equation 2. FIG. 7B is a plot of Tuner IIP_ 3 for NTSC cable as a function of the average signal level received (Avg_Signal) and the number of signal received (CabSigs).
Tuner IIP3=Avg_Signal+{−CTB+6+10*log[(3/8)*(CabSigs+1) 2 ]}/2 (Equ 2)
Where:
Avg_Signal is the average signal level received in dBmV, referred to the tuner input. CTB is the specified Composite Triple Beat level. CabSigs is the number of cable signals received.
The static method utilizes a signal level detector monitoring the RF input, such as following the VLNA 40 ′, and the inband Receive Signal Strength Indicator (RSSI) outputs inband signal strength. The tuner will also output the amount of gain control provided to the VLNA. If this is not available, the processor has the Take Over Point (TOP) for the VLNA and can calculate the amount of gain control provided to the VLNA.
For terrestrial, there are relatively few signals (compared to cable) so a good estimate for the required IIP 3 can assume a single signal to give equation (3) and is plotted in FIG. 8 .
Tuner
IIP3
=
Signal_ln
+
-
x
mod
2
(
Equ
3
)
Where (Signal_In) is the measured the signal level referred to the input of the tuner, for example in dB units
Signal_In=Measured_Level−VLNA_gain+VLNA_attenuation (Equ. 4)
For cable by measuring the total input power, as in terrestrial above, and knowing the inband power from the RSSI measurement, the number of channels received can be estimated. The RSSI provides the estimate for the cable signal strength. The number of channels, “Cabsigs” in cable equations below, is (in linear units):
With the input signal level equal to:
Input_Level=Measured_Level+VLNA_attenuation_VLNA_gain (Equ 5)
Where:
Measured_Level is the measured RMS voltage level following the VLNA 40 ′ in dBmV VLNA_attenuation is the attenuation level set in the VLNA 40 ′ in dB VLNA_gain is the VLNA 40 ′ gain in dB
Gives the number of channels of:
CabSigs = 10 ( Input_Level / 10 ) 10 ( RSSI / 10 ) ( Equ . 6 )
Where:
RSSI is the Received Signal Strength Indication in dBmV and referred to the tuner input.
The component IIP 3 requirements are then determined 1103 from the tuner IIP 3 . This can be a lookup table or a simple algorithm than returns the IIP 3 for each of the “IIP 3 adjustable” components. The IIP 3 of the components will generally change proportionally with the tuner IIP 3 , so that a 10 dB reduction in the tuner IIP 3 will cause a 10 dB reduction in the component IIP 3 .
The component current requirements 1104 are then found from the component IIP 3 requirements 1103 . FIG. 10 is an example plot of how component tuner requirements can vary as a function of component IIP 3 requirement. This function can also be a lookup table or a simple algorithm.
This result is then passed to the Power Control 1105 function which actually changes the current utilized by the components in the tuner. Examples of the Power Control function are given in FIG. 3 for a mixer component and in FIG. 4 for an amplifier function.
With RSSI expressed in dB being equal to:
RSSI Xcab :=Xcab+sig (Equ. 7)
IIP3cab
Xcab
,
Cabsigs
:=
RSSI
Xcab
+
-
CTB
+
6
+
10
·
log
[
(
3
8
)
(
CabSigs
+
1
)
2
]
2
(
Equ
.
8
)
One approach is to separately control functions in the tuner with each having a lookup table in the processor that provides the proper control vs. required IIP 3 . Note this could also be performed off IIP 2 , but the IIP 3 is typically the driver. The functions to control are, for example, VLNA, MIX 1 , MIX 2 , FGA, LO 1 , LO 2 .
IIP 3 requirements also vary with signal types. For example, in order of increasing IIP 3 requirements, 8VSB, 64QAM, 256QAM and NTSC. This information is known to processor block 1106 FIG. 11 , and can be utilized through an additional axis on the lookup tables. Note the lookup tables could be replaced with a closed form algorithm for each function. Also rather than controlling each function separately, a power down control word could be provided and each function would self control in accordance with control word.
Power Control (PC) function 1105 is incorporated into the tuner and provides a means to vary the power consumption for each variable power function. FIGS. 3 and 4 are examples of power control for a mixer and an amplifier, respectively.
Amplifier 40 ( FIG. 4 ) has three control switches ( 45 W 1 , 45 W 2 , and 45 W 3 ) to provide seven levels of power control. The setting with all 3 switches closed provides the best distortion performance at maximum current (power with constant supply voltage). The power can then be reduced by up to 85% in seven steps with the corresponding reduction in performance, which, depending on the signal input type and the selected power level should not be harmful to the operation of the circuit.
Mixer example 30 shown in FIG. 3 has four levels of performance and power consumption. This circuit performs the power/performance control by selecting (via 35 W 1 , 35 W 2 , 35 W 3 , 35 W 4 ) the number of mixer cores 301 – 304 to run in parallel. The more mixer cores there are, the more power is used and the higher the performance. With all 4 mixer cores turned on full performance is obtained, consuming the most power. The power can then be reduced by 0.25, 0.5, and 0.75 with a corresponding reduction in power, again by selecting the power level bases on signal type and requirements no degraduation of the tuner output is.
A single mixer core could also utilize the variable tail current method to vary power/performance in mixer structures such as a “Gilbert Cell”.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
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A circuit and method for adjusting the operating characteristics of a tuner in accordance with information derived from the signals being processed by the tuner. Depending upon signal type and/or signal strength, the power levels of certain components are adjusted and/or certain components are added to (or subtracted from) the tuner.
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BACKGROUND OF THE INVENTION
Radiator caps for automobiles are known which are equipped with spaced members for seating against upstream and downstream seats provided on the filler neck of the radiator, with the lower member normally biased so as to effect a sealing force against the downstream seat, to seal the radiator and to cause the radiator to function at a selected design pressure above atmospheric pressure. When pressure in the radiator exceeds the selected design pressure, the lower seal member unseats to permit escape of pressurized gas and liquid and to avoid damage to the system. However, since some pressure is retained in the radiator, and since sudden release of the design pressure could itself be dangerous, it has been known to provide such a cap with means that compel release of all radiator pressure above atmospheric pressure before the cap can be removed from the radiator filler neck. In one such construction the lower member is provided with a vent valve that is selectively openable to release excess pressure, and is automatically openable to relieve a vacuum in the radiator. In another such construction, selective release of excess pressure is achieved by lifting the entire lower valve.
It is also known to provide a coolant recovery system for automotive radiators wherein the cap therefor includes a lower seal disc that is normally spring biased against the lower seat of a radiator's filler neck, such that as the raditor's coolant expands it operates to lift the lower seal disc to permit expanded coolant liquid to flow from the radiator to a coolant recovery container, and to then siphon back to the radiator upon the radiator cooling. The cap for such a system does not have means for selectively and safely venting excess pressure from the radiator. Thus, in coolant recovery systems, removal of a radiator cap before pressure in the radiator has been safely reduced, has led to hand burns; the alternative being substantial time delay in waiting for the radiator's contents to cool to a safe temperature.
Heretofore, no cap for a coolant recovery system has been provided with a safety venting valve feature which precludes removal of the cap until after radiator pressure had been released, and which also provides utility in the coolant recovery system permitting expanded coolant to flow to a coolant recovery container and providing for siphonage of coolant through the safety venting valve of the cap from the recovery container to the radiator upon cooling of the radiator.
It is desirable that a radiator cap prevent loss of radiator coolant liquid. However, wherever there exists a movable part that is required to act freely and easily in the presence of pressurized liquid, there always exists the possibility of undesirable leakage of liquid through the channels defined between moving parts.
Thus, one object of this invention is to provide a radiator cap for a coolant recovery system that provides both a safety venting feature which precludes removal of said cap until radiator pressure has been first vented to the coolant recovery reservoir and which also provides utility in the coolant recovery system, permitting passage of expanded coolant therepast to a coolant recovery container and which provides for siphonage of coolant from the recovery container through a portion of said radiator cap back into the radiator without loss of coolant past the cap.
Another object of this invention is to provide a multiple purpose radiator cap with a selectively movable stem for actuating a vent valve in the cap and with means to permit ready action of the movable stem while limiting leakage of pressurized liquid, and atmospheric air when siphoning, therethrough.
Further objects and advantages will become apparent to one skilled in the art from the following description of a preferred embodiment of the invention.
SUMMARY OF THE INVENTION
The improved cap of the present invention is adapted for use with an automotive vehicle equipped with a coolant recovery system wherein temperature-expanded coolant moves under pressure from the radiator to a coolant-capturing reservoir and upon cooling the coolant is siphoned back from the reservoir to the radiator. The radiator has a filler neck which has thereon an upstream seat and an adjacent camming flange, and also a downstream seat past which temperature-expanded coolant will pass. The filler neck between said upstream and downstream seats, connects through a tube to a coolant-capturing reservoir.
The radiator cap includes: a cap head shaped to cooperate with a filler neck for manual twist-on connection to the filler neck; an upstream spring disc for cooperation with the filler neck's terminus to bias the cap head away from said terminus of the neck; an annular resilient seal, or gasket, positioned between the spring disc and filler neck's terminus to provide a seal against liquid and air leakage therepast; an elongated annular body secured at its upper end to the cap head and with an out-turned flange at its lower end, a downstream valve mounted to be axially movable relative to the elongated body; spring means biasing the downstream valve away from the cap head; the downstream valve including a vent valve member that is spring biased upstream; a vent pin arranged for reciprocation through the annular body and positioned to selectively depress the vent valve when moved downstream; a lever for selectively moving the vent pin; a frusto-conical spring between the annular body and vent pin biasing the vent pin downstream; constricted passageway sections between the vent pin and elongated body, separated by an axially elongated pocket in which the O-ring rolls, said constricted passageway sections serving to capture the O-ring in the pocket where the necessary seal is effected; and an O-ring seal upstream of said constricted passageway to prevent loss of liquid and air, or vapor, therethrough.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the radiator cap of the present invention, illustrating the cap operatively attached to a radiator and illustrating the cap's communication with a coolant-capturing reservoir, the same comprising a coolant recovery system for an automotive vehicle;
FIG. 2 is an enlarged axial cross-sectional view of the radiator cap shown operatively positioned on the upper-end of a radiator filler neck and taken substantially along line 2--2 of FIG. 1; and
FIG. 3 is a cross-sectional view taken substantially on line 3--3 of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and specifically to FIGS. 1 and 2, the improved radiator cap is shown at 10. Although cap 10 could be used merely as a vented cap for a radiator, it is shown in FIGS. 1 and 2 as one component of a coolant recovery system for an automotive vehicle. The coolant recovery system includes a radiator 12 having a filler neck 14 from which extends an overflow tube 15 which connects through hose 16 to a coolant-capturing reservoir 17. Also illustrated in FIG. 1 is an overflow tube 18 from reservoir 17, and a conduit 19 that leads from the radiator 12 to some other component of the automotive vehicle that may require circulation of coolant from the radiator 12.
The coolant recovery reservoir 17 is illustrated as a capped, hollow, generally rectangular tank, although the shape thereof is of no particular significance. The reservoir 17 receives temperature expanded coolant from the radiator 12 via overflow tube 16 that extends through reservoir cap 17a. The tube 16 includes an elongated siphon portion 16a shown in phantom in FIG. 1 extending from cap 17a to the bottom of the reservoir 17, to prevent introduction of air into the radiator 12 while cooled coolant is being siphoned from reservoir 17 back into radiator 12, as known in the art.
The filler neck, generally 14, includes an elongated tubular part 14a, and an annular, shaped, part 14b that is brazed or welded to tube 14a. The shaped part 14b defines an annular, flat, upstream terminus, or seat 20 that extends radially outwardly relative to tube 14a, and an annular downstream seat 22, below which extends a tubular stub 23. The adjacent side walls of parts 14a and 14b are pierced in a region spaced axially between seats 20 and 22, to receive the terminus of tube 15 which is brazed or welded at 24 to part 14a. The part 14b is formed to provide an annular, downturned, flange 26, outwardly of seat 20, with a lower terminal edge shaped to provide cams thereon, as known in the art, for cooperation with a twist-on cap.
The improved, vented radiator cap 10 of the present invention includes a cap head 28 for connection to the flange 26 of annularly shaped part 14b of the radiator filler neck 14, an upper valve disc means 30 for sealing against the upper seat 20 on filler neck part 14b, a selectively operable pressure vent means, generally 32, for opening a lower valve to vent pressurized steam and/or coolant to the coolant recovery container 17 prior to removal of the radiator cap 10, and automatically pressure-operable, release valve means 34, for permitting the escape of temperature expanded coolant and pressurized steam from the radiator 12.
The cap head 28 of the radiator cap 10 is of well-known construction and includes a plurality of ears, such as 36, for engagement with the cap camming flange 26 of the filler neck 14. When the cap 10 is placed atop the radiator 12 with the cap head 28 covering the opening in the filler neck 14 and the ears 36 engaging the camming flange 26, twist-on rotation of the cap 10 will operate to firmly seat said cap 10 on the filler neck part 14b.
The upper valve disc means 30 comprises an annular, upper spring disc 38 having a central aperture 40 therethrough, and an annular, coaxially positioned, resilient gasket 42, below disc 38 and having a central aperture 44 therethrough, and being of a size to sealingly engage seat 20 to form a seal therewith that provides a seal against leakage of temperature-expanded coolant, and air when siphoning, therepast. The diameter of the central aperture 44 through the resilient gasket 42 is shown greater than the diameter of the central aperture 40 through the spring disc 38. The upper valve disc means 30 is operatively associated with the cap head 28, so that when cap head 28 is secured to the camming flange 26 of the filler neck, the spring disc 38 is biased axially toward seat 20 to resiliently force gasket 42 into sealing relation with seat 20.
The selectively operable steam vent means 32 includes an axially elongated annular body 46 that is secured to the cap head 28, an elongated vent pin 78 that reciprocates through the axial bore of annular body 46, and lower vent valve means 34. A handle 90 is pivotally connected to vent pin 78.
The axially, elongated, annular body 46 has a stepped, through-bore shaped to define an upper, small diameter portion 45 and a lower, larger diameter portion 47. The upper end 48 of the annular body 46 is crimped as at 50 so as to secure said annular body 46 to a lip 52 of the cap head 28 and to the inner edge of the upper annular spring disc 38. The opposite, or lower end 49 of said annular body 46 is shaped to provide thereon an outwardly extending retainer flange 54. An elongated central portion 60 extends between the upper body end 48 and said retainer flange 54 on the annular body 46.
A coolant-control valve means 56 is provided by a generally annular, downwardly facing, bell-shaped member that is slidably positioned on the exterior, central portion 60 of the annular body 46 that is above the retainer 54. The coolant-control valve means 56 provides thereon an upper end 61 of a diameter less than the diameter of the enlarged retainer flange 54, so that body 56 cannot slide past the lower end 49 of the annular body 46. The central opening defined in said upper end 61 of valve means body 56 is hexagonally shaped, as best seen in FIG. 3, so as to establish flow spaces through which liquid flow, illustrated by arrows A in FIG. 3, will move when said body 56 is moved upwardly away from its normal seating position abutting retainer flange 54 of annular body 46. The flow spaces are defined between the circular exterior of central portion 60 of body 46 and the corners 51 of the hexagonally-shaped opening in valve body 56.
A compression coil spring 62 surrounds the annular body 46 in spaced relation thereto and is axially captured between spring disc 38 and a shoulder formed on valve body 56 so as to serve to normally bias the coolant-control valve means 56 in a downward direction, i.e., away from the cap head 28 and toward said retainer flange 54 which serves as an abutment for valve body 56. The inner diameter of the annular resilient gasket 42 clears the outer diameter of the coil spring means 62 so that gasket 42 is not engaged by coil spring 62.
The reciprocating vent pin 78 is elongated to extend coaxially through central bores 45 and 47 of the annular body 46, and to extend axially outwardly above cap head 28 and below the lower extent of body 46. The vent pin 78 is shaped to provide three axially extending portions. The lowermost end portion is of greatest diameter and provides a valve engaging head 80. The elongated upper end portion 81 is of smallest diameter and carries, adjacent its uppermost end, a pivot pin, or rivet, 81a, to which handle 90 connects. The intermediate portion 83 is of a diameter less than that of the valve engaging head 80 but greater than that of the upper end portion 81. The diameter of the valve engaging head 80 is substantially greater than the diameter of the lower bore 47 of the annular body 46. The diameter of the intermediate portion 83 of the vent pin 78 is only slightly less than the diameter of the surrounding bore 47 of the annular body 46 to aid in defining the elongated capturing pocket 84 for O-ring 86. The diameter of upper pin portion 81 is considerably less than the diameter of the bore 47 of the annular body 46 to form an enlarged, annular, axially elongated space, or pocket, 84 therebetween. The space 84 is of lesser axial length than the length of the downstream bore 47 of the annular body 46. The diameter of the elongated upper end 81 of the vent pin 78 is slightly less than the diameter of the surrounding upsteam bore 45 in annular body 46, to permit reciprocation of said vent pin 78 therein but again to provide a very limited dimension spacing therebetween. The axially spaced portions of the vent pin 78, lying closely adjacent to the respective bores 47 and 45 of the annular body 46, provide restricted annular passageways adjacent both ends of the elongated, relatively enlarged, space 84.
An O-ring 86 is carried on the upper, small diameter, end portion 81 of the vent pin 78, within the downstream bore 47 of the annular body 46, so as to be positioned in space 84 in fluid-tight, and essentially air tight, sealing relation with both the vent pin 78 and the lower bore 47 of body 46. The O-ring 86 effects a rolling seal in the space 84 as said vent pin 78 is reciprocated, thereby preventing leakage of liquid or gas between the vent pin 78 and the annular body 46. The restricted passageways above and below the space 84, defined between pin 78 and body 46, provide restrictions that reduce total pressure applied to O-ring 86, permitting the O-ring to provide good sealing in the space 84.
A lower spring 88 is positioned between the lower terminus of body 46 and the valve engaging head 80 of the vent pin 78 and operates to normally bias the vent pin 78 in a downward direction. The spring 88 is a frusto-conical, helical spring having at one end a maximum diameter, when compressed, that is no greater than the outer diameter of the retainer flange 54 of the annular body 46, with said spring 88 having, at its other end, a minimum inner diameter not less than the diameter of portion 83 of vent pin 78 and not greater than the diameter of the head of vent pin 78. Preferably the spring 88 lies substantially in a plane when fully compressed as seen in FIG. 2.
The handle 90 provides an elongated lever pivotably connected to one end 92 to the upper end 81 of vent pin 78. Handle 90 has a tang 96 which projects through an aperture in cap head 28 which, as a safety feature, interferes with movement of cap 10 until handle 90 has been raised, as is known in the art. The handle 90 adjacent said one end 92 is shaped to provide a cam portion 94 which normally abuts member 95 in an over-center position to maintain said vent pin 78 in an inoperative position, illustrated in FIG. 2, wherein the spring 88 is compressed and potentialized. The cam portion can be selectively moved out of its over-center position by raising handle 90 to a cap-release position, thereby permitting the potentialized spring 88 to move the vent pin 78 in a downward direction to engage and depress an actuating stem 64 of the vent valve means 34 to permit the release of pressurized steam and/or coolant in the radiator 12. After the radiator 12 has been vented of pressurized steam and/or coolant, it is safe for a person to remove cap 10.
The coolant-control valve means, or body, 56 is provided at its lower end with an out-turned flange 56a to which is connected a sheet metal disc part 74. The force of the coil spring 62 thereby operates to bias disc part 74 downwardly. A resilient disc 75 is positioned against the downwardly facing side of disc part 74 and is of a size to engage and sealingly seat against lower seat 22 on filler neck part 14b.
The vent valve means 34 includes the actuating stem 64, a frusto-conical spring 72, a ferrule 76 and an annular disc 66 positioned below resilient disc 75. The size of the parts is such that when the radiator cap 10 is twisted to its connected position on the radiator filler neck 14, the annular resilient disc 75 will be sealingly pressed against the lower seat 22 of the radiator filler neck part 14b.
The axially-extending, generally cylindrical, actuating stem 64 of the vent valve means 34 has its lower end crimped onto the annular valve disc 66 which normally is in sealing relation with resilient disc 75. The upper end of the actuating stem 64 is radially enlarged to form a stem head 68 against which a frusto-conical spring 72 abuts. As noted above, the actuating stem 64 will be moved downwardly against the bias of spring 72, when the handle 90 is pivoted, to permit the vent pin 78 to move downwardly to contact and depress said stem 64. The disc 66 is normally biased upwardly by spring 72, so that offset annular portion 67 of said disc 66 contacts and seals against the underside of resilient disc 75.
The disc part 74 is clamped to resilient disc 75 at their radial inner edges by ferrule 76, through which the actuating stem 64 extends. The diameter of the actuating stem 64 is substantially less than the inner diameter of the ferrule 76 to provide a flow path for gas and liquid therethrough.
The actuating stem 64 of the vent valve means 34 extends axially upwardly of resilient disc 75 and disc part 74 but terminates at a point spaced below the vent pin's flange 80, so as to be normally inaccessible when the radiator cap is used in its normal and intended manner.
THE OPERATION
With the radiator cap 10 of the present invention operatively positioned on the filler neck 14 of the radiator 12 of an automotive vehicle equipped with a coolant recovery reservoir 17, the upper annular resilient gasket 42 is pressure seated on the upper seat 20 of said radiator filler neck tube 14a. The upper seat 20 and the resilient gasket represent primary sealing elements which retain the coolant within the recovery system.
When the automotive vehicle is operated, the coolant in the radiator 12 becomes heated and the pressure builds up until it reaches a point where the force of the coolant, or gas against the underside of annular disc 75 forces the disc 75 off its seat 22 and permits the coolant from the radiator 12 to flow around disc 75 into the lateral overflow tube 15 in the radiator filler neck 14 and finally via overflow tube 15 into the coolant recovery reservoir 17.
When the engine cools, a partial vacuum is created in the radiator and communicated to filler neck 14. The vacuum opens the vent valve means 34 against the resistance of the stem-biasing coil spring 72 and the coolant is sucked from the coolant recovery reservoir 17, through the overflow tube 15, into the filler neck 14, through the hexagonally-shaped opening in the coolant-control valve means 56, past the open vent valve means 34 and into the radiator 12. The siphoned coolant path is depicted in FIG. 2 by the series of arrows marked B. When the pressures internally and externally of the radiator 12 are substantially equal, the vent valve means 34 returns to its normally closed position.
In order to accomplish the recovery of coolant from the coolant recovery reservoir 17, it is imperative that there be a minimum of leakage from the top of the filler neck 14, or the vacuum siphoning action could not occur. The positioning of the O-ring seal 86 in the enlarged, O-ring capturing space 84, and the spring bias of the spring 38 forcing the annular resilient gasket 42 against the upper seat 20 operate to normally restrict the ingestion of air which would otherwise operate to destroy the siphoning action.
At such times that servicing of the radiator 12 is necessary, the handle 90 of the vented radiator cap 10 is lifted, and the vent pin is pushed downwardly by the potentialized stem-biasing frusto-conical spring 88. The valve-engaging head 80 of the vent pin 78 moves downwardly to engage the stem head 68 and depress the actuating stem 64 of the vent valve means 34, thereby causing the vent valve means 34 to open. The pressurized coolant and/or steam is then discharged into the coolant recovery reservoir 17 by following the same path as described above for the siphoned coolant, and steam can then escape to atmosphere through overflow tube 18 until a safe pressure condition is achieved in radiator 12.
The serviceman is now able to twist off the radiator cap 10 from filler neck 14.
While one form of the invention has been described, it will be understood that the invention may be utilized in other forms and environments, so that the purpose of the appended claims is to cover all such forms of devices not disclosed but which embody the invention disclosed herein.
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A radiator cap is provided with safety venting character for use with a coolant recovery system. The cap is provided with lever means which compel safety venting of excess pressure in the radiator before the cap can be removed, the venting being effected automatically through a selectively movable valve that is moved to an open position by actuation of the lever means. The cap serves as part of a coolant recovery system, with the selectively movable valve also serving as the valve that automatically opens to permit siphoning of coolant back into the radiator during the cool-down portion of the coolant's heating and cooling cycle.
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BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for transforming thermal energy from a geothermal heat source consisting of a mixture of geothermal liquid and geothermal steam ("geofluid" ) into electric power. This invention further relates to utilizing the energy potential of both geothermal liquid and geothermal steam in one integrated system.
Geothermal heat sources can generally be divided into two groups. In the first group are "liquid-dominated" heat sources that produce mostly hot geothermal liquid (brine). In the second group are "steam-dominated" heat sources that produce mostly geothermal steam with some geothermal liquid.
Methods for converting the thermal energy released by geothermal heat sources into electric power present an important and growing area of energy generation. Geothermal power plants generally belong to one of two categories, namely, steam plants and binary plants.
In steam plants, the geothermal source is utilized directly to produce steam (e.g., by throttling and flashing geothermal liquid). That steam is then expanded in a turbine, producing power. In binary plants, heat extracted from the geothermal liquid is used to evaporate a working fluid that circulates within the power cycle. The working fluid is then expanded in a turbine, producing power.
Steam plants are generally used for steam-dominated geothermal heat sources, while binary plants are generally used for liquid-dominated geothermal heat sources. U.S. Pat. No. 4,982,568 describes a method and apparatus for transforming thermal energy from geothermal liquid into electrical power in a binary plant. This method increases efficiency by using a thermodynamic cycle with a multi-component working fluid and internal recuperation.
SUMMARY OF THE INVENTION
In a first aspect, the invention features a method of implementing a thermodynamic cycle that includes the steps of:
expanding a gaseous working stream, transforming its energy into usable form and producing a spent working stream;
heating a multicomponent oncoming liquid working stream by partially condensing the spent working stream; and
evaporating the heated working stream to form the gaseous working stream using heat produced by a combination of cooling geothermal liquid and condensing geothermal steam.
In preferred embodiments, the liquid working stream is superheated following evaporation using heat produced by cooling geothermal liquid to form the gaseous working stream. The multicomponent oncoming liquid working stream is preferably preheated by partially condensing the spent working stream, after which it is divided into first and second substreams. The first substream is then partially evaporated using heat produced by partially condensing the spent working stream, while the second substream is partially evaporated using heat produced by cooling geothermal liquid. The partially evaporated first and second substreams are then combined and evaporated to form the gaseous working stream using heat produced by a combination of cooling geothermal liquid and condensing geothermal steam. The difference between the boiling temperature of the second substream and the temperature of the geothermal liquid preferably is greater than the difference between the boiling temperature of the first substream and the temperature of the condensed spent working stream.
The geothermal steam is expanded, transforming its energy into usable form and producing a spent geothermal stream. The spent geothermal stream is then condensed to heat and partially evaporate the liquid working stream, after which it is combined with the geothermal liquid and used for further evaporation of the liquid working stream. Where the geothermal steam content of the geofluid is relatively high, it is preferable to perform multiple expansions of the geothermal steam. Thus, in one preferred embodiment, the spent geothermal stream produced by a first expansion of geothermal steam is divided into first and second geothermal substreams. The first geothermal substream is condensed to heat and partially evaporate the liquid working stream, and then combined with the geothermal liquid. The second geothermal substream is expanded, transforming its energy into usable form and producing a spent geothermal substream, which is then condensed to heat and partially evaporate the liquid working stream. The spent geothermal substream is then combined with the geothermal liquid.
In a second aspect, the invention features apparatus for implementing a thermodynamic cycle that includes:
means for expanding a gaseous working stream, transferring its energy into usable form and producing a spent stream;
a heat exchanger for partially condensing the spent stream and for transferring heat from the spent stream to an oncoming multicomponent liquid working stream;
a separator for separating geofluid into geothermal liquid and geothermal steam; and
a multiplicity of heat exchangers for cooling geothermal liquid and condensing geothermal steam, and for transferring heat from the geothermal liquid and geothermal steam to evaporate the liquid working stream and form the gaseous working stream.
In preferred embodiments, the apparatus includes a heat exchanger for cooling geothermal liquid and transferring heat from the geothermal liquid to superheat the liquid working stream and form the gaseous working stream. The apparatus also preferably includes a stream separator for dividing the heated liquid working stream into first and second substreams; a heat exchanger for partially condensing the spent working stream and transferring heat from the spent working stream to partially evaporate the first substream; a heat exchanger for cooling the geothermal liquid and transferring heat from the cooled geothermal liquid to partially evaporate the second substream; and a stream mixer for combining the partially evaporated first and second substreams.
The apparatus further preferably includes means for expanding geothermal steam, transforming its energy into usable form and producing a spent geothermal stream; a heat exchanger for condensing the spent geothermal stream and transferring heat from the spent geothermal stream to partially evaporate the liquid working stream; and a stream mixer for combining the spent geothermal stream with the geothermal liquid. To accommodate geofluids with relatively high geothermal steam content, the apparatus further includes a stream separator for dividing the spent geothermal stream produced in the first expansion into first and second geothermal streams; a heat exchanger for condensing the first geothermal substream and transferring heat from the first geothermal substream to partially evaporate the liquid working stream; a stream mixer for combining the first geothermal substream with the geothermal liquid; means for expanding the second geothermal substream, transforming its energy into usable form and producing a spent geothermal substream; a heat exchanger for condensing the spent geothermal substream and transferring heat from the spent geothermal substream to partially evaporate the liquid working stream; and a stream mixer for combining the spent geothermal substream with the geothermal liquid.
The invention provides an integrated system that utilizes the energy potentials of both geothermal steam and geothermal liquid (brine). The system can handle practically all geothermal resources in almost any proportion between steam and liquid. Geofluids from different wells having different temperatures and different proportions of steam and liquid may be used as well. Higher outputs and efficiencies are achieved relative to systems in which geothermal liquid and geothermal steam are utilized separately. In addition, the efficiency and output are higher relative to steam power systems that are currently used for utilization of such geothermal resources.
Because the heat source for the thermodynamic cycle involves a combination of cooling geothermal liquid and condensing geothermal steam, only a one stage expansion of the working fluid is necessary (as opposed to two stages of expansion with intermediate reheat). Moreover, by splitting the liquid working fluid into two substreams, one of which is partially evaporated by heat transferred from cooling geothermal liquid and the other of which is partially evaporated by heat transferred from partially condensing spent working fluid, geofluid having a high degree of mineralization (which can be cooled only to relatively high temperatures) can be used as well.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of one embodiment of the method and apparatus of the present invention.
FIG. 2 is a schematic representation of a second embodiment of the method and apparatus of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The schematic shown in FIG. 1 shows an embodiment of preferred apparatus that may be used in the above-described cycle. Specifically, FIG. 1 shows a system 100 that includes a gravity separator 101, a preheater in the form of a heat exchanger 109, a superheater in the form of a heat exchanger 104, and a boiler in the form of heat exchangers 103, 106, 107, and 108. In addition, the system 100 includes turbines 102 and 114, pumps 105 and 111, and condenser 110. Further, the system 100 includes stream separator 112 and stream mixer 113.
The condenser 110 may be any type of known heat rejection device. For example, the condenser 110 may take the form of a heat exchanger, such as a water cooled system, or another type of condensing device.
As shown in FIG. 1, geofluid consisting of geothermal liquid (brine) and geothermal steam leaving the geothermal well is sent into gravity separator 101, where geothermal liquid and geothermal steam are separated. Steam leaves separator 101 with parameters as at point 41, and liquid leaves separator 101, with parameters as at point 51. Thereafter, the steam is sent into steam turbine 102 where it expands, producing power which is converted into electric power, and leaves turbine 102 with parameters as at point 43. The steam is then sent into heat exchanger 103 where it condenses, releasing its heat of condensation and being completely condensed. The condensate leaves heat exchanger 103 with parameters as at point 44. Heat from the condensation of the steam is transferred in heat exchanger 103 to the working fluid of the power cycle.
The geothermal liquid, with parameters as at point 51, is cooled in heat exchanger 104, which it leaves with parameters as at point 52 and transfers heat to the working fluid of the power cycle. The temperature of the steam condensate at point 44 is substantially equal to the temperature of the geothermal liquid at point 52. The steam condensate with parameters as at point 44 is pumped by a pump 105 to a pressure equal to that of the geothermal liquid at point 52, obtaining parameters as at point 45. Thereafter, the steam condensate with parameters corresponding to point 45 is combined with the geothermal liquid with parameters corresponding to point 52, obtaining parameters as at point 53.
The combined liquid having parameters as at point 53 passes through heat exchanger 106 where it is further cooled, releasing heat which is transferred to the working fluid of the power cycle and obtaining parameters as at point 56. Finally, liquid with parameters as at point 56 passes through heat exchanger 107 where it is further cooled, releasing heat which is transferred to the working fluid of the power cycle and obtaining parameters as at point 57. Thereafter, geothermal liquid is removed from the system and reinjected into the geothermal strata.
From the above discussion, it can be seen that the thermodynamic power cycle according to the invention utilizes two sources of geothermal heat, i.e., heat released in the process of condensation of geothermal steam and heat released by the cooling of liquid and steam condensate (geothermal liquid). The power cycle operates as follows.
The fully condensed working fluid of the power cycle with parameters as at point 21 passes through a recuperative preheater 109 where it is preheated up to boiling temperature and exits preheater 109 with parameters as at point 60. Thereafter, the working fluid is divided into two substreams at stream separator 112 having parameters, correspondingly, as at points 61 and 62. The first substream with parameters as at point 61 passes through heat exchanger 107, where it is heated by a stream of liquid geofluid and partially evaporated. It leaves heat exchanger 107 with parameters as at point 63.
The second substream having parameters as at point 62 passes through heat exchanger 108 where it is also heated and partially evaporated. It leaves heat exchanger 108 with parameters as at point 64. Thereafter, both substreams are combined at stream mixer 113, obtaining parameters as at point 66. The combined substreams are then sent into heat exchanger 106 where further evaporation occurs using heat transferred from a stream of liquid geofluid.
The temperature difference between the boiling point of the working fluid having parameters at point 62 and the temperature of the condensing working fluid stream at point 38 is minimized. However, the temperature difference between the initial boiling temperature and final temperature of the geothermal liquid used for evaporation in heat exchanger 107 can significantly exceed the minimum temperature difference between points 62 and 38 in heat exchanger 108. Thus, it is possible to optimize temperature and corresponding pressure at point 60 even where the geothermal liquid can only be cooled to relatively high temperatures because of a high degree of mineralization.
The working fluid leaves heat exchanger 106 having parameters as at point 69 and enters heat exchanger 103, where evaporation is completed using heat produced by condensation of the geothermal steam. The working fluid leaves heat exchanger 103 with parameters as at point 68 and enters heat exchanger 104, where it is superheated by a stream of geothermal liquid. Thereafter, the working fluid, which leaves heat exchanger 104 with parameters as at point 30, enters turbine 114 where it is expanded, producing power. The expanded working fluid stream then leaves turbine 114 with parameters as at point 36.
The expanded working fluid at point 36 is usually in the form of a dry or a wet saturated vapor. It then passes through heat exchanger 108 where it is partially condensed. The heat released during condensation is utilized for an initial boiling of the liquid working fluid. Thereafter, the expanded working fluid leaves heat exchanger 108 with parameters as at point 38 and passes through heat exchanger 109, where it is further condensed. The heat of condensation is utilized to preheat oncoming working fluid. The partially condensed working fluid with parameters as at point 29 leaves heat exchanger 109 and enters heat exchanger 110, where it is fully condensed, obtaining parameters as at point 14. Condensation can be provided by cooling water, cooling air, or any other cooling medium. The condensed working fluid is then pumped to a higher pressure by pump 111, obtaining parameters as at point 21. The cycle is then repeated.
The pressure at point 43 to which geothermal steam is expanded is chosen to achieve maximum total power output from both steam turbine 102 and working fluid turbine 114. The composition of the multicomponent working fluid (which includes a lower boiling point fluid and a higher boiling point fluid) is similarly chosen to maximize total power output. Specifically, the composition is chosen such that the temperature at which the expanded working fluid having parameters at point 36 condenses is higher than the temperature at which the same working fluid having parameters at point 60 boils. Examples of suitable multicomponent working fluids include an ammonia-water mixture, two or more hydrocarbons, two or more freons, mixtures of hydrocarbons and freons, or the like. In a particularly preferred embodiment, a mixture of water and ammonia is used. The multicomponent working stream preferably includes about 55% to about 95% of the low-boiling component.
Preferred parameters for the points corresponding to the points set forth in FIG. 1 are presented in Table I for a system having a water-ammonia working fluid stream. From the data it follows that the proposed system increases output in comparison with a traditional steam system by 1.55 times, and in comparison with a system that separately utilizes heat from brine and steam by 1.077 times.
TABLE I__________________________________________________________________________# P psiA X T °F. H BTU/lb G/G30 Flow lb/hr Phase__________________________________________________________________________14 112.71 .7854 78.00 -12.37 1.0000 2,682,656 SatLiquid21 408.10 .7854 78.00 -11.12 1.0000 2,682,656 Liq 90°23 • Water 70.00 38.00 14.8173 39,749,69424 • Water 94.70 62.70 14.8173 39,749,69429 113.01 .7854 133.62 353.56 1.0000 2,682,656 Wet .403730 385.10 .7854 386.80 811.71 1.0000 2,682,656 Vap 67°36 113.61 .7854 240.46 724.15 1.0000 2,682,656 Wet .032138 113.31 .7854 170.00 450.61 1.0000 2,682,656 Wet .299840 113.61 .7854 244.90 755.37 1.0000 2,682,656 SatVapor41 224.94 Steam 391.80 1200.54 .1912 513,000 SatVapor43 84.77 Steam 316.09 1132.63 .1912 513,000 Vap 0°44 84.77 Steam 316.09 286.24 .1912 513,000 SatLiquid45 224.94 Steam 316.09 286.42 .1912 513,000 Vap 0°51 • Brine 391.80 305.83 1.4143 3,794,00052 • Brine 316.09 241.48 1.4143 3,794,00053 • Brine 316.09 241.48 1.6055 4,307,00056 • Brine 240.46 177.19 1.6055 4,307,00057 • Brine 170.00 117.30 1.6055 4,307,00060 393.10 .7854 165.00 85.93 1.0000 2,682,656 SatLiquid61 391.10 .7854 235.46 455.64 .2601 697,740 Wet .341262 391.10 .7854 235.46 455.64 .7399 1,984,916 Wet .341266 391.10 .7854 235.46 455.64 1.0000 2,682,656 Wet .341269 389.10 .7854 269.56 558.84 1.0000 2,682,656 Wet .224870 387.10 .7854 311.08 720.70 1.0000 2,682,656 Wet .05__________________________________________________________________________
Where the initial geofluid leaving the geothermal well contains a relatively large quantity of steam, it is preferable to expand and then condense the geothermal steam in two or more steps, rather than in one step as shown in FIG. 1. In such a case, heating and evaporation of the working fluid is performed alternately by cooling the geothermal liquid and condensing the geothermal steam.
In FIG. 2, a system which includes two stages of expansion of geothermal steam is presented. It differs from the system shown in FIG. 1 by the fact that after the first stage of expansion, part of the expanded steam with parameters as at 43 is sent into heat exchanger 103. A portion of partially expanded steam is further expanded in a second steam turbine 204 and then condensed in a second steam condenser shown as heat exchanger 203, from which it is pressurized via pump 201 and then recombined with geothermal liquid. Geothermal liquid is used to heat the working fluid of the power cycle between those two steam condensers in heat exchanger 204.
While the present invention has been described with respect to a number of preferred embodiments, those skilled in the art will appreciate a number of variations and modifications of those embodiments. For example, the number of heat exchangers may be increased or decreased. In addition, the geothermal steam may undergo more than two expansions depending on the steam content of the geofluid. Thus, it is intended that the appended claims cover all such variations and modifications as fall within the true spirit and scope of the present invention.
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A method and apparatus for implementing a thermodynamic cycle that includes: (a) expanding a gaseous working stream, transforming its energy into usable form and producing a spent working stream; (b) heating a multicomponent oncoming liquid working stream by partially condensing the spent working stream; and (c) evaporating the heated working stream to form the gaseous working stream using heat produced by a combination of cooling geothermal liquid and condensing geothermal steam.
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BACKGROUND OF THE INVENTION
The invention relates to aneroid bellows assemblies of the type used in emergency oxygen systems in aircraft. In commercial aircraft, it is required that crew members wear oxygen masks at appropriate times and that oxygen be supplied in increasing amounts if the cabin pressure is reduced below the normally maintained pressure of 11.8 psia associated with an altitude of 6,000 feet. It is also required that the rate of flow of oxygen increase substantially at pressures of less than about 7.24 psia, which corresponds to an altitude of 18,000 feet.
Aneroid assemblies capable of controlling the flow of oxygen in the above manner have been sold for many years by Scott Aviation Corp. of Lancaster, New York. Typically, such devices have included an evacuated bellows spring mounted internally of an open ended tubular housing and affixed at one of its ends to the closed end of the housing. The bellows expands axially as ambient pressure decreases. An end plate attached to the free end of the bellows spring overlies the open end rim of the housing and extends radially outwardly of the housing where it is engaged by a coil spring which encircles the housing. It is important that the coil spring the deflected a precise distance in order to insure that the movable tip end of the bellows assembly will move as necessary to control the flow of oxygen in the manner desired. Usual manufacturing tolerances in the coil spring, housing and bellows portions of the assembly are much greater than those needed to assure proper functioning of the various parts after assembly and thus, it has been necessary to sort the parts by size and selectively fit them to each other or, alternatively, to remove material from one of them. Such operations are very time consuming and expensive.
SUMMARY OF THE INVENTION
It is among the objects of the present invention to provide an aneroid bellows assembly which is much easier to assemble and calibrate than previously available units and which is also slightly more compact and lighter in weight. In the assembly of the invention, the housing end plates and the large coil spring of the prior art assembly are eliminated and replaced by a small, lightweight leaf spring and a threaded housing end adjustment ring. The adjustment ring cooperates with an adjustable leaf spring mount on the free end of the bellows spring to accommodate a large range of manufacturing tolerances in the respective parts and permit rapid and simple calibration.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial section view of the aneroid bellows assembly of the invention at sea level;
FIG. 2 is an axial section view of a prior art bellows assembly at sea level;
FIG. 3 is a perspective view of the assembly of FIG. 1;
FIG. 4 is an axial section view illustrating the positioning of the leaf spring relative to the housing in a vacuum of 7.24 psia;
FIG. 5 is a view of the assembly of FIG. 4 after the vacuum is removed;
FIG. 6 is a view of the assembly of FIG. 5 after the ring has been threaded upwardly into touching contact with the leaf spring;
FIG. 7 is a view of the bellows assembly of FIG. 1 when subjected to a vacuum of 3.98 psia, corresponding to an altitude of 32,000 feet; and
FIG. 8 is a graph illustrating the amount of bellows movement which is produced by the assembly of FIG. 1 for various degrees of absolute pressure corresponding to different altitudes.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, my improved aneroid bellows assembly is shown in is finally assembled and adjusted sea level position in FIG. 1 where the parts are shown in partial axial cross-section and in FIG. 3 where they are shown in perspective. Referring particularly to FIG. 1, the aneroid assembly 10 can be seen as including a tubular can or housing member 12 having an outer threaded end portion 14 at its upper end and an axially aligned opening 16 at its lower end. A bellows assembly indicated generally at 20 is mounted within the housing 12 and the opening 16. The bellows assembly 20 includes a bellows spring member 22 which is evacuated and closed at its upper end by an upper end plate 24 and at its lower end by a lower end plate 26. The lower end plate includes a lower abutment portion 28 which extends into the hollow interior chamber 29 of the bellows and limits the extent to which the bellows 22 may be compressed when it is evacuated. A threaded retaining portion 30 extends downwardly from the lower end plate 26 and has an evacuation tube 31 passing through its center. The lower end (not shown) of the evacuation tube 31 is compressed, cut off and soldered closed during the course of the chamber 29. A retaining ring member 32 anchors the threaded portion 30 of the bellows assembly 20 to the housing 12. After the ring 32 is assembled, an adjustable mounting shaft 34 is screwed onto the threaded portion 30 and into firm engagement with the housing 12. An adjustment slot 36, which is adapted to receive a screw driver blade is formed at the lower end of the threaded shaft 34 and permits the entire assembly 10 to be vertically, adjustably positioned in an external mounting plate (not shown). Extending upwardly from the upper end plate 24 of the bellows assembly 20 is a bellows adjustment screw 40 having an actuator tip portion 42 which controls the flow of oxygen in a device (not shown) with which the assembly 10 is used. A bellows nut assembly 46 is threaded onto the adjustment screw 40 and comprises a generally flat leaf spring portion 48 which has a recessed center portion 50 and bent end portions 52. A flat end plate member 54 is mounted in the recessed area 50 and brazed thereto as well as to an adjustment nut 56 which has threads which are complementary to those on bellows adjustment screw 40. The end plate 54 is shown as resting on the housing 12 so that the bottom end portions of the end plate 54 overlie and contact the upper end surface of the housing 12. The bent ends 52 of the leaf spring 48 are shown as resting on a rotatable adjustment ring 60 which is threadedly engaged with the threaded end portion 14 of the housing 12. Since the assembly 10 is shown in its sea level position, one can readily appreciate that the ambient pressure in combination with the vacuum within the chamber 29 is exerting a downward force on the adjustment screw 40 and the nut assembly 46 carried thereby so that the end plate 54 will bear on the housing 12 with a predetermined amount of preload force. This preload force can be increased or decreased by rotating the nut 56 so as to reduce or enlarge the space between the central portion of the leaf spring 48 and the upper portion of the end plate 24, respectively. An additional preload is placed on the bellows assembly 20 by the leaf spring 48 which is shown as being biased to a loaded position by the adjustment ring 60.
Before proceeding further to describe the manner in which the assembly 10 is calibrated, it would be well to briefly describe the use of the device. This can be best done in connection with FIG. 8 wherein a graph is illustrated plotting the inches of aneroid travel versus altitude as expressed in absolute pressure. It is well known that the absolute pressure of the atmosphere varies from 14.7 psia. at sea level to about 3.98 at 32,000 feet. It is also known that no supplemental oxygen is required at an altitude of 6,000 feet where the pressure is 11.8 psia. but that a steadily increasing amount of oxygen is required as one goes up in the atmosphere from 6,000 feet to about 18,000 feet where the pressure is 7.24 psia. As one goes above 18,000 feet, the rate at which oxygen must be supplied is much higher than at lower altitudes. In attempting to closely approximate the non-linear manner (not shown) in which oxygen should ideally be supplied, it has been determined that the straight line curves A-B and B-C in FIG. 8 are quite satisfactory and can be achieved by combining two springs which have different spring rates. It has been found that the use of a bellows spring 22 having a spring rate of 10.1 pounds per inch and a leaf spring having a spring rate of 34 pounds per inch will provide satisfactory results when the device is correctly assembled and preloaded. To correlate FIGS. 1 and 8, it can be noted that the aneroid tip 42 will move outwardly relative to the housing 12 by the approximately 0.030" distance between points A and B as a lowering of the ambient pressure from 11.8 to 7.24 psia. permits the bellows 22 to expand and remove the preloading of the leaf spring 48. Once the effect of the leaf spring is removed, the bellows 22 can expand at a much more rapid rate so that tip 42 will move the approximately 0.070" distance between points B and C as the ambient pressure decreases from 7.24 to 3.98 psia. The configuration of the assembly at 3.98 psia. is shown in FIG. 7.
To properly calibrate the bellows assembly 10 to produce the travel shown in FIG. 8, the assembly is placed in a test chamber having a pressure of 7.24 psia., as symbolized by the dotted lines in FIG. 4. The bellows nut assembly 46 is screwed along the shaft 40 until end plate 54 is 0.030" above the end surface of the housing 12. The adjusting ring 60 is backed off, as shown, so that when the device is removed from the vacuum it will assume the configuration shown in FIG. 5. The ring 60 is then threaded up to the FIG. 6 position where it exactly meets the ends 52 of the leaf spring 48. The ring 60 is then threaded upwardly another 0.030" to preload the spring 48 to the configuration shown in FIG. 1.
From the preceding discussion, the advantages of my improved aneroid bellows assembly over prior art devices such as that shown in FIG. 2 will be readily evident. The latter embodiment has elements 112, 120, 134, 140, 142, 148, 154 and 156 which correspond to similar elements 12, 20, 34, 40, 42, 48, 54 and 56 in FIG. 1. As seen in FIG. 2, element 164 is a retaining plate which functions as a radial extension of the bottom of the housing 112 and cooperates with the plate 154 affixed to nut 156 to compress the coil spring 148. As previously noted, the usual manufacturing tolerances for the spring 148, the housing 112 and the bellows 120 are much greater than those needed to assure proper functioning of the parts after assembly, thus making it necessary to spend much time and money to sort the parts by size and selectively fit them to reach each other or, alternatively, to remove material from one of them.
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Aneroid bellows assembly utilized in the emergency oxygen supply systems of aircraft includes a leaf spring mounted at its center to an adjustably positioned end fitting located on the axis of an evacuated bellows spring. The outer edges of the leaf spring are engaged with an adjustable ring threadedly mounted on the outer rim of a tubular housing member in which the bellows spring is mounted. The adjustable end fitting and ring permit elements having a substantial size tolerance to be assembled together and readily adjusted to achieve precise calibration.
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INCORPORATION BY REFERENCE
This present disclosure claims the benefit of U.S. Provisional Application No. 61/441,606, “Minimization of Crosstalk Effects in High Speed Parallel Interfaces” filed on Feb. 10, 2011, which is incorporated herein by reference in its entirety.
BACKGROUND
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A system often includes two or more circuits coupled together, and a relatively large number of signals are transmitted between the two or more circuits. In an example, a processor chip and a memory chip are assembled on a printed circuit board (PCB). The processor chip and the memory chip are coupled together by conductive materials, such as copper wires, solder bonds, and the like, that form transmitting lines to transmit, for example, control signals, status signals, address signals and data signals between the two chips. When two transmitting lines are located in close proximity to each other, a signal transmitted in one transmitting line can be affected by another signal transmitted in the other transmitting line.
SUMMARY
Aspects of the disclosure provide a method for reducing crosstalk effects. The method includes tracking data for output onto at least a first transmission line and a second transmission line, determining a combined pattern in a first signal and a second signal to be respectively transmitted by the first transmission line and the second transmission line, and setting a delay to transmit at least one of the first signal and the second signal as a function of the combined pattern.
To determine the combined pattern in the first signal and the second signal to be respectively transmitted by the first transmission line and the second transmission line, in an example, the method includes determining a combined switch pattern in the first signal and the second signal.
According to an aspect of the disclosure, the method includes receiving a coupling characteristic of the first transmission line and the second transmission line that is indicative of one of a mutual inductive coupling characteristic and a mutual capacitive coupling characteristic. Further, in an embodiment, the method includes setting the delay as a function of the combined pattern and the coupling characteristic. In an example, the method includes detecting the combined pattern that the coupling characteristic causes a timing change of the combined pattern during transmission. Then, the method includes setting the delay for transmitting the combined pattern to compensate for the timing change.
In an embodiment, the method includes periodically tuning the delay. In an example, the method includes tracking the first signal and the second signal to be transmitted to the first transmission line and the second transmission line. Further, the method includes detecting a first pattern of the first signal and a second pattern of the second signal, and determining a combined pattern defined by a combination of the first pattern and the second pattern.
Aspects of the disclosure provide an integrated circuit (IC) chip. The IC chip includes internal circuits configured to generate data for output onto at least a first transmission line and a second transmission line. Further, the IC chip includes a first interface unit coupled to the first transmission line, a second interface unit coupled to the second transmission line, and a delay controller. The first interface unit is configured to delay a first output signal by a first tunable delay and drive the delayed first output signal on the first transmission line. The second interface unit is configured to delay a second output signal by a second tunable delay and drive the delayed second output signal on the second transmission line. The delay controller is configured to track the data for output, determine a combined pattern in the first output signal and the second output signal, and set a delay of at least one of the first interface unit and the second interface as a function of the combined pattern.
In an embodiment, the first interface unit includes a first tunable delay element, the second interface unit includes a second tunable delay element, and the delay controller is configured to control the first tunable delay element and the second tunable delay element.
According to an aspect of the disclosure, the internal circuits include a data flow circuit configured to generate the first output signal and the second output signal based on the data for output. In parallel to the operation of the data flow circuit, the delay controller determines delays for transmitting the first output signal and the second output signal based on the data for output.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments of this disclosure that are proposed as examples will be described in detail with reference to the following figures, wherein like numerals reference like elements, and wherein:
FIG. 1 shows a block diagram of a printed circuit board (PCB) 100 according to the disclosure;
FIG. 2 shows a flow chart outlining a process example 200 according to an embodiment of the disclosure; and
FIG. 3 shows a flow chart outlining another process example 300 according to an embodiment of the disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
FIG. 1 shows a block diagram of a printed circuit board (PCB) 100 according to the disclosure. The PCB 100 includes an integrated circuit (IC) chip 110 , and transmission lines 150 . These elements are coupled together as shown in FIG. 1 . It is noted that the PCB 100 can include more than one IC chip, such as other IC chips 193 , and can include other devices, such as discrete transistors 191 , discrete capacitors 192 , discrete resistors 194 , connectors 195 , and the like.
The transmission lines 150 can transmit signals between the IC chip 110 and other devices, for example. The other devices can be situated on the PCB 100 , or can be situated off the PCB 100 , for example on another PCB. The transmission lines 150 generally include a plurality of sections of conductive components. In an example, a transmission line 150 includes a bond pad on the IC chip 110 , a solder bump (not shown) configured to connect the bond pad to a package substrate (not shown), a solder ball (not shown) configured to connect the package substrate to a metal land on the PCB 100 , a wire in the package substrate configured to connect the solder bump with the solder ball, a printed metal line in a layer of the PCB 100 , a via that connects the metal land to the printed metal line, and the like.
Due to various reasons, such as space limitation, routing complexity, and the like, a transmission line 150 , or a portion of the transmission line 150 can be located in a close proximity to another transmission line 150 . The transmission lines 150 in the close proximity can induce parasitic coupling effect that a signal transmitted in one of the transmission line 150 can affect another signal transmitted in the other transmission line 150 . It is noted that the parasitic coupling effect includes parasitic mutual inductive coupling and parasitic mutual capacitive coupling. The parasitic mutual inductive coupling and the parasitic mutual capacitive coupling affect signals transmissions differently.
In a parasitic mutual inductive coupling example, when a first conductive component transmits a first electrical signal, an electromagnetic field surrounding the first conductive component is created. The electromagnetic field interferes a second electrical signal transmitted by a second conductive component located in a relatively close proximity to the first conductive component, and induces noise in the second electrical signal. In an example, when both the first electrical signal and the second electrical signal switch in the same direction, the switching in the first electrical signal negatively affects the switching rate in the second electrical signal.
Further, in a parasitic mutual capacitive coupling example, the parasitic coupling effect between a first conductive component and a second conductive component located in the close proximity is parasitic mutual capacitive coupling, then a voltage change of a first electrical signal transmitted in the first conductive component can induce a voltage change in the same direction to a second electrical signal transmitted in the second conductive component.
Generally, the induced noise due to the parasitic coupling effect is referred to as crosstalk. According to an aspect of the disclosure, crosstalk is a function of distance. When two conductive components are located in a relatively close proximity, the crosstalk between two signals transmitted by the two conductive components is relatively large; and when two conductive components are far away from each other, the crosstalk between two signals transmitted by the two conductive components is relatively small.
According to another aspect of the disclosure, crosstalk depends on the electrical signals transmitted in the conductive components. In an embodiment, when an electrical signal changes value, for example, from a relatively high voltage to a relatively low voltage or from a relatively low voltage to a relatively high voltage, crosstalk is induced. When the electrical signal is relatively constant, zero crosstalk is induced.
According to another aspect of the disclosure, crosstalk effect depends on a combination of the coupling characteristic and switch patterns of the electrical signals. In an example of parasitic mutual inductive coupling, when a first electrical signal and a second electrical signal switch in the same direction, such as from a relatively high voltage to a relatively low voltage, or from a relatively low voltage to a relatively high voltage, crosstalk induced by the switching of first electrical signal causes the second electrical signal to switch slower; and when the first electrical signal and the second electrical signal switch in the opposite direction, crosstalk induced by the switching of the first electrical signal causes the second electrical signal to switch faster.
In an example of parasitic mutual capacitive coupling, when a first electrical signal and a second electrical signal switch in the same direction, such as from a relatively high voltage to a relatively low voltage, or from a relatively low voltage to a relatively high voltage, crosstalk induced by the switching of first electrical signal causes the second electrical signal to switch faster; and when the first electrical signal and the second electrical signal switch in the opposite direction, crosstalk induced by the switching of the first electrical signal causes the second electrical signal to switch slower.
It is noted that when crosstalk affects switching rate, the crosstalk induces time jitter. The time jitter varies opening and closing of data eyes, and can cause close of effective data eye, and thus can cause transmission errors.
According to an embodiment of the disclosure, the IC chip 110 is configured to adjust timings for transmitting parallel signals out of the IC chip 110 based on data patterns of the parallel signals, to compensate for the crosstalk induced switching rate change.
In the FIG. 1 example, the IC chip 110 includes internal circuits 115 , N interface units 135 (N is a positive integer), and a delay controller 120 . In an embodiment, an interface unit 135 is an input/output unit that can be configured as an output unit to drive an output signal out of the IC chip 110 onto a coupled transmission line 150 , and can be configured as an input unit to receive an input signal coming into the IC chip 110 . For simplicity, the interface units 135 are shown as output units in FIG. 1 .
In an embodiment, each interface unit 135 includes a tunable delay element (TDE) 140 with a tunable delay and an output driver 130 . The delay controller 120 provides delay control signals C- 1 to C-N to the TDEs 140 . In an example, the control signals C- 1 to C-N are digital signals, and the TDEs 140 are digitally controllable. In an example, when the interface unit 135 is configured as an output unit, the TDE 140 delays the transmission of the output signal, and the output driver 130 drives the delayed output signal onto the coupled transmission line 150 .
In an embodiment, the internal circuits 115 generate output data, such as I- 1 to I-N. Further, the internal circuits 115 includes a data flow circuit (not shown) to suitably prepare I- 1 ′ to I-N′ corresponding to the output data I- 1 to I-N, and provides I- 1 ′ to I-N′ to the interface units 135 . In an example, the data flow circuit takes couple of clock cycles to prepare I- 1 ′ to I-N′. In an embodiment, during the couple of clock cycles, the delay controller 120 determines delay adjustments for the TDE 140 based on the output signal I- 11 to I-N. It is noted that, in an embodiment, the output data I- 1 to I-N are the same as the output signals I- 1 ′ to I-N′; and in another embodiment, the output data I- 1 to I-N are different from the output signals I- 1 ′ to I-N′, but can be suitably converted to the output signals I- 1 ′ to I-N′ for transmission purpose, in an example. In another embodiment, the output data and the output signals use different data representation formats.
According to an embodiment of the disclosure, the delay controller 120 keeps track of the output data I- 1 to I-N to detect specific patterns. In an embodiment, the specific patterns are predetermined that crosstalk due to the specific pattern induces time jitter that cause closing of data eye. In an example, the specific patterns are combined switch patterns for at least two outputs, such as switching in the same direction in the same clock cycle by the two outputs, switching in the opposite direction in the same clock cycle by the two outputs, and the like. The delay controller 120 then determines delay adjustments to compensate for the crosstalk effect and then reduces time jitter.
During operation, in an example, the delay controller 120 initializes delays to add to the transmission lines 150 . In an embodiment, the PCB 100 is a component in a system. When the system is assembled together, the system is configured in a calibration mode to calibrate transmission lines delay characteristics. In an example, respective delays of the transmission lines 150 are measured based on time domain reflectometer (TDR). The measured delays are provided to the delay controller 120 , and the delay controller 120 initializes delays to add to the transmission lines 150 to compensate for the difference of the measured delays.
Then, the delay controller 120 determines coupling characteristic of the transmission lines 150 . In an embodiment, the delay controller 120 is aware of the locations of the transmission lines 150 , and determines the coupling characteristics based on the locations. In an example, the IC chip outputs eight bits in parallel. The transmission lines 150 corresponding to the eight bits are sequentially placed according to a bit order. Thus, the delay controller 120 determines that the transmission lines corresponding to, for example, adjacent bits, are in close proximity, and have a relatively high mutual coupling.
In another embodiment, the coupling characteristics are provided to the delay controller 120 . In an example, the coupling characteristics are pre-calibrated and stored in a memory on the IC chip 110 or off the IC chip 110 . Then, the coupling characteristics are suitably provided to the delay controller 120 . According to an aspect of the disclosure, the coupling characteristic also indicates whether the mutual coupling is mutual inductive coupling or mutual capacitive coupling.
Further, the delay controller 120 tracks data for output to determine a switch pattern of output signals I- 1 ′ to I-N′ to be transmitted by the transmission lines 150 . In an example, the delay controller 120 determines whether output signals to be transmitted in close proximity switch in a same clock cycle, for example. When the output signals switch in the same clock cycle, the delay controller determines delay adjustments based on the coupling characteristics and the switch pattern to compensate for crosstalk effect.
In an example, when the mutual coupling of a first transmission line 150 and a second transmission line 150 is mutual inductive coupling, crosstalk due to switching in the same direction decreases switching rate, and crosstalk due to switching in the opposite direction increases switching rate. Thus, in an example, the delay controller 120 determines a negative delay adjustment for switching in the same direction and a positive delay adjustment for switching in the opposite direction. In addition, in an example, the delay controller determines different delay adjustments for the first transmission line and the second transmission line, for example, as a function of different intrinsic delay of the two transmission lines.
Further, the delay controller 120 tunes the delays to the transmission lines 150 according to the initial delays and the delay adjustments. For example, the delay controller 120 provides the control signals CA to C-N to the TDEs 140 to tune the delay according to the initial delays and the delay adjustments.
In an embodiment of the disclosure, the delay controller 120 is configured to actively track the output data I- 1 to I-N and actively adjust the control signals C- 1 to C-N to tune the TDEs 140 to compensate for the crosstalk effect. Then, the TDEs 140 delays the output signals I- 1 ′ to I-N′ accordingly to reduce time jitter.
FIG. 2 shows a flow chart outlining a process example 200 of a delay controller, such as the delay controller 120 , according to an embodiment of the disclosure. The process starts at S 201 and proceeds to S 210 .
At S 210 , the delay controller tracks data for output to detect a combined pattern in a first signal and a second signal to be transmitted on a first transmission line and a second transmission line. In an embodiment, the delay controller is aware of location information of transmission lines, and determines that at least a portion of the first transmission line is in a close proximity of the second transmission line. In an example, a bump of the first transmission line is adjacent to a bump of the second transmission line on an IC chip. In another embodiment, the delay controller receives transmission lines coupling characteristics, and determines that the mutual coupling of the first transmission line and the second transmission line is larger than a threshold. Then, the delay controller tracks the data for output to the first transmission line and the second transmission line.
According to an embodiment of the disclosure, the delay controller is configured to detect specific combined patterns, such as switching in the same direction, switching in the opposite direction, and the like. In an example, the specific combined patterns are predetermined. In an example, crosstalk effect due to the specific combined patterns can cause time jitter, and affect opening size of data eye. Then, the delay controller detects the predetermined specific combined patterns.
At S 220 , the delay controller determines a delay adjustment as a function of the combined pattern. According to an aspect of the disclosure, the delay controller also determines the delay adjustment based on the coupling characteristics between the first transmission line and the second transmission line. According to an embodiment of the disclosure, the delay controller is configured to determine the delay adjustment to compensate for the crosstalk and thus maintain the opening size of data eye. In an example, when the mutual coupling between the first transmission line and the second transmission line is mutual capacitive coupling, switching in the same direction increases switching speed, and switching in the opposite direction decreases switching speed. Thus, delay is increased for switching in the same direction, and delay is decreased for switching in the opposite direction.
At S 230 , the delay controller tunes delays of the first transmission line and the second transmission line according to the delay adjustment. In the FIG. 1 example, the delay controller provides control signals to tunable delay elements in the interface units to adjust the delay. In an embodiment, the tunable delay elements are controlled by digital signals. The delay controller uses digital signal processing techniques to determine the digital signals to control the tunable delay elements. Then, the process proceeds to S 299 and terminates.
According to an embodiment of the disclosure, the delay controller can be implemented by various techniques. In an example, the delay controller is implemented as logic circuits to determine a delay adjustment for a signal switching, such as from a high level to a low level, to be transmitted, and set the tunable delay element according to the delay adjustment at the time to transmit the signal switching. Further, in an example, the logic circuits actively tune the tunable delay element, such as periodically, to compensate for crosstalk induced switching rate changes in order to reduce time jitter. It is noted that other suitable implementations are also contemplated.
FIG. 3 shows a flow chart outlining another process example 300 for a delay controller, such as the delay controller 120 , according to an embodiment of the disclosure.
At S 310 , the delay controller initializes delays to add to a first transmission line and a second transmission line. In an embodiment, after a system including the PCB 100 , is assembled together, the system is configured in a calibration mode to calibrate transmission lines delay characteristics. In an example, respective delays of the transmission lines are measured based on time domain reflectometer (TDR). The measured delays are provided to the delay controller, and the delay controller initializes delays to add to the first and the second transmission lines to compensate for the difference of the measured delays.
At S 320 , the delay controller determines coupling characteristic of the first and second transmission lines. In an embodiment, the delay controller is aware of the locations of the first and second transmission lines, and determines the coupling characteristics based on the locations of the transmission lines. In an example, the IC chip outputs eight bits in parallel. The transmission lines corresponding to the eight bits are placed according to a bit order. Thus, the delay controller determines that the first and second transmission lines corresponding to, for example, adjacent bits, are in close proximity, and have a relatively high mutual coupling.
In another embodiment, the coupling characteristics are provided to the delay controller. In an example, the coupling characteristics are pre-determined or pre-calibrated based on a design of the PCB 100 , and coupling characteristics are stored in a memory on the IC chip or off the IC chip. Then, the coupling characteristics are suitably provided to the delay controller. According to an aspect of the disclosure, the coupling characteristic also indicates whether the mutual coupling is mutual inductive coupling or mutual capacitive coupling.
At S 330 , in an example, the delay controller tracks data for output to determine a switch pattern of two signals to be transmitted by the first and second transmission lines. In an example, the delay controller determines whether both signals switch in a same clock cycle, for example. When both signals switch in the same clock cycle, the process proceeds to S 340 ; otherwise, the process proceeds to S 350 .
At S 340 , the delay controller determines a delay adjustment based on the coupling characteristics and the switch pattern to compensate for crosstalk effect. In an example, when the mutual coupling of the first transmission line and the second transmission line is mutual inductive coupling, crosstalk due to switching in the same direction decreases switching rate, and crosstalk due to switching in the opposite direction increases switching rate. Thus, in an example, the delay controller determines a negative delay adjustment for switching in the same direction and a positive delay adjustment for switching in the opposite direction. In addition, in an example, the delay controller determines different delay adjustments for the first transmission line and the second transmission line, for example, as a function of different intrinsic delay of the two transmission lines.
At S 350 , the delay controller tunes the delays to the first transmission line and the second transmission line according to the initial delays and the delay adjustments.
At S 360 , the delay controller determines whether there is more data for transmission. When there is more data for transmission, the process returns to S 330 ; otherwise, the process proceeds to S 399 and terminates.
According to an embodiment of the disclosure, the delay controller can be implemented by various techniques. In an example, the delay controller is implemented as logic circuits. It is noted that other suitable implementations are also contemplated.
While aspects of the present disclosure have been described in conjunction with the specific embodiments thereof that are proposed as examples, alternatives, modifications, and variations to the examples may be made. Accordingly, embodiments as set forth herein are intended to be illustrative and not limiting. There are changes that may be made without departing from the scope of the claims set forth below.
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Aspects of the disclosure provide a method for reducing crosstalk effects. The method includes tracking data for output onto at least a first transmission line and a second transmission line, determining a combined pattern in a first signal and a second signal to be respectively transmitted by the first transmission line and the second transmission line, and setting a delay to transmit at least one of the first signal and the second signal as a function of the combined pattern.
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FIELD OF THE INVENTION
The present invention relates to a method allowing one to determine at least one value for the inlet capillary pressure of a porous medium.
The method can notably be applied under operating conditions representative of geologic formations, as regards the nature of the fluids as well as the thermodynamic pressure and temperature conditions.
The potential applications of this method relate in particular to the characterization of low-permeability porous media, such as the cap rocks of an underground reservoir, within the scope of the evaluation of geologic formations as storage sites for fluids, such as hydrocarbons, CO 2 or other fluids.
BACKGROUND OF THE INVENTION
The following documents, mentioned in the course of the description hereafter, illustrate the state of the art:
Chiquet O., Broseta D. and Thibeau S., Capillary alteration of shaly caprocks by carbon dioxide , SPE 94183, 14 th Europec Conference, Madrid, Spain, 13-16 Jun. 2005; Hildenbrand, A., Schlömer S., and Krooss B., Gas breakthrough experiments on fine-grained sedimentary rocks , Geofluids Vol. 2, 3-23, 2002; Monicard R., Caractéristiques des roches réservoir—Analyse des carottes , Paris, France, Éditions Technip, 1981; and Zweigel P. et al., Towards a methodology for top seal efficacy assessment for underground CO 2 storage , 7 th International Conference on Greenhouse Gas Control Technologies, Vancouver, 5-9 Sep. 2004.
A geologic formation capable of keeping fluids (hydrocarbons for oil reservoirs, CO 2 or other gases for storage sites, . . . ) consists of a reservoir rock allowing one to collect fluids coming from a source (mother rock or injection) and of an impervious cap rock located above (at the top) of the reservoir and allowing one to prevent migration of the fluids from the reservoir to the surface. This geologic formation is then referred to as geologic trap.
The capacity of a geologic formation to store fluids, such as hydrocarbons or CO 2 for example mainly depends on the morphology of the geologic trap and on the petrophysical properties of the rocks that make up the cap layer.
In general terms, the morphology of a geologic trap is evaluated by means of a geologic characterization based on geophysical data (seismic data for example), and also on data from the wells drilled in the zone (logs, cores and drill cuttings analysis, . . . ). If the geologic formation selected is not located in too hilly a zone, this type of study generally allows one to precisely determine the shape and the extent of the geologic trap.
Petrophysical characterization of the cap rocks requires specific laboratory experiments that can be very long considering the low permeability of such media (typically below 10 −4 mD). The permeability of a porous medium corresponds to its capacity to allow a fluid (liquid or gas) to flow under the effect of a pressure gradient. Among all the petrophysical properties, it is by far the inlet capillary pressure that plays the most important part in the capacity of cap rocks to maintain the fluids in the reservoir since it controls the allowable maximum storage overpressure at the top of the reservoir. In the literature, the inlet capillary pressure is also referred to as threshold capillary pressure or breakthrough pressure.
What is referred to as inlet capillary pressure is the minimum pressure difference to be imposed between a non-wetting phase and a wetting phase for the non-wetting phase to be able to start saturating the porous medium considered. The inlet capillary pressure is denoted by P c E .
The significance of the value of the inlet capillary pressure is illustrated on the reservoir scale within the scope of CO 2 storage: we consider the case of an aquifer wherein CO 2 is injected so as to reduce the emissions discharged to the atmosphere. During storage, the injected CO 2 whose density is under usual thermodynamic conditions lower than that of the water in place progressively forms a pocket located in the upper part of the reservoir. At the lower boundary of the pocket (water/CO 2 interface), the pressures in each one of the water and CO 2 phases are equal since the capillary pressure curve of the reservoir rocks does not generally exhibit a high inlet capillary pressure because these rocks have the property of readily accommodating fluids. Each one of the two phases having a different density, the pressure gradient is also different, which leads to the existence of a pressure difference between the two phases as shown in FIG. 1 . This pressure difference is directly related to a height h measured above the water/CO 2 interface. FIG. 1 illustrates the pressure difference for two heights h 1 and h 2 of the water/CO 2 interface. The abscissas represent pressures P,P CO2 for the CO 2 and P W for the pressure in the water phase. The ordinates represent height h above the interface. In the first case, the interface is at a depth point C l1 . At depth point C x , height h above the interface is h 1 . The difference between the pressures is P C (h 1 ). In the second case, the interface is at a depth point C l2 . At depth point C x , height h above the interface is h 2 .The difference between the pressures is P C (h 2 ). Within the scope of a CO 2 storage operation, height h above the interface changes from h 2 to h 1 . FIG. 1 thus shows an increase in the pressure difference imposed on the top with time, within the scope of a CO 2 storage operation.
In general terms, we write: P CO2 (h)−P W (h)=(ρ W −ρ CO2 )gh=P c (h) with:
h: the height above the water/CO 2 interface
P CO2 (h): the pressure in the CO 2 phase for a height h
P W (h): the pressure in the water phase for a height h
ρ CO2 : density of the CO 2
ρ W : density of the water
g: gravity
P c (h): the capillary pressure corresponding to a height h.
This pressure difference directly corresponds to the notion of capillary pressure. This capillary pressure P c (h) furthermore controls the value of the saturation for a given height h. P c (h) increases as a function of h as shown in FIG. 1 : the greater h, the higher the CO 2 pressure. The maximum capillary pressure in the reservoir is thus reached at the reservoir top (h=H). This value is denoted by P c T =P c (H). Since capillary continuity is provided at the reservoir/cap rocks interface, the value of the capillary pressure at the top P c T is therefore also imposed on the cap rock. Two cases can then arise:
the capillary pressure at the reservoir top is lower than the inlet capillary pressure (P c T <P c E ): the CO 2 remains confined; the capillary pressure at the reservoir top is higher than the inlet capillary pressure (P c T >P c E ): the CO 2 starts circulating in the cap rock and the water saturation in the cap layer will tend towards the value corresponding to P c T .
In practice, within the scope of fluid injections in an underground reservoir, it is advisable to take a given margin in relation to the value of the capillary pressure at the reservoir top calculated from H because the injection itself can generate dynamic overpressures that can locally lead to capillary pressures at the top that are higher than the calculated capillary pressure at the top (P c T ).
The previous reminder shows how important it is to properly evaluate the value of the inlet capillary pressure of a porous medium, for example within the scope of the storage of fluids, such as hydrocarbons, CO 2 or other fluids, in geologic traps.
There are various methods for evaluating the inlet capillary pressure P c E of a porous medium for the storage conditions (thermodynamic conditions and nature of the fluids).
There is, for example, a known technique based on the mercury porosimetry method. This method consists in converting a capillary pressure curve obtained by mercury porosimetry for the reservoir conditions by means of the following conversion formula (Monicard, 1981):
P c E ( s ) = P c E ( m ) σ s cos θ s σ m cos θ m
with:
σ m : mercury/air interfacial tension=480 mN/m
θ m : mercury/air contact angle=140°
σ s : interfacial tension for the fluids considered in the reservoir (typically CO 2 /brine within the scope of CO 2 storage)
θ s : contact angle for the fluids considered in the reservoir (typically CO 2 /brine within the scope of CO 2 storage)
P c E (s): value of the inlet capillary pressure under storage conditions
P c E (m): value of the inlet capillary pressure for the mercury porosimetry measurement conditions under ambient conditions.
Although this method allows very fast estimation of a value for the inlet capillary pressure under storage conditions, the representativity thereof can be affected because of the uncertainty as regards the wettability phenomena (contact angle θ storage ). Since the value of the contact angle is generally not known, it is selected equal to zero, which corresponds to a perfect wettability of the fluid in place. Recent experimental measurements have shown that this hypothesis could turn out to be erroneous in particular in the case of geologic storage of CO 2 (Chiquet et al., 2005). This approach can lead to significant errors in the calculation of the inlet capillary pressure.
There is also another approach, referred to as “conventional” approach, whose principle is based on the very definition of the inlet capillary pressure. This method is for example described by Monicard (1981).
During this approach, the sample to be studied is first saturated and placed in a containment cell, which allows one to work under imposed pressure and temperature conditions. The inlet end piece of the cell is then swept so as to bring the non-wetting fluid, such as CO 2 for example, for which the inlet capillary pressure is sought, just in contact with the face of the sample. A device allowing one to measure small liquid productions (either by weighing the liquids produced or by direct measurement from a fine capillary tube) is then set at the level of the outlet end piece.
The experiment then consists in increasing the pressure of the non-wetting fluid at the inlet face in successive increasing stages while monitoring the production level of the fluid saturating the sample at the outlet. The value of the inlet capillary pressure of the rock in relation to the two fluids used then corresponds to the imposed pressure for which production start of the fluid in place has been observed.
Although the principle is simple, implementation of this type of experiment is however delicate within the scope of cap rock evaluation, for the following reasons:
Length: the number of stages before the desired threshold is reached can be large since, in many cases, no realistic approximations are available before the experiment is started. On the other hand, the required waiting time for each pressure plateau is generally rather long to allow effective detection of the production at the outlet; and Accuracy: in the vicinity of the inlet capillary pressure, the non-wetting fluid invasion kinetics is particularly slow because its mobility threshold is then reached, which makes its outlet flow rate extremely low and therefore difficult to detect, all the more so since the rock studied is of low permeability.
The conventional approach thus leads to very long experiment times and rather to an overestimation of the inlet capillary pressure because of a wrong detection of the mobility threshold.
Another technique is the residual capillary pressure approach. This approach was recently proposed (Hildenbrand, 2002) to provide a faster experimental alternative in relation to the conventional approach. The porous medium test cell is prepared in the same way as for the conventional method, but it is placed between two cells C 1 and C 2 arranged on either side and containing the non-wetting fluid. A valve initially separates cell C 1 from the sample which is however in contact with cell C 2 . A pressure P 1 is initially imposed in C 1 and a lower pressure P 2 is imposed in C 2 by seeing to it that the difference between the two pressures is greater than the estimated value of the capillary pressure sought.
The valve is then opened while recording the evolution of P 1 and P 2 . A progressive decrease, then a stabilization is observed for P 1 in the course of time, which corresponds to a circulation of the non-wetting fluid towards C 2 through the sample. Similarly, pressure P 2 increases, then stabilizes. A residual differential pressure is experimentally observed between the two cells, which is interpreted as the inlet capillary pressure of the rock in relation to the fluids studied. Within the scope of this approach, it is also possible to keep P 1 constant and to monitor the evolution of P 2 only in the course of time.
This approach aroused a real fad as it was published because of the rapidity thereof and of the ease of interpretation. However, recent work has shown that it is risky to directly interpret the differential pressure measured at the end of the experiment directly in terms of inlet capillary pressure (Zweigel et al., 2005). In fact, during the experiment, the upstream part of the sample undergoes an initial drainage stage during circulation of the wetting fluid, then an imbibition stage as the differential pressure progressively decreases. The measured residual pressure therefore corresponds to a pressure at the end of an imbibition stage and not to a pressure at the start of a drainage stage like the inlet capillary pressure. Now, many experimental findings show that these two pressures are generally not equal, the differential pressure at the end of the imbibition stage being systematically lower than the inlet capillary pressure. Although interpretation of the results of this method a priori affords many advantages, it leads, as it is currently considered, to a systematic underestimation of the inlet capillary pressure value.
In relation to the methods currently used and described above, the method according to the invention allows one to obtain a result rapidly, as regards acquisition of the necessary experimental data as well as their interpretation in terms of inlet capillary pressure.
SUMMARY OF THE INVENTION
The invention relates to a method allowing one to perform at least an evaluation of the inlet capillary pressure value of a porous medium, from a displacement experiment wherein a first fluid saturating a sample of said medium is caused to flow by injection of a second fluid at the level of a face of the sample referred to as “inlet” face.
The method comprises the following stages:
applying to the sample a constant pressure allowing said second fluid to flow into said sample, drawing a curve of the volume of the first fluid expelled from said sample as a function of time; continuously measuring as a function of time a local differential pressure DP t i between said inlet face and at least one point located at a distance L i from the inlet face, this distance being greater than the distance between said inlet face and an interface between the two fluids within the sample; calculating at least one differential pressure of the first fluid DP w i by means of distance L i and of said curve determining at least one inlet capillary pressure value from local differential pressure DP t i and the differential pressure value DP w i of the first fluid.
The inlet capillary pressure value can be defined as the difference between local differential pressure DP t i and the differential pressure value DP w i of the first fluid.
According to the method, the differential pressure value DP w i of the first fluid can be calculated after a slope change of said curve and by determining this new slope.
According to an embodiment, distance L i is equal to the length of the sample and only the total differential pressure DP t between said inlet face and an opposite face of the sample is then measured.
According to another embodiment, distance L i is smaller than the length of the sample, and the position of the interfaces between the two fluids can be determined by means of local saturation measurements along the sample. Several inlet capillary pressure values can thus be determined and an uncertainty on the value of this inlet capillary pressure can be deduced therefrom.
According to the invention, it may be wise to leave a volume of first fluid upstream from the sample prior to starting injection of the second fluid. Furthermore, the total imposed differential pressure, the temperature of the fluids and the nature of the fluids can allow to restore conditions representative of oil reservoirs or of fluid storage sites.
Within the scope of gas storage for example, and notably within the scope of CO 2 storage, the first fluid can be water and the second fluid a gas.
Finally, the method can be applied to a porous medium of reservoir cap type so as to evaluate the storage capacity of a storage reservoir intended for a gaseous fluid, a hydrocarbon or CO 2 for example.
BRIEF DESCRIPTION OF THE FIGURES
Other features and advantages of the method according to the invention will be clear from reading the description hereafter of embodiments given by way of non limitative example, with reference to the accompanying figures wherein:
FIG. 1 illustrates the increase with time of the capillary pressure imposed at the top within the scope of a CO 2 storage operation;
FIG. 2 shows the experimental device used to evaluate the dynamic inlet capillary pressures according to the invention; and
FIG. 3 shows a production curve obtained within the scope of the method proposed and underlines the flow rate change observed when the non-wetting phase starts saturating the sample (decrease in the slope of the production curve, therefore in the flow rate).
DETAILED DESCRIPTION
The methods used in the profession and described above are essentially based on a “static” determination of the inlet capillary pressure value (semi-static for the residual capillary pressure method since we go through a transient flow phase), i.e. a fluid is injected, then stabilization of the outlet flow rate is monitored. From a more “dynamic” point of view, the inlet capillary pressure can also be considered to be a differential pressure between the two phases that does not contribute to the flow. Consider a sample initially saturated with a wetting fluid that is caused to flow by injecting a non-wetting fluid with a total differential pressure on the sample that is constant and equal to DP t . The pressure profile can then be split up into several parts according to the nature of the phases present in the various parts of the sample:
DP t =P g am =P w av =P g am −P g fr +P g fr −P w fr +P w fr −P w av
with:
DP t : the total differential pressure imposed on the sample
P g am : the gas pressure upstream from the sample (inlet face)
P w av : the water pressure downstream from the sample (outlet face)
P g fr : the gas pressure at the front (gas/water interface)
P w fr : the water pressure at the front (gas/water interface)
In the case considered above, the total differential pressure imposed on the sample can thus be split up into three terms:
DP t =DP g +P c fr +DP w
with:
DP g : the differential pressure (pressure drop) in the zone invaded by the gas
DP w : the differential pressure (pressure drop) in the zone that is not invaded by the gas
P c fr : the capillary pressure drop at the front which corresponds to the inlet capillary pressure: P c fr =P c E .
We can therefore write:
DP t =DP g +P c E +DP w
Consider the very beginning of the invasion of the medium by the gas (non-wetting fluid). We can then assume that:
the differential pressure in the gas zone (DP g ) is negligible considering the limited extent of this zone (and also considering the low viscosity of the fluid injected, as it is the case for CO 2 even under storage conditions); and the differential pressure in the water (DP w ) corresponds to the effective pressure difference that leads to the production of liquid in the buret at the outlet. This differential pressure DP w can therefore be directly calculated from Darcy's law for the production flow rate measured at the outlet (Q w ) and a permeability value (K) measured otherwise by means of techniques known to specialists:
Q w = K · S μ w · DP w L ⇒ DP w = μ w · L K · S Q w
with:
S: the section of the sample (known)
L: the length of the sample (known)
μ w : the dynamic viscosity of the water (known).
The method according to the invention thus allows one to evaluate the inlet capillary pressure P c E by means of the expression as follows:
P c E =DP t −DP w
It is thus possible to determine the value of the inlet capillary pressure P c E by injecting directly the non-wetting fluid (gas) and by measuring the effective flow rate of the wetting fluid at the outlet (Q w ), which allows one to calculate the differential pressure in this phase DP w . The inlet capillary pressure (P c E ) is then simply obtained by calculating the difference between the total differential pressure imposed on the sample (DP t ) and the value of the differential pressure in the wetting phase (DP w ).
Thus, the method according to the invention can be broken down into five major stages.
1—A non-wetting fluid, such as gas, is directly injected into a sample of section S and of length L, saturated with a wetting fluid, such as water, and constrained to a total differential pressure on the sample DP t .
2—The total differential pressure imposed on the sample (DP t ) is measured and a curve representing the volume of the wetting fluid expelled at the sample outlet as a function of time is drawn. This curve is a line whose slope corresponds to the reference flow rate (Q ref ).
3—The effective flow rate of the wetting fluid at the sample outlet (Q w ), which corresponds to the new slope of the curve, is calculated from the previous curve and after a slope change thereof.
4—The differential pressure in the wetting phase DP w is calculated, for example, from Darcy's law and by means of the dimensions of the sample (L and S), the dynamic viscosity μ w , the permeability of the sample (K) and the effective flow rate of the wetting fluid at the sample outlet (Q w ).
5—The value of the inlet capillary pressure P c E is determined by calculating the difference between the total differential pressure imposed on the sample (DP t ) and the value of the differential pressure in the wetting phase (DP w ): P c E =DP t −DP w .
Experimental implementation
A sample of the porous medium whose inlet capillary pressure is to be evaluated is first saturated with a wetting fluid, then placed in a test cell known to the man skilled in the art and described for example in patent FR-2,708,742 (U.S. Pat. No. 5,679,885). What is understood to be a porous medium is any medium having pores through which a fluid can flow. The porosity can therefore have any value.
This device allows multi-flow rate displacement experiments to be carried out on a sample (E) from a porous medium. This device is diagrammatically shown in FIG. 2 . It comprises an elongate containment cell 1 that can be cylindrical, and which contains the sample to be tested E between two end pieces 7 a and 7 b. This cell is placed inside a thermostat-controlled enclosure (not shown) so as to subject the sample to be tested to a predetermined temperature T. At the outlet of one of the faces of cell 1 , an outlet end piece 3 allows the expelled fluid to be sent to a system 4 allowing to determine the volume of wetting fluid expelled. At the opposite face, the device comprises an inlet end piece 5 allowing injection of a non-wetting fluid into sample (E). At the level of containment cell 1 , the sample to be tested E is placed within a deformable sheath 6 and the assembly is arranged within enclosure. The annular space around sheath 6 is communicated with a source of fluid under pressure (not shown) so as to subject the sample to be tested to a predetermined pressure P. The device also includes at least one differential pressure detector CDP t between the inlet and the outlet of the sample, for measuring the differential pressure produced on the sample itself DP t . The device can comprise several such detectors, referred to as CDP 1 , CDP 2 , . . . and arranged at a respective distance from the inlet face L 1 , L 2 , . . . .
The experimental conditions are representative of the storage conditions insofar as the thermodynamic conditions, the nature of the fluids used and the state of mechanical stress (confining pressure in the test cell) are respected.
Without local saturation and pressure measurement
According to a first embodiment, the total pressure is measured without carrying out local pressure and saturation measurements.
Unlike the “conventional” method for determining the inlet capillary pressure, a significant volume of wetting fluid, typically some cubic centimeters, can be kept in inlet end piece 5 . The non-wetting fluid is then injected at an imposed pressure so that the total differential pressure DP t is higher than an “a priori” estimated inlet capillary pressure value. The wetting fluid saturating the sample is then caused to flow with two distinct periods as shown in FIG. 3 :
Period 1 : as long as the non-wetting fluid is located in the inlet end piece, the wetting fluid circulates with a motive gradient directly related to the imposed total differential pressure DP t . A linear production curve whose slope corresponds to the flow rate calculated with Darcy's law for the DP t and which thus represents the reference flow rate (Q ref ) for the imposed total differential pressure during the test is thus obtained. The flow is a single-phase flow throughout the sample; and Period P 2 : as soon as the non-wetting fluid reaches the inlet face, the Differential pressure in the wetting fluid phase decreases by the value of the inlet capillary pressure and a decrease in the production slope at the outlet is immediately observed. This slope then corresponds to the effective flow rate of the wetting fluid at the sample outlet (Q w ) allowing one to calculate the differential pressure in the wetting phase DP w .
FIG. 3 shows a curve of the volume of fluid produced (V) as a function of time in hours (T) obtained within the scope of the method proposed. Two distinct slopes can be clearly seen, which correspond first to a strictly single-phase flow in the sample (P 1 ), then to the arrival (A) of the non-wetting fluid at the inlet face, producing a reduction in the slope (P 2 ) and therefore in the production flow rate (Q w ).
The presence of the volume of wetting fluid initially located upstream from the sample is not a prerequisite within the scope of the interpretation but it contributes to the quality control of the test carried out since it allows one to establish the reference flow rate (Q ref ) just before the non-wetting fluid starts flowing through the sample.
It can furthermore be noted that if the value of DP t was selected in a too conservative way (typically below the inlet capillary pressure value), the non-wetting fluid will stop at the inlet face without compromising the success of the test. In this case, the value of DP t just has to be significantly increased to carry the test through to completion.
With local saturation and pressure measurement
According to another embodiment, a measurement of the total differential Pressure and local pressure and saturation measurements are carried out. If the test cell is provided with instrumentation allowing local pressure measurements to be performed along the sample and with a device allowing the saturation profile to be measured, it is possible to carry on with the degree of interpretation. This device is also shown in FIG. 2 .
In fact, as long as the gas front located by means of the saturation measurement, by X-rays for example (RX), is upstream from the local pressure measuring points, each one of these points can be used to apply the previous approach “locally”. The following formulas are then used, i representing the number of the local pressure detector used and L i the distance from the inlet face and the position of the detector considered:
Q
w
=
K
·
S
μ
w
DP
w
i
L
i
P
c
E
=
DP
t
i
-
DP
w
i
This approach thus allows, with a single experimentation, to obtain several values for the inlet capillary pressure of a sample, which improves determination of this parameter while giving an error range for the result obtained. This is particularly useful within the scope of larger-scale studies intended to evaluate the associated uncertainties and risks as regards a storage site.
The table hereafter allows one to compare the three methods mentioned for three different rocks (R 1 , R 2 and R 3 ):
Porosity
P c E
P c E
P c E
Type
K (mD)
(%)
conventional
residual
dynamic
R1
Chalk
1.7
40
0.9
0.2
0.8
R2
Carbonate
0.016
14.5
6
3.1
6.2
R3
Sandstone
0.0014
13
10
7.7
9.6
It can be seen that the method according to the invention provides results that are comparable to those of the conventional method. These results are however more accurate and they were obtained more rapidly than those of the conventional method.
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To perform at least an evaluation of the inlet capillary pressure value of a porous medium. From a displacement experiment on a sample of the medium, a curve of the volume of saturating fluid expelled from the sample as a function of time is drawn. The differential pressure between the inlet face and at least one point located at a distance Li from the inlet face that is greater than the distance between the inlet face and the interface between the two fluids within the sample is then continuously measured as a function of time. At least one motive pressure gradient of the first fluid is thereafter calculated by means of distance Li and of the curve. Finally, at least one value of the inlet capillary pressure is determined by calculating the difference between the differential pressure and the value of the motive pressure gradient of the expelled fluid. The method can be applied notably to production of oil reservoirs for example.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to French Application No. 1054574 filed Jun. 10, 2010, which application is incorporated herein by reference and made a part hereof.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates notably to a method for communication between an emitting motor vehicle and a target.
2. Description of the Related Art
It is commonplace to make headlight calls, for example to warn other drivers of a hazard, by rapidly and manually switching on and off, a certain number of times, the road lighting (or headlight).
In the automotive domain, numerous lighting devices use halogen or discharge lamps, notably of Xenon type.
On these devices, the headlight call usually presents the following drawbacks.
The rise time when a Xenon lamp is switched on may be relatively lengthy, which does not make it possible to make headlight flashes that are as close together as would be desired.
The rise and fall time, above all when cold, for a halogen lamp is also relatively lengthy, which raises the same type of problem as mentioned above.
Furthermore, on this type of halogen and Xenon lamps, it is difficult to provide an additional light intensity, namely a light intensity greater than the normal operating intensity.
Finally, repeated headlight calls greatly reduce the life of the lamps.
Moreover, there is a need to communicate easily, for example, between two vehicles.
SUMMARY OF THE INVENTION
The aim of the invention is notably to overcome the above-mentioned drawbacks.
Thus, the subject of the invention is a method for communication between an emitting motor vehicle and at least one target, the emitting vehicle including at least one light device, the method comprising the following step:
automatically modulating a light signal emitted by the light device for a communication between the vehicle and the target.
According to the invention, the light device is preferentially chosen from: a lighting device such as a low beam, high beam or fog beam, or, as a variant, a signalling device such as a daytime running light (DRL) or a position light.
By virtue of the invention, the communication with, for example, another vehicle, can be conducted without hindrance to the driver of the emitting vehicle.
This may be particularly advantageous in the case of a headlight call, for example, because the light pulses for this headlight call can be generated automatically, without the driver having to carry out complicated movements with his fingers which may hamper the driving.
The invention thus makes it possible to enhance safety during driving.
Preferentially, the light device comprises at least one light-emitting diode arranged to participate in the modulated light signal.
The invention thus offers various advantages.
For example, it is possible to exploit, for the implementation of the invention, the presence of light-emitting diodes (LEDs) and an associated control device that are already present on the vehicle.
Furthermore, a light-emitting diode has a rise time when switched on and a fall time when switched off that are very short compared, notably, to a halogen or discharge lamp.
Finally, an LED makes it possible to produce frequent bursts of light pulses without degrading its life, unlike, for example, a halogen lamp or a discharge lamp.
Advantageously, the modulated light signal from the light device is arranged to be perceptible to the human eye.
If necessary, the wavelength of the modulated light signal duly produced by the light device is chosen to be in the visible domain of the light spectrum.
In an exemplary implementation of the invention, the modulated light signal is modulated in light intensity, notably in a periodic manner.
Advantageously, the duly modulated light signal comprises a train of light pulses, notably of periodic light pulses of constant or progressive period, the number of pulses being, for example, between 1 and 10 per pulse train.
Preferentially, the time between two consecutive light intensity maxima is between 100 ms and 300 ms.
In an exemplary implementation of the invention, the light device is arranged to fulfill a predetermined regulatory photometric function such as road lighting, dipped lighting, a daytime running light (DRL), a position light, fog lighting.
The modulated light signal corresponds, in this case, to the modulation, for example in light intensity, of the predetermined photometric function.
If desired, the light signal is modulated so as to reach light intensity values greater than the nominal light intensity value of the associated photometric function.
Advantageously, the photometric function associated with the light device corresponds to a road lighting.
In another exemplary implementation of the invention, the light device is arranged so as to participate only in the emission of the modulated light signal, without producing any regulatory photometric function.
In an exemplary implementation of the invention, the modulated light signal has a maximum intensity that is high enough for the modulated light signal to be able to be differentiated from the ambient brightness and low enough not to be a nuisance to a person in the vicinity of the emitting vehicle.
The maximum intensity of the modulated light signal is preferentially high enough for this signal to be able to be differentiated from the regulatory photometric functions of the vehicle.
In an exemplary implementation of the invention, the automatic modulation of the light signal is generated by the light device, without the help of any mobile mechanism.
For example, the modulation of the light signal is generated electronically, notably using a microcontroller or a computer driver.
In another exemplary implementation of the invention, the modulated light signal is arranged to be imperceptible to the human eye.
For example, the light signal is modulated according to a frequency that is high enough to make the variations of its intensity invisible to the human eye.
If appropriate, the amplitude variations of the light signal are low enough for them to be imperceptible to the human eye.
If desired, the modulated light signal has a wavelength outside the visible domain of the light spectrum.
If appropriate, the target of the communication includes at least one photosensitive electronic sensor, capable of receiving the modulated light signal.
In an exemplary implementation of the invention, the target of the communication is a third-party vehicle, notably situated in the vicinity of the emitting vehicle.
In another exemplary implementation of the invention, the target of the communication is a fixed installation, such as a terminal or a relay, for example, installed on the side of a road.
If desired, the emitting vehicle includes a photosensitive electronic sensor arranged to receive a modulated light signal emitted, for a communication, by a light device of a third-party vehicle or of a fixed installation.
If appropriate, the communication is both uplink and downlink, the emitting vehicle and the target being both emitter and receiver.
Advantageously, the modulated light signal is arranged to carry at least one information item, notably binary, and the photosensitive electronic sensor of the target is linked to a processing unit capable of processing this information item.
For example, the information item carried by the modulated light signal relates:
to the environment of the emitting vehicle, for example to the traffic condition around the emitting vehicle or to climatic conditions;
to the state of the emitting vehicle, for example a failure state of the vehicle; and
to a message, for example a personal message.
In an exemplary implementation of the invention, the emission of the modulated light signal is triggered by a manual control device, that is to say, a device that can be controlled by a person. A manual control device may, if appropriate, signify a device that can be controlled by the voice of a person.
The manual control device may be a device internal to the vehicle chosen from the following nonlimiting list:
a pedal;
a hand lever;
a knob;
a handle;
a lever;
a slider;
a control wheel; and
a touch screen.
In another exemplary implementation of the invention, the control device may be external to the vehicle and chosen from the following nonlimiting list:
a remote control;
a telephone;
a PDA/smartphone; and
a computer.
In another exemplary implementation of the invention, the emission of the modulated light signal is triggered by an automatic control device.
If appropriate, the automatic control device is arranged to process an information item concerning the environment of the vehicle, such as, for example, the presence of an accident on the road.
This information concerning the environment of the vehicle may be obtained by an acquisition device, chosen for example from the following nonlimiting list:
a sensor such as, for example, a CCD;
an infrared detector;
one or more photodiodes;
a geolocation system;
an accelerometer;
a vehicle speed measurement system;
a goniometer; and
an LED.
The subject of the invention is also a system for communication between an emitting motor vehicle and a target, this system comprising:
at least one light device; and
a modulation device for automatically modulating the light signal emitted by the light device for a communication between the vehicle and the target.
The invention can be better understood from reading the following detailed description of nonlimiting exemplary implementations of the invention, and from studying the appended drawing, in which:
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIG. 1 schematically and partially represents a communication system according to an exemplary implementation of the invention;
FIG. 2 schematically and partially represents a timing diagram of a light signal emitted within the system of FIG. 1 ;
FIG. 3 schematically and partially represents a timing diagram of a light signal emitted in extra-intensity mode within the system of FIG. 1 ;
FIG. 4 schematically and partially represents a communication system using binary data, according to another exemplary implementation of the invention;
FIG. 5 schematically and partially represents a timing diagram of a light signal emitted in the system of FIG. 4 ;
FIG. 6 schematically and partially represents an emitter-receiver communication system according to another exemplary implementation of the invention; and
FIGS. 7 , 8 and 9 schematically and partially represent various control devices of a communication system according to exemplary implementations of the invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 represents a communication system 1 according to an exemplary implementation of the invention, this system 1 being mounted on an emitting vehicle Ve and enabling communication between the emitting vehicle Ve and a target 4 .
This system 1 comprises:
a light device 2 , capable of emitting a light signal S; and
a modulation device 3 , for automatically modulating the light signal S.
The target 4 is, in the example described, a road user, for example a pedestrian or a driver of another vehicle.
The light device 2 comprises at least one LED 100 .
This light device 2 is arranged to produce a regulatory ‘road lighting’ photometric function.
The automatic modulation device 3 is, for example, a microcontroller or a driver.
The automatic modulation device 3 makes it possible to modulate a light signal emitted by the light device 2 in the manner described in FIG. 2 .
As can be seen, the modulated light signal S comprises a train T of periodic light pulses, comprising, for example, 9 pulses, the period of the pulses of the train T being, for example, equal to 200 ms.
The maximum light intensity of the modulated light signal, in the example described, is substantially equal to that of the ‘road lighting’ function produced by the light device 3 .
As a variant, as can be seen in FIG. 3 , the maximum intensity of the light signal is greater than that of the ‘road lighting’ function.
For example, this maximum intensity is equal to 1.5 times that of the ‘road lighting’ function.
In the example that has just been described, the communication system 1 makes it possible to produce a signal headlight call S by automatically modulating the road lighting.
FIG. 4 represents a first communication system 51 , mounted on an emitting vehicle Ve, and a second communication system 52 , mounted on a target 4 , according to another exemplary implementation of the invention.
The systems 51 and 52 allow communication between the emitting vehicle Ve and the target 4 .
In the example described, the target 4 is a third-party vehicle or a fixed installation.
The first communication system 51 comprises:
a light device 2 , capable of emitting a light signal S;
a modulation device 3 , for automatically modulating the light signal S; and
a control unit 10 , linked to the modulation device 3 .
The light device 2 comprises at least one LED, not represented here.
The light device 2 is arranged to produce a modulated light signal S whose optical characteristics differ from any regulatory photometric function.
The wavelength of the light signal S is outside the visible spectrum of light, making this signal S imperceptible to the human eye.
The control unit 10 is arranged to generate binary information relating to the environment of the emitting vehicle, such as, for example, the road traffic condition, intended for the target 4 .
The second communication system 52 comprises:
a photosensitive electronic sensor 6 , capable of receiving the modulated light signal S; and
a processing unit 7 , linked to the sensor 6 .
The photosensitive electronic sensor 6 is, for example, a camera or a photodiode 6 .
The processing unit 7 is arranged to process the modulated light signal S in order to decode the information generated by the control unit 10 of the emitting vehicle Ve.
This processing unit 7 is, for example, a demodulator associated with a decoder.
The automatic modulation device 3 modulates a light signal emitted by the light device 2 , according to the binary information produced by the control unit 10 , in the manner described in FIG. 5 .
As can be seen in this figure, the modulated light signal S comprises a train of light pulses.
The modulation is paced at a frequency that is high enough, for example approximately 1000 Hz, to make it imperceptible to the human eye.
In the example described, the modulation used is an all-or-nothing modulation, also called ‘On-Off Keying’, in which each information bit generated by the control unit 10 is transmitted without being coded.
As a variant, other modulations may be used, in conjunction with correcting or compressing coding units.
In the example that has just been described, the communication systems 51 and 52 make it possible to transmit the binary information by automatically modulating a light signal emitted by the emitting vehicle Ve.
FIG. 6 represents a communication system 13 mounted on a vehicle Ve, according to another exemplary implementation of the invention.
The communication system 13 allows for an uplink communication between the vehicle Ve and a target 4 and a downlink communication between the vehicle Ve and the third-party emitter 9 .
The communication system 13 comprises:
a light device 8 , capable of emitting a light signal S 1 and of receiving a light signal S 2 ;
a modulation device 3 , for automatically modulating the light signal S 1 ; and
a processing unit 11 linked to the modulation device 3 .
In the example described, the third-party emitter 9 and/or the target 4 are mounted on third-party vehicles or fixed installations.
The third-party emitter 9 is capable of emitting a modulated light signal S 2 , carrying an information item intended for the emitting vehicle Ve.
The light device 8 comprises at least one LED, not represented here, and at least one photosensitive electronic sensor 101 , for receiving the signal S 2 .
The light device 8 may be arranged to produce a modulated light signal S 1 whose optical characteristics differ from any regulatory photometric function.
The wavelength of the light signal S 1 may be outside the visible spectrum of light, making this signal S 1 imperceptible to the human eye.
The processing unit 11 is arranged to:
generate binary information relating to the environment of the emitting vehicle, such as, for example, the road traffic condition, intended for the target 4 ; and
processing the modulated light signal S 2 received in order to decode the information transmitted by the third-party emitter 9 .
This processing unit 11 is, for example, a coder/decoder.
In the example that has just been described, the communication system 13 enables binary information to be transmitted to a target 4 by automatically modulating a light signal emitted by the emitting vehicle Ve and/or binary information transmitted by a third-party emitter 9 to be received and processed.
Advantageously, the target 4 and the third-party emitter 9 are incorporated in one and the same communication system, this communication system being, for example, mounted on another vehicle.
The invention therefore allows, in this case, an uplink and downlink communication between the two vehicles in order to improve driving and road safety.
FIG. 7 represents a communication system 14 mounted on a vehicle Ve, according to another exemplary implementation of the invention.
The system 14 allows for a manually triggered communication, between the emitting vehicle Ve and the target 4 .
In the example described, the target 4 is a third-party vehicle or a fixed installation.
The communication system 14 comprises:
a light device 2 , capable of emitting a light signal S;
a modulation device 3 , for automatically modulating the light signal S; and
a manual control device, mounted in the passenger compartment of the emitting vehicle Ve.
The manual control device is chosen from the following list: a button 18 , a hand lever 15 , pedals 16 , a lever 17 or a control wheel 19 .
The emission of the modulated light signal S is triggered as soon as the manual control device is activated.
In the example that has just been described, the communication system 14 allows for an automatic headlight call to be made, manually triggered, for example when a dedicated button is activated.
The invention is not limited to the manual control devices described above.
For example, FIG. 8 represents a communication system 22 mounted on an emitting vehicle Ve.
This communication system 22 is identical to the communication system 14 represented in FIG. 7 , apart from the fact that the manual control device 20 is hand-held and that a signal acquisition device 21 is provided in the emitting vehicle Ve.
The manual control device 20 is, for example, a remote control 20 , which can be used to remotely open the doors of the emitting vehicle Ve.
The signal acquisition device 21 is capable of receiving a signal from the manual control device 20 and thus of triggering, upon the detection of this signal, the emission of the modulated light signal S.
This makes it possible, for example, for the owner of the vehicle to easily identify his vehicle, for example in a car park.
In the example that has just been described, the communication system 22 can be triggered from outside the passenger compartment of the vehicle Ve.
FIG. 9 represents a communication system 25 mounted on an emitting vehicle Ve, according to another exemplary embodiment of the invention.
The communication system 25 is identical to the communication system 14 represented in FIG. 7 , apart from the fact that the associated control device is automatic.
The automatic control device is arranged to process information concerning the environment of the vehicle, such as, for example, the presence of an accident on the road.
This information concerning the environment of the vehicle may be obtained by an acquisition device, such as a geolocation system 23 or a camera 22 .
While the method herein described, and the form of apparatus for carrying this method into effect, constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changes may be made in either without departing from the scope of the invention, which is defined in the appended claims.
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A system and method for communication between an emitting motor vehicle (Ve) and at least one target, the emitting vehicle (Ve) including at least one light device, the method comprising the step of automatically modulating a light signal (S) emitted by the light device for a communication between the vehicle (Ve) and the target; and the light device being chosen from: a lighting device, a daytime running light (DRL), a position light.
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PRIORITY CLAIM
[0001] This application claims the benefit of provisional patent application Ser. No. 61/666,680, filed Jun. 29, 2012, titled “Formation of Cell Aggregates”, the contents which are incorporated herein by reference in their entirety
TECHNICAL FIELD
[0002] The invention relates to a system and method for forming cell aggregates.
BACKGROUND
[0003] Cell aggregates may be formed in various ways. For example, in Tekin et al., Stimuli-responsive microwells for formation and retrieval of cell aggregates, Lab Chip 2010, 10(18):2411-8, aggregates are formed in lithographically-created microwells. Similar microwells are described in Choi et al., Controlled-size embryoid body formation in concave microwell arrays, Biomaterials 2010, 31:4296-4303.
[0004] One problem with existing chambers for creating cell aggregates is that the chambers may not be suitable for automation. Moreover, maintaining sterility and isolation from the environment is a continuing problem.
BRIEF SUMMARY
[0005] Described herein are various inventions, particular examples of which are summarized here. In one embodiment, a cell aggregate forming chamber comprises: at least one cell inlet; at least one cell outlet; an air inlet separated from outside air through a filter sized to exclude biological organisms; a mold of non-cell adherent material, comprising a plurality of cavities; and a transparent cover over the mold, so as to provide an airtight space between the cover and the mold.
[0006] In another embodiment, a method for forming cell aggregates comprises:
[0007] providing the chamber described above; (b) injecting isolated cells into the chamber through one of the one or more cell inlets; (c) providing conditions within the chamber conducive to cell growth, thereby forming cell aggregates; and (d) extracting the cell aggregates through one of the one or more cell outlets.
[0008] Various additional embodiments, including additions and modifications to the above embodiments, are described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The accompanying drawings, which are incorporated into this specification, illustrate one or more exemplary embodiments of the inventions disclosed herein and, together with the detailed description, serve to explain the principles and exemplary implementations of these inventions. One of skill in the art will understand that the drawings are illustrative only, and that what is depicted therein may be adapted based on the text of the specification or the common knowledge within this field.
[0010] In the drawings:
[0011] FIG. 1 is a drawing of an example aggregate forming chamber.
[0012] FIG. 2 is a top view of an example aggregate forming chamber.
[0013] FIG. 3 is a cross-sectional view of an example aggregate forming chamber.
DETAILED DESCRIPTION
[0014] Various example embodiments of the present inventions are described herein in the context of forming cell aggregates.
[0015] Those of ordinary skill in the art will realize that the following detailed description is illustrative only and is not intended to be in any way limiting. Other embodiments will readily suggest themselves to such skilled persons having the benefit of this disclosure. Reference will now be made in detail to implementations as illustrated in the accompanying drawings.
[0016] In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application, safety, regulatory, and business constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.
Formation of Aggregates
[0017] In one embodiment of the present disclosure, following automated or manual cell isolation, freshly isolated cells of any type may be directly transferred to an aggregate forming chamber such as that shown in FIGS. 1-3 . Cultured cells may be placed in the chamber to form aggregates of uniform size. The chamber may contain one or more inlets and one or more outlets. Preferably, the chamber has an air filter. Preferably, the aggregate mold is made of non-cell-adherent material, and contains holes or cavities as shown. The holes or cavities are preferably cylindrical or hemispherical. The chamber may in one embodiment be formed with a clear outer casing. The use of a clear casing makes it possible to inspect the growing cell aggregates without breaking sterility.
[0018] The aggregate forming chamber may be easily incorporated into a disposable unit or cartridge, for use in an automated system. In various embodiments, this automated system may also digest tissue and/or isolate cells, such as adipose cells obtained from liposuction or other surgery.
[0019] In the aggregate forming chamber, spherical aggregates may be allowed to spontaneously form by viable/healthy cells, separating out most of apoptotic and necrotic cells in the inlet product. This system has a number of advantages. For example, it may eliminate negative effects posed by apoptotic and necrotic cells in the product. It may also provide a biomimicking 3-D environment for any types of cells. Further, it may allow accelerated recovery of cells immediately following collagenase treatment.
[0020] Following formation, the chamber can be inverted and shaken lightly to allow aggregates exit out of the holes in the mold and be collected via a syringe through an outlet. Aggregates can be further cultured within the same chamber for various applications.
[0021] The use of uniform spherical aggregates may be advantageous over aggregates of random size. For example, size restriction and uniformity prevents necrosis of cells in the core. Also, uniform size of aggregates may allow convenient dosage calculation. Further, uniform size may allow ease of identification and delivery.
[0022] The described system allows for ease of tissue construct formation with stem cells. Aggregates can be formed with undifferentiated and differentiated stem cells from various origin (bone marrow, adipose, skin, muscle, heart, nerve, etc), and these aggregates can be used as a building block and assembled together to form a three-dimensional tissue construct with and without a scaffold. Conventional in-vitro culture and differentiation of stem cells may be carried out in a 2-D culture. To fabricate a tissue construct, these differentiated cells should preferably be collected via trypsinization and seeded onto a scaffold material. During this process, some of the differentiated cells are not expected to survive and hence the cell seeding efficiency is expected to be decreased. These cells also may take a substantial amount of time to attach to the surface, occupy and fill up the void space within a construct. Following formation of cell aggregates, they can be induced to differentiate in a 3-D environment within the tissue mold and seeded onto a scaffold material. By eliminating trypsinization step and reducing the time to fill the void space, a tissue construct can be rapidly fabricated without affecting cell seeding efficiency and survival rate. In case of allogeneic or xenogenic cells, aggregates can also be immunoisolated by encapsulating in various hydrogel microsphere prior to administration.
[0023] In one embodiment, cell aggregates can be cryopreserved. Compared to individual cells in suspension, cell aggregates can be expected to improve cell survival and maintain their function during and following cryopreservation.
Stromal Vascular Fraction Cell Aggregate-Based Microtissue (SAM)
[0024] Stromal vascular fraction cell Aggregate-based Microtissue (“SAM”) is described herein as an embodiment. SAM may be advantageous over the typical use of stromal vascular fraction (“SVF”) cells. For example, SVC cell survival may be improved, after isolation. There may be accelerated and improved separation of apoptotic and necrotic cells from healthy/viable cells. The maintenance of pluripotency of stem cells within SVF cells may be improved. The maintenance/stabilization of phenotypes following induced differentiation may be improved. The secretion of growth factors, cytokines, and other proteinaceous materials may be improved. Abnormal and unintended growth of cells (abnormal gene expression and ploidity, hypertrophy, etc.) may be prevented. Cellular organization (vascularization, spatial organization, etc) may also be improved.
[0025] In one embodiment, adipose-derived stromal vascular fraction (SVF) cells aggregates can be mixed with adipose tissue for fat grafting. For conventional SVF cell-assisted fat grafting, adipose tissue may be mixed with either SVF cells in suspension or in a pellet. Retention of individual cells in suspension is expected to be poor because cells can leave the implant site as the excess fluid recedes from the graft. When cell pellet is mixed with adipose tissue, an exact dosage of the cells per unit volume of fat graft may be unclear and inconsistent. By mixing SAMs with adipose tissue, cell aggregates can be trapped within the fat graft more effectively and consequently improve their retention within the graft. Mixing a unit volume of adipose tissue with a predetermined number of SVF cell aggregates may allow a delivery of a consistent dosage throughout multiple graft injections during the procedure. SAMs can also contain microvasculatures within the aggregates, which can facilitate accelerated incorporation of SAMs into the implant area and improved graft survival. SAMs secreted increased amount of growth factors and cytokines compared to individual SVF cells, which can also improve graft survival and incorporation.
[0026] In one embodiment, SAMs can be injected by themselves or along with a filler for aesthetic and other medical procedures for skin.
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Cell aggregate forming chambers are described, suitable for automated loading and unloading, where the airtight chamber contains a mold with a plurality of cavities, where there is an inlet and an outlet for cells, and where air is filtered before it comes into the chamber. Method of using the chamber include injecting cells into the chamber, providing conditions where the cells may grow to form cell aggregates, and extracting the cell aggregates through a cell outlet.
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TECHNICAL FIELD
[0001] The embodiments of the present invention relate to the surveillance of an area, and in particular, to the detection of an intrusion in that area.
TECHNICAL PROBLEM
[0002] The proprietor or an authority in charge of an area of terrain may want to acquire information about any intrusion that takes place or has taken place therein. The area of terrain or area may be placed under surveillance. Examples of intrusion include events such as animals entering for grazing, people walking or vehicles passing through the area under surveillance. The area might be restricted due to sanitary reasons, such as is the case with an infected area, or due to safety issues, i.e. danger of collapse of a structure for example, for security reasons, or for any other reason.
SOLUTION TO PROBLEM
[0003] One way of detecting an intrusion in an area is to relate the intrusion to a change in a feature of the area. Any disturbance to the feature, say above a certain predetermined threshold of change may be proof that an intrusion has taken place. It may be possible therefore, to create an initial feature of the area and inspect that initial feature of the are area from time to time to detect whether the feature has changed.
[0004] For example, one may disperse a plurality of responsive objects onto an area of terrain to form a pattern, interrogate the area at successive intervals of time and receive returned signals from the responsive objects. The pattern of responsive objects constitutes the feature referred to hereinabove. The returned signals from the responsive objects may be observed, recorded, and saved for comparison with the signals returned by the initial feature. However, other sets of returned signals, different from the initial feature, may be selected as a reference feature for comparison instead of the initial feature.
[0005] An intrusion may be caused by one of or by a combination of animals, people and objects that have displaced or obscured, totally or partially, portions of the interrogated pattern. Should such a disturbance have occurred, then a signal such as an alarm signal might be provided to alert an interested party.
ADVANTAGEOUS EFFECTS OF INVENTION
[0006] The embodiments described hereinbelow provide simple and inexpensive means for the automatic detection of intrusion into an area. Intrusions may be detected to have happened in the past or may be monitored in real time. The detection system may be coupled together to form a link or chain of areas under surveillance. Such a link may be configured as a linear barrier or as a periphery enclosing a wide surface of terrain, which is larger than the area covered by one surveillance system.
SUMMARY OF INVENTION
[0007] The present invention provides a system and a method for interrogating and receiving successive response signals from the area and comparing the returned signals for each one interrogation to detect a change therebetween, which change is indicative of an intrusion.
[0008] The system includes a plurality of corner reflectors dispersed in a pattern in the area under surveillance and a radar system, or radar for short, configured to interrogate and receive returned signals from the area, including returned signals from the pattern of corner reflectors. Coupled to the radar, the system also includes a control unit having a processor configured to compare and detect changes in the returned signals.
[0009] Activities may include trespassing by animals, people and vehicles alone and in combination. Any disturbance, including such trespassing causes a change in returned signals from the area. Should the change in the returned signals be above a predetermined threshold, then the system may trigger an alarm signal.
[0010] To provide verification and report about the intrusion, a camera and a directional microphone may be coupled to and made operative in conjunction with the radar. When the intrusion is detected, the control unit triggers the camera and/or the directional microphone into operation to derive images of the area and/or audio signals therefrom, respectively.
[0011] The embodiments of the present invention disclose a system and a method for detecting an intrusion in an area, the system comprising a plurality of corner reflectors disposed in the area, a radar system for interrogating and receiving returned signals from the plurality of corner reflectors and receiving returned signals therefrom, and a control unit coupled to the radar system for controlling the system, the system being characterized by comprising the plurality of corner reflectors being distributed in a pattern, the radar being configured for interrogating the pattern at successively timed apart intervals, and the control unit being configured for comparing successively returned signals to signals returned from a reference interrogation to detect a change therebetween that exceeds a predetermined threshold, which change is indicative of an intrusion.
[0012] It is an object of the present invention to provide a system and a method for detecting an intrusion into an area ( 10 ). The system may comprise a plurality of corner reflectors disposed in the area and distributed in a pattern, and a radar configured for interrogating the pattern of corner reflectors at successively timed apart intervals and for receiving returned signals therefrom. The system may also comprise a control unit coupled to the radar for controlling the system and configured for comparing successively returned signals with signals returned from a reference interrogation to detect a change therebetween that exceeds a predetermined threshold, the change being indicative of an intrusion.
[0013] The plurality of corner reflectors may be disposed in a pattern of terrain range gates and may be distributed alone and in combination as selected from a group including a random pattern distribution and an ordered pattern distribution.
[0014] It is also an object of the present invention to provide at least one of both a camera and a directional microphone coupled to the control unit, and configured to derive, respectively, at least an image and at least an audio signal from the area, when an intrusion is detected. The images derived by the camera may be selected alone and in combination from a group including daylight images and nighttime images, and the nighttime images include infrared images.
[0015] It is another object of the present invention to provide the plurality of corner reflectors disposed in a configuration selected alone and in combination from a group including disposition at ground level, disposition at a same height above ground level, and disposition at different heights above ground level.
[0016] It is yet an object of the present invention to provide a control unit that is configured to derive a height of a highest above ground level obscured corner reflector, which height is indicative of a minimum height of the intrusion.
[0017] It is still an object of the present invention to provide for the change in the returned signal to occur when at least one corner reflector is detected in a disposition selected alone and in combination from a group including an obscured corner reflector and a displaced corner reflector.
[0018] Furthermore, the plurality of corner reflectors may be disposed in the area by means selected from a group including ground based means, seagoing means, and airborne means. The plurality of corner reflectors may be selected alone and in combination from a group including camouflaged corner reflectors and corner reflectors that are packaged to enhance prevention of detection by visual surveillance of the area.
[0019] It is yet another object of the present invention to provide a radar that may be disposed at a height above ground level as well as being disposed remote from the control unit.
[0020] It is one object of the present invention to provide a method for detecting an intrusion in an area by using the following steps: Distributing a plurality of corner reflectors in the area in a pattern, including a pattern of terrain range gates,
[0021] operating a radar to interrogate the plurality of corner reflectors by emitting and receiving returned signals therefrom at successively timed apart intervals, and
[0022] providing a control unit ( 40 ) coupled to the radar and operating the control unit to compare successively returned signals received by the radar from the pattern to a reference returned signal, to detect a change therebetween that exceeds a predetermined threshold, the change being indicative of an intrusion.
[0023] The method also provides for deriving a radar cross section and a voltage from returned signals received from each one of the terrain range gates.
[0024] It is a further object of the present invention to provide steps for detecting a change in the returned signals in response to at least one of the corner reflectors being detected in a disposition selected alone and in combination from a group including an obscured corner reflector and a displaced corner reflector.
[0025] It is yet a further object of the present invention to provide steps for distributing at least one corner reflector at a specific height above ground level, and for detecting a change in the returned signals in response to the at least one corner reflector being obscured by an intrusion, the specific height being indicative of a minimum height of the intrusion.
[0026] The method also includes steps for triggering an alarm signal upon detection of an intrusion.
BRIEF DESCRIPTION OF DRAWINGS
[0027] Non-limiting embodiments of the invention will be described with reference to the following description of exemplary embodiments, in conjunction with the figures, in which:
[0028] FIG. 1 is schematic view of an area of terrain interrogated by a radar, in conjunction with a camera and a directional microphone coupled thereto,
[0029] FIG. 2 is a block diagram teaching the process of operation of the interrogator,
[0030] FIG. 3 presents a row of symbolic shapes, for example, four such shapes, shown as areas that are separated away from each other, but are interrogated by a same number of interrogators,
[0031] FIG. 4 depicts a row of overlapping symbolic shapes forming a chain of links, such as four, for example, and
[0032] FIG. 5 shows a protected area encircled by a chain of overlapping symbolic shapes 10 .
DESCRIPTION OF EMBODIMENTS
[0033] With reference to FIG. 1 , the area of terrain 10 seen by a field of view FOV of an interrogator 30 may adopt various geometric shapes and sizes according to the topography of the terrain 10 and a disposition of the interrogator 30 relative to the terrain. Such geometric shapes may include a polygon, a sector of a circle, or an ellipse, or even a circle when viewed from a height above the terrain 10 .
[0034] In practice, it is possible to disperse a plurality of responders, reflectors, retro-reflectors or radiation reflectors, such as corner reflectors for example, onto a selected area of terrain to form a pattern of responders. Responders may be active or passive, but low cost passive responders may be preferred.
[0035] The corner reflectors 20 may be camouflaged or packaged in a manner allowing them to pass undetected under visual inspection, but the contrary may also be practical.
[0036] The corner reflectors 20 may be dispersed manually or automatically from the ground and/or from the water, and/or from the air. Dispersion means may be disposed on land vehicles, water-going craft and airborne vehicles. Such dispersion means may include canisters or dedicated means integrated within mortar bombs, artillery shells, airdropped bombs, unmanned aerial vehicles, rockets and missiles, and other warfare delivering means.
[0037] In operation, the corner reflectors 20 may be scattered to form a ground pattern in the area 10 under surveillance. The corner reflectors 20 may be disposed as well at a height above ground level, for example mounted on a plurality of poles erected in the area 10 , where at least one corner reflector is mounted on each pole.
[0038] Buildings, trees, or sides of a terrain irregularity may also serve to support a corner reflector disposed at a height above ground level. Corner reflectors 20 may be disposed in a height distribution selected alone and in combination from a group including a distribution at a same height and a distribution at different heights.
[0039] Corner reflectors 20 may be scattered at random, for example when scattered onto the area 10 from the air. Corner reflectors 20 may also be disposed at precise locations, for example when mounted at specific heights on poles.
[0040] A change in the returned signals, indicative of an intrusion, may be caused by at least one corner reflector 20 being displaced, partially obscured or completely obscured.
[0041] Detection of the pattern formed in the area 10 may be achieved by appropriate instrumentation or interrogator 30 able to send optical or electromagnetic interrogation signal(s) to the responders or corner reflectors 20 and to collect, save and store the returned signals reflected therefrom. A processor P running a computer program stored in a memory M on a processor readable medium may compare the returned signals, for example with the returned signals from the initial interrogation or to any other selected interrogation chosen as a reference interrogation and, when a change is detected therebetween, for example above a predetermined threshold, command an alarm signal to be provided.
[0042] The appropriate instrumentation, or interrogator 30 , may be disposed at a level above the terrain level of the area 10 under surveillance. To enhance the field of view FOV of the interrogator, the interrogator 30 may be disposed at a height above ground level that is higher than the highest disposed corner reflector 20 . Furthermore, a control unit 40 , which is coupled to the interrogator 30 , may be disposed away and remote from the interrogator. The control unit 40 may be configured to command the operation of the interrogator 30 and to receive and process signals returned from the area 10 under surveillance.
[0043] The interrogator 30 may be disposed on a static tripod, as shown in FIG. 1 , or on a pole, column, building, hill, or mountain. However, the interrogator 30 may also be disposed on a vehicle moving on land or at sea or may be carried by a balloon or an airborne craft and may operate an appropriate computer program that considers geographical displacement.
[0044] One embodiment may include a control unit 40 commanding an interrogator 30 such as a radar for example, and a plurality of corner reflectors 20 disposed in the area 10 under surveillance.
[0045] FIG. 1 shows an area 10 of a terrain that is delimited by dashed lines and is studded with corner reflectors 20 disposed in distribution therein. In operation, the interrogator 30 may interrogate the area 10 in successive range gates RG. A control unit 40 may be coupled in wired or wireless communication with the interrogator 30 . Returned signals may be processed by a processor P integrated within the interrogator 30 , or be transmitted to the control unit 40 for processing thereby.
[0046] The threshold may be predetermined as being, for example, 10% of the returned signals received from the reference interrogation. Should the change in returned signals, both an increase and a decrease, exceed the threshold, the change may be indicative of an intrusion.
[0047] At least one of a radar cross section RCS and at least one voltage may be derived from the returned signals for each range gate RG and may be computed by the processor P for various angles of the field of view FOV.
[0048] An intrusion reported when one or more of the corner reflectors 20 are disposed at a height above ground level includes additional information: a minimum height of the intrusion. For example, should an animal obscure one or more corner reflectors disposed at various heights, it may be derived that the animal had a height no less than the height of the highest obscured corner reflector.
[0049] A camera 50 and a directional microphone 60 , each one alone or both together, may be coupled to the radar 30 and be trained on the field of view FOV. When an intrusion is detected and to provide verification and report of the derived change in returned signals, the camera 50 and the directional microphone 60 derive images and audio signals, respectively. The images derived by the camera may be daylight images or nighttime composite images, for example infrared images. The audio signals may discriminate among various types of disturbances, for example between types of vehicles, animals and humans.
[0050] Corner reflectors 20 dispersed in an area 10 may be interrogated by various types of interrogators 30 , such as optical or electromagnetic radiation-emitting means operating in association with reception and collection of information returned from the reflectors. For example, an interrogator 30 may be selected as a radar operating at a frequency of 77 GHz, having a 10-15 cm antenna aperture. The radar may be configured to tilt or to rotate or both to tilt and rotate. With a corner reflector 20 of some 10 cm, which may provide a radar cross section RCS of about 15-20 m 2 , the 77 GHz radar interrogator 30 may operate effectively for hundreds of meters and even cover a range of up to 1,000 m. Such a range is possible since the corner reflectors 20 cooperate with the interrogation signals emitted by the radar 30 . Evidently, the detection of a cooperating corner reflector 20 is relatively easy when compared to the detection of a non-cooperating object, such as an animal or a poacher wanting to avoid detection, for example.
[0051] A 77 GHz radar interrogator 30 may have a power consumption of some 100 mW. When the radar interrogator 30 includes a signal processor, the power consumption may reach 2 W, and may operate autonomously for about one week, when coupled to a power supply such as for example a 50 Ah accumulator. A power supply augmented with a solar energy production panel may also be considered.
[0052] Assuming that the corner reflectors 20 are dispersed in the area 10 and that the processor P is integrated within the interrogator 30 , a simple example of the operation of the system and of the method for implementing the system is illustrated in FIG. 2 .
[0053] FIG. 2 depicts the process of operation of the interrogator 30 , starting with step 50 . In step 52 , the interrogator is activated to emit and read the returned signals as the initial returned signals and to store the initially returned signals in the memory M, which is coupled to the processor P. Thereafter in step 54 , the processor P reads input data that was previously loaded in memory or that is entered by an operator via the control unit 40 . Such input data may include a threshold value and a predetermined time delay T separating each successive interrogation operation whereby the interrogator 30 interrogates the corner reflectors 20 .
[0054] Next, in step 56 , a check is made to find out if the time t measured since a previous interrogation is equal to or greater than the predetermined time delay T. Should that not be the case, control returns to step 56 , but in the contrary, the process advances to step 58 .
[0055] In step 58 , the interrogator 30 reads and stores the returned signals in memory. As a next operation in step 60 , the processor P compares the last returned signals to the initially returned signals stored as the initial signals, and/or with other previously stored signals returned as a detected and stored signals.
[0056] It is in step 62 that a check is performed to detect whether the last returned signals exceed the threshold value. If so, control returns to step 56 , but otherwise, the process proceeds to step 64 that communicates an alarm signal to the control unit 40 and/or to any other desired destination via at least one wired and/or wireless communication link. The process ends in the last step 66 .
[0057] The detection of a ground intrusion taking place in the present or that has taken place in the past within an area 10 is not limited to one sector of a circle as illustrated in FIG. 1 . It is evident that multiple interrogators 30 may cover more than one single area that may be shaped as a sector or differently therefrom. For simplicity of description, reference will be made to a symbolic shape 10 representing the area 10 covered by one interrogator 30 .
[0058] FIG. 3 presents a row of symbolic shapes 10 , for example, four such shapes, shown as areas that are separated away from each other, but are interrogated by a same number of interrogators 30 , not shown.
[0059] Similarly, FIG. 4 depicts a row of overlapping symbolic shapes 10 forming a chain of links, such as four, for example. Coupling together of a plurality of intrusion detection systems may be applied to form a continuous chain of terrain under surveillance.
[0060] FIG. 5 shows a protected area B encircled by a chain of overlapping symbolic shapes 10 . Should an alarm signal be received from any of the interrogators 30 , not shown, that are disposed in the field for discovering an intrusion in any of the areas 10 , one may conclude that an intruder may have entered the protected area B. Such an intruder may be cattle, bears, boars, or any other animal. Optionally, intruders may be hunters or hitchhikers, on foot or riding one or more vehicles.
[0061] In the description and claims of the present application, each one of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the subject or subjects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.
[0062] It will be appreciated by persons skilled in the art, that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention is defined by the appended claims and includes both combinations and sub-combinations of the various features described hereinabove as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description.
REFERENCE SIGNS LIST
[0000]
10 area of terrain or area
20 corner reflectors
30 interrogator or radar
40 control unit
50 camera
60 directional microphone
M memory
FOV field of view
P processor
RCS radar cross section
RG range gate
T time delay
t time
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A system and a method for detecting an intrusion in an area by disposing a plurality of corner reflectors therein, interrogating and receiving successive response signals therefrom, and operating a control unit, coupled to a radar, the control unit being operative to compare and detect a change in returned signals for each one interrogation. A change to the returned signals, say above a certain threshold of change, may be proof that an intrusion had taken place.
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This application is a continuation of application Ser. No. 631,208, filed Dec. 21, 1990, now abandoned, which was a continuation of application Ser. No. 369,134, filed Jun. 21, 1989, now abandoned.
FIELD OF THE INVENTION
The present invention relates generally to nonvolatile memory cells and more particularly to a memory cell having a dielectric layer with two different thicknesses formed between two conducting layers and wherein field emission tunneling is caused to occur through the lesser dielectric thickness.
BACKGROUND OF THE INVENTION
Integrated circuit memory devices have been developed which store data for indefinite periods of time and which also have the capability of selectively changing the data stored. Of particular interest here is a nonvolatile memory device which utilizes a memory cell which is completely surrounded by a relatively thick insulating material or dielectric and is thus termed a "floating gate". Nonvolatile memory cells may be arranged, as is known in the art, to construct nonvolatile random access memories (NOVRAMs) and electrically erasable programmable read-only memories (EEPROMs). U.S. Pat. No 4,300,212 and U.S. Pat. No. 4,486,769, for example, disclose a NOVRAM and an EEPROM, respectively.
Some EEPROMs made with the so called "thin oxide" technology utilize relatively thin layers of insulating silicon dioxide with two different thicknesses. However, EEPROMs made with this technology have a region of ultra thin (80 to 150 Angstroms) dielectric through which bi-directional tunneling occurs between a smooth single crystal surface and a polysilicon layer.
The fabrication of a memory cell typically consists of depositing and patterning layers of polysilicon with layers of insulating oxide in between. Patterning may be done using conventional photolithographic techniques well known in the industry. More specifically, first polysilicon layer is formed and patterned on a first dielectric layer formed on silicon substrate. A second dielectric layer is then formed to completely surround the first polysilicon layer and to form a tunneling oxide on the surface of the first polysilicon layer. A second polysilicon layer is formed and patterned on top of the second dielectric layer. A third dielectric layer is formed on the second polysilicon layer such that the second polysilicon layer is completely surrounded by dielectric. A third polysilicon layer is then formed and patterned on top of the third dielectric layer. Finally, a fourth dielectric layer is deposited over the entire memory cell.
Typically, the first polysilicon layer is a programming electrode, the second polysilicon layer is the floating gate, and the third polysilicon layer is an erase electrode. The floating gate generally lies between the programming electrode and the erase electrode and partially overlies the former and is itself partially overlain by the latter. Beneath and insulated from the floating gate is the substrate. In one configuration, there is an electrically isolated bias electrode disposed in the substrate of opposite conductivity to the substrate. This bias electrode forms one plate of a coupling capacitor to the floating gate and is also referred to as a metallurgical "paddle". In another configuration there is no metallurgical paddle disposed in the substrate.
Programming, erasing, and retaining information on the floating gate is achieved by controlling the flow of electrons to and from the floating gate. Since the polysilicon layers are insulated from each other by the layers of oxide, the electrons must "tunnel" either from the programming electrode to the floating gate or from the floating gate to the erase electrode. The electron tunneling is controlled by the relative potentials between the electrodes and the floating gate.
The floating gate voltage operating window is defined to be the difference between the positive potential on the floating gate when the floating gate has been erased and the level of negative potential on the floating gate when the floating gate has been programmed. Favorable operating conditions are obtained when this operating window is large and remains large. As the device is alternately programmed and erased, the size of the operating window decreases, thereby shortening the remaining usable lifetime of the device. Thus, a continuing objective of floating gate devices is to increase the operating window size and to maintain that increased window size for a greater number of program and erase cycles, thereby increasing the useful lifetime of the device.
A generally desirable objective of most semiconductor devices is miniaturization. As devices become smaller, however, any misalignment of the polysilicon layers will produce changes in the capacitance between the layers which adversely affects the operation of the device.
Accordingly, it is an object of the present invention to provide a memory cell which reduces alignment sensitivity between polysilicon layers by forming a second thicker dielectric layer between the polysilicon layers in all areas except for those regions where tunneling is to occur.
It is a further object of the present invention to provide a memory cell having less sensitivity to variations in alignment or dimensions of various cell elements (linewidths) thereby providing an improved floating gate memory cell operating window over a wide range of processing variations.
It is yet a further object of the present invention to provide a memory cell having an improved operating window thereby lowering the operating voltage requirements and providing a tighter distribution of the voltages required to operate an array of memory cells.
SUMMARY OF THE INVENTION
The present invention comprises a semiconductor integrated circuit device having first and second conducting layers, wherein the first conducting layer includes a surface having a localized curvature which enhances the electric field locally such that enhanced field emission tunneling of electrons occurs from the first conducting layer through the dielectric layer to the second conducting layer when a potential difference is applied between said first and said second conducting layers. A dielectric layer is disposed between and separating the first and second conducting layers and includes a first portion having a first thickness and a second portion having a second greater thickness, such that when said potential difference is applied between the first conducting layer and the second conducting layer, field emission tunneling occurs primarily through the first portion of the dielectric layer from the first conducting layer to the second conducting layer.
The present invention also comprises a method for forming a semiconductor integrated circuit device comprising the steps of (a) forming a first conducting layer, (b) forming a dielectric layer on top of said first conducting layer, and (c) forming a second conducting layer on top of said dielectric layer, wherein the first conducting layer includes a surface having a localized curvature which enhances the electric field locally such that enhanced field emission tunneling of electrons occurs from the first conducting layer through the dielectric layer to the second conducting layer when a potential difference is applied between the first and second conducting layers, and wherein the dielectric layer includes a first portion having a first thickness and a second portion having a second greater thickness, such that when said potential difference is applied between said first conducting layer and said second conducting layer, field emission tunneling occurs primarily through the first portion of said dielectric layer from the first conducting layer to the second conducting layer.
The present invention also comprises a method for forming a semiconductor integrated circuit device comprising the steps of (a) forming a first conducting layer, (b) forming an insulating layer of a predetermined second thickness on a top surface of the first conducting layer, the formation of the insulating layer resulting in the top surface of the first conducting layer being microtextured, (c) forming a masking layer having a predetermined pattern on a top surface of the insulating layer thereby forming a pattern in the insulating layer so as to expose predetermined regions of the first conducting layer, (d) under-cutting the insulating layer by an etching process a predetermined amount interior to the edge boundaries of the masking layer, (e) etching the first conducting layer according to the predetermined pattern defined by the masking layer, (f) forming a second insulating layer on all exposed surfaces of the first conducting layer, the second insulating layer having first and second regions of different predetermined thicknesses, and (g) forming a second conducting layer over the third insulating layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view of a dual thickness interpoly oxide floating gate nonvolatile memory cell according to the present invention.
FIG. 2 is a schematic of an equivalent circuit describing the operation a floating gate nonvolatile memory cell according to the present invention.
FIGS. 3(a) and 3(b) are schematic cross-sectional views of aligned mirrored memory cells according to the present invention and misaligned mirrored memory cells, respectively.
FIGS. 4(a) to 4(f) are schematic cross-sectional views of a process to form a dual thickness dielectric layer according to the present invention.
FIGS. 5(a) to 5(d) illustrate an example of the improvement to the floating gate memory window according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A schematic cross-sectional view of a dual thickness interpoly oxide as applied to a paddleless floating gate nonvolatile memory cell according to the present invention is shown in FIG. 1 at 100. A programming electrode 110 is formed from a first polysilicon layer (poly 1), a floating gate 120 is formed from a second polysilicon layer (poly 2), and an erase electrode 130 is formed from a third polysilicon layer (poly 3). The layers are separated from each other and from substrate 140 by layers of dielectric material such as silicon dioxide. The portion of the dielectric layer between the floating gate 120 and the programming electrode 110 is a tunneling element 101 and the portion of dielectric between the erase electrode 130 and the lower portion of the floating gate 120 is a tunneling element 102. The capacitances of tunneling elements 101 and 102 are denoted by C 21 and C 32 , respectively. The capacitance between floating gate 120 and substrate 140 is denoted by C 2S (the "steering capacitance"). A ground terminal 150 is disposed in substrate 140 proximate programming electrode 110 and a bit line terminal 160 is disposed in substrate 140 proximate erase electrode 130.
By suitably treating the conducting layers, the surfaces of the floating gate and the programming electrode are microtextured to produce curved surfaces which enhance the electric field locally. This local field enhancement creates the high fields necessary to cause Fowler-Nordheim field emission tunneling with relatively low voltages applied across the tunneling dielectric. For example, a 1000 angstrom silicon dioxide layer grown on a polished single crystal substrate typically tunnels when 80-100 volts is applied across it. A similar 1000 angstrom oxide formed on textured polysilicon typically tunnels when only 10 to 20 volts is applied across the oxide. It is this field enhancement due to the localized curvature or microtexturing of the surface of the polysilicon layer that allows a relatively thick dielectric layer to be used in the present invention. These locally curved or microtextured regions may be formed on the top surface or edge surfaces of the polysilicon layers depending on the type of processes, including oxidation, following the polysilicon deposition. The amount of curvature or microtexturing is adjusted through the ensuing processes to set the desired voltage at which tunneling occurs.
An equivalent circuit describing the memory cell of FIG. 1 is shown in FIG. 2. The potentials of the polysilicon layers are given by V P1 (for poly 1), V FG (for the poly 2 floating gate), and V P3 (for poly 3). The tunneling elements are shown schematically as 201 and 202. The poly layers each form the gates of a field effect transistor with poly 3 forming the gate of a transistor 230, poly 2 forming the gate of transistor 220, and poly 1 forming the gate of transistor 210. The channel regions of these transistors 210, 220, and 230 are formed within the surface 142 of substrate 140 (as shown in FIG. 1). The bit line voltage V BIT 260, ground 250, and capacitances C 21 , C 32 , and C 2S are also shown.
The floating gate voltage operating window (also known as the memory window) is defined to be the difference between the positive potential on the floating gate when the floating gate has been erased and the level of negative potential on the floating gate when the floating gate has been programmed. Based on FIG. 2, the floating gate voltage after writing may be approximately expressed as: ##EQU1## for the erased state where (V FG ) E is the erase state floating gate voltage and (V FG ) P is the program state floating gate voltage and where V P1 and V P3 are the potentials used during the write operation. The summation over j in Equation (1) extends over the parasitic capacitances that are "seen" by the floating gate and can be cut off at any desired number depending on significance of the terms. A typical value for j is 6. Equations (2) and (3) are derived considering only the capacitance terms shown, assuming all other capacitances are sufficiently small to be ignored. The steering capacitance C 2S for this paddleless case is assumed to have the full metallurgical capacitance value of the floating gate to the substrate for the programmed state and to approach zero for the erased state. These conditions are further assumed to hold for both write and read operations. The tunneling voltages (voltages across the tunneling elements necessary to maintain the required tunneling currents during write operations) are assumed to be equal and of a value that is half of the total voltage applied between poly 3 and poly 1 during a write operation.
A memory cell with a paddle typically has a bias electrode disposed in, and of opposite conductivity to, the substrate region beneath the floating gate and the store electrode. If the capacitance between the floating gate and the paddle is given by C 2M and the remaining part of the steering capacitance is comprised of non-metallurgical channel capacitance, given by C 2C , the equations for the programmed and erased states floating gate voltages are given by ##EQU2## where C TOT =C 21 +C 32 +C 2M +C 2C , and where V BIT is the bitline voltage.
Equations (4) and (5) were derived assuming that only those capacitances appearing are significant. C 2M is also assumed to be much larger than C 2C , and that for the programmed state, C 2C is only half of its full metallurgical capacitance value, and is its full capacitance value otherwise. This assumption has been found to reasonably describe observed behavior. The tunneling voltages across each of the tunneling elements are also assumed to be equal and of a value equal to half of the total voltage applied between poly 3 and poly 1 during write (just as in the paddleless case).
Since the size of the memory window is just the erased state potential minus the programmed state potential, subtracting Equation (4) from Equation (5) gives the size S of the memory window. ##EQU3## where the expression (C 2M +1/2C 2C )/C TOT is known as the "Capacitance Coupling Efficiency."
Equation (6) shows that the size of the memory window is directly proportional to the capacitance coupling efficiency.
Thus, in order to maximize the size of the memory window of a memory cell, it is desirable to make the capacitance coupling efficiency as close to 100% as possible. That is, C 2M and C 2C should be much larger than C 32 and C 21 .
Thus, one way to increase the size of the memory window is to decrease the values of capacitances C 32 and C 21 . This can be achieved by increasing the thickness of the dielectric layers in all areas except in the regions of the first and second polysilicon layers where enhanced field emission electron tunneling is desired. Since the tunneling element capacitances C 32 and C 21 are sensitive to the thickness of the dielectric between the first and second polysilicon layers, the program/erase window will be increased if the thickness of the dielectric layers overlaying programming electrode 110 and floating gate 120 are increased.
A thicker dielectric layer also reduces the alignment sensitivity between the polysilicon layers. A thicker oxide layer means a reduced per unit area capacitance which results in a floating gate cell operating window which is less sensitive to misalignment.
In arrays of memory cells, the cells are typically mirrored around electrical contact lines. Misalignment of polysilicon layers may occur during fabrication of the cells. Aligned mirrored memory cells according to the present invention and misaligned mirrored memory cells are shown in FIGS. 3(a) and 3(b), respectively.
As shown in FIG. 3(b), the second polysilicon layer is misaligned by an amount given by ΔL. This change of relative dimension results in an increase or decrease of the corresponding interpoly capacitance. There are various components of interpoly capacitance in semiconductor devices. Of interest here is the so-called variable capacitance arising from the planar interpoly region. This capacitance is strongly dependent on misalignment. The capacitance of the planar region (flat plate capacitance) is given by: ##EQU4## where W=the width of the polysilicon overlap region
L=the length of the overlap region
t ox =the thickness of the interpoly oxide
e ox =the dielectric constant of the oxide
Utilization of a thicker dielectric oxide for a significant portion of the planar region between the polysilicon layers thus decreases the total interpoly capacitance by reducing the flat plate capacitance. It likewise reduces the sensitivity of the capacitance to misalignment (dC/dL).
Under one case of misalignment conditions of the second polysilicon layer to the first and the third layer to the second, the capacitance of one tunneling element will grow while the other shrinks. This results in a shift of the center of the operating window which is given approximately by: ##EQU5## and where V TUN is the tunneling voltage across the tunnel elements and ΔC 21 and ΔC 32 are the change in respective capacitances due to misalignment.
The shift in the operating window center occurs for the following reason. During a write operation the first polysilicon layer and the third polysilicon layer capacitively pull in opposite directions (e.g., -3 volts and +25 volts) while during read, they capacitively pull in the same direction (e.g., both go to +5 volts). Consequently, any capacitance imbalance due to misalignment will result in a floating gate memory window shift and this shift does not get compensated by the read operation bias conditions. Since in an array of memory cells the cells are mirrored around the electrical contact lines, this means that every other row of cells will have window shifts in one direction, while the other rows of cells will window shift in the opposite direction. Reference cells which track misalignment may ameliorate the situation, but there is a limit to the reference cell approach which occurs when the window is shifted so far negatively that an erased state floating gate voltage is too low to provide the necessary sensing current, or when the window shift is so positive that program cell conduction is excessive.
The dual thickness thick insulating layer of the present invention thus achieves distinct advantages over the prior art. For satisfactory levels of electron transmission to occur, some means must exist for enhancing the Fowler-Nordheim emission from the pertinent surface of the emitting conducting layer. The present invention preferably utilizes such a means comprising the formation of a microtextured surface on the emitting conducting layer. Other means for enhancing field emission by the pertinent conducting layer will be clear to those skilled in the semiconductor arts and thus are within the scope of the present invention. An example of such a means is enhanced emission from regions of the conducting layer with localized curvature, such as at corners or indentations on the surface thereof.
A process to form a dual thickness dielectric layer according to the present invention is illustrated using cross-sectional views in FIGS. 4(a) to 4(f). FIG. 4(a) shows a substrate 440 which has already undergone various conventional processing steps. Grown on top of substrate 440 is a gate oxide layer 445 of a predetermined thickness to provide the appropriate capacitance between substrate 440 and a first polysilicon layer 410 which is deposited on top of gate oxide layer 445. A thick interpoly oxide layer 450 is formed on first polysilicon layer 410. Conventional oxide layers are approximately 550 Angstroms thick. In the preferred embodiment of the present invention, thick oxide layer 450 is at least double the thickness of a conventional oxide layer. For example, the thickness of thick oxide layer 450 can be greater than or equal to 1400 Angstroms. Thick oxide layer 450 may be formed, for example by low-pressure chemical vapor deposition or thermal oxidation. In forming thick oxide layer 450 on first polysilicon layer 410, the surface of the latter becomes microtextured, producing locally curved surfaces which enhance the electric field locally such that enhanced field emission tunneling is enabled to occur from the surface of the polysilicon layer 410. A photoresist layer 460 is applied to thick oxide layer 450 in a conventional manner. FIG. 4(b) shows a conventional anisotropic oxide etch step wherein thick oxide layer 450 (of FIG. 4(a)) is etched according to a pattern established by photoresist layer 460 to form thick oxide layer 451.
FIG. 4(c) shows the step of under-cutting thick oxide layer 451 (of FIG. 4(b)) with respect to the overlying photoresist layer 460. This under-cutting is performed using conventional wet or plasma oxide etch techniques to form an under-cut thick oxide layer 452. The undercut can be uniformly done and is easily reproducible. The amount of under-cut is several times the thickness of the thick oxide layer according to the present invention. For example, the under-cut can be 0.2 to 0.3 microns. FIG. 4(d) shows the next step of the anisotropic etch of first polysilicon layer 410 (of FIGS. 4(a) to 4(c)) to form first polysilicon layer 411 which is sized to conform to the desired specifications of the memory cell being fabricated. Note that the boundaries of the photoresist layer 460 define the boundaries of etched polysilicon layer 411. Photoresist 460 (of FIGS. 4(a) to 4(d)) is then removed. FIG. 4(e) shows the process for forming tunneling oxide layers 470 by forming an insulating oxide layer over the exposed regions of first polysilicon layer 411 and first gate oxide layer 445. This results particularly in an insulating oxide layer on the shoulders of first polysilicon layer 411 contiguous with under-cut thick oxide layer 452. Note that thick oxide portion 452 can be masked during formation of oxide layer 470 or its thickness increased when layer 470 is formed, in a manner conventional in the art. Oxide layers 470 are formed so as to have a predetermined thickness that is much less than the thickness of oxide layer 450 (e.g., approximately 450 Angstroms versus 1400 Angstroms). This approach allows the precise control of the critical dimensions of the tunneling regions according to the present invention. A second polysilicon layer 420 is deposited over under-cut thick oxide layer 452, tunneling regions 470, and gate oxide layer 445 in a conventional manner as shown in FIG. 4(f).
Experimentation has shown that the increased thickness of thick oxide layer 452 reduces nominal interpoly capacitance C 32 by approximately 40% and nominal interpoly capacitance C 21 by approximately 25%. This results in two significant improvements.
First, the nominal floating gate memory window margin (erased state voltage minus program state voltage) is improved by approximately 1 volt, which is approximately an 18% improvement in memory window size. Second, memory cells fabricated according to the present invention have reduced sensitivity to misalignment by approximately a factor of 2. For example, if the interpoly oxide is four times thicker, the window center shift is only one-fourth that produced by a thinner oxide for the same misalignment. This is a result of the reduced per unit area capacitance which produces a memory window center which is less sensitive to misalignment.
An example of the improvement on the floating gate memory window is illustrated in FIGS. 5(a) to 5(d). The + and - signs denote the cell and its mirror image. FIG. 5(a) shows the values of the various capacitances as a function of poly 2 misalignment (L) for the case of a single thickness oxide layer. Capacitor C2S- is shown at 511, capacitor C21- is shown at 512, capacitor C32- is shown at 513, capacitor C2S+ is shown at 514, capacitor C21+ is shown at 515 and capacitor C332+ is shown at 516 in FIG. 5(a). FIG. 5(b) shows the capacitances according to the present invention. In FIG. 5(b), capacitor C2S- is shown at 521, capacitor C21- is shown at 522, capacitor C32- is shown at 523, capacitor C2S+ is shown at 524, capacitor C21+ is shown at 525 and capacitor C32+ is shown at 526. As can be seen, the capacitances C21, C32 according to the present invention are almost all smaller for the entire range of misalignment shown. These decreased capacitances produce a larger floating gate memory window as a function of misalignment as shown in FIGS. 5(c) and 5(d). FIGS. 5(c) and 5(d) show the floating gate voltages for the erased and programmed states of the mirrored cells for the single thickness oxide case and the dual thickness oxide of the present invention. In FIG. 5(c) ERASE- is shown at 531, PROGRAM- is shown at 532, ERASE+ is shown at 533 and PROGRAM+ is shown at 534. In FIG. 5(d), ERASE- is shown at 541, PROGRAM- is shown at 542, ERASE+ is shown at 543 and PROGRAM+ is shown at 544. Recall that the memory window is just the erased state voltage minus the programmed state voltage. It can be seen that the present invention increases the memory window size for all values of misalignment.
By reducing the interpoly capacitances with respect to the steering capacitance, the alignment sensitivity of the memory window is reduced. This allows for the use of lower write voltages to achieve comparable memory window size for a given range of misalignment or to allow more relaxed alignment tolerances for a given write voltage.
An improved nonvolatile memory cell and a process for manufacturing same has been described. It will be appreciated by those skilled in the art that the present invention is applicable to similar devices based upon electron tunneling and controlled capacitances, and that the present invention is to be limited solely by the scope of the following claims.
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A semiconductor integrated circuit device is disclosed having first and second conducting layers, with the first layer having a shape which enhances field emission tunneling off of the surface thereof. A dual thickness dielectric layer separates the conducting layers. When a potential difference is applied between the conducting layers, field emission tunneling occurs primarily through the thinner portion of the dielectric layer. A method for forming a semiconductor integrated circuit device comprises the steps of (a) forming a first conducting layer, (b) forming regions of enhanced field emission on said first conducting layer, (c) forming a second insulating layer on the first conducting layer, (d) forming a masking layer (e) undercutting the second insulating layer, (f) etching the first conducting layer according to the masking pattern, (g) forming a third insulating layer on all exposed surfaces of the first conducting layer, such that a resultant insulating layer has first and second regions of different thicknesses, and (h) forming a second conducting layer over said resultant insulating layer.
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BACKGROUND OF THE INVENTION
The invention is addressed to a process for the extraction of nonpolar constituents from natural substances including hops with the simultaneous separation of the residues of nonpolar plant protecting agents. The hop plant is named in this connection only by way of example, since the problem of removing undesirable residues occurs in numerous natural substances, whether the starting substances are cultivated or wild.
The constituents which determine the value of hops are the hop resins and hop oils. The most important hop resins, the α- and β-picric acids, as well as the other soft resins, are of a nonpolar, lypophilic character, and so are the terpenes and sesquiterpenes of hop oil. Since all these substances are relatively unstable there are many possibilities for separating and concentrating the important constituents of vegetable matter by extraction with suitable solvents (on the state of the art, see for example SANDER, W. and DRUBLEIN, B., in Brau-Industrie 1982, p. 997).
Such extractants are organic solvents, especially dichloromethane, hexane, methanol, or ethanol. Recently, the extraction of hops with highly compressed CO 2 has been described. In the process according to German Federal Pat. No. 21 27 618, CO 2 at supercritical pressure and temperature is used as the extractant. The separation of the desired substances from the solvent is then performed by reducing the density by lowering the pressure with simultaneous evaporation of the CO 2 . The CO 2 extracts thus obtained are regarded in the industrial field as especially pure and stable.
Hops are treated during their growing season from March to August with numerous plant protectives which ultimately always lead, regardless of their form, to residues, even though sometimes in minute amounts. In the Federal Republic about 40 plant protectives are presently approved for hop growing.
The residues of these plant protectives are understandably undesirable in every case, as is underlined by their intensive public discussion. Raw materials for beer-making are especially subject to critical evaluation, since beer has proven, on account of the demand for purity, to be a very sensitive food substance. Consequently, it would be considered advantageous if it were possible to produce hops and hop products of very low residue content.
It is already possible to reduce the amount of residues that occur by developing and growing disease-resistant types of hops, but freedom from residues is an unattained goal. A partial reduction can also be achieved by solvent extraction. The more selective a solvent is, the fewer are the residues that can be extracted. Results have been published on dithiocarbamate residues, for example, in Brauwelt, 1981, 825 (Nitz, S. et al.), and on heavy metals in Brauerei-Rundschau, vol. 92, July 1981, No. 7 (Schur, F. et al.). Even though it is to be assumed that the very selective and nonpolar solvent carbon dioxide has the advantage over ethanol, for example, that it does not dissolve plant protectives of a polar nature, there are a number of nonpolar protectives which can be dissolved out of the plants by CO 2 extraction. For example, in Planta medica No. 2, April 1984, pp. 171-173, there is a report on the possibility of removing plant protectives from drugs with supercritical carbon dioxide. DDT and hexachlorocyclohexane as lypophilic constituents are extracted at relatively low pressures (80-120 bar) from drugs whose value-determining substances are extracted only at higher pressures (above 150 bar), or which have, so to speak, a polar character whereby they are indissoluble in CO 2 . The authors come to the conclusion that the process described is applicable only to plants which do not contain lipophilic substances such as ethereal oils, for example.
However the substances obtained from hops are lypophilic, and thus the process described in Planta medica is not applicable to hops.
Attempts to reduce residue content have been performed with three important representatives of plant protectives;
1. Folpet (N-(trichloromethylthio)-phthalimide) and
2. Metalaxyl (D,L-N-2,6-dimethylphenyl-N-(2'-methoxyacetyl)alanine methyl ester)
as fungicides, and
3. Endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide)
as an insecticide.
Studies with folpet insecticide (N-(trichloromethylthio)phthalimide), which is used preferentially against fungus infections by Peronospora, Phomapsis, Fusicladium, Botrytis etc., have shown that, under all conditions known heretofore, both in the liquid range (e.g., 70 bar, 15° C. or 150-300 bar, 25° C.) and in the superoritical range (150-300 bar, 40°-80° C.), extraction with CO 2 is successful. Upon the necessary separation, therefore, the extract and the folpet occur together. Decontamination can be performed at 80-100 bar and 60° C. from, for example, 50 ppm in the starting hops, to 0.5 ppm. However, the advantage of the 99% removal of the residue is offset by the disadvantage that about 10 to 20% of the soluble extract goes with it. The separation of this extract containing the folpet leads to a product in which the residue is greatly concentrated, and which must be discarded. The extraction of the active substances from the hops thus decontaminated can then be performed under normal extraction conditions. Therefore, while on the one hand a virtually residue-free extract is produced, on the other hand there is an unacceptable economic disadvantage in the form of the extract produced by the decontamination.
SUMMARY OF THE INVENTION
The need thus exists for a remedy whereby fungicide residues can be separated without at the same time losing uncceptably large amounts of hop extract. A virtually complete removal of the fungicides is the object. This is achieved by the present invention, in a process of the kind referred to above, in that, in a first step of the process, the plant protective as well as other constituents which are soluble under selected conditions are extracted from natural substances with compressed gases, and in a subsequent step the dissolved mixture is passed through an adsorbent and the plant protective is removed selectively from the mixture. Thus, in the first step the extractant, especially CO 2 , is pumped through the batch of hops, and the residues of plant protectives adhering to the hops--folpet in the case of the example studied--are dissolved along with an appreciable amount of hop oils and resins. In a subsequent second step, the mixture of hop constituents and plant protectives dissolved in the first step is transferred to an autoclave that contains the adsorbent, which then binds the plant protective and retains it, while having no adsorbing action on the resins and oils of the hops. For example, the plant protective may be extracted at a low density of the solvent at a pressure between 70 and 120 bar and temperatures between 40° C. and 80° C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following table shows the adsorbing action of a number of adsorbents for folpet, and for the extracted valuable substances of the hops.
______________________________________ Adsorption ofAdsorbent Folpet Resin and Oil______________________________________Active charcoal + +Kieselgur, coarse (+) -Kieselgur, fine (+) -Celite 545 + -Celite 512 - -Silica gel 90 mesh + (-)Ion exchanger - -Aluminum oxide + +Magnesium oxide + +Sodium bentonite + (-)PVPP (polyvinylpolypyrrolidone) + -______________________________________ + Good, quantitative adsorption (+) Good, but not quantitative adsorption - No adsorption (-) Slight adsorption.
Of the agents listed in the table, Celite 545 and PVPP have proven to be well-suited, sodium bentonite, silica gel and kieselgur, less well-suited. The mixture of solvent and extracted substances, freed of the fungicide by adsorption, is separated by density reduction, e.g., by pressure reduction and carbon dioxide evaporation. This can be achieved, for example, at pressures between 40 and 60 bar and temperatures above the vapor pressure curve at which the carbon dioxide solvent is in gaseous form. The CO 2 freed from the hop constituents is then liquefied and returned to the extraction circuit. In an especially advantageous manner, the mixture is returned after the adsorption without reducing its pressure, i.e., an isobaric solvent circuit is maintained with a circulating pump. On the one hand, the compression costs are reduced, and on the other hand hop constituents are dissolved only until the solvent is saturated. When the desired plant protectives have been extracted and adsorbed, the adsorption autoclave can be taken out of the circuit and the optimum conditions can be established as they are in a normal extraction. A specifically suitable adsorbent must be found for each plant protective, one which does not act or acts but slightly on the hop constituents. The "adsorbent" can consist also of one or more agents, and a succession of several agents or a mixture is conceivable. It is also to be noted that an optimum temperature range is to be established for each adsorbent so as to prevent any possible desorption, i.e., the temperature is selected such that the adsorption/desorption equilibrium lies on the adsorption side.
The following comparative examples show the extractability of a nonpolar plant protective, such as folpet, when conventional processing is used. Hops heavily contaminated with 78.9 ppm of folpet were used. The solvents were hexane, dichloromethane, 100% ethanol, a mixture of 10% water and 90% ethanol, and carbon dioxide under three conditions. The following table shows the folpet residues in the spent hops after an exhaustive resin extraction, the folpet contents in the extracts, and, in the last column, the recovery percentages with respect to the 78.9 ppm;
______________________________________ ppm of folpet Recovery rateExtractant in spent hops in extract in % relative______________________________________Hexane 1.2 533.5 82.5Dichloromethane n.n. 429.1 76.1100% ethanol n.n. 386.5 68.690% ethanol, 10% n.n. 326.3 66.2waterCO.sub.2 /70 bar 15° C. 3.8 635.8 95.4CO.sub.2 /150 bar 25° C. 3.8 603.5 91.2CO.sub.2 /220 bar 50° C. 2.6 606.4 94.1CO.sub.2 /300 bar 50° C. 1.6 653.1 97.8______________________________________
In each of these cases tested, an exhaustive extraction of the valuable substances is accompanied by a virtually quantitative extraction of the folpet. The poor folpet recovery rates in the case of the organic solvent extractions indicate a degradation of the fungicide, which can differ in degree depending on the thermal stress during the concentration by evaporation. As it was to be expected, none of the processes is capable of producing extracts specifically only with hop constituents without the fungicide folpet.
The following comparative examples will show what possibility there is of removing the folpet in a first step by the selection of the pressure and temperature of the carbon dioxide, without on the other hand extracting valuable hop resins or oils. Carbon dioxide was pumped for 3 hours at different parameters through hop pellets contaminated with 12.6 ppm of folpet. In the following table the first column shows the residual folpet contained in the pellets after the first extraction. The second column gives the decontamination rates with respect to the initial content, and the third column indicates the relative yields of hop resins and oils, with respect to the initial content, that stay with the folpet.
______________________________________Extraction ppm of folpet % of folpet Extract yieldparameters in hop pellets removed % relative______________________________________100 bar/20° C. 0.6 95 34.3100 bar/60° C. 1.9 85 19.4 90 bar/60° C. 4.8 62 5.1 70 bar/40° C. 8.3 34 2.5______________________________________
In each case, definitely more folpet than hop resins is taken out in the purification stage. But although in the case of an effective removal of the folpet appreciable amounts of the valuable substances are extracted, which are to be considered as severely contaminated, a virtually quantitative removal of the folpet without dissolving the substances extracted would take uneconomically long and can therefore be considered only where the starting amounts are very low.
It proves to be substantially more advantageous, therefore, to bind the pesticide or pesticides onto an adsorbent without the hop resins and oils. Hop pellets with 12.6 ppm of folpet serve as examples of the process. They are decontaminated in a first step, the folpet is bound to an adsorbent, and the resin and oil content that is necessarily extracted with it is separated by density reduction. It is conceivable to pump CO 2 through the hops under normal extraction conditions (i.e., at elevated pressure). This variant proves to be advantageous especially in the case of very low starting data. In any case, however, it is recommendable after removing the pesticide to avoid the adsorption autoclave because to do so can extend the life of the adsorbent. The adsorbent in the present case was added to the batch of hop pellets in a ratio of 1:10. The results, taken together, show that it is possible by the process described to produce folpet-free extracts. The undesirable pesticide remains in the adsorbent without the formation of degradation products.
______________________________________ ppm of RelativeExtraction Adsor- folpet in ppm of folpet extractionparameters bent total ex- in the spent yield %Step 1 Step 2 in Step 1 tract hops Step 1 Step 2______________________________________220/50 220/501 h 2 h kieselgur 0.5 not detectable 63 341 h 2 h silica gel 0.3 not detectable 64 281 h 2 h bentonite 0.2 not detectable 61 351 h 2 h celite 545 n.n. not detectable 66 321 h 2 h PVPP n.n. not detectable 62 31100/60 220/50 1.5 h 2.5 h kieselgur 0.3 not detectable 10 88 1.5 h 2.5 h silica gel 0.2 not detectable 14 86 1.5 h 2.5 h bentonite 0.2 not detectable 15 82 1.5 h 2.5 h celite 545 n.n. not detectable 12 87 1.5 h 2.5 h PVPP n.n. not detectable 13 87______________________________________
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The invention relates to a process for extracting nonpolar constituents from hops with simultaneous separation of residues of nonpolar plant protectives. In a first step the plant protective as well as other ingredients that are soluble under the chosen conditions are extracted with compressed gases, and in a subsequent stage the dissolved mixture is passed through an adsorbent and the plant protective is selectively removed from the mixture.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a tilt angle adjusting device and a projector equipped with the tilt angle adjusting device. More particularly, the present invention relates to a device for adjusting the orientation of a projector.
[0003] 2. Description of the Related Art
[0004] A typical projector is equipped with a tilt angle adjusting device to adjust a longitudinal and a transverse inclination of the projector in accordance with various situations. Conventional tilt angle adjusting devices are generally classified into two types according to the tilt angle adjusting mechanism. In a tilt angle adjusting device of the first type, extending lengths of tilt feet arranged on the bottom of a housing are varied in order to incline the housing in a longitudinal and/or transverse direction. In a tilt angle adjusting device of the second type, a housing is tiltably mounted on a pedestal and tilted on the pedestal in order to incline the housing in a longitudinal and/or transverse direction.
[0005] Irrespective of which type of tilt angle adjusting device is used, a change in the longitudinal inclination of projector 100 causes a change in the projected angle of the centerline of image light in the vertical direction (referred to as a projection angle hereinafter), so that a displayed position of image 101 is moved up and down, as illustrated in FIG. 1 . On the other hand, a change in the transverse inclination of projector 100 causes a change in the projected angle of the centerline of image light in the horizontal direction (referred to as an image angle hereinafter), so that image 101 is displayed such that the upper right or the upper left portion of the image is raised, as illustrated in FIG. 2 .
[0006] FIGS. 3A to 3 D illustrate examples of projectors which are equipped with a tilt angle adjusting device according to the first type. Projectors 102 of FIGS. 3A to 3 D are commonly equipped with at least one tilt foot 105 on bottom surface 104 of housing 103 . In projector 102 illustrated in FIG. 3A , one tilt foot 105 is arranged in the front portion of bottom surface 104 , and two fixed legs 106 are arranged in the rear portion of bottom surface 104 . The term “fixed leg” used herein refers to a leg, the length of which cannot be adjusted, unlike tilt foot 105 . In projector 102 illustrated in FIG. 3B , one tilt foot 105 is arranged in the front portion of bottom surface 104 , and one tilt foot 105 and one fixed leg 106 are arranged in the rear portion of bottom surface 104 . In projector 102 illustrated in FIG. 3C , two tilt feet 105 are arranged in the front portion of bottom surface 104 , and one fixed leg 106 is arranged in the rear portion of bottom surface 104 . In projector 102 illustrated in FIG. 3D , two tilt feet 105 are arranged in the front portion of bottom surface 104 , and two fixed legs 106 are arranged in the rear portion of bottom surface 104 .
[0007] In projector 102 illustrated in FIG. 3A , tilt foot 105 can be lengthened or shortened to adjust the projection angle. In projector 102 illustrated in FIG. 3B , front and rear tilt feet 105 can be lengthened or shortened to adjust the projection angle and the image angle independently of each other. In projectors 102 illustrated in FIGS. 3C, 3D , two front tilt feet 105 can be lengthened or shortened to adjust both the projection angle and the image angle at one time.
[0008] Another example of the first type of a tilt angle adjusting device is described in the specification etc. of Japanese Patent Laid-open Publication No. 2001-42423 (Document 1). The tilt angle adjusting device described herein comprises a support leg pivotally arranged on the bottom surface of a housing of a projector; and a fixing mechanism for fixing the support leg at a desired angle. The fixing mechanism comprises an operating gear which rotates in association with pivotal movements of the support leg, and a rotating gear fixed to the housing. The operating gear usually meshes with the rotating gear. The operating gear, however, is released from engagement with the rotating gear when it slides in the horizontal direction. Specifically, as a release button is pushed, the operating gear slides in the horizontal direction away from the rotating gear to allow the operating gear to be released from engagement with the rotating gear, and to allow pivotal movement of the support leg. As the release button is released after the support leg has been pivotally moved to a desired angle, the operating gear slides in the opposite direction and comes into mesh with the rotating gear to lock the support leg.
[0009] The specification etc. of Japanese Patent Laid-open Publication No. 2004-109359 (Document 2) describes a projector which has a tilt angle adjusting device of the second type. The projector described herein is provided with a hemispherical protrusion on the bottom surface of the housing of the projector. A pedestal on which the projector is mounted has a top surface provided with a hole into which the protrusion is fitted. Thus, as the projector is placed on the pedestal such that the protrusion is fitted into the hole, the projector can be inclined to the front, back, right, and left on the pedestal, as well as rotated in the horizontal direction.
[0010] Although the tilt angle adjusting device illustrated in FIG. 3A can adjust the projection angle, it cannot adjust the image angle, and although the tilt angle adjusting device illustrated in FIG. 3B can adjust both the projection angle and image angle, it cannot adjust them at one time. Therefore, either the projection angle or the image angle must be adjusted first, then followed by the adjustment of the other. Although the tilt angle adjusting mechanisms illustrated in FIGS. 3C, 3D can adjust the projection angle and image angle at one time, they cannot adjust them independently of each other (i.e., individually). Further, to adjust the angles, any of the tilt angle adjusting devices illustrated in FIGS. 3A-3D must be lifted up to raise the tilt foot (feet), resulting in complicated and burdensome adjustment work.
[0011] The projector described in Document 1 involves complicated and burdensome work for adjustments, because the release button must be pushed each time the angle is adjusted. Further, the housing must be lifted up to raise the support leg to adjust the angle, similar to the tilt angle adjusting devices illustrated in FIGS. 3A-3D .
[0012] In the projector described in Document 2, the orientation of the housing is only maintained by the frictional resistance of the surface of the protrusion with the periphery of the hole. As such, the orientation can vary with only small force applied to the housing. Further, if the housing is inclined at an excessive angle, the frictional resistance of the surface of the protrusion with the periphery of the hole may not be sufficient to maintain the orientation of the housing. Even if the orientation is maintained, the orientation of the housing is liable to vary with any slight force.
SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to provide a tilt angle adjusting device which is capable of adjusting the orientation of a projector with highly simple operations and of ensuring that the adjusted orientation is maintained. It is another object of the present invention to provide a projector equipped with the tilt angle adjusting device.
[0014] A tilt angle adjusting device comprises a shaft configured to be fixed to a bottom surface of a housing at at least one end, and a moment transmission member connected to the shaft. The moment transmission member allows relative rotation between the shaft and the moment transmission member when a moment equal to or more than a predetermined value is applied about an axis of the shaft from the housing, and restricts the relative rotation when the moment is released.
[0015] According to one aspect of the present invention, the moment transmission member includes a leg configured to be placed on a surface on which the housing is installed. The leg is provided with part of a bearing to support the shaft. The moment transmission member also includes a plate member to press an outer peripheral surface of the shaft. The plate member forms the rest of the bearing.
[0016] As force is applied toward the bottom surface at one side of the top surface of the housing in a width direction, rotation moment is caused about the shaft which serves as a center of rotation. On the other hand, since the outer peripheral surface of the shaft is pressed against the bearing formed on the leg, a frictional resistance is caused between the outer peripheral surface of the shaft and the surface of the bearing. Therefore, as the rotation moment exceeds the frictional resistance, the shaft rotates, causing a pivotal movement of the housing fixed to the shaft. On the other hand, when no external force is applied to the top surface of the housing, or when external force is applied to the housing that only generates rotation moment that is smaller than the frictional resistance, the shaft will not rotate, so that no pivotal movement of the housing will occur.
[0017] According to another aspect of the present invention, the moment transmission member includes a first disk provided with a plurality of teeth on one side, a second disk provided with a plurality of teeth on a surface opposite to the first disk, the teeth of the second disk meshing with the teeth of the first disk, a resilient member-to press the second disk against the first disk, and a leg configured to be placed on a surface on which the housing is installed, the leg being fixed to the first disk. The shaft extends through the first disk, the second disk, and the resilient member, and is configured to restrict rotation of the second disk about an axis of the shaft. The first disk, the second disk, and the resilient member are configured such that when a moment equal to or more than a predetermined value is applied to the shaft, the second disk is moved in an axial direction of the shaft against the resilient member, to disengage the teeth of the first disk from the teeth of the second disk.
[0018] As force is applied downward from the top surface of the housing, rotating moment is caused about the shaft that is fixed to the housing. Only when this rotating moment is equal to or larger than a predetermined value, the locking state of the shaft, which is caused by the engagement of the first disk with the second disk, is released to permit the housing to pivot. Further, since the first disk is engaged with the second disk by the mesh of the teeth formed on opposite surfaces of the disks, the housing pivots by an angle corresponding to one tooth in a stepwise manner.
[0019] The housing is inclined to the left or right just by pushing the top surface of the housing with force equal to or larger than a predetermined value, consequently the image angle is adjusted. When the operator stops pushing the top surface of the housing, the housing is automatically locked and the image angle is securely maintained.
[0020] A projector according to the present invention includes the tilt angle adjusting device described above.
[0021] The above and other objects, features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings which illustrate examples of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is an explanatory diagram illustrating the adjustment of a projection angle;
[0023] FIG. 2 is an explanatory diagram illustrating the adjustment of an image angle;
[0024] FIGS. 3A to 3 D are perspective views of tilt angle adjusting devices according to prior arts;
[0025] FIG. 4 is a perspective view illustrating an embodiment of a tilt angle adjusting device equipped in a projector according to the present invention;
[0026] FIG. 5 is a cross-sectional view of the tilt angle adjusting device illustrated in FIG. 4 ;
[0027] FIG. 6 is an exploded perspective view illustrating a method for mounting the tilt angle adjusting mechanism to a projector;
[0028] FIG. 7 is a schematic rear view illustrating an embodiment of a projector according to the present invention;
[0029] FIG. 8 is a partially enlarged cross-sectional view illustrating a modification to the tilt angle adjusting device illustrated in FIG. 4 ;
[0030] FIG. 9 is an enlarged cross-sectional view illustrating another modification to the tilt angle adjusting device illustrated in FIG. 4 ;
[0031] FIG. 10 is a perspective view illustrating another embodiment of a tilt angle adjusting device equipped in a projector according to the present invention;
[0032] FIG. 11 is an exploded perspective view of the tilt angle adjusting device illustrated in FIG. 10 ;
[0033] FIG. 12 is a partially enlarged cross-sectional view illustrating the structure of the tilt angle adjusting device illustrated in FIG. 10 ; and
[0034] FIG. 13 is a partially enlarged diagram for illustrating forces acting between the teeth of a first disk and teeth of a second disk.
DETAILED DESCRIPTION OF THE INVENTION
[0035] A first embodiment of a projector according to the present invention will be described. As illustrated in FIGS. 4 and 5 , tilt angle adjusting device 1 has leg 10 , shaft 11 , and clamp plate 12 . Leg 10 has an elongate shape. Bottom surface 20 is substantially flat, and top surface 21 gradually approaches bottom surface 20 from the center of top surface 21 towards the both ends. Thus, leg 10 is tapered narrowing down in a longitudinal direction. Semi-arc shaped bearing 22 is formed at the longitudinal center of top surface 21 of leg 10 . Shaft 11 includes a round-bar shaft section 23 , and plate-shaped brackets 24 arranged at both axial ends of shaft section 23 . Semi-arc recess 25 which covers shaft section 23 of shaft 11 is formed at the center of clamp plate 12 . Flanges 26 are formed integrally with recess 25 on both ends thereof.
[0036] As clearly illustrated in FIG. 5 , a radially lower half of shaft section 23 of shaft 11 is fitted in bearing 22 of leg 10 . The remaining radially upper half of shaft section 23 that is fitted in bearing 22 of leg 10 is covered with recess 25 of clamp plate 12 . Flanges 26 of clamp plate 12 are fixed to top surface 21 of leg 10 with screws. Recess 25 has a slightly smaller radius of curvature than shaft section 23 . Therefore, the inner surface of recess 25 is pressed against the outer peripheral surface of shaft section 23 with a pressure equal to or higher than a predetermined value. As a result, frictional resistance F 1 is caused between the contact surfaces.
[0037] As illustrated in FIG. 6 , tilt angle adjusting device 1 provided with the foregoing structure is mounted in a rear portion (opposite to the plane on which a projection lens is arranged) of housing bottom surface 30 of projector 2 . Specifically, housing bottom surface 30 is provided in its rear portion with mount area 33 which forms a recess on housing 32 , with stages 34 to fix brackets 24 of shaft 11 , formed in front and at the back of mount area 33 . Brackets 24 are fixed to corresponding stages 34 with screws, not shown. In other words, leg 10 is coupled with housing 32 pivotally about shaft 11 which serves as an axis of rotation. Tilt foot 35 is provided in the front portion of the bottom surface 30 of housing, to move the front side of housing 32 in an up/down direction to adjust the projection angle (launching angle). Tilt foot 35 , which is arranged on the axis of shaft 11 , is similar to the conventional tilt foot in structure. Detailed description of tilt foot 35 is omitted.
[0038] The tilt angle can be adjusted in the following manner for projector 2 of the structure as described above. As illustrated in FIG. 7 , as force F 2 is applied downward at one of the sides of top surface 36 of housing 32 in a width direction (longitudinal direction of leg 10 ), rotation moment M 1 is caused about shaft section 23 of shaft 11 . On the other hand, frictional resistance F 1 is caused between the surfaces of bearing 22 and recess 25 and the outer peripheral surface of shaft section 23 of shaft 11 . Therefore, as rotation moment M 1 is applied, reaction moment M 2 is caused. When rotation moment M 1 becomes larger than reaction moment M 2 , housing 32 pivots about fixed leg 35 which serves as a fulcrum ( FIG. 6 ) in the direction in which rotation moment M 1 is applied (in the counter-clockwise direction in FIG. 7 ). In other words, while the relationship M 1 ≦M 2 is being established housing 32 is locked, and pivots only when the relationship M 1 >M 2 is satisfied. Thus, housing 32 is inclined to the left or right only by pushing upper surface 36 of housing 32 of projector 2 installed on a table or a desk, and the image angle of a projected image is accordingly adjusted. Further, when the pressing force is released at top surface 36 , housing 32 is automatically locked to hold the image angle.
[0039] Next, a modification to the above-described tilt angle adjusting device will be described with reference to FIG. 8 . In the tilt angle adjusting device illustrated in FIG. 8 , shaft section 23 has an axially central portion arranged between bearing 22 of leg 10 and recess 25 of clamp plate 12 . The central portion has a smaller diameter than the remaining portion of shaft section 23 . Bearing 22 and recess 25 have arcuate surfaces which are able to be in close contact with the narrowed central portion of shaft section 23 . With this structure, displacement of leg 10 in the axial direction of shaft 11 is restricted. Further, a force is constantly maintained on bearing 22 of leg 10 to ensure that bearing 22 is kept in contact with the narrowest portion of shaft section 23 . Even if any external force acts on leg 10 to displace it temporarily in the axial direction of shaft 11 , leg 10 will immediately return to the original position.
[0040] Another modification of the tilt angle adjusting device will be described with reference to FIG. 9 . In the tilt angle adjusting device illustrated in FIG. 9 , clamp plate 12 is overlaid with a second clamp plate (auxiliary clamp plate 40 ), and both plates are fastened together to leg 10 with common screws 41 , 42 . As clamp plate 12 suffers from deformation and/or creep due to aging and so on, frictional resistance may be reduced between the surface of recess 25 and the outer peripheral surface of shaft section 23 of shaft 11 , which may lower the capability to maintain the orientation of the housing, not shown. Clamp plate 12 is overlaid with auxiliary clamp plate 40 , which does not have a surface in contact with shaft section 23 , to prevent creep in clamp plate 12 . Thus, the reduction in the capability to maintain the orientation of the housing, which may result from a reduction in frictional resistance, can be avoided. It should be noted that creep is a common phenomenon with resin, and therefore, if clamp plate 12 is made of resin, this makes auxiliary clamp 40 particularly effective. Auxiliary clamp plate 40 is preferably formed of metal which is less likely to suffer from creep than resin. If auxiliary clamp plate 40 has a proper resiliency, it can usually press clamp plate 12 to shaft section 23 effectively as well as prevent creep.
[0041] Leg 10 , shaft 11 , clamp plate 12 , and brackets 24 which are of the above-mentioned structure may be entirely or partially made of resin or metal material. These components can be manufactured by an appropriate process such as molding, die casting, pressing, and the like.
[0042] A second embodiment of a projector according to the present invention will be described next. The projector of the second embodiment differs from the first embodiment only in the structure of the tilt angle adjusting device. Therefore, the following description will be focused on the structure of the tilt angle adjusting device, and description of the projector itself will be omitted.
[0043] As illustrated in FIGS. 10 and 11 , tilt angle adjusting device 50 comprises leg 51 , shaft 52 , first disk 53 , second disk 54 , resilient member 55 , spacer 56 , brackets 57 , 58 , and positioning member 59 .
[0044] Leg 51 has an elongated shape, with semi-arcuate bearing 61 formed on the top surface in the central portion of leg 51 in the longitudinal direction (hereinafter referred to as central top surface 60 ). Semi-arcuate recess 62 , into which first disk 53 is fitted, is formed on leg 51 on the back surface of the central portion in the longitudinal direction.
[0045] Circular hole 64 is formed through the center of first disk 53 through which shaft 52 extends. A large number of teeth 82 ( FIG. 13 ) are formed along the circumferential direction on the back surface of first disk 53 . Fixed pieces 66 , provided with throughholes 65 , are disposed on the front surface of first disk 53 and extend in the axial direction of shaft 52 . First disk 53 is fixed to leg 51 by screws (not shown) which extend through throughholes 65 of fixed piece 66 into screw holes 67 formed on central top surface 60 of leg 51 . First disk 53 is thus integrated with leg 51 .
[0046] Second disk 54 , which has substantially the same shape as first disk 53 , is provided with a large number of teeth 70 on the surface which is opposite to the back surface of first disk 53 . Teeth 70 mesh with teeth 82 formed on the back surface of first disk 53 . Hole 71 is formed on second disk 54 through which shaft 52 is inserted. Hole 71 is not circular but polygonal.
[0047] Shaft 52 does not have a uniform cross section in the axial direction. A portion of shaft 52 that is inserted into hole 64 of first disk 53 has a circular cross section, similar to hole 64 , and a portion that is inserted into hole 71 of second disk 54 has a polygonal cross section, similar to hole 71 . Therefore, shaft 52 can rotate about the axis independently of first disk 53 , but cannot rotate independently of second disk 54 . It means that when either shaft 52 or second disk 54 rotates, the other ( 52 or 54 ) also rotates in the same direction. However, second disk 54 can be independently displaced in the axial direction of shaft 52 .
[0048] One end of shaft 52 extends through second disk 54 , annular resilient member 55 , and spacer 56 . Bracket 58 is fixed to the end. Specifically, as illustrated in FIG. 12 , resilient member 55 and spacer 56 are sandwiched between the back surface of second disk 54 and bracket 58 , such that second disk 54 is usually pressed against first disk 53 by the resilient force of resilient member 55 . The other end of shaft 52 extends through first disk 53 , and is supported from below by bearing 61 formed on central top surface 60 of leg 51 . Bracket 57 is fixed to the end.
[0049] Referring again to FIG. 11 , positioning member 59 is fastened to central top surface 60 of leg 51 by common screws (not shown) which also fix fixed pieces 66 of first disk 53 to central top surface 60 of leg 51 . Protrusion 80 which is substantially triangular in shape is formed at the center of positioning member 59 by having it pressed into this shape. Positioning member 59 and bracket 57 are positioned such that protrusion 80 of positioning member 59 fits in a groove (not shown) formed in bracket 57 only when bracket 57 is parallel with leg 51 .
[0050] The tilt angle adjusting device having the above-mentioned structure is fixed to the housing of a projector (not shown) by screws (not shown) which extend through screw holes 81 formed in brackets 57 , 58 arranged on both ends of shaft 52 , and which extends into the back surface of the housing of the projector. Therefore, the housing is coupled with leg 51 pivottaly about shaft 52 which serves as an axis of rotation. As a result, similar to the embodiment illustrated in FIG. 7 , as force is applied downward at one of the sides of the top surface of the housing in a width direction (longitudinal direction of leg 51 ), rotation moment is caused about shaft 52 . Assume that the force applied to the housing is F 10 , the force with which resilient member 55 presses second disk 54 against first disk 53 is F 11 , and the combined force acting on the surface of teeth 57 of second disk 54 that engages with teeth 82 of first disk 53 is F 12 . The relationship between these forces is illustrated in FIG. 13 . Thus, as F 12 becomes larger than F 11 , second disk 54 is displaced in the axial direction of shaft 52 (to the left in FIG. 12 ) against the resilient force of resilient member 55 . Teeth 57 of second disk 54 is released from engagement with teeth 82 of first disk 53 , to cause second disk 54 and shaft 52 to rotate by an angle corresponding to one tooth. As a result, the housing also pivots by an angle corresponding to one tooth in the direction in which the rotation moment is caused. In the foregoing manner, tilt angle adjusting device 50 can rotate the housing to the left or to the right to adjust the image angle in a stepwise manner.
[0051] Further, when bracket 57 is positioned parallel with leg 51 while the housing of the projector is rotated to the left or to the right, protrusion 80 of positioning member 59 fits into the groove of bracket 57 . This fitting motion produces a clicking sound and tactile feedback to the hand of an operator who is applying force to the housing. As such, the operator can easily and securely know the horizontal orientation of the housing. The force required to disengage protrusion 80 of positioning member 59 fitted in the groove of bracket 57 from that groove may be smaller than the force required to release the engagement of teeth 82 of first disk 53 from teeth 57 of second disk 54 .
[0052] Additionally, a stopper may be provided between the surface of first disk 53 and recess 62 into which first disk 53 is fitted, in order to limit displacements of first disk 53 in the axial direction of shaft 52 . Preferably, a notch may be formed in recess 62 in order to avoid interference of the stopper with recess 62 . Further, a stopper may be provided between spacer 56 and bracket 58 , in order to avoid excessive displacements of second disk 54 in the axial direction of shaft 52 .
[0053] While certain preferred embodiments of the present invention have been shown and described in detail, it should be understood that various changes and modifications may be made without departing from the spirit or scope of the appended claims.
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A tilt angle adjusting device has a shaft configured to be fixed to a bottom surface of a housing at at least one end, and a moment transmission member connected to the shaft. The moment transmission member allows relative rotation between the shaft and the moment transmission member when a moment equal to or more than a predetermined value is applied about an axis of the shaft from the housing, and restricts the relative rotation when the moment is released. The moment transmission member includes a leg configured to be placed on a surface on which the housing is installed. The leg is provided with part of a bearing to support the shaft. The moment transmission member also includes a plate member to press an outer peripheral surface of the shaft. The plate member forms the rest of the bearing.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a masonry wall system and, more particularly, to an above ground lentil supported masonry wall having post tensioning elements.
[0003] 2. Description of Related Art
[0004] The use of masonry walls is well known in the prior art. The significant pressures exerted by heaving soil due to freezing and melting of water requires prior art masonry walls to incorporate a significant amount of steel in the form of reinforcing bars extending through the voids or cells in the masonry block and into a foundation or a footer. A variety of other techniques have also been used in the prior art in an attempt to strengthen the wall and to provide sufficient resistance to the pressure caused by the soil pressing against the bottom of the wall; these techniques are usually complicated and are always expensive. Some prior art techniques have incorporated post tensioning rods wherein courses of block have been compressed with respect to each other and the compressed courses are then secured in some manner to a foundation. These latter techniques usually require expensive installation provisions for appropriately supporting the compressed courses on the designated foundation or footing.
SUMMARY OF THE INVENTION
[0005] The present invention incorporates a masonry wall structure that utilizes a foundation or footing for supporting a lentil upon which the courses of masonry block are built. Post tensioning rods are imbedded in concrete within the lentil and extend upwardly essentially vertically from the lentil. A plurality of courses of masonry block are then placed on the lentil with the respective post tensioning rods extending through the cells therein and beyond the next to the top course of the masonry blocks. Clamping plates extend across the cells of selected masonry blocks in the next to the top course of blocks and include an opening therein to permit the passage of the threaded end of a respective post tensioning rod. The end of each of the post tensioning rods receive a nut which is placed on the rod and threaded to engage the clamping plate and a predetermined tension is placed on the respective post tensioning rod. A top course of masonry blocks is laid with the cells therein receiving the threaded rod ends engaging the nuts and the cells are filled with grout. A column or post of H-shaped blocks defining slots on opposed sides and having an internal vertical space extends upwardly from a corresponding foundation or footing. Alternatively, such a post may be constructed of other blocks, bricks, etc. to define the slots and the vertical space. Post tensioning rods extend from within the footing upwardly through the center cells of the H blocks and is secured to the top of the post by a nut bearing against a clamping plate to post tension each post. For cost reasons or other considerations, rebar extending from the footing and grouted within the vertical space may be used in place of the tensioning rods. The lintel and lintel supported wall extend from within the laterally oriented slots in opposing relationship of adjacent posts. If the footing is at ground level, a starter course of masonry or plate is placed thereon to support the lintel above ground and the post extends upwardly therefrom. In an alternate embodiment, each lintel supported wall rests upon the footing or upon a plate on the footing and a post tensioning rod extends from within the footing upwardly through the end of the wall and is secured by a nut and clamping plate.
[0006] A primary object of the present invention is to provide an above ground block or brick wall.
[0007] Another object of the present invention is to provide an above ground lintel for supporting a block or brick wall between adjacent posts.
[0008] Still another object of the present invention is to provide an above ground lintel supported block or brick wall having tensioning rods extending upwardly from within the lintel.
[0009] Yet another object of the present invention is to provide a lintel supported block or brick wall disposed between posts constructed of H blocks and nesting within the opposing slots of adjacent posts that accommodate vertical movement of the lintel supported wall.
[0010] A further object of the present invention is to provide a lintel supported block or brick wall secured to a footing at opposed ends by tension rods extending from within the footing and upwardly through a significant height of the wall.
[0011] A still further object of the present invention is to provide a plurality of lintel supported wall sections each end of which is supported by a footing to locate the lintel above ground.
[0012] A yet further object of the present invention is to provide a method for constructing an above ground block or brick wall supported at the opposed ends by a footing and in slidable engagement with slots disposed in columns extending from the footings.
[0013] A yet further object of the present invention is to provide a method for providing post tensioning rods to anchor a lintel supported block or brick wall above ground.
[0014] A yet further object of the present invention is to provide a lintel supported wall attached to a footing at each opposed end by post tensioning rods.
[0015] These and other objects of the present invention will become apparent to those skilled in the art as the description of the invention proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will be described with greater specificity and clarity with reference to the following drawings, in which:
[0017] FIG. 1 is a perspective view of a lintel supported block or brick wall system;
[0018] FIG. 2 is a cross sectional view taken along lines 2 - 2 , as shown in FIG. 1 ;
[0019] FIG. 3 is a cross sectional view taken along lines 3 - 3 , as shown in FIG. 1 ;
[0020] FIG. 4 is a partial view of the wall and the upper end of a post tensioning rod;
[0021] FIG. 5 illustrates the bottom block of a wall supporting post;
[0022] FIG. 6 illustrates a method for filling the cells in the top course of the wall;
[0023] FIG. 7 illustrates slabs above the cells of the top course of the wall;
[0024] FIG. 8 illustrates the ladder wire between courses of the wall;
[0025] FIG. 9 is a cross sectional view of the concrete filled lintel; and
[0026] FIG. 10 illustrates a variant structure for supporting the end of a block or brick wall on a footing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring to FIG. 1 , there is illustrated an above ground block or brick wall system 10 . The wall system or structure provides walls supported by post assemblies 12 at each end of each wall section, which post assemblies support bottom edge 14 of wall 16 above ground at a predetermined height. Such above ground support accommodates heaving of the ground due to freezing, melting permafrost, flooding and other phenomena that may occur. Moreover, the growth of roots of trees planted close to wall 16 will have little, if any, tendency to raise and crack a section of the wall.
[0028] Below ground foundations or footings 20 , 22 support plates 24 , 26 upon which posts 28 , 30 , respectively, are built. Preferably, these posts are of blocks known as H blocks and are commercially available from various sources. The posts also may be columns built in the conventional manner to provide vertical slots on opposed sides and a vertical space extending therethrough. A lintel 32 is supported by plates 24 , 26 and nests within vertical slots 52 , 54 formed in each of posts 28 , 30 . A plurality of courses of blocks are built upon the lintel and also extend into the slots of the posts. As illustrated, wall 16 may include post tensioning rods to greatly enhance the structural strength of the wall.
[0029] Referring jointly to FIGS. 2 and 5 , details of post 28 will be described. As footing 20 is poured into a pre-excavated hole 34 in ground 36 , lower ends 38 of a pair of tensioning rods 40 are placed therein to extend upwardly essentially vertically. After curing of footing 20 , apertured plate 24 is placed thereupon with tensioning rods 40 extending through the aperture; plates of this type are commercially available; these plates may also be referred to as a starter course of masonry blocks. Thereafter, a plurality of commercially available H blocks 42 are laid in the conventional manner to form post 28 . The center cell of the H block is filled with grout to encapsulate tensioning rods 40 except for the threaded upper ends thereof extending above the next to the top H block. A clamping plate or plates 44 is brought into penetrable engagement with threaded ends 46 of the tensioning rods and nuts 48 are brought into threaded engagement with the ends to bear against the clamping plate and thereby place tensioning rods 40 in tension to greatly enhance the strength and robustness of posts 28 / 30 . A top H block 50 is laid and the center cell may be filled in the conventional manner. As particularly shown in FIG. 5 , posts 28 / 30 define a pair of opposed vertically extending slots 52 , 54 . For cost and/or engineering considerations, conventional rebars or rods extending from within the footing into the posts and grouted may be used in place of the tensioning rods.
[0030] Referring jointly to FIGS. 3, 4 , 5 and 9 , the structure and construction of wall 16 will be described. Lintel 32 is known in the trade as a galvanized box lintel; a particularly suitable version is sold by Power Steel and Wire, Inc. This lintel is, in cross section, like the letter C lying on its back with the ends folded back upon themselves, as illustrated in FIGS. 3 and 9 . After the lintel is placed upon plates 24 , 26 of posts 28 , 30 within slots 52 , 54 (see FIG. 1 ), lower ends 58 of tensioning rods 60 are placed within the lintel. Ends 58 of the tensioning rods may be bent back upon themselves, as illustrated, to receive one or more longitudinally extending rebars 62 . Thereafter, lintel 32 is filled with grout in the conventional manner to encapsulate ends 58 of the tensioning rods and any rebars 62 placed therein. During curing of the grout, the tensioning rods are maintained essentially vertical. Furthermore, the longitudinal placing of the tensioning rods along the lintel is dimensioned to coincide with the voids or cells in the blocks forming the courses of wall 16 . After curing of grout 64 within lintel 32 , courses of concrete masonry units (CMU) are laid in the conventional manner. Each of the courses extends into slots 52 , 54 of posts 28 , 30 . After all but the top course of CMU's or blocks 66 have been laid, a clamping plate 70 is laid thereon in penetrable engagement with threaded end 72 of each tensioning rod 60 . Thereafter, a nut 74 is threadedly engaged with the end and bears against the clamping plate to bring the tensioning rod into tension. Top course 76 is then laid in the conventional manner. Cells 78 therein may be covered by a plurality of plates 80 , as shown in FIG. 7 . Alternatively, paper 82 may be placed within each cell not having a plate associated therewith to serve in the manner of a dam, as shown in FIG. 6 , and grout 84 is placed thereabove and even with the top of top course 76 . Other conventional methods for closing any open cells may be employed. As illustrated in FIG. 8 , a wire ladder 86 may be placed on top of each course, as is conventional to further add to the robustness and structural strength of wall 16 . Bricks of conventional material which have passageways extending therethrough are commercially available; it is to be understood that such bricks could be used in place of the CMU's for each course or for certain of the courses. Blocks of other materials, including man made materials, meeting engineering and cost constraints could also be used.
[0031] Referring to FIG. 10 there is illustrated an alternate wall system 100 embodying wall 16 and supporting same. Footings 20 are poured in the conventional manner. Before the footings set, tensioning rods 102 , 104 , spaced apart from one another, are set and extend vertically upwardly. After the footings cure, a starter course of masonry block(s) or plates 106 are mounted thereon with the tensioning rods extending through passageways therein.
[0032] Wall 16 is built as set forth above. That is, lintel 32 is laid upon plates 106 and tensioning rods 60 set in grout therein and extend upwardly therefrom. Furthermore, tensioning rods 102 , 104 extend through the aperture or opening in the lintel. Thereafter, blocks 66 are laid in the conventional manner with tension rods 60 and 102 , 104 extending therethrough. Each of these tensioning rods is anchored by a clamping plate in penetrable engagement with the respective threaded end 110 . A nut 112 is brought into threaded engagement with each threaded end for placing the respective tensioning rod in tension. Top course 76 is added in the conventional manner.
[0033] By inspection of FIG. 10 , it will be evident that posts 28 , 30 illustrated in FIG. 1 are not used. Instead, tensioning rods 102 , 104 serve the purpose of anchoring each end of wall 16 to its respective footing 20 . Furthermore, plates 106 maintain lintel 32 above ground.
[0034] By using both tensioning rods 60 within wall 60 and tensioning rods 102 , 104 at the respective ends of the wall, the wall is maintained in significant compression. Such compression adds very measurably to the structural rigidity and robustness of the wall. Furthermore, tensioning rods 102 , 104 are a significant factor to resist tilting of the wall due to externally imposed forces. As tensioning rods 102 , 104 serve the function of posts 28 , 30 (see FIG. 1 ), they permit elimination of the material and labor costs attendant such posts for a considerable overall savings in the building of wall structure or system 100 .
[0035] Where the strength resulting from use of tensioning rods is not necessary, rebars or like rods could be used as substitutes for the tensioning rods in the embodiments described above.
[0036] The robustness of wall 60 has a further subtle, but important attribute. When the ground heaves to an extent sufficient to contact the underside of lintel 32 , forces are imposed on the lintel and the wall extending upwardly therefrom. These forces may be sufficient to stress the wall sufficiently to compromise its integrity unless the stresses are relieved. As is evident from the above description, wall 60 is located with opposed slots of the posts but it is not mechanically attached to the slots. Accordingly, the wall can rise within the slots in the posts at opposed ends upon an application of a lifting force on the lintel. Thereby, the stresses due to heaving of the ground sufficient to contact the lintel can and are relieved by a resulting upward sliding of the wall and the integrity of the wall structure will not be compromised.
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A wall system or structure includes a lintel supported wall and footings for locating the lintel above ground. Tensioning rods extend upwardly from each footing for directly engaging an end of the wall or for securing a post to the footing, which post includes a slot for engaging the vertical edge of the wall. A plate resting on each footing may be used to support an end of the lintel above ground. Tensioning rods extend vertically from within the lintel upwardly into the wall.
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FIELD OF THE INVENTION
The present invention relates to an improvement in hardwood-based laminated wood flooring used in truck trailers and containers. A novel joint design and a new assembly technique are used together with usual techniques of wood laminating in the production of truck trailers floors. The application of this technique improves the mechanical properties, the protection against humidity and the fatigue resistance.
DESCRIPTION OF THE PRIOR ART
Conventional wood flooring for over-the-road truck trailers and containers is normally manufactured with hardwoods such as oak, maple, birch, beech, etc. The green lumber used as a starting material in such manufacture is suitably dried in special drying chambers under controlled conditions. The dried lumber is then sawed into strips of rectangular cross-section and defective portions are eliminated by cross cutting the strips. After, with a double end matching or during the cross cutting process, <<hooks>> are formed at the ends of the lumber strips. The relatively defect-free lumber strips are coated on their vertical sides or edges with an adhesive such as urea-melamine formaldehyde or polyvinyl acetate. The uncured edge-glue lumber strips are then assembled by hand on a conveyor by placing them side-by-side and one in front of other strips, which were previously assembled. Applying heat and edge pressure to large sections of the assembled lumber strips cures the adhesive thus forming a unitary panel. Other means of curing the adhesive are also known.
The joints are a simple mechanical coupling between the mating hook ends of opposing lumber strips without significant adhesive bonding at the joint itself. The <<hook joint>> (see FIG. 1 , identified as prior art) is necessary in the present manufacturing process because it links every strip the one in front and behind, the one at the front pulling on the back (FIG. 2 ). In this respect, the hook joint helps pull the strips through the manufacturing process, and is not structural. Often, due to imperfect assembly ( FIG. 3 ) or because the hook breaks easily ( FIGS. 4 a and 4 b ), a readily visible gap is formed at the hook joint, which can be seen from the top and bottom surfaces of the finished laminated wood floor ( FIGS. 5 a and 5 b ). These opened joints, which can traverse the floor entirely, must be repaired, usually with putty. However, this repair does not obviate the risk of water leaking through.
The manual assembly of the strips is a very important element and is essential to reach the desired mechanical properties of the floor and meet industrial requirements. In fact, the persons that assemble the strips must 1) minimise the number of joints by square foot and 2) maximise the space between joints in a way that it is equalised all over the wood surface ( FIGS. 6 a and 6 b ). These two elements maximise the floor's mechanical support and the durability.
At the output of the press, the cured laminated wood is cut to a desired length (up to about 60 feet) and width (about 6 to 18 inches) to form boards. The boards are then planed to a desired thickness and shiplaps and crusher beads are machined on the sides. A shiplap is a rectangular projecting ledge along the length on each side of a floorboard. The crusher bead is a small semi-circular projection running along the length on each side of a board and placed over or below a lip (FIG. 7 ). When the floorboards are assembled in a trailer such that the side edges of corresponding boards are squeezed together, the shiplaps of adjacent boards overlap to form a seam. The crusher beads provide spacing between adjacent boards and help in preventing buckling of the boards due to expansion of the board following absorption of water. Wood putty is applied at the hook joints on the top and bottom surfaces of the boards to fill any gaps. Finally, the underside of the floorboards is coated with a polymeric substance termed as “undercoating” to provide moisture protection. The finished floorboards are assembled into a kit of about eight boards for installation in a trailer. Normally, a kit consists of two boards with special shiplaps so that they will fit along the road and curb sides of a trailer. The other boards may be identical in design and they are placed between the road and curb sideboards. In some trailers, a metallic component such as a hat-channel may be placed between any two adjacent boards. The metallic component becomes part of the floor area. The boards adjacent the hat-channel have machined edges designed to mate with the flanges of the metallic component. All the boards are supported by thin-walled cross-members of I, C or hat sections, each having an upper flange or surface, which span the width of the trailer and are spaced along the length of the trailer. Each floorboard is secured to the crossmembers by screws or other appropriate fastener extending through the thickness of the board and the upper flanges of the cross-members.
Hardwood-based laminated wood flooring is popularly used in truck trailers since it offers many advantages. The surface characteristics of hardwoods such as high wear resistance and slip resistance are most desirable. The strength and stiffness of the flooring is important for efficient and safe transfer of the applied loads to the cross-members of the trailer. The shock resistance of wood is useful to withstand any sudden dropping of heavy cargo on the floor. Nail holding capability and the ability to absorb small amounts of water, oil or grease without significantly affecting slip resistance are yet additional favourable properties of hardwood flooring.
Although the conventional wood flooring has many desirable features, it also suffers from certain disadvantages. One of the problems is the hook joint at the end of each stick. The design of the hook joint is not optimal for a trailer floor for two principal reasons.
Firstly, water from the road is known to leak into trailers through the hook joints. The reasons the water can leak into the joint are that during the production of the floor, there is not enough longitudinal pressure to ensure that all the hook joints are tightly closed. This lack of pressure sometimes creates small gaps which can extend through the floor, allowing water to leak into the trailer. Furthermore, during the assembling of the strips of wood, the assembler may not assemble the sticks properly, breaking the hook or leaving a gap between two strips through which water can penetrate. Finally, the design of the hook joint is not optimal to properly prevent water from entering by capillarity into the joint. Although the undercoating is supposed to provide a barrier to the path of water, it may not properly cover larger gaps, thus exposing them to moisture. Wetting and drying cycles can degrade the undercoating leading to its cracking and peeling away from the wood. Over time, the action of the shrinkage and the swelling at the end of the strip will create the start of a failure in the line of glue along the glue line between strips. Over the time, the floor will lose is initial strength and stiffness, gradually reducing its integrity.
Secondly, each hook joint in a trailer floor is mechanically a weak spot due to the shape of the hook. This reduces the capacity of the floor to react properly to the dynamic action of a moving lift truck placing heavy cargo into the trailer. A lift truck is often used on the trailer floor to load and unload cargo. A large amount of the weight of the lift truck and the cargo is transferred to the flooring through the wheels of the front axle of the lift truck due to the momentary raising of the rear axle when the lift truck is dynamically placing a heavy cargo on the floor. The dynamic action of a moving lift truck placing heavy cargo on the trailer floor creates severe stress concentration in the flooring and some of the cross-members. Bending of the floor between two adjacent cross-members due to any applied load on the top of the floor has a tendency to open the hook joints and enlarge the gaps. Additionally, because of the design of the hook joint, the capacity of the load transfer is optimal only in one direction of the floor, not the other direction. The effect of repeated lift truck operation on the conventional wood floor causes considerable fatigue damage including: delamination of the edge glued lumber strips near the hook joints leading to the “pop-out” of the lumber strips on the underside; crack initiation and propagation in the wood strips on the underside of the floor due to tensile stresses; and cracking of edge glue lines due to shearing, transverse bending and twisting of the floor. The combination of moisture attack and fatigue damage to the wood floor affects its performance thus necessitating its repair or replacement. In some cases, catastrophic structural failure of the trailer floor system may occur leading to the unacceptable injury to working personnel and damage to machinery.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and apparatus for making a floorboard, and a resulting floorboard, which improves the mechanical properties, the protection against humidity and the fatigue resistance of a floorboard.
In accordance with the invention, these and other objects are achieved with a floorboard comprising a plurality of elongated wood strips of unequal lengths assembled end to end and side by side, each side being coated with an adhesive, said wood strips being cured together to form said floorboard, each wood strip having two opposite ends, each opposite end being provided with spaced apart fingers so that when two strips of wood are joined end to end, the fingers of a wood strip engage with the fingers of another wood strip.
In another aspect, the invention concerns an apparatus for making a floorboard comprising:
a conveyor belt; an assembly area located at a first portion on the conveyor belt for receiving elongated strips of wood and for assembling said strips of wood end to end and side by side in rows to form a floorboard, said wood strips being longitudinally interconnected with each other with a finger joint; a press located at a second portion on the conveyor belt, downstream from said assembly area, for receiving said floorboard, said press being provided with lateral pressure means for exerting lateral pressure on said floorboard and a plate movable between a retracted position and a pressing position and with a stop for stopping a leading end of the floorboard; holding means; means for applying longitudinal pressure on said wood strips when said floorboard is in said press; an output area located at a third portion on the conveyor belt, downstream from said curing area, for receiving said cured floorboard said output area being provided with a holder for holding a portion of said floorboard extending beyond said press; and a controller for controlling operation of said apparatus.
In a preferred embodiment of the invention, said means for applying longitudinal pressure are a multi-finger joint pressing machine located at the entrance of the curing area, said multi-finger joint pressing machine including a transversal support bar being movable between a retracted position and an operative position, said support bar being provided with a plurality of fingers extending under the support bar and longitudinally towards the output area, whereby when said support bar is in said retracted position, said floorboard can be conveyed into said curing area, and when said support bar is in said operative position, said fingers engage a top portion of said floorboard in order to apply downward and longitudinal pressure to said wood strips and thereby force said finger joints to close.
The invention also concerns a method for making a floorboard.
DESCRIPTION OF THE FIGURES
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
The present invention will be better understood from reading a description of a preferred embodiment thereof made in reference to the following drawings in which:
FIG. 1 , identified as Prior Art, is a photograph showing a hook joint used in the hardwood trailer floor industry;
FIG. 2 , identified as Prior Art, is a photograph showing wood strips on the conveyor at the entry of the press;
FIG. 3 , identified as Prior Art, is a photograph showing an example of an imperfect assembly at the entry of the press;
FIGS. 4 a and 4 b , identified as Prior Art, are photographs showing broken hook joints;
FIGS. 5 a and 5 b , identified as Prior Art, are photographs showing gaps between two strips of wood;
FIGS. 6 a and 6 b , identified as Prior Art, are photographs showing an assembled truck trailer floor before it goes into the press;
FIG. 7 is a photograph of a shiplap of a trailer or container floor;
FIG. 8 is a photograph showing the new joint (top) and an example of one of the finger joints used by the moulding or furniture industry (bottom);
FIG. 9 is a photograph showing a side view of a shiplap in a board made according to the prior art (top) and the present invention (bottom);
FIGS. 10 a , 10 b , 10 c and 10 d are schematic representations of a press according to the present invention, where FIG. 10 a is a rear perspective view; FIG. 10 b is a top view of the input of the press; FIG. 10 c is a partial front perspective view; and FIG. 10 d is a front elevational view;
FIGS. 11 a and 11 b are partial views of the multi-finger joint pressing machine according to a preferred embodiment of the invention showing the holders and the teeth;
FIG. 12 is a partial side view taken along line 12 — 12 of the fingers of the multi-finger joint pressing machine of FIG. 11 ; and
FIGS. 13 a , 13 b and 13 c are, respectively, schematic representations of the multi-finger joint pressing machine shown in 13 a in the retracted position, and in 13 b and 13 c in the operative position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
To alleviate the above-mentioned problems, a novel joint and a new production equipment and method was designed, tested and refined to improve over conventional wood flooring. The new wood flooring is essentially the same as that of the conventional wood flooring except for the design of the joint, and the equipment used to produce it. The new joint, designated as a finger joint, is highly resistant to the passage of water, seals the bottom of the wood member and solves the problem of leaky hook joints. Also, the finger joint improves the mechanical properties of the flooring and therefore the thickness of the laminated wood can be reduced. Thus, thinner and lighter wood flooring can be produced with equivalent strength when compared to thicker conventional wood flooring. Since the finger joint provides a dramatic diminution of the “pop-out” of lumber strips, the fatigue resistance of the wood flooring can be improved over that of the conventional wood flooring.
Initially, in other wood industries, finger joint technology was developed to reduce the loss of the wood and increase the length of a piece of wood. Over the years, the value of the wood increased and longer and wider boards were becoming rarer every day. It thus became necessary for the wood industry to use the finger joint to maximise the use of the wood. Essentially, finger joint technology permits the use of short pieces of wood to transform them into a long piece of wood. In other words, finger jointing produces a piece of wood which has essentially the properties or characteristics of a piece of clear un-jointed wood. All the equipment developed until now had as its purpose the ability to make a finger joint on both ends of short pieces of wood, put glue into the finger joint, bring the pieces behind each other into a conveyor, apply pressure to press one piece into the next one tightly and cut at the desired length. Depending on the glue used, the strip stayed pressed until the glue reaches its full strength. The longer strip was finally planed or used in its final application.
Actual techniques and jointing equipment are designed to manufacture only one strip at a time. This joint technique cannot be used for manufacturing truck trailer and container floors. In fact, the control of the distance between joints and quantity of joints per square foot is essential in the truck trailer floor manufacturing industry. The manufacture of one strip length at a time and then proceeding to assemble them into a press will randomize the distance and the distribution of the joints on the floor, with no control over the distribution of the joints and the distance between the joints. The only way to control the distance and distribution of the joints is to first proceed with the panel's assembly and then, simultaneously, to the jointing of all strips. The present invention addresses this issue and has required the development of the design of the joints and also the development of new equipment, which permits the simultaneous multiple jointing of a board.
Joint
The prior art joint, shown in FIG. 1 , has a <<hook>> form. As mentioned hereinabove, the joint's form is strictly for facilitating the manufacturing of a floor and reducing production costs. The truck trailer and container industry is using this hook joint for this feature, i.e. “pulling” at the strips together. The hook joint is not ideal for maximising the strength and the durability of the floor.
The new design in finger joint according to the present invention optimises the properties of a trailer's floor. The design of the finger joint is not like other finger joint normally used in the finger joint industry (bottom of FIG. 8 ). The finger was developed according to the particularity of the production process of the trailer floor and the trailer floor itself. The fingers of the joint for the trailer floor are shorter and thicker (top of FIG. 8 ). Since the pieces of wood are assembled by hand, bigger fingers are necessary to ease the connection of a piece of wood behind another. In fact, the angle of those fingers are as important as the size of the finger. The design also takes into consideration the fact that a complete finger (tongue and groove) needs to be in the ship lap. This will make the ship lap ledge stronger and more efficient to prevent the water from introducing itself (FIG. 9 ). Bigger fingers strengthen the finger to reduce breakage when the pieces are assembled. Finally, the fingers are preferably deep enough to optimize the mechanical strength of the joint and at the same time not too deep to increase the loss of the raw material. In a preferred embodiment of the invention, the fingers have a length between 0.15 and 1.5 inches, and the ratio of the base to the end of the finger is preferably greater than 1.8. This ensures that the fingers are wide and long enough to facilitate assembly.
In a typical plant, the manufacturing of the joint is made at the jointer, at the same place where the hook joint is presently manufactured. The jointer is modified to allow the production of the finger joint. Depending on the desired strength of the fingers, glue can be applied between them. The glue will enhance the structural force of the floor. The application of glue into the finger joint will increase the strength of the floor but, so it is not necessary, but optional.
Process and Manufacturing Equipment
Glue is applied on one or both sides of the piece of wood once jointed. They are then jointed by hand side-to-side in rows and one behind another on a conveyor 3 at an assembly area 10 . In general, an assembled panel has 48 to 65 individual strips wide, each being 0.5 inch to 1.5 inches wide and generally at least 6 inches long. It will be understood that other sizes fall within the scope of the present invention. At this point, the assemblers control the distance between joints and their distribution. Once one section is assembled, it is moved forward into the press 20 ( FIGS. 10 a, 10 b, 10 c and 10 d ). At this point, joints have a tendency to open because the strips are not provided with a hook joint at their ends. Inside the press, a device termed multi-finger joint pressing machine 30 closes the joints by applying an individual longitudinal pressure of more than 100 pounds on each strip. This process is called the multiple simultaneous jointing. It is multiple because there is more than one strip and simultaneous because a longitudinal pressure is applied to all strips at the same time. The multiple simultaneous jointing starts as soon as the panel is completely inside the press (see FIGS. 10 a, 13 a, 13 b and 13 c ).
It should be noted at the outset that the length of a completed floorboard is generally longer than the length of the press.
Thus, the assemblers first assemble the leading portion of the floorboard. Once assembled, the leading portion is conveyed into the press into a curing area 57 . Inside the press, there is a stopper 21 , which acts to stop only the leading edge of the floorboard from moving downstream. Once the leading portion has been assembled and cured and the leading portion moves beyond the press into a receiving area 50 , a holding system 40 , sandwiches the floorboard to prevent any longitudinal movement. This holding system is preferably a plate 51 moveable between a refracted position and an operative position.
At the front of the press, either when curing the leading portion of the floorboard, or when curing other portions of the floorboard, the device 30 goes down on the panel's surface in a way that teeth plunge onto each strip of the panel 5 . The joint pressing machinery has a rod or shaft 33 which is horizontally and vertically movable. The rod 33 holds holders 35 , which are preferably laterally movable (see FIG. 11 a ). The holders 35 each support at least one tooth 31 . The tooth is, in a preferred embodiment, a thin rectangular plate, having at least one pick 37 , but preferably more, on its bottom edge (see FIG. 12 ). The holder preferably has an L-shape, and the front portion extending downwardly is provided with a longitudinal hole or slot 55 . The tooth 31 has a forwardly extending shall 39 which is partially inserted into the hole. Between the holder 35 and the tooth 31 and about the shaft 39 , an energy absorber in the form of a spring 41 is placed. The energy absorber, as better shown in FIG. 13 c, acts to absorb excess pressure so as not to damage the floorboard 5 when pressure is longitudinally applied.
It should be noted that the above description of the joint pressing machine 30 is preferential, and that variations in the materials, construction, components, etc. fall within the scope of the invention. What is important is a device, or means, which applies individual pressure to each of the strips during the curing process to close the joints properly. (To ensure good pressure and to be sure that all open joints will close, there is preferably at least one metal tooth for each strip composing the panel. Because the strips do not have always the same width and will not be at the same place in the conveyor, it is preferable for the holder to be laterally moveable to ensure that each tooth is aligned with the middle of each strip. This is important to ensure a good grip and reduce the quantity of glue. It should be noted that other solutions were tried to apply pressure, such as using rubber fingers, rubber teeth or other systems, but metal teeth were found to be the most efficient way to ensure good grip and pressure.)
Once the purchase on each strip is secured, the multi-finger jointing machine moves toward the back of the press and thereby applies an individual longitudinal and downward pressure on each strip.
The pressure will force the strips to nest one with another, closing the finger joints very tightly. (Each metal strip is preferably provided with a pressure absorber, such as a spring or piece of rubber, or any other pressure absorber. When all the joints are closed, the spring will start to contract. This is necessary to prevent the metal picks from scratching the surface of the strip. See FIGS. 13 a , 13 b and 13 c ).
Once this process is over, the press 20 begins the glue's baking or curing process. In the press, a large plate 59 is lowered on the floorboard, and a lateral pressure system applies lateral pressure to downwardly and laterally apply pressure. This type of press is known in the art, and therefore specific details of its construction are not shown. A heater 63 is also provided in the press for triggering the curing process with the use of heat.
The pressure is released when the curing process is over or just after the pressure was applied; the multi-finger jointing machine is moved to the retracted position, and the holding system re-opens (either the stop inside the press or the holding system outside the press).
The curing being over, the press 20 opens and the conveyor 3 exits the cured panel and brings into the press 20 the next portion of the panel to be cured and the process starts over.
It is also understood by persons skilled in the art that an appropriate controller 61 controls the apparatus of the press, the multi-finger jointing machine 30 and the conveyor. It will also be apparent to a person skilled in the art that the specific construction of the holder 40 is not an essential element of the present invention. Furthermore, the components which move the multi-finger jointing machine from its retracted position to its operative position, although preferably being pistons appropriately placed, could be other known or unknown systems, as will be apparent to those skilled in the art. Also, although the motion of the transversal bar is illustrated as following an “L” shape, such motions could be different provided that the pressure is applied downwardly and longitudinally to close the joints, but does not promote buckling of the floor.
Preliminary Test Results
Several production tests were done with the new equipment and the new joint. Results have met expectations.
First, the new the new multi-finger joint pressing machine closes the joint better. Previous floors had only 35% to 50% of the joints closed tightly. With the new multi-finger joint pressing machine, 90% to 100% of the joint are closed tightly, reducing dramatically the quantity of the putty used to fill the gaps.
Second, fatigue tests were performed to see if the floor had a better capacity to spread the load and thus, was stronger than a floor using a hook joint. Again, results have met expectations. In fact, a fatigue test was performed with a load of 13 000 pounds. Usually, a floor with hook joint will reach between 15 000 to 17 000 cycles before failing. A floor with the joint of the present invention was tested. After 20 000 cycles the floor did fail. Another test was done with 16 000 pound loading. Usually a floor with a hook joint will reach between 4 500 to 6 200 cycles before failing. A floor with the joint of the present invention was tested. The floor failed after 9 200 cycles. It is approximately a 50% increase comparatively to a conventional floor using hook joint. These tests show that the new joint, process and equipment increase the strength of the floor and its moisture resistance.
Although the present invention has been explained hereinabove by way of a preferred embodiment thereof, it should be pointed out that any modifications to this preferred embodiment within the scope of the appended claims is not deemed to alter or change the nature and scope of the present invention.
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An apparatus and method for simultaneously pressing together longitudinally a plurality of individual strips of wood, each strip being provided with a finger joint at each end. The strips are jointed end to end in a number of rows to form a floorboard. The apparatus includes a mechanism for simultaneously applying longitudinal pressure to each of the rows of wood strips during the curing process. The resulting floorboard is mechanically improved, has greater protection against humidity and increases the fatigue resistance of the floorboard, which can be used for trailer floors or the like.
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BACKGROUND OF THE INVENTION
A prior-art vehicle suspension system that absorbs shocks adaptively in response to changing conditions is known, for example, from "ESAC--Electronically Controlled Traveling Gear Shock Absorption," which is WABCO Publication 826 001 173 3/8.94 published by WABCO Westinghouse Vehicle Brakes, WABCO Standard GmbH.
The prior-art ESAC suspension system selects a shock-absorption characteristic (soft, medium, or hard) that is most suitable for the current driving condition. In undisturbed travel, for example, the system provides soft, purely comfort-oriented shock absorption. If the vehicle should veer in response to a sudden steering action, on the other hand, the system switches to harder, and therefore safer, shock absorption. Shock absorption also hardens when unevenness in the road surface causes excessive deflections in the suspension system. Adaptive variation of shock absorption is also especially helpful in reducing pitching motions in vehicles that have a short wheel base. During acceleration, the front-end of the bodies of such vehicles otherwise tend to rise up excessively while transferring weight onto the rear axle. During braking, the opposite motion occurs as the rear of the body rises and weight is transferred to the front axle.
The prior-art ESAC suspension system recognizes deflections in the suspension at three points. One sensor detects an average spring excursion at the front axle and two more sensors are placed at the left and right rear springs. These three points are sufficient to determine the plane of the body of the vehicle. The three spring excursions also determine what is called a body shock-absorption requirement.
As mentioned above, the shock absorbers are hardened in case of excessive motions of the body of the vehicle. In other words, the degree of uncoupling is reduced between the axles and body of the vehicle. In this condition, shocks pass from the axles through the suspension to the body with less filtering causing a reduction in comfort. Comfort is especially strongly impacted by small irregularities in the road surface when the suspension system has hardened in response to more gradual but larger hollows or mounds in the roadway.
It is therefore an object of the present invention to provide an improved adaptive suspension system that provides greater comfort, when possible, while maximizing travel safety even on poor roads.
It is another object of the present invention to improve the treatment of loaded goods in vehicles traveling on poor roads. Yet another object is to reduce the load on the shock-absorbers themselves as well as on their controls. A further object of the invention is to provide a software implementation that does not require costly additional hardware components.
It is another object of the present invention is to use a bad-road parameter that takes various effects into account without determining them in unnecessary and costly detail. Among these effects are under-damped axle oscillations. In principle, these oscillations could be determined from the high-frequency components of the output signals of sensors that measure deflection at the springs or piston speed at the shock absorbers. In practice, however, these high-frequency components are removed by filtering, and the effect of the under-damped axle oscillations is lost.
It is another object of the present invention to provide the maximum comfort compatible with travel safety by employing shock absorbers with continuously variable shock-absorption force.
It is also an object of the present invention to provide harder shock absorption on poor roads, even when the vehicle body does not experience excessive vertical motions. For example, short-wave unevenness in the road does not cause shock-absorber hardening in the prior-art system. By hardening the shock absorption in such cases, the present invention avoids an under-damped motion called "axle trampling," which is also a significant cause of road wear. Fluctuations in wheel load are also reduced, which improves the steering and propulsion characteristics of the tires, thereby further ensuring travel safety.
SUMMARY OF THE INVENTION
In accordance with the present invention, a vehicle suspension system adapts to varying conditions to provide as much comfort for persons riding in the body of the vehicle as is compatible with safe handling. The body is supported by the suspension system, which in turn is supported by axles on which wheels are mounted that travel on a roadway. The major components of the system are air springs, also referred to as air bags or bellows, variable shock absorbers, and additional components that adjust the springs and control the shock absorbers. In particular, the system includes sensors that determine the distances between the axle and body at each spring and level adjustments that can increase or decrease these distances.
The system also includes an electronic regulator that samples the sensors and controls the level adjustments in order to maintain the distance at each spring at predetermined desired values. The electronic regulator receives a signal that represents the acceleration of the body with respect to a point on one of the axles from a double-differentiation device. The input of the double-differentiation device is connected to the output of one of the level sensors. The electronic regulator uses the outputs of the level sensors and of the double-differentiation device in setting the shock absorbers to the optimized absorption for the prevailing conditions.
The electronic regulator uses the distances determined by the sensors to determine a body shock-absorption requirement. Higher frequencies corresponding to wheel motions that do not affect the body are filtered out of the sensor signals for the determination of the body shock-absorption requirement. The body motions that must be actively controlled are roll, where the vehicle rises on one side and transfers weight to the other side, and pitch, where one end of the vehicle rises and transfers weight to the other end. The body shock-absorption requirement is expressed as a percentage of a maximum shock absorption, and it is determined by combinations of values of roll and pitch organized as a matrix of cases.
The electronic regulator also computes a bad-road parameter and uses it to modify the body shock-absorption requirement. The result is called the total shock-absorption requirement, which can be either higher or lower than the body shock-absorption requirement. Now, it is technically difficult and costly to determine the forces or the piston speeds at the shock absorbers directly. Therefore, the bad-road parameter is computed instead as a weighted sliding average of the acceleration of the body of the vehicle for a fixed period of time. This acceleration is adequately represented by the output of a double-differentiation device that receives its input from one of the level sensors. Typically, the sensor at the rear wheel traveling at the near side of the road is used. The acceleration of the body at this point is obtained periodically and converted into counts.
The bad-road parameter is calculated from a weighted sliding average of absolute magnitudes of body acceleration. The sliding average is performed over a fixed number of successive measurements of body acceleration ending with the most recent measurement. The weights are either 0 or 1, so the values that are used in the sum can be called selected values. Accelerations are selected if they are larger in magnitude than a certain insensitivity band and if they have changed by more than a certain amount from the previous measurement. The bad-road parameter at each time is then expressed as a percentage of the maximum possible sum. Because small accelerations do not contribute to the bad-road parameter, the calculation provides an effect that is equivalent to a type of high-pass filter.
An example of a bad road would be one containing potholes. The inventive system responds to such short-wave unevenness differently in different ranges of body shock-absorption requirement. For example, when the body shock-absorption requirement is low, a severe oscillation known as "axle trampling" may occur on a bad road. Because it is considered dangerous to allow the axles to trample, a higher value of total shock-absorption requirement is calculated even though this reduces comfort to some extent.
In a medium range of body shock-absorption requirement, the vehicle body undergoes substantial motions even on a smooth road. It is therefore necessary to reduce the total shock-absorption requirement on a bad road. Otherwise, strong jolts could be felt as the hardened shock absorbers damp the short-wave motions that are characteristic of a bad road. In addition to causing discomfort, such jolts stress the shock absorbers and can even damage goods that are loaded on the vehicle.
At high levels of body shock-absorption requirement, safety takes precedence over comfort. This means that the body shock-absorption requirement is not necessarily reduced in computing the total shock-absorption requirement for a vehicle traveling on a bad road. Doing so could increase the body motions enough to damage the vehicle structurally. Such damage must be avoided because it is not possible to guarantee that the vehicle can be controlled once damage has occurred. On the other hand, some reduction of the total shock-absorption requirement may be necessary because a high total shock-absorption requirement could produce shock-absorption forces large enough to damage the shock absorbers or their couplings. This second type of change in body shock-absorption requirement increases both safety and comfort, although the vehicle body will oscillate with larger amplitude.
The organization and operation of this invention will be understood from a consideration of detailed descriptions of illustrative embodiments, which follow, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of steps that the inventive suspension system performs to determine a total shock-absorption requirement from a body shock-absorption requirement and a bad-road parameter,
FIG. 2 explains the calculation of the bad-road parameter in FIG. 1 from a sliding weighted average of accelerations of the springs of the inventive suspension system,
FIG. 3a shows a first type of calculation of the total shock-absorption requirement in FIG. 1 that depends on the bad-road parameter in low and medium ranges of the body shock-absorbtion requirement but not in its high range, and
FIG. 3b shows a second type of calculation of the total shock-absorption requirement in FIG. 1 where the reduction is one way in the medium range of body shock absorption and, if reduced, the total shock absorption is fixed in the upper range.
FIG. 4 is a schematic illustration of the inventive suspension system.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 4, the inventive suspension system 100 relates to an air-cushioned vehicle with a body 102 that is supported on axles 104 by air bags or bellows (also referred to as air springs) 106. The quantity of air in each air bag determines the height of the body where it connects to the air bag with respect to the point where the air bag connects to one of the axles.
The air-cushioned vehicle is furthermore equipped with electronic level adjustment. These adjustments are performed by control valves 107 that are installed on the air bags. Each control valve changes the quantity of air in its air bag in response to an electrical adjusting signal from an electronic regulator 112. There are two valves at each air bag. One of these valves allows compressed air to enter the air bag from a compressed-air storage tank 108, and the other valve bleeds air from the air bag to a sink 110. Level sensors 116 are provided that find the actual distances between the vehicle body and the vehicle axles. The electronic regulator 112 compares the actual distances, which are transmitted from the level sensors 116, with desired distances stored in the regulator.
The electronic regulator begins to change the amount of air in the appropriate air bag when the sensed distance deviates from the desired distance. The regulator continues to fill the bag, or bleed air out of it, until the actual distance becomes equal to the distance desired at that air bag. The electronic regulator carries out this level regulation for all of the different air bags in a multiplexed fashion. For example, the electronic regulator may be a digital regulator with a fixed scanning time. In this case, each level sensor is sampled in succession, and a given level sensor is sampled periodically at a frequency equal to the inverse of the scanning time. The distance that a particular level sensor last transmitted to the electronic regulator is compared with the corresponding desired distance while the other sensors are being sampled.
In an embodiment of the invention for a vehicle with two axles, four air bags would be used. They are placed on the right and left sides of both axles near the wheels. (Alternatively, a pair of air bags may be used on each side of the rear axle. Such a pair of physical bags will be treated as one logical air bag for the purpose of this discussion.) Because the reference plane of the vehicle body is defined by three points, three level sensors provide sufficient data for the adjustment of all four air bags. For example, two of these sensors may be located on the rear axle near the left and right wheels, and the third sensor may be located approximately at the center of the front axle.
Electrically controlled shock absorbers 114 that can be set to values in a continuous range of absorbing force are also provided. For example, an individual shock absorber may be placed near each air bag. One end of each shock absorber is connected to the body, and the other end is connected to one of the axles. For a two-axle vehicle, there are a total of four shock absorbers located at the left and right sides of the front and back axles.
The inventive suspension system absorbs two types of motions that may otherwise be transmitted to the body. A wheel shock-absorption requirement arises from high-frequency motions of the wheels. The suspension system is most prone to transmit these motions to the body when the shock absorbers are hardened. A separate body shock-absorption requirement arises from comparatively low-frequency motions of the body. In fact, the body shock-absorption requirement depends only on the position of the body relative to the axles. This position is determined by sensors that measure the excursion of each spring from its neutral position.
These spring excursions are changes in the actual distances between points on the body and corresponding points on the axles. They are therefore simply related to the distances measured by the three level sensors. Thus the outputs of the level sensors serve a second purpose by determining the presence of body motions that must be opposed by the shock absorbers.
The sampled values of the level sensors are passed through a suitable low-pass filter before further processing. This reduces random fluctuations of the measured values from sample to sample that otherwise might interfere with the level regulation. Low-pass filtering also eliminates wheel oscillations so that body motions can be determined. Based on the filtered measured values of the level sensors, i.e. the filtered actual distances, "rolling" and "pitching" motions of the vehicle body are determined in a known manner. For example, the roll angle can be determined from the difference between the outputs of the level sensors at the left and right sides at the rear axle. The pitching angle is based on the difference between the mean distances supplied by the sensors at the front axle and the sensors of the rear axle.
In determining a shock-absorption requirement, the amplitude as well as the frequency of the oscillations to be attenuated play a role. Low-frequency oscillations have priority because they affect both travel stability and riding comfort. The low-frequency body motions that require attenuation are actually determined by the angles and frequencies of rolling and pitching.
FIG. 1 shows three calculation steps needed to determine the total shock-absorption requirement. A first block (1) calculates the shock-absorption requirement for the body of the vehicle (body shock-absorption requirement), and a second block (2) calculates a bad-road parameter. These results are combined in a third block (3) to produce the total shock-absorption requirement. The body motions explained above are transmitted to the input (4) of the first block (1). The first block (1) produces the body shock-absorption requirement as a percentage of a fixed maximum value at an output (5). The input value (6) of the second block (2) consists of a body acceleration (6) that is explained below. The second block (2) produces the bad-road parameter as a percentage of another fixed maximum value at an output (7).
The body shock-absorption requirement and the bad-road parameter are presented as inputs to the third block (3). The total shock-absorption requirement is then determined as a percentage of yet another fixed maximum value at an output (8) of the third block (3).
The determination of the body requirement for shock absorption according to the first block (1) is known. The body motions are evaluated by sorting rolling and pitching into classes by magnitude and forming a matrix of cases. In each case, the combined effects of rolling and pitching are taken into account appropriately. For example, a high level of shock absorption is required by a high magnitude of roll by itself. In such a case, therefore, an additional medium pitching magnitude has practically no effect on the body shock absorption.
The calculated body shock-absorption requirement, from 0 to 100%, represents the hardening of the shock absorption. No shock-absorption hardening is indicated by a value of 0%, and 100% corresponds to the maximum force of shock absorption. In the prior art, this value alone is used by an electronic regulator to control the shock absorbers in the vehicle.
The calculations performed in the second block (2) in FIG. 1 are based on the acceleration of the body with respect to the axles. As shown, this acceleration is provided at an input (6). The acceleration occurs as changes in the spring excursions are reflected at the outputs of the level sensors. The acceleration of the body is linearly related to the second derivatives with respect to time of the filtered values of the level sensors.
In order to determine the body acceleration exactly, the filtered outputs of all three level sensors should actually be used. Their second time derivatives correspond to accelerations of the body at three points with respect to corresponding points on the axles. These three accelerations, in turn, determine a total acceleration value that is valid for the vehicle body as a whole, and this value can be found in an appropriate manner. In practice however, this relatively expensive approach is not necessary. It suffices to estimate the acceleration of the body using the output of only one of the three level sensors. Any of the three sensors would serve, but road unevenness is generally amplified near the side of the road. For these reasons, the output of the level sensor at the right side of the rear axle is connected to the input of a double-differentiation device 118. The acceleration of the body is thus approximated by the acceleration at the right side of the rear axle, which is given at an output of the double-differentiation device.
As mentioned earlier, the bad-road parameter is determined from a sliding weighted average of the body acceleration. The body acceleration itself is estimated through double differentiation of the actual distance measured by the level sensor at the right-rear wheel. According to the sampling principle, a value of the body acceleration is obtained at every sampling moment. This acceleration value is indicated in the form of "counts," i.e. processor counting units in the electronic regulator. FIG. 2 shows, as an example, a time diagram where the body acceleration is entered on the ordinate in terms of counts. The abscissa is the time axis, and time is represented in units of the sampling time by a dimensionless number n. For the sake of clarity, the body acceleration values at different times are associated with different values of n [for the sampling moments]. The example is based on a sampling frequency of 40 Hz, so the time difference between one sampling moment and the next sampling is 25 ms.
To determine the bad-road parameter, body-acceleration values are selected according to a first criterion. According to this criterion, accelerations of absolute magnitude less than or equal to a predetermined minimum receive no weight. In FIG. 2, for example, the minimum acceleration has been set at 3 counts. All positive body accelerations of more than 3 counts and all negative body accelerations of less than -3 counts are used, and all accelerations in the insensibility band between these two values are discarded.
According to a second selection criterion, body-acceleration values are only used when they differ from the previously sampled value by at least a fixed difference in acceleration. In the example of FIG. 2, body accelerations are discarded when they have not changed from the previous value by at least 3 counts.
In the time diagram of FIG. 2, the two criteria for including the body acceleration are met at the times corresponding to n=2, 4, 5, 11, 13, 21. The points for these measured values are encircled in the time diagram to direct attention to them.
The magnitudes of the body accelerations satisfying both selection criteria are added together over a time window of a fixed number of sampling points. The bad-road parameter is then determined from this sum. In the example of FIG. 2, the time interval of the window corresponds to n=20, which means that the window is 20 sampling times long. The time window itself moves or slides to the right by one sampling time for each successive value of body acceleration.
For the sake of clarity, three successive time windows (18, 19, 20) are drawn in FIG. 2. The selected body-acceleration values assigned to these time windows are located in the time diagram above the corresponding time window. The first time window (18) begins at the time corresponding to n=1 and continues to n=20. The second time window (19) runs from n=2 to n=21, and the third time window (20) runs from n=3 to 22. To calculate the bad-road parameter for a given time window, the magnitudes of the body accelerations meeting the two criteria within that window are added up. For the first time window (18) this sum is 26, in the second time window (19) it has increased to 31, and for third time window (20) it has fallen back to 27. The bad-road parameter for a particular time window is then found by normalizing its sum value and expressing it as a percentage. Suppose the sum can be in the range from 0 to 255 and is represented by an 8-bit binary number. Then in the examples of FIG. 2, the bad-road parameters are:
100*26/255=10.2% for the first time window (18),
100*31/255=12.2% for the second time window (19), and
100*27/255=10.6% for third time window (20).
The time diagram of FIG. 2 thus shows an example for a good road condition.
Level sensors with resolution necessary for these calculations and for the other purpose of level regulation are both inexpensive and very robust.
A bad road is one having mainly short-wave unevenness caused, for example, by the presence of potholes. They can cause the vehicle body to oscillate up and down. However, the amplitude of this oscillation may be too low for the level regulation to respond effectively. Now, direct detection of these low-amplitude oscillations is possible in principle. It is ruled out in practice, however, because such sensors are expensive and require careful handling. Thus, it is not practical to determine the nature of the road directly from the actual distances measured by the level sensors.
In the inventive suspension system, the bad-road parameter is calculated from the accelerations of the actual distances. Because small changes in acceleration between sampling points do not contribute, long-wave irregularities in the road surface do not affect the result. On the other hand, short-wave components are more strongly weighted by the calculation. Thus the calculation provides an effect that is equivalent to a type of high-pass filter. The shorter the waves and the larger the amplitude, the more acceleration values are selected within a time window. The number of selected acceleration values as well as their magnitudes affects the weighted average in a particular time window and thereby increases the bad-road parameter at that time.
In case of short-wave unevenness of the road surface, high shock-absorber speeds or high shock-absorbing forces occur. It is technically difficult to detect either of these quantities directly, and a detector for this purpose would be very costly to manufacture.
The process explained above and illustrated in FIG. 2 determines a bad-road parameter from the accelerations of the distances measured by the level sensors. This makes it possible to judge the road condition without measuring shock-absorption forces or the speed of the pistons in the shock absorbers.
As FIG. 1 shows, the body shock-absorption requirement present at the output (5) of the first block (1) and the bad-road parameter present at the output (7) of the second block (2) serve as inputs to the third block (3). In the third block (3), the body shock-absorption requirement is modified by the bad-road parameter. The resulting total shock-absorption requirement is provided by the third block (3) at an output (8). Finally, the electronic system regulator uses the total shock-absorption requirement to set the shock absorbers within a continuous range of shock absorption.
The third block (3) in FIG. 1 uses the bad-road parameter to calculate a correction of the body shock-absorption requirement. It would be ideal to use the shock-absorption force to make this correction. As already mentioned, however, a direct detection of the attenuation force or piston speed is not practical. The bad-road parameter is a satisfactory substitute for the shock-absorption force because large forces appear with large bad-road parameters and low forces appear with low bad-road parameters. That is, a large bad-road parameter indicates that the axles are oscillating with high amplitudes at high frequencies, which leads to large shock-absorption force or high piston speed.
FIG. 3a shows a first type of change of the body shock-absorption requirement for the determination of the total shock-absorption requirement. On the abscissa of FIG. 3a, the body shock-absorption requirement is entered as an independent variable in a range from 0 to 100%. The ordinate shows the calculated total shock-absorption requirement, also within a range of 0 to 100%. Three curves (9, 10, 11) are drawn to show the change of the body shock-absorption requirement depending on the value of the bad-road parameter. The first curve (9) shows that there is no change for a bad-road parameter of 0%. The second curve (10) and the third curve (11) show the changes for a bad-road parameter of 50% and 100%, respectively.
The three curves (9, 10, 11) show an increasing influence upon the body shock-absorption requirement as the bad-road parameter increases. In the first curve (9), the influence is zero. In the second curve (10), a bad-road parameter of 50% has produced a change that is already clear by comparison with the first curve (9). The third curve (11) shows the maximum change for a bad-road parameter of 100%.
The type of change of the body shock-absorption requirement also depends on the magnitude of the body shock-absorption requirement itself. This dependence is accounted for by calculating the change differently in two or more ranges of body shock-absorption requirement. The total shock-absorption requirement can be more finely tuned as the number of ranges increases, but the expense also increases, and consequently a suitable compromise between function and cost must be found. A good compromise is achieved with the three ranges of body shock-absorption requirement selected for FIG. 3a.
For the definition of the ranges, a lower limit value (12) and an upper limit value (13) of body shock-absorption requirement are chosen. A lower range "A" comprises all values of the body shock-absorption requirement smaller than the lower limit value (12). A medium range "B" comprises all values of the body shock-absorption requirement equal to or larger than the lower limit value (12) and smaller than the upper limit value (13). Finally, in the upper range "C" the body shock-absorption requirement is equal to or larger than the upper limit value (13).
In the lower range A, the total shock-absorption requirement increases as the bad-road parameter increases. In this range, a large bad-road parameter indicates short-wave unevenness of the road surface. For example the surface may contain potholes, which do not impart much movement to the vehicle body due to its relatively large mass. However, the axles of the vehicle are underdamped, and this can lead to axle trampling on a bad road. This danger is reduced by the increase in total shock-absorption requirement. This change by itself reduces comfort to some extent, but, on the other hand, it is considered dangerous to allow the axles to trample.
In the medium range B of body shock-absorption requirement, the vehicle body undergoes substantial motions even on a smooth road. It is therefore necessary to reduce the total shock-absorption requirement on a bad road. Otherwise, strong jolts could be felt as the hardened shock absorbers damp the short-wave motions that are characteristic of a bad road. Such jolts can also damage goods that are loaded on the vehicle. Thus both comfort and load security are improved by reducing the total shock-absorption requirement in the medium range. Furthermore, the shock absorbers themselves are stressed less because the shock-absorption task is reduced.
Within the upper range C, the total shock-absorption requirement is not changed from the body shock-absorption requirement. Reducing shock-absorption in this range too much could result in body motions large enough to damage the vehicle structurally. Such damage must be avoided because there is no way to guarantee that the driver could control the vehicle in its altered condition. Thus, because safety has priority, comfort is disregarded in this range.
FIG. 3b shows a second way of modifying the body shock-absorption requirement to determine the total shock-absorption requirement for a vehicle traveling on a bad road. The division into three ranges of body shock-absorption requirement and the effects of a bad road in the low range are the same as shown in FIG. 3a. Furthermore, the total shock absorption for a bad-road parameter of 0% is again equal to the body shock-absorption requirement. For these reasons, the same reference numbers (12) and (13) will be used for the lower- and upper-limit values, respectively, of the medium range of body shock-absorption requirement. Furthermore, the same number (9) will be used to label the total shock-absorption requirement when the bad-road parameter is 0%. The effect of a 50% bad-road parameter is indicated by the middle curve (14), and the lower curve (15) shows the effect of a bad-road parameter of 100%.
In its low range, FIG. 3b changes the body-shock absorption requirement by the same amount as FIG. 3a to account for a bad road. In the medium and upper ranges however, a different type of change is provided in FIG. 3b.
In the medium range in FIG. 3b, the reduction in the shock-absorption requirement is similar to the reduction in FIG. 3a while the body shock-absorption requirement is increasing from the lower limit (12) and the reduction itself is increasing. However, the reduction is maintained as the body shock-absorption requirement approaches the upper limit (13). Thus the 50% bad-road curve (14) ends up at a total shock-absorption requirement (16) that is below the upper curve (9) at the upper limit (13) of the medium range. The lower curve (15) for a bad-road parameter of 100% ends up at an even lower value (17) of total shock-absorption requirement at the upper limit (13) of the medium range of body shock-absorption requirement.
As mentioned above, the reduction of the shock-absorption requirement is maintained in the two curves (14, 15) of FIG. 3b when the upper limit value (13) is approached. For example, the curves for bad-road parameters of 50% and 100% go through points (16) and (17), respectively, at the upper limit value (13). In the upper range C, the total shock-absorption requirement is held constant when the bad-road parameter is non-zero. The constant depends on the bad-road parameter such that the total shock-absorption requirement for each bad-road parameter is continuous at the upper limit (13) of the medium range of body shock-absorption requirement. In FIG. 3b, the values (16) and (17) for bad-road parameters of 50% and 100%, respectively, are clearly below the curve for zero bad-road parameter (9).
The total shock-absorption requirement in FIG. 3b for high values of the body shock-absorption requirement (upper portion of the medium range and entire upper range) is lower than in FIG. 3a. This second type of change is also made to reduce the danger that a vehicle traveling on a bad road may sustain damage and become unsafe. The reduction is desirable because a high total shock-absorption requirement could produce shock-absorption forces large enough to damage the shock absorbers or their couplings. This second type of change in body shock-absorption requirement increases both safety and comfort, although the vehicle body will oscillate with larger amplitude.
The inventive suspension system is most effective at maximizing comfort consistent with safety when the shock absorbers admit a fine-grained or continuous adjustment of shock absorption. Nevertheless, the invention can also be applied advantageously with shock absorbers that have a relatively small number of fixed settings. Even when the shock absorbers have only soft, medium, and hard settings, it is still advantageous to take the bad-road parameter into account. For example, on a smooth road, the soft, medium and hard settings could be chosen when the total shock-absorption requirement is less than 20%, between 20% and 70%, and greater than 70%, respectively. Although the variation in settings is limited, an advantageous influence of the bad-road parameter is especially ensured in the medium and higher ranges of body shock-absorption requirement.
While the invention has been described by reference to specific embodiments, this was for purposes of illustration only. Numerous alternative embodiments will be apparent to those skilled in the art and are considered to be within the scope of the invention.
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A vehicle suspension system that varies its shock absorption maximize comfort when compatible with safe handling. Level sensors are positioned to determine the position and attitude of the body of the vehicle in relation to its axles. An electronic regulator controls adjustable air springs to maintain the desired position and orientation of the body. Each air spring can be filled from a compressed-air supply to raise the body, and the system can also bleed air off to lower the body. The electronic regulator also accepts a signal from a double-differentiation device that is connected to the output of one of the level sensors. This signal is a measure of the acceleration of the body, and it is used to compute a bad-road parameter. The bad-road parameter also depends on the change in acceleration that occurs between successive measurements. The electronic regulator calculates a body-shock absorption requirement from the outputs of the level sensors and then uses the bad-road parameter to compute the total shock absorption required from the variable shock absorbers. On a bad road, when the body shock absorption is low, the total shock absorption is increased to provide better handling. When the body shock-absorption requirement is medium, the total shock absorption is lowered on a bad road to increase comfort or safety of loaded goods. When the body shock-absorption requirement is high, safe handling takes precedence over comfort on a bad road, but the total shock absorption may need to be lowered to avoid damaging the suspension system.
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BACKGROUND OF THE INVENTION
Oxygen separators such as disclosed in U.S. Pat. No. 3,880,616, separate fluid mixtures into first and second component parts through the retention of one component in a bed of adsorption material while allowing the other components to flow therethrough. In order to provide for continuous operation, it is common practice to use two beds of adsorption material and sequentially adsorb one bed while desorbing the other bed. A first series of solenoid valves associated with the two beds allows the fluid mixture to freely flow to a first of the two beds where one component is retained and a product effluent allowed to flow to a storage container through a conduit. At the same time a portion of the product effluent enters a second of the two beds and purges the same of the one component previously retained therein. After a period of time, a signal from a timing mechanism deactivates the first series of solenoid valves and activates a second series of solenoid valves to reverse the communication of the fluid mixture from the first of the two beds to the second. The first bed of adsorption material previously producing the product effluent is now purged by a portion of the product effluent produced in the second bed.
Theoretically, the volume of fluid mixture passing through the first and second beds of adsorption material should be equal. However in practice it has been observed that the beds of adsorption materials are nearly always different. This difference can be the result of minute changes in size betwen the beds, variations in the density of the beds, and variations in the quality of the beds such as porosity and mositure content. In addition, a few seconds change in the operation of the solenoid by the timing mechanism can cause a degradation of the beds.
Thus, one of the two beds is always producing more of a product effluent than the other. The overproducing bed experiences a component breakthrough which dilutes the product effluent during its adsorption part of the operational cycle while the underproducing bed has an excessive amount of the component retained therein at the initiation of its adsorption cycle. The underproducing bed never reaches its output potential since the adsorption cycle is terminated before the product effluent output peaks.
One method of providing identical beds requires the testing of the adsorption capacity of the beds as they are produced and thereafter selecting matching beds of the same capacity for each unit. Unfortunately, this type of production does not lend itself for rapidmanufacturing production.
Another method of acquiring optimum output from an oxygen separator requires the use of an electrical timer whereby the operation of the solenoid valve can be varied to match the adsorption capacity of the beds. The cycle of adsorption of the underproducing bed is lengthened while the cycle of adsorption of the overproducing bed is shortened until both beds are operating at top efficiency. However, this solution is only temporary since after an extended period of time the beds become unbalanced in the opposite direction since the retained component is not completely purged from the one bed.
SUMMARY OF THE INVENTION
In evaluating the operation of oxygen separator apparatus, we discovered that the fluid pressure in the underproducing bed is always less than in the overproducing bed. We found that an operational balance between beds of adsorption material can be achieved by controlling the cycling through the use of a pressure control system.
The pressure control system includes a first series of valves responsive to a first pneumatic signal for allowing a fluid mixture to be presented to a first bed while purging any component of the fluid mixture retained in a second bed with a portion of first product effluent flowing from the first bed during a first mode of operation, and a second series of valves responsive to a second pneumatic signal for allowing the fluid mixture to be presented to the second bed while purging any component of the fluid mixture retained in the first bed with a portion of the second product effluent from the second bed during a second mode of operation. A first sensor is connected to the first bed for developing a first signal corresponding to the pressure level of the product effluent in the first bed and a second sensor is connected to the second bed for developing a second signal corresponding to the pressure level in the second bed. A logic sequencer responsive to the first and second signals supplies the first and second valves with corresponding first and second pneumatic signals for sequentially establishing the first and second modes of operation.
It is the object of this invention to provide a fulid separator with a pneumatically operated cycle control to optimize the production of a product effluent.
It is another object of this invention to provide an oxygen separator having first and second beds of adsorption material with a pneumatic control for transferring the communication of a supply fluid between the first and second beds as a function of the differential fluid pressure between these beds.
It is another object of this invention to provide a pneumatic control system for maintaining a balance in the oxygen separation capabilities of two molecular sieve beds independent of the dissimilarities in the beds by terminating the adsorption of each bed at a fixed pressure in the bed.
These and other objects should become apparent from reading this specification and viewing the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of a fluid separator system having cycle control made according to the principles of this invention;
FIG. 2 is a graph showing the relationship of the fluid pressure in the first and second beds of adsorption material in a typical oxygen separator during a cycle of operation;
FIG. 3 is a graph illustrating the operation of first and second sensors associated with the logic sequensor in the cycle control; and
FIG. 4 is a sectional view of a typical NOR gate used in the logic sequensor of the fluid separator of FIG. 1.
DETAILED DESCRIPTION
The fluid separation system shown in FIG. 1 includes a compressor 12 through which air from the atmosphere is drawn through a first filter device means 14 wherein dust and other airborne particles and bacterial particles which may be harmful to the health of a recipient or patient, are removed. The compressor 12 is of the rotary vane type wherein the air is pressurized to between 10-15 psig. The vanes in this type compressor are usually made of carbon. Due to the speed that the vanes are rotated, some carbon dust may be present in the pressurized air and necessitates locating a second filter 18 at the exit of the compressor 12 adjacent supply conduit 20 in order to insure a clinically pure air supply. The supply conduit 20 connects the compressor 12 with a surge tank 22. A oneway check valve 24 located at the entrance of the surge tank 22 prevents back flow into the supply conduit 20 from the surge tank 22 during the switching mode of the fluid separation system.
The surge tank 22 is connected to a first bed of adsorption material retained in a first chamber 26 by a first supply conduit 28 which passes through a first supply valve 130 and to a second bed of adsorption material retained in a second chamber 32 by a second supply conduit 34 which passes through a second supply valve 230.
The first and second beds of adsorption material 26 and 32 are connected to storage container 38 through an outlet conduit 40 and to each other through conduit 42 and 44, respectively. A restriction 46 located in conduit 42 allows a portion of the output product effluent of the bed connected to the fluid mixture to continually flow into the other bed of adsorption material and purge any component retained therein to the atmosphere.
A third valve 330 located in conduit 44 allows the fluid pressure in the first and second beds of adsorption material to equalize during the shifting of the adsorption mode of operation between the first and second beds 26 and 32.
In addition, the first and second beds of adsorption material 26 and 32 are connected to the atmosphere through atmospheric control valves 430 and 530. Atmospheric control valve 430 is connected to the first bed of adsorption material 26 and is operated in conjunction with the second supply valve 230, hereinafter, these valves are referred to as a second series of valves. Similarly, atmospheric control valve 530 is operated in conjunction with the first supply valve 130, hereinafter, these valves are referred to as a first series of valves.
The structure and operation of valves 130, 230, 330, 430, and 530 are identical with the exception of plumbing changes required to operate the separating system. Therefore, only the structure in valve 130 is described in detail. Unless necessary for the understanding of the invention the elements identified in valve 130 are identified in the other valves by placing the appropriate 100 character with the identification number.
Valve 130 has a housing 54 with a chamber 56 located therein. An entrance or first port 58 connects chamber 56 to supply conduit 28. An exit or second port 60 connects chamber 56 to the first bed of adsorption material 26. A port 62 connects chamber 56 to the atmosphere. A diaphragm 64 separates the entrance and exit ports 58 and 60 from port 62 to establish a supply chamber 66. A passage 68 connects the entrance port 58 to a first control chamber 90. The first control chamber 90 has a port 70 through which a first operational control signal is communicated from a pneumatic logic sequencer 100. The first control chamber 90 is connected to chamber 56 by a second passage 72. A diaphragm 78 separates the port 70 from the control chamber 90 to prevent the first operational signal from being communicated to chamber 56. A driver diaphragm 74 separates chamber 56 from the atmosphere to establish a power chamber 76. The power chamber 76 is connected to a second control chamber 92 by a third passage 94. A diaphragm 80 separates the second control chamber 92 from a port 82 through which a second operational control signal is communicated from the pneumatic logic sequencer 100. A port 84 connects the second control chamber 92 to the atmosphere.
Chamber 56 has a wall 96 for retaining a linkage member 98 which joins the driver diaphragm 74 to diaphragm 64. A spring 86 which acts on diaphragm 64 urges driver diaphragm 74 toward wall 77 in chamber 76 to allow the fluid mixture in the supply conduit 28 to flow past seat 88 and into the supply chamber 66.
A projection 48 which surrounds passage 50 has threads 52 thereon. Threads 52 are matched with threads 452 on projection 448 extending from housing 454 of atmospheric valve 430. Chamber 466 in the atmospheric valve is connected to the atmosphere through passage 450. The first bed of adsorption material 26 is connected to the atmosphere through conduit 47, passage 50, inlet port 458, control chamber 466 and passage 450 during the second mode of operation.
The second valve 230 is connected to the second bed of adsorption material 32 and atmospheric valve 530 is connected to the second valve 230 in the same manner as the first valve 130 and atmospheric valve 430 are connected to each other and the first bed of adsorption material 26.
In the third valve 330, port 358 is connected to the second bed of adsorption material 32 and port 360 is connected to the first bed of adsorption material 26. In response to an equalization signal from the logic sequencer 100, valve 330 provide free communication between the first and second beds through the supply chamber 366.
The sequential operation of valves 130, 230, 330, 430 and 530 is completely controlled by operational signals generated and developed in the logic sequencer apparatus 100.
In more particular detail, the logic sequencer apparatus 100 includes a housing 102 with a first chamber 104, a second chamber 106 and a third chamber 108 located therein.
The first chamber 104 has a port 110 connected to the atmosphere, a port 112 connected to conduit 114 carrying a source of pressurized air, and a port 116 connected to conduit 118 extending from outlet conduit 45 of the first bed of adsorption material 26. A diaphragm 120 attached to housing 102 separates port 116 from the atmospheric port 110 and port 112 to establish a first pressure sensor chamber 122 in the first chamber 104. A spring 124 located in chamber 104 acts on and urges diaphragm 120 against the wall 126 which separates the first chamber 104 from the second chamber 106.
The second chamber 106 has a series of ports 140 connected to the atmosphere, a port 142 connected to conduit 118 going to the first bed of adsorption material 26, a port 144 connected to conduit 146 going to the second bed of adsorption material 32, a port 148 connected by conduit 150 to conduit 114 carrying a supply of pressurized air, and port 152 connected by conduit 154 to conduit 156 carrying a supply of pressurized air. A diaphragm 158 attached to the housing 102 separates port 142 from the series of ports 140 to establish a first product effluent pressure sensor chamber 160 and a diaphragm 162 attached to the housing 102 separates port 144 from the series of ports 140 to establish a second product effluent pressure sensor chamber 164. A series of struts 166 and 168 connect the diaphragm 158 to diaphragm 162, such that any movement in one of these diaphragms toward ports 148 and 152 moves the other away from these ports by the same amount.
The third chamber 108 has a port 170 connected to the atmosphere, a port 172 connected to conduit 156 carrying the source of air under pressure, and a port 174 connected to conduit 146 going to the second bed of adsorption material 32. A diaphragm 176 attached to housing 102 separates port 174 from the atmospheric port 170 to establish a second pressure sensor chamber 178 in the third chamber 108. A spring 180 located in chamber 108 acts on and urges diaphragm 176 toward shoulder 182 which separates the chamber 178 from chamber 164.
Conduit 150 connected to port 148 is also connected to a first NOR gate 184 by a conduit 185. NOR gate 184 in response to a first sensor signal generated in chamber 104 supplies NOR gate 186, port 270 in valve 230, port 482 in valve 430, and NOR gate 188 with an actuation signal in the first mode of operation. Similarily, conduit 154 connected to port 152 is also connected to a second NOR gate 190 by conduit 189. NOR gate 190 in response to a second sensor signal generated in chamber 108 supplies NOR gate 192, port 70 in valve 130, port 570 in valve 530 and NOR gate 188 with an actuation signal in the second mode of operation.
NOR gate 188 in turn supplies port 370 in valve 330 and NOR gate 194 with actuation signals during the first and second modes of operation to prevent fluid communication through the supply or control chamber 366 and during the transition in switching between the first and second modes with an appropriate signal to allow fluid to freely flow between ports 358 and 360.
A flip flop switch 197 consisting of NOR gates 196 and 198 is attached to conduit 114 and 156, respectively, and in response to the first and second sensor signals, provide NOR gates 184 and 190 with termination and actuation signals to establish the first and second modes of operation in the oxygen separator.
The NOR gates in the logic sequencer 100 of which 186 and 192 are illustrated in FIG. 4, have a housing 200 with a chamber 206 located therein. A restriction or seat surface 204 separates chamber 206 into an inlet chamber 210 and an outlet chamber 212. A diaphragm 214 further separates the chamber into a control chamber 220 which extends over the wall or restriction 204 and is substantially equal in surface area to the sum of the inlet and outlet chambers 210 and 212. The control chamber 220 is connected to an actuation NOR gate and in response to an operation signal interrupts the flow of a source of fluid under pressure (usually air) from port 202 to the outlet port 218 by moving the diaphragm 214 against the seat or restriction 204. The control signal is substantially equal to the pressure of the fluid presented to the inlet port 202 and therefore, because of the larger area of the diaphragm in the control chamber 220, holds the diaphragm against the seat or restriction 204 in opposition to the force of the fluid acting on the surface of the diaphragm 214 in the inlet chamber 210.
When the pressure signal to the control chamber 220 is terminated, the fluid pressure in the inlet chamber 210 acts on and moves the diaphragm away from the seat or restriction to permit a pneumatic fluid pressure signal to pass through the NOR gate.
A further description of such NOR gate can be found in U.S. Pat. No. 3,318,329.
PREFERRED MODE OF OPERATION OF THE INVENTION
The fluid separation system shown in FIG. 1 is activated whenever a pressurized fluid mixture is presented to surge tank 22. As shown in FIG. 1, the pressurized fluid mixture (air) is derived from compressor 12; however, a bottled pressurized fluid mixture could be substituted therefor.
Initially, the flip flop switch 197 is in either a first or second conduction state as illustrated by lines 240 for NOR gate 196 or line 242 for NOR gate 198 as shown in FIG. 3. If the flip flop switch 197 is in the state wherein the first mode of operation exists, a signal to NOR gate 184, as illustrated by line 244 in FIG. 3, prevents the communication of a control signal to the control chamber in NOR gate 186, as illustrated by line 246 in FIG. 3, this allows a fluid pressure signal from NOR gate 184 to be presented to port 282 in valve 230 to prevent fluid from flowing through passage 281 to the atmosphere while allowing the fluid mixture to flow through passages 34 and 268 past diapgragm 278 into passages 272 and 294 for presentation to chamber 276. The fluid mixture pressure acts in chamber 276 on the driver diaphragm 274 to move diaphragm 264 against seat 288 and prevent the flow of the fluid mixture through supply chamber 266 to the second bed of adsorption material 32.
At the same time, the fluid pressure signal from NOR gate 186 is presented to diaphragm 480 in atmosphere valve 430 to prevent communication of the fluid mixture under pressure in chamber 476 from flowing past seat 479 to the atmosphere through passage 481. The fluid mixture under pressure in passage 468 flows past seat 491 for communication through passages 472 to chamber 476 where the pressure acts on the driver diaphragm 474 to move diaphragm 464 into contact with seat 488 and prevent the flow of fluid through the supply chamber 466 to the atmosphere through passage 450. The pressure signal from NOR gate 186 is also presented to NOR gate 188 to interrupt any pressure signal therefrom. The pressure signal from NOR gate 188 follows a curve illustrated by line 247 in FIG. 3 to allow NOR gate 194 to present diaphragm 380 with a pressure signal which follows a curve illustrated by line 245 in FIG. 3. The pressure of the product effluent in conduit 44 acts on driver diaphragm 374 and moves diaphragm 364 against seat 388 to prevent communication between the first and second beds of adsorption material at this time.
In this first mode of operation, the pressure signal from NOR gate 190 follows a curve illustrated by line 248 in FIG. 3. Without a control signal in NOR gate 190, a fluid pressure signal flows therefrom which interrupts the flow of a pressure signal from NOR gate 192. The output pressure signal from NOR gate 192 follows a curve illustrated by line 249 in FIG. 3.
The pressure signal from NOR gate 190 is presented to diaphragm 80 in valve 130 to prevent the communication of the pressurized fluid mixture present in passage 65 from flowing past seal 91 to diaphragm 578 in valve 530 and to prevent communication of any product effluent present in passage 568 from flowing past seat 591.
The pressure signal from NOR gate 190 upon presentation to NOR gate 192 interrupts any pressure signal therefrom and allows spring 86 to move diapharagm 64 away from seat 88. With diaphragm 64 off seat 88, the fluid mixture is free to flow through supply chamber 66 into passage 50 for distribution through conduit 47 to the first bed of adsorption material 26.
Similarly, spring 586 acts on moves diaphragm 564 away from seat 588 to communicate the second bed of adsorption material 32 to the atmosphere. Chamber 576 is also connected to the atmosphere through passage 581 since diaphragm 580 is not urged against seat 591 by a pressure signal in the first mode of operation.
Thus, the fluid mixture freely flows from the supply conduit 28 to the first bed of adsorption material 26 where one component is retained therein and as a product effluent flows through conduit 27. The product effluent in conduit 27 flows past check valve 41 into conduit 40 for distribution to either a supply chamber 38 or directly to a patient. A portion of the product effluent flows past restriction 46 in conduit 42 to the second bed of adsorption material 32. This portion of the product effluent passes through the second bed 32 and desorbs any component retained therein by flowing in conduit 37 to passages 250 and 268 for communication to passage 558 in atmosphere valve 530. Since diaphragm 564 of valve 530 is away from seat 588, the product effluent port 550 and component freely flows through chamber 566 to the atmosphere through port 550.
The product effluent in conduit 27 is presented to the logic sequencer apparatus 100 through conduit 118. The fluid pressure in the product effluent is simultaneously presented to sensor chambers 122 and 160. However, spring 124 holds diaphragm 120 against wall 126 and therefore only diaphragm 158 initially responds to this pressure by moving against the nozzle end of port 148 to restrict the flow of fluid therefrom. The restricted flow of fluid through port 148 creates a first pressure signal illustrated by curve 183 in FIG. 3, which is presented to NOR gate 184 in conduit 185 to initiate the first mode of operation.
The fluid pressure in the first bed of adsorption material 26 continues to increase and follows a curve illustrated by line 25 in FIG. 2. When the fluid pressure reachs peak 29, the pressure of the product effluent communicated to sensor chamber 122 in the logic sequencer 100 is sufficient to overcome spring 124 and move diaghragm 120 against the nozle end of port 112. With flow of the fluid in conduit 114 downstream from restriction 113 terminated, a first pressure or sensor signal, illustrated by curve 115 in FIG. 3, is presented to NOR gate 196 of the flip flop switch 197 through conduit 195. The pressure or first sensor signal immediately changes the signal output from NOR gate 196 to interrupt the actuation signal to NOR gate 184.
At the same time NOR gate 198 supplies an actuation signal to NOR gate 190 which interrupts the pressure signal therefrom. Thereafter NOR gate 192 presents a pressure signal to diaphragm 80 which allows the fluid pressure in conduit 68 to flow past seat 91 and into chamber 76. The fluid pressure in chamber 76 acts on and moves diaphragm 64 against seat 88 by overcoming spring 86 to interrupt the flow of the pressurized fluid mixture through the supply chamber 66 to the first bed of adsorption material 26 to terminate the first mode of operation.
At the same time, the pressure signal from NOR gate 192 supplies diaphragm 580 with a pressure signal to seal seat 591 and allow the fluid pressure of the product effluent to flow to chamber 576. The fluid pressure acts on and moves diaphragm 564 against seat 588 by overcoming spring 586 to interrupt the flow through chamber 566 to the atmosphere.
The interruption of the pressure signal from NOR gate 190 removes the control pressure signal from NOR gate 188 and allows a pressure signal to issue therefrom. The pressure signal from NOR gate 188 acts on diaphragm 378 to interrupt communication between chamber 376 and passage 368. This pressure signal from NOR gate 188 also acts on NOR gate 194 to interrupt the pressure signal therefrom acting on diaphragm 380. Thus, spring 386 moves diaphragm 364 away from seat 388 and permits free communication between the first and second beds of adsorption material 26 and 32 to equalize the pressure therebetween.
The pressure in the first and second beds of adsorption material is compared in chambers 160 and 164 of the logic sequencer 100. As the pressure equalizes, diaphragm 158 moves away from nozzle end 148 to interrupt the actuation signal going to NOR gate 184. Thereafter NOR gate 184 produces a pressure signal which is communicated to the control chambers in NOR gates 186 and 188.
The pressure signal in the control chamber of NOR gate 188 terminates the pressure signal issuing therefrom and allows fluid communication from passages 368 to chamber 376.
At the same time, NOR gate 194 produces a pressure signal which acts on diaphragm 380 to interrupt communciation to the atmosphere through port 384. Thereafter, the fluid pressure in chamber 376 acts on and moves diaphragm 364 against seat 388 to terminate communication through chamber 366 between the first and second beds 26 and 32 of adsorption material.
The pressure signal from NOR gate 184 is also transmitted to diaphragm 278 to interrupt fluid communication from passage 268 to chamber 276. At the same time, this pressure signal is also communicated to the control chamber in NOR gate 186 to interrupt a fluid pressure signal emanating therefrom to diaphragm 280. This permits spring 286 to move diaphragm 264 away from seat 288 and allows the pressurized fluid mixture in conduit 34 to enter the supply chamber 266 for distribution to the second bed of adsorption material 32.
The product effluent from the second bed of adsorption material 32 is carried in conduit 33 past check valve 43 and into the outlet conduit 40 for distribution to either the storage container 38 or a patient.
A portion of the product effluent from the second bed of adsorption material 32 is communicated through restriction 46 to adsorb or purge any component retained in the first bed of adsorption material 26 by flowing to the atmosphere through conduit 47, passage 50, passage 458, chamber 466 and passage 450.
The pressure of the product effluent in conduit 33 builds up in a manner illustrated by curve 35 in FIG. 2, and is communicated through conduit 146 to chambers 164 and 178 in the iogic sequencer 100. This second product effluent pressure is communicated into chamber 164 and moves diaphragm 162 against nozzle end of port 152 to inititate a second actuation signal illustrated by curve 187 in FIG. 3. This second actuation signal is relayed through conduit 189 to NOR gate 190.
As the second mode of operation continues, the fluid pressure of the product effluent in conduit 33 increases until peak 39, as shown in FIG. 2, is reached. The peak fluid pressure is communicated into chamber 178 and acts on and moves diaphragm 176 against the nozzle end of port 172 to establish a second sensor signal 157.
The second sensor signal 157 is communicated to NOR gate 198 to terminate the second actuation signal to NOR gate 190 and allow NOR gate 196 to initiate an actuation signal to NOR gate 184 to start the transfer of communication of the pressurized fluid mixture from the second bed of adsorption material 32 to the first bed of adsorption material 26 in a manner as described above with respect to the tranfer form the first bed to the second bed.
The pneumatic logic sequencer 100 is adapted to respond to the same fluid pressure level in the first and second beds of adsorption material 26 and 32, irrespectively of the time involved in reaching the peak fluid pressure. The fluid pressure sensor signals developed in the logic sequencer 100 are controlled by the resistance of springs 124 and 180. By matching the springs 124 and 180, the peak fluid pressure 29 and 39 as illustrated in FIG. 2, are identical and thus the production of the product effluent from the beds of adsorption material 26 and 32 is optimized.
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A control system for sequentially connecting a pressurized fluid mixture to first and second beds of adsorption material to separate a component from the fluid mixture and produce a product effluent. A first valve mechanism allows the fluid mixture to flow to the first bed and a portion of the product effluent to purge the component from the second bed in a first portion of a mode of operation. A second valve mechanism allows the fluid mixture to flow to the second bed and a portion of the product effluent to purge the component from the first bed in a second portion of the mode of operation. A first sensor develops a first signal corresponding to the fluid pressure of the product effluent in the first bed and a second sensor develops a second signal corresponding to the fluid pressure of the product effluent in the second bed. A pneumatic logic sequencer connected to the first and second sensors responds to the first and second signals to sequentially operate the first and second valves and establish a cycle of operation.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/953,961, filed Jul. 30, 2013, which is a continuation of U.S. patent application Ser. No. 11/735,869, filed Apr. 16, 2007, now U.S. Pat. No. 8,496,926, the entire contents of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The inventions described below relate the field of cardiology.
Chronic Myocardial Infarction refers to myocardial tissue which has died as the result of myocardial infarct, and has over the course of time become remodeled to scar tissue within the myocardium. Left untreated, myocardial infarction induces global changes in the ventricular architecture in a process called ventricular remodeling. Eventually, the patient experiences ventricular dilation and ventricular dysfunction. This ventricular remodeling is a major cause of heart failure.
While there are several suggested means of ameliorating the effects of acute myocardial infarction (immediately after the event leading to infarct), no significant therapy has been proposed or implemented for the amelioration or reversal of chronic myocardial infarction and the deleterious effects of infracted tissue after substantial transformation or remodeling of the infracted tissue to scar tissue.
SUMMARY OF THE INVENTION
The method of treating chronic myocardial infarction described below comprises injection of autologous bone marrow derived mononuclear cells, or cells derived from those mononuclear cells, into the myocardium. These cells are injected near or in the chronic infracted tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing improvement in ejection fraction of the patients in an experimental group, after injection of autologous bone marrow derived mononuclear cells.
FIG. 2 is a graph showing improvement in exercise tolerance of the patients in an experimental group, after injection of autologous bone marrow derived mononuclear cells.
FIG. 3 is a graph showing improvement in ventricular diastolic volume of the patients in an experimental group, after injection of autologous bone marrow derived mononuclear cells.
DETAILED DESCRIPTION OF THE INVENTION
Chronic myocardial infarction refers to the condition of infracted tissues after the infracted tissue has been remodeled by natural wound healing responses and comprises, after such remodeling, scar tissue, which is substantially dead. This is distinct from ischemic tissue characteristic of chronic ischemia, which refers to tissue which is chronically hypoxic due to lack of sufficient blood flow, but is still viable even if not fully active in the muscular and electro-physiologically activity of the heart. The method starts with identifying patients afflicted with chronic myocardial infarction. Once patients with chronic myocardial infarction are identified, their suitability for treatment under the method currently requires a low ejection fraction (less that about 40%). In our experiments aimed at determining if the treatment is safe, we included patients with left ventricular dysfunction (less that about 40% but not less than about 30%) that were not candidates for ventricular aneurysm surgery, implantable defibrillators, or valve repair or replacement, while excluding patients with active infections, malignancies, high grade atrioventricular block, sustained ventricular tachyarrythmias, a recent MI (less than 4 weeks old), presence of an artificial aortic valve, recent history of alcohol or drug abuse or evidence of other multi-system disease. However, given the results of our experiments, we expect that the treatment could benefit all patients suffering from chronic myocardial infarction so long as they can tolerate the procedure.
Immediately prior to the catheterization necessary to delivery the autologous bone marrow cells, the cells are collected from suitable sites within the patient, such as the posterior iliac crest, vertebral body and/or sternum. Bone marrow mononuclear cells are isolated by suitable methods such as density gradient on Ficoll-Paque Plus tubes (GE Healthcare, UK) through 100 .mu.m nylon mesh to remove cell aggregates, and re-suspended in Ringers solution at a concentration of 1.times.10.sup.8 cells/ml in a total volume of 1.3 ml. These cells are prepared for injection back into the patient within about 4 to 6 hours after harvesting. The bone marrow derived mononuclear cells include CD-34 positive cells, CD-133 positive cells, and CD-90 positive cells (mesenchymal stem cells) which may also be separately isolated for injection to treat chronic myocardial infarction. Preferably at least 40% of the cells isolated comprise CD-34 positive cells, CD-90 positive cells, and CD-133 positive cells or a combination thereof.
Just prior to cell delivery, the doctors performing the cell delivery use various techniques, including ECG's, echocardiography, and baseline orthogonal ventriculography data to define the target infarct tissue zones. Access to the target infarct zone is preferably via catheter, transendocardially (with the catheter tip in the endocardial space) into the myocardium. Intramyocardial delivery may also be accomplished through a trans-coronary venous approach as described in BioCardia's U.S. Pat. No. 6,585,716, through a trans-coronary arterial approach, or a trans-epicardial approach. Any suitable catheter system can be used, though the BioCardia™ helical infusion catheter and steerable guide catheter are particularly well suited to the method. Dosage may range from three injections of 0.1 to 0.2 ml of cell solution at a concentration of 10.sup.8 (one hundred million) cells/ml (totaling about 5.times.10.sup.7 cells) to 11 injections of 0.1 to 0.2 ml of cell solution at a concentration of 1.2.times.10.sup.8 cells/ml for a total of 1.2.times.10.sup.8 cells spread over numerous injection cites proximate the target infarct tissue. The solution containing the cells is injected near or at the site of an infarct, in several small injections proximate the target infarct. Each injection is performed slowly, and the helical injection catheter is left in the injection site to dwell for a substantial period (about 15 to 30 seconds) to prevent back-leakage of the solution into the endocardial space of the ventricle.
The efficacy of the treatment is reflected in FIGS. 1 through 3 , which show that chronic myocardial infarct patients treated with autologous bone marrow derived mononuclear cells benefit from improved ejection fraction, improved exercise tolerance, and reduced ventricular dilation. As shown in FIG. 1 , ejection fraction of the patients, as measured by 2D echocardiography, demonstrates a statistically significant increase at 1 week (P=0.02), 12 weeks (P=0.01), 6 months (P=0.001), and 12 months (P=0.0001) as compared to baseline. All patients in the experimental group showed an increase in this parameter over baseline at 6 months and 12 months. Smaller long term improvements in diastolic volume and exercise tolerances were noted in our experimental group, as shown in FIGS. 2 and 3 . Given the results of our experiment with a small number of patients, the method results in significantly improved ejections fraction, reduced ventricular dilation, and improved exercise tolerance. No increase in ventricular arrhythmias was detected in any patient in the experimental group.
Peripheral blood derived mononuclear cells (PBMC) and adipose tissue derived mononuclear cells can be also be used in the treatment, as can cells derived from those mononuclear cells harvested from the peripheral blood or adipose tissue. While the preferred embodiments of the devices and methods have been described in reference to the environment in which they were developed, they are merely illustrative of the principles of the inventions. Other embodiments of the method, including sources of cells and methods of isolation, and particular constituent cells of the injected cell population may be devised without departing from the spirit of the inventions and the scope of the appended claims.
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A method of treating chronic post-myocardial infarction including helical needle transendocardial delivery of autologous bone marrow (ABM) mononuclear cells around regions of hypo or akinesia in chronic post-myocardial infarction (MI) patients. The treatment is safe and improves ejection fraction (EF).
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RELATED APPLICATIONS
This patent application is related to U.S. Pat. No. 5,269,384, entitled "Method and Apparatus for Cleaning a Borehole", issued Dec. 14, 1993 to Cherrington, which is incorporated by reference herein.
TECHNICAL FIELD OF THE INVENTION
This invention relates in general to hole drilling, and more particularly to a device for removing cuttings from the hole.
BACKGROUND OF THE INVENTION
Underground conduits are widely used for the transmission of fluids, such as in pipelines and the like, as well as for carrying wires and cables for the transmission of electrical power and electrical communication signals. While the installation of such conduits is time-consuming and costly for locations where the earth can be excavated from the surface, the routing of such conduits becomes more difficult where such surface excavation cannot be done due to the presence of surface obstacles through which the excavation cannot easily proceed. Such surface obstacles include highways and railroads, where the installation of a crossing conduit would require the shutdown of traffic during the excavation and installation. Such surface obstacles also include rivers, which present extremely difficult problems for installing a crossing conduit, due to their size and the difficulty of excavation thereunder.
Prior methods for the installation of conduits have included the use of directional drilling for the formation of an inverted underground arcuate path extending between two surface locations and under the surface obstacle, with the conduit installed along the drilled path. A conventional and useful method for installing such underground conduits is disclosed in U.S. Pat. No. 4,679,637, issued Jul. 14, 1987, assigned to Cherrington Corporation, and incorporated herein by this reference. This patent discloses a method for forming an enlarged arcuate bore and installing a conduit therein, beginning with the directional drilling of a pilot hole between the surface locations and under a surface obstacle such as a river. Following the drilling of the pilot hole, a reamer is pulled with the pilot drill string from the exit opening toward the entry opening, in order to enlarge the pilot hole to a size which will accept the conduit, or production casing in the case of a pipeline conduit. The conduit may be installed during the reaming operation, by the connection of a swivel behind the reamer and the connection of the conduit to the swivel, so that the conduit is installed as the reaming of the hole is performed. Alternatively, the conduit can be installed in a separate operation, following the reaming of the pilot hole (such reaming referred to as "pre-reaming" of the hole). Additional examples of the reaming operation, both as pre-reaming and in conjunction with the simultaneous installation of the product conduit, are described in U.S. Pat. No. 4,784,230, issued Nov. 15, 1988, assigned to Cherrington Corporation and incorporated by this reference.
While the above-described methods are generally successful in the installation of such conduit, certain problems have been observed, especially where certain types of sub-surface formations are encountered. Referring now to FIGS. 1 and 2, examples of such problems in the installation of conduit in an underground arcuate path will now be described.
FIG. 1 illustrates the reaming operation described above, in conjunction with the installation of production conduit as the reamer is pulled back. In the example of FIG. 1, entry opening 0 is at surface S on one side of river R; exit opening E is on the other side of river R from entry opening 0. At the point in the installation process illustrated in FIG. 1, a drilling apparatus, including a hydraulic motor 14 mounted on a carriage 16 which is in place on an inclined ramp 12, has drilled the pilot bore hole B from entry 0 to exit E, using drill string 10, and the reaming and installation is in progress. Motor 14 is now pulling reamer 48, to which production conduit 46 is mounted, back from exit E toward entry 0. Reamer 48 is larger in diameter than the diameter of production conduit 46. Upon completion of the reaming operation of FIG. 1, if successful, production conduit 46 will be in place under river R, and extending between exit E and entry 0.
Referring now to FIG. 2, a close-up view of the location of reamer 48 and production conduit 46 in FIG. 1 is now illustrated. Leading drill string section 10C is attached by way of tool joint 52 to reamer 48, reamer 48 having cutting teeth at its face. Swivel 50 connects production conduit 46 to reamer 48, by way of extension 62 connected to a sleeve 66 on conduit 46. As is evident from FIGS. 1 and 2, bore hole B is enlarged to enlarged opening D by operation of reamer 48. Conventional sizes of conduit 46 are on the order of 20 to 48 inches in outside diameter, with the size of reamer 48 greater in diameter than conduit 46. Due to reamer 48 being larger than conduit 46, an annulus 68 surrounds conduit 46 as it is pulled into the hole D. Provision of the annulus 68 allows for reduced friction as the conduit 46 is placed therein.
As noted above, prior techniques have also included a pre-reaming step, wherein a reamer, such as reamer 48, is pulled back from exit E to entry 0 without also pulling production conduit 46 into the reamed hole. In such a pre-reaming step, a following pipe generally trails reamer 48 in such the same manner as conduit 46 trails reamer 48 in FIGS. 1 and 2, to provide a string for later installation of conduit 46. Such a trailing pipe will be of a much smaller size than conduit 46 of FIGS. 1 and 2, for example on the order of five to ten inches in diameter.
It has been observed in the field that both the pre-reaming and reaming with installation operations are subject to conduit or pipe sticking problems, especially as the size of the production conduit increases in diameter, and as the length of the path from entry 0 to exit E increases. Such sticking is believed to be due, in large degree, to the inability to remove cuttings resulting from the reaming operation. Due to the large volume of earth which is cut by way of the reaming operation, and the generally low fluid flow velocity of drilling or lubricating mud or fluid into the reaming location, the velocity of cuttings circulating from the reaming location is minimal. While the mud or other lubricating fluid flow could be increased in order to increase the velocity of the cuttings from the reaming location, such an increase in the velocity of the fluid could result in such undesired results as hole wall erosion and fracturing through the formation.
Due to the inability to sufficiently remove the cuttings during the reaming operation, it is believed that the cuttings pack together near the location of the reamer. Many of the cuttings from the reaming operation are heavier than the fluid transporting them and, in such large diameter holes as are required for the installation of conduit, these large cuttings will fall out or settle toward the bottom of the hole first, and then build up into a circumferential packed mass, causing a poor rate of reaming. Referring to FIG. 2, where a production conduit 46 is being pulled through with reamer 48, it is believed that such packing will begin at locations P surrounding the leading end of conduit 46, and also along the sides of conduit 46 in annulus 68. As the cuttings pack together, squeezing whatever water or fluid is present therein, the density of the packed mass increases. Upon sufficient packing, it is believed that pressure builds up ahead of locations P, toward the bit of reamer 48, such pressure resulting from the mud or fluid continuing to be pumped into the reaming location with the return flow reduced at locations P around conduit 46 in annulus 68. It is also believed that this buildup of pressure will also force cuttings into bore hole B ahead of reamer 48, and that these cuttings will also begin to pack, most likely at locations P' near the first tool joint 70 ahead of reamer 48.
The buildup of pressure between locations P and P' surrounding reamer 48 causes significant problems in the reaming operation. Such effects have been observed in the field during reaming operations, when the reamer cannot be rotated, pulled or pushed at a particular location in the operation. It should be noted that the sticking of the reamer occurs both for the pre-reaming operation described hereinabove and for the combined reaming and pulling operation. It should further be noted that the pressure buildup described hereinabove is believed to be worse in high pressure formations such as clay.
Another undesired effect resulting from the buildup of pressure when the reamer cuttings are insufficiently removed is similar in nature to differential sticking in the downhole drilling field. As is well known in the downhole drilling art, differential sticking of the drill string occurs when the pressure of the drilling mud surrounding the drill string is greater than the pressure exerted by the surrounding formation. In the event that the caking of drilling mud and the structure of the well bore is not strong enough to maintain its shape when presented with such a differential pressure, the pressure of the drilling mud can force the drill string into the formation, holding it there with sufficient pressure that it cannot be released from the surface.
It is now believed that similar effects can be present in the field of installation of underground conduit, due to insufficient removal of the reaming cuttings. If the pressure near reamer 48, when packed off as described hereinabove, is sufficiently greater than the pressure exerted by a surrounding formation, the conduit 46 can be driven into the formation, causing sticking of the conduit 46 thereat. It should be noted that the installation of underground conduit is particularly susceptible to such sticking, since much of the formations underlying rivers are sedimentary or alluvial formations, with relatively thin layers of differing strength. Accordingly, the drilling and reaming operations in river crossing installations are exposed to many differing formations along the length of the path, with the likelihood of encountering a weak (in pressure) formation being relatively large. Accordingly, such pressure buildup due to insufficient reaming cutting removal can cause conduit sticking at particular locations along the underground path.
Furthermore, it should be noted that the insufficient removal of cuttings impacts the reaming operation itself. If cuttings are not sufficiently removed from the reaming location, a number of cuttings will tend to be present in front of reamer 48 of FIG. 2; as a result, reamer 48 will tend to recut its own cuttings, rather than cutting the earth in its path and enlarging the hole. This results in poor penetration rates for the reaming operation. As noted above, as the reaming rate slows, the pressure buildup between the packed locations will accelerate, further degrading the operation and increasing the likelihood of the reamer and conduit sticking.
In addition, the recutting of the cuttings results in a high degree of reamer wear, both at the teeth and also in the parent metal of reamer 48. In rotor reamers, such wear has been observed also at the seals and bearings. This has also been observed for reamers which use carbide-coated rotating cones as the cutting bits, in similar manner as a downhole tri-cone bit; while the carbide wears slowly, the insufficient removal of the cuttings has been evidence in significant wear of the parent metal of the reamer. Furthermore, as the cuttings become smaller due to multiple recutting cycles, the cuttings which are removed with the drilling mud are much more difficult to process by the solids control system.
Other methods for installing conduit in an underground path includes forward thrust techniques, such as described in U.S. Pat. Nos. 4,176,985, 4,221,503 and 4,121,673. Particularly, U.S. Pat. No. 4,176,985 discloses an apparatus which thrusts a casing into a pilot hole, with a bit leading the casing. However, while such forward thrust techniques are useful for unidirectional application such as the introduction of conduits into the ocean, such methods place significant stress on the conduit itself, and also present relatively slow installation rates. The pull-back methods described hereinabove and hereinbelow are preferable from the standpoint of reduced stress on the casing, as well as increased installation rates.
A method and apparatus for removing cuttings is described in U.S. Pat. No. 5,096,002 to Cherrington, issued Mar. 17, 1992, entitled "Method and Apparatus for Enlarging an Underground Path" which is incorporated by reference herein. While the device described in U.S. Pat. No. 5,096,002 is effective in removing the cuttings, it relies on several moving parts, which may decrease its reliability.
Therefore, a need has arisen in the industry for a method and apparatus for removing cuttings from a bore hole with a reduced number of working parts.
SUMMARY OF THE INVENTION
In accordance with the present invention, a method and apparatus for removing drilling mud with entrained cuttings is provided which substantially prevents disadvantages associated with the prior art.
In the present invention, a pump is provided for forcing a fluid into a borehole, such that the fluid mixes with the cuttings from the hole. A pipe receives the fluid and entrained cuttings at a first end of the pipe and returns the fluid and entrained cuttings to the surface at the second end of the pipe. At the first end of the pipe, air is injected into the drilling fluid with entrained cuttings to form bubbles therein, thereby increasing the velocity of the fluid and entrained cuttings through the pipe.
In a second embodiment of the invention, a suction is provided at one end of the pipe to increase the speed of the fluid and entrained cuttings therethrough.
In a third embodiment of the present invention, an Archimedes screw is used to remove the fluid and entrained cuttings from the borehole.
The present invention provides significant advantages over the prior art. The air may be injected into the drilling mud (or other drilling fluid) without significantly increasing cost or complexity of the drilling operations. The injected air forms bubbles which significantly increase the flow of the drilling mud to the surface.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIGS. 1 and 2 are cross-sectional drawings showing an apparatus for reaming and installing a conduit according to the prior art;
FIGS. 3a-3b are side views of a device for drilling a borehole with a stationary casing and removing cuttings therefrom using air bubbles to enhance removal of the cuttings;
FIGS. 4a-4b illustrate side views of a device for drilling a borehole with a rotating casing and removing cuttings therefrom using air bubbles to enhance removal of the cuttings;
FIG. 4c illustrates a device for removing cuttings from an existing borehole using air bubbles to enhance the removal of the cuttings;
FIGS. 5a-5b illustrate side views of a device for creating a borehole with a stationary casing and removing cuttings therefrom using suction to enhance removal of the cuttings;
FIGS. 6a-6b illustrate side views of a device for creating a borehole with a rotating casing and removing cuttings therefrom using suction to enhance removal of the cuttings; and
FIGS. 7a-7b illustrate side views of a device for creating a borehole and removing cuttings therefrom using an Archimedes screw.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the present invention and its advantages are best understood by referring to FIGS. 3-7 of the drawings, like numerals being used for like and corresponding parts of the various drawings.
FIG. 3 illustrates a side view of a first embodiment of a device for creating a borehole and removing cuttings therefrom. A pilot borehole 100 is drilled underneath a river 102 or other surface obstacle. A working drill string 104 and a trailing drill string 106 are coupled to the hole opener (or "reamer") 108. As the hole opener is pulled through the pilot hole 100, an enlarged borehole 110 is formed. A stationary casing 112 is positioned within the enlarged borehole 110. A diffuser 114 is connected to the stationary casing 112 and to an air compressor 116 via air pipe 118. The stationary casing 112 terminates in a stuffing box 120 (also known as a "packing gland") through which the trailing drill string 106 is disposed. The stuffing box 120 is coupled to a discharge line 122 which expels the drilling fluid and entrained cuttings into a solids control device 124 for purifying the drilling mud. The drilling mud output from the solids control device 124 is pumped into the trailing drill string 106 via high pressure mud line 126 and pressure mud swivel 127 and is also pumped into the enlarged borehole 110 via mud pump discharge line 128 using mud pump 130. Drill rig 132 is coupled to the working drill string 104.
Briefly, the operation of the reamer/hole cleaning device is as follows. After forming the pilot hole 100, the hole enlarger 108 is rotated by drill rig 132 to form enlarged borehole 110. During rotation of the hole opener 108, drilling mud, or other drilling fluid, is forced through trailing drill string 106 to emerge at the face of hole opener 108 carry the cuttings away from the hole opener 108 during reaming operations. As the hole opener 108 forms the enlarged hole, cuttings 134 are formed which mix with the drilling mud in the enlarged hole. Drilling mud is also fed directly into the enlarged hole through mud pump discharge line 128. The drilling mud and entrained cuttings return via the path formed between the stationary casing 112 and the trailing drill string 106 and are transported via discharge line 122 to the solids control device 124 which removes solids from the drilling mud and returns the recycled drilling mud to the enlarged borehole 110.
Importantly, the air compressor 116 forces air into the stationary casing 112 via diffuser 114 which causes air bubbles to be mixed with the drilling fluid and entrained cuttings. As the mixture of drilling mud and cuttings 134 enter the stationary casing 112, the air bubbles expand creating a higher velocity of mud through the stationary casing. It is believed the air bubbles lower the pressure of the mud within the stationary casing, thereby increasing the velocity of the mud.
The flow of mud through the stationary casing is shown in greater detail in connection with FIG. 3b. As shown in FIG. 3a, trailing drill string 106 is disposed within stationary casing 112, forming a channel 136 through which the drilling mud and cuttings may be transported to the surface. The trailing drill string 106 is coupled to reamer 108 such that drilling mud transported through the trailing drill string 106 is output from the reamer 108 for lubrication during reaming operations. Stuffing box 120 includes a seal 138 for allowing rotation of the trailing drill string 106 while preventing the returning drilling mud/cuttings from exiting at the point of rotation.
Diffuser 114 is disposed circumferentially about the stationary casing 112. The diffuser 114 receives compressed air via air pipe 118. The air is forced into the channel 136 through perforations 139 where bubbles 140 are formed in the drilling mud. The bubbles 140 increase the velocity of the drilling mud/cuttings through the channel 136.
FIGS. 4a-b illustrate a second embodiment wherein air bubbles are used to increase the velocity of the drilling mud/cuttings. In this embodiment, a rotating or non-rotating trailing drill casing 140 is coupled to hole opener 108. The trailing casing 140 includes an intake sub 142 having holes 144. Air compressor 116 is coupled to a stationary air pipe 146 which terminates within the trailing casing 140 at diffuser head 148. Stationary air pipe 146 is coupled to trailing casing 140 through air pipe packing gland 149. Diffuser head 148 includes a plurality of perforations 150 through which the compressed air from air compressor 116 may flow. Mud pump 130 is coupled to working drill string 104 through drill rig 132. If a non-rotating trailing drill casing 140 is used, a swivel joint should be provided so that the working drill 104 does not need to turn the trailing drill casing. For illustration, it will be assumed herein that trailing drill casing is a rotating casing.
In operation, drilling mud is provided to the hole opener 108 through the working drill string 104. Drilling mud is also forced into the enlarged hole by solids control device 124. The mud combines with cuttings from the reaming operation, which enter rotating casing 140 through the holes 144 in intake sub 142. Stationary air pipe 146 receives compressed air from air compressor 116, and outputs the compressed air through the perforations 150 of diffuser head 148. As described above, the air forms bubbles in the combination drilling mud/cuttings and increases its velocity to the surface in the rotating trailing casing 140. The aerated drilling mud/cutting mixture emerges from the rotating trailing casing 140 through discharge line 122 to the solids control device 124.
This embodiment of the invention provides the advantage of drawing the drilling mud/cuttings mixture into the rotating trailing casing 140 at the point of reaming. Hence, the cuttings can be drawn into the rotating trailing casing 140 before they have a chance to settle at the bottom of the enlarged hole. In order to increase the draw into the intake sub 142, a jet pump may be used wherein a high velocity stream of drilling mud is generated approximate the intake sub to create a pressure differential which draws the drilling mud/cuttings into the trailing casing 140. Jet pumps are discussed in greater detail in connection with U.S. Pat. No. 5,269,384, filed Nov. 8, 1991, entitled "Method and Apparatus for Cleaning a Borehole" to Cherrington, which is incorporated by reference herein.
FIG. 4c illustrates an embodiment of the invention used to remove cuttings from an enlarged hole after the reaming apparatus has been removed. This embodiment is similar to the embodiment shown in FIGS. 4a-b, except head 152 is rotated within the enlarged hole to receive the mud/cuttings from the enlarged hole through holes 153. As described above, suction into the head 152 may be generated by a jet pump, as described in U.S. Pat. No. 5,269,384, referenced above.
FIGS. 5a-b illustrate an embodiment similar to the device shown in FIGS. 3a-b, with the exception that suction is used to increase the flow of the drilling mud/cuttings through the stationary casing 112. In this embodiment, a vacuum pump 154 is coupled to the discharge line 156 which conveys the drilling mud/cuttings from the stationary casing 112. The vacuum pump 154 creates a suction which pulls the drilling mud/cuttings through the stationary casing and outputs the drilling mud/cuttings to the solids control device 124 via the discharge line 122.
The operation of the device shown in FIGS. 5a-b is similar to the device shown in FIGS. 3a-b. Drilling mud is output to the enlarged hole 110 via the mud pump discharge line 28 and to the hole enlarger 108 via the trailing drill string 106. As the reaming operations are performed under power of the drill rig 132 and working drill string 104, cuttings become mixed with the drilling fluid and are drawn into the stationary casing 112 by the suction pump 154.
To further increase the flow of the drilling mud/cuttings through the stationary casing, the compressed air method shown in FIG. 3a could be combined with the suction method shown in FIG. 5a.
FIGS. 6a-b illustrate a second embodiment of a reaming/cleaner which uses suction through a rotating (or non-rotating) trailing casing, similar to the device shown in connection with FIGS. 4a-b. This embodiment is structurally similar to the structure shown in FIGS. 4a-b, except that a vacuum pump 154 is coupled to the rotating casing 140 in order to draw the drilling mud/cuttings from the rotating casing. While the air compressor 116 of FIG. 4a is not used in the illustrated embodiment of FIGS. 6a-b, however, both the air compressor 116 and the vacuum pump 154 may be used in conjunction to increase the flow of the drilling mud/cuttings through the rotating trailing casing 140.
In operation, drilling mud is provided through the working drill string 104 to the hole opener 108. Additionally, drilling mud is provided by the solids control unit 124 to the enlarged borehole 110. During the reaming operation, cuttings become mixed with the drilling mud and are drawn into the rotating casing 140 through holes 144 of intake sub 142. The drilling mud/cuttings are removed by the vacuum pump 154 to the solids control unit 124 via discharge line 122.
As previously described in connection with FIG. 4c, the device shown in FIGS. 6a-b can be designed as a hole cleaner (without the reamer) to remove cuttings from an already enlarged borehole.
FIGS. 7a-b illustrate another embodiment of a reamer/hole cleaner which uses positive displacement to create a suction to remove the drilling mud/cuttings from the enlarged borehole. A structure shown in FIGS. 7a-b is similar to that shown in FIG. 6a, except an Archimedes screw 158 is used to remove mud/cuttings from the rotating (or non-rotating) casing 140. The Archimedes's screw is disposed within rotating casing 140 and powered by rotary drive 160. As cuttings are transported up the Archimedes's screw 158, a suction results which draws more drilling mud/cuttings into the holes 144 of intake sub 142.
This embodiment has the advantage that the flow of drilling mud/cuttings through the rotating casing 140 is very controllable.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
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A method and apparatus for removing drilling mud within entrained cuttings is provided using a pump for forcing fluid into a borehole, such that the fluid mixes with cuttings formed during the formation of the hole. The pipe receives the fluid and entrained cuttings at a first end of the pipe and returns the fluid and entrained cuttings to the surface at the second end of the pipe. At the first end of the pipe, air is injected into the drilling fluid with entrained cuttings to form bubbles therein, thereby increasing the velocity of the fluid and entrained cuttings through the pipe. In one alternative embodiment, a suction is provided at one end of the pipe to increase the speed of fluid and entrained cuttings therethrough. In a third embodiment of the present invention, an Archimedes screw is used to remove the fluid and entrained cuttings from the borehole.
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FIELD OF THE INVENTION
[0001] This invention pertains to instrument systems and methods for positioning the body, or a portion of the body, of a surgical subject (or other “body” as defined herein) at a predetermined three-dimensional position in space. The systems and methods have especial utility for surgery, diagnostic intervention, and research involving the subject's brain or other anatomical structure located in the interior of the subject's body, wherein the brain or other anatomical structure has a buried locus of interest that normally is obscured by overlying structure.
BACKGROUND OF THE INVENTION
[0002] In research and surgery of animals including small animals such as rats and mice, it can be extremely difficult to locate a terminus of a probe, electrode, micropipette, or other implement (herein generally termed a “probe”) at a particular location within the subject's body without having to remove overlying structure and the like to permit direct observation of placement of the probe. This problem is especially critical in brain research involving the placement of a probe at a desired locus deep within a living subject's brain inside the surrounding skull.
[0003] To aid researchers in locating various anatomical structures in the brains of research animals such as mice, rats, cats, dogs, and primates, respective so-called brain atlases are often consulted. A brain atlas provides three-dimensional coordinates for the structures, normally using a Cartesian (rectangular) coordinate system, relative to one or more accessible anatomical features. (For example, for mice and rats, the usual reference feature on the skull is bregma, which is a point of meeting of the coronal and sagittal sutures. A second reference feature that is sometimes used in connection with bregma is lambda, which is located posteriorly of bregma and is a point of meeting of the lambdoidal and sagittal sutures. The sagittal suture connecting bregma and lambda is regarded generally as representing a sagittal mid-line of the skull.) However, despite the existence of such information, current apparatus and methods used to place an introduced probe are notoriously inaccurate with individual subjects and from one subject to another in a population of subjects. Such inaccuracy is a substantial problem because it results in unintentionally mis-positioned probes and other tools, which causes misleading research data and wasted animal resources.
[0004] Stereotaxic apparatus are known in the art for positioning a subject's head for brain research. For a small animal such as a mouse or rat, the head is held immobile by externally applied structures such as ear bars and a nose clamp providing a “three-point” holding system. As an example, reference is made to U.S. Pat. No. 5,601,570 to Altmann et al.
[0005] All known prior-art apparatus have various substantial shortcomings. For example, the Altmann et al. apparatus is inherently incapable of positioning a subject's head, in three-dimensional space, in a manner providing a high level of confidence that a probe inserted from outside the skull will “hit” a desired locus within the brain. More specifically, the Altmann et al. apparatus does not allow the researcher, intending to probe a living brain of a research animal, to position a particular animal's head in a manner providing reliably accurate insertion and placement of the probe to desired three-dimensional coordinates in the brain. The Altmann apparatus also exhibits poor precision of placements of a probe at a desired locus in each animal in a population of animals. Consequently, the researcher must conduct a series of “pilot” studies, followed by histological confirmations, to compare actual probe results with desired results (e.g., to compare actual hit loci with desired hit loci based on information in a brain atlas). Such studies using conventional apparatus usually produce data exhibiting wide variations that often are attributed wrongly to biological variations among individual animals in a population, strains, ages of animals, and so on. As the pilot studies progress, the coordinates provided by a conventional apparatus are adjusted gradually to compensate for the variation and to improve the hit rate. Unfortunately, such studies are time-consuming and costly to perform, and require substantially increased numbers of animals to conduct a particular experiment. Conventional instruments simply do not allow the researcher to differentiate between the many sources of error. Furthermore, even with adjustments to the apparatus based on the pilot studies, hit rates remain disappointingly low, resulting in inconclusive research.
[0006] As noted above, individual animals (even of the same strain) exhibit substantial variation, one animal to the next, in morphology of body structures such as the skull. If positioning of the body or body structure is guided, according to the prior art, solely on the basis of external features (e.g., positions of ear holes relative to each other and to the snout), this variation usually results in excessive variation in probe placement at target loci within the brain.
SUMMARY OF THE INVENTION
[0007] In view of the shortcomings of the prior art summarized above, the present invention provides, inter alia, apparatus and methods for positioning the body, or portion of the body (such as the skull and its contents), of a research subject accurately in three-dimensional space. (As used herein, the term “body” can be an entire body such as an entire mouse or rat, or a portion of an entire body.) To achieve such positioning, the body is held in a holder configured to hold the body immobile in a desired position. The holder, in turn, is mounted in a manner allowing any of various motions in three-dimensional space required to achieve the desired positioning.
[0008] According to a first aspect of the invention, stereotaxic holders are provided for holding a body at a position in three-dimensional space. A representative embodiment of such a holder comprises a frame, an X-axis shift mechanism, a Y-axis shift mechanism, and a Z-axis shift mechanism (wherein the terms “X-axis,” “Y-axis,” and “Z-axis” refer to the orthogonal axes in a Cartesian coordinate system. A body-holding component, configured to contact a body, can be attached to the frame such that the body-holding component extends from the frame to contact the body and hold the body relative to the frame. The frame is attached to the X-axis, Y-axis, and Z-axis shift mechanisms. The X-axis shift mechanism is configured to move the frame, with body-holding component, along an X-axis. The Y-axis shift mechanism is configured to move the frame, with body-holding component, along a Y-axis, wherein the movement along the Y-axis is independent of the movement along the X-axis. The Z-axis shift mechanism is configured to move the frame, with body-holding component, along a Z-axis, wherein the movement along the Z-axis is independent of the movement along the X-axis or along the Y-axis. The shift mechanisms are configured relative to each other so as to define a reference X-axis, a reference Y-axis, and a reference Z-axis, respectively, that are orthogonal relative to each other and that mutually intersect at a 0,0,0 point in three-dimensional space. The X-axis shift mechanism, Y-axis shift mechanism, and Z-axis shift mechanism are configured to move a body, mounted to the frame by the body-holding component, as required to place a selected point on or in the body at the 0,0,0 point.
[0009] The stereotaxic holder as summarized above can further comprise one or more of an X-axis tilting mechanism, a Y-axis tilting mechanism, and a Z-axis tilting mechanism. The X-axis tilting mechanism is configured to tilt a body, held by the frame, about the reference X-axis and relative to the 0,0,0 point. The Y-axis tilting mechanism is configured to tilt a body, held by the frame, about the reference Y-axis and relative to the 0,0,0 point. The Z-axis tilting mechanism is configured to tilt a body, held by the frame, about the reference Z-axis and relative to the 0,0,0 point. Each tilting motion is independent of any other tilting motion of the body or of any shifting motion of the frame as achieved by the stereotaxic holder.
[0010] The stereotaxic holder can further comprise at least one body-holding component attached to the frame. Exemplary body-holding components include, but are not limited to, ear bars and snout adapters.
[0011] In an example embodiment of a stereotaxic holder according to the invention, the frame is attached to the Z-axis shifting mechanism, the Z-axis shifting mechanism is attached to the X-axis shifting mechanism, and the X-axis shifting mechanism is attached to the Y-axis shifting mechanism. The example embodiment can further comprise a plate, wherein the X-axis tilting mechanism is attached to the plate. Hence, the Y-axis shifting mechanism is attached to the X-axis tilting mechanism, the Y-axis tilting mechanism is attached to the Y-axis shifting mechanism, the X-axis shifting mechanism is attached to the Y-axis tilting mechanism, and the Z-axis shifting mechanism is attached to the X-axis shifting mechanism. The plate can be mounted pivotably to a sub-plate to allow the plate to swing about the reference Z-axis. In such a configuration, the plate and sub-plate comprise the Z-axis tilting mechanism.
[0012] A second representative embodiment of a stereotaxic holder according to the invention comprises a first U-frame, a Z-axis shifting mechanism, an X-axis shifting mechanism, a Y-axis shifting mechanism, a Y-axis tilting mechanism, an X-axis tilting mechanism, and a Z-axis swing mechanism. A body-holding component, as summarized above, is attached to the first U-frame. The first U-frame is attached to the Z-axis shifting mechanism, which is configured to move the first U-frame, with body-holding component, along a Z-axis. The Z-axis shifting mechanism is attached to the X-axis shifting mechanism, which is configured to move the Z-axis shifting mechanism and first U-frame along an X-axis. The X-axis shifting mechanism is attached to the Y-axis shifting mechanism, which is configured to move the X-axis shifting mechanism, Z-axis shifting mechanism, and first U-frame along a Y-axis. The Y-axis tilting mechanism connects the X-axis shifting mechanism to the Y-axis shifting mechanism. The Y-axis tilting mechanism defines a reference Y-axis about which the Y-axis tilting mechanism effects tilting of the body. The Y-axis tilting mechanism is attached to the X-axis tilting mechanism, and the X-axis tilting mechanism is attached to the Z-axis swing mechanism. The X-axis tilting mechanism defines a reference X-axis about which the X-axis tilting mechanism effects tilting of the body, and the Z-axis swing mechanism defines a reference Z-axis about which the Z-axis swing mechanism effects a swing of the body. The reference X-axis, reference Y-axis, and reference Z-axis are orthogonal to each other and mutually intersect at a 0,0,0 point in three-dimensional space.
[0013] In the second representative embodiment as summarized above, the X-axis tilting mechanism can comprise a second U-frame having ends that pivot about the reference X-axis, and a base to which the Y-axis shifting mechanism is attached. In such a configuration, the Z-axis swing mechanism can comprise a plate and a sub-plate, wherein the X-axis tilting mechanism is attached to the plate and the plate is attached pivotably to the sub-plate to allow the plate to swing about the reference Z-axis.
[0014] According to another aspect of the invention, stereotaxic alignment systems are provided. A representative embodiment of such a system comprises a base plate and any of various stereotaxic holders according to the invention. For example, the stereotaxic holder can be configured as summarized above with respect to the first representative embodiment. In such a configuration, the stereotaxic holder can further comprise at least one of (desirably all three of) a X-axis tilting mechanism, a Y-axis tilting mechanism, and a Z-axis tilting mechanism. Each tilting mechanism, if present, is configured to tilt a body, held by the frame, about the respective reference axis and relative to the 0,0,0 point independently of any other tilting motion of the body or of any shifting motion of the frame.
[0015] In a stereotaxic alignment system according to the invention, the stereotaxic holder can include a centering gauge indicating the 0,0,0 point. For example, the centering gauge can be situated on the terminal face of a gauge post attached to the stereotaxic holder such that the gauge post is coaxial with the reference Z-axis.
[0016] Another representative embodiment of a stereotaxic alignment system according to the invention comprises a base plate, a stereotaxic holder (as summarized above) mounted to the base plate, and a manipulator mounted to the base plate. The manipulator includes a “controlled end” to which an implement can be mounted. Thus, the manipulator can present to the body a tool, held by the manipulator, at a desired locus on or in the body relative to the 0,0,0 point.
[0017] The manipulator desirably comprises an X-axis shifting mechanism, a Y-axis shifting mechanism, and a Z-axis shifting mechanism for shifting the controlled end along an X-axis, Y-axis, and Z-axis, respectively, relative to the 0,0,0 point. The manipulator further comprises a three-axis universal joint to which the X-axis shifting mechanism, the Y-axis shifting mechanism, and Z-axis shifting mechanism are mounted. The universal joint desirably is configured to allow adjustment of an orthogonal relationship of the X-axis, Y-axis, and Z-axis of the manipulator relative to each other. The universal joint can be configured further to allow adjustment of one or more of the X-axis, Y-axis, and Z-axis of the manipulator with one or more of the reference X-axis, reference Y-axis, and reference Z-axis of the stereotaxic holder.
[0018] In a stereotaxic alignment system according to the invention, the manipulator can include an implement mounted to the controlled end of the manipulator. Desirably, any of various implements has an alignment axis (usually the longitudinal axis of the implement). Desirably, any implement attachable to the controlled end is “self-indexing” as defined herein.
[0019] An exemplary implement is a centering scope usable with a centering gauge, as summarized above, that indicates the 0,0,0 point. The centering scope has an optical axis that is coincident with the alignment axis. In such an arrangement, the manipulator is configured to position the centering scope in an adjustable manner such that the optical axis intersects the centering gauge at the 0,0,0 point.
[0020] Other exemplary implements include, but are not limited to, drilling units, syringe holders, dial test indicators, cannula-insertion devices, and a stereotaxic alignment indicators.
[0021] According to another aspect of the invention, methods are provided for performing a stereotaxic alignment of a body. According to a representative embodiment of such a method, a reference X-axis, a reference Y-axis, and a reference Z-axis are provided that are orthogonal to each other and that mutually intersect at a 0,0,0 point in three-dimensional space. The body is mounted in a holder configured to effect respective controlled shifts of the body in an X-axis direction, a Y-axis direction, and a Z-axis direction, and to effect respective controlled tilts of the body about the reference X-axis and reference Y-axis, as well as controlled swings of the body about the reference Z-axis. Using the holder, the body is shifted as required in the X-axis, Y-axis, and Z-axis dimensions to place a selected target point on or in the body at the 0,0,0 point. Further using the holder, the body is subjected to a swinging motion as required about the reference Z-axis while maintaining the target point at the 0,0,0 point, to obtain a desired orientation of the body relative to the reference Y-axis or the reference X-axis. Further using the holder, the body is tilted as required about the reference Y-axis while maintaining the target point at the 0,0,0 point, so as to obtain a desired orientation of the body relative to the reference X-axis. Further using the holder, the body is tilted as required about the reference X-axis while maintaining the target point at the 0,0,0 point, so as to obtain a desired orientation of the body relative to the reference Y-axis. The step of swinging the body about the reference Z-axis can comprise the steps of: (1) identifying a first reference point and a second reference point on or in the body, wherein the first and second reference points define a reference line; and (2) swinging the body as required about the reference Z-axis until the reference line is at a desired orientation relative to the reference X-axis or the reference Y-axis. The reference line can be, for example, a sagittal axis of the body, wherein placing the reference line at the desired orientation achieves a sagittal alignment of the body.
[0022] The step of tilting the body about the reference Y-axis can comprise the steps of: (1) providing a stereotaxic alignment indicator for ascertaining the orientation of the body relative to the reference X-axis; (2) placing the stereotaxic alignment indicator into functional contact with the body; and (3) tilting the body as required until the stereotaxic alignment indicator indicates the desired orientation of the body about the reference Y-axis relative to the reference X-axis. For example, the body can be aligned to have its sagittal axis aligned with the reference Y-axis, wherein obtaining the desired orientation of the body about the reference Y-axis places the body at a desired coronal tilt.
[0023] The step of tilting the body about the reference X-axis can comprise the steps of: (1) providing a stereotaxic alignment indicator for ascertaining the orientation of the body relative to the reference Y-axis; (2) placing the stereotaxic alignment indicator into functional contact with the body; and (3) tilting the body as required until the stereotaxic alignment indicator indicates the desired orientation of the body about the reference X-axis relative to the reference Y-axis. For example, the body can be aligned to have its sagittal axis aligned with the reference Y-axis, wherein obtaining the desired orientation of the body about the reference X-axis places the body at a desired dorsal tilt.
[0024] The foregoing and additional features and advantages of the invention will be more apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1( a ) is an oblique rear view of a representative stereotaxic holder, according to the invention, including a snout adapter and ear bars for holding a rodent skull.
[0026] [0026]FIG. 1( b ) is an oblique front view of the FIG. 1( a ) embodiment, including a snout adapter and ear bars for holding a rodent skull.
[0027] [0027]FIG. 1( c ) is an oblique front view of the FIG. 1( a ) embodiment, but with the snout adapter and ear bars removed and a gauge post attached.
[0028] [0028]FIG. 2 is an oblique front view of the stereotaxic holder embodiment of FIG. 1( a ) attached to a base.
[0029] [0029]FIG. 3 is an oblique front view of a representative embodiment of a stereotaxic alignment system according to the invention, the system including the FIG. 2 embodiment including a manipulator attached to the base and a centering scope attached to the manipulator.
[0030] [0030]FIG. 4 is an enlarged oblique front view of a representative embodiment of a manipulator that can be included with a stereotaxic alignment system according to the invention. The FIG. 4 manipulator is substantially the same as shown in FIG. 3.
[0031] [0031]FIG. 5 shows details of a centering scope as a first representative implement that can be mounted to a manipulator of a stereotaxic alignment system according to the invention.
[0032] [0032]FIG. 6 shows details of a drilling unit as a second representative implement that can be mounted to a manipulator of a stereotaxic alignment system according to the invention.
[0033] [0033]FIG. 7 shows details of a syringe holder as a third representative implement that can be mounted to a manipulator of a stereotaxic alignment system according to the invention.
[0034] [0034]FIG. 8 shows details of a dial test indicator as a fourth representative implement that can be mounted to a manipulator of a stereotaxic alignment system according to the invention.
[0035] [0035]FIG. 9 shows details of a first representative embodiment of a cannula-insertion device as yet another example implement that can be mounted to a manipulator of a stereotaxic alignment system according to the invention.
[0036] [0036]FIG. 10 shows details of a second representative embodiment of a cannula-insertion device as yet another example implement that can be mounted to a manipulator of a stereotaxic alignment system according to the invention.
[0037] [0037]FIG. 11 shows details of a third representative embodiment of a cannula-insertion device as yet another example implement that can be mounted to a manipulator of a stereotaxic alignment system according to the invention.
[0038] [0038]FIG. 12 depicts a cannula adapter, for use in the FIG. 11 embodiment of a cannula-insertion device, placed in a gauge block 900 used for facilitating auto-indexing of a cannula or other tool held by the cannula adapter when mounted to the cannula-insertion device.
[0039] [0039]FIG. 13 shows details of a representative embodiment of a stereotaxic alignment indicator as yet another example implement that can be mounted to a manipulator of a stereotaxic alignment system according to the invention.
[0040] [0040]FIG. 14( a ) is a front oblique view similar to FIG. 3, but in which a stereotaxic alignment indicator (such as shown in FIG. 13) is mounted to the manipulator rather than the centering scope. The stereotaxic manipulator is oriented to perform a determination of tilt of the subject body about a Y-axis.
[0041] [0041]FIG. 14 is a front oblique view similar to FIG. 14( a ), but in which the stereotaxic alignment indicator is oriented to perform a determination of tilt of the subject body about an X-axis.
[0042] [0042]FIG. 15 is a front oblique view of a representative embodiment of a snout adapter that can be mounted to a stereotaxic holder according to the invention.
DETAILED DESCRIPTION
[0043] To better understand the various motions of a body achievable using an apparatus according to the invention, the following information is useful. (When reviewing this information, it is helpful to envision a human body standing on its feet and facing straight ahead.) A median plane is a vertical plane that divides the body lengthwise into right and left halves. This plane is also termed a sagittal plane (because in a standing human it passes approximately through the sagittal suture in the skull), but actually any plane parallel to the medial plane is also termed a sagittal plane. A sagittal line or axis is a line on the sagittal plane extending lengthwise with respect to the subject's body (with a skull, such a line would extend roughly parallel to at least a portion of the sagittal suture). The coronal plane is a vertical plane that is perpendicular to the sagittal plane. (The coronal plane is so termed because in a standing human it passes approximately through the coronal suture in the skull). Thus, the coronal plane divides the body into a front (ventral) half and a rear (dorsal) half. A coronal line or axis is a line in the coronal plane extending widthwise with respect to the subject's body (with a skull, such a line would extend roughly parallel to at least a portion of the coronal suture). A transverse plane is perpendicular to the sagittal and coronal planes. Ventral refers to the front (or belly surface) of the subject, and dorsal refers to the rear (or back surface) of the subject. Ventral and dorsal are synonymous with anterior and posterior, respectively.
[0044] A representative embodiment of a stereotaxic alignment system according to the invention comprises a stereotaxic holder 10 (such as the embodiment shown in FIGS. 1 ( a ) and 1 ( b ) and described below). For improved stability, the stereotaxic holder 10 desirably is mounted on a heavy base such as shown in FIG. 2.
[0045] The embodiment of FIGS. 1 ( a ) and 1 ( b ) is adapted especially for mounting and positioning of the head of a surgical or diagnostic subject (e.g., a rodent) in three-dimensional space to a reference position, and for rotating the subject's head into a desired three-dimensional position or stereotaxic plane. To such end, the stereotaxic holder comprises multiple slide mechanisms for controlled movement and placement of the subject's head in all three Cartesian dimensions. However, it readily will be appreciated that the relative dimensions of components of this embodiment can be changed to enable the apparatus to accommodate any size or configuration of body or body structure to be held by it.
[0046] A subject “body” (which can be a portion of an actual body) is held using components conveniently mounted to a first U-frame 12 . The first U-frame 12 includes a center portion (base) 14 and first and second arms 16 , 18 , respectively. As discussed later, to the center portion 14 can be attached, for example, an appropriate snout adapter for holding the anterior end of a rodent skull. Each arm 16 , 18 of the first U-frame 12 terminates with a respective ear bar 20 , 22 , respectively. The ear bars 20 , 22 extend from the respective arms 16 , 18 toward each other to engage the respective ear openings in the subject's skull. For ease of mounting the skull to the first U-frame 12 , the spacing between the ear bars 20 , 22 desirably is adjustable by loosening knurled screws 24 , 26 , sliding the ear bars 20 , 22 toward or away from each other (a scale 25 on each ear bar 20 , 22 can be used as a guide), and then tightening the knurled screws 24 , 26 .
[0047] It readily will be appreciated that the ear bars 20 , 22 can be replaced with any of various other grasping, centering, or holding implements especially configured to engage a particular corresponding physical feature of a subject body to be held by the stereotaxic holder 10 .
[0048] The first U-frame 12 is supported by an assembly of slide (or “shift”) mechanisms that collectively allow positioning motions of the first U-frame 12 (and thus a skull or other body held by the first U-frame) linearly along the three Cartesian axes (X-, Y-, and Z-axis). Briefly, referring to FIG. 1( a ), a Z-axis shift mechanism 28 provides shift motion of the first U-frame 12 along the indicated Z-axis; an X-axis shift mechanism 30 provides shift motion of the first U-frame 12 along the indicated X-axis; and a Y-axis shift mechanism 32 provides shift motion of the first U-frame 12 along the indicated Y-axis. Motion along the Z-axis is achieved by turning the knurled knob 34 that actuates the Z-axis shift mechanism 28 . Motion along the X-axis is achieved by turning the knurled knob 36 that actuates the X-axis shift mechanism 30 . Motion along the Y-axis is achieved by turning the knurled knob 38 that actuates the Y-axis shift mechanism 32 .
[0049] Whereas, in the embodiment of FIGS. 1 ( a ) and 1 ( b ), the knurled knobs 34 , 36 , 38 are adapted especially for manual turning, it is contemplated that such turnings can be made using, by way of example, any of various wheels, cranks, levers, or motors. Also, whereas the depicted embodiment utilizes slide mechanisms each employing parallel guide bars and a lead screw, as described below, it readily will be apparent that any of various other linear displacement mechanisms can be employed, such as (but not limited to) dovetail slides and linear ball slides.
[0050] In more detail, the base 14 of the first U-frame 12 is attached to the Z-axis shift mechanism 28 . The Z-axis shift mechanism 28 comprises two parallel bushings 42 , 44 or linear bearings (generally termed “bushings”) mounted in the base 14 of the first U-frame 12 . Respective parallel guide bars 46 , 48 are inserted into the bushings 42 , 44 and extend to respective arms 51 , 53 of a first T-member 50 to which the guide bars are affixed. A lead screw 52 , attached to the knurled knob 34 , extends through the first T-member 50 , and is threaded into the base 14 of the first U-frame 12 . Thus, turning the knurled knob 34 causes shift motion (along the Z-axis) of the first U-frame 12 along the guide bars 46 , 48 relative to the first T-member 50 .
[0051] Turning now to the X-axis shift mechanism 30 , two parallel bushings 54 , 56 or linear bearings (generally termed “bushings”) are mounted in the stem 58 of the first T-member 50 . Respective parallel guide bars 60 , 62 are inserted into the bushings 54 , 56 and extend to opposing arms 64 , 66 of a second U-frame 68 to which the guide bars 60 , 62 are affixed. A lead screw 70 is attached to the knurled knob 36 , extends through one arm 64 of the second U-frame 68 , is threaded into the stem 58 of the first T-member 50 , and is journaled in the second arm 66 of the second U-frame 68 . Thus, turning the knurled knob 36 causes shift motion (along the X-axis) of the first T-member 50 (with attached first U-frame 12 ) along the guide bars 60 , 62 relative to the second U-frame 68 .
[0052] Turning now to the Y-axis shift mechanism 32 , two parallel bushings 72 , 74 or linear bearings (generally termed “bushings”) are mounted in the base 90 of a third U-frame 76 . Respective parallel guide bars 78 , 80 are inserted into the bushings 72 , 74 and extend to respective arms 82 , 84 of a second T-member 86 to which the guide bars 78 , 80 are affixed. A lead screw 88 is attached to the knurled knob 38 , extends through the second T-member 86 , and is threaded into the base 90 of the third U-frame 76 . Thus, turning the knurled knob 38 causes shift motion (along the Y-axis) of the X-axis shift mechanism 30 , the Z-axis shift mechanism 32 , and the first U-frame 12 along the guide bars 78 , 80 relative to the third U-frame 76 .
[0053] In addition to the X-, Y-, and Z-axis shift mechanisms 30 , 32 , 28 , respectively, discussed above for achieving respective linear positioning motions along the three Cartesian axes, the embodiment of FIGS. 1 ( a ) and 1 ( b ) also is configured to effect pivoting (“tilt” and “swing”) motions about each of three Cartesian reference axes.
[0054] The reference Y-axis about which Y-axis tilting motion can be achieved is denoted “PAX Y ” in FIGS. 1 ( a ) and 1 ( b ) and extends through the stem 92 of the second T-member 86 . Specifically, a shaft 94 is attached to the base 96 of the second U-frame 68 and is journaled in the stem 92 of the second T-member 86 . A knurled knob 98 is used to effect rotation of a gear (or analogous means) engaged with the shaft 94 or with the base 96 ; i.e., turning of the knurled knob 98 effects tilting of the second U-frame 68 , Z-axis shift mechanism 28 , and X-axis shift mechanism 30 (and all components attached thereto) about the axis PAX Y . A particular angular position about the axis PAX Y can be “locked” by tightening a cinching screw 100 .
[0055] The reference X-axis about which X-axis tilting motion can be achieved is denoted “PAX X ” in FIGS. 1 ( a ) and 1 ( b ). The axis PAX X extends through the termini of the arms 102 , 104 of the third U-frame 76 . Specifically, the arms 102 , 104 are attached via respective shafts 106 , 108 to respective blocks 110 , 112 allowing tilting motion of the third U-frame 76 (including all components attached thereto) about the axis PAX X . To achieve such tilting motion in a controllable manner, a respective block or other suitable member 114 , 116 is attached rotatably to each arm 102 , 104 of the third U-frame 76 . (The figure shows such attachment at about the midline of each arm 102 , 104 , but such a configuration is not limiting in any way.) Threaded through one block 114 is a lead screw 118 terminating with a knurled knob 120 , and extending through the other block 116 is a guide bar 122 . The lead screw 118 is affixed rotatably to a respective member 124 that, in turn, is journaled in a respective block 126 or other suitable member. Similarly, the guide bar 122 is affixed to a respective member 128 that, in turn, is journaled in a respective block 130 or other suitable member. The blocks 126 , 130 are affixed to a plate 132 to which the blocks 110 , 112 are also attached. Thus, turning the knurled knob 120 effects tilting motion of the third U-frame 76 relative to the plate 132 about the axis PAX X . After attaining a desired position of the third U-frame 76 , a cinching screw 131 can be tightened onto the guide bar 122 .
[0056] The reference Z-axis about which Z-axis pivoting motion (“swing”) can be achieved is denoted “PAX Z ” in FIGS. 1 ( a ) and 1 ( b ). The axis PAX z extends through the plate 132 into a sub-plate 134 . The plate 132 is attached rotatably to the sub-plate 134 in any suitable manner allowing motion of the plate 132 relative to the sub-plate 134 about the axis PAX Z . Motion of this type in a controlled manner desirably is effected by turning a shaft 136 engaged (e.g., by a gear engagement or tire engagement) with a curved edge 138 of the plate 132 . The shaft 136 is journaled in the sub-plate 134 and terminates with a knurled knob 140 . Thus, turning the knurled knob 140 effects motion (swing) of the plate 132 about the axis PAX Z relative to the sub-plate 134 . The angular orientation of the plate 132 relative to the sub-plate 134 can be ascertained by consulting a protractor scale 142 . The desired angular orientation can be “locked” by tightening a cinching screw 144 .
[0057] [0057]FIG. 1( c ) shows, extending upward along the axis PAX Z , a removable gauge post 146 terminating with a “centering gauge” 148 . The gauge post 146 has a fixed length relative to the plate 132 and is adapted to be mounted on a pad 150 on the plate 132 . Whenever the gauge post 146 is so mounted, it is coaxial with the axis PAX Z , and the axes PAX X and PAX Y pass through and intersect in the center of the centering gauge 148 . The centering gauge 148 includes an appropriate cross-hair reticle or target that indicates the point of intersection of the three axes PAX X , PAX Y , and PAX Z . During operation of the FIG. 1 embodiment, all axes of rotation for aligning the subject's skull (or other body held by the first U-frame 12 ) into the desired stereotaxic plane are focused at this mutual point of intersection. For example, if the FIG. 1 apparatus is used to hold a mouse head, then the point of intersection can be at bregma on the subject skull to establish a center of rotation, at bregma, for all three axes PAX X , PAX Y , PAX Z . The ability of an apparatus according to the invention to establish this focal point of rotation for all three axes is in stark contrast to apparatus according to the prior art in which the focus of rotation is centered about, e.g., the intersection of “ear bar zero” and the medial plane. With a rodent skull, use of bregma as the center of rotation for all three axes is a key advantage in being able, using an apparatus according to the invention, to position a probe very accurately at a locus within the rodent brain that is situated, according to a brain atlas or other reference data, at a specified location relative to bregma or relative to bregma and lambda.
[0058] It will be appreciated readily that the principles of the present invention are not limited to centering on bregma. Rather, any natural or artificial reference point on or in a body can be used. For example, aside from any of various natural anatomical reference points, the reference point actually utilized can be an implanted bead of a substance readily visible using an X-ray, ultrasonic imager, or MRI imager. Furthermore, although the components of any of the various embodiments within the scope of the invention desirably are made of metal (e.g., aluminum alloy) for most applications, some or all the components can be made of any of various other suitable rigid materials. For example, the stereotaxic holder 10 can be made of a rigid polymer that enables the holder to be used with an MRI imager without the stereotaxic holder itself interfering with MRI imaging of the body being held by the stereotaxic holder.
[0059] Depending upon the orientation of the body mounted to the apparatus of FIGS. 1 ( a ) and 1 ( b ), the axis PAX Z can be regarded as a “sagittal-swing axis,” wherein a swing about the axis PAX Z is made as required to achieve sagittal alignment of the subject body. In the case of a rodent skull, sagittal alignment can achieve alignment of the sagittal suture with (parallel to) anterior-posterior motions of a manipulator (described below) usable in conjunction with the embodiment of FIGS. 1 ( a ) and 1 ( b ), wherein bregma and lambda are used as reference points for the alignment. I.e., sagittal alignment under such conditions results in bregma and lambda defining a line extending perpendicularly to the axis PAX X passing through bregma. Under such conditions, the axis PAX X can be regarded as a “dorsal-tilt axis” for aligning (in the context of a rodent skull) the sagittal suture exactly perpendicularly (or at another pre-determined angular orientation) relative to vertical motions of the manipulator. In other words, nose-up or nose-down tilts are made as required to align lambda with bregma horizontally (with the axis of rotation, PAX X , passing horizontally through bregma and being parallel with lateral motions of the manipulator). Finally, under such conditions, the axis PAX Y can be regarded as a “coronal-tilt axis” about which the subject skull can be tilted laterally. The coronal-tilt axis passes horizontally through bregma and lambda parallel to the anterior-posterior motions of the manipulator.
[0060] Referring again to the embodiment shown in FIG. 1( c ), first and second mounting bars 152 , 154 extend from the base 14 of the first U-frame 12 . The mounting bars 152 , 154 extend toward the gauge post 146 and can be used for mounting an appropriate snout adapter 160 (FIG. 1( b )) or other suitable holding implement for the particular body to be held by the stereotaxic holder 10 . A representative snout adapter is described later below.
[0061] Referring now to FIG. 2, a representative embodiment of a base 180 comprises a base plate 182 having first and second opposing lateral edges 184 , 186 . Adjacent and coextensive with each lateral edge is a respective dovetail rail 188 , 190 or alternative analogous slide mechanism allowing attachment and detachment of implements (such as a manipulator 200 as described below) as well as controlled movement of attached implement(s) in the directions in which the rails 188 , 190 extend. Beneath each corner of the base plate is a respective non-slip, adjustable, leveling pad 192 used to keep the base 180 level on a working surface and to keep the base firmly in place on the working surface. The base 180 shown in FIG. 2 includes a stereotaxic holder 10 , such as the embodiment shown in FIGS. 1 ( a )- 1 ( c ), mounted thereto.
[0062] A representative embodiment of a manipulator 200 is shown in FIGS. 3 and 4. The depicted embodiment comprises a dovetail slide block 202 adapted to be mounted onto a dovetail rail 188 , 190 (shown mounted on the dovetail rail 188 ) of the base 180 , thereby permitting alignment of the Cartesian axes (X-, Y-, and Z-axes) of the manipulator 200 with the Cartesian axes PAX X , PAX Y , PAX Z of the stereotaxic holder 10 . After mounting the manipulator 200 to the desired rail and sliding it to the desired location on the rail, the manipulator 200 can be affixed rigidly to the rail by tightening a cinching screw 204 (obstructed by foreground structure in this view) threaded into the slide block 202 . The manipulator 200 comprises a distal “controlled end” 206 and a first shift mechanism 208 , a second shift mechanism 210 , and a third shift mechanism 212 for achieving controlled shift motions of the controlled end 206 along each of the three Cartesian axes (i.e., along the Y-axis, Z-axis, and X-axis, respectively). The first shift mechanism 208 is used for moving (after the manipulator 200 is mounted to the base 180 ) the controlled end 206 in the Y-direction in a controlled manner. To such end, the knurled knob 214 is turned, which causes a corresponding shift movement of a block 207 in the Y-direction relative to the block 202 (FIG. 4). The second shift mechanism 210 is used for moving the controlled end 206 in the Z-direction in a controlled manner. To such end, the knurled knob 216 is turned, which causes a corresponding shift movement of a block 209 relative to a guide member 211 . Finally, the third shift mechanism 212 is used for moving the controlled end 206 in the X-direction in a controlled manner. To such end, the knurled knob 218 is turned, which causes a corresponding shift movement of a guide member 213 relative to the block 209 . Each shift mechanism 208 , 210 , 212 is configured in the illustrated embodiment as a dovetail slide mechanism. However, as discussed above with respect to the stereotaxic holder 10 , any of the shift mechanisms 208 , 210 , 212 alternatively can be any of various other analogous mechanisms. In the illustrated embodiment, each knurled knob 214 , 216 , 218 is attached to the terminus of a respective threaded shaft (not visible in the drawing).
[0063] In the embodiment depicted in FIGS. 3 and 4, each shift mechanism 208 , 210 , 212 includes a respective electronic digital scale 220 , 222 , 224 that displays a measured position along the respective axis. (In a representative alternative embodiment, respective vernier scales, rather than electronic digital scales, can be used to display shift position along each of the respective Cartesian axes.) Compared to a vernier scale, an electronic digital scale has advantages including greater resolution, lesser probability of reading errors, and capability of being reset to “zero” along the respective axis. Exemplary digital scales include DIGIMATIC™ scales (e.g., series 572 ) manufactured by Mitutoyo, Japan. Another candidate digital scale is any of various highly accurate “glass scales” such as DRO model 211 manufactured by Anilam, Miramar, Fla. By way of example only, with respect to a manipulator having shift movement ranges suitable for a mouse or rat animal subject, each of the shift mechanisms 208 , 210 , 212 has a motion range of 70 mm along the respective axis. It will be understood readily that these ranges can be made larger or smaller as required to accommodate larger or smaller subjects, respectively.
[0064] The controlled end 206 of the manipulator 200 is configured (by any of various possible attachment means) to have any of various implements attached to it. Thus, after performing alignment of the Cartesian axes of the manipulator 200 with the respective axes of the stereotaxic holder 10 , an attached implement can be shifted along each of the Cartesian axes of the stereotaxic holder 10 in a controlled manner. By way of example, the depicted embodiment (FIG. 4) defines a female dovetail block 226 . Each of the various implements that are attachable individually to a controlled end 206 having such a configuration has a conforming male dovetail rail segment mounted to an adapter block. The male dovetail rail segment allows the implement to slide into the female dovetail block 226 and thus be affixed to the controlled end 206 . A cinching screw 228 is used to tighten the implement on the controlled end 206 .
[0065] Desirably, for reasons that will be more apparent from the following discussion, the adapter block on each implement desirably is “self-indexing” with respect to the controlled end 206 . By “self-indexing” is meant that any of various implements attachable to the controlled end can be attached with the functional end of the implement being at the same location, in three dimensional space, from one implement to the next. To such end, using the depicted embodiment by way of example, the female dovetail block 226 on the manipulator and/or the adapter block on each implement is provided with a mechanical stop (e.g., a pin or the like, not shown) that engages the other block in a consistent manner. Thus, the adapter block of any of various implements is mountable at exactly the same position, from one implement to another, relative to the female dovetail block 226 . Self-indexing allows any of various implements to be attached to the manipulator without a need to re-adjust the manipulator or implement immediately after each mounting.
[0066] Many implements mountable to the controlled end 206 have a longitudinal axis O Z . Another advantage of the “self-indexing” feature is that the axis O Z of any implement mounted on the controlled end 206 is, so long as the manipulator has not been adjusted in the meantime, automatically coincident with the axis O Z of the previous implement and/or the subsequent implement mounted to the controlled end 206 . Again, this eliminates a need to re-adjust the manipulator 200 after changing the implement mounted to the controlled end 206 .
[0067] The manipulator 200 desirably also includes a 3-axis universal joint 230 . As shown in FIG. 4, the universal joint 230 comprises a first pivot block 232 mounted to an end of the block 207 , a second pivot block 234 tiltably mounted to the first pivot block 232 , and a third pivot block 236 swingably mounted to the second pivot block 234 . An end of the guide member 211 is mounted to the third pivot block 236 . The first pivot block 232 is tilted controllably as required about a first pivot axis P Y relative to the block 207 by turning a respective jack screw 238 . The second pivot block 234 is tilted controllably about a second pivot axis P X relative to the first pivot block 232 by turning a respective jack screw 240 . The third pivot block 236 is swung controllably as required about a third pivot axis P Z relative to the second pivot block 234 by turning a respective jack screw 242 . Such controlled tilt and swing motions about one or more of the respective axes P X , P Y , and P Z are normally extremely limited in scope. They are performed normally whenever it is desired or necessary to bring the three Cartesian axes of shift motion of the controlled end 206 (achieved by the manipulator 200 ) into exact orthogonal relationship with each other and/or to align the three Cartesian axes of shift motion of the controlled end 206 (achieved by the manipulator 200 ) exactly with the three Cartesian axes of the stereotaxic holder 10 . Such adjustments can be advantageous after the manipulator 200 and/or stereotaxic holder 10 are mounted to the base 180 .
[0068] A first example implement mountable to the controlled end 206 is a centering scope 280 , a representative embodiment of which is shown in FIG. 5. The centering scope 280 , when attached to the controlled end 206 of the manipulator 200 , desirably includes a cross-hair reticle or other suitable “optical finder” that can be trained on the reticle or cross-hair target of the centering gauge 148 and thus be used as an optical locating and centering device. The centering scope 280 includes a self-indexing adapter block 282 fitted with a male dovetail rail segment 284 configured to slide into and be held in the female dovetail socket 226 of the electrode manipulator 200 . The centering scope 280 includes an eyepiece lens 286 , an optical tube 288 , and an objective lens 290 . The centering scope 280 can have any convenient magnification, such as 20 x magnification, sufficient to obtain, for example, accurate alignment of the optical axis O Z of the centering scope with the axis PAX Z of the stereotaxic holder 10 (such alignment is shown in FIG. 4). After performing the alignment, the centering scope 280 can be detached from the controlled end 206 and a new implement attached to the controlled end with the longitudinal axis O Z of the implement automatically being aligned accurately with the axis PAX Z . Further detail on use of the centering scope 280 is provided later.
[0069] A second example implement is a drilling unit 300 for use in drilling a hole in a subject animal's skull or for performing analogous tasks in preparation for implanting a probe at the desired locus in the subject body, or for any of various other surgical purposes. A representative embodiment of a drilling unit 300 is shown in FIG. 6, and includes a self-indexing adapter block 302 , a male dovetail rail segment 304 , motor 306 , housing 308 , and chuck 310 adapted to hold, e.g., a drill bit 312 . Normally, the drilling unit 300 , when mounted to the controlled end 206 of the electrode manipulator 200 , presents the drill bit 312 coaxially with the axis O Z of the implement (e.g., the centering scope 280 ) previously attached to the controlled end.
[0070] A third example implement is a syringe holder 330 adapted to hold a surgical or microinjection syringe. A representative embodiment of a syringe holder 330 is shown in FIG. 7, and includes a self-indexing adapter block 332 , a male dovetail rail segment 334 , a syringe enclosure 336 configured and dimensioned to hold a particular type of syringe 338 , an adjustable “zeroing” scale 340 , and a needle guide tube 342 . Normally, the syringe holder 330 presents a hollow needle 344 or probe to be inserted, along the axis O Z , into the desired locus in the subject animal.
[0071] A fourth example implement is a dial test indicator unit 360 used for determining and calibrating the alignment of the axis O Z , such as whether the axis O Z is oriented exactly perpendicularly to the surface of the plate 132 (or of the plate 182 ) and whether all three axes of the electrode manipulator 200 are exactly perpendicular to each other and/or exactly aligned with the corresponding Cartesian axes of the stereotaxic holder 10 . Such determinations and calibrations are similar to analogous determinations and calibrations, respectively, (termed “sweeping in” or “indicating”) performed with three-axis machine tools. A representative embodiment of a dial test indicator unit 360 is shown in FIG. 8, and includes a self-indexing adapter block 362 , a male dovetail rail segment 364 , a shaft 366 having an axis O Z alignable with or relative to the axis PAX Z of the stereotaxic holder 10 , an arm 368 that is oriented angularly relative to the axis O Z in an adjustable manner, and a dial indicator 370 (e.g., LAST WORD™ indicator, model 711-MF, manufactured by Starrett, Athol, Mass.) including a contact point 372 . The shaft 366 is rotatable relative to the adapter block 362 , and can be manipulated to move (raise and lower) the position of the arm 368 (with dial indicator 370 ) along the axis O Z . A collar 374 can be cinched onto the shaft 366 to hold the shaft 366 at a particular position along the axis O Z relative to the adapter block 362 . A threaded shaft 376 (to which a knurled nut 374 is threaded) cinches the arm 368 at a desired angular orientation relative to the shaft 366 .
[0072] As an example protocol with which the dial indicator can be used, the dial indicator is mounted to the controlled end 206 with the shaft 366 oriented vertically downward toward the surface of the plate 182 . The contact point 372 is placed in contact with the surface of the plate 182 . The user observes the numerical reading on the dial indicator 370 while rotating the shaft 366 about the axis O Z . If the displayed numerical value changes with angle of rotation of the shaft 366 , axial adjustment can be performed by turning the jack screws 238 , 240 (FIG. 4) as required until the dial indicator 370 reads the same value with any angle of rotation.
[0073] A fifth example implement is any of various cannula-insertion devices. A first embodiment 400 of a cannula-insertion device is shown in FIG. 9. The FIG. 9 embodiment 400 is relatively simple and comprises a self-indexing adapter block 402 , a male dovetail rail segment 404 , a shaft 406 having an axis O Z alignable with or relative to the axis PAX Z of the stereotaxic holder 10 , and a cannula-holding arm 408 configured to hold a cannula 410 (or analogous tool) such that a longitudinal axis thereof is aligned with the axis O Z . A cinching screw 412 affixes the cannula 410 to the terminus of the arm 408 . The FIG. 9 embodiment 400 can be used to hold and implant one cannula tube (or analogous tool) to a desired on-plane locus.
[0074] A second embodiment 420 of a cannula-insertion device is shown in FIG. 10. The FIG. 10 embodiment 420 is especially suitable for holding and implanting one or two cannulae (or analogous tools) to respective on-plane loci. The FIG. 10 device comprises a first cannula holder 422 for holding a first cannula 423 (or other tool shaped similarly to a cannula) and a second cannula holder 424 for holding a second cannula 425 (or other tool shaped similarly to a cannula). Mounted in their respective holders 422 , 424 , each cannula 423 , 425 can be placed at different respective X-axis and Y-axis coordinates. More specifically, the first cannula 423 held in the first cannula holder 422 is aligned longitudinally with the axis O Z (and thus directly alignable with or relative to the PAX Z axis of the stereotaxic holder 10 ). The second cannula 425 held in the second cannula holder 424 can be positioned relative to the first cannula 423 (while remaining parallel to the first cannula 423 ) by manipulating one or both of a first shift mechanism 426 and a second shift mechanism 428 described in more detail below.
[0075] The cannula-insertion device 420 comprises a self-indexing adapter block 430 including a male dovetail rail segment 431 , a shaft 432 inserted into the adapter block 430 and having an axis O Z , the first and second cannula holders 422 , 424 , respectively, and the first and second shift mechanisms 426 , 428 , respectively. The first shift mechanism 426 comprises a first member 434 attached to the shaft 432 , first and second parallel guide bars 435 , 436 , respectively, affixed to the first member 434 , and a second member 438 adapted to slide along the guide bars 435 , 436 . One or more extension springs (not shown) desirably are situated between the first and second members 434 , 438 to urge the members to move together. A force counter to the spring force is applied by a first micrometer head 440 which, when turned, controllably adjusts the spacing (along the indicated X-axis) between the first and second members 434 , 438 , and thus the spacing (along the indicated X-axis) between the first and second cannulae 423 , 425 . The second shift mechanism 428 comprises a member 442 to which first and second guide bars 444 , 445 , respectively, are affixed. The guide bars 444 , 445 slide relative to the member 438 . One or more extension springs (not shown) desirably are situated between the members 438 , 442 to urge the members to move together. A force counter to the spring force is applied by a second micrometer head 446 which, when turned, controllably adjusts the spacing (along the indicated Y-axis) between the members 438 , 442 and thus the spacing (along the indicated Y-axis) between the first and second cannulae 423 , 425 . The member 434 terminates with a clamp 447 adapted to grip the first cannula 423 whenever the screw 448 is tightened. Similarly, the member 424 terminates with a clamp 449 adapted to grip the second cannula 425 whenever the screw 450 is tightened. On the opposite side of the adapter block 430 is a collar 452 attached to the adapter block 430 and coaxial with the axis O Z . The shaft 432 terminates with a knurled knob 454 that, when turned, rotates the entire cannula-insertion device relative to the adapter block 430 about the axis O Z (i.e., about the indicated Z-axis). The angular orientation of the cannula-insertion device about the axis O Z can be locked by tightening a cinching screw (not shown) threaded through the collar 452 to engage the shaft 432 .
[0076] A third embodiment 470 of a cannula-insertion device is shown in FIG. 11, which has especial utility for independently holding and implanting one or two cannulae to respective off-plane loci. The FIG. 11 device 470 comprises the following components that are similar to corresponding components (described above) in the FIG. 10 embodiment 420 : self-indexing adapter block 472 , male dovetail rail segment 473 , and shaft 474 . The FIG. 11 device 470 comprises a first cannula holder 480 for holding a first cannula 481 (or other tool shaped similarly to a cannula) and a second cannula holder 482 for holding a second cannula 483 (or other tool shaped similarly to a cannula). The first and second cannulae 481 , 483 , respectively, are held in first and second cannula adapters 484 , 485 , respectively, mounted to respective first and second cannula holders 480 , 482 , respectively. When so mounted, the terminus of the first cannula 481 and the terminus of the second cannula 483 can be placed at different respective X-axis and Y-axis coordinates by manipulating one or both of a first shift mechanism 486 and a second shift mechanism 487 . Further detail regarding mounting the cannulae 481 , 483 in the respective cannula adapters 484 , 485 , and mounting the cannula adapters 484 , 485 in the respective cannula holders 480 , 482 is provided later below.
[0077] The first shift mechanism 486 , similar to the first shift mechanism 426 of the FIG. 10 embodiment 420 , comprises a first member 488 attached to the shaft 474 , first and second parallel guide bars 489 , 490 , respectively, affixed to the first member 488 , and a second member 491 adapted to slide along the guide bars 489 , 490 . One or more extension springs (not shown) desirably are situated between the first and second members 488 , 491 to urge the members to move together. A force counter to the spring force is applied by a first micrometer head 492 that, when turned, controllably adjusts the spacing (along the indicated X-axis) between the first and second members 488 , 491 , and thus the spacing (along the indicated X-axis) between the terminus of the first cannula 481 and the terminus of the second cannula 483 . The second shift mechanism 487 comprises a member 493 to which first and second guide bars 494 , 495 , respectively, are affixed. The guide bars 494 , 495 slide relative to the member 491 . One or more extension springs (not shown) desirably are situated between the members 491 , 493 to urge the members to move together. A force counter to the spring force is applied by a second micrometer head 496 that, when turned, controllably adjusts the spacing (along the indicated Y-axis) between the members 491 , 493 and thus the spacing (along the indicated Y-axis) between the terminus of the first cannula 481 and the terminus of the second cannula 483 .
[0078] To the member 488 is affixed a first arc plate 497 , and to the member 493 is affixed a second arc plate 498 . The first cannula holder 480 is attached to the first arc plate 497 , and the second cannula holder 482 is attached the second cannula holder 482 . The first cannula holder 480 comprises a slide mechanism comprising a plate 499 , a block 500 adapted to slide relative to the plate 499 as controlled by a lead screw 501 (manually turned using a knurled knob 502 ), and a tool clip 503 configured to grip the first cannula adapter 484 (or other suitably shaped tool). Thus, turning the knurled knob 502 controllably shifts the cannula 481 (or other tool) along a first cannula axis C 1 . The plate 499 can be adjustably moved along the arc defined by the first arc plate 497 so as to change the angle of the first cannula axis C 1 relative to the axis O Z (or to a line parallel to O Z ). Similarly, the second cannula holder 482 comprises a slide mechanism comprising a plate 504 , a block 505 adapted to slide relative to the plate 504 as controlled by a lead screw 506 (manually turned using a knurled knob 507 ), and a tool clip 508 configured to grip the second cannula adapter 485 . Thus, turning the knurled knob 507 controllably shifts the cannula 483 along a second cannula axis C 2 . The plate 504 can be moved adjustably along the arc defined by the second arc plate 498 so as to change the angle of the second cannula axis C 2 relative to the axis O Z . Furthermore, the respective angles of the cannula axes C 1 , C 2 relative to O Z (or to respective lines parallel to O Z ) need not be the same and can be adjusted independently.
[0079] Whenever the slide mechanism of the first cannula holder 480 is shifted fully downward, the first cannula 481 or other tool (held in the first cannula adapter 484 mounted to the first cannula holder 480 ) desirably is situated such that such that the terminus of the first cannula 481 (or other tool) is situated exactly on the axis O Z (and thus directly alignable with the PAX Z axis of the stereotaxic holder 10 ). To such end, the tool clip 503 and block 500 , functioning in combination with the first cannula adapter 484 ) desirably are “self-indexing,” as follows. FIG. 12 shows a first cannula adapter 484 (detached from the first cannula holder 480 ) placed in a “gauge block” 900 . The first cannula adapter 484 includes a shoulder portion 902 having a facing surface 904 . The gauge block 900 is used to establish a standard length (L) from the facing surface 904 to the terminus 906 of the cannula 481 . The first cannula adapter 484 (with cannula 481 or other tool attached but with the screw 908 loosened) is placed in the gauge block 900 such that the facing surface 904 contacts a first surface 910 of the cannula adapter. Meanwhile, the terminus 906 of the cannula 481 is placed in contact with a hardened region 912 of a second surface 914 . Afterward, the screw 908 is tightened to fasten the cannula 481 to the cannula adapter 484 . The cannula adapter with attached cannula can be removed from the gauge block 900 and mounted to the first cannula holder 480 (FIG. 11) such that the facing surface 904 contacts the upward-facing surfaces of the tool clip 503 and the block 500 . Whenever the cannula adapter 484 is mounted in such a manner to the first cannula holder 480 (with the slide mechanism of the first cannula holder 480 fully shifted downward), the terminus 906 of the first cannula 481 (or other tool) is situated exactly on the axis O Z (as shown in FIG. 11), and thus directly alignable with or relative to the PAX Z axis of the stereotaxic holder 10 . Any other tool mounted to the first cannula adapter 484 in the manner described above will also have its terminus contact the axis O Z .
[0080] Desirably, the second cannula adapter 485 is “self-indexing” with respect to the second cannula holder 482 in the same manner as discussed above. It also will be appreciated that a cannula 483 or other tool can be mounted to the second cannula adapter 485 , and the second cannula adapter mounted to the second cannula holder 482 , in the same manner as described above regarding the first cannula. In any event, the terminus of the second cannula 483 (held in the second cannula adapter 485 mounted to the second cannula holder 482 ) can be positioned relative to the terminus of the first cannula 481 by manipulating one or both of the first shift mechanism 486 and the second shift mechanism 487 .
[0081] Whenever the first cannula 481 has been mounted in a self-indexing manner as described above, so as to place the terminus of the first cannula on the axis O Z , the plate 499 can be moved adjustably along the arc defined by the first arc plate 497 so as to change the angle of the first cannula axis C 1 relative to the axis O Z (or to a line parallel to O Z ) without changing the location, in three-dimensional space, of the terminus of the first cannula 481 . Similarly, whenever the second cannula 483 has been mounted in a self-indexing manner as described above, the plate 504 can be moved adjustably along the arc defined by the second arc plate 498 so as to change the angle of the second cannula axis C 2 relative to the axis O Z (or to a line parallel to the axis O Z ) without changing the location, in three-dimensional space, of the terminus of the second cannula 483 .
[0082] As with the FIG. 10 embodiment, the FIG. 11 embodiment can be provided with a knurled knob and collar (corresponding to the knob 454 and collar 452 of the FIG. 10 embodiment). If such a knob is provided, turning the knob would cause rotation of the entire cannula-insertion device 470 relative to the adapter block 472 about the axis O Z (i.e., about the indicated Z-axis).
[0083] The FIG. 11 embodiment 470 can be used to hold any of various tools other than cannulae. For use, the cannula-insertion device 470 is mounted to the controlled end 206 of the manipulator 200 and positioned at a desired location relative to the subject body. Before mounting a cannula (mounted to its respective cannula adapter) to the device 470 , a miniature drilling device can be mounted to the respective cannula holder 480 , 482 for drilling a hole through which the subject cannula is to be inserted. After drilling the respective hole, the drilling device is detached from the cannula holder and replaced with the respective cannula (in its respective cannula adapter).
[0084] The drilling device (or any other tool mounted to a cannula holder 480 , 482 ) desirably is self-indexing in the same manner as the respective cannula adapter 484 , 485 . Any of various self-indexing tools can thus be attached wherein the terminus of the tool is always situated (whenever the corresponding cannula holder is shifted to its full-down position) at exactly the same position in three-dimensional space. This advantageously avoids having to perform repositioning each time a new tool is mounted to the cannula-insertion device 470 .
[0085] Based on the previous discussion, it will be appreciated that any of the slide and shift mechanisms of the embodiments of the cannula-insertion devices described above can be substituted with any of various alternative mechanisms. Furthermore, the knurled knobs need not be actuated manually. Rather, it will be immediately apparent that actuation of one or more slide or shift mechanisms can be automated by using motors or the like instead of the knurled knobs.
[0086] A sixth example implement is a stereotaxic alignment indicator, of which a representative embodiment 520 is depicted in FIG. 13. When mounted to the controlled end 206 of the manipulator 200 , the stereotaxic alignment indicator can provide dimensional feedback to the user required to obtain a desired adjustment/alignment of coronal tilt and dorsal tilt of a body mounted to the stereotaxic holder 10 . The embodiment 520 of FIG. 13 comprises a self-indexing adapter block 521 , a male dovetail rail segment 522 , a shaft 523 inserted into the adapter block 521 and having an axis O Z , a knurled knob 524 attached to the shaft 523 , and a collar 525 . Turning the knurled knob 524 causes rotation of the entire stereotaxic alignment indicator 520 relative to the adapter block 521 about the axis O Z . The angular orientation of the stereotaxic alignment indicator 520 about the axis O Z can be locked by tightening a cinching screw (not shown) threaded through the collar 525 to engage the shaft 523 .
[0087] The shaft 523 is affixed to an angled block 527 . On a distal edge of the angled block 527 is mounted a bilateral slide mechanism 528 . The bilateral slide mechanism 528 comprises a center block 529 and opposing flanking blocks 530 , 531 . Parallel guide bars 532 , 533 are affixed to and extend bilaterally from the center block 529 through the flanking blocks 530 , 531 . A threaded shaft 534 (with oppositely pitched threads on each half) extends bilaterally from the center block and is threaded into the flanking blocks 530 , 531 . Thus, turning a knurled knob 535 attached to an end of the threaded shaft 534 causes the flanking blocks 530 , 531 to move synchronously toward or away from the center block 529 . To each flanking block 530 , 531 is mounted a respective vertical slide mechanism 536 , 537 . Each vertical slide mechanism comprises a pair of parallel guide bars 538 a , 538 b and 539 a , 539 b , respectively. The guide bars slide vertically relative to the respective flanking block 530 , 531 , and terminate with a respective pin bar 540 , 541 affixed to the respective guide bars 538 a , 538 b and 539 a , 539 b , respectively. Attached to each pin bar 540 , 541 is a respective contact pin 542 , 543 . Mounted to the angled block 527 are first and second dial indicators 544 , 545 for the first and second slide mechanisms 536 , 537 , respectively. Each of the dial indicators 544 , 545 has a stem that extends through the respective flanking block 530 , 531 and a respective tip 546 , 547 that contacts the respective pin bar 540 , 541 .
[0088] During use, the terminus of each contact pin 542 , 543 is placed in contact with the surface of a subject body. Normally, the force of gravity (together with the relatively weak spring bias of the respective tip 546 , 547 ) provides sufficient bias to the pin bars 540 , 541 for the respective contact pins 542 , 543 to remain in contact with a test surface. The vertical position of one contact pin relative to the other pin can be ascertained by reading the dial indicators 544 , 545 . I.e., a change in the vertical position of a contact pin 542 , 543 , causes a corresponding change in the deflection of the respective tip 546 , 547 . As is generally known with a dial indicator of the type shown, whenever the tip of the dial indicator is displaced a corresponding change is caused in the dimensional value indicated by the dial indicator. In the FIG. 12 embodiment, the tip 546 , 547 of each dial indicator 544 , 545 contacts the upper surface of the respective pin bar 540 , 541 . Thus, a change in the vertical position of a contact pin 542 , 543 is translated to a change in the vertical position of the respective pin bar 540 , 541 , thereby changing the dimensional value displayed by the respective dial indicator 544 , 545 . For ease in calibration, the dial of each dial indicator 544 , 545 is adjustable to a desired null value as desired or required. Dial indicators (e.g., LAST WORD™ indicators, model 711-MR, manufactured by Starrett, Athol, Mass.) having an accuracy sufficient for use with rodent skulls desirably have an accuracy of +/−10 μm.
[0089] The lateral gap between the contact pins 542 , 543 can be adjusted as required by turning the knurled knob 535 . The obtained lateral gap is equilateral relative to the axis O Z (i.e., regardless of the spacing between the pins 542 , 543 , each pin is an equal distance from the axis O Z ). The dimension of the actual gap can be ascertained by consulting a vernier scale 548 .
[0090] During use, the stereotaxic alignment indicator 520 is mounted to the manipulator 200 as described above. Generally, the alignment indicator 520 is first oriented such that a line connecting the termini of the contact pins 542 , 543 is parallel with the axis PAX X of the stereotaxic holder 10 , as shown in FIG. 14( a ). By turning the knob 216 on the manipulator 200 , the alignment indicator 520 is lowered down onto the surface of the subject body structure (e.g., skull, not shown) being held by the stereotaxic holder 10 until the contact pins 542 , 543 contact the surface of the body structure. The gap between the contact pins 542 , 543 can be adjusted appropriately, by turning the knob 535 , to the desired value to contact the desired bilateral loci on the body structure. For example, if the body structure is a rodent skull, then the contact pins 542 , 543 can be adjusted to contact bilateral loci flanking the sagittal suture or to correspond with the actual distance between bregma and lambda. To achieve a level aspect of a line extending between the points of contact of the indicator probes with the body structure, the knob 98 of the stereotaxic holder 10 is adjusted, as described above, until both dial indicators 544 , 545 read exactly the same value or both indicate a “null” value. Alternatively, adjustment is made to achieve a desired tilt (other than level) of the subject body structure, as indicated on the dial indicators 544 , 545 .
[0091] To achieve alignment in the other of the X- and Y-axes, the stereotaxic alignment indicator 520 is raised off the body structure (by turning the knob 216 ), rotated 90 degrees by turning the knob 524 , and lowered again onto the body structure (by turning the knob 216 ). Thus, a line connecting the termini of the contact pins 542 , 543 is now parallel with the axis PAX Y of the stereotaxic holder 10 , as shown in FIG. 14( b ). For example, after aligning the sagittal suture of a rodent skull parallel with the PAX Y axis, the alignment indicator 520 is lowered onto the skull until one of the contact pins 542 , 543 contacts bregma and the other contact pin contacts lambda. The knob 120 on the stereotaxic holder 10 is turned to adjust the dorsal tilt of the skull until both dial indicators 544 , 545 display the same value or a null value, or a desired differential value. As a result of this adjustment, a line extending between bregma and lambda along the sagittal suture is level or at the desired angular orientation to within, e.g., +/−10 μm.
[0092] With respect to an alignment indicator, any of various alternative embodiments to FIG. 13 embodiment are possible. For example, and not intending to be limiting, the dial indicators 544 , 545 can be replaced with any of various digital scales, such as those discussed elsewhere herein. Further alternatively, the mechanical vertical slide mechanisms 536 , 537 (with associated dial indicators 544 , 545 ) can be replaced with a “touch signal probe” as known in the art or with one or more laser position detectors.
[0093] As discussed above, an appropriate snout adapter 160 or other implement for holding a subject body can be attached to the base 14 of the first U-frame 12 . (See generally FIG. 1( b ) showing a representative embodiment of a snout adapter 160 attached to the mounting rods 152 , 154 .) An appropriate snout adapter is particularly useful when the subject body is a head or skull. In view of the many differences in skull size and shape among various possible subject animals, the appropriate snout adapter will have a correspondingly different configuration. Snout adapters are used usually in conjunction with other head-holding implements that usually include ear bars 20 , 22 as shown in FIGS. 1 ( a )- 1 ( b ). A combination of a snout adapter and ear bars provides a three-point contact system for the subject skull, and three-point contact systems are especially effective for holding the skulls of smaller rodents such as mice, rats, squirrels, and the like. Heads of larger animals such as cats, dogs, and primates frequently need at least one other contact point for adequate stability. For such heads, “eye bars” (that engage the infra-orbital ridge) are used frequently in addition to tooth bars and ear bars. Of course, if the body being held is not a head or skull, the implements used to grasp the body have other respective configurations each of which desirably conforming to a respective anatomical structure so as to provide a stable point of contact.
[0094] The embodiment of the snout adapter 160 shown in FIGS. 1 ( a ) and 1 ( b ), which is especially suitable for holding a rodent skull, is detailed in FIG. 15. The FIG. 15 snout adapter 160 is especially suitable for use in conjunction with ear bars, such as the ear bars 20 , 22 shown in FIGS. 1 ( a )- 1 ( b ), appropriately sized for the subject skull. The snout adapter 160 comprises a mounting block 562 and a snout-engagement portion 563 .
[0095] The mounting block 562 defines apertures 564 through which the mounting bars 152 , 154 (FIG. 1( b )) extend. A lock screw 565 can be tightened for locking the mounting block 562 at a desired location on the mounting bars 152 , 154 . Thus, whenever the snout adapter 160 is mounted to the first U-frame 12 , the snout adapter 160 is movable relative to the first U-frame 12 substantially along the Y-axis (i.e., to provide a desired anterior-posterior adjustability).
[0096] The snout-engagement end 563 comprises a snout-clamp/gas-mask 566 and a palate bar 567 . The palate bar 567 defines a through aperture 568 sized to allow the subject's incisors to extend therethrough. The palate bar also defines lateral recesses 569 configured and situated to contact the subject's molars, allowing the subject's palate to rest on a mid-line ridge 570 . Whenever the palate bar 567 is thus engaged with the palate of the subject, the snout-clamp/gas-mask 566 can be moved posteriorly relative to the mounting block 562 along the indicated Y-axis to fit over the subject's nose (i.e., the subject's nose is inserted into a cavity 571 defined by the snout-clamp/gas-mask 566 ), thereby “clamping” the subject's snout. After a desired fit is obtained, a locking screw 572 is tightened. The snout-clamp/gas-mask 566 is also tiltable about the indicated Y-axis, relative to the mounting block 562 . The particular tilt can be retained by tightening the locking screw 572 .
[0097] The snout-clamp/gas-mask 566 also comprises a gas inlet 573 and a gas outlet 574 to allow administration of a gas anesthetic to the subject while the subject's head is engaged in the snout adapter 160 . More specifically, the gas inlet 573 is connectable to a supply of anesthetic gas. The gas outlet 574 is connectable, for example, to a waste-gas reservoir maintained under a slight subatmospheric pressure.
[0098] As noted above, FIG. 15 shows a representative embodiment of a snout adapter. Any of various other snout adapters as currently known in the art readily can be adapted for mounting to the stereotaxic holder 10 . Example conventional snout adapters are available from, for example, Kopf Instruments, Tujunga, Calif. (e.g., model 926 “mouse adapter,” model 920 “rat adapter,” model 924 “rotational rat adapter,” and model 906 “rat anesthesia mask.”
[0099] Whereas apparatus according to the invention are especially adapted for holding a body (i.e., animal body or portion thereof for performing a surgical or diagnostic intervention, for example), it will be appreciated that the subject “body” is not limited to animate bodies. In fact, any of various inanimate “bodies” or other workpieces can be held and aligned in a stereotaxic manner using apparatus according to the invention.
[0100] A representative protocol for performing a stereotaxic alignment is set forth below as performed using a rodent skull as a representative body structure. In this protocol, it is assumed that the stereotaxic holder 10 and the manipulator 200 are attached to the base 180 as described above. Also, this example protocol is described in the context of the specific embodiments shown in the figures described above. It will be understood that details of the protocol may change with changes, for example, in the specific embodiment that is used and in the particular subject.
[0101] (1) If required, the orthogonality of the X-, Y-, and Z-axes of the manipulator 200 are checked. This can be performed, e.g., by mounting the dial test indicator 360 to the controlled end 206 of the manipulator 200 , performing “sweeping-in” or “indicating” as described earlier above, and adjusting the jack screws 238 , 240 , 242 on the universal joint 230 of the manipulator as required.
[0102] (2) The dial test indicator 360 is detached from the controlled end 206 and replaced with the centering scope 280 . The gauge post 146 is placed on the pad 150 . The centering scope 280 is positioned, using the manipulator 200 , so that the reticle in the scope is aligned exactly with (and focused on) the centering gauge 148 on the gauge post 146 . This action establishes coincidence of the axis O Z of the centering scope 280 (and thus of the controlled end 206 ) with the axis PAX Z . Also, by focusing the scope 280 on the centering gauge 148 , the point on the PAX Z axis where the axes PAX X and PAX Y cross each other is established. If the manipulator 200 is equipped with digital scales 220 , 222 , 224 , each scale desirably is nulled at this time. In any event, with respect to both the stereotaxic holder 10 and the manipulator 200 , a “0,0,0” point is identified in three-dimensional space (i.e., the point where the axes PAX X , PAX Y , PAX Z orthogonally cross each other). The 0,0,0 point is the reference point from which various loci in or on the subject body are located accurately in three-dimensional space. After the 0,0,0 point is located, the gauge post 146 is removed.
[0103] (3) The skull is mounted to the stereotaxic holder 10 using a proper combination of holding implements such as ear bars and snout adapter. If desired, the controlled end 206 of the manipulator can be moved out of the way. The advantage of previously having nulled the scales 220 , 222 , 224 is immediately apparent because the controlled end 206 can be returned with high accuracy to its previous position simply by adjusting the knobs 214 , 216 , 218 until all three scales 220 , 222 , 224 return to their respective null values. In any event, after mounting the skull to the stereotaxic holder 10 , the centering scope 280 is returned to the 0,0,0 position and the axis O Z is made coincident with the PAX Z axis.
[0104] (4) While observing through the centering scope 280 , the skull is shifted (using the shift mechanisms 28 , 30 , 32 as required), to place the desired target feature at the 0,0,0 point (i.e. at the cross-reticle of the centering scope in all three dimensions). For a rodent skull, the target feature is often bregma. However, as noted earlier above, any of various other target features on or in the body can be used, including artificially implanted features.
[0105] (5) While still observing through the centering scope 280 , a desired anterior-posterior reference line (e.g., a natural linear feature such as the sagittal suture of the skull) is aligned with the Y-direction reticle line in the centering scope. Alternatively, for example, regarding bregma as a first reference point, the centering scope can be shifted (by manipulating the Y-direction shift mechanism 208 ) to the lambda locus on the skull, and the “swing” of the stereotaxic holder 10 can be adjusted (using the knob 140 ) as required to align an imaginary anterior-posterior reference line connecting bregma and lambda on the subject skull exactly with the PAX Y axis.
[0106] (6) Using the Y-direction shift mechanism 208 , the controlled end 206 is shifted to a position at which the axis O Z intersects the anterior-posterior line of the skull at midlength, such as midlength between bregma and lambda.
[0107] (7) The centering scope 280 is removed, and the stereotaxic alignment indicator 520 is attached to the controlled end 206 of the manipulator 200 . Normally, coronal tilt of the subject skull is determined first. This can be done by lowering the contact pins 542 , 543 onto respective points on the skull that are located bilaterally relative to the anterior-posterior reference line. The knob 98 on the stereotaxic holder 10 can be adjusted as required to obtain either a level line connecting the two bilateral points or to obtain a line at the desired coronal tilt angle.
[0108] (8) The stereotaxic alignment indicator 520 is retracted from the skull (using the Z-axis shift mechanism 210 of the manipulator) sufficiently to allow a 90-degree rotation (using the knob 524 ) of the alignment indicator 520 . Thus, the alignment indicator is positioned for ascertaining the dorsal tilt of the subject skull. The gap between the contact pins 542 , 543 is set appropriately (using the knob 535 ), for example to equal the bregma-lambda distance. The alignment indicator is then lowered until the contact pins 542 , 543 contact the skull on the anterior-posterior reference line. The dorsal tilt of the skull is adjusted (by manipulating the knob 34 on the stereotaxic holder 10 ) until the desired readings (level or otherwise) are obtained on the dial indicators 544 , 545 . For example, some rodent brain atlases locate features of the brain relative to bregma and lambda being level; other atlases locate features relative to a 2.25-mm offset of bregma to lambda. Either adjustment can be made readily in this step.
[0109] Upon completing steps (1)-(8), the subject skull is now positioned in a true stereotaxic plane according to the pertinent reference (brain atlas or other appropriate reference), with a pre-determined degree of confidence based on the accuracy of the indicators (dials, scales, etc.) provided on the apparatus according to the invention. The alignment indicator can be retracted from the skull and replaced with any of various implements attached to the controlled end so as to continue with the surgery or other research intervention involving the subject skull. For example, any of various electrodes, cannulae, probes, etc. can be implanted to desired respective loci within the skull (e.g., within the brain) at a high level of confidence that the desired loci will, in fact, be “hit.”
[0110] Whereas the invention has been described in connection with representative embodiments, it will be apparent that the invention 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.
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Apparatus and methods are disclosed for holding a subject body (or body portion, generally termed “body”) at a desired stereotaxic orientation relative to a known reference point, in three-dimensional space, where a reference X-axis, a reference Y-axis, and a reference Z-axis mutually intersect. The reference point can be co-positioned with a target point on or in the subject body so as to place the body in a reference position used in a corresponding anatomical atlas or other locational index. With the body so positioned, a probe or other tool can be inserted into the body to a desired locus with high accuracy (in hitting the desired locus) and with high precision (from one animal to the next). The methods and apparatus have especial utility in surgical and diagnostic interventions, including such interventions involving the central nervous system encased in surrounding skull or the like.
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PRIORITY
[0001] The present application is a non-provisional patent application which claims the benefit of provisional application serial number 61/052441, filed May 12, 2008, the disclosure of which is incorporated in its entirety by reference herein.
BACKGROUND OF THE INVENTION
[0002] Efficient use of space in controlled environment agriculture generally requires a means to change the distance between maturing plants. Most often, spacing is accomplished through the use of labor because of the high costs and complexity associated with automated systems.
[0003] The present invention features an expandable hydroponic growing system is advantageous in that it can reduce the labor requirements by increasing the automation of re-spacing via an inventive arrangements of connector bars and bases.
[0004] Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 shows a perspective view of a generic expandable hydroponic growing system of the present invention.
[0006] FIG. 2A shows a perspective view of an expandable hydroponic growing system of the present invention.
[0007] FIG. 2B shows a top view of the arrangement of the lower bases in relation to each other.
[0008] FIG. 2C shows a top view of the arrangement of the upper bases in relation to each other.
[0009] FIG. 3 shows a top view of the lower or upper bases in relation to each other, where the bases are cylindrical instead of cubical
[0010] FIG. 4 shows a perspective view of the system with plants disposed within the upper bases.
[0011] FIG. 5 shows a perspective view of an alternative expandable hydroponic growing system of the present invention.
[0012] FIG. 6 shows a top view of the arrangement of the lower base components in relation to each other.
[0013] FIG. 7 shows a top view of the arrangement of the upper base components in relation to each other.
[0014] FIG. 8 shows a perspective view of the system in a semi-expanded position.
[0015] FIG. 9 shows a perspective view of the system in a folded position.
[0016] FIG. 10 shows a buoyancy structure with deep walls and a cavity. This buoyancy structure may be a base/component itself or be attached to a base/base component.
[0017] FIG. 11 shows a cross section of the buoyancy structure shown in FIG. 10 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] Referring now to FIG. 1 , the present invention features an expandable hydroponic growing system. In some embodiments, the system comprises a first lower base 7100 , a second lower base 7110 , a third lower base 7120 and a fourth lower base 7130 .
[0019] In some embodiments, the lower bases are arranged in a rectangle configuration with respect to each other. For example, the first lower base 7100 is at a first corner of the rectangle, a second lower base 7110 is at a second corner of the rectangle, a third lower base 7120 is a third corner of the rectangle and a fourth lower base 7130 is at a fourth corner of the rectangle configuration.
[0020] In some embodiments, the system comprises a first upper base 7200 , a second upper base 7210 , a third upper base 7220 and a fourth upper base 7230 . In some embodiments, the upper bases are arranged in a rectangle configuration 400 with respect to each other. For example, the first upper base 7200 is at a first corner of the rectangle, a second upper base 7210 is at a second corner of the rectangle, a third upper base 7220 is a third corner of the rectangle and a fourth upper base 7230 is at a fourth corner of the rectangle configuration.
[0021] In some embodiments, the rectangle configuration is a square configuration. In some embodiments, when the rectangle configuration is a square configuration, the bar pairs are of the same length.
[0022] In some embodiments, the system further comprises pairs of bars. For example, a first bar pair 7520 comprises a first bar 7500 and a second bar 7502 . The first bar 7500 has a first end and a second end. The first end pivotably connects to the first bottom base and the second end pivotably connects to the second upper base. The second bar 7502 having a first end and a second end. The first end pivotably connects to the lower second base and the second end pivotably connects to the first upper base. The ends of the bars can pivotably connect to any appropriate location on the bases. In some embodiments, the ends of the bars pivotably connect to the bases directly. In some embodiments, the ends of the bars pivotably connect to the bases through a tab that extends from the bases.
[0023] In some embodiments, the system comprises a second bar pair 7522 , which comprises a third bar 7504 and a fourth bar 7506 . The third bar 7504 has a first end and a second end. The first end pivotably connects to the second bottom base 7110 and the second end pivotably connects to the third upper base 7220 . The fourth bar 7506 has a first end and a second end. The first end pivotably connects to the lower third base 7120 and the second end pivotably connects to the second upper base 7210 . In some embodiments, the ends of the bars pivotably connect to the bases directly. In some embodiments, the ends of the bars pivotably connect to the bases through a tab that extends from the bases.
[0024] In some embodiments, the system comprises a third bar pair 7524 , which comprises a fifth bar 7508 and a sixth bar 7510 . The fifth bar 7508 has a first end and a second end. The first end pivotably connects to the third bottom base 7120 and the second end pivotably connects to the fourth upper base 7230 . The sixth bar 7510 has a first end and a second end. The first end of the sixth bar 7510 pivotably connects to the fourth base 7130 and the second end pivotably connects to the third upper base 7220 . In some embodiments, the ends of the bars pivotably connect to the bases directly. In some embodiments, the ends of the bars pivotably connect to the bases through a tab that extends from the bases.
[0025] In some embodiments, the system comprises a fourth bar pair 7526 , which comprises a seventh bar 7512 and an eighth bar 7514 . The seventh bar 7512 has a first end and a second end. The first end of the seventh bar 7512 pivotably connects to the fourth bottom base 7130 and the second end pivotably connects to the first upper base 7200 . The eighth bar 7514 has a first end and a second end. The first end of the eighth bar 7514 pivotably connects to the lower first base 100 and the second end pivotably connects to the fourth upper base. In some embodiments, the ends of the bars pivotably connect to the bases directly. In some embodiments, the ends of the bars pivotably connect to the bases through a tab that extends from the bases.
[0026] In some embodiments, the first lower base is disposed directly below the first upper base, the second lower base is disposed directly below the second upper base, the third lower base is disposed directly below the third upper base, and the fourth lower base is disposed directly below the fourth upper base.
[0027] In some embodiments, in a folded position, the first ends of the bars are pushed closer together. In an expanded position, the first ends of the bars are pushed farther apart, see for example, FIG. 4 . In some embodiments, the respective two bars of each bar pair slide pass each other on a same plane. In some embodiments, as an option, the respective two bars of each bar pair are pivotably hinged at their respective mid-regions.
[0028] In some embodiments, the system may be extended beyond four bases with additional bases. For example, the first base 7100 may be linked to an additional upper base and the first upper base 7200 may be linked to an additional lower base via a pair of bars in a similar fashion to the first, second, third and fourth pair of bars of the system.
[0029] The scope of the above system covers the expandable hydroponic growing systems 50 and 55 which are discussed in detailed below. In some specific embodiments of the present invention discussed below, the term “connector” is an example of a “bar”, and the term “base component” is an example of a “base”.
[0030] Referring now to FIG. 2A , FIG. 2B , and FIG. 2C the present invention features an expandable hydroponic growing system 50 . In some embodiments, the system comprises a first lower base 100 , a second lower base 110 , a third lower base 120 and a fourth lower base 130 , wherein each lower base has a first interior side (e.g., 102 , 112 , 122 , 132 ), a second interior side (e.g., 104 , 114 , 124 , 134 ), a first exterior side (e.g., 106 , 116 , 126 , 136 ) and a second exterior side (e.g., 108 , 118 , 128 , 138 ).
[0031] In some embodiments, the lower bases are arranged in a rectangle configuration 300 with respect to each other. For example, the first lower base 100 is at a first corner 310 of the rectangle, a second lower base 110 is at a second corner 320 of the rectangle, a third lower base 120 is a third corner 330 of the rectangle and a fourth lower base 130 is at a fourth corner 340 of the rectangle configuration.
[0032] In some embodiments, the system 50 comprises a first upper base 200 , a second upper base 210 , a third upper base 220 and a fourth upper base 230 . In some embodiments, each upper base has a first interior side (e.g., 202 , 212 , 222 , 232 ), a second interior side (e.g., 204 , 214 , 224 , 234 ), a first exterior side (e.g., 206 , 216 , 226 , 236 ) and a second exterior side (e.g., 208 , 218 , 228 , 238 ). In some embodiments, the upper bases are arranged in a rectangle configuration 400 with respect to each other. For example, the first upper base 200 is at a first corner 410 of the rectangle, a second upper base 210 is at a second corner 420 of the rectangle, a third upper base 220 is a third corner 430 of the rectangle and a fourth upper base 230 is at a fourth corner 440 of the rectangle configuration.
[0033] In some embodiments, the rectangle configuration 300 / 400 is a square configuration. In some embodiments, when the rectangle configuration is a square configuration, the bar pairs are of the same length.
[0034] In some embodiments, the system 50 further comprises pairs of bars. For example, a first bar pair 520 comprises a first bar 500 and a second bar 502 . The first bar 500 has a first end and a second end. The first end pivotably connects to the first exterior 106 side of the first bottom base and the second end pivotably connects to the first exterior side 216 of the second upper base. The second bar 502 having a first end and a second end. The first end pivotably connects to the first exterior side 116 of the lower second base and the second end pivotably connects to the first exterior side 206 of the first upper base.
[0035] In some embodiments, the system 50 comprises a second bar pair 522 , which comprises a third bar 504 and a fourth bar 506 . The third bar 504 has a first end and a second end. The first end pivotably connects to the first interior 112 side of the second bottom base 110 and the second end pivotably connects to the first interior side 222 of the third upper base 220 . The fourth bar 506 has a first end and a second end. The first end pivotably connects to the first interior side 122 of the lower third base 120 and the second end pivotably connects to the first interior side 212 of the second upper base 210 .
[0036] In some embodiments, the system 50 comprises a third bar pair 524 , which comprises a fifth bar 508 and a sixth bar 510 . The fifth bar 508 has a first end and a second end. The first end pivotably connects to the first exterior 126 side of the third bottom base 120 and the second end pivotably connects to the first exterior side 236 of the fourth upper base 230 . The sixth bar 510 has a first end and a second end. The first end of the sixth bar 510 pivotably connects to the first exterior side 136 of the lower fourth base 130 and the second end pivotably connects to the first exterior side 226 of the third upper base 220 .
[0037] In some embodiments, the system 50 comprises a fourth bar pair 526 , which comprises a seventh bar 512 and an eighth bar 514 . The seventh bar 512 has a first end and a second end. The first end of the seventh bar 512 pivotably connects to the second interior 134 side of the fourth bottom base 130 and the second end pivotably connects to the second interior side 204 of the first upper base 200 . The eighth bar 514 has a first end and a second end. The first end of the eighth bar 514 pivotably connects to the second interior side 104 of the lower first base 100 and the second end pivotably connects to the second interior side 234 of the fourth upper base.
[0038] In some embodiments, the first lower base is disposed directly below the first upper base, the second lower base is disposed directly below the second upper base, the third lower base is disposed directly below the third upper base, and the fourth lower base is disposed directly below the fourth upper base.
[0039] In some embodiments, in a folded position, the first ends of the bars are pushed closer together. In an expanded position, the first ends of the bars are pushed farther apart, see for example, FIG. 4 . In some embodiments, the respective two bars of each bar pair slide pass each other on a same plane. In some embodiments, as an option, the respective two bars of each bar pair are pivotably hinged at their respective mid-regions (e.g., 530 , 532 , 534 , and 536 ).
[0040] In some embodiments, the system 50 may be extended beyond four bases with additional bases. For example, the first interior side 102 of the first base 100 may be linked to an additional upper base 162 and the first interior side 202 of the upper base 200 may be linked to an additional lower base 160 via a pair of bars in a similar fashion to the first, second, third and fourth pair of bars of the system.
[0041] Referring now to FIG. 5 , FIG. 6 and FIG. 7 , the present invention also features an expandable hydroponic growing system 55 . In some embodiments, the system 55 comprises a first lower base component 1000 , a second lower base component 1010 , a third lower base component 1020 and a fourth lower base component 1030 . Each of the lower base components has a first interior side (e.g., 1002 , 1012 , 1022 , 1032 ), a second interior side ( 1004 , 1014 , 1024 , 1034 ), a first exterior side ( 1006 , 1016 , 1026 , 1036 ) and a second exterior side ( 1008 , 1018 , 1028 , 1038 ). In some embodiments, the lower base components are arranged in a rectangle configuration 3000 with respect to each other. For example, the first lower base component 1000 is at a first corner 3010 of the rectangle, a second lower base component 1010 is at a second corner 3020 of the rectangle, a third lower base component 1020 is a third corner 3030 of the rectangle and a fourth lower base component 1030 is at a fourth corner 3040 of the rectangle configuration.
[0042] In some embodiments, the interior side of a base (or a base component) is the side of the base that faces another base (or base component) within the imaginary rectangle, e.g., 300 or 3000 , or 400 or 4000 . For example, the first interior side 102 of first base 100 faces first interior side 132 of fourth base 130 , etc.
[0043] In some embodiments, the system 55 further comprises a first upper base component 2000 , a second upper base component 2010 , a third upper base component 2020 and a fourth upper base component 2030 . In some embodiments, each upper base components has a first interior side (e.g., 2002 , 2012 , 2022 , 2032 ), a second interior side (e.g., 2004 , 2014 , 2024 , 2034 ), a first exterior side ( 2006 , 2016 , 2026 , 2036 ) and a second exterior side ( 2008 , 2018 , 2028 , 2038 ). In some embodiments, the upper base components are arranged in a rectangle configuration 4000 with respect to each other. For example, the first upper base component 2000 is at a first corner 4010 of the rectangle, a second upper base component 2010 is at a second corner 4020 of the rectangle, a third upper base component 2020 is a third corner 4030 of the rectangle and a fourth upper base component 230 is at a fourth corner 4040 of the rectangle configuration.
[0044] In some embodiments, the system 55 comprises a first connector pair 5020 , which comprises a first connector 5000 and a second connector 5002 . In some embodiments, the first connector 5000 has a first end and a second end. The first end pivotably connects to the second interior side 1004 of the first lower base component The second end of the first connector pivotably connects the first interior side 2012 of the second upper base component. The second connector 5002 has a first end and a second end, wherein the first end of the second connector pivotably connects to the first interior side 1012 of the second lower base component, and the second end pivotably connects to the second interior side 2004 of the first upper base component;
[0045] In some embodiments, the system 55 comprises a second connector pair 5022 , which comprises a third connector 5004 and a fourth connector 5006 . The third connector 5004 has a first end and a second end. The first end pivotably connects to the second interior side 1014 of the second lower base component. The second end of the third connector pivotably connects the second interior side 2024 of the third upper base component. The fourth connector 5006 has a first end and a second end. The first end pivotably connects to the second interior side 1024 of the third lower base component. The second end pivotably connects to the second interior side 2014 of the second upper base component;
[0046] In some embodiments, the system 55 comprises a third connector pair 5024 , which comprises a fifth connector 5008 and a sixth connector 5010 . For example, the fifth connector 5008 having a first end and a second end. The first end pivotably connects to the first interior side 1022 of the third lower base component. The second end of the fifth connector pivotably connects the second interior side 2034 of the fourth upper base component. The sixth connector 5010 has a first end and a second end. The first end of the sixth connector pivotably connects to the second interior side 1034 of the fourth lower base component. The second end pivotably connects to the first interior side 2022 of the third upper base component.
[0047] In some embodiments, the system 55 comprises a fourth connector pair 5026 , which comprises a seventh connector 5012 and an eighth connector 5014 . For example, the seventh connector 5012 has a first end and a second end. The first end pivotably connects to the first interior side 1032 of the fourth lower base component. The second end of the seventh connector pivotably connects the first interior side 2002 of the first upper base component. The eighth connector 5014 has a first end and a second end. The first end pivotably connects to the first interior side 1002 of the first lower base component. The second end pivotably connects to the first interior side 2032 of the fourth upper base component
[0048] In some embodiments, the rectangle configuration 3000 / 4000 is a square configuration. In some embodiments, when the rectangle configuration is a square configuration, the bar pairs are of the same length.
[0049] In some embodiments, the first lower base component 1000 is disposed directly below the first upper base component 2000 , the second lower base component 1010 is disposed directly below the second upper base component 2010 , the third lower base component 1020 is disposed directly below the third upper base component 2020 , and the fourth lower base component 1030 is disposed directly below the fourth upper base component 2030 .
[0050] In some embodiments, in a folded position, the first ends of the bars are pushed closer together, and in an expanded position, the first ends of the bars are pushed farther apart. In some embodiments, the respective two bars of each bar pair slide pass each other on a same plane. In some embodiments, optionally, the respective two bars of each bar pair are pivotably hinged at their respective mid regions (e.g., 5030 , 5032 , 5034 , 5036 ).
[0051] In some embodiments, the system 55 may be extended beyond four base components with additional base components. For example, the first interior side 1002 of the first base component 1000 may be linked to an additional upper base component 1062 and the first interior side 2002 of the upper base component 2000 may be linked to an additional lower base component 1060 via a pair of connectors in a similar fashion to the first, second, third and fourth pair of connectors of the system.
[0052] In some embodiments, one or more of the base components comprise an outwardly extending tab (see FIG. 5 ). In some embodiments, the tab is perpendicular to the surface that it attaches to or perpendicular to a tangent line at the point where it attaches to the base. The tab may be a location connectors pivotably attach to the base components.
[0053] In some embodiments, one or more of the upper bases (or base components) comprises a hollow opening. For example, a plant may be secured in the hollow opening, wherein leaves of the plant exit the upper portion of the hollow opening and root of the plant exits the lower portion of the opening, see for example FIG. 4 , FIG. 10 and FIG. 11 .
[0054] In some embodiments, the upper bases (or base components) comprise a buoyancy component to allow the upper bases to float in a liquid, for example water. The buoyancy component may have its buoyancy from the shape of the component. For example, the shape may be like that of a boat, where there is a deep wall that keeps water out and allows the buoyancy component to float like a boat, see for example FIG. 10 and FIG. 11 .
[0055] In some embodiments, the upper bases (or base components) are secured to a buoyancy component to allow the upper bases to float in a liquid, for example water. In some embodiments, the buoyancy component derives its floating characteristics from the material that it is constructed from. Materials which float in a liquid, e.g., water, that can be used to form a buoyancy component are well known in the art.
[0056] In some embodiments, the lower bases (or base components) comprise a buoyancy component or is secured to a buoyancy component to allow the lower bases to float in a liquid, for example water. In some embodiments, the buoyancy of the lower bases (or base components) is less than that of the buoyancy of the upper bases (or base components) so that the expandable hydroponic growing system can float in a liquid (e.g., water) with the upper bases (or base components) being closer to the liquid (e.g., water) surface, and the lower bases (or lower base components) floating below the upper bases (or base components). In some embodiments, the buoyancy from the lower bases (or base components) pushes the lower bases (or base components) upwards, which causes the present hydroponic system to be biased in an expanded position. In practice, the extent of which the present hydroponic system is expanded may be controlled by a restriction component, such as the size of the pond that the hydroponic system is disposed in or a rope that is tied around the bases (base components) of the system.
[0057] The upper and lower bases or base components of the present system are not limited to any geometrical configurations. In some embodiments, one or more of the upper bases (or base components) has a cubical shape, see for example FIG. 1 .
[0058] In some embodiments, one or more of the lower bases (or base components) has a cubical shape see for example FIG. 1 .
[0059] In some embodiments, one or more of the upper bases (or base components) has a cylindrical shape, see for example FIG. 4 and FIG. 5 .
[0060] In some embodiments, one or more of the lower bases (or base components) has a cylindrical shape, see for example FIG. 9 .
[0061] Various modifications of the invention, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference cited in the present application is incorporated herein by reference in its entirety.
[0062] Although there has been shown and described the preferred embodiment of the present invention, it will be readily apparent to those skilled in the art that modifications may be made thereto which do not exceed the scope of the appended claims. Therefore, the scope of the invention is only to be limited by the following claims.
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An expandable hydroponic growing system comprising a multiple of upper bases, lower bases and bars connecting the bases in a fashion that the upper bases (and lower bases) can be conveniently pulled together or pushed farther apart.
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PRIORITY CLAIM
This application claims priority to U.S. Provisional Patent Application Ser. No. 62/067,065, filed Oct. 22, 2014. The above referenced application is incorporated herein by reference as if restated in full.
All references cited herein, including but not limited to patents and patent applications, are incorporated by reference in their entirety.
BACKGROUND
Camptothecin is a topoisomerase I inhibitor originally isolated from the bark and stem of Camptothecaacuminata (Camptotheca, Happy tree), a tree native to China.
Camptothecin analogs having anti-cancer and anti-tumor properties are described in U.S. Pat. No. 6,136,978, hereby incorporated by reference in its entirety. In one aspect, these camptothecin analogs have the following general structure (Formula I) described in U.S. Pat. No. 6,136,978 (“'978 patent”):
where R 1 -R 11 are defined as in the '978 (e.g., col. 3, line 35—col. 4, line 65).
Of particular interest is a camptothecin analog known as AR-67 or DB-67 ((20S)-10-hydroxy-7-trimethylsilylcamptothecin)) (Formula II) having the structure shown below:
Topoisomerases regulate the winding and unwinding of DNA strands. Camptothecins are DNA topoisomerase I inhibitors which stabilize single-strand breaks in DNA leading to apoptosis and cell death. A general scheme for synthesizing the compound of Formula I is provided in FIG. 1 of the '978 patent.
A known general scheme for synthesizing AR-67 (the compound of Formula II is shown below:
In this synthesis method, the starting material, 10-hydroxycamptothecin, is a natural product obtained from Camptothecaacuminate that requires special handling due to toxicity. In addition, the cost of this starting material is high. Thus, use of known synthesis methods for making the Camptothecin analogs of Formula I and, in particular, AR-67, may be cost prohibitive due the cost of the starting materials and special facilities and handling needed for the starting materials and intermediaries.
What is needed is an improved, less costly method for making, forming, or synthesizing the compounds of Formula I, including AR-67, with higher yields, fewer impurities, lower cost, and less risk.
SUMMARY
In one aspect, methods are described herein for synthesis of the compound of Formula I:
where R 1 -R 11 are defined as in the '978 (e.g., col. 3, line 35—col. 4, line 65).
In another aspect, methods are described herein for the synthesis of the compound of
Formula II:
In yet one aspect, an exemplary method of synthesizing the compounds of Formula I and Formula II is shown in FIG. 1 .
In this aspect, synthetic materials can be used as starting materials (e.g., Propane-1,3-dithiol and 3-hydroxybenzaldehyde) resulting in lower risk of toxicity. In another aspect, synthesis methods described herein result in yields of Formula I or Formula II of greater than about 0.4%.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an exemplary eight step synthesis scheme for AR-67;
FIG. 2 shows an exemplary NMR spectra for the synthesis of AP4622-1 in step 1 of the synthesis scheme of FIG. 1 ;
FIG. 3 shows an exemplary NMR spectra for the synthesis of AP4622-2 in step 2 of the synthesis scheme of FIG. 1 ;
FIG. 4 shows an exemplary NMR spectra for the synthesis of AP4622-3 in step 3 of the synthesis scheme of FIG. 1 ;
FIG. 5 shows an exemplary NMR spectra for the synthesis of AP4622-4 in step 4 of the synthesis scheme of FIG. 1 ;
FIG. 6 shows an exemplary NMR spectra for the synthesis of AP4622-5 in step 5 of the synthesis scheme of FIG. 1 ;
FIG. 7 shows an exemplary NMR spectra for the synthesis of AP4622-6 in step 6 of the synthesis scheme of FIG. 1 ;
FIG. 8 shows an exemplary NMR spectra for the synthesis of AP4622 in step 7 of the synthesis scheme of FIG. 1 ;
FIG. 9 shows an exemplary LC-MS spectra for the synthesis of AP4622 in Step 7 of the synthesis scheme of FIG. 1 ;
FIG. 10 shows an exemplary NMR spectra for the synthesis of AR-67 in step 8 of the synthesis scheme of FIG. 1 ;
FIG. 11 shows an exemplary HPLC spectra for the synthesis of AR-67 in step 8 of the synthesis scheme of FIG. 1 ;
FIG. 12 shows an exemplary chiral HPLC spectra for the synthesis of AR-67 in step 8 of the synthesis scheme of FIG. 1 ; and
FIG. 13 shows an exemplary NMR spectra for the synthesis of AR-67-RAC in step 9 of the synthesis scheme of FIG. 1 ;
DETAILED DESCRIPTION
Before describing several exemplary aspects described herein, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The aspects described herein are capable of being practiced or being carried out in various ways. For example, the compound(s) at each step of the exemplary synthesis method can be converted to another compound by a variety of methodologies known to those skilled in the art in addition to the methods described herein (e.g., alternate reagents, temperatures, reaction time, and stirring times).
Aspects described herein provide methods and systems for synthesis of the compounds of Formula I and the synthesis of AR-67 (Formula II). In one aspect, the methods and systems use synthetic and significantly less toxic starting materials than previous methods and systems and result in increased yield with fewer impurities. In another aspect, intermediates in the synthesis of camptothecin analogs are provided.
In one aspect, step 1 of an exemplary synthesis method comprises:
In step 1, Propane-1,3-dithiol (21.64g, 200 mmol) is added dropwise to a solution of iodine (5.08 g, 20 mmol) and 3-hydroxybenzaldehyde (24.42 g, 200 mmol) in CHCl 3 (500 mL) at room temperature (RT). The reaction mixture is stirred for 1 hour at RT, then quenched by addition of a solution of Na 2 SO 3 (5%, 150 mL) and extracted with DCM (250 mL×2).
The combined organic layers can be dried over MgSO4, concentrated in vacuo and purified by flash chromatography (EA: Hex=1: 5) to give AP4622-1 as a white powder, 34.82 g, 82% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 7.20 (t, J=7.8 Hz, 1 H), 7.02 (d, J=7.8 Hz, 1 H), 6.96 (d, J=2.1 Hz, 1 H), 6.77 (dd, J=7.8, 2.1 Hz, 1H), 5.12 (s, 1 H), 4.89 (s, 1 H), 3.02 (m, 2 H), 2.92 (m, 2 H), 2.16 (m, 1 H), 1.95 (m, 1 H) ( FIG. 2 ).
In this aspect, step 2 of an exemplary synthesis method comprises:
In step 2, under argon, a solution of TBSCl (120 mmol, 18.09 g) in DCM (50 mL) is added dropwise to a solution of AP4622-1 (100 mmol, 21.23 g) and imidazole (130 mmol, 8.85 g) in DCM (250 mL) at 0° C. Next, the reaction mixture is stirred overnight at RT, washed with water (200 mL×2), dried over MgSO 4 and concentrated in vacuo. The residue can be purified by flash chromatography (EA: Hex=1: 20) to give AP4622-2 as a pale yellow oil, 29.07g, 89% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 7.20 (t, J =7.8 Hz, 1 H), 7.06 (d, J=7.8 Hz, 1 H), 6.98 (t, J=1.8 Hz, 1 H), 6.77 (dd, J=7.8, 1.8 Hz, 1 H), 5.12 (s, 1 H), 3.07 (m, 2 H), 2.94 (m, 2 H), 2.17 (m, 1 H), 1.98 (m, 1 H), 1.02 (s, 9 H), 0.23 (s, 6 H) ( FIG. 3 ).
In this aspect, step 3 of an exemplary synthesis method comprises:
In step 3, under argon, n-BuLi (43.6 mL, 2.2 M in hexane, 96mmol) is added dropwise to a solution of AP4622-2 (26.13 g, 80 mmol) in THF (350 mL) at -78 ° C. The resulting mixture can be stirred for additional 1 h at −78° C. followed by addition of TBSC1 (16.58 g, 110 mmol) and additional stirring for 10 hours at RT. A saturated solution of NH 4 Cl (150 mL) can beadded to quench the reaction. The mixture can be extracted with EA (Ethyl Acetate) (250 mL×2) and the combined organic layers can be dried over MgSO 4 , concentrated in vacuo, and purified by flash chromatography (EA: Hex=1: 50) to give AP4622-3 as a colorless oil, 15.87 g, 45% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 7.57 (d, J=7.8 Hz, 1 H), 7.50 (d, J=2.1 Hz, 1 H), 7.21 (t, J=7.8 Hz, 1 H), 6.67 (dd, J=7.8, 2.1 Hz, 1 H), 2.83 (m, 2 H), 2.42 (m, 2 H), 2.07 (m, 1 H), 1.88 (m, 1 H), 1.00 (s, 9 H), 0.83 (s, 9 H), 0.23 (s, 6 H), 0.16 (s, 9 H) ( FIG. 4 ).
In this aspect, step 4 of an exemplary synthesis method comprises:
In step 4, a solution of AP4622-3 (4.41 g, 10 mmol) in acetone (35 mL is added dropwise to a solution of NBS (8.90 g, 50 mmol) in acetone/water (60 mL/50 mL) at 0 ° C. During the addition, the pH is maintained to neutral by simultaneous addition of Et 3 N. The resulting mixture is stirred for additional 0.5 h at 0° C. A solution of Na 2 SO 3 (5%, 150 mL) is added to quenched the reaction. The mixture was extracted with EA (100 mL×3). The combined organic layers were dried over MgSO 4 , concentrated in vacuo and purified by flash chromatography (EA: Hex=1: 100) to give AP4622-4 as a yellow oil, 3.02 g, 86% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 7.41 (d, J=7.8 Hz, 1 H), 7.32 (t, J=7.8 Hz, 1 H), 7.23 (s, 1 H), 6.99 (d, J=5.7 Hz, 1 H), 0.99 (s, 9 H), 0.96 (s, 9 H), 0.36 (s, 6 H), 0.21 (s, 9 H) ( FIG. 5 ).
In this aspect, step 5 of the exemplary synthesis method comprises:
In step 5, tetrabutylammonium fluoride trihydrate (3.155 g, 10.0 mmol) is added to a solution of AP4622-4 (1.753 g, 5.0 mmol) in MeOH (20 mL) and the reaction mixture is stirred for 2 hours at RT. The solvent was evaporated in vacuo. The residue is diluted with ethylene acetate (EA) (100 ml), washed with water (50 mL×3), dried over MgSO 4 , and concentrated in vacuo to provide AP4622-5 as a yellow powder, 1.075 g, 91% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 7.40 (m, 1 H), 7.32 (m, 2 H), 7.04 (d, J=5.4 Hz, 1 H), 6.04 (s, 1 H), 0.96 (s, 9 H), 0.37 (s, 6 H) ( FIG. 6 ).
In this aspect, step 6 of the exemplary synthesis method comprises:
In step 6, HNO 3 (35%, 1.44 g. 8.0 mmol) is added dropwise to a solution of AP4622-5 (945 mg, 4.0 mmol) in HOAc (10 mL) at 16° C., the reaction mixture is stirred for 3 h at RT, poured into ice water (50 mL), and extracted with ethylene acetate (30 mL×3). The combined organic layers are washed with water (20 mL) and brine (20 mL), dried over MgSO 4 , concentrated in vacuo, and purified by flash chromatography (EA: Hex =1: 6) to give AP4622-6 as a yellow powder, 304 mg, 27% yield. 1 H NMR (300 MHz, CDCl 3 ) δ 8.07 (d, J=9.0 Hz, 1 H), 7.99 (s, br, 1 H), 6.90 (dd, J=2.7, 9.0 Hz, 1 H), 6.51 (d, J=2.7 Hz, 1 H), 0.96 (s, 9 H), 0.19 (s, 6 H) ( FIG. 7 ).
In this aspect, step 7 of the exemplary synthesis method comprises:
In step 7, tin powder (594 mg, 5.0 mmol) is added to a mixture of AP4622-6 (281 mg, 1.0 mmol) and HCl (3 M, 10 mL) and the reaction mixture is stirred for 3 hours at 85° C. After cooling down, the mixture is extracted with dichloromethane (DCM) (20 mL×3), the combined organic layers are neutralized with Et 3 N, dried over MgSO 4 , concentrated in vacuo, and purified by flash chromatography (EA: Hex =1: 10) to give AP4622-7 as a yellow powder, 53 mg, 21% yield. 1 H NMR (300 MHz, DMSO-d 6 ) δ 8.76(s, 1 H), 7.12 (d, J=2.7 Hz, 1 H), 6.76 (m, 3 H), 6.60 (d, J=8.7 Hz, 1 H), 0.91 (s, 9 H), 0.31 (s, 6 H) ( FIG. 8 ). LCMS: M+1=252 ( FIG. 9 ).
In this aspect, step 8 of the exemplary synthesis method comprises:
In step 8, a solution of AP4622 (2.01 g, 8.0 mmol), s-Trione (1.84 g, 7.0 mmol) and TsOH (10 mg, cat) in HOAc (25 mL) is stirred for 24 hours at 110° C. After cooling down, the solvent is removed in vacuo. The residue is purified by flash chromatography (MeOH: DCM=1: 100) to give AR67 as a yellow powder, 950 mg, 28% yield. 1 H NMR (300 MHz, DMSO-d 6 ) δ 10.35 (s, 1 H), 8.02 (d, J=9.0 Hz, 1 H), 7.56 (s, 1 H), 7.39 (d, J=9.0 Hz, 1 H), 7.26 (s, 1 H), 6.48 (s, 1 H), 5.40 (s, 2 H), 5.21 (s, 2 H), 1.85 (m, 2 H), 0.96 (s, 9 H), 0.87 (t, J=7.2 Hz, 3 H), 0.65 (s, 6 H)( FIG. 10 ). HPLC Purity: 99.1% ( FIG. 11 ). Chiral HPLC purity: >99% ( FIG. 12 ).
In this aspect, step 9 of the exemplary synthesis method comprises:
In this step, a solution of AP4622 (2.01 g, 8.0 mmol), Trione (1.84 g, 7.0 mmol) and TsOH (10 mg, cat) in HOAc (25 mL) is stirred for 24 h at 110° C. After cooling down, the solvent is removed in vacuo. The residue was purified by flash chromatography (MeOH: DCM =1: 100) to give AP4622-RAC (racemic) as a yellow powder, 1.04 g, 31% yield. 1 H NMR (300 MHz, DMSO-d 6 ) δ 10.35 (s, 1 H), 8.03 (d, J=9.0 Hz, 1 H), 7.56 (d, J =2.4 Hz, 1 H), 7.38 (dd, J=2.4, 9.0 Hz, 1 H), 7.26 (s, 1 H), 6.48 (s, 1 H), 5.40 (s, 2 H), 5.21 (s, 2 H), 1.85 (m, 2 H), 0.96 (s, 9 H), 0.87 (t, J=7.2 Hz, 3 H), 0.65 (s, 6 H) ( FIG. 13 ).
Although the above description refers to particular aspects, it is to be understood that these aspects are merely illustrative. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods described herein. Thus, it is intended that the present description include modifications and variations that are within the scope of the appended claims and their equivalents.
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Methods and systems for making camptothecin analogs and intermediates are provided. Aspects include safer and lower cost methodologies for making camptothecin analogs and intermediates from synthetic materials. In another aspect, the methods and systems can achieve a yield of the camptothecin analogs greater than about 0.4%.
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FIELD OF THE INVENTION
[0001] The invention concerns a progressiveness element for a clutch friction device, in particular for a motor vehicle, a clutch friction device comprising such a progressiveness element and a method of manufacturing such a friction device.
BACKGROUND OF THE INVENTION
[0002] A motor vehicle clutch makes it possible to selectively connect and disconnect an engine flywheel and a gearbox input shaft. To this end, the clutch comprises conventionally a mechanism, rotationally fixed to the engine flywheel, and a friction device rotationally fixed to the input shaft of the gearbox.
[0003] A friction device comprises a metal disc pieced at its centre. First and second linings in the form of flat rings are fixed to the periphery of each of the faces of the disc.
[0004] The mechanism comprises a pressure plate and a reaction plate, coaxial with the friction device, facing the first and second linings respectively. It also comprises a diaphragm, also coaxial with the friction device, the actuation of which brings the pressure and reaction plates closer together or further apart between engaged and disengaged positions.
[0005] In the engaged position, the plates sufficiently grip the linings to allow a transmission of torque between the mechanism and the friction device.
[0006] In the disengaged position, on the other hand, the plates are sufficiently separated for the mechanism and the friction device to be mechanically decoupled and be able to turn independently of each other.
[0007] Apart from the selective transmission of torque, a friction device must also provide the progressiveness of this transmission when the vehicle starts up and during gear changes. This progressiveness contributes to driving comfort, limits noise and improves the distribution of forces on the linings and plates.
[0008] To this end, the disc can for example be locally deformable in line with the linings.
[0009] As described in EP 0 504 033, an elastic cellular material can also be disposed between the linings and the disc in order to ensure the progressiveness of the transmission. The cellular material is formed from materials belonging to the group comprising elastomer foams, such as silicone foams and fluorinated rubber foams, thermoplastic materials moulded with gas blown in in order to create a porosity, such as polyamides, polyether ketones, or thermosetting resin foams having sufficient flexibility such as modified epoxy resins.
[0010] EP 0 504 033 also describes a second embodiment in which the disc is formed by assembling first and second shields. Each shield, in the general form of a disc, has a flat central connecting part, an annular flat peripheral part extending radially parallel to the central part, and an intermediate part connecting the central part and the peripheral part while providing an axial offset of the peripheral part with respect to the central part. The central parts of the shields, with a central recess, are contiguous.
[0011] The linings are fixed to the external faces of the peripheral parts.
[0012] The intermediate parts of the first and second shields are conformed so that, by coaxially fixing together the central parts to form the disc, the peripheral parts are separated axially from each other and form with the intermediate parts a peripheral groove or “slot” opening out radially.
[0013] The elastic cellular material at least partially fills the peripheral slot of the disc. This material thus fulfils the progressiveness function without interfering with the fixing of the linings to the disc.
[0014] EP 0 419 329 also describes a friction device comprising a disc similar to the disc of the second embodiment of EP 0 504 033. Progressiveness is ensured by means of a plurality of protuberances made from a silicone-based rubber that extend radially in the peripheral slot.
[0015] Finally, EP 0 446 098 describes a friction device similar to that of EP 0 419 329 but where the protuberances are produced in the form of loops.
[0016] All the “progressiveness elements” used up to now and in the form of a buffer made from an elastic material interposed between the two linings have the drawback of taking a long time to implement. This is because the duration of polymerisation of the materials used generally exceeds ten minutes and may even be as much as a day. These progressiveness elements are therefore unsuited to industrial production at high rate.
[0017] There thus exists a need for a novel progressiveness element that can be interposed between the two linings and that is better suited to the methods for the industrial manufacture of friction devices. The aim of the invention is to satisfy this need.
SUMMARY OF THE INVENTION
[0018] According to the invention, this aim is achieved by means of a progressiveness element consisting at least partly, preferably totally, of an addition silicone (or “addition polysiloxane”).
[0019] Advantageously, the polymerisation of such a silicone is very rapid.
[0020] The preferred addition silicones are the Dow Corning® 3-6096 silicone elastomer from the company Dow Corning and the Addisil 6100 silicone elastomer from GE Bayer Silicones GmbH & Co KG (Germany).
[0021] Preferably, the progressiveness element also has one or more of the following characteristics.
[0022] The silicone is a single-component silicone. Preferably, the polymerisation results from heating, preferably by means of infrared radiation.
[0023] The silicone is a silicone of the polydimethylsiloxane type, containing in particular vinyl groups.
[0024] The silicone is an adhesive silicone. Preferably the silicone is sufficiently adhesive to limit the gaping of the linings in service, that is to say their separation from each other during normal use of the friction device. In this case the progressiveness element therefore also fulfils an anti-gaping function preventing the two linings from moving apart from each other in an undesired fashion.
[0025] The silicone has a polymerisation temperature of between 130° and 200° C., preferably approximately 150° to 180° C.
[0026] The invention also concerns a clutch friction device, in particular for a motor vehicle, comprising a disc and a progressiveness element according to the invention.
[0027] Preferably, the friction device also has one or more of the following characteristics.
[0028] A progressiveness element according to the invention is disposed, preferably adhesively bonded, between a lining fixed to the disc and the disc. Preferably, a progressiveness element according to the invention is disposed, preferably adhesively bonded, between each of the linings fixed to the disc and the disc.
[0029] Preferably again, at least one progressiveness element according to the invention makes a lining adhere to the disc. Its function is therefore dual: fixing the lining to the disc and ensuring progressiveness of the friction device.
[0030] A progressiveness element according to the invention is disposed, preferably adhesively bonded, in a radially emerging peripheral slot provided on the disc. Preferably again, this slot is formed by assembling two shields, for example as described in EP 0 419 329 or EP 0 504 033.
[0031] Finally, the invention concerns a method of manufacturing a clutch friction device, in particular for a motor vehicle, the friction device comprising first and second shields assembled in a friction disc and providing a radially emerging peripheral slot, and first and second linings fixed to external faces of the first and second shields.
[0032] According to the invention, this method comprises the following steps:
[0033] A) application of an adhesive to an internal face of the first lining and affixing of the said internal face to the external face of the first shield, and
[0034] B) independently of step A), preferably subsequently to step A), application, to a surface of the first shield intended to delimit the peripheral slot, of a composition comprising an addition silicone able to polymerise under the same conditions as the adhesive in order to form a progressiveness element according to the invention, and then fitting of the second shield against the first shield, and
[0035] C) after steps A) and B), simultaneous polymerisation of the adhesive and silicone.
[0036] Advantageously, the setting of the adhesive and silicone are therefore simultaneously, which simplifies the manufacturing method.
[0037] Preferably, the silicone used is a single-component silicone whose polymerisation commences only as a consequence of heating. Unlike traditional silicones used, the polymerisation commences as soon as the clutch friction device is assembled, the silicones according to the invention afford great flexibility in use. It is in particular possible to envisage the intermediate storage of the assembled or partially assembled parts, the silicone not being polymerised, and this as long as the said parts are not raised to the polymerisation initiation temperature.
[0038] The silicone can also be chosen to serve as an adhesive for fixing at least one of the linings to the disc. In other words, the adhesive for fixing at least one of the linings is the same material as the silicone forming the progressiveness element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Other characteristics and advantages of the present invention will emerge from a reading of the following description and an examination of the accompanying drawing, in which:
[0040] FIG. 1 depicts an exploded view of a friction device according to the invention, according to a first embodiment;
[0041] FIGS. 2 a to 2 e depict views in radial section of a detail of various embodiments of a friction device according to the invention;
[0042] FIG. 3 depicts the progressiveness curves for a friction device according to invention at various steps of a load stressing test.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] In the various figures, identical references are used for designating identical or similar components.
[0044] FIG. 1 depicts a friction device 10 .
[0045] The friction device 10 of axis A comprises a metal disc 12 , pieced at its centre, thus having the general shape of a flat annulus. First and second linings, 14 and 16 respectively, in the form of a flat ring, are fixed to the periphery of the first and second lateral external faces 18 and 20 of the disc 12 , respectively.
[0046] External faces 22 and 24 of the linings 14 and 16 are intended to cooperate with a pressure plate and a reaction plate (not shown), respectively.
[0047] The disc 12 comprises first 25 and second 26 shields (or “shims”), substantially flat and parallel, in the form of a pieced disc. The internal faces 27 and 28 of the first 14 and second 16 friction linings are fixed, for example by adhesive bonding or rivets, to the external faces 18 and 20 of the first 25 and second 26 shields, respectively. In a variant, a shield and the corresponding lining can be formed in a single piece, for example by injection moulding.
[0048] The first 25 and second 26 shields can for example consist of a composite material or steel preferably comprising 0.68% or 0.75% carbon (designated respectively XC68 and XC75 according to the French AFNOR standard). They are substantially annular, coaxial and of axis A, and separated axially from each other by means of a progressiveness element 29 taking the form of a plurality of concentric beads 30 of axis A interposed between the two internal faces 31 and 32 of the shields 25 and 26 .
[0049] Preferably, the progressiveness element 29 comprises three beads 30 .
[0050] The friction device 10 also comprises first and second connecting torques, 33 and 34 respectively, made in one piece with the first and second shields 25 and 26 , respectively, the second connecting torques 34 being inclined with respect to the plain of the shields towards the mid plane of the friction device. The free end of each first connecting torque 33 is conformed and arranged so as to be connected to the surface of a corresponding second torque 34 when the first and second shields move axially with respect to each other, in particular as a consequence of a gripping of the friction device between the pressure plate and the reaction plate. The first and second shields 25 and 26 then move parallel with respect to each other by screwing along their axis A. The optional presence of the connecting torques 33 and 34 advantageously improves the contact of the friction linings with the pressure and reaction plates.
[0051] According to the invention, the progressiveness element 29 is, at least partially, an addition silicone. Part of the bead 30 , an entire bead 30 , or preferably all the beads 30 are made from an addition silicone.
[0052] The silicone elastomers are the result of a cross-linking, that is to say an addition or condensation polymerisation that binds the polymer chains to each other. The degree of cross-linking and any reinforcement with mineral fillers determine the final mechanical properties of the elastomer.
[0053] There are “condensation silicones” and “addition silicones”.
[0054] Condensation silicones are obtained by means of a so called “condensation” reaction during which, in order to form a silicone molecule, two or more molecules are combined, generating a by-product. Typically, such a condensation reaction involves, in addition to the polymers, cross-linking agents and possibly reinforcing fillers, water and a catalyst, for example titanium or tin. The condensation reaction is slow, generally taking several hours, whether the system be single-component or two-component.
[0055] Addition silicones result from a so-called “addition” reaction in which a silicone molecule is formed by the juxtaposition of two or more others without the formation of a by-product. Typically, such an addition reaction involves, in addition to the polymers, cross-linking agents and possibly reinforcing fillers, and a catalyst, in particular a noble metal such as for example platinum, rhodium, iridium or palladium. The presence of traces of platinum, in particular around 1 to 20 ppm by weight, in the silicone normally indicates that a silicone is an addition silicone. The addition reaction is rapid, generally taking a few minutes, whether the system be single-component or two-component.
[0056] Similar to addition silicones, peroxide cross-linking silicones decompose at high temperature in order to produce highly reactive free radicals that will promote the formation of chemical bonds between the linear chains that constitute the polymer matrix. Peroxides have been used for decades in the field of solid silicones. By-products are formed, with an unpleasant odour, and not always inoffensive. In some cases legal restrictions can be expected.
[0057] Addition silicones afford many advantages compared with the peroxide cross-linking ones:
[0058] there are no by-products generated (that is to say no risk of toxic products)
[0059] there is more rapid polymerisation (up to 50%).
[0060] The preferred addition silicones are the Dow Corning® 3-6096 silicone elastomer, Addisil 6100 and Rhodorsil® ESA 7142.
[0061] The Dow Corning® 3-6096 silicone elastomer from the company Dow Corning is a single-component addition silicone in the form of a black paste. It polymerises under heat, in less than 5 minutes at 180° C.
[0062] The Addisil 6100 silicone from GE Bayer Silicones GmbH & Co. KG (Germany) is a polydimethyl siloxane containing vinyl groups with pyrogenic silicic acid. It polymerises in less than 2 minutes at 175° C.
[0063] RHODORSIL® ESA 7142 is a single-component silicone elastomer of the polyaddition type, non-flowing and cross-linking hot. Manufactured by the company Rhodia Silicones s.a.s. (France), it is recommended for the sealing and protection of housings by jointing and filling, as well as for the isolation of electric motors. This adhesive is based on polymethyl vinylsiloxanes, polymethyl hydrogenosiloxanes and silica.
[0064] Constituents other than an addition silicone can be mixed with the latter in order to form a progressiveness element 29 according to the invention.
[0065] FIG. 2 a shows a schematic radial section of a peripheral part of the friction device 10 shown in FIG. 1 , in a zone where the disc 12 does not have any connecting torque.
[0066] Many other embodiments are possible.
[0067] For example, FIGS. 2 b to 2 d show embodiments of the invention in which the first and the second shields 25 and 26 have the general shape of a disc with a central recess, with a flat central part 36 , a flat peripheral part 38 extending as substantially radially parallel to the central part 36 , and an intermediate part 40 connecting the central part 36 and the peripheral part 38 . The linings 14 and 16 are fixed in the external faces 42 of the peripheral parts 38 .
[0068] As in EP 0 504 033, the intermediate parts 40 of the first and second shields 25 and 26 are conformed so as to shift the peripheral parts 38 axially and outwards with respect to the central parts 36 so as to form a radially emerging peripheral slot 44 .
[0069] The progressiveness element 29 according to the invention can be formed by beads 30 disposed inside the slot 44 and pressed between the internal faces 31 and 32 of the peripheral parts 38 . The progressiveness element 29 according to the invention can also be formed by a single bead partially ( FIG. 2 c ) or completely ) FIG. 2 d ) filling the slot 44 .
[0070] The FIG. 2e depicts another embodiment in which a progressiveness element 29 is interposed between each lining 14 and 16 and the disc 12 . Preferably, the progressiveness element 29 also serves to bond the linings to the disc 12 . In this embodiment, the disc 12 is single-piece. The arrangement of the progressiveness element 29 between the linings 14 and/or 16 and the disc 12 is also possible with a disc 12 in two parts 25 and 26 , as described above. In this case, a progressiveness element according to the invention can also be inserted in the peripheral slot 44 .
[0071] The manufacture of the friction device shown in FIGS. 1 and 2 can be carried out in the following manner:
[0072] a) The internal faces 27 and 28 of the linings 14 and 16 are first of all glued, and then they are bonded respectively to the external faces 18 and 20 of the shields 25 and 25 previously prepared for this purpose. This preparation, for example cleaning by means of a solvent and/or the application of a primer, depends on the nature of the adhesive and is well known to persons skilled in the art.
[0073] b) Next the adhesive is polymerised by heating.
[0074] c) Then, according to the recommendations of the manufacturer of the silicone used, the internal faces 31 and 32 of the shields 25 and 26 are cleaned and, if necessary, a primer is applied.
[0075] d) Next addition silicone beads 30 are formed on the internal face 31 . Preferably, the silicone used is a single-component silicone whose polymerisation commences only as a consequence of heating. After having deposited the silicone on the internal face 31 , the shields can therefore be manipulated and transported for as long as necessary. In addition, any risk of undesired polymerisation, for example of traces of silicone on the appliances used for depositing the beads 30 , is avoided. The triggering of the polymerisation can advantageously be perfectly controlled. The use of a single-component silicone is thus well suited to the constraints of industrial production of the friction device.
[0076] e) The internal faces 31 and 32 of the shields 25 and 26 are brought together, arranging them separated from each other by a defined distance less than the silicone extrusion diameter. The silicone deposited on the internal face 31 is thus also in contact with the internal face 32 . Preferably, the shields 25 and 26 are clamped, thus to say they are kept firmly immobilised with respect to each other so that they do not undergo any distortion during the following step.
[0077] f) Depending on the silicone, the material of the beads 30 is then heated so that it polymerises by addition. The heating is preferably carried out by conduction or irradiation by means of infrared radiation. Advantageously, the polymerisation of the addition silicones is rapid.
[0078] According to a variant of the manufacturing method according to the invention, an adhesive is chosen for fixing the linings and an addition silicone for constituting the progressiveness element that have similar polymerisation conditions. For example, the adhesive can be an adhesive of the Araldyte 64 type, which cross-links at 180° C., and the silicone can be a Dow Corning® 3-6096 silicone, Addisil 6100 from Bayer Silicones or Rhodorsil® from Rhodia Silicones s.a.s. In a particular embodiment, in particular in a friction device of the type shown in FIG. 2 e, the silicone can also be chosen to serve as an adhesive for fixing the linings.
[0079] It is then possible to proceed in accordance with step a), and then steps c) to f) described above, that is to say without executing polymerisation of the adhesive (step b)) prior to the polymerisation of the silicone. At step f, the heating of the friction device allows simultaneous setting of the adhesive and silicone. The manufacturing method is advantageously simplified and more economical.
[0080] An axial load stressing test was carried out in order to evaluate the fatigue strength of the progressiveness element according to the invention. This test consists of applying to a friction device of a clutch, cyclically, an axial force corresponding to the maximum rating of this clutch.
[0081] The friction device tested, of the type shown in FIG. 2 a, had an outside diameter of 215 mm. It comprised a progressiveness element made from Dow Corning® 3-6096. The axial force applied was 7300 N.
[0082] FIG. 3 shows the progressiveness curves of this friction device after 0, 600,000, one million and three million cycles. A progressiveness curve represents the reduction in thickness, in millimetres, of a progressiveness element under the effect of a transverse load.
[0083] Very good preservation of the progressiveness curve with the Dow Corning® 3-6096 addition silicone is found. The conventional friction devices whose progressiveness is achieved by the curvature of metallic blades does not offer such good results.
[0084] As now appears clearly, the invention provides a progressiveness element that can be interposed between the two linings (between at least one lining and the friction disc and/or inside a peripheral slot of the disc extending in line with the linings) and that is well suited to industrial manufacturing processes for friction devices. The duration of polymerisation of the progressiveness element is in fact advantageously very short.
[0085] Naturally the present invention is not limited to the embodiments described and shown provided by way of illustrative and non-limitative examples.
[0086] In particular, the form of the disc, the shields, the peripheral slot and the linings, or the nature of the means of fixing the linings, are not limitative.
[0087] In addition, the progressiveness element forming a spring is not necessarily bonded to each of the shields between which it is interposed. It may have any shape. In particular, the beads may be of any shape, closed or not, and be continuous or not. The progressiveness element may also have the form of studs.
[0088] Finally, the peripheral slot does not necessarily extend over the entire periphery of the disc. Preferably, its depth is however sufficient so that it extends in line with the entire bearing surface of the linings on the disc.
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The invention concerns a smooth engagement element of a clutch friction disc, in particular for a motor vehicle, consisting, at least partly in a silicone addition.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 800,505 filed May 25, 1977, abandoned which is in turn a continuation-in-part of Ser. No. 742,967, filed Nov. 17, 1976 now U.S. Pat. No. 4,116,723.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of homogeneous single crystal superalloy articles.
2. Description of the Prior Art
The nickel base super-alloy art area has been extensively investigated for many years, and as a result there are very many issued patents in this area. Some of these disclose alloys in which no intentional additions of cobalt, carbon, boron, or zirconium are made, or alloys in which these elements are optional. These include, for example, U.S. Pat. Nos. 2,621,122; 2,781,264; 2,912,323; 2,994,605; 3,046,108; 3,166,412; 3,188,402; 3,287,110; 3,304,176 and 3,322,534. These patents do not discuss single crystal applications.
U.S. Pat. No. 3,494,709, assigned to the assignee of the present invention, discloses the use of single crystal articles in gas turbine engines. This patent discusses the desirability of limiting certain elements such as boron and zirconium to low levels.
The limitation of carbon to low levels in single crystal superalloy articles is discussed in U.S. Pat. No. 3,567,526 which is also assigned to the present assignee.
U.S. Pat. No. 3,915,761, assigned to the present assignee discloses a nickel base superalloy article produced by a method which provides a hyperfine dendritic structure. As a result of the fineness of the structure, the article may be homogenized in relatively short times.
The conventional nickel base superalloys which are used to fabricate such parts have evolved over the last 30 years. Typically these alloys contain chromium in levels of about 10% primarily for oxidation resistance, aluminum and titanium in combined levels of about 5% for the formation of the strengthening gamma prime phase and refractory metals such as tungsten, molybdenum, tantalum and columbium in levels of about 5% as solid solution strengtheners. Virtually all nickel base superalloys also contain carbon in levels of about 0.1% which acts as a grain boundary strengthener and forms carbides which strengthen the alloy. Boron and zirconium are also often added in small amounts as grain boundary strengtheners.
Most commonly, gas turbine blades are formed by casting and the casting process most often utilized produces parts having equiaxed nonoriented grains. It is well known that the high temperature properties of metals are usually quite dependent upon grain boundary properties, consequently efforts have been made to strengthen such boundaries (for example by the additions discussed previously), or to reduce or eliminate the grain boundaries transverse to the major stress axis of the part. One method of eliminating such transverse boundaries is termed directional solidification and is described in U.S. Pat. No. 3,260,505. The effect of directional solidification is to produce an oriented microstructure of columnar grains whose major axis is parallel to the stress axis of the part and which has minimal or no grain boundaries perpendicular to the stress axis of the part. A further extension of this concept is the utilization of single crystal parts in gas turbine blades. This concept is described in U.S. Pat. No. 3,494,709. The obvious advantage of the single crystal blade is the complete absence of grain boundaries. In single crystals, therefore, grain boundaries are eliminated as potential weaknesses, hence, the mechanical properties of the single crystal are completely dependent upon the inherent mechanical properties of the material.
In the prior art alloy development much effort was devoted to the solution of the problems resulting from grain boundaries, through the addition of elements such as carbon, boron, and zirconium. Another problem which prior art alloy development sought to avoid was the development of deleterious phases after long term exposures at elevated temperatures (i.e. alloy instability). These phases are of two general types. One, such as sigma, is undesirable because of its brittle nature while the other, such as mu, is undesirable because the phase ties up large amounts of the refractory solid solution strengtheners thus weakening the remaining alloy phases. These phases are termed TCP phases for topologically closed packed phases, and one of their common properties is that they all contain cobalt. There are TCP phases which can form in the absence of cobalt but these cobalt free TCP phases contain other elements such as silicon which are not commonly found in nickel base superalloys. While an obvious remedy to control these deleterious phases is the removal or minimization of cobalt, this has not proved practical in prior art alloys for polycrystalline applications. The problem is that if the cobalt is removed or significantly reduced, the carbon combines preferentially with the refractory metals to form M 6 C carbides which are deleterious to the properties of the material as their formation depletes the alloy of the strengthening refractory elements.
U.S. Pat. No. 3,567,526 teaches that carbon can be completely removed from single crystal superalloy articles and that such removal improves fatigue properties.
In single crystal articles which are free from carbon there are two important strengthening mechanisms. The most important strengthening mechanism is the intermetallic gamma prime phase, Ni 3 (Al, Ti). In modern nickel base superalloys the gamma prime phase may occur in quantities as great as 60 volume percent. The second strengthening mechanism is the solid solution strengthening which is produced by the presence of the refractory metals such as tungsten and molybdenum in the nickel solid solution matrix. For a constant volume fraction of gamma prime, considerable variations in the strengthening effect of this volume fraction of gamma prime may be obtained by varying the size and morphology of the gamma prime precipitate particles. The gamma prime phase is characterized by having a solvus temperature above which the phase dissolves into the matrix. In many cast alloys, however, the gamma prime solvus temperature is in fact above the incipient melting temperature so that it is not possible to effectively solutionize the gamma prime phase without incipient melting. Solutionizing of the gamma prime is the only way in which the morphology of the as cast gamma prime phase can be modified, hence for many modern commercial nickel base superalloys the gamma prime morphology is limited to the morphology which resulted from the original casting process. The other strengthening mechanism, solid solution strengthening, is most effective when the solid solution strengthening elements are uniformly distributed throughout the nickel solid solution matrix. Again this strengthening is reduced in effectiveness because of the nature of the casting and solidification process. Practical nickel base superalloys freeze over a wide temperature range. The freezing or solidification process involves the formation of high melting point dendrites followed by the subsequent freezing of the lower temperature melting interdendritic liquid. This solidification process leads to significant compositional inhomogeneities throughout the microstructure. It is theoretically possible to homogenize such a microstructure by heating at elevated temperatures to permit diffusion to occur, however, in practical nickel base superalloys the maximum homogenization temperature, which is limited by the incipient melting temperature, is too low to permit significant homogenization in practical time intervals.
SUMMARY OF THE INVENTION
This invention includes three interrelated aspects. The first aspect is the particular alloy employed. The alloy is a nickel base alloy containing from about 8 to about 12% chromium, from about 4.5 to about 5.5% aluminum, from about 1 to 2% titanium, from 3 to 5% tungsten, and from 10 to 14% tantalum. The cobalt content is controlled to fall within the range of 3-7%, and the balance is essentially nickel. The alloy employed in the present invention is free from intentional additions of carbon, boron and zirconium, although obviously these elements may be present as unintentional impurities. The alloy is characterized by having an incipient melting temperature in excess of about 2300° F. Thus, this alloy may be heat treated under conditions which permit solutionizing of the gamma prime phase without incipient melting. At the same time the high incipient melting temperature permits essentially complete homogenization of the alloy in commercially practicable times. The high incipient melting temperature of the alloy is a result of the absence of carbon, boron and zirconium. The low cobalt content inhibits the formation of deleterious TCP phases.
The second important aspect of the invention is the formation of the previously described alloy into single crystal articles.
The third aspect of the invention is the heat treatment sequence by which the gamma prime morphology may be modified and refined at the same time that significant homogenization of the as cast microstructure is performed. The resultant single crystal article will have a microstructure whose typical gamma prime particle size is about one third of the gamma prime particle size found in the as cast material. At the same time the heat treated single crystal microstructure will be essentially free from compositional inhomogeneities and this uniform microstructure combined with the increased gamma prime solvus temperature will permit the article of the present invention to exhibit temperature capabilities, for equal mechanical properties, which are at least 30° F. greater than the temperature capabilities of comparable prior art single crystal articles which are formed from conventional alloys containing carbon, boron and zirconium and conventional levels of cobalt. The alloys have advantages over conventional alloys even if not heat treated, but the heat treatment is the preferred embodiment.
The foregoing, and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of the preferred embodiment thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the description which follows, all percent figures are in weight percent unless otherwise specified.
This invention relates to an article made of a specific alloy by a critical series of process steps. Although other articles may be produced according to this invention, this invention has particular utility in the fabrication of airfoils (blades and vanes) for use in gas turbine engines. In particular, the high strength of articles made according to this invention make them especially suited for use as blades in gas turbine engines.
A primary feature in the alloys employed in the present invention is the substantial elimination of the grain boundary strengthening agents, carbon, boron and zirconium and the reduction in cobalt content relative to conventional superalloys. The alloys of the invention are intended for use as gas turbine components in a single crystal form. No intentional additions of the elements, carbon, boron and zirconium are made, however, some will invariably be present as an impurity.
In order to ensure that TCP phases will not form in the alloy over a wide range of compositions and operating conditions, the level of cobalt is controlled to fall within the range of 3 to 7%.
Likewise, with regard to the grain boundary strengthening agents carbon, boron and zirconium, no intentional additions are made. If the maximum benefit is to be obtained from this invention, no single element of the group carbon, boron and zirconium should be present in an amount greater than 50 ppm and it is preferred that the total of such impurities be less than 100 ppm. Most preferably carbon is present in an amount less than 30 ppm and the remaining elements are each present in quantities less than 20 ppm. In any event, the carbon level must be restricted to be below that amount of carbon which will form MC type carbides. It must be emphasized that no intentional addition of these elements is contemplated and that their presence in the alloy or single crystal article of the invention is unintentional and undesirable.
Alloys which can be produced using the concept of the present invention will contain:
(1) from 8 to 12% chromium,
(2) from 4.5 to 5.5% aluminum, and from 1-2% titanium,
(3) from 3-5% tungsten and from 10-14% tantalum,
(4) from 3-7% cobalt,
(5) balance essentially nickel.
Within the preceding ranges, certain relationships are preferred. The sum of tungsten and tantalum levels is preferably at least 15.5% to insure adequate solid solution strengthening and improved elevated temperature creep strength. A tantalum level of at least 11% is preferred for oxidation resistance. The elements aluminum, titanium and tantalum participate in the formation of the gamma prime phase (Ni 3 Al, Ti, Ta) and for maximum strengthening by the gamma prime phase the total content of aluminum plus titanium plus tantalum is preferably at least 17.5%. Aluminum and titanium are the principal elements which form the gamma prime phase and the ratio of aluminum to titanium must be controlled to be greater than 2.5 and preferably greater than 3.0 to insure adequate oxidation resistance. At least 9% chromium should be present if the article is to be used in environments where sulfidation is a problem. The minor addition of cobalt also aids in improving sulfidation resistance.
Alloys made according to the preceding limitations will comprise a nickel chromium solid solution containing at least 30% by volume of the ordered phase of the composition Ni 3 M where M is aluminum, titanium, tantalum, and tungsten to a lesser degree.
The alloys within the ranges set forth above are thermally stable and deleterious microstructural instabilities such as the cobalt containing TCP phases will not form, even after extended exposure at elevated temperature as for example 500 hours at either 1600°, 1800° or 2000° F. Further, the alloys have good fatigue properties since the formation of deleterious carbide particles is prevented. The refractory metals which would normally combine with carbon or precipitate in TCP phase formation remain in solid solution and result in an alloy having exceptional mechanical properties.
An important benefit which arises from the elimination of boron, carbon and zirconium is an increase in the incipient melting temperature. Typically the incipient melting temperature of the present alloys, that temperature at which the alloy first begins localized melting, will be increased by at least 50° F. over the incipient melting temperature of a similar (prior art) alloy which contains normal amounts of carbon, boron and zirconium. The incipient melting temperature of the alloy of this invention will typically exceed 2300° F. while conventional high strength, high volume fraction gamma-gamma prime alloys typically have incipient melting temperatures below 2300° F. This increased temperature permits solutionizing heat treatments to be performed at temperatures where complete solutionizing of the precipitated gamma prime is possible while simultaneously permitting a significant amount of homogenization within reasonable times.
The alloys of the present invention will not form the carbides which have been found necessary for grain boundary strengthening in polycrystalline nickel base superalloys. For this reason the alloys of the present invention must be used as single crystal articles. The formation of the alloy into single crystal form is a critical aspect of the present invention, but the method of single crystal formation is unimportant. Typical articles and solidification techniques are described in U.S. Pat. No. 3,494,709 to Piearcey, which is assigned to the assignee of the present application, and the contents of this patent are incorporated herein by reference.
The final aspect of the invention involves the specific heat treatment applied to the single crystal article. The as cast single crystal article will contain the gamma prime phase in dispersed form with a typical particle size on the order of 1.5 microns. The gamma prime solvus of the alloy will typically fall in the range of 2350°-2400° F. and the incipient melting temperature will be in excess of about 2350° F. Thus, heat treatment in the range of 2350°-2400° F. (but below the incipient melting temperature) will place the precipitated gamma prime phase into solution without deleterious localized melting. Times on the order of 1/2 to 8 hours will normally be satisfactory although longer times may be employed. Such heat treatment temperatures are about 100° F. higher than those which can be employed with polycrystalline articles of conventional superalloys. This elevated temperature permits a substantial amount of homogenization to occur during the solutionizing steps.
Following the solutionizing treatment, an aging treatment at 1600°-2000° F. may be utilized to reprecipitate the gamma prime in refined form. Typical gamma prime particle sizes after reprecipitation will be less than about 0.5 micron.
The preceding discussion of the preferred embodiment will be clarified through reference to the following illustrative examples:
EXAMPLE 1
Alloys having compositions set forth in Table I were prepared.
TABLE I__________________________________________________________________________ Cr W Ta Al Ti Co Hf C B Cb Mo Zr__________________________________________________________________________Alloy 444 (a) 9 12 -- 5 2.0 -- -- -- -- -- -- --Alloy 454 (a) 10 4 12 5 1.5 5 -- -- -- -- -- --Alloy PWA 1409 (a) 9 12.5 -- 5 2.0 10 -- .15 .015 1.0 -- .05Alloy PWA 1422 (b) 9 12.0 -- 5 2.0 10 2.0 .11 .015 1.0 -- .10Alloy PWA 1455 (c) 8 -- 4.3 6 1.0 10 1.15 .11 .015 -- 6 .07Alloy PWA 1481 (a) 10 6 8 6 1.0 -- -- -- -- -- -- --Alloy SM 200 (b,c,d) 9 12.5 -- 5 2.0 10 -- .15 .015 1.0 -- .05Alloy SM 200 (a,d) 8.4 12.35 -- 5.2 2.2 9.65 -- .10 <.001 1.1 -- < .001(No B, No Zr) (Balance Nickel)__________________________________________________________________________ (a) Single crystal form (b) Columnar grains (c) Equiaxed grains (d) Shown in U.S. Pat. No. 3,494,709
Alloy 444 is disclosed in U.S. Ser. No. 742,967, the parent case of the present application. Alloy 454 is the alloy of the present invention. Both of these alloys were solidified in single crystal form. Alloy PWA 1422 is a commercial alloy used as a blade material in gas turbine engines and noted for its high temperature mechanical properties. Alloy PWA 1422 was produced in a directionally solidified form having elongated columnar grains. Alloy 1455 is a commercial alloy which has been used as a gas turbine blade material. It is noted for its high temperature oxidation resistance. This alloy was produced by conventional casting methods with equiaxed nonoriented grains. Alloy PWA 1481 is a previously developed single crystal alloy developed to have good oxidation/corrosion behavior in combination with reasonable mechanical properties.
It can be seen that SM 200, SM 200 (No B, Zr), PWA 1409 and PWA 1422 have similar compositions. SM 200 represents the original alloy composition and is used in either equiaxed or directionally solidified columnar grained form. SM 200 (No B, Zr) represents a modification in which B and Zr are deleted. These elements primarily affect grain boundaries and this modified composition is intended for single crystal applications where grain boundary strength is not a consideration. Alloy PWA 1422 is alloy SM 200 with additions of Hf for improved transverse ductility. PWA 1422 is used in directionally solidified columnar grained form. Alloy PWA 1409 is another composition which is used in single crystal form. Except for its intended form, it is quite similar to SM 200.
The experimental alloys (alloys 444 and 454) were heat treated according to the invention, the treatment used was a 4 hour solution heat treatment at 2350° F. with subsequent aging treatments at 1975° F. for 4 hours and 1600° F. for 32 hours. Alloys PWA 1409 and 1422 were treated at 2200° F. for 2 hours followed by aging treatments at 1975° F. for 4 hours and 1600° F. for 32 hours and the alloy PWA 1455 was tested as cast. The prior art alloys were heat treated according to the usual commercial practice. The SM 200 samples were heat treated at 2250° F. for 1 hour and then at 1600° F. for 32 hours.
EXAMPLE 2
Some of the alloy samples produced in Example 1 were tested to evaluate their creep rupture properties. The test conditions and results are set forth below in Table II.
TABLE II______________________________________ TIME % TEST TO 1% RUPTURE ELON-ALLOY CONDITIONS CREEP LIFE GATION______________________________________SM 200 1400° F./95 ksi -- 728.4 12.2Alloy 454 1400° F./95 ksi -- 1200* 9.0*Alloy 454 1400° F./110 ksi -- 475 8.8Alloy 444 1700° F./50 ksi 28.5 82.6 --Alloy 454 1700° F./50 ksi 46.2 165.6 --PWA 1422 1700° F./50 ksi 17 76 --Alloy 444 1800° F./29 ksi 110 310 --Alloy 454 1800° F./29 ksi 143.9 350 --PWA 1422 1800° F./29 ksi 60 160 --Alloy 454 1800° F./30 ksi -- 240* 12.0*SM 200 1800° F./30 ksi -- 124.5 24.9SM 200(No B, Zr) 1800° F./30 ksi -- 191.5 12.8______________________________________ *Extrapolated value
Referring to Table II, it is apparent that under the test conditions employed, the invention alloy (454) was superior to the other alloys tested including SM 200, SM 200 (No B, Zr), 444 and PWA 1422. The proportionate degree of superiority of the invention alloy, in time to 1% creep, to alloy 444 can be seen to diminish somewhat with increasing temperature. However, in creep, the superiority of the invention alloy to the commercial alloy, 1422, can be seen to increase significantly with increasing test temperature.
In terms of rupture life, the superiority of the invention alloy to the 1422 alloy is seen to increase with increasing temperature. The invention alloy displays properties superior to those of the other alloys under all conditions tested. Since the trend in gas turbine engines is toward increased efficiency through higher temperature, the improved elevated temperature properties of the present invention are significant.
EXAMPLE 3
Samples of some of the materials described in Example 1 were tested for resistance to sulfidation and oxidation at elevated temperatures. The sulfidation test involved the application of Na 2 SO 4 at the rate of 1 mg/cm 2 every twenty hours. The failure criteria was a weight loss of 250 mg/cm 2 or more. The oxidation tests were performed both on the unprotected alloys at 2100° F. under cyclic conditions and on the alloys protected with a NiCoCrAlY type of coating under cyclic conditions at 2150° F. NiCoCrAlY is a commercial coating material having a nominal composition of 18% Cr, 23% Co, 12.5% Al, 0.3% Y, balance nickel. The tests on coated samples were normalized to minimize the effect of different coating thicknesses. This coating is described in U.S. Pat. No. 3,928,026 which is incorporated herein by reference. The tests of coated samples are significant since these alloys are always used in a coated condition and since coating substrate interactions occur in-service. The test results are shown below in Table III.
TABLE III______________________________________Sulfidation and Oxidation Data 2100° F. Un- 2150° F. Cy- 1650° F. coated Oxida- clic Burner Furnace tion Resis- Rig NiCoCrAly Sulfidation tance (mils of Coated (hours to (Hours to attack in failure perAlloy Failure) 200 hours) mil of coating)______________________________________454 313 7 160444 178 N.A. 90.0PWA 1455 42 8 102.5PWA 1422 178 24* 50______________________________________ *Measured after 143 hours.
The sulfidation resistance of the invention alloy is clearly superior to that of the other alloys tested. Likewise, in cyclic oxidation evaluation of uncoated samples, the invention alloy outperforms even alloy 1455, an alloy noted for inherent oxidation resistance. Even when a protective coating is employed, the invention alloy displays superior resistance to elevated temperature cyclic oxidation.
EXAMPLE 4
Tensile tests were conducted on alloys 454, SM 200, and PWA 1481 at room temperature and 1100° F. The results are shown below.
TABLE IV______________________________________ .2% YS UTSAlloy Temperature (Ksi) (Ksi) % Elong.______________________________________SM 200 10 70° F. 149.3 150.6 2.3SM 200 (No B, Zr) 70° F. 152.6 154.7 4.0454 70° F. 168.5 197.4 8.71409 1100° F. 140 165 --1481 1100° F. 157 203 --454 1100° F. 172 206 --______________________________________
Again the marked superiority of the invention alloy, 454 is evident. The yield strength improvements are believed to be related in general to the Ta level. Alloys SM 200/1409, 1481, and 454 contain 0, 8, and 12% Ta respectively and the high Ta content of the invention alloy is believed largely responsible for its superior tensile properties.
Although the invention has been shown and described with respect to a preferred embodiment thereof, it should be understood by those skilled in the art that various changes and omissions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention.
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Nickel base superalloy single crystal articles formed of a particular compositon and heat treated are described as is the process employed. The resultant articles are substantially free from the grain boundary strengtheners such as carbon, boron, and zirconium and contain only a limited amount of cobalt. As a result of the alloy composition, the alloys have a high incipient melting temperature. The heat treatment process homogenizes the micro-structure, and refines the gamma prime morphology.
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BACKGROUND OF THE INVENTION
This invention is concerned with movable bulkheads for swimming pools. A typical prior art arrangement is illustrated in my earlier U.S. Pat. No. 3,962,735 issued June 15, 1976. Essentially, the bulkheads comprise a frame supporting a platform or walkway and having at each side of the frame a barrier wall. Conventionally, the frame has been a box frame with the barrier wall means constituting frame support elements, or a double truss arrangement has been used in which the trusses are disposed at opposite longitudinal edges of the platform or a composite truss has been used with the trusses again disposed at the longitudinal edges of the platform. It has been conventional to assemble the bulkhead prior to delivery to the pool site and, upon delivery to the pool, to install the assembled structure. This is in many instances both cumbersome and difficult since the structures are relatively large.
Additionally, the bulkheads usually have a depth only slightly less than the minimum depth of the pool and with existing barriers this means that while the movement of the bulkhead within the deeper portions of the pool is relatively easy, great effort is required to move the bulkhead to the shallow end of the pool since the space beneath the bulkhead for the water to move from one side to the other of that structure becomes very limited.
BRIEF SUMMARY OF THE INVENTION
The present invention seeks to provide a bulkhead of simple and lightweight structure which facilitates handling of the bulkhead and also permits the ready assembly of the bulkhead on site, in this way to avoid the difficulties discussed above. Additionally, according to the present invention, the bulkhead is provided with a flow through characteristic which facilitates the moving of the bulkhead through the pool. This feature additionally assists in the suppression of waves caused by a swimmer nearing the bulkhead and also to this end there is provided a longitudinally extending slot in the bulkhead positioned just above the surface of the water of the pool. This slot, or rather the marginal edges defining the slot, provide a hand grip for a swimmer.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
The present invention is illustrated, schematically, in the accompanying drawings in which:
FIG. 1 is a front elevation of a bulkhead frame according to the present invention;
FIG. 2 is a section on the line D--D of FIG. 1; and
FIG. 3 is a composite section of the bulkhead of which the frame is illustrated in FIG. 1, that part of FIG. 3 to the left of the center line being a section on the line E--E and that part of FIG. 3 to the right of the center line being a section on the line F--F of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The main truss of the bulkhead of this invention is illustrated in FIG. 1 and comprises a lower chord 10 comprising, as can be seen in FIGS. 2 and 3 a pair of structural stainless steel angles 12 and 14. An upper chord indicated at 16 is made up, again as can be seen in FIGS. 2 and 3, of a pair of structural angles 18 and 20. Between the adjacent flanges of angles 12 and 14 at spaced intervals therealong are gusset plates 22, 24, 26, etc. and similar gusset plates 28, 30, etc. are secured to the top chord 16. Diagonal truss members 32, 34, 36, 38, etc. extend between the gusset plates to constitute, with the upper and lower chords, the main truss.
At each end of the main truss a pair of outrigger angles 35 and 37, visible in FIG. 2, are provided. The lower portions of those outriggers being secured to respective ones of the angles making up the lower chord and the upper ends of the ties 35 and 37 being secured to an angle 39 which is secured, by means of a connection element 40, to the upper chord 16. In this way, the angles 35, 37 define a generally V-shaped structure. Secured in appropriate cross members of the frame and at each end of the main truss are a pair of spaced apart axles 42 which carry grooved wheels 44 which cooperate with an appropriate configuration in the side gutter of the pool, there being four such wheels, two at each end of the truss those wheels supporting the truss, and when completed, the whole bulkhead, within the pool. It will, of course, be appreciated that when the bulkhead is assembled appropriate floatation devices can be provided within the body of the bulkhead to relieve the load on the individual wheels.
For ease in transportation and assembly, the upper and lower chords are made in several length, the individual lengths being connected to form the upper and lower chords by splice plates generally indicated at 50.
At intervals spaced along the length of the main truss, there are provided pairs of outrigger angles 52, seen particularly in FIG. 3, the lower ends of the angles 52 being secured to the bottom chord and the upper ends of those angles being connected to a cross brace 54, which in turn is connected to the top chord by connecting element 56. The pairs of angles 52 together define V-shaped structures or strut elements, which most desirably, are spaced apart by the width, in a pool utilized for racing, of a lane which is generally about seven feet.
At the upper edges of the elements 52 and extending longitudinally of the bulkhead, are pairs of angle supports 58.
Secured to the upper edges of these angles 58 and to the horizontal flanges of the angle irons making up the top girder or upper chord 16, is a perforated stainless steel sheet 60 atop which a non-slip surface 62 is disposed, the surface 62 providing the walkway of the bulkhead. The sheet 60 is welded to the angles, and thus provides horizontal resistance to bulkhead deflection from tightened racing lane dividers extending from brackets 90, and from swimmers' turns.
Secured to each of the elements 52 and projecting outwardly therefrom are bracket elements 64, each of which supports an upper longitudinally extending angle 66, the purpose of which is described hereinafter.
Towards the lowermost parts of the elements 52, cross bracing elements 68 are secured, those elements projecting to opposite sides of the elements 52 and supported at each end of each element 68 are lower longitudinally extending angles 70.
In between upper and lower longitudinally extending angles 66 and 70 are intermediate longitudinally extending angles 67 supported upon the central parts of elements 52 via brackets 65. These angles 67 and the cross bracing provided by brackets 67 add further horizontal bracing against deflection, particularly caused by tired swimmers whose leg thrusts tend to become lower and lower in the water after extensive swimming, and also provides support pieces upon which may be attached floatation elements.
At each side of the bulkhead, and secured to the angles 66, 67, and 70 is a perforated stainless steel sheet 72 which extends from approximately 1/2" above water level to a level close to the lower girder. The gap 74 between the platform and the upper edges of the sheet 72 serves a purpose as discussed supra in suppressing wave action by permitting a wave caused by a swimmer nearing the bulkhead to pass over and through the immediately adjacent surface of the bulkhead to be dissipated.
The upper edges of the steel sheet 72 are provided with a finishing element 76 which serves as a hand hold for a swimmer.
The outer surfaces of the sheet steel plates are clad with a non-slip, rubber based plastic coating in tile form, indicated generally at 78. The covering is U-shaped as shown with limbs extending toward the edges of the platform, and extends as indicated at 80 beneath the bulkhead and substantially precludes the possibility of a swimmer becoming trapped between the bottom of the bulkhead and the pool bottom and as it is resilient, if accidentally hit by a swimmer, the swimmer will be unharmed.
The surfacing tiles of the bulkhead barrier means are perforated and this, together with the perforations in the steel upon which those tiles are supported, serves to facilitate the moving of the bulkhead through a pool by allowing the water to pass freely from one side to the other of the bulkhead and also serves in the suppression of waves.
It will be noted that by the adoption of a single central truss, i.e. a truss central to the walkway, the ability of the truss to support a load to each side of its plane is utilized and this, of course, allows the simple lightweight frame to support the walkway. It will be appreciated that it is additionally possible to use two, or even more, vertically disposed trusses and in each instance to have the walkway extend beyond the planes of the trusses on both sides and this arrangement provides the substantial advantages over the conventional systems in terms of obtaining a lightweight yet strong structure.
It will be recognized by those skilled in the art that the frameword illustrated herein is one which can be assembled readily on site conveniently by bolting the various components together and then making adjustments to accommodate any sag in the framework or distortion and thereafter welding the components together to render the structure permanent and solid. By the adoption of this technique, since the framework as it is installed in an empty pool is supporting the maximum weight to which the structure is very likely to be subject, it is possible to achieve a rigid and level structure not always possible with a preassembled structure. It will be recognized that when the pool is filled, the weight of the structure can be controlled as desired or required by the floatation devices embodied within the bulkhead.
It will be recognized that various modifications of the equipment shown herein to accommodate different pool gutter structures, etc. are quite possible and well within the scope of the claims appended hereto.
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A bulkhead for a swimming pool has a simple, lightweight frame, improved movability within the pool and means for suppressing the ill effects of waves produced by a swimmer nearing the bulkhead.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/833,995 entitled “Method and Apparatus for Testing a Tubular Annular Seal” filed on Jun. 12, 2013, the entire disclosure of which is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] Embodiments of the present invention are generally related to a method and apparatus for hydrocarbon wellbores and in particular, to a method and apparatus for testing the annular seal of a tubular string of a wellbore.
BACKGROUND OF THE INVENTION
[0003] Wellbores drilled for hydrocarbon extraction involve a series of assembly and testing steps before hydrocarbon production may begin. One step requires testing to ensure the integrity of cement used to seal the wellbore casing to the surrounding rock formation. This cement seal prevents communication between producing zones, acquifiers, and any contamination related thereto. Integrity testing traditionally involves water shut-off tests, formation integrity tests, and cement bond logs. Traditional integrity testing means and methods, such as cement bond logs, while generally effective are of significant cost and complexity.
[0004] Various efforts have been made to significantly improve wellbore cementing operations. For example, U.S. Pat. No. 6,679,336 to Musselwhite et al. (“Musselwhite”) issued Jan. 20, 2004 discloses a float shoe/collar apparatus and method for multi-purpose use in running a tubular string such as a casing string or liner into a wellbore and for optimizing cementing operations. In one embodiment, the apparatus permits auto filling of the tubular string as the string is lowered into the wellbore. Circulation can be effected through down jets for washing the wellbore as necessary. After the tubular string is positioned, the down jets can be blocked off and up jets opened to thereby direct cement upwardly to optimize cement placement. Check valves can also be activated to prevent flow from the wellbore into the tubular string. The apparatus comprises an inner member and tubular member. The inner member is movable upon release of shear pins to cause longitudinal movement relative to the outer member. The movement of the inner member may close a plurality of downward jets and may also open a plurality of upward jets. The apparatus may also be equipped with a set of check valves which can be held open on run in, and subsequently activated to thereby automatically close upon cementing to prevent “u-tubing” of fluid from the annulus back into the casing or other tubing string. However, Musselwhite does not disclose a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. Musselwhite is incorporated herein by reference in its entirety.
[0005] European Patent No. EP0489816 to Mueller et al. (“Mueller”) issued Jun. 17, 1992 and discloses a ported float shoe and a landing collar attached at a first end of a portion of a casing string and a sliding air trapping insert attached at the other end. The air trapping insert includes a fluid flow passageway blocked by a plug attached by shear pins to the insert or having a conduit providing a fluid passageway to the first end. The air trapping insert and float shoe form an air cavity within the string portion. The air cavity provides buoyant forces during running, cementing or other casing operations within a borehole, reducing running drag and the related chance of a differentially stuck casing. However, Mueller does not disclose a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. Mueller is incorporated herein by reference in its entirety.
[0006] U.S. Pat. No. 2,120,694 to Crowell (“Crowell”) issued Jun. 14, 1938 discloses a means for cementing oil wells, principally to shut out water, as well as to support and protect the casing. Crowell discloses a specialized valve to perform three functions; a float valve to float the casing in, as part of a cementing plug to actuate valve means to open lateral ports through the wall of the casing, and to close the bore through the casing below said lateral port and thus deflect the cementing mixture there-through. Crowell does not disclose a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. Crowell is incorporated herein by reference in its entirety.
[0007] U.S. Pat. No. 2,735,498 to Muse (“Muse”) issued Feb. 21, 1956 discloses a subsurface well bore apparatus adapted to form part of a conduit string, such as a casing, liner or drill pipe string, as it is lowered through fluid in the well bore. Muse does not disclose a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. Muse is incorporated herein by reference in its entirety.
[0008] U.S. Pat. No. 3,768,562 to Baker (“Baker”) issued Oct. 30, 1973 discloses a full opening cementing tool suitable for cementing an oil well Baker utilizes a cylindrical housing, a sliding valve sleeve within the housing, and an opening positioner and a closing positioned located on a pipe string within the casing for actuating the sliding valve sleeve. Other tools such as isolation packers and circulating valves may be used in conjunction with one or more of the cementing tools. Baker does not disclose a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. Baker is incorporated herein by reference in its entirety.
[0009] U.S. Pat. No. 4,132,111 to Hasha (“Hasha”) issued Jan. 2, 1979 discloses a body having a longitudinal opening provided with longitudinally spaced, annular seal means. The body is provided with passage means for conducting fluid to move the seal means radially of the body opening to seal against tubular members in the body opening. The tubular members are connected together by suitable means such as a coupling, weld, or other arrangement prior to positioning the connection between the seal means. After the seal means has sealed off the connection there between, the body includes additional passage means for conducting fluid pressure to increase the fluid pressure externally of the connection to a pressure significantly greater than the internal pressure to externally test the connection by instrumentally or visually detecting any resultant inflow of the pressurized external fluid. Where the method is employed for leak testing a thread-connected, multiple seal pipe joint having at least one internal and at least one external sealing arrangement, the connection between the tubular members may be only partially made up to a predetermined condition at which a primary or initial internal seal is established in the connection without engaging the external seal. After the joint has been externally tested in this condition, the test seals may be withdrawn from the tubular member and the connection completed to full make-up torque, and the joint again externally sealed and fluid pressure applied to externally test the connection. Hasha, however, does not disclose a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. Hasha is incorporated herein by reference in its entirety.
[0010] U.S. Pat. No. 4,694,903 to Ringgenburg (“Ringgenberg”) issued Sep. 22, 1997 discloses a tubing tester valve of the present invention comprises a tubular housing assembly having a downwardly closing, spring biased flapper valve. A tubular mandrel assembly is disposed within the housing assembly below the flapper valve, and is secured to the housing assembly with shear pins. The tubing tester valve may be permanently opened through the application of annulus pressure from the rig floor to the annulus surrounding the pipe string, which pressure moves the mandrel assembly upward to rotate the flapper valve to an open position. In order to assure that the mandrel assembly does not retract downwardly, thus permitting the flapper valve to reclose, a spring biased locking means is provided to hold the mandrel assembly in its “up” position. However, Ringgenberg does not disclose a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. Ringgenberg is incorporated herein by reference in its entirety.
[0011] U.S. Pat. No. 6,401,824 to Musselwhite, et al. (“Musselwhite”) issued Jun. 11, 2002 discloses an improved float shoe/collar apparatus is provided for use during casing run in or floated in. The apparatus has an inner tubular member and outer tubular member, movable upon release of shear pins to cause longitudinal movement relative to each other. The movement of the inner tubular member closes a plurality of downward jets and opens a plurality of upward jets. The apparatus also is equipped with a set of check valves, held open on run in, and activated to close upon cementing to prevent “u-tubing” of fluid back into the casing. Musselwhite does not disclose a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. Musselwhite is incorporated herein by reference in its entirety.
[0012] What is needed is an apparatus and method for testing the sealing integrity of wellbores, and particularly an apparatus and method to efficiently and effectively test the annular seal of a tubular string positioned within a wellbore. In one embodiment of the invention, an apparatus and method are disclosed which allow direct testing of the hydraulic annular seal of casing without the use of a cement bond log (“CBL”). In one embodiment, surface casing could be tested for an annular seal in a fraction of the time and expense of the use of cement bond logs. It has been estimated in a report for the Western Energy Alliance that proposed cement bond log regulations by the BLM would cost over $140,000 per well in direct costs and lost rig time. In contrast, the use of one embodiment of the present invention could test the seal of the annulus of a casing for a fraction of this cost.
SUMMARY OF THE INVENTION
[0013] It is one aspect of the present invention to provide an apparatus and method for testing a wellbore, and more specifically an apparatus and method to efficiently and effectively test the annular seal of a tubular string positioned within a wellbore. More specifically, the cement seal between a casing string and a wellbore is tested to assure there is no contamination of groundwater or between different geologic formations. An additional aspect of the present invention is to provide a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. In one particular embodiment, the frangible body initially forms an encapsulated bore that aligns with the passageway.
[0014] In one embodiment of the invention, a downhole casing assembly adapted for positioning and testing the cement integrity within a wellbore is disclosed, the assembly comprising: a testing assembly body having an interior surface defining a cavity and at least one aperture extending through the body to an exterior surface; a frangible body positioned within the testing assembly body and comprising material adapted to seal the at least one aperture; and wherein a passageway is created between the cavity and the exterior surface of the testing assembly when the frangible body is substantially removed.
[0015] In another embodiment of the invention, a method for testing a sealing integrity of a targeted tubular annular seal of a wellbore is disclosed, the method comprising: providing a casing and testing assembly, the assembly comprising a testing assembly body having an interior surface defining a cavity and at least one aperture extending through the body to an exterior surface, and a frangible body positioned within the testing assembly body and comprising material adapted to seal the at least one aperture; positioning the assembly adjacent the targeted tubular annular seal of the wellbore, the assembly positioned below a landed cement plug, the wellbore comprising a casing interior and a casing annulus; drilling through the landed cement plug and through the interior of the assembly to create a passageway to the casing annulus via the at least one aperture of the assembly; wherein pressure and fluid communication between the casing interior and the casing annulus is enabled; and testing the sealing integrity of the targeted tubular annular seal to assure a cement seal is formed in the tubular annulus.
[0016] The term “wellbore” and variations thereof, as used herein, refers to a hole drilled into the earth's surface to explore or extract natural materials to include water, gas and oil.
[0017] The term “casing” and variations thereof, as used herein, refers to large diameter pipe that is assembled and inserted into a wellbore and typically secured in place to the surrounding formation with cement.
[0018] The term “float value”, “casing float valve”, and “float collar” and variations thereof, as used herein, refers to valves that allows flow in one direction (typically down the tubular) but not the other, to include autofill floats and ball floats.
[0019] The term “tubular string” and variations thereof, as used herein, refers to an assembled length of pipe, to include jointed pipe and integral tubular members such as coiled tubing, and which generally is positioned within the casing.
[0020] The term “frangible material” and variations thereof, as used herein, refers to any material tending to break into fragments when a force is applied thereto, to include cement, plastic, composite or other similar drillable material.
[0021] This Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present disclosure. The present disclosure is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description of the Invention, and no limitation as to the scope of the present disclosure is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present disclosure will become more readily apparent from the Detailed Description, particularly when taken together with the drawings.
[0022] The above-described benefits, embodiments, and/or characterizations are not necessarily complete or exhaustive, and in particular, as to the patentable subject matter disclosed herein. Other benefits, embodiments, and/or characterizations of the present disclosure are possible utilizing, alone or in combination, as set forth above and/or described in the accompanying figures and/or in the description herein below. However, the Detailed Description of the Invention, the drawing figures, and the exemplary claim set forth herein, taken in conjunction with this Summary of the Invention, define the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above, and the detailed description of the drawings given below, serve to explain the principals of this invention.
[0024] FIG. 1A depicts a front elevation sectional view of a testing assembly according to one embodiment of the present invention;
[0025] FIG. 1B depicts a front elevation sectional view of the testing assembly of FIG. 1A after removal of the testing assembly frangible body portion according to one embodiment of the present invention;
[0026] FIG. 2 is a detailed front elevation sectional view of the testing assembly of FIG. 1A with additional wellbore components according to one embodiment of the present invention;
[0027] FIG. 3A depicts a front elevation sectional view of a wellbore with conventional float collar according to the prior art;
[0028] FIG. 3B depicts a front elevation sectional view of a wellbore with installed testing assembly according to one embodiment of the present invention;
[0029] FIG. 3C depicts a front elevation sectional view of a wellbore with installed testing assembly of FIG. 3B after removal of the testing assembly frangible body portion according to one embodiment of the present invention; and
[0030] FIG. 4 depicts a front elevation sectional view of a pictorial representation of a wellbore prepared for integrity testing.
[0031] It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION
[0032] FIGS. 1A-B and 2 and 3 B-C depict cross-sectional views of a Testing Assembly 2 according to one embodiment of the present invention. FIG. 1A depicts the Testing Assembly 2 as initially installed into a wellbore at a location of interest for annular seal testing. FIG. 1B depicts the Testing Assembly 2 of FIG. 1A after removal of the Testing Assembly Frangible Body 12 portion of the Testing Assembly 2 . FIG. 2 is a detailed front elevation sectional view of the testing assembly of FIG. 1A .
[0033] Referring now to FIG. 1A , the Testing Assembly 2 forms Testing Assembly Cavity 4 . Testing Assembly 2 comprises Testing Assembly Tool Body 6 and Testing Assembly Frangible Body 12 . Testing Assembly Tool Body 6 comprises Testing Assembly Tool Body Interior Surface 8 and Testing Assembly Tool Body Aperture 10 . Testing Assembly Frangible Body 12 forms Testing Assembly Frangible Body Inner Cavity 22 and comprises Testing Assembly Frangible Body Proximal End 14 , Testing Assembly Frangible Body Distal End 16 , Testing Assembly Frangible Body Exterior Surface 18 , Testing Assembly Frangible Body Interior Surface 20 and Testing Assembly Frangible Body Outer Cavity 24 .
[0034] Testing Assembly Frangible Body Exterior Surface 18 substantially aligns with and is in substantial contact with Testing Assembly Tool Body Interior Surface 8 . Testing Assembly Frangible Body 12 is configured to span across Testing Assembly Tool Body 10 to form a seal. Testing Assembly Frangible Body Outer Cavity 24 is substantially aligned with Testing Assembly Tool Body Aperture 10 .
[0035] Generally, the Testing Assembly 2 functions to test the annular seal of a tubular string (e.g. casing or tubing) placed in a wellbore by means of the Testing Assembly Frangible Body Outer Cavity 24 , i.e. by allowing communication between the interior and exterior of the casing. The Testing Assembly Frangible Body Outer Cavity 24 is positioned to align axially with the Testing Assembly Tool Body Aperture 10 .
[0036] The Testing Assembly Frangible Body Outer Cavity 24 is closed to the inside of the tubular string (area radially exterior or outside the Testing Assembly Tool Body 6 ) and is configured or constructed so that when the Testing Assembly Frangible Body 12 is destructively removed by drilling or other similar means (resulting in the configuration depicted in FIG. 1B ), a passageway is open to the annulus of the casing on the tubular string. That is, a passageway between Testing Assembly Cavity 4 through Testing Assembly Tool Body 6 via Testing Assembly Tool Body Aperture 10 is created. The passageway allows testing of the annular seal of a casing string placed in a wellbore. For example, the testing may comprise assessing the degree of hydraulic seal of the annulus by either positive or negative pressure testing. The removal of the Testing Assembly Frangible Body 12 may be by any means known to one of ordinary skill in the art, to include drilling and milling. The Testing Assembly Tool Body Aperture 10 may comprise a pre-drilled hole or other aperture known to those skilled in the art. The frangible material of the Testing Assembly Frangible Body 12 may be any material known to those skilled in the art, to comprise cement, plastic, composite or other similar drillable material.
[0037] In another embodiment, the Testing Assembly Frangible Body 12 does not comprise a Testing Assembly Frangible Body Outer Cavity 24 . That is, the Testing Assembly Frangible Body 12 forms a substantially continuous interconnection with the Testing Assembly Tool Body Interior Surface 8 , to include a portion spanning the Testing Assembly Tool Body Hole 10 . In this embodiment, upon the destructive removal of the Testing Assembly Frangible Body 12 , a passageway is still opened to the annulus of the tubular string as described above. However, this embodiment requires a drilling tool with sufficient tolerance to remove the Testing Assembly Frangible Body 12 from the inside of the Testing Assembly Tool Body 6 to create the aforementioned passageway. The passageway created is between Testing Assembly Cavity 4 through Testing Assembly Tool Body 6 via Testing Assembly Tool Body Aperture 10 , and enables a specified positive or negative pressure test of the annulus.
[0038] In one embodiment, a plurality of Testing Assemblies 2 are employed in a given wellbore 26 . Such a configuration allows integrity testing of casing to occur at multiple locations within a tubular string. A given Testing Assembly 2 , in isolation or as part of a plurality of Test Assemblies 2 , may be positioned at any targeted location of the wellbore 26 . In one embodiment, a plurality of Testing Assemblies 2 are employed at different predetermined depths in the wellbore, each with a potentially different configuration. For example, a first Testing Assembly 2 may comprise a Testing Assembly Frangible Body 12 of different composition than a second Testing Assembly Frangible Body 12 , thereby providing different properties during drill-through. Such a distinction provides feedback to the drilling operator and may be used as a positive indicator of engaging a particular Testing Assembly 2 .
[0039] The Testing Assembly Tool Body 6 may be interconnected to tubular members of a larger tubular string by any means known to those skilled in the art, to include a threaded connection and a welded connection. The tubular members of the tubular string may comprise, for example, jointed pipe and an integral tubular member such as coiled tubing.
[0040] In one embodiment, the Testing Assembly Tool Body 6 is adaptable such that it is configured to be incorporated into a pre-existing joint of pipe. For example, the Testing Assembly Tool Body 6 could be incorporated or interconnected to casing or at the connection or collar such as exists in so-called “API” connections or other commonly used tubular connections, in a manner similar to an insert float, as would be readily apparent to one of ordinary skill in the art.
[0041] In another embodiment, the Testing Assembly 2 is constructed by pouring of cement or other encapsulating material so as to harden into an adapted casing collar with the required opening through the tubular wall as necessary for the testing of the annular seal. The Testing Assembly 2 may be placed anywhere in an entire length of a tubular string.
[0042] In one preferred embodiment, the Testing Assembly 2 is positioned or disposed at or below the casing cementing collar, and above the casing shoe or bottom of the tubular string. In this embodiment, the casing or other tubular may be cemented into the wellbore during a process commonly called a primary cement job. At the end of the primary cementing process, the Testing Assembly 2 is surrounded with liquid cement in both the annulus of the tubular string, and throughout its interior. The interior of the casing is then drilled out, including the Testing Assembly Frangible Body 12 , to open the testing Assembly Tool Body Aperture 10 .
[0043] In another embodiment, the Testing Assembly 2 is positioned or disposed at or above the casing cementing collar, so as to allow testing of an annular seal at a relatively higher depth of interest. For example, a Testing Assembly 2 located adjacent a particular fresh water aquifer would allow additional testing of a cement seal between a surface casing and the aquifer.
[0044] In another embodiment, the Testing Assembly 2 is employed as part of a “leak-off” test to distinguish a pressure level required to trigger fluid entering the open formation versus that to trigger fluid compromising the production casing. Generally, a leak-off test is used to determine the pressure at which fluid will enter an open formation after drilling below the casing shoe. Fluid pressure is gradually increased until a pressure drop is observed, assumed to indicate that the fluid has entered, i.e. leaked into, the formation. This fluid pressure sets the maximum pressure that may be applied to the well during drilling operations. However, it is possible that the pressure drop may instead be caused by a leak in the production casing rather than fluid entering the formation. In order to distinguish or at least bound these two scenarios, the Testing Assembly 2 may be positioned in the production casing above the casing shoe and used, as previously described, to assess/test the integrity of the production casing cement, prior to conducting a conventional leak-off test.
[0045] In another embodiment, the Testing Assembly 2 may be directly incorporated into the construction of the casing cementing collar, which also may be designed to work as any type of float collar or Float Valve 48 as depicted in FIG. 2 . More specifically, the liquid cement is allowed to set and harden around the casing, by maintaining the casing in a static position. This is as customary during a primary casing or liner cement job. When enough time has elapsed, normally called the WOC or the Waiting on Cement time (which may be judged as sufficient by the time it takes for the cement to reach 500-1000 psi compressive strength), the bottom of the casing can be drilled out with normal drilling tools, and the well construction process continued.
[0046] FIG. 3A depicts a front elevation sectional view of a Wellbore 26 with Traditional Casing Float Collar 38 according to the prior art. FIG. 3B depicts a front elevation sectional view of a Wellbore 26 with installed Testing Assembly 2 of FIG. 1A according to one embodiment of the present invention. FIG. 3C depicts a front elevation sectional view of a Wellbore 26 with installed Testing Assembly 2 of FIG. 3B after removal of the Testing Assembly Frangible Body 12 according to one embodiment of the present invention.
[0047] FIG. 3A depicts a front elevation sectional view of a Wellbore 26 with Traditional Casing Float Collar 38 according to the prior art. In particular, FIG. 3A depicts a well construction primary cementing process during displacement of the cement through the end of the job, using a Traditional Casing Float Collar 38 . Generally, during the cementing process, cement is provided to Casing 28 comprising Casing Interior 30 , the cement flowing within interior as Casing Cement Flow 42 and engaging Cement Plug One 32 , Cement Plug Two 34 and Traditional Casing Float Collar 38 . Cement flows downward in the casing, and upward in the annulus, to create a seal between the Casing 28 and Wellbore 26 .
[0048] FIG. 3B depicts the substitution of the Testing Assembly 2 for the Traditional Casing Float Collar 38 . In FIG. 3B , the Wellbore 26 is depicted when both Cement Plug One 32 and Cement Plug Two 34 of FIG. 3A have landed therein forming Landed Cement Plug 46 .
[0049] In one embodiment of a method of use of the Testing Assembly 2 , the primary cement job is pumped in the customary manner as provided in FIG. 3A , with Testing Assembly 2 in the position of the Traditional Casing Float Collar 38 and performing the Traditional Casing Float Collar 38 normal functions of preventing the heavier cement column in the annulus when displacement stops from flowing back into the Casing 28 . The Testing Assembly 2 also functions as a stop for the cementing plugs 32 , 34 in the Casing 28 , providing an indication at the surface by an increase in pressure when the respective plugs land, indicating the position of the cement slurry.
[0050] It will be appreciated by one of skill in the art that the placement of the Testing Assembly 2 in this position may shield the Testing Assembly 2 from the higher differential pressure across the cement plugs customarily observed at the end of pumping the primary cement job, a process commonly called “bumping the plug”. Furthermore, the Testing Assembly 2 may be placed anywhere in the Wellbore 26 . In particular, the Testing Assembly 2 may be positioned at or below the position depicted in FIG. 3B , relative to the referenced placement of the Traditional Casing Float Collar 38 . In such a configuration, the pressure exerted on the inside and exterior of the Testing Assembly 2 will be nearly identical, and will be a function of the hydrostatic pressure of the cement.
[0051] In another embodiment, the Testing Assembly 2 is placed within 10 feet of the cement shoe, or at any user-selected position above the cement shoe as identified for optimal testing of the annular seal, and have a conventional cement collar above the Testing Assembly 2 in its normal position in the casing string. Such a configuration positions the Testing Assembly 2 in an optimal position or positions to test the set cement hydraulic seal around the Casing 28 , and prove that the formations above, such as fresh water aquifers, are protected from migration of fluid in the casing annulus.
[0052] In another embodiment, the Testing Assembly 2 may be employed with a conventional ported casing collar as known to those skilled in the art; however, this may cause the cement to be contaminated in the casing annulus near the ports if the cement is over displaced. In addition, the ports are always open to flow of cement during circulation of the cement, and may only prove that the cement has set up in the ports. Still, it is contemplated that the method of use of the Testing Assembly 2 could be practiced by the use of prior art ported casing collars.
[0053] After the cement has set up in the Wellbore 28 , the bottom portion of the casing string must be drilled out, including the Testing Assembly Frangible Body 12 and any other cementing equipment placed in the casing string, such as cementing plugs, float collar and float shoe. During this process, the interior of Testing Assembly 2 will also be drilled out, opening the Testing Assembly Frangible Body Outer Cavity 24 , which allows pressure and fluid flow communication between the interior of the Casing 28 and the annulus of the Casing 28 at the Targeted Annulus Testing Site 36 . This is the configuration depicted in FIG. 3C .
[0054] Note that the bottom of the Casing 28 is still blocked by the presence of the set cement. To practice this invention, it is important to determine the location of the Testing Assembly 2 in the Casing 28 during drill out operations. In one embodiment, the Testing Assembly Frangible Body 12 material is designed such that when set it is materially harder to drill than the cement used during the primary cement job. This would give an indication at the surface that the passageway through the Testing Assembly Frangible Body Outer Cavity 24 and the Testing Assembly Tool Body Aperture 10 are open.
[0055] If the Testing Assembly Frangible Body 12 material is cement, this cement could be made of a much higher compressive strength than the cement used for cementing operations. If the testing Assembly 2 is to be used on the tubular string commonly called the surface casing, then a preferred method would use the measured length of the drill pipe to accurately determine what distance would be needed to drill several feet past the tool, prior to testing operations. Surface casing is normally between several hundred to several thousand feet of the surface, which easily is within the accuracy of the drill pipe measurement methods currently in use on drilling rigs.
[0056] Once the passageway to the annulus is opened by the drilling cleanout operations described above, a blowout preventer can be closed to seal the wellbore annulus at the surface. Then, the annular seal can be pressure tested by increasing the pressure in the wellbore to a prescribed pressure, such as by a Formation Integrity Test (FIT), a well-known technique. This approach enables a positive test that the annular is filled with cement, and that no channels exist that will allow migration past that point in the wellbore. This has great advantages over conducting a conventional FIT below the casing shoe to prove the casing annulus is effectively sealed, because, for example, the FIT test is testing the leak off into the formation below the casing shoe, and may be inconclusive as to proving the seal around the casing, such as in the case of natural occurring fractures in the formation or the presence of a higher permeable formation below the casing shoe. Such situations may falsely indicate that the annular seal is leaking during testing operations. Once the pressure test is completed (in a matter of minutes), the cement cleanout continues, and very little time is expended prior to drilling the next section of the wellbore. If the pressure test fails, the invention could be used to squeeze cement into the annulus and seal against migration.
[0057] A negative pressure test may also be performed using the Testing Assembly 2 . A negative pressure test would first involve cleaning out the casing interior to expose the passageway to the annulus. Next, the customary tools to perform a water-shut off test would be run into the wellbore. This process is well known in the industry and is described in great detail in the California Division of Oil and Gas (DOG) publication titled “Testing Oil and Gas Wells for Water Shutoff with a Formation Tester.”
[0058] In other embodiments, the Testing Assembly Tool Body Aperture 10 is drilled after the Testing Assembly Tool Body 6 is constructed. In another embodiment, the Testing Assembly Tool Body Aperture 10 is pre-drilled into the Testing Assembly Tool Body 6 , and plastic tubes are installed to provide a space so that the frangible encapsulating material (such as cement) could be poured and then hardened.
[0059] The overall testing procedure for testing the sealing integrity of an annular seal of a tubular string of a wellbore may be better understood in reference to the following illustrative example, which should not be construed as limiting the functional and operational characteristics of the Testing Assembly 2 . The testing procedure is described with reference to FIG. 4 , which depicts a front elevation sectional view of a pictorial representation of a wellbore prepared for integrity testing. FIG. 4 details a Wellbore 26 drilled from the surface to a producing zone. Wellbore 26 passes through several formation zones. Specifically, wellbore 26 , as descending from the surface, passes through fresh water aquifers, an impermeable zone (e.g. hard rock, shale, impermeable clay), and one or more hydrocarbon bearing zones, to include a targeted producing zone. Surface casing cement is shown to run from the surface through the fresh water aquifers and partially into the impermeable zone. Surface casing typically runs to approximately 2000 ft below the surface. Production casing is shown with cement running from the production casing shoe up through targeted producing zone and stop below a lower hydrocarbon bearing zone. A targeted location within the impermeable zone for integrity seal testing is depicted.
[0060] The sealing integrity (positive) test proceeds as follows:
1. Assuming the invention is placed within ten (10) feet of the cement shoe, after the cement has set up in the wellbore, the cement in the bottom of the casing string is drilled out with a drill bit or other conventional drilling tool. 2. Drilling continues through cement stringers on top of the cementing plug, through the float collar and through the cement in the casing until the drilling bit is approximately five (5) feet from the invention. 3. The pipe rams, or annular preventer on the blow out preventer is closed, and the casing is pressure tested to a prescribed limit to test the integrity of the casing, while taking care, based on the cement mechanical properties, to avoid cracking the cement sheath surrounding the casing. 4. Once the pressure test is completed, the blowout preventer is opened, circulation is established and drilling continues to clean out the cement until the Testing Assembly 2 is contacted with the drill bit and drilled out to at least a depth to create a passageway to the annulus via the tool body aperture. 5. The Testing Assembly 2 may use a harder cement or other frangible material that is more difficult to drill than the cement that was left in the casing after the cement job. This will give a positive indication that the tool has been drilled through. Since the surface casing is normally relatively shallow, the depth drilled may be calculated using the pipe measurements to confirm that the tool has been drilled through. 6. The blowout preventer is closed and the casing is pressured to a prescribed low pressure at the surface, which is then held and may be recorded to note any pressure bleed off at the surface testing the annular casing seal. 7. If the bleed off is within acceptable limits, the test is deemed a success, the annular seal at the bottom of the casing is confirmed by direct measurement through the ports in the casing exposed by drilling past the tool, and drilling operations may recommence into open hole after drilling the casing shoe.
[0068] The sealing integrity (negative) test proceeds as follows:
1. A drill stem test packer is run in the wellbore with the drill pipe evacuated. 2. The packer on the tester is set above the Testing Assembly 2 , which has been drilled out and is opened to measure the inflow from the well, in the manner customarily known as a water shutoff test. 3. If the inflow is within acceptable limits customarily associated with water shut off tests, the test of the annular seal is deemed a success, the drill stem test packer is pulled from the hole, and drill operations are restarted using a drilling assembly.
[0072] To assist in the understanding of the present invention the following list of components and associated numbering found in the drawings is provided herein:
[0000]
Reference No.
Component
2
Testing Assembly
4
Testing Assembly Cavity
6
Testing Assembly Tool Body
8
Testing Assembly Tool Body Interior Surface
10
Testing Assembly Tool Body Aperture
12
Testing Assembly Frangible Body
14
Testing Assembly Frangible Body Proximal End
16
Testing Assembly Frangible Body Distal End
18
Testing Assembly Frangible Body Exterior Surface
20
Testing Assembly Frangible Body Interior Surface
22
Testing Assembly Frangible Body Inner Cavity
24
Testing Assembly Frangible Body Outer Cavity
26
Wellbore
28
Casing
30
Casing Interior
32
Cement Plug One
34
Cement Plug Two
36
Targeted Annulus Testing Site
38
Traditional Casing Float Collar
40
Casing Downhole End
42
Casing Cement Flow
44
Annulus Cement Flow
46
Landed Cement Plug
48
Float Valve
50
Casing Centralizer
51
Casing Shoe
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The present invention provides an apparatus and method for testing a wellbore, and to an apparatus and method to efficiently and effectively test the annular seal of a tubular string positioned within a wellbore. More specifically, the cement seal between a casing string and a wellbore is tested to assure there is no contamination of groundwater or between different geologic formations. An additional aspect of the present invention is to provide a testing assembly comprising a frangible body and a tool body, the tool body providing a passageway to the annular seal when the frangible body is drilled out. In one particular embodiment, the frangible body initially forms an encapsulated bore that aligns with the passageway.
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[0001] The present application claims the benefit of U.S. Provisional Application No. 60/203,684, filed on May 12, 2000, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] Many consumers today have amassed substantial music collections in the CD audio format. The physical aspect of such a large collection however means that a consumer wishing to enjoy their collection from any place other than where the collection is located must make a choice as to which CD to take with them as they move about.
[0003] The primary alternative to date has been for the consumer to record select CD's onto cassette tape or mini-disc mediums to take with them when they leave the vicinity of their music collection. By default, this means the entire collection is not remotely available for the consumer's enjoyment.
[0004] As a newer alternative, the advent of the MPEG-based MP3 file format has enabled consumers to record (rip) their CD's and store them as MP3 files on their personal computers. This does enable a degree of added flexibility, however as the number of files is limited by the available hard disk drive space in the consumer's PC, it is also an inadequate solution. Since a typical album requires approximately 30-60 mb of hard disk space, the storage requirement of this and similar file formats once again forces the consumer to choose which elements of their music collection they want to enjoy instead of having access to the entire collection.
[0005] There is thus a need for a system which allows users both mass storage and portability.
SUMMARY OF THE INVENTION
[0006] The present invention meets those needs.
[0007] In one aspect of the invention, a method is provided for storing audio files. The method includes (a) receiving electronic files at a central location from a first device, those electronic files representing audio signals; (b) associating the audio files with identification information; (c) storing the audio files at the central location on at least a portion of a storage media, that portion being uniquely associated with the identification information; (d) receiving the identification information from a second device; and (e) transmitting the audio files to the second device upon receipt of the identification information.
[0008] In another aspect of the invention, a system is provided for storing and transmitting audio information. It includes a processor, memory, data stored in the memory and instructions executable by the processor. The data identifies a plurality of users or devices and also includes a plurality of files associated with audio information. Each of the files is uniquely associated with the identity of a single user or device. The set of instructions also conditions the transmission of a song from the system to a user or device based on the identity of the user or device associated with the audio information.
[0009] In yet another aspect, a method of storing and transmitting songs includes: uniquely associating a portion of the storage space on a server with a user or device; associating the portion with a first identifier; receiving the first identifier; receiving a song file representative of a song; storing the song file in the portion of the storage space associated with the first identifier; receiving a second identifier and a request for the song file; comparing the second identifier with the identifier associated with the requested song file; and transmitting the song file in response to the request depending upon the outcome of the step of comparing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a functional diagram of a system in accordance with an embodiment of the invention.
[0011] [0011]FIG. 2 is a functional diagram of a content provider in accordance with an embodiment of the invention.
[0012] [0012]FIG. 3 is an example of memory allocation in accordance with an embodiment of the invention.
[0013] [0013]FIG. 4 is a flow chart of operations in accordance with an embodiment of the invention.
[0014] [0014]FIG. 5 is a functional diagram of another content provider in accordance with an embodiment of the invention.
[0015] [0015]FIG. 6 is a functional diagram of device information data stored in a content server in accordance with an embodiment of the invention.
[0016] [0016]FIG. 7 is a functional diagram of a user storage area in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] As shown in FIG. 1, a system 50 in accordance with one embodiment of the invention comprises a network of devices such as end user personal computer 60 , web servers 70 - 71 , PDA 73 and car-audio system 72 , all of which communicate via Internet 80 . Although only a few devices are depicted in FIG. 1, it should be appreciated that a typical system can include a large number of connected devices. Preferably, end user computer 60 is a general purpose computer having all the internal components normally found in a personal computer such as, for example, central processing unit (CPU) 61 , display 62 , CD-ROM 63 , hard-drive 64 , mouse 65 , keyboard 66 , speakers 67 , microphone 68 , modem 69 and all of the components used for connecting these elements to one another. End user computer 60 communicates with the Internet 80 via modem 69 . End user computer 60 may comprise any workstation capable of processing instructions and transmitting data to and from humans and other computers, including network computers lacking local storage capability.
[0018] Also connected to network 80 is a personal digital assistant (PDA) with wireless capability having all the internal components normally found in a PDA such as, for example, a processor 78 , touch-sensitive display 75 , buttons 77 , modem 76 and all of the components used for connecting these elements to one another. The buttons 77 and touch-sensitive display 75 are typically used for data entry. The PDA also includes a headphone jack for use with headphones 74 . The processor executes instructions stored on a storage medium, such as RAM 79 . Although a PDA is shown by way of example in this embodiment of the present invention, it should be understood that the PDA may also comprise other mobile devices, such as Internet-capable wireless phones.
[0019] Car audio system 72 also communicates with Internet 80 via a wireless communication. The car audio system includes a receiver (not shown) for receiving electronic information over the Internet and a speaker (not shown) for playing the audio signals contained in the audio information.
[0020] Web server 70 contains hardware for sending and receiving information over the World Wide Web, such as web pages or files. The web server 70 may be a typical web server or any computer network server or other automated system capable of communicating with other computers over a network, including the Internet, wide area networks or local area networks. For example, the system described above in connection with end user computer 60 may also function as a web server.
[0021] Moreover, the system is not limited to the World Wide Web or the Internet but, rather, is applicable to any network allowing remote communication to a central storage area by multiple devices.
[0022] As shown in greater detail in FIG. 2, web server 70 functions as a content store and contains a processor 102 , a set of instructions 104 which are executed by processor 102 and data such as user storage area 110 . The functions, methods and routines of the program are explained in more detail below. Although the data is shown separately from the instructions, the data may be modified by the processor during execution of the instructions. Moreover, both the data and the instructions may be stored as a program on the hard disk of the server 70 .
[0023] User storage area 110 is used to store the user music files 114 uploaded by the users. Preferably, each user has a predefined amount of space allocated to its sole use, and no other user is permitted unauthorized access to any information stored in its particular space. Each user has a User ID 112 which identifies the space allocated to the user. For illustration purposes, three different user spaces are schematically shown in FIG. 2 for users with ID's “User1”, “User2” and “User3”. User 1 has three music files stored in its space, including files called “File1”, “File2”, and “File3” corresponding with songs named “SongA”, “SongB” and “SongC”, respectively. User 2 also has a file stored in its space designated as “File4”. However, as indicated by the “SongA” label in parenthesis next to “File4”, that file may be the same song as—and byte for byte a copy of—“SongA” contained in File 1 of User 1 . File 1 and File 4 may also be quite different even if the song is the same, such as if the same song was encoded at two different frequencies. FIG. 2 also shows User 3 as having three music files, “File5”, “File6” and “File7” corresponding with “SongD”, “SongE” and “SongA” (again), respectively.
[0024] The manner in which songs are stored and occupy user storage area 100 is also shown schematically and to scale in FIG. 3. In the diagram, the width of a cell relates to the size of the associated file. The width of each cell in row 150 relates to 1 MB of data. As can be seen, assuming that each user has stored the exact same copy of the SongA music file, the music file will take up the same amount of space in each individual user's space 152 - 54 . If desirable, the system may limit each user to a particular amount of storage space, such as 100 megabytes of music.
[0025] In operation in accordance with one embodiment, music is stored on the server in accordance with the steps shown in the flowchart of FIG. 4. First, the user encodes audio compact discs from red book format or an analog source into electronic digital files (step 202 ). The files are preferably compatible with MPEG-3 format or Sony's ATRAC3 format and are encoded with a general purpose computer, such as computer 60 , or a dedicated device. The user then causes end user computer 60 to access the content server 70 via the Internet 80 (such as by logging onto a web page) (step 204 ), supplies its User ID 112 (step 206 ) and then uploads the files to the content server 70 (step 208 ). Using the foregoing example of FIG. 2, User 1 would take a compact disc it owned, encode “SongA” as a digital file on end user computer 60 and upload the digital file to the content server 70 via Internet 80 . In so doing, the user identifies the song with a string, such as “File1”.
[0026] Upon receipt of the User ID 112 and the song file, processor 101 of server 70 in accordance with instructions 104 first checks the size of the file to make sure that the user has not exceeded its space limit (step 209 ). If the user has, then an error notification will be sent to the user explaining the problem (step 211 ). Otherwise, processor 101 will store the uploaded file into the space allocated for the particular user (step 210 ), and associate the file with the identifying string provided by the user.
[0027] The operation of downloading the music is also shown in FIG. 4. In this embodiment, the user accesses the content server 70 (such as by logging onto a web page) via PDA 73 which, for the purposes of this example, shall be considered to be at a geographic location remote from end user computer 60 (step 220 ). In other words, although the user uploaded the songs with one device, the user may download the songs at a different location with a different device. The user accesses the web site maintained by content server 70 by using wireless modem 76 in a manner well known to those of ordinary skill in the art. The user next supplies its User ID to content server 70 by entering the information on a web page displayed on screen 75 (step 222 ). For example, the user may identify itself as “User1” (it is recommended, but not required, that user names be more arbitrary than a designation of “User1” for security reasons). Optionally, the song may be identified at the same time as well. Processor 101 of server 70 searches user storage area 110 to see whether there is any user associated with that particular ID (steps 224 and 226 ). If the user ID is not found, an error notification is sent to the user to that effect (step 211 ).
[0028] If the user ID is found, the server 70 checks whether it has already been provided with an identification of the song to be downloaded (step 228 ). If not, then server 70 may, optionally, send a list of the identifying strings to the user (step 230 ). For example, server 70 would send the strings “File1”, “File2” and “File3” if the songs matched the illustrative examples in FIG. 2. These strings could be displayed on screen 75 . Content server 70 next prompts the user to enter the identifier for the song, which may be entered via touch-screen 75 (step 232 ).
[0029] The identifier for the song is checked against the list of songs associated with that user (step 234 ). Using the example values of FIG. 2, the string “File1” would be valid identifier because there is a song file having that identifier contained in User 1 's space. The string “File4”, on the other hand, would not be a valid identifier even though it points to a byte-for-byte identical file with the same name in User 2 's space. Accordingly, the identifier must identify a song contained in the respective user's space. If the song with that identifier is not contained in the space allocated to that user in user storage user 110 , the user is notified of the error (step 211 ).
[0030] If the song is validly identified, the song is then sent from the server 70 to the PDA 73 (step 236 ). Once downloaded, the song may then be played by the user (step 240 ).
[0031] Accordingly, each user is assigned a unique identification code such that the user (or the entity to whom the user gives the code) is the only entity that can upload and download music to and from the storage space allocated to the user. This identification code is sent with, or before, the steps of uploading and downloading and is used to verify that the requester is the user associated with the particular storage space. It is not necessary for the server to set aside, in advance, actual portions of the storage space to particular users. Rather, the files may be first stored (and thus occupy a portion of the hard drive of the server) and access permissions set for the file set in accordance with the identify of the user.
[0032] After the music is uploaded by the user to the central location, it may be played anywhere by any device capable of connecting with the server. For example, if the online service provider hosts a website, the user provides its unique identification code and the online service provider authenticates the user. The user may then download, via the internet, a copy of one or more of the music files that had been uploaded by the user.
[0033] Rather than downloading the music, the music may also be streamed to the user. Security choices may dictate whether the music file is served via a streaming process or a download, as streaming places more of a requirement on the connection but downloads place more of a resource requirement on the device. For the purposes of this disclosure, the word “download” should be understood to include real-time streaming regardless of whether the transmitted information may be permanently and locally stored.
[0034] One of the advantages of the system is that there is a copy of a song for every user, rather than giving one copy of a song to multiple users. Moreover, the user is responsible for maintaining the songs stored in their space. Thus, the invention facilitates respect for copyright owner's rights to prevent multiple unauthorized parties from downloading the same song.
[0035] Preferably, the system provides music to dedicated devices by automatically authenticating the devices upon connection. In such an embodiment, each device that accesses songs stored in content server 70 has an identifier which is unique to the system. For example, such an identifier may be a GUID. The unique identifier may also be a number stored in the RAM or other readable/writable storage media of the device, such as RAM 79 of PDA 73 . This information may be stored in the user storage area of content server 70 as shown in FIG. 7. For each User ID 612 in the user storage area, there are not only songs 614 but also a list of device identifiers 616 . For example, the identifier “Device1” may be the value of the device identifier stored in a network-enabled Walkman® player operated by User 1 , “Device2” may be the value of the device identifier stored in the car audio system 72 operated by the same User 1 , “Device3” may be the value of the device identifier stored in end user computer 60 operated by User 1 , and “Device4” may be the value of the device identifier stored in a Clie™ PDA operated by User 1 .
[0036] In one possible operation of such a system, the device connects with the content server via the Internet (FIG. 4; step 250 ). The device automatically transmits its unique identifier (step 252 ). In response, the processor of the content server searches the device identifiers 616 to determine the associated user ID (step 254 ). If a user ID is found, then the process proceeds as described above.
[0037] Preferably, the system also has the ability to limit the number of songs that a consumer can download or stream to, either simultaneously or in total. In such an embodiment and as shown in FIG. 6, each content server 70 counts how many times a file has been downloaded. The processor also decrements that value each time it is downloaded. For example, if a device designated as “Device1” was given a trial period to listen to Song A, then content server 70 may store the value “5” in the Copies Left field 513 of the user storage area, thus indicating that the device may download the song 5 times. Each time the song is downloaded, the value decrements. For example, FIG. 6 shows that “Device2” may only download the song 3 more times. However, if SongA were purchased, then the device would be able to download the song any number of times (such as is shown for “Device3”).
[0038] Limiting the authorization to a particular device or user has its own unique advantages. If the authorization is limited to a particular user ID, which is not wedded to a particular device, then a user may grant access to friends and associates by passing along his or her ID. On the other hand, if a more secure environment is required, then the device ID may be hardwired into the unit, such as GUID. Preferably, the content server 70 will allow both possibilities. Thus, certain songs, such as sound clips, may be freely transferable provided you have a particular user ID. Different songs, on the other hand, would be limited to a specific number of plays on a particular device. Access can thus be limited to particular devices or could provide the user with full “owner” access.
[0039] In another embodiment, the user does not encode and upload the song themselves. Rather, the user buys a copy of the music from the content server 70 and the file is stored in the user's space. Specifically, as shown in FIG. 5, content server 70 includes a database of music selection. This database, song bank 400 , stores a plurality of songs as music files. The songs are designated by name 401 , a description 402 and the price of the song 403 .
[0040] In the operation of this embodiment, the user will access the content server and obtain a list of music selections which are available for use (step 302 of FIG. 4). For example, a list of the songs, their descriptions and prices may be sent as a web page to end user computer 60 . The user selects the songs that they would like and then transmits that information, along with their User ID, to the content server 70 (step 304 ). For example, “User 2” may indicate that they wish to listen to “Song X”. Upon receiving the name of the song from the user, processor 101 then extracts the file associated with the song from the song bank 400 (step 306 ). The process then proceeds as if the song had been uploaded by the user, i.e. the processor 101 checks the size of the selected song against the space remaining available to the user (step 209 ). If there is enough room, the song is stored in the area allocated to the particular user (step 210 ) as schematically indicated by the dashed arrow in FIG. 5. Accordingly, in this embodiment, even when a copy of the song is available on the server, yet another copy of the song will be stored in the user's space in user storage area 110 . The database may also be contained at a separate site or server, such as server 71 of FIG. 1.
[0041] The embodiment shown in FIG. 2 permits other interesting options and variations. For example, the system may deploy a security system such as those currently being contemplated by the music industry for online use such as SDMI. The user may be able to “check” particular songs in and out of song bank 400 . If one user has loaded the song onto its system, then no other user would be permitted to listen to the song, thus preventing multiple parties from simultaneously playing or using the same song. Such an embodiment may be implemented as shown by step 702 of FIG. 4, whereby a song may only be uploaded into a user's space if it is not checked out to someone else. The song could be checked back in in any number of different ways, such as the user simply informing the content server that it has finished listening to the song or counting the number of streaming downloads (as discussed in connection with FIG. 6) and checking it back in when the Copies Left field 513 reaches zero. In other words, the system is geared to prevent unauthorized multiple copies of a single authorized copy. This helps prevent piracy and the inappropriate use of the music collection stored on the network.
[0042] Another one of the myriad advantages of the present invention is that users are able to access music from any location without having to carry media containing the music. A user may place a copy of its music at a central location and play that music from any remote location. Another advantage is that the authentication mechanism protects third party's rights in the user's music but still preserves the foregoing advantage of portability. Moreover, by providing a unique storage area at a central location, the user can access the music regardless of whether or not the device used to encode or upload the music is powered on or not. In other words, the consumer may upload their entire music collection to a system server operated as an independent service and will then be able to access the entire collection from anywhere in the world, from any device connected to the Internet and equipped with audio-enabled and browser technology. The rapidly advancing availability of wired and wireless Internet connectivity means a music-loving consumer can readily access their entire collection from any place they can connect.
[0043] Another advantage of the invention is that it can accommodate security requirements. For example, the central server may also check music for security limitations before permitting the music file to be stored.
[0044] Additionally, because the user is able to upload the music they want, the user can create unique compilations in accordance with the user's personal preferences. The user can thus create compilations directed to particular genres of music (such as dance or exercise). Optionally, the user may also change the order that the songs are downloaded or streamed.
[0045] In another implementation, the first time the consumer plays a new CD they are adding to their collection, their Internet connected CD player or changer would upload the file to the network server for storage. This upload process could be implemented in variety of ways including the disc-by-disc upload from the CD-ROM drive of a PC connected to the Internet or from a new service-based business designed to transfer the consumer's collection in total. The file format used could be any of the known or to be developed formats given file size, sound quality, and security trade-offs.
[0046] In addition, because the network is functioning as the storage facility for the consumer's audio collection, the network could employ preference mining techniques as to the collection's content and frequency of use as well as device context. Such data mining would enable the network to actually recommend selections from the collection to match particular activities or to suggest new music which might be enjoyed by the same consumer.
[0047] Unless stated to the contrary, use of the words such as “including,” “containing,” “comprising” and the like, means “including without limitation” and shall not be construed to limit any general statement that it follows to the specific or similar items or matters immediately following it.
[0048] Most of the foregoing alternative embodiments are not mutually exclusive, but may be implemented in various combinations to achieve unique advantages. As these and other variations and combinations of the features discussed above can be utilized without departing from the invention as defined by the claims, the foregoing description of the embodiments should be taken by way of illustration rather than by way of limitation of the invention as defined by the claims.
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In one aspect of the invention, a method is provided for storing audio files. The method includes: (a) receiving electronic files at a central location from a first device, those electronic files representing audio signals; (b) associating the audio files with identification information; (c) storing the audio files at the central location on at least a portion of a storage media, that portion being uniquely associated with the identification information; (d) receiving the identification information from a second device; and (e) transmitting the audio files to the second device upon receipt of the identification information.
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The present application claims priority to German Patent Application No. 10 2011 106 942.2 filed on Jul. 8, 2011, which said application is incorporated by reference in its entirety herein.
FIELD OF THE INVENTION
The present invention relates to a bending apparatus for rod-shaped workpieces.
BACKGROUND OF THE INVENTION
With bending devices it is frequently desired that there be only a short, straight end piece between the cutting plane and the last bend which the bending head produces.
A bending device is known from EP 0 379 030 B1 (corresponding to DE 690 03 116 T2) in which upstream of the bending head, a cutting device is provided that can be moved in feed direction of the workpiece. It is thus possible to vary the distance between the end of the workpiece produced after cutting and the bending head. However, with this known bending machine, the cutting device, even in its position moved furthest towards the bending head, is still a clear distance from the bending head. As a result, there is in every case a relatively long straight end piece of the workpiece between the cutting point and the bending head.
In DE 10 2009 024 075 A1, a bending device for rod-shaped workpieces is described in which the cutting device mounted upstream of the bending head can likewise be shifted in feed direction of the workpieces. The bending head is attached to the front end of the machine frame, wherein the cutting device can be moved up to a frontmost position in which it is situated immediately in front of the bending head. Although the cutting plane of the cutting device can thus be moved up fairly close to the bending head, in different cases of application this still leads to a straight end piece which turns out to be longer than desired.
In order to still further shorten such relatively short straight end pieces between the last bend in the workpiece and its end, with known bending devices the workpiece has previously been moved backwards via the feeder (or a movable feeder) and the last bend already produced positioned at the cutting unit, in order to make a cut in this position. However, the required reversal of the conveyance direction of the workpiece leads to an undesired reduction in the machine's throughput. In addition, some bending devices also have no movable feeder, in which case it is not even possible to convey the workpiece backwards. Moreover, a rearward conveyance of the workpiece via the feeder is also very problematic when large workpiece diameters are used.
SUMMARY OF THE INVENTION
As a result of the problems in the prior art, an object of the present invention is to provide a bending device such that it is also possible to cut off the workpiece quite close to its last bend with no, or only an extremely short, straight end piece, without the need for a movement of the workpiece.
According to certain aspects of the present invention, this objective is achieved with a bending device for rod-shaped workpieces having a bending head, which in order to assume its operating position, can be moved into the travel path of the cutting device, whereas, after assuming its inactive end position, it lies completely outside the travel path of the cutting device, and in that, when the bending head is situated in its inactive end position, the cutting device can be moved downstream on its travel path at least partly over the area of the operating position of the bending head, i.e. the area of the travel path which the bending head occupies in its operating position.
According to certain aspects of the present invention, a bending device for rod-shaped workpieces has a bending head with a mandrel rotatable about a rotation axis, a cutting device for cutting the respective workpiece in a cutting plane, and downstream of the bending head, a feed and straightening device for feeding the workpieces to the bending head, wherein the cutting device can be moved along a travel path in feed direction of the workpieces and the bending head can be shifted between an operating position in which it is moved up to the workpiece and an inactive end position remote therefrom.
With the bending device according to certain aspects of the present invention, an arrangement is thus used in which the bending head can be shifted between an operating position in which it can process the workpiece and in which it protrudes into the travel path of the cutting device, and an inactive end position remote from the latter, wherein, when it assumes the inactive end position, it lies outside the travel path of the cutting device. The travel path of the cutting device extends downstream at least partly into the area of the operating position of the bending head or even beyond this area.
In certain aspects of the present invention, if the bending head is in its operating position, it protrudes into an area of the travel path of the cutting device, with the result that in this situation the cutting device cannot be moved along its entire travel path, in order not to collide with the bending head in its operating position. However, if the bending head has been moved out of its operating position into its inactive end position, in which it is wholly situated outside the travel path of the cutting device, the cutting device can then also be moved as far as the downstream end of its travel path (seen in feed direction of the workpiece). This configuration makes it possible, after moving the bending head into its inactive end position, to move the cutting device (at least) partly over the area of the operating position of the bending head so far that it has moved right up to the beginning of the last bend formed by the bending head on the workpiece, and only there can it be activated for cutting.
The bending device according to certain aspects of the present invention is particularly preferably designed such that the cutting device can be moved at least so far downstream over the area of the operating position of the bending head, i.e. the area occupied by the bending head in its operating position, that it can reach a movement end position in which the cutting plane lies downstream of the position assumed by the rotation axis of the mandrel of the bending head when the latter has been deployed into its operating position. In certain aspects, this embodiment allows the cutting device to be moved so far that it can quite safely be moved up to the beginning of the last bend in the workpiece formed by the bending head.
In further certain advantageous aspects of the present invention, the bending device can be provided such that the cutting device can travel over the whole of the area of the operating position of the bending head when the latter is situated in its inactive end position, particularly preferably that the cutting device can even be moved further downstream beyond the area of the operating position of the bending head, particularly preferably it can even be moved as far as the end of the machine frame. Quite specific advantages of a bending device according to the present invention can be achieved with these embodiments.
In certain aspects of the present invention, if the cutting device is arranged so that it can travel over the whole of the area of the operating position of the bending head, this provides the possibility that a workpiece can be lowered only in front at the end face of the machine, for which the bending part in question is moved out forward beyond the bench, the cutting device is moved as far as the end of its travel path over the area of the operating position of the bending head and optionally even as far as the end of the machine frame, thus as far as the edge of the bench, and only there is the cut activated (wherein in this case the bench recess must of course be correspondingly adapted).
Completely different positions for depositing the processed workpieces can thus be achieved with the bending device according to the present invention.
In certain aspects of the present invention, a further advantageous possibility is also provided if, before cutting, the workpiece is conveyed still further forward beyond the supporting bench of the machine onto a further support bench or other reception device and only then is the cutting device activated e.g. in a middle position or at the end of the bench, thus allowing particularly easy removal of the workpieces over the end face of the bending device.
In certain aspects of the bending device according to the present invention, because by moving the bending head out of the travel path of the cutting device the possibility is created (solely by moving the cutting device into the area of the operating position of the bending head, or even beyond the latter) to place the cut where it is desired without the possibility of a collision with the bending head, workpieces with cuts that take place immediately at the last bend or very shortly before it can be produced without difficulty and without the workpiece having to be moved in any way. Since it is completely unnecessary to reverse the movement of the workpiece, not only is it possible to achieve a somewhat higher workpiece throughput with the bending device according to the present invention, but it can also be used for workpieces with relatively large diameters in the case of which a reversal of the movement of the feeder was previously simply not possible.
In certain aspects of the present invention, the bending head can be brought from its active operating position into its inactive end position (and vice versa) in any suitable manner. However, it is quite particularly preferred if the bending head can be moved by being made to travel in the direction of the rotation axis of the mandrel out of its operating position into its inactive end position or vice versa. Then, after the last bending process has been carried out, the mandrel can quite simply be moved perpendicularly out of the previous bending plane and brought into its other end position without further corrective movements of the mandrel being required in order to allow departure from the bending plane without changing the position of the workpiece.
A quite particularly preferred embodiment of the bending device according to certain aspects of the present invention also provides that the cutting device comprises a support arm aligned perpendicularly to the feed direction of the workpiece, which support arm has a movable cutting blade and a stationary counter-blade fixed to the support arm in the feed direction of the workpiece directly in front of this cutting blade, wherein the cutting plane is established between the two adjacent blades. Furthermore, the support arm protrudes into the feed axis of the respectively conveyed workpiece and the workpiece coming from the feed device can be cut through while passing the cutting blade and the counter-blade in the cutting plane established between the two. This results in a relatively simply structured embodiment of the bending device according to the present invention, which can be produced inexpensively and allows a problem-free implementation of the method according to the present invention.
According to certain aspects of the present invention, a particularly preferred embodiment of the bending device furthermore comprises the bending head being situated in a bending-head housing from which it can be moved out in order to assume its active operating position and into which it can be moved in order to assume its inactive end position. With this embodiment, if it has assumed its inactive end position inside the bending-head housing, outside the latter, where the bending head is moved out in its active operating position, the cutting device can be moved on top of the bending-head housing, while the bending head is accommodated, protected from the processes, inside the bending-head housing during the movement of the cutting device.
With such an embodiment, the support arm of the cutting device is preferably movably supported on linear guides at its end area facing away from the supplied workpiece against a rear wall of the machine frame or of the bending-head housing parallel to the workpiece. Thus, when displaced by the bearing on the back of the machine frame or bending housing, it can be guided precisely parallel to the workpiece, while the support arm, when moved, is guided above the machine frame or the bending-head housing respectively, at a distance therefrom and at the same time the area of the operating position of the bending head can be traversed without difficulty.
In certain aspects of the present invention, the bending-head housing can preferably be formed such that it can also still be movably attached to the machine frame parallel to the feed direction of the workpiece.
In certain aspects of the present invention, the bending apparatus for rod-shaped workpieces comprises a bending head having a mandrel rotatable about a rotation axis, the bending head moveable between an operating position, in which the bending head comprises an operating area and operably engages the respective workpiece, and an inactive end position remote therefrom, a feed device and a straightening device, the feed and straightening devices operably located in an axial direction from the bending head, and a cutting device for cutting the respective workpiece in a cutting plane, wherein the cutting device is configured such that it is moveable along a travel path in a feed direction of the workpieces from the feed and the straightening devices to the bending head, and wherein the bending head in the operating position is located in the travel path of the cutting device, and the bending head in the inactive end position is positioned outside the travel path of the cutting device such that the cutting device can be moved in a downstream direction on the travel path toward the location of the bending head such that the cutting device is capable of being located at least partly within the operating area of the bending head.
In certain aspects, the cutting device is moveable in the downstream direction such that the cutting plane is located upstream of the position of the rotation axis of the mandrel of the bending head in its operating position.
In certain aspects, the cutting device is moveable in the downstream direction such as to completely traverse the operating area of the bending head when the bending head is in the inactive end position.
In certain aspects, the cutting device is moveable in the downstream direction such that at least a portion of the cutting device is located beyond the operating area of the bending head.
In certain aspects, the cutting device is moveable in the downstream direction as far as an end of a machine frame of the bending apparatus.
In certain aspects, the bending head is moveable between the operating position and the inactive end position along a direction of the rotation axis of the mandrel.
In certain aspects, the cutting device comprising a support arm aligned generally perpendicular to the feed direction of the workpiece
In certain aspects, the support arm has a movable cutting blade, and a stationary counter-blade, the cutting blade and the stationary counter-blade defining the cutting plane.
In certain aspects, the stationary counter-blade is fixed to the support arm in the feed direction of the workpiece.
In certain aspects, the support arm protrudes as far as the respectively conveyed workpiece.
In certain aspects, the support arm of the cutting device is movably supported on one or more linear guides.
In certain aspects, the bending head is situated in a bending-head housing from which it can be moved out in order to occupy its operating position and into which it can be moved to occupy its inactive end position.
In certain aspects, the cutting device comprising a support arm aligned generally perpendicular to the feed direction of the workpiece, wherein the support arm is movably supported on one or more linear guides proximally located on a machine frame of the bending apparatus.
In certain aspects, the bending-head housing is movably attached to the machine frame parallel to the feed direction of the workpiece.
DESCRIPTION OF THE DRAWINGS
The present invention is explained in more detail in principle by way of example with reference to the drawings, wherein:
FIG. 1 shows a top diagrammatic perspective view of a bending device according to the present invention, the bending device having a supporting bench viewed at an angle from above from the front;
FIG. 2 shows a perspective view of the bending device in FIG. 1 , but viewed at an angle from the back and without a supporting bench;
FIG. 3 shows a top perspective view of the machine from FIGS. 1 and 2 , the bending device having the supporting bench removed and the bending device illustrated in the configuration after a bending process;
FIG. 4 shows a top perspective view from FIG. 3 , but in the cutting position;
FIG. 5 shows a diagrammatic view of a detail of the upper part of the bending device from FIGS. 1 to 4 , viewed in the direction parallel to the supporting bench, before the workpiece is fed into the bending head;
FIG. 6 shows a diagrammatic view from FIG. 5 , but after a cutting process; and
FIG. 7 shows a diagrammatic view from FIG. 5 , but with cutting device located in the cutting position.
DETAILED DESCRIPTION
FIGS. 1 to 4 show a diagrammatic perspective representation of a bending device 1 , wherein in the view in FIGS. 1 , 3 and 4 the chosen viewing direction is at an angle from above from front to back, and in the view in FIG. 2 the chosen viewing direction is at an angle from above from back to front.
The bending machine 1 comprises a machine frame 2 and a housing 3 mounted thereon, in which a feed device 4 in the form of a roller feed with three pairs of series-connected rollers is rotatably mounted.
Two straightening devices 5 offset by 90° to each other are situated at the back of the housing 3 , are connected to the rotatable feed device 4 , and can be twisted with the latter about the central axis of a workpiece 11 in the form of a wire.
Arranged in front of the end face 6 of the housing 3 are a bending head 7 , bearing a mandrel 8 at the top, which is rotatable about a rotation axis 9 ( FIGS. 2 and 3 ), as well as a cutting device 10 which can be moved along a travel path in direction a (workpiece-feed direction).
In the representation of FIG. 1 , an inclined supporting bench 18 , which supports the workpiece 11 during production, rests on top of a bending-head housing 20 . Corresponding to the inclination of the supporting bench 18 , the bending head 7 and the cutting device 10 are also arranged equally inclined to the horizontal, in order that, after cutting, the finished workpieces 11 can drop down. The supporting bench 18 (not shown in detail in the figures) is height adjustable, and the entire bending-head housing 20 can also be moved parallel to the longitudinal direction of the workpiece 11 (also not shown in the figures).
To show the structure of the bending device 1 clearly, the supporting bench 18 is no longer shown in FIGS. 2 to 7 .
The bending head 7 is mounted in the bending-head housing 20 , which has an opening 21 on top through which the bending head 7 can be moved into the bending-head housing 20 or moved out of it. The outward and/or inward movement takes place in a direction b (cf. FIG. 3 ), namely in the direction of the rotation axis 9 , perpendicular to the wire 11 . In certain aspects, as illustrated in FIG. 3 , the rotation axis 9 and/or direction b are generally perpendicular to the travel path direction a.
Also situated on the bending-head housing 20 is the cutting device 10 which, as shown by FIG. 2 , comprises a support arm 12 which has a movable cutting blade 14 and, directly next to the latter, a fixed counter-blade 13 . The two blades 13 , 14 between them establish a cutting plane 22 , as can best be seen from the representations in FIGS. 5 to 7 . The movable cutting blade 14 is driven via a motor 25 . In certain aspects, as illustrated in FIG. 3 , the cutting plane 22 is parallel to the rotation axis 9 and/or direction b, and when moved in travel path direction a as shown in FIG. 4 , can be in the same plane as rotation axis 9 . Thus, in certain aspects, the cutting plane 22 is generally perpendicular to the travel path direction a.
FIGS. 5 to 7 show quite diagrammatically and in a viewing direction parallel to the supporting bench 18 a detailed view of the upper part of the bending-head housing 20 with different positions of the bending head 7 .
FIG. 5 shows the situation before the operating position of the bending head 7 is reached, thus before the workpiece 11 is fed into the bending tool.
FIG. 6 shows the situation in which the bending head 7 is in its operating position and has made a bend in the workpiece 11 (as shown in FIG. 3 ).
Finally, FIG. 7 shows how the bending head 7 has travelled into the bending-head housing 20 into its inactive end position and the cutting device 10 has already travelled over a section of the area of the operating position of the bending head 7 .
As is shown clearly by FIGS. 5 to 7 , the workpiece 11 runs past the two blades 13 , 14 in two grooves (not shown) each attached to the two blades 13 , 14 , aligned relative to each other and in feed direction of the workpiece 11 and is sheared upon activation of the cutting device 10 when the movable cutting blade 14 moves relative to the stationary counter-blade 13 in the cutting plane 22 .
In certain aspects of the present invention, the bending device 1 is a wire bending machine, the feeder of which continuously pulls in the workpiece 11 , namely a wire, from a coil (not shown) through the straightening units 5 . The rotatable design of the feed device 4 and the straightening devices 5 allows the wire 11 to be bent in different planes.
As FIG. 2 shows, the support arm 12 of the cutting device 10 is attached at its end area lying on the back of the bending-head housing 20 to a support 23 which for its part is movably supported on two parallel linear guides 15 .
Shown between the linear guides 15 , parallel thereto, is a rack 17 , represented only quite diagrammatically in FIG. 2 , with which a gear 24 engages, which for its part can be driven in both rotation directions via a motor 16 fastened to the support 23 and wherein the support 23 with the support arm 12 and the blades 13 , 14 can be moved along the linear guides 15 .
If the cutting device 10 is moved along the linear guides 15 , it moves on top of the bending-head housing 20 , at a slight distance therefrom, along a travel path that runs parallel to the feed direction of the wire 11 .
In order to carry out the bending processes, the bending head 7 with the mandrel 8 can be moved out of the bending-head housing 20 through the opening 21 along direction b into an outer end position which is to be called the “operating position” and in which it can enter into effective engagement with the mandrel 8 in order to carry out the desired bending processes with the wire 11 . When moving out into this operating position, the wire 11 is fed into the bending tool.
This deployed operating position is shown in FIGS. 3 and 6 ; however, in each case already at a point in time after a bending process has been carried out.
If several bending processes, between which the cutting device 10 is not activated, are carried out in succession, the bending head 7 can be moved out of its deployed operating position ( FIG. 6 ) into an intermediate position lying approximately vertically away from the wire 11 (direction b) as shown in FIG. 5 : however, in this intermediate position, the top of the bending head 7 with the mandrel 8 still lies outside the bending-head housing 20 and is only so far away from the wire 11 that there is just no longer any effective engagement between the bending tool and the wire 11 . The wire 11 can then be advanced unimpeded and, as soon as a new bending process is required, the bending head 7 is returned to its operating position (in direction b) ( FIG. 6 ).
However, if the bending head 7 is now no longer required during the processing of the respective workpiece 11 , but the cutting device 10 is ready for activation, the bending head 7 is retracted into the bending-head housing 20 in direction b, vertically away from the wire 11 and through the opening 21 , until it assumes its inactive end position in the retracted state.
The consequence of this retraction of the bending head 7 into the bending-head housing 20 is that the bending head 7 has completely disappeared from the travel path along which the cutting device 10 can be moved in feed direction of the wire 11 at the bending-head housing 20 , with the result that the cutting device 10 can now be moved with its support arm 12 protruding as far as the wire 11 and its blades 13 , 14 into the area of the opening 21 , even into the area occupied by the bending head 7 in its deployed operating position, without the risk of a collision of the cutting device 10 with the bending head 7 .
The linear guides 15 correspondingly extend as far forward at the back of the bending-head housing 20 as a movement of the cutting device 10 downstream is desired. In the representation shown in FIG. 2 the length of the linear guides 15 is chosen such that the cutting device 10 can be moved over the entire width of the opening 21 and thus also over the entire area of the effective engagement of the bending head 7 along its travel path if the bending head 7 is in its retracted inactive end position.
Equally, the linear guides 15 could however also be made so long (not shown in the figures) that they actually extend beyond the area of the opening 21 and thus the area of the effective engagement of the bending head 7 as far as the end face of the entire machine, in order, if desired, to move the bent part produced from the wire 11 before cutting forward only as far as the end of the supporting bench 18 and to activate the drive 25 of the cutting device 10 only at the edge of the supporting bench 18 , after which the produced part can be immediately removed on the front at the bending device 1 .
If the bending head 7 has been retracted into its inactive end position in the bending-head housing 20 in direction b and the cutting device 10 has then travelled over the entire open opening 21 in direction a, a situation results as shown in FIG. 7 . In this representation the cutting plane 22 is situated only very slightly upstream of the point where, with the bending head 7 deployed into its operating position, the rotation axis 9 of the mandrel 8 would be situated.
If the representations in FIGS. 3 and 4 are compared with each other, then in FIG. 3 the bending head 7 has made a bend of 90° (downwards in the graphic representation in FIG. 3 ) in the wire 11 and the cutting device 10 lies immediately in front of the opening 21 of the bending-head housing 20 , i.e. only a very short distance from the bending head 7 which is in its deployed operating position.
FIG. 4 shows the situation when the wire 11 provided with the bend according to FIG. 3 is to be cut off quite close to the beginning of the bend produced.
For this purpose, as shown in FIG. 4 , the bending head 7 has been lowered through the opening 21 into its retracted, inactive end position inside the bending-head housing 20 perpendicular to the wire 11 (in direction b), after which the cutting device 10 is retracted in direction a with the two blades 13 , 14 into the area occupied by the bending head 7 in its operating position ( FIG. 3 ), so far that the bent leg of the wire 11 has come to rest against the front face of the movable blade 14 . In this position the cutting plane 22 is situated very close to the point at which the bend made in the wire 11 begins. If the cutting process is now started, this front, bent part of the wire 11 falls onto the inclined surface of the bending-head housing 20 , from which it can drop down.
If, however, during this process the cutting plane is to lie exactly at the point where the last bend of the previously bent wire 11 begins, i.e. so far as possible without a short straight piece of wire in front, then before the activation of the cutting device 10 by rotation of the feeder the bent leg of the wire 11 is swivelled upwards, with the result that it no longer lies against the front side of the movable blade 14 , lying in front. The support arm 12 can thereby be moved downstream until the cutting plane 22 established between the two blades 13 , 14 has moved up to the beginning of the last bend of the wire 11 , after which the cutting device 10 is then activated.
In order to ensure an undisturbed and continuous operation with the bending device 1 shown in the figures, the bending device 1 is connected to a machine controller (not shown in the figures) which is designed such that it allows a retraction of the cutting device 10 into the area occupied by the bending head 7 in its deployed operating position only when the bending head 7 is retracted into its inactive end position in the bending-head housing 20 , in which, as shown by the figures, in particular FIGS. 5 to 7 , it is located wholly under the beam or support arm 12 of the cutting device 10 , with the result that in this way a collision of the cutting device 10 retracting into the operating position of the bending head 7 (or of its support arm 12 with the blades 13 , 14 ) with the bending head 7 moved from its operating position is safely avoided.
With the bending machine according to the present invention an arrangement is in principle achieved in which the bending head can be moved into an active operating position in which it protrudes into the travel path of the cutting device, and out of the latter into an inactive end position in which it is arranged completely outside the travel path, and vice versa and, as a result of this departure from the travel path, the usable travel length of the travel path is increased so that the area of the travel path into which the bending head protrudes in its operating position can then also be completely or also only partly traversed.
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A bending device for rod-shaped workpieces having a bending head with a mandrel rotatable about a rotation axis, a cutting device for cutting the respective workpiece in a cutting plane, and a feed and straightening device for feeding the workpieces to the bending head, the cutting device capable of being moved along a travel path in the feed direction of the workpieces, with the bending head capable of being shifted between an operating position in which it is moved towards the workpiece and an inactive end position remote therefrom, the bending head, in order to assume its operating position, can be moved into the travel path of the cutting device, whereas, when assuming its inactive end position, it is positioned outside the travel path of the cutting device, and, when the bending head is situated in its inactive end position, the cutting device can be moved downstream on its travel path at least partly over the area of the operating position of the bending head.
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FIELD OF THE INVENTION
This invention relates to a power and data station to supply electric, phone, video and data lines into a work surface, such as a conference table, boardroom table or office desk.
BACKGROUND OF THE INVENTION
There is a need for an aesthetically pleasing method of supplying electric, phone and data lines into conference and boardroom tables. Present solutions to this problem generally involve a metal box with or with out a lid, making it difficult for a designer to integrate it into furniture in a pleasing manner. Some designers solve this problem by recessing the box beneath a hinged access door, but this creates the problem of how to open the door, and how to avoid damaging the adjacent surface of the table while doing so.
Other designers offer interfaces that raise and lower the device, but these are all dependent on expensive electric devices to raise and lower the interface, resulting in a very expensive unit prone to failures of opening and closing.
BRIEF DESCRIPTION OF THE INVENTION
This invention provides a station device, called herein a power and data station, for carrying electric, phone, video and data lines into work surfaces, such as conference and boardroom tables, which opens and closes manually and is entirely concealed below the work surface when closed. To open the unit, one has simply to depress one side of the top panel and the unit rolls over 180 degrees and stops against a concealed built-in stop block. To close the unit, one only has to depress the lock button and push on the same side and the unit will roll back to its closed position, coming to rest against the concealed stop block.
The design is such that the table work surface may be cut out in a rectangular aperture and the cutout panel used for the top cover on the interface. This cutout feature will work on a wide variety of tabletop thicknesses, without affecting the geometry of the rotating interface station base. The interface receptacles are mounted on both sloped “roof top” panels, allowing access from both sides of the table.
A lock bolt mechanism is provided internally in the station base to secure the unit in the open and closed positions. The unit is easily rotated 180 degrees from its open to its closed position. Wiring is fed into the station base through the center of torus hinges at each end of the outlet box. Plastic strain relief connectors, which pass through the torus hinges, are used to secure the wiring from being pulled out of the receptacles and insure that the wires rotate with the station. The torus hinges are fastened to the station base, which is screwed to the bottom of the work surface cutout panel, in a manner to align the station top panel into the work surface cutout aperture.
OBJECTS OF THE INVENTION
It is an object of the invention to provide an electrical grommet to supply electric, phone and data lines into conference and boardroom tables.
Another object of the invention is to provide a method of supplying electric, phone and data lines into conference and boardroom tables, which opens and closes manually and is entirely concealed below the work surface when closed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the power and data station of this invention in the open position;
FIG. 2 is a perspective view of the power and data station in the closed position;
FIG. 3A is a section view in the open locked position;
FIG. 3B is a detailed view of the lock button;
FIG. 3C is a detailed view of the unit locked;
FIG. 4A is a section view in the open unlocked position;
FIG. 4B is a detail view of the lock button depressed to unlock;
FIG. 4C is a detail view of the unit unlocked
FIG. 5 is a section view of the unit rotated 90 degrees;
FIG. 6A is a section view of the unit closed;
FIG. 6B is detail view of the unit semi-locked closed;
FIG. 7A is an elevational view showing the hinge and station in the open position;
FIG. 7B is a detail of the hinge;
FIG. 8A is an elevational view showing the hinge and station in the closed position;
FIG. 8B is a detail view of the hinge; and,
FIG. 9 is an exploded view of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1-9 , there is shown power and data station 10 set into the tabletop of a work surface, such as a conference or boardroom table 12 . Station 10 is in the open position, exposing a plurality of power receptacles 14 and 15 and data ports 16 and 17 . Power receptacles 14 , 15 are located in panels 18 and 20 and data ports 16 , 17 are located in panels 18 and 20 of station 10 . Panels 18 and 20 are both sloped, set at an angle to the horizontal, which makes power receptacles 14 , 15 and data ports 16 , 17 easier to use and easier to access.
FIG. 2 shows station 10 rotated 180 degrees to its closed position in table 12 . Panel 22 of table 12 , was cut out from the work surface to form the cavity for placement of station 10 , or is a separate panel made to fit the cut-out area and match its color and texture, if desired. Station 10 is affixed to one side of panel 22 , so that when station 10 is rotated 180 degrees, panel 22 fits flush with, and completely fills the opening in table 12 .
Referring to FIGS. 3A , 3 B, and 3 C, there is shown a cross-section of station 10 in the locked-open mode. The base or body of station 10 comprises vertical panels 11 and 11 ′ to which are attached sloped panels 18 and 20 and end plates 68 and 70 . Vertical panels 11 and 11 ′ are fixedly attached to table piece 22 , making the entire station 10 fixedly attached to table piece 22 . Station 10 , affixed to table piece 22 , stays fixed together, even during rotation of station 10 , providing a stable support for the electrical and data connections.
A lock bolt 24 locks station 10 in the open position. Lock bolt 24 is held in position by lower lock bolt guides 25 and 25 ′ and upper lock bolt guides 40 and 40 ′. Lock button 26 is slidably attached to lock bolt 24 and fits through slot 29 in ridge panel 27 . In the hinge locked position, lock bolt tooth 30 fits into lock strike slot 31 of torus hinge 32 . When lock button 26 is depressed, lock bolt tooth 30 moves downward into space 34 , out of lock strike 31 , releasing station 10 , allowing it to rotate 180 degrees on torus hinges 32 and 32 ′. When pressure is released on lock button 26 , spring 28 urges lock button 26 to its upward position, shown in FIGS. 3A and 3B .
Two flexible seal wing members 36 and 38 act as loose fitting seals to prevent foreign objects from falling into the gap between station 10 and the table top aperture when the unit is open.
Wiring is fed to an outlet from the power and data panels 18 and 20 through center holes 35 , 37 of torus hinges 32 , 32 ′ at each end of the base outlet box. Plastic strain relief connectors, which pass through the torus hinges, may be used to secure the wiring from being pulled out of the receptacles and insure that the wires rotate with the outlet box. Torus hinges 32 , 32 ′ are fastened to end panels 68 , 70 , which attach to vertical panels 11 , 11 ′ and panels 18 , 20 .
Referring to FIGS. 4A , 4 B, and 4 C, there is shown the hinge unlocked position in which lock bolt tooth 30 is pushed out of lock strike slot 31 by depression of lock button 26 , which moves lock bolt 24 downward.
Referring to FIGS. 5 , 6 A and 6 B, there is shown station 10 as it is rotating 90 degrees clockwise ( FIG. 5 ) from its open position to 180 degrees rotation ( FIG. 6A ) to its closed position. The rotation is accomplished by pushing down on lock button 26 , moving lock bolt tooth 30 out of lock strike slot 31 and by then pushing down on side 20 .
Lock strike 50 is more shallow than lock strike 31 and is also curved, concave, so that station 10 can be returned to the open position by simply pushing panel 22 , rotating station 10 countercloskwise, back to the open position. Lock bolt tooth 30 rides up and out of lock strike 50 , which is shallow and has a curved surface, with a small amount of pressure applied. This is done since it not possible to depress lock button 26 when the station is in its closed position.
Referring to FIGS. 7A , 7 B, 8 A and 8 B, there is shown an end view of torus hinge 32 which has stop block 52 affixed thereto. When station 10 is rotated 180 degrees to both the open and closed position, stop block 52 impacts either adjustable stop screw 54 or 56 , which stops the rotation of station 10 in the proper level, horizontal position. Screws 58 and 60 attach stop block 52 to end plate 70 .
Referring now to FIG. 9 , there is shown an exploded view of station 10 . Clips 64 and 66 hold torus hinges 32 and 32 ′ in place in end plates 68 and 70 . End plates 68 , 70 have center holes 110 and 111 , which line up with center holes 35 and 37 of torus hnges 32 , 32 ′ and with center hole 39 of lock bolt 24 . Cans 60 and 62 , which attach underneath panels 18 and 20 , hold the power and data components.
The components of the station are preferably made of metal, such as aluminum or steel.
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A power and data station rotatably mounted in an opening in a work surface comprising, a base having sloped power and data receptacle panels, a pair of torus hinges rotatably attached to said base, a lock bolt having a lock tooth fixedly attached to said base, a lock button slidably attached to said lock bolt, a first lock strike slot in one of said torus hinges, said lock tooth adapted to engage said lock strike slot to hold said station in an open position.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/589,594, filed Feb. 23, 2012, the disclosure of which is hereby incorporated herein in its entirety by this reference.
BACKGROUND OF THE INVENTION
The gene encoding AAD-12 (aryloxyalkanoate dioxygenase-12) is capable of imparting commercial levels of tolerance to the phenoxyacetic acid herbicides, 2,4-D and MCPA, and the pyridyloxyacetic acid herbicides, triclopyr and fluroxypyr, when expressed in transgenic plants. The gene encoding PAT (phosphinothricin acetyltransferase) is capable of imparting tolerance to the herbicide phoshpinothricin (glufosinate) when expressed in transgenic plants. PAT has been successfully expressed in cotton for use both as a selectable marker, and to impart commercial levels of tolerance to the herbicide glufosinate in transgenic plants.
The expression of transgenes in plants is known to be influenced by their location in the plant genome, perhaps due to chromatin structure (e.g., heterochromatin) or the proximity of transcriptional regulatory elements (e.g., enhancers) close to the integration site (Weising et al., Ann. Rev. Genet 22:421-477, 1988). The presence of the transgene at different locations in the genome will influence the overall phenotype of the plant in different ways. For example, it has been observed in plants and in other organisms that there may be a wide variation in levels of expression of an introduced gene among events. There may also be differences in spatial or temporal patterns of expression, for example, differences in the relative expression of a transgene in various plant tissues, that may not correspond to the patterns expected from transcriptional regulatory elements present in the introduced gene construct. For this reason, it is common to produce hundreds to thousands of different events and screen those events for a single event that has desired transgene expression levels and patterns for commercial purposes. As such, it is often necessary to screen a large number of events in order to identify an event characterized by optimal expression of an introduced gene of interest. An event that has desired levels or patterns of transgene expression is useful for introgressing the transgene into other genetic backgrounds by sexual outcrossing using conventional breeding methods. Progeny of such crosses maintain the transgene expression characteristics of the original transformant. This strategy is used to ensure reliable gene expression in a number of varieties that are well adapted to local growing conditions.
It is desirable to be able to detect the presence of a particular event in order to determine whether progeny of a sexual cross contain a transgene or group of transgenes of interest. In addition, a method for detecting a particular event would be helpful for complying with regulations requiring the pre-market approval and labeling of food and fiber derived from recombinant crop plants, for example, or for use in environmental monitoring, monitoring traits in crops in the field, or monitoring products derived from a crop harvest, as well as for use in ensuring compliance of parties subject to regulatory or contractual terms.
It is possible to detect the presence of a transgenic event by any nucleic acid detection method known in the art including, but not limited to, the polymerase chain reaction (PCR) or DNA hybridization using nucleic acid probes. These detection methods generally focus on frequently used genetic elements, such as promoters, terminators, marker genes, etc., because for many DNA constructs, the coding region is interchangeable. As a result, such methods may not be useful for discriminating between different events, particularly those produced using the same DNA construct or very similar constructs unless the DNA sequence of the flanking DNA adjacent to the inserted heterologous DNA is known. For example, an event-specific PCR assay is described in United States Patent Application 2006/0070139 for maize event DAS-59122-7. It would be desirable to have a simple and discriminative method for the identification of cotton event pDAB4468.19.10.3.
BRIEF SUMMARY OF THE INVENTION
Embodiments of the present invention relate to a method for detecting a new insect resistant and herbicide tolerant transgenic cotton transformation event, designated as cotton event pDAB4468.19.10.3, comprising aad-12 and pat as described herein, inserted into a specific site within the genome of a cotton cell. Representative cotton seed has been deposited with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va., 20110. The deposit, designated as ATCC Deposit No. PTA-12457, was made on behalf of Dow AgroSciences LLC on Jan. 23, 2012. This deposit was made and will be maintained in accordance with and under the terms of the Budapest Treaty with respect to seed deposits for the purposes of patent procedure.
The DNA of cotton plants containing this event includes the junction/flanking sequences described herein that characterize the location of the inserted DNA within the cotton genome. SEQ ID NO:1 and SEQ ID NO:2 are diagnostic for cotton event pDAB4468.19.10.3. More particularly, sequences surrounding the junctions at by 1354/1355 of SEQ ID NO:1, and by 168/169 of SEQ ID NO:2 are diagnostic for cotton event pDAB4468.19.10.3. Paragraphs [0012] and [0013] below describe examples of sequences comprising these junctions that are characteristic of DNA of cotton plants containing cotton event pDAB4468.19.10.3.
In another embodiment, the invention provides a method of detecting cotton event pDAB4468.19.10.3 in a sample comprising cotton DNA, said method comprising:
(a) contacting said sample with a first primer at least 10 bp in length that selectively binds to a flanking sequence within by 1-1354 of SEQ ID NO:1 or the complement thereof, and a second primer at least 10 bp in length that selectively binds to an insert sequence within by 1355-1672 of SEQ ID NO:1 or the complement thereof; and (b) assaying for an amplicon generated between said primers; or, (c) contacting said sample with a first primer at least 10 bp in length that selectively binds to an insert sequence within by 1-168 of SEQ ID NO:2 or the complement thereof, and a second primer at least 10 bp in length that selectively binds to a flanking sequence within by 169-2898 of SEQ ID NO:2 or the complement thereof; and (d) assaying for an amplicon generated between said primers.
In another embodiment, the invention provides a method of detecting cotton event pDAB4468.19.10.3 comprising:
(a) contacting said sample with a first primer that selectively binds to a flanking sequence selected from the group consisting of by 1-1354 of SEQ ID NO:1 and by 169-2898 of SEQ ID NO:2, and complements thereof; and a second primer that selectively binds to SEQ ID NO:14, or the complement thereof; (b) subjecting said sample to polymerase chain reaction; and (c) assaying for an amplicon generated between said primers.
In another embodiment, the invention provides an isolated DNA molecule that is diagnostic for cotton event pDAB4468.19.10.3. Such molecules include, in addition to SEQ ID NOS: 1 and 2, molecules of at least 50 bp in length which comprise a polynucleotide sequence which spans the by 1354/1355 junction of SEQ ID NO:1, and molecules of at least 50 bp in length which comprise a polynucleotide sequence which spans the by 168/169 junction of SEQ ID NO:2. Examples are by 1329-1380 of SEQ ID NO:1; by 1304-1405 of SEQ ID NO:1; by 1254-1455 of SEQ ID NO:1; by 1154-1555 of SEQ ID NO:1; by 1054-1655 of SEQ ID NO:1; by 143-194 of SEQ ID NO:2; by 118-219 of SEQ ID NO:2; by 68-269 of SEQ ID NO:2; and by 1-369 of SEQ ID NO:2, and complements thereof.
Additionally, embodiments of the invention provide assays for detecting the presence of the subject event in a sample (of cotton, for example). The assays can be based on the DNA sequence of the recombinant construct, inserted into the cotton genome, and on the genomic sequences flanking the insertion site. Kits and conditions useful in conducting the assays are also provided.
Embodiments of the invention relate in part to the cloning and analysis of the DNA sequences of the border regions resulting from insertion of T-DNA from pDAB4468 in transgenic cotton lines. These sequences are unique. Based on the insert and junction sequences, event-specific primers can be and were generated. PCR analysis demonstrated that these events can be identified by analysis of the PCR amplicons generated with these event-specific primer sets. Thus, these and other related procedures can be used to uniquely identify cotton lines comprising the event of the subject disclosure.
BRIEF DESCRIPTION OF THE SEQUENCES
SEQ ID NO:1 is the 5′ DNA flanking border sequence for cotton event pDAB4468.19.10.3. Nucleotides 1-1354 are genomic sequence. Nucleotides 1355-1672 are insert sequence.
SEQ ID NO:2 is the 3′ DNA flanking border sequence for cotton event pDAB4468.19.10.3. Nucleotides 1-168 are insert sequence. Nucleotides 169-2898 are genomic sequence.
SEQ ID NO:3 is a 77 bp DNA fragment that is diagnostic of the 5′ integration junction of cotton event pDAB4468.19.10.3.
SEQ ID NO:4 is a 90 bp DNA fragment that is diagnostic of the 3′ integration junction of cotton event pDAB4468.19.10.3.
SEQ ID NO:5 is oligonucleotide primer, ES_1910_5_F, which was used for the TaqMan® assay to detect the 5′ border of cotton event 9582.814.19.1.
SEQ ID NO:6 is oligonucleotide primer, ES_1910_5_R, which was used for the TaqMan® assay to detect the 5′ border of cotton event 9582.814.19.1.
SEQ ID NO:7 is oligonucleotide probe, ES_1910_5Pr, which was used for the TaqMan® assay to detect the 5′ border of cotton event 9582.814.19.1. This probe had a VIC fluorescent moiety added to the 5′ end and an MGB quencher added to the 3′ end.
SEQ ID NO:8 is oligonucleotide primer, ES_1910_3_F, which was used for the TaqMan® assay to detect the 3′ border of cotton event 9582.814.19.1.
SEQ ID NO:9 is oligonucleotide primer, ES_1910_3_R, which was used for the TaqMan® assay to detect the 3′ border of cotton event 9582.814.19.1.
SEQ ID NO:10 is oligonucleotide probe, ES_1910_3Pr, which was used for the TaqMan® assay to detect the 5′ border of cotton event 9582.814.19.1. This probe had a VIC fluorescent moiety added to the 5′ end and an MGB quencher added to the 3′ end.
SEQ ID NO:11 is oligonucleotide primer, IC_Sah7F, which was used for the TaqMan® assay to detect the endogenous reference gene, Sah7 (GenBank: AY117065.1).
SEQ ID NO:12 is oligonucleotide primer, IC_Sah7R, which was used for the TaqMan® assay to detect the endogenous reference gene, Sah7 (GenBank: AY117065.1).
SEQ ID NO:13 is oligonucleotide probe, IC_Sah7_Pr, which was used for the TaqMan® assay to detect the endogenous reference gene, Sah7 (GenBank: AY117065.1). This probe had a Cy5fluorescent moiety added to the 5′ end and a BHQ2 quencher added to the 3′ end.
SEQ ID NO:14 is the T-strand DNA sequence of pDAB4468.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a plasmid map of pDAB4468 containing the aad-12 and pat expression cassette.
FIG. 2 depicts the primer and probe locations for the TaqMan® assay of the cotton event pDAB4468.19.10.3.
DETAILED DESCRIPTION OF THE INVENTION
Both ends of cotton event pDAB4468.19.10.3 insertion have been sequenced and characterized. Event specific assays were developed. The event has also been mapped onto the cotton genome (chromosome 3 of the A sub-genome). The event can be introgressed into further elite lines.
As alluded to above in the Background section, the introduction and integration of a transgene into a plant genome involves some random events (hence the name “event” for a given insertion that is expressed). That is, with many transformation techniques such as Agrobacterium transformation, the biolistic transformation (i.e., gene gun), and silicon carbide mediated transformation (i.e., WHISKERS), it is unpredictable where in the genome a transgene will become inserted. Thus, identifying the flanking plant genomic DNA on both sides of the insert can be important for identifying a plant that has a given insertion event. For example, PCR primers can be designed that generate a PCR amplicon across the junction region of the insert and the host genome. This PCR amplicon can be used to identify a unique or distinct type of insertion event.
Definitions and examples are provided herein to help describe the embodiments of the present invention and to guide those of ordinary skill in the art to practice those embodiments. Unless otherwise noted, terms are to be understood according to conventional usage by those of ordinary skill in the relevant art. The nomenclature for DNA bases as set forth at 37 CFR §1.822 is used.
As used herein, the term “progeny” denotes the offspring of any generation of a parent plant which comprises cotton event pDAB4468.19.10.3.
A transgenic “event” is produced by transformation of plant cells with heterologous DNA, i.e., a nucleic acid construct that includes the transgenes of interest, regeneration of a population of plants resulting from the insertion of the transgene into the genome of the plant, and selection of a particular plant characterized by insertion into a particular genome location. The term “event” refers to the original transformant and progeny of the transformant that include the heterologous DNA. The term “event” also refers to progeny produced by a sexual outcross between the transformant and another variety that includes the genomic/transgene DNA. Even after repeated back-crossing to a recurrent parent, the inserted transgene DNA and flanking genomic DNA (genomic/transgene DNA) from the transformed parent is present in the progeny of the cross at the same chromosomal location. The term “event” also refers to DNA from the original transformant and progeny thereof comprising the inserted DNA and flanking genomic sequence immediately adjacent to the inserted DNA, which would be expected to be transferred to a progeny that receives inserted DNA including the transgene of interest as the result of a sexual cross of one parental line that includes the inserted DNA (e.g., the original transformant and progeny resulting from selfing) and a parental line that does not contain the inserted DNA.
A “junction sequence” or “border sequence” spans the point at which DNA inserted into the genome is linked to DNA from the cotton native genome flanking the insertion point, the identification or detection of one or the other junction sequences in a plant's genetic material being sufficient to be diagnostic for the event. Included are the DNA sequences that span the insertions in herein-described cotton events and similar lengths of flanking DNA. Specific examples of such diagnostic sequences are provided herein; however, other sequences that overlap the junctions of the insertions, or the junctions of the insertions and the genomic sequence, are also diagnostic and could be used in accordance with embodiments of the invention of the subject disclosure.
Embodiments of the invention relate in part to event identification using such flanking, junction, and insert sequences. Related PCR primers and amplicons are included in embodiments of the invention. In accordance with embodiments of the subject invention, PCR analysis methods using amplicons that span across inserted DNA and its borders can be used to detect or identify commercialized transgenic cotton varieties or lines derived from the subject proprietary transgenic cotton lines.
The flanking/junction sequences are diagnostic for cotton event pDAB4468.19.10.3. Based on these sequences, event-specific primers were generated. PCR analysis demonstrated that these cotton lines can be identified in different cotton genotypes by analysis of the PCR amplicons generated with these event-specific primer sets. Thus, these and other related procedures can be used to uniquely identify these cotton lines. The sequences identified herein are unique.
Detection techniques of embodiments of the subject invention are especially useful in conjunction with plant breeding, to determine which progeny plants comprise a given event, after a parent plant comprising an event of interest is crossed with another plant line in an effort to impart one or more additional traits of interest in the progeny. These PCR analysis methods benefit cotton breeding programs as well as quality control, especially for commercialized transgenic cotton seeds. PCR detection kits for these transgenic cotton lines can also now be made and used. This is also beneficial for product registration and product stewardship.
Furthermore, flanking cotton/genomic sequences can be used to specifically identify the genomic location of each insert. This information can be used to make molecular marker systems specific to each event. These can be used for accelerated breeding strategies and to establish linkage data.
Still further, the flanking sequence information can be used to study and characterize transgene integration processes, genomic integration site characteristics, event sorting, stability of transgenes and their flanking sequences, and gene expression (especially related to gene silencing, transgene methylation patterns, position effects, and potential expression-related elements such as MARS [matrix attachment regions], and the like).
In light of all the subject disclosure, it should be clear that embodiments of the subject invention include seeds available under the ATCC Deposit No. identified in paragraph [0005]. Embodiments of the invention also include a herbicide-tolerant cotton plant grown from a seed deposited with the ATCC Deposit No. identified in paragraph [0005]. Embodiments of the invention also include parts of said plant, such as leaves, tissue samples, seeds produced by said plant, pollen, and the like (wherein these parts of the plant comprise aad-12, and pat, and SEQ ID NOS: 1 and 2).
As used herein, the term “cotton” means Gossypium hirsutum and includes all varieties thereof that can be bred with a cotton plant.
The DNA molecules of embodiments of the invention can be used as molecular markers in a marker assisted breeding (MAB) method. DNA molecules of embodiments of the invention can be used in methods (such as, AFLP markers, RFLP markers, RAPD markers, SNPs, and SSRs) that identify genetically linked agronomically useful traits, as is known in the art. The herbicide-tolerance traits can be tracked in the progeny of a cross with a cotton plant of embodiments of the subject invention (or progeny thereof and any other cotton cultivar or variety) using the MAB methods. The DNA molecules are markers for this trait, and MAB methods that are well known in the art can be used to track the hebicide-tolerant trait(s) in cotton plants where at least one cotton line of embodiments of the subject invention, or progeny thereof, was a parent or ancestor. The methods of embodiments of the invention can be used to identify any cotton variety having the subject event.
As used herein, a “line” is a group of plants that display little or no genetic variation between individuals for at least one trait. Such lines may be created by several generations of self-pollination and selection, or vegetative propagation from a single parent using tissue or cell culture techniques.
As used herein, the terms “cultivar” and “variety” are synonymous and refer to a line which is used for commercial production.
“Stability” or “stable” means that with respect to the given component, the component is maintained from generation to generation and, preferably, at least three generations.
“Commercial Utility” is defined as having good plant vigor and high fertility, such that the crop can be produced by farmers using conventional farming equipment, and the oil with the described components can be extracted from the seed using conventional crushing and extraction equipment.
“Agronomically elite” means that a line has desirable agronomic characteristics such as yield, maturity, disease resistance, and the like, in addition to the herbicide tolerance due to the subject event(s). Any and all of these agronomic characteristics and data points can be used to identify such plants, either as a point or at either end or both ends of a range of characteristics used to define such plants.
As one skilled in the art will recognize in light of this disclosure, preferred embodiments of detection kits, for example, can include probes and/or primers directed to and/or comprising “junction sequences” or “transition sequences” (where the cotton genomic flanking sequence meets the insert sequence). For example, this includes a polynucleotide probes, primers, and/or amplicons designed to identify one or both junction sequences (where the insert meets the flanking sequence). One common design is to have one primer that hybridizes in the flanking region, and one primer that hybridizes in the insert. Such primers are often each about at least ˜15 residues in length. With this arrangement, the primers can be used to generate/amplify a detectable amplicon that indicates the presence of an event of an embodiment of the subject invention. These primers can be used to generate an amplicon that spans (and includes) a junction sequence as indicated above.
The primer(s) “touching down” in the flanking sequence is typically not designed to hybridize beyond about 1200 bases or so beyond the junction. Thus, typical flanking primers would be designed to comprise at least 15 residues of either strand within 1200 bases into the flanking sequences from the beginning of the insert. That is, primers comprising a sequence of an appropriate size from (or hybridizing to) base pairs 154-1672 of SEQ ID NO:1 and/or base pairs 1-1369 of SEQ ID NO:2 are within the scope of embodiments of the subject invention. Insert primers can likewise be designed anywhere on the insert, but base pairs 1-6387 of SEQ ID NO:14, can be used, for example, non-exclusively for such primer design.
One skilled in the art will also recognize that primers and probes can be designed to hybridize, under a range of standard hybridization and/or PCR conditions wherein the primer or probe is not perfectly complementary to the exemplified sequence. That is, some degree of mismatch or degeneracy can be tolerated. For an approximately 20 nucleotide primer, for example, typically one or two or so nucleotides do not need to bind with the opposite strand if the mismatched base is internal or on the end of the primer that is opposite the amplicon. Various appropriate hybridization conditions are provided below. Synthetic nucleotide analogs, such as inosine, can also be used in probes. Peptide nucleic acid (PNA) probes, as well as DNA and RNA probes, can also be used. What is important is that such probes and primers are diagnostic for (able to uniquely identify and distinguish) the presence of an event of an embodiment of the subject invention.
It should be noted that errors in PCR amplification can occur which might result in minor sequencing errors, for example. That is, unless otherwise indicated, the sequences listed herein were determined by generating long amplicons from cotton genomic DNAs, and then cloning and sequencing the amplicons. It is not unusual to find slight differences and minor discrepancies in sequences generated and determined in this manner, given the many rounds of amplification that are necessary to generate enough amplicon for sequencing from genomic DNAs. One skilled in the art should recognize and be put on notice that any adjustments needed due to these types of common sequencing errors or discrepancies are within the scope of embodiments of the subject invention.
It should also be noted that it is not uncommon for some genomic sequence to be deleted, for example, when a sequence is inserted during the creation of an event. Thus, some differences can also appear between the subject flanking sequences and genomic sequences listed in GENBANK, for example.
Components of the DNA sequence “insert” are illustrated in the Figures and are discussed in more detail below in the Examples. The DNA polynucleotide sequences of these components, or fragments thereof, can be used as DNA primers or probes in the methods of embodiments of the invention.
In some embodiments of the invention, compositions and methods are provided for detecting the presence of the transgene/genomic insertion region, in plants and seeds and the like, from a cotton plant. DNA sequences are provided that comprise the subject 5′ transgene/genomic insertion region junction sequence provided herein (between base pairs 1354/1355 of SEQ ID NO:1), segments thereof, and complements of the exemplified sequences and any segments thereof. DNA sequences are provided that comprise the subject 3′ transgene/genomic insertion region junction sequence provided herein (between base pairs 168/169 of SEQ ID NO:2), segments thereof, and complements of the exemplified sequences and any segments thereof. The insertion region junction sequence spans the junction between heterologous DNA inserted into the genome and the DNA from the cotton cell flanking the insertion site. Such sequences can be diagnostic for the given event.
Based on these insert and border sequences, event-specific primers can be generated. PCR analysis demonstrated that cotton lines of embodiments of the subject invention can be identified in different cotton genotypes by analysis of the PCR amplicons generated with these event-specific primer sets. These and other related procedures can be used to uniquely identify these cotton lines. Thus, PCR amplicons derived from such primer pairs are unique and can be used to identify these cotton lines.
In some embodiments, DNA sequences that comprise a contiguous fragment of the novel transgene/genomic insertion region are an aspect of embodiments of this invention. Included are DNA sequences that comprise a sufficient length of polynucleotides of transgene insert sequence and a sufficient length of polynucleotides of cotton genomic sequence from one or more of the three aforementioned cotton plants and/or sequences that are useful as primer sequences for the production of an amplicon product diagnostic for one or more of these cotton plants.
Related embodiments pertain to DNA sequences that comprise at least 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or more contiguous nucleotides of a transgene portion of a DNA sequence identified herein (such as SEQ ID NO:1 and segments thereof), or complements thereof, and a similar length of flanking cotton DNA sequence from these sequences, or complements thereof. Such sequences are useful as DNA primers in DNA amplification methods. The amplicons produced using these primers are diagnostic for any of the cotton events referred to herein. Therefore, embodiments of the invention also include the amplicons produced by such DNA primers.
Embodiments of this invention also include methods of detecting the presence of DNA, in a sample, that corresponds to the cotton event referred to herein. Such methods can comprise: (a) contacting the sample comprising DNA with a primer set that, when used in a nucleic acid amplification reaction with DNA from at least one of these cotton events, produces an amplicon that is diagnostic for said event(s); (b) performing a nucleic acid amplification reaction, thereby producing the amplicon; and (c) detecting the amplicon.
Further detection methods of embodiments of the subject invention include a method of detecting the presence of a DNA, in a sample, corresponding to said event, wherein said method comprises: (a) contacting the sample comprising DNA with a probe that hybridizes under stringent hybridization conditions with DNA from said cotton event and which does not hybridize under the stringent hybridization conditions with a control cotton plant (non-event-of-interest DNA); (b) subjecting the sample and probe to stringent hybridization conditions; and (c) detecting hybridization of the probe to the DNA.
DNA detection kits can be developed using the compositions disclosed herein and methods well known in the art of DNA detection. The kits are useful for identification of the subject cotton event DNA in a sample and can be applied to methods for breeding cotton plants containing this DNA. The kits contain DNA sequences complementary to the amplicons, for example, disclosed herein, or to DNA sequences complementary to DNA contained in the transgene genetic elements of the subject events. These DNA sequences can be used in DNA amplification reactions or as probes in a DNA hybridization method. The kits may also contain the reagents and materials necessary for the performance of the detection method.
A “probe” is an isolated nucleic acid molecule to which is attached a conventional detectable label or reporter molecule (such as a radioactive isotope, ligand, chemiluminescent agent, or enzyme). Such a probe can hybridize to a strand of a target nucleic acid, in the case of the embodiments of the invention, to a strand of genomic DNA from one of said cotton events, whether from a cotton plant or from a sample that includes DNA from the event. Probes in accordance with embodiments of the invention include not only deoxyribonucleic or ribonucleic acids but also polyamides and other probe materials that bind specifically to a target DNA sequence and can be used to detect the presence of that target DNA sequence.
“Primers” are isolated/synthesized nucleic acids that are annealed to a complementary target DNA strand by nucleic acid hybridization to form a hybrid between the primer and the target DNA strand, then extended along the target DNA strand by a polymerase, e.g., a DNA polymerase. Primer pairs of embodiments of the present invention refer to their use for amplification of a target nucleic acid sequence, e.g., by the polymerase chain reaction (PCR) or other conventional nucleic-acid amplification methods.
Probes and primers are generally 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378, 379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, 398, 399, 400, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419, 420, 421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434, 435, 436, 437, 438, 439, 440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 460, 461, 462, 463, 464, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476, 477, 478, 479, 480, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499, 500, or 1000, or 2000, or 5000 polynucleotides or more in length. Such probes and primers hybridize specifically to a target sequence under stringent hybridization conditions. Preferably, probes and primers in accordance with embodiments of the present invention have complete sequence similarity with the target sequence, although probes differing from the target sequence and that retain the ability to hybridize to target sequences may be designed by conventional methods.
Methods for preparing and using probes and primers are described, for example, in Molecular Cloning: A Laboratory Manual, 2nd ed., vol. 1-3, ed. Sambrook et al., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989. PCR-primer pairs can be derived from a known sequence, for example, by using computer programs intended for that purpose.
Primers and probes based on the flanking DNA and insert sequences disclosed herein can be used to confirm (and, if necessary, to correct) the disclosed sequences by conventional methods, e.g., by re-cloning and sequencing such sequences.
The nucleic acid probes and primers of embodiments of the present invention hybridize under stringent conditions to a target DNA sequence. Any conventional nucleic acid hybridization or amplification method can be used to identify the presence of DNA from a transgenic event in a sample. Nucleic acid molecules or fragments thereof are capable of specifically hybridizing to other nucleic acid molecules under certain circumstances. As used herein, two nucleic acid molecules are said to be capable of specifically hybridizing to one another if the two molecules are capable of forming an anti-parallel, double-stranded nucleic acid structure. A nucleic acid molecule is said to be the “complement” of another nucleic acid molecule if they exhibit complete complementarity. As used herein, molecules are said to exhibit “complete complementarity” when every nucleotide of one of the molecules is complementary to a nucleotide of the other. Molecules that exhibit complete complementarity will generally hybridize to one another with sufficient stability to permit them to remain annealed to one another under conventional “high-stringency” conditions. Conventional high-stringency conditions are described by Sambrook et al., 1989.
Two molecules are said to exhibit “minimal complementarity” if they can hybridize to one another with sufficient stability to permit them to remain annealed to one another under at least conventional “low-stringency” conditions. Conventional low-stringency conditions are described by Sambrook et al., 1989. In order for a nucleic acid molecule to serve as a primer or probe it need only exhibit minimal complementary in sequence to be able to form a stable double-stranded structure under the particular solvent and salt concentrations employed.
The term “stringent condition” or “stringency conditions” is functionally defined with regard to the hybridization of a nucleic-acid probe to a target nucleic acid (i.e., to a particular nucleic-acid sequence of interest) by the specific hybridization procedure discussed in Sambrook et al., 1989, at 9.52-9.55. See also, Sambrook et al., 1989 at 9.47-9.52 and 9.56-9.58.
Depending on the application envisioned, one can use varying conditions of stringent conditions or polynucleotide sequence degeneracy of a probe or primer to achieve varying degrees of selectivity of hybridization towards the target sequence. For applications requiring high selectivity, one will typically employ relatively stringent conditions for hybridization of one polynucleotide sequence with a second polynuclotide sequence, e.g., one will select relatively low salt and/or high temperature conditions, such as provided by about 0.02 M to about 0.15 M NaCl at temperatures of about 50° C. to about 70° C. Stringent conditions, for example, could involve washing the hybridization filter at least twice with high-stringency wash buffer (0.2×SSC, 0.1% SDS, 65° C.). Appropriate stringency conditions which promote DNA hybridization, for example, 6.0× sodium chloride/sodium citrate (SSC) at about 45° C., followed by a wash of 2.0×SSC at 50° C. are known to those skilled in the art. For example, the salt concentration in the wash step can be selected from a low stringency of about 2.0×SSC at 50° C. to a high stringency of about 0.2×SSC at 50° C. In addition, the temperature in the wash step can be increased from low stringency conditions at room temperature, about 22° C., to high stringency conditions at about 65° C. Both temperature and salt may be varied, or either the temperature or the salt concentration may be held constant while the other variable is changed. Such selective conditions tolerate little, if any, mismatch between the probe and the template or target strand. Detection of DNA sequences via hybridization is well known to those of skill in the art, and the teachings of U.S. Pat. Nos. 4,965,188 and 5,176,995 are exemplary of the methods of hybridization analyses.
A nucleic acid of an embodiment of the present invention will specifically hybridize to one or more of the primers (or amplicons or other sequences) exemplified or suggested herein, including complements and fragments thereof, under high stringency conditions. In one aspect of the present invention, a marker nucleic acid molecule of an embodiment of the present invention has the nucleic acid sequence as set forth herein in one of the exemplified sequences, or complements and/or fragments thereof.
In another aspect of the present invention, a marker nucleic acid molecule of an embodiment of the present invention shares between 80% and 100% or 90% and 100% sequence identity with such nucleic acid sequences. In a further aspect of an embodiment of the present invention, a marker nucleic acid molecule of the present invention shares between 95% and 100% sequence identity with such sequence. Such sequences may be used as markers in plant breeding methods to identify the progeny of genetic crosses. The hybridization of the probe to the target DNA molecule can be detected by any number of methods known to those skilled in the art, these can include, but are not limited to, fluorescent tags, radioactive tags, antibody based tags, and chemiluminescent tags.
Regarding the amplification of a target nucleic acid sequence (e.g., by PCR) using a particular amplification primer pair, “stringent conditions” are conditions that permit the primer pair to hybridize only to the target nucleic-acid sequence to which a primer having the corresponding wild-type sequence (or its complement) would bind and preferably to produce a unique amplification product, the amplicon.
The term “specific for (a target sequence)” indicates that a probe or primer hybridizes under stringent hybridization conditions only to the target sequence in a sample comprising the target sequence.
As used herein, “amplified DNA” or “amplicon” refers to the product of nucleic-acid amplification of a target nucleic acid sequence that is part of a nucleic acid template. For example, to determine whether the cotton plant resulting from a sexual cross contains transgenic event genomic DNA from the cotton plant of an embodiment of the present invention, DNA extracted from a cotton plant tissue sample may be subjected to nucleic acid amplification method using a primer pair that includes a primer derived from flanking sequence in the genome of the plant adjacent to the insertion site of inserted heterologous DNA, and a second primer derived from the inserted heterologous DNA to produce an amplicon that is diagnostic for the presence of the event DNA. The amplicon is of a length and has a sequence that is also diagnostic for the event. The amplicon may range in length from the combined length of the primer pairs plus one nucleotide base pair, and/or the combined length of the primer pairs plus about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378, 379, 380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, 398, 399, 400, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419, 420, 421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434, 435, 436, 437, 438, 439, 440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 460, 461, 462, 463, 464, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476, 477, 478, 479, 480, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499, or 500, 750, 1000, 1250, 1500, 1750, 2000, or more nucleotide base pairs (plus or minus any of the increments listed above). Alternatively, a primer pair can be derived from flanking sequence on both sides of the inserted DNA so as to produce an amplicon that includes the entire insert nucleotide sequence. A member of a primer pair derived from the plant genomic sequence may be located a distance from the inserted DNA sequence. This distance can range from one nucleotide base pair up to about twenty thousand nucleotide base pairs. The use of the term “amplicon” specifically excludes primer dimers that may be formed in the DNA thermal amplification reaction.
Nucleic-acid amplification can be accomplished by any of the various nucleic-acid amplification methods known in the art, including the polymerase chain reaction (PCR). A variety of amplification methods are known in the art and are described, inter alia, in U.S. Pat. No. 4,683,195 and U.S. Pat. No. 4,683,202. PCR amplification methods have been developed to amplify up to 22 kb of genomic DNA. These methods as well as other methods known in the art of DNA amplification may be used in the practice of embodiments of the present invention. The sequence of the heterologous transgene DNA insert or flanking genomic sequence from a subject cotton event can be verified (and corrected if necessary) by amplifying such sequences from the event using primers derived from the sequences provided herein followed by standard DNA sequencing of the PCR amplicon or of the cloned DNA.
The amplicon produced by these methods may be detected by a plurality of techniques. Agarose gel electrophoresis and staining with ethidium bromide is a common well known method of detecting DNA amplicons. Another such method is Genetic Bit Analysis where a DNA oligonucleotide is designed which overlaps both the adjacent flanking genomic DNA sequence and the inserted DNA sequence. The oligonucleotide is immobilized in wells of a microwell plate. Following PCR of the region of interest (using one primer in the inserted sequence and one in the adjacent flanking genomic sequence), a single-stranded PCR product can be hybridized to the immobilized oligonucleotide and serve as a template for a single base extension reaction using a DNA polymerase and labeled ddNTPs specific for the expected next base. Analysis of a bound product can be completed via quantitating the amount of fluorescent signal. A fluorescent signal indicates presence of the insert/flanking sequence due to successful amplification, hybridization, and single base extension.
Another method is the Pyrosequencing technique as described by Winge (Innov. Pharma. Tech. 00:18-24, 2000). In this method an oligonucleotide is designed that overlaps the adjacent genomic DNA and insert DNA junction. The oligonucleotide is designed to hybridize to single-stranded PCR product from the region of interest (one primer in the inserted sequence and one in the flanking genomic sequence) and incubated in the presence of a DNA polymerase, ATP, sulfurylase, luciferase, apyrase, adenosine 5′ phosphosulfate and luciferin. DNTPs are added individually and the incorporation results in a light signal that is measured. A light signal indicates the presence of the transgene insert/flanking sequence due to successful amplification, hybridization, and single or multi-base extension.
Fluorescence Polarization is another method that can be used to detect an amplicon of an embodiment of the present invention. Following this method, an oligonucleotide is designed which overlaps the genomic flanking and inserted DNA junction. The oligonucleotide is hybridized to the single-stranded PCR product from the region of interest (one primer in the inserted DNA and one in the flanking genomic DNA sequence) and incubated in the presence of a DNA polymerase and a fluorescent-labeled ddNTP. Single base extension results in incorporation of the ddNTP. Incorporation of the fluorescently labeled ddNTP can be measured as a change in polarization using a fluorometer. A change in polarization indicates the presence of the transgene insert/flanking sequence due to successful amplification, hybridization, and single base extension.
TaqMan® (PE Applied Biosystems, Foster City, Calif.) is a method of detecting and quantifying the presence of a DNA sequence. Briefly, a FRET oligonucleotide probe is designed that overlaps the genomic flanking and insert DNA junction. The FRET probe and PCR primers (one primer in the insert DNA sequence and one in the flanking genomic sequence) are cycled in the presence of a thermostable polymerase and dNTPs. During specific amplification, the Taq DNA polymerase proofreading mechanism releases the fluorescent moiety away from the quenching moiety on the FRET probe. A fluorescent signal indicates the presence of the flanking/transgene insert sequence due to successful amplification and hybridization.
Molecular Beacons have been described for use in polynucleotide sequence detection. Briefly, a FRET oligonucleotide probe is designed that overlaps the flanking genomic and insert DNA junction. The unique structure of the FRET probe results in it containing secondary structure that keeps the fluorescent and quenching moieties in close proximity. The FRET probe and PCR primers (one primer in the insert DNA sequence and one in the flanking genomic sequence) are cycled in the presence of a thermostable polymerase and dNTPs. Following successful PCR amplification, hybridization of the FRET probe to the target sequence results in the removal of the probe secondary structure and spatial separation of the fluorescent and quenching moieties. A fluorescent signal results. A fluorescent signal indicates the presence of the flanking genomic/transgene insert sequence due to successful amplification and hybridization.
Having disclosed a location in the cotton genome that is excellent for an insertion, embodiments of the subject invention also comprise a cotton seed and/or a cotton plant comprising at least one non-cotton event pDAB4468.19.10.3 insert in the general vicinity of this genomic location. One option is to substitute a different insert in place of the one from cotton event pDAB4468.19.10.3 exemplified herein. In general, targeted homologous recombination, for example, is employed in particular embodiments. This type of technology is the subject of, for example, WO 03/080809 A2 and the corresponding published U.S. application (US 20030232410). Thus, embodiments of the subject invention include plants and plant cells comprising a heterologous insert (in place of or with multi-copies of the aad-12 or pat genes), flanked by all or a recognizable part of the flanking sequences identified herein (bp 1-1354 of SEQ ID NO:1 and by 169-2898 of SEQ ID NO:2). An additional copy (or additional copies) of an aad-12 or pat gene could also be targeted for insertion in this/these manner(s).
All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety to the extent they are not inconsistent with the explicit teachings of this specification.
The following examples are included to illustrate procedures for practicing embodiments of the invention and to demonstrate certain preferred embodiments of the invention. These examples should not be construed as limiting. It should be appreciated by those of skill in the art that the techniques disclosed in the following examples represent specific approaches used to illustrate preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in these specific embodiments while still obtaining like or similar results without departing from the spirit and scope of the invention. Unless otherwise indicated, all percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted.
The following abbreviations are used unless otherwise indicated.
by base pair
° C. degrees Celsius
DNA deoxyribonucleic acid
EDTA ethylenediaminetetraacetic acid
kb kilobase
μg microgram
μL microliter
mL milliliter
M molar mass
PCR polymerase chain reaction
PTU plant transcription unit or expression cassette
SDS sodium dodecyl sulfate
SSC a buffer solution containing a mixture of sodium chloride and sodium citrate, pH 7.0
TBE a buffer solution containing a mixture of Tris base, boric acid and EDTA, pH 8.3
EXAMPLES
Example 1
Event Specific TaqMan® Assay
Event specific TaqMan® assays were developed to detect the presence of cotton event pDAB4468.19.10.3 plants in breeding populations. Cotton event pDAB4468.19.10.3 contains the T-strand of the binary vector pDAB4468 ( FIG. 1 ). For specific detection of cotton event pDAB4468.19.10.3, two sets of TaqMan® primers and probes were designed according to the DNA sequences located in the 5′ (SEQ ID NO:1) or 3′ (SEQ ID NO:2) insert-to-plant junction ( FIG. 2 ). One of the event specific assays for cotton event pDAB4468.19.10.3 was designed to specifically detect a 77 bp DNA fragment (SEQ ID NO:3) that spans the 5′ integration junction using two primers and a target-specific MGB probe synthesized by Applied Biosystems (ABI) containing the VIC reporter at its 5′end. A second event specific assay for cotton event pDAB4468.19.10.3 was designed to specifically target an 90 bp DNA fragment (SEQ ID NO:4) that spans the 3′ integration junction using two specific primers and a target-specific MGB probe synthesized by ABI containing the VIC reporter at its 5′end. Specificity of this TaqMan® detection method for cotton event pDAB4468.19.10.3 was tested against other AAD12 and PAT cotton events and the non-transgenic cotton variety (Coker310). All assays were run in duplex format with a TaqMan® assay designed to detect the known single-copy cotton specific endogenous reference gene, Sah7 (GenBank: AY117065.1).
Example 1.1
gDNA Isolation
Genomic DNA was extracted using modified Qiagen Dneasy 96 plant DNA Kit™ (Qiagen, Valencia, Calif.). Fresh cotton leaf cotyledon discs, 6 per sample, were used for gDNA extraction. The gDNA was quantified with the Pico Green™ method according to vendor's instructions (Molecular Probes, Eugene, Oreg.). Samples were diluted by a ⅕ dilution with DNase-free water.
Example 1.2
TaqMan® Assay and Results
Specific TaqMan® primers and probes were designed for cotton event pDAB4468.19.10.3 specific TaqMan® assay. These reagents were used with the conditions listed below to detect the transgene insert within cotton event pDAB4468.19.10.3. Table 1 lists the primer and probe sequences that were developed specifically for the detection of cotton event pDAB4468.19.10.3.
TABLE 1
PCR Primers and Probes
5′ to 3′
Name
Description
sequence
Event Target Reaction
(SEQ ID NO: 5)
Event specific
GGCCTAACTTTTGGTGTG
ES_1910_5F
forward Primer
ATG
(SEQ ID NO: 6)
Event specific
AGGTGATTTCGATGATGA
ES_1910_5R
reverse Primer
TATATGTG
(SEQ ID NO: 7)
Event specific
VIC-TGCTGACTGGAAAT
ES_1910_5_Pr
probe used
ATACTTATGTA-MGB
with 5 and 6
(SEQ ID NO: 8)
Event specific
CATTAAAAACGTCCGCAA
ES_1910_3F
forward Primer
TGTG
(SEQ ID NO: 9)
Event specific
TGTTGGGTAAGACGGTTC
ES_1910_3R
reverse Primer
CA
(SEQ ID NO: 10)
Event specific
VIC-AAGCGTCAAAGAAA
ES_1910_3_Pr
probe used
AG-MGB
with 8 and 9
Reference System Reaction
(SEQ ID NO: 11)
Forward Primer
AGTTTGTAGGTTTTGATG
IC_Sah7F
TTACATTGAG
(SEQ ID NO: 12)
Reverse Primer
GCATCTTTGAACCGCCTA
IC_Sah7R
CTG
(SEQ ID NO: 13)
Probe
Cy5-AAACATAAAATAAT
IC_Sah7_Pr
GGGAACAACCATGACATG
T-BHQ2
The multiplex PCR conditions for amplification are as follows: 1× Roche PCR Buffer, 0.4 μM event specific forward primer, 0.4 μM event specific reverse primer, 0.4 μM Primer IC_Sah7F, 0.4 μM Primer IC_Sah7R, 0.2 μM Event specific probe, 0.2 μM IC_Sah7Pr Probe, 0.1% PVP, 2 μL of 1:5 diluted gDNA in a total reaction of 10 μl. The cocktail was amplified using the following conditions: i) 95° C. for 10 min., ii) 95° C. for 10 sec, iii) 55° C. for 30 sec, iv) repeat step ii-iii for 40 cycles, v) 40° C. hold. The Real time PCR was carried out on the Roche LightCycler® 480. Data analysis was based on measurement of the crossing point (Cp value) determined by LightCycler 480 software, which is the PCR cycle number when the rate of change in fluorescence reaches its maximum.
The TaqMan® detection method for cotton event pDAB4468.19.10.3 was tested against a different cotton event which contains the aad12 and pat PTUs and non-transgenic cotton variety in duplex format with cotton specific endogenous reference gene, IC Sah7 (GenBank: AY117065.1). The assays specifically detected the cotton event pDAB4468.19.10.3 and did not produce or amplify any false-positive results from the controls (i.e., the different cotton event and non-transgenic cotton variety Coker 310). The event specific primers and probes can be used for the detection of the cotton event pDAB4468.19.10.3 and these conditions and reagents are applicable for zygosity assays.
Having illustrated and described the principles of the present invention, it should be apparent to persons skilled in the art that the invention can be modified in arrangement and detail without departing from such principles. We claim all modifications that are within the spirit and scope of the appended claims.
All publications and published patent documents cited in this specification are incorporated herein by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
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Cotton event pDAB4468.19.10.3 comprises gene expression cassettes which contain genes encoding aad-12 and pat, affording herbicide tolerance to cotton crops containing the event, and enabling methods for crop protection. Embodiments of the subject invention provide polynucleotide-related event detection methods.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a discharge lamp lighting apparatus which can be preferably used as a light source for a projector apparatus.
[0003] 2. Description of Related Art
[0004] A projecting-type projector apparatus is required to project an image being uniform and having sufficient color rendering properties on a rectangular screen, and hence a short-arc type discharge lamp having a mercury vapor pressure of at least, for example, 150 atmospheres at the time of lighting is employed as a light source.
[0005] Therefore, recently, a projector apparatus having a dimming function capable of adjusting brightness of the screen according to the brightness of an usage environment or the type of the image to be projected has developed, and as a discharge lamp lighting apparatus used in such a projector apparatus, the one including a power supply apparatus configured to light a discharge lamp by switching the mode between a rated power lighting mode in which rated power is supplied to the discharge lamp and a low power lighting mode in which power lower than the rated power, for example, 80% of the rated power is supplied to the discharge lamp is known (see Japanese Patent No. 4274053 and corresponding U.S. Pat. No. 7,436,121).
[0006] However, in the discharge lamp lighting apparatus having such a structure, there is a problem that flicker may occur in the discharge lamp when switching from the rated power lighting mode to the low power lighting mode.
[0007] The reasons why the flicker occurs in the discharge lamp in the low power lighting mode when the mode is switched to the low power lighting mode in this manner seem to be as follows.
[0008] When the discharge lamp is lit by the rated power lighting mode, as illustrated in FIG. 14( a ), arcs A are formed between a pair of the electrodes 90 , 91 of the discharge lamp, and hence evaporated electrode substance is accumulated by a halogen cycle at positions where original points of the arcs A at distal ends of the electrodes 90 , 91 are positioned, so that projections p 1 according to the magnitude of the original points of the arcs A are formed.
[0009] Then, in a mode switching term in which the mode is switched from the rated power lighting mode to the low power lighting mode, as illustrated in FIG. 14( b ), the shape of the arcs A formed between the electrodes 90 , 91 becomes narrower as the value of power supplied to the discharge lamp is lowered, so that the evaporated electrode substance is accumulated at positions on surfaces of the projections p 1 of the respective electrodes 90 , 91 where the original points of the arcs A are positioned, whereby minute projections p 2 are formed on the surfaces of the projections p 1 of the respective electrodes 90 , 91 as illustrated in FIG. 14( c ).
[0010] Therefore, since the shape of the arcs A formed between the electrodes 90 , 91 is abruptly narrowed in the mode switching term in which the power supplied to the discharge lamp is lowered, the arcs A formed between the electrodes 90 , 91 become unstable by the movement of the original points on the surfaces of the projections p 1 of the respective electrodes 90 , 91 as illustrated by broken lines in FIG. 14( d ) and, consequently, a plurality of the minute projections p 2 are formed on the surfaces of the projections p 1 of the respective electrodes 90 , 91 as illustrated in FIG. 14( e ).
[0011] In this manner, in a case where the discharge lamp is lit in the low power lighting mode in a state in which a plurality of the minute projections p 2 are formed at the distal ends of the electrodes 90 , 91 , the original points of the arcs A move between the plurality of minute projections p 2 and, consequently, flicker occurs in the discharge lamp.
[0012] In the discharge lamp lighting apparatus of the related art having the light-dimming function, there is a problem that the distal ends of the respective electrodes are worn in the low power lighting mode, and hence the flicker occurs.
[0013] The reason why the wearing of the distal ends of the electrodes and the flicker occur in the discharge lamp in such a low power lighting mode seems to be as follows.
[0014] When the discharge lamp is lit, the electrode substance is evaporated from the electrodes by generation of high-temperature heat of the electrodes. However, the electrode substance evaporated by the halogen cycle accumulates on the surfaces of the electrodes. Then, when the discharge lamp is lit in the rated power lighting mode, evaporation of the electrode substance from the electrodes and accumulation of the evaporated electrode substance on the electrodes are balanced, so that wearing of the electrodes is suppressed.
[0015] Therefore, when the discharge lamp is it in the low power lighting mode, the amount of the evaporated electrode substance existing in the periphery of the electrodes is significantly reduced, and hence the accumulation of the electrode substance with respect to the electrodes is not sufficiently achieved. Therefore, evaporation of the electrode substance from the electrodes progresses, and consequently, the distal ends of the electrodes are worn, and hence the flicker occurs.
SUMMARY OF THE INVENTION
[0016] The present invention is based on the circumstances as described above, and it is an object of the present invention to provide a discharge lamp lighting apparatus which is capable of preventing or suppressing occurrence of flicker while the discharge lamp is lit in a second lighting mode in which AC power lower than rated power is supplied when the mode is switched from a first lighting mode in which AC power of the rated power is supplied to the second lighting mode.
[0017] Another object of the present invention is to provide a discharge lamp lighting apparatus which is capable of preventing or suppressing occurrence of wearing of electrodes of the discharge lamp and occurrence of flicker when the discharge lamp is lit in the a low power lighting mode in which AC power lower than the rated power of the discharge lamp is supplied.
Solution of the Problem
[0018] The discharge lamp lighting apparatus according to the present invention is a discharge lamp lighting apparatus including: a discharge lamp having a pair of electrodes formed of tungsten formed respectively with projections at distal ends thereof, and a power supply apparatus configured to supply AC power to the discharge lamp, wherein
[0019] the power supply apparatus has a function to light the discharge lamp by switching the mode between a first lighting mode in which rated power is supplied to the above-described discharge lamp and a second lighting mode in which power lower than the rated power is supplied to the discharge lamp, and is configured to control power to be supplied to the discharge lamp under the condition of an average power change ratio of 0.01 to 2.1 W/s in a mode switching term in which the mode is switched from the first lighting mode to the second lighting mode.
[0020] In the discharge lamp lighting apparatus described above, preferably, the power supply apparatus is configured to control the power to be supplied to the discharge lamp under the condition that the average power change ratio is equal to or lower than 2.1 W/s in the mode switching term in which the mode is switched from the second lighting mode to the first lighting mode. A configuration in which the power supply apparatus has a function to light the discharge lamp by switching the mode between the second lighting mode and a third lighting mode in which power lower than the supply power in the second lighting mode is supplied to the discharge lamp, and is configured to control the power to be supplied to the discharge lamp under the condition of an average power change ratio of 0.01 to 2.1 W/s in a mode switching term in which the mode is switched from the second lighting mode to the third lighting mode is also applicable.
[0021] In the discharge lamp lighting apparatus described above, the power supply apparatus is preferably configured to control the power to be supplied to the discharge lamp under the condition that the average power change ratio is equal to or lower than 2.1 W/s in the mode switching term in which the mode is switched from the third lighting mode to the second lighting mode.
[0022] Also, the discharge lamp lighting apparatus according to the present invention is a discharge lamp lighting apparatus including: a discharge lamp having a pair of electrodes formed respectively with projections at distal ends thereof; and a power supply apparatus configured to supply AC power to the discharge lamp, wherein
[0023] the power supply apparatus has a function to light the discharge lamp by switching the mode between a first lighting mode in which rated power is supplied to the above-described discharge lamp and a second lighting mode in which power lower than the rated power is supplied to the discharge lamp, and is configured to control the power to be supplied to the discharge lamp under the condition including the power change such that the power is lowered from a given power value P 1 equal to or lower than the supply power in the first lighting mode and equal to or higher than the supply power in the second lighting mode to a power value P 2 lower than the power value P 1 , and then is increased from the power value P 2 to a power value P 3 higher than the power value P 2 and lower than the power value P 1 in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode.
[0024] In the discharge lamp lighting apparatus described above, preferably, the power supply apparatus is configured to control the power to be supplied to the discharge lamp under the condition including twice or more power changes in which the power value is lowered from the power value P 1 to the power value P 2 lower than the power value P 1 , and then the power value is increased from the power value P 2 to the power value P 3 higher than the power value P 2 and lower than the power value P 1 in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode.
[0025] Also, the power supply apparatus may have a function to light the discharge lamp by switching the mode between the above-described second lighting mode and a third lighting mode in which power lower than the supply power in the second lighting mode is supplied to the discharge lamp, and be configured to control the power to be supplied to the discharge lamp under the condition including the power change such that the power value is lowered from a given power value P 1 equal to or lower than the supply power in the first lighting mode and equal to or higher than the supply power in the second lighting mode to the power value P 2 lower than the power value P 1 , and then is increased from the power value P 2 to a power value P 3 higher than the power value P 2 and lower than the power value P 1 in the mode switching term in which the mode is switched from the second lighting mode to the third lighting mode.
[0026] In the discharge lamp lighting apparatus described above, preferably, the power supply apparatus is configured to control the power to be supplied to the discharge lamp under the condition including twice or more power changes in which the power value is lowered from the power value P 1 to the power value P 2 lower than the power value P 1 , and then the power value is increased from the power value P 2 to the power value P 3 higher than the power value P 2 and lower than the power value P 1 in the mode switching term in which the mode is switched from the second lighting mode to the third lighting mode.
[0027] Also, the discharge lamp lighting apparatus according to the present invention is a discharge lamp lighting apparatus including: a discharge lamp; and a power supply apparatus configured to supply AC power to the discharge lamp, wherein the power supply apparatus has a function to light the discharge lamp by switching the mode between a rated power lighting mode in which rated power is supplied to the discharge lamp and a low power lighting mode in which power lower than the rated power is supplied to the discharge lamp, and is configured to supply basic AC power having a predetermined power value continuously to the discharge lamp, and supply superimposed power superimposed on this basic AC power cyclically, and simultaneously, controls the supply timing of the superimposed power, the power value of the superimposed power, or the supply time of the superimposed power according to a measured value of lighting voltage of the discharge lamp in the low power lighting mode.
[0028] In the discharge lamp lighting apparatus, preferably, the power supply apparatus is configured to control the supply timing of the superimposed power so as to supply the superimposed power to the discharge lamp at a shorter time interval when the measured value of the lighting voltage of the discharge lamp is higher than a predetermined reference value than when the measured value is lower than the predetermined reference value in the low power lighting mode.
[0029] Also, preferably, the power supply apparatus is configured to control the power value of the superimposed power so as to supply the superimposed power to the discharge lamp at a higher power value when the measured value of the lighting voltage of the discharge lamp is higher than the predetermined reference value than when the measured value is lower than the predetermined reference value in the low power lighting mode.
[0030] Also, preferably, the power supply apparatus is configured to control the supply time of the superimposed power so as to supply the superimposed power to the discharge lamp in a longer time when the measured value of the lighting voltage of the discharge lamp is higher than the predetermined reference value than when the measured value is lower than the predetermined reference value in the low power lighting mode.
[0031] The measured value of the lighting voltage of the discharge lamp may be measured either when the superimposed power is not supplied or when the superimposed power is supplied.
Advantageous Effects of Invention
[0032] According to a feature of the discharge lamp lighting apparatus of the invention, the power supply apparatus controls the power to be supplied to the discharge lamp under the condition in which the average power change ratio becomes 0.01 to 2.1 W/s in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, whereby the original points of the arcs do not move along the surfaces of the projections of the respective electrodes and the stable arcs are formed, so that a plurality of minute projections are not formed on the surfaces of the projections of the respective electrodes, and hence occurrence of flicker may be prevented or suppressed while the discharge lamp is lit in the second lighting mode when the mode is switched from the first lighting mode to the second lighting mode.
[0033] According to another a feature of the discharge lamp lighting apparatus of the invention, the power supply apparatus controls the power to be supplied to the discharge lamp under the condition that the average power change ratio is equal to or lower than 2.1 W/s in the mode switching term in which the mode is switched from the second lighting mode to the first lighting mode, so that occurrence of cracks in the light-emitting tube of the discharge lamp may be prevented of suppressed.
[0034] According to a further a feature of the discharge lamp lighting apparatus of the invention, since the AC power to be supplied to the discharge lamp is controlled under the condition including the power change in which the power value is lowered from the power value P 1 to the power value P 2 , then is increased from the power value P 2 to the power value P 3 higher than the power value P 2 and lower than the power value P 1 in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, even when a plurality of the minute projections are formed on the surfaces of the projections of the electrodes when the AC power to be supplied to the discharge lamp is lowered from the power value P 1 to the power value P 2 , a plurality of the minute projections are converged into one minute projection, whereby the electrodes are repaired when the AC power to be supplied to the discharge lamp is increased from the power value P 2 to the power value P 3 , so that the occurrence of flicker may be prevented or suppressed while the discharge lamp is lit in the second lighting mode.
[0035] According to yet another a feature of the discharge lamp lighting apparatus of the invention, the power supply apparatus supplies the superimposed power which is superimposed on the basic AC power of the predetermined power value cyclically to the discharge lamp, and controls the supply timing of the superimposed power, the power value of the superimposed power, or the supply time of the superimposed power in the low power lighting mode in which power lower than the rated power is supplied to the discharge lamp, so that the amount of the evaporated electrode substance existing in the periphery of the electrodes is increased, whereby accumulation of the evaporated electrode substance on the electrodes of the discharge lamp is accelerated, and hence occurrence of wearing of the electrodes of the discharge lamp and flicker may be prevented or suppressed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a cross-sectional view illustrating a configuration of an example of a discharge lamp used in a discharge lamp lighting apparatus of the present invention.
[0037] FIG. 2 is an explanatory drawing illustrating a configuration of an example of a circuit of a power supply apparatus used in a discharge lamp lighting apparatus according to a first embodiment.
[0038] FIG. 3 is a graph illustrating an example of a change of value of power supplied to the discharge lamp in a case where the mode is switched from a first lighting mode to a second lighting mode in the discharge lamp lighting apparatus according to the first embodiment.
[0039] FIG. 4 is an explanatory drawing illustrating an example of a current waveform of AC power to be supplied to the discharge lamp in the discharge lamp lighting apparatus according to the first embodiment.
[0040] FIGS. 5( a )- 5 ( c ) are explanatory views illustrating electrodes and a change of the shape of arcs of the discharge lamp in a mode switching term in which the mode is switched from the first lighting mode to the second lighting mode in the discharge lamp lighting apparatus according to the first embodiment.
[0041] FIG. 6 is a graph illustrating an example of a change of value of power supplied to the discharge lamp in the case where the mode is switched from the first lighting mode to the second lighting mode in a discharge lamp lighting apparatus according to a second embodiment.
[0042] FIGS. 7( a )- 7 ( f ) are explanatory views illustrating electrodes and a change of the shape of arcs of the discharge lamp in the mode switching term in which the mode is switched from the first lighting to the second lighting mode in the discharge lamp lighting apparatus according to the second embodiment.
[0043] FIG. 8 is a graph illustrating, along with a change of lighting voltage of the discharge lamp, a change of value of power supplied to the discharge lamp in the low power lighting mode in an example of the power supply apparatus in a discharge lamp lighting apparatus according to a third embodiment.
[0044] FIG. 9 is a graph illustrating, along with the change of lighting voltage of the discharge lamp, the change of value of power supplied to the discharge lamp in the low power lighting mode in another example of the power supply apparatus in the discharge lamp lighting apparatus according to the third embodiment.
[0045] FIG. 10 is a graph illustrating, along with the change of lighting voltage of the discharge lamp, the change of value of power supplied to the discharge lamp in the low power lighting mode in still another example of the power supply apparatus in the discharge lamp lighting apparatus according to the third embodiment.
[0046] FIG. 11 is a graph illustrating another example of the change of value of power supplied to the discharge lamp in the case where the mode is switched from the first lighting mode to the second lighting mode in the discharge lamp lighting apparatus according to the first embodiment.
[0047] FIG. 12 is a graph illustrating another example of the change of value of power supplied to the discharge lamp in the case where the mode is switched from the first lighting mode to the second lighting mode in the discharge lamp lighting apparatus according to the second embodiment.
[0048] FIG. 13 is a graph illustrating the change of value of power supplied to a discharge lamp in Experimental Example 1 in an example according to the second embodiment.
[0049] FIGS. 14( a )- 14 ( d ) are explanatory views illustrating electrodes and a change of the shape of arcs of the discharge lamp in the mode switching term in which the mode is switched from the first lighting to the second lighting mode in the discharge lamp lighting apparatus of the related art.
DETAILED DESCRIPTION OF THE INVENTION
[0050] Embodiments of a discharge lamp lighting apparatus of the present invention will be described below.
[0051] The discharge lamp lighting apparatus of the present invention is configured to be integrated, for example, in a projector apparatus having a dimming function, and includes a discharge lamp and a power supply apparatus configured to supply AC power to the discharge lamp.
[0052] FIG. 1 is an explanatory cross-sectional view illustrating a configuration of an example of the discharge lamp used in the discharge lamp lighting apparatus of the present invention.
[0053] A light-emitting tube 11 of this discharge lamp 10 includes a light-emitting portion 12 having an outline which defines a discharge space S in an interior thereof and has a substantially oval spherical shape, and sealed portions 13 extending continuously and integrally with both ends of the light-emitting portion 12 respectively and having a rod shape extending outward along a tube axis, and a pair of electrodes 14 , 15 formed respectively of tungsten arranged in the interior of the light-emitting portion 12 of the light-emitting tube 11 so as to face each other. Specifically, a pair of the electrodes 14 , 15 include rod-shaped shaft portions 14 b , 15 b extending along the direction toward the tube axis of the light-emitting tube 11 , substantially spherical head portions 14 a , 15 a formed continuously from respective distal ends of the shaft portions 14 b , 15 b and formed with projections p 1 at distal ends thereof, and coil portions 14 c , 15 c wound around rear end portions of the head portions 14 a , 15 a and distal end portions of the shaft portions 14 b , 15 b , and the respective head portions 14 a , 15 a thereof are arranged so as to face each other, and proximal portions of the respective shaft portions 14 b , 15 b are held by being embedded in the respective sealed portions 13 .
[0054] Metal foils 16 , 17 formed of molybdenum are hermetically embedded in interiors of the respective sealed portions 13 of the light-emitting tube 11 , and proximal ends of the shaft portions 14 b , 15 b of a pair of the electrodes 14 , 15 are respectively welded and electrically connected to one of ends of each of the metal foils 16 , 17 , and external leads 18 , 19 projecting outward from outer ends of the sealed portions 13 are welded and electrically connected to the other ends of the metal foils 16 , 17 .
[0055] The light-emitting tube 11 is formed of quartz glass, and for example, mercury, noble gas, and halogen are enclosed in the interior of the light-emitting portion 12 of the light-emitting tube 11 .
[0056] The mercury to be enclosed in the interior of the light-emitting portion 12 is for obtaining a required visible light wavelength, for example, radiant light having a wavelength of 360 to 780 nm, and the enclosed amount thereof is determined to be not lower than 0.15 mg/mm 3 in order to secure a high mercury vapor pressure not lower than 150 atmospheres, for example, at the time of lighting, and a high mercury vapor pressure not lower than 200 or 300 atmosphere may be obtained at the time of lighting by increasing the amount of enclosure of the mercury, so that a light source suitable for the projector apparatus may be realized.
[0057] The noble gas to be enclosed in the interior of the light-emitting portion 12 is for improving a lighting startability, and the enclosing pressure thereof is, for example, 10 to 26 kPa at static pressure. As the noble gas, argon gas may be preferably used.
[0058] The halogen enclosed in the interior of the light-emitting portion 12 is for forming halogen cycle in the interior of the light-emitting portion 12 , thereby suppressing tungsten as electrode substance from being adhered to an inner wall of the light-emitting portion 12 , and is enclosed in a form of a compound including mercury and other metals. The amount of enclosure of halogen is, for example, 1×10 −6 to 1×10 −2 μmol/mm 3 . Iodine, bromine, chlorine, and so on may be used as halogen.
[0059] In the interior of the light-emitting portion 12 , metal halide may be enclosed as still another charging medium.
[0060] To give a specific example of specifications of the discharge lamp 10 as described above, the maximum outer diameter of the light-emitting portion 12 of the light-emitting tube 11 is 10 mm and an inter-electrode distance of the same is 1.0 mm, an internal volume of the light-emitting portion 12 of the light-emitting tube 11 is 60 mm 3 , a rated voltage of the same is 75V, and a rated power of the same is 200 W.
[0061] In the discharge lamp 10 , a mercury vapor pressure in the interior of the light-emitting portion 12 of the light-emitting tube 11 while it is lit becomes, for example, not lower than 150 atmospheres, and in the projector apparatus in which the discharge lamp lighting apparatus is integrated therein, miniaturization of the entire apparatus is conducted, while a high light quantity is required, and hence the thermal condition in the interior of the light-emitting portion 12 of the light-emitting tube 11 of the discharge lamp 10 is quite strict, so that a bulb wall loading value of the lamp is, for example, 0.8 to 3.0 W/mm 2 and, more in detail, 2.0 W/mm 2 .
[0062] By having such a high mercury vapor pressure or a bulb wall loading value, radiant light having preferable color rendering properties may be obtained in the case of being used as the light source of the projector apparatus.
[0063] In the discharge lamp lighting apparatus according to a first embodiment, the power supply apparatus has a function to light the discharge lamp 10 by switching the mode between a first lighting mode in which rated power is supplied to the above-described discharge lamp 10 and a second lighting mode in which power lower than the rated power is supplied to the discharge lamp 10 , and is configured to control power to be supplied to the discharge lamp under the condition of an average power change ratio of 0.01 to 2.1 W/s, preferably, 0.08 to 0.77 W/s in a mode switching term in which the mode is switched from the first lighting mode to the second lighting mode.
[0064] Here, the power value to be supplied to the discharge lamp 10 in the second lighting mode is not specifically limited as long as being lower than the value of the rated power, and is selected normally within a range from 40 to 80% of the rated power. If the average power change ratio lower than 0.01 W/s in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, lowering of the power to be supplied is continued for a long time, so that blacking of the light-emitting tube 11 of the discharge lamp 10 may result. In contrast, if the average power change ratio exceeds 2.1 W/s, the lowering of the power to be supplied brings about abruptly in a short time, so that the flicker may occur while the discharge lamp 10 is lit in the second lighting mode after the mode switching term.
[0065] Also, the power supply apparatus is preferably configured to control the power to be supplied to the discharge lamp 10 under the condition that the average power change ratio is equal to or lower than 2.1 W/s in a mode switching term in which the mode is switched from the second lighting mode to the first lighting mode.
[0066] If the average power change ratio exceeds 2.1 W/s in the mode switching term in which the mode is switched from the second lighting mode to the first lighting mode, increase of the power to be supplied brings about abruptly in a short time, so that cracking of the light-emitting tube 11 of the discharge lamp 10 may result.
[0067] Although the lower limit of the average power change ratio is not specifically limited in the mode switching term in which the mode is switched from the second lighting mode to the first lighting mode, the time required for switching the mode is increased as lowering of the average power change ratio, so that the average power change ratio is preferably not lower than 0.01 W/s.
[0068] FIG. 2 is an explanatory drawing illustrating a configuration of an example of a circuit of a power supply apparatus used in the discharge lamp lighting apparatus according to the first embodiment. A power supply apparatus 20 includes a chopper circuit U 1 , a full bridge circuit U 2 , a starter circuit U 3 , and a control unit U 4 .
[0069] The chopper circuit U 1 includes a switching element Qx connected to a plus-side power source terminal to which a direct current voltage Vdc is supplied, a reactor Lx, a diode Dx whose cathode-side terminal is connected to a connecting point between the switching element Qx and the reactor Lx at a position between the connecting point and a minus-side power source terminal, a smoothing capacitor Cx connected to an output-side terminal of the reactor Lx, and a current detecting unit Rx connected to a one-side terminal of the smoothing capacitor Cx and an anode-side terminal of the diode Dx. The switching element Qx is configured to be driven by a drive circuit Gx operated on the basis of a signal output from the control unit U 4 , and turned ON/OFF by a predetermined duty, and the power to be supplied to the discharge lamp 10 is controlled by the duty.
[0070] The full bridge circuit U 2 includes four switching elements Q 1 to Q 4 connected in a bridge pattern. The switching elements Q 1 to Q 4 are driven by drive circuits G 1 to G 4 corresponding to the respective switching elements Q 1 to Q 4 being operated on the basis of a signal output from a full bridge control circuit Gw, and a square wave-shaped AC voltage is generated between a connecting point between the switching elements Q 1 , Q 2 and a connecting point between the switching elements Q 3 , Q 4 by turning the switching elements Q 1 , Q 4 and the switching elements Q 2 , Q 3 arranged at opposing corners in an ON state alternately.
[0071] The starter circuit U 3 includes a coil Lh and a capacitor Ch. In the starter circuit U 3 configured as described above, a resonant frequency of a resonant circuit of the coil Lh and the capacitor Ch is output from the full bridge circuit U 2 , so that a high voltage may be generated from the capacitor Ch by a resonant effect thereof. Therefore, the starter circuit U 3 is operated at a high frequency only at the time of starting of the discharge lamp 10 , whereby a high voltage is applied between a pair of the electrodes of the discharge lamp 10 and the discharge lamp 10 is lit.
[0072] In the power supply apparatus 20 as described above, the power to be supplied to the discharge lamp 10 is set by ON/OFF duty of the switching element Qx of the chopper circuit U 1 . The switching element Qx of the chopper circuit U 1 is turned ON and OFF by a predetermined duty of the drive circuit Gx on the basis of the signal output from the control unit U 4 , whereby the power to be supplied to the discharge lamp 10 is adjusted. When the power value to be supplied to the discharge lamp 10 is increased for example, the power value to be supplied to the discharge lamp 10 is controlled by the drive circuit Gx so as to match a preset reference voltage value by lowering the duty or the like.
[0073] In this manner, the control unit U 4 has a function to control the power value to be supplied to the discharge lamp 10 so as to match the reference power value, and has a function to change the power value to be supplied to the discharge lamp 10 not instantaneously, but at a predetermined power change ratio when changing the lighting mode of the discharge lamp 10 at the time of being steadily lit.
[0074] More specifically, a predetermined power value is set to a power setting unit 50 in the control unit U 4 . For example, a rated power value is set to the power setting unit 50 when the discharge lamp 10 is lit in the first lighting mode, and a power value lower than the rated power value is set to the power setting unit 50 when the discharge lamp 10 is lit in the second lighting mode. The power setting unit 50 may be provided in an interior of the power supply apparatus 20 or on the outside of the power supply apparatus 20 , for example, in the interiors of an apparatuses other than the discharge lamp lighting apparatus in the projector apparatus.
[0075] A power change ratio when changing the power in the power setting unit 50 is set in a power change ratio setting unit 51 .
[0076] A set power signal from the power setting unit 50 , a change ratio signal from the power change ratio setting unit 51 , and a time signal from a timer circuit 53 are input to a reference power setting unit 52 , and a reference power signal which is changed with elapsed time is output on the basis of these signals. For example, when the rated power value is initially set in the power setting unit 50 and a low power value lower than the rated power value is set at a certain time point, in the reference power setting unit 52 , the reference power value is changed from the rated power value to the low power value while receiving the time signal from the timer circuit 53 on the basis of the power change ratio set in the power change ratio setting unit 51 . For example, when the rated power value is 230 W, the low power value is 180 W, and the power change ratio is 2.00 W/s, the reference power value is changed from the rated power value (230 W) to the low power value (180 W) by spending 25 seconds, and subsequently, the reference power setting unit 52 outputs a reference power signal having the low power value (180 W) unless otherwise a new power value is set in the power setting unit 50 .
[0077] Signals from a voltage detecting unit Vx and the current detecting unit Rx are input to a power calculating circuit 54 , and a power value of a lighting power is calculated on the basis of these signals, the obtained lighting power signal is input to a comparing unit 55 , and in this comparing unit 55 , the lighting power signal is compared with the reference power signal from the power setting unit 50 . The signal output from the comparing unit 55 is input to the drive circuit Gx of the switching element Qx via a PWM circuit 56 .
[0078] The full bridge circuit U 2 contributes to a lighting frequency of the discharge lamp 10 as described above, and the respective drive circuits G 1 to G 4 are driven so as to achieve the frequency set in the full bridge circuit U 2 .
[0079] In the discharge lamp lighting apparatus according to the first embodiment, the discharge lamp 10 is lit by the supply of the AC power from the power supply apparatus 20 to the discharge lamp 10 , and the power to be supplied to the discharge lamp 10 by the power supply apparatus 20 is controlled, for example, as described below.
[0080] FIG. 3 is a graph illustrating an example of a change of value of power supplied to the discharge lamp in a case where the mode is switched from the first lighting mode to the second lighting mode in the discharge lamp lighting apparatus according to the first embodiment. In this graph, the vertical axis indicates a ratio of the power value to be actually supplied to the discharge lamp 10 with respect to the rated power value of the discharge lamp 10 (the ratio of the supply power value assuming that the rated power value is determined to be 100%), and the lateral axis indicates a lighting time of the discharge lamp 10 .
[0081] First of all, when the power supply apparatus 20 is driven in a state in which the first lighting mode is selected as the lighting mode, power in the first lighting mode, specifically, AC power having a power value corresponding to the rated power of the discharge lamp 10 is supplied from the power supply apparatus 20 to the discharge lamp 10 , whereby the discharge lamp 10 is lit. Subsequently, if the lighting mode is changed from the first lighting mode to the second lighting mode in the power supply apparatus 20 when a time T 1 is elapsed since the lighting of the discharge lamp 10 in the first lighting mode is started, the power value of the AC power to be supplied from the power supply apparatus 20 is lowered at a predetermined average power change ratio selected from a range of 0.01 to 2.1 W/s in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, and when a time T 2 is elapsed from the change of the lighting mode from the first lighting mode to the second lighting mode, the power value of AC power to be supplied to the discharge lamp 10 reaches the power value of the power in the second lighting mode, and the lighting of the discharge lamp 10 in the second lighting mode is started.
[0082] Here, to give a detailed example of the length of the mode switching term, that is, the time T 2 taken until the power value supplied to the discharge lamp 10 is lowered from the value of the supply power in the first lighting mode to the value of the supply power in the second lighting mode, T 2 =(200 W−120 W)÷2.0 W/s=40 s is satisfied, where a rated power value of the discharge lamp 10 is 200 W, the value of the supply power in the second lighting mode is 120 W (60% of the rated power), and the average power change ratio in the mode switching term is 2.0 W/s, for example.
[0083] Also, when the lighting mode is changed from the second lighting mode to the first lighting mode in the power supply apparatus 20 , the power value of the AC power to be supplied from the power supply apparatus 20 is increased at the predetermined average power change ratio equal to or lower than 2.1 W/s in the mode switching term in which the mode is switched from the second lighting mode to the first lighting mode, and subsequently, the power value of the AC power to be supplied to the discharge lamp 10 reaches the power value of the power in the first lighting mode, and the lighting of the discharge lamp 10 in the first lighting mode is started.
[0084] In the description given above, a current waveform of the AC power to be supplied to the discharge lamp 10 preferably has a form in which a low-frequency component having a frequency lower than a basic frequency component is cyclically inserted into the basic frequency component.
[0085] An example of the current waveform of the AC power to be supplied to the discharge lamp 10 will be illustrated in FIG. 4 . In this drawing, the vertical axis indicates the current power value of the power to be supplied to the discharge lamp 10 , and the lateral axis indicates the lighting time of the discharge lamp 10 . In this current waveform, a low-frequency component F 2 having a frequency lower than the basic frequency component is cyclically inserted into a basic frequency component F 1 .
[0086] The frequency of the basic frequency component F 1 is selected, for example, from a range from 60 to 1000 Hz. In contrast, the frequency of the low-frequency component F 2 is a frequency lower than the frequency of the basic frequency component F 1 , and is selected, for example, from a range from 5 to 200 Hz.
[0087] The low-frequency component F 2 may have a length of half a cycle, and an insertion interval of the low-frequency component F 2 (the time interval from when a certain low frequency component is inserted until when the next low-frequency component is inserted) is preferably not more than 120 seconds and, more preferably, from 0.01 to 120 seconds. Specific frequencies of the basic frequency component F 1 and the low-frequency component F 2 , an insertion interval of the low-frequency component F 2 , and the amplitude of the low-frequency component F 2 are selected as needed by considering the design of the discharge lamp 10 to be used, specifically, a relation with respect to a thermal design of the electrodes 14 , 15 or the values of the power in the respective lighting modes or the like.
[0088] To give a specific example of the current waveform, the frequency of the basic frequency component F 1 is 370 Hz, the length of the one basic frequency component F 1 is 37.5 cycle, the frequency of the low-frequency component F 2 is 90 Hz, and the length of the one low-frequency component F 2 is 1 cycle.
[0089] In the discharge lamp lighting apparatus according to the first embodiment, when the power in the first lighting mode is supplied from the power supply apparatus 20 to the discharge lamp 10 , arcs A are formed between a pair of the electrodes 14 , 15 of the discharge lamp 10 as the projections p 1 formed at the distal ends of the head portions 14 a , 15 a of the respective electrodes 14 , 15 as original points as illustrated in FIG. 5( a ). Then, in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, as illustrated in FIG. 5( b ), the shape of the arcs A formed between the electrodes 14 , 15 becomes narrower as the value of power supplied to the discharge lamp is lowered, so that the evaporated electrode substance is accumulated at positions on surfaces of the projections p 1 of the respective electrodes 14 , 15 where the original points of the arcs A are positioned by a halogen cycle, whereby minute projections p 2 are formed on the surfaces of the projections p 1 on the respective electrodes 14 , 15 as illustrated in FIG. 5( c ).
[0090] Therefore, according to the discharge lamp lighting apparatus of the first embodiment, the power to be supplied to the discharge lamp 10 is controlled by the power supply apparatus 20 under the condition in which the average power change ratio becomes a value from 0.01 to 2.1 W/s in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, whereby the original points of the arcs A do not move on the surfaces of the projections p 1 of the respective electrodes 14 , 15 , and the stable arcs A are formed, so that a plurality of the minute projections p 2 are not formed on the surfaces of the projections p 1 on the respective electrodes 14 , 15 , and hence occurrence of the flicker may be prevented or suppressed while the discharge lamp 10 is lit in the second lighting mode.
[0091] In the discharge lamp lighting apparatus according to a second embodiment, the power supply apparatus has a function to light the discharge lamp 10 by switching the mode between the first lighting mode in which rated power is supplied to the above-described discharge lamp 10 and the second lighting mode in which the power lower than the rated power is supplied to the discharge lamp 10 , and is configured to control the power to be supplied to the discharge lamp 10 under the condition including the power change such that the power value is lowered from a given power value P 1 equal to or lower than the supply power in the first lighting mode and equal to or higher than the supply power in the second lighting mode to a power value P 2 lower than the power value P 1 in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, and then is increased from the power value P 2 to a power value P 3 higher than the power value P 2 and lower than the power value P 1 (hereinafter, referred to as “specific power change”). Here, the power value to be supplied to the discharge lamp 10 in the second lighting mode is not specifically limited as long as being lower than the value of the rated power, and is selected normally within a range from 40 to 80% of the rated power.
[0092] Although the specific power change has only to be performed at least once in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, it is preferably performed twice or more. In particular, when the difference in power value between the supply power in the first lighting mode and the supply power in the second lighting mode is significant, it is preferably performed three times or more little by little.
[0093] In the specific power change, the power value P 1 may be determined arbitrarily without being specifically limited as long as being values equal to and lower than the supply power in the first lighting mode and equal to and higher than the supply power in the second lighting mode. The power value P 2 has only to be a value lower than the power value P 1 , and may be a value lower than the supply power in the second lighting mode, for example. However, a difference (P 1 −P 2 ) between the power value P 1 and the power value P 2 is preferably on the order of 5 to 50% of the power value of the supply power in the first lighting mode.
[0094] The power value P 3 has only to be a value higher than the power value P 2 and lower than the power value P 1 , and a difference (P 3 −P 2 ) between the power value P 3 and the power value P 2 is preferably on the order of 2 to 50% of the difference (P 1 -P 2 ) between the power value P 1 and the power value P 2 .
[0095] When the specific power change is performed twice or more, the last specific power change is preferably the power change which is lowered from the power value P 1 to the power value P 2 which is a lower value than the supply power in the second lighting mode and then is increased to the power value P 2 which corresponds to the supply power in the second lighting mode.
[0096] Also, the average power change ratio when the power value to be supplied to the discharge lamp 10 is lowered from the power value P 1 to the power value P 2 is preferably from 0.1 to 10 W/s.
[0097] Also, the average power change ratio when the power value to be supplied to the discharge lamp 10 is increased from the power value P 2 to the power value P 3 is preferably from 0.1 to 10 W/s.
[0098] In the discharge lamp lighting apparatus according to the second embodiment, the discharge lamp 10 is lit by the supply of the AC power from the power supply apparatus to the discharge lamp 10 , and the power value to be supplied to the discharge lamp 10 by the power supply apparatus is controlled, for example, as described below.
[0099] FIG. 6 is a graph illustrating an example of the change of value of power supplied to the discharge lamp in the case where the mode is switched from the first lighting mode to the second lighting mode in the discharge lamp lighting apparatus according to the second embodiment. In this graph, the vertical axis indicates a ratio of the power value to be actually supplied to the discharge lamp 10 with respect to the rated power value of the discharge lamp 10 (the ratio of the supply power value assuming that the rated power value is determined to be 100%), and the lateral axis indicates the lighting time of the discharge lamp 10 .
[0100] First of all, when the power supply apparatus is driven in a state in which the first lighting mode is selected as the lighting mode, power in the first lighting mode, specifically, AC power having a power value corresponding to the rated power of the discharge lamp 10 is supplied from the power supply apparatus to the discharge lamp 10 , whereby the discharge lamp 10 is lit. Subsequently, if the lighting mode is changed from the first lighting mode to the second lighting mode in the power supply apparatus when the time T 1 is elapsed since the lighting of the discharge lamp 10 in the first lighting mode is started, the power to be supplied to the discharge lamp 10 is lowered while performing the power change such that the power value is lowered from the given power value P 1 which is lower than the supply power in the first lighting mode and equal to or higher than the supply power in the second lighting mode to the power value P 2 lower than the power value P 1 , and then, is increased from the power value P 2 to the power value P 3 higher than the power value P 2 and lower than the power value P 1 in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, and when the time T 2 is elapsed since the change of the lighting mode from the first lighting mode to the second lighting mode, the power value of AC power to be supplied to the discharge lamp 10 reaches the power value of the power in the second lighting mode, and the lighting of the discharge lamp 10 in the second lighting mode is started.
[0101] In the description given above, the current waveform of the AC power to be supplied to the discharge lamp 10 is preferably a form in which a low-frequency component having a lower frequency than a basic frequency component is cyclically inserted into the basic frequency component.
[0102] As an example the current waveform of the AC power supplied to the discharge lamp 10 , the one exemplified in conjunction with the discharge lamp lighting apparatus according to the first embodiment, that is, those illustrated in FIG. 4 may be presented.
[0103] The frequency of the basic frequency component F 1 is selected, for example, from a range from 60 to 1000 Hz. In contrast, the frequency of the low-frequency component F 2 is the frequency lower than the frequency of the basic frequency component F 1 , and is selected, for example, from a range from 5 to 200 Hz.
[0104] The low-frequency component may have a length of half a cycle, and an insertion interval of the low-frequency component (the time interval from when a certain low frequency component is inserted until when the next low-frequency component is inserted) is preferably not more than 120 seconds and, more preferably, from 0.01 to 120 seconds.
[0105] Specific frequencies of the basic frequency component F 1 and the low-frequency component F 2 , an insertion interval of the low-frequency component F 2 , and the amplitude of the low-frequency component F 2 are selected as needed by considering the design of the discharge lamp 10 to be used, specifically, the relation with respect to the thermal design of the electrodes 14 , 15 or the values of the power in the respective lighting modes and the like.
[0106] To give a specific example of the current waveform, the frequency of the basic frequency component F 1 is 370 Hz, the length of the one basic frequency component F 1 is 37.5 cycle, the frequency of the low-frequency component F 2 is 90 Hz, and the length of the one low-frequency component F 2 is 1 cycle.
[0107] In the discharge lamp lighting apparatus according to the second embodiment, when the power in the first lighting mode is supplied from the power supply apparatus to the discharge lamp 10 , the arcs A are formed between a pair of the electrodes 14 , 15 of the discharge lamp 10 as the projections p 1 formed at the distal ends of the head portions 14 a , 15 a of the respective electrodes 14 , 15 as original points as illustrated in FIG. 7( a ).
[0108] Then, in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, when the power to be supplied to the discharge lamp 10 is lowered from the power value P 1 to the power value P 2 , as illustrated in FIG. 7( b ), the shape of the arcs A formed between the electrodes 14 , 15 becomes narrower, so that the evaporated electrode substance is accumulated at positions on the surfaces of the projections p 1 of the respective electrodes 14 , 15 where the original points of the arcs A are positioned by the halogen cycle, whereby the minute projections p 2 are formed on the surfaces of the projections p 1 of the respective electrodes 14 , 15 as illustrated in FIG. 7( c ). At this time, since the shape of the arcs A formed between the electrodes 14 , 15 is abruptly narrowed, the arcs A formed between the electrodes 14 , 15 become unstable by the movement of the original points on the surfaces of the projections p 1 of the respective electrodes 14 , 15 as illustrated in FIG. 7( d ) and, consequently, a plurality of the minute projections p 2 are formed on the surfaces of the projections p 1 of the respective electrodes 14 , 15 as illustrated in FIG. 7( e ). Therefore, when the power to be supplied to the discharge lamp 10 is increased from the power value P 2 to the power value P 3 , as illustrated in FIG. 7( t ), the shape of the arcs A formed between the electrodes 14 , 15 becomes thicker and a plurality of the minute projections p 2 are melted, whereby the minute projections p 2 converge into one as illustrated in FIG. 7( g ).
[0109] In this manner, according to the discharge lamp lighting apparatus of the second embodiment, since the AC power to be supplied to the discharge lamp 10 is controlled after lowering from the power value P 1 to the power value P 2 under the condition including the power change increased from the power value P 2 to the power value P 3 higher than the power value P 2 and lower than the power value P 1 in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode, even though a plurality of the minute projections p 2 are formed on the surfaces of the projections p 1 of the electrodes 14 , 15 when the AC power to be supplied to the discharge lamp 10 is lowered from the power value P 1 to the power value P 2 , a plurality of the minute projections p 2 are converged into one minute projection p 2 and the electrodes 14 , 15 are repaired when the AC power to be supplied to the discharge lamp 10 is increased from the power value P 2 to the power value P 3 , so that the occurrence of flicker may be prevented or suppressed while the discharge lamp 10 is lit in the second lighting mode.
[0110] In the discharge lamp lighting apparatus according to a third embodiment, the power supply apparatus has a function to light the discharge lamp 10 by switching the mode between the rated power lighting mode in which the rated power is supplied to the above-described discharge lamp 10 and the low power lighting mode in which power lower than the rated power is supplied to the discharge lamp 10 , and is configured to supply basic AC power of the predetermined power value continuously to the discharge lamp 10 in the low power lighting mode, and supply superimposed power superimposed on this basic AC power cyclically.
[0111] Here, the power value of the basic AC power in the low power lighting mode is not specifically limited as long as being lower than the value of the rated power, and is selected normally within a range from 40 to 80% of the rated power.
[0112] The current waveform of the AC power to be supplied to the discharge lamp 10 is preferably a form in which a low-frequency component having a lower frequency than a basic frequency component is cyclically inserted into the basic frequency component.
[0113] As an example of the current waveform of the AC power supplied to the discharge lamp 10 , the one exemplified in conjunction with the discharge lamp lighting apparatus according to the first embodiment, that is, those illustrated in FIG. 4 may be presented.
[0114] The frequency of the basic frequency component F 1 is selected, for example, from a range from 60 to 1000 Hz. In contrast, the frequency of the low-frequency component F 2 is a frequency lower than the frequency of the basic frequency component F 1 , and is selected, for example, from a range from 5 to 200 Hz.
[0115] The low-frequency component may have a length of half a cycle, and an insertion interval of the low-frequency component (the time interval from when a certain low frequency component is inserted until when the next low-frequency component is inserted) is preferably not more than 120 seconds and, more preferably, from 0.01 to 120 seconds.
[0116] Detailed frequencies of the basic frequency component F 1 and the low-frequency component F 2 , an insertion interval of the low-frequency component F 2 , and the amplitude of the low-frequency component F 2 are selected as needed by considering the design of the discharge lamp 10 to be used, specifically, a relation with respect to a thermal design of the electrodes 14 , 15 or the values of the power in the respective lighting modes.
[0117] Also, the basic frequency component of the basic AC power in the low power lighting mode is preferably a frequency higher than the basic frequency component of the AC current in the rated power lighting mode and, for example, is preferably 1.1 to 10 times the frequency of the basic frequency component of the AC current in the rated power lighting mode.
[0118] Also, the low frequency component of the superimposed power in the low power lighting mode is preferably a frequency lower than the low frequency component in the rated power lighting mode and, for example, is preferably 10 to 95% of the frequency of the low frequency component of the rated power.
[0119] To give a specific example, when the rated power of the discharge lamp 10 is 230 W, and the basic AC power in the low power lighting mode is 75% of the rated power, the basic frequency component of the AC current in the rated voltage lighting mode is 370 Hz, the low-frequency component is 46.25 Hz, the basic frequency component of the basic AC power in the low power lighting mode is 518 Hz, and the low-frequency component of the superimposed power is 37 Hz.
[0120] Then, the supply timing of the superimposed power, the power value of the superimposed power, or the supply time of the superimposed power is controlled by the power supply apparatus according to a measured value of a lighting voltage of the discharge lamp 10 . Here, the measured value of the lighting voltage of the discharge lamp 10 may be a value measured when the superimposed power is supplied (hereinafter, referred to as “when the power is superimposed”), or may be a value measured when the superimposed power is not supplied (hereinafter, referred to as “when the power is not superimposed”).
[0121] FIG. 8 is a drawing illustrating a change of value of power supplied to the discharge lamp in the low power lighting mode in an example of the power supply apparatus along with the change of lighting voltage of the discharge lamp.
[0122] The power supply apparatus of this example is configured to control the supply timing of the superimposed power according to the measured value of the lighting voltage of the discharge lamp 10 in the low power lighting mode. To give a specific description, when the measured value of the lighting voltage of the discharge lamp 10 is lower than a predetermined reference value V 0 , the basic AC power having a power value P 1 is supplied to the discharge lamp 10 and, simultaneously, the superimposed power having a power value P 2 is supplied by being superimposed on the basic AC power cyclically for a predetermined supply time T at a predetermined time interval t 1 . When the measured value of the lighting voltage of the discharge lamp 10 is increased beyond the reference value V 0 , the superimposed power having the power value P 2 is supplied to the discharge lamp 10 by being superimposed on the basic AC power cyclically for the predetermined supply time T at the predetermined time interval t 2 which is shorter than the time interval t 2 , that is, the time interval of the superimposed power is changed from t 1 to t 2 which is shorter than t 1 . When the measured value of the lighting voltage of the discharge lamp 10 is lowered again beyond the reference value V 0 , the superimposed power of the power value P 2 is supplied to the discharge lamp 10 by being superimposed on the basic AC power cyclically for a predetermined supply time T at a predetermined time interval t 1 , that is, the time interval of the superimposed power is changed from t 2 to t 1 .
[0123] In the description given above, the reference value V 0 of the lighting voltage is set as needed considering the specifications of the discharge lamp 10 , the power value P 1 of the basic AC power, power value P 2 of the superimposed power, the supply time T of the superimposed power, the time intervals t 1 , t 2 of the superimposed power and so on supplied to the discharge lamp 10 in the low power lighting mode. For example, it is preferable to make the set value of the reference value V 0 of the lighting voltage higher as the set values of the time intervals t 1 , t 2 of the superimposed power are increased.
[0124] The time interval t 1 of the superimposed power when the lighting voltage is lower than the reference value V 0 is preferably set within a range from 1 to 60 minutes, for example, although it depends on the basic AC power P 1 , the power value P 2 of the superimposed power, and the supply time T of the superimposed power, and so on.
[0125] The time interval t 2 of the superimposed power when the lighting voltage is higher than the reference value V 0 only needs to be shorter than the time interval t 1 , and is set as needed considering the power value P 1 of the basic AC power, power value P 2 of the superimposed power, the supply time T of the superimposed power, the reference value V 0 of the lighting voltage, and so on. For example, it is preferable to make the set value of the time interval t 2 of the superimposed power shorter as the set value of the reference value V 0 of the lighting voltage is increased.
[0126] The supply time T of the superimposed power is preferably selected within a range from 1 to 10 minutes, for example, although it depends on the power value P 1 of the basic AC power, the power value P 2 of the superimposed power, and the time interval t 1 of the superimposed power and the like.
[0127] The power value P 2 of the superimposed power is preferably set within a range from 65 to 120% of the rated power, for example, although it depends on the power value P 1 of the basic AC power, the supply time T of the superimposed power, the time interval t 1 of the superimposed power, and so on.
[0128] A further specific example will be given as follows.
[0129] Superimposed power of 173 W is supplied to supply power of 230 W in the rated power lighting mode and supply power of 138 W in the low power lighting mode, and parameters of the supply power and the superimposed power in the low power lighting mode are set according to a lamp voltage in either mode.
[0130] When the lamp voltage is lower than the reference value of the lighting voltage, the time interval of the superimposed power is elongated, and when the lamp voltage is higher than the above-described reference value, the time interval of the superimposed power is shortened. For example, when the lamp voltage is lower than a reference value of 100V, the time interval of the superimposed power is set to 15 minutes, and when the lamp voltage is equal to or higher than the reference value of 100 V, the time interval of the superimposed power is set to 5 minutes.
[0131] For reference, the supply time of the superimposed power is 2 minutes in both cases.
[0132] Alternatively, when the lamp voltage is lower than the reference value of the lighting voltage, the supply time of the superimposed power is shortened, and when the lamp voltage is higher than the reference value, the supply time of the superimposed power is elongated. For example, when the lamp voltage is lower than the reference value of 100 V, the supply time of the superimposed power is set to 2 minutes, and when the lamp voltage is equal to or higher than the reference value of 100 V, the supply time of the superimposed power is set to 4 minutes.
[0133] Also, the time interval of the superimposed power is 15 minutes in both cases.
[0134] To give a specific example of the set value of the supply power in the low power lighting mode in such a power supply apparatus, when the rated power of the discharge lamp 10 is 230 W, the power value P 1 of the basic AC power is 138 W (60% of the rated power), the power value P 2 of the superimposed power is 35 W, the supply time of the superimposed power is 2 minutes, the time interval t 1 of the superimposed power is 15 minutes, the time interval t 2 of the same is 5 minutes, and the reference value V 0 of the lighting voltage measured when the power is superimposed is 80 V.
[0135] FIG. 9 illustrates the change of value of power supplied to the discharge lamp in the low power lighting mode in another example of the power supply apparatus in the discharge lamp lighting apparatus according to the third embodiment along with the change of the lighting voltage of the discharge lamp.
[0136] The power supply apparatus of this example is configured to control the power value of the superimposed power according to the measured value of the lighting voltage of the discharge lamp 10 in the low power lighting mode. To give a specific description, when the measured value of the lighting voltage of the discharge lamp 10 is lower than the predetermined reference value V 0 , the basic AC power having the power value P 1 is supplied to the discharge lamp 10 and, simultaneously, the superimposed power having the power value P 2 is supplied by being superimposed on the basic AC power cyclically for the predetermined supply time T at a predetermined time interval t. When the measured value of the lighting voltage of the discharge lamp 10 is increased beyond the predetermined reference value V 0 , the superimposed power having the predetermined power value P 3 higher than the power value P 2 is supplied to the discharge lamp 10 by being superimposed on the basic AC power cyclically for the predetermined supply time T at the time interval t, that is, the power value of the superimposed power is changed from P 2 to P 3 higher than P 2 . Also, when the measured value of the lighting voltage of the discharge lamp 10 is lowered again beyond the predetermined reference value V 0 , the superimposed power having the predetermined power value P 2 is supplied to the discharge lamp 10 by being superimposed on the basic AC power cyclically for the predetermined supply time T at the time interval t, that is, the power value of the superimposed power is changed from P 3 to P 2 .
[0137] To give a specific example of the set value of the supply power in the low power lighting mode in such a power supply apparatus, when the rated power of the discharge lamp 10 is 230 W, the power value P 1 of the basic AC power is 138 W (60% of the rated power), the power value P 2 of the superimposed power is 35 W, the power value P 3 of the same is 92 W, the supply time T of the superimposed power is 2 minutes, the time interval t of the superimposed power is 15 minutes, and the reference value V 0 of the lighting voltage measured when the power is not superimposed is 70 V
[0138] FIG. 10 is a drawing illustrating a change of value of power supplied to the discharge lamp in the low power lighting mode in still another example of the power supply apparatus in the discharge lamp lighting apparatus according to the third embodiment along with the change of the lighting voltage of the discharge lamp.
[0139] The power supply apparatus of this example is configured to control the supply time of the superimposed power according to the measured value of the lighting voltage of the discharge lamp 10 in the low power lighting mode. To give a specific description, when the measured value of the lighting voltage of the discharge lamp 10 is lower than the predetermined reference value V 0 , the basic AC power having the power value P 1 is supplied to the discharge lamp 10 and, simultaneously, the superimposed power having the power value P 2 is supplied by being superimposed on the basic AC power cyclically for a predetermined supply time T 1 at the predetermined time interval t. When the measured value of the lighting voltage of the discharge lamp 10 is increased beyond the predetermined reference value V 0 , the superimposed power having the power value P 2 is supplied to the discharge lamp 10 by being superimposed on the basic AC power cyclically for a predetermined supply time T 2 which is longer than the supply time T 1 at the predetermined time interval t, that is, the supply time of the superimposed power is changed from T 1 to T 2 which is longer than T 1 . Also, when the measured value of the lighting voltage of the discharge lamp 10 is lowered again beyond the predetermined reference value V 0 , the superimposed power having the predetermined power value P 2 is supplied to the discharge lamp 10 by being superimposed on the basic AC power cyclically for the predetermined supply time T 1 at the predetermined time interval t, that is, the supply time of the superimposed power is changed from T 2 to T 1 .
[0140] To give a specific example of the set value of the supply power in the low power lighting mode in such a power supply apparatus, when the rated power of the discharge lamp 10 is 230 W, the power value P 1 of the basic AC power is 138 W (60% of the rated power), the power value P 2 of the superimposed power is 35 W, the supply time T 1 of the superimposed power is 2 minutes, the supply time T 2 of the same is 4 minutes, the time interval t of the superimposed power is 1.5 minutes, and the reference value V 0 of the lighting voltage measured when the power is not superimposed is 70 V.
[0141] According to the discharge lamp lighting apparatus of the third embodiment, the superimposed power which is superimposed on the basic AC power having the predetermined power value is cyclically supplied to the discharge lamp 10 , and the supply timing of the superimposed power, the power value of the superimposed power, or the supply time of the superimposed power is controlled in the low power lighting mode in which power lower than the rated power is supplied to the discharge lamp 10 by the power supply apparatus, so that the amount of the evaporated electrode substance existing in the periphery of the electrodes 14 , 15 of the discharge lamp 10 is increased, whereby accumulation of the evaporated electrode substance on the electrodes 14 , 15 of the discharge lamp 10 is accelerated, and hence occurrence of wearing and flicker of the electrodes 14 , 15 of the discharge lamp 10 may be prevented or suppressed.
[0142] The discharge lamp lighting apparatus of the present invention is not limited to the above-described embodiments, and various modifications may be made. For example, the form of the electrodes of the discharge lamp is not limited to those illustrated in FIG. 1 and, for example, may be those having head portions of a truncated conical shape.
[0143] In the first embodiment, for example, the power supply apparatus may have a function to light the discharge lamp by switching the mode between the above-described second lighting mode and a third lighting mode in which power lower than the supply power in the second lighting mode is supplied to the discharge lamp.
[0144] In the discharge lamp lighting apparatus as described above, the power supply apparatus is preferably configured to control the power to be supplied to the discharge lamp under the condition that the average power change ratio becomes a value from 0.01 to 2.1 W/s in the mode switching term in which the mode is switched from the second lighting mode to the third lighting mode and, in addition, is preferably configured to control the power to be supplied to the discharge lamp 10 under the condition that the average power change ratio is equal to or lower than 2.1 W/s in the mode switching term in which the mode is switched from the third lighting mode to the second lighting mode.
[0145] Also, the power supply apparatus does not need to lower the power to be supplied to the discharge lamp under the condition that the power change ratio is always constant in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode and, as illustrated in FIG. 11 , the power to be supplied to the discharge lamp may be controlled so as to be lowered from the power value in the first lighting mode to the power value in the second lighting mode while repeating lowering of the power value and maintenance of the power value alternately.
[0146] Also, in the mode switching term in which the mode is switched from the second lighting mode to the first lighting mode, the power to be supplied to the discharge lamp may be controlled so as to increase from the power value in the second lighting mode to the power value in the first lighting mode while repeating increase of the power value and maintenance of the power value alternately.
[0147] Furthermore, when the power supply apparatus is configured to have a function to light the discharge lamp by switching the mode between the second lighting mode and the third lighting mode in which the power lower than the supply power in the second lighting mode is supplied to the discharge lamp, the power to be supplied to the discharge lamp may be controlled so as to be lowered from the power value in the second lighting mode to the power value in the third lighting mode, or to be increased from the power value in the third lighting mode to the power value in the second lighting mode while repeating lowering of the power value and maintenance of the power value alternately, or repeating increase of the power value and maintenance of the power value alternately in the mode switching term in which the mode is switched from the second lighting mode to the third lighting mode or in the mode switching term in which the mode is switched from the third lighting mode to the second lighting mode.
[0148] When performing the power control as described above, the power to be supplied to the discharge lamp has only to be controlled under the condition that the average power change ratio in the respective mode switching terms, that is, in a term from t 1 to t 2 in FIG. 11 becomes a value from 0.01 to 2.1 W/s.
[0149] Also, the power supply apparatus is not limited to the configuration illustrated in FIG. 2 , but various circuit configurations are applicable.
[0150] In the second embodiment, for example, the power supply apparatus may have a function to light the discharge lamp by switching the mode between the above-described second lighting mode and the third lighting mode in which the power lower than the supply power in the second lighting mode is supplied to the discharge lamp.
[0151] In the discharge lamp lighting apparatus as described above, the power supply apparatus is preferably configured to control the power to be supplied to the discharge lamp under the condition including the power change such that the power value is lowered from a given power value P 1 equal to or lower than the supply power in the second lighting mode and equal to or higher than the supply power in the third lighting mode to the power value P 2 lower than the power value P 1 , and then is increased from the power value P 2 to the power value P 3 higher than the power value P 2 and lower than the power value P 1 in a switching term in which the mode is switched from the second lighting mode to the third lighting mode.
[0152] Also, in the power supply apparatus, the power change increasing from the power value P 2 to the power value P 3 does not have to be performed continuously for the power change lowering from the power value P 1 to the power value P 2 in the mode switching term in which the mode is switched from the first lighting mode to the second lighting mode and, as illustrated in FIG. 12 for example, the power value may be lowered from the power value P 1 to the power value P 2 , be maintained at the power value P 2 , and then be increased from the power value P 2 to the power value P 3 .
[0153] Also, when the power supply apparatus is configured to have a function to light the discharge lamp by switching the mode to or from the third lighting mode in which the power lower than the supply power in the second lighting mode is supplied to the discharge lamp, the power value may be lowered from the power value P 1 to the power value P 2 , be maintained at the power value P 2 , and then be increased from the power value P 2 to the power value P 3 in the mode switching term in which the mode is switched from the second switching mode to the third lighting mode.
[0154] In the third embodiment, although the power supply apparatus is configured to control one of the supply timing of the superimposed power, the power value of the superimposed power, and the supply time of the superimposed power all in accordance with the measured value of the lighting voltage of the discharge lamp 10 , the power supply apparatus may be configured to control two of the supply timing of the superimposed power, the power value of the superimposed power, and the supply time of the superimposed power, or to control all of the supply timing of the superimposed power, the power value of the superimposed power, and the supply time of the superimposed power.
[0155] Also, the power supply apparatus may be configured to have two or more preset reference values of the lighting voltage of the discharge lamp 10 and control the supply timing of the superimposed power, the power value of the superimposed power, or the supply time of the superimposed power on the basis of the respective reference values.
[0156] The power supply apparatus may be configured to be set to zero as the supply of the superimposed power (a state in which the superimposed power is not supplied) when the measured value of the lighting voltage of the discharge lamp is lower than the predetermined reference value.
Manufacture of Discharge Lamp
[0157] According to the configuration illustrated in FIG. 1 , a discharge lamp (A) and a discharge lamp (B) having the following specifications were manufactured.
Discharge Lamp (A):
[0158] The light-emitting tube was formed of quartz glass, and the maximum diameter of the light-emitting portion was 10 mm, and the internal volume of the light-emitting portion was 65 mm 3 .
[0159] The respective electrodes were formed of tungsten, and the inter-electrode distance was 1.0 mm.
[0160] 0.3 mg/mm 3 of mercury, 13 kPa of argon gas at a static pressure, and halogen (Br) of 4.0×10 −4 μmol/mm 3 were enclosed in the interior of the light-emitting tube.
[0161] The rated power of the discharge lamp (A) was 230 W, the rated voltage was 80 V, and the bulb wall loading value was 2.5 W/mm 2 .
Discharge Lamp (B):
[0162] The light-emitting tube was formed of quartz glass, and the maximum diameter of the light-emitting portion was 9.4 mm, and the internal volume of the light-emitting portion was 50 mm 3 .
[0163] The respective electrodes were formed of tungsten, and the inter-electrode distance was 0.7 mm.
[0164] 0.3 mg/mm 3 of mercury, 13 kPa of argon gas at a static pressure, and halogen (Br) of 5.0×10 −4 μmol/mm 3 were enclosed in the light-emitting tube.
[0165] The rated power of the discharge lamp (B) was 180 W, the rated voltage was 65 V, and the bulb wall loading value was 2.5 W/mm 2 .
EXAMPLES OF FIRST EMBODIMENT
Experimental Example 1
[0166] The discharge lamp (A) was fit by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 230 W (rated power value), the value of power to be supplied to the discharge lamp (A) was lowered from 230 W to 138 W (60% of the rated power value) at an average power change ratio shown in Table 1, then light radiated from the discharge lamp (A) was visually observed to inspect the conditions of occurrence of flicker, then if the occurrence of the flicker was not visually recognized, luminance of an irradiated surface was measured by using a measuring instrument such as illuminance meter, and evaluated as “very good” if a rate of variability of an illuminance value was within ±2%, “good” if the rate of variability exceeds the range of ±2% but within ±3%, and “bad” if the occurrence of the flicker was visually recognized.
[0167] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (A) was observed to inspect the conditions of occurrence of blackening, and evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0000] The results of the evaluation described above will be shown in Table 1 given below.
[0000]
TABLE 1
Power change ratio (W/s)
9.20
3.07
2.04
1.53
1.02
0.77
0.51
0.44
0.38
0.31
0.15
0.08
0.05
0.03
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
bad
good
good
good
very
very
very
very
very
very
very
good
good
occurrence of
good
good
good
good
good
good
good
flicker
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
blackening
Experimental Example 2
[0168] The discharge lamp (A) was it by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 184 W (80% of the rated power value), the value of power to be supplied to the discharge lamp (A) was lowered from 184 W to 115 W (50% of the rated power value) at an average power change ratio shown in Table 2, then light radiated from the discharge lamp (A) was visually observed to inspect the conditions of occurrence of flicker, then if the occurrence of the flicker was not visually recognized, luminance of an irradiated surface was measured by using a measuring instrument such as illuminance meter, and evaluated as “very good” if a rate of variability of the illuminance value was within ±2%, “good” if the rate of variability exceeds the range of ±2% but within ±3%, and “bad” if the occurrence of the flicker was visually recognized.
[0169] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (A) was observed to inspect the conditions of occurrence of blackening, and evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0000] The results of the evaluation described above will be shown in Table 2 given below.
[0000]
TABLE 2
Power change ratio (W/s)
6.90
2.30
1.97
1.15
0.77
0.58
0.38
0.33
0.29
0.23
0.12
0.06
0.04
0.02
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
bad
good
good
very
very
very
very
very
very
very
good
good
good
occurrence of
good
good
good
good
good
good
good
flicker
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
blackening
Experimental Example 3
[0170] The discharge lamp (A) was lit by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 184 W (80% of the rated power value), the value of power to be supplied to the discharge lamp (A) was lowered from 184 W to 138 W (60% of the rated power value) at an average power change ratio shown in Table 3 given below, then light radiated from the discharge lamp (A) was visually observed to inspect the conditions of occurrence of flicker, then if the occurrence of the flicker was not visually recognized, luminance of an irradiated surface was measured by using a measuring instrument such as illuminance meter, and evaluated as “very good” if a rate of variability of the illuminance value was within ±2%, “good” if the rate of variability exceeds the range of ±2% but within ±3%, and “bad” if the occurrence of the flicker was visually recognized.
[0171] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (A) was observed to inspect the conditions of occurrence of blackening and, evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0172] The results of the evaluation described above will be shown in Table 3 given below.
[0000]
TABLE 3
Power change ratio (W/s)
4.60
2.30
1.53
0.77
0.51
0.38
0.26
0.22
0.19
0.15
0.08
0.04
0.03
0.013
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
bad
good
very
very
very
very
very
very
very
very
good
good
good
occurrence of
good
good
good
good
good
good
good
good
flicker
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
blackening
Experimental Example 4
[0173] The discharge lamp (A) was lit by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 161 W (70% of the rated power value), the value of power to be supplied to the discharge lamp (A) was lowered from 184 W to 138 W (60% of the rated power value) at an average power change ratio shown in Table 4 given below, then light radiated from the discharge lamp (A) was visually observed to inspect the conditions of occurrence of flicker, then if the occurrence of the flicker was not visually recognized, luminance of an irradiated surface was measured by using a measuring instrument such as illuminance meter, and evaluated as “very good” if a rate of variability of the illuminance value was within ±2%, “good” if the rate of variability exceeds the range of ±2% but within ±3%, and “bad” if the occurrence of the flicker was visually recognized.
[0174] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (A) was observed to inspect the conditions of occurrence of blackening, and evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0175] The results of the evaluation described above will be shown in Table 4 given below.
[0000]
TABLE 4
Power change ratio (W/s)
2.30
1.53
0.77
0.38
0.26
0.19
0.13
0.10
0.10
0.08
0.04
0.02
0.013
0.006
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
good
very
very
very
very
very
very
very
very
good
good
good
good
occurrence of
good
good
good
good
good
good
good
good
flicker
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
bad
occurrence of
blackening
Experimental Example 5
[0176] The discharge lamp (B) was lit by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 180 W (rated power value), the value of power to be supplied to the discharge lamp (B) was lowered from 180 W to 108 W (60% of the rated power value) at an average power change ratio shown in Table 5 given below, then light radiated from the discharge lamp (B) was visually observed to inspect the conditions of occurrence of flicker, then if the occurrence of the flicker was not visually recognized, luminance of an irradiated surface was measured by using a measuring instrument such as illuminance meter, and evaluated as “very good” if a rate of variability of the illuminance value was within ±2%, “good” if the rate of variability exceeds the range of ±2% but within ±3%, and “bad” if the occurrence of the flicker was visually recognized.
[0177] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (B) was observed to inspect the conditions of occurrence of blackening, and evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0178] The results of the evaluation described above will be shown in Table 5 given below.
[0000]
TABLE 5
Power change ratio (W/s)
7.20
2.40
2.06
1.20
0.80
0.60
0.40
0.34
0.30
0.24
0.12
0.06
0.04
0.02
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
bad
good
good
good
very
very
very
very
very
very
very
good
good
occurrence of
good
good
good
good
good
good
good
flicker
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
blackening
[0179] As is apparent from the results in Table 1 to Table 5, it was found that when the power to be supplied to the discharge lamp was lowered under the condition that the average power change ratio became 0.01 to 2.1 W/s, the flicker did not occur and even when lowering of the power to be supplied to the discharge lamp under the condition described above was performed repeatedly, blackening of the light-emitting tube of the discharge lamp did not occur.
Experimental Example 6
[0180] The discharge lamp (A) was lit by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 138 W (60% of the rated power value), the value of power to be supplied to the discharge lamp (A) was increased from 138 W to 230 W (the rated power value) at an average power change ratio shown in Table 6 given below, then the light-emitting tube was visually observed to inspect the conditions of occurrence of cracks, and evaluated as “good” if no crack occurred in the light-emitting tube, and “bad” if the crack occurred in the light-emitting tube.
[0181] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (A) was observed to inspect the conditions of occurrence of blackening, and evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0182] The results of the evaluation described above will be shown in Table 6 given below.
[0000]
TABLE 6
Power change ratio (W/s)
9.20
3.07
2.04
1.53
1.02
0.77
0.51
0.44
0.38
0.31
0.15
0.08
0.05
0.03
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
bad
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
crack
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
blackening
Experimental Example 7
[0183] The discharge lamp (A) was it by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 115 W (50% of the rated power value), the value of power to be supplied to the discharge lamp (A) was increased from 115 W to 184 W (80% of the rated power value) at an average power change ratio shown in Table 7 given below, then the light-emitting tube was visually observed to inspect the conditions of occurrence of cracks, and evaluated as “good” if no crack occurred in the light-emitting tube, and “bad” if the crack occurred in the light-emitting tube.
[0184] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (A) was observed to inspect the conditions of occurrence of blackening, and evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0185] The results of the evaluation described above will be shown in Table 7 given below.
[0000]
TABLE 7
Power change ratio (W/s)
6.90
2.30
1.97
1.15
0.77
0.58
0.38
0.33
0.29
0.23
0.12
0.06
0.04
0.02
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
bad
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
crack
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
blackening
Experimental Example 8
[0186] The discharge lamp (A) was lit by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 138 W (60% of the rated power value), the value of power to be supplied to the discharge lamp (A) was increased from 138 W to 184 W (80% of the rated power value) at an average power change ratio shown in Table 8 given below, then the light-emitting tube was visually observed to inspect the conditions of occurrence of cracks, and evaluated as “good” if no crack occurred in the light-emitting tube, and “bad” if the crack occurred in the light-emitting tube.
[0187] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (A) was observed to inspect the conditions of occurrence of blackening, and evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0188] The results of the evaluation described above will be shown in Table 8 given below.
[0000]
TABLE 8
Power change ratio (W/s)
4.60
2.30
1.53
0.77
0.51
0.38
0.26
0.22
0.19
0.15
0.08
0.04
0.03
0.013
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
bad
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
crack
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
blackening
Experimental Example 9
[0189] The discharge lamp (A) was lit by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 138 W (60% of the rated power value), the value of power to be supplied to the discharge lamp (A) was increased from 138 W to 161 W (70% of the rated power value) at an average power change ratio shown in Table 9 given below, then the light-emitting tube was visually observed to inspect the conditions of occurrence of cracks, and evaluated as “good” if no crack occurred in the light-emitting tube, and “bad” if the crack occurred in the light-emitting tube.
[0190] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (A) was observed to inspect the conditions of occurrence of blackening, and evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0191] The results of the evaluation described above will be shown in Table 9 given below.
[0000]
TABLE 9
Power change ratio (W/s)
2.30
1.53
0.77
0.38
0.26
0.19
0.13
0.10
0.10
0.08
0.04
0.02
0.013
0.006
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
good
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
crack
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
bad
occurrence of
blackening
Experimental Example 10
[0192] The discharge lamp (B) was it by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) of 108 W (60% of the rated power value), the value of power to be supplied to the discharge lamp (B) was increased from 108 W to 180 W (the rated power value) at an average power change ratio shown in Table 10 given below, then the light-emitting tube was visually observed to inspect the conditions of occurrence of cracks, and evaluated as “good” if no crack occurred in the light-emitting tube, and “bad” if the crack occurred in the light-emitting tube. The result is shown in Table 10 given below.
[0193] The operation described above was performed repeatedly by five times, and then the light-emitting tube of the discharge lamp (B) was observed to inspect the conditions of occurrence of blackening, and evaluated as “good” if occurrence of blackening was not recognized, and “bad” if the occurrence of blackening was recognized.
[0194] The results of the evaluation described above will be shown in Table 10 given below.
[0000]
TABLE 10
Power change ratio (W/s)
7.20
2.40
2.06
1.20
0.80
0.60
0.40
0.34
0.30
0.24
0.12
0.06
0.04
0.02
Time of mode
10
30
45
60
90
120
180
210
240
300
600
1200
1800
3600
switching
term (s)
Condition of
bad
bad
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
crack
Condition of
good
good
good
good
good
good
good
good
good
good
good
good
good
good
occurrence of
blackening
[0195] As is apparent from the results in Table 6 to Table 10, it was found that when the power to be supplied to the discharge lamp was increased under the condition that the average power change ratio became 0.01 to 2.1 W/s, the cracks did not occur in the light-emitting tube, and even when lowering of the power to be supplied to the discharge lamp under the condition described above was performed repeatedly, blackening of the light-emitting tube of the discharge lamp did not occur.
EXAMPLES OF SECOND EMBODIMENT
Experimental Example 1
[0196] The discharge lamp (A) was lit by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) having a power of 75% of the rated power value (172.5 W), the power to be supplied to the discharge lamp (A) was lowered by 7% of the rated power (16.1 W) during four seconds (average power change ratio of 4.025 W/s), then the power change (the power change of lowering by 5% of the rated power (11.5 W) in the cycle of 5 seconds) to increase the power by 2% of the rated power (4.6 W) (average power change ratio of 4.6 W) in one second was repeated three times, whereby the power was lowered to 60% of the rated power value (132 W). A graph of change of the value of the power to be supplied to the discharge lamp in Experimental Example 1 is illustrated in FIG. 13 .
[0197] When light radiated from the discharge lamp (A) was visually observed in a state in which the power to be supplied to the discharge lamp (A) is maintained at 60% of the rated power value (132 W), occurrence of the flicker was not recognized.
Comparative Experimental Example 1
[0198] When the discharge lamp (A) was lit by supplying AC power (power in which one cycle of a lower frequency component in 90 Hz was inserted at every 37.5 cycle of a basic frequency component in 370 Hz) having a power of 75% of the rated power value (172.5 W), and the power to be supplied to the discharge lamp (A) was lowered by 15% of the rated power (34.5 W) during 30 seconds (average power change ratio of 2.3 W/s), whereby the power value was lowered to 60% of the rated power value (132 W), and when the light radiated from the discharge lamp (A) was observed in this state, occurrence of the flicker was recognized.
EXAMPLES OF THIRD EMBODIMENT
Experimental Example 1
[0199] When the discharge lamp (A) was lit for 200 hours by supplying a basic AC power and a superimposed power to the discharge lamp (A) under the condition given below, then when light radiated from the discharge lamp (A) after having lit the discharge lamp (A) for 200 hours was visually observed, occurrence of flicker was not recognized, and when the electrodes of the discharge lamp (A) were observed, no abnormality was recognized.
Basic AC Power
Current Frequency: 740 Hz
[0200] Power Value: 138 W (60% of the rated power value)
Superimposed Power
Current Frequency: 518 Hz
[0201] Superimposed Power Value: 35 W (sum of the basic AC power and the superimposed power was 173 W)
Supply Time: 2 minutes
Time Interval:
[0202] When the measured value of the lighting voltage when the superimposed power was supplied was equal to or lower than 80 V; 15 minutes
[0203] When the measured value of the lighting voltage when the superimposed power was supplied exceeded 80 V; 5 minutes
Experimental Example 2
[0204] When the discharge lamp (A) was lit for 200 hours by supplying a basic AC power and a superimposed power to the discharge lamp (A) under the condition given below, then when light radiated from the discharge lamp (A) after having lit the discharge lamp (A) for 200 hours was visually observed, occurrence of flicker was not recognized, and when the electrodes of the discharge lamp (A) were observed, no abnormality was recognized.
Basic AC Power
Current Frequency: 740 Hz
[0205] Power Value: 138 W (60% of the rated power value)
Superimposed Power
Current Frequency: 518 Hz
[0206] Superimposed Power Value: 35 W (sum of the basic AC power and the superimposed power was 173 W)
Supply Time: 2 minutes
Time Interval:
[0207] 15 minutes when the measured value of the lighting voltage when the superimposed power was supplied was lower than 80 V;
[0208] 10 minutes when the measured value of the lighting voltage when the superimposed power was supplied was equal to or larger than 80 V and lower than 100 V;
[0209] 15 minutes when the measured value of the lighting voltage when the superimposed power was supplied was equal to or higher than 100 V;
Experimental Example 3
[0210] When the discharge lamp (A) was lit for 200 hours by supplying the basic AC power and the superimposed power to the discharge lamp (A) under the condition given below, then when light radiated from the discharge lamp (A) after having lit the discharge lamp (A) for 200 hours was visually observed, occurrence of flicker was not recognized, and when the electrodes of the discharge lamp (A) were observed, no abnormality was recognized.
Basic AC Power
Current Frequency: 740 Hz
[0211] Power Value: 138 W (60% of the rated power value)
Superimposed Power
Current Frequency: 518 Hz
[0212] Superimposed Power Value: 35 W (sum of the basic AC power and the superimposed power was 173 W)
Time Interval:
[0213] 5 minutes when the measured value of the lighting voltage when the superimposed power was not supplied was lower than 75 V;
[0214] 15 minutes when the measured value of the lighting voltage when the superimposed power was not supplied was equal to or higher than 75 V;
[0000] Supply Time: 2 minutes
Experimental Example 4
[0215] When the discharge lamp (A) was lit for 200 hours by supplying the basic AC power and the superimposed power to the discharge lamp (A) under the condition given below, then when light radiated from the discharge lamp (A) after having lit the discharge lamp (A) for 200 hours was visually observed, occurrence of flicker was not recognized, and when the electrodes of the discharge lamp (A) were observed, no abnormality was recognized.
Basic AC Power
Current Frequency: 740 Hz
[0216] Power Value: 138 W (60% of the rated power value)
Superimposed Power
Current Frequency: 518 Hz
[0217] Superimposed Power Value: 35 W (sum of the basic AC power and the superimposed power was 173 W)
Supply Time:
[0218] 2 minutes when the measured value of the lighting voltage when the superimposed power was not supplied was lower than 70 V;
[0219] 4 minutes when the measured value of the lighting voltage when the superimposed power was not supplied was equal to or higher than 70 V;
[0000] Time Interval: 15 minutes
Experimental Example 5
[0220] When the discharge lamp (A) was lit for 200 hours by supplying a basic AC power and a superimposed power to the discharge lamp (A) under the condition given below, then when light radiated from the discharge lamp (A) after having lit the discharge lamp (A) for 200 hours was visually observed, occurrence of flicker was not recognized, and when the electrodes of the discharge lamp (A) were observed, no abnormality was recognized.
Basic AC Power
Current Frequency: 740 Hz
[0221] Power Value: 138 W (60% of the rated power value)
Superimposed Power
Current Frequency: 518 Hz
Superimposed Power Value:
[0222] When the measured value of the lighting voltage when the superimposed power was not supplied was lower than 70 V; 35 V (the sum of the basic AC power and the superimposed power was 173 W)
[0223] When the measured value of the lighting voltage when the superimposed power was not supplied exceeded 70 V; 92 V (the sum of the basic AC power and the superimposed power was 230 W)
[0000] Time Interval: 15 minutes
Supply Time: 2 minutes
Experimental Example 6
[0224] When the discharge lamp (A) was lit for 200 hours by supplying the basic AC power and the superimposed power to the discharge lamp (A) under the condition given below, then when light radiated from the discharge lamp (A) after having lit the discharge lamp (A) for 200 hours was visually observed, occurrence of flicker was not recognized, and when the electrodes of the discharge lamp (A) were observed, no abnormality was recognized.
Basic AC Power
Current Frequency: 740 Hz
[0225] Power Value: 138 W (60% of the rated power value)
Superimposed Power
Current Frequency: 518 Hz
Superimposed Power Value:
[0226] When the measured value of the lighting voltage when the superimposed power was not supplied was lower than 70 V; 35 V (the sum of the basic AC power and the superimposed power was 173 W)
[0227] When the measured value of the lighting voltage when the superimposed power was not supplied exceeded 70 V; 92 V (the sum of the basic AC power and the superimposed power was 230 W)
[0000] Time Interval: 15 minutes
Supply Time: 2 minutes
[0228] When the measured value of the lighting voltage when the superimposed power was not supplied was equal to or lower than 70 V; 3 minutes
[0229] When the measured value of the lighting voltage when the superimposed power was not supplied exceeded 70 V; 4 minutes
Experimental Example 7
[0230] When the discharge lamp (A) was lit for 200 hours by supplying a basic AC power and a superimposed power to the discharge lamp (A) under the condition given below, then when light radiated from the discharge lamp (A) after having lit the discharge lamp (A) for 200 hours was visually observed, occurrence of flicker was not recognized, and when the electrodes of the discharge lamp (A) were observed, no abnormality was recognized.
Basic AC Power
Current Frequency: 740 Hz
[0231] Power Value: 138 W (60% of the rated power value)
Superimposed Power
Current Frequency: 518 Hz
Superimposed Power Value: 35 V
[0232] Time Interval: 5 minutes at the shortest
Supply Time:
[0233] When the measured value of the lighting voltage when the superimposed power was not supplied was equal to or lower than 70 V; 0 minute
[0234] When the measured value of the lighting voltage when the superimposed power was not supplied exceeded 70 V; 2 minutes
Comparative Experimental Example 1
[0235] When light radiated from the discharge lamp (A) was visually observed after having lit the discharge lamp (A) for 200 hours by supplying AC power having a power value of 138 W (60% of the rated power value) in a current frequency of 740 Hz to the discharge lamp (A), occurrence of the flicker was recognized. Also, when the electrodes of the discharge lamp (A) were observed, wearing of the distal ends was recognized.
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A discharge lamp lighting device having a discharge lamp which has a pair of tungsten-made electrodes each having a protrusion formed at the tip thereof and an electric power feeding device which feeds an alternate current electric power to the discharge lamp, and is characterized in that the power feeding device has a function of switching between a first lighting mode in which a rated electric power is fed to the discharge lamp and a second lighting mode in which a lower electric power than the rated electric power is fed to the discharge lamp to light the discharge lamp, and therefore, can control electric power to be fed to the discharge lamp under such conditions that the average electric power change rate becomes 0.01-2.1 W/s during a mode switching period in which the switching from the first lighting mode into the second lighting mode is carried out.
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FIELD OF THE INVENTION
The present invention relates to flexible knitting pin, specifically circular knitting pin made from any material. Accordingly, a method to realize this invention is also provided.
BACKGROUND OF THE INVENTION
Conventional knitting pins are known to have metal shanks comprising of a nylon monofilament. The step formed at the junction, usually prepared from nylon monofilament is not smooth and therefore, the step catches the wool. This results in obstructed functioning of the knitting pin.
British patent GB876144 describes circular knitting pins of two relatively stiff metal end parts joined by a flexible connection made from a polymer plastics material. The flexible connecting tube is joined to the end parts by making axial bores in the undrawn end portions of the flexible connection made from a length of moulded or extruded plastic material, inserting the surface roughened spigots into the axial bores of the flexible connection while supplying sufficient heat to the junctions to cause the end parts and the connections to become fixed together and further elongating and reducing in cross-section the intermediate portion of the flexible connection until further elongation is strongly resisted.
SUMMARY OF THE INVENTION
The present invention relates to a flexible knitting pin consisting of two relatively stiff shanks ( 1 ) pointed at one end each, wherein said shanks are connected with each other by the other end with a flexible hollow connecting tube ( 2 ) comprising a joint (x); said joint between the stiff shanks ( 1 ) and the flexible hollow connecting tube ( 2 ) consisting of a metal sphere, hemisphere or cone positioned inside the hollow connecting tube ( 2 ) at a fixed position up against the end of the stiff shank.
The invention also provides a method for the manufacture of the flexible knitting pin.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a flexible knitting pin, specifically, circular knitting pin made from any material which enables smoother movement of stitches compared to the prior art and is easier to use. Also, the method of realizing this invention is relatively simple while maintaining the same functionality.
The knitting needle consists of two stiff shanks which are pointed at one end and suitably machined for attachment at the other. These shanks are then connected to each other using a flexible tube.
Thus the product consists of two stiff shanks, suitably pointed at one end each for knitting and connected from the other end using a flexible hollow tube. The joint between the stiff shanks and the flexible hollow connecting tube consists of a metal sphere, hemisphere or cone positioned inside the hollow connecting tube at a fixed position up against the end of the stiff shank. The joint between the stiff shanks and the hollow flexible connecting tube is extremely smooth to enable the individual stitches to slide over the connection without impairment and without the yarn snagging at the connection.
Another aspect of the invention is the method to realize this invention. The two stiff shanks of the knitting needle are made from plastic, metal or wood. The joint between the stiff shanks and the flexible hollow connecting tube is made by insertion of a metal sphere, hemisphere or cone into the hollow connecting material in such a way that the ball rests against the flat end of the stiff shank.
In a preferred embodiment, the shank is made of rose wood whereas the hollow flexible connecting tube is made of polyurethane. At one end of the shank is a ferrule made of brass which holds a ball head screw made of brass. To enable a smooth transition between the shank and the hollow flexible connecting material, an adaptor made of brass has been put at the joint.
In another embodiment of the invention, a method for the manufacture of the flexible knitting pin is provided. The shanks are manufactured by conventional manufacturing processes. The attachment to the flexible material is the substance of the invention. The flexible material used is in the form of a polyurethane tube. This polyurethane tube is connected to the rigid shanks using a brass adaptor, a ball headed screw and a threaded ferrule.
The joint itself is made up of brass parts which are attached to the wooden shank and to the polyurethane flexible tube. The brass ferrule and adaptor are manufactured by conventional turning processes using automatic lathes. They are fashioned from brass rod. These parts are then lacquered to prevent tarnishing. The tolerances are such that they meet the requirements of the product and the joint.
The ball headed screw is manufactured, out of brass rod, in a two stage operation. The first stage is a standard turning operation carried out on automatic lathes. The second stage is a stamping operation which is carried out on a special purpose machine built and designed by the applicant. After the second operation, the screw is lacquered to prevent tarnishing.
The rigid shanks are made with the back end (the end that is not pointed) finished to a diameter suited to the inner diameter of the brass adaptor. The head of the ball headed screw is inserted into the polyurethane tube.
The threaded portion of the ball headed screw is attached to the adaptor either directly, or using the ferrule (depending upon the size of knitting pin).
Adhesive is applied to the threaded portion to ensure that it locks tight. The adaptor carrying the ball headed screw, ferrule and attached to the polyurethane tube is then fastened to the shank with the use of an adhesive.
The above method results in an extremely smooth joint between the rigid shank and the flexible tube.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIG. 1 illustrates a perspective schematic view of the present invention. The two relatively stiff ends of the pin are denoted by 1 whereas the hollow flexible connecting tube between the two pins is denoted by 2 . The shank is made from rosewood whereas the hollow flexible connecting tube is made from polyurethane.
FIG. 2 illustrates one of the ends of the pin or shank which is pointed at one end and the other end forms a joint with the hollow flexible connecting tube.
FIG. 3 illustrates the junction between the shank and the hollow flexible connecting tube where the assembly of adaptor ( 3 ), ferrule ( 4 ) and the ball screw head ( 5 ) is shown in detail.
FIG. 4 illustrates the adaptor ( 3 ) which provides a smooth transition between the hollow flexible connecting material and the shank. The adaptor is made from brass.
FIG. 5 depicts the ferrule ( 4 ) which holds the ball head screw in place. The ferrule is made from brass.
FIG. 6 illustrates the ball head screw ( 5 ). The screw is made of brass.
Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention and it should be understood that this invention is not unduly limited to the illustrative embodiment set forth herein.
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A flexible knitting pin consisting of two relatively stiff shanks ( 1 ) pointed one end each, wherein said shanks ( 1 ) are connected with each other by the other end with a flexible hollow connecting material ( 2 ) comprising a joint; said joint between the stiff shanks ( 1 ) characterized in that it comprises a flexible hollow connecting material.
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RELATED APPLICATIONS
This application claims priority to U.S. Provisional Patent Application No. 60/876,339 filed Dec. 21, 2006, and entitled “Hitch Mounted Receiver Platform and Complementary Wagon” by Trish Crawford and Kent Crawford, which is incorporated herein by reference.
BACKGROUND
Individuals often need to move large amounts of gear or equipment to different locations. In many situations the gear or equipment cannot be easily be loaded into a vehicle. A possible solution is a cargo carrier attached to a car or truck, allowing a user to move equipment without loading the items into the vehicle. Such systems have limited mobility as they cannot be rolled. Gear must be carried from a vehicle to a destination. Another option is a toy or garden wagon which would allow individuals to roll but such wagons must be carried in a vehicle taking up valuable space. What is needed is a rolling device for transporting gear that may be attached externally to a vehicle.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent upon a reading of the specification and a study of the drawings.
SUMMARY
The following examples and aspects thereof are described and illustrated in conjunction with systems, tools, and methods that are meant to be exemplary and illustrative, not limiting in scope. In various examples, one or more of the above-described problems have been reduced or eliminated, while other examples are directed to other improvements.
This disclosure relates to hitch-based cargo and recreational gear carriers, specifically a removable wagon that can be lifted from a hitch insert & then rolled to a user's preferred destination.
One example is the Xtreme Wagon™ from Gear In Motion. Such a wagon allows individuals to move gear (recreational equipment) from a vehicle to events (such as soccer games and baseball games) in one simple step. Simply unhook the wagon from a car & roll it to an event.
A wagon may attach to a pivot hitch or a tilt hitch for assisted lifting of the wagon to a travel height. The wagon may be locked in place for travel. Advantageously, an individual is not required to bear the full weight of the wagon while lifting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an example of a system including a receiver platform and a complementary wagon.
FIG. 2 depicts an example of a system including a receiver platform and a complementary wagon with Z braces separated from the wagon.
FIG. 3 depicts an example of a system including a receiver platform and a complementary wagon connected together.
FIG. 4 depicts an example of a wagon.
FIG. 5 depicts an example of a flowchart of a method for using a wagon.
FIG. 6 depicts an example of a system including a wagon and a pivot hitch.
FIG. 7 depicts an example of a pivot hitch, disassembled.
FIG. 8 depicts an example of a system including a pivot hitch and a wagon base with wheels.
FIG. 9 depicts an example of a wagon.
FIG. 10 depicts an example of a flowchart of a method for using a wagon with a pivot hitch.
FIG. 11 depicts an example of a tilt hitch.
FIG. 12 depicts an example of a tilt hitch disassembled.
FIG. 13 depicts an example of a system including a wagon with a disassembled tilt hitch.
FIG. 14 depicts an example of a system including a wagon and a tilt hitch.
DETAILED DESCRIPTION
In the following description, several specific details are presented to provide a thorough understanding. One skilled in the relevant art will recognize, however, that the concepts and techniques disclosed herein can be practiced without one or more of the specific details, or in combination with other components, etc. In other instances, well-known implementations or operations are not shown or described in detail to avoid obscuring aspects of various examples disclosed herein.
FIG. 1 depicts an example of a system 100 including a receiver platform and a complementary wagon. FIG. 1 includes vehicle hitch receptacle 101 , hitching platform 102 , and wagon 103 .
The vehicle hitch receptacle 101 may be a “tow hitch,” or “tow point,” attached to a chassis of a vehicle for towing. The vehicle hitch receptacle 101 may be one of a class of tow hitches, for example, class I to 2000 lbs, class II 3500 lbs, class III to 5000 lbs, or IV 10,000 lbs.
The hitching platform 102 includes hole locking bolt 110 , hitch insert 111 , hitch insert receiver platform 112 , and locking pin 113 . The hitching platform 102 may be constructed from a strong load bearing material such as steel, high-strength light-weight alloy or other known or convenient material.
The hitch insert 111 may be an extended portion of the hitching platform 102 sufficiently load bearing to support the weight of the wagon 103 including loaded items. The hole locking bolt 110 , may be a hole though the hitch insert 111 , the positioning and the diameter of the hole may be as is known or convenient relative to the vehicle hitch receptacle 101 .
The hitch insert receiver platform 112 may be formed relative to the Z-bars 121 to slide into the Z-bars 121 of the wagon frame 124 . The hitch insert receiver platform 112 as depicted is formed of right angles so as to provide a fitted connection with the Z-bars 121 , however, any known or convenient form may be used. In a non-limiting example, the Z-bars 121 and hitch insert receiver platform 112 are formed of trapezoidal structure, a circular structure, or other known or convenient structure so as to allow for the wagon frame 124 and the hitch insert receiver platform 112 to slide together.
The locking pin 113 may be a rounded bar extending from the hitch insert receiver platform 112 paired with a hole in the loading stopper 123 . The shape of the locking pin 113 may be squared, rectangular, trapezoidal, circular, or other shape known or convenient so as to connect with loading stopper 123 to provide a secure locked position during travel. A clip or other device may be connected to locking pin 113 to secure the locking pin 113 to the loading stopper 123 .
The wagon 103 includes Z-bars 121 , guiding lip 122 , loading stopper 123 , and wagon frame 124 . The Z-bars 121 may be shaped relative to the hitch insert receiver platform 112 , and may be squared, rectangular, trapezoidal, circular, or other known or convenient shape allowing the Z-bars 121 to slide on the hitch insert receiver platform 112 to form a stable connection during transport of the wagon 103 . The guiding lip 122 extends as a portion of each Z bar ensuring the stable connection.
The frame of the wagon frame 124 may be fabricated from a light-weight high-strength material and formed in an aesthetically pleasing manner so as to produce an attractive means of transport of items while providing a stable manner of storage during transport. Bars of the wagon 103 may be formed to allow for points to tie items to, and to provide for straps and other devices for securing items within the wagon frame 124 . The wagon frame 124 may include cargo netting. The wagon frame 124 may include one or more pouches for placing items in.
FIG. 2 depicts an example of a system 200 including a receiver platform and a complementary wagon with Z braces separated from the wagon. FIG. 2 includes wagon 201 , Z braces 202 , and receiver platform 203 . In FIG. 2 the Z braces 202 are separated from the wagon 201 for visibility.
FIG. 3 depicts an example of a system 300 including a receiver platform and a complementary wagon connected together. FIG. 3 includes wagon 301 and receiver platform 302 . FIG. 3 depicts receiver platform and wagon 301 connected for transport by a vehicle.
FIG. 4 depicts an example of a wagon 400 . The depiction provides an alternative angle to view the wagon 400 .
FIG. 5 depicts an example of a flowchart 500 of a method for using a wagon. The method is organized as a sequence of modules in the flowchart 500 . However, it should be understood that these and modules associated with other methods described herein may be reordered for parallel execution or into different sequences of modules where is known or convenient.
In the example of FIG. 5 , the flowchart 500 starts at module 502 with filling a wagon with items. Such items may include any desirable gear, food, clothing, or other items needed for an event. In an non-limiting example, the event is a soccer game, and chairs, food, and drinks are loaded into the wagon.
In the example of FIG. 5 , the flowchart 500 continues to module 504 with securing the items to the wagon. Straps, rope, tape, cargo netting, or another manner of securing items to the wagon may be employed. In some methods, the wagon may be transported externally to a vehicle, and securing the items may prevent the items from being lost from the wagon during transport.
In the example of FIG. 5 , the flowchart 500 continues to module 506 with lifting the wagon off of the ground. With a receiver platform coupled to vehicle tow receptacle, it may be necessary to raise the wagon to a height sufficient to line Z-bars with a receiver platform.
In the example of FIG. 5 , the flowchart 500 continues to module 508 with sliding the wagon onto a receiver platform. After lining up Z-bars with a receiver platform, the wagon may be slid onto the Z-bars. The weight of the wagon and all items included therein may be supported by the receiver platform.
In the example of FIG. 5 , the flowchart 500 continues to module 510 with locking the wagon to the receiver platform. A locking pin may be passed through a loading stopper and fixed in place. In a non-limiting example a clip is passed through locking pin to prevent movement.
In the example of FIG. 5 , the flowchart 500 continues to module 512 with transporting the wagon to a destination. A vehicle having the wagon attached via the receiver platform may be driven to the destination.
In the example of FIG. 5 , the flowchart 500 continues to module 514 with unlocking the wagon from the receiver platform. A clip or other locking device may be disabled.
In the example of FIG. 5 , the flowchart 500 continues to module 516 with removing the wagon from the receiver platform. The wagon may be slid off of the receiving platform.
In the example of FIG. 5 , the flowchart 500 continues to module 518 with placing the wagon on the ground. An individual may place the wagon on its wheels to be rolled to an event.
In the example of FIG. 5 , the flowchart 500 continues to module 520 with rolling the wagon to an event. Advantageously, an individual may avoid carrying items to an event. Having transported the wagon to an event, the flowchart terminates.
FIG. 6 depicts an example of a system 600 including a wagon and a pivot hitch. The system 600 includes wagon base 601 and pivot hitch 602 . Each of the wagon base 601 and the pivot hitch 602 may be made of steel, a light-weight high-strength alloy, or any known or convenient material.
FIG. 7 depicts an example of a pivot hitch 700 , disassembled. FIG. 7 includes faceplate 701 , multi device attachment 702 , gas shock 703 , locking height adjuster 704 , hole locking bolt 705 , and hitch insert 706 .
The faceplate 701 includes rails having groves to slide into a faceplate adapter coupled to or part of a wagon base. The faceplate 701 may have a locking device to attach to the faceplate adapter of the wagon base.
The multi device attachment 702 may include one or more devices for attaching to items other than a wagon such as a bicycle rack, a ski rack, or other device for transporting items.
The gas shock 703 may be any device for applying pressure to support weight on the pivot arm during the lifting of a device attached to the faceplate 701 . The locking height adjuster 704 includes a plurality of holes for locking the pivot arm at various heights.
Hitch insert 706 may be an extended portion of the hitching platform 102 sufficiently load bearing to support the weight of a wagon including loaded items. The hitch insert 706 includes hole locking bolt 705 . The positioning and the diameter of the hole may be as is known or convenient relative to a vehicle hitch receptacle.
FIG. 8 depicts an example of a system 800 including a pivot hitch and a wagon base with wheels. FIG. 8 includes faceplate 802 , pivot hitch 803 , and faceplate adapter 804 . In operation, the faceplate adapter 804 may be slid onto and locked to the faceplate 802 . The faceplate 802 is coupled to the pivot hitch 803 . An individual may raise a loaded wagon off of the ground assisted by the pivot hitch 803 .
FIG. 9 depicts an example of a wagon 900 . The depiction provides an alternative view of the wagon.
FIG. 10 depicts an example of a flowchart 1000 of a method for using a wagon with a pivot hitch. The method is organized as a sequence of modules in the flowchart 1000 . However, it should be understood that these and modules associated with other methods described herein may be reordered for parallel execution or into different sequences of modules.
In the example of FIG. 10 , the flowchart 1000 starts at module 1002 with filling a wagon with items. Items may be chairs, food, drinks, or any items desirable.
In the example of FIG. 10 , the flowchart 1000 continues to module 1004 with securing the items to the wagon for travel while attached to a moving vehicle. Straps, cargo netting, rope or other devices may be used to secure the items to the wagon.
In the example of FIG. 10 , the flowchart 1000 continues to module 1006 with adjusting a pivot hitch to a desired height. Initially, the pivot hitch may be lowered to an optimal loading height.
In the example of FIG. 10 , the flowchart 1000 continues to module 1008 with attaching the wagon to a faceplate. Having lowered the pivot hitch to an optimal height, the wagon faceplate adapter maybe slid onto the faceplate of the pivot hitch securing the wagon to the faceplate.
In the example of FIG. 10 , the flowchart 1000 continues to module 1010 with locking the wagon to the faceplate. A clip, bolt, pin, or other device may be used to secure the wagon to the faceplate.
In the example of FIG. 10 , the flowchart 1000 continues to module 1012 with lifting the wagon off of the ground, assisted by the pivot hitch. A gas shock included in the pivot hitch may bear some weight of the loaded wagon. The wagon may be more easily lifted to an appropriate height.
In the example of FIG. 10 , the flowchart 1000 continues to module 1014 with raising the wagon to a travel height. The wagon may be raised to a travel height or other height as is desired.
In the example of FIG. 10 , the flowchart 1000 continues to module 1016 with locking a height adjuster in place. Having prepared the wagon for travel, the flowchart terminates.
FIG. 11 depicts an example of a tilt hitch 1100 . The depiction provides a view of the tilt hitch independent of other devices.
FIG. 12 depicts an example of a tilt hitch disassembled 1200 . FIG. 12 includes faceplate 1201 , hole locking bolt 1202 , tilt arm 1203 , and hitch 1204 .
Faceplate 1201 includes grooves for attachment to a faceplate adapter. The hole locking bolt 1202 is displayed as a cylindrical device, however, any shape could be used, e.g., square. The hole locking bolt 1202 may be passed through the faceplate 1201 so as to prevent movement of the faceplate 1201 relative to a faceplate adapter.
Hitch 1204 includes a tilt attachment 1205 receiving the tilt arm 1203 . The tilt attachment 1205 may be slanted so as to allow the tilt arm 1203 to tilt when attached to the hitch 1204 . The hitch 1204 also includes a hole for attachment to a hitch receptacle. The hitch receptacle may be bolted to the hitch 1204 to prevent movement of the hitch 1204 .
FIG. 13 depicts an example of a system 1300 including a wagon with a disassembled tilt hitch. The system includes faceplate 1301 , locking bolt 1302 , tilt arm 1303 , hitch 1304 , tilt attachment 1305 , faceplate adapter 1306 , and wagon 1307 .
In operation, the faceplate adapter 1306 of the wagon 1307 connects to the faceplate 1301 and is locked in place by the locking bolt 1302 . The faceplate 1301 is coupled to the tilt arm 1303 , and the tilt arm 1303 is coupled to the tilt attachment 1305 of the hitch 1304 . The hitch 1304 is connected to a hitch receptacle of a vehicle.
FIG. 14 depicts an example of a system 1400 including a wagon 1401 and a tilt hitch 1402 . The wagon 1401 is depicted tilted at an angle relative to the horizontal axis of the tilt hitch 1402 .
It will be appreciated to those skilled in the art that the preceding examples are not limiting in scope. It is intended that all permutations, enhancements, equivalents, and improvements thereto that are apparent to those skilled in the art upon a reading of the specification and a study of the drawings are included within the true spirit and scope of these teachings. It is therefore intended that the following appended claims include all such modifications, permutations, and equivalents as fall within the true spirit and scope of these teachings.
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A removable wagon may be attached to a hitch insert for transportation by a vehicle. After transport the wagon may be rolled by the user to a desired location. Devices for hitching the wagon to the vehicle are described.
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CROSS-REFERENCE
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/820,562 filed May 7, 2013, entitled “METHOD AND APPARATUS TO REMOTELY CONTROL INFORMATION TECHNOLOGY INFRASTRUCTURE” the contents of which are herein incorporated by reference in its entirety.
FIELD
[0002] The disclosure generally relates to enterprise cloud computing and more specifically to a seamless cloud across multiple clouds providing enterprises with quickly scalable, secure, multi-tenant automation.
BACKGROUND
[0003] Cloud computing is a model for enabling on-demand network access to a shared pool of configurable computing resources/service groups (e.g., networks, servers, storage, applications, and services) that can ideally be provisioned and released with minimal management effort or service provider interaction.
[0004] Software as a Service (SaaS) provides the user with the capability to use a service provider's applications running on a cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser or a program interface. The user does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities.
[0005] Infrastructure as a Service (IaaS) provides the user with the capability to provision processing, storage, networks, and other fundamental computing resources where the user is able to deploy and run arbitrary software, which can include operating systems and applications. The user does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, and deployed applications; and possibly limited control of select networking components (e.g., host firewalls).
[0006] Platform as a Service (PaaS) provides the user with the capability to deploy onto the cloud infrastructure user-created or acquired applications created using programming languages, libraries, services, and tools supported by the provider. The user does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly configuration settings for the application-hosting environment.
[0007] Cloud deployment may be Public, Private or Hybrid. A Public Cloud infrastructure is provisioned for open use by the general public. It may be owned, managed, and operated by a business, academic, or government organization. It exists on the premises of the cloud provider. A Private Cloud infrastructure is provisioned for exclusive use by a single organization comprising multiple users (e.g., business units). It may be owned, managed, and operated by the organization, a third party, or some combination of them, and it may exist on or off premises. A Hybrid Cloud infrastructure is provisioned for exclusive use by a single organization comprising multiple users (e.g., business units). It may be owned, managed, and operated by the organization, a third party, or some combination of them, and it may exist on or off premises.
[0008] The promise of enterprise cloud computing was supposed to lower capital and operating costs and increase flexibility for the Information Technology (IT) department. However lengthy delays, cost overruns, security concerns, and loss of budget control have plagued the IT department. Enterprise users must juggle multiple cloud setups and configurations, along with aligning public and private clouds to work together seamlessly. Turning up of cloud capacity (cloud stacks) can take months and many engineering hours to construct and maintain. High-dollar professional services are driving up the total cost of ownership dramatically. The current marketplace includes different ways of private cloud build-outs. Some build internally hosted private clouds while others emphasize Software-Defined Networking (SDN) controllers that relegate switches and routers to mere plumbing.
[0009] The cloud automation market breaks down into several types of vendors, ranging from IT operations management (ITOM) providers, limited by their complexity, to so-called fabric-based infrastructure vendors that lack breadth and depth in IT operations and service. To date, true value in enterprise cloud has remained elusive, just out of reach for most organizations. No vendor provides a complete Cloud Management Platform (CMP) solution.
[0010] Therefore there is a need for systems and methods that create a unified fabric on top of multiple clouds reducing costs and providing limitless agility.
SUMMARY OF THE INVENTION
[0011] Additional features and advantages of the disclosure will be set forth in the description which follows, and will become apparent from the description, or can be learned by practice of the herein disclosed principles by those skilled in the art. The features and advantages of the disclosure can be realized and obtained by means of the disclosed instrumentalities and combinations as set forth in detail herein. These and other features of the disclosure will become more fully apparent from the following description, or can be learned by the practice of the principles set forth herein.
[0012] A Cloud Management Platform is described for fully unified compute and virtualized software-based networking components empowering enterprises with quickly scalable, secure, multi-tenant automation across clouds of any type, for clients from any segment, across geographically dispersed data centers.
[0013] In one embodiment, systems and methods are described for classifying a data center resources into service groups; selecting a service group and assigning it to end users; monitoring the service groups; and controlling the service.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description of the principles 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 exemplary embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the principles herein are described and explained with additional specificity and detail through the use of the accompanying drawings in which:
[0015] FIG. 1 is a block diagram of an exemplary hardware configuration in accordance with the principles of the present invention;
[0016] FIG. 2 is a block diagram describing a tenancy configuration wherein the Enterprise hosts systems and methods within its own data center in accordance with the principles of the present invention;
[0017] FIG. 3 is a block diagram describing a super tenancy configuration wherein the Enterprise uses systems and methods hosted in a cloud computing service in accordance with the principles of the present invention;
[0018] FIG. 4 is a logical diagram of the Enterprise depicted in FIG. 1 in accordance with the principles of the present invention;
[0019] FIG. 5 illustrates a logical view that an Enterprise administrator and Enterprise user have of the uCloud Platform depicted in FIG. 1 in accordance with the principles of the present invention;
[0020] FIG. 6 illustrates a flow diagram of a service catalog classifying data center resources into service groups; selecting a service group and assigning it to end users; and,
[0021] FIG. 7 illustrates a flow diagram of mapping service group categories to user groups that have been given access to a given service group, in accordance with the principles of the present invention.
DETAILED DESCRIPTION
[0022] The FIGURES and text below, and the various embodiments used to describe the principles of the present invention are by way of illustration only and are not to be construed in any way to limit the scope of the invention. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims. A Person Having Ordinary Skill in the Art (PHOSITA) will readily recognize that the principles of the present invention maybe implemented in any type of suitably arranged device or system. Specifically, while the present invention is described with respect to use in cloud computing services and Enterprise hosting, a PHOSITA will readily recognize other types of networks and other applications without departing from the scope of the present invention.
[0023] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by a PHOSITA to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of the exemplary methods and materials are described herein.
[0024] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates, which may need to be independently confirmed.
[0025] Reference is now made to FIG. 1 that depicts a block diagram of an exemplary hardware configuration in accordance with the principles of the present invention. A uCloud Platform 100 combining self-service cloud orchestration with a Layer 2- and Layer 3-capable encrypted virtual network may be hosted by a cloud computing service such as but not limited to, Amazon Web Services or directly by an enterprise such as but not limited to, a service provider (e.g. Verizon or AT&T), provides a web interface 104 with a Virtual IP (VIP) address, a Rest API interface 106 with a Virtual IP (VIP), a RPM Repository Download Server and, a message bus 110 , and a vAppliance Download Manager 112 . Connections to and from web interface 104 , Rest API interface 106 , RPM Repository Download Server, message bus 110 , and vAppliance Download Manager 112 are preferably SSL secured. Interfaces 104 , 106 , 107 and 109 are preferably VeriSign certificate based with Extra Validation (EV), allowing for 128-bit encryption and third party validation for all communication on the interfaces. In addition to SSL encryption on Message BUS 110 , each message sent across on interface 107 to a Tenant environment is preferably encrypted with a Public/Private key pair thus allowing for extra security per Enterprise/Service Provider communication. The Public/Private key pair security per Tenant prevents accidental information leakage to be shared across other Tenants. Interfaces 108 and 110 are preferably SSL based (with self-signed) certificates with 128-bit encryption. In addition to communication interfaces, all Tenant passwords and Credit Card information stored are preferably encrypted.
[0026] Controller node 121 performs dispatched control, monitoring control and Xen Control. Dispatched control entails executing, or terminating, instructions received from the uCLoud Platform 100 . Xen control is the process of translating instructions received from uCLoud Platform 100 into a Xen Hypervisor API. Monitoring is performed by periodically by gathering management plane information data in an extended platform for memory, CPU, network, and storage utilizations. This information is gathered and then sent to the management plane. The extended platform comprises vAppliance instances that allow instantiation of Software Defined clouds. The management, control, and data planes in the tenant environment are contained within the extended platform. RPM Repository Download Server 108 downloads RPMs (packages of files that contain a programmatic installation guide for the resources contained) when initiated by Control node 121 . The message bus VIP 110 couples between the Enterprise 101 and the uCloud Platform 100 . A Software Defined Cloud (SDC) may comprise a plurality of Virtual Machines (vAppliances) such as, but not limited to a Bridge Router (BR-RTR, Router, Firewall, and DHCP-DNS (DDNS) across multiple virtual local area networks (VLANs) and potentially across data centers for scale, coupled through Compute node (C-N) pools (aka servers) 120 a - 120 n . The SDC represents a logical linking of select compute nodes (aka servers) within the enterprise cloud. Virtual Networks running on Software Defined Routers 122 and Demilitarized Zone (DMZ) Firewalls are referred to as vAppliances. All Software defined networking components are dynamic and automated, provisioned as needed by the business policies defined in the Service Catalogue by the Tenant Administrator.
[0027] The uCloud Platform 100 supports policy-based placement of vAppliances and compute nodes ( 120 a - 120 n ). The policies permit the Tenant Administrator to do auto or static placement thus facilitating creation of dedicated hardware environment Pools for Tenant's Virtual Machine networking deployment base.
[0028] The uCloud Platform 100 created SDC environment enables the Tenant Administrator to create lines of businesses or in other words, department groups with segregated networked space and service offerings. This facilitates Tenant departments like IT, Finance and development to all share the same SDC space but at the same time be isolated by networking and service offerings.
[0029] The uCloud Platform 100 supports deploying SDC vAppliances in redundant pair topologies. This allows for key virtual networking building block host nodes to be swapped out and new functional host nodes be inserted managed through uCloud Platform 100 . SDCs can be dedicated to data centers, thus two unique SDCs in different data centers can provide the Enterprise a disaster recovery scenario.
[0030] SDC vAppliances are used for the logical configuration of SDC's within a tenant's private cloud. A Router Node is a physical server, or node, in an tenant's private cloud that may be used to host certain vAppliances relating SDC networking. Such vAppliances may include the Router, DDNS, and BR-RTR (Bridge Router) vApplications that may be used to route internet traffic to and from an SDC, as well as establish logical boundaries for SDC accessibility. Two Router Nodes exist, an active Node (-A) and a standby Node (-S), used in the event that the active node experiences failure. The Firewall Nodes, also present in an active and standby pair, are used to filter internet traffic coming into an SDC. There is a singular vAppliance that uses the Firewall Node, that being the Firewall vAppliance. The vAppliances are configured through use of vAppliance templates, which are downloaded and stored by the tenant in the appliance store/Template store.
[0031] Reference is now made to FIG. 2 depicting a block diagram describing a tenancy configuration wherein the Enterprise hosts systems and methods within its own data center in accordance with the principles of the present invention. The uCloud platform 100 is hosted directly on an enterprise 200 which may be a Service Provider such as, but not limited to, Verizon FIOS or AT&T uVerse, which serves tenants A-n 202 , 204 and 206 , respectively. Alternatively, enterprise 200 may be an enterprise having subsidiaries or departments 202 , 204 and 206 that it chooses to keep segregated.
[0032] Reference is now made to FIG. 3 depicting a block diagram of a super tenancy configuration wherein the Enterprise uses systems and methods hosted in a cloud computing service 300 in accordance with the principles of the present invention. In this configuration, the uCloud platform is hosted by a cloud computing service 300 that services Enterprises 302 , 304 and 306 . It should be understood that more or less Enterprises could be serviced without departing from the scope of the invention. In the present example, Enterprise C 306 has sub tenants. Enterprise C 306 may be a service provider (e.g. Verizon FIOS or AT&T u-Verse) or an Enterprise having subsidiaries or departments that it chooses to keep segregated.
[0033] Reference is now made to FIG. 4 depicting a block diagram describing permutations of a Software Defined Cloud (SDC) in accordance with the principles of the present invention. The SDC can be of three types namely Routed 400 , Public Routed 402 and Public 404 . Routed and Routed Public SDC types 400 and 402 respectively are designed to be reachable through the Enterprise IP address space, with the caveat that the Enterprise IP address space cannot be in the same collision domain as these types of SDC IP network space. Furthermore, Routed and Public Routed SDC 400 and 402 respectively can re-use same IP network space without colliding with each other. The Public SDC 404 is Internet 406 facing only, it can have overlapping collision IP space with the Enterprise network. Public SDC 404 further provides Internet facing access only. SDC IP schema is automatically managed by the uCloud platform 100 and does not require Tenant Administrator intervention.
[0034] SDC Software Defined Firewalls 408 are of two/one type, Internet gateway (for DMZ use). The SDC vAppliances (e.g. Firewall 408 , Router 410 ) and compute nodes ( 120 a - 120 n ) provide a scalable Cloud deployment environment for the Enterprise. The scalability is achieved through round robin and dedicated hypervisor host pools. The host pool provisioning management is performed through uCloud Platform 100 . The uCloud Platform 100 manages dedicated pools for the compute nodes ( 120 a - 120 n ), it allows for fault isolation across the Tenant's Virtual Machine workload deployment base.
[0035] Referring back to FIG. 1 , an uCloud Platform administrator 102 A, an Enterprise administrator 102 B, and an Enterprise User 102 C without administrator privileges are depicted. To deploy uCloud platform 100 , Enterprise administrator 102 B grants uCloud Platform administrator 102 A information regarding the enterprise environment 101 and the hardware residing within it (e.g. compute nodes 120 a - n ). After this information is supplied, platform 100 creates a customized package that contains a Controller Node 121 designed for the Enterprise 101 . Enterprise administrator 102 B downloads and install Controller Node 121 into the Enterprise environment 101 . The uCloud Platform 100 then generates a series of tasks, and communicates these tasks indirectly with Controller Node 121 , via the internet 111 . The communication is preferably done indirectly so as to eliminate any potential for unauthorized access to the Enterprise's information. The process preferably requires uCloud platform 100 to leave the tasks in an online location, and the tasks are only accessible to the unique Controller Node 121 present in an Enterprise Environment 101 . Controller Node 121 then fulfills the tasks generated by uCloud platform 100 , and thus configures the compute 122 , network 123 , and storage 120 a - n capability of the Enterprise environment 101 .
[0036] Upon completion of the hardware configuration, uCloud platform 100 is deployed in the Enterprise environment 101 . The uCloud platform 100 monitors the Enterprise environment 101 and preferably communicates with Controller Node 121 indirectly. Enterprise administrator 102 B and Enterprise User 102 C use the online portal to access uCloud platform 100 and to operate their private cloud.
[0037] Software defined clouds (SDCs) are created within the uCloud platform 100 configured Enterprise 101 . Each SDC contains compute nodes that are logically linked to each other, as well as certain network and storage components (logical and physical) that create logical isolation for those compute nodes within the SDC. As discussed above, an enterprise 101 may create three types of SDC's: Routed 400 , Public Routed 402 , and Public 404 as depicted in FIG. 4 . The difference, as illustrated by FIG. 4 , is how each SDC is accessible to an Enterprise user 102 C.
[0038] Reference is now made to FIG. 5 that depicts a logical view of the uCloud Platform 100 that the Enterprise administrator 102 B and Enterprise user 102 C have in accordance with the principles of the present invention. Resources compute 502 , network 504 and storage 506 residing in a data center 507 are coupled to the service catalog 508 that classifies the resources into service groups 510 a - 510 n . A monitor 512 is coupled to the service catalog 508 and to a user 514 . User 514 is also coupled to service catalog 508 . Service catalog 508 is configured to designate various data center items (compute 502 , network 504 , and storage 506 ) as belonging to certain service groups 510 a - 510 n . The Service catalog 508 also maps the service groups to the appropriate User. Additionally, monitor 512 monitors and controls the service groups belonging to a specific User.
[0039] The service catalog 508 allows for a) the creation of User defined services: a service is a virtual application, or a category/group of virtual applications to be consumed by the Users or their environment, b) the creation of categories, c) the association of virtual appliances to categories, d) the entitlement of services to tenant administrator-defined User groups, and e) the Launch of services by Users through an app orchestrator. The service catalog 508 may then create service groups 510 a - 510 n . A service group is a classification of certain data center components e.g. compute Nodes, network Nodes, and storage Nodes.
[0040] Monitoring in FIG. 5 is done by periodically gathering management plane information data in the extended platform for memory, CPU, network, storage utilizations. This information is gathered and then sent to the management plane.
[0041] While this disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure, as defined by the following claims.
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Methods and apparatuses to remotely control information technology infrastructure are disclosed by classifying a data center device into a service group; selecting a service group and assigning to end-users; monitoring the service groups; and controlling the service. A platform has an input configured to receive service group classification and logic to control operational state of the data center devices attached to the service group.
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FIELD OF THE INVENTION
This invention relates to tape winding machines in general, and more particularly to splicing tape dispenser-applicators of the sort typically employed in tape winding machines.
BACKGROUND OF THE INVENTION
Tape winding machines are well known in the art. Such machines are used to transfer magnetic recording tape of the sort used in audio or video applications from the large supply reels typically prepared during tape manufacture onto the smaller hubs commonly employed in tape cassettes. See, for example, U.S. Pat Nos. 3,737,358, 4,061,286, 3,753,834, 3,637,153, 3,997,123 and 4,204,898. Such tape winding machines typically receive a pair of hubs connected by a leader tape, sever the leader tape into two sections, splice virgin or prerecorded magnetic tape to the leader tape section attached to a first of the hubs, wind a predetermined amount of magnetic tape onto that hub, and then splice the trailing end of the wound magnetic tape to the leader tape section attached to the second of the hubs. Machines currently exist for conducting this tape splicing and winding operation either before the hubs are mounted in a cassette or, alternatively, after the hubs have been mounted in a cassette.
Tape winding machines of the sort described above typically employ splicing tape dispenser-applicators to splice the supply and leader tapes together during the splicing operations described above. One preferred type of splicing tape dispenser-applicator now in common use, and described and illustrated in detail in U.S. Pat. No. 3,753,835, uses a reciprocating plunger assembly to cut a piece of splicing tape from a source of splicing tape and then press it against the two tapes to be spliced. The splicing tape then serves to effect the splice between the two subject tapes. The reciprocating plunger is made of metal and travels in a vertical guide channel which is defined by metal parts. A close sliding fit is required between the metal plunger and the vertical channel in order to assure that the plunger will be properly delivered to the point where the splice is to be made.
Unfortunately, over the course of repeated operation of the splicing tape dispenser-applicator, significant wearing of the various metal members occurs as a result of this metal-on-metal contact. One consequence of this wearing process is deterioration of the close sliding fit between the plunger and the guide channel. Since the close sliding fit is essential to satisfactory operation, the plunger and/or the metal members which define the vertical channel eventually have to be replaced. Such replacement tends to increase the "down-time" of the tape winding machine, thereby lowering the winding machine's productivity as well as increasing maintenance costs.
An even more important consequence of the aforementioned wearing process is that a fine metallic dust tends to build up within the vertical channel. This fine metallic dust may impede easy movement of the plunger within the vertical channel, thereby slowing operation of the splicing tape dispenser-applicator and necessitating frequent cleaning and lubrication of the plunger and the vertical channel. Such frequent cleaning and lubrication also tends to increase the "down-time" of the tape winding machine.
OBJECTS OF THE PRESENT INVENTION
Accordingly, the principal object of the present invention is to improve upon the splicing tape dispenser-applicator described and illustrated in U.S. Pat. No. 3,753,835 by solving the aforementioned wear problems associated with that dispenser-applicator's reciprocating plunger assembly.
SUMMARY OF THE INVENTION
This and other objects of the invention are achieved by providing a novel plunger assembly characterized by a plurality of low-friction bearing devices carried by the plunger. The bearing devices are disposed on the plunger so that they communicate with at least some of the metal parts which define the plunger's vertical channel, in order that the rubbing which occurs between the metal plunger and the metal parts which define the vertical channel will be significantly reduced when the plunger moves within the channel.
BRIEF DESCRIPTION OF THE DRAWINGS
Still other objects and features of the present invention are more fully disclosed or rendered obvious in the following detailed description of the preferred embodiment of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein:
FIG. 1 is a partial front view with portions broken away of a splicing tape dispenser-applicator which incorporates a novel plunger assembly constructed in accordance with the present invention;
FIG. 2 is an enlarged front view with portions broken away of the plunger assembly shown in FIG. 1;
FIG. 3 is a side view of the plunger assembly shown in FIG. 2; and
FIG. 4 is a partial sectional view taken along line 4--4 of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning first to FIG. 1, there is shown a splicing tape dispenser-applicator 2 which incorporates the preferred form of the novel plunger assembly. With the exception of the novel plunger assembly incorporated therein, splicing tape dispenser-applicator 2 is substantially the same as the splicing tape dispenser-applicator described and illustrated in U.S. Pat. No. 3,753,835. Therefore, for the sake of brevity, those portions of the splicing tape dispenser-applicator shown in FIG. 1 which are common to the splicing tape dispenser-applicator described and illustrated in U.S. Pat. No. 3,753,835 are dealt with herein only in such detail as is necessary to understand the present invention. Reference should be made directly to U.S. Pat. No. 3,753,835 for more detailed description on such common portions should the same be desired.
Splicing tape dispenser-applicator 2 generally comprises a carriage plate 4 on which is mounted a supply reel 6 of a splicing tape 8 which is coated on one side with a pressure-sensitive adhesive in order that it may serve to splice two subject tapes as hereinafter described. Also mounted to carriage plate 4 is a splicing tape feed wheel 10, a smaller tape feed wheel 12, a plunger assembly 41 which comprises the preferred embodiment of the present invention, and a double-acting fluid actuator 16.
Splicing tape supply reel 6 is rotatably mounted on a hub 18 which is affixed to and projects at a right angle from the plane of plate 4. Reel 6 is held in place on hub 18 by suitable means, e.g. a plastic cap 20 which is adapted to slip over and make a friction fit with the free end of hub 18. Splicing tape supply reel 6 is positioned on hub 18 so as to be in planar alignment with feed wheel 10 and feed roll 12, as will hereinafter be described in further detail.
Feed wheel 10 is mounted to a shaft 22 which extends through carriage plate 4 and forms part of a suitable one-way clutch mechanism (not shown). This clutch mechanism is adapted so that (1) when shaft 22 rotates in a clockwise direction (as seen from the viewpoint of FIG. 1), feed wheel 10 will also rotate in a clockwise direction, and (2) when shaft 22 rotates in a counterclockwise direction, feed wheel 10 will not rotate at all.
A spur gear 24 is disposed on shaft 22 between feed wheel 10 and carriage plate 4. Gear 24 is coupled to shaft 22 by means of the aforementioned clutch mechanism, and is securely attached to feed wheel 10, so that the spur gear and the feed wheel rotate as a single unit. Spur gear 24 contacts a finger 26 of a spring latch 28 mounted to carriage plate 4. This contact assures that spur gear 24 (and hence feed roll 10) can only rotate in a clockwise direction about shaft 22.
Splicing tape feed wheel 10 is provided with a circumferential groove in its periphery that is just wider than the width of the splicing tape 8, in order that the groove may serve as a seat for the splicing tape on the feed wheel. Wheel 10 is disposed on shaft 22 so that the wheel's peripheral groove sits in planar alignment with splicing tape supply reel 6. As a result, splicing tape 8 may be passed from supply reel 6 to the peripheral groove of feed wheel 10 without causing any deformation of the splicing tape.
Also affixed to carriage plate 4 is a short stub shaft 30. Splicing tape feed roll 12 is rotatably mounted on stub shaft 30, as is a second smaller spur gear 32. Gear 32 is securely connected to roll 12 so that the two members rotate on shaft 30 as a single unit. Feed roll 12 is provided with a circumferential groove in its periphery that is just wider than the width of the splicing tape 8, in order that the roll's peripheral groove may serve as a seat for the splicing tape on the feed roll. Feed roll 12 is mounted so that its peripheral groove sits in planar alignment with the peripheral groove of feed wheel 10 and also with tape supply reel 6. As a result, splicing tape 8 may be passed from the peripheral groove of feed wheel 10 to the peripheral groove of feed roll 12 without causing any deformation of the splicing tape.
Spur gear 32 meshes with the spur gear 24 disposed on the adjacent feed wheel 10. As a result, whenever feed wheel 10 moves in a clockwise direction, feed roll 12 will move in a counterclockwise direction, and whenever feed wheel 10 remains stationary (on account of its engagement with finger 26 of spring latch 28), feed roll 12 will also remain stationary.
A tape guide pin 36 is also affixed to carriage plate 4 below feed roll 12. Guide pin 36 has a peripheral groove 38 which has the same width as, and is in planar alignment with, the peripheral grooves in feed wheel 10 and feed roll 12.
A small block 40 is mounted to carriage plate 4 above stub shaft 30. Attached to block 40 is a plate 42 carrying a rubber pressure roller 44 on its bottom end. Plate 42 is positioned so that pressure roller 44 can ride within the peripheral groove of feed roll 12 and thereby serve to retain splicing tape in the peripheral groove in feed roll 12.
Also mounted to carriage plate 4 is a tape picker 46. Tape picker 46 is located between feed roll 12 and a vertical member 48 which defines one side of the plunger guide channel 58 and is formed with a flat surface 50 on its upper end. Picker 46 has a thickness slightly less than the width of the peripheral groove in feed roll 12, and is positioned so that it extends into that groove and its upper surface 50 lies tangent to the groove. A small horizontal gap 51 exists between the top surface 50 of picker 46 and the bottom surface 52 of block 40. As a result, a length of splicing tape winding around feed roll 12 will be lifted from the peripheral groove of that roll by picker 46 and guided into horizontal gap 51 towards vertical member 48. A pair of spaced guide pins 54 (only one of which is shown) on the bottom surface of block 40 serve to constrain splicing tape travelling in gap 51 against sideways travel. When dispenser-applicator 2 is mounted to a tape winding machine, a rotatable operating mechanism (not shown) is provided for rotating shaft 22 clockwise on command through a selected angle so as to advance a predetermined length of splicing tape into the channel 58 hereinafter described.
Also attached to carriage plate 4 are a pair of parallel plunger guide members 48 and 56 which are made of metal and define a vertical channel 58 for plunger assembly 14. Vertical member 48 has a horizontal slit 60 for admitting splicing tape travelling along the horizontal gap 51 into channel 58. Member 56 is formed with a vertically extending slot 62 (FIG. 4) for guiding plunger 100.
Vertical members 48 and 56 are connected at their top ends by a horizontally-extending block 64 which serves as a mount for double-acting fluid actuator 16. Actuator 16 is provided with hose fittings 66 (only one of which is shown) on its opposite ends for admitting air into the actuator. The actuator's piston rod 68 extends through an oversized bore (not shown) in block 64 down into channel 58 and its free end is affixed to plunger assembly 14.
Looking now at FIGS. 1-4, plunger assembly 14 comprises a metal plunger 100 having a front surface 102, a rear surface 104, a top surface 106, a bottom surface 108, and opposite side surfaces 110 and 112. A rib 114 projects from side surface 110, and a rib 116 projects from bottom surface 108.
Plunger 100 has a vertically extending slot 118 in its side surface 112 to accommodate a cutter member 120 (FIGS. 1 and 4). Cutter member 120 is disposed in slot 118 so that its outermost surface lies in planar alignment with side surface 112. Cutter member 120 is fastened to plunger 100 by means of a threaded fastener 122 which is received in a threaded bore 124 in plunger 100.
A plunger pad 126 is disposed on the bottom side of rib 116. Plunger pad 126 is coextensive with rib 116 and lies adjacent to the bottom end of cutter member 120 where it protrudes from slot 118. Plunger pad 126 is formed of a resilient material e.g. a soft rubber, and has one or more apertures 128 which communicate through a hole (not shown) in the bottom surface of plunger 100 with a chamber (not shown) formed in the interior of plunger 100 and having a vacuum opening 130 in front surface 102. A vacuum may be supplied to the bottom side of plunger pad 126. In practice, plunger opening 130 is connected by a hose (not shown) to a source of vacuum via a suitable control valve (not shown). Vacuum is applied to the plunger while the plunger is moving down in channel 58 and is removed when the plunger reaches the end of its downward stroke.
Rib 116 and plunger pad 126 are sized so that they have a width which is approximately the same as the width of splicing tape 8. A pair of guide pins 131 extend out of bottom surface 108 on either side of bottom rib 116 and plunger pad 126. Guide pins 131 extend slightly below the bottom surface of plunger pad 126.
In accordance with this invention, plunger 100 carries a plurality of low-friction bearing devices thereon. These bearing devices are in the form of cylindrical pads 132 which are disposed in bores 134 formed in side surface 110. Pads 132 extend out of bores 134 slightly beyond the plane of side surface 110, and are preferably bevelled into a rounded dome shape on their projecting ends. Pads 132 are formed from a relatively hard, low-friction material, e.g., Delrin®. Other low-friction plastic materials also may be used. While pads 132 are relatively hard, they are less hard than the metal of which the plunger and guide members 48 and 56 are made. The pads are sufficiently hard to keep the plunger from engaging the adjacent guide member or at least limit the engagement to a low pressure contact.
Plunger assembly 14 is disposed in channel 58, so that side surface 112 and cutter member 120 make a close sliding fit with guide member 48, rear surface 104 makes a close sliding fit with carriage plate 4, cylindrical pads 132 make a close sliding fit with guide member 56, and side rib 114 extends into and makes a close sliding fit with the portions of guide 56 which define vertical slot 62. At the same time, because cylindrical pads 132 project from the surface 110 of plunger 110, surface 110 of the plunger member makes a minimal, if any, contact with vertical member 56.
Plunger assembly 14 is reciprocated in channel 58 by actuator 16. Actuator 16, plunger assembly 14, and other parts of the splicing tape dispenser-applicator are sized and positioned relative to one another so that (a) when piston rod 68 is fully retracted, plunger assembly 14 is disposed in an upper position (FIG. 1) enabling splicing tape to enter channel 58 from horizontal gap 51 via slot 60 and to pass just below plunger pad 126 between guide pins 131, and (b) when piston rod 68 is fully extended plunger assembly 14 will be disposed so that plunger pad 126 will be located below the bottom end of channel 58.
When actuator 16 is stimulated so as to cause plunger assembly 15 to move downward in channel 58, the cutter member 120 will sever the splicing tape located below the plunger by a shearing action at the point where the tape comes through the slit 60 in vertical member 48. The severed portion of splicing tape 8, kept against pad 126 by the suction applied via aperture 128 for substantially the full down stroke of the plunger, is driven downwardly by the plunger assembly 14 into tight engagement with the abutting ends of the tapes being spliced, whereby the pressure-sensitive adhesive coating on splicing tape 8 causes the splicing tape to be attached to the two tapes. As or immediately after the splicing tape engages the tapes to be spliced, the vacuum force is removed from the plunger so as to release the splicing tape from pad 126. Thereafter, actuator 16 is caused to raise plunger assembly 14 back to its top at rest position in channel 58. The severed splicing tape remains in contact with the spliced tapes as plunger assembly 14 moves upwardly again to its original position. As the plunger 14 moves upwardly again, or after it has returned to its original elevated position, the associated mechanism on the tape winding machine causes shaft 22 to rotate again in a clockwise direction so as to advance an additional length of splicing tape 8 into channel 58 between vertical members 48 and 56 in anticipation of the next cycle of operation of the splicing tape dispenser-applicator 2 as above described.
ADVANTAGES OF THE PRESENT INVENTION
A splicing tape dispenser-applicator incorporating the present invention is far superior to a dispenser-applicator like the one described and illustrated in U.S. Pat. No. 3,753,835 since the novel low-friction bearing devices on the plunger reduce the wear which occurs between the plunger and the parts which define the plunger's guide channel. These low-friction devices carry the bearing load between the plunger and the adjacent channel-defining member. Since they protrude from the plunger, they prevent the plunger from engaging the adjacent guide member and thus reduce plunger wear and also wear of the adjacent guide member. Having at least two pads and spacing them apart facilitates guidance of the plunger and helps control the amount of friction since each pad may be relatively small. The lower the friction the faster the plunger may be reciprocated. As a result, maintenance and replacement costs are significantly reduced.
MODIFICATIONS OF THE PREFERRED EMBODIMENT
It is envisioned that one might modify the preferred embodiment of the present invention without departing from the scope of the present invention.
Thus, for example, the number and location of the low-friction bearing devices may be varied. Also low-friction bearing devices may be disposed on surfaces other than, or in addition to, surface 110. More particularly, one might provide bearing devices on side surface 112 of plunger 100 for sliding engagement with guide member 48 as the plunger reciprocates within its vertical channel.
Also it is possible to have bearing devices disposed in side rib 114 so as to bear against those portions of vertical member 56 which define vertical slot 62. The shape or form of the low-friction bearing devices also may be varied.
The present invention also may be utilized in other forms of splicer mechanisms which utilize a plunger mounted for reciprocating movement in a guide channel.
Still other changes within the scope of the present invention will be obvious to persons skilled in the art.
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An improved plunger assembly is provided for use in a splicing tape dispenser-applicator of the type which comprises a plunger and a guide channel in which the plunger reciprocates. The improved plunger assembly comprises a plurality of low-friction bearing devices carried by the plunger and arranged so as to slidably engage at least one member which defines the guide channel. The low-friction bearing devices reduce friction wearing of the plunger and the at least one channel-defining member.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to speaker enclosure devices, and relates specifically to an apparatus for re-radiating the sound emanating from a speaker enclosed and supported therein.
2. Description of the Prior Art
Presently known speaker enclosures include rigid walls, which absorb the sound radiating from the back of the speaker. Back of speaker sound is out of phase with respect to the sound radiating from the front of the speaker, and would, if not absorbed or modified, cancel at low frequencies, and interfere at high frequencies, with the sound radiating from the front of the speaker. Such presently known speaker enclosures can waste half of the sound being produced by the speaker, specifically the sound radiating from the back of the speaker.
Further, other presently known speaker enclosures, such as bass reflex systems, isolate the back of speaker sound wave, in low frequencies, by tuning the enclosed volume of air through a reflex opening to a resonant frequency. The indirect pressure emitted from the reflex opening undergoes a phase displacement such that it intensifies the front wave. Such enclosures are effective over less than half an octave around the resonant frequency, and provides little additional sound radiation beyond that provided by the enclosure without the reflex opening at other frequencies.
Sound, as recorded, includes two components, the "direct" sound, which reaches the microphones directly from the primary sound source, and "apparent" sound, which reaches the microphones from all other locations. The sound which is reproduced then includes such two components of the sound field, the direct and apparent sound, which originated from locations that are different from each other.
The apparent sound includes reverberant sound from the environment boundaries, and ambient sounds. The listener listens for reverberant and ambient sounds which occur at certain expected points in time, and excludes those which occur later or sooner. Apparent sound, by virtue of such difference in location with respect to direct sound, is not effectively reproduced by stereo speakers.
In professional sound environments, as a professional studio, the room is generally small. Rooms of small size have generally poor acoustic properties, as they do not provide sufficient reverberation time for the reverberant portion of the sound. To get longer reverberations time, a larger room is required, but large rooms are not convenient for operational reasons.
In home sound environments, a listening room is not designed with acoustics in mind, and such rooms also have generally poor acoustic properties.
Presently known speaker enclosures do not affect the boundaries of the sound listening environment and do not accurately reproduce and radiate apparent sound. Further, such enclosures "waste" the apparent sound that is available in the stereo program material.
SUMMARY OF THE INVENTION
In view of the above, an object of the invention is to provide an apparatus for re-radiating biphase sound radiating from a speaker enclosed and supported therein, for obtaining increased apparent sound from the speaker and for increasing the utilization of more of the sound generated by the speaker, specifically the back of speaker sound.
It is a further object to provide an improved speaker enclosure capable of radiating sound energy over a spectrum of from 50 Hz through 10 KHz with improved efficiency.
It is an additional object to provide an improved speaker enclosure that controls the shape of the sound radiation into the environment and which acts as a larger secondary sound source.
The above objects, as well as others, are provided for in the invention by means of an apparatus for re-radiating biphase sound radiating from a speaker enclosed and supported therein, which, when connected to receive a differential sound signal, enables the re-radiating sound to complement the direct sound radiating from stereo speakers.
The apparatus includes means for re-radiating the sound radiating from the back of the speaker to enable increased apparent sound to be obtained from the speaker and to prevent wasting the half of the sound energy that emanates from the back of the speaker.
The back speaker sound re-radiating means are comprised of a compliant material, such that at low frequencies the entire enclosure expands and contracts with the movement of the speaker diaphragm, responsive to volume expansion and contraction of the air enclosed in the means. The enclosure material is provided with portions that, at high frequencies, expand and contract locally in response to sound wavefront radiation from the speaker diaphragm. Such compliant material enables the enclosure to act as a radiator, producing a wavefront shape to conform to the shape of the entire means at low frequencies, and of the portions of the means at high frequencies such that the wavefront is in a desired shape to be radiated into the listening environment. For enhancing the perception of a more realistic sound, the apparatus further includes means for connecting the apparatus to a stereo source so as to obtain a difference signal to drive the apparatus to add phase information to the sound produced from the "left" and "right" stereo channels.
DESCRIPTION OF THE DRAWINGS
The invention is illustrated, by way of example thereof, in the accompanying drawings, wherein:
FIG. 1 is a perspective partly-broken view of a biphase sound re-radiating apparatus, pursuant to the invention;
FIG. 2 is a perspective partly-broken view of a cylindrically shaped speaker enclosure, in one embodiment of the invention;
FIG. 3 is a similar view of a spherically shaped speaker, in another embodiment of the invention;
FIG. 4 is a side fragmentary cross-sectional view of a transition region between a panel and a wavefront transmitting portion thereof;
FIG. 5 is a side elevational view of a speaker enclosure, with the sound radiation pattern in the low frequency range represented thereon;
FIG. 6 is a side elevational fragmentary view of a panel and wavefront transmitting portion, with the sound radiation pattern in the high frequency range represented thereon;
FIG. 7 is a schematic diagram of a plurality of speaker enclosures connected to a stereo amplifier and arranged in a small room along with conventional stereo speakers; and
FIG. 8 is a schematic view of a plurality of speaker enclosures connected to a stereo amplifier and arranged in a large room along with conventional stereo speakers.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred embodiment, the invention comprises, for example, a speaker enclosure 8 for re-radiating biphase sound radiating from a speaker A supported therein, adapted to enable the re-radiating sound to complement the direct sound radiating from right and left channel stereo speakers, as B, B', as illustrated in FIGS. 1-3, 7 and 8.
The apparatus 8, as illustrated in FIGS. 1-3, comprises means for re-radiating sound emanating from the back of the speaker, means for re-radiating sound emanating from the front of the speaker, means for screening sound re-radiating from the front and back of the speaker, and, in particular environment enhancing applications, means for connecting the apparatus to a stereo amplifier so as to obtain a difference signal. The apparatus 8 further includes means for supporting the front and back of speaker sound re-radiating means.
The back of speaker sound re-radiating means, as illustrated in FIGS. 1-6, is comprised of compliant material, which in a preferred embodiment is expanded polystyrene. A cylindrical apparatus is shown in FIG. 2 while a spherical version is illustrated in FIGS. 1 and 3. It has been observed that such material has unique mechanical properties causing it to function generally in a non-linear manner. At low frequencies it obeys basic mechanical laws, generally, such as expansion and contraction of enclosure volume. However, at high frequencies it has the ability to permit small areas of the material to vibrate without a large amount of loss to adjacent sections. At higher audio frequencies, where the wavelength approaches the cell size of the foam, the sound energy is not efficiently transmitted and may be substantially absorbed, thereby imposing an upper frequency limit on the satisfactory operating range of the device.
Such material is substantially efficient in transmitting energy in its thickness dimension, while changing the shape of the wavefront with very little energy loss in transmission. The material is effective over a substantial plurality of octaves between the low audio frequencies up to 10 KHz to re-radiate back of speaker sound.
The back of speaker sound re-radiating means comprises a plurality of panels, 10, 10', 10", connectable to the speaker so as to extend about and enclose the back of the speaker. Each panel includes a higher frequency wavefront transmitting portion, as 11, 11', and means for securing the plurality of panels 10, 10', 10" to each other.
As illustrated in FIG. 4, adjacent to each wavefront transmitting portion 11 is a thickness transition region 12 which includes a gradient transition from the thickness of the panel 10, to the thickness of the wavefront transmitting portion 11. Such wavefront transmitting portions 11 are thin enough to ensure their activity in the high frequency range.
The securing means preferably comprise an adhesive which is comprised of compliant elastomeric material. In a preferred embodiment, a silicone rubber adhesive is employed, such as General Electric RTV-108, which allows optimum expansion desired, and which has characteristic compliance over a wide range of temperatures, from -20° C. to 100° C.
The front speaker sound re-radiating means include the supporting means, and means for diffusing the front speaker sound, which are connectable to the speaker so as to extend about the side portion of the front of the speaker. The supporting means comprise a base 20 to which is attached a diffuser 21.
A sound screening means may include a decorative grille 30 which extends about the front and back speaker re-radiating means and visually conceals the panels 10, 10', 10".
The speaker is connected to a stereo amplifier with conductors. When used as a conventional speaker it may be coupled to a left or right output channel. If the apparatus is to be used to complement the right and left stereo channels, a connection is made to obtain a difference signal using wires 40, 40'.
A plurality of speakers according to the present invention may be arranged in a particular listening environment to provide maximum effectiveness. However, for effective high frequency sound higher than 10 KHz, separate tweeters should be provided. In a small room, the apparatuses may be arranged as illustrated in FIG. 7, specifically at the boundaries of the listening environment and between the speakers connected to the stereo channels, so as to provide a substantially uniform apparent sound field. The apparent or echo sound field apparatuses are connected to the positive terminals of the channels of the stereo amplifier by wires 40, 40' obtaining the difference signal therefrom to drive such apparatuses.
In a large room, the echo field apparatuses may be arranged as in FIG. 8, at the boundaries of the listening environment and between the stereo speakers B, B', so as to provide a uniform apparent sound field therein for the sound re-radiating therefrom. As in FIG. 7, the echo field apparatuses may be connected to the positive terminals of the channels of the stereo amplifier by wires 40, 40', so as to obtain the difference signal therefrom to provide the power necessary for driving the apparatuses. When the enclosures of the present invention are used as the primary right and left channel sound sources, additional high frequency speakers may be necessary to supply the audio frequencies above 10 KHz.
When the speakers according to the present invention are connected at low frequencies, below 1 kHz, the back of the speaker moves back and forth, creating air pressure changes therein, as illustrated in FIG. 5, which result in volume change responsive to air pressure excursions which are created by the movement the speaker diaphragm. The compliant material in the panels 10, 10', 10", the wavefront transmitting portions, as 11, 11', and the adhesive between the panels expands and contracts with air pressure changes to accommodate such volume expansion.
There is a high degree of efficiency of coupling of the sound wavefront to the impedance of the surrounding air in the listening environment, so that there is little waste of energy in such transmission.
The wavefront of re-radiated sound assumes the shape of the back of speaker sound re-radiating means, which can be contoured as desired for the specific objective in re-radiating the biphase and apparent sounds into the listening environment. The most desirable shape is believed to be spherical, which generates an omnidirectional uniform sound field. Other shapes, such as cylindrical or elliptical, can be useful for specific acoustic problems.
The expanded polystyrene material does not have measurable leakage of energy therefrom. Even with the small air leakage about the enclosure at the edges of the speaker, the entire system has an air leak rate of less than 1% of the period of the lowest frequency propagated, which may be considered substantially airtight. Virtually all sound energy generated from the speaker diaphragm is then radiated into the room.
At high or audio frequencies, as about 1 kHz, the high frequency wavefront transmitting portions 11, 11' become active and generate the high frequency wavefront pattern, as illustrated in FIG. 6, while the remaining portions of panels 10, 10', 10" and adhesive between the panel sections are relatively inactive. Each transmitting portion 11, 11' becomes a source of back of speaker sound and re-radiates the sound in a predetermined pattern consistent with the radiation pattern of the lower frequencies.
The front speaker sound re-radiating means function to reflect such front speaker sound off the base 20 and through the diffuser 21, such that such wavefront pattern "fits" into the phase and pattern of, and is re-radiated along with, the back of speaker sound. The grille 30 functions to protect the panels 10, 10', 10" and is transparent to the sound re-radiating from the front and back speaker portions.
Enclosures according to the present invention provide enhanced sound generation in the low through mid frequency range (up to 10 KHz) and, depending upon the sound source, can enable increased apparent sound to be obtained from the speakers or increased stereo right and left channel sound. The portion of the sound emanating from the speakers, specifically the back of speaker sound, is supplemented by the rephased front of speaker sound, thereby using more of the sound energy produced by the speaker. The compliant material is shaped to select the wavefront to be formed and radiated into the listening environment.
The apparatuses when driven by a difference signal accurately reproduce the biphase and apparent sound, and enable control of the acoustic boundaries of the listening environment by complementing the direct sound from stereo speakers.
An additional discovery of the present invention is the unique response of the expanded polystyrene material to the acoustic waves. The material appears to exhibit nonlinear mechanical properties and is especially suited to function as a broad band resonator.
Manufacturing techniques may permit molding of the enclosure in a single step. However, it is frequently simpler to form the panels and to join them later into the desired shape. Polystyrene is foamed in a mold, and the material best suited for the present application is fully foamed, with maximum open volume and lowest density.
As noted above, at the lower frequencies, the entire enclosure expands and contracts with the changes in air pressure produced by the excursions of the speaker diaphragm. At the higher frequencies, however, it is the thinner, small panel portions that are driven and resonate by the shorter, higher frequency acoustic waves. Frequencies above 10 KHz have a fractional wavelength that is short enough to approach the magnitude of very small groups of individual cells which then resonate, independently. At these higher frequencies, the expanded polystyrene foam material begins to absorb the acoustic energy.
In the audio frequency range up to 10 KHz, the material can be as high as 90% efficient in transmitting energy to the environment. The material resonates in areas that are related to the wavelength of the applied audio waves. As the waves become shorter, thinner sections of smaller area resonate and with appropriate design, a panel can act as a mechanical, crossover network.
Accordingly, a new use for expanded polystyrene has been disclosed. The new use is a substantially airtight speaker enclosure which is capable of reradiating sound energy applied to the interior of the enclosure in a predetermined pattern, determined by the shape of the enclosure. Spherical enclosures radiate spherical waves; and a cylindrical enclosure generates a substantially uniform, cylindrical pattern. By providing thinner sections of appropriate wall shape, radiators of acoustical energy at higher frequencies are achieved.
The preferred embodiment of the invention has been set forth above. It is to be understood, however, that variations may be made in such preferred embodiment, which variations may nevertheless be within the scope and spirit of the invention. The invention, therefore, is to be broadly construed within the scope and spirit of the claims herein.
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An improved speaker enclosure apparatus re-radiates biphase sound emanating from a speaker supported therein. When connected to receive a differential sound signal, the sound produced complements the direct sound radiating from "right" and "left" speakers. The enclosure is of compliant material, such that at low frequencies the entire enclosure expands and contracts with the expansion and contraction of the speaker diaphragm, responsive to volume expansion and contraction of the air enclosed in the enclosure. At high frequencies, only thinned portions of the enclosure expand and contract, responsive to the higher frequency sound wavefronts emanating from the speaker. The ability to mold the enclosure and the thinned portions provides a method of controlling the radiated wavefront to a desired shape to be propagated into the listening environment.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of Smart Grid loads and outages monitoring and management. More particularly, the invention relates to a method and system for creating cheap real time currents measurements, on power lines conductors.
BACKGROUND OF THE INVENTION
[0002] A smart grid delivers electricity from suppliers to customers using digital technology to save energy. This technology should also help to decrease peak demands of power, increase reliability and help to control voltage levels according to loads variations.
[0003] Smart grid (also called: Smart Electric Grid, Smart Power Grid, Intelligent Grid, IntelliGrid, FutureGrid, Intergrid, Intragrid etc.), need more information to enable to operate the control means like additional windings of transformers used to change voltage levels, circuit breakers used to connect/disconnect loads or make by-pass connections to increase power supply from under loaded lines to overloaded lines in the network and vise-versa when load decreases.
[0004] Generators in electric utilities, generate current at medium voltage to transmission transformers. They raise the voltage to very high levels. All over the length of the transmission long lines, power substations, with their distribution transformers, transform the voltage back into medium voltages supplied to the industrial areas and residential quarters in the cities.
[0005] Control teams and control equipment in utilities and substations, has good information and measured data about voltages and currents of both sides of the distribution transformers (incoming and out going lines. Each line includes usually 3 phases). But there is always a lack of information at the splitting points of transmission lines where there is more than one substation connected on the line. There is also a lack of information about the currents at the splitting points off the outgoing lines of the distribution transformers, feeding large number of secondary lines in urban areas.
[0006] The problem is even bigger at urban areas where low voltage lines supply electric power to small businesses and residents and many customers are connected to branches of the same power line, and they depends each other in their power consumption influencing their mutual voltage levels. The control systems cannot detect such local variations in current and voltage levels usually compensated by other branches of the line. They can see only the total current and voltage levels outgoing from the substations. In case that there is a big increase in current of a branch of a line, due to overloading with its voltage drop associated (and probably a temperature limits excess problem), when in the same time there is a small power consumption in neighborhood line branches, the control team can not detect any problem.
[0007] Another problem of the electric grid control is to detect rapidly an outage and its location. It is hard to know, especially in bad weather conditions in winter and/or at night that one or more lines are ruptured (fallen trees on electric lines, electric towers prostrated by inundation etc.).
[0008] The lack of information about the current distribution in local networks results in lack of control means. It happens very often that in such places power consumption is very high during some working hours of businesses, during the day, and very low at night. As a result there is a big drop in voltage during the working hours and too high voltage levels at night. Usually customers complains enable to detect such areas, but there is no means to control such phenomenon but a costly change in the network configuration, because the power control center usually has no on line information about these load changes to enable smart power back-up switching.
[0009] Actual smart grid developments enable to improve the current and voltage curves, to decrease instant peaks, improve cosine cp and eliminate some kinds of perturbations on power supply lines. These Smart Grid systems also regulate the network by decrease of power consumption at peak hours (with the aide of lower tariffs at other hours of the day, which is usually called dynamic pricing). Utilities encourage customers to install and use programmable thermostats with automated settings by offering dynamic pricing to shave peak loads. This rebate helps to change customer's behavior to approve demand response. Actual existing Smart Grid load control measurement means have only the indications of the out going currents from substations and the customer's current consumption where digital smart power meters are installed. But there is no information on currents distribution in the network between the end users and the outputs of the substations to enable real and better load control and voltage level regulation.
[0010] To address these problems and to provide more efficient load management and outage detection improved smart grids are required.
[0011] It is an object of the present invention to provide a system which is capable of providing information about the currents at the splitting points off the outgoing lines, especially of the distribution transformers, feeding large number of secondary lines in urban areas.
[0012] It is another object of the present invention to provide a system for rapidly detecting an outage and its location.
[0013] Other objects and advantages of the invention will become apparent as the description proceeds.
SUMMARY OF THE INVENTION
[0014] The present invention relates to a system for managing loads and detecting outages over electric power lines, which comprises: a) at least one wireless temperature sensor attached to bare conductors of said electric power line(s), at line junctions or lines' splitting points, for sensing temperatures generated by the currents flow in said conductors; and b) a Current Measurement Units (CMU) for wirelessly reading the temperature sensed by said sensor(s), thereby enabling cheap, rapid and easy RMS currents measurements on power lines at any voltage levels, by using temperature into current conversion formulas and tables. The wireless temperature sensor is a passive Temperature SAW RFID Tag, a SAW resonator, or any other type of wireless temperature sensor.
[0015] According to an embodiment of the invention, the system further comprises a reference temperature sensor for providing an ambient temperature indication to the CMU.
[0016] According to an embodiment of the invention, the CMU comprises the following modules: a) a reader and its corresponding antenna for endlessly scanning the temperatures sensor(s), thereby reading the temperatures generated by the line cables currents; b) analog-digital and digital-analog converters; c) a controller for converting the temperature readings into currents according to conversion tables adjusted experimentally in laboratory for the type, cross section and material of the conductors and the ambient temperature; and d) a power supply module.
[0017] The Power Supply may further comprises a Backup Unit for providing alternative DC Low Voltage for the CMU and its modules. For example, the backup unit may include a Lithium Battery type or equivalent, having backing, capability duration according to customers' requirements and regional climate conditions (e.g. 72 hours). Wherein, the Power Supply is powered by an Inductive Charger, a Photo Voltaic (PV) Solar Panel, connected directly to Low Voltage Power Line or any combination thereof.
[0018] According to an embodiment of the invention, the reader is selected from the group consisting of: temperature readers, RFID reader, SAW RFID reader or combination thereof.
[0019] According to one embodiment of the invention, the CMU further comprises a wireless transceiver and its corresponding antenna for transferring data regarding the temperatures readings to a remote control center. Wherein, the transmission mode of the wireless transceiver is adapted to the network's configuration and customers' requirements. Optionally, the network's configuration includes optical fibers in shield wires of transmission lines (or in phases' cables).
[0020] According an embodiment of the invention, the CMU further comprises a Hall Effect Sensor/Switch for enabling detection and localization of lines' outages. The CMU has a decoding reader(s) and the Hall Effect Switches to transmit the currents' reading results and outage burst messages correspondingly via a controller module and a transceiver module. Wherein, each CMU's geographic coordinates are stored in the computers of the Control Center or in the controller of said CMU to enable providing the reparation teams with the relevant GPS data enabling the localization of lines' outages and access instructions to the downstream electric tower where currents are still flowing in the splitting line, and the next downstream electric tower which is out of power to enable working teams fast reparation.
[0021] Preferably, each CMU has its unique ID number (for example, ID number uvwxyz 5 of CMU 93 in FIG. 9 ) associated to its n−1 line conductors (and one reference temperature conductor), referring to the number of the pole/tower on which said CMU is mounted, having its geographic coordinates stored in the Control Center's computers enabling to identify the CMU's transmitted temperatures and currents data, provided by the said CMU, and to provide to the working/reparation teams the GPS access instructions to the downstream electric tower equipped with a CMU where currents are still flowing in one or more of the splitting lines, and the next downstream electric tower equipped with a CMU, which is out of power to enable working teams fast localization and reparation.
[0022] According to an embodiment of the present invention, the system further comprises a Data Collection Scanning transceiver or plurality of Data Collection Scanning transceivers connected to a SCADA, SPC, HMI programs completing a full Manufacturing Execution System (MES) on a high speed quad-core CPU to provide for the operators at the Loading Control Monitors, a real time loads management information and outages detection indications and localization. Wherein, the data collecting scanning transceivers are possibly placed in the substations to collect data from CMUs accumulated by cascade methods to save scanning time and been sent in batch, current upstream, to the substations and then in batches to a central or main Data Collection Scanning transceiver.
[0023] According to an embodiment of the present invention, the system further comprises an Interface Generator for enabling to work in harmony with the Other Customers' Programs and Systems.
[0024] According to an embodiment of the invention, the temperature sensor is attached to the bare cable by any thermal conduction method. Wherein, the temperature sensor is attached to the bare cable by being bonded in a niche under a special clip made of metallic material adapted to the material of the line conductor in order to prevent corrosion (usually aluminum and cuprum alloys), with a special tooth and slot to assure good press of the clip by pressure and good heat transmission by using a heat conducting epoxy or any other appropriate heat sink compound; and wherein the pressed and bonded clip is or may have a slot for the antenna of the temperature sensor, and/or may be covered by a UV protected and temperature insulating heat shrinking plastic, forming a bonded jacket with some overlapping on the bare conductor out of the clip area and one or more layers around the conductor, to assure good protection against fast change in weather conditions like rain or wind blows which could introduce errors in temperature readings.
[0025] According to one embodiment of the invention, the system further comprises one or more Integrated Thermal Cameras connected to the CMU for providing temporarily or as a final solution, the cables' temperatures (especially for transmission lines where one should wait until the maintenance or reparation works, to enable tags attachment at such high voltage levels or where cables elongation indications/alarms are also desired).
[0026] The present invention, further relates to a method for managing loads and detecting outages over electric power lines, comprising the step of: a) providing at least one wireless temperature sensor attached to bare conductors of said electric power line(s), at line junctions or lines' splitting points, for sensing temperature according to the current flow in said conductors; and b) wirelessly reading said sensed temperature by CMU while using temperature into current conversion formulas and tables. Wherein reading the generated temperature by the CMU comprising the steps of: a) endlessly scanning the temperature sensor(s) for reading the generated temperature by CMU's Reader; b) converting said read generated temperature from analog signal into digital data; and c) converting the temperature readings into currents according to conversion tables adjusted experimentally in laboratory for the type, cross section and material of the conductors and the ambient temperature.
[0027] According to an embodiment of the invention, the CMU further comprises transferring data regarding the temperature reading to a remote control center via a wireless transceiver and its corresponding geographic coordinates and detecting lines' outages by using a Hall Effect Sensor/Switch and generating burst outage messages. Wherein the burst outage messages are directed to an Outage Control Monitor at the Control Center, thereby enabling the operators to read the messages and get the GPS information about the location and access to the outage relevant tower(s) or pole(s) where said outage occur, and to get other relevant screen windows, to enable better operation decisions.
[0028] According to an embodiment of the invention, the geographic coordinates of each CMU reporting an outage are stored in the computers of the Control Center to enable the localization of lines' outages and GPS access instructions to the downstream electric tower where currents are still flowing in one or more of the splitting lines, and the next downstream electric tower which is out of power to enable working teams fast localization and reparation by using a GPS device.
[0029] The data transmitted by the CMU is collected in a computerized center having a MES program including a SCADA, SPC and HMI, for analyzing the data and making the relevant comparisons (according to the grid management requirements), of currents measured in real time, to currents measured in previous same hours of the day at previous working days or not working days or same kind power consumption days, and so on, to give to the controllers at the control center according to their requirements the relevant information about significant deviations from normal rating currents on their loading control monitors. Wherein the MES program comprising the steps of: a) enabling the system to communicate and coordinate with other customer's programs and systems, for data exchange using an Interface Generator; and b) enabling to change formats and data displayed on the Monitors' screens and for displaying also information from said other customer's programs and systems using a Display Generator.
[0030] According to an embodiment of the invention, the remote control center is able by summation of currents of each splitting point downstream, comparing to the currents of each phase at the previous splitting point upstream, to detect any leakage or pirate connection where such phenomenon exists.
[0031] The present invention is a Smart Grid system for loads and outages monitoring and management by using Supervisory Control and Data Acquisition (SCADA), SPC, MES, HMI and large number of current measuring and sensing units spread all over the electricity supply network. More particularly, the invention relates to a method and system for creating cheap real time currents measurements, on power lines conductors, by using a generic technology of wireless temperature sensors, such as passive SAW RFID TAGS, attached to the lines conductors of electricity networks at any voltage levels. In some cases imager devices, such as cameras could be introduced. Additionally this invention provides a cheap system and method to enable fast detection and localization of lines outages and temperature excess alarms.
[0032] According to one aspect of the present invention, there is provided a large number of cheap Current Measuring Units (CMUs), based on generic technology of SAW RFID tags, attached to the electric lines cables, possibly at each splitting point/junction of the power lines. Thermal cameras can provide a temporary/permanent solution for transmission power lines, enabling by matrix image processing to measure the lines cables' temperatures/currents including cables elongation which is often a very important indication for electric transmission corporations.
[0033] Fast scanning of the real time transmitted information from the CMUs, by a SCADA system, brings to the Manufacturing Execution System (MES), the information. The information is analyzed by the Statistical Process Control (SPC), and presented by using a Human Machine Interface (HMI), on the Control Monitors of the Electric Power Control Center. The fast scanning, supported by high performance quad-core computers, enable to scan each minute or less, the output information from the CMUs, transmitting the information from up to millions of SAW RFID tags. The temperature of each power line cable, above the ambient temperature, measured by its tag is transformed to RMS current and compared according to the Grid Management requirements to the average current at the same hour the working day before and/or compared to the average current at the same hour in the last week and/or any other comparison required (taking in consideration weekends, Holidays etc). In case of deviation from normal power consumption tolerances, the system will provide indications to enable the control intervention, manually or automatically.
[0034] According to another aspect of the present invention, using digital hall-effect switches, at the Current Measuring Units, will provide outage indications, by transmitting burst alarm signals. These outage fast detection indications will be directed to a special Outages Control Monitors at the Power Control Center. According to the SAW RFID tags associated to the specific current measuring unit, the operator will be able to click on the message and see the GPS coordinates of the electric tower and the map associated to the relevant outage reporting by this current measuring unit (the most upper CMU in the downstream line which is out of service). This will enable to send a working team for reparation, if necessary.
[0035] The Current Measuring Units are low power consuming units and will be powered inductively or by solar panel with a backup unit. In urban areas and low voltage networks it is possible to connect the measurement units directly to the network similarly to the streets lighting system (with a backup, like lithium battery or equivalent).
[0036] According to another aspect of the present invention, a transmission unit comprising a wireless transmitter, will transmit the results of the transformation of all the temperatures measured by the SAW RFID tags of each phase and cable into currents, via communication relays or directly to the scanning system at the Power Control Center. The system will provide also alarms associated to temperature excess on power lines, including the geographic positioning and recommendations to operators at the control center according to the MES analysis.
[0037] The MES program is a tool for the operators. It is a full internet/intranet interactive network management system (including a full maintenance system), with a secured access by personal user name and password enabling access from anywhere. Each manager and operator can get access to the relevant information he need (the system possess a screens generator user friendly). Such access enables to create easily a regional Control Center. Interface generator enables to couple the system to other operating systems of the network, including the ERP system of the power supply organization.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] In the drawings:
[0039] FIG. 1A schematically illustrates a typical pole with two splitting three phase lines, according to the prior art;
[0040] FIG. 1B schematically illustrates the typical pole provided with a smart grid system, according to an embodiment of the present invention;
[0041] FIG. 2 is a schematic description of a SAW RFID TAG (chip), reflecting the RF waves transmitted by the Reader and modulated as Surface Acoustic Waves pulses by the special configuration of the Wave Reflectors influenced also by temperature expansion;
[0042] FIG. 3 shows the SAW RFID TAGS attachment configuration and its accessories;
[0043] FIG. 4 is a Metallic Tag Attachment Clip before pressing with a special insulated pressing tool in order to connect it to the bare lines conductors;
[0044] FIG. 5 is a bloc diagram of the Current Measuring Unit, including a SAW RFID TAG and a Reference Tag;
[0045] FIG. 6 is a schema of a Digital Hall Effect Switch, used as fast outage detection sensor;
[0046] FIG. 7 is a 3 phase current's figures curves used to explain the Hall
[0047] Effect Switch operation as a line outage detector;
[0048] FIG. 8 shows the options to supply power to the Power Supply unit, by
[0049] Inductive Charger or Solar Panel or by direct connection in low voltage power lines; and
[0050] FIG. 9 is a bloc diagram of the whole system with the Currents Measuring Units (CMUs), a Data Transmission System, a Computerized Data Analyzing center with operators' Control Monitors.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0051] FIG. 1A schematically illustrates a typical concrete tubular electric lines pole 10 directly set in the earth 25 , carrying two cross arms beams 11 , 12 , supporting with pin type insulators 13 , an incoming three phase line conductors 14 (i.e., distribution line, supply transformer side) and two outgoing splitting lines 15 , 16 . Usually, such pole 10 may also comprises a safety lattice-type fence 20 for preventing the climbing of unauthorized persons on the pole. This embodiment shows an example of a concrete tubular pole with two splitting lines. Of course, the pole can be any type of tubular or other type of poles or electric lines towers carrying more than two cross arms beams or two outgoing splitting lines.
[0052] FIG. 1B schematically the typical pole 10 equipped with a smart grid system according to an embodiment of the present invention. The smart grid system comprises a Current Measuring Unit (CMU) 19 and one or more passive temperature Surface Acoustic Wave Radio Frequency Identification (SAW RFID) Tag (such as SAW RFID Tags 17 , 18 ), wherein the two outgoing splitting lines 15 , 16 carry on each bare conductor the SAW RFID Tags 17 , 18 respectively. The SAW RFID Tags 17 , 18 serve as temperature sensors of the power lines cables.
[0053] Referring now to FIG. 5 , according to one embodiment of the invention, CMU 19 is a low power unit which comprises a Radio Frequency ID (RFID) transceiver 26 and its corresponding antenna 22 , Analog-to-Digital Conversion and Digital-to-Analog Conversion (ADC/DAC) 51 , a controller 52 such as Programmable Logic Controller (PLC), an internal wireless transceiver 53 and its corresponding antenna 24 , Hall effect sensor 54 (optional), and a power supply unit 55 . According to an embodiment of the present invention, the power supply 55 is a low power unit and such embodiment is described in further details with respect to FIG. 8 .
[0054] In this embodiment, the CMU 19 is mounted below (e.g., 2-3 meters) the cross arms beams 11 , 12 and above the safety lattice-type fence 20 . CMU 19 can be powered by any suitable type(s) of power supply, such as inductive, solar, direct connection power supply with back up unit, etc. a PV solar panel 21 which provides energy to the low power CMU 19 . CMU 19 communicates by the RF transceiver via its antenna 22 with the SAW RFID tags 17 , 18 on the phase conductors. Optionally, the system comprises an additional SAW RFID tag 23 (which mounted on short segment of a cable of the same type and cross section as that of the phase conductors). SAW RFID tag 23 serves for an ambient temperature reference measurement.
[0055] According to one embodiment of the invention, the CMU 19 contains an outage detection unit. Additionally, the system may comprise one or more thermal camera (not shown), which, for example, can be mounted on the pole 10 under each splitting line(s) 15 , 16 . Alternatively, the thermal camera could be also used for the cables temperature sensing instead of the SAW RFID tags 17 , 18 (especially in transmission power lines).
[0056] The Tag's temperatures above ambient, are transformed into RMS currents levels, by the controller 52 , feed with an appropriate calibrated transformation table for the specific line cables 15 , 16 used at this specific pole 10 . The internal wireless transceiver 53 , via its antenna 24 transmits the data to a scanning transceiver 97 ( FIG. 9 ) of a remote Control Center 99 ( FIG. 9 ). The data transmission could be of any kind (e.g., this can be chosen by consulting the customer). Actually many shield wires on transmission lines may include optical fibers (OPGW), used for communication and control of power systems. Other options are by using a telemetry module with GSM/GPRS, RS485, RF, TCP, IP etc. Data transmission could use local communication relays realizing connection to main data transmission channels. For each ambient temperature there is a specific transformation table indicating the current for each measured temperature in the currents rating range, wherein the number of tables may varied according the intervals of ambient temperature required by the customer in his rating range (e.g., each 0.5° C. in the range of ambient temperatures between −10° C. up to +40° C.). Wherein each stored transformation table correspond to a specific ambient temperature and starts from that specific ambient temperature up to the maximum rating temperature indicating the current associated to each measured temperature (e.g., for ambient temperature of +25° C. we shall use the transformation table starting from +25° C. up to +150° C. indicating, for example, in case the measured temperature is +95° C. the RMS current is 121 Amp).
[0057] FIG. 2 is a schematic description of the SAW RFID Tag 17 (but is similar also to SAW RFID Tags 18 and 23 of FIG. 1 ), and its communication with RFID reader 26 of CMU 19 and its corresponding antenna 22 via radio waves (a detailed description of CMU 19 is shown with respect to FIG. 5 ). The Surface Acoustic Waves (SAW) phenomena and the SAW RFID Tag way of operation are described in further details herein after with respect to the system of the present invention.
Surface Acoustic Waves Phenomena and its Implementation in the Present Invention
[0058] Surface Acoustic Waves (SAW) were first explained in 1885 by Lord Rayleigh, who described the surface acoustic mode of propagation and predicted its properties in his classic paper. Named after their discoverer, Rayleigh waves have a longitudinal and a vertical shear component that can couple with any media in contact with the surface. This coupling strongly affects the amplitude and velocity of the wave, allowing SAW sensors to directly sense mass and mechanical properties.
[0059] Virtually all acoustic wave devices and sensors use a piezoelectric material to generate the acoustic wave. Piezoelectricity was discovered by Brothers Pierre and Paul-Jacques Curie in 1880, received its name in 1881 from Wilhelm Hankel, and remained largely a curiosity until 1921, when Walter Cady discovered the quartz resonator for stabilizing electronic oscillators. Piezoelectricity refers to the production of electrical charges by the imposition of mechanical stress. The phenomenon is reciprocal. Applying an appropriate electrical field to a piezoelectric material creates a mechanical stress. Piezoelectric acoustic wave sensors apply an oscillating electric field to create a mechanical wave, which propagates through the substrate and is then converted back to an electric field for measurement.
[0060] Among the piezoelectric substrate materials that can be used for acoustic wave sensors and devices, the most common are quartz (SiO2), lithium tantalate (LiTaO3), and, to a lesser degree, lithium niobate (LiNbO3). Each has specific advantages and disadvantages, which include cost, temperature dependence, attenuation, and propagation velocity. An interesting property of quartz is that it is possible to select the temperature dependence of the material by the cut angle and the wave propagation direction. With proper selection, the first order temperature effect can be minimized. An acoustic wave temperature sensor may be designed by maximizing this effect.
[0061] The sensors are made by a photolithographic process. Manufacturing begins by carefully polishing and cleaning the piezoelectric substrate.
[0062] Metal, usually aluminum, is then deposited uniformly onto the substrate. The device is spin-coated with a photoresist and baked to harden it. It is then exposed to UV light through a mask with opaque areas corresponding to the areas to be metalized on the final device. The exposed areas undergo a chemical change that allows them to be removed with a developing solution. Finally, the remaining photoresist is removed. The pattern of metal remaining on the device is called an interdigital transducer, or IDT. By changing the length, width, position, and thickness of the IDT, the performance of the sensor can be maximized.
[0063] Acoustic waves are distinguished primarily by their velocities and displacement directions; many combinations are possible, depending on the material and boundary conditions. The IDT of each sensor provides the electric field necessary to displace the substrate and thus form an acoustic wave. The wave propagates through the substrate, where it is converted back to an electric field at the IDT on the other side. FIG. 2 shows the configuration of a typical acoustic wave device which is used as a wireless temperature sensor of the system of the present invention. Transverse, or shear, waves have particle displacements that are normal to the direction of wave propagation and which can be polarized so that the particle displacements are either parallel to or normal to the sensing surface.
[0064] All acoustic wave devices are sensors in that they are sensitive to perturbations of many different physical parameters. Any change in the characteristics of the path over which the acoustic wave propagates will result in a change in the output.
[0065] According to an embodiment of the invention, a wireless temperature sensor can be created by selecting the correct orientation of propagation. The propagating medium changes with temperature, affecting the output.
[0066] Surface wave velocities are temperature dependent and are determined by the orientation and type of crystalline material used to fabricate the sensor. Temperature sensors based on SAW delay line oscillators have millidegree resolution, good linearity, and low hysteresis. They are, however, very sensitive to mass loading and so must be sealed in a hermetic package. A 124 MHz ST-cut quartz, surface-skimming bulk wave temperature sensor was recently reported to have a temperature coefficient of 32 ppm/° C. and a resolution of 0.22° C. It also exhibited three orders of magnitude less sensitivity to mass loading than do SAW sensors. The response time was found to be 0.3 s, 10 3 faster than BAW sensors. These temperature sensors have the additional advantage of requiring no power and of being wireless, making them well suited for use in remote locations.
[0067] FIG. 3 shows in a cross sectional view the SAW RFID Tag 17 (similar also to SAW RFID Tags 18 and 23 of FIG. 1 ), attachment configuration and the mounting parts on a bare conductor 31 . The Tag 17 is bonded and placed under the conductor in a small niche made in the Metallic Tag Attachment Clip 32 , which is pressed with a suitable insulated pressing tool (not shown), having different heads corresponding to the clip(s) 32 and standards diameters of the different cables used for the rating currents in use. Special epoxy thermal conducting layer should be applied on the cable or inside the clip 32 before being pressed. The Tag 17 is pre-programmed (e.g., by using a development system provided by the tags suppliers), having his unique RFID Code and its current vs. temperature curve is known for the specific clip's and conductor's material. It could also be better adjusted by laboratory tests for each useful cross section, type and material of conductor.
[0068] A UV protected and good temperature insulating heat shrinking plastic, form a bonded jacket 33 with some overlapping out of the clip area, on the conductor. It should provide a good protection with one or two layers around the conductor against environmental and weather extreme conditions like wind blows or rain which could introduce errors in the temperature readings relating to the current. The reference SAW Tag 23 ( FIG. 1 ) should also be mounted with such plastic protection jacket.
[0069] According to an embodiment of the invention, each SAW RFID Tag should be placed relatively adjacent (i.e., as close as possible) to the Current Measurement Units 19 (which mounted on the pole), it is clear that it will be a field mounting and mostly under grid working conditions at high voltage levels. It is also possible to exploit maintenance works on the grid lines when the lines are out of service to install the tags on the lines conductors. In transmission power lines it is possible to use cameras temporarily (or permanently, especially where cables elongation measurement is desired), until it is possible to install tags during maintenance works when power lines are disconnected.
[0070] FIG. 4 shows the Metallic Tag Attachment Clip 32 of SAW RFID Tag 17 before pressing with the suitable insulated tool (as explained hereinabove), according to an embodiment of the present invention. The SAW RFID Tag 17 should be bonded in its special niche 42 under the clip 32 , before the pressing. A special tooth 40 made to be inserted in its appropriate slot 41 assures perfect closure. The material from which clip 32 is made of should be the same as conductors' material, in order to prevent corrosion effects and temperature expansion differences, which can harm the good temperature transmission between the conductor and the clip 32 .
[0071] Referring again to FIG. 5 , which shows in a block diagram the Current Measurement Unit (CMU) 19 , with its RFID Reader 26 communicating with the SAW RFID Tag 17 attached to the high voltage power lines conductors 15 (same for Tag 18 and conductors 16 ). The unit can read large number of SAW RFID Tags in a sequence (also simultaneously in interference free systems). In a two lines three phases high voltage, high power transmission line, it is possible to have up to six conductors per phase (equally spaced with strong spacers capable to hold them in case of strong rejecting forces due to fault currents), which mean 36 tags, or 72 tags at a splitting point.
[0072] The ADC/DAC 51 and the Controller 52 transform temperature values which are above the ambient temperature of the SAW RFID Tags 17 , 18 , into RMS currents levels. This is done according to current vs. temperature curve data which was previously fed to the controller 52 (i.e., pre-stored or programmed). The current vs. temperature curve corresponds to physical parameters of the relevant conductor (e.g., the diameter and material of the relevant conductors). In some embodiments of the present invention, it is possible to use an industrial PC board instead of controller 52 , like PC 104 (which is an embedded computer standard controlled by the PC/ 104 Consortium) to get relatively higher calculation/analysis performance of the CMU 19 as an option to extend system's capability to measure and/or transfer additional parameters and data over the power lines.
[0073] The wireless transceiver 53 , transmit the data to a Supervisory Control and Data Acquisition (SCADA) System of the whole Monitoring and Management System. The Digital Hall Effect Switch 54 provides outage detection (as described in further details hereinafter). This could be transmitted with priority by a burst signal to an Outage Control Monitors 100 at the Control Center 99 ( FIG. 9 ), to enable fast intervention. Alarm burst signals are also provided in case of temperature approach to upper rated limits of specific power lines, giving to the operators of control center 99 the relevant recommendations how to deal with the hazardous temperature increase (high speed increase due to a fault current, peak demand or overloading).
[0074] FIG. 6 schematically illustrates the Digital Hall Effect Switch 54 , which operates as follows: in normal operation mode the output FET transistor 64 is in cutoff state. In case of an outage, no magnetic field influence the Hall Plate 60 to provide an output voltage to the Differential Amplifier 61 and the output is at zero. With the inverter 63 we get conduction of the FET output 64 and alarm signal is provided to the controller 52 ( FIG. 5 ). The alarm signal is transmitted as a burst transmission with priority to the Control Center 99 .
[0075] The Hall-Effect principle is named for the physicist Edwin Hall. In 1879 he discovered that when a conducting or semi-conducting rectangular plate with current flowing from one side to the opposite side was introduced perpendicular to a magnetic field, a voltage could be measured at right angle to the current path and to the magnetic field. In other words, in x, y, z (3D) axis system, if the plate is placed with one side parallel to the x axis and the other to the y axis, then the said current, voltage and magnetic field, are parallel to x, y, z axes respectively.
[0076] The Hall Effect Switch 54 in the environment of high power poles (or towers) is working in high magnetic fields. The electronic switch is in saturation condition and the level of such magnetic field depends on the distance from the lines conductors and the degree of non symmetry. This because usually the high voltage bare cables of a three phase line are distant from each other and above the Current Measurement Unit 19 . There is always significant difference in distance to the CMU 19 between the cables, thus the closer one influence the Hall Effect Switch 54 much more than the others. As the sum of the 3 currents of a line is zero, at big distance from the line (e.g. 30 meter), where the non symmetry does not influence much, the magnetic field is almost zero. For better understanding, the graph of FIG. 7 provides an additional explanation. In low and medium voltage parts of the grid where we can meet many bundled cables in use (twisted inside the insulated jacket), the magnetic field outside the cable is much lower but high enough for the Hall Effect Switch 54 because of the non symmetry of the loads, the shift in phase and currents levels, there is always a residual magnetic field.
[0077] FIG. 7 is a graph which shows the currents of a 3-phase ideal line with equal loads and full symmetry. It is easy to see that at each point on the time axis the sum of the three currents is zero. The three currents I 1 , I 2 , and I 3 are equal in amplitude and 120° shifted from each other. It is easy to see that at zero crossing points the other two curves has the values of sin(±π/3+nπ)=±0.866 , and at the peak points (±1), the other two curves has the values of sin((−/+)π/6±nπ)=(−/+)0.5
[0078] So, as shown in this graph, in ideal conditions and far enough from the phases conductors (to consider the distance between the conductors as equal to zero), the magnetic field will also be zero. But in our case where the CMU 19 with the Digital Hall Effect Switch 54 is mounted on the conductors' towers, the circuit is working only as on/off switch indicating line outage (3-phase), with no possibility to provide fast detection of one phase disconnection (in 3-phase line or more). This could be detected by following the temperature drop of the conductor, and it takes some time to the SAW RFID Tag unit (about few minutes).
[0079] FIG. 8 shows 3 options to get energy source for the CMU 19 . The power supply unit 55 presented at FIG. 5 , could get energy either by an Inductive Charger 83 from the Power Lines 80 , or from a Solar PV Panel 21 , or in urban areas directly from the Low Voltage Power Lines 81 . The Back-up Unit 82 should be of at least 72 hours (lithium type or more advanced type), to enable for solar power source, to over come winter's cloudy days.
[0080] FIG. 9 is a bloc diagram describing the whole monitoring and management system enabling to scan in cycling of a minute or less and analyze the currents from up to millions of sensors of an electricity supply network and than display on the Outage and Loading Control Monitors of the Control Center, 100 , 101 , 99 respectively, the information about the outages and significant deviations from normal power consumption, enabling the operators to do what they should to regulate voltage, connect and disconnect generators, transformers, circuit breakers etc. On the upper side of the bloc diagram, a plurality of Current Measurement Units 93 with their following ordinary numbers (from uvwxyz 3 up to uvwxy 20 ) is shown. Each CMU should read with its Tags RFID Reader Antenna 91 , n tags 90 corresponding to n phases' conductors of the specific lines splitting point and transmit it via the transmission communication channel choose by the network management according to standards. For example, the communication channel is used in a Data collection Scanning Transceiver 97 , with its antenna 96 , which describes symbolically the reception unit of all the remote sensors for the SCADA (Supervisory Control and Data Acquisition) system 98 , collecting the data and analyzing it in its CPU.
[0081] To increase currents scanning speed, it is necessary to split the data accumulation by using the CMU's controllers/PC boards to collect the data from downstream CMU's and forward it in batch upstream up to the substations and then in batches to the computerized system of the Control Center 99 . There, by using the accumulated data base and Statistic Process Control (SPC) to detect significant variations in power consumption it enables the operators' intervention in large or local scale, in real time, as the control should work. The computerized unit (e.g., SCADA 98 ) may include Human Machine Interface (HMI), which enable to present the relevant needed information usefully for the operators on their monitors. By introducing an Interface Generator 102 it is possible to connect to the system all other useful programs and systems 103 already working successfully in the control and monitoring of the network. The software developed which includes the SCADA, SPC, HMI, Interface Generator, Displays Generator, forms a full Manufacturing Execution System (MES), as it is often used in industrial manufacturing (in this case we are in the electricity manufacturing business).
[0082] While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried into practice with many modifications, variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without departing from the spirit of the invention or exceeding the scope of the claims.
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A system for managing loads and detecting outages over electric power lines that comprises wireless temperature sensors which are attached to bare conductors of the electric power line(s), at line junctions or lines' splitting points, for sensing temperatures generated by the currents flow in the conductors. The system also includes a Current Measurement Units (CMU) for wirelessly reading the temperature sensed by the sensors, to allow cheap, rapid and easy RMS currents measurements on power lines at any voltage levels, by using temperature into current conversion formulas and tables.
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TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates, in general, to finding the end of a broken wireline disposed within a wellbore and, in particular, to an expandable wirefinder capable of traveling through a restriction within the wellbore then expanding to the diameter of the wellbore to find the end of the broken wireline and a method for use of the same.
BACKGROUND OF THE INVENTION
[0002] Once a well that traverses a subterranean hydrocarbon bearing formation has been drilled, it is common to attach a variety of tools or equipment to the end of a conductive or nonconductive wireline and lower the tools or equipment downhole to perform wireline operations. For example, certain flow control devices such as subsurface safety valves, plugs, packers, gas lift valves and the like are commonly lowered into the wellbore or retrieved from the wellbore via wireline. Similarly, certain downhole devices such as sliding sleeves and the like are commonly actuated using a service tool suspended on a wireline.
[0003] During any of the above wireline operations, there is always a risk that the wireline may break during the operation. For example, the weight of the tool string sometimes exceeds the breaking strength of the wireline. Alternatively, if the tool string may become stuck in the wellbore, it may be necessary to pull on the wireline to release the tool string. Such excessive tension on the wireline may cause the wireline to break. In addition, in the case of detonating a perforating gun, the shock generated by the perforating gun will sometimes cause the wireline to break. Furthermore, if an out of range pressure condition occurs during a wireline operation, it may be necessary to shut in the well at a set of shear rams or at a subsurface safety valve. In either case, the wireline may be cut during the shut in operation.
[0004] When such a wireline break occurs, it becomes necessary to find and retrieve the broken wireline from the wellbore. It has been found, however, that it is often difficult to find and retrieve the broken wireline as the wireline typically falls down into the wellbore and coils up against the interior wall of the wellbore. In addition, finding and retrieving such as broken wireline is particularly difficult when a wellbore restriction is present uphole of the broken wireline.
[0005] Therefore, a need has arisen for a tool that is capable of finding the end of a wireline after the wireline has broken downhole. A need has also arisen for such a tool that can pass through a restriction in the wellbore yet still find the end of the broken wireline. Further, a need has arisen for such a tool that allows for the retrieval of the broken wireline after the end of the wireline has been found.
SUMMARY OF THE INVENTION
[0006] The present invention disclosed herein comprises an expandable wirefinder and a method for using an expandable wirefinder that is capable of finding the end of a wireline after the wireline has broken downhole. The expandable wirefinder of the present invention can pass through a restriction in the wellbore yet still find the end of the broken wireline. In addition, the expandable wirefinder of the present invention allows for the retrieval of the broken wireline after the end of the wireline has been found.
[0007] The expandable wirefinder comprises a sleeve and a dual collet assembly that includes first and second collet members. Each of the collet members has plurality of collet fingers. The dual collet assembly is slidably moveable relative to the sleeve between a running position and a finding position. In the running position, the first collet member is partially disposed within the sleeve with its collet fingers inwardly radially biased by the sleeve and the second collet member is disposed within the first collet member with its collet fingers inwardly radially biased by the sleeve. In the finding position, the collet fingers of the first collet member radially expanded to form gaps therebetween and the collet fingers of the second collet member radially expanded into the gaps between the collet fingers of the first collet member.
[0008] More specifically, when the dual collet assembly is in the running position, the ends of the collet fingers of the first collet member form a circular configuration having a diameter substantially the same as a diameter of the sleeve. At the same time, the ends of the collet fingers of the second collet member substantially form a circular configuration having a diameter less than a diameter of the sleeve.
[0009] Also, when the dual collet assembly is in the finding configuration, the ends of the collet fingers of the first collet member substantially form a gapped circular configuration having a diameter larger than the diameter of the sleeve. Likewise, the ends of the collet fingers of the second collet member substantially form a gapped circular configuration having a diameter substantially the same as the diameter of the ends of the collet fingers of the first collet member. Accordingly, the expandable wirefinder of the present invention can be run downhole and pass through a restriction then expand to the diameter of the tubular in which the broken wireline in located.
[0010] In one embodiment of the expandable wirefinder of the present invention, the expandable wirefinder is used to locate the end of the broken wireline downhole then reconfigure the end of the broken wireline by bending the wireline, creating one or more loops in the broken wireline and moving the end of the broken wireline away from the inner surface of the tubular. This embodiment of the expandable wirefinder of the present invention is then pulled out of the hole and a wire grab is run into the hole to retrieve the reconfigured broken wireline from the known position.
[0011] In another embodiment of the expandable wirefinder of the present invention, the expandable wirefinder includes its own wire grab such that the locating and retrieving of the broken wireline may occur during the same trip downhole.
[0012] In another aspect of the present invention, the expandable wirefinder is operated in accord with a method comprising the steps of running an expandable wirefinder downhole on a conveying device, the expandable wire finder including a sleeve and a dual collet assembly with a wire grab, contacting a restriction downhole with the sleeve, operating the dual collet assembly from a running position to a finding position, proceeding farther downhole with the dual collet assembly in the finding position, finding the wire downhole with the dual collet assembly, grabbing the wire with the wire grab, retrieving the dual collet assembly and the wire uphole to the sleeve, operating the dual collet assembly from the finding position to the running position and retrieving the expandable wirefinder and the wire uphole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
[0014] [0014]FIG. 1 is a schematic illustration of an offshore oil and gas platform operating an expandable wirefinder according to the present invention;
[0015] [0015]FIG. 2 is a half sectional view of an expandable wirefinder according to the present invention in its running position;
[0016] [0016]FIG. 3 is a half sectional view of an expandable wirefinder according to the present invention in its running position;
[0017] [0017]FIG. 4 is a perspective view of an expandable wirefinder according to the present invention in its running position;
[0018] [0018]FIG. 5 is a half sectional view of an expandable wirefinder according to the present invention in its finding position;
[0019] [0019]FIG. 6 is a perspective view of an expandable wirefinder according to the present invention in its finding position;
[0020] [0020]FIG. 7 is a half sectional view of an expandable wirefinder having a wire grab according to the present invention in its running position; and
[0021] [0021]FIG. 8 is a half sectional view of an expandable wirefinder having a wire grab according to the present invention in its finding position.
DETAILED DESCRIPTION OF THE INVENTION
[0022] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention.
[0023] Referring initially to FIG. 1, an expandable wirefinder of the present invention for locating the end of a wireline that has broken downhole is being operated from an offshore oil and gas platform that is schematically illustrated and generally designated 10 . A semi-submersible platform 12 is centered over a submerged oil and gas formation 14 located below sea floor 16 . A subsea conductor 18 extends from deck 20 of platform 12 to sea floor 16 . A wellbore 22 extends from sea floor 16 and traverse formation 14 . Wellbore 22 includes a casing 24 that is cemented therein by cement 26 . Casing 24 has perforations 28 in the interval proximate formation 14 .
[0024] A tubing string 30 extends from wellhead 32 to formation 14 to provide a conduit for production fluids to travel to the surface. A pair of packers 34 , 36 provide a fluid seal between tubing string 30 and casing 24 and direct the flow of production fluids from formation 14 through sand control screen 38 . Disposed within tubing string 30 is a subsurface safety valve 40 that is designed to shut in the flow of production fluids if the flow exceeds a preset rate. Also disposed within tubing string 30 is a wireline operated pressure testing tool 42 that is attached on the far end of a broken wireline 44 . The near end 46 of wireline 44 is positioned against the interior surface of tubing string 30 as wireline 44 has coiled up within tubing string 30 after being cut by subsurface safety valve 40 during an out of range condition that occurred during a pressure testing operation.
[0025] In the illustrated embodiment, a fishing operation is being conducted wherein expandable wirefinder 48 is being run downhole on a conveyance 50 , such as a wireline, coiled tubing or the like, to find near end 46 of broken wireline 44 . As explained in greater detail below, expandable wirefinder 48 is not only capable of passing through the restriction crated by subsurface safety valve 40 , but is also capable of contacting the interior surface of tubing string 30 beyond the restriction such that near end 46 of broken wireline 44 may be found and wireline 44 including pressure testing tool 42 can subsequently be retrieved.
[0026] Referring next to FIG. 2, therein is depicted an expandable wirefinder of the present invention that is generally designated 60 . Expandable wirefinder 60 includes an axially extending generally tubular sleeve 62 . Sleeve 62 includes an upper sleeve section 64 , a middle sleeve section 66 that is threadably coupled to upper sleeve section 64 and a lower sleeve section 68 that is threadably coupled to middle sleeve section 66 . Upper sleeve section 64 has a profile 70 that is used to latch into a matching profile within a downhole restriction such as the receiving profile within a subsurface safety valve.
[0027] Positioned within sleeve 62 is a dual collet assembly 72 . Dual collet assembly 72 is initially coupled to lower sleeve section 68 by a plurality of shear pins 74 . Dual collet assembly 72 has a fish neck 76 that is used to couple dual collet assembly 72 to a conveyance. Dual collet assembly 72 includes an outer collet member 78 having a plurality of collet fingers 80 and an inner collet member 82 having a plurality of collet fingers 84 . In the illustrated embodiment, inner collet member 82 is coupled to fish neck 76 with a pin connector 86 . Also, in the illustrated embodiment, outer collet member 78 is coupled to inner collet member 82 with a pin connector 88 . It should be understood by those skilled in the art that other types of connections may be made between inner collet member 82 and fish neck 76 and between outer collet member 78 and inner collet member 82 , such as threaded connections, without departing from the principles of the present invention.
[0028] Referring now to FIGS. 3 and 4, dual collet assembly 72 has a running position wherein outer collet member 78 is at least partially disposed within lower sleeve section 68 and inner collet member 82 is disposed within outer collet member 78 . More specifically, in this running position, collet fingers 80 of outer collet member 78 are inwardly radially biased by lower sleeve section 68 such that collet fingers 80 form a substantially cylindrical configuration. In fact, as best seen in FIG. 4, the ends of collet fingers 80 substantially form a circular configuration having a diameter substantially the same as a diameter of sleeve 62 . Accordingly, in the running position, outer collet member 78 can pass through a variety of restrictions within a wellbore including the restriction having the profile that matches profile 70 of upper sleeve section 64 .
[0029] Also in the running position of dual collet assembly 72 , collet fingers 84 of inner collet member 82 are inwardly radially biased by lower sleeve section 68 such that collet fingers 84 form a substantially cylindrical configuration. More specifically, each collet finger 84 has a radially outwardly extending lug 90 the passes through a respective window 92 of outer collet member 78 and contacts the interior surface of lower sleeve section 68 . Due to the thickness of lugs 90 , collet fingers 84 of inner collet member 82 are biased radially inwardly to a location within outer collet member 78 . In fact, as best seen in FIG. 4, the ends of collet fingers 84 substantially form a circular configuration having a diameter smaller than the diameter of the substantially circular configuration of the ends of collet fingers 80 of outer collet member 78 .
[0030] Referring now to FIGS. 5 and 6, dual collet assembly 72 has a finding position wherein dual collet assembly 72 has been released from sleeve 62 by shearing shear pins 74 after profile 70 of upper sleeve section 64 has located its matching profile in the downhole restriction. In the finding position, outer collet member 78 is no longer disposed within lower sleeve section 68 . Accordingly, collet fingers 80 of outer collet member 78 are no longer inwardly radially biased by lower sleeve section 68 . Instead, collet fingers 80 of outer collet member 78 substantially form a conical section having gaps between collet fingers 80 . In fact, as best seen in FIG. 6, the ends of collet fingers 80 of outer collet member 78 substantially form a gapped circular configuration having a diameter larger than the diameter of sleeve 62 .
[0031] Also in the finding position of dual collet assembly 72 , collet fingers 84 of inner collet member 82 are no longer inwardly radially biased by lower sleeve section 68 . Instead, collet fingers 84 of inner collet member 82 also substantially form a conical section having gaps between collet fingers 84 . In fact, as best seen in FIG. 6, the ends of collet fingers 84 of inner collet member 82 substantially form a gapped circular configuration having a diameter substantially the same as the diameter of the gapped circular configuration of the ends of collet fingers 80 of outer collet member 78 .
[0032] In the finding position of dual collet assembly 72 , collet fingers 84 of inner collet member 82 fill the gaps between collet fingers 80 of outer collet member 78 and collet fingers 80 of outer collet member 78 fill the gaps between collet fingers 84 of inner collet member 82 . Accordingly, when the diameter at the ends of collet fingers 84 of inner collet member 82 and collet fingers 80 of outer collet member 78 is substantially the same as the inner diameter of the tubular in which the broken wireline is disposed, the end of the broken wireline will be contacted by dual collet assembly 72 of expandable wirefinder 60 even when the end of the broken wireline is in contact with the inner surface of the tubular. As little or no gap is present between collet fingers 84 of inner collet member 82 and collet fingers 80 of outer collet member 78 , the end of the broken wireline cannot elude dual collet assembly 72 of expandable wirefinder 60 .
[0033] Furthermore, due to the conical shape of the interior of dual collet assembly 72 in the finding position, when the end of the broken wireline is found, the end can be bent over such that the end will no longer be in contact with the inner surface of the tubular and a conventional wire grab tool may be run downhole on a subsequent wireline trip to grab the end of the broken wireline and retrieve the broken wireline along with any tools attached to the lower end of the broken wireline to the surface.
[0034] Even though FIGS. 2 - 6 have depicted expandable wirefinder 60 as having six collet fingers 80 in outer collet member 78 and six collet fingers 84 in outer collet member 82 , it should be understood by those skilled in the art that outer collet member 78 and inner collet member 82 could alternative have other numbers of collet fingers either greater than or less than six without departing from the principles of the present invention.
[0035] In operation, dual collet assembly 72 is pinned within sleeve 62 such that outer collet member 78 is at least partially disposed within lower sleeve section 68 and inner collet member 82 is disposed within outer collet member 78 . In this running position, expandable wirefinder 60 may be run downhole on a conveyance such as a wireline. When expandable wirefinder 60 reaches a restriction in the wellbore, such as subsurface safety valve 40 of FIG. 1, dual collet assembly 72 as well as lower sleeve section 68 and middle sleeve section 66 can pass through the restrictions. The downward travel of expandable wirefinder 60 is stopped, however, when profile 70 of upper sleeve section 64 is received within a matching profile within the restriction.
[0036] At this point, shear pins 74 are sheared by appropriate axial jarring such that dual collet assembly 72 including fish neck 76 , outer collet member 78 and inner collet member 82 is disconnected from sleeve 62 . Dual collet assembly 72 is now free to continue its downhole decent as additional length of the conveyance is feed into the well. As dual collet assembly 72 is slidably released from sleeve 62 , dual collet assembly 72 shifts from its running position to its finding position. During the shifting process, collet fingers 80 of outer collet member 78 begin to radially expand such that gaps are formed therebetween. Thereafter, collet fingers 84 of inner collet member 82 begin to radially expand such that gaps are formed therebetween. As dual collet assembly 72 nears the fully expanded or finding position, collet fingers 84 of inner collet member 82 fill the gaps between collet fingers 80 of outer collet member 78 and collet fingers 80 of outer collet member 78 fill the gaps between collet fingers 84 of inner collet member 82 leaving no gaps between any of the collet fingers.
[0037] In the finding position, collet fingers 84 of inner collet member 82 and collet fingers 80 of outer collet member 78 preferably contact the interior surface of the tubular in which the broken wireline is disposed. Dual collet assembly 72 is then run farther downhole until dual collet assembly 72 contacts the end of the broken wireline. The weight of dual collet assembly 72 and the conveyance are then allowed to act on the end of the broken wireline in, for example, a cyclical manner. Due to the conical interior shape of dual collet assembly 72 , this process bends the end of the broken wireline preferably creating one or more loops in the broken wireline and moving the end of the broken wireline away from the inner surface of the tubular and toward the center of the tubular.
[0038] Once the end of the broken wireline has been appropriately reconfigured, expandable wirefinder 60 of the present invention may be retrieved to the surface. Specifically, the conveyance is pulled out of the hole until dual collet assembly 72 reaches sleeve 62 . As dual collet assembly 72 slidably enters sleeve 62 , dual collet assembly 72 shifts from its finding position to its running position. Specifically, lugs 90 of collet fingers 84 of inner collet member 82 contact the end of lower sleeve section 68 which inwardly radially biases collet fingers 84 and retracts collet fingers 84 out of the gaps between collet fingers 80 of outer collet member 78 . Further movement of dual collet assembly 72 into sleeve 62 causes collet fingers 80 of outer collet member 78 to contact the end of lower sleeve section 68 which inwardly radially biases collet fingers 80 .
[0039] Once dual collet assembly 72 has returned to its running position, appropriate tension on the conveyance will cause profile 70 to release from its matching profile in the restriction such that expandable wirefinder 60 may be retrieved to the surface. Thereafter, a suitable wire grab may be attached to the end of the conveyance and run downhole to the known location of the end of the broken wireline which is now in a configuration that is conducive to being caught in the wire grab such that the broken wireline may be retrieved to the surface.
[0040] Referring next to FIGS. 7 and 8, therein is depicted another embodiment of an expandable wirefinder of the present invention in its running position and its finding position, respectively, that is generally designated 160 . Expandable wirefinder 160 includes an axially extending generally tubular sleeve 162 . Sleeve 162 includes an upper sleeve section (not pictured), a middle sleeve section (not pictured) that is threadably coupled to the upper sleeve section and a lower sleeve section 168 that is threadably coupled to the middle sleeve section. As described above with reference to expandable wirefinder 60 in FIG. 2, the upper sleeve section of expandable wirefinder 160 has a profile that is used to latch into a matching profile within a downhole restriction such as the receiving profile within a subsurface safety valve.
[0041] Positioned within sleeve 162 is a dual collet assembly 172 . Dual collet assembly 172 is initially coupled to lower sleeve section 168 by a plurality of shear pins 174 . Dual collet assembly 172 has a fish neck 176 that is used to couple dual collet assembly 172 to a conveyance. Dual collet assembly 172 includes an outer collet member 178 having a plurality of collet fingers 180 and an inner collet member 182 having a plurality of collet fingers 184 . In the illustrated embodiment, inner collet member 182 is coupled to fish neck 176 with a pin connector 186 . Also, in the illustrated embodiment, outer collet member 178 is coupled to inner collet member 182 with a pin connector 188 .
[0042] Expandable wirefinder 160 operates in a manner that is similar to expandable wirefinder 60 described above, except expandable wirefinder 160 carries its own wire grab mechanism depicted herein as a wireline spear 190 . In the illustrated embodiment, wireline spear 190 is threadably coupled to inner collet member 182 . Wireline spear 190 axially extends into the region surrounded by collet fingers 184 of inner collet member 182 when dual collet assembly 172 is in the running position. When dual collet assembly 172 is in the finding position, wireline spear 190 axially extends into the region surrounded by collet fingers 184 of inner collet member 182 and by collet fingers 182 of outer collet member 178 . In this position, once the end of the broken wireline is found and the weight of dual collet assembly 172 and the conveyance are applied on the end of the broken wireline to bend the wireline and create loops, wireline spear 190 can grab the broken wireline such that it can be found and retrieved to the surface in a single trip of expandable wirefinder 160 .
[0043] Even though expandable wirefinder 160 has been described as having a wireline spear type wire grab, other types of wire grabs such as a pronged U-shaped wire grab, a dog knot type wire grab or the like may alternatively be used in conjunction with expandable wirefinder 160 without departing from the principles of the present invention.
[0044] While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.
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An expandable wirefinder ( 60 ) for locating a wire downhole comprises a sleeve ( 62 ) and a dual collet assembly ( 72 ). The dual collet assembly ( 72 ) has first and second collet members ( 78, 82 ) each having plurality of collet fingers ( 80, 84 ). The dual collet assembly ( 72 ) is slidable relative to the sleeve ( 62 ) to operate between running and finding positions. In the running position, the first collet member ( 78 ) is partially disposed within the sleeve ( 62 ) with its collet fingers ( 80 ) inwardly radially biased by the sleeve ( 62 ) and the second collet member ( 82 ) is disposed within the first collet member ( 78 ) with its collet fingers inwardly ( 84 ) radially biased by the sleeve ( 62 ). In the finding position, the collet fingers ( 80 ) of the first collet member ( 78 ) radially expand to form gaps therebetween and the collet fingers ( 84 ) of the second collet member ( 82 ) radially expand into the gaps.
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BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates generally to an air-operated disk brake for vehicles, particularly for utility vehicles, preferably a utility vehicle disk brake with a ratio between the inside disk diameter and the outside disk diameter of 0.6. The brakes have brake shoes with brake linings arranged on both sides of a brake disk, have an application device for the application of one of the brake shoes and have a force transmission device for transmitting the application force to the brake shoe on the other side of the brake disk. The invention also relates to a method for the manufacturing thereof.
A disk brake of this type is illustrated in German Patent Document DE PS 37 16 202. The disk brake disclosed in this document is pneumatically operated and is therefore suitable mainly for use in the utility vehicle field, where it has had good results in practice. A cast caliper is used as the force transmitting device for transmitting the application force to the brake shoe on the other side of the brake disk. Constructive simplification is desirable for reducing the weight and lowering the manufacturing costs. The invention aims at solving this problem.
The invention achieves this goal. In contrast to the prior art of this type, a one-piece or multi-part modular element is provided for receiving elements of the application device, which are significant with respect to the operation. The force transmitting device is constructed as a closed frame which surrounds the modular element together with the application device inserted in the modular element as well as both brake shoes (particularly such that it completely absorbs the application forces). The modular element is constructed such that it significantly increases the rigidity of the frame in the area of the modular element. The modular element preferably increases the rigidity of the frame such that, in the area of the modular element, the frame essentially absorbs only normal forces, that is, tension and/or pressure forces.
The special advantage of this construction is replacing the massive cast caliper which is customary in the case of disk brakes and, in pneumatically and hydraulically operated utility vehicle disk brakes, is even considered indispensable. The frame must only surround the operationally necessary elements of the disk brake such that the transmission to the side of the brake disk facing away from the application device or the second brake shoe with the second brake lining will present no problems. The modular element ensures a sufficient rigidity of the construction while the frame has a simple design. The invention therefore has the particular advantage of weight reduction and drastically lowers the costs for manufacturing the brake.
Although attempts were made in the field of hydraulically operated disk brakes for passenger cars to simplify or even save the caliper, the solutions selected cannot be applied to utility vehicle dimensions. Thus, for example, German Patent Document DE OS 42 36 683 shows a floating caliper partial-lining disk brake, for achieving a lower weight and lower manufacturing costs. The floating caliper is formed of two axially spaced parts which are connected with one another by struts made of a high-strength material which extend over the brake disk and bridge the distance between the caliper parts.
The shown disk brake is constructed as a hydraulic brake and, because of its mechanical construction, is suitable only for a use in passenger cars. A similar solution is shown by German Patent Document DE OS 27 42 319, wherein a U-shaped bow is fastened on its open side to a tensioning device. However, it was recognized in none of these documents that it is particularly advantageous for the device for transmitting and absorbing brake reaction forces to virtually enclose the "whole" brake all around. Additional connection points to other elements, such as brake anchors, etc., which may always be a possible source of failure, are eliminated.
From European Patent Document EP 0108 680, a hydraulically operated disk brake is known whose caliper is produced in a light-weight construction as a sheet metal frame. However, this is still a complete caliper which has a simple and therefore inexpensive construction only because it is used in light passenger cars. This construction cannot be transferred to utility vehicles because the occurring braking forces are much larger than in the case of passenger cars. On the contrary, a massive cast caliper would be obtained again if it were tried, based on the construction of European Patent Document EP 0 108 680, to implement a disk brake also suitable for heavy utility vehicles.
In order to utilize the advantages of a low-cost frame also for utility vehicles, in contrast to the above-mentioned light hydraulic brakes which implement the caliper only as an inexpensive caliper corresponding to the braking forces to be controlled, the invention divides the caliper into two components: the frame and the modular element. The modular element accommodates the application device (and its operationally important parts) as well as preferably also the bearing of the brake anchor. The modular element is preferably constructed and geometrically dimensioned such that the frame is used only for transmitting tensile forces and can be limited to a minimal constructive shape (for example, as a surrounding band). The remaining inherent rigidity of the brake is essentially implemented by the modular element.
The whole application mechanism can be integrated in the modular element (and optionally the guiding device relative to the brake anchor, which guiding device corresponds to the conventional "caliper guide"). The modular element, which is preferably constructed as a diecast part and/or consists of light metal, has recesses/openings for this purpose into which the whole application mechanism can be inserted. In a particularly advantageous manner, this permit a type of premounting of the "brake core", i.e., of the application mechanism together with the adjusting devices and the brake anchor guide. Thus premounted unit must only still be placed in the surrounding frame. In this manner, the manufacturing costs are reduced further. From the interaction of the modular element and the frame, an adequate caliper operation and a complete replacement of a cast caliper is achieved by two particularly lightly constructed elements at reasonable cost.
Since the module can be constructed as a diecast part, only little machining may be needed and thus a low-cost machining obtained. Diecasting can be used because all application forces are applied only in the form of compressive strains. In comparison to conventional disk brakes for utility vehicles with a cast caliper, the modular unit is particularly light. In addition, the invention results in a modular solution because the different installation conditions can easily be met by a modification of the frame, the module, as a rule, remaining unchanged. In contrast to conventional cast constructions, installation advantages are obtained because high-strength materials can be used in comparison to castings, which are also lighter.
Constructively and for reasons of a uniformly distributed force transmission, it is also a special advantage for the frame and the modular element to be constructed such that a flat supporting of the modular element takes place in the braking torque direction, that is, on the side of the modular element facing away from the brake disk. The module therefore absorbs the application forces our a large-surface. This can also be promoted by the fact that the frame is constructed as a band (in the case of a utility vehicle brake, the band is, for example, approximately 5 cm wide). The band preferably consists of deformed steel plates which are firmly welded to one another and/or riveted to one another. The low- cost band produced in this manner can also safely withstand the most strenuous constant stress and can be designed in a particularly simple manner, if it is provided with devices for reinforcing the frame (such as "tension" struts).
According to another, particularly preferred variant of the invention, at least some of the struts reach through recesses of the modular unit so that the modular unit is secured in a simple manner against a falling-out and can be mounted in an uncomplicated fashion. In addition, the struts provide the frame with rigidity. In a secure form, the frame comprises the modular element as well as both brake linings as well as the upper section of the brake anchor. Optionally, a stabilizing element is inserted on the inside between the frame and the brake lining or brake shoe on the side of the brake disk situated opposite the modular element.
Summarizing, as the result of the low requirements with respect to the material and the uncomplicated mounting of the invention, a disk brake is obtained which can be produced at an extremely reasonable price and is suitable also for the continuous and industrial scale use in heavy utility vehicles.
According to a further development and variant according to the invention, the invention solves the problem of a disk brake of this type in that the force transmitting device is constructed as a closed frame which surrounds the application device as well as both brake shoes at least essentially, the frame at least partially having a wound structure. The frame (for example, together with an optional modular element) is preferably constructed as a composite part which has a wound structure at least in the area of the flow of force between the operating side and the reaction side. In contrast to the prior art of this type, this disk brake has a higher structural rigidity as well as a clearly reduced weight.
In comparison to the known cast calipers made of high-strength iron materials, the construction according to the invention has the special advantage that, because of its particularly simple design and geometry, the frame must absorb no complex and superimposed tension conditions from tensile/pressure and bending stresses. The wound structure transmits only the occurring reaction forces between the application side and the reaction side. Because of its wound structure, it is also less susceptible to cracks than the prior art. In addition, because of the wound structure (with a suitable selection of material), a frame can be implemented which has a particularly small cross-section, which again lowers the weight of the brake and the manufacturing costs.
In a particularly preferred manner, the one-piece or multi-part modular element is again provided with recesses for receiving operationally necessary elements of the application device. The wound structure is constructed as a wound frame which surrounds the modular element as well as the two brake shoes. The modular or basic element is again further developed such that it carries out all functions of a caliper (with the exception of a complete load absorption).
The wound structure expediently consists of a high-strength material whose modulus of elasticity is lower than the modulus of elasticity of the wound frame. The special advantage of a reinforcing winding of a high-strength material is that its cross-section can be dimensioned to be so small that it is arranged precisely in the flow of force of the caliper frame without impairing other functions of the caliper. As a result, the transmission of the reaction forces takes place exclusively in the reinforcing winding in the form of tensile stresses and the basic body is only exposed to low stresses. This also makes it possible for the basic body to be cast of light metals, such as aluminum, and to be designed to be less stable than in the prior art, which again lowers the weight of the disk brake as well as its manufacturing costs. According to another variant of the invention, it is finally even possible to construct the modular element to be resilient in sections.
According to another particularly preferred variant of the invention, the modular element also has open grooves or closed passage ducts which are designed for the complete or partial accommodation of the winding structure. The grooves considerably simplify the manufacturing of the disk brakes because it is only necessary to place the prefabricated wound frame in these grooves during the mounting of the brake. As an alternative, it is also possible for the wound frame to be cast in the light-metal casting of the modular element. Although in this case the frame still surrounds the significant sections of the application device, a composite part is created which is particularly reliable in the continuous operation.
A simple method is provided for manufacturing the disk brakes according to the invention wherein the force transmitting device is wound as a closed frame from a (for example, synthetic) fiber.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a first sectional view of a disk brake according to the invention;
FIG. 2 is another sectional view of the disk brake according to the invention of FIG. 1; and
FIGS. 3 to 7 are various views of another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The disk brake 1 illustrated in FIG. 1 is constructed as a pneumatically operated disk brake for utility vehicles. When a brake cylinder (not shown here) is operated, an eccentrically roller-disposed lever 2 is operated by the piston rod (also not shown) of the cylinder. The introduced force is transmitted by the bridge 3 and integrated threaded spindles 4 with plungers 5 to the brake shoe 6 (with a--preferably two-layer--lining carrier 7, lining material 8 and an antirattle spring 9) with a force F1. The brake shoe 6 is supported on the brake disk 10.
Before the transmission of the braking force to the other side of the brake disk will be explained, the function of the wear adjustment will be briefly stated. An automatic wear adjusting device (adjusting device) 11 is situated in one of the two tube-shaped threaded spindles 4 which are connected with one another by a (not shown) chain or an analogous device. During each brake operation, the lever 2 operates the adjusting device 11 by a shift fork (not shown). The adjusting device 11 has an inner sleeve 12 which is rotated along by the rotation of the shift fork. The rotating movement is transmitted by a ball ramp 13 to the threaded spindle 4. In the case of a correct lifting play, no adjustment will take place.
For the transmission of the braking force to the other side of the brake disk 10 or the brake shoe 6', a force transmitting device 14 is used instead of the otherwise customary cast caliper construction. The force transmitting device 14 is constructed in the manner of a frame 14 which is closed on all sides and which completely absorbs the application forces. The frame 14 encloses a modular element 15 as well as both brake shoes 6 and 6' and the upper section of the brake anchor 17.
In the one-piece modular element 15 constructed as a diecast part, a guiding device 16 is integrated which corresponds to the conventional "brake caliper guide". In addition, the whole application device or mechanism (parts 2 to 5) together with the adjusting device (11-13) are integrated in a premountable manner in correspondingly constructed recesses of the modular element 15.
The band-type frame 14 and the modular element 15 are constructed such that a flat supporting of the modular element takes place in the braking torque direction, that is, in the side of the modular element facing away from the brake disk; see arrow A. In area B, the band-type frame 14 is fixedly welded and riveted.
As illustrated in FIG. 2, the frame 14 is provided with strut-type devices 18 which provide the frame 14 with additional rigidity. The struts 18 reach through recesses 19 of the modular unit 15 so that the fit of the modular unit 15 is defined in a simple manner. A stabilizing element 20 (here, a steel structure) is also inserted between the frame 14 and the brake shoe 6' on the side of the brake disk 10 opposite the modular element 15. By a variation of the geometry of this element, the brake can be adapted in a simple manner to the most varied installation situations.
Another embodiment of the invention is illustrated in FIGS. 3 to 7. In this embodiment, a wound frame 14' is used instead of a band-type frame. The wound frame 14' has two winding strands 21a and b which are situated directly side-by-side and are wound in a "cable-type" manner from carbon fibers. The fibers are aligned essentially in the direction of the flow of force. The structure formed in this manner is highly stable and largely insensitive to the formation of cracks. As illustrated in the top view of FIG. 6, the wound frame 14' has a rectangular geometry which can therefore be implemented extremely easily. The strands 21 have a circular cross-section and are flattened only in the area of the rounded corners of the rectangle, which is the result of the respectively necessary 90°-deflections of the wound frame. On the application side, the wound frame 14' reaches through passage ducts 22 of a modified modular element 15'. The preassembled wound frame is placed in the casting mold for the modular element 15' during the casing of the modular element 14, and is cast together with it so that a composite body is formed. Also in this embodiment of the invention, when the brake cylinder 23 is operated by a piston rod (not shown), an eccentrically roller-disposed lever 2 is operated. The introduced force is transmitted as reaction force by the bridge 3 and integrated threaded spindles (not shown here) to a brake shoe 6 with a force F1. In this case, the brake shoe 6 is supported on the brake disk (not shown). For transmitting the braking force to the other side of the brake disk or the brake shoe 6', the wound frame 14' is used, which also in this case completely absorbs the application forces.
Although the present invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only, and is not to be taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims.
REFERENCE NUMBERS
Disk brake 1
lever 2
bridge 3
threaded spindles 4
plunger 5
brake shoe 6
lining carrier 7
lining material 8
antirattling spring 9
brake disk 10
adjusting device 11
inner sleeve 12
ball ramp 13
frame 14
modular element 15
guiding device 16
brake anchor 17
struts 18
recesses 19
stabilizing element 10
wound strands 21a, b
passage ducts 22
brake cylinder 23
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A disk brake for vehicles, especially for utility vehicles, comprising brake shoes, an application on both sides of the brake disk which applies one of the brake shoes, and a force transmitting device to transmit application force to the brake shoe on the other side of the disk brake. The force transmitting device is shaped like a fully enclosed frame, which absorbs the application forces. A modular element of the force transmitting device enables brake mechanism to be premounted and improves structural rigidity.
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BACKGROUND
[0001] Food preparation may involve many kinds of applications of tools and ingredients. There are currently tools on the market that can handle food so as to move it from one dish to another dish, or a pan to a pot, or a pan to a dish. There are currently tools that facilitate the application of one set of ingredients to another set of ingredients, including tools that bask, and tools that transport sauces. There are also tools that take measurements of food parameters, such as temperature and volume. However, there is generally a lack of tools that combine these applications into a single usable device.
SUMMARY
[0002] It is an object of this invention to provide an improved culinary device.
[0003] In one aspect, the device comprises a handle. The handle is designed to be held by a human hand, and may comprise any shape or size fit for that purpose. It may be at least partly made of any suitable rigid material, such as wood or plastic. The handle may have a front portion, a back portion, a top portion, and a bottom portion. It may also have one or more side portions, which connect the top and bottom portions. The top, bottom, and/or side portions may be round, flat, angular, or any combination thereof.
[0004] The handle may have an elongated shape to conform to the substantially closed palm of a hand. The primary axis of this elongated shape may be substantially straight, or it may curve, preferably near the front portion, so that the user of the device may operate it upon a target (such as a piece of meat) at a slight angle, thereby obviating the need to bend the wrist. This curve may be anywhere between zero and one hundred and eighty degrees from the primary axis.
[0005] The handle may feature one or more ridges or grooves to match the thumb and fingers of a normal-sized hand. In one version, the thumb ridge is disposed on the top portion closer to the front portion, and the finger ridges are disposed on the bottom portion. In another version, the finger ridges are disposed on one side portion and the thumb ridge is disposed on the opposite side portion.
[0006] In one embodiment, the handle comprises an inner surface and an outer surface, with the inner surface comprising a cavity. The handle may comprise a first opening at the front portion and a second opening at the back portion. The opening may be closable by a top of a suitable type.
[0007] In another embodiment, the handle comprises a window on the top portion. The window may comprise an opening or a transparent pane permitting, respectively, access or a view into the cavity.
[0008] In one aspect, the device may comprise a chamber which may be filled with a fluid material, such as a sauce. The chamber may be of any size or shape, but preferably cylindrical. It may be made of any suitable materials, such as plastic or silicon. The chamber may be elastic, rigid, or partly elastic and partly rigid. It may be opaque or transparent, or feature opaque and transparent portions.
[0009] In one aspect, the device comprises a volumetric measuring means to detect the amount of fluid material stored in the device, and consequently, to determine how much is being used or applied to the target. The volumetric measuring means may comprise an at least partly transparent section featuring graduate and subgraduate lines. The lines may be arranged on the chamber to correspond to measurements in fluid ounces or milliliters. The lines may cover only a portion of the chamber or wrap around the circumference that surrounds its primary axis. Ideally, at least a portion of each line should align with the window of the handle. In one embodiment, the lines are arranged on a transparent pane fitted to the window.
[0010] The chamber may comprise an outer surface and an inner surface, the latter being in contact with the fluid material. The chamber may further comprise a first end and a second end.
[0011] In one embodiment, the first end may comprise a first opening that may dispense the fluid onto the target directly or through another component of the device. In one version, the first opening extends from the first end and forms a nozzle. In another embodiment, the first opening may be adapted to be used to fill the chamber with the fluid material.
[0012] In one embodiment, the chamber may also comprise a second opening, which is located at the second end of the chamber. In one version, the second end may be disposed for receiving a plunger. Pressing the plunger toward the first opening will force the fluid material through the first opening. In one variation of this embodiment, the plunger is pressed coaxial to the primary axis of the chamber. In another variation, a portion of the plunger protrudes sufficiently perpendicularly to the primary axis such that it can be pressed by the user along an axis parallel to the primary axis. In another version, the plunger may be removed, the fluid material may be placed into the chamber via the second opening, and then at least part of the plunger may be re-inserted into the chamber via the second opening.
[0013] In another embodiment, the second end of the chamber comprises a rigid portion. This rigid portion may be pressed by a finger or a plunger to compress the chamber, thereby pressing the fluid material through the first end.
[0014] In one embodiment, the chamber comprises threads that may couple with cavity threads disposed on the inner surface of the handle. By rotating the chamber threads in the direction of the cavity threads, the chamber may be snugly fitted to the cavity. By rotating the chamber threads in the reverse direction of the cavity threads, the chamber may be removed. In one version, the chamber threads are disposed near the first end of the chamber and the cavity threads are disposed on the inner surface near the front portion of the handle. In another version, the chamber threads are disposed near the second end of the chamber and the cavity threads are disposed on the inner surface near the back portion of the handle.
[0015] In one embodiment, the chamber comprises a track that may be coupled with a track disposed in the cavity. Both tracks may run coaxially to the primary axes of the handle and chamber. When these tracks are engaged, the chamber can be slided in and out of the cavity in a regular manner.
[0016] In one embodiment, the chamber comprises one or more tabs near the second end. These one or more tabs allow the chamber to pulled out and/or rotated in relation to the cavity. In another embodiment, the chamber is permanently integrated into or identical to the cavity.
[0017] In one aspect, the device comprises a head. The head may comprise a utensil end and an attachment end. The utensil end may comprise a brush, a fork, a nozzle, or other conceivable cooking utensils. The attachment end may permenantly or modularly attach to the front portion of the handle such that one head may be replaced with another head featuring a different utensil end. The head may adhere to the same primary axis of the handle, or it may be angled away to assist in the user in operating the device without bending the wrist. The angle may be zero degrees, one hundred and eight degrees, or anything inbetween.
[0018] In one embodiment, the attachment end may comprise threading to engage with threading disposed on the outer surface of the front portion of the handle. When the attachment end is rotated in the same direction as the threads on the handle, the head is tightened to the handle. Rotating the head in the reverse direction will loosen the attachment, causing the head and handle to separate.
[0019] In one embodiment, the head comprises an opening on the attachment end. The head opening may align with the first opening of the handle and the first opening of the chamber, or it may receive the nozzle of the chamber through the first opening of the handle. In one version, the head opening is connected to a channel that runs through the attachment end into the utensil end. The channel is a tube or substantially cylindrical component that provides a transfer of the fluid material from the chamber to the target. In another version, the channel runs through the attachment end and to the exterior of the device; upon reaching the exterior, it terminates in a spout. In this version, the fluid material may be applied to the target directly, without the utensil end acting as a mediary.
[0020] In one aspect, the device comprises a temperature sensing means. The temperature sensing means may be a thermometer or any suitable means to detect and express temperature. It may comprise a bulb filled with a liquid or gas that expands or exerts pressure when heated and compresses or relieves pressure when cooled. It may also comprise a visible or digital scale portion for reading the temperature, wherein the temperature is derived from the activity of the matter in the bulb.
[0021] The temperature sensing means may be housed in a recess of the handle. This recess may be embedded in the elongated section of the handle or in a temperature housing that extends from the main body of the handle. The housing may comprise a window, permitting the user to view the scale, and a bulb opening from which the bulb may protrude. In one embodiment, the temperature sensing means comprises a tab that protrudes through a groove or the window of the temperature housing, The tab may be slided by the user along the groove or window, thereby extending it through the opening in order to place it in contact with the target and then retracting it to prevent it from being damaged or obstructing another operation of the device.
[0022] In one embodiment, the temperature housing may be modularly attachable to the handle. The temperature housing may slidably coupled by a track disposed on the temperature housing to a track disposed on the top, bottom, or a side portion of the handle.
[0023] In one aspect, the device comprises an illumination means. The illumination means may comprise a cluster of light emitting diodes or any suitable electric light. The illumination means may also comprise a power source such as a battery and a button or swith to open and close the flow of electricity through a circuit connecting the power source and the electric light.
[0024] The illumination means may be housed in a recess of the handle. This recess may be embedded in main body of the handle or in an illumination housing that extends from the main body of the handle. In one embodiment, the illumination housing may be modularly attachable to the handle. The illumination housing may slidably coupled by a track disposed on the illumination housing to a track disposed on the top, bottom, or a side portion of the handle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a side view of an exemplary culinary device.
[0026] FIG. 2 is a side view of an exemplary culinary device.
[0027] FIG. 3 is an exploded view of an exemplary culinary device.
[0028] FIG. 4 is a cross-sectional view of a head of the exemplary culinary device in FIG. 3 .
[0029] FIG. 5 is a cross-sectional view of a modified version of the head of the exemplary culinary device in FIG. 3 .
[0030] FIG. 6 is an alternative cross-sectional view of a modified version of the head of the exemplary culinary device in FIG. 3 .
DETAILED DESCRIPTION
[0031] FIG. 1 shows an exemplary culinary device featuring a handle 10 , a head 20 , and chamber 30 . The chamber can be used to store fluids. These fluid levels are viewable through the handle by means of the handle window 40 , and measurable by means of the volumetric measuring lines 50 that are featured on a transparent section of the chamber. The window is disposed on a side portion 60 of the handle, between a front portion 70 of the handle and a back portion 80 of the handle.
[0032] FIG. 2 shows an exemplary culinary device featuring a temperature housing 90 and an illumination housing 100 . The temperature housing comprises a recess (not shown) that houses a temperature measuring device (not fully shown), a bulb opening 110 that receives and through which the temperature sensing portion 120 of the temperature measuring device protrudes, a window 130 that permits the viewing of a scale portion 140 of the temperature measuring device, and a groove 150 through which a tab 160 of the temperature measuring device protrudes. The illumination housing comprises a recess that houses a light source 170 and a power source 180 . The light source is directed toward the head.
[0033] FIG. 3 shows an exemplary culinary device featuring an outer surface 190 of the handle and an inner surface 200 of the handle. The inner surface of the handle forms a cavity 210 which can receive the chamber.
[0034] The chamber features a first end 220 and a second end 230 . The first end features a first opening 240 and the second end features a second opening 250 . Similarly, the handle features a first handle opening 260 proximal to the front portion and a second handle opening 270 proximal to the back portion. When the chamber enters the cavity by way of the second handle opening, the first chamber opening aligns with the first handle opening. The first chamber opening may form a nozzle 280 , which may enter and be received by the first handle opening. A plunger 290 is disposed at least partly in the chamber by way of the second chamber opening.
[0035] The cavity features cavity threads 300 which are engageable with chamber threads 310 disposed on the chamber. When these threads are rotatably engaged, the chamber is substantially locked into the cavity and can only be removed by reversibly rotating the chamber with respect to the cavity. A tab 320 extending perpendicularly from the second end fasciliates the rotating and reversible rotating of the chamber with respect to the cavity.
[0036] The head features an attachment end 330 , which attaches to the handle, and a utensil end 340 , which features a utensil used in cooking or food preparation. In this figure, the utensil end is a basting brush.
[0037] In FIGS. 3-4 , Handle threads 350 are disposed on the front portion of the handle, and threadably engage with the head threads 360 , which are disposed on the attachment end of the head. When the head threads and handle threads are rotationally engaged, the head and handle become locked together. In order to unlock them, it becomes necessary to reversibly rotate the head with respect to the handle. The head also features a head opening 370 , which is disposed on the attachment end. When the head and handle are attached, the first handle opening aligns with the head opening, and if the chamber has a chamber nozzle, then the chamber nozzle aligns and enters the first handle opening. Fluid material stored in the chamber can pass or be pressed through the first chamber opening, through the first handle opening, and through the head opening onto the bristles of the brush or any other kind of utensil that is used. In FIG. 5 , the head opening opens into a plurality of head channels 380 . These ends of these channels, which may communicate with the brush or other utensil end portion, are spaced apart. The fluid material may then be spread more evenly across an area of the utensil. In FIG. 6 , the head opening forms a spout 390 . The spout provides an exit for the fluid material without having to enter and/or be distributed into the utensil end.
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It is an object of this invention to provide an improved culinary device. The device has a handle, a chamber that can receive fluid such as a sauce, a means of dispensing the fluid, and a means of measuring the fluid. The device features a head, which is meant to contact a portion of food.
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SCOPE OF THE INVENTION
This invention relates to the art of evaluating an earth formation penetrated by a well bore by means of cores taken from such formation and more particularly, to a method and apparatus for generating useful measurements while the core barrel is positioned in the well bore and is operating to extract the core from the formation. Such information will hereinafter be referred to as "measurements while coring" or "MWC" data.
BACKGROUND OF THE INVENTION
The development of downhole instrumentation to evaluate drilling and coring of earth formations, has been given impetus by various governmental committees and councils. The Committee of Engineering Support for Deep Ocean Drilling for Science of the Marine Board of the National Research Council, e.g., joined with the Joint Oceanorgraphic Institutions Board (scientific advisors to National Science Foundation's ocean drilling programs) to sponsor a "Symposium on Measurement While Drilling". The proceeding of the meeting are found in "Technologies for Measurement While Drilling" National Academy Press, Washington DC, 1982. Prognosis: While instrumentation and uses involving measurements while drilling or (or "MWD"), are well-documented, gains to be obtained from measurements while coring (or "MWC"), have not yet crystallized.
Reasons: Many of most difficult well control problems occur when a core barrel is the well bore. Not only is the ability to handle well kicks reduced (because of reduced circulation capability) but there is increased likelihood of plugging and jamming. That is to say, the benefits to be gained from MWC during exploratory coring have not been documented in sufficient fashion to outweigh the safety concerns of the field operators. The above symposium had proposed use of a multisensor device to monitor coring operations, and the latter device included means for determining in real-time: weight-on-bit, torque-on-bit, resistivity, gamma response and core travel via acoustic response. Such a multisensor device is not only difficult to justify in view of the above, but it is also extremely expensive to manufacture.
SUMMARY OF THE INVENTION
In accordance with the present invention, a single measurement has been found to be surprisingly useful in providing needed MWC data in a simplified, straight-forward manner, commensurate with the status of present exploratory developments.
In a preferred embodiment, a Hall-effect device is imbedded in a custom safety sub attached to the outer core barrel adjacent to a single signature magnet fitted at the uphole terminus of the inner core barrel. During coring, circumferential passage of the Hall-effect device adjacent to the signature magnet (during rotation of the outer core barrel to generate a core), produces a series of signals of constant repetition rate. But with the occurrence of rotation of the inner core barrel (indicative of core twist-off, or core sand erosion) a change in repetition rate of the signal is produced at uphole indicating equipment connected to the Hall-effect device through downhole telemetering and power generating equipment. Result: sticking and jamming of the core can be immediately detected and uphole parameters modified to ease unsafe conditions. The safety sub of the present invention allows use of MWC equipment uphole, easily houses the Hall-effect device adjacent to the signature magnet as well as facilitates communication of data uphole for operator evaluation and reactive response, if required.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of a well bore and drilling derrick showing the environment in accordance with the present invention.
FIG. 2 is an enlarged section of the drill string of FIG. 1 illustrating still further the environment to which the present invention relates.
FIG. 3 is a view, partially in section, of a core barrel modified in accordance with the present invention.
FIGS. 4 and 5 are further details of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the general environment is shown in which the present invention is employed. It will, however, be understood that the generalized showing of FIG. 1 is only for the purpose of showing a representative environment in which the present invention may be used, and there is no intention to limit applicability of the present invention to the specific configuration of FIG. 1.
The coring apparatus shown in FIG. 1 has a derrick 10 which supports a drill string or drill stem 12 which terminates in a core barrel 14. As is well known in the art, the entire string may rotate, or the drill string may be maintained stationary and only the outer core barrel rotated. The drill string 12 is made up of a series of interconnected segments, with new segments being added as the depth of the well increases. The drill string is suspended from a movable block 15 of a winch 16 and the entire drill string is driven in rotation by a square kelly 17 which slidably passes through but is rotatably driven by the rotary table 18 of the foot of the derrick. A motor assembly 19 is connected to both operate winch 16 and rotary table 18.
The lower part of the drill string may contain one or more segments 20 of larger diameter than other segments of the drill string. As is well known in the art, these larger segments may contain sensors and electronic circuitry for sensors, and power sources, such as mud driven turbines which drive generators, to supply the electrical energy for the sensing elements. A typical example of a system in which a mud turbine, generator and sensor elements are included in a lower segment 20 is shown in U.S. Pat. No. 3,693,428 to which reference is hereby made. These elements within segment 20 will hereafter be referenced as "measuring while coring" elements or "MWC" elements. During coring a large mud stream is in circulation. It rises up through the free annular space 21 between the drill string and the wall 22 of well bore 9. That mud is delivered via a pipe 23 to a filtering and decanting system, schematically shown as tank 24. The filtered mud is then sucked by a pump 26, provided with a pulsation absorber 28, and is delivered via line 29 under pressure to a revolving injector head 30 and thence to the interior of the drill string 12 to be delivered to the core barrel 14 as well as to MWC elements within segment 20.
The mud column in drill string 12 also serves as the transmission medium for carrying signals of one (or more) coring parameters to the surface. This signal transmission is accomplished by the well known technique of mud pulse generation whereby pressure pulses are generated in the mud column at segment 20 in a form capable of being detected at the earth's surface. The signals are representative of a selected coring parameter measured within the well bore 9 at custom sub 33 above the core barrel 14.
A particular coring parameter to be sensed by the present invention is rotation of cylindrical inner barrel 34 (see FIG. 2) even though outer barrel 36 also rotates. But other parameters could also be sensed, if desired, along lines previously mentioned.
FIG. 2 also illustrates in schematic form, generation of mud pulses within drill string segment 20 indicative of the aforemention parameter associated with operations of core barrel 14.
As shown, the drilling mud flows through a variable flow orifice 37 control by plunger 38. The plunger 38 has a valve driver 39 whose electrical conductors 40 are connected to elements within sub 33. The signals generated within the sub 33 cause variations in the size of orifice 37 through controlled movement of the plunger 38 via operation of valve driver 39. As seen in the FIG., mud flow is downward in the direction of arrow 41 and impacts upon mud turbine 31. As rotation of the turbine 31 occurs, an electrical generator 32 is also caused to rotate and produce electrical energy. Such energy is transmitted to custom sub 33 via conductors 42 for use in detecting rotation of the inner core barrel 34 about central axis A--A of symmetry as discussed in detail below.
Uphole, pressure pulses established in the mud stream as a function of the aforementioned selected coring parameter, are detected at signal transducer 44 (FIG. 1) which converts the mud pulses to electrical signals having an amplitude (or intensity) proportional to the pressure in the duct. A filter 45 removes parasitic signals due to the steady pressure pulsations of the pump 26 not removed by pulsation absorber 28. Decoding device 46 produces a record of response signal 5 whose amplitude v. time characteristic is representative of the coring parameter of interest, as set forth below.
It should be noted that instead of using the electro-fluid transducing system of FIG. 2, modifications in this regard are possible. For example, electrical conductors 40 and 42 could be connected--directly--to suitable transducing and decoding means located at the earth's surface. Such direct connection would, of course, be conditioned on the fact that adequate protection of the conductors 40, 42 within the drill string 12 is possible; i.e., conductor abuse during coring operations, would be minimal.
As previously indicated, while various classes of coring parameters at core barrel 14 could be sensed during operations, it has been found that in the occurrence of relative rotation of the inner core barrel 34, as the outer barrel 36 is also rotating, is surprisingly indicative of unsafe coring conditions at the bottom of the well bore 9. That is to say, when the inner barrel 34 starts to rotate about axis of symmetry A--A of sub 33 and core barrel 14, immediate uphole action is necessary. Such occurrence is indicated at decoding device 46 by a change in the repetition intervals 6 of signal 5 measured between pulses 7 associated with the coring operations. That is to say, rotation only of the outer core barrel 36 would provide pulses 7A of constant repetition spacing 6A, while rotation of the inner core barrel 34 as the outer core barrel 36 also rotates, produces a changed interval spacing 6B between the adjacent pulses 7B.
In order to ascertain that the change in interval spacing 6B is actually due to inner core barrel rotation (and not caused by just a change in coring speed), the motor assembly 19 (FIG. 1) is fitted with a tachometer means 13. By recording the rotation of tachometer means 13 as a function of time and cross-checking the result with the recorded signal 5 of decoding device 46, the actual occurrence of inner barrel rotation is more easily determinable.
FIG. 3 illustrates the construction and operation of core barrel 14, in still more detail, with emphasis being placed on reasons for use of custom sub 33.
Assume that the custom sub 33 has an overall length L equal to that amount of a conventional outer core barrel 36 removed to accommodate sensor unit 35 of the present invention, in safety. I.e., in accordance with a particular design that is useful in the present invention, a conventional core barrel 14 has to be modified as follows. The uphole end of the outer barrel 36 must be cut away but the remaining terminus should be provided with a flanging surface 48. While the inner barrel 34 remains constructionally intact (except for modifications to mount an element of the sensor unit 35 as discussed below) a new core bearing and race support must be first provided. This is achieved via mounting the removed, previously used, core bearing 43 and its race between ledge 47 (on inner side surface 51 of outer barrel 36) and bottle-shaped retaining sleeve 52. A take-up ring 54 threadable attaches about sleeve 52 to provide needed axial leverage to affix the sleeve 52 and the core bearing 43 in its new operating environment. When the aforementioned modification has been achieved and inserted into a well bore, not only can cores be easily provided, that is, via rotation of the outer barrel 36 through the operations of the drill string as before, but also any rotation of the inner barrel 34 about axis of symmetry A--A can also be detected via sensor unit 35.
Detection occurs via sensor unit 35 wherein operations are in accordance with magnetic principles as discussed below. Since the sensor 35 contains no moving parts, it offers high reliability notwithstanding exposure to mechanical shock and vibrations in a well bore environment.
However, note that other types of rotation sensing devices (other than the magneto-electrical type depicted in the FIGS.), can be used during downhole coring operations in accordance with the present invention. For example, a simple electro-mechanical switching circuit could also be used to indicate relative inner barrel rotation, as can an electro-optical system. Both would include a downhole power source momentarily placed in contact with the mud pulsing system of FIG. 2 each time a pair of switch contacts (irrespective of whether or not the latter were mechanical or optical in operation) is closed during relative rotation of the inner barrel. For these systems, such circuit closure would occur only once each revolution of the core barrel, and the contacts would operationally mount between the inner and outer core barrels.
FIGS. 4 and 5 show the sensor unit 35 in more detail.
Although theoretically many kinds of detection devices could be used as previously mentioned, in this situation the sensor unit 35 of the present invention comprises only two elements: (i) a solid state Hall-effect device 55 mechanically imbedded at inner surface 58 of the previously mentioned retaining sleeve 52 of custom sub 33, but electrically powered by energy developed uphole at generator 32 (FIG. 2) above retaining sleeve 54, and (ii) a single signature magnet 59 (see FIG. 5) housed within recess 60 of support ring 57. Reason: low power consumption and rugged physical construction of the combination make such device ideal for operation downhole. Discussions of Hall-effect devices 55 can be found at "Art of Electronics", Horowitz et al, Cambridge U. Press, 1980 at pages 387 et seq., and 607 et seq., of which reference is made for incorporation herein as to construction and theory of operation.
The output of the Hall-effect device 55 is carried uphole to MWC circuits via the conventional conductors 40 fitted adjacent to power conductors 42 within common flexible shield 63 to form a conventional downhole wiring harness.
Since the present invention is only used during coring operations and then is removed from the well bore, more ruggedized connector systems that, say, use pressurized oil, as shown in U.S. Pat. No. 4,319,240, are unnecessary.
Rotational movement of the outer barrel 36 about central axis A--A is, of course, contemplated.
During such operations, the Hall-effect device 55 and signature magnet 59 are placed adjacent to each other only once each revolution of the core barrel. In that way the series of electrical signals, previously discussed, are generated on a repetitive basis. That is, each time the device 55 passes in close proximity of the signature magnet 59, a signal is generated. Note that the area of proximity varies with the sensitivity of the Hall-effect device 55, but in general is measured over an imaginary sector defined by a cutting plane that intersects the axis of rotation of the core barrel at about 90 degrees. The sector has a mean radial directional vector momentarily along axis B--B (FIG. 5) that intersects the side wall of the well bore; during each revolution of the core barrel, that sector momentarily captures both the Hall-effect device 55 and the signature magnet 59. Since the conductors 40, 42 and shield 63 also rotate about that axis in synchronization with uphole connection points to driver 39 (FIG. 2) and generator 32, respectively, tangling of cabling during coring operations, is prevented.
To reduce the possibility of drilling mud intrusion yet allow easy removal for repair purposes, the Hall-effect device 55 as well as signature magnet 59 are both provided with suitable mounting arrangements within the retaining sleeve 52 and support ring 57, respectively. In the case of Hall-effect device 55, after being potted within epoxy shield 64, it is fitted within a recess 65 formed at the inner surface 58 of the sleeve 52. Recess 65 is capped by a threaded insert 66 through which conductors 40, 42 and shield 63 extend. For magnet 59, its recess 60 (at the circumferential edge of support ring 57, see FIG. 5) is sealed by threadable insert 61 defining an axis B--B normal 20, but intersecting the central axis A--A of the assembly.
Of course, the support ring 57 must be affixed to the inner barrel 34 and this is achieved via threaded bolts 67, 68 and 69 equally spaced about central axis A--A that screw into the terminus 56 of the inner barrel 34, see FIG. 4. The bolts 67, 68, 69 extend through oversized holes 72 in support ring 57. The length of the bolts and the depth of threads 73 in the inner barrel 34.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the present invention and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
For example, some attention as to the materials to be used in the construction of the custom sub 33 as well as for support sleeve 57 are needed. Since both assemblies are to be magnetically non-interactive, they should be of stainless steel or monel.
Consequently, such changes and modifications are proper, equitable and intended to be within the full range of equivalence of the following claims.
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In accordance with the present invention, rotation of the inner barrel relative of the axis of symmetry of the core barrel (indicative of core twist off or core sand erosion during coring operations) is detected by a novel sensor combination comprising a Hall-effect device imbedded in a support sleeve of a custom safety sub attached to the outer core barrel adjacent to a signature magnet fitted to the inner barrel.
During coring, circumferential passage of the Hall-effect device adjacent to the signature magnet (during rotation of the outer core barrel to generate a core), produces a series of signals of constant repetition rate. But with the occurrence of rotation of the inner core barrel irregular repetition rates are produced at uphole indicating equipment connected to the Hall-effect device through conventional downhole telemetering and power generating equipment. Result: sticking and jamming of the core can be immediately detected and uphole parameters modified to ease unsafe conditions.
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RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 12/782,972, which claims the benefit of U.S. Provisional Application Ser. No. 61/179,971, filed May 20, 2009, the disclosure of which is hereby incorporated in its entirety herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to novel EP 2 receptor agonists that are useful for treating glaucoma, pain and inflammation and other conditions and indications in mammals.
BACKGROUND OF THE INVENTION
[0003] Ocular hypotensive agents are useful in the treatment of a number of various ocular hypertensive conditions, such as post-surgical and post-laser trabeculectomy ocular hypertensive episodes, glaucoma, and as presurgical adjuncts.
[0004] Glaucoma is a disease of the eye characterized by increased intraocular pressure. On the basis of its etiology, glaucoma has been classified as primary or secondary. For example, primary glaucoma in adults (congenital glaucoma) may be either open-angle or acute or chronic angle-closure. Secondary glaucoma results from pre-existing ocular diseases such as uveitis, intraocular tumor or an enlarged cataract.
[0005] The underlying causes of primary glaucoma are not yet known. The increased intraocular tension is due to the obstruction of aqueous humor outflow. In chronic open-angle glaucoma, the anterior chamber and its anatomic structures appear normal, but drainage of the aqueous humor is impeded. In acute or chronic angle-closure glaucoma, the anterior chamber is shallow, the filtration angle is narrowed, and the iris may obstruct the trabecular meshwork at the entrance of the canal of Schlemm. Dilation of the pupil may push the root of the iris forward against the angle, and may produce pupillary block and thus precipitate an acute attack. Eyes with narrow anterior chamber angles are predisposed to acute angle-closure glaucoma attacks of various degrees of severity.
[0006] Secondary glaucoma is caused by any interference with the flow of aqueous humor from the posterior chamber into the anterior chamber and subsequently, into the canal of Schlemm. Inflammatory disease of the anterior segment may prevent aqueous escape by causing complete posterior synechia in iris bombe and may plug the drainage channel with exudates. Other common causes are intraocular tumors, enlarged cataracts, central retinal vein occlusion, trauma to the eye, operative procedures and intraocular hemorrhage.
[0007] Considering all types together, glaucoma occurs in about 2% of all persons over the age of 40 and may be asymptotic for years before progressing to rapid loss of vision. In cases where surgery is not indicated, topical β-adrenoreceptor antagonists have traditionally been the drugs of choice for treating glaucoma.
[0008] It has long been known that one of the sequelae of glaucoma is damage to the optic nerve head. This damage, referred to as “cupping”, results in depressions in areas of the nerve fiber of the optic disk. Loss of sight from this cupping is progressive and can lead to blindness if the condition is not treated effectively.
[0009] Unfortunately lowering intraocular pressure by administration of drugs or by surgery to facilitate outflow of the aqueous humor is not always effective in obviating damage to the nerves in glaucomatous conditions. This apparent contradiction is addressed by Cioffi and Van Buskirk [Surv. of Ophthalmol., 38, Suppl. p. S107-16, discussion S116-17, May 1994] in the article, “Microvasculature of the Anterior Optic Nerve”. The abstract states:
The traditional definition of glaucoma as a disorder of increased intraocular pressure (IOP) oversimplifies the clinical situation. Some glaucoma patients never have higher than normal IOP and others continue to develop optic nerve damage despite maximal lowering of IOP. Another possible factor in the etiology of glaucoma may be regulation of the regional microvasculature of the anterior optic nerve. One reason to believe that microvascular factors are important is that many microvascular diseases are associated with glaucomatous optic neuropathy.
[0011] Subsequent to Cioffi, et al., Matusi published a paper on the “Ophthalmologic aspects of Systemic Vasculitis” [Nippon Rinsho, 52 (8), p. 2158-63, August 1994] and added further support to the assertion that many microvascular diseases are associated with glaucomatous optic neuropathy. The summary states:
Ocular findings of systemic vasculitis, such as polyarteritis nodosa, giant cell angitis and aortitis syndrome were reviewed. Systemic lupus erythematosus is not categorized as systemic vasculitis, however its ocular findings are microangiopathic. Therefore, review of its ocular findings was included in this paper. The most common fundus finding in these diseases is ischemic optic neuropathy or retinal vascular occlusions. Therefore several points in diagnosis or pathogenesis of optic neuropathy and retinal and choroidal vasoocclusion were discussed. Choroidal ischemia was able to be diagnosed clinically, since fluorescein angiography was applied in these lesions. When choroidal arteries are occluded, overlying retinal pigment epithelium is damaged. This causes disruption of barrier function of the epithelium and allows fluid from choroidal vasculatures to pass into subsensory retinal spaces. This is a pathogenesis of serous detachment of the retina. The retinal arterial occlusion resulted in non-perfused retina. Such hypoxic retina released angiogenesis factors which stimulate retinal and iris neovascularizations and iris neovascularizations may cause neovascular glaucoma.
[0013] B. Schwartz, in “Circulatory Defects of the Optic Disk and Retina in Ocular Hypertension and High Pressure Open-Angle Glaucoma” [Surv. Ophthalmol., 38, Suppl. pp. S23-24, May 1994] discusses the measurement of progressive defects in the optic nerve and retina associated with the progression of glaucoma. He states:
Fluorescein defects are significantly correlated with visual field loss and retinal nerve fiber layer loss. The second circulatory defect is a decrease of flow of fluorescein in the retinal vessels, especially the retinal veins, so that the greater the age, diastolic blood pressure, ocular pressure and visual field loss, the less the flow. Both the optic disk and retinal circulation defects occur in untreated ocular hypertensive eyes. These observations indicate that circulatory defects in the optic disk and retina occur in ocular hypertension and open-angle glaucoma and increase with the progression of the disease.
[0015] Thus, it is evident that there is an unmet need for agents that have neuroprotective effects in the eye that can stop or retard the progressive damage that occurs to the nerves as a result of glaucoma or other ocular afflictions.
[0016] Prostaglandins were earlier regarded as potent ocular hypertensives; however, evidence accumulated in the last two decades shows that some prostaglandins are highly effective ocular hypotensive agents and are ideally suited for the long-term medical management of glaucoma. (See, for example, Starr, M. S. Exp. Eye Res. 1971, 11, pp. 170-177; Bito, L. Z. Biological Protection with Prostaglandins Cohen, M. M., ed., Boca Raton, Fla, CRC Press Inc., 1985, pp. 231-252; and Bito, L. Z., Applied Pharmacology in the Medical Treatment of Glaucomas Drance, S. M. and Neufeld, A. H. eds., New York, Grune & Stratton, 1984, pp. 477-505). Such prostaglandins include PGF 2α , PGF 1α , PGE 2 , and certain lipid-soluble esters, such as C 1 to C 5 alkyl esters, e.g. 1-isopropyl ester, of such compounds.
SUMMARY OF THE INVENTION
[0017] The present invention provides a method of treating ocular hypertension or lowering elevated intraocular pressure (IOP) or pain or inflammation, by administering to a mammal having ocular hypertension a therapeutically effective amount of a compound 4-{[5-chloro-2-(4-chloro-benzyloxy)-benzoylamino]-methyl}-benzoic acid represented by the formula:
[0000]
[0000] including any pharmaceutically-acceptable salts and prodrugs thereof.
[0018] In a further aspect, the present invention relates to an ophthalmic solution comprising a therapeutically effective amount of a compound of the above formula or a pharmaceutically-acceptable salt thereof, in admixture with a non-toxic, ophthalmically acceptable liquid vehicle, packaged in a container suitable for metered application.
[0019] In a still further aspect, the present invention relates to a pharmaceutical product, comprising
a container adapted to dispense its contents in a metered form; and an ophthalmic solution or emulsion therein, as hereinabove defined.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention relates to the use of a certain EP 2 -receptor agonist.
[0023] The compound 4-{[5-chloro-2-(4-chloro-benzyloxy)-benzoylamino]-methyl}-benzoic acid used in accordance with the present invention are encompassed by the following structural formula:
[0000]
[0024] A pharmaceutically-acceptable salt is any salt which retains the activity of the parent compound and does not impart any deleterious or undesirable effect on the subject to whom it is administered and in the context in which it is administered. Of particular interest are salts formed with inorganic ions, such as sodium, potassium, calcium, magnesium and zinc.
[0025] Pharmaceutical compositions including the above compounds may be prepared by combining a therapeutically effective amount of at least one compound according to the present invention, or a pharmaceutically-acceptable salt thereof, as an active ingredient, with conventional ophthalmically acceptable pharmaceutical excipients, and by preparation of unit dosage forms suitable for topical ocular use. The therapeutically efficient amount typically is between about 0.0001 and about 5% (w/v), preferably about 0.001 to about 1.0% (w/v) in liquid formulations.
[0026] For ophthalmic application, preferably solutions are prepared using a physiological saline solution as a major vehicle. The pH of such ophthalmic solutions should preferably be maintained between 4.5 and 8.0 with an appropriate buffer system, a neutral pH being preferred but not essential. The formulations may also contain conventional, pharmaceutically-acceptable preservatives, stabilizers and surfactants.
[0027] Preferred preservatives that may be used in the pharmaceutical compositions of the present invention include, but are not limited to, benzalkonium chloride, chlorobutanol, thimerosal, phenylmercuric acetate and phenylmercuric nitrate. A preferred surfactant is, for example, Tween 80. Likewise, various preferred vehicles may be used in the ophthalmic preparations of the present invention. These vehicles include, but are not limited to, polyvinyl alcohol, povidone, hydroxypropyl methyl cellulose, poloxamers, carboxymethyl cellulose, hydroxyethyl cellulose cyclodextrin and purified water.
[0028] Tonicity adjustors may be added as needed or convenient. They include, but are not limited to, salts, particularly sodium chloride, potassium chloride, mannitol and glycerin, or any other suitable ophthalmically acceptable tonicity adjustor.
[0029] Various buffers and means for adjusting pH may be used so long as the resulting preparation is ophthalmically acceptable. Accordingly, buffers include acetate buffers, citrate buffers, phosphate buffers and borate buffers. Acids or bases may be used to adjust the pH of these formulations as needed.
[0030] In a similar vein, an ophthalmically acceptable antioxidant for use in the present invention includes, but is not limited to, sodium metabisulfite, sodium thiosulfate, acetylcysteine, butylated hydroxyanisole and butylated hydroxytoluene.
[0031] Other excipient components which may be included in the ophthalmic preparations are chelating agents. The preferred chelating agent is edentate disodium, although other chelating agents may also be used in place of or in conjunction with it.
[0032] The ingredients are usually used in the following amounts:
[0000]
Ingredient
Amount (% w/v)
active ingredient
about 0.001-5
preservative
0-0.10
vehicle
0-40
tonicity adjuster
0-10
buffer
0.01-10
pH adjuster
q.s. pH 4.5-8.0
antioxidant
as needed
surfactant
as needed
purified water
as needed to make
100%
[0033] The actual dose of the active compounds of the present invention depends on the specific compound, and on the condition to be treated; the selection of the appropriate dose is well within the knowledge of the skilled artisan.
[0034] The ophthalmic formulations for use in the method of the present invention are conveniently packaged in forms suitable for metered application, such as in containers equipped with a dropper, to facilitate application to the eye. Containers suitable for dropwise application are usually made of suitable inert, non-toxic plastic material, and generally contain between about 0.5 and about 15 ml solution. One package may contain one or more unit doses.
[0035] Especially preservative-free solutions are often formulated in non-resealable containers containing up to about ten, preferably up to about five units doses, where a typical unit dose is from one to about 8 drops, preferably one to about 3 drops. The volume of one drop usually is about 20-35 μl.
[0036] The invention is further illustrated by the following examples which are illustrative of a specific mode of practicing the invention and are not intended as limiting the scope of the claims.
Example I
[0037] Measurement of intraocular pressure studies in dogs will involve applanation pneumatonometry performed in Beagle dogs of both sexes. The animals will remain conscious throughout the study and will be gently restrained by hand. Compound 4-{[5-chloro-2-(4-chloro-benzyloxy)-benzoylamino]-methyl}-benzoic acid will be administered topically to one eye using a dropper bottle to deliver approximately a 35 μl volume, the other eye received vehicle (1% polysorbate 80 in 5 mM Tris HCl) as a control. Proparacaine at 0.25% was used for corneal anesthesia during tonometry. Intraocular pressure will be determined just before drug administration and at 2, 4, 6 hours thereafter on each day of the 5 day study. Measurement of ocular surface hyperemia will be performed immediately before each of the intraocular pressure readings. Ocular surface hyperemia grading will be semi-quantitative and assessed according to a 5 point scoring scale used for clinical evaluations: 0=none; 0.5=trace; 1=mild; 2=moderate; and 3=severe. It is expected that administering compound 4-{[5-chloro-2-(4-chloro-benzyloxy)-benzoylamino]-methyl}-benzoic acid will significantly reduce intraocular pressure in the eye.
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A method of treating ocular hypertension, lowering intraocular pressure, pain or inflammation, comprising administering to a mammal a pharmaceutical composition of an EP 2 -receptor agonist represented by
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to fluid-pressure operable mechanical systems. More particularly, the present invention relates to piston-and-cylinder assemblies, and may be used with advantage, for example, in applications where relatively extended stroke length is required in combination with limited distance storage requirements.
2. Description of Prior Art
Fluid pressure piston-cylinder assemblies are known for use in maneuvering various forms of equipment, and particularly for manipulating mobile apparatus used in working on wells. Thus, for example, masts may be raised or lowered on drilling rigs by way of fluid pressure cylinder assemblies.
Coiled tubing systems for working on wells are known to utilize piston-cylinder assemblies for elevating the injector head of such a system to selected positions along a mast. Such well working systems are discussed in detail in copending U.S. patent application Ser. No. 913,118 filed June 6, 1978, assigned to the same assignee as the present case, wherein improvements in coiled tubing systems are disclosed.
In prior art coiled tubing systems, a single piston-cylinder assembly is mounted along each leg of a two legged mast. The piston rods extend down the mast to support the injector head. By appropriate control of the fluid pressure applied to the cylinders, the injector head may be selectively raised or lowered along the mast.
Such masts and associated equipment may be mounted on a truck or barge. In the case of such mobile systems, the mast may be folded, for example, to achieve an acceptable road clearance profile for transportation purposes. Then, the injector head is either tilted with the folded portion of the mast as in the prior art, or is first lowered below the position of the mast hinge assemblies as disclosed in the aforementioned copending application. However, in order to provide the increased range of movement along the mast required for the injector head that may be so lowered below the mast hinge point, conventional piston-cylinder assemblies would have to be increased in both cylinder and piston rod length.
SUMMARY OF THE INVENTION
The present invention provides a double cylinder, fluid-pressure operated system. A pair of cylinders are joined together with their respective piston rods extendable in opposite directions. Each piston rod may be individually extended or retracted. An alternate form of operation of the double cylinder system involves linking the fluid pressure communication lines leading to the two cylinders so that the piston rods may be operated simultaneously and in combination. Such combined operation may be such that the piston rods extend simultaneously and retract simultaneously, or such that one piston rod extends while the other retracts.
The paired cylinders may be joined with a second pair of cylinders mutually linked in similar fashion. The fluid pressure communication lines leading to the two pairs of cylinders may also be joined so that each cylinder pair extends or retracts piston rods at the same time and in the same general direction.
Such a pair of cylinders may be mounted for movement along each leg of a two-legged mast used, for example, in a coiled tubing rig. The cylinder pairs may be joined by at least one cross-member so that all the cylinders are moved as a unit. The entire double cylinder system may be suspended from the mast at a point near the top of the mast by a piston rod extending generally upwardly from each cylinder pair. The downwardly extending piston rods may be lowered and joined to the injector head, or a carriage supporting the injector head. Operation of the double cylinder system moves the injector head to selected positions along the mast.
The combination of piston rods extendable in either direction from a floating double cylinder assembly provides a stroke length twice that of a conventional piston-cylinder assembly with the same cylinder length. Thus, the range of movement of the injector head in the referenced copending application may be increased without increasing the length of any one cylinder or piston rod. The injector head may be readily lowered below the mast hinge point as well as raised, say, two-thirds the length of the mast with the use of a double cylinder system.
To fold the mast, the injector head may be lowered below the mast hinge joint and the lower piston rods disengaged from the injector head carriage. The piston rods are all then retracted, raising the cylinders to the top of the mast, which is then tilted as desired.
The present invention thus provides a convenient means for practicing the aforementioned improvement in coiled tubing systems involving the lowering of the injector head to the base of the mast. The mast may then be folded without tilting the injector head, which is also then more accessible for servicing purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a coiled tubing system, utilizing the present invention, with the mast folded;
FIG. 2 is a view similar to FIG. 1, but with the mast erect;
FIG. 3 is an enlarged side elevation of the mast and injector head with the double cylinder elevation assembly engaged with the injector head;
FIG. 4 is a view similar to FIG. 3, showing the injector head elevated along the mast;
FIG. 5 is an end elevational view along line 5--5 of FIG. 4, partially broken away;
FIG. 6 is a cross-sectional view of the injector head framing and carriage structure along line 6--6 in FIG. 5, but with details of the injector head removed for clarity;
FIG. 7 is a cross-sectional view taken along line 7--7 of FIG. 6;
FIG. 8 is a cross-sectional view taken along line 8--8 of FIG. 6;
FIG. 9 is a cross-sectional view taken along line 9--9 of FIG. 1, illustrating the blowout preventer carriage and track system;
FIG. 10 is a fragmentary view of the mast pivot mechanism;
FIG. 11 is a fragmentary view, in cross section, of the level wind mechanism illustrating the height variation capability; and
FIG. 12 is a fragmentary exploded view in perspective illustrating the manner of pinning equipment skids to the truck bed.
DESCRIPTION OF PREFERRED EMBODIMENTS
A coiled tubing system including double cylinder apparatus according to the present invention is shown generally at 10 in FIGS. 1 and 2, mounted on the flatbed 12 of a trailer truck 14. While the improved system of the present invention may be utilized in a variety of applications, including stationary as well as mobile assemblies, and such mobile arrangements may take several forms including barge mounts or unitized carrier mounts, a trailer mounted coiled tubing application is shown and discussed herein by way of illustration rather than limitation.
The flatbed 12 supports a tubing reel assembly 16 mounted on a skid 18, a power unit 20 mounted on a skid 22, and a control house 24 mounted on a skid 26. The control house 24 includes most or all of the controls necessary for operating the various hydraulic and pneumatic systems employed with the coiled tubing apparatus, and is otherwise conventional. The power unit 20 includes the necessary power means used in operating the coiled tubing apparatus, including motors, a pneumatic compressor, and a hydraulic pump.
Both the power unit skid 22 and the control house skid 26 are anchored against lateral movement along the flatbed 12 by hold down pins 28 shown in more detail in FIG. 12. The frame of the power skid 22, for example, is equipped with at least one sleeve 30 of rectangular cross section on each side of the skid. The ends of each sleeve 30 are open through holes provided in the skid frame. The skid 22 is positioned on the flatbed 12 so that the sleeve 30 is aligned with a bracket 32 providing a passageway comparable in cross section to that of the sleeve. The pin 28 is inserted through the top of the sleeve 30 to protrude below the bottom of the bracket 32. A laterally extending lip 28a prevents the pin 28 from passing completely through the skid frame. A keeper pin 34 is inserted through a hole 28b in that portion of the pin 28 which extends below the bracket 32 to prevent inadvertent removal of the pin from the sleeve 30. With at least one such pin 28 provided on each side of skids 22 and 26, the power unit and control house are held securely in place against lateral movement along the flatbed 12. A similar hold down pin arrangement may be provided for the tube reel skid 18, or this skid may be secured by other appropriate means such as chaining or bolting the skid to the flatbed (not shown).
Tubing 36 used in the well working operation is stored on the reel 16 and is fed through a level wind guide 38 to an injector head 40. The injector head 40 is mounted on a mast shown generally at 42. The mast 42 is mounted on the flatbed 12 by bolting and/or welding.
Details of the mast construction may be appreciated by reference to FIGS. 1-5 and 10. The mast 42 includes a pair of upper mast legs 44 and 46 pivotally mounted on lower mast legs 48 and 50, respectively. The lower mast legs 48 and 50 are each fixed to the flatbed and further braced thereto by beams 52 and 54. Mast components 44 through 54 are generally of I-beam construction. An assembly of crossbeams 56 joins the tops of the upper mast legs 44 and 46 and ensures a rigid, stable mast construction.
The manner of pivotally joining the upper mast legs with the respective lower mast legs may be appreciated by reference to FIG. 10. A hinge assembly is constructed to include an upper hinge plate 58 fixed to the bottom of the upper mast leg 44 and a lower hinge plate 60 fixed to the top of the lower mast leg 48. Bracing 62 and 64 is provided for the upper and lower hinge plates, respectively. The two hinge plates 58 and 60 are joined by a hinge pin 66 about which the upper mast leg 44 pivots relative to the lower mast leg 48. A similar hinge assembly is provided whereby the upper mast leg 46 pivots relative to the lower mast leg 50, with the hinge pins of both hinge assemblies generally possessing a common rotational axis. This axis about which the upper mast section pivots is laterally displaced a short distance from the vertical projection of the lower mast legs 48 and 50. However, with the upper mast section erect, the upper mast legs 44 and 46 are placed generally directly above the lower mast legs 48 and 50, respectively, and function as continuations thereof.
The manner in which the mast pivots may be best be appreciated by reference to FIGS. 1 and 2. A pair of fluid pressure piston-cylinder assemblies 68 (only one visible) joins the upper mast legs 44 and 46 to the lower mast leg braces 52 and 54, respectively. Thus, the cylinders 68 are effectively anchored to the flatbed 12. As the pistons are retracted in the cylinder assemblies 68, the upper mast section, including the upper mast legs 44 and 46 is lowered to an essentially horizontal configuration as indicated in FIG. 1. In this posture, the upper mast section is supported by the two hinge pins and by a pair of pads 24a located on the top of the control house 24 for receiving the upper mast legs 44 and 46. The pads 24a prevent the crossbeams 56 from contacting the roof of the control house 24, leaving sufficient spacing between the house and these beams to permit the tubing 36 to pass through as indicated in FIG. 1.
As the piston rod of each cylinder 68 is extended under the influence of applied fluid pressure, the upper mast section pivots about the hinge pins as indicated by the arrow in FIG. 2. Ultimately, the upright configuration of FIGS. 2-5 is achieved wherein the upper mast legs 44 and 46 are aligned with, and resting on, the lower mast legs 48 and 50, respectively. With the upper and lower hinge plates 58 and 60 closed on each other in this upright mast configuration, a pair of swing bolts and nuts are positioned and tightened across the hinge plates of each of the two mast leg structures. As illustrated in FIGS. 5 and 10, each of the swing bolts 70 is pivotally anchored, by means of a pin 72, to the respective lower mast leg 48 or 50. The hinge plates 58 and 60 are equipped with slots to receive the swing bolts 70. With the bolts 70 thus positioned, associated nuts 74 are tightened against the upper hinge plates. The four swing bolts 70 and nuts 74 thus anchor the upper mast legs 44 and 46 to the corresponding lower mast legs 48 and 50, respectively, to maintain the upper mast section in the erect configuration.
The injector head 40 is carried by a carriage structure shown generally at 76. Details of the carriage structure may be more fully appreciated by reference to FIGS. 3-8. The carriage structure at 76 includes a horizontal carriage platform 78 and a vertical carrier assembly 80. The vertical carrier assembly 80 includes side panels 82 and 84 joined at the top by a crossmember 86 and at the bottom by a beam construction 88. A pair of channel beams 90 and 92 ride within the mast legs 44, 48 and 46, 50, respectively. The channel beams 90 and 92 are fixed on the outer surfaces of the side panels 82 and 84, respectively, and bear the left-right lateral load between the vertical carrier assembly and the mast. A pair of rollers 94 are mounted on each of the side panels 82 and 84 just beyond the upper and lower ends of each of the guides 90 and 92. The rollers 94 bear the lateral load in the forward and backward direction between the vertical carrier assembly and the corresponding mast legs. The combination of the channel beams 90 and 92 and the rollers 94 serve to guide the vertical carrier assembly 80 along the mast legs.
The horizontal carriage platform 78 features a base plate 96 and a pair of longitudinally extending side arms 98 and 100 whose cross sections resemble that of a channel beam. A plate 102 connects the back end of the side arms 98 and 100, and each of these arms is subtended at the front end by a cover plate 104.
The side arms 98 and 100 ride between upper and lower sets of rollers 106 and 108, respectively, mounted on the interior of both side plates 82 and 84. Additionally, upper and lower rails 110 and 112, respectively, are fixed to each of the side panels 82 and 84 to further constrain vertical movement of the horizontal carriage platform relative to the vertical carrier assembly.
Tubing injector heads such as the one indicated at 40 are well known in the art, and will not be described in detail herein. It should be noted, however, that the basic elements of such an injector head, including the chain dog assemblies, the motor and gear mechanisms and the chain tensioner mechanism, may be mounted within a framework 114. Further framing including horizontal members 116 and members 118 provide additional support for mounting the various injector head components. As best seen in FIG. 6, the horizontal members 116 are joined by a support post 120 and a pivot union 122 to a skid base 124. The skid base fits within the area defined by the platform side arms 98 and 100, the back plate 102, and the cover plates 104 of the horizontal carriage. As may be appreciated from FIGS. 6-8, the skid base 124 is inserted within the side arms 98 and 100 before the end plates 104 are bolted into position. Further, the skid base 124 is capable of a moderate amount of lateral movement relative to the horizontal carriage platform in forward and backward as well as sideways directions.
A bracket 126 extends upwardly from a front cross bar 124a of the skid base and is coupled to the piston rod of a fluid pressure piston-cylinder assembly 128 whose cylinder is fixed by a bracket 130 to the side arm 100 of the horizontal carriage platform. Operation of the piston-cylinder assembly 128 by application of fluid pressure thereto causes the skid base 124 to move to the right or left relative to the horizontal carriage platform as the piston rod of the cylinder is extended or retracted, respectively. In this fashion, the injector head mounted on the skid base 124 is provided a degree of freedom in a generally horizontal direction transverse to the direction of folding of the mast 42.
As illustrated in FIGS. 6 and 7, the horizontal carriage platform 78, with the skid base 124 and the injector head 40 mounted thereon, may be moved forward and backward parallel to the direction of folding of the mast 42 by means of a chain drive assembly shown generally at 132. A pair of chains 134 is anchored to the bottom of the horizontal carriage platform at points 136 and 138, and pass around a pair of idler sprockets 140 and 142 and a drive sprocket 144 between and below the idler sprockets. The shaft of the drive sprocket is coupled at 146 to a worm drive 148 which, in turn, is joined to a reversable motor 150. Operation of the motor in one rotational sense or the other causes the drive sprocket 144 to be driven through the worm drive 148 in one rotational sense or the other to move the chain forward or backward, respectively, around the drive sprocket and the idler sprockets 140 and 142. Consequently, the horizontal carriage platform 78, and, therefore, the injector head 40, are caused to move forward or backward in response to such operation of the motor 150. In this fashion, the injector head 40 is provided a degree of freedom in a generally horizontal direction along the direction in which the mast 42 is pivoted. Further, the use of the worm drive 148 provides a positive locking mechanism wherein the horizontal carriage platform 78 is maintained in the relative horizontal position in which it is located upon cessation of operation of the motor 150. This is true because any tendency for the horizontal carriage platform 78 to be moved without operation of the motor 150 causes the chain to move through, and rotate, the sprockets 140 through 144 with the result that the worm drive 148 must also be turned. Since such backward driving of the worm drive 148 through the coupling 146 is met with considerable resistance by the worm drive itself, the horizontal carriage assembly 78 is positively locked into position without operation of the motor 150.
The mast at 42 is equipped with a double cylinder pickup system including outer cylinders 152 and 154 and inner cylinders 156 and 158, as best seen in FIG. 5. The tops of the cylinders 152 through 158 are joined by a crossmember 160 which features wrap-around ends 160a which ride along the I-beam flanges of the upper mast legs 44 and 46. The lower ends of cylinders 152 and 156 are joined by an end plate 162 with a wrap-around extension 162a which also rides along the I-beam construction of upper mast leg 44. Similarly, the bottom ends of the cylinders 154 and 158 are joined by an end plate 164 with a wrap-around extension (not visible) which rides along the I-beam construction of the upper mast leg 46. The "gripping" of the members 160 through 164 of the upper mast legs 44 and 46 serves to guide the cylinders 152 through 158 along the upper mast section and prevent any separation of the cylinder system from the mast.
The outer cylinder assemblies 152 and 154 feature upwardly directed piston rods 152a and 154a, respectively, which are coupled to the top of the mast at brackets 166. The inner cylinders 156 and 158 feature downwardly directed piston rods 156a and 158a, respectively. These latter piston rods 156a and 158a may be extended downwardly and connected by pins to clevises 168 mounted on the side panels 82 and 84, respectively, of the vertical carrier assembly 80. Then, as the fluid pressure is selectively applied to the cylinder assemblies 152 through 158, the vertical carrier assembly 80 may be raised or lowered along the erect mast 42. Consequently, a third degree of motion is provided for the injector head 40 in a vertical direction along the mast.
The outer channel of each of the I-beam mast legs 44 through 50 is fitted with a series of rods 170 which function as ladder steps along the mast. The rods 170 along the upper mast legs 44 and 46 are for the most part of heavy duty design, as indicated in FIGS. 3 and 4 by their increased thickness, and protrude beyond the front surfaces of the upper mast legs in the form of studs with upset ends 170a. As shown in FIG. 5, a latch arm 172 is pivotally connected by a bracket 174 and pin 176 to the side panel 82 of the vertical carrier assembly 80. A wing 172a extends laterally from the latch arm and is joined to a fluid pressure piston-cylinder assembly 178 which is flexibly anchored to the side panel 82 by a bracket 180. As fluid pressure is appropriately applied to the piston-cylinder 178, the piston rod may be extended to swing the latch arm 172 over a stud 170a to thereby anchor the vertical carrier 80, and the injector head 40, against downward movement relative to the mast 42. With the piston of the cylinder assembly 178 contracted, the latch arm 172 is rotated clockwise, as viewed in FIG. 5, in an arc away from the studs 170a. With the latch arm 172 thus disengaged from the studs 170a, the vertical carrier assembly 80 may be raised or lowered as desired by operation of the cylinder assemblies 152 through 158. A similar pivoted latch arm, operated by a piston-cylinder assembly, is indicated at 182 mounted on the other side panel 84 of the vertical carrier assembly 80 to selectively engage or disengage studs 170a along the other upper mast leg 46. The two latch arms may be operated simultaneously by linking the fluid pressure lines leading to the corresponding piston-cylinder asemblies. Thus, in addition to the piston-cylinder assemblies 152 through 158 maintaining the vertical carrier assembly 80 and the injector head 40 at a selected elevation by appropriate application of fluid pressure to these cylinders, the latch arms are available for preventing downward movement of the vertical carrier assembly and injector head in the event of a failure in the cylinders 152 through 158, or in the fluid pressure lines leading thereto.
The lower mast legs 48 and 50 are joined together below the flatbed 12 by a crossbeam assembly 184. Screw jacks 186 carried at the base of each of the lower mast legs 48 and 50 may be extended downwardly to engage the ground prior to the elevation of the upper mast section. Thus, with the coiled tubing assembly in position to operate on a well, a significant portion of the weight of the mast 42 and the injector head 40 may be supported directly on the ground through the screw jacks 186.
An outrigger 188 is also carried by each of the lower mast legs 48 and 50, and includes a leg 190 telescoped within the outrigger sleeve and ending in a footpad 192. The leg 190 may be extended and pinned to the outer sleeve so that the footpad 192 may be placed firmly on the ground with the entire outrigger 188 oriented at an angle of, say, 45° relative to the vertical. The leg 190 is then secured at this position by a chain or cable 194 leading to the base of the associated lower mast leg. When the coiled tubing assembly of the present invention is in a transportation configuration as indicated in FIG. 1, with the mast folded, the legs 190 are retracted and the outriggers 188 are folded against the corresponding lower mast legs. Similarly, the screw jacks 186 are retracted within the inner channels of the lower mast leg I-beams.
A blowout preventer 196 is provided for use on the Christmas tree of the well on which the coiled tubing assembly is to operate. A pair of channel beams 200 (FIG. 9) are welded to the flatbed 12 between the position of the control house 24 and the anchoring of the mast 42. These channel beams 200 form a track system along which a blowout preventer carriage 202 may ride on rollers 204. The blowout preventer 196 may be carried on the carriage 202 and fastened there by any appropriate means, such as, for example, setting the blowout preventer on an upright stud 202a provided on the carriage for that purpose. For transportation and storage purposes the blowout preventer carriage 202, with the blowout preventer 196 positioned thereon, is moved toward the control house 24. In this position, the blowout preventer 196 does not interfere with the lowering of the injector head 40 so that the mast 42 may be folded, as indicated in FIG. 1. With the mast 42 erect and the injector head 40 elevated, the blowout preventer may be moved forward by advancing the carriage 202 along the track system of the channel beams 200 until the blowout preventer is positioned generally under the elevated injector head. A cable or chain 206 may be used to join the blowout preventer to the bottom of the skid base 124 as indicated in FIG. 4. The blowout preventer 196 may then be swung forward until it is in position over the Christmas tree of the well, (not shown), as indicated by the phantom lines in FIG. 4. In this fashion, the combination of the vertical carrier assembly 80 and the horizontal carriage platform 78, both supported on the mast 42, serves as a crane to allow the blowout preventer 196 to be swung into position over the well from the flatbed 12. When the well operation is completed, the cable or chain 206 may be used to reconnect the blowout preventer 196 to the skid base 124 to allow the blowout preventer to be swung back onto the carriage 202 for ultimate movement back into the storage or transportation configuration toward the control house 24, as indicated in FIG. 1.
The skid base 124 is fitted with a tube straightener 208 illustrated in detail in FIG. 6. The tube straightener 208 includes a pipe guide composed of three free wheeling rollers 210, 212, and 214 arranged in a plane with parallel rotational axes, as indicated in FIG. 6. The tubing 36 is received by the injector head 40 and passed along the chain dogs (not shown in detail) and down through the tube straightener 208. Within the tube straightener 208, the tubing 36 passes on the forward side of the rear wheels 210 and 214, and to the rearward side of the front wheel 212. The forward-backward lateral displacement of the forward wheel 212 relative to the other two wheels 210 and 214 is such that the tubing 36 is given a slight forward concave curvature to compensate for the opposite curvature enforced therein by passage through the injector head 40. Consequently, the tubing 36 emerging from the bottom of the tube straightener 208 is essentially straight.
A tubing meter 216 is provided at the vicinity of the tube straightener 208 to measure the length of tubing 36 injected into, or extracted from, the well being worked. It is particularly advantageous to place the tubing meter 216 between the injector head 40 and the well so that whatever stretching may have been effected on the tubing as it was driven downwardly by the injector head 40 will have occured prior to the measurement of the tubing length. Consequently, a relatively more accurate reading of the amount of tubing 36 actually injected into the well may be obtained.
The level wind tubing guide 38 fitted on the coiled tubing reel 16 is shown in some detail in FIG. 11. Vertical framing 218 supports a pair of end plates 220 (only one shown). A pair of lower rails 222, constructed of tubing of square cross-section and extending between the end plates 220, is joined by spacers 224 to matching upper rails 226 also extending between the end plates. A multi-return cylinder 228 is supported at the end plates 220 by appropriate bearing assemblies (not shown). A guide carriage 230, equipped with a floating nut 232 encompasing the cylinder 228, is constrained to lateral movement by bearings 234 mounted on the carriage and riding between the rails 222 and 226. Extending from the carriage 230 is a pair of sleeves 236 (only one visible). Each of the sleeves 236 receives a leg 240 which is slidable within the corresponding sleeve as indicated by the arrow. The legs 240 may be set at a desired height by pinning the legs to the respective sleeves 236 through holes 240a in the legs aligned with holes 236a in the sleeves. The tubing guide 38 is fixed to the top end of the legs 240 and moves up and down with the legs as the latter are moved along the sleeves 236. Thus, the guide 38 may be positioned at a variety of heights as desired for convenience of operation, as illustrated in FIG. 2, or lower to achieve a low profile for road clearance, as shown in FIG. 1. The guide 38 is of standard design including rollers 38a against which the tubing 36 may bear in the vertical direction as well as additional rollers (not visible) against which the tubing may bear in the transverse direction.
The tubing reel assembly 16 is equipped with a motor drive and appropriate gear or chain linkages (not shown) in a conventional manner. Thus, the motor of the reel assembly 16 may be selectively operated to rotate the reel to take up the tubing 36 as it is extracted from the well. Additionally, a drag effect may be produced by operating the motor of the reel assembly 16 to resist the unwinding of the tubing 36 from the reel as the tubing is being injected into the well. This drag-producing operation may be used to maintain a desired amount of tension in the tubing between the reel and the injector head 40 as well as to prevent the reel from running free and unwinding the tubing at a rate greater than desired.
The motor of the reel assembly 16 is also connected by appropriate belts or chains (not shown) to the multi-return cylinder 228 to rotate this cylinder whenever the reel itself is being rotated. Thus, when the reel, for example, is being rotated to take up the tubing 36, the cylinder 228 is continuously rotated in one rotational sense thereby causing back and forth lateral motion of the carriage 230 due to the meshing of the floating nut 232 mounted thereon with the helical grooves of the cylinder. As the carriage is thus swept back and forth, the tubing guide 38 is also maneuvered back and forth relative to the reel and guides the tubing 36 accordingly. Thus, in a well known manner, the tubing 36 is wound in a level fashion on the reel 16. When the tubing 36 is being removed from the reel, rotation of the reel is accompanied by rotation of the multi-return cylinder 228 due to the linkage of the cylinder to the motor, and to the reel 16. Consequently, the carriage 230 and the tubing guide 38 are again swept back and forth across the face of the reel 16 to facilitate the removal of the tubing therefrom.
The reel assembly 16 is fitted with a fluid-seal swivel device 242 incorporated in the hub of the reel in a well known manner. With one end of the tubing 36 extending down the well, the opposite end of the tubing fixed relative to the reel drum may be secured to one end of the swivel device 242 which rotates with the reel. Then, with the tubing 36 in the well, fluids of various kinds may be introduced down the well through the tubing 36 by means of the swivel device 242.
The fluid pressure lines from the power unit 20 and the control house to the reel drive motor and the various fluid pressure devices on the mast 42 and injector head 40 have not been expressly included in the drawings for purposes of clarity. Such fluid pressure communication lines are generally conventional. However, the fluid pressure lines used in the present system may be fitted with counterbalance valves. Such counterbalance valves are known, but not heretofore employed in coiled tubing systems. The counterbalance valves function to prevent rapid loss in pressure in a cylinder when a leak or break has occured in the associated pressure line. Thus, a safety factor is added to prevent, say, dropping of the injector head, or collapsing of the mast, when such a leak or break occurs.
When the coiled tubing assembly as described herein is brought to a well to be worked, it may be generally in the configuration illustrated in FIG. 1. Thus, the injector head 40 is in its lowermost position with the mast folded. The tubing 36 may or may not be extended through the guide 38 and the injector head 40 to the tube straightener 208. In either case, the tubing guide 38 would most likely be in a retracted configuration as shown to provide necessary road clearance for transportation.
The truck 14 is maneuvered to back the flatbed 12 to the vicinity of the well. The outriggers 188 are positioned as described hereinbefore and the screw jacks 186 are lowered against the ground. With the engine of the power unit 20 operating, the hydraulic pump and pneumatic compressor are operable. The air compressor is generally utilized to operate the chain tensioner (not shown) which is part of the injector head.
Hydraulic pressure is applied to the cylinder assemblies 68 to raise the mast to its vertical operating configuration. The four swing bolts 70 are positioned and locked. The double cylinder pickup system is then lowered by extension of the outer piston rods 152a and 154a, and the two inner piston rods 156a and 158a are lowered and pinned to the clevises 168 of the vertical carrier assembly 80. The cylinders 152 through 158 are further operated to elevate the injector head 40 along the mast 42.
The blowout preventer 196 is then moved forward on its carriage 202 to a position under the elevated injector head 40 as indicated in FIG. 4. The cable or chain 206 is used to connect the blowout preventer 196 to the injector head skid base 124 and the vertical carrier assembly 80 is further elevated. With the blowout preventer suspended from the skid base 124, the blowout preventer carriage 202 is returned to its transportation position toward the control house 24. The chain drive 132 is then operated to move the injector head 40 forward until the tubing straightener 208 is directly over the well. If necessary, the left-right adjustment cylinder 128 may be operated to move the front end of the skid base 124 and, therefore, the injector head 40 and the associated tubing straightener 208 laterally to position the tubing straightener over the well. The blowout preventer 196 is fastened to the top of the well Christmas tree and disengaged from the skid base 124.
The level of the injector head may again be adjusted, if necessary. When finally set at the desired operating position, the vertical carrier assembly is secured to the mast by the latch arms 172 engaging the studs 170a.
The level wind tubing guide 38 is raised to a more convenient operating position as indicated in FIG. 2, and the tubing 36 is advanced by operation of the injector head 40 through the tube straightener 208 down through the blowout preventer 196 into the well. If necessary, the tubing is first extended from the reel 16 through the tubing guide 38 and the injector head 40 to the tubing straightener 208.
Continued operation of the injector head 40 forces more of the tubing down the well. During this procedure, the tubing meter 216 maintains a constant reading on the amount of tubing 36 that has been injected into the well. Also, the motor of the reel assembly 16 may be so operated as to properly tension the tubing leading into the injector head 40.
When the tubing end is positioned at the desired level in the well, necessary operations may be carried out through the tubing 36 by means of the swivel device 242. For example, liquids may be introduced into the well through the tubing 36 to pump mud or sand from the well. Also, pressurized gasses such as nitrogen may be injected into the well in the workover operation.
When the workover operation has been completed, the injector head 40 may be operated in the opposite direction to extract the tubing 36 from the well as the reel 16 is rotated by its own drive motor to take up the tubing onto the reel. Once the tubing 36 is clear of the blowout preventer 196, it need not be completely wound on the reel, but may be left extending through the injector head 40 and the tube straightener 208. At that point, the blowout preventer 196 may be again connected to the skid base 124 by the cable or chain 206 and raised off of the Christmas tree. The chain drive assembly 132 and, if necessary, the left-right adjustment cylinder 128 are operated to return the horizontal carriage assembly 78 and the injector head 40, with the blowout preventer 196 suspended therefrom, to the original lateral position indicated generally in FIG. 4. The carriage 202 is moved under the injector 40 and the blowout preventer 196 is positioned on the carriage and disconnected from the skid base 124. The blowout preventer and its carriage are then returned to their transportation position. The latch arms 172 are disengaged from the studs 170a and the vertical carrier assembly 80 is lowered to the flatbed 12 as shown in FIG. 3.
The inner piston rods 156a and 158a are disengaged from the clevis connectors 168 and the four piston rods 152a through 158a are contracted to return the four cylinders 152 through 158 to the top of the mast as indicated in FIG. 2. The four swing bolts 70 are loosened and swung free of the upper hinge plates 58 and the cylinders 68 are operated to lower the mast to its transportation configuration as indicated in FIG. 1.
The tubing guide 38 is lowered by allowing the legs 240 to pass through the sleeves 236 to a lower position, with the tubing 36 still passing through the guide 38 to the injector head 40 and the tubing straightener 208. The screw jacks 186 are raised into the lower mast legs 44 and 46, and the outriggers collapsed and returned to their travel positions against the lower mast legs as well. The coiled tubing assembly is then ready to be moved to the next well working operation.
It will be appreciated that the present system provides for a coiled tubing apparatus that is relatively convenient and safe to use in well working operations. The capability of lowering the injector head to the flatbed, particularly in an upright configuration, provides increased access for servicing the injector head in a safer and more convenient manner. Furthermore, the ability to fold the mast for transportation purposes without the great weight of the injector head and the associated carriage structure being suspended on the pivoted portion of the mast makes folding the mast and transporting the apparatus safer procedures. The double cylinder system of the present invention allows the cylinders to be effectively extended along the mast above the flatbed as well as to remove the cylinder assembly from the lower portion of the mast for folding purposes. Further, the double cylinder system provides greater latitude in varying the elevation of the injector head along the mast. The chain drive assembly for lateral movement of the injector head horizontal carriage platform, including the worm drive locking mechanism, allows the injector head to be moved forward and backward with relative ease. Further, the left-right adjustment cylinder enhances the degree of flexibility of movement of the injector head over the well. The blowout preventer carriage and track system further allow operations associated with the workover of wells to be carried out with greater ease and safety since the blowout preventer may now be moved along the flatbed and suspended from the elevated injector head to be positioned over the Christmas tree with little or no manhandling. Also, the height adjustment of the level wind tubing guide allows the tubing guide to be lowered for road clearance purposes while retaining the tubing intact therein and extended through to the injector head. Thus, less time is required in setting up the coiled tubing apparatus for workover operations as well as in placing the apparatus in condition for transporting on a highway.
The foregoing disclosure and description of the invention is 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.
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Disclosed is a system including two or more fluid pressure piston-and-cylinder assemblies. The cylinders are linked in pairs so that retraction of both piston rods reduces the length of the pair of assemblies to the length of a single assembly. Operation of both pistons in a pair provides an effective stroke twice the length of a single assembly stroke. In a particular embodiment, a double cylinder system is used as a pickup system for elevating equipment along a mast in a well workover rig.
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The present invention is a continuation-in-part of U.S. patent application, Ser. No. 07/946,484, filed Nov. 3, 1992, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for cooling, stabilizing and preparing melt-spun filaments.
A known apparatus for cooling, stabilizing and preparing melt-spun filaments includes means for making an annular bundle of melt-spun filaments, a blowing air dispensing means arranged in the center of the annular bundle of melt-spun filaments and a preparation application device for applying a preparation to the filaments.
Swiss Patent CH-A-667,676 discloses a porous blowing air dispensing means which is positionable in the center of an annular bundle of filaments downstream of a melt jet and which feeds gas radially symmetrically through the bundle of filaments from the interior of the bundle to the exterior. In this way, the heat from the melt jet is efficiently removed from the filaments. A preparation can thus be applied directly to the filaments underneath the blowing air dispensing means and the filaments can then be combined to form a closed bundle. Adhesions between the individual filaments do not occur.
It has, however, been shown that this known apparatus cannot be used for all cases. When spinning multifilament yarns, for example yarns made of polyethylene terephthalate (PET), with relatively high individual filament denier, in particular at spinning speeds of 2000 m/min and more, yarns are obtained which cannot be further processed in the conventional manner, in particular stretched. The stretching process is disturbed so much by the occurrence of an intolerable number of filament breakages that a yarn with adequate mechanical properties cannot be produced.
It has been shown that the multifilament yarns spun in this way have very great irregularities in their molecular structure. The values determined for the optical birefringence, as a measure of the molecular orientation, are subject to unusually great variations, both from filament to filament and along the individual filaments, and in each case cover a very wide range.
However, the requirement for regularity of continuous multifilament yarn is so high that, for example, in the case of filaments of polyethylene terephthalate, values for optical birefringence should not vary by more than 10% of the measured mean value. When stretching filaments which have more than a 10% variation in birefringence, an intolerable number of filament breakages is indicated. Moreover, such irregular filaments when present in textiles cause unsatisfactory color intensity variations during dyeing of the textiles.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus for cooling and solidifying a melt-spun multifilament yarn in such a way that the molecular orientation within the individual filaments is sufficiently uniform, preferably so that the birefringence does not vary more than 10% from a mean value, so that the melt-spun multifilament yarn is suitable for commercial applications in which it is stretched.
It is an additional object of the invention to provide an improved apparatus for cooling and solidifying a melt-spun multifilament yarn which produces multifilament yarn at a comparatively higher throughput with sufficiently uniform filaments so that it is suitable for commercial applications.
According to the invention, the apparatus for cooling, stabilizing and preparing melt-spun filaments includes means for producing an annular bundle of filaments, e.g. a spinneret assembly or melt jet; blowing air dispensing means for blowing air through the annular bundle of filaments to cool the filaments; a preparation application device downstream of the blowing air dispensing means having means for conducting air for the blowing air dispensing means through it, and a radially closed tube having open ends connecting the blowing air dispensing means and the preparation application device to conduct air fed through preparation application device to the blowing air dispensing means and to space the preparation application device from the blowing air dispensing means. The preparation application device, the radially closed tube and the blowing air dispensing means are concentrically positioned relative to each other in the annular bundle of filaments. The radially closed tube necessarily has a length of 200 to 2000 mm. The radially closed tube is hollow or has a throughgoing passage extending from one open end to the other open end which connects to a hollow interior portion or passage of the blowing air dispensing means which, in turn, is connected with means for dispensing blowing air, e.g. orifices, so that air passed through the radially closed tube issues from the blowing air dispensing means. The preparation application device can, of course, also be provided with a passage for the flowing air as the air-conducting means.
By inserting a radially closed tube between the preparation application device and the blowing air dispensing means, the distance between the blowing orifices and the preparation application device for the preparation agent is increased. This has the advantage that additional time is provided for cooling of the melt-spun filaments. This becomes more important as the individual filaments become thicker and the spinning take-off speed becomes higher. It is therefore better if the distance is increased between the spinneret and the first filament-guiding member with which the freshly spun filament comes into contact when the filament denier is larger or the take-off speed is higher. In this case, the denier which the filament has during the cooling phase is of significance.
It is advantageous when the distance between the beginning of the quenching and the place of preparation application is at least 950 mm. Since, for design reasons, the preparation application device itself extends upstream 220 mm beyond the point at which the preparation is actually applied, it has proven advantageous to provide a tube of at least 200 mm in length between the blowing air dispensing means and the preparation application device.
It is advantageous when the radially closed tube connecting the blowing air dispensing means and the preparation application means is surrounded by a conical casing tapering toward the upstream direction, i.e. away from the preparation application device and toward the blowing air dispensing means. As a result, the cooling air is directed quantitatively, continuously and turbulence-freely out of the interior of the cylindrical bundle of filaments to the exterior.
Depending on the type of polymer, the denier and the speed of the spun filament, the length of this radially closed hollow tube should be between 200 to 2000 mm, in particular between 200 and 1780 mm, preferably between 200 and 1160 mm.
Higher filament denier and higher spinning speeds require greater distances between the blowing air dispensing means and the place of preparation application than lower deniers and speeds. The same applies to substances of higher heat content. Under certain circumstances, this results in pipe lengths with which the mechanical stabilization of the cylindrical bundle of filaments becomes problematical. It is known that the longer the free bundle of filaments is, the greater is the disturbing effect of an external air flow.
Since, however, the cooling conditions require certain minimum lengths, suitable measures for eliminating, or at least reducing to a sufficient extent, the disturbing influences of external air flow must be provided. It is therefore desirable to surround the quenching device or blowing air means with a fixed casing, which in a preferred design comprises a perforated cylindrical tube or pipe which can be made from perforated plate. This cylindrical casing can advantageously extend from the lower edge of the spinneret assembly or heating collar, if there is one, to the vicinity of the preparation application device. Both at the upper end and at the lower end of this casing a predetermined spacing between the casing and the spinneret assembly or heating collar and/or between the casing and the preparation application device can be provided to create a controlled air exchange with the surroundings.
The casing is advantageously designed so that one portion of it can be swung out to the rear and another portion can be swung out to the front. The former is required to clear the required path for removal of the blowing air device or quenching air dispenser from its operating position. Thus the spinning chamber can be opened for operating personnel, for example when starting spinning, to pass the filament down from the spinning stick into the space thereunder with the draw-off apparatus.
It is expedient to provide a centering mandrel on the blowing air device which engages in a bore made in the center of the spinneret assembly. This gives the entire blowing device an additional fixing point and consequently makes it independent of the base area, which varies with varying bottom loading.
The method according to the invention performed with the above-described apparatus particularly includes controlling the product of the spinning speed v (in m/min) and the square root of the filament denier (in dtex) so that it is between 5000 and 20000, preferably between 5270 and 11000 and spacing the preparation application device a sufficient distance from the blowing air dispensing means. This has the advantage that the melt-spun filaments are given adequate time for cooling before they come into mechanical contact with the preparation application device for the spinning preparation.
According to the invention, the method of cooling, stabilizing and preparing melt-spun filaments, comprises the steps of:
a) making an annular bundle of melt-spun filaments with a melt throughput rate of not less than 1.1 g/min per filament;
b) blowing air through the annular bundle with a blowing air dispensing means located in the center of the annular bundle to form cooled filaments;
c) connecting a hollow air-conducting preparation application device to the blowing air dispensing means with a radially closed hollow tube having open ends and a length of from 200 to 2000 mm to space the hollow preparation application device from the blowing air dispensing means;
d) guiding the air to the blowing air dispensing means through the radially closed hollow tube with open ends and the hollow air-conducting preparation application device;
e) applying a preparation agent to the cooled filaments with the preparation application device to form cooled prepared filaments; and
f) controlling a spinning speed of the melt-spun filaments and a filament denier of the melt-spun filaments so that the product of the spinning speed and the square root of the filament denier is between 5000 and 20000 (m/min dtex 1/2 ) to produce the cooled prepared filaments with a birefringence not varying from a mean value by more than about 10%.
BRIEF DESCRIPTION OF THE DRAWING
The objects, features and advantages of the present invention will now be illustrated in more detail by the following detailed description, reference being made to the accompanying drawing in which:
FIG. 1 is a schematic partially cross-sectional, partially side view of one embodiment of an apparatus according to the invention;
FIG. 2 is a schematic side view of one portion of an alternative embodiment of an apparatus according to the invention; and
FIG. 3 is a graphical illustration of the relationship between the birefringence range of the melt-spun filaments produced by the method of the invention using the apparatus shown in FIG. 1 versus melt throughput per filament for two lengths of the radially closed tube separating the blowing air device and the preparation application device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, the reference numeral 1 denotes a spinneret assembly, the means for making the annular bundle 3 of melt-spun filaments, which is arranged within a heating collar 2. The spinneret assembly 1 and the heating collar 2 are surrounded by an insulation 15. A porous blowing air dispensing means 4, which is hollow and cylindrical in the embodiment shown in FIG. 1, is connected gas-tightly to a hollow radially closed tube 5 which has open ends 5', 5" and which is radially closed and of approximately the same diameter over its entire length. The blowing air dispensing means 4 can be provided with a plurality of throughgoing orifices through which air can stream from its interior to its exterior and through the annular bundle 3 of filaments. The blowing air dispensing means in this embodiment is the blowing air dispensing means 4.
A hollow annular preparation application device 6 for applying a spinning preparation to the filaments is arranged concentrically at the lower end of the radially closed tube 5 and has a passage through it to conduct air for the blowing air dispensing means. The blowing nozzle 4, the radially closed tube 5 connected to it and the hollow, air-conducting preparation application device 6 at the lower end of the tube 5 are carried by a tube cone 9, which is movable, e.g. pivotable, in a way not shown in the drawing. The tube cone 9 is hollow or has a connecting passage connected to the radially closed tube 5 with open-ends 5', 5" so that blowing air can be fed through the tube cone 9 into the interior of the radially closed tube 5 from where it flows into the interior to the blowing air dispensing means 4 to be dispensed through the orifices which have not been shown in detail. The tube cone 9 is further movably connected to the housing via a narrow hollow radially closed connecting pipe 10 also with open ends and subsequently connected to the radially closed open-ended hollow tube 11. The air for the blowing perforated blowing air dispenser tube is fed to the hollow tube cone 9 through the air-conducting tube 11 and the connected air-conducting pipe 10. The entire device which provides the air for cooling the filaments including the blowing air dispensing means 4, the radially closed tube 5, the preparation application device 6 and the tube cone 9 is arranged so that it can be moved completely out of the filament path. Of course a source of pressurized air or pump for supplying the cooling air must be connected to the closed hollow tube 11 to feed the air into it, but that air supply means has not been shown in the drawing.
A mandrel 12 is provided at the upper end of the blowing air dispensing means 4, which engages in a corresponding bore 13 in the center of the spinneret assembly 1 in the operating position of the apparatus. A spinning tube 8 is arranged concentrically under the tube cone 9. A convergence device 7 is attached at the upper end of the spinning tube 8 and brings the filaments together. The blowing air dispensing means 4, the radially closed tube 5 and the preparation application device 6 are surrounded by a casing 14 in operation, which in a preferred design is a perforated cylindrical casing formed from a perforated plate. In another embodiment shown in FIG. 2, the radially closed tube 5 is enclosed in a conical casing 16 which extends up to the preparation application device and improves the air flow around the bundle of filaments.
If it is technically possible, the blowing air dispensing means 4 is also extends up to the spinneret plate. Furthermore, for the purpose of a controlled air exchange with the surroundings, both at the upper end and at the lower end of the casing 14 a defined distance from the spinneret plate or heating collar or from the preparation application device is provided.
In operation, the blowing air dispensing means 4 is supplied with the required cooling air via the open-ended hollow tube 11, the radially closed open-ended hollow pipe 10 connected with the air-conducting tube 11, the hollow tube cone 9 connected with the pipe 10, the hollow preparation application device 6 and the radially closed open-ended tube 5. The cooling air, which flows through all the foregoing air-conducting components connected with the blowing air dispensing device, escapes radially symmetrically from the porous blowing air dispensing means 4. The flow of air is shown in FIG. 1 by arrows 21. The preparation application device 6 is supplied with a suitable spinning preparation via a preparation inlet tube 33 connected to it, which passes through the pipe 10 and tube cone 9 as shown in FIG. 1.
The polymer melt to be spun is discharged in a known way through spinneret bores arranged in concentric circles in the spinneret assembly. First it passes by the heating collar zone 2 in free fall and then passes into the region of the blowing air dispensing means 4, where it is cooled by the emerging cooling air and solidified to form a cooled bundle 3 of filaments.
After passing through an additional zone, defined by the radially closed tube 5, the filaments 3 are provided with a spinning preparation by means of the preparation application device 6. Subsequently, the individual filaments are united conically with the aid of the convergence filament guide 7 to form a closed bundle 3' of filaments and fed through the spinning tube 8 to the filament take-off device (likewise not shown).
The methods of the invention are explained with reference to the following examples and results listed in the table hereinbelow. These examples describe the use of the apparatus of the invention for cooling melt-spun filaments made of polyethylene terephthalate.
EXAMPLE 1
Polyethylene terephthalate granules having a solution viscosity of 114 units, determined in accordance with ISO Standard No. 1628/5-1986 (E), were melted in an extruder and spun into a multifilament at a melt temperature of 289° C. through a spinneret having 128 bores arranged in two concentric circles.
The emerging melt was cooled by the central quenching according to the invention, using 600 cbm/h of air at 35° C. The blowing air dispensing means 4 was 530 mm long with a diameter of 95 mm. The radially closed hollow tube 5 between the blowing air dispensing means 4 and the application apparatus 6 for the preparation had a length of 200 mm and fed blowing air to the blowing nozzel 4 from which it issues radially to the filaments. Accordingly, the place for the application of the preparation was 420 mm below the blowing air dispensing means.
The solidified multifilament was taken off from the spinning chamber at a speed of 3100 m/min. The melt throughput was chosen so that the individual filaments had a denier of 3.6 dtex. The values for optical birefringence measured on this multifilament were in the range between 0.048 and 0.053, i.e. a size range of 5×10 -2 . The molecular orientation of the multifilament was consequently satisfactory for further processing.
EXAMPLES 2 to 4
Polyethylene terephthalate as in Example 1 was spun and cooled in the same way. However, in the case of these examples the length of the tube 5 was 1160 mm, i.e. the application device 6 for the spinning preparation was 1380 mm below the blowing air dispensing means. The melt throughput per spinneret bore was varied in such a way that, at a drawing-off speed of 3100 m/min, multifilaments resulted. The individual filament denier varied from one example to another from 4.5 and 11.5 dtex. In the case of these multifilaments as well, the values for the optical birefringence were within a narrow range of 0.006 units.
EXAMPLE 5
Polyethylene terephthalate was spun as in Example 1 and cooled and solidified under the same conditions. The length of the tube 5 was 200 mm. The take-off or spinning speed was at 2000 m/min. The melt throughput was chosen in such a way that a multifilament of 8.5 dtex individual filament denier results. The values for the optical birefringence found for these filaments were within a range between 0.024 and 0.045.
EXAMPLE 6
Polyethylene terephthalate was spun, cooled and solidified as in Example 1. However, at 3100 m/min, a multifilament of 5.6 dtex individual filament denier was produced. In this case, values for the optical bi-refringence which were within a range of 0.048 to 0.110 were found.
The test results of the examples are compiled in the following table.
TABLE__________________________________________________________________________Filament Birefringence Range versus Melt ThroughputExample No. 1 2 3 4 5 6__________________________________________________________________________Spinning speed, [m/min] 3100 3100 3100 3100 2000 3100Filament denier, [dpf] 3.6 4.5 8.8 11.5 8.5 5.6Melt throughput, [g/min/fil] 1.1 1.4 2.7 3.6 1.7 1.7v-SQR, (dpf) 5881 6576 9196 10513 5831 7336Tube length, [mm] 200 1160 1160 1160 200 200Distance between blowing air 420 1380 1380 1380 420 420dispensing means andpreparation, [MM]Birefringence × 10.sup.3min 48 50.1 51.1 48.8 23.9 48.3max 53 55.6 55.6 55.1 45.8 110.2__________________________________________________________________________
Filaments according to Examples 1-4 can be further processed, in particular stretched, satisfactorily. The range between the maximum and minimum birefringence values of the filaments is about 10% of the mean value. In the case of the filaments according to Examples 5 and 6, an intolerable number of filament breakages occur during stretching and the range of the birefringence greatly exceeds 10% of the mean value, in fact is about 100% in the case of example 6.
These results are shown graphically in FIG. 3. The birefringence ranges for examples 2, 3 and 4 are connected by one straight line which indicates that in these experiments the tube length is always 1160 mm, while the results for examples 1, 5 and 6 are connected with another line indicated that the tube length is the same and equal to 200 mm. It is particularly surprising that good results can be obtained at a melt throughput of 3.6 g/min per filament (denier 11.5 dtex) with a spinning speed of 3100 m/min.
With the apparatus according to the invention, success has been achieved for the first time in producing filaments from PET at speeds of 2000 m/min and more with a filament denier of up to 11.5 dtex which are so regular that they can be further processed without any trouble.
The method according to the invention can be carried out with all known thermoplastic polymers, in particular with polyesters such as polyethylene terephthalate, polyamides such as polycaprolactam, polyhexamethylene adipamide and similar polyamides used in the textile sector, polyethylene, polypropylene and related polymers, polyacrylonitrile etc. It should be noted here that in case of applications of the invention for other polymers radially closed tube lengths of up to 2000 mm may be required.
While the invention has been illustrated and described as embodied in an apparatus and method for cooling melt-spun filaments, it is not intended to be limited to the details shown, since various modifications may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed is new and desired to be protected by Letters Patent is set forth in the appended claims.
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The apparatus for cooling, stabilizing and preparing melt-spun filaments includes a spinneret assembly for producing an annular bundle of filaments; a blowing air dispensing device downstream of the spinneret assembly and centrally located in the annular bundle for cooling the melt-spun filaments; a hollow, air-conducting preparation application device located centrally in the annular bundle and downstream of the blowing air dispensing device; a radially closed hollow cylindrical tube having open ends and connecting the blowing air dispensing device and the preparation application device to conduct air flowing through the preparation application device to the blowing air dispensing device and having a length of from 200 to 2000 mm and a controlling device for regulating the spinning speed and filament denier so that the product of the spinning speed and the square root of the filament denier is between 5000 and 20000 (m/min dtex 1/2 ) to produce cooled prepared filaments with a birefringence not varying from a mean value by more than about 10%.
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CROSS REFERENCE TO RELATED APPLICATIONS
Reference is made to and priority is claimed from U.S. Provisional Patent Application Ser. No. 61/217,326 filed May 29, 2009 the disclosure and contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to jewelry and more specifically to jewelry containers and in particular to an adaptable/adjustable jewelry container for cremation ashes, DNA material, soil and like substances and materials.
BACKGROUND
Jewelry cremation containers are disclosed for example in U.S. Pat. Nos. 5,158,174 and 5,208,957 to Hereford and U.S. Pat. No. 5,755,116 to Sparacino. Hereford discloses a cremation jewelry container with a minor container and a major container to be combined to create a pendant which could hold multiple samples for example from different donors. The minor container in Hereford is described and illustrated as a cylinder tube which is closed at its bottom with an open cavity to allow cremated ashes to be placed inside, before being closed by a cap which possesses a flat surface which exceeds the outer circumference of the minor tube and is basically illustrated in FIG. 3 as a bigger sleeve cylinder section ( 20 ), with a smaller sleeve and cap ( 40 ), which fits into the larger cylinder ( 20 ). The cap is larger than the inside dimension of its companion sleeve or tubing. The major container is described as decorative, in pendant style, which will act as a housing unit for singular or multiple minor containers. Hereford provides a piece of jewelry with a singular purpose, which is to hold minor containers. Although stylish, it requires both containers to complete the Hereford's intended desire to secure the cremated ashes in a fashionable apparatus. The minor container does not seem to have an identity independent of the major container.
Sparacino discloses that two similarly sized and dimensioned cylinder or flange designed components will comprise its cremation container. They will slip over each other to form the completed container. It will be threaded or the use of a silicone sealant will secure ashes or other material within its cavity. The cavity compartment will permit the deposit of multiple samples, such as cremated ashes, a lock of hair, or tooth, as a few illustrations of deposits separately housed with the container. Sparacino also describes placing said container within another hollowed out piece of jewelry, with two reflective matching parts; such as but certainly not limited to a locket device commonly seen in the jewelry industry, or some other style piece with two halves. The completed container can then be placed and hidden within said piece and sealed together with silicone sealant. Sparacino also describes the use of decorative marking, jewels, and etched information being placed on the front and back covers to enhance the commemorative value of the container to the user
The present invention differs from both Hereford and Sparacino on many different levels. One of the differences is both the Hereford and Sparacino containers are designed to hold multiple samples. In contrast the present invention possesses a singular chamber 8 for use in holding a definitive sample as described herein. Multiple samples could only occur by incorporating multiple containers or contaminating the cavity with multiple items for deposit. Therefore for a woman who may have lost her husband, and child and got married on the beach in St. Thomas; she would have to place each sample of corresponding material into its own container. Then each container could be soldered behind a specific independent piece of jewelry, or in the case of a written charm, placed top, bottom and sides, either in a row or scattered about the piece.
In one example, the adaptable/adjustable jewelry container embodying the present invention is configured to function as an independent piece of jewelry as shown for example in FIG. 5A , FIG. 5B and FIG. 5C , to provide the possibility of different and distinct samples sharing the same environment, such as but not limited to, a charm bracelet or necklace will allow for the adaptable jewelry containers to be present in the same general area. In another example, the present invention is configured as giftware to provide separate but multiple containers that may share the same frame as shown for example in FIG. 10 , plaque plate FIG. 11 or other forms of giftware, by drilling additional holes or receptacles for the containers to then be secured with an appropriate form of adhesive.
A further difference between the Hereford and Sparacino is in the ability of the present invention to adapt and accent another independent piece of jewelry or giftware, while still remaining visible to the eye, and not compromising the aesthetic design intended by the original piece of jewelry FIG. 4A , FIG. 4B , FIG. 4C . This is accomplished on multiple levels within the design of the present invention, and particularly in its ability to change its shape and size, as well as the total depth of the jewelry container, while maintaining its principles of design, makes it possible to fit into, on top of or alongside of, almost any piece of jewelry or giftware item FIG. 9 . The adaptable jewelry container can also mimic the design of the original item, such as but not limited to, diamond cutting the top or bottom caps, or adding a single or multiple diamonds. It can also be accented with colored stones and engraving of symbols, initials, hearts, crosses or some other ornamental design to enhance the original design. Although Sparacino makes reference to the possible use of etched information, and jewels and decorative markings to enhance the commemorative value of its container, the container's explicit design is to be concealed within another piece of jewelry which makes it symbolic and not ornamental. Both Hereford and Sparacino keep the container holding the ashes hidden and do not accent or enhance the designs in which they are being placed.
A yet further difference between both the Hereford and Sparacino containers and the present invention for an adaptable and adjustable design for holding the cremated ashes of animals, humans, or other species, as well as the possibilities of different forms of soil/sand in an airtight container, is in its basic design. Hereford and Sparacino both rely on the concept of a cylindrical bottom with its cap already in place. The top in the Sparacino design uses a similar sized top flange or cylinder to be secured with silicone. Hereford uses a larger flat plate on a tube or cork, which then slips into the opening of its bottom minor container counterpart. In contrast, when the present invention takes its shape, such as but not limited to, oval, pear, marquise, star or square, the bottom of the present invention's base is open with thicker walls than its top, to allow for any minor adjustments in height and cavity size to conform and accent another item. The top cap 14 and bottom cap 16 are solid in the present invention, and have no tubing attached to assist in effectively closing the containers chamber, as both the Hereford and Sparacino designs incorporate. The present invention instead uses a design bezel recessed top base 12 and a solid top cap 14 with a slight tapering 15 from its top surface to bottom surface, which is arranged to sink down and rest snugly to the larger opening. The solid top cap 14 is also arranged to rest on the ledge 7 created by the making of the bezel. The bottom cap 16 is also solid, but smaller than the top to seal narrower opening at bottom of base 12 . Each end cap, depending on the material in which it is made, may be sealed by any suitable means, such as, for example, laser or conventional soldering, or generous use of a suitable adhesive to carry out the intended function.
Another difference between the containers disclosed by Hereford and Sparacino and the present invention, is that with simple modifications, while keeping true to the initial designs concept, the adaptable jewelry container may be configured to function as an independent piece of jewelry FIG. 5A , FIG. 5B , FIG. 5C , FIG. 6 and FIG. 7 , will be accomplished for example, with the addition of a loop or loops being placed on the base part of container. When one loop is added to the center of the base, FIG. 5A , FIG. 5B , FIG. 5C , FIG. 7 , it will require either a bale or jump ring, so that the container can swing freely on a chain or bracelet. When adding multiple loops, such as in three, FIG. 6 but not limited to these restrictions or numbers, the adaptable jewelry container will replace the junction between the two strands of beads and the beads and cross in a set of rosary beads. The top cap can then be made ornamental with engraving, addition of diamonds or genuine or synthetic stones, or by using a standard size religious charm to replace the top cap, which will fit at top of bezel base and act as a substitute for sealing the top of the container. Neither Hereford nor Sparacino possess this capability. Both Hereford and Sparacino require some outside device to encase either their minor container as disclosed in Hereford or major container as disclosed in Sparacino which then transforms the major or minor container into a co-dependent piece of jewelry.
A further difference between the present invention for a jewelry container which can secure the cremated ashes or DNA or earthly material within its chamber, is its ability to be manufactured in materials other than those mentioned in either Hereford or Sparacino. The Hereford and Sparacino containers are limited in their claims to the field of metals, and would not be practical or in some cases possible to produce in other materials. In the case of the Hereford design, the minor container would pose a problem, as its cap has to be soldered, while its major container, after inserting the minor container, might be possibly sealed with silicone, as soldering is not an option in either plastics or wood. Sparacino calls for two threaded or overlapping two part flange or cylinders. Although this might be possible in plastics, but not disclosed, it still falls short of a successful design, when having to be encased within another two separate piece hollowed design, with only the use of silicone to secure and align all three pieces. The three pieces previously mentioned would be the completed container and two separate outer designs mentioned. Therefore the containers in Hereford and Sparacino could not be produced in woods and plastics. This present invention for an adaptable jewelry container, works with the same design functions regardless of the material from which it is ultimately produced and still retains its ability to adjust its height before sealing cremated ashes, DNA or other mentioned materials, by means of adjusting the bottom of the base before sealing with the bottom end cap
SUMMARY
A jewelry container, which can store inside a single chamber the cremated ashes or DNA of animals, humans, and any other species known to man is disclosed. There could also be the possibility of placing soil or sand within its cavity. This invention will provide an airtight container which could adapt itself to another object or piece of jewelry. Accenting and enhancing the original piece, while proving a safe environment for the contents. Altering its shape and sizes allows for the adaptable/adjustable jewelry container to blend or hide behind separate jewelry items used as its compliment. It will also function in different shapes and sizes, as an independent piece of jewelry in its own right FIG. 5A , FIG. 5B , FIG. 5C and FIG. 7 . It will also be featured in its own line of designs, with the bottom cap and bottom base pre-molded to each piece designed, examples being but not limited to, crosses FIG. 8A , hearts FIG. 8B , stars FIG. 8C , religious symbols and animals. The adaptable jewelry container will be manufactured in various materials to provide a cost which can be comfortable to all markets and users.
The common bond between all these samples is that they all represent the sentimental entities which inspire thoughts of love and comfort to the user. Having a special moment or thought represented by a unique piece of jewelry has been a custom pasted down through many generations. Having a grandmother's charm, ring or bracelet given to the first born girl in the family was established centuries ago and still practiced to this current time. The need for a physical connection to the people, pets and memories that hold significance in our lives, has in many instances, been represented through furniture, pictures and jewelry, and gives a sense of connection to one's past and a positive feeling of transferring these special moments to future generations. This invention's ability to be added to a special charm, bracelet, necklace, pendant, ring, money clip, or key ring, owned by the user, ties the past to the future. This capability provides a means of securing the cremated ashes or other material, in a manner and versatility not previously disclosed or known hereto.
An adaptable/adjustable jewelry container to secure the remembrance of cremated ashes or DNA of any species, or a sample of dirt or sand in a single airtight chamber is disclosed. The unique attributes of this invention, is in its ability to be added to and accent or enhance almost any secondary piece of jewelry, such as but not limited to, written charms FIG. 4A , regular open back charms FIG. 4C and pendants FIG. 4B , and money clips. A slight modification, by means of a strategically placed jump rings or loops 11 , allows it to act as an independent container FIG. 5A , FIG. 5B , FIG. 5C , capable of holding above mentioned remembrances, so they can then be placed on a chain, necklace, or charm bracelet in a free moving manner, or be used as a main component of rosary beads. These are just a few of its potential uses, but in no way limiting its future possibilities.
In one example, the adaptable/adjustable jewelry container of the present invention is comprised of a bezel designed base 12 , which possesses a larger top opening with thinner side walls 6 and extends down and stops, to create a ledge 7 within the base 12 . The bottom walls of base 12 is thicker than top walls forming the chamber 8 , and the opening smaller, so there can be no mistake, no matter what shape or size of the adaptable/adjustable jewelry container, which is top or bottom of base 12 . The base 12 will be sealed with solid end caps with an appropriate thickness to allow for setting of stones, engraving or other means of ornamentating its surface. The top cap 14 will be larger by design, and to fit snugly to inside bezel dimensions and be of such thickness to meet or extend slightly above the lip of bezel wall 6 . In most but not all cases, the top cap 14 will be secured to the base 12 first, so that any adjustments in height FIG. 2A , FIG. 2B , can be made before one of the above mentioned materials are placed in chamber 8 . The bottom cap 16 will be made the same thickness, although smaller in size so that it can snugly slip inside to adjust the height of container. The seal created by the same shape end caps will provide an airtight seal. The final step to assure a safe and reliable seal will be attained with laser or conventional soldering, or depending on materials used to create the container, an appropriate adhesive agent. These end caps in certain shapes, such as but not limited to, oval, round and square, may be replaced with a religious or common charm, to secure one or both ends.
The adaptable/adjustable jewelry container will generally but not necessarily be produced in metals related to the jewelry industry, such as but not limited to, all colors and karat weight of gold, silver and platinum. In the gift line area of production, the adaptable jewelry container might be made in brass, stainless steel, titanium, plastics, resins, and a variety of woods.
In certain cases to either mass produce or create a cleaner surface for the containers' overall appearance, either top cap 14 or bottom cap 16 may be pre-assembled or molded to its corresponding base 12 . While the end cap remaining will be used to secure the chamber once cremated ashes, DNA, or other material is placed within the chamber 8 of the container.
The description herein refers to possible variations of this new invention for an adaptable/adaptable jewelry container, and is in no way to be seen or to be limited to these described examples. The examples are illustrated to show the unique and varied ways for this inventions practical uses within the context of the jewelry industry and the users needs to contain a treasured remembrance of something or someone of significance in their life.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features, advantages and benefits of the present invention will become readily apparent from the following description taken in conjunction with the drawings wherein:
FIG. 1 is a exploded view showing the three parts that comprise the adaptable/adjustable jewelry container 10 in its round shape which may be made in various sizes, 2 mm and larger. The top cap 14 (reversed to show tapering 15 ) which is slightly smaller at bottom, so that it fits snugly when resting on the ledge 7 . The bottom cap 16 which is smaller in size than top cap 14 is made in this manner to accommodate the thicker bottom walls, which extend from the ledge 7 to the end of the base 12 .
FIGS. 2A and 2B shows the bottom of side view of base 12 , broken lines 2 to illustrate one of many possible positions where the base can be adjusted in height and cavity size to better adapt to its environment.
FIGS. 3A and 3B shows examples of possible other shapes 12 ′, 12 ″ the container may assume such as, oval and pear shape, but not limited to these only.
FIGS. 4A , 4 B and 4 C illustrates some examples 4 A of a written “Love You”, 4 B Heart Charm, 4 C Rabbit Charm, and how the adjustable/adaptable jewelry container 10 of the present invention may be used to accent and enhance a separate piece of jewelry. Although these illustrations show only one of many positions the container 10 may be placed.
FIGS. 5A , 5 B and 5 C are examples of how the adaptable jewelry container 10 with the modification of adding a loop 11 in center of base, and increasing its size, can act as an independent piece of jewelry.
FIG. 6 shows an example of how by adding three loops, one bottom center 32 , and two top 32 and equally apart on the base 12 , the design will mimic the intersected ornamental bottom of a set of rosary beads that connects the beads to the cross.
FIG. 7 shows how a religious medal, or other similar shaped designed top, with marking significant to user, in this case but not limited to, round or oval, could be used to replace top cap 14 .
FIGS. 8A , 8 B and 8 C shows examples of possible designs which will include two of the pieces of jewelry container comprising of the base 12 and either bottom cap 16 , or top cap 14 , already attached to jewelry, so that only top or bottom cap will be needed to seal container in manufacturing. This does not in any way reflect the full scope of line being created, or limit the rights and ability to use other shapes as possible replacements for round design shown attached.
FIG. 9 shows a wooden paperweight and pen set with a golf motif, adapted to hold the design for an adjustable/adaptable jewelry container of the present invention, by sinking the container 50 into the wooden base.
FIG. 10 shows how a simple picture frame may be modified to hold adjustable/adaptable jewelry container 10 of the present invention.
FIG. 11 shows an alternate way of attaching the container 10 , first onto a plate that can be engraved, then placed onto picture frame or plaque after drilling a hole into material the same size as container 10 .
FIG. 12 illustrates an example of how the container 10 can be placed and attached to traditional basket settings of different shapes and dimensions.
DESCRIPTION
The adjustable/adaptable jewelry container was invented to preserve the memory of a special moment, such as but not limited to, the sand from the beach in St. Thomas, where a couple was married, or the soil from the footprint of the twin towers, or a plot where a loved one was buried, or the cremated ashes or DNA of a cherished pet or family member. It can also be attached to a special charm given by the deceased, or added to any other item which creates a bond between the contents of the container and the owner.
The present invention is a design for a three-part adaptable and adjustable jewelry container where two or more parts will be used to complete the container, and allow the cremated human, animal, or other species ashes, DNA material or soil to be placed within an airtight apparatus. The completed container 10 will then be attached to another piece of jewelry or giftware. Whether in plain frontal visual sight, as in but not limited to, a written “someone special” or “I love you” charm FIG. 4A , or in some instances may be attached on top of a heart, cross, or calendar charm while in other cases may be soldered and affixed to the back of almost any open backed charm FIG. 4B common in the jewelry industry.
The adaptable/adjustable jewelry container will also function independently when completed in various shapes and sizes known to be common in the jewelry industry, some of which shapes are, but not limited to, round FIG. 7 , oval FIG. 5A , pear shape FIG. 5B , marquise, square, star FIG. 5C and heart designs, which may be modified with a loop/jump rings 11 attached to the container, so that a bail for necklaces and pendants, or another loop/jump ring, will allow the adaptable/adjustable jewelry container to be placed onto a bracelet of various styles know in the jewelry industry. Ornamental designs maybe placed onto both the bottom and top caps. Engraving of initials, FIG. 5A and dates, as well as symbols such as eternity, infinity, cross or hearts will also be possible with this design. It is also contemplated that diamonds and other stones can be set into both the bottom cap 16 and top cap 14 .
In an illustrative example the present invention uses three pieces FIG. 1 to construct an adaptable/adjustable jewelry container which will adjust by means of size, shape and height FIG. 2A to FIG. 2B and be used to store the cremated ashes or DNA of either human, animal or other species, as well as soil or sand, in a sealed airtight manner which will protect the enclosed sentimental material. Once the container is complete 10 , it will be attached to another independent piece of jewelry or giftware.
The container's main component is comprised of a base 12 , which has a bezel design top, which by nature in the jewelry industry is recessed with a larger opening 6 to allow for the top cap 14 to sink down and be held by the ledge 7 . The bottom and corresponding opposite end of the base, has a smaller opening, with thicker walls which match the overall dimensions of the chamber 8 , which starts at the ledge 7 . This feature will permit the base to be modified in height before the container is closed and secured with bottom cap 16 .
The top cap 14 will be larger than the bottom cap 16 because of the opening on the bezel end of base will have thinner inside walls 6 , with a larger circumference. The top cap 14 will be made thick enough, to at least reach the top of the bezel end side walls 6 , or to slightly extend past said wall. The top cap 14 and bezel end of base will then be secured by either soldering or adhesive, depending on the material which ultimately identifies the jewelry container. These two pieces will create a single chamber 8 or storage unit. When using most metals know to man, this process will be done by means in the jewelry industry associated with soldering, both laser and conventional. When the container is produced from plastics, wood or some other material not previously mentioned, the procedure of securing the top cap 14 and bottom cap 16 will be attained by means of a suitable adhesive to carry out the intended function.
Another example of this invention will have both ends of the base container mirror the opening of its opposite end and which will incorporate the larger bezel design features at both ends of the base or the smaller bottom. In this example the two caps will be the same size. This variation of the invention will allow for the front and back caps to be replaced with ornamental caps FIG. 6 and FIG. 7 , which may include, but not restricted to, a different religious saint or symbol at each end of the base, so the symmetry of the two caps would visually be more esthetic when made in the same size.
The top cap 14 and the bottom cap 16 , no matter their size, along with the base 12 , in examples stated above, will create a single chamber or storage unit. When using most metals known to man, this process will be done by means in the jewelry industry associated with soldering, both laser and conventional. When the container is produced with materials which cannot be subjected to heat, such as but not limited too, plastics, wood or glass, the procedure of securing the top cap 14 and bottom cap 16 will be attained by means of a reliable adhesive. Adhesive will also be used in examples when sample in containers is sensitive to heat, or if being assembled for immediate use or delivery.
The top cap 14 and bottom cap 16 will match the shape of the base unit FIG. 3A , FIG. 3B , FIG. 5C and will fit with minimal to maximum resistance into their respective openings. In one example of the invention the top cap 14 and bottom cap 16 will form a seal without the use of solder or adhesive into their respective openings, by tapering the edge of one side of the top cap 14 and bottom cap 16 ( FIG. 1 ) to form a variation of a compression fit, so that when tapped by a hammer or pressed with some force will secure contents before final phase of closure is completed.
The bottom or non-bezel portion of the base 12 will be adjusted in height FIG. 2A , FIG. 2B by means of cutting with a saw blade, filing, or using grinding wheel or other suitable means. The forming of this design feature does not need to be to perfect, as any uneven excess metal or material will be removed after the chamber 8 is filled and the smaller base cap 16 is secured by means of above stated methods of closure. The completed container 10 will then be attached or placed onto another item of jewelry FIG. 4A , FIG. 4B , FIG. 4C or giftware FIG. 9 and FIG. 10 to give the appearance of a new unique piece of jewelry. The adaptable/adjustable jewelry container will in most cases when using metals, be attached by means of laser or conventional soldering, someplace on, behind or around edges of converted jewelry.
The flexibility of this container, is depending on its size and shape, such that it can be incorporated to appear as if it is an extension of the original piece of jewelry, or hidden behind the exposed backside of most charms, and rings, or on top of bracelets and in front, sides or back of pendants.
The adaptable/adjustable jewelry container may be made in sizes and shapes that are common in the jewelry industry. Although a round container is discussed above, it is in no way limited to such a shape restriction. The round adjustable jewelry container will have the versatility to be made in sizes from 2 mm to 70 mm or larger. It will also be made in oval, marquise, pear shape, square, emerald, star and heart shape, as well as other shapes not mentioned but deemed recognizable in the jewelry industry. These different shapes will also be made in various sizes, and will conform to the same parameters as stated above whereby the shapes will possess a base 12 , 12 ′ 12 ″ with a top bezel design, which will accommodate a larger same shape top cap 14 and smaller same shape bottom cap 16 , so that the height can still be adjusted to suit the independent piece. These different shapes will include but not be limited to, the standard dimensions found to be common in the jewelry industry.
The adaptable/adjustable jewelry container 10 as discussed above, should be arranged to have a top cap 14 and bottom cap 16 of different dimensions, and be made thick enough to accommodate the addition of diamonds, other stones, deep engraving, creative designs, such as an infinity, eternity, cross, or heart, but not solely restricted to these designs. The top cap 14 and bottom cap 16 may also be substituted with a conventional religious FIG. 7 or specialty charm ( FIG. 9 ) 50 that conforms to the dimensions and parameters of its corresponding base.
In another example, the adaptable/adjustable jewelry container of the present invention can also function independently when completed in larger sizes FIG. 5A , FIG. 5B , FIG. 5C , and FIG. 7 , to form its own identity. Depending on the shape and size of the container 10 , and the addition of one or more loops 11 or bale, the container can swing freely on a chain or charm bracelet. While with the modification of three loop/jump rings 32 , two placed evenly apart at top of oval or other shaped design and one center bottom, the adaptable/adjustable jewelry container will form the focal point of a line of rosary beads FIG. 6 whereby the top or bottom end caps may be replaced with religious medals or other ornamentation. These examples are not to be taken as the only modifications of the basic design which would create new versatile lines of jewelry.
When the adaptable/adjustable jewelry container is being used in an exclusive line of jewelry, such as, but not limited to, crosses, hearts, stars, animals, written charms, or regular charms symbolizing sea, plant, islands or other locations or sports, the base 12 with smaller bottom opening closed with bottom cap 16 , will be incorporated into the mold or die cast to make it easier and neater to manufacture jewelry with the partial container already placed in its desired location. FIG. 8A , FIG. 8B , FIG. 8C During this method of assembly, the top cap 14 will be secured after the material, whether cremated ashes, DNA, soil or other earthly materials such as sand, are placed in the open chamber 8 .
The adaptable/adjustable jewelry container can be manufactured in any metal, such as but not limited to, all colors and karat weight of gold, silver or platinum, as well as brass or stainless steel and titanium. It may also be manufactured in all colors and types of plastics and resin products, as well as different types of wood.
When the adaptable jewelry container is produced in wood, plastics or some other unmentioned material, the top cap 14 and bottom cap 16 will be sealed with a premium adhesive to secure the enclosed material in the container's chamber 8 . Some, but not limited to, uses for this type of assembly will be when incorporating this design in plaques, trophies, frames, paperweights, and costume jewelry. The adjustment in the depth of the cavity at the smaller bottom will still be possible in these materials.
There may be times during manufacturing large quantities, where either the top cap 14 or bottom cap 16 will be pre-assembled or molded to its base counterpart for purposes of efficiency and to produce a cleaner product.
It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention and are not to be construed as limitations of the invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the scope of the invention and the appended claims are intended to cover such modifications and arrangements. Further, the invention contemplates all embodiments that may be inferred directly or indirectly from the disclosure and drawings whether or not expressly stated and claimed.
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A three part adaptable/adjustable jewelry container is presented for saving and preserving a small sample of ashes or other form of DNA material from either human or animals. The container may vary in size and shape to modify and enhance another separate piece of jewelry and may be attached by means of soldering the container, once completed, to the front, back, top, bottom or sides of the charm, bracelet, necklace, or ring, or other style of jewelry accompanying the container. The container can also be adjusted in height which will reduce the cavity where the ashes or DNA are kept, before the bottom cap is secured, to provide an air and water tight seal to insure the safety and integrity of the enclosed material. This will allow the completed container to accent and blend better with its other jewelry component, or in the case of standing alone as an independent piece of jewelry, the ability to lay flatter to the wearer.
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This application is a division of application Ser. No. 06/322,109, filed Nov. 16, 1981 now U.S. Pat. No. 4,356,059.
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to a method and apparatus for manufacturing a bulky, soft and absorbent paper web.
2. Description of the Prior Art
U.S. patent application Ser. No. 933,203 Hulit, et al., filed Aug. 14, 1978, relates to a system for producing a bulky, soft and absorbent paper web using mechanical means to predry the web. The structure for predrying the web includes a papermaker's felt and imprinting fabric of a specific character and a pair of opposed rolls creating a compression nip defined by the fabric and felt through which the web is passed and partially dewatered. According to the aforesaid application, the web prior to entering the fabric-felt compression nip is essentially uncompacted and the fabric-felt arrangement comprises the initial predrying stage in the system. Since the imprinting fabric then carries the predried web in undisturbed condition to a Yankee dryer or other component defining a heated drying surface, the only significant compacting of the web that occurs in the system of the aforesaid application is at the location of the compaction elements or knuckles of the imprinting fabric. As a consequence, a soft, bulky and absorbent sheet is produced through use of the system covered thereby.
U.S. patent application Ser. No. 280,752, R. E. Hostetler, filed July 6, 1981, also relates to a system for producing a bulky, soft and absorbent paper web. In accordance with the teachings of this latter application a wet web of principally lignocellulosic fibers is positioned on a first dewatering felt and then conveyed by the felt through a first nip formed by it and a second dewatering felt to remove water from the web. The partially dewatered web is then conveyed to a second nip formed between a dewatering felt and an open mesh imprinting fabric formed of woven filaments, the fabric having spaced compaction elements and defining voids between the filaments. While the partially dewatered web is in the second nip, it is impressed against the fabric by the felt to force a predetermined portion of the web into the voids and provide bulk thereto. The web is then retained on the imprinting fabric after the web passes through the second nip and removed therefrom before final drying by applying the web to a creping surface at a third nip location, the third nip being formed between the creping surface and the imprinting fabric. The web is retained on the imprinting fabric in an essentially undisturbed condition during retention and transport thereof on the imprinting fabric between the second and third nips.
BRIEF SUMMARY OF THE INVENTION
The present invention also relates to a system for manufacturing a bulky, soft and absorbent paper web, and in common with the inventions covered by the two aforesaid applications, the present system utilizes an imprinting fabric to felt press in a stage of its operation. As compared to such prior art arrangements, however, the current system also incorporates two rotatable dryer means having smooth heated surfaces to which the web is applied and is removed therefrom in serial fashion after passing through the imprinting fabric-felt press. Specifically, the wet paper web is applied to the surface of the first rotatable dryer means, compacted substantially overall while on the surface, and removed therefrom. The partially dewatered web is then introduced into a wet embossing nip formed between a felt and an open mesh imprinting fabric formed of woven filaments having spaced compaction elements and defining voids between the filaments. While the web is in the wet embossing nip it is impressed against the fabric whereby from about 5% to about 50% of the web will be compacted by the compaction elements and from about 50% to 95% of the web will be impressed into the voids. The web is retained on the imprinting fabric after passing through the wet embossing nip and is transported by the fabric into contact with a heated surface of a second rotatable dryer means. The web is then dry creped from the second heated surface. Through utilization of this system, a high bulk, low density dry creped tissue is produced and drying costs minimized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view of a preferred form of apparatus constructed in accordance with the teachings of the present invention and for carrying out the method thereof; and
FIG. 2 is a view similar to that of FIG. 1 but illustrating an alternative form of apparatus.
DETAILED DESCRIPTION
Referring now to FIG. 1, a papermaking machine constructed in accordance with the teachings of the present invention is illustrated. The machine includes a paper web-forming device of any suitable type such as a Fourdrinier machine, the Fourdrinier wire 11 of which is illustrated. The Fourdrinier wire delivers the wet web W (normally in the order of from about 7% to about 23% solids) to a pick-up felt 14 forming an endless loop about a plurality of rollers including a suction pressure roll 16 and a blinded drilled pressure roll 18. Web pick-up by the felt may be facilitated through use of a steam box arrangement under the wire at the vacuum slot pick-up 20. Preferably a water shower 22 and uhle box combination are provided to clean and condition the felt prior to web pick-up.
Felt 14 forms a nip with a rotatable dryer can 26 which is heated by steam or other means and has a smooth solid outer surface. Transfer of the web W takes place at the location of suction pressure roll 16 so that roll 16 and the dryer can compact the web overall. While on the dryer can the web also passes through a nip defined by the pick-up felt and the dryer can in the vicinity of pressure roll 18. From that second nip continued rotation of the dryer can brings the web into contact with an imprinting fabric 30 looped about a roll 32 which may be plain or suction. Closely adjacent to roll 32 the web W is removed from dryer can 26 by a skinning doctor 34 and the web is applied to the imprinting fabric 30.
U.S. patent application Ser. No. 933,203 Hulit et al., filed Aug. 14, 1978, may be referred to for details of an imprinting fabric preferred for use in connection with the present invention. Specifically the imprinting fabric disclosed therein is an open mesh fabric formed of woven filaments. The fabric has compaction elements defined by the knuckles formed at the warp and weft crossover points of the fabric filaments and defines voids between the filaments. The imprinting fabric has a surface void volume of from about 15 cc/m 2 to about 250 cc/m 2 and preferably from about 40 cc/m 2 to about 150 cc/m 2 . The compaction element area of the imprinting fabric constitutes between about 5% and about 50%, and preferably from about 20% to about 35%, of the total web supporting surface area of the fabric.
Imprinting fabric 30 is in the form of a continuous loop rotating in a clockwise manner as viewed in FIG. 1. At the time the partially dewatered web is applied to the imprinting fabric 30 it has an overall fiber consistency of from about 40% to about 50%. The partially dewatered web then passes through a nip formed between the imprinting fabric and a papermaker's dewatering felt 36 also in the form of a continuous loop and moving in a counterclockwise manner as viewed in FIG. 1. A pressure roll 38 is in opposition to roll 32 to provide the desired nip pressure between the felt 36 and fabric 30. The imprinting fabric-felt press just described serves to increase the apparent bulk of web W by impressing from about 50% to 95% of the web into the voids of the imprinting fabric with the only significant compaction of the web taking place in the vicinity of the compaction elements. As noted in the aforesaid Hulit et al. application, an imprinting fabric of the type just described will retain the wet paper web impressed therein by the papermakers' dewatering felt after passing through the nip formed by these two elements.
The web W is now transferred to a through dryer 42 comprising a rotatable perforated dryer drum 44 and an outer hood 46 which receives the pressurized hot air or other heated fluid from the rotatable perforated drum in the conventional manner. The imprinting fabric 30 is looped about the perforated dryer drum 44 so that the web W passes about almost the entire circumference of the dryer drum sandwiched between the drum outer surface the imprinting fabric. After the web has passed through the through dryer it has an overall fiber consistency generally equal to or greater than 80% solids.
The web is then transported by imprinting fabric 30 to a Yankee dryer 50 and applied to the smooth heated outer creping surface thereof. Transfer to the Yankee takes place at the location of a solid Yankee pressure roll 52 with transfer to the creping surface preferably being facilitated by the application of a suitable adhesive, such as animal glue, to the Yankee surface or web by any suitable adhesive applicator 54 just prior to engagement of the web W with the Yankee creping surface. After being rotated about the Yankee drum the web is creped therefrom by a creping blade 56 and transferred to a suitable winding mechanism. As the imprinting fabric continues its travel from the Yankee back to the dryer can, it is cleaned as by means of a vacuum box 60 and air jet 62. The air jet may also be utilized to apply a spray of release agent such as emulsified mineral oil in water to the imprinting fabric.
FIG. 2 illustrates in schematic fashion an alternative form of papermaking machine layout incorporating the teachings of the present invention. The arrangement is in most respects identical to the arrangement of FIG. 1 and for this reason like components have been designated by the same reference numerals employed with respect to the FIG. 1 embodiment. The principal difference of this configuration as compared to that of FIG. 1 resides in the elimination of a through air dryer in the arrangement. Rather than proceed through a through dryer the imprinting fabric 30 transfers the web directly to the creping surface of the Yankee 50. It is obvious that the web W will be much wetter (in the order of 40-50% solids) when applied to the Yankee surface in FIG. 2 than is the case in the FIG. 1 embodiment. For this reason, the drying capacity of the Yankee 50 in FIG. 2 must be much greater, requiring either a larger Yankee or a reduction in web speed. Another difference resides in the fact there is an open draw between roll 32 and dryer can 26. This open draw arrangement could also be utilized in connection with the system of FIG. 1.
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A system for producing a bulky, soft and absorbent paper web wherein the web is creped from a first creping surface, passes through a nip formed between a dewatering felt and imprinting fabric of a specified character and is applied to and creped from a second creping surface.
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TECHNICAL FIELD
The present invention relates to a complex system which is capable of merging electric power generation and coal chemistry so as to utilize coal, the coal being highly utilized as heat, electricity, and a chemical raw material, for manufacture of char and raw material gas and electric power generation. This is achieved by reforming dried low rank coal, while being moved in a moving bed reformer, and pyrolyzing and gasifying the resulting dried low rank coal by the combustion heat and exhaust gas from a fluidized bed combustor (FBC) so as to obtain hydrocarbon gas and char. At the same time, electric power is generated by recycling heat with steam from the fluidized bed combustor where the char and the dried low rank coal are present. Furthermore, the reformed char may be used as a fuel for electric power generation and a heat source for steelmaking. On the other hand, the hydrocarbon gas is used as a chemical raw material.
BACKGROUND ART
The low rank coal, such as subbituminous coal or brown coal, which has a moisture content higher than about 20 mass % is limited to use within a coal-producing region. This is because, for example, the low rank coal has a low calorie resulting from its high moisture content and generates a small amount of heat by combustion. On the other hand, when dried, the low rank coal becomes more spontaneously combustible and more hygroscopic, resulting in transportation costs being relatively expensive, etc.
However, the low rank coal has advantages that are not found, e.g., in the bituminous coal that is considered to be a high rank coal. For example, brown coal found in Australia and Indonesia is low in sulfur content and produces less ash. Thus, using the brown coal as a fuel would make it possible to prevent air pollution due to sulfur dioxide gas, etc., as well as to reduce hazardous ash waste.
In this context, such techniques have been suggested which are adopted to carbonize the low rank coal by dehydration reform or thermal reform, thereby compensating for the drawbacks thereof. For example, disclosed in Patent Literature 1 and Patent Literature 2 is a technique by which oil and low rank coal are mixed into raw material slurry; the resulting slurry is heated and dehydrated in the oil, and then further heated to decompose or detach the carboxyl radical or the hydroxyl radical, etc., in the raw material coal by a decarboxylation reaction or a dehydration reaction, thereby reforming the raw material coal. Also disclosed is a technique by which heavy oil, etc., is penetrated into pores of the low rank coal so as to prevent spontaneous combustion.
On the other hand, disclosed in Patent Literature 3 is a coal gasification complex power generation facility which includes the following: a gasification unit for gasifying low rank coal having a relatively high moisture content; a gas power generation unit for generating electric power using a gas supplied from the gasification unit; a steam power generation unit for generating electric power by the heat of an exhaust gas emitted from the gas power generation unit; and a coal drying unit for drying coal by the exhaust heat emitted from the steam power generation unit and supplying the dried coal to the gasification unit. Disclosed in Patent Literature 4 is a method for manufacturing reformed coal and hydrocarbon oil by pyrolyzing brown coal into reformed coal and tar under an inert gas atmosphere or steam atmosphere and catalytically cracking the tar in a steam atmosphere and in the presence of an iron-based catalyst so as to obtain hydrocarbon oil.
CITATION LIST
Patent Literature
PTL 1: Japanese Published Unexamined Patent Application No. H07-233384
PTL 2: Japanese Patent No. 2776278
PTL 3: Japanese Published Unexamined Patent Application No. 2009-133268
PTL 4: Japanese Published Unexamined Patent Application No. 2010-144094
SUMMARY OF INVENTION
Technical Problem
However, the aforementioned conventional techniques had the following problems:
(1) For Patent Literatures 1 and 2, the use of oil requires various types of facilities for separating oil and coal in the same container, causing an increase in the size of the system and impairing energy-saving efficiency;
(2) The oil or an indirect material is required for the reforming of the coal, thereby causing a significant increase in costs and imposing a high environmental load;
(3) The method which employs the oil causes a heat exchange loss of the energy provided for the brown coal, thus leading to a significant energy loss;
(4) Furthermore, the oil used as an indirect material is mixed into the dried coal, thus causing a high loss of oil and impairing resource-saving efficiency;
(5) For Patent Literature 3, since the low rank coal is dried and then gasified in a gasification furnace so as to be combusted as a heat source in a boiler, it is possible to obtain a high calorie, but effective use would not be made of a useful chemical raw material contained in the low rank coal, thus impairing resource-saving efficiency;
(6) Patent Literature 3 is based on the high-temperature gasification of coal, so that the gas component after gasification is predominantly composed of low molecular-weight compounds and thus disadvantageous to subsequent chemical product synthesis;
(7) Patent Literature 3 has a significant restriction on the materials that form the facility because the gases are produced at high temperatures;
(8) For Patent Literature 4, the brown coal is pyrolyzed at 500° C. to 800° C. to obtain the reformed coal and the tar, and then the tar is catalytically cracked at 400° C. to 600° C. to thereby obtain the reformed coal and a compound. However, in general, when the low rank coal is heated above 500° C., cracks are increased and fine powder is produced, causing unburned coal to increase. Furthermore, since the pyrolysis gas may cause dangers of easily igniting combustible components or explosion of the powdered coal in a high oxygen concentration, there is a lack of safety and operability because it is difficult to control the operations of the system such as the control of oxygen concentration or addition of steam; and
(9) For Patent Literature 4, energy-saving efficiency is impaired because cooling is required when the brown coal is used as the reformed coal or when the powdered coal is combusted in a downstream stage.
The present invention was developed to solve the aforementioned conventional problems. It is therefore an object of the invention to provide a complex system for utilizing coal for manufacture of char and raw material gas and electric power generation, the complex system being adopted as follows:
(1) To utilize the combustion heat of fixed carbon of coal so as to heat the steam for electric power generation as well as to pyrolyze and gasify the low rank coal and manufacture char;
(2) To be capable of making the boiler more compact by employing oxygen fluidized-bed combustion;
(3) To be capable of reducing the separation energy of carbon dioxide gas, when the carbon dioxide gas is separated and recycled, by employing oxygen combustion because nitrogen gas is considerably reduced and thus carbon dioxide gas is high in concentration;
(4) To be capable of constructing a chemical complex which makes effective use of the exhaust heat from the boiler so as to use a pyrolysis gas and a gasified gas (volatile component) as a chemical raw material;
(5) To employ a moving bed reactor as the reformer, whereby the temperature of the product gas may be kept reduced and thus fewer restrictions are imposed on materials such as those for gas pipes, thereby providing outstanding maintainability;
(6) To be capable of reducing the temperature of product gas since a long pyrolysis reaction time is available, so that troubles due to a tar component (such as adhesion or caulking) may be solved and a large amount of relatively long-chain hydrocarbon components may be obtained, producing a gas that is advantageous for combustion and chemical synthesis;
(7) To charge the fixed carbon with the volatile component removed into an oxygen fluidized bed combustor without cooling the fixed carbon, thus achieving a high ignition quality and an outstanding energy-saving efficiency; and
(8) To be capable of combusting oxygen since high-temperature fixed carbon (char) with volatile components removed may be charged into the oxygen fluidized bed combustor from a portion of a low oxygen concentration in a counter flow relative to the combustion exhaust gas, whereby abnormal combustion or sudden combustion immediately after the charging may be suppressed even in the combustor of a high oxygen concentration.
Solution to Problem
To solve the aforementioned conventional problems, a complex system of the present invention for utilizing coal for manufacture of char and raw material gas and electric power generation is arranged as follows.
A complex system according to a first aspect of the present invention for utilizing coal for manufacture of char and raw material gas and electric power generation includes the following: a drying unit for drying low rank coal of a high moisture content; a reformer for reforming the low rank coal that has been dried in the drying unit; a fluidized bed combustor for employing, as a fuel, the reformed coal obtained in the reformer; a producer gas supply pipe for supplying a combustion exhaust gas from the fluidized bed combustor as a pyrolytic and gasifying agent to the reformer; and a catalyst reforming unit for reforming a volatile component and the combustion exhaust gas obtained from the low rank coal reformed in the reformer.
This arrangement may provide the following operations:
(1) Since the low rank coal is dried in the drying unit before being supplied to the reformer, even using the low rank coal as a fuel for the fluidized bed combustor may allow for preventing loss of heat energy that may be caused by vaporization of the contained moisture or removal of heat due to a leak of the steam, etc.;
(2) Heat energy may be used with improved efficiency because the exhaust gas emitted from the fluidized bed combustor is employed for drying the low rank coal. On the other hand, when compared with the case where an additional heat generating unit for generating heat is provided for dry the low rank coal, there is no need to supply an additional fuel or energy, thus achieving an outstanding energy-saving efficiency;
(3) Since the reformer is heated with the exhaust gas in the fluidized bed combustor and reforms the low rank coal, an outstanding energy-saving efficiency is achieved;
(4) The low rank coal has a high volatile component content; however, the volatile component is emitted by the reformer and allowed to react with CO, CO 2 , or H 2 O of the combustion gas in the gas reform unit in conjunction with a partially gasified gas, thereby allowing for utilizing the low rank coal as a useful chemical raw material;
(5) The char produced in a high temperature portion (inlet portion) in the reform unit may be utilized as raw material coal for steel making and a solid fuel that may be transported overseas, and as a fluidized bed fuel;
(6) Since the temperature of the producer gas (combustion exhaust gas) from the fluidized bed combustor is used for gas reform, an outstanding thermal efficiency and an outstanding energy-saving efficiency are achieved;
(7) Employing the moving bed reactor as the reformer achieves a product gas temperature of as low as 150° C. or less and prevents the condensation of the tar. Furthermore, the low temperatures will reduce restrictive conditions on the material such as for gas pipes, thus making it possible to reduce the costs for system construction and maintenance. Furthermore, low-speed heating may prevent the raw material coal from being powderized;
(8) Since employing the moving bed reactor as the reformer allows a low product gas temperature and an elongated pyrolysis reaction time, troubles resulting from the occurrence of tar components due to adhesion or caulking, etc., caused by the tar components will not occur, and a large amount of relatively long chain hydrocarbon components may be obtained. It is thus possible to produce gases that are advantageous for chemical raw materials;
(9) Since the fixed carbon with the volatile component removed in the reformer is charged into the oxygen fluidized bed combustor without cooling, a high ignition quality is achieved and no energy loss results;
(10) In the fluidized bed combustor, heat may be exchanged with efficiency between the exhaust gas of the fluidized bed combustor passing by against the body force of the particle bed and the particles;
(11) Since the high-temperature fixed carbon (char) with the volatile component removed is charged into the fluidized bed combustor from a portion of a low oxygen concentration, abnormal combustion or sudden combustion immediately after the charging may be suppressed, thus allowing oxygen combustion; and
(12) Since the exhaust gas has a lower oxygen concentration than air, the low rank coal that may be spontaneously oxidized and readily catch fire may be reformed at higher temperatures.
Here, (a) the low rank coal may not be limited to one of a specific name, such as subbituminous coal, lignite, or brown coal as long as the moisture content is above about 20 mass %. Furthermore, all coal to be used as a fuel need not be the low rank coal, but some high rank coal of a moisture content of below about 20 mass % may also be added.
(b) The drying unit is dried in the atmosphere of an inert gas such as a nitrogen gas at a low temperature (60° C. to 90° C.) and a low humidity (RH 70% to 0%). The inside of the drying unit is made up of a hot water (about 60° C. to 90° C.) pipe for warming the coal and a gas pipe for injecting a drying inert gas. Furthermore, the target moisture content of the low rank coal may be made 20 mass % or less. In the experiments, the moisture content was reduced to 16 mass %. This made the moisture content of the low rank coal one-third or less, thereby significantly improving transportation efficiency. Furthermore, using the char may prevent spontaneous combustion, thus achieving improved safety.
The nitrogen gas used is the one that is separated in an oxygen separator. The nitrogen gas may be heated in an air preheater which is heated with very hot water of the condenser. In this case, since the oxygen concentration is low, it is possible to prevent the low rank coal, which is spontaneously oxidized and readily increases in temperature as well as readily catches fire, from catching fire, and dry the coal at higher temperatures. Furthermore, since the nitrogen gas separated in the oxygen separator has a low relative humidity, the coal may be dried with increased efficiency. Furthermore, since waste heat is utilized without requiring additional heat energy, the system may be made environmentally friendly and outstanding in energy-saving efficiency.
(c) It is possible to recycle clean water from the high humidity exhaust gas discharged from the drying unit, thus making effective use of water. (d) The low rank coal is coarsely crushed, as preprocessing before being dried, into controlled grain sizes of 0.1 μm to 5 mm. Crushing into grain sizes of 0.1 μm to 5 mm may simplify the drying step so as to shorten the time for drying. The low rank coal is heated by heating the drying chamber of the drying unit using a cooling drain water (about 60° C. to 90° C.) pipe of the steam condenser of the steam turbine which generates electric power with the steam superheated in the fluidized bed combustor. Furthermore, as a heat transfer medium, air of a low oxygen content, CO 2 , or N 2 gas exchanges heat with the heated cooling drain water and is heated (to a temperature of 60° C. to 80° C. with RH of 0% to 70%) and is then directed into the drying unit to flow counter to the flow of the low rank coal so as to dry the coal. (e) As the reformer, a preferable one may employ the moving bed scheme by which the low rank coal is pyrolyzed and gasified while the low rank coal is flowing downwardly and the high-temperature exhaust gas from the fluidized bed combustor is flowing upwardly. The moving bed scheme allows the moving bed to have an elongated reaction time at the moving bed. Furthermore, the counterf low al lows for cooling the gas that has been reformed while being heat exchanged with the low rank coal. This makes it possible to obtain a chemical raw material that is made up of a pyrolysis gas and gasification gas as well as to obtain high-calorie reformed coal (char+ash). (f) In the fluidized bed combustor, employed as a fluidized bed material is limestone or dolomite, etc. As a fuel additive, preferably employed is a gas mixture of oxygen and carbon dioxide gas for adjusting (diluting) the concentration of oxygen. The fuel used is dried coal of the low rank coal that has been dried in the drying unit or reformed coal of the low rank coal that has been reformed in the reformer or char. (g) The combustion temperature of the fluidized bed combustor is controlled at 800° C. to 900° C. This allows for reducing use of special materials that withstand high temperatures as the furnace material and for preventing troubles such as melting of ash in the fluidized bed. (h) The catalyst reforming unit performs reforming by allowing the volatile component obtained from the low rank coal or a producer gas (combustion exhaust gas) such as CO 2 , CO, and H 2 O to be brought into contact with the catalyst, thereby yielding, such as, an FT synthesis gas, methanol synthesis gas, ammonia synthesis gas, hydrogen gas, or synthesis natural gas.
Furthermore, a produced tar component may be reformed to continually obtain low molecular-weight hydrocarbon, carbon monoxide, and hydrogen.
The complex system according to a second aspect of the present invention for utilizing coal for manufacture of char and raw material gas and electric power generation is made up of as follows in the first aspect of the invention: a pyrolysis unit for allowing an ascending flow of a combustion exhaust gas of the fluidized bed combustor to decompose the low rank coal supplied from the drying unit at a pyrolysis temperature of 300° C. to 600° C. while the reformer is moving the low rank coal; and a gasification unit for partially decomposing the low rank coal char produced in the pyrolysis unit from fixed carbon into CO and H 2 at 600° C. to 800° C.
This arrangement provides the following operations in addition to those of the first aspect:
(1) The dried brown coal may be pyrolyzed into the volatile component+char with the exhaust gas supplied from the fluidized bed combustor, and the char may be further gasified;
(2) Unconverted char and ash are supplied to the fluidized bed combustor so as to combust the char, whereby a high calorie may be obtained, thus providing an outstanding thermal efficiency;
(3) Since the char contains no moisture, it is possible to achieve a high combustion efficiency and considerably reduce heat loss;
(4) Typically, char is difficult to ignite on its own. However, the char is mixed with the dried brown coal so as to produce an ignition volatile component, or preheated to about 800° C. to be combusted in a high oxygen concentration, thereby achieving smooth ignition and combustion;
(5) The decomposing in the two stages of the pyrolysis unit and the gasification unit enables char for steelmaking, char as a transportable fuel, and hydrocarbon gas as a chemical raw material to be separated and recycled with high accuracy;
(6) Employing the moving bed scheme allows for elongating the reaction time, thereby reducing troubles such as adhesion due to tar;
(7) It is possible to choose the component of a gas to be extracted by producing a temperature distribution in the reformer or by selecting a point at which the gas is extracted;
(8) The moving bed scheme makes it possible to lower the temperature of the product gas, so that the downstream facility for cooling coal gases, etc., may be eliminated or simplified, thereby making the facility compact;
(9) The gasification in the carbon dioxide gas atmosphere ensures high safety;
(10) Since no nitrogen gas is contained in the produced gas, the coal gas may be separated with ease;
(11) Unlike the fluidized bed in which the temperature in the bed is uniformed, so that the gasification temperature and the temperature of the pyrolysis gas have to be equal to the temperature in the bed, the moving bed makes it possible to bring the combustion exhaust gas at about 800° C. into contact with char at the starting part of the moving bed so as to advance the gasification. In addition, heat absorption and a drop in gas temperature allow for pyrolysis at 300° C. to 600° C. in the middle part of the moving bed while preventing overheating; and
(12) The moving bed may be regulated to temperatures of 100° C. to 300° C. at the uppermost portion depending on the particle bed height. Lowering the temperature of the uppermost portion allows the heavy oil having a relatively high boiling point to be condensed at the upper portion of the particle bed and prevented from being distillated. In addition, the heavy oil may be again pyrolyzed and converted into gas, light oil, and char. To obtain the heavy oil, the temperature of the uppermost portion has to be increased to suppress the condensation of the heavy oil.
Here, the travel speed of the moving bed may be adjusted according to the feed rate of the char to the fluidized bed combustor. Unlike the case of the fluidized bed where particles are completely mixed resulting in the size of char particles having a significant distribution, the char discharged from the moving bed has a uniform size and thus the fluidized bed combustion may be stabilized with ease. The reformer has a two-stage or an integrated structure, in which the combustion exhaust gas of the fluidized bed combustor is supplied at 500° C. to 800° C. from the lower portion.
The complex system according to a third aspect of the present invention for utilizing coal for manufacture of char and raw material gas and electric power generation is adopted in the first or second aspect of the invention such that carbon dioxide gas supplied as a diluent for fuel additive oxygen to the fluidized bed combustor is a carbon dioxide gas discharged and separated from the catalyst reforming unit.
This provides the following operation in addition to those of the first or second aspect:
(1) The carbon dioxide gas discharged from the fluidized bed combustor and the reformer is recycled, thus providing an improved effect of reducing environmental loads.
Advantageous Effects of Invention
As described above, the complex system of the present invention for utilizing coal for manufacture of char and raw material gas and electric power generation provides the following advantageous effects.
The first aspect of the invention provides the following advantageous effects:
(1) Since the low rank coal is dried in the drying unit before being supplied to the reformer, it is possible to suppress the vaporization of the moisture contained in the low rank coal of a high moisture content and the loss of heat energy due to removal of heat by the leakage of steam, etc.;
(2) Since the low rank coal is dried using the exhaust heat emitted from the fluidized bed combustor or the waste heat produced in the power generation cycle, it is possible to utilize heat energy with improved efficiency. On the other hand, when compared with the case where there is provided an additional heat generating unit for generating heat so as to dry the low rank coal, no additional fuel or energy needs to be charged and thus an outstanding energy-saving efficiency is achieved;
(3) The reformer is heated by the exhaust gas from the fluidized bed combustor for reform and gasification, thus achieving an outstanding thermal efficiency;
(4) The low rank coal has a high volatile component content; however, the volatile component and the gasified gas react with CO, CO 2 , or H 2 O of the combustion gas in the gas reform unit, thereby allowing for converting and utilizing the coal as a useful chemical raw material;
(5) Since the temperature of the exhaust gas from the fluidized bed combustor is used for gas reform, an outstanding thermal efficiency and an outstanding energy-saving efficiency are achieved;
(6) The temperature of the product gas to be produced is reduced by employing the moving bed reactor as a pyrolysis and gasification unit, thereby reducing restrictive conditions on the materials such as for gas pipes;
(7) At the same time, the pyrolysis reaction time may be elongated by employing the moving bed. Thus, this prevents troubles due to tar components (such as adhesion or caulking) and makes it possible to obtain a large amount of relatively long-chain hydrocarbon components, allowing for producing a gas advantageous for chemical product synthesis;
(8) Since the fixed carbon with the volatile component removed is charged into the oxygen fluidized bed combustor without cooling, a high ignition quality is achieved and no energy loss results; and
(9) Since the high-temperature fixed carbon (char) with the volatile component removed is supplied to the oxygen fluidized bed combustor in a counterflow direction relative to the exhaust gas and thus may be charged into the oxygen fluidized bed combustor from a portion of a low oxygen concentration, abnormal combustion or sudden combustion immediately after the charging may be suppressed, thus allowing oxygen combustion.
The second aspect of the invention provides the following advantageous effects in addition to those of the first aspect:
(1) The dried brown coal is pyrolyzed into volatile components and char with the combustion gas supplied from the fluidized bed combustor, and the char is further gasified;
(2) Unconverted char and ash are supplied to the fluidized bed combustor so as to combust the char, whereby a high calorie may be obtained, thus providing a high thermal efficiency;
(3) Since the char contains no moisture, a high combustion efficiency and no heat loss are achieved;
(4) Typically, char is difficult to ignite on its own. However, the char is preheated to about 800° C. to be combusted in a high oxygen concentration, thereby achieving smooth ignition and combustion;
(5) Employing the moving bed scheme allows for elongating the reaction time, thereby reducing troubles such as adhesion due to tar;
(6) It is possible, by producing a temperature distribution, to choose the component of a gas at a point at which the gas is extracted; and
(7) The moving bed scheme for the pyrolysis and gasification unit makes it possible to lower the temperature of the product gas, so that the downstream facility for cooling coal gases, etc., may be eliminated, thereby providing an outstanding energy-saving efficiency and making the facility compact.
The third aspect of the invention provides the following advantageous effects in addition to those of the first or second aspect:
(1) The carbon dioxide gas discharged from the fluidized bed combustor and the reformer is recycled, thus providing an improved effect of reducing environmental loads;
(2) Use of an inert gas for drying, thereby reducing the danger of explosion, etc.; and
(3) Since CO 2 has a high specific heat, heat may be transferred with ease (i.e., the cooling efficiency is high).
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic view illustrating a complex system according to an embodiment for utilizing coal for manufacture of char and raw material gas and electric power generation.
FIG. 2 is a view of heat balance according to an embodiment.
FIG. 3 is a view of material balance according to an embodiment.
DESCRIPTION OF EMBODIMENTS
Hereinafter, description will be made to the mode for carrying out the present invention with reference to the drawings.
FIG. 1 is a schematic view illustrating a complex system according to an embodiment for utilizing coal for manufacture of char and raw material gas and electric power generation.
FIG. 1 shows a complex system 1 for utilizing coal for manufacture of char and raw material gas and electric power generation. The complex system 1 includes a drying unit 2 for drying low rank coal such as brown coal, which is in the shape of lump coal having a grain size of 1 μm to 5 mm and a moisture content of generally 60 mass %, using the gas flow of an inert gas such as air having a low oxygen content or nitrogen of which temperature and relative humidity are controlled at 60° C. to 80° C. and 0% to 70%, respectively. The drying is continued until the moisture content becomes 20 mass %. In this implementation example, the drying chamber of the drying unit 2 includes a pipe for 60° C. to 90° C. hot water connected to a condenser (to be discussed later) for warming the coal, and a gas pipe for injecting an N 2 gas into the drying chamber, the N 2 gas being separated in an oxygen separator (to be discussed later) and heated in an air preheater (to be discussed later). The moisture in the exhaust gas in the drying unit 2 is recycled by makeup water treatment and supplied to the condenser. The complex system 1 also includes a dust collector 2 a for removing dust particles, etc., from the exhaust gas of the drying unit 2 . Further included is a reformer 3 that is adopted to reform the low rank coal, which has been dried in the drying unit 2 and transferred in a transfer material, in two-stage reactions of pyrolysis and partial gasification, and vaporize and detach volatile components and tar components, etc., so as to reform the low rank coal into char, ash, and coal gas. The reformer 3 is capable of performing the reform in the two-stage reactions of the pyrolysis and partial gasification, thereby adapting the physical properties of the product char to the requirements for service. Also included are the following: a fluidized bed combustor 4 to which the char and ash reformed in the reformer 3 (hereafter referred to as the reformed coal) is supplied so as to produce main steam for a steam turbine; a cyclone 5 for removing ash from the exhaust gas of the fluidized bed combustor 4 ; an oxygen preheater 6 for exchanging heat between the exhaust gas separated in the cyclone 5 and the oxygen separated in an oxygen separator (to be discussed later) so as to preheat the oxygen gas; and an oxygen separator 7 for separating the oxygen gas and the nitrogen gas from the atmosphere. The oxygen gas obtained from the oxygen separator 7 is preheated in the oxygen preheater 6 and used as a fuel additive for the fluidized bed combustor 4 . Furthermore, the nitrogen gas obtained at the same time is heated and used to dry the low rank coal. Further included are the following: a cyclone 8 for separating ash, etc., from a gasified gas that includes volatile components or tar components gasified with a gasifying agent composed of the exhaust gas from the fluidized bed combustor when the low rank coal is reformed in the reformer 3 ; a catalyst reforming unit 9 which brings the gasified gas with the ash separated in the cyclone 8 into contact with a catalyst such as zeolite, Fe, Co, Ni, or Cu so as to refine a chemical raw material such as an FT synthesis gas, methanol synthesis gas, ammonia synthesis gas, hydrogen gas, or synthesis natural gas; a carbon dioxide gas pipe 10 for supplying, as a CCS, the combustion exhaust gas or the carbon dioxide gas produced (as a by-product) in the catalyst reforming unit 9 as a diluent for the concentration of the oxygen gas in a carbon dioxide gas reservoir unit and the fluidized bed combustor 4 ; a steam turbine 11 for rotating a power generator with the main steam of the fluidized bed combustor 4 ; a condenser 12 ; a power generator 13 ; and a drying gas preheater 14 for allowing the very hot water of the condenser 12 to heat the nitrogen gas separated in the oxygen separator 7 . The nitrogen gas preheated in the drying gas preheater 14 is fed into the drying unit 2 so as to dehydrate and dry the low rank coal. Also included are the following: a water feed pump 15 for pressurizing feedwater to supply condensate from the condenser 12 into a combustor heat transfer water pipe; a feedwater heater 16 for allowing the steam (extracted vapor) from the turbine to preheat the condensate from the water feed pump 15 ; and a cooling tower 17 .
The complex system, arranged as described above, for utilizing coal for manufacture of char and raw material gas and electric power generation will be described as follows in terms of each unit operation.
(1) The low rank coal is coarsely crushed in advance, e.g., in a ball mill and separated and transferred in an air current, and then supplied to the drying unit 2 of the complex system for utilizing coal for manufacture of char and raw material gas and electric power generation.
(2) In the drying unit 2 , a drying gas of a relative humidity of 0% to 70% at a temperature of 65° C. to 110° C. is employed so that the moisture content of the low rank coal with the grain size controlled to 0.1 μm to 5 mm is lowered to 20 mass or less. The drying gas to be employed is the waste heat that is recycled from the steam turbine, the combustor fluidized bed material, and the reformed coal product.
(3) The reformer 3 preferably employs the moving bed scheme by taking slagging measures into account, in the case of which the combustion exhaust gas with the high-temperature portion controlled serves as a pyrolytic and partial gasifying reform agent. This allows for elongating the reaction time and preventing troubles such as caulking of tar components. Furthermore, the cracking of a component having a long carbon chain may be accelerated and as well allowed to serve to cool a product coal gas, thereby facilitating the handling of the produced coal gas.
The reformer may take advantage of a two-stage rotary kiln.
This allows for selecting between direct heating/reform and indirect heating by the combustion gas. The reformed coal may be set by the combustion gas to 600° C. to 500° C. and an inlet dried coal charge temperature of 300° C. to 400° C.
(4) The fluidized bed combustor 4 employs a fuel additive that is obtained by allowing the oxygen separated in the oxygen separator 7 , which separates oxygen from atmosphere, to be diluted with the carbon dioxide gas produced (as a by-product) or separated from the catalyst reforming unit 9 .
(5) The catalyst reforming unit 9 employs a solid reform catalyst such as iron or an alkaline component. More specifically, it is possible to utilize a fixed bed, etc., which employs a perovskite carrying alkaline earth catalyst. This makes it possible to decompose a heavy component such as a tar component into a light component.
The low rank coal to be employed may be subbituminous coal, low moisture content brown coal (lignite), or high moisture content brown coal (brown coal). The moisture content and heat value thereof are shown in (Table 1).
TABLE 1
Power
Moisture
generation
content
Heat value
efficiency:
Coal type
(mass %)
(kcal/kg)
HHV (%)
Bituminous coal
5
6500
34.5
Low
Subbituminous coal
20
5500
33.5
rank
Low moisture
40
4000
31.2
coal
content brown coal
(Lignite)
High moisture
65
2000
28.0
content brown coal
(Brown coal)
The low rank coal moisture is divided into surface adhesion moisture and internal moisture (equilibrium moisture), where the surface adhesion moisture may be dried and removed at 100° C. or less.
The moisture of coal may be reduced to about one-half of the equilibrium moisture by being dried at 80° C. to 150° C. (also referred to as typical drying). However, heating and drying at 150° C. or less reduce the tendency to reform the low rank coal. In this context, the drying unit 2 employed an N 2 gas at a temperature of 60° C. to 80° C. with a relative humidity of 0% to 70%.
Next, heating at about 180° C. to 300° C. would cause a hydrophilic oxygen containing group such as the phenol group or the carboxyl group to have a tendency to be pyrolyzed. The internal moisture in the coal is removed by heating, and the hydrophilic oxygen containing group such as the phenol group and the carboxyl group is decomposed to produce H 2 O and CO 2 and turned to be hydrophobic, resulting in degradation in the hygroscopicity of the coal. Furthermore, the oxygen content in the coal is reduced and thereby inactivated, thus suppressing spontaneous combustion to some extent.
Furthermore, heating to 300° C. or higher causes the equilibrium moisture to start to reduce and considerably reduce at 350° C. or higher to one-half or less of the equilibrium moisture by the typical drying. At this time, the tar component in the coal is liquefied to effuse to the surface through the pores of the coal. From the scanning electron micrograph of the surface and by the measurement of the specific surface area, this may also be seen from the fact that the coal specific surface area is considerably reduced. For example, when raw material coal of a specific surface area of 1.7 m 2 /g is heated at 430° C. and then rapidly cooled, the specific surface area is reduced to about 0.1 m 2 /g.
The tar component which is spread inside the pores and over part of the coal surface and solidified is considered to cause the coal to be reduced in specific surface area and inactivated so as to be degraded in hygroscopicity as well as in spontaneous combustion property. Furthermore, heating over 450° C. to about 500° C. would cause the equilibrium moisture to be further reduced; however, from the scanning electron micrograph and the measurement of the specific surface area, a number of cracks are found on the surface of the coal and the specific surface area sharply increases to about 2.4 m 2 /g.
Furthermore, when heating over 500° C., the coal tends to have more cracks and become brittle, causing generation of fine powder to increase. In this context, the reformer 3 employing the moving bed makes it possible to prevent the coal from being powderized due to the low-speed heating with the moving bed.
On the other hand, the high moisture content brown coal of a moisture content of 65 mass % has an amount of moisture of about 1×65/(100−65) that is approximately equal to 1.86 kg per 1 kg of dried coal. Thus, since the brown coal of a high moisture content has a moisture loss of 1.86 kg from a chimney and the moisture loss is 650 kcal per 1 kg of water, the moisture loss is 650×1.86=1209 kcal per 1 kg of dried coal. Therefore, the heat quantity that may be converted to steam is 5720−1209=4511 kcal per 1 kg of dried coal. The effectively employable heat quantity ratio of the high moisture content brown coal to the bituminous coal (the heat quantity that may be converted into steam is 5720 kcal) is 4511/5720 that is approximately equal to 79%.
According to Table 1, the high moisture content brown coal provides a power generation efficiency of 28%, and when compared with 34.5% of the bituminous coal (moisture content: 5 mass %), it holds that 28.0/34.5 approximately equal to 81%, which is generally equal to the aforementioned heat quantity ratio. That is, the heat quantity ratio between the two types of coal is equal to the difference between the moisture losses. In this context, to increase the heat quantity of the low rank coal by dehydration reform in order to generate electric power with the low rank coal employed as a fuel, the heat quantity had to be increased by the moisture loss or more, that is, the steam consumption required for treating 1 kg of water was a consumption of 1 kg steam or more according to the conventional dehydration reform method.
In this context, the inventors have intensively made a close study of the complex system for utilizing coal, which is high in calorie and power generation efficiency, for manufacture of char and raw material gas and electric power generation and completed as an invention, the complex system being adopted to vaporize the moisture of the low rank coal with a small amount of heat energy as well as to detach the high volatile component with the energy of the combustion gas so as to utilize the same not as a fuel but as a raw material for chemical products.
Furthermore, an operation method of the system includes the following steps: a grain size control step of controllably crushing low rank coal into grain sizes of about 0.1 μm to 5 mm; a drying step of drying the low rank coal having controlled grain sizes to a moisture content of 20 mass % or less; a reforming step of using an exhaust gas from a fluidized bed combustor to reform the dried coal dried in the drying step; a catalyst reform step of reforming the gasified gas reformed in the reform step to a chemical raw material; a combustion step of combusting, in the fluidized bed combustor, the reformed coal (char and ash) reformed in the reform step so as to produce steam; and a power generation step of generating electric power by the steam. Furthermore, the operation method is achieved by the reform step including a pyrolysis step for pyrolyzing the dried coal and a gasification step of gasifying the pyrolyzed and dried coal. The char that may be excessively produced may be employed as a steelmaking raw carbon material and a transportable solid fuel.
Next, a computer simulation was performed on the heat balance and the material balance of the complex system according to this embodiment for utilizing coal for manufacture of char and raw material gas and electric power generation. As a condition, unworked brown coal of Victorian origin was employed as low rank coal. The initial moisture of the brown coal was 60 mass %, the moisture of dried brown coal when dried in the drying unit 2 was 20 mass %, the fuel ratio was 1.2, and electric power was generated with an efficiency of 30%.
The results are shown in FIGS. 2 and 3 .
FIG. 2 is a view showing a heat balance according to the embodiment, and FIG. 3 is a view showing a material balance according to the embodiment.
From FIGS. 2 and 3 , when the moisture of the fuel brown coal is reduced, the heat energy that may be utilized for electric power generation is increased, that is, the amount of power generation is increased. It is also seen that the exhaust heat that is produced in the power generation process is used for the drying energy, thereby providing increased efficiency. Furthermore, reducing the moisture of the brown coal may cause an increase in the produced retort gas enthalpy, thus achieving a further improved efficiency in the retorting operation. Furthermore, employing CO 2 circulation facilitates the recycle of CO 2 even when CO 2 storage is targeted.
INDUSTRIAL APPLICABILITY
According to the present invention, dried low rank coal is pyrolyzed and gasified, while being moved in a reformer such as the moving bed, by the combustion heat of reformed brown coal in the fluidized bed combustor (FBC) so as to recycle hydrocarbon gas and char, etc., and the reformed char is supplied to the oxygen fluidized bed combustor so as to produce steam for electric power generation, thereby generating electric power and producing CO 2 gas at a controlled supply temperature for pyrolysis and gasification. This allows for providing a complex system which is capable of utilizing coal for manufacture of char and raw material gas and electric power generation by merging electric power generation and coal chemistry so as to make full use of heat, electricity, and chemical products.
REFERENCE SIGNS LIST
1 : complex system for utilizing coal in manufacture of char and raw material gas and electric power generation
2 : drying unit
3 : reformer
4 : fluidized bed combustor
5 : cyclone
6 : oxygen preheater
7 : oxygen separator
8 : cyclone
9 : catalyst reforming unit
10 : carbon dioxide gas pipe
11 : steam turbine
12 : condenser
13 : power generator
14 : drying gas preheater
15 : water feed pump
16 : feedwater heater
17 : cooling tower
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Most of the abundant naturally occurring low rank coal, which has a high moisture content and a high oxygen content, is transported with poor efficiency; utilized for heating with degraded thermal efficiency because of the loss of heat due to sensible heat for heating moisture and latent heat for vaporizing moisture; and utilized in existing coal combustion facilities with difficulty due to a high volatile component content. A complex system of the present invention for utilizing coal for manufacture of char and raw material gas and electric power generation is adopted to include: a drying unit for drying low rank coal of a high moisture content; a reformer for reforming the low rank coal that has been dried in the drying unit; a fluidized bed combustor for employing, as a fuel, the reformed coal obtained in the reformer; a producer gas supply pipe for supplying a combustion exhaust gas from the fluidized bed combustor as a pyrolytic and gasifying agent to the reformer; and a catalyst reforming unit for reforming a volatile component and the producer gas obtained from the low rank coal reformed in the reformer.
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BACKGROUND OF THE INVENTION
The invention generally pertains to gripping mechanisms for rock or earth boring or cutting machines, and more specifically relates to inflatable gripping devices for rock or earth boring or cutting machines.
U.S. Pat. No. 2,946,578 issued to DeSmaele disclosed an excavator apparatus having a fitting circumferentially disposed therearound wherein the fitting comprises a deformable peripheral casing. The casing can be deformed by injection of an appropriate fluid under pressure. The deformed casing comes into tight engagement with the walls of the bore hole to allow a second portion of the machine to move with respect to the first portion of the machine that is gripped within the bore hole by the deformable peripheral casing. As best shown in FIG. 4 of DeSmaele, the deformable peripheral casing is comprised of rim 26, whose diameter exceeds slightly the diameter of body 2 of the excavating machine. The rim 26 covers at its front end a sleeve 138 fastened to the head plate 10. The ceiling between a collar 214 fastened to the rim 26 on the sleeve 138 is effected by a rubber seal 211, clamped to the flange 214 of the rim 26 by reinforced collar 215 bolted to the flange 214. The rim 26 is provided at its middle part with a peripheral reinforced rubber fitting 28 which is applied and held on the rim 26 by a ring 216 comprised of three arcuated parts, assembled by two rings 216a and 216b. The fitting contains three chambers or cushions 200, 201 and 202 arranged circumferentially. These cushions are connected by nipples 217, 218 and 219 to air tubes 203, 204 and 205. It is important to note, as stated above, that ring 216, to which cushion 201 is attached, is comprised of arcuate members that contour the external surface of the excavating machine. Thus, the arcuate segments of ring 216 are specifically designed for an excavating machine having a very precise diameter, and the arcuate members of ring 216 cannot be employed on an excavating machine having a different diameter.
Referring to FIG. 9A of DeSmaele, it is important to note that the length of elastomeric tail fitting 28 and of cushion 201 is substantially greater than the length of ring 216, which forms the base onto which elastomeric tail fitting 28 and cushion 201 are attached. Thus, as cushion 201 is inflated to extend elastomeric tail fitting 28 to brace the excavating machine in the bore hole, elastomeric tail fitting 28 and cushion 201 are subject to extreme movement relative to the tunnel and the excavating machine in a direction parallel with the longitudinal axis of the excavating machine. This relative movement of elastomeric tail fitting 28 and of cushion 201 causes extensive wear at the point of contact between both cushion 201 and elastomeric tail fitting 28 with ring 216, such that cushion 201 and elastomeric tail fitting 28 are prone to tear or separate from ring 216.
In addition to the above patent, which pertains to stabilizing an excavating machine for drilling substantially horizontal bore holes, prior art patents exist for stabilizing a drill string or the like in a substantially vertical bore hole. Exemplary patents include U.S. Pat No. 3,088,532 issued to Kellner; U.S. Pat No. 3,105,561 issued to Kellner; U.S. Pat No. 3,126,971 issued to Kellner; U.S. Pat No. 3,180,436 issued to Kellner et al.; U.S. Pat. No. 3,298,449 issued to Bachman et al.; U.S. Pat. No. 3,376,942 issued to Van Winkle; U.S. Pat No. 4,463,814 issued to Horstmeyer et al.; and U.S. Pat No. 5,186,264 issued to du Chaffaut. As in DeSmaele, all of the above patents disclose elastomeric inflatable portions and substantially arcuate base segments such that the arcuate base segments cannot be applied to a machine having a different diameter. Furthermore, the devices of all of the above patents disclose stabilizing, guiding or bracing members that do not completely circumferentially encase a portion of the exterior surface of the boring or cutting apparatus.
A need thus exists for an inflatable gripper assembly for a rock boring or cutting machine having a base member and elastomeric sheet secured in a fluid-tight manner to the base member that is configurable in a first deflated configuration and a second inflated configuration.
A need thus exists for the above type of inflatable gripper assembly in which the base member is planar, such that the inflatable gripper assembly can be installed on a plurality of rock boring or cutting machines, each having a different diameter.
A need further exists for the above type of inflatable gripper assembly wherein the length of the elastomeric sheet, when inflated, is no greater than the length of the base member, and the width of the elastomeric sheet, when inflated, is no greater than the width of the base member, such that movement of the elastomeric sheet relative to the tunnel and parallel with the longitudinal axis of the rock boring or cutting machine is minimized.
A need additionally exists for the above inflatable gripper assembly wherein when the cutting diameter of a rock boring or cutting machine is increased by increasing the diameter of the cutter head of the rock boring or cutting machine, the number of inflatable gripper assemblies attached to the outer surface of the rock boring or cutting machine can be increased, and a lengthening shim having a predetermined depth can be located between each inflatable gripper assembly on the exterior surface of the rock boring or cutting machine.
SUMMARY OF THE INVENTION
An inflatable gripper assembly for a rock boring or cutting machine is disclosed. The inflatable gripper assembly comprises a base member and an elastomeric sheet secured in a fluid-tight and reaction force secure manner to the base member. The elastomeric sheet expands when fluid is supplied between the base member and the elastomeric sheet to brace a rock boring or cutting machine in a shaft or tunnel. The elastomeric sheet contracts when fluid is removed from between the base member and the elastomeric sheet to allow the rock boring or cutting machine to move within the shaft or tunnel.
Most preferably, the base member is planar such that the inflatable gripper assembly can be installed on a plurality of rock boring or cutting machines, each having a different diameter or cutting size.
Preferably, the length of the elastomeric sheet when inflated is no greater than the length of the base member, and the width of the elastomeric sheet when inflated is no greater than the width of the base member, such that movement of the inflatable gripper assembly relative to the excavation and parallel with the longitudinal axis of the rock boring or cutting machine is minimized.
The base member preferably has a circumferential ridge located thereon and the elastomeric sheet has an outer edge that is secured over the ridge of the base member in a fluid-tight manner. This configuration further minimizes movement of the inflatable gripper assembly with respect to the excavation in a direction parallel with the longitudinal axis of the rock boring or cutting machine.
When the cutting diameter of a rock boring or cutting machine is to be increased by, for example, increasing the diameter of the cutter head of the rock boring or cutting machine, the number of gripper assemblies attached to the outer surface of the rock boring or cutting machine is increased and a shim having a predetermined depth is located between each gripper assembly and the exterior surface of the rock boring or cutting machine in order to increase the effective diameter of the rock boring or cutting machine such that gripping can occur by the gripper assemblies in the shaft or tunnel, which will have a larger diameter due to the increased diameter of the cutter head.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the present invention will be more fully appreciated when considered in light of the following specification and drawings in which:
FIG. 1 is a side elevational view, partially exposed, of the inflatable gripper assembly of the present invention attached to a first exemplary rock boring machine;
FIG. 2 is a partially exposed top view of the inflatable gripper assembly of the present invention attached to the first exemplary rock boring machine;
FIG. 3 is a partially exposed top view of the inflatable gripper assembly of the present invention attached to a first exemplary rock boring machine with the addition of extension shims therebetween;
FIG. 4 is an enlarged top view of the inflatable gripper assembly of the present invention;
FIG. 5 is a cross-sectional view of the inflatable gripper assembly of the present invention in an uninflated configuration of FIG. 4 taken along lines 5--5;
FIG. 6 is a cross-sectional view of the inflatable gripper assembly of the present invention in an inflated configuration of FIG. 4 taken again along lines 5--5;
FIG. 7 is a schematic view of an exemplary fluid system for actuating the inflatable gripper assembly of the present invention;
FIG. 8 is a side elevational view, partially exposed, of the inflatable gripper assembly of the present invention attached to a second exemplary rock boring machine; and
FIG. 9 is a cross-sectional view of the inflatable gripper assembly of the present invention attached to a second exemplary rock boring machine of FIG. 8 taken along lines 9--9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, down reamer 2 is shown as an exemplary rock or earth boring or cutting machine for use with inflatable gripper assembly 4 of the present invention. It is to be understood that down reamer 2 is merely exemplary and is not intended to limit the scope of the subject invention, as inflatable gripper assembly 4 can be employed to intermittently grip almost any configuration of rock or earth boring or cutting machine in a bored hole or cut excavation. For example, inflatable gripper assembly 4 can also be employed on tunnel boring machines which bore a substantially horizontal tunnel through the earth or rock, as disclosed in U.S. Pat No. 2,946,578 issued to DeSmaele. Inflatable gripper assembly 4 is comprised of mounting frame 6 which, as shown best in FIG. 2, is comprised of a plurality of arcuate segments 8 that are interconnected such that mounting frame 6 is substantially circular. A plurality of flanges 10 disposed along the interior of arcuate segments 8 of mounting frame 6 connect a plurality of thrust cylinders 12 to mounting frame 6. Thrust cylinders 12 also connect mounting frame 6 to planetary gear box 14 having planetary gears 16 therein. Main bearing 18 is circumferentially disposed around the periphery of planetary gearbox 14. Stabilizing feet 20 are attached to the periphery of planetary gearbox 14 and provide stabilization of planetary gearbox 14 and inflatable gripper assembly 4 in relation to the shaft or tunnel being bored. With the exception of inflatable gripper assembly 4 and cylinders 12, all of the components described in regard to down reamer 2 are found in U.S. Pat No. 5,325,932 issued to Anderson et al. for DOWN REAMING APPARATUS, which is incorporated herein by reference.
Drill string 22 passes through mounting frame 6 of inflatable gripper assembly 4 and into planetary gearbox 14. Drill string 22 is rotated by a motor means known in the art to facilitate the cutting or boring action of down reamer 2, as will be described in further detail below. Cutter head 24 is connected to the underside of planetary gearbox 14 by torque tube 25 and spider support arms 26. Cutter head 24 has a plurality of cutters 28 located thereon for cutting rock or packed earth. Lower stabilizer 30 is attached under cutter head 24 and precedes cutter head 24 into the previously bored pilot hole in order to provide additional stability for down reamer 2.
As drill string 22 is rotated, stabilizing feet 20, lower stabilizer 30, and inflatable gripper assembly 4, being braced against the wall of the bored hole, do not rotate with the drill string 22. Cutter head 24, torque tube 25 and spider support arms 26 all rotate with the drill string 22 to effectuate cutting or boring. To initiate cutting or boring, thrust cylinders 12 are first configured in their retracted position and, as drill string 22 rotates cutter head 24, thrust cylinders 12 are energized to their extended position. At this time, inflatable gripper assembly 4 has been inflated, as will be described below in greater detail, to brace down reamer 2 against the wall of the shaft or tunnel being bored. At the end of the stroke of thrust cylinders 12, the rotation of cutter head 24 is stopped and inflatable gripper assembly 4 is deflated while thrust cylinders 12 are retracted, thus pulling inflatable gripper assembly 4 along the length of the shaft or tunnel that is equivalent to the bore stroke of down reamer 2. Inflatable gripper assembly 4 is then re-inflated and cutter head 24 is again rotated to begin another cutting sequence as thrust cylinders 12 are again energized.
Referring now to FIG. 3, if the cutting diameter of cutter head 24 is, for example, increased such that the diameter of the bore hole being cut will increase, it is necessary to increase the effective diameter of inflatable gripper assembly 4 to enable the individual gripping units 32 on mounting frame 6, which comprise inflatable gripper assembly 4, to maintain contact with the bore hole when inflatable gripper assembly 4 is in the inflated configuration. Thus, extension shim 34 is fixedly secured by bolts or the like between mounting frame 6 and each individual gripping unit 32 such that the overall diameter of inflatable gripper assembly 4 will increase by an amount equivalent to twice the depth of extension shim 34.
FIG. 4 shows an individual gripper unit 32 attached to mounting frame 6 by clamp ring 36. Clamp ring 36 is fixedly secured to mounting frame 6 by bolts 38 or other fastening means well known in the art. Clamp ring 36 need not be continuous but can consist of individual pieces to facilitate assembly.
Referring to FIG. 5, which shows individual gripper unit 32 in its deflated configuration, and in FIG. 6 which shows individual gripper unit 32 in its inflated configuration contacting a bored hole, gripper unit 32 is comprised of elastomeric sheet 40 and base 42. Elastomeric sheet 40 is comprised of any material having suitable elastic and fluid retentive qualities to allow fluid to be retained under pressure between elastomeric sheet 40 and base 42 such that the fluid pressure causes elastomeric sheet 40 to expand to facilitate gripping of down reamer 2 against a bore hole wall. For example, elastomeric sheet 40 can be comprised of rubber or a non-porous synthetic polymer having elastomeric qualities. Elastomeric sheet 40 preferably has an interior inflatable length (defined as the interior length that can receive and contain fluid) that is no greater than the length of base 42. Elastomeric sheet 40 has an interior inflatable width (defined as the interior width that can receive and contain fluid) that is no greater than the width of base 42. The above interior inflatable length and interior inflatable width limitations on elastomeric sheet 40 ensure that the movement of elastomeric sheet 40 relative to the wall of the bore hole and parallel with the longitudinal axis of down reamer 2 is minimized to limit tearing of elastomeric sheet 40 and separation of elastomeric sheet 40 from base 42. Elastomeric sheet 40 preferably has a central portion 44 and an outer periphery 46. The thickness of central portion 44 is preferably less than the thickness of outer periphery 46 to reduce the volume and hence the cost of elastomeric sheet 40 in the construction of the gripper assembly 4. The outermost extent of outer periphery 46 forms ridge 48 which is firmly, but removably, secured between clamping ring 36 and base 42 to ensure a fluid-tight attachment of elastomeric sheet 40 to base 42 and to positively react the axial and tangential forces resulting from the thrust and torque of the boring machine. In the event that fluid leakage persists around ridge 48, an inflatable bladder (not shown) can be employed in a similar manner.
Base 42 is preferably substantially planar, lacking any substantial curvature such that base 42 and elastomeric sheet 40 can be removed as a unit from down reamer 2 and transferred to a different rock boring or cutting machine having a circumference different than that of the circumference of down reamer 2. To facilitate the aforesaid transfer of elastomeric sheet 40 and base 42 to another rock boring or cutting machine, base 42 is removable from mounting frame 6. Fluid valve 50 in base 42 allows fluid to pass through fluid line 52 and into fluid chamber 54 that is formed between base 42 and elastomeric sheet 40 to inflate and deflate gripper unit 32.
As shown in FIG. 7, the fluid system employed to inflate and deflate gripping units 32 of inflatable gripper assembly 4 is comprised of a fluid source 56 which communicates with check valve 58. Check valve 58 ensures that when fluid source 56, which is preferably a compressor operating at approximately 8-14 bar, is deactivated fluid does not pass back into fluid source 56. Directional control valve 60 is located between check valve 58 and gripping units 32 and enables the fluid, which is for example compressed air, to either be fed to gripping units 32 to inflate them when directional control valve 60 is configured in a first position, or allows the fluid to escape to atmosphere from gripping units 32 to deflate them when directional control valve is configured in a second position. Needle valve 62 is employed to manually by-pass the check valve 58 if required.
Referring to FIGS. 8 and 9, miniature tunnel boring machine 64, a second exemplary rock boring machine is shown which, unlike down reamer 2, bores shafts vertically, or at angles from vertical, up through rock. Miniature tunnel boring machine 64 is comprised of cutter head 66 having stabilizing shoes 68 thereon. Inflatable gripper assembly 4, which can be comprised of the same gripping units 32 employed on down reamer 2 despite the difference in circumference between down reamer 2 and miniature tunnel boring machine 64 due to the planar aspect of base 42, is located between cutter head 66 and emergency gripper 70. Emergency gripper 70 engages in the event that power is lost. Launching tube 72 is located rearwardly of emergency gripper 70 and is configured to propel cutter head 66 and inflatable gripper assembly 4 up into a rock face to cut the desired bore hole. Launching tube 72 is supported by crawler 74 which has cab 76 thereon. Rock conveyor 78 extends past cab 76 and communicates with launching tube 72 for the transport of cut rock from cutter head central opening 80 and through launching tube 72.
As shown in FIG. 9, gripping units 32 are attached to mounting frame 82 which is comprised of a plurality of faces 84 such that mounting frame 82 is substantially octagonal in shape whereby each of faces 84 supports one of gripping units 32 thereon. It is to be understood that gripping units 32 are comprised of the same elements as described in relation to down reamer 2 and, as stated above, gripping units 32 can be the identical gripping units that have been transferred from down reamer 2; the only difference being that fewer gripping units 32 are employed on miniature tunnel boring machine 64 than on down reamer 2 because miniature tunnel boring machine 64 has a smaller diameter than that of down reamer 2. Thrust cylinders 86 are connected between gripper assembly 4 and cutter head 66 to provide relative movement, or thrusting, between cutter head 66 and mounting frame 82 during boring, as described above in relation to down reamer 2. Also as described in relation to down reamer 2, gripping units 32 are inflated and deflated to allow gripping and advancing of cutter head 66, respectively. The only major difference to be noted regarding the functioning of down reamer 2 and miniature tunnel boring machine 64 is that, during the initial advancing of cutter head 66, launching tube 72 provides the advancing reaction forces while in down reamer 2, the initial advancing reaction forces are provided by a pre-developed shaft. As shown in FIG. 9, motors 88 are employed to facilitate rotation of cutter head 66 during cutting.
While particular embodiments of the present invention have been described in some detail herein above, changes and modifications may be made in the illustrated embodiments without departing from the spirit of the invention.
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An inflatable gripper assembly for a rock boring or cutting machine is disclosed. The inflatable gripper assembly comprises a base member and an elastomeric sheet secured in a fluid-tight and reaction force secure manner to the base member. The elastomeric sheet expands when fluid is supplied between the base member and the elastomeric sheet to brace a rock boring or cutting machine in a tunnel. The elastomeric sheet contracts when fluid is removed from between the base member and the elastomeric sheet to allow the rock boring or cutting machine to move within the tunnel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation in part of U.S. patent application Ser. No. 11/854,044 now issued as U.S. Pat. No. 8,172,983 filed on Sep. 12, 2007.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
This invention relates to a method of increasing the strength of a paper mat of fibers produced in a papermaking process. Paper mat comprises water and solids and is commonly 4 to 8% water. The solid portion of the paper mat includes fibers (typically cellulose based fibers) and can also include filler. Increasing the strength of the paper mat would allow one to increase the proportion of the solids that is filler content. This is desirable because it reduces raw materials costs, reduces energy needed in the papermaking process, and increases the optical properties of the paper. Prior Art discloses paper mat having a solid portion of between 10% and 40% filler. The Prior Art however also discloses that increasing the filler content coincides with a loss in strength in the resulting paper.
Fillers are mineral particles that are added to paper mat during the papermaking process to enhance the resulting paper's opacity and light reflecting properties. Some examples of fillers are described in U.S. Pat. No. 7,211,608. Fillers include inorganic and organic particles or pigments used to increase the opacity or brightness, or reduce the cost of the paper or paperboard sheet. Some examples of fillers include one or more of: kaolin clay, talc, titanium dioxide, alumina trihydrate, barium sulfate, magnesium hydroxide, pigments such as calcium carbonate, and the like. Previous attempts to increase the filler content in paper without losing paper strength are described in British Patent GB 2016498, and U.S. Pat. Nos. 4,710,270, 4,181,567, 2,037,525, 7,211,608, and 6,190,663.
Calcium carbonate filler comes in two forms, GCC (ground calcium carbonate) and PCC (precipitated calcium carbonate). GCC is naturally occurring calcium carbonate rock and PCC is synthetically produced calcium carbonate. Because it has a greater specific surface area, PCC has greater light scattering abilities and provides better optical properties to the resulting paper. For the same reason however, PCC filled paper mat produces paper which is weaker than GCC filled paper.
Paper strength is a function of the number and the strength of the bonds formed between interweaved fibers of the paper mat. Filler particles with greater surface area are more likely to become engaged to those fibers and interfere with the number and strength of those bonds. Because of its greater surface area, PCC filler interferes with those bonds more than GCC.
As a result, papermakers are forced to make an undesirable tradeoff. They must either choose to select a paper with superior strength but inferior optical properties or they must select a paper with superior optical properties but inferior strength. Thus there is a clear need for a method of papermaking that facilitates a greater amount of filler in the paper, a paper that has a high opacity, and a filled paper that has a high degree of strength.
BRIEF SUMMARY OF THE INVENTION
At least one embodiment of the invention is directed towards a method of papermaking having an increased filler content. The method comprises the steps of: adding a first flocculating agent to an aqueous dispersion in an amount sufficient to mix uniformly in the dispersion without causing significant flocculation of the filler particles,
adding a second flocculating agent to the dispersion after adding the first flocculating agent in an amount sufficient to initiate flocculation of the filler particles in the presence of the first flocculating agent, the second flocculating agent being of opposite charge to the first flocculant, combining the filler particles with the paper fiber stock, treating the combination with at least one strength additive, and forming a paper mat from the combination. The paper fiber stock comprises a plurality of fibers and water, and the initiated flocculation enhances the performance of the strength additive in the paper mat.
At least one embodiment of the invention is directed towards this method in which the strength of the paper made by the papermaking process is increased by an amount greater than the sum of: the strength enhancement provided by the preflocculation process using the first and second flocculating agents and the strength enhancement provided by the strength additive by itself.
The filler may be selected from the group consisting of calcium carbonate, kaolin clay, talc, titanium dioxide, alumina trihydrate, barium sulfate, and magnesium hydroxide. The paper fiber may be cellulose fiber. The method may further comprise the step of shearing the dispersion to obtain a predetermined floc size. The filler flocs may have a median particle size of 10-100 μm. The first and second flocculating agents may have an RSV of at least 2 dL/g. The first flocculating agent may be anionic. The strength additive may be glyoxylated Acrylamide/DADMAC copolymer. The ratio of strength additive relative to the solid portion of the paper mat may be 0.3 to 5 kg of strength additive per ton of paper mat. The first flocculating agent may be a copolymer of acrylamide and sodium acrylate. The strength additive may be a cationic starch. The strength additive and the second flocculating agent may carry the same charge.
The second flocculating agent may be selected from the list consisting of copolymers of acrylamide with DMAEM, DMAEA, DEAEA, DEAEM. The second flocculating agent may be in quaternary ammonium salt form made with a salt selected from the list consisting of dimethyl sulfate, methyl chloride, benzyl chloride, and any combination thereof. The filler may be anionically dispersed and a low molecular weight, cationic coagulant is added to the dispersion to at least partially neutralize its anionic charge prior to the addition of the first flocculating agent. The second flocculating agent may have a charge, which is opposite to the charge of the first flocculating agent. The filler flocs may have a median particle size of 10-100 μm. The filler may be selected from the group consisting of calcium carbonate, kaolin clay, talc, titanium dioxide, alumina trihydrate, barium sulfate and magnesium hydroxide. The low molecular weight composition may be a cationic coagulant, the first flocculating agent may be an anionic flocculent, the second flocculating agent may be a cationic flocculent, and both flocculants may have a molecular weight of at least 1,000,000
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:
FIG. 1 is a graph showing the improved strength of paper made according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
For purposes of this application the definition of these terms is as follows:
“Coagulant” means a composition of matter having a higher charge density and lower molecular weight than a flocculant, which when added to a liquid containing finely divided suspended particles, destabilizes and aggregates the solids through the mechanism of ionic charge neutralization.
“DMAEM” means dimethylaminoethylmethacrylate as described and defined in U.S. Pat. No. 5,338,816.
“DMAEA” means dimethylaminoethylacrylate as described and defined in U.S. Pat. No. 5,338,816.
“DEAEA” means diethylaminoethyl acrylate as described and defined in U.S. Pat. No. 6,733,674.
“DEAEM” means diethylaminoethyl methacrylate as described and defined in U.S. Pat. No. 6,733,674.
“Flocculant” means a composition of matter having a low charge density and a high molecular weight (in excess of 1,000,000) which when added to a liquid containing finely divided suspended particles, destabilizes and aggregates the solids through the mechanism of interparticle bridging.
“Flocculating Agent” means composition of matter that when added to a liquid, destabilizes and aggregates colloidal and finely divided suspended particles in liquid into flocs.
“GCC” means ground calcium carbonate, which is manufactured by grinding naturally occurring calcium carbonate rock
“PCC” means precipitated calcium carbonate which is synthetically produced.
“Preflocculation” means the modification of filler particles into agglomerates through treatment with a particular flocculating agent selected on the basis of the size distribution and stability of the floc that the flocculating agent will form.
In the event that the above definitions or a definition stated elsewhere in this application is inconsistent with a meaning (explicit or implicit) which is commonly used, in a dictionary, or stated in a source incorporated by reference into this application, the application and the claim terms in particular are understood to be construed according to the definition in this application, and not according to the common definition, dictionary definition, or the definition that was incorporated by reference.
At least one embodiment of the invention is a method of making paper, which is strong, has a high filler content, and has superior optical properties. In at least one embodiment of the invention the method of papermaking comprises the steps of: providing filler material, pre-treating at least some of the filler material by preflocculation leading to a decrease in the adsorption of a strength additive on the filler material, and adding both the preflocculated filler blend and the strength additive to the paper mat.
Preflocculation is a process in which, material is treated by two flocculating agents in a manner that optimizes the size distribution and stability of the flocs under a particular shear force prior to its addition to the paper stock. The particular chemical environment and high fluid shear rates present in modern high-speed papermaking require filler flocs to be stable and shear resistant. The floc size distribution provided by a preflocculation treatment should minimize the reduction of sheet strength with increased filler content, minimize the loss of optical efficiency from the filler particles, and minimize negative impacts on sheet uniformity and printability. Furthermore, the entire system must be economically feasible. Examples of preflocculation methods applicable to this invention are described in US Published Application 2009/0065162 A1 and U.S. application Ser. No. 12/431,356.
It has been known for some time that adding strength additives to paper mat increases the strength of the resulting paper. Some examples of strength additives are described in U.S. Pat. No. 4,605,702. Some examples of strength additives are cationic starches, which adhere to the cellulose fibers and tightly bind them together.
Unfortunately it is not practical to add large amounts of strength additives to compensate for the weakness that results from using large amounts of filler in paper mat. One reason is because strength additives are expensive and using large amounts of additives would result in production costs that are commercially non-viable. In addition, adding too much strength additive negatively affects the process of papermaking and inhibits the operability of various forms of papermaking equipment. As an example, in the context of cationic starch strength additives, the cationic starch retards the drainage and dewatering process, which drastically slows down the papermaking process.
Adding filler to the paper mat reduces the effectiveness of the strength additive. Because filler has a much higher specific surface area than fiber, most of the strength additives added into the papermaking slurry go to filler surfaces, and therefore there is less strength additive available to bind the cellulose fibers together. This effect is more acute with PCC compared to GCC because PCC has a much higher surface area and is able to adsorb more strength additive. One method of addressing this situation is by pre-treating the filler material with a coagulant as described in U.S. application Ser. No. 12/323,976. Another method involves using preflocculation instead of a coagulant.
In at least one embodiment the filler content in the paper is increased by the following method: An aqueous dispersion of filler materials is formed and the filler materials are preflocculated before being added to a paper fiber stock. A first flocculating agent is added to the dispersion in an amount sufficient to mix uniformly in the dispersion without causing significant flocculation of the filler particles. A second flocculating agent is then added following the first flocculating agent, in an amount sufficient to initiate flocculation of the filler material in the presence of the first flocculating agent, the second flocculating agent being of opposite charge to the first flocculating agent. A paper mat is formed by combining the preflocculated filler material with the fiber stock and treating this combination with the strength additive. The preflocculation of the filler material enhances the performance of the strength additive. The fiber stock comprises fibers, fillers, and water.
In at least one embodiment, the fibers are predominantly cellulose based. In at least one embodiment the flocculated dispersion is sheared to obtain a particularly desired particle size.
While pre-treating filler particles is known in the art, prior art methods of pre-treating filler particles are not directed towards affecting the adhesion of the strength additive to the filler particles with two flocculants. In fact, many prior art pre-treatments increase the adhesion of the strength additive to the filler particles. For example, U.S. Pat. No. 7,211,608 describes a method of pre-treating filler particles with hydrophobic polymers. This pre-treatment however does nothing to the adhesion between the strength additive and the filler particles and merely repels water to counterbalance an excess of water absorbed by the strength additive. In contrast, the invention decreases the interactions between the strength additive and the filler particles and results in an unexpectedly huge increase in paper strength. This can best be appreciated by reference to FIG. 1 .
FIG. 1 illustrates that a paper produced from a paper mat that includes PCC filler tends to become weaker as more PCC filler is added. When a large amount of PCC is added (over 25%), the addition of a strength additive adds little strength to the paper. Paper made from preflocculated PCC filler combined with a strength additive however increases the strength of the paper to a degree that it is stronger than paper having 10% less PCC that is not preflocculated. Even more surprising was the fact that paper containing preflocculated PCC without a strength additive was almost as strong as the paper with the strength additive.
As a result, at least two conclusions can be reached, 1) the strength agent is more effective in increasing sheet strength with preflocculated filler than with untreated filler and 2) there is a synergistic effect from the combination of strength agent and filler preflocculation which makes it superior to the additive effects of the sum of the strength agent alone plus the filler preflocculation alone. As a result, preflocculation of the PCC filler material leads to the production of paper that is unexpectedly strong.
At least some of the fillers encompassed by this invention are well known and commercially available. They include any inorganic or organic particle or pigment used to increase the opacity or brightness, reduce the porosity, or reduce the cost of the paper or paperboard sheet. The most common fillers are calcium carbonate and clay. However, talc, titanium dioxide, alumina trihydrate, barium sulfate, and magnesium hydroxide are also suitable fillers. Calcium carbonate includes ground calcium carbonate (GCC) in a dry or dispersed slurry form, chalk, precipitated calcium carbonate (PCC) of any morphology, and precipitated calcium carbonate in a dispersed slurry form. The dispersed slurry forms of GCC or PCC are typically produced using polyacrylic acid polymer dispersants or sodium polyphosphate dispersants. Each of these dispersants imparts a significant anionic charge to the calcium carbonate particles. Kaolin clay slurries also are dispersed using polyacrylic acid polymers or sodium polyphosphate.
In at least one embodiment, the strength additive carries the same charge as the second flocculating agent. Strength additives encompassed by the invention include any one of the compositions of matter described in U.S. Pat. No. 4,605,702 and US Patent Application 2005/0161181 A1 and in particular the various glyoxylated Acrylamide/DADMAC copolymer compositions described therein. An example of a glyoxylated Acrylamide/DADMAC copolymer composition is product# Nalco 64170 (made by Nalco Company, Naperville, Ill.).
In at least one embodiment, the fillers used are PCC, GCC, and/or kaolin clay. In at least one embodiment, the fillers used are FCC, GCC, and/or kaolin clay with polyacrylic acid polymer dispersants or their blends. The ratio of strength additive relative to solid paper mat can be 3 kg of additive per ton of paper mat.
In at least one embodiment, the effectiveness of the synthetic strength additive is independent of or despite the presence of some, low amounts, or no amount of starch in the paper mat. In prior art disclosures, it is known that adding between 10 to 20 lbs of starch per ton of paper mat increases the strength of the resulting paper. The addition of materials in such large amounts however is cumbersome and less than ideal. The use of synthetic strength additives in contrast allows similar strength performance to be achieved while requiring the addition of far less strength additive material to the paper mat. In at least one embodiment the synthetic strength additive is cationic or anionic or contains both cationic and anionic functional groups.
Unfortunately synthetic strength additives are known to be far more expensive than starch. In some processes the cost of using bulky large amounts of starch may be less expensive than smaller and more easily manageable amounts of synthetic strength additives. The combination of the strength adding effects of synthetic strength additives in low dosages combined with the preflocculation allows unexpected degrees of strength to be observed than would otherwise be expected with such low dosages of strength additives and in the absence of large amounts or any amount of starch.
EXAMPLES
The foregoing may be better understood by reference to the following example, which is presented for purposes of illustration and is not intended to limit the scope of the invention.
A furnish was produced containing 25% pine softwood and 75% eucalyptus hardwood. Both the softwood and hardwood were reslushed from dry lap. The filler used was Albacar HO PCC obtained from Specialty Minerals Inc. The filler material preflocculation was performed with the dual flocculant approach described in example 14 of U.S. application Ser. No. 12/431,356. During the handsheet preparation, 6 lb/ton strength additive (Nalco 64114, a glyoxalated Acrylamide/DADMAC copolymer available from Nalco Company, Naperville, Ill., USA) was added. The results are displayed in FIG. 1 .
While this invention may be embodied in many different forms, there are shown in the drawings and described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. All patents, patent applications, scientific papers, and any other referenced materials mentioned herein are incorporated by reference in their entirety. Furthermore, the invention encompasses any possible combination of some or all of the various embodiments described herein and incorporated herein.
The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
All ranges and parameters disclosed herein are understood to encompass any and all subranges subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, (e.g. 1 to 6.1), and ending with a maximum value of 10 or less, (e.g. 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
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The invention provides a method of producing paper with a higher proportion of mineral filler particles than is otherwise be possible without the expected loss in paper strength by preflocculating the filler particles. The method allows for the use of the greater amount of filler particles by coating at least some of the filler particles with a material that prevents the filler materials form adhering to a strength additive. The strength additive holds the paper fibers together tightly and is not wasted on the filler particles.
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RELATED APPLICATION
[0001] This application is a continuation of, and claims priority from, pending prior application Ser. No. 12/316,050 filed Dec. 8, 2008, which claims priority to prior application Ser. No. 09/529,792, which issued on Sep. 29, 2009 as U.S. Pat. No. 7,596,609, both of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to world wide web page retrieval and, in particular, to methods and apparatus for performing such retrieval using a minimally restrictive syntax.
BACKGROUND OF THE INVENTION
[0003] The World Wide Web (WWW) is a set of protocols that allow a user to download and upload pages of information between his computer and other computers, typically using a program called a browser. The usual mode of operation includes opening a browser, entering a URL (Uniform Resource Locator), and viewing the page fetched by the browser. The actual pages of information are located on physical host machines, each of which may be mapped to one or more domain names. Typically each domain is served by one host machine.
[0004] URL syntax is described in RFC 1630 (“Uniform Resource Identifiers in WWW”). The URL syntax relies heavily on the domain name space, as defined in RFCs 1034 (“Domain Names—Concepts and Facilities”), 1035 (“Domain Names Implementation and Specification”) and 883 (Domain names—Implementation and Specification”).
[0005] A network resource (host) is identified in the domain name space by a string containing 1 or more labels (each up to a maximum of 63 characters), separated by periods. The periods are intended to define and outline the hierarchical structure of domain name space. Although RFC 1034 permits the use of 8-bit binary encoding, it is suggested that applications use 7 bit ASCII for naming. Further, the suggested and currently implemented (de facto) naming scheme uses labels consisting only of alphanumeric characters from the Latin (ISO Latin 1) Character set plus the hyphen character. A valid name must start with a letter and the rest of the name should contain only letters, digits or hyphens.
[0006] Thus, the naming conventions for domains (and consequently sites and URLs) are rather restricted. Typically, there is an attempt to identify a particular site with a particular site owner, so that the address is meaningful. For example, IBM has a web site with the address “http://www.ibm.com” (“.com” indicates commercial), Microsoft has the address “http://www.microsoft.com” but Microsoft Network has the address of “http://www.msn.com”. The restrictions make it easy to create a one-to-one mapping between web addresses and a particular site. However, these addresses must be entered accurately. Any mistake will result in the site not being located.
[0007] In many countries, English is not a native tongue. Meaningful WWW addresses in such countries are typically created by transliterating the name of the site owner into Latin letters. Unfortunately, many languages do not have an accepted and widely known standard of transliteration. Thus, there may be several plausible transliterations for a single name, resulting in several possible meaningful addresses, only one of which is correct.
[0008] Another problem is that the current address name scheme is not user friendly. First, in countries in which most people are not English speaking, the use of Latin letters and/or English spelling conventions may be a burden to many users, especially non-experienced users. In addition, in many cases there is no direct relationship between the name of the site owner and the address of his site. Guessing the address is typically not an option. Further, in countries where the name is transliterated, even if a meaningful address is created (such as for IBM, above) there is still no guarantee that a casual user will correctly transliterate that name from his native language. In many cases, the site addresses can be used as mnemonics, i.e., once the address is known, its content makes it easy to remember. However, it is often impossible to reconstruct the correct address from the name of the site owner.
[0009] For these and other reasons, search engines and WWW directories have been developed, in which a user enters a name and/or other information regarding the site owner and a WWW page containing a list of possible site addresses is generated and presented to the user. Some search engines allow the entry of non-Latin characters. In addition, various automated agents and SearchBots have been developed which serve as online search agents and which interface directly with the browser, for example, the WebTurbo software. In some browsers, an incorrectly entered name will automatically pull up a search page.
[0010] Some Web browsers allow a user to maintain a local list of preferred locations, which are stored and accessed by selection of a nickname and/or a description from a list, rather than by entering a complete URL. In some browsers, an incompletely typed URL may be automatically expanded by the addition of a standard suffix or postfix. Another helpful feature is automatic completion of URLs. If a URL has been previously used, entering the first few characters thereof will cause the entire URL to be suggested to a user.
[0011] The underlying addressing system in the Internet is based on numeric strings. However, in order to provide some measure of comfort, textual addresses, as described above, are used. A DNS (Domain Name Server) is a distributed application that translates textual addresses into numeric addresses. If the address is incorrectly formatted or incorrectly entered, it does not generate a proper numeric address. Rather it returns an output which generates an error message at the requester. The different DNS servers update each other with new mappings of textual addresses to numeric addresses.
[0012] Many network systems supply aliasing support and/or “hosts” files that contain associations between numeric strings and textual strings. In some systems, for example Microsoft Windows 95 with Hebrew Support, it is possible to enter and use (on the network, not on an external DNS) a host name including non-Latin characters. It should be noted that host names are also limited, for example, they cannot contain spaces.
[0013] M. Duerst, in WWW document “http://www.w3.org/international/draft-duerst-dns-i18n-00.txt” (a working draft), suggests introducing a new zero-level domain to allow the use of arbitrary characters from the Universal Character Set (ISO 10646), also known as Unicode, in domain names. Duerst suggests an implementation in which software with an internationalized user interface, such as a web browser will be responsible for conversions. The software would analyze the domain name, call the (DNS) resolver directly if the domain name conforms to the domain name syntax restrictions and otherwise encode the name according to the specifications described in the document. Duerst also suggests providing a separate look up service that programs will call if a domain name contains characters outside the allowed range. Francois Yergeau, in WWW document “http://www.alis.com:8085/ ˜ yergeau/url-00.html”, suggests an 8-bit encoding for the Unicode, called UTF-8 (UCS Transformation Format 8), which preserves the full US-ASCII range, so that it is compatible with file systems, parsers and other software which relay on US-ASCII values but are transparent to other (8-bit) values.
SUMMARY OF THE INVENTION
[0014] It is an object of some embodiments of the present invention, to allow a user to retrieve a WWW page using a native language, other than English and optionally using non-Latin characters, such as Cyrillic, Hebrew and Arabic.
[0015] It is an object of some preferred embodiments of the invention to allow flexible naming of Domains and URLs, preferably using non-Latin characters. Preferably, the length is not substantially limited in length.
[0016] It is an object of some preferred embodiments of the invention to allow a user to enter partial information regarding a site owner, preferably without imposing an order on the information. Preferably, such information directly retrieves a home page, which belongs to a site matching the entered information.
[0017] It is an object of some preferred embodiments of the invention, to allow a user to directly access WWW pages, without requiring the user to recall long and/or obtuse URLs and/or without requiring the user to make selections and/or perform any additional procedure beyond what would have been required if the user had in fact typed the URL.
[0018] It is an object of some preferred embodiments of the invention to allow a user to surf the WWW using his native language, preferably, without requiring changes in existing hardware/software products.
[0019] In accordance with a preferred embodiment of the invention, a user enters a native language alias and/or name for a site owner and that input is converted into a numeric string address, so that data stored at the site can be retrieved. Preferably, the user enters the input into a standard portion of a browser, a location entry window, just as a standard URL would be entered. In accordance with one preferred embodiment of the invention, the input is converted by a DNS server. Preferably the DNS server directly translates the input to a numeric string. Alternatively, the DNS translates the input to a corresponding standard URL, which is then translated into a numeric string.
[0020] Alternatively, the input is translated into a standard URL by a local program which then transfers the URL to the browser. Alternatively, the browser passes the input to a program that performs the translation and transmits the generated URL to the Internet. Alternatively, a proxy server translates the input either to a numeric string or to a corresponding standard URL. Alternatively, a name server masquerades as a DNS server and converts non-standard names into standard names and/or IP addresses. Standard names are preferably passed to a standard DNS server.
[0021] In accordance with a preferred embodiment of the invention, there is provided a database which associates URLs and/or domain names with native language information and/or nicknames indicative of the site owners. Thus, a user can enter information which is associated with the site owner, rather than a proper name or a transliteration thereof. In some preferred embodiments of the invention, a translator, when determining a mapping between a native language input and a standard URL, consults the database. Preferably, the translation is performed as a service and/or as a proxy service. Preferably, the database is maintained at a single location, external to the machine that requires the translation. Alternatively, there is more than one site at which the database or a portion thereof, is maintained. Alternatively, the database resides on the same machine as the translator. Thus, in some cases, distributed databases need to be kept up to date.
[0022] In a preferred embodiment of the invention, periodic updates are sent to all the machines and are automatically assimilated in a local copy of a database. Preferably, the update comprises only changes. Alternatively, the entire database is transferred as a replacement file. In accordance with a preferred embodiment of the invention, the local database operates as a cache, so that fewer “external” queries are required. Preferably, when attempting to match partial information with site related information, previously and/or recently used URLs are selected over unused URLs with a similar matching. It should be noted in this context, that as a result of the explosive growth of the Internet in the last few years, the event of a new domain name/URL address being added is more common than the event of an address being changed or deleted.
[0023] There is therefore provided in accordance with a preferred embodiment of the invention, a method of WWW page retrieval from a web site, comprising:
[0024] entering information associated with the site, which information is not a WWW address or a portion thereof; and
[0025] directly displaying said page, using a browser, without any additional user intervention, beyond said entering,
[0026] wherein said information is in a non-Latin language.
[0027] There is also provided in accordance with a preferred embodiment of the invention, a method of WWW page retrieval from a web site, comprising:
[0028] entering information associated with the site, which information is not a WWW address or a portion thereof; and
[0029] directly displaying said page, using a browser, without any additional user intervention, beyond said entering,
[0030] wherein directly displaying comprises analyzing said information using user-dependent information.
[0031] There is also provided in accordance with a preferred embodiment of the invention, a method of WWW page retrieval from a web site, comprising:
[0032] entering information associated with the site, which information is not a WWW address or a portion thereof; and
[0033] directly displaying said page, using a browser, without any additional user intervention, beyond said entering,
[0034] wherein said information is entered into a URL entry field in said browser.
[0035] There is also provided in accordance with a preferred embodiment of the invention, a method of WWW page retrieval from a web site, comprising:
[0036] entering information associated with the site, which information is not a WWW address or a portion thereof; and
[0037] directly displaying said page, using a browser, without any additional user intervention, beyond said entering,
[0038] wherein said page is selected responsive to a geographical location at which said information is entered.
[0039] In a preferred embodiment of the invention, said information is in a non-Latin language.
[0040] In a preferred embodiment of the invention, said information does not meet domain name specifications. Alternatively or additionally, said information does not meet URL specifications. Alternatively or additionally, said information comprises a plurality of words. Alternatively or additionally, said information comprises a field identifier and a field-match value. Alternatively or additionally, said information is associated with an owner of the site. Alternatively or additionally, said information comprises a partial street address of said owner. Alternatively or additionally, said information comprises a telephone number of said owner.
[0041] In a preferred embodiment of the invention, the method comprises analyzing said partial information to determine a single translation thereof. Preferably, analyzing comprises correcting spelling in said information. Preferably, correcting spelling comprises correcting for at least one transliteration error.
[0042] In a preferred embodiment of the invention, analyzing comprises applying natural language recognition on said information. Alternatively or additionally, analyzing comprises blocking access to certain types of sites. Alternatively or additionally, said translation comprises a only domain name. Preferably, said translation comprises a URL. Alternatively or additionally, said association is determined using a database of associations.
[0043] Preferably, said database is at least logically associated with a particular user. Preferably, said database includes information regarding a particular user, which information is entered by said user, which page is selected for display responsive to said information and wherein said database is stored at a location remote from where the information is entered for display of said page.
[0044] Alternatively or additionally, said database comprises at least one association which is particular to said particular user. Preferably, analyzing comprises analyzing responsive to said at least one association. Alternatively or additionally, said at least one association is entered by said particular user. Alternatively or additionally, said at least one association is automatically generated responsive to a selection of a WWW page, from a plurality of suggested pages, by said particular user.
[0045] In a preferred embodiment of the invention, at least one association in said database is automatically generated responsive to a selection of a particular WWW page, from a plurality of suggested pages, by a plurality of users.
[0046] In a preferred embodiment of the invention, said database is at least logically associated with a translation server, which utilizes said database for translation.
[0047] In a preferred embodiment of the invention, said at least logical association comprises a physical association.
[0048] In a preferred embodiment of the invention, said analyzing is performed locally, where said page is displayed. Alternatively or additionally, said analyzing is performed remotely from where said page is displayed. Alternatively or additionally, said analyzing comprises determining a one-to-one mapping between said information and a translation. Alternatively or additionally, said analyzing utilizes a geographical location at which said information is entered.
[0049] In a preferred embodiment of the invention, said information is entered by a user in a same way in which a standard URL would be entered. Alternatively or additionally, said information is entered into a window overlaying said browser. Preferably, said window is overlaying a location window of said browser.
[0050] In a preferred embodiment of the invention, said information is entered in a language not supported by said browser. Alternatively or additionally, said information is entered in a font not supported by said browser. Alternatively or additionally, directly displaying said page, comprises automatically providing password information for accessing said page. Preferably, a plurality of such passwords are stored in a password database associated with said user.
[0051] There is also provided in accordance with a preferred embodiment of the invention, a server comprising:
[0052] a database associating business information with WWW sites;
[0053] a translator which converts an input comprising business information into a WWW site address, using said database; and
[0054] a user information database,
[0055] wherein said translator utilizes said user information database for the conversion.
[0056] Preferably, said user database comprises a user's previous desired conversions. Alternatively or additionally, said user database comprises a user's geographical location.
[0057] There is also provided in accordance with a preferred embodiment of the invention, a system including a server as described above and a client which provides said input to said server and displays a WWW page indicated by said address.
[0058] There is also provided in accordance with a preferred embodiment of the invention, a server comprising:
[0059] a database associating information with WWW sites;
[0060] a user information database; and
[0061] a translator which converts input information provided to it, into a WWW site address, using said database and said user database.
[0062] Preferably, said input information comprises business information. Alternatively or additionally, said input information comprises domain name information. Alternatively or additionally, said input information comprises URL information.
[0063] There is also provided in accordance with a preferred embodiment of the invention, a software unit for integrating with an existing browser, comprising:
[0064] a first module adapted to be integrated with said browser and which adds at least one functionality to a user interface of said browser; and
[0065] a second module which communicates with a remote site having stored therein information,
[0066] wherein said second module uses said communication to retrieve at least some of said information to perform said added functionality.
[0067] Preferably, said functionality comprises sending an e-mail to an owner of a site and wherein said information comprises an association between a site and an e-mail address of the owner thereof. Alternatively or additionally, said functionality comprises a poll answering interface and wherein said information comprises at least one poll question to display. Alternatively or additionally, said functionality comprises translating partial information into WWW addresses and wherein said information comprises an association between partial information and WWW addresses.
[0068] In a preferred embodiment of the invention, the unit comprises a third module which updates said information responsive to input entered at said browser. Alternatively or additionally, said remote site performs an operation requested by said functionality, responsive to said user information database. Preferably, said remote site performs a matching between partial entered information and a business information database, responsive to information associated with a user of said browser. Alternatively or additionally, said remote site sends credit card information to a second remote site, responsive to said functionality and to said information associated with a user of said browser.
[0069] In a preferred embodiment of the invention, said functionality does not affect a visual format of a GUI (Graphical User Interface) of said browser, when said functionality is not in use. Alternatively, said functionality does not affect a visual format of a GUI (Graphical User Interface) of said browser, when said functionality is in use.
[0070] There is also provided in accordance with a preferred embodiment of the invention, a software unit comprising:
[0071] a first module which receives, from a browser, a WWW address which does not meet WWW addressing standards;
[0072] a second module which translates said address into a WWW address which meets WWW addressing standards; and
[0073] a third module which instructs said browser to display a page associated with said translated WWW address.
[0074] Preferably, said second module performs said translation using a remote translation service. Alternatively or additionally, said first module impersonates a TCP/IP stack. Alternatively or additionally, said first module impersonates a HTTP service handler. Alternatively or additionally, said first module impersonates a DNS server. Alternatively or additionally, said first module steals a user input from said browser. Alternatively or additionally, said third module utilizes an OLE/DDE service. Alternatively or additionally, said translated address comprises a complete URL. Alternatively or additionally, said unit comprises an upload module which provides site accessing information to uploaded to a remote computer. Alternatively or additionally, said unit comprises a page generation module which generates a WWW page in response to said non-standard WWW address. Preferably, said generated WWW page comprises a list of possible WWW pages.
[0075] Alternatively or additionally, said generated page comprises a directory of a plurality of pages in a particular site. Alternatively or additionally, said generated page comprises at least one advertisement. Alternatively or additionally, said generated page displays a request for more information. Alternatively or additionally, said generated page is generated locally, i response to a request for a remote WWW address.
[0076] In a preferred embodiment of the invention, said unit comprises a messaging module which displays a message responsive to non-availability of a required WWW page. Alternatively or additionally, said unit comprises an e-mail module which corrects e-mail addresses, responsive to information associated with e-mail addressees.
[0077] In a preferred embodiment of the invention, said unit is a separately compiled software.
[0078] There is also provided in accordance with a preferred embodiment of the invention, a computer readable medium having encoded thereon a representation of a software unit as described above.
[0079] There is also provided in accordance with a preferred embodiment of the invention, a method of WWW page retrieval from a web site, comprising:
[0080] entering information associated with the site;
[0081] spell correcting said information; and
[0082] displaying a page responsive to said information, using a browser.
[0083] Preferably, spell correcting comprises correcting transliteration errors. Preferably, said information comprises a URL.
[0084] There is also provided in accordance with a preferred embodiment of the invention, a method of accessing an Internet resource, comprising:
[0085] entering information, which information does not comprise even a partial address for said resource; and
[0086] accessing said resource responsive to said information, without any additional user intervention, beyond said entering,
[0087] wherein said resource comprises a news group.
[0088] There is also provided in accordance with a preferred embodiment of the invention, a method of e-mail addressing, comprising:
[0089] entering an incorrect e-mail address, which does not form an alias, a portion or a nickname of a valid e-mail address;
[0090] automatically correcting said address, using information at a first, remote, location; and
[0091] sending an e-mail message to a second remote location, via an Internet, using said corrected address.
[0092] Preferably, said incorrect e-mail address comprises information associated with a desired e-mail addressee. Preferably, said information comprises at least a portion of a geographical address. Alternatively or additionally, said information comprises at least a portion of a telephone number.
BRIEF DESCRIPTION OF THE DRAWINGS
[0093] The present invention will be more clearly understood from the following detailed description of the preferred embodiments of the invention and from the attached drawings, in which:
[0094] FIG. 1 is a schematic block diagram of a site translator configuration, in accordance with a preferred embodiment of the invention;
[0095] FIG. 2 is a schematic block diagram of a site translator configuration, in accordance with another preferred embodiment of the invention;
[0096] FIG. 3 is a schematic block diagram of a site translator configuration, in accordance with another preferred embodiment of the invention;
[0097] FIG. 4 is a schematic block diagram of a site translator configuration, including a data server, in accordance with another preferred embodiment of the invention;
[0098] FIG. 5 is a schematic block diagram of a site translator configuration, including a domain name server, in accordance with another preferred embodiment of the invention;
[0099] FIG. 6 is a flowchart of a method of obtaining a WWW page, in accordance with a preferred embodiment of the invention; and
[0100] FIG. 7 is a schematic block diagram of a configuration including a client, a data server and a remote site, in accordance with a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0101] One aspect of the present invention relates to a method of enabling a user to enter a substantially free-form designation of a WWW site, preferably in the user's native language, and directly obtain the information from the site, without the necessity of using a search engine and/or an exact site address.
[0102] FIGS. 1-5 are schematic block diagrams of several methods of configuring a system in accordance with this aspect of the present invention. FIG. 6 is a flowchart of a method of obtaining a WWW page, in accordance with a preferred embodiment of the invention. A user enters the information by which he wishes to obtain a WWW page ( 60 ). This information is preferably matched to a database ( 62 ), as a result of which an IP address is generated ( 64 ). The page is then obtained automatically using the IP address and is preferably displayed on the user's computer ( 66 ). The various configurations of FIGS. 1-5 , determine how and by what hardware each of these steps is performed.
[0103] In FIG. 1 , a system 11 includes a browser 10 , at which a user enters his request, a translator 12 which aids in converting this request into an IP address and a remote site 14 , which hosts a desired WWW page. In a preferred embodiment of the invention, the translator masquerades as a TCP/IP stack (preferably Winsock in Windows 95). Alternatively, the translator is a proxy for the client machine. Such a proxy may be connected by a local network to the client machine and/or may be at the user's ISP (Internet Service Provider) and/or may be a remote machine, anywhere on the Internet. It should be noted that, in some preferred embodiments of the invention, all communications, in both directions, pass through the translator. Alternatively, only outgoing communications from the browser will go through the translator.
[0104] In FIG. 2 , a system 21 includes a translator 22 which is in direct communication with a browser 20 and a remote site 24 which is in direct communication with browser 20 . In this embodiment of the invention, browser 20 communicates with a local translator, which converts free-form entered domain name addressing into standard URLs. In accordance with one preferred embodiment of the invention, the translator is integrated as a module of the browser. Alternatively or additionally, the connection to the translator is patched into the browser. Alternatively or additionally, the translator communicates with the browser through existing hooks in the browser, such as the OLE/DDE protocol, under the Windows operating system. In a preferred embodiment of the invention, the browser contacts the translator if the entered address does not match certain criteria, such as form and character set.
[0105] In a preferred embodiment of the invention, the translator uses a local translation database. Preferably, this database is updated by an external server, either automatically, or by a user request. In a preferred embodiment of the invention, a user may enter a personal preference for an association between a URL/domain name and partial and/or native language information. In one preferred embodiment of the invention, the local database comprises host alias files. In one preferred embodiment of the invention, one or more of these files are replaced by updated files. Alternatively, the translator preferably includes an automatic application that downloads updates from a central server and updates the local files.
[0106] FIG. 3 illustrates a system 31 , in which a translator 32 acts as a front end to a browser 30 , which downloads Web pages from a remote site 34 . In accordance with one preferred embodiment of the invention, translator 32 includes a separate input window, which is preferably overlaid on a portion of the browser window. Preferably, this separate window remains on top on the browser and at a fixed relationship to at least one feature of the browser display. In a preferred embodiment of the invention, this window provides font support and data entry support for non-Latin character sets, even if the underlying browser and/or operating system do not. Preferably, such support includes support for languages which are not entered as single characters from the left to the right, for example Hebrew and Arabic, which are entered right to left and Chinese pictograms, which are composed. Alternatively or additionally, translator 32 is hidden from the user, so that it appears to the user that he is working with and entering information directly into the browser. In one preferred embodiment of the invention, a transparent window is overlaid on the browser address entry window. Alternatively or additionally, the translator steals the keystrokes from the browser, preferably by changing the window focus through the operating system. In a preferred embodiment of the invention, the translator sends the keystrokes to the browser, so that they are displayed, but performs a translation of the keystrokes and instructs the browser to use the addressed obtained by translation and ignore what was typed. Alternatively, the translator only steals the “return” key and at that key, reads the location entered into the browser location window and performs the translation. In a preferred embodiment of the invention, the translator displays the translated URL and/or IP address. Preferably, this information is displayed in the browser location window. Alternatively, it is displayed in a status area associated with the browser and/or with the translator. In a preferred embodiment of the invention, both the original and the translated addresses are displayed side by side, for the user to learn.
[0107] FIG. 4 illustrates a connection between a translator 42 and a data server 46 , in accordance with a preferred embodiment of the invention. In many of the above-described embodiments, translator 42 need not actually perform the translation itself. Rather, the input entered by the client is transmitted by translator 42 to a data server 46 , which preferably performs the translation. Data server 46 returns a URL and/or an IP address to translator 42 , which can then obtain data, either directly or through the browser, from a remote site 44 .
[0108] FIG. 5 illustrates the integration of a translator 52 with a domain name server 58 , in accordance with a preferred embodiment of the invention. When a browser 50 desires to connect to a remote site 54 , the browser (or an installed TCP/IP stack) sends the domain name to DNS server 58 , to be translated into an IP address. In accordance with one preferred embodiment of the invention, DNS server 58 utilizes a translator 52 to perform address translation for domain names that do not meet certain criteria. Such a translator may be local to the name server, such as on a local network or may be a remote service, accessed through a dedicated line or through the Internet. Alternatively, the DNS may be modified to perform the translation, preferably using look-up tables, but possibly using a pattern matching system. In a preferred embodiment of the invention, a plurality of translators are arranged in a hierarchical manner, similar to domain name servers, so that if a name is not found on one translator, other translators are queried. Preferably, this hierarchical structure utilizes the configuration and protocols used for existing domain name servers.
[0109] In an alternative embodiment of the invention, addresses to be resolved are passed first or only to the translator. In one preferred embodiment of the invention, the translator acts as a DNS. Preferably, the translator is registered as a primary DNS. Preferably, the translator translates only non-standard domain names, and passes standard domain names to the DNS. Alternatively or additionally, the translator acts as a filter, which converts non-standard domain names and/or free-form information into standard domain names, which are then passed to the DNS to be converted into IP addresses. In one preferred embodiment of the invention, the translator is in the gateway to a DNS server local network.
[0110] In a preferred embodiment of the invention, where the non-standard URL must pass through standard components, the non-standard URL is preferably encoded so that it is not modified by such components, for example, by encoding the non-ASCII characters and/or by replacing empty spaces with fill characters. One example of a standard component is a browser, which may attempt to parse the input, instead of simply sending it to the DNS. Encoding may be required in order to avoid error detection and address completion mechanisms which may be implemented in a particular browser. Such encoding is preferably performed using a front end, such as described above and/or a patch to the browser.
[0111] In a preferred embodiment of the invention, the translator is used to convert the entire URL, not just the domain name, into a proper address. In some cases, a native language expression will map to a particular page at a remote site, the address of which the translator will be required to return to the browser. In a preferred embodiment of the invention, the DNS protocol is modified to allow the transmission of the entire address. Alternatively, a separate connection is opened between a translator portion resident at the browser and a translator portion resident at the DNS, through which connection such information is passed. Alternatively, two translators are used, one for the domain name portion and one for the rest of the URL. Preferably, both translators are provided with the same native language and/or free-form expression and one returns the IP address and one returns the rest of the URL. Preferably, these two translators are synchronized so that they provide a single complete URL. In a preferred embodiment of the invention where a proxy server is used, the proxy server can be used to split the URL and track its parts. Preferably, the proxy server provides a dummy IP address to the browser, when it is presented with a free form and/or native language expression and/or domain name by the browser. When that dummy address is detected by the proxy server, it may be replaced with the correct IP address and the correct other portions of the URL.
[0112] In a preferred embodiment of the invention, when a proper URL is passed to the translator, the translator returns it unchanged and/or passes it to a DNS to be translated. Alternatively, the address may be used as a key-word which is used by a user to indicate a site within a domain, for example, “www.microsoft.com software download”.
[0113] In accordance with a preferred embodiment of the invention, the translator may perform one or more of the following functions:
[0114] (a) Correct spelling errors, especially those caused by transliteration errors. As a result, many near misses in site address entry will connect to the correct site.
[0115] (b) Accept words in any order. Preferably, these words are used to search a database in which each word and/or pattern is associated with a particular remote site.
[0116] (c) Find a site based on an (street/P.O. Box/e-mail) address of the site owner, and/or his telephone or fax numbers and/or a product, service name and/or trademark owned by the site owner and/or any particular information associated directly or indirectly with the site owner/operator. In a preferred embodiment of the invention, the (user's) focus is on the site itself and not on its owner. Thus, the information will be associated with the type/content/usage and/or information found in the site. In one example, the user may enter “freeware and software download center in Oakland” and the translator will locate a particular site and display it.
[0117] (d) Use field matching, for example “name=ibm”.
[0118] (e) Request additional information.
[0119] (f) Generate a page with a list of possible WWW pages. Preferably, such a page will include only sites which are registered with a particular translation service. Preferably, the site owners will also register a graphical representation by which they wish to be displayed on the generated page. Such a page may also include advertisements. It should be appreciated that such a page may be generated locally, as a result of a local search, without actually sending any information out to the Internet. Thus, the page generation and display may be very rapid. In a preferred embodiment of the invention, the user will try out several of the sites and then indicate to the translator which site was the “correct” one. Thereafter, upon entering the same partial information, the site will be directly connected to. Alternatively or additionally, this selection will be used to generate a user profile and/or to aid in matching partial information with other sites. Preferably, the translator uploads these selections to the data server.
[0120] (g) Learn a user's particular associations. In a preferred embodiment of the invention, a local database is maintained in which each partial entry by a user is associated with the actual site that the user connected to. Thereafter, when the user enters the partial information, the site can be connected to without any additional input by the user. Alternatively, every such choice is registered with a remote translator, which, when it receives partial information, performs indexing responsive to the identity of the remote user. In a preferred embodiment of the invention, each user on a particular machine can set up a profile of partial information matching. Preferably, a user can actively register certain associations.
[0121] (h) Perform a matching operation based on the geographical location of the user. For example, entering “Pizza store” will generate a different web site connection, based on where the connection is from. For example, a user in Brighton, Mass. will be directed to a different pizza store from a user in downtown Boston, even if both stores belong to the same franchise. Preferably, a user enters his computer's location, during configuration and/or at the beginning of the session, so that the client computer transmits its location to the translator. Preferably, a resident portion of the translator performs this transmission. Alternatively to a geographical location, a logical location may be used. Alternatively or additionally, sites are located based on them being associated with a user profile. In a preferred embodiment of the invention, a user profile is defined based on the user belonging to a certain customer club. Alternatively or additionally, the profile may be generated responsive to his age and/or previous browsing habits.
[0122] (i) Perform an automatic web search and return the address of a single hit.
[0123] (j) Provide an alternative page in cases where a page cannot be found. Preferably, when such an alternative page is provided, the user is informed, either by the browser or by a special pop-up message window generated by a resident portion of the translator.
[0124] (k) Parse a natural language query, for example “get me a pizza store”. Alternatively or additionally, a command language can be used, for example, SQL.
[0125] (l) Translate only a domain name and provide in response a list of the sites that are registered under that domain name. For example, entering “Microsoft Inc.” could generate a list of sites in the domain “microsoft.com”, which are registered with the translation service.
[0126] In a preferred embodiment of the invention, each native language name and/or index word is associated with a plurality of sites. For example, many sites will be associated with “pizza”. However, a particular site is designated the default site, for use if there isn't enough information available to otherwise uniquely select a single site.
[0127] In accordance with one preferred embodiment of the invention, the translator or a portion thereof is embodied as an external box, which may be connected on a telephone line between a computer with a modem and a remote computer. Alternatively, it is integrated into the operating system of the user's computer.
[0128] In a preferred embodiment of the invention, the translator is embodied as a distributed system. In one example, the matching an/or parsing is performed at one location, possibly the user machine, while the address translation is performed at a remote machine.
[0129] In a preferred embodiment of the invention, a resident portion of the translator is activated whenever the browser is started. In a preferred embodiment of the invention, the resident translator can communicate with external sites for many purposes including, automatic version update of the translator and/or indexes and/or tables; uploading client related information, such as use statistics and site access statistics; download advertising material to be displayed at various times; and resolve problems using an external service.
[0130] In a preferred embodiment of the invention, the local translator portion provides language support for native language address entry, even if the browser and/or operating system do not.
[0131] FIG. 7 is a schematic block diagram of a configuration including a client 70 , a data server 72 and a remote site 74 , in accordance with a preferred embodiment of the invention. A resident translator portion at client 70 preferably maintains the connection with data server 72 . In one preferred embodiment of the invention, data server 72 transmits advertisements to the client. Alternatively or additionally, data server 72 transmits polls (for user response) to client 70 . Preferably, server 72 receives the responses to the polls directly through the translator and not through a remote site. Alternatively, the polls are displayed in the browser as WWW pages, rather than as separate windows.
[0132] In accordance with another preferred embodiment of the invention, data server 72 can be used as an intermediate between client 70 and remote site 74 , for the transfer of money. In a typical situation, if client 70 desires to make a purchase at remote site 74 , he will be required to transmit credit card details over an insecure link (the Internet). Preferably, client 70 performs the purchase through data server 72 , to which the credit card details have been previously downloaded and/or transmitted using a secure channel. The client transmits a product number and a remote site address to the data server and the data server performs the money transfer, preferably using a secure connection, but possibly using other means, for example, through a bank and/or a fax machine. Preferably, data server 72 verifies the identity of client 70 , using a portion of the translator resident at client 70 . In a preferred embodiment of the invention, the purchase is performed mostly automatically, by a user indicating to the resident portion of the translator, which product he wishes to purchase, preferably using a pointing device.
[0133] In a preferred embodiment of the invention, the translator adds icons and/or menus to the browser and/or overlays them on the browser window. Thus, functionality may be added to the browser. Additionally or alternatively to adding a button for purchasing, other buttons may be added, including, for example for sending e-mail to a site owner. Such additional functionalities preferably utilize information stored in the database, for example, the e-mail address of the site owner.
[0134] In a preferred embodiment of the invention, especially where the translator acts as a proxy server, the translator may be used to exercise parental control over the use of the client computer, for example to limit access to pornographic sites and/or money-spending sites. Preferably, the translator does not allow certain addresses to be translated. Preferably, each client has associated therewith a list of allowed web sites, a list of proscribed web sites and/or a site rating, below which, access is allowed and above which, access is not allowed. The translator preferably includes or connects to a service that provides ratings for sites and/or domain names.
[0135] In a preferred embodiment of the invention, the translator performs password entry for sites that require a password. Instead of a user being required to recall a separate password and/or user name for each service to which he subscribes, when the user enters input associated with that site, the translator automatically enters the user name and/or password. Different nicknames may be associated with different users for the same page. Preferably, the page with the password entry is also displayed to the user, but without requiring any input. Preferably, the passwords are maintained on the client machine, due to their sensitivity. Alternatively or additionally, a user is required to enter a single password in order to activate this feature.
[0136] In a preferred embodiment of the invention, the translator is embodied as a remote translation service, with a local resident portion. Preferably, the remote portion is maintained as a network of hierarchical translation servers. In a preferred embodiment of the invention, the remote portion preferably includes a computer, a user information database, a site-owner information database, a search engine which searches the site-owner information data base, a HTTP server, a HTML generator and a client response portion, which controls the other components of the server, responsive to input received from the client.
[0137] In a preferred embodiment of the invention, the client portion of the translator is embodied as a program that masquerades as a HTTP handler for the browser. Preferably, the translator registers itself as the HTTP handler. When the browser requests a page, the resident translator handles the translation, through the Internet and/or using a local database of association, and then commands the browser, preferably through a DDE/OLE connection to obtain the particular page. Preferably, the local database includes user specific associations and/or is a cache of recently and/or commonly used addresses. Preferably, when a user requests a specific page, his local database is updated, preferably by a remote translator portion, to reflect an association between that particular choice and the information entered. In some browsers, entry of a free-form URL will automatically cause a search-site to be connected to. Preferably, the resident portion of the translator captures such requests and performs a translation instead.
[0138] In some embodiments of the invention, words in the free-form input will be separated by a separator other than a blank, so that the browser does not cause problems with the existence of blanks in what is supposed to be a URL.
[0139] In a preferred embodiment of the invention, sites are manually registered with the translation service. A site-owner fills out a form, preferably on the Internet, and requests that the translator recognize a particular site. Preferably, the site owner suggests key words to be used in indexing. Alternatively, the owner of the translator enters this information. Alternatively, the translator automatically identifies domains and generates index terms for the domains. Preferably, the site-owner database is update able by the site owners, to add indexing terms. Alternatively, if a large number of users indicate that they identify a particular site with particular index terms and/or keywords, this information is preferably entered into the site-owner database. A preferred way of making such an indication is by accumulating the choices made by users that entered partial information and received a list of possible sites. The site which is most often chosen for a particular group of key words is preferably made the default choice (preferably, providing that the user does not have a personal selection).
[0140] In a preferred embodiment of the invention, users may also register by filing out an automated form.
[0141] It should be appreciated that the present invention has been described mostly with relation to Web browsers. However, in other preferred embodiments of the invention, the methods and apparatus described herein may be applied to other types of Internet applications, which require domain name resolution, such as News services and FTP services. In addition, these methods may be applied to translating domain name portions of e-mail addresses. However, in e-mail name translation, the aspect of directly accessing data of some embodiments of the invention, may not apply. Additionally, although some software elements are described herein as including a plurality of modules, it should be appreciated that these modules may be merged and/or sub-divided into modules, in some embodiments of the present invention.
[0142] It should be appreciated that the above described methods of address manipulation, as described hereinabove contain many features, not all of which need be practiced in all embodiments of the invention. Rather, various embodiments of the invention will utilize only some of the above described techniques, features or methods and or combinations thereof. In addition, although the above description is focused on methods, apparatus for performing these methods is also considered to be within the scope of the invention.
[0143] It will be appreciated by a person skilled in the art that the present invention is not limited by what has thus far been described. Rather, the present invention is limited only by the claims which follow. When used in the following claims, the terms “comprises”, “comprising”, “includes”, “including” or the like means “including but not limited to”.
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Systems and methods for WWW page retrieval from a web site, performing the steps of receiving information associated with the site; and directly displaying said page, using a browser, without any additional user intervention.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a Non-Prov of Prov (35 USC 119(e)) application 60/952,121 filed on Jul. 26, 2007, and application 61/080,069 filed on Jul. 11, 2008, both incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Atmospheric wind observations with passive optical remote sensing techniques that measure Doppler shift have a long heritage. To date, space based optical measurements of winds in the Earth's atmosphere have been performed using either Fabry-Perot interferometers or Michelson interferometers. Both instrument types use a limb viewing geometry to detect the Doppler shift of discrete atmospheric emission lines caused by the bulk velocity along the line of sight at the tangent layer. The horizontal wind vector is determined by combining two measurements of the same air mass with orthogonal look direction, typically taken several minutes apart, 45° and 135° from the velocity vector of the satellite.
Fabry-Perot Heritage
[0003] As discussed in Hayes P. B. et al., “The High-Resolution Doppler Imager on the Upper Atmosphere Research Satellite”, J. Geophys. Res., 98, 10713-10723, 1993, and Killeen T. L. et al., “TIMED Doppler Interferometer (TIDI), Proc. SPIE, 3756, 289-315, 1999, the High-Resolution Doppler Imager (HRDI) on NASA's Upper Atmospheric Research Satellite (UARS) and TIDI on NASA's Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission utilize a triple and a single Fabry-Perot interferometer, respectively, to measure emissions between 550-900 nm. The Fabry-Perot instruments utilize one or multiple etalons in series to isolate and spectrally resolve the emission line(s) of interest. The spectrum over a narrow wavelength range is obtained directly by imaging the ring pattern produced by the interferometer on a position sensitive detector. Once the spectrum is obtained, the wind speed can be derived from the line position. The temperature can be determined from either the line width or a line ratio. The biggest technical challenge for the Fabry-Perots lies in achieving the required etalon alignment tolerances (better than ˜λ/20) and maintaining this alignment during flight. Although many resolution elements are measured in parallel, the solid angle Ω for a single resolution element is determined by the resolving power R (i.e. Ω=2π/R) which can be small at the resolution required for Doppler measurements. Since the high resolving power necessitates a small solid angle, a large interferometer aperture may be required to obtain adequate signal on faint emissions. This results in a larger, heavier instrument.
Stepped Michelson Heritage
[0004] As discussed in Shepherd et al., “WINDII, the Wind Imaging Interferometer on the Upper Atmosphere Research Satellite”, J. Geophys. Res., 98, 10725-10750, 1993 (“Shepherd et al.”), the Wind Imaging Interferometer (WINDII) on UARS uses an all-glass, field widened, chromatically, and thermally compensated, phase-stepped Michelson interferometer (also termed Stepped Fourier Transform Spectrometer or stepped FTS). Several other versions of phase-stepped interferometers have been built or proposed for the measurement of telluric winds (see Babcock et al., “A Prototype Near-IR Mesospheric Imaging Michelson Interferometer (MIMI) for Atmospheric Wind Measurement,” Eos Trans. AGU, 85(47), Fall Meet. Suppl., Abstract SA41A-1040, 2004, and Ward et al., “The Waves Michelson Interferometer: A visible/near IR interferometer for observing middle atmosphere dynamics and constituents,” Proc. SPIE Int. Soc. Opt. Eng., 4540, 100, 2001. (“Ward et al. 1”)) and winds on Mars (see Ward, W. E. et al., “An imaging interferometer for satellite observation of wind and temperature on Mars, the Dynamics Atmosphere Mars Observer (DYNAMO),” Proc. SPIE Int. Soc. Opt. Eng., 4833, 226, 2002 (“Ward et al. 2”)).
[0005] The basic principle behind all phase stepped Michelson interferometers is to measure a minimum of three, but typically four, interferogram points of a single isolated atmospheric emission line. The phase points are spaced by ˜λ/4 (90°) about a step (or offset) in optical path difference (OPD) that is large enough to be sufficiently sensitive to both wind speed, which results in a phase shift at high OPD, and temperature, which results in a variation in modulation depth. This principle is illustrated in FIG. 1 . It shows a schematic interferogram as it would be recorded by a conventional scanning Michelson interferometer viewing an isolated, single Gaussian (temperature broadened) emission line. Zero path difference is at the center of the plot with maximum path difference at the edges. The carrier frequency of the fringe pattern is determined by the central wavenumber of the emission which is Doppler shifted by the wind speed. For a predominantly temperature broadened line, the width of the interferogram envelope is a measure of the temperature, with a higher temperature corresponding to a narrower envelope. The thick line in FIG. 1 illustrates the residual obtained by taking the difference between two interferograms each corresponding to a different wind speed, which causes them to have slightly different carrier frequencies. The thin curve shows the intensity vs. optical path difference for a Gaussian emission line as it would be recorded by a scanning Michelson interferometer scanned over the entire modulated path difference. Zero path difference is at the center of the plot where the visibility of the fringes is maximal. The maximum response of the measurement to wind speed is at path difference P OPT where the amplitude of the signal difference is maximal. Assuming a temperature broadened, Gaussian line profile with width σ D :
[0000]
σ
D
=
σ
0
kT
mc
2
(
1
)
[0000] the optimum path difference is:
[0000]
P
OPT
=
1
2
πσ
D
(
2
)
[0000] where σ 0 is the wavenumber of the line center, k is Boltzmann's constant, m is the molecular or atomic mass of the emission source, T is the temperature, and c is the speed of light.
[0006] Note that the fringe frequency in FIG. 1 has been greatly reduced for illustrative purposes. A real interferogram taken with a Michelson interferometer for a near infrared (NIR) emission line would produce ˜10 5 fringes between path differences 0 and P OPT under typical atmospheric conditions.
[0007] Determining Doppler shifts with a phase-stepped Michelson requires the isolation of a single emission line with a pre-filter. A fit of the interferogram phase at the four measured samples is then possible, which can subsequently be used to determine the Doppler frequency shift. If the line is close to other emissions in the spectrum, the pre-filter has to be extremely narrow, which can be achieved by an additional Fabry-Perot etalon prefilter, with all of its attendant difficulties and the resulting reduction in throughput (see Ward, W. E. et al., “The Waves Michelson Interferometer: A visible/near IR interferometer for observing middle atmosphere dynamics and constituents,” Proc. SPIE Int. Soc. Opt. Eng., 4540, 100, 2001, and Ward, W. E. et al., “An imaging interferometer for satellite observation of wind and temperature on Mars, the Dynamics Atmosphere Mars Observer (DYNAMO),” Proc. SPIE Int. Soc. Opt. Eng., 4833, 226, 2002). Using an a priori line shape assumption (e.g. Gaussian or Voigt), the line width can be determined from the interferogram modulation, which yields the temperature for a predominantly temperature broadened line.
[0008] Several stepped FTS techniques have been used to measure Doppler shifts. The WINDII instrument uses piezoelectric actuators to move one mirror of the interferometer (Shepherd et al.). The MIMI (Mesospheric Imaging Michelson Interferometer) instrument uses a segmented mirror with four sections at different OPD, which avoids moving the mirror (Babcock et al.). The WAMI (Waves Michelson Interferometer) version, designed for the Earth's atmosphere, proposes a moving, segmented mirror, allowing the simultaneous measurement of two emission lines with a two step mirror scan (Ward et al. 1). A phase-stepped Michelson interferometer has also been proposed for Mars using a non-segmented, mirror moved by piezo actuators.
[0009] Disadvantages of FTS as discussed above include the need for moving parts (in case of a dynamically stepped system) and the reduced throughput due to the necessary pre-filter leading to an increase in the size and weight of the overall payload.
Spatial Heterodyne Spectroscopy Heritage
[0010] Spatial Heterodyne Spectroscopy (SHS) was conceived in the late 1980s and was mainly facilitated by the availability of array detectors (see Harlander J. M., R. J. Reynolds, and F. L. Roesler, “Spatial heterodyne spectroscopy for the exploration of diffuse interstellar emission lines at far ultraviolet wavelengths,” Astrophys. J., 396, 730-740, 1992, and Harlander J. M. et al., “Field-Widened Spatial Heterodyne Spectroscopy: Correcting for Optical Defects and New Vacuum Ultraviolet Performance Tests,” Proc. SPIE Int. Soc. Opt. Eng., 2280, 310, 1994). The basic principle of SHS is that the path difference that is typically scanned by a Michelson interferometer is imaged onto a position-sensitive detector without moving parts. This is accomplished by replacing the return mirrors in a Michelson interferometer with Littrow diffraction gratings and imaging the gratings onto the detector. SHS instruments measure all interferogram samples simultaneously in the spatial domain using a line or array detector. They heterodyne the spatial fringe frequency around the Littrow wavenumber, CL, of the gratings, which allows the optimum use of the number of array detector elements. As a result, SHS allows the design of compact, high throughput, high resolution spectrometers without moving parts. To date, SHS has mainly been used in the UV and visible. The first orbital flight of an SHS was performed in 2002 with the proof of concept mission of SHIMMER (Spatial Heterodyne Imager for Mesospheric Radicals) on the Space Shuttle (see Harlander J. M., F. L. Roesler, J. G. Cardon, C. R. Englert, and R. R. Conway, “SHIMMER: A Spatial Heterodyne Spectrometer for Remote Sensing of Earth's Middle Atmosphere,” Appl. Opt., 41, 1343-1352, 2002, Cardon J. G., C. R. Englert, J. M. Harlander, F. L. Roesler M. H. Stevens, “SHIMMER on STS-112: Development and Proof-of-Concept Flight, AIAA Space 2003 Conference & Exposition,” AIAA Paper 2003-6224, 2003, and Englert C. R., J. M. Harlander, J. G. Cardon, and F. L. Roesler, “Correction of phase distortion in spatial heterodyne spectroscopy,” Appl. Opt., 43, 6680-6687, 2004). An improved version of SHIMMER including a monolithic interferometer was placed in low-earth orbit on STPSat-1 in early 2007 (see Harlander J. M., F. L. Roesler, C. R. Englert, J. G. Cardon, R. R. Conway, C. M. Brown, J. Wimperis, “Robust monolithic ultraviolet interferometer for the SHIMMER instrument on STPSat-1 ,” Applied Optics, 42, 2829-2834, 2003).
[0011] A disadvantage of conventional SHS is its limited resolving power, which is typically not high enough to measure the Doppler shift caused by winds.
[0012] It would therefore be desirable to provide a system for wind measurements that is more robust and lighter in weight that present systems.
BRIEF SUMMARY OF THE INVENTION
[0013] According to the invention, a Doppler Asymmetric Spatial Heterodyne (DASH) spectrometer includes an input aperture for receiving an input light; a collimating lens for collimating the input light into a collimated light; offset establishing means, including at least one grating, for i) receiving and splitting the collimated light into a first light wavefront in a first optical path and into a second light wavefront in a second optical path ii) establishing an offset in a light wavefront path distance between the first and second optical path light wavefronts, and iii) diffracting and recombining the first and second optical path light wavefronts into an interference wavefront to form an interference image that includes a plurality of phase points of a heterodyned interferogram measured simultaneously over the path distance offset; and an output optics section comprising a detector for receiving the interference image and outputting an interference image pattern.
[0014] In one embodiment, the offset establishing means is a Kösters prism, a single grating; and a field-widening prism positioned between the Kösters prism and the single grating.
[0015] In another embodiment, the offset establishing means is a beamsplitter, a first grating positioned in the first optical path for reflecting the first collimated light portion back to the beamsplitter as the first optical path light wavefront, and a second grating positioned in the second optical path for reflecting the second collimated light portion back to the beamsplitter as the second optical path light wavefront. The second grating is positioned at a greater distance than the first grating with respect to the beamsplitter to produce the offset in the light wavefront path distance between the first and second optical path wavefronts.
[0016] DASH is typically lighter and more robust than competing designs. DASH does not require any moving optical components and can be built in a compact, robust way, which makes it suitable for space flight. DASH includes the advantages of SHS, robustness, small size, and sensitivity, while extending its capability to a resolving power high enough to measure the Doppler shift caused by winds.
[0017] Like stepped FTS, DASH can be field widened and has large interferometric throughput, exhibiting good etendue. In addition, DASH can accept multiple emission lines in the passband, eliminating the use of ultra narrow filters and their concomitant reduction in throughput and temperature sensitivity. The multi-line capability allows the simultaneous tracking of the “zero wind phase” by superimposing a known emission line onto the atmospheric scene, enabling the tracking of thermal instrument drifts.
[0018] DASH records several hundred interferogram points within an optical path difference interval centered on a path offset, producing increased immunity to ghost fringes and background features which are more difficult to identify if only four phase points are available.
[0019] Atmospheric temperature information can be retrieved in addition to the wind field information using the temperature dependence of line strength ratios as well as the interferogram contrast which includes information about the line shape.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic interferogram recorded by a conventional scanning Michelson interferometer viewing an isolated, single Gaussian (temperature broadened) emission line and the residual obtained by taking the difference between two interferograms each corresponding to a different wind speed;
[0021] FIG. 2 is a schematic diagram of a DASH system according to the invention;
[0022] FIG. 3 is an interference pattern for a monochromatic source imaged according to the invention;
[0023] FIG. 4 is a schematic diagram of a non-field-widened DASH interferometer according to the invention;
[0024] FIG. 5 shows two interferograms, one for a non-Doppler shifted line, one for a Doppler shifted line according to the invention. The lower trace shows the difference of the two interferograms on an enhanced scale;
[0025] FIG. 6 is a schematic diagram of a field-widened DASH interferometer according to the invention;
[0026] FIG. 7 is a schematic diagram of a laboratory light source set-up to produce an alternating shifted/non-shifted line signal to test a DASH laboratory interferometer similar to the one shown in FIG. 4 ;
[0027] FIG. 8 is a typical dark and flat field corrected fringe image of a monochromatic source according to the invention;
[0028] FIG. 9 shows an interferogram according to the invention in the top panel, the complex Fourier transform of the interferogram in the middle panel, where the dark line is the real part and the light line is the imaginary part, and the retrieved phase in the bottom panel;
[0029] FIG. 10 shows the mean phase measurements obtained with a laboratory DASH setup and an alternating monochromatic source as shown in FIG. 7 . The bottom panel shows the same data set after drift correction;
[0030] FIG. 11 is a flat fielded interferogram image with two lines in the passband according to the invention;
[0031] FIG. 12 shows an interferogram according to the invention in the top panel for a two line source and the complex Fourier transform of the interferogram in the bottom panel, where the dark line is the real part and the light line is the imaginary part; and
[0032] FIG. 13 a schematic diagram of a field-widened DASH system employing a Kösters prism according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0033] As used herein, the term “field-widening prism” means a wedged, refractive element whose purpose is to increase the throughput of the system by reducing the path difference change between on and off-axis rays. Exemplary field-widening prisms include prisms typically manufactured from low-dispersion glass.
[0034] Referring now to FIG. 2 , a Doppler Asymmetric Spatial Heterodyne (DASH) spectrometer 100 includes input optics, an interferometer and output optics. The input optics include an input aperture 102 , and collimating lens 104 . The interferometer includes a beam splitter 106 , optional prisms 108 and 110 , grating 112 , and grating 114 . The output optics section 121 includes focusing lens 116 , collimating lens 118 and detector array 120 .
[0035] In operation, input light passes through input aperture 102 and diverges to collimating lens 104 . Collimated light λ 1 , includes an incident wave front 122 . Collimated light λ 1 , is then incident upon beam splitter 106 . Beamsplitter 106 splits the collimated light λ 1 into a light λ 2 in a first optical path (also termed a “first arm”) 123 of spectrometer 100 and into a light λ 4 in a second optical path (also termed a “second arm”) 129 . The light λ 2 in the first optical path 123 then traverses (optional) prism 108 that refracts it at an angle toward grating 112 . Grating 112 is tilted by the Littrow angle θ L ( 124 ) and reflects light λ 3 back through prism 108 and toward beam splitter 106 , where light λ 3 is partially reflected toward lens 104 and partially transmitted toward lens 116 . The output optics section 121 is designed to image the grating planes 112 and 114 onto the detector array 120 . Here, the partially transmitted light λ 6 includes a wave front 130 and is focused by lens 116 to a point 134 . The light λ 6 then diverges toward lens 118 to be imaged on detector array 120 . The light λ 4 in the second optical path 129 traverses (optional) prism 110 , which refracts it at an angle toward grating 114 . Grating 114 is tilted by the Littrow angle θ L ( 126 ) and reflects light λ 5 back through prism 110 and toward beam splitter 106 , where light λ 5 is partially transmitted toward lens 104 and partially reflected toward lens 116 . In the output optics section 121 , the partially reflected light λ 7 includes a wave front 128 and is focused by lens 116 to a point 134 . The light λ 7 then diverges toward lens 118 to be imaged on detector array 120 which records fringes of wavenumber-dependent spatial frequencies. Examples of suitable, currently available detector arrays are, depending on the wavelength region, one dimensional or two dimensional arrays of the following types: Charge-Coupled Devises (CCD) in the ultra violet, visible, and near infrared, Indium-Gallium-Arsenide (InGaAs)_arrays for the near infrared, Indium Antimonide (InSb) arrays for the near and mid infrared, or Mercury Cadmium Telluride (MCT) arrays for the near, mid and long wave infrared. The arrays typically have hundreds of elements (pixels) in at least one spatial dimension.
[0036] Wave front 128 constructively and destructively interferes with wave front 130 , such that that image detected by detector array 120 is an interference pattern. An example of such an interference pattern for a monochromatic source is illustrated in FIG. 3 . The characteristics of the pattern are based on the wavelength of the light λ 1 and the angle 132 between wave front 128 and wave front 130 . Angle 132 is mainly based on the frequency of the input light λ 1 and the structure and angle of gratings 112 and 114 . The asymmetrical configuration of the DASH invention is obtained where grating 114 is positioned further from the beamsplitter 106 than grating 112 , resulting in a step or offset in path difference. The path difference interval is determined by the grating angle. The invention improves over SHS in that the range of sampled path differences is offset from zero path difference. SHS positions the centers of both gratings the same distance from the beamsplitter, producing a two-sided, heterodyned interferogram with zero path difference at the center, and maximum path difference at the edges of the recorded image. DASH positions one of the gratings further from the beamsplitter than the other, in what is then an “asymmetric” interferometer configuration. The fringe pattern measured by DASH is a heterodyned interferogram obtained over a path difference interval (determined by the grating angle) centered on a large path difference offset or step (determined by the offset of one grating).
[0037] Typical atmospheric wind velocities cause atmospheric emission lines to be Doppler shifted by only a few parts in 108 . This small wavelength shift results in a small frequency change in the interferogram as recorded by an SHS, DASH, or FTS instrument. FIG. 3 shows an ideal interferogram of a single, infinitely narrow spectral line versus optical path difference and the interferogram of a slightly Doppler shifted line. As is well known, the small frequency change in the interferogram has a negligible effect for small optical path differences; however, at longer path differences it appears predominantly as a phase shift. The main objective of DASH is to measure this phase shift, thus it is sufficient to measure the interferogram at high optical path differences. Note that the brightness of the interferogram and the fringe contrast contain information about the density of the emitter and the line shape, just like in the stepped FTS case. In FIG. 3 , the darker line is an interferogram of an infinitely narrow spectral line, and the lighter line as an interferogram of a slightly Doppler shifted, infinitely narrow spectral line. This shows that the high resolution information about the exact line position and therefore the Doppler shift of the line is contained at high optical path differences. At large optical path differences, the predominant effect is a phase shift between the two fringe patterns that have slightly different frequencies.
[0038] The phase shift, δφ, of a single emission line as a function of the optical path difference, 2Δd, can be written as:
[0000] δφ=4 πΔd σ( v/c ) (3)
[0000] where σ is the non-Doppler shifted wavenumber of the emission line, v is the Doppler velocity and c is the speed of light.
[0039] Referring now to FIG. 4 , DASH 100 allows the measurement of the interferogram within a path difference interval around the path difference offset 2Δd. The difference between a conventional SHS interferometer and the DASH interferometer is the additional optical path difference offset (2Δd) in one of the interferometer arms, as shown. DASH can be explained assuming a plane wave front entering the interferometer shown as the vertical dashed line. The wave front is split at the beamsplitter 106 so that the two resulting beams illuminate the gratings 112 and 114 at the end of the interferometer arms. After being diffracted at the gratings 112 and 114 , the wavefronts return to the beamsplitter 106 and recombine. At this point, the two wave fronts are each tilted by the angle γ≈2 tan θ L [(σ−σ L )/σ] with respect to the optical axis and one wave front is delayed by the optical path offset 2Δd. Due to the wavelength dependent tilt of the wavefronts caused by the gratings, the detector array records a wavenumber dependent Fizeau fringe pattern, which is the Fourier transform of the incident spectral density heterodyned around the Littrow wavenumber σ L =1/(2g sin θ L ), where 1/g is the groove density of the gratings. The interferogram recorded by the DASH array detector can generally be written as:
[0000]
I
(
x
)
=
1
2
∫
0
∞
B
(
σ
)
[
1
+
cos
{
2
π
[
4
(
σ
-
σ
L
)
tan
θ
L
]
[
x
+
Δ
d
2
tan
θ
L
]
}
]
σ
(
4
)
[0040] where x is the location on the detector array 120 as indicated in FIG. 4 (x=0 is the center of the array), θ L is the Littrow angle of the gratings, B(σ) is the spectral density of the incident radiation and the magnification of the imaging optics (L 2 and L 3 in FIG. 4 ) is assumed to be unity. The sampled path difference interval, d, is:
[0000] 2(Δ d−W sin θ L )< d< 2(Δ d+W sin θ L ) (5)
[0000] where W is the beam width measured along each grating. The effective resolving power can be found using R=σ(4W sin θ L )≈2W/g. The resolving power is equivalent to the number of illuminated grating grooves. This is the same result as for conventional SHS.
[0041] In contrast to the typical stepped Michelson interferometer, DASH allows the simultaneous measurement of several hundred interferogram samples within the path difference interval defined in Eq. (5). This means that DASH can simultaneously measure multiple lines, including calibration lines that can be used to track instrumental drifts.
[0042] Optimum Path Difference Offset:
[0043] Atmospheric emission lines are subject to line broadening effects such as pressure and temperature broadening. Line broadening affects the envelope of the interferogram; a broader line corresponds to an envelope that decreases more rapidly with increading path difference. In general, this envelope function causes the interferogram contrast, or visibility, to decrease with increasing optical path difference as shown for a purely temperature broadened line in FIG. 5 . This effect competes with the increasing phase shift for increasing optical path difference (see Eq. (3)) so that there is an optimum path difference offset for which measuring the phase shift and thus the Doppler shift is most sensitive. We find this optimum path difference by maximizing the envelope of the difference between the interferograms of a Doppler shifted and non-shifted line (see FIG. 5 ). Maximizing the envelope, rather than the actual interferogram differences is appropriate since the DASH concept allows the simultaneous observation of many fringes, as discussed below. In FIG. 5 , in the upper part of the graph, the black line is the interferogram of a single, temperature broadened line, illustrating the decreasing contrast for increasing optical path difference is due to the finite line width of the emission line, while the lighter line is the interferogram of a slightly Doppler shifted emission line; in the lower part of the graph, the dark line is the difference between the two interferograms. The dotted vertical line indicates the optical path difference for which the envelope of the difference function is largest. Here, the measurement is most sensitive to the phase shift. For the example of a purely temperature broadened line, which has a Gaussian line shape proportional to exp[−(σ−σ 0 ) 2 /2σ D 2 ] and a width of:
[0000]
σ
D
=
σ
0
kT
mc
2
,
(
6
)
[0044] the optimum path difference is:
[0000]
2
Δ
d
OPT
=
1
2
πσ
D
(
7
)
[0045] where T is the temperature, m is the mass of the emitter, σ 0 is the wavenumber of the line center and k is Boltzmann's constant. Although Eq. (7) predicts the optimum path difference about which to make a Doppler measurement, practical concerns such as the size and sensitivity of the instrument may require the instrument be build with a non-optimum, typically smaller, path difference.
[0046] Finally, we point out that the optimum path difference only depends on the emission line shape. This is the case even if more than one line is within the passband, as is discussed below.
[0047] Phase (Doppler Shift) Determination:
[0048] We can simplify the DASH interferogram from several emission lines by writing:
[0000]
I
D
(
x
)
=
∑
j
S
j
[
1
+
E
j
(
x
)
cos
(
2
πκ
j
x
+
Φ
j
+
δϕ
j
)
]
=
∑
j
S
j
(
1
+
1
2
E
j
(
x
)
{
exp
[
(
2
πκ
j
x
+
Φ
j
+
δϕ
j
)
]
+
exp
[
-
(
2
πκ
j
x
+
Φ
j
+
δϕ
j
)
]
}
)
(
8
)
[0049] Where j indexes several lines in the passband, x is the location on the detector as shown in FIG. 4 , S j are proportional to the line brightness, E j (x) are the envelope functions that depend on the individual line shape and the path difference offset, κ j ≡4(σ j −σ L )tan θL are the heterodyned spatial fringe frequencies for each line center, σ j , Φ j ≡4π(σ j −σ L )Δd are additive phase terms, and δφ i are the phase shifts resulting from the Doppler shift of each line. Note that κ also changes with the Doppler shift of the line, but that effect is typically negligible for typical atmospheric wind speeds.
[0050] When the bandpass, Littrow wavenumber, and path difference interval are chosen appropriately (see below), the Fourier transform of Eq. (8) yields a complex spectrum with localized, well separated features around spatial frequencies +κ j and −κ j . The next step is to isolate one of these features, e.g. j=0, by zeroing out all spectral elements (including the ones at −κ 0 ) except the ones within a local region around +κ 0 . This step effectively eliminates all interferogram contributions (see Eq. (8)), except one of the exponential terms, so that after the inverse Fourier transform we get:
[0000]
I
D
0
(
x
)
=
1
2
S
0
E
0
(
x
)
exp
[
(
2
πκ
0
x
+
Φ
0
+
δϕ
0
)
]
=
1
2
S
0
E
0
(
x
)
[
cos
(
2
πκ
0
x
+
Φ
0
+
δϕ
0
)
+
sin
(
2
πκ
0
x
+
Φ
0
+
δϕ
0
)
]
(
9
)
[0051] Using Eq. (9), the phase term can now be calculated from the ratio of its imaginary and the real part:
[0000]
2
πκ
0
x
+
Φ
0
+
δϕ
0
=
arctan
(
(
I
D
0
)
ℜ
(
I
D
0
)
)
(
10
)
[0052] After subtraction of 2πκ 0 x+Φ 0 , which is also called the zero wind phase, we get the phase shift δφ 0 caused by the Doppler shift for this particular line. The speed between the emitter and the spectrometer can now be calculated using the phase shift δφ 0 and Eq. (3). The above procedure can be applied for all lines in the passband (j=0, 1 . . . ) yielding an independent velocity measurement for each line.
[0053] Alternatively to the technique described above, the phase shift δφ 0 can also be obtained by fitting the fringe pattern with an analytical function including δφ 0 as a parameter to be optimized.
[0054] We point out that the subtraction of the zero wind phase is a very critical step, since the zero wind phase is likely to be sensitive to instrument drifts. One method to determine the zero wind phase is to simultaneously observe a known, non-Doppler shifted reference line. With DASH one can, for example, use an in-situ calibration lamp that has one or more spectral lines in the passband and superimpose its signal onto the observed scene with an additional beamsplitter. This way every exposure includes a simultaneous zero wind calibration (see below).
[0055] Choice of Passband, Littrow Wavenumber, and Resolving Power:
[0056] To optimize the sensitivity of the atmospheric wind measurement, the choice of the passband depends on many factors such as the targeted emission spectrum, radiative transfer considerations, and/or detector performance to name only a few. Here, we focus on the considerations that are generally important for a DASH instrument rather than specific to a particular application.
[0057] First, one or more emission lines must be identified. If more than one line is chosen, they need to be well separated, i.e. their spectral spacing should be at least several times their line width. Second, the Littrow wavenumber and resolving power are chosen, which will constrain the number of illuminated grating grooves, the groove density and the grating angle (see Section 3 A) of the DASH interferometer. The choice should be made so that the observed emission lines correspond to well-separated spatial frequencies which can be easily isolated in the spectral domain as described in section “Phase (Doppler Shift) Determination” above. For example, assuming three emission lines at 6020 cm −1 , 6060 cm −1 , and 6085 cm −1 , a Littrow wavenumber of 6000 cm −1 , and a resolving power of 6000 results in fringe frequencies of roughly 20, 60, and 85 fringes across the detector. In order to avoid aliasing, the highest fringe frequency may not exceed the Nyquist frequency, that is the number of fringes across the detector width may not exceed the number of detector pixels divided by two. This example illustrates that the heterodyning aspect of DASH is essential for achieving well separated fringe frequencies that can easily be sampled by available detector arrays that typically have hundreds of pixels. Without heterodyning, the fringe frequencies would be proportional to the line positions in wavenumbers, so that in the above example, the fringe frequencies of the lines at 6060 cm −1 and 6085 cm −1 would differ by less than 0.5%. Choosing fringe frequencies that are well separated also ensures that the envelope of the beat pattern from two or more lines in the passband has a periodicity that is significantly smaller than the width of the detector. This way the interferogram sampled by the detector can never be confined to a region near a node or zero point of the beat pattern envelope, which would result in greatly reduced contrast for the entire interferogram. Rather the optimum path offset remains a function of the line shape only.
[0058] The passband is typically defined by an optical filter in the DASH instrument. It is very important to note that the DASH filter is not required to isolate a single line in the observed emission line spectrum like in the case of a stepped Michelson interferometer. This generally allows the usage of a broader filter, with significantly higher peak transmittance, less angular and thermal dependence of the transmittance, which results in higher etendue and therefore higher sensitivity of the instrument.
[0059] Noise Propagation:
[0060] In order to estimate the Doppler velocity sensitivity of a DASH instrument, one needs to estimate the precision of the phase retrieval (see Eq. (3)). Here, we specifically describe the noise propagation from the measured interferogram to the retrieved phase (see Eq. (10)).
[0061] We start with the random noise, ε 1 , of the dark and flat field corrected interferogram. For a photon shot noise limited detector array and perfect fringe contrast, one can estimate for example:
[0000]
ɛ
l
=
I
tot
N
+
ɛ
r
+
ɛ
d
(
11
)
[0062] where I tot is the total number of detected electrons in the interferogram, N is the number of interferogram samples (e.g. number of pixels in a row of the focal plane array), ε r , is the read noise component, and ε d is the dark noise component. After Fourier transformation into the spectral domain, the random noise in the interferogram propagates to random noise in the real and imaginary part of the spectrum with a distribution width of:
[0000]
ɛ
S
=
1
N
ɛ
l
(
12
)
[0063] After isolating the localized spectral feature of one emission line with a boxcar function that is n pixels wide, centered on the feature, and subsequent inverse Fourier transformation into the interferogram domain, the distribution width of the random noise in both the real and imaginary part of the isolated interferogram can be written as:
[0000]
ɛ
I
ISO
=
n
N
ɛ
l
(
13
)
[0064] It is important to point out that the line isolation with the boxcar function results in noise in the interferogram that is no longer uncorrelated from sample to sample. Only n samples remain uncorrelated, the others result from their interpolation.
[0065] Propagating the correlated noise of the isolated interferogram through Eq. (10), results in the magnitude of the correlated noise in the retrieved phase, ε p ISO , in units of radians:
[0000]
ɛ
P
ISO
=
ɛ
I
A
i
2
n
N
=
ɛ
I
I
i
2
Nn
(
14
)
[0000] where A i is the amplitude of the fringe for the isolated line i in the measured interferogram and I i is the total modulated signal detected in the interferogram for the isolated line i.
[0066] Other potential sources of error include systematic and random uncertainties from the zero wind phase subtraction or pointing errors of a satellite platform, which can result in the improper correction for the satellite velocity.
[0067] Field-Widened DASH:
[0068] The maximum field of view that can be accepted by any interferometer, and therefore its sensitivity for diffuse sources, is determined by how the interferometric path difference varies with off-axis angle. To minimize this variation and achieve a maximum possible field of view SHS instruments can be field-widened by placing fixed prisms in each arm of the interferometer. The field of view for a field widened SHS depends on the prism angle and is generally larger for smaller prism angles. The maximum solid angle that can be accepted by a field widened SHS is typically two orders of magnitude larger than interferometers without field widening. The resulting increase in sensitivity is critical for high spectral resolution geophysical measurements where signals can be weak and/or are obscured by large background signals. Field widening techniques have also been used with stepped FTS, however, in this case plane-parallel blocks of glass are used instead of prisms. FIG. 6 is a schematic diagram of a field-widened DASH interferometer (BS: Beamsplitter, G 1 /2: Gratings, P 1 /2: Field widening prisms) designed, as an example, to measure four atmospheric O 2 Δ lines in the near infrared (NIR) at wavelengths around 1.250 μm. The prism and grating angles in the two arms are the same, however, the prism in the lower right-hand portion of the figure is thicker to compensate the larger optical path in this arm. As indicated earlier, this system can be considered as a symmetric field-widened SHS with an offset aperture. Field widening is obtained by placing fixed prisms in each interferometer arm. The thicker prism (P 1 ) in the lower right arm is required to compensate the larger path difference. The grating and prism angles are the same in each arm.
[0069] Table 1 indicates key specifications and the optical performance of this interferometer as determined by ray tracing. Note in particular that the field widening prisms enable the system to view a solid angle that is approximately 450 times larger than a non-field-widened system of the same resolution.
[0000]
TABLE 1
Path difference offset Δd
6.5
cm
Path difference interval sampled
±0.39
cm
Grating angle
5.6
degrees
Resolving power at maximum path
110,000
Solid angle gain due to field widening
450×
Littrow wavelength
1.266
μm
[0070] Table 2 lists four targeted O 2 Δ lines near λ=1.250 μm along with the number of fringes each lines produces across the full aperture of the DASH interferometer. The last column indicates the number of fringes a non-heterodyned Michelson interferometer would need to record over the same path difference interval. The smaller number of fringes for the SHS and DASH enables sampling of the interferogram with a practical detector having hundreds of pixels. In order to simultaneously measure these four lines with a stepped Michelson interferometer a prefilter must be used to spatially separate each line on a different portion of the detector which adds complexity and reduces the sensitivity of the measurement.
[0000]
TABLE 2
Number of fringes for +/−0.39 cm path interval
Heterodyned
Not Heterodyned
Wavelength [μm]
(DASH, SHS)
(e.g. FTS)
1.252644
65.7
9770.6
1.254210
57.9
9782.8
1.255809
50.0
9795.3
1.257439
41.9
9808.0
[0071] Phase Stability:
[0072] Michelson-based instruments, including ones that use the DASH concept, depend on measuring the absolute phase of the fringe pattern to determine the Doppler wind velocity. As a result one of the most challenging aspects of these measurements is the calibration and tracking of instrument drifts that affect the phase measurement. The drifts can be minimized by appropriate thermal compensation within the interferometer. In addition, active thermal control is possible as well as periodic measurements of a calibration source to determine the zero wind reference. All of these techniques have been implemented previously (e.g. on the WINDII instrument) and can be readily adapted to DASH. Since DASH can measure many lines simultaneously, the calibration source can be observed during an exposure which eliminates difficulties associated with alternating exposures between science and calibration images.
[0073] Test Apparatus:
[0074] A non-field-widened breadboard DASH interferometer was built and used to measure the Doppler shift of a laboratory line source for a typical upper atmospheric wind speed. The line source and the passband of the instrument were chosen to be in the near-IR (˜1.5 μm) since there are atmospheric emission lines close to this wavelength region that are suitable for wind measurements on earth and other planets. The DASH breadboard was constructed using predominantly commercial off-the-shelf (COTS) components.
[0075] A schematic of the laboratory line source set-up that produces an alternating Doppler shifted/non-Doppler shifted signal for a laboratory DASH demonstration is shown in FIG. 7 . The complete laboratory set-up consists of two major parts, the line source and the spectrometer. A diode laser beam that is reflected from a spinning wheel provides a collimated source which can be alternated between Doppler shifted and non-Doppler shifted using a chopper wheel. The spectrometer includes the DASH interferometer, exit optics, and an array detector. The principle components of the breadboard set-up are described in Table 3.
[0000]
TABLE 3
Component
Parameter
Description
Line Source
Laser Diode
Manufacturer
Furukawa (FOL15DCWD-A81)
(Model)
Nominal
1528.78 nm
Wavelength
Output Power
40 mW
Line Width
1 MHz
Operating
Nominal: 25° C.
Temperature
Interferometer
Beamsplittter
Manufacturer
Thorlabs (BS015)
(Model)
R:T
50:50 Nonpolarizing
Flatness
1/10 @ 635 nm
Size
25.4 mm 3 (cube)
Gratings
Manufacturer
Newport Corporation
Grooves Density
300 mm −1
Blaze Angle
14.77°
Blaze Wavelength
1.71898 μm
Coating
Gold
Ruled Area
26 mm × 26 mm
Detector
InGaAs Camera
Manufacturer
Xenics (XEVA-FPA-1.7-320)
(Model)
Pixel Pitch
30 mm × 30 mm
Wavelength Range
0.9 μm-1.7 μm
D*
7.5 × 10 12 cm Hz 1/2 /W
Dynamic Range
12 bit
[0076] Referring now to FIG. 7 , the signal from a 40 mW, single-mode, temperature controlled diode laser with λ≈6630 cm −1 , passes through an optical isolator to prevent back coupling into the laser cavity. After the isolator, the beam is collimated and sent through a beamsplitter to a chopper wheel. The chopper wheel is covered with retro-reflecting tape so that a non-Doppler shifted beam is reflected back to the beamsplitter when the chopper blade blocks the optical path to the spinning disk (or Doppler wheel). The Doppler wheel is an aluminum disk, also coated with retro-reflecting tape that is mounted at an angle to the optical axis. It rotates in order to produce a Doppler shift in the retro reflected beam. The beam returning from the Doppler wheel is subsequently reflected by the beamsplitter and coupled back into an optical fiber via a focusing lens. This fiber serves as the input to the interferometer.
[0077] The optical layout of the interferometer is shown in FIG. 4 where the path difference Δd was set to 7.75 cm. The interferometer was vibrationally isolated from the optical bench and a top cover was used to suppress ambient and stray light contributions.
[0078] Results:
[0079] Single line. FIG. 8 shows a typical fringe image or interferogram as obtained by the DASH breadboard instrument when viewing a monochromatic source. As expected from Eq. (4), the image shows a cosine fringe pattern with a single spatial frequency across the detector. The image has been dark corrected and flat field corrected.
[0080] The upper panel of FIG. 9 shows the intensity within a single row of a measured interferogram, specifically, one pixel row from a single dark, flat field, and offset corrected fringe image for a monochromatic source. The middle panel of FIG. 9 shows the real and imaginary part of the Fourier transform of this interferogram, where the real part is the darker line and the imaginary part is the lighter line. The salient features of this complex spectrum are the lines around ±κ 0 =±64 fringes per detector width. This is the fringe frequency produced by the wavelength of the laser diode. Following the procedure described above, the phase of the interferogram can be determined. A change in phase is a measure of a shift in line position and thus Doppler velocity. The isolation of the feature around +κ 0 is achieved by multiplying the complex spectrum with the boxcar function also shown in the middle panel of FIG. 9 with a dotted line. The resulting phase of the interferogram is shown in the bottom panel of FIG. 9 . For a Doppler shifted line, the phase is expected to change according to Eq. (3). The phase shift of the fringe pattern along one detector row is a linear function of the optical path difference, and thus changes linearly across the recorded fringe pattern. Each pixel in the row provides a measure of a phase change due to the Doppler shift. A simple way to determine the phase shift between two fringe patterns is to compare the average phases across one single row. Subtracting these row averages yields the phase shift, δφ, in the middle of the recorded fringe pattern (x=0), for which we defined the path offset Δd (see FIG. 4 ).
[0081] The top panel of FIG. 10 shows a time series of the average phase of a single interferogram row (the row-averaged phases for each frame in a series of measurements taken at 100 measurements per second), where the average phase of the first measurement was subtracted from all subsequent ones. One can clearly see the regularly occurring phase shifts in the series that are a result of the chopped signal (a periodic phase shift of about 0.05 rad), alternating the Doppler shifted signal and the reference, non-Doppler shifted signal. One can also see a drift which is slowly varying compared to the sample rate. This drift is likely due to the control loop of the thermal stabilization of the laser. To measure the phase shift caused by the Doppler effect, the mean phase of the Doppler shifted interferogram was subtracted from the mean phase of the non-Doppler shifted interferogram. The results for several measurement series are shown in Table 4 along with the Doppler speed, v, derived from the phase shift:
[0000]
v
=
c
δϕ
4
πΔ
d
σ
(
15
)
[0000]
TABLE 4
Speed
Speed
Laser
Phase
calculated
calculated
temperature
Number of
shift
from phase
from angular
[° C.]
fringes
[rad]
shift [m/s]
wheel velocity [m/s]
67
53
0.039(09)
18.1
19.2
42
62
0.043(10)
19.9
30
66
0.044(12)
20.4
10
72
0.045(09)
20.8
[0082] The uncertainties quoted in Table 4 for the phase difference are the combined standard deviations of the two drift corrected measurement series as shown in the bottom panel of FIG. 10 . They are a combination of the random noise in the interferogram propagated through the phase determination (see Eq. 14) and systematic contributions. For this breadboard we estimate that the primary contribution to the systematic uncertainty is due to the slow drift, which we attribute mainly to the frequency stabilization of the laser. Other contributers to the uncertainties are the thermal stability of the interferometer and the exit optics. Note that the stability of the source is not an issue for an atmospheric measurement. The thermal stability of a DASH interferometer and the exit optics can be tracked simultaneously with a known emission line source as described above.
[0083] For each measurement series in Table 4 the laser was thermally tuned to a slightly different wavelength so that the recorded fringe frequency was different. Also shown in Table 4 is the expected Doppler velocity, v, calculated from the angular velocity of the rotating retro-reflecting disc, ω, the radial distance of the retro reflected spot from the disc center, r, and the angle of the disc with respect to the incident beam, θ:
[0000] v= 2 r ω cos(θ) (16)
[0084] The results agree within <1.6 ms −1 , and demonstrate the first Doppler velocity measurement using the DASH technique.
[0085] Multiple lines: An example of a flat fielded interferogram image with two lines (dark and flat field corrected fringe image) for two lines in the passband is shown in FIG. 11 . Instead of a cosine fringe with a single spatial frequency the interferogram is a beat pattern resulting from two cosine fringes with different spatial frequencies. Since our DASH breadboard only has one laser source, this image was created by adding two interferogram images, each recorded for a different, thermally tuned, laser frequency. Interferograms for a two line source could have been recorded simultaneously; however, such a source was not available to us. Since the laboratory set-up only has one monochromatic but tunable source, this image was obtained by adding two monochromatic fringe patterns for different laser frequencies and thus different fringe frequencies.
[0086] FIG. 12 shows one row of the two line interferogram image in the upper panel and the complex spectrum in the bottom panel. Just as for the single line case, each one of the lines can be isolated (e.g. with a box car function centered on the spectral feature). In case the instrumental line shape function contributions from the neighboring lines are considered to be a non-negligible contribution, one can consider apodizing the interferogram which helps to localize the spectral feature (i.e. suppress the line shape contributions in the wings of the line). The remaining data processing to determine the phase is identical to the single line case. This procedure can also be readily applied in the case of three or more lines in the passband as long as the spectral features are well separated so they can be isolated. A phase determination can be achieved for each line independently.
[0087] The invention accordingly includes a phase-stepped Michelson technique and Spatial Heterodyne Spectroscopy (SHS). Like the phase-stepped Michelson, the interferogram is sampled only at large optical path differences but the interferometer arms are terminated with fixed, tilted gratings, like in SHS. This design enables the measurement of not just four but hundreds of phase points of a heterodyned interferogram over a large path difference interval simultaneously without moving parts.
[0088] For the measurement of Doppler winds the instrument preferably employs a large enough offset in path difference to enable the wind measurement and a large enough path difference interval to separate the multiple spectral components, i.e. emission lines in the passband. DASH like SHS allows field widening without moving parts by choosing prisms of the appropriate wedge angle and thickness for each arm.
[0089] Just as for stepped FTS and Fabry Perot interferometers, thermal effects on the measured phase are expected to be significant. To mitigate these effects, the DASH interferometer can be designed using materials that provide maximum thermal compensation as has been successfully demonstrated for stepped FTS, such as is described in Thuillier G. and G. G. Shepherd, “Fully compensated Michelson interferometer of fixed path difference,” Appl. Opt., 24, 1599, 1985, and Thuillier G. and M. Herse, “Thermally stable field compensated Michelson interferometer for measurements of temperature and wind in the planetary atmospheres,” Appl. Opt., 30, 1210, 1991, both of which are incorporated herein by reference. In addition, the above mentioned simultaneous phase tracking may be used to quantify and ultimately correct the remaining thermal effects.
[0090] Referring now to FIG. 13 , a parallel arm DASH spectrometer 200 is another embodiment employing the DASH concept, where the functionality provided by the beamsplitter 106 of the DASH spectrometer 100 along with making the chief rays entering the two interferometer arms parallel is provided by a Kösters prism 201 , e.g. as described in U.S. Pat. No. 4,061,425, J. F. Wade, issued Dec. 6, 1977. Kösters prism 201 is a compound prism consisting of two identical 30-60-90 first and second prisms 202 and 204 joined at their longer legs/faces 203 and 205 to form a beamsplitting interface surface 206 (resulting from treating at least one of faces 203 and 205 with a suitable beamsplitter coating). The shorter legs 208 and 210 form a planar base 212 with the interface surface 206 terminating at its midline. A first prism hypotenuse surface is the light entrance face 216 while a second prism hypotenuse surface is the light exit face 214 . Light accordingly enters the Kösters prism from the left through entrance face 216 and is divided into two beams by the beamsplitting surface 206 . Subsequently, the two beams are made parallel by a total reflection on the prism faces 214 and 216 . The beams then pass through an optional single field-widening prism 218 and are diffracted by a single grating 220 . The diffracted beams are again reflected by the prism faces 214 and 216 and partially reflected and transmitted by the surface 206 , so that the signal exiting the Kösters prism on the lower right is the superposition of half of the signal originating from each interferometer arm. The other half of the signal is exiting the Kösters prism on the entrance side 214 , just as in a single port FTS, a conventional SHS, or DASH interferometer.
[0091] Like the DASH spectrometer 100 , the parallel arm DASH spectrometer 200 can be temperature compensated. In particular, the effect of the grating groove expansion is compensated by the thermal change in the index of refraction of the field widening prism. If the interferometer expands around the bottom left point of the Kösters prism as shown in FIG. 13 , i.e. if it is held there, the effect of the change in length of the interferometer arms due to a temperature change is zero.
[0092] Spectrometer 200 requires only one field widening prism and one grating instead of two each for spectrometer 100 , providing labor/cost savings. The Kösters prism 201 is available off the shelf, which significantly reduces the cost of this component compared to a custom fabrication of the corresponding components of spectrometer 100 . If spacers are used to assemble the interferometer, only two instead of four spacers are used (again, labor/cost savings). The equality of the fieldwidening prism angle, fieldwidening prism rotation, fieldwidening prism tilt, grating angle, grating rotation, grating tilt, and grating tilt in each arm is achieved by using the same prism and grating for both arms. This simplifies the alignment (again, labor/cost savings) when compared to where the elements in the two arms are independent. Tere is improved thermal stability of the interferometer, due to the proximity of the two arms and their close contact, which reduces thermal gradients, and since the effect of the thermal expansion on the length of the interferometer arms is eliminated when the interferometer is held on the line where two Kösters prism faces intersect with the beamsplitting surface. Thus, spectrometer 200 has a reduced cost with improved performance compared to spectrometer 100 .
[0093] While the present invention has been described in terms of a preferred embodiment, it is apparent that skilled artisans could make many alterations and modifications to such embodiments without departing from the teachings of the present invention. Accordingly, it is intended that all such alterations and modifications be included within the scope and spirit of the invention as defined in the following claims.
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A Doppler Asymmetric Spatial Heterodyne (DASH) spectrometer includes an input aperture for receiving an input light; a collimating lens for collimating the input light into a collimated light; offset establishing means, including at least one grating, for i) receiving and splitting the collimated light into a first light wavefront in a first optical path and into a second light wavefront in a second optical path, ii) establishing an offset in a light wavefront path distance between the first and second optical path light wavefronts, and iii) diffracting and recombining the first and second optical path light wavefronts into an interference wavefront to form an interference image that includes a plurality of phase points of a heterodyned interferogram measured simultaneously over the path distance offset; and an output optics section comprising a detector for receiving the interference image and outputting an interference image pattern.
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BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a device for converting or changing the modes of operation of a paper-conducting cylinder of a folder, more specifically, for causing, for example, a collecting cylinder of a folder to convert between collecting and non-collecting productions, a draw cylinder of a folder to convert between drawing and non-drawing, a tucker-blade cylinder of a folder to concert between forming a crease and not forming a crease, a folding cylinder of a folder to convert between folding and non-folding, and the like. In the case of the collecting cylinder, that cylinder is equipped at its perimeter with at least one folding or tucker blade and with at least one set of holding elements, a control disc for the folding or tucker blade having a peripheral contour forming a control cam for actuating elements generating a movement of the folding blade, a control disc for the holding elements having a peripheral contour forming a control cam for actuating elements generating a movement of fastening elements, and a device for moving one of the control discs, independently of the drive, for switching between the collecting production and non-collecting production.
The published European Patent Document EP-A-0 355 595 A2 discloses a folder including a collecting cylinder equipped with holding elements in the form of grippers, and folding blades. Elements for actuating the holding elements and the folding blades may be activated by respective control cams which are provided with hollow control zones. On relief or projection holders mounted coaxially with the control cams, covering reliefs or projections are formed which are movable radially and which thus cover or overlap the control zones of the control cams into which a feeler or sensing roller of the actuating elements forming part of the holding elements or of the folding blades would otherwise fall. A second feeler roller mounted beside the first feeler roller rolls over the cover relief or projection, covering or overlapping the control zone of the control cam. Thus, the first feeler roller is prevented from falling into the control zone.
In commercial web offset printing, in which a small to medium number of pages are printed, the mechanical complexity which goes hand-in-hand with this solution, is no longer tolerable.
The published European Patent Document EP 0 335 190 B1 describes a folding and collecting cylinder of a folder. In this construction, stationary tucker-blade and pin cam discs and driven tucker-blade cam and pin cam covering discs can be found adjacent one another. The two covering or overlapping discs are driven by a separate drive mechanism independently of the main drive. The drive mechanism acts upon a gearwheel which, in turn, acts upon a hollow pinion, worm toothing being provided on a hollow cylindrical appendage thereof. An axial movement of the hollow pinion produces a conversion or change in mode of the folder between collecting production and non-collecting production.
In this last-described construction in the state of the art, as with that of the previously mentioned published European Patent Document EP-A-0 355 595 A2, recourse is had to covering discs which can furthermore be driven separately. Two feeler or sensing rollers, one of which runs over the covering disc, while the other runs over the corresponding cam disc, are thus required per set of holding elements or per set of folding or tucker blades.
Starting from the aforementioned state of the art, it is an object of the invention to provide a device for converting or changing the mode of a collecting cylinder of a folder, wherein the transition of a collecting cylinder from collecting production to non-collecting production is automated, while the mechanical complexity is reduced.
With the foregoing and other objects in view, there is provided, more particularly, in accordance with the invention, a device for converting or changing a mode of operation of a paper-conducting cylinder of a folder having at the circumference thereof at least one element for operating on the paper conducted by the cylinder, a control disc having a peripheral contour forming a control cam for at least one actuating element for generating a movement of the operating element, and a device for moving the control disc, independently of a drive therefor, so as to switch the mode of the paper-conducting cylinder between operating on the paper and not operating on the paper, comprising at least one first adjustment element activatable axially and angularly by remote control for radially moving the actuating element, and at least one second adjustment element activatable by remote control for axially moving the control disc.
In accordance with another feature of the invention, the paper-conducting cylinder is a draw cylinder.
In accordance with a first alternative feature of the invention, the paper-conducting cylinder is a tucker-blade cylinder.
In accordance with a second alternative feature of the invention, the paper-conducting cylinder is a folding cylinder.
In accordance with a third alternative feature of the invention, the paper-conducting cylinder is a collecting cylinder.
In accordance with another aspect of the invention, there is provided a device for causing a collecting cylinder of a folder to convert or change mode between collecting and non-collecting productions, the cylinder being equipped at its periphery with at least one folding blade and with at least one set of holding elements, a permanently driven control disc for the folding blade having a peripheral contour forming a control cam for actuating elements generating a movement of the folding blade, a permanently driven control disc for the holding elements having a peripheral contour forming a control cam for actuating elements generating a movement of the holding elements, and a device for moving one of the control discs, independently of the drive, for switching between the collecting production and the non-collecting production, comprising first adjustment elements activatable axially and angularly by remote control for radially moving the actuating elements of the folding blade and of the holding elements, and second adjustment elements activatable by remote control for axially moving the permanently driven control discs.
In accordance with another feature of the invention, the converting device includes transmission members connecting the adjustment elements to an adjustment member.
In accordance with an added feature of the invention, one of the adjustment elements has an annular form and is mounted on a bushing.
In accordance with a further feature of the invention, the annular adjustment element includes first and second relief or projecting members formed as fingers, which are insertable into recesses formed in a segment of the folding blade as well as in a perforation segment of the collecting cylinder.
In accordance with an additional feature of the invention, the converting device includes position sensors for detecting the position of the annular adjustment element.
In accordance with yet another feature of the invention, the converting device includes a lateral wall wherein the bushing is fitted so that it can turn angularly through the intermediary of other adjustment elements.
In accordance with yet a further feature of the invention, the converting device includes folding-blade levers fitted on a blade shaft and actuatable by the first finger-shaped relief members.
In accordance with yet an added feature of the invention, the converting device includes holding-element levers carried by a holding-element shaft and actuatable by the second finger-shaped relief members.
In accordance with yet an additional feature of the invention, the annular adjustment element is provided together with a device for blocking rotation thereof on the bushing.
In accordance with still another feature of the invention, the converting device includes a bushing, the transmission members and the adjustment member being mounted on the bushing for performing an axial movement.
In accordance with still a further feature of the invention, the converting device includes other adjustment members for angularly turning the bushing, the transmission members being connected to and actuatable by the first-mentioned adjustment member independently of at least one of the other adjustment members for angularly turning the bushing.
In accordance with still an added feature of the invention, the control discs, respectively, include two separate bearing surfaces for the actuating elements for moving the folding knives and the holding elements.
In accordance with still an additional feature of the invention, the actuating elements for the folding knives and for the holding elements are mounted on the collecting cylinder and constitute a single feeler roller.
In accordance with another feature of the invention, the converting device includes a control disc holder carrying the control discs on a separately driven sleeve, the control disc holder being movable axially between positions.
In accordance with a further feature of the invention, the actuating elements, during the axial movement of the control disc holder, stop in a position remote from the control discs.
In accordance with another aspect of the invention, there is provided a converting device in combination with convertible collecting cylinders of a folder, the collecting cylinders have a diameter corresponding to an odd number of copies to be transported on the periphery thereof.
In accordance with an added feature of the invention, the converting device includes a sliding guide for initiating the axial movement of the control discs.
In accordance with a concomitant feature of the invention, the converting device includes an angularly movable annular adjustment element having a fingerlike extension, and an adjustment member for angularly moving the annular adjustment element so as to cause the movement of the control discs between a first axial position and a second position, and in reverse.
An advantage of the foregoing construction according to the invention is that it makes it possible to dispense with covering discs, radial movement or adjustment of the covering reliefs or projections, as well as a separate drive of the covering discs may be dispensed with if the elements for actuating the holding elements as well as the folding blades can be moved or adjusted radially. Furthermore, while the actuating elements have no contact with the bearing surfaces formed on the control cams, an axial movement of the control cam is possible in order to convert from collecting production to non-collecting production or the reverse.
Because the stopping of the actuating elements by the control discs and the associated axial movement of the control discs can be performed by remote control, time-consuming in-phase positioning, as well as using tools for a conversion or mode-change operation is unnecessary; the conversion or mode change process occurs considerably faster and drastically reduces the required make-ready time.
The first adjustment elements for radially moving the elements for actuating the folding knives and the holding elements are connected to an adjustment member by transmission members; in particular, an annular adjustment element is provided, mounted on a bushing. The annular adjustment element has at least one pair of first and second reliefs or projections in the form of fingers, one of which is insertable into openings formed in the segment of the folding blade and the other into recesses formed in a segment of the holding element of the collecting cylinder. The position of the annular adjustment element can be detected by position sensors; furthermore, the bushing can be mounted on the annular adjustment element and can be turned angularly by the adjustment elements.
Folding blade levers mounted on a blade shaft are actuatable by the first finger-shaped reliefs or projections, while the second finger-shaped reliefs or projections can actuate holding element levers mounted on a holding element shaft. In order to transmit the angular movement from the bushing to the finger-shaped reliefs or projections, the annular adjustment element is provided on the bushing with a device for blocking its rotation.
The transmission members and the adjustment member for executing an axial movement are mounted on the bushing, thereby assuring that an independent axial movement of the adjustment member used for the angular movement of the bushing will be achieved.
The control discs for activating the holding elements and folding blades include, respectively, two bearing or contact surfaces separated from one another, while the folding blades and the holding elements mounted on the collecting cylinder, respectively, carry, as actuating elements, an individual feeler roller. An axial movement of the control discs mounted in a control disc holder may, for example, be initiated by a sliding guide or coulisse. The angular or radial movement of an annular adjustment element, including a finger-shaped relief or projection, results in the movement of the control discs between a first position and a second position, and the reverse.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a device for changing mode of a collecting cylinder of a folder, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is an end view of a collecting cylinder with three pairs of actuating elements for holding elements and folding knives;
FIG. 1b is a view of a pin holder and of a tucker-blade bearing on the collecting cylinder;
FIG. 2 is a plan view of devices for axially and angularly moving switching or converting components,
FIG. 3 is a cross-sectional view of FIG. 2 taken along the line III--III in the direction of the arrows;
FIG. 4 is a cross-sectional view of FIG. 2 taken along the line IV--IV in the direction of the arrows;
FIG. 5 is a cross-sectional view of FIG. 3 taken along the line V--V in the direction of the arrows;
FIG. 6 is a sectional view of a bearing support for the collecting cylinder on the drive side;
FIG. 7 is a fragmentary sectional view of FIG. 6 taken along the line VII--VII in the direction of the arrows; and
FIG. 8 is a side elevational view of the control device for the axial movement of the control discs.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and, first, particularly to
FIG. 1a thereof, there is diagrammatically represented therein a collecting cylinder 1 which can be converted from collecting operation to non-collecting operation. On the periphery or circumference 4 of the collecting cylinder 1, there are provided three sets of holding elements 2 (two of which are represented) and three folding or tucker blades 3 (two of which are represented). Actuating elements 7 and 8 in the form of feeler, sensing or follower rollers run on control cams 5 and 6. The feeler roller 8 for actuating the folding blade 3 runs on the perimeter of the control cam 5, while the feeler roller 7 for actuating the holding elements 2 runs on the control cam 6. The control cams 5 and 6, respectively, are provided on the peripheral contours thereof with reliefs or projections which, the instant the feeler rollers 7 and 8 pass over them, activate the folding blades 3 or the holding elements 2.
FIG. 1a represents a collecting cylinder 1 which transports three copies on the perimeter 4 thereof. However, it could quite equally well relate to a collecting cylinder 1 which has a diameter permitting five or seven copies, i.e., an odd number of copies, to be transported. FIG. 1b presents a side view of the holding elements and of the tucker or folding blades for transverse or crossfolding.
A holding element shaft 9 carries levers 10, at the end of which a holding element 2, shown herein in broken lines as a punch needle, is mounted. Furthermore, an actuating lever 11 is fixed to the holding element shaft 9. Facing the free end of the actuating lever 11 is a first relief or projection 12 in the form of a finger which, when rotating in clockwise direction, causes the holding element shaft 9 to turn in the counter-clockwise direction.
A folding or tucker blade 3 for forming a transverse or crossfold is fixed on a blade shaft 13. A blade lever 14 mounted on the blade shaft 13 extends radially relative to the axis of rotation of the collecting cylinder 1. Facing the free end of the blade lever 14 is a second relief or projection 15 in the form of a finger. When the latter moves in clockwise direction, the blade shaft 13 turns in the opposite direction.
In the embodiment represented in FIG. 1b, a first relief or projection 12 and a second relief or projection 15 in the form of fingers form a pair. Three pairs of reliefs or projections (only two of which are represented) are provided, which makes it possible to activate three sets of holding elements 2 or folding blades 3.
FIG. 2 is a plan view of the components which permit the axial and angular or radial movements during the switching or conversion of a collecting cylinder.
For the angular movement of a bushing 19 which is mounted in a lateral wall of a folder, recourse is had to an adjustment member 16. This may be an operating cylinder, a motor or an electromagnet. A fork 17 which is connected to a flange 18 is mounted on the adjustment member 16. The flange 18 is fixed to the bushing 19. On the flange 18 is a finger which actuates two terminal switches 20, in order to determine the angular position of the bushing 19. Adjacent the flange 18, there are two travel limiting devices 21 by means of which the travel of the flange 18 and, therefore, the extent of rotation of the bushing 19 may be influenced. With the adjustment member 16, it is therefore possible to cause the bushing 19 to turn angularly in both directions.
On the bushing 19, there is another adjustment member 22, shown herein as an operating cylinder. To the adjustment member 22, there is fixed a fork 23 permitting a shaft 24, which is mounted on a cover, to turn. Two transmission members 26 in the form of adjustment rods are fixed on the shaft 24 which is turnable by means of a lever 25. Because the shaft 24 is eccentric relative to the axis of symmetry of the journal 31 of the cylinder, a rotation of the shaft 24, produced by the adjustment member 22, gives rise to an axial movement of the transmission members 26 perpendicularly to the plane of the drawing.
FIG. 3 is a sectional view taken along the line III--III of FIG. 2.
The adjustment members 16 and 22 and the components interacting with them are disposed in the region of the bushing 19. By means of a roller bearing, the journal 31 of the cylinder is mounted in the bushing 19. On the latter, there is an annular adjustment element 27 which can be moved axially on the bushing 19. To the annular adjustment element 27, there is fixed a spindle which includes a disc. By means of the spindle, the axial position of the annular adjustment element 27 is able to be observed, via position sensors 28.1 and 28.2 fixed to the lateral wall of the folder. The first and second reliefs or projections 12 and 15, respectively, in the shape of a finger, are fixed to the annular adjustment element 27. During an axial movement of the annular adjustment element 27, effected by the transmission members 25 and 26 as well as by the adjustment member 22, the first relief or projection 12 in the shape of a finger passes behind the actuating lever 11 of the holding element support 1.2 of the collecting cylinder 1. At the same time, the second relief or projection 15 in the form of a finger, also fixed to the annular adjustment element 27, moves behind the blade lever 14 on the blade support 1.1. If the adjustment member 16 causes an angular movement of the bushing 19, the annular adjustment element 27 is also moved angularly, due to the rotation-blocking device 29. The reliefs or projections 12 and 15 inserted into the respective supports 1.1 and 1.2 of the collecting cylinder are also moved angularly or radially and, via the levers 11 and 14, effect a rotation of the shafts 9 and 13. Because the actuating elements 7 and 8 are connected to the shafts 9 and 13, the actuating elements 7 and 8 (note FIGS. 1a and 1b) are moved away from the respective bearing surfaces of the control cams 5 and 6.
It ought also to be mentioned that a lubricant supply 30 passes through the journal 31 of the cylinder and another, non-movable bushing. Furthermore, on the outer side of the bushing 19, there is provided a travel-limiting or terminal switch 32 which detects the excursion of the lever 25.
FIG. 4 is a sectional view taken along the line IV--IV of FIG. 2.
This figure shows that the shaft 24 is supported in bearings which are fixed to a cover screwed to the bushing 19. By means of the lever 25, the shaft 24 is turnable, so that the adjustment rods 26 can be moved axially. In the upper half of FIG. 4, the second relief or projection 15 in the form of a finger, is represented in a position located behind the blade lever 14. The set-back position of the annular adjustment element 27 is represented in phantom. In the lower half of FIG. 4, the first relief or projection 12 in the form of a finger is represented in a position in which it is withdrawn from the holding-element support 1.2. As a consequence, the annular adjustment element 27, connected to the adjustment rod 25, is in its set-back position. Represented in phantom is a position in which the first relief 12 in the form of a finger is pulled out behind the actuating lever 11 of the holding-element support 1.2.
FIG. 5 is a view of the annular adjustment element and a fragmentary sectional view taken along the line V--V of FIG. 3.
On the periphery of the annular adjustment element 27, first and second reliefs or projections 12 and 15, formed as fingers, are provided in pairs. As in the aforedescribed FIGS. 3 and 4, the second reliefs or projections 15, in the form of fingers which penetrate into the blade support 1.1, are longer than the first reliefs or projections 12, also formed as fingers, which penetrate into the holding-element support 1.2 directed towards the annular adjustment element 27. Mounted on the bushing 19 is the axially extending device 29 for blocking or preventing rotation, one of the position sensors being shown at 28.1.
FIG. 6 is a drive-side view of the bearing support for the collecting cylinder.
A first bushing or sleeve 36 which drives the blade support 1.1 of the collecting cylinder 1 is, in turn, driven by a drive wheel 35. A cylinder journal 34, which is connected to the holding-element support or segment 1.2 of the collecting cylinder 1 and which turns at the same peripheral speed as that of the blade support 1.1, is driven by a non-illustrated drive wheel. A second bushing or sleeve 37 is supported by roller bearings 39 and 40 mounted on the first bushing 36. This sleeve 37 is driven by a drive wheel 47 at a different speed from the drive speed of the supports or segments 1.1 and 1.2 of the collecting cylinder 1. A control cam holder 38 is provided on the second bushing or sleeve 37. The control cams 5 and 6 are fastened to the control cam holder 38.
An adjustment device 46, which is shown more particularly in FIGS. 7 and 8, is mounted by means of a roller bearing 41 on the control cam holder 38. The roller bearing 41 is fixed to the control cam holder 38 at both sides in axial direction.
The control cams 5 and 6, respectively, have two bearing tracks. The control cam 5 for actuating the blade has a bearing track 5.1 for the "non-collecting" mode and a bearing track 5.2 for the "collecting" mode. The same is true for the control cam 6 of the holding elements 2. Bearing tracks 6.1 and 6.2 of the control cam 6 are used to actuate the holding elements 2 via the individual feeler roller 7, while the feeler rollers 8 for actuating the blades 3 run on the bearing tracks 5.1 and 5.2 of the control cam 5. The bearing track 6.1 produces a movement of the holding elements 2 in the "non-collecting" mode, whereas the bearing track 6.2 defines the instants of time at which the holding elements 2 are actuated in the "collecting" mode.
If, as mentioned hereinbefore with reference to FIG. 3, the various feeler rollers 7 and 8 are radially separated from the bearing tracks 5.2 and 6.2, i.e., in the "collecting" mode, the control cam holder 38 can be moved into the second position 38.2 thereof represented in FIG. 6 in phantom.
Then, by rotating the annular adjustment element 27, the actuating levers 11 and 14, respectively, are returned, and the shafts 9 and 13 therefore rotate back again, so that the individual feeler rollers 7 and 8 of the various holding elements 2 and folding blades 3 can reposition themselves on the bearing tracks 5.1 and 6.1 in accordance with the "non-collecting" mode. The bearing tracks 5.1 and 6.1 of the control cams 5 and 6 employed herein for a collecting cylinder 1 for three copies have two lobes, whereas the bearing tracks 5.2 and 6.2 of the cams 5 and 6 have just one lobe which corresponds to the "collecting" mode.
In a collecting cylinder which accepts five copies on the peripheral surface thereof, the bearing tracks 5.1 and 6.1 have four lobes, the bearing tracks 5.2 and 6.2 having just two lobes. In a collecting cylinder which accepts up to seven copies on the periphery thereof, the bearing tracks 5.1 and 6.1 have six lobes, whereas the bearing tracks 5.2 and 6.2 have three lobes.
FIG. 7 represents one possible construction for effecting a radial or angular adjustment on the drive side.
The adjustment member 43, for example, a cylindrical adjustment unit supplied with compressed air, moves a lever 44 which is connected to an annular adjustment element 48. The axial movement of the adjustment cylinder 43 is converted into a rotational movement of the annular adjustment element 48. A relief or projection in the form of a finger 49 is mounted in this annular adjustment element 48, and is movable in a slot 50 formed in a guide element 51. This guide element 51 is mounted via bolts 52 on a fastening element 42.
As can be seen in FIG. 8, the slot 50 is in an inclined position in the guide element 51. An effect of the inclination of the slot 50 in the guide element 51 is that, due to the rotation of the annular adjustment element 48, the relief or projection in the form of a finger 49, which is fixed to the ring 48, transmits an axial movement to the control cam holder 38. Accordingly, the control discs 5 and 6 which have respective bearing surfaces 5.1, 5.2; 6.1, 6.2, can be moved into different positions.
Because the contours of the bearing surfaces 5.1, 5.2.; 6.1, 6.2 are different depending upon whether the operation is taking place in collecting or non-collecting mode, the control rollers 7 and 8 running on the respective bearing surfaces are repositioned after the axial movement of the control discs 5 and 6.
Because the conversion or mode-change operations are initiated by means of operating or adjustment cylinder units, the conversion process progresses automatically by remote control, which considerably reduces the make-ready or preparation time. Furthermore, time-consuming in-phase positioning of the individual adjustment members can be dispensed with, because the risk of collision during a conversion or change in mode is eliminated due to the angular or radial movement or adjustment of the actuating members.
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Device for converting or changing a mode of operation of a paper-conducting cylinder of a folder having at the circumference thereof at least one element for operating on the paper conducted by the cylinder, a disc having a peripheral contour forming a control cam for at least one actuating element for generating a movement of the operating element, and a device for moving the control disc, independently of a drive therefor, so as to switch the mode of the paper-conducting cylinder between operating on the paper and not operating on the paper, includes at least one first adjustment element activatable axially and angularly by remote control for radially moving the actuating element, and at least one second adjustment element activatable by remote control for axially moving the control disc.
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